How Are They Now? Longer Term Effects of eCoaching through Online Bug-in-Ear Technology
ERIC Educational Resources Information Center
Rock, Marcia L.; Schumacker, Randall E.; Gregg, Madeleine; Howard, Pamela W.; Gable, Robert A.; Zigmond, Naomi
2014-01-01
In this study, using mixed methods, we investigated the longer term effects of eCoaching through advanced online bug-in-ear (BIE) technology. Quantitative data on five dependent variables were extracted from 14 participants' electronically archived video files at three points in time--Spring 1 (i.e., baseline, which was the first semester of…
Forecasting Glacier Evolution and Hindcasting Paleoclimates In Light of Mass Balance Nonlinearities
NASA Astrophysics Data System (ADS)
Malone, A.; Doughty, A. M.; MacAyeal, D. R.
2016-12-01
Glaciers are commonly used barometers of present and past climate change, with their variations often being linked to shifts in the mean climate. Climate variability within a unchanging mean state, however, can produce short term mass balance and glacier length anomalies, complicating this linkage. Also, the mass balance response to this variability can be nonlinear, possibly impacting the longer term state of the glacier. We propose a conceptual model to understand these nonlinearities and quantify their impacts on the longer term mass balance and glacier length. The relationship between mass balance and elevation, i.e. the vertical balance profile (VBP), illuminates these nonlinearities (Figure A). The VBP, given here for a wet tropical glacier, is piecewise, which can lead to different mass balance responses to climate anomalies of similar magnitude but opposite sign. We simulate the mass balance response to climate variability by vertically (temperature anomalies) and horizontally (precipitation anomalies) transposing the VBP for the mean climate (Figure A). The resulting anomalous VBP is the superposition of the two translations. We drive a 1-D flowline model with 10,000 years of anomalous VBPs. The aggregate VBP for the mean climate including variability differs from the VBP for the mean climate excluding variability, having a higher equilibrium line altitude (ELA) and a negative mass balance (Figure B). Accordingly, the glacier retreats, and the equilibrium glacier length for the aggregate VBP is the same as the mean length from the 10,000 year flowline simulation (Figure C). The magnitude of the VBP shift and glacier retreat increases with greater temperature variability and larger discontinuities in the VBP slope. These results highlight the importance of both the climate mean and variability in determining the longer term state of the glacier. Thus, forecasting glacier evolution or hindcasting past climates should also include representation of climate variability.
NASA Astrophysics Data System (ADS)
Soon, Willie W.-H.
2005-08-01
This letter offers new evidence motivating a more serious consideration of the potential Arctic temperature responses as a consequence of the decadal, multidecadal and longer-term persistent forcing by the ever-changing solar irradiance both in terms of total solar irradiance (TSI, i.e., integrated over all wavelengths) and the related UV irradiance. The support for such a solar modulator can be minimally derived from the large (>75%) explained variance for the decadally-smoothed Arctic surface air temperatures (SATs) by TSI and from the time-frequency structures of the TSI and Arctic SAT variability as examined by wavelet analyses. The reconstructed Arctic SAT time series based on the inverse wavelet transform, which includes decadal (5-15 years) and multidecadal (40-80 years) variations and a longer-term trend, contains nonstationary but persistent features that are highly correlated with the Sun's intrinsic magnetic variability especially on multidecadal time scales.
1999-09-30
history. OBJECTIVES 1) Is the variability in a river’s sediment load, observed over the last 100 years or less, adequate to provide a proxy for longer-term...experiments, small basins are able to capture in terms of textural proxies , both the natural variability associated with precipitation and temperature...as well as realistic scenarios of abrupt climate change. Open ocean basins, like the Eel River, are less likely to record the proxy record of ambient
Sherr, Jennifer; Tamborlane, William V; Xing, Dongyuan; Tsalikian, Eva; Mauras, Nelly; Buckingham, Bruce; White, Neil H; Arbelaez, Ana Maria; Beck, Roy W; Kollman, Craig; Ruedy, Katrina
2012-04-01
To determine exposure to hyper- and hypoglycemia using blinded continuous glucose monitoring (CGM) profiles in youth with type 1 diabetes (T1D) with residual β-cell function during the first year of insulin treatment. Blinded, 3-7 day CGM profiles were obtained in 16 short-term T1D patients (age 8-18 years, T1D duration 6-52 weeks) who had peak C-peptide levels ranging from 0.46 to 1.96 nmol/L during a mixed-meal tolerance test. Results in this short-term group were compared with those in 34 patients with well-controlled, longer-term T1D (duration ≥5 years), matched for age and A1C with the short-term T1D group, and with those in 26 age-matched nondiabetic individuals. Despite matching for A1C, and therefore similar mean sensor glucose levels in the two T1D groups, short-term T1D participants had a lower frequency of hypoglycemia (0.3 vs. 7.6%, P < 0.001), a trend toward less hyperglycemia (17 vs. 32%, P = 0.15), and a greater percentage in the target range (median 77 vs. 60%, P = 0.02). Indeed, the percentage of sensor glucose levels ≤70 mg/dL in the short-term T1D group (0.3%) did not differ from those in the nondiabetic group (1.7%, P = 0.73). The coefficient of variation of sensor glucose levels (an index of glucose variability) was lower in short-term vs. longer-term T1D participants (27 vs. 42%, respectively, P < 0.001). In youth with short-term T1D who retain residual β-cell function, there is negligible exposure to hypoglycemia and lower glucose variability than in youth with well-controlled T1D of longer duration.
NASA Astrophysics Data System (ADS)
Ashjian, C. J.; Okkonen, S. R.; Campbell, R. G.; Alatalo, P.
2014-12-01
Late summer physical and biological conditions along a 37-km transect crossing Barrow Canyon have been described for the past ten years as part of an ongoing program, supported by multiple funding sources including the NSF AON, focusing on inter-annual variability and the formation of a bowhead whale feeding hotspot near Barrow. These repeated transects (at least two per year, separated in time by days-weeks) provide an opportunity to assess the inter-annual and shorter term (days-weeks) changes in hydrographic structure, ocean temperature, current velocity and transport, chlorophyll fluorescence, nutrients, and micro- and mesozooplankton community composition and abundance. Inter-annual variability in all properties was high and was associated with larger scale, meteorological forcing. Shorter-term variability could also be high but was strongly influenced by changes in local wind forcing. The sustained sampling at this location provided critical measures of inter-annual variability that should permit detection of longer-term trends that are associated with ongoing climate change.
Long-Period Variability in o Ceti
NASA Astrophysics Data System (ADS)
Templeton, Matthew R.; Karovska, Margarita
2009-02-01
We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an unbroken light curve from 1902 to the present, assembled from the visual data archives of five major variable star observing organizations from around the world. We applied several time-series analysis techniques to search for two specific kinds of variability: long secondary periods (LSPs) longer than the dominant pulsation period of ~333 days, and long-term period variation in the dominant pulsation period itself. The data quality is sufficient to detect coherent periodic variations with photometric amplitudes of 0.05 mag or less. We do not find evidence for coherent LSPs in o Ceti to a limit of 0.1 mag, where the amplitude limit is set by intrinsic, stochastic, low-frequency variability of approximately 0.1 mag. We marginally detect a slight modulation of the pulsation period similar in timescale to that observed in the Miras with meandering periods, but with a much lower period amplitude of ±2 days. However, we do find clear evidence of a low-frequency power-law component in the Fourier spectrum of o Ceti's long-term light curve. The amplitude of this stochastic variability is approximately 0.1 mag at a period of 1000 days, and it exhibits a turnover for periods longer than this. This spectrum is similar to the red noise spectra observed in red supergiants.
Ryberg, Karen R.; Vecchia, Aldo V.; Akyüz, F. Adnan; Lin, Wei
2016-01-01
Historically unprecedented flooding occurred in the Souris River Basin of Saskatchewan, North Dakota and Manitoba in 2011, during a longer term period of wet conditions in the basin. In order to develop a model of future flows, there is a need to evaluate effects of past multidecadal climate variability and/or possible climate change on precipitation. In this study, tree-ring chronologies and historical precipitation data in a four-degree buffer around the Souris River Basin were analyzed to develop regression models that can be used for predicting long-term variations of precipitation. To focus on longer term variability, 12-year moving average precipitation was modeled in five subregions (determined through cluster analysis of measures of precipitation) of the study area over three seasons (November–February, March–June and July–October). The models used multiresolution decomposition (an additive decomposition based on powers of two using a discrete wavelet transform) of tree-ring chronologies from Canada and the US and seasonal 12-year moving average precipitation based on Adjusted and Homogenized Canadian Climate Data and US Historical Climatology Network data. Results show that precipitation varies on long-term (multidecadal) time scales of 16, 32 and 64 years. Past extended pluvial and drought events, which can vary greatly with season and subregion, were highlighted by the models. Results suggest that the recent wet period may be a part of natural variability on a very long time scale.
TECHNOLOGICAL CONSIDERATIONS FOR PLANNING THE GLOBAL CARBON FUTURE
The atmospheric level of carbon dioxide (CO2) is the dominant variable in the anthropogenic influence of future global climate change. Thus, it is critical to understand the long-term factors affecting its level, especially the longer-range technological considerations. Most rece...
Exercise motivation, eating, and body image variables as predictors of weight control.
Teixeira, Pedro J; Going, Scott B; Houtkooper, Linda B; Cussler, Ellen C; Metcalfe, Lauve L; Blew, Rob M; Sardinha, Luis B; Lohman, Timothy G
2006-01-01
This study investigated changes in psychosocial variables related to exercise, eating, and body image during a weight reduction program and evaluated their association with weight loss in middle-aged overweight and obese women up to 1 yr after intervention. The 136 participants (age, 48.1 +/- 4.4 yr; weight, 30.6 +/- 5.6 kg x m(-2)) who completed the 4-month lifestyle weight reduction program (86% retention), losing -6.2 +/- 4.6% (P < 0.001) of their initial weight, were followed up for 12 additional months. Of these, 82% completed 16-month assessments (weight change, -5.5 +/- 7.7%, P < 0.001). Psychosocial variables were assessed by validated instruments in standardized conditions at baseline and after the intervention (4 months). Compared with 4-month assessments, body weight did not change at 16 months (P > 0.09). Changes in eating restraint, disinhibition, and hunger; exercise, self-efficacy, and intrinsic motivation; body shape concerns; and physical self-worth were associated with weight change at 4 months (P < 0.001, except hunger, P < 0.05). Baseline-adjusted 4-month scores in all psychosocial variables also predicted weight change from baseline to 16 months (P < 0.01), except hunger (P > 0.05). After controlling for 4-month weight change and other covariates, increases in exercise intrinsic motivation remained predictive of weight loss at 16 months (P < 0.05). Multiple linear regression showed that eating variables were significant and independent correlates of short-term weight change, whereas changes in exercise variables were stronger predictors of longer term weight outcomes. Results highlight the importance of cognitive processes during weight control and support the notion that initial focus on diet is associated with short-term weight loss, while change in exercise-related motivational factors, with a special emphasis on intrinsic sources of motivation (e.g., interest and enjoyment in exercise), play a more important role in longer term weight management.
Routson, Cody C.; Woodhouse, Connie A.; Overpeck, Jonathan T.; Betancourt, Julio L.; McKay, Nicholas P.
2016-01-01
Western North America (WNA) is rich in hydroclimate reconstructions, yet questions remain about the causes of decadal-to-multidecadal hydroclimate variability. Teleconnection patterns preserved in annually-resolved tree-ring reconstructed drought maps, and anomalies in a global network of proxy sea surface temperature (SST) reconstructions, were used to reassess the evidence linking ocean forcing to WNA hydroclimate variability over the past millennium. Potential forcing mechanisms of the Medieval Climate Anomaly (MCA) and individual drought and pluvial events—including two multidecadal-length MCA pluvials—were evaluated. We show strong teleconnection patterns occurred during the driest (wettest) years within persistent droughts (pluvials), implicating SSTs as a potent hydroclimate forcing mechanism. The role of the SSTs on longer timescales is more complex. Pacific teleconnection patterns show little long-term change, whereas low-resolution SST reconstructions vary over decades to centuries. While weaker than the tropical Pacific teleconnections, North Atlantic teleconnection patterns and SST reconstructions also show links to WNA droughts and pluvials, and may in part account for longer-term WNA hydroclimate changes. Nonetheless, evidence linking WNA hydroclimate to SSTs still remains sparse and nuanced—especially over long-timescales with a broader range of hydroclimatic variability than characterized during the 20th century.
Killaspy, Helen; White, Sarah; Wright, Christine; Taylor, Tatiana L; Turton, Penny; Kallert, Thomas; Schuster, Mirjam; Cervilla, Jorge A; Brangier, Paulette; Raboch, Jiri; Kalisova, Lucie; Onchev, Georgi; Alexiev, Spiridon; Mezzina, Roberto; Ridente, Pina; Wiersma, Durk; Visser, Ellen; Kiejna, Andrzej; Piotrowski, Patryk; Ploumpidis, Dimitris; Gonidakis, Fragiskos; Caldas-de-Almeida, José Miguel; Cardoso, Graça; King, Michael
2012-01-01
The Quality Indicator for Rehabilitative Care (QuIRC) is a staff rated, international toolkit that assesses care in longer term hospital and community based mental health facilities. The QuIRC was developed from review of the international literature, an international Delphi exercise with over 400 service users, practitioners, carers and advocates from ten European countries at different stages of deinstitutionalisation, and review of the care standards in these countries. It can be completed in under an hour by the facility manager and has robust content validity, acceptability and inter-rater reliability. In this study, we investigated the internal validity of the QuIRC. Our aim was to identify the QuIRC domains of care that independently predicted better service user experiences of care. At least 20 units providing longer term care for adults with severe mental illness were recruited in each of ten European countries. Service users completed standardised measures of their experiences of care, quality of life, autonomy and the unit's therapeutic milieu. Unit managers completed the QuIRC. Multilevel modelling allowed analysis of associations between service user ratings as dependent variables with unit QuIRC domain ratings as independent variables. 1750/2495 (70%) users and the managers of 213 units from across ten European countries participated. QuIRC ratings were positively associated with service users' autonomy and experiences of care. Associations between QuIRC ratings and service users' ratings of their quality of life and the unit's therapeutic milieu were explained by service user characteristics (age, diagnosis and functioning). A hypothetical 10% increase in QuIRC rating resulted in a clinically meaningful improvement in autonomy. Ratings of the quality of longer term mental health facilities made by service managers were positively associated with service users' autonomy and experiences of care. Interventions that improve quality of care in these settings may promote service users' autonomy.
Arcas, M Marta; Delclos, George L; Torá-Rocamora, Isabel; Martínez, José Miguel; Benavides, Fernando G
2016-11-01
There is wide evidence that women present longer duration of sickness absence (SA) than men. Musculoskeletal disorders are influenced by gender due to the sexual division of work. 354 432 episodes of non-work-related SA due to musculoskeletal disorders, which were registered in Catalonia between 2005 and 2008, were selected. The outcome variable was the duration of SA. Frailty survival models, stratified by sex and adjusted for explanatory variables (age, employment status, case management, economic activity and repeated episode), were fitted to study the association between each variable and the duration of SA, obtaining HRs. Women presented longer SA episodes than men in all variable categories. A trend from shorter to longer duration of SA with increasing age was observed in men, whereas in women, it had a fluctuating pattern. Analysing most frequent diagnostic subgroups from the sample, only 'non-specific lumbago' and 'sciatic lumbago' showed these age patterns. Frailty survival models applied to these 2 subgroups confirmed the described age patterns in SA duration. Women have longer non-work-related SA due to musculoskeletal disorders than men. However, while men have longer absences as their age increases, in women some older groups have shorter absences than younger ones. These findings could be explained by gender differences in the interaction between paid work and family demands. Our results highlight the need for continued research on SA from a gender perspective, in order to improve management of SA in terms of clinical practice and public policies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Reward, Punishment, and Cooperation: A Meta-Analysis
ERIC Educational Resources Information Center
Balliet, Daniel; Mulder, Laetitia B.; Van Lange, Paul A. M.
2011-01-01
How effective are rewards (for cooperation) and punishment (for noncooperation) as tools to promote cooperation in social dilemmas or situations when immediate self-interest and longer term collective interest conflict? What variables can promote the impact of these incentives? Although such questions have been examined, social and behavioral…
Monthly means of selected climate variables for 1985 - 1989
NASA Technical Reports Server (NTRS)
Schubert, S.; Wu, C.-Y.; Zero, J.; Schemm, J.-K.; Park, C.-K.; Suarez, M.
1992-01-01
Meteorologists are accustomed to viewing instantaneous weather maps, since these contain the most relevant information for the task of producing short-range weather forecasts. Climatologists, on the other hand, tend to deal with long-term means, which portray the average climate. The recent emphasis on dynamical extended-range forecasting and, in particular measuring and predicting short term climate change makes it important that we become accustomed to looking at variations on monthly and longer time scales. A convenient toll for researchers to familiarize themselves with the variability which occurs in selected parameters on these time scales is provided. The format of the document was chosen to help facilitate the intercomparison of various parameters and highlight the year-to-year variability in monthly means.
Student Success Factors in Graduate Psychology Professional Programs
ERIC Educational Resources Information Center
Newhouse, Noelle K.; Cerniak, Jessica
2016-01-01
Research examining factors contributing to online students' success typically focuses on a single point in time or completion of a single course, as well as individual difference variables, such as learning style or motivation, that may predispose a student to succeed. However, research concerning longer term online student outcomes, such as…
Biofeedback training effects on minimum toe clearance variability during treadmill walking.
Tirosh, Oren; Cambell, Amity; Begg, Rezaul K; Sparrow, W A
2013-08-01
A number of variability analysis techniques, including Poincaré plots and detrended fluctuation analysis (DFA) were used to investigate minimum toe clearance (MTC) control during walking. Ten young adults walked on a treadmill for 10 min at preferred speed in three conditions: (i) no-intervention baseline, (ii) with biofeedback of MTC within a target range, and (iii) no-biofeedback retention. Mean, median, standard deviation (SD), and inter quartile range of MTC during biofeedback (45.57 ± 11.65, 44.98 ± 11.57, 7.08 ± 2.61, 8.58 ± 2.77 mm, respectively) and retention (56.95 ± 20.31, 56.69 ± 20.94, 10.68 ± 5.41, 15.38 ± 10.19 mm) were significantly greater than baseline (30.77 ± 9.49, 30.51 ± 9.49, 3.04 ± 0.77, 3.66 ± 0.91 mm). Relative to baseline, skewness was reduced in biofeedback and retention but only significantly for retention (0.88 ± 0.51, 0.63 ± 0.55, and 0.40 ± 0.40, respectively). Baseline Poincaré measures (SD1 = 0.25, SD2 = 0.34) and DFA (α1 = 0.72 and α2 = 0.64) were lower than biofeedback (SD1 = 0.58, SD2 = 0.83, DFA α1 = 0.76 and α2 = 0.92) with significantly greater variability in retention compared to biofeedback only in the long-term SD2 and α2 analyses. Increased DFA longer-term correlations α2 in retention confirm that a novel gait pattern was acquired with a longer-term variability structure. Short- and long-term variability analyses were both useful in quantifying gait adaptations with biofeedback. The findings provide evidence that MTC can be modified with feedback, suggesting future applications in gait training procedures for impaired populations designed to reduce tripping risk.
NASA Astrophysics Data System (ADS)
Soulsby, Chris; Birkel, Christian; Geris, Josie; Tetzlaff, Doerthe
2016-04-01
Advances in the use of hydrological tracers and their integration into rainfall runoff models is facilitating improved quantification of stream water age distributions. This is of fundamental importance to understanding water quality dynamics over both short- and long-time scales, particularly as water quality parameters are often associated with water sources of markedly different ages. For example, legacy nitrate pollution may reflect deeper waters that have resided in catchments for decades, whilst more dynamics parameters from anthropogenic sources (e.g. P, pathogens etc) are mobilised by very young (<1 day) near-surface water sources. It is increasingly recognised that water age distributions of stream water is non-stationary in both the short (i.e. event dynamics) and longer-term (i.e. in relation to hydroclimatic variability). This provides a crucial context for interpreting water quality time series. Here, we will use longer-term (>5 year), high resolution (daily) isotope time series in modelling studies for different catchments to show how variable stream water age distributions can be a result of hydroclimatic variability and the implications for understanding water quality. We will also use examples from catchments undergoing rapid urbanisation, how the resulting age distributions of stream water change in a predictable way as a result of modified flow paths. The implication for the management of water quality in urban catchments will be discussed.
Identifying Decadal to Multi-decadal Variability in the Pacific by Empirical Mode Decomposition
NASA Astrophysics Data System (ADS)
Sommers, L. A.; Hamlington, B.; Cheon, S. H.
2016-12-01
Large scale climate variability in the Pacific Ocean like that associated with ENSO and the Pacific Decadal Oscillation (PDO) has been shown to have a significant impact on climate and sea level across a range of timescales. The changes related to these climate signals have worldwide impacts on fisheries, weather, and precipitation patterns among others. Understanding these inter-annual to multi-decadal oscillations is imperative to longer term climate forecasts and understanding how climate will behave, and its effect on changes in sea level. With a 110-year reconstruction of sea level, we examine decadal to multi-decadal variability seen in the sea level fluctuations in the Pacific Ocean. Using empirical mode decomposition (EMD), we break down regional sea level into a series of intrinsic mode functions (IMFs) and attempt attribution of these IMFs to specific climate modes of variability. In particular, and not unexpectedly, we identify IMFs associated with the PDO, finding correlations between the PDO Index and IMFs in the Pacific Ocean upwards of 0.6-0.8 over the 110-year reconstructed record. Perhaps more significantly, we also find evidence of a longer multi-decadal signal ( 50-60 years) in the higher order IMFs. This lower frequency variability has been suggested in previous literature as influencing GMSL, but here we find a regional pattern associated with this multi-decadal signal. By identifying and separating these periodic climate signals, we can gain a better understanding of how the sea level variability associated with these modes can impact sea level on short timescales and serve to exacerbate the effects of long-term sea level change.
Ocean angular momentum signals in a climate model and implications for Earth rotation
NASA Astrophysics Data System (ADS)
Ponte, R. M.; Rajamony, J.; Gregory, J. M.
2002-03-01
Estimates of ocean angular momentum (OAM) provide an integrated measure of variability in ocean circulation and mass fields and can be directly related to observed changes in Earth rotation. We use output from a climate model to calculate 240 years of 3-monthly OAM values (two equatorial terms L1 and L2, related to polar motion or wobble, and axial term L3, related to length of day variations) representing the period 1860-2100. Control and forced runs permit the study of the effects of natural and anthropogenically forced climate variability on OAM. All OAM components exhibit a clear annual cycle, with large decadal modulations in amplitude, and also longer period fluctuations, all associated with natural climate variability in the model. Anthropogenically induced signals, inferred from the differences between forced and control runs, include an upward trend in L3, related to inhomogeneous ocean warming and increases in the transport of the Antarctic Circumpolar Current, and a significantly weaker seasonal cycle in L2 in the second half of the record, related primarily to changes in seasonal bottom pressure variability in the Southern Ocean and North Pacific. Variability in mass fields is in general more important to OAM signals than changes in circulation at the seasonal and longer periods analyzed. Relation of OAM signals to changes in surface atmospheric forcing are discussed. The important role of the oceans as an excitation source for the annual, Chandler and Markowitz wobbles, is confirmed. Natural climate variability in OAM and related excitation is likely to measurably affect the Earth rotation, but anthropogenically induced effects are comparatively weak.
NASA Astrophysics Data System (ADS)
Dudley, R. W.; Hodgkins, G. A.; Nielsen, M. G.; Qi, S. L.
2018-07-01
A number of previous studies have examined relations between groundwater levels and hydrologic and meteorological variables over parts of the glacial aquifer system, but systematic analyses across the entire U.S. glacial aquifer system are lacking. We tested correlations between monthly groundwater levels measured at 1043 wells in the U.S. glacial aquifer system considered to be minimally influenced by human disturbance and selected hydrologic and meteorological variables with the goal of extending historical groundwater records where there were strong correlations. Groundwater levels in the East region correlated most strongly with short-term (1 and 3 month) averages of hydrologic and meteorological variables, while those in the Central and West Central regions yielded stronger correlations with hydrologic and meteorological variables averaged over longer time intervals (6-12 months). Variables strongly correlated with high and low annual groundwater levels were identified as candidate records for use in statistical linear models as a means to fill in and extend historical high and low groundwater levels respectively. Overall, 37.4% of study wells meeting data criteria had successful models for high and (or) low groundwater levels; these wells shared characteristics of relatively higher local precipitation, higher local land-surface slope, lower amounts of clay within the surficial sediments, and higher base-flow index. Streamflow and base flow served as explanatory variables in about two thirds of both high- and low-groundwater-level models in all three regions, and generally yielded more and better models compared to precipitation and Palmer Drought Severity Index. The use of variables such as streamflow with substantially longer and more complete records than those of groundwater wells provide a means for placing contemporary groundwater levels in a longer historical context and can support site-specific analyses such as groundwater modeling.
The Role of Fractality in Perceptual Learning: Exploration in Dynamic Touch
ERIC Educational Resources Information Center
Stephen, Damian G.; Arzamarski, Ryan; Michaels, Claire F.
2010-01-01
Perceptual systems must learn to explore and to use the resulting information to hone performance. Optimal performance depends on using information available at many time scales, from the near instantaneous values of variables underlying perception (i.e., detection), to longer term information about appropriate scaling (i.e., calibration), to yet…
Planning during turmoil: credit challenges and healthcare finance. Interview by Carole J. Bolster.
Bigalke, John T; Goldstein, Lisa; Gourdon, Claudia; Jacobson, Catherine A; Kaufman, Kenneth; Long, Ronald R
2008-11-01
The crisis in the financial markets is having a major impact on hospitals' ability to access capital. Providers are seeking longer-term fixed-rate debt rather than shortterm debt. Hospital management teams and their boards need to understand the upside and downside of variable-rate debt and interest rate derivatives.
Hedenius, Martina; Persson, Jonas; Tremblay, Antoine; Adi-Japha, Esther; Veríssimo, João; Dye, Cristina D.; Alm, Per; Jennische, Margareta; Tomblin, J. Bruce; Ullman, Michael T.
2011-01-01
The Procedural Deficit Hypothesis (PDH) posits that Specific Language Impairment (SLI) can be largely explained by abnormalities of brain structures that subserve procedural memory. The PDH predicts impairments of procedural memory itself, and that such impairments underlie the grammatical deficits observed in the disorder. Previous studies have indeed reported procedural learning impairments in SLI, and have found that these are associated with grammatical difficulties. The present study extends this research by examining the consolidation and longer-term procedural sequence learning in children with SLI. The Alternating Serial Reaction Time (ASRT) task was given to children with SLI and typically-developing (TD) children in an initial learning session and an average of three days later to test for consolidation and longer-term learning. Although both groups showed evidence of initial sequence learning, only the TD children showed clear signs of consolidation, even though the two groups did not differ in longer-term learning. When the children were re-categorized on the basis of grammar deficits rather than broader language deficits, a clearer pattern emerged. Whereas both the grammar impaired and normal grammar groups showed evidence of initial sequence learning, only those with normal grammar showed consolidation and longer-term learning. Indeed, the grammar-impaired group appeared to lose any sequence knowledge gained during the initial testing session. These findings held even when controlling for vocabulary or a broad non-grammatical language measure, neither of which were associated with procedural memory. When grammar was examined as a continuous variable over all children, the same relationships between procedural memory and grammar, but not vocabulary or the broader language measure, were observed. Overall, the findings support and further specify the PDH. They suggest that consolidation and longer-term procedural learning are impaired in SLI, but that these impairments are specifically tied to the grammatical deficits in the disorder. The possibility that consolidation and longer-term learning are problematic in the disorder suggests a locus of potential study for therapeutic approaches. In sum, this study clarifies our understanding of the underlying deficits in SLI, and suggests avenues for further research. PMID:21840165
Seasonal Trends of Soiling on Photovoltaic Systems: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muller, Matthew T; Ruth, Daniel; Micheli, Leonardo
This work investigates the seasonal variability of PV soiling losses over a 12-month period for sixteen soiling stations deployed in the USA. A new parameter able to rank the sites according to the cumulative losses occurring over 3- and 6- month periods is presented. The relations between soiling losses and particulate matter are briefly discussed as well. Moving from long-term to shorter-term data increases the complexity of the analysis: monthly correlations are found to have lower accuracy than the longer term ones presented in the literature.
ModelPlex: Verified Runtime Validation of Verified Cyber-Physical System Models
2014-07-01
nondeterministic choice (〈∪〉), deterministic assignment (〈:=〉) and logical con- nectives (∧ r etc.) replace current facts with simpler ones or branch...By sequent proof rule ∃ r , this existentially quantified variable is instantiated with an arbitrary term θ, which is often a new logical variable...that is implicitly existentially quantified [27]. Weakening (Wr) removes facts that are no longer necessary. (〈∗〉) ∃X〈x :=X〉φ 〈x := ∗〉φ 1 (∃ r ) Γ ` φ(θ
Near-infrared Variability in the Orion Nebula Cluster
NASA Astrophysics Data System (ADS)
Rice, Thomas S.; Reipurth, Bo; Wolk, Scott J.; Vaz, Luiz Paulo; Cross, N. J. G.
2015-10-01
Using UKIRT on Mauna Kea, we have carried out a new near-infrared J, H, K monitoring survey of almost a square degree of the star-forming Orion Nebula Cluster with observations on 120 nights over three observing seasons, spanning a total of 894 days. We monitored ˜15,000 stars down to J≈ 20 using the WFCAM instrument, and have extracted 1203 significantly variable stars from our data. By studying variability in young stellar objects (YSOs) in the H - K, K color-magnitude diagram, we are able to distinguish between physical mechanisms of variability. Many variables show color behavior indicating either dust-extinction or disk/accretion activity, but we find that when monitored for longer periods of time, a number of stars shift between these two variability mechanisms. Further, we show that the intrinsic timescale of disk/accretion variability in young stars is longer than that of dust-extinction variability. We confirm that variability amplitude is statistically correlated with evolutionary class in all bands and colors. Our investigations of these 1203 variables have revealed 73 periodic AA Tau type variables, many large-amplitude and long-period (P\\gt 15 days) YSOs, including three stars showing widely spaced periodic brightening events consistent with circumbinary disk activity, and four new eclipsing binaries. These phenomena and others indicate the activity of long-term disk/accretion variability processes taking place in young stars. We have made the light curves and associated data for these 1203 variables available online.
NASA Astrophysics Data System (ADS)
Canion, Andy; MacIntyre, Hugh L.; Phipps, Scott
2013-10-01
The inputs of primary productivity models may be highly variable on short timescales (hourly to daily) in turbid estuaries, but modeling of productivity in these environments is often implemented with data collected over longer timescales. Daily, seasonal, and spatial variability in primary productivity model parameters: chlorophyll a concentration (Chla), the downwelling light attenuation coefficient (kd), and photosynthesis-irradiance response parameters (Pmchl, αChl) were characterized in Weeks Bay, a nitrogen-impacted shallow estuary in the northern Gulf of Mexico. Variability in primary productivity model parameters in response to environmental forcing, nutrients, and microalgal taxonomic marker pigments were analysed in monthly and short-term datasets. Microalgal biomass (as Chla) was strongly related to total phosphorus concentration on seasonal scales. Hourly data support wind-driven resuspension as a major source of short-term variability in Chla and light attenuation (kd). The empirical relationship between areal primary productivity and a combined variable of biomass and light attenuation showed that variability in the photosynthesis-irradiance response contributed little to the overall variability in primary productivity, and Chla alone could account for 53-86% of the variability in primary productivity. Efforts to model productivity in similar shallow systems with highly variable microalgal biomass may benefit the most by investing resources in improving spatial and temporal resolution of chlorophyll a measurements before increasing the complexity of models used in productivity modeling.
Otmani del Barrio, Mariam
2017-01-01
Background: There is limited published evidence of the effectiveness of adaptation in managing the health risks of climate variability and change in low- and middle-income countries. Objectives: To document lessons learned and good practice examples from health adaptation pilot projects in low- and middle-income countries to facilitate assessing and overcoming barriers to implementation and to scaling up. Methods: We evaluated project reports and related materials from the first five years of implementation (2008–2013) of multinational health adaptation projects in Albania, Barbados, Bhutan, China, Fiji, Jordan, Kazakhstan, Kenya, Kyrgyzstan, Philippines, Russian Federation, Tajikistan, and Uzbekistan. We also collected qualitative data through a focus group consultation and 19 key informant interviews. Results: Our recommendations include that national health plans, policies, and budget processes need to explicitly incorporate the risks of current and projected climate variability and change. Increasing resilience is likely to be achieved through longer-term, multifaceted, and collaborative approaches, with supporting activities (and funding) for capacity building, communication, and institutionalized monitoring and evaluation. Projects should be encouraged to focus not just on shorter-term outputs to address climate variability, but also on establishing processes to address longer-term climate change challenges. Opportunities for capacity development should be created, identified, and reinforced. Conclusions: Our analyses highlight that, irrespective of resource constraints, ministries of health and other institutions working on climate-related health issues in low- and middle-income countries need to continue to prepare themselves to prevent additional health burdens in the context of a changing climate and socioeconomic development patterns. https://doi.org/10.1289/EHP405 PMID:28632491
Long-term resilience of above- and below ground ecosystem components among contrasting ecosystems.
Wardle, David A; Jonsson, Micael
2014-07-01
While several studies have explored how short-term ecological responses to disturbance vary among ecosystems, experimental studies of how contrasting ecosystems recover from disturbance in the longer term are few. We performed a simple long-term experiment on each of 30 contrasting forested islands in northern Sweden that vary in size; as size decreases, time since fire increases, soil fertility and ecosystem productivity declines, and plant species diversity increases. We predicted that resilience of understory plant community properties would be greatest on the larger, more productive islands, and that this would be paralleled by greater resilience of soil biotic and abiotic properties. For each island, we applied three disturbance treatments of increasing intensity to the forest understory once in 1998, i.e., light trimming, heavy trimming, and burning; a fourth treatment was an undisturbed control. We measured recovery of the understory vascular plant community annually over the following 14 years, and at that time also assessed recovery of mosses and several belowground variables. Consistent with our predictions, vascular plant whole-community variables (total cover, species richness, diversity [Shannon's H'], and community composition) recovered significantly more slowly on the smaller (least fertile) than the larger islands, but this difference was not substantial, and only noticeable in the most severely disturbed treatment. When an index of resilience was used, we were unable to detect effects of island size on the recovery of any property. We found that mosses and one shrub species (Empetrum hermaphroditum) recovered particularly slowly, and the higher abundance of this shrub on small islands was sufficient to explain any slower recovery of whole-ecosystem variables on those islands. Further, several belowground variables had not fully recovered from the most intense disturbance after 14 yr, and counter to our predictions, the degree of their recovery was never influenced by island size. While several studies have shown large variation among plant communities in their short-term response (notably resistance) to environmental perturbations, our results reveal that when perturbations are applied equally to highly contrasting ecosystems, differences in resilience among them in the longer term can be relatively minor, regardless of the severity of disturbance.
Effects of temporal averaging on short-term irradiance variability under mixed sky conditions
NASA Astrophysics Data System (ADS)
Lohmann, Gerald M.; Monahan, Adam H.
2018-05-01
Characterizations of short-term variability in solar radiation are required to successfully integrate large numbers of photovoltaic power systems into the electrical grid. Previous studies have used ground-based irradiance observations with a range of different temporal resolutions and a systematic analysis of the effects of temporal averaging on the representation of variability is lacking. Using high-resolution surface irradiance data with original temporal resolutions between 0.01 and 1 s from six different locations in the Northern Hemisphere, we characterize the changes in representation of temporal variability resulting from time averaging. In this analysis, we condition all data to states of mixed skies, which are the most potentially problematic in terms of local PV power volatility. Statistics of clear-sky index k* and its increments Δk*τ (i.e., normalized surface irradiance and changes therein over specified intervals of time) are considered separately. Our results indicate that a temporal averaging time scale of around 1 s marks a transition in representing single-point irradiance variability, such that longer averages result in substantial underestimates of variability. Higher-resolution data increase the complexity of data management and quality control without appreciably improving the representation of variability. The results do not show any substantial discrepancies between locations or seasons.
Valuing the Student Loan Consolidation Option. Congressional Budget Office Background Paper
ERIC Educational Resources Information Center
Weinberg, Steven
2006-01-01
Federal student loans include a complex consolidation option that gives borrowers the opportunity to combine several loans into a single loan with a longer term to maturity and, for loans originated before July 2006, to convert from a variable- to a fixed-rate loan. The consolidation option adds substantial costs to the federal student loan…
Detection time for global and regional sea level trends and accelerations
NASA Astrophysics Data System (ADS)
Jordà, G.
2014-10-01
Many studies analyze trends on sea level data with the underlying purpose of finding indications of a long-term change that could be interpreted as the signature of anthropogenic climate change. The identification of a long-term trend is a signal-to-noise problem where the natural variability (the "noise") can mask the long-term trend (the "signal"). The signal-to-noise ratio depends on the magnitude of the long-term trend, on the magnitude of the natural variability, and on the length of the record, as the climate noise is larger when averaged over short time scales and becomes smaller over longer averaging periods. In this paper, we evaluate the time required to detect centennial sea level linear trends and accelerations at global and regional scales. Using model results and tide gauge observations, we find that the averaged detection time for a centennial linear trend is 87.9, 76.0, 59.3, 40.3, and 25.2 years for trends of 0.5, 1.0, 2.0, 5.0, and 10.0 mm/yr, respectively. However, in regions with large decadal variations like the Gulf Stream or the Circumpolar current, these values can increase up to a 50%. The spatial pattern of the detection time for sea level accelerations is almost identical. The main difference is that the length of the records has to be about 40-60 years longer to detect an acceleration than to detect a linear trend leading to an equivalent change after 100 years. Finally, we have used a new sea level reconstruction, which provides a more accurate representation of interannual variability for the last century in order to estimate the detection time for global mean sea level trends and accelerations. Our results suggest that the signature of natural variability in a 30 year global mean sea level record would be less than 1 mm/yr. Therefore, at least 2.2 mm/yr of the recent sea level trend estimated by altimetry cannot be attributed to natural multidecadal variability. This article was corrected on 19 NOV 2014. See the end of the full text for details.
Long-term variability of T Tauri stars using WASP
NASA Astrophysics Data System (ADS)
Rigon, Laura; Scholz, Alexander; Anderson, David; West, Richard
2017-03-01
We present a reference study of the long-term optical variability of young stars using data from the WASP project. Our primary sample is a group of well-studied classical T Tauri stars (CTTSs), mostly in Taurus-Auriga. WASP light curves cover time-scales of up to 7 yr and typically contain 10 000-30 000 data points. We quantify the variability as a function of time-scale using the time-dependent standard deviation 'pooled sigma'. We find that the overwhelming majority of CTTSs have a low-level variability with σ < 0.3 mag dominated by time-scales of a few weeks, consistent with rotational modulation. Thus, for most young stars, monitoring over a month is sufficient to constrain the total amount of variability over time-scales of up to a decade. The fraction of stars with a strong optical variability (σ > 0.3 mag) is 21 per cent in our sample and 21 per cent in an unbiased control sample. An even smaller fraction (13 per cent in our sample, 6 per cent in the control) show evidence for an increase in variability amplitude as a function of time-scale from weeks to months or years. The presence of long-term variability correlates with the spectral slope at 3-5 μm, which is an indicator of inner disc geometry, and with the U-B band slope, which is an accretion diagnostics. This shows that the long-term variations in CTTSs are predominantly driven by processes in the inner disc and in the accretion zone. Four of the stars with long-term variations show periods of 20-60 d, significantly longer than the rotation periods and stable over months to years. One possible explanation is cyclic changes in the interaction between the disc and the stellar magnetic field.
Between Pleasure and Contentment: Evolutionary Dynamics of Some Possible Parameters of Happiness.
Gao, Yue; Edelman, Shimon
2016-01-01
We offer and test a simple operationalization of hedonic and eudaimonic well-being ("happiness") as mediating variables that link outcomes to motivation. In six evolutionary agent-based simulation experiments, we compared the relative performance of agents endowed with different combinations of happiness-related traits (parameter values), under four types of environmental conditions. We found (i) that the effects of attaching more weight to longer-term than to momentary happiness and of extending the memory for past happiness are both stronger in an environment where food is scarce; (ii) that in such an environment "relative consumption," in which the agent's well-being is negatively affected by that of its neighbors, is more detrimental to survival when food is scarce; and (iii) that having a positive outlook, under which agents' longer-term happiness is increased by positive events more than it is decreased by negative ones, is generally advantageous.
Between Pleasure and Contentment: Evolutionary Dynamics of Some Possible Parameters of Happiness
Gao, Yue; Edelman, Shimon
2016-01-01
We offer and test a simple operationalization of hedonic and eudaimonic well-being (“happiness”) as mediating variables that link outcomes to motivation. In six evolutionary agent-based simulation experiments, we compared the relative performance of agents endowed with different combinations of happiness-related traits (parameter values), under four types of environmental conditions. We found (i) that the effects of attaching more weight to longer-term than to momentary happiness and of extending the memory for past happiness are both stronger in an environment where food is scarce; (ii) that in such an environment “relative consumption,” in which the agent’s well-being is negatively affected by that of its neighbors, is more detrimental to survival when food is scarce; and (iii) that having a positive outlook, under which agents’ longer-term happiness is increased by positive events more than it is decreased by negative ones, is generally advantageous. PMID:27144982
ERIC Educational Resources Information Center
Larson, Donald K.; White, Claudia K.
An estimated 44,340 longer term resident households in rural Kentucky were studied to identify the variables that explained changes in household income status between 1974-79. In a nine-county area of south-central Kentucky, rapid employment growth between 1974 and 1979 created new job opportunities, but employment growth did not benefit all…
Ryberg, Karen R.; Vecchia, Aldo V.
2012-01-01
Hydrologic time series data and associated anomalies (multiple components of the original time series representing variability at longer-term and shorter-term time scales) are useful for modeling trends in hydrologic variables, such as streamflow, and for modeling water-quality constituents. An R package, called waterData, has been developed for importing daily hydrologic time series data from U.S. Geological Survey streamgages into the R programming environment. In addition to streamflow, data retrieval may include gage height and continuous physical property data, such as specific conductance, pH, water temperature, turbidity, and dissolved oxygen. The package allows for importing daily hydrologic data into R, plotting the data, fixing common data problems, summarizing the data, and the calculation and graphical presentation of anomalies.
External forcing as a metronome for Atlantic multidecadal variability
NASA Astrophysics Data System (ADS)
Otterå, Odd Helge; Bentsen, Mats; Drange, Helge; Suo, Lingling
2010-10-01
Instrumental records, proxy data and climate modelling show that multidecadal variability is a dominant feature of North Atlantic sea-surface temperature variations, with potential impacts on regional climate. To understand the observed variability and to gauge any potential for climate predictions it is essential to identify the physical mechanisms that lead to this variability, and to explore the spatial and temporal characteristics of multidecadal variability modes. Here we use a coupled ocean-atmosphere general circulation model to show that the phasing of the multidecadal fluctuations in the North Atlantic during the past 600 years is, to a large degree, governed by changes in the external solar and volcanic forcings. We find that volcanoes play a particularly important part in the phasing of the multidecadal variability through their direct influence on tropical sea-surface temperatures, on the leading mode of northern-hemisphere atmosphere circulation and on the Atlantic thermohaline circulation. We suggest that the implications of our findings for decadal climate prediction are twofold: because volcanic eruptions cannot be predicted a decade in advance, longer-term climate predictability may prove challenging, whereas the systematic post-eruption changes in ocean and atmosphere may hold promise for shorter-term climate prediction.
Domeisen, Daniela I. V.
2016-01-01
Characterizing the stratosphere as a turbulent system, temporal fluctuations often show different correlations for different time scales as well as intermittent behaviour that cannot be captured by a single scaling exponent. In this study, the different scaling laws in the long-term stratospheric variability are studied using multifractal de-trended fluctuation analysis (MF-DFA). The analysis is performed comparing four re-analysis products and different realizations of an idealized numerical model, isolating the role of topographic forcing and seasonal variability, as well as the absence of climate teleconnections and small-scale forcing. The Northern Hemisphere (NH) shows a transition of scaling exponents for time scales shorter than about 1 year, for which the variability is multifractal and scales in time with a power law corresponding to a red spectrum, to longer time scales, for which the variability is monofractal and scales in time with a power law corresponding to white noise. Southern Hemisphere (SH) variability also shows a transition at annual scales. The SH also shows a narrower dynamical range in multifractality than the NH, as seen in the generalized Hurst exponent and in the singularity spectra. The numerical integrations show that the models are able to reproduce the low-frequency variability but are not able to fully capture the shorter term variability of the stratosphere. PMID:27493560
An Expanded RXTE Survey of Long-Term X-ray Variability in Seyfert 1 Galaxies
NASA Technical Reports Server (NTRS)
Markowitz, A.; Edelson, R.
2004-01-01
The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogenous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from approx. 1 day to approx. 3.5 years. 2-10 keV variability on time scales of approx. 1 day, as probed by ASCA, are included. All sources exhibit stronger X-ray variability towards longer time scales, with variability amplitudes saturating at the longest time scales, but the increase is greater for relatively higher luminosity sources. The well-documented anticorrelation between variability amplitude and luminosity is confirmed on all time scales. However, anticorrelations between variability amplitude and black hole mass estimate are evident on only the shortest time scales probed. The data are consistent with the models of power spectral density (PSD) movement described in Markowitz et al. (2003) and McHardy et al. (2004), whereby Seyfert 1 galaxies variability can be described by a single, universal PSD shape whose cutoff frequency scales with black hole mass. The best-fitting scaling relations between variability time scale, black hole mass and X-ray luminosity support an average accretion rate of 2% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all time scales. Color-flux diagrams support also Seyfert 1s' softening as they brighten. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.
NASA Astrophysics Data System (ADS)
Brown, R. F.; Collins, S. L.
2017-12-01
Climate is becoming increasingly more variable due to global environmental change, which is evidenced by fewer, but more extreme precipitation events, changes in precipitation seasonality, and longer, higher severity droughts. These changes, combined with a rising incidence of wildfire, have the potential to strongly impact net primary production (NPP) and key biogeochemical cycles, particularly in dryland ecosystems where NPP is sequentially limited by water and nutrient availability. Here we utilize a ten-year dataset from an ongoing long-term field experiment established in 2007 in which we experimentally altered monsoon rainfall variability to examine how our manipulations, along with naturally occurring events, affect NPP and associated biogeochemical cycles in a semi-arid grassland in central New Mexico, USA. Using long-term regional averages, we identified extremely wet monsoon years (242.8 mm, 2013), and extremely dry monsoon years (86.0 mm, 2011; 80.0 mm, 2015) and water years (117.0 mm, 2011). We examined how changes in precipitation variability and extreme events affected ecosystem processes and function particularly in the context of ecosystem recovery following a 2009 wildfire. Response variables included above- and below-ground plant biomass (ANPP & BNPP) and abundance, soil nitrogen availability, and soil CO2 efflux. Mean ANPP ranged from 3.6 g m-2 in 2011 to 254.5 g m-2 in 2013, while BNPP ranged from 23.5 g m-2 in 2015 to 194.2 g m-2 in 2013, demonstrating NPP in our semi-arid grassland is directly linked to extremes in both seasonal and annual precipitation. We also show increased nitrogen deposition positively affects NPP in unburned grassland, but has no significant impact on NPP post-fire except during extremely wet monsoon years. While soil respiration rates reflect lower ANPP post-fire, patterns in CO2 efflux have not been shown to change significantly in that efflux is greatest following large precipitation events preceded by longer drying periods. Current land surface models poorly represent dryland ecosystems, which frequently undergo extreme weather events. Our long-term experiment provides key insights into ecosystem processes and function, thereby providing capacity for model improvement particularly in the context of future environmental change.
NASA Astrophysics Data System (ADS)
Rigon, Laura
2016-03-01
Stars form from the collapse of molecular clouds and evolve in an environment rich in gas and dust before becoming Main Sequence stars. During this phase, characterised by the presence of a protoplanetary disc, stars manifest changes in the structure and luminosity. This thesis performs a multi-wavelength analysis, from optical to mm range, on a sample of young stars (YSOs), mainly Classical T Tauri (CTTS). The purpose is to study optical and infrared variability and its relation with the protoplanetary disc. Longer wavelength, in the mm range, are used instead to investigate the evolution of the disc, in terms of dust growth. In optical, an F-test on a sample of 39 CTTS reveals that 67% of the stars are variable. The variability, quantified through pooled sigma, is visible both in magnitude amplitudes and changes over time. Time series analysis applied on the more variable stars finds the presence of quasi periodicity, with periods longer than two weeks, interpreted either as eclipsing material in the disc happening on a non-regular basis, or as a consequence of star-disc interaction via magnetic field lines. The variability of YSOs is confirmed also in infrared, even if with lower amplitude. No strong correlations are found between optical and infrared variability, which implies a different cause or a time shift in the two events. By using a toy model to explore their origin, I find that infrared variations are likely to stem from emissions in the inner disc. The evolution of discs in terms of dust growth is confirmed in most discs by the analysis of the slope of the spectral energy distribution (SED), after correcting for wind emission and optical depth effects. However, the comparison with a radiative transfer model highlights that a number of disc parameters, in particular disc masses and temperature, dust size distribution and composition, can also affect the slope of the SED.
Birgisdóttir, Kristín Helga; Jónsson, Stefán Hrafn; Ásgeirsdóttir, Tinna Laufey
2017-12-01
Previous research has found a positive short-term relationship between the 2008 collapse and hypertension in Icelandic males. With Iceland's economy experiencing a phase of economic recovery, an opportunity to pursue a longer-term analysis of the collapse has emerged. Using data from a nationally representative sample, fixed-effect estimations and mediation analyses were performed to explore the relationship between the Icelandic economic collapse in 2008 and the longer-term impact on hypertension and cardiovascular health. A sensitivity analysis was carried out with pooled logit models estimated as well as an alternative dependent variable. Our attrition analysis revealed that results for cardiovascular diseases were affected by attrition, but not results from estimations on the relationship between the economic crisis and hypertension. When compared to the boom year 2007, our results point to an increased probability of Icelandic women having hypertension in the year 2012, when the Icelandic economy had recovered substantially from the economic collapse in 2008. This represents a deviation from pre-crisis trends, thus suggesting a true economic-recovery impact on hypertension.
Past climate variability and change in the Arctic and at high latitudes
Alley, Richard B.; Brigham-Grette, Julie; Miller, Gifford H.; Polyak, Leonid; ,; ,; ,
2009-01-01
Paleoclimate records play a key role in our understanding of Earth's past and present climate system and in our confidence in predicting future climate changes. Paleoclimate data help to elucidate past and present active mechanisms of climate change by placing the short instrumental record into a longer term context and by permitting models to be tested beyond the limited time that instrumental measurements have been available.
Kuikka, P-I; Pihlajamäki, H K; Mattila, V M
2013-06-01
The population-based incidence and risk factors for knee injuries in young adults were assessed in Finnish male conscripts performing their compulsory military service (n = 128,584). The main outcome variables were (1) hospitalization due to knee injuries overall and (2) hospitalization due to knee disorders as categorized into specific International Classification of Diseases, tenth revision diagnoses (cruciate and collateral ligament tears, meniscal tears, traumatic chondral lesions, and patellar dislocations). Person-time injury-incidence rates were calculated by dividing the number of persons with a diagnosed knee injury by the total exposure time of 97,503 person-years. The number of subjects with surgical operations and military service class changes indicative of longer term notable disability are also reported. Risk factor analyses were performed by logistic regression. The person-based incidence of hospitalizations for knee injury was 11 cases per 1000 person-years [95% confidence interval (CI): 10.4-11.7]. The most important risk factors were higher age (odds ratio 1.7; 95% CI: 1.3-2.2) and obesity (odds ratio 1.6; 95% CI: 1.03-2.5). Two thirds of all subjects hospitalized for knee injuries had surgery, and one third had longer term notable disability. These findings indicate that knee injuries cause a significant burden of hospitalizations, often leading to surgery and longer term disability. © 2011 John Wiley & Sons A/S.
Turnbull, Christopher D; Bratton, Daniel J; Craig, Sonya E; Kohler, Malcolm; Stradling, John R
2016-02-01
Long-term continuous positive airway pressure (CPAP) usage varies between individuals. It would be of value to be able to identify those who are likely to benefit from CPAP (and use it long term), versus those who would not, and might therefore benefit from additional help early on. First, we explored whether baseline characteristics predicted CPAP usage in minimally symptomatic obstructive sleep apnoea (OSA) patients, a group who would be expected to have low usage. Second, we explored if early CPAP usage was predictive of longer-term usage, as has been shown in more symptomatic OSA patients. The MOSAIC trial was a multi-centre randomised controlled trial where minimally symptomatic OSA patients were randomised to CPAP, or standard care, for 6 months. Here we have studied only those patients randomised to CPAP treatment. Baseline characteristics including symptoms, questionnaires [including the Epworth sleepiness score (ESS)] and sleep study parameters were recorded. CPAP usage was recorded at 2-4 weeks after initiation and after 6 months. The correlation and association between baseline characteristics and 6 months CPAP usage was assessed, as was the correlation between 2 and 4 weeks CPAP usage and 6 months CPAP usage. One hundred and ninety-five patients randomised to CPAP therapy had median [interquartile range (IQR)] CPAP usage of 2:49 (0:44, 5:13) h:min/night (h/n) at the 2-4 weeks visit, and 2:17 (0:08, 4:54) h/n at the 6 months follow-up visit. Only male gender was associated with increased long-term CPAP use (male usage 2:56 h/n, female 1:57 h/n; P=0.02). There was a moderate correlation between the usage of CPAP at 2-4 weeks and 6 months, with about 50% of the variability in long-term use being predicted by the short-term use. In patients with minimally symptomatic OSA, our study has shown that male gender (and not OSA severity or symptom burden) is associated with increased long-term use of CPAP at 6 months. Although, in general, early patterns of CPAP usage predicted longer term use, there are patients in whom this is not the case, and patients with low initial usage may need to extend their CPAP trial before a decision about longer-term use is made.
Impact of climate variability on runoff in the north-central United States
Ryberg, Karen R.; Lin, Wei; Vecchia, Aldo V.
2014-01-01
Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) to changes in runoff within 25 stream basins. The basins studied were organized into four groups, each one representing basins similar in topography, climate, and historic patterns of runoff. Precipitation, PET, and runoff data were adjusted for near-decadal scale variability to examine longer-term changes. A nonlinear water-balance analysis shows that changes in precipitation and PET explain the majority of multidecadal spatial/temporal variability of runoff and flood magnitudes, with precipitation being the dominant driver. Historical changes in climate and runoff in the region appear to be more consistent with complex transient shifts in seasonal climatic conditions than with gradual climate change. A portion of the unexplained variability likely stems from land-use change.
A Data-Driven Diagnostic Framework for Wind Turbine Structures: A Holistic Approach
Bogoevska, Simona; Spiridonakos, Minas; Chatzi, Eleni; Dumova-Jovanoska, Elena; Höffer, Rudiger
2017-01-01
The complex dynamics of operational wind turbine (WT) structures challenges the applicability of existing structural health monitoring (SHM) strategies for condition assessment. At the center of Europe’s renewable energy strategic planning, WT systems call for implementation of strategies that may describe the WT behavior in its complete operational spectrum. The framework proposed in this paper relies on the symbiotic treatment of acting environmental/operational variables and the monitored vibration response of the structure. The approach aims at accurate simulation of the temporal variability characterizing the WT dynamics, and subsequently at the tracking of the evolution of this variability in a longer-term horizon. The bi-component analysis tool is applied on long-term data, collected as part of continuous monitoring campaigns on two actual operating WT structures located in different sites in Germany. The obtained data-driven structural models verify the potential of the proposed strategy for development of an automated SHM diagnostic tool. PMID:28358346
Anomalous Low States and Long Term Variability in the Black Hole Binary LMC X-3
NASA Technical Reports Server (NTRS)
Smale, Alan P.; Boyd, Patricia T.
2012-01-01
Rossi X-my Timing Explorer observations of the black hole binary LMC X-3 reveal an extended very low X-ray state lasting from 2003 December 13 until 2004 March 18, unprecedented both in terms of its low luminosity (>15 times fainter than ever before seen in this source) and long duration (approx 3 times longer than a typical low/hard state excursion). During this event little to no source variability is observed on timescales of approx hours-weeks, and the X-ray spectrum implies an upper limit of 1.2 x 10(exp 35) erg/s, Five years later another extended low state occurs, lasting from 2008 December 11 until 2009 June 17. This event lasts nearly twice as long as the first, and while significant variability is observed, the source remains reliably in the low/hard spectral state for the approx 188 day duration. These episodes share some characteristics with the "anomalous low states" in the neutron star binary Her X-I. The average period and amplitude of the Variability of LMC X-3 have different values between these episodes. We characterize the long-term variability of LMC X-3 before and after the two events using conventional and nonlinear time series analysis methods, and show that, as is the case in Her X-I, the characteristic amplitude of the variability is related to its characteristic timescale. Furthermore, the relation is in the same direction in both systems. This suggests that a similar mechanism gives rise to the long-term variability, which in the case of Her X-I is reliably modeled with a tilted, warped precessing accretion disk.
Interannual drivers of the seasonal cycle of CO2 in the Southern Ocean
NASA Astrophysics Data System (ADS)
Gregor, Luke; Kok, Schalk; Monteiro, Pedro M. S.
2018-04-01
Resolving and understanding the drivers of variability of CO2 in the Southern Ocean and its potential climate feedback is one of the major scientific challenges of the ocean-climate community. Here we use a regional approach on empirical estimates of pCO2 to understand the role that seasonal variability has in long-term CO2 changes in the Southern Ocean. Machine learning has become the preferred empirical modelling tool to interpolate time- and location-restricted ship measurements of pCO2. In this study we use an ensemble of three machine-learning products: support vector regression (SVR) and random forest regression (RFR) from Gregor et al. (2017), and the self-organising-map feed-forward neural network (SOM-FFN) method from Landschützer et al. (2016). The interpolated estimates of ΔpCO2 are separated into nine regions in the Southern Ocean defined by basin (Indian, Pacific, and Atlantic) and biomes (as defined by Fay and McKinley, 2014a). The regional approach shows that, while there is good agreement in the overall trend of the products, there are periods and regions where the confidence in estimated ΔpCO2 is low due to disagreement between the products. The regional breakdown of the data highlighted the seasonal decoupling of the modes for summer and winter interannual variability. Winter interannual variability had a longer mode of variability compared to summer, which varied on a 4-6-year timescale. We separate the analysis of the ΔpCO2 and its drivers into summer and winter. We find that understanding the variability of ΔpCO2 and its drivers on shorter timescales is critical to resolving the long-term variability of ΔpCO2. Results show that ΔpCO2 is rarely driven by thermodynamics during winter, but rather by mixing and stratification due to the stronger correlation of ΔpCO2 variability with mixed layer depth. Summer pCO2 variability is consistent with chlorophyll a variability, where higher concentrations of chlorophyll a correspond with lower pCO2 concentrations. In regions of low chlorophyll a concentrations, wind stress and sea surface temperature emerged as stronger drivers of ΔpCO2. In summary we propose that sub-decadal variability is explained by summer drivers, while winter variability contributes to the long-term changes associated with the SAM. This approach is a useful framework to assess the drivers of ΔpCO2 but would greatly benefit from improved estimates of ΔpCO2 and a longer time series.
On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?
NASA Astrophysics Data System (ADS)
Couldrey, Matthew; Oliver, Kevin; Yool, Andrew; Halloran, Paul; Achterberg, Eric
2016-04-01
The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2concentration gradient, ΔpCO2, and the temperature and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2and k both contribute significantly to interannual F variability, but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here, we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of non-seasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer term flux variability.
On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?
NASA Astrophysics Data System (ADS)
Couldrey, Matthew P.; Oliver, Kevin I. C.; Yool, Andrew; Halloran, Paul R.; Achterberg, Eric P.
2016-05-01
The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2 concentration gradient, ΔpCO2, and the temperature- and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2 and k both contribute significantly to interannual F variability but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2, and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2 and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of nonseasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer-term flux variability.
On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?
NASA Astrophysics Data System (ADS)
Couldrey, M.; Oliver, K. I. C.; Yool, A.; Halloran, P. R.; Achterberg, E. P.
2016-02-01
The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2 concentration gradient, ΔpCO2, and the temperature and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2 and k both contribute significantly to interannual F variability, but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here, we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2 and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2 and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of non-seasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer term flux variability.
A comparative modeling analysis of multiscale temporal variability of rainfall in Australia
NASA Astrophysics Data System (ADS)
Samuel, Jos M.; Sivapalan, Murugesu
2008-07-01
The effects of long-term natural climate variability and human-induced climate change on rainfall variability have become the focus of much concern and recent research efforts. In this paper, we present the results of a comparative analysis of observed multiscale temporal variability of rainfall in the Perth, Newcastle, and Darwin regions of Australia. This empirical and stochastic modeling analysis explores multiscale rainfall variability, i.e., ranging from short to long term, including within-storm patterns, and intra-annual, interannual, and interdecadal variabilities, using data taken from each of these regions. The analyses investigated how storm durations, interstorm periods, and average storm rainfall intensities differ for different climate states and demonstrated significant differences in this regard between the three selected regions. In Perth, the average storm intensity is stronger during La Niña years than during El Niño years, whereas in Newcastle and Darwin storm duration is longer during La Niña years. Increase of either storm duration or average storm intensity is the cause of higher average annual rainfall during La Niña years as compared to El Niño years. On the other hand, within-storm variability does not differ significantly between different ENSO states in all three locations. In the case of long-term rainfall variability, the statistical analyses indicated that in Newcastle the long-term rainfall pattern reflects the variability of the Interdecadal Pacific Oscillation (IPO) index, whereas in Perth and Darwin the long-term variability exhibits a step change in average annual rainfall (up in Darwin and down in Perth) which occurred around 1970. The step changes in Perth and Darwin and the switch in IPO states in Newcastle manifested differently in the three study regions in terms of changes in the annual number of rainy days or the average daily rainfall intensity or both. On the basis of these empirical data analyses, a stochastic rainfall time series model was developed that incorporates the entire range of multiscale variabilities observed in each region, including within-storm, intra-annual, interannual, and interdecadal variability. Such ability to characterize, model, and synthetically generate realistic time series of rainfall intensities is essential for addressing many hydrological problems, including estimation of flood and drought frequencies, pesticide risk assessment, and landslide frequencies.
Scale-dependent temporal variations in stream water geochemistry.
Nagorski, Sonia A; Moore, Iohnnie N; McKinnon, Temple E; Smith, David B
2003-03-01
A year-long study of four western Montana streams (two impacted by mining and two "pristine") evaluated surface water geochemical dynamics on various time scales (monthly, daily, and bi-hourly). Monthly changes were dominated by snowmelt and precipitation dynamics. On the daily scale, post-rain surges in some solute and particulate concentrations were similar to those of early spring runoff flushing characteristics on the monthly scale. On the bi-hourly scale, we observed diel (diurnal-nocturnal) cycling for pH, dissolved oxygen, water temperature, dissolved inorganic carbon, total suspended sediment, and some total recoverable metals at some or all sites. A comparison of the cumulative geochemical variability within each of the temporal groups reveals that for many water quality parameters there were large overlaps of concentration ranges among groups. We found that short-term (daily and bi-hourly) variations of some geochemical parameters covered large proportions of the variations found on a much longer term (monthly) time scale. These results show the importance of nesting short-term studies within long-term geochemical study designs to separate signals of environmental change from natural variability.
Scale-dependent temporal variations in stream water geochemistry
Nagorski, S.A.; Moore, J.N.; McKinnon, Temple E.; Smith, D.B.
2003-01-01
A year-long study of four western Montana streams (two impacted by mining and two "pristine") evaluated surface water geochemical dynamics on various time scales (monthly, daily, and bi-hourly). Monthly changes were dominated by snowmelt and precipitation dynamics. On the daily scale, post-rain surges in some solute and particulate concentrations were similar to those of early spring runoff flushing characteristics on the monthly scale. On the bi-hourly scale, we observed diel (diurnal-nocturnal) cycling for pH, dissolved oxygen, water temperature, dissolved inorganic carbon, total suspended sediment, and some total recoverable metals at some or all sites. A comparison of the cumulative geochemical variability within each of the temporal groups reveals that for many water quality parameters there were large overlaps of concentration ranges among groups. We found that short-term (daily and bi-hourly) variations of some geochemical parameters covered large proportions of the variations found on a much longer term (monthly) time scale. These results show the importance of nesting short-term studies within long-term geochemical study designs to separate signals of environmental change from natural variability.
NASA Astrophysics Data System (ADS)
Yoon, J.; Zeng, N.; Mariotti, A.; Swenson, S.
2007-12-01
In an approach termed the P-E-R (or simply PER) method, we apply the basin water budget equation to diagnose the long-term variability of the total terrestrial water storage (TWS). The key input variables are observed precipitation (P) and runoff (R), and estimated evaporation (E). Unlike typical offline land-surface model estimate where only atmospheric variables are used as input, the direct use of observed runoff in the PER method imposes an important constraint on the diagnosed TWS. Although there lack basin-scale observations of evaporation, the tendency of E to have significantly less variability than the difference between precipitation and runoff (P-R) minimizes the uncertainties originating from estimated evaporation. Compared to the more traditional method using atmospheric moisture convergence (MC) minus R (MCR method), the use of observed precipitation in PER method is expected to lead to general improvement, especially in regions atmospheric radiosonde data are too sparse to constrain the atmospheric model analyzed MC such as in the remote tropics. TWS was diagnosed using the PER method for the Amazon (1970-2006) and the Mississippi Basin (1928-2006), and compared with MCR method, land-surface model and reanalyses, and NASA's GRACE satellite gravity data. The seasonal cycle of diagnosed TWS over the Amazon is about 300 mm. The interannual TWS variability in these two basins are 100-200 mm, but multi-dacadal changes can be as large as 600-800 mm. Major droughts such as the Dust Bowl period had large impact with water storage depleted by 500 mm over a decade. Within the short period 2003-2006 when GRACE data was available, PER and GRACE show good agreement both for seasonal cycle and interannual variability, providing potential to cross-validate each other. In contrast, land-surface model results are significantly smaller than PER and GRACE, especially towards longer timescales. While we currently lack independent means to verify these long-term changes, simple error analysis using 3 precipitation datasets and 3 evaporation estimates suggest that the multi-decadal amplitude can be uncertain up to a factor of 2, while the agreement is high on interannual timescales. The large TWS variability implies the remarkable capacity of land-surface in storing and taking up water that may be under-represented in models. The results also suggest the existence of water storage memories on multi-year time scales, significantly longer than typically assumed seasonal timescales associated with surface soil moisture.
Relapse May Serve as a Mediator Variable in Longitudinal Outcomes in Multiple Sclerosis.
Stone, Lael Anne; Cutter, Gary Raymond; Fisher, Elizabeth; Richert, Nancy; McCartin, Jennifer; Ohayon, Joan; Bash, Craig; McFarland, Henry
2016-05-01
Contrast-enhancing lesions (CEL) on magnetic resonance imaging (MRI) are believed to represent inflammatory disease activity in multiple sclerosis (MS), but their relationship to subsequent long-term disability and progression is unclear, particularly at longer time periods such as 8-10 years. Between 1989 and 1994, 111 MS patients were seen at the National Institutes of Health for clinical evaluations and 3 monthly contrast-enhanced MRI scans. Of these, 94 patients were re-evaluated a mean of 8 years later (range 6.1-10.5 years) with a single MRI scan and clinical evaluation. CEL number and volume were determined at baseline and follow-up. The number of relapses was ascertained over the follow-up period and annualized relapse rates were calculated. Other MRI parameters, such as T2 hyperintensity volume, T1 volume, and brain parenchymal fraction, were also calculated. While there was no direct correlation between CEL number or volume at baseline and disability status at follow-up, CEL measures at baseline did correlate with number of relapses observed in the subsequent years, and the number of relapses in turn correlated with subsequent disability as well as transition to progressive MS. While number and volume of CEL at baseline do not directly correlate with disability in the longer term in MS, our data suggest that 1 route to disability involves relapses as a mediator variable in the causal sequence of MS progression from CEL to disability. Further studies using relapse as a mediator variable in a larger data set may be warranted. Copyright © 2015 by the American Society of Neuroimaging.
May duration of untreated illness influence the long-term course of major depressive disorder?
Altamura, A Carlo; Dell'osso, Bernardo; Vismara, Serena; Mundo, Emanuela
2008-03-01
The aim of this naturalistic study was to investigate the possible influence of the duration of untreated illness (DUI) on the long-term course of Major Depressive Disorder (MDD). One hundred and thirteen patients with recurrent MDD, according to DSM-IV-TR criteria, followed up for 5 years, were selected, interviewed and their clinical charts were reviewed. The DUI was defined as the interval between the onset of the first depressive episode and the first adequate antidepressant treatment. The sample was divided into two groups according to the DUI: one group with a DUI
Predictors of Full Enteral Feeding Achievement in Very Low Birth Weight Infants
Corvaglia, Luigi; Fantini, Maria Pia; Aceti, Arianna; Gibertoni, Dino; Rucci, Paola; Baronciani, Dante; Faldella, Giacomo
2014-01-01
Background To elucidate the role of prenatal, neonatal and early postnatal variables in influencing the achievement of full enteral feeding (FEF) in very low birth weight (VLBW) infants and to determine whether neonatal intensive care units (NICUs) differ in this outcome. Methods Population-based retrospective cohort study using data on 1,864 VLBW infants drawn from the “Emilia-Romagna Perinatal Network” Registry from 2004 to 2009. The outcome of interest was time to FEF achievement. Eleven prenatal, neonatal and early postnatal variables and the study NICUs were selected as potential predictors of time to FEF. Parametric survival analysis was used to model time to FEF as a function of the predictors. Marginal effects were used to obtain adjusted estimates of median time to FEF for specific subgroups of infants. Results Lower gestational age, exclusive formula feeding, higher CRIB II score, maternal hypertension, cesarean delivery, SGA and PDA predicted delayed FEF. NICUs proved to be heterogeneous in terms of FEF achievement. Newborns with PDA had a 4.2 days longer predicted median time to FEF compared to those without PDA; newborns exclusively formula-fed had a 1.4 days longer time to FEF compared to those fed human milk. Conclusions The results of our study suggest that time to FEF is influenced by clinical variables and NICU-specific practices. Knowledge of the variables associated with delayed/earlier FEF achievement could help in improving specific aspects of routine clinical management of VLBW infants and to reduce practice variability. PMID:24647523
NASA Technical Reports Server (NTRS)
Mann, Michael E.; Lall, Upmanu; Saltzman, Barry
1995-01-01
We demonstrate connections between decadal and secular global climatic variations, and historical variations in the volume of the Great Salt Lake. The decadal variations correspond to a low-frequency shifting of storm tracks which influence winter precipitation and explain nearly 18% of the interannual and longer-term variance in the record of monthly volume change. The secular trend accounts for a more modest approximately 1.5% of the variance.
Long Term Follow-up of Botulinum Toxin Therapy for Focal Hand Dystonia: Outcome at 10 or More Years
Lungu, Codrin; Karp, Barbara I; Alter, Katharine; Zolbrod, Regina; Hallett, Mark
2010-01-01
Background Prior studies have explored the efficacy and safety of BoNT treatment for FHD, but none have followed a large number of patients for 10 or more years. Methods Retrospective study, with benefit and weakness assessed on a 0-4 subjective scale. Demographic, clinical and treatment characteristics were analyzed using t-tests and Pearson correlations. Results 20 FHD patients had 10 years or longer treatment. Inter-injection intervals were variable. Musicians were more likely to wait longer between injections and had less complex dystonia. There was a trend for larger benefit in women and with shorter intervals. The dose increased over time. Dystonia characteristics did not predict response or side-effects, but benefit magnitude predicted longer compliance. No serious side-effects or antibody-mediated resistance occurred. Conclusion This is the longest reported period of BoNT treatment in the largest FHD cohort. BoNT therapy for FHD remains safe and effective after more than a decade of treatment. PMID:21506157
Bratton, Daniel J.; Craig, Sonya E.; Kohler, Malcolm; Stradling, John R.
2016-01-01
Background Long-term continuous positive airway pressure (CPAP) usage varies between individuals. It would be of value to be able to identify those who are likely to benefit from CPAP (and use it long term), versus those who would not, and might therefore benefit from additional help early on. First, we explored whether baseline characteristics predicted CPAP usage in minimally symptomatic obstructive sleep apnoea (OSA) patients, a group who would be expected to have low usage. Second, we explored if early CPAP usage was predictive of longer-term usage, as has been shown in more symptomatic OSA patients. Methods The MOSAIC trial was a multi-centre randomised controlled trial where minimally symptomatic OSA patients were randomised to CPAP, or standard care, for 6 months. Here we have studied only those patients randomised to CPAP treatment. Baseline characteristics including symptoms, questionnaires [including the Epworth sleepiness score (ESS)] and sleep study parameters were recorded. CPAP usage was recorded at 2–4 weeks after initiation and after 6 months. The correlation and association between baseline characteristics and 6 months CPAP usage was assessed, as was the correlation between 2 and 4 weeks CPAP usage and 6 months CPAP usage. Results One hundred and ninety-five patients randomised to CPAP therapy had median [interquartile range (IQR)] CPAP usage of 2:49 (0:44, 5:13) h:min/night (h/n) at the 2–4 weeks visit, and 2:17 (0:08, 4:54) h/n at the 6 months follow-up visit. Only male gender was associated with increased long-term CPAP use (male usage 2:56 h/n, female 1:57 h/n; P=0.02). There was a moderate correlation between the usage of CPAP at 2–4 weeks and 6 months, with about 50% of the variability in long-term use being predicted by the short-term use. Conclusions In patients with minimally symptomatic OSA, our study has shown that male gender (and not OSA severity or symptom burden) is associated with increased long-term use of CPAP at 6 months. Although, in general, early patterns of CPAP usage predicted longer term use, there are patients in whom this is not the case, and patients with low initial usage may need to extend their CPAP trial before a decision about longer-term use is made. PMID:26904268
Characterizing Uncertainty and Variability in PBPK Models ...
Mode-of-action based risk and safety assessments can rely upon tissue dosimetry estimates in animals and humans obtained from physiologically-based pharmacokinetic (PBPK) modeling. However, risk assessment also increasingly requires characterization of uncertainty and variability; such characterization for PBPK model predictions represents a continuing challenge to both modelers and users. Current practices show significant progress in specifying deterministic biological models and the non-deterministic (often statistical) models, estimating their parameters using diverse data sets from multiple sources, and using them to make predictions and characterize uncertainty and variability. The International Workshop on Uncertainty and Variability in PBPK Models, held Oct 31-Nov 2, 2006, sought to identify the state-of-the-science in this area and recommend priorities for research and changes in practice and implementation. For the short term, these include: (1) multidisciplinary teams to integrate deterministic and non-deterministic/statistical models; (2) broader use of sensitivity analyses, including for structural and global (rather than local) parameter changes; and (3) enhanced transparency and reproducibility through more complete documentation of the model structure(s) and parameter values, the results of sensitivity and other analyses, and supporting, discrepant, or excluded data. Longer-term needs include: (1) theoretic and practical methodological impro
Tropical rainforests dominate multi-decadal variability of the global carbon cycle
NASA Astrophysics Data System (ADS)
Zhang, X.; Wang, Y. P.; Peng, S.; Rayner, P. J.; Silver, J.; Ciais, P.; Piao, S.; Zhu, Z.; Lu, X.; Zheng, X.
2017-12-01
Recent studies find that inter-annual variability of global atmosphere-to-land CO2 uptake (NBP) is dominated by semi-arid ecosystems. However, the NBP variations at decadal to multi-decadal timescales are still not known. By developing a basic theory for the role of net primary production (NPP) and heterotrophic respiration (Rh) on NBP and applying it to 100-year simulations of terrestrial ecosystem models forced by observational climate, we find that tropical rainforests dominate the multi-decadal variability of global NBP (48%) rather than the semi-arid lands (35%). The NBP variation at inter-annual timescales is almost 90% contributed by NPP, but across longer timescales is progressively controlled by Rh that constitutes the response from the NPP-derived soil carbon input (40%) and the response of soil carbon turnover rates to climate variability (60%). The NBP variations of tropical rainforests is modulated by the ENSO and the PDO through their significant influences on temperature and precipitation at timescales of 2.5-7 and 25-50 years, respectively. This study highlights the importance of tropical rainforests on the multi-decadal variability of global carbon cycle, suggesting that we need to carefully differentiate the effect of NBP long-term fluctuations associated with ocean-related climate modes on the long-term trend in land sink.
Implications of longer term rest from grazing in the sagebrush steppe
K.W. Davies; M. Vavra; B. Schultz; N. Rimbey
2014-01-01
Longer term grazing rest has occurred or been proposed in large portions of the sagebrush steppe based on the assumption that it will improve ecosystem properties. However, information regarding the influence of longer term rest from grazing is limited and has not been summarized. We synthesized the scientific literature on long-term rest in the sagebrush steppe to...
Duration of untreated illness and suicide in bipolar disorder: a naturalistic study.
Altamura, A Carlo; Dell'Osso, Bernardo; Berlin, Heather A; Buoli, Massimiliano; Bassetti, Roberta; Mundo, Emanuela
2010-08-01
The aim of this naturalistic study was to evaluate the potential influence of the duration of untreated illness (DUI)--defined as the time elapsed between the occurrence of the first mood episode and the first adequate pharmacological treatment with mood stabilizers--on the clinical course of bipolar disorder (BD). Three hundred and twenty outpatients (n = 320) with a DSM-IV diagnosis of BD--either Type I or Type II--were interviewed; their clinical features were collected and they were naturalistically followed-up for 5 years. At the end of the follow-up observation, the sample was subdivided into two groups: one group with a DUI < or =2 years (n = 65) and another group with a DUI >2 years (n = 255). The main demographic and clinical variables were analyzed and compared between the two subgroups of patients using chi-square tests for dichotomous variables or Mann-Whitney U tests for continuous variables. Patients with a longer DUI showed a higher frequency of suicide attempts (Z = -2.11, P = 0.035), a higher number of suicide attempters (chi(2) = 4.13, df = 1, P = 0.04), and a longer duration of illness (Z = -6.79, P < 0.0001) when compared to patients with a shorter DUI. Moreover, patients with a longer DUI had a depressive first episode more frequently than patients with a shorter DUI (chi(2) = 11.28, df = 2, P = 0.004). A further analysis performed dividing the total sample into two subgroups on the basis of a DUI of 6 years (corresponding to the median value of the DUI in the study sample) confirmed prior findings. Results indicate a potential association between a longer DUI and a worse outcome in BD, particularly in terms of suicidality, and confirm the clinical relevance of early diagnosis and pharmacological intervention with mood stabilizers in BD.
Dell'Osso, Bernardo; Benatti, Beatrice; Buoli, Massimiliano; Altamura, A Carlo; Marazziti, Donatella; Hollander, Eric; Fineberg, Naomi; Stein, Dan J; Pallanti, Stefano; Nicolini, Humberto; Van Ameringen, Michael; Lochner, Christine; Hranov, Georgi; Karamustafalioglu, Oguz; Hranov, Luchezar; Menchon, Jose M; Zohar, Joseph
2013-08-01
Several studies reported a negative effect of early onset and long duration of illness on long-term outcome in psychiatric disorders, including Obsessive-Compulsive Disorder (OCD). OCD is a prevalent, comorbid and disabling condition, associated with reduced quality of life and overall well-being for affected patients and related caregivers. The present multicenter naturalistic study sought to assess the influence of early onset and duration of illness on long-term outcome in a sample of 376 OCD out-patients worldwide, as part of the "International College of Obsessive-Compulsive Spectrum Disorders" (ICOCS) network. Binary logistic regressions were performed with age at the onset and duration of illness, as continuous independent variables, on a series of different outcome dependent variables, including lifetime number of hospitalizations and suicide attempts, poly-therapy and psychiatric comorbidity. Correlations in terms of disability (SDS) were analyzed as well. Results showed that a longer duration of illness (but not earlier age of onset) was associated with hospitalization (odds ratio=1.03, p=0.01), earlier age at onset with CBT (odds ratio=0.94, p<0.001) and both a later age at onset (odds ratio=1.05, p=0.02) and a shorter duration of illness (odds ratio=0.93, p=0.02) with panic disorder comorbidity. In addition, earlier age at onset inversely correlated with higher social disability (r=-0.12, p=0.048) and longer duration of illness directly correlated with higher disability in work, social and family life (r=0.14, p=0.017; r=0.13, p=0.035; r=0.14, p=0.02). The findings from the present large, multicenter study indicate early onset and long duration of illness as overall negative predictors of long-term outcome in OCD. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.
Contrasting effects of climate on juvenile body size in a Southern Hemisphere passerine bird.
Kruuk, Loeske E B; Osmond, Helen L; Cockburn, Andrew
2015-08-01
Despite extensive research on the topic, it has been difficult to reach general conclusions as to the effects of climate change on morphology in wild animals: in particular, the effects of warming temperatures have been associated with increases, decreases or stasis in body size in different populations. Here, we use a fine-scale analysis of associations between weather and offspring body size in a long-term study of a wild passerine bird, the cooperatively breeding superb fairy-wren, in south-eastern Australia to show that such variation in the direction of associations occurs even within a population. Over the past 26 years, our study population has experienced increased temperatures, increased frequency of heatwaves and reduced rainfall - but the mean body mass of chicks has not changed. Despite the apparent stasis, mass was associated with weather across the previous year, but in multiple counteracting ways. Firstly, (i) chick mass was negatively associated with extremely recent heatwaves, but there also positive associations with (ii) higher maximum temperatures and (iii) higher rainfall, both occurring in a period prior to and during the nesting period, and finally (iv) a longer-term negative association with higher maximum temperatures following the previous breeding season. Our results illustrate how a morphological trait may be affected by both short- and long-term effects of the same weather variable at multiple times of the year and that these effects may act in different directions. We also show that climate within the relevant time windows may not be changing in the same way, such that overall long-term temporal trends in body size may be minimal. Such complexity means that analytical approaches that search for a single 'best' window for one particular weather variable may miss other relevant information, and is also likely to make analyses of phenotypic plasticity and prediction of longer-term population dynamics difficult. © 2015 John Wiley & Sons Ltd.
Immediate and Longer-Term Stressors and the Mental Health of Hurricane Ike Survivors
Lowe, Sarah R.; Tracy, Melissa; Cerdá, Magdalena; Norris, Fran H.; Galea, Sandro
2014-01-01
Previous research has documented that individuals exposed to more stressors during disasters and their immediate aftermath (immediate stressors) are at risk of experiencing longer-term postdisaster stressors. Longer-term stressors, in turn, have been found to play a key role in shaping postdisaster psychological functioning. Few studies have simultaneously explored the links from immediate to longer-term stressors, and from longer-term stressors to psychological functioning, however. Additionally, studies have inadequately explored whether postdisaster psychological symptoms influence longer-term stressors. In the current study, we aimed to fill these gaps. Participants (N = 448) were from population-based study of Hurricane Ike survivors and completed assessments 2–5 months (Wave 1), 5–9 months (Wave 2) and 14–18 months (Wave 3) postdisaster. Through path analysis, we found that immediate stressors, assessed at Wave 1, were positively associated with Wave 2 and Wave 3 stressors, which in turn were positively associated with Wave 2 and Wave 3 posttraumatic stress and depressive symptoms. Wave 2 posttraumatic stress symptoms were positively associated with Wave 3 stressors, and Wave 1 depressive symptoms were positively associated with Wave 2 stressors. The findings suggest that policies and interventions can reduce the impact of disasters on mental health by preventing and alleviating both immediate and longer-term postdisaster stressors. PMID:24343752
Edwards, Katherine; Jones, Natasha; Newton, Julia; Foster, Charlie; Judge, Andrew; Jackson, Kate; Arden, Nigel K; Pinedo-Villanueva, Rafael
2017-10-19
This descriptive review aimed to assess the characteristics and methodological quality of economic evaluations of cardiac rehabilitation (CR) programs according to updated economic guidelines for healthcare interventions. Recommendations will be made to inform future research addressing the impact of a physical exercise component on cost-effectiveness. Electronic databases were searched for economic evaluations of exercise-based CR programs published in English between 2000 and 2014. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement was used to review the methodological quality of included economic evaluations. Fifteen economic evaluations met the review inclusion criteria. Assessed study characteristics exhibited wide variability, particularly in their economic perspective, time horizon, setting, comparators and included costs, with significant heterogeneity in exercise dose across interventions. Ten evaluations were based on randomised controlled trials (RCTs) spanning 6-24 months but often with weak or inconclusive results; two were modelling studies; and the final three utilised longer time horizons of 3.5-5 years from which findings suggest that long-term exercise-based CR results in lower costs, reduced hospitalisations and a longer cumulative patient lifetime. None of the 15 articles met all the CHEERS quality criteria, with the majority either fully or partially meeting a selection of the assessed variables. Evidence exists supporting the cost-effectiveness of exercise-based CR for cardiovascular disease patients. However, variability in CR program delivery and weak consistency between study perspective and design limits study comparability and therefore the accumulation of evidence in support of a particular exercise regime. The generalisability of study findings was limited due to the exclusion of patients with comorbidities as would typically be found in a real-world setting. The use of longer time-horizons would be more comparable with a chronic condition and enable economic assessments of the long-term effects of CR. As none of the articles met recent reporting standards for the economic assessment of healthcare interventions, it is recommended that future studies adhere to such guidelines.
NASA Astrophysics Data System (ADS)
Garner, G.; Hannah, D. M.; Malcolm, I.; Sadler, J. P.
2012-12-01
Riparian forest is recognised as important for moderating stream temperature variability and has the potential to mitigate thermal extremes in a changing climate. Previous research on the heat exchanges controlling water column temperature has often been short-term or seasonally-constrained, with the few multi-year studies limited to a maximum of two years. This study advances previous work by providing a longer-term perspective which allows assessment of inter-annual variability in stream temperature, microclimate and heat exchange dynamics between a semi-natural woodland and a moorland (no trees) reach of the Girnock Burn, a tributary of the Scottish Dee. Automatic weather stations collected 15-minute data over seven consecutive years, which to our knowledge is a unique data set in providing the longest term perspective to date on stream temperature, microclimate and heat exchange processes. Results for spring-summer indicate that the presence of a riparian canopy has a consistent effect between years in reducing the magnitude and variability of mean daily water column temperature and daily net energy totals. Differences in the magnitude and variability in net energy fluxes between the study reaches were driven primarily by fluctuations in net radiation and latent heat fluxes in response to between- and within-year variability in growth of the riparian forest canopy at the forest and prevailing weather conditions at both the forest and moorland. This research provides new insights on the inter-annual variability of stream energy exchanges for moorland and forested reaches under a wide range of climatological and hydrological conditions. The findings therefore provide a more robust process basis for modelling the impact of changes in forest practice and climate change on river thermal dynamics.
[Changes in heart rate variability after myocardial infarction. Value of Poincareé's diagram].
Copie, X; Le Heuzey, J Y; Iliou, M C; Pousset, F; Lavergne, T; Guize, L
1995-11-01
The variability of the heart rate is reduced after myocardial infarction. It then progressively increases, to return to near normal values after several months. However, these changes in heart rate variability occur at the same time as slowing of the heart rate which makes interpretation difficult. Poincaré's diagram is constructed from a Holter recording plotting each RR interval against the preceding RR interval. The authors have developed a geometric approach to this diagram to evaluate parasympathetic tone for a given heart rate. By measuring the dispersion in height of the Poincaré's diagram, the authors evaluate the shor-term variability for a given RR interval. Two 24 hr Holter recordings were performed in 52 patients at one and two weeks after a myocardial infarction. The dispersion in the height of the Poincaré's diagrams was measured at the 10th, 25th, 50th, 75th and 90th percentiles of the total dispersion. The authors have shown an increase in the short-term variability of the shortest RR intervals (1th, 25th and 50th percentiles) which is not observed in the longer RR intervals (75th and 90th percentiles). In conclusion, theres is an increase in the heart rate variability at the shortest RR intervals. This suggests that the recovery of parasympathic tone after myocardial infarction occurs mainly at the fastest heart rates.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Yu-Han; Wang, Jun-Xian; Chen, Xiao-Yang
Quasars are variable on timescales from days to years in UV/optical and generally appear bluer while they brighten. The physics behind the variations in fluxes and colors remains unclear. Using Sloan Digital Sky Survey g- and r-band photometric monitoring data for quasars in Stripe 82, we find that although the flux variation amplitude increases with timescale, the color variability exhibits the opposite behavior. The color variability of quasars is prominent at timescales as short as ∼10 days, but gradually reduces toward timescales up to years. In other words, the variable emission at shorter timescales is bluer than that at longermore » timescales. This timescale dependence is clearly and consistently detected at all redshifts from z = 0 to 3.5; thus, it cannot be due to contamination to broadband photometry from emission lines that do not respond to fast continuum variations. The discovery directly rules out the possibility that simply attributes the color variability to contamination from a non-variable redder component such as the host galaxy. It cannot be interpreted as changes in global accretion rate either. The thermal accretion disk fluctuation model is favored in the sense that fluctuations in the inner, hotter region of the disk are responsible for short-term variations, while longer-term and stronger variations are expected from the larger and cooler disk region. An interesting implication is that one can use quasar variations at different timescales to probe disk emission at different radii.« less
Williams, Benjamin R; Lazic, Stanley E; Ogilvie, Robert D
2008-02-01
The aims of this study were (1) to characterise the extent and nature of disrupted sleep in individuals with long-term sleep complaints subsequent to mild traumatic brain injury (MTBI), and (2) to determine whether sleep disturbances in MTBI subjects were more characteristic of psychophysiological, psychiatric, or idiopathic insomnia. Nine MTBI patients (27.8 months post-injury; SD=15.5 months) and nine control subjects underwent polysomnographic testing and completed self-report questionnaires on sleep quality. Power spectral (FFT) analysis of the sleep onset period was conducted, with both the power and variability in power being quantified. Individuals with MTBI exhibited long-term sleep difficulties, along with various cognitive and affective abnormalities. The MTBI group had 4% less efficient sleep (p=0.019), shorter REM onset latencies (p=0.011), and longer sleep onset latencies, although the latter were highly variable in the MTBI group (F-test: p=0.012). FFT analysis revealed greater intra-subject variability in the MTBI group in sigma, theta, and delta power during the sleep onset period. MTBI patients with persistent sleep complaints differ significantly from controls on a number of electrophysiological outcomes, but could not be easily classified into existing insomnia subtypes. Sleep disturbances can persist well after the injury in a subset of patients with MTBI.
Baum, Charles L
2017-02-01
This study examines the effects of college on weight over much of the life cycle. I compare weights for college students with their weights before and after college and with the weights of noncollege peers using data from the National Longitudinal Survey of Youth (NLSY). I also examine the longer-term effects of college measured almost three decades later. I find that college freshmen gain substantially less than the 15 pounds rumored to be typical for freshmen. Using difference models, individual-specific fixed-effects models, and instrumental variables models to control for various sources of potential bias, I find that freshman year college attendance is estimated to cause only about a one-pound increase. Supplemental results show that those from lower socioeconomic backgrounds gain more weight during the freshman college year. Longer term, having a college education consistently decreases weight. These negative effects have faded over the last 20 years, and they diminish as respondents approach middle age. These trends are more prevalent for whites and Hispanics than for blacks.
Clustering approaches to improve the performance of low cost air pollution sensors.
Smith, Katie R; Edwards, Peter M; Evans, Mathew J; Lee, James D; Shaw, Marvin D; Squires, Freya; Wilde, Shona; Lewis, Alastair C
2017-08-24
Low cost air pollution sensors have substantial potential for atmospheric research and for the applied control of pollution in the urban environment, including more localized warnings to the public. The current generation of single-chemical gas sensors experience degrees of interference from other co-pollutants and have sensitivity to environmental factors such as temperature, wind speed and supply voltage. There are uncertainties introduced also because of sensor-to-sensor response variability, although this is less well reported. The sensitivity of Metal Oxide Sensors (MOS) to volatile organic compounds (VOCs) changed with relative humidity (RH) by up to a factor of five over the range of 19-90% RH and with an uncertainty in the correction of a factor of two at any given RH. The short-term (second to minute) stabilities of MOS and electrochemical CO sensor responses were reasonable. During more extended use, inter-sensor quantitative comparability was degraded due to unpredictable variability in individual sensor responses (to either measurand or interference or both) drifting over timescales of several hours to days. For timescales longer than a week identical sensors showed slow, often downwards, drifts in their responses which diverged across six CO sensors by up to 30% after two weeks. The measurement derived from the median sensor within clusters of 6, 8 and up to 21 sensors was evaluated against individual sensor performance and external reference values. The clustered approach maintained the cost competitiveness of a sensor device, but the median concentration from the ensemble of sensor signals largely eliminated the randomised hour-to-day response drift seen in individual sensors and excluded the effects of small numbers of poorly performing sensors that drifted significantly over longer time periods. The results demonstrate that for individual sensors to be optimally comparable to one another, and to reference instruments, they would likely require frequent calibration. The use of a cluster median value eliminates unpredictable medium term response changes, and other longer term outlier behaviours, extending the likely period needed between calibration and making a linear interpolation between calibrations more appropriate. Through the use of sensor clusters rather than individual sensors, existing low cost technologies could deliver significantly improved quality of observations.
Cook, Sharon A; Salmon, Peter; Hayes, Gemma; Byrne, Angela; Fisher, Peter L
2018-03-01
Why some people recover emotionally after diagnosis and treatment of cancer and others do not is poorly understood. To identify factors around the time of diagnosis that predict longer-term distress is a necessary step in developing interventions to reduce patients' vulnerability. This review identified the demographic, clinical, social, and psychological factors available at or within 3 months of diagnosis that are reliable predictors of emotional distress at least 12 months later. A systematic search of literature for prospective studies addressing our research question and predicting a range of distress outcomes was conducted. Thirty-nine papers (reporting 36 studies) were subjected to narrative synthesis of the evidence. There was no consistent evidence that demographic, clinical, or social factors reliably predicted longer-term distress. Of the psychological factors examined, only baseline distress (significant in 26 of 30 relevant papers; 24 of 28 studies) and neuroticism (significant in all 5 papers/studies that examined it) consistently predicted longer-term distress. The heterogeneity of included studies, particularly in populations studied and methodology, precluded meta-analytic techniques. This review supports current clinical guidance advising early assessment of distress as a marker of vulnerability to persistent problems. Additionally, neuroticism is also indicated as a useful marker of vulnerability. However, the review also highlights that more sophisticated research designs, capable of identifying the psychological processes that underlie the association between these marker variables and persistent distress, are needed before more effective early interventions can be developed. © 2018 The Authors. Psycho-Oncology Published by John Wiley & Sons Ltd.
Lorentzen, Steinar; Bakali, Jan Vegard; Hersoug, Anne Grete; Hagtvet, Knut A; Ruud, Torleif; Høglend, Per
2012-09-01
Little research has been done on therapeutic alliance in group psychotherapy, especially the impact of treatment duration and therapist professional characteristics. Therapeutic alliance was rated by patients on the Working Alliance Inventory-Short Form at three time points (sessions 3, 10 and 17) in a randomized controlled trial of short-term and long-term psychodynamic group psychotherapy. As predictors we selected therapist clinical experience and length of didactic training, which have demonstrated ambiguous results in previous research. Linear latent variable growth curve models (structural equation modeling) were developed for the three Working Alliance Inventory-Short Form subscales bond, task and goal. We found a significant variance in individual growth curves (intercepts and slopes) but no differential development due to group length. Longer therapist formal training had a negative impact on early values of subscale task in both treatments. There was an interaction between length of the therapists' clinical experience and group length on early bond, task and goal: therapists with longer clinical experience were rated lower on initial bond in the long-term group but less so in the short-term group. Longer clinical experience influenced initial task and goal positively in the short-term group but was unimportant for task or significantly negative for goal in the long-term group. There was no mean development of alliance, and group length did not differentially impact the alliance during 6 months. Early ratings of the three Working Alliance Inventory-Short Form subscales partly reflected different preparations of patients in the two group formats, partly therapist characteristics, but more research is needed to see how these aspects impact alliance development and outcome. Therapists should pay attention to all three aspects of the alliance, when they prepare patients for group therapy. In psychodynamic groups, length of therapy does not differentiate the overall level or the development of member-leader alliance. Within psychodynamic groups, each individual appear to have their unique perception of the member-leader alliance. Therapists with longer formal psychotherapy training may be less successful in establishing early agreement with patients on the tasks of psychodynamic group psychotherapy. Patients perceive a somewhat lower degree of early emotional bonding with the more clinically experienced therapists in long-term psychodynamics groups. Therapists with more clinical experience may contribute to a stronger degree of initial agreement with patients on the tasks and goals of short-term group psychotherapy. Copyright © 2011 John Wiley & Sons, Ltd.
Using a Bayesian network to predict barrier island geomorphologic characteristics
Gutierrez, Ben; Plant, Nathaniel G.; Thieler, E. Robert; Turecek, Aaron
2015-01-01
Quantifying geomorphic variability of coastal environments is important for understanding and describing the vulnerability of coastal topography, infrastructure, and ecosystems to future storms and sea level rise. Here we use a Bayesian network (BN) to test the importance of multiple interactions between barrier island geomorphic variables. This approach models complex interactions and handles uncertainty, which is intrinsic to future sea level rise, storminess, or anthropogenic processes (e.g., beach nourishment and other forms of coastal management). The BN was developed and tested at Assateague Island, Maryland/Virginia, USA, a barrier island with sufficient geomorphic and temporal variability to evaluate our approach. We tested the ability to predict dune height, beach width, and beach height variables using inputs that included longer-term, larger-scale, or external variables (historical shoreline change rates, distances to inlets, barrier width, mean barrier elevation, and anthropogenic modification). Data sets from three different years spanning nearly a decade sampled substantial temporal variability and serve as a proxy for analysis of future conditions. We show that distinct geomorphic conditions are associated with different long-term shoreline change rates and that the most skillful predictions of dune height, beach width, and beach height depend on including multiple input variables simultaneously. The predictive relationships are robust to variations in the amount of input data and to variations in model complexity. The resulting model can be used to evaluate scenarios related to coastal management plans and/or future scenarios where shoreline change rates may differ from those observed historically.
Feeding preterm infants after hospital discharge: growth and development at 18 months of age.
Cooke, R J; Embleton, N D; Griffin, I J; Wells, J C; McCormick, K P
2001-05-01
We have shown that preterm infants fed a preterm formula grow better than those fed a standard term infant formula after hospital discharge. The purpose of this follow-up study was to determine whether improved early growth was associated with later growth and development. Preterm infants (< or =1750 g birth weight, < or =34 wk gestation) were randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (discharge to term) and the term formula (term to 6 mo). Anthropometry was performed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI between boys fed the preterm formula and boys fed the term formula or between the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01), primarily reflecting lower scores in boys fed the term formula. Thus, early diet has long-term effects on growth but not development at 18 mo of age. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.
Long-term outcome of major depressive disorder in psychiatric patients is variable.
Holma, K Mikael; Holma, Irina A K; Melartin, Tarja K; Rytsälä, Heikki J; Isometsä, Erkki T
2008-02-01
The prevailing view of outcome of major depressive disorder (MDD), based on mostly inpatient cohorts sampled from tertiary centers, emphasizes chronicity and frequent recurrences. We investigated the long-term outcome of a regionally representative psychiatric MDD cohort comprising mainly outpatients. The Vantaa Depression Study included 163 patients with DSM-IV MDD (71.5% of those eligible) diagnosed using structured and semistructured interviews and followed up at 6 months, 18 months, and 5 years with a life chart between February 1, 1997, and April 30, 2004. The effects of comorbid disorders and other predictors on outcome were comprehensively investigated. Over the 5-year follow-up, 98.8% of patients achieved a symptom state below major depressive episode (MDE) criteria, and 88.4% reached full remission, with the median time to full remission being 11.0 months. Nearly one third (29.3%) had no recurrences, whereas 30.0% experienced 1, 12.9% experienced 2, and 27.9% experienced 3 or more recurrences. Preceding dysthymic disorder (p = .028), cluster C personality disorder (p = .041), and longer MDE duration prior to entry (p = .011) were the most significant predictors of longer time in achieving full remission. Severity of MDD and comorbidity, especially social phobia, predicted probability of, shorter time to, and number of recurrences. Previous literature on mostly inpatient MDD may have, by generalizing from patients with the most severe psychopathology, overemphasized chronicity of MDD. The long-term outcome of MDD in psychiatric care is variable, with about one tenth of patients having poor, one third having intermediate, and one half having favorable outcomes. In addition to known predictors, cluster C personality disorders and social phobia warrant further attention as predictors of MDD outcome among outpatients.
Mulder, R; Boden, J; Carter, J; Luty, S; Joyce, P
2017-10-01
Cognitive behaviour therapy (CBT) and interpersonal psychotherapy (IPT) are the most studied psychotherapies for treatment of depression, but they are rarely directly compared particularly over the longer term. This study compares the outcomes of patients treated with CBT and IPT over 10 months and tests whether there are differential or general predictors of outcome. A single centre randomised controlled trial (RCT) of depressed outpatients treated with weekly CBT or IPT sessions for 16 weeks and then 24 weeks of maintenance CBT or IPT. The principle outcome was depression severity measured using the MADRS. Pre-specified predictors of response were in four domains: demographic depression, characteristics, comorbidity and personality. Data were analysed over 16 weeks and 40 weeks using general linear mixed effects regression models. CBT was significantly more effective than IPT in reducing depressive symptoms over the 10 month study largely because it appeared to work more quickly. There were no differential predictors of response to CBT v. IPT at 16 weeks or 40 weeks. Personality variables were most strongly associated with overall outcome at both 16 weeks and 40 weeks. The number of personality disorder symptoms and lower self-directness and reward dependence scores were associated with poorer outcome for both CBT and IPT at 40 weeks. CBT and IPT are effective treatments for major depression over the longer term. CBT may work more quickly. Personality variables are the most relevant predictors of outcome.
Measurements of the Solar Spectral Irradiance Variability over Solar Cycles 21 to 24
NASA Astrophysics Data System (ADS)
Woods, T. N.
2017-12-01
The solar irradiance is the primary natural energy input into Earth's atmosphere and climate system. Understanding the long-term variations of the solar spectral irradiance (SSI) over time scales of the 11-year solar activity cycle and longer is critical for most Sun-climate research topics. There are satellite measurements of the SSI since the 1970s that contribute to understanding the solar cycle variability over Solar Cycles 21 to 24. A limiting factor for the accuracy of these results is the uncertainties for the instrument degradation corrections, for which there are fairly large corrections relative to the amount of solar cycle variability at some wavelengths. A summary of these satellite SSI measurements, which are primarily in the ultraviolet and only recently in the visible and near infrared, will be presented. Examining SSI trends using a new analysis technique is helping to identify some uncorrected instrumental trends, which once applied to the SSI trends has the potential to provide more accurate solar cycle variability results. This new technique examines the SSI trends at different levels of solar activity to provide long-term trends in a SSI record, and one of the most common components of these derived long-term trends is a downward trend that we attribute to being most likely from uncorrected instrument degradation. Examples of this analysis will be presented for some of the satellite SSI measurements to demonstrate this new technique and how it has potential to improve the understanding of solar cycle variability and to clarify the uncertainties of the trends.
Do GCM's predict the climate.... Or the low frequency weather?
NASA Astrophysics Data System (ADS)
Lovejoy, S.; Schertzer, D.; Varon, D.
2012-04-01
Over twenty-five years ago, a three-regime scaling model was proposed describing the statistical variability of the atmosphere over time scales ranging from weather scales out to ≈ 100 kyrs. Using modern in situ data reanalyses, monthly surface series (at 5ox5o), 8 "multiproxy" (yearly) series of the Northern hemisphere from 1500 - 1980, and GRIP and Vostok paleotemperatures at 5.2 and ≈ 100 year resolutions (over the past 91-420 kyrs), we refine the model and show how it can be understood with the help of new developments in nonlinear dynamics, especially multifractals and cascades. In a scaling range, mean fluctuations in state variables such as temperature ΔT vary in power law manners ≈ Δt**H the where Δt is the duration. At small (weather) scales the fluctuation exponents are generally H>0; they grow with scale (Δt). At longer scales Δt >τw (≈ 10 days) H changes sign, the fluctuations decrease with scale; this is the low variability, "low frequency weather" regime. In this regime, the spectrum is a relatively flat "plateau", it's variability is low, stable, corresponding to our usual idea of "long term weather statistics". Finally for longer times, Δt>τc ≈ 10 - 100 years, once again H>0, so that the variability increases with scale: the true climate regime. These scaling regimes allow us to objectively define the weather as fluctuations over periods <τw, to define "climate states" as fluctuations at scale τc and then "climate change" as the fluctuations at longer periods (Δt>τc). We show that the intermediate low frequency weather regime is the result of the weather regime undergoing a "dimensional transition": at temporal scales longer than the typical lifetime of planetary structures (τw), the spatial degrees of freedom are rapidly quenched so that only the temporal degrees of freedom are important. This low frequency weather regime has statistical properties well reproduced not only by stochastic cascade models of weather, but also by control runs (i.e. without climate forcing) of GCM based climate forecasting systems including those of the Institut Pierre Simon Laplace (Paris) and the Earth Forecasting System (Hamburg). In order for these systems to go beyond simply predicting low frequency weather i.e. in order for them to predict the climate, they need appropriate climate forcings and/ or new internal mechanisms of variability. Using statistical scaling techniques we examine the scale dependence of fluctuations from forced and unforced GCM outputs, including from the ECHO-G and EFS simulations in the Millenium climate reconstruction project and compare this with data, multiproxies and paleo data. Our general conclusion is that the models systematically underestimate the multidecadal, multicentennial scale variability.
Petit, Géraldine; Luminet, Olivier; Cordovil de Sousa Uva, Mariana; Zorbas, Alexis; Maurage, Pierre; de Timary, Philippe
2017-01-01
Objective There is a lack of consensus regarding the extent to which cognitive dysfunctions may recover upon cessation of alcohol intake by alcohol-dependents (AD), and the divergent findings are most likely due to methodological differences between the various studies. The present study was aimed at conducting a very strict longitudinal study of cognitive recovery in terms of assessment points, the duration of abstinence, control of age and duration of the addiction, and by use of individual analyses in addition to mean group comparisons. Our study further focused on the 2–3 week phase of alcohol detoxification that is already known to positively affect many biological, emotional, motivational, as well as neural variables, followed by longer-term therapies for which good cognitive functioning is needed. Methods 41 AD inpatients undergoing a detoxification program, and 41 matched controls, were evaluated twice in terms of five cognitive functions (i.e., short-term memory, working memory, inhibition, cognitive flexibility, and verbal fluency) within a three-week interval [on the first day (T1) and the 18th day (T2) of abstinence for AD patients]. Emotional (positive and negative affectivity and depression) and motivational (craving) variables were also measured at both evaluation times. Results Although verbal fluency, short-term memory, and cognitive flexibility did not appear to be affected, the patients exhibited impaired inhibition and working memory at T1. While no recovery of inhibition was found to occur, the average working memory performance of the patients was comparable to that of the controls at T2. Improvements in emotional and motivational dimensions were also observed, although they did not correlate with the ones in working memory. Individual analysis showed that not all participants were impaired or recover the same functions. Conclusions While inhibition deficits appear to persist after 18 days of detoxification, deficits in working memory, which is a central component of cognition, are greatly reduced after alcohol detoxification. Individual differences in the trajectory of recovery do arise however, and it might be worth implementing individual assessments of impaired functions at the end of the detoxification phase in order to maximize the chances of success in longer-term treatments and abstinence. PMID:28767647
Climate change and marine ecosystems (Invited)
NASA Astrophysics Data System (ADS)
Chavez, F.
2013-12-01
Impacts of climate variability on marine ecosystems are pervasive. Those associated with the interannual El Ni~no phenomena are the most studied and better understood. Longer term variations associated with the Atlantic Multidecadal Oscillation (AMO), the Pacific Decadal Oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO) have become more evident as the present-day instrumental record has increased in length. The biological (chlorophyll to fish) and chemical (nutrients, oxygen, carbon) consequences of these climate-driven variations are discussed with an emphasis on the eastern and equatorial Pacific. During warmer periods biological productivity in the eastern Pacific is reduced and larger mobile organisms dramatically change their abundance and/or geographic distributions. At the same time biological productivity in the western Pacific increases highlighting that present (and future) climate-driven changes in biological productivity and chemical distributions are not (and will not) be uniform. The presentation documents present day variations using global scale information from satellites and in situ databases, model simulations and data collected by intensive local time series. Paradoxically longer term changes associated with phenomena like the Little Ice Age (LIA), captured in the sedimentary record, do not seem to follow the same warm (poor), cold (productive) patterns in the eastern Pacific, in fact these are reversed. The presentation ends with speculation regarding long term changes associated with a warmer world.
The Longer School Day and Five Term Year in CTCs: Some Initial Observations.
ERIC Educational Resources Information Center
Hagedorn, Julia
To satisfy the requirements of the British national curriculum and to provide greater emphasis on the teaching of mathematics, science, and technology, city technical colleges (CTCs) have adopted a longer working week and, in several cases, a longer school year. This document examines outcomes of the longer school day and the five-term year, 4…
Penner, Louis A; Guevarra, Darwin A.; Harper, Felicity W. K.; Taub, Jeffrey; Phipps, Sean; Albrecht, Terrance L.; Kross, Ethan
2015-01-01
Pediatric cancer caregivers are typically present at their child’s frequent, invasive treatments, and such treatments elicit substantial distress. Yet, variability exists in how even the most anxious caregivers cope. Here we examined one potential source of this variability: caregivers’ tendencies to self-distance when reflecting on their feelings surrounding their child’s treatments. We measured caregivers’ self-distancing and trait anxiety at baseline, anticipatory anxiety during their child’s treatment procedures, and psychological distress and avoidance three months later. Self-distancing buffered high (but not low) trait anxious caregivers against short- and long-term distress without promoting avoidance. These findings held when controlling for other buffers, highlighting the unique benefits of self-distancing. These results identify a coping process that buffers vulnerable caregivers against a chronic life stressor while also demonstrating the ecological validly of laboratory research on self-distancing. Future research is needed to explicate causality and the cognitive and physiological processes that mediate these results. PMID:27617183
Landon, Matthew K.; Morita, Andrew Y.; Nawikas, Joseph M.; Christensen, Allen H.; Faunt, Claudia C.; Langenheim, Victoria E.
2015-11-24
On the basis of data from 33 wells, water levels mostly declined between the fall of 2006 and the fall of 2013; the median decline was 5.1 feet during this period, for a median rate of decline of about 0.7 feet/year. Based on data from 40 wells, water-level changes between fall 2004 and fall 2013 were variable in magnitude and trend, but had a median decline of 2.4 feet and a median rate of decline of about 0.3 feet/ year. These differences in apparent rates of groundwater-level change highlight the value of ongoing water-level measurements to distinguish decadal, or longer term, trends in groundwater storage often associated with climatic variability and trends. Fifty-four long-term hydrographs indicated the sensitivity of groundwater levels to climatic conditions; they also showed a general decline in water levels across the study area since 1986 and, in some cases, dating back to the 1950s.
Agulhas leakage dynamics affects decadal variability in Atlantic overturning circulation.
Biastoch, A; Böning, C W; Lutjeharms, J R E
2008-11-27
Predicting the evolution of climate over decadal timescales requires a quantitative understanding of the dynamics that govern the meridional overturning circulation (MOC). Comprehensive ocean measurement programmes aiming to monitor MOC variations have been established in the subtropical North Atlantic (RAPID, at latitude 26.5 degrees N, and MOVE, at latitude 16 degrees N) and show strong variability on intraseasonal to interannual timescales. Observational evidence of longer-term changes in MOC transport remains scarce, owing to infrequent sampling of transoceanic sections over past decades. Inferences based on long-term sea surface temperature records, however, supported by model simulations, suggest a variability with an amplitude of +/-1.5-3 Sv (1 Sv = 10(6) m(3) s(-1)) on decadal timescales in the subtropics. Such variability has been attributed to variations of deep water formation in the sub-arctic Atlantic, particularly the renewal rate of Labrador Sea Water. Here we present results from a model simulation that suggest an additional influence on decadal MOC variability having a Southern Hemisphere origin: dynamic signals originating in the Agulhas leakage region at the southern tip of Africa. These contribute a MOC signal in the tropical and subtropical North Atlantic that is of the same order of magnitude as the northern source. A complete rationalization of observed MOC changes therefore also requires consideration of signals arriving from the south.
Gross, T; Amsler, F
2016-11-01
Given the lack of data in the available literature, we were interested in the disability rate and corresponding insurance costs following multiple trauma in Switzerland. The possible impact of demographic, traumatic and hospital process factors as well as subjective and objective longer-term outcome variables on insurance data acquired were examined. Following multiple trauma the clinical and socioeconomic parameters in 145 survivors of working age were investigated over 2 and 4 years post-injury at a Swiss trauma center (University Hospital Basel). The correlation with the corresponding data provided by the largest Swiss accident insurance company (Suva, n = 63) was tested by univariate and multivariate analysis and patients insured at Suva were compared with those insured elsewhere (n = 82). The mean level of disability in this cohort of multiple trauma patients insured at Suva was 43 %. The insurer expected costs of more than 1 million Swiss Francs per multiply injured patient. In univariate analysis, only discrete correlations (maximum r = 0.37) were found with resulting disability, but significant correlations were found in subsequent multivariate testing most of all for age and the sequential organ failure assessment (SOFA 11 % and 15 % predictive capacity, p = 0.001; corrected R 2 = 0.26). Among variables of longer-term outcome the Euro Quality of Life Group health-related quality of life in five dimensions (EQ-5D) correlated almost as highly with the objective extent of disability as did the reduced capacity to work declared by the patients (0.64 and 0.7, respectively). The estimation of long-term disability following multiple trauma based on primary data following injury appears to be possible only to a limited extent. Given the clinical and socioeconomic relevance, comparable analyses are necessary by including all insurance providers involved.
NASA Astrophysics Data System (ADS)
Welch, D.; Henden, A.; Bell, T.; Suen, C.; Fare, I.; Sills, A.
2015-12-01
(Abstract only) The variable stars of globular clusters have played and continue to play a significant role in our understanding of certain classes of variable stars. Since all stars associated with a cluster have the same age, metallicity, distance and usually very similar (if not identical reddenings), such variables can produce uniquely powerful constraints on where certain types of pulsation behaviors are excited. Advanced amateur astronomers are increasingly well-positioned to provide long-term CCD monitoring of globular cluster variable star but are hampered by a long history of poor or inaccessible finder charts and coordinates. Many of variable-rich clusters have published photographic finder charts taken in relatively poor seeing with blue-sensitive photographic plates. While useful signal-to-noise ratios are relatively straightforward to achieve for RR Lyrae, Type 2 Cepheids, and red giant variables, correct identification remains a difficult issue—particularly when images are taken at V or longer wavelengths. We describe the project and report its progress using the OC61, TMO61, and SRO telescopes of AAVSOnet after the first year of image acquisition and demonstrate several of the data products being developed for globular cluster variables.
Long-term follow-up of botulinum toxin therapy for focal hand dystonia: outcome at 10 years or more.
Lungu, Codrin; Karp, Barbara I; Alter, Katharine; Zolbrod, Regina; Hallett, Mark
2011-03-01
Previous studies have explored the efficacy and safety of botulinum neurotoxin (BoNT) treatment for Focal hand dystonia (FHD), but none have followed a large number of patients for 10 years or more. Retrospective study, with benefit and weakness assessed on a 0 to 4 subjective scale. Demographic, clinical and treatment characteristics were analyzed using t tests and Pearson correlations. Twenty FHD patients had 10 years or longer treatment. Interinjection intervals were variable. Musicians were more likely to wait longer between injections and had less complex dystonia. There was a trend for larger benefit in women and with shorter intervals. The dose increased over time. Dystonia characteristics did not predict response or side-effects, but benefit magnitude predicted longer compliance. No serious side-effects or antibody-mediated resistance occurred. This is the longest reported period of BoNT treatment in the largest FHD cohort. BoNT therapy for FHD remains safe and effective after more than a decade of treatment. Copyright © 2011 Movement Disorder Society.
Temporal variation in pelagic food chain length in response to environmental change
Ruiz-Cooley, Rocio I.; Gerrodette, Tim; Fiedler, Paul C.; Chivers, Susan J.; Danil, Kerri; Ballance, Lisa T.
2017-01-01
Climate variability alters nitrogen cycling, primary productivity, and dissolved oxygen concentration in marine ecosystems. We examined the role of this variability (as measured by six variables) on food chain length (FCL) in the California Current (CC) by reconstructing a time series of amino acid–specific δ15N values derived from common dolphins, an apex pelagic predator, and using two FCL proxies. Strong declines in FCL were observed after the 1997–1999 El Niño Southern Oscillation (ENSO) event. Bayesian models revealed longer FCLs under intermediate conditions for surface temperature, chlorophyll concentration, multivariate ENSO index, and total plankton volume but not for hypoxic depth and nitrate concentration. Our results challenge the prevalent paradigm that suggested long-term stability in the food web structure in the CC and, instead, reveal that pelagic food webs respond strongly to disturbances associated with ENSO events, local oceanography, and ongoing changes in climate. PMID:29057322
Seasonal variability shapes resilience of small-scale fisheries in Baja California Sur, Mexico.
Pellowe, Kara E; Leslie, Heather M
2017-01-01
Small-scale fisheries are an important source of food and livelihoods to coastal communities around the world. Understanding the seasonality of fisheries catch and composition is crucial to fisheries management, particularly in the context of changing environmental and socioeconomic conditions. While seasonal variability directly impacts the lives of fishers, most fisheries studies focus on longer-term change. Here we examine seasonal variability in the small-scale fisheries of Baja California Sur, Mexico based on 13 years of government fisheries data. We investigate how four fisheries indicators with direct relevance to ecological resilience-magnitude and variance of landed fish biomass, taxon richness and the proportion of top-trophic-level taxa in total catch-vary within and among years and at multiple spatial scales. We find that these resilience indicators vary both seasonally and spatially. These results highlight the value of finer-scale monitoring and management, particularly for data-poor fisheries.
Seasonal variability shapes resilience of small-scale fisheries in Baja California Sur, Mexico
Leslie, Heather M.
2017-01-01
Small-scale fisheries are an important source of food and livelihoods to coastal communities around the world. Understanding the seasonality of fisheries catch and composition is crucial to fisheries management, particularly in the context of changing environmental and socioeconomic conditions. While seasonal variability directly impacts the lives of fishers, most fisheries studies focus on longer-term change. Here we examine seasonal variability in the small-scale fisheries of Baja California Sur, Mexico based on 13 years of government fisheries data. We investigate how four fisheries indicators with direct relevance to ecological resilience–magnitude and variance of landed fish biomass, taxon richness and the proportion of top-trophic-level taxa in total catch–vary within and among years and at multiple spatial scales. We find that these resilience indicators vary both seasonally and spatially. These results highlight the value of finer-scale monitoring and management, particularly for data-poor fisheries. PMID:28783740
Coordinated Multiwavelength Observations of PKS 0528+134 in Quiescence
NASA Astrophysics Data System (ADS)
Boettcher, Markus; Palma, N.
2011-01-01
We report results of an intensive multiwavelength campaign on the prominent high-redshift (z = 2.06) gamma-ray bright blazar PKS 0528+134 in September - October 2009. The campaign was centered on four 30 ksec pointings with XMM-Newton, supplemented with ground-based optical (MDM, Perkins) and radio (UMRAO, Medicina, Metsaehovi, Noto, SMA) observations as well as long-term X-ray monitoring with RXTE and gamma-ray monitoring by Fermi. We find significant variability on 1 day time scales in the optical regime, accompanied by a weak redder-when-brighter trend. X-ray variability is found on longer ( 1 week) time scales, while the Fermi light curve shows no evidence for variability, neither in flux nor spectral index. We constructed four simultaneous spectral energy distributions, which can all be fit satisfactorily with a one-zone leptonic jet model. This work was supported by NASA through XMM-Newton Guest Observer Grant NNX09AV45G.
Do GCM's Predict the Climate.... Or the Low Frequency Weather?
NASA Astrophysics Data System (ADS)
Lovejoy, S.; Varon, D.; Schertzer, D. J.
2011-12-01
Over twenty-five years ago, a three-regime scaling model was proposed describing the statistical variability of the atmosphere over time scales ranging from weather scales out to ≈ 100 kyrs. Using modern in situ data reanalyses, monthly surface series (at 5ox5o), 8 "multiproxy" (yearly) series of the Northern hemisphere from 1500- 1980, and GRIP and Vostok paleotemperatures at 5.2 and ≈ 100 year resolutions (over the past 91-420 kyrs), we refine the model and show how it can be understood with the help of new developments in nonlinear dynamics, especially multifractals and cascades. In a scaling range, mean fluctuations in state variables such as temperature ΔT ≈ ΔtH the where Δt is the duration. At small (weather) scales the fluctuation exponents are generally H>0; they grow with scale. At longer scales Δt >τw (≈ 10 days) they change sign, the fluctuations decrease with scale; this is the low variability, "low frequency weather" regime the spectrum is a relatively flat "plateau", it's variability is that of the usual idea of "long term weather statistics". Finally for longer times, Δt>τc ≈ 10 - 100 years, again H>0, the variability again increases with scale. This is the true climate regime. These scaling regimes allow us to objectively define the weather as fluctuations over periods <τw, "climate states", as fluctuations at scale τc and "climate change" as the fluctuations at longer periods >τc). We show that the intermediate regime is the result of the weather regime undergoing a "dimensional transition": at temporal scales longer than the typical lifetime of planetary structures (τw), the spatial degrees of freedom are rapidly quenched, only the temporal degrees of freedom are important. This low frequency weather regime has statistical properties well reproduced not only by weather cascade models, but also by control runs (i.e. without climate forcing) of GCM's (including IPSL and ECHAM GCM's). In order for GCM's to go beyond simply predicting this low frequency weather so as to predict the climate, they need appropriate climate forcings and/ or new internal mechanisms of variability. We examine this using wavelet analyses of forced and unforced GCM outputs, including the ECHO-G simulation used in the Millenium project. For example, we find that climate scenarios with large CO2 increases do give rise to a climate regime but that Hc>1 i.e. much larger than that of natural variability which for temperatures has Hc≈0.4. In comparison, the (largely volcanic) forcing of the ECHO-G Millenium simulation is fairly realistic (Hc≈0.4), although it is not clear that this mechanism can explain the even lower frequency variability found in the paleotemperature series, nor is it clear that this is compatible with low frequency solar or orbital forcings.
Hydrological conditions in the straits of the Ryukyu archipelago and adjacent basins
NASA Astrophysics Data System (ADS)
Moroz, V. V.; Bogdanov, K. T.
2007-10-01
The structure and dynamics of the water are studied on the basis of hydrological and meteorological long-term data combined with the materials of field observations over a period longer than half a century in the region of the Ryukyu archipelago. New data about the hydrological characteristics of the waters were obtained. Characteristic differences of waters of various modifications in the main straits between the islands are demonstrated. The dependence of the water structure formation in the straits on the seasonal variability of the water exchange through the straits is distinguished.
IRAS low resolution spectra of 26 symbiotic stars
NASA Technical Reports Server (NTRS)
Stencel, Robert E.; Brugel, Edward W.; Goodwill, Michael E.
1990-01-01
Data related to the spectral scans for 26 symbiotic stars are described which were extracted from the IRAS low resolution database. Data from the 8-15- and 15-23-micron bands are merged in a program that scales the longer wavelength and produces a weighted average of the spectral scans for each source. The survey shows that active dust producers can probably be isolated and some theories related to the presence of dust emission features are discussed in terms of source variability for measurements made with low resolution spectra.
Analyzing climate variations at multiple timescales can guide Zika virus response measures.
Muñoz, Ángel G; Thomson, Madeleine C; Goddard, Lisa; Aldighieri, Sylvain
2016-10-06
The emergence of Zika virus (ZIKV) in Latin America and the Caribbean in 2014-2016 occurred during a period of severe drought and unusually high temperatures, conditions that have been associated with the 2015-2016 El Niño event, and/or climate change; however, no quantitative assessment has been made to date. Analysis of related flaviviruses transmitted by the same vectors suggests that ZIKV dynamics are sensitive to climate seasonality and longer-term variability and trends. A better understanding of the climate conditions conducive to the 2014-2016 epidemic may permit the development of climate-informed short and long-term strategies for ZIKV prevention and control. Using a novel timescale-decomposition methodology, we demonstrate that the extreme climate anomalies observed in most parts of South America during the current epidemic are not caused exclusively by El Niño or climate change, but by a combination of climate signals acting at multiple timescales. In Brazil, the dry conditions present in 2013-2015 are primarily explained by year-to-year variability superimposed on decadal variability, but with little contribution of long-term trends. In contrast, the warm temperatures of 2014-2015 resulted from the compound effect of climate change, decadal and year-to-year climate variability. ZIKV response strategies made in Brazil during the drought concurrent with the 2015-2016 El Niño event, may require revision in light of the likely return of rainfall associated with the borderline La Niña event expected in 2016-2017. Temperatures are likely to remain warm given the importance of long term and decadal scale climate signals. The Author(s)
Madeleine, Pascal; Vangsgaard, Steffen; Hviid Andersen, Johan; Ge, Hong-You; Arendt-Nielsen, Lars
2013-08-01
Computer users often report musculoskeletal complaints and pain in the upper extremities and the neck-shoulder region. However, recent epidemiological studies do not report a relationship between the extent of computer use and work-related musculoskeletal disorders (WMSD).The aim of this study was to conduct an explorative analysis on short and long-term pain complaints and work-related variables in a cohort of Danish computer users. A structured web-based questionnaire including questions related to musculoskeletal pain, anthropometrics, work-related variables, work ability, productivity, health-related parameters, lifestyle variables as well as physical activity during leisure time was designed. Six hundred and ninety office workers completed the questionnaire responding to an announcement posted in a union magazine. The questionnaire outcomes, i.e., pain intensity, duration and locations as well as anthropometrics, work-related variables, work ability, productivity, and level of physical activity, were stratified by gender and correlations were obtained. Women reported higher pain intensity, longer pain duration as well as more locations with pain than men (P < 0.05). In parallel, women scored poorer work ability and ability to fulfil the requirements on productivity than men (P < 0.05). Strong positive correlations were found between pain intensity and pain duration for the forearm, elbow, neck and shoulder (P < 0.001). Moderate negative correlations were seen between pain intensity and work ability/productivity (P < 0.001). The present results provide new key information on pain characteristics in office workers. The differences in pain characteristics, i.e., higher intensity, longer duration and more pain locations as well as poorer work ability reported by women workers relate to their higher risk of contracting WMSD. Overall, this investigation confirmed the complex interplay between anthropometrics, work ability, productivity, and pain perception among computer users.
Lazy workers are necessary for long-term sustainability in insect societies
Hasegawa, Eisuke; Ishii, Yasunori; Tada, Koichiro; Kobayashi, Kazuya; Yoshimura, Jin
2016-01-01
Optimality theory predicts the maximization of productivity in social insect colonies, but many inactive workers are found in ant colonies. Indeed, the low short-term productivity of ant colonies is often the consequence of high variation among workers in the threshold to respond to task-related stimuli. Why is such an inefficient strategy among colonies maintained by natural selection? Here, we show that inactive workers are necessary for the long-term sustainability of a colony. Our simulation shows that colonies with variable thresholds persist longer than those with invariable thresholds because inactive workers perform the critical function of replacing active workers when they become fatigued. Evidence of the replacement of active workers by inactive workers has been found in ant colonies. Thus, the presence of inactive workers increases the long-term persistence of the colony at the expense of decreasing short-term productivity. Inactive workers may represent a bet-hedging strategy in response to environmental stochasticity. PMID:26880339
Global synthesis of long-term cloud condensation nuclei observations
NASA Astrophysics Data System (ADS)
Schmale, Julia; Henning, Silvia; Stratmann, Frank; Henzing, Bas; Schlag, Patrick; Aalto, Pasi; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Krüger, Mira; Jefferson, Anne; Whitehead, James; Carslaw, Ken; Yum, Seong Soo; Kristensson, Adam; Baltensperger, Urs; Gysel, Martin
2016-04-01
Cloud condensation nuclei (CCN) are aerosol particles with the ability to activate into droplets at a given super saturation and therefore influence the microphysical and optical properties of clouds. To predict cloud radiative properties understanding the spatial and temporal variability of CCN concentrations in different environments is important. However, currently, the effects of atmospheric particles on changes in cloud radiative forcing are still the largest contribution of uncertainty in climate forcing prediction (IPCC, 2013). Numerous intensive field campaigns have already explored detailed characteristics of CCN in many locations around the world. However, these rather short-term observations can generally not address seasonal or inter-annual variations and a comparison between campaign sites is difficult due to the higher influence of specific environmental circumstances on short-term measurements results. Here, we present results of more long-term CCN and aerosol number concentrations as well as size distribution data covering at least one full year between 2006 and 2014. The 12 locations include ACTRIS stations (http://www.actris.net/) in Europe, and further sites in North America, Brazil and Korea. The sites are located in different environments allowing for temporal and spatial characterization of CCN variability in different atmospheric regimes. Those include marine, remote-continental, boreal forest, rain forest, Arctic and monsoon-influenced environments, as well as boundary layer and free tropospheric conditions. The aerosol populations and their activation behavior show significant differences across the stations. While peak concentrations of CCN are observed in summer at the high altitude sites, in the Arctic the highest concentrations occur during the Haze period in spring. The rural-marine and rural-continental sites exhibit similar CCN concentration characteristics with a relatively flat annual cycle. At some stations, e.g. in the boreal environment, the annual cycle is more pronounced for higher SS. Geometric mean diameters of aerosol populations as well as the activation ratios on the basis of particles > 50 nm vary strongly among sites and throughout the seasons. Additionally, autocorrelation analysis is performed to investigate the persistence of variables over different timescales and to explore meaningful averaging periods for global modelling of CCN. In terms of CCN persistence, we find three different regimes: (1) CCN concentrations persist for a week or longer showing also seasonal patterns. (2) CCN concentrations persist for less than one week and there is little seasonal pattern. And (3) CCN concentrations are highly variable and do not persist longer than 2 days but show seasonal cycles. Several but not all sites show diurnal cycles. These different behaviors are influenced by environmental factors such as rainy seasons in the Amazon or Korea (monsoon) but also by anthropogenic pollution episodes such as during the Arctic Haze period.
Study protocol: The Improving Care of Acute Lung Injury Patients (ICAP) study
Needham, Dale M; Dennison, Cheryl R; Dowdy, David W; Mendez-Tellez, Pedro A; Ciesla, Nancy; Desai, Sanjay V; Sevransky, Jonathan; Shanholtz, Carl; Scharfstein, Daniel; Herridge, Margaret S; Pronovost, Peter J
2006-01-01
Introduction The short-term mortality benefit of lower tidal volume ventilation (LTVV) for patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) has been demonstrated in a large, multi-center randomized trial. However, the impact of LTVV and other critical care therapies on the longer-term outcomes of ALI/ARDS survivors remains uncertain. The Improving Care of ALI Patients (ICAP) study is a multi-site, prospective cohort study that aims to evaluate the longer-term outcomes of ALI/ARDS survivors with a particular focus on the effect of LTVV and other critical care therapies. Methods Consecutive mechanically ventilated ALI/ARDS patients from 11 intensive care units (ICUs) at four hospitals in the city of Baltimore, MD, USA, will be enrolled in a prospective cohort study. Exposures (patient-based, clinical management, and ICU organizational) will be comprehensively collected both at baseline and throughout patients' ICU stay. Outcomes, including mortality, organ impairment, functional status, and quality of life, will be assessed with the use of standardized surveys and testing at 3, 6, 12, and 24 months after ALI/ARDS diagnosis. A multi-faceted retention strategy will be used to minimize participant loss to follow-up. Results On the basis of the historical incidence of ALI/ARDS at the study sites, we expect to enroll 520 patients over two years. This projected sample size is more than double that of any published study of long-term outcomes in ALI/ARDS survivors, providing 86% power to detect a relative mortality hazard of 0.70 in patients receiving higher versus lower exposure to LTVV. The projected sample size also provides sufficient power to evaluate the association between a variety of other exposure and outcome variables, including quality of life. Conclusion The ICAP study is a novel, prospective cohort study that will build on previous critical care research to improve our understanding of the longer-term impact of ALI/ARDS, LTVV and other aspects of critical care management. Given the paucity of information about the impact of interventions on long-term outcomes for survivors of critical illness, this study can provide important information to inform clinical practice. PMID:16420652
Long-term Trends and Variability of Eddy Activities in the South China Sea
NASA Astrophysics Data System (ADS)
Zhang, M.; von Storch, H.
2017-12-01
For constructing empirical downscaling models and projecting possible future states of eddy activities in the South China Sea (SCS), long-term statistical characteristics of the SCS eddy are needed. We use a daily global eddy-resolving model product named STORM covering the period of 1950-2010. This simulation has employed the MPI-OM model with a mean horizontal resolution of 10km and been driven by the NCEP reanalysis-1 data set. An eddy detection and tracking algorithm operating on the gridded sea surface height anomaly (SSHA) fields was developed. A set of parameters for the criteria in the SCS are determined through sensitivity tests. Our method detected more than 6000 eddy tracks in the South China Sea. For all of them, eddy diameters, track length, eddy intensity, eddy lifetime and eddy frequency were determined. The long-term trends and variability of those properties also has been derived. Most of the eddies propagate westward. Nearly 100 eddies travel longer than 1000km, and over 800 eddies have a lifespan of more than 2 months. Furthermore, for building the statistical empirical model, the relationship between the SCS eddy statistics and the large-scale atmospheric and oceanic phenomena has been investigated.
NASA Astrophysics Data System (ADS)
Read, Katie A.; Lewis, Alastair C.; Salmon, Rhian A.; Jones, Anna E.; Bauguitte, Stéphane
2007-02-01
Measurements of C2-C8 non-methane hydrocarbons (NMHCs) have been made in situ at Halley Base, Antarctica (75°35'S, 26°19'W) from February 2004 to February 2005 as part of the Chemistry of the Antarctic Boundary Layer and the Interface with Snow (CHABLIS) experiment. The data show long- and short-term variabilities in NMHCs controlled by the seasonal and geographic dependence of emissions and variation in atmospheric removal rates and pathways. Ethane, propane, iso-butane, n-butane and acetylene abundances followed a general OH-dependent sinusoidal seasonal cycle. The yearly averages were 186, 31, 3.2, 4.9 and 19 pptV, respectively, lower than those which were reported in some previous studies. Superimposed on a seasonal cycle was shorter-term variability that could be attributed to both synoptic airmass variability and localized loss processes due to other radical species. Hydrocarbon variability during periods of hour-to-day-long surface O3 depletion in late winter/early spring indicated active halogen atom chemistry estimated to be in the range 1.7 × 103-3.4 × 104 atom cm-3 for Cl and 4.8 × 106-9.6 × 107 atom cm-3 for Br. Longer-term negative deviations from sinusoidal behaviour in the late August were indicative of NMHC reaction with a persistent [Cl] of 2.3 × 103 atom cm-3. Maximum ethene and propene of 157 and 179 pptV, respectively, were observed in the late February/early March, consistent with increased oceanic biogenic emissions; however, their presence was significant year-round (June-August concentrations of 17.1 +/- 18.3 and 7.9 +/- 20.0 pptV, respectively).
NASA Astrophysics Data System (ADS)
Hooke, Janet
2017-04-01
Flow and sediment processes in ephemeral channels are highly dynamic and spatially variable. The connectivity characteristics in a range of events are examined for several semi-arid catchments in Southeast Spain. Rainfall thresholds for runoff generation on slopes and for flow generation in channels have been identified at various scales. In many events, flow is not continuous down the channel system due partly to localised rainfall and to transmission losses but also to structural and morphological conditions. One extreme flow event with high sediment supply produced very high flow and sediment connectivity throughout the system. Results of spatial analysis of variation in hydraulics and sediment processes are presented and the effects are analysed. Amounts and locations of sediment storage were identified from repeat surveys. The overall contribution of such an event to morphological and sedimentological changes in the channel and longer-term landscape evolution is assessed. Land use and management are demonstrated to have a profound influence on the sediment delivery and connectivity functioning. The implications for land, channel and flood management in such an environment, together with the impacts of longer-term variations in flow regime due to land use and climate change, are considered.
NASA Astrophysics Data System (ADS)
Silins, U.; Emelko, M. B.; Bladon, K. D.; Stone, M.; Williams, C.; Martens, A. M.; Wagner, M. J.
2015-12-01
Biogeochemical processes reflecting interaction of vegetation and hydrology govern long-term export of nutrients such as nitrogen, phosphorus, and carbon over successional time scales. While management concepts of watershed "recovery" from disturbance back towards pre-disturbance conditions are often considered over much shorter timescales, few studies have directly explored watershed biogeochemical responses to disturbance long enough to directly document the longer-term trajectory of responses to severe land disturbance on nitrogen export. The objectives of this study were to document both the initial magnitude and patterns of longer-term recovery of stream nitrogen after the 2003 Lost Creek wildfire over nine years in front ranges of the Rocky Mountains in south-west Alberta, Canada. The study was conducted in seven instrumented catchments (4-14 km2), including burned, burned and salvage logged, and unburned (reference) conditions since 2004. Total nitrogen (TN) and nitrate (NO3-) concentrations and area-normalized yields were greater and more variable in burned and post-fire salvage logged catchments when compared with unburned catchments. Large initial increases in stream TN and NO3- production 1-3 years after both wildfire and post-fire salvage logging declined strongly to levels similar to, or below that of unburned watersheds 4-6 years after the fire, and continued to decline (although more slowly) 7-9 years after the wildfire. Post-fire salvage logging produced lower impacts on TN and NO3- in streams and these effects declined even more rapidly compared to the effects of wildfire alone. These changes closely corresponded to the early trajectory of establishment and rapid juvenile growth of post-fire regenerating forest vegetation in both catchment groups. While the concept of hydrologic recovery from disturbance is both a practical and meaningful concept for integrated landscape management for protection of forest water resources, the benchmark for "recovery" based on present conditions in undisturbed forests may vary widely depending on forest age and successional status.
Harmatz, Paul; Cattaneo, Federica; Ardigò, Diego; Geraci, Silvia; Hennermann, Julia B; Guffon, Nathalie; Lund, Allan; Hendriksz, Christian J; Borgwardt, Line
2018-06-01
Alpha-mannosidosis is an ultra-rare monogenic disorder resulting from a deficiency in the lysosomal enzyme alpha-mannosidase, with a prevalence estimated to be as low as 1:1,000,000 live births. The resulting accumulation of mannose-rich oligosaccharides in all tissues leads to a very heterogeneous disorder with a continuum of clinical manifestations with no distinctive phenotypes. Long-term enzyme replacement therapy (ERT) with velmanase alfa is approved in Europe for the treatment of non-neurological manifestations in patients with mild to moderate alpha-mannosidosis. The clinical heterogeneity and rarity of the disease limit the sensitivity of single parameters to detect clinically relevant treatment effects. Thus, we propose a novel multiple variable responder analysis to evaluate the efficacy of ERT for alpha-mannosidosis and present efficacy analyses for velmanase alfa using this method. Global treatment response to velmanase alfa (defined by response to ≥2 domains comprising pharmacodynamic, functional, and quality of life outcomes) was applied post hoc to data from the pivotal placebo-controlled rhLAMAN-05 study and to the longer-term integrated data from all patients in the clinical development program (rhLAMAN-10). After 12 months of treatment, a global treatment response was achieved by 87% of patients receiving velmanase alfa (n = 15) compared with 30% of patients receiving placebo (n = 10). Longer-term data from all patients in the clinical program (n = 33) showed 88% of patients were global responders, including all (100%) pediatric patients (n = 19) and the majority (71%) of adult patients (n = 14). The responder analysis model demonstrates a clinically meaningful treatment effect with velmanase alfa and supports the early initiation and continued benefit of longer-term treatment of all patients with alpha-mannosidosis with this ERT. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.
Reconstructed storm tracks reveal three centuries of changing moisture delivery to North America
Wise, Erika K.; Dannenberg, Matthew P.
2017-01-01
Moisture delivery to western North America is closely linked to variability in the westerly storm tracks of midlatitude cyclones, which are, in turn, modified by larger-scale features such as the El Niño–Southern Oscillation system. Instrumental and modeling data suggest that extratropical storm tracks may be intensifying and shifting poleward due to anthropogenic climate change, but it is difficult to separate recent trends from natural variability because of the large amount of decadal and longer variation in storm tracks and their limited instrumental record. We reconstruct cool-season, midlatitude Pacific storm-track position and intensity from 1693 to 1995 CE using existing tree-ring chronologies along with a network of newly developed chronologies from the U.S. Pacific Northwest, where small variations in storm-track position can have a major influence on hydroclimate patterns. Our results show high interannual-to-multidecadal variability in storm-track position and intensity over the past 303 years, with spectral signatures characteristic of tropical and northern Pacific influences. Comparison with reconstructions of precipitation and tropical sea surface temperature confirms the relationship between shifting drought patterns in the Pacific Northwest and storm-track variability through time and demonstrates the long-term influence of El Niño. These results allow us to place recent storm-track changes in the context of decadal and multidecadal fluctuations across the long-term record, showing that recent changes in storm-track intensity likely represent a warming-related increase amplified by natural decadal variability. PMID:28630900
Reconstructed storm tracks reveal three centuries of changing moisture delivery to North America.
Wise, Erika K; Dannenberg, Matthew P
2017-06-01
Moisture delivery to western North America is closely linked to variability in the westerly storm tracks of midlatitude cyclones, which are, in turn, modified by larger-scale features such as the El Niño-Southern Oscillation system. Instrumental and modeling data suggest that extratropical storm tracks may be intensifying and shifting poleward due to anthropogenic climate change, but it is difficult to separate recent trends from natural variability because of the large amount of decadal and longer variation in storm tracks and their limited instrumental record. We reconstruct cool-season, midlatitude Pacific storm-track position and intensity from 1693 to 1995 CE using existing tree-ring chronologies along with a network of newly developed chronologies from the U.S. Pacific Northwest, where small variations in storm-track position can have a major influence on hydroclimate patterns. Our results show high interannual-to-multidecadal variability in storm-track position and intensity over the past 303 years, with spectral signatures characteristic of tropical and northern Pacific influences. Comparison with reconstructions of precipitation and tropical sea surface temperature confirms the relationship between shifting drought patterns in the Pacific Northwest and storm-track variability through time and demonstrates the long-term influence of El Niño. These results allow us to place recent storm-track changes in the context of decadal and multidecadal fluctuations across the long-term record, showing that recent changes in storm-track intensity likely represent a warming-related increase amplified by natural decadal variability.
NASA Astrophysics Data System (ADS)
Gonsamo, Alemu; Chen, Jing M.; Shindell, Drew T.; Asner, Gregory P.
2016-08-01
A lack of long-term measurements across Earth's biological and physical systems has made observation-based detection and attribution of climate change impacts to anthropogenic forcing and natural variability difficult. Here we explore coherence among land, cryosphere and ocean responses to recent climate change using 3 decades (1980-2012) of observational satellite and field data throughout the Northern Hemisphere. Our results show coherent interannual variability among snow cover, spring phenology, solar radiation, Scandinavian Pattern, and North Atlantic Oscillation. The interannual variability of the atmospheric peak-to-trough CO2 amplitude is mostly impacted by temperature-mediated effects of El Niño/Southern Oscillation (ENSO) and Pacific/North American Pattern (PNA), whereas CO2 concentration is affected by Polar Pattern control on sea ice extent dynamics. This is assuming the trend in anthropogenic CO2 emission remains constant, or the interannual changes in the trends are negligible. Our analysis suggests that sea ice decline-related CO2 release may outweigh increased CO2 uptake through longer growing seasons and higher temperatures. The direct effects of variation in solar radiation and leading teleconnections, at least in part via their impacts on temperature, dominate the interannual variability of land, cryosphere and ocean indicators. Our results reveal a coherent long-term changes in multiple physical and biological systems that are consistent with anthropogenic forcing of Earth's climate and inconsistent with natural drivers.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Paap, Scott M.; West, Todd H.; Manley, Dawn Kataoka
2013-01-01
In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricitymore » demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.« less
Dolgoff-Kaspar, Rima; Baldwin, Ann; Johnson, Scott; Edling, Nancy; Sethi, Gulshan K
2012-01-01
Research shows that laughter has myriad health benefits, yet the medical community has not implemented it formally as a treatment. Patients awaiting organ transplantation have significant physical disabilities and are at risk for psychological distress. Attenuated heart rate variability (HRV) is a risk factor for a negative long-term outcome in some patients. The study intended to evaluate the clinical utility of laughter yoga in improving psychological and physiological measures in outpatients awaiting organ transplantation. Positive results would indicate promising areas to pursue in a follow-up study. Six participants met for 10 sessions over 4 weeks. The research team measured each participant's heart rate, HRV, blood pressure (BP), and immediate mood before and after the laughter and control interventions. The team assessed participants' longer-term mood (anxiety and depression) at the study's initiation, after a no-treatment control week, and at the end of the study. The study occurred at the Department of Surgery and Medicine at the University of Arizona Health Sciences Center, Tucson. Participants were patients awaiting transplants (three heart and three lung), two women and four men (ages 51-69 y). Participants had received no major surgery in the 3 months prior to the intervention, did not have a hernia or uncontrolled hypertension, and did not fall into the New York Heart Association function class 4. The 20-minute laughter intervention involved breathing and stretching exercises, simulated laughter (ie, unconditional laughter that is not contingent on the environment), chanting, clapping, and a meditation. The 20-minute control intervention involved the study's personnel discussing health and study-related topics with the participants. The research team measured BP, heart rate, and HRV and administered the Profile of Mood States, Beck Anxiety Inventory, and Beck Depression Inventory-II to evaluate immediate and longer-term mood. The team had planned quantitative statistical analysis of the data at the study's initiation but did not complete it because the number of enrolled participants was too low for the analysis to be meaningful. The team visually examined the data, however, for trends that would indicate areas to examine further in a follow-up study. Participants showed improved immediate mood (vigor-activity and friendliness) and increased HRV after the laughter intervention. Both the laughter and control interventions appeared to improve longer-term anxiety. Two participants awaiting a lung transplant dropped out of the study, and no adverse events occurred. This pilot study suggests that laughter yoga may improve HRV and some aspects of mood, and this topic warrants further research.
Dolgoff-Kaspar, Rima; Baldwin, Ann; Johnson, M Scott; Edling, Nancy; Sethi, Gulshan K
2012-01-01
Research shows that laughter has myriad health benefits, yet the medical community has not implemented it formally as a treatment. Patients awaiting organ transplantation have significant physical disabilities and are at risk for psychological distress. Attenuated heart rate variability (HRV) is a risk factor for a negative long-term outcome in some patients. The study intended to evaluate the clinical utility of laughter yoga in improving psychological and physiological measures in outpatients awaiting organ transplantation. Positive results would indicate promising areas to pursue in a follow-up study. Six participants met for 10 sessions over 4 weeks. The research team measured each participant's heart rate, HRV, blood pressure (BP), and immediate mood before and after the laughter and control interventions. The team assessed participants' longer-term mood (anxiety and depression) at the study's initiation, after a no-treatment control week, and at the end of the study. The study occurred at the Department of Surgery and Medicine at the University of Arizona Health Sciences Center, Tucson. Participants were patients awaiting transplants (three heart and three lung), two women and four men (ages 51-69 y). Participants had received no major surgery in the 3 months prior to the intervention, did not have a hernia or uncontrolled hypertension, and did not fall into the New York Heart Association function class 4. The 20-minute laughter intervention involved breathing and stretching exercises, simulated laughter (ie, unconditional laughter that is not contingent on the environment), chanting, clapping, and a meditation. The 20-minute control intervention involved the study's personnel discussing health and study-related topics with the participants. The research team measured BP, heart rate, and HRV and administered the Profile of Mood States, Beck Anxiety Inventory, and Beck Depression Inventory-II to evaluate immediate and longer-term mood. The team had planned quantitative statistical analysis of the data at the study's initiation but did not complete it because the number of enrolled participants was too low for the analysis to be meaningful. The team visually examined the data, however, for trends that would indicate areas to examine further in a follow-up study. Participants showed improved immediate mood (vigor-activity and friendliness) and increased HRV after the laughter intervention. Both the laughter and control interventions appeared to improve longer-term anxiety. Two participants awaiting a lung transplant dropped out of the study, and no adverse events occurred. This pilot study suggests that laughter yoga may improve HRV and some aspects of mood, and this topic warrants further research.
Moran, Lisa J; Noakes, Manny; Clifton, Peter M; Wittert, Gary A; Williams, Gemma; Norman, Robert J
2006-07-01
Polycystic ovary syndrome (PCOS), a common condition in women, improves with weight loss. Meal replacements in short-term weight loss and strategies for weight maintenance have not been investigated in PCOS. We compared in overweight women with PCOS the effects of meal replacements in short-term weight-loss and longer-term carbohydrate- or fat-restriction strategies on weight maintenance and improvements in reproductive and metabolic variables. Overweight women with PCOS (n = 43; x +/- SD age: 32.1 +/- 5.2 y; weight: 96.1 +/- 18.4 kg) followed an 8-wk weight-loss regimen (2 meal replacements/d, 4904.4 +/- 127 kJ; phase 1) and then a 6-mo weight-maintenance carbohydrate- (<120 g/d) or fat- (<50 g/d) restriction regimen (phase 2). Thirty-four women completed phase 1, and 23 women completed phase 2; the proportion of dropouts was similar in the 2 groups. During phase 1, significant (P < 0.05) reductions in weight (5.6 +/- 2.4 kg), waist circumference (6.1 +/- 2.5 cm), body fat (4.1 +/- 2.2 kg), insulin (2.8 +/- 1.1 mU/L), total testosterone (0.3 +/- 0.7 nmol/L), and free androgen index (3.1 +/- 4.6) occurred; these changes were sustained during phase 2. No significant differences between diet groups were seen for any variables. At 6 mo, both approaches resulted in a net weight loss of 4.7 +/- 4.6 kg. Improvements in menstrual cyclicity occurred for 16 (57.1%) of 28 subjects. Meal replacements are an effective strategy for the short-term management of PCOS. Advice on moderate fat or carbohydrate restriction was equally effective in maintaining weight reduction and improving reproductive and metabolic variables.
NASA Astrophysics Data System (ADS)
Wise, E.
2007-12-01
Much of the western United States is in the midst of a multi-year drought that has placed a renewed sense of urgency on water availability issues. The characterization of variability over relevant space and time scales has emerged as one of the top needs concerning the hydrological cycle, but understanding hydroclimatic variability at decadal and longer time scales has been limited by instrumental data that are both spatially and temporally inadequate. The reconstruction of moisture variables from tree-rings has been recognized as an important source of information on long-term water supply variability. Moisture variables of interest may include annual precipitation, snowpack, summer precipitation, and streamflow. Trees in closely co-located sites can vary widely in the signal they reflect, particularly in a region with the complex topography and hydroclimatic variability that is seen in the north-central Rocky Mountains. In this study, climatic and geospatial information was combined with tree-ring chronologies in order to better-understand factors determining variations in the response of tree growth to a particular precipitation signal. Resulting spatial variability in moisture seasonality and growth response provide insight into the region's moisture patterns and better characterization of the region's hydroclimatic variability.
NASA Astrophysics Data System (ADS)
Tissot, P.; Reisinger, A. S.; Besonen, M. R.
2017-12-01
While our understanding of global sea level rise and its budget has made great progress over the past decade, the spatial and temporal variability of relative sea level rise along the coasts still needs to be better understood and quantified. We developed a technique to reduce the confidence intervals associated with relative sea level rise (RSLR) estimates for 15 tide gauges located along the Texas coast for the period 1993-2016. Seasonally detrended monthly mean water levels are highly correlated after removal of station-specific RSLR trends, which allows for the quantification of a common, low frequency oceanic signal. RSLR confidence intervals are reduced from over 1.9 mm/yr, on average 2.3mm, to less than 1.1 mm/yr, on average 0.7 mm/yr after removing this common signal. The resulting RSLR rates range from 3.0 to 8.4 mm/yr. The range is wider than the longer-term rates of 5.3, 3.8 and 1.9 mm/yr measured from north to south by the three National Water Level Observation Network (NWLON) stations covering the study area (over different and longer time spans). The results emphasize the importance of the spatial variability of the vertical land motion component of RSLR. The temporal variability of the coherent oceanic signal is not significantly correlated to the ENSO signal for the study period and is only weakly correlated to the AMO and PDO climate indices. The coherence of the signal is further investigated by comparison with other locations along the Gulf of Mexico and along the Northeast Atlantic coast. The results are discussed while considering strong local processes along the Northwest Gulf of Mexico, such as wind forcing and intermittent eddies and the spatially broader influence of the Gulf Stream. The local significance of the RSLR spatial and temporal differences are discussed in terms of the differences in inundation frequency for nuisance type flooding including comparing the time span to reach a probability of at least one nuisance flood event per year.
Time-resolved multicolour photometry of bright B-type variable stars in Scorpius
NASA Astrophysics Data System (ADS)
Handler, G.; Schwarzenberg-Czerny, A.
2013-09-01
Context. The first two of a total of six nano-satellites that will constitute the BRITE-Constellation space photometry mission have recently been launched successfully. Aims: In preparation for this project, we carried out time-resolved colour photometry in a field that is an excellent candidate for BRITE measurements from space. Methods: We acquired 117 h of Strömgren uvy data during 19 nights. Our targets comprised the β Cephei stars κ and λ Sco, the eclipsing binary μ1 Sco, and the variable super/hypergiant ζ1 Sco. Results: For κ Sco, a photometric mode identification in combination with results from the spectroscopic literature suggests a dominant (l,m) = (1, -1) β Cephei-type pulsation mode of the primary star. The longer period of the star may be a rotational variation or a g-mode pulsation. For λ Sco, we recover the known dominant β Cephei pulsation, a longer-period variation, and observed part of an eclipse. Lack of ultraviolet data precludes mode identification for this star. We noticed that the spectroscopic orbital ephemeris of the closer pair in this triple system is inconsistent with eclipse timings and propose a refined value for the orbital period of the closer pair of 5.95189 ± 0.00003 d. We also argue that the components of the λ Sco system are some 30% more massive than previously thought. The binary light curve solution of μ1 Sco requires inclusion of the irradiation effect to explain the u light curve, and the system could show additional low amplitude variations on top of the orbital light changes. ζ1 Sco shows long-term variability on a time scale of at least two weeks that we prefer to interpret in terms of a variable wind or strange mode pulsations. Based on observations carried out at the South African Astronomical ObservatoryReduced time series for all stars are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/A1
NASA Astrophysics Data System (ADS)
Grossmann, I.
2013-12-01
Return periods of many extreme weather events are not stationary over time, given increasing risks due to global warming and multidecadal variability resulting from large scale climate patterns. This is problematic as extreme weather events and long-term climate risks such as droughts are typically conceptualized via measures such as return periods that implicitly assume non-stationarity. I briefly review these problems and present an application to the non-stationarity of droughts in the US Southwest. The US Southwest relies on annual precipitation maxima during winter and the North American Monsoon (NAM), both of which vary with large-scale climate patterns, in particular ENSO, the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). The latter two exhibit variability on longer (multi-decadal) time scales in addition to short-term variations. The region is also part of the subtropical belt projected to become more arid in a warming climate. The possible multidecadal impacts of the PDO on precipitation in the study region are analyzed with a focus on Arizona and New Mexico, using GPCC and CRU data since 1900. The projected impacts of the PDO on annual precipitation during the next three decades with GPCC data are similar in scale to the impacts of global warming on precipitation according to the A1B scenario and the CMIP2 multi-model means, while the combined impact of the PDO and AMO is about 19% larger. The effects according to the CRU dataset are about half as large as the projected global warming impacts. Given the magnitude of the projected impacts from both multidecadal variability and global warming, water management needs to explicitly incorporate both of these trends into long-term planning. Multi-decadal variability could be incorporated into the concept of return periods by presenting return periods as time-varying or as conditional on the respective 'phase' of relevant multidecadal patterns and on global warming. Problems in detecting the PDO signal and potential solutions are also discussed. We find that the long-term effect of the PDO can be more clearly separated from short-term variability by considering return periods of multi-year drought measures rather than return periods of simple drought measures that are more affected by short-term variations.
NASA Technical Reports Server (NTRS)
Fitzjerrell, D. G.; Grounds, D. J.; Leonard, J. I.
1975-01-01
Using a whole body algorithm simulation model, a wide variety and large number of stresses as well as different stress levels were simulated including environmental disturbances, metabolic changes, and special experimental situations. Simulation of short term stresses resulted in simultaneous and integrated responses from the cardiovascular, respiratory, and thermoregulatory subsystems and the accuracy of a large number of responding variables was verified. The capability of simulating significantly longer responses was demonstrated by validating a four week bed rest study. In this case, the long term subsystem model was found to reproduce many experimentally observed changes in circulatory dynamics, body fluid-electrolyte regulation, and renal function. The value of systems analysis and the selected design approach for developing a whole body algorithm was demonstrated.
The steady enhancement of the Australian Summer Monsoon in the last 200 years.
Gallego, David; García-Herrera, Ricardo; Peña-Ortiz, Cristina; Ribera, Pedro
2017-11-23
A new bicentennial series of the Australian monsoon strength based on historical wind observations has allowed for the assessment of the variability of this system since the early 19th century. Our series covers a period in which the scarcity of meteorological observations in the area had precluded the evaluation of long-term climatic trends. Results indicate that the increase in precipitation over Northern Australia reported for the last 60 years is just a manifestation of a much longer lasting trend related to the strengthening of the Australian monsoon that has been occurring since at least 1816.
Leaf dynamics in growth and reproduction of Xanthium canadense as influenced by stand density
Ogawa, Takahiro; Oikawa, Shimpei; Hirose, Tadaki
2015-01-01
Background and Aims Leaf longevity is controlled by the light gradient in the canopy and also by the nitrogen (N) sink strength in the plant. Stand density may influence leaf dynamics through its effects on light gradient and on plant growth and reproduction. This study tests the hypothesis that the control by the light gradient is manifested more in the vegetative period, whereas the opposite is true when the plant becomes reproductive and develops a strong N sink. Methods Stands of Xanthium canadense were established at two densities. Emergence, growth and death of every leaf on the main stem and branches, and plant growth and N uptake were determined from germination to full senescence. Mean residence time and dry mass productivity were calculated per leaf number, leaf area, leaf mass and leaf N (collectively termed ‘leaf variables’) in order to analyse leaf dynamics and its effect on plant growth. Key Results Branching and reproductive activities were higher at low than at high density. Overall there was no significant difference in mean residence time of leaf variables between the two stands. However, early leaf cohorts on the main stem had a longer retention time at low density, whereas later cohorts had a longer retention time at high density. Branch leaves emerged earlier and tended to live longer at low than at high density. Leaf efficiencies, defined as carbon export per unit investment of leaf variables, were higher at low density in all leaf variables except for leaf number. Conclusions In the vegetative phase of plant growth, the light gradient strongly controls leaf longevity, whereas later the effects of branching and reproductive activities become stronger and over-rule the effect of light environment. As leaf N supports photosynthesis and also works as an N source for plant development, N use is pivotal in linking leaf dynamics with plant growth and reproduction. PMID:26248476
Shared vision promotes family firm performance.
Neff, John E
2015-01-01
A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS), Role Clarity (RCL), Confidence in Management (CON), and Professional Networking (OLN) that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR), the functional integrity of the family itself, exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC) that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance.
Burggren, Warren
2018-05-10
The slow, inexorable rise in annual average global temperatures and acidification of the oceans are often advanced as consequences of global change. However, many environmental changes, especially those involving weather (as opposed to climate), are often stochastic, variable and extreme, particularly in temperate terrestrial or freshwater habitats. Moreover, few studies of animal and plant phenotypic plasticity employ realistic (i.e. short-term, stochastic) environmental change in their protocols. Here, I posit that the frequently abrupt environmental changes (days, weeks, months) accompanying much longer-term general climate change (e.g. global warming over decades or centuries) require consideration of the true nature of environmental change (as opposed to statistical means) coupled with an expansion of focus to consider developmental phenotypic plasticity. Such plasticity can be in multiple forms - obligatory/facultative, beneficial/deleterious - depending upon the degree and rate of environmental variability at specific points in organismal development. Essentially, adult phenotypic plasticity, as important as it is, will be irrelevant if developing offspring lack sufficient plasticity to create modified phenotypes necessary for survival. © 2018. Published by The Company of Biologists Ltd.
Predictability of a favorable outcome in anorexia nervosa.
Deter, H C; Schellberg, D; Köpp, W; Friederich, H C; Herzog, W
2005-03-01
In a long-term follow-up of anorexia nervosa (AN) patients, somatic, psychological and social variables at clinical presentation should be investigated using a multilevel approach. This study isolated predictors known from the literature over longer time periods and carried out a separate investigation of predictors in a sample of 81 AN patients of the Heidelberg-Mannheim study over a mean period of 12 years (range 9-19 years). Separate hierarchic regression analyses on the basis of the course of the Morgan-Russell categories were calculated for four individually recorded areas: anamnestic, psychological, somatic and social data sets. Age at the onset of the disease, purging behavior, low serum albumin, high glutamic-oxalo acetic transaminase (GOT) psychopathology (ANSS) and social pathology had the highest predictive value qualities. In survival analysis overall assessment of all six main predictors at clinical presentation could differentiate all patients who recovered from those who remained ill (log-rank test P = 0.019). A small number of variables were important for detecting a good or poor long-term course of AN. At onset of the disease, it seems necessary to evaluate these psychological, somatic and social predictors.
Shared vision promotes family firm performance
Neff, John E.
2015-01-01
A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS), Role Clarity (RCL), Confidence in Management (CON), and Professional Networking (OLN) that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR), the functional integrity of the family itself, exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC) that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance. PMID:26042075
NASA Astrophysics Data System (ADS)
Gourdji, S.; Zelaya Martinez, C.; Martinez Valle, A.; Mejia, O.; Laderach, P.; Lobell, D. B.
2013-12-01
Climate variability and change impact farmers at different timescales, but both are of concern for livelihoods and long-term viability of small farms in tropical, rain-fed agricultural systems. This study uses a historical dataset to analyze the impact of 40-year climate trends in Nicaragua on bean production, a staple crop that is an important source of calories and protein in the local diet, particularly in rural areas and in lower income classes. Bean yields are sensitive to rising temperatures, but also frequently limited by seasonal drought and low soil fertility. We use an empirical model to relate department-level yields to spatial variation and inter-annual fluctuations in historical precipitation, temperature and extreme rain events. We then use this model to quantify the impact on yields of long-term observed warming in day and night temperatures, increases in rainfall intensity, longer gaps between rain events, a shorter rainy season and overall drying in certain regions of the country. Preliminary results confirm the negative impacts of warming night temperatures, higher vapor pressure deficits, and longer gaps between rain events on bean yields, although some drying at harvest time has helped to reduce rotting. Across all bean-growing areas, these climate trends have led to a ~10% yield decline per decade relative to a stationary climate and production system, with this decline reaching up to ~20% in the dry northern highlands. In regions that have been particularly impacted by these trends, we look for evidence of farm abandonment, increases in off-farm employment, or on-farm adaptation solutions through crop diversification, use of drought or heat-tolerant seed, and adoption of rainwater harvesting. We will also repeat the modeling exercise for maize, another staple crop providing ~25% of daily calories at the national scale, but which is projected to be more resilient to climate trends.
NASA Astrophysics Data System (ADS)
Wang, Kaicun; Dickinson, Robert E.
2012-06-01
This review surveys the basic theories, observational methods, satellite algorithms, and land surface models for terrestrial evapotranspiration, E (or λE, i.e., latent heat flux), including a long-term variability and trends perspective. The basic theories used to estimate E are the Monin-Obukhov similarity theory (MOST), the Bowen ratio method, and the Penman-Monteith equation. The latter two theoretical expressions combine MOST with surface energy balance. Estimates of E can differ substantially between these three approaches because of their use of different input data. Surface and satellite-based measurement systems can provide accurate estimates of diurnal, daily, and annual variability of E. But their estimation of longer time variability is largely not established. A reasonable estimate of E as a global mean can be obtained from a surface water budget method, but its regional distribution is still rather uncertain. Current land surface models provide widely different ratios of the transpiration by vegetation to total E. This source of uncertainty therefore limits the capability of models to provide the sensitivities of E to precipitation deficits and land cover change.
Century long observation constrained global dynamic downscaling and hydrologic implication
NASA Astrophysics Data System (ADS)
Kim, H.; Yoshimura, K.; Chang, E.; Famiglietti, J. S.; Oki, T.
2012-12-01
It has been suggested that greenhouse gas induced warming climate causes the acceleration of large scale hydrologic cycles, and, indeed, many regions on the Earth have been suffered by hydrologic extremes getting more frequent. However, historical observations are not able to provide enough information in comprehensive manner to understand their long-term variability and/or global distributions. In this study, a century long high resolution global climate data is developed in order to break through existing limitations. 20th Century Reanalysis (20CR) which has relatively low spatial resolution (~2.0°) and longer term availability (140 years) is dynamically downscaled into global T248 (~0.5°) resolution using Experimental Climate Prediction Center (ECPC) Global Spectral Model (GSM) by spectral nudging data assimilation technique. Also, Global Precipitation Climatology Centre (GPCC) and Climate Research Unit (CRU) observational data are adopted to reduce model dependent uncertainty. Downscaled product successfully represents realistic geographical detail keeping low frequency signal in mean state and spatiotemporal variability, while previous bias correction method fails to reproduce high frequency variability. Newly developed data is used to investigate how long-term large scale terrestrial hydrologic cycles have been changed globally and how they have been interacted with various climate modes, such as El-Niño Southern Oscillation (ENSO) and Atlantic Multidecadal Oscillation (AMO). As a further application, it will be used to provide atmospheric boundary condition of multiple land surface models in the Global Soil Wetness Project Phase 3 (GSWP3).
Variability in Proactive and Reactive Cognitive Control Processes Across the Adult Lifespan
Karayanidis, Frini; Whitson, Lisa Rebecca; Heathcote, Andrew; Michie, Patricia T.
2011-01-01
Task-switching paradigms produce a highly consistent age-related increase in mixing cost [longer response time (RT) on repeat trials in mixed-task than single-task blocks] but a less consistent age effect on switch cost (longer RT on switch than repeat trials in mixed-task blocks). We use two approaches to examine the adult lifespan trajectory of control processes contributing to mixing cost and switch cost: latent variables derived from an evidence accumulation model of choice, and event-related potentials (ERP) that temporally differentiate proactive (cue-driven) and reactive (target-driven) control processes. Under highly practiced and prepared task conditions, aging was associated with increasing RT mixing cost but reducing RT switch cost. Both effects were largely due to the same cause: an age effect for mixed-repeat trials. In terms of latent variables, increasing age was associated with slower non-decision processes, slower rate of evidence accumulation about the target, and higher response criterion. Age effects on mixing costs were evident only on response criterion, the amount of evidence required to trigger a decision, whereas age effects on switch cost were present for all three latent variables. ERPs showed age-related increases in preparation for mixed-repeat trials, anticipatory attention, and post-target interference. Cue-locked ERPs that are linked to proactive control were associated with early emergence of age differences in response criterion. These results are consistent with age effects on strategic processes controlling decision caution. Consistent with an age-related decline in cognitive flexibility, younger adults flexibly adjusted response criterion from trial-to-trial on mixed-task blocks, whereas older adults maintained a high criterion for all trials. PMID:22073037
Breithaupt, Josh L.; Smoak, Joseph M.; Smith, Thomas J.; Sanders, Christian J.
2014-01-01
The objective of this research was to measure temporal variability in accretion and mass sedimentation rates (including organic carbon (OC), total nitrogen (TN), and total phosphorous (TP)) from the past century in a mangrove forest on the Shark River in Everglades National Park, USA. The 210Pb Constant Rate of Supply model was applied to six soil cores to calculate annual rates over the most recent 10, 50, and 100 year time spans. Our results show that rates integrated over longer timeframes are lower than those for shorter, recent periods of observation. Additionally, the substantial spatial variability between cores over the 10 year period is diminished over the 100 year record, raising two important implications. First, a multiple-decade assessment of soil accretion and OC burial provides a more conservative estimate and is likely to be most relevant for forecasting these rates relative to long-term processes of sea level rise and climate change mitigation. Second, a small number of sampling locations are better able to account for spatial variability over the longer periods than for the shorter periods. The site average 100 year OC burial rate, 123 ± 19 (standard deviation) g m-2yr-1, is low compared with global mangrove values. High TN and TP burial rates in recent decades may lead to increased soil carbon remineralization, contributing to the low carbon burial rates. Finally, the strong correlation between OC burial and accretion across this site signals the substantial contribution of OC to soil building in addition to the ecosystem service of CO2 sequestration.
[Functional impairment and quality of life after rectal cancer surgery].
Mora, Laura; Zarate, Alba; Serra-Aracil, Xavier; Pallisera, Anna; Serra, Sheila; Navarro-Soto, Salvador
2018-01-01
This study determines the quality of life and the anorectal function of these patients. Observational study of two cohorts comparing patients undergoing rectal tumor surgery using TaETM or conventional ETM after a minimum of six months of intestinal transit reconstruction. EORTC-30, EORTC-29 quality of life questionnaires and the anorectal function assessment questionnaire (LARS score) are applied. General variables are also collected. 31 patients between 2011 and 2014: 15 ETM group and 16 TaETM. We do not find statistically significant differences in quality of life questionnaires or in anorectal function. Statistically significant general variables: longer surgical time in the TaETM group. Nosocomial infection and minor suture failure in the TaETM group. The performance of TaETM achieves the same results in terms of quality of life and anorectal function as conventional ETM. Copyright: © 2018 Permanyer.
Ocean-atmosphere forcing of centennial hydroclimatic variability in the Pacific Northwest
Steinman, Byron A.; Abbott, Mark B.; Mann, Michael E.; Ortiz, Joseph D.; Feng, Song; Pompeani, David P.; Stansell, Nathan D.; Anderson, Lesleigh; Finney, Bruce P.; Bird, Broxton W.
2014-01-01
Reconstructing centennial timescale hydroclimate variability during the late Holocene is critically important for understanding large-scale patterns of drought and their relationship with climate dynamics. We present sediment oxygen isotope records spanning the last two millennia from 10 lakes, as well as climate model simulations, indicating that the Little Ice Age was dry relative to the Medieval Climate Anomaly in much of the Pacific Northwest of North America. This pattern is consistent with observed associations between the El Niño Southern Oscillation (ENSO), the Northern Annular Mode and drought as well as with proxy-based reconstructions of Pacific ocean-atmosphere variations over the past 1000 years. The large amplitude of centennial variability indicated by the lake data suggests that regional hydroclimate is characterized by longer-term shifts in ENSO-like dynamics, and that an improved understanding of the centennial timescale relationship between external forcing and drought conditions is necessary for projecting future hydroclimatic conditions in western North America.
Understanding Solar Cycle Variability
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de
The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to amore » generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.« less
Wiemers, Paul D; Marney, Lucy; White, Nicole; Bough, Georgina; Hustig, Alistair; Tan, Wei; Cheng, Ching-Siang; Kang, Dong; Yadav, Sumit; Tam, Robert; Fraser, John F
2018-04-24
There is a paucity of data in regards to longer term morbidity outcomes in Indigenous Australian patients undergoing coronary artery bypass grafting (CABG). No comparative data on re-infarction, stroke or reintervention rates exist. Outcome data following percutaneous coronary intervention (PCI) is also extremely limited. Addressing this gap in knowledge forms the major aim of our study. This was a single centre cohort study conducted at the Townsville Hospital, Australia which provides tertiary adult cardiac surgical services to the northern parts of the state of Queensland. It incorporated consecutive patients (n=350) undergoing isolated CABG procedures, 2008-2010, 20.9% (73/350) of whom were Indigenous Australians. The main outcome measures were major adverse cardiac or cerebrovascular events (MACCE) at mid-term follow-up (mean 38.9 months). The incidence of MACCE among Indigenous Australian patients was approximately twice that of non-Indigenous patients at mid-term follow-up (36.7% vs. 18.6%; p=0.005; OR 2.525 (1.291-4.880)). Following adjustment for preoperative and operative variables, Indigenous Australian status itself was not significantly associated with MACCE (AOR 1.578 (0.637-3.910)). Significant associations with MACCE included renal impairment (AOR 2.198 (1.010-4.783)) and moderate-severe left ventricular impairment (AOR 3.697 (1.820-7.508)). An association between diabetes and MACCE failed to reach statistical significance (AOR 1.812 (0.941-3.490)). Indigenous Australians undergoing CABG suffer an excess of MACCE when followed-up in the longer term. High rates of comorbidities in the Indigenous Australian population likely play an aetiological role. Copyright © 2018. Published by Elsevier B.V.
Impact of external forcing on simulated hydroclimate from interannual to multicentennial timescales
NASA Astrophysics Data System (ADS)
Roldán, Pedro; Fidel González-Rouco, Jesús; Melo-Aguilar, Camilo
2017-04-01
During the last millennium, external forcing experienced important changes in different timescales. It has been demostrated that these changes had an impact on climate. In particular, changes in solar activity, volcanic eruptions and emissions of greenhouse gases are related to short-term and long-term changes in global temperatures, with situations of higher total external forcing generally related with higher global and hemispherical temperatures, and conversely with situations of lower forcing. This connection is clearly observed in climate simulations from different models and in proxy-based reconstructions. The changes in external forcing can also explain certain changes in atmospheric dynamics and hydroclimate, although in this case it is in general more difficult to trace causality arguments. Analyses based on simulations from two different models (ECHO-G and CESM-LME) have been performed, to assess the impact of external forcing on climate in timescales ranging from interannual to multicentennial. Various climatic variables have been analysed, including temperature, sea level pressure, surface wind, precipitation and soil moisture. For interannual timescales, composites have been defined with the years before and after the main volcanic eruptions of the last millennium as well as the minima of solar activity during this period. For longer timescales, a Principal Component analysis has been performed, to try to separate the signal of external forcing from that of internal variability. This has been done for the whole millennium and for the pre-industrial period, to assess the difference between natural and anthropogenic forcing. For multicentennial timescales, composites for the Medieval Climate Anomaly (MCA; ca. 950-1250), the Little Ice Age (LIA; ca. 1450-1850) and the 20th Century have been compared. These three periods were respectively characterised by higher, lower and higher forcing. This allows to assess the contribution of external forcing to the evolution of climate over longer time intervals. These analyses have shown that external forcing is an important factor in the evolution of the simulated hydroclimate of the last millennium. In the short-term, it has been observed that volcanic eruptions and other situations of extreme forcing significantly alter the global precipitation in the subsequent years. In the long-term, variations of external forcing can be related to changes in atmospheric dynamics and in hydroclimate. However, this impact is not homogeneously distributed. There are areas where hydroclimate is mainly influenced by the external forcing and other areas more influenced by internal variability, with spatial decorrelation being higher in precipitation or drought related variables than in temperature. The regional sensitivity to external forcing of hydroclimate is model and, to a lesser degree, simulation dependent.
AGN Variability in the GOODS Fields
NASA Astrophysics Data System (ADS)
Sarajedini, Vicki
2007-07-01
Variability is a proven method to identify intrinsically faint active nuclei in galaxies found in deep HST surveys. We propose to extend our short-term variability study of the GOODS fields to include the more recent epochs obtained via supernovae searchers, increasing the overall time baseline from 6 months to 2.5 years. Based on typical AGN lightcurves, we expect to detect 70% more AGN by including these more recent epochs. Variable-detected AGN samples complement current X-ray and mid-IR surveys for AGN by providing unambigous evidence of nuclear activity. Additionallty, a significant number of variable nuclei are not associated with X-ray or mid-IR sources and would thus go undetected. With the increased time baseline, we will be able to construct the structure function {variability amplitude vs. time} for low-luminosity AGN to z 1. The inclusion of the longer time interval will allow for better descrimination among the various models describing the nature of AGN variability. The variability survey will be compared against spectroscopically selected AGN from the Team Keck Redshift Survey of the GOODS-N and the upcoming Flamingos-II NIR survey of the GOODS-S. The high-resolution ACS images will be used to separate the AGN from the host galaxy light and study the morphology, size and environment of the host galaxy. These studies will address questions concerning the nature of low-luminosity AGN evolution and variability at z 1.
AIRS Observations Based Evaluation of Relative Climate Feedback Strengths on a GCM Grid-Scale
NASA Astrophysics Data System (ADS)
Molnar, G. I.; Susskind, J.
2012-12-01
Climate feedback strengths, especially those associated with moist processes, still have a rather wide range in GCMs, the primary tools to predict future climate changes associated with man's ever increasing influences on our planet. Here, we make use of the first 10 years of AIRS observations to evaluate interrelationships/correlations of atmospheric moist parameter anomalies computed from AIRS Version 5 Level-3 products, and demonstrate their usefulness to assess relative feedback strengths. Although one may argue about the possible usability of shorter-term, observed climate parameter anomalies for estimating the strength of various (mostly moist processes related) feedbacks, recent works, in particular analyses by Dessler [2008, 2010], have demonstrated their usefulness in assessing global water vapor and cloud feedbacks. First, we create AIRS-observed monthly anomaly time-series (ATs) of outgoing longwave radiation, water vapor, clouds and temperature profile over a 10-year long (Sept. 2002 through Aug. 2012) period using 1x1 degree resolution (a common GCM grid-scale). Next, we evaluate the interrelationships of ATs of the above parameters with the corresponding 1x1 degree, as well as global surface temperature ATs. The latter provides insight comparable with more traditional climate feedback definitions (e. g., Zelinka and Hartmann, 2012) whilst the former is related to a new definition of "local (in surface temperature too) feedback strengths" on a GCM grid-scale. Comparing the correlation maps generated provides valuable new information on the spatial distribution of relative climate feedback strengths. We argue that for GCMs to be trusted for predicting longer-term climate variability, they should be able to reproduce these observed relationships/metrics as closely as possible. For this time period the main climate "forcing" was associated with the El Niño/La Niña variability (e. g., Dessler, 2010), so these assessments may not be descriptive of longer-term climate feedbacks due to global warming, for example. Nevertheless, one should take more confidence of greenhouse warming predictions of those GCMs that reproduce the (high quality observations-based) shorter-term feedback-relationships the best.
Violation of eating expectancies does not reduce conditioned desires for chocolate.
van den Akker, Karolien; van den Broek, Myrr; Havermans, Remco C; Jansen, Anita
2016-05-01
Although eating desires can be easily learned, their extinction appears more difficult. The present two-session study aimed to investigate the role of eating expectancies in the short and longer-term extinction of eating desires. In addition, the relationship between eating desires and conditioned evaluations was examined to test whether they might share a similar mechanism. It was hypothesized that the short-term extinction of eating desires would be more successful after the disconfirmation of eating expectancies (instructed extinction or IE), while resulting in worse longer-term extinction because omission of the food reward during extinction is not surprising. In contrast to the hypotheses, it was found that IE had no effect on the short-term and longer-term extinction of eating desires. Eating desires correlated with conditioned evaluations only to some extent. It is concluded that eating expectancies do not mediate the short-term extinction of conditioned eating desires. In addition, their longer-term extinction does not appear to be facilitated by a greater violation of eating expectancies. This suggests that it might not be necessary to focus on expectancy violation in cue exposure therapy to reduce eating desires. Copyright © 2016 Elsevier Ltd. All rights reserved.
Konstantinou, Nikos; Constantinidou, Fofi; Kanai, Ryota
2017-02-01
Working memory is responsible for keeping information in mind when it is no longer in view, linking perception with higher cognitive functions. Despite such crucial role, short-term maintenance of visual information is severely limited. Research suggests that capacity limits in visual short-term memory (VSTM) are correlated with sustained activity in distinct brain areas. Here, we investigated whether variability in the structure of the brain is reflected in individual differences of behavioral capacity estimates for spatial and object VSTM. Behavioral capacity estimates were calculated separately for spatial and object information using a novel adaptive staircase procedure and were found to be unrelated, supporting domain-specific VSTM capacity limits. Voxel-based morphometry (VBM) analyses revealed dissociable neuroanatomical correlates of spatial versus object VSTM. Interindividual variability in spatial VSTM was reflected in the gray matter density of the inferior parietal lobule. In contrast, object VSTM was reflected in the gray matter density of the left insula. These dissociable findings highlight the importance of considering domain-specific estimates of VSTM capacity and point to the crucial brain regions that limit VSTM capacity for different types of visual information. Hum Brain Mapp 38:767-778, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Campbell, David
2013-11-08
Non-contagious, chronic disease has been identified as a global health risk. Poor lifestyle choices, such as smoking, alcohol, drug and solvent abuse, physical inactivity, and unhealthy diet have been identified as important factors affecting the increasing incidence of chronic disease. The following focuses on the circumstance affecting the lifestyle or behavioral choices of Aboriginal and Torres Strait Islander peoples in remote-/very remote Australia. Poor behavioral choices are the result of endogenous characteristics that are influenced by a range of stressful exogenous variables making up the psychosocial determinants including social disenfranchisement, cultural loss, insurmountable tasks, the loss of volitional control and resource constraints. It is shown that poor behavioral choices can be economically rational; especially under highly stressful conditions. Stressful circumstances erode individual capacity to commit to long-term positive health alternatives such as self-investment in education. Policies directed at removing the impediments and providing incentives to behaviors involving better health choices can lead to reductions in smoking and alcohol consumption and improved health outcomes. Multijurisdictional culturally acceptable policies directed at distal variables relating to the psychosocial determinants of health and personal mastery and control can be cost effective. While the content of this paper is focused on the conditions of colonized peoples, it has broader relevance.
NASA Astrophysics Data System (ADS)
Torpin, Trevor; Boyd, Patricia T.; Smale, Alan P.
2015-01-01
The bright, unusual black-hole X-ray binary LMC X-3 has been monitored virtually continuously by the Japanese MAXI X-ray All-Sky Monitor aboard the International Space Station (Matsuoka, et al., PASJ, 2009) from August 2009 to the present. Comparison with RXTE PCA and ASM light curves during the ~2.33-year period of overlap demonstrate that despite slight differences in energy-band boundaries both the ASM and MAXI faithfully reproduce characteristics of the high-amplitude, nonperiodic long-term variability, on the order of 100-300 days, clearly seen in the more sensitive PCA monitoring. The mechanism for this variability at a timescale many times longer than the 1.7-day orbital period is still unknown. Models to explain the long-term variability invoke mechanisms such as changes in mass transfer rate, and/or a precessing warped accretion disk. Observations of LMC X-3 have not definitely determined whether wind accretion or Roche-love overflow is the driver of the long-term variability. Recent MAXI monitoring of LMC X-3 includes excellent coverage of a rare anomalous low state (ALS) where the X-ray source cannot be distinguished from the background, as well as several normal low states, in which the source count rate passes smoothly through a low, yet detectable value. Pointed Swift XRT and UVOT observations also sample this ALS and one normal low state well. We combine these data sets to study the correlations between the wavelength regimes observed during the ALS versus the normal low. We also examine the behavior of the X-ray hardness ratios using XRT and MAXI monitoring data during the ALS versus the normal low state.
Process connectivity reveals ecohydrologic sensitivity to drought and rainfall pulses
NASA Astrophysics Data System (ADS)
Goodwell, A. E.; Kumar, P.
2017-12-01
Ecohydrologic fluxes within atmosphere, canopy and soil systems exhibit complex and joint variability. This complexity arises from direct and indirect forcing and feedback interactions that can cause fluctuations to propagate between water, energy, and nutrient fluxes at various time scales. When an ecosystem is perturbed in the form of a single storm event, an accumulating drought, or changes in climate and land cover, this aspect of joint variability may dictate responsiveness and resilience of the entire system. A characterization of the time-dependent and multivariate connectivity between processes, fluxes, and states is necessary to identify and understand these aspects of ecohydrologic systems. We construct Temporal Information Partitioning Networks (TIPNets), based on information theory measures, to identify time-dependencies between variables measured at flux towers along elevation and climate gradients in relation to their responses to moisture-related perturbations. Along a flux tower transect in the Reynolds Creek Critical Zone Observatory (CZO) in Idaho, we detect a significant network response to a large 2015 dry season rainfall event that enhances microbial respiration and latent heat fluxes. At a transect in the Southern Sierra CZO in California, we explore network properties in relation to drought responses from 2011 to 2015. We find that both high and low elevation sites exhibit decreased connectivity between atmospheric and soil variables and latent heat fluxes, but the higher elevation site is less sensitive to this altered connectivity in terms of average monthly heat fluxes. Through a novel approach to gage the responsiveness of ecosystem fluxes to shifts in connectivity, this study aids our understanding of ecohydrologic sensitivity to short-term rainfall events and longer term droughts. This study is relevant to ecosystem resilience under a changing climate, and can lead to a greater understanding of shifting behaviors in many types of complex systems.
Global Scale Remote Sensing Monitoring of Endorheic Lake Systems
NASA Astrophysics Data System (ADS)
Scuderi, L. A.
2010-12-01
Semi-arid regions of the world contain thousands of endorheic lakes in large shallow basins. Due to their generally remote locations few are continuously monitored. Documentation of recent variability is essential to assessing how endorheic lakes respond to short-term meteorological conditions and longer-term decadal-scale climatic variability and is critical in determining future disturbance of hydrological regimes with respect to predicted warming and drying in the mid-latitudes. Short- and long-term departures from climatic averages, rapid environmental shifts and increased population pressures may result in significant fluctuations in the hydrologic budgets of these lakes and adversely impact endorheic lake/basin ecosystems. Information on flooding variability is also critical in estimating changes in P/E balances and on the production of exposed and easily deflated surfaces that may impact dust loading locally and regionally. In order to provide information on how these lakes respond we need to understand how entire systems respond hydrologically to different climatic inputs. This requires monitoring and analysis of regional to continental-scale systems. To date, this level of monitoring has not been achieved in an operational system. In order to assess the possibility of creating a global-scale lake inundation database we analyzed two contrasting lake systems in western North America (Mexico and New Mexico, USA) and China (Inner Mongolia). We asked two major questions: 1) is it possible to quickly and accurately quantify current lake inundation events in near real time using remote sensing? and, 2) is it possible to differentiate variable meteorological sources and resultant lake inundation responses using this type of database? With respect to these results we outline an automated lake monitoring approach using MODIS data and real-time processing systems that may provide future global monitoring capabilities.
Ayorech, Ziada; Tracy, Derek K; Baumeister, David; Giaroli, Giovanni
2015-03-15
Inflammation has emerged as a potentially important factor - and thus putative pharmacological target - in the pathology of bipolar disorders. However to date no systematic evaluations of the efficacy of add on anti-inflammatory treatment for the depressive and manic episodes have been carried out. Sixteen articles were ultimately identified - by computer searches of databases (including PsycINFO, MEDLINE, and EMBASE), supplemented by hand searches and personal communication - as meeting study inclusion criteria. Anti-manic effects were evaluated in two trials, one of adjunctive n-acetyl cysteine (NAC), one of omega-3 fatty acids (O3FA), and significant improvements only emerged for NAC. Celecoxib had a rapid but short-lived antidepressant effect. Despite limited effects of O3FA on symptoms, imaging data demonstrated alterations in neuronal functioning that might have longer-term therapeutic effects. Evidence was strongest for adjunctive NAC in bipolar depression though conclusions are limited by small sample sizes. Definitive conclusions are limited by the paucity of data, small study sizes, and the variability in methodology used. Current evidence for aspirin or celecoxib is insufficient though further investigation of the potential of celecoxib in early illness onset is warranted. Variable evidence exists for add-on O3FA though an indication of short-term treatment effects on membrane fluidity and neuronal activity suggest longer follow-up assessment is needed. The strongest evidence emerged for NAC in depression and future studies must address the role of illness duration and patients׳ baseline medications on outcomes. Careful consideration of lithium toxicity in the elderly and renal impaired is essential. Copyright © 2014 Elsevier B.V. All rights reserved.
Pteropods and climate off the Antarctic Peninsula
NASA Astrophysics Data System (ADS)
Loeb, Valerie J.; Santora, Jarrod A.
2013-09-01
Shelled (thecosome) and naked (gymnosome) pteropods are regular, at times abundant, members of Southern Ocean zooplankton assemblages. Regionally, shelled species can play a major role in food webs and carbon cycling. Because of their aragonite shells thecosome pteropods may be vulnerable to the impacts of ocean acidification; without shells they cannot survive and their demise would have major implications for food webs and carbon cycling in the Southern Ocean. Additionally, pteropod species in the southwest Atlantic sector of the Southern Ocean inhabit a region of rapid warming and climate change, the impacts of which are predicted to be observed as poleward distribution shifts. Here we provide baseline information on intraseasonal, interannual and longer scale variability of pteropod populations off the Antarctic Peninsula between 1994 and 2009. Concentrations of the 4 dominant taxa, Limacina helicina antarctica f. antarctica, Clio pyramidata f. sulcata, Spongiobranchaea australis and Clione limacina antarctica, are similar to those monitored during the 1928-1935 Discovery Investigations and reflect generally low values but with episodic interannual abundance peaks that, except for C. pyr. sulcata, are related to basin-scale climate forcing associated with the El Niño-Southern Oscillation (ENSO) climate mode. Significant abundance increases of L. helicina and S. australis after 1998 were associated with a climate regime shift that initiated a period dominated by cool La Niña conditions and increased nearshore influence of the Antarctic Circumpolar Current (ACC). This background information is essential to assess potential future changes in pteropod species distribution and abundance associated with ocean warming and acidification. construct maps of pteropod spatial frequency and mean abundance to assess their oceanographic associations; quantify pteropod abundance anomalies for comparing intraseasonal and interannual variability relative to m-3 environmental variables and climate modes; investigate the presence of long-term trends and/or cycles of peak abundance of the pteropod species in this region as have been described for krill and salps (Loeb et al., 2009, 2010; Loeb and Santora, 2012). We then examine interannual and longer-term variability of pteropod species abundance with respect to possible effects of the El Niño-Southern Oscillation (ENSO) and Southern Annular Mode (SAM) on population size, advection into and retention within the survey area. In doing so we highlight the importance of having sufficient spatial and temporal sampling coverage, as well as appropriate net mesh size, to establish statistically significant abundance changes associated with climate modes and long-term warming.
ERIC Educational Resources Information Center
Meerschman, Iris; Van Lierde, Kristiane; Van Puyvelde, Caro; Bostyn, Astrid; Claeys, Sofie; D'haeseleer, Evelien
2018-01-01
Background: In contrast with most medical and pharmaceutical therapies, the optimal dosage for voice therapy or training is unknown. Aims: The aim of this study was to compare the effect of a short-term intensive voice training (IVT) with a longer-term traditional voice training (TVT) on the vocal quality and vocal capacities of vocally healthy…
NASA Astrophysics Data System (ADS)
Konrad, C.; Brasher, A.; May, J.
2007-12-01
River restoration depends on re-establishment of the range of physical and biological processes that comprise the river ecosystem. Streamflow is the definitive physical processes for river ecosystems, so hydrologic alteration represents a potentially significant issue to be addressed by restoration efforts. Given adaptation of lotic species to naturally variable streamflow patterns over evolutionary time scales, however, lotic communities are resilient to at least some forms of hydrologic variability. As a result, river restoration may be successful despite limited but biologically insignificant hydrologic alteration. The responses of benthic invertebrate assemblages to variation in streamflow patterns across the western United States were investigated to identify biologically important forms and magnitudes of hydrologic variability. Biological responses to streamflow patterns were analyzed in terms of ceilings and floors on invertebrate assemblage diversity and structure using a non-parametric screening procedure and quantile regression. Variability at daily and monthly time scales was the most common streamflow pattern associated with broad metrics of invertebrate assemblages including abundance; richness and relative abundance of Ephemeroptera, Plecoptera, Trichoptera and non-insects; dominance; and diversity. Low flow magnitude and annual variability were associated with richness and trophic structure. The frequency, magnitude, and duration of high flows were associated with abundance and richness. Longer term streamflow metrics (calculated over at least 5 years) were more important than recent flows (30 and 100 days prior to invertebrate sampling). The results can be used as general guidance about when hydrologic alteration is likely to be an important factor and what streamflow patterns may need to be re-established for successful river restoration.
Long term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396
NASA Astrophysics Data System (ADS)
Chaudhury, K.; Chitnis, V. R.; Rao, A. R.; Singh, K. P.; Bhattacharyya, Sudip; Dewangan, G. C.; Chakraborty, S.; Chandra, S.; Stewart, G. C.; Mukerjee, K.; Dey, R. K.
2018-05-01
We present the results of our study of the long term X-ray variability characteristics of the Narrow Line Seyfert 1 galaxy RE J1034+396. We use data obtained from the AstroSat satellite along with the light curves obtained from XMM-Newton and Swift-XRT. We use the 0.3 - 7.0 keV and 3 - 20 keV data, respectively, from the SXT and the LAXPC of AstroSat. The X-ray spectra in the 0.3 - 20 keV region are well fit with a model consisting of a power-law and a soft excess described by a thermal-Compton emission with a large optical depth, consistent with the earlier reported results. We have examined the X-ray light curves in the soft and hard X-ray bands of SXT and LAXPC, respectively, and find that the variability is slightly larger in the hard band. To investigate the variability characteristics of this source at different time scales, we have used X-ray light curves obtained from XMM-Newton data (200 s to 100 ks range) and Swift-XRT data (1 day to 100 day range) and find that there are evidences to suggest that the variability sharply increases at longer time scales. We argue that the mass of the black hole in RE J1034+396 is likely to be ˜3 × 106 M⊙, based on the similarity of the observed QPO to the high frequency QPO seen in the Galactic black hole binary, GRS 1915+105.
Northern Eurasian Heat Waves and Droughts
NASA Technical Reports Server (NTRS)
Schubert, Siegfried; Wang, Hailan; Koster, Randal; Suarez, Max; Groisman, Pavel
2013-01-01
This article reviews our understanding of the characteristics and causes of northern Eurasian summertime heat waves and droughts. Additional insights into the nature of temperature and precipitation variability in Eurasia on monthly to decadal time scales and into the causes and predictability of the most extreme events are gained from the latest generation of reanalyses and from supplemental simulations with the NASA GEOS-5 AGCM. Key new results are: 1) the identification of the important role of summertime stationary Rossby waves in the development of the leading patterns of monthly Eurasian surface temperature and precipitation variability (including the development of extreme events such as the 2010 Russian heat wave), 2) an assessment of the mean temperature and precipitation changes that have occurred over northern Eurasia in the last three decades and their connections to decadal variability and global trends in SST, and 3) the quantification (via a case study) of the predictability of the most extreme simulated heat wave/drought events, with some focus on the role of soil moisture in the development and maintenance of such events. A literature survey indicates a general consensus that the future holds an enhanced probability of heat waves across northern Eurasia, while there is less agreement regarding future drought, reflecting a greater uncertainty in soil moisture and precipitation projections. Substantial uncertainties remain in our understanding of heat waves and drought, including the nature of the interactions between the short-term atmospheric variability associated with such extremes and the longer-term variability and trends associated with soil moisture feedbacks, SST anomalies, and an overall warming world.
Bank, Matthew; Gibbs, Katie; Sison, Cristina; Kutub, Nawshin; Paptheodorou, Angelos; Lee, Samuel; Stein, Adam; Bloom, Ona
2018-01-01
To identify clinical or demographic variables that influence long-term mortality, as well as in-hospital mortality, with a particular focus on the effects of age. Cervical spine fractures with or without spinal cord injury (SCI) disproportionately impact the elderly who constitute an increasing percentage of the US population. We analyzed data collected for 10 years at a state-designated level I trauma center to identify variables that influenced in-hospital and long-term mortality among elderly patients with traumatic cervical spine fracture with or without SCI. Acute in-hospital mortality was determined from hospital records and long-term mortality within the study period (2003-2013) was determined from the National Death Index. Univariate and multivariate regression analyses were used to identify factors influencing survival. Data from patients (N = 632) with cervical spine fractures were analyzed, the majority (66%) of whom were geriatric (older than age 64). Most patients (62%) had a mild/moderate injury severity score (ISS; median, interquartile range: 6, 5). Patients with SCI had significantly longer lengths of stay (14.1 days), days on a ventilator (3.5 days), and higher ISS (14.9) than patients without SCI ( P < .0001 for all). Falls were the leading mechanism of injury for patients older than age 64. Univariate analysis identified that long-term survival decreased significantly for all patients older than age 65 (hazard ratio [HR]: 1.07; P < .0001). Multivariate analysis demonstrated age (HR: 1.08; P < .0001), gender (HR: 1.60; P < .0007), and SCI status (HR: 1.45, P < .02) significantly influenced survival during the study period. This study identified age, gender, and SCI status as significant variables for this study population influencing long-term survival among patients with cervical spine fractures. Our results support the growing notion that cervical spine injuries in geriatric patients with trauma may warrant additional research.
Bank, Matthew; Gibbs, Katie; Sison, Cristina; Kutub, Nawshin; Paptheodorou, Angelos; Lee, Samuel; Stein, Adam; Bloom, Ona
2018-01-01
Objective: To identify clinical or demographic variables that influence long-term mortality, as well as in-hospital mortality, with a particular focus on the effects of age. Summary and Background Data: Cervical spine fractures with or without spinal cord injury (SCI) disproportionately impact the elderly who constitute an increasing percentage of the US population. Methods: We analyzed data collected for 10 years at a state-designated level I trauma center to identify variables that influenced in-hospital and long-term mortality among elderly patients with traumatic cervical spine fracture with or without SCI. Acute in-hospital mortality was determined from hospital records and long-term mortality within the study period (2003-2013) was determined from the National Death Index. Univariate and multivariate regression analyses were used to identify factors influencing survival. Results: Data from patients (N = 632) with cervical spine fractures were analyzed, the majority (66%) of whom were geriatric (older than age 64). Most patients (62%) had a mild/moderate injury severity score (ISS; median, interquartile range: 6, 5). Patients with SCI had significantly longer lengths of stay (14.1 days), days on a ventilator (3.5 days), and higher ISS (14.9) than patients without SCI (P < .0001 for all). Falls were the leading mechanism of injury for patients older than age 64. Univariate analysis identified that long-term survival decreased significantly for all patients older than age 65 (hazard ratio [HR]: 1.07; P < .0001). Multivariate analysis demonstrated age (HR: 1.08; P < .0001), gender (HR: 1.60; P < .0007), and SCI status (HR: 1.45, P < .02) significantly influenced survival during the study period. Conclusion: This study identified age, gender, and SCI status as significant variables for this study population influencing long-term survival among patients with cervical spine fractures. Our results support the growing notion that cervical spine injuries in geriatric patients with trauma may warrant additional research. PMID:29760965
Correlates of Trail Use for Recreation and Transportation on 5 Massachusetts Trails.
Orstad, Stephanie L; McDonough, Meghan H; Klenosky, David B; Mattson, Marifran; Troped, Philip J
2016-08-01
Promoting use of community trails is a recommended strategy for increasing population levels of physical activity. Correlates of walking and cycling for recreation or transportation differ, though few studies have compared correlates of trail-based physical activity for recreation and transportation purposes. This study examined associations of demographic, social, and perceived built environmental factors with trail use for recreation and transportation and whether associations were moderated by age, gender, and prior trail use. Adults (N = 1195) using 1 of 5 trails in Massachusetts responded to an intercept survey. We used multiple linear and logistic regression models to examine associations with trail use. Respondents' mean age was 44.9 years (standard deviation = 12.5), 55.3% were female, and 82.0% were white. Age (longer-term users only), trail use with others, travel time to the trail, and trail design were significantly associated with use for recreation (P < .05). Age, gender, trail safety (longer-term users only), travel time to the trail, trail design (younger users only), and trail beauty were associated with use for transportation (P < .05). Some common correlates were found for recreational and transportation trail use, whereas some variables were uniquely associated with use for 1 purpose. Tailored strategies are suggested to promote trail use for recreation and transportation.
Tree Carbohydrate Dynamics Across a Rainfall Gradient in Panama During the 2016 ENSO
NASA Astrophysics Data System (ADS)
Dickman, L. T.; Xu, C.; Behar, H.; McDowell, N.
2017-12-01
Non-structural carbohydrates (NSC) provide a measure of the carbon supply available to support respiration, growth, and defense. Support for a role of carbon starvation - or depletion of NSC stores - in drought induced tree mortality is varied without consensus for the tropics. The 2016 ENSO drought provided a unique opportunity to capture drought impacts on tropical forest carbohydrate dynamics. To quantify these impacts, we collected monthly NSC samples across a rainfall gradient in Panama for the duration of the ENSO. We observed high variability in foliar NSC among species within sites. Foliage contained very little starch, indicating that total NSC dynamics are driven by soluble sugars. Foliar NSC depletion did not progress with drought duration as predicted, but showed little variation over course of the ENSO. Foliar NSC did, however, increase with rainfall, suggesting NSC depletion may occur with longer-term drought. These results suggest that, while short-term droughts like the 2016 ENSO may not have a significant impact on carbon dynamics, we may observe greater impacts as drought progresses over longer timescales. These results will be used to evaluate whether the current implementation of carbon starvation in climate models are capturing observed trends in tropical forest carbon allocation and mortality, and to tune model parameters for improved predictive capability.
Poor Long-Term Outcomes of Adult Liver Transplantation Involving Elderly Living Donors.
Tokodai, K; Kawagishi, N; Miyagi, S; Nakanishi, C; Hara, Y; Fujio, A; Kashiwadate, T; Maida, K; Goto, H; Kamei, T; Ohuchi, N
2016-05-01
Donor hepatectomy requires particular care to ensure the safety of the donor and the success of the liver transplantation. The aim of this study was to evaluate the effect of donor age on the postoperative outcomes of liver transplant donors and the long-term graft survival rates. We retrospectively reviewed 56 consecutive adult patients who underwent living donor liver transplantation at our institution between April 2001 and August 2010. Donors and recipients were divided into 2 groups, based on the age of the donor: the elderly donor group (donor age ≥50 years) and the younger donor group (donor age <50 years). Perioperative variables, postoperative complication rates, and long-term graft survival rates were compared between the 2 groups. The average ages in the elderly donor group and younger donor group were 58 years and 32 years, respectively. Baseline data excluding the age of the donor did not differ between the groups, nor did the overall complication rates of the donors. Hospital stays were longer in the elderly donor group than in the younger donor group (25 vs 18 days, P < .05). The 1-, 3-, and 5-year graft survival rates were 80%, 60%, and 50% in the elderly donor group, and 89%, 87%, and 82% in the younger donor group, respectively (P = .0002). Donor hepatectomy can be performed safely in elderly patients. However, compared with younger donors, their hospital stays were longer and the graft survival rates were shorter. Copyright © 2016 Elsevier Inc. All rights reserved.
Anwar, Mohammad Y; Lewnard, Joseph A; Parikh, Sunil; Pitzer, Virginia E
2016-11-22
Malaria remains endemic in Afghanistan. National control and prevention strategies would be greatly enhanced through a better ability to forecast future trends in disease incidence. It is, therefore, of interest to develop a predictive tool for malaria patterns based on the current passive and affordable surveillance system in this resource-limited region. This study employs data from Ministry of Public Health monthly reports from January 2005 to September 2015. Malaria incidence in Afghanistan was forecasted using autoregressive integrated moving average (ARIMA) models in order to build a predictive tool for malaria surveillance. Environmental and climate data were incorporated to assess whether they improve predictive power of models. Two models were identified, each appropriate for different time horizons. For near-term forecasts, malaria incidence can be predicted based on the number of cases in the four previous months and 12 months prior (Model 1); for longer-term prediction, malaria incidence can be predicted using the rates 1 and 12 months prior (Model 2). Next, climate and environmental variables were incorporated to assess whether the predictive power of proposed models could be improved. Enhanced vegetation index was found to have increased the predictive accuracy of longer-term forecasts. Results indicate ARIMA models can be applied to forecast malaria patterns in Afghanistan, complementing current surveillance systems. The models provide a means to better understand malaria dynamics in a resource-limited context with minimal data input, yielding forecasts that can be used for public health planning at the national level.
Gridneva, Zoya; Kugananthan, Sambavi; Hepworth, Anna R; Tie, Wan J; Lai, Ching T; Ward, Leigh C; Hartmann, Peter E; Geddes, Donna T
2016-12-28
Human milk (HM) components influence infant feeding patterns and nutrient intake, yet it is unclear how they influence gastric emptying (GE), a key component of appetite regulation. This study analyzed GE of a single breastfeed, HM appetite hormones/macronutrients and demographics/anthropometrics/body composition of term fully breastfed infants ( n = 41, 2 and/or 5 mo). Stomach volumes (SV) were calculated from pre-/post-feed ultrasound scans, then repeatedly until the next feed. Feed volume (FV) was measured by the test-weigh method. HM samples were analyzed for adiponectin, leptin, fat, lactose, total carbohydrate, lysozyme, and total/whey/casein protein. Linear regression/mixed effect models were used to determine associations between GE/feed variables and HM components/infant anthropometrics/adiposity. Higher FVs were associated with faster (-0.07 [-0.10, -0.03], p < 0.001) GE rate, higher post-feed SVs (0.82 [0.53, 1.12], p < 0.001), and longer GE times (0.24 [0.03, 0.46], p = 0.033). Higher whey protein concentration was associated with higher post-feed SVs (4.99 [0.84, 9.13], p = 0.023). Longer GE time was associated with higher adiponectin concentration (2.29 [0.92, 3.66], p = 0.002) and dose (0.02 [0.01, 0.03], p = 0.005), and lower casein:whey ratio (-65.89 [-107.13, -2.66], p = 0.003). FV and HM composition influence GE and breastfeeding patterns in term breastfed infants.
2013-01-01
Background Computer users often report musculoskeletal complaints and pain in the upper extremities and the neck-shoulder region. However, recent epidemiological studies do not report a relationship between the extent of computer use and work-related musculoskeletal disorders (WMSD). The aim of this study was to conduct an explorative analysis on short and long-term pain complaints and work-related variables in a cohort of Danish computer users. Methods A structured web-based questionnaire including questions related to musculoskeletal pain, anthropometrics, work-related variables, work ability, productivity, health-related parameters, lifestyle variables as well as physical activity during leisure time was designed. Six hundred and ninety office workers completed the questionnaire responding to an announcement posted in a union magazine. The questionnaire outcomes, i.e., pain intensity, duration and locations as well as anthropometrics, work-related variables, work ability, productivity, and level of physical activity, were stratified by gender and correlations were obtained. Results Women reported higher pain intensity, longer pain duration as well as more locations with pain than men (P < 0.05). In parallel, women scored poorer work ability and ability to fulfil the requirements on productivity than men (P < 0.05). Strong positive correlations were found between pain intensity and pain duration for the forearm, elbow, neck and shoulder (P < 0.001). Moderate negative correlations were seen between pain intensity and work ability/productivity (P < 0.001). Conclusions The present results provide new key information on pain characteristics in office workers. The differences in pain characteristics, i.e., higher intensity, longer duration and more pain locations as well as poorer work ability reported by women workers relate to their higher risk of contracting WMSD. Overall, this investigation confirmed the complex interplay between anthropometrics, work ability, productivity, and pain perception among computer users. PMID:23915209
Tosh, Jonathan; Kearns, Ben; Brennan, Alan; Parry, Glenys; Ricketts, Thomas; Saxon, David; Kilgarriff-Foster, Alexis; Thake, Anna; Chambers, Eleni; Hutten, Rebecca
2013-04-26
The purpose of the analysis was to develop a health economic model to estimate the costs and health benefits of alternative National Health Service (NHS) service configurations for people with longer-term depression. Modelling methods were used to develop a conceptual and health economic model of the current configuration of services in Sheffield, England for people with longer-term depression. Data and assumptions were synthesised to estimate cost per Quality Adjusted Life Years (QALYs). Three service changes were developed and resulted in increased QALYs at increased cost. Versus current care, the incremental cost-effectiveness ratio (ICER) for a self-referral service was £11,378 per QALY. The ICER was £2,227 per QALY for the dropout reduction service and £223 per QALY for an increase in non-therapy services. These results were robust when compared to current cost-effectiveness thresholds and accounting for uncertainty. Cost-effective service improvements for longer-term depression have been identified. Also identified were limitations of the current evidence for the long term impact of services.
Moyer-Horner, Lucas; Beever, Erik A; Johnson, Douglas H; Biel, Mark; Belt, Jami
2016-01-01
American pikas (Ochotona princeps) have been heralded as indicators of montane-mammal response to contemporary climate change. Pikas no longer occupy the driest and lowest-elevation sites in numerous parts of their geographic range. Conversely, pikas have exhibited higher rates of occupancy and persistence in Rocky Mountain and Sierra Nevada montane 'mainlands'. Research and monitoring efforts on pikas across the western USA have collectively shown the nuance and complexity with which climate will often act on species in diverse topographic and climatic contexts. However, to date no studies have investigated habitat, distribution, and abundance of pikas across hundreds of sites within a remote wilderness area. Additionally, relatively little is known about whether climate acts most strongly on pikas through direct or indirect (e.g., vegetation-mediated) mechanisms. During 2007-2009, we collectively hiked >16,000 km throughout the 410,077-ha Glacier National Park, Montana, USA, in an effort to identify topographic, microrefugial, and vegetative characteristics predictive of pika abundance. We identified 411 apparently pika-suitable habitat patches with binoculars (in situ), and surveyed 314 of them for pika signs. Ranking of alternative logistic-regression models based on AICc scores revealed that short-term pika abundances were positively associated with intermediate elevations, greater cover of mosses, and taller forbs, and decreased each year, for a total decline of 68% during the three-year study; whereas longer-term abundances were associated only with static variables (longitude, elevation, gradient) and were lower on north-facing slopes. Earlier Julian date and time of day of the survey (i.e., midday vs. not) were associated with lower observed pika abundance. We recommend that wildlife monitoring account for this seasonal and diel variation when surveying pikas. Broad-scale information on status and abundance determinants of montane mammals, especially for remote protected areas, is crucial for land and wildlife-resource managers trying to anticipate mammalian responses to climate change.
Moyer-Horner, Lucas; Beever, Erik A.; Johnson, Douglas H.; Beil, Mark; Belt, Jami
2016-01-01
American pikas (Ochotona princeps) have been heralded as indicators of montane-mammal response to contemporary climate change. Pikas no longer occupy the driest and lowest-elevation sites in numerous parts of their geographic range. Conversely, pikas have exhibited higher rates of occupancy and persistence in Rocky Mountain and Sierra Nevada montane ‘mainlands’. Research and monitoring efforts on pikas across the western USA have collectively shown the nuance and complexity with which climate will often act on species in diverse topographic and climatic contexts. However, to date no studies have investigated habitat, distribution, and abundance of pikas across hundreds of sites within a remote wilderness area. Additionally, relatively little is known about whether climate acts most strongly on pikas through direct or indirect (e.g., vegetation-mediated) mechanisms. During 2007–2009, we collectively hiked >16,000 km throughout the 410,077-ha Glacier National Park, Montana, USA, in an effort to identify topographic, microrefugial, and vegetative characteristics predictive of pika abundance. We identified 411 apparently pika-suitable habitat patches with binoculars (in situ), and surveyed 314 of them for pika signs. Ranking of alternative logistic-regression models based on AICc scores revealed that short-term pika abundances were positively associated with intermediate elevations, greater cover of mosses, and taller forbs, and decreased each year, for a total decline of 68% during the three-year study; whereas longer-term abundances were associated only with static variables (longitude, elevation, gradient) and were lower on north-facing slopes. Earlier Julian date and time of day of the survey (i.e., midday vs. not) were associated with lower observed pika abundance. We recommend that wildlife monitoring account for this seasonal and diel variation when surveying pikas. Broad-scale information on status and abundance determinants of montane mammals, especially for remote protected areas, is crucial for land and wildlife-resource managers trying to anticipate mammalian responses to climate change.
Moyer-Horner, Lucas; Beever, Erik A.; Johnson, Douglas H.; Biel, Mark; Belt, Jami
2016-01-01
American pikas (Ochotona princeps) have been heralded as indicators of montane-mammal response to contemporary climate change. Pikas no longer occupy the driest and lowest-elevation sites in numerous parts of their geographic range. Conversely, pikas have exhibited higher rates of occupancy and persistence in Rocky Mountain and Sierra Nevada montane ‘mainlands’. Research and monitoring efforts on pikas across the western USA have collectively shown the nuance and complexity with which climate will often act on species in diverse topographic and climatic contexts. However, to date no studies have investigated habitat, distribution, and abundance of pikas across hundreds of sites within a remote wilderness area. Additionally, relatively little is known about whether climate acts most strongly on pikas through direct or indirect (e.g., vegetation-mediated) mechanisms. During 2007–2009, we collectively hiked >16,000 km throughout the 410,077-ha Glacier National Park, Montana, USA, in an effort to identify topographic, microrefugial, and vegetative characteristics predictive of pika abundance. We identified 411 apparently pika-suitable habitat patches with binoculars (in situ), and surveyed 314 of them for pika signs. Ranking of alternative logistic-regression models based on AICc scores revealed that short-term pika abundances were positively associated with intermediate elevations, greater cover of mosses, and taller forbs, and decreased each year, for a total decline of 68% during the three-year study; whereas longer-term abundances were associated only with static variables (longitude, elevation, gradient) and were lower on north-facing slopes. Earlier Julian date and time of day of the survey (i.e., midday vs. not) were associated with lower observed pika abundance. We recommend that wildlife monitoring account for this seasonal and diel variation when surveying pikas. Broad-scale information on status and abundance determinants of montane mammals, especially for remote protected areas, is crucial for land and wildlife-resource managers trying to anticipate mammalian responses to climate change. PMID:27902732
NASA Technical Reports Server (NTRS)
Molnar, Gyula; Susskind, Joel; Iredell, Lena
2010-01-01
The ROBUST nature (biases are not as important as previous GCM-evaluations suggest) of the AIRS-observations-generated ARC-maps and ATs as well as their interrelations suggest that they could be a useful tool to select CGCMs which may be considered the reliable, i.e., to be trusted even for longer-term climate drift/change predictions (even on the regional scale). Get monthly gridded CGCM time-series of atmospheric variables coinciding with the timeframe of the AIRS analyses for at least 5-6 years and do the actual evaluations of ARC-maps and ATs for the coinciding time periods.
Outburst activity of the symbiotic system AG Dra
NASA Astrophysics Data System (ADS)
Hric, L.; Gális, R.; Leedjärv, L.; Burmeister, M.; Kundra, E.
2014-09-01
AG Dra is a well-known bright symbiotic binary with a white dwarf and a pulsating red giant. Long-term photometry monitoring and a new behaviour of the system are presented. A detailed period analysis of photometry as well as spectroscopy was carried out. In the system of AG Dra, two periods of variability are detected. The longer one around 550 d is related to the orbital motion and the shorter one around 355 d was interpreted as pulsations of the red giant in our previous article. In addition, the active stages change distinctively, but the outbursts are repeated with periods from 359-375 d.
NASA Astrophysics Data System (ADS)
Cliver, E. W.; von Steiger, R.
2017-09-01
During the last decade it has been proposed that both the Sun and the solar wind have minimum magnetic states, lowest order levels of magnetism that underlie the 11-yr cycle as well as longer-term variability. Here we review the literature on basal magnetic states at the Sun and in the heliosphere and draw a connection between the two based on the recent deep 2008-2009 minimum between cycles 23 and 24. In particular, we consider the implications of the low solar activity during the recent minimum for the origin of the slow solar wind.
Describing temporal variability of the mean Estonian precipitation series in climate time scale
NASA Astrophysics Data System (ADS)
Post, P.; Kärner, O.
2009-04-01
Applicability of the random walk type models to represent the temporal variability of various atmospheric temperature series has been successfully demonstrated recently (e.g. Kärner, 2002). Main problem in the temperature modeling is connected to the scale break in the generally self similar air temperature anomaly series (Kärner, 2005). The break separates short-range strong non-stationarity from nearly stationary longer range variability region. This is an indication of the fact that several geophysical time series show a short-range non-stationary behaviour and a stationary behaviour in longer range (Davis et al., 1996). In order to model series like that the choice of time step appears to be crucial. To characterize the long-range variability we can neglect the short-range non-stationary fluctuations, provided that we are able to model properly the long-range tendencies. The structure function (Monin and Yaglom, 1975) was used to determine an approximate segregation line between the short and the long scale in terms of modeling. The longer scale can be called climate one, because such models are applicable in scales over some decades. In order to get rid of the short-range fluctuations in daily series the variability can be examined using sufficiently long time step. In the present paper, we show that the same philosophy is useful to find a model to represent a climate-scale temporal variability of the Estonian daily mean precipitation amount series over 45 years (1961-2005). Temporal variability of the obtained daily time series is examined by means of an autoregressive and integrated moving average (ARIMA) family model of the type (0,1,1). This model is applicable for daily precipitation simulating if to select an appropriate time step that enables us to neglet the short-range non-stationary fluctuations. A considerably longer time step than one day (30 days) is used in the current paper to model the precipitation time series variability. Each ARIMA (0,1,1) model can be interpreted to be consisting of random walk in a noisy environment (Box and Jenkins, 1976). The fitted model appears to be weakly non-stationary, that gives us the possibility to use stationary approximation if only the noise component from that sum of white noise and random walk is exploited. We get a convenient routine to generate a stationary precipitation climatology with a reasonable accuracy, since the noise component variance is much larger than the dispersion of the random walk generator. This interpretation emphasizes dominating role of a random component in the precipitation series. The result is understandable due to a small territory of Estonia that is situated in the mid-latitude cyclone track. References Box, J.E.P. and G. Jenkins 1976: Time Series Analysis, Forecasting and Control (revised edn.), Holden Day San Francisco, CA, 575 pp. Davis, A., Marshak, A., Wiscombe, W. and R. Cahalan 1996: Multifractal characterizations of intermittency in nonstationary geophysical signals and fields.in G. Trevino et al. (eds) Current Topics in Nonsstationarity Analysis. World-Scientific, Singapore, 97-158. Kärner, O. 2002: On nonstationarity and antipersistency in global temperature series. J. Geophys. Res. D107; doi:10.1029/2001JD002024. Kärner, O. 2005: Some examples on negative feedback in the Earth climate system. Centr. European J. Phys. 3; 190-208. Monin, A.S. and A.M. Yaglom 1975: Statistical Fluid Mechanics, Vol 2. Mechanics of Turbulence , MIT Press Boston Mass, 886 pp.
NASA Astrophysics Data System (ADS)
Maes, C.; Grima, N.; Blanke, B.; Martinez, E.; Paviet-Salomon, T.; Huck, T.
2018-02-01
We study the dispersion and convergence of marine floating material by surface currents from a model reanalysis that represents explicitly mesoscale eddy variability. Lagrangian experiments about the long-term evolution (29 years) of an initially homogeneous concentration of particles are performed at global scale with horizontal current at one fourth degree resolution and refreshed daily over the 1985-2013 period. Results not only confirm and document the five known sites of surface convergence at the scale of individual oceanic basins but also reveal a convergent pathway connecting the South Indian subtropical region with the convergence zone of the South Pacific through the Great Australian Bight, the Tasman Sea, and the southwest Pacific Ocean. This "superconvergent" pathway at the ocean surface is robust and permanent over a distance longer than 8,000 km. The current variability is crucial to sustain this pathway.
North Atlantic variability and its links to European climate over the last 3000 years.
Moffa-Sánchez, Paola; Hall, Ian R
2017-11-23
The subpolar North Atlantic is a key location for the Earth's climate system. In the Labrador Sea, intense winter air-sea heat exchange drives the formation of deep waters and the surface circulation of warm waters around the subpolar gyre. This process therefore has the ability to modulate the oceanic northward heat transport. Recent studies reveal decadal variability in the formation of Labrador Sea Water. Yet, crucially, its longer-term history and links with European climate remain limited. Here we present new decadally resolved marine proxy reconstructions, which suggest weakened Labrador Sea Water formation and gyre strength with similar timing to the centennial cold periods recorded in terrestrial climate archives and historical records over the last 3000 years. These new data support that subpolar North Atlantic circulation changes, likely forced by increased southward flow of Arctic waters, contributed to modulating the climate of Europe with important societal impacts as revealed in European history.
Time-resolved spectroscopyHiifill of the peculiar Hα variable Be star HD 76534
NASA Astrophysics Data System (ADS)
Oudmaijer, René D.; Drew, Janet E.
1999-10-01
We present time-resolved spectroscopy of the Be star HD 76534, which was observed to have an Hα outburst in 1995, when the line went from photospheric absorption to emission at a level of more than two times the continuum within 2.5 hours. To investigate the short-term behaviour of the spectrum of HD 76534 we have obtained 30 spectra within two hours real-time and searched for variations in the spectrum. Within the levels of statistical significance, no variability was found. Rather than periodic on short time scales, the Hα behaviour seems to be commonly episodic on longer (> 1 year) time scales, as an assessment of the existing data on the Hα line and the Hipparcos photometry suggests. HD 76534 underwent only 1 photometric outburst in the 3 year span that the star was monitored by the Hipparcos satellite.
Jochner, Matthias; Bugmann, Harald; Nötzli, Magdalena; Bigler, Christof
2017-10-01
Upper treeline ecotones are important life form boundaries and particularly sensitive to a warming climate. Changes in growth conditions at these ecotones have wide-ranging implications for the provision of ecosystem services in densely populated mountain regions like the European Alps. We quantify climate effects on short- and long-term tree growth responses, focusing on among-tree variability and potential feedback effects. Although among-tree variability is thought to be substantial, it has not been considered systematically yet in studies on growth-climate relationships. We compiled tree-ring data including almost 600 trees of major treeline species ( Larix decidua , Picea abies , Pinus cembra , and Pinus mugo ) from three climate regions of the Swiss Alps. We further acquired tree size distribution data using unmanned aerial vehicles. To account for among-tree variability, we employed information-theoretic model selections based on linear mixed-effects models (LMMs) with flexible choice of monthly temperature effects on growth. We isolated long-term trends in ring-width indices (RWI) in interaction with elevation. The LMMs revealed substantial amounts of previously unquantified among-tree variability, indicating different strategies of single trees regarding when and to what extent to invest assimilates into growth. Furthermore, the LMMs indicated strongly positive temperature effects on growth during short summer periods across all species, and significant contributions of fall ( L. decidua ) and current year's spring ( L. decidua , P. abies ). In the longer term, all species showed consistently positive RWI trends at highest elevations, but different patterns with decreasing elevation. L. decidua exhibited even negative RWI trends compared to the highest treeline sites, whereas P. abies , P. cembra , and P. mugo showed steeper or flatter trends with decreasing elevation. This does not only reflect effects of ameliorated climate conditions on tree growth over time, but also reveals first signs of long-suspected negative and positive feedback of climate change on stand dynamics at treeline.
NASA Astrophysics Data System (ADS)
Clear, J.; Chiverrell, R. C.; Kunes, P.; Boyle, J.; Kuosmanen, N.; Carter, V.
2016-12-01
The montane Norway spruce (Picea abies) dominated forests of Central Europe are a niche environment; situated outside their natural boreal distribution they are vulnerable to both short term disturbances (e.g. floods, avalanches, fire, windstorm and pathogens) and longer-term environmental change (e.g. climate induced stress, snow regimes). Holocene sediment records from lakes in the High Tatra (Slovakia) and Bohemian (Czech) Mountains show repeated disturbances of the pristine Picea abies-dominated forests as sharp well defined minerogenic in-wash horizons that punctuate the accumulation of organic gyttja. These event horizons span a process continuum from lakes with restricted catchments and limited inflow (e.g. Prazilske Lake, Czech) to more catchment-process dominated lakes with large catchments (e.g. Popradske Lake, Slovakia). The events include complex responses to a global climatic downturn at 8.2ka, other cooler episodes 3.5, 1.6 and 0.5 ka, and to recent discrete wind-storms and pathogen outbreaks. We develop a typology for disturbance events using sediment geochemistry, particle size, mineral magnetism, charcoal and palaeoecology to assess likely drivers of disturbance. For the recent past integrating data from dendroecology and sediments is used to calibrate our longer-term perspective on forest dynamics. Tree-ring series from plots or forest stands are used alongside lake and forest hollow sediments to explore the local, regional and biogeographical scale of forest disturbances. Dendroecological data showing tree-ring gap recruitment and post-suppression growth release highlight frequent disturbance events focused on tree or forest stand spatial scales, but are patchy in terms of their reoccurrence. However they highlight levels of disturbance in the late 19th Century and parallel lake and forest hollow sediments record variable pollen influx (beetle host / non-host ratios) and stratigraphies that include mineral in-wash events. The identified recent and ongoing forest disturbances coupled with well-evidenced events in the 19th century highlight the need for the longer sedimentary perspective to assess whether contemporary climate warming has and continues to stretch the resilience of these fragile ecosystems.
Su, Bobo; Yang, Ling; Wang, Grace Y; Wang, Sha; Li, Shaomei; Cao, Hua; Zhang, Yan
2017-11-01
Chronic heroin use can cause a deficit of inhibitory function, leading to a loss of control over drug use. Exposure to drug-related cues is considered as one of the contributing factors. However, it is unclear whether there are dynamic changes on the effect of drug-related cues on response inhibition following prolonged abstinence. The present study investigated the effect of drug-related cues on response inhibition in heroin abstainers at different abstinent phases. 26 shorter-term (2-6 months) and 26 longer-term (19-24 months) male heroin abstainers performed on a modified two-choice Oddball task, which included two conditions: in the cued condition, neutral pictures served as the background of standard stimuli (yellow frame) and heroin-related pictures served as the background of deviant stimuli (blue frame), reversed in the controlled conditions. Compared to longer-term abstainers, mean reaction time (RT) for drug deviants in shorter-term abstainers was significantly longer. Shorter-term abstainers also showed markedly slower response to neutral deviants relative to drug deviants, but this tendency was not observed in longer-term abstainers. Nevertheless, both groups had similar RT for standard stimuli regardless of their paired background pictures. Effect of drug-related cues on response inhibition remains at the early stage of abstinence; however, this effect may be reduced following a longer period of drug abstinence. Our findings highlight the importance of assessing and improving the ability of inhibiting drug-related cue reactivity during treatment.
Baker, F; Wigram, T; Gold, C
2005-07-01
To examine changes in the relationship between intonation, voice range and mood following music therapy programmes in people with traumatic brain injury. Data from four case studies were pooled and effect size, ANOVA and correlation calculations were performed to evaluate the effectiveness of treatment. Subjects sang three self-selected songs for 15 sessions. Speaking fundamental frequency, fundamental frequency variability, slope, voice range and mood were analysed pre- and post-session. Immediate treatment effects were not found. Long-term improvements in affective intonation were found in three subjects, especially in fundamental frequency. Voice range improved over time and was positively correlated with the three intonation components. Mood scale data showed that immediate effects were in the negative direction whereas there weres increases in positive mood state in the longer-term. Findings suggest that, in the long-term, song singing can improve vocal range and mood and enhance the affective intonation styles of people with TBI.
Workshop: Theory an Applications of Coupled Cell Networks
2006-03-22
physical location and environment and the scientific inter- actions with the longer term participants in the PFD programme. Furthermore, the Institute...in generating a tangible air of excitement about the challenges posed by coupled cell systems, both in terms of the mathematical questions, and in the...longer term visitors interacted with the workshop participants, and by focusing on a slightly different collection of themes, the workshop participants
Gathercole, Susan E; Briscoe, Josie; Thorn, Annabel; Tiffany, Claire
2008-03-01
Possible links between phonological short-term memory and both longer term memory and learning in 8-year-old children were investigated in this study. Performance on a range of tests of long-term memory and learning was compared for a group of 16 children with poor phonological short-term memory skills and a comparison group of children of the same age with matched nonverbal reasoning abilities but memory scores in the average range. The low-phonological-memory group were impaired on longer term memory and learning tasks that taxed memory for arbitrary verbal material such as names and nonwords. However, the two groups performed at comparable levels on tasks requiring the retention of visuo-spatial information and of meaningful material and at carrying out prospective memory tasks in which the children were asked to carry out actions at a future point in time. The results are consistent with the view that poor short-term memory function impairs the longer-term retention and ease of learning of novel verbal material.
NASA Astrophysics Data System (ADS)
Friedl, M. A.; Melaas, E. K.; Sulla-menashe, D. J.; Gray, J. M.
2014-12-01
Phenology, the seasonal progression of organisms through stages of dormancy, active growth, and senescence is a key regulator of ecosystem processes and is widely used as an indicator of vegetation responses to climate change. This is especially true in temperate forests, where seasonal dynamics in canopy development and senescence are tightly coupled to the climate system. Despite this, understanding of climate-phenology interactions is incomplete. A key impediment to improving this understanding is that available datasets are geographically sparse, and in most cases include relatively short time series. Remote sensing has been widely promoted as a useful tool for studies of large-scale phenology, but long-term studies from remote sensing have been limited to AVHRR data, which suffers from limitations related to its coarse spatial resolution and uncertainties in atmospheric corrections and radiometric adjustments that are used to create AVHRR time series. In this study, we used 30 years of Landsat data to quantify the nature and magnitude of long-term trends and short-term variability in the timing of spring leaf emergence and fall senescence. Our analysis focuses on temperate forest locations in the Northeastern United States that are co-located with surface meteorological observations, where we have estimated the timing of leaf emergence and leaf senescence at annual time steps using atmospherically corrected surface reflectances from Landsat TM and ETM+ imagery. Comparison of results from Landsat against ground observations demonstrates that phenological events can be reliably estimated from Landsat time series. More importantly, results from this analysis suggest two main conclusions related to the nature of climate change impacts on temperate forest phenology. First, there is clear evidence of trends towards longer growing seasons in the Landsat record. Second, interannual variability is large, with average year-to-year variability exceeding the magnitude of total changes to the growing season that have occurred over the last three decades. Based on these results we suggest that year-to-year variability in phenology, rather than long-term trends, provides the best basis for predicting future changes in temperate forest phenology in response to climate change.
Nonlinear Dynamics of Complex Coevolutionary Systems in Historical Times
NASA Astrophysics Data System (ADS)
Perdigão, Rui A. P.
2016-04-01
A new theoretical paradigm for statistical-dynamical modeling of complex coevolutionary systems is introduced, with the aim to provide historical geoscientists with a practical tool to analyse historical data and its underlying phenomenology. Historical data is assumed to represent the history of dynamical processes of physical and socio-economic nature. If processes and their governing laws are well understood, they are often treated with traditional dynamical equations: deterministic approach. If the governing laws are unknown or impracticable, the process is often treated as if being random (even if it is not): statistical approach. Although single eventful details - such as the exact spatiotemporal structure of a particular hydro-meteorological incident - may often be elusive to a detailed analysis, the overall dynamics exhibit group properties summarized by a simple set of categories or dynamical regimes at multiple scales - from local short-lived convection patterns to large-scale hydro-climatic regimes. The overwhelming microscale complexity is thus conveniently wrapped into a manageable group entity, such as a statistical distribution. In a stationary setting whereby the distribution is assumed to be invariant, alternating regimes are approachable as dynamical intermittence. For instance, in the context of bimodal climatic oscillations such as NAO and ENSO, each mode corresponds to a dynamical regime or phase. However, given external forcings or longer-term internal variability and multiscale coevolution, the structural properties of the system may change. These changes in the dynamical structure bring about a new distribution and associated regimes. The modes of yesteryear may no longer exist as such in the new structural order of the system. In this context, aside from regime intermittence, the system exhibits structural regime change. New oscillations may emerge whilst others fade into the annals of history, e.g. particular climate fluctuations during the Little Ice Age. Traditional theories of stochastic processes and dynamical systems are grounded on the existence of so-called dynamical invariants; properties that remain unchanged as the dynamics unfold, assuming structural invariance and ergodicity of the underlying system. However, such theories are no longer optimal when trying to understand and model long-term historical records of coevolutionary systems. A new paradigm is thus needed. Therefore, we introduce a new class of dynamical systems that reinvent themselves as the dynamics unfold. Rather than only changing variables and parameters under a rigid framework, the governing laws are malleable themselves. The novel formulation captures and explains the coevolutionary dynamics of multiscale hydroclimatic systems, bringing along a physically sound understanding of their regimes, transitions and extremes over a long-term history.
Seasonal controls of the short term variability of pCO2 at the Scotian Shelf
NASA Astrophysics Data System (ADS)
Thomas, H.; Craig, S.; Greenan, B. J. W.; Burt, W.; Herndl, G. J.; Higginson, S.; Salt, L.; Shadwick, E. H.; Urrego-Blanco, J.
2012-04-01
Much of the surface ocean carbon cycle variability can be attributed to the availability of sunlight, through processes such as heat fluxes or photosynthesis, which regulate the ocean carbon cycle over a wide range of time scales. The critical processes occurring on timescales of a day or less, however, have undergone few investigations, and most of those have been limited to a time span of several days to months, or exceptionally, for longer periods. Optical methods have helped to infer short-term biological variability, however lacking corresponding investigations of oceanic CO2 system. Here, we employ high-frequency CO2 system and optical observations covering the full seasonal cycle on the Scotian Shelf, Northwestern Atlantic Ocean, in order to unravel daily periodicity of the surface ocean carbon cycle and its effects on annual budgets. We show that significant daily periodicity occurs only if the water column is sufficiently stable as observed during seasonal warming. During that time biological CO2 drawdown, or net community production (NCP), is delayed for several hours relative to the daylight cycle due the daily build-up of essential Chlorophyll a, to cell physiology and to grazing effects, all restricting or hindering photosynthesis in the early morning hours. NCP collapses in summer by more than 90%, when the mixed layer depth reaches the seasonal minimum, which eventually makes the observed daily periodicity of the CO2 system vanish.
Scannapieco, Frank A; Amin, Summar; Salme, Marc; Tezal, Mine
2017-03-01
To describe factors associated with the utilization of dental services in a long-term care facility (LTCF) in Western New York. A descriptive cross-sectional study reviewed the dental and medical records of residents of an LTCF discharged between January 1, 2008 and December 30, 2012. Information on demographic and health variables at admission was extracted from electronic health records. Information on oral health variables was extracted from patient charts. A total of 2,516 residents were discharged between 2008 and 2012. From those, 259 (10.3%) utilized dental services at least once during their stay. Those who utilized dental services were significantly older at admission (78.5 vs. 82.0 years, p < 0.001), stayed longer (1.6 vs. 3.9 years, p < 0.001), more likely to be female (63.6 vs. 75.6%, p = 0.008), and less likely to be married (37.7 vs. 14.0%, p = < 0.001) compared to those who did not. Patients with endocrine, nutritional, metabolic, and immunity disorders, mental disorders, and circulatory system diseases were more likely to receive dental services. Dental services appear to be underutilized by residents of LTCF. Significant differences exist in demographic and health variables between residents who utilize these services compared to those who do not. © 2016 Special Care Dentistry Association and Wiley Periodicals, Inc.
A Comparison of Long- vs. Short-Term Recall of Substance Use and HIV Risk Behaviors.
Janssen, Tim; Braciszewski, Jordan M; Vose-O'Neal, Adam; Stout, Robert L
2017-05-01
The Timeline Follow-back (TLFB) questionnaire has become a pre-eminent tool in substance use and human immunodeficiency virus (HIV) risk research, allowing researchers to assess fine-grained changes in risk behavior over long periods. However, data on accuracy of recall over long (12-month) periods are sparse, especially combined data on HIV risk and substance use from post-treatment samples. Studies on the development of substance use and HIV risk stand to benefit from data on the accurate recall of such behavior over longer retroactive spans of time. The present study offers data on the test-retest reliability of current TLFB assessment versus 6- and 12-month delayed TLFB assessment, using a post-treatment sample (n = 50). Long-term reliability of TLFB data on HIV risk was predominantly good to excellent, with 13 of 20 assessed variables in that range. TLFB data on substance use was similar, with 22 of 26 variables resulting in good/excellent reliability. Our findings support the notion that, notable exceptions aside, the TLFB may be effectively used to assess retroactive HIV risk and substance use in periods of 12 months.
Where Is the Flux Going? The Long-term Photometric Variability of Boyajian’s Star
NASA Astrophysics Data System (ADS)
Simon, Joshua D.; Shappee, Benjamin J.; Pojmański, G.; Montet, Benjamin T.; Kochanek, C. S.; van Saders, Jennifer; Holoien, T. W.-S.; Henden, Arne A.
2018-01-01
We present ∼800 days of photometric monitoring of Boyajian’s Star (KIC 8462852) from the All-Sky Automated Survey for Supernovae (ASAS-SN) and ∼4000 days of monitoring from the All Sky Automated Survey (ASAS). We show that from 2015 to the present the brightness of Boyajian’s Star has steadily decreased at a rate of 6.3 ± 1.4 mmag yr‑1, such that the star is now 1.5% fainter than it was in 2015 February. Moreover, the longer time baseline afforded by ASAS suggests that Boyajian’s Star has also undergone two brightening episodes in the past 11 years, rather than only exhibiting a monotonic decline. We analyze a sample of ∼1000 comparison stars of similar brightness located in the same ASAS-SN field and demonstrate that the recent fading is significant at ≳99.4% confidence. The 2015–2017 dimming rate is consistent with that measured with Kepler data for the time period from 2009 to 2013. This long-term variability is difficult to explain with any of the physical models for the star’s behavior proposed to date.
Modelling survival: exposure pattern, species sensitivity and uncertainty.
Ashauer, Roman; Albert, Carlo; Augustine, Starrlight; Cedergreen, Nina; Charles, Sandrine; Ducrot, Virginie; Focks, Andreas; Gabsi, Faten; Gergs, André; Goussen, Benoit; Jager, Tjalling; Kramer, Nynke I; Nyman, Anna-Maija; Poulsen, Veronique; Reichenberger, Stefan; Schäfer, Ralf B; Van den Brink, Paul J; Veltman, Karin; Vogel, Sören; Zimmer, Elke I; Preuss, Thomas G
2016-07-06
The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans.
Tree ring imprints of long-term changes in climate in western Himalaya, India.
Yadav, R R
2009-11-01
Tree-ring analyses from semi-arid to arid regions in western Himalaya show immense potential for developing millennia long climate records. Millennium and longer ring-width chronologies of Himalayan pencil juniper (Juniperus polycarpos), Himalayan pencil cedar (Cedrus deodara) and Chilgoza pine (Pinus gerardiana) have been developed from different sites in western Himalaya. Studies conducted so far on various conifer species indicate strong precipitation signatures in ring-width measurement series. The paucity of weather records from stations close to tree-ring sampling sites poses diffi culty in calibrating tree-ring data against climate data especially precipitation for its strong spatial variability in mountain regions. However, for the existence of strong coherence in temperature, even in data from distant stations, more robust temperature reconstructions representing regional and hemispheric signatures have been developed. Tree-ring records from the region indicate multi-century warm and cool anomalies consistent with the Medieval Warm Period and Little Ice Age anomalies. Signifi cant relationships noted between mean premonsoon temperature over the western Himalaya and ENSO features endorse utility of climate records from western Himalayan region in understanding long-term climate variability and attribution of anthropogenic impact.
Use of a tracing task to assess visuomotor performance for evidence of concussion and recuperation.
Kelty-Stephen, Damian G; Qureshi Ahmad, Mona; Stirling, Leia
2015-12-01
The likelihood of suffering a concussion while playing a contact sport ranges from 15-45% per year of play. These rates are highly variable as athletes seldom report concussive symptoms, or do not recognize their symptoms. We performed a prospective cohort study (n = 206, aged 10-17) to examine visuomotor tracing to determine the sensitivity for detecting neuromotor components of concussion. Tracing variability measures were investigated for a mean shift with presentation of concussion-related symptoms and a linear return toward baseline over subsequent return visits. Furthermore, previous research relating brain injury to the dissociation of smooth movements into "submovements" led to the expectation that cumulative micropause duration, a measure of motion continuity, might detect likelihood of injury. Separate linear mixed effects regressions of tracing measures indicated that 4 of the 5 tracing measures captured both short-term effects of injury and longer-term effects of recovery with subsequent visits. Cumulative micropause duration has a positive relationship with likelihood of participants having had a concussion. The present results suggest that future research should evaluate how well the coefficients for the tracing parameter in the logistic regression help to detect concussion in novel cases. (c) 2015 APA, all rights reserved).
Modelling survival: exposure pattern, species sensitivity and uncertainty
NASA Astrophysics Data System (ADS)
Ashauer, Roman; Albert, Carlo; Augustine, Starrlight; Cedergreen, Nina; Charles, Sandrine; Ducrot, Virginie; Focks, Andreas; Gabsi, Faten; Gergs, André; Goussen, Benoit; Jager, Tjalling; Kramer, Nynke I.; Nyman, Anna-Maija; Poulsen, Veronique; Reichenberger, Stefan; Schäfer, Ralf B.; van den Brink, Paul J.; Veltman, Karin; Vogel, Sören; Zimmer, Elke I.; Preuss, Thomas G.
2016-07-01
The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans.
van der Garde, Mark; van Hensbergen, Yvette; Brand, Anneke; Slot, Manon C; de Graaf-Dijkstra, Alice; Mulder, Arend; Watt, Suzanne M; Zwaginga, Jaap Jan
2015-01-01
Human cord blood (CB) hematopoietic stem cell (HSC) transplants demonstrate delayed early neutrophil and platelet recovery and delayed longer term immune reconstitution compared to bone marrow and mobilized peripheral blood transplants. Despite advances in enhancing early neutrophil engraftment, platelet recovery after CB transplantation is not significantly altered when compared to contemporaneous controls. Recent studies have identified a platelet-biased murine HSC subset, maintained by thrombopoietin (TPO), which has enhanced capacity for short- and long-term platelet reconstitution, can self-renew, and can give rise to myeloid- and lymphoid-biased HSCs. In previous studies, we have shown that transplantation of human CB CD34(+) cells precultured in TPO as a single graft accelerates early platelet recovery as well as yielding long-term repopulation in immune-deficient mice. In this study, using a double CB murine transplant model, we investigated whether TPO cultured human CB CD34(+) cells have a competitive advantage or disadvantage over untreated human CB CD34(+) cells in terms of (1) short-term and longer term platelet recovery and (2) longer term hematological recovery. Our studies demonstrate that the TPO treated graft shows accelerated early platelet recovery without impairing the platelet engraftment of untreated CD34(+) cells. Notably, this was followed by a dominant contribution to platelet production through the untreated CD34(+) cell graft over the intermediate to longer term. Furthermore, although the contribution of the TPO treated graft to long-term hematological engraftment was reduced, the TPO treated and untreated grafts both contributed significantly to long-term chimerism in vivo.
Airmen with mild traumatic brain injury (mTBI) at increased risk for subsequent mishaps.
Whitehead, Casserly R; Webb, Timothy S; Wells, Timothy S; Hunter, Kari L
2014-02-01
Little is known regarding long-term performance decrements associated with mild Traumatic Brain Injury (mTBI). The goal of this study was to determine if individuals with an mTBI may be at increased risk for subsequent mishaps. Cox proportional hazards modeling was utilized to calculate hazard ratios for 518,958 active duty U.S. Air Force service members (Airmen) while controlling for varying lengths of follow-up and potentially confounding variables. Two non-mTBI comparison groups were used; the second being a subset of the original, both without head injuries two years prior to study entrance. Hazard ratios indicate that the causes of increased risk associated with mTBI do not resolve quickly. Additionally, outpatient mTBI injuries do not differ from other outpatient bodily injuries in terms of subsequent injury risk. These findings suggest that increased risk for subsequent mishaps are likely due to differences shared among individuals with any type of injury, including risk-taking behaviors, occupations, and differential participation in sports activities. Therefore, individuals who sustain an mTBI or injury have a long-term risk of additional mishaps. Differences shared among those who seek medical care for injuries may include risk-taking behaviors (Cherpitel, 1999; Turner & McClure, 2004; Turner, McClure, & Pirozzo, 2004), occupations, and differential participation in sports activities, among others. Individuals with an mTBI should be educated that they are at risk for subsequent injury. Historical data supported no lingering effects of mTBI, but more recent data suggest longer lasting effects. This study further adds that one of the longer term sequelae of mTBI may be an increased risk for subsequent mishap. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.
Enceladus Plumes: Causes of Decadal Variability
NASA Astrophysics Data System (ADS)
Ingersoll, Andrew P.; Ewald, Shawn P.
2016-10-01
The Enceladus plumes have decreased over the decade that Cassini has been observing them. This long-term variation is superposed on the much shorter-term variation tied to the position of Enceladus in its orbit around Saturn. The observations are ISS and VIMS images, which reveal the particles in the plumes but not the gas. The decadal variability largely consists of a 2-fold decline in the mass of plume material, but there is a hint of a recent turnaround. Here we offer three hypotheses, each with its strengths and weaknesses, to explain the long-term variability. The first is seasonal change, from summer to fall in the southern hemisphere. The loss of sunlight could increase the build-up of ice around the tiger stripes. The weakness is that the sunlight is likely to have a small effect, e.g., decreasing the sublimation rate of the ice by only ~1 cm/year. The second hypothesis is a statistical fluctuation in the number of active plumes, which tend to turn themselves off due to build-up of ice at the throat of the vent. The weakness is that the plumes are likely to fluctuate independently, and if there are ~100 plumes, their sum will only fluctuate by 10%. The third hypothesis is that the variation is part of a well-known decadal cycle of orbital eccentricity, which varies by ±2.5% around a mean of 0.0047. The peak eccentricity occurred in 2009-2010, and the minimum occurred in 2015. Since eccentricity controls the short-term orbital cycle variations, it could also control the longer-term decadal variations. The weakness is that the eccentricity variation is small, from 0.0046 to 0.0048. It is not certain that such a small variation could cause a 2-fold variation in the strength of the plumes. An independent study, still in its infancy, is the possibility that liquid water reaches the surface during part of the orbital cycle.
Solar variability: Implications for global change
NASA Technical Reports Server (NTRS)
Lean, Judith; Rind, David
1994-01-01
Solar variability is examined in search of implications for global change. The topics covered include the following: solar variation modification of global surface temperature; the significance of solar variability with respect to future climate change; and methods of reducing the uncertainty of the potential amplitude of solar variability on longer time scales.
Mechanisms Controlling Global Mean Sea Surface Temperature Determined From a State Estimate
NASA Astrophysics Data System (ADS)
Ponte, R. M.; Piecuch, C. G.
2018-04-01
Global mean sea surface temperature (T¯) is a variable of primary interest in studies of climate variability and change. The temporal evolution of T¯ can be influenced by surface heat fluxes (F¯) and by diffusion (D¯) and advection (A¯) processes internal to the ocean, but quantifying the contribution of these different factors from data alone is prone to substantial uncertainties. Here we derive a closed T¯ budget for the period 1993-2015 based on a global ocean state estimate, which is an exact solution of a general circulation model constrained to most extant ocean observations through advanced optimization methods. The estimated average temperature of the top (10-m thick) level in the model, taken to represent T¯, shows relatively small variability at most time scales compared to F¯, D¯, or A¯, reflecting the tendency for largely balancing effects from all the latter terms. The seasonal cycle in T¯ is mostly determined by small imbalances between F¯ and D¯, with negligible contributions from A¯. While D¯ seems to simply damp F¯ at the annual period, a different dynamical role for D¯ at semiannual period is suggested by it being larger than F¯. At periods longer than annual, A¯ contributes importantly to T¯ variability, pointing to the direct influence of the variable ocean circulation on T¯ and mean surface climate.
Stochastically-forced Decadal Variability in Australian Rainfall
NASA Astrophysics Data System (ADS)
Taschetto, A.
2015-12-01
Iconic Australian dry and wet periods were driven by anomalous conditions in the tropical oceans, such as the worst short-term drought in the southeast in 1982 associated with the strong El Niño and the widespread "Big Wet" in 1974 linked with a La Niña event. The association with oceanic conditions makes droughts predictable to some extent. However, prediction can be difficult when there is no clear external forcing such as El Niños. Can dry spells be triggered and maintained with no ocean memory? In this study, we investigate the potential role of internal multi-century atmospheric variability in controlling the frequency, duration and intensity of long-term dry and wet spells over Australia. Two multi-century-scale simulations were performed with the NCAR CESM: (1) a fully-coupled simulation (CPLD) and (2) an atmospheric simulation forced by a seasonal SST climatology derived from the coupled experiment (ACGM). Results reveal that droughts and wet spells can indeed be generated by internal variability of the atmosphere. Those internally generated events are less severe than those forced by oceanic variability, however the duration of dry and wet spells longer than 3 years is comparable with and without the ocean memory. Large-scale ocean modes of variability seem to play an important role in producing continental-scale rainfall impacts over Australia. While the Pacific Decadal Oscillation plays an important role in generating droughts in the fully coupled model, perturbations of monsoonal winds seem to be the main trigger of dry spells in the AGCM case. Droughts in the mid-latitude regions such as Tasmania can be driven by perturbations in the Southern Annular Mode, not necessarily linked to oceanic conditions even in the fully-coupled model. The mechanisms behind internally-driven mega-droughts and mega-wets will be discussed.
Estimating trends in the global mean temperature record
NASA Astrophysics Data System (ADS)
Poppick, Andrew; Moyer, Elisabeth J.; Stein, Michael L.
2017-06-01
Given uncertainties in physical theory and numerical climate simulations, the historical temperature record is often used as a source of empirical information about climate change. Many historical trend analyses appear to de-emphasize physical and statistical assumptions: examples include regression models that treat time rather than radiative forcing as the relevant covariate, and time series methods that account for internal variability in nonparametric rather than parametric ways. However, given a limited data record and the presence of internal variability, estimating radiatively forced temperature trends in the historical record necessarily requires some assumptions. Ostensibly empirical methods can also involve an inherent conflict in assumptions: they require data records that are short enough for naive trend models to be applicable, but long enough for long-timescale internal variability to be accounted for. In the context of global mean temperatures, empirical methods that appear to de-emphasize assumptions can therefore produce misleading inferences, because the trend over the twentieth century is complex and the scale of temporal correlation is long relative to the length of the data record. We illustrate here how a simple but physically motivated trend model can provide better-fitting and more broadly applicable trend estimates and can allow for a wider array of questions to be addressed. In particular, the model allows one to distinguish, within a single statistical framework, between uncertainties in the shorter-term vs. longer-term response to radiative forcing, with implications not only on historical trends but also on uncertainties in future projections. We also investigate the consequence on inferred uncertainties of the choice of a statistical description of internal variability. While nonparametric methods may seem to avoid making explicit assumptions, we demonstrate how even misspecified parametric statistical methods, if attuned to the important characteristics of internal variability, can result in more accurate uncertainty statements about trends.
NASA Astrophysics Data System (ADS)
Perner, Kerstin; Moros, Matthias; De Deckker, Patrick; Blanz, Thomas; Wacker, Lukas; Telford, Richard; Siegel, Herbert; Schneider, Ralph; Jansen, Eystein
2018-01-01
The Leeuwin Current (LC), an eastern boundary current, transports tropical waters from the Indo-Pacific Warm Pool (IPWP) towards southern latitudes and modulates oceanic conditions offshore southern Australia. New, high-resolution planktic foraminifer assemblage data and alkenone-derived sea surface temperatures (SST) provide an in-depth view on LC variability and mechanisms driving the current's properties during the mid to late Holocene (last c. 7.4 ka BP). Our marine reconstructions highlight a longer-term mid to late Holocene reduction of tropical heat export from the IPWP area into the LC. Mid Holocene (c. 7.4 to 3.5 ka BP) occurrence of high SSTs (>19.5 °C), tropical planktic foraminifera and a well-stratified water column document an enhanced heat export from the tropics. From c. 3.5 ka BP onwards, a weaker LC and a notably reduced tropical heat export cause oceanic cooling offshore southern Australia. The observed mid to late Holocene trends likely result from large-scale changes in the IPWP's heat storage linked to the El Niño-Southern Oscillation (ENSO) phenomenon. We propose that a strong and warm LC occurs in response to a La Niña-like state of ENSO during the mid Holocene. The late Holocene LC cooling, however, results from a shift towards an El Niño-like state and a more variable ENSO system that causes cooling of the IPWP. Superimposed on these longer-term trends we find evidence of distinct late Holocene millennial-scale phases of enhanced El Niño/La Niña development, which appear synchronous with northern hemispheric climatic variability. Phases of dominant El Niño-like states occur parallel to North Atlantic cold phases: the '2800 years BP cooling event', the 'Dark Ages' and the 'Little Ice Age', whereas the 'Roman Warm Period' and the 'Medieval Climate Anomaly' parallel periods of a predominant La Niña-like state. Our findings provide further evidence of coherent interhemispheric climatic and oceanic conditions during the mid to late Holocene, suggesting ENSO as a potential mediator.
Neighborhood Predictors of Cognitive Training Outcomes and Trajectories in ACTIVE
Meyer, Oanh L.; Sisco, Shannon M.; Harvey, Danielle; Zahodne, Laura B.; Glymour, M. Maria; Manly, Jennifer J.; Marsiske, Michael
2015-01-01
We examined the influence of neighborhood socioeconomic position (SEP), racial/ethnic composition, and living in a major city on cognitive trajectories and intervention outcomes. Data came from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study (N = 2,438). Mixed effects analyses examined associations between neighborhood variables and memory, reasoning, speed of processing, and everyday cognition, estimating differences in initial gains (potentially related to practice) and long-term rate of change over 10 years. The effect of reasoning training on initial gain was weaker for individuals in a major city. For everyday cognition, there was a stronger initial gain for memory-trained and control participants in areas with more racial/ethnic minorities, and for speed-trained and control individuals in higher SEP areas. The racial/ethnic minority effect was no longer significant after adjustment for multiple comparisons. Neighborhood factors may be more important in practice-related improvement than in long-term change. PMID:26667987
NASA Astrophysics Data System (ADS)
Uddameri, V.
2007-01-01
Reliable forecasts of monthly and quarterly fluctuations in groundwater levels are necessary for short- and medium-term planning and management of aquifers to ensure proper service of seasonal demands within a region. Development of physically based transient mathematical models at this time scale poses considerable challenges due to lack of suitable data and other uncertainties. Artificial neural networks (ANN) possess flexible mathematical structures and are capable of mapping highly nonlinear relationships. Feed-forward neural network models were constructed and trained using the back-percolation algorithm to forecast monthly and quarterly time-series water levels at a well that taps into the deeper Evangeline formation of the Gulf Coast aquifer in Victoria, TX. Unlike unconfined formations, no causal relationships exist between water levels and hydro-meteorological variables measured near the vicinity of the well. As such, an endogenous forecasting model using dummy variables to capture short-term seasonal fluctuations and longer-term (decadal) trends was constructed. The root mean square error, mean absolute deviation and correlation coefficient ( R) were noted to be 1.40, 0.33 and 0.77 m, respectively, for an evaluation dataset of quarterly measurements and 1.17, 0.46, and 0.88 m for an evaluative monthly dataset not used to train or test the model. These statistics were better for the ANN model than those developed using statistical regression techniques.
NASA Astrophysics Data System (ADS)
Messina, Sergio
2007-10-01
The results of a long-term UBV photometric monitoring of the red supergiant (RSG) star V424 Lac are presented. V424 Lac shows multiperiodic brightness variations which can be attributed to pulsational oscillations. A much longer period ( P = 1601 d), that allows us to classify this star as a long secondary period variable star (LSPV) has been also detected. The B - V and U - B color variations related to the long secondary period (LSP) are similar to those related to the shorter periods, supporting the pulsational nature of LSP. The long period brightness variation of V424 Lac is accompanied by a near-UV (NUV) excess, which was spectroscopically detected in a previous study [Massey, P., Plez, B., Levesque, E.M., et al., 2005. ApJ 634, 1286] and which is now found to be variable from photometry. On the basis of the results found for V424 Lac, the NUV excess recently found in a number of RSGs may be due not solely to circumstellar dust but may also have a contribution from a still undetected LSP variability.
[Trust-promoting variables in child-adult interaction].
Esser, M; Petermann, F
1985-01-01
As interpersonal trust is recognized as a central variable in child-psychotherapy, and as psychological research has not yet developed strategies to advance interpersonal trust, the question arose by which social behavior variables children's trust is determined in the interaction process between adults and children. After having developed a most concrete definition of trust in terms of social interaction behavior, everyday pedagogical interaction sequences involving adults and children were analyzed in order to identify behavioral elements or patterns of interaction conducive to trust. According to the hypotheses, the behavior classes "positive adult reaction", "adult trusting behavior" and the interaction pattern "positive adult response to child trusting behavior" were found as conducive to interpersonal trust in children. Furthermore the realisation of the pattern "alternation of trusting child behavior and positive adult behavior" for a longer period of interaction was identified as material to the foundation of interpersonal trust. The realisation of that pattern is encouraged by positive and permanent reinforcement of different child reactions by the adult and by the child's readiness to react trustfully to positive adult behavior.
Parental distress in response to childhood medical trauma: A mediation model.
Currie, Roseanne; Anderson, Vicki A; McCarthy, Maria C; Burke, Kylie; Hearps, Stephen Jc; Muscara, Frank
2018-04-01
This study explored the relationship between individual and family-level risk in predicting longer-term parental distress following their child's unexpected diagnosis of serious illness. A mediation model was tested, whereby parents' pre-existing psychosocial risk predicts longer-term posttraumatic stress symptoms, indirectly through parents' acute stress response. One hundred and thirty-two parents of 104 children participated. Acute stress response partially mediated the relationship between psychosocial risk and posttraumatic stress symptoms, with a moderate indirect effect ( r 2 = .20, P M = .56, p < .001). Findings demonstrated that cumulative psychosocial risk factors predispose parents to acute stress and longer-term posttraumatic stress symptoms, highlighting the need for psychosocial screening in this population.
NASA Astrophysics Data System (ADS)
Stackhouse, P. W.; Soja, A. J.; Zhang, T.; Mikovitz, J. C.
2013-12-01
In terms of global change, boreal regions are particularly important, because significant warming and change are already evident and significant future warming is predicted. Mean global air temperature has increased by 0.74°C in the last century, and temperatures are predicted to increase by 1.8°C to 4°C by 2090, depending on the Inter-governmental Panel on Climate Change (IPCC) scenario. Some of the greatest temperature increases are currently found in the Northern Eurasian winter and spring, which has led to longer growing seasons, increased potential evapotranspiration and extreme fire weather [Groisman et al., 2007]. In the Siberian Sayan, winter temperatures have already exceeded a 2090 Hadley Centre scenario (HadCM3GGa1) [Soja et al., 2007]. There is evidence of climate-induced change across the circumboreal in terms of increased infestations, alterations in vegetation and increased fire regimes (area burned, fire frequency, severity and number of extreme fire seasons). In this paper, we analyzed long-term surface radiation data sets from the NASA/GEWEX (Global Energy and Water Exchanges) Surface Radiation Budget data products, CERES Surface EBAF and SYN data products and also the available surface radiation measurements in the region. First, we show that during overlap years SRB and CERES data products agree very well in terms of anomalies and we'll use this fact to evaluate 30 years of satellite based estimates of the variability of downwelling SW parameters first corresponding to locations of surface measurements and then for the region as a whole. We also show the observed variability of other SW components such as the net SW and the albedo. Next we assess the variability of the downward and LW fluxes over time and compare these to variability observed in the surface temperature and other meteorological measurements. We assess anomalies on various spatial scales. Finally, we assess the correlation of this variability in specific locations to known fire events. Extreme fires burned in Sakha and Tuva in 2002 and 2004, respectively, and in contrast, a normal fire season burned in Sakha and Tuva in 1999 and 2002, respectively. For this reason, we focus on the fire season (April - September) for 1999, 2002, and 2004. We assess these data sets for evidence of relationships between the net radiative fluxes and fire onset as well as evidence for residual influence of the fires upon the radiative budgets.
NASA Astrophysics Data System (ADS)
Woods, Thomas N.; Eparvier, Francis G.; Harder, Jerald; Snow, Martin
2018-05-01
The solar spectral irradiance (SSI) dataset is a key record for studying and understanding the energetics and radiation balance in Earth's environment. Understanding the long-term variations of the SSI over timescales of the 11-year solar activity cycle and longer is critical for many Sun-Earth research topics. Satellite measurements of the SSI have been made since the 1970s, most of them in the ultraviolet, but recently also in the visible and near-infrared. A limiting factor for the accuracy of previous solar variability results is the uncertainties for the instrument degradation corrections, which need fairly large corrections relative to the amount of solar cycle variability at some wavelengths. The primary objective of this investigation has been to separate out solar cycle variability and any residual uncorrected instrumental trends in the SSI measurements from the Solar Radiation and Climate Experiment (SORCE) mission and the Thermosphere, Mesosphere, Ionosphere, Energetic, and Dynamics (TIMED) mission. A new technique called the Multiple Same-Irradiance-Level (MuSIL) analysis has been developed, which examines an SSI time series at different levels of solar activity to provide long-term trends in an SSI record, and the most common result is a downward trend that most likely stems from uncorrected instrument degradation. This technique has been applied to each wavelength in the SSI records from SORCE (2003 - present) and TIMED (2002 - present) to provide new solar cycle variability results between 27 nm and 1600 nm with a resolution of about 1 nm at most wavelengths. This technique, which was validated with the highly accurate total solar irradiance (TSI) record, has an estimated relative uncertainty of about 5% of the measured solar cycle variability. The MuSIL results are further validated with the comparison of the new solar cycle variability results from different solar cycles.
Westgate, John N; Wania, Frank
2011-10-15
Air mass origin as determined by back trajectories often aids in explaining some of the short-term variability in the atmospheric concentrations of semivolatile organic contaminants. Airsheds, constructed by amalgamating large numbers of back trajectories, capture average air mass origins over longer time periods and thus have found use in interpreting air concentrations obtained by passive air samplers. To explore some of their key characteristics, airsheds for 54 locations on Earth were constructed and compared for roundness, seasonality, and interannual variability. To avoid the so-called "pole problem" and to simplify the calculation of roundness, a "geodesic grid" was used to bin the back-trajectory end points. Departures from roundness were seen to occur at all latitudes and to correlate significantly with local slope but no strong relationship between latitude and roundness was revealed. Seasonality and interannual variability vary widely enough to imply that static models of transport are not sufficient to describe the proximity of an area to potential sources of contaminants. For interpreting an air measurement an airshed should be generated specifically for the deployment time of the sampler, especially when investigating long-term trends. Samples taken in a single season may not represent the average annual atmosphere, and samples taken in linear, as opposed to round, airsheds may not represent the average atmosphere in the area. Simple methods are proposed to ascertain the significance of an airshed or individual cell. It is recommended that when establishing potential contaminant source regions only end points with departure heights of less than ∼700 m be considered.
NASA Technical Reports Server (NTRS)
Molnar, Gyula; Susskind, Joel
2008-01-01
The AIRS instrument is currently the best space-based tool to simultaneously monitor the vertical distribution of key climatically important atmospheric parameters as well as surface properties, and has provided high quality data for more than 5 years. AIRS analysis results produced at the GODDARD/DAAC, based on Versions 4 & 5 of the AIRS retrieval algorithm, are currently available for public use. Here, first we present an assessment of interrelationships of anomalies (proxies of climate variability based on 5 full years, since Sept. 2002) of various climate parameters at different spatial scales. We also present AIRS-retrievals-based global, regional and 1x1 degree grid-scale "trend"-analyses of important atmospheric parameters for this 5-year period. Note that here "trend" simply means the linear fit to the anomaly (relative the mean seasonal cycle) time series of various parameters at the above-mentioned spatial scales, and we present these to illustrate the usefulness of continuing AIRS-based climate observations. Preliminary validation efforts, in terms of intercomparisons of interannual variabilities with other available satellite data analysis results, will also be addressed. For example, we show that the outgoing longwave radiation (OLR) interannual spatial variabilities from the available state-of-the-art CERES measurements and from the AIRS computations are in remarkably good agreement. Version 6 of the AIRS retrieval scheme (currently under development) promises to further improve bias agreements for the absolute values by implementing a more accurate radiative transfer model for the OLR computations and by improving surface emissivity retrievals.
NASA Astrophysics Data System (ADS)
Kinoshita, A. M.; Hale, B.; Hogue, T. S.
2012-12-01
Post-fire management decisions are guided by rainfall-runoff predictions, which ultimately influence downstream treatment and mitigation costs. The current study investigates evolving rainfall-runoff partitioning at the watershed scale over a two-year period after the 2010 Bull Fire which occurred in the southern Sequoia National Forest in California. Stage height was measured at five-minute intervals using pressure transducers, tipping buckets were installed for rainfall duration and intensity, and channel cross-sections were measured approximately every two months to detail sediment deposition or scour. We also utilize remotely sensed vegetation data to evaluate vegetation recovery in the studied watersheds and the corresponding relationship to storm runoff. Normalized Difference Vegetation Index (NDVI), a measure of vegetation greenness, is evaluated for its potential use as a key recovery indicator. Preliminary results focus on alterations in annual and seasonal precipitation and discharge relationships using in-situ data and Landsat NDVI values for the period of study. NDVI values are consistent with a comprehensive burn, with an acute decrease observed in the initial post-fire period. However, vegetation recovery is highly variable in the studied systems and influenced by shorter-term biomass pulses (grasses) while longer-term recovery of other species (chaparral and pine) is ongoing. Runoff ratios are elevated during early storms and show some recovery in the later part of the study period. The ability to accurately and confidently predict post-fire runoff and longer-term recovery is critical for monitoring values-at-risk, reducing mitigation costs, and improving warnings to downstream public communities.
NASA Technical Reports Server (NTRS)
Gu, Guojun; Adler, Robert F.; Huffman, George J.; Curtis, Scott
2006-01-01
Global and large regional rainfall variations and possible long-term changes are examined using the 26-year (1979-2004) GPCP monthly dataset (Adler et al., 2003). Our emphasis is to discriminate among variations due to ENSO, volcanic events, and possible long-term climate changes in the tropics. Although the global linear change of precipitation in the data set is near zero during the time period, an increase in tropical rainfall is noted, with a weaker decrease over northern hemisphere middle latitudes. Focusing on the tropics (25degS-25degN), the data set indicates an upward trend (0.06 mm/day/decade) and a downward trend (-0.02 mm/day/decade) over tropical ocean and land, respectively. This corresponds to an about 4.9% increase (ocean) and 1.6% decrease (land) during the entire 26-year time period. Techniques are applied to isolate and quantify variations due to ENSO and two major volcanic eruptions (El Chichon, March 1982; Pinatubo, June 1991) in order to examine longer time-scale changes. The ENSO events generally do not impact the tropical total rainfall, but, of course, induce significant anomalies with opposite signs over tropical land and ocean. The impact of the two volcanic eruptions is estimated to be about a 5% reduction in tropical rainfall over both land and ocean. A modified data set (with ENSO and volcano effects removed) retains the same approximate linear change slopes, but with reduced variance, thereby increasing the confidence levels associated with the long-term rainfall changes in the tropics 2
Gridneva, Zoya; Kugananthan, Sambavi; Hepworth, Anna R.; Tie, Wan J.; Lai, Ching T.; Ward, Leigh C.; Hartmann, Peter E.; Geddes, Donna T.
2016-01-01
Human milk (HM) components influence infant feeding patterns and nutrient intake, yet it is unclear how they influence gastric emptying (GE), a key component of appetite regulation. This study analyzed GE of a single breastfeed, HM appetite hormones/macronutrients and demographics/anthropometrics/body composition of term fully breastfed infants (n = 41, 2 and/or 5 mo). Stomach volumes (SV) were calculated from pre-/post-feed ultrasound scans, then repeatedly until the next feed. Feed volume (FV) was measured by the test-weigh method. HM samples were analyzed for adiponectin, leptin, fat, lactose, total carbohydrate, lysozyme, and total/whey/casein protein. Linear regression/mixed effect models were used to determine associations between GE/feed variables and HM components/infant anthropometrics/adiposity. Higher FVs were associated with faster (−0.07 [−0.10, −0.03], p < 0.001) GE rate, higher post-feed SVs (0.82 [0.53, 1.12], p < 0.001), and longer GE times (0.24 [0.03, 0.46], p = 0.033). Higher whey protein concentration was associated with higher post-feed SVs (4.99 [0.84, 9.13], p = 0.023). Longer GE time was associated with higher adiponectin concentration (2.29 [0.92, 3.66], p = 0.002) and dose (0.02 [0.01, 0.03], p = 0.005), and lower casein:whey ratio (−65.89 [−107.13, −2.66], p = 0.003). FV and HM composition influence GE and breastfeeding patterns in term breastfed infants. PMID:28036041
Compression set in gas-blown condensation-cured polysiloxane elastomers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Patel, Mogon; Chinn, Sarah; Maxwell, Robert S.
2010-12-01
Accelerated thermal ageing studies on foamed condensation cured polysiloxane materials have been performed in support of life assessment and material replacement programmes. Two different types of filled hydrogen-blown and condensation cured polysiloxane foams were tested; commercial (RTV S5370), and an in-house formulated polysiloxane elastomer (Silfoam). Compression set properties were investigated using Thermomechanical (TMA) studies and compared against two separate longer term ageing trials carried out in air and in dry inert gas atmospheres using compression jigs. Isotherms measured from these studies were assessed using time-temperature (T/t) superposition. Acceleration factors were determined and fitted to Arrhenius kinetics. For both materials, themore » thermo-mechanical results were found to closely follow the longer term accelerated ageing trials. Comparison of the accelerated ageing data in dry nitrogen atmospheres against field trial results showed the accelerated ageing trends over predict, however the comparison is difficult as the field data suffer from significant component to component variability. Of the long term ageing trials reported here, those carried out in air deviate more significantly from field trials data compared to those carried out in dry nitrogen atmospheres. For field return samples, there is evidence for residual post-curing reactions influencing mechanical performance, which would accelerate compression set. Multiple quantum-NMR studies suggest that compression set is not associated with significant changes in net crosslink density, but that some degree of network rearrangement has occurred due to viscoelastic relaxation as well as bond breaking and forming processes, with possible post-curing reactions at early times.« less
An atlas of exotic variability in IGR J17091-3624: a comparison with GRS 1915+105
NASA Astrophysics Data System (ADS)
Court, J. M. C.; Altamirano, D.; Pereyra, M.; Boon, C. M.; Yamaoka, K.; Belloni, T.; Wijnands, R.; Pahari, M.
2017-07-01
We performed an analysis of all Rossi X-ray Timing Explorer observations of the low-mass X-ray binary (LMXB) and black hole candidate IGR J17091-3624 during the 2011-2013 outburst of the source. By creating light curves, hardness-intensity diagrams and power density spectra of each observation, we have created a set of nine variability 'classes' that phenomenologically describe the range of types of variability seen in this object. We compare our set of variability classes to those established by Belloni et al. to describe the similar behaviour of the LMXB GRS 1915+105, finding that some types of variability seen in IGR J17091-3624 are not represented in data of GRS 1915+105. We also use all available X-ray data of the 2011-2013 outburst of IGR J17091-3624 to analyse its long-term evolution, presenting the first detection of IGR J17091-3624 above 150 keV as well as noting the presence of 're-flares' during the later stages of the outburst. Using our results, we place new constraints on the mass and distance of the object, and find that it accretes at ≲33 per cent of its Eddington limit. As such, we conclude that Eddington-limited accretion can no longer be considered a sufficient or necessary criterion for GRS 1915+105-like variability to occur in LMXBs.
The longer term experiences of parent training: a qualitative analysis.
Furlong, M; McGilloway, S
2015-09-01
Child conduct problems are a major public health priority. Group-based parenting programmes are popular in addressing such problems, but evidence for their longer-term effectiveness is limited. Moreover, process evaluations are rare and little is understood about the key facilitative and inhibitive factors associated with maintaining outcomes in the longer term. This study involved the use of qualitative methods as part of a larger process evaluation to explore the longer-term experiences of parents who participated in a randomized controlled trial (RCT) of the Incredible Years Parenting Programme (IYPP) in disadvantaged settings in Ireland. A series of one-to-one in-depth interviews was conducted with parents at 12- (n = 20) and 18-month follow-up (n = 8) and analysed using constructivist grounded theory. Most parents reported positive child behaviour despite several challenges, but a substantial subset reported periods of relapse in positive outcomes. A relapse in child behaviour was linked to relinquishing skills in stressful times, the negative influence of an unsupportive environment, and the perceived ineffectiveness of parenting skills. Resilience in implementing skills despite adversity, and the utilization of available social supports, were associated with the maintenance of positive outcomes. Strengthening resilience and social support capacities may be important factors in maintaining positive longer-term outcomes. Those who design, research and deliver parenting programmes might consider the possibility of including a relapse-prevention module and/or the provision of post-intervention supports for more vulnerable families. © 2014 John Wiley & Sons Ltd.
El-Jack, Seif S; Suwatchai, Pornratanarangsi; Stewart, James T; Ruygrok, Peter N; Ormiston, John A; West, Teena; Webster, Mark W I
2007-12-01
We sought to define clinical and angiographic variables that may predict patients and lesions at increased risk for distal embolism during percutaneous intervention (PCI), as assessed by debris retrieval from a distal-protection filter device. Distal thrombo- and atheroembolism may contribute to periprocedural myocardial necrosis during PCI, which may in turn affect long-term outcomes. Distal protection devices have been used to reduce this occurrence with variable outcomes depending on lesion and patient subsets. 194 consecutive patients in whom the FilterWire(R) device (FW) [Boston Scientific Corp., Natick, MA] was used for native coronary vessel (n =129) or vein graft (n = 65) PCI were studied. FW debris was visually analyzed using a semi-quantitative grading score. Patients with "significant" debris (particles > or = 1 mm diameter) were compared with those with "nonsignificant" debris (no debris or particles <1 mm) with respect to clinical (age, gender, coronary disease risk factors, clinical presentation, periprocedural medications), and angiographic (vessel treated, vessel size, lesion length, lesion characteristics, angiographic thrombus and TIMI flow before and after PCI) variables. Significant debris was retrieved in 55% of patients, more frequently from vein graft (69%) than native vessel lesions (48%, p = 0.006). No clinical characteristics predicted significant debris retrieval. Angiographic predictors of significant debris by multivariate analysis were longer stent length and final TIMI flow <3 (p = 0.009 and 0.007, respectively). Longer stent length, likely reflecting increased lesion length and plaque burden, predicted significant distal embolism during PCI in native vessel and vein graft lesions, as assessed by debris collected in a distal vascular protection device. This suggests that use of vascular protection devices should be considered during PCI of long lesions.
Catanzaro, Thomas E
2006-03-01
This article provides the reader with an appreciation of the diverse elements that go into a buy-sell, affiliation, or merger situation for veterinary practices. In the changing market place of American veterinary medicine, old paradigms no longer hold comfort. The generational differences are briefly explored herein as well as the new economic realities. A few examples are offered to illustrate just how much variability exists in the current business of veterinary medicine and the subsequent practice transitions needed to enhance value. Functioning models are explored, as well as affiliation and merger options. Practice valuation is discussed in general terms, referencing the cutting-edge factors. The six-point summary provides almost all practices a solid operational base for daily operations and succession planning.
Posttreatment Lyme disease syndrome.
Aucott, John N
2015-06-01
The prognosis following appropriate antibiotic treatment of early or late Lyme disease is favorable but can be complicated by persistent symptoms of unknown cause termed posttreatment Lyme disease syndrome (PTLDS), characterized by fatigue, musculoskeletal pain, and cognitive complaints that persist for 6 months or longer after completion of antibiotic therapy. Risk factors include delayed diagnosis, increased severity of symptoms, and presence of neurologic symptoms at time of initial treatment. Two-tier serologic testing is neither sensitive nor specific for diagnosis of PTLDS because of variability in convalescent serologic responses after treatment of early Lyme disease. Optimal treatment of PTLDS awaits more precise understanding of the pathophysiologic mechanisms involved in this illness and future treatment trials. Copyright © 2015 Elsevier Inc. All rights reserved.
Geographical and political predictors of emotion in the sounds of favorite baby names.
Whissell, Cynthia
2006-02-01
The top 5 favorite boys' and girls' names from each state of the USA in 2000 and 2003 were analyzed in terms of the emotional associations of their component sounds and sound pronounceability. These were significantly and variously correlated with a historical factor (year), geographic factors (compass directions), and a political factor (percentage of the popular vote cast for President Bush in 2004). The expected stereotypical sex differences were observed: girls' names were longer, more pleasant, less active, and easier to pronounce (p < .01). It was possible to predict emotional associations and pronounceability (R2 = .27-.48, p < .01) on the basis of historical, geographical, and political variables.
The Economic Effect of Competition in the Air Transportation Industry
NASA Technical Reports Server (NTRS)
Hubbard, H. B.
1972-01-01
The air transportation industry has been described as a highly-competitive, regulated oligopoly or as a price-regulated cartel with blocked entry, resulting in excessive service and low load factors. The current structure of the industry has been strongly influenced by the hypotheses that increased levels of competition are desirable per se, and that more competing carriers can be economically supported in larger markets, in longer haul markets, with lower unit costs, and with higher fare levels. An elementary application of competition/game theory casts doubt on the validity of these hypotheses, but rather emphasizes the critical importance of the short-term non-variable costs in determining economic levels of competition.
Robert W. Peck; Christine G. Niwa
2005-01-01
Microarthropod densities within late-successional coniferous forests thinned 16-41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent,...
12-Month Follow-Up of Fluoxetine and Cognitive Behavioral Therapy for Binge Eating Disorder
ERIC Educational Resources Information Center
Grilo, Carlos M.; Crosby, Ross D.; Wilson, G. Terence; Masheb, Robin M.
2012-01-01
Objective: The longer term efficacy of medication treatments for binge-eating disorder (BED) remains unknown. This study examined the longer term effects of fluoxetine and cognitive behavioral therapy (CBT) either with fluoxetine (CBT + fluoxetine) or with placebo (CBT + placebo) for BED through 12-month follow-up after completing treatments.…
ERIC Educational Resources Information Center
Yan, Chunmei
2008-01-01
This paper reports on a study that examines decisive factors for longer-term sustainability of cross-cultural teacher training initiatives in China. It focuses on teacher trainees' perspectives of a Sino-British adult education English language teaching project based in Central China. Questionnaires and semi-structured interviews were employed to…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gagné, Jonathan; Plavchan, Peter; Gao, Peter
2016-05-01
We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2–M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25–150 Myr) moving groups, the young field star ε Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8–15 m s{sup −1}with a long-term stability of 15–50 m s{sup −1} over longer baselines. We obtain the best NIR RVmore » constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25–50 m s{sup −1} at ≈2.3125 μ m, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3 σ –5 σ . Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s{sup −1} in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.« less
Effects of reaction time variability and age on brain activity during Stroop task performance.
Tam, Angela; Luedke, Angela C; Walsh, Jeremy J; Fernandez-Ruiz, Juan; Garcia, Angeles
2015-09-01
Variability in reaction time during task performance may reflect fluctuations in attention and cause reduced performance in goal-directed tasks, yet it is unclear whether the mechanisms behind this phenomenon change with age. Using fMRI, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying intra-individual reaction time variability. We found significant between-group differences in BOLD activity modulated by reaction time. In older adults, longer reaction times were associated with greater activity in frontoparietal attentional areas, while in younger adults longer reaction times were associated with greater activity in default mode network areas. Our results suggest that the neural correlates of reaction time variability change with healthy aging, reinforcing the concept of functional plasticity to maintain high cognitive function throughout the lifespan.
NASA Astrophysics Data System (ADS)
Saigo, Barbara Woodworth
The researcher collaborated with four high school biology teachers who had been involved for 2-1/2 years in a constructivism-based professional development experience that emphasized teaching for conceptual change and using classroom-based inquiry as a basis for making instructional decisions. The researcher and teachers designed a five-day instructional unit on biosystematics using two contrasting approaches, comprising the treatment variable. The "traditional" unit emphasized lecture, written materials, and some laboratory activities. The "constructivist" unit emphasized a specific, inquiry-based, conceptual change strategy and collaborative learning. The study used a quasi-experimental, factorial design to explore impact of instructional approach (the treatment variable) on student performance (the dependent variable) on repeated measures (three) of a biology concept test. Additional independent variables considered were gender, cumulative GPA, and the section in which students were enrolled. Scores on the biology concept test were compiled for the 3 constructivist sections (N = 44) and the 3 traditional sections (N = 42). Analysis of Covariance (ANCOVA) was applied. The main findings in regard to the primary research question were that instructional approach did not have a significant relationship to immediate post test scores or gain, but that one month after instruction students in the constructivist group demonstrated less loss of gain than those in the traditional group; i.e., their longer-term retention was greater. Also, GPA*instructional approach effects were detected for post-post-test gain. GPA and gender were significantly associated with pre-test, post-test, and post-post scores; however, in terms of change (gain) from pre-test to post-test and pre-test to post-post-test, GPA and gender were not significant effects. Section was a significant effect for all three tests, in terms of both score and gain. Gender*section effects were detected for post-test gain and post-post-test scores.
Haselhorst, Derek S.; Moreno, J. Enrique; Punyasena, Surangi W.
2013-01-01
Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1–3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen traps, therefore, also represent an underutilized means of monitoring the pollen productivity and reproductive behavior of moist tropical forests. PMID:23320089
Haselhorst, Derek S; Moreno, J Enrique; Punyasena, Surangi W
2013-01-01
Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1-3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen traps, therefore, also represent an underutilized means of monitoring the pollen productivity and reproductive behavior of moist tropical forests.
NICU management and outcomes of infants with trisomy 21 without major anomalies.
McAndrew, Sarah; Acharya, Krishna; Nghiem-Rao, T Hang; Leuthner, Steven; Clark, Reese; Lagatta, Joanne
2018-05-25
To describe how trisomy 21 affects neonatal intensive care management and outcomes of full-term infants without congenital anomalies. Retrospective cohort of full-term infants without anomalies with and without trisomy 21 admitted to Pediatrix NICUs from 2005 to 2012. We compared diagnoses, management, length of stay, and discharge outcomes. In all, 4623 infants with trisomy 21 and 606 770 infants without trisomy 21 were identified. One-third of infants in the NICU with and without trisomy 21 were full term without major anomalies. Trisomy 21 infants had more respiratory distress, thrombocytopenia, feeding problems, and pulmonary hypertension. They received respiratory support for a longer period of time and had a longer length of stay. One-third of infants with trisomy 21 admitted to the NICU are full term without major anomalies. Common diagnoses and greater respiratory needs place infants with trisomy 21 at risk for longer length of stay.
Agreement between ambulatory, home, and office blood pressure variability.
Juhanoja, Eeva P; Niiranen, Teemu J; Johansson, Jouni K; Puukka, Pauli J; Jula, Antti M
2016-01-01
Ambulatory, home, and office blood pressure (BP) variability are often treated as a single entity. Our aim was to assess the agreement between these three methods for measuring BP variability. Twenty-four-hour ambulatory BP monitoring, 28 home BP measurements, and eight office BP measurements were performed on 461 population-based or hypertensive participants. Five variability indices were calculated for all measurement methods: SD, coefficient of variation, maximum-minimum difference, variability independent of the mean, and average real variability. Pearson's correlation coefficients were calculated for indices measured with different methods. The agreement between different measurement methods on the diagnoses of extreme BP variability (participants in the highest decile of variability) was assessed with kappa (κ) coefficients. SBP/DBP variability was greater in daytime (coefficient of variation: 9.8 ± 2.9/11.9 ± 3.6) and night-time ambulatory measurements (coefficient of variation: 8.6 ± 3.4/12.1 ± 4.5) than in home (coefficient of variation: 4.4 ± 1.8/4.7 ± 1.9) and office (coefficient of variation: 4.6 ± 2.4/5.2 ± 2.6) measurements (P < 0.001/0.001 for all). Pearson's correlation coefficients for systolic/diastolic daytime or night-time ambulatory-home, ambulatory-office, and home-office variability indices ranged between 0.07-0.25/0.12-0.23, 0.13-0.26/0.03-0.22 and 0.13-0.24/0.10-0.19, respectively, indicating, at most, a weak positive (r < 0.3) relationship. The agreement between measurement methods on diagnoses of extreme SBP/DBP variability was only slight (κ < 0.2), with the κ coefficients for daytime and night-time ambulatory-home, ambulatory-office, and home-office agreement varying between-0.014-0.20/0.061-0.15, 0.037-0.18/0.082-0.15, and 0.082-0.13/0.045-0.15, respectively. Shorter-term and longer-term BP variability assessed by different methods of BP measurement seem to correlate only weakly with each other. Our study suggests that BP variability measured by different methods and timeframes may reflect different phenomena, not a single entity.
Solar Spectral Irradiance Changes During Cycle 24
NASA Technical Reports Server (NTRS)
Marchenko, Sergey; Deland, Matthew
2014-01-01
We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by approximately 0.6% +/- 0.2% around 265 nm. These changes gradually diminish to 0.15% +/- 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar "continuum." Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar "continuum," the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at lambda approximately or greater than 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.
Time estimation by patients with frontal lesions and by Korsakoff amnesics.
Mimura, M; Kinsbourne, M; O'Connor, M
2000-07-01
We studied time estimation in patients with frontal damage (F) and alcoholic Korsakoff (K) patients in order to differentiate between the contributions of working memory and episodic memory to temporal cognition. In Experiment 1, F and K patients estimated time intervals between 10 and 120 s less accurately than matched normal and alcoholic control subjects. F patients were less accurate than K patients at short (< 1 min) time intervals whereas K patients increasingly underestimated durations as intervals grew longer. F patients overestimated short intervals in inverse proportion to their performance on the Wisconsin Card Sorting Test. As intervals grew longer, overestimation yielded to underestimation for F patients. Experiment 2 involved time estimation while counting at a subjective 1/s rate. F patients' subjective tempo, though relatively rapid, did not fully explain their overestimation of short intervals. In Experiment 3, participants produced predetermined time intervals by depressing a mouse key. K patients underproduced longer intervals. F patients produced comparably to normal participants, but were extremely variable. Findings suggest that both working memory and episodic memory play an individual role in temporal cognition. Turnover within a short-term working memory buffer provides a metric for temporal decisions. The depleted working memory that typically attends frontal dysfunction may result in quicker turnover, and this may inflate subjective duration. On the other hand, temporal estimation beyond 30 s requires episodic remembering, and this puts K patients at a disadvantage.
NASA Astrophysics Data System (ADS)
Knapp, Alan; Smith, Melinda; Collins, Scott; Blair, John; Briggs, John
2010-05-01
Understanding and predicting the dynamics of ecological systems has always been central to Ecology. Today, ecologists recognize that in addition to natural and human-caused disturbances, a fundamentally different type of ecosystem change is being driven by the combined and cumulative effects of anthropogenic activities affecting earth's climate and biogeochemical cycles. This type of change is historically unprecedented in magnitude, and as a consequence, such alterations are leading to trajectories of change in ecological responses that differ radically from those observed in the past. Through both short- and long-term experiments, we have been trying to better understand the mechanisms and consequences of ecological change in grassland ecosystems likely to result from changes in precipitation regimes. We have manipulated a key resource for most grasslands (water) and modulators of water availability (temperature) in field experiments that vary from 1-17 years in duration, and used even longer-term monitoring data from the Konza Prairie LTER program to assess how grassland communities and ecosystems will respond to changes in water availability. Trajectories of change in aboveground net primary production (ANPP) in sites subjected to 17 years of soil water augmentation were strongly non-linear with a marked increase in the stimulation of ANPP after year 8 (from 25% to 65%). Lags in alterations in grassland community composition are posited to be responsible for the form of this trajectory of change. In contrast, responses in ANPP to chronic increases in soil moisture variability appear to have decreased over a 10-yr period of manipulation, although the net effects of more variable precipitation inputs were to reduce ANPP, alter the genetic structure of the dominant grass species, increase soil nitrogen availability and reduce soil respiration. The loss of sensitivity to increased resource variability was not reflected in adjacent plots where precipitation was manipulated for only a single year. And when similar short-term experimental manipulations of precipitation variability were conducted in more arid grasslands, responses in ANPP were opposite those in mesic grassland. This suggests that grassland responses to alterations in precipitation inputs may vary dramatically depending on the long-term hydrologic regime.
NASA Astrophysics Data System (ADS)
Somot, Samuel; Houpert, Loic; Sevault, Florence; Testor, Pierre; Bosse, Anthony; Durrieu de Madron, Xavier; Dubois, Clotilde; Herrmann, Marine; Waldman, Robin; Bouin, Marie-Noëlle; Cassou, Christophe
2015-04-01
The North-Western Mediterranean Sea is known as one of the only place in the world where open-sea deep convection occurs (often up to more than 2000m) with the formation of the Western Mediterranean Deep Water (WMDW). This phenomena is mostly driven by local preconditioning of the water column and strong buoyancy losses during Winter. At the event scale, the WMDW formation is characterized by different phases (preconditioning, strong mixing, restratification and spreading), intense air-sea interaction and strong meso-scale activity but, on a longer time scale, it also shows a large interannual variability and may be strongly affected by climate change with impact on the regional biogeochemistry. Therefore observing, simulating and understanding the long-term temporal variability of the North-Western Mediterranean deep water formation is still today a very challenging task. We try here to tackle those issues thanks to (1) a thorough reanalysis of past in-situ observations (CTD, Argo, surface and deep moorings, gliders) and (2) an ERA-Interim driven simulation using a recently-developed fully coupled Regional Climate System Model (CNRM-RCSM4, Sevault et al. 2014). The multi-decadal simulation (1979-2013) is designed to be temporally and spatially homogeneous with a realistic chronology, a high resolution representation of both the regional ocean and atmosphere, specific initial conditions, a long-term spin-up and a full ocean-atmosphere coupling without constraint at the air-sea interface. The observation reanalysis allows to reconstruct interannual time series of deep water formation indicators (ocean surface variables, mixed layer depth, surface of the convective area, dense water volumes and characteristics of the deep water). Using the observation-based indicators and the model outputs, the 34 Winters of the period 1979-2013 are analysed in terms of weather regimes, related Winter air-sea fluxes, ocean preconditioning, mixed layer depth, surface of the convective area, deep water formation rate and long-term evolution of the deep water hydrology.
NASA Astrophysics Data System (ADS)
Dilling, L.; Daly, M.; Travis, W.; Wilhelmi, O.; Klein, R.; Kenney, D.; Ray, A. J.; Miller, K.
2013-12-01
Recent reports and scholarship have suggested that adapting to current climate variability may represent a "no regrets" strategy for adapting to climate change. Filling "adaptation deficits" and other approaches that rely on addressing current vulnerabilities are of course helpful for responding to current climate variability, but we find here that they are not sufficient for adapting to climate change. First, following a comprehensive review and unique synthesis of the natural hazards and climate adaptation literatures, we advance six reasons why adapting to climate variability is not sufficient for adapting to climate change: 1) Vulnerability is different at different levels of exposure; 2) Coping with climate variability is not equivalent to adaptation to longer term change; 3) The socioeconomic context for vulnerability is constantly changing; 4) The perception of risk associated with climate variability does not necessarily promote adaptive behavior in the face of climate change; 5) Adaptations made to short term climate variability may reduce the flexibility of the system in the long term; and 6) Adaptive actions may shift vulnerabilities to other parts of the system or to other people. Instead we suggest that decision makers faced with choices to adapt to climate change must consider the dynamics of vulnerability in a connected system-- how choices made in one part of the system might impact other valued outcomes or even create new vulnerabilities. Furthermore we suggest that rather than expressing climate change adaptation as an extension of adaptation to climate variability, the research and practice communities would do well to articulate adaptation as an imperfect policy, with tradeoffs and consequences and that decisions be prioritized to preserve flexibility be revisited often as climate change unfolds. We then present the results of a number of empirical studies of decision making for drought in urban water systems in the United States to understand: a) the variety of actions taken; b) the limitations of actions available to water managers; and c) the effectiveness of actions taken to date. Time permitting, we briefly present the results of 3 in-depth case studies of drought response and current perception of preparedness with respect to future drought and climate change among urban water system managers. We examine the role of governance, system connectivity, public perceptions and other factors in driving decision making and outcomes.
A study on the changes in attractive force of magnetic attachments for overdenture.
Leem, Han-Wool; Cho, In-Ho; Lee, Jong-Hyuk; Choi, Yu-Sung
2016-02-01
Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients. Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet. Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (P<.05, r=.361). Reduction ratio of attractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (P<.05). Furthermore, 16.39% of total magnetic attachments showed detachment of keeper or assembly. Attractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed.
ERIC Educational Resources Information Center
Leckey, Yvonne; Hyland, Lynda; Hickey, Gráinne; Lodge, Anne; Kelly, Paul; Bywater, Tracey; Comiskey, Catherine; Donnelly, Michael; McGilloway, Sinéad
2016-01-01
Inappropriate, aggressive and disruptive behaviour in the classroom can be detrimental to child and teacher well-being. This study involved a longer-term evaluation of the "Incredible Years Teacher [Classroom Management]" programme (IYTP) undertaken mainly within disadvantaged schools in south-west Ireland. The IYTP is designed to…
The Future Is More than Just Tomorrow: Higher Education, the Economy and the Longer Term
ERIC Educational Resources Information Center
Crossick, Geoffrey
2010-01-01
In this commentary the author reflects on longer-term issues facing higher education in the context of recession and crisis in public finance. The views expressed are written from a personal perspective with the aim of stimulating and encouraging a wider and ongoing debate around the themes presented. The author draws upon the findings of three…
Resnick, Cory M; Vakilian, Pouya M; Kaban, Leonard B; Peacock, Zachary S
2017-04-01
To compare short-term outcomes and procedure times for intra-articular steroid injection (IASI) to the temporomandibular joint (TMJ) with and without the use of intraoperative image guidance for patients with juvenile idiopathic arthritis (JIA). This is a retrospective study of children with JIA who underwent TMJ IASI at Boston Children's Hospital (Boston, MA). Patients were divided into groups according to IASI technique: 1) "landmark" group if performed by an oral and maxillofacial surgeon using an anatomic landmark technique with no intraoperative image guidance or 2) "image-guided" group if performed by an interventional radiologist using intraoperative ultrasound and computed tomography. Predictor variables included IASI technique (landmark vs image guided), age, gender, JIA subtype, category of medications for arthritis, and presence of family history of autoimmune disease. Outcome variables were changes in patient-reported pain, maximal incisal opening (MIO), synovial enhancement ratio (ER), and total procedure time. Forty-five patients with 71 injected TMJs were included. Twenty-two patients with 36 injected TMJs were in the landmark group and 23 patients with 35 injected joints were in the image-guided group. There were no relevant differences in age, gender, family history of rheumatologic disease, or disease subtype between groups. There were no differences in resolution of pain (P = 1.00), increase in MIO (P = .975), or decrease in ER (P = .492) between groups, but procedure times averaged 49 minutes longer for the image-guided group (P < .008). There were no statistical differences in short-term outcomes, but procedure times were longer for the image-guided group. Although specific indications for the use of image guidance might exist, routine use of this procedure cannot be justified. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Volcanic Eruptions and Climate
NASA Technical Reports Server (NTRS)
LeGrande, Allegra N.; Anchukaitis, Kevin J.
2015-01-01
Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.
[Long-term results after multiple trauma with ISS ≥ 25. Outcome and predictors of quality of life].
Simmel, S; Drisch, S; Haag, S; Bühren, V
2013-09-01
The survival chances of multiple trauma patients have continually improved over the last decades; therefore, it is often not a question of whether a patient survives a severe accident but rather how the patient survives. In a retrospective study 127 patients were questioned regarding quality of life and health and possible influencing factors using the POLO chart an average of 70 months after suffering severe trauma (ISS Ø 35.6). The quality of life of severely injured patients is significantly reduced compared with the normal population even years after the trauma. In addition to four pretraumatic factors (older age, female gender, low education and previous illnesses) four posttraumatic variables (difficulties with authorities/institutions and unemployment as a consequence of the accident, long duration and subjectively inadequate treatment in hospital) were identified that have a negative impact on long-term quality of life. The self-reported quality of life after multiple trauma no longer permanently achieves the original level despite extensive rehabilitation measures. Post-traumatic factors have a greater impact on the long-term quality of life than the injury severity. A long-term care and specialized rehabilitation services are needed to improve outcome further.
Consumer health plan choice: current knowledge and future directions.
Scanlon, D P; Chernew, M; Lave, J R
1997-01-01
A keystone of the competitive strategy in health insurance markets is the assumption that "consumers" can make informed choices based on the costs and quality of competing health plans, and that selection effects are not large. However, little is known about how individuals use information other than price in the decision making process. This review summarizes the state of knowledge about how individuals make choices among health plans and outlines an agenda for future research. We find that the existing literature on health plan choice is no longer sufficient given the widespread growth and acceptance of managed care, and the increased proportion of consumers' income now going toward the purchase of health plans. Instead, today's environment of health plan choice requires better understanding of how plan attributes other than price influence plan choice, how other variables such as health status interact with plan attributes in the decision making process, and how specific populations differ from one another in terms of the sensitivity of their health plan choices to these different types of variables.
Respiratory symptoms among glass bottle workers--cough and airways irritancy syndrome?
Gordon, S B; Curran, A D; Fishwick, D; Morice, A H; Howard, P
1998-10-01
Glass bottle workers have been shown to experience an excess of respiratory symptoms. This work describes in detail the symptoms reported by a cohort of 69 symptomatic glass bottle workers. Symptoms, employment history and clinical investigations including radiology, spirometry and serial peak expiratory flow rate records were retrospectively analyzed from clinical records. The results showed a consistent syndrome of work-related eye, nose and throat irritation followed after a variable period by shortness of breath. The latent interval between starting work and first developing symptoms was typically 4 years (median = 4 yrs; range = 0-28). The interval preceding the development of dysponea was longer and much more variable (median = 16 yrs; range = 3-40). Spirometry was not markedly abnormal in the group but 57% of workers had abnormal serial peak expiratory flow rate charts. Workers in this industry experience upper and lower respiratory tract symptoms consistent with irritant exposure. The long-term functional significance of these symptoms should be formally investigated.
Predictors of outcome for cognitive behaviour therapy in binge eating disorder.
Lammers, Mirjam W; Vroling, Maartje S; Ouwens, Machteld A; Engels, Rutger C M E; van Strien, Tatjana
2015-05-01
The aim of this naturalistic study was to identify pretreatment predictors of response to cognitive behaviour therapy in treatment-seeking patients with binge eating disorder (BED; N = 304). Furthermore, we examined end-of-treatment factors that predict treatment outcome 6 months later (N = 190). We assessed eating disorder psychopathology, general psychopathology, personality characteristics and demographic variables using self-report questionnaires. Treatment outcome was measured using the bulimia subscale of the Eating Disorder Inventory 1. Predictors were determined using hierarchical linear regression analyses. Several variables significantly predicted outcome, four of which were found to be both baseline predictors of treatment outcome and end-of-treatment predictors of follow-up: Higher levels of drive for thinness, higher levels of interoceptive awareness, lower levels of binge eating pathology and, in women, lower levels of body dissatisfaction predicted better outcome in the short and longer term. Based on these results, several suggestions are made to improve treatment outcome for BED patients. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.
Kampshoff, C S; van Dongen, J M; van Mechelen, W; Schep, G; Vreugdenhil, A; Twisk, J W R; Bosmans, J E; Brug, J; Chinapaw, M J M; Buffart, Laurien M
2018-06-01
This study aimed to evaluate the long-term effectiveness and cost-effectiveness of high intensity (HI) versus low-to-moderate intensity (LMI) exercise on physical fitness, fatigue, and health-related quality of life (HRQoL) in cancer survivors. Two hundred seventy-seven cancer survivors participated in the Resistance and Endurance exercise After ChemoTherapy (REACT) study and were randomized to 12 weeks of HI (n = 139) or LMI exercise (n = 138) that had similar exercise types, durations, and frequencies, but different intensities. Measurements were performed at baseline (4-6 weeks after primary treatment), and 12 (i.e., short term) and 64 (i.e., longer term) weeks later. Outcomes included cardiorespiratory fitness, muscle strength, self-reported fatigue, HRQoL, quality-adjusted life years (QALYs) and societal costs. Linear mixed models were conducted to study (a) differences in effects between HI and LMI exercise at longer term, (b) within-group changes from short term to longer term, and (c) the cost-effectiveness from a societal perspective. At longer term, intervention effects on role (β = 5.9, 95% CI = 0.5; 11.3) and social functioning (β = 5.7, 95%CI = 1.7; 9.6) were larger for HI compared to those for LMI exercise. No significant between-group differences were found for physical fitness and fatigue. Intervention-induced improvements in cardiorespiratory fitness and HRQoL were maintained between weeks 12 and 64, but not for fatigue. From a societal perspective, the probability that HI was cost-effective compared to LMI exercise was 0.91 at 20,000€/QALY and 0.95 at 52,000€/QALY gained, mostly due to significant lower healthcare costs in HI exrcise. At longer term, we found larger intervention effects on role and social functioning for HI than for LMI exercise. Furthermore, HI exercise was cost-effective with regard to QALYs compared to LMI exercise. This study is registered at the Netherlands Trial Register [NTR2153 [ http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2153
Investigation on the possibility of extracting wave energy from the Texas coast
NASA Astrophysics Data System (ADS)
Haces-Fernandez, Francisco
Due to the great and growing demand of energy consumption in the Texas Coast area, the generation of electricity from ocean waves is considered very important. The combination of the wave energy with offshore wind power is explored as a way to increase power output, obtain synergies, maximize the utilization of assigned marine zones and reduce variability. Previously literature has assessed the wave energy generation, combined with wind in different geographic locations such as California, Ireland and the Azores Island. In this research project, the electric power generation from ocean waves on the Texas Coast was investigated, assessing its potential from the meteorological data provided by five buoys from National Data Buoy Center of the National Oceanic and Atmospheric Administration, considering the Pelamis 750 kW Wave Energy Converter (WEC) and the Vesta V90 3 MW Wind Turbine. The power output from wave energy was calculated for the year 2006 using Matlab, and the results in several locations were considered acceptable in terms of total power output, but with a high temporal variability. To reduce its variability, wave energy was combined with wind energy, obtaining a significant reduction on the coefficient of variation on the power output. A Matlab based interface was created to calculate power output and its variability considering data from longer periods of time.
Kistamás, Kornél; Hegyi, Bence; Váczi, Krisztina; Horváth, Balázs; Bányász, Tamás; Magyar, János; Szentandrássy, Norbert; Nánási, Péter P
2015-07-01
Profound changes in tissue redox potential occur in the heart under conditions of oxidative stress frequently associated with cardiac arrhythmias. Since beat-to-beat variability (short term variability, SV) of action potential duration (APD) is a good indicator of arrhythmia incidence, the aim of this work was to study the influence of redox changes on SV in isolated canine ventricular cardiomyocytes using a conventional microelectrode technique. The redox potential was shifted toward a reduced state using a reductive cocktail (containing dithiothreitol, glutathione, and ascorbic acid) while oxidative changes were initiated by superfusion with H2O2. Redox effects were evaluated as changes in "relative SV" determined by comparing SV changes with the concomitant APD changes. Exposure of myocytes to the reductive cocktail decreased SV significantly without any detectable effect on APD. Application of H2O2 increased both SV and APD, but the enhancement of SV was the greater, so relative SV increased. Longer exposure to H2O2 resulted in the development of early afterdepolarizations accompanied by tremendously increased SV. Pretreatment with the reductive cocktail prevented both elevation in relative SV and the development of afterdepolarizations. The results suggest that the increased beat-to-beat variability during an oxidative stress contributes to the generation of cardiac arrhythmias.
RAPID OPTICAL VARIABILITY IN BLAZAR S5 0716+71 DURING 2010 MARCH
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chandra, S.; Baliyan, K. S.; Ganesh, S.
We report rapid optical variability for the blazar S5 0716+71 during 2010 March 8-10 and 19-20 in the CCD observations made from Mt. Abu Infrared Observatory. The light curves are constructed for a duration longer than 3 hr each night, with very high temporal resolution ({approx}45 s in the R band). During 2010 March 8, the source smoothly decayed by about 0.15 mag in 2.88 hr, apart from a fast flicker lasting about 30 minutes. S5 0716+71 brightened during March 9 and 10, showing high activity, while it was relatively faint (>14 mag in the R band) albeit variable duringmore » March 19-20. During March 9 and 10, rapid flickers in the intensity modulated the long-term intra-night ({approx}3 hr) variations. The present observations suggest that the blazar S5 0716+71 showed night-to-night and intra-night variability at various timescales with a 100% duty cycle for variation along with microvariability at significant levels. On a night-to-night basis, the source exhibits mild bluer-when-brighter nature. The interaction of shocks with local inhomogeneities in the jet appears to cause intra-night variations, while microvariations could be due to small-scale perturbations intrinsic to the jet.« less
Shakouri, Mahmoud; Ikuma, Laura H; Aghazadeh, Fereydoun; Punniaraj, Karthy; Ishak, Sherif
2014-10-01
This paper investigates the effect of changing work zone configurations and traffic density on performance variables and subjective workload. Data regarding travel time, average speed, maximum percent braking force and location of lane changes were collected by using a full size driving simulator. The NASA-TLX was used to measure self-reported workload ratings during the driving task. Conventional lane merge (CLM) and joint lane merge (JLM) were modeled in a driving simulator, and thirty participants (seven female and 23 male), navigated through the two configurations with two levels of traffic density. The mean maximum braking forces was 34% lower in the JLM configuration, and drivers going through the JLM configuration remained in the closed lane longer. However, no significant differences in speed were found between the two merge configurations. The analysis of self-reported workload ratings show that participants reported 15.3% lower total workload when driving through the JLM. In conclusion, the implemented changes in the JLM make it a more favorable merge configuration in both high and low traffic densities in terms of optimizing traffic flow by increasing the time and distance cars use both lanes, and in terms of improving safety due to lower braking forces and lower reported workload. Copyright © 2014 Elsevier Ltd. All rights reserved.
Grosso, Giuseppe; Micek, Agnieszka; Godos, Justyna; Pajak, Andrzej; Sciacca, Salvatore; Bes-Rastrollo, Maira; Galvano, Fabio; Martinez-Gonzalez, Miguel A
2017-08-17
To perform a dose-response meta-analysis of prospective cohort studies investigating the association between long-term coffee intake and risk of hypertension. An online systematic search of studies published up to November 2016 was performed. Linear and non-linear dose-response meta-analyses were conducted; potential evidence of heterogeneity, publication bias, and confounding effect of selected variables were investigated through sensitivity and meta-regression analyses. Seven cohorts including 205,349 individuals and 44,120 cases of hypertension were included. In the non-linear analysis, there was a 9% significant decreased risk of hypertension per seven cups of coffee a day, while, in the linear dose-response association, there was a 1% decreased risk of hypertension for each additional cup of coffee per day. Among subgroups, there were significant inverse associations for females, caffeinated coffee, and studies conducted in the US with longer follow-up. Analysis of potential confounders revealed that smoking-related variables weakened the strength of association between coffee consumption and risk of hypertension. Increased coffee consumption is associated with a modest decrease in risk of hypertension in prospective cohort studies. Smoking status is a potential effect modifier on the association between coffee consumption and risk of hypertension.
Modelling survival: exposure pattern, species sensitivity and uncertainty
Ashauer, Roman; Albert, Carlo; Augustine, Starrlight; Cedergreen, Nina; Charles, Sandrine; Ducrot, Virginie; Focks, Andreas; Gabsi, Faten; Gergs, André; Goussen, Benoit; Jager, Tjalling; Kramer, Nynke I.; Nyman, Anna-Maija; Poulsen, Veronique; Reichenberger, Stefan; Schäfer, Ralf B.; Van den Brink, Paul J.; Veltman, Karin; Vogel, Sören; Zimmer, Elke I.; Preuss, Thomas G.
2016-01-01
The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans. PMID:27381500
Estimation of Atlantic-Mediterranean netflow variability
NASA Astrophysics Data System (ADS)
Guerreiro, Catarina; Peliz, Alvaro; Miranda, Pedro
2016-04-01
The exchanges at the Strait of Gibraltar are extremely difficult to measure due to the strong temporal and across-strait variabilities; yet the Atlantic inflow into the Mediterranean is extremely important both for climate and to ecosystems. Most of the published numerical modeling studies do not resolve the Strait of Gibraltar realistically. Models that represent the strait at high resolution focus primarily in high frequency dynamics, whereas long-term dynamics are studied in low resolution model studies, and for that reason the Strait dynamics are poorly resolved. Estimating the variability of the exchanges requires long term and high-resolutions studies, thus an improved simulation with explicit and realistic representation of the Strait is necessary. On seasonal to inter-annual timescales the flow is essentially driven by the net evaporation contribution and consequently realistic fields of precipitation and evaporation are necessary for model setup. A comparison between observations, reanalysis and combined products shows ERA-Interim Reanalysis has the most suitable product for Mediterranean Sea. Its time and space variability are in close agreement with NOC 1.1 for the common period (1980 - 1993) and also with evaporation from OAFLUX (1989 - 2014). Subinertial fluctuations, periods from days to a few months, are the second most energetic, after tides, and are the response to atmospheric pressure fluctuations and local winds. Atmospheric pressure fluctuations in the Mediterranean cause sea level oscillations that induce a barotropic flow through the Strait. Candela's analytical model has been used to quantify this response in later studies, though comparison with observations points to an underestimation of the flow at strait. An improved representation of this term contribution to the Atlantic - Mediterranean exchange must be achieved on longer time-scales. We propose a new simulation for the last 36 years (1979 - 2014) for the Mediterranean - Atlantic domain with explicit representation of the Strait. The simulations are performed using the Regional Ocean Modeling System (ROMS) and forced with the different contributions of the freshwater budget, sea level pressure fluctuations and winds from ERA-Interim Reanalysis. The model of sea level pressure induced barotropic fluctuations simulates the barotropic variability at the Strait of Gibraltar for the last decades.
Personality and long term exposure to organic solvents
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lindstroem, K.; Martelin, T.
1980-01-01
Personality, especially emotional reactions of two solvent exposed groups and a nonexposed reference group were described by means of 20 formal, content and check-list type of Rorschach variables. Another objective of the study was to explore the suitability and psychological meaning of other types of Rorschach variables than those applied earlier in the field of behavioral toxicology. The factor analyses grouped the applied variables into factors of Productivity, Ego Strength, Control of Emotionality, Defensive Introversion and Aggressiveness. One solvent group, a patient groups (N.53), was characterized by a high number of Organic signs and a low Genetic Level, indicating possiblemore » psychoorganic deterioration. The other solvent group, styrene exposed but subjectively healthy (N.98), was characterized by few emotional reactions, low Anxiety and a low number of Neurotic Signs. the long duration of exposure of the solvent patient group (mean 10.2 +/- 8.7 years) was related to variables of the Productivity factor, a finding that indicates a possible better adjustment of those exposed for a longer time. The duration of exposure of the styrene exposed group (mean 4.9 +/- 3.2 years) revealed a very slight relation to personality variables, but the mean urinary mandelic acid concentration, indicating the level of styrene exposure, correlated with increased emotional reactions. For the most part definite causal conclusions could not be drawn because of the cross-sectional design of the study.« less
NASA Astrophysics Data System (ADS)
Cook, B.; Williams, P.; Mankin, J. S.; Seager, R.; Smerdon, J. E.; Singh, D.
2017-12-01
Coastal droughts simultaneously affecting California, Oregon, and Washington are rare, but have extensive and severe impacts (e.g., wildfire, agriculture). To better understand these events, we use historical observations to investigate: (1) drought variability along the Pacific Coast of the Contiguous United States and (2) years when extreme drought affects the entire coast. The leading pattern of cold-season (October-March) precipitation variability along the Pacific Coast favors spatially coherent moisture anomalies, accounts for >40% of the underlying variance, and is forced primarily by internal atmospheric dynamics. This contrasts with a much weaker dipole mode ( 20% of precipitation variability) characterized by anti-phased moisture anomalies across 40N and strong correlations with tropical Pacific sea surface temperatures (SSTs). Sixteen coastal-wide summer droughts occurred from 1895-2016 (clustering in the 1920s-1930s and post-2000), events most strongly linked with the leading precipitation mode and internal atmospheric variability. The frequency of landfalling atmospheric rivers south of 40N is sharply reduced during coastal droughts, but not north of this boundary where their frequency is more strongly influenced by the dipole. The lack of a consistent pattern of SST forcing during coastal droughts suggests little potential for skillful predictions of these events at the seasonal scale. However, their tendency to cluster in time and the impact of warming during recent droughts may help inform decadal and longer-term drought risks.
NASA Technical Reports Server (NTRS)
Roberts, J. Brent; Robertson, Franklin R.; Funk, Chris
2014-01-01
Providing advance warning of East African rainfall variations is a particular focus of several groups including those participating in the Famine Early Warming Systems Network. Both seasonal and long-term model projections of climate variability are being used to examine the societal impacts of hydrometeorological variability on seasonal to interannual and longer time scales. The NASA / USAID SERVIR project, which leverages satellite and modeling-based resources for environmental decision making in developing nations, is focusing on the evaluation of both seasonal and climate model projections to develop downscaled scenarios for using in impact modeling. The utility of these projections is reliant on the ability of current models to capture the embedded relationships between East African rainfall and evolving forcing within the coupled ocean-atmosphere-land climate system. Previous studies have posited relationships between variations in El Niño, the Walker circulation, Pacific decadal variability (PDV), and anthropogenic forcing. This study applies machine learning methods (e.g. clustering, probabilistic graphical model, nonlinear PCA) to observational datasets in an attempt to expose the importance of local and remote forcing mechanisms of East African rainfall variability. The ability of the NASA Goddard Earth Observing System (GEOS5) coupled model to capture the associated relationships will be evaluated using Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations.
Reproductive decision-making and determinants of contraceptive use in HIV-infected women.
Williams, H A; Watkins, C E; Risby, J A
1996-06-01
Perinatal transmission and reproductive decisions of HIV-infected women can be categorized in statistical and epidemiological terms. These reports and figures, however, do little to fully explain the complexities of human relationships, life experiences, personal and cultural influences, and situational and environmental variables that impact on the HIV-infected woman regarding reproductive decision-making. It is only with genuine attempts to understand the woman's perspective and the dynamic and unique variables that influence reproductive decision-making, as well as maintaining a non-judgmental and culturally sensitive perspective, can we hope to assist women, and society as a whole, in coming to terms with the complexities of HIV and reproductive decision-making. Further study is needed to identify factors that influence reproductive decision-making in HIV-infected women. The determinants of contraceptive use regarding demographic factors, barriers to contraceptive use, and factors that contribute to successful contraceptive use in this population must be understood if efforts to reduce the number of unplanned pregnancies are to be successful. More conclusive data are needed on the safety and efficacy of oral contraceptives in HIV-infected women as well as data that describe the effects of longer acting hormonal contraceptives such as levonorgestrel implants (Norplant; Wyeth-Ayerst, Philadelphia, PA) and injectable medroxyprogesterone acetate (Depo Provera; Upjohn Company, Kalamazoo, MI). More research is needed to determine the effects of patient education and counseling and closer follow-up on effective long-term contraception in HIV-infected women.
Tonsillectomy Versus Watchful Waiting for Recurrent Throat Infection: A Systematic Review
Morad, Anna; Sathe, Nila A.; Francis, David O.; McPheeters, Melissa L.
2017-01-01
CONTEXT: The effectiveness of tonsillectomy or adenotonsillectomy (“tonsillectomy”) for recurrent throat infection compared with watchful waiting is uncertain. OBJECTIVE: To compare sleep, cognitive, behavioral, and health outcomes of tonsillectomy versus watchful waiting in children with recurrent throat infections. DATA SOURCES: MEDLINE, Embase, and the Cochrane Library. STUDY SELECTION: Two investigators independently screened studies against predetermined criteria. DATA EXTRACTION: One investigator extracted data with review by a second. Investigators independently assessed risk of bias and strength of evidence (SOE) and confidence in the estimate of effects. RESULTS: Seven studies including children with ≥3 infections in the previous 1 to 3 years addressed this question. In studies reporting baseline data, number of infections/sore throats decreased from baseline in both groups, with greater decreases in sore throat days, clinician contacts, diagnosed group A streptococcal infections, and school absences in tonsillectomized children in the short term (<12 months). Quality of life was not markedly different between groups at any time point. LIMITATIONS: Few studies fully categorized infection/sore throat severity; attrition was high. CONCLUSIONS: Throat infections, utilization, and school absences improved in the first postsurgical year in tonsillectomized children versus children not receiving surgery. Benefits did not persist over time; longer-term outcomes are limited. SOE is moderate for reduction in short-term throat infections and insufficient for longer-term reduction. SOE is low for no difference in longer-term streptococcal infection reduction. SOE is low for utilization and missed school reduction in the short term, low for no difference in longer-term missed school, and low for no differences in quality of life. PMID:28096515
Tonsillectomy Versus Watchful Waiting for Recurrent Throat Infection: A Systematic Review.
Morad, Anna; Sathe, Nila A; Francis, David O; McPheeters, Melissa L; Chinnadurai, Sivakumar
2017-02-01
The effectiveness of tonsillectomy or adenotonsillectomy ("tonsillectomy") for recurrent throat infection compared with watchful waiting is uncertain. To compare sleep, cognitive, behavioral, and health outcomes of tonsillectomy versus watchful waiting in children with recurrent throat infections. MEDLINE, Embase, and the Cochrane Library. Two investigators independently screened studies against predetermined criteria. One investigator extracted data with review by a second. Investigators independently assessed risk of bias and strength of evidence (SOE) and confidence in the estimate of effects. Seven studies including children with ≥3 infections in the previous 1 to 3 years addressed this question. In studies reporting baseline data, number of infections/sore throats decreased from baseline in both groups, with greater decreases in sore throat days, clinician contacts, diagnosed group A streptococcal infections, and school absences in tonsillectomized children in the short term (<12 months). Quality of life was not markedly different between groups at any time point. Few studies fully categorized infection/sore throat severity; attrition was high. Throat infections, utilization, and school absences improved in the first postsurgical year in tonsillectomized children versus children not receiving surgery. Benefits did not persist over time; longer-term outcomes are limited. SOE is moderate for reduction in short-term throat infections and insufficient for longer-term reduction. SOE is low for no difference in longer-term streptococcal infection reduction. SOE is low for utilization and missed school reduction in the short term, low for no difference in longer-term missed school, and low for no differences in quality of life. Copyright © 2017 by the American Academy of Pediatrics.
Garzetti, G G; Ciavattini, A; De Cristofaro, F; La Marca, N; Arduini, D
1997-01-01
This study was designed to: (i) evaluate the effect of amnioinfusion on the latency period in patients with oligohydramnios for preterm premature rupture of membranes, and (ii) to investigate the relationship between changes in the amniotic fluid index and fetal heart rate short-term variability by computerized Hewlett-Packard cardiotocography, longitudinally estimated before and after prophylactic amnioinfusion. All singleton pregnancies with prolonged premature rupture of membranes after 25 weeks of gestation and seen at the Institute of Obstetrics and Gynecology, University of Ancona (Italy), between January 1994 and June 1995 were included in the study. Transabdominal amnioinfusion with 150-350 ml warmed normal saline (25-50 ml/min) was performed at weekly intervals. Amniotic fluid volume was assessed ultrasonographically by means of the four-quadrant technique on a weekly basis before and after each amnioinfusion, as well as the short-term variability by a Hewlett-Packard computerized cardiotocographic system. 18 women were enrolled and underwent prophylactic transabdominal amnioinfusion at weekly intervals until delivery. Eighteen controls, who did not undergo prophylactic amnioinfusion, were recruited from our 1992-1993 series and included in the study. The median interval between premature rupture of membranes and delivery was 3.0 weeks (range 1-8 weeks), with an average delivery age of 33.0 weeks (range 27-36 weeks). The latency period was significantly longer in patients who underwent prophylactic amnioinfusion (mean +/- SD, 4.1 +/- 1.7 weeks) than in controls(1.7 +/- 1.0 weeks; p < 0.001). An increase in both the weekly amniotic fluid index (linear regression analysis r = 0.8, p = 0.03) and the weekly short-term variability (linear regression analysis r = 0.82, p = 0.02) was observed among patients who underwent prophylactic amnioinfusion. A direct relationship was observed between the amniotic fluid index and short-term variability (linear regression analysis r = 0.54, p = 0.04). The mean values of fetal movements recorded by computerized tomography during the 20 min of observation significantly increased after amnioinfusion in comparison with those before it (2.6 +/- 0.9 and 0.9 +/- 0.7 respectively; p = 0.001). The present study has shown a positive effect of prophylactic transabdominal amnioinfusion on the latency period in patients with preterm premature rupture of membranes and oligohydramnios. Among the patients who underwent amnioinfusion, an interesting improvement in fetal heart rate short-term variability was associated with the progressive increase in amniotic fluid volume, as an expression of fetal well-being.
Choi, Woneui; Jeong, Heejeong; Choi, Suk-Joo; Kim, Jung-Sun; Roh, Cheong-Rae; Kim, Jong-Hwa
2015-01-01
Objective The aim of this study was to compare the risk factors associated with mild/moderate meconium aspiration syndrome (MAS) with those associated with severe in meconium-stained term neonates. Methods Consecutive singleton term neonates (n=671) with meconium staining at birth from all deliveries (n=14,666) in our institution from January 2006 to December 2012 were included. Both maternal and neonatal variables were examined. Among the study population, for women who underwent the trial of labor (n=644), variables associated with labor were also examined. These variables were compared between the mild/moderate MAS group, the severe MAS group, and the MAS-absent group. Results MAS developed in 10.6% (71/671) of neonates with meconium staining at birth. Among the neonates with MAS, 81.7% had mild MAS, 5.6% had moderate MAS, and 12.7% had severe MAS. The presence of minimal variability was significantly increased in both the mild/moderate and the severe MAS groups. The frequencies of nulliparity, fetal tachycardia, and intrapartum fever were significantly increased in the mild/moderate MAS group, but not in the severe MAS group. While a longer duration of the second stage of labor was significantly associated with mild/moderate MAS, severe MAS was associated with a shorter duration of the second stage. Notably, low mean cord pH (7.165 [6.850-7.375]) was significantly associated with mild/moderate MAS, but not with severe MAS (7.220 [7.021-7.407]) compared with the absence of MAS (7.268 [7.265-7.271]). Conclusion Our data suggest the development of severe MAS is not simply a linear extension of the same risk factors driving mild/moderate MAS. PMID:25629015
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guard-Petter, J.; Parker, C.T.; Asokan, K.
1999-05-01
Twelve human and chicken isolates of Salmonella enterica serovar Enteritidis belonging to phage types 4, 8, 13a, and 23 were characterized for variability in lipopolysaccharide (LPS) composition. Isolates were differentiated into two groups, i.e., those that lacked immunoreactive O-chain, termed rough isolates, and those that had immunoreactive O-chain, termed smooth isolates. Isolates within these groups could be further differentiated by LPS compositional differences as detected by gel electrophoresis and gas liquid chromatography of samples extracted with water, which yielded significantly more LPS in comparison to phenol-chloroform extraction. The rough isolates were of two types, the O-antigen synthesis mutants and themore » O-antigen polymerization (wzy) mutants. Smooth isolates were also of two types, one producing low-molecular-weight (LMW) LPS and the other producing high-molecular-weight (HMW) LPS. To determine the genetic basis for the O-chain variability of the smooth isolates, the authors analyzed the effects of a null mutation in the O-chain length determinant gene, wzz (cld) of serovar Typhimurium. This mutation results in a loss of HMW LPS; however, the LMW LPS of this mutant was longer and more glucosylated than that from clinical isolates of serovar Enteritidis. Cluster analysis of these data and of those from two previously characterized isogenic strains of serovar Enteritidis that had different virulence attributes indicated that glucosylation of HMW LPS (via oafR function) is variable and results in two types of HMW structures, one that is highly glucosylated and one that is minimally glucosylated. These results strongly indicate that naturally occurring variability in wzy, wzz, and oafR function can be used to subtype isolates of serovar Enteritidis during epidemiological investigations.« less
Shahab, Lion; Beard, Emma; Brown, Jamie; West, Robert
2014-01-01
Nicotine replacement therapy (NRT) is used by smokers wanting to reduce their smoking and to quit. However, there are very little data on nicotine intake associated with NRT use in representative population samples. This study aimed to provide estimates for NRT use and associated nicotine exposure among smokers, recent and longer-term ex-smokers in England, a country with a permissive regulatory regime for nicotine substitution. In the Smoking Toolkit Study, a monthly series of representative household surveys of adults aged 16+ in England, current and recent ex-smokers who agreed to be re-contacted were followed up 6 months later and standard socio-demographic and smoking characteristics assessed (N = 5,467, response rate 25.1%). A random sub-sample (N = 1,614; 29.5%) also provided saliva, analysed for cotinine. The sample followed up was broadly representative of the original sample. At follow-up, 11.8% (95%CI 10.9-12.8, N = 565) of current smokers, 34.8% (95%CI 28.9-41.3, N = 77) of recent (≤ 3 months) ex-smokers, and 7.8% (95%CI 5.6-10.6, N = 36) of longer-term (> 3 months) ex-smokers reported using NRT. Smokers who used NRT had similar saliva cotinine concentrations to smokers who did not use NRT (mean ± sd = 356.0 ± 198.6 ng/ml vs. 313.1 ± 178.4 ng/ml). Recent ex-smokers who used NRT had levels that were somewhat lower, but not significantly so, than current smokers (216.7 ± 179.3 ng/ml). Longer-term ex-smokers using NRT had still lower levels (157.3 ± 227.1 ng/ml), which differed significantly from smokers using NRT (p = 0.024). Concurrent use of nicotine replacement therapy while smoking is relatively uncommon and is not associated with higher levels of nicotine intake. Among ex-smokers, NRT use is common in the short but not longer-term and among longer-term users is associated with lower nicotine intake than in smokers.
Jackson, A.; Persaud, C; Hall, M; Smith, S; Evans, N; Rutter, N
1997-01-01
Urinary 5-L-oxoproline was measured in term and preterm infants from shortly after birth until 6 weeks of postnatal age to determine their ability to synthesise glycine. In term infants the excretion was five to 10 times that seen in normal adults, increasing from 105 µmol/mmol creatinine in the first 72 hours after birth to 170 µmol/mmol creatinine at 6 weeks of age. There was a significant inverse linear correlation between the excretion of 5-L-oxoproline and length of gestation or birthweight. By 6 weeks of age there was no longer a significant difference in 5-L-oxoproline between term and preterm infants. There was no difference in the excretion of 5-L-oxoproline between boys and girls, or between infants fed on human milk or an artificial formula. If, in part, variability in the excretion of 5-L-oxoproline is determined by the extent to which the endogenous formation of glycine is adequate, then glycine formation may be marginal during early life, more so in preterm than in term infants, providing additional evidence that glycine is a conditionally essential amino acid in the neonate. Keywords: glycine; γ-glutamyl cycle; protein synthesis; conditionally essential amino acids PMID:9175943
Chan, Christian S; Lowe, Sarah R; Weber, Elyssa; Rhodes, Jean E
2015-08-01
A previous study of Hurricane Katrina survivors found that higher levels of predisaster social support were associated with lower psychological distress one year after the storm, and that this pathway was mediated by lower exposure to hurricane-related stressors. As a follow-up, we examined the impact of pre- and postdisaster social support on longer-term of mental health-both psychological distress and posttraumatic stress. In this three-wave longitudinal study, 492 residents in the region affected by Hurricane Katrina reported levels of perceived social support and symptoms of psychological distress prior to the storm (Wave 1). Subsequently, one year after Hurricane Katrina (Wave 2), they reported levels of exposure, perceived social support, and symptoms of psychological distress and posttraumatic stress. The latter three variables were assessed again four years after the hurricane (Wave 3). Results of mediation analysis indicated that levels of exposure to hurricane-related stressors mediated the relationship between Wave 1 perceived social support and Wave 3 psychological distress as well as postdisaster posttraumatic stress. Results of regression analyses indicated that, controlling for Wave 1 psychological distress and disaster exposure, Wave 2 perceived social support was associated with Wave 2 and Wave 3 psychological distress but not posttraumatic stress. Our results confirmed the social causation processes of social support and suggest that posttraumatic stress might not stem directly from the lack of social support. Rather, preexisting deficits in social resources might indirectly affect longer-term posttraumatic stress and general psychological distress by increasing risk for disaster-related stressors. Copyright © 2015 Elsevier Ltd. All rights reserved.
Buoli, Massimiliano; Dell'osso, Bernardo; Zaytseva, Yuliya; Gurovich, Isaac Ya; Movina, Larisa; Dorodnova, Anna; Shmuckler, Alexander; Altamura, A Carlo
2013-12-01
Several studies show an association between a long duration of untreated illness (DUI) and poor outcome in schizophrenic patients. DUI, in turn, may be influenced by different variables including specific illness-related factors as well as access to local psychiatric services. The purposes of the present study were to detect differences in terms of DUI among schizophrenics coming from different geographic areas and to evaluate differences in DUI across diagnostic sub-types. One hundred and twenty-five (125) schizophrenic patients of the Psychiatric Clinic of Milan (n = 51) and Moscow (n = 74) were enrolled. SCID-I was administered to all patients and information about DUI was obtained by consulting clinical charts and health system databases, and by means of clinical interviews with patients and their relatives. DUI was defined as the time between the onset of illness and the administration of the first antipsychotic drug. One-way analyses of variance (ANOVAs) were performed to find eventual differences in terms of DUI across diagnostic sub-types. Italian patients showed a longer DUI (M = 4.14 years, SD = 4.95) than Russians (M = 1.16 years, SD = 1.43) (F = 24.03, p < .001). DUI was found to be longer in paranoid schizophrenics (M = 3.47 years, SD = 4.19) compared to catatonic patients (M = 0.96 years, SD = 0.94) (F = 3.56, p = .016). The results of the present study suggest that the different schizophrenic sub-types may differ in terms of DUI, likely due to different clinical severity and social functioning. Studies with larger samples are needed to confirm the data of the present study.
PARENTAL ASSISTANCE, NEGATIVE LIFE EVENTS, AND ATTAINMENT DURING THE TRANSITION TO ADULTHOOD
Swartz, Teresa Toguchi; McLaughlin, Heather; Mortimer, Jeylan T.
2016-01-01
Responding to the longer and more variable transition to adulthood, parents are stepping in to help their young adult children. Little is known, however, about the extent to which parental support promotes success, and whether parental support has different effects for young adult sons and daughters. Using longitudinal data from the Youth Development Study, we find that parental scaffolding assistance for educational expenses predicts college graduation for both men and women. Negative life events experienced during the transition to adulthood are associated with lower earnings by the early 30s, although there is some variation by type of event. More frequent parental support during times of need does not predict long-term economic attainment for sons or daughters. PMID:28239198
Multiwavelength Opportunities for GeV and TeV Telescopes
NASA Technical Reports Server (NTRS)
Thompson, David J.
2010-01-01
With AGILE and Fermi now in orbit and TeV telescopes continuing to improve their performance, a variety of multiwavelength opportunities is increasingly available. One goal of such programs is to take advantage of the complementary capabilities of the two types of telescopes: the wide field surveys of the satellite detectors and the high sensitivity and resolution of the ground-based telescopes. Some aspects of these multiwavelength efforts will be carried out in near-real-time but must be anticipated with advance preparation. These include gamma-ray burst follow-ups and flare campaigns. Other projects such as long-term variability studies and gammaray source identification require deep observations and cooperative work with astrophysicists at longer wavelengths, along with the theoretical studies that tie the observations together.
PARENTAL ASSISTANCE, NEGATIVE LIFE EVENTS, AND ATTAINMENT DURING THE TRANSITION TO ADULTHOOD.
Swartz, Teresa Toguchi; McLaughlin, Heather; Mortimer, Jeylan T
2017-01-01
Responding to the longer and more variable transition to adulthood, parents are stepping in to help their young adult children. Little is known, however, about the extent to which parental support promotes success, and whether parental support has different effects for young adult sons and daughters. Using longitudinal data from the Youth Development Study, we find that parental scaffolding assistance for educational expenses predicts college graduation for both men and women. Negative life events experienced during the transition to adulthood are associated with lower earnings by the early 30s, although there is some variation by type of event. More frequent parental support during times of need does not predict long-term economic attainment for sons or daughters.
Atmospheric effects on earth rotation and polar motion
NASA Technical Reports Server (NTRS)
Salstein, David A.
1988-01-01
The variability in the earth's rotation rate not due to known solid body tides is dominated on time scales of about four years and less by variations in global atmospheric angular momentum (M) as derived from the zonal wind distribution. Among features seen in the length of day record produced by atmospheric forcing are the strong seasonal cycle, quasi-periodic fluctuations around 40-50 days, and an interannual signal forced by a strong Pacific warming event known as the El Nino. Momentum variations associated with these time scales arise in different latitudinal regions. Furthermore, winds in the stratosphere make a particularly important contribution to seasonal variability. Other related topics discussed here are: (1) comparisons of the M series from wind fields produced at different weather centers; (2) the torques that dynamically link the atmosphere and earth; and (3) longer-term nonatmospheric effects that can be seen upon removal of the atmospheric signal.an interestigapplication for climatological purposes is the use of the historical earth rotation series as a proxy for atmospheric wind variability prior to the era of upper-air data. Lastly, results pertaining to the role of atmospheric pressure systems in exciting rapid polar motion are presented.
Determinants of fast-food consumption. An application of the Theory of Planned Behaviour.
Dunn, Kirsten I; Mohr, Philip; Wilson, Carlene J; Wittert, Gary A
2011-10-01
This study applied and extended the Theory of Planned Behaviour (TPB; Ajzen, 1988) in an examination of the variables influencing fast-food consumption in an Australian sample. Four hundred and four participants responded to items measuring TPB constructs and retrospective and prospective measures of fast-food consumption. Additional independent variables included: Consideration of Future Consequences (Strathman, Gleicher, Boninger, & Edwards, 1994), Fear of Negative Evaluation (Leary, 1983), and Self-Identification as a Healthy Eater Scale (Armitage & Conner, 1999a). Structural Equation Modeling (SEM) was used to examine predictors of consumption. SEM indicated that the TPB successfully predicted fast-food consumption. Factor analyses assisted in the definition of constructs that underlay attitudes towards fast foods. These constructs were included in an 'extended' TPB model which then provided a richer source of information regarding the nature of the variables influencing fast-food consumption. Findings suggest that fast-food consumption is influenced by specific referent groups as well as a general demand for meals that are tasty, satisfying, and convenient. These factors reflect immediate needs and appear to override concerns about longer-term health risks associated with fast food. Results are discussed in the context of possible applications. Copyright © 2011 Elsevier Ltd. All rights reserved.
Short-term production and synoptic influences on atmospheric 7Be concentrations
NASA Astrophysics Data System (ADS)
Usoskin, Ilya G.; Field, Christy V.; Schmidt, Gavin A.; LeppäNen, Ari-Pekka; Aldahan, Ala; Kovaltsov, Gennady A.; Possnert, GöRan; Ungar, R. Kurt
2009-03-01
Variations of the cosmogenic radionuclide 7Be in the global atmosphere are driven by cooperation of processes of its production, air transports, and removal. We use a combination of the Goddard Institute for Space Studies ModelE and the OuluCRAC:7Be production model to simulate the variations in the 7Be concentration in the atmosphere for the period from 1 January to 28 February 2005. This period features significant synoptic variability at multiple monitoring stations around the globe and spans an extreme solar energetic particle (SEP) event that occurred on 20 January. Using nudging from observed horizontal winds, the model correctly reproduces the overall level of the measured 7Be concentration near ground and a great deal of the synoptic variability at timescales of 4 days and longer. This verifies the combined model of production and transport of the 7Be radionuclide in the atmosphere. The impact of an extreme SEP event of January 2005 is seen dramatically in polar stratospheric 7Be concentration but is small near the surface (about 2%) and indistinguishable given the amount of intrinsic variability and the uncertainties of the surface observations.
Convergence and accommodation development is pre-programmed in premature infants
Horwood, Anna M; Toor, Sonia S; Riddell, Patricia M
2015-01-01
Purpose This study investigated whether vergence and accommodation development in pre-term infants is pre-programmed or is driven by experience. Methods 32 healthy infants, born at mean 34 weeks gestation (range 31.2-36 weeks) were compared with 45 healthy full-term infants (mean 40.0 weeks) over a 6 month period, starting at 4-6 weeks post-natally. Simultaneous accommodation and convergence to a detailed target were measured using a Plusoptix PowerRefII infra-red photorefractor as a target moved between 0.33m and 2m. Stimulus/response gains and responses at 0.33m and 2m were compared by both corrected (gestational) age and chronological (post-natal) age. Results When compared by their corrected age, pre-term and full-term infants showed few significant differences in vergence and accommodation responses after 6-7 weeks of age. However, when compared by chronological age, pre-term infants’ responses were more variable, with significantly reduced vergence gains, reduced vergence response at 0.33m, reduced accommodation gain, and increased accommodation at 2m, compared to full-term infants between 8-13 weeks after birth. Conclusions When matched by corrected age, vergence and accommodation in pre-term infants show few differences from full-term infants’ responses. Maturation appears pre-programmed and is not advanced by visual experience. Longer periods of immature visual responses might leave pre-term infants more at risk of development of oculomotor deficits such as strabismus. PMID:26275135
Tropical cloud feedbacks and natural variability of climate
NASA Technical Reports Server (NTRS)
Miller, R. L.; Del Genio, A. D.
1994-01-01
Simulations of natural variability by two general circulation models (GCMs) are examined. One GCM is a sector model, allowing relatively rapid integration without simplification of the model physics, which would potentially exclude mechanisms of variability. Two mechanisms are found in which tropical surface temperature and sea surface temperature (SST) vary on interannual and longer timescales. Both are related to changes in cloud cover that modulate SST through the surface radiative flux. Over the equatorial ocean, SST and surface temperature vary on an interannual timescale, which is determined by the magnitude of the associated cloud cover anomalies. Over the subtropical ocean, variations in low cloud cover drive SST variations. In the sector model, the variability has no preferred timescale, but instead is characterized by a 'red' spectrum with increasing power at longer periods. In the terrestrial GCM, SST variability associated with low cloud anomalies has a decadal timescale and is the dominant form of global temperature variability. Both GCMs are coupled to a mixed layer ocean model, where dynamical heat transports are prescribed, thus filtering out El Nino-Southern Oscillation (ENSO) and thermohaline circulation variability. The occurrence of variability in the absence of dynamical ocean feedbacks suggests that climatic variability on long timescales can arise from atmospheric processes alone.
Chandarana, P; Jackson, T; Kohr, R; Iezzi, T
1997-01-01
The primary objective of this study was to examine the relationship between vocational disability, psychiatric illness, life stressors and sociodemographic factors. Information on a variety of variables was obtained from insurance files of 147 subjects who had submitted claims for monetary compensation on grounds of psychiatric symptoms. The majority of subjects received a diagnosis of mood disorder or anxiety disorder. Extended vocational disability was associated with longer duration of psychiatric illness, rating of poorer prognosis by the treating physician, and lower income and occupational levels. Individuals with recent onset of disability reported more stressors than those experiencing extended disability. Although longer duration of psychiatric illness was associated with vocational disability, other variables play an important role in accounting for extended vocational disability.
Miró, Òscar; Herrero-Puente, Pablo; Prieto, Belén; García-García, María; García-Hernández, Pablo; Martín-Sánchez, Francisco J; Jacob, Javier; Ríos, José; Romero, Rodolfo; Gil, Víctor; Gayat, Étienne; Llorens, Pere; Mebazaa, Alexandre
2018-05-01
To investigate how many patients with acute heart failure (AHF) hypersecrete relaxin-2 concentrations similar to those of pregnant women and determine their long-term outcome. In consecutive AHF patients relaxin-2 was quantified by ELISA sandwich method. Patients were divided into pregnancy-like group (PLG, relaxin-2 ≥ 500 pg/mL) and control group (CG, relaxin-2 < 500 pg/mL). The primary outcome was all-cause death during follow-up. Secondary endpoints were prolonged hospitalisation (>10 days), combined endpoint (death, rehospitalisation, ED revisit) 30 days after discharge, and 30-day, one-year and three-year death rates. We included 814 patients [81 (SD = 9) years; 53.0% women] followed during 1.9 (SD 2.8) years; 517 (63.5%) died. Twenty patients (2.5%) formed the PLG (median relaxin-2 = 1459 pg/mL; IQR = 1722) and 794 the CG (median = 26; IQR = 44). There was no interaction with variables included on adjustment (age, sex, ischaemic cardiomyopathy, NT-proBNP, glycaemia, and sodium). PLG patients did not have better short-term secondary endpoints, but did show a significantly lower three-year mortality [OR adjusted = 0.17 (0.05-0.5), p = 0.003]. The small proportion of AHF patients achieving relaxin-2 concentrations similar to those observed in pregnancy may survive longer.
Lager, Anton CJ; Modin, Bitte E; De Stavola, Bianca L; Vågerö, Denny H
2012-01-01
Background Intelligence at a single time-point has been linked to health outcomes. An individual's IQ increases with longer schooling, but the validity of such increase is unclear. In this study, we assess the hypothesis that individual change in the performance on IQ tests between ages 10 and 20 years is associated with mortality later in life. Methods The analyses are based on a cohort of Swedish boys born in 1928 (n = 610) for whom social background data were collected in 1937, IQ tests were carried out in 1938 and 1948 and own education and mortality were recorded up to 2006. Structural equation models were used to estimate the extent to which two latent intelligence scores, at ages 10 and 20 years, manifested by results on the IQ tests, are related to paternal and own education, and how all these variables are linked to all-cause mortality. Results Intelligence at the age of 20 years was associated with lower mortality in adulthood, after controlling for intelligence at the age of 10 years. The increases in intelligence partly mediated the link between longer schooling and lower mortality. Social background differences in adult intelligence (and consequently in mortality) were partly explained by the tendency for sons of more educated fathers to receive longer schooling, even when initial intelligence levels had been accounted for. Conclusions The results are consistent with a causal link from change in intelligence to mortality, and further, that schooling-induced changes in IQ scores are true and bring about lasting changes in intelligence. In addition, if both these interpretations are correct, social differences in access to longer schooling have consequences for social differences in both adult intelligence and adult health. PMID:22493324
The Dependence of Cloud-SST Feedback on Circulation Regime and Timescale
NASA Astrophysics Data System (ADS)
Middlemas, E.; Clement, A. C.; Medeiros, B.
2017-12-01
Studies suggest cloud radiative feedback amplifies internal variability of Pacific sea surface temperature (SST) on interannual-and-longer timescales, though only a few modeling studies have tested the quantitative importance of this feedback (Bellomo et al. 2014b, Brown et al. 2016, Radel et al. 2016 Burgman et al. 2017). We prescribe clouds from a previous control run in the radiation module in Community Atmospheric Model (CAM5-slab), a method called "cloud-locking". By comparing this run to a control run, in which cloud radiative forcing can feedback on the climate system, we isolate the effect of cloud radiative forcing on SST variability. Cloud-locking prevents clouds from radiatively interacting with atmospheric circulation, water vapor, and SST, while maintaining a similar mean state to the control. On all timescales, cloud radiative forcing's influence on SST variance is modulated by the circulation regime. Cloud radiative forcing amplifies SST variance in subsiding regimes and dampens SST variance in convecting regimes. In this particular model, a tug of war between latent heat flux and cloud radiative forcing determines the variance of SST, and the winner depends on the timescale. On decadal-and-longer timescales, cloud radiative forcing plays a relatively larger role than on interannual-and-shorter timescales, while latent heat flux plays a smaller role. On longer timescales, the absence of cloud radiative feedback changes SST variance in a zonally asymmetric pattern in the Pacific Ocean that resembles an IPO-like pattern. We also present an analysis of cloud feedback's role on Pacific SST variability among preindustrial control CMIP5 models to test the model robustness of our results. Our results suggest that circulation plays a crucial role in cloud-SST feedbacks across the globe and cloud radiative feedbacks cannot be ignored when studying SST variability on decadal-and-longer timescales.
Karstoft, Karen-Inge; Vedtofte, Mia S.; Nielsen, Anni B.S.; Osler, Merete; Mortensen, Erik L.; Christensen, Gunhild T.; Andersen, Søren B.
2017-01-01
Background Studies of the association between pre-deployment cognitive ability and post-deployment post-traumatic stress disorder (PTSD) have shown mixed results. Aims To study the influence of pre-deployment cognitive ability on PTSD symptoms 6–8 months post-deployment in a large population while controlling for pre-deployment education and deployment-related variables. Method Study linking prospective pre-deployment conscription board data with post-deployment self-reported data in 9695 Danish Army personnel deployed to different war zones in 1997–2013. The association between pre-deployment cognitive ability and post-deployment PTSD was investigated using repeated-measure logistic regression models. Two models with cognitive ability score as the main exposure variable were created (model 1 and model 2). Model 1 was only adjusted for pre-deployment variables, while model 2 was adjusted for both pre-deployment and deployment-related variables. Results When including only variables recorded pre-deployment (cognitive ability score and educational level) and gender (model 1), all variables predicted post-deployment PTSD. When deployment-related variables were added (model 2), this was no longer the case for cognitive ability score. However, when educational level was removed from the model adjusted for deployment-related variables, the association between cognitive ability and post-deployment PTSD became significant. Conclusions Pre-deployment lower cognitive ability did not predict post-deployment PTSD independently of educational level after adjustment for deployment-related variables. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:29163983
Effects of Exposures on Superalloys for Space Applications
NASA Technical Reports Server (NTRS)
Gabb, Tim; Garg, Anita; Gayda, John
2007-01-01
The industry is demanding longer term service at high temperatures for nickel-base superalloys in gas turbine engine as well as potential space applications. However, longer term service can severely tax alloy phase stability, to the potential detriment of mechanical properties. Cast Mar-M247LC and wrought Haynes 230 superalloys were exposed and creep tested for extended times at elevated temperature. Microstructure and phase evaluations were then undertaken for comparisons.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false May a Self-Governance Tribe negotiate a funding agreement for a term longer or shorter than one year? 137.78 Section 137.78 Public Health PUBLIC HEALTH... SERVICES TRIBAL SELF-GOVERNANCE Funding General § 137.78 May a Self-Governance Tribe negotiate a funding...
Assessment of vertical excursions and open-sea psychological performance at depths to 250 fsw.
Miller, J W; Bachrach, A J; Walsh, J M
1976-12-01
A series of 10 two-man descending vertical excursion dives was carried out in the open sea from an ocean-floor habitat off the coast of Puerto Rico by four aquanauts saturated on a normoxic-nitrogen breathing mixture at a depth of 106 fsw. The purpose of these dives was two-fold: to validate laboratory findings with respect to decompression schedules and to determine whether such excursions would produce evidence of adaptation to nitrogen narcosis. For the latter, tests designed to measure time estimation, short-term memory, and auditory vigilance were used. The validation of experimental excursion tables was carried out without incidence of decompression sickness. Although no signs of nitrogen narcosis were noted during testing, all subjects made significantly longer time estimates in the habitat and during the excursions than on the surface. Variability and incomplete data prevented a statistical analysis of the short-term memory results, and the auditory vigilance proved unusable in the water.
Computation of rapidly varied unsteady, free-surface flow
Basco, D.R.
1987-01-01
Many unsteady flows in hydraulics occur with relatively large gradients in free surface profiles. The assumption of hydrostatic pressure distribution with depth is no longer valid. These are rapidly-varied unsteady flows (RVF) of classical hydraulics and also encompass short wave propagation of coastal hydraulics. The purpose of this report is to present an introductory review of the Boussinnesq-type differential equations that describe these flows and to discuss methods for their numerical integration. On variable slopes and for large scale (finite-amplitude) disturbances, three independent derivational methods all gave differences in the motion equation for higher order terms. The importance of these higher-order terms for riverine applications must be determined by numerical experiments. Care must be taken in selection of the appropriate finite-difference scheme to minimize truncation error effects and the possibility of diverging (double mode) numerical solutions. It is recommended that practical hydraulics cases be established and tested numerically to demonstrate the order of differences in solution with those obtained from the long wave equations of St. Venant. (USGS)
Daily Spouse Responsiveness Predicts Longer-Term Trajectories of Physical Function
Wilson, Stephanie J.; Martire, Lynn M.; Sliwinski, Martin J.
2017-01-01
Everyday interpersonal experiences may underlie the well-established link between close relationships and physical health, but multitemporal designs necessary for strong conclusions about temporal sequence are rare. The current study of 145 knee osteoarthritis patients and their spouses focused on a novel pattern in everyday interactions, daily spouse responsiveness—the degree to which spouse responses are calibrated to changes in patients’ everyday verbal pain expression. Using couple-level slopes, multilevel latent-variable growth models tested associations between three types of daily spouse responsiveness (empathic, solicitous, and punishing), as measured during a 3-week experience-sampling study, and change in patient physical function across 18 months. As predicted, patients whose spouses were more empathically responsive to their pain expression showed better physical function over time compared to those whose spouses were less empathically responsive. This study points to daily responsiveness, a theoretically rooted operationalization of spouse sensitivity, as important for long-term changes in objective physical function. PMID:28459650
The effect of a high protein diet on leucine and alanine turnover in acid maltase deficiency.
Umpleby, A M; Trend, P S; Chubb, D; Conaglen, J V; Williams, C D; Hesp, R; Scobie, I N; Wiles, C M; Spencer, G; Sönksen, P H
1989-01-01
Leucine and alanine production rate was measured in 5 patients with acid maltase deficiency in the postabsorptive state, following 6 months on a normal diet with placebo and 6 months on an isocaloric high protein diet (16-22% protein). Whole body leucine production rate, a measure of protein degradation, expressed in terms of lean body mass was significantly greater than in five control subjects. Following the high protein diet, leucine production rate was decreased in four of the five patients but this was not statistically significant. Alanine production rate expressed in terms of lean body mass was significantly greater than in control subjects. After the high protein diet, alanine production rate and concentration were significantly decreased (p less than 0.05). There were no significant improvements in any of the clinically relevant variables measured in these patients. It is possible that a larger increase in protein intake over a longer time period may have a clinical effect. PMID:2507747
Recombination and phenotype evolution dynamics of Helicobacter pylori in colonized hosts.
Shafiee, Ahmad; Amini, Massoud; Emamirad, Hassan; Abadi, Amin Talebi Bezmin
2016-07-01
The ample genetic diversity and variability of Helicobater pylori, and therefore its phenotypic evolution, relate not only to frequent mutation and selection but also to intra-specific recombination. Webb and Blaser applied a mathematical model to distinguish the role of selection and mutation for Lewis antigen phenotype evolution during long-term gastric colonization in infected animal hosts (mice and gerbils). To investigate the role of recombination in Lewis antigen phenotype evolution, we have developed a prior population dynamic by adding recombination term to the model. We simulate and interpret the new model simulation's results with a comparative analysis of biological aspects. The main conclusions are as follows: (i) the models and consequently the hosts with higher recombination rate require a longer time for stabilization; and (ii) recombination and mutation have opposite effects on the size of H. pylori populations with phenotypes in the range of the most-fit ones (i.e. those that have a selective advantage) due to natural selection, although both can increase phenotypic diversity.
Global Warming: Discussion for EOS Science Writers Workshop
NASA Technical Reports Server (NTRS)
Hansen, James E
1999-01-01
The existence of global warming this century is no longer an issue of scientific debate. But there are many important questions about the nature and causes of long-term climate change, th roles of nature and human-made climate forcings and unforced (chaotic) climate variability, the practical impacts of climate change, and what, if anything, should be done to reduce global warming, Global warming is not a uniform increase of temperature, but rather involves at complex geographically varying climate change. Understanding of global warming will require improved observations of climate change itself and the forcing factors that can lead to climate change. The NASA Terra mission and other NASA Earth Science missions will provide key measurement of climate change and climate forcings. The strategy to develop an understanding of the causes and predictability of long-term climate change must be based on combination of observations with models and analysis. The upcoming NASA missions will make important contributions to the required observations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burykina, L.N.; Zakutinskii, D.I.; Kraevskii, N.A.
Data on the long-term effects produced by radioactive substances administered to dogs, rabbits, and rats in various ways, both in single and repeated doses, are reported. The animals were studied for three years or longer. Three successive phases were found in the chronic irradiation disease caused by the introduction of radioactive substances: the stimulation phase characterized by an instability and variability of clinical symptoms (blood picture, cardio- vascular system, and the physiological system); the phase of apparent compensation when all the symptoms are restored to normal, although changes are recorded in the reactivity of various systems of the organism whenmore » functional loads are applied; and the phase when symptoms, typical of the chronic stage of radiation disease, develop. The blastomogenous effects of radioactive substances was given special attention. Pre-tumor changes in the bone was also studied. (J.S.R.)« less
On configurational forces for gradient-enhanced inelasticity
NASA Astrophysics Data System (ADS)
Floros, Dimosthenis; Larsson, Fredrik; Runesson, Kenneth
2018-04-01
In this paper we discuss how configurational forces can be computed in an efficient and robust manner when a constitutive continuum model of gradient-enhanced viscoplasticity is adopted, whereby a suitably tailored mixed variational formulation in terms of displacements and micro-stresses is used. It is demonstrated that such a formulation produces sufficient regularity to overcome numerical difficulties that are notorious for a local constitutive model. In particular, no nodal smoothing of the internal variable fields is required. Moreover, the pathological mesh sensitivity that has been reported in the literature for a standard local model is no longer present. Numerical results in terms of configurational forces are shown for (1) a smooth interface and (2) a discrete edge crack. The corresponding configurational forces are computed for different values of the intrinsic length parameter. It is concluded that the convergence of the computed configurational forces with mesh refinement depends strongly on this parameter value. Moreover, the convergence behavior for the limit situation of rate-independent plasticity is unaffected by the relaxation time parameter.
Application of Grey Model GM(1, 1) to Ultra Short-Term Predictions of Universal Time
NASA Astrophysics Data System (ADS)
Lei, Yu; Guo, Min; Zhao, Danning; Cai, Hongbing; Hu, Dandan
2016-03-01
A mathematical model known as one-order one-variable grey differential equation model GM(1, 1) has been herein employed successfully for the ultra short-term (<10days) predictions of universal time (UT1-UTC). The results of predictions are analyzed and compared with those obtained by other methods. It is shown that the accuracy of the predictions is comparable with that obtained by other prediction methods. The proposed method is able to yield an exact prediction even though only a few observations are provided. Hence it is very valuable in the case of a small size dataset since traditional methods, e.g., least-squares (LS) extrapolation, require longer data span to make a good forecast. In addition, these results can be obtained without making any assumption about an original dataset, and thus is of high reliability. Another advantage is that the developed method is easy to use. All these reveal a great potential of the GM(1, 1) model for UT1-UTC predictions.
NASA Technical Reports Server (NTRS)
Derks, Peter L.; Gillikin, Lynn S.
1993-01-01
The research reported here describes the process of induction of various mental states. Our goals were to measure and to manipulate both the behavioral and the neurological correlates of particular mental states that have previously been demonstrated to be either beneficial or deleterious to in-flight performance situations. The experimental paradigm involved developing a context of which the participants were aware, followed by the introduction of an incongruity into that context. The empirical questions involved how the incongruity was resolved and the consequent effects on mental state. The dependent variables were measures of both the short-term ERP changes and the longer-term brain mapping indications of predominant mental states. The mission of NASA Flight Management Division and Human/Automation Integration Branch centers on the understanding and improvement of interaction between a complex system and a human operator. Specifically, the goal is improved efficiency through better operative procedures and control strategies. More efficient performance in demanding flight environments depends on improved situational awareness and replanning for fault management.
Interannual to Decadal SST Variability in the Tropical Indian Ocean
NASA Astrophysics Data System (ADS)
Wang, G.; Newman, M.; Han, W.
2017-12-01
The Indian Ocean has received increasing attention in recent years for its large impacts on regional and global climate. However, due mainly to the close interdependence of the climate variation within the Tropical Pacific and the Indian Ocean, the internal sea surface temperature (SST) variability within the Indian Ocean has not been studied extensively on longer time scales. In this presentation we will show analysis of the interannual to decadal SST variability in the Tropical Indian Ocean in observations and Linear Inverse Model (LIM) results. We also compare the decoupled Indian Ocean SST variability from the Pacific against fully coupled one based on LIM integrations, to test the factors influence the features of the leading SST modes in the Indian Ocean. The result shows the Indian Ocean Basin (IOB) mode, which is strongly related to global averaged SST variability, passively responses to the Pacific variation. Without tropical Indo-Pacific coupling interaction, the intensity of IOB significantly decreases by 80%. The Indian Ocean Dipole (IOD) mode demonstrates its independence from the Pacific SST variability since the IOD does not change its long-term characteristics at all without inter-basin interactions. The overall SSTA variance decreases significantly in the Tropical Indian Ocean in the coupling restricted LIM runs, especially when the one-way impact from the Pacific to the Indian Ocean is turned off, suggesting that most of the variability in the Indian Ocean comes from the Pacific influence. On the other hand, the Indian Ocean could also transport anomalies to the Pacific, making the interaction a complete two-way process.
Clarke, David
2017-01-01
Objective To review and synthesise qualitative literature relating to the longer-term needs of community dwelling stroke survivors with communication difficulties including aphasia, dysarthria and apraxia of speech. Design Systematic review and thematic synthesis. Method We included studies employing qualitative methodology which focused on the perceived or expressed needs, views or experiences of stroke survivors with communication difficulties in relation to the day-to-day management of their condition following hospital discharge. We searched MEDLINE, EMBASE, PsycINFO, CINAHL, The Cochrane Library, International Bibliography of the Social Sciences and AMED and undertook grey literature searches. Studies were assessed for methodological quality by two researchers independently and the findings were combined using thematic synthesis. Results Thirty-two studies were included in the thematic synthesis. The synthesis reveals the ongoing difficulties stroke survivors can experience in coming to terms with the loss of communication and in adapting to life with a communication difficulty. While some were able to adjust, others struggled to maintain their social networks and to participate in activities which were meaningful to them. The challenges experienced by stroke survivors with communication difficulties persisted for many years poststroke. Four themes relating to longer-term need were developed: managing communication outside of the home, creating a meaningful role, creating or maintaining a support network and taking control and actively moving forward with life. Conclusions Understanding the experiences of stroke survivors with communication difficulties is vital for ensuring that longer-term care is designed according to their needs. Wider psychosocial factors must be considered in the rehabilitation of people with poststroke communication difficulties. Self-management interventions may be appropriate to help this subgroup of stroke survivors manage their condition in the longer-term; however, such approaches must be designed to help survivors to manage the unique psychosocial consequences of poststroke communication difficulties. PMID:28988185
NASA Astrophysics Data System (ADS)
Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.
2009-09-01
We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43+34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br, M BH, and L bol, followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.
Young Stellar Object VARiability (YSOVAR): Long Timescale Variations in the Mid-infrared
NASA Astrophysics Data System (ADS)
Rebull, L. M.; Cody, A. M.; Covey, K. R.; Günther, H. M.; Hillenbrand, L. A.; Plavchan, P.; Poppenhaeger, K.; Stauffer, J. R.; Wolk, S. J.; Gutermuth, R.; Morales-Calderón, M.; Song, I.; Barrado, D.; Bayo, A.; James, D.; Hora, J. L.; Vrba, F. J.; Alves de Oliveira, C.; Bouvier, J.; Carey, S. J.; Carpenter, J. M.; Favata, F.; Flaherty, K.; Forbrich, J.; Hernandez, J.; McCaughrean, M. J.; Megeath, S. T.; Micela, G.; Smith, H. A.; Terebey, S.; Turner, N.; Allen, L.; Ardila, D.; Bouy, H.; Guieu, S.
2014-11-01
The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (3.6 and 4.5 μm) time series photometry of the Orion Nebula Cluster plus smaller footprints in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. We present the data collection and reduction for the Spitzer and ancillary data, and define the "standard sample" on which we calculate statistics, consisting of fast cadence data, with epochs roughly twice per day for ~40 days. We also define a "standard sample of members" consisting of all the IR-selected members and X-ray-selected members. We characterize the standard sample in terms of other properties, such as spectral energy distribution shape. We use three mechanisms to identify variables in the fast cadence data—the Stetson index, a χ2 fit to a flat light curve, and significant periodicity. We also identified variables on the longest timescales possible of six to seven years by comparing measurements taken early in the Spitzer mission with the mean from our YSOVAR campaign. The fraction of members in each cluster that are variable on these longest timescales is a function of the ratio of Class I/total members in each cluster, such that clusters with a higher fraction of Class I objects also have a higher fraction of long-term variables. For objects with a YSOVAR-determined period and a [3.6]-[8] color, we find that a star with a longer period is more likely than those with shorter periods to have an IR excess. We do not find any evidence for variability that causes [3.6]-[4.5] excesses to appear or vanish within our data set; out of members and field objects combined, at most 0.02% may have transient IR excesses.
NASA Technical Reports Server (NTRS)
Corbet, Robin H. D.; Coley, Joel B.; Krimm, Hans A.
2017-01-01
We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope (SWIFT-BAT). IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 seconds. For AX J1700.2-4220, 54 second-pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090,which was previously proposed to be a Be star system with an orbital period of approximately 30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although theymight be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be starmass donors.
NASA Astrophysics Data System (ADS)
Corbet, Robin H. D.; Coley, Joel B.; Krimm, Hans A.
2017-09-01
We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ˜30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.
NASA Astrophysics Data System (ADS)
Corbet, Robin; Coley, Joel Barry; Krimm, Hans A.
2017-08-01
We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. (2014). AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ˜30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.
Precision Photometry of Long Period Variable Stars: Flares and Bumps in the Night (Poster abstract)
NASA Astrophysics Data System (ADS)
Mais, D.
2015-06-01
(Abstract only) Mira variable stars are a broad class of stars, which encompass spectroscopic classes of type M, S, and C. These stars are closely related in terms of their long term variability, position on the Hertzsprung-Russell diagram their intermediate mass (from ~0.8 to ~8 solar mass) and the fact that class M evolves into the S and C type stars as certain stages of shell burning around the core proceeds. Recently, evidence has accumulated to suggest that Mira variables may go through flare up stages which result in brightening on the order of several tenths of a magnitude or more and may last hours to days in length. Very little is known about these events, indeed it is not clear that these events are real. In order to address the reality of these events, we established an automated acquisition/analysis of a group of 108 Mira variables in order to obtain the densest coverage of the periods to better constrain the potential flare-ups. Telescope control scripts were put in place along with real time analysis. This allowed for unattended acquisition of data on every clear night, all night long, in the V, R, and I photometric bands. In addition, during the course of the night multiple determinations are often obtained for a given star. The light curves of many of the program stars show a Cepheid-like bump phenomenon, however these appear on the ascending part of the light curve. In general, these bumps appear in longer period Mira's (>350 days). Bumps are not obvious or easily seen in VISUAL data records, although slope changes during rising phase are seen in some cases. So far, greater than 100,000 magnitude determinations have been obtained, many closely spaced in time. This should help to further constrain the potential occurrences of flare-up events.
Barton, Hugh A; Chiu, Weihsueh A; Setzer, R Woodrow; Andersen, Melvin E; Bailer, A John; Bois, Frédéric Y; Dewoskin, Robert S; Hays, Sean; Johanson, Gunnar; Jones, Nancy; Loizou, George; Macphail, Robert C; Portier, Christopher J; Spendiff, Martin; Tan, Yu-Mei
2007-10-01
Physiologically based pharmacokinetic (PBPK) models are used in mode-of-action based risk and safety assessments to estimate internal dosimetry in animals and humans. When used in risk assessment, these models can provide a basis for extrapolating between species, doses, and exposure routes or for justifying nondefault values for uncertainty factors. Characterization of uncertainty and variability is increasingly recognized as important for risk assessment; this represents a continuing challenge for both PBPK modelers and users. Current practices show significant progress in specifying deterministic biological models and nondeterministic (often statistical) models, estimating parameters using diverse data sets from multiple sources, using them to make predictions, and characterizing uncertainty and variability of model parameters and predictions. The International Workshop on Uncertainty and Variability in PBPK Models, held 31 Oct-2 Nov 2006, identified the state-of-the-science, needed changes in practice and implementation, and research priorities. For the short term, these include (1) multidisciplinary teams to integrate deterministic and nondeterministic/statistical models; (2) broader use of sensitivity analyses, including for structural and global (rather than local) parameter changes; and (3) enhanced transparency and reproducibility through improved documentation of model structure(s), parameter values, sensitivity and other analyses, and supporting, discrepant, or excluded data. Longer-term needs include (1) theoretical and practical methodological improvements for nondeterministic/statistical modeling; (2) better methods for evaluating alternative model structures; (3) peer-reviewed databases of parameters and covariates, and their distributions; (4) expanded coverage of PBPK models across chemicals with different properties; and (5) training and reference materials, such as cases studies, bibliographies/glossaries, model repositories, and enhanced software. The multidisciplinary dialogue initiated by this Workshop will foster the collaboration, research, data collection, and training necessary to make characterizing uncertainty and variability a standard practice in PBPK modeling and risk assessment.
Nixon, Reginald D V; Sterk, Jisca; Pearce, Amanda; Weber, Nathan
2017-07-01
The 1-year outcome and moderators of adjustment for children and youth receiving treatment for posttraumatic stress disorder (PTSD) following single-incident trauma was examined. Children and youth who had experienced single-incident trauma (N = 33; 7-17 years old) were randomly assigned to receive 9 weeks of either trauma-focused cognitive behavior therapy (CBT) or trauma-focused cognitive therapy (without exposure; CT) that was administered to them and their parents individually. Intent-to-treat analyses demonstrated that both groups maintained posttreatment gains in PTSD, depression and general anxiety symptoms reductions at 1-year follow-up, with no children meeting criteria for PTSD. A large proportion of children showed good end-state functioning at follow-up (CBT: 65%; CT: 71%). Contrary to 6-month outcomes, maternal adjustment no longer moderated children's outcome, nor did any other tested variables. The findings confirm the positive longer-term outcomes of using trauma-focused cognitive-behavioral methods for PTSD secondary to single-incident trauma and that these outcomes are not dependent on the use of exposure. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Tidière, Morgane; Gaillard, Jean-Michel; Berger, Vérane; Müller, Dennis W H; Bingaman Lackey, Laurie; Gimenez, Olivier; Clauss, Marcus; Lemaître, Jean-François
2016-11-07
While it is commonly believed that animals live longer in zoos than in the wild, this assumption has rarely been tested. We compared four survival metrics (longevity, baseline mortality, onset of senescence and rate of senescence) between both sexes of free-ranging and zoo populations of more than 50 mammal species. We found that mammals from zoo populations generally lived longer than their wild counterparts (84% of species). The effect was most notable in species with a faster pace of life (i.e. a short life span, high reproductive rate and high mortality in the wild) because zoos evidently offer protection against a number of relevant conditions like predation, intraspecific competition and diseases. Species with a slower pace of life (i.e. a long life span, low reproduction rate and low mortality in the wild) benefit less from captivity in terms of longevity; in such species, there is probably less potential for a reduction in mortality. These findings provide a first general explanation about the different magnitude of zoo environment benefits among mammalian species, and thereby highlight the effort that is needed to improve captive conditions for slow-living species that are particularly susceptible to extinction in the wild.
Oral ketamine for the treatment of pain and treatment-resistant depression†.
Schoevers, Robert A; Chaves, Tharcila V; Balukova, Sonya M; Rot, Marije Aan Het; Kortekaas, Rudie
2016-02-01
Recent studies with intravenous (i.v.) application of ketamine show remarkable but short-term success in patients with MDD. Studies in patients with chronic pain have used different ketamine applications for longer time periods. This experience may be relevant for psychiatric indications. To review the literature about the dosing regimen, duration, effects and side-effects of oral, intravenous, intranasal and subcutaneous routes of administration of ketamine for treatment-resistant depression and pain. Searches in PubMed with the terms 'oral ketamine', 'depression', 'chronic pain', 'neuropathic pain', 'intravenous ketamine', 'intranasal ketamine' and 'subcutaneous ketamine' yielded 88 articles. We reviewed all papers for information about dosing regimen, number of individuals who received ketamine, number of ketamine days per study, results and side-effects, as well as study quality. Overall, the methodological strength of studies investigating the antidepressant effects of ketamine was considered low, regardless of the route of administration. The doses for depression were in the lower range compared with studies that investigated analgesic use. Studies on pain suggested that oral ketamine may be acceptable for treatment-resistant depression in terms of tolerability and side-effects. Oral ketamine, given for longer time periods in the described doses, appears to be well tolerated, but few studies have systematically examined the longer-term negative consequences. The short- and longer-term depression outcomes as well as side-effects need to be studied with rigorous randomised controlled trials. © The Royal College of Psychiatrists 2016.
Behavioral and Physiological Response of Baleen Whales to Ships and Ship Noise
2014-09-30
student Angela Szesciorka) on tag designs to provide longer term deployments of archival tags especially for work with humpback whales off northern...California. 2. Conduct test deployments of dart-attached archival tags in 2014 on humpback whales in Monterey Bay and the Gulf of the Farallones on... humpback whales to tests different dart attachment configurations and develop a new longer term dart-attached archival tag system. 3. Successfully
Ross sea ice motion, area flux, and deformation
NASA Technical Reports Server (NTRS)
kwok, Ron
2005-01-01
The sea ice motion, area export, and deformation of the Ross Sea ice cover are examined with satellite passive microwave and RADARSAT observations. The record of high-resolution synthetic aperture radar (SAR) data, from 1998 and 2000, allows the estimation of the variability of ice deformation at the small scale (10 km) and to assess the quality of the longer record of passive microwave ice motion. Daily and subdaily deformation fields and RADARSAT imagery highlight the variability of motion and deformation in the Ross Sea. With the passive microwave ice motion, the area export at a flux gate positioned between Cape Adare and Land Bay is estimated. Between 1992 and 2003, a positive trend can be seen in the winter (March-November) ice area flux that has a mean of 990 x 103 km2 and ranges from a low of 600 x 103 km2 in 1992 to a peak of 1600 x 103 km2 in 2001. In the mean, the southern Ross Sea produces almost twice its own area of sea ice during the winter. Cross-gate sea level pressure (SLP) gradients explain 60% of the variance in the ice area flux. A positive trend in this gradient, from reanalysis products, suggests a 'spinup' of the Ross Sea Gyre over the past 12 yr. In both the NCEP-NCAR and ERA-40 surface pressure fields, longer-term trends in this gradient and mean SLP between 1979 and 2002 are explored along with positive anomalies in the monthly cross-gate SLP gradient associated with the positive phase of the Southern Hemisphere annular mode and the extrapolar Southern Oscillation.
A study on the changes in attractive force of magnetic attachments for overdenture
Lee, Jong-Hyuk; Choi, Yu-Sung
2016-01-01
PURPOSE Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients. MATERIALS AND METHODS Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet. RESULTS Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (P<.05, r=.361). Reduction ratio of attractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (P<.05). Furthermore, 16.39% of total magnetic attachments showed detachment of keeper or assembly. CONCLUSION Attractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed. PMID:26949482
Surface Salinity Variability in the North Atlantic During Recent Decades
NASA Technical Reports Server (NTRS)
Haekkinen, Sirpa
2001-01-01
The sea surface salinity (SSS) variability in the North Atlantic is investigated using numerical model simulations for the last 50 years based on atmospheric forcing variability from Comprehensive Atmosphere Ocean Data Set (COADS) and National Center for Environmental Prediction / National Center for Atmospheric Research (NCEP/NCAR) Reanalysis. The largest interannual and longer term variability occurs in two regions: the Labrador Sea and the North Equatorial Countercurrent (NECC) region. In both regions the seasonality of the surface salinity variability is prominent with the maximum standard deviation occurring in the summer/fall period. In the Labrador Sea the summer SSS anomalies far exceed those of wintertime in amplitude. The interannual SSS variability in the subpolar gyre can be attributed to two factors: excess ice melt and heat flux (i.e. deep mixing) variations. On the other hand, heat flux variability can also lead to meridional overturning changes on decadal time scales such that weak overturning is manifested in fresh surface conditions in the subpolar gyre. The overturning changes also influence the NECC region SSS variability. Moreover, the subpolar freshening events are expected to occur during the negative phase of North Atlantic Oscillation which is associated with a weak wintertime surface heat loss in the subpolar gyre. No excess sea ice melt or precipitation is necessary for the formation of the fresh anomalies, because with the lack of wide-spread deep mixing, the fresh water that would be expected based on climatology, would accumulate at the surface. Thus, the fresh water 'conveyor' in the Atlantic operates via the overturning circulation such that deep mixing inserts fresh water while removing heat from the water column.
NASA Astrophysics Data System (ADS)
Helton, A. M.; Poole, G. C.; Payn, R. A.; Izurieta, C.; Wright, M.; Bernhardt, E. S.; Stanford, J. A.
2014-12-01
The unsteadiness of stream water age is now well established, but the controls on the age dynamics, and the adequate representation and prediction of those dynamics, are not. A basic distinction can be made between internal variability that arises from changes in the proportions of flow moving through the diverse flow pathways of a hydrologic system, and external variability that arises from the stochasticity of inputs and outputs (such as precipitation and streamflow). In this talk I will show how these two types of age variability can be formally defined and distinguished within the framework of rank StorAge Selection (rSAS) functions. Internal variability implies variations in time in the rSAS function, while external variability does not. This leads naturally to the definition of several modes of internal variability, reflecting generic ways that system flowpaths may be rearranged. This rearrangement may be induced by fluctuations in the system state (such as catchment wetness), or by longer-term changes in catchment structure (such as land use change). One type of change, the 'inverse storage effect' is characterized by an increase in the release of young water from the system in response to an increase in overall system storage. This effect can be seen in many hydrologic settings, and has important implications for the effect of altered hydroclimatic conditions on solute transport through a landscape. External variability, such as increased precipitation, can induce a decrease in mean transit time (and vice versa), but this effect is greatly enhanced if accompanied by an internal shift in flow pathways that increases the relative importance of younger water. These effects will be illustrated using data from field and experimental studies.
NASA Astrophysics Data System (ADS)
Harman, C. J.
2015-12-01
The unsteadiness of stream water age is now well established, but the controls on the age dynamics, and the adequate representation and prediction of those dynamics, are not. A basic distinction can be made between internal variability that arises from changes in the proportions of flow moving through the diverse flow pathways of a hydrologic system, and external variability that arises from the stochasticity of inputs and outputs (such as precipitation and streamflow). In this talk I will show how these two types of age variability can be formally defined and distinguished within the framework of rank StorAge Selection (rSAS) functions. Internal variability implies variations in time in the rSAS function, while external variability does not. This leads naturally to the definition of several modes of internal variability, reflecting generic ways that system flowpaths may be rearranged. This rearrangement may be induced by fluctuations in the system state (such as catchment wetness), or by longer-term changes in catchment structure (such as land use change). One type of change, the 'inverse storage effect' is characterized by an increase in the release of young water from the system in response to an increase in overall system storage. This effect can be seen in many hydrologic settings, and has important implications for the effect of altered hydroclimatic conditions on solute transport through a landscape. External variability, such as increased precipitation, can induce a decrease in mean transit time (and vice versa), but this effect is greatly enhanced if accompanied by an internal shift in flow pathways that increases the relative importance of younger water. These effects will be illustrated using data from field and experimental studies.
Egli, Simone C; Beck, Irene R; Berres, Manfred; Foldi, Nancy S; Monsch, Andreas U; Sollberger, Marc
2014-10-01
It is unclear whether the predictive strength of established cognitive variables for progression to Alzheimer's disease (AD) dementia from mild cognitive impairment (MCI) varies depending on time to conversion. We investigated which cognitive variables were best predictors, and which of these variables remained predictive for patients with longer times to conversion. Seventy-five participants with MCI were assessed on measures of learning, memory, language, and executive function. Relative predictive strengths of these measures were analyzed using Cox regression models. Measures of word-list position-namely, serial position scores-together with Short Delay Free Recall of word-list learning best predicted conversion to AD dementia. However, only serial position scores predicted those participants with longer time to conversion. Results emphasize that the predictive strength of cognitive variables varies depending on time to conversion to dementia. Moreover, finer measures of learning captured by serial position scores were the most sensitive predictors of AD dementia. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
Attenberger, Corinna; Amsler, Felix; Gross, Thomas
2012-09-01
No sufficiently validated disease-specific instrument is available to assess patient outcome after polytrauma. The aim of this investigation was to test the recently published Trauma Outcome Profile (TOP) in the longer-term outcome of multiply injured patients. Single centre validation study on the TOP in comparison with objective and subjective measures of patient, injury or treatment characteristics and longer-term outcome (e.g. medical outcomes study Short Form-36, SF-36; Nottingham Health Profile, NHP; working capacity), at least 2 years following trauma in 117 survivors of polytrauma (injury severity score, ISS>16), using comparative analysis and correlation testing of prospectively collected data. Patients' mean weighted self-rating with regard to the 10 single TOP dimensions of Health Related Quality of Life (HRQoL, 0-100) ranged from lowest values for mental functioning (52.6+33.5) to highest values for daily activities (79.0+27.5). The rate of persons who indicated an abnormal level of function or pain increased significantly from pre-injury status (2% and 5%, resp.) to 46% for both values at longer-term follow-up (p<0.001). Observed associations between single dimensions or TOP component summary scores with the corresponding values from general HRQol instruments, such as the SF-36, resulted in R (Pearson) up to 0.85. Survivors of polytrauma who presented with a reduced working capacity (RWC) at longer-term follow-up in all TOP dimensions included a significantly higher rate of patients conspicuous for a relevantly reduced outcome compared with those with a non reduced working capacity (NRWC) (posttraumatic stress disease, PTSD: p<0.05; all other dimensions: p<0.001). Patients with a RWC were characterised by an almost fivefold probability of reduced outcome with regard to the TOP dimensions 'social interaction' or 'satisfaction' (odds ratio, OR 12.4 (95% CI 5.1-30.1) and 12.5 (4.0-39.0), resp.). This first clinical and methodological evaluation in a well defined cohort of polytrauma patients found the TOP to be a reliable and well discriminating score covering both relevant general and trauma-specific aspects of longer-term outcome. Despite these promising primary results, until further validation, the TOP should be used together with already accepted HRQoL measures to allow adequate international comparison of data in the future. Copyright © 2011 Elsevier Ltd. All rights reserved.
2015-01-01
The impact of living abroad is a topic that has intrigued researchers for almost a century, if not longer. While many acculturation phenomena have been studied over this time, the development of new research methods and statistical software in recent years means that these can be revisited and examined in a more rigorous manner. In the present study we were able to follow approximately 2,500 intercultural exchange students situated in over 50 different countries worldwide, over time both before and during their travel using online surveys. Advanced statistical analyses were employed to examine the course of sojourners stress and adjustment over time, its antecedents and consequences. By comparing a sojourner sample with a control group of nonsojourning peers we were able to highlight the uniqueness of the sojourn experience in terms of stress variability over time. Using Latent Class Growth Analysis to examine the nature of this variability revealed 5 distinct patterns of change in stress experienced by sojourners over the course of their exchange: a reverse J-curve, inverse U-curve, mild stress, minor relief, and resilience pattern. Antecedent explanatory variables for stress variability were examined using both variable-centered and person-centered analyses and evidence for the role of personality, empathy, cultural adaptation, and coping strategies was found in each case. Lastly, we examined the relationship between stress abroad with behavioral indicators of (mal)adjustment: number of family changes and early termination of the exchange program. PMID:26191963
Classification of collected trot, passage and piaffe based on temporal variables.
Clayton, H M
1997-05-01
The objective was to determine whether collected trot, passage and piaffe could be distinguished as separate gaits on the basis of temporal variables. Sagittal plane, 60 Hz videotapes of 10 finalists in the dressage competitions at the 1992 Olympic Games were analysed to measure the temporal variables in absolute terms and as percentages of stride duration. Classification was based on analysis of variance, a graphical method and discriminant analysis. Stride duration was sufficient to distinguish collected trot from passage and piaffe in all horses. The analysis of variance showed that the mean values of most variables differed significantly between passage and piaffe. When hindlimb stance percentage was plotted against diagonal advanced placement percentage, some overlap was found between all 3 movements indicating that individual horses could not be classified reliably in this manner. Using hindlimb stance percentage and diagonal advanced placement percentage as input in a discriminant analysis, 80% of the cases were classified correctly, but at least one horse was misclassified in each movement. When the absolute, rather than percentage, values of the 2 variables were used as input in the discriminant analysis, 90% of the cases were correctly classified and the only misclassifications were between passage and piaffe. However, the 2 horses in which piaffe was misclassified as passage were the gold and silver medallists. In general, higher placed horses tended toward longer diagonal advanced placements, especially in collected trot and passage, and shorter hindlimb stance percentages in passage and piaffe.
Centennial-scale Holocene climate variations amplified by Antarctic Ice Sheet discharge
NASA Astrophysics Data System (ADS)
Bakker, Pepijn; Clark, Peter U.; Golledge, Nicholas R.; Schmittner, Andreas; Weber, Michael E.
2017-01-01
Proxy-based indicators of past climate change show that current global climate models systematically underestimate Holocene-epoch climate variability on centennial to multi-millennial timescales, with the mismatch increasing for longer periods. Proposed explanations for the discrepancy include ocean-atmosphere coupling that is too weak in models, insufficient energy cascades from smaller to larger spatial and temporal scales, or that global climate models do not consider slow climate feedbacks related to the carbon cycle or interactions between ice sheets and climate. Such interactions, however, are known to have strongly affected centennial- to orbital-scale climate variability during past glaciations, and are likely to be important in future climate change. Here we show that fluctuations in Antarctic Ice Sheet discharge caused by relatively small changes in subsurface ocean temperature can amplify multi-centennial climate variability regionally and globally, suggesting that a dynamic Antarctic Ice Sheet may have driven climate fluctuations during the Holocene. We analysed high-temporal-resolution records of iceberg-rafted debris derived from the Antarctic Ice Sheet, and performed both high-spatial-resolution ice-sheet modelling of the Antarctic Ice Sheet and multi-millennial global climate model simulations. Ice-sheet responses to decadal-scale ocean forcing appear to be less important, possibly indicating that the future response of the Antarctic Ice Sheet will be governed more by long-term anthropogenic warming combined with multi-centennial natural variability than by annual or decadal climate oscillations.
Job satisfaction and short-term sickness absence among Dutch workers.
Notenbomer, Annette; Roelen, Corné A M; Groothoff, Johan W
2006-06-01
Sickness absence is a considerable economic and social problem. Short-term sickness absence is known to be associated with behavioural attitudes. The correlation between sickness absence and job satisfaction has been studied infrequently and with contradictory results. This study investigated the correlation between short-term sickness absence and both global and specific job satisfaction. We defined short-term sickness absence as spells of up to 42 days. A random sample of 898 Dutch workers from a variety of economic sectors and companies received a self-report questionnaire on their first day of sick leave. The questionnaire measured global and specific job satisfaction. In our regression analysis, we controlled for the confounding factors of age, gender, educational level, perceived workload, job autonomy and decision latitude. The duration of an absence spell was defined as the amount of calendar days between sick leave and return to work. Global job satisfaction did not correlate significantly with the duration of short-term sickness absence. While increasing physical job demands predicted longer absence, increasing job autonomy and educational level predicted shorter absence. Satisfaction with colleagues predicted longer duration absence. Global job satisfaction did not correlate with the duration of short-term absence spells, but specific satisfaction with colleagues was associated with longer sickness spells.
Yin, Xuwang; Chen, Peng; Chen, Hai; Jin, Wen; Yan, Xiwu
2017-01-01
Intertidal organisms, especially the sessile species, often experience long-term periodic air exposure during their lives. Learning the biochemical and physiological responses of intertidal organisms to long-term periodic air exposure and the relationship to duration of air exposure provides insight into adaptation to this variably stressful environment. We studied the Manila clam, Ruditapes philippinarum, an important species in world aquaculture, as a model to evaluate survival, growth, lipid composition, oxygen consumption, oxidative damage, and antioxidant enzyme activity in relation to the duration of air exposure in a long-term (60 days) laboratory study of varying durations of periodic emersion and re-immersion. Our results show: (1) clams undergoing a longer period of air exposure had lower survival and growth compared to those given a shorter exposure, (2) levels of oxidative damage and activities of antioxidant enzymes were higher in all air exposure treatments, but did not increase with duration of air exposure, and (3) the content of docosahexaenoic acid increased with duration of air exposure. Our results can largely be interpreted in the context of the energy expenditure by the clams caused by aerobic metabolism during the daily cycle of emersion and re-immersion and the roles of docosahexaenoic acid against oxidative stress. PMID:28128354
Yamaguchi, Kyohei; Lear, Christopher A; Beacom, Michael J; Ikeda, Tomoaki; Gunn, Alistair J; Bennet, Laura
2018-01-08
Fetal heart rate variability is a critical index of fetal wellbeing. Suppression of heart rate variability may provide prognostic information on the risk of hypoxic-ischaemic brain injury after birth. In the present study, we report the evolution of fetal heart rate variability after both mild and severe hypoxia-ischaemia. Both mild and severe hypoxia-ischaemia were associated with an initial, brief suppression of multiple measures of heart rate variability. This was followed by normal or increased levels of heart rate variability during the latent phase of injury. Severe hypoxia-ischaemia was subsequently associated with the prolonged suppression of measures of heart rate variability during the secondary phase of injury, which is the period of time when brain injury is no longer treatable. These findings suggest that a biphasic pattern of heart rate variability may be an early marker of brain injury when treatment or intervention is probably most effective. Hypoxia-ischaemia (HI) is a major contributor to preterm brain injury, although there are currently no reliable biomarkers for identifying infants who are at risk. We tested the hypothesis that fetal heart rate (FHR) and FHR variability (FHRV) would identify evolving brain injury after HI. Fetal sheep at 0.7 of gestation were subjected to either 15 (n = 10) or 25 min (n = 17) of complete umbilical cord occlusion or sham occlusion (n = 12). FHR and four measures of FHRV [short-term variation, long-term variation, standard deviation of normal to normal R-R intervals (SDNN), root mean square of successive differences) were assessed until 72 h after HI. All measures of FHRV were suppressed for the first 3-4 h in the 15 min group and 1-2 h in the 25 min group. Measures of FHRV recovered to control levels by 4 h in the 15 min group, whereas the 25 min group showed tachycardia and an increase in short-term variation and SDNN from 4 to 6 h after occlusion. The measures of FHRV then progressively declined in the 25 min group and became profoundly suppressed from 18 to 48 h. A partial recovery of FHRV measures towards control levels was observed in the 25 min group from 49 to 72 h. These findings illustrate the complex regulation of FHRV after both mild and severe HI and suggest that the longitudinal analysis of FHR and FHRV after HI may be able to help determine the timing and severity of preterm HI. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.
Pasman, J W; Rotteveel, J J; de Graaf, R; Stegeman, D F; Visco, Y M
1992-12-01
Recent studies on the maturation of auditory brainstem evoked responses (ABRs) present conflicting results, whereas only sparse reports exist with respect to the maturation of middle latency auditory evoked responses (MLRs) and auditory cortical evoked responses (ACRs). The present study reports the effect of preterm birth on the maturation of auditory evoked responses in low risk preterm infants (27-34 weeks conceptional age). The ABRs indicate a consistent trend towards longer latencies for all individual ABR components and towards longer interpeak latencies in preterm infants. The MLR shows longer latencies for early component P0 in preterm infants. The ACRs show a remarkable difference between preterm and term infants. At 40 weeks CA the latencies of ACR components Na and P2 are significantly longer in term infants, whereas at 52 weeks CA the latencies of the same ACR components are shorter in term infants. The results support the hypothesis that retarded myelination of the central auditory pathway is partially responsible for differences found between preterm infants and term infants with respect to late ABR components and early MLR component P0. Furthermore, mild conductive hearing loss in preterm infants may also play its role. A more complex mechanism is implicated to account for the findings noted with respect to MLR component Na and ACR components Na and P2.
Long-term outcomes of pediatric sinus bradycardia.
Chiu, Shuenn-Nan; Lin, Lian-Yu; Wang, Jou-Kou; Lu, Chun-Wei; Chang, Chi-Wei; Lin, Ming-Tai; Hua, Yu Chuan; Lue, Hung-Chi; Wu, Mei-Hwan
2013-09-01
To delineate the long-term outcomes and mechanisms of pediatric sinus bradycardia. Participants with sinus bradycardia who were identified from a survey of 432,166 elementary and high school students, were enrolled 10 years after the survey. The clinical course, heart rate variability, and hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) gene were assessed. A total of 104 (male:female was 60:44; prevalence, 0.025%) participants were observed to have sinus bradycardia at age 15.5 ± 0.2 years with a mean heart rate of 48.4 ± 0.4 beats per minute; 86 study participants (83%) responded to clinical assessment and 37 (36%) underwent laboratory assessment. Athletes composed 37.8% of the study participants. During the extended 10-year follow-up, 15 (17%) of the participants had self-limited syncopal episodes, but none had experienced life-threatening events. According to Holter recordings, none of the participants had heart rate <30 beats per minute or a pause longer than 3 seconds. Compared with 67 age- and sex-matched controls, the variables of heart rate based on the spectral and time domain analysis of the participants with sinus bradycardia were all significantly higher, indicating higher parasympathetic activity. The results of mutation analysis were negative in the HCN4 gene in all of our participants. The long-term outcomes of the children and adolescents with sinus bradycardia identified using school electrocardiographic survey are favorable. Parasympathetic hyperactivity, instead of HCN4 gene mutation, is responsible for the occurrence of sinus bradycardia. Copyright © 2013 Mosby, Inc. All rights reserved.
Long-term variability in the date of monsoon onset over western India
NASA Astrophysics Data System (ADS)
Adamson, George C. D.; Nash, David J.
2013-06-01
The date of onset of the southwest monsoon in western India is critical for farmers as it influences the timing of crop plantation and the duration of the summer rainy season. Identifying long-term variability in the date of monsoon onset is difficult, however, as onset dates derived from the reanalysis of instrumental rainfall data are only available for the region from 1879. This study uses documentary evidence and newly uncovered instrumental data to reconstruct annual monsoon onset dates for western India for the period 1781-1878, extending the existing record by 97 years. The mean date of monsoon onset over the Mumbai (Bombay) area during the reconstruction period was 10 June with a standard deviation of 6.9 days. This is similar to the mean and standard deviation of the date of monsoon onset derived from instrumental data for the twentieth century. The earliest identified onset date was 23 May (in 1802 and 1839) and the latest 22 June (in 1825). The longer-term perspective provided by this study suggests that the climatic regime that governs monsoon advance over western India did not change substantially from 1781 to 1955. Monsoon onset over Mumbai has occurred at a generally later date since this time. Our results indicate that this change is unprecedented during the last 230 years. Following a discussion of the results, the nature of the relationship between the date of monsoon onset and the El Niño-Southern Oscillation is discussed. This relationship is shown to have been stable since 1781.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy
Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well-constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (N a). These terms are further parameterized, and by assuming that on seasonal timescales N a is in steady state, the budget equation is rearranged to form a diagnostic equation for Nmore » a based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter N a concentrations are made using the simplified steady-state model and seasonal mean observed variables, and are found to match well with the observed N a. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g. precipitation rate, free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in N a, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.« less
Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; ...
2018-01-21
Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well-constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (N a). These terms are further parameterized, and by assuming that on seasonal timescales N a is in steady state, the budget equation is rearranged to form a diagnostic equation for Nmore » a based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter N a concentrations are made using the simplified steady-state model and seasonal mean observed variables, and are found to match well with the observed N a. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g. precipitation rate, free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in N a, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.« less
The response of the southwest Western Australian wave climate to Indian Ocean climate variability
NASA Astrophysics Data System (ADS)
Wandres, Moritz; Pattiaratchi, Charitha; Hetzel, Yasha; Wijeratne, E. M. S.
2018-03-01
Knowledge of regional wave climates is critical for coastal planning, management, and protection. In order to develop a regional wave climate, it is important to understand the atmospheric systems responsible for wave generation. This study examines the variability of the southwest Western Australian (SWWA) shelf and nearshore wind wave climate and its relationship to southern hemisphere climate variability represented by various atmospheric indices: the southern oscillation index (SOI), the Southern Annular Mode (SAM), the Indian Ocean Dipole Mode Index (DMI), the Indian Ocean Subtropical Dipole (IOSD), the latitudinal position of the subtropical high-pressure ridge (STRP), and the corresponding intensity of the subtropical ridge (STRI). A 21-year wave hindcast (1994-2014) of the SWWA continental shelf was created using the third generation wave model Simulating WAves Nearshore (SWAN), to analyse the seasonal and inter-annual wave climate variability and its relationship to the atmospheric regime. Strong relationships between wave heights and the STRP and the STRI, a moderate correlation between the wave climate and the SAM, and no significant correlation between SOI, DMI, and IOSD and the wave climate were found. Strong spatial, seasonal, and inter-annual variability, as well as seasonal longer-term trends in the mean wave climate were studied and linked to the latitudinal changes in the subtropical high-pressure ridge and the Southern Ocean storm belt. As the Southern Ocean storm belt and the subtropical high-pressure ridge shifted southward (northward) wave heights on the SWWA shelf region decreased (increased). The wave height anomalies appear to be driven by the same atmospheric conditions that influence rainfall variability in SWWA.
NASA Astrophysics Data System (ADS)
Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; Eastman, Ryan; Luke, Edward
2018-01-01
Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (Na). These terms are then parameterized, and by assuming that on seasonal time scales Na is in steady state, the budget equation is rearranged to form a diagnostic equation for Na based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-Section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter Na concentrations are made using the simplified steady state model and seasonal mean observed variables. These are found to match well with the observed Na. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g., precipitation rate and free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in Na, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.
Modestin, J; Stephan, P L; Erni, T; Umari, T
2000-05-05
In 200 inpatients on regular neuroleptics, point prevalence of extrapyramidal syndromes, including Parkinson syndrome, akathisia and tardive dyskinesia (TD), was studied and found to be 20, 11 and 22%, respectively. A total of 46 patients have currently, and for a longer time, (average about 3years, median over 1year) been treated with clozapine, and 127 with typical neuroleptics (NLs). Comparing both groups, higher TD scores were found in the clozapine sample. Investigating the influence of a set of seven clinical variables on the TD score with the help of multiple regression analysis, the influence of the treatment modality disappeared, whereas the age proved to be the only significant variable. Studying the role of past clozapine therapy in patients currently on typical NLs and comparing 10 matched pairs of chronic patients with and without TD in whom a complete life-time cumulative dose of NLs was identified, a relationship between TD and length of current typical NL therapy and life-time typical NL dosage could be demonstrated. On the whole, long-term relatively extensive use of clozapine has not markedly reduced the prevalence of extrapyramidal syndromes in our psychiatric inpatient population. In particular, we failed to demonstrate a beneficial effect of clozapine on prevalence of TD. There are certainly patients who suffer from TD in spite of a long-term intensive clozapine treatment.
Atmospheric composition - Influence of biology
NASA Technical Reports Server (NTRS)
Mcelroy, M. B.
1983-01-01
The variability of atmospheric constituents influenced by biological organisms over various time scales is examined, together with the human contribution to atmospheric sulfur. The biogeochemistry of nitrogen is discussed, with an emphasis on N2O, NO, and microbially mediated reactions in soil and water. Carbon species are bound up mainly in sediments and the deep ocean, but human activities involving combustion may cause a doubling of the atmospheric levels of CO2 in the near future, which could produce a general low-level atmospheric warming. Longer term measurements are required to assess the effects of CH4 augmentation in the atmosphere through fuel combustion. Coal burning effectively doubles the amount of SO2 produced by natural sources, and reduces the pH of rainwater, thus posing hazards to fish, plankton, and mollusc life.
Hahn, Robert A; Rammohan, Veda; Truman, Benedict I; Milstein, Bobby; Johnson, Robert L; Muntañer, Carles; Jones, Camara P; Fullilove, Mindy T; Chattopadhyay, Sajal K; Hunt, Pete C; Abraido-Lanza, Ana F
2014-03-01
Children from low-income and minority families are often behind higher-income and majority children in language, cognitive, and social development even before they enter school. Because educational achievement has been shown to improve long-term health, addressing these delays may foster greater health equity. This systematic review assesses the extent to which full-day kindergarten (FDK), compared with half-day kindergarten (HDK), prepares children, particularly those from low-income and minority families, to succeed in primary and secondary school and improve lifelong health. A meta-analysis (2010) on the effects of FDK versus HDK among U.S. children measured educational achievement at the end of kindergarten. The meta-analysis was concordant with Community Guide criteria. Findings on the longer-term effects of FDK suggested "fade-out" by third grade. The present review used evidence on the longer-term effects of pre-K education to explore the loss of FDK effects over time. FDK improved academic achievement by an average of 0.35 SDs (Cohen's d; 95% CI=0.23, 0.46). The effect on verbal achievement was 0.46 (Cohen's d; 95% CI=0.32, 0.61) and that on math achievement was 0.24 (Cohen's d; 95% CI=0.06, 0.43). Evidence of "fade-out" from pre-K education found that better-designed studies indicated both residual benefits over multiple years and the utility of educational boosters to maintain benefits, suggesting analogous longer-term effects of FDK. There is strong evidence that FDK improves academic achievement, a predictor of longer-term health benefits. To sustain early benefits, intensive elementary school education is needed. If targeted to low-income and minority communities, FDK can advance health equity. Published by Elsevier Inc.
Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.
2014-01-01
The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.
An evidence-based framework to measure quality of allied health care.
Grimmer, Karen; Lizarondo, Lucylynn; Kumar, Saravana; Bell, Erica; Buist, Michael; Weinstein, Philip
2014-02-26
There is no standard way of describing the complexities of allied health (AH) care, or its quality. AH is an umbrella term which excludes medicine and nursing, and variably includes disciplines which provide therapy, diagnostic, or scientific services. This paper outlines a framework for a standard approach to evaluate the quality of AH therapy services. A realist synthesis framework describing what AH does, how it does it, and what is achieved, was developed. This was populated by the findings of a systematic review of literature published since 1980 reporting concepts of quality relevant to AH. Articles were included on quality measurement concepts, theories, debates, and/or hypothetical frameworks. Of 139 included articles, 21 reported on descriptions of quality potentially relevant to AH. From these, 24 measures of quality were identified, with 15 potentially relating to what AH does, 17 to how AH delivers care, 8 relating to short term functional outcomes, and 9 relating to longer term functional and health system outcomes. A novel evidence-based quality framework was proposed to address the complexity of AH therapies. This should assist in better evaluation of AH processes and outcomes, costs, and evidence-based engagement of AH providers in healthcare teams.
Herring, Garth; Eagles-Smith, Collin A; Gawlik, Dale E; Beerens, James M; Ackerman, Joshua T
2014-01-01
The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.
Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.
2014-01-01
The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks. PMID:25184221
Heinitz, Sascha; Reinhardt, Martin; Piaggi, Paolo; Weise, Christopher M; Diaz, Enrique; Stinson, Emma J; Venti, Colleen; Votruba, Susanne B; Wassermann, Eric M; Alonso-Alonso, Miguel; Krakoff, Jonathan; Gluck, Marci E
2017-12-01
Background: Obesity is associated with reduced activation in the left dorsolateral prefrontal cortex (DLPFC), a region of the brain that plays a key role in the support of self-regulatory aspects of eating behavior and inhibitory control. Transcranial direct current stimulation (tDCS) is a noninvasive technique used to modulate brain activity. Objectives: We tested whether repeated anodal tDCS targeted at the left DLPFC (compared with sham tDCS) has an immediate effect on eating behavior during ad libitum food intake, resulting in weight change, and whether it might influence longer-term food intake-related appetite ratings in individuals with obesity. Design: In a randomized parallel-design study combining inpatient and outpatient assessments over 31 d, 23 individuals with obesity [12 men; mean ± SD body mass index (BMI; in kg/m 2 ): 39.3 ± 8.42] received 15 sessions of anodal (i.e., enhancing cortical activity) or sham tDCS aimed at the left DLPFC. Ad libitum food intake was assessed through the use of a vending machine paradigm and snack food taste tests (SFTTs). Appetite was evaluated with a visual analog scale (VAS). Body weight was measured. We examined the effect of short-term (i.e., 3 sessions) and long-term (i.e., 15 sessions) tDCS on these variables. Results: Relative to sham tDCS, short-term anodal tDCS did not influence ad libitum intake of food from the vending machines. Accordingly, no effect on short-term or 4-wk weight change was observed. In the anodal tDCS group, compared with the sham group, VAS ratings for hunger and the urge to eat declined significantly more ( P = 0.01 and P = 0.05, respectively), and total energy intake during an SFTT was relatively lower in satiated individuals ( P = 0.01), after long-term tDCS. Conclusions: Short-term anodal tDCS of the left DLPFC did not have an immediate effect on ad libitum food intake or thereby weight change, relative to sham tDCS. Hunger and snack food intake were reduced only after a longer period of anodal tDCS in individuals with obesity. This trial was registered at clinicaltrials.gov as NCT00739362. © 2017 American Society for Nutrition.
Musgrove, MaryLynn; Opsahl, Stephen P.; Mahler, Barbara J.; Herrington, Chris; Sample, Thomas; Banta, John
2016-01-01
Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO3−) loading to surface and groundwater. We investigate variability and sources of NO3− in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO3− stable isotopes (δ15N and δ18O). These data were augmented by historical data collected from 1937 to 2007. NO3− concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO3− concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO3− concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO3−. These results highlight the vulnerability of karst aquifers to NO3− contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO3−than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a previously unrecognized source of NO3− to karst groundwater or other oxic groundwater systems.
Knight, Michael J.; Smith-Collins, Adam; Newell, Sarah; Denbow, Mark; Kauppinen, Risto A.
2017-01-01
Background and Purpose Preterm birth is associated with worse neurodevelopmental outcome, but brain maturation in preterm infants is poorly characterised with standard methods. We evaluated white matter (WM) of infant brains at term-equivalent age, as a function of gestational age at birth, using multi-modal MRI. Methods Infants born very pre-term (< 32 weeks gestation) and late pre-term (33-36 weeks gestation) were scanned at 3T at term-equivalent age using diffusion tensor imaging (DTI) and T2 relaxometry. MRI data were analysed using tract-based spatial statistics, and anisotropy of T2 relaxation was also determined. Principal component analysis and linear discriminant analysis were applied to seek the variables best distinguishing very pre-term and late pre-term groups. Results Across widespread regions of WM, T2 is longer in very pre-term infants than in late pre-term ones. These effects are more prevalent in regions of WM which myelinate earlier and faster. Similar effects are obtained from DTI, showing that fractional anisotropy (FA) is lower and radial diffusivity higher in the very pre-term group, with a bias towards earlier myelinating regions. Discriminant analysis shows high sensitivity and specificity of combined T2 relaxometry and DTI for the detection of a distinct WM development pathway in very preterm infants. T2 relaxation is anisotropic, depending on the angle between WM fibre and magnetic field, and this effect is modulated by FA. Conclusions Combined T2 relaxometry and DTI characterises specific patterns of retarded WM maturation, at term equivalent age, in infants born very pre-term relative to late pre-term. PMID:29205635
Trathan, P N; Forcada, J; Murphy, E J
2007-12-29
The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño-Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in different regional food webs, there is the potential to make predictions about future change scenarios.
Lengyel, Csaba; Orosz, Andrea; Hegyi, Péter; Komka, Zsolt; Udvardy, Anna; Bosnyák, Edit; Trájer, Emese; Pavlik, Gábor; Tóth, Miklós; Wittmann, Tibor; Papp, Julius Gy.; Varró, András; Baczkó, István
2011-01-01
Background Sudden cardiac death in competitive athletes is rare but it is significantly more frequent than in the normal population. The exact cause is seldom established and is mostly attributed to ventricular fibrillation. Myocardial hypertrophy and slow heart rate, both characteristic changes in top athletes in response to physical conditioning, could be associated with increased propensity for ventricular arrhythmias. We investigated conventional ECG parameters and temporal short-term beat-to-beat variability of repolarization (STVQT), a presumptive novel parameter for arrhythmia prediction, in professional soccer players. Methods Five-minute 12-lead electrocardiograms were recorded from professional soccer players (n = 76, all males, age 22.0±0.61 years) and age-matched healthy volunteers who do not participate in competitive sports (n = 76, all males, age 22.0±0.54 years). The ECGs were digitized and evaluated off-line. The temporal instability of beat-to-beat heart rate and repolarization were characterized by the calculation of short-term variability of the RR and QT intervals. Results Heart rate was significantly lower in professional soccer players at rest (61±1.2 vs. 72±1.5/min in controls). The QT interval was prolonged in players at rest (419±3.1 vs. 390±3.6 in controls, p<0.001). QTc was significantly longer in players compared to controls calculated with Fridericia and Hodges correction formulas. Importantly, STVQT was significantly higher in players both at rest and immediately after the game compared to controls (4.8±0.14 and 4.3±0.14 vs. 3.5±0.10 ms, both p<0.001, respectively). Conclusions STVQT is significantly higher in professional soccer players compared to age-matched controls, however, further studies are needed to relate this finding to increased arrhythmia propensity in this population. PMID:21526208
NASA Technical Reports Server (NTRS)
Solomon, S.; Portmann, R. W.; Garcia, R. R.; Randel, W.; Wu, F.; Nagatani, R.; Gleason, J.; Thomason, L.; Poole, L. R.; McCormick, M. P.
1998-01-01
Satellite observations of total ozone at 40-60 deg N are presented from a variety of instruments over the time period 1979-1997. These reveal record low values in 1992-3 (after Pinatubo) followed by partial but incomplete recovery. The largest post-Pinatubo reductions and longer-term trends occur in spring, providing a critical test for chemical theories of ozone depletion. The observations are shown to be consistent with current understanding of the chemistry of ozone depletion when changes in reactive chlorine and stratospheric aerosol abundances are considered along with estimates of wave-driven fluctuations in stratospheric temperatures derived from global temperature analyses. Temperature fluctuations are shown to make significant contributions to model calculated northern mid-latitude ozone depletion due to heterogeneous chlorine activation on liquid sulfate aerosols at temperatures near 200-210 K (depending upon water vapor pressure), particularly after major volcanic eruptions. Future mid-latitude ozone recovery will hence depend not only on chlorine recovery but also on temperature trends and/or variability, volcanic activity, and any trends in stratospheric sulfate aerosol.
Control of growth of juvenile leaves of Eucalyptus globulus: effects of leaf age.
Metcalfe, J C; Davies, W J; Pereira, J S
1991-12-01
Biophysical variables influencing the expansion of plant cells (yield threshold, cell wall extensibility and turgor) were measured in individual Eucalyptus globulus leaves from the time of emergence until cessation of growth. Leaf water relations variables and growth rates were determined as relative humidity was changed on an hourly basis. Yield threshold and cell wall extensibility were estimated from plots of leaf growth rate versus turgor. Cell wall extensibility was also measured by the Instron technique, and yield threshold was determined experimentally both by stress relaxation in a psychrometer chamber and by incubation in a range of polyethylene glycol solutions. Once emerging leaves reached approximately 5 cm(2) in size, increases in leaf area were rapid throughout the expansive phase and varied little between light and dark periods. Both leaf growth rate and turgor were sensitive to changes in humidity, and in the longer term, both yield threshold and cell wall extensibility changed as the leaf aged. Rapidly expanding leaves had a very low yield threshold and high cell wall extensibility, whereas mature leaves had low cell wall extensibility. Yield threshold increased with leaf age.
A 3,500-year tree-ring record of annual precipitation on the northeastern Tibetan Plateau.
Yang, Bao; Qin, Chun; Wang, Jianglin; He, Minhui; Melvin, Thomas M; Osborn, Timothy J; Briffa, Keith R
2014-02-25
An annually resolved and absolutely dated ring-width chronology spanning 4,500 y has been constructed using subfossil, archaeological, and living-tree juniper samples from the northeastern Tibetan Plateau. The chronology represents changing mean annual precipitation and is most reliable after 1500 B.C. Reconstructed precipitation for this period displays a trend toward more moist conditions: the last 10-, 25-, and 50-y periods all appear to be the wettest in at least three and a half millennia. Notable historical dry periods occurred in the 4th century BCE and in the second half of the 15th century CE. The driest individual year reconstructed (since 1500 B.C.) is 1048 B.C., whereas the wettest is 2010. Precipitation variability in this region appears not to be associated with inferred changes in Asian monsoon intensity during recent millennia. The chronology displays a statistical association with the multidecadal and longer-term variability of reconstructed mean Northern Hemisphere temperatures over the last two millennia. This suggests that any further large-scale warming might be associated with even greater moisture supply in this region.
From the Kochen-Specker theorem to noncontextuality inequalities without assuming determinism.
Kunjwal, Ravi; Spekkens, Robert W
2015-09-11
The Kochen-Specker theorem demonstrates that it is not possible to reproduce the predictions of quantum theory in terms of a hidden variable model where the hidden variables assign a value to every projector deterministically and noncontextually. A noncontextual value assignment to a projector is one that does not depend on which other projectors-the context-are measured together with it. Using a generalization of the notion of noncontextuality that applies to both measurements and preparations, we propose a scheme for deriving inequalities that test whether a given set of experimental statistics is consistent with a noncontextual model. Unlike previous inequalities inspired by the Kochen-Specker theorem, we do not assume that the value assignments are deterministic and therefore in the face of a violation of our inequality, the possibility of salvaging noncontextuality by abandoning determinism is no longer an option. Our approach is operational in the sense that it does not presume quantum theory: a violation of our inequality implies the impossibility of a noncontextual model for any operational theory that can account for the experimental observations, including any successor to quantum theory.
NASA Astrophysics Data System (ADS)
Adams, K. D.; Negrini, R. M.; Rajagopal, S.; Cook, E. R.
2015-12-01
The Central Valley of California is one of the most prolific agricultural areas in the U.S., providing about 25 % of the nation's food. This system is reliant on winter snows in the Sierra Nevada that gradually melt through the spring, but over the last 4 years California has been in the grip of its worst drought of the last 150 years. The question remains, however, how unusual is this drought when compared to previous events over longer time scales? We used moisture sensitive tree-ring chronologies from the Living Blended Drought Atlas of Cook et al. (2010) to reconstruct annual discharges over the last 2000 years for the Kings, Kaweah, Tule, and Kern rivers in the southern Sierra and routed this discharge into a Tulare Lake water balance model to simulate lake-level fluctuations over this same time period. Although the current drought represents the driest consecutive four year period over the past 2000 years, in terms of discharge volumes, there are multiple periods of more severe, longer term drought represented by extended periods of low lake levels. Significant low-lake periods (< 61 m) include 793-814, 906-933, and 1140-1158, all of which occurred during the Medieval Climate Anomaly. Conversely, lake levels were predominately high during the ensuing Little Ice Age, separated by brief periods of low lake levels. Under natural flow conditions, the 1923-1935 drought would have lowered lake level to about 58 m, which is about 2 m lower than where lake level would have been in the current drought. Wavelet analyses of the streamflow and lake-level records reveal different periodicities of drought and wet conditions because lake-level is a state variable that changes relatively slowly, depending on inflow, precipitation on the lake, evaporation rate, and the hypsometry of the basin, whereas streamflow is a flux that responds immediately to climate perturbations. The streamflow records have a dominant period of 2-8 yrs but lake-level fluctuations follow longer periods of >32 yrs, primarily prior to 1300. While the 2-8 yr periodicity may reflect ENSO cycles, the causes of the longer periods in the lake-level record remain unknown.
Perceptual learning of degraded speech by minimizing prediction error.
Sohoglu, Ediz; Davis, Matthew H
2016-03-22
Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech.
Perceptual learning of degraded speech by minimizing prediction error
Sohoglu, Ediz
2016-01-01
Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech. PMID:26957596
Zhang, Min; Duan, Hongtao; Shi, Xiaoli; Yu, Yang; Kong, Fanxiang
2012-02-01
Cyanobacterial blooms are often a result of eutrophication. Recently, however, their expansion has also been found to be associated with changes in climate. To elucidate the effects of climatic variables on the expansion of cyanobacterial blooms in Taihu, China, we analyzed the relationships between climatic variables and bloom events which were retrieved by satellite images. We then assessed the contribution of each climate variable to the phenology of blooms using multiple regression models. Our study demonstrates that retrieving ecological information from satellite images is meritorious for large-scale and long-term ecological research in freshwater ecosystems. Our results show that the phenological changes of blooms at an inter-annual scale are strongly linked to climate in Taihu during the past 23 yr. Cyanobacterial blooms occur earlier and last longer with the increase of temperature, sunshine hours, and global radiation and the decrease of wind speed. Furthermore, the duration increases when the daily averages of maximum, mean, and minimum temperature each exceed 20.3 °C, 16.7 °C, and 13.7 °C, respectively. Among these factors, sunshine hours and wind speed are the primary contributors to the onset of the blooms, explaining 84.6% of their variability over the past 23 yr. These factors are also good predictors of the variability in the duration of annual blooms and determined 58.9% of the variability in this parameter. Our results indicate that when nutrients are in sufficiently high quantities to sustain the formation of cyanobacterial blooms, climatic variables become crucial in predicting cyanobacterial bloom events. Climate changes should be considered when we evaluate how much the amount of nutrients should be reduced in Taihu for lake management. Copyright © 2011 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Rust, A.; Saxe, S.; Hogue, T. S.; McCray, J. E.
2016-12-01
Increasing wildfire size and frequency in the Western United States creates short-term and long-term impacts on water quality. Surface water in forested watersheds provides water for municipal water supplies and aquatic ecosystems. After fire, increased runoff and erosion lead to elevated loading of nutrients, sediment, and metals. Studies on individual fires have observed mobilization of contaminants, nutrients, metals and sediments into receiving waters. Other studies focused on individual fires over a short period, 1-3 years after fire. The objective of this study is to utilize an extensive historical water quality database, assembled by the authors, to identify trends in post-fire water quality response for the ten years following a significant fire. Specifically, we investigate the variability of post-fire water quality response and determine the key drivers impacting the immediate contaminant flux, recovery over the longer-term and ultimate resiliency of impacted watersheds and municipal water supplies. Results show that the most common post-fire response was increased nutrient loading. Thirty-two western watersheds experienced significant increases in NO3-, NO2-, NH3, and total nitrogen loading for the first five years after fire and remained elevated ten years after fire. Dissolved and total phosphorous significantly increased in 32 western watersheds for the first five years after fire. The majority of these water bodies returned to normal loading after 10 years. Dissolved ions such as calcium, magnesium, and chloride were also exported from over 32 watersheds for the first five years after fire. Using multiple linear regression analysis, we also identify the key physical watershed characteristics that drive post-fire water quality response and recovery. Burn severity, burn area and aridity index all influence the degree of water quality response. Our work provides managers with critical information to evaluate water supply impacts, including short-term treatment needs, as well as the potential long-term resiliency of impacted watersheds.
Hurricane Katrina Impact on Water Quality in the East Pearl River, Mississippi
NASA Astrophysics Data System (ADS)
Shiller, A. M.; Shim, M.; Guo, L.; Bianchi, T. S.; Smith, R. W.; Duan, S.
2010-12-01
Hurricanes and other intense storms have previously been reported to cause short term changes in surface water quality. We examined the water quality of the East Pearl River in southern Mississippi both before and after Hurricane Katrina caused extensive damage to the watershed in 2005. Our post-storm sampling began two months after the hurricane, and thus we missed any immediate short-term consequences. However, sampling over the following two years allowed us to examine whether damage to watershed resulted in significant longer term effects on water quality. Interpretation of the time series data is complicated by the natural seasonal and climatic variability of the system. Thus, we utilized property-property plots as well as empirical relationships to compare pre- and post-storm water quality. Based on the variability of our empirical relationships, we estimate that to within 20%, the hurricane-induced vegetative destruction within this river basin has not changed the concentrations of DOC, POC, SPM, pH, or dissolved Fe. Nor has the quality of the DOC, as inferred from lignin-phenol analysis and the Fe-DOC relationship, been significantly changed either. This may be partly due to the slow degradation of woody materials that occurs only over a period of a few years, even in the sub-tropical climate of this region. Also, transport of DOC material from the land, through the soils, and into the river is not always instantaneous because DOC may stay in soils for a long time. Our work can be examined in the context of other research focused on hurricane effects on different time scales. For instance, shorter term hurricane influences, such as immediate flooding, can cause concurrent, short-lived water quality changes. Likewise, if increased hurricane activity (as might result from climate change) results in permanent landscape or ecosystem changes, then significant long-term water quality changes might be expected.
Why continuous simulation? The role of antecedent moisture in design flood estimation
NASA Astrophysics Data System (ADS)
Pathiraja, S.; Westra, S.; Sharma, A.
2012-06-01
Continuous simulation for design flood estimation is increasingly becoming a viable alternative to traditional event-based methods. The advantage of continuous simulation approaches is that the catchment moisture state prior to the flood-producing rainfall event is implicitly incorporated within the modeling framework, provided the model has been calibrated and validated to produce reasonable simulations. This contrasts with event-based models in which both information about the expected sequence of rainfall and evaporation preceding the flood-producing rainfall event, as well as catchment storage and infiltration properties, are commonly pooled together into a single set of "loss" parameters which require adjustment through the process of calibration. To identify the importance of accounting for antecedent moisture in flood modeling, this paper uses a continuous rainfall-runoff model calibrated to 45 catchments in the Murray-Darling Basin in Australia. Flood peaks derived using the historical daily rainfall record are compared with those derived using resampled daily rainfall, for which the sequencing of wet and dry days preceding the heavy rainfall event is removed. The analysis shows that there is a consistent underestimation of the design flood events when antecedent moisture is not properly simulated, which can be as much as 30% when only 1 or 2 days of antecedent rainfall are considered, compared to 5% when this is extended to 60 days of prior rainfall. These results show that, in general, it is necessary to consider both short-term memory in rainfall associated with synoptic scale dependence, as well as longer-term memory at seasonal or longer time scale variability in order to obtain accurate design flood estimates.
Breshears, D.D.; Kirchner, T.B.; Whicker, J.J.; Field, J.P.; Allen, Craig D.
2012-01-01
Aeolian sediment transport is a fundamental process redistributing sediment, nutrients, and contaminants in dryland ecosystems. Over time frames of centuries or longer, horizontal sediment fluxes and associated rates of contaminant transport are likely to be influenced by succession, disturbances, and changes in climate, yet models of horizontal sediment transport that account for these fundamental factors are lacking, precluding in large part accurate assessment of human health risks associated with persistent soil-bound contaminants. We present a simple model based on empirical measurements of horizontal sediment transport (predominantly saltation) to predict potential contaminant transport rates for recently disturbed sites such as a landfill cover. Omnidirectional transport is estimated within vegetation that changes using a simple Markov model that simulates successional trajectory and considers three types of short-term disturbances (surface fire, crown fire, and drought-induced plant mortality) under current and projected climates. The model results highlight that movement of contaminated soil is sensitive to vegetation dynamics and increases substantially (e.g., > fivefold) when disturbance and/or future climate are considered. The time-dependent responses in horizontal sediment fluxes and associated contaminant fluxes were sensitive to variability in the timing of disturbance, with longer intervals between disturbance allowing woody plants to become dominant and crown fire and drought abruptly reducing woody plant cover. Our results, which have direct implications for contaminant transport and landfill management in the specific context of our assessment, also have general relevance because they highlight the need to more fully account for vegetation dynamics, disturbance, and changing climate in aeolian process studies.
Winter, York; Schaefers, Andrea T U
2011-03-30
Behavioral experiments based on operant procedures can be time-consuming for small amounts of data. While individual testing and handling of animals can influence attention, emotion, and behavior, and interfere with experimental outcome, many operant protocols require individual testing. We developed an RFID-technology- and transponder-based sorting system that allows removing the human factor for longer-term experiments. Identity detectors and automated gates route mice individually from their social home cage to an adjacent operant compartment with 24/7 operation. CD1-mice learnt quickly to individually pass through the sorting system. At no time did more than a single mouse enter the operant compartment. After 3 days of adjusting to the sorting system, groups of 4 mice completed about 50 experimental trials per day in the operant compartment without experimenter intervention. The automated sorting system eliminates handling, isolation, and disturbance of the animals, eliminates experimenter-induced variability, saves experimenter time, and is financially economical. It makes possible a new approach for high-throughput experimentation, and is a viable tool for increasing quality and efficiency of many behavioral and neurobiological investigations. It can connect a social home cage, through individual sorting automation, to diverse setups including classical operant chambers, mazes, or arenas with video-based behavior classification. Such highly automated systems will permit efficient high-throughput screening even for transgenic animals with only subtle neurological or psychiatric symptoms where elaborate or longer-term protocols are required for behavioral diagnosis. Copyright © 2011 Elsevier B.V. All rights reserved.
Sheridan, Scott C; Lin, Shao
2014-12-01
While the impacts of heat upon mortality and morbidity have been frequently studied, few studies have examined the relationship between heat, morbidity, and mortality across the same events. This research assesses the relationship between heat events and morbidity and mortality in New York City for the period 1991-2004. Heat events are defined based on oppressive weather types as determined by the Spatial Synoptic Classification. Morbidity data include hospitalizations for heat-related, respiratory, and cardiovascular causes; mortality data include these subsets as well as all-cause totals. Distributed-lag models assess the relationship between heat and health outcome for a cumulative 15-day period following exposure. To further refine analysis, subset analyses assess the differences between early- and late-season events, shorter and longer events, and earlier and later years. The strongest heat-health relationships occur with all-cause mortality, cardiovascular mortality, and heat-related hospital admissions. The impacts of heat are greater during longer heat events and during the middle of summer, when increased mortality is still statistically significant after accounting for mortality displacement. Early-season heat waves have increases in mortality that appear to be largely short-term displacement. The impacts of heat on mortality have decreased over time. Heat-related hospital admissions have increased during this time, especially during the earlier days of heat events. Given the trends observed, it suggests that a greater awareness of heat hazards may have led to increased short-term hospitalizations with a commensurate decrease in mortality.
[Profile of human milk bank donors and relationship with the length of the donation].
Sierra Colomina, G; García Lara, N; Escuder Vieco, D; Vázquez Román, S; Cabañes Alonso, E; Pallás Alonso, C R
2014-04-01
The promotion of Human Milk Banks is an important social service. The Human Milk Banks depend on donors, and knowing the profile of donors seems quite important. To study the demographics and lifestyles of the donors, the reasons or influences for donating, and to associate these variables with the length of the donation. This is a descriptive, cross-sectional study conducted on 168 mothers who answered the written questionnaire when they agreed to become donors. 98 (58%) responded to the telephone interview. The mean age was 33.1 ± 4.5 years. Of the total 27.9% lived outside Madrid and 21.4% were immigrants, with 23.7% working full time, 65.3% had a university education, and 96.2% had a stable partner. The main reasons for donating were too much milk (77%), and to help others (75%). The main obstacle was transportation to the Human Milk Bank for 20% of the donors, and for 61% the main reason for terminating donation was due to reaching the end of lactation. A longer donation is associated with: having a term newborn, with birth weight over 1500 g, starting donating early and reconciling the donation to the work situation. The most common donor profile was a young woman, with university education and a stable partner. Having a term new born, starting donating early, and the conciliation with work is associated with longer donations. Milk pick-up at home would make donation easier. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kinzey, B. R.; Davis, R. G.
2014-09-30
On the I-35W Bridge in Minneapolis, Minnesota, the GATEWAY program conducted a two-phase demonstration of LED roadway lighting on the main span, which is one of the country's oldest continuously operated exterior LED lighting installations. The Phase II report documents longer-term performance of the LED lighting system that was installed in 2008, and is the first report on the longer-term performance of LED lighting in the field.
NASA earth science and applications division: The program and plans for FY 1988-1989-1990
NASA Technical Reports Server (NTRS)
1988-01-01
Described here are the Division's research goals, priorities and emphases for the next several years and an outline of longer term plans. Included are highlights of recent accomplishments, current activities in FY 1988, research emphases in FY 1989, and longer term future plans. Data and information systems, the Geodynamics Program, the Land Processes Program, the Oceanic Processes Program, the Atmospheric Dynamics and Radiation Program, the Atmospheric Chemistry Program, and space flight programs are among the topic covered.
NASA Astrophysics Data System (ADS)
Haff, P. K.
2012-12-01
Technological modification of the earth's surface (e.g., agriculture, urbanization) is an old story in human history, but what about the future? The future of landscape in an accelerating technological world, beyond a relatively short time horizon, lies hidden behind an impenetrable veil of complexity. Sufficiently complex dynamics generates not only the trajectory of a variable of interest (e.g., vegetation cover) but also the environment in which that variable evolves (e.g., background climate). There is no way to anticipate what variables will define that environment—the dynamics creates its own variables. We are always open to surprise by a change of conditions we thought or assumed were fixed or by the appearance of new phenomena of whose possible existence we had been unaware or thought unlikely. This is especially true under the influence of technology, where novelty is the rule. Lack of direct long-term predictability of landscape change does not, however, mean we cannot say anything about its future. The presence of persistence (finite time scales) in a system means that prediction by a calibrated numerical model should be good for a limited period of time barring bad luck or faulty implementation. Short-term prediction, despite its limitations, provides an option for dealing with the longer-term future. If a computer-controlled car tries to drive itself from New York to Los Angeles, no conceivable (or possible) stand-alone software can be constructed to predict a priori the space-time trajectory of the vehicle. Yet the drive is normally completed easily by most drivers. The trip is successfully completed because each in a series of very short (linear) steps can be "corrected" on the fly by the driver, who takes her cues from the environment to keep the car on the road and headed toward its destination. This metaphor differs in a fundamental way from the usual notion of predicting geomorphic change, because it involves a goal—to reach a desired destination—whereas the natural evolution of landscape has no such goal. Goals will become an essential feature of landscape prediction. The presence of a goal potentially increases our ability to predict, provided it is possible to use feedback (i.e., management) to nudge the system back in the "right" direction when it starts to stray. Under a regime of accelerating technology the closest we can get to predicting the longer term future of landscape is adaptive management, which at large scale is really geoengineer the system. The goal presumably would be to maintain a condition conducive to human well-being, for example to maintain a suitable fraction of global arable land. A successful "prediction" would be to stay within an envelope of states consistent with that goal. We cannot say, however, in what specific state the landscape will be at any time beyond the near future; this will depend on the future sequence of management decisions, which are, like the system they are managing, unpredictable, except shortly before they are implemented. The landscape of the future will thus likely be the result of a series of quick fixes to previous trends in landscape change. Similar comments apply to the prediction, or management, of climate. There is of course no guarantee that it will be possible to stay within the desired envelope of well-being.
Reconstructing pre-instrumental streamflow in Eastern Australia using a water balance approach
NASA Astrophysics Data System (ADS)
Tozer, C. R.; Kiem, A. S.; Vance, T. R.; Roberts, J. L.; Curran, M. A. J.; Moy, A. D.
2018-03-01
Streamflow reconstructions based on paleoclimate proxies provide much longer records than the short instrumental period records on which water resource management plans are currently based. In Australia there is a lack of in-situ high resolution paleoclimate proxy records, but remote proxies with teleconnections to Australian climate have utility in producing streamflow reconstructions. Here we investigate, via a case study for a catchment in eastern Australia, the novel use of an Antarctic ice-core based rainfall reconstruction within a Budyko-framework to reconstruct ∼1000 years of annual streamflow. The resulting streamflow reconstruction captures interannual to decadal variability in the instrumental streamflow, validating both the use of the ice core rainfall proxy record and the Budyko-framework method. In the preinstrumental era the streamflow reconstruction shows longer wet and dry epochs and periods of streamflow variability that are higher than observed in the instrumental era. Importantly, for both the instrumental record and preinstrumental reconstructions, the wet (dry) epochs in the rainfall record are shorter (longer) in the streamflow record and this non-linearity must be considered when inferring hydroclimatic risk or historical water availability directly from rainfall proxy records alone. These insights provide a better understanding of present infrastructure vulnerability in the context of past climate variability for eastern Australia. The streamflow reconstruction presented here also provides a better understanding of the range of hydroclimatic variability possible, and therefore represents a more realistic baseline on which to quantify the potential impacts of anthropogenic climate change on water security.
Caster, Joshua J.; Sankey, Joel B.
2016-04-11
In this study, we examine rainfall datasets of varying temporal length, resolution, and spatial distribution to characterize rainfall depth, intensity, and seasonality for monitoring stations along the Colorado River within Marble and Grand Canyons. We identify maximum separation distances between stations at which rainfall measurements might be most useful for inferring rainfall characteristics at other locations. We demonstrate a method for applying relations between daily rainfall depth and intensity, from short-term high-resolution data to lower-resolution longer-term data, to synthesize a long-term record of daily rainfall intensity from 1950–2012. We consider the implications of our spatio-temporal characterization of rainfall for understanding local landscape change in sedimentary deposits and archaeological sites, and for better characterizing past and present rainfall and its potential role in overland flow erosion within the canyons. We find that rainfall measured at stations within the river corridor is spatially correlated at separation distances of tens of kilometers, and is not correlated at the large elevation differences that separate stations along the Colorado River from stations above the canyon rim. These results provide guidance for reasonable separation distances at which rainfall measurements at stations within the Grand Canyon region might be used to infer rainfall at other nearby locations along the river. Like other rugged landscapes, spatial variability between rainfall measured at monitoring stations appears to be influenced by canyon and rim physiography and elevation, with preliminary results suggesting the highest elevation landform in the region, the Kaibab Plateau, may function as an important orographic influence. Stations at specific locations within the canyons and along the river, such as in southern (lower) Marble Canyon and eastern (upper) Grand Canyon, appear to have strong potential to receive high-intensity rainfall that can generate runoff which may erode alluvium. The characterization of past and present rainfall variability in this study will be useful for future studies that evaluate more spatially continuous datasets in order to better understand the rainfall dynamics within this, and potentially other, deep canyons.
Wray, Faye; Clarke, David
2017-10-06
To review and synthesise qualitative literature relating to the longer-term needs of community dwelling stroke survivors with communication difficulties including aphasia, dysarthria and apraxia of speech. Systematic review and thematic synthesis. We included studies employing qualitative methodology which focused on the perceived or expressed needs, views or experiences of stroke survivors with communication difficulties in relation to the day-to-day management of their condition following hospital discharge. We searched MEDLINE, EMBASE, PsycINFO, CINAHL, The Cochrane Library, International Bibliography of the Social Sciences and AMED and undertook grey literature searches. Studies were assessed for methodological quality by two researchers independently and the findings were combined using thematic synthesis. Thirty-two studies were included in the thematic synthesis. The synthesis reveals the ongoing difficulties stroke survivors can experience in coming to terms with the loss of communication and in adapting to life with a communication difficulty. While some were able to adjust, others struggled to maintain their social networks and to participate in activities which were meaningful to them. The challenges experienced by stroke survivors with communication difficulties persisted for many years poststroke. Four themes relating to longer-term need were developed: managing communication outside of the home, creating a meaningful role, creating or maintaining a support network and taking control and actively moving forward with life. Understanding the experiences of stroke survivors with communication difficulties is vital for ensuring that longer-term care is designed according to their needs. Wider psychosocial factors must be considered in the rehabilitation of people with poststroke communication difficulties. Self-management interventions may be appropriate to help this subgroup of stroke survivors manage their condition in the longer-term; however, such approaches must be designed to help survivors to manage the unique psychosocial consequences of poststroke communication difficulties. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Recent slowing of Atlantic overturning circulation as a recovery from earlier strengthening
NASA Astrophysics Data System (ADS)
Jackson, Laura C.; Peterson, K. Andrew; Roberts, Chris D.; Wood, Richard A.
2016-07-01
The Atlantic meridional overturning circulation (AMOC) has weakened substantially over the past decade. Some weakening may already have occurred over the past century, and global climate models project further weakening in response to anthropogenic climate change. Such a weakening could have significant impacts on the surface climate. However, ocean model simulations based on historical conditions have often found an increase in overturning up to the mid-1990s, followed by a decrease. It is therefore not clear whether the observed weakening over the past decade is part of decadal variability or a persistent weakening. Here we examine a state-of-the-art global-ocean reanalysis product, GloSea5, which covers the years 1989 to 2015 and closely matches observations of the AMOC at 26.5° N, capturing the interannual variability and decadal trend with unprecedented accuracy. The reanalysis data place the ten years of observations--April 2004 to February 2014--into a longer-term context and suggest that the observed decrease in the overturning circulation is consistent with a recovery following a previous increase. We find that density anomalies that propagate southwards from the Labrador Sea are the most likely cause of these variations. We conclude that decadal variability probably played a key role in the decline of the AMOC observed over the past decade.
Solar Spectral Irradiance Reconstruction over 9 Millennia from a Composite 14C and 10Be Series
NASA Astrophysics Data System (ADS)
Wu, C. J.; Usoskin, I. G.; Krivova, N.; Kovaltsov, G.; Solanki, S. K.
2017-12-01
The Sun is the main external energy source to the Earth and thus the knowledge of solar variability on different time scales is important for understanding the solar influence on the terrestrial atmosphere and climate. The overall energy input and its spectral distribution are described by the total (TSI) and spectral (SSI) solar irradiance, respectively. Direct measurements of the solar irradiance provide information on solar variability on the decadal and shorter time scales, while the sunspot number record covers four centuries. On yet longer time scales only indirect proxies can be used, such as the concentrations of the cosmogenic isotopes 10Be and 14C in terrestrial archives. These isotopes are produced in the terrestrial atmosphere by impinging cosmic rays, whose flux is modulated by solar activity. Therefore the isotope data retrieved from various natural archives around the globe show a very high degree of similarity reflecting changes in the solar activity. Nevertheless, significant short-term deviations can be observed due to the different geochemical production processes and local climatic conditions. We will present the newest TSI/SSI reconstruction over the last 9000 years based on a new consistent composite multi-isotope proxy series. The solar irradiance reconstruction reveals the global and robust pattern of solar variability in the past.
Effect of a Short-term Fast on Ketamine–Xylazine Anesthesia in Rats
Struck, Maggie B; Andrutis, Karl A; Ramirez, Harvey E; Battles, August H
2011-01-01
Although ketamine–xylazine (KX) anesthesia is commonly used in rats, it is often reported to have an inconsistent anesthetic effect, with a prolonged induction time, an inadequate anesthetic plane, or a very short sleep time. Blood flow to the liver is known to shift after a meal in rats, perhaps explaining anesthetic variability among rats with variable prandial status. The current study tested the hypothesis that a short period of fasting (3 h) prior to induction with intraperitoneal KX anesthesia would provide a shorter time to recumbency, a longer total sleep time, and a more consistent loss of toe pinch response than would fed rats. Two groups of male Sprague–Dawley rats were used in blinded, crossover experiments. KX anesthesia was administered at 2 different doses (50 mg/kg–5 mg/kg and 70 mg/kg–7 mg/kg) after ad libitum feeding or a 3-h fast. There were no significant differences between groups in induction time, total sleep time, or loss of toe pinch response. We conclude that fasting rats for 3 h prior to KX intraperitoneal anesthesia does not affect induction time, total sleep time, loss of toe pinch response or reduce KX anesthetic variability in male Sprague–Dawley rats. PMID:21640029
Narcissistic rage: The Achilles’ heel of the patient with chronic physical illness
Hyphantis, Thomas; Almyroudi, Augustina; Paika, Vassiliki; Goulia, Panagiota; Arvanitakis, Konstantinos
2009-01-01
Based on the psychoanalytic reading of Homer’s Iliad whose principal theme is “Achilles’ rage” (the semi-mortal hero invulnerable in all of his body except for his heel, hence “Achilles’ heel” has come to mean a person’s principal weakness), we aimed to assess whether “narcissistic rage” has an impact on several psychosocial variables in patients with severe physical illness across time. In 878 patients with cancer, rheumatological diseases, multiple sclerosis, inflammatory bowel disease, and glaucoma, we assessed psychological distress (SCL-90 and GHQ-28), quality of life (WHOQOL-BREF), interpersonal difficulties (IIP-40), hostility (HDHQ), and defense styles (DSQ). Narcissistic rage comprised DSQ “omnipotence” and HDHQ “extraverted hostility”. Hierarchical multiple regressions analyses were performed. We showed that, in patients with disease duration less than one year, narcissistic rage had a minor impact on psychosocial variables studied, indicating that the rage was rather part of a “normal” mourning process. On the contrary, in patients with longer disease duration, increased rates of narcissistic rage had a great impact on all outcome variables, and the opposite was true for patients with low rates of narcissistic rage, indicating that narcissistic rage constitutes actually an “Achilles’ Heel” for patients with long-term physical illness. These findings may have important clinical implications. PMID:19936167
Urban heat island impacts on plant phenology: intra-urban variability and response to land cover
NASA Astrophysics Data System (ADS)
Zipper, Samuel C.; Schatz, Jason; Singh, Aditya; Kucharik, Christopher J.; Townsend, Philip A.; Loheide, Steven P., II
2016-05-01
Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is known about spatial or temporal variability in plant response to the UHI. Using an automated temperature sensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of the growing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI (USA) for the 2012-2014 growing seasons. Median urban growing season length (GSL) estimated from temperature sensors is ˜5 d longer than surrounding rural areas, and UHI impacts on GSL are relatively consistent from year-to-year. Parks within urban areas experience a subdued expression of GSL lengthening resulting from interactions between the UHI and a park cool island effect. Across all growing seasons, impervious cover in the area surrounding each temperature sensor explains >50% of observed variability in phenology. Comparisons between long-term estimates of annual mean phenological timing, derived from remote sensing, and temperature-based estimates of individual growing seasons show no relationship at the individual sensor level. The magnitude of disagreement between temperature-based and remotely sensed phenology is a function of impervious and grass cover surrounding the sensor, suggesting that realized GSL is controlled by both local land cover and micrometeorological conditions.
NASA Technical Reports Server (NTRS)
Adler, R. F.; Gu, G.; Curtis, S.; Huffman, G. J.; Bolvin, D. T.; Nelkin, E. J.
2005-01-01
The Global Precipitation Climatology Project (GPCP) 25-year precipitation data set is used to evaluate the variability and extremes on global and regional scales. The variability of precipitation year-to-year is evaluated in relation to the overall lack of a significant global trend and to climate events such as ENSO and volcanic eruptions. The validity of conclusions and limitations of the data set are checked by comparison with independent data sets (e.g., TRMM). The GPCP data set necessarily has a heterogeneous time series of input data sources, so part of the assessment described above is to test the initial results for potential influence by major data boundaries in the record. Regional trends, or inter-decadal changes, are also analyzed to determine validity and correlation with other long-term data sets related to the hydrological cycle (e.g., clouds and ocean surface fluxes). Statistics of extremes (both wet and dry) are analyzed at the monthly time scale for the 25 years. A preliminary result of increasing frequency of extreme monthly values will be a focus to determine validity. Daily values for an eight-year are also examined for variation in extremes and compared to the longer monthly-based study.
NASA Technical Reports Server (NTRS)
Bolle, H.-J.; Koslowsky, D.; Menenti, M.; Nerry, F.; Otterman, Joseph; Starr, D.
1998-01-01
Extensive areas in the Mediterranean region are subject to land degradation and desertification. The high variability of the coupling between the surface and the atmosphere affects the regional climate. Relevant surface characteristics, such as spectral reflectance, surface emissivity in the thermal-infrared region, and vegetation indices, serve as "primary" level indicators for the state of the surface. Their spatial, seasonal and interannual variability can be monitored from satellites. Using relationships between these primary data and combining them with prior information about the land surfaces (such as topography, dominant soil type, land use, collateral ground measurements and models), a second layer of information is built up which specifies the land surfaces as a component of the regional climate system. To this category of parameters which are directly involved in the exchange of energy, momentum and mass between the surface and the atmosphere, belong broadband albedo, thermodynamic surface temperature, vegetation types, vegetation cover density, soil top moisture, and soil heat flux. Information about these parameters finally leads to the computation of sensible and latent heat fluxes. The methodology was tested with pilot data sets. Full resolution, properly calibrated and normalized NOAA-AVHRR multi-annual primary data sets are presently compiled for the whole Mediterranean area, to study interannual variability and longer term trends.
Grassland responses to increased rainfall depend on the timescale of forcing.
Sullivan, Martin J P; Thomsen, Meredith A; Suttle, K B
2016-04-01
Forecasting impacts of future climate change is an important challenge to biologists, both for understanding the consequences of different emissions trajectories and for developing adaptation measures that will minimize biodiversity loss. Existing variation provides a window into the effects of climate on species and ecosystems, but in many places does not encompass the levels or timeframes of forcing expected under directional climatic change. Experiments help us to fill in these uncertainties, simulating directional shifts to examine outcomes of new levels and sustained changes in conditions. Here, we explore the translation between short-term responses to climate variability and longer-term trajectories that emerge under directional climatic change. In a decade-long experiment, we compare effects of short-term and long-term forcings across three trophic levels in grassland plots subjected to natural and experimental variation in precipitation. For some biological responses (plant productivity), responses to long-term extension of the rainy season were consistent with short-term responses, while for others (plant species richness, abundance of invertebrate herbivores and predators), there was pronounced divergence of long-term trajectories from short-term responses. These differences between biological responses mean that sustained directional changes in climate can restructure ecological relationships characterizing a system. Importantly, a positive relationship between plant diversity and productivity turned negative under one scenario of climate change, with a similar change in the relationship between plant productivity and consumer biomass. Inferences from experiments such as this form an important part of wider efforts to understand the complexities of climate change responses. © 2016 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Hotchkiss, E. R.; Ziegler, S. E.; Edwards, K. A.; Bowering, K.
2017-12-01
Water acts as a control on the cycling of organic carbon (OC). Forest productivity responses to climate change are linked to water availability while water residence time is a major control on OC loss in aquatic ecosystems. However, controls on the export of terrestrial OC to the aquatic environment remains poorly understood. Transport of dissolved OC (DOC) through soils both vertically to deeper soil horizons and into aquatic systems is a key flux of terrestrial OC, but the climate drivers controlling OC mobilized from soils is poorly understood. We installed zero-tension lysimeters across similar balsam fir forest sites within three regions that span a MAT gradient of 5.2˚C and MAP of 1050-1500 mm. Using soil water collected over all seasons for four years we tested whether a warmer and wetter climate promotes greater DOC fluxes in ecosystems experiencing relatively high precipitation. Variability within and between years was compared to that observed across climates to test the sensitivity of this flux to shorter relative to longer-term climate effects on this flux. The warmest and wettest southern site exhibited the greatest annual DOC flux (25 to 28 g C m-2 y-1) in contrast to the most northern site (8 to 10 g C m -2 y-1). This flux represented 10% of litterfall C inputs across sites and surpassed the DOC export from associated forested headwater streams (1 to 16 g C m-2 y-1) suggesting terrestrial to aquatic interface processing. Historical climate and increased soil C inputs explain the greater DOC flux in the southern region. Even in years with comparable annual precipitation among regions the DOC flux differed by climate region. Furthermore, neither quantity nor form of precipitation could explain inter-annual differences in DOC flux within each region. Region specific relationships between precipitation and soil water flux instead suggest historical climate effects may impact soil water transport efficiency thereby controlling the regional variation in the DOC flux. As these forests are exposed to a warmer and wetter climate, DOC transport from organic soils will likely increase. Although precipitation changes will impact this C flux, longer-term climate effects impacting soil inputs, composition and structure of these forests will play an important role in controlling DOC transport in a warmer and wetter future.
An Expanded Rossi X-Ray Timing Explorer Survey of X-Ray Variability in Seyfert 1 Galaxies
NASA Astrophysics Data System (ADS)
Markowitz, A.; Edelson, R.
2004-12-01
The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogeneous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from ~1 day to ~3.5 yr. The 2-10 keV variability on timescales of ~1 day, as probed by ASCA, is included. All sources exhibit stronger X-ray variability toward longer timescales, but the increase is greater for relatively higher luminosity sources. Variability amplitudes are anticorrelated with X-ray luminosity and black hole mass, but amplitudes saturate and become independent of luminosity or black hole mass toward the longest timescales. The data are consistent with the models of power spectral density (PSD) movement described by Markowitz and coworkers and McHardy and coworkers, whereby Seyfert 1 galaxies' variability can be described by a single, universal PSD shape whose break frequency scales with black hole mass. The best-fitting scaling relations between variability timescale, black hole mass, and X-ray luminosity imply an average accretion rate of ~5% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all timescales. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.
Elkin, Ché; Giuggiola, Arnaud; Rigling, Andreas; Bugmann, Harald
2015-06-01
In many regions of the world, drought is projected to increase under climate change, with potential negative consequences for forests and their ecosystem services (ES). Forest thinning has been proposed as a method for at least temporarily mitigating drought impacts, but its general applicability and longer-term impacts are unclear. We use a process-based forest model to upscale experimental data for evaluating the impacts of forest thinning in a drought-susceptible valley in the interior of the European Alps, with the specific aim of assessing (1) when and where thinning may be most effective and (2) the longer-term implications for forest dynamics. Simulations indicate that forests will be impacted by climate-induced increases in drought across a broad elevation range. At lower elevations, where drought is currently prevalent, thinning is projected to temporarily reduce tree mortality, but to have minor impacts on forest dynamics in the longer term. Thinning may be particularly useful at intermediate and higher elevations as a means of temporarily reducing mortality in drought-sensitive species such as Norway spruce and larch, which currently dominate these elevations. However, in the longer term, even intense thinning will likely not be sufficient to prevent a climate change induced dieback of these species, which is projected to occur under even moderate climate change. Thinning is also projected to have the largest impact on long-term forest dynamics at intermediate elevations, with the magnitude of the impact depending on the timing and intensity of thinning. More intense thinning that is done later is projected to more strongly promote a transition to more drought-tolerant species. We conclude that thinning is a viable option for temporarily reducing the negative drought impacts on forests, but that efficient implementation of thinning should be contingent on a site-specific evaluation of the near term risk of significant drought, and how thinning will impact the rate and direction of climate driven forest conversion.
Association between obesity and ECG variables in children and adolescents: A cross-sectional study.
Sun, Guo-Zhe; Li, Yang; Zhou, Xing-Hu; Guo, Xiao-Fan; Zhang, Xin-Gang; Zheng, Li-Qiang; Li, Yuan; Jiao, Yun-DI; Sun, Ying-Xian
2013-12-01
Obesity exhibits a wide variety of electrocardiogram (ECG) abnormalities in adults, which often lead to cardiovascular events. However, there is currently no evidence of an association between obesity and ECG variables in children and adolescents. The present study aimed to explore the associations between obesity and ECG intervals and axes in children and adolescents. A cross-sectional observational study of 5,556 students aged 5-18 years was performed. Anthropometric data, blood pressure and standard 12-lead ECGs were collected for each participant. ECG variables were measured manually based on the temporal alignment of simultaneous 12 leads using a CV200 ECG Work Station. Overweight and obese groups demonstrated significantly longer PR intervals, wider QRS durations and leftward shifts of frontal P-wave, QRS and T-wave axes, while the obese group also demonstrated significantly higher heart rates, compared with normal weight groups within normotensive or hypertensive subjects (P<0.05). Abdominal obesity was also associated with longer PR intervals, wider QRS duration and a leftward shift of frontal ECG axes compared with normal waist circumference (WC) within normotensive or hypertensive subjects (P<0.05). Gender was a possible factor affecting the ECG variables. Furthermore, the ECG variables, including PR interval, QRS duration and frontal P-wave, QRS and T-wave axes, were significantly linearly correlated with body mass index, WC and waist-to-height ratio adjusted for age, gender, ethnicity and blood pressure. However, there was no significant association between obesity and the corrected QT interval (P>0.05). The results of the current study indicate that in children and adolescents, general and abdominal obesity is associated with longer PR intervals, wider QRS duration and a leftward shift of frontal P-wave, QRS and T-wave axes, independent of age, gender, ethnicity and blood pressure.
Use of Prolonged Travel to Improve Pediatric Risk-Adjustment Models
Lorch, Scott A; Silber, Jeffrey H; Even-Shoshan, Orit; Millman, Andrea
2009-01-01
Objective To determine whether travel variables could explain previously reported differences in lengths of stay (LOS), readmission, or death at children's hospitals versus other hospital types. Data Source Hospital discharge data from Pennsylvania between 1996 and 1998. Study Design A population cohort of children aged 1–17 years with one of 19 common pediatric conditions was created (N=51,855). Regression models were constructed to determine difference for LOS, readmission, or death between children's hospitals and other types of hospitals after including five types of additional illness severity variables to a traditional risk-adjustment model. Principal Findings With the traditional risk-adjustment model, children traveling longer to children's or rural hospitals had longer adjusted LOS and higher readmission rates. Inclusion of either a geocoded travel time variable or a nongeocoded travel distance variable provided the largest reduction in adjusted LOS, adjusted readmission rates, and adjusted mortality rates for children's hospitals and rural hospitals compared with other types of hospitals. Conclusions Adding a travel variable to traditional severity adjustment models may improve the assessment of an individual hospital's pediatric care by reducing systematic differences between different types of hospitals. PMID:19207591
Focusing on Short-Term Achievement Gains Fails to Produce Long-Term Gains
ERIC Educational Resources Information Center
Grissmer, David W.; Ober, David R.; Beekman, John A.
2014-01-01
The short-term emphasis engendered by No Child Left Behind (NCLB) has focused research predominantly on unraveling the complexities and uncertainties in assessing short-term results, rather than developing methods and assessing results over the longer term. In this paper we focus on estimating long-term gains and address questions important to…
NASA Astrophysics Data System (ADS)
Rhee, Jinyoung; Kim, Gayoung; Im, Jungho
2017-04-01
Three regions of Indonesia with different rainfall characteristics were chosen to develop drought forecast models based on machine learning. The 6-month Standardized Precipitation Index (SPI6) was selected as the target variable. The models' forecast skill was compared to the skill of long-range climate forecast models in terms of drought accuracy and regression mean absolute error (MAE). Indonesian droughts are known to be related to El Nino Southern Oscillation (ENSO) variability despite of regional differences as well as monsoon, local sea surface temperature (SST), other large-scale atmosphere-ocean interactions such as Indian Ocean Dipole (IOD) and Southern Pacific Convergence Zone (SPCZ), and local factors including topography and elevation. Machine learning models are thus to enhance drought forecast skill by combining local and remote SST and remote sensing information reflecting initial drought conditions to the long-range climate forecast model results. A total of 126 machine learning models were developed for the three regions of West Java (JB), West Sumatra (SB), and Gorontalo (GO) and six long-range climate forecast models of MSC_CanCM3, MSC_CanCM4, NCEP, NASA, PNU, POAMA as well as one climatology model based on remote sensing precipitation data, and 1 to 6-month lead times. When compared the results between the machine learning models and the long-range climate forecast models, West Java and Gorontalo regions showed similar characteristics in terms of drought accuracy. Drought accuracy of the long-range climate forecast models were generally higher than the machine learning models with short lead times but the opposite appeared for longer lead times. For West Sumatra, however, the machine learning models and the long-range climate forecast models showed similar drought accuracy. The machine learning models showed smaller regression errors for all three regions especially with longer lead times. Among the three regions, the machine learning models developed for Gorontalo showed the highest drought accuracy and the lowest regression error. West Java showed higher drought accuracy compared to West Sumatra, while West Sumatra showed lower regression error compared to West Java. The lower error in West Sumatra may be because of the smaller sample size used for training and evaluation for the region. Regional differences of forecast skill are determined by the effect of ENSO and the following forecast skill of the long-range climate forecast models. While shown somewhat high in West Sumatra, relative importance of remote sensing variables was mostly low in most cases. High importance of the variables based on long-range climate forecast models indicates that the forecast skill of the machine learning models are mostly determined by the forecast skill of the climate models.
Long-Term In Vitro Degradation of a High-Strength Brushite Cement in Water, PBS, and Serum Solution
Ajaxon, Ingrid; Öhman, Caroline; Persson, Cecilia
2015-01-01
Bone loss and fractures may call for the use of bone substituting materials, such as calcium phosphate cements (CPCs). CPCs can be degradable, and, to determine their limitations in terms of applications, their mechanical as well as chemical properties need to be evaluated over longer periods of time, under physiological conditions. However, there is lack of data on how the in vitro degradation affects high-strength brushite CPCs over longer periods of time, that is, longer than it takes for a bone fracture to heal. This study aimed at evaluating the long-term in vitro degradation properties of a high-strength brushite CPC in three different solutions: water, phosphate buffered saline, and a serum solution. Microcomputed tomography was used to evaluate the degradation nondestructively, complemented with gravimetric analysis. The compressive strength, chemical composition, and microstructure were also evaluated. Major changes from 10 weeks onwards were seen, in terms of formation of a porous outer layer of octacalcium phosphate on the specimens with a concomitant change in phase composition, increased porosity, decrease in object volume, and mechanical properties. This study illustrates the importance of long-term evaluation of similar cement compositions to be able to predict the material's physical changes over a relevant time frame. PMID:26587540
Karyotaki, Eirini; Smit, Yolba; de Beurs, Derek P; Henningsen, Kirsten Holdt; Robays, Jo; Huibers, Marcus J H; Weitz, Erica; Cuijpers, Pim
2016-05-01
Understanding the effectiveness of treatment for depression in both the short term and long term is essential for clinical decision making. The present meta-analysis examined treatment effects on depression and quality of life in acute-phase psychotherapeutic interventions compared to no treatment control groups for adult depression at 6 months or longer postrandomization. A systematic literature search resulted in 44 randomized controlled trials with 6,096 participants. Acute-phase psychotherapy was compared to control groups at 6-month or longer postrandomization. Odds ratios of a positive outcome were calculated. Psychotherapy outperformed control groups at 6 months or longer postrandomization (OR = 1.92, 95% CI: 1.60-2.31, P < .001). Heterogeneity was moderate (I²: 65, 95% CI: 53-74, P < .001). However, effects significantly decreased with longer follow-up periods. Additionally, a small positive effect of psychotherapy was observed for quality of life, while similar effects were obtained in separate analyses of each type of psychotherapy, with the exception of nondirective supportive therapy. Studies that provided booster sessions had better treatment results compared with studies that did not provide any further sessions. Finally, we found that trials on psychotherapy aimed at major depressive disorder (MDD) had better outcomes than those that were aimed at elevated depressive symptoms. There is substantial evidence that acute-phase psychotherapy results in a better treatment effects on depression and quality of life in the long term for adult patients with depression. © 2016 Wiley Periodicals, Inc.
Harris, M.S.; Gayes, P.T.; Kindinger, J.L.; Flocks, J.G.; Krantz, D.E.; Donovan, P.
2005-01-01
Coastal landscapes evolve over wide-ranging spatial and temporal scales in response to physical and biological pro-cesses that interact with a wide range of variables. To develop better predictive models for these dynamic areas, we must understand the influence of these variables on coastal morphologies and ultimately how they influence coastal processes. This study defines the influence of geologic framework variability on a classic mixed-energy coastline, and establishes four categorical scales of spatial and temporal influence on the coastal system. The near-surface, geologic framework was delineated using high-resolution seismic profiles, shallow vibracores, detailed geomorphic maps, historical shorelines, aerial photographs, and existing studies, and compared to the long- and short-term development of two coastal compartments near Charleston, South Carolina. Although it is clear that the imprint of a mixed-energy tidal and wave signal (basin-scale) dictates formation of drumstick barriers and that immediate responses to wave climate are dramatic, island size, position, and longer-term dynamics are influenced by a series of inherent, complex near-surface stratigraphic geometries. Major near-surface Tertiary geometries influence inlet placement and drainage development (island-scale) through multiple interglacial cycles and overall channel morphology (local-scale). During the modern marine transgression, the halo of ebb-tidal deltas greatly influence inlet region dynamics, while truncated beach ridges and exposed, differentially erodable Cenozoic deposits in the active system influence historical shoreline dynamics and active shoreface morphologies (blockscale). This study concludes that the mixed-energy imprint of wave and tide theories dominates general coastal morphology, but that underlying stratigraphic influences on the coast provide site-specific, long-standing imprints on coastal evolution.
NASA Astrophysics Data System (ADS)
Maurer, E. P.; Stewart, I. T.; Sundstrom, W.; Bacon, C. M.
2016-12-01
In addition to periodic long-term drought, much of Central America experiences a rainy season with two peaks separated by a dry period of weeks to over a month in duration, termed the mid-summer drought (MSD). Food and water security for smallholder farmers in the region hinge on accommodating this phenomenon, anticipating its arrival and estimating its duration. Model output from 1980 through the late 21st century projects changes in precipitation amount, variability, and timing, with potential to affect regional food production. Using surveys of farmer experiences in conjunction with gridded daily precipitation for a historic period on multiple scales, and with projections through the 21st century, we characterize the MSD across much of Central America using four measures: onset date, duration, intensity, and minimum, and test for significant changes. Our findings indicate that the most significant changes are for the duration, which, by the end of the century, is projected to increase by an average of over a week, and the MSD minimum precipitation, which is projected to decline by an average of over 26%, with statistically significant changes for most of Nicaragua, Honduras, El Salvador, and Guatemala (assuming a higher emissions pathway through the 21st century). These changes toward a longer and drier MSD have important implications for food and water security for vulnerable communities through the region. We find that for the four metrics the changes in interannual variability are small compared to historical variability, and are generally statistically insignificant. New farmer survey results are compared to findings from our climate analysis for the historic period, are used to interpret what MSD characteristics are of greatest interest locally, and are used for the development of adaptation strategies.
Long-Term and Seasonal Dynamics of Dengue in Iquitos, Peru
Stoddard, Steven T.; Wearing, Helen J.; Reiner, Robert C.; Morrison, Amy C.; Astete, Helvio; Vilcarromero, Stalin; Alvarez, Carlos; Ramal-Asayag, Cesar; Sihuincha, Moises; Rocha, Claudio; Halsey, Eric S.; Scott, Thomas W.; Kochel, Tadeusz J.; Forshey, Brett M.
2014-01-01
Introduction Long-term disease surveillance data provide a basis for studying drivers of pathogen transmission dynamics. Dengue is a mosquito-borne disease caused by four distinct, but related, viruses (DENV-1-4) that potentially affect over half the world's population. Dengue incidence varies seasonally and on longer time scales, presumably driven by the interaction of climate and host susceptibility. Precise understanding of dengue dynamics is constrained, however, by the relative paucity of laboratory-confirmed longitudinal data. Methods We studied 10 years (2000–2010) of laboratory-confirmed, clinic-based surveillance data collected in Iquitos, Peru. We characterized inter and intra-annual patterns of dengue dynamics on a weekly time scale using wavelet analysis. We explored the relationships of case counts to climatic variables with cross-correlation maps on annual and trimester bases. Findings Transmission was dominated by single serotypes, first DENV-3 (2001–2007) then DENV-4 (2008–2010). After 2003, incidence fluctuated inter-annually with outbreaks usually occurring between October and April. We detected a strong positive autocorrelation in case counts at a lag of ∼70 weeks, indicating a shift in the timing of peak incidence year-to-year. All climatic variables showed modest seasonality and correlated weakly with the number of reported dengue cases across a range of time lags. Cases were reduced after citywide insecticide fumigation if conducted early in the transmission season. Conclusions Dengue case counts peaked seasonally despite limited intra-annual variation in climate conditions. Contrary to expectations for this mosquito-borne disease, no climatic variable considered exhibited a strong relationship with transmission. Vector control operations did, however, appear to have a significant impact on transmission some years. Our results indicate that a complicated interplay of factors underlie DENV transmission in contexts such as Iquitos. PMID:25033412
NASA Astrophysics Data System (ADS)
Burns, R. G.; Meyer, R. W.; Cornwell, K.
2003-12-01
In-basin statistical relations allow for development of regional flood frequency and magnitude equations in the Cosumnes River and Mokelumne River drainage basins. Current equations were derived from data collected through 1975, and do not reflect newer data with some significant flooding. Physical basin characteristics (area, mean basin elevation, slope of longest reach, and mean annual precipitation) were correlated against predicted flood discharges for each of the 5, 10, 25, 50, 100, 200, and 500-year recurrence intervals in a multivariate analysis. Predicted maximum instantaneous flood discharges were determined using the PEAKFQ program with default settings, for 24 stream gages within the study area presumed not affected by flow management practices. For numerical comparisons, GIS-based methods using Spatial Analyst and the Arc Hydro Tools extension were applied to derive physical basin characteristics as predictor variables from a 30m digital elevation model (DEM) and a mean annual precipitation raster (PRISM). In a bivariate analysis, examination of Pearson correlation coefficients, F-statistic, and t & p thresholds show good correlation between area and flood discharges. Similar analyses show poor correlation for mean basin elevation, slope and precipitation, with flood discharge. Bivariate analysis suggests slope may not be an appropriate predictor term for use in the multivariate analysis. Precipitation and elevation correlate very well, demonstrating possible orographic effects. From the multivariate analysis, less than 6% of the variability in the correlation is not explained for flood recurrences up to 25 years. Longer term predictions up to 500 years accrue greater uncertainty with as much as 15% of the variability in the correlation left unexplained.
Ice_Sheets_CCI: Essential Climate Variables for the Greenland Ice Sheet
NASA Astrophysics Data System (ADS)
Forsberg, R.; Sørensen, L. S.; Khan, A.; Aas, C.; Evansberget, D.; Adalsteinsdottir, G.; Mottram, R.; Andersen, S. B.; Ahlstrøm, A.; Dall, J.; Kusk, A.; Merryman, J.; Hvidberg, C.; Khvorostovsky, K.; Nagler, T.; Rott, H.; Scharrer, M.; Shepard, A.; Ticconi, F.; Engdahl, M.
2012-04-01
As part of the ESA Climate Change Initiative (www.esa-cci.org) a long-term project "ice_sheets_cci" started January 1, 2012, in addition to the existing 11 projects already generating Essential Climate Variables (ECV) for the Global Climate Observing System (GCOS). The "ice_sheets_cci" goal is to generate a consistent, long-term and timely set of key climate parameters for the Greenland ice sheet, to maximize the impact of European satellite data on climate research, from missions such as ERS, Envisat and the future Sentinel satellites. The climate parameters to be provided, at first in a research context, and in the longer perspective by a routine production system, would be grids of Greenland ice sheet elevation changes from radar altimetry, ice velocity from repeat-pass SAR data, as well as time series of marine-terminating glacier calving front locations and grounding lines for floating-front glaciers. The ice_sheets_cci project will involve a broad interaction of the relevant cryosphere and climate communities, first through user consultations and specifications, and later in 2012 optional participation in "best" algorithm selection activities, where prototype climate parameter variables for selected regions and time frames will be produced and validated using an objective set of criteria ("Round-Robin intercomparison"). This comparative algorithm selection activity will be completely open, and we invite all interested scientific groups with relevant experience to participate. The results of the "Round Robin" exercise will form the algorithmic basis for the future ECV production system. First prototype results will be generated and validated by early 2014. The poster will show the planned outline of the project and some early prototype results.
Spieth, Peter M; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo
2014-05-02
General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary function and reduces systemic inflammatory response. However, it is currently not known whether patients undergoing open abdominal surgery might benefit from intraoperative variable ventilation. The PROtective VARiable ventilation trial ('PROVAR') is a single center, randomized controlled trial enrolling 50 patients who are planning for open abdominal surgery expected to last longer than 3 hours. PROVAR compares conventional (non-variable) lung protective ventilation (CV) with variable lung protective ventilation (VV) regarding pulmonary function and inflammatory response. The primary endpoint of the study is the forced vital capacity on the first postoperative day. Secondary endpoints include further lung function tests, plasma cytokine levels, spatial distribution of ventilation assessed by means of electrical impedance tomography and postoperative pulmonary complications. We hypothesize that VV improves lung function and reduces systemic inflammatory response compared to CV in patients receiving mechanical ventilation during general anesthesia for open abdominal surgery longer than 3 hours. PROVAR is the first randomized controlled trial aiming at intra- and postoperative effects of VV on lung function. This study may help to define the role of VV during general anesthesia requiring mechanical ventilation. Clinicaltrials.gov NCT01683578 (registered on September 3 3012).
Marcilio, Izabel; Hajat, Shakoor; Gouveia, Nelson
2013-08-01
This study aimed to develop different models to forecast the daily number of patients seeking emergency department (ED) care in a general hospital according to calendar variables and ambient temperature readings and to compare the models in terms of forecasting accuracy. The authors developed and tested six different models of ED patient visits using total daily counts of patient visits to an ED in Sao Paulo, Brazil, from January 1, 2008, to December 31, 2010. The first 33 months of the data set were used to develop the ED patient visits forecasting models (the training set), leaving the last 3 months to measure each model's forecasting accuracy by the mean absolute percentage error (MAPE). Forecasting models were developed using three different time-series analysis methods: generalized linear models (GLM), generalized estimating equations (GEE), and seasonal autoregressive integrated moving average (SARIMA). For each method, models were explored with and without the effect of mean daily temperature as a predictive variable. The daily mean number of ED visits was 389, ranging from 166 to 613. Data showed a weekly seasonal distribution, with highest patient volumes on Mondays and lowest patient volumes on weekends. There was little variation in daily visits by month. GLM and GEE models showed better forecasting accuracy than SARIMA models. For instance, the MAPEs from GLM models and GEE models at the first month of forecasting (October 2012) were 11.5 and 10.8% (models with and without control for the temperature effect, respectively), while the MAPEs from SARIMA models were 12.8 and 11.7%. For all models, controlling for the effect of temperature resulted in worse or similar forecasting ability than models with calendar variables alone, and forecasting accuracy was better for the short-term horizon (7 days in advance) than for the longer term (30 days in advance). This study indicates that time-series models can be developed to provide forecasts of daily ED patient visits, and forecasting ability was dependent on the type of model employed and the length of the time horizon being predicted. In this setting, GLM and GEE models showed better accuracy than SARIMA models. Including information about ambient temperature in the models did not improve forecasting accuracy. Forecasting models based on calendar variables alone did in general detect patterns of daily variability in ED volume and thus could be used for developing an automated system for better planning of personnel resources. © 2013 by the Society for Academic Emergency Medicine.
Tentori, Francesca; Zhang, Jinyao; Li, Yun; Karaboyas, Angelo; Kerr, Peter; Saran, Rajiv; Bommer, Juergen; Port, Friedrich; Akiba, Takashi; Pisoni, Ronald; Robinson, Bruce
2012-01-01
Background Longer dialysis session length (treatment time, TT) has been associated with better survival among hemodialysis (HD) patients. The impact of TT on clinical markers that may contribute to this survival advantage is not well known. Methods Using data from the international Dialysis Outcomes and Practice Patterns Study, we assessed the association of TT with clinical outcomes using both standard regression analyses and instrumental variable approaches. The study included 37 414 patients on in-center HD three times per week with prescribed TT from 120 to 420 min. Results Facility mean TT ranged from 214 min in the USA to 256 min in Australia–New Zealand. Accounting for country effects, mortality risk was lower for patients with longer TT {hazard ratio for every 30 min: all-cause mortality: 0.94 [95% confidence interval (CI): 0.92–0.97], cardiovascular mortality: 0.95 (95% CI: 0.91–0.98) and sudden death: 0.93 (95% CI: 0.88–0.98)}. Patients with longer TT had lower pre- and post-dialysis systolic blood pressure, greater intradialytic weight loss, higher hemoglobin (for the same erythropoietin dose), serum albumin and potassium and lower serum phosphorus and white blood cell counts. Similar associations were found using the instrumental variable approach, although the positive associations of TT with weight loss and potassium were lost. Conclusions Favorable levels of a variety of clinical markers may contribute to the better survival of patients receiving longer TT. These findings support longer TT prescription in the setting of in-center, three times per week HD. PMID:22431708
Sarma, Sisira; Hajizadeh, Mohammad; Thind, Amardeep; Chan, Rick
2013-01-01
Objective: To describe the association between health information technology (HIT) adoption and family physicians' patient visit length in Canada after controlling for physician and practice characteristics. Method: HIT adoption is defined in terms of four types of HIT usage: no HIT use (NO), basic HIT use without electronic medical record system (HIT), basic HIT use with electronic medical record (EMR) and advanced HIT use (EMR + HIT). The outcome variable is the average time spent on a patient visit (visit length). The data for this study came from the 2007 and 2010 National Physician Surveys. A log-linear model was used to analyze our visit length outcome. Results: The average time worked per week was found to be in the neighbourhood of 36 hours in both 2007 and 2010, but users of EMR and EMR + HIT were undertaking fewer patient visits per week relative to NO users. Multivariable analysis showed that EMR and EMR + HIT were associated with longer average time spent per patient visit by about 7.7% (p<0.05) and 6.7% (p<0.01), respectively, compared to NO users in 2007. In 2010, EMR was not statistically significant and EMR + HIT was associated with a 4% (p<0.1) increased visit length. A variety of practice-related variables such as the mode of remuneration, work setting and interprofessional practice influenced visit length in the expected direction. Conclusion: Use of HIT is found to be associated with fewer patient visits and longer visit length among family physicians in Canada relative to NO users, but this association weakened in the multivariable analysis of 2010. PMID:23968677
NASA Astrophysics Data System (ADS)
Allen, C. D.
2006-12-01
In 1993 long-term research began on the runoff and erosion dynamics of a pinyon-juniper woodland hillslope at Bandelier National Monument in northern New Mexico (USA). In the 1.09 ha Frijolito watershed, erosion has been continuously studied at 3 spatial scales: 1 square meter, about 1000 square meters, and the entire watershed. This site is currently representative of degraded woodlands of pinyon (Pinus edulis) and one-seed juniper (Juniperus monosperma) in this region, exhibiting marked connectivity of exposed bare soil interspaces between tree canopy patches and obvious geomorphic signs of accelerated soil erosion (e.g., pedestalling, actively expanding rill networks). Ecological and land use histories show that this site has undergone a number of dramatic ecohydrological shifts since ca. C.E. 1850, transitioning from: 1) open ponderosa pine (Pinus ponderosa) overstory with limited pinyon-juniper component and substantial herbaceous understory that supported surface fires and constrained soil erosion, to; 2) ponderosa pine with reduced herbaceous cover due to livestock grazing after ca.1870, resulting in collapse of the surface fire regime and increased establishment of young pinyon and juniper trees, to; 3) mortality of all of the ponderosa pine during the extreme drought of the 1950s, leaving eroding pinyon-juniper woodland, to; 4) mortality of all mature pinyon at or above sapling size during the 2002-2003 drought, with juniper now the only dominant woody species. Detailed measurements since 1993 document high rates of soil erosion (> 2.75 Mg/ha/year on average at the watershed scale) that are rapidly stripping the local soils. Long-term observations are needed to distinguish short-term variability from longer term trends, as measurements of runoff and erosion show extreme variability at multiple time scales since 1993. The multi-scale erosion data from the Frijolito watershed reveal little dropoff in erosion rate (g/meter-squared) between the one meter-square scale and the 1.09 ha scale, in sharp contrast to the expected pattern observed at a nearby (7 km) relatively stable woodland watershed (cf. Wilcox et al. 2003). These results have important implications for modeling of soil erosion, highlighting the importance of including long-term field data and ecohydrological factors, particularly spatial patterns of canopy and intercanopy surface cover that are key determinants of scale-dependent erosion rates.
Seasonal associations of climatic drivers and malaria in the highlands of Ethiopia.
Midekisa, Alemayehu; Beyene, Belay; Mihretie, Abere; Bayabil, Estifanos; Wimberly, Michael C
2015-06-24
The impacts of interannual climate fluctuations on vector-borne diseases, especially malaria, have received considerable attention in the scientific literature. These effects can be significant in semi-arid and high-elevation areas such as the highlands of East Africa because cooler temperature and seasonally dry conditions limit malaria transmission. Many previous studies have examined short-term lagged effects of climate on malaria (weeks to months), but fewer have explored the possibility of longer-term seasonal effects. This study assessed the interannual variability of malaria occurrence from 2001 to 2009 in the Amhara region of Ethiopia. We tested for associations of climate variables summarized during the dry (January-April), early transition (May-June), and wet (July-September) seasons with malaria incidence in the early peak (May-July) and late peak (September-December) epidemic seasons using generalized linear models. Climate variables included land surface temperature (LST), rainfall, actual evapotranspiration (ET), and the enhanced vegetation index (EVI). We found that both early and late peak malaria incidence had the strongest associations with meteorological conditions in the preceding dry and early transition seasons. Temperature had the strongest influence in the wetter western districts, whereas moisture variables had the strongest influence in the drier eastern districts. We also found a significant correlation between malaria incidence in the early and the subsquent late peak malaria seasons, and the addition of early peak malaria incidence as a predictor substantially improved models of late peak season malaria in both of the study sub-regions. These findings suggest that climatic effects on malaria prior to the main rainy season can carry over through the rainy season and affect the probability of malaria epidemics during the late malaria peak. The results also emphasize the value of combining environmental monitoring with epidemiological surveillance to develop forecasts of malaria outbreaks, as well as the need for spatially stratified approaches that reflect the differential effects of climatic variations in the different sub-regions.
NASA Astrophysics Data System (ADS)
Elliott, David
2017-07-01
As renewable energy use expands there will be a need to develop ways to balance its variability. Storage is one of the options. Presently the main emphasis is for systems storing electrical power in advanced batteries (many of them derivatives of parallel developments in the electric vehicle field), as well as via liquid air storage, compressed air storage, super-capacitors and flywheels, and, the leader so far, pumped hydro reservoirs. In addition, new systems are emerging for hydrogen generation and storage, feeding fuel cell power production. Heat (and cold) is also a storage medium and some systems exploit thermal effects as part of wider energy management activity. Some of the more exotic ones even try to use gravity on a large scale. This short book looks at all the options, their potentials and their limits. There are no clear winners, with some being suited to short-term balancing and others to longer-term storage. The eventual mix adopted will be shaped by the pattern of development of other balancing measures, including smart-grid demand management and super-grid imports and exports.
Ambrosini, Roberto; Cuervo, José Javier; du Feu, Chris; Fiedler, Wolfgang; Musitelli, Federica; Rubolini, Diego; Sicurella, Beatrice; Spina, Fernando; Saino, Nicola; Møller, Anders Pape
2016-05-01
Many partially migratory species show phenotypically divergent populations in terms of migratory behaviour, with climate hypothesized to be a major driver of such variability through its differential effects on sedentary and migratory individuals. Based on long-term (1947-2011) bird ringing data, we analysed phenotypic differentiation of migratory behaviour among populations of the European robin Erithacus rubecula across Europe. We showed that clusters of populations sharing breeding and wintering ranges varied from partial (British Isles and Western Europe, NW cluster) to completely migratory (Scandinavia and north-eastern Europe, NE cluster). Distance migrated by birds of the NE (but not of the NW) cluster decreased through time because of a north-eastwards shift in the wintering grounds. Moreover, when winter temperatures in the breeding areas were cold, individuals from the NE cluster also migrated longer distances, while those of the NW cluster moved over shorter distances. Climatic conditions may therefore affect migratory behaviour of robins, although large geographical variation in response to climate seems to exist. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.
Long-term change in the megabenthos of the Porcupine Abyssal Plain (NE Atlantic)
NASA Astrophysics Data System (ADS)
Billett, D. S. M.; Bett, B. J.; Rice, A. L.; Thurston, M. H.; Galéron, J.; Sibuet, M.; Wolff, G. A.
A radical change in the abundance of invertebrate megafauna on the Porcupine Abyssal Plain is reported over a period of 10 years (1989-1999). Actiniarians, annelids, pycnogonids, tunicates, ophiuroids and holothurians increased significantly in abundance. However, there was no significant change in wet weight biomass. Two holothurian species, Amperima rosea and Ellipinion molle, increased in abundance by more than two orders of magnitude. Samples from the Porcupine Abyssal Plain over a longer period (1977-1999) show that prior to 1996 these holothurian species were always a minor component of the megafauna. From 1996 to 1999 A. rosea was abundant over a wide area of the Porcupine Abyssal Plain indicating that the phenomenon was not a localised event. Several dominant holothurian species show a distinct trend in decreasing body size over the study period. The changes in megafauna abundance may be related to environmental forcing (food supply) rather than to localised stochastic population variations. Inter-annual variability and long-term trends in organic matter supply to the seabed may be responsible for the observed changes in abundance, species dominance and size distributions.
Quantum collapse of dust shells in 2 + 1 gravity
NASA Astrophysics Data System (ADS)
Ortíz, L.; Ryan, M. P.
2007-08-01
This paper considers the quantum collapse of infinitesimally thin dust shells in 2 + 1 gravity. In 2 + 1 gravity a shell is no longer a sphere, but a ring of matter. The classical equation of motion of such shells in terms of variables defined on the shell has been considered by Peleg and Steif (Phys Rev D 51:3992, 1995), using the 2 + 1 version of the original formulation of Israel (Nuovo Cimento B 44:1, 1966), and Crisóstomo and Olea (Phys Rev D 69:104023, 2004), using canonical methods. The minisuperspace quantum problem can be reduced to that of a harmonic oscillator in terms of the curvature radius of the shell, which allows us to use well-known methods to find the motion of coherent wave packets that give the quantum collapse of the shell. Classically, as the radius of the shell falls below a certain point, a horizon forms. In the quantum problem one can define various quantities that give “indications” of horizon formation. Without a proper definition of a “horizon” in quantum gravity, these can be nothing but indications.
Early benefits of mitigation in risk of regional climate extremes
NASA Astrophysics Data System (ADS)
Ciavarella, Andrew; Stott, Peter; Lowe, Jason
2017-04-01
Large differences in climate outcomes are projected by the end of this century depending on whether greenhouse gas emissions continue to increase or are reduced sufficiently to limit total warming to below 2 °C (ref. ). However, it is generally thought that benefits of mitigation are hidden by internal climate variability until later in the century. Here we show that if the likelihood of extremely hot seasons is considered, the benefits of mitigation emerge more quickly than previously thought. It takes less than 20 years of emissions reductions in many regions for the likelihood of extreme seasonal warmth to reduce by more than half following initiation of mitigation. Additionally we show that the latest possible date at which the probability of extreme seasonal temperatures will be halved through emissions reductions consistent with the 2 °C target is in the 2040s. Exposure to climate risk is therefore reduced markedly and rapidly with substantial reductions of greenhouse gas emissions, demonstrating that the early mitigation needed to limit eventual warming below potentially dangerous levels benefits societies in the nearer term not just in the longer-term future.
Taylor-Robinson, David C; Milton, Beth; Lloyd-Williams, Ffion; O'Flaherty, Martin; Capewell, Simon
2008-01-01
Background In order to better understand factors that influence decisions for public health, we undertook a qualitative study to explore issues relating to the time horizons used in decision-making. Methods Qualitative study using semi-structured interviews. 33 individuals involved in the decision making process around coronary heart disease were purposively sampled from the UK National Health Service (national, regional and local levels), academia and voluntary organizations. Analysis was based on the framework method using N-VIVO software. Interviews were transcribed, coded and emergent themes identified. Results Many participants suggested that the timescales for public health decision-making are too short. Commissioners and some practitioners working at the national level particularly felt constrained in terms of planning for the long-term. Furthermore respondents felt that longer term planning was needed to address the wider determinants of health and to achieve societal level changes. Three prominent 'systems' issues were identified as important drivers of short term thinking: the need to demonstrate impact within the 4 year political cycle; the requirement to 'balance the books' within the annual commissioning cycle and the disruption caused by frequent re-organisations within the health service. In addition respondents suggested that the tools and evidence base for longer term planning were not well established. Conclusion Many public health decision and policy makers feel that the timescales for decision-making are too short. Substantial systemic barriers to longer-term planning exist. Policy makers need to look beyond short-term targets and budget cycles to secure investment for long-term improvement in public health. PMID:19094194
Taylor-Robinson, David C; Milton, Beth; Lloyd-Williams, Ffion; O'Flaherty, Martin; Capewell, Simon
2008-12-18
In order to better understand factors that influence decisions for public health, we undertook a qualitative study to explore issues relating to the time horizons used in decision-making. Qualitative study using semi-structured interviews. 33 individuals involved in the decision making process around coronary heart disease were purposively sampled from the UK National Health Service (national, regional and local levels), academia and voluntary organizations. Analysis was based on the framework method using N-VIVO software. Interviews were transcribed, coded and emergent themes identified. Many participants suggested that the timescales for public health decision-making are too short. Commissioners and some practitioners working at the national level particularly felt constrained in terms of planning for the long-term. Furthermore respondents felt that longer term planning was needed to address the wider determinants of health and to achieve societal level changes. Three prominent 'systems' issues were identified as important drivers of short term thinking: the need to demonstrate impact within the 4 year political cycle; the requirement to 'balance the books' within the annual commissioning cycle and the disruption caused by frequent re-organisations within the health service. In addition respondents suggested that the tools and evidence base for longer term planning were not well established. Many public health decision and policy makers feel that the timescales for decision-making are too short. Substantial systemic barriers to longer-term planning exist. Policy makers need to look beyond short-term targets and budget cycles to secure investment for long-term improvement in public health.
Łoniewska, Beata; Kaczmarczyk, Mariusz; Clark, Jeremy Simon; Gorący, Iwona; Horodnicka-Józwa, Anita; Ciechanowicz, Andrzej
2015-03-16
A-Kinase Anchoring Proteins (AKAPs) coordinate the specificity of protein kinase A signaling by localizing the kinase to subcellular sites. The 1936G (V646) AKAP10 allele has been associated in adults with low cholinergic/vagus nerve sensitivity, shortened PR intervals in ECG recording and in newborns with increased blood pressure and higher cholesterol cord blood concentration. The aim of the study was to answer the question of whether 1936A > G AKAP10 polymorphism is associated with the newborn electrocardiographic variables. Electrocardiograms were recorded from 114 consecutive healthy Polish newborns (55 females, 59 males), born after 37 gestational weeks to healthy women with uncomplicated pregnancies. All recordings were made between 3(rd) and 7(th) day of life to avoid QT variability. The heart rate per minute and duration of PR, QRS, RR and QT intervals were usually measured. The ECGs were evaluated independently by three observers. At birth, cord blood of neonates was obtained for isolation of genomic DNA. The distribution of anthropometric and electrocardiographic variables in our cohort approached normality (skewness < 2 for all variables). No significant differences in anthropometric variables and electrocardiographic traits with respect to AKAP10 genotype were found. Multiple regression analysis with adjustment for gender, gestational age and birth mass revealed that QTc interval in GG AKAP10 homozygotes was significantly longer, but in range, when compared with A alleles carriers (AA + AG, recessive mode of inheritance). No rhythm disturbances were observed. Results demonstrate possible association between AKAP10 1936A > G variant and QTc interval in Polish newborns.
Costa, Rui Miguel; Miller, Geoffrey F; Brody, Stuart
2012-12-01
Research indicates that (i) women's orgasm during penile-vaginal intercourse (PVI) is influenced by fitness-related male partner characteristics, (ii) penis size is important for many women, and (iii) preference for a longer penis is associated with greater vaginal orgasm consistency (triggered by PVI without concurrent clitoral masturbation). To test the hypothesis that vaginal orgasm frequency is associated with women's reporting that a longer than average penis is more likely to provoke their PVI orgasm. Three hundred twenty-three women reported in an online survey their past month frequency of various sexual behaviors (including PVI, vaginal orgasm, and clitoral orgasm), the effects of a longer than average penis on likelihood of orgasm from PVI, and the importance they attributed to PVI and to noncoital sex. Univariate analyses of covariance with dependent variables being frequencies of various sexual behaviors and types of orgasm and with independent variable being women reporting vs. not reporting that a longer than average penis is important for their orgasm from PVI. Likelihood of orgasm with a longer penis was related to greater vaginal orgasm frequency but unrelated to frequencies of other sexual behaviors, including clitoral orgasm. In binary logistic regression, likelihood of orgasm with a longer penis was related to greater importance attributed to PVI and lesser importance attributed to noncoital sex. Women who prefer deeper penile-vaginal stimulation are more likely to have vaginal orgasm, consistent with vaginal orgasm evolving as part of a female mate choice system favoring somewhat larger than average penises. Future research could extend the findings by overcoming limitations related to more precise measurement of penis length (to the pubis and pressed close to the pubic bone) and girth, and large representative samples. Future experimental research might assess to what extent different penis sizes influence women's satisfaction and likelihood of vaginal orgasm. © 2012 International Society for Sexual Medicine.
Lexical frequency effects on articulation: a comparison of picture naming and reading aloud
Mousikou, Petroula; Rastle, Kathleen
2015-01-01
The present study investigated whether lexical frequency, a variable that is known to affect the time taken to utter a verbal response, may also influence articulation. Pairs of words that differed in terms of their relative frequency, but were matched on their onset, vowel, and number of phonemes (e.g., map vs. mat, where the former is more frequent than the latter) were used in a picture naming and a reading aloud task. Low-frequency items yielded slower response latencies than high-frequency items in both tasks, with the frequency effect being significantly larger in picture naming compared to reading aloud. Also, initial-phoneme durations were longer for low-frequency items than for high-frequency items. The frequency effect on initial-phoneme durations was slightly more prominent in picture naming than in reading aloud, yet its size was very small, thus preventing us from concluding that lexical frequency exerts an influence on articulation. Additionally, initial-phoneme and whole-word durations were significantly longer in reading aloud compared to picture naming. We discuss our findings in the context of current theories of reading aloud and speech production, and the approaches they adopt in relation to the nature of information flow (staged vs. cascaded) between cognitive and articulatory levels of processing. PMID:26528223
Li, Hong-Jie; Zhong, Bao-Liang; Xu, Yan-Min; Zhu, Jun-Hong; Lu, Jin
2017-10-24
Given the socially isolated status of Chinese heroin-dependent patients (HDPs) and the significant association between loneliness and sleep problem in the general population, the impact of loneliness on sleep of HDPs is potentially substantial. The study aimed to test whether loneliness is associated with poor sleep in terms of quantity and quality in a consecutive sample of Chinese HDPs receiving methadone maintenance treatment (MMT). The study participants were 603 HDPs of three MMT clinics in Wuhan, China. Data on socio-demographic and clinical characteristics were collected by a standardized self-administered questionnaire. Sleep outcomes included sleep latency, sleep duration, sleep efficiency, and sleep quality. We measured depressive symptoms, loneliness, and sleep quality by using Zung's Self-rating Depression Scale, the single-item self-report of loneliness, and the Pittsburgh Sleep Quality Index, respectively. Multiple linear regression was used to examine whether loneliness is independently associated with sleep measures. After controlling for the confounding effects of potential socio-demographic and clinical variables, loneliness was significantly associated with longer sleep latency, shorter sleep duration, lower sleep efficiency, and poorer sleep quality. Loneliness may exacerbate sleep disturbance in Chinese HDPs of MMT clinics. Psychosocial interventions aimed at reducing loneliness in MMT clinics would improve the sleep of HDPs.
Tidière, Morgane; Gaillard, Jean-Michel; Berger, Vérane; Müller, Dennis W. H.; Bingaman Lackey, Laurie; Gimenez, Olivier; Clauss, Marcus; Lemaître, Jean-François
2016-01-01
While it is commonly believed that animals live longer in zoos than in the wild, this assumption has rarely been tested. We compared four survival metrics (longevity, baseline mortality, onset of senescence and rate of senescence) between both sexes of free-ranging and zoo populations of more than 50 mammal species. We found that mammals from zoo populations generally lived longer than their wild counterparts (84% of species). The effect was most notable in species with a faster pace of life (i.e. a short life span, high reproductive rate and high mortality in the wild) because zoos evidently offer protection against a number of relevant conditions like predation, intraspecific competition and diseases. Species with a slower pace of life (i.e. a long life span, low reproduction rate and low mortality in the wild) benefit less from captivity in terms of longevity; in such species, there is probably less potential for a reduction in mortality. These findings provide a first general explanation about the different magnitude of zoo environment benefits among mammalian species, and thereby highlight the effort that is needed to improve captive conditions for slow-living species that are particularly susceptible to extinction in the wild. PMID:27819303
NASA Technical Reports Server (NTRS)
Ahamed, Aakash; Bolten, John; Doyle, C.; Fayne, Jessica
2016-01-01
Floods are the costliest natural disaster (United Nations 2004), causing approximately6.8 million deaths in the twentieth century alone (Doocy et al. 2013).Worldwide economic flood damage estimates in 2012 exceed $19 Billion USD(Munich Re 2013). Extended duration floods also pose longer term threats to food security, water, sanitation, hygiene, and community livelihoods, particularly in developing countries (Davies et al. 2014).Projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that precipitation extremes, rainfall intensity, storm intensity, and variability are increasing due to climate change (IPCC 2007). Increasing hydrologic uncertainty will likely lead to unprecedented extreme flood events. As such, there is a vital need to enhance and further develop traditional techniques used to rapidly assessflooding and extend analytical methods to estimate impacted population and infrastructure.
If We Can't Predict Solar Cycle 24, What About Solar Cycle 34?
NASA Technical Reports Server (NTRS)
Pesnell. William Dean
2008-01-01
Predictions of solar activity in Solar Cycle 24 range from 50% larger than SC 23 to the onset of a Grand Minimum. Because low levels of solar activity are associated with global cooling in paleoclimate and isotopic records, anticipating these extremes is required in any longterm extrapolation of climate variability. Climate models often look forward 100 or more years, which would mean 10 solar cycles into the future. Predictions of solar activity are derived from a number of methods, most of which, such as climatology and physics-based models, will be familiar to atmospheric scientists. More than 50 predictions of the maximum amplitude of SC 24 published before solar minimum will be discussed. Descriptions of several methods that result in the extreme predictions and some anticipation of even longer term predictions will be presented.
Effects of electrofishing gear type on spatial and temporal variability in fish community sampling
Meador, M.R.; McIntyre, J.P.
2003-01-01
Fish community data collected from 24 major river basins between 1993 and 1998 as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess multiple-reach (three consecutive reaches) and multiple-year (three consecutive years) variability in samples collected at a site. Variability was assessed using the coefficient of variation (CV; SD/mean) of species richness, the Jaccard index (JI), and the percent similarity index (PSI). Data were categorized by three electrofishing sample collection methods: backpack, towed barge, and boat. Overall, multiple-reach CV values were significantly lower than those for multiple years, whereas multiple-reach JI and PSI values were significantly greater than those for multiple years. Multiple-reach and multiple-year CV values did not vary significantly among electrofishing methods, although JI and PSI values were significantly greatest for backpack electrofishing across multiple reaches and multiple years. The absolute difference between mean species richness for multiple-reach samples and mean species richness for multiple-year samples was 0.8 species (9.5% of total species richness) for backpack samples, 1.7 species (10.1%) for towed-barge samples, and 4.5 species (24.4%) for boat-collected samples. Review of boat-collected fish samples indicated that representatives of four taxonomic families - Catostomidae, Centrarchidae, Cyprinidae, and Ictaluridae - were collected at all sites. Of these, catostomids exhibited greater interannual variability than centrarchids, cyprinids, or ictalurids. Caution should be exercised when combining boat-collected fish community data from different years because of relatively high interannual variability, which is primarily due to certain relatively mobile species. Such variability may obscure longer-term trends.
Environmental Drivers of Inter-annual Variability in Beaufort Sea Marine Fish Community Structure
NASA Astrophysics Data System (ADS)
Majewski, A.; Atchison, S.; Eert, J.; Dempsey, M.; MacPhee, S.; Michel, C.; Reist, J.
2016-02-01
The Beaufort Sea is a complex and dynamic system influenced by a wide suite of oceanic and riverine inputs that affect the ecosystem. Interactions within the resulting water masses are largely driven by factors such as precipitation, wind, and ice cover. Thus, the Beaufort Sea environment is highly variable in both space and time, and this variability is reflected in the habitats of biota. Inherent system variability must be factored into baselines designed to detect changes resulting from anthropogenic stressors and natural drivers. Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. In 2012, benthic trawling was conducted at 28 stations spanning 20-1000 m depths across shelf and slope habitats, and selected stations were re-sampled in 2013 and 2014. Concurrent sampling of oceanographic parameters and sediment composition was conducted at each station. We examine the stability of marine fish assemblages over a three-year period, and compare results for shelf stations to previous research to develop longer-term perspectives. Oceanographic (e.g., salinity), physical (e.g., depth and sediment grain size) and geographic (e.g., distance from shore) parameters, and proxies for local productivity (i.e., water-column and benthic chlorophyll) are explored as explanatory variables affecting fish community structure among years. Establishing knowledge baselines and understanding variability in the community structure and habitat associations of Beaufort Sea marine fishes will support mitigation and conservation efforts by enhancing our ability to predict, detect and monitor the effects of hydrocarbon development and climate change on this pivotal ecosystem component.
NASA Astrophysics Data System (ADS)
Jiang, Peng; Gautam, Mahesh R.; Zhu, Jianting; Yu, Zhongbo
2013-02-01
SummaryMulti-scale temporal variability of precipitation has an established relationship with floods and droughts. In this paper, we present the diagnostics on the ability of 16 General Circulation Models (GCMs) from Bias Corrected and Downscaled (BCSD) World Climate Research Program's (WCRP's) Coupled Model Inter-comparison Project Phase 3 (CMIP3) projections and 10 Regional Climate Models (RCMs) that participated in the North American Regional Climate Change Assessment Program (NARCCAP) to represent multi-scale temporal variability determined from the observed station data. Four regions (Los Angeles, Las Vegas, Tucson, and Cimarron) in the Southwest United States are selected as they represent four different precipitation regions classified by clustering method. We investigate how storm properties and seasonal, inter-annual, and decadal precipitation variabilities differed between GCMs/RCMs and observed records in these regions. We find that current GCMs/RCMs tend to simulate longer storm duration and lower storm intensity compared to those from observed records. Most GCMs/RCMs fail to produce the high-intensity summer storms caused by local convective heat transport associated with the summer monsoon. Both inter-annual and decadal bands are present in the GCM/RCM-simulated precipitation time series; however, these do not line up to the patterns of large-scale ocean oscillations such as El Nino/La Nina Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Our results show that the studied GCMs/RCMs can capture long-term monthly mean as the examined data is bias-corrected and downscaled, but fail to simulate the multi-scale precipitation variability including flood generating extreme events, which suggests their inadequacy for studies on floods and droughts that are strongly associated with multi-scale temporal precipitation variability.
NASA Astrophysics Data System (ADS)
Seaby, L. P.; Tague, C. L.; Hope, A. S.
2006-12-01
The Mediterranean type environments (MTEs) of California are characterized by a distinct wet and dry season and high variability in inter-annual climate. Water limitation in MTEs makes eco-hydrological processes highly sensitive to both climate variability and frequent fire disturbance. This research modeled post-fire eco- hydrologic behavior under historical and moderate and extreme scenarios of future climate in a semi-arid chaparral dominated southern California MTE. We used a physically-based, spatially-distributed, eco- hydrological model (RHESSys - Regional Hydro-Ecologic Simulation System), to capture linkages between water and vegetation response to the combined effects of fire and historic and future climate variability. We found post-fire eco-hydrologic behavior to be strongly influenced by the episodic nature of MTE climate, which intensifies under projected climate change. Higher rates of post-fire net primary productivity were found under moderate climate change, while more extreme climate change produced water stressed conditions which were less favorable for vegetation productivity. Precipitation variability in the historic record follows the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), and these inter-annual climate characteristics intensify under climate change. Inter-annual variation in streamflow follows these precipitation patterns. Post-fire streamflow and carbon cycling trajectories are strongly dependent on climate characteristics during the first 5 years following fire, and historic intra-climate variability during this period tends to overwhelm longer term trends and variation that might be attributable to climate change. Results have implications for water resource availability, vegetation type conversion from shrubs to grassland, and changes in ecosystem structure and function.
Rapid Evidence Review of Mobile Applications for Self-management of Diabetes.
Veazie, Stephanie; Winchell, Kara; Gilbert, Jennifer; Paynter, Robin; Ivlev, Ilya; Eden, Karen B; Nussbaum, Kerri; Weiskopf, Nicole; Guise, Jeanne-Marie; Helfand, Mark
2018-05-08
Patients with diabetes lack information on which commercially available applications (apps) improve diabetes-related outcomes. We conducted a rapid evidence review to examine features, clinical efficacy, and usability of apps for self-management of type 1 and type 2 diabetes in adults. Ovid/Medline and the Cochrane Database of Systematic Reviews were searched for systematic reviews and technology assessments. Reference lists of relevant systematic reviews were examined for primary studies. Additional searches for primary studies were conducted online, through Ovid/Medline, Embase, CINAHL, and ClinicalTrials.gov . Studies were evaluated for eligibility based on predetermined criteria, data were extracted, study quality was assessed using a risk of bias tool, information on app features was collected, and app usability was assessed. Results are summarized qualitatively. Fifteen articles evaluating 11 apps were identified: six apps for type 1 and five apps for type 2 diabetes. Common features of apps included setting reminders and tracking blood glucose and hemoglobin A1c (HbA1c), medication use, physical activity, and weight. Compared with controls, use of eight apps, when paired with support from a healthcare provider or study staff, improved at least one outcome, most often HbA1c. Patients did not experience improvements in quality of life, blood pressure, or weight, regardless of app used or type of diabetes. Study quality was variable. Of the eight apps available for usability testing, two were scored "acceptable," three were "marginal," and three were "not acceptable." Limited evidence suggests that use of some commercially available apps, when combined with additional support from a healthcare provider or study staff, may improve some short-term diabetes-related outcomes. The impact of these apps on longer-term outcomes is unclear. More rigorous and longer-term studies of apps are needed. This review was funded by the Agency for Healthcare Research and Quality (AHRQ). The protocol is available at: http://www.effectivehealthcare.ahrq.gov/topics/diabetes-mobile-devices/research-protocol .
Foster, Emma J; Barlas, Raphae S; Wood, Adrian D; Bettencourt-Silva, Joao H; Clark, Allan B; Metcalf, Anthony K; Bowles, Kristian M; Potter, John F; Myint, Phyo K
2017-10-01
The risks of falls and fractures increase after stroke. Little is known about the prognostic significance of previous falls and fractures after stroke. This study examined whether having a history of either event is associated with poststroke mortality. We analyzed stroke register data collected prospectively between 2003 and 2015. Eight sex-specific models were analyzed, to which the following variables were incrementally added to examine their potential confounding effects: age, type of stroke, Oxfordshire Community Stroke Project classification, previous comorbidities, frailty as indicated by the prestroke modified Rankin Scale score, and acute illness parameters. Logistic regression was applied to investigate in-hospital and 30-day mortality, and Cox proportional-hazards models were applied to investigate longer-term outcomes of mortality. In total, 10,477 patients with stroke (86.1% ischemic) were included in the analysis. They were aged 77.7±11.9 years (mean±SD), and 52.2% were women. A history of falls was present in 8.6% of the men (n=430) and 20.2% of the women (n=1,105), while 3.8% (n=189) of the men and 12.9% of the women (n=706) had a history of both falls and fractures. Of the outcomes examined, a history of falls alone was associated with increased in-hospital mortality [odds ratio (OR)=1.33, 95% confidence interval (CI)=1.03-1.71] and 30-day mortality (OR=1.34, 95% CI=1.03-1.73) in women in the fully adjusted models. The Cox proportional-hazards models for longer-term outcomes and the history of falls and fractures combined showed no significant results. The history of falls is an important factor for acute stroke mortality in women. A previous history of falls may therefore be an important factor to consider in the short-term stroke prognosis, particularly in women. Copyright © 2017 Korean Neurological Association
Kennamer, Robert A; Oldenkamp, Ricki E; Leaphart, James C; King, Joshua D; Bryan, A Lawrence; Beasley, James C
2017-05-01
Low-level releases of radiocesium into former nuclear reactor cooling-reservoirs on the U.S. Department of Energy's Savannah River Site (SRS) in South Carolina, USA, dating primarily to the late 1950s and early 1960s, have allowed examination of long-term contaminant attenuation in biota occupying these habitats. Periodic collections of migratory game birds since the 1970s have documented 137 Cs (radiocesium) activity concentrations in birds of SRS reservoirs, including mainly Par Pond and Pond B. In this study, during 2014 and 2015 we released wild-caught American coots (Fulica americana) and ring-necked ducks (Aythya collaris) onto Pond B. We made lethal collections of these same birds with residence times ranging from 32 to 173 days to examine radiocesium uptake and estimate the rate of natural attenuation. The two species achieved asymptotic whole-body activity concentrations of radiocesium at different times, with ring-necked ducks requiring almost three times longer than the 30-35 days needed by coots. We estimated ecological half-life (T e ) for Pond B coots over a 28-yr period as 16.8 yr (95% CI = 12.9-24.2 yr). Pond B coot T e was nearly four times longer than T e for coots at nearby Par Pond where radiocesium bioavailability had been constrained for decades by pumping of potassium-enriched river water into that reservoir. T e could not be estimated from long-term data for radiocesium in Pond B diving ducks, including ring-necked ducks, likely because of high variability in residence times of ducks on Pond B. Our results highlight the importance: (1) for risk managers to understand site-specific bio-geochemistry of radiocesium for successful implementation of countermeasures at contaminated sites and (2) of residence time as a critical determinant of observed radiocesium activity concentrations in highly mobile wildlife inhabiting contaminated habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Meher, J. K.; Das, L.
2017-12-01
The Western Himalayan Region (WHR) was subject to a significant negative trend in the annual and monsoon rainfall during 1902-2005. Annual and seasonal rainfall change over WHR of India was estimated using 22 rain gauge station rainfall data from the India Meteorological Department. The performance of 13 global climate models (GCMs) from the coupled model intercomparison project phase 3 (CMIP3) and 42 GCMs from CMIP5 was evaluated through multiple analysis: the evaluation of the mean annual cycle, annual cycles of interannual variability, spatial patterns, trends and signal-to-noise ratio. In general, CMIP5 GCMs were more skillful in terms of simulating the annual cycle of interannual variability compared to CMIP3 GCMs. The CMIP3 GCMs failed to reproduce the observed trend whereas 50% of the CMIP5 GCMs reproduced the statistical distribution of short-term (30-years) trend-estimates than for the longer term (99-years). GCMs from both CMIP3 and CMIP5 were able to simulate the spatial distribution of observed rainfall in pre-monsoon and winter months. Based on performance, each model of CMIP3 and CMIP5 was given an overall rank, which puts the high resolution version of the MIROC3.2 model (MIROC3.2 hires) and MIROC5 at the top in CMIP3 and CMIP5 respectively. Robustness of the ranking was judged through a sensitivity analysis, which indicated that ranks were independent during the process of adding or removing any individual method. It also revealed that trend analysis was not a robust method of judging performances of the model as compared to other methods.
Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.
Mellis, M G; Ingle, L; Carroll, S
2014-02-01
This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P < 0.001). Lower coefficient of variation (≤ 10.2%) and narrower limits of agreement were found for actual heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults. © Georg Thieme Verlag KG Stuttgart · New York.
Convergence and Accommodation Development Is Preprogrammed in Premature Infants.
Horwood, Anna M; Toor, Sonia S; Riddell, Patricia M
2015-08-01
This study investigated whether vergence and accommodation development in preterm infants is preprogrammed or is driven by experience. Thirty-two healthy infants, born at mean 34 weeks gestation (range, 31.2-36 weeks), were compared with 45 healthy full-term infants (mean 40.0 weeks) over a 6-month period, starting at 4 to 6 weeks postnatally. Simultaneous accommodation and convergence to a detailed target were measured using a Plusoptix PowerRefII infrared photorefractor as a target moved between 0.33 and 2 m. Stimulus/response gains and responses at 0.33 and 2 m were compared by both corrected (gestational) age and chronological (postnatal) age. When compared by their corrected age, preterm and full-term infants showed few significant differences in vergence and accommodation responses after 6 to 7 weeks of age. However, when compared by chronological age, preterm infants' responses were more variable, with significantly reduced vergence gains, reduced vergence response at 0.33 m, reduced accommodation gain, and increased accommodation at 2 m compared to full-term infants between 8 and 13 weeks after birth. When matched by corrected age, vergence and accommodation in preterm infants show few differences from full-term infants' responses. Maturation appears preprogrammed and is not advanced by visual experience. Longer periods of immature visual responses might leave preterm infants more at risk of development of oculomotor deficits such as strabismus.
Wang, Jiawu; Zhang, Chengyao; Tan, Dan; Tan, Guangzhong; Yang, Bo; Chen, Wenkai; Tang, Guoqiang
2016-01-01
To assess the safety and efficacy of local anesthetic infiltration around nephrostomy tract on postoperative pain control after percutaneous nephrolithotomy. This systematic review was performed based on randomized clinic trials about local anesthetic infiltration around nephrostomy tract on postoperative pain control. The weighted mean difference (WMD), with their corresponding 95% CI, was calculated to compare continuous variables. Our results showed that the consumption of analgesic was less in the experimental group than in the control group (WMD -25.32, 95% CI -48.09 to -2.55, p = 0.003). There was no significant difference between the mean Visual Analog Scale (VAS) in the experimental group than the control group after 6 h while significantly lower after 24 h. The time of first analgesic demand was significantly longer in the experimental group (WMD 2.19, 95% CI 0.98-3.41). There was no significant difference between 2 groups in terms of operation time, hemoglobin (Hb) alteration, and hospital stay. Local anesthetic infiltration around nephrostomy tract had similar efficacy in the control group in terms of operation time, Hb alteration, and hospital stay, but offers some potential advantages in terms of analgesia requirement, the time of first analgesic demand, and VAS-24 h. However, good quality and large studies with long-term follow-up are warranted for further research. © 2016 S. Karger AG, Basel.
Cross-scale impact of climate temporal variability on ecosystem water and carbon fluxes
Paschalis, Athanasios; Fatichi, Simone; Katul, Gabriel G.; ...
2015-08-07
While the importance of ecosystem functioning is undisputed in the context of climate change and Earth system modeling, the role of short-scale temporal variability of hydrometeorological forcing (~1 h) on the related ecosystem processes remains to be fully understood. Additionally, various impacts of meteorological forcing variability on water and carbon fluxes across a range of scales are explored here using numerical simulations. Synthetic meteorological drivers that highlight dynamic features of the short temporal scale in series of precipitation, temperature, and radiation are constructed. These drivers force a mechanistic ecohydrological model that propagates information content into the dynamics of water andmore » carbon fluxes for an ensemble of representative ecosystems. The focus of the analysis is on a cross-scale effect of the short-scale forcing variability on the modeled evapotranspiration and ecosystem carbon assimilation. Interannual variability of water and carbon fluxes is emphasized in the analysis. The main study inferences are summarized as follows: (a) short-scale variability of meteorological input does affect water and carbon fluxes across a wide range of time scales, spanning from the hourly to the annual and longer scales; (b) different ecosystems respond to the various characteristics of the short-scale variability of the climate forcing in various ways, depending on dominant factors limiting system productivity; (c) whenever short-scale variability of meteorological forcing influences primarily fast processes such as photosynthesis, its impact on the slow-scale variability of water and carbon fluxes is small; and (d) whenever short-scale variability of the meteorological forcing impacts slow processes such as movement and storage of water in the soil, the effects of the variability can propagate to annual and longer time scales.« less
Cross-scale impact of climate temporal variability on ecosystem water and carbon fluxes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Paschalis, Athanasios; Fatichi, Simone; Katul, Gabriel G.
While the importance of ecosystem functioning is undisputed in the context of climate change and Earth system modeling, the role of short-scale temporal variability of hydrometeorological forcing (~1 h) on the related ecosystem processes remains to be fully understood. Additionally, various impacts of meteorological forcing variability on water and carbon fluxes across a range of scales are explored here using numerical simulations. Synthetic meteorological drivers that highlight dynamic features of the short temporal scale in series of precipitation, temperature, and radiation are constructed. These drivers force a mechanistic ecohydrological model that propagates information content into the dynamics of water andmore » carbon fluxes for an ensemble of representative ecosystems. The focus of the analysis is on a cross-scale effect of the short-scale forcing variability on the modeled evapotranspiration and ecosystem carbon assimilation. Interannual variability of water and carbon fluxes is emphasized in the analysis. The main study inferences are summarized as follows: (a) short-scale variability of meteorological input does affect water and carbon fluxes across a wide range of time scales, spanning from the hourly to the annual and longer scales; (b) different ecosystems respond to the various characteristics of the short-scale variability of the climate forcing in various ways, depending on dominant factors limiting system productivity; (c) whenever short-scale variability of meteorological forcing influences primarily fast processes such as photosynthesis, its impact on the slow-scale variability of water and carbon fluxes is small; and (d) whenever short-scale variability of the meteorological forcing impacts slow processes such as movement and storage of water in the soil, the effects of the variability can propagate to annual and longer time scales.« less
Katory, Mark; McLean, Ross; Paez, Edgar; Kucukmetin, Ali; Naik, Raj
2017-07-01
Radical pelvic exenteration can be undertaken for locally invasive or recurrent disease in both colorectal and gynaecological malignancies. In the UK this procedure is usually undertaken by the respective surgical specialties who have undergone divergent surgical training. This study describes and compares outcomes between colorectal and gynae-oncological teams following pelvic exenteration for primary and recurrent gynaecological and colorectal cancers in a single-centre multi-disciplinary team. A retrospective review of consecutive pelvic exenteration patients undertaken over a nine-year period in a tertiary referral centre. Analyses comparing short- and long-term morbidity and mortality outcomes were undertaken by chi-square test for categorical variables and Mann-Whitney U for continuous variables. Cumulative survival rates were calculated according to the Kaplan-Meier method and factors associated with recurrence and survival determined using a Cox regression model. Thirty-four exenterations were undertaken; fourteen colorectal and twenty gynae-oncological. Morbidity was seen in 50% of colorectal and 75% of gynae-oncological patients. Recurrence was seen earlier and with greater frequency in the gynaeoncology group (44.4% and median time 11 months) than the colorectal group (21.4%, median time 41 months; p > 0.05). Survival in the gynae-oncology group was also lower than the colorectal group at 1-year (69.6% vs. 92.9%) and 5-years (58.0% vs. 92.9%; p = 0.115). The majority of gynae-oncological mortality occurred within 3-years of surgery, whilst the majority of mortality in the colorectal group was after 5-years. Long-term patient outcome measures, including disease recurrence and 5-year survival, for colorectal exenteration appear better than for gynaeoncology patients, however, no statistical significant difference exists between short-term outcome measures between specialties. This is likely to be caused by different baseline pathologies and disease pattern influencing longer term prognosis but may also be a function of differing surgical thresholds and patient selection bias between specialties. Peri-operative and short-term morbidity appear equivalent despite divergent surgical backgrounds and training. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.
Plumlee, Geoffrey S.; Hageman, Philip L.; Lamothe, Paul J.; Ziegler, Thomas L.; Meeker, Gregory P.; Theodorakos, Peter M.; Brownfield, Isabelle; Adams, Monique G.; Swayze, Gregg A.; Hoefen, Todd M.; Taggart, Joseph E.; Clark, Roger N.; Wilson, S.; Sutley, Stephen J.
2009-01-01
Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain water or water used in street washing and fire fighting. Chemical leach tests using deionized water as the extraction fluid show the dust samples can be quite alkaline, due primarily to reactions with calcium hydroxide in concrete particles. Calcium and sulfate are the most soluble components in the dust, but many other elements are also readily leached, including metals such as Al, Sb, Mo Cr, Cu, and Zn. Indoor dust samples produce leachates with higher pH, alkalinity, and dissolved solids than outdoor dust samples, suggesting most outdoor dust had reacted with water and atmospheric carbon dioxide prior to sample collection. Leach tests using simulated lung fluids as the extracting fluid suggest that the dust might also be quite reactive in fluids lining the respiratory tract, resulting in dissolution of some particles and possible precipitation of new phases such as phosphates, carbonates, and silicates. Results of these chemical characterization studies can be used by health scientists as they continue to track and interpret health effects resulting from the short-term exposure to the initial dust cloud and the longer-term exposure to dusts resuspended during cleanup.
Consideration of future safety consequences: a new predictor of employee safety.
Probst, Tahira M; Graso, Maja; Estrada, Armando X; Greer, Sarah
2013-06-01
Compliance with safety behaviors is often associated with longer term benefits, but may require some short-term sacrifices. This study examines the extent to which consideration of future safety consequences (CFSC) predicts employee safety outcomes. Two field studies were conducted to evaluate the reliability and validity of the newly developed Consideration of Future Safety Consequences (CFSC) scale. Surveys containing the CFSC scale and other measures of safety attitudes, behaviors, and outcomes were administered during working hours to a sample of 128 pulp and paper mill employees; after revising the CFSC scale based on these initial results, follow-up survey data were collected in a second sample of 212 copper miners. In Study I, CFSC was predictive of employee safety knowledge and motivation, compliance, safety citizenship behaviors, accident reporting attitudes and behaviors, and workplace injuries - even after accounting for conscientiousness and demographic variables. Moreover, the effects of CFSC on the variables generally appear to be direct, as opposed to mediated by safety knowledge or motivation. These findings were largely replicated in Study II. CFSC appears to be an important personality construct that may predict those individuals who are more likely to comply with safety rules and have more positive safety outcomes. Future research should examine the longitudinal stability of CFSC to determine the extent to which this construct is a stable trait, rather than a safety attitude amenable to change over time or following an intervention. Copyright © 2013 Elsevier Ltd. All rights reserved.
Lies, Damned Lies, and Health Inequality Measurements
Gerdtham, Ulf-G; Petrie, Dennis
2015-01-01
Measuring and monitoring socioeconomic health inequalities are critical for understanding the impact of policy decisions. However, the measurement of health inequality is far from value neutral, and one can easily present the measure that best supports one’s chosen conclusion or selectively exclude measures. Improving people’s understanding of the often implicit value judgments is therefore important to reduce the risk that researchers mislead or policymakers are misled. While the choice between relative and absolute inequality is already value laden, further complexities arise when, as is often the case, health variables have both a lower and upper bound, and thus can be expressed in terms of either attainments or shortfalls, such as for mortality/survival. We bring together the recent parallel discussions from epidemiology and health economics regarding health inequality measurement and provide a deeper understanding of the different value judgments within absolute and relative measures expressed both in attainments and shortfalls, by graphically illustrating both hypothetical and real examples. We show that relative measures in terms of attainments and shortfalls have distinct value judgments, highlighting that for health variables with two bounds the choice is no longer only between an absolute and a relative measure but between an absolute, an attainment- relative and a shortfall-relative one. We illustrate how these three value judgments can be combined onto a single graph which shows the rankings according to all three measures, and illustrates how the three measures provide ethical benchmarks against which to judge the difference in inequality between populations. PMID:26133019
X-ray Flaring Activity in HBL Source PKS 2155-304
NASA Astrophysics Data System (ADS)
Kapanadze, Bidzina
2013-08-01
We report an increasing X-ray flux through 0.3-10 keV band in the high-energy peaked BL Lacertae source PKS 2155-304 (z=0.117) which has been observed three times between 2013 July 25 and August 3 with the X-ray Telescope (XRT) onboard the Swift satellite. Using the data provided at the website http://www.swift.psu.edu/monitoring/ we have found that the object increased its 0.3-10 keV flux almost 3-times from 0.98+/-0.06 cts/s (July 25, ObsID=00030795114) to 2.85+/-0.08 cts/s corresponding to the observation performed July 31. The last pointing performed on August 3 (ObsID0008028002) shows even higher flux of 3.08+/-05 cts/s. No subhour flux variability at 99.9% confidence are detected from each observation, lasting 0.7 ks - 2.1 ks. On the basis of our recent study of long-term X-ray flux variability in this source (Kapanadze et al. 2013, submitted to the Monthly Notices of Royal Astronomical Society) we suggest that the similar situation was generally an indicator of the! onset of a longer-term flare with weeks-months duration. Therefore, further densely sampled observations with Swift-XRT and other X-ray instruments are highly recommended. Since X-ray flares in BL Lacertae sources are mostly followed by those in other spectral bands, we encourage intensive multiwavelength observations of PKS 2155-304.
NASA Astrophysics Data System (ADS)
Angelakis, E.
2012-01-01
The F-GAMMA program aims at understanding the physics at work in AGN via a multi-frequency monitoring approach. A number of roughly 65 Fermi-GST detectable blazars are being monitored monthly since January 2007 at radio wavelengths. The core program relies on the 100-m Effelsberg telescope operating at 8 frequencies between 2.6 and 43 GHz, the 30-m IRAM telescope observing at 86, 145 and 240 GHz and the APEX 12-m telescope at 345 GHz. For the targeted sources the LAT instrument onboard Fermi-GST provides gamma-ray light curves sampled daily. Here we discuss two recent findings: A). On the basis of their variability pattern, the observed quasi-simultaneous broad-band spectra can be classified to merely 5 classes. The variability for the first 4 is clearly dominated by spectral-evolution. Sources of the last class vary self-similarly with almost no apparent shift of the peak frequency. The former classes can be attributed to a two-component principal system made of a quiescent optically thin spectrum and a super-imposed flaring event. The later class must be interpreted in terms of a completely different mechanism. The apparent differences among the classes are explained in terms of a redshift modulus and an intrinsic-source/flare parameters modulus. Numerical simulations have shown that a shock-in-jet model can very well describe the observed behavior. It is concluded therefore that only two mechanisms seem to be producing variability. None of the almost 90 sources used for this study show a switch of class indicating that the variability mechanism is either (a) a finger-print of the source, or (b) remains stable on timescales far longer than the monitoring period of almost 4 years. B). Recently it has been disclosed that Narrow Line Seyfert 1 galaxies show gamma-ray emission. Within the F-GAMMA program radio jet emission has been detected from 3 such sources challenging the belief that jets are associated with elliptical galaxies. The recent findings in this area will be discussed.
North Atlantic sea-level variability during the last millennium
NASA Astrophysics Data System (ADS)
Gehrels, Roland; Long, Antony; Saher, Margot; Barlow, Natasha; Blaauw, Maarten; Haigh, Ivan; Woodworth, Philip
2014-05-01
Climate modelling studies have demonstrated that spatial and temporal sea-level variability observed in North Atlantic tide-gauge records is controlled by a complex array of processes, including ice-ocean mass exchange, freshwater forcing, steric changes, changes in wind fields, and variations in the speed of the Gulf Stream. Longer records of sea-level change, also covering the pre-industrial period, are important as a 'natural' and long-term baseline against which to test model performance and to place recent and future sea-level changes and ice-sheet change into a long-term context. Such records can only be reliably and continuously reconstructed from proxy methods. Salt marshes are capable of recording decimetre-scale sea-level variations with high precision and accuracy. In this paper we present four new high-resolution proxy records of (sub-) decadal sea-level variability reconstructed from salt-marsh sediments in Iceland, Nova Scotia, Maine and Connecticut that span the past 400 to 900 years. Our records, based on more than 100 new radiocarbon analyses, Pb-210 and Cs-137 measurements as well as other biological and geochemical age markers, together with hundreds of new microfossil observations from contemporary and fossil salt marshes, capture not only the rapid 20th century sea-level rise, but also small-scale (decimetre, multi-decadal) sea-level fluctuations during preceding centuries. We show that in Iceland three periods of rapid sea-level rise are synchronous with the three largest positive shifts of the reconstructed North Atlantic Oscillation (NAO) index. Along the North American east coast we compare our data with salt-marsh records from New Jersey, North Carolina and Florida and observe a trend of increased pre-industrial sea-level variability from south to north (Florida to Nova Scotia). Mass changes and freshwater forcing cannot explain this pattern. Based on comparisons with instrumental sea-level data and modelling studies we hypothesise that multi-decadal to centennial changes in wind and air pressure are more important than mass flux from land-based ice as drivers of North Atlantic sea-level variability during the last millennium.
A detailed X-ray investigation of ζ Puppis. IV. Further characterization of the variability
NASA Astrophysics Data System (ADS)
Nazé, Yaël; Ramiaramanantsoa, Tahina; Stevens, Ian R.; Howarth, Ian D.; Moffat, Anthony F. J.
2018-01-01
Context. One of the optically brightest and closest massive stars, ζ Pup, is also a bright X-ray source. Previously, its X-ray emission was found to be variable with light curves harbouring "trends" with a typical timescale longer than the exposure length, i.e. >1 d. The origin of these changes was proposed to be linked to large-scale structures in the wind of ζ Pup, but further characterization of the variability at high energies was needed to investigate this scenario. Aims: Since the previous papers of this series, a number of new X-ray observations have become available. Furthermore, a cyclic behaviour with a 1.78 d period was identified in long optical photometric runs, which is thought to be associated with the launching mechanism of large-scale wind structures. Methods: We analysed these new X-ray data, revisited the old data, and compared the X-ray light curves with the optical data, notably those taken simultaneously. Results: The behaviour of ζ Pup in X-rays cannot be explained in terms of a perfect clock because the amplitude and shape of its variations change with time. For example, ζ Pup was much more strongly variable between 2007 and 2011 than before and after this interval. Comparing the X-ray spectra of the star at maximum and minimum brightness yields no compelling difference beyond the overall flux change: the temperatures, absorptions, and line shapes seem to remain constant, well within errors. The only common feature between X-ray datasets is that the variation amplitudes appear maximum in the medium (0.6-1.2 keV) energy band. Finally, no clear and coherent correlation can be found between simultaneous X-ray and optical data. Only a subgroup of observations may be combined coherently with the optical period of 1.78 d, although the simultaneous optical behaviour is unknown. Conclusions: The currently available data do not reveal any obvious, permanent, and direct correlation between X-ray and optical variations. The origin of the X-ray variability therefore still needs to be ascertained, highlighting the need for long-term monitoring in multiwavelengths, i.e. X-ray, UV, and optical.
Variability in sea ice cover and climate elicit sex specific responses in an Antarctic predator
Labrousse, Sara; Sallée, Jean-Baptiste; Fraser, Alexander D.; Massom, Rob A.; Reid, Phillip; Hobbs, William; Guinet, Christophe; Harcourt, Robert; McMahon, Clive; Authier, Matthieu; Bailleul, Frédéric; Hindell, Mark A.; Charrassin, Jean-Benoit
2017-01-01
Contrasting regional changes in Southern Ocean sea ice have occurred over the last 30 years with distinct regional effects on ecosystem structure and function. Quantifying how Antarctic predators respond to such changes provides the context for predicting how climate variability/change will affect these assemblages into the future. Over an 11-year time-series, we examine how inter-annual variability in sea ice concentration and advance affect the foraging behaviour of a top Antarctic predator, the southern elephant seal. Females foraged longer in pack ice in years with greatest sea ice concentration and earliest sea ice advance, while males foraged longer in polynyas in years of lowest sea ice concentration. There was a positive relationship between near-surface meridional wind anomalies and female foraging effort, but not for males. This study reveals the complexities of foraging responses to climate forcing by a poleward migratory predator through varying sea ice property and dynamic anomalies. PMID:28233791
Variability in sea ice cover and climate elicit sex specific responses in an Antarctic predator.
Labrousse, Sara; Sallée, Jean-Baptiste; Fraser, Alexander D; Massom, Rob A; Reid, Phillip; Hobbs, William; Guinet, Christophe; Harcourt, Robert; McMahon, Clive; Authier, Matthieu; Bailleul, Frédéric; Hindell, Mark A; Charrassin, Jean-Benoit
2017-02-24
Contrasting regional changes in Southern Ocean sea ice have occurred over the last 30 years with distinct regional effects on ecosystem structure and function. Quantifying how Antarctic predators respond to such changes provides the context for predicting how climate variability/change will affect these assemblages into the future. Over an 11-year time-series, we examine how inter-annual variability in sea ice concentration and advance affect the foraging behaviour of a top Antarctic predator, the southern elephant seal. Females foraged longer in pack ice in years with greatest sea ice concentration and earliest sea ice advance, while males foraged longer in polynyas in years of lowest sea ice concentration. There was a positive relationship between near-surface meridional wind anomalies and female foraging effort, but not for males. This study reveals the complexities of foraging responses to climate forcing by a poleward migratory predator through varying sea ice property and dynamic anomalies.
EAR Program Research Results : Updated through 2013
DOT National Transportation Integrated Search
2013-12-31
The Exploratory Advanced Research (EAR) Program addresses the need for longer term, higher risk research with the potential for long-term improvements to transportation systemsimprovements in planning, building, renewing, and operating safe, conge...
EAR Program Research Results: Updated through 2014
DOT National Transportation Integrated Search
2014-12-31
The Exploratory Advanced Research (EAR) Program addresses the need for longer term, higher risk research with the potential for long-term improvements to transportation systemsimprovements in planning, building, renewing, and operating safe, conge...
EAR Program Research Results: Updated through 2016
DOT National Transportation Integrated Search
2016-12-31
The Exploratory Advanced Research (EAR) Program addresses the need for longer term, higher risk research with the potential for long-term improvements to transportation systemsimprovements in planning, building, renewing, and operating safe, conge...
Konstabel, Kenn; Lönnqvist, Jan-Erik; Leikas, Sointu; García Velázquez, Regina; Qin, Hiaying; Verkasalo, Markku; Walkowitz, Gari
2017-01-01
The aim of this study was to construct a short, 30-item personality questionnaire that would be, in terms of content and meaning of the scores, as comparable as possible with longer, well-established inventories such as NEO PI-R and its clones. To do this, we shortened the formerly constructed 60-item “Short Five” (S5) by half so that each subscale would be represented by a single item. We compared all possibilities of selecting 30 items (preserving balanced keying within each domain of the five-factor model) in terms of correlations with well-established scales, self-peer correlations, and clarity of meaning, and selected an optimal combination for each domain. The resulting shortened questionnaire, XS5, was compared to the original S5 using data from student samples in 6 different countries (Estonia, Finland, UK, Germany, Spain, and China), and a representative Finnish sample. The correlations between XS5 domain scales and their longer counterparts from well-established scales ranged from 0.74 to 0.84; the difference from the equivalent correlations for full version of S5 or from meta-analytic short-term dependability coefficients of NEO PI-R was not large. In terms of prediction of external criteria (emotional experience and self-reported behaviours), there were no important differences between XS5, S5, and the longer well-established scales. Controlling for acquiescence did not improve the prediction of criteria, self-peer correlations, or correlations with longer scales, but it did improve internal reliability and, in some analyses, comparability of the principal component structure. XS5 can be recommended as an economic measure of the five-factor model of personality at the level of domain scales; it has reasonable psychometric properties, fair correlations with longer well-established scales, and it can predict emotional experience and self-reported behaviours no worse than S5. When subscales are essential, we would still recommend using the full version of S5. PMID:28800630
Konstabel, Kenn; Lönnqvist, Jan-Erik; Leikas, Sointu; García Velázquez, Regina; Qin, Hiaying; Verkasalo, Markku; Walkowitz, Gari
2017-01-01
The aim of this study was to construct a short, 30-item personality questionnaire that would be, in terms of content and meaning of the scores, as comparable as possible with longer, well-established inventories such as NEO PI-R and its clones. To do this, we shortened the formerly constructed 60-item "Short Five" (S5) by half so that each subscale would be represented by a single item. We compared all possibilities of selecting 30 items (preserving balanced keying within each domain of the five-factor model) in terms of correlations with well-established scales, self-peer correlations, and clarity of meaning, and selected an optimal combination for each domain. The resulting shortened questionnaire, XS5, was compared to the original S5 using data from student samples in 6 different countries (Estonia, Finland, UK, Germany, Spain, and China), and a representative Finnish sample. The correlations between XS5 domain scales and their longer counterparts from well-established scales ranged from 0.74 to 0.84; the difference from the equivalent correlations for full version of S5 or from meta-analytic short-term dependability coefficients of NEO PI-R was not large. In terms of prediction of external criteria (emotional experience and self-reported behaviours), there were no important differences between XS5, S5, and the longer well-established scales. Controlling for acquiescence did not improve the prediction of criteria, self-peer correlations, or correlations with longer scales, but it did improve internal reliability and, in some analyses, comparability of the principal component structure. XS5 can be recommended as an economic measure of the five-factor model of personality at the level of domain scales; it has reasonable psychometric properties, fair correlations with longer well-established scales, and it can predict emotional experience and self-reported behaviours no worse than S5. When subscales are essential, we would still recommend using the full version of S5.
Crisaborole Ointment 2%: A Review in Mild to Moderate Atopic Dermatitis.
Hoy, Sheridan M
2017-12-01
Crisaborole ointment 2% (Eucrisa™) is a novel, anti-inflammatory inhibitor of phosphodiesterase 4 (PDE4) that is available in the USA for the topical treatment of mild to moderate atopic dermatitis in patients aged ≥ 2 years. In two short-term (28 days), identically designed, multicentre, phase III studies in this patient population, topical therapy with crisaborole ointment 2% reduced disease severity and pruritus severity compared with vehicle, with the effect established early and sustained over the course of treatment. Improvements in the other signs of atopic dermatitis (erythema, exudation, excoriation, induration/papulation, and lichenification) were also seen. Crisaborole ointment 2% was generally well tolerated in the short-term studies, with its favorable safety profile maintained over the longer term (up to 52 weeks) in a multicentre, extension study. Most treatment-emergent adverse events (TEAEs) were of mild to moderate severity and considered unrelated to the study medication. Moreover, the incidence of application-site pain following short- and longer-term topical therapy with crisaborole ointment 2% was low. In conclusion, crisaborole ointment 2% is an effective and generally well tolerated new topical option for the management of mild to moderate atopic dermatitis in patients aged ≥ 2 years, with the potential to effectively treat this patient population over the longer term without the safety concerns associated with other current topical anti-inflammatory agents.
Photometric long-term variations and superhump occurrence in the Classical Nova RR Pictoris
NASA Astrophysics Data System (ADS)
Fuentes-Morales, I.; Vogt, N.; Tappert, C.; Schmidtobreick, L.; Hambsch, F.-J.; Vučković, M.
2018-02-01
We present an analysis of all available time-resolved photometry from the literature and new light curves obtained in 2013-2014 for the old nova RR Pictoris. The well-known hump light curve phased with the orbital period reveals significant variations over the last 42 yr in shape, amplitude and other details which apparently are caused by long-term variations in the disc structure. In addition, we found evidence for the presence of superhumps in 2007, with the same period ( ˜ 9 per cent longer than the orbital period), as reported earlier by other authors from observations in 2005. Possibly, superhumps arise quickly in RR Pic, but are sporadic events, because in all the other observing runs analysed no significant superhump signal was detected. We also determined an actual version of the Stolz-Schoembs relation between superhump period and orbital period, analysing separately dwarf novae, classical novae and nova-like stars, and conclude that this relation is of general validity for all superhumpers among the cataclysmic variables (CVs), in spite of small but significant differences among the sub-types mentioned above. We emphasize the importance of such a study in context with the still open question of the interrelation between the different sub-classes of CVs, crucial for our understanding of the long-term CV evolution.
Stratospheric variability in summer
NASA Technical Reports Server (NTRS)
Rind, D.; Donn, W. L.; Robinson, W.
1981-01-01
Rocketsonde observations and infrasound results are used to investigate the variability of the summer stratopause region during one month in summer. Fluctuations of 2-3 days and about 16-day periods are evident, and they appear to be propagating vertically. In this month the 2-3 day oscillations have an amplitude envelope equal in period to the longer period oscillations, implying a connection between the two phenomena. Observations of the diurnal tide and shorter period variability during the month are also presented.
Variable response of three Trifolium repens ecotypes to soil flooding by seawater.
White, Anissia C; Colmer, Timothy D; Cawthray, Greg R; Hanley, Mick E
2014-08-01
Despite concerns about the impact of rising sea levels and storm surge events on coastal ecosystems, there is remarkably little information on the response of terrestrial coastal plant species to seawater inundation. The aim of this study was to elucidate responses of a glycophyte (white clover, Trifolium repens) to short-duration soil flooding by seawater and recovery following leaching of salts. Using plants cultivated from parent ecotypes collected from a natural soil salinity gradient, the impact of short-duration seawater soil flooding (8 or 24 h) on short-term changes in leaf salt ion and organic solute concentrations was examined, together with longer term impacts on plant growth (stolon elongation) and flowering. There was substantial Cl(-) and Na(+) accumulation in leaves, especially for plants subjected to 24 h soil flooding with seawater, but no consistent variation linked to parent plant provenance. Proline and sucrose concentrations also increased in plants following seawater flooding of the soil. Plant growth and flowering were reduced by longer soil immersion times (seawater flooding followed by drainage and freshwater inputs), but plants originating from more saline soil responded less negatively than those from lower salinity soil. The accumulation of proline and sucrose indicates a potential for solute accumulation as a response to the osmotic imbalance caused by salt ions, while variation in growth and flowering responses between ecotypes points to a natural adaptive capacity for tolerance of short-duration seawater soil flooding in T. repens. Consequently, it is suggested that selection for tolerant ecotypes is possible should the predicted increase in frequency of storm surge flooding events occur. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Aylward, Lesa L; Hays, Sean M; Zidek, Angelika
2017-01-01
Population biomonitoring data sets such as the Canadian Health Measures Survey (CHMS) and the United States National Health and Nutrition Examination Survey (NHANES) collect and analyze spot urine samples for analysis for biomarkers of exposure to non-persistent chemicals. Estimation of population intakes using such data sets in a risk-assessment context requires consideration of intra- and inter-individual variability to understand the relationship between variation in the biomarker concentrations and variation in the underlying daily and longer-term intakes. Two intensive data sets with a total of 16 individuals with collection and measurement of serial urine voids over multiple days were used to examine these relationships using methyl paraben, triclosan, bisphenol A (BPA), monoethyl phthalate (MEP), and mono-2-ethylhexyl hydroxyl phthalate (MEHHP) as example compounds. Composited 24 h voids were constructed mathematically from the individual collected voids, and concentrations for each 24 h period and average multiday concentrations were calculated for each individual in the data sets. Geometric mean and 95th percentiles were compared to assess the relationship between distributions in spot sample concentrations and the 24 h and multiday collection averages. In these data sets, spot sample concentrations at the 95th percentile were similar to or slightly higher than the 95th percentile of the distribution of all 24 h composite void concentrations, but tended to overestimate the maximum of the multiday concentration averages for most analytes (usually by less than a factor of 2). These observations can assist in the interpretation of population distributions of spot samples for frequently detected analytes with relatively short elimination half-lives. PMID:27703149
Challapalli, Sai D; Simpson, Matthew C; Adjei Boakye, Eric; Pannu, Jay S; Costa, Dary J; Osazuwa-Peters, Nosayaba
2018-05-10
Adolescent and young adult (AYA) head and neck cancer (HNC) patients require longer term follow-ups as they age; yet, little is known about factors associated with survivorship in this population. We aimed to describe nonclinical factors associated with HNC survivorship among AYAs. In this retrospective cohort study, the Surveillance, Epidemiology and End Results 18 database from 2007 to 2014 was queried. Eligible cases were 15-39-year-old primary HNC patients with known cause of death (n = 1777). Kaplan-Meier survival curves stratified by age group (15-29, 30-34, and 35-39) and by health insurance status tested differences in HNC survival among groups with a log-rank test. Variables, including age, sex, race/ethnicity, county-level poverty, anatomic site, stage, and treatment, were controlled for in a competing risk proportional hazards model. Patients were mostly male (64%), with mean age of 33.4 years. Survival rate was 73% after 8 years of follow-up. There were no significant survival differences based on age at diagnosis. However, AYAs who were on Medicaid (adjusted hazard ratio [aHR] = 1.61, 95% confidence interval [CI] 1.22-2.12) or uninsured (aHR = 1.51, 95% CI 1.03-2.21), had an increased hazard of death from HNC, compared with those with private insurance. Health insurance status is the main nonclinical factor associated with survival among AYAs with HNC, and individuals with Medicaid do not fare better than the uninsured. With a potential longer term follow-up in this AYA population, there is need to optimize survivorship irrespective of health insurance status.
Macalady, Alison K.; Bugmann, Harald
2014-01-01
The processes leading to drought-associated tree mortality are poorly understood, particularly long-term predisposing factors, memory effects, and variability in mortality processes and thresholds in space and time. We use tree rings from four sites to investigate Pinus edulis mortality during two drought periods in the southwestern USA. We draw on recent sampling and archived collections to (1) analyze P. edulis growth patterns and mortality during the 1950s and 2000s droughts; (2) determine the influence of climate and competition on growth in trees that died and survived; and (3) derive regression models of growth-mortality risk and evaluate their performance across space and time. Recent growth was 53% higher in surviving vs. dying trees, with some sites exhibiting decades-long growth divergences associated with previous drought. Differential growth response to climate partly explained growth differences between live and dead trees, with responses wet/cool conditions most influencing eventual tree status. Competition constrained tree growth, and reduced trees’ ability to respond to favorable climate. The best predictors in growth-mortality models included long-term (15–30 year) average growth rate combined with a metric of growth variability and the number of abrupt growth increases over 15 and 10 years, respectively. The most parsimonious models had high discriminatory power (ROC>0.84) and correctly classified ∼70% of trees, suggesting that aspects of tree growth, especially over decades, can be powerful predictors of widespread drought-associated die-off. However, model discrimination varied across sites and drought events. Weaker growth-mortality relationships and higher growth at lower survival probabilities for some sites during the 2000s event suggest a shift in mortality processes from longer-term growth-related constraints to shorter-term processes, such as rapid metabolic decline even in vigorous trees due to acute drought stress, and/or increases in the attack rate of both chronically stressed and more vigorous trees by bark beetles. PMID:24786646
Remote sensing evaluation of CLM4 GPP for the period 2000 to 2009
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mao, Jiafu; Thornton, Peter E; Shi, Xiaoying
2012-01-01
The ability of a process-based ecosystem model like Version 4 of the Community Land Model (CLM4) to provide accurate estimates of CO2 flux is a top priority for researchers, modelers and policy makers. Remote sensing can provide long-term and large scale products suitable for ecosystem model evaluation. Global estimations of gross primary production (GPP) at the 1 km spatial resolution from years 2000 to 2009 from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor offer a unique opportunity for evaluating the temporal and spatial patterns of global GPP and its relationship with climate for CLM4. We compare monthly GPP simulated bymore » CLM4 at half-degree resolution with satellite estimates of GPP from the MODIS GPP (MOD17) dataset for the 10-yr period, January 2000 December 2009. The assessment is presented in terms of long-term mean carbon assimilation, seasonal mean distributions, amplitude and phase of the annual cycle, and intra-annual and inter-annual GPP variability and their responses to climate variables. For the long-term annual and seasonal means, major GPP patterns are clearly demonstrated by both products. Compared to the MODIS product, CLM4 overestimates the magnitude of GPP for tropical evergreen forests. CLM4 has longer carbon uptake period than MODIS for most plant functional types (PFTs) with an earlier onset of GPP in spring and later decline of GPP in autumn. Empirical Orthogonal Function (EOF) analysis of the monthly GPP changes indicates that on the intra-annual scale, both CLM4 and MODIS display similar spatial representations and temporal patterns for most terrestrial ecosystems except in northeast Russia and the very dry region in central Australia. For 2000-2009, CLM4 simulates increases in annual averaged GPP over both hemispheres, however estimates from MODIS suggest a reduction in the Southern Hemisphere (-0.2173 PgC/year) balancing the significant increase over the Northern Hemisphere (0.2157 PgC/year).« less
Lanki, Timo; Siponen, Taina; Ojala, Ann; Korpela, Kalevi; Pennanen, Arto; Tiittanen, Pekka; Tsunetsugu, Yuko; Kagawa, Takahide; Tyrväinen, Liisa
2017-11-01
Epidemiological studies have reported positive associations between the amount of green space in the living environment and mental and cardiovascular human health. In a search for effect mechanisms, field studies have found short-term visits to green environments to be associated with psychological stress relief. Less evidence is available on the effect of visits on cardiovascular physiology. To evaluate whether visits to urban green environments, in comparison to visits to a built-up environment, lead to beneficial short-term changes in indicators of cardiovascular health. Thirty-six adult female volunteers visited three different types of urban environments: an urban forest, an urban park, and a built-up city centre, in Helsinki, Finland. The visits consisted of 15min of sedentary viewing, and 30min of walking. During the visits, blood pressure and heart rate were measured, and electrocardiogram recorded for the determination of indicators of heart rate variability. In addition, levels of respirable ambient particles and environmental noise were monitored. Visits to the green environments were associated with lower blood pressure (viewing period only), lower heart rate, and higher indices of heart rate variability [standard deviation of normal-to-normal intervals (SDNN), high frequency power] than visits to the city centre. In the green environments, heart rate decreased and SDNN increased during the visit. Associations between environment and indicators of cardiovascular health weakened slightly after inclusion of particulate air pollution and noise in the models. Visits to urban green environments are associated with beneficial short-term changes in cardiovascular risk factors. This can be explained by psychological stress relief with contribution from reduced air pollution and noise exposure during the visits. Future research should evaluate the amount of exposure to green environments needed for longer-term benefits for cardiovascular health. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Mears, R P; Klein, A C; Cromwell, H C
2006-08-11
Medial prefrontal cortex is a crucial region involved in inhibitory processes. Damage to the medial prefrontal cortex can lead to loss of normal inhibitory control over motor, sensory, emotional and cognitive functions. The goal of the present study was to examine the basic properties of inhibitory gating in this brain region in rats. Inhibitory gating has recently been proposed as a neurophysiological assay for sensory filters in higher brain regions that potentially enable or disable information throughput. This perspective has important clinical relevance due to the findings that gating is dramatically impaired in individuals with emotional and cognitive impairments (i.e. schizophrenia). We used the standard inhibitory gating two-tone paradigm with a 500 ms interval between tones and a 10 s interval between tone pairs. We recorded both single unit and local field potentials from chronic microwire arrays implanted in the medial prefrontal cortex. We investigated short-term (within session) and long-term (between session) variability of auditory gating and additionally examined how altering the interval between the tones influenced the potency of the inhibition. The local field potentials displayed greater variability with a reduction in the amplitudes of the tone responses over both the short and long-term time windows. The decrease across sessions was most intense for the second tone response (test tone) leading to a more robust gating (lower T/C ratio). Surprisingly, single unit responses of different varieties retained similar levels of auditory responsiveness and inhibition in both the short and long-term analysis. Neural inhibition decreased monotonically related to the increase in intertone interval. This change in gating was most consistent in the local field potentials. Subsets of single unit responses did not show the lack of inhibition even for the longer intertone intervals tested (4 s interval). These findings support the idea that the medial prefrontal cortex is an important site where early inhibitory functions reside and potentially mediate psychological processes.
Macalady, Alison K; Bugmann, Harald
2014-01-01
The processes leading to drought-associated tree mortality are poorly understood, particularly long-term predisposing factors, memory effects, and variability in mortality processes and thresholds in space and time. We use tree rings from four sites to investigate Pinus edulis mortality during two drought periods in the southwestern USA. We draw on recent sampling and archived collections to (1) analyze P. edulis growth patterns and mortality during the 1950s and 2000s droughts; (2) determine the influence of climate and competition on growth in trees that died and survived; and (3) derive regression models of growth-mortality risk and evaluate their performance across space and time. Recent growth was 53% higher in surviving vs. dying trees, with some sites exhibiting decades-long growth divergences associated with previous drought. Differential growth response to climate partly explained growth differences between live and dead trees, with responses wet/cool conditions most influencing eventual tree status. Competition constrained tree growth, and reduced trees' ability to respond to favorable climate. The best predictors in growth-mortality models included long-term (15-30 year) average growth rate combined with a metric of growth variability and the number of abrupt growth increases over 15 and 10 years, respectively. The most parsimonious models had high discriminatory power (ROC>0.84) and correctly classified ∼ 70% of trees, suggesting that aspects of tree growth, especially over decades, can be powerful predictors of widespread drought-associated die-off. However, model discrimination varied across sites and drought events. Weaker growth-mortality relationships and higher growth at lower survival probabilities for some sites during the 2000s event suggest a shift in mortality processes from longer-term growth-related constraints to shorter-term processes, such as rapid metabolic decline even in vigorous trees due to acute drought stress, and/or increases in the attack rate of both chronically stressed and more vigorous trees by bark beetles.
A neuromorphic circuit mimicking biological short-term memory.
Barzegarjalali, Saeid; Parker, Alice C
2016-08-01
Research shows that the way we remember things for a few seconds is a different mechanism from the way we remember things for a longer time. Short-term memory is based on persistently firing neurons, whereas storing information for a longer time is based on strengthening the synapses or even forming new neural connections. Information about location and appearance of an object is segregated and processed by separate neurons. Furthermore neurons can continue firing using different mechanisms. Here, we have designed a biomimetic neuromorphic circuit that mimics short-term memory by firing neurons, using biological mechanisms to remember location and shape of an object. Our neuromorphic circuit has a hybrid architecture. Neurons are designed with CMOS 45nm technology and synapses are designed with carbon nanotubes (CNT).
Gender role attitudes and other determinants of breast feeding intentions in Brazilian women.
Paine, P; Dorea, J G
2001-01-01
This study of 230 Brazilian mothers examined the associations of several sociodemographic variables, maternal attitudes and perceptions with intended breast feeding duration. The usual relationships of sociodemographic variables such as mother's age, education, smoking, parity and infant birth weight with intended breast feeding duration were not found. However, mother's intentions were related to gender role attitudes with both the least and the most traditional women intending to breast feed longer than women with moderately traditional gender role attitudes. Mother's attitude toward breast feeding, help with household tasks, and the attitudes of friends and relatives toward breast feeding were also very significantly related to intended breast feeding duration. Women who did not work outside the home intended to breast feed significantly longer than those who were employed.
Adaptation Challenges in Complex River Basins: Lessons Learned and Unlearned for the Colorado
NASA Astrophysics Data System (ADS)
Pulwarty, R. S.
2008-12-01
Climate variations affect the function and operation of existing water infrastructure - including hydropower, structural flood defenses, drainage and irrigation systems - as well as water management practices in support of efficiency and environmental needs. Selected basins around the world, including the Colorado, show agreements in model projections of increasing aridity. Adverse effects of climate change on freshwater systems aggravate the impacts of other stresses, such as population growth, changing economic activity, land-use change and urbanization and most importantly upstream-downstream winners and losers. Thus current water management practices may not be robust enough to cope with the impacts of climate change on water supply reliability. In many locations, water management does not even satisfactorily cope with current climate variability, so that large flood and drought-related environmental and economic damages occur on seasonal to decadal timescales. The recently released IPCC Technical Paper notes that adaptation procedures and risk management practices that incorporate projected hydrological changes with related uncertainties are being developed in some countries and regions.In this presentation we will review the challenges and lessons provided in drought and water resources management and optimization in the context of climate variability and projected change in the Western U.S., the European Union (including the Iberian Peninsula), the Murray-Darling Basin, and elsewhere. Since the release of the IPCC report several of the authors (including the presenter) have held meetings on comparative assessments of adaptation and its challenges in interstate and international river basins. As a first step, improved incorporation of information about current climate variability into water-related management could assist adaptation to longer-term climate change impacts. Future adaptations include technical changes that improve water use efficiency, demand management (e.g. through metering and pricing), and institutional changes that improve the tradability of water rights. The co-evolution of climate history and adaptation did not start with the release of IPCC scenarios. The development of the Colorado River Basin was itself influenced by water resources planners from around the world (including the Middle East) in the late 1800s. As such lessons identified, but not always learned, abound. These hold considerable promise for water savings and the reallocation of water to highly valued uses. Supply-side strategies generally involve increases in storage capacity, abstraction from watercourses, and water transfers. Integrated water resources management provides an important governance framework to achieve adaptation measures across socio-economic, environmental and administrative systems. However, several paradoxes in water management and governance mitigate against the effectiveness of scientific information for meeting short term needs in the context of reducing longer-term vulnerabilities and for providing water to meet environmental needs. Consequently a complete analysis of the effects of climate change on human water uses would consider cross-sector interactions, including the impacts of changes in water use efficiency and intentional transfers of the use of water from one sector to another.
Matzopoulos, Richard
2016-05-19
Reducing firearm mortality by means of stricter gun control is one of the most important short- to medium-term measures to address the burden of violence in South Africa, while longer-term interventions and policy measures take effect.
Amitraz (CAS 33089-61-1) is a formamidine insecticide and acaricide used on crops, livestock, and pets. Neurotoxicity is the primary endpoint of concern for short-term exposures in nontarget species. Amitraz has hepatic, reproductive, and developmental effects with longer-term...
Long-Term Effects of a Home-Visiting Intervention for Depressed Mothers and Their Infants
ERIC Educational Resources Information Center
Kersten-Alvarez, Laura E.; Hosman, Clemens M. H.; Riksen-Walraven, J. Marianne; Van Doesum, Karin T. M.; Hoefnagels, Cees
2010-01-01
Background: Whereas preventive interventions for depressed mothers and their infants have yielded positive short-term outcomes, few studies have examined their long-term effectiveness. The present follow-up of a randomised controlled trial (RCT) is one of the first to examine the longer-term effects of an intervention for mothers with postpartum…
Surgeon and type of anesthesia predict variability in surgical procedure times.
Strum, D P; Sampson, A R; May, J H; Vargas, L G
2000-05-01
Variability in surgical procedure times increases the cost of healthcare delivery by increasing both the underutilization and overutilization of expensive surgical resources. To reduce variability in surgical procedure times, we must identify and study its sources. Our data set consisted of all surgeries performed over a 7-yr period at a large teaching hospital, resulting in 46,322 surgical cases. To study factors associated with variability in surgical procedure times, data mining techniques were used to segment and focus the data so that the analyses would be both technically and intellectually feasible. The data were subdivided into 40 representative segments of manageable size and variability based on headers adopted from the common procedural terminology classification. Each data segment was then analyzed using a main-effects linear model to identify and quantify specific sources of variability in surgical procedure times. The single most important source of variability in surgical procedure times was surgeon effect. Type of anesthesia, age, gender, and American Society of Anesthesiologists risk class were additional sources of variability. Intrinsic case-specific variability, unexplained by any of the preceding factors, was found to be highest for shorter surgeries relative to longer procedures. Variability in procedure times among surgeons was a multiplicative function (proportionate to time) of surgical time and total procedure time, such that as procedure times increased, variability in surgeons' surgical time increased proportionately. Surgeon-specific variability should be considered when building scheduling heuristics for longer surgeries. Results concerning variability in surgical procedure times due to factors such as type of anesthesia, age, gender, and American Society of Anesthesiologists risk class may be extrapolated to scheduling in other institutions, although specifics on individual surgeons may not. This research identifies factors associated with variability in surgical procedure times, knowledge of which may ultimately be used to improve surgical scheduling and operating room utilization.
Effects of red-cell storage duration on patients undergoing cardiac surgery.
Steiner, Marie E; Ness, Paul M; Assmann, Susan F; Triulzi, Darrell J; Sloan, Steven R; Delaney, Meghan; Granger, Suzanne; Bennett-Guerrero, Elliott; Blajchman, Morris A; Scavo, Vincent; Carson, Jeffrey L; Levy, Jerrold H; Whitman, Glenn; D'Andrea, Pamela; Pulkrabek, Shelley; Ortel, Thomas L; Bornikova, Larissa; Raife, Thomas; Puca, Kathleen E; Kaufman, Richard M; Nuttall, Gregory A; Young, Pampee P; Youssef, Samuel; Engelman, Richard; Greilich, Philip E; Miles, Ronald; Josephson, Cassandra D; Bracey, Arthur; Cooke, Rhonda; McCullough, Jeffrey; Hunsaker, Robert; Uhl, Lynne; McFarland, Janice G; Park, Yara; Cushing, Melissa M; Klodell, Charles T; Karanam, Ravindra; Roberts, Pamela R; Dyke, Cornelius; Hod, Eldad A; Stowell, Christopher P
2015-04-09
Some observational studies have reported that transfusion of red-cell units that have been stored for more than 2 to 3 weeks is associated with serious, even fatal, adverse events. Patients undergoing cardiac surgery may be especially vulnerable to the adverse effects of transfusion. We conducted a randomized trial at multiple sites from 2010 to 2014. Participants 12 years of age or older who were undergoing complex cardiac surgery and were likely to undergo transfusion of red cells were randomly assigned to receive leukocyte-reduced red cells stored for 10 days or less (shorter-term storage group) or for 21 days or more (longer-term storage group) for all intraoperative and postoperative transfusions. The primary outcome was the change in Multiple Organ Dysfunction Score (MODS; range, 0 to 24, with higher scores indicating more severe organ dysfunction) from the preoperative score to the highest composite score through day 7 or the time of death or discharge. The median storage time of red-cell units provided to the 1098 participants who received red-cell transfusion was 7 days in the shorter-term storage group and 28 days in the longer-term storage group. The mean change in MODS was an increase of 8.5 and 8.7 points, respectively (95% confidence interval for the difference, -0.6 to 0.3; P=0.44). The 7-day mortality was 2.8% in the shorter-term storage group and 2.0% in the longer-term storage group (P=0.43); 28-day mortality was 4.4% and 5.3%, respectively (P=0.57). Adverse events did not differ significantly between groups except that hyperbilirubinemia was more common in the longer-term storage group. The duration of red-cell storage was not associated with significant differences in the change in MODS. We did not find that the transfusion of red cells stored for 10 days or less was superior to the transfusion of red cells stored for 21 days or more among patients 12 years of age or older who were undergoing complex cardiac surgery. (Funded by the National Heart, Lung, and Blood Institute; RECESS ClinicalTrials.gov number, NCT00991341.).
Influence of musical groove on postural sway.
Ross, Jessica M; Warlaumont, Anne S; Abney, Drew H; Rigoli, Lillian M; Balasubramaniam, Ramesh
2016-03-01
Timescales of postural fluctuation reflect underlying neuromuscular processes in balance control that are influenced by sensory information and the performance of concurrent cognitive and motor tasks. An open question is how postural fluctuations entrain to complex environmental rhythms, such as in music, which also vary on multiple timescales. Musical groove describes the property of music that encourages auditory-motor synchronization and is used to study voluntary motor entrainment to rhythmic sounds. The influence of groove on balance control mechanisms remains unexplored. We recorded fluctuations in center of pressure (CoP) of standing participants (N = 40) listening to low and high groove music and during quiet stance. We found an effect of musical groove on radial sway variability, with the least amount of variability in the high groove condition. In addition, we observed that groove influenced postural sway entrainment at various temporal scales. For example, with increasing levels of groove, we observed more entrainment to shorter, local timescale rhythmic musical occurrences. In contrast, we observed more entrainment to longer, global timescale features of the music, such as periodicity, with decreasing levels of groove. Finally, musical experience influenced the amount of postural variability and entrainment at local and global timescales. We conclude that groove in music and musical experience can influence the neural mechanisms that govern balance control, and discuss implications of our findings in terms of multiscale sensorimotor coupling. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Feeser, Dianne L
2011-01-01
This article challenges conventional wisdom that calciphylaxis is a rare condition. Rather, emerging evidence suggests that calciphylaxis is neither rare nor uncommon. In addition, the term calciphylaxis is questioned because misrepresents the underlying etiology of the condition. Multiple researchers and clinicians advocate abandoning the use of the term, but nursing literature has not yet followed suit. This article reviews the epidemiology, clinical manifestations, diagnosis, prevention, and treatment of this condition and associated wounds, and suggests areas for future research. The WOC nurse's role as an educator, leader, researcher, clinical expert, and patient advocate is summarized.
ERIC Educational Resources Information Center
Rousseau, Isabelle; Packman, Ann; Onslow, Mark; Harrison, Elisabeth; Jones, Mark
2007-01-01
Knowledge of variables that predict treatment time is of benefit in deciding when to start treatment for early stuttering. To date, the only variable clearly related to treatment time with the Lidcombe Program is pre-treatment stuttering frequency. Previous studies have shown that children whose stuttering is more severe take longer to complete…
Ostoja, Steven M.; Brooks, Matthew L.; Dudley, Tom; Lee, Steven R.
2014-01-01
and species diversity were very low, suggesting that targets of restoring vegetation to pre-invasion conditions were not met. Longer evaluation periods are needed to adequately evaluate how short-term post-treatment patterns translate to long-term patterns of plant community dynamics.
UV Reconstruction Algorithm And Diurnal Cycle Variability
NASA Astrophysics Data System (ADS)
Curylo, Aleksander; Litynska, Zenobia; Krzyscin, Janusz; Bogdanska, Barbara
2009-03-01
UV reconstruction is a method of estimation of surface UV with the use of available actinometrical and aerological measurements. UV reconstruction is necessary for the study of long-term UV change. A typical series of UV measurements is not longer than 15 years, which is too short for trend estimation. The essential problem in the reconstruction algorithm is the good parameterization of clouds. In our previous algorithm we used an empirical relation between Cloud Modification Factor (CMF) in global radiation and CMF in UV. The CMF is defined as the ratio between measured and modelled irradiances. Clear sky irradiance was calculated with a solar radiative transfer model. In the proposed algorithm, the time variability of global radiation during the diurnal cycle is used as an additional source of information. For elaborating an improved reconstruction algorithm relevant data from Legionowo [52.4 N, 21.0 E, 96 m a.s.l], Poland were collected with the following instruments: NILU-UV multi channel radiometer, Kipp&Zonen pyranometer, radiosonde profiles of ozone, humidity and temperature. The proposed algorithm has been used for reconstruction of UV at four Polish sites: Mikolajki, Kolobrzeg, Warszawa-Bielany and Zakopane since the early 1960s. Krzyscin's reconstruction of total ozone has been used in the calculations.
A climatology of total ozone mapping spectrometer data using rotated principal component analysis
NASA Astrophysics Data System (ADS)
Eder, Brian K.; Leduc, Sharon K.; Sickles, Joseph E.
1999-02-01
The spatial and temporal variability of total column ozone (Ω) obtained from the total ozone mapping spectrometer (TOMS version 7.0) during the period 1980-1992 was examined through the use of a multivariate statistical technique called rotated principal component analysis. Utilization of Kaiser's varimax orthogonal rotation led to the identification of 14, mostly contiguous subregions that together accounted for more than 70% of the total Ω variance. Each subregion displayed statistically unique Ω characteristics that were further examined through time series and spectral density analyses, revealing significant periodicities on semiannual, annual, quasi-biennial, and longer term time frames. This analysis facilitated identification of the probable mechanisms responsible for the variability of Ω within the 14 homogeneous subregions. The mechanisms were either dynamical in nature (i.e., advection associated with baroclinic waves, the quasi-biennial oscillation, or El Niño-Southern Oscillation) or photochemical in nature (i.e., production of odd oxygen (O or O3) associated with the annual progression of the Sun). The analysis has also revealed that the influence of a data retrieval artifact, found in equatorial latitudes of version 6.0 of the TOMS data, has been reduced in version 7.0.
Yawn Contagion and Empathy in Homo sapiens
Norscia, Ivan; Palagi, Elisabetta
2011-01-01
The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed models applied to observational data collected over 1 year on adult (>16 years old) human subjects. Only social bonding predicted the occurrence, frequency, and latency of yawn contagion. As with other measures of empathy, the rate of contagion was greatest in response to kin, then friends, then acquaintances, and lastly strangers. Related individuals (r≥0.25) showed the greatest contagion, in terms of both occurrence of yawning and frequency of yawns. Strangers and acquaintances showed a longer delay in the yawn response (latency) compared to friends and kin. This outcome suggests that the neuronal activation magnitude related to yawn contagion can differ as a function of subject familiarity. In conclusion, our results demonstrate that yawn contagion is primarily driven by the emotional closeness between individuals and not by other variables, such as gender and nationality. PMID:22163307
Financial Planning for Retirement: A Psychosocial Perspective
Topa, Gabriela; Lunceford, Gregg; Boyatzis, Richard E.
2018-01-01
Retirement is a time of life that has grown ever longer in the developed world, and the number of pensioners has increased accordingly, questioning the strength of Social Security systems and the social safety net in general. Financial Planning for Retirement (FRP) consists of the series of activities involved in the accumulation of wealth to cover needs in the post-retirement stage of life. The negative short-, mid-, and long-term consequences of inadequate Financial Planning for Retirement do not only affect individuals, but also their extended families, homes, eventually producing an unwanted impact on the entire society. The Capacity-Willingness-Opportunity Model has been proposed to understand FPR, combined with Intentional Change Theory, a framework for understanding the process, antecedents and consequences of FPR. From this perspective, we propose this promising model, but there are a large number of variables that have not been included that offer novel ways to deepen our understanding of FPR. A focus on each dimension of the model, the role of age and psychosocial variables associated with demographic indicators such as gender, health status, and migration, allow us to provide a proposal of scientific advancement of FPR. PMID:29416519
Yawn contagion and empathy in Homo sapiens.
Norscia, Ivan; Palagi, Elisabetta
2011-01-01
The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed models applied to observational data collected over 1 year on adult (>16 years old) human subjects. Only social bonding predicted the occurrence, frequency, and latency of yawn contagion. As with other measures of empathy, the rate of contagion was greatest in response to kin, then friends, then acquaintances, and lastly strangers. Related individuals (r≥0.25) showed the greatest contagion, in terms of both occurrence of yawning and frequency of yawns. Strangers and acquaintances showed a longer delay in the yawn response (latency) compared to friends and kin. This outcome suggests that the neuronal activation magnitude related to yawn contagion can differ as a function of subject familiarity. In conclusion, our results demonstrate that yawn contagion is primarily driven by the emotional closeness between individuals and not by other variables, such as gender and nationality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Withers, C.; Cummings, J.; Nigusse, B.
A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied bymore » adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.« less
INTEGRAL Long-Term Monitoring of the Supergiant Fast X-Ray Transient XTE J1739-302
NASA Technical Reports Server (NTRS)
Blay, P.; Martinez-Nunez, S.; Negueruela, I.; Pottschmidt, K.; Smith, D. M.; Torrejon, J. M.; Reig, P.; Kretschmar, P.; Kreykenbohm, I.
2008-01-01
Context. In the past few years, a new class of High Mass X-Ray Binaries (HMXRB) has been claimed to exist, the Supergiant Fast X-ray Transients (SFXT). These are X-ray binary systems with a compact companion orbiting a supergiant star which show very short and bright outbursts in a series of activity periods overimposed on longer quiescent periods. Only very recently the first attempts to model the behaviour of these sources have been published, some of them within the framework of accretion from clumpy stellar winds. Aims. Our goal is to analyze the properties of XTE J1739-302/IGR J17391-3021 within the context of the clumpy structure of the supergiant wind. Methods. We have used INTEGRAL and RXTE/PCA observations in order to obtain broad band (1 - 200 keV) spectra and light curves of XTE J1739-302 and investigate its X-ray spectrum and temporal variability. Results. We have found that XTE J1739-302 follows a much more complex behaviour than expected. Far from presenting a regular variability pattern, XTE J1739-302 shows periods of high, intermediate, and low flaring activity.
Late-Holocene climate andecosystem history from Chesapeake Bay sediment cores, USA
Willard, D.A.; Cronin, T. M.; Verardo, S.
2003-01-01
Palaeoclimate records from late-Holocene sediments in Chesapeake Bay, the largest estuary in the USA, provide evidence that both decadal to centennial climate variability and European colonization had severe impacts on the watershed and estuary. Using pollen and dinoflagellate cysts as proxies for mid-Atlantic regional precipitation, estuarine salinity and dissolved oxygen (DO) during the last 2300 years, we identified four dry intervals, centred on AD 50 (P1/D1), AD 1000 (P2/D2), AD 1400 (P3) and AD 1600 (P4). Two centennial-scale events, P1/D1 and P2/D2, altered forest composition and led to increased salinity and DO levels in the estuary. Intervals P3 and P4 lasted several decades, leading to decreased production of pine pollen. Periods of dry mid-Atlantic climate correspond to 'megadroughts' identified from tree-ring records in the southeastern and central USA. The observed mid-Atlantic climate variability may be explained by changes in atmospheric circulation resulting in longer-term, perhaps amplified, intervals of meridional flow. After European colonization in the early seventeenth century, forest clearance for agriculture, timber and urbanization altered estuarine water quality, with dinoflagellate assemblages indicating reduced DO and increased turbidity.
Heart rate variability and occupational stress-systematic review.
Järvelin-Pasanen, Susanna; Sinikallio, Sanna; Tarvainen, Mika P
2018-06-16
The aim of this systematic review was to explore studies regarding association between occupational stress and heart rate variability (HRV) during work. We searched PubMed, Web of Science, Scopus, Cinahl and PsycINFO for peer-reviewed articles published in English between January 2005 and September 2017. A total of 10 articles met the inclusion criteria. The included articles were analyzed in terms of study design, study population, assessment of occupational stress and HRV, and the study limitations. Among the studies there were cross-sectional (n=9) studies and one longitudinal study design. Sample size varied from 19 to 653 participants and both females and males were included. The most common assessment methods of occupational stress were the Job Content Questionnaire (JCQ) and the Effort-Reward Imbalance (ERI) questionnaire. HRV was assessed using 24-hours or longer Holter ECG or HR monitoring and analyzed mostly using standard time-domain and frequency-domain parameters. The main finding was that heightened occupational stress was found associated with lowered HRV, specifically with reduced parasympathetic activation. Reduced parasympathetic activation was seen as decreases in RMSSD and HF power, and increase in LF/HF ratio. The assessment and analysis methods of occupational stress and HRV were diverse.
Global lake response to the recent warming hiatus
NASA Astrophysics Data System (ADS)
Winslow, Luke A.; Leach, Taylor H.; Rose, Kevin C.
2018-05-01
Understanding temporal variability in lake warming rates over decadal scales is important for understanding observed change in aquatic systems. We analyzed a global dataset of lake surface water temperature observations (1985‑2009) to examine how lake temperatures responded to a recent global air temperature warming hiatus (1998‑2012). Prior to the hiatus (1985‑1998), surface water temperatures significantly increased at an average rate of 0.532 °C decade‑1 (±0.214). In contrast, water temperatures did not change significantly during the hiatus (average rate ‑0.087 °C decade‑1 ±0.223). Overall, 83% of lakes in our dataset (129 of 155) had faster warming rates during the pre-hiatus period than during the hiatus period. These results demonstrate that lakes have exhibited decadal-scale variability in warming rates coherent with global air temperatures and represent an independent line of evidence for the recent warming hiatus. Our analyses provide evidence that lakes are sentinels of broader climatological processes and indicate that warming rates based on datasets where a large proportion of observations were collected during the hiatus period may underestimate longer-term trends.
Financial Planning for Retirement: A Psychosocial Perspective.
Topa, Gabriela; Lunceford, Gregg; Boyatzis, Richard E
2017-01-01
Retirement is a time of life that has grown ever longer in the developed world, and the number of pensioners has increased accordingly, questioning the strength of Social Security systems and the social safety net in general. Financial Planning for Retirement (FRP) consists of the series of activities involved in the accumulation of wealth to cover needs in the post-retirement stage of life. The negative short-, mid-, and long-term consequences of inadequate Financial Planning for Retirement do not only affect individuals, but also their extended families, homes, eventually producing an unwanted impact on the entire society. The Capacity-Willingness-Opportunity Model has been proposed to understand FPR, combined with Intentional Change Theory, a framework for understanding the process, antecedents and consequences of FPR. From this perspective, we propose this promising model, but there are a large number of variables that have not been included that offer novel ways to deepen our understanding of FPR. A focus on each dimension of the model, the role of age and psychosocial variables associated with demographic indicators such as gender, health status, and migration, allow us to provide a proposal of scientific advancement of FPR.
Therapeutics of diabetes mellitus: focus on insulin analogues and insulin pumps.
Valla, Vasiliki
2010-01-01
Inadequately controlled diabetes accounts for chronic complications and increases mortality. Its therapeutic management aims in normal HbA1C, prandial and postprandial glucose levels. This review discusses diabetes management focusing on the latest insulin analogues, alternative insulin delivery systems and the artificial pancreas. Intensive insulin therapy with multiple daily injections (MDI) allows better imitation of the physiological rhythm of insulin secretion. Longer-acting, basal insulin analogues provide concomitant improvements in safety, efficacy and variability of glycaemic control, followed by low risks of hypoglycaemia. Continuous subcutaneous insulin infusion (CSII) provides long-term glycaemic control especially in type 1 diabetic patients, while reducing hypoglycaemic episodes and glycaemic variability. Continuous subcutaneous glucose monitoring (CGM) systems provide information on postprandial glucose excursions and nocturnal hypo- and/or hyperglycemias. This information enhances treatment options, provides a useful tool for self-monitoring and allows safer achievement of treatment targets. In the absence of a cure-like pancreas or islets transplants, artificial "closed-loop" systems mimicking the pancreatic activity have been also developed. Individualized treatment plans for insulin initiation and administration mode are critical in achieving target glycaemic levels. Progress in these fields is expected to facilitate and improve the quality of life of diabetic patients.
Switanek, Matthew; Crailsheim, Karl; Truhetz, Heimo; Brodschneider, Robert
2017-02-01
Insect pollinators are essential to global food production. For this reason, it is alarming that honey bee (Apis mellifera) populations across the world have recently seen increased rates of mortality. These changes in colony mortality are often ascribed to one or more factors including parasites, diseases, pesticides, nutrition, habitat dynamics, weather and/or climate. However, the effect of climate on colony mortality has never been demonstrated. Therefore, in this study, we focus on longer-term weather conditions and/or climate's influence on honey bee winter mortality rates across Austria. Statistical correlations between monthly climate variables and winter mortality rates were investigated. Our results indicate that warmer and drier weather conditions in the preceding year were accompanied by increased winter mortality. We subsequently built a statistical model to predict colony mortality using temperature and precipitation data as predictors. Our model reduces the mean absolute error between predicted and observed colony mortalities by 9% and is statistically significant at the 99.9% confidence level. This is the first study to show clear evidence of a link between climate variability and honey bee winter mortality. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.
Young, Hayley A.
2018-01-01
As the influence of diet on health may take place over a period of decades, there is a need for biomarkers that help to identify those aspects of nutrition that have either a positive or a negative influence. The evidence is considered that heart-rate variability (HRV) (the time differences between one beat and the next) can be used to indicate the potential health benefits of food items. Reduced HRV is associated with the development of numerous conditions for example, diabetes, cardiovascular disease, inflammation, obesity and psychiatric disorders. Although more systematic research is required, various aspects of diet have been shown to benefit HRV acutely and in the longer term. Examples include a Mediterranean diet, omega-3 fatty acids, B-vitamins, probiotics, polyphenols and weight loss. Aspects of diet that are viewed as undesirable, for example high intakes of saturated or trans-fat and high glycaemic carbohydrates, have been found to reduce HRV. It is argued that the consistent relationship between HRV, health and morbidity supports the view that HRV has the potential to become a widely used biomarker when considering the influence of diet on mental and physical health. PMID:29543648
Perspectives for short timescale variability studies with Gaia
NASA Astrophysics Data System (ADS)
Roelens, M.; Eyer, L.; Mowlavi, N.; Lecoeur-Taïbi, I.; Rimoldini, L.; Blanco-Cuaresma, S.; Palaversa, L.; Süveges, M.; Charnas, J.; Wevers, T.
2017-12-01
We assess the potential of Gaia for detecting and characterizing short timescale variables, i.e. at timescale from a few seconds to a dozen hours, through extensive light-curve simulations for various short timescale variable types, including both periodic and non-periodic variability. We evidence that the variogram analysis applied to Gaia photometry should enable to detect such fast variability phenomena, down to amplitudes of a few millimagnitudes, with limited contamination from longer timescale variables or constant sources. This approach also gives valuable information on the typical timescale(s) of the considered variation, which could complement results of classical period search methods, and help prepare ground-based follow-up of the Gaia short timescale candidates.
5 CFR 412.401 - Continuing executive development.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Section 412.401 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS SUPERVISORY, MANAGEMENT, AND EXECUTIVE DEVELOPMENT Executive Development § 412.401 Continuing executive... participation in short-term and longer-term experiences, meet organizational needs for leadership, managerial...
5 CFR 412.401 - Continuing executive development.
Code of Federal Regulations, 2011 CFR
2011-01-01
... participation in short-term and longer-term experiences, meet organizational needs for leadership, managerial improvement, and organizational results; (2) Address enhancement of existing executive competencies and such other competencies as will strengthen the executive's performance; (3) Outline developmental...
Learning and the Spiral Illusion
ERIC Educational Resources Information Center
Houtman, S. D.
1974-01-01
The purpose of the experiment was to ascertain whether the duration of the spiral illusion could be extended by a 'learning procedure' which would distinguish a longer-term learning effect from short-term adaptive changes due to inhibition. (Author)
Is There a Delay in Diagnosis of Duchenne Muscular Dystrophy Among Preterm-Born Males?
Soim, Aida; Smith, Michael G; Kwon, Jennifer M; Mann, Joshua R; Thomas, Shiny; Ciafaloni, Emma
2018-07-01
The objective of this study was to investigate whether males who were born preterm took longer to receive a Duchenne muscular dystrophy diagnosis than term males. Data for males with Duchenne muscular dystrophy identified through a population-based surveillance system were analyzed using a Kaplan-Meier estimator. The first signs and symptoms were noted at a median age of 2 years in both groups. Median age when first signs and symptoms prompted medical evaluation was 2.59 years among preterm and 4.01 years among term males. Median age at definitive diagnosis was 4.25 years and 4.92 years for preterm and term males, respectively. Neither difference was statistically significant. Preterm males tended to be seen for their initial medical evaluation earlier than term males, though they were not diagnosed significantly earlier. It may take clinicians longer after the initial evaluation of preterm males to arrive at a Duchenne muscular dystrophy diagnosis.
Whatever Became of the Learning City?
ERIC Educational Resources Information Center
Yarnit, Martin
2015-01-01
During the 1990s, the UK Learning City Network was a large and influential movement with government support, the most significant national body of its kind anywhere. Yet, less than a decade later, it was in decline and now no longer exists. But while few UK towns or cities any longer use the term "learning city", the notion lives on as…
NASA Technical Reports Server (NTRS)
Mason, E.; Orio, M.; Mukai, K.; Bianchini, A.; deMartino, D.; diMille, F.; Williams, R. E.
2013-01-01
We present new X-ray and optical spectra of the old nova CP Pup (nova Pup 1942) obtained with Chandra and the CTIO 4m telescope. The X-ray spectrum reveals a multi-temperature optically thin plasma reaching a maximum temperature of 36+19 keV 16 absorbed by local complex neutral material. The time resolved optical spectroscopy confirms the presence of the 1.47 hr period, with cycle-to-cycle amplitude changes, as well as of an additional long term modulation which is suggestive either of a longer pe- riod or of non-Keplerian velocities in the emission line regions. These new observational facts add further support to CP Pup as a magnetic cataclysmic variable (mCV). We compare the mCV and the non-mCV scenarios and while we cannot conclude whether CP Pup is a long period system, all observational evidences point at an intermediate polar (IP) type CV.
X-ray time lags in PG 1211+143
NASA Astrophysics Data System (ADS)
Lobban, A. P.; Vaughan, S.; Pounds, K.; Reeves, J. N.
2018-05-01
We investigate the X-ray time lags of a recent ˜630 ks XMM-Newton observation of PG 1211+143. We find well-correlated variations across the XMM-Newton EPIC bandpass, with the first detection of a hard lag in this source with a mean time delay of up to ˜3 ks at the lowest frequencies. We find that the energy-dependence of the low-frequency hard lag scales approximately linearly with log(E) when averaged over all orbits, consistent with the propagating fluctuations model. However, we find that the low-frequency lag behaviour becomes more complex on time-scales longer than a single orbit, suggestive of additional modes of variability. We also detect a high-frequency soft lag at ˜10-4 Hz with the magnitude of the delay peaking at ≲ 0.8 ks, consistent with previous observations, which we discuss in terms of small-scale reverberation.
Systematic cloning of human minisatellites from ordered array charomid libraries.
Armour, J A; Povey, S; Jeremiah, S; Jeffreys, A J
1990-11-01
We present a rapid and efficient method for the isolation of minisatellite loci from human DNA. The method combines cloning a size-selected fraction of human MboI DNA fragments in a charomid vector with hybridization screening of the library in ordered array. Size-selection of large MboI fragments enriches for the longer, more variable minisatellites and reduces the size of the library required. The library was screened with a series of multi-locus probes known to detect a large number of hypervariable loci in human DNA. The gridded library allowed both the rapid processing of positive clones and the comparative evaluation of the different multi-locus probes used, in terms of both the relative success in detecting hypervariable loci and the degree of overlap between the sets of loci detected. We report 23 new human minisatellite loci isolated by this method, which map to 14 autosomes and the sex chromosomes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rosa, R.R.; Colligan, M.J.; Lewis, P.
1986-06-01
A newly instituted 3 to 4 day/12-hr rotating shift schedule was compared to the previous 5 to 7 day/8-hr schedule using standard laboratory-type measures of performance and alertness, and a questionnaire on sleep patterns and other personal habits. After seven months adaptation to the new schedule, a preliminary analysis indicates that there were some decrements in alertness, reductions in sleep, and disruptions of other personal activities during 12-hr workdays. Gastro-intestinal state improved during night shift, however, and increases in self-reported stress were reduced by the shortened workweek. These results are discussed in terms of trade-offs between longer workdays and shortermore » workweeks. It is emphasized that at this time no determination can be made of the extent of risk associated with these changes in alertness.« less
Carbon pollution increases health inequities: lessons in resilience from the most vulnerable.
Ebi, Kristie L; Fawcett, Stephen B; Spiegel, Jerry; Tovalin, Horacio
2016-09-01
Climate change is a social justice as well as an environmental issue. The magnitude and pattern of changes in weather and climate variables are creating differential exposures, vulnerabilities, and health risks that increase stress on health systems while exacerbating existing and creating new health inequities. Examples from national and local health adaptation projects highlight that developing partnerships across sectors and levels are critical for building climate-resilient health systems and communities. Strengthening current and implementing new health interventions, such as using environmental information to develop early warning systems, can be effective in protecting the most vulnerable. However, not all projected risks of climate change can be avoided by climate policies and programs, so health system strengthening is also critical. Applying a health inequity lens can reduce current vulnerabilities while building resilience to longer-term climate change. Taking inequities into account is critical if societies are to effectively prepare for and manage the challenges ahead.
Cannabis use and cancer of the head and neck: case-control study.
Aldington, Sarah; Harwood, Matire; Cox, Brian; Weatherall, Mark; Beckert, Lutz; Hansell, Anna; Pritchard, Alison; Robinson, Geoffrey; Beasley, Richard
2008-03-01
To investigate whether cannabis smoking increases the risk of head and neck cancer. Case-control study. Cases of head and neck cancer < or =55 years identified from hospital databases and the Cancer Registry, and controls randomly selected from the electoral roll completed interviewer-administered questionnaires. Logistic regression was used to estimate the relative risk of head and neck cancer. There were 75 cases and 319 controls. An increased risk of cancer was found with increasing tobacco use, alcohol consumption, and decreased income but not increasing cannabis use. The highest tertile of cannabis use (>8.3 joint years) was associated with a nonsignificant increased risk of cancer (relative risk = 1.6, 95% confidence interval, 0.5-5.2) after adjustment for confounding variables. Cannabis use did not increase the risk of head and neck cancer; however, because of the limited power and duration of use studied, a small or longer-term effect cannot be excluded.
Predicting long-term citation impact of articles in social and personality psychology.
Haslam, Nick; Koval, Peter
2010-06-01
The citation impact of a comprehensive sample of articles published in social and personality psychology journals in 1998 was evaluated. Potential predictors of the 10-yr. citation impact of 1580 articles from 37 journals were investigated, including number of authors, number of references, journal impact factor, author nationality, and article length, using linear regression. The impact factor of the journal in which articles appeared was the primary predictor of the citations that they accrued, accounting for 30% of the total variance. Articles with greater length, more references, and more authors were cited relatively often, although the citation advantage of longer articles was not proportionate to their length. A citation advantage was also enjoyed by authors from the United States of America, Canada, and the United Kingdom. 37% of the variance in the total number of citations was accounted for by the study variables.
Russo, Gabrielle A
2016-01-01
This study evaluated the relationship between the morphology of the sacrum-the sole bony link between the tail or coccyx and the rest of the body-and tail length (including presence/absence) and function using a comparative sample of extant mammals spanning six orders (Primates, Carnivora, Rodentia, Diprotodontia, Pilosa, Scandentia; N = 472). Phylogenetically-informed regression methods were used to assess how tail length varied with respect to 11 external and internal (i.e., trabecular) bony sacral variables with known or suspected biomechanical significance across all mammals, only primates, and only non-primates. Sacral variables were also evaluated for primates assigned to tail categories ('tailless,' 'nonprehensile short-tailed,' 'nonprehensile long-tailed,' and 'prehensile-tailed'). Compared to primates with reduced tail lengths, primates with longer tails generally exhibited sacra having larger caudal neural openings than cranial neural openings, and last sacral vertebrae with more mediolaterally-expanded caudal articular surfaces than cranial articular surfaces, more laterally-expanded transverse processes, more dorsally-projecting spinous processes, and larger caudal articular surface areas. Observations were corroborated by the comparative sample, which showed that shorter-tailed (e.g., Lynx rufus [bobcat]) and longer-tailed (e.g., Acinonyx jubatus [cheetah]) non-primate mammals morphologically converge with shorter-tailed (e.g., Macaca nemestrina) and longer-tailed (e.g., Macaca fascicularis) primates, respectively. 'Prehensile-tailed' primates exhibited last sacral vertebrae with more laterally-expanded transverse processes and greater caudal articular surface areas than 'nonprehensile long-tailed' primates. Internal sacral variables performed poorly compared to external sacral variables in analyses of extant primates, and were thus deemed less useful for making inferences concerning tail length and function in extinct primates. The tails lengths of five extinct primates were reconstructed from the external sacral variables: Archaeolemur edwardsi had a 'nonprehensile long tail,' Megaladapis grandidieri, Palaeopropithecus kelyus, and Epipliopithecus vindobonensis probably had 'nonprehensile short tails,' and Proconsul heseloni was 'tailless.' Copyright © 2015 Elsevier Ltd. All rights reserved.
Large-scale forcing of the European Slope Current and associated inflows to the North Sea
NASA Astrophysics Data System (ADS)
Marsh, Robert; Haigh, Ivan; Cunningham, Stuart; Inall, Mark; Porter, Marie; Moat, Ben
2017-04-01
Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988-2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely "recruited" from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25-50% reductions of these density gradients over 1996-1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10-40% of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a clear decline in this Atlantic inflow over 1988-2007. The influence of variable Slope Current transport on the northern North Sea is also expressed in salinity variations. A proxy for Atlantic inflow may be found in sea level records. Variability of Slope Current transport is implicit in mean sea level differences between Lerwick (Shetland) and Torshavn (Faeroes), in both tide gauge records and a longer model hindcast spanning 1958-2013. Potential impacts of this variability on North Sea biogeochemistry and ecosystems, via associated changes in temperature and seasonal stratification, are discussed.
Delayed build-up of Arctic ice sheets during 400,000-year minima in insolation variability.
Hao, Qingzhen; Wang, Luo; Oldfield, Frank; Peng, Shuzhen; Qin, Li; Song, Yang; Xu, Bing; Qiao, Yansong; Bloemendal, Jan; Guo, Zhengtang
2012-10-18
Knowledge of the past variability of climate at high northern latitudes during astronomical analogues of the present interglacial may help to inform our understanding of future climate change. Unfortunately, long-term continuous records of ice-sheet variability in the Northern Hemisphere only are scarce because records of benthic (18)O content represent an integrated signal of changes in ice volume in both polar regions. However, variations in Northern Hemisphere ice sheets influence the Siberian High (an atmospheric pressure system), so variations in the East Asian winter monsoon (EAWM)--as recorded in the aeolian dust deposits on the Chinese Loess Plateau--can serve as a useful proxy of Arctic climate variability before the ice-core record begins. Here we present an EAWM proxy record using grain-size variations in two parallel loess sections representative of sequences across the whole of the Chinese Loess Plateau over the past 900,000 years. The results show that during periods of low eccentricity and precessional variability at approximately 400,000-year intervals, the grain-size-inferred intensity of the EAWM remains weak for up to 20,000 years after the end of the interglacial episode of high summer monsoon activity and strong pedogenesis. In contrast, there is a rapid increase in the EAWM after the end of most other interglacials. We conclude that, for both the 400,000-year interglacials, the weak EAWM winds maintain a mild, non-glacial climate at high northern latitudes for much longer than expected from the conventional loess and marine oxygen isotope records. During these times, the less-severe summer insolation minima at 65° N (ref. 4) would have suppressed ice and snow accumulation, leading to a weak Siberian High and, consequently, weak EAWM winds.
Forster, Anne; Young, John; Chapman, Katie; Nixon, Jane; Patel, Anita; Holloway, Ivana; Mellish, Kirste; Anwar, Shamaila; Breen, Rachel; Knapp, Martin; Murray, Jenni; Farrin, Amanda
2015-08-01
We developed a new postdischarge system of care comprising a structured assessment covering longer-term problems experienced by patients with stroke and their carers, linked to evidence-based treatment algorithms and reference guides (the longer-term stroke care system of care) to address the poor longer-term recovery experienced by many patients with stroke. A pragmatic, multicentre, cluster randomized controlled trial of this system of care. Eligible patients referred to community-based Stroke Care Coordinators were randomized to receive the new system of care or usual practice. The primary outcome was improved patient psychological well-being (General Health Questionnaire-12) at 6 months; secondary outcomes included functional outcomes for patients, carer outcomes, and cost-effectiveness. Follow-up was through self-completed postal questionnaires at 6 and 12 months. Thirty-two stroke services were randomized (29 participated); 800 patients (399 control; 401 intervention) and 208 carers (100 control; 108 intervention) were recruited. In intention to treat analysis, the adjusted difference in patient General Health Questionnaire-12 mean scores at 6 months was -0.6 points (95% confidence interval, -1.8 to 0.7; P=0.394) indicating no evidence of statistically significant difference between the groups. Costs of Stroke Care Coordinator inputs, total health and social care costs, and quality-adjusted life year gains at 6 months, 12 months, and over the year were similar between the groups. This robust trial demonstrated no benefit in clinical or cost-effectiveness outcomes associated with the new system of care compared with usual Stroke Care Coordinator practice. URL: http://www.controlled-trials.com. Unique identifier: ISRCTN 67932305. © 2015 Bradford Teaching Hospitals NHS Foundation Trust.
Breast feeding and child behaviour in the Millennium Cohort Study.
Heikkilä, Katriina; Sacker, Amanda; Kelly, Yvonne; Renfrew, Mary J; Quigley, Maria A
2011-07-01
To examine whether breast feeding is associated with behavioural development in children aged 5 years. The authors used data from a large, prospective, nationally representative UK cohort, the Millennium Cohort Study. 10 037 mother-child pairs from white ethnic background (9525 term and 512 preterm children) were included in the analyses. Duration of breast feeding (at all or exclusively) was ascertained from parental interview at study baseline, when the children were aged 9 months. Child behaviour was assessed using a parent-completed questionnaire, the Strengths and Difficulties Questionnaire (SDQ). The authors used logistic regression to investigate the associations of breastfeeding duration with abnormal parent-rated SDQ total and subscores at age 5 in term and preterm children separately. Abnormal SDQ scores were less common in term children (n=1129/9525, 12%) than pre-term (n=78/512, 15%) children. Term children breast fed for 4 months or longer (n=2741/9525, 29%) had lower odds of an abnormal total SDQ score (multivariable-adjusted OR compared with never breastfed children (n=3292/9525, 35%) 0.67, 95% CI: 0.54 to 0.83). This effect was similar for all the SDQ subscores. In preterm children, longer duration of breast feeding was generally associated with lower odds of abnormal SDQ total and subscores but the effect estimates were imprecise. The associations between exclusive breast feeding and abnormal SDQ scores were similar to those of any breast feeding and abnormal SDQ scores. The findings suggest that, at least in term children, longer duration of breast feeding is associated with fewer parent-rated behavioural problems in children aged 5 years.
Circumstellar dust in symbiotic novae
NASA Astrophysics Data System (ADS)
Jurkic, Tomislav; Kotnik-Karuza, Dubravka
2015-08-01
Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding evolution of symbiotic binaries. We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the long-term near-IR photometry, infrared ISO spectra and mid-IR interferometry. Pulsation properties and long-term variabilities were found from the near-IR light curves. The dust properties were determined using the DUSTY code which solves the radiative transfer. No changes in pulsational parameters were found, but a long-term variations with periods of 20-25 years have been detected which cannot be attributed to orbital motion.Circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel showed the presence of an optically thin CS dust envelope and an optically thick dust region outside the line of sight, which was further supported by the detailed modelling using the 2D LELUYA code. Obscuration events in RR Tel were explained by an increase in optical depth caused by the newly condensed dust leading to the formation of a compact dust shell. HM Sge showed permanent obscuration and a presence of a compact dust shell with a variable optical depth. Scattering of the near-IR colours can be understood by a change in sublimation temperature caused by the Mira variability. Presence of large dust grains (up to 4 µm) suggests an increased grain growth in conditions of increased mass loss. The mass loss rates of up to 17·10-6 MSun/yr were significantly higher than in intermediate-period single Miras and in agreement with longer-period O-rich AGB stars.Despite the nova outburst, HM Sge remained enshrouded in dust with no significant dust destruction. The existence of unperturbed dust shell suggests a small influence of the hot component and strong dust shielding from the UV flux. By the use of the CLOUDY code, we have showed that a high-density gas region can effectively stop most of the UV flux from the white dwarf and provide the observed dust shielding.
Probing the nature of cataclysmic variables via photometric studies on multiple timescales
NASA Astrophysics Data System (ADS)
Armstrong, Eve
I examine the structure and evolution of hydrogen- and helium-rich cataclysmic variables (CVs), via their periodic variability captured by long-term time series photometry. Studies to be discussed address one of two sets of question. One set pertains to helium CVs, which are poorly understood relative to their hydrogen-rich counterparts: What is the long-term evolution - in terms of orbital period (Porb) - of He CVs, and what does this imply about the nature of their secondaries? Two methods of investigation are employed: i) using systems with positive superhump and orbital period detections (Chapter 3) in order to chart the distribution of Porb versus time for He CVs (Chapter 4); ii) direct pulse timing of Porb in one system, via an 18-year baseline of photometry (Chapter 5). Results of the first study indicate that helium CVs are evolving toward longer Porb and have secondaries that are well described as degenerate objects. The pulse timing of one object (and the same measurement in two other He CVs) shows no evidence for Porb lengthening, and is consistent with Porb shortening driven by angular momentum loss via gravitational wave radiation. Technically, the two results are not inconsistent, as AM CVn is the only point on the distribution with a Porb timing. The apparent contradiction, however, illuminates our poor understanding of this class of CV: their routes to birth and the range of paths that a star can take following core hydrogen burning. The second set of studies pertains to signals associated with the accretion disc: Can a CV's accretion disc tilt with respect to the orbital plane? And what is the geometry and behavior of matter at various annuli in a tilted disc? To this end, I examine orbital sideband signals in AM CVn (Chapter 6) and simultaneous orbital sidebands and superorbital signals in two hydrogen CVs (Chapter 7). I also tabulate, from the literature, ten additional CVs with reliable detections of these signals (Chapter 7). All results indicate that the mechanism of tilt is at work in these objects.
Mansell, Gemma; Storheim, Kjersti; Løchting, Ida; Werner, Erik L; Grotle, Margreth
2017-12-01
Many interventions for the treatment of low back pain exist, but the mechanisms through which such treatments work are not always clear. This situation is especially true for biopsychosocial interventions that incorporate several different components and methods of delivery. The study objective was to examine the indirect effects of the Cognitive Patient Education (COPE) intervention via illness perceptions, back pain myths, and pain catastrophizing on disability outcome. This study was a secondary analysis of the COPE randomized controlled trial. Mediation analysis techniques were employed to examine the indirect effects of the COPE intervention via residualized change (baseline - posttreatment) in the 3 variables hypothesized to be targeted by the COPE intervention on posttreatment disability outcome. Pain intensity at baseline, pain duration, clinician type, and a treatment-mediator interaction term were controlled for in the analysis. Preliminary analyses confirmed that changes in pain catastrophizing and illness perceptions (not back pain myths) were related to both allocation to the intervention arm and posttreatment disability score. The treatment exerted statistically significant indirect effects via changes in illness perceptions and pain catastrophizing on posttreatment disability score (illness perceptions standardized indirect effect = 0.09 [95% CI = 0.03 to 0.16]; pain catastrophizing standardized indirect effect = 0.05 [95% CI = 0.01 to 0.12]). However, the inclusion of an interaction term led to the indirect effects being significantly reduced, with the effects no longer being statistically significant. This study presents a secondary analysis of variables not identified a priori as being potentially important treatment targets; other, unmeasured factors could also be important in explaining treatment effects. The finding that small indirect effects of the COPE intervention via changes in illness perceptions and pain catastrophizing on posttreatment disability could be estimated indicates that these variables may be viable treatment targets for biopsychosocial interventions; however, this finding must be viewed in light of the adjusted analyses, which showed that the indirect effects were significantly reduced through the inclusion of a treatment-mediator interaction term. © Crown copyright 2015
Subgrid-scale effects in compressible variable-density decaying turbulence
GS, Sidharth; Candler, Graham V.
2018-05-08
We present that many turbulent flows are characterized by complex scale interactions and vorticity generation caused by compressibility and variable-density effects. In the large-eddy simulation of variable-density flows, these processes manifest themselves as subgrid-scale (SGS) terms that interact with the resolved-scale flow. This paper studies the effect of the variable-density SGS terms and quantifies their relative importance. We consider the SGS terms appearing in the density-weighted Favre-filtered equations and in the unweighted Reynolds-filtered equations. The conventional form of the Reynolds-filtered momentum equation is complicated by a temporal SGS term; therefore, we derive a new form of the Reynolds-filtered governing equationsmore » that does not contain this term and has only double-correlation SGS terms. The new form of the filtered equations has terms that represent the SGS mass flux, pressure-gradient acceleration and velocity-dilatation correlation. To evaluate the dynamical significance of the variable-density SGS effects, we carry out direct numerical simulations of compressible decaying turbulence at a turbulent Mach number of 0.3. Two different initial thermodynamic conditions are investigated: homentropic and a thermally inhomogeneous gas with regions of differing densities. The simulated flow fields are explicitly filtered to evaluate the SGS terms. The importance of the variable-density SGS terms is quantified relative to the SGS specific stress, which is the only SGS term active in incompressible constant-density turbulence. It is found that while the variable-density SGS terms in the homentropic case are negligible, they are dynamically significant in the thermally inhomogeneous flows. Investigation of the variable-density SGS terms is therefore important, not only to develop variable-density closures but also to improve the understanding of scale interactions in variable-density flows.« less
Subgrid-scale effects in compressible variable-density decaying turbulence
DOE Office of Scientific and Technical Information (OSTI.GOV)
GS, Sidharth; Candler, Graham V.
We present that many turbulent flows are characterized by complex scale interactions and vorticity generation caused by compressibility and variable-density effects. In the large-eddy simulation of variable-density flows, these processes manifest themselves as subgrid-scale (SGS) terms that interact with the resolved-scale flow. This paper studies the effect of the variable-density SGS terms and quantifies their relative importance. We consider the SGS terms appearing in the density-weighted Favre-filtered equations and in the unweighted Reynolds-filtered equations. The conventional form of the Reynolds-filtered momentum equation is complicated by a temporal SGS term; therefore, we derive a new form of the Reynolds-filtered governing equationsmore » that does not contain this term and has only double-correlation SGS terms. The new form of the filtered equations has terms that represent the SGS mass flux, pressure-gradient acceleration and velocity-dilatation correlation. To evaluate the dynamical significance of the variable-density SGS effects, we carry out direct numerical simulations of compressible decaying turbulence at a turbulent Mach number of 0.3. Two different initial thermodynamic conditions are investigated: homentropic and a thermally inhomogeneous gas with regions of differing densities. The simulated flow fields are explicitly filtered to evaluate the SGS terms. The importance of the variable-density SGS terms is quantified relative to the SGS specific stress, which is the only SGS term active in incompressible constant-density turbulence. It is found that while the variable-density SGS terms in the homentropic case are negligible, they are dynamically significant in the thermally inhomogeneous flows. Investigation of the variable-density SGS terms is therefore important, not only to develop variable-density closures but also to improve the understanding of scale interactions in variable-density flows.« less
Arnold, L. Eugene; Hodgkins, Paul; Caci, Hervé; Kahle, Jennifer; Young, Susan
2015-01-01
Background Evaluation of treatments for attention-deficit/hyperactivity disorder (ADHD) previously focused on symptom control, but attention has shifted to functional outcomes. The effect of different ADHD treatment periods and modalities (pharmacological, non-pharmacological, and combination) on long-term outcomes needs to be more comprehensively understood. Methods A systematic search of 12 literature databases using Cochrane’s guidelines yielded 403 English-language peer-reviewed, primary studies reporting long-term outcomes (≥2 years). We evaluated relative effects of treatment modalities and durations and effect sizes of outcomes reported as statistically significantly improved with treatment. Results The highest proportion of improved outcomes was reported with combination treatment (83% of outcomes). Among significantly improved outcomes, the largest effect sizes were found for combination treatment. The greatest improvements were associated with academic, self-esteem, or social function outcomes. A majority of outcomes improved regardless of age of treatment initiation (60%–75%) or treatment duration (62%–72%). Studies with short treatment duration had shorter follow-up times (mean 3.2 years total study length) than those with longer treatment durations (mean 7.1 years total study length). Studies with follow-up times <3 years reported benefit with treatment for 93% of outcomes, whereas those with follow-up times ≥3 years reported treatment benefit for 57% of outcomes. Post-hoc analysis indicated that this result was related to the measurement of outcomes at longer periods (3.2 versus 0.4 years) after treatment cessation in studies with longer total study length. Conclusions While the majority of long-term outcomes of ADHD improve with all treatment modalities, the combination of pharmacological and non-pharmacological treatment was most consistently associated with improved long-term outcomes and large effect sizes. Older treatment initiation age or longer durations did not markedly affect proportion of improved outcomes reported, but measurement of outcomes long periods after treatment cessation may attenuate results. PMID:25714373
Awaiz, Aiman; Yunus, Rossita M; Khan, Shahjahan; Memon, Breda; Memon, Muhammed A
2017-06-01
Laparoscopic Heller myotomy (LHM) is the preferred surgical method for treating achalasia. However, peroral endoscopic myotomy (POEM) is providing good short-term results. The objective of this systematic review and meta-analysis was to compare the safety and efficacy of LHM and POEM. A search of PubMed, Cochrane database, Medline, Embase, Science Citation Index, and current contents for English-language articles comparing LHM and POEM between 2007 and 2016 was performed. Variables analyzed included prior endoscopic treatment, prior medical treatment, prior Heller myotomy, operative time, overall complications rate, postoperative gastroesophageal reflux disease (GERD), length of hospital stay, postoperative pain score, and long-term GERD. Seven trials consisting of 483 (LHM=250, POEM=233) patients were analyzed. Preoperative variables, for example, prior endoscopic treatment [odds ratio (OR), 1.32; 95% confidence interval (CI), 0.23-4.61; P=0.96], prior medical treatment [weighted mean difference (WMD), 1.22; 95% CI, 0.52-2.88; P=0.65], and prior Heller myotomy (WMD, 0.47; 95% CI, 0.13-1.67; P=0.25) were comparable. Operative time was 26.28 minutes, nonsignificantly longer for LHM (WMD, 26.28; 95% CI, -11.20 to 63.70; P=0.17). There was a comparable overall complication rate (OR, 1.25; 95% CI, 0.56-2.77; P=0.59), postoperative GERD rate (OR, 1.27; 95% CI, 0.70-2.30; P=0.44), length of hospital stay (WMD, 0.30; 95% CI, -0.24 to 0.85; P=0.28), postoperative pain score (WMD, -0.26; 95% CI, -1.58 to 1.06; P=0.70), and long-term GERD (WMD, 1.06; 95% CI, 0.27-4.1; P=0.08) for both procedures. There was a significantly higher short-term clinical treatment failure rate for LHM (OR, 9.82; 95% CI, 2.06-46.80; P<0.01). POEM compares favorably to LHM for achalasia treatment in short-term perioperative outcomes. However, there was a significantly higher clinical treatment failure rate for LHM on short-term postoperative follow-up. Presently long-term postoperative follow-up data for POEM beyond 1 year are unavailable and eagerly awaited.
Correlation Lengths for Estimating the Large-Scale Carbon and Heat Content of the Southern Ocean
NASA Astrophysics Data System (ADS)
Mazloff, M. R.; Cornuelle, B. D.; Gille, S. T.; Verdy, A.
2018-02-01
The spatial correlation scales of oceanic dissolved inorganic carbon, heat content, and carbon and heat exchanges with the atmosphere are estimated from a realistic numerical simulation of the Southern Ocean. Biases in the model are assessed by comparing the simulated sea surface height and temperature scales to those derived from optimally interpolated satellite measurements. While these products do not resolve all ocean scales, they are representative of the climate scale variability we aim to estimate. Results show that constraining the carbon and heat inventory between 35°S and 70°S on time-scales longer than 90 days requires approximately 100 optimally spaced measurement platforms: approximately one platform every 20° longitude by 6° latitude. Carbon flux has slightly longer zonal scales, and requires a coverage of approximately 30° by 6°. Heat flux has much longer scales, and thus a platform distribution of approximately 90° by 10° would be sufficient. Fluxes, however, have significant subseasonal variability. For all fields, and especially fluxes, sustained measurements in time are required to prevent aliasing of the eddy signals into the longer climate scale signals. Our results imply a minimum of 100 biogeochemical-Argo floats are required to monitor the Southern Ocean carbon and heat content and air-sea exchanges on time-scales longer than 90 days. However, an estimate of formal mapping error using the current Argo array implies that in practice even an array of 600 floats (a nominal float density of about 1 every 7° longitude by 3° latitude) will result in nonnegligible uncertainty in estimating climate signals.
18 CFR 806.31 - Term of approvals.
Code of Federal Regulations, 2010 CFR
2010-04-01
... approval issued under this part shall be no longer than 15 years or the anticipated life of the project... AND APPROVAL OF PROJECTS Terms and Conditions of Approval § 806.31 Term of approvals. (a) Approvals... approval of a project shall expire three years from the date of such approval if the withdrawal, diversion...
75 FR 47465 - Pymetrozine; Regulation Denying NRDC's Objections on Remand
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-06
... adverse effects are caused by either short-term (e.g., acute) or longer-term (e.g., chronic) pesticide... correspondingly levels of concern, for both short and long exposure periods as well as for the different routes of..., short-term, chronic, and cancer risks and EPA quantitatively assessed these risks in making its safety...
Framework for a U.S. Geological Survey Hydrologic Climate-Response Program in Maine
Hodgkins, Glenn A.; Lent, Robert M.; Dudley, Robert W.; Schalk, Charles W.
2009-01-01
This report presents a framework for a U.S. Geological Survey (USGS) hydrologic climate-response program designed to provide early warning of changes in the seasonal water cycle of Maine. Climate-related hydrologic changes on Maine's rivers and lakes in the winter and spring during the last century are well documented, and several river and lake variables have been shown to be sensitive to air-temperature changes. Monitoring of relevant hydrologic data would provide important baseline information against which future climate change can be measured. The framework of the hydrologic climate-response program presented here consists of four major parts: (1) identifying homogeneous climate-response regions; (2) identifying hydrologic components and key variables of those components that would be included in a hydrologic climate-response data network - as an example, streamflow has been identified as a primary component, with a key variable of streamflow being winter-spring streamflow timing; the data network would be created by maintaining existing USGS data-collection stations and establishing new ones to fill data gaps; (3) regularly updating historical trends of hydrologic data network variables; and (4) establishing basins for process-based studies. Components proposed for inclusion in the hydrologic climate-response data network have at least one key variable for which substantial historical data are available. The proposed components are streamflow, lake ice, river ice, snowpack, and groundwater. The proposed key variables of each component have extensive historical data at multiple sites and are expected to be responsive to climate change in the next few decades. These variables are also important for human water use and (or) ecosystem function. Maine would be divided into seven climate-response regions that follow major river-basin boundaries (basins subdivided to hydrologic units with 8-digit codes or larger) and have relatively homogeneous climates. Key hydrologic variables within each climate-response region would be analyzed regularly to maintain up-to-date analyses of year-to-year variability, decadal variability, and longer term trends. Finally, one basin in each climate-response region would be identified for process-based hydrologic and ecological studies.
NASA Astrophysics Data System (ADS)
Jurdana-Šepić, R.; Munari, U.; Antoniucci, S.; Giannini, T.; Lorenzetti, D.
2018-06-01
Context. Eruptive variables are young stars that show episodic variations of brightness: EXors/FUors variations are commonly associated with enhanced accretion outbursts occurring at intermittent cadence of months/years (EXors) and decades/centuries (FUors). Variations that can be ascribed to a variable extinction along their line of sight are instead classified as UXors. Aims: We aim at investigating the long-term photometric behaviour of three sources classified as eruptive variables. We present data from the archival plates of the Asiago Observatory relative to the fields where the targets are located. For the sake of completeness we have also analysed the Harvard plates of the same regions that cover a much longer historical period, albeit at a lower sensitivity, however we are only able to provide upper limits. Methods: A total of 273 Asiago plates were investigated, providing a total of more than 200 magnitudes for the three stars, which cover a period of about 34 yr between 1958 and 1991. We have compared our data with more recently collected literature data. Results: Our plates analysis of V2492 Cyg provides historical upper limits that seem not to be compatible with the level of the activity monitored during the last decade. Therefore, recently observed accretion phenomena could be associated with the outbursting episodes, more than repetitive obscuration. While a pure extinction does not seem the only mechanism responsible for the ASASSN-15qi fluctuations, it can account quite reasonably for the recent V350 Cep variations.
Multi-Proxy Reconstructions of Northeast Pacific Decadal Variability from Bivalve Mollusks and Trees
NASA Astrophysics Data System (ADS)
Black, B.; Griffin, D.
2017-12-01
Decadal-scale climate variability in the Northeast Pacific Ocean profoundly influences fisheries production, forest growth, wildfire, drought, and snowpack in western North America. However, there remains considerable and long-standing uncertainly in its behavior prior to AD 1900 and the extent to which 20th century dynamics are atypical in a multi-centennial context. Here, we target the leading EOF of SST in the northeastern Pacific (ARCSST) as an index of Pacific Decadal Variability, which has been dynamically linked to sea level pressure and unlike the Pacific Decadal Oscillation Index, retains a linear warming trend. The ARCSST reconstruction is generated from a broad network of target-sensitive North American tree-ring data standardized using signal-free detrending to preserve lower frequency signals common to the original data. In a preliminary analysis, the mean of the approximately 50 chronologies that significantly (p < 0.01) correlate to the target variable explain 60% of the variance in cool-season ARCSST. Reconstruction skill is independently verified by three marine bivalve (Pacific geoduck; Panopea generosa) chronologies, the mean of which accounts for over 50% of the reconstruction variance over the common 1870-1900 interval. The nested reconstruction spans over 500 years and indicates that i) PDV is dominated by pentadecadal cycles, ii) century-long quiescent periods can occur, iii) 20th century regime shifts are typical, but iv) late 20th century warming is atypical in the longer-term context. Moreover, the reconstruction closely tracks paleofisheries datasets, particularly northern anchovy (Engraulis mordax) abundance inferred from scale deposition rates in the Santa Barbara Basin.
Lin, Cheng-Chieh; Creath, Robert A; Rogers, Mark W
2016-01-01
In people with Parkinson disease (PD), difficulties with initiating stepping may be related to impairments of anticipatory postural adjustments (APAs). Increased variability in step length and step time has been observed in gait initiation in individuals with PD. In this study, we investigated whether the ability to generate consistent APAs during gait initiation is compromised in these individuals. Fifteen subjects with PD and 8 healthy control subjects were instructed to take rapid forward steps after a verbal cue. The changes in vertical force and ankle marker position were recorded via force platforms and a 3-dimensional motion capture system, respectively. Means, standard deviations, and coefficients of variation of both timing and magnitude of vertical force, as well as stepping variables, were calculated. During the postural phase of gait initiation the interval was longer and the force modulation was smaller in subjects with PD. Both the variability of timing and force modulation were larger in subjects with PD. Individuals with PD also had a longer time to complete the first step, but no significant differences were found for the variability of step time, length, and speed between groups. The increased variability of APAs during gait initiation in subjects with PD could affect posture-locomotion coupling, and lead to start hesitation, and even falls. Future studies are needed to investigate the effect of rehabilitation interventions on the variability of APAs during gait initiation in individuals with PD.Video abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A119).
Code of Federal Regulations, 2010 CFR
2010-04-01
... Estate and Gift Tax,” (Rev. 5-59). This publication is no longer available for purchase from the... (CONTINUED) ESTATE AND GIFT TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 Actuarial Tables Applicable... One and Two Lives” (12-70). These publications are no longer available for purchase from the...
Erik A. Lilleskov
2017-01-01
Fungal respiration contributes substantially to ecosystem respiration, yet its field temperature response is poorly characterized. I hypothesized that at diurnal time scales, temperature-respiration relationships would be better described by unimodal than exponential models, and at longer time scales both Q10 and mass-specific respiration at 10 °...
Is the Aquarius sea surface salinity variability representative?
NASA Astrophysics Data System (ADS)
Carton, J.; Grodsky, S.
2016-12-01
The leading mode of the Aquarius monthly anomalous sea surface salinity (SSS) is evaluated within the 50S-50N belt, where SSS retrieval accuracy is higher. This mode accounts for about 18% of the variance and resembles a pattern of the ENSO-induced anomalous rainfall. The leading mode of SSS variability deducted from a longer JAMSTEC analysis also accounts for about 17% of the variance and has very similar spatial pattern and almost a perfect correspondence of its temporal principal component to the SOI index. In that sense, the Aquarius SSS variability at low and middle latitudes is representative of SSS variability that may be obtained from longer records. This is explained by the fact that during the Aquarius period (2011-2015), the SOI index changed significantly from La Nina toward El Nino state, thus spanning a significant range of its characteristic variations. Multivariate EOF analysis of anomalous SSS and SST suggests that ENSO-induced shift in the tropical Pacific rainfall produces negatively correlated variability of temperature and salinity, which are expected if the anomalous surface flux (stronger rainfall coincident with less downward radiation) drives the system. But, anomalous SSS and SST are positively correlated in some areas including the northwestern Atlantic shelf (north of the Gulfstream) and the Pacific sector adjusting to the California peninsula. This positive correlation is indicative of an advection driven regime that is analyzed separately.
Liu, Wei-bo; Chen, Qiao-zhen; Yin, Hou-min; Zheng, Lei-lei; Yu, Shao-hua; Chen, Yi-ping; Li, Hui-chun
2011-11-01
To investigate the variability of event-related potentials P(300) and the relationship with memory function/psychopathology in patients with first-episode paranoid schizophrenia. Thirty patients with first-episode paranoid schizophrenia (patient group) and twenty health subjects (control group) were enrolled in the study. The auditory event-related potentials P₃₀₀ at the scalp electrodes Cz, Pz and Wechsler Memory Scale (WMS) were examined in both groups, Positive And Negative Syndrome Scale (PANSS) was evaluated in patient group. In comparison with control group, patients had longer latency of P₃₀₀ [(390.6 ± 47.6)ms at Cz and (393.3 ± 50.1)ms at Pz] (P<0.01), lower amplitude of P₃₀₀ [(7.7 ± 3.4) μV at Cz and (8.5 ± 3.9)μV at Pz] (P<0.05-0.01). The memory quotient (88.1 ± 10.0) scores and short-term memory, immediate memory in patient group were damaged significantly (P<0.05-0.01). In patient group, the latency of P300 was correlated positively with PANSS scores and negatively with WMS scores (P<0.05-0.01). First-episode paranoid schizophrenia has memory deficit, which can be evaluated comprehensively by P₃₀₀ and WMS. The longer latency of P₃₀₀ might be associated with the increased severity of first-episode paranoid schizophrenia.
Decadal trends in marine reserves reveal differential rates of change in direct and indirect effects
Babcock, R.C.; Shears, N.T.; Alcala, A.C.; Barrett, N.S.; Edgar, G.J.; Lafferty, K.D.; McClanahan, T.R.; Russ, G.R.
2010-01-01
Decadal-scale observations of marine reserves suggest that indirect effects on taxa that occur through cascading trophic interactions take longer to develop than direct effects on target species. Combining and analyzing a unique set of long-term time series of ecologic data in and out of fisheries closures from disparate regions, we found that the time to initial detection of direct effects on target species (+ or -SE) was 5.13 + or - 1.9 years, whereas initial detection of indirect effects on other taxa, which were often trait mediated, took significantly longer (13.1 + or - 2.0 years). Most target species showed initial direct effects, but their trajectories over time were highly variable. Many target species continued to increase, some leveled off, and others decreased. Decreases were due to natural fluctuations, fishing impacts from outside reserves, or indirect effects from target species at higher trophic levels. The average duration of stable periods for direct effects was 6.2 + or - 1.2 years, even in studies of more than 15 years. For indirect effects, stable periods averaged 9.1 + or - 1.6 years, although this was not significantly different from direct effects. Populations of directly targeted species were more stable in reserves than in fished areas, suggesting increased ecologic resilience. This is an important benefit of marine reserves with respect to their function as a tool for conservation and restoration.
The First Post-Kepler Brightness Dips of KIC 8462852
NASA Astrophysics Data System (ADS)
Boyajian, Tabetha. S.; Alonso, Roi; Ammerman, Alex; Armstrong, David; Asensio Ramos, A.; Barkaoui, K.; Beatty, Thomas G.; Benkhaldoun, Z.; Benni, Paul; Bentley, Rory O.; Berdyugin, Andrei; Berdyugina, Svetlana; Bergeron, Serge; Bieryla, Allyson; Blain, Michaela G.; Capetillo Blanco, Alicia; Bodman, Eva H. L.; Boucher, Anne; Bradley, Mark; Brincat, Stephen M.; Brink, Thomas G.; Briol, John; Brown, David J. A.; Budaj, J.; Burdanov, A.; Cale, B.; Aznar Carbo, Miguel; Castillo García, R.; Clark, Wendy J.; Clayton, Geoffrey C.; Clem, James L.; Coker, Phillip H.; Cook, Evan M.; Copperwheat, Chris M.; Curtis, J. L.; Cutri, R. M.; Cseh, B.; Cynamon, C. H.; Daniels, Alex J.; Davenport, James R. A.; Deeg, Hans J.; De Lorenzo, Roberto; de Jaeger, Thomas; Desrosiers, Jean-Bruno; Dolan, John; Dowhos, D. J.; Dubois, Franky; Durkee, R.; Dvorak, Shawn; Easley, Lynn; Edwards, N.; Ellis, Tyler G.; Erdelyi, Emery; Ertel, Steve; Farfán, Rafael. G.; Farihi, J.; Filippenko, Alexei V.; Foxell, Emma; Gandolfi, Davide; Garcia, Faustino; Giddens, F.; Gillon, M.; González-Carballo, Juan-Luis; González-Fernández, C.; González Hernández, J. I.; Graham, Keith A.; Greene, Kenton A.; Gregorio, J.; Hallakoun, Na’ama; Hanyecz, Ottó; Harp, G. R.; Henry, Gregory W.; Herrero, E.; Hildbold, Caleb F.; Hinzel, D.; Holgado, G.; Ignácz, Bernadett; Ilyin, Ilya; Ivanov, Valentin D.; Jehin, E.; Jermak, Helen E.; Johnston, Steve; Kafka, S.; Kalup, Csilla; Kardasis, Emmanuel; Kaspi, Shai; Kennedy, Grant M.; Kiefer, F.; Kielty, C. L.; Kessler, Dennis; Kiiskinen, H.; Killestein, T. L.; King, Ronald A.; Kollar, V.; Korhonen, H.; Kotnik, C.; Könyves-Tóth, Réka; Kriskovics, Levente; Krumm, Nathan; Krushinsky, Vadim; Kundra, E.; Lachapelle, Francois-Rene; LaCourse, D.; Lake, P.; Lam, Kristine; Lamb, Gavin P.; Lane, Dave; Lau, Marie Wingyee; Lewin, Pablo; Lintott, Chris; Lisse, Carey; Logie, Ludwig; Longeard, Nicolas; Lopez Villanueva, M.; Whit Ludington, E.; Mainzer, A.; Malo, Lison; Maloney, Chris; Mann, A.; Mantero, A.; Marengo, Massimo; Marchant, Jon; Martínez González, M. J.; Masiero, Joseph R.; Mauerhan, Jon C.; McCormac, James; McNeely, Aaron; Meng, Huan Y. A.; Miller, Mike; Molnar, Lawrence A.; Morales, J. C.; Morris, Brett M.; Muterspaugh, Matthew W.; Nespral, David; Nugent, C. R.; Nugent, Katherine M.; Odasso, A.; O’Keeffe, Derek; Oksanen, A.; O’Meara, John M.; Ordasi, András; Osborn, Hugh; Ott, John J.; Parks, J. R.; Rodriguez Perez, Diego; Petriew, Vance; Pickard, R.; Pál, András; Plavchan, P.; Pollacco, Don; Pozo Nuñez, F.; Pozuelos, F. J.; Rau, Steve; Redfield, Seth; Relles, Howard; Ribas, Ignasi; Richards, Jon; Saario, Joonas L. O.; Safron, Emily J.; Sallai, J. Martin; Sárneczky, Krisztián; Schaefer, Bradley E.; Schumer, Clea F.; Schwartzendruber, Madison; Siegel, Michael H.; Siemion, Andrew P. V.; Simmons, Brooke D.; Simon, Joshua D.; Simón-Díaz, S.; Sitko, Michael L.; Socas-Navarro, Hector; Sódor, Á.; Starkey, Donn; Steele, Iain A.; Stone, Geoff; Strassmeier, Klaus G.; Street, R. A.; Sullivan, Tricia; Suomela, J.; Swift, J. J.; Szabó, Gyula M.; Szabó, Róbert; Szakáts, Róbert; Szalai, Tamás; Tanner, Angelle M.; Toledo-Padrón, B.; Tordai, Tamás; Triaud, Amaury H. M. J.; Turner, Jake D.; Ulowetz, Joseph H.; Urbanik, Marian; Vanaverbeke, Siegfried; Vanderburg, Andrew; Vida, Krisztián; Vietje, Brad P.; Vinkó, József; von Braun, K.; Waagen, Elizabeth O.; Walsh, Dan; Watson, Christopher A.; Weir, R. C.; Wenzel, Klaus; Westendorp Plaza, C.; Williamson, Michael W.; Wright, Jason T.; Wyatt, M. C.; Zheng, WeiKang; Zsidi, Gabriella
2018-01-01
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%–2.5% dips, named “Elsie,” “Celeste,” “Skara Brae,” and “Angkor,” which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale ≪1 μm, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term “secular” dimming, which may be caused by independent processes, or probe different regimes of a single process.
Sonder, Judith M; Balk, Lisanne J; Bosma, Libertje V A E; Polman, Chris H; Uitdehaag, Bernard M J
2014-10-01
Patient-reported outcome scales (PROs) are useful in monitoring changes in multiple sclerosis (MS) over time. Although these scales are reliable and valid measures in longitudinal studies in MS patients, it is unknown what the impact is when obtaining longitudinal data from proxies. The objective of this paper is to compare longitudinal changes in patient and proxy responses on PROs assessing physical impact of MS and walking ability. In a prospective observational study, data on the Multiple Sclerosis Impact Scale (MSIS-29 physical) and Multiple Sclerosis Walking Scale (MSWS-12) were obtained from 137 patient-proxy couples at baseline and at two-year follow-up. Demographic and disease-related variables explaining agreement or disagreement between patients and proxies were investigated using linear regression analyses. Full agreement was found in 56% (MSIS) and 62% (MSWS) of the patient-proxy couples. Complete disagreement was very rare for both scales (2% MSIS, 5% MSWS). When patients were more positive than proxies, a higher age, longer disease duration, longer patient-proxy relationship and increased levels of depression, anxiety and caregiver burden in proxies were observed. In the majority of the patient-proxy couples there was agreement. Proxies can serve as a valuable source of information, but caution remains essential when using scores from proxies. © The Author(s), 2014.
Babcock, R C; Shears, N T; Alcala, A C; Barrett, N S; Edgar, G J; Lafferty, K D; McClanahan, T R; Russ, G R
2010-10-26
Decadal-scale observations of marine reserves suggest that indirect effects on taxa that occur through cascading trophic interactions take longer to develop than direct effects on target species. Combining and analyzing a unique set of long-term time series of ecologic data in and out of fisheries closures from disparate regions, we found that the time to initial detection of direct effects on target species (±SE) was 5.13 ± 1.9 years, whereas initial detection of indirect effects on other taxa, which were often trait mediated, took significantly longer (13.1 ± 2.0 years). Most target species showed initial direct effects, but their trajectories over time were highly variable. Many target species continued to increase, some leveled off, and others decreased. Decreases were due to natural fluctuations, fishing impacts from outside reserves, or indirect effects from target species at higher trophic levels. The average duration of stable periods for direct effects was 6.2 ± 1.2 years, even in studies of more than 15 years. For indirect effects, stable periods averaged 9.1 ± 1.6 years, although this was not significantly different from direct effects. Populations of directly targeted species were more stable in reserves than in fished areas, suggesting increased ecologic resilience. This is an important benefit of marine reserves with respect to their function as a tool for conservation and restoration.