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Sample records for growth ring width

  1. Simulation of tree ring-widths with a model for primary production, carbon allocation and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C.; Falster, D.

    2014-07-01

    We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the P model). The P model provides values for Gross Primary Production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport-tissue, and fine root production and respiration, in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountain, northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilization over the past 50 years is too small to be distinguished in the ring-width data given ontogenetic trends and interannual variability in climate.

  2. Simulation of tree-ring widths with a model for primary production, carbon allocation, and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C.; Falster, D.

    2014-12-01

    We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the "P" model). The P model provides values for gross primary production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport tissue, and fine-root production and respiration in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (the impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during the period 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountains in northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, and old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilisation over the past 50 years is too small to be distinguished in the ring-width data, given ontogenetic trends and interannual variability in climate.

  3. Tree growth inference and prediction from diameter censuses and ring widths.

    PubMed

    Clark, James S; Wolosin, Michael; Dietze, Michael; Ibáñez, Inés; LaDeau, Shannon; Welsh, Miranda; Kloeppel, Brian

    2007-10-01

    Estimation of tree growth is based on sparse observations of tree diameter, ring widths, or increments read from a dendrometer. From annual measurements on a few trees (e.g., increment cores) or sporadic measurements from many trees (e.g., diameter censuses on mapped plots), relationships with resources, tree size, and climate are extrapolated to whole stands. There has been no way to formally integrate different types of data and problems of estimation that result from (1) multiple sources of observation error, which frequently result in impossible estimates of negative growth, (2) the fact that data are typically sparse (a few trees or a few years), whereas inference is needed broadly (many trees over many years), (3) the fact that some unknown fraction of the variance is shared across the population, and (4) the fact that growth rates of trees within competing stands are not independent. We develop a hierarchical Bayes state space model for tree growth that addresses all of these challenges, allowing for formal inference that is consistent with the available data and the assumption that growth is nonnegative. Prediction follows directly, incorporating the full uncertainty from inference with scenarios for "filling the gaps" for past growth rates and for future conditions affecting growth. An example involving multiple species and multiple stands with tree-ring data and up to 14 years of tree census data illustrates how different levels of information at the tree and stand level contribute to inference and prediction. PMID:17974333

  4. Growth rate and ring width variability of teak, Tectona grandis (Verbenaceae) in an unmanaged forest in East Timor.

    PubMed

    Sousa, Vicelina B; Cardoso, Sofia; Quilhó, Teresa; Pereira, Helena

    2012-03-01

    Teak (Tectona grandis) is one of the most valuable timbers in international trade and an important species for tropical forestry. Teak is found on the island of East Timor but no information is available on teak growth from this region. A pure stand planted in 1940-50 in the North of East Timor and left unmanaged was studied. Fifteen trees were sampled in October-November 2003 and stem discs taken at three height levels of its height (1.7m, 9.5m and 18.7m), and cores were collected at DBH. Transverse surfaces of the discs and cores were polished for ring identification. Core cross sections were first digitized and disc cross sections were observed under the microscope. Three randomly selected radii were analyzed in each disc. Ring width measurement and ring counting were done using image analysis software. The distinction between heartwood and sapwood was performed macroscopically by colour difference, and heartwood radius and sapwood width were measured. The relationship between stem and heartwood radius was studied for each disc and heartwood percentage by radius was determined. Radial ring width curves are presented for the different axial positions within the stem, and ring width variability was analyzed. Growth rates were calculated and age-radius relationships were estimated using cumulative growth curves. Growth rings were large and well defined in the juvenile phase, reflecting the specie's fast-growing character. The year-to-year variation of ring width showed a similar pattern among trees. Mean ring width ranged between 4.3-7.3mm for the first 20 years and 3.3-5.1mm for 30 to 45 years. Pith eccentricity was evident in the lower part of the stem and ring wedging occurred. On average, heartwood represented 84% of the radius and sapwood contained 6 to 11 rings. The age-related variation of ring width and the occurrence in the lower part of the tree stems of eccentricity and wedging rings, highlights the importance of appropriate stand management

  5. Soil Warming and Fertilization Effects on Growth Ring Widths of Arctic Shrubs - Application of a Novel Dendroecological Approach.

    NASA Astrophysics Data System (ADS)

    Iturrate Garcia, M.; Heijmans, M.; Schweingruber, F. H.; Niklaus, P. A.; Schaepman-Strub, G.

    2015-12-01

    Climate warming is suggested as the main driver of shrub expansion in arctic tundra regions. Shrub expansion may have consequences on biodiversity and climate, especially through its feedbacks with the energy budget. A better understanding of shrub expansion mechanisms, including growth rate patterns and stem anatomy changes, and their sensitivity to climate is needed in order to quantify related feedbacks. We present a novel dendroecological approach to determine the response of three arctic shrub species to increased soil temperature and nutrients. A full factorial block-design experiment was run for four years with a total of thirty plots. Six individuals of each species were sampled from each plot to test for treatment effects on growth rate and stem anatomy. We compared the ring width of the four years of experiment with the one of the four previous years. The preliminary results for Betula nana and Salix pulchra suggest a significant effect of the treatments on the growth ring width. The response is stronger in Salix pulchra than in Betula nana individuals. And, while Salix pulchra is more sensitive to the combined soil warming and fertilization treatment, Betula nana is to the fertilization treatment. We could not observe an effect of treatment on the stem anatomy, likely because bark thickness co-varies with age. We found significant positive correlations of cork, cortex and phloem thickness with xylem thickness (used as a proxy of age), and a significant difference in stem anatomy between species. The results suggest species-specific growth sensitivity to soil warming and nutrient enhancement. The use of experimental dendroecology by manipulating environmental conditions according to future climate scenarios and testing effects on shrub anatomy and annual growth will increase our understanding on shrub expansion mechanisms. Ongoing plant trait analysis and consecutive application in a 3D radiative transfer model will allow to quantify the feedback of

  6. Traffic pollution affects P. pinea growth according to tree ring width and C and N isotopic composition

    NASA Astrophysics Data System (ADS)

    Battipaglia, Giovanna; Marzaioli, Fabio; Lubritto, Carmine; Altieri, Simona; Strumia, Sandro; Cherubini, Paolo; Cotrufo, M. Francesca

    2010-05-01

    Urbanization and industrialization are rapidly growing, as a consequence roads and their associated vehicular traffic exerts major and increasing impacts on adjacent ecosystems. Various studies have shown the impact of vehicle exhausts on road side vegetation through their visible and non-visible effects (Farmer and Lyon 1977, Sarkar et al., 1986, Angold 1997, Nuhoglu 2005) but, presently there is little known about the long term effect of air pollution on vegetation and on trees, in particular. Developing proxies for atmospheric pollution that would be used to identify the physiological responses of trees under roadside car exhaust pollution stress is needed. In this context we propose a novel method to determine the effect of car exhaust pollution on tree growth, coupling classical dendrochronological analyses and analyses of 15N and 13C in tree rings, soils and leaves with tree ring radiocarbon (14C) data. Pinus pinea individuals, adjacent to main roads in the urban area of Caserta (South Italy) and exposed to large amounts of traffic exhausts since 1980, were sampled and the time-related trend in the growth residuals was estimated. We found a consistent decrease in the ring width starting from 1980, with a slight increase in δ13C value, which was considered to be a consequence of environmental stress. No clear pattern was identified in δ15N, while an increasing effect of the fossil fuel dilution on the atmospheric bomb-enriched 14C background was detected in tree rings, as a consequence of the increase in traffic exhausts. Our findings suggest that radiocarbon is a very sensitive tool to investigate small-scale (i.e. traffic exhaust at the level crossing) and large-scale (urban area pollution) induced disturbances. References Angold PG. Impact of a road upon adjacent heathland vegetations: effect on plant species compositions. J Appl Ecol 1997; 34 (2): 409-417. Farmer JC, Lyon TDB. Lead in Glasgow street dirt and soil. Sci Tot Environ 1977; 8: 89-93. Nuhoglu

  7. Dependence of tree ring stable isotope abundances and ring width on climate in Finnish oak.

    PubMed

    Hilasvuori, Emmi; Berninger, Frank

    2010-05-01

    We measured ring widths and isotopic abundances of carbon, oxygen and hydrogen (delta(13)C, delta(18)O and delta(2)H) from the latewood of tree rings of pedunculate oak (Quercus robur L.) in its distributional northern limit in Southern Finland. Ring width was observed to be related to precipitation and relative humidity but not significantly to temperature. delta(13)C and delta(18)O were significantly related to all studied climatic variables, most strongly to cloud cover. Variations in delta(2)H were discovered to be complex combinations of signals from biochemical and physical processes. The results suggest that oaks in Finland can be used as a source of climate information. delta(18)O was discovered to be especially promising as it showed the strongest climate signal and highest common signal between trees. The relationship between climate and ring width indicates that water availability is the main control of ring radial growth. This is supported by the isotope data. High correlation between delta(13)C and delta(18)O time series indicates that photosynthetic carbon assimilation is limited by stomatal control. Therefore, in contrast to the expected temperature limitation, our data indicate that drought limits oak growth more than cold temperatures on the border of its northernmost distribution range. PMID:20357343

  8. On the Assimilation of Tree-Ring-Width Chronologies

    NASA Astrophysics Data System (ADS)

    Acevedo, Walter; Reich, Sebastian; Cubasch, Ulrich

    2015-04-01

    Data assimilation (DA) of climate proxy records is currently acknowledged as a promising approach to the paleoclimate reconstruction problem, with the potential to bring physical consistency to reconstructed fields. Previous paleo-DA studies have typically assumed a linear relationship between climate forcing and the resulting proxy data, whereas there exist growing evidence of complex, potentially non-linear, proxy formation processes. Accordingly, it appears natural to simulate the proxy response to climate in a more realistic fashion, by way of proxy-specific forward models. Following this train of thought, we investigate the assimilation of the most traditional climate proxy type, Tree-Ring-Width (TRW) chronologies, using the process-based tree-ring growth forward model Vaganov-Shashkin-Lite (VSL) and ensemble Kalman filter (EnKF) techniques. Used as observation operator, VSL's formulation implies three compounding, challenging features: (i) time averaging, (ii) "switching recording" of 2 variables and (iii) bounded response windows leading to "thresholded response". DA experiments involving VSL-based pseudo-TRW observations are performed first for a chaotic 2-scale dynamical system, used as a cartoon of the atmosphere-land system, and then for an atmospheric general circulation model of intermediate complexity. Our results reveal that VSL's nonlinearities may considerable deteriorate the performance of EnKF for Time-Averaged (TA) estimation, as compared to the utilization of a TA linear observation operator. Moreover, we show that this assimilation skill loss can be considerably reduced by embedding VSL's formulation into fuzzy logic theory, which fosters new interpretations of tree-ring growth limitation processes.

  9. Hydrologic inferences from ring widths of flood-damaged trees, Potomac River, Maryland

    USGS Publications Warehouse

    Yanosky, T.M.

    1982-01-01

    Year-to-year variability in the ring widths of trees on flood plains along two reaches of the Potomac River near Washington, D.C., seems in large part to be related to differences in flood-flow regimes. Trees directly exposed to high flood velocities are damaged more often than sheltered trees and thus exhibit more variable ring-width patterns. The ring-width variability of unsheltered trees on low levels of flood plains is greater than that of trees on high levels, indicating that variability values are positively correlated with flood frequency. Sheltered trees, however, have less variable ring-width patterns than those of unsheltered trees, and variability is not correlated with flood frequency. As a result, ring-width variations may be used to estimate the probability of flood damage along local channel reaches of a stream. Growth responses after hydrologic catastrophies in 1948 and 1972 indicate that rings of flood-plain trees can be used to document the occurrence and crest altitude of high-magnitude floods. ?? 1982 Springer-Verlag New York Inc.

  10. Hydrologic inferences from ring widths of flood-damaged trees, Potomac River, Maryland

    NASA Astrophysics Data System (ADS)

    Yanosky, Thomas M.

    1982-03-01

    Year-to-year variability in the ring widths of trees on flood plains along two reaches of the Potomac River near Washington, D.C., seems in large part to be related to differences in flood-flow regimes. Trees directly exposed to high flood velocities are damaged more often than sheltered trees and thus exhibit more variable ring-width patterns. The ring-width variability of unsheltered trees on low levels of flood plains is greater than that of trees on high levels, indicating that variability values are positively correlated with flood frequency. Sheltered trees, however, have less variable ring-width patterns than those of unsheltered trees, and variability is not correlated with flood frequency. As a result, ring-width variations may be used to estimate the probability of flood damage along local channel reaches of a stream. Growth responses after hydrologic catastrophies in 1948 and 1972 indicate that rings of flood-plain trees can be used to document the occurrence and crest altitude of high-magnitude floods.

  11. An overview of tree-ring width records across the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    St. George, Scott

    2014-07-01

    This review describes the structure and characteristics of the Northern Hemisphere tree-ring width network, and examines the associations between these data and key aspects of local climate and the global climate system. Even though all ring-width records describe the same aspect of tree growth, there are major regional differences in the nature and clarity of climate information preserved within these data across the hemisphere. In North America, many chronologies record climate variability during the growing season but winter precipitation also exerts a considerable and sometimes dominant control on tree-ring formation. Almost all ring-width records from Europe and Asia reflect the influence of climate during summer, with the effects of temperature being more prominent than precipitation. Mapping teleconnection patterns associated with major climate modes show that ENSO and the AMO have stronger and more consistent effects on tree growth than do the PDO, PNA, and NAO. The ENSO teleconnection, which seems to be communicated principally through its effect on winter precipitation, is evident within the highest number of ring-width records overall and is particularly strong in western North America. The AMO's expression in ring width is consistent across drought sensitive-records from the American Southwest and central Rocky Mountains, which may reflect its influence on moisture flux into the western interior of North America during summer. In comparison, the ring-width responses to the PDO, PNA, and NAO are less spatially coherent across the network and appear be connected through a more complex chain of causes linking climate modes, local climate and seasonal tree growth. Because the Northern Hemisphere ring-width network is now so large, it is more crucial than ever to ensure our understanding of tree-environment relations is not influenced by decisions to include or exclude certain records. As an initial step, it would be helpful if paleoclimate reconstructions

  12. [Chinese pine tree ring width chronology and its relations to climatic conditions in Qianshan Mountains].

    PubMed

    Chen, Zhen-Ju; Sun, Yu; He, Xing-Yuan; Chen, Wei; Shao, Xue-Mei; Zhang, Hua-Yu; Wang, Zhong-Yu; Liu, Xiao-Yu

    2007-10-01

    Taking Chinese pine in Qianshan Mountains as a sample, the tree ring width chronology including standard, residual, and Arstan chronologies was established. The results showed that the tree ring width of Chinese pine had a higher correlation with the temperature in May - July and in September - November, and significant positive correlations were observed between the tree ring width and the extreme minimum temperature in July and mean minimum temperature in September. The chronology had significant or very significant correlations with the extreme minimum temperature in December and next January, mean minimum temperature in January, annual precipitation, and the precipitation in April, May and last December. Chinese pine had stronger responses to the monthly/yearly water vapor pressure and relative humidity. The yearly and most monthly evaporation had negative effects on the growth, being most significant for the evaporation in April - July. The narrowed tree rings recorded by the chronology demonstrated the 30 times of extreme drought since 1 800. The growth of Chinese pine in Qianshan Mountains was also affected by the climate changes on global and hemisphere scales. There existed 11-, 23- and 50- year- common periodicity between the chronology and solar activity, and 10-, 20- and 45- year- common periodicity between the chronology and geomagnetic activity. PMID:18163297

  13. A Statistical Reconstruction of Bivariate Climate from Tree Ring Width Measurements Using Scientifically Motivated Process Models.

    NASA Astrophysics Data System (ADS)

    Tipton, J.; Hooten, M.; Pederson, N.; Tingley, M.; Bishop, D. A.

    2014-12-01

    The ability to reconstruct historical climate is important to understanding how climate has changed in the past. The instrumental record of temperature and precipitation only spans the most recent centuries. Thus, reconstructions of the climate features are typically based on proxy archives. The proxy archives integrate climate information through biological, geological, physical, and chemical processes. Tree ring widths provide one of the most spatially and temporally rich sources of high quality climate proxy data. However, the statistical reconstruction of paleoclimate from tree ring widths is quite challenging because the climate signal is inherently multi-dimensional while tree ring widths are a one dimensional data source. We propose a Bayesian Hierarchical model using a non-linear, scientifically motivated tree ring growth models to reconstruct multivariate climate (i.e., temperature and precipitation) in the Hudson Valley region of New York. Our proposed model extends and enhances former methods in a number of ways. We allow for species-specific responses to climate, which further constrains the many-to-one relationship between tree rings and climate. The resulting model allows for prediction of reasonable climate scenarios given tree ring widths. We explore a natural model selection framework that weighs the influence of multiple candidate growth models in terms of their predictive ability. To enable prediction backcasts, the climate variables are modeled with an underlying continuous time latent process. The continuous time process allows for added flexibility in the climate response through time at different temporal scales and enables investigation of differences in climate between the reconstruction period and the instrumental period. Validation of the model's predictive abilities is achieved through a pseudo-proxy simulation experiment where the quality of climate predictions are measured by out of sample performance based on a proper local scoring

  14. Towards the assimilation of tree-ring-width records using ensemble Kalman filtering techniques

    NASA Astrophysics Data System (ADS)

    Acevedo, Walter; Reich, Sebastian; Cubasch, Ulrich

    2016-03-01

    This paper investigates the applicability of the Vaganov-Shashkin-Lite (VSL) forward model for tree-ring-width chronologies as observation operator within a proxy data assimilation (DA) setting. Based on the principle of limiting factors, VSL combines temperature and moisture time series in a nonlinear fashion to obtain simulated TRW chronologies. When used as observation operator, this modelling approach implies three compounding, challenging features: (1) time averaging, (2) "switching recording" of 2 variables and (3) bounded response windows leading to "thresholded response". We generate pseudo-TRW observations from a chaotic 2-scale dynamical system, used as a cartoon of the atmosphere-land system, and attempt to assimilate them via ensemble Kalman filtering techniques. Results within our simplified setting reveal that VSL's nonlinearities may lead to considerable loss of assimilation skill, as compared to the utilization of a time-averaged (TA) linear observation operator. In order to understand this undesired effect, we embed VSL's formulation into the framework of fuzzy logic (FL) theory, which thereby exposes multiple representations of the principle of limiting factors. DA experiments employing three alternative growth rate functions disclose a strong link between the lack of smoothness of the growth rate function and the loss of optimality in the estimate of the TA state. Accordingly, VSL's performance as observation operator can be enhanced by resorting to smoother FL representations of the principle of limiting factors. This finding fosters new interpretations of tree-ring-growth limitation processes.

  15. Continuing upward trend in Mt Read Huon pine ring widths - Temperature or divergence?

    NASA Astrophysics Data System (ADS)

    Allen, K. J.; Cook, E. R.; Buckley, B. M.; Larsen, S. H.; Drew, D. M.; Downes, G. M.; Francey, R. J.; Peterson, M. J.; Baker, P. J.

    2014-10-01

    To date, no attempt has been made to assess the presence or otherwise of the “Divergence Problem” (DP) in existing multi-millennial Southern Hemisphere tree-ring chronologies. We have updated the iconic Mt Read Huon pine chronology from Tasmania, southeastern Australia, to now include the warmest decade on record, AD 2000-2010, and used the Kalman Filter (KF) to examine it for signs of divergence against four different temperature series available for the region. Ring-width growth for the past two decades is statistically unprecedented for the past 1048 years. Although we have identified a decoupling between temperature and growth in the past two decades, the relationship between some of the temperature records and growth has varied over time since the start of instrumental records. Rather than the special case of ‘divergence', we have identified a more general time-dependence between growth and temperature over the last 100 years. This time-dependence appears particularly problematic at interdecadal time scales. Due to the time-dependent relationships, and uncertainties related to the climate data, the use of any of the individual temperature series examined here potentially complicates temperature reconstruction. Some of the uncertainty in the climate data may be associated with changing climatic conditions, such as the intensification of the sub-tropical ridge (STR) and its impact on the frequency of anticyclonic conditions over the Mt Read site. Increased growth at the site, particularly in the last decade, over and above what would be expected based on a linear temperature model alone, may be consistent with a number of hypotheses. Existing uncertainties in the climate data need to be resolved and independent physiological information obtained before a range of hypotheses for this increased growth can be effectively evaluated.

  16. Chronomics of climatic variations of tree ring width

    NASA Astrophysics Data System (ADS)

    Otsuka, K.; Cornélissen, G.; Halberg, F.

    2010-12-01

    Variations in the average annual tree rings of 11 sequoia trees for 2189 years are studied. The power spectrum of tree ring variations, calculated by the Maximum Entropy Method (MEM), is power-law in character with the coefficient β close to -1.00, suggesting the fractal character of the considered time series. The calculations of the coefficient β in a 200-year sliding window showed that this coefficient rapidly drops to zero or very small positive values, indicating a break in the fractal structure in some intervals. We identified seven such episodes, two (the latest) of which correspond to Spörer and Maunder solar minima. The other five episodes, which occurred around 100 BC and 500, 700, 820, and 880 AD, i.e., before regular sunspot observations, may also correspond to climate changes. By combining methods aimed at identifying the specific spectral components, such as the Schwabe cycle and behavior of the 1/ f dependence as a chaos characteristic, the chronobiologic (chronomics) approach can be used to study the global climatic processes—such as cycles of about 500 years—bearing on global warming.

  17. Towards a common methodology to simulate tree mortality based on ring-width data

    NASA Astrophysics Data System (ADS)

    Cailleret, Maxime; Bigler, Christof; Bugmann, Harald; Davi, Hendrik; Minunno, Francesco; Peltoniemi, Mikko; Martínez-Vilalta, Jordi

    2015-04-01

    Individual mortality is a key process of population and community dynamics, especially for long-lived species such as trees. As the rates of vegetation background mortality and of massive diebacks accelerated during the last decades and would continue in the future due to rising temperature and increasing drought, there is a growing demand of early warning signals that announce that the likelihood of death is very high. If physiological indicators have a high potential to predict tree mortality, their development requires an intensive tree monitoring which cannot be currently done on a representative sample of a population and on several species. An easier approach is to use radial growth data such as tree ring-widths measurements. During the last decades, an increasing number of studies aimed to derive these growth-mortality functions. However, as they followed different approaches concerning the choice of the sampling strategy (number of dead and living trees), of the type of growth explanatory variables (growth level, growth trend variables…), and of the length of the time-window (number of rings before death) used to calculate them, it makes difficult to compare results among studies and a subsequent biological interpretation. We detailed a new methodology for assessing reliable tree-ring based growth-mortality relationships using binomial logistic regression models. As examples we used published tree-ring datasets from Abies alba growing in 13 different sites, and from Nothofagus dombeyi and Quercus petraea located in one single site. Our first approach, based on constant samplings, aims to (1) assess the dependency of growth-mortality relationships on the statistical sampling scheme used; (2) determine the best length of the time-window used to calculate each growth variable; and (3) reveal the presence of intra-specific shifts in growth-mortality relationships. We also followed a Bayesian approach to build the best multi-variable logistic model considering

  18. Development of narrow width type oil control ring for motorcycle engine

    SciTech Connect

    Tateishi, Yukio; Fujimura, Kazuhiro; Ishihara, Katsushi; Watanabe, Masanor

    1995-12-31

    The reduction of piston ring friction forces, which account for high percentages of the total engine friction loss, is vital for the simultaneous attainments of lower fuel consumption, higher engine power and speed. The authors et al. noted a three-piece type oil control ring in this study, and strived for the development of an oil control ring with a narrow width and a low tangential force. A new three-piece, type oil control ring with a small tolerance on tangential force and a width of 1.2 to 1.5 mm has been successfully developed by studying the effect of such a ring on the lubricating oil consumption, while providing a spring function by press-forming a wire rod having a particular sectional shape.

  19. Climate reconstructions from tree-ring widths for the last 850 years in Northern Poland

    NASA Astrophysics Data System (ADS)

    Heinrich, Ingo; Knorr, Antje; Heußner, Karl-Uwe; Wazny, Tomasz; Slowinski, Michal; Helle, Gerhard; Simard, Sonia; Scharnweber, Tobias; Buras, Allan; Beck, Wolfgang; Wilmking, Martin; Brauer, Achim

    2015-04-01

    Tree-ring based temperature reconstructions form the scientific backbone of the current debate over global change, and they are the major part of the palaeo data base used for the IPCC report. However, long temperature reconstructions derived from temperate lowland trees growing well within their distributional limits in central Europe are not part of the IPCC report, which is an essential gap in the international data base. It appears that dendroclimatological analysis at temperate lowland sites was so far difficult to perform mainly for three reasons: diffuse climate-growth relationships, the lack of long chronologies due to absence of sufficient numbers of long-living trees and the potential loss of low-frequency signals due to the short length of the sample segments. We present two robust multi-centennial reconstructions of winter temperatures and summer precipitation based on pine and oak tree-ring widths chronologies from northern Poland, where so far no long tree-ring based reconstructions were available. We compared the new records with global, hemispherical and regional reconstructions, and found good agreement with some of them. In comparison, the winter temperature of our reconstruction, however, did not indicate any modern warming nor did the summer precipitation reconstruction suggest any modern 20th century changes. In a second step, we measured cell structures and developed chronologies of parameters such as cell wall thickness and cell lumen area. We used our new method (Liang et al. 2013a,b) applying confocal laser scanning microscopy to increment core surfaces for efficient histometric analyses. We focused on samples covering the last century because meteorological data necessary for calibration studies were available for direct comparisons. It was demonstrated that the correlations with climate were strong and different from those found for tree-ring widths (e.g., N-Poland oak-vessel-lumen-area-chronology with previous September-to-December mean

  20. North Patagonia climate over the last millennium inferred from variations in tree-ring width and isotopic composition

    NASA Astrophysics Data System (ADS)

    Lavergne, Aliénor; Villalba, Ricardo; Daux, Valérie

    2014-05-01

    To disentangle natural variability from man-induced climate changes, current climatic trends should be placed in a longer perspective. Tree-rings provide a wealth of information on past climates with high-resolution records covering up to thousands years. Recent tree-ring studies have highlighted the divergence phenomenon in Northern Hemisphere forests. At some temperature-limited northern sites, tree growth responses to climate during recent decades have changed, raising concerns about the quality of historical climate reconstructions based on tree-ring widths. This shift in the eco-physiological response of trees to climate has not yet been documented in the Southern Hemisphere. The aim of this study is to present the tree-ring evolution over the last centuries in northern Patagonia (southern South America; 41° 10'S-71° 50'W) in order to assess 1) divergence in tree-growth response to climate in recent decades, and 2) the potential of tree-ring parameters (width and δ18O) to reconstruct temperature and atmospheric circulation patterns such as the Southern Annular Mode (SAM). Based on quality and extent, instrumental temperature records across North Patagonia (39° -41° S) were selected for comparison with tree-ring records. Detection and correction of series inhomogeneities were conducted using HOMER software. A set of homogenized temperature data was developed for the period 1901-2013. Increment-borer samples from Fitzroya cupressoides and Nothofagus pumilio were collected along the regional precipitation gradient from the wet Valdivian rainforest to the mesic Patagonian forests during the austral summer of 2013. Six sampling sites (2 for Fitzroya, 4 for Nothofagus) along the gradient were established to maximize differences in tree-growth responses to climate and to assess the effect of precipitation on the responses. More than 500 cores were cross-dated, detrended and indexed. Composite tree-ring index (TRI) chronologies of F. cupressoides and N. pumilio

  1. Domain wall width of lithium niobate poled during growth

    NASA Astrophysics Data System (ADS)

    Brooks, R.; Townsend, P. D.; Hole, D. E.; Callejo, D.; Bermúdez, V.; Diéguez, E.

    2003-04-01

    Good quality crystals of periodically poled lithium niobate can be generated directly during growth. However, the temperature gradients at the zone boundaries define the width of the regions where the polarity is reversed. Hence, the region influenced the domain transition may be a significant fraction of the overall poling period for material poled during growth. Evidence for the scale of this feature is reported both by chemical etching and by the less common method of ion beam luminescence and the `domain wall' width approximately 1 mum for these analyses. The influence of the reversal region may differ for alternative techniques but the relevance to device design for second harmonic generation is noted.

  2. Do coralline red algal growth increment widths archive paleoenvironmental information?

    NASA Astrophysics Data System (ADS)

    Halfar, J.; Winsborough, C.; Omar, A.; Hetzinger, S.; Steneck, R. S.; Lebednik, P. A.

    2009-04-01

    Over the past decade coralline red algae have received increased attention as archives of paleoclimate information. Encrusting coralline red algae, which deposit annual growth increments in a High-Mg calcite skeleton, are amongst the longest-lived marine organisms. In fact, a live-collected plant has recently been shown to have lived for at least 850 years based on radiometric dating. While a number of investigations have successfully utilized geochemical information obtained from coralline red algal skeletons to reconstruct climate, no study has yet examined the potential of using growth increment widths as a proxy for past water temperatures. Here we explore the relationship between growth and environmental parameters in Clathromorphum nereostratum from the Bering Sea. A 120-year long annual growth record shows a significant but weak correlation to regional sea surface temperature data (r=0.24), which requires much of the observed annual growth increment width variability to be explained by other factors. We therefore examined coralline red algal growth for a 20-year period in multiple specimens collected along a depth transect from 10 to 35 m water depth. Results demonstrate a significant decrease in average annual growth increment widths with increasing water depth. Due to intense wind-induced mixing in the region the upper water column exhibits near uniform temperatures and salinities, leaving the decreasing amount of light with depth as the dominant variable influencing vertical extension. This was further tested by examining specimens collected at 10 m water depth at different locations receiving distinct amounts of shading provided by 100%, 50%, and 0% kelp canopy coverage. Results indicate a negative relationship between percent kelp canopy coverage and annual growth increment width. It can therefore be concluded that the dominant factor controlling vertical growth in C. nereostratum is light, with temperature only accounting for a small portion of growth

  3. Teasing Foggy Memories out of Pines on the California Channel Islands Using Tree-Ring Width and Stable Isotope Approaches

    NASA Astrophysics Data System (ADS)

    Williams, A. P.; Still, C. J.; Fischer, D. T.; Leavitt, S. W.

    2006-12-01

    The coast of California is home to many rare, endemic conifers and other plants that are not well adapted to the Mediterranean climate that prevails across most of the state. It has long been suggested that coastal pines survived the early-Pleistocene transition to a warmer and drier environment because they benefit from frequent fog and low stratus clouds that provide much needed water inputs and shading during the rainless summer. Here, we report evidence for the importance of this summer cloudiness to Torrey pines (Pinus torreyana) growing on Santa Rosa Island in Channel Islands National Park. We developed a tree-ring width chronology and quantified the relative importance of winter/spring precipitation and summer fog by comparing ring widths to nearby rainfall records and airport cloud-ceiling height data. While winter/spring precipitation explains most of the variation in annual tree-ring width (R2 = 0.592), the frequency of summertime fog correlated significantly and positively with annual ring width for 52 years of available fog data when the effect of winter/spring precipitation was removed (R2 = 0.118). The correlation between fog frequency and ring width decreased sharply when the range of possible cloud-ceiling heights deviated from the habitat range of the Torrey pine stand, emphasizing the importance of direct cloud immersion to these pines. In addition, the relationship between fog frequency and ring width was strongest in the 26 years that had enough winter/spring rainfall to maintain above-average soil moisture throughout the dry summer months (R2 = 0.312). This suggests that Torrey pines have an adaptive growing season length and that summer fog-water inputs are supplemental but not substantial enough to sustain tree growth independently. It may also be suggested that when summer growth does occur, the frequency of summer fog and stratus may govern growing season length. This made a "fog signal" difficult to detect in the stable isotope (carbon and

  4. Alternative standardization approaches to improving streamflow reconstructions with ring-width indices of riparian trees

    USGS Publications Warehouse

    Meko, David M; Friedman, Jonathan M.; Touchan, Ramzi; Edmondson, Jesse R.; Griffin, Eleanor R.; Scott, Julian A.

    2015-01-01

    Old, multi-aged populations of riparian trees provide an opportunity to improve reconstructions of streamflow. Here, ring widths of 394 plains cottonwood (Populus deltoids, ssp. monilifera) trees in the North Unit of Theodore Roosevelt National Park, North Dakota, are used to reconstruct streamflow along the Little Missouri River (LMR), North Dakota, US. Different versions of the cottonwood chronology are developed by (1) age-curve standardization (ACS), using age-stratified samples and a single estimated curve of ring width against estimated ring age, and (2) time-curve standardization (TCS), using a subset of longer ring-width series individually detrended with cubic smoothing splines of width against year. The cottonwood chronologies are combined with the first principal component of four upland conifer chronologies developed by conventional methods to investigate the possible value of riparian tree-ring chronologies for streamflow reconstruction of the LMR. Regression modeling indicates that the statistical signal for flow is stronger in the riparian cottonwood than in the upland chronologies. The flow signal from cottonwood complements rather than repeats the signal from upland conifers and is especially strong in young trees (e.g. 5–35 years). Reconstructions using a combination of cottonwoods and upland conifers are found to explain more than 50% of the variance of LMR flow over a 1935–1990 calibration period and to yield reconstruction of flow to 1658. The low-frequency component of reconstructed flow is sensitive to the choice of standardization method for the cottonwood. In contrast to the TCS version, the ACS reconstruction features persistent low flows in the 19th century. Results demonstrate the value to streamflow reconstruction of riparian cottonwood and suggest that more studies are needed to exploit the low-frequency streamflow signal in densely sampled age-stratified stands of riparian trees.

  5. 400+ Years of ENSO-like Climate Cyclicity from Tree Ring Width-Data, Wind River Range, Wyoming, USA.

    NASA Astrophysics Data System (ADS)

    Dahms, D. E.; Richards, D.; Pease, P.

    2014-12-01

    Spectral analysis of detrended ring-width data from a series of +400-year-old Douglas Firs on the SE flank of the Wind River Range indicates that tree growth from 1589-to-2013 shows a 2.5-to-4.5-year cyclicity (99%). This is within the limits of the generally accepted ~2-7 year ENSO cyclicity of the western Pacific. Our results also show a 16-year frequency (95%) suggesting possible additional influence from the Pacific Decadal Oscillation (PDO). Ring-widths here are most closely correlated to soil moisture conditions through the interaction(s) of abundant winter snowpack, summer rainfall, and average May-August temperatures during the 424-years from 1589-2013. Nearby climate records from the 1948-2013 period show that more favorable growth conditions exist here (higher snowpack+summer precipitation) during the El Niño cycle of ENSO. Our results fill a gap in knowledge of ENSO-like teleconnections during the Late Holocene that exists for the southern region of the Greater Yellowstone Ecosystem.

  6. Moisture-sensitive tree-ring widths from the Craters of the Moon lava-complex in east central, Idaho

    NASA Astrophysics Data System (ADS)

    Crawford, C. J.; Kipfmueller, K. F.; St George, S.

    2011-12-01

    Craters of the Moon (COM) National Monument is a basaltic volcanic complex on the eastern Snake River Plain that has formed over eight eruptive periods during the Holocene. Since the last eruption, limber pine (Pinus flexilis) and Douglas-fir (Pseudotsuga menziesii Mirb Franco.) have established on lava flows and ancient weathered cinder cones. These rare long-lived trees have survived for 400 - 1000 years on well-drained porous rock, inviting the possibility that tree-ring widths will show elevated moisture sensitivity. Four tree-ring records have been constructed from living trees and remnant wood that include limber pine total ring-width (937-2009 AD), Douglas-fir total ring-width, and partial earlywood and latewood widths (1468-2009 AD). During 1550-2009 AD, the covariance between records is moderately significant (0.31-0.34, p<0.01) for standard chronologies, but residual chronologies show little association (0.05-0.08). Monte-Carlo correlations between tree-ring widths and instrumental climate data (1930-2009) indicate that annual precipitation (prior Jun. - May) is correlated (p<0.01) with limber pine and Douglas-fir standard ring-width, and seasonal precipitation is correlated (p<0.01) with residual limber pine ring-width (prior Jul. - prior Dec.) and residual Douglas-fir earlywood width (Jan. - Jun). Because cool-season precipitation dominates the annual hydrological budget for the COM region, total ring-width persistence is primarily tuned to total annual precipitation while residual variance appears to reflect seasonal differences between the amount of prior fall - winter and winter - spring season moisture. So far, COM tree-ring records seem well suited as candidate predictors for paleoclimate reconstructions of not only annual precipitation, but also seasonally partitioned precipitation at interannual-decadal timescales.

  7. Boreal temperature variability inferred from maximum latewood density and tree-ring width data, Wrangell Mountain region, Alaska

    NASA Astrophysics Data System (ADS)

    Davi, Nicole K.; Jacoby, Gordon C.; Wiles, Gregory C.

    2003-11-01

    Variations in both width and density of annual rings from a network of tree chronologies were used to develop high-resolution proxies to extend the climate record in the Wrangell Mountain region of Alaska. We developed a warm-season (July-September) temperature reconstruction that spans A.D. 1593-1992 based on the first eigenvector from principal component analysis of six maximum latewood density (MXD) chronologies. The climate/tree-growth model accounts for 51% of the temperature variance from 1958 to 1992 and shows cold in the late 1600s-early 1700s followed by a warmer period, cooling in the late 1700s-early 1800s, and warming in the 20th century. The 20th century is the warmest of the past four centuries. Several severely cold warm-seasons coincide with major volcanic eruptions. The first eigenvector from a ring-width (RW) network, based on nine chronologies from the Wrangell Mountain region (A.D. 1550-1970), is correlated positively with both reconstructed and recorded Northern Hemisphere temperatures. RW shows a temporal history similar to that of MXD by increased growth (warmer) and decreased growth (cooler) intervals and trends. After around 1970 the RW series show a decrease in growth, while station data show continued warming, which may be related to increasing moisture stress or other factors. Both the temperature history based on MXD and the growth trends from the RW series are consistent with well-dated glacier fluctuations in the Wrangell Mountains and some of the temperature variations also correspond to variations in solar activity.

  8. [Vertical variability of Pinus sylvestris var. mongolica tree ring delta13C and its relationship with tree ring width in northern Daxing' an Mountains of Northeast China].

    PubMed

    Shang, Zhi-Yuan; Wang, Jian; Zhang, Wen; Li, Yan-Yan; Cui, Ming-Xing; Chen, Zhen-Ju; Zhao, Xing-Yun

    2013-01-01

    A measurement was made on the vertical direction tree ring stable carbon isotope ratio (delta13C) and tree ring width of Pinus sylvestris var. mongolica in northern Daxing' an Mountains of Northeast China, with the relationship between the vertical direction variations of the tree ring delta13C and tree ring width analyzed. In the whole ring of xylem, earlywood (EW) and bark endodermis, the delta13C all exhibited an increasing trend from the top to the base at first, with the maximum at the bottom of tree crown, and then, decreased rapidly to the minimum downward. The EW and late-wood (LW) had an increasing ratio of average tree ring width from the base to the top. The average annual sequence of the delta13C in vertical direction had an obvious reverse correspondence with the average annual sequence of tree ring width, and had a trend comparatively in line with the average annual sequence of the tree ring width ratio of EW to LW above tree crown. The variance analysis showed that there existed significant differences in the sequences of tree ring delta13C and ring width in vertical direction, and the magnitude of vertical delta13C variability was basically the same as that of the inter-annual delta13C variability. The year-to-year variation trend of the vertical delta13C sequence was approximately identical. For each sample, the delta13C sequence at the same heights was negatively correlated with the ring width sequence, but the statistical significance differed with tree height. PMID:23717983

  9. Optical tweezers assisted imaging of the Z-ring in Escherichia coli: measuring its radial width

    NASA Astrophysics Data System (ADS)

    Carmon, G.; Kumar, P.; Feingold, M.

    2014-01-01

    Using single-beam, oscillating optical tweezers we can trap and rotate rod-shaped bacterial cells with respect to the optical axis. This technique allows imaging fluorescently labeled three-dimensional sub-cellular structures from different, optimized viewpoints. To illustrate our method we measure D, the radial width of the Z-ring in unconstricted Escherichia coli. We use cells that express FtsZ-GFP and have their cytoplasmic membrane stained with FM4-64. In a vertically oriented cell, both the Z-ring and the cytoplasmic membrane images appear as symmetric circular structures that lend themselves to quantitative analysis. We found that D ≅ 100 nm, much larger than expected.

  10. Multicentury Reconstruction of Precipitations (1300-2014) in Eastern Canada from Tree-Ring Width and Carbon and Oxygen Isotopes

    NASA Astrophysics Data System (ADS)

    Giguère, Claudie; Boucher, Étienne; Bergeron, Yves

    2016-04-01

    Tree ring series enabling long hydroclimatic reconstructions are scarce in Northeastern America, mostly because most boreal species are rather thermo-dependant. Here we propose a new multi-proxy analysis (tree-ring, δ13C and δ18O) from one of the oldest Thuja occidentalis population in NE America (lake Duparquet, Quebec). These rare precipitation-sensitive, long-living trees (> 800 years) grow on xeric rocky shores and their potential for paleo-hydroclimatic reconstructions (based on ring widths solely) was previously assessed. The objectives of this study are twofold i) to strengthen the hydroclimatic signal of this long tree-ring chronology by adding analysis of stable isotope ratios (δ13C and δ18O) and ii) to reconstruct summer precipitation back to 1300 AD, which will represent, by far, the longest high-resolution hydroclimatic reconstruction in this region. A tree-ring chronology was constructed from 61 trees sampled in standing position. Eleven trees were also sampled to produce pooled carbon and oxygen isotope chronologies (annually resolved) with a replication of five to six trees per year. Signal analysis (correlation between climatic data and proxy values) confirms that growth is positively influenced by spring precipitations (May-June), while δ13C is negatively correlated to summer precipitation (June to August) and positively to June temperature. Adding δ18O analysis will strengthen the signal even more, since wood cellulose should be enriched in δ18O when high evapotranspiration conditions prevail. Based on a multi-proxy approach, a summer precipitation reconstruction was developed and compared to other temperature reconstructions from this region as well as to southernmost hydroclimatic reconstructions (e.g. Cook et al). A preliminary analysis of external and internal forcing is proposed in conclusion.

  11. Solar and climate signal records in tree ring width from Chile (AD 1587 1994)

    NASA Astrophysics Data System (ADS)

    Rodolfo Rigozo, Nivaor; Roger Nordemann, Daniel Jean; Evangelista da Silva, Heitor; Pereira de Souza Echer, Mariza; Echer, Ezequiel

    2007-01-01

    Tree growth rings represent an important natural record of past climate variations and solar activity effects registered on them. We performed in this study a wavelet analysis of tree ring samples of Pilgerodendron cupressoides species, from Glaciar Pio XI (Lat: 49°12'S; 74°55'W; Alt: 25 m), Chile. We obtained an average chronology of about 400 years from these trees. The 11-yr solar cycle was present during the whole period in tree ring data, being more intense during Maunder minimum (1645-1715). The short-term periods, around 2-7 yr, that were found are more likely associated with ENSO effects. Further, we found significant periods around 52 and 80-100 yr. These periodicities are coincident with the fourth harmonic (52 yr) of the Suess cycle (208 yr) and Gleissberg (˜80-100 yr) solar cycles. Therefore, the present analysis shows evidence of solar activity effect/modulation on climatic conditions that affect tree ring growth. Although we cannot say with the present analysis if this effect is on local, regional or global climate, these results add evidence to an important role of solar activity over terrestrial climate over the past ˜400 yr.

  12. Inferring long-term carbon sequestration from tree rings at Harvard Forest: A calibration approach using tree ring widths and geochemistry / flux tower data

    NASA Astrophysics Data System (ADS)

    Belmecheri, S.; Maxwell, S.; Davis, K. J.; Alan, T. H.

    2012-12-01

    Improving the prediction skill of terrestrial carbon cycle models is important for reducing the uncertainties in global carbon cycle and climate projections. Additional evaluation and calibration of carbon models is required, using both observations and long-term proxy-derived data. Centennial-length data could be obtained from tree-rings archives that provide long continuous series of past forest growth changes with accurate annual resolution. Here we present results from a study conducted at Harvard Forest (Petersham, Massachusetts). The study examines the potential relationship between δ13C in dominant trees and GPP and/or NEE measured by the Harvard Forest flux tower (1992-2010). We have analyzed the δ13C composition of late wood-cellulose over the last 18 years from eastern hemlock (Tsuga canadensis) and northern red oak (Quercus rubra) trees growing in the flux tower footprint. δ13C values, corrected for the declining trend of atmospheric δ13C, show a decreasing trend from 1992 to 2010 and therefore a significant increase in discrimination (Δ). The intra-cellular CO2 (Ci) calculated from Δ shows a significant increase for both tree species and follows the same rate of atmospheric CO2 (Ca) increase (Ci/Ca increases). Interestingly, the net Ci and Δ increase observed for both species did not result in an increase of the iWUE. Ci/Ca is strongly related to the growing season Palmer Drought Severity Index (PDSI) for both species thus indicating a significant relationship between soil moisture conditions and stomatal conductance. The Ci trend is interpreted as a result of higher CO2 assimilation in response to increasing soil moisture allowing a longer stomata opening and therefore stimulating tree growth. This interpretation is consistent with the observed increase in GPP and the strengthening of the carbon sink (more negative NEE). Additionally, the decadal trends of basal area increment (BAI) calculated from tree-ring widths exhibit a positive trend over

  13. Ensemble empirical mode decomposition as a tool of lake sediments and tree-ring width chronologies investigation

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Dmitriy; Mordvinov, Alexandr; Kalugin, Ivan; Darin, Andrey; Myglan, Vladimir

    2014-05-01

    A method named ensemble empirical mode decomposition (EEMD) was used to analyse different paleoclimatic data such as non-varved lake sediments of the Teletskoye lake and long tree-ring width chronologies from the Altai region (Altai Mountains, South Siberia, Russia) in the late Holocene (2000 years). Core of the bottom sediments from the Teletskoe lake (Altai Mountains) were investigated using scanning X-ray fluorescent analysis method with synchrotron radiation (spatial resolution is 0.1 mm). Low-frequency signals (modes) were extracted from both paleoarchives and shown: ~ 60, ~ 100, ~ 200, ~ 300-500 and ~1000-year cycles in the Teletskoye lake; ~ 25-33, ~ 50-60, ~100- 200, ~ 300 and ~ 1000 year cycles in tree-ring width chronologies. A common 200-year cycle was found in both archives. Also EEMD method was used to analyse a solar-activity during late Holocene. The magnetic solar activity well associated with tree-ring width chronologies. Changes of the tree-ring width chronology on the millennial time scale coincide with similar changes of the solar activity in the Holocene. Stable relationships between solar activity and climate characteristics are found on 100-200 years time scales (Glaysberg and Suess cycles). The magnetic solar activity and paleotemperature changes are observed as solar-terrestrial relations on a large time scale. It is indicate that the temperature increase in the 19-20 centuries is largely due to the impact of solar activity on the Earth's climate system. Solar-terrestrial relations analysis shown common 200-year cycle in all presented paleoarchives. The study was funded by: Interdisciplinary Integration Project SB RAS # 34 and grants # 13-05-00620 from the Russian Foundation for Basic Research. Key words: ensemble empirical mode decomposition (EEMD), lake sediments, tree-ring width chronologies, solar-terrestrial relations

  14. Two centuries temperature variations over subtropical southeast China inferred from Pinus taiwanensis Hayata tree-ring width

    NASA Astrophysics Data System (ADS)

    Cai, QiuFang; Liu, Yu

    2016-05-01

    High-resolution long-term temperature reconstructions in subtropical southeast China (SSC) are very scarce, yet indispensable for the comprehensive understanding of climate change in China, even in East Asia. We reconstructed the first previous growth-season temperature in the Sanqingshan Mountains (SQS), southeast China since 1806 based on tree-ring width data. The reconstruction accounts for 56.4 % of the total variance in the instrumental record over 1954-2009. Unlike the Northern Hemispheric warming during recent two centuries, the reconstruction captured a slowly cooling trend from 1806 to 1980, followed by a rapid warming afterward. 2003-2009 was the warmest period in the reconstruction. 1970-2000 was colder than the last stage of the Little Ice Age (LIA). Most of the warm and cold periods in this reconstruction could be found in the tree-ring based temperature reconstructions of vicinity area, indicating that the temperature variations in SSC were almost synchronous at least at decadal scale. This regional coherence of temperature variation was further confirmed by the spatial correlation patterns with the CRU TS3.22 grid dataset. A strong positive relationship between the temperature over SQS region and sea surface temperature (SST) over the North Pacific Ocean (NP) has been noted, suggesting that SST variations over NP and the related Pacific Decadal Oscillation significantly influenced the temperature variability over SSC. To better understand the climate variability during the LIA and the regional differences in temperature variations over SQS and northern Hemisphere, long data sets from more diverse areas of southern China are needed.

  15. Occurrence of annual growth rings in Rhizophora mangle in a region with low climate seasonality.

    PubMed

    Souza, Brunna T; Estrada, Gustavo C D; Soares, Mário L G; Callado, Cátia H

    2016-01-01

    The formation of annual growth rings has been confirmed for several mangrove species in the last decade, among which is the Rhizophora mangle. However, the record of annual rings for this species was made in a region with high hydric seasonality, a widely recognized induction factor of annual rings in tropical species. In this sense, the present study aimed to verify the occurrence of annual growth rings in R. mangle in the mangroves of Guaratiba (Rio de Janeiro, Southeastern Brazil), a region with low hydric seasonality. For this purpose, the crossdating technique was applied in ten trees collected with known age (seven years). The growth rings are characterized by alternating layers of low vessel density (earlywood) and high vessel density (latewood). Multiple regression analysis indicated that growth rings width variation is driven by precipitation, water surplus, water deficit and water storage. Crossdating analysis confirmed the existence of annual growth rings in the R. mangle in Guaratiba. This discovery in a region with low hydric seasonality increases the dendrocronological potential of this species and suggests the importance of biological factors (eg. phenological behavior) as complementary inductors for the formation of growth rings in this species. PMID:27142552

  16. Interpretation of tree-ring data with a model for primary production, carbon allocation and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Wang, H.; Harrison, S. P.; Prentice, I. C.

    2013-12-01

    We present a simple, generic model of annual tree growth, called ';T'. This model accepts input from a generic light-use efficiency model which is known to provide good simulations of terrestrial carbon exchange. The light-use efficiency model provides values for Gross Primary Production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport-tissue, and fine-root production and respiration, in such a way as to satisfy well-understood dimensional relationships. The result is a model that can represent both ontogenetic effects and the effects of environmental variations and trends on growth. The model has been applied to simulate ring-width series from multiple individual trees in temperature- and drought-limited contexts. Each tree is initialized at its actual diameter at the time when local climate records started. These records are used to drive the trees' subsequent growth. Realistic simulations of the pattern of interannual variability of ring-width are generated, and shown to relate statistically to climate. An upward trend in ring-width during 1958-2007 is shown to be present in the primary observations, and in the simulations; but not in the standard, detrended ring-width series. This approach combines two modelling approaches previously developed in the global carbon cycle and forest science literature respectively. Neither has been widely applied in the context of tree-ring based climate reconstruction. This combination of methods offers promise, however, because it could provide a way to sidestep several known problems. These include: reliance on correlations for the interpretation of ring-width variations in terms of climate; the necessity of detrending using empirical functions (which can remove trends caused by variations in the environment as well as those that are ontogenetic); and the difficulty of assessing effects of extrinsic, non

  17. Solar and Climate Variation Relationships Analyzed from Chile Tree Ring Width Time Series (1587 - 1994 A.D.)

    NASA Astrophysics Data System (ADS)

    Rigozo, Nr; Nordemann, Djr; Faria, Hh; Echer, E.; Vieira, Lea; Prestes, A.

    This work presents a study of the relations between solar and climate variations during the last four centuries by spectral analysis of tree ring index and sunspot number time series. Trees used for this study were Pilgerodendron cupressoides from Glaciar Pio XI, in Chile. The spectral analysis of tree ring index shows that 11, 22 and 80 year periodicities of the solar cycle were present in this tree ring data with 0.95 confidence level. This result suggests a solar modulation of climate variations, as recorded by the tree ring growth. Short-term variations, between 2 - 7 years, are also present in tree ring data. Therefore spectral analysis clearly shows that both, solar and climate factors, are recorded in the tree ring data.

  18. Did the late spring frost in 2007 and 2011 affect tree-ring width and earlywood vessel size in Pedunculate oak (Quercus robur) in northern Poland?

    NASA Astrophysics Data System (ADS)

    Puchałka, Radosław; Koprowski, Marcin; Przybylak, Julia; Przybylak, Rajmund; Dąbrowski, Henryk P.

    2015-11-01

    Trees are sensitive to extreme weather and environmental conditions. This sensitivity is visible in tree-ring widths and cell structure. In our study, we hypothesized that the sudden frost noted at the beginning of May in both 2007 and 2011 affected cambial activity and, consequently, the number and size of vessels in the tree rings. It was decided to test this hypothesis after damage to leaves was observed. The applied response function model did not show any significant relationships between spring temperature and growth. However, this method uses average values for long periods and sometimes misses the short-term effects. This is why we decided to study each ring separately, comparing them with rings unaffected by the late frost. Our study showed that the short-term effect of sudden frost in late spring did not affect tree rings and selected cell parameters. The most likely reasons for this are (i) cambial activity producing the earlywood vessels before the occurrence of the observed leaf damage, (ii) the forest micro-climate protecting the trees from the harsh frost and (iii) the temperature decline being too short-lived an event to affect the oaks. On the other hand, the visible damage may be occasional and not affect cambium activity and tree vitality at all. We conclude that oak is well-adapted to this phenomenon.

  19. Did the late spring frost in 2007 and 2011 affect tree-ring width and earlywood vessel size in Pedunculate oak (Quercus robur) in northern Poland?

    PubMed

    Puchałka, Radosław; Koprowski, Marcin; Przybylak, Julia; Przybylak, Rajmund; Dąbrowski, Henryk P

    2016-08-01

    Trees are sensitive to extreme weather and environmental conditions. This sensitivity is visible in tree-ring widths and cell structure. In our study, we hypothesized that the sudden frost noted at the beginning of May in both 2007 and 2011 affected cambial activity and, consequently, the number and size of vessels in the tree rings. It was decided to test this hypothesis after damage to leaves was observed. The applied response function model did not show any significant relationships between spring temperature and growth. However, this method uses average values for long periods and sometimes misses the short-term effects. This is why we decided to study each ring separately, comparing them with rings unaffected by the late frost. Our study showed that the short-term effect of sudden frost in late spring did not affect tree rings and selected cell parameters. The most likely reasons for this are (i) cambial activity producing the earlywood vessels before the occurrence of the observed leaf damage, (ii) the forest micro-climate protecting the trees from the harsh frost and (iii) the temperature decline being too short-lived an event to affect the oaks. On the other hand, the visible damage may be occasional and not affect cambium activity and tree vitality at all. We conclude that oak is well-adapted to this phenomenon. PMID:26607274

  20. Did the late spring frost in 2007 and 2011 affect tree-ring width and earlywood vessel size in Pedunculate oak ( Quercus robur) in northern Poland?

    NASA Astrophysics Data System (ADS)

    Puchałka, Radosław; Koprowski, Marcin; Przybylak, Julia; Przybylak, Rajmund; Dąbrowski, Henryk P.

    2016-08-01

    Trees are sensitive to extreme weather and environmental conditions. This sensitivity is visible in tree-ring widths and cell structure. In our study, we hypothesized that the sudden frost noted at the beginning of May in both 2007 and 2011 affected cambial activity and, consequently, the number and size of vessels in the tree rings. It was decided to test this hypothesis after damage to leaves was observed. The applied response function model did not show any significant relationships between spring temperature and growth. However, this method uses average values for long periods and sometimes misses the short-term effects. This is why we decided to study each ring separately, comparing them with rings unaffected by the late frost. Our study showed that the short-term effect of sudden frost in late spring did not affect tree rings and selected cell parameters. The most likely reasons for this are (i) cambial activity producing the earlywood vessels before the occurrence of the observed leaf damage, (ii) the forest micro-climate protecting the trees from the harsh frost and (iii) the temperature decline being too short-lived an event to affect the oaks. On the other hand, the visible damage may be occasional and not affect cambium activity and tree vitality at all. We conclude that oak is well-adapted to this phenomenon.

  1. Multi-proxy approaches to isolating low-frequency climate signals from tree-ring δ13C, δ18O and ring-widths

    NASA Astrophysics Data System (ADS)

    Voelker, S. L.; Johnstone, J. A.; Roden, J. S.; Dawson, T. E.

    2013-12-01

    Tree-ring stable isotope records have been increasingly used as climate proxies and have often improved the coherence of climate signals compared to ring-width variability. Here we explore the potential for combining tree ring 13C, 18O and ring-width data to isolate low-frequency climate variation from 1) bur oak trees from mid-continental USA and 2) coastal California redwood trees. For modern mid-continental oaks, Δ13C [carbon isotope discrimination] and Δ18O [isotopic enrichment above source water] are negatively correlated across space and time, conditions representative of the bioclimatic envelope for this species. Correlations with the vapor pressure deficit at the growing season maximum temperature (VPDmax) were greatest for the dual isotopic signal as compared to Δ13C or Δ18O alone (r = 0.79, 0.69 and 0.75, respectively). As applied to 59 sub-fossil oak logs [14C-dated to 9.97-13.64k Cal yrs BP] from Missouri, USA, this dual isotope signal indicates that the Pleistocene-Holocene transition was characterized by an abrupt transition near the end of the Younger-Dryas period from a cold, wet and relatively stable growing season climate to a more variable early Holocene climate characterized by periods of greater growing season VPD and maximum temperatures. Our data further suggest that correlations between Δ13C or Δ18O and ring-width chronologies may provide a record of decadal to multi-decadal variability in VPDmax. For coastal California redwoods, from 1951-2003, we demonstrate drastic differences in both sign and magnitude of 11-year running correlations between northern California regional Δ13C or δ18O chronologies for 'middlewood' or 'latewood' (MW or LW) and a regional ring-width chronology. Comparisons of trends in these correlations to 11-year means of Pacific Decadal Oscillation index (PDO, May-September) show similarities with MW or LW Δ13C (r = 0.70 and 0.53, respectively) and stronger correspondence with inverted MW and LW δ18O (r = 0

  2. Using Novel Approaches in Process-Based Modeling for Interpreting Inter-Annual Variability in Tree Ring Widths, Wood Density Profiles, and Cellulose Isotopic Ratios

    NASA Astrophysics Data System (ADS)

    Friend, A. D.; Babst, F.; Belmecheri, S.; Frank, D. C.; Hacket Pain, A. J.; Hayat, A.; Poulter, B.; Rademacher, T. T.; Trouet, V.

    2015-12-01

    Time series annual of tree ring width, density variation, and oxygen and carbon isotopic compositions have the potential to substantially increase our knowledge of forest responses to environmental variation. However, their interpretation is not straightforward due to the simultaneous influences of a number of confounding factors, including carry-over effects from previous years, variable resource allocation with size, age, and canopy position, species-specific physiologies, and complex interactions between forcings such as temperature, soil moisture, and atmospheric CO2. Here we attempt to tease these factors apart and so substantially improve the interpretability of tree ring archives through the construction and application of novel approaches within a process-based model of individual tree growth. The model incorporates descriptions of xylem cell division, expansion, and secondary wall thickening, apical and lateral meristem activities with internal controls from internal signals, internal carbon storage, and the dynamics of canopy photosynthesis, stomatal movements, evapotranspiration, canopy temperatures, and soil moisture. Alternative treatments of isotopic fractionation and growth controls are evaluated using measured datasets. We demonstrate how this new model approach can be used to assess the information contained in tree rings concerning the influence of increasing atmospheric CO2 over the past century on growth and water use efficiency at a range of sites.

  3. Multiple tree-ring chronologies (ring width, δ13C and δ18O) reveal dry and rainy season signals of rainfall in Indonesia

    NASA Astrophysics Data System (ADS)

    Schollaen, Karina; Heinrich, Ingo; Neuwirth, Burkhard; Krusic, Paul J.; D'Arrigo, Rosanne D.; Karyanto, Oka; Helle, Gerhard

    2013-08-01

    Climatic hazards, such as severe droughts and floods, affect extensive areas across monsoon Asia and can have profound impacts on the populations of that region. The area surrounding Indonesia, including large portions of the eastern Indian Ocean and Java Sea, plays a key role in the global climate system because of the enormous heat and moisture exchange that occurs between the ocean and atmosphere there. Here, we evaluate the influence of rainfall variability on multiple tree-ring parameters of teak (Tectona grandis) trees growing in a lowland rain forest in Central Java (Indonesia). We assess the potential of, annually resolved, tree-ring width, stable carbon (δ13C) and oxygen (δ18O) isotope records to improve our understanding of the Asian monsoon variability. Climate response analysis with regional, monthly rainfall data reveals that all three tree-ring parameters are significantly correlated to rainfall, albeit during different monsoon seasons. Precipitation in the beginning of the rainy season (Sep-Nov) is important for tree-ring width, confirming previous studies. Compared to ring width, the stable isotope records possess a higher degree of common signal, especially during portions of the peak rainy season (δ13C: Dec-May; δ18O: Nov-Feb) and are negatively correlated to rainfall. In addition, tree-ring δ18O also responds positively to peak dry season rainfall, although the δ18O rainy season signal is stronger and more time-stable. The correlations of opposite sign reflect the distinct seasonal contrast of the δ18O signatures in rainfall (18OPre) during the dry (18O-enriched rain) and rainy (18O-depleted rain) seasons. This difference in 18OPre signal reflects the combination of two signals in the annual tree-ring δ18O record. Highly resolved intra-annual δ18O isotope analyses suggest that the signals of dry and rainy season can be distinguished clearly. Thereby reconstructions can improve our understanding of variations and trends of the

  4. Long-term summer sunshine/moisture stress reconstruction from tree-ring widths from Bosnia and Herzegovina

    NASA Astrophysics Data System (ADS)

    Poljanšek, S.; Ceglar, A.; Levanič, T.

    2013-01-01

    We present the first summer sunshine reconstruction from tree-ring data for the western part of the Balkan Peninsula. Summer sunshine is tightly connected with moisture stress in trees, because the moisture stress and therefore the width of annual tree-rings is under the influence of the direct and interactive effects of sunshine duration (temperature, precipitation, cloud cover and evapotranspiration). The reconstruction is based on a calibrated z-scored mean chronology, calculated from tree-ring width measurements from 7 representative black pine (Pinus nigra Arnold) sites in Bosnia and Herzegovina (BiH). A combined regression and scaling approach was used for the reconstruction of the summer sunshine. We found a significant negative correlation (r = -0.54, p < 0.0001) with mean June-July sunshine hours from Osijek meteorological station (Croatia). The developed model was used for reconstruction of summer sunshine for the time period 1660-2010. We identified extreme summer events and compared them to available documentary historical sources of drought, volcanic eruptions and other reconstructions from the broader region. All extreme summers with low sunshine hours (1712, 1810, 1815, 1843, 1899 and 1966) are connected with volcanic eruptions.

  5. Multiple tree-ring chronologies (ring width, δ13C and δ18O) reveal dry and rainy season signals in Indonesia

    NASA Astrophysics Data System (ADS)

    Schollaen, Karina; Heinrich, Ingo; Neuwirth, Burkhard; Krusic, Paul; D`Arrigo, Rosanne; Karyanto, Oka; Helle, Gerhard

    2013-04-01

    The tropical Indonesian region plays a key role in the global climate system because of the enormous heat and moisture exchange between ocean and atmosphere in that area. Here, we evaluate the influence of rainfall variability on multiple tree-ring parameters of Teak (Tectona grandis) trees growing in a lowland rain forest in Central Java (Indonesia). Three, annually resolved, chronologies of tree-ring width, stable carbon (δ13C) and oxygen (δ18O) isotopes were developed for the twentieth century (1900-2007). Climate response analysis with regional rainfall data has revealed that all three tree-ring parameters are significantly sensitive to rainfall during different intervals of the seasonal monsoon pattern. The amount of rainfall at the beginning of the rainy season (Sep-Nov) is important for tree-ring width, confirming previous studies. The stable isotope records best represent slightly different sub-periods of the prime rainy season (δ13C: Dec-May; δ18O: Nov-Feb) with negative correlations. Tree-ring δ18O additionally responds well to peak dry season rainfall with positive correlation. The correlations of opposite sign reflect the distinct seasonal contrast of the δ18O signatures of rainfall during the dry (18O-enriched rain) and rainy (18O-depleted rain) seasons in conjunction with changing rainfall amount. Dry season periods with rainfall amounts above average have an exceptionally strong influence on tree-ring δ18O in years with below average rainy season rainfall. In such cases, the dry season signal reduces the signal strength of the prime rainy season in tree-ring δ18O. However, the rainy season signal is still strong and stable over the 20th century. Further, the δ18O record correlates with several ENSO events, supported by spectral analysis which reveals significant peaks on the 2-4 year band. Highly resolved intra-annual δ18O isotope analyses suggest that the signals of dry and rainy season can be distinguished clearly and demonstrate a new

  6. Spring temperatures in the far-western Nepal Himalaya since AD 1640 reconstructed from Picea smithiana tree-ring widths

    NASA Astrophysics Data System (ADS)

    Thapa, Udya Kuwar; Shah, Santosh K.; Gaire, Narayan Prasad; Bhuju, Dinesh Raj

    2015-10-01

    We developed a new, 422-year long tree-ring width chronology (spanning AD 1591-2012) from Picea smithiana (Wall.) Boiss in Khaptad National Park, which is located in the far-western Nepalese Himalaya. Seasonal correlation analysis revealed significant indirect relationship with spring temperature and lead to the reconstruction of March-May average temperature for the past 373 years (AD 1640-2012). The reconstruction was found significant based on validation statistics commonly used in tree-ring based climate reconstruction. Furthermore, it was validated through spatial correlation with gridded temperature data. This temperature reconstruction identified several periods of warming and cooling. The reconstruction did not show the significant pattern of cooling during the Little Ice Age but there were few cold episodes recorded. The spring temperature revealed relationship with different Sea Surface Temperature index over the equatorial Pacific Ocean, which showed linkages with climatic variability in a global scale.

  7. Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Hsu, Yung; Hsu, Chin-Wei; Yang, Ling-Gang; Chow, Chi-Wai; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-02-01

    In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

  8. Compact and broadband circularly polarized ring antenna with wide beam-width for multiple global navigation satellite systems

    NASA Astrophysics Data System (ADS)

    Zhang, Hong-Lin; Hu, Bin-Jie; Zhang, Xiu-Yin

    2012-02-01

    A compact and broadband circularly polarized (CP) annular ring antenna with wide beam-width is proposed for multiple global navigation satellite systems (GNSS) in the L1 band. The annular ring is excited by two modified L-probes with quadrature phase difference. It has a 36.3% 10-dB return loss bandwidth and a 13% 3-dB axial ratio bandwidth, because of the orthogonal L-probes with 90° phase difference. The measured peak gain of the antenna is 3.9 dBic. It can detect the satellites at lower elevation as its half power beam-width (HPBW) is 113° in both the x—z and y—z planes, achieving a cross-polarization level of larger than 25 dB. Noticeably, the antenna achieves 89% size reduction compared with the conventional half wavelength patch antennas. It can be used in hand-held navigation devices of multiple GNSS such as COMPASS, Galileo, GPS and GLONASS.

  9. Tree-ring-width-based PDSI reconstruction for central Inner Mongolia, China over the past 333 years

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Zhang, Xinjia; Song, Huiming; Cai, Qiufang; Li, Qiang; Zhao, Boyang; Liu, Han; Mei, Ruochen

    2016-04-01

    A tree-ring-width chronology was developed from Pinus tabulaeformis aged up to 333 years from central Inner Mongolia, China. The chronology was significantly correlated with the local Palmer Drought Severity Index (PDSI). We therefore reconstructed the first PDSI reconstruction from March to June based on the local tree ring data from 1680 to 2012 AD. The reconstruction explained 40.7 % of the variance (39.7 % after adjusted the degrees of freedom) of the actual PDSI during the calibration period (1951-2012 AD). The reconstructed PDSI series captured the severe drought event of the late 1920s, which occurred extensively in northern China. Running variance analyses indicated that the variability of drought increased sharply after 1960, indicating more drought years, which may imply anthropogenic related global warming effects in the region. In the entire reconstruction, there were five dry periods: 1730-1814 AD, 1849-1869 AD, 1886-1942 AD (including severe drought in late 1920s), 1963-1978 AD and 2004-2007 AD; and five wet periods: 1685-1729 AD, 1815-1848 AD, 1870-1885 AD, 1943-1962 AD and 1979-2003 AD. Conditions turned dry after 2003 AD, and the PDSI from March to June (PDSI36) captured many interannual extreme drought events since then, such as 2005-2008 AD. The reconstruction is comparable to other tree-ring-width-based PDSI series from the neighboring regions, indicating that our reconstruction has good regional representativeness. Significant relationships were found between our PDSI reconstruction and the solar radiation cycle and the sun spot cycle, North Atlantic Oscillation, the El Niño-Southern Oscillation, as well as the Pacific Decadal Oscillation. Power spectral analyses detected 147.0-, 128.2-, 46.5-, 6.5-, 6.3-, 2.6-, 2.2- and 2.0-year quasi-cycles in the reconstructed series.

  10. Dependence of alloying and island composition on terrace width: Growth of Cu on Ag(100)

    NASA Astrophysics Data System (ADS)

    Beichert, Agnes; Zaum, Christopher; Morgenstern, Karina

    2015-07-01

    The growth of Cu on Ag(100) is investigated by low-temperature scanning tunneling microscopy. Exchange diffusion of Cu deposited onto Ag(100) leads to small pure Cu islands and larger islands consisting of a CuAg alloy in room temperature growth. The ratio of the different types of islands depends on terrace widths up to 100 nm. This surprisingly long-range dependence is correlated to the density of the surface alloy. We thus reveal that the exchange diffusion barrier is influenced by terrace widths far beyond quantum size confinement.

  11. Parameterization of tree-ring growth in Siberia

    NASA Astrophysics Data System (ADS)

    Tychkov, Ivan; Popkova, Margarita; Shishov, Vladimir; Vaganov, Eugene

    2016-04-01

    No doubt, climate-tree growth relationship is an one of the useful and interesting subject of studying in dendrochronology. It provides an information of tree growth dependency on climatic environment, but also, gives information about growth conditions and whole tree-ring growth process for long-term periods. New parameterization approach of the Vaganov-Shashkin process-based model (VS-model) is developed to described critical process linking climate variables with tree-ring formation. The approach (co-called VS-Oscilloscope) is presented as a computer software with graphical interface. As most process-based tree-ring models, VS-model's initial purpose is to describe variability of tree-ring radial growth due to variability of climatic factors, but also to determinate principal factors limiting tree-ring growth. The principal factors affecting on the growth rate of cambial cells in the VS-model are temperature, day light and soil moisture. Detailed testing of VS-Oscilloscope was done for semi-arid area of southern Siberia (Khakassian region). Significant correlations between initial tree-ring chronologies and simulated tree-ring growth curves were obtained. Direct natural observations confirm obtained simulation results including unique growth characteristic for semi-arid habitats. New results concerning formation of wide and narrow rings under different climate conditions are considered. By itself the new parameterization approach (VS-oscilloscope) is an useful instrument for better understanding of various processes in tree-ring formation. The work was supported by the Russian Science Foundation (RSF # 14-14-00219).

  12. Enhancement of metastable zone width for solution growth of potassium acid phthalate

    NASA Astrophysics Data System (ADS)

    Srinivasan, K.; Meera, K.; Ramasamy, P.

    1999-09-01

    A new method has been developed in which the addition of a small amount of ethylenediamine tetra acetic acid (EDTA), a well-known chelating agent, enhances the metastable zone width significantly. Also, it has been found that this addition reduces the rate of nucleation and increases the growth rate of the crystal. This method has been employed for solution growth of potassium hydrogen phthalate (KC 8H 5O 4), which is also known as potassium acid phthalate (KAP).

  13. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    PubMed

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines. PMID:16012820

  14. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    SciTech Connect

    Whitesides, R.; Domin, D.; Salomon-Ferrer, R.; Lester Jr., W.A.; Frenklach, M.

    2007-12-01

    Reaction pathways are presented for hydrogen-mediated isomerization of a five and six member carbon ring complex on the zigzag edge of a graphene layer. A new reaction sequence that reverses orientation of the ring complex, or 'flips' it, was identified. Competition between the flip reaction and 'ring separation' was examined. Ring separation is the reverse of the five and six member ring complex formation reaction, previously reported as 'ring collision'. The elementary steps of the pathways were analyzed using density-functional theory (DFT). Rate coefficients were obtained by solution of the energy master equation and classical transition state theory utilizing the DFT energies, frequencies, and geometries. The results indicate that the flip reaction pathway dominates the separation reaction and should be competitive with other pathways important to the graphene zigzag edge growth in high temperature environments.

  15. Detecting long-term growth trends using tree rings: a critical evaluation of methods.

    PubMed

    Peters, Richard L; Groenendijk, Peter; Vlam, Mart; Zuidema, Pieter A

    2015-05-01

    Tree-ring analysis is often used to assess long-term trends in tree growth. A variety of growth-trend detection methods (GDMs) exist to disentangle age/size trends in growth from long-term growth changes. However, these detrending methods strongly differ in approach, with possible implications for their output. Here, we critically evaluate the consistency, sensitivity, reliability and accuracy of four most widely used GDMs: conservative detrending (CD) applies mathematical functions to correct for decreasing ring widths with age; basal area correction (BAC) transforms diameter into basal area growth; regional curve standardization (RCS) detrends individual tree-ring series using average age/size trends; and size class isolation (SCI) calculates growth trends within separate size classes. First, we evaluated whether these GDMs produce consistent results applied to an empirical tree-ring data set of Melia azedarach, a tropical tree species from Thailand. Three GDMs yielded similar results - a growth decline over time - but the widely used CD method did not detect any change. Second, we assessed the sensitivity (probability of correct growth-trend detection), reliability (100% minus probability of detecting false trends) and accuracy (whether the strength of imposed trends is correctly detected) of these GDMs, by applying them to simulated growth trajectories with different imposed trends: no trend, strong trends (-6% and +6% change per decade) and weak trends (-2%, +2%). All methods except CD, showed high sensitivity, reliability and accuracy to detect strong imposed trends. However, these were considerably lower in the weak or no-trend scenarios. BAC showed good sensitivity and accuracy, but low reliability, indicating uncertainty of trend detection using this method. Our study reveals that the choice of GDM influences results of growth-trend studies. We recommend applying multiple methods when analysing trends and encourage performing sensitivity and reliability

  16. Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

    PubMed

    Kerhoulas, Lucy P; Kane, Jeffrey M

    2012-01-01

    Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

  17. A Standardized Precipitation Evapotranspiration Index Reconstruction in the Taihe Mountains Using Tree-Ring Widths for the Last 283 Years.

    PubMed

    Ma, Yongyong; Liu, Yu; Song, Huiming; Sun, Junyan; Lei, Ying; Wang, Yanchao

    2015-01-01

    Tree-ring samples from Chinese Pine (Pinus tabulaeformis Carr.) that were collected in the Taihe Mountains on the western Loess Plateau, China, were used to analyze the effects of climate and drought on radial growth and to reconstruct the mean April-June Standardized Precipitation Evapotranspiration Index (SPEI) during the period 1730-2012 AD. Precipitation positively affected tree growth primarily during wet seasons, while temperature negatively affected tree growth during dry seasons. Tree growth responded positively to SPEI at long time scales most likely because the trees were able to withstand water deficits but lacked a rapid response to drought. The 10-month scale SPEI was chosen for further drought reconstruction. A calibration model for the period 1951-2011 explained 51% of the variance in the modeled SPEI data. Our SPEI reconstruction revealed long-term patterns of drought variability and captured some significant drought events, including the severe drought of 1928-1930 and the clear drying trend since the 1950s which were widespread across northern China. The reconstruction was also consistent with two other reconstructions on the western Loess Plateau at both interannual and decadal scales. The reconstructed SPEI series showed synchronous variations with the drought/wetness indices and spatial correlation analyses indicated that this reconstruction could be representative of large-scale SPEI variability in northern China. Period analysis discovered 128-year, 25-year, 2.62-year, 2.36-year, and 2.04-year cycles in this reconstruction. The time-dependency of the growth response to drought should be considered in further studies of the community dynamics. The SPEI reconstruction improves the sparse network of long-term climate records for an enhanced understanding of climatic variability on the western Loess Plateau, China. PMID:26207621

  18. A Standardized Precipitation Evapotranspiration Index Reconstruction in the Taihe Mountains Using Tree-Ring Widths for the Last 283 Years

    PubMed Central

    Ma, Yongyong; Liu, Yu; Song, Huiming; Sun, Junyan; Lei, Ying; Wang, Yanchao

    2015-01-01

    Tree-ring samples from Chinese Pine (Pinus tabulaeformis Carr.) that were collected in the Taihe Mountains on the western Loess Plateau, China, were used to analyze the effects of climate and drought on radial growth and to reconstruct the mean April-June Standardized Precipitation Evapotranspiration Index (SPEI) during the period 1730–2012 AD. Precipitation positively affected tree growth primarily during wet seasons, while temperature negatively affected tree growth during dry seasons. Tree growth responded positively to SPEI at long time scales most likely because the trees were able to withstand water deficits but lacked a rapid response to drought. The 10-month scale SPEI was chosen for further drought reconstruction. A calibration model for the period 1951–2011 explained 51% of the variance in the modeled SPEI data. Our SPEI reconstruction revealed long-term patterns of drought variability and captured some significant drought events, including the severe drought of 1928–1930 and the clear drying trend since the 1950s which were widespread across northern China. The reconstruction was also consistent with two other reconstructions on the western Loess Plateau at both interannual and decadal scales. The reconstructed SPEI series showed synchronous variations with the drought/wetness indices and spatial correlation analyses indicated that this reconstruction could be representative of large-scale SPEI variability in northern China. Period analysis discovered 128-year, 25-year, 2.62-year, 2.36-year, and 2.04-year cycles in this reconstruction. The time-dependency of the growth response to drought should be considered in further studies of the community dynamics. The SPEI reconstruction improves the sparse network of long-term climate records for an enhanced understanding of climatic variability on the western Loess Plateau, China. PMID:26207621

  19. A 323-year long reconstruction of drought for SW Romania based on black pine ( Pinus Nigra) tree-ring widths

    NASA Astrophysics Data System (ADS)

    Levanič, Tom; Popa, Ionel; Poljanšek, Simon; Nechita, Constantin

    2013-09-01

    Increase in temperature and decrease in precipitation pose a major future challenge for sustainable ecosystem management in Romania. To understand ecosystem response and the wider social consequences of environmental change, we constructed a 396-year long (1615-2010) drought sensitive tree-ring width chronology (TRW) of Pinus nigra var. banatica (Georg. et Ion.) growing on steep slopes and shallow organic soil. We established a statistical relationship between TRW and two meteorological parameters—monthly sum of precipitation (PP) and standardised precipitation index (SPI). PP and SPI correlate significantly with TRW ( r = 0.54 and 0.58) and are stable in time. Rigorous statistical tests, which measure the accuracy and prediction ability of the model, were all significant. SPI was eventually reconstructed back to 1688, with extreme dry and wet years identified using the percentile method. By means of reconstruction, we identified two so far unknown extremely dry years in Romania—1725 and 1782. Those 2 years are almost as dry as 1946, which was known as the "year of great famine." Since no historical documents for these 2 years were available in local archives, we compared the results with those from neighbouring countries and discovered that both years were extremely dry in the wider region (Slovakia, Hungary, Anatolia, Syria, and Turkey). While the 1800-1900 period was relatively mild, with only two moderately extreme years as far as weather is concerned, the 1900-2009 period was highly salient owing to the very high number of wet and dry extremes—five extremely wet and three extremely dry events (one of them in 1946) were identified.

  20. [Tree-ring growth responses of Mongolian oak (Quercus mongolica) to climate change in southern northeast: a case study in Qianshan Mountains].

    PubMed

    Teng, Li; Xing-Yuan, He; Zhen-Ju, Chen

    2014-07-01

    Mongolian oak is one of the most important broad-leaved tree species in forests, Northeast China. Based on the methodology of dendrochronology, the variations of tree ring radial growth of Mongolian oak in Qianshan Mountains, south of Northeast China, were analyzed. Combined with the temperature and precipitation data from meteorological stations since 1951, the relationships between standardized tree ring width chronology and main climatic factors were analyzed. In this region, the precipitation between April and July of the current year had an significant relationship with the tree ring width of Mongolian oak, and was the main factor limiting the radial growth. The extreme maximum temperature of May was also a key factor influencing the tree ring width, which had a significant on the tree ring width of Mongolian oak. The precipitation in April had a significant and stable relationship with the growth of Mongolian oak since the 1950s. The 'divergence problem' was found in the study area, which the sensitivity of tree growth to summer temperature reduced since the 1980s. The tree growth response to temperature showed a seasonal change from summer to spring. PMID:25345030

  1. Downsag calderas, ring faults, caldera sizes, and incremental caldera growth

    NASA Astrophysics Data System (ADS)

    Walker, G. P. L.

    1984-09-01

    According to present concepts, a caldera is a more or less circular volcanic depression larger than a crater which is caused by subsidence. It is commonly considered that the subsided mass consists of a block or blocks encircled by a ring fracture. Caldera collapse is generally correlated with a major explosive eruption. The present investigation is concerned with six features which do not conform well with the favored caldera model. Attention is given to downsagged calderas, the distribution of postcaldera vents in calderas, vent rings, the size of calderas and cauldrons, incremental caldera growth, and caldera-forming events. It is found that no single structural or genetic model applies to all calderas. Thus, the fact of subsidence may be the only common feature. It is pointed out that most known ring dikes occur in Precambrian crust. This may mean that the subsiding piston mechanism operates best where the crust is sufficiently rigid and strong.

  2. Radial growth of an extended spoke in Saturn's B ring

    SciTech Connect

    Eplee, R.E.,JR.; Smith, B.A.

    1985-08-01

    An analysis is reported of the pattern of radial growth of an extended spoke observed in the Voyager 2 low-resolution Saturn ring movie. The feature is atypical in that it orbits Saturn at the corotational rate for 1-1/2 hours after the onset of its formation and then undergoes a 40-min acceleration to sustained Keplerian velocities. A correlation between the dynamical phases and the radial growth modes of the spoke is observed, one that seems consistent with the plasma cloud model of spoke formation and evolution proposed by Goertz and Morfill (1983), taken in the limit of high charge density. 13 references.

  3. Radial growth of an extended spoke in Saturn's B ring

    NASA Technical Reports Server (NTRS)

    Eplee, R. E., Jr.; Smith, B. A.

    1985-01-01

    An analysis is reported of the pattern of radial growth of an extended spoke observed in the Voyager 2 low-resolution Saturn ring 'movie'. The feature is atypical in that it orbits Saturn at the corotational rate for 1-1/2 hours after the onset of its formation and then undergoes a 40-min acceleration to sustained Keplerian velocities. A correlation between the dynamical phases and the radial growth modes of the spoke is observed, one that seems consistent with the plasma cloud model of spoke formation and evolution proposed by Goertz and Morfill (1983), taken in the limit of high charge density.

  4. Do tree ring chronologies have missing rings that distort volcanic cooling signal?: Tree ring records not distorted by missing rings

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-09-01

    Tree ring records are often used as a proxy for past climate. Trees form a new growth ring each year, and ring widths are related to temperature and other conditions at cold sites. Some recent studies have noted that tree ring width chronologies and resulting climate reconstructions do not appear to show the widespread cooling in the past millennium that would be expected following large volcanic eruptions. One hypothesis suggests that regional cooling after a volcanic eruption could be so severe that many trees do not form a ring at all, which leads researchers to misdate the tree ring chronology.

  5. Research of narrow line-width Er3+-doped fiber ring laser with FBG F-P etalon and FBG Sagnac loop

    NASA Astrophysics Data System (ADS)

    Ou, Zhonghua; Dai, Zhiyong; Wu, Bo; Zhang, Lixun; Peng, Zengshou; Liu, Yongzhi

    2008-12-01

    A novel method of narrow line-width Er3+-doped fiber ring laser based on FBG F-P etalon and FBG Sagnac loop is presented in this paper. The all-fiber single frequency and narrow line-width Er3+-doped fiber ring laser has been designed in which two 976 nm laser diodes are used as the pump sources, the high concentration Er3+-doped fiber as the gain medium, the fiber Faraday rotator is adopted to eliminate the spatial hole burning effect, the FBG F-P etalon and FBG Sagnac loop filter can discriminate and select laser longitudinal modes efficiently. The experiment system using 3m long Er3+-doped fibers is presented, when the maximum pump power of two 976nm laser diodes is 146mW, the fiber laser exhibits 16mW threshold and stable single frequency 1550nm laser with the output powers of 45mW is acquired, and the slope efficiency is about 34.6%. The 3dB line-width is less than 9.3 kHz, measured by the delayed selfheterodyne method with 15km single-mode fiber, and no mode hopping is observed. The fiber laser has the advantages of simple structure, high efficiency and high reliability and it has great potential applications in the fields of optical fiber sensing system.

  6. Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential.

    PubMed

    Hafner, Polona; Gričar, Jožica; Skudnik, Mitja; Levanič, Tom

    2015-01-01

    We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970-2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope

  7. Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential

    PubMed Central

    Hafner, Polona; Gričar, Jožica; Skudnik, Mitja; Levanič, Tom

    2015-01-01

    We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970–2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon

  8. Missing Rings, Synchronous Growth, and Ecological Disturbance in a 36-Year Pitch Pine (Pinus rigida) Provenance Study.

    PubMed

    Leland, Caroline; Hom, John; Skowronski, Nicholas; Ledig, F Thomas; Krusic, Paul J; Cook, Edward R; Martin-Benito, Dario; Martin-Fernandez, Javier; Pederson, Neil

    2016-01-01

    Provenance studies are an increasingly important analog for understanding how trees adapted to particular climatic conditions might respond to climate change. Dendrochronological analysis can illuminate differences among trees from different seed sources in terms of absolute annual growth and sensitivity to external growth factors. We analyzed annual radial growth of 567 36-year-old pitch pine (Pinus rigida Mill.) trees from 27 seed sources to evaluate their performance in a New Jersey Pine Barrens provenance experiment. Unexpectedly, missing rings were prevalent in most trees, and some years-1992, 1999, and 2006-had a particularly high frequency of missing rings across the plantation. Trees from local seed sources (<55 km away from the plantation) had a significantly smaller percentage of missing rings from 1980-2009 (mean: 5.0%), relative to northernmost and southernmost sources (mean: 9.3% and 7.9%, respectively). Some years with a high frequency of missing rings coincide with outbreaks of defoliating insects or dry growing season conditions. The propensity for missing rings synchronized annual variations in growth across all trees and might have complicated the detection of potential differences in interannual variability among seed sources. Average ring width was significantly larger in seed sources from both the southernmost and warmest origins compared to the northernmost and coldest seed sources in most years. Local seed sources had the highest average radial growth. Adaptation to local environmental conditions and disturbances might have influenced the higher growth rate found in local seed sources. These findings underscore the need to understand the integrative impact of multiple environmental drivers, such as disturbance agents and climate change, on tree growth, forest dynamics, and the carbon cycle. PMID:27182599

  9. Missing Rings, Synchronous Growth, and Ecological Disturbance in a 36-Year Pitch Pine (Pinus rigida) Provenance Study

    PubMed Central

    Leland, Caroline; Hom, John; Skowronski, Nicholas; Krusic, Paul J.; Cook, Edward R.; Martin-Benito, Dario; Martin-Fernandez, Javier; Pederson, Neil

    2016-01-01

    Provenance studies are an increasingly important analog for understanding how trees adapted to particular climatic conditions might respond to climate change. Dendrochronological analysis can illuminate differences among trees from different seed sources in terms of absolute annual growth and sensitivity to external growth factors. We analyzed annual radial growth of 567 36-year-old pitch pine (Pinus rigida Mill.) trees from 27 seed sources to evaluate their performance in a New Jersey Pine Barrens provenance experiment. Unexpectedly, missing rings were prevalent in most trees, and some years—1992, 1999, and 2006—had a particularly high frequency of missing rings across the plantation. Trees from local seed sources (<55 km away from the plantation) had a significantly smaller percentage of missing rings from 1980–2009 (mean: 5.0%), relative to northernmost and southernmost sources (mean: 9.3% and 7.9%, respectively). Some years with a high frequency of missing rings coincide with outbreaks of defoliating insects or dry growing season conditions. The propensity for missing rings synchronized annual variations in growth across all trees and might have complicated the detection of potential differences in interannual variability among seed sources. Average ring width was significantly larger in seed sources from both the southernmost and warmest origins compared to the northernmost and coldest seed sources in most years. Local seed sources had the highest average radial growth. Adaptation to local environmental conditions and disturbances might have influenced the higher growth rate found in local seed sources. These findings underscore the need to understand the integrative impact of multiple environmental drivers, such as disturbance agents and climate change, on tree growth, forest dynamics, and the carbon cycle. PMID:27182599

  10. Telemetry carrier ring and support

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor)

    1992-01-01

    A telemetry carrier ring for use in a gas turbine engine includes an annular support ring connected to the engine and an annular carrier ring coupled to the support ring, each ring exhibiting different growth characteristics in response to thermal and mechanical loading. The carrier ring is coupled to the support ring by a plurality of circumferentially spaced web members which are relatively thin in an engine radial direction to provide a predetermined degree of radial flexibility. the web members have a circumferential width and straight axial line of action selected to transfer torque and thrust between the support ring and the carrier ring without substantial deflection. The use of the web members with radial flexibility provides compensation between the support ring and the carrier ring since the carrier ring grows at a different rate than the supporting ring.

  11. Tree-ring growth and wood chemistry response to manipulated precipitation variation for two temperate Quercus species

    SciTech Connect

    Wagner, Rebekah J.; Kaye, Margot W.; Abrams, Marc D.; Hanson, Paul J; Martin, Madhavi Z

    2012-01-01

    We examined the relationship among ambient and manipulated precipitation, wood chemistry, and their relationship with radial growth for two oak species in eastern Tennessee. The study took place on the Walker Branch Throughfall Displacement Experiment (TDE) site, located at the Oak Ridge National Laboratory in Oak Ridge, TN. Two dominant species, white oak (Quercus alba) and chestnut oak (Quercus prinus), were selected for study from a 13-year experiment of whole-stand precipitation manipulation (wet, ambient and dry). The relationships between tree-ring width and climate were compared for both species to determine the impact of precipitation manipulations on ring width index. This study used experimental spectroscopy techniques to measure the sensitivity of tree-ring responses to directional changes in precipitation over 13 years, and the results suggest that oaks at this study site are resilient to imposed changes, but sensitive to inter-annual variations in climate. Laser-induced breakdown spectroscopy (LIBS) allowed us to measure nutrient intensities (similar to element concentrations) at 0.5-1.0 mm spacing along the radial growth axis of trees growing in the wet, ambient, and dry treatment sites. A difference in stemwood nutrient levels was observed between the two oak species and among the three treatments. Significant variation in element intensity was observed across treatments for some elements (Ca, K, Mg, Na, N and P) suggesting the potential for long-term impacts on growth under a changing climate regimes for southeastern oaks.

  12. Understanding tree growth in response to moisture variability: Linking 32 years of satellite based soil moisture observations with tree rings

    NASA Astrophysics Data System (ADS)

    Albrecht, Franziska; Dorigo, Wouter; Gruber, Alexander; Wagner, Wolfgang; Kainz, Wolfgang

    2014-05-01

    Climate change induced drought variability impacts global forest ecosystems and forest carbon cycle dynamics. Physiological drought stress might even become an issue in regions generally not considered water-limited. The water balance at the soil surface is essential for forest growth. Soil moisture is a key driver linking precipitation and tree development. Tree ring based analyses are a potential approach to study the driving role of hydrological parameters for tree growth. However, at present two major research gaps are apparent: i) soil moisture records are hardly considered and ii) only a few studies are linking tree ring chronologies and satellite observations. Here we used tree ring chronologies obtained from the International Tree ring Data Bank (ITRDB) and remotely sensed soil moisture observations (ECV_SM) to analyze the moisture-tree growth relationship. The ECV_SM dataset, which is being distributed through ESA's Climate Change Initiative for soil moisture covers the period 1979 to 2010 at a spatial resolution of 0.25°. First analyses were performed for Mongolia, a country characterized by a continental arid climate. We extracted 13 tree ring chronologies suitable for our analysis from the ITRDB. Using monthly satellite based soil moisture observations we confirmed previous studies on the seasonality of soil moisture in Mongolia. Further, we investigated the relationship between tree growth (as reflected by tree ring width index) and remotely sensed soil moisture records by applying correlation analysis. In terms of correlation coefficient a strong response of tree growth to soil moisture conditions of current April to August was observed, confirming a strong linkage between tree growth and soil water storage. The highest correlation was found for current April (R=0.44), indicating that sufficient water supply is vital for trees at the beginning of the growing season. To verify these results, we related the chronologies to reanalysis precipitation and

  13. Early summer temperature reconstruction in the eastern Tibetan plateau since ad 1440 using tree-ring width of Sabina tibetica

    NASA Astrophysics Data System (ADS)

    Zhu, Hai-Feng; Shao, Xue-Mei; Yin, Zhi-Yong; Huang, Lei

    2011-11-01

    Long climate records are scarce on the Tibetan Plateau for understanding the climate variability on long-term context. Here we presented an early summer (May-June) temperature reconstruction since ad 1440 for Qamdo area using tree rings of Sabina tibetica. The reconstruction accounted for 64% of the variance in the instrumental record. It showed warm periods during 1501-1514, 1528-1538, 1598-1609, 1624-1636, 1650-1668, 1695-1705, 1752-1762, 1794-1804, 1878-1890, 1909-1921, 1938-1949, and 1979-1991. Cool early summer occurred during 1440-1454, 1482-1500, 1515-1527, 1576-1597, 1610-1621, 1669-1679, 1706-1716, 1782-1793, 1863-1873, 1894-1908, and 1922-1937. Comparison with other proxy or meteorological records suggested that there is obvious spatial variability in the May-June temperature variations along the eastern margin of the Tibetan Plateau.

  14. Initial reconstruction of the climate in the last millennium in the central Kola Peninsula (north-western Russia) based on tree-ring widths and stable isotope data of pine (PINUS SYLVESTRIS L.)

    NASA Astrophysics Data System (ADS)

    Boettger, T.; Kononov, Yu.; Friedrich, M.; Kremenetski, C.

    2003-04-01

    More than 300 samples of living tree cores and subfossil slices of Pinus sylvestris L. have been taken in the course of joint field investigations in the Khibiny low mountains in the central part of the Kola Peninsula (approx. 67-68^oN, 33-34^oE). The samples collected enabled a continuous chronological series 1139 years long to be constructed from AD 2000 to 862. It is currently the longest chronological sequence in the region. Comparison between annual ring width and instrumental climatic records over the period 1923-2000 revealed close correlation between the index of annual wood growth and the summer air temperature. In addition, 10 samples of cores taken from living trees were studied by annual isotope analysis (^δ13C and δ18O) of the wood cellulose of their tree rings. Analysis of annual isotope variations in tree ring series are most promising for climatic reconstructions. A significant relationship was established between the proportion of ^δ13C isotope and the mean summer temperature. This formed the basis for reconstructions of the main warming and cooling periods over the period under consideration. Altogether there were 12 significant cooling periods, each about 10-20 years long. As for warmings, they were fewer in number (7) but lasted longer (about 40-90 years). Very strong coolings occurred twice. The first one was from the beginning of the interval studied until AD 884. In all probability, this actually represented the termination of the previous, even colder period, when the weather prevented any tree growth. The second cooling was in 1641-1654, and there is good reason for believing that this was a local manifestation of the Little Ice Age. The mean summer temperature at that time was almost 5^o below that nowadays.

  15. A method to separate temperature and precipitation signals encoded in tree-ring widths for the western Tien Shan Mountains, northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Wenhuo; Gou, Xiaohua; Li, Jinbao; Huo, Yuxia; Fang, Keyan

    2015-10-01

    Separating temperature and precipitation signals encoded in tree rings is a complicated issue. Here, we present a separation method by combining two tree-ring width chronologies of Schrenk's spruce (Picea schrenkiana) from the upper and lower timberlines in the western Tien Shan Mountains, northwest China. Correlation analyses show that both chronologies correlate positively with precipitation. However, temperature correlates positively with the chronology from the upper timberline, while negatively with the chronology from the lower timberline. This suggests that the two chronologies contain similar precipitation information but opposite temperature signals. In light of this, we calculated the average and difference of the two chronologies, and found that each of them has a much stronger correlation with precipitation or temperature alone. Finally, we reconstructed local precipitation and temperature variations over the past 201 years by using the average and difference of the two chronologies. The two reconstructions do not have a significant correlation, but they have significant positive and negative relationships on the high- and low-frequency band, respectively.

  16. Integrating inter- and intra-annual tree-ring width, carbon isotopes and anatomy: responses to climate variability in a temperate oak forest

    NASA Astrophysics Data System (ADS)

    Granda, Elena; Bazot, Stéphane; Fresneau, Chantal; Boura, Anaïs; Faccioni, Georgia; Damesin, Claire

    2015-04-01

    While many forests are experiencing strong tree declines due to climate change in temperate ecosystems, others nearby to those declining show no apparent signs of decline. This could be due to particular microsite conditions or, for instance, to a higher plasticity of given traits that allow a better performance under stressful conditions. We studied oak functional mechanisms (Quercus petraea) leading to the apparently healthy status of the forest and their relation to the observed climatic variability. This study was conducted in the Barbeau Forest (northern France), where cores from mature trees were collected. Three types of functional traits (secondary growth, physiological variables - δ13C and derived Δ13C and iWUE- and several anatomical ones -e.g. vessel area, density-) were recorded for each ring for the 1991-2011 period, distinguishing EW from LW in all measured traits. Among the three types of functional traits, those related to growth experienced the highest variability both between years and between individuals, followed by anatomical and physiological ones. Secondary growth maintained a constant trend during the study period. Instead, ring, EW and LW δ13C slightly declined from 1991 to 2011. Additional intra-ring δ13C analyses allowed for a more detailed understanding of the seasonal dynamics within each year. In particular, the year 2007 (an especially favorable climatic year during the growing season) showed the lowest δ13C values during the EW-LW transition for the whole study period. Inter-annual anatomical traits varied in their responses, but in general, no temporal trends were found. The results from structural equation modeling (SEM) showed direct relationships of seasonal climate and growth, as well as indirect relationships mediated by anatomical and physiological traits. We further discuss the implications of these results on future forest responses to ongoing climate changes.

  17. Graphene Layer Growth: Collision of Migrating Five-MemberRings

    SciTech Connect

    Whitesides, Russell; Kollias, Alexander C.; Domin, Dominik; Lester Jr., William A.; Frenklach, Michael

    2005-12-02

    A reaction pathway is explored in which two cyclopenta groups combine on the zigzag edge of a graphene layer. The process is initiated by H addition to a five-membered ring, followed by opening of that ring and the formation of a six-membered ring adjacent to another five-membered ring. The elementary steps of the migration pathway are analyzed using density functional theory to examine the region of the potential energy surface associated with the pathway. The calculations are performed on a substrate modeled by the zigzag edge of tetracene. Based on the obtained energetics, the dynamics of the system are analyzed by solving the energy transfer master equations. The results indicate energetic and reaction-rate similarity between the cyclopenta combination and migration reactions. Also examined in the present study are desorption rates of migrating cyclopenta rings which are found to be comparable to cyclopenta ring migration.

  18. Ethylene evolution, radial growth and carbohydrate concentrations in Abies balsamea shoots ringed with Ethrel.

    PubMed

    Eklund, Leif; Little, C. H. Anthony

    1998-06-01

    The terminal (1-year-old) shoot of quiescent, 2-year-old Abies balsamea (L.) Mill. seedlings was either left untreated or ringed with 0, 1 or 10 mg Ethrel g(-1) lanolin. After 5 weeks of culture under environmental conditions favorable for growth, the shoots were harvested to measure ethylene evolution and carbohydrate concentrations by gas chromatography, and tracheid number and bark radial width by microscopy. In untreated shoots, the basal rate of ethylene evolution followed the order: cambial region > cortex + periderm = xylem + pith = needles. Wound-induced ethylene production was not detected until at least 4 h after excision, but was evident in all fractions 24 h after excision; the increase in wound-induced ethylene evolution followed the order: cambial region > cortex + periderm > xylem + pith > needles. Compared with untreated controls, the application of plain lanolin, which involved the removal of needles and periderm, increased bark radial width and wound-induced ethylene production by the cambial region and the cortex + periderm, but decreased cambial region concentrations of fructose, glucose and starch at the application point. At the application point, Ethrel concomitantly increased ethylene evolution from the cambial region and the cortex + periderm, tracheid number, bark radial width, and the cambial region concentrations of fructose, glucose, sucrose and starch. No effects of Ethrel treatment were detected above or below the application point, with the exception that the 10 mg g(-1) Ethrel treatment stimulated ethylene evolution and decreased starch concentration of the cambial region. The results indicate that: (1) the cambial region is the major source of endogenous ethylene in the 1-year-old shoot; (2) the magnitude of the difference in ethylene evolution between particular shoot fractions is different before and after the start of wound-induced ethylene production; (3) the Ethrel-induced increase in tracheid number and bark radial width at

  19. Ring chromosome 5 associated with severe growth retardation as the sole major physical abnormality

    SciTech Connect

    Migliori, M.V.; Pettinari, A.; Cherubini, V.; Bartolotta, E.; Pecora, R.

    1994-01-01

    The authors report on a case of ring chromosome 5 in a 36-month-old girl with severe growth retardation, clinodactyly, mild psychological abnormalities, and normal facial appearance. Endocrine tests showed partial growth hormone deficiency. Cytogenetic investigation failed to demonstrate any apparent microscopic deletion of either the short or long arm of chromosome 5 as a consequence of ring formation. In 12% of cells examined, the ring was either absent or present in multiple copies. Only 3 previous cases of ring chromosome 5 have been reported in association with short stature of prenatal onset and minor anomalies, without mental retardation. 12 refs., 3 figs.

  20. The Effects of Variations in Jet Width on the Growth of Baroclinic Waves: Implications for Midwinter Pacific Storm Track Variability.

    NASA Astrophysics Data System (ADS)

    Harnik, Nili; Chang, Edmund K. M.

    2004-01-01

    The effects of variations in jet width on the downstream growth of baroclinic waves are studied, using a simple quasigeostrophic model with a vertically varying basic state and variable channel width, as well as a simplified primitive equation model with a basic state that varies in latitude and height. This study is motivated by observations that in midwinter in the Pacific the storm track is weaker and the jet is narrower during years when the jet is strong.The linear models are able to reproduce the observed decrease of spatial growth rate with shear, if the narrowing of the jet is accounted for by assuming it decreases the meridional wavelength of the perturbations, which hampers their growth. A common suggestion has been that perturbations are weaker when the jet is strong because they move faster out of the unstable storm track region. The authors find that one needs to take into account that the jet narrows when it strengthens; otherwise, the increase of growth rate is strong enough to counteract the effect of increased advection speed.It is also found that, when the model basic state is Eady-like (small or zero meridional potential vorticity gradients in the troposphere), the short-wave cutoff for instability moves to large-scale waves as shear is increased, due to the accompanying increase in meridional wavenumber. This results in a transition from a regime where upper-level perturbations spin up a surface circulation very rapidly, and normal-mode growth ensues, to a regime where the initial perturbations take a very long time to excite growth. Since waves slow down when a surface perturbation develops, this can explain the observations that the storm track perturbations are more “upper level” during strong jet years and their group velocities increase faster than linearly with shear.

  1. Sensitivity of tree ring growth to local and large-scale climate variability in a region of Southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Venegas-González, Alejandro; Chagas, Matheus Peres; Anholetto Júnior, Claudio Roberto; Alvares, Clayton Alcarde; Roig, Fidel Alejandro; Tomazello Filho, Mario

    2016-01-01

    We explored the relationship between tree growth in two tropical species and local and large-scale climate variability in Southeastern Brazil. Tree ring width chronologies of Tectona grandis (teak) and Pinus caribaea (Caribbean pine) trees were compared with local (Water Requirement Satisfaction Index—WRSI, Standardized Precipitation Index—SPI, and Palmer Drought Severity Index—PDSI) and large-scale climate indices that analyze the equatorial pacific sea surface temperature (Trans-Niño Index-TNI and Niño-3.4-N3.4) and atmospheric circulation variations in the Southern Hemisphere (Antarctic Oscillation-AAO). Teak trees showed positive correlation with three indices in the current summer and fall. A significant correlation between WRSI index and Caribbean pine was observed in the dry season preceding tree ring formation. The influence of large-scale climate patterns was observed only for TNI and AAO, where there was a radial growth reduction in months preceding the growing season with positive values of the TNI in teak trees and radial growth increase (decrease) during December (March) to February (May) of the previous (current) growing season with positive phase of the AAO in teak (Caribbean pine) trees. The development of a new dendroclimatological study in Southeastern Brazil sheds light to local and large-scale climate influence on tree growth in recent decades, contributing in future climate change studies.

  2. The influence of summertime fog and overcast clouds on the growth of a coastal Californian pine: a tree-ring study.

    PubMed

    Williams, A Park; Still, Christopher J; Fischer, Douglas T; Leavitt, Steven W

    2008-06-01

    The coast of California is home to numerous rare, endemic conifers and other plants that are limited in distribution by drought sensitivity and the summer-dry climate that prevails across most of the state. Ecologists have long assumed that some coastal plant populations survived the early Pleistocene transition to a warmer and drier environment because they benefit from frequent fog and stratus clouds that provide water and shade during the rainless summer. One such population is that of Torrey pine (Pinus torreyana ssp. Insularis) on Santa Rosa Island in Channel Islands National Park. Here we report that the tree-ring width record from this population indicates strong growth sensitivities to summer fog drip and cloud shading. We quantified the effects of summer cloud cover by comparing ring-width indices to coastal airport cloud-frequency records (1944-2004). For the first time observed, summertime cloud frequency correlated positively with ring-width indices, regardless of whether the effect of rainfall was first removed from the ring-width record. The effect of ground-level fog was strongest in July early mornings (03:00 PST, R(2) = 0.262, P < 0.0002). The effect of clouds high enough to provide shade but not fog water was also strongest in July, but climbed steadily throughout the day before becoming strongest in late afternoon (16:00-18:00 PST, R(2) = 0.148, P < 0.004). Correlations were substantially stronger in years with higher soil moisture, suggesting that growth response to summer clouds is strongly affected by pre-summer rainfall. A change in the height and/or timing of coastal cloud formation with climate change would likely affect this and other populations of California's coastal vegetation. PMID:18368424

  3. Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees.

    PubMed

    Pflug, Ellen E; Siegwolf, R; Buchmann, N; Dobbertin, M; Kuster, T M; Günthardt-Goerg, M S; Arend, M

    2015-10-01

    An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses. PMID:26377873

  4. A Picea crassifolia Tree-Ring Width-Based Temperature Reconstruction for the Mt. Dongda Region, Northwest China, and Its Relationship to Large-Scale Climate Forcing

    PubMed Central

    Liu, Yu; Sun, Changfeng; Li, Qiang; Cai, Qiufang

    2016-01-01

    The historical May–October mean temperature since 1831 was reconstructed based on tree-ring width of Qinghai spruce (Picea crassifolia Kom.) collected on Mt. Dongda, North of the Hexi Corridor in Northwest China. The regression model explained 46.6% of the variance of the instrumentally observed temperature. The cold periods in the reconstruction were 1831–1889, 1894–1901, 1908–1934 and 1950–1952, and the warm periods were 1890–1893, 1902–1907, 1935–1949 and 1953–2011. During the instrumental period (1951–2011), an obvious warming trend appeared in the last twenty years. The reconstruction displayed similar patterns to a temperature reconstruction from the east-central Tibetan Plateau at the inter-decadal timescale, indicating that the temperature reconstruction in this study was a reliable proxy for Northwest China. It was also found that the reconstruction series had good consistency with the Northern Hemisphere temperature at a decadal timescale. Multi-taper method spectral analysis detected some low- and high-frequency cycles (2.3–2.4-year, 2.8-year, 3.4–3.6-year, 5.0-year, 9.9-year and 27.0-year). Combining these cycles, the relationship of the low-frequency change with the Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO) and Southern Oscillation (SO) suggested that the reconstructed temperature variations may be related to large-scale atmospheric-oceanic variations. Major volcanic eruptions were partly reflected in the reconstructed temperatures after high-pass filtering; these events promoted anomalous cooling in this region. The results of this study not only provide new information for assessing the long-term temperature changes in the Hexi Corridor of Northwest China, but also further demonstrate the effects of large-scale atmospheric-oceanic circulation on climate change in Northwest China. PMID:27509206

  5. A Picea crassifolia Tree-Ring Width-Based Temperature Reconstruction for the Mt. Dongda Region, Northwest China, and Its Relationship to Large-Scale Climate Forcing.

    PubMed

    Liu, Yu; Sun, Changfeng; Li, Qiang; Cai, Qiufang

    2016-01-01

    The historical May-October mean temperature since 1831 was reconstructed based on tree-ring width of Qinghai spruce (Picea crassifolia Kom.) collected on Mt. Dongda, North of the Hexi Corridor in Northwest China. The regression model explained 46.6% of the variance of the instrumentally observed temperature. The cold periods in the reconstruction were 1831-1889, 1894-1901, 1908-1934 and 1950-1952, and the warm periods were 1890-1893, 1902-1907, 1935-1949 and 1953-2011. During the instrumental period (1951-2011), an obvious warming trend appeared in the last twenty years. The reconstruction displayed similar patterns to a temperature reconstruction from the east-central Tibetan Plateau at the inter-decadal timescale, indicating that the temperature reconstruction in this study was a reliable proxy for Northwest China. It was also found that the reconstruction series had good consistency with the Northern Hemisphere temperature at a decadal timescale. Multi-taper method spectral analysis detected some low- and high-frequency cycles (2.3-2.4-year, 2.8-year, 3.4-3.6-year, 5.0-year, 9.9-year and 27.0-year). Combining these cycles, the relationship of the low-frequency change with the Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO) and Southern Oscillation (SO) suggested that the reconstructed temperature variations may be related to large-scale atmospheric-oceanic variations. Major volcanic eruptions were partly reflected in the reconstructed temperatures after high-pass filtering; these events promoted anomalous cooling in this region. The results of this study not only provide new information for assessing the long-term temperature changes in the Hexi Corridor of Northwest China, but also further demonstrate the effects of large-scale atmospheric-oceanic circulation on climate change in Northwest China. PMID:27509206

  6. The suitability of annual tree growth rings as environmental archives: Evidence from Sr, Nd, Pb and Ca isotopes in spruce growth rings from the Strengbach watershed

    NASA Astrophysics Data System (ADS)

    Stille, Peter; Schmitt, Anne-Désirée; Labolle, François; Pierret, Marie-Claire; Gangloff, Sophie; Cobert, Florian; Lucot, Eric; Guéguen, Florence; Brioschi, Laure; Steinmann, Marc; Chabaux, François

    2012-05-01

    The combination of the Sr, Nd and Pb isotope systems, recognized as tracers of sources, with the Ca isotope system, known to reveal biology-related fractionations, allowed us to test the reliability of spruce (Picea abies) growth rings as environmental archives through time (from 1916 to 1983) in a forest ecosystem affected by acid atmospheric deposition. Sr and Pb isotopes have already been applied in former tree-ring studies, whereas the suitability of Nd and Ca isotope systems is checked in the present article. Our Sr and Nd isotope data indicate an evolution in the cation origin with a geogenic origin for the oldest rings and an atmospheric origin for the youngest rings. Ca isotopes show, for their part, an isotopic homogeneity which could be linked to the very low weathering flux of Ca. Since this flux is weak the spruces' root systems have pumped the Ca mainly from the organic matter-rich top-soil over the past century. In contrast, the annual growth rings studied are not reliable and suitable archives of past Pb pollution.

  7. Rings

    SciTech Connect

    Davis, R.L.

    1989-01-01

    The essence of vortex physics is that at certain low-energy scales elementary excitations of a point particle theory can behave like strings rather than particles. Vortices are the resulting string-like solutions; their thickness sets the distance scale beyond which physics is string-like rather than particle-like. String degrees of freedom are massless in the sense that excitations on a string can have an arbitrarily low frequency. Non-string degrees of freedom correspond to massive particles and are absent from the low energy spectrum. This article considers only field theories with vortices at low energies. The possible existence of a class of solitons in these vortex theories will be discussed. They are vortex rings: they are localized and finite in energy, and able to carry the quantum numbers of point particles. Rings are thus particle-like solutions of a vortex theory, which is itself a limit of a point particle field theory.

  8. Radiocarbon evidence for annual growth rings in a deep sea octocoral (Primnoa resedaeformis)

    SciTech Connect

    Sherwood, O A; Scott, D B; Risk, M J; Guilderson, T P

    2005-04-05

    The deep-sea gorgonian octocoral Primnoa resedaeformis is distributed throughout the Atlantic and Pacific Oceans at depths of 65-3200 m. It has a two-part skeleton of calcite and gorgonin. Towards the inside of the axial skeleton gorgonin and calcite are deposited in concentric growth rings, similar to tree rings. Colonies were collected from the Northeast Channel (northwest Atlantic Ocean, southwest of Nova Scotia, Canada) from depths of 250-475 m. Radiocarbon was measured in individual rings isolated from sections of each colony, after dissolution of calcite. Each {Delta}{sup 14}C measurement was paired with a ring age determined by three amateur ring counters. The precision of ring counts averaged better than {+-} 2 years. Accurate reconstruction of 20th century bomb-radiocarbon shows that (1) the growth rings are formed annually, (2) the gorgonin is derived from surface particulate organic matter (POM) and (3) useful environmental data are recorded in the organic endoskeletons of deep-sea octocorals. These results support the use of Primnoa resedaeformis as a long-term, high resolution monitor of surface ocean conditions, particularly in temperate and boreal environments where proxy data are lacking.

  9. Double hexagonal graphene ring synthesized using a growth-etching method.

    PubMed

    Liu, Jinyang; Xu, Yangyang; Cai, Hongbing; Zuo, Chuandong; Huang, Zhigao; Lin, Limei; Guo, Xiaomin; Chen, Zhendong; Lai, Fachun

    2016-08-01

    Precisely controlling the layer number, stacking order, edge configuration, shape and structure of graphene is extremely challenging but highly desirable in scientific research. In this report, a new concept named the growth-etching method has been explored to synthesize a graphene ring using the chemical vapor deposition process. The graphene ring is a hexagonal structure, which contains a hexagonal exterior edge and a hexagonal hole in the centre region. The most important concept introduced here is that the oxide nanoparticle derived from annealing is found to play a dual role. Firstly, it acts as a nucleation site to grow the hexagonal graphene domain and then it works as a defect for etching to form a hole. The evolution process of the graphene ring with the etching time was carefully studied. In addition, a double hexagonal graphene ring was successfully synthesized for the first time by repeating the growth-etching process, which not only confirms the validity and repeatability of the method developed here but may also be further extended to grow unique graphene nanostructures with three, four, or even tens of graphene rings. Finally, a schematic model was drawn to illustrate how the double hexagonal graphene ring is generated and propagated. The results shown here may provide valuable guidance for the design and growth of unique nanostructures of graphene and other two-dimensional materials. PMID:27387556

  10. Double hexagonal graphene ring synthesized using a growth-etching method

    NASA Astrophysics Data System (ADS)

    Liu, Jinyang; Xu, Yangyang; Cai, Hongbing; Zuo, Chuandong; Huang, Zhigao; Lin, Limei; Guo, Xiaomin; Chen, Zhendong; Lai, Fachun

    2016-07-01

    Precisely controlling the layer number, stacking order, edge configuration, shape and structure of graphene is extremely challenging but highly desirable in scientific research. In this report, a new concept named the growth-etching method has been explored to synthesize a graphene ring using the chemical vapor deposition process. The graphene ring is a hexagonal structure, which contains a hexagonal exterior edge and a hexagonal hole in the centre region. The most important concept introduced here is that the oxide nanoparticle derived from annealing is found to play a dual role. Firstly, it acts as a nucleation site to grow the hexagonal graphene domain and then it works as a defect for etching to form a hole. The evolution process of the graphene ring with the etching time was carefully studied. In addition, a double hexagonal graphene ring was successfully synthesized for the first time by repeating the growth-etching process, which not only confirms the validity and repeatability of the method developed here but may also be further extended to grow unique graphene nanostructures with three, four, or even tens of graphene rings. Finally, a schematic model was drawn to illustrate how the double hexagonal graphene ring is generated and propagated. The results shown here may provide valuable guidance for the design and growth of unique nanostructures of graphene and other two-dimensional materials.

  11. DYNAMIC STANDARDIZATION OF TREE-RING SERIES

    EPA Science Inventory

    The compound growth function of Warren (W.G. Warren, 1980. ree-Ring Bull. 40:35-44) represented an attempt to develop a model-based approach that standardized tree ring width sequences and was more flexible than the monotonic functions that were then commonly used. hile the idea ...

  12. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    SciTech Connect

    Whitesides, Russell; Domin, Dominik; Lester Jr., William A.; Frenklach, Michael

    2007-03-24

    A theoretical study revealed a new reaction pathway, in which a fused five and six-membered ring complex on the zigzag edge of a graphene layer isomerizes to reverse its orientation, or 'flips,' after activation by a gaseous hydrogen atom. The process is initiated by hydrogen addition to or abstraction from the surface complex. The elementary steps of the migration pathway were analyzed using density-functional theory (DFT) calculations to examine the region of the potential energy surface associated with the pathway. The DFT calculations were performed on substrates modeled by the zigzag edges of tetracene and pentacene. Rate constants for the flip reaction were obtained by the solution of energy master equation utilizing the DFT energies, frequencies, and geometries. The results indicate that this reaction pathway is competitive with other pathways important to the edge evolution of aromatic species in high temperature environments.

  13. Mosaic ring chromosome 14 and monosomy 14 presenting with growth retardation, epilepsy, and blepharophimosis.

    PubMed

    Hou, Jia-Woei

    2004-05-01

    Ring chromosomes are rare chromosomal anomalies and usually not stable in nature. Patients carrying ring chromosome have various phenotypes depending on the degree of structural rearrangement. A 1-year-old boy, presenting with hypotonia, blepharophimosis, ptosis, a bulbous nose, mild psychomotor retardation, and epilepsy, was found to have mosaicism of chromosome ring 14 and monosomy 14. His karyotype is described as hitherto unreported mos 46, XY, r(14)(p11.2q32.31 or q32.2)[84]/45, XY,-14[10]/46, XY, dic r(14)[6]. His seizures responded well to phenobarbital. He has marked growth retardation but less serious delays in mental and motor development than those with ring 14 described in the literature. PMID:15366814

  14. Age trends in tree ring growth and isotopic archives: A case study of Pinus sylvestris L. from northwestern Norway

    NASA Astrophysics Data System (ADS)

    Young, Giles H. F.; Demmler, Joanne C.; Gunnarson, BjöRn E.; Kirchhefer, Andreas J.; Loader, Neil J.; McCarroll, Danny

    2011-06-01

    Measurements of tree ring width and relative density have contributed significantly to many of the large-scale reconstructions of past climatic change, but to extract the climate signal it is first necessary to remove any nonclimatic age-related trends. This detrending can limit the lower-frequency climate information that may be extracted from the archive (the "segment length curse"). This paper uses a data set of ring widths, maximum latewood density and stable carbon and oxygen isotopes from 28 annually resolved series of known-age Pinus sylvestris L. trees in northwestern Norway to test whether stable isotopes in tree rings require an equivalent statistical detrending. Results indicate that stable oxygen and carbon isotope ratios from tree rings whose cambial age exceeds c.50 years exhibit no significant age trends and thus may be used to reconstruct environmental variability and physiological processes at this site without the potential loss of low-frequency information associated with detrending.

  15. Capturing spiral radial growth of conifers using the superellipse to model tree-ring geometric shape

    PubMed Central

    Shi, Pei-Jian; Huang, Jian-Guo; Hui, Cang; Grissino-Mayer, Henri D.; Tardif, Jacques C.; Zhai, Li-Hong; Wang, Fu-Sheng; Li, Bai-Lian

    2015-01-01

    Tree-rings are often assumed to approximate a circular shape when estimating forest productivity and carbon dynamics. However, tree rings are rarely, if ever, circular, thereby possibly resulting in under- or over-estimation in forest productivity and carbon sequestration. Given the crucial role played by tree ring data in assessing forest productivity and carbon storage within a context of global change, it is particularly important that mathematical models adequately render cross-sectional area increment derived from tree rings. We modeled the geometric shape of tree rings using the superellipse equation and checked its validation based on the theoretical simulation and six actual cross sections collected from three conifers. We found that the superellipse better describes the geometric shape of tree rings than the circle commonly used. We showed that a spiral growth trend exists on the radial section over time, which might be closely related to spiral grain along the longitudinal axis. The superellipse generally had higher accuracy than the circle in predicting the basal area increment, resulting in an improved estimate for the basal area. The superellipse may allow better assessing forest productivity and carbon storage in terrestrial forest ecosystems. PMID:26528316

  16. Engelmann spruce tree-ring chronologies from Fraser Experimental Forest, Colorado: Potential for a long-term temperature reconstruction in the central Rocky Mountains

    SciTech Connect

    Brown, P.M.; Shepperd, W.D.

    1995-12-31

    Tree-ring width chronologies from Engelmann spruce at two treeline sites in the central Rocky Mountains contain similar high and low frequency patterns in ring width, indicative of regional climate control on tree growth. Comparisons of annual ring widths with instrumental climate data show relationships with late spring temperature fluctuations on annual to century time scales. Ring width patterns in the earliest dated trees at one of the sites also infers upward migration in treeline at the site around A.D. 1250. No unusual growth increases were seen in recent years, suggesting that these trees have not recorded warmer conditions possibly associated with global climate change.

  17. Effect of plate width on the growth and coalescence of fatigue cracks in plate-to-plate welded T-joints

    SciTech Connect

    Yee, R.; Burns, D.J.; Lambert, S.B.; Lecsek, R.L.; Mohaupt, U.H.

    1995-12-31

    The effect of plate width on the initiation and propagation of fatigue cracks in plate-to-plate T-joints with loading transverse attachment plates and flat fillet-like weld profiles was investigated in a series of constant amplitude fatigue tests. There was no observable effect of plate width on initiation life, propagating life, or total fatigue life, but plate width had a significant effect on crack shape development and crack growth rates. More cracks initiated along the weld toes of wider joints. As a result, the aspect ratios of dominant surface cracks were lower in wider joints, and the dominant surface cracks propagated faster through the thickness of wider base plates. However, there was a greater propensity for edge cracking in narrower specimens because fatigue cracks initiated closer to the free edges of such joints. This offset the faster growth of dominant surface cracks in wider joints so that there was no net effect of plate width on propagation life. A multiple crack linear elastic fracture mechanics model successfully simulated these differences in crack shape development behavior.

  18. An Evaluation of Upper and Lower Pharyngeal Airway Width, Tongue Posture and Hyoid Bone Position in Subjects with Different Growth Patterns

    PubMed Central

    Tarkar, Jaipal Singh; Parashar, Sandeep; Gupta, Garima; Bhardwaj, Preeti; Singh, Atul; Singh, Parul

    2016-01-01

    Introduction It is important to evaluate the position of the hyoid bone in relation to the tongue at the beginning of orthodontic treatment so that during the treatment, its position may be directed hence overall impact on airway could be assessed. Aim The aim of this study was to evaluate the upper and lower pharyngeal airway dimensions, posture of tongue and hyoid bone position in young adults with different growth patterns. Materials and Methods Sample size of the study included 90 post-adolescent subjects, within the age range of 18-32 years. Based on the different growth pattern of the face, subjects were divided into Group I (n=30; average growth pattern), Group II (n=30; horizontal growth pattern) and Group III (n=30; vertical growth pattern). Lateral cephalogram were traced and analysed manually by the same investigator for evaluation of upper and lower pharyngeal airway, tongue posture and hyoid bone position. The intergroup comparison of upper and lower pharyngeal airway dimensions, posture of tongue and hyoid bone was performed with one-way ANOVA test. Results The results showed that upper oropharyngeal widths were significantly different in different facial skeletal patterns (p=0.00). Subjects with vertical skeletal pattern have significantly narrower upper airways than those with horizontal skeletal pattern (p= 0.025). There was significantly higher difference in position of dorsum of the tongue in vertical growth pattern group (p=0.00). The hyoid bone was positioned farther from the mandibular symphysis in brachyfacial subjects, reflected by the larger H-RGN (Hyoid- retrognathion) values compared with the dolichofacial and normal subjects (p=0.044). Conclusion The upper oropharyngeal width was found to be narrower in subjects with vertical growth pattern. The dorsum of the tongue is seen to be placed higher in subjects with vertical growth pattern. The hyoid bone was more inferiorly and posteriorly positioned in subjects with horizontal growth pattern

  19. Reconstructions of spring/summer precipitation for the Eastern Mediterranean from tree-ring widths and its connection to large-scale atmospheric circulation

    NASA Astrophysics Data System (ADS)

    Touchan, Ramzi; Xoplaki, Elena; Funkhouser, Gary; Luterbacher, Jürg; Hughes, Malcolm K.; Erkan, Nesat; Akkemik, Ünal; Stephan, Jean

    2005-07-01

    This study represents the first large-scale systematic dendroclimatic sampling focused on developing chronologies from different species in the eastern Mediterranean region. Six reconstructions were developed from chronologies ranging in length from 115 years to 600 years. The first reconstruction (1885-2000) was derived from principal components (PCs) of 36 combined chronologies. The remaining five, 1800-2000, 1700-2000, 1600-2000, 1500-2000 and 1400-2000 were developed from PCs of 32, 18, 14, 9, and 7 chronologies, respectively. Calibration and verification statistics for the period 1931-2000 show good levels of skill for all reconstructions. The longest period of consecutive dry years, defined as those with less than 90% of the mean of the observed May-August precipitation, was 5 years (1591-1595) and occurred only once during the last 600 years. The longest reconstructed wet period was 5 years (1601-1605 and 1751-1755). No long term trends were found in May-August precipitation during the last few centuries. Regression maps are used to identify the influence of large-scale atmospheric circulation on regional precipitation. In general, tree-ring indices are influenced by May-August precipitation, which is driven by anomalous below (above) normal pressure at all atmospheric levels and by convection (subsidence) and small pressure gradients at sea level. These atmospheric conditions also control the anomaly surface air temperature distribution which indicates below (above) normal values in the southern regions and warmer (cooler) conditions north of around 40°N. A compositing technique is used to extract information on large-scale climate signals from extreme wet and dry summers for the second half of the twentieth century and an independent reconstruction over the last 237 years. Similar main modes of atmospheric patterns and surface air temperature distribution related to extreme dry and wet summers were identified both for the most recent 50 years and the last

  20. February-May temperature reconstruction based on tree-ring widths of Abies fargesii from the Shennongjia area in central China

    NASA Astrophysics Data System (ADS)

    Zheng, Yonghong; Shao, Xuemei; Lu, Fei; Li, Yan

    2016-08-01

    February-May temperature strongly affects ecological processes and socio-economics in central China, yet its long-term variability has not been thoroughly assessed due to the shortness of instrumental records. In order to improve the understanding of the regularities of temperature variability in central China, in this study, we present a new tree-ring chronology from the Shengnongjia Mountains in central China which provides a valuable 245-year record of temperature variability. The reconstructed temperature correlated strongly with February-May mean temperature records of the Fangxian meteorological station from AD 1958 to AD 2011, and the derived reconstruction explained 44.5 % of the instrumental temperature variation during this period. The study shows that this region experienced three warm periods and two cool periods, i.e., the major warm periods occurred in AD 1783-1806, AD 1879-1909, and AD 1975 to the present, whereas the cool intervals occurred in AD 1807-1878 and AD 1910-1974. This reconstruction could aid in the evaluation of regional climate variability in subtropical China.

  1. February-May temperature reconstruction based on tree-ring widths of Abies fargesii from the Shennongjia area in central China

    NASA Astrophysics Data System (ADS)

    Zheng, Yonghong; Shao, Xuemei; Lu, Fei; Li, Yan

    2016-01-01

    February-May temperature strongly affects ecological processes and socio-economics in central China, yet its long-term variability has not been thoroughly assessed due to the shortness of instrumental records. In order to improve the understanding of the regularities of temperature variability in central China, in this study, we present a new tree-ring chronology from the Shengnongjia Mountains in central China which provides a valuable 245-year record of temperature variability. The reconstructed temperature correlated strongly with February-May mean temperature records of the Fangxian meteorological station from AD 1958 to AD 2011, and the derived reconstruction explained 44.5 % of the instrumental temperature variation during this period. The study shows that this region experienced three warm periods and two cool periods, i.e., the major warm periods occurred in AD 1783-1806, AD 1879-1909, and AD 1975 to the present, whereas the cool intervals occurred in AD 1807-1878 and AD 1910-1974. This reconstruction could aid in the evaluation of regional climate variability in subtropical China.

  2. February-May temperature reconstruction based on tree-ring widths of Abies fargesii from the Shennongjia area in central China.

    PubMed

    Zheng, Yonghong; Shao, Xuemei; Lu, Fei; Li, Yan

    2016-08-01

    February-May temperature strongly affects ecological processes and socio-economics in central China, yet its long-term variability has not been thoroughly assessed due to the shortness of instrumental records. In order to improve the understanding of the regularities of temperature variability in central China, in this study, we present a new tree-ring chronology from the Shengnongjia Mountains in central China which provides a valuable 245-year record of temperature variability. The reconstructed temperature correlated strongly with February-May mean temperature records of the Fangxian meteorological station from AD 1958 to AD 2011, and the derived reconstruction explained 44.5 % of the instrumental temperature variation during this period. The study shows that this region experienced three warm periods and two cool periods, i.e., the major warm periods occurred in AD 1783-1806, AD 1879-1909, and AD 1975 to the present, whereas the cool intervals occurred in AD 1807-1878 and AD 1910-1974. This reconstruction could aid in the evaluation of regional climate variability in subtropical China. PMID:26759230

  3. Role of re-growth interface preparation process for spectral line-width reduction of single InAs site-controlled quantum dots.

    PubMed

    Herranz, Jesús; Wewior, Lukasz; Alén, Benito; Fuster, David; González, Luisa; González, Yolanda

    2015-05-15

    We present growth and optical characterization measurements of single InAs site-controlled quantum dots (SCQDs) grown by molecular beam epitaxy on GaAs (001) patterned substrates by atomic force microscopy oxidation lithography. InAs SCQDs directly grown on the patterned surface were used as a seed layer and strain template for the nucleation of optically active single InAs SCQDs. The preservation of the initial geometry of the engraved pattern motifs after the re-growth interface preparation process, the lack of buffer layer growth prior to InAs seed layer deposition and the development of suitable growth conditions provide us an improvement of the SCQDs' active layer optical properties while retaining a high ratio of single occupation (89%). In this work a fivefold reduction of the average optical line-width from 870 μeV to 156 μeV for InAs SCQDs located 15 nm from the re-growth interface is obtained by increasing the temperature of the initial thermal treatment step of the re-growth interface from 490 °C to 530 °C. PMID:25895541

  4. Long Tree-Ring Chronologies Provide Evidence of Recent Tree Growth Decrease in a Central African Tropical Forest

    PubMed Central

    Battipaglia, Giovanna; Zalloni, Enrica; Castaldi, Simona; Marzaioli, Fabio; Cazzolla- Gatti, Roberto; Lasserre, Bruno; Tognetti, Roberto; Marchetti, Marco; Valentini, Riccardo

    2015-01-01

    It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2. PMID:25806946

  5. Btk29A-mediated tyrosine phosphorylation of armadillo/β-catenin promotes ring canal growth in Drosophila oogenesis.

    PubMed

    Hamada-Kawaguchi, Noriko; Nishida, Yasuyoshi; Yamamoto, Daisuke

    2015-01-01

    Drosophila Btk29A is the ortholog of mammalian Btk, a Tec family nonreceptor tyrosine kinase whose deficit causes X-linked agammaglobulinemia in humans. The Btk29AficP mutation induces multiple abnormalities in oogenesis, including the growth arrest of ring canals, large intercellular bridges that allow the flow of cytoplasm carrying maternal products essential for embryonic development from the nurse cells to the oocyte during oogenesis. In this study, inactivation of Parcas, a negative regulator of Btk29A, was found to promote Btk29A accumulation on ring canals with a concomitant increase in the ring canal diameter, counteracting the Btk29AficP mutation. This mutation markedly reduced the accumulation of phosphotyrosine on ring canals and in the regions of cell-cell contact, where adhesion-supporting proteins such as DE-cadherin and β-catenin ortholog Armadillo (Arm) are located. Our previous in vitro and in vivo analyses revealed that Btk29A directly phosphorylates Arm, leading to its release from DE-cadherin. In the present experiments, immunohistological analysis revealed that phosphorylation at tyrosine 150 (Y150) and Y667 of Arm was diminished in Btk29AficP mutant ring canals. Overexpression of an Arm mutant with unphosphorylatable Y150 inhibited ring canal growth. Thus Btk29A-induced Y150 phosphorylation is necessary for the normal growth of ring canals. We suggest that the dissociation of tyrosine-phosphorylated Arm from DE-cadherin allows dynamic actin to reorganize, leading to ring canal expansion and cell shape changes during the course of oogenesis. PMID:25803041

  6. Responses of tree-ring growth and crop yield to drought indices in the Shanxi province, North China.

    PubMed

    Sun, Junyan; Liu, Yu

    2014-09-01

    In this paper, we analyze the relationships among the tree-ring chronology, meteorological drought (precipitation), agricultural drought (Palmer Drought Severity Index PDSI), hydrological drought (runoff), and agricultural data in the Shanxi province of North China. Correlation analyses indicate that the tree-ring chronology is significantly correlated with all of the drought indices during the main growing season from March to July. Sign test analyses further indicate that the tree-ring chronology shows variation similar to that of the drought indices in both high and low frequencies. Comparisons of the years with narrow tree rings to the severe droughts reflected in all three indices from 1957 to 2008 reveal that the radial growth of the trees in the study region can accurately record the severe drought for which all three indices were in agreement (1972, 1999, 2000, and 2001). Comparisons with the dryness/wetness index indicate that tree-ring growth can properly record the severe droughts in the history. Correlation analyses among agricultural data, tree-ring chronology, and drought indices indicate that the per-unit yield of summer crops is relatively well correlated with the agricultural drought, as indicated by the PDSI. The PDSI is the climatic factor that significantly influences both tree growth and per-unit yield of summer crops in the study region. These results indicate that the PDSI and tree-ring chronology have the potential to be used to monitor and predict the yield of summer crops. Tree-ring chronology is an important tool for drought research and for wider applications in agricultural and hydrological research. PMID:24162181

  7. [Paleoclimate of La Guajira, Colombia; by the growth rings of Capparis odoratissima (Capparidaceae)].

    PubMed

    Ramírez, Jorge Andrés; Ignacio del Valle, Jorge

    2011-09-01

    There is great concern about the effect of climate change in arid and subarid areas of the tropics. Climate change combined with other anthropogenic activities such as deforestation, fires and over-grazing can accelerate their degradation and, consequently, the increases in losses of biological and economic productivity. Climate models, both local and global, predict that rainfall in the arid Peninsula of La Guajira in the Colombian Caribbean would be reduced and temperature would be increased as a result of climate change. However, as there are only suitable climate records since 1972, it is not possible to verify if, indeed, this is happening. To try to verify the hypothesis of reducing rainfall and rising temperatures we developed a growth ring chronology of Capparis odoratissima in the Middle Peninsula of La Guajira with 17 trees and 45 series which attain 48 years back. We use standard dendrochronological methods that showed statistically significant linear relationship with local climatic variables such as air temperature, sea surface temperature (SST), annual precipitation and wind speed; we also reach to successful relationship of the chronology with global climatic variables as the indices SOI and MEI of the ENSO phenomenon. The transfer functions estimated with the time series (1955 and 2003) do not showed statistically significant trends, indicating that during this period of time the annual precipitation or temperatures have not changed. The annual nature of C. odoratissima growth rings, the possibility of cross-dated among the samples of this species, and the high correlation with local and global climatic variables indicate a high potential of this species for dendrochronological studies in this part of the American continent. PMID:22017140

  8. Reconstruction of Pacific salmon abundance from riparian tree-ring growth.

    PubMed

    Drake, D C; Naiman, Robert J

    2007-07-01

    We use relationships between modern Pacific salmon (Oncorhynchus spp.) escapement (migrating adults counted at weirs or dams) and riparian tree-ring growth to reconstruct the abundance of stream-spawning salmon over 150-350 years. After examining nine sites, we produced reconstructions for five mid-order rivers and four salmon species over a large geographic range in the Pacific Northwest: chinook (O. tschwatcha) in the Umpqua River, Oregon, USA; sockeye (O. nerka) in Drinkwater Creek, British Columbia, Canada; pink (O. gorbuscha) in Sashin Creek, southeastern Alaska, USA; chum (O. keta) in Disappearance Creek, southeastern Alaska, USA; and pink and chum in the Kadashan River, southeastern Alaska, USA. We first derived stand-level, non-climatic growth chronologies from riparian trees using standard dendroecology methods and differencing. When the chronologies were compared to 18-55 years of adult salmon escapement we detected positive, significant correlations at five of the nine sites. Regression models relating escapement to tree-ring growth at the five sites were applied to the differenced chronologies to reconstruct salmon abundance. Each reconstruction contains unique patterns characteristic of the site and salmon species. Reconstructions were validated by comparison to local histories (e.g., construction of dams and salmon canneries) and regional fisheries data such as salmon landings and aerial surveys and the Pacific Decadal Oscillation climate index. The reconstructions capture lower-frequency cycles better than extremes and are most useful for determination and comparison of relative abundance, cycles, and the effects of interventions. Reconstructions show lower population cycle maxima in both Umpqua River chinook and Sashin Creek pink salmon in recent decades. The Drinkwater Creek reconstruction suggests that sockeye abundance since the mid-1990s has been 15-25% higher than at any time since 1850, while no long-term deviations from natural cycles are

  9. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

    USGS Publications Warehouse

    Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

    2014-01-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  10. An ecological study on air pollution: Changes in annual ring growth of the Japanese cedar and prevalence of respiratory symptoms in schoolchildren in Japanese rural districts

    SciTech Connect

    Kagamimori, S.; Katoh, T.; Naruse, Y.; Kakiuchi, H.; Matsubara, I.; Kasuya, M.; Kawano, S. )

    1990-06-01

    The effect of air pollution caused by oil-fired electricity-generating stations on the annual ring growth of the Japanese cedar (Cryptomeria japonica, D. Don) and prevalence of respiratory symptoms in schoolchildren were investigated. By retrospective analysis the annual ring growth has been demonstrated to show good agreement with the general trend in air pollution. In addition it was found to be related to the prevalence of respiratory symptoms. The reduction in annual ring growth and increase in the prevalence of respiratory symptoms followed a deterioration in air pollution. Following upgrading of the power station and an improvement in air pollution, the annual ring growth and prevalence of respiratory symptoms showed opposite changes, respectively. Concerning the latter, the prevalence of wheezing and respiratory symptoms associated with school absence in schoolchildren with a positive skin test to house dust extract showed a closer correlation with the annual ring growth when compared with those who had never had a positive skin test.

  11. Increase in platinum group elements in Mexico City as revealed from growth rings of Taxodium mucronatum ten.

    PubMed

    Morton-Bermea, Ofelia; Beramendi-Orosco, Laura; Martínez-Reyes, Ángeles; Hernández-Álvarez, Elizabeth; González-Hernández, Galia

    2016-02-01

    Tree rings may be used as indicators of contamination events providing information on the chronology and the elemental composition of the contamination. In this framework, we report PGEs enrichment in growth rings of Taxodium mucronatum ten for trees growing in the central area of Mexico City as compared to trees growing in a non-urban environment. Concentrations of PGE were determined by ICP-MS analysis on microwave-digested tree rings. The element found in higher concentrations was Pd (1.13-87.98 μg kg(-1)), followed by Rh (0.28-36.81 μg kg(-1)) and Pt (0.106-7.21 μg kg(-1)). The concentration trends of PGEs in the tree-ring sequences from the urban area presented significant correlation values when comparing between trees (r between 0.618 and 0.98, P < 0.025) and between elements within individual trees (r between 0.76 and 0.994, P < 0.01). Furthermore, a clear increase was observed for rings after 1997, with enrichment of up to 60 times the mean concentration found for the sequence from the non-urban area and up to 40 times the mean concentration for the pre-1991 period in the urban trees. These results also demonstrate the feasibility of applying T. mucronatum ten to be used as a bioindicator of the increase in PGE in urban environments. PMID:25903068

  12. Parameterization of a multiagent system for roof edge detection: an application to growth ring detection on fish otoliths

    NASA Astrophysics Data System (ADS)

    Guillaud, Anne; Benzinou, Abdessalam; Troadec, Herve; Rodin, Vincent; Le Bihan, Jean

    2000-03-01

    In this paper we present a method of segmentation using a multiagent system, and an application to fish otolith growth ring detection. The otoliths images are composed of alternative concentric dark and light rings, the number of which increases with the age of the fish. Up to now, the identification of growth rings, for age estimation, is routinely achieved by human readers, but this task is tedious and depends on the reader's subjectivity. The system proposed here is composed of several agents whose individual task is to detect local extremes on a grayscale image. For this aim the agents are provided with sensors on the gray levels of the image. By computing the mean gray level of two sensors placed in front of it, the agent, if it searches for light rings (respectively dark) will decide to turn in the direction of the lighter (respectively darker) sensor. The path of the agents has been tested as a roof edge detector, using the Canny criteria: good detection, good localization, and low multiple response, in order to choose the best parameters ruling the agents behavior, according to the image structures. Tests have been first achieved on synthetic images, and then on otoliths images.

  13. Element concentrations in growth rings of trees near an abandoned wood-preserving plant site at Jackson, Tennessee

    USGS Publications Warehouse

    Yanosky, T.M.; Carmichael, J.K.

    1993-01-01

    Multielement analysis was performed on individual annual rings of trees growing at and near an abandoned wood-preserving plant site in Jackson, Tennessee, that operated from the early 1930's until 1981. Numerous organic compounds associated with the wood-preserving process have been detected in soils, ground water, and surface water within much of the site. Tree-ring investigations were conducted prior to investigations of ground water downgradient from the site to determine if trees preserved an areal and temporal record of contaminant movement into offsite areas. Increment cores were collected from trees on the abandoned plant site, in downgradient areas west and south of the site, and at two locations presumably unaffected by contamination from the site. Multielement analysis by proton-induced X-ray emission was performed on 5 to 15 individual growth rings from each of 34 trees that ranged in age from about 5 to 50 years. Concentrations of 16 elements were evaluated by analyzing average concentrations within the 1987, 1989, and 1990 rings of all trees; analyzing element-concentration trends along entire core radii; and analyzing element correlations between and among trees. Concentrations of some nutrients and trace metals were elevated in the outermost sapwood rings of some trees that grow south and southwest of the most contaminated part of the site; small trees on the main part of the site and larger trees to the west generally contained fewer rings with elevated concentrations, particularly of trace metals. Concentrations of several elements elevated in tree rings also were elevated in water samples collected from the reach of a stream that flows near the southwestern part of the site. Multielement analysis of each ring of a willow growing along the southern boundary of the site detected extremely large concentrations of chromium, nickel, and iron in rings that formed in 1986 and thereafter. Relative increases in the concentrations of these elements also

  14. No evidence for consistent long-term growth stimulation of 13 tropical tree species: results from tree-ring analysis.

    PubMed

    Groenendijk, Peter; van der Sleen, Peter; Vlam, Mart; Bunyavejchewin, Sarayudh; Bongers, Frans; Zuidema, Pieter A

    2015-10-01

    The important role of tropical forests in the global carbon cycle makes it imperative to assess changes in their carbon dynamics for accurate projections of future climate-vegetation feedbacks. Forest monitoring studies conducted over the past decades have found evidence for both increasing and decreasing growth rates of tropical forest trees. The limited duration of these studies restrained analyses to decadal scales, and it is still unclear whether growth changes occurred over longer time scales, as would be expected if CO2 -fertilization stimulated tree growth. Furthermore, studies have so far dealt with changes in biomass gain at forest-stand level, but insights into species-specific growth changes - that ultimately determine community-level responses - are lacking. Here, we analyse species-specific growth changes on a centennial scale, using growth data from tree-ring analysis for 13 tree species (~1300 trees), from three sites distributed across the tropics. We used an established (regional curve standardization) and a new (size-class isolation) growth-trend detection method and explicitly assessed the influence of biases on the trend detection. In addition, we assessed whether aggregated trends were present within and across study sites. We found evidence for decreasing growth rates over time for 8-10 species, whereas increases were noted for two species and one showed no trend. Additionally, we found evidence for weak aggregated growth decreases at the site in Thailand and when analysing all sites simultaneously. The observed growth reductions suggest deteriorating growth conditions, perhaps due to warming. However, other causes cannot be excluded, such as recovery from large-scale disturbances or changing forest dynamics. Our findings contrast growth patterns that would be expected if elevated CO2 would stimulate tree growth. These results suggest that commonly assumed growth increases of tropical forests may not occur, which could lead to erroneous

  15. Population differentiation in tree-ring growth response of white fir (Abies concolor) to climate: Implications for predicting forest responses to climate change

    SciTech Connect

    Jensen, D.B.

    1993-10-01

    Forest succession models and correlative models have predicted 200--650 kilometer shifts in the geographic range of temperate forests and forest species as one response to global climate change. Few studies have investigated whether population differences may effect the response of forest species to climate change. This study examines differences in tree-ring growth, and in the phenotypic plasticity of tree-ring growth in 16-year old white fir, Abies concolor, from ten populations grown in four common gardens in the Sierra Nevada of California. For each population, tree-ring growth was modelled as a function of precipitation and degree-day sums. Tree-ring growth under three scenarios of doubled C0{sub 2} climates was estimated.

  16. Stabilization of actin bundles by a dynamin 1/cortactin ring complex is necessary for growth cone filopodia.

    PubMed

    Yamada, Hiroshi; Abe, Tadashi; Satoh, Ayano; Okazaki, Nana; Tago, Shota; Kobayashi, Kinue; Yoshida, Yumi; Oda, Yoshiya; Watanabe, Masami; Tomizawa, Kazuhito; Matsui, Hideki; Takei, Kohji

    2013-03-01

    Dynamin GTPase, a key molecule in endocytosis, mechanically severs the invaginated membrane upon GTP hydrolysis. Dynamin functions also in regulating actin cytoskeleton, but the mechanisms are yet to be defined. Here we show that dynamin 1, a neuronal isoform of dynamin, and cortactin form ring complexes, which twine around F-actin bundles and stabilize them. By negative-staining EM, dynamin 1-cortactin complexes appeared as "open" or "closed" rings depending on guanine nucleotide conditions. By pyrene actin assembly assay, dynamin 1 stimulated actin assembly in mouse brain cytosol. In vitro incubation of F-actin with both dynamin 1 and cortactin led to the formation of long and thick actin bundles, on which dynamin 1 and cortactin were periodically colocalized in puncta. A depolymerization assay revealed that dynamin 1 and cortactin increased the stability of actin bundles, most prominently in the presence of GTP. In rat cortical neurons and human neuroblastoma cell line, SH-SY5Y, both dynamin 1 and cortactin localized on actin filaments and the bundles at growth cone filopodia as revealed by immunoelectron microscopy. In SH-SY5Y cell, acute inhibition of dynamin 1 by application of dynamin inhibitor led to growth cone collapse. Cortactin knockdown also reduced growth cone filopodia. Together, our results strongly suggest that dynamin 1 and cortactin ring complex mechanically stabilizes F-actin bundles in growth cone filopodia. Thus, the GTPase-dependent mechanochemical enzyme property of dynamin is commonly used both in endocytosis and regulation of F-actin bundles by a dynamin 1-cortactin complex. PMID:23467367

  17. Understanding the growth rate patterns of ion Bernstein instabilities driven by ring-like proton velocity distributions

    NASA Astrophysics Data System (ADS)

    Min, Kyungguk; Liu, Kaijun

    2016-04-01

    Fast magnetosonic waves in Earth's inner magnetosphere, which have as their source ion Bernstein instabilities, are driven by hot proton velocity distributions (fp) with ∂fp(v⊥)/∂v⊥>0. Two typical types of distributions with such features are ring and shell velocity distributions. Both have been used in studies of ion Bernstein instabilities and fast magnetosonic waves, but the differences between instabilities driven by the two types of distributions have not been thoroughly addressed. The present study uses linear kinetic theory to examine and understand these differences. It is found that the growth rate pattern is primarily determined by the cyclotron resonance condition and the structure of the velocity distribution in gyroaveraged velocity space. For ring-driven Bernstein instabilities, as the parallel wave number (k∥) increases, the discrete unstable modes approximately follow the corresponding proton cyclotron harmonic frequencies while they become broader in frequency space. At sufficiently large k∥, the neighboring discrete modes merge into a continuum. In contrast, for shell-driven Bernstein instabilities, the curved geometry of the shell velocity distribution in gyroaveraged velocity space results in a complex alternating pattern of growth and damping rates in frequency and wave number space and confines the unstable Bernstein modes to relatively small k∥. In addition, when k∥ increases, the unstable modes are no longer limited to the proton cyclotron harmonic frequencies. The local growth rate peak near an exact harmonic at small k∥ bifurcates into two local peaks on both sides of the harmonic when k∥ becomes large.

  18. Confined growth of carbon nanoforms in one-dimension by fusion of anthracene rings inside the pores of MCM-41

    NASA Astrophysics Data System (ADS)

    Bosch-Navarro, Concha; Coronado, Eugenio; Martí-Gastaldo, Carlos; Amorós, Pedro

    2014-06-01

    We report a simple two-step procedure that uses anthracene, a cheap polyaromatic hydrocarbon with low melting point, as a molecular precursor to produce carbon nanoforms (CNFs). First, we describe the chemical synthesis of graphite from the fusion of anthracene rings at relatively low temperature (520 °C) followed by cyclodehydrogenation. Next, we extend this protocol to the synthesis of CNFs by confining the molecular precursor in a mesoporous host like MCM-41. The confined environment favors one-dimensional growth of CNFs with sizes controlled by the pores of the mesoporous host.We report a simple two-step procedure that uses anthracene, a cheap polyaromatic hydrocarbon with low melting point, as a molecular precursor to produce carbon nanoforms (CNFs). First, we describe the chemical synthesis of graphite from the fusion of anthracene rings at relatively low temperature (520 °C) followed by cyclodehydrogenation. Next, we extend this protocol to the synthesis of CNFs by confining the molecular precursor in a mesoporous host like MCM-41. The confined environment favors one-dimensional growth of CNFs with sizes controlled by the pores of the mesoporous host. Electronic supplementary information (ESI) available: Synthesis details, SEM and additional HR-TEM images, FT-IR spectra, EDAX microanalysis and pore distribution of loaded MCM41@anth. See DOI: 10.1039/c3nr06669j

  19. Seasonal climate signals from multiple tree ring metrics: A case study of Pinus ponderosa in the upper Columbia River Basin

    NASA Astrophysics Data System (ADS)

    Dannenberg, Matthew P.; Wise, Erika K.

    2016-04-01

    Projected changes in the seasonality of hydroclimatic regimes are likely to have important implications for water resources and terrestrial ecosystems in the U.S. Pacific Northwest. The tree ring record, which has frequently been used to position recent changes in a longer-term context, typically relies on signals embedded in the total ring width of tree rings. Additional climatic inferences at a subannual temporal scale can be made using alternative tree ring metrics such as earlywood and latewood widths and the density of tree ring latewood. Here we examine seasonal precipitation and temperature signals embedded in total ring width, earlywood width, adjusted latewood width, and blue intensity chronologies from a network of six Pinus ponderosa sites in and surrounding the upper Columbia River Basin of the U.S. Pacific Northwest. We also evaluate the potential for combining multiple tree ring metrics together in reconstructions of past cool- and warm-season precipitation. The common signal among all metrics and sites is related to warm-season precipitation. Earlywood and latewood widths differ primarily in their sensitivity to conditions in the year prior to growth. Total and earlywood widths from the lowest elevation sites also reflect cool-season moisture. Effective correlation analyses and composite-plus-scale tests suggest that combining multiple tree ring metrics together may improve reconstructions of warm-season precipitation. For cool-season precipitation, total ring width alone explains more variance than any other individual metric or combination of metrics. The composite-plus-scale tests show that variance-scaled precipitation reconstructions in the upper Columbia River Basin may be asymmetric in their ability to capture extreme events.

  20. [Anatomic characterization of growth-rings in 80 potential tree species for dendrocronological studies in the Central Forest, Perú].

    PubMed

    Beltrán Gutiérrez, Lizandro Adal; Valencia Ramos, Gina Mariela

    2013-09-01

    The knowledge about the existence of annual tree rings in tropical trees, which was already found at the beginning of the last century, was ignored by many scientists for a long time. Wood samples of 80 tree species from seven different sites belonging to Satipo and Chanchamayo provinces in Central Forest, Perú. Wood slices were taken at 1.30 m height, following the Peruvian Technical Norms (NTP) 251-008, COPANT norms 30:1-019 and IAWA (1989). Results showed that 24 of the 80 tree species analyzed showed a potential for dendrocronological studies, 25 had problems for growth-rings analysis, and 31 did not have potential. The problems most frequently found were: barely visible or irregular ring growth, parenchyma bands and multiseriate rays difficult to be identified in rings growth. The "T" Student test showed that the significant variation in vessel and fiber diameters between growth zones (Early-wood and late-wood) of species with potential for dendrocronology, do have a periodic cells production, so is possible to suggest the annual formation of each growth-ring. However, those species without potential to dendrocronology may be influenced by of a lot of factors, such as biotic and abiotic conditions of environment, as well as the genetic aspect of each species. PMID:24027905

  1. Relationship between the growth of the ring current and the interplanetary quantity. [solar wind energy-magnetospheric coupling parameter correlation with substorm AE index

    NASA Technical Reports Server (NTRS)

    Akasofu, S.-I.

    1979-01-01

    Akasofu (1979) has reported that the interplanetary parameter epsilon correlates reasonably well with the magnetospheric substorm index AE; in the first approximation, epsilon represents the solar wind coupled to the magnetosphere. The correlation between the interplanetary parameter, the auroral electrojet index and the ring current index is examined for three magnetic storms. It is shown that when the interplanetary parameter exceeds the amount that can be dissipated by the ionosphere in terms of the Joule heat production, the excess energy is absorbed by the ring current belt, producing an abnormal growth of the ring current index.

  2. Crystal growth mechanisms in miarolitic cavities in the Lake George ring complex and vicinity, Colorado

    USGS Publications Warehouse

    Kile, D.E.; Eberl, D.D.

    1999-01-01

    The Crystal Peak area of the Pikes Peak batholith, near Lake George in central Colorado, is world-renowned for its crystals of amazonite (the blue-green variety of microcline) and smoky quartz. Such crystals, collected from individual miarolitic pegmatites, have a remakably small variation in crystal size within each pegmatite, and the shapes of plots of their crystal size distributions (CSDs) are invariably lognormal or close to lognormal in all cases. These observations are explained by a crystal growth mechanism that was governed initially by surface-controlled kinetics, during which crystals tended to grow larger in proportion to their size, thereby establishing lognormal CSDs. Surface-controlled growth was followed by longer periods of supply controlled growth, during which growth rate was predominantly size-independent, consequently preserving the lognormal shapes of the CSDs and the small size variation. The change from surface- to supply controlled growth kinetics may have resulted from an increasing demand for nutrients that exceeded diffusion limitations of the system. The proposed model for crystal growth in this locality appears to be common in the geologic record, and can be used with other information, such as isotopic data, to deduce physico-chemical conditions during crystal formation.

  3. Environmental Assessment of EL Paso's Upper and Lower Valley Canal Systems Using Tree Ring Analysis

    NASA Astrophysics Data System (ADS)

    Garcia, S.; Espinosa, S.

    2012-12-01

    Dendrochronology, or tree-ring dating, is the science of dating of past environmental events or climatic changes utilizing tree ring growth patterns. The width of the rings of certain species of trees (i.e. Populus fremontii) are dependent on regional precipitation levels or the abundance of local water sources. Therefore thick rings are produced during wet years and, inversely, narrow rings during dry years. This growth can also be affected by, and date, such factors as slope gradient, soil properties, temperature and snow accumulation. The more a tree's rate of growth has been limited by such environmental factors, the more variation in ring to ring growth will be present and the higher probability of dating such factors. Trees showing a lack of ring width variability rings have generally constant environmental or climatic conditions and indicate that no environmental or climatic changes have occurred. Our study will examine the tree ring of the Rio Grande Cottonwood (Populus fremontii), due to its short life span, rapid growth, and wide spread occurrence in our proposed study area. Our study area will encompass sites along the Rio Grande, canals and residential areas in El Paso County. Our first goal will be to investigate the possibility of identifying environmental contaminants stored within various xylem tissue members of the tree rings and ascertaining dates and regional concentrations of heavy metals and therefore identifying possible sources of contamination. The second goal will be to use dendrochronology to identify and date any growth stress or impedance due to the effects of over pumping, canal lining, and flood control methods in the study area.

  4. Emittance growth in heavy ion rings due to effects of space charge and dispersion

    SciTech Connect

    Barnard, J.J., LLNL

    1998-06-03

    We review the derivation of moment equations which include the effects of space charge and dispersion in bends first presented in ref [1]. These equations generalize the familiar envelope equations to include the dispersive effects of bends. We review the application of these equations to the calculation of the change in emittance resulting from a sharp transition from a straight section to a bend section, using an energy conservation constraint. Comparisons of detailed 2D and 3D simulations of intense beams in rings using the WARP code (refs [2,3]) are made with results obtained from the moment equations. We also compare the analysis carried out in ref [1], to more recent analyses, refs [4,5]. We further examine self-consistent distributions of beams in bends and discuss the relevance of these distributions to the moment equation formulation.

  5. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry

    2014-03-01

    Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

  6. On the Breakup of Patterened Nanoscale Copper Rings into Nanoparticles: Competing Instability and Transport Mechanisms

    SciTech Connect

    Fowlkes, Jason Davidson; Wu, Yeuyeng; Rack, P. D.; Diez, Javier A; Kondic, Lou

    2010-01-01

    Nanolithographically patterned copper rings were synthesized, and the self-assembly of the rings into ordered nanoparticle/nanodrop arrays was accomplished via nanosecond pulsed laser heating above the melt threshold. The resultant length scale was correlated to the transport and instability growths that occur during the liquid lifetime of the melted copper rings. For 13-nm-thick rings, a change in the nanoparticle spacing with the ring width is attributed to a transition from a Raleigh-Plateau instability to a thin film instability because of competition between the cumulative transport and instability timescales. To explore the competition between instability mechanisms further, we carried out experiments with 7-nm-thick rings. In agreement with the theoretical predictions, these rings break up in both the azimuthal and radial directions, confirming that a simple hydrodynamic model captures the main features of the processes leading to the breakup.

  7. miR-762 promotes porcine immature Sertoli cell growth via the ring finger protein 4 (RNF4) gene

    PubMed Central

    Ma, Changping; Song, Huibin; Yu, Lei; Guan, Kaifeng; Hu, Pandi; Li, Yang; Xia, Xuanyan; Li, Jialian; Jiang, Siwen; Li, Fenge

    2016-01-01

    A growing number of reports have revealed that microRNAs (miRNAs) play critical roles in spermatogenesis. Our previous study showed that miR-762 is differentially expressed in immature and mature testes of Large White boars. Our present data shows that miR-762 directly binds the 3′ untranslated region (3′UTR) of ring finger protein 4 (RNF4) and down-regulates RNF4 expression. A single nucleotide polymorphism (SNP) in the RNF4 3′UTR that is significantly associated with porcine sperm quality traits leads to a change in the miR-762 binding ability. Moreover, miR-762 promotes the proliferation of and inhibits apoptosis in porcine immature Sertoli cells, partly by accelerating DNA damage repair and by reducing androgen receptor (AR) expression. Taken together, these findings suggest that miR-762 may play a role in pig spermatogenesis by regulating immature Sertoli cell growth. PMID:27596571

  8. miR-762 promotes porcine immature Sertoli cell growth via the ring finger protein 4 (RNF4) gene.

    PubMed

    Ma, Changping; Song, Huibin; Yu, Lei; Guan, Kaifeng; Hu, Pandi; Li, Yang; Xia, Xuanyan; Li, Jialian; Jiang, Siwen; Li, Fenge

    2016-01-01

    A growing number of reports have revealed that microRNAs (miRNAs) play critical roles in spermatogenesis. Our previous study showed that miR-762 is differentially expressed in immature and mature testes of Large White boars. Our present data shows that miR-762 directly binds the 3' untranslated region (3'UTR) of ring finger protein 4 (RNF4) and down-regulates RNF4 expression. A single nucleotide polymorphism (SNP) in the RNF4 3'UTR that is significantly associated with porcine sperm quality traits leads to a change in the miR-762 binding ability. Moreover, miR-762 promotes the proliferation of and inhibits apoptosis in porcine immature Sertoli cells, partly by accelerating DNA damage repair and by reducing androgen receptor (AR) expression. Taken together, these findings suggest that miR-762 may play a role in pig spermatogenesis by regulating immature Sertoli cell growth. PMID:27596571

  9. Growth of ring ripple in a collisionless plasma in relativistic-ponderomotive regime and its effect on stimulated Raman backscattering process

    SciTech Connect

    Rawat, Priyanka; Purohit, Gunjan; Gauniyal, Rakhi

    2014-06-15

    A theoretical and numerical study has been made of the propagation of a ring rippled laser beam in collisionless plasma with dominant relativistic ponderomotive nonlinearity and its effect on the excitation of electron plasma wave and stimulated Raman backscattering process. The growth of ring ripple, riding on an intense Gaussian laser beam in plasma has also been studied. A paraxial-ray and WKB approximation has been invoked to understand the nature of propagation of the ring rippled Gaussian laser beam in plasma, electron plasma wave and back reflectivity under the influence of both nonlinearities. The growth rate and focusing of a ring rippled beam is found to be considerably affected by the power of the main beam and the phase angle between the electric vectors of the main beam and the ring ripple. It has also been observed that the focusing is released by the coupling of relativistic and ponderomotive nonlinearities, which significantly affected the dynamics of the excitation of electron plasma wave and back reflectivity of stimulated Raman scattering (SRS). Due to the strong coupling between ring rippled laser beam and the excited electron plasma wave, back reflectivity of SRS is enhanced. It has been observed from the computational results that the effect of the increased intensity leads to suppression of SRS back reflectivity. The results have been presented for established laser and plasma parameters.

  10. Voyager 2 and the Uranian rings

    SciTech Connect

    Porco, C.C.

    1986-12-01

    Voyager 2 data on the Uranian disk system are presented and examined. The disk system consists of nine narrow rings, ranging in width from a few km to about 100 km. The Uranian rings are eccentric, inclined to the planet's equatorial plane, and precessing. The Uranian ring characteristics detected in the Voyager data are described and compared with those of the Saturn rings. The origin and maintenance of the rings are discussed, and the particle distribution in the ring system is studied.

  11. Plasma deposited rider rings for hot displacer

    DOEpatents

    Kroebig, Helmut L.

    1976-01-01

    A hot cylinder for a cryogenic refrigerator having two plasma spray deposited rider rings of a corrosion and abrasion resistant material provided in the rider ring grooves, wherein the rider rings are machined to the desired diameter and width after deposition. The rider rings have gas flow flats machined on their outer surface.

  12. Tree-ring based history of climate and disease in western Oregon forests

    EPA Science Inventory

    Annual tree-ring width data are often used to make inferences of past climate and the spatiotemporal climate-growth relationships. However, the climatic signal may be confounded with non-climatic signals such as disease or pest disturbances at unknown times in the past. Signal e...

  13. Design and synthesis of benzoylphenylureas with fluorinated substituents on the aniline ring as insect growth regulators.

    PubMed

    Sun, Ranfeng; Liu, Yuxiu; Zhang, Yonglin; Xiong, Lixia; Wang, Qingmin

    2011-03-23

    Enormous numbers of synthetic fluorine-containing compounds have been widely used in a variety of fields, especially in drug and pesticide design. To find novel insect growth regulators, a series of benzoylphenylureas with fluorinated substituents were designed and synthesized. The results of larvicidal activities of those novel fluoro-substituted benzoylphenylureas against oriental armyworm and mosquito revealed that most compounds exhibited excellent activities. It is worth mentioning that compounds 3 and 6 exhibited higher activities against oriental armyworm and mosquito than commercial Hexaflumuron. It can be further seen that the insecticidal activities would increase significantly by introducing fluorinated substituents into the structure of the designed benzoylphenylureas. PMID:21366291

  14. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry W.

    2011-07-01

    Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

  15. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO2 assimilation and growth in Douglas-fir

    EPA Science Inventory

    Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible...

  16. Studies and calculations of transverse emittance growth in high-energy proton storage rings

    SciTech Connect

    Mane, S.R.; Jackson, G.

    1989-03-01

    In the operation of proton-antiproton colliders, an important goal is to maximize the integrated luminosity. During such operations in the Fermilab Tevatron, the transverse beam emittances were observed to grow unexpectedly quickly, thus causing a serious reduction of the luminosity. We have studied this phenomenon experimentally and theoretically. A formula for the emittance growth rate, due to random dipole kicks, is derived. In the experiment, RF phase noise of known amplitude was deliberately injected into the Tevatron to kick the beam randomly, via dispersion at the RF cavities. Theory and experiment are found to agree reasonably well. We also briefly discuss the problem of quadrupole kicks. 14 refs., 2 figs., 3 tabs.

  17. Drosophila E-cadherin is required for the maintenance of ring canals anchoring to mechanically withstand tissue growth

    PubMed Central

    Loyer, Nicolas; Kolotuev, Irina; Pinot, Mathieu; Le Borgne, Roland

    2015-01-01

    Intercellular bridges called “ring canals” (RCs) resulting from incomplete cytokinesis play an essential role in intercellular communication in somatic and germinal tissues. During Drosophila oogenesis, RCs connect the maturing oocyte to nurse cells supporting its growth. Despite numerous genetic screens aimed at identifying genes involved in RC biogenesis and maturation, how RCs anchor to the plasma membrane (PM) throughout development remains unexplained. In this study, we report that the clathrin adaptor protein 1 (AP-1) complex, although dispensable for the biogenesis of RCs, is required for the maintenance of the anchorage of RCs to the PM to withstand the increased membrane tension associated with the exponential tissue growth at the onset of vitellogenesis. Here we unravel the mechanisms by which AP-1 enables the maintenance of RCs’ anchoring to the PM during size expansion. We show that AP-1 regulates the localization of the intercellular adhesion molecule E-cadherin and that loss of AP-1 causes the disappearance of the E-cadherin–containing adhesive clusters surrounding the RCs. E-cadherin itself is shown to be required for the maintenance of the RCs’ anchorage, a function previously unrecognized because of functional compensation by N-cadherin. Scanning block-face EM combined with transmission EM analyses reveals the presence of interdigitated, actin- and Moesin-positive, microvilli-like structures wrapping the RCs. Thus, by modulating E-cadherin trafficking, we show that the sustained E-cadherin–dependent adhesion organizes the microvilli meshwork and ensures the proper attachment of RCs to the PM, thereby counteracting the increasing membrane tension induced by exponential tissue growth. PMID:26424451

  18. Drosophila E-cadherin is required for the maintenance of ring canals anchoring to mechanically withstand tissue growth.

    PubMed

    Loyer, Nicolas; Kolotuev, Irina; Pinot, Mathieu; Le Borgne, Roland

    2015-10-13

    Intercellular bridges called "ring canals" (RCs) resulting from incomplete cytokinesis play an essential role in intercellular communication in somatic and germinal tissues. During Drosophila oogenesis, RCs connect the maturing oocyte to nurse cells supporting its growth. Despite numerous genetic screens aimed at identifying genes involved in RC biogenesis and maturation, how RCs anchor to the plasma membrane (PM) throughout development remains unexplained. In this study, we report that the clathrin adaptor protein 1 (AP-1) complex, although dispensable for the biogenesis of RCs, is required for the maintenance of the anchorage of RCs to the PM to withstand the increased membrane tension associated with the exponential tissue growth at the onset of vitellogenesis. Here we unravel the mechanisms by which AP-1 enables the maintenance of RCs' anchoring to the PM during size expansion. We show that AP-1 regulates the localization of the intercellular adhesion molecule E-cadherin and that loss of AP-1 causes the disappearance of the E-cadherin-containing adhesive clusters surrounding the RCs. E-cadherin itself is shown to be required for the maintenance of the RCs' anchorage, a function previously unrecognized because of functional compensation by N-cadherin. Scanning block-face EM combined with transmission EM analyses reveals the presence of interdigitated, actin- and Moesin-positive, microvilli-like structures wrapping the RCs. Thus, by modulating E-cadherin trafficking, we show that the sustained E-cadherin-dependent adhesion organizes the microvilli meshwork and ensures the proper attachment of RCs to the PM, thereby counteracting the increasing membrane tension induced by exponential tissue growth. PMID:26424451

  19. Resonances and resonance widths

    SciTech Connect

    Collins, T.

    1986-05-01

    Two-dimensional betatron resonances are much more important than their simple one-dimensional counterparts and exhibit a strong dependence on the betatron phase advance per cell. A practical definition of ''width'' is expanded upon in order to display these relations in tables. A primarily pedagogical introduction is given to explain the tables, and also to encourage a wider capability for deriving resonance behavior and wider use of ''designer'' resonances.

  20. Narrow Width Pentaquarks

    NASA Astrophysics Data System (ADS)

    Buccella, F.; Sorba, P.

    A general study of pentaquarks built with four quarks in a L=1 state and an antiquark in S-wave shows that several of such states are forbidden by a selection rule, which holds in the limit of flavor symmetry, to decay into a baryon and a meson final state. We identify the most promising /line{10} multiplet for the classification of the Θ+ and Ξ-- particles recently discovered with the prediction of a narrow width for both of them.

  1. Long range correlations in tree ring chronologies of the USA: Variation within and across species

    NASA Astrophysics Data System (ADS)

    Bowers, M. C.; Gao, J. B.; Tung, W. W.

    2013-02-01

    Abstract Tree <span class="hlt">ring</span> <span class="hlt">width</span> data are among the best proxies for reconstructing past temperature and precipitation records. The discovery of fractal scaling and long-memory in meteorological and hydrological signals motivates us to investigate such properties in tree <span class="hlt">ring</span> chronologies. Detrended fluctuation analysis and adaptive fractal analysis are utilized to estimate the Hurst parameter values of 697 tree <span class="hlt">ring</span> chronologies from the continental United States. We find significant differences in the Hurst parameter values across the 10 species studied in the work. The long-range scaling relations found here suggest that the behavior of tree <span class="hlt">ring</span> <span class="hlt">growth</span> observed in a short calibration period may be similar to the general behavior of tree <span class="hlt">ring</span> <span class="hlt">growth</span> in a much longer period, and therefore, the limited calibration period may be more useful than originally thought. The variations of the long-range correlations within and across species may be further explored in future to better reconstruct paleoclimatic records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1086956','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1086956"><span id="translatedtitle">Effects of Changing Stomatal <span class="hlt">Width</span> in A Red Pine Forest on Soil Water Content, Leaf Water Potential, Bole Diameter, and <span class="hlt">Growth</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Turner, Neil C.; Waggoner, Paul E.</p> <p>1968-01-01</p> <p>Spraying a 16 meter tall stand of red pine (Pinus resinosa Ait.) with 10−3 m phenylmercuric acetate in early June and again in mid-July resulted in the water use between June 1 and October 25 being reduced by almost 10%. It was demonstrated that this was caused by an increase in the leaf resistance with partial stomatal closure, which reduced absolute water potential in the needles by 1 to 3 bars in the middle of the day. Smaller demands were made upon the reserves of water in the bole of the tree as shown by the smaller bole contraction in the treated trees. Although needle length and dry weight were unaffected by the spray, radial <span class="hlt">growth</span> was reduced by approximately 32%. The dependence of leaf resistance on light intensity is shown, and its independence from leaf water potential discussed. PMID:16656870</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730015432','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730015432"><span id="translatedtitle">Diatomic predissociation line <span class="hlt">widths</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Child, M. S.</p> <p>1973-01-01</p> <p>Predissociation by rotation and curve crossing in diatomic molecules is discussed. The pattern of predissociation line <span class="hlt">widths</span> is seen as providing a highly sensitive yardstick for the determination of unknown potential curves. In addition, the computation of such a pattern for given potential curves is considered a matter of routine, unless the predissociation happens to occur from an adiabatic potential curve. Analytic formulas are used to provide physical insight into the details of the predissociation pattern, to the extent that a direct inversion procedure is developed for determination of the repulsive potential curves for Type 1 predissociations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B11C0449K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B11C0449K"><span id="translatedtitle">Model-based analysis on the relationship between production and tree-<span class="hlt">ring</span> <span class="hlt">growth</span> in Japanese conifer-hardwood mixed forests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koide, D.; Ito, A.</p> <p>2015-12-01</p> <p>Forest productivity is a basic and important component of terrestrial material flow and its importance increases according to recent climate warming and the increase in atmospheric-CO2 concentrations. Forest productivity study progresses through measurement by eddy-covariance data from flux tower and prediction by terrestrial ecosystem models. However, flux tower observation has spatiotemporal bias and limitation. On the other hand, tree-<span class="hlt">ring</span> data have a close connection with forest ecosystem productivity. Compared to flux tower observation, we can collect tree-<span class="hlt">ring</span> data from a larger number of sites and longer time scales. Comparisons between tree-<span class="hlt">ring</span> observation and model-estimated productivity is important to reveal underlying mechanisms of forest ecosystem productivity and <span class="hlt">growth</span> in wide spatiotemporal scale. This study aimed at revealing the relationship between temporal changes in tree-<span class="hlt">ring</span> data and estimated forest ecosystem productivity in Japanese conifer-hardwood mixed forest. We also addressed climatic bias in the relationship by comparing between sites at different climatic conditions. Tree-<span class="hlt">ring</span> data of Sakhalin spruce (Picea glehnii) were obtained from the International Tree <span class="hlt">Ring</span> Data Bank. Six sites on the Hokkaido island (northern island of Japan) were selected for the present analysis. The Vegetation Integrated SImulator for Trace gasses (VISIT) model was validated by comparing with carbon flux data from Asia flux network sites. Past climatic parameters were obtained from ERA-20C reanalysis data from the European Center for Medium-range Weather Forecasts. Correlation between basal area increment and net ecosystem productivity was highest in the coldest site but this correlation weakened in warmer sites. This result implies that long-term <span class="hlt">growth</span> trend was mainly restricted by cold stress associated with productivity reduction in colder sites but this factor is less important and other factors exert influence in warmer sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015APS..DFDA33003K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015APS..DFDA33003K&link_type=ABSTRACT"><span id="translatedtitle">Coffee-<span class="hlt">ring</span> effect beyond the dilute limit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Jin Young; Ryu, Seul-A.; Kim, Hyungdae; Kim, Joon Heon; Park, Jung Su; Park, Yong Seok; Oh, Jeong Su; Weon, Byung Mook</p> <p>2015-11-01</p> <p>The coffee-<span class="hlt">ring</span> effect, which is a natural generation of outward capillary flows inside drying coffee drops, is valid at the dilute limit of initial solute concentrations. If the solute is not dilute, the <span class="hlt">ring</span> deposit is forced to have a non-zero <span class="hlt">width</span>; higher initial concentration leads to a wider <span class="hlt">ring</span>. Here we study the coffee-<span class="hlt">ring</span> effect in the dense limit by demonstrating differences with various initial coffee concentrations from 0.1% to 60%. The coffee drops with high initial concentrations of real coffee particles show interesting evaporation dynamics: dense coffee drops tend to evaporate slowly. This result is different from the classic coffee-<span class="hlt">ring</span> effect in the dilute limit. We suppose that the slow evaporation of dense coffee drops is associated with the <span class="hlt">ring</span> <span class="hlt">growth</span> dynamics. The coffee-<span class="hlt">ring</span> effect becomes more significant in modern technologies such as self-assembly of nanoparticles, ink-jet printing, painting and ceramics. The complexity in evaporation dynamics of colloidal fluids would be able to be understood by expanding the coffee-<span class="hlt">ring</span> effects in the dilute as well as the dense limits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011IAUS..271..102W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011IAUS..271..102W"><span id="translatedtitle">On the formation of <span class="hlt">ring</span> galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yu-Ting; Jiang, Ing-Guey</p> <p>2011-08-01</p> <p>The formation scenario of <span class="hlt">ring</span> galaxies is addressed in this paper. We focus on the P-type <span class="hlt">ring</span> galaxies presented in Madore, Nelson & Petrillo (2009), particularly on the axis-symmetric ones. Our simulations show that a <span class="hlt">ring</span> can form through the collision of disc and dwarf galaxies, and the locations, <span class="hlt">widths</span>, and density contrasts of the <span class="hlt">ring</span> are well determined. We find that a <span class="hlt">ring</span> galaxy such as AM 2302-322 can be produced by this collision scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=256514&keyword=Geography&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65002399&CFTOKEN=44109874','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=256514&keyword=Geography&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65002399&CFTOKEN=44109874"><span id="translatedtitle">Statistical methodologies for tree-<span class="hlt">ring</span> research to understand the climate-<span class="hlt">growth</span> relationships over time and space</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The International Tree-<span class="hlt">Ring</span> Database is a valuable resource for studying climate change and its effects on terrestrial ecosystems over time and space. We examine the statistical methods in current use in dendroclimatology and dendroecology to process the tree-<span class="hlt">ring</span> data and make ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/971178','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/971178"><span id="translatedtitle">Wavelength-tunable optical <span class="hlt">ring</span> resonators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.</p> <p>2009-11-10</p> <p>Optical <span class="hlt">ring</span> resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk <span class="hlt">ring</span> resonators, or as open-<span class="hlt">ring</span> resonators with an optical waveguide having a <span class="hlt">width</span> that varies adiabatically. Electrical and mechanical connections to the open-<span class="hlt">ring</span> resonators are made near a maximum <span class="hlt">width</span> of the optical waveguide to minimize losses and thereby provide a high resonator Q. The <span class="hlt">ring</span> resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1021901','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1021901"><span id="translatedtitle">Wavelength-tunable optical <span class="hlt">ring</span> resonators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.</p> <p>2011-07-19</p> <p>Optical <span class="hlt">ring</span> resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk <span class="hlt">ring</span> resonators, or as open-<span class="hlt">ring</span> resonators with an optical waveguide having a <span class="hlt">width</span> that varies adiabatically. Electrical and mechanical connections to the open-<span class="hlt">ring</span> resonators are made near a maximum <span class="hlt">width</span> of the optical waveguide to minimize losses and thereby provide a high resonator Q. The <span class="hlt">ring</span> resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1413742S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413742S"><span id="translatedtitle">iTREE: Long-term variability of tree <span class="hlt">growth</span> in a changing environment - identifying physiological mechanisms using stable C and O isotopes in tree <span class="hlt">rings</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siegwolf, R. T. W.; Buchmann, N.; Frank, D.; Joos, F.; Kahmen, A.; Treydte, K.; Leuenberger, M.; Saurer, M.</p> <p>2012-04-01</p> <p>Trees play are a critical role in the carbon cycle - their photosynthetic assimilation is one of the largest terrestrial carbon fluxes and their standing biomass represents the largest carbon pool of the terrestrial biosphere. Understanding how tree physiology and <span class="hlt">growth</span> respond to long-term environmental change is pivotal to predict the magnitude and direction of the terrestrial carbon sink. iTREE is an interdisciplinary research framework to capitalize on synergies among leading dendroclimatologists, plant physiologists, isotope specialists, and global carbon cycle modelers with the objectives of reducing uncertainties related to tree/forest <span class="hlt">growth</span> in the context of changing natural environments. Cross-cutting themes in our project are tree <span class="hlt">rings</span>, stable isotopes, and mechanistic modelling. We will (i) establish a European network of tree-<span class="hlt">ring</span> based isotope time-series to retrodict interannual to long-term tree physiological changes, (ii) conduct laboratory and field experiments to adapt a mechanistic isotope model to derive plant physiological variables from tree-<span class="hlt">ring</span> isotopes, (iii) implement this model into a dynamic global vegetation model, and perform subsequent model-data validation exercises to refine model representation of plant physiological processes and (iv) attribute long-term variation in tree <span class="hlt">growth</span> to plant physiological and environmental drivers, and identify how our refined knowledge revises predictions of the coupled carbon-cycle climate system. We will contribute to i) advanced quantifications of long-term variation in tree <span class="hlt">growth</span> across Central Europe, ii) novel long-term information on key physiological processes that underlie variations in tree <span class="hlt">growth</span>, and iii) improved carbon cycle models that can be employed to revise predictions of the coupled carbon-cycle climate system. Hence iTREE will significantly contribute towards a seamless understanding of the responses of terrestrial ecosystems to long-term environmental change, and ultimately</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5179339','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5179339"><span id="translatedtitle"><span class="hlt">Width</span> of nonlinear resonance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ohnuma, S.</p> <p>1984-03-01</p> <p>Two approximations are made, one essential and the other not so essential but convenient to keep the analytical treatment manageable: (1) Only one nonlinear resonance is considered at a time so that the treatment is best suited when the tune is close to one resonance only. To improve this approximation, one must go to the next order which involves a canonical transformation of dynamical variables. Analytical treatment of more than one resonance is not possible for general cases. (2) In the formalism using the action-angle variables, the Hamiltonian can have terms which are independent of the angle variables. These terms are called phase-independent terms or shear terms. The tune is then a function of the oscillation amplitudes. In the lowest-order treatment, the (4N)-pole components but not the (4N + 2)-pole components contribute to this dependence. In deriving the resonance <span class="hlt">width</span> analytically, one ignores these terms in the Hamiltonian for the sake of simplicity. If these are retained, one needs at least three extra parameters and the analytical treatment becomes rather unwieldy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024743','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024743"><span id="translatedtitle">Arctic tree <span class="hlt">rings</span> as recorders of variations in light availability</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stine, A. R.; Huybers, P.</p> <p>2014-01-01</p> <p>Annual <span class="hlt">growth</span> <span class="hlt">ring</span> variations in Arctic trees are often used to reconstruct surface temperature. In general, however, the <span class="hlt">growth</span> of Arctic vegetation is limited both by temperature and light availability, suggesting that variations in atmospheric transmissivity may also influence tree-<span class="hlt">ring</span> characteristics. Here we show that Arctic tree-<span class="hlt">ring</span> density is sensitive to changes in light availability across two distinct phenomena: explosive volcanic eruptions (P<0.01) and the recent epoch of global dimming (P<0.01). In each case, the greatest response is found in the most light-limited regions of the Arctic. Essentially no late 20th century decline in tree-<span class="hlt">ring</span> density relative to temperature is seen in the least light-limited regions of the Arctic. Consistent results follow from analysis of tree-<span class="hlt">ring</span> <span class="hlt">width</span> and from individually analysing each of seven tree species. Light availability thus appears an important control, opening the possibility for using tree <span class="hlt">rings</span> to reconstruct historical changes in surface light intensity. PMID:24805143</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6008759','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6008759"><span id="translatedtitle">Planetary <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Greenberg, R.; Brahic, A.</p> <p>1984-01-01</p> <p>Among the topics discussed are the development history of planetary <span class="hlt">ring</span> research, the view of planetary <span class="hlt">rings</span> in astronomy and cosmology over the period 1600-1900, the characteristics of the <span class="hlt">ring</span> systems of Saturn and Uranus, the ethereal <span class="hlt">rings</span> of Jupiter and Saturn, dust-magnetosphere interactions, the effects of radiation forces on dust particles, the collisional interactions and physical nature of <span class="hlt">ring</span> particles, transport effects due to particle erosion mechanisms, and collision-induced transport processes in planetary <span class="hlt">rings</span>. Also discussed are planetary <span class="hlt">ring</span> waves, <span class="hlt">ring</span> particle dynamics in resonances, the dynamics of narrow <span class="hlt">rings</span>, the origin and evolution of planetary <span class="hlt">rings</span>, the solar nebula and planetary disk, future studies of the planetary <span class="hlt">rings</span> by space probes, ground-based observatories and earth-orbiting satellites, and unsolved problems in planetary <span class="hlt">ring</span> dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RaPC...95..346G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RaPC...95..346G"><span id="translatedtitle">Biomonitoring of environmental pollution using <span class="hlt">growth</span> tree <span class="hlt">rings</span> of Tipuana tipu: Quantification by synchrotron radiation total reflection X-ray fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geraldo, S. M.; Canteras, F. B.; Moreira, S.</p> <p>2014-02-01</p> <p>Currently, many studies use the bioindicators to qualitatively and/or quantitatively measure pollution. The analyses of tree <span class="hlt">growth</span> <span class="hlt">rings</span> represent one such bioindicator as changes in the environment are often recorded as impressions in the wood. The main objective of the present study is to examine the <span class="hlt">growth</span> <span class="hlt">rings</span> of Tipuana tipu - a member of the Leguminosae family that is native to Argentina and Bolivia and was introduced in Brazil as an ornamental plant - for potentially toxic elements. T. tipu is one of the most common trees in the urban landscape of Sao Paulo city and would provide an accurate reflection of environment changes. Tree <span class="hlt">ring</span> samples previously dated using Synchrotron Radiation Total Reflection X-ray Fluorescence were collected from strategic locations in Sao Paulo. These locations include Piracicaba (SP) that has little access and small flow traffic and the campus of the University of São Paulo. Some trace elements present concentrations higher than considered as normal in some periods. In São Paulo city, samples collected from the campus of University of São Paulo (Butantã), showed the highest toxicity, with concentrations above the tolerable limit for the elements: Cr, Cu, and Pb. For the samples collected in Piracicaba city, one sample presented highest concentrations for the majority of the elements when compared to the other four samples collected at the same place, exceeding the toxicity limits for: Cr, Ni, Cu, and Pb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780045340&hterms=occult&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Doccult','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780045340&hterms=occult&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Doccult"><span id="translatedtitle">Uranus and the shape of elliptical <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lucke, R. L.</p> <p>1978-01-01</p> <p>It is reported that when the star SAO158687 passed behind the Uranus system, its light was occulted twice by the epsilon (fifth) <span class="hlt">ring</span> of the planet. The first part of the <span class="hlt">ring</span> to occult was about 100 km wide and the second part was about 40 km wide. The variable <span class="hlt">width</span> of the <span class="hlt">ring</span> is accounted for by differences in the orbital eccentricities of the individual particles composing the <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25644125','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25644125"><span id="translatedtitle"><span class="hlt">Growth</span> patterns and age validation from otolith <span class="hlt">ring</span> deposition in New Zealand longfin eels Anguilla dieffenbachii recaptured after 10 years at large.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beentjes, M P; Jellyman, D J</p> <p>2015-03-01</p> <p>In 1998, 9500 juvenile New Zealand longfin eels Anguilla dieffenbachii (mean total length, LT , 42 cm) captured from the lower Clutha River were transferred upstream to Lake Hawea, a high-country oligotrophic lake in the same catchment where recruitment of juvenile eels has been prevented by hydroelectric dams since 1958. A total of 2010 of the transferred A. dieffenbachii were tagged with coded wire tags. Ten years later in 2008, the A. dieffenbachii population in Lake Hawea was sampled resulting in 399 recaptures (distinguishable by the presence of tags and by LT from the remnant resident population of large old A. dieffenbachii) of the 1998 transfers; 79 (19·2%) of the recaptured fish had tags compared with 21·3% at release, indicating good tag retention and low mortality due to tagging. All recaptured tagged A. dieffenbachii were female. Mean annual <span class="hlt">growth</span> over the 10 years since release was 3·80 cm year(-1) for all recaptures and 3·65 cm year(-1) for tag recaptures, and both were significantly greater than the estimate of 2·38 cm year(-1) at release. After release, mean condition (K) increased significantly (P < 0·001) for all recaptures and tag recaptures. Annual length <span class="hlt">growth</span> increment was linear. Tag recaptures showed significant increases in somatic <span class="hlt">growth</span> rate post-transfer, and otoliths from the 2008 recaptured A. dieffenbachii were examined to see whether any similar enhanced <span class="hlt">growth</span> after transfer was incorporated into the otolith structure that would serve as a date stamp. Measurement of otolith <span class="hlt">ring</span> radii indicated that an increase in the radius occurred on most otoliths corresponding to the year after transfer. Because there was 9 years of completed <span class="hlt">growth</span> following the observed <span class="hlt">growth</span> inflection on the otoliths, this was strong evidence that opaque <span class="hlt">rings</span> were formed annually. PMID:25644125</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02241&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02241&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>When seen from the unlit side, the <span class="hlt">rings</span> of Saturn present a much different appearance from that familiar to telescopic observers. Relatively opaque areas like the B <span class="hlt">Ring</span> turn black, while lightly populated zones, such as the C <span class="hlt">Ring</span> and the Cassini Division, prove to excellent diffuse transmitters of sunlight. The A <span class="hlt">Ring</span>, with intermediate opacity, is at an intermediate level of brightness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1054944.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1054944.pdf"><span id="translatedtitle">The <span class="hlt">Width</span> of a Proof</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hanna, Gila</p> <p>2014-01-01</p> <p>This paper's aim is to discuss the concept of <span class="hlt">width</span> of a proof put forward by Timothy Gowers. It explains what this concept means and attempts to show how it relates to other concepts discussed in the existing literature on proof and proving. It also explores how the concept of <span class="hlt">width</span> of a proof might be used productively in the mathematics…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JESS..117..637R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JESS..117..637R"><span id="translatedtitle">Tree-<span class="hlt">ring</span> analysis of teak ( Tectona grandis L.F.) in central India and its relationship with rainfall and moisture index</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ram, Somaru; Borgaonkar, H. P.; Sikder, A. B.</p> <p>2008-10-01</p> <p>Tree-<span class="hlt">ring-width</span> index chronologies of teak ( Tectona grandis L.F.) from three sites in central India have been studied for their dendroclimatic potential. The existence of good correlation among the three site chronologies indicates the influence of common forcing factor to the tree <span class="hlt">growth</span> of the region. Tree <span class="hlt">growth</span> and climate relationship based on correlation analysis revealed the important contribution of moisture index and rainfall rather than the direct influence of the temperature on tree <span class="hlt">growth</span> during different seasons. Significant positive relationship of moisture index and rainfall during the monsoon months as well as on the annual scale with tree-<span class="hlt">ring</span> <span class="hlt">width</span> variations over the region indicates the important role of moisture availability at the root zone. The results suggest that the teak tree-<span class="hlt">ring</span> chronologies can be used as high resolution proxy for past precipitation and moisture level in the environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/753092','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/753092"><span id="translatedtitle">Phase <span class="hlt">width</span> reduction project summary</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Clark, D.J.; Xie, Z.Q.; McMahan, M. A.</p> <p>1999-11-01</p> <p>The purpose of the phase <span class="hlt">width</span> reduction project, 1993--96, was to reduce the phase <span class="hlt">width</span> of the 88-Inch Cyclotron beam on target from 5--10 ns to 1--2 ns for certain experiments, such as Gammasphere, which use time-of-flight identification. Since reducing the phase <span class="hlt">width</span> also reduces beam intensity, tuning should be done to also optimize the transmission. The Multi-turn Collimator slits in the cyclotron center region were used to collimate the early turns radially, thus reducing the phase <span class="hlt">width</span> from about 5 ns to 1--2 ns FWHM for a Gammasphere beam. The effect of the slits on phase <span class="hlt">width</span> was verified with a Fast Faraday Cup and with particle and gamma-ray detectors in the external beamline.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P12A..03C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P12A..03C"><span id="translatedtitle">Saturn's <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuzzi, J. N.</p> <p>2014-12-01</p> <p>The <span class="hlt">rings</span> are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major <span class="hlt">ring</span> science progress over the mission to date, and describe new observations planned for Cassini's final three years. <span class="hlt">Ring</span> Composition and particle sizes: The <span class="hlt">rings</span> are nearly all water ice with no other ices - so why are they reddish? The C <span class="hlt">Ring</span> and Cassini Division are "dirtier" than the more massive B and A <span class="hlt">Rings</span>, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. <span class="hlt">Ring</span> structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main <span class="hlt">ring</span> divisions, the C <span class="hlt">Ring</span> plateau structures, and the B <span class="hlt">Ring</span> irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A <span class="hlt">ring</span>. Rubble pile ringmoons just outside the <span class="hlt">rings</span> may escaped from the <span class="hlt">rings</span>, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the <span class="hlt">rings</span>: Comet fragments set the <span class="hlt">rings</span> to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the <span class="hlt">Rings</span>: The <span class="hlt">ring</span> mass and bombardment play key roles. The <span class="hlt">ring</span> mass is well known everywhere but in the B <span class="hlt">Ring</span> (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient <span class="hlt">rings</span>, of which the current <span class="hlt">ring</span> is just a shadow. During its last three years, the Cassini tour profile will allow entirely new</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820029397&hterms=Currie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCurrie','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820029397&hterms=Currie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCurrie"><span id="translatedtitle">Saturn's E <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baum, W. A.; Kreidl, T.; Westphal, J. A.; Danielson, G. E.; Seidelmann, P. K.; Pascu, D.; Currie, D. G.</p> <p>1981-01-01</p> <p>Observations of the tenuous E <span class="hlt">ring</span> of Saturn made by an earth-based CCD system at the time of the <span class="hlt">ring</span>-plane crossing of March 1980 are presented. The observations were made with the CCD system attached to the 1.8-m Perkins reflector at Lowell Observatory using a pupil mask behind a focal plane mask to suppress telescopic diffraction. Photometric analysis of the CCD images reveal the edge-on brightness profile of the <span class="hlt">ring</span>, beginning at a distance of 3 Saturn radii, to peak sharply in the vicinity of the orbit of Enceladus at about 4 Saturn radii, then decrease to a distance of over 8 Saturn radii. In addition, beyond Enceladus, the edge-on <span class="hlt">width</span> of the <span class="hlt">ring</span> is observed to increase with radial distance, reaching nearly 5 arcsec at 7 Saturn radii. Observations suggest, on the one hand, that the E <span class="hlt">ring</span> is associated with Enceladus and possibly represents material ejected from the satellite, and on the other, that the <span class="hlt">ring</span> is at an early stage in its evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6093088','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6093088"><span id="translatedtitle">Possible red spruce decline: Contributions of tree-<span class="hlt">ring</span> analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Van Deusen, P.C. ); Reams, G.A. ); Cook, E.R. )</p> <p>1991-01-01</p> <p>Debate continues about the cause of apparent unprecedented decreases in <span class="hlt">ring</span> <span class="hlt">width</span> at all elevations, and increasing levels of mortality at high elevations, in red spruce (Picea rubens) stands in the northeastern United States. These <span class="hlt">growth</span> and mortality trends are often used as evidence of red spruce decline, but the possibility remains that they may be occurring naturally. Two hypotheses are being used to explain the causes of red spruce <span class="hlt">growth</span> reduction across its range and increased levels of standing dead at some high-elevation sites. This article summarizes the basic evidence used by advocates of these hypotheses and discusses the strengths of their arguments. The information presented is based primarily on tree-<span class="hlt">ring</span> studies sponsored by the Forest Response Program, which is part of the National Acid Precipitation Assessment Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApSS..329..137X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApSS..329..137X"><span id="translatedtitle">Facile solvothermal synthesis of abnormal <span class="hlt">growth</span> of one-dimensional ZnO nanostructures by <span class="hlt">ring</span>-opening reaction of polyvinylpyrrolidone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, G.; Wang, X. L.; Liu, G. Z.</p> <p>2015-02-01</p> <p>Abnormal <span class="hlt">growth</span> of one-dimensional (1-D) ZnO nanostructures (NSs) have been accomplished with the assistance of polyvinylpyrrolidone (PVP) under a super high alkaline alcoholic solvothermal condition. The products were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The effect of synthetic conditions, such as reaction temperature and the addition of PVP, on the morphologies of ZnO products were investigated. The results show that PVP molecules had the significant role in the transformation of morphologies of ZnO NSs ranging from nanorods, nanoparticles to pyramids, as well as flower-like assembly features. The possible <span class="hlt">growth</span> mechanism of ZnO pyramids was proposed based on <span class="hlt">ring</span>-opening reaction of PVP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA01976&hterms=2o&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D2o','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA01976&hterms=2o&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D2o"><span id="translatedtitle">Uranus <span class="hlt">rings</span> and two moons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1986-01-01</p> <p>Voyager 2 has discovered two 'shepherd' satellites associated with the <span class="hlt">rings</span> of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon <span class="hlt">ring</span>; all nine of the known Uranian <span class="hlt">rings</span> are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon <span class="hlt">ring</span> appears surrounded by a dark halo as a result of this processing; occasional blips seen on the <span class="hlt">ring</span> are also artifacts. Lying inward from the epsilon <span class="hlt">ring</span> are the delta, gamma and eta <span class="hlt">rings</span>; then the beta and alpha <span class="hlt">rings</span>; and finally the barely visible 4, 5 and 6 <span class="hlt">rings</span>. The <span class="hlt">rings</span> have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine <span class="hlt">rings</span> in reflected sunlight. They range in <span class="hlt">width</span> from about 100 km (60 mi) at the widest part of the epsilon <span class="hlt">ring</span> to only a few kilometers for most of the others. The discovery of the two <span class="hlt">ring</span> moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian <span class="hlt">rings</span> and is in good agreement with theoretical predictions of how these narrow <span class="hlt">rings</span> are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JHyd..529..640C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JHyd..529..640C"><span id="translatedtitle">Total water storage dynamics derived from tree-<span class="hlt">ring</span> records and terrestrial gravity observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creutzfeldt, Benjamin; Heinrich, Ingo; Merz, Bruno</p> <p>2015-10-01</p> <p>For both societal and ecological reasons, it is important to understand past and future subsurface water dynamics but estimating subsurface water storage is notoriously difficult. In this pilot study, we suggest the reconstruction of subsurface water dynamics by a multi-disciplinary approach combining hydrology, dendrochronology and geodesy. In a first step, nine complete years of high-precision gravimeter observations are used to estimate water storage changes in the subsurface at the Geodetic Observatory Wettzell in the Bavarian Forest, Germany. The record is extended to 63 years by calibrating a hydrological model against the 9 years of gravimeter observations. The relationship between tree-<span class="hlt">ring</span> <span class="hlt">growth</span> and water storage changes is evaluated as well as that between tree-<span class="hlt">ring</span> <span class="hlt">growth</span> and supplementary hydro-meteorological data. Results suggest that tree-<span class="hlt">ring</span> <span class="hlt">growth</span> is influenced primarily by subsurface water storage. Other variables related to the overall moisture status (e.g., Standardized Precipitation Index, Palmer Drought Severity Index, streamflow) are also strongly correlated with tree-<span class="hlt">ring</span> <span class="hlt">width</span>. While these indices are all indicators of water stored in the landscape, water storage changes of the subsurface estimated by depth-integral measurements give us the unique opportunity to directly reconstruct subsurface water storage dynamics from records of tree-<span class="hlt">ring</span> <span class="hlt">width</span>. Such long reconstructions will improve our knowledge of past water storage variations and our ability to predict future developments. Finally, knowing the relationship between subsurface storage dynamics and tree-<span class="hlt">ring</span> <span class="hlt">growth</span> improves the understanding of the different signal components contained in tree-<span class="hlt">ring</span> chronologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/007318.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/007318.htm"><span id="translatedtitle">Vascular <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... with aberrant subclavian and left ligamentum ateriosus; Congenital heart defect - vascular <span class="hlt">ring</span>; Birth defect heart - vascular <span class="hlt">ring</span> ... accounts for less than 1% of all congenital heart problems. The condition occurs as often in males ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02224&hterms=Neptune&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DNeptune','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02224&hterms=Neptune&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DNeptune"><span id="translatedtitle">Neptune's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p>This 591-second exposure of the <span class="hlt">rings</span> of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main <span class="hlt">rings</span> are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint <span class="hlt">ring</span> and the faint band which extends smoothly from the <span class="hlt">ring</span> roughly halfway between the two bright <span class="hlt">rings</span>. Both of these newly discovered <span class="hlt">rings</span> are broad and much fainter than the two narrow <span class="hlt">rings</span>. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright <span class="hlt">rings</span> have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21699247','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21699247"><span id="translatedtitle"><span class="hlt">Ring</span>-opening copolymerization of maleic anhydride with epoxides: a chain-<span class="hlt">growth</span> approach to unsaturated polyesters.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DiCiccio, Angela M; Coates, Geoffrey W</p> <p>2011-07-20</p> <p>We report the <span class="hlt">ring</span>-opening copolymerization of maleic anhydride with a variety of epoxides catalyzed by a chromium(III) salen complex. Quantitative isomerization of the cis-maleate form of all polymers affords the trans-fumarate analogues. Addition of chain transfer reagents yields low M(n), narrow PDI polymer samples. This method provides access to a range of new unsaturated polyesters with versatile functionality, as well as the first synthesis of high molecular weight poly(propylene fumarate). PMID:21699247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22308169','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22308169"><span id="translatedtitle"><span class="hlt">Width</span> dependent transition of quantized spin-wave modes in Ni{sub 80}Fe{sub 20} square nanorings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Banerjee, Chandrima; Saha, Susmita; Barman, Saswati; Barman, Anjan; Rousseau, Olivier; Otani, YoshiChika</p> <p>2014-10-28</p> <p>We investigated optically induced ultrafast magnetization dynamics in square shaped Ni{sub 80}Fe{sub 20} nanorings with varying <span class="hlt">ring</span> <span class="hlt">width</span>. Rich spin-wave spectra are observed whose frequencies showed a strong dependence on the <span class="hlt">ring</span> <span class="hlt">width</span>. Micromagnetic simulations showed different types of spin-wave modes, which are quantized upto very high quantization number. In the case of widest <span class="hlt">ring</span>, the spin-wave mode spectrum shows quantized modes along the applied field direction, which is similar to the mode spectrum of an antidot array. As the <span class="hlt">ring</span> <span class="hlt">width</span> decreases, additional quantization in the azimuthal direction appears causing mixed modes. In the narrowest <span class="hlt">ring</span>, the spin-waves exhibit quantization solely in azimuthal direction. The different quantization is attributed to the variation in the internal field distribution for different <span class="hlt">ring</span> <span class="hlt">width</span> as obtained from micromagnetic analysis and supported by magnetic force microscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23429480','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23429480"><span id="translatedtitle">Gravitational vortices and clump formation in Saturn's F <span class="hlt">ring</span> during an encounter with Prometheus.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sutton, Phil J; Kusmartsev, Feodor V</p> <p>2013-01-01</p> <p>Saturn <span class="hlt">rings</span> are most beautiful and dynamic places in the solar system, consisting of ice particles in a constant battle between the gravitational forces of Saturn and its many moons. Fan, spiral, propellers, moonlets and streamer-channels observed by CASSINI in the F-<span class="hlt">ring</span> have been attributed to encounters by Prometheus on the F <span class="hlt">ring</span>, with investigations of optical thickness revealing large populations of transient moonlets. Taking into account gravitational interaction between particles and a multi-stranded F-<span class="hlt">ring</span> structure we show that Prometheus' encounters create rotational flows, like atmospheric vortices and the self-gravity enhances the accelerated <span class="hlt">growth</span> and size of moonlets. Vortex patches form caustics, which is a primary cause of the transient particle density clumps of 20 km <span class="hlt">width</span> and 100 km length, and they are elongated to cover an area of 1600 km by 150 km, which may eventually combine into a vortex sheet. PMID:23429480</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572473','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572473"><span id="translatedtitle">Gravitational Vortices And Clump Formation In Saturn's F <span class="hlt">ring</span> During An Encounter With Prometheus</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sutton, Phil J.; Kusmartsev, Feodor V.</p> <p>2013-01-01</p> <p>Saturn <span class="hlt">rings</span> are most beautiful and dynamic places in the solar system, consisting of ice particles in a constant battle between the gravitational forces of Saturn and its many moons. Fan, spiral, propellers, moonlets and streamer-channels observed by CASSINI in the F-<span class="hlt">ring</span> have been attributed to encounters by Prometheus on the F <span class="hlt">ring</span>, with investigations of optical thickness revealing large populations of transient moonlets. Taking into account gravitational interaction between particles and a multi-stranded F-<span class="hlt">ring</span> structure we show that Prometheus' encounters create rotational flows, like atmospheric vortices and the self-gravity enhances the accelerated <span class="hlt">growth</span> and size of moonlets. Vortex patches form caustics, which is a primary cause of the transient particle density clumps of 20 km <span class="hlt">width</span> and 100 km length, and they are elongated to cover an area of 1600 km by 150 km, which may eventually combine into a vortex sheet. PMID:23429480</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NatSR...3E1276S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NatSR...3E1276S"><span id="translatedtitle">Gravitational Vortices And Clump Formation In Saturn's F <span class="hlt">ring</span> During An Encounter With Prometheus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sutton, Phil J.; Kusmartsev, Feodor V.</p> <p>2013-02-01</p> <p>Saturn <span class="hlt">rings</span> are most beautiful and dynamic places in the solar system, consisting of ice particles in a constant battle between the gravitational forces of Saturn and its many moons. Fan, spiral, propellers, moonlets and streamer-channels observed by CASSINI in the F-<span class="hlt">ring</span> have been attributed to encounters by Prometheus on the F <span class="hlt">ring</span>, with investigations of optical thickness revealing large populations of transient moonlets. Taking into account gravitational interaction between particles and a multi-stranded F-<span class="hlt">ring</span> structure we show that Prometheus' encounters create rotational flows, like atmospheric vortices and the self-gravity enhances the accelerated <span class="hlt">growth</span> and size of moonlets. Vortex patches form caustics, which is a primary cause of the transient particle density clumps of 20 km <span class="hlt">width</span> and 100 km length, and they are elongated to cover an area of 1600 km by 150 km, which may eventually combine into a vortex sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/60987','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/60987"><span id="translatedtitle">Tree-<span class="hlt">rings</span> and climate: Implications for Great Basin paleoenvironmental studies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Graybill, D.A.; Rose, M.R.; Nials, F.L.</p> <p>1994-12-31</p> <p>The Quaternary Sciences Center of the Desert Research Institute is currently conducting a multi-phased study of floral, faunal, and geomorphic response to long- and short-term climate change and extremes in assessing Yucca Mountain`s suitability as a high-level nuclear waste repository. Preliminary results of these studies indicate synchronous responses in late Holocene tree-<span class="hlt">ring</span>, palynology and geomorphic records. A tree-<span class="hlt">ring</span> chronology for paleoclimatic reconstruction is developed by collection of multiple cores from 20-60 living trees and a similar number of dead trees in a climate-sensitive location. Samples are cross-dated and every <span class="hlt">growth</span> layer in each specimen is measured to the nearest .001 mm. The measured <span class="hlt">ring</span> <span class="hlt">width</span> series potentially contain a variety of climatic, biological, and anthropogenic signals. Each <span class="hlt">ring</span> <span class="hlt">width</span> series is subjected to a numerical standarization procedure that removes an age-related biological <span class="hlt">growth</span> trend, reduces endogeneous and exogenous stand disturbance factors, and maximizes any climatic signal that is present. Each of these empirically defined components can be graphically portrayed and subjected to further analyses. The geophysical signal analysis techniques involved in the standarized protocol are well-documented and established. The final result is a tree-<span class="hlt">ring</span> chronology that represents regional paleoclimatic variability over the time represented by the sample population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5825072','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5825072"><span id="translatedtitle">Radiation densitometry in tree-<span class="hlt">ring</span> analysis: a review and procedure manual</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parker, M.L.; Taylor, F.G.; Doyle, T.W.; Foster, B.E.; Cooper, C.; West, D.C.</p> <p>1985-01-01</p> <p>An x-ray densitometry of wood facility is being established by the Environmental Sciences Division, Oak Ridge Natioanl Laboratory (ORNL). The objective is to apply tree-<span class="hlt">ring</span> data to determine whether or not there is a fertilizer effect on tree <span class="hlt">growth</span> from increased atmospheric carbon dioxide since the beginning of the industrial era. Intra-<span class="hlt">ring</span> <span class="hlt">width</span> and density data, including <span class="hlt">ring</span>-mass will be detemined from tree-<span class="hlt">ring</span> samples collected from sites located throughout the United States and Canada. This report is designed as a guide to assist ORNL scientists in building the x-ray densitometry system. The history and development of x-ray densitometry in tree-<span class="hlt">ring</span> research is examined and x-ray densitometry is compared with other techniques. Relative wood and tree characteristics are described as are environmental and genetic factors affecting tree <span class="hlt">growth</span> responses. Methods in x-ray densitometry are examined in detail and the techniques used at four operating laboratories are described. Some ways that dendrochronology has been applied in dating, in wood quality, and environmental studies are presented, and a number of tree-<span class="hlt">ring</span> studies in Canada are described. An annotated bibliography of radiation densitometry in tree-<span class="hlt">ring</span> analysis and related subjects is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100042208','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100042208"><span id="translatedtitle">Stacked Corrugated Horn <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sosnowski, John B.</p> <p>2010-01-01</p> <p>This Brief describes a method of machining and assembly when the depth of corrugations far exceeds the <span class="hlt">width</span> and conventional machining is not practical. The horn is divided into easily machined, individual <span class="hlt">rings</span> with shoulders to control the depth. In this specific instance, each of the corrugations is identical in profile, and only differs in diameter and outer profile. The horn is segmented into <span class="hlt">rings</span> that are cut with an interference fit (zero clearance with all machining errors biased toward contact). The interference faces can be cut with a reverse taper to increase the holding strength of the joint. The taper is a compromise between the interference fit and the clearance of the two faces during assembly. Each internal <span class="hlt">ring</span> is dipped in liquid nitrogen, then nested in the previous, larger <span class="hlt">ring</span>. The <span class="hlt">ring</span> is rotated in the nest until the temperature of the two parts equalizes and the pieces lock together. The resulting assay is stable, strong, and has an internal finish that cannot be achieved through other methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011BGD.....811089T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011BGD.....811089T&link_type=ABSTRACT"><span id="translatedtitle">Process based model sheds light on climate signal of mediterranean tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Touchan, R.; Shishov, V. V.; Meko, D. M.; Nouiri, I.; Grachev, A.</p> <p>2011-11-01</p> <p>We use the process-based VS (Vaganov-Shashkin) model to investigate whether a regional Pinus halapensis tree-<span class="hlt">ring</span> chronology from Tunisia can be simulated as a function of climate alone by employing a biological model linking day length and daily temperature and precipitation (AD 1959-2004) from a climate station to <span class="hlt">ring-width</span> variations. We use two periods to calibrate (1982-2004) and verify (1959-1981) the model. We have obtained highly significant positive correlation between the residual chronology and estimated <span class="hlt">growth</span> curve (r = 0.76 p < 0.001). The model shows that the average duration of the growing season is 191 days. On average, soil moisture limits tree-<span class="hlt">ring</span> <span class="hlt">growth</span> for 128 days and temperature for 63 days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3423803','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3423803"><span id="translatedtitle">Fluctuations of cambial activity in relation to precipitation result in annual <span class="hlt">rings</span> and intra-annual <span class="hlt">growth</span> zones of xylem and phloem in teak (Tectona grandis) in Ivory Coast</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dié, Agathe; Kitin, Peter; Kouamé, François N'Guessan; Van den Bulcke, Jan; Van Acker, Joris; Beeckman, Hans</p> <p>2012-01-01</p> <p>Background and Aims Teak forms xylem <span class="hlt">rings</span> that potentially carry records of carbon sequestration and climate in the tropics. These records are only useful when the structural variations of tree <span class="hlt">rings</span> and their periodicity of formation are known. Methods The seasonality of <span class="hlt">ring</span> formation in mature teak trees was examined via correlative analysis of cambial activity, xylem and phloem formation, and climate throughout 1·5 years. Xylem and phloem differentiation were visualized by light microscopy and scanning electron microscopy. Key Results A 3 month dry season resulted in semi-deciduousness, cambial dormancy and formation of annual xylem <span class="hlt">growth</span> <span class="hlt">rings</span> (AXGRs). Intra-annual xylem and phloem <span class="hlt">growth</span> was characterized by variable intensity. Morphometric features of cambium such as cambium thickness and differentiating xylem layers were positively correlated. Cambium thickness was strongly correlated with monthly rainfall (R2 = 0·7535). In all sampled trees, xylem <span class="hlt">growth</span> zones (XGZs) were formed within the AXGRs during the seasonal development of new foliage. When trees achieved full leaf, the xylem in the new XGZs appeared completely differentiated and functional for water transport. Two phloem <span class="hlt">growth</span> <span class="hlt">rings</span> were formed in one growing season. Conclusions The seasonal formation pattern and microstructure of teak xylem suggest that AXGRs and XGZs can be used as proxies for analyses of the tree history and climate at annual and intra-annual resolution. PMID:22805529</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002ASPC..272..263G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002ASPC..272..263G"><span id="translatedtitle">Planetary <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gordon, M. K.; Araki, S.; Black, G. J.; Bosh, A. S.; Brahic, A.; Brooks, S. M.; Charnoz, S.; Colwell, J. E.; Cuzzi, J. N.; Dones, L.; Durisen, R. H.; Esposito, L. W.; Ferrari, C.; Festou, M.; French, R. G.; Giuliatti-Winter, S. M.; Graps, A. L.; Hamilton, D. P.; Horanyi, M.; Karjalainen, R. M.; Krivov, A. V.; Krueger, H.; Larson, S. M.; Levison, H. F.; Lewis, M. C.; Lissauer, J. J.; Murray, C. D.; Namouni, F.; Nicholson, P. D.; Olkin, C. B.; Poulet, F.; Rappaport, N. J.; Salo, H. J.; Schmidt, J.; Showalter, M. R.; Spahn, F.; Spilker, L. J.; Srama, R.; Stewart, G. R.; Yanamandra-Fisher, P.</p> <p>2002-08-01</p> <p>The past two decades have witnessed dramatic changes in our view and understanding of planetary <span class="hlt">rings</span>. We now know that each of the giant planets in the Solar System possesses a complex and unique <span class="hlt">ring</span> system. Recent studies have identified complex gravitational interactions between the <span class="hlt">rings</span> and their retinues of attendant satellites. Among the four known <span class="hlt">ring</span> systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto, or collisions between, parent bodies. Yet, as far as we have come, our understanding is far from complete. The fundamental questions confronting <span class="hlt">ring</span> scientists at the beginning of the twenty-first century are those regarding the origin, age and evolution of the various <span class="hlt">ring</span> systems, in the broadest context. Understanding the origin and age requires us to know the current <span class="hlt">ring</span> properties, and to understand the dominant evolutionary processes and how they influence <span class="hlt">ring</span> properties. Here we discuss a prioritized list of the key questions, the answers to which would provide the greatest improvement in our understanding of planetary <span class="hlt">rings</span>. We then outline the initiatives, missions, and other supporting activities needed to address those questions, and recommend priorities for the coming decade in planetary <span class="hlt">ring</span> science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GPC...133...65P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GPC...133...65P"><span id="translatedtitle">Wet season precipitation during the past century reconstructed from tree-<span class="hlt">rings</span> of a tropical dry forest in Southern Ecuador</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pucha-Cofrep, Darwin; Peters, Thorsten; Bräuning, Achim</p> <p>2015-10-01</p> <p>This study investigates the dendroclimatic potential of tree species in a tropical dry forest in southern Ecuador. From 10 selected tree species, Bursera graveolens and Maclura tinctoria exhibited distinct annual and cross-datable tree-<span class="hlt">rings</span>. It was possible to synchronize individual tree-<span class="hlt">ring</span> series and to establish two tree-<span class="hlt">ring</span> chronologies of 203 and 87 years length, respectively. The characteristic ENSO frequency band is reflected in wavelet power spectra of both chronologies. Both species show a strong correlation between <span class="hlt">ring</span> <span class="hlt">width</span> and precipitation of the wet season (January-May). Strong El Niño events (1972, 1983 and 1998) lead to strong <span class="hlt">growth</span> responses in the tree-<span class="hlt">ring</span> chronologies, whereas 'normal' ENSO events do not trigger long-lasting <span class="hlt">growth</span> responses. The first <span class="hlt">ring-width</span> based wet-season precipitation reconstruction for the past 103 years was developed. Statistical and spatial correlation analysis verified the skills of the reconstructed precipitation which captures a great part of the Rainfall Index over the land area of Ecuador and the equatorial Pacific. Furthermore, teleconnections with central Pacific precipitation and SST patterns were found.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ClDy...44..791T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ClDy...44..791T&link_type=ABSTRACT"><span id="translatedtitle">Probabilistic reconstructions of local temperature and soil moisture from tree-<span class="hlt">ring</span> data with potentially time-varying climatic response</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tolwinski-Ward, S. E.; Tingley, M. P.; Evans, M. N.; Hughes, M. K.; Nychka, D. W.</p> <p>2015-02-01</p> <p>We explore a probabilistic, hierarchical Bayesian approach to the simultaneous reconstruction of local temperature and soil moisture from tree-<span class="hlt">ring</span> <span class="hlt">width</span> observations. The model explicitly allows for differing calibration and reconstruction interval responses of the <span class="hlt">ring-width</span> series to climate due to slow changes in climatology coupled with the biological climate thresholds underlying tree-<span class="hlt">ring</span> <span class="hlt">growth</span>. A numerical experiment performed using synthetically generated data demonstrates that bimodality can occur in posterior estimates of past climate when the data do not contain enough information to determine whether temperature or moisture limitation controlled reconstruction-interval tree-<span class="hlt">ring</span> variability. This manifestation of nonidentifiability is a result of the many-to-one mapping from bivariate climate to time series of tree-<span class="hlt">ring</span> <span class="hlt">widths</span>. The methodology is applied to reconstruct temperature and soil moisture conditions over the 1080-1129 C.E. interval at Methusalah Walk in the White Mountains of California, where co-located isotopic dendrochronologies suggest that observed moisture limitations on tree <span class="hlt">growth</span> may have been alleviated. Our model allows for assimilation of both data sources, and computation of the probability of a change in the climatic controls on <span class="hlt">ring-width</span> relative to those observed in the calibration period. While the probability of a change in control is sensitive to the choice of prior distribution, the inference that conditions were moist and cool at Methuselah Walk during the 1080-1129 C.E. interval is robust. Results also illustrate the power of combining multiple proxy data sets to reduce uncertainty in reconstructions of paleoclimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26789943','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26789943"><span id="translatedtitle">Directed <span class="hlt">Growth</span> of Polymer Nanorods Using Surface-Initiated <span class="hlt">Ring</span>-Opening Polymerization of N-Allyl N-Carboxyanhydride.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Lu; Lahasky, Samuel H; Zhang, Donghui; Garno, Jayne C</p> <p>2016-02-17</p> <p>A stepwise chemistry route was used to prepare arrays of polymer nanostructures of poly(N-allyl glycine) on Si(111) using particle lithography. The nanostructures were used for studying surface reactions with advanced measurements of atomic force microscopy (AFM). In the first step to fabricate the surface platform, isolated nanopores were prepared within a thin film of octadecyltrichlorosilane (OTS). The OTS served as a surface resist, and the areas of nanopores provided multiple, regularly shaped sites for further reaction. An initiator, (3-aminopropyl)triethoxysilane (APTES), was grown selectively inside the nanopores to define sites for polymerization. The initiator attached selectively to the sites of nanopores indicating OTS prevented nonspecific adsorption. Surface-initiated <span class="hlt">ring</span>-opening polymerization of N-allyl N-carboxyanhydride with APTES produced polymer nanorods on the nanodots of APTES presenting amine functional groups. The surface changes for each step were monitored using high resolution atomic force microscopy (AFM). Slight variations in the height of the poly(N-allyl glycine) nanorods were observed which scale correspondingly to the initial dimensions of nanopores. The distance between adjacent polymer nanorods was controlled by the size of mesoparticle masks used in the experiment. This surface platform has potential application in biotechnology for smart coatings or biosensors. PMID:26789943</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013548','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013548"><span id="translatedtitle">Nuclear <span class="hlt">Rings</span> in Galaxies - A Kinematic Perspective</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mazzuca, Lisa M.; Swaters, Robert A.; Knapen, Johan H.; Veilleux, Sylvain</p> <p>2011-01-01</p> <p>We combine DensePak integral field unit and TAURUS Fabry-Perot observations of 13 nuclear <span class="hlt">rings</span> to show an interconnection between the kinematic properties of the <span class="hlt">rings</span> and their resonant origin. The nuclear <span class="hlt">rings</span> have regular and symmetric kinematics, and lack strong non-circular motions. This symmetry, coupled with a direct relationship between the position angles and ellipticities of the <span class="hlt">rings</span> and those of their host galaxies, indicate the <span class="hlt">rings</span> are in the same plane as the disc and are circular. From the rotation curves derived, we have estimated the compactness (v(sup 2)/r) up to the turnover radius, which is where the nuclear <span class="hlt">rings</span> reside. We find that there is evidence of a correlation between compactness and <span class="hlt">ring</span> <span class="hlt">width</span> and size. Radially wide <span class="hlt">rings</span> are less compact, and thus have lower mass concentration. The compactness increases as the <span class="hlt">ring</span> <span class="hlt">width</span> decreases. We also find that the nuclear <span class="hlt">ring</span> size is dependent on the bar strength, with weaker bars allowing <span class="hlt">rings</span> of any size to form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020005141&hterms=Electromagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DElectromagnetism','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020005141&hterms=Electromagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DElectromagnetism"><span id="translatedtitle">Planetary <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cuzzi, Jeffrey N.</p> <p>1994-01-01</p> <p>Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary <span class="hlt">ring</span> particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary <span class="hlt">rings</span>, and the fundamental questions were, why is Saturn the only planet with <span class="hlt">rings</span>, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary <span class="hlt">ring</span> systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise <span class="hlt">ring</span> systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that <span class="hlt">ring</span> systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary <span class="hlt">ring</span> systems, if not the <span class="hlt">ring</span> systems themselves, are considerably younger than the solar system</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Icar..226.1275S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Icar..226.1275S"><span id="translatedtitle">The vertical structure of the F <span class="hlt">ring</span> of Saturn from <span class="hlt">ring</span>-plane crossings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scharringhausen, Britt R.; Nicholson, Philip D.</p> <p>2013-11-01</p> <p>We present a photometric model of the <span class="hlt">rings</span> of Saturn which includes the main <span class="hlt">rings</span> and an F <span class="hlt">ring</span>, inclined to the main <span class="hlt">rings</span>, with a Gaussian vertical profile of optical depth. This model reproduces the asymmetry in brightness between the east and west ansae of the <span class="hlt">rings</span> of Saturn that was observed by the Hubble Space Telescope (HST) within a few hours after the Earth <span class="hlt">ring</span>-plane crossing (RPX) of 10 August 1995. The model shows that during this observation the inclined F <span class="hlt">ring</span> unevenly blocked the east and west ansae of the main <span class="hlt">rings</span>. The brightness asymmetry produced by the model is highly sensitive to the vertical thickness and radial optical depth of the F <span class="hlt">ring</span>. The F-<span class="hlt">ring</span> model that best matches the observations has a vertical full <span class="hlt">width</span> at half maximum of 13 ± 7 km and an equivalent depth of 10 ± 4 km. The model also reproduces the shape of the HST profiles of <span class="hlt">ring</span> brightness vs. distance from Saturn, both before and after the time of <span class="hlt">ring</span>-plane crossing. Smaller asymmetries observed before the RPX, when the Earth was on the dark side of the <span class="hlt">rings</span>, cannot be explained by blocking of the main <span class="hlt">rings</span> by the F <span class="hlt">ring</span> or vice versa and are probably instead due to the intrinsic longitudinal variation exhibited by the F <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26086094','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26086094"><span id="translatedtitle">Arabidopsis <span class="hlt">RING</span> E3 ubiquitin ligase AtATL80 is negatively involved in phosphate mobilization and cold stress response in sufficient phosphate <span class="hlt">growth</span> conditions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suh, Ji Yeon; Kim, Woo Taek</p> <p>2015-08-01</p> <p>Phosphate (Pi) remobilization in plants is critical to continuous <span class="hlt">growth</span> and development. AtATL80 is a plasma membrane (PM)-localized <span class="hlt">RING</span> E3 ubiquitin (Ub) ligase that belongs to the Arabidopsis Tóxicos en Levadura (ATL) family. AtATL80 was upregulated by long-term low Pi (0-0.02 mM KH2PO4) conditions in Arabidopsis seedlings. AtATL80-overexpressing transgenic Arabidopsis plants (35S:AtATL80-sGFP) displayed increased phosphorus (P) accumulation in the shoots and lower biomass, as well as reduced P-utilization efficiency (PUE) under high Pi (1 mM KH2PO4) conditions compared to wild-type plants. The loss-of-function atatl80 mutant line exhibited opposite phenotypic traits. The atatl80 mutant line bolted earlier than wild-type plants, whereas AtATL80-overexpressors bloomed significantly later and produced lower seed yields than wild-type plants under high Pi conditions. Thus, AtATL80 is negatively correlated not only with P content and PUE, but also with biomass and seed yield in Arabidopsis. In addition, AtATL80-overexpressors were significantly more sensitive to cold stress than wild-type plants, while the atatl80 mutant line exhibited an increased tolerance to cold stress. Taken together, our results suggest that AtATL80, a PM-localized ATL-type <span class="hlt">RING</span> E3 Ub ligase, participates in the Pi mobilization and cold stress response as a negative factor in Arabidopsis. PMID:26086094</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...03..214S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...03..214S"><span id="translatedtitle">On the maximal diphoton <span class="hlt">width</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvio, Alberto; Staub, Florian; Strumia, Alessandro; Urbano, Alfredo</p> <p>2016-03-01</p> <p>Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal <span class="hlt">width</span> into γγ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812343Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812343Z&link_type=ABSTRACT"><span id="translatedtitle">Challenges in Establishing Multi-Millennial Tree <span class="hlt">Ring</span> Records for the Holocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ziehmer, Malin Michelle; Nicolussi, Kurt; Schlüchter, Christian; Leuenberger, Markus</p> <p>2016-04-01</p> <p>Recent finds of wood remains from glacier forefields and peat bogs along a SW-NE transect in the Alps represent a unique high-frequency archive which allows the reconstruction of climate variability over the entire Holocene. We use a multi-proxy approach that combines both tree <span class="hlt">ring</span> <span class="hlt">width</span> and multiple stable isotope chronologies by establishing highly resolved tree <span class="hlt">ring</span> and stable isotope records from calendar-dated wood covering the past 9000 years. Therefore, tree <span class="hlt">ring</span> <span class="hlt">width</span> and stable isotope series are generated by a standardized procedure, where first the tree <span class="hlt">ring</span> <span class="hlt">widths</span> are measured and samples are calendrically dated by means of tree <span class="hlt">ring</span> analysis. Afterwards, samples are cut into 5-year tree <span class="hlt">ring</span> blocks, cellulose is extracted and crushed by ultrasonic homogenization, and subsequently, the stable isotopes of carbon, oxygen and hydrogen are simultaneously measured. Although the sample preparation follows a standardized procedure, the establishment of the multi-millennial tree <span class="hlt">ring</span> and isotope chronologies is not straightforward. By investigating the individual measurement series from the Early and Mid-Holocene as well as recent samples from living trees from key sites - which will provide the connection of the Holocene tree <span class="hlt">ring</span> series to the present - the individual measurement series reveal effects due to different sampling sites, tree species, <span class="hlt">growth</span> trend, potential degree of decay and cellulose content. These specific effects influence both the tree <span class="hlt">ring</span> <span class="hlt">width</span>, and to a higher degree the stable isotope series. For instance, the measured deuterium records reveal a species-specific isotope signature for the investigated species Larix decidua and Pinus cembra, which is not resembled in the oxygen and carbon records. In order to establish stable isotope chronologies which span the time period from 9000 years b2k to the present, such tree specific features need to be corrected from the individual time series. In this study, we try to overcome these various</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25345032','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25345032"><span id="translatedtitle">[Dendroclimatic potentials for the tree <span class="hlt">rings</span> of Huangshan pine (Pinus taiwanensis ) at Xiaolinhai in the western Dabie Mountains, China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peng, Jian-Feng; Li, Guo-Dong; Li, Ling-Ling</p> <p>2014-07-01</p> <p>By using the dendrochronology research methods, this paper developed the 1915-2011 tree <span class="hlt">ring-width</span> standard chronology of the Huangshan pine (Pinus taiwanesis) at the north slope of western Dabie Mountains in the junction of Hubei, Henan and Anhui provinces. High mean sensitivity (MS) indicated that there was conspicuous high-frequency climate signals and high first-order autocorrelation (AC) showed there were significant lag-effects of tree previous <span class="hlt">growth</span>. The higher signal-to-noise ratio (SNR) and expressed population signal (EPS) indicated that the trees had high levels of common climate signals. Correlations between the tree <span class="hlt">ring-width</span> standard chronology and climatic factors (1959-2011) revealed the significant influences of temperature, precipitation and relative humidity on the tree <span class="hlt">width</span> <span class="hlt">growth</span> of Huangshan pine by the end of growing season (September and October). Significant positive correlations were found between the tree-<span class="hlt">ring</span> indices and the Palmer drought severity index (PDSI) of current September and October. In conclusion, the combination of water and heat of September and October is the major effect factor for the <span class="hlt">growth</span> of Huangshan pine in western Dabie Mountains. PMID:25345032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27573111','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27573111"><span id="translatedtitle">Wall proficient E. coli capable of sustained <span class="hlt">growth</span> in the absence of the Z-<span class="hlt">ring</span> division machine.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mercier, Romain; Kawai, Yoshikazu; Errington, Jeff</p> <p>2016-01-01</p> <p>The peptidoglycan cell wall is a major protective external sheath in bacteria and a key target for antibiotics(1). Peptidoglycan is present in virtually all bacteria, suggesting that it was probably present in the last bacterial common ancestor(2). Cell wall expansion is orchestrated by cytoskeletal proteins related to actin (MreB) and tubulin (FtsZ)(3). FtsZ is a key essential player in a highly organized division machine that directs an invaginating annulus of cell wall peptidoglycan. The recent discovery that cell-wall-less bacteria (L-forms) can grow and divide independently of FtsZ(4,5), provided a means of generating an ftsZ null mutant of Escherichia coli. Remarkably, we have been able to isolate variants of E. coli that lack FtsZ but are capable of efficient <span class="hlt">growth</span> in a walled state. Genetic analysis reveals that a combination of mutations is needed for this phenotype. Importantly, the suppressive mutations lead to a major cell shape change, from the normal cylindrical shape to a branched and bulging, ramified shape, which we call 'coli-flower'. The results highlight the versatility of bacterial cells and illustrate possible evolutionary routes leading to the emergence of specialized bacteria, such as pathogenic Chlamydia or aquatic Planctomycetes, that lack FtsZ but retain the cell wall(6-8). PMID:27573111</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EPSC....9..633S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EPSC....9..633S&link_type=ABSTRACT"><span id="translatedtitle">Propellers in Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.</p> <p>2014-04-01</p> <p> detection in UVIS β Centauri Rev96 occultation at r=94,958km offers insight into the morphology of the discovered objects in B <span class="hlt">ring</span>. The feature is statistically significant, consists of 6 consequent high counts, and represents a gap with a <span class="hlt">width</span> of 300m. Similar to the Bleriot occultation in Persei Rev42, the B <span class="hlt">ring</span> β Centauri occultation also shows a very prominent gap and a single flanking higher density wake. The significance of the UVIS features was confirmed using statistical T-test. The result from UVIS occultation together with dozen feature detections in ISS NAC images demonstrates beyond reasonable doubt that the presented B <span class="hlt">ring</span> features are indeed propellers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.1427K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.1427K"><span id="translatedtitle">Climatic variations on longest tree-<span class="hlt">ring</span> chronologies for Kola Peninsula and Finnish Lapland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasatkina, E. A.; Shumilov, O. I.; Timonen, M.; Mielikainen, K.; Helama, S.; Kanatjev, A. G.; Kirtsideli, I. Yu.</p> <p>2010-05-01</p> <p>We investigated the external factor (solar activity, volcanic eruptions) influence on tree <span class="hlt">growth</span> at high latitudes. We analysed a 561-year tree-<span class="hlt">ring</span> record of pine (Pinus sylvestris L.) and a 676-year juniper (Juniperus Sibirica Burgst.) tree-<span class="hlt">ring</span> chronology collected nearby the northern timberline (67.77-68.63N; 33.25-36.52 E) at the Kola Peninsula, northwestern Russia. As well known the climatic impacts of solar and volcanic activity vary regionally, and major volcanic eruptions do not always result in regional cooling. A response of tree <span class="hlt">growth</span> at the Kola Peninsula to climatic changes due to solar variability and volcanic eruptions was revealed. For example, Dalton minimum of solar activity (1801-1816 AD) and Laki (1783 AD) and Tambora (1815 AD) volcanic eruptions appeared to cause the greatest <span class="hlt">ring-width</span> reduction and cooling. The minima of solar activity Sporer (1416-1534 AD) and Maunder (1645-1715 AD) were as well accompanied by temperature decreases. Intervals with an absence of significant volcanic eruptions correspond to intervals of increased <span class="hlt">ring-width</span> values. A superposed epoch analysis of 19 large (Volcanic Explosivity Index, VEI>5) volcanic events revealed a significant suppression of tree <span class="hlt">growth</span> for up to 8 years following volcanic eruptions. The similar effect (supression of tree <span class="hlt">growth</span> after powerful volcanic eruptions) was obtained under analysis of the 7641-year supra-long pine tree-<span class="hlt">ring</span> chronology for Finnish Lapland. Our results documenting the regional climatic impacts of solar and volcanic activity permit us to understand the dynamics of the climate system and its response to external forcing. This work is financially supported by grant from Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27301603','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27301603"><span id="translatedtitle">Vascular <span class="hlt">rings</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K</p> <p>2016-06-01</p> <p>The term vascular <span class="hlt">ring</span> refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular <span class="hlt">rings</span> are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular <span class="hlt">ring</span> is best established by CT imaging that can accurately delineate the anatomy of the vascular <span class="hlt">ring</span> and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular <span class="hlt">ring</span> is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular <span class="hlt">rings</span> should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. PMID:27301603</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7195646','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7195646"><span id="translatedtitle">Possible bias in tree-<span class="hlt">ring</span> time series due to mortality</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lucier, A A; Warnick, W L; Hyink, D M</p> <p>1989-07-01</p> <p>This article discusses the possible bias in tree-<span class="hlt">ring</span> time series studies extending from the year of sample collection to a prepollution period. The authors hypothesizes that normal mortality (i.e., mortality not associated with sudden disturbance) can cause reduced tree <span class="hlt">ring</span> <span class="hlt">widths</span> in years preceding actual tree death and produce a bias toward smaller and more variable <span class="hlt">ring</span> <span class="hlt">widths</span> at the end of the tree-<span class="hlt">ring</span> time series.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2871W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2871W"><span id="translatedtitle">From process to proxy: Ecological challenges and opportunities of tree-<span class="hlt">ring</span> based environmental reconstructions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilmking, Martin; Buras, Allan; Heinrich, Ingo; Scharnweber, Tobias; Simard, Sonia; Smiljanic, Marko; van der Maaten, Ernst; van der Maaten-Theunissen, Marieke</p> <p>2014-05-01</p> <p>Trees are sessile, long-living organisms and as such constantly need to adapt to changing environmental conditions. Accordingly, they often show high phenotypic plasticity (the ability to change phenotypic traits, such as allocation of resources) in response to environmental change. This high phenotypic plasticity is generally considered as one of the main ingredients for a sessile organism to survive and reach high ages. Precisely because of the ability of trees to reach old age and their in-ability to simply run away when conditions get worse, <span class="hlt">growth</span> information recorded in tree <span class="hlt">rings</span> has long been used as a major environmental proxy, covering time scales from decades to millennia. Past environmental conditions (e.g. climate) are recorded in i.e. annual tree-<span class="hlt">ring</span> <span class="hlt">width</span>, early- and latewood <span class="hlt">width</span>, wood density, isotopic concentrations, cell anatomy or wood chemistry. One prerequisite for a reconstruction is that the relationship between the environmental variable influencing tree <span class="hlt">growth</span> and the tree-<span class="hlt">growth</span> variable itself is stable through time. This, however, might contrast the ecological theory of high plasticity and the trees ability to adapt to change. To untangle possible mechanisms leading to stable or unstable relationships between tree <span class="hlt">growth</span> and environmental variables, it is helpful to have exact site information and several proxy variables of each tree-<span class="hlt">ring</span> series available. Although we gain insight into the environmental history of a sampling site when sampling today, this is extremely difficult when using archeological wood. In this latter case, we face the additional challenge of unknown origin, provenance and (or) site conditions, making it even more important to use multiple proxy time-series from the same sample. Here, we review typical examples, where the relationship between tree <span class="hlt">growth</span> and environmental variables seems 1) stable and 2) instable through time, and relate these two cases to ecological theory. Based on ecological theory, we then</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/988765','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/988765"><span id="translatedtitle">Storage <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fischer, W.</p> <p>2011-01-01</p> <p>Storage <span class="hlt">rings</span> are circular machines that store particle beams at a constant energy. Beams are stored in <span class="hlt">rings</span> without acceleration for a number of reasons (Tab. 1). Storage <span class="hlt">rings</span> are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage <span class="hlt">rings</span> such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage <span class="hlt">ring</span> but may not be extracted (Fig. 1). Accelerator <span class="hlt">rings</span> such as synchrotrons are used as storage <span class="hlt">rings</span> before and after acceleration. Particles stored in <span class="hlt">rings</span> include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10{sup -6} eV to 3.5 x 10{sup 12} eV (LHC, 7 x 10{sup 12} eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in <span class="hlt">rings</span> requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage <span class="hlt">rings</span>. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820033629&hterms=occult&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Doccult','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820033629&hterms=occult&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Doccult"><span id="translatedtitle">No evidence of <span class="hlt">rings</span> around Neptune</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elliot, J. L.; Mink, D. J.; Baron, R. L.; Dunham, E.; Pingree, J. E.; French, R. G.; Elias, J. H.; Liller, W.; Nicholson, P. D.; Jones, T. J.</p> <p>1981-01-01</p> <p>The results of two observations of stellar occultations of Neptune to determine if the planet has a <span class="hlt">ring</span> system are reported. The sightings were made from Mt. Stromlo, Mauna Kea, and Cerro Tololo, noting that an equatorial <span class="hlt">ring</span> would subtend only two arcsec of view. An upper accretion limit was defined to set the region around Neptune where <span class="hlt">rings</span>, rather than satellites, could form. The intensities of the starlight from the two selected stars were recorded by photometers on magnetic tape during the occultation period. One of the stars did not occult, but passed through the entire region where a <span class="hlt">ring</span> system might be present. No definitive evidence for <span class="hlt">rings</span> was found, although an optical depth for a Neptunian <span class="hlt">ring</span> was calculated at 0.07, with a <span class="hlt">width</span> of more than 5 km and a radius of 31,400 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol3/pdf/CFR-2012-title14-vol3-sec121-95.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title14-vol3/pdf/CFR-2012-title14-vol3-sec121-95.pdf"><span id="translatedtitle">14 CFR 121.95 - Route <span class="hlt">width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>..., FLAG, AND SUPPLEMENTAL OPERATIONS Approval of Routes: Domestic and Flag Operations § 121.95 Route <span class="hlt">width</span>... routes in the case of certificate holders conducting flag operations) have a <span class="hlt">width</span> equal to...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GPC...122..140C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GPC...122..140C"><span id="translatedtitle">A cluster of stratospheric volcanic eruptions in the AD 530s recorded in Siberian tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Churakova (Sidorova), Olga V.; Bryukhanova, Marina V.; Saurer, Matthias; Boettger, Tatjana; Naurzbaev, Mukhtar M.; Myglan, Vladimir S.; Vaganov, Eugene A.; Hughes, Malcolm K.; Siegwolf, Rolf T. W.</p> <p>2014-11-01</p> <p>Recently published, improved chronologies for volcanic sulfate in Greenland and Antarctic ice permit a comparison of the <span class="hlt">growth</span> responses of absolutely annually dated tree <span class="hlt">rings</span> at three locations in Siberia with annual ice-core records of volcanic eruptions centered on AD 536. For the first time for this region and period, we present unique data sets for tree-<span class="hlt">ring</span> <span class="hlt">width</span>, cell-wall thickness, δ13C and δ18O in cellulose. These were based on multiple samples from relict wood of larch obtained from two sites close to the northern limit of tree <span class="hlt">growth</span> on the Taimyr Peninsula and in northeastern Yakutia, and at a high-elevation, location 20° further South in the Altai Mts. An event in AD 536 was associated with different, but marked, changes in tree-<span class="hlt">ring</span> parameters at the high-latitude sites compared with the high elevation site. An AD 541 event was associated with its own distinctive tree-<span class="hlt">ring</span> responses across the three sites and multiple variables. The years after AD 532 were marked by a strong and sustained decrease in <span class="hlt">growth</span> at the high-elevation, more southerly, site. The combination of improved ice-core chronology for the climatically effective volcanic eruptions of this part of the 6th century AD, and an array of tree-<span class="hlt">ring</span> sites with different climates and multiple tree-<span class="hlt">ring</span> variables permits a richer description of tree responses to this cluster of events. The pattern of tree-<span class="hlt">ring</span> parameter responses at the three locations in AD 536, AD 541, and perhaps AD 532 is consistent with responses to climatically effective volcanic eruptions influencing tree response in those and subsequent years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980Msngr..21...29D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980Msngr..21...29D"><span id="translatedtitle"><span class="hlt">Ring</span> Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dennefeld, M.; Materne, J.</p> <p>1980-09-01</p> <p>Among the 338 exotic, intriguing and/or fascinating objects contained in Arp's catalogue of peculiar galaxies, two, Arp 146 and 147, are calling special attention as a presumably separate class of objects displaying closed <span class="hlt">rings</span> with almost empty interior. It is difficult to find out when, historically speaking, attention was called first to this type of object as a peculiar class, but certainly ga1axies with <span class="hlt">rings</span> were widely found and recognized in the early sixties, ul}der others by Vorontsov-Velyaminov (1960), Sandage (1961) in the Hubble Atlas or de Vaucouleurs (1964) in the first reference catalogue of ga1axies. The most recent estimates by Arp and Madore (1977) from a search on about 200 Schmidt plates covering 7,000 square degrees give 3.6 per cent of <span class="hlt">ring</span> galaxies among 2,784 peculiar galaxies found. However, despite the mythological perfection associated with a circle, some ordering is necessary before trying to understand the nature of such objects. This is particularly true because a large fraction of those galaxies with <span class="hlt">rings</span> are probably normal spiral galaxies of type RS or S(r) as defined by de Vaucouleurs, where the spiral arms are simply "closing the circle". A good example of such "ordinary" galaxy is NGC 3081 in the Hubble Atlas .</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title23-vol1/pdf/CFR-2014-title23-vol1-sec658-15.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title23-vol1/pdf/CFR-2014-title23-vol1-sec658-15.pdf"><span id="translatedtitle">23 CFR 658.15 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-04-01</p> <p>... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, <span class="hlt">WIDTH</span> AND WEIGHT LIMITATIONS § 658.15 <span class="hlt">Width</span>. (a) No State shall impose a <span class="hlt">width</span> limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title23-vol1/pdf/CFR-2011-title23-vol1-sec658-15.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title23-vol1/pdf/CFR-2011-title23-vol1-sec658-15.pdf"><span id="translatedtitle">23 CFR 658.15 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-04-01</p> <p>... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, <span class="hlt">WIDTH</span> AND WEIGHT LIMITATIONS § 658.15 <span class="hlt">Width</span>. (a) No State shall impose a <span class="hlt">width</span> limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title23-vol1/pdf/CFR-2012-title23-vol1-sec658-15.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title23-vol1/pdf/CFR-2012-title23-vol1-sec658-15.pdf"><span id="translatedtitle">23 CFR 658.15 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-04-01</p> <p>... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, <span class="hlt">WIDTH</span> AND WEIGHT LIMITATIONS § 658.15 <span class="hlt">Width</span>. (a) No State shall impose a <span class="hlt">width</span> limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title23-vol1/pdf/CFR-2013-title23-vol1-sec658-15.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title23-vol1/pdf/CFR-2013-title23-vol1-sec658-15.pdf"><span id="translatedtitle">23 CFR 658.15 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-04-01</p> <p>... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, <span class="hlt">WIDTH</span> AND WEIGHT LIMITATIONS § 658.15 <span class="hlt">Width</span>. (a) No State shall impose a <span class="hlt">width</span> limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title23-vol1/pdf/CFR-2010-title23-vol1-sec658-15.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title23-vol1/pdf/CFR-2010-title23-vol1-sec658-15.pdf"><span id="translatedtitle">23 CFR 658.15 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, <span class="hlt">WIDTH</span> AND WEIGHT LIMITATIONS § 658.15 <span class="hlt">Width</span>. (a) No State shall impose a <span class="hlt">width</span> limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26142450','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26142450"><span id="translatedtitle">Functional adjustments of xylem anatomy to climatic variability: insights from long-term Ilex aquifolium tree-<span class="hlt">ring</span> series.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rita, Angelo; Cherubini, Paolo; Leonardi, Stefano; Todaro, Luigi; Borghetti, Marco</p> <p>2015-08-01</p> <p>The present study assessed the effects of climatic conditions on radial <span class="hlt">growth</span> and functional anatomical traits, including <span class="hlt">ring</span> <span class="hlt">width</span>, vessel size, vessel frequency and derived variables, i.e., potential hydraulic conductivity and xylem vulnerability to cavitation in Ilex aquifolium L. trees using long-term tree-<span class="hlt">ring</span> time series obtained at two climatically contrasting sites, one mesic site in Switzerland (CH) and one drought-prone site in Italy (ITA). Relationships were explored by examining different xylem traits, and point pattern analysis was applied to investigate vessel clustering. We also used generalized additive models and bootstrap correlation functions to describe temperature and precipitation effects. Results indicated modified radial <span class="hlt">growth</span> and xylem anatomy in trees over the last century; in particular, vessel frequency increased markedly at both sites in recent years, and all xylem traits examined, with the exception of xylem cavitation vulnerability, were higher at the CH mesic compared with the ITA drought site. A significant vessel clustering was observed at the ITA site, which could contribute to an enhanced tolerance to drought-induced embolism. Flat and negative relationships between vessel size and <span class="hlt">ring</span> <span class="hlt">width</span> were observed, suggesting carbon was not allocated to radial <span class="hlt">growth</span> under conditions which favored stem water conduction. Finally, in most cases results indicated that climatic conditions influenced functional anatomical traits more substantially than tree radial <span class="hlt">growth</span>, suggesting a crucial role of functional xylem anatomy in plant acclimation to future climatic conditions. PMID:26142450</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/181935','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/181935"><span id="translatedtitle">Drought frequency in central California since 101 B.C. recordered in giant sequoia tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hughes, M.K.; Brown, P.M.</p> <p>1992-01-01</p> <p>Well replicated tree-<span class="hlt">ring</span> <span class="hlt">width</span> index chronologies have been developed for giant sequoia at three sites in the Sierra Nevada, California. Extreme low-<span class="hlt">growth</span> events in these chronologies correspond with regional drought events in the twentieth century in the San Joaquin drainage, in which the giant sequoia sites are located. This relationship is based upon comparison of tree-<span class="hlt">ring</span> indices with August Palmer Drought Severity Indices for California Climate Division 5. <span class="hlt">Ring-width</span> indices in the lowest decile from each site were compared. The frequency of low-<span class="hlt">growth</span> events which occurred at all three sites in the same year is reconstructed from 101 B.C. to A.D. 1988. The inferred frequency of severe drought events changes through time, sometimes suddenly. The period from roughly 1850 to 1950 had one of the lowest frequencies of drought of any one hundred year period in the 2089 year record. The twentieth century so far has had a below-average frequency of extreme droughts. 26 refs., 6 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ClDy....6..161H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ClDy....6..161H"><span id="translatedtitle">Drought frequency in central California since 101 B.C. recorded in giant sequoia tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, Malcolm K.; Brown, Peter M.</p> <p>1992-01-01</p> <p>Well replicated tree-<span class="hlt">ring</span> <span class="hlt">width</span> index chronologies have been developed for giant sequoia at three sites in the Sierra Nevada, California. Extreme low-<span class="hlt">growth</span> events in these chronologies correspond with regional drought events in the twentieth century in the San Joaquin drainage, in which the giant sequoia sites are located. This relationship is based upon comparison of tree-<span class="hlt">ring</span> indices with August Palmer Drought Severity Indices for California Climate Division 5. <span class="hlt">Ring-width</span> indices in the lowest decile from each site were compared. The frequency of low-<span class="hlt">growth</span> events which occurred at all three sites in the same year is reconstructed from 101 B.C. to A.D. 1988. The inferred frequency of severe drought events changes through time, sometimes suddenly. The period from roughly 1850 to 1950 had one of the lowest frequencies of drought of any one hundred year period in the 2089 year record. The twentieth century so far has had a below-average frequency of extreme droughts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/960972','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/960972"><span id="translatedtitle">Fjords in viscous fingering: selection of <span class="hlt">width</span> and opening scale</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mineev-weinstein, Mark; Ristroph, Leif; Thrasher, Matthew; Swinney, Harry</p> <p>2008-01-01</p> <p>Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian <span class="hlt">growth</span> equation.) Experiments in rectangular and circular geometries yield fjords with base <span class="hlt">widths</span> {lambda}{sub c}/2, where {lambda}{sub c} is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0{sup o}{+-}1.0{sup o}. These selection rules hold for a wide range of pumping rates and fjord lengths, <span class="hlt">widths</span>, and directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.B11A1009W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.B11A1009W"><span id="translatedtitle">Fog and Vegetation on the California Channel Islands: A Tree <span class="hlt">Ring</span> and Satellite Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, P.; Still, C.; Fischer, D.; Leavitt, S.</p> <p>2005-12-01</p> <p>Tree-<span class="hlt">ring</span> <span class="hlt">width</span> and stable isotope composition of rare pines in Channel Islands National Park reflect annual variations in water availability. α-cellulose was isolated from Bishop Pine ( Pinus muricata) cores from Santa Cruz Island (SCI). Individual annual <span class="hlt">rings</span> from 1979-2003 were analyzed for carbon-13 (n = 4 trees). An average δ13C chronology was created and annual atmospheric 13CO2 at La Jolla Pier, CA was subtracted to detrend the chronology for the steadily decreasing δ13C of atmospheric CO2 that has resulted from anthropogenic emissions and biomass burning. Early and latewood δ13C were negatively correlated with annual rainfall in the SCI central valley (r = -0.5057, r = -0.6447, respectively). An annual <span class="hlt">ring</span> <span class="hlt">width</span> chronology (1908-2004) was also created from Torrey Pine ( Pinus torreyana) tree cores (n=17) collected on Santa Rosa Island. <span class="hlt">Ring</span> <span class="hlt">width</span> was positively correlated with SCI rainfall (r = 0.6993). On average, 87% of this precipitation falls between November and March. However, tree <span class="hlt">growth</span> as measured by dendrometer bands continues throughout the summer months suggesting an additional source of water. Summer is also the peak fog season for the Islands. The last rain of the 2004 growing season was on March 1 and monthly NDVI data derived from MODIS show that the vast majority of the vegetation on SCI was dormant by mid-May. When summer NDVI is overlaid on an image of average summer-time 10:30AM cloud cover, created using a derivative of the MODIS cloud-mask product, it appears that the greenest parts of SCI during summer months are those regions that experience the most summertime cloud cover. The distribution of Bishop Pine also seems to be limited to elevations that intercept cloud banks, as opposed to regions that simply experience cloud cover. It is therefore possible that these tree <span class="hlt">ring</span> <span class="hlt">width</span> and stable isotope records document the intensity of summer fog inundation in addition to rainfall. Because we have observed consistently significant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP43B1486S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP43B1486S"><span id="translatedtitle">Projecting Future Water Availability in the Great Lakes Megalopolis: Reconstructing Lake Michigan-Huron Lake Level and Regional Hydroclimate Using Tree <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, K. R.</p> <p>2014-12-01</p> <p>The ability to accurately predict water availability in the cities surrounding Lake Michigan-Huron becomes particularly difficult when the uncertain effects of climate change, such as changes in precipitation patterns and evaporation rates, are considered. Lake level reconstructions provide useful model inputs to better predict this availability. Annual tree-<span class="hlt">ring</span> <span class="hlt">widths</span> have been successfully utilized in reconstructions of lake levels in the Great Lakes region via the creation of proxy datasets of temperature and precipitation that are then input into a multilinear regression model to reconstruct annual average lake level. Here, the combination of this approach with analysis of instrumental records of precipitation and stream flow input allows for a more comprehensive understanding of regional hydroclimate and improved projection of future water resource availability. Annual tree-<span class="hlt">ring</span> <span class="hlt">widths</span> of cores collected from four old-<span class="hlt">growth</span> forests near southern Lake Michigan were combined with over 30 archived tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies from the Great Lakes region and used to create proxy datasets of temperature and precipitation. A multilinear regression model related these proxy variables to Lake Michigan-Huron lake level and stream flow of the Saint Clair River, which flows into Lake Michigan-Huron, for the period of available instrumental record (1860-present). When possible, the available tree-<span class="hlt">ring</span> <span class="hlt">widths</span> were used to reconstruct these variables for years prior to the instrumental record. Timing and severity of rainfall events were also analyzed to identify spatial and temporal patterns and their variability over time. The combination of updated tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies, chronologies from newly sampled sites, and instrumental records of various indicators of water availability provides novel and valuable insight into the future lake level of Lake Michigan-Huron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMGC24B..03T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMGC24B..03T"><span id="translatedtitle">Stable carbon isotopes and drought signal in the tree-<span class="hlt">rings</span> of northern white-cedar trees from boreal central Canada. (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tardif, J. C.; Au, R.</p> <p>2010-12-01</p> <p> both radial <span class="hlt">growth</span> and carbon assimilation, particularly during the month of June in the current growing season. During this month, the <span class="hlt">ring-width</span> index was sensitive to moisture stress (positive and negative association with precipitation and temperature, respectively) whereas the δ13C index showed enrichment with increasing temperature and drought index. Our results also suggested that in T. occidentalis <span class="hlt">ring</span> <span class="hlt">width</span> was more responsive to prolonged drought than δ13C since periods of decreased radial <span class="hlt">growth</span> most often coincided with documented drought intervals. Past experimental studies had indicated that young T. occidentalis trees may adjust stomatal conductance following exposure to water deficit suggesting that trees could develop a tolerance to subsequent water deficit. We speculate that in periods of extended drought, the absence of sustained year-to-year enriched δ13C values in T. occidentalis trees may thus reflect stomatal conditioning. This suggests that tree-<span class="hlt">ring</span> δ13C in T. occidentalis trees may have limited utility in drought reconstruction. Comparing the T. occidentalis δ13C data with that of other coniferous species from northern Manitoba revealed that T. occidentalis was the most δ13C-enriched species and that it portrayed the lowest δ13C sensitivity. Low correlations also were observed between species chronologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26960389','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26960389"><span id="translatedtitle">Tree-<span class="hlt">ring</span> δ13C and δ18O, leaf δ13C and wood and leaf N status demonstrate tree <span class="hlt">growth</span> strategies and predict susceptibility to disturbance.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Billings, S A; Boone, A S; Stephen, F M</p> <p>2016-05-01</p> <p>Understanding how tree <span class="hlt">growth</span> strategies may influence tree susceptibility to disturbance is an important goal, especially given projected increases in diverse ecological disturbances this century. We use <span class="hlt">growth</span> responses of tree <span class="hlt">rings</span> to climate, relationships between tree-<span class="hlt">ring</span> stable isotopic signatures of carbon (δ(13)C) and oxygen (δ(18)O), wood nitrogen concentration [N], and contemporary leaf [N] and δ(13)C values to assess potential historic drivers of tree photosynthesis in dying and apparently healthy co-occurring northern red oak (Quercus rubra L. (Fagaceae)) during a region-wide oak decline event in Arkansas, USA. Bole <span class="hlt">growth</span> of both healthy and dying trees responded negatively to drought severity (Palmer Drought Severity Index) and temperature; healthy trees exhibited a positive, but small, response to growing season precipitation. Contrary to expectations, tree-<span class="hlt">ring</span> δ(13)C did not increase with drought severity. A significantly positive relationship between tree-<span class="hlt">ring</span> δ(13)C and δ(18)O was evident in dying trees (P < 0.05) but not in healthy trees. Healthy trees' wood exhibited lower [N] than that of dying trees throughout most of their lives (P < 0.05), and we observed a significant, positive relationship (P < 0.05) in healthy trees between contemporary leaf δ(13)C and leaf N (by mass), but not in dying trees. Our work provides evidence that for plants in which strong relationships between δ(13)C and δ(18)O are not evident, δ(13)C may be governed by plant N status. The data further imply that historic photosynthesis in healthy trees was linked to N status and, perhaps, C sink strength to a greater extent than in dying trees, in which tree-<span class="hlt">ring</span> stable isotopes suggest that historic photosynthesis was governed primarily by stomatal regulation. This, in turn, suggests that assessing the relative dominance of photosynthetic capacity vs stomatal regulation as drivers of trees' C accrual may be a feasible means of predicting tree</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4980003','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4980003"><span id="translatedtitle">Climate Response of Tree Radial <span class="hlt">Growth</span> at Different Timescales in the Qinling Mountains</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Changfeng; Liu, Yu</p> <p>2016-01-01</p> <p>The analysis of the tree radial <span class="hlt">growth</span> response to climate is crucial for dendroclimatological research. However, the response relationships between tree-<span class="hlt">ring</span> indices and climatic factors at different timescales are not yet clear. In this study, the tree-<span class="hlt">ring</span> <span class="hlt">width</span> of Huashan pine (Pinus armandii) from Huashan in the Qinling Mountains, north-central China, was used to explore the response differences of tree <span class="hlt">growth</span> to climatic factors at daily, pentad (5 days), dekad (10 days) and monthly timescales. Correlation function and linear regression analysis were applied in this paper. The tree-<span class="hlt">ring</span> <span class="hlt">width</span> showed a more sensitive response to daily and pentad climatic factors. With the timescale decreasing, the absolute value of the maximum correlation coefficient between the tree-<span class="hlt">ring</span> data and precipitation increases as well as temperature (mean, minimum and maximum temperature). Compared to the other three timescales, pentad was more suitable for analysing the response of tree <span class="hlt">growth</span> to climate. Relative to the monthly climate data, the association between the tree-<span class="hlt">ring</span> data and the pentad climate data was more remarkable and accurate, and the reconstruction function based on the pentad climate was also more reliable and stable. We found that the major climatic factor limiting Huashan pine <span class="hlt">growth</span> was the precipitation of pentads 20–35 (from April 6 to June 24) rather than the well-known April–June precipitation. The pentad was also proved to be a better timescale for analysing the climate and tree <span class="hlt">growth</span> in the western and eastern Qinling Mountains. The formation of the earlywood density of Chinese pine (Pinus tabulaeformis) from Shimenshan in western Qinling was mainly affected by the maximum temperature of pentads 28–32 (from May 16 to June 9). The maximum temperature of pentads 28–33 (from May 16 to June 14) was the major factor affecting the <span class="hlt">ring</span> <span class="hlt">width</span> of Chinese pine from Shirenshan in eastern Qinling. PMID:27508933</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27508933','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27508933"><span id="translatedtitle">Climate Response of Tree Radial <span class="hlt">Growth</span> at Different Timescales in the Qinling Mountains.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Changfeng; Liu, Yu</p> <p>2016-01-01</p> <p>The analysis of the tree radial <span class="hlt">growth</span> response to climate is crucial for dendroclimatological research. However, the response relationships between tree-<span class="hlt">ring</span> indices and climatic factors at different timescales are not yet clear. In this study, the tree-<span class="hlt">ring</span> <span class="hlt">width</span> of Huashan pine (Pinus armandii) from Huashan in the Qinling Mountains, north-central China, was used to explore the response differences of tree <span class="hlt">growth</span> to climatic factors at daily, pentad (5 days), dekad (10 days) and monthly timescales. Correlation function and linear regression analysis were applied in this paper. The tree-<span class="hlt">ring</span> <span class="hlt">width</span> showed a more sensitive response to daily and pentad climatic factors. With the timescale decreasing, the absolute value of the maximum correlation coefficient between the tree-<span class="hlt">ring</span> data and precipitation increases as well as temperature (mean, minimum and maximum temperature). Compared to the other three timescales, pentad was more suitable for analysing the response of tree <span class="hlt">growth</span> to climate. Relative to the monthly climate data, the association between the tree-<span class="hlt">ring</span> data and the pentad climate data was more remarkable and accurate, and the reconstruction function based on the pentad climate was also more reliable and stable. We found that the major climatic factor limiting Huashan pine <span class="hlt">growth</span> was the precipitation of pentads 20-35 (from April 6 to June 24) rather than the well-known April-June precipitation. The pentad was also proved to be a better timescale for analysing the climate and tree <span class="hlt">growth</span> in the western and eastern Qinling Mountains. The formation of the earlywood density of Chinese pine (Pinus tabulaeformis) from Shimenshan in western Qinling was mainly affected by the maximum temperature of pentads 28-32 (from May 16 to June 9). The maximum temperature of pentads 28-33 (from May 16 to June 14) was the major factor affecting the <span class="hlt">ring</span> <span class="hlt">width</span> of Chinese pine from Shirenshan in eastern Qinling. PMID:27508933</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22384574','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22384574"><span id="translatedtitle">[Responses of Pinus sylvestris var. mongolica radial <span class="hlt">growth</span> to climate warming in Great Xing' an Mountins: a case study in Mangui].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xing-Liang; He, Xing-Yuan; Chen, Zhen-Ju; Cui, Ming-Xing; Li, Na</p> <p>2011-12-01</p> <p>Based on the theory and methodology of dendrochronology, the tree <span class="hlt">ring</span> <span class="hlt">width</span> chronology of Pinus sylvestris var. mongolica in Mangui of Great Xing' an Mountains was developed, and the relationships between the standardized tree <span class="hlt">ring</span> <span class="hlt">width</span> chronology and local climate factors (temperature and precipitation) as well as the effects of climate factors on the P. sylvestris var. mongolica radial <span class="hlt">growth</span> were analyzed. In this region, the mean monthly temperature in April-August of current year was the main factor limiting the radial <span class="hlt">growth</span>, and the increasing mean monthly temperature from April to August had negative effects to the radial <span class="hlt">growth</span>. The simulation of the variations of the radial <span class="hlt">growth</span> by the mean monthly temperature change in April-August showed that the radial <span class="hlt">growth</span> of P. sylvestris var. mongolica would present a declining trend accompanied with the warmer and drier regional climate condition. PMID:22384574</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4729093','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4729093"><span id="translatedtitle">Autosomal <span class="hlt">ring</span> chromosomes in human genetic disorders</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p><span class="hlt">Ring</span> chromosomes arise following breakage and rejoining in both chromosome arms. They are heterogeneous with variable size and genetic content and can originate from any chromosome. Phenotypes associated with <span class="hlt">ring</span> chromosomes are highly variable as apart from any deletion caused by <span class="hlt">ring</span> formation, imbalances from <span class="hlt">ring</span> instability can also occur. Of interest is <span class="hlt">ring</span> chromosome 20 which has a significant association with epilepsy with seizure onset in early childhood. Severe <span class="hlt">growth</span> deficiency without major malformations is a common finding in the <span class="hlt">ring</span> chromosome carrier. This phenotype associated with <span class="hlt">ring</span> behaviour and mitotic instability and independent of the chromosome involved has been termed the “<span class="hlt">ring</span> syndrome”. Precise genotype-phenotype correlations for <span class="hlt">ring</span> chromosomes may not be possible as influencing factors vary depending on the extent of deletion in <span class="hlt">ring</span> formation, <span class="hlt">ring</span> instability and the level of mosaicism. Although <span class="hlt">ring</span> chromosomes usually arise as de novo events, familial transmission of <span class="hlt">rings</span> from carrier to offspring has been described and prenatal diagnosis for any pregnancies should always be considered. PMID:26835370</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007epsc.conf..873G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007epsc.conf..873G"><span id="translatedtitle">Physics of planetary <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gorkavyi, N.</p> <p>2007-08-01</p> <p>It is difficult to enumerate all the surprises presented by the planetary <span class="hlt">rings</span>. The Saturnian <span class="hlt">rings</span> are stratified into thousands of ringlets and the Uranian <span class="hlt">rings</span> are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the <span class="hlt">rings</span> is jagged and the <span class="hlt">rings</span> themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical <span class="hlt">rings</span>, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian <span class="hlt">ring</span> system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary <span class="hlt">rings</span> the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the <span class="hlt">growth</span> of short-wavelength waves and large-scale structures of the Saturnian <span class="hlt">rings</span> [1]. We have shown that the formation of the existing dense Uranian <span class="hlt">rings</span> is connected with the capture of positively drifting <span class="hlt">ring</span> particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense <span class="hlt">rings</span> at the positions of satellite resonances the collective interaction between resonant particles is amplified and the <span class="hlt">rings</span> can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C <span class="hlt">ring</span> an appreciable positive ballistic particle drift caused by the erosion of the B <span class="hlt">ring</span> by micrometeorites. It is therefore natural</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4239536','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4239536"><span id="translatedtitle">Red cell distribution <span class="hlt">width</span> and nonalcoholic steatohepatitis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet</p> <p>2014-01-01</p> <p>Red cell distribution <span class="hlt">width</span> is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution <span class="hlt">width</span> levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution <span class="hlt">width</span> as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflammatory markers should also be evaluated. PMID:25473202</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750049967&hterms=pyrotechnic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpyrotechnic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750049967&hterms=pyrotechnic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpyrotechnic"><span id="translatedtitle">Optically thick line <span class="hlt">widths</span> in pyrotechnic flares</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Douda, B. E.; Exton, R. J.</p> <p>1975-01-01</p> <p>Experimentally determined sodium line <span class="hlt">widths</span> for pyrotechnic flares are compared with simple analytical, optically-thick-line-shape calculations. Three ambient pressure levels are considered (760, 150 and 30 torr) for three different flare compositions. The measured line <span class="hlt">widths</span> range from 1.3 to 481 A. The analytic procedure emphasizes the Lorentz line shape as observed under optically-thick conditions. Calculated <span class="hlt">widths</span> are in good agreement with the measured values over the entire range.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20709553','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20709553"><span id="translatedtitle"><span class="hlt">Ringing</span> wormholes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Konoplya, R.A.; Molina, C.</p> <p>2005-06-15</p> <p>We investigate the response of traversable wormholes to external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar field. The evolution of perturbations of a wormhole is similar to that of a black hole and represents damped oscillations (<span class="hlt">ringing</span>) at intermediately late times, which are suppressed by power-law tails (proportional to t{sup -2} for monopole perturbations) at asymptotically late times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012JGRE..117.0H16B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012JGRE..117.0H16B&link_type=ABSTRACT"><span id="translatedtitle">The transition from complex craters to multi-<span class="hlt">ring</span> basins on the Moon: Quantitative geometric properties from Lunar Reconnaissance Orbiter Lunar Orbiter Laser Altimeter (LOLA) data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, David M. H.; Head, James W.; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.</p> <p>2012-03-01</p> <p>The morphologic transition from complex impact craters, to peak-<span class="hlt">ring</span> basins, and to multi-<span class="hlt">ring</span> basins has been well-documented for decades. Less clear has been the morphometric characteristics of these landforms due to their large size and the lack of global high-resolution topography data. We use data from the Lunar Orbiter Laser Altimeter (LOLA) instrument onboard the Lunar Reconnaissance Orbiter (LRO) spacecraft to derive the morphometric characteristics of impact basins on the Moon, assess the trends, and interpret the processes involved in the observed morphologic transitions. We first developed a new technique for measuring and calculating the geometric/morphometric properties of impact basins on the Moon. This new method meets a number of criteria that are important for consideration in any topographic analysis of crater landforms (e.g., multiple data points, complete range of azimuths, systematic, reproducible analysis techniques, avoiding effects of post-event processes, robustness with respect to the statistical techniques). The resulting data more completely capture the azimuthal variation in topography that is characteristic of large impact structures. These new calculations extend the well-defined geometric trends for simple and complex craters out to basin-sized structures. Several new geometric trends for peak-<span class="hlt">ring</span> basins are observed. Basin depth: A factor of two reduction in the depth to diameter (d/Dr) ratio in the transition from complex craters to peak-<span class="hlt">ring</span> basins may be characterized by a steeper trend than known previously. The d/Dr ratio for peak-<span class="hlt">ring</span> basins decreases with rim-crest diameter, which may be due to a non-proportional change in excavation cavity <span class="hlt">growth</span> or scaling, as may occur in the simple to complex transition, or increased magnitude of floor uplift associated with peak-<span class="hlt">ring</span> formation. Wall height, <span class="hlt">width</span>, and slope: Wall height and <span class="hlt">width</span> increase with increasing rim-crest diameter, while wall slope decreases; decreasing ratios</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EOSTr..94R.132S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EOSTr..94R.132S"><span id="translatedtitle">Tree <span class="hlt">ring</span> records capture long-term memory in climate systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, Colin</p> <p>2013-03-01</p> <p>Measuring tree <span class="hlt">rings</span> is a mainstay technique for estimating ancient climatic conditions, with a tree's year-by-year <span class="hlt">growth</span> reflecting changes in precipitation and temperature. In some cases, paleoclimatological records compiled from tree <span class="hlt">ring</span> measurements can stretch for thousands of years. Based on recent research, climatologists have found that hydrological and other systems have long-term memory. Drawing on tree <span class="hlt">ring</span> measurements compiled from across the continental United States, Bowers et al. sought to determine whether such long-term relationships are preserved in <span class="hlt">ring</span> <span class="hlt">width</span> measurements. The authors analyzed the Hurst parameter—a measure of long-term memory—of 697 different tree <span class="hlt">ring</span> records that were collected from 10 tree species from locations across the United States. They found that though each tree species had a different mean value for its Hurst parameter, meaning that each species recorded long-term trends in the climate differently, they all fell within the range suggestive of their being able to properly represent long-term memory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820050022&hterms=radar+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dradar%2Btheory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820050022&hterms=radar+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dradar%2Btheory"><span id="translatedtitle">Theory of radio occultation by Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marouf, E. A.; Tyler, G. L.; Eshleman, V. R.</p> <p>1982-01-01</p> <p>The radio occultation technique, as applied to Saturn's <span class="hlt">rings</span>, is developed as a new method for the study of the physical properties of planetary <span class="hlt">ring</span> systems. The <span class="hlt">rings</span> are treated as a Doppler-spread radar target composed of an ensemble of discrete scatterers. The mathematical formulation of the received signal as a random-phasor-sum process is carried out following a conventional radar theory approach, providing a convenient starting point for deriving coherent signal parameters. A classical result is rederived for the equivalent refractive index of the medium. The analysis is generalized to include ringlets of arbitrary <span class="hlt">width</span> and it is shown that when the <span class="hlt">width</span> is such that two adjacent rays are differentially perturbed in phase, ray bending that causes focusing of the coherent signal may result. The diffuse component is also treated in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=286997','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=286997"><span id="translatedtitle">Effects of agaricus lilaceps fairy <span class="hlt">rings</span> on soil aggregation and microbial community structure in relation to <span class="hlt">growth</span> stimulation of western wheatgrass (pascopyrum smithii) in Eastern Montana rangeland</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Stimulation of plant productivity caused by Agaricus fairy <span class="hlt">rings</span> has been reported, but nothing is known about soil aggregation and the microbial community structure of the stimulated zone, particularly the communities that can bind to soil particles. We studied three concentric zones of Agaricus li...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174874','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174874"><span id="translatedtitle">Structural disorder and transformation in crystal <span class="hlt">growth</span>: direct observation of <span class="hlt">ring</span>-opening isomerization in a metal–organic solid solution</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jiang, Ji-Jun; He, Jian-Rong; Lü, Xing-Qiang; Wang, Da-Wei; Li, Guo-Bi; Su, Cheng-Yong</p> <p>2014-01-01</p> <p>A rare example is reported in which discrete Ag2 L 2 <span class="hlt">ring</span> and (AgL)∞ chain motifs [L = N,N′-bis(3-imidazol-1-yl-propyl)-pyromellitic diimide] co-crystallize in the same crystal lattice with varying ratios and degrees of disorder. Crystal structures obtained from representative crystals reveal compatible packing arrangements of the cyclic and polymeric isomers within the crystal lattice, which enables them to co-exist within a crystalline solid solution. A feasible pathway for transformation between the isomers is suggested via facile rotation of the coordinating imidazolyl groups. This chemical system could provide a chance for direct observation of <span class="hlt">ring</span>-opening isomerization at the crystal surface. Mass spectrometry and 1H NMR titration show a dynamic equilibrium between cyclic and oligomeric species in solution, and a potential crystallization process is suggested involving alignment of precursors directed by aromatic stacking interactions between pyromellitic diimide units, followed by <span class="hlt">ring</span>-opening isomerization at the interface between the solid and the solution. Both cyclic and oligomeric species can act as precursors, with interconversion between them being facile due to a low energy barrier for rotation of the imidazole <span class="hlt">rings</span>. Thermogravimetric analysis and variable-temperature powder X-ray diffraction indicate a transition to a different crystalline phase around 120°C, which is associated with loss of solvent from the crystal lattice. PMID:25295173</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21587453','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21587453"><span id="translatedtitle">NUCLEAR <span class="hlt">RINGS</span> IN GALAXIES-A KINEMATIC PERSPECTIVE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mazzuca, Lisa M.; Swaters, Robert A.; Veilleux, Sylvain; Knapen, Johan H.</p> <p>2011-10-01</p> <p>We combine DensePak integral field unit and TAURUS Fabry-Perot observations of 13 nuclear <span class="hlt">rings</span> to show an interconnection between the kinematic properties of the <span class="hlt">rings</span> and their resonant origin. The nuclear <span class="hlt">rings</span> have regular and symmetric kinematics, and lack strong non-circular motions. This symmetry, coupled with a direct relationship between the position angles and ellipticities of the <span class="hlt">rings</span> and those of their host galaxies, indicates that the <span class="hlt">rings</span> are in the same plane as the disk and are circular. From the rotation curves derived, we have estimated the compactness (v{sup 2}/r) up to the turnover radius, which is where the nuclear <span class="hlt">rings</span> reside. We find that there is evidence of a correlation between compactness and <span class="hlt">ring</span> <span class="hlt">width</span> and size. Radially wide <span class="hlt">rings</span> are less compact, and thus have lower mass concentration. The compactness increases as the <span class="hlt">ring</span> <span class="hlt">width</span> decreases. We also find that the nuclear <span class="hlt">ring</span> size is dependent on the bar strength, with weaker bars allowing <span class="hlt">rings</span> of any size to form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21289923','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21289923"><span id="translatedtitle">Critical comparison of Kramers' fission <span class="hlt">width</span> with the stationary <span class="hlt">width</span> from the Langevin equation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sadhukhan, Jhilam; Pal, Santanu</p> <p>2009-06-15</p> <p>It is shown that Kramers' fission <span class="hlt">width</span>, originally derived for a system with constant inertia, can be extended to systems with a deformation-dependent collective inertia, which is the case for nuclear fission. The predictions of Kramers' <span class="hlt">width</span> for systems with variable inertia are found to be in very good agreement with the stationary fission <span class="hlt">widths</span> obtained by solving the corresponding Langevin equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27154752','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27154752"><span id="translatedtitle">Microwave-assisted stereoselective approach to novel steroidal <span class="hlt">ring</span> D-fused 2-pyrazolines and an evaluation of their cell-<span class="hlt">growth</span> inhibitory effects in vitro.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mótyán, Gergő; Kovács, Ferenc; Wölfling, János; Gyovai, András; Zupkó, István; Frank, Éva</p> <p>2016-08-01</p> <p>Novel <span class="hlt">ring</span> D-condensed 2-pyrazolines in the Δ(5)-androstene series were efficiently synthesized from 16-dehydropregnenolone or its acetate with different arylhydrazines or methylhydrazine, respectively, under microwave irradiation. The reactions are assumed to occur via hydrazone intermediates, followed by intramolecular 1,4-addition leading to the fused heteroring stereoselectively with a 16α,17α-cis <span class="hlt">ring</span> junction. The synthesized compounds were subjected to in vitro pharmacological studies of their antiproliferative activities against four human breast (MCF7, T47D, MDA-MB-231 and MDA-MB-361) and three cervical (HeLa, C33A and SiHA) malignant cell lines. Flow cytometry revealed that the most potent agent elicited a cell cycle disturbance. PMID:27154752</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EGUGA..15.2347S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EGUGA..15.2347S&link_type=ABSTRACT"><span id="translatedtitle">A measuring tool for tree-<span class="hlt">rings</span> analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shumilov, Oleg; Kanatjev, Alexander; Kasatkina, Elena</p> <p>2013-04-01</p> <p>A special tool has been created for the annual tree-<span class="hlt">ring</span> <span class="hlt">widths</span> measurement and analysis. It consists of professional scanner, computer system and software. This created complex in many aspects does not yield the similar systems (LINTAB, WinDENDRO), but in comparison to manual measurement systems, it offers a number of advantages: productivity gain, possibility of archiving the results of the measurements at any stage of the processing, operator comfort. It has been developed a new software, allowing processing of samples of different types (cores, saw cuts), including those which is difficult to process, having got a complex wood structure (inhomogeneity of growing in different directions, missed, light and false <span class="hlt">rings</span> etc.). This software can analyze pictures made with optical scanners, analog or digital cameras. The complex software program was created on programming language C++, being compatible with modern operating systems like Windows X. Annual <span class="hlt">ring</span> <span class="hlt">widths</span> are measured along paths traced interactively. These paths can have any orientation and can be created so that <span class="hlt">ring</span> <span class="hlt">widths</span> are measured perpendicular to <span class="hlt">ring</span> boundaries. A graphic of <span class="hlt">ring-widths</span> in function of the year is displayed on a screen during the analysis and it can be used for visual and numerical cross-dating and comparison with other series or master-chronologies. <span class="hlt">Ring</span> <span class="hlt">widths</span> are saved to the text files in a special format, and those files are converted to the format accepted for data conservation in the International Tree-<span class="hlt">Ring</span> Data Bank. The created complex is universal in application that will allow its use for decision of the different problems in biology and ecology. With help of this complex it has been reconstructed a long-term juniper (1328-2004) and pine (1445-2005) tree-<span class="hlt">ring</span> chronologies on the base of samples collected at Kola Peninsula (northwestern Russia).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18533520','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18533520"><span id="translatedtitle">[Variations of Picea crassifolia tree-<span class="hlt">ring</span> cell structure and their implications to past climate in eastern margin of Qaidam Basin, Northwest China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yan; Liang, Er-Yuan; Shao, Xue-mei</p> <p>2008-03-01</p> <p>Tree-<span class="hlt">ring</span> samples of Picea crassifolia were collected from the upper tree-line in the eastern mountainous area of Qaidam Basin in Qinghai Province. The tree-<span class="hlt">ring</span> <span class="hlt">width</span> and the cell number and size of the tree-<span class="hlt">ring</span> were measured, and the standard chronologies for the early-wood cell number, late-wood cell number, total cell number of tree-<span class="hlt">rings</span>, maximum cell size, and minimum cell size were constructed. By using correlation analysis and the response functions between cell characteristic indices and 1970-2000 climate factors at Chaka meteorological station which was close to the sampling site, the relationships between P. crassifolia <span class="hlt">growth</span> at cell scale and climate factors were discussed. The results showed that the early-wood cell number was positively correlated to the wintertime temperature from previous October to current March, while the late-wood cell number was positively correlated to the minimum temperature in previous November and December and to the mean temperature in current July and August. Both the early-wood and the late-wood cell numbers were negatively correlated to the precipitation in July, and the early-wood cell number was positively correlated to the precipitation in May. The chronology of maximum cell size of early-wood was positively related to the precipitation in February, while that of minimum cell size of late-wood was positivelyrelated to the precipitation in August. It was concluded that the cell number and cell size could not only reveal the information of temperature change, which was recorded by tree <span class="hlt">ring</span> <span class="hlt">width</span> as well, but also provide additional information of precipitation. Since different types of tree-<span class="hlt">ring</span> indices contained different climate information, multiple aspects of climate change information could be extracted from different tree-<span class="hlt">ring</span> indices of the same species at the same site, and the cell level tree <span class="hlt">ring</span> characteristics had great potential to supply the information regarding past climate. PMID:18533520</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014QSRv...93...67L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014QSRv...93...67L"><span id="translatedtitle">Tree-<span class="hlt">ring</span> stable carbon isotope-based May-July temperature reconstruction over Nanwutai, China, for the past century and its record of 20th century warming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yu; Wang, Yanchao; Li, Qiang; Song, Huiming; Linderholm, Hans W.; Leavitt, Steven W.; Wang, Ruiyuan; An, Zhisheng</p> <p>2014-06-01</p> <p><span class="hlt">Growth</span> anomaly of trees in some regions was detected under current episode of rapid warming. This raises a dilemma for temperature reconstructions by using tree-<span class="hlt">ring</span> <span class="hlt">width</span> which is believed to be the most important proxy on inter-annual temperature reconstruction during the past millenniums. Here we employed the tree-<span class="hlt">ring</span> δ13C to reconstruct temperature variations for exploring their potential on capturing signals of rapid warming, and to test how its difference with the tree-<span class="hlt">ring</span> <span class="hlt">width</span> based reconstruction. In this study the mean May-July temperature (TM-J) was reconstructed over the past century by tree-<span class="hlt">ring</span> δ13C of Chinese pine trees growing in the Nanwutai region. The explained variance of the reconstruction was 43.3% (42.1% after adjusting the degrees of freedom). Compared to a <span class="hlt">ring-width</span> temperature reconstruction (May-July) from the same site, the tree-<span class="hlt">ring</span> δ13C-based temperature reconstruction offered two distinct advantages: 1) it captured a wider range of temperature variability, i.e., at least May-July, even over a longer part of the year, January-September; and 2) the reconstruction preserved more low-frequency climate information than that of <span class="hlt">ring</span> <span class="hlt">width</span> did. The 20th century warming was well represented in the Nanwutai tree-<span class="hlt">ring</span> δ13C temperature reconstruction, which implied that stable carbon isotope of tree <span class="hlt">rings</span> potentially represents temperature variations during historical episodes of rapid warming. A spatial correlation analysis showed that our temperature reconstruction represented climate variations over the entire Loess Plateau in north-central China. Significant positive correlations (p < 0.1) were found between the temperature reconstruction and ENSO, as well as SSTs in the Pacific and Indian Oceans. The reconstruction showed the periodicities of 22.78-, 4.16-, 3.45-3.97- and 2.04-2.83-year quasi-cycles at a 95% confidence level. Our results suggested that temperature variability in the Nanwutai region may be linked to Pacific and Indian</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930057613&hterms=dark+matter+galaxy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Ddark%2Bmatter%2Bgalaxy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930057613&hterms=dark+matter+galaxy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Ddark%2Bmatter%2Bgalaxy"><span id="translatedtitle">Hydrodynamic models of the Cartwheel <span class="hlt">ring</span> galaxy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Struck-Marcell, Curtis; Higdon, James L.</p> <p>1993-01-01</p> <p>A series of increasingly sophisticated models of the Cartwheel <span class="hlt">ring</span> galaxy is studied in order to test the collisional model for the galaxy formation and examine the star formation processes in this unique environment, using new data acquired in the last decade. The simulations provided some possible answers to a number of questions about the Cartwheel. First, an explanation for the wide spacing between inner and outer <span class="hlt">rings</span> is suggested by the simple epicyclic kinematics within the dark matter-dominated potential implied by H I rotation curve. These models and the kinematic model of Struck-Marcell and Lotan (1990) also predict that the outer <span class="hlt">ring</span> should be relatively weak, while the second inner <span class="hlt">ring</span> should be stronger, with a dense orbit-crossing region of significant <span class="hlt">width</span> bounded by sharp, caustic edges. The collisional model is given support by the agreement between the observations and the morphological and kinematic properties of the numerical simulations presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5874..385K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5874..385K"><span id="translatedtitle">Bipartite Graphs of Large Clique-<span class="hlt">Width</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korpelainen, Nicholas; Lozin, Vadim V.</p> <p></p> <p>Recently, several constructions of bipartite graphs of large clique-<span class="hlt">width</span> have been discovered in the literature. In the present paper, we propose a general framework for developing such constructions and use it to obtain new results on this topic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26327638','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26327638"><span id="translatedtitle">Pollution control enhanced spruce <span class="hlt">growth</span> in the "Black Triangle" near the Czech-Polish border.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kolář, Tomáš; Čermák, Petr; Oulehle, Filip; Trnka, Miroslav; Štěpánek, Petr; Cudlín, Pavel; Hruška, Jakub; Büntgen, Ulf; Rybníček, Michal</p> <p>2015-12-15</p> <p>Norway spruce (Picea abies (L.) Karst.) stands in certain areas of Central Europe have experienced substantial dieback since the 1970s. Understanding the reasons for this decline and reexamining the response of forests to acid deposition reduction remains challenging because of a lack of long and well-replicated tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies. Here, spruce from a subalpine area heavily affected by acid deposition (from both sulfur and nitrogen compounds) is evaluated. Tree-<span class="hlt">ring</span> <span class="hlt">width</span> measurements from 98 trees between 1000 and 1350m above sea level (a.s.l.) reflected significant May-July temperature signals. Since the 1970s, acid deposition has reduced the <span class="hlt">growth</span>-climate relationship. Efficient pollution control together with a warmer but not drier climate most likely caused the increased <span class="hlt">growth</span> of spruce stands in this region, the so-called "Black Triangle," in the 1990s. PMID:26327638</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1014874','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1014874"><span id="translatedtitle">Asymmetric dipolar <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prosandeev, Sergey A.; Ponomareva, Inna V.; Kornev, Igor A.; Bellaiche, Laurent M.</p> <p>2010-11-16</p> <p>A device having a dipolar <span class="hlt">ring</span> surrounding an interior region that is disposed asymmetrically on the <span class="hlt">ring</span>. The dipolar <span class="hlt">ring</span> generates a toroidal moment switchable between at least two stable states by a homogeneous field applied to the dipolar <span class="hlt">ring</span> in the plane of the <span class="hlt">ring</span>. The <span class="hlt">ring</span> may be made of ferroelectric or magnetic material. In the former case, the homogeneous field is an electric field and in the latter case, the homogeneous field is a magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24483064','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24483064"><span id="translatedtitle">[Effects of elevated ozone on Pinus armandii <span class="hlt">growth</span>: a simulation study with open-top chamber].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Chang-Fu; Liu, Chen; He, Xing-Yuan; Ruan, Ya-Nan; Xu, Sheng; Chen, Zhen-Ju; Peng, Jun-Jie; Li, Teng</p> <p>2013-10-01</p> <p>By using open-top chamber (OTC) and the techniques of dendrochronology, this paper studied the <span class="hlt">growth</span> of Pinus armandii under elevated ozone, and explored the evolution dynamics and adaptation mechanisms of typical forest ecosystems to ozone enrichment. Elevated ozone inhibited the stem <span class="hlt">growth</span> of P. armandii significantly, with the annual <span class="hlt">growth</span> of the stem length and diameter reduced by 35.0% and 12.9%, respectively. The annual <span class="hlt">growth</span> of tree-<span class="hlt">ring</span> <span class="hlt">width</span> and the annual <span class="hlt">ring</span> cells number decreased by 11.5% and 54.1%, respectively, but no significant change was observed in the diameter of tracheid. At regional scale, the fluctuation of ozone concentration showed significant correlation with the variation of local vegetation <span class="hlt">growth</span> (NDVI). PMID:24483064</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4488S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4488S&link_type=ABSTRACT"><span id="translatedtitle">The climate-isotope relationship of tree-<span class="hlt">rings</span> at temperate, high-altitude and high-latitude sites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saurer, Matthias; Kress, Anne; Sidorova, Olga; Siegwolf, Rolf</p> <p>2010-05-01</p> <p>Tree-<span class="hlt">ring-width</span> and latewood density provide climate information particularly at extreme sites where <span class="hlt">growth</span> is limited by a single factor. It is not clear, however, if this general principle also holds for stable carbon isotope (δ13C) or oxygen isotope (δ18O) variations. With increasing number of isotope studies and developing isotopic networks (ISONET, MILLENNIUM), the influence of site conditions on the climate-isotope relationship can now be systemically investigated. Our studies with trees growing in Europe and Siberia indicate the following: (1) Significant climate-isotope relationship are found for temperate regions where neither temperature nor precipitation are strongly limiting <span class="hlt">growth</span> (Saurer et al. 2008) (2) The climate signal does not depend as much on site conditions as it does for tree-<span class="hlt">ring</span> <span class="hlt">width</span> and latewood density (3) A particularly strong carbon isotope climate signal reflecting drought is found for an Alpine larch chronology (Kress et al. 2009) (4) Isotopes at high-latitude Siberian sites contain a mixed temperature-precipitation signal (Sidorova et al. 2009). Overall, we can state that stable isotopes in tree-<span class="hlt">rings</span> provide complimentary information to tree-<span class="hlt">ring</span> <span class="hlt">width</span> and density and extend the geographical range as well as the derived climate parameters significantly. Kress, A., Saurer, M., Siegwolf, R.T.W., Frank, D.C., Esper, J. and Bugmann, H.: A 350-year drought reconstruction from Alpine tree-<span class="hlt">ring</span> stable isotopes. Global Biogeochemical Cycles, in press Saurer, M., Cherubini, P., Reynolds-Henne, C. E., Treydte, K. S., Anderson, W. T., and Siegwolf, R. T. W.: An investigation of the common signal in tree <span class="hlt">ring</span> stable isotope chronologies at temperate sites, Journal of Geophysical Research-Biogeosciences, 113, 10.1029/2008jg000689, 2008. Sidorova, O. V., Siegwolf, R. T. W., Saurer, M., Naurzbaev, M. M., Shashkin, A. V., and Vaganov, E. A.: Spatial patterns of climatic changes in the Eurasian north reflected in Siberian larch tree-<span class="hlt">ring</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvB..69n4421C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvB..69n4421C"><span id="translatedtitle">Magnetic configurations in 160 520-nm-diameter ferromagnetic <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Castaño, F. J.; Ross, C. A.; Eilez, A.; Jung, W.; Frandsen, C.</p> <p>2004-04-01</p> <p>The remanent states and hysteretic behavior of thin-film magnetic <span class="hlt">rings</span> has been investigated experimentally and by micromagnetic modeling. <span class="hlt">Rings</span> of diameters 160 520 nm, made from Co using lift-off processing, show three distinct remanent states: a vortex state, an “onion” state with two head-on walls, and a “twisted” state containing a 360° wall. The range of stability of these states varies with <span class="hlt">ring</span> geometry, with smaller <span class="hlt">width</span> <span class="hlt">rings</span> showing higher switching fields and greater variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010048660&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010048660&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Saturn's Spectacular <span class="hlt">Ring</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)</p> <p>2001-01-01</p> <p>Saturn's beautiful <span class="hlt">rings</span> have fascinated astronomers since they were first observed by Galileo in 1610. The main <span class="hlt">rings</span> consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The <span class="hlt">ring</span> disk is exceptionally thin - the typical local thickness of the bright <span class="hlt">rings</span> is tens of meters, whereas the diameter of the main <span class="hlt">rings</span> is 250,000 km! The main <span class="hlt">rings</span> exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main <span class="hlt">rings</span> lie tenuous dust <span class="hlt">rings</span>, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of <span class="hlt">ring</span>-moon interactions, recent advances in our understanding of various aspects of the <span class="hlt">rings</span> obtained from observations taken during 1995 when the <span class="hlt">rings</span> appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17..686S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17..686S&link_type=ABSTRACT"><span id="translatedtitle">Salix polaris <span class="hlt">growth</span> responses to active layer detachment and solifluction processes in High Arctic.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siekacz, Liliana</p> <p>2015-04-01</p> <p>The work is dedicated to demonstrate the potential of Salix polaris grow properties in the dendrogemorphologic image, analyzing periglacially induced slope processes in the high Arctic.. Observed anatomical and morphological plants responses to solifluction and active layer detachment processes are presented qualitatively and quantitatively as a summary of presented features frequency. The results are discussed against the background of the other research results in this field. The investigations was performed in Ebba valley, in the vicinity of Petunia Bay, northernmost part of Billefjorden in central Spitsbergen (Svalbard). Environmental conditions are characterized by annual precipitation sum lower than 200 mm (Hagen et al.,1993) and average summer temperature of about 5°C, with maximum daily temperatures rarely exceeding 10°C (Rachlewicz, 2009). Collected shrub material was prepared according to the methods presented by Schweingruber and Poschlod (2005). Thin (approx. 15-20μm) sections of the whole cross-section were prepared with a sledge microtome, stained with Safranine and Astra blue and finally permanently fixed on microslides with Canada balsam and dried. Snapshots were taken partially for each cross-section with digital camera (ColorView III, Olympus) connected to a microscope (Olympus BX41) and merged into one, high resolution image. After all, <span class="hlt">ring</span> <span class="hlt">widths</span> were measured in 3-4 radii in every single cross-section using ImageJ software. Analyzed plants revealed extremely harsh environmental conditions of their <span class="hlt">growth</span>. Buchwał et al. (2013) provided quantitative data concerning missing <span class="hlt">rings</span> and partially missing <span class="hlt">rings</span> in shrubs growing on Ebba valley floor. Mean <span class="hlt">ring</span> <span class="hlt">width</span> at the level of 79μm represents one of the smallest values of yearly <span class="hlt">growth</span> ever noted. The share of missing <span class="hlt">rings</span> and partially missing <span class="hlt">rings</span> was 11,2% and 13,6% respectively. Plants growing on Ebba valley slope indicate almost twice smaller values of <span class="hlt">ring</span> <span class="hlt">width</span> (41μm), and higher</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4047095','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4047095"><span id="translatedtitle">C3HC4-Type <span class="hlt">RING</span> Finger Protein NbZFP1 Is Involved in <span class="hlt">Growth</span> and Fruit Development in Nicotiana benthamiana</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Wenxian; Cheng, Zhiwei; Liu, Mengjie; Yang, Xiufen; Qiu, Dewen</p> <p>2014-01-01</p> <p>C3HC4-type <span class="hlt">RING</span> finger proteins constitute a large family in the plant kingdom and play important roles in various physiological processes of plant life. In this study, a C3HC4-type zinc finger gene was isolated from Nicotiana benthamiana. Sequence analysis indicated that the gene encodes a 24-kDa protein with 191 amino acids containing one typical C3HC4-type zinc finger domain; this gene was named NbZFP1. Transient expression of pGDG-NbZFP1 demonstrated that NbZFP1 was localized to the chloroplast, especially in the chloroplasts of cells surrounding leaf stomata. Virus-induced gene silencing (VIGS) analysis indicated that silencing of NbZFP1 hampered fruit development, although the height of the plants was normal. An overexpression construct was then designed and transferred into Nicotiana benthamiana, and PCR and Southern blot showed that the NbZFP1 gene was successfully integrated into the Nicotiana benthamiana genome. The transgenic lines showed typical compactness, with a short internode length and sturdy stems. This is the first report describing the function of a C3HC4-type <span class="hlt">RING</span> finger protein in tobacco. PMID:24901716</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004APS..MARW37008R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..MARW37008R"><span id="translatedtitle">Polarization Transitions in Quantum <span class="hlt">Ring</span> Arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roostaei, Bahman; Mullen, Kieran</p> <p>2004-03-01</p> <p>We calculate the zero temperature electrostatic properties of charged one and two dimensional arrays of <span class="hlt">rings</span>, in the classical and quantum limits. Each <span class="hlt">ring</span> is assumed to be an ideal <span class="hlt">ring</span> of negligible <span class="hlt">width</span>, with exactly one electron on the <span class="hlt">ring</span> that interacts only with nearest neighbor <span class="hlt">rings</span>. In the classical limit we find that if the electron is treated as a point particle, the 1D array of <span class="hlt">rings</span> can be mapped to an Ising antiferromagnet, while the 2D array groundstate is a four-fold degenerate ``stripe" phase. In contrast, if we treat the electrical charge as a continuous fluid, the distribution will not spontaneously break symmetry, but will develop a charge distribution reflecting the symmetry of the array. In the quantum limit, the competition between the kinetic energy and Coulomb energy allows for a transition between unpolarized and polarized states as a function of the <span class="hlt">ring</span> parameters. This allows for a new class of polarizable materials whose transitions are based on geometry, rather than a structural transition in a unit cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMGC21C0888P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMGC21C0888P"><span id="translatedtitle">Isotope variability in larch tree <span class="hlt">rings</span> of Siberia: climate and ecology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panyushkina, I. P.; Knorre, A.; Leavitt, S. W.; Kirdyanov, A.; Grachev, A.; Brukhanova, M.; Vaganov, E. A.</p> <p>2010-12-01</p> <p>Paleoclimate reconstructions from tree-<span class="hlt">ring</span> <span class="hlt">widths</span> and maximum wood density are most successful in localities with extreme climates for particular tree species that are most responsive. Climate proxy records from other, less conventional, tree-<span class="hlt">ring</span> parameters have been rapidly increasing over the last decade. We assembled a unique dataset of carbon and oxygen isotope ratios of larch tree <span class="hlt">rings</span> from the northern and southern tree-lines of Siberia, variously sub-sampled and analyzed (whole wood and cellulose & annual and 5-year sequences from individual trees and pooled). Larch samples from the north in Taymyr (Larix gmelinii Rupr.) published by Sidorova et al. (2010) and from the south collected in Khakasia (Larix sibirica Ledeb.) both came from highly temperate continental climates exhibiting similar amounts of precipitation and observed temperature trends. However, the sites differ because temperature is the dominant factor limiting radial tree <span class="hlt">growth</span> in the north, whereas precipitation is the dominant limiting factor in the south. Climatic signals documented in the chronologies of tree-<span class="hlt">ring</span> <span class="hlt">widths</span>, wood density, and stable carbon and oxygen isotopes were compared from 1896 to 2005 and interpreted based on site ecology and larch physiology. We found a wide range of climatic responses in the variability of isotopic ratios, which suggest influence by combined interaction of precipitation and temperature changes rather than either climate factor alone. We discuss the improvement in our understanding of climatic mechanisms that control isotope compositions and tree <span class="hlt">growth</span> in boreal forests. At certain locations where tree-<span class="hlt">ring</span> <span class="hlt">widths</span> are less sensitive to climate factors, isotope analysis may have greater value to successful climate modeling. It seems crucial to measure both isotopes (C and O) in tree <span class="hlt">rings</span> and to incorporate these mechanisms properly in developing reliable climate predictors. It is noteworthy that despite the identified differences in climatic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JESS..120..713R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JESS..120..713R"><span id="translatedtitle">Tree-<span class="hlt">ring</span> variation in teak ( Tectona grandis L.) from Allapalli, Maharashtra in relation to moisture and Palmer Drought Severity Index, India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ram, Somaru; Borgaonkar, H. P.; Munot, A. A.; Sikder, A. B.</p> <p>2011-08-01</p> <p>We developed a <span class="hlt">ring-width</span> chronology of teak ( Tectona grandis L.) from a moisture stressed area in Maharashtra, India. Bootstrapped correlation analysis indicated that moisture index (MI) and Palmer Drought Severity Index (PDSI) showed better performance rather than same year rainfall over the region. Tree-<span class="hlt">ring</span> variations were most correlated positively with PDSI during different seasons compared with MI. Significant strong positive correlation with MI, and negative association with temperature and potential evapotranspiration (PET) were found during previous and current year post-monsoon (ON). This study shows that the moisture availability during the post-monsoon of the previous year has a significant role in the development of annual <span class="hlt">growth</span> <span class="hlt">rings</span>. The reconstructed previous year post-monsoon (-ON) moisture index for the period 1866-1996 indicates 3.5 and 29.3 years periodicities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4861Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4861Y"><span id="translatedtitle">The ralationship between the Tamarix spp. <span class="hlt">growth</span> and lake level change in the Bosten Lake,northwest China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Mao; Hou, JiaWen</p> <p>2015-04-01</p> <p>Dendrochronology methods are used to analyze the characteristics of Tamarix spp. <span class="hlt">growth</span> in Bosten Lake. Based on the long-term annual and monthly data of lake level, this paper models the relationship between <span class="hlt">ring</span> <span class="hlt">width</span> of Tamarix spp. and lake level change. The sensitivity index is applied to determine the rational change range of lake level for protecting the Tamarix spp. <span class="hlt">growth</span>. The results show that :( 1) the annual change of lake level in Bosten Lake has tree evident stages from 1955 to 2012. The monthly change of lake level has two peak values and the seasonal change is not significant; (2) the average value of radical <span class="hlt">width</span> of Tamarix spp. is 3.39mm. With the increment of Tamarix spp. annual <span class="hlt">growth</span> , the average radical <span class="hlt">width</span> has a decreasing trend, which is similar to the annual change trend of lake level in the same years ;( 3) the response of the radical <span class="hlt">width</span> of Tamarix spp. to annual change of lake level is sensitive significantly. When the lake level is 1045.66m, the Sk value of radical <span class="hlt">width</span> of Tamarix spp. appears minimum .when the lake level is up to1046.27m, the Sk value is maximum. Thus the sensitivity level of radical <span class="hlt">width</span> of Tamarix spp. is 1045.66- 1046.27m which could be regarded as the rational lake level change range for protecting the Tamarix spp. <span class="hlt">growth</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..304K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..304K"><span id="translatedtitle">Tree <span class="hlt">rings</span>, solar radiation and ice cover of the Barents sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasatkina, Elena; Shumilov, Oleg; Timonen, Mauri; Kanatjev, Alexandr</p> <p>2015-04-01</p> <p>Intercomparisons of the Kola Peninsula tree-<span class="hlt">ring</span> records, ice cover of the Barents sea and sea and surface temperatures have been made. Tree-<span class="hlt">ring</span> series over the last 100 years showed a highly significant correlation with the sea surface temperatures and ice cover (r=-0.57, p<0.05). It should be noted that the correlation between the tree-<span class="hlt">ring</span> <span class="hlt">widths</span> and local temperatures was not so high. We suppose that a possible reason seems to be the prevailing influence of solar irradiance and their UV components on tree <span class="hlt">growth</span> in the Kola North. It is known that solar variability and fluctuations of solar irradiance in the UV band of the spectrum has increased over the last decades. In addition, there are frequent cases of total ozone content depletions (or so-called ozone mini-holes) resulting in increased UV-B. The recent studies demonstrate that many boreal and subarctic plants have increased susceptibility to UV-B radiation. An indirect confirmation of the hypothesis proposed is a close relationship between solar total irradiance and global sea surface temperature (Reid, 2000). The results of spectral MTM-analysis also revealed periodicities close to the solar cycles in the ice cover and tree-<span class="hlt">ring</span> records. These results confirm the above-mentioned interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864815','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864815"><span id="translatedtitle">Stirling engine piston <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Howarth, Roy B.</p> <p>1983-01-01</p> <p>A piston <span class="hlt">ring</span> design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the <span class="hlt">ring</span>'s surface and thereby allowing the contact pressure on the <span class="hlt">ring</span> to be predetermined through the use of a preloaded expander <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27326928','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27326928"><span id="translatedtitle">Actin <span class="hlt">Rings</span> of Power.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schwayer, Cornelia; Sikora, Mateusz; Slováková, Jana; Kardos, Roland; Heisenberg, Carl-Philipp</p> <p>2016-06-20</p> <p>Circular or <span class="hlt">ring</span>-like actin structures play important roles in various developmental and physiological processes. Commonly, these <span class="hlt">rings</span> are composed of actin filaments and myosin motors (actomyosin) that, upon activation, trigger <span class="hlt">ring</span> constriction. Actomyosin <span class="hlt">ring</span> constriction, in turn, has been implicated in key cellular processes ranging from cytokinesis to wound closure. Non-constricting actin <span class="hlt">ring</span>-like structures also form at cell-cell contacts, where they exert a stabilizing function. Here, we review recent studies on the formation and function of actin <span class="hlt">ring</span>-like structures in various morphogenetic processes, shedding light on how those different <span class="hlt">rings</span> have been adapted to fulfill their specific roles. PMID:27326928</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/957162','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/957162"><span id="translatedtitle">New Dust Belts of Uranus: One <span class="hlt">Ring</span>, Two <span class="hlt">Ring</span>, Red <span class="hlt">Ring</span>, Blue <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R</p> <p>2006-02-02</p> <p>We compare near-infrared observations of the recently discovered outer <span class="hlt">rings</span> of Uranus with HST results. We find that the inner <span class="hlt">ring</span>, R/2003 U 2, is red, whereas the outer <span class="hlt">ring</span>, R/2003 U 1, is very blue. Blue is an unusual color for <span class="hlt">rings</span>; Saturn's enigmatic E <span class="hlt">ring</span> is the only other known example. By analogy to the E <span class="hlt">ring</span>, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4880555','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4880555"><span id="translatedtitle">Biological Basis of Tree-<span class="hlt">Ring</span> Formation: A Crash Course</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rathgeber, Cyrille B. K.; Cuny, Henri E.; Fonti, Patrick</p> <p>2016-01-01</p> <p>Wood is of crucial importance for man and biosphere. In this mini review, we present the fundamental processes involved in tree-<span class="hlt">ring</span> formation and intra-annual dynamics of cambial activity, along with the influences of the environmental factors. During wood formation, new xylem cells produced by the cambium are undergoing profound transformations, passing through successive differentiation stages, which enable them to perform their functions in trees. Xylem cell formation can be divided in five major phases: (1) the division of a cambial mother cell that creates a new cell; (2) the enlargement of this newly formed cell; (3) the deposition of its secondary wall; (4) the lignification of its cell wall; and finally, (5) its programmed cell death. In most regions of the world cambial activity follows a seasonal cycle. At the beginning of the growing season, when temperature increases, the cambium resumes activity, producing new xylem cells. These cells are disposed along radial files, and start their differentiation program according to their birth date, creating typical developmental strips in the forming xylem. The <span class="hlt">width</span> of these strips smoothly changes along the growing season. Finally, when climatic conditions deteriorate (temperature or water availability in particular), cambial activity stops, soon followed by cell enlargement, and later on by secondary wall deposition. Without a clear understanding of the xylem formation process, it is not possible to comprehend how annual <span class="hlt">growth</span> <span class="hlt">rings</span> and typical wood structures are formed, recording normal seasonal variations of the environment as well as extreme climatic events. PMID:27303426</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1478P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1478P"><span id="translatedtitle">Climate variability of Late Pleistocene deglaciation in the North American midcontinent derived from tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panyushkina, Irina P.; Livina, Valerie N.; Leavitt, Steve W.; Mode, William N.</p> <p>2016-04-01</p> <p>High-resolution climatic proxies, such as tree <span class="hlt">rings</span> spanning millennia, have excellent potential to describe high- and low-frequency variability of climate. In practice, however, although the number of Holocene millennium-length tree-<span class="hlt">ring</span> records is still rather limited, they are especially rare for the Late Pleistocene warming period following the Last Glacial Maximum. Furthermore, detection of climatic variability in tree-<span class="hlt">ring</span> data is hindered due to intricate methodology of chronology development that transforms changes in tree geometry and a variety of environmental responses of tree <span class="hlt">growth</span> to a climatic signal. Following meticulous derivation of a new tree-<span class="hlt">ring</span> chronology, we propose a novel approach to analyze annual, decadal, multi-decadal and centennial climate-related variability of floating tree <span class="hlt">rings</span> dated back near the end of the Pleistocene. We have developed a 1400-year tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronology of spruce from the Green Bay area (Wisconsin) dated from 14.5 ka to 13.1ka cal BP. This new North American midcontinent record is composed of 10 overlapped site chronologies and has two short gaps filled with linear interpolation. The Green Bay chronology covers most of the warm and moist Bølling-Allerød interstadial (14.7 ka -12.7 ka BP). Within the Bølling-Allerød interstadial, there were several abrupt and brief cooling excursions such as the Older Dryas with full-glacial-like temperature conditions. We have applied tipping point analysis to detect the changes of climate-system states during these turbulent times and obtained early warning signals in the tree-<span class="hlt">ring</span> variance. The analysis detected four short-term bifurcations dated ca. 14,450 cal BP, 14,000 cal BP, 13,750-13,600 cal BP and 13,180-13,100 cal BP. The bifurcation events of the tree-<span class="hlt">ring</span> record correspond well to the abrupt and short cooling temperature excursions of the Bølling-Allerød interstadial documented in δ18O and Ca of GRIP ice-core records, and the Laurentide ice sheet dynamics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMPP31A1844P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMPP31A1844P"><span id="translatedtitle">Climate variability at the onset of the Younger Dryas as reflected in annually resolved tree-<span class="hlt">ring</span> stable isotope chronologies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pieper, H.; Helle, G.; Brauer, A.; Kaiser, K. F.; Miramont, C.</p> <p>2013-12-01</p> <p>The Younger Dryas interval during the Last Glacial Termination was an abrupt return to glacial-like conditions punctuating the transition to a warmer, interglacial climate. Despite recent advances in the layer counting of ice-core records of the termination, the timing and length of the Younger Dryas remain controversial. Late Glacial and early Holocene tree-<span class="hlt">ring</span> chronologies are rare, however, they contain valuable information about past environmental conditions at annual time resolution. Changes in tree-<span class="hlt">ring</span> <span class="hlt">growth</span> rates can be related to past climate anomalies and changes in the carbon and oxygen isotope composition of tree-<span class="hlt">ring</span> cellulose reflect atmospheric and hydrospheric changes. We are investigating a 860-year (13200 - 12340 cal BP) dated dendrochronological record of Late Glacial and Early Holocene chronologies of scots pine (Pinus sylvestris L.) from subfossil tree remnants from Barbiers River (Moyenne Durance, Southern French Alps), as well as from Swiss (Dättnau, Landikon and Gänziloh) sites. Dendro-ecological parameters, such as <span class="hlt">ring</span> <span class="hlt">width</span> and stable isotope variations (δ 13C und δ 18O) are used to infer past environmental conditions. We will present our first carbon and oxygen isotope records from tree <span class="hlt">rings</span> reflecting the environmental changes at the Alleröd/Younger Dryas -transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950007522','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950007522"><span id="translatedtitle">The Stokes line <span class="hlt">width</span> and uncertainty relations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nikishov, A. I.; Ritus, V. I.</p> <p>1994-01-01</p> <p>For a function given by contour integral the two types (conventions) of asymptotic representations are considered: the usual representation by asymptotic series in inverse powers of large parameters and the special division of contour integral in contributions of high and low saddle points. It is shown that the <span class="hlt">width</span> of the recessive term formation zone (Stokes strip) in the second convention is determined by uncertainty relation and is much less than the zone <span class="hlt">width</span> in the first convention. The reasons of such a difference is clarified. The results of the work are useful for understanding of formation region of the exponentially small process arising on the background of the strong one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880038675&hterms=Infrared+Absorption+Lines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DInfrared%2BAbsorption%2BLines','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880038675&hterms=Infrared+Absorption+Lines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DInfrared%2BAbsorption%2BLines"><span id="translatedtitle">Infrared line <span class="hlt">widths</span> at planetary atmospheric temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Varanasi, Prasad</p> <p>1988-01-01</p> <p>Recent theoretical models and measurements of the variation of collision-broadened line <span class="hlt">width</span> with temperature in the infrared are discussed for temperatures relevant to planetary atmospheres. The present review is restricted to lines broadened by H2, N2, O2, CO2, and He, the lines formed in the atmospheres of Jupiter, Saturn, Uranus, and Neptune. The design for a low-temperature absorption cell consisting of a nickel-coated copper tube is described. The lack of an adequate theoretical model for variation of the collision-broadened line <span class="hlt">width</span> with temperature in terms of the molecular constants of the colliding partners is pointed out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25769337','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25769337"><span id="translatedtitle">Biophysical modelling of intra-<span class="hlt">ring</span> variations in tracheid features and wood density of Pinus pinaster trees exposed to seasonal droughts.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilkinson, Sarah; Ogée, Jérôme; Domec, Jean-Christophe; Rayment, Mark; Wingate, Lisa</p> <p>2015-03-01</p> <p>Process-based models that link seasonally varying environmental signals to morphological features within tree <span class="hlt">rings</span> are essential tools to predict tree <span class="hlt">growth</span> response and commercially important wood quality traits under future climate scenarios. This study evaluated model portrayal of radial <span class="hlt">growth</span> and wood anatomy observations within a mature maritime pine (Pinus pinaster (L.) Aït.) stand exposed to seasonal droughts. Intra-annual variations in tracheid anatomy and wood density were identified through image analysis and X-ray densitometry on stem cores covering the <span class="hlt">growth</span> period 1999-2010. A cambial <span class="hlt">growth</span> model was integrated with modelled plant water status and sugar availability from the soil-plant-atmosphere transfer model MuSICA to generate estimates of cell number, cell volume, cell mass and wood density on a weekly time step. The model successfully predicted inter-annual variations in cell number, <span class="hlt">ring</span> <span class="hlt">width</span> and maximum wood density. The model was also able to predict the occurrence of special anatomical features such as intra-annual density fluctuations (IADFs) in <span class="hlt">growth</span> <span class="hlt">rings</span>. Since cell wall thickness remained surprisingly constant within and between <span class="hlt">growth</span> <span class="hlt">rings</span>, variations in wood density were primarily the result of variations in lumen diameter, both in the model and anatomical data. In the model, changes in plant water status were identified as the main driver of the IADFs through a direct effect on cell volume. The anatomy data also revealed that a trade-off existed between hydraulic safety and hydraulic efficiency. Although a simplified description of cambial physiology is presented, this integrated modelling approach shows potential value for identifying universal patterns of tree-<span class="hlt">ring</span> <span class="hlt">growth</span> and anatomical features over a broad climatic gradient. PMID:25769337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP43B1485D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP43B1485D"><span id="translatedtitle">Seasonal Climate Signals in Multiple Tree-<span class="hlt">Ring</span> Parameters: A Pilot Study of Pinus ponderosa in the Columbia River Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dannenberg, M.; Wise, E. K.; Keung, J. H.</p> <p>2014-12-01</p> <p>Proxy-based reconstructions of past climate have played an integral role in assessments of historical climate change, and tree-<span class="hlt">ring</span> <span class="hlt">widths</span> (TRW) have a long history of use in this paleoclimate research due to their annual resolution, widespread availability, and sensitivity of <span class="hlt">growth</span> processes to variation in temperature and water availability. Increasingly, studies have shown that additional tree-<span class="hlt">ring</span> metrics—including earlywood and latewood <span class="hlt">widths</span> (EW and LW, respectively), maximum latewood density, and the intensity of reflected blue light from latewood (BI)—can provide additional information on seasonal climatic variability that is not present in TRW alone due to different processes that affect <span class="hlt">growth</span> in different parts of the growing season. Studies of these additional tree-<span class="hlt">ring</span> metrics highlight their utility in climate reconstructions, but to date they have mostly been limited to a few tree species and regions. Here, we extend the range of previous studies on alternative tree-<span class="hlt">ring</span> metrics by evaluating the seasonal climate signals in TRW, EW, LW, and BI of Pinus ponderosa at six semiarid sites surrounding the Columbia River basin in the U.S. Pacific Northwest (PNW). Cores from each site were cross-dated and EW, LW, and TRW were measured using standard dendrochronological procedures. BI was obtained using a high-resolution flatbed scanner and CooRecorder software. To evaluate the unique climate processes and seasonalities contributing to different dendrochronological metrics, monthly temperature and precipitation from each site were obtained from the PRISM climate model and were correlated with each of the tree-<span class="hlt">ring</span> metrics using the MATLAB program SEASCORR. We also evaluate the potential of using multiple tree-<span class="hlt">ring</span> metrics (rather than a single proxy) in reconstructions of precipitation in the PNW. Initial results suggest that 1) tree <span class="hlt">growth</span> at each site is water-limited but with substantial differences among the sites in the strength and seasonality of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/1016189','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/1016189"><span id="translatedtitle">Recent <span class="hlt">growth</span> of conifer species of western North America: Assessing spatial patterns of radial <span class="hlt">growth</span> trends</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McKenzie, D.; Hessl, Amy E.; Peterson, D.L.</p> <p>2001-01-01</p> <p>We explored spatial patterns of low-frequency variability in radial tree <span class="hlt">growth</span> among western North American conifer species and identified predictors of the variability in these patterns. Using 185 sites from the International Tree-<span class="hlt">Ring</span> Data Bank, each of which contained 10a??60 raw <span class="hlt">ring-width</span> series, we rebuilt two chronologies for each site, using two conservative methods designed to retain any low-frequency variability associated with recent environmental change. We used factor analysis to identify regional low-frequency patterns in site chronologies and estimated the slope of the <span class="hlt">growth</span> trend since 1850 at each site from a combination of linear regression and time-series techniques. This slope was the response variable in a regression-tree model to predict the effects of environmental gradients and species-level differences on <span class="hlt">growth</span> trends. <span class="hlt">Growth</span> patterns at 27 sites from the American Southwest were consistent with quasi-periodic patterns of drought. Either 12 or 32 of the 185 sites demonstrated patterns of increasing <span class="hlt">growth</span> between 1850 and 1980 A.D., depending on the standardization technique used. Pronounced <span class="hlt">growth</span> increases were associated with high-elevation sites (above 3000 m) and high-latitude sites in maritime climates. Future research focused on these high-elevation and high-latitude sites should address the precise mechanisms responsible for increased 20th century <span class="hlt">growth</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IJBm...59.1127C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IJBm...59.1127C&link_type=ABSTRACT"><span id="translatedtitle">Do variations in leaf phenology affect radial <span class="hlt">growth</span> variations in Fagus sylvatica?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Čufar, Katarina; De Luis, Martin; Prislan, Peter; Gričar, Jožica; Črepinšek, Zalika; Merela, Maks; Kajfež-Bogataj, Lučka</p> <p>2015-08-01</p> <p>We used a dendrochronological and leaf phenology network of European beech ( Fagus sylvatica) in Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, for the period 1955-2007 to test whether year to year variations in leaf unfolding and canopy duration (i.e. time between leaf unfolding and colouring) influence radial <span class="hlt">growth</span> (annual xylem production and tree <span class="hlt">ring</span> <span class="hlt">widths</span>) and if such influences are more pronounced at higher altitudes. We showed that variability in leaf phenology has no significant effect on variations in radial <span class="hlt">growth</span>. The results are consistent in the entire region, irrespective of the climatic regime or altitude, although previous studies have shown that leaf phenology and tree <span class="hlt">ring</span> variation depend on altitude. The lack of relationship between year to year variability in leaf phenology and radial <span class="hlt">growth</span> may suggest that earlier leaf unfolding—as observed in a previous study—probably does not cause increased tree <span class="hlt">growth</span> rates in beech in Slovenia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol2/pdf/CFR-2010-title7-vol2-sec29-1085.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol2/pdf/CFR-2010-title7-vol2-sec29-1085.pdf"><span id="translatedtitle">7 CFR 29.1085 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 7 Agriculture 2 2010-01-01 2010-01-01 false <span class="hlt">Width</span>. 29.1085 Section 29.1085 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ) (2 ) Waste tolerance (2 ) (2 ) (2 ) 1 Expressed in inches. 2 Expressed in percentage. elements...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title7-vol2/pdf/CFR-2014-title7-vol2-sec29-1085.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title7-vol2/pdf/CFR-2014-title7-vol2-sec29-1085.pdf"><span id="translatedtitle">7 CFR 29.1085 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... 7 Agriculture 2 2014-01-01 2014-01-01 false <span class="hlt">Width</span>. 29.1085 Section 29.1085 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ) (2 ) Waste tolerance (2 ) (2 ) (2 ) 1 Expressed in inches. 2 Expressed in percentage. elements...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol2/pdf/CFR-2011-title7-vol2-sec29-1085.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol2/pdf/CFR-2011-title7-vol2-sec29-1085.pdf"><span id="translatedtitle">7 CFR 29.1085 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... 7 Agriculture 2 2011-01-01 2011-01-01 false <span class="hlt">Width</span>. 29.1085 Section 29.1085 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ) (2 ) Waste tolerance (2 ) (2 ) (2 ) 1 Expressed in inches. 2 Expressed in percentage. elements...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title7-vol2/pdf/CFR-2013-title7-vol2-sec29-1085.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title7-vol2/pdf/CFR-2013-title7-vol2-sec29-1085.pdf"><span id="translatedtitle">7 CFR 29.1085 - <span class="hlt">Width</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... 7 Agriculture 2 2013-01-01 2013-01-01 false <span class="hlt">Width</span>. 29.1085 Section 29.1085 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ) (2 ) Waste tolerance (2 ) (2 ) (2 ) 1 Expressed in inches. 2 Expressed in percentage. elements...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24074073','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24074073"><span id="translatedtitle">Bounding the Higgs boson <span class="hlt">width</span> through interferometry.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dixon, Lance J; Li, Ye</p> <p>2013-09-13</p> <p>We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson <span class="hlt">width</span> at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs <span class="hlt">width</span>, in a model that maintains constant Higgs boson signal yields. At Higgs <span class="hlt">widths</span> above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the <span class="hlt">width</span>. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum. PMID:24074073</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21027539','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21027539"><span id="translatedtitle">Definition of the {delta} mass and <span class="hlt">width</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Djukanovic, D.; Scherer, S.; Gegelia, J.</p> <p>2007-08-01</p> <p>In the framework of effective field theory we show that, at two-loop order, the mass and <span class="hlt">width</span> of the {delta} resonance defined via the (relativistic) Breit-Wigner parametrization both depend on the choice of field variables. In contrast, the complex-valued position of the pole of the propagator is independent of this choice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AmJPh..79..353T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AmJPh..79..353T&link_type=ABSTRACT"><span id="translatedtitle">Optimizing Thomson's jumping <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tjossem, Paul J. H.; Brost, Elizabeth C.</p> <p>2011-04-01</p> <p>The height to which <span class="hlt">rings</span> will jump in a Thomson jumping <span class="hlt">ring</span> apparatus is the central question posed by this popular lecture demonstration. We develop a simple time-averaged inductive-phase-lag model for the dependence of the jump height on the <span class="hlt">ring</span> material, its mass, and temperature and apply it to measurements of the jump height for a set of <span class="hlt">rings</span> made by slicing copper and aluminum alloy pipe into varying lengths. The data confirm a peak jump height that grows, narrows, and shifts to smaller optimal mass when the <span class="hlt">rings</span> are cooled to 77 K. The model explains the ratio of the cooled/warm jump heights for a given <span class="hlt">ring</span>, the reduction in optimal mass as the <span class="hlt">ring</span> is cooled, and the shape of the mass resonance. The <span class="hlt">ring</span> that jumps the highest is found to have a characteristic resistance equal to the inductive reactance of the set of <span class="hlt">rings</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010GeoRL..37.2711P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010GeoRL..37.2711P"><span id="translatedtitle">Frost-<span class="hlt">ring</span> chronologies as dendroclimatic proxies of boreal environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Payette, Serge; Delwaide, Ann; Simard, Martin</p> <p>2010-01-01</p> <p>Frost <span class="hlt">rings</span> are formed in tree stems when growing-season frosts affect immature wood cells, producing collapsed cells within annual tree <span class="hlt">rings</span>. Open boreal forests are most susceptible to record growing-season frost because they lack the greenhouse effect commonly observed in closed forests. Here we present a novel method to construct regional frost-<span class="hlt">ring</span> chronologies in lichen-black spruce woodlands of the boreal forest zone. Because the ability of trees to form frost <span class="hlt">rings</span> depends on several factors (including bark thickness and <span class="hlt">ring</span> <span class="hlt">width</span>), we used two models to produce a Frost Composite Index based on a frost susceptibility window of cambial age <30 years. The frost-<span class="hlt">ring</span> chronology showed alternating periods of high and low frost activity that were highly consistent within and among sites. Reconstruction of growing-season frost activity may be used as dendroclimatic proxies of climate variability and may give insights into future risks of frost damage in a warming climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010005742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010005742"><span id="translatedtitle">BOREAS TE-5 Tree <span class="hlt">Ring</span> and Carbon Isotope Ratio Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Ehleriinger, Jim; Brooks, J. Renee; Flanagan, Larry</p> <p>2000-01-01</p> <p>The BOREAS TE-5 team collected several data sets to investigate the vegetation-atmosphere CO2 and H2O exchange processes. These data include tree <span class="hlt">ring</span> <span class="hlt">widths</span> and cellulose carbon isotope data from coniferous trees collected at the BOREAS NSA and SSA in 1993 and 1994 by the BOREAS TE-5 team. <span class="hlt">Ring</span> <span class="hlt">width</span> data are provided for both Picea mariana and Pinus banksiana. The carbon isotope data are provided only for Pinus banksiana. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012IJBm...56....1K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012IJBm...56....1K&link_type=ABSTRACT"><span id="translatedtitle">Tree <span class="hlt">rings</span> of Scots pine ( Pinus sylvestris L.) as a source of information about past climate in northern Poland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koprowski, Marcin; Przybylak, Rajmund; Zielski, Andrzej; Pospieszyńska, Aleksandra</p> <p>2012-01-01</p> <p>Scots pine ( Pinus sylvestris) is a very common tree in Polish forests, and therefore was widely used as timber. A relatively large amount of available wood allowed a long-term chronology to be built up and used as a source of information about past climate. The analysis of reconstructed indexed values of mean temperature in 51-year moving intervals allowed the recognition of the coldest periods in the years 1207-1346, 1383-1425, 1455-1482, 1533-1574, 1627-1646, and 1694-1785. The analysis of extreme wide and narrow <span class="hlt">rings</span> forms a complementary method of examining climatic data within tree <span class="hlt">rings</span>. The tree <span class="hlt">ring</span> <span class="hlt">widths</span>, early wood and late wood <span class="hlt">widths</span> of 16 samples were assessed during the period 1581-1676. The most apparent effect is noted in the dry summer of 1616. According to previous research and our findings, temperature from February to March seems to be one of the most stable climatic factors which influenced pine <span class="hlt">growth</span> in Poland. Correlation coefficients in the calibration and validation procedure gave promising results for temperature reconstruction from the pine chronology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmRe.151..259G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmRe.151..259G"><span id="translatedtitle">Tree <span class="hlt">rings</span> as an indicator of atmospheric pollutant deposition to subalpine spruce forests in the Sudetes (Southern Poland)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Godek, Michał; Sobik, Mieczysław; Błaś, Marek; Polkowska, Żaneta; Owczarek, Piotr; Bokwa, Anita</p> <p>2015-01-01</p> <p>In spite of their moderate altitude (1000-1600 m a.s.l.), the Western Sudety Mountains belong to areas with the most efficient fog precipitation in Europe. Intense industrial activity in the area of windward western foothills caused an exceptional intensification of atmospheric pollutant deposition via precipitation and fog to take place since the 1950s. In the second half of the 1970s a massive spruce forest dieback began affecting around 42% of coniferous forest in the Polish part of the Sudety Mountains. As the result of emission abatement in the region, gradual improvement of forest health status has been observed in the last decade. In October 2010 there were 70 dendrochronological samples collected from Norway spruce (Picea abies) stems at 7 different locations using an increment borer. It was documented for six sites that lowest annual <span class="hlt">growth</span> rates took place between the early eighties and the early nineties which coincides with the highest pollutant deposition rates. Only one site representing the lowest parts of leeward slope showed gradual decrease of tree <span class="hlt">rings</span> as a result of increasing tree age rather than due to an increase in ecological stress conditions. Tree <span class="hlt">ring</span> <span class="hlt">widths</span> were then compared with spatial distribution of fog frequency in the Western Sudety Mountains. The achieved results document a strongly negative dependence of tree <span class="hlt">ring</span> <span class="hlt">widths</span> on fog deposition rates. Spruce forest ecosystems have an ability to respond quickly to both negative and positive stimuli, related to increasing and decreasing environmental contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21174127','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21174127"><span id="translatedtitle">Tree <span class="hlt">rings</span> of Scots pine (Pinus sylvestris L.) as a source of information about past climate in northern Poland.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koprowski, Marcin; Przybylak, Rajmund; Zielski, Andrzej; Pospieszyńska, Aleksandra</p> <p>2012-01-01</p> <p>Scots pine (Pinus sylvestris) is a very common tree in Polish forests, and therefore was widely used as timber. A relatively large amount of available wood allowed a long-term chronology to be built up and used as a source of information about past climate. The analysis of reconstructed indexed values of mean temperature in 51-year moving intervals allowed the recognition of the coldest periods in the years 1207-1346, 1383-1425, 1455-1482, 1533-1574, 1627-1646, and 1694-1785. The analysis of extreme wide and narrow <span class="hlt">rings</span> forms a complementary method of examining climatic data within tree <span class="hlt">rings</span>. The tree <span class="hlt">ring</span> <span class="hlt">widths</span>, early wood and late wood <span class="hlt">widths</span> of 16 samples were assessed during the period 1581-1676. The most apparent effect is noted in the dry summer of 1616. According to previous research and our findings, temperature from February to March seems to be one of the most stable climatic factors which influenced pine <span class="hlt">growth</span> in Poland. Correlation coefficients in the calibration and validation procedure gave promising results for temperature reconstruction from the pine chronology. PMID:21174127</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2549V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2549V"><span id="translatedtitle">Dendrochronology and lakes: using tree-<span class="hlt">rings</span> of alder to reconstruct lake levels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van der Maaten, Ernst; Buras, Allan; Scharnweber, Tobias; Simard, Sonia; Kaiser, Knut; Lorenz, Sebastian; van der Maaten-Theunissen, Marieke; Wilmking, Martin</p> <p>2014-05-01</p> <p> Lake District, northeastern Germany. Tree-<span class="hlt">ring</span> data were collected from black alder forests surrounding the lakes 'Tiefer See', 'Drewitzer See' and 'Großer Fürstenseer See'. At all research sites, increment cores were extracted from at least 15 trees (2 cores per tree) using an increment borer. In the tree-<span class="hlt">ring</span> lab DendroGreif, these cores were prepared and annual tree-<span class="hlt">ring</span> <span class="hlt">widths</span> were measured. Thereafter, site-specific tree-<span class="hlt">ring</span> chronologies were built using established detrending and standardization procedures. Preliminary results show that the <span class="hlt">growth</span> of alder reacts upon water level fluctuations. We visually and statistically compare the developed tree-<span class="hlt">ring</span> chronologies with historical lake-level records, and retrospectively model lake levels. Findings will be presented while critically reflecting upon the quality of these reconstructions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA00701&hterms=Halo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHalo','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA00701&hterms=Halo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHalo"><span id="translatedtitle">Jupiter's Main <span class="hlt">Ring/Ring</span> Halo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (28.5 miles) per picture element (pixel) along Jupiter's <span class="hlt">rings</span>. Because the spacecraft was only about 0.5 degrees above the <span class="hlt">ring</span> plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the <span class="hlt">ring</span> was approximately 2.3 million kilometers (1.4 million miles) away. The arc on the far right of the image is produced when sunlight is scattered by small particles comprising Jupiter's upper atmospheric haze. The <span class="hlt">ring</span> also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.<p/>Jupiter's <span class="hlt">ring</span> system is composed of three parts - - a flat main <span class="hlt">ring</span>, a lenticular halo interior to the main <span class="hlt">ring</span>, and the gossamer <span class="hlt">ring</span>, outside the main <span class="hlt">ring</span>. The near and far arms of Jupiter's main <span class="hlt">ring</span> extend horizontally across the mosaic, joining together at the <span class="hlt">ring</span>'s ansa, on the figure's far left side. The near arm of the <span class="hlt">ring</span> appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the <span class="hlt">ring</span>'s ansa (top image). A faint mist of particles can be seen above and below the main <span class="hlt">rings</span>. This vertically extended 'halo' is unusual in planetary <span class="hlt">rings</span>, and is probably caused by electromagnetic forces pushing the smallest grains out of the <span class="hlt">ring</span> plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the <span class="hlt">ring</span> halo, different brightnesses are shown through color. Brightest features are white or yellow and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1739b0009I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1739b0009I"><span id="translatedtitle">On semi <span class="hlt">ring</span> bornologies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Imran, A. N.; Rakhimov, I. S.; Husain, Sh. K. Said</p> <p>2016-06-01</p> <p>Our main focus in this work is to introduce new structure bornological semi <span class="hlt">rings</span>. This generalizes the theory of algebraic semi <span class="hlt">rings</span> from the algebraic setting to the framework of bornological sets. We give basic properties for this new structure. As well as, We study the fundamental construction of bornological semi <span class="hlt">ring</span> as product, inductive limits and projective limits and their extensions on bornological semi <span class="hlt">ring</span>. Additionally, we introduce the category of bornological semi <span class="hlt">rings</span> and study product and pullback (fiber product) in the category of bornological semi <span class="hlt">rings</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22842114','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22842114"><span id="translatedtitle">Characterisation of ferromagnetic <span class="hlt">rings</span> for Zernike phase plates using the Aharonov-Bohm effect.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Edgcombe, C J; Ionescu, A; Loudon, J C; Blackburn, A M; Kurebayashi, H; Barnes, C H W</p> <p>2012-09-01</p> <p>Holographic measurements on magnetised thin-film cobalt <span class="hlt">rings</span> have demonstrated both onion and vortex states of magnetisation. For a <span class="hlt">ring</span> in the vortex state, the difference between phases of electron paths that pass through the <span class="hlt">ring</span> and those that travel outside it was found to agree very well with Aharonov-Bohm theory within measurement error. Thus the magnetic flux in thin-film <span class="hlt">rings</span> of ferromagnetic material can provide the phase shift required for phase plates in transmission electron microscopy. When a <span class="hlt">ring</span> of this type is used as a phase plate, scattered electrons will be intercepted over a radial range similar to the <span class="hlt">ring</span> <span class="hlt">width</span>. A cobalt <span class="hlt">ring</span> of thickness 20 nm can produce a phase difference of π/2 from a <span class="hlt">width</span> of just under 30 nm, suggesting that the range of radial interception for this type of phase plate can be correspondingly small. PMID:22842114</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JPhCS.238a2047K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JPhCS.238a2047K"><span id="translatedtitle">Directional variance analysis of annual <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumpulainen, P.; Marjanen, K.</p> <p>2010-07-01</p> <p>The wood quality measurement methods are of increasing importance in the wood industry. The goal is to produce more high quality products with higher marketing value than is produced today. One of the key factors for increasing the market value is to provide better measurements for increased information to support the decisions made later in the product chain. Strength and stiffness are important properties of the wood. They are related to mean annual <span class="hlt">ring</span> <span class="hlt">width</span> and its deviation. These indicators can be estimated from images taken from the log ends by two-dimensional power spectrum analysis. The spectrum analysis has been used successfully for images of pine. However, the annual <span class="hlt">rings</span> in birch, for example are less distinguishable and the basic spectrum analysis method does not give reliable results. A novel method for local log end variance analysis based on Radon-transform is proposed. The directions and the positions of the annual <span class="hlt">rings</span> can be estimated from local minimum and maximum variance estimates. Applying the spectrum analysis on the maximum local variance estimate instead of the original image produces more reliable estimate of the annual <span class="hlt">ring</span> <span class="hlt">width</span>. The proposed method is not limited to log end analysis only. It is usable in other two-dimensional random signal and texture analysis tasks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3708892','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3708892"><span id="translatedtitle">Climate Control on Tree <span class="hlt">Growth</span> at the Upper and Lower Treelines: A Case Study in the Qilian Mountains, Tibetan Plateau</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Bao; He, Minhui; Melvin, Thomas M.; Zhao, Yan; Briffa, Keith R.</p> <p>2013-01-01</p> <p>It is generally hypothesized that tree <span class="hlt">growth</span> at the upper treeline is normally controlled by temperature while that at the lower treeline is precipitation limited. However, uniform patterns of inter-annual <span class="hlt">ring-width</span> variations along altitudinal gradients are also observed in some situations. How changing elevation influences tree <span class="hlt">growth</span> in the cold and arid Qilian Mountains, on the northeastern Tibetan Plateau, is of considerable interest because of the sensitivity of the region’s local climate to different atmospheric circulation patterns. Here, a network of four Qilian juniper (Sabina przewalskii Kom.) <span class="hlt">ring-width</span> chronologies was developed from trees distributed on a typical mountain slope at elevations ranging from 3000 to 3520 m above sea level (a.s.l.). The statistical characteristics of the four tree-<span class="hlt">ring</span> chronologies show no significant correlation with increasing elevation. All the sampled tree <span class="hlt">growth</span> was controlled by a common climatic signal (local precipitation) across the investigated altitudinal gradient (520 m). During the common reliable period, covering the past 450 years, the four chronologies have exhibited coherent <span class="hlt">growth</span> patterns in both the high- and low-frequency domains. These results contradict the notion of contrasting climate <span class="hlt">growth</span> controls at higher and lower elevations, and specifically the assumption that inter-annual tree-<span class="hlt">growth</span> variability is controlled by temperature at the upper treeline. It should be stressed that these results relate to the relatively arid conditions at the sampling sites in the Qilian Mountains. PMID:23874871</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012QSRv...34....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012QSRv...34....1S"><span id="translatedtitle">Tree-<span class="hlt">ring</span> analysis of ancient baldcypress trees and subfossil wood</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stahle, David W.; Burnette, Dorian J.; Villanueva, Jose; Cerano, Julian; Fye, Falko K.; Griffin, R. Daniel; Cleaveland, Malcolm K.; Stahle, Daniel K.; Edmondson, Jesse R.; Wolff, Kathryn P.</p> <p>2012-02-01</p> <p>Ancient baldcypress trees found in wetland and riverine environments have been used to develop a network of exactly dated annual <span class="hlt">ring-width</span> chronologies extending from the southeastern United States, across Mexico, and into western Guatemala. These chronologies are sensitive to growing season precipitation in spite of frequently flooded site conditions, and have been used to reconstruct moisture levels the southeastern United States and Mexico for over 1000 years. The El Nino/Southern Oscillation (ENSO) is a major influence on the climate reconstructions derived from these baldcypress chronologies, especially in Mexico where some of the most extreme reconstructed droughts occurred during El Nino events. In the Southeast, the ENSO influence on climate and tree <span class="hlt">growth</span> changes sign from spring to summer, and this change in dynamical forcing is recorded by sub-seasonal chronologies of earlywood and latewood <span class="hlt">width</span>. Most existing baldcypress chronologies have been extended with tree-<span class="hlt">ring</span> data from "subfossil" wood recovered from surface and submerged deposits. Well-preserved subfossil logs have also been recovered in quantity from buried deposits of great age, and may permit development of long continuously dated Holocene chronologies and discontinuous "floating" Pleistocene chronologies. The extensive subfossil baldcypress swamp discovered 6 m below the streets of Washington D.C. was overrun by a transgression of the Potomac estuary, possibly during the previous super interglacial (marine OIS 5e), and provides direct evidence for one potential impact of unmitigated anthropogenic warming and sea level rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1715713K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1715713K"><span id="translatedtitle">Tree <span class="hlt">Growth</span> Responses to Climate Change at the Upper Treeline in the Mountains of Western Tuva</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolunchukova, Mariam; Reznikov, Andrey; Chistyakov, Kirill</p> <p>2015-04-01</p> <p>The response of forest to climate change is most pronounced at higher elevations due to the limitation of <span class="hlt">growth</span> by temperature and precipitation. Modern instrumental measurements show temperature increase during the 20th century that causes rising of upper boundary of forests in the mountain regions. Climate-driven upward tree migration in the region of Altai-Sayan Mountains has been demonstrated in a number of investigations. The purpose of this research was an analysis of the impact of main climatic factors on tree <span class="hlt">growth</span> and current treeline dynamics under the climate changes in the mountains of Western Tuva. Tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies were built based on larch samples (Larix sibirica) of living trees from the upper treeline, the chronologies were compared, their statistics were estimated, and correlation with temperatures and precipitations were analyzed. Tree <span class="hlt">growth</span> is dominated by two major factors - moisture supply and summer temperatures. It is generally hypothesized that tree <span class="hlt">growth</span> at the lower treeline is precipitation limited while at the upper treeline is normally controlled by temperature. However in the upper forest belt temperature can influence tree <span class="hlt">growth</span> negatively as well as positively. Correlations between chronologies and climatic factors revealed different climatic influences on radial <span class="hlt">growth</span> along a north-south gradient in the study area. Within northern wetter areas tree <span class="hlt">ring</span> <span class="hlt">width</span> correlates positively with summer temperatures and negatively with precipitation, so temperature increase leads to rise of upper treeline. Within southern drier areas tree <span class="hlt">ring</span> <span class="hlt">width</span> correlates positively with precipitation and negatively with rising summer temperatures. The analysis showed that in this case the tree <span class="hlt">growth</span> is determined by combination of optimal temperature and maximum precipitation. The results provide evidence of critical importance of temperature and precipitation in the upper forest belt and will be used in subsequent analysis of temporal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16601188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16601188"><span id="translatedtitle">New dust belts of Uranus: one <span class="hlt">ring</span>, two <span class="hlt">ring</span>, red <span class="hlt">ring</span>, blue <span class="hlt">ring</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Pater, Imke; Hammel, Heidi B; Gibbard, Seran G; Showalter, Mark R</p> <p>2006-04-01</p> <p>We compared near-infrared observations of the recently discovered outer <span class="hlt">rings</span> of Uranus with Hubble Space Telescope results. We find that the inner <span class="hlt">ring</span>, R/2003 U 2, is red, whereas the outer <span class="hlt">ring</span>, R/2003 U 1, is very blue. Blue is an unusual color for <span class="hlt">rings</span>; Saturn's enigmatic E <span class="hlt">ring</span> is the only other known example. By analogy to the E <span class="hlt">ring</span>, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G <span class="hlt">ring</span>, which is red, a typical color for dusty <span class="hlt">rings</span>. PMID:16601188</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP41C1411F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP41C1411F"><span id="translatedtitle">Climate and flow variation revealed in tree <span class="hlt">rings</span> of riparian cottonwood, western North Dakota, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Friedman, J. M.; Edmondson, J. R.; Meko, D. M.; Touchan, R.; Griffin, E. R.; Zhou, H.</p> <p>2014-12-01</p> <p>In the western Great Plains, where old upland trees are scarce, <span class="hlt">rings</span> of riparian trees provide an important opportunity for reconstructing past river flow and climate. We present data from 489 plains cottonwood (Populus deltoides ssp. monilifera) trees along the Little Missouri River in western North Dakota. The trees are in randomly selected flood-plain locations within the North and South units of Theodore Roosevelt National Park. The two sites are separated by 160 river km. The Little Missouri watershed contains foothills but no mountains, and most annual high flows result from snowmelt in March or April. Cores were collected and processed using standard dendrochronological methods. The effect of tree age was removed from the chronology using a single relation for the site as a whole (age-curve standardization), which preserves century-scale variation. Trees were as old as 371 years. Given that cottonwood establishment depends upon channel migration, abundant establishment from 1864-1891 at both sites suggests that one or more large floods occurred prior to this period. At the North Unit, establishment continued at a lower rate during the next century, but upstream at the South Unit, tree establishment was greatly curtailed after the 1800s. Comparison of General Land Office Maps from 1907 to recent satellite imagery confirms that channel migration in the last century was much greater within the North Unit, a difference caused in part by a downstream increase in flood amplification by ice jamming. <span class="hlt">Ring</span> <span class="hlt">widths</span> show that even on the flood plain riparian trees were chronically drought stressed. At both sites <span class="hlt">growth</span> was strongly positively correlated with flow and precipitation and weakly negatively correlated with temperature. <span class="hlt">Growth</span> was most strongly correlated with flow and precipitation in April-July, which is consistent with dendrometer-band measurements showing <span class="hlt">growth</span> cessation in August. Whereas cottonwood establishment decreased in the 1900s, <span class="hlt">ring</span> <span class="hlt">widths</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21062034','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21062034"><span id="translatedtitle"><span class="hlt">Ring</span> formation in self-focusing of electromagnetic beams in plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Faisal, M.; Mishra, S. K.; Verma, M. P.; Sodha, M. S.</p> <p>2007-10-15</p> <p>This article presents a paraxial theory of <span class="hlt">ring</span> formation as an initially Gaussian beam propagates in a nonlinear plasma, characterized by significant collisional or ponderomotive nonlinearity. Regions in the axial irradiance-(beam <span class="hlt">width</span>){sup -2} space, for which the <span class="hlt">ring</span> formation occurs and the paraxial theory is valid, have been characterized; for typical points in these regions the dependence of the beam <span class="hlt">width</span> parameter and the radial distribution of irradiance on the distance has been specifically investigated and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02293&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02293&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Saturn's F-<span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This narrow-angle camera image of Saturn's F <span class="hlt">Ring</span> was taken through the Clear filter while at a distance of 6.9 million km from Saturn on 8 November 1980. The brightness variations of this tightly-constrained <span class="hlt">ring</span> shown here indicate that the <span class="hlt">ring</span> is less uniform in makeup than the larger <span class="hlt">rings</span>. JPL managed the Voyager Project for NASA's Office of Space Science</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02202&hterms=wide-angle+diffuse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dwide-angle%2Bdiffuse','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02202&hterms=wide-angle+diffuse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dwide-angle%2Bdiffuse"><span id="translatedtitle">Neptune - full <span class="hlt">ring</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1989-01-01</p> <p>This pair of Voyager 2 images (FDS 11446.21 and 11448.10), two 591-s exposures obtained through the clear filter of the wide angle camera, show the full <span class="hlt">ring</span> system with the highest sensitivity. Visible in this figure are the bright, narrow N53 and N63 <span class="hlt">rings</span>, the diffuse N42 <span class="hlt">ring</span>, and (faintly) the plateau outside of the N53 <span class="hlt">ring</span> (with its slight brightening near 57,500 km).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=281758','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=281758"><span id="translatedtitle">Climate and red spruce <span class="hlt">growth</span> and decline in the northern Appalachians</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Johnson, A. H.; Cook, E. R.; Siccama, T. G.</p> <p>1988-01-01</p> <p>Between the mid-1960s and mid-1980s, red spruce (Picea rubens Sarg.) died at unusual rates on the mountains of New York and western New England. We determined the relationship between standardized tree <span class="hlt">ring</span> <span class="hlt">widths</span> and monthly climate data for calibration and verification periods from 1856 to 1981 and found that after about 1960, there was a distinct shift in the temperature variables related to standardized <span class="hlt">ring</span> <span class="hlt">widths</span> in vigorous spruce. The beginning of widespread spruce mortality, regionwide <span class="hlt">growth</span> decreases, and the shift in response to climate in the early 1960s corresponds to the onset of a decade of unusually cold winters and several consecutive years when severe winter damage was noted across the Northeast in this species. We suggest that the episodes of winter damage are an important initiating and synchronizing factor in the red spruce decline. PMID:16593962</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6478..135G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6478..135G"><span id="translatedtitle">Are There Any Good Digraph <span class="hlt">Width</span> Measures?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ganian, Robert; Hliněný, Petr; Kneis, Joachim; Meister, Daniel; Obdržálek, Jan; Rossmanith, Peter; Sikdar, Somnath</p> <p></p> <p>Several <span class="hlt">width</span> measures for digraphs have been proposed in the last few years. However, none of them possess all the "nice" properties of treewidth, namely, (1) being algorithmically useful, that is, admitting polynomial-time algorithms for a large class of problems on digraphs of bounded <span class="hlt">width</span>; and (2) having nice structural properties such as being monotone under taking subdigraphs and some form of arc contractions. As for (1), MSO1 is the least common denominator of all reasonably expressive logical languages that can speak about the edge/arc relation on the vertex set, and so it is quite natural to demand efficient solvability of all MSO1-definable problems in this context. (2) is a necessary condition for a <span class="hlt">width</span> measure to be characterizable by some version of the cops-and-robber game characterizing treewidth. More specifically, we introduce a notion of a directed topological minor and argue that it is the weakest useful notion of minors for digraphs in this context. Our main result states that any reasonable digraph measure that is algorithmically useful and structurally nice cannot be substantially different from the treewidth of the underlying undirected graph.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010zofp.book...39W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010zofp.book...39W"><span id="translatedtitle"><span class="hlt">Growth</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waag, Andreas</p> <p></p> <p>This chapter is devoted to the <span class="hlt">growth</span> of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the <span class="hlt">growth</span> of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the <span class="hlt">growth</span> of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different <span class="hlt">growth</span> techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, <span class="hlt">growth</span> techniques range from low cost wet chemical <span class="hlt">growth</span> at almost room temperature to high quality MOCVD <span class="hlt">growth</span> at temperatures above 1, 000∘C. In most cases, there is a very strong tendency of c-axis oriented <span class="hlt">growth</span>, with a much higher <span class="hlt">growth</span> rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal <span class="hlt">growth</span>. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02292&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02292&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Saturn's F-<span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This narrow-angle camera image of Saturn's F <span class="hlt">Ring</span> was taken through the Clear filter while at a distance of 0.75 million km from Saturn on 12 November 1980. The kinks and braids of this tightly-constrained <span class="hlt">ring</span> are visible along with the outer edge of the A <span class="hlt">Ring</span>. JPL managed the Voyager Project for NASA's Office of Space Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=liquid+AND+nitrogen&id=EJ827419','ERIC'); return false;" href="http://eric.ed.gov/?q=liquid+AND+nitrogen&id=EJ827419"><span id="translatedtitle">The Jumping <span class="hlt">Ring</span> Experiment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.</p> <p>2009-01-01</p> <p>The jumping <span class="hlt">ring</span> experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the <span class="hlt">rings</span> and their metallurgical state. In general, aluminium <span class="hlt">rings</span> are…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Uranus&id=EJ166551','ERIC'); return false;" href="http://eric.ed.gov/?q=Uranus&id=EJ166551"><span id="translatedtitle"><span class="hlt">Rings</span> Around Uranus</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Maran, Stephen P.</p> <p>1977-01-01</p> <p>Events leading up to the discovery of the <span class="hlt">rings</span> of Uranus are described. The methods used and the logic behind the methods are explained. Data collected to prove the existence of the <span class="hlt">rings</span> are outlined and theories concerning the presence of planetary <span class="hlt">rings</span> are presented. (AJ)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EGUGA..15.8421S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EGUGA..15.8421S&link_type=ABSTRACT"><span id="translatedtitle">Tree <span class="hlt">growth</span> and forest ecosystem functioning in Eurasia under extreme climate conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saurer, Matthias; Kirdyanov, Alexander; Prokushkin, Anatoly; Bryukhanova, Marina; Knorre, Anastasia; Nasyrov, Muhtor; Frank, David; Treydte, Kerstin; Sidorova, Olga; Siegwolf, Rolf</p> <p>2013-04-01</p> <p>The main goal of this study is to improve our understanding of the influence of a changing climate on trees in extreme conditions by a detailed analysis of the factors controlling tree-<span class="hlt">ring</span> <span class="hlt">growth</span>. We investigated forest ecosystems in regions that are very sensitive to climatic changes and where rapid and dramatic environmental and climatic changes are on-going, namely, the high latitude permafrost region in Central Siberia (Russia), the semi-arid dry areas in Central Asia (Uzbekistan) and high-altitude sites in the Alps (Switzerland). Tree-<span class="hlt">ring</span> parameters studied were <span class="hlt">ring-width</span>, density, cell number and structure and the ratio of carbon and oxygen isotopes. An important aspect of the work was the characterization of seasonal <span class="hlt">growth</span> and water supply of trees. Intra-seasonal dynamics of tree-<span class="hlt">ring</span> formation was correlated with monitored environmental factors, such as air and soil temperature and moisture, permafrost depth and the isotope composition of soil water, of precipitation, and of stream water. Intra-annual and long-term variability of the main tree-<span class="hlt">ring</span> parameters were compared for the different regions. The results obtained help us to understand better tree-physiological processes valid under contrasting environmental conditions. For instance, the relationship between the onset of cell division in the cambium and the thermo-hydrological soil regime was used to determine the period of the year with the highest influence on the start of tree-<span class="hlt">ring</span> formation. Seasonally resolved oxygen isotope depth profiles of soil water and concurrent xylem and leaf water measurements show the importance of time-lags between precipitation, leaf processes and <span class="hlt">growth</span>. The data obtained are important for improving tree-<span class="hlt">ring</span> <span class="hlt">growth</span> models and estimating future tree <span class="hlt">growth</span> under climate change. Funding: SNF SCOPES IZ73Z0_128035</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA03001&hterms=Image+mosaic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DImage%2Bmosaic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA03001&hterms=Image+mosaic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DImage%2Bmosaic"><span id="translatedtitle">Jovian <span class="hlt">Ring</span> System Mosaic</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p><p/>NASA's Galileo spacecraft acquired this mosaic of Jupiter's <span class="hlt">ring</span> system (top) when the spacecraft was in Jupiter's shadow looking back toward the Sun. Jupiter's <span class="hlt">ring</span> system (inset diagram) is composed of three parts: an outermost gossamer <span class="hlt">ring</span>, a flat main <span class="hlt">ring</span>, and an innermost donut-shaped halo. These <span class="hlt">rings</span> are made up of dust-sized particles that are blasted off of the nearby inner satellites by small impacts. This image was taken on November 9, 1996 at a distance of 2.3 million kilometers (1.4 million miles).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23580756','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23580756"><span id="translatedtitle">Suppressor of K+ transport <span class="hlt">growth</span> defect 1 (SKD1) interacts with <span class="hlt">RING</span>-type ubiquitin ligase and sucrose non-fermenting 1-related protein kinase (SnRK1) in the halophyte ice plant.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chiang, Chih-Pin; Li, Chang-Hua; Jou, Yingtzy; Chen, Yu-Chan; Lin, Ya-Chung; Yang, Fang-Yu; Huang, Nu-Chuan; Yen, Hungchen Emilie</p> <p>2013-05-01</p> <p>SKD1 (suppressor of K+ transport <span class="hlt">growth</span> defect 1) is an AAA-type ATPase that functions as a molecular motor. It was previously shown that SKD1 accumulates in epidermal bladder cells of the halophyte Mesembryanthemum crystallinum. SKD1 knock-down Arabidopsis mutants showed an imbalanced Na+/K+ ratio under salt stress. Two enzymes involved in protein post-translational modifications that physically interacted with McSKD1 were identified. McCPN1 (copine 1), a <span class="hlt">RING</span>-type ubiquitin ligase, has an N-terminal myristoylation site that links to the plasma membrane, a central copine domain that interacts with McSKD1, and a C-terminal <span class="hlt">RING</span> domain that catalyses protein ubiquitination. In vitro ubiquitination assay demonstrated that McCPN1 was capable of mediating ubiquitination of McSKD1. McSnRK1 (sucrose non-fermenting 1-related protein kinase) is a Ser/Thr protein kinase that contains an N-terminal STKc catalytic domain to phosphorylate McSKD1, and C-terminal UBA and KA1 domains to interact with McSKD1. The transcript and protein levels of McSnRK1 increased as NaCl concentrations increased. The formation of an SKD1-SnRK1-CPN1 ternary complex was demonstrated by yeast three-hybrid and bimolecular fluorescence complementation. It was found that McSKD1 preferentially interacts with McSnRK1 in the cytosol, and salt induced the re-distribution of McSKD1 and McSnRK1 towards the plasma membrane via the microtubule cytoskeleton and subsequently interacted with <span class="hlt">RING</span>-type E3 McCPN1. The potential effects of ubiquitination and phosphorylation on McSKD1, such as changes in the ATPase activity and cellular localization, and how they relate to the functions of SKD1 in the maintenance of Na+/K+ homeostasis under salt stress, are discussed. PMID:23580756</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003IJCli..23..157T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003IJCli..23..157T"><span id="translatedtitle">Preliminary reconstructions of spring precipitation in southwestern Turkey from tree-<span class="hlt">ring</span> <span class="hlt">width</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Touchan, Ramzi; Garfin, Gregg M.; Meko, David M.; Funkhouser, Gary; Erkan, Nesat; Hughes, Malcolm K.; Wallin, Brian S.</p> <p>2003-02-01</p> <p>Two reconstructions of spring (May-June) precipitation have been developed for southwestern Turkey. The first reconstruction (1776-1998) was developed from principal components of nine chronologies of Cedrus libani, Juniperus excelsa, Pinus brutia, and Pinus nigra. The second reconstruction (1339-1998) was derived from principal components of three J. excelsa chronologies. Calibration and verification statistics of both reconstructions indicate reasonably accurate reconstruction of spring precipitation for southwestern Turkey, and show clear evidence of multi-year to decadal variations in spring precipitation. The longest period of reconstructed spring drought, defined as consecutive years with less than 80% of normal May-June precipitation, was 4 years (1476-79). Only one drought event of this duration has occurred during the last six centuries. Monte Carlo analysis indicates a less than 33% probability that southwestern Turkey has experienced spring drought longer than 5 years in the past 660 years. Apart from the 1476-79 extended dry period, spring droughts of 3 years in length have only occurred from 1700 to the present. The longest reconstructed wet period, defined as consecutive years with more than 120% of normal May-June precipitation, was 4 years (1532-35). The absence of extended spring drought during the 16th and 17th centuries and the occurrence of extended wet spring periods during these centuries suggest a possible regime shift in climate. Preliminary analysis of links between large-scale climatic variation and these climate reconstructions shows that there is a relationship between extremes in spring precipitation and anomalous atmospheric circulation in the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19812546','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19812546"><span id="translatedtitle">Saturn's largest <span class="hlt">ring</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P</p> <p>2009-10-22</p> <p>Most planetary <span class="hlt">rings</span> in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer <span class="hlt">rings</span> and Saturn's E <span class="hlt">ring</span>, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous <span class="hlt">ring</span> associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The <span class="hlt">ring</span>'s vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these <span class="hlt">ring</span> particles span the Saturnian system from the main <span class="hlt">rings</span> to the edges of interplanetary space. The <span class="hlt">ring</span>'s normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer <span class="hlt">ring</span>, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the <span class="hlt">ring</span> populated with material. <span class="hlt">Ring</span> particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus. PMID:19812546</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMPP52A..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMPP52A..02S"><span id="translatedtitle">Reading the bass line: How well do moisture-sensitive tree <span class="hlt">rings</span> track decadal variability?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>St George, S.; Ault, T. R.</p> <p>2010-12-01</p> <p>Most dendroclimatic studies assess past changes in decadal variability by first reconstructing an annually-resolved target variable, and then applying some form of filter that emphasizes variability within a specific frequency band. We evaluate the ability of a network of tree-<span class="hlt">ring</span> records along the central Pacific Coast of the United States (hereafter, the CPC) to estimate the behavior of an exceptionally vigorous decadal pattern in winter precipitation. The CPC is one of the few regions in North America where precipitation records exhibited strong variability at decadal timescales during the last century. Fewer than one-quarter of all tree-<span class="hlt">ring</span> chronologies from this region are good proxies for the decadal pattern, but Monte Carlo analysis demonstrates that the level of similarity observed between the <span class="hlt">ring-width</span> network and winter precipitation was not likely to occur due to chance. By screening the network to retain those tree-<span class="hlt">ring</span> chronologies that are optimal predictors of our decadal target, we produce an estimate of that component that is better than those obtained from either projecting the signal over all records or over some function (either the network’s mean or its leading principal component) that describes tree <span class="hlt">growth</span> across the entire network. Projecting the pattern over the entire length of the tree-<span class="hlt">ring</span> chronologies indicated that decadal variability in regional precipitation was most vigorous during the mid and late-20th century. Between 1650 and 1930, the amplitude of the decadal pattern was relatively weak and the proxy estimates show a limited number of decadal events separated by longer intervals of lower variance. Our results indicate that strong decadal variability is a relatively new feature of the winter climate of the CPC region, and that this type of behavior has been uncommon for most of the last three and a half centuries. They also provide another example of the benefits of reconstruction approaches that evaluate the ability of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.2526B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.2526B"><span id="translatedtitle">Tree-<span class="hlt">ring</span> based reconstruction of past lahar activity at Popocat</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bollschweiler, M.; Stoffel, M.; Vázquez Selem, L.; Palacios, D.</p> <p>2009-04-01</p> <p>Lahars are rapid, saturated flows of water and rock fragments that occur on volcanoes and that can be triggered either by volcanic activity or by intense precipitation falling on unconsolidated volcanic deposits. As their occurrence is unpredictable, as the flow contains sometimes considerably large rock fragments and as the flow is able to travel long distances even on gentle gradients, lahars represent one of the most destructive natural disasters in terms of loss of human lives and property damage. In order to realistically assess hazards, knowledge on the occurrence and timing of past lahar activity is of crucial importance. However, archival data on past events is usually scarce or completely missing. Tree-<span class="hlt">ring</span> records have repeatedly proved to be a reliable data source for the reconstruction of past geomorphic events. However, tree <span class="hlt">rings</span> have hardly ever been applied for the identification of past lahars. Therefore, it was the aim of this study (i) to identify and describe disturbances in tree <span class="hlt">growth</span> induced by well-documented lahar events and on this basis (ii) to recognize older, unknown lahar events with tree-<span class="hlt">ring</span> analyses. Based on these goals, we collected 140 tree-<span class="hlt">ring</span> series from 62 trees (Abies religiosa, Pinus hartwegii, Pinus ayacahuite) standing inside or adjacent to the lahar channel in the Huiloac gorge at Popocatépetl volcano, central Mexico. Most commonly, the known lahar events of 1997 and 2001 resulted in abrupt changes in tree-<span class="hlt">ring</span> <span class="hlt">width</span> as well as injuries. The same <span class="hlt">growth</span> disturbances could be identified in the tree-<span class="hlt">ring</span> series, indicating that five previously unknown lahar events would have occurred during the 20th century. Popocatépetl is one of the best surveyed volcanoes in the world and past eruptions are precisely noted in archives. As most of these unknown events occurred during periods with no volcanic activity, we believe that they were rainfall-induced rather than related to volcanic activity. This study revealed the potential</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812240Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812240Z&link_type=ABSTRACT"><span id="translatedtitle">Early and Mid-Holocene Climate Variability - A Multi-Proxy Approach from Multi-Millennial Tree <span class="hlt">Ring</span> Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ziehmer, Malin Michelle; Nicolussi, Kurt; Schlüchter, Christian; Leuenberger, Markus</p> <p>2016-04-01</p> <p>Most reconstructions of Holocene climate variability in the Alps are based on low-frequency archives such as glacier and tree line fluctuations. However; recent finds of wood remains in glacier forefields in the Alps reveal a unique high-frequency archive allowing climate reconstruction over the entire Holocene. The evolution of Holocene climate can be reconstructed by using a multi-proxy approach combining tree <span class="hlt">ring</span> <span class="hlt">width</span> and multiple stable isotope chronologies by establishing highly resolved stable isotope records from calendar-dated wood which covers the past 9000 years b2k. Therefore, we collected samples in the Alps covering a large SW-NE transect, primarily in glacier forefields but also in peat bogs and small lakes. The multiple sample locations allow the analysis of climatic conditions along a climatic gradient characterized by the change from an Atlantic to a more continental climate. Subsequently, tree <span class="hlt">ring</span> <span class="hlt">widths</span> are measured and samples are calendrically dated by means of tree <span class="hlt">ring</span> analysis. Due to the large amount of samples for stable isotope analysis (> 8000 samples to cover the entire Holocene by guaranteeing a sample replication of 4 samples per time unit of 5 years), dated wood samples are separated into 5-year tree <span class="hlt">ring</span> blocks. These blocks are sliced and the cellulose is extracted after a standardized procedure and crushed by ultrasonic homogenization. In order to establish multi-proxy records, the stable isotopes of carbon, oxygen and hydrogen are simultaneously measured. Both the 5-year tree <span class="hlt">ring</span> <span class="hlt">width</span> and multiple stable isotope series offer new insights into the Early and Mid-Holocene climate and its variability in the Alps. The stable isotope records reveal interesting low-frequency variability. But they also display expected offsets caused by the measurement of individual trees revealing effects of sampling site, tree species and <span class="hlt">growth</span> trend. These effects offer an additional insight into the tree <span class="hlt">growth</span> and stand behavior of single</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11..131S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11..131S"><span id="translatedtitle">δ13C and δ18O in Siberian tree <span class="hlt">rings</span> as indicators of environmental changes in the Eurasian north</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sidorova, O. V.; Siegwolf, R. T. W.; Saurer, M.; Boettger, T.; Vaganov, E. A.</p> <p>2009-04-01</p> <p>According to the Intergovernmental Panel on Climate Change report (IPCC 2007) some aspects of the current climate change are not unusual, but others are. Therefore we need to look into the past for revealing "unusual" (extremely warm or cold) climatic changes. The application of long-term tree-<span class="hlt">ring</span> chronologies in paleoclimate reconstructions helps us to evaluate climatic and environmental changes in the past and to estimate the magnitude of the recent warming. The application of the stable isotope analysis to classical dendrochronology is steadily increasing because stable isotopes provide complementary information about climatic variabilities, which is not available with tree <span class="hlt">ring</span> <span class="hlt">width</span> alone. In northern latitude forests, stable isotopes may yield insight into precipitation variability, while tree-<span class="hlt">ring</span> <span class="hlt">width</span> and density are more sensitive to temperature changes. Using stable isotopes is therefore very helpful in improving our understanding of the forest response to environmental changes. The tree-<span class="hlt">ring</span> <span class="hlt">width</span> and stable isotope (δ13C, δ18O) analyses were carried out for Siberian tree <span class="hlt">ring</span> chronologies from northeastern Yakutia (70N-148E) and eastern Taimyr (71N-102E). The results showed extremely warm AD 900-1100, AD 1950-2006 and extremely cold AD 516-560, AD 1600-1650, AD 1800-1850 periods during the late Holocene. Isotope analyses reveal new supplementary signals about the moisture regime, in particular a correlation to July precipitation was found for the calibration period. We detected a strong relationship between the oxygen isotope ratio of tree <span class="hlt">rings</span> and Greenland ice core chronologies [Meese et al. 1994] for the Medieval and recent periods, which indicate similarities in the nature of low-frequency temperature variability in these two regions. Further, we found that trees from the vast Subarctic Eurasia zone (eastern Taimyr and northeastern Yakutia) showed a decrease in the tree radial <span class="hlt">growth</span>, δ13C, δ18O in whole wood and cellulose after major</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023607','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023607"><span id="translatedtitle">Artifacts for Calibration of Submicron <span class="hlt">Width</span> Measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Grunthaner, Frank; Grunthaner, Paula; Bryson, Charles, III</p> <p>2003-01-01</p> <p>Artifacts that are fabricated with the help of molecular-beam epitaxy (MBE) are undergoing development for use as dimensional calibration standards with submicron <span class="hlt">widths</span>. Such standards are needed for calibrating instruments (principally, scanning electron microscopes and scanning probe microscopes) for measuring the <span class="hlt">widths</span> of features in advanced integrated circuits. Dimensional calibration standards fabricated by an older process that involves lithography and etching of trenches in (110) surfaces of single-crystal silicon are generally reproducible to within dimensional tolerances of about 15 nm. It is anticipated that when the artifacts of the present type are fully developed, their critical dimensions will be reproducible to within 1 nm. These artifacts are expected to find increasing use in the semiconductor-device and integrated- circuit industries as the <span class="hlt">width</span> tolerances on semiconductor devices shrink to a few nanometers during the next few years. Unlike in the older process, one does not rely on lithography and etching to define the critical dimensions. Instead, one relies on the inherent smoothness and flatness of MBE layers deposited under controlled conditions and defines the critical dimensions as the thicknesses of such layers. An artifact of the present type is fabricated in two stages (see figure): In the first stage, a multilayer epitaxial wafer is grown on a very flat substrate. In the second stage, the wafer is cleaved to expose the layers, then the exposed layers are differentially etched (taking advantage of large differences between the etch rates of the different epitaxial layer materials). The resulting structure includes narrow and well-defined trenches and a shelf with thicknesses determined by the thicknesses of the epitaxial layers from which they were etched. Eventually, it should be possible to add a third fabrication stage in which durable, electronically inert artifacts could be replicated in diamondlike carbon from a master made by</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ThApC.107..519Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ThApC.107..519Y"><span id="translatedtitle">Eigen analysis of tree-<span class="hlt">ring</span> records: part 3, taking heteroscedasticity and sampling effects into consideration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Bao; Sonechkin, Dmitry M.; Datsenko, Nina M.; Ivashchenko, Nadezda N.; Liu, Jingjing; Qin, Chun</p> <p>2012-02-01</p> <p>This paper reports on the further development of a new technique for standardization of tree-<span class="hlt">ring</span> records called the eigen analysis of tree-<span class="hlt">ring</span> records. The data are from the same sample set of 56 long-lived Qilian junipers ( Sabina przewalskii Kom.) from the Dulan region in western China as was used in our previous paper (Yang et al. 2011b). To assess the heteroscedasticity of individual record deviations from the sample set regional curve (RC), we tested five different definitions of those deviations. Direct computations of eigenvectors of all relevant intrarecord covariation matrices turned out to be greatly affected by observational and computational noise; an analytic approximation of these vectors was therefore desirable. The Bessel function of the first kind and the zero order proved suitable for such an approximation, especially because the deviations were defined via subtraction of the RC from raw <span class="hlt">ring</span> <span class="hlt">width</span> records. Exclusion of the contributions of the first segment of the Bessel approximation, corresponding to the extremely large first eigenvalue, rendered individual record deviations from RC homoscedastic. Therefore, the routine Fourier basis became applicable to extract climate-dependent components of the residual deviations. A Fourier expansion of the Dulan chronology revealed the quasi-200-year-long solar activity cycle to be the main factor affecting Dulan tree <span class="hlt">growth</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title49-vol3/pdf/CFR-2012-title49-vol3-sec179-400-9.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title49-vol3/pdf/CFR-2012-title49-vol3-sec179-400-9.pdf"><span id="translatedtitle">49 CFR 179.400-9 - Stiffening <span class="hlt">rings</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... moment of inertia of the <span class="hlt">ring</span>. The effective <span class="hlt">width</span> of jacket plate on each side of the attachment of the... moment of inertia large enough to support the critical collapsing pressure, as determined by either of the following formulas: I = / E, or I′ = / E Where: I = required moment of inertia of stiffening...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title49-vol3/pdf/CFR-2014-title49-vol3-sec179-400-9.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title49-vol3/pdf/CFR-2014-title49-vol3-sec179-400-9.pdf"><span id="translatedtitle">49 CFR 179.400-9 - Stiffening <span class="hlt">rings</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... moment of inertia of the <span class="hlt">ring</span>. The effective <span class="hlt">width</span> of jacket plate on each side of the attachment of the... moment of inertia large enough to support the critical collapsing pressure, as determined by either of the following formulas: I = / E, or I′ = / E Where: I = required moment of inertia of stiffening...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3069S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3069S"><span id="translatedtitle">Dust and Planetary <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siddiqui, Muddassir</p> <p></p> <p>ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary <span class="hlt">ring</span> dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B <span class="hlt">ring</span> spokes, planetary <span class="hlt">rings</span> at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary <span class="hlt">rings</span>. A planetary <span class="hlt">ring</span> is a <span class="hlt">ring</span> of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have <span class="hlt">rings</span>. But the most notable one is the Saturn's <span class="hlt">ring</span> which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous <span class="hlt">ring</span> system. The <span class="hlt">ring</span> swirling around Saturn consists of chunks of ice and dust. Most <span class="hlt">rings</span> were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's <span class="hlt">rings</span> might be older than that. The dust particles in the <span class="hlt">ring</span> collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the <span class="hlt">rings</span>. Pluto is not known to have any <span class="hlt">ring</span> system but some Astronomers believe that New Horizons probe might find a <span class="hlt">ring</span> system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary <span class="hlt">ring</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AAS...204.6011B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AAS...204.6011B"><span id="translatedtitle">QSO Narrow [OIII] Line <span class="hlt">Width</span> and Host Galaxy Luminosity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bonning, E. W.; Shields, G. A.; Salviander, S.</p> <p>2004-05-01</p> <p>Established correlations between galaxy bulge luminosity L, black hole mass MBH, and stellar velocity dispersion sigma in galaxies suggest a close relationship between the <span class="hlt">growth</span> of supermassive black holes and their host galaxies. Measurements of the MBH - sigma relationship as a function of cosmic time may shed light on the origin of this relationship. One approach is to derive MBH and sigma from the <span class="hlt">widths</span> of QSO broad and narrow lines, respectively (Shields et al. 2003, ApJ, 583, 124; Nelson 2000, ApJ, 544, L91). We investigate the utility of using the velocity of the narrow line emitting gas as a surrogate for stellar velocity dispersion in QSOs by examining host magnitudes and [OIII] line <span class="hlt">widths</span> for low redshift QSOs. For our limited range of L, the increase in sigma with L predicted by the Faber-Jackson relation is substantially obscured by scatter. However, sigma([O III]) is consistent in the mean with host galaxy luminosity. EWB is a NASA GSRP fellow. GAS and SS are supported under Texas Advanced Research Program grant 003658-0177-2001 and NSF grant AST-0098594.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhFl...27h7101G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhFl...27h7101G"><span id="translatedtitle">The evolution of swirling axisymmetric vortex <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gargan-Shingles, C.; Rudman, M.; Ryan, K.</p> <p>2015-08-01</p> <p>Swirling vortex <span class="hlt">rings</span> form in any turbulent flow where a swirling component is present, such as in combustion chambers or the downwash of helicopter blades. Instabilities on initially non-swirling vortex <span class="hlt">rings</span> result in a localized swirl velocity being generated within the core. The presence of a swirl component of velocity in a vortex <span class="hlt">ring</span> modifies the relaxation and evolution of numerical Gaussian cores in a manner that is currently unknown. The evolution of Gaussian axisymmetric vortex <span class="hlt">rings</span> of size 0.2 < Λ < 0.5, with Gaussian swirls of magnitude 0.0 < W < 0.5, is analyzed with reference to the governing equations. A relaxation time, at which the initial Gaussian approximation has minimal influence on the subsequent evolution, has been estimated for each case. An axial vortex forms along the axis of the <span class="hlt">ring</span> and is responsible for the <span class="hlt">growth</span> of a shear layer that is found to form at the leading edge. The circulation based Reynolds number is set at 10 000 to encourage the <span class="hlt">growth</span> of shear layer instabilities from within this region. Secondary vortex <span class="hlt">rings</span> are subsequently shown to evolve from the Kelvin-Helmholtz instability for shear layers of sufficient strength and are convected around the original <span class="hlt">ring</span> and shed from the system. It is shown that complete settling of the strain rate within the core does not occur until all sheddings have ceased. Increasing the swirl magnitude past that considered in this paper is expected to result in the original <span class="hlt">ring</span> losing its structure before the instability can occur. The evolution is found to be qualitatively similar to that of a piston generated axisymmetric vortex <span class="hlt">ring</span> with swirl, with both cases eventually reaching a similar quasi-steady state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GPC...124...95D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GPC...124...95D"><span id="translatedtitle">Drought-induced weakening of <span class="hlt">growth</span>-temperature associations in high-elevation Iberian pines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diego Galván, J.; Büntgen, Ulf; Ginzler, Christian; Grudd, Håkan; Gutiérrez, Emilia; Labuhn, Inga; Julio Camarero, J.</p> <p>2015-01-01</p> <p>The <span class="hlt">growth</span>/climate relationship of theoretically temperature-controlled high-elevation forests has been demonstrated to weaken over recent decades. This is likely due to new tree <span class="hlt">growth</span> limiting factors, such as an increasing drought risk for ecosystem functioning and productivity across the Mediterranean Basin. In addition, declining tree <span class="hlt">growth</span> sensitivity to spring temperature may emerge in response to increasing drought stress. Here, we evaluate these ideas by assessing the <span class="hlt">growth</span>/climate sensitivity of 1500 tree-<span class="hlt">ring</span> <span class="hlt">width</span> (TRW) and 102 maximum density (MXD) measurement series from 711 and 74 Pinus uncinata trees, respectively, sampled at 28 high-elevation forest sites across the Pyrenees and two relict populations of the Iberian System. Different dendroclimatological standardization and split period approaches were used to assess the high- to low-frequency behavior of 20th century tree <span class="hlt">growth</span> in response to temperature means, precipitation totals and drought indices. Long-term variations in TRW track summer temperatures until about 1970 but diverge afterwards, whereas MXD captures the recent temperature increase in the low-frequency domain fairly well. On the other hand summer drought has increasingly driven TRW along the 20th century. Our results suggest fading temperature sensitivity of Iberian high-elevation P. uncinata forest <span class="hlt">growth</span>, and reveal the importance of summer drought that is becoming the emergent limiting factor of tree <span class="hlt">ring</span> <span class="hlt">width</span> formation in many parts of the Mediterranean Basin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010IEITF..91...83F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010IEITF..91...83F"><span id="translatedtitle">Traceable <span class="hlt">Ring</span> Signature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fujisaki, Eiichiro; Suzuki, Koutarou</p> <p></p> <p>The <span class="hlt">ring</span> signature allows a signer to leak secrets anonymously, without the risk of identity escrow. At the same time, the <span class="hlt">ring</span> signature provides great flexibility: No group manager, no special setup, and the dynamics of group choice. The <span class="hlt">ring</span> signature is, however, vulnerable to malicious or irresponsible signers in some applications, because of its anonymity. In this paper, we propose a traceable <span class="hlt">ring</span> signature scheme. A traceable <span class="hlt">ring</span> scheme is a <span class="hlt">ring</span> signature except that it can restrict “excessive” anonymity. The traceable <span class="hlt">ring</span> signature has a tag that consists of a list of <span class="hlt">ring</span> members and an issue that refers to, for instance, a social affair or an election. A <span class="hlt">ring</span> member can make any signed but anonymous opinion regarding the issue, but only once (per tag). If the member submits another signed opinion, possibly pretending to be another person who supports the first opinion, the identity of the member is immediately revealed. If the member submits the same opinion, for instance, voting “yes” regarding the same issue twice, everyone can see that these two are linked. The traceable <span class="hlt">ring</span> signature can suit to many applications, such as an anonymous voting on a BBS. We formalize the security definitions for this primitive and show an efficient and simple construction in the random oracle model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeoRL..3824705D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoRL..3824705D"><span id="translatedtitle">Three centuries of Myanmar monsoon climate variability inferred from teak tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Arrigo, Rosanne; Palmer, Jonathan; Ummenhofer, Caroline C.; Kyaw, Nyi Nyi; Krusic, Paul</p> <p>2011-12-01</p> <p>Asian monsoon extremes critically impact much of the globe’s population. Key gaps in our understanding of monsoon climate remain due to sparse coverage of paleoclimatic information, despite intensified recent efforts. Here we describe a <span class="hlt">ring</span> <span class="hlt">width</span> chronology of teak, one of the first high-resolution proxy records for the nation of Myanmar. Based on 29 samples from 20 living trees and spanning from 1613-2009, this record, from the Maingtha forest reserve north of Mandalay, helps fill a substantial gap in spatial coverage of paleoclimatic records for monsoon Asia. Teak <span class="hlt">growth</span> is positively correlated with rainfall and Palmer Drought Severity Index variability over Myanmar, during and prior to the May-September monsoon season (e.g., r = 0.38 with Yangon rainfall, 0.001, n 68). Importantly, this record also correlates significantly with larger-scale climate indices, including core Indian rainfall (23°N, 76°E a particularly sensitive index of the monsoon), and the El Niño-Southern Oscillation (ENSO). The teak <span class="hlt">ring</span> <span class="hlt">width</span> value following the so-called 1997-98 El Niño of the Century suggests that this was one of the most severe droughts in the past ˜300 years in Myanmar. Evidence for past dry conditions inferred for Myanmar is consistent with tree-<span class="hlt">ring</span> records of decadal megadroughts developed for Thailand and Vietnam. These results confirm the climate signature related to monsoon rainfall in the Myanmar teak record and the considerable potential for future development of climate-sensitive chronologies from Myanmar and the broader region of monsoon Asia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA01270&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA01270&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Sunset on Saturn's <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1996-01-01</p> <p>This is a rare view of Saturn's <span class="hlt">rings</span> seen just after the Sun has set below the <span class="hlt">ring</span> plane, taken with the Hubble Space Telescope on Nov. 21, 1995.<p/>This perspective is unusual because the Earth is slightly above (2.7 degrees latitude) Saturn's <span class="hlt">rings</span> and the Sun is below them. Normally we see the <span class="hlt">rings</span> fully illuminated by the Sun.<p/>The photograph shows three bright <span class="hlt">ring</span> features: the F <span class="hlt">Ring</span>, the Cassini Division, and the C <span class="hlt">Ring</span> (moving from the outer <span class="hlt">rings</span> to the inner). The low concentration of material in these <span class="hlt">rings</span> allows light from the Sun to shine through them. The A and B <span class="hlt">rings</span> are much denser, which limits the amount of light that penetrates through them. Instead, they are faintly visible because they reflect light from Saturn's disk.<p/>Scientists believe that the F <span class="hlt">Ring</span> is slightly warped because it disappears part way around on the right (West) side. Hubble's high resolution shows the that A <span class="hlt">Ring</span>'s shadow obscures part of the F <span class="hlt">ring</span> (right).<p/>The image was assembled from 20 exposures taken with Wide Field Planetary Camera-2 over 8 hours.<p/>The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.<p/>This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ClDy...40.1019C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ClDy...40.1019C"><span id="translatedtitle">A tree-<span class="hlt">ring</span> reconstruction of East Anglian (UK) hydroclimate variability over the last millennium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cooper, Richard J.; Melvin, Thomas M.; Tyers, Ian; Wilson, Rob J. S.; Briffa, Keith R.</p> <p>2013-02-01</p> <p>We present an annually resolved reconstruction of spring-summer precipitation variability in East Anglia, UK (52-53°N, 0-2°E) for the period AD 900-2009. A continuous regional network of 723 living (AD 1590-2009) and historical (AD 781-1790) oak ( Quercus sp.) <span class="hlt">ring-width</span> series has been constructed and shown to display significant sensitivity to precipitation variability during the March-July season. The existence of a coherent common <span class="hlt">growth</span> signal is demonstrated in oaks growing across East Anglia, containing evidence of near-decadal aperiodic variability in precipitation throughout the last millennium. Positive correlations are established between oak <span class="hlt">growth</span> and precipitation variability across a large region of northwest Europe, although climate-<span class="hlt">growth</span> relationships appear time transgressive with correlations significantly weakening during the early twentieth century. Examination of the relationship between oak <span class="hlt">growth</span>, precipitation, and the North Atlantic Oscillation (NAO), reveals no evidence that the NAO plays any significant role in the control of precipitation or tree <span class="hlt">growth</span> in this region. Using Regional Curve Standardisation to preserve evidence of low-frequency <span class="hlt">growth</span> variability in the East Anglian oak chronology, we produce a millennial length reconstruction that is capable of explaining 32-35% of annual-to-decadal regional-scale precipitation variance during 1901-2009. The full length reconstruction indicates statistically significant anomalous dry conditions during AD 900-1100 and circa-1800. An apparent prolonged wetter phase is estimated for the twelfth and thirteen centuries, whilst precipitation fluctuates between wetter and drier phases at near centennial timescales throughout the fourteenth to seventeenth centuries. Above average precipitation reconstructed for the twenty-first century is comparable with that reproduced for the 1600s. The main estimated wet and dry phases reconstructed here appear largely coherent with an independent tree-<span class="hlt">ring</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005914','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005914"><span id="translatedtitle">Pulse <span class="hlt">width</span> modulation inverter with battery charger</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slicker, James M. (Inventor)</p> <p>1985-01-01</p> <p>An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse <span class="hlt">width</span> modulation techniques. In the disclosed method of pulse <span class="hlt">width</span> modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27505755','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27505755"><span id="translatedtitle">Optical antennas with sinusoidal modulation in <span class="hlt">width</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dikken, Dirk Jan; Segerink, Frans B; Korterik, Jeroen P; Pfaff, Stefan S; Prangsma, Jord C; Herek, Jennifer L</p> <p>2016-08-01</p> <p>Small metal structures sustaining plasmon resonances in the optical regime are of great interest due to their large scattering cross sections and ability to concentrate light to subwavelength volumes. In this paper, we study the dipolar plasmon resonances of optical antennas with a constant volume and a sinusoidal modulation in <span class="hlt">width</span>. We experimentally show that by changing the phase of the <span class="hlt">width</span>-modulation, with a small 10 nm modulation amplitude, the resonance shifts over 160 nm. Using simulations we show how this simple design can create resonance shifts greater than 600 nm. The versatility of this design is further shown by creating asymmetric structures with two different modulation amplitudes, which we experimentally and numerically show to give rise to two resonances. Our results on both the symmetric and asymmetric antennas show the capability to control the localization of the fields outside the antenna, while still maintaining the freedom to change the antenna resonance wavelength. The antenna design we tested combines a large spectral tunability with a small footprint: all the antenna dimensions are factor 7 to 13 smaller than the wavelength, and hold potential as a design element in meta-surfaces for beam shaping. PMID:27505755</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865303','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865303"><span id="translatedtitle">Pulse <span class="hlt">width</span> modulation inverter with battery charger</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Slicker, James M.</p> <p>1985-01-01</p> <p>An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse <span class="hlt">width</span> modulation techniques. In the disclosed method of pulse <span class="hlt">width</span> modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22730802M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22730802M"><span id="translatedtitle">Investigating Starburst Galaxy Emission Line Equivalent <span class="hlt">Widths</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meskhidze, Helen; Richardson, Chris T.</p> <p>2016-01-01</p> <p>Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent <span class="hlt">widths</span>. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent <span class="hlt">widths</span> of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961253','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961253"><span id="translatedtitle">Increased water use efficiency does not prevent <span class="hlt">growth</span> decline of Pinus canariensis in a semi-arid treeline ecotone in Tenerife, Canary Islands (Spain)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brito, Patricia; Grams, Thorsten E.E.; Matysssek, Rainer; Jimenez, Maria S.; Gonzalez-Rodríguez, Agueda M.; Oberhuber, Walter; Wieser, Gerhard</p> <p>2016-01-01</p> <p>Key message Intrinsic water-use efficiency of Pinus canariensis (Sweet ex Spreng.) growing at a semi-arid treeline has increased during the past 37 years. Tree-<span class="hlt">ring</span> <span class="hlt">width</span> by contrast has declined, likely caused by reduced stomatal conductance due to increasing aridity. Context Rising atmospheric CO2 concentration (Ca) has been related to tree <span class="hlt">growth</span> enhancement accompanied by increasing intrinsic water-use-efficiency (iWUE). Nevertheless, the extent of rising Ca on long-term changes in iWUE and <span class="hlt">growth</span> has remained poorly understood to date in Mediterranean treeline ecosystems. Aims This study aimed to examine radial <span class="hlt">growth</span> and physiological responses of P. canariensis in relation to rising Ca and increasing aridity at treeline in Tenerife, Canary Islands, Spain. Methods We evaluated temporal changes in secondary <span class="hlt">growth</span> (tree-<span class="hlt">ring</span> <span class="hlt">width</span>; TRW) and tree <span class="hlt">ring</span> stable C isotope signature for assessing iWUE from 1975 through 2011. Results Precipitation was the main factor controlling secondary <span class="hlt">growth</span>. Over the last 36 years P. canariensis showed a decline in TRW at enhanced iWUE, likely caused by reduced stomatal conductance due to increasing aridity. Conclusion Our results indicate that increasing aridity has overridden the potential CO2 fertilization on tree <span class="hlt">growth</span> of P. canariensis at its upper distribution limit. PMID:27482149</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/165371','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/165371"><span id="translatedtitle">Finite banana <span class="hlt">width</span> effect on magnetoacoustic cyclotron instability</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Y.P.; Tsai, S.T.</p> <p>1995-08-01</p> <p>The finite banana <span class="hlt">width</span> (FBW) effect on the coupling between magnetoacoustic waves and the near harmonic gyro-oscillations of the energetic ions/{alpha} particles in tokamaks are studied. The gyrokinetic equation with FBW effect is rederived for the energetic trapped ions. The dispersion relation and <span class="hlt">growth</span> rate of the magnetoacoustic cyclotron instability (MACI) are obtained. It is found that the coherence interaction between the energetic ion trajectory and mode field has a significant effect when the Larmor radius of energetic ions is larger than the wavelength of MACI. Near the low field side the FBW effect destabilizes the mode, while away from it the FBW gives a stabilizing effect. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830059291&hterms=Chestnut&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DChestnut','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830059291&hterms=Chestnut&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DChestnut"><span id="translatedtitle">Finite-<span class="hlt">width</span> currents, magnetic shear, and the current-driven ion-cyclotron instability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bakshi, P.; Ganguli, G.; Palmadesso, P.</p> <p>1983-01-01</p> <p>Our earlier results that non-local effects due to even a small magnetic shear produce a significant reduction of the <span class="hlt">growth</span> rate of the ion cyclotron instability driven by a uniform current are now generalized to finite <span class="hlt">width</span> currents. Externally prescribed as well as self-consistent shears are considered. If the current <span class="hlt">width</span> Lc exceeds the shear length Ls, the previous results are recovered. Shear becomes less effective with reduction of Lc, and for typical parameters, the <span class="hlt">growth</span> rate attains its (shearless) local value for Lc/Ls approximately less than 10 to the minus 2. Non-local effects of the finite current <span class="hlt">width</span> itself come into play if Lc is further reduced to a few ion Larmor radii and can quench the instability. Previously announced in STAR as N83-28996</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19590897','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19590897"><span id="translatedtitle">Do centennial tree-<span class="hlt">ring</span> and stable isotope trends of Larix gmelinii (Rupr.) Rupr. indicate increasing water shortage in the Siberian north?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sidorova, Olga Vladimirovna; Siegwolf, Rolf T W; Saurer, Matthias; Shashkin, Alexander V; Knorre, Anastasia A; Prokushkin, Anatoliy S; Vaganov, Eugene A; Kirdyanov, Alexander V</p> <p>2009-10-01</p> <p>Tree-<span class="hlt">ring</span> <span class="hlt">width</span> of Larix gmelinii (Rupr.) Rupr., ratios of stable isotopes of C (delta(13)C) and O (delta(18)O) of whole wood and cellulose chronologies were obtained for the northern part of central Siberia (Tura, Russia) for the period 1864-2006. A strong decrease in the isotope ratios of O and C (after atmospheric delta(13)C corrections) and tree-<span class="hlt">ring</span> <span class="hlt">width</span> was observed for the period 1967-2005, while weather station data show a decrease in July precipitation, along with increasing July air temperature and vapor pressure deficit (VPD). Temperature at the end of May and the whole month of June mainly determines tree radial <span class="hlt">growth</span> and marks the beginning of the vegetation period in this region. A positive correlation between tree-<span class="hlt">ring</span> <span class="hlt">width</span> and July precipitation was found for the calibration period 1929-2005. Positive significant correlations between C isotope chronologies and temperatures of June and July were found for whole wood and cellulose and negative relationships with July precipitation. These relationships are strengthened when the likely physiological response of trees to increased CO(2) is taken into account (by applying a recently developed delta(13)C correction). For the O isotope ratios, positive relationships with annual temperature, VPD of July and a negative correlation with annual precipitation were observed. The delta(18)O in tree <span class="hlt">rings</span> may reflect annual rather than summer temperatures, due to the late melting of the winter snow and its contribution to the tree water supply in summer. We observed a clear change in the isotope and climate trends after the 1960s, resulting in a drastic change in the relationship between C and O isotope ratios from a negative to a positive correlation. According to isotope fractionation models, this indicates reduced stomatal conductance at a relatively constant photosynthetic rate, as a response of trees to water deficit for the last half century in this permafrost region. PMID:19590897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870047611&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870047611&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Features in Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esposito, Larry W.; Harris, Craig C.; Simmons, Karen E.</p> <p>1987-01-01</p> <p>A systematic, uniform search of Voyage 2 photopolarimeter system (PSS) data set for all significant features of Saturn's <span class="hlt">rings</span> is described. On August 25, 1981, the PSS observed the occultation of the star Delta Scorpii by the <span class="hlt">rings</span> of Saturn, and the timing of the data taking was rapid enough that the spatial resolution in the radial direction in the <span class="hlt">ring</span> plane was better than 100 m. Tabular information and figures for 216 significant features that were found are presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6508834','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6508834"><span id="translatedtitle">Radioactive gold <span class="hlt">ring</span> dermatitis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miller, R.A.; Aldrich, J.E. )</p> <p>1990-08-01</p> <p>A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold <span class="hlt">ring</span> for more than 30 years. Only part of the <span class="hlt">ring</span> was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding <span class="hlt">ring</span> for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA00658&hterms=Halo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHalo','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA00658&hterms=Halo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHalo"><span id="translatedtitle">Jupiter's <span class="hlt">Ring</span> Halo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the <span class="hlt">rings</span>; however, because the spacecraft was only about 0.5 degrees above the <span class="hlt">ring</span> plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the <span class="hlt">ring</span> was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The <span class="hlt">ring</span> also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.<p/>Jupiter's <span class="hlt">ring</span> system is composed of three parts -- a flat main <span class="hlt">ring</span>, a lenticular halo interior to the main <span class="hlt">ring</span>, and the gossamer <span class="hlt">ring</span>, which lies exterior to the main <span class="hlt">ring</span>. The near and far arms of Jupiter's main <span class="hlt">ring</span> extend horizontally across the mosaic, joining together at the <span class="hlt">ring</span>'s ansa, on the far left side of the figure. The near arm of the <span class="hlt">ring</span> appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.<p/>A faint mist of particles can be seen above and below the main <span class="hlt">rings</span>; this vertically extended, toroidal 'halo' is unusual in planetary <span class="hlt">rings</span>, and is probably caused by electromagnetic forces which can push small grains out of the <span class="hlt">ring</span> plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the <span class="hlt">ring</span> plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988IPOpt.135...17J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988IPOpt.135...17J"><span id="translatedtitle">Integrated semiconductor <span class="hlt">ring</span> lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jezierski, A. F.; Laybourn, P. J. R.</p> <p>1988-02-01</p> <p><span class="hlt">Ring</span>-waveguide and pill-box structures down to 12 microns in diameter, made in GaAs/GaAlAs heterostructure material, have been designed with output stripe waveguides coupled to the <span class="hlt">rings</span> via Y-junctions. The waveguides were defined by reactive ion etching, although the inner boundaries of some of the <span class="hlt">ring</span> waveguides relied on stress and carrier confinement. Lasing has been observed with pulsed drive current, and has been shown to correspond to resonances in the <span class="hlt">rings</span>, although other resonances have been observed in some of the structures. This type of structure is suitable for use as a light source in monolithic integrated optics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850018196&hterms=Kinematic+viscosity&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKinematic%2Bviscosity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850018196&hterms=Kinematic+viscosity&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKinematic%2Bviscosity"><span id="translatedtitle">Viscosity in Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lissauer, J. J.; Shu, F. H.; Cuzzi, J. N.</p> <p>1982-01-01</p> <p>The technique of estimating the viscosity in Saturn's <span class="hlt">rings</span> from the damping rate of waves observed to be propagating within the <span class="hlt">rings</span> is discussed. The wavetrains of attempts using spiral density waves as a diagnostic suffer significant complications that compromise the interpretations. A method that considers the damping of spiral bending waves was used to deduce a kinematic viscosity of 260 (+150, -100) sqcm/sec for the middle of the A <span class="hlt">ring</span> where bending waves are excited by the 5:3 vertical resonance with Mimas. This value implies upper limits on the particle velocity dispersion and local <span class="hlt">ring</span> thickness of 0.4 cm/sec and 30 m, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996DPS....28.1814M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996DPS....28.1814M"><span id="translatedtitle">Hydrodynamical Simulations of the Uranian <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mosqueira, I.; Estrada, P. R.; Brookshaw, L.</p> <p>1996-09-01</p> <p>We investigate the global dynamics of the Uranian <span class="hlt">rings</span> using a modified 2-D smoothed particle hydrodynamic code combined with a 2-D tree code used to compute the particle-to-particle gravitational interactions. This code includes epicyclic fluid motion, non-axisymmetric flow, local and non-local shear viscocity, self-consistent scale height evolution, <span class="hlt">ring</span>-satellites gravitational interaction and co-evolution, and <span class="hlt">ring</span> self-gravity. To follow the scale height of each particle we solve the vertical momentum equation for the flow using a Runge-Kutta scheme with a second order polynomial fit to the vertical behavior of the fluid pressure (Borderies, Goldreich, and Tremaine 1985. Icarus, 63, 406). The behavior of the fluid viscocity is obtained from Mosqueira (1996. Icarus, 122, 128) who found good agreement between an extension to the non-local viscocity model of Borderies, Goldreich, and Tremaine (1985) that includes local terms with the results of a local patch-code <span class="hlt">ring</span> simulation. Our present viscocity model incorporates further terms which account for the epicyclic limit to the mean free path (Goldreich and Tremaine 1978. Icarus, 34, 227). This treatment covers both the high and low <span class="hlt">ring</span> density regimes. Our approach treats the fluid work terms and internal energy self-consistently even in the presence of a non-zero divergence of the fluid velocity. Even within a 2-D framework the Uranian <span class="hlt">rings</span> are so thin compared to their semi-major axes that radial resolution requires too many particles given our present computer resources. To address this issue we have developed a physical scaling that reduces the semi-major axis of the <span class="hlt">ring</span> while preserving its <span class="hlt">width</span> and, we believe, retains the relevant global satellite-<span class="hlt">ring</span> dynamics. With a conservative value of the scaling parameter that reduces the <span class="hlt">ring</span>'s semi-major axis by a factor of 10, our scaling allows for savings between a factor of 20 in the case of synodic time scales, a factor of 200 for shear timescales, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/965910','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/965910"><span id="translatedtitle">Direct measurement of the W boson <span class="hlt">width</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; /Michigan U. /Northeastern U.</p> <p>2009-09-01</p> <p>We present a direct measurement of the <span class="hlt">width</span> of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27303421','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27303421"><span id="translatedtitle">Missing <span class="hlt">Rings</span> in Pinus halepensis - The Missing Link to Relate the Tree-<span class="hlt">Ring</span> Record to Extreme Climatic Events.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T</p> <p>2016-01-01</p> <p>Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree <span class="hlt">growth</span> and increased vulnerability to pests and diseases. The anatomy of tree <span class="hlt">rings</span> responds to these environmental conditions. Quantitatively, the <span class="hlt">width</span> of a tree <span class="hlt">ring</span> is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing <span class="hlt">ring</span> (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree <span class="hlt">rings</span> throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4885872','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4885872"><span id="translatedtitle">Missing <span class="hlt">Rings</span> in Pinus halepensis – The Missing Link to Relate the Tree-<span class="hlt">Ring</span> Record to Extreme Climatic Events</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Novak, Klemen; de Luis, Martin; Saz, Miguel A.; Longares, Luis A.; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B. K.; Papadopoulos, Andreas; Smith, Kevin T.</p> <p>2016-01-01</p> <p>Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree <span class="hlt">growth</span> and increased vulnerability to pests and diseases. The anatomy of tree <span class="hlt">rings</span> responds to these environmental conditions. Quantitatively, the <span class="hlt">width</span> of a tree <span class="hlt">ring</span> is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing <span class="hlt">ring</span> (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree <span class="hlt">rings</span> throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016QSRv..142..164K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016QSRv..142..164K&link_type=ABSTRACT"><span id="translatedtitle">Climate signal age effects in boreal tree-<span class="hlt">rings</span>: Lessons to be learned for paleoclimatic reconstructions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konter, Oliver; Büntgen, Ulf; Carrer, Marco; Timonen, Mauri; Esper, Jan</p> <p>2016-06-01</p> <p>Age-related alternation in the sensitivity of tree-<span class="hlt">ring</span> <span class="hlt">width</span> (TRW) to climate variability has been reported for different forest species and environments. The resulting <span class="hlt">growth</span>-climate response patterns are, however, often inconsistent and similar assessments using maximum latewood density (MXD) are still missing. Here, we analyze climate signal age effects (CSAE, age-related changes in the climate sensitivity of tree <span class="hlt">growth</span>) in a newly aggregated network of 692 Pinus sylvestris L. TRW and MXD series from northern Fennoscandia. Although summer temperature sensitivity of TRW (rAll = 0.48) ranges below that of MXD (rAll = 0.76), it declines for both parameters as cambial age increases. Assessment of CSAE for individual series further reveals decreasing correlation values as a function of time. This declining signal strength remains temporally robust and negative for MXD, while age-related trends in TRW exhibit resilient meanderings of positive and negative trends. Although CSAE are significant and temporally variable in both tree-<span class="hlt">ring</span> parameters, MXD is more suitable for the development of climate reconstructions. Our results indicate that sampling of young and old trees, and testing for CSAE, should become routine for TRW and MXD data prior to any paleoclimatic endeavor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100005268','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100005268"><span id="translatedtitle">High-Speed <span class="hlt">Ring</span> Bus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry</p> <p>2010-01-01</p> <p>The high-speed <span class="hlt">ring</span> bus at the Jet Propulsion Laboratory (JPL) allows for future <span class="hlt">growth</span> trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the <span class="hlt">ring</span>. The JPL <span class="hlt">ring</span> bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel <span class="hlt">Ring</span> Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 <span class="hlt">Ring</span> Bus. Data transfer on the <span class="hlt">ring</span> bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the <span class="hlt">ring</span> whenever it has data received from its host. There</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016DDA....4730002H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016DDA....4730002H&link_type=ABSTRACT"><span id="translatedtitle">Keeping the Edges Sharp I: Honing the Theory of Narrow <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamilton, Douglas P.; Rimlinger, Thomas; Hahn, Joseph M.</p> <p>2016-05-01</p> <p>Most of the <span class="hlt">rings</span> that encircle Saturn, Uranus, and Neptune are very narrow structures with typical radial <span class="hlt">widths</span> of just a few kilometers. Such extreme sharpness is surprising, as even slightly different orbital periods should allow <span class="hlt">ring</span> particles to continually jostle one another in collisions that preserve angular momentum whileinexorably draining energy. Sharp edges should blur as <span class="hlt">rings</span> spread in response to collisions and yet they do not. The generally accepted solution to this dilemma is to bracket each narrow <span class="hlt">ring</span> with a pair of shepherding satellites that can pump energy back into the <span class="hlt">ring</span> to replace that lost by collisions. But only a disappointing two of roughly twenty narrow <span class="hlt">rings</span> actually have known attendant satellites. We present a compelling alternative in which the slight eccentricities and inclinations of narrow ringlets act as internal energy sources that can be tapped to prevent <span class="hlt">ring</span> spreading. When unattended circular <span class="hlt">rings</span> dissipate energy they must spread radially in order to preserve angular momentum. By contrast, eccentric or inclined <span class="hlt">rings</span> have an extra degree of freedom that can be exploited to prevent radial spreading; energy is dissipated while keeping z-component of angular momentum, sqrt(a(1-e^2))cos(i), constant by simply decreasing the overall eccentricity (e) and/or inclination (i) of the entire <span class="hlt">ring</span>. A real narrow <span class="hlt">ring</span> moves inward as a unit, circularizes, and drops into the equatorial plane in a process that deters radial spreading for millions or billions of years. Using secular theory with dissipation (Zhang et al. 2013), we show that narrow <span class="hlt">rings</span> are secular eigenstates in which ellipses are nested with pericenters almost, but not exactly aligned. The misalignment of pericenters is crucial in allowing energy dissipation to be shared evenly across the <span class="hlt">ring</span>. We predict <span class="hlt">ring</span> surface densities that are roughly constant across the <span class="hlt">ring</span>'s <span class="hlt">width</span>, in contrast to profiles expected for shepherded <span class="hlt">rings</span>. Rimlinger et al. (this meeting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GPN-2000-000944&hterms=Wisconsin+Madison&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DWisconsin%2BMadison','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GPN-2000-000944&hterms=Wisconsin+Madison&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DWisconsin%2BMadison"><span id="translatedtitle"><span class="hlt">Ring</span> Around a Galaxy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p>Space Telescope Science Institute astronomers are giving the public chances to decide where to aim NASA's Hubble Space Telescope. Guided by 8,000 Internet voters, Hubble has already been used to take a close-up, multi-color picture of the most popular object from a list of candidates, the extraordinary 'polar-<span class="hlt">ring</span>' galaxy NGC 4650A. Located about 130 million light-years away, NGC 4650A is one of only 100 known polar-<span class="hlt">ring</span> galaxies. Their unusual disk-<span class="hlt">ring</span> structure is not yet understood fully. One possibility is that polar <span class="hlt">rings</span> are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. What is left of one galaxy has become the rotating inner disk of old red stars in the center. Meanwhile, another smaller galaxy which ventured too close was probably severely damaged or destroyed. The bright bluish clumps, which are especially prominent in the outer parts of the <span class="hlt">ring</span>, are regions containing luminous young stars, examples of stellar rebirth from the remnants of an ancient galactic disaster. The polar <span class="hlt">ring</span> appears to be highly distorted. No regular spiral pattern stands out in the main part of the <span class="hlt">ring</span>, and the presence of young stars below the main <span class="hlt">ring</span> on one side and above on the other shows that the <span class="hlt">ring</span> is warped and does not lie in one plane. Determining the typical ages of the stars in the polar <span class="hlt">ring</span> is an initial goal of our Polar <span class="hlt">Ring</span> Science Team that can provide a clue to the evolution of this unusual galaxy. The HST exposures were acquired by the Hubble Heritage Team, consisting of Keith Noll, Howard Bond, Carol Christian, Jayanne English, Lisa Frattare, Forrest Hamilton, Anne Kinney and Zolt Levay, and guest collaborators Jay Gallagher (University of Wisconsin-Madison), Lynn Matthews (National Radio Astronomy Observatory-Charlottesville), and Linda Sparke (University of Wisconsin-Madison).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DDA....4730001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DDA....4730001L"><span id="translatedtitle">Planetary <span class="hlt">rings</span> and astrophysical discs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Latter, Henrik</p> <p>2016-05-01</p> <p>Disks are ubiquitous in astrophysics and participate in some of its most important processes. Of special interest is their role in star, planet and moon formation, the <span class="hlt">growth</span> of supermassive black holes, and the launching of jets. Although astrophysical disks can be up to ten orders of magnitude larger than planetary <span class="hlt">rings</span> and differ hugely in composition, all disks share to some extent the same basic dynamics and many physical phenomena. This review explores these areas of overlap. Topics covered include disk formation, accretion, collisions, instabilities, and satellite-disk interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....12.5871B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....12.5871B"><span id="translatedtitle">Influence of wood density in tree-<span class="hlt">ring</span> based annual productivity assessments and its errors in Norway spruce</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bouriaud, O.; Teodosiu, M.; Kirdyanov, A. V.; Wirth, C.</p> <p>2015-04-01</p> <p>Estimations of tree annual biomass increments are used by a variety of studies related to forest productivity or carbon fluxes. Biomass increment estimations can be easily obtained from diameter surveys or historical diameter reconstructions based on tree <span class="hlt">rings</span> records. However, the biomass models rely on the assumption of a constant wood density. Converting volume increment into biomass also requires assumptions on the wood density. Wood density has been largely reported to vary both in time and between trees. In Norway spruce, wood density is known to increase with decreasing <span class="hlt">ring</span> <span class="hlt">width</span>. This could lead to underestimating the biomass or carbon deposition in bad years. The variations between trees of wood density has never been discussed but could also contribute to deviations. A modelling approach could attenuate these effects but will also generate errors. Here were developed a model of wood density variations in Norway spruce, and an allometric model of volume <span class="hlt">growth</span>. We accounted for variations in wood density both between years and between trees, based on specific measurements. We compared the effects of neglecting each variation source on the estimations of annual biomass increment. We also assessed the errors of the biomass increment predictions at tree level, and of the annual productivity at plot level. Our results showed a partial compensation of the decrease in <span class="hlt">ring</span> <span class="hlt">width</span> in bad years by the increase in wood density. The underestimation of the biomass increment in those years reached 15%. The errors related to the use of an allometric model of volume <span class="hlt">growth</span> were modest, around ±15%. The errors related to variations in wood density were much larger, the biggest component being the inter-tree variability. The errors in plot-level annual biomass productivity reached up to 40%, with a full account of all the error sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGeo...12.6205B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGeo...12.6205B"><span id="translatedtitle">Influence of wood density in tree-<span class="hlt">ring</span>-based annual productivity assessments and its errors in Norway spruce</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bouriaud, O.; Teodosiu, M.; Kirdyanov, A. V.; Wirth, C.</p> <p>2015-10-01</p> <p>Estimations of tree annual biomass increments are used by a variety of studies related to forest productivity or carbon fluxes. Biomass increment estimations can be easily obtained from diameter surveys or historical diameter reconstructions based on tree <span class="hlt">rings</span>' records. However, the biomass models rely on the assumption that wood density is constant. Converting volume increment into biomass also requires assumptions about the wood density. Wood density has been largely reported to vary both in time and between trees. In Norway spruce, wood density is known to increase with decreasing <span class="hlt">ring</span> <span class="hlt">width</span>. This could lead to underestimating the biomass or carbon deposition in bad years. The variations between trees of wood density have never been discussed but could also contribute to deviations. A modelling approach could attenuate these effects but will also generate errors. Here a model of wood density variations in Norway spruce, and an allometric model of volume <span class="hlt">growth</span> were developed. We accounted for variations in wood density both between years and between trees, based on specific measurements. We compared the effects of neglecting each variation source on the estimations of annual biomass increment. We also assessed the errors of the biomass increment predictions at tree level, and of the annual productivity at plot level. Our results showed a partial compensation of the decrease in <span class="hlt">ring</span> <span class="hlt">width</span> in bad years by the increase in wood density. The underestimation of the biomass increment in those years reached 15 %. The errors related to the use of an allometric model of volume <span class="hlt">growth</span> were modest, around ±15 %. The errors related to variations in wood density were much larger, the biggest component being the inter-tree variability. The errors in plot-level annual biomass productivity reached up to 40 %, with a full account of all the error sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870656','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870656"><span id="translatedtitle">Apparatus for controlling the scan <span class="hlt">width</span> of a scanning laser beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Johnson, Gary W.</p> <p>1996-01-01</p> <p>Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan <span class="hlt">width</span>). A system has been demonstrated whereby the scan <span class="hlt">width</span> of a swept <span class="hlt">ring</span>-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/392656','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/392656"><span id="translatedtitle">Apparatus for controlling the scan <span class="hlt">width</span> of a scanning laser beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Johnson, G.W.</p> <p>1996-10-22</p> <p>Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan <span class="hlt">width</span>). A system has been demonstrated whereby the scan <span class="hlt">width</span> of a swept <span class="hlt">ring</span>-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board. 8 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015LaPhL..12e5802W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015LaPhL..12e5802W"><span id="translatedtitle">Low intensity noise and narrow line-<span class="hlt">width</span> diode laser light at 540 nm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Lirong; Tamaki, Ryo; Kasai, Katsuyuki; Okada-Shudo, Yoshiko; Watanabe, Masayoshi; Zhang, Yun</p> <p>2015-05-01</p> <p>We present a convenient method to generate high quality single-frequency green light at a wavelength of 540 nm. It consists of a noise suppressed external cavity diode laser at a wavelength of 1080 nm by optical filtering and resonant optical feedback, and a frequency doubling of the fundamental light with an a-cut KTP crystal. Highly efficient conversion is realized by type II non-critical phase matching. A stable single-frequency operation with a maximum power of about 20 mW is performed for more than 3 h. Both the intensity noise and line-<span class="hlt">width</span> reach the level of a monolithic nonplanar <span class="hlt">ring</span> laser, which is well known for its extraordinarily narrow line-<span class="hlt">width</span> and extremely low noise among available single-frequency operating lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20777076','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20777076"><span id="translatedtitle">Dielectron <span class="hlt">Widths</span> of the {upsilon}(1S,2S,3S) Resonances</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rosner, J.L.; Adam, N.E.; Alexander, J.P.; Berkelman, K.; Cassel, D.G.; Duboscq, J.E.; Ecklund, K.M.; Ehrlich, R.; Fields, L.; Galik, R.S.; Gibbons, L.; Gray, R.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Hertz, D.; Jones, C.D.; Kandaswamy, J.; Kreinick, D.L.; Kuznetsov, V.E.</p> <p>2006-03-10</p> <p>We determine the dielectron <span class="hlt">widths</span> of the {upsilon}(1S), {upsilon}(2S), and {upsilon}(3S) resonances with better than 2% precision by integrating the cross section of e{sup +}e{sup -}{yields}{upsilon} over the e{sup +}e{sup -} center-of-mass energy. Using e{sup +}e{sup -} energy scans of the {upsilon} resonances at the Cornell Electron Storage <span class="hlt">Ring</span> and measuring {upsilon} production with the CLEO detector, we find dielectron <span class="hlt">widths</span> of 1.252{+-}0.004({sigma}{sub stat}){+-}0.019({sigma}{sub syst}) keV, 0.581{+-}0.004{+-}0.009 keV, and 0.413{+-}0.004{+-}0.006 keV for the {upsilon}(1S), {upsilon}(2S), and {upsilon}(3S), respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MAR.T8009L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MAR.T8009L&link_type=ABSTRACT"><span id="translatedtitle">The Aharonov-Bohm effect in Möbius <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Zehao; Ram-Mohan, L.; CenterComputational NanoScience Team</p> <p>2013-03-01</p> <p>Electron transmission through finite-<span class="hlt">width</span> 2D <span class="hlt">ring</span> structures is calculated for cylindrical, flat (Aharonov-Bohm), and Möbius <span class="hlt">rings</span>. In the presence of an external magnetic field, curves of constructive transmission display a pattern similar to that for a 1D <span class="hlt">ring</span>. The periodicity in the magnetic flux, in units of h / e , is weakly broken on 2D <span class="hlt">rings</span> of finite <span class="hlt">width</span>, so that a description with a 1D-path is very acceptable. The unusual states with half-integer values of <Lz > observed on Möbius <span class="hlt">rings</span>, display a different characteristic in transmission. Such resonant states are in constructive interference for transmission at magnetic fields where the contribution from ordinary states with integer <Lz > is in destructive interference, and vice versa. This leads to an alternating dominance of the set of half-integer <Lz > states and the set of integer <Lz > states in transport with increasing magnetic fields. We anticipate that Möbius <span class="hlt">rings</span> would be synthesized with graphene ribbons in the near future. Z.L. acknowledges support from a Presidents Undergraduate Fellowship and a Summer Undergraduate Research Fellowship at WPI.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22410432','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22410432"><span id="translatedtitle">Linear dispersion properties of <span class="hlt">ring</span> velocity distribution functions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vandas, Marek</p> <p>2015-06-15</p> <p>Linear properties of <span class="hlt">ring</span> velocity distribution functions are investigated. The dispersion tensor in a form similar to the case of a Maxwellian distribution function, but for a general distribution function separable in velocities, is presented. Analytical forms of the dispersion tensor are derived for two cases of <span class="hlt">ring</span> velocity distribution functions: one obtained from physical arguments and one for the usual, ad hoc <span class="hlt">ring</span> distribution. The analytical expressions involve generalized hypergeometric, Kampé de Fériet functions of two arguments. For a set of plasma parameters, the two <span class="hlt">ring</span> distribution functions are compared. At the parallel propagation with respect to the ambient magnetic field, the two <span class="hlt">ring</span> distributions give the same results identical to the corresponding bi-Maxwellian distribution. At oblique propagation, the two <span class="hlt">ring</span> distributions give similar results only for strong instabilities, whereas for weak <span class="hlt">growth</span> rates their predictions are significantly different; the two <span class="hlt">ring</span> distributions have different marginal stability conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012DPS....4450103M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012DPS....4450103M"><span id="translatedtitle">Particle Size Distribution in Saturn’s <span class="hlt">Ring</span> C</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marouf, Essam A.; Wong, K.; French, R.; Rappaport, N.</p> <p>2012-10-01</p> <p>Information about particle sizes in Saturn’s <span class="hlt">rings</span> is provided by two complementary types of Cassini radio occultation measurements. The first is differential extinction of three coherent sinusoidal signals transmitted by Cassini through the <span class="hlt">rings</span> back to Earth (wavelength = 0.94, 3.6, and 13 cm, respectively). The differential measurements strongly constraint three parameters of an assumed power-law size distribution n(a) = n0 (a/a0)q, amin ≤ a ≤ amax: namely, the power law index q, the minimum radius amin, and reference abundance n0 at reference radius a0. The differential measurements are particularly sensitive to radii in the range 0.1 mm < a < 1 m. Complementing this capability, is a second type of measurements that is particularly sensitive to the larger radii 1 m < a < 20 m and their abundance. Signature of the collective near-forward scattering by these particles is captured in power spectrum measurements as broadened component of <span class="hlt">width</span>, shape, and strength that depend on <span class="hlt">ring</span> particle sizes, their spatial distribution, and observation geometry. Contributions of <span class="hlt">ring</span> features of <span class="hlt">width</span> as small several hundred kilometers can be identified and isolated in the measured spectra for a small subset of Cassini orbits of favorable geometry. We use three inverse scattering algorithms (Bayes, constrained linear inversion, generalized singular-value-decomposition) to recover the size distribution of particles of resolved <span class="hlt">ring</span> features over the size range 1 m < a < 20 m without assuming an explicit size distribution model. We also investigate consistency of the results with a single power-law model extending over 0.1 mm < a < 20 m and implications to the spatial distribution of <span class="hlt">ring</span> particles normal to the <span class="hlt">ring</span> plane (vertical <span class="hlt">ring</span> thickness). We present example results for selected features across Saturn’s <span class="hlt">Ring</span> C where little evidence for gravitational wakes is present, hence the approaches above are applicable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6597278','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6597278"><span id="translatedtitle">Profiling Saturn's <span class="hlt">rings</span> by radio occultation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marouf, E.A.; Tyler, G.L.; Rosen, P.A.</p> <p>1986-10-01</p> <p>The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the <span class="hlt">rings</span> is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment <span class="hlt">width</span>, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's <span class="hlt">rings</span> derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented. 35 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870034958&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870034958&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Profiling Saturn's <span class="hlt">rings</span> by radio occultation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marouf, Essam A.; Tyler, G. Leonard; Rosen, Paul A.</p> <p>1986-01-01</p> <p>The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the <span class="hlt">rings</span> is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment <span class="hlt">width</span>, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's <span class="hlt">rings</span> derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=tornado&id=EJ945886','ERIC'); return false;" href="http://eric.ed.gov/?q=tornado&id=EJ945886"><span id="translatedtitle">Smoke <span class="hlt">Ring</span> Physics</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Huggins, Elisha</p> <p>2011-01-01</p> <p>The behavior of smoke <span class="hlt">rings</span>, tornados, and quantized vortex <span class="hlt">rings</span> in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=MSFC-0400741&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=MSFC-0400741&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Illustration of Saturn's <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2001-01-01</p> <p>This illustration shows a close-up of Saturn's <span class="hlt">rings</span>. These <span class="hlt">rings</span> are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/000208.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/000208.htm"><span id="translatedtitle">Lower esophageal <span class="hlt">ring</span> (Schatzki)</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... narrowed area to stretch the <span class="hlt">ring</span>. Sometimes, a balloon is placed in the area and inflated, to help widen the <span class="hlt">ring</span>. Outlook (Prognosis) Swallowing problems may return. You may need repeat treatment. When to Contact a Medical Professional Call your health care provider if you ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5516258','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5516258"><span id="translatedtitle">EBT <span class="hlt">ring</span> physics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Uckan, N.A.</p> <p>1980-04-01</p> <p>This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron <span class="hlt">ring</span> properties. The dominant physical processes that influence <span class="hlt">ring</span> formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980203175','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980203175"><span id="translatedtitle">Contactless Magnetic Slip <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kumagai, Hiroyuki (Inventor); Deardon, Joe D. (Inventor)</p> <p>1997-01-01</p> <p>A contactless magnetic slip <span class="hlt">ring</span> is disclosed having a primary coil and a secondary coil. The primary and secondary coils are preferably magnetically coupled together, in a highly reliable efficient manner, by a magnetic layered core. One of the secondary and primary coils is rotatable and the contactless magnetic slip <span class="hlt">ring</span> provides a substantially constant output.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/783204','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/783204"><span id="translatedtitle">The Fermilab recycler <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martin Hu</p> <p>2001-07-24</p> <p>The Fermilab Recycler is a permanent magnet storage <span class="hlt">ring</span> for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler <span class="hlt">Ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19670000055','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19670000055"><span id="translatedtitle">Circuit multiplies pulse <span class="hlt">width</span> modulation, exhibits linear transfer function</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carlson, A. W.; Furciniti, A.</p> <p>1967-01-01</p> <p>Modulation multiplier provides a simple means of multiplying the <span class="hlt">width</span> modulation of a pulse train by a constant factor. It operates directly on a pulse <span class="hlt">width</span> modulated input signal to generate an output pulse train having a greater degree of <span class="hlt">width</span> modulation than the input signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JCrGr.213..389R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JCrGr.213..389R"><span id="translatedtitle">Effect of EDTA on the metastable zone <span class="hlt">width</span> of ADP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajesh, N. P.; Meera, K.; Srinivasan, K.; Santhana Raghavan, P.; Ramasamy, P.</p> <p>2000-06-01</p> <p>Enhancement of the metastable zone <span class="hlt">width</span> in ammonium dihydrogen ortho phosphate (ADP) was achieved by the addition of 1 mol% of the chelating agent ethylenediaminetetra acetic acid (EDTA) to ADP solution. The metastable zone <span class="hlt">width</span> studies were conducted and the nucleation parameters were calculated from the measurements of the dependence of the metastable zone <span class="hlt">width</span> on the cooling rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003DPS....35.1109H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003DPS....35.1109H"><span id="translatedtitle">Jupiter's Gossamer <span class="hlt">Rings</span> Explained.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamilton, D. P.</p> <p>2003-05-01</p> <p>Over the past several years, Galileo measurements and groundbased imaging have drastically improved our knowledge of Jupiter's faint <span class="hlt">ring</span> system. We now recognize that the <span class="hlt">ring</span> consists of four components: a main <span class="hlt">ring</span> 7000km wide, whose inner edge blossoms into a vertically-extended halo, and a pair of more tenuous Gossamer <span class="hlt">rings</span>, one associated with each of the small moons Thebe and Amalthea. When viewed edge on, the Gossamer <span class="hlt">rings</span> appear as diaphanous disks whose thicknesses agree with the vertical excursions of the inclined satellites from the equatorial plane. In addition, the brightness of each Gossamer <span class="hlt">ring</span> drops off sharply outside the satellite orbits. These correlations allowed Burns etal (1999, Science, 284, 1146) to argue convincingly that the satellites act as sources of the dusty <span class="hlt">ring</span> material. In addition, since most material is seen inside the orbits of the source satellites, an inwardly-acting dissipative force such as Poynting-Robertson drag is implicated. The most serious problem with this simple and elegant picture is that it is unable to explain the existence of a faint swath of material that extends half a jovian radius outward from Thebe. A key constraint is that this material has the same thickness as the rest of the Thebe <span class="hlt">ring</span>. In this work, we identify the mechanism responsible for the outward extension: it is a shadow resonance, first investigated by Horanyi and Burns (1991, JGR, 96, 19283). When a dust grain enters Jupiter's shadow, photoelectric processes shut down and the grain's electric charge becomes more negative. The electromagnetic forces associated with the varying charge cause periodic oscillations in the orbital eccentricity and semimajor axis as the orbital pericenter precesses. This results in a <span class="hlt">ring</span> which spreads both inward and outward of its source satellite while preserving its vertical thickness - just as is observed for the Thebe <span class="hlt">ring</span>. Predictions of the model are: i) gaps of micron-sized material interior to Thebe and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA09342&hterms=Charcoal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCharcoal','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA09342&hterms=Charcoal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCharcoal"><span id="translatedtitle">Jupiter's <span class="hlt">Rings</span>: Sharpest View</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p><p/> The New Horizons spacecraft took the best images of Jupiter's charcoal-black <span class="hlt">rings</span> as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the <span class="hlt">rings</span>, as well as lesser amounts of material between the <span class="hlt">rings</span>. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the <span class="hlt">rings</span>. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow <span class="hlt">rings</span> are confined in their orbits by small 'shepherding' moons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9292E..35A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9292E..35A"><span id="translatedtitle">Climatic response of annual tree-<span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ageev, Boris G.; Gruzdev, Aleksandr N.; Ponomarev, Yurii N.; Sapozhnikova, Valeria A.</p> <p>2014-11-01</p> <p>Extensive literature devoted to investigations into the influence of environmental conditions on the plant respiration and respiration rate. It is generally accepted that the respired CO2 generated in a stem completely diffuses into the atmosphere. Results obtained from explorations into the CO2 content in disc tree <span class="hlt">rings</span> by the method proposed in this work shows that a major part of CO2 remains in tree stems and exhibits inter-annual variability. Different methods are used to describe of CO2 and H2O distributions in disc tree <span class="hlt">rings</span>. The relation of CO2 and H2O variations in a Siberian stone pine disc to meteorological parameters are analyzed with use of wavelet, spectral and cross-spectral techniques. According to a multiple linear regression model, the time evolution of the <span class="hlt">width</span> of Siberian stone pine <span class="hlt">rings</span> can be partly explained by a combined influence of air temperature, precipitation, cloudiness and solar activity. Conclusions are made regarding the response of the CO2 and H2O content in coniferous tree disc <span class="hlt">rings</span> to various climatic factors. Suggested method of CO2, (CO2+H2O) detection can be used for studying of a stem respiration in ecological risk areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70019476','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70019476"><span id="translatedtitle">Unraveling the strands of Saturn's F <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Murray, C.D.; Gordon, M.K.; Giuliatti, Winter S.M.</p> <p>1997-01-01</p> <p>Several high-resolution Voyager 2 images of Saturn's F <span class="hlt">ring</span> show that it is composed of at least four separate, non-intersecting strands extending ~45?? in longitude. Voyager 1 images show that the two brightest strands appear to intersect, giving rise to a "braided" morphology. From a study of all available Voyager images the detectable radial structure is cataloged and reviewed. Previous indications that there is fine material interior to the orbit of the F <span class="hlt">ring</span> are confirmed. Evidence is presented that a model of four strands with comparable eccentricities and nearly aligned perichrones is consistent with all the Voyager observations. The observed perichrone offset of the two brightest strands suggests a minimum radial separation of ~20 km, which implies intersection of these strands when their finite radial <span class="hlt">widths</span> are taken into account. The longitude range of such an intersection includes that observed in the Voyager 1 "braid" images. The proximity of these two strands at some longitudes may account for the apparent differences in the <span class="hlt">ring</span> between the Voyager encounters, as well as provide a source for the short-lived features detected in the Hubble Space Telescope images of the F <span class="hlt">ring</span>. There is no evidence that the locations of the individual strands are determined by resonant perturbations with known satellites. It is proposed that the radial structure is formed by the localized action of small satellites orbiting within the strand region. ?? 1997 Academic Press.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/tx1045.photos.203746p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/tx1045.photos.203746p/"><span id="translatedtitle">STEEL TRUSS TENSION <span class="hlt">RING</span> SUPPORTING DOME ROOF. TENSION <span class="hlt">RING</span> COVERED ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>STEEL TRUSS TENSION <span class="hlt">RING</span> SUPPORTING DOME ROOF. TENSION <span class="hlt">RING</span> COVERED BY ARCHITECTURAL FINISH. TENSION <span class="hlt">RING</span> ROLLER SUPPORT AT COLUMN OBSCURED BY COLUMN COVERINGS. - Houston Astrodome, 8400 Kirby Drive, Houston, Harris County, TX</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150487','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150487"><span id="translatedtitle">The Effects of Forming Parameters on Conical <span class="hlt">Ring</span> Rolling Process</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Meng, Wen; Zhao, Guoqun; Guan, Yanjin</p> <p>2014-01-01</p> <p>The plastic penetration condition and biting-in condition of a radial conical <span class="hlt">ring</span> rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of <span class="hlt">ring</span>'s outer radius <span class="hlt">growth</span> rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled <span class="hlt">ring</span> are larger than that at the middle layer of <span class="hlt">ring</span>; the temperatures at the “obtuse angle zone” of <span class="hlt">ring</span>'s cross-section are higher than those at “acute angle zone”; the temperature at the central part of <span class="hlt">ring</span> is higher than that at the middle part of <span class="hlt">ring</span>'s outer surfaces. As the <span class="hlt">ring</span>'s outer radius <span class="hlt">growth</span> rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the <span class="hlt">ring</span>'s outer radius <span class="hlt">growth</span> rate and rolls sizes were obtained. PMID:25202716</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950007224','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950007224"><span id="translatedtitle">AXAF VETA-I mirror <span class="hlt">ring</span> focus measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tananbaum, H. D.; Zhao, P.</p> <p>1994-01-01</p> <p>The AXAF VETA-I mirror <span class="hlt">ring</span> focus measurements were made with an HRI (microchannel plate) X-ray detector. The <span class="hlt">ring</span> focus is a sharply focused <span class="hlt">ring</span> formed by X-rays before they reach the VEAT-I focal plane. It is caused by spherical aberrations due to the finite source distance and the despace in the VETA-I test. The <span class="hlt">ring</span> focus test reveals some aspects fo the test system distortions and the mirror surface figure which are difficult or impossible to detect at the focal plane. The test results show periodic modulations of the <span class="hlt">ring</span> radius and <span class="hlt">width</span> which could be caused by gravity, thermal, and/or epoxy shrinkage distortions. The strongest component of the modulation had a 12-fold symmetry, because these distortions were exerted on the mirror through 12 flexures of the VETA-I mount. <span class="hlt">Ring</span> focus models were developed to simulate the <span class="hlt">ring</span> image. The models were compared with the data to understand the test system distortions and the mirror glass imperfection. Further studies will be done to complete this work. The <span class="hlt">ring</span> focus measurement is a very powerful test. We expect that a similar test for the finally assembled mirror of AXAD-I will be highly valuable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BlgAJ..19...72K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BlgAJ..19...72K"><span id="translatedtitle">Trees annual <span class="hlt">rings</span> and "Sun-Climate" connection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Komitov, Boris; Duchlev, Peter; Bjandov, Georgy; Kirilova, Daniela</p> <p></p> <p>The subject of the present work is an investigation of the relationship "Sun-Climate" for the territory of Central Bulgaria for the period from the end of 18th to the beginning of 21st century, based on dendro-chronoligical data. For this purpose the smoothed time series of the <span class="hlt">widths</span> of annual <span class="hlt">rings</span> of two beech samples from the region of Central Balkan Range are used. Special attention is paid to the 22 yr oscillations in the <span class="hlt">growth</span> of tree mass and the relationship between the oscillation amplitude and the phase of solar cycles with sub-century and two-century duration. It is shown that the attenuation of 20-22 yr magnetic solar cycle during the hyper-centurial Dalton minimum (1795-1825/1830) is accompanied by strong drying and warming of the summers in Central Southern Bulgaria during this time. The onset of new Dalton-type hyper-centurial minimum in the beginning of the 21st century corresponds to an analogous climatic situation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4478S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4478S&link_type=ABSTRACT"><span id="translatedtitle">North Atlantic Oscillation records in Siberian tree <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sidorova, Olga; Saurer, Matthias; Siegwolf, Rolf</p> <p>2010-05-01</p> <p>Changes in the Eurasian subarctic like temperature increase, thawing of permafrost, changes in seasonality (shifting of the beginning of the <span class="hlt">growth</span> period), and changes in the amount of precipitations are linked to a positive phase of North Atlantic Oscillation (NAO) in recent decades. We report about the response of larch trees to climatic changes in the eastern Taimyr (Central Siberia) and northeastern Yakutia (Eastern Siberia) at high latitudes during the last century using tree <span class="hlt">ring</span> <span class="hlt">width</span>, latewood density and stable isotope wood and cellulose (δ13C, δ18O) chronologies. Not only the summer months were related to the carbon and oxygen isotope variations. The positive relationship, which was found between February temperature and δ18O of cellulose for northeastern Yakutia and the negative correlations between the temperature of February and δ13C of wood and cellulose for eastern Taimyr, could be explained by the influence of North Atlantic Oscillation. This work was supported by Swiss National Science Foundation SNF 200021_121838/1 and RFBR_sibir 09-05-98015.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15020216','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15020216"><span id="translatedtitle">Transverse instability at the recycler <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ng, K.Y.; /Fermilab</p> <p>2004-10-01</p> <p>Sporadic transverse instabilities have been observed at the Fermilab Recycler <span class="hlt">Ring</span> leading to increase in transverse emittances and beam loss. The driving source of these instabilities has been attributed to the resistive-wall impedance with space-charge playing an important role in suppressing Landau damping. <span class="hlt">Growth</span> rates of the instabilities are computed. Remaining problems are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA08163&hterms=shooting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dshooting','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA08163&hterms=shooting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dshooting"><span id="translatedtitle">The Enceladus <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2006-01-01</p> <p><p/> [figure removed for brevity, see original site] The Enceladus <span class="hlt">Ring</span> (labeled) <p/> This excellent view of the faint E <span class="hlt">ring</span> -- a <span class="hlt">ring</span> feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the <span class="hlt">ring</span>, among a field of stars in the background. <p/> The E <span class="hlt">ring</span> extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view. <p/> Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E <span class="hlt">ring</span>'s expanse. Helene skirts the outer parts of the E <span class="hlt">ring</span>, but here it is projected in front of a region deeper within the <span class="hlt">ring</span>. <p/> Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione. <p/> An interesting feature of note in this image is the double-banded appearance of the E-<span class="hlt">ring</span>, which is created because the <span class="hlt">ring</span> is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the <span class="hlt">ring</span> have nonzero inclinations (a similar affect is seen in Jupiter's gossamer <span class="hlt">ring</span>). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus. <p/> One possible explanation is that all the E <span class="hlt">ring</span> particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane. <p/> Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPlPh..82a9009M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPlPh..82a9009M"><span id="translatedtitle">The <span class="hlt">width</span> of the solitary wave in dusty plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malekolkalami, Behrooz; Alipanah, Amjad</p> <p>2016-01-01</p> <p>The Sagdeev potential method is employed to compute the <span class="hlt">width</span> of the ion-acoustic solitary wave propagated in a dusty plasma containing three components (dust-ion-electron). The results indicate that the <span class="hlt">width</span> is a continuous function over the allowable ranges of plasma parameters. The complexity of the resulting equations is an obstacle to the expression of the <span class="hlt">width</span> function in an explicit form in terms of the parameters. Thus, computer algebra is needed to plot the graph of the <span class="hlt">width</span> function versus the parameters, which helps us to understand the <span class="hlt">width</span> changes as the parameters change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1083810','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1083810"><span id="translatedtitle">Global synchronization of parallel processors using clock pulse <span class="hlt">width</span> modulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.</p> <p>2013-04-02</p> <p>A circuit generates a global clock signal with a pulse <span class="hlt">width</span> modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse <span class="hlt">width</span> modification on the clock signal. The pulse <span class="hlt">width</span> modification changes a pulse <span class="hlt">width</span> within a clock period in the clock signal. The clock splitter may distribute the pulse <span class="hlt">width</span> modified clock signal to a plurality of processors in the parallel computing system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002APS..DPPUP1034A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002APS..DPPUP1034A"><span id="translatedtitle">SOL <span class="hlt">Width</span> Scaling in the MAST Tokamak</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, Joon-Wook; Counsell, Glenn; Connor, Jack; Kirk, Andrew</p> <p>2002-11-01</p> <p>Target heat loads are determined in large part by the upstream SOL heat flux <span class="hlt">width</span>, Δ_h. Considerable effort has been made in the past to develop analytical and empirical scalings for Δh to allow reliable estimates to be made for the next-step device. The development of scalings for a large spherical tokamak (ST) such as MAST is particularly important both for development of the ST concept and for improving the robustness of scalings derived for conventional tokamaks. A first such scaling has been developed in MAST DND plasmas. The scaling was developed by flux-mapping data from the target Langmuir probe arrays to the mid-plane and fitting to key upstream parameters such as P_SOL, bar ne and q_95. In order to minimise the effects of co-linearity, dedicated campaigns were undertaken to explore the widest possible range of each parameter while keeping the remainder as fixed as possible. Initial results indicate a weak inverse dependence on P_SOL and approximately linear dependence on bar n_e. Scalings derived from consideration of theoretical edge transport models and integration with data from conventional devices is under way. The established scaling laws could be used for the extrapolations to the future machine such as Spherical Tokamak Power Plant (STPP). This work is jointly funded by Euratom and UK Department of Trade and Industry. J-W. Ahn would like to recognise the support of a grant from the British Foreign & Commonwealth Office.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.381a2078W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.381a2078W"><span id="translatedtitle">Absolute decay <span class="hlt">width</span> measurements in 16O</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wheldon, C.; Ashwood, N. I.; Barr, M.; Curtis, N.; Freer, M.; Kokalova, Tz; Malcolm, J. D.; Spencer, S. J.; Ziman, V. A.; Faestermann, Th; Krücken, R.; Wirth, H.-F.; Hertenberger, R.; Lutter, R.; Bergmaier, A.</p> <p>2012-09-01</p> <p>The reaction 126C(63Li, d)168O* at a 6Li bombarding energy of 42 MeV has been used to populate excited states in 16O. The deuteron ejectiles were measured using the high-resolution Munich Q3D spectrograph. A large-acceptance silicon-strip detector array was used to register the recoil and break-up products. This complete kinematic set-up has enabled absolute α-decay <span class="hlt">widths</span> to be measured with high-resolution in the 13.9 to 15.9 MeV excitation energy regime in 16O; many for the first time. This energy region spans the 14.4 MeV four-α breakup threshold. Monte-Carlo simulations of the detector geometry and break-up processes yield detection efficiencies for the two dominant decay modes of 40% and 37% for the α+12C(g.s.) and a+12C(2+1) break-up channels respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..356D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..356D"><span id="translatedtitle">Invariantly propagating dissolution fingers in finite-<span class="hlt">width</span> systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dutka, Filip; Szymczak, Piotr</p> <p>2016-04-01</p> <p>Dissolution fingers are formed in porous medium due to positive feedback between transport of reactant and chemical reactions [1-4]. We investigate two-dimensional semi-infinite systems, with constant <span class="hlt">width</span> W in one direction. In numerical simulations we solve the Darcy flow problem combined with advection-dispersion-reaction equation for the solute transport to track the evolving shapes of the fingers and concentration of reactant in the system. We find the stationary, invariantly propagating finger shapes for different <span class="hlt">widths</span> of the system, flow and reaction rates. Shape of the reaction front, turns out to be controlled by two dimensionless numbers - the (<span class="hlt">width</span>-based) Péclet number PeW = vW/Dφ0 and Damköhler number DaW = ksW/v, where k is the reaction rate, s - specific reactive surface area, v - characteristic flow rate, D - diffusion coefficient of the solute, and φ0 - initial porosity of the rock matrix. Depending on PeW and DaW stationary shapes can be divided into seperate classes, e.g. parabolic-like and needle-like structures, which can be inferred from theoretical predictions. In addition we determine velocity of propagating fingers in time and concentration of reagent in the system. Our simulations are compared with natural forms (solution pipes). P. Ortoleva, J. Chadam, E. Merino, and A. Sen, Geochemical self-organization II: the reactive-infiltration instability, Am. J. Sci, 287, 1008-1040 (1987). M. L. Hoefner, and H. S. Fogler. Pore evolution and channel formation during flow and reaction in porous media, AIChE Journal 34, 45-54 (1988). C. E. Cohen, D. Ding, M. Quintard, and B. Bazin, From pore scale to wellbore scale: impact of geometry on wormhole <span class="hlt">growth</span> in carbonate acidization, Chemical Engineering Science 63, 3088-3099 (2008). P. Szymczak and A. J. C. Ladd, Reactive-infiltration nstabilities in rocks. Part II: Dissolution of a porous matrix, J. Fluid Mech. 738, 591-630 (2014).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.P23B1635H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.P23B1635H"><span id="translatedtitle">Earth: A <span class="hlt">Ringed</span> Planet?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hancock, L. O.; Povenmire, H.</p> <p>2010-12-01</p> <p>Among the most beautiful findings of the Space Age have been the discoveries of planetary <span class="hlt">rings</span>. Not only Saturn but also Jupiter, Uranus and Neptune have <span class="hlt">rings</span>; Saturn’s <span class="hlt">ring</span> system has structures newly discovered; even Saturn's moon Rhea itself has a <span class="hlt">ring</span>. All these are apparently supplied by material from the planetary moons (Rhea's <span class="hlt">ring</span> by Rhea itself). The question naturally arises, why should the Earth not have a <span class="hlt">ring</span>, and on the other hand, if it does, why has it not been observed? No <span class="hlt">rings</span> have yet been observed in the inner solar system, but after all, <span class="hlt">rings</span> in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a <span class="hlt">ring</span> system of its own. An Earth <span class="hlt">ring</span> could account for some climate events. O’Keefe remarked that formation or thickening of a <span class="hlt">ring</span> system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth <span class="hlt">ring</span> has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth <span class="hlt">ring</span> system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the <span class="hlt">ring</span> fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth <span class="hlt">ring</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24480275','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24480275"><span id="translatedtitle">Equivalent <span class="hlt">width</span> evaluation methods for Doppler, Lorentz, and Voigt profiles.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Habib, Abdel Aziz M; Rammah, Yasser S</p> <p>2014-01-01</p> <p>An accurate technique has been developed to calculate the equivalent <span class="hlt">width</span> of absorption lines. The calculations have been carried out for the pure Doppler and pure Lorentz limiting forms of the equivalent <span class="hlt">width</span>. A novel expression for the equivalent <span class="hlt">width</span> for Lorentz profile is given from direct integration of the line profile. The more general case of a Voigt profile leads to an analytical formula that permits a rapid estimate of the equivalent <span class="hlt">width</span> for a wide range of maximum optical depths. The reliability of the approach is verified using a numerical application calculating the equivalent <span class="hlt">width</span> for nickel resonance lines at 232.0 and 352.3 nm from atomic absorption (AA) measurements. The dependence of equivalent <span class="hlt">width</span> on the number density of absorbing atoms is also provided. The results obtained for the equivalent <span class="hlt">width</span> for the Voigt profile were compared with the data in the available literature obtained by different approaches. PMID:24480275</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006002','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006002"><span id="translatedtitle">Seal <span class="hlt">ring</span> installation tool</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Haselmaier, L. Haynes (Inventor)</p> <p>2004-01-01</p> <p>A seal <span class="hlt">ring</span> tool that allows an installer to position a primary seal <span class="hlt">ring</span> between hub ends of pipe flanges that are being assembled together. The tool includes a pivoting handle member and extension arms attached to the pivoting handle member. The ends of the arms have side indentation type longitudinal grooves angled toward one another for holding the primary seal <span class="hlt">ring</span> in place between the hubs of respective pipes that are to be attached together. The arms of the tool can also have flat sides that can be used to abut against an optional second larger seal that is supported within a groove in one of the hub ends so that the second hub end can then be moved against the other side of the primary seal <span class="hlt">ring</span>. Once the seal <span class="hlt">ring</span> is positioned between the pipe hubs, the pipe hubs can be moved about the seal <span class="hlt">ring</span> due to the flat sides of the arms of the tool. The tool eliminates the chances of damaging and contaminating seal <span class="hlt">rings</span> being installed within pipe hubs that are being attached to one another.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880005104','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880005104"><span id="translatedtitle">Hot piston <span class="hlt">ring</span> tests</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Allen, David J.; Tomazic, William A.</p> <p>1987-01-01</p> <p>As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston <span class="hlt">ring</span> near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional <span class="hlt">rings</span> at the bottom of the piston, these hot <span class="hlt">rings</span> operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot <span class="hlt">rings</span> and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot <span class="hlt">rings</span> and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot <span class="hlt">rings</span>. Seal leakage measurements showed a significant reduction. Wear on both <span class="hlt">rings</span> and coating was low.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhRvB..79r4409S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhRvB..79r4409S"><span id="translatedtitle">Magnetic transitions in ultra-small nanoscopic magnetic <span class="hlt">rings</span>: Theory and experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Deepak K.; Krotkov, Robert; Tuominen, Mark T.</p> <p>2009-05-01</p> <p>In this paper, we report on experimental and theoretical investigations of magnetic transitions in cobalt <span class="hlt">rings</span> of size (diameter, <span class="hlt">width</span> and thickness) comparable to the exchange length of cobalt. Magnetization measurements and calculations were performed for two sets of magnetic <span class="hlt">ring</span> arrays: ultra-small magnetic <span class="hlt">rings</span> (outer diameter 13 nm, inner diameter 5 nm and thickness 5 nm) and small magnetic <span class="hlt">rings</span> (outer diameter 150 nm, <span class="hlt">width</span> 5 nm, and thickness 5 nm). Our calculations suggest that if the linear dimensions of a magnetic <span class="hlt">ring</span> are comparable to, or smaller than, the exchange length of the magnetic material, then only one magnetic state is important—the pure single-domain state. Vortex and onion-shape magnetic states do not arise. For a <span class="hlt">ring</span> of larger diameter, magnetization reversal at zero field occurs via a vortex state. Theoretical calculations are based on an energetic analysis of pure and slightly distorted single-domain and vortex magnetic states. The calculations have been verified by micromagnetic simulations for ultra-small and small <span class="hlt">ring</span> geometries. The hysteresis curves measured for small <span class="hlt">rings</span> are consistent with the calculations, but there is a discrepancy for ultra-small <span class="hlt">rings</span>. Micromagnetic simulations suggest that the discrepancies may be due to the variations in the shape and size of the ultra-small <span class="hlt">rings</span> in the measured sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015APS..DFDA33004W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015APS..DFDA33004W&link_type=ABSTRACT"><span id="translatedtitle">Coffee <span class="hlt">ring</span> effect resulted conductive nanowire patterns by evaporating colloidal suspension droplets without sintering process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xiaofeng; Seong, Baekhoon; Yudistira, Hadi Teguh; Byun, Doyoung</p> <p>2015-11-01</p> <p>Drying colloidal suspensions containing non-volatile solute will form a <span class="hlt">ring</span> like pattern, which is called ``coffee <span class="hlt">ring</span> effect.'' Here, we present the coffee <span class="hlt">ring</span> effect with silver nanowires dispersing into DI water, resulting in a highly dense-packed nanowire <span class="hlt">ring</span> patterns. The effect of nanowire length, concentration, droplet size, and substrate temperature were investigated. With shorter nanowires, a distinct <span class="hlt">ring</span> could be obtained. Meanwhile, the concentration of the colloidal suspension was found to affect the <span class="hlt">ring</span> <span class="hlt">width</span>. The droplet size and nanowire length played a significant role in affecting the occurrence of the coffee <span class="hlt">ring</span> effect. When smaller droplets (i.e., less than 150 μm) containing long nanowires (~ 20 μm), the coffee <span class="hlt">ring</span> effect was suppressed. While smaller droplets containing short nanowires (~ 1 μm), the coffee <span class="hlt">ring</span> effect was not affected. By increasing the temperature of the substrate, multi-<span class="hlt">ring</span> pattern was formed inside the original <span class="hlt">ring</span>. The resistivity of the semi-circle of the nanowire <span class="hlt">ring</span> was measured, and had a minimum value of 1.32 × 10-6 Ωm without any sintering process. These findings could be exploited to basic study of <span class="hlt">ring</span> stain effect as well as the practical use, such as evaporative lithography and ink-jet printing for conductive film and display. This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) (Grant number: 2014-023284).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JGR...104.8473P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JGR...104.8473P"><span id="translatedtitle">Downflow <span class="hlt">width</span> behavior of Martian and terrestrial lava flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peitersen, Matthew N.; Crown, David A.</p> <p>1999-04-01</p> <p>Examination of the downflow <span class="hlt">width</span> behavior of 59 terrestrial lava flows at Puu Oo (Hawaii) and Glass Mountain (California) and 86 Martian flows at Alba Patera, Tyrrhena Patera, Elysium, and Olympus Mons was completed using aerial photographs, topographic maps, previously published flow maps, and Viking Orbiter images. The examined lava flows exhibit diverse <span class="hlt">width</span> behavior, from which information about flow processes and conditions was assessed. For Puu Oo flows, no significant correlation was found between the average <span class="hlt">width</span> of a flow and flow length or average underlying slope. A significant, but weak relationship was found between average <span class="hlt">width</span> and average flow thickness. In analyses of the downflow <span class="hlt">width</span> behavior of individual flows, no consistent correlations were observed between <span class="hlt">width</span> and thickness or underlying slope. When <span class="hlt">width</span> was analyzed as a function of distance from the source for all flows, a variety of flow <span class="hlt">width</span> behavioral trends were recognized and quantitatively classified. The most common behavior observed on Earth and Mars involved variations of <span class="hlt">width</span> (sometimes significant) about a mean without a significant downflow narrowing or widening trend. The distributions of <span class="hlt">width</span> behavior trends for the Alba Patera and Puu Oo flows examined were similar, with this type of ``constant'' behavior dominating. In contrast, Tyrrhena Patera flows showed a tendency to widen with distance downflow, and silicic flows at Glass Mountain were more likely to narrow. Flows were also subdivided by distance from the vent, and the <span class="hlt">width</span> behavior of each division classified. Subdivision of flows resulted in significant changes in the classification of <span class="hlt">width</span> behavior. While <span class="hlt">width</span> behavior in the medial regions of flows was similar to that over entire flow lengths, proximal regions show more variability (possibly due to greater fluidity of lavas near the vent) and distal regions tend to uniformly narrow (possibly due to limited supply). In certain cases, classification and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850003648&hterms=Ants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DAnts','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850003648&hterms=Ants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DAnts"><span id="translatedtitle">Dynamics of the Uranian <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dermott, S. F.</p> <p>1984-01-01</p> <p>Some of the problems of the shepherding satellite model of Goldreich ant tremaine are discussed. The following topics are studied: (1) optical depths of the all the observed narrow <span class="hlt">rings</span>; (2) satellite and <span class="hlt">ring</span> separation timescales; (3) <span class="hlt">ring</span> edge sharpness; (4) shock formation in narrow <span class="hlt">rings</span>; (5) the existence of small satellites near the Uranian <span class="hlt">rings</span>; and (6) the apse and node alignments of the eccentric and inclined <span class="hlt">rings</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100021268','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100021268"><span id="translatedtitle">Theodolite <span class="hlt">Ring</span> Lights</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clark, David</p> <p>2006-01-01</p> <p>Theodolite <span class="hlt">ring</span> lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite <span class="hlt">ring</span> light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite <span class="hlt">ring</span> light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991AmSci..79...44A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991AmSci..79...44A"><span id="translatedtitle">Dynamics of planetary <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Araki, S.</p> <p>1991-02-01</p> <p>The modeling of the dynamics of particle collisions within planetary <span class="hlt">rings</span> is discussed. Particles in the <span class="hlt">rings</span> collide with one another because they have small random motions in addition to their orbital velocity. The orbital speed is roughly 10 km/s, while the random motions have an average speed of about a tenth of a millimeter per second. As a result, the particle collisions are very gentle. Numerical analysis and simulation of the <span class="hlt">ring</span> dynamics, performed with the aid of a supercomputer, is outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900012966','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900012966"><span id="translatedtitle">Alternative parallel <span class="hlt">ring</span> protocols</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mukkamala, R.; Foudriat, E. C.; Maly, Kurt J.; Kale, V.</p> <p>1990-01-01</p> <p>Communication protocols are know to influence the utilization and performance of communication network. The effect of two token <span class="hlt">ring</span> protocols on a gigabit network with multiple <span class="hlt">ring</span> structure is investigated. In the first protocol, a mode sends at most one message on receiving a token. In the second protocol, a mode sends all the waiting messages when a token is received. The behavior of these protocols is shown to be highly dependent on the number of <span class="hlt">rings</span> as well as the load in the network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.P13B1669E&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.P13B1669E&link_type=ABSTRACT"><span id="translatedtitle">A Post-Equinox View of Saturn's <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Esposito, L. W.</p> <p>2011-12-01</p> <p>Cassini observed the Saturn Equinox of 2009, providing a unique geometry and unexpected findings: 1. The oblique lighting exposed vertical <span class="hlt">ring</span> structure and embedded objects; 2. Saturn's <span class="hlt">Rings</span> were the coldest ever; 3. Cassini images inspired new occultation and spectral analysis of <span class="hlt">ring</span> structures like those in the images. Steady progress and new discoveries continue after the equinox. We can now recognize some aspects of a 'Post-Equinox View': 1. Cassini equinox observations show Saturn's <span class="hlt">rings</span> as a complex geophysical system, incompletely modeled as a single-phase fluid; 2. Self-gravity causes wakes, viscosity, overstabilty and local aggregate <span class="hlt">growth</span>; 3. Larger fragments provide the seeds for <span class="hlt">growth</span> of new aggregates; 4. The F <span class="hlt">ring</span> may be the easiest place to observe aggregation/disaggregation. These findings have significant implications for our understanding of <span class="hlt">ring</span> dynamics, origin and history: 1. Self-gravity plays a large role; 2. Accretion continues today in <span class="hlt">rings</span> A, B, C and F, that can renew the <span class="hlt">ring</span> material; 3. Resonance forcing and Kepler shear provide the energy for a multitude of dynamics; 4. Structure forms throughout the <span class="hlt">rings</span>, at scales from meters to kilometers Questions that we now can address following the equinox: 1. Is the red color of the <span class="hlt">rings</span> caused by Carbon or nano-hematite? 2. Are the <span class="hlt">rings</span> young or old? 3. Can we estimate the B <span class="hlt">ring</span> mass from haloes, or from precession of CD ringlets? 4. Or must we wait until the <span class="hlt">ring</span> gravity is evident during Cassini's final orbits? 5. What is the relative contribution of deterministic and stochastic forcing in creating the observed structure? 6. Do moons continue to form today? I will review these new findings, questions and possible paths to answers. Those who attend my poster will be asked for their own views.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22126576','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22126576"><span id="translatedtitle">STAR FORMATION IN NUCLEAR <span class="hlt">RINGS</span> OF BARRED GALAXIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Seo, Woo-Young; Kim, Woong-Tae E-mail: wkim@astro.snu.ac.kr</p> <p>2013-06-01</p> <p>Nuclear <span class="hlt">rings</span> in barred galaxies are sites of active star formation. We use hydrodynamic simulations to study the temporal and spatial behavior of star formation occurring in nuclear <span class="hlt">rings</span> of barred galaxies where radial gas inflows are triggered solely by a bar potential. The star formation recipes include a density threshold, an efficiency, conversion of gas to star particles, and delayed momentum feedback via supernova explosions. We find that the star formation rate (SFR) in a nuclear <span class="hlt">ring</span> is roughly equal to the mass inflow rate to the <span class="hlt">ring</span>, while it has a weak dependence on the total gas mass in the <span class="hlt">ring</span>. The SFR typically exhibits a strong primary burst followed by weak secondary bursts before declining to very small values. The primary burst is associated with the rapid gas infall to the <span class="hlt">ring</span> due to the bar <span class="hlt">growth</span>, while the secondary bursts are caused by re-infall of the ejected gas from the primary burst. While star formation in observed <span class="hlt">rings</span> persists episodically over a few Gyr, the duration of active star formation in our models lasts for only about half of the bar <span class="hlt">growth</span> time, suggesting that the bar potential alone is unlikely to be responsible for gas supply to the <span class="hlt">rings</span>. When the SFR is low, most star formation occurs at the contact points between the <span class="hlt">ring</span> and the dust lanes, leading to an azimuthal age gradient of young star clusters. When the SFR is large, on the other hand, star formation is randomly distributed over the whole circumference of the <span class="hlt">ring</span>, resulting in no apparent azimuthal age gradient. Since the <span class="hlt">ring</span> shrinks in size with time, star clusters also exhibit a radial age gradient, with younger clusters found closer to the <span class="hlt">ring</span>. The cluster mass function is well described by a power law, with a slope depending on the SFR. Giant gas clouds in the <span class="hlt">rings</span> have supersonic internal velocity dispersions and are gravitationally bound.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRD..118.9000D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRD..118.9000D"><span id="translatedtitle">Volcanic cooling signal in tree <span class="hlt">ring</span> temperature records for the past millennium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Arrigo, Rosanne; Wilson, Rob; Anchukaitis, Kevin J.</p> <p>2013-08-01</p> <p><span class="hlt">rings</span> are an important proxy for understanding the timing and environmental consequences of volcanic eruptions as they are precisely dated at annual resolution and, particularly in tree line regions of the world, sensitive to cold extremes that can result from climatically significant volcanic episodes. Volcanic signals have been detected in <span class="hlt">ring</span> <span class="hlt">widths</span> and by the presence of frost-damaged <span class="hlt">rings</span>, yet are often most clearly and quantitatively represented within maximum latewood density series. <span class="hlt">Ring</span> <span class="hlt">width</span> and density reconstructions provide quantitative information for inferring the variability and sensitivity of the Earth's climate system on local to hemispheric scales. After a century of dendrochronological science, there is no evidence, as recently theorized, that volcanic or other adverse events cause such severely cold conditions near latitudinal tree line that <span class="hlt">rings</span> might be missing in all trees at a given site in a volcanic year ("stand-wide" missing <span class="hlt">rings</span>), resulting in misdating of the chronology. Rather, there is a clear indication of precise dating and development of <span class="hlt">rings</span> in at least some trees at any given site, even under adverse cold conditions, based on both actual tree <span class="hlt">ring</span> observations and modeling analyses. The muted evidence for volcanic cooling in large-scale temperature reconstructions based at least partly on <span class="hlt">ring</span> <span class="hlt">widths</span> reflects several factors that are completely unrelated to any misdating. These include biological persistence of such records, as well as varying spatial patterns of response of the climate system to volcanic events, such that regional cooling, particularly for <span class="hlt">ring</span> <span class="hlt">widths</span> rather than density, can be masked in the large-scale reconstruction average.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.11801032S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.11801032S"><span id="translatedtitle">Storage <span class="hlt">Ring</span> EDM Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semertzidis, Yannis K.</p> <p>2016-04-01</p> <p>Dedicated storage <span class="hlt">ring</span> electric dipole moment (EDM) methods show great promise advancing the sensitivity level by a couple orders of magnitude over currently planned hadronic EDM experiments. We describe the present status and recent updates of the field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4721803T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4721803T"><span id="translatedtitle">Heating Saturn's Clumpy <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turner, Neal J.; Morishima, Ryuji; Spilker, Linda J.</p> <p>2015-11-01</p> <p>We model Cassini CIRS data using a Monte Carlo radiative transfer -- thermal balance technique first developed for protostellar disks, with the goals of:1. Exploring whether the A- and B-<span class="hlt">ring</span> temperatures' variation with viewing angle is consistent with the wake structures suggested by the observed azimuthal asymmetry in optical depth, by analytic arguments, and by numerical N-body modeling.2. Better constraining the shape, size, spacing and optical depths of substructure in the A-<span class="hlt">ring</span>, using the unexpectedly high temperatures observed at equinox. If the wake features have high enough contrast, Saturn-shine may penetrate the gaps between the wakes and heat thering particles both top and bottom.3. Determining how much of the heating of the A- and B-<span class="hlt">rings</span>' unlit sides is due to radiative transport and how much is due to particle motions, especially vertical motions. This will help in constraining the <span class="hlt">rings</span>' surface densities and masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25831574','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25831574"><span id="translatedtitle">Radiographic reference limits for cardiac <span class="hlt">width</span> of budgerigars (Melopsittacus undulatus).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Velayati, Mozhgan; Mirshahi, Ali; Razmyar, Jamshid; Azizzadeh, Mohammad</p> <p>2015-03-01</p> <p>Primary and secondary cardiovascular diseases are not uncommon in birds. Although radiologic standards for heart <span class="hlt">width</span> have been developed for mammals, they are still not available for many avian species. The purpose of this study was to establish normal reference values for cardiac size in budgerigar (Melopsittacus undulatus), one of the most popular pet bird species all over the world. After clinical and radiographic (lateral and ventrodorsal views) evaluations, 27 adult, clinically healthy budgerigars (10 females and 17 males) were included in this study. High-quality ventrodorsal and lateral radiographic projections were obtained. The cardiac and thoracic <span class="hlt">width</span>, distance between third and fourth ribs, synsacrum <span class="hlt">width</span>, coracoid <span class="hlt">width</span>, and the distance between clavicle bones were measured on ventrodorsal radiographs. The ratio between cardiac <span class="hlt">width</span> and other mentioned indices was calculated. Correlation of each anatomical index with the cardiac <span class="hlt">width</span> was evaluated by linear regression model. Sex and weight were included in all models. Mean + SD of cardiac <span class="hlt">width</span> was 10.8 +/- 0.6 mm, with lower and upper limits of 9.5 and 12.0 mm. The results showed a significant correlation between the cardiac <span class="hlt">width</span> and the thoracic <span class="hlt">width</span> (R2 = 0.28; P = 0.005). There were no significant associations between weight, sex, and the heart <span class="hlt">width</span>. The values and ratios obtained in this study can be used as a reference of normal cardiac size of budgerigar in radiology for detection of cardiomegaly in this bird. PMID:25831574</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70030069','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70030069"><span id="translatedtitle">Saturn's dynamic D <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.</p> <p>2007-01-01</p> <p>The Cassini spacecraft has provided the first clear images of the D <span class="hlt">ring</span> since the Voyager missions. These observations show that the structure of the D <span class="hlt">ring</span> has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D <span class="hlt">ring</span>. Cassini also finds that the locations of other narrow features in the D <span class="hlt">ring</span> and the structure of the diffuse material in the D <span class="hlt">ring</span> differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D <span class="hlt">ring</span> that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C <span class="hlt">ring</span> that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D <span class="hlt">ring</span> contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D <span class="hlt">ring</span> that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D <span class="hlt">ring</span> produced by differential nodal regression of an initially inclined <span class="hlt">ring</span>. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02242&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02242&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Mosaic of Saturn's <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This detailed mosaic of the underside of the Cassini Division was obtained by Voyager 1 with a resolution of about 10 kilometers. The classical Cassini Division appears here to the right of center as five bright <span class="hlt">rings</span> with substantial blacks gap on either side. The inner edge of the A <span class="hlt">Ring</span>, to the left of center, is the brightest part of this image. The fine-scale wave structure in this region has been interpreted as being the result of gravitational density waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02289&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02289&hterms=saturns+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsaturns%2Brings"><span id="translatedtitle">Saturn's B <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This narrow-angle camera image of Saturn's B <span class="hlt">Ring</span> and Cassini Division was taken through the Clear filter from a distance of 12.6 million km on 3 November 1980. The Cassini Division separating the A and B <span class="hlt">Rings</span> is clearly not an empty region. The Division shows several substantial well-defined ringlets. JPL managed the Voyager Project for NASA's Office of Space Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMPP51A2262T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMPP51A2262T&link_type=ABSTRACT"><span id="translatedtitle">Tree <span class="hlt">ring</span> anatomical variability as an indicator for large-magnitude spring flooding in the Lower Mississippi Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Therrell, M. D.; Meko, M. D.; Bialecki, M.; Harley, G. L.</p> <p>2015-12-01</p> <p>Predicting the magnitude and frequency of floods relies on instrumental measurements of flood stage and discharge, however instrumental observations prior to the late-nineteenth century are rare. Using paleoproxies such as tree <span class="hlt">rings</span> to study floods that occurred before the instrumental record, can help provide context for the modern flood record especially the variability of flood recurrence patterns. Riparian trees growing on flooded sites often record flood events as inter- and intra-annual variability in size, shape and arrangement of vessels in the annual xylem <span class="hlt">growth</span> increment. In this study, we used anomalous anatomical features as well as a modified measure of earlywood (EW) vessel <span class="hlt">width</span> of oak (Quercus sp.) annual tree <span class="hlt">rings</span> to identify large-magnitude spring-season flood events at three locations in the Lower Mississippi River (LMR) basin for the past ~300 years. We compared the flood-<span class="hlt">ring</span> anomaly and EW chronologies with daily river stage height data at several locations and these comparisons indicate that our new flood <span class="hlt">ring</span> records can individually and jointly explain significant amounts of the variance in both stage height and number of days in flood during spring flood events. Our analyses indicate that our chronologies are recording nearly all large observed LMR floods in the 20th century, and provide a new record of similar events in the 18th and 19th centuries. These results suggest that tree-<span class="hlt">rings</span> can be effectively used to develop and improve pre-instrumental flood records throughout the LMW region and potentially other similar systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23564688','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23564688"><span id="translatedtitle">Rapid warming accelerates tree <span class="hlt">growth</span> decline in semi-arid forests of Inner Asia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Hongyan; Park Williams, A; Allen, Craig D; Guo, Dali; Wu, Xiuchen; Anenkhonov, Oleg A; Liang, Eryuan; Sandanov, Denis V; Yin, Yi; Qi, Zhaohuan; Badmaeva, Natalya K</p> <p>2013-08-01</p> <p>Forests around the world are subject to risk of high rates of tree <span class="hlt">growth</span> decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree <span class="hlt">growth</span> in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree <span class="hlt">growth</span> declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining <span class="hlt">growth</span> at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-<span class="hlt">ring</span> <span class="hlt">widths</span>. These <span class="hlt">ring-width</span> records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests. PMID:23564688</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JAP....97f3910M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JAP....97f3910M"><span id="translatedtitle">Magnetization reversal in individual micrometer-sized polycrystalline Permalloy <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, T. A.; Hayward, T. J.; Tse, D. H. Y.; Bland, J. A. C.; Castaño, F. J.; Ross, C. A.</p> <p>2005-03-01</p> <p>The magnetization reversal of individual 2 μm and 5 μm diameter polycrystalline Permalloy <span class="hlt">rings</span>, with respective <span class="hlt">widths</span> 0.75 μm and 1 μm, thickness 45 nm, has been investigated by focused magneto-optic Kerr effect (MOKE) magnetometry. Micromagnetic simulation of the reversal in the 2 μm diameter <span class="hlt">ring</span> reveals that the onion-to-vortex state switching occurs by nucleation and subsequent annihilation of vortex walls that span the <span class="hlt">width</span> of the <span class="hlt">ring</span>, and that the vortex-to-reverse-onion state switching occurs by expansion of a reverse domain. The hysteresis loop shows good agreement with the experimental MOKE loop. Measurements of the switching through one-half of a 5 μm diameter <span class="hlt">ring</span> enable the determination of the circulation of the vortex states accessed during one applied field cycle. The <span class="hlt">rings</span> switch via one vortex state (either clockwise or anticlockwise) on both downward and upward applied field sweeps. The number of applied field cycles spent switching via one vortex state before changing to switch via the opposite vortex state is random, likely to be due to the history of the spin configuration and thermal fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24352845','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24352845"><span id="translatedtitle">Temperature and rainfall strongly drive temporal <span class="hlt">growth</span> variation in Asian tropical forest trees.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vlam, Mart; Baker, Patrick J; Bunyavejchewin, Sarayudh; Zuidema, Pieter A</p> <p>2014-04-01</p> <p>Climate change effects on <span class="hlt">growth</span> rates of tropical trees may lead to alterations in carbon cycling of carbon-rich tropical forests. However, climate sensitivity of broad-leaved lowland tropical trees is poorly understood. Dendrochronology (tree-<span class="hlt">ring</span> analysis) provides a powerful tool to study the relationship between tropical tree <span class="hlt">growth</span> and annual climate variability. We aimed to establish climate-<span class="hlt">growth</span> relationships for five annual-<span class="hlt">ring</span> forming tree species, using <span class="hlt">ring-width</span> data from 459 canopy and understory trees from a seasonal tropical forest in western Thailand. Based on 183/459 trees, chronologies with total lengths between 29 and 62 years were produced for four out of five species. Bootstrapped correlation analysis revealed that climate-<span class="hlt">growth</span> responses were similar among these four species. <span class="hlt">Growth</span> was significantly negatively correlated with current-year maximum and minimum temperatures, and positively correlated with dry-season precipitation levels. Negative correlations between <span class="hlt">growth</span> and temperature may be attributed to a positive relationship between temperature and autotrophic respiration rates. The positive relationship between <span class="hlt">growth</span> and dry-season precipitation levels likely reflects the strong water demand during leaf flush. Mixed-effect models yielded results that were consistent across species: a negative effect of current wet-season maximum temperatures on <span class="hlt">growth</span>, but also additive positive effects of, for example, prior dry-season maximum temperatures. Our analyses showed that annual <span class="hlt">growth</span> variability in tropical trees is determined by a combination of both temperature and precipitation variability. With rising temperature, the predominantly negative relationship between temperature and <span class="hlt">growth</span> may imply decreasing <span class="hlt">growth</span> rates of tropical trees as a result of global warming. PMID:24352845</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...821...18P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...821...18P&link_type=ABSTRACT"><span id="translatedtitle">On the Mass and Origin of Chariklo’s <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, Margaret; Wu, Yanqin</p> <p>2016-04-01</p> <p>Observations in 2013 and 2014 of the Centaur 10199 Chariklo and its <span class="hlt">ring</span> system consistently indicated that the radial <span class="hlt">width</span> of the inner, more massive <span class="hlt">ring</span> varies with longitude. That strongly suggests that this <span class="hlt">ring</span> has a finite eccentricity despite the fast differential precession that Chariklo’s large quadrupole moment should induce. If the inferred apse alignment is maintained by the ring’s self-gravity, as it is for the Uranian <span class="hlt">rings</span>, we estimate a <span class="hlt">ring</span> mass of a few times 1016 g and a typical particle size of a few meters. These values imply a collisional spreading time of ∼105 years, which is somewhat shorter than the typical Centaur dynamical lifetime of a few million years and much shorter than the age of the solar system. In light of this time constraint, we evaluate previously suggested <span class="hlt">ring</span> formation pathways including collisional ejection and satellite disruption. We also investigate in detail a contrasting formation mechanism, the lofting of dust particles off Chariklo’s surface into orbit via outflows of sublimating CO and/or N2 triggered after Chariklo was scattered inward by giant planets. This alternate scenario predicts that <span class="hlt">rings</span> should be common among 100 km class Centaurs but rare among Kuiper Belt objects and smaller Centaurs. It also predicts that Centaurs should show seasonal variations in cometary activity with activity maxima occurring shortly after equinox.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013FrES....7..429L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013FrES....7..429L"><span id="translatedtitle">Dendrochronology-based stand <span class="hlt">growth</span> estimation of Larix olgensis forest in relation with climate on the eastern slope of Changbai Mountain, NE China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Bo; Xu, Qianqian; Liu, Wenhui; Zhang, Guochun; Xu, Qiongyao; Liu, Qijing</p> <p>2013-12-01</p> <p>The eastern slope of Changbai Mountain is characterized by pure larch forest ( Larix olgensis) with little human disturbance. Response of tree <span class="hlt">growth</span> to climate in this area remains unknown. Meanwhile, little is known about how climate variations affect the biomass increase which could be recognized as a three-dimensional tree <span class="hlt">growth</span> index. The objective of this study is to investigate the climate effects on the radial and biomass <span class="hlt">growth</span> of larch on eastern slope of Changbai Mountain. Tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies and mean annual biomass increment were established using tree-<span class="hlt">ring</span> data. We used correlation analysis and multiple regression analysis to explore the relationship between larch <span class="hlt">growth</span> and climatic factors from 1957 to 2009. Results show that tree-<span class="hlt">ring</span> <span class="hlt">growth</span> and mean annual biomass increment were primarily and significantly affected by previous year climatic variables with slight difference among months. Temperatures were more consistently and strongly correlated to the chronologies and mean annual biomass increment than was precipitation. Temperature is the main factor limiting larch <span class="hlt">growth</span> on Changbai Mountain and the ongoing climate warming may accelerate the <span class="hlt">growth</span> of the species. The current stand biomass of the area was 240.72 Mg·ha-1 and the annual stand biomass increment in 2009 was 2.91 Mg·ha-1. In conclusion, the old-<span class="hlt">growth</span> forest in the study area is still accumulating carbon efficiently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7118124','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7118124"><span id="translatedtitle">Light <span class="hlt">rings</span> in subarctic conifers as a dendrochronological tool</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Filion, L.; Payette, S.; Gauthier, L.; Boutin, Y.</p> <p>1986-01-01</p> <p>Light <span class="hlt">rings</span> are characterized by one or a very few latewood-cell layers, an indication of shortened growing seasons, and are particularly frequent in black spruce (Picea mariana (Mill.) BSP) at the treeline in Quebec. The construction of a light-<span class="hlt">ring</span> chronology spanning the period AD 1398-1982 showed that the highest frequency (>25%) of light <span class="hlt">rings</span> among 160 trees and krummholz occurred in 1593, 1620, 1634, 1784, 1816, 1817, 1853, 1969, and 1972. These diagnostic <span class="hlt">rings</span> may be a useful cross-dating tool for dendroecologists working with living and dead krummholz with a low-<span class="hlt">growth</span> variability. About two-thirds of the 65 light-<span class="hlt">ring</span> years coincide with years (or triads) of major volcanic eruptions. The climatic conditions (low temperature) occurring at the end of the growing season, in part induced by the climatic effect of volcanism, seem to initiate light <span class="hlt">rings</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Icar..226.1038D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Icar..226.1038D"><span id="translatedtitle">Near-infrared spectra of the uranian <span class="hlt">ring</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Kleer, Katherine; de Pater, Imke; Ádámkovics, Máté; Hammel, Heidi</p> <p>2013-09-01</p> <p>We present the first high-resolution near-infrared (1.18-2.38 μm) spectrum of the <span class="hlt">rings</span> of Uranus, as observed with adaptive optics on the W.M. Keck II telescope in August 2010. We derive <span class="hlt">ring</span> equivalent <span class="hlt">widths</span>, as well as <span class="hlt">ring</span> and particle reflectivities for the ɛ <span class="hlt">ring</span> and ringlet groups based on H- and K-band data. We find the <span class="hlt">rings</span> to be gray, indicating that they are dominated by large particles rather than dust, and we find no evidence for water ice. We present a reflectivity spectrum for the ɛ <span class="hlt">ring</span> alone, which we also find to be consistent with a flat spectrum. We derive H-band <span class="hlt">ring</span> particle reflectivities of 0.022 ± 0.010, 0.051 ± 0.009 0.042 ± 0.012, and 0.043 ± 0.001 and K-band <span class="hlt">ring</span> particle reflectivities of 0.016 ± 0.010, 0.034 ± 0.012, 0.047 ± 0.008 and 0.041 ± 0.002 for the 456, αβ, ηγδ, and ɛ <span class="hlt">ring</span> groups. Previous observations have found <span class="hlt">ring</span> particle reflectivities in the 0.033-0.044 range (de Pater, I., Gibbard, S., Macintosh, B.A., Roe, H.G. [2002]. Icarus 160, 359-374; Gibbard, S.G., de Pater, I., Hammel, H.B. [2005]. Icarus 174, 253-262), and are generally consistent with our results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC..992..484F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC..992..484F"><span id="translatedtitle">All fiber laser using a <span class="hlt">ring</span> cavity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flores, Alberto Varguez; Pérez, Georgina Beltrán; Aguirre, Severino Muñoz; Mixcóatl, Juan Castillo</p> <p>2008-04-01</p> <p>Mode-locked laser have a number of potential applications, depending on the wavelength and pulse <span class="hlt">width</span>. They could be used as sources in communications systems for time division multiplexing (TDM) or wavelength-division-multiplexing (WDM) as spectroscopic tools in the laboratory for time-resolved studies of fast nonlinear phenomena in semiconductors, or as seeds for solid-state amplifers such as Nd:Glass, color center alexandrite, or Ti:Sapphire. Short pulses also have potential use in electro-optic sampling systems, as a source for pulsed sensors, or as tunable seed pulses for lasers in medical applications. Applications such as optical coherent tomography could take advantage of the broad bandwidth of a mode-locked fiber laser rather that the temporal ultra-short pulse <span class="hlt">width</span>. This work shows the characterization of active mode-locking all-fiber laser by using an acousto-optic frequency shifter to the <span class="hlt">ring</span> cavity, an erbium doped fiber (EDF) and polarization controllers (PC). The results shows a highly stable mode-locked, low noise of pulse generation with repetition rate of 10 MHz and <span class="hlt">width</span> of 1.6 ns</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22368328','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22368328"><span id="translatedtitle">Biologic <span class="hlt">width</span> and its importance in periodontal and restorative dentistry.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nugala, Babitha; Kumar, Bb Santosh; Sahitya, S; Krishna, P Mohana</p> <p>2012-01-01</p> <p>An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic <span class="hlt">width</span>, its maintenance and applications of crown lengthening in cases of biologic <span class="hlt">width</span> violation. Relevant publications regarding biologic <span class="hlt">width</span>, its violation and management were identified up to August 2011 using manual and electronic database search in Medline, Embase, Directory of Open Access Journals and Google Scholar. This review discusses the concept of biologic <span class="hlt">width</span> around tooth and its relationship to periodontal health and restorative dentistry. PMID:22368328</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26489222','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26489222"><span id="translatedtitle">What's up with witch <span class="hlt">rings</span>?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heard, Priscilla; Phillips, David</p> <p>2015-01-01</p> <p>'Witch <span class="hlt">rings</span>' are well-known novelty <span class="hlt">rings</span> that show a size-change illusion when rotated. We have replicated the illusion of expansion of the reflections in the <span class="hlt">rings</span> in a variety of contexts with animations, though not as yet so successfully imitated the sense that the whole <span class="hlt">ring</span> expands and contracts. PMID:26489222</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012DPS....4441401D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012DPS....4441401D"><span id="translatedtitle">Keck and VLT AO Observations and Models of the Uranian <span class="hlt">Rings</span> During the 2007 <span class="hlt">Ring</span> Plane Crossings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Pater, Imke; Dunn, D. E.; Stam, D.; Showalter, M.; Min, M.; Hammel, H.; Matthews, K.; Gibbard, S.; van Dam, M.; Hartung, M.</p> <p>2012-10-01</p> <p>We observed the uranian <span class="hlt">rings</span> at and near the <span class="hlt">ring</span> plane crossing (RPX) of 16 August 2007 using the Keck and VLT telescopes, both equipped with near-infrared cameras coupled to adaptive optics systems. The <span class="hlt">rings</span> are partially obscuring each other when they are close edge-on; we therefore developed a model to analyze the observations. The model was tested by Dunn, de Pater and Stam (2010) against observations of the uranian <span class="hlt">rings</span> that were taken in July 2004. In this poster we present results based on a comparison of the RPX Keck and VLT observations with models. Main conclusions: 1) The zeta <span class="hlt">ring</span> appears to be vertically extended (full <span class="hlt">width</span> 860 km); 2) the zeta <span class="hlt">ring</span> is centrally condensed; 3) the extension of the eta <span class="hlt">ring</span> is optically thin, but contains macroscopic material; 4) there is a broad dust sheet throughout the system that contains very small dust grains (g=0.85 rather than 0.7). This work has been funded through NASA’s Planetary Astronomy Program and the National Science Foundation Science and Technology Center for Adaptive Optics.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22720600','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22720600"><span id="translatedtitle">[Responses of Picea likiangensis radial <span class="hlt">growth</span> to climate change in the Small Zhongdian area of Yunnan Province, Southwest China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Zhi-Jiang; Tan, Liu-Yi; Kang, Dong-Wei; Liu, Qi-Jing; Li, Jun-Qing</p> <p>2012-03-01</p> <p>Picea likiangensis (Franch. ) Pritz. primary forest is one of the dominant forest types in the Small Zhongdian area in Shangri-La County of Yunnan Province. In this paper, the responses of P. likiangensis tree-<span class="hlt">ring</span> <span class="hlt">width</span> to climate change were analyzed by dendrochronological methods, and the dendrochronology was built by using relatively conservative detrending negative exponential curves or linear regression. Correlation analysis and response function analysis were applied to explore the relationships between the residual chronology series (RES) and climatic factors at different time scales, and pointer year analysis was used to explain the reasons of producing narrow and wide <span class="hlt">rings</span>. In the study area, the radial <span class="hlt">growth</span> of P. likiangensis and the increasing air temperature from 1990 to 2008 had definite 'abruption'. The temperature and precipitation in previous year <span class="hlt">growth</span> season were the main factors limiting the present year radial <span class="hlt">growth</span>, and especially, the temperature in previous July played a negative feedback role in the radial <span class="hlt">growth</span>, while the sufficient precipitation in previous July promoted the radial <span class="hlt">growth</span>. The differences in the temperature variation and precipitation variation in previous year were the main reasons for the formation of narrow and wide <span class="hlt">rings</span>. P. likiangensis radial <span class="hlt">growth</span> was not sensitive to the variation of PDSI. PMID:22720600</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT........12M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT........12M"><span id="translatedtitle">Morphology, star formation, and kinematics of nuclear <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mazzuca, Lisa M.</p> <p></p> <p>This thesis presents a detailed optical study with the goal of better understanding the elusive physical nature of nuclear <span class="hlt">rings</span>. We first image the central kilo-parsec region of a large sample of spiral galaxies known for intense star formation via the Hal6563 line and the optical broad bands B and I . The distribution of massive young stars in the nuclear and circumnuclear environments verifies that nuclear <span class="hlt">rings</span> occur primarily in spiral types Sa- Sbc. Late-type galaxies have a patchy and more diffuse circumnuclear appearance in Ha. We identify three previously unknown nuclear <span class="hlt">rings</span>, and confirm that nuclear <span class="hlt">rings</span> are preferentially found in barred galaxies. From the parent sample, we identify 22 nuclear <span class="hlt">rings</span> and analyze the H II regions that comprise them. Comparing the Ha equivalent <span class="hlt">widths</span> of these regions with population synthesis models, we derive the ages throughout each nuclear <span class="hlt">ring</span>, and find that the stellar content within the <span class="hlt">rings</span> is consistently very young, with ages ranging from 1 Myr to 10 Myrs. Approximately half of the <span class="hlt">rings</span> contain azimuthal age gradients that encompass at least 25% of the <span class="hlt">ring</span>, although there is no apparent relationship between the presence or absence of age gradients and the morphology of the <span class="hlt">rings</span> or their host galaxies. Two-thirds of the galaxies containing a nuclear <span class="hlt">ring</span> and a bar show a link between the youngest H II region(s) and the location along the <span class="hlt">ring</span> where the bar dust lanes merge. We show that regions of enhanced star formation, as seen in nuclear <span class="hlt">rings</span>, correspond to regions with (1) the strongest Ha emission, (2) high luminosities of order 10 40 erg s -1 - 10 42 erg s -1 , (3) low residual velocities of order 10 km s -1 , and (4) low velocity dispersions ranging from 20 km s -1 - 50 km s -1 . Thus, within the <span class="hlt">rings</span>, the relatively cool and calm gas allows star formation to trigger. The lack of strong non-circular motions in the <span class="hlt">rings</span>, coupled with a direct relationship between the position angles and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhTea..54..112J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhTea..54..112J"><span id="translatedtitle">DC-Powered Jumping <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeffery, Rondo N.; Amiri, Farhang</p> <p>2016-02-01</p> <p>The classroom jumping <span class="hlt">ring</span> demonstration is nearly always performed using alternating current (AC), in which the <span class="hlt">ring</span> jumps or flies off the extended iron core when the switch is closed. The <span class="hlt">ring</span> jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant differences from the AC case. In particular, the <span class="hlt">ring</span> does not fly off the core but rises a short distance and then falls back. If the <span class="hlt">ring</span> jumps high enough, the rising and the falling motion of the <span class="hlt">ring</span> does not follow simple vertical motion of a projectile. This indicates that there are additional forces on the <span class="hlt">ring</span> in each part of its motion. Four possible stages of the motion of the <span class="hlt">ring</span> with DC are identified, which result from the <span class="hlt">ring</span> current changing directions during the jump in response to a changing magnetic flux through the moving <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EOSTr..92S.160T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EOSTr..92S.160T"><span id="translatedtitle">Tree <span class="hlt">ring</span> record chronicles major Mesoamerican droughts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tretkoff, Ernie</p> <p>2011-05-01</p> <p>A new tree <span class="hlt">ring</span> record chronicles major Mesoamerican droughts in the past millennium that may have contributed to the decline of some pre-Hispanic civilizations. Although there is other evidence of droughts during the past millennium, the paleoclimate record had gaps. Stahle et al. used core samples from Montezuma bald cypress trees found in Barranca de Amealco, Querétaro, Mexico, to develop a 1238-year tree <span class="hlt">ring</span> chronology. They reconstructed the soil moisture record from the tree <span class="hlt">ring</span> <span class="hlt">growth</span> patterns. The new record provides the first dated, annually resolved climate record for Mexico and Central America spanning this time period.(Geophysical Research Letters, doi:10.1029/2010GL046472, 2011)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010DPS....42.5006B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010DPS....42.5006B"><span id="translatedtitle">Mapping <span class="hlt">Ring</span> Particle Cooling across Saturn's <span class="hlt">Rings</span> with Cassini CIRS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.</p> <p>2010-10-01</p> <p>Previous studies have shown that the <span class="hlt">rings</span>' thermal inertia, a measure of their response to changes in the thermal environment, varies from <span class="hlt">ring</span> to <span class="hlt">ring</span>. Thermal inertia can provide insight into the physical structure of Saturn's <span class="hlt">ring</span> particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of <span class="hlt">ring</span> particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's <span class="hlt">rings</span> since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's <span class="hlt">rings</span> peaks in this wavelength range. FP1 spectra can be used to infer <span class="hlt">ring</span> temperatures. By tracking how <span class="hlt">ring</span> temperatures vary, we can determine the thermal inertia of the <span class="hlt">rings</span>. In this work we focus on CIRS observations of the shadowed portion of Saturn's <span class="hlt">rings</span>. The thermal budget of the <span class="hlt">rings</span> is dominated by the solar radiation absorbed by its constituent particles. When <span class="hlt">ring</span> particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, <span class="hlt">ring</span> particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the <span class="hlt">rings</span>. We will show that the <span class="hlt">rings</span>' cooling curves and thus their thermal inertia vary not only from <span class="hlt">ring</span> to <span class="hlt">ring</span>, but by location within the individual <span class="hlt">rings</span>. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPSC....9..140C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPSC....9..140C"><span id="translatedtitle">Saturn's Other <span class="hlt">Ring</span> Current</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crary, F. J.</p> <p>2014-04-01</p> <p>Saturn's main <span class="hlt">rings</span> orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the <span class="hlt">ring</span> particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the <span class="hlt">rings</span> suggests that its speed would be couppled to the keplarian velocity of the <span class="hlt">rings</span> themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the <span class="hlt">ring</span> plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's <span class="hlt">rings</span> have been reported by O'Donoghue et al., 2013, and interpreted as a result of <span class="hlt">ring</span> "rain", i.e. precipitating water group species from the <span class="hlt">rings</span> which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JMMM..316E.944V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JMMM..316E.944V"><span id="translatedtitle">Magnetoresistance of single Permalloy circular <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vavassori, P.; Busato, A.; Chiapatti, A.; di Bona, A.; Valeri, S.; Metlushko, V.; Ilic, B.</p> <p>2007-09-01</p> <p>We have measured magnetoresistance in single, 1 μm external diameter, Permalloy (Ni 80Fe 20) circular <span class="hlt">rings</span> with varied inner hole diameter of 150, 300, and 600 nm and film thickness of 25 nm. The Permalloy <span class="hlt">ring</span> structures and the 10-nm-thick, 250-nm-wide Au nanocontacts were fabricated on a SiO 2/Si substrate using e-beam lithography. Using a four contact geometry we studied the dependence of the magnetoresistance on the direction of the applied field. The experimental data are explained by considering only the conventional anisotropic magnetoresistance effect. Numerical simulations of the current distribution within the samples combined with micromagnetic simulations of the field dependent magnetization profile, yield good agreement with the experimental data. Upon increasing the inner hole diameter (viz. decreasing the <span class="hlt">ring</span> <span class="hlt">width</span>) the magnetoresistance measurements show a transition of the reversal process from the "vortex nucleation-displacement-annihilation" sequence to the "onion state-reversed onion state" sequence, typical of narrow nanorings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050000032','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050000032"><span id="translatedtitle">Piston <span class="hlt">Ring</span> Pressure Distribution</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhn, M.</p> <p>1943-01-01</p> <p>The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses, Of these internal engine components, the piston and piston <span class="hlt">rings</span> are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the components, The piston <span class="hlt">ring</span> is a well-known component and has been used in its present shape in the steam engine of the last century, Corresponding to its importance, the piston <span class="hlt">ring</span> has been a rich field for creative activity and it is noteworthy that in spite of this the <span class="hlt">ring</span> has maintained its shape through the many years. From the many and complicated designs which have been suggested as a packing between piston and cylinder wall hardly one suggestion has remained which does not resemble the original design of cast iron rectangular <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27257971','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27257971"><span id="translatedtitle">Climate-Driven Synchronized <span class="hlt">Growth</span> of Alpine Trees in the Southeast Tibetan Plateau.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Feifei; Fang, Keyan; Zhang, Fen; Dong, Zhipeng; Chen, Dan</p> <p>2016-01-01</p> <p>Knowledge about the spatiotemporal tree <span class="hlt">growth</span> variability and its associations with climate provides key insights into forest dynamics under future scenarios of climate change. We synthesized 17 tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies from four tree species at the high-elevation sites in the southeast Tibetan Plateau (SETP) to study the regional tree <span class="hlt">growth</span> variability and climate-<span class="hlt">growth</span> relationships. Despite of diverse habitats and different physiological characteristics of these species, these tree-<span class="hlt">ring</span> chronologies shared a significant common variance in SETP. An unprecedented increase in the shared variance is found along the latter half of the 20th century, coinciding with the enhancement of the frequency of extreme <span class="hlt">rings</span> among chronologies. It is found that minimum winter temperature tends to be the dominant climate for trees in this region. The site-specific responses in cold (1965-1980) and warm (1990-2005) intervals by means of Fuzzy Cmeans (FCM) clustering reveal that the remarkable enhancement of <span class="hlt">growth</span> synchrony among trees mainly occur in warm conditions. This is different from previous findings indicating that increased consistence among temperature sensitive tree <span class="hlt">rings</span> in cold periods. This may be related to the reduced temperature sensitivity of regional tree <span class="hlt">growth</span> as winter minimum temperature is lower than a certain threshold, which is in agreement with the "principle of ecological amplitude". In addition, it is worth noting that precipitation in June have started to restrain the tree <span class="hlt">growth</span> since the beginning of the 1980s, which is possibly an important contributor for synchronized <span class="hlt">growth</span> among trees in SETP. PMID:27257971</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4892591','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4892591"><span id="translatedtitle">Climate-Driven Synchronized <span class="hlt">Growth</span> of Alpine Trees in the Southeast Tibetan Plateau</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Feifei; Fang, Keyan; Zhang, Fen; Dong, Zhipeng; Chen, Dan</p> <p>2016-01-01</p> <p>Knowledge about the spatiotemporal tree <span class="hlt">growth</span> variability and its associations with climate provides key insights into forest dynamics under future scenarios of climate change. We synthesized 17 tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies from four tree species at the high-elevation sites in the southeast Tibetan Plateau (SETP) to study the regional tree <span class="hlt">growth</span> variability and climate-<span class="hlt">growth</span> relationships. Despite of diverse habitats and different physiological characteristics of these species, these tree-<span class="hlt">ring</span> chronologies shared a significant common variance in SETP. An unprecedented increase in the shared variance is found along the latter half of the 20th century, coinciding with the enhancement of the frequency of extreme <span class="hlt">rings</span> among chronologies. It is found that minimum winter temperature tends to be the dominant climate for trees in this region. The site-specific responses in cold (1965–1980) and warm (1990–2005) intervals by means of Fuzzy Cmeans (FCM) clustering reveal that the remarkable enhancement of <span class="hlt">growth</span> synchrony among trees mainly occur in warm conditions. This is different from previous findings indicating that increased consistence among temperature sensitive tree <span class="hlt">rings</span> in cold periods. This may be related to the reduced temperature sensitivity of regional tree <span class="hlt">growth</span> as winter minimum temperature is lower than a certain threshold, which is in agreement with the “principle of ecological amplitude”. In addition, it is worth noting that precipitation in June have started to restrain the tree <span class="hlt">growth</span> since the beginning of the 1980s, which is possibly an important contributor for synchronized <span class="hlt">growth</span> among trees in SETP. PMID:27257971</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5756118','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5756118"><span id="translatedtitle"><span class="hlt">Rings</span> in the solar system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pollack, J.B.; Cuzzi, J.N.</p> <p>1981-11-01</p> <p>Saturn, Jupiter, and Uranus have <span class="hlt">rings</span> with different structure and composition. The <span class="hlt">rings</span> consist of tiny masses in independent orbits. Photographs and data obtained by the Voyager project have aided in the understanding of Saturn's <span class="hlt">rings</span>. Spokes have been found in B <span class="hlt">ring</span> and boards, knots, and twist in F <span class="hlt">ring</span>. Particles on the order of a micrometer in size are believed to occur in F, B, and A <span class="hlt">rings</span>. The dominant component is water ice. The <span class="hlt">rings</span> of Uranus are narrow and separated by broad empty regions. The technique used to study them has been stellar occulation. Nothing is known of particle size. The dominant component is believed to be silicates rich in compounds that absorb sunlight. Jupiter's <span class="hlt">rings</span> consist of 3 main parts: a bright <span class="hlt">ring</span>, a diffuse disk, and a halo. Use of Pioneer 10 data and other techniques have indicated particle sizes on the order of several micrometers and some at least a centimeter in diameter. The architecture of the <span class="hlt">ring</span> system results from the interplay of a number of forces. These include gravitational forces due to moons outside the <span class="hlt">rings</span> and moonlets embedded in them, electromagnetic forces due to the planet's rotating magnetic field, and even the gentle forces exerted by the dilute gaseous medium in which the <span class="hlt">rings</span> rotate. Each of these forces is discussed. Several alternative explanations of how the <span class="hlt">rings</span> arose are considered. The primary difference in these hypotheses is the account of the relationship between the <span class="hlt">ring</span> particles of today and the primordial <span class="hlt">ring</span> material. (SC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990EOSTr..71..281V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990EOSTr..71..281V"><span id="translatedtitle"><span class="hlt">Rings</span> dominate western Gulf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez</p> <p></p> <p>Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of <span class="hlt">rings</span> of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core <span class="hlt">rings</span> pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The <span class="hlt">rings</span> migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140002358','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140002358"><span id="translatedtitle">Deployable Fresnel <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.</p> <p>2014-01-01</p> <p>Deployable Fresnel <span class="hlt">rings</span> (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment <span class="hlt">ring</span>. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting <span class="hlt">ring</span> or <span class="hlt">rings</span> of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone <span class="hlt">rings</span>. Gain enhancement using a single <span class="hlt">ring</span> is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-<span class="hlt">ring</span> DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRG..116.1015B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRG..116.1015B"><span id="translatedtitle">High-latitude tree <span class="hlt">growth</span> and satellite vegetation indices: Correlations and trends in Russia and Canada (1982-2008)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berner, Logan T.; Beck, Pieter S. A.; Bunn, Andrew G.; Lloyd, Andrea H.; Goetz, Scott J.</p> <p>2011-03-01</p> <p>Vegetation in northern high latitudes affects regional and global climate through energy partitioning and carbon storage. Spaceborne observations of vegetation, largely based on the normalized difference vegetation index (NDVI), suggest decreased productivity during recent decades in many regions of the Eurasian and North American boreal forests. To improve interpretation of NDVI trends over forest regions, we examined the relationship between NDVI from the advanced very high resolution radiometers and tree <span class="hlt">ring</span> <span class="hlt">width</span> measurements, a proxy of tree productivity. We collected tree core samples from spruce, pine, and larch at 22 sites in northeast Russia and northwest Canada. Annual <span class="hlt">growth</span> <span class="hlt">rings</span> were measured and used to generate site-level <span class="hlt">ring</span> <span class="hlt">width</span> index (RWI) chronologies. Correlation analysis was used to assess the association between RWI and summer NDVI from 1982 to 2008, while linear regression was used to examine trends in both measurements. The correlation between NDVI and RWI was highly variable across sites, though consistently positive (r = 0.43, SD = 0.19, n = 27). We observed significant temporal autocorrelation in both NDVI and RWI measurements at sites with evergreen conifers (spruce and pine), though weak autocorrelation at sites with deciduous conifers (larch). No sites exhibited a positive trend in both NDVI and RWI, although five sites showed negative trends in both measurements. While there are technological and physiological limitations to this approach, these findings demonstrate a positive association between NDVI and tree <span class="hlt">ring</span> measurements, as well as the importance of considering lagged effects when modeling vegetation productivity using satellite data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22167935','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22167935"><span id="translatedtitle">Effect of pine mistletoe on radial <span class="hlt">growth</span> of Crimean pine (Pinus nigra) in Turkey.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Catal, Yilmaz; Carus, Serdar</p> <p>2011-05-01</p> <p>In this study, the influence of infection by pine mistletoe (Viscum album L. subsp. austriacum (Wiesb.) Volmann) on the radial <span class="hlt">growth</span> of crimean pine (Pinus nigra Amold) in Turkey was investigated. We built local residual tree-<span class="hlt">ring-width</span> chronologies using dendrochronogical techniques. Tree <span class="hlt">ring</span> chronologies of uninfected (control) crimean pine were used to estimate potential radial <span class="hlt">growth</span> characteristics in the "infected" crimean pine (light, moderate and severe infection groups). In 2005, increment cores were collected from 26 infected and 19 control dominant or co-dominant trees and annual radial <span class="hlt">growth</span> indices from 1930-2005 were calculated for each infection group in a 14 point sampling. We compared radial <span class="hlt">growth</span> in the uninfected trees with mean regional chronology. We found a strong decrease in radial <span class="hlt">growth</span> in during the 1998-2005 period. The periodic average radial <span class="hlt">growth</span> reduction (in %) from 1998 to 2005, respectively, were 0 for control, 26 for light, 39 for moderate and 63 for severe infection groups. It can be especially concluded that a severe degree of pine mistletoe attack has a negative effect on radial <span class="hlt">growth</span> of the infected crimean pine trees. PMID:22167935</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70169111','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70169111"><span id="translatedtitle"><span class="hlt">Growth</span>-climate relationships across topographic gradients in the northern Great Lakes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dymond, S.F.; D'Amato, A.W.; Kolka, R.K.; Bolstad, P.V.; Sebestyen, S.D.; Bradford, John B.</p> <p>2015-01-01</p> <p>Climatic conditions exert important control over the <span class="hlt">growth</span>, productivity, and distribution of forests, and characterizing these relationships is essential for understanding how forest ecosystems will respond to climate change. We used dendrochronological methods to develop climate–<span class="hlt">growth</span> relationships for two dominant species, Populus tremuloides (quaking aspen) and Pinus resinosa (red pine), in the upper Great Lakes region to understand how climate and water availability influence annual forest productivity. Trees were sampled along a topographic gradient at the Marcell Experimental Forest (Minnesota, USA) to assess <span class="hlt">growth</span> response to variations in temperature and different water availability metrics (precipitation, potential evapotranspiration (PET), cumulative moisture index (CMI), and soil water storage). Climatic variables were able to explain 33–58% of the variation in annual <span class="hlt">growth</span> (as measured by <span class="hlt">ring-width</span> increment) for quaking aspen and 37–74% of the variation for red pine. Climate–<span class="hlt">growth</span> relationships were influenced by topography for quaking aspen but not for red pine. Annual <span class="hlt">ring</span> <span class="hlt">growth</span> for quaking aspen decreased with June CMI on ridges, decreased with temperature in the November prior to the growing season on sideslopes, and decreased with June PET on toeslopes. Red pine <span class="hlt">growth</span> increased with increasing July PET across all topographic positions. These results indicate the sensitivity of both quaking aspen and red pine to local climate and show several vulnerabilities of these species to shifts in water supply and temperature because of climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27398609','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27398609"><span id="translatedtitle">Sliding-<span class="hlt">Ring</span> Catenanes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernando, Isurika R; Frasconi, Marco; Wu, Yilei; Liu, Wei-Guang; Wasielewski, Michael R; Goddard, William A; Stoddart, J Fraser</p> <p>2016-08-17</p> <p>Template-directed protocols provide a routine approach to the synthesis of mechanically interlocked molecules (MIMs), in which the mechanical bonds are stabilized by a wide variety of weak interactions. In this Article, we describe a strategy for the preparation of neutral [2]catenanes with sliding interlocked electron-rich <span class="hlt">rings</span>, starting from two degenerate donor-acceptor [2]catenanes, consisting of a tetracationic cyclobis(paraquat-p-phenylene) cyclophane (CBPQT(4+)) and crown ethers containing either (i) hydroquinone (HQ) or (ii) 1,5-dioxynaphthalene (DNP) recognition units and carrying out four-electron reductions of the cyclophane components to their neutral forms. The donor-acceptor interactions between the CBPQT(4+) <span class="hlt">ring</span> and both HQ and DNP units present in the crown ethers that stabilize the [2]catenanes are weakened upon reduction of the cyclophane components to their radical cationic states and are all but absent in their fully reduced states. Characterization in solution performed by UV-vis, EPR, and NMR spectroscopic probes reveals that changes in the redox properties of the [2]catenanes result in a substantial decrease of the energy barriers for the circumrotation and pirouetting motions of the interlocked <span class="hlt">rings</span>, which glide freely through one another in the neutral states. The solid-state structures of the fully reduced catenanes reveal profound changes in the relative dispositions of the interlocked <span class="hlt">rings</span>, with the glycol chains of the crown ethers residing in the cavities of the neutral CBPQT(0) <span class="hlt">rings</span>. Quantum mechanical investigations of the energy levels associated with the four different oxidation states of the catenanes support this interpretation. Catenanes and rotaxanes with sliding <span class="hlt">rings</span> are expected to display unique properties. PMID:27398609</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sensor&pg=6&id=EJ860668','ERIC'); return false;" href="http://eric.ed.gov/?q=sensor&pg=6&id=EJ860668"><span id="translatedtitle">Measuring Slit <span class="hlt">Width</span> and Separation in a Diffraction Experiment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gan, K. K.; Law, A. T.</p> <p>2009-01-01</p> <p>We present a procedure for measuring slit <span class="hlt">width</span> and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit <span class="hlt">widths</span> and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4131778','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4131778"><span id="translatedtitle">GUARD <span class="hlt">RING</span> SEMICONDUCTOR JUNCTION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Goulding, F.S.; Hansen, W.L.</p> <p>1963-12-01</p> <p>A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard <span class="hlt">ring</span> that encircles the central region. Noise signal currents are shunted through the guard <span class="hlt">ring</span>, leaving the central region free from such currents. (AEC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJS..223...27P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJS..223...27P"><span id="translatedtitle"><span class="hlt">Ringed</span> Accretion Disks: Instabilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pugliese, D.; Stuchlík, Z.</p> <p>2016-04-01</p> <p>We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a <span class="hlt">ringed</span> accretion disk, made up by several tori (<span class="hlt">rings</span>) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6982234','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6982234"><span id="translatedtitle">Unidirectional <span class="hlt">ring</span> lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hohimer, J.P.; Craft, D.C.</p> <p>1994-09-20</p> <p>Unidirectional <span class="hlt">ring</span> lasers formed by integrating nonreciprocal optical elements into the resonant <span class="hlt">ring</span> cavity is disclosed. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction. 21 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869513','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869513"><span id="translatedtitle">Unidirectional <span class="hlt">ring</span> lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hohimer, John P.; Craft, David C.</p> <p>1994-01-01</p> <p>Unidirectional <span class="hlt">ring</span> lasers formed by integrating nonreciprocal optical elements into the resonant <span class="hlt">ring</span> cavity. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...03..163B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...03..163B"><span id="translatedtitle">The covariant chiral <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bourget, Antoine; Troost, Jan</p> <p>2016-03-01</p> <p>We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N = (4 , 4) supersymmetry in two dimensions. For seed target spaces K3 and T 4, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral <span class="hlt">ring</span> respectively. Via string dualities, we relate the transformation properties of the chiral <span class="hlt">ring</span> under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3493716','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3493716"><span id="translatedtitle">Self-assembled smooth muscle cell tissue <span class="hlt">rings</span> exhibit greater tensile strength than cell-seeded fibrin or collagen gel <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Adebayo, Olufunmilayo; Gwyther, Tracy A.; Hu, Jason Z.; Billiar, Kristen L.; Rolle, Marsha W.</p> <p>2012-01-01</p> <p>In this study, we created self-assembled smooth muscle cell (SMC) tissue <span class="hlt">rings</span> (comprised entirely of cells and cell-derived matrix; CDM) and compared their structure and material properties with tissue <span class="hlt">rings</span> created from SMC-seeded fibrin or collagen gels. All tissue <span class="hlt">rings</span> were cultured statically for 7 days in supplemented <span class="hlt">growth</span> medium (with ε-amino caproic acid, ascorbic acid, and insulin-transferrin-selenium), prior to uniaxial tensile testing and histology. Self-assembled CDM <span class="hlt">rings</span> exhibited ultimate tensile strength and stiffness values that were two-fold higher than fibrin gel and collagen gel <span class="hlt">rings</span>. Tensile testing of CDM, fibrin gel and collagen gel <span class="hlt">rings</span> treated with deionized water to lyse cells showed little to no change in mechanical properties relative to untreated <span class="hlt">ring</span> samples, indicating that the ECM dominates the measured <span class="hlt">ring</span> mechanics. In addition, CDM <span class="hlt">rings</span> cultured in supplemented <span class="hlt">growth</span> medium were significantly stronger than CDM <span class="hlt">rings</span> cultured in standard, unsupplemented <span class="hlt">growth</span> medium. These results illustrate the potential utility of self-assembled cell <span class="hlt">rings</span> as model CDM constructs for tissue engineering and biomechanical analysis of ECM material properties. PMID:22865465</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171615','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171615"><span id="translatedtitle">Saturn's <span class="hlt">Rings</span>, the Yarkovsky Effects, and the <span class="hlt">Ring</span> of Fire</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubincam, David Parry</p> <p>2004-01-01</p> <p>The dimensions of Saturn's A and B <span class="hlt">rings</span> may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the <span class="hlt">rings</span> between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C <span class="hlt">ring</span> may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous <span class="hlt">Ring</span> of Fire around Saturn's equator. The <span class="hlt">ring</span> system may be young: in the past heat flow from Saturn's interior much above its present value would not permit <span class="hlt">rings</span> to exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3951L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3951L"><span id="translatedtitle">Exploring the 'divergence' problem using a simple process-based model of tree <span class="hlt">growth</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Guangqi; Harrison, Sandy P.; Prentice, I. Colin</p> <p>2016-04-01</p> <p>There has been an apparent change in the sensitivity of tree <span class="hlt">rings</span> to temperature in northern extratropical regions since the 1980s - a phenomenon often referred to as the divergence problem. Several potential explanations have been suggested to explain the decoupling between <span class="hlt">ring</span> <span class="hlt">width</span> (or density) and temperature, including exceedance of limiting temperature thresholds with global warming, changes in light availability with global dimming, the increasing importance of soil or atmospheric drought as a limitation to tree <span class="hlt">growth</span>, or the CO2 'fertilization effect'. Here we use a simple, process-based tree-<span class="hlt">growth</span> and carbon allocation model to explore these hypotheses. While changes in light availability and drought contribute to explain the declining influence of temperature on tree <span class="hlt">growth</span>, the most important factor is changes in carbon allocation to roots and mycorrhizae in response to increasing [CO2] and the demand for increased nutrients to support photosynthesis. The magnitude of the increase in below-ground allocation, and hence the relative importance of this mechanism versus climate in controlling tree radial <span class="hlt">growth</span>, appears to be influenced by nutrient and water availability. The potential importance of changes in carbon allocation challenges the use of statistical models for climate reconstructions from tree <span class="hlt">rings</span> during intervals when [CO2] was different from historical values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21303812','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21303812"><span id="translatedtitle">Turner syndrome isochromosome karyotype correlates with decreased dental crown <span class="hlt">width</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rizell, S; Barrenäs, M-L; Andlin-Sobocki, A; Stecksén-Blicks, C; Kjellberg, H</p> <p>2012-04-01</p> <p>The aim of this project was to study possible influences of Turner syndrome (TS) karyotype and the number of X chromosomes with intact short arm (p-arm) on dental crown <span class="hlt">width</span>. Primary and permanent mesio-distal crown <span class="hlt">width</span> was measured on plaster casts from 112 TS females. The influence on crown <span class="hlt">width</span> of four karyotypes: 1. monosomy (45,X), 2. mosaic (45,X/46,XX), 3. isochromosome, and 4. other, and the number of intact X chromosomal p-arms were investigated. In comparisons between karyotypes, statistically significant differences were found for isochromosome karyotype maxillary second premolars, canines, laterals, mandibular first premolars, and canines, indicating that this karyotype was the most divergent as shown by the most reduced crown <span class="hlt">width</span>. When each karyotype group were compared versus controls, all teeth in the isochromosome group were significantly smaller than controls (P < 0.01-0.001). The 45,X/46,XX karyotype expressed fewer and smaller differences from controls, while 45,X individuals seemed to display an intermediate tooth <span class="hlt">width</span> compared with 45,X/46,XX and isochromosomes. No significant difference in crown <span class="hlt">width</span> was found comparing the groups with one or two intact X chromosomal p-arms. Both primary and permanent teeth proved to have a significantly smaller crown <span class="hlt">width</span> in the entire group of TS females compared to healthy females. We conclude that the isochromosome group deviates most from other karyotypes and controls, exhibiting the smallest dental crown <span class="hlt">width</span>, while individuals with 45,X/46,XX mosaicism seemed to have a less affected crown <span class="hlt">width</span>. An influence of the number of intact p-arms on crown <span class="hlt">width</span> could not be demonstrated in this study. PMID:21303812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EOSTr..94Q.336S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EOSTr..94Q.336S"><span id="translatedtitle">Do tree <span class="hlt">ring</span> chronologies have missing <span class="hlt">rings</span> that distort volcanic cooling signal?: Fixing tree <span class="hlt">ring</span> chronologies yields closer agreement with models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, Colin</p> <p>2013-09-01</p> <p>Climate models generally show that when a massive volcano erupts, scattering reflective aerosols across the globe, the planet's temperature declines for up to a few years. However, when researchers look at reconstructed temperature records built on annual tree <span class="hlt">ring</span> measurements, this volcanic cooling often appeared much weaker than expected or was nonexistent. In a new study reanalyzing regional tree <span class="hlt">ring</span> <span class="hlt">growth</span> records, Mann et al. provide a possible explanation for the absence of the cooling effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMPP43A1659B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMPP43A1659B"><span id="translatedtitle">A new method for separating the climatic and biological trend components from tree <span class="hlt">ring</span> series, with implications for paleoclimate reconstructions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bouldin, J.</p> <p>2010-12-01</p> <p>In the reconstruction of past climates from tree <span class="hlt">rings</span> multi-decadal to multi-centennial periods, one longstanding problem is the confounding of the natural biological <span class="hlt">growth</span> trend of the tree with any existing long term trends in the climate. No existing analytical method is capable of resolving these two change components, so it remains unclear how accurate existing <span class="hlt">ring</span> series standardizations are, and by implication, climate reconstructions based upon them. For example, dendrochronological at the ITRDB are typically standardized by detrending, at each site, each individual tree core, using a relatively stiff deterministic function such as a negative exponential curve or smoothing spline. Another approach, referred to as RCS (Regional Curve Standardization) attempts to solve some problems of the individual series detrending, by constructing a single <span class="hlt">growth</span> curve from the aggregated cambial ages of the <span class="hlt">rings</span> of the cores at a site (or collection of sites). This curve is presumed to represent the “ideal” or expected <span class="hlt">growth</span> of the trees from which it is derived. Although an improvement in some respects, this method will be degraded in direct proportion to the lack of a mixture of tree sizes or ages throughout the span of the chronology. I present a new method of removing the biological curve from tree <span class="hlt">ring</span> series, such that temporal changes better represent the environmental variation captured by the tree <span class="hlt">rings</span>. The method institutes several new approaches, such as the correction for the estimated number of missed <span class="hlt">rings</span> near the pith, and the use of tree size and <span class="hlt">ring</span> area relationships instead of the traditional tree ages and <span class="hlt">ring</span> <span class="hlt">widths</span>. The most important innovation is a careful extraction of the existing information on the relationship between tree size (basal area) and <span class="hlt">ring</span> area that exists within each single year of the chronology. This information is, by definition, not contaminated by temporal climatic changes, and so when removed, leaves the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26835779','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26835779"><span id="translatedtitle">Box-like filter response using multimode single-<span class="hlt">ring</span> microresonators.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>El-Sabban, Salwa; Wageeh, Amr; Khalil, Diaa</p> <p>2016-01-10</p> <p>In this work we suggest a new technique to form a box-like filter response using a single microring resonator. The new design is based on exploiting the multimode propagation in the <span class="hlt">ring</span>. The technique is implemented in the case of a two-mode <span class="hlt">ring</span> resonator for different designs. The obtained results show that the new designs allow getting 1 to 10 dB spectral <span class="hlt">width</span> shape factor better than 0.4, as verified by the FDTD simulation at different wavelengths and for different spectral <span class="hlt">widths</span>. This new design methodology opens the door for more compact optical filters with controlled box-like response. PMID:26835779</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26685584','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26685584"><span id="translatedtitle">[Difference in responses of major tree species <span class="hlt">growth</span> to climate in the Miyaluo Mountains, western Sichuan, China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Ming-ming; Zhang, Yuan-dong; Wang, Xiao-chun; Liu, Shi-rong</p> <p>2015-08-01</p> <p>To explore the responses of different tree species <span class="hlt">growth</span> to climate change in the semi-humid region of the eastern Tibetan Plateau, we investigated climate-<span class="hlt">growth</span> relationships of Tsuga chinensis, Abies faxoniana, Picea purpurea at an altitude of 3000 m (low altitude) and A. faxoniana and Larix mastersiana at an altitude of 4000 m (high altitude) using tree <span class="hlt">ring-width</span> chronologies (total of 182 cores) developed from Miyaluo, western Sichuan, China. Five residual chronologies were developed from the cross-dated <span class="hlt">ring</span> <span class="hlt">width</span> series using the program ARSTAN, and the relationships between monthly climate variables and tree-<span class="hlt">ring</span> index were analyzed. Results showed that the chronologies of trees at low altitudes were negatively correlated with air temperature but positively with precipitation in April and May. This indicated that drought stress limited tree <span class="hlt">growth</span> at low altitude, but different tree species showed significant variations. T. chinensis was most severely affected by drought stress, followed by A. faxoniana and P. purpurea. Trees at high altitude were mainly affected by growing season temperature. Tree-<span class="hlt">ring</span> index of A. faxoniana was positively correlated with monthly minimum temperature in February and July of the current year and monthly maximum temperature in October of the previous year. Radial <span class="hlt">growth</span> of L. mastersiana was positively correlated with monthly maximum temperature in May, and negatively with monthly mean temperature in February and monthly minimum temperature in March. In recent decadal years, the climate in northeast Tibetan Plateau had a warming and drying trend. If this trend continues, we could deduce that P. purpurea should grow faster than T. chinensis and A. faxoniana at low altitudes, while A. faxoniana would benefit more from global warming at high altitudes. PMID:26685584</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27379108','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27379108"><span id="translatedtitle">Flood-<span class="hlt">Ring</span> Formation and Root Development in Response to Experimental Flooding of Young Quercus robur Trees.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Copini, Paul; den Ouden, Jan; Robert, Elisabeth M R; Tardif, Jacques C; Loesberg, Walter A; Goudzwaard, Leo; Sass-Klaassen, Ute</p> <p>2016-01-01</p> <p>Spring flooding in riparian forests can cause significant reductions in earlywood-vessel size in submerged stem parts of <span class="hlt">ring</span>-porous tree species, leading to the presence of 'flood <span class="hlt">rings</span>' that can be used as a proxy to reconstruct past flooding events, potentially over millennia. The mechanism of flood-<span class="hlt">ring</span> formation and the relation with timing and duration of flooding are still to be elucidated. In this study, we experimentally flooded 4-year-old Quercus robur trees at three spring phenophases (late bud dormancy, budswell, and internode expansion) and over different flooding durations (2, 4, and 6 weeks) to a stem height of 50 cm. The effect of flooding on root and vessel development was assessed immediately after the flooding treatment and at the end of the growing season. <span class="hlt">Ring</span> <span class="hlt">width</span> and earlywood-vessel size and density were measured at 25- and 75-cm stem height and collapsed vessels were recorded. Stem flooding inhibited earlywood-vessel development in flooded stem parts. In addition, flooding upon budswell and internode expansion led to collapsed earlywood vessels below the water level. At the end of the growing season, mean earlywood-vessel size in the flooded stem parts (upon budswell and internode expansion) was always reduced by approximately 50% compared to non-flooded stem parts and 55% compared to control trees. This reduction was already present 2 weeks after flooding and occurred independent of flooding duration. Stem and root flooding were associated with significant root dieback after 4 and 6 weeks and mean radial <span class="hlt">growth</span> was always reduced with increasing flooding duration. By comparing stem and root flooding, we conclude that flood <span class="hlt">rings</span> only occur after stem flooding. As earlywood-vessel development was hampered during flooding, a considerable number of narrow earlywood vessels present later in the season, must have been formed after the actual flooding events. Our study indicates that root dieback, together with strongly reduced hydraulic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=nasa&pg=7&id=EJ809647','ERIC'); return false;" href="http://eric.ed.gov/?q=nasa&pg=7&id=EJ809647"><span id="translatedtitle">Reading, Writing, and <span class="hlt">Rings</span>!</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Aschbacher, Pamela; Li, Erika; Hammon, Art</p> <p>2008-01-01</p> <p>"Reading, Writing, and <span class="hlt">Rings</span>!" was created by a team of elementary teachers, literacy experts, and scientists in order to integrate science and literacy. These free units bring students inside NASA's Cassini-Huygens mission to Saturn. The authors--a science teacher and education outreach specialist and two evaluators of educational programs--have…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/279515','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/279515"><span id="translatedtitle">Field reversed ion <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sudan, R.N.; Omelchenko, Y.A.</p> <p>1995-09-01</p> <p>In typical field-reversed ion <span class="hlt">ring</span> experiments, an intense annular ion beam is injected across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Assuming the characteristic ionization time is much shorter than the long ({ital t}{approx_gt}2{pi}/{Omega}{sub {ital i}}) beam evolution time scale, we investigate the formation of an ion <span class="hlt">ring</span> in the background plasma followed by field reversal, using a 21/2-D hybrid, PIC code FIRE, in which the beam and background ions are treated as particles and the electrons as a massless fluid. We show that beam bunching and trapping occurs downstream in a ramped magnetic field for an appropriate set of experimental parameters. We find that a compact ion <span class="hlt">ring</span> is formed and a large field reversal {zeta}={delta}{ital B}/{ital B}{approx_gt}1 on axis develops. We also observe significant deceleration of the <span class="hlt">ring</span> on reflection due to the transfer of its axial momentum to the background ions, which creates favorable trapping conditions. {copyright} {ital 1995 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920001716','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920001716"><span id="translatedtitle">Models of planetary <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esposito, L. W.; Brophy, T. G.; Stewart, Glen R.; Yanamandra-Fisher, P. A.</p> <p>1991-01-01</p> <p>The Voyager occultations provide several uniform and high quality data sets for Saturn, Uranus, and Neptune. These data are intercompared, and theoretical models for the particle sizes and the particle transport are developed. The major topics covered include: <span class="hlt">ring</span> size distribution, torques and resonances, and satellite wakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830000665&hterms=electric+tool&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectric%2Btool','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830000665&hterms=electric+tool&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectric%2Btool"><span id="translatedtitle">Tool Support <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, D. F.</p> <p>1984-01-01</p> <p>Tool support <span class="hlt">ring</span> requires only single repositioning to give broaching tool access to series of 66 holes located on circle. Permits use of tools designed for hand-held use (such as electric drill) where less portable setup (such as milling machine) otherwise required.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850000108&hterms=EDM&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEDM','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850000108&hterms=EDM&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEDM"><span id="translatedtitle">Flushing <span class="hlt">Ring</span> for EDM</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Earwood, L.</p> <p>1985-01-01</p> <p>Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to <span class="hlt">ring</span> placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA06755&hterms=Jellyfishes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DJellyfishes','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA06755&hterms=Jellyfishes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DJellyfishes"><span id="translatedtitle"><span class="hlt">Ring</span> of Stellar Death</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p><p/> This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant <span class="hlt">ring</span> of material (red) slightly offset from the cloud's core. This clumpy <span class="hlt">ring</span> consists of material that was expelled from the aging star. <p/> The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space. <p/> In this image, the expelled gases appear green, and the <span class="hlt">ring</span> of expelled material appears red. Astronomers believe the <span class="hlt">ring</span> is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars. <p/> This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175414','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175414"><span id="translatedtitle"><span class="hlt">Ring</span> laser scatterometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ackermann, Mark; Diels, Jean-Claude</p> <p>2005-06-28</p> <p>A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a <span class="hlt">ring</span> laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6081393','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6081393"><span id="translatedtitle">Exotic damping <span class="hlt">ring</span> lattices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Palmer, R.B.</p> <p>1987-05-01</p> <p>This paper looks at, and compares three types of damping <span class="hlt">ring</span> lattices: conventional, wiggler lattice with finite ..cap alpha.., wiggler lattice with ..cap alpha.. = 0, and observes the attainable equilibrium emittances for the three cases assuming a constraint on the attainable longitudinal impedance of 0.2 ohms. The emittance obtained are roughly in the ratio 4:2:1 for these cases.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=gram&pg=2&id=EJ770961','ERIC'); return false;" href="http://eric.ed.gov/?q=gram&pg=2&id=EJ770961"><span id="translatedtitle">Making Molecular Borromean <span class="hlt">Rings</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Pentecost, Cari D.; Tangchaivang, Nichol; Cantrill, Stuart J.; Chichak, Kelly S.; Peters, Andrea J.; Stoddart, Fraser J.</p> <p>2007-01-01</p> <p>A procedure that requires seven 4-hour blocks of time to allow undergraduate students to prepare the molecular Borromean <span class="hlt">rings</span> (BRs) on a gram-scale in 90% yield is described. The experiment would serve as a nice capstone project to culminate any comprehensive organic laboratory course and expose students to fundamental concepts, symmetry point…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009at12.book..261A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009at12.book..261A"><span id="translatedtitle">Direct numerical simulation of a turbulent vortex <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Archer, P. J.; Thomas, T. G.; Coleman, G. N.</p> <p></p> <p>Engineers have been fascinated by vortex <span class="hlt">rings</span> for over a hundred years, due to their numerous engineering and biological applications and their presence as a constituent of fully turbulent flow. Although the laminar <span class="hlt">ring</span> has received much attention, the turbulent vortex <span class="hlt">ring</span> is less well understood, due to the difficulty in its visualisation and measurement. Glezer and Coles [1] used ensemble averaging of experimental data to show that the radial expansion, circulation decay and slowing of the turbulent <span class="hlt">ring</span> occur in a self-similar fashion. Circulation decreases in a staircase-like fashion [2] as the <span class="hlt">ring</span> sheds hairpin vortices [3] into a wake. The radial <span class="hlt">growth</span> of the <span class="hlt">ring</span> is due to a slight excess in the amount of entrainment over detrainment[1]. The movement of dye within the <span class="hlt">ring</span> suggests the existence of secondary vortices that wrap around the core, influencing the local entrainment, detrainment and production of turbulence [1]. In previous work [4], we investigated the laminar evolution of the <span class="hlt">ring</span> and focused on the development of the Tsai-Widnall-Moore-Saffman (TWMS) instability [5, 6], and transition to turbulence. Here, we examine the temporal development of the turbulent vortex <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.1047M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.1047M"><span id="translatedtitle">Teberda valley runoff variability (AD 1797-2003) based on tree-<span class="hlt">ring</span> reconstruction (Northern Caucasus, Russia)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matskovskiy, V. V.; Dolgova, E. A.; Solomina, O. N.</p> <p>2009-04-01</p> <p>In this paper we provide a new tree-<span class="hlt">ring</span> based runoff reconstruction for Teberda river for 1797-2003. Teberda river is a tributary of Kuban' (Azov Sea basin), 60 km long with the watershed surface equal to 1080 km2. 60% of runoff occurs in summer, 17% - in the fall, 5% - in winter, 18% - in spring. 55,8% of runoff (at Teberda hydrological station) is provided by snow and ice melt (Lurye 2000). No statistically significant trend is identified in the Teberda runoff records in 1930-2000 despite of some important climatic and environmental changes occurred in this period in the Northern Caucasus, namely a general warming in winter, increase in solid precipitation and recession of glaciers. Tree-<span class="hlt">ring</span> properties were successfully used previously to reconstruct streamflow (Stockton and Jacoby, 1976, Woodhouse et al., 2006) in the regions where drought influence both tree <span class="hlt">growth</span> and river runoff regime. In the Northern Caucasus, even at the upper tree limit pine and spruce <span class="hlt">growth</span> is largely limited by the availability of water (Dologva et al., 2007). The correlation between Pinus silvestris <span class="hlt">ring</span> <span class="hlt">width</span> and June-July Teberda river runoff is 0.4, while it increases up to 0.69 for 11-years running mean. We used linear regression of instrumental records of Teberda runoff (1927-2000) and first principal component of the pine <span class="hlt">ring</span> <span class="hlt">width</span> chronologies from the same valley to reconstruct the June-July runoff for the period 1797-2003. Our chronology is two centuries longer, but its reliable portion (EPS > 0.8) begin in the late 18th century. We used cross-validation to verify the reconstruction, so the correlation coefficient is 0.72 and mean difference is 23.13 (52% of interquartile range) between reconstruction and instrumental record for the verification period. The reconstruction reproduces well the general trends in runoff variability, but slightly underestimates the amplitude of the runoff positive anomalies in 1940s. The positive peaks of reconstructed runoff are centered</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRC..111.9039F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRC..111.9039F"><span id="translatedtitle">Somali Current <span class="hlt">rings</span> in the eastern Gulf of Aden</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fratantoni, David M.; Bower, Amy S.; Johns, William E.; Peters, Hartmut</p> <p>2006-09-01</p> <p>New satellite-based observations reveal that westward translating anticyclonic <span class="hlt">rings</span> are generated as a portion of the Somali Current accelerates northward through the Socotra Passage near the mouth of the Gulf of Aden. <span class="hlt">Rings</span> thus formed exhibit azimuthal geostrophic velocities exceeding 50 cm/s, are comparable in overall diameter to the <span class="hlt">width</span> of the Gulf of Aden (250 km), and translate westward into the gulf at 5-8 cm/s. <span class="hlt">Ring</span> generation is most notable in satellite ocean color imagery in November immediately following the transition between southwest (boreal summer) and northeast (winter) monsoon regimes. The observed <span class="hlt">rings</span> contain anomalous fluid within their core which reflects their origin in the equator-crossing Somali Current system. Estimates of Socotra Passage flow variability derived from satellite altimetry provide evidence for a similar <span class="hlt">ring</span> generation process in May following the winter-to-summer monsoon transition. Cyclonic recirculation eddies are observed to spin up on the eastern flank of newly formed <span class="hlt">rings</span> with the resulting vortex pair translating westward together. Recent shipboard and Lagrangian observations indicate that vortices of both sign have substantial vertical extent and may dominate the lateral circulation at all depths in the eastern Gulf of Aden.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24670644','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24670644"><span id="translatedtitle">A <span class="hlt">ring</span> system detected around the Centaur (10199) Chariklo.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Braga-Ribas, F; Sicardy, B; Ortiz, J L; Snodgrass, C; Roques, F; Vieira-Martins, R; Camargo, J I B; Assafin, M; Duffard, R; Jehin, E; Pollock, J; Leiva, R; Emilio, M; Machado, D I; Colazo, C; Lellouch, E; Skottfelt, J; Gillon, M; Ligier, N; Maquet, L; Benedetti-Rossi, G; Ramos Gomes, A; Kervella, P; Monteiro, H; Sfair, R; El Moutamid, M; Tancredi, G; Spagnotto, J; Maury, A; Morales, N; Gil-Hutton, R; Roland, S; Ceretta, A; Gu, S-h; Wang, X-b; Harpsøe, K; Rabus, M; Manfroid, J; Opitom, C; Vanzi, L; Mehret, L; Lorenzini, L; Schneiter, E M; Melia, R; Lecacheux, J; Colas, F; Vachier, F; Widemann, T; Almenares, L; Sandness, R G; Char, F; Perez, V; Lemos, P; Martinez, N; Jørgensen, U G; Dominik, M; Roig, F; Reichart, D E; LaCluyze, A P; Haislip, J B; Ivarsen, K M; Moore, J P; Frank, N R; Lambas, D G</p> <p>2014-04-01</p> <p>Hitherto, <span class="hlt">rings</span> have been found exclusively around the four giant planets in the Solar System. <span class="hlt">Rings</span> are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a <span class="hlt">ring</span> system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ±  9 kilometres (ref. 2). There are two dense <span class="hlt">rings</span>, with respective <span class="hlt">widths</span> of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the <span class="hlt">ring</span> is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the <span class="hlt">rings</span> are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites. PMID:24670644</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020041256&hterms=dolphin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddolphin','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020041256&hterms=dolphin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddolphin"><span id="translatedtitle"><span class="hlt">Ring</span> Bubbles of Dolphins</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)</p> <p>1996-01-01</p> <p>The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex <span class="hlt">ring</span> bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex <span class="hlt">ring</span> in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex <span class="hlt">ring</span> travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex <span class="hlt">ring</span>. Often, the dolphin would knock-off a smaller <span class="hlt">ring</span> bubble from the larger <span class="hlt">ring</span> (this also involves vortex reconnection) and steer the smaller <span class="hlt">ring</span> around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex <span class="hlt">ring</span>, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a <span class="hlt">ring</span> when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016nova.pres.1472K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016nova.pres.1472K&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Rings</span> from Close Encounters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kohler, Susanna</p> <p>2016-09-01</p> <p>Weve recently discovered narrow sets of <span class="hlt">rings</span> around two minor planets orbiting in our solar system. How did these <span class="hlt">rings</span> form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected <span class="hlt">Ring</span> SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow <span class="hlt">ring</span> systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have <span class="hlt">rings</span>. But how did these <span class="hlt">rings</span> form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the <span class="hlt">rings</span> were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1007808','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1007808"><span id="translatedtitle">SIMULATION STUDY AND INITIAL TEST OF THESNS <span class="hlt">RING</span> RF SYSTEM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, Yan; Ma, Hengjie; Holmes, Jeffrey A; Champion, Mark; Chu, Paul; Cousineau, Sarah M; Hardek, Thomas W; Plum, Michael A; Danilov, Viatcheslav; Piller, Chip</p> <p>2008-01-01</p> <p>The rfsimulator code was developed for the study of the Spallation Neutron Source (SNS) dual-harmonic <span class="hlt">ring</span> RF control. It uses time-domain solvers to compute beam-cavity interactions and FFT methods to simulate the time responses of the linear RF system. The important elements of the system considered in the model include beam loading, dynamic cavity detuning, circuit bandwidth, loop delay, proportional-integral controller for feedback and adaptive feed forward, stochastic noise, <span class="hlt">width</span>-in-turn loop parameter change, beam current fluctuation, and bunch leakage. As the beam power increases, beam loss in the <span class="hlt">ring</span> goes up and thus precise control of the bunching RF phase and amplitude is required to limit beam loss. The code will help in the development of a functional RF control and in achieving the goal of minimizing beam loss in the accumulator <span class="hlt">ring</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/1001146','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/1001146"><span id="translatedtitle">Climate response among <span class="hlt">growth</span> increments of fish and trees</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Guyette, R.P.; Rabeni, C.F.</p> <p>1995-01-01</p> <p>Significant correlations were found among the annual <span class="hlt">growth</span> increments of stream fish, trees, and climate variables in the Ozark region of the United States. The variation in annual <span class="hlt">growth</span> increments of rock bass (Ambloplites rupestris) from the Jacks Fork River was significantly correlated over 22 years with the <span class="hlt">ring</span> <span class="hlt">width</span> of four tree species: white oak (Quercus alba), post oak (Quercus stellata), shortleaf pine (Pinus echinata) and eastern red cedar (Juniperus virginiana). Rock bass <span class="hlt">growth</span> and tree <span class="hlt">growth</span> were both significantly correlated with July rainfall and stream discharge. Variations in annual <span class="hlt">growth</span> of smallmouth bass (Micropterus dolomieu) from four streams were significantly correlated over 29 years (1939-1968) with mean May maximum air temperature but not with tree <span class="hlt">growth</span>. The magnitude and significance of correlations among <span class="hlt">growth</span> increments from fish and trees imply that conditions such as topography, stream gradient, organism age, and the distribution of a population relative to its geographic range can influence the climatic response of an organism. The timing and intensity of climatic variables may produce different responses among closely related species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040171218&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040171218&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Saturn's <span class="hlt">Rings</span>, the Yarkovsky Effects, and the <span class="hlt">Ring</span> of Fire</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubincam, David</p> <p>2004-01-01</p> <p>Saturn's icy <span class="hlt">ring</span> particles, with their low thermal conductivity, are almost ideal for the operation of the Yarkovsky effects. The dimensions of Saturn's A and B <span class="hlt">rings</span> may be determined by a near balancing of the seasonal Yarkovsky effect with the Yarkovsky- Schach effect. The two effects, which are photon thrust due to temperature gradients, may confine the A and B <span class="hlt">rings</span> to within their observed dimensions. The C <span class="hlt">ring</span> may be sparsely populated with icy particles because Yarkovsky drag has pulled them into Saturn, leaving the more slowly orbitally decaying rocky particles. Icy <span class="hlt">ring</span> particles ejected from the B <span class="hlt">ring</span> and passing through the C <span class="hlt">ring</span>, as well as some of the slower rocky particles, should fall on Saturn's equator, where they may create a luminous "<span class="hlt">Ring</span> of Fire" around Saturn's equator. This predicted <span class="hlt">Ring</span> of Fire may be visible to Cassini's camera. Curiously, the speed of outwards Yarkovsky orbital evolution appears to peak near the Cassini Division. The connection between the two is not clear. D. Nesvorny has speculated that the resonance at the outer edge of the B <span class="hlt">ring</span> may impede particles from evolving via Yarkovsky across the Division. If supply from the B <span class="hlt">ring</span> is largely cut off, then Yarkovsky may push icy particles outward, away from the inner edge of the A <span class="hlt">ring</span>, leaving only the rocky ones in the Division. The above scenarios depend delicately on the properties of the icy particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..92n4304N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..92n4304N"><span id="translatedtitle">Influence of pulse <span class="hlt">width</span> and detuning on coherent phonon generation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakamura, Kazutaka G.; Shikano, Yutaka; Kayanuma, Yosuke</p> <p>2015-10-01</p> <p>We investigated the coherent phonon generation mechanism by irradiation of an ultrashort pulse with a simple two-level model. Our derived formulation shows that both impulsive stimulated Raman scattering (ISRS) and impulsive absorption (IA) simultaneously occur, and phonon wave packets are generated in the electronic ground and excited states by ISRS and IA, respectively. We identify the dominant process from the amplitude of the phonon oscillation. For short pulse <span class="hlt">widths</span>, ISRS is very small and becomes larger as the pulse <span class="hlt">width</span> increases. We also show that the initial phase is dependent on the pulse <span class="hlt">width</span> and the detuning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011441','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011441"><span id="translatedtitle">Bank stability and channel <span class="hlt">width</span> adjustment, East Fork River, Wyoming.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Andrews, E.D.</p> <p>1982-01-01</p> <p>Frequent surveys of eight cross sections located in self-formed reaches of the East Fork River, Wyoming, during the 1974 snowmelt flood showed a close relation between channel morphology and scour and fill. Those cross sections narrower than the mean reach <span class="hlt">width</span> filled at discharges less than bankfull and scoured at discharges greater than bankfull. Those cross sections wider than the mean reach <span class="hlt">width</span> scoured at discharges less than bankfull and filled at discharges greater than bankfull. Bank stability, and to some extent the adjustment of stream channel <span class="hlt">width</span>, in the East Fork River study reach appears to be controlled by the processes of scour and fill. -from Author</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HEDP...18...14I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HEDP...18...14I"><span id="translatedtitle">Comparison of electron <span class="hlt">width</span> models for fast line profile calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iglesias, Carlos A.</p> <p>2016-03-01</p> <p>The first non-vanishing term in the perturbation expansion of the electron contribution to the line <span class="hlt">width</span>, commonly used in spectral line broadening by plasmas, was previously expressed in terms of the thermally averaged bremsstrahlung Gaunt factor. The approximations in the derivation, however, suggest that the result is uncertain. The electron <span class="hlt">width</span> formula is tested with the hydrogen Balmer series and found suspect. Calculations for the He II Lyman series also display similar difficulties. The limitation of this electron <span class="hlt">width</span> formulation is traced to the absence of an explicit strong collision cutoff beyond which the second-order theory is invalid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22370570','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22370570"><span id="translatedtitle">On the stability of pick-up ion <span class="hlt">ring</span> distributions in the outer heliosheath</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Summerlin, Errol J.; Viñas, Adolfo F.; Moore, Thomas E.; Christian, Eric R.; Cooper, John F. E-mail: adolfo.figueroa-vinas-1@nasa.gov E-mail: eric.r.christian@nasa.gov</p> <p>2014-10-01</p> <p>The 'secondary energetic neutral atom (ENA)' hypothesis for the ribbon feature observed by the Interstellar Boundary Explorer (IBEX) posits that the neutral component of the solar wind continues beyond the heliopause and charge exchanges with interstellar ions in the Outer Heliosheath (OHS). This creates pick-up ions that gyrate about the draped interstellar magnetic field (ISMF) lines at pitch angles near 90° on the locus where the ISMF lies tangential to the heliopause and perpendicular to the heliocentric radial direction. This location closely coincides with the location of the ribbon feature according to the prevailing inferences of the ISMF orientation and draping. The locally gyrating ions undergo additional charge exchange and escape as free-flying neutral atoms, many of which travel back toward the inner solar system and are imaged by IBEX as a ribbon tracing out the locus described above. For this mechanism to succeed, the pick-up ions must diffuse in pitch angle slowly enough to permit secondary charge exchange before their pitch angle distribution substantially broadens away from 90°. Previous work using linear Vlasov dispersion analysis of parallel propagating waves has suggested that the <span class="hlt">ring</span> distribution in the OHS is highly unstable, which, if true, would make the secondary ENA hypothesis incapable of rendering the observed ribbon. In this paper, we extend this earlier work to more realistic <span class="hlt">ring</span> distribution functions. We find that, at the low densities necessary to produce the observed IBEX ribbon via the secondary ENA hypothesis, <span class="hlt">growth</span> rates are highly sensitive to the temperature of the beam and that even very modest temperatures of the <span class="hlt">ring</span> beam corresponding to beam <span class="hlt">widths</span> of <1° are sufficient to damp the self-generated waves associated with the <span class="hlt">ring</span> beam. Thus, at least from the perspective of linear Vlasov dispersion analysis of parallel propagating waves, there is no reason to expect that the <span class="hlt">ring</span> distributions necessary to produce the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/238724','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/238724"><span id="translatedtitle">Gain narrowing of temporal and spectral <span class="hlt">widths</span> in the UVSOR-FEL</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kimura, K.; Yamazaki, J.; Kinoshita, T.</p> <p>1995-12-31</p> <p>Storage <span class="hlt">ring</span> free electron laser (SR-FEL) dynamics on the UVSOR-FEL in the visible region has been studied with measurements of the temporal and the spectral <span class="hlt">widths</span> of the laser micropulse. The micro- and the macro-temporal structures were measured using a dual sweep streak camera. We have also investigated spectral evolution of the laser with a Fabry-Perot etalon. Only a slow sweep function of the streak camera has been used for a fringe pattern formed by the air gap etalon to derive time-dependent variations of the spectral shape. We have measured the time-averaged pulsewidths and linewidths as a function of the <span class="hlt">ring</span> current. We observed that every macropulse contains internal substructures in both the temporal and the spectral distributions. The internal substructure, however, disappeared when the spectra of more than fifty macropulses were superimposed, and the envelope of the distribution became close to a Gaussian. We have found that the pulsewidth and the linewidth become narrower as the <span class="hlt">ring</span> current decays. In the gain-switching mode, the micropulse duration and the linewidth at the maximum <span class="hlt">ring</span> current were 80 ps(FWHM) and 0.3 nm(FWHM), respectively, and decreased down to 20 ps and 0.1 nm just above the threshold current. The temporal and the spectral <span class="hlt">widths</span> seem to follow the gain behavior. Assuming that the pulsewidth and the linewidth depend on the laser gain, the bandwidth in weakly saturated situation such as SR-FEL is determined by the gain narrowing of the laser amplifier. Because the gain evolution is able to be deduced from the macropulse shape, we can obtain the relation between the bandwidth and an effective gain above the mirror loss. The temporal and the spectral evolutions of the UVSOR-FEL were well explained by the gain narrowing related to a gain integrated from the oscillation build-up to the gain saturation. Detail of the experiment and the analysis will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006epsc.conf..196E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006epsc.conf..196E"><span id="translatedtitle">Planetary <span class="hlt">rings</span>: Structure and history</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Esposito, L.</p> <p></p> <p>The composition and structure of planetary <span class="hlt">rings</span> provide the key evidence to understand their origin and evolution. Before the first space observations, we were able to maintain an idealized view of the <span class="hlt">rings</span> around Saturn, the only known <span class="hlt">ring</span> system at that time. <span class="hlt">Rings</span> were then discovered around Jupiter, Uranus and Neptune. Saturn's F <span class="hlt">ring</span> was discovered by Pioneer 11. Our ideal view of circular, planar, symmetric and unchanging <span class="hlt">rings</span> was shattered by observations of inclined, eccentric <span class="hlt">rings</span>, waves and wavy edges, and numerous processes acting at rates that give timescales much younger than the solar system. Moons within and near the <span class="hlt">rings</span> sculpt them and are the likely progenitors of future <span class="hlt">rings</span>. The moonlet lifetimes are much less than Saturn's age. The old idea of ancient <span class="hlt">rings</span> gave rise to youthful <span class="hlt">rings</span>, that are recently created by erosion and destruction of small nearby moons. Although this explanation may work well for most <span class="hlt">rings</span>, Saturn's massive <span class="hlt">ring</span> system provides a problem. It is extremely improbable that Saturn's <span class="hlt">rings</span> were recently created by the destruction of a moon as large as Mimas, or even by the breakup of a large comet that passed too close to Saturn. The history of Saturn's <span class="hlt">rings</span> has been a difficult problem, now made even more challenging by the close-up Cassini measurements. Cassini observations show unexpected <span class="hlt">ring</span> variability in time and space. Time variations are seen in <span class="hlt">ring</span> edges, in the thinner D and F <span class="hlt">rings</span>, and in the neutral oxygen cloud, which outweighs the E <span class="hlt">ring</span> in the same region around Saturn. The <span class="hlt">rings</span> are inhomogeneous, with structures on all scales, sharp gradients and edges. Compositional gradients are sharper than expected, but nonetheless cross structural boundaries. This is evidence for ballistic transport that has not gone to completion. The autocovariance maximizes in the middle of the A <span class="hlt">ring</span>, with smaller structure near the main <span class="hlt">rings</span>' outer edge. Density wave locations have a fresher ice composition. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760000146&hterms=compact+disc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528compact%2Bdisc%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760000146&hterms=compact+disc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528compact%2Bdisc%2529"><span id="translatedtitle">Connector contact-<span class="hlt">ring</span> bus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ligon, J.</p> <p>1976-01-01</p> <p>Use of device eliminates crimp connectors and ferrules, resulting in compact termination assembly and efficient use of back-shell space. Pair of insulator <span class="hlt">rings</span>, one at each end of assembly, provides spacing between disc caps and contact <span class="hlt">rings</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000312','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000312"><span id="translatedtitle">Inorganic glass ceramic slip <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Glossbrenner, E. W.; Cole, S. R.</p> <p>1972-01-01</p> <p>Prototypes of slip <span class="hlt">rings</span> have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip <span class="hlt">ring</span> assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ERL.....6d1004P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ERL.....6d1004P"><span id="translatedtitle">Who is the new sheriff in town regulating boreal forest <span class="hlt">growth</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park Williams, A.; Xu, Chonggang; McDowell, Nate G.</p> <p>2011-12-01</p> <p>Climate change appears to be altering boreal forests. One recently observed symptom of these changes has been an apparent weakening of the positive relationship between high-latitude boreal tree <span class="hlt">growth</span> and temperature at some sites (D'Arrigo et al 2008). This phenomenon is referred to as the 'divergence problem' or 'divergence effect' and is thought to reflect a non-linear relationship between temperature and tree <span class="hlt">growth</span>, where recent warming has allowed other factors besides growing-season temperature to emerge as dominant regulators of annual <span class="hlt">growth</span> rates. Figure 1 demonstrates this divergence phenomenon with records of tree-<span class="hlt">ring</span> <span class="hlt">widths</span> collected from 59 populations of white spruce in Alaska 1. Key tendencies among these populations include: (1) <span class="hlt">growth</span> is most sensitive to temperature during relatively cold growing seasons (figure 1(a)), (2) populations at colder sites are more sensitive to temperature than those at warmer sites are (figure 1(a)), and (3) <span class="hlt">growth</span> at warmer sites may respond negatively to increased temperature beyond some optimal growing-season temperature (figure 1(b)). Since temperature is rising rapidly at high latitudes, one interpretation of figures 1(a) and (b) is that warming has promoted increased <span class="hlt">growth</span> at colder sites, but caused <span class="hlt">growth</span> to plateau or slow at warmer sites. Corroborating this interpretation, satellite imagery and tree-<span class="hlt">ring</span> data indicate increasing vegetation productivity near the forest-tundra boundary but declining productivity in warmer regions within forest interiors (e.g., Bunn and Goetz 2006, Beck and Goetz 2011, Beck et al 2011, Berner et al 2011). Will continued warming cause a northward migration of boreal forests, with mortality in the warmer, southern locations and expansion into the colder tundra? This question is difficult to answer because many factors besides temperature influence boreal forest dynamics. Widespread productivity declines within interior boreal forests appear to be related to warming</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70129567','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70129567"><span id="translatedtitle">Climatic influences on the <span class="hlt">growth</span> of subalpine trees in the Colorado Front Range</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Villalba, Ricardo; Veblen, Thomas T.; Ogden, John</p> <p>1994-01-01</p> <p>We examined variations in tree <span class="hlt">growth</span> responses to climatic variations among different tree species and habitat types in the subalpine zone of the Colorado Front Range. We constructed 25 tree <span class="hlt">ring</span> site chronologies (11 of Picea engelmannii, 9 of Abies lasiocarpa, 4 of Pinus contorta var. latifolia, and 1 of Pinus flexilis) from a series of subalpine habitats ranging from xeric to wet. To establish tree <span class="hlt">growth</span> responses to climatic variation, we used correlation and response function analyses to compare variations in <span class="hlt">ring</span> <span class="hlt">widths</span> with monthly temperature and precipitation records. At the driest sites, <span class="hlt">growth</span> of Picea and Abies tracked climatic variation similarly. At mesic and wet sites, however, these species differed in their responses to climatic variation. The responses of Pinus contorta, sampled over a narrower range of habitat types, differed from those of Picea and Abies but did not differ among sites. Steep environmental gradients in the subalpine zone of the Front Range accounted for most of the observed differences in <span class="hlt">growth</span> responses to climatic variation. Even at adjacent sites that differ only slightly in topographic position, tree <span class="hlt">growth</span> responses to climatic variation were distinct. Interspecific differences in response to climatic variations generally were less important than site differences. Intersite differences in tree <span class="hlt">growth</span> responses to climatic variation can be used as indicators of environmental differences among subalpine habitats.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7025821','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7025821"><span id="translatedtitle">Climatic influences on the <span class="hlt">growth</span> of subalpine trees in the Colorado front range</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Villalba, R.; Veblen, T.T. ); Ogden, J. )</p> <p>1994-07-01</p> <p>We examined variations in tree <span class="hlt">growth</span> responses to climatic variations among different tree species and habitat types in the subalpine zone of the Colorado Front Range. We constructed 25 tree <span class="hlt">ring</span> site chronologies (11 of Picea engelmannii, 9 of Abies lasiocarpa, 4 of Pinus contorta var. latifolia, and 1 of Pinusflexilis) from a series of subalpine habitats ranging from xeric to wet. To establish tree <span class="hlt">growth</span> responses to climatic variation, we used correlation and response function analyses to compare variations in <span class="hlt">ring</span> <span class="hlt">widths</span> with monthly temperature and precipitation records. At the driest sites, <span class="hlt">growth</span> of Picea and Abies tracked climatic variation similarly. At mesic and wet sites, however, these species differed in their responses to climatic variation. The responses of Pinus contorta, sampled over a narrower range of habitat types, differed from those of Picea and Abies but did not differ among sites. Steep environmental gradients in the subalpine zone of the Front Range accounted for most of the observed differences in <span class="hlt">growth</span> responses to climatic variation. Even at adjacent sites that differ only slightly in topographic position, tree <span class="hlt">growth</span> responses to climatic variation were distinct. Interspecific differences in response to climatic variations generally were less important than site differences. Intersite differences in tree <span class="hlt">growth</span> responses to climatic variation can be used as indicators of environmental differences among subalpine habitats. 39 refs., 9 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ERL....11g4021H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ERL....11g4021H&link_type=ABSTRACT"><span id="translatedtitle">Diverse <span class="hlt">growth</span> trends and climate responses across Eurasia’s boreal forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hellmann, Lena; Agafonov, Leonid; Charpentier Ljungqvist, Fredrik; Churakova (Sidorova, Olga; Düthorn, Elisabeth; Esper, Jan; Hülsmann, Lisa; Kirdyanov, Alexander V.; Moiseev, Pavel; Myglan, Vladimir S.; Nikolaev, Anatoly N.; Reinig, Frederick; Schweingruber, Fritz H.; Solomina, Olga; Tegel, Willy; Büntgen, Ulf</p> <p>2016-07-01</p> <p>The area covered by boreal forests accounts for ∼16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not only have strong effects on species composition and diversity at regional to larger scales, but also on the Earth’s carbon cycle. Although temporal inconsistency in the response of tree <span class="hlt">growth</span> to temperature has been reported from some locations at the higher northern latitudes, a systematic dendroecological network assessment is still missing for most of the boreal zone. Here, we analyze the geographical patterns of changes in summer temperature and precipitation across northern Eurasia >60 °N since 1951 AD, as well as the <span class="hlt">growth</span> trends and climate responses of 445 Pinus, Larix and Picea <span class="hlt">ring</span> <span class="hlt">width</span> chronologies in the same area and period. In contrast to widespread summer warming, fluctuations in precipitation and tree <span class="hlt">growth</span> are spatially more diverse and overall less distinct. Although the influence of summer temperature on <span class="hlt">ring</span> formation is increasing with latitude and distinct moisture effects are restricted to a few southern locations, <span class="hlt">growth</span> sensitivity to June–July temperature variability is only significant at 16.6% of all sites (p ≤ 0.01). By revealing complex climate constraints on the productivity of Eurasia’s northern forests, our results question the a priori suitability of boreal tree-<span class="hlt">ring</span> <span class="hlt">width</span> chronologies for reconstructing summer temperatures. This study further emphasizes regional climate differences and their role on the dynamics of boreal ecosystems, and also underlines the importance of free data access to facilitate the compilation and evaluation of massively replicated and updated dendroecological networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5549443','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5549443"><span id="translatedtitle">A <span class="hlt">ring</span> galaxy in Canes Venatici and related <span class="hlt">ring</span> galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wakamatsu, Ken-ichi; Nishida, M.T. Kobe Women's University )</p> <p>1991-04-01</p> <p>A spectroscopic observation was made of a <span class="hlt">ring</span>-shaped object in Canes Venatici. A bright knot at the edge of the <span class="hlt">ring</span> has a recession velocity of 10,960 + or - 30 km/s and so is confirmed as an extragalactic object. It shows no sign of nuclear activity but appears to be an H II region of intermediate excitation class. The linear diameter of the <span class="hlt">ring</span> is 14.2 + or - 0.8 kpc, a typical size for <span class="hlt">ring</span> galaxies. Recession velocities of several other <span class="hlt">ring</span> galaxies are also given. 24 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27083524','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27083524"><span id="translatedtitle">Effects of mistletoe removal on <span class="hlt">growth</span>, N and C reserves, and carbon and oxygen isotope composition in Scots pine hosts.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Cai-Feng; Gessler, Arthur; Rigling, Andreas; Dobbertin, Matthias; Han, Xing-Guo; Li, Mai-He</p> <p>2016-05-01</p> <p>Most mistletoes are xylem-tapping hemiparasites, which derive their resources from the host's xylem solution. Thus, they affect the host's water relations and resource balance. To understand the physiological mechanisms underlying the mistletoe-host relationship, we experimentally removed Viscum album ssp. austriacum (Wiesb.) Vollmann from adult Pinus sylvestris L. host trees growing in a Swiss dry valley. We analyzed the effects of mistletoe removal over time on host tree <span class="hlt">growth</span> and on concentrations of nonstructural carbohydrates (NSC) and nitrogen (N) in needles, fine roots and sapwood. In addition, we assessed the δ(13)C and δ(18)O in host tree <span class="hlt">rings</span>. After mistletoe removal, δ(13)C did not change in newly produced tree <span class="hlt">rings</span> compared with tree <span class="hlt">rings</span> in control trees (still infected with mistletoe), but δ(18)O values increased. This pattern might be interpreted as a decrease in assimilation (A) and stomatal conductance (gs), but in our study, it most likely points to an inadequacy of the dual isotope approach. Instead, we interpret the unchanged δ(13)C in tree <span class="hlt">rings</span> upon mistletoe removal as a balanced increase in A and gs that resulted in a constant intrinsic water use efficiency (defined as A/gs). Needle area-based concentrations of N, soluble sugars and NSC, as well as needle length, single needle area, tree <span class="hlt">ring</span> <span class="hlt">width</span> and shoot <span class="hlt">growth</span>, were significantly higher in trees from which mistletoe was removed than in control trees. This finding suggests that mistletoe removal results in increased N availability and carbon gain, which in turn leads to increased <span class="hlt">growth</span> rates of the hosts. Hence, in areas where mistletoe is common and the population is large, mistletoe management (e.g., removal) may be needed to improve the host vigor, <span class="hlt">growth</span> rate and productivity, especially for relatively small trees and crop trees in xeric <span class="hlt">growth</span> conditions. PMID:27083524</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/va1677.photos.368620p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/va1677.photos.368620p/"><span id="translatedtitle">223. FREQUENTLY REPRODUCED VIEW OF GWMP SHOWING VARIABLE <span class="hlt">WIDTH</span> MEDIANS ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>223. FREQUENTLY REPRODUCED VIEW OF GWMP SHOWING VARIABLE <span class="hlt">WIDTH</span> MEDIANS WITH INDEPENDENT ALIGNMENTS FROM KEY BRIDGE LOOKING NORTHWEST, 1953. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1018320','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1018320"><span id="translatedtitle">Optical waveguide device with an adiabatically-varying <span class="hlt">width</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Watts; Michael R. , Nielson; Gregory N.</p> <p>2011-05-10</p> <p>Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a <span class="hlt">width</span> that varies adiabatically between a minimum value and a maximum value of the <span class="hlt">width</span>. One or more connecting members can be attached to the waveguide bend near the maximum value of the <span class="hlt">width</span> thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the <span class="hlt">width</span>. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5874..266G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5874..266G"><span id="translatedtitle">Better Polynomial Algorithms on Graphs of Bounded Rank-<span class="hlt">Width</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ganian, Robert; Hliněný, Petr</p> <p></p> <p>Although there exist many polynomial algorithms for NP-hard problems running on a bounded clique-<span class="hlt">width</span> expression of the input graph, there exists only little comparable work on such algorithms for rank-<span class="hlt">width</span>. We believe that one reason for this is the somewhat obscure and hard-to-grasp nature of rank-decompositions. Nevertheless, strong arguments for using the rank-<span class="hlt">width</span> parameter have been given by recent formalisms independently developed by Courcelle and Kanté, by the authors, and by Bui-Xuan et al. This article focuses on designing formally clean and understandable "pseudopolynomial" (XP) algorithms solving "hard" problems (non-FPT) on graphs of bounded rank-<span class="hlt">width</span>. Those include computing the chromatic number and polynomial or testing the Hamiltonicity of a graph and are extendable to many other problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17842136','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17842136"><span id="translatedtitle">Uranus: the <span class="hlt">rings</span> are black.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sinton, W M</p> <p>1977-11-01</p> <p>An upper limit of 0.05 is established for the geometric albedo of the newly discovered <span class="hlt">rings</span> of Uranus. In view of this very low albedo, the particles of the <span class="hlt">rings</span> cannot be ice-covered as are those of <span class="hlt">rings</span> A and B of Saturn. PMID:17842136</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880039814&hterms=net+force&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dnet%2Bforce','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880039814&hterms=net+force&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dnet%2Bforce"><span id="translatedtitle">Electrostatic forces in planetary <span class="hlt">rings</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goertz, C. K.; Shan, Linhua; Havnes, O.</p> <p>1988-01-01</p> <p>The average charge on a particle in a particle-plasma cloud, the plasma potential inside the cloud, and the Coulomb force acting on the particle are calculated. The net repulsive electrostatic force on a particle depends on the plasma density, temperature, density of particles, particle size, and the gradient of the particle density. In a uniformly dense <span class="hlt">ring</span> the electrostatic repulsion is zero. It is also shown that the electrostatic force acts like a pressure force, that even a collisionless <span class="hlt">ring</span> can be stable against gravitational collapse, and that a finite <span class="hlt">ring</span> thickness does not necessarily imply a finite velocity dispersion. A simple criterion for the importance of electrostatic forces in planetary <span class="hlt">rings</span> is derived which involves the calculation of the vertical <span class="hlt">ring</span> thickness which would result if only electrostatic repulsion were responsible for the finite <span class="hlt">ring</span> thickness. Electrostatic forces are entirely negligible in the main <span class="hlt">rings</span> of Saturn and the E and G <span class="hlt">rings</span>. They may also be negligible in the F <span class="hlt">ring</span>. However, the Uranian <span class="hlt">rings</span> and Jupiter's <span class="hlt">ring</span> seem to be very much influenced by electrostatic repulsion. In fact, electrostatic forces could support a Jovian <span class="hlt">ring</span> which is an order of magnitude more dense than observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=force+AND+motion&pg=5&id=EJ1090098','ERIC'); return false;" href="http://eric.ed.gov/?q=force+AND+motion&pg=5&id=EJ1090098"><span id="translatedtitle">DC-Powered Jumping <span class="hlt">Ring</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jeffery, Rondo N.; Farhang, Amiri</p> <p>2016-01-01</p> <p>The classroom jumping <span class="hlt">ring</span> demonstration is nearly always performed using alternating current (AC), in which the <span class="hlt">ring</span> jumps or flies off the extended iron core when the switch is closed. The <span class="hlt">ring</span> jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJS..221...25P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJS..221...25P"><span id="translatedtitle"><span class="hlt">Ringed</span> Accretion Disks: Equilibrium Configurations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pugliese, D.; Stuchlík, Z.</p> <p>2015-12-01</p> <p>We investigate a model of a <span class="hlt">ringed</span> accretion disk, made up by several <span class="hlt">rings</span> rotating around a supermassive Kerr black hole attractor. Each toroid of the <span class="hlt">ringed</span> disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The <span class="hlt">ringed</span> disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating <span class="hlt">rings</span> have to be considered as being a constituent of the <span class="hlt">ringed</span> disk. We provide constraints on the model parameters for the existence and stability of various <span class="hlt">ringed</span> configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the <span class="hlt">ringed</span> disk. We demonstrate that various <span class="hlt">ringed</span> disks can be characterized by a maximum number of <span class="hlt">rings</span>. We present also a perturbation analysis based on evolution of the oscillating components of the <span class="hlt">ringed</span> disk. The dynamics of the unstable phases of the <span class="hlt">ringed</span> disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ShWav..25...35M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ShWav..25...35M"><span id="translatedtitle">Testing an analytic model for Richtmyer-Meshkov turbulent mixing <span class="hlt">widths</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mikaelian, K. O.</p> <p>2015-01-01</p> <p>We discuss a model for the evolution of the turbulent mixing <span class="hlt">width</span> after a shock or a reshock passes through the interface between two fluids of densities and inducing a velocity jump . In this model, the initial <span class="hlt">growth</span> rate is independent of the surface finish or initial mixing <span class="hlt">width</span> , but its duration is directly proportional to it: for , and for . Here is the Atwood number and are dimensionless, -dependent parameters measured in past Rayleigh-Taylor experiments, and is a new dimensionless parameter we introduce via . The mixing <span class="hlt">width</span> and its derivative remain continuous at since and . We evaluate at from air/SF experiments and propose that the transition at signals isotropication of turbulence. We apply this model to the recent experiments of Jacobs et al. (Shock Waves 23:407-413, 2013) on shock and reshock, and discuss briefly the third wave causing an unstable acceleration of the interface. We also consider the experiments of Weber et al. (Phys Fluids 24:074105, 2012) and argue that their smaller <span class="hlt">growth</span> rates reflect density gradient stabilization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27078636','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27078636"><span id="translatedtitle">Facial <span class="hlt">Width</span>-To-Height Ratio (fWHR) Is Not Associated with Adolescent Testosterone Levels.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hodges-Simeon, Carolyn R; Hanson Sobraske, Katherine N; Samore, Theodore; Gurven, Michael; Gaulin, Steven J C</p> <p>2016-01-01</p> <p>Facial <span class="hlt">width</span>-to-height ratio (fWHR) has been proposed as a sexually dimorphic signal in humans that develops under the influence of pubertal testosterone (T); however, no studies have examined the association between fWHR and T during the phase in which facial <span class="hlt">growth</span> is canalized-adolescence. In a sample of adolescent Tsimane males, we evaluate the relationship between T, known T-derived traits (i.e. strength and voice pitch), and craniofacial measurements. If fWHR variation derives from T's effect on craniofacial <span class="hlt">growth</span> during adolescence, several predictions should be supported: 1) fWHR should increase with age as T increases, 2) fWHR should reflect adolescent T (rather than adult T per se), 3) fWHR should exhibit velocity changes during adolescence in parallel with the pubertal spurt in T, 4) fWHR should correlate with T after controlling for age and other potential confounds, and 5) fWHR should show strong associations with other T-derived traits. Only prediction 4 was observed. Additionally, we examined three alternative facial masculinity ratios: facial <span class="hlt">width</span>/lower face height, cheekbone prominence, and facial <span class="hlt">width</span>/full face height. In contrast to fWHR, all three alternative measures show a strong age-related trend and are associated with both T and T-dependent traits. Overall, our results question the status of fWHR as a sexually-selected signal of pubertal T and T-linked traits. PMID:27078636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MARJ22003Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MARJ22003Y&link_type=ABSTRACT"><span id="translatedtitle">Narrow optical line <span class="hlt">width</span> from site-controlled InGaAs quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Lily; Yakes, Michael; Sweeney, Timothy; Carter, Samuel; Kim, Chulsoo; Kim, Mijin; Bracker, Allan; Gammon, Daniel</p> <p>2013-03-01</p> <p>The incorporation of self-assembled quantum dots (QDs) in systematically scalable quantum devices requires a method of nucleating dots with nanometer-scale spatial accuracy while preserving their narrow optical line <span class="hlt">width</span>. We have developed a technique combining e-beam lithography, wet etching, and molecular beam epitaxial (MBE) <span class="hlt">growth</span> to deterministically position InGaAs QDs with spectrometer limited photoluminescence line <span class="hlt">widths</span>. Our technique takes advantage of the anisotropy in GaAs <span class="hlt">growth</span> to evolve an etched pattern of holes and lines into faceted structures in which dots nucleate. Using this technique, we were able to grow a buffer layer of pure GaAs up to 90 nm in thickness between the processed surface and the dot nucleation surface, effectively separating the QDs from unavoidable residual defects and impurities on the patterned surface that broaden their optical line <span class="hlt">widths</span>. Additionally, we demonstrate control over the number of dots nucleating per site, from single to a chain of several, by varying the dimensions of the original pattern. Our dots are grown in a Schottky diode structure. Their PL spectrum shows discrete charging transitions, with narrow linewidths near the spectrometer's resolution limit of 20 micro eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55dEM04T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55dEM04T"><span id="translatedtitle">Differential Si <span class="hlt">ring</span> resonators for label-free biosensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taniguchi, Tomoya; Yokoyama, Shuhei; Amemiya, Yoshiteru; Ikeda, Takeshi; Kuroda, Akio; Yokoyama, Shin</p> <p>2016-04-01</p> <p>Differential Si <span class="hlt">ring</span> optical resonator sensors have been fabricated. Their detection sensitivity was 10-3-10-2% for sucrose solution, which corresponds to a sensitivity of ˜1.0 ng/ml for prostate-specific antigen (PSA), which is satisfactory for practical use. In the differential sensing the input light is incident to two <span class="hlt">rings</span>, and one of the outputs is connected to a π phase shifter then the two outputs are merged again. For the differential detection, not only is the common-mode noise canceled, resulting in high sensitivity, but also the temperature stability is much improved. A fluid channel is fabricated so that the detecting liquid flows to the detection <span class="hlt">ring</span> and the reference liquid flows to the reference <span class="hlt">ring</span>. We have proposed a method of obtaining a constant sensitivity for the integrated sensors even though the resonance wavelengths of the two <span class="hlt">rings</span> of the differential sensor are slightly different. It was found that a region exists with a linear relationship between the differential output and the difference in the resonance wavelengths of the two <span class="hlt">rings</span>. By intentionally differentiating the resonance wavelengths in this linear region, the sensors have a constant sensitivity. Many differential sensors with different <span class="hlt">ring</span> spaces have been fabricated and the output scattering characteristics were statistically evaluated. As a result, a standard deviation of resonance wavelength σ = 8 × 10-3 nm was obtained for a <span class="hlt">ring</span> space of 31 µm. From the <span class="hlt">width</span> of the linear region and the standard deviation, it was estimated from the Gaussian distribution of the resonance wavelength that 93.8% of the devices have the same sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010041281&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010041281&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Saturn <span class="hlt">Ring</span> Observer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spilker, T. R.</p> <p>2001-01-01</p> <p>Answering fundamental questions about <span class="hlt">ring</span> particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a <span class="hlt">ring</span> system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02872&hterms=movies&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmovies','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02872&hterms=movies&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmovies"><span id="translatedtitle">Satellite <span class="hlt">Rings</span> Movie</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p><p/>This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's <span class="hlt">ring</span>. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.<p/>The movie was made from images taken during a 40-hour sequence of the Jovian <span class="hlt">ring</span> on December 11, 2000.<p/>Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.H52C..07A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.H52C..07A&link_type=ABSTRACT"><span id="translatedtitle">Patterns of river <span class="hlt">width</span> and surface area newly revealed by the satellite-derived North American River <span class="hlt">Width</span> (NARWidth) dataset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allen, G. H.; Pavelsky, T.</p> <p>2014-12-01</p> <p>The total surface area of rivers and streams is a key quantity for estimating gaseous emissions from fluvial networks to the atmosphere. Presently, the most sophisticated evaluations of continental-scale river surface area rely on: 1) calculating river <span class="hlt">width</span> from digital elevation models (DEMs) by scaling <span class="hlt">width</span> to upstream drainage area via downstream hydraulic geometry (DHG) relationships; 2) extrapolating river <span class="hlt">width</span> and length from large to small river basins using Horton ratios; and 3) extrapolating empirical relationships between climate and percentage water cover to from low- to high-latitude basins where hydrologically conditioned topographic data does not exist. Here we use the recently developed North American River <span class="hlt">Width</span> (NARWidth) dataset to estimate the total surface area of North American rivers and streams. NARWidth is the first fine-resolution, continental-scale river centerline and <span class="hlt">width</span> database. The database is derived from Landsat satellite imagery and contains measurements of >2.4×105 km of rivers wider than 30 m at mean annual discharge. We find that datasets that estimate river <span class="hlt">width</span> by applying DHG relationships to DEMs underestimate the abundance of wide rivers and do not capture the widest rivers observed by NARWidth. We attribute these differences to: 1) the tendency of stream gauges to be located at stable, single channel sites, leading to a potential bias of measured river <span class="hlt">width</span> relative to the representative river <span class="hlt">width</span> throughout a river's entire length; and 2) physiographic conditions that are not captured by DHG and can cause substantial deviation from strict <span class="hlt">width</span>-discharge relationships. We then calculate the total surface area of North American rivers by extrapolating the strong observed relationship between total river surface area and <span class="hlt">width</span> at different <span class="hlt">widths</span> (r2>0.996 for 100-2000 m <span class="hlt">widths</span>) to narrow rivers and streams. We find that the total surface area of North American rivers is ~1.38×105 km2 for all rivers wider than 1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20632664','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20632664"><span id="translatedtitle">Finite coplanar waveguide <span class="hlt">width</span> effects in pulsed inductive microwave magnetometry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schneider, M.L.; Kos, A.B.; Silva, T.J.</p> <p>2004-07-12</p> <p>The effect of finite coplanar waveguide (CPW) <span class="hlt">width</span> on the measurement of the resonance frequency in thin ferromagnetic films has been characterized for pulsed inductive microwave magnetometry. A shift in resonant frequency is a linear function of the ratio of sample thickness to CPW <span class="hlt">width</span>. The proportionality constant is experimentally determined to be 0.74{+-}0.1 times the saturation magnetization of the film. The frequency shift may be modeled as arising from an effective magnetic-anisotropy field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H31F1242A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H31F1242A"><span id="translatedtitle">Quantifying River <span class="hlt">Widths</span> of North America from Satellite Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allen, G. H.; Pavelsky, T.; Miller, Z.</p> <p>2013-12-01</p> <p>River <span class="hlt">width</span> is a fundamental predictor variable in many hydrologic, geomorphic, and biogeochemical models, yet current large-scale models rely on theoretical hydraulic geometry relationships that do not fully capture natural variability in river form. Here we present the first high-resolution dataset of long-term mean <span class="hlt">width</span> of North American rivers wider than 30 m. The dataset contains 7.93 million georeferenced <span class="hlt">width</span> measurements derived from Landsat TM and ETM+ imagery that were acquired when rivers were most likely to be at mean discharge. We built the dataset by developing an automated procedure that selects and downloads raw imagery, creates cloud-free normalized difference water index images, histogram balances and mosaics them together, and produces a water mask using a dynamic water-land threshold technique. We then visually inspected and corrected the mask for errors and used Riv<span class="hlt">Width</span> software to calculate river <span class="hlt">width</span> at each river centerline pixel. We validated our dataset using >1000 United States Geological Survey and Water Survey of Canada in situ gauge station measurements. Error analysis shows a robust relationship between the remotely sensed <span class="hlt">widths</span> and in situ gauge measurements with an r 2 = 0.86 (Spearman's = 0.81) and a mean absolute error of 27.5 m. We find that North American river <span class="hlt">widths</span> lie on logarithmic frequency curve with some notable exceptions at <span class="hlt">widths</span> <100 m. This dataset can be used to improve our understanding of the water, carbon, and nitrogen cycles, as well as large-scale landscape evolution models. Our results also allow for the characterization of the extent of rivers likely to be observable by the planned Surface Water and Ocean Topography (SWOT) satellite mission.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhRvB..5114686M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhRvB..5114686M"><span id="translatedtitle"><span class="hlt">Width</span> of the plasmon resonance in metal clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montag, B.; Reinhard, P.-G.</p> <p>1995-05-01</p> <p>The <span class="hlt">width</span> of the plasmon resonance in the clusters Na+9, Na+21, and Na+41 is investigated in the framework of the structure-averaged jellium model and compared with recent experimental data. The two leading mechanisms for the line broadening are fragmentation of the resonance into nearby 1ph states and splitting through thermal quadrupole fluctuations. The fragmentation becomes activated mainly through octupole fluctuations and it gives the dominating contribution to the <span class="hlt">width</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27554408','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27554408"><span id="translatedtitle">Oligomeric ferrocene <span class="hlt">rings</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Inkpen, Michael S; Scheerer, Stefan; Linseis, Michael; White, Andrew J P; Winter, Rainer F; Albrecht, Tim; Long, Nicholas J</p> <p>2016-09-01</p> <p>Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category-differently sized <span class="hlt">rings</span> comprising only 1,1'-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e(-) waves. Theoretical interrogations into correlations based on <span class="hlt">ring</span> size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall <span class="hlt">ring</span> charge and in conjunction with fast intramolecular electron transfer (∼10(7) s(-1)), these molecules can be considered as uniformly charged nanorings (diameter ∼1-2 nm). PMID:27554408</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996APS..MAR.R1814B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996APS..MAR.R1814B"><span id="translatedtitle">Swarming <span class="hlt">rings</span> of bacteria.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brenner, M. P.; Levitov, L. S.</p> <p>1996-03-01</p> <p>The behavior of bacterii controlled by chemotaxis can lead to a complicated spatial organization, producing swarming <span class="hlt">rings</span>, and steady or moving aggregates( E. O. Budrene, and H. C. Berg, Complex patterns formed by motile cells of Escherichia coli. Nature 349, 630-633 (1991). ). We present a simple theory that explains the experimentally observed structures, by solving analytically two coupled differential equations, for the densities of bacterii and of chemoattractant. The equations have an interesting relation to the exactly solvable Burgers equation, and admit soliton-like solutions, that can be steady or moving. In addition, we find that there are singular solutions to the equations in which the bacterial density diverges. The theory agrees very well with the experiment: the solitons correspond to the observed travelling <span class="hlt">rings</span>, the singularities describe formation of aggregates. In particular, the theory explains why the velocity of swarming <span class="hlt">rings</span> decreases with the increase of the food concentration, the fact apparently not accounted by other existing approaches( L. Tsimring et. al., Phys. Rev. Lett., 75, 1859 (1995); Woodward, et al, Biophysical Journal, 68, 2181-2189 (1995). ).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AJ....146..158P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AJ....146..158P"><span id="translatedtitle">H I Lyman-alpha Equivalent <span class="hlt">Widths</span> of Stellar Populations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peña-Guerrero, María A.; Leitherer, Claus</p> <p>2013-12-01</p> <p>We have compiled a library of stellar Lyman-alpha (Lyα) equivalent <span class="hlt">widths</span> in O and B stars using the model atmosphere codes CMFGEN and TLUSTY, respectively. The equivalent <span class="hlt">widths</span> range from about 0 to 30 Å in absorption for early-O to mid-B stars. The purpose of this library is for the prediction of the underlying stellar Lyα absorption in stellar populations of star-forming galaxies with nebular Lyα emission. We implemented the grid of individual equivalent <span class="hlt">widths</span> into the Starburst99 population synthesis code to generate synthetic Lyα equivalent <span class="hlt">widths</span> for representative star formation histories. A starburst observed after 10 Myr will produce a stellar Lyα line with an equivalent <span class="hlt">width</span> of ~ - 10 ± 4 Å in absorption for a Salpeter initial mass function. The lower value (deeper absorption) results from an instantaneous burst, and the higher value (shallower line) from continuous star formation. Depending on the escape fraction of nebular Lyα photons, the effect of stellar Lyα on the total profile ranges from negligible to dominant. If the nebular escape fraction is 10%, the stellar absorption and nebular emission equivalent <span class="hlt">widths</span> become comparable for continuous star formation at ages of 10-20 Myr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SMaS...23d5031Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SMaS...23d5031Z"><span id="translatedtitle">Crack <span class="hlt">width</span> monitoring of concrete structures based on smart film</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhang, Xu; Yang, Guang; Qiu, Minfeng</p> <p>2014-04-01</p> <p>Due to its direct link to structural security, crack <span class="hlt">width</span> is thought to be one of the most important parameters reflecting damage conditions of concrete structures. However, the <span class="hlt">width</span> problem is difficult to solve with the existing structural health monitoring methods. In this paper, crack <span class="hlt">width</span> monitoring by means of adhering enameled copper wires with different ultimate strains on the surface of structures is proposed, based on smart film crack monitoring put forward by the present authors. The basic idea of the proposed method is related to a proportional relationship between the crack <span class="hlt">width</span> and ultimate strain of the broken wire. Namely, when a certain <span class="hlt">width</span> of crack passes through the wire, some low ultimate strain wires will be broken and higher ultimate strain wires may stay non-broken until the crack extends to a larger scale. Detection of the copper wire condition as broken or non-broken may indicate the <span class="hlt">width</span> of the structural crack. Thereafter, a multi-layered stress transfer model and specimen experiment are performed to quantify the relationship. A practical smart film is then redesigned with this idea and applied to Chongqing Jiangjin Yangtze River Bridge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/1643059','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/1643059"><span id="translatedtitle"><span class="hlt">Growth</span> patterns in the orbital region: a morphometric study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farkas, L G; Posnick, J C; Hreczko, T M; Pron, G E</p> <p>1992-07-01</p> <p>Data for analysis of age-related changes in <span class="hlt">growth</span> in the intercanthal (en-en) and biocular (ex-ex) <span class="hlt">widths</span> were obtained from 1,594 healthy North American Caucasians in age groups from 1 to 18 years, divided equally between males and females. At 1 year, the degree of development of the intercanthal <span class="hlt">width</span> reached 84.1%, and that of the biocular <span class="hlt">width</span> 85.9% of adults in both sexes. The levels of <span class="hlt">growth</span> achieved by 5 years of age rose to 93.3% in the intercanthal <span class="hlt">width</span> and 88.1% in the biocular <span class="hlt">width</span>, in both sexes. The average total <span class="hlt">growth</span> increments achieved between ages 1 and 18 years were 5.2 mm in the intercanthal <span class="hlt">width</span> and 12.5 mm in the biocular. The intercanthal <span class="hlt">width</span> showed very little <span class="hlt">growth</span> after 1 year of age; in contrast, the biocular <span class="hlt">width</span> showed significantly greater <span class="hlt">growth</span> increments both before and after 5 years of age. Rapid <span class="hlt">growth</span> was observed between 3 and 4 years in the intercanthal <span class="hlt">width</span> of both sexes. The age-related <span class="hlt">growth</span> observed in the biocular <span class="hlt">width</span> was small but continuous up to maturation time. The intercanthal <span class="hlt">width</span> reached full maturation at 8 years in females and 11 years in males, and the biocular <span class="hlt">width</span> at 13 years in females and 15 years in males. PMID:1643059</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816471S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816471S"><span id="translatedtitle">The suitability of the dual isotope approach (δ13C and δ18O) in tree <span class="hlt">ring</span> studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siegwolf, Rolf; Saurer, Matthias</p> <p>2016-04-01</p> <p>The use of stable isotopes, complementary to tree <span class="hlt">ring</span> <span class="hlt">width</span> data in tree <span class="hlt">ring</span> research has proven to be a powerful tool in studying the impact of environmental parameters on tree physiology and <span class="hlt">growth</span>. These three proxies are thus instrumental for climate reconstruction and improve the understanding of underlying causes of <span class="hlt">growth</span> changes. In various cases, however, their use suggests non-plausible interpretations. Often the use of one isotope alone does not allow the detection of such "erroneous isotope responses". A careful analysis of these deviating results shows that either the validity of the carbon isotope discrimination concept is no longer true (Farquhar et al. 1982) or the assumptions for the leaf water enrichment model (Cernusak et al., 2003) are violated and thus both fractionation models are not applicable. In this presentation we discuss such cases when the known fractionation concepts fail and do not allow a correct interpretation of the isotope data. With the help of the dual isotope approach (Scheidegger et al.; 2000) it is demonstrated, how to detect and uncover the causes for such anomalous isotope data. The fractionation concepts and their combinations before the background of CO2 and H2O gas exchange are briefly explained and the specific use of the dual isotope approach for tree <span class="hlt">ring</span> data analyses and interpretations are demonstrated. References: Cernusak, L. A., Arthur, D. J., Pate, J. S. and Farquhar, G. D.: Water relations link carbon and oxygen isotope discrimination to phloem sap sugar concentration in Eucalyptus globules, Plant Physiol., 131, 1544-1554, 2003. Farquhar, G. D., O'Leary, M. H. and Berry, J. A.: On the relationship between carbon isotope discrimination and the intercellular carbon dioxide concentration in leaves, Aust. J. Plant Physiol., 9, 121-137, 1982. Scheidegger, Y., Saurer, M., Bahn, M. and Siegwolf, R.: Linking stable oxygen and carbon isotopes with stomatal conductance and photosynthetic capacity: A conceptual model</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ZPhyC..65..619A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ZPhyC..65..619A"><span id="translatedtitle">A measurement of the electronic <span class="hlt">widths</span> Γ ee of the ϒ(1 S), ϒ(2 S), and ϒ(4 S) resonances, and of the total decay <span class="hlt">width</span> Γ of the ϒ(4 S)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Albrecht, H.; Hamacher, T.; Hofmann, R. P.; Kirchhoff, T.; Mankel, R.; Nau, A.; Nowak, S.; Reßing, D.; Schröder, H.; Schulz, H. D.; Walter, M.; Wurth, R.; Hast, C.; Kapitza, H.; Kolanoski, H.; Kosche, A.; Lange, A.; Lindner, A.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Töpfer, D.; Wegener, D.; Eckstein, P.; Schmidtler, M.; Schramm, M.; Schubert, K. R.; Schwierz, R.; Waldi, R.; Reim, K.; Wegener, H.; Eckmann, R.; Kuipers, H.; Mai, O.; Mundt, R.; Oest, T.; Reiner, R.; Schmidt-Parzefall, W.; Funk, W.; Stiewe, J.; Werner, S.; Ehret, K.; Hofmann, W.; Hüpper, A.; Knöpfle, K. T.; Spengler, J.; Krieger, P.; Macfarlane, D. B.; Prentice, J. D.; Saull, P. R. B.; Tzamariudaki, K.; van de Water, R. G.; Yoon, T.-S.; Frankl, C.; Schneider, M.; Weseler, S.; Kernel, G.; Križan, P.; Križnič, E.; Podobnik, T.; Živko, T.; Balagura, V.; Barsuk, S.; Belyaev, I.; Chistov, R.; Danilov, M.; Gershtein, L.; Gershtein, Yu.; Golutvin, A.; Korolko, I.; Kostina, G.; Litvintsev, D.; Pakhlov, P.; Semenov, S.; Snizhko, A.; Tichomirov, I.; Zaitsev, Yu.</p> <p>1995-12-01</p> <p>The partial decay <span class="hlt">width</span> into electrons, Γ ee , of the ϒ(1 S) and ϒ(2 S) resonances have been measured with the detector ARGUS at the e + e - storage <span class="hlt">ring</span> DORISII of DESY. Applying the formula of Kuraev and Fadin for the radiative corrections we find: Γ ee (ϒ(1 S))= (1.32±0.04±0.03) keV and Γ ee (ϒ(2 S))=(0.52±0.03±0.01) keV. The total decay <span class="hlt">width</span> of the ϒ(4 S) resonance and its partial <span class="hlt">width</span> into electrons have been determined as well. Fitting the data with a generalized Breit-Wigner function with an energy dependent decay <span class="hlt">width</span> Γ( s) and a mass shift function m(s), we obtain the following resonance parameters: Γ( M 2)=(10.0±2.8±2.7) MeV, Γ ee =(0.28±0.05±0.01)keV and B ee =(2.77±0.50±0.49)·10-5. We argue that the disagrecment of this result with the world average originates from our more adequate parametrization of the observed ϒ(4 S) resonance cross section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhB...44x5701A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhB...44x5701A"><span id="translatedtitle">Stark <span class="hlt">width</span> measurements of Fe II lines with wavelengths in the range 230-260 nm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguilera, J. A.; Manrique, J.; Aragón, C.</p> <p>2011-12-01</p> <p>The experimental Stark <span class="hlt">widths</span> of 26 Fe II lines with wavelengths in the range 230-260 nm have been determined by laser-induced breakdown spectroscopy. These measurements complete the data reported previously for the wavelength range 260-300 nm. The laser-induced plasmas have been generated from Fe-Cu and Fe-Ni samples. The curve-of-<span class="hlt">growth</span> methodology is used to determine the iron concentration required to avoid self-absorption. The electron density at the different instants of the plasma lifetime, determined from the Stark broadening of the Hα line, is in the range (1.6-7.4) × 1017 cm-3. The plasma temperature is in the range 12 900-15 200 K. The Stark <span class="hlt">widths</span> obtained are compared with previous experimental and theoretical data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......168A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......168A"><span id="translatedtitle">Reconstructing climate variability using tree <span class="hlt">rings</span> and glacier fluctuations in the southern Chilean Andes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aravena, Juan-Carlos</p> <p></p> <p>This thesis investigates climate variability in southern South America (south of 40°S) during the last 400 years using instrumental data, tree <span class="hlt">rings</span> and glacier fluctuations. The dominant spatial and temporal patterns of a network of 25 homogeneous instrumental rainfall records were analyzed and used to define four regional precipitation series (1950-2000): northwestern Patagonia, central Patagonia, Patagonian plains-Atlantic, and southern Patagonia. Time series analysis of these regional patterns shows marked decadal variability for northwestern and central Patagonia, 3-7 year oscillations for Patagonian plains-Atlantic region, and a strong biannual oscillatory mode for southern Patagonia. Regional rainfall appears to be strongly influenced by Antarctic circulation modes (Antarctic Oscillation Index) while the ENSO influence on rainfall variability is less evident. Highly significant correlation of precipitation on the west coast of Patagonia with the pressure gradient between the subtropical eastern Pacific and the high-latitude south eastern Pacific is confirmed. A new network of 18 tree-<span class="hlt">ring</span> chronologies from Pilgerodendron uviferum, an endemic conifer, was developed from sites along the western flank of the southern Andes. Highly significant series inter-correlation values ranged between 0.44 and 0.629 while mean sensitivity values ranged between 0.186 and 0.252. The series have relatively few missing <span class="hlt">rings</span> (0.77-0.12% in individual chronologies). The oldest Pilgerodendron sampled to date was 859 years old while the chronology length ranged between 239 and 633 years. <span class="hlt">Ring-width</span> series are correlated with precipitation but there were difficulties developing strong precipitation/<span class="hlt">ring-width</span> relationships for individual stations/sites. However, two regional rainfall reconstructions were developed based on the inverse correlation between Pilgerodendron radial <span class="hlt">growth</span> and the precipitation of northwestern and southern Patagonia. The reconstruction for spring</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6854792','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6854792"><span id="translatedtitle">New instability of Saturn's <span class="hlt">ring</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Goertz, C.K.; Morfill, G.</p> <p>1988-05-01</p> <p>Perturbations in the Saturn <span class="hlt">ring</span>'s mass density are noted to be prone to instabilities through the sporadic elevation of submicron-size dust particles above the <span class="hlt">rings</span>, which furnishes an effective angular momentum exchange between the <span class="hlt">rings</span> and Saturn. The dust thus elevated from the <span class="hlt">ring</span> settles back onto it at a different radial distance. The range of wavelength instability is determinable in light of the dust charge, the average radial displacement of the dust, and the fluctuation of these quantities. It is suggested that at least some of the B-<span class="hlt">ring</span>'s ringlets may arise from the instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013961"><span id="translatedtitle">Planetary <span class="hlt">ring</span> dynamics and morphology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cuzzi, Jeffrey N.; Durisen, Richard H.; Shu, Frank H.</p> <p>1987-01-01</p> <p>Evidence for a moonlet belt in the region between Saturn's close-in moonrings Pandora and Prometheus is discussed. It is argued that little-known observations of magnetospheric electron density by Pioneer 11 imply substantial, ongoing injections of mass into the 2000 km region which surrounds the F <span class="hlt">ring</span>. A hypothesis is presented that these events result naturally from interparticle collisions between the smaller members of an optically thin belt of moonlets. Also discussed is work on Uranus <span class="hlt">ring</span> structure and photometry, image processing and analysis of the Jonian <span class="hlt">ring</span> strucure, photometric and structural studies of the A <span class="hlt">ring</span> of Saturn, and improvements to an image processing system for <span class="hlt">ring</span> studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006EOSTr..87R.463Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006EOSTr..87R.463Z"><span id="translatedtitle">New <span class="hlt">rings</span> found around Saturn</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zielinski, Sarah</p> <p>2006-10-01</p> <p>Images of Saturn taken by the Cassini spacecraft's wide-angle camera in September, with the Sun directly behind the planet, have revealed the existence of two new <span class="hlt">rings</span> around the planet and have confirmed the presence of two other suspected <span class="hlt">rings</span>, NASA announced on11 October. Two of the <span class="hlt">rings</span> are associated with, and share the orbits of, one or more Saturn moonlets, and scientists expect to find a moonlet in at least one of the other two <span class="hlt">rings</span>. Because the moonlets are so small, their gravity is too weak to retain material on their surfaces when struck by meteoroids, and this material creates diffuse <span class="hlt">rings</span> along theirpaths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/535509','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/535509"><span id="translatedtitle">Development of a rainfall sensitive tree-<span class="hlt">ring</span> chronology in Zimbabwe</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stahle, D.W.; Cleaveland, M.K.; Nicholson, S.E.</p> <p>1997-11-01</p> <p>This paper reports the discovery of annual tree <span class="hlt">ring</span> formation in two species of trees in Zimbabwe and describes their paleoclimatic reconstruction potential. Due to the strong influence of El Nino-Southern Oscillation on the climate and crop yields of Zimbabwe and surrenting areas, and the rarity of annual tree <span class="hlt">ring</span> chronologies in the tropics, the discovery of climatically sensitive <span class="hlt">growth</span> <span class="hlt">rings</span> is extremely significant. In particular, the Pterocarpus angolensis shows a strong correlation between the derived tree <span class="hlt">ring</span> chronology and regional rainfall amounts. Based on sampling at the Sikumi Forest, it is speculated that P. angolensis may routinely achieve over 200 years in age. Four lines of evidence are identified which indicate that the semi-<span class="hlt">ring</span> porous <span class="hlt">growth</span> bands in P. angolensis are exactly annual <span class="hlt">growth</span> <span class="hlt">rings</span>. 18 refs., 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC43C0743L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC43C0743L"><span id="translatedtitle">Is the <span class="hlt">Growth</span> of Birch at the UPPER Timberline in the Himalayas Limited By Moisture or By Temperature?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, E.; Dawadi, B.; Pederson, N.; Eckstein, D.</p> <p>2014-12-01</p> <p>Birch (Betula) trees and forests are found across much of the temperate and boreal zones of the Northern Hemisphere. Yet, despite being an ecologically-significant genus, it is much less-well studied compared to common genera like Pinus, Picea, Juniperus, Quercus, and Fagus. In the Himalayas, Himalayan birch (Betula utilis) is a widespread, important broadleaf timberline species that survives in mountain rain shadows via access to water from snowmelt. Because precipitation in the Nepalese Himalayas decreases with increasing elevation, we hypothesized that the <span class="hlt">growth</span> of birch at the upper timberlines between 3,900 and 4,150 m a.s.l. is primarily limited by moisture availability rather than by low temperature. To verify this assumption, a total of 292 increment cores were extracted from 211 birch trees at nine timberline sites. The synchronous occurrence of narrow <span class="hlt">rings</span> and high inter-series correlations within and among sites evidenced a reliable cross-dating and a common climatic signal in the tree-<span class="hlt">ring</span> <span class="hlt">widths</span> variations. From March-May, all nine tree-<span class="hlt">ring</span> <span class="hlt">width</span> site chronologies showed a strongly positive response to total precipitation and a less strongly negative response to temperature. During the instrumental meteorological record (after 1960), years with a high percentage of missing <span class="hlt">rings</span> coincided with pre-monsoon drought events. Periods of below-average <span class="hlt">growth</span> are in phase with well-known drought events all over monsoon Asia, showing additional evidence that Himalayan birch <span class="hlt">growth</span> at the upper timberlines is persistently limited by moisture availability. Our study describes the rare case of a drought-induced altitudinal timberline that is composed by a broadleaf tree species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP44B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP44B..08S"><span id="translatedtitle">Seeing the Forest for the Tree(<span class="hlt">ring</span>)s: Guarding Against False Discovery in Large-Scale Dendroclimatology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>St George, S.</p> <p>2014-12-01</p> <p>Measurements of tree-<span class="hlt">ring</span> <span class="hlt">widths</span> are the most widely-distributed and best replicated source of surrogate environmental information on the planet, and are one of the main archives used to estimate changes in regional and global climate during the past several centuries or millennia. Because the Northern Hemisphere <span class="hlt">ring-width</span> network is now so large, it is more crucial than ever to ensure our understanding of tree-environment relations is not influenced by decisions to include or exclude certain records. It may be the case that a particular set of <span class="hlt">ring-width</span> records are, for whatever reason, more tightly coupled to a particular climate factor than other records from the same region or species and, as a result, may be superior estimators of that factor's past behavior. At the same time, it is known that selecting a small number of predictors from a large pool of potential candidates increases the likelihood of a Type I error. That effect may be particularly relevant to dendroclimatology because the total number of available <span class="hlt">ring-width</span> records is often much larger than the number of records used to produce reconstructions of large-scale climate features. As an initial step, it would be helpful if paleoclimate reconstructions derived from tree <span class="hlt">rings</span> described more explicitly the criteria used to select <span class="hlt">ring-width</span> records as potential predictors and specified those records excluded by that screening. By comparing <span class="hlt">ring-width</span> chronologies and their relations with climate against the standard set by thousands of records across the hemisphere, we should be better able to distinguish climate signals from proxy noise and produce more accurate reconstructions of climate during the late Holocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.171.1983P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.171.1983P"><span id="translatedtitle">Imprint of Climate Variability on Mesozoic Fossil Tree <span class="hlt">Rings</span>: Evidences of Solar Activity Signals on Environmental Records Around 200 Million Years Ago?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prestes, A.; Rigozo, N. R.; Nordemann, D. J. R.; Echer, E.; Vieira, L. E. A.; Souza Echer, M. P.; Wrasse, C. M.; Guarnieri, F. L.</p> <p>2014-08-01</p> <p>Evidence of the solar activity modulation of the Earth's climate has been observed on several parameters, from decadal to millennial time scales. Several proxies have been used to reconstruct the paleoclimate as well as the solar activity. The paleoclimate reconstructions are based on direct and/or indirect effects of global and regional climate conditions. The solar activity reconstructions are based on the production of the 14C isotope due to the interaction of cosmic ray flux and the Earth's atmosphere. Because trees respond to climate conditions and store 14C, they have been used as proxies for both for climate and solar activity reconstructions. The imprints of solar activity cycles dating back to 10,000 years ago have been observed on tree-<span class="hlt">ring</span> samples using 14C data, and those dating back to 20 million years ago have been analyzed using fossil tree-<span class="hlt">growth</span> <span class="hlt">rings</span>. All this corresponds to the Cenozoic era. However, solar activity imprints on tree <span class="hlt">rings</span> from earlier than that era have not been investigated yet. In this work, we showed that tree <span class="hlt">rings</span> from the Mesozoic Era (of ~200 million years ago) recorded 11- and 22-year cycles, which may be related to solar activity cycles, and that were statistically significant at the 95 % confidence level. The fossil wood was collected in the southern region of Brazil. Our analysis of the fossils' tree-<span class="hlt">ring</span> <span class="hlt">width</span> series power spectra showed characteristics similar to the modern araucaria tree, with a noticeable decadal periodicity. Assuming that the Earth's climate responds to solar variability and that responses did not vary significantly over the last ~200 million years, we conclude that the solar-climate connection was likely present during the Mesozoic era.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ClDy...33..331S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ClDy...33..331S"><span id="translatedtitle">Tree-<span class="hlt">ring</span> based hydroclimate reconstruction over northern Vietnam from Fokienia hodginsii: eighteenth century mega-drought and tropical Pacific influence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sano, Masaki; Buckley, Brendan M.; Sweda, Tatsuo</p> <p>2009-08-01</p> <p>We present here the first statistically calibrated and verified tree-<span class="hlt">ring</span> reconstruction of climate from continental Southeast Asia. The reconstructed variable is March-May (MAM) Palmer Drought Severity Index (PDSI) based on <span class="hlt">ring</span> <span class="hlt">widths</span> from 22 trees (42 radial cores) of rare and long-lived conifer, Fokienia hodginsii (Po Mu as locally called) from northern Vietnam. This is the first published tree <span class="hlt">ring</span> chronology from Vietnam as well as the first for this species. Spanning 535 years, this is the longest cross-dated tree-<span class="hlt">ring</span> series yet produced from continental Southeast Asia. Response analysis revealed that the annual <span class="hlt">growth</span> of Fokienia at this site was mostly governed by soil moisture in the pre-monsoon season. The reconstruction passed the calibration-verification tests commonly used in dendroclimatology, and revealed two prominent periods of drought in the mid-eighteenth and late-nineteenth centuries. The former lasted nearly 30 years and was concurrent with a similar drought over northwestern Thailand inferred from teak <span class="hlt">rings</span>, suggesting a “mega-drought” extending across Indochina in the eighteenth century. Both of our reconstructed droughts are consistent with the periods of warm sea surface temperature (SST) anomalies in the tropical Pacific. Spatial correlation analyses with global SST indicated that ENSO-like anomalies might play a role in modulating droughts over the region, with El Niño (warm) phases resulting in reduced rainfall. However, significant correlation was also seen with SST over the Indian Ocean and the north Pacific, suggesting that ENSO is not the only factor affecting the climate of the area. Spectral analyses revealed significant peaks in the range of 53.9-78.8 years as well as in the ENSO-variability range of 2.0 to 3.2 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4982320','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4982320"><span id="translatedtitle">Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial <span class="hlt">Growth</span> and Wood Density in Southern Portugal</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kurz-Besson, Cathy B.; Lousada, José L.; Gaspar, Maria J.; Correia, Isabel E.; David, Teresa S.; Soares, Pedro M. M.; Cardoso, Rita M.; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M.; Gouveia, Célia M.</p> <p>2016-01-01</p> <p>Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant <span class="hlt">growth</span>. It is not clear to what extent wood <span class="hlt">growth</span> and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-<span class="hlt">ring</span> <span class="hlt">width</span> and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-<span class="hlt">growth</span>/density relationships were evaluated for the period 1958-2011. We show that both wood radial <span class="hlt">growth</span> and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial <span class="hlt">growth</span> and density. Despite of the intensification of long-term water deficit, tree-<span class="hlt">ring</span> <span class="hlt">width</span> appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-<span class="hlt">ring</span> density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster’s vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster’s production capacity and quality in response to more arid conditions in the near future in the region. PMID:27570527</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27570527','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27570527"><span id="translatedtitle">Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial <span class="hlt">Growth</span> and Wood Density in Southern Portugal.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kurz-Besson, Cathy B; Lousada, José L; Gaspar, Maria J; Correia, Isabel E; David, Teresa S; Soares, Pedro M M; Cardoso, Rita M; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M; Gouveia, Célia M</p> <p>2016-01-01</p> <p>Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant <span class="hlt">growth</span>. It is not clear to what extent wood <span class="hlt">growth</span> and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-<span class="hlt">ring</span> <span class="hlt">width</span> and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-<span class="hlt">growth</span>/density relationships were evaluated for the period 1958-2011. We show that both wood radial <span class="hlt">growth</span> and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial <span class="hlt">growth</span> and density. Despite of the intensification of long-term water deficit, tree-<span class="hlt">ring</span> <span class="hlt">width</span> appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-<span class="hlt">ring</span> density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster's vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster's production capacity and quality in resp