Science.gov

Sample records for multiple temporal levels

  1. Temporal stability of multiple-cell vortices

    NASA Technical Reports Server (NTRS)

    Khorrami, M. R.; Grosch, C. E.

    1989-01-01

    The temporal stability of multiple cell vortices is studied with a staggered Chebyshev spectral collocation technique. It is shown that cell multiplicity in the vortex core has a drastic effect on the stability characteristics. While validating the spectral collocation algorithm, two new viscous modes of instability for Batchelor's (1964) vortex were found. These modes are discussed in detail.

  2. Hierarchical and multiple hand action representation using temporal postural synergies.

    PubMed

    Tessitore, G; Sinigaglia, C; Prevete, R

    2013-03-01

    The notion of synergy enables one to provide simplified descriptions of hand actions. It has been used in a number of different meanings ranging from kinematic and dynamic synergies to postural and temporal postural synergies. However, relatively little is known about how representing an action by synergies might take into account the possibility to have a hierarchical and multiple action representation. This is a key aspect for action representation as it has been characterized by action theorists and cognitive neuroscientists. Thus, the aim of the present paper is to investigate whether and to what extent a hierarchical and multiple action representation can be obtained by a synergy approach. To this purpose, we took advantage of representing hand action as a linear combination of temporal postural synergies (TPSs), but on the assumption that TPSs have a tree-structured organization. In a tree-structured organization, a hand action representation can involve a TPS only if the ancestors of the synergy in the tree are themselves involved in the action representation. The results showed that this organization is enough to force a multiple representation of hand actions in terms of synergies which are hierarchically organized.

  3. Vitamin D Levels Predict Multiple Sclerosis Progression

    MedlinePlus

    ... Research Matters NIH Research Matters February 3, 2014 Vitamin D Levels Predict Multiple Sclerosis Progression Among people ... sclerosis (MS), those with higher blood levels of vitamin D had better outcomes during 5 years of ...

  4. Pattern-level temporal difference learning, data fusion, and chess

    NASA Astrophysics Data System (ADS)

    Levinson, Robert; Weber, Ryan J.

    2000-04-01

    Our research group is using chess as a vehicle for studying the fusion of adaptation, multiple representation, and search technologies for real-time decision making. Chess systems like Deep Blue have achieved Grandmaster chess play with a brute-force search of the game tree and human- supplied information, like piece-values and opening books. However, subtle aspects of chess, including positional features and advanced concepts, are not capable of being represented or processed efficiently with the standard method. Since 1989, Morph I-III have exhibited more autonomy and learning ability than traditional chess programs in `adaptive pattern-oriented chess'. Like its predecessors, Morph IV is a reinforcement learner, but it also uses a new technique we call pattern-level TD and Q-learning to mathematically map the state space and effectively learn to classify situations. Its three knowledge sources include two traditional ones: material and a piece-square table, and a new method called Distance. These are combined using a simple genetic algorithm and a decision tree. This paper shows the effectiveness of fusing knowledge to replace search in real-time situations, since an agent which combines all sources is capable of consistently beating an agent which employs any of the individual knowledge sources. Surprisingly, the pattern-level TD agent is slightly superior to the pattern-level Q-learning agent, despite the fact that the Q-learning agent updates more Q-values on each temporal step.

  5. A study of the temporal stability of multiple cell vortices

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.

    1989-01-01

    The effect of initial mean velocity field on the stability characteristics of longitudinal vortices is documented in detail. The temporal stability of isolated multiple cell vortices is considered. The types of vortices studied include single cell as well as two and three cell vortices. It is shown that cell multiplicity in the vortex core has drastic effects on the stability characteristics. On the basis of numerical calculations, it is concluded that the growth rates of instabilities in multiple cell vortices are substantially larger (two to threefold increases are observed) than those of a single cell vortex. It is also determined that there is a substantial increase in the effective range of axial and azimuthal wavenumbers where instabilities are present. But most importantly, there is the appearance of a variety of viscous modes of instability. In the case of vortices, these latter instabilities which highlight the importance of viscous forces have never been reported before. These effects are discussed in detail for the case of a two cell vortex.

  6. An interval logic for higher-level temporal reasoning

    NASA Technical Reports Server (NTRS)

    Schwartz, R. L.; Melliar-Smith, P. M.; Vogt, F. H.; Plaisted, D. A.

    1983-01-01

    Prior work explored temporal logics, based on classical modal logics, as a framework for specifying and reasoning about concurrent programs, distributed systems, and communications protocols, and reported on efforts using temporal reasoning primitives to express very high level abstract requirements that a program or system is to satisfy. Based on experience with those primitives, this report describes an Interval Logic that is more suitable for expressing such higher level temporal properties. The report provides a formal semantics for the Interval Logic, and several examples of its use. A description of decision procedures for the logic is also included.

  7. Estimation of dynamic functional connectivity using Multiplication of Temporal Derivatives.

    PubMed

    Shine, James M; Koyejo, Oluwasanmi; Bell, Peter T; Gorgolewski, Krzysztof J; Gilat, Moran; Poldrack, Russell A

    2015-11-15

    Functional connectivity provides an informative and powerful framework for exploring brain organization. Despite this, few statistical methods are available for the accurate estimation of dynamic changes in functional network architecture. To date, the majority of existing statistical techniques have assumed that connectivity structure is stationary, which is in direct contrast to emerging data that suggests that the strength of connectivity between regions is variable over time. Therefore, the development of statistical methods that enable exploration of dynamic changes in functional connectivity is currently of great importance to the neuroscience community. In this paper, we introduce the 'Multiplication of Temporal Derivatives' (MTD) and then demonstrate the utility of this metric to: (i) detect dynamic changes in connectivity using data from a novel state-switching simulation; (ii) accurately estimate graph structure in a previously-described 'ground-truth' simulated dataset; and (iii) identify task-driven alterations in functional connectivity. We show that the MTD is more sensitive than existing sliding-window methods in detecting dynamic alterations in connectivity structure across a range of correlation strengths and window lengths in simulated data. In addition to the temporal precision offered by MTD, we demonstrate that the metric is also able to accurately estimate stationary network structure in both simulated and real task-based data, suggesting that the method may be used to identify dynamic changes in network structure as they evolve through time.

  8. Spatio-temporal Linear Stability Analysis of Multiple Reacting Wakes

    NASA Astrophysics Data System (ADS)

    Kunnumpuram Sebastian, Jacob; Emerson, Benjamin; Lieuwen, Tim

    2016-11-01

    Hydrodynamic stability of reacting shear flows plays a key role in controlling a variety of combustor behaviors, such as combustion instability, mixing and entrainment, and blowoff. A significant literature exists on the hydrodynamics of single bluff body flows, but not the multi-bluff body flows that are found in applications. The objective of this work was to compare the spatio-temporal stability of multiple reacting wakes and single reacting wakes, within the framework of linear stability theory. Spatio-temporal stability analyses are conducted on model velocity and density profiles, with key parameters being the density ratio across the flame, bluff body spacing, dimensionless shear, and asymmetry parameters (if the two wakes are dissimilar). The introduction of the additional bluff body can exert both a stabilizing and destabilizing effect on the combined two-wake system, depending on the spatial separation between the bluff bodies. Furthermore, while the most rapidly amplified mode of the single wake mode is the sinuous (asymmetric) one, in the two wake system, the most rapidly amplified mode can be either sinuous or varicose (symmetric), also depending on spatial separation.

  9. Temporal scaling behavior of sea-level change in Hong Kong - Multifractal temporally weighted detrended fluctuation analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanzhi; Ge, Erjia

    2013-01-01

    The rise in global sea levels has been recognized by many scientists as an important global research issue. The process of sea-level change has demonstrated a complex scaling behavior in space and time. Large numbers of tide gauge stations have been built to measure sea-level change in the North Pacific Ocean, Indian Ocean, North Atlantic Ocean, and Antarctic Ocean. Extensive studies have been devoted to exploring sea-level variation in Asia concerning the Bohai Gulf (China), the Yellow Sea (China), the Mekong Delta (Thailand), and Singapore. Hong Kong, however, a mega city with a population of over 7 million situated in the mouth of the Pear River Estuary in the west and the South China Sea in the east, has yet to be studied, particularly in terms of the temporal scaling behavior of sea-level change. This article presents an approach to studying the temporal scaling behavior of sea-level change over multiple time scales by analyzing the time series of sea-level change in Tai Po Kou, Tsim Bei Tsui, and Quarry Bay from the periods of 1964-2010, 1974-2010, and 1986-2010, respectively. The detection of long-range correlation and multi-fractality of sea-level change seeks answers to the following questions: (1) Is the current sea-level rise associated with and responsible for the next rise over time? (2) Does the sea-level rise have specific temporal patterns manifested by multi-scaling behaviors? and (3) Is the sea-level rise is temporally heterogeneous in the different parts of Hong Kong? Multi-fractal temporally weighted de-trended fluctuation analysis (MF-TWDFA), an extension of multi-fractal de-trended fluctuation analysis (MF-DFA), has been applied in this study to identify long-range correlation and multi-scaling behavior of the sea-level rise in Hong Kong. The experimental results show that the sea-level rise is long-range correlated and multi-fractal. The temporal patterns are heterogeneous over space. This finding implies that mechanisms associated with the

  10. Influence of Temporal Context on Value in the Multiple-Chains and Successive-Encounters Procedures

    ERIC Educational Resources Information Center

    O'Daly, Matthew; Angulo, Samuel; Gipson, Cassandra; Fantino, Edmund

    2006-01-01

    This set of studies explored the influence of temporal context across multiple-chain and multiple-successive-encounters procedures. Following training with different temporal contexts, the value of stimuli sharing similar reinforcement schedules was assessed by presenting these stimuli in concurrent probes. The results for the multiple-chain…

  11. Temporal stability of multiple response systems to 7.5% carbon dioxide challenge.

    PubMed

    Roberson-Nay, Roxann; Gorlin, Eugenia I; Beadel, Jessica R; Cash, Therese; Vrana, Scott; Teachman, Bethany A

    2017-03-01

    Self-reported anxiety, and potentially physiological response, to maintained inhalation of carbon dioxide (CO2) enriched air shows promise as a putative marker of panic reactivity and vulnerability. Temporal stability of response systems during low-dose, steady-state CO2 breathing challenge is lacking. Outcomes on multiple levels were measured two times, one week apart, in 93 individuals. Stability was highest during the CO2 breathing phase compared to pre-CO2 and recovery phases, with anxiety ratings, respiratory rate, skin conductance level, and heart rate demonstrating good to excellent temporal stability (ICCs≥0.71). Cognitive symptoms tied to panic were somewhat less stable (ICC=0.58) than physical symptoms (ICC=0.74) during CO2 breathing. Escape/avoidance behaviors and DSM-5 panic attacks were not stable. Large effect sizes between task phases also were observed. Overall, results suggest good-excellent levels of temporal stability for multiple outcomes during respiratory stimulation via 7.5% CO2.

  12. The temporal structure of pollution levels in developed cities.

    PubMed

    Barrigón Morillas, Juan Miguel; Ortiz-Caraballo, Carmen; Prieto Gajardo, Carlos

    2015-06-01

    Currently, the need for mobility can cause significant pollution levels in cities, with important effects on health and quality of life. Any approach to the study of urban pollution and its effects requires an analysis of spatial distribution and temporal variability. It is a crucial dilemma to obtain proven methodologies that allow an increase in the quality of the prediction and the saving of resources in the spatial and temporal sampling. This work proposes a new analytical methodology in the study of temporal structure. As a result, a model for estimating annual levels of urban traffic noise was proposed. The average errors are less than one decibel in all acoustics indicators. A new working methodology of urban noise has begun. Additionally, a general application can be found for the study of the impacts of pollution associated with traffic, with implications for urban design and possibly in economic and sociological aspects.

  13. TEMPORAL CHANGE IN FOREST FRAGMENTATION AT MULTIPLE SCALES

    EPA Science Inventory

    Previous studies of temporal changes in fragmentation have focused almost exclusively on patch and edge statistics, which might not detect changes in the spatial scale at which forest occurs in or dominates the landscape. We used temporal land-cover data for the Chesapeake Bay r...

  14. Multiple Stability of a Sparsely Encoded Attractor Neural Network Model for the Inferior Temporal Cortex

    NASA Astrophysics Data System (ADS)

    Kimoto, Tomoyuki; Uezu, Tatsuya; Okada, Masato

    2008-12-01

    We study a neural network model for the inferior temporal cortex, in terms of finite memory loading and sparse coding. We show that an uncorrelated Hopfield-type attractor and some correlated attractors have multiple stability, and examine the retrieval dynamics for these attractors when the initial state is set to a noise-degraded memory pattern. Then, we show that there is a critical initial overlap: that is, the system converges to the correlated attractor when the noise level is large, and otherwise to the Hopfield-type attractor. Furthermore, we study the time course of the correlation between the correlated attractors in the retrieval dynamics. On the basis of these theoretical results, we resolve the controversy regarding previous physiologic experimental findings regarding neuron properties in the inferior temporal cortex and propose a new experimental paradigm.

  15. Decoding Multiple Sound Categories in the Human Temporal Cortex Using High Resolution fMRI

    PubMed Central

    Zhang, Fengqing; Wang, Ji-Ping; Kim, Jieun; Parrish, Todd; Wong, Patrick C. M.

    2015-01-01

    Perception of sound categories is an important aspect of auditory perception. The extent to which the brain’s representation of sound categories is encoded in specialized subregions or distributed across the auditory cortex remains unclear. Recent studies using multivariate pattern analysis (MVPA) of brain activations have provided important insights into how the brain decodes perceptual information. In the large existing literature on brain decoding using MVPA methods, relatively few studies have been conducted on multi-class categorization in the auditory domain. Here, we investigated the representation and processing of auditory categories within the human temporal cortex using high resolution fMRI and MVPA methods. More importantly, we considered decoding multiple sound categories simultaneously through multi-class support vector machine-recursive feature elimination (MSVM-RFE) as our MVPA tool. Results show that for all classifications the model MSVM-RFE was able to learn the functional relation between the multiple sound categories and the corresponding evoked spatial patterns and classify the unlabeled sound-evoked patterns significantly above chance. This indicates the feasibility of decoding multiple sound categories not only within but across subjects. However, the across-subject variation affects classification performance more than the within-subject variation, as the across-subject analysis has significantly lower classification accuracies. Sound category-selective brain maps were identified based on multi-class classification and revealed distributed patterns of brain activity in the superior temporal gyrus and the middle temporal gyrus. This is in accordance with previous studies, indicating that information in the spatially distributed patterns may reflect a more abstract perceptual level of representation of sound categories. Further, we show that the across-subject classification performance can be significantly improved by averaging the f

  16. Decoding multiple sound categories in the human temporal cortex using high resolution fMRI.

    PubMed

    Zhang, Fengqing; Wang, Ji-Ping; Kim, Jieun; Parrish, Todd; Wong, Patrick C M

    2015-01-01

    Perception of sound categories is an important aspect of auditory perception. The extent to which the brain's representation of sound categories is encoded in specialized subregions or distributed across the auditory cortex remains unclear. Recent studies using multivariate pattern analysis (MVPA) of brain activations have provided important insights into how the brain decodes perceptual information. In the large existing literature on brain decoding using MVPA methods, relatively few studies have been conducted on multi-class categorization in the auditory domain. Here, we investigated the representation and processing of auditory categories within the human temporal cortex using high resolution fMRI and MVPA methods. More importantly, we considered decoding multiple sound categories simultaneously through multi-class support vector machine-recursive feature elimination (MSVM-RFE) as our MVPA tool. Results show that for all classifications the model MSVM-RFE was able to learn the functional relation between the multiple sound categories and the corresponding evoked spatial patterns and classify the unlabeled sound-evoked patterns significantly above chance. This indicates the feasibility of decoding multiple sound categories not only within but across subjects. However, the across-subject variation affects classification performance more than the within-subject variation, as the across-subject analysis has significantly lower classification accuracies. Sound category-selective brain maps were identified based on multi-class classification and revealed distributed patterns of brain activity in the superior temporal gyrus and the middle temporal gyrus. This is in accordance with previous studies, indicating that information in the spatially distributed patterns may reflect a more abstract perceptual level of representation of sound categories. Further, we show that the across-subject classification performance can be significantly improved by averaging the f

  17. Spatial and Temporal Dynamics of Pacific Oyster Hemolymph Microbiota across Multiple Scales

    PubMed Central

    Lokmer, Ana; Goedknegt, M. Anouk; Thieltges, David W.; Fiorentino, Dario; Kuenzel, Sven; Baines, John F.; Wegner, K. Mathias

    2016-01-01

    Unveiling the factors and processes that shape the dynamics of host associated microbial communities (microbiota) under natural conditions is an important part of understanding and predicting an organism's response to a changing environment. The microbiota is shaped by host (i.e., genetic) factors as well as by the biotic and abiotic environment. Studying natural variation of microbial community composition in multiple host genetic backgrounds across spatial as well as temporal scales represents a means to untangle this complex interplay. Here, we combined a spatially-stratified with a longitudinal sampling scheme within differentiated host genetic backgrounds by reciprocally transplanting Pacific oysters between two sites in the Wadden Sea (Sylt and Texel). To further differentiate contingent site from host genetic effects, we repeatedly sampled the same individuals over a summer season to examine structure, diversity and dynamics of individual hemolymph microbiota following experimental removal of resident microbiota by antibiotic treatment. While a large proportion of microbiome variation could be attributed to immediate environmental conditions, we observed persistent effects of antibiotic treatment and translocation suggesting that hemolymph microbial community dynamics is subject to within-microbiome interactions and host population specific factors. In addition, the analysis of spatial variation revealed that the within-site microenvironmental heterogeneity resulted in high small-scale variability, as opposed to large-scale (between-site) stability. Similarly, considerable within-individual temporal variability was in contrast with the overall temporal stability at the site level. Overall, our longitudinal, spatially-stratified sampling design revealed that variation in hemolymph microbiota is strongly influenced by site and immediate environmental conditions, whereas internal microbiome dynamics and oyster-related factors add to their long-term stability

  18. Temporal scaling of groundwater level fluctuations near a stream

    USGS Publications Warehouse

    Schilling, K.E.; Zhang, Y.-K.

    2012-01-01

    Temporal scaling in stream discharge and hydraulic heads in riparian wells was evaluated to determine the feasibility of using spectral analysis to identify potential surface and groundwater interaction. In floodplains where groundwater levels respond rapidly to precipitation recharge, potential interaction is established if the hydraulic head (h) spectrum of riparian groundwater has a power spectral density similar to stream discharge (Q), exhibiting a characteristic breakpoint between high and low frequencies. At a field site in Walnut Creek watershed in central Iowa, spectral analysis of h in wells located 1 m from the channel edge showed a breakpoint in scaling very similar to the spectrum of Q (~20 h), whereas h in wells located 20 and 40 m from the channel showed temporal scaling from 1 to 10,000 h without a well-defined breakpoint. The spectral exponent (??) in the riparian zone decreased systematically from the channel into the floodplain as groundwater levels were increasingly dominated by white noise groundwater recharge. The scaling pattern of hydraulic head was not affected by land cover type, although the number of analyses was limited and site conditions were variable among sites. Spectral analysis would not replace quantitative tracer or modeling studies, but the method may provide a simple means of confirming potential interaction at some sites. ?? 2011, The Author(s). Ground Water ?? 2011, National Ground Water Association.

  19. Cellular superresolved imaging of multiple markers using temporally flickering nanoparticles

    PubMed Central

    Ilovitsh, Tali; Danan, Yossef; Meir, Rinat; Meiri, Amihai; Zalevsky, Zeev

    2015-01-01

    In this paper we present a technique aimed for simultaneous detection of multiple types of gold nanoparticles (GNPs) within a biological sample, using lock-in detection. We image the sample using a number of modulated laser beams that correspond to the number of GNP species that label a given sample. The final image where the GNPs are spatially separated is obtained computationally. The proposed method enables the simultaneous superresolved imaging of different areas of interest within biological sample and also the spatial separation of GNPs at sub-diffraction distances, making it a useful tool in the study of intracellular trafficking pathways in living cells. PMID:26020693

  20. Temporal variations in Global Seismic Stations ambient noise power levels

    USGS Publications Warehouse

    Ringler, A.T.; Gee, L.S.; Hutt, C.R.; McNamara, D.E.

    2010-01-01

    Recent concerns about time-dependent response changes in broadband seismometers have motivated the need for methods to monitor sensor health at Global Seismographic Network (GSN) stations. We present two new methods for monitoring temporal changes in data quality and instrument response transfer functions that are independent of Earth seismic velocity and attenuation models by comparing power levels against different baseline values. Our methods can resolve changes in both horizontal and vertical components in a broad range of periods (∼0.05 to 1,000 seconds) in near real time. In this report, we compare our methods with existing techniques and demonstrate how to resolve instrument response changes in long-period data (>100 seconds) as well as in the microseism bands (5 to 20 seconds).

  1. Temporal laser pulse manipulation using multiple optical ring-cavities

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet (Inventor); Kojima, Jun (Inventor)

    2010-01-01

    An optical pulse stretcher and a mathematical algorithm for the detailed calculation of its design and performance is disclosed. The optical pulse stretcher has a plurality of optical cavities, having multiple optical reflectors such that an optical path length in each of the optical cavities is different. The optical pulse stretcher also has a plurality of beam splitters, each of which intercepts a portion of an input optical beam and diverts the portion into one of the plurality of optical cavities. The input optical beam is stretched and a power of an output beam is reduced after passing through the optical pulse stretcher and the placement of the plurality of optical cavities and beam splitters is optimized through a model that takes into account optical beam divergence and alignment in the pluralities of the optical cavities. The optical pulse stretcher system can also function as a high-repetition-rate (MHz) laser pulse generator, making it suitable for use as a stroboscopic light source for high speed ballistic projectile imaging studies, or it can be used for high speed flow diagnostics using a laser light sheet with digital particle imaging velocimetry. The optical pulse stretcher system can also be implemented using fiber optic components to realize a rugged and compact optical system that is alignment free and easy to use.

  2. Endoscopic facelift of the frontal and temporal areas in multiple planes

    PubMed Central

    Hu, Xiaogen; Ma, Haihuan; Xue, Zhiqiang; Qi, Huijie; Chen, Bo

    2017-01-01

    INTRODUCTION The detachment planes used in endoscopic facelifts play an important role in determining the results of facial rejuvenation. In this study, we introduced the use of multiple detachment planes for endoscopic facelifts of the frontal and temporal areas, and examined its outcome. METHODS This study included 47 patients (38 female, 9 male) who requested frontal and temporal facelifts from January 2009 to January 2014. The technique of dissection in multiple planes was used for all 47 patients. In this technique, the frontal dissection was first carried out in the subgaleal plane, before being changed to the subperiosteal plane about 2 cm above the eyebrow line. Temporal dissection was carried out in both the subcutaneous and subgaleal planes. After detachment, frontal and temporal fixations were achieved using nonabsorbable sutures, and the incisions were closed. During follow-up (ranging from 6–24 months after surgery), the patients were shown their pre- and postoperative images, and asked to rate their satisfaction with the procedure. Complications encountered were documented. RESULTS All 47 patients had complete recovery without any serious complications. The patient satisfaction rate was 93.6%. Minor complications included dimpling at the suture site, asymmetry, overcorrection, transitory paralysis, late oedema, haematoma, infection, scarring and hair loss. These complications resolved spontaneously and were negligible after complete recovery. CONCLUSION Dissection in multiple planes is valuable in frontal and temporal endoscopic facelifts. It may be worthwhile to introduce the use of this technique in frontal and temporal facelifts, as it may lead to improved outcomes. PMID:26891744

  3. Assessing hydrological alterations at multiple temporal scales: Adige River, Italy

    NASA Astrophysics Data System (ADS)

    Zolezzi, G.; Bellin, A.; Bruno, M. C.; Maiolini, B.; Siviglia, A.

    2009-12-01

    Hydrological alteration is one of the major threats to the integrity and functioning of riverine ecosystems. We propose to analyze such alterations by means of three approaches: the well-established range of variability approach (RVA), wavelet transform analysis (WT), and a combination of the two. This allows us to separate the most relevant scales of variability and to detect their alteration independently; such information cannot be provided by purely statistical methods like RVA. We show the advantages of this multiple approach through the analysis of two streamflow data sets of the Adige River at Trento, northeastern Italy: a daily streamflow record spanning from 1923 to 2006, and a record of instantaneous measurements with time step of 15 min from 2002 to 2006. Results suggest that starting from the 1960s, after the construction of the reservoirs currently in operation, a progressive flattening occurred in the hydrograph, which attenuated the amplitude of seasonal variations. This negative tendency worsened in the last few years, possibly as an effect of a reduction in winter snowfall. Wavelet analysis shows that hydroelectric production caused the high-frequency components of the signal to increase in amplitude and number, with fairly regular weekly and daily oscillations and sharp transitions. The whole spectrum of low flows is significantly altered. This alteration of the natural flow has adverse consequences on the ecological integrity of the ecosystem. Use of the range of variability approach, the wavelet transform analysis, and a new methodology which integrates both allows a better separation between natural and human-induced effects at ecologically relevant scales of variability, thereby identifying changes and trends due to hydropower management.

  4. Spatio-temporal variation in European starling reproductive success at multiple small spatial scales.

    PubMed

    Brickhill, Daisy; Evans, Peter Gh; Reid, Jane M

    2015-08-01

    Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics.

  5. Spatio-temporal variation in European starling reproductive success at multiple small spatial scales

    PubMed Central

    Brickhill, Daisy; Evans, Peter GH; Reid, Jane M

    2015-01-01

    Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics. PMID:26380670

  6. Multiple Intelligence Levels of Physical Education and Sports School Students

    ERIC Educational Resources Information Center

    Ekici, Summani

    2011-01-01

    The purpose of this research is to analyze the multiple intelligence levels of academies of physical education and sports students according to some demographic factors. To obtain data about multiple intelligence levels in the research, the multiple intelligence inventory, developed by Ozden (2003), was applied to a total of 1.199 students, of…

  7. Spatial and temporal variability of late Holocene sea-level changes in the North Atlantic (Invited)

    NASA Astrophysics Data System (ADS)

    Kemp, A.; Kopp, R. E.; Horton, B.; Cahill, N.

    2013-12-01

    Proxy sea-level reconstructions spanning the last ~2000 years capture multiple phases of climate and sea level behavior for model calibration, provide a pre-anthropogenic background against which to compare recent trends, and characterize patterns of natural spatial and temporal variability. In the western North Atlantic basin, salt-marsh sediment is an archive for reconstructing sea level with the decimeter and multi-decadal resolution necessary to characterize subtle changes. New and existing salt-marsh reconstructions from northern Florida, North Carolina, New Jersey, Connecticut, and Massachusetts provide a dataset for investigating spatial and temporal sea-level variability during the late Holocene. The reconstructions were developed using foraminifera, plants, and bulk sediment δ13C values as sea-level proxies. The age of sediment deposition was estimated from composite chronologies of radiocarbon and chronohorizons of regional pollution and land-use change that were combined in age depth models. We used a spatio-temporal Gaussian process model to identify and characterize persistent phases of sea level behavior during the late Holocene in the western North Atlantic Ocean. The results indicate an acceleration in global mean sea level from the early 19th century through the early 20th century. The rate of sea-level rise increased significantly in the late 19th century. The timing and magnitude of this rise varied among sites even after accounting for differences in glacio-isostatic adjustment. Sea level in North Carolina rose faster than in New Jersey sea-level during the Medieval Climate Optimum, while sea level in New Jersey rose faster during the Little Ice Age. Spatially variable sea-level rise on the Atlantic coast of North America can be caused by dynamic oceanographic processes and/or melting of the Greenland Ice Sheet. Our analysis suggests that plausible levels of meltwater input from Greenland would be inadequate to explain the reconstructed pattern

  8. Factors controlling spatial and temporal patterns of multiple pesticide compounds in groundwater (Hesbaye chalk aquifer, Belgium).

    PubMed

    Hakoun, Vivien; Orban, Philippe; Dassargues, Alain; Brouyère, Serge

    2017-04-01

    Factors governing spatial and temporal patterns of pesticide compounds (pesticides and metabolites) concentrations in chalk aquifers remain unclear due to complex flow processes and multiple sources. To uncover which factors govern pesticide compound concentrations in a chalk aquifer, we develop a methodology based on time series analyses, uni- and multivariate statistics accounting for concentrations below detection limits. The methodology is applied to long records (1996-2013) of a restricted compound (bentazone), three banned compounds (atrazine, diuron and simazine) and two metabolites (deethylatrazine (DEA) and 2,6-dichlorobenzamide (BAM)) sampled in the Hesbaye chalk aquifer in Belgium. In the confined area, all compounds had non-detects fractions >80%. By contrast, maximum concentrations exceeded EU's drinking-water standard (100 ng L(-1)) in the unconfined area. This contrast confirms that recent recharge and polluted water did not reach the confined area, yet. Multivariate analyses based on variables representative of the hydrogeological setting revealed higher diuron and simazine concentrations in the southeast of the unconfined area, where urban activities dominate land use and where the aquifer lacks protection from a less permeable layer of hardened chalk. At individual sites, positive correlations (up to τ=0.48 for bentazone) between pesticide compound concentrations and multi-annual groundwater level fluctuations confirm occurrences of remobilization. A downward temporal trend of atrazine concentrations likely reflects decreasing use of this compound over the last 28 years. However, the lack of a break in concentrations time series and maximum concentrations of atrazine, simazine, DEA and BAM exceeding EU's standard post-ban years provide evidence of persistence. Contrasting upward trends in bentazone concentrations show that a time lag is required for restriction measures to be efficient. These results shed light on factors governing pesticide

  9. Brain networks of temporal preparation: A multiple regression analysis of neuropsychological data.

    PubMed

    Triviño, Mónica; Correa, Ángel; Lupiáñez, Juan; Funes, María Jesús; Catena, Andrés; He, Xun; Humphreys, Glyn W

    2016-11-15

    There are only a few studies on the brain networks involved in the ability to prepare in time, and most of them followed a correlational rather than a neuropsychological approach. The present neuropsychological study performed multiple regression analysis to address the relationship between both grey and white matter (measured by magnetic resonance imaging in patients with brain lesion) and different effects in temporal preparation (Temporal orienting, Foreperiod and Sequential effects). Two versions of a temporal preparation task were administered to a group of 23 patients with acquired brain injury. In one task, the cue presented (a red versus green square) to inform participants about the time of appearance (early versus late) of a target stimulus was blocked, while in the other task the cue was manipulated on a trial-by-trial basis. The duration of the cue-target time intervals (400 versus 1400ms) was always manipulated within blocks in both tasks. Regression analysis were conducted between either the grey matter lesion size or the white matter tracts disconnection and the three temporal preparation effects separately. The main finding was that each temporal preparation effect was predicted by a different network of structures, depending on cue expectancy. Specifically, the Temporal orienting effect was related to both prefrontal and temporal brain areas. The Foreperiod effect was related to right and left prefrontal structures. Sequential effects were predicted by both parietal cortex and left subcortical structures. These findings show a clear dissociation of brain circuits involved in the different ways to prepare in time, showing for the first time the involvement of temporal areas in the Temporal orienting effect, as well as the parietal cortex in the Sequential effects.

  10. Spill prevention using multiple level measurement technologies

    SciTech Connect

    Bahner, M.

    1995-12-31

    This paper demonstrates that for spill prevention of aboveground storage tanks, a multiple technology system gives the best security in avoiding costly spills. A combination of RF Admittance (Capacitance) switches and Ultrasonic Gap Switches gives the best available combination of high and high-high alarming. RF Admittance switches handle the widest range of process conditions while ultrasonic gap switches feature no calibration for added security. Both of these technologies may be equipped with self-checking diagnostics and full functional testing of the entire spill prevention control loop.

  11. Detection of Temporally Coherent Light at Low Signal Levels.

    DTIC Science & Technology

    1977-01-01

    In writing this expression we assume normal incidence upon a planar cathode. For our analysis we make the simplifying assumption that I is...following analysis for simplicity in interpreting certain results. The objective of this investigation has been to find means of detecting coherent... analysis to consider the process. 6.1 Definition of Signal In attempting to detect temporally coherent light in a noncoherent background from the photon

  12. Perceived Impact of Spasticity Is Associated with Spatial and Temporal Parameters of Gait in Multiple Sclerosis

    PubMed Central

    Balantrapu, Swathi; Sandroff, Brian M.; Sosnoff, Jacob J.; Motl, Robert W.

    2012-01-01

    Background. Spasticity is prevalent and disabling in persons with multiple sclerosis (MS), and the development of the Multiple Sclerosis Spasticity Scale-88 (MSSS-88) provides an opportunity for examining the perceived impact of spasticity and its association with gait in this population. Purpose. This study examined the association between the perceived impact of spasticity and spatio-temporal parameters of gait in persons with MS. Methods. The sample included 44 adults with MS who completed the MSSS-88 and 4 walking trials on a 26-foot GAITRiteTM electronic walkway for measurement of spatio-temporal components of gait including velocity, cadence, base of support, step time, single support, double support, and swing phase. Results. The overall MSSS-88 score was significantly associated with velocity (r = −0.371), cadence (r = −0.306), base of support (r = 0.357), step time (r = 0.305), single leg support (r = −0.388), double leg support (r = 0.379), and swing phase (r = −0.386). Conclusions. The perceived impact of spasticity coincides with alterations of the spatio-temporal parameters of gait in MS. This indicates that subsequent interventions might target a decrease in spasticity or its perceived impact as an approach for improving mobility in MS. PMID:22462022

  13. Multiple spatio-temporal scale modeling of composites subjected to cyclic loading

    NASA Astrophysics Data System (ADS)

    Crouch, Robert; Oskay, Caglar; Clay, Stephen

    2013-01-01

    This manuscript presents a multiscale modeling methodology for failure analysis of composites subjected to cyclic loading conditions. Computational homogenization theory with multiple spatial and temporal scales is employed to devise the proposed methodology. Multiple spatial scales address the disparity between the length scale of material heterogeneities and the overall structure, whereas multiple temporal scales with almost periodic fields address the disparity between the load period and overall life under cyclic loading. The computational complexity of the multiscale modeling approach is reduced by employing a meso-mechanical model based on eigendeformation based homogenization with symmetric coefficients in the space domain, and an adaptive time stepping strategy based on a quadratic multistep method with error control in the time domain. The proposed methodology is employed to simulate the response of graphite fiber-reinforced epoxy composites. Model parameters are calibrated using a suite of experiments conducted on unidirectionally reinforced specimens subjected to monotonic and cyclic loading. The calibrated model is employed to predict damage progression in quasi-isotropic specimens. The capabilities of the model are validated using acoustic emission testing.

  14. Temporally controlled multiple-gene delivery in scaffolds: A promising strategy to enhance bone regeneration.

    PubMed

    Liu, Jinsong; Xu, Lihua; Li, Yiming; Ma, Jianfeng

    2011-02-01

    Bone defects sometimes require more effective repair regimens than conventional clinical therapies can provide. On account of this, tissue-engineered scaffolds have emerged as a promising alternative. Scaffolds that release genes encoding growth factors (GFs) offer additional benefits for bone regeneration in comparison with scaffolds providing protein delivery. The present gene delivery systems focus on unitary or dual genes delivery without controlled release. In the meantime, evidences indicate that bone formation is a complex cascade of events, in which time-dependent expression of multiple growth factors is involved. In our hypothesis, a temporally controlled, multi-gene delivery system embedded in a scaffold matrix can be fabricated; such a system is capable of mimicking the expression of growth factor profile in osteogenesis. Consequently, bone regeneration can be promoted by sequential gene expression of multiple growth factors.

  15. ePRISM: A case study in multiple proxy and mixed temporal resolution integration

    USGS Publications Warehouse

    Robinson, Marci M.; Dowsett, Harry J.

    2010-01-01

    As part of the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project, we present the ePRISM experiment designed I) to provide climate modelers with a reconstruction of an early Pliocene warm period that was warmer than the PRISM interval (similar to 3.3 to 3.0 Ma), yet still similar in many ways to modern conditions and 2) to provide an example of how best to integrate multiple-proxy sea surface temperature (SST) data from time series with varying degrees of temporal resolution and age control as we begin to build the next generation of PRISM, the PRISM4 reconstruction, spanning a constricted time interval. While it is possible to tie individual SST estimates to a single light (warm) oxygen isotope event, we find that the warm peak average of SST estimates over a narrowed time interval is preferential for paleoclimate reconstruction as it allows for the inclusion of more records of multiple paleotemperature proxies.

  16. Temporally controlled release of multiple growth factors from a self-assembling peptide hydrogel

    NASA Astrophysics Data System (ADS)

    Bruggeman, Kiara F.; Rodriguez, Alexandra L.; Parish, Clare L.; Williams, Richard J.; Nisbet, David R.

    2016-09-01

    Protein growth factors have demonstrated great potential for tissue repair, but their inherent instability and large size prevents meaningful presentation to biologically protected nervous tissue. Here, we create a nanofibrous network from a self-assembling peptide (SAP) hydrogel to carry and stabilize the growth factors. We significantly reduced growth factor degradation to increase their lifespan by over 40 times. To control the temporal release profile we covalently attached polysaccharide chitosan molecules to the growth factor to increase its interactions with the hydrogel nanofibers and achieved a 4 h delay, demonstrating the potential of this method to provide temporally controlled growth factor delivery. We also describe release rate based analysis to examine the growth factor delivery in more detail than standard cumulative release profiles allow and show that the chitosan attachment method provided a more consistent release profile with a 60% reduction in fluctuations. To prove the potential of this system as a complex growth factor delivery platform we demonstrate for the first time temporally distinct release of multiple growth factors from a single tissue specific SAP hydrogel: a significant goal in regenerative medicine.

  17. Long-term music training tunes how the brain temporally binds signals from multiple senses.

    PubMed

    Lee, Hweeling; Noppeney, Uta

    2011-12-20

    Practicing a musical instrument is a rich multisensory experience involving the integration of visual, auditory, and tactile inputs with motor responses. This combined psychophysics-fMRI study used the musician's brain to investigate how sensory-motor experience molds temporal binding of auditory and visual signals. Behaviorally, musicians exhibited a narrower temporal integration window than nonmusicians for music but not for speech. At the neural level, musicians showed increased audiovisual asynchrony responses and effective connectivity selectively for music in a superior temporal sulcus-premotor-cerebellar circuitry. Critically, the premotor asynchrony effects predicted musicians' perceptual sensitivity to audiovisual asynchrony. Our results suggest that piano practicing fine tunes an internal forward model mapping from action plans of piano playing onto visible finger movements and sounds. This internal forward model furnishes more precise estimates of the relative audiovisual timings and hence, stronger prediction error signals specifically for asynchronous music in a premotor-cerebellar circuitry. Our findings show intimate links between action production and audiovisual temporal binding in perception.

  18. Multiple dipole modeling and localization from spatio-temporal MEG data

    SciTech Connect

    Mosher, J.C. ); Lewis, P.S. ); Leahy, R. )

    1992-06-01

    An array of biomagnetometers may be used to measure the spatio-temporal neuromagnetic field or magnetoencephalogram (MEG) produced by neural activity in the brain. A popular model for the neural activity produced in response to a given sensory stimulus is a set of current dipoles, where each dipole represents the primary current associated with the combined activation of a large number of neutrons located in a small volume of the brain. An important problem in the interpretation of MEG data from evoked response experiments is the localization of these neural current dipoles. The authors present here a linear algebraic framework for three common spatio-temporal dipole models: (i) unconstrained dipoles, (ii) dipoles with a fixed location, and (iii) dipoles with a fixed orientation and location. In all cases, they assume that the location, orientation, and magnitude of the dipoles are unknown. With a common model, they show how the parameter estimation problem may be decomposed into the estimation of the time invariant parameter using nonlinear least-squares minimization, followed by linear estimation of the associated time varying parameters. A subspace formulation is presented and used to derive a suboptimal least-squares subspace scanning method. The resulting algorithm is a special case of the well-known MUltiple SIgnal Classification (MUSIC) method, in which the solution (multiple dipole locations) is found by scanning potential locations using a simple one dipole model.

  19. Describing multiple levels of abstraction in the metabolism

    SciTech Connect

    Mavrovouniotis, M.L.

    1994-12-31

    We discuss some central issues that arise in the computer representation of the metabolism and its subsystems. We provide a framework for the representation of metabolites and bioreactions at multiple levels of detail. The framework is based on defining an explicit linear mapping of metabolites and reactions from one level of detail to another. A simple reaction mechanism serves as an illustration and shows the emergence of the concept of a catalyst from metabolic abstraction levels.

  20. Patterns of temporal scaling of groundwater level fluctuation

    NASA Astrophysics Data System (ADS)

    Yu, Xue; Ghasemizadeh, Reza; Padilla, Ingrid Y.; Kaeli, David; Alshawabkeh, Akram

    2016-05-01

    We studied the fractal scaling behavior of groundwater level fluctuation for various types of aquifers in Puerto Rico using the methods of (1) detrended fluctuation analysis (DFA) to examine the monofractality and (2) wavelet transform maximum modulus (WTMM) to analyze the multifractality. The DFA results show that fractals exist in groundwater fluctuations of all the aquifers with scaling patterns that are anti-persistent (1 < β < 1.5; 1.32 ± 0.12, 18 wells) or persistent (β > 1.5; 1.62 ± 0.07, 4 wells). The multifractal analysis confirmed the need to characterize these highly complex processes with multifractality, which originated from the stochastic distribution of the irregularly-shaped fluctuations. The singularity spectra of the fluctuation processes in each well were site specific. We found a general elevational effect with smaller fractal scaling coefficients in the shallower wells, except for the Northern Karst Aquifer Upper System. High spatial variability of fractal scaling of groundwater level fluctuations in the karst aquifer is due to the coupled effects of anthropogenic perturbations, precipitation, elevation and particularly the high heterogeneous hydrogeological conditions.

  1. Temporal Processing Capacity in High-Level Visual Cortex Is Domain Specific

    PubMed Central

    Weiner, Kevin S.; Grill-Spector, Kalanit

    2015-01-01

    Prevailing hierarchical models propose that temporal processing capacity—the amount of information that a brain region processes in a unit time—decreases at higher stages in the ventral stream regardless of domain. However, it is unknown if temporal processing capacities are domain general or domain specific in human high-level visual cortex. Using a novel fMRI paradigm, we measured temporal capacities of functional regions in high-level visual cortex. Contrary to hierarchical models, our data reveal domain-specific processing capacities as follows: (1) regions processing information from different domains have differential temporal capacities within each stage of the visual hierarchy and (2) domain-specific regions display the same temporal capacity regardless of their position in the processing hierarchy. In general, character-selective regions have the lowest capacity, face- and place-selective regions have an intermediate capacity, and body-selective regions have the highest capacity. Notably, domain-specific temporal processing capacities are not apparent in V1 and have perceptual implications. Behavioral testing revealed that the encoding capacity of body images is higher than that of characters, faces, and places, and there is a correspondence between peak encoding rates and cortical capacities for characters and bodies. The present evidence supports a model in which the natural statistics of temporal information in the visual world may affect domain-specific temporal processing and encoding capacities. These findings suggest that the functional organization of high-level visual cortex may be constrained by temporal characteristics of stimuli in the natural world, and this temporal capacity is a characteristic of domain-specific networks in high-level visual cortex. SIGNIFICANCE STATEMENT Visual stimuli bombard us at different rates every day. For example, words and scenes are typically stationary and vary at slow rates. In contrast, bodies are dynamic

  2. Temporal Processing Capacity in High-Level Visual Cortex Is Domain Specific.

    PubMed

    Stigliani, Anthony; Weiner, Kevin S; Grill-Spector, Kalanit

    2015-09-09

    Prevailing hierarchical models propose that temporal processing capacity--the amount of information that a brain region processes in a unit time--decreases at higher stages in the ventral stream regardless of domain. However, it is unknown if temporal processing capacities are domain general or domain specific in human high-level visual cortex. Using a novel fMRI paradigm, we measured temporal capacities of functional regions in high-level visual cortex. Contrary to hierarchical models, our data reveal domain-specific processing capacities as follows: (1) regions processing information from different domains have differential temporal capacities within each stage of the visual hierarchy and (2) domain-specific regions display the same temporal capacity regardless of their position in the processing hierarchy. In general, character-selective regions have the lowest capacity, face- and place-selective regions have an intermediate capacity, and body-selective regions have the highest capacity. Notably, domain-specific temporal processing capacities are not apparent in V1 and have perceptual implications. Behavioral testing revealed that the encoding capacity of body images is higher than that of characters, faces, and places, and there is a correspondence between peak encoding rates and cortical capacities for characters and bodies. The present evidence supports a model in which the natural statistics of temporal information in the visual world may affect domain-specific temporal processing and encoding capacities. These findings suggest that the functional organization of high-level visual cortex may be constrained by temporal characteristics of stimuli in the natural world, and this temporal capacity is a characteristic of domain-specific networks in high-level visual cortex. Significance statement: Visual stimuli bombard us at different rates every day. For example, words and scenes are typically stationary and vary at slow rates. In contrast, bodies are dynamic

  3. A Temporal Model of Level-Invariant, Tone-in-Noise Detection

    ERIC Educational Resources Information Center

    Berg, Bruce G.

    2004-01-01

    Level-invariant detection refers to findings that thresholds in tone-in-noise detection are unaffected by roving-level procedures that degrade energy cues. Such data are inconsistent with ideas that detection is based on the energy passed by an auditory filter. A hypothesis that detection is based on a level-invariant temporal cue is advanced.…

  4. Water Level Temporal Variation Analysis at Prata Basin Using GRACE

    NASA Astrophysics Data System (ADS)

    Guimaraes, G.; Blitzkow, D.; Matos, A.; Vaz, F.; Campos, I.; Barbosa, A.

    2008-12-01

    A comparison between daily in-situ water level time series measured at ground-based hydrometric stations of Agência Nacional de Águas (ANA) with vertically-integrated water height deduced from GRACE geoid (height anomaly) is carried out. The 10-day intervals of GRACE models were computed by Groupe de Recherches de Géodésie Spatiale (CNES/GRGS). The height anomaly was converted into equivalent water height, over the Prata basin for a ~6-year period (July-2002 to May-2008). A correlation around 74 per cent has been detected. This correlation allows defining a local transfer function by adjusting a linear relationship between GRACE-based and in situ observation time-series. The study of the Continuous Wavelet Transform was applied in the hydrometric stations and a time-scale correlation was figured out.

  5. Embellishment of Student Leadership in Learning Multiplication at Primary Level

    ERIC Educational Resources Information Center

    Singaravelu, G.

    2006-01-01

    The present study enlightens the efficacy of Student Leadership method in learning Multiplication in Mathematics at primary level. Single group experimental method was adopted for the study. Forty learners studying in Standard III in Panchayat union primary School, Muthupettai in South Tamil Nadu, India have been selected as sample for the study.…

  6. The Effect of Internal Climate Variability on Spatial and Temporal Patterns of Sea-Level Rise Variations and Projections

    NASA Astrophysics Data System (ADS)

    Hogan, E.; Sriver, R. L.

    2014-12-01

    Natural (or internal) climate variability can influence spatial patterns of sea-level variations on interannual-to-interdecadal time scales, through redistribution of ocean heat and dynamical changes in ocean circulations and surface winds. These variations can impact analyses of past and potential future sea-level rise, particularly when considering upper bound projections on regional scales. Here we analyze spatial and temporal sea-level variations due to steric and dynamic effects, using results from a 50-member climate change ensemble experiment that samples internal variability of the coupled ocean-atmosphere system. We use the low-resolution configuration of the fully-coupled Community Earth System Model (CESM), comprised of transient hindcasts and projections (1850-2100) using historic and RCP8.5 forcings. The transient simulations are initialized from unique model states, sampled from a ~10,000 year fully coupled unforced equilibrium simulation. This approach enables us to examine the effect of initial conditions uncertainty (or internal variability) within the coupled system, including effects of the full ocean which has a longer dynamical time scale than the atmosphere. We find that the internal variability within the coupled ocean-atmosphere climate model significantly affects spatial patterns of dynamic and steric sea-level changes across multiple timescales. We evaluate model skill using the historical record of past trends and variations across multiple scales, and we explore the implications of these results for sea-level rise projections. A key result is that natural variations of sea-level change can significantly impact upper-bound projections at regional scales, which can potentially impact risk assessments and adaptation strategies. More generally, these results point to the potential importance of the role of ocean dynamics and memory in influencing sea-level rise variations across multiple spatial and temporal scales.

  7. Assessing Temporal and Spatial Patterns of Observed and Predicted Ozone in Multiple Urban Areas

    PubMed Central

    Simon, Heather; Wells, Benjamin; Baker, Kirk R.; Hubbell, Bryan

    2016-01-01

    Background: Ambient monitoring data show spatial gradients in ozone (O3) across urban areas. Nitrogen oxide (NOx) emissions reductions will likely alter these gradients. Epidemiological studies often use exposure surrogates that may not fully account for the impacts of spatially and temporally changing concentrations on population exposure. Objectives: We examined the impact of large NOx decreases on spatial and temporal O3 patterns and the implications on exposure. Methods: We used a photochemical model to estimate O3 response to large NOx reductions. We derived time series of 2006–2008 O3 concentrations consistent with 50% and 75% NOx emissions reduction scenarios in three urban areas (Atlanta, Philadelphia, and Chicago) at each monitor location and spatially interpolated O3 to census-tract centroids. Results: We predicted that low O3 concentrations would increase and high O3 concentrations would decrease in response to NOx reductions within an urban area. O3 increases occurred across larger areas for the seasonal mean metric than for the regulatory metric (annual 4th highest daily 8-hr maximum) and were located only in urban core areas. O3 always decreased outside the urban core (e.g., at locations of maximum local ozone concentration) for both metrics and decreased within the urban core in some instances. NOx reductions led to more uniform spatial gradients and diurnal and seasonal patterns and caused seasonal peaks in midrange O3 concentrations to shift from midsummer to earlier in the year. Conclusions: These changes have implications for how O3 exposure may change in response to NOx reductions and are informative for the design of future epidemiology studies and risk assessments. Citation: Simon H, Wells B, Baker KR, Hubbell B. 2016. Assessing temporal and spatial patterns of observed and predicted ozone in multiple urban areas. Environ Health Perspect 124:1443–1452; http://dx.doi.org/10.1289/EHP190 PMID:27153213

  8. Heralded generation of single photons entangled in multiple temporal modes with controllable waveforms

    NASA Astrophysics Data System (ADS)

    Gogyan, A.; Sisakyan, N.; Akhmedzhanov, R.; Malakyan, Yu

    2014-11-01

    Time-bin entangled single-photons are highly demanded for long distance quantum communication. We propose a heralded source of tunable narrowband single photons entangled in well-separated multiple temporal modes (time bins) with controllable amplitudes. The detection of a single Stokes photon generated in a cold atomic ensemble via Raman scattering of a weak write pulse heralds the preparation of one spin excitation stored within the atomic medium. A train of read laser pulses deterministically converts the atomic excitation into a single anti-Stokes photon delocalized in multi-time-bins. The waveforms of bins are well-controlled by the read pulse parameters. A scheme to measure the phase coherence across all time bins is suggested.

  9. Collective synchronization of self/non-self discrimination in T cell activation, across multiple spatio-temporal scales

    NASA Astrophysics Data System (ADS)

    Altan-Bonnet, Gregoire

    The immune system is a collection of cells whose function is to eradicate pathogenic infections and malignant tumors while protecting healthy tissues. Recent work has delineated key molecular and cellular mechanisms associated with the ability to discriminate self from non-self agents. For example, structural studies have quantified the biophysical characteristics of antigenic molecules (those prone to trigger lymphocyte activation and a subsequent immune response). However, such molecular mechanisms were found to be highly unreliable at the individual cellular level. We will present recent efforts to build experimentally validated computational models of the immune responses at the collective cell level. Such models have become critical to delineate how higher-level integration through nonlinear amplification in signal transduction, dynamic feedback in lymphocyte differentiation and cell-to-cell communication allows the immune system to enforce reliable self/non-self discrimination at the organism level. In particular, we will present recent results demonstrating how T cells tune their antigen discrimination according to cytokine cues, and how competition for cytokine within polyclonal populations of cells shape the repertoire of responding clones. Additionally, we will present recent theoretical and experimental results demonstrating how competition between diffusion and consumption of cytokines determine the range of cell-cell communications within lymphoid organs. Finally, we will discuss how biochemically explicit models, combined with quantitative experimental validation, unravel the relevance of new feedbacks for immune regulations across multiple spatial and temporal scales.

  10. A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks

    PubMed Central

    Zhang, Ruisheng; Liu, Qidong

    2017-01-01

    Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research. PMID:28135288

  11. A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks.

    PubMed

    Liu, Xin; Zhang, Ruisheng; Liu, Qidong

    2017-01-01

    Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research.

  12. Change detection using vegetation indices and multiplatform satellite imagery at multiple temporal and spatial scales

    USGS Publications Warehouse

    Glenn, Edward P.; Nagler, Pamela L.; Huete, Alfredo R.; Weng, Qihao

    2014-01-01

    This chapter describes emerging methods for using satellite imagery across temporal and spatial scales using a case study approach to illustrate some of the opportunities now available for combining observations across scales. It explores the use of multiplatform sensor systems to characterize ecological change, as exemplified by efforts to scale the effects of a biocontrol insect (the leaf beetle Diorhabda carinulata) on the phenology and water use of Tamarix shrubs (Tamarix ramosissima and related species and hybrids) targeted for removal on western U.S. rivers, from the level of individual leaves to the regional level of measurement. Finally, the chapter summarizes the lessons learned and emphasize the need for ground data to calibrate and validate remote sensing data and the types of errors inherent in scaling point data over wide areas, illustrated with research on evapotranspiration (ET) of Tamarix using a wide range of ground measurement and remote sensing methods.

  13. Multiple Imputation of Groundwater Data to Evaluate Spatial and Temporal Anthropogenic Influences on Subsurface Water Fluxes in Los Angeles, CA

    NASA Astrophysics Data System (ADS)

    Manago, K. F.; Hogue, T. S.; Hering, A. S.

    2014-12-01

    In the City of Los Angeles, groundwater accounts for 11% of the total water supply on average, and 30% during drought years. Due to ongoing drought in California, increased reliance on local water supply highlights the need for better understanding of regional groundwater dynamics and estimating sustainable groundwater supply. However, in an urban setting, such as Los Angeles, understanding or modeling groundwater levels is extremely complicated due to various anthropogenic influences such as groundwater pumping, artificial recharge, landscape irrigation, leaking infrastructure, seawater intrusion, and extensive impervious surfaces. This study analyzes anthropogenic effects on groundwater levels using groundwater monitoring well data from the County of Los Angeles Department of Public Works. The groundwater data is irregularly sampled with large gaps between samples, resulting in a sparsely populated dataset. A multiple imputation method is used to fill the missing data, allowing for multiple ensembles and improved error estimates. The filled data is interpolated to create spatial groundwater maps utilizing information from all wells. The groundwater data is evaluated at a monthly time step over the last several decades to analyze the effect of land cover and identify other influencing factors on groundwater levels spatially and temporally. Preliminary results show irrigated parks have the largest influence on groundwater fluctuations, resulting in large seasonal changes, exceeding changes in spreading grounds. It is assumed that these fluctuations are caused by watering practices required to sustain non-native vegetation. Conversely, high intensity urbanized areas resulted in muted groundwater fluctuations and behavior decoupling from climate patterns. Results provides improved understanding of anthropogenic effects on groundwater levels in addition to providing high quality datasets for validation of regional groundwater models.

  14. Flicker adaptation of low-level cortical visual neurons contributes to temporal dilation

    PubMed Central

    Ortega, Laura; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2013-01-01

    Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Non-sensory factors such as increased arousal and attention have been thought to mediate this flicker-based temporal-dilation aftereffect. Here we provide evidence that adaptation of low-level cortical visual neurons contributes to this aftereffect. The aftereffect was significantly reduced by a 45° change in Gabor orientation between adaptation and test. Because orientation-tuning bandwidths are smaller in lower-level cortical visual areas and are approximately 45° in human V1, the result suggests that flicker adaptation of orientation-tuned V1 neurons contributes to the temporal-dilation aftereffect. The aftereffect was abolished when the adaptor and test stimuli were presented to different eyes. Because eye preferences are strong in V1 but diminish in higher-level visual areas, the eye specificity of the aftereffect corroborates the involvement of low-level cortical visual neurons. Our results thus suggest that flicker adaptation of low-level cortical visual neurons contributes to expanding visual duration. Furthermore, this temporal-dilation aftereffect dissociates from the previously reported temporal-constriction aftereffect on the basis of the differences in their orientation and flicker-frequency selectivity, suggesting that the visual system possesses at least two distinct and potentially complementary mechanisms for adaptively coding perceived duration. PMID:22866761

  15. Spatial and temporal patterns of enzootic raccoon rabies adjusted for multiple covariates

    PubMed Central

    Recuenco, Sergio; Eidson, Millicent; Kulldorff, Martin; Johnson, Glen; Cherry, Bryan

    2007-01-01

    Background With the objective of identifying spatial and temporal patterns of enzootic raccoon variant rabies, a spatial scan statistic was utilized to search for significant terrestrial rabies clusters by year in New York State in 1997–2003. Cluster analyses were unadjusted for other factors, adjusted for covariates, and adjusted for covariates and large scale geographic variation (LSGV). Adjustments were intended to identify the unusual aggregations of cases given the expected distribution based on the observed locations. Results Statistically significant clusters were identified particularly in the Albany, Finger Lakes, and South Hudson areas. The clusters were generally persistent in the Albany area, but demonstrated cyclical changes in rabies activity every few years in the other areas. Cluster adjustments allowed the discussion of possible causes for the high risk raccoon rabies areas identified. Conclusion This study analyzed raccoon variant rabies spatial and temporal patterns in New York that have not been previously described at a focal (census tract) level. Comparisons across the type of spatial analysis performed with various degrees of adjustment allow consideration of the potential influence of geographical factors for raccoon rabies and possible reasons for the highest risk areas (statistically significant clusters). PMID:17428324

  16. Multiple Object Based RFID System Using Security Level

    NASA Astrophysics Data System (ADS)

    Kim, Jiyeon; Jung, Jongjin; Ryu, Ukjae; Ko, Hoon; Joe, Susan; Lee, Yongjun; Kim, Boyeon; Chang, Yunseok; Lee, Kyoonha

    2007-12-01

    RFID systems are increasingly applied for operational convenience in wide range of industries and individual life. However, it is uneasy for a person to control many tags because common RFID systems have the restriction that a tag used to identify just a single object. In addition, RFID systems can make some serious problems in violation of privacy and security because of their radio frequency communication. In this paper, we propose a multiple object RFID tag which can keep multiple object identifiers for different applications in a same tag. The proposed tag allows simultaneous access for their pair applications. We also propose an authentication protocol for multiple object tag to prevent serious problems of security and privacy in RFID applications. Especially, we focus on efficiency of the authentication protocol by considering security levels of applications. In the proposed protocol, the applications go through different authentication procedures according to security level of the object identifier stored in the tag. We implemented the proposed RFID scheme and made experimental results about efficiency and stability for the scheme.

  17. Flicker Adaptation of Low-Level Cortical Visual Neurons Contributes to Temporal Dilation

    ERIC Educational Resources Information Center

    Ortega, Laura; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Nonsensory factors, such as increased arousal and attention, have been thought to mediate this flicker-based temporal-dilation aftereffect. In this study, we provide evidence that adaptation of low-level cortical visual…

  18. Multiple-level defect species evaluation from average carrier decay

    NASA Astrophysics Data System (ADS)

    Debuf, Didier

    2003-10-01

    An expression for the average decay is determined by solving the the carrier continuity equations, which include terms for multiple defect recombination. This expression is the decay measured by techniques such as the contactless photoconductance decay method, which determines the average or volume integrated decay. Implicit in the above is the requirement for good surface passivation such that only bulk properties are observed. A proposed experimental configuration is given to achieve the intended goal of an assessment of the type of defect in an n-type Czochralski-grown silicon semiconductor with an unusually high relative lifetime. The high lifetime is explained in terms of a ground excited state multiple-level defect system. Also, minority carrier trapping is investigated.

  19. Watt-level wireless power transmission to multiple compact receivers

    NASA Astrophysics Data System (ADS)

    Garraud, A.; Munzer, D. J.; Althar, M.; Garraud, N.; Arnold, D. P.

    2015-12-01

    This paper reports an electrodynamic wireless power transmission (EWPT) system using a low-frequency (300 Hz) magnetic field to transmit watt-scale power levels to multiple compact receivers. As compared to inductively or resonantly coupled coils, EWPT facilitates transmission to multiple non-interacting receivers with little restriction on their orientation. A single 3.0 cm3 receiver achieves 1.25 W power transmission with 8% efficiency at a distance of 1 cm (350 mW/cm3 power density) from the transmitter. The same prototype achieves 9 mW at a distance of 9 cm. Moreover, we demonstrate simultaneous recharge of two wearable devices, using two receivers located in arbitrary positions and orientations.

  20. Adrenomedullin protects from experimental autoimmune encephalomyelitis at multiple levels

    PubMed Central

    Pedreño, Marta; Morell, Maria; Robledo, Gema; Souza-Moreira, Luciana; Forte-Lago, Irene; Caro, Marta; O’Valle, Francisco; Ganea, Doina; Gonzalez-Rey, Elena

    2014-01-01

    Adrenomedullin is a neuropeptide known for its cardiovascular activities and anti-inflammatory effects. Here, we investigated the effect of adrenomedullin in a model of experimental autoimmune encephalomyelitis (EAE) that mirrors chronic progressive multiple sclerosis. A short-term systemic treatment with adrenomedullin reduced clinical severity and incidence of EAE, the appearance of inflammatory infiltrates in spinal cord and the subsequent demyelination and axonal damage. This effect was exerted at multiple levels affecting both early and late events of the disease. Adrenomedullin decreased the presence/activation of encephalitogenic Th1 and Th17 cells and down-regulated several inflammatory mediators in peripheral lymphoid organs and central nervous system. Noteworthy, adrenomedullin inhibited the production by encephalitogenic cells of osteopontin and of Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF), two critical cytokines in the development of EAE. At the same time, adrenomedullin increased the number of IL-10-producing regulatory T cells with suppressive effects on the progression of EAE. Furthermore, adrenomedullin generated dendritic cells with a semi-mature phenotype that impaired encephalitogenic responses in vitro and in vivo. Finally, adrenomedullin regulated glial activity and favored an active program of neuroprotection/regeneration. Therefore, the use of adrenomedullin emerges as a novel multimodal therapeutic approach to treat chronic progressive multiple sclerosis. PMID:24321213

  1. Diversity Promotes Temporal Stability across Levels of Ecosystem Organization in Experimental Grasslands

    PubMed Central

    Proulx, Raphaël; Wirth, Christian; Voigt, Winfried; Weigelt, Alexandra; Roscher, Christiane; Attinger, Sabine; Baade, Jussi; Barnard, Romain L.; Buchmann, Nina; Buscot, François; Eisenhauer, Nico; Fischer, Markus; Gleixner, Gerd; Halle, Stefan; Hildebrandt, Anke; Kowalski, Esther; Kuu, Annely; Lange, Markus; Milcu, Alex; Niklaus, Pascal A.; Oelmann, Yvonne; Rosenkranz, Stephan; Sabais, Alexander; Scherber, Christoph; Scherer-Lorenzen, Michael; Scheu, Stefan; Schulze, Ernst-Detlef; Schumacher, Jens; Schwichtenberg, Guido; Soussana, Jean-François; Temperton, Vicky M.; Weisser, Wolfgang W.; Wilcke, Wolfgang; Schmid, Bernhard

    2010-01-01

    The diversity–stability hypothesis states that current losses of biodiversity can impair the ability of an ecosystem to dampen the effect of environmental perturbations on its functioning. Using data from a long-term and comprehensive biodiversity experiment, we quantified the temporal stability of 42 variables characterizing twelve ecological functions in managed grassland plots varying in plant species richness. We demonstrate that diversity increases stability i) across trophic levels (producer, consumer), ii) at both the system (community, ecosystem) and the component levels (population, functional group, phylogenetic clade), and iii) primarily for aboveground rather than belowground processes. Temporal synchronization across studied variables was mostly unaffected with increasing species richness. This study provides the strongest empirical support so far that diversity promotes stability across different ecological functions and levels of ecosystem organization in grasslands. PMID:20967213

  2. Emergy evaluation of contrasting dairy systems at multiple levels.

    PubMed

    Vigne, Mathieu; Peyraud, Jean-Louis; Lecomte, Philippe; Corson, Michael S; Wilfart, Aurélie

    2013-11-15

    Emergy accounting (EmA) was applied to a range of dairy systems, from low-input smallholder systems in South Mali (SM), to intermediate-input systems in two regions of France, Poitou-Charentes (PC) and Bretagne (BR), to high-input systems on Reunion Island (RI). These systems were studied at three different levels: whole-farm (dairy system and cropping system), dairy-system (dairy herd and forage land), and herd (animals only). Dairy farms in SM used the lowest total emergy at all levels and was the highest user of renewable resources. Despite the low quality of resources consumed (crop residues and natural pasture), efficiency of their use was similar to that of industrialised inputs by intensive systems in RI, PC and BR. In addition, among the systems studied, SM dairy farms lay closest to environmental sustainability, contradicting the usual image of high environmental impact of cattle production in developing countries. EmA also revealed characteristics of the three intensive systems. Systems from RI and PC had lower resource transformation efficiency and higher environmental impacts than those from BR, due mainly to feeding strategies that differed due to differing socio-climatic constraints. Application of EmA at multiple levels revealed the importance of a multi-level analysis. While the whole-farm level assesses the overall contribution of the system to its environment, the dairy-system level is suitable for comparison of multi-product systems. In contrast, the herd level focuses on herd management and bypasses debates about definition of system boundaries by excluding land management. Combining all levels highlights the contribution of livestock to the global agricultural system and identifies inefficiencies and influences of system components on the environment.

  3. Spatial and temporal variations of mercury levels in Okefenokee invertebrates: southeast Georgia.

    PubMed

    George, Bagie M; Batzer, Darold

    2008-03-01

    Accumulation of mercury in wetland ecosystems has raised concerns about impacts on wetland food webs. This study measured concentrations of mercury in invertebrates of the Okefenokee Swamp in Georgia, focusing on levels in amphipods, odonates, and crayfish. We collected and analyzed total mercury levels in these invertebrates from 32 sampling stations across commonly occurring sub-habitats. Sampling was conducted in December, May, and August over a two-year period. The highest levels of mercury were detected in amphipods, with total mercury levels often in excess of 20 ppm. Bioaccumulation pathways of mercury in invertebrates of the Okefenokee are probably complex; despite being larger and higher in the food chain, levels in odonates and crayfish were much lower than in amphipods. Mercury levels in invertebrates varied temporally with the highest levels detected in May. There was a lack of spatial variation in mercury levels which is consistent with aerial deposition of mercury.

  4. Multiple metals predict prolactin and thyrotropin (TSH) levels in men

    SciTech Connect

    Meeker, John D.; Rossano, Mary G.; Protas, Bridget; Diamond, Michael P.; Puscheck, Elizabeth; Daly, Douglas; Paneth, Nigel; Wirth, Julia J.

    2009-10-15

    Exposure to a number of metals can affect neuroendocrine and thyroid signaling, which can result in adverse effects on development, behavior, metabolism, reproduction, and other functions. The present study assessed the relationship between metal concentrations in blood and serum prolactin (PRL) and thyrotropin (TSH) levels, markers of dopaminergic, and thyroid function, respectively, among men participating in a study of environmental influences on male reproductive health. Blood samples from 219 men were analyzed for concentrations of 11 metals and serum levels of PRL and TSH. In multiple linear regression models adjusted for age, BMI and smoking, PRL was inversely associated with arsenic, cadmium, copper, lead, manganese, molybdenum, and zinc, but positively associated with chromium. Several of these associations (Cd, Pb, Mo) are consistent with limited studies in humans or animals, and a number of the relationships (Cr, Cu, Pb, Mo) remained when additionally considering multiple metals in the model. Lead and copper were associated with non-monotonic decrease in TSH, while arsenic was associated with a dose-dependent increase in TSH. For arsenic these findings were consistent with recent experimental studies where arsenic inhibited enzymes involved in thyroid hormone synthesis and signaling. More research is needed for a better understanding of the role of metals in neuroendocrine and thyroid function and related health implications.

  5. Multiple circuits relaying primate parallel visual pathways to the middle temporal area.

    PubMed

    Nassi, Jonathan J; Callaway, Edward M

    2006-12-06

    Parallel pathways in the primate visual system parse the sensory signal into magnocellular (M), parvocellular (P), and koniocellular (K) streams. These pathways remain anatomically separate and distinct from their origination in different retinal ganglion cell types, through distinct layers of the lateral geniculate nucleus, and into primary visual cortex (V1), with the M pathway terminating primarily in layer 4Calpha, the P pathway in layer 4Cbeta, and the K pathway in the cytochrome oxidase blobs of layer 2/3. Recent studies indicate that outputs from V1 are less compartmental than previously thought, making it difficult to assess the contributions of M and P pathways to areas beyond V1 in the dorsal and ventral streams. Here we use rabies virus as a retrograde transsynaptic tracer to study the contributions of M and P pathways to areas middle temporal (MT), V3, and V2 of macaque monkey. We find that, although disynaptic inputs through layer 4C of V1 to dorsal stream area MT are dominated by the M pathway, within an additional three synapses MT receives a substantial P input. This P input is unlikely to reach MT via V3, which we show also receives disynaptic inputs dominated by the M pathway. We find that disynaptic inputs to V2, however, can be more balanced and may carry convergent M and P input to MT. Our observations provide evidence for multiple pathways from V1 to MT, with varying degrees of M and P convergence. Each pathway likely provides functionally specialized information to MT and dorsal stream visual processing.

  6. Selenoprotein expression is regulated at multiple levels in prostate cells.

    PubMed

    Rebsch, Cheryl M; Penna, Frank J; Copeland, Paul R

    2006-12-01

    Selenium supplementation in a population with low basal blood selenium levels has been reported to decrease the incidence of several cancers including prostate cancer. Based on the clinical findings, it is likely that the antioxidant function of one or more selenoproteins is responsible for the chemopreventive effect, although low molecular weight seleno-compounds have also been posited to selectively induce apoptosis in transformed cells. To address the effects of selenium supplementation on selenoprotein expression in prostate cells, we have undertaken an analysis of antioxidant selenoprotein expression as well as selenium toxicity in non-tumorigenic prostate epithelial cells (RWPE-1) and prostate cancer cells (LNCaP and PC-3). Our results show that two of the glutathione peroxidase family members (GPX1 and GPX4) are highly induced by supplemental selenium in prostate cancer cells but only slightly induced in RWPE-1 cells. In addition, GPX1 levels are dramatically lower in PC-3 cells as compared to RWPE-1 or LNCaP cells. GPX2 protein and mRNA, however, are only detectable in RWPE-1 cells. Of the three selenium compounds tested (sodium selenite, sodium selenate and selenomethionine), only sodium selenite shows toxicity in a physiological range of selenium concentrations. Notably and in contrast to previous studies, RWPE-1 cells were significantly more sensitive to selenite than either of the prostate cancer cell lines. These results demonstrate that selenoproteins and selenium metabolism are regulated at multiple levels in prostate cells.

  7. Exceptionally high levels of multiple mating in an army ant

    NASA Astrophysics Data System (ADS)

    Denny, A. Jay; Franks, Nigel R.; Powell, Scott; Edwards, Keith J.

    Most species of social insects have singly mated queens, although there are notable exceptions. Competing hypotheses have been proposed to explain the evolution of high levels of multiple mating, but this issue is far from resolved. Here we use microsatellites to investigate mating frequency in the army ant Eciton burchellii and show that queens mate with an exceptionally large number of males, eclipsing all but one other social insect species for which data are available. In addition we present evidence that suggests that mating is serial, continuing throughout the lifetime of the queen. This is the first demonstration of serial mating among social hymenoptera. We propose that high paternity within colonies is most likely to have evolved to increase genetic diversity and to counter high pathogen and parasite loads.

  8. Multivariate spatio-temporal modelling for assessing Antarctica's present-day contribution to sea-level rise

    PubMed Central

    Zammit-Mangion, Andrew; Rougier, Jonathan; Schön, Nana; Lindgren, Finn; Bamber, Jonathan

    2015-01-01

    Antarctica is the world's largest fresh-water reservoir, with the potential to raise sea levels by about 60 m. An ice sheet contributes to sea-level rise (SLR) when its rate of ice discharge and/or surface melting exceeds accumulation through snowfall. Constraining the contribution of the ice sheets to present-day SLR is vital both for coastal development and planning, and climate projections. Information on various ice sheet processes is available from several remote sensing data sets, as well as in situ data such as global positioning system data. These data have differing coverage, spatial support, temporal sampling and sensing characteristics, and thus, it is advantageous to combine them all in a single framework for estimation of the SLR contribution and the assessment of processes controlling mass exchange with the ocean. In this paper, we predict the rate of height change due to salient geophysical processes in Antarctica and use these to provide estimates of SLR contribution with associated uncertainties. We employ a multivariate spatio-temporal model, approximated as a Gaussian Markov random field, to take advantage of differing spatio-temporal properties of the processes to separate the causes of the observed change. The process parameters are estimated from geophysical models, while the remaining parameters are estimated using a Markov chain Monte Carlo scheme, designed to operate in a high-performance computing environment across multiple nodes. We validate our methods against a separate data set and compare the results to those from studies that invariably employ numerical model outputs directly. We conclude that it is possible, and insightful, to assess Antarctica's contribution without explicit use of numerical models. Further, the results obtained here can be used to test the geophysical numerical models for which in situ data are hard to obtain. © 2015 The Authors. Environmetrics published by John Wiley & Sons Ltd. PMID:25937792

  9. Multivariate spatio-temporal modelling for assessing Antarctica's present-day contribution to sea-level rise.

    PubMed

    Zammit-Mangion, Andrew; Rougier, Jonathan; Schön, Nana; Lindgren, Finn; Bamber, Jonathan

    2015-05-01

    Antarctica is the world's largest fresh-water reservoir, with the potential to raise sea levels by about 60 m. An ice sheet contributes to sea-level rise (SLR) when its rate of ice discharge and/or surface melting exceeds accumulation through snowfall. Constraining the contribution of the ice sheets to present-day SLR is vital both for coastal development and planning, and climate projections. Information on various ice sheet processes is available from several remote sensing data sets, as well as in situ data such as global positioning system data. These data have differing coverage, spatial support, temporal sampling and sensing characteristics, and thus, it is advantageous to combine them all in a single framework for estimation of the SLR contribution and the assessment of processes controlling mass exchange with the ocean. In this paper, we predict the rate of height change due to salient geophysical processes in Antarctica and use these to provide estimates of SLR contribution with associated uncertainties. We employ a multivariate spatio-temporal model, approximated as a Gaussian Markov random field, to take advantage of differing spatio-temporal properties of the processes to separate the causes of the observed change. The process parameters are estimated from geophysical models, while the remaining parameters are estimated using a Markov chain Monte Carlo scheme, designed to operate in a high-performance computing environment across multiple nodes. We validate our methods against a separate data set and compare the results to those from studies that invariably employ numerical model outputs directly. We conclude that it is possible, and insightful, to assess Antarctica's contribution without explicit use of numerical models. Further, the results obtained here can be used to test the geophysical numerical models for which in situ data are hard to obtain. © 2015 The Authors. Environmetrics published by John Wiley & Sons Ltd.

  10. CADASIL Presenting as Acute Bilateral Multiple Subcortical Infarcts without a Characteristic Temporal Pole or Any External Capsule Lesions

    PubMed Central

    Ando, Takashi; Goto, Yoji; Mano, Kazuo; Ueda, Akihiko; Ando, Yukio; Mizuta, Ikuko; Mizuno, Toshiki

    2016-01-01

    A 37-year-old man was hospitalized for an evaluation of acute bilateral multiple subcortical infarcts. There were no specific signal abnormalities in the temporal pole or external capsule. An abdominal skin biopsy showed granular, electron-dense, osmiophilic material (GOM) in the smooth muscle cells on electron microscopy. A direct sequencing analysis of NOTCH3 revealed a heterozygous c.986G>A substitution in exon 6, resulting in a Cys329Tyr amino acid replacement. According to these findings, the patient was diagnosed with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencehalopathy (CADASIL). Thus, early phases of CADASIL can present as acute bilateral multiple subcortical infarcts without a characteristic temporal pole or any external capsule lesions. PMID:27725551

  11. CADASIL Presenting as Acute Bilateral Multiple Subcortical Infarcts without a Characteristic Temporal Pole or Any External Capsule Lesions.

    PubMed

    Ando, Takashi; Goto, Yoji; Mano, Kazuo; Ueda, Akihiko; Ando, Yukio; Mizuta, Ikuko; Mizuno, Toshiki

    A 37-year-old man was hospitalized for an evaluation of acute bilateral multiple subcortical infarcts. There were no specific signal abnormalities in the temporal pole or external capsule. An abdominal skin biopsy showed granular, electron-dense, osmiophilic material (GOM) in the smooth muscle cells on electron microscopy. A direct sequencing analysis of NOTCH3 revealed a heterozygous c.986G>A substitution in exon 6, resulting in a Cys329Tyr amino acid replacement. According to these findings, the patient was diagnosed with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencehalopathy (CADASIL). Thus, early phases of CADASIL can present as acute bilateral multiple subcortical infarcts without a characteristic temporal pole or any external capsule lesions.

  12. Heterogeneity of the left temporal lobe in semantic representation and control: priming multiple versus single meanings of ambiguous words.

    PubMed

    Whitney, Carin; Jefferies, Elizabeth; Kircher, Tilo

    2011-04-01

    Semantic judgments involve both representations of meaning plus executive mechanisms that guide knowledge retrieval in a task-appropriate way. These 2 components of semantic cognition-representation and control-are commonly linked to left temporal and prefrontal cortex, respectively. This simple proposal, however, remains contentious because in most functional neuroimaging studies to date, the number of concepts being activated and the involvement of executive processes during retrieval are confounded. Using functional magnetic resonance imaging, we examined a task in which semantic representation and control demands were dissociable. Words with multiple meanings like "bank" served as targets in a double-prime paradigm, in which multiple meaning activation and maximal executive demands loaded onto different priming conditions. Anterior inferior temporal gyrus (ITG) was sensitive to the number of meanings that were retrieved, suggesting a role for this region in semantic representation, while posterior middle temporal gyrus (pMTG) and inferior frontal cortex showed greater activation in conditions that maximized executive demands. These results support a functional dissociation between left ITG and pMTG, consistent with a revised neural organization in which left prefrontal and posterior temporal areas work together to underpin aspects of semantic control.

  13. Multiple Level Crowding: Crowding at the Object Parts Level and at the Object Configural level.

    PubMed

    Kimchi, Ruth; Pirkner, Yossef

    2015-01-01

    In crowding, identification of a peripheral target in the presence of nearby flankers is worse than when the target appears alone. Prevailing theories hold that crowding occurs because of integration or "pooling" of low-level features at a single, relatively early stage of visual processing. Recent studies suggest that crowding can occur also between high-level object representations. The most relevant findings come from studies with faces and may be specific to faces. We examined whether crowding can occur at the object configural level in addition to part-level crowding, using nonface objects. Target (a disconnected square or diamond made of four elements) identification was measured at varying eccentricities. The flankers were similar either to the target parts or to the target configuration. The results showed crowding in both cases: Flankers interfered with target identification such that identification accuracy decreased with an increase in eccentricity, and no interference was observed at the fovea. Crowding by object parts, however, was weaker and had smaller spatial extent than crowding by object configurations; we related this finding to the relationship between crowding and perceptual organization. These results provide strong evidence that crowding occurs not only between object parts but also between configural representations of objects.

  14. Exploring multiple intelligences theory at a community college level

    NASA Astrophysics Data System (ADS)

    Berkemeier, Ginny Y. Hew

    The publication of "Frames of mind: The theory in practice", (Gardner, 1983) has been used by educators in a variety of ways to make teaching and learning more meaningful. However, little attention has been focused on the MI teaching and learning of science at the higher education level. Consequently, the purpose of this study was four fold. The first purpose was to investigate adult learning through Multiple Intelligence Theory (MI) at the community college level. The second purpose was to determine where there were any differences among students in their perceived MI with regard to age and gender. The third purpose was to investigate the relationship between perceived and tested MI strength with regard to science and non-science courses. The fourth purpose was to determine which MI teaching value relates best with science and non-science courses. Study participants were enrolled in science courses from a Midwestern community college, Ozarks Technical Community College (OTC). The research methodology of this research study consisted of a combination of quantitative analysis; using an inventory and qualitative analysis; through group interviews. Many positive outcomes resulted from the study in areas such as the relationships between tested MI and perceived MI, student learning in science and non-science courses, and their relationships to age and gender. This study suggested the need for a variety of education and curriculum reform that should start with students' attitudes instead of classroom instruction or methods of teaching.

  15. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe.

    PubMed

    Di, Guo-Qing; Zhou, Bing; Li, Zheng-Guang; Lin, Qi-Li

    2011-12-01

    In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L(WECPN)) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe.

  16. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe*

    PubMed Central

    Di, Guo-qing; Zhou, Bing; Li, Zheng-guang; Lin, Qi-li

    2011-01-01

    In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L WECPN) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe. PMID:22135145

  17. Interpreting temporal trends in Great Lakes organochlorine levels: Results from the herring gull surveillance program

    SciTech Connect

    Hebert, C.E.; Shutt, J.L.; Norstrom, R.J.; Weseloh, D.V.

    1995-12-31

    The Canadian Wildlife Service`s herring gull (Larus argentatus) surveillance program has demonstrated the utility of this species as a monitor of spatial and temporal trends in Great Lakes contaminant levels. Organochlorine concentrations in herring gull eggs decreased significantly in the 1970s and early 1980s as a result of control measures. Since the mid-1980s, however, concentrations of many compounds have been relatively constant. In addition, periodic fluctuations in egg contaminant concentrations hamper the ability to interpret more recent temporal trends in organochlorine levels. To evaluate the progress towards achieving the virtual elimination of organochlorines from the Great Lakes the authors must improve their understanding of the factors which regulate organochlorine bioaccumulation. This is particularly important for those species which have been selected as key indicators of ecosystem contamination, such as the herring gull. The goal of this paper is to examine some of the factors which may be responsible for the temporal fluctuations in herring gull egg contaminant concentrations. The regulation of contaminant bioavailability and transfer by changes in weather patterns and food web dynamics will be examined.

  18. The MAR-binding protein SATB1 orchestrates temporal and spatial expression of multiple genes during T-cell development

    PubMed Central

    Alvarez, John D.; Yasui, Dag H.; Niida, Hiroyuki; Joh, Tadashi; Loh, Dennis Y.; Kohwi-Shigematsu, Terumi

    2000-01-01

    SATB1 is expressed primarily in thymocytes and can act as a transcriptional repressor. SATB1 binds in vivo to the matrix attachment regions (MARs) of DNA, which are implicated in the loop domain organization of chromatin. The role of MAR-binding proteins in specific cell lineages is unknown. We generated SATB1-null mice to determine how SATB1 functions in the T-cell lineage. SATB1-null mice are small in size, have disproportionately small thymi and spleens, and die at 3 weeks of age. At the cellular level, multiple defects in T-cell development were observed. Immature CD3−CD4−CD8− triple negative (TN) thymocytes were greatly reduced in number, and thymocyte development was blocked mainly at the DP stage. The few peripheral CD4+ single positive (SP) cells underwent apoptosis and failed to proliferate in response to activating stimuli. At the molecular level, among 589 genes examined, at least 2% of genes including a proto-oncogene, cytokine receptor genes, and apoptosis-related genes were derepressed at inappropriate stages of T-cell development in SATB1-null mice. For example, IL-2Rα and IL-7Rα genes were ectopically transcribed in CD4+CD8+ double positive (DP) thymocytes. SATB1 appears to orchestrate the temporal and spatial expression of genes during T-cell development, thereby ensuring the proper development of this lineage. Our data provide the first evidence that MAR-binding proteins can act as global regulators of cell function in specific cell lineages. PMID:10716941

  19. Spatial-temporal variations in carbon dioxide levels in Ibadan, Nigeria.

    PubMed

    Ana, Godson R; Ojelabi, Peju; Shendell, Derek G

    2015-01-01

    Growing evidence suggests how global background levels of atmospheric carbon dioxide (CO2) are increasing and this impacts environmental quality and human and ecological health. Data from less developed countries are sparse. We determined spatial and temporal variations in concentrations of CO2 in selected locations in Ibadan, Nigeria with identifiable prominent outdoor sources. Activity driven areas in north and south-west areas were identified and marked with a global positioning system. Waste management practices and activities generating CO2 were documented and described using a technician observation checklist. CO2 levels were measured using a portable TELAIRE 7001 attached to HOBO U12 data loggers across seasons. Mean CO2 levels were compared over seasons, i.e. rainy season months and the dry season months. While CO2 levels recorded outdoors in study areas were comparable to available international data, routine monitoring is recommended to further characterize concurrent pollutants in fossil fuel combustion emissions with known deleterious health effects.

  20. Behavioural syndromes and social insects: personality at multiple levels.

    PubMed

    Jandt, Jennifer M; Bengston, Sarah; Pinter-Wollman, Noa; Pruitt, Jonathan N; Raine, Nigel E; Dornhaus, Anna; Sih, Andrew

    2014-02-01

    Animal personalities or behavioural syndromes are consistent and/or correlated behaviours across two or more situations within a population. Social insect biologists have measured consistent individual variation in behaviour within and across colonies for decades. The goal of this review is to illustrate the ways in which both the study of social insects and of behavioural syndromes has overlapped, and to highlight ways in which both fields can move forward through the synergy of knowledge from each. Here we, (i) review work to date on behavioural syndromes (though not always referred to as such) in social insects, and discuss mechanisms and fitness effects of maintaining individual behavioural variation within and between colonies; (ii) summarise approaches and principles from studies of behavioural syndromes, such as trade-offs, feedback, and statistical methods developed specifically to study behavioural consistencies and correlations, and discuss how they might be applied specifically to the study of social insects; (iii) discuss how the study of social insects can enhance our understanding of behavioural syndromes-research in behavioural syndromes is beginning to explore the role of sociality in maintaining or developing behavioural types, and work on social insects can provide new insights in this area; and (iv) suggest future directions for study, with an emphasis on examining behavioural types at multiple levels of organisation (genes, individuals, colonies, or groups of individuals).

  1. Temporal Synchronization Analysis for Improving Regression Modeling of Fecal Indicator Bacteria Levels

    EPA Science Inventory

    Multiple linear regression models are often used to predict levels of fecal indicator bacteria (FIB) in recreational swimming waters based on independent variables (IVs) such as meteorologic, hydrodynamic, and water-quality measures. The IVs used for these analyses are traditiona...

  2. Whole-community DNA barcoding reveals a spatio-temporal continuum of biodiversity at species and genetic levels.

    PubMed

    Baselga, Andrés; Fujisawa, Tomochika; Crampton-Platt, Alexandra; Bergsten, Johannes; Foster, Peter G; Monaghan, Michael T; Vogler, Alfried P

    2013-01-01

    A correlation of species and genetic diversity has been proposed but not uniformly supported. Large-scale DNA barcoding provides qualitatively novel data to test for correlations across hierarchical levels (genes, genealogies and species), and may help to unveil the underlying processes. Here we analyse sequence variation in communities of aquatic beetles across Europe (>5,000 individuals) to test for self-similarity of beta diversity patterns at multiple hierarchical levels. We show that community similarity at all levels decreases exponentially with geographic distance, and initial similarity is correlated with the lineage age, consistent with a molecular clock. Log-log correlations between lineage age, number of lineages, and range sizes, reveal a fractal geometry in time and space, indicating a spatio-temporal continuum of biodiversity across scales. Simulations show that these findings mirror dispersal-constrained models of haplotype distributions. These novel macroecological patterns may be explained by neutral evolutionary processes, acting continuously over time to produce multi-scale regularities of biodiversity.

  3. Timing vocal behavior: lack of temporal overlap avoidance to fluctuating noise levels in singing Eurasian wrens.

    PubMed

    Yang, Xiao-Jing; Slabbekoorn, Hans

    2014-10-01

    Many animals live in or near urban areas that have become increasingly widespread and noisy over the last century. Especially those species that rely heavily on acoustics for communication may be affected by these elevated anthropogenic noise levels. Many bird species that sing to defend their territories and to attract mates may have to exploit specific noise coping strategies to persist in such acoustically challenging conditions. Eurasian wrens (Troglodytes troglodytes), like several other bird species, have been shown in a previous experiment to time their vocalizations such that they avoid overlap with other singing birds. Here, we tested whether Eurasian wrens also time their songs to avoid overlap with fluctuating anthropogenic noise. However, we did not find any evidence in favor of this potential phenomenon. Territorial wrens persisted in singing without temporal adjustments in noisy territories with 'natural' fluctuations of traffic noise levels as well as during experimental exposure to intermittent white noise.

  4. Physical Activity Level and Medial Temporal Health in Youth at Ultra High-Risk for Psychosis

    PubMed Central

    Mittal, Vijay A.; Gupta, Tina; Orr, Joseph M.; Pelletier, Andrea L.; Dean, Derek J.; Lunsford-Avery, Jessica R.; Smith, Ashley K.; Robustelli, Briana L.; Leopold, Daniel R.; Millman, Zachary B.

    2014-01-01

    A growing body of evidence suggests that moderate to vigorous activity levels can affect quality of life, cognition, and brain structure in patients diagnosed with schizophrenia. However, physical activity has not been systematically studied during the period immediately preceding the onset of psychosis. Given reports of exercise-based neurogenesis in schizophrenia, understanding naturalistic physical activity levels in the prodrome may provide valuable information for early intervention efforts. The present study examined 29 ultra high-risk (UHR) and 27 matched controls to determine relationships between physical activity level, brain structure (hippocampus and parahippocampal gyrus), and symptoms. Participants were assessed with actigraphy for a 5-day period, magnetic resonance imaging (MRI), and structured clinical interviews. UHR participants showed a greater percentage of time in sedentary behavior while healthy controls spent more time engaged in light to vigorous activity. There was a strong trend to suggest the UHR group showed less total physical activity. The UHR group exhibited smaller medial temporal volumes when compared to healthy controls. Total level of physical activity in the UHR group was moderately correlated with smaller parahippocampal gyri bilaterally (right: r=.44, left: r=.55) and with occupational functioning (r=−.36; of negative symptom domain), but not positive symptomatology. Results suggest that inactivity is associated with medial temporal lobe health. Future studies are needed to determine if symptoms are driving inactivity, which in turn may be affecting the health of the parahippocampal structure and progression of illness. Although causality cannot be determined from the present design, these findings hold important implications for etiological conceptions and suggest promise for an experimental trial. PMID:24364613

  5. Multiple-Parameter Estimation Method Based on Spatio-Temporal 2-D Processing for Bistatic MIMO Radar.

    PubMed

    Yang, Shouguo; Li, Yong; Zhang, Kunhui; Tang, Weiping

    2015-12-14

    A novel spatio-temporal 2-dimensional (2-D) processing method that can jointly estimate the transmitting-receiving azimuth and Doppler frequency for bistatic multiple-input multiple-output (MIMO) radar in the presence of spatial colored noise and an unknown number of targets is proposed. In the temporal domain, the cross-correlation of the matched filters' outputs for different time-delay sampling is used to eliminate the spatial colored noise. In the spatial domain, the proposed method uses a diagonal loading method and subspace theory to estimate the direction of departure (DOD) and direction of arrival (DOA), and the Doppler frequency can then be accurately estimated through the estimation of the DOD and DOA. By skipping target number estimation and the eigenvalue decomposition (EVD) of the data covariance matrix estimation and only requiring a one-dimensional search, the proposed method achieves low computational complexity. Furthermore, the proposed method is suitable for bistatic MIMO radar with an arbitrary transmitted and received geometrical configuration. The correction and efficiency of the proposed method are verified by computer simulation results.

  6. Multiple-Parameter Estimation Method Based on Spatio-Temporal 2-D Processing for Bistatic MIMO Radar

    PubMed Central

    Yang, Shouguo; Li, Yong; Zhang, Kunhui; Tang, Weiping

    2015-01-01

    A novel spatio-temporal 2-dimensional (2-D) processing method that can jointly estimate the transmitting-receiving azimuth and Doppler frequency for bistatic multiple-input multiple-output (MIMO) radar in the presence of spatial colored noise and an unknown number of targets is proposed. In the temporal domain, the cross-correlation of the matched filters’ outputs for different time-delay sampling is used to eliminate the spatial colored noise. In the spatial domain, the proposed method uses a diagonal loading method and subspace theory to estimate the direction of departure (DOD) and direction of arrival (DOA), and the Doppler frequency can then be accurately estimated through the estimation of the DOD and DOA. By skipping target number estimation and the eigenvalue decomposition (EVD) of the data covariance matrix estimation and only requiring a one-dimensional search, the proposed method achieves low computational complexity. Furthermore, the proposed method is suitable for bistatic MIMO radar with an arbitrary transmitted and received geometrical configuration. The correction and efficiency of the proposed method are verified by computer simulation results. PMID:26694385

  7. Multiple anatomical systems embedded within the primate medial temporal lobe: implications for hippocampal function.

    PubMed

    Aggleton, John P

    2012-08-01

    A review of medial temporal lobe connections reveals three distinct groupings of hippocampal efferents. These efferent systems and their putative memory functions are: (1) The 'extended-hippocampal system' for episodic memory, which involves the anterior thalamic nuclei, mammillary bodies and retrosplenial cortex, originates in the subicular cortices, and has a largely laminar organisation; (2) The 'rostral hippocampal system' for affective and social learning, which involves prefrontal cortex, amygdala and nucleus accumbens, has a columnar organisation, and originates from rostral CA1 and subiculum; (3) The 'reciprocal hippocampal-parahippocampal system' for sensory processing and integration, which originates from the length of CA1 and the subiculum, and is characterised by columnar, connections with reciprocal topographies. A fourth system, the 'parahippocampal-prefrontal system' that supports familiarity signalling and retrieval processing, has more widespread prefrontal connections than those of the hippocampus, along with different thalamic inputs. Despite many interactions between these four systems, they may retain different roles in memory which when combined explain the importance of the medial temporal lobe for the formation of declarative memories.

  8. TEMPORAL EVOLUTION OF MULTIPLE EVAPORATING RIBBON SOURCES IN A SOLAR FLARE

    SciTech Connect

    Graham, D. R.; Cauzzi, G.

    2015-07-10

    We present new results from the Interface Region Imaging Spectrograph (IRIS) showing the dynamic evolution of chromospheric evaporation and condensation in a flare ribbon, with the highest temporal and spatial resolution to date. IRIS observed the entire impulsive phase of the X-class flare SOL2014-09-10T17:45 using a 9.4 s cadence “sit-and-stare” mode. As the ribbon brightened successively at new positions along the slit, a unique impulsive phase evolution was observed for many tens of individual pixels in both coronal and chromospheric lines. Each activation of a new footpoint displays the same initial coronal upflows of up to ∼300 km s{sup −1} and chromospheric downflows up to 40 km s{sup −1}. Although the coronal flows can be delayed by over 1 minute with respect to those in the chromosphere, the temporal evolution of flows is strikingly similar between all pixels and consistent with predictions from hydrodynamic flare models. Given the large sample of independent footpoints, we conclude that each flaring pixel can be considered a prototypical, “elementary” flare kernel.

  9. A test of multiple correlation temporal window characteristic of non-Markov processes

    NASA Astrophysics Data System (ADS)

    Arecchi, F. T.; Farini, A.; Megna, N.

    2016-03-01

    We introduce a sensitive test of memory effects in successive events. The test consists of a combination K of binary correlations at successive times. K decays monotonically from K = 1 for uncorrelated events as a Markov process. For a monotonic memory fading, K<1 always. Here we report evidence of a K>1 temporal window in cognitive tasks consisting of the visual identification of the front face of the Necker cube after a previous presentation of the same. We speculate that memory effects provide a temporal window with K>1 and this experiment could be a possible first step towards a better comprehension of this phenomenon. The K>1 behaviour is maximal at an inter-measurement time τ around 2s with inter-subject differences. The K>1 persists over a time window of 1s around τ; outside this window the K<1 behaviour is recovered. The universal occurrence of a K>1 window in pairs of successive perceptions suggests that, at variance with single visual stimuli eliciting a suitable response, a pair of stimuli shortly separated in time displays mutual correlations.

  10. Relationship between fluid-attenuated inversion-recovery (FLAIR) signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis.

    PubMed

    Varella, Pedro Paulo Vasconcellos; Santiago, Joselita Ferreira Carvalho; Carrete, Henrique; Higa, Elisa Mieko Suemitsu; Yacubian, Elza Márcia Targas; Centeno, Ricardo Silva; Caboclo, Luís Otávio Sales Ferreira; Castro Neto, Eduardo Ferreira de; Canzian, Mauro; Amado, Débora; Cavalheiro, Esper Abrão; Naffah-Mazzacoratti, Maria da Graça

    2011-02-01

    We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS) and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO) levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10) were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE) -MTS group (p<0.001), suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05) demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.

  11. Temporal pattern in the effect of postnatal blood lead level on intellectual development of young children.

    PubMed

    Schnaas, L; Rothenberg, S J; Perroni, E; Martínez, S; Hernández, C; Hernández, R M

    2000-01-01

    To determine the temporal pattern of the effect of postnatal blood lead level on the General Cognitive Index (GCI) of the McCarthy Scales of Children's Abilities, we used data from 112 children of the Mexico City Prospective Lead Study with complete evaluations from 36 to 60 months of age at 6-month intervals. We measured blood lead level every 6 months from 6 to 54 months. We controlled for 5-min Apgar, birth weight, birth order, sex, socioeconomic level, maternal IQ, and maximum maternal educational level in a repeated measures ANCOVA using child blood lead level grouped by 6-18 month (geometric mean 10.1 microg/dl, range 3.5-37.0 microg/dl), 24-36 month (geometric mean 9.7 microg/dl, range 3.0-42.7 microg/dl), and 42-54 month (geometric mean 8.4 microg/dl, range 2.5-44.8 microg/dl) averages. There were significant interactions between the 6-18 month blood lead level and age with GCI as the endpoint and between 24-36 month blood lead level and age. The regression coefficient of blood lead at 6-18 months became more negative with age until 48 months, when the rate of decline moderated (linear polynomial contrast p=0. 047). The regression coefficient of blood lead at 24-36 months with CGI became more negative as well from 36 to 48 months but then started decreasing toward zero from 48 to 60 months (quadratic polynomial contrast p=0.019). Significant between-subjects lead effects on GCI were found for 24-36 month blood lead level at 48 months (p=0.021) and at 54 months (p=0.073). The greatest effect (at 48 months) was a 5.8-point GCI decrease with each natural log unit increase in blood lead. Significant between-subjects lead effects on GCI were found for 42-54 month blood lead level at 54 months (p=0. 040) and at 60 months (p=0.060). The effect of postnatal blood lead level on GCI reaches its maximum approximately 1-3 years later, and then becomes less evident. Four to five years of age appears to be a critical period for the manifestation of the earlier postnatal

  12. Biodiversity at multiple trophic levels is needed for ecosystem multifunctionality.

    PubMed

    Soliveres, Santiago; van der Plas, Fons; Manning, Peter; Prati, Daniel; Gossner, Martin M; Renner, Swen C; Alt, Fabian; Arndt, Hartmut; Baumgartner, Vanessa; Binkenstein, Julia; Birkhofer, Klaus; Blaser, Stefan; Blüthgen, Nico; Boch, Steffen; Böhm, Stefan; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Heinze, Johannes; Hölzel, Norbert; Jung, Kirsten; Klaus, Valentin H; Kleinebecker, Till; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Morris, E Kathryn; Müller, Jörg; Oelmann, Yvonne; Overmann, Jörg; Pašalić, Esther; Rillig, Matthias C; Schaefer, H Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Sikorski, Johannes; Socher, Stephanie A; Solly, Emily F; Sonnemann, Ilja; Sorkau, Elisabeth; Steckel, Juliane; Steffan-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Türke, Manfred; Venter, Paul C; Weiner, Christiane N; Weisser, Wolfgang W; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Wolters, Volkmar; Wubet, Tesfaye; Wurst, Susanne; Fischer, Markus; Allan, Eric

    2016-08-25

    Many experiments have shown that loss of biodiversity reduces the capacity of ecosystems to provide the multiple services on which humans depend. However, experiments necessarily simplify the complexity of natural ecosystems and will normally control for other important drivers of ecosystem functioning, such as the environment or land use. In addition, existing studies typically focus on the diversity of single trophic groups, neglecting the fact that biodiversity loss occurs across many taxa and that the functional effects of any trophic group may depend on the abundance and diversity of others. Here we report analysis of the relationships between the species richness and abundance of nine trophic groups, including 4,600 above- and below-ground taxa, and 14 ecosystem services and functions and with their simultaneous provision (or multifunctionality) in 150 grasslands. We show that high species richness in multiple trophic groups (multitrophic richness) had stronger positive effects on ecosystem services than richness in any individual trophic group; this includes plant species richness, the most widely used measure of biodiversity. On average, three trophic groups influenced each ecosystem service, with each trophic group influencing at least one service. Multitrophic richness was particularly beneficial for 'regulating' and 'cultural' services, and for multifunctionality, whereas a change in the total abundance of species or biomass in multiple trophic groups (the multitrophic abundance) positively affected supporting services. Multitrophic richness and abundance drove ecosystem functioning as strongly as abiotic conditions and land-use intensity, extending previous experimental results to real-world ecosystems. Primary producers, herbivorous insects and microbial decomposers seem to be particularly important drivers of ecosystem functioning, as shown by the strong and frequent positive associations of their richness or abundance with multiple ecosystem services

  13. Levels and temporal trends of HCH isomers in ringed seals from West and East Greenland.

    PubMed

    Rigét, Frank; Vorkamp, Katrin; Dietz, Rune; Muir, Derek C G

    2008-08-01

    Levels and temporal trends of the hexachlorocyclohexane isomers alpha-, beta- and gamma-HCH were analysed in blubber of juvenile ringed seals from West Greenland (1994 to 2006) and juvenile and adult ringed seals from East Greenland (1986 to 2006). No significant differences in the concentration levels in the juvenile seals were found between East and West Greenland for any of the three isomers. alpha-HCH concentrations were not significantly different between juvenile and adult ringed seals from East Greenland, whereas beta- and gamma-HCH concentrations were significantly higher in adult ringed seals. alpha- and beta-HCH in Greenland ringed seals were approximately a factor two lower than in the Canadian Arctic, and alpha-HCH was a factor 2-3 higher than in ringed seals from an area east of Svalbard, Norway. Annual decreases in ringed seals from Greenland during the study periods were detected to be 9.1-11.7%, 1.4-3.9% and 6.0-6.4% for alpha-, beta- and gamma-HCH, respectively, being quite similar in both East and West Greenland. Similar levels and trends in East and West Greenland support the general understanding of the pathways of HCH isomers to and in the Arctic.

  14. Cotton Defense Induction Patterns Under Spatially, Temporally and Quantitatively Varying Herbivory Levels.

    PubMed

    Eisenring, Michael; Meissle, Michael; Hagenbucher, Steffen; Naranjo, Steven E; Wettstein, Felix; Romeis, Jörg

    2017-01-01

    In its defense against herbivores, cotton (Gossypium sp.) relies in part on the production of a set of inducible, non-volatile terpenoids. Under uniform damage levels, in planta allocation of induced cotton terpenoids has been found to be highest in youngest leaves, supporting assumptions of the optimal defense theory (ODT) which predicts that plants allocate defense compounds to tissues depending on their value and the likelihood of herbivore attack. However, our knowledge is limited on how varying, and thus more realistic, damage levels might affect cotton defense organization. We hypothesized that the allocation of terpenoids and densities of terpenoid-storing glands in leaves aligns with assumptions of the ODT, even when plants are subjected to temporally, spatially and quantitatively varying caterpillar (Heliothis virescens) damage. As expected, cotton plants allocated most of their defenses to their youngest leaves regardless of damage location. However, defense induction in older leaves varied with damage location. For at least 14 days after damage treatments ended, plants reallocated defense resources from previously young leaves to newly developed leaves. Furthermore, we observed a positive hyperbolic relationship between leaf damage area and both terpenoid concentrations and gland densities, indicating that cotton plants can fine-tune defense allocation. Although it appears that factors like vascular constraints and chemical properties of individual defense compounds can affect defense levels, our results overall demonstrate that induced defense organization of cotton subjected to varying damage treatments is in alignment with key assumptions of the ODT.

  15. Polycyclic aromatic hydrocarbons in air on small spatial and temporal scales - I. Levels and variabilities

    NASA Astrophysics Data System (ADS)

    Lammel, Gerhard; Klánová, Jana; Ilić, Predrag; Kohoutek, Jiří; Gasić, Bojan; Kovacić, Igor; Lakić, Nataša; Radić, Ranka

    2010-12-01

    Polycyclic aromatic hydrocarbons (PAHs) were measured together with inorganic air pollutants at two urban sites and one rural background site in the Banja Luka area, Bosnia and Hercegovina, during 72 h in July 2008 using a high time resolution (5 samples per day) with the aim to study the spatial and temporal variabilities and to explore the significance of averaging effects inherent to 24 h-sampling. Measurement uncertainty was quantified on basis of three independent side-by-side samplers, deployed at one of the sites. PAH abundances in the urban and rural environments differed largely. Levels at the urban sites exceeded the levels at the rural site by >100%. The discrepancy was largely dominated by emission of 3-4 ring PAHs in the city, while 5-6 ring PAHs were more evenly distributed between city sites and the hill site. During the night a higher fraction of the semivolatile PAHs might have been stored in the soil or sorbed to surfaces. PAH patterns were undistinguishable across the three sites. However, concentrations of more particle-associated substances differed significantly between the urban sites than between one of the urban sites and the rural site (3 σ uncertainty). Time-averaging (on a 24 h-basis) would have masked the significant inter-site differences of half of the substances which were found at different levels (on a 4 h-basis).

  16. A typology of household-level adaptation to coastal flooding and its spatio-temporal patterns.

    PubMed

    Koerth, Jana; Vafeidis, Athanasios T; Carretero, Silvina; Sterr, Horst; Hinkel, Jochen

    2014-01-01

    The predicted sea-level rise and changes in storm surge regimes are expected to lead to an increasing risk of flooding in coastal regions. Accommodation can be an alternative to protection in many areas, with household-level adaptation potentially constituting an important element of such a strategy, as it can significantly reduce costs. To date, a systematic typology of household-level adaptation to coastal flooding does not exist. In order to bridge this gap, we conducted a series of quantitative surveys in different coastal areas in Denmark, Germany and Argentina. We applied a cluster analysis in order to categorise the adaptive behaviour of coastal households. Coastal households were found to cluster in four groups that we term: the comprehensives, the theoreticians, the minimalists and the structurals. With the exception of households focusing on the implementation of high-effort structural measures, our results show the affiliation to these groups to follow a specific temporal sequence. At the same time, large differences in category affiliation exist between the study areas. Risk communication tools can utilise our typology to selectively target specific types of households or to ensure that the information needs of all groups are addressed.

  17. Cotton Defense Induction Patterns Under Spatially, Temporally and Quantitatively Varying Herbivory Levels

    PubMed Central

    Eisenring, Michael; Meissle, Michael; Hagenbucher, Steffen; Naranjo, Steven E.; Wettstein, Felix; Romeis, Jörg

    2017-01-01

    In its defense against herbivores, cotton (Gossypium sp.) relies in part on the production of a set of inducible, non-volatile terpenoids. Under uniform damage levels, in planta allocation of induced cotton terpenoids has been found to be highest in youngest leaves, supporting assumptions of the optimal defense theory (ODT) which predicts that plants allocate defense compounds to tissues depending on their value and the likelihood of herbivore attack. However, our knowledge is limited on how varying, and thus more realistic, damage levels might affect cotton defense organization. We hypothesized that the allocation of terpenoids and densities of terpenoid-storing glands in leaves aligns with assumptions of the ODT, even when plants are subjected to temporally, spatially and quantitatively varying caterpillar (Heliothis virescens) damage. As expected, cotton plants allocated most of their defenses to their youngest leaves regardless of damage location. However, defense induction in older leaves varied with damage location. For at least 14 days after damage treatments ended, plants reallocated defense resources from previously young leaves to newly developed leaves. Furthermore, we observed a positive hyperbolic relationship between leaf damage area and both terpenoid concentrations and gland densities, indicating that cotton plants can fine-tune defense allocation. Although it appears that factors like vascular constraints and chemical properties of individual defense compounds can affect defense levels, our results overall demonstrate that induced defense organization of cotton subjected to varying damage treatments is in alignment with key assumptions of the ODT. PMID:28270830

  18. Ontogenetic, spatial and temporal variation in trophic level and diet of Chukchi Sea fishes

    NASA Astrophysics Data System (ADS)

    Marsh, Jennifer M.; Mueter, Franz J.; Iken, Katrin; Danielson, Seth

    2017-01-01

    Climate warming and increasing development are expected to alter the ecosystem of the Chukchi Sea, including its fish communities. As a component of the Arctic Ecosystem Integrated Survey, we assessed the ontogenetic, spatial and temporal variability of the trophic level and diet of key fish species in the Chukchi Sea using N and C stable isotopes. During August and September of 2012 and 2013, 16 common fish species and two primary, invertebrate consumers were collected from surface, midwater and bottom trawls within the eastern Chukchi Sea. Linear mixed-effects models were used to detect possible variation in the relationship between body length and either δ13C or δ15N values among water masses and years for 13 fish species with an emphasis on Arctic cod (Boreogadus saida). We also examined the fish community isotopic niche space, trophic redundancy, and trophic separation within each water mass as measures of resiliency of the fish food web. Ontogenetic shifts in trophic level and diet were observed for most species and these changes tended to vary by water mass. As they increased in length, most fish species relied more on benthic prey with the exception of three forage fish species (walleye pollock, Gadus chalcogrammus, capelin, Mallotus villosus, and Pacific sandlance, Ammodytes hexapterus). Species that exhibited interannual differences in diet and trophic level were feeding at lower trophic levels and consumed a more pelagic diet in 2012 when zooplankton densities were higher. Fish communities occupied different isotopic niche spaces depending on water mass association. In more northerly Arctic waters, the fish community occupied the smallest isotopic niche space and relied heavily on a limited range of intermediate δ13C prey, whereas in warmer, nutrient-rich Bering Chukchi Summer Water, pelagic prey was important. In the warmest, Pacific-derived coastal water, fish consumed both benthic and pelagic prey. Examining how spatial gradients in trophic

  19. Spatial and temporal variations in coral growth on an inshore turbid reef subjected to multiple disturbances.

    PubMed

    Browne, N K

    2012-06-01

    Coral growth rates (linear extension, density, calcification rates) of three fast-growing corals (Acropora, Montipora, Turbinaria) were studied in situ on Middle Reef, an inshore reef located on the central Great Barrier Reef (GBR), to assess the influence of changing environmental conditions on coral condition and reef growth. Middle Reef is subjected to both local (e.g. high sediment loads) and global (e.g. coral bleaching) disturbance events, usually associated with reduced coral growth. Results indicated, however, that Acropora growth rates (mean linear extension = 6.3 cm/year) were comparable to those measured at similar depths on offshore reefs on the GBR. Montipora linear extension (2.9 cm/year) was greater than estimates available from both clear-water and turbid reefs, and Turbinaria's dense skeleton (1.3 g/cm(3)) may be more resilient to physical damage as ocean pH falls. Coral growth was found to vary between reef habitats due to spatial differences in water motion and sediment dynamics, and temporally with lower calcification rates during the summer months when SSTs (monthly average 29 °C) and rainfall (monthly total >500 mm) were high. In summary, corals on Middle Reef are robust and resilient to their marginal environmental conditions, but are susceptible to anthropogenic disturbances during the summer months.

  20. Initial success of native grasses is contingent on multiple interactions among exotic grass competition, temporal priority, rainfall and site effects.

    PubMed

    Young, Truman P; Zefferman, Emily P; Vaughn, Kurt J; Fick, Stephen

    2014-12-05

    Ecological communities are increasingly being recognized as the products of contemporary drivers and historical legacies that are both biotic and abiotic. In an attempt to unravel multiple layers of ecological contingency, we manipulated (i) competition with exotic annual grasses, (ii) the timing of this competition (temporal priority in arrival/seeding times) and (iii) watering (simulated rainfall) in a restoration-style planting of native perennial grasses. In addition, we replicated this experiment simultaneously at three sites in north-central California. Native perennial grasses had 73-99 % less cover when planted with exotic annuals than when planted alone, but this reduction was greatly ameliorated by planting the natives 2 weeks prior to the exotics. In a drought year, irrigation significantly reduced benefits of early planting so that these benefits resembled those observed in a non-drought year. There were significant differences across the three sites (site effects and interactions) in (i) overall native cover, (ii) the response of natives to competition, (iii) the strength of the temporal priority effect and (iv) the degree to which supplemental watering reduced priority effects. These results reveal the strong multi-layered contingency that underlies even relatively simple communities.

  1. Initial success of native grasses is contingent on multiple interactions among exotic grass competition, temporal priority, rainfall and site effects

    PubMed Central

    Young, Truman P.; Zefferman, Emily P.; Vaughn, Kurt J.; Fick, Stephen

    2015-01-01

    Ecological communities are increasingly being recognized as the products of contemporary drivers and historical legacies that are both biotic and abiotic. In an attempt to unravel multiple layers of ecological contingency, we manipulated (i) competition with exotic annual grasses, (ii) the timing of this competition (temporal priority in arrival/seeding times) and (iii) watering (simulated rainfall) in a restoration-style planting of native perennial grasses. In addition, we replicated this experiment simultaneously at three sites in north-central California. Native perennial grasses had 73–99 % less cover when planted with exotic annuals than when planted alone, but this reduction was greatly ameliorated by planting the natives 2 weeks prior to the exotics. In a drought year, irrigation significantly reduced benefits of early planting so that these benefits resembled those observed in a non-drought year. There were significant differences across the three sites (site effects and interactions) in (i) overall native cover, (ii) the response of natives to competition, (iii) the strength of the temporal priority effect and (iv) the degree to which supplemental watering reduced priority effects. These results reveal the strong multi-layered contingency that underlies even relatively simple communities. PMID:25480888

  2. Geographical, spatial, and temporal distributions of multiple indoor air pollutants in four Chinese provinces

    SciTech Connect

    Yinlong Jin; Zheng Zhou; Gongli He

    2005-12-15

    Exposure to indoor air pollution from household energy use depends on fuel, stove, housing characteristics, and stove use behavior. Three important indoor air pollutants - respirable particles (RPM), carbon monoxide (CO), and sulfur dioxide (SO{sub 2}) were monitored for a total of 457 household-days in four poor provinces in China (Gansu, 129 household-days; Guizhou, 127 household-days; Inner Mongolia, 65 household-days; and Shaanxi, 136 household-days), in two time intervals during the heating season to investigate spatial and temporal patterns of pollution. The two provinces where biomass is the primary fuel (Inner Mongolia and Gansu) had the highest RPM concentrations (719 {mu}g/m{sup 3} in the single cooking/living/bedroom in Inner Mongolia in December and 351-661 {mu}g/m{sup 3} in different rooms and months in Gansu); lower RPM concentration were observed in the primarily coal-burning provinces of Guizhou and Shaanxi (202-352 {mu}g/m{sup 3} and 187-361 {mu}g/m{sup 3} in different rooms and months in Guizhou and Shaanxi, respectively). Inner Mongolia and Gansu also had higher CO concentrations. Among the two primarily coal-burning provinces, Guizhou had lower concentrations of CO than Shaanxi. In the two coal-burning provinces, SO{sub 2} concentrations were substantially higher in Shaanxi than in Guizhou. Relative concentrations in different rooms and provinces indicate that in the northern provinces heating is an important source of exposure to indoor pollutants from energy use. Day-to-day variability of concentrations within individual households, although substantial, was smaller than variation across households. The implications of the findings for designing environmental health interventions in each province are discussed. 21 refs., 3 figs., 6 tabs.

  3. Measuring Science Teachers' Stress Level Triggered by Multiple Stressful Conditions

    ERIC Educational Resources Information Center

    Halim, Lilia; Samsudin, Mohd Ali; Meerah, T. Subahan M.; Osman, Kamisah

    2006-01-01

    The complexity of science teaching requires science teachers to encounter a range of tasks. Some tasks are perceived as stressful while others are not. This study aims to investigate the extent to which different teaching situations lead to different stress levels. It also aims to identify the easiest and most difficult conditions to be regarded…

  4. Temporal Dynamics of Stress-Induced Alternations of Intrinsic Amygdala Connectivity and Neuroendocrine Levels

    PubMed Central

    Quaedflieg, C. W. E. M.; van de Ven, V.; Meyer, T.; Siep, N.; Merckelbach, H.; Smeets, T.

    2015-01-01

    Stress-induced changes in functional brain connectivity have been linked to the etiology of stress-related disorders. Resting state functional connectivity (rsFC) is especially informative in characterizing the temporal trajectory of glucocorticoids during stress adaptation. Using the imaging Maastricht Acute Stress Test (iMAST), we induced acute stress in 39 healthy volunteers and monitored the neuroendocrine stress levels during three runs of resting state functional magnetic resonance imaging (rs-fMRI): before (run 1), immediately following (run 2), and 30min after acute stress (run 3). The iMAST resulted in strong increases in cortisol levels. Whole-brain analysis revealed that acute stress (run 2 - 1) was characterized by changes in connectivity of the amygdala with the ventrolateral prefrontal cortex (vlPFC), ventral posterior cingulate cortex (PCC), cuneus, parahippocampal gyrus, and culmen. Additionally, cortisol responders were characterized by enhanced amygdala - medial prefrontal cortex (mPFC) connectivity. Stress recovery (run 3 - 2) was characterized by altered amygdala connectivity with the dorsolateral prefrontal cortex (dlPFC), ventral and dorsal anterior cingulate cortex (ACC), anterior hippocampal complex, cuneus, and presupplementary motor area (preSMA). Opposite to non-responders, cortisol responders were characterized by enhanced amygdala connectivity with the anterior hippocampal complex and parahippocampal gyrus, and reduced connectivity with left dlPFC, dACC, and culmen during early recovery. Acute stress responding and recovery are thus associated with changes in the functional connectivity of the amygdala network. Our findings show that these changes may be regulated via stress-induced neuroendocrine levels. Defining stress-induced neuronal network changes is pertinent to developing treatments that target abnormal neuronal activity. PMID:25946334

  5. Fission Multiplicity Detection with Temporal Gamma-Neutron Discrimination from Higher-Order Time Correlation Statistics

    SciTech Connect

    Oberer, Richard B.

    2002-10-01

    The current practice of nondestructive assay (NDA) of fissile materials using neutrons is dominated by the 3He detector. This has been the case since the mid 1980s when Fission Multiplicity Detection (FMD) was replaced with thermal well counters and neutron multiplicity counting (NMC). The thermal well counters detect neutrons by neutron capture in the 3He detector subsequent to moderation. The process of detection requires from 30 to 60 μs. As will be explained in Section 3.3 the rate of detecting correlated neutrons (signal) from the same fission are independent of this time but the rate of accidental correlations (noise) are proportional to this time. The well counters are at a distinct disadvantage when there is a large source of uncorrelated neutrons present from (α, n) reactions for example. Plastic scintillating detectors, as were used in FMD, require only about 20 ns to detect neutrons from fission. One thousandth as many accidental coincidences are therefore accumulated. The major problem with the use of fast-plastic scintillation detectors, however, is that both neutrons and gamma rays are detected. The pulses from the two are indistinguishable in these detectors. For this thesis, a new technique was developed to use higher-order time correlation statistics to distinguish combinations of neutron and gamma ray detections in fast-plastic scintillation detectors. A system of analysis to describe these correlations was developed based on simple physical principles. Other sources of correlations from non-fission events are identified and integrated into the analysis developed for fission events. A number of ratios and metric are identified to determine physical properties of the source from the correlations. It is possible to determine both the quantity being measured and detection efficiency from these ratios from a single measurement without a separate calibration. To account for detector dead-time, an alternative analytical technique

  6. Sewage impacts coral reefs at multiple levels of ecological organization.

    PubMed

    Reopanichkul, Pasinee; Schlacher, Thomas A; Carter, R W; Worachananant, Suchai

    2009-09-01

    Against a backdrop of rising sea temperatures and ocean acidification which pose global threats to coral reefs, excess nutrients and turbidity continue to be significant stressors at regional and local scales. Because interventions usually require local data on pollution impacts, we measured ecological responses to sewage discharges in Surin Marine Park, Thailand. Wastewater disposal significantly increased inorganic nutrients and turbidity levels, and this degradation in water quality resulted in substantial ecological shifts in the form of (i) increased macroalgal density and species richness, (ii) lower cover of hard corals, and (iii) significant declines in fish abundance. Thus, the effects of nutrient pollution and turbidity can cascade across several levels of ecological organization to change key properties of the benthos and fish on coral reefs. Maintenance or restoration of ecological reef health requires improved wastewater management and run-off control for reefs to deliver their valuable ecosystems services.

  7. Deciphering phonemes from syllables in blood oxygenation level-dependent signals in human superior temporal gyrus.

    PubMed

    Zhang, Qingtian; Hu, Xiaolin; Luo, Huan; Li, Jianmin; Zhang, Xiaolu; Zhang, Bo

    2016-03-01

    Linguistic units such as phonemes and syllables are important for speech perception. How the brain encodes these units is not well understood. Many neuroimaging studies have found distinct representations of consonant-vowel syllables that shared one phoneme and differed in the other phoneme (e.g. /ba/ and /da/), but it is unclear whether this discrimination ability is due to the neural coding of phonemes or syllables. We combined functional magnetic resonance imaging with multivariate pattern analysis to explore this question. Subjects listened to nine Mandarin syllables in a consonant-vowel form. We successfully decoded phonemes from the syllables based on the blood oxygenation level-dependent signals in the superior temporal gyrus (STG). Specifically, a classifier trained on the cortical patterns elicited by a set of syllables, which contained two phonemes, could distinguish the cortical patterns elicited by other syllables that contained the two phonemes. The results indicated that phonemes have unique representations in the STG. In addition, there was a categorical effect, i.e. the cortical patterns of consonants were similar, and so were the cortical patterns of vowels. Further analysis showed that phonemes exhibited stronger encoding specificity in the mid-STG than in the anterior STG.

  8. Multiple Levels of Degradation Diminish Hemostatic Potential of Thawed Plasma

    PubMed Central

    Matijevic, Nena; Kostousov, Vadim; Wang, Yao-Wei W.; Wade, Charles E.; Wang, Weiwei; Letourneau, Phillip; Hartwell, Elizabeth; Kozar, Rosemary; Ko, Tien; Holcomb, John B.

    2011-01-01

    Background Severe bleeding after injury requires transfusion of blood products, including fresh frozen plasma (FFP). Many centers are keeping thawed plasma (TP) ready for massively transfused patients. According to the American Association of Blood Banks Standards, TP is approved for transfusion up to 5 days after thawing, when stored at 1°C to 6°C. However, there are no clinical data analyzing the effects of the approved 5-day storage on plasma. We hypothesize that the hemostatic potential (HP) of freshly thawed (FFP-0) was superior to plasma stored for 5 days (FFP-5). Methods FFP from 30 single donors were thawed at 37°C and kept at 1°C to 6°C for 5 days. HP was evaluated at day 0 and 5 by measuring kinetics of thrombin generation (TG), kinetics of clot formation by thromboelastography, clotting factors and inhibitors, and cell-derived microparticles (MPs) by flow cytometry. Results When comparing FFP-5 to FFP-0, FFP-5 exhibited only 40% of the potential of FFP-0 for TG (6.2 nM/min vs. 14.3 nM/min, p < 0.0001), a slower clotting response via thromboelastography (reaction time: 4.3 minutes vs. 3.2 minutes, p < 0.0001) and a longer delay in reaching maximum thrombus generation (5.7 minutes vs. 4.6 minutes, p < 0.01). Diminished HP was accompanied by a significant decline in multiple coagulation proteins, including FV, VII, VIII, von Willebrand factor, and free Protein S, by up to 30%, and a decrease of 50% in MP counts. Conclusion The HP and clot forming ability of TP significantly declined with storage. Hence, freshly TP may have a greater ability to restore hemostasis and correct coagulopathy compared with FFP-5. The clinical consequences for transfused patients deserve further exploration. PMID:21217484

  9. How geomorphology and groundwater level affect the spatio-temporal variability of riverine cold water patches?

    NASA Astrophysics Data System (ADS)

    Wawrzyniak, Vincent; Piégay, Hervé; Allemand, Pascal; Vaudor, Lise; Goma, Régis; Grandjean, Philippe

    2016-04-01

    Temperature is a key factor for river ecosystems. In summer, patches of cold water are formed in the river by groundwater seepage. These patches have strong ecological significance and extend to the surface water in a well-mixed riverine system. These patches can serve as thermal refuges for some fish species during summer. In this study, the temporal variability and spatial distribution of cold water patches were explored along a 50 km river reach (the lower Ain River, France) using thermal infrared airborne remote sensing. This study examines a new range of processes acting on cold water patches at different scales that have not previously been touched upon in the literature. Three airborne campaigns were conducted during the summers of 2010, 2011 and 2014. Based on these images, a large number of cold water patches were identified using an automated method. Four types of patches were observed: tributary plumes, cold side channels (former channels or point-bar backwater channels), side seeps (located directly in the river channel) and gravel bar seeps (occurring at the downstream end of gravel bars). Logistic regression was used to analyse the longitudinal distribution of cold water patches according to geomorphologic indicators reflecting current or past fluvial process. Side seeps were found to be related to the local geology. Cold side channels were correlated to contemporary and past lateral river mobility. Gravel bar seeps were related to the current development of bars and are more prevalent in wandering reaches than in single-bed incised and paved reaches. The logistic model was subsequently used to evaluate gravel bar seep variability in the past. The model suggests larger numbers of seeps in the mid-20th century when bar surface area was higher. Interannual variability in the occurrence and spatial extent of side seeps and gravel bar seeps appear to be related to groundwater level fluctuations. Cold side channels exhibited greater interannual stability

  10. Spatial and temporal variability in carbon flux and its correlation with canopy level vegetation indices

    NASA Astrophysics Data System (ADS)

    Hastings, S. J.; Oechel, W. C.; Gamon, J. A.; Salinas, C.

    2003-12-01

    The temporal variability of carbon and water flux of a sarcocaulescent desert shrub ecosystem from July 2001 to September 2003 as measured using the eddy covariance technique in La Paz, Baja California Sur, Mex are described. Our objective was to link site specific measurements of net ecosystem flux with both canopy and satellite remote sensing measurements. Initially, using daily mid day web cam photos, patterns of phenological development and the rate of carbon uptake or loss were found to be linked with the timing and amount of rainfall. When seasonal rains began earlier than normal (2001), loss of carbon via soil respiration was observed with no development of the photosynthetic canopy. Upon the onset of the historical rainy season for the area, seasonal maximum values of net ecosystem flux (-1.5 vs -0.7 gC m-2 day-1 in 2001 and 2002 respectively) was strongly correlated with the amount of rainfall in 2001 and 2002 with precipitation in 2001 approximately twice as large as in 2002 (338 mm vs 124 mm). Spatially explicit measurements of soil respiration and canopy level normalized difference vegetation index were initiated in April of 2003. Mid August rains in 2003 resulted in the anticipated response of the vegetation with respect to development of the canopy. Using the spatial patterns of soil respiration and canopy level NDVI coupled with soil moisture and root biomass sampling, root development was shown to make up a large portion of ecosystem respiration upon the onset of the seasonal rains in 2003. These results are compared with 21 years of regional AVHRR and precipitation for the area as well as MODIS remote sensing outputs.

  11. It is time to integrate: the temporal dynamics of object motion and texture motion integration in multiple object tracking.

    PubMed

    Huff, Markus; Papenmeier, Frank

    2013-01-14

    In multiple-object tracking, participants can track several moving objects among identical distractors. It has recently been shown that the human visual system uses motion information in order to keep track of targets (St. Clair et al., Journal of Vision, 10(4), 1-13). Texture on the surface of an object that moved in the opposite direction to the object itself impaired tracking performance. In this study, we examined the temporal interval at which texture motion and object motion is integrated in dynamic scenes. In two multiple-object tracking experiments, we manipulated the texture motion on the objects: The texture either moved in the same direction as the objects, in the opposite direction, or alternated between the same and opposite direction at varying intervals. In Experiment 1, we show that the integration of object motion and texture motion can take place at intervals as short as 100 ms. In Experiment 2, we show that there is a linear relationship between the proportion of opposite texture motion and tracking performance. We suggest that texture motion might cause shifts in perceived object locations, thus influencing tracking performance.

  12. Synchrony of population dynamics of two vineyard arthropods occurs at multiple spatial and temporal scales.

    PubMed

    De Valpine, Perry; Scranton, Katherine; Ohmart, Clifford P

    2010-10-01

    When populations are synchronized, they rise and fall together. Analysis of population synchrony and its relationship to distance has played a major role in population ecology but has been absent from most studies of managed populations, such as agricultural arthropods. The extent to which populations at different locations are synchronized reflects the relative roles of shared environmental impacts, such as weather, and localizing processes, such as dispersal. The strength and pattern of synchrony, and the processes generating synchrony, have direct management implications. For the first time, we bring together two major paths of population-ecology research: spatial synchrony of population dynamics, which has been studied across birds, mammals, and insects, and spatial ecology of agricultural arthropod populations. We compare and contrast synchrony of two arthropod species, a spider mite and a leafhopper, across a vineyard region spanning 30-km distances, at within-year (weekly) and between-year time scales. Despite the enormous scope of agriculture, such long-term, large-scale data sets suitable for investigating local and regional dynamics are rare. For both species, synchrony is more strongly localized for annual peak abundance across 11 years than it typically is for weekly dynamics within each year's growing season. This suggests that between-year processes such as overwintering merit greater investigation. Within each year, both localized and region-wide synchrony was found for both species, but leafhoppers showed stronger localization than spider mites, corresponding to their longer generation time and stronger dispersal ability. This demonstrates that the overall herbivore dynamics of the system occur at multiple spatial scales and that the importance of different processes generating synchrony varies by species. The analysis includes new spatiotemporal randomization and bootstrap tests that can be applied to many systems. Our results highlight the value

  13. Brain: a complex adaptive structure at multiple levels

    NASA Astrophysics Data System (ADS)

    Klein, Bradley G.

    2001-10-01

    The human brain is comprised of over 100 billion neurons organized into tracts, nuclei, circuits and systems. This provides innumerable elegant abilities that rely on the nervous system to act as a complex adaptive structure (CAS). This property is apparent with respect to overall function, the function of individual neurons and the function of sensory and motor systems. At the overall functional level, the nervous system monitors the environments and can alter that environment. Alterations such as turning on a light switch or changing the diameter of neural vasculature, can improve the performance or chance for survival of the nervous system. Individual neurons can alter the activity of their electrogenic pumps, their rate of transmitter synthesis, their neurotransmitter release and their receptor density in order to maintain optimal functioning in a circuit following changes in their micro-environment. At the systems level, the visual system adjusts the orientation of the eyes or pupillary diameter to receive the highest quality visual information. In the motor system, the myotatic reflex maintains muscle position in the face of changing load, and the gain of the muscle organ responsible for the myotatic reflex can also be automatically adjusted. Internal homeostasis, essential for optimal performance of the nervous system, can be achieved through complex behavioral actions such as feeding. The hypothalamus plays an important role in such behaviors and in the type of sensorimotor integration responsible for the CAS nature of overall nervous system function. Thinking about the CAS characteristics of the nervous system may lead to development of non-biological CAS prostheses for the brain.

  14. Addressing the Underrepresentation of Women in Physics at Multiple Levels

    NASA Astrophysics Data System (ADS)

    Greco, Shannon; Dominguez, Arturo; Ortiz, Deedee; Zwicker, Andrew

    2016-10-01

    APS provides support to several universities and research institutions to host Conferences for Undergraduate Women in Physics (CUWiP). The goal of these Conferences is to provide practical tools and a community to help women persist in physics and STEM careers. This is particularly relevant for the DPP where women make up only 7% of the membership. In January 2017, Princeton University and the Princeton Plasma Physics Laboratory (PPPL) will host a CUWiP. CUWiP and the Science Undergraduate Laboratory Internship (SULI) program expose undergraduates to the variety of possible careers in plasma physics and fusion energy in academia, government labs or private industry. We will report on the success of a number of PPPL programs to engage women at all levels in physics and highlight how programs such as CUWiP and SULI contribute to this goal. Special thanks to the Department of Energy for supporting PPPL's education programs and to APS for supporting the Conference for Undergraduate Women in Physics.

  15. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    NASA Astrophysics Data System (ADS)

    Aksoy, H.; Unal, N. E.; Eris, E.; Yuce, M. I.

    2013-06-01

    In the 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey, has risen up about 2 m. Analysis of the hydrometeorological data shows that change in the water level is related to the water budget of the lake. In this study, stochastic models are proposed for simulating monthly water level data. Two models considering mono- and multiple-trend time series are developed. The models are derived after removal of trend and periodicity in the dataset. Trend observed in the lake water level time series is fitted by mono- and multiple-trend lines. In the so-called mono-trend model, the time series is treated as a whole under the hypothesis that the lake water level has an increasing trend. In the second model (so-called multiple-trend), the time series is divided into a number of segments to each a linear trend can be fitted separately. Application on the lake water level data shows that four segments, each fitted with a trend line, are meaningful. Both the mono- and multiple-trend models are used for simulation of synthetic lake water level time series under the hypothesis that the observed mono- and multiple-trend structure of the lake water level persist during the simulation period. The multiple-trend model is found better for planning the future infrastructural projects in surrounding areas of the lake as it generates higher maxima for the simulated lake water level.

  16. Allopregnanolone Levels are Reduced in Temporal Cortex in Patients with Alzheimer’s Disease Compared to Cognitively Intact Control Subjects

    PubMed Central

    Naylor, Jennifer C.; Kilts, Jason D.; Hulette, Christine M.; Steffens, David C.; Blazer, Dan G.; Ervin, John F.; Strauss, Jennifer L.; Allen, Trina B.; Massing, Mark W.; Payne, Victoria M.; Youssef, Nagy A.; Shampine, Lawrence J.; Marx, Christine E.

    2010-01-01

    Background The neurosteroid allopregnanolone has pronounced neuroprotective actions, increases myelination, and enhances neurogenesis. Evidence suggests that allopregnanolone dysregulation may play a role in the pathophysiology of Alzheimer’s disease (AD) and other neurodegenerative disorders. Our prior data demonstrate that allopregnanolone is reduced in prefrontal cortex in male patients with AD compared to male cognitively intact control subjects, and inversely correlated with neuropathological disease stage (Braak and Braak). We therefore determined if allopregnanolone levels are also reduced in AD patients compared to control subjects in temporal cortex, utilizing a larger set of samples from both male and female patients. In addition, we investigated if neurosteroids are altered in subjects who are APOE4 allele carriers. Methods Allopregnanolone, dehydroepiandrosterone (DHEA), and pregnenolone levels were determined in temporal cortex postmortem samples by gas chromatography/mass spectrometry, preceded by high performance liquid chromatography (40 subjects with AD/41 cognitively intact control subjects). Results Allopregnanolone levels are reduced in temporal cortex in patients with AD (median 2.68 ng/g, n= 40) compared to control subjects (median 5.64 ng/g, n=41), Mann-Whitney p=0.0002, and inversely correlated with Braak and Braak neuropathological disease stage (Spearman r= −0.38, p=0.0004). DHEA and pregnenolone are increased in patients with AD compared to control subjects. Patients carrying an APOE4 allele demonstrate reduced allopregnanolone levels in temporal cortex (Mann-Whitney p=0.04). Conclusions Neurosteroids are altered in temporal cortex in patients with AD and related to neuropathological disease stage. The APOE4 allele is associated with reduced allopregnanolone levels. Neurosteroids may be relevant to the neurobiology and therapeutics of AD. PMID:20488256

  17. From stem cell to erythroblast: regulation of red cell production at multiple levels by multiple hormones.

    PubMed

    Lodish, Harvey; Flygare, Johan; Chou, Song

    2010-07-01

    This article reviews the regulation of production of red blood cells at several levels: (1) the ability of erythropoietin and adhesion to a fibronectin matrix to stimulate the rapid production of red cells by inducing terminal proliferation and differentiation of committed erythroid CFU-E progenitors; (2) the regulated expansion of the pool of earlier BFU-E erythroid progenitors by glucocorticoids and other factors that occurs during chronic anemia or inflammation; and (3) the expansion of thehematopoietic cell pool to produce more progenitors of all hematopoietic lineages.

  18. A Comparison of Item-Level and Scale-Level Multiple Imputation for Questionnaire Batteries

    ERIC Educational Resources Information Center

    Gottschall, Amanda C.; West, Stephen G.; Enders, Craig K.

    2012-01-01

    Behavioral science researchers routinely use scale scores that sum or average a set of questionnaire items to address their substantive questions. A researcher applying multiple imputation to incomplete questionnaire data can either impute the incomplete items prior to computing scale scores or impute the scale scores directly from other scale…

  19. Effects of Multiple Simulation Presentation among Students of Different Anxiety Levels in the Learning of Probability

    ERIC Educational Resources Information Center

    Fong, Soon Fook; Por, Fei Ping; Tang, Ai Ling

    2012-01-01

    The purpose of this study was to investigate the effects of multiple simulation presentation in interactive multimedia are on the achievement of students with different levels of anxiety in the learning of Probability. The interactive multimedia courseware was developed in two different modes, which were Multiple Simulation Presentation (MSP) and…

  20. Temporal Variability of Upper-level Winds at the Eastern Range, Western Range and Wallops Flight Facility

    NASA Technical Reports Server (NTRS)

    Decker, Ryan; Barbre, Robert E.

    2014-01-01

    Space launch vehicles incorporate upper-level wind profiles to determine wind effects on the vehicle and for a commit to launch decision. These assessments incorporate wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the upper-level winds over the time period between the assessment and launch can be mitigated by a statistical analysis of wind change over time periods of interest using historical data from the launch range. Five sets of temporal wind pairs at various times (.75, 1.5, 2, 3 and 4-hrs) at the Eastern Range, Western Range and Wallops Flight Facility were developed for use in upper-level wind assessments. Database development procedures as well as statistical analysis of temporal wind variability at each launch range will be presented.

  1. Surgical care burden in orbito-temporal neurofibromatosis: Multiple procedures and surgical care duration analysis in 47 consecutive adult patients.

    PubMed

    Pessis, Rachel; Lantieri, Laurent; Britto, Jonathan A; Leguerinel, Caroline; Wolkenstein, Pierre; Hivelin, Mikaël

    2015-10-01

    Patients with orbito-temporal neurofibromatosis (OTNF) bear a heavy burden of surgical care. We studied 47 consecutive patients with OTNF from the French Neurofibromatosis 1 Referral Center cohort (n > 900), over a 15-year period to determine the clinical features most likely to predict repeat surgery and longer duration of surgical care. Forty-seven patients (5.2% of the NF1 patients' cohort) underwent 79 procedures with a 4.8 years average follow-up. Soft-tissue surgery had a high revision rate (19/45 patients), skeletal surgery did not (2/13 patients). Transosseous wire canthopexy and facial aesthetic unit remodeling were associated with stable outcome. Ptosis repair carried an unfavorable outcome, particularly in the presence of sphenoid dysplasia. Stable skeletal remodeling was achieved with polyethylene implants and/or cementoplasty. Multiple procedures were undertaken in 70% of patients and were predicted by the NF volume, canthopexy, skeletal dysplasia, or a Jackson's classification 2 and/or 3; but not by declining visual acuity. A classification based upon predictive risk of repeated procedures is proposed: Group 1: Isolated soft tissue infiltration not requiring levator palpebrae or canthal surgery; Group 2: Soft tissue involvement requiring ptosis repair or canthopexy, or NF great axis over 4.5 cm; Group 3: Presence of sphenoid dysplasia with pulsatile proptosis, regardless of visual acuity.

  2. The ability of the auditory system to cope with temporal subsampling depends on the hierarchical level of processing.

    PubMed

    Zoefel, Benedikt; Reddy Pasham, Naveen; Brüers, Sasskia; VanRullen, Rufin

    2015-09-09

    Evidence for rhythmic or 'discrete' sensory processing is abundant for the visual system, but sparse and inconsistent for the auditory system. Fundamental differences in the nature of visual and auditory inputs might account for this discrepancy: whereas the visual system mainly relies on spatial information, time might be the most important factor for the auditory system. In contrast to vision, temporal subsampling (i.e. taking 'snapshots') of the auditory input stream might thus prove detrimental for the brain as essential information would be lost. Rather than embracing the view of a continuous auditory processing, we recently proposed that discrete 'perceptual cycles' might exist in the auditory system, but on a hierarchically higher level of processing, involving temporally more stable features. This proposal leads to the prediction that the auditory system would be more robust to temporal subsampling when applied on a 'high-level' decomposition of auditory signals. To test this prediction, we constructed speech stimuli that were subsampled at different frequencies, either at the input level (following a wavelet transform) or at the level of auditory features (on the basis of LPC vocoding), and presented them to human listeners. Auditory recognition was significantly more robust to subsampling in the latter case, that is on a relatively high level of auditory processing. Although our results do not directly demonstrate perceptual cycles in the auditory domain, they (a) show that their existence is possible without disrupting temporal information to a critical extent and (b) confirm our proposal that, if they do exist, they should operate on a higher level of auditory processing.

  3. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    NASA Astrophysics Data System (ADS)

    Aksoy, H.; Unal, N. E.; Eris, E.; Yuce, M. I.

    2013-02-01

    In 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey has risen up about 2 m. Analysis of the hydrometeorological shows that change in the water level is related to the water budget of the lake. In this study, a stochastic model is generated using the measured monthly water level data of the lake. The model is derived after removal of trend and periodicity in the data set. Trend observed in the lake water level time series is fitted by mono- and multiple-trend lines. For the multiple-trend, the time series is first divided into homogeneous segments by means of SEGMENTER, segmentation software. Four segments are found meaningful practically each fitted with a trend line. Two models considering mono- and multiple-trend time series are developed. The multiple-trend model is found better for planning future development in surrounding areas of the lake.

  4. Influence of Game Evolution and the Phase of Competition on Temporal Game Structure in High-Level Table Tennis Tournaments

    PubMed Central

    Leite, Jorge Vieira de Mello; Barbieri, Fabio Augusto; Miyagi, Willian; Malta, Elvis de Souza

    2017-01-01

    Abstract The aims of this study were: a) to investigate the game temporal structure in high-level table tennis competitions; b) to verify the influence of game evolution in international competitions from 2009 to 2012 (World Table Tennis Championships and the Olympic Games) on game temporal structure; c) to compare game temporal structure according to the phase of competition. Comparisons between the three international tournaments demonstrated that rally duration decreased significantly (p < 0.05) during the analyzed period (2009-2012), while the rest time increased (p < 0.05) from 2009 to 2011, but decreased (p < 0.05) from 2011 to 2012. In the competition phase analysis, it was found that rally duration decreased (p < 0.05) in the quarterfinals in relation to the semifinals and finals, while the rest time increased (p < 0.05) from the quarterfinals to semifinals and finals. Based on our findings and previous literature, we concluded that the performance level, game evolution and the competition phase influenced the game temporal structure of table tennis, considering longer rest periods adopted by elite athletes in relation to non-elite athletes, the reduction in rally duration and an increase in rest time over the 2009-2012 period and through the competition phases (quarterfinals to finals). PMID:28210338

  5. Assessing Interchangeability at Cluster-Levels with Multiple-Informant Data

    PubMed Central

    Luo, Zhehui; Breslau, Joshua; Gardiner, Joseph C.; Chen, Qiaoling; Breslau, Naomi

    2013-01-01

    Studies examining the relationship between neighborhood social disorder and health often rely on multiple informants. Such studies assume interchangeability of the latent constructs derived from multiple-informant data. Existing methods examining this assumption do not clearly delineate the uncertainty at individual levels from that at neighborhood levels. We propose a multi-level variance component factor model that allows this delineation. Data come from a survey of a representative sample of children born between 1983 and 1985 in the inner city of Detroit and nearby middle-class suburbs. Results indicate that the informant-level models tend to exaggerate the effect of places due to differences between persons. Our evaluations of different methodologies lead to the recommendation of the multi-level variance component factor model whenever multiple-informant reports can be aggregated at a neighborhood level. PMID:24038232

  6. Extracting fingerprint of wireless devices based on phase noise and multiple level wavelet decomposition

    NASA Astrophysics Data System (ADS)

    Zhao, Weichen; Sun, Zhuo; Kong, Song

    2016-10-01

    Wireless devices can be identified by the fingerprint extracted from the signal transmitted, which is useful in wireless communication security and other fields. This paper presents a method that extracts fingerprint based on phase noise of signal and multiple level wavelet decomposition. The phase of signal will be extracted first and then decomposed by multiple level wavelet decomposition. The statistic value of each wavelet coefficient vector is utilized for constructing fingerprint. Besides, the relationship between wavelet decomposition level and recognition accuracy is simulated. And advertised decomposition level is revealed as well. Compared with previous methods, our method is simpler and the accuracy of recognition remains high when Signal Noise Ratio (SNR) is low.

  7. Levels of chlorinated, brominated, and perfluorinated contaminants in birds of prey spanning multiple trophic levels.

    PubMed

    Yordy, Jennifer E; Rossman, Sam; Ostrom, Peggy H; Reiner, Jessica L; Bargnesi, Keely; Hughes, Stacy; Elliot, James D

    2013-04-01

    Birds of prey occupy high trophic levels and can consequently bioaccumulate high levels of environmental contaminants. To evaluate exposure to past- and current-use pollutants, we measured legacy contaminants (i.e., polychlorinated biphenyls [PCBs]; organochlorine pesticides, e.g., DDT), contaminants of emerging concern (polybrominated diphenyl ethers [PBDEs]; perfluorinated compounds [PFCs]), and stable isotopes (δ(13)C, δ(15)N) in 26 birds of prey (10 species) from coastal South Carolina (USA) sampled in 2009 and 2010. Nitrogen isotope ratios (δ(15)N) ranged from 5.2% to 13.7%, indicating the birds of prey spanned two to three trophic levels. Legacy contaminant levels were highly variable but generally comparable to levels reported previously for birds of prey in the southeast US, suggesting exposure has not declined substantially over the past 40 yr. Despite their status as newly emerging environmental contaminants, PFC levels were within the same order of magnitude as legacy contaminants. Although PBDEs were less prevalent, levels were among the greatest observed in wildlife to date (∑PBDEs max. 200 μg/g lipid). Relative contaminant profiles also varied between birds of prey utilizing low and high trophic levels; specifically PFCs contributed to a larger proportion of the contaminant burden in birds utilizing high trophic levels, whereas the legacy pesticide mirex was a larger contributor in low-trophic-level birds, indicating that relative exposure is in part dependent on foraging ecology. This study demonstrates that birds of prey continue to face exposure to legacy contaminants as well as newly emerging contaminants at levels of concern.

  8. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    DOE PAGES

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutronmore » fluxes.« less

  9. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    SciTech Connect

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutron fluxes.

  10. Temporal dynamics of direct N2O fluxes from agro-ecosystems in cold climates: importance of year-round measurements in multiple cropping systems

    NASA Astrophysics Data System (ADS)

    Wagner-Riddle, C.; Tenuta, M.

    2014-12-01

    Soil N2O fluxes (direct emissions) are highly variable in time and space due to soil, weather and management drivers. In cold climates, freeze/thaw cycles and short growing seasons can enhance soil N2O production contributing to the temporal variability of fluxes. Year-round measurements of N2O fluxes in multiple cropping systems are needed to decrease the uncertainty of annual emission estimates and to devise mitigation practices for emission reduction in cold climates. We have deployed a micrometeorological flux-gradient approach coupled to a tunable diode laser absorption spectroscopy system at two long-term sites in Canada: Elora, Ontario (2000-2014) and Glenlea, Manitoba (2006-2014). Quasi-simultaneous half-hourly flux measurements on four 4-ha fields within a level and aerodynamically homogeneous landscape were obtained allowing for comparison of crop type and/or management practices within and between years. Annual crops such as corn, soybeans, wheat, and barley received typical inorganic fertilizer and/or manure applications, and best management practices such as timing of application and reduced tillage were studied. Perennial grass-alfalfa hayfields were compared to annual crops during selected time periods. Here we synthesize the long-term datasets from these two sites, and quantify the overall contribution of non-growing season (mainly freeze/thaw cycles) and growing season (mainly nitrogen application) to annual emission totals. Uncertainties of regional estimates for cold-climates will be assessed using these long-term datasets.

  11. Spatio-Temporal Clustering of Hand, Foot, and Mouth Disease at the County Level in Guangxi, China

    PubMed Central

    Xie, Yi-hong; Chongsuvivatwong, Virasakdi; Tang, Zhenzhu; McNeil, Edward B.; Tan, Yi

    2014-01-01

    Background Amid numerous outbreaks of hand, foot and mouth disease (HFMD) in Asia over the past decade, studies on spatio-temporal clustering are limited. Without this information the distribution of severe cases assumed to be sporadic. We analyzed surveillance data with onset dates between 1 May 2008 to 31 October 2013 with the aim to document the spatio-temporal clustering of HFMD cases and severe cases at the county level. Methods Purely temporal and purely spatial descriptive analyses were done. These were followed by a space-time scan statistic for the whole study period and by year to detect the high risk clusters based on a discrete Poisson model. Results The annual incidence rate of HFMD in Guangxi increased whereas the severe cases peaked in 2010 and 2012. EV71 and CoxA16 were alternating viruses. Both HFMD cases and severe cases had a seasonal peak in April to July. The spatio-temporal cluster of HFMD cases were mainly detected in the northeastern, central and southwestern regions, among which three clusters were observed in Nanning, Liuzhou, Guilin city and their neighbouring areas lasting from 1.2 to 2.5 years. The clusters of severe cases were less consistent in location and included around 40–70% of all severe cases in each year. Conclusions Both HFMD cases and severe cases occur in spatio-temporal clusters. The continuous epidemic in Nanning, Liuzhou, Guilin cities and their neighbouring areas and the clusters of severe cases indicate the need for further intensive surveillance. PMID:24505378

  12. Spatial and temporal analysis of extreme sea level and storm surge events around the coastline of the UK

    PubMed Central

    Haigh, Ivan D.; Wadey, Matthew P.; Wahl, Thomas; Ozsoy, Ozgun; Nicholls, Robert J.; Brown, Jennifer M.; Horsburgh, Kevin; Gouldby, Ben

    2016-01-01

    In this paper we analyse the spatial footprint and temporal clustering of extreme sea level and skew surge events around the UK coast over the last 100 years (1915–2014). The vast majority of the extreme sea level events are generated by moderate, rather than extreme skew surges, combined with spring astronomical high tides. We distinguish four broad categories of spatial footprints of events and the distinct storm tracks that generated them. There have been rare events when extreme levels have occurred along two unconnected coastal regions during the same storm. The events that occur in closest succession (<4 days) typically impact different stretches of coastline. The spring/neap tidal cycle prevents successive extreme sea level events from happening within 4–8 days. Finally, the 2013/14 season was highly unusual in the context of the last 100 years from an extreme sea level perspective. PMID:27922630

  13. Spatial and temporal analysis of extreme sea level and storm surge events around the coastline of the UK.

    PubMed

    Haigh, Ivan D; Wadey, Matthew P; Wahl, Thomas; Ozsoy, Ozgun; Nicholls, Robert J; Brown, Jennifer M; Horsburgh, Kevin; Gouldby, Ben

    2016-12-06

    In this paper we analyse the spatial footprint and temporal clustering of extreme sea level and skew surge events around the UK coast over the last 100 years (1915-2014). The vast majority of the extreme sea level events are generated by moderate, rather than extreme skew surges, combined with spring astronomical high tides. We distinguish four broad categories of spatial footprints of events and the distinct storm tracks that generated them. There have been rare events when extreme levels have occurred along two unconnected coastal regions during the same storm. The events that occur in closest succession (<4 days) typically impact different stretches of coastline. The spring/neap tidal cycle prevents successive extreme sea level events from happening within 4-8 days. Finally, the 2013/14 season was highly unusual in the context of the last 100 years from an extreme sea level perspective.

  14. Spatial-temporal analysis of sea level changes in China seas and neighboring oceans by merged altimeter data

    NASA Astrophysics Data System (ADS)

    Xu, Yao; Zhou, Bin; Yu, Zhifeng; Lei, Hui; Sun, Jiamin; Zhu, Xingrui; Liu, Congjin

    2017-01-01

    The knowledge of sea level changes is critical important for social, economic and scientific development in coastal areas. Satellite altimeter makes it possible to observe long term and large scale dynamic changes in the ocean, contiguous shelf seas and coastal zone. In this paper, 1993-2015 altimeter data of Topex/Poseidon and its follow-on missions is used to get a time serious of continuous and homogeneous sea level anomaly gridding product. The sea level rising rate is 0.39 cm/yr in China Seas and the neighboring oceans, 0.37 cm/yr in the Bo and Yellow Sea, 0.29 cm/yr in the East China Sea and 0.40 cm/yr in the South China Sea. The mean sea level and its rising rate are spatial-temporal non-homogeneous. The mean sea level shows opposite characteristics in coastal seas versus open oceans. The Bo and Yellow Sea has the most significant seasonal variability. The results are consistent with in situ data observation by the Nation Ocean Agency of China. The coefficient of variability model is introduced to describe the spatial-temporal variability. Results show that the variability in coastal seas is stronger than that in open oceans, especially the seas off the entrance area of the river, indicating that the validation of altimeter data is less reasonable in these seas.

  15. Landscape level analysis of the spatial and temporal complexity of land-use change

    NASA Astrophysics Data System (ADS)

    Verburg, Peter H.; Veldkamp, A.; Willemen, Louise; Overmars, Koen P.; Castella, Jean-Christophe

    For understanding the causes and effects of changes in land use it is critical to study the interaction between the temporal dynamics and the spatial pattern of land use. Interactions arise from feedbacks in the human-environment system, heterogeneity in the biophysical and human environment and the influence of land-use history. Land-use simulation models can serve as a tool to understand these dynamics in more detail and assess the impact on ecosystem functioning. This chapter presents a spatially explicit modelling approach to explore the spatial and temporal changes in land-use patterns as a function of the specific characteristics of cropping systems and feedbacks between land use and the environment. A case study for Bac Kan province in northern Vietnam is used to test and illustrate the capacity of the model. The results indicate that the model can be used to assess changes in land-use pressure and pattern under different development pathways or scenario conditions. The potential of further developing this approach is discussed.

  16. A spatio-temporal hybrid neural network-Kriging model for groundwater level simulation

    NASA Astrophysics Data System (ADS)

    Tapoglou, Evdokia; Karatzas, George P.; Trichakis, Ioannis C.; Varouchakis, Emmanouil A.

    2014-11-01

    Artificial Neural Networks (ANNs) and Kriging have both been used for hydraulic head simulation. In this study, the two methodologies were combined in order to simulate the spatial and temporal distribution of hydraulic head in a study area. In order to achieve that, a fuzzy logic inference system can also be used. Different ANN architectures and variogram models were tested, together with the use or not of a fuzzy logic system. The developed algorithm was implemented and applied for predicting, spatially and temporally, the hydraulic head in an area located in Bavaria, Germany. The performance of the algorithm was evaluated using leave one out cross validation and various performance indicators were derived. The best results were achieved by using ANNs with two hidden layers, with the use of the fuzzy logic system and by utilizing the power-law variogram. The results obtained from this procedure can be characterized as favorable, since the RMSE of the method is in the order of magnitude of 10-2 m. Therefore this method can be used successfully in aquifers where geological characteristics are obscure, but a variety of other, easily accessible data, such as meteorological data can be easily found.

  17. Ocean warming and seabird communities of the southern California Current System (1987-98): response at multiple temporal scales

    NASA Astrophysics Data System (ADS)

    Hyrenbach, K. David; Veit, Richard R.

    2003-08-01

    Declines in ocean productivity and shifts in species assemblages along the West Coast of North America during the second half of the XXth century have been attributed to the concurrent warming of the California Current. This paper addresses changes in the avifauna off southern California between May 1987 and September 1998, in response to shifting water mass distributions over short (<1 year) and long (interannual) temporal scales. More specifically, our research focuses on the relative importance of distinct foraging guilds and species assemblages with an affinity for warm and cold water. Over the long term, the avifauna off southern California shifted from a 'high-productivity' community typical of eastern boundary upwelling systems, to a 'low-productivity' assemblage similar to those inhabiting the subtropical gyres. Overall seabird abundance decreased; the relative importance of cold-water seabirds that dive in pursuit of prey declined; and warm-water species that feed at the surface and plunge to capture prey became more numerous. These community-level changes are consistent with the northward shifts in species ranges and the declining ocean productivity anticipated as a result of global warming. However, the response of individual taxa with an affinity for warm-water and cold-water conditions has been more difficult to predict, due to differences in species-specific responses to ocean warming. The three cold-water species investigated (Sooty Shearwater Puffinus griseus, Cassin's Auklet Ptychoramphus aleuticus, and Rhinoceros Auklet Cerorhinca monocerata) decreased in abundance during this study. On the other hand, only one of the six warm-water species considered (Pink-footed Shearwater, Puffinus creatopus) increased significantly over the long term. Yet, the warm-water Leach's Storm-petrel ( Oceanodroma leucorhoa) increased between 1987 and 1993, and then declined between 1994 and 1998. Moreover, cross-correlations between seasonally adjusted anomalies of

  18. Optimising threshold levels for information transmission in binary threshold networks: Independent multiplicative noise on each threshold

    NASA Astrophysics Data System (ADS)

    Zhou, Bingchang; McDonnell, Mark D.

    2015-02-01

    The problem of optimising the threshold levels in multilevel threshold system subject to multiplicative Gaussian and uniform noise is considered. Similar to previous results for additive noise, we find a bifurcation phenomenon in the optimal threshold values, as the noise intensity changes. This occurs when the number of threshold units is greater than one. We also study the optimal thresholds for combined additive and multiplicative Gaussian noise, and find that all threshold levels need to be identical to optimise the system when the additive noise intensity is a constant. However, this identical value is not equal to the signal mean, unlike the case of additive noise. When the multiplicative noise intensity is instead held constant, the optimal threshold levels are not all identical for small additive noise intensity but are all equal to zero for large additive noise intensity. The model and our results are potentially relevant for sensor network design and understanding neurobiological sensory neurons such as in the peripheral auditory system.

  19. Advancing analysis of spatio-temporal variations of soil nutrients in the water level fluctuation zone of China's Three Gorges Reservoir using self-organizing map.

    PubMed

    Ye, Chen; Li, Siyue; Yang, Yuyi; Shu, Xiao; Zhang, Jiaquan; Zhang, Quanfa

    2015-01-01

    The ~350 km2 water level fluctuation zone (WLFZ) in the Three Gorges Reservoir (TGR) of China, situated at the intersection of terrestrial and aquatic ecosystems, experiences a great hydrological change with prolonged winter inundation. Soil samples were collected in 12 sites pre- (September 2008) and post submergence (June 2009) in the WLFZ and analyzed for soil nutrients. Self-organizing map (SOM) and statistical analysis including multi-way ANOVA, paired-T test, and stepwise least squares multiple regression were employed to determine the spatio-temporal variations of soil nutrients in relation to submergence, and their correlations with soil physical characteristics. Results showed significant spatial variability in nutrients along ~600 km long shoreline of the TGR before and after submergence. There were higher contents of organic matter, total nitrogen (TN), and nitrate (NO3-) in the lower reach and total phosphorus (TP) in the upper reach that were primarily due to the spatial variations in soil particle size composition and anthropogenic activities. Submergence enhanced soil available potassium (K), while significantly decreased soil N, possibly due to the alterations of soil particle size composition and increase in soil pH. In addition, SOM analysis determined important roles of soil pH value, bulk density, soil particle size (i.e., silt and sand) and nutrients (TP, TK, and AK) on the spatial and temporal variations in soil quality. Our results suggest that urban sewage and agricultural runoffs are primary pollutants that affect soil nutrients in the WLFZ of TGR.

  20. Cascade of Spatio-Temporal Period-Doubling Bifurcations in Connection with the Appearance and Dynamics of Non-Concentric Multiple Double Layers in Plasma

    SciTech Connect

    Dimitriu, D. G.; Ivan, L. M.

    2008-03-19

    Experimental results are presented that reveal a complex route to chaos in plasma, in which a Feigenbaum scenario (cascade of temporal period-doubling bifurcation) develops simultaneously with a cascade of spatial period-doubling bifurcations, in connection with the appearance of a non-concentric multiple double layers structure. The Feigenbaum scenario is identified in the time series of the oscillations of the current through the plasma conductor.

  1. Integrating multiple temporal scales of snowfall, soil, and plant processes at the Great Basin Desert - Sierra Nevada ecotone

    NASA Astrophysics Data System (ADS)

    Loik, M. E.

    2012-12-01

    plant species. Moreover, annual growth ring increments of the conifers Pinus jeffreyi and Pi. contorta were not equally sensitive to snow depth. Results indicate complex interactions between snow depth, soil water, and plant characteristics at multiple temporal scales, which help drive the resilience of plant processes to large interannual variations in snow depth as well as manipulated snow depth. This resilience suggests that this ecotone may be stable in the face of anticipated changes in snow depth.

  2. Evaluation of eight high spatial resolution gridded precipitation products in Adige Basin (Italy) at multiple temporal and spatial scales.

    PubMed

    Duan, Zheng; Liu, Junzhi; Tuo, Ye; Chiogna, Gabriele; Disse, Markus

    2016-12-15

    This study provides a comprehensive evaluation of eight high spatial resolution gridded precipitation products in Adige Basin located in Italy within 45-47.1°N. The Adige Basin is characterized by a complex topography, and independent ground data are available from a network of 101 rain gauges during 2000-2010. The eight products include the Version 7 TRMM (Tropical Rainfall Measuring Mission) Multi-satellite Precipitation Analysis 3B42 product, three products from CMORPH (the Climate Prediction Center MORPHing technique), i.e., CMORPH_RAW, CMORPH_CRT and CMORPH_BLD, PCDR (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record), PGF (Global Meteorological Forcing Dataset for land surface modelling developed by Princeton University), CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) and GSMaP_MVK (Global Satellite Mapping of Precipitation project Moving Vector with Kalman-filter product). All eight products are evaluated against interpolated rain gauge data at the common 0.25° spatial resolution, and additional evaluations at native finer spatial resolution are conducted for CHIRPS (0.05°) and GSMaP_MVK (0.10°). Evaluation is performed at multiple temporal (daily, monthly and annual) and spatial scales (grid and watershed). Evaluation results show that in terms of overall statistical metrics the CHIRPS, TRMM and CMORPH_BLD comparably rank as the top three best performing products, while the PGF performs worst. All eight products underestimate and overestimate the occurrence frequency of daily precipitation for some intensity ranges. All products tend to show higher error in the winter months (December-February) when precipitation is low. Very slight difference can be observed in the evaluation metrics and aspects between at the aggregated 0.25° spatial resolution and at the native finer resolutions (0.05°) for CHIRPS and (0.10°) for GSMaP_MVK products. This study has implications

  3. Medical Temporal-Knowledge Discovery via Temporal Abstraction

    PubMed Central

    Moskovitch, Robert; Shahar, Yuval

    2009-01-01

    Medical knowledge includes frequently occurring temporal patterns in longitudinal patient records. These patterns are not easily detectable by human clinicians. Current knowledge could be extended by automated temporal data mining. However, multivariate time-oriented data are often present at various levels of abstraction and at multiple temporal granularities, requiring a transformation into a more abstract, yet uniform dimension suitable for mining. Temporal abstraction (of both the time and value dimensions) can transform multiple types of point-based data into a meaningful, time-interval-based data representation, in which significant, interval-based temporal patterns can be discovered. We introduce a modular, fast time-interval mining method, KarmaLego, which exploits the transitivity inherent in temporal relations. We demonstrate the usefulness of KarmaLego in finding meaningful temporal patterns within a set of records of diabetic patients; several patterns seem to have a different frequency depending on gender. We also suggest additional uses of the discovered patterns for temporal clustering of the mined population and for classifying multivariate time series. PMID:20351898

  4. Emergence of elevated levels of multiple infections in spatial host-virus dynamics

    NASA Astrophysics Data System (ADS)

    Taylor, Bradford; Penington, Catherine; Weitz, Joshua

    Bacteria are subject to infection and potentially to multiple simultaneous infections by viruses. Multiply infected hosts have altered life-history traits (e.g., viral burst size) and evolutionary rates (e.g., viral recombination). Yet our understanding of multiple infections of microbes is limited to lab settings where the ratio of inoculant viruses to hosts is controlled. In contrast, rates of multiple infection in natural environments are unknown. Here, we develop an individual based model to quantify rates of multiple infections by a single viral type. We explore different dispersal regimes by varying the viral adsorption rate. High dispersal regimes lead to spatial dynamics and rates of multiple infection equivalent to predictions from mean field models. Local clustering of bacterial hosts occurs for low dispersal. Comparing to mean field, the clustering leads to increased rates of multiple infection and fatter tails in the distribution of the number of internal viruses. The emergence of increased colocalization of viruses with infected hosts leads to these deviations. We show these deviations result from the wave-like spread of viruses when invading clusters of bacteria. Our work represents a key step in understanding the population-level effects of multiple infections.

  5. Trace element levels in pine snake hatchlings: tissue and temporal differences.

    PubMed

    Burger, J

    1992-02-01

    Trace element levels have seldom been examined in reptiles, although some large snakes are high on the trophic level pyramid. Lead, cadmium, mercury, selenium, chromium and manganese levels were examined in skin and whole body tissue of pine snakes (Pituophis melanoleucus) from the New Jersey Pine Barrens between 1985-1990. Depending on the element, variations in levels were primarily explained by year and tissue, and not by sex or location. There were significantly higher levels of lead, mercury, and chromium in the skin compared to the whole body tissue, suggesting that the frequent shedding of skin can act as a method of toxic metal excretion by snakes. Manganese and selenium levels were significantly higher in the body compared to the skin.

  6. Temporal Processing of Vibratory Communication Signals at the Level of Ascending Interneurons in Nezara viridula (Hemiptera: Pentatomidae)

    PubMed Central

    Zorović, Maja

    2011-01-01

    During mating, males and females of N. viridula (Heteroptera: Pentatomidae) produce sex- and species-specific calling and courtship substrate-borne vibratory signals, grouped into songs. Recognition and localization of these signals are fundamental for successful mating. The recognition is mainly based on the temporal pattern, i.e. the amplitude modulation, while the frequency spectrum of the signals usually only plays a minor role. We examined the temporal selectivity for vibratory signals in four types of ascending vibratory interneurons in N. viridula. Using intracellular recording and labelling technique, we analyzed the neurons' responses to 30 pulse duration/interval duration (PD/ID) combinations. Two response arrays were created for each neuron type, showing the intensity of the responses either as time-averaged spike counts or as peak instantaneous spike rates. The mean spike rate response arrays showed preference of the neurons for short PDs (below 600 ms) and no selectivity towards interval duration; while the peak spike rate response arrays exhibited either short PD/long ID selectivity or no selectivity at all. The long PD/short ID combinations elicited the weakest responses in all neurons tested. No response arrays showed the receiver preference for either constant period or duty cycle. The vibratory song pattern selectivity matched the PD of N. viridula male vibratory signals, thus pointing to temporal filtering for the conspecific vibratory signals already at level of the ascending interneurons. In some neurons the responses elicited by the vibratory stimuli were followed by distinct, regular oscillations of the membrane potential. The distance between the oscillation peaks matched the temporal structure of the male calling song, indicating a possible resonance based mechanism for signal recognition. PMID:22053216

  7. Temporal and Spatial prediction of groundwater levels using Artificial Neural Networks, Fuzzy logic and Kriging interpolation.

    NASA Astrophysics Data System (ADS)

    Tapoglou, Evdokia; Karatzas, George P.; Trichakis, Ioannis C.; Varouchakis, Emmanouil A.

    2014-05-01

    The purpose of this study is to examine the use of Artificial Neural Networks (ANN) combined with kriging interpolation method, in order to simulate the hydraulic head both spatially and temporally. Initially, ANNs are used for the temporal simulation of the hydraulic head change. The results of the most appropriate ANNs, determined through a fuzzy logic system, are used as an input for the kriging algorithm where the spatial simulation is conducted. The proposed algorithm is tested in an area located across Isar River in Bayern, Germany and covers an area of approximately 7800 km2. The available data extend to a time period from 1/11/2008 to 31/10/2012 (1460 days) and include the hydraulic head at 64 wells, temperature and rainfall at 7 weather stations and surface water elevation at 5 monitoring stations. One feedforward ANN was trained for each of the 64 wells, where hydraulic head data are available, using a backpropagation algorithm. The most appropriate input parameters for each wells' ANN are determined considering their proximity to the measuring station, as well as their statistical characteristics. For the rainfall, the data for two consecutive time lags for best correlated weather station, as well as a third and fourth input from the second best correlated weather station, are used as an input. The surface water monitoring stations with the three best correlations for each well are also used in every case. Finally, the temperature for the best correlated weather station is used. Two different architectures are considered and the one with the best results is used henceforward. The output of the ANNs corresponds to the hydraulic head change per time step. These predictions are used in the kriging interpolation algorithm. However, not all 64 simulated values should be used. The appropriate neighborhood for each prediction point is constructed based not only on the distance between known and prediction points, but also on the training and testing error of

  8. Temporal characterization of mercury accumulation at different trophic levels and implications for metal biomagnification along a coastal food web.

    PubMed

    Cardoso, P G; Pereira, E; Duarte, A C; Azeiteiro, U M

    2014-10-15

    The main goal of this study was to assess temporal mercury variations along an estuarine food web to evaluate the mercury contamination level of the system and the risks that humans are exposed to, due to mercury biomagnification. The highest mercury concentrations in the sediments and primary producers (macrophytes) were observed during winter sampling. Instead, the highest mercury concentrations in the water, suspended particulate matter as well as in the zooplanktonic and suprabenthic communities were observed during summer sampling. Evidences of mercury biomagnification along the food web were corroborated by the positive biomagnification factors, particularly for omnivorous macrobenthic species. Comparing the mercury levels at distinct components with several environmental quality criteria it suggests that sediments, water and edible species (e.g., bivalve Scrobicularia plana and the crustacean Carcinus maenas) presented higher mercury levels than the values accepted by legislation which represent a matter of concern for the environment and human health.

  9. Coh-Metrix Measures Text Characteristics at Multiple Levels of Language and Discourse

    ERIC Educational Resources Information Center

    Graesser, Arthur C.; McNamara, Danielle S.; Cai, Zhiqang; Conley, Mark; Li, Haiying; Pennebaker, James

    2014-01-01

    Coh-Metrix analyzes texts on multiple measures of language and discourse that are aligned with multilevel theoretical frameworks of comprehension. Dozens of measures funnel into five major factors that systematically vary as a function of types of texts (e.g., narrative vs. informational) and grade level: narrativity, syntactic simplicity, word…

  10. Multiple-Choice Exams: An Obstacle for Higher-Level Thinking in Introductory Science Classes

    ERIC Educational Resources Information Center

    Stanger-Hall, Kathrin F.

    2012-01-01

    Learning science requires higher-level (critical) thinking skills that need to be practiced in science classes. This study tested the effect of exam format on critical-thinking skills. Multiple-choice (MC) testing is common in introductory science courses, and students in these classes tend to associate memorization with MC questions and may not…

  11. A Multivariate Model for the Meta-Analysis of Study Level Survival Data at Multiple Times

    ERIC Educational Resources Information Center

    Jackson, Dan; Rollins, Katie; Coughlin, Patrick

    2014-01-01

    Motivated by our meta-analytic dataset involving survival rates after treatment for critical leg ischemia, we develop and apply a new multivariate model for the meta-analysis of study level survival data at multiple times. Our data set involves 50 studies that provide mortality rates at up to seven time points, which we model simultaneously, and…

  12. Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria

    PubMed Central

    Dybwad, Marius; Skogan, Gunnar

    2014-01-01

    Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103 CFU m−3 and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents. PMID:24162566

  13. Spatial and Temporal Patterns of SMAP Brightness Temperatures for Use in Level 1 TB Characterization

    NASA Astrophysics Data System (ADS)

    Kim, E. J.

    2015-12-01

    1. IntroductionThe recent launch of NASA's Soil Moisture Active Passive (SMAP) mission [Entekhabi, et al] has opened the door to improved brightness temperature (TB) calibration of satellite L-band microwave radiometers, through the use of SMAP's lower noise performance and better immunity to man-made interference (vs. ESA's Soil Moisture Ocean Salinity (SMOS) mission [Kerr, et al]), better spatial resolution (vs. NASA's Aquarius sea surface salinity mission [Le Vine, et al]), and cleaner antenna pattern (vs. SMOS). All three radiometers use/used large homogeneous places on Earth's surface as calibration targets—parts of the ocean, Antarctica, and tropical forests. Despite the recent loss of Aquarius data, there is still hope for creating a longer-term L-band data set that spans the timeframe of all 3 missions. 2. Description of Analyses and Expected Results In this paper, we analyze SMAP brightness temperature data to quantify the spatial and temporal characteristics of external target areas in the oceans, Antarctica, forests, and other areas. Existing analyses have examined these targets in terms of averages, standard deviations, and other basic statistics (for Aquarius & SMOS as well). This paper will approach the problem from a signal processing perspective. Coupled with the use of SMAP's novel RFI-mitigated TBs, and the aforementioned lower noise and cleaner antenna pattern, it is expected that of the 3 L-band missions, SMAP should do the best job of characterizing such external targets. The resulting conclusions should be useful to extract the best possible TB calibration from all 3 missions, helping to inter-compare the TB from the 3 missions, and to eventually inter-calibrate the TBs into a single long-term dataset.

  14. Higher Levels of Multiple Paternities Increase Seedling Survival in the Long-Lived Tree Eucalyptus gracilis

    PubMed Central

    Breed, Martin F.; Christmas, Matthew J.; Lowe, Andrew J.

    2014-01-01

    Studying associations between mating system parameters and fitness in natural populations of trees advances our understanding of how local environments affect seed quality, and thereby helps to predict when inbreeding or multiple paternities should impact on fitness. Indeed, for species that demonstrate inbreeding avoidance, multiple paternities (i.e. the number of male parents per half-sib family) should still vary and regulate fitness more than inbreeding – named here as the ‘constrained inbreeding hypothesis’. We test this hypothesis in Eucalyptus gracilis, a predominantly insect-pollinated tree. Fifty-eight open-pollinated progeny arrays were collected from trees in three populations. Progeny were planted in a reciprocal transplant trial. Fitness was measured by family establishment rates. We genotyped all trees and their progeny at eight microsatellite loci. Planting site had a strong effect on fitness, but seed provenance and seed provenance × planting site did not. Populations had comparable mating system parameters and were generally outcrossed, experienced low biparental inbreeding and high levels of multiple paternity. As predicted, seed families that had more multiple paternities also had higher fitness, and no fitness-inbreeding correlations were detected. Demonstrating that fitness was most affected by multiple paternities rather than inbreeding, we provide evidence supporting the constrained inbreeding hypothesis; i.e. that multiple paternity may impact on fitness over and above that of inbreeding, particularly for preferentially outcrossing trees at life stages beyond seed development. PMID:24587373

  15. Higher levels of multiple paternities increase seedling survival in the long-lived tree Eucalyptus gracilis.

    PubMed

    Breed, Martin F; Christmas, Matthew J; Lowe, Andrew J

    2014-01-01

    Studying associations between mating system parameters and fitness in natural populations of trees advances our understanding of how local environments affect seed quality, and thereby helps to predict when inbreeding or multiple paternities should impact on fitness. Indeed, for species that demonstrate inbreeding avoidance, multiple paternities (i.e. the number of male parents per half-sib family) should still vary and regulate fitness more than inbreeding--named here as the 'constrained inbreeding hypothesis'. We test this hypothesis in Eucalyptus gracilis, a predominantly insect-pollinated tree. Fifty-eight open-pollinated progeny arrays were collected from trees in three populations. Progeny were planted in a reciprocal transplant trial. Fitness was measured by family establishment rates. We genotyped all trees and their progeny at eight microsatellite loci. Planting site had a strong effect on fitness, but seed provenance and seed provenance × planting site did not. Populations had comparable mating system parameters and were generally outcrossed, experienced low biparental inbreeding and high levels of multiple paternity. As predicted, seed families that had more multiple paternities also had higher fitness, and no fitness-inbreeding correlations were detected. Demonstrating that fitness was most affected by multiple paternities rather than inbreeding, we provide evidence supporting the constrained inbreeding hypothesis; i.e. that multiple paternity may impact on fitness over and above that of inbreeding, particularly for preferentially outcrossing trees at life stages beyond seed development.

  16. The initial rise method extended to multiple trapping levels in thermoluminescent materials.

    PubMed

    Furetta, C; Guzmán, S; Ruiz, B; Cruz-Zaragoza, E

    2011-02-01

    The well known Initial Rise Method (IR) is commonly used to determine the activation energy when only one glow peak is presented and analysed in the phosphor materials. However, when the glow peak is more complex, a wide peak and some holders appear in the structure. The application of the Initial Rise Method is not valid because multiple trapping levels are considered and then the thermoluminescent analysis becomes difficult to perform. This paper shows the case of a complex glow curve structure as an example and shows that the calculation is also possible using the IR method. The aim of the paper is to extend the well known Initial Rise Method (IR) to the case of multiple trapping levels. The IR method is applied to minerals extracted from Nopal cactus and Oregano spices because the thermoluminescent glow curve's shape suggests a trap distribution instead of a single trapping level.

  17. Multiple external hazards compound level 3 PSA methods research of nuclear power plant

    NASA Astrophysics Data System (ADS)

    Wang, Handing; Liang, Xiaoyu; Zhang, Xiaoming; Yang, Jianfeng; Liu, Weidong; Lei, Dina

    2017-01-01

    2011 Fukushima nuclear power plant severe accident was caused by both earthquake and tsunami, which results in large amount of radioactive nuclides release. That accident has caused the radioactive contamination on the surrounding environment. Although this accident probability is extremely small, once such an accident happens that is likely to release a lot of radioactive materials into the environment, and cause radiation contamination. Therefore, studying accidents consequences is important and essential to improve nuclear power plant design and management. Level 3 PSA methods of nuclear power plant can be used to analyze radiological consequences, and quantify risk to the public health effects around nuclear power plants. Based on multiple external hazards compound level 3 PSA methods studies of nuclear power plant, and the description of the multiple external hazards compound level 3 PSA technology roadmap and important technical elements, as well as taking a coastal nuclear power plant as the reference site, we analyzed the impact of off-site consequences of nuclear power plant severe accidents caused by multiple external hazards. At last we discussed the impact of off-site consequences probabilistic risk studies and its applications under multiple external hazards compound conditions, and explained feasibility and reasonableness of emergency plans implementation.

  18. Improving the Readability of ASR Results for Lectures Using Multiple Hypotheses and Sentence-Level Knowledge

    NASA Astrophysics Data System (ADS)

    Fujii, Yasuhisa; Yamamoto, Kazumasa; Nakagawa, Seiichi

    This paper presents a novel method for improving the readability of automatic speech recognition (ASR) results for classroom lectures. Because speech in a classroom is spontaneous and contains many ill-formed utterances with various disfluencies, the ASR result should be edited to improve the readability before presenting it to users, by applying some operations such as removing disfluencies, determining sentence boundaries, inserting punctuation marks and repairing dropped words. Owing to the presence of many kinds of domain-dependent words and casual styles, even state-of-the-art recognizers can only achieve a 30-50% word error rate for speech in classroom lectures. Therefore, a method for improving the readability of ASR results is needed to make it robust to recognition errors. We can use multiple hypotheses instead of the single-best hypothesis as a method to achieve a robust response to recognition errors. However, if the multiple hypotheses are represented by a lattice (or a confusion network), it is difficult to utilize sentence-level knowledge, such as chunking and dependency parsing, which are imperative for determining the discourse structure and therefore imperative for improving readability. In this paper, we propose a novel algorithm that infers clean, readable transcripts from spontaneous multiple hypotheses represented by a confusion network while integrating sentence-level knowledge. Automatic and manual evaluations showed that using multiple hypotheses and sentence-level knowledge is effective to improve the readability of ASR results, while preserving the understandability.

  19. Spatial data aggregation for spatio-temporal individual-level models of infectious disease transmission.

    PubMed

    Deeth, Lorna E; Deardon, Rob

    2016-05-01

    A class of complex statistical models, known as individual-level models, have been effectively used to model the spread of infectious diseases. These models are often fitted within a Bayesian Markov chain Monte Carlo framework, which can have a sig nificant computational expense due to the complex nature of the likelihood function associated with this class of models. Increases in population size or duration of the modeled epidemic can contribute to this computational burden. Here, we explore the effect of reducing this computational expense by aggregating the data into spatial clusters, and therefore reducing the overall population size. Individual-level models, reparameterized to account for this aggregation effect, may then be fitted to the spatially aggregated data. The ability of two reparameterized individual-level models, when fitted to this reduced data set, to identify a covariate effect is investigated through a simulation study.

  20. Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker

    PubMed Central

    Harris, Christopher M.; Madliger, Christine L.; Love, Oliver P.

    2016-01-01

    The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows (Tachycineta bicolor) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications. PMID:27933163

  1. Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker.

    PubMed

    Harris, Christopher M; Madliger, Christine L; Love, Oliver P

    2016-01-01

    The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows (Tachycineta bicolor) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications.

  2. A genome-wide study of DNA methylation patterns and gene expression levels in multiple human and chimpanzee tissues.

    PubMed

    Pai, Athma A; Bell, Jordana T; Marioni, John C; Pritchard, Jonathan K; Gilad, Yoav

    2011-02-01

    The modification of DNA by methylation is an important epigenetic mechanism that affects the spatial and temporal regulation of gene expression. Methylation patterns have been described in many contexts within and across a range of species. However, the extent to which changes in methylation might underlie inter-species differences in gene regulation, in particular between humans and other primates, has not yet been studied. To this end, we studied DNA methylation patterns in livers, hearts, and kidneys from multiple humans and chimpanzees, using tissue samples for which genome-wide gene expression data were also available. Using the multi-species gene expression and methylation data for 7,723 genes, we were able to study the role of promoter DNA methylation in the evolution of gene regulation across tissues and species. We found that inter-tissue methylation patterns are often conserved between humans and chimpanzees. However, we also found a large number of gene expression differences between species that might be explained, at least in part, by corresponding differences in methylation levels. In particular, we estimate that, in the tissues we studied, inter-species differences in promoter methylation might underlie as much as 12%-18% of differences in gene expression levels between humans and chimpanzees.

  3. Spatio-temporal gait characteristics of level and vertical locomotion in a ground-dwelling and a climbing gecko.

    PubMed

    Zaaf, A; Van Damme, R; Herrel, A; Aerts, P

    2001-04-01

    The effects of incline (vertical versus horizontal) on spatio-temporal gait characteristics (stride and step length, frequency, duty factor, degree of sprawling) were measured over a range of speeds in a ground-dwelling (Eublepharis macularius) and a climbing (Gekko gecko) species of gecko. Surprisingly, the climbing species also performs very well when moving on the horizontal substratum. In the present experiments, climbing speeds ranged from 0.6 to 1.2 m s(-1), whereas speeds for level locomotion were between 0.6 and 1.8 m s(-1). In contrast, the vertical climbing capacities of the ground-dweller are limited (speeds below 0.1 m s(-1 )versus level speeds between 0.2 and 1.1 m s(-1)). In general, we demonstrate that very little adjustment in gait characteristics is made by either species when they are forced to move on their non-habitual substratum. Moreover, gait characteristics differ little between the species despite the clear differences in ecological niche. Higher level or climbing speeds are realized mainly (or exclusively in the case of level locomotion in G. gecko) by increasing stride frequency. Stride lengths and duty factors vary with speed in the ground-dweller, but not in the climbing species. Step length and the degree of sprawling are speed-independent (except for hind-limb sprawling in G. gecko on the level). It is argued that this common strategy suits climbing (fixed spatial variables, no floating phases) rather than level locomotion.

  4. Mercury levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes.

    PubMed

    Blukacz-Richards, E Agnes; Visha, Ariola; Graham, Matthew L; McGoldrick, Daryl L; de Solla, Shane R; Moore, David J; Arhonditsis, George B

    2017-04-01

    Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow smelt (Osmerus mordax). Trends were quantified with dynamic linear models, which provided time-variant rates of change of mercury concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, mercury levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in Lake Erie and two sites in Lake Ontario. Similar trend reversals in the 2000s were observed for lake trout in Lake Superior and at a single station in Lake Ontario. Mercury levels in lake trout continued to slowly decline at all of the remaining stations, except for Lake Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and rainbow smelt in Lake Superior and Lake Ontario, but also pinpoints the likelihood of a trophic decoupling in Lake Huron and Lake Erie. Continued monitoring of mercury levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications.

  5. Temporal and spatial variations of radioactive cesium levels in Northeast Japan following the Fukushima nuclear accident.

    PubMed

    Arai, Takaomi

    2016-10-01

    Radioactive emissions into the environment from the Fukushima Daiichi Nuclear Power Plant accident led to global contamination. Radionuclides such as (131)I, (134)Cs, and (137)Cs were further transported to North America and Europe. Thus, the Fukushima Daiichi Nuclear Power Plant accident is a global concern for both human health and the ecosystem because a number of countries ban or impose restrictions the import of Japanese products. In the present study, three-year (May 2011 to May 2014) fluctuations and accumulations of Cs, (134)Cs, and (137)Cs in two salmonid fish, white-spotted char and masu salmon were examined in Northeast Japan. The total Cs, (134)Cs, and (137)Cs levels in the fish gradually decreased throughout the three-year studied period after the Fukushima Daiichi Nuclear Power Plant accident; however, higher levels (more than 100 Bq kg(-1)) were still detected in the Fukushima prefecture and neighboring prefectures in Japan 3 years after the Fukushima Daiichi Nuclear Power Plant accident. Spatial radiocesium levels gradually decreased with increasing distance from the Fukushima Daiichi Nuclear Power Plant (Fukushima prefecture). The radiocesium levels facing the Pacific Ocean area were generally higher than those facing the Sea of Japan area. These results suggest that radionuclides from Fukushima Daiichi Nuclear Power Plant are still widely distributed and remain in the natural environment in Northeast Japan.

  6. Contamination status of persistent organochlorines in human breast milk from Japan: recent levels and temporal trend.

    PubMed

    Kunisue, Tatsuya; Muraoka, Masayoshi; Ohtake, Masako; Sudaryanto, Agus; Minh, Nguyen Hung; Ueno, Daisuke; Higaki, Yumi; Ochi, Miyuki; Tsydenova, Oyuna; Kamikawa, Satoko; Tonegi, Tomoyuki; Nakamura, Yumi; Shimomura, Hiroshi; Nagayama, Junya; Tanabe, Shinsuke

    2006-08-01

    Contamination levels of persistent organochlorines (OCs) such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), and chlordane compounds (CHLs) was examined in human breast milk collected during 2001-2004 from Fukuoka prefecture in Japan. The concentrations of OCs such as dioxins and related compounds, DDTs, CHLs and HCB in human breast milk from primiparae were comparable to or slightly higher than the data obtained during 1998, indicating that the levels of these contaminants in Japanese human breast milk have not decreased since 1998 and Japanese are continuously exposed to these chemicals, presumably via fish intake. In addition, OC levels in human breast milk from primiparae were significantly higher than those from multiparae, implying elimination of OCs via lactation. Furthermore, significant positive correlations were observed between levels of OCs in human breast milk and the age of primiparae. These results indicate that the mothers with higher age may transfer higher amounts of OCs to the first infant than to the infants born afterwards through breast-feeding, and hence the first born children might be at higher risk by OCs.

  7. Cotton defense induction patterns under spatially, temporally and quantitatively varying herbivory levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The optimal defense theory (ODT) predicts that plants allocate defense compounds to their tissues depending on its value and the likelihood of herbivore attack. Whereas ODT has been confirmed for static damage levels it remains poorly understood if ODT holds true for defense organization of inducibl...

  8. A satellite-based analysis of temporal dynamics in tropospheric nitrogen dioxide levels over large urban agglomerations worldwide

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; van der A, Ronald; Valdebenito, Alvaro

    2014-05-01

    Satellite observations allow for a consistent perspective on tropospheric nitrogen dioxide at a global scale and their operational status facilitates studies on multi-annual to decadal temporal dynamics. Utilizing close to a decade of data from the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and the Ozone Monitoring Instrument (OMI) sensors, we present in this contribution a global analysis of the temporal dynamics in tropospheric nitrogen dioxide over the worlds' major urban agglomerations during the last 10 years. The results indicate that while levels of nitrogen dioxide have been slowly declining in most areas of the United States and Europe over the last decade, very rapid increases in tropospheric nitrogen dioxide can be observed over many megacities and other large urban agglomerations throughout most of Asia, often with highly significant trends. Particularly in Eastern China, increases of 10 to 20 percent per year are quite widespread. Some of the large urban agglomerations with the most rapid increase in nitrogen dioxide pollution are Dhaka in Bangladesh, Kabul in Afghanistan, and Tianjin in China, and these are investigated in more detail. An inter-comparison of trends derived separately from SCIAMACHY and OMI shows that in terms of spatial patterns the resulting trends agree quite well between the two instruments, particularly in the more polluted areas. However, at the individual grid cell level substantial differences can be found. In addition, the satellite-based trends in tropospheric nitrogen dioxide levels were compared to those obtained from the European Monitoring and Evaluation Programme (EMEP) chemical transport model over the same time period, and furthermore sampling the model at the same time of day as the satellite overpass, thus eliminating the impact of the distinct diurnal cycle of nitrogen dioxide. While generally a good correspondence in the trends has been found between the two data sources

  9. Temporal fluctuation of the lead level in the cord blood of neonates in Taipei

    SciTech Connect

    Hwang, Y.H.; Wang, J.D. )

    1990-01-01

    From August 1985 to September 1987, 9,502 cord blood samples were obtained from the Taipei Municipal Maternal and Child Hospital. A total of 205 cord blood samples chosen randomly from newborns without parental exposure to lead were analyzed by flameless atomic absorption spectrophotometry. The average blood lead level was .36 +/- .11 mumol/l (7.48 +/- 2.25 micrograms/dl). A similar analysis was performed on samples obtained from 160 newborns whose fathers had occupational lead exposure. In both groups, the average concentration of lead in cord blood in the summer was statistically greater than that in the winter. Air lead and total amount of lead in gasoline consumed in Taipei appeared to be associated with this seasonal fluctuation in the average lead level of cord blood. After considering alternative sources, we conclude that the seasonal fluctuation of cord blood lead is probably influenced by air lead produced from the combustion of gasoline.

  10. The Spatial and Temporal Variability of Sea Level Change along the North American East Coast

    NASA Astrophysics Data System (ADS)

    Davis, J. L.; Han, D.; Oh, B.; Chen, C.

    2014-12-01

    Understanding the nature of sea-level change (SLC) is of paramount importance to, and a significant aspect of the future well being of, coastal towns and ecosystems. The east coast of North America is particularly susceptible to the impacts of SLC because its high economic productivity and population density compound the possible damage that could occur to the region. Moreover, predictions regarding the near-term and long-term future effects of SLC in this region are inconclusive because there is uncertainty regarding its long-term causes. As a result, the findings of a study of the various components of sea-level change on the U.S. East Coast will be presented. A model for SLC on the East Coast will be developed consisting of SLC due to thermosteric changes, glacial isostatic adjustment, and gravitationally self-consistent calculations for SLC due to present-day melting from Greenland and other areas from GRACE data. Tide gauges along the coast will be used to provide observational constraints on SLC. The models will include scenarios for the time-dependence of SLC. The comparison between data and models will be used to assess the current level of understanding of SLC in this region on a wide range of timescales.

  11. Spatio-temporal analysis of recent groundwater-level trends in the Red River Delta, Vietnam

    NASA Astrophysics Data System (ADS)

    Bui, Duong Du; Kawamura, Akira; Tong, Thanh Ngoc; Amaguchi, Hideo; Nakagawa, Naoko

    2012-12-01

    A groundwater-monitoring network has been in operation in the Red River Delta, Vietnam, since 1995. Trends in groundwater level (1995-2009) in 57 wells in the Holocene unconfined aquifer and 63 wells in the Pleistocene confined aquifer were determined by applying the non-parametric Mann-Kendall trend test and Sen's slope estimator. At each well, 17 time series (e.g. annual, seasonal, monthly), computed from the original data, were analyzed. Analysis of the annual groundwater-level means revealed that 35 % of the wells in the unconfined aquifer showed downward trends, while about 21 % showed upward trends. On the other hand, confined-aquifer groundwater levels experienced downward trends in almost all locations. Spatial distributions of trends indicated that the strongly declining trends (>0.3 m/year) were mainly found in urban areas around Hanoi where there is intensive abstraction of groundwater. Although the trend results for most of the 17 time series at a given well were quite similar, different trend patterns were detected in several. The findings reflect unsustainable groundwater development and the importance of maintaining groundwater monitoring and a database in the Delta, particularly in urban areas.

  12. Serum Vitamin B12 and thyroid hormone levels in Saudi patients with multiple sclerosis

    PubMed Central

    Al-Khamis, Fahd A.

    2016-01-01

    Objectives: To determine the relationship between Vitamin B12 levels and thyroid hormones in patients with multiple sclerosis (MS). Materials and Methods: One hundred and ten patients with MS were recruited for this study after Institutional Review Board approval. All patients signed a written informed consent form and donated a single blood sample. Plasma Vitamin B12 levels, triiodothyronine (T3), and thyroxine (T4) hormone levels were measured. Data were analyzed using the Statistical Package for Social Sciences (SPSS) software. Results: Analysis of Vitamin B12 levels in 110 patients with MS revealed that 65% had normal levels of Vitamin B12 (200–900 pg/ml), 30% had low levels of Vitamin B12 (<200 pg/ml), and 5% high levels of Vitamin B12 (higher than 900 pg/ml). Further analysis of patients with low levels of Vitamin B12 revealed that this cohort exhibited a significantly high number of patients with low levels of the thyroid hormones triiodothyronine (T3) and thyroxine (T4) (P < 0.005). Conclusion: This study suggests a relationship between Vitamin B12 levels and thyroid hormones. This opens the possibility that the use of therapies that increase triiodothyronine (T3) and thyroxine (T4) levels might be beneficial to patients with MS. PMID:27625581

  13. Spatial-temporal characteristics of lake level change in Tibet and Qinghai from two decades of altimeter observations

    NASA Astrophysics Data System (ADS)

    Cheng, Y. S.; Hwang, C.; Huang, C. Y.; Kao, R.; Han, J.

    2015-12-01

    Lake levels in the Tibet and Qinghai Plateaus provide valuable records for climate change studies. Most lakes here are hard to access, having only few lake level gauges that give in situ measurements of changes in lake level and area. Remote sensing sensors, such as satellite imagery and satellite altimetry, are able to measure lake level variations with a dense spatial coverage and with a high temporal resolution. In this study, we use the TOPEX/Poseidon series of satellite altimeters (TP, Jason-1 and -2, 1992-2014) to observe lake level variations at 23 lakes along their repeat ground tracks every 10 days. We also use the Envisat altimeter (2002-2008) to observe lake levels in three lakes of Qinghai at an interval of 35 days. We use subwaveform retracking to improve the ranging precisions of satellite altimeters. We employ an optimal processing technique to obtain quality measurements, including outlier detection, space-time reduction of measurements to a common reference point, and optimal filtering. Jason-1 fails to deliver height measurements over most of the lakes. The waveforms are classified to ensure observations with a sufficiently good quality. Over 1992-2014, the lake levels of most lakes in eastern Tibet rose, while the lake levels in western Tibet dropped. In Qinghai, the lake levels dropped before 2005 and then rose afterwards, suggesting a sharp climate change in 2005, or that the measure to protect the Qinghai ecosystem (e.g., reducing livestocks) started to take effect in 2005. In general, the overall pattern of lake change in Tibet and Qinghai is related to the variation of the Indian monsoons and locations of lakes. Most lake levels show clear annual and inter-annual oscillations. In some lakes, the amplitudes of annual variation in the TP era (1992-2002) were large and then turned smaller in the Jason-2 era (2008-2014). In some lakes, the annual amplitudes were reversed between the TP and Jason-2 eras. Also, some lakes show phase shifts in the

  14. Is serum vitamin D levels associated with disability in patients with newly diagnosed multiple sclerosis?

    PubMed Central

    Hatamian, Hamidreza; Bidabadi, Elham; Saadat, Seyed Mohammad Seyed; Saadat, Niloufar Seyed; Kazemnezhad, Ehsan; Ramezani, Hamed

    2013-01-01

    Background Although the precise etiology of multiple sclerosis (MS) is unknown, it seems that both genetic and environmental factors are important. Recent studies suggest that low serum vitamin D levels are important environmental factor in MS. The aim of this study was to compare the serum levels of vitamin D between MS patients and healthy subjects, and to determine its association with disability in MS patients. Methods In this cross-sectional study, a total of 52 patients with MS were randomly recruited and matched for age and sex with 52 healthy subjects. Demographic characteristics and serum vitamin D levels for both groups, as well as duration of disease Expanded Disability Status Scale (EDSS) for MS patients were evaluated. Statistical analysis was performed by independent samples t-test and multiple linear regression analysis. Results The mean serum vitamin D levels were 26.5 ± 16.3 ng/ml in MS patients vs. 37.1 ±19.7 in healthy subjects (P = 0.003). A linear regression analysis showed no significant association between vitamin D levels and EDSS score of patients with MS (P = 0.345), after adjusting for the covariates. Conclusion Our findings did not suggest a protective association for serum vitamin D levels against disability in MS patients. PMID:24250900

  15. Osteoprotegerin levels in ST-elevation myocardial infarction: Temporal profile and association with myocardial injury and left ventricular function

    PubMed Central

    Shetelig, Christian; Limalanathan, Shanmuganathan; Eritsland, Jan; Hoffmann, Pavel; Seljeflot, Ingebjørg; Gran, Jon Michael; Aukrust, Pål; Ueland, Thor; Andersen, Geir Øystein

    2017-01-01

    Background Elevated levels of osteoprotegerin (OPG) have been associated with adverse outcomes in ST-elevation myocardial infarction (STEMI). However, the role of OPG in myocardial injury and adverse remodeling in STEMI patients remains unclear. The aims of this observational cohort study were to evaluate: 1) the temporal profile of OPG during STEMI, 2) possible associations between OPG measured acutely and after 4 months, with infarct size, adverse left ventricular (LV) remodeling, microvascular obstruction (MVO) and myocardial salvage and 3) the effect of heparin administration on OPG levels. Methods Blood samples were drawn repeatedly from 272 STEMI patients treated with primary percutaneous coronary intervention (PCI). Cardiac magnetic resonance imaging (CMR) was performed in the acute phase and after 4 months. The effect of heparin administration on OPG levels was studied in 20 patients referred to elective coronary angiography. Results OPG levels measured acutely were significantly higher than Day 1 and during follow-up. OPG levels were correlated with age. No association was found between early OPG levels and CMR measurements at 4 months. Patients with >median OPG levels measured at Day 1 had larger final infarct size, lower LV ejection fraction (LVEF) at 4 months and higher frequency of MVO. There were no associations between OPG and change in end-diastolic volume or myocardial salvage. OPG remained associated with infarct size and LVEF after adjustment for relevant covariates, except peak troponin T and CRP. A 77% increase in OPG levels following heparin administration was found in patients undergoing elective coronary angiography. Conclusions OPG was found to be associated with myocardial injury, but not with LV remodeling or myocardial salvage. The use of OPG as a biomarker in STEMI patients seems to be limited by a strong association with age, confounding effect of heparin administration, and little additive value to established biomarkers. PMID

  16. Frequent globular neuronal cytoplasmic inclusions in the medial temporal region as a possible characteristic feature in multiple system atrophy with dementia.

    PubMed

    Homma, Taku; Mochizuki, Yoko; Komori, Takashi; Isozaki, Eiji

    2016-10-01

    Multiple system atrophy (MSA) is an adult-onset neurodegenerative disease, which is characterized clinically by parkinsonism, cerebellar ataxia and/or autonomic dysfunction, and pathologically by alpha-synuclein-related multisystem neurodegeneration, so-called alpha-synucleinopathy, which particularly involves the striatonigral and olivopontocerebellar systems, with glial cytoplasmic inclusions and neuronal cytoplasmic/nuclear inclusions (NCIs/NNIs). In the recent consensus criteria for the diagnosis of MSA, dementia is described as one of the features not supporting a diagnosis of MSA. However, MSA with dementia has been reported, although the location of the lesion responsible for the dementia remains unclear. In the present study, we aimed to investigate where this lesion may be found, by analyzing 12 autopsy-proven MSA cases, with a particular focus on the medial temporal region. Three of 12 cases with MSA had dementia (MSA-D). Compared with MSA cases without dementia, MSA-D cases had frequent globular NCIs (G-NCIs) in the medial temporal region, especially in their subiculum. In addition, MSA-D cases could be divided into two types; MSA-D with distinct fronto-temporal lobar degeneration (FTLD type) and without distinct fronto-temporal lobar degeneration (non-FTLD type). There was no association between dementia and Alzheimer pathologies, such as neurofibrillary tangles and senile plaques. We suggest that frequent G-NCIs in the medial temporal region, and particularly the subiculum, is one of the important pathological findings of MSA-D, even when a case with MSA-D reveals no significant cerebral atrophy.

  17. Multiple drivers of Holocene lake level changes at a lowland lake in northeastern Germany

    NASA Astrophysics Data System (ADS)

    Dietze, Elisabeth; Słowiński, Michał; Zawiska, Izabela; Veh, Georg; Brauer, Achim

    2016-04-01

    Many northeastern German lakes experienced significant water level drops in the recent past, which were attributed to global climate change, but due to the short observation period not fully understood. At lake Fürstenseer See, a groundwater-fed lake with complex basin morphology within the Müritz national park, an acoustic sub-bottom profile was analyzed together with a transect of four sediment cores to assess full Holocene water level amplitudes and the evolution of lake level changes during the Holocene. At core sites in 10 and 15 m water depth, past shifts in the sediment limit, i.e. the limit between preferential sand and mud deposition depending on absolute lake level, allowed to quantify an 8 m maximum Holocene amplitude of lake level changes (+4 m higher to -4 m lower stands), which clearly exceeded the observed fluctuations of 1.3 m between 1973 and 2013. At sites in 20 and 23 m water depth, changes in sediment facies reflected lake level changes qualitatively. During high lake stands massive organic muds were deposited in the deepest part of the lake basin, whereas during lower lake levels sub-basins became isolated causing an exceedance of the thresholds for carbonate accumulation. The highly-resolved continuous m-XRF-Calcium record of the longest core resembles these sediment facies shifts and allows to determine a relative Holocene lake level history. However, temporal interpretation of the causes and conditions that link carbonate preservation with local water level changes was rather complex and non-stationary. Apart from glaciological and climatic reasons also eco-hydrological feedbacks (i.e. vegetation composition affecting groundwater recharge) and anthropogenic triggers will be discussed in detail. This is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis (ICLEA) and the Terrestrial Environmental Observatories network (TERENO) financed by the Helmholtz Association.

  18. Temporal Levels of Urinary Neonicotinoid and Dialkylphosphate Concentrations in Japanese Women Between 1994 and 2011.

    PubMed

    Ueyama, Jun; Harada, Kouji H; Koizumi, Akio; Sugiura, Yuka; Kondo, Takaaki; Saito, Isao; Kamijima, Michihiro

    2015-12-15

    Over the last two decades, usage of neonicotinoid (NEO) insecticides has increased due to their high selectivity for insects versus mammals and their effectiveness for extermination of insects resistant to conventional pesticides such as pyrethroids and organophosphates (OPs). However, historical change of the NEO exposure level in humans is poorly understood. The aim of this study is to reveal changes in the levels of NEO and OP exposure in the human body over the last two decades using biomonitoring technique. We quantified urinary concentrations of 7 NEOs (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam) and 4 metabolites of OPs (dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate) in 95 adult females aged 45-75 in 1994, 2000, 2003, 2009, and 2011 (n = 17-20 different individuals in each year). The results show that the detection rates of urinary NEOs in Japanese women increased significantly between 1994 and 2011, suggesting that intakes of NEOs into the human body rose during that period. In contrast, exposure to OPs having O,O-dimethyl moieties decreased steadily according to a finding that geometric means of urinary dimethylphosphate concentrations kept diminishing considerably. These changes may reflect the amounts of NEOs and OPs used as insecticides in Japan.

  19. Formation of multiple levels of porous silicon for buried insulators and conductors in silicon device technologies

    DOEpatents

    Blewer, Robert S.; Gullinger, Terry R.; Kelly, Michael J.; Tsao, Sylvia S.

    1991-01-01

    A method of forming a multiple level porous silicon substrate for semiconductor integrated circuits including anodizing non-porous silicon layers of a multi-layer silicon substrate to form multiple levels of porous silicon. At least one porous silicon layer is then oxidized to form an insulating layer and at least one other layer of porous silicon beneath the insulating layer is metallized to form a buried conductive layer. Preferably the insulating layer and conductive layer are separated by an anodization barrier formed of non-porous silicon. By etching through the anodization barrier and subsequently forming a metallized conductive layer, a fully or partially insulated buried conductor may be fabricated under single crystal silicon.

  20. Structural invariance of multiple intelligences, based on the level of execution.

    PubMed

    Almeida, Leandro S; Prieto, María Dolores; Ferreira, Arístides; Ferrando, Mercedes; Ferrandiz, Carmen; Bermejo, Rosario; Hernández, Daniel

    2011-11-01

    The independence of multiple intelligences (MI) of Gardner's theory has been debated since its conception. This article examines whether the one- factor structure of the MI theory tested in previous studies is invariant for low and high ability students. Two hundred ninety-four children (aged 5 to 7) participated in this study. A set of Gardner's Multiple Intelligence assessment tasks based on the Spectrum Project was used. To analyze the invariance of a general dimension of intelligence, the different models of behaviours were studied in samples of participants with different performance on the Spectrum Project tasks with Multi-Group Confirmatory Factor Analysis (MGCFA). Results suggest an absence of structural invariance in Gardner's tasks. Exploratory analyses suggest a three-factor structure for individuals with higher performance levels and a two-factor structure for individuals with lower performance levels.

  1. Light, nutrients, and food-chain length constrain planktonic energy transfer efficiency across multiple trophic levels.

    PubMed

    Dickman, Elizabeth M; Newell, Jennifer M; González, María J; Vanni, Michael J

    2008-11-25

    The efficiency of energy transfer through food chains [food chain efficiency (FCE)] is an important ecosystem function. It has been hypothesized that FCE across multiple trophic levels is constrained by the efficiency at which herbivores use plant energy, which depends on plant nutritional quality. Furthermore, the number of trophic levels may also constrain FCE, because herbivores are less efficient in using plant production when they are constrained by carnivores. These hypotheses have not been tested experimentally in food chains with 3 or more trophic levels. In a field experiment manipulating light, nutrients, and food-chain length, we show that FCE is constrained by algal food quality and food-chain length. FCE across 3 trophic levels (phytoplankton to carnivorous fish) was highest under low light and high nutrients, where algal quality was best as indicated by taxonomic composition and nutrient stoichiometry. In 3-level systems, FCE was constrained by the efficiency at which both herbivores and carnivores converted food into production; a strong nutrient effect on carnivore efficiency suggests a carryover effect of algal quality across 3 trophic levels. Energy transfer efficiency from algae to herbivores was also higher in 2-level systems (without carnivores) than in 3-level systems. Our results support the hypothesis that FCE is strongly constrained by light, nutrients, and food-chain length and suggest that carryover effects across multiple trophic levels are important. Because many environmental perturbations affect light, nutrients, and food-chain length, and many ecological services are mediated by FCE, it will be important to apply these findings to various ecosystem types.

  2. Temporal Assessment of the Impact of Exposure to Cow Feces in Two Watersheds by Multiple Host-Specific PCR Assays

    EPA Science Inventory

    Exposure to feces in two watersheds with different management histories was assessed by tracking cattle feces bacterial populations using multiple host-specific PCR assays. In addition, environmental factors affecting the occurrence of these markers were identified. Each assay wa...

  3. A collection of rare anomalies: multiple digital glomuvenous malformations, epidermal naevus, temporal alopecia, heterochromia and abdominal lipoblastoma.

    PubMed

    Hill, S; Rademaker, M

    2009-12-01

    Glomuvenous malformations are a subtype of venous malformations, which present in infancy or childhood. We describe a teenage girl who presented with multiple digital glomuvenous malformations from birth. In addition, she had an epidermal naevus on the upper lip, an area of congenital alopecia of the scalp, heterochromia irides and an abdominal lipoblastoma. We are unaware of any reports of the association of multiple glomuvenous malformations with the other uncommon developmental anomalies seen in our patient, and a common link eludes us.

  4. Temporal Partitioning on Multicore Platform

    NASA Astrophysics Data System (ADS)

    Mahmud Pathan, Ristat; Hashi, Feysal; Stenstrom, Per; Green, Lars-Goran; Hult, Torbjorn; Sandin, Patrik

    2014-08-01

    This paper addresses the problem of ensuring temporal partitioning according to the ARINC-653 standard for integrating multiple applications on the same multicore platform. To employ temporal partitioning, we propose the design and analysis of a hierarchical scheduling framework (HSF) for multicore platform. In HSF, each application has a server task, which is mapped to one of the physical cores of the multicore platform. The HSF framework is based on scheduling at two-levels: (i) a system-level scheduler for each core schedules the server tasks that are mapped to that core, and (ii) a task- level scheduler for each application schedules the tasks of the application. This paper presents the design and analysis of this two-level HSF that can be used to ensure temporal partitioning and meeting all the deadlines of each application tasks. The effectiveness of our technique is demonstrated using real-world space applications provided by RUAG Space Sweden AB.

  5. Physically feasible three-level transitionless quantum driving with multiple Schrödinger dynamics

    NASA Astrophysics Data System (ADS)

    Song, Xue-Ke; Ai, Qing; Qiu, Jing; Deng, Fu-Guo

    2016-05-01

    Three-level quantum systems, which possess some unique characteristics beyond two-level ones, such as electromagnetically induced transparency, coherent trapping, and Raman scatting, play important roles in solid-state quantum information processing. Here, we introduce an approach to implement the physically feasible three-level transitionless quantum driving with multiple Schrödinger dynamics (MSDs). It can be used to control accurately population transfer and entanglement generation for three-level quantum systems in a nonadiabatic way. Moreover, we propose an experimentally realizable hybrid architecture, based on two nitrogen-vacancy-center ensembles coupled to a transmission line resonator, to realize our transitionless scheme which requires fewer physical resources and simple procedures, and it is more robust against environmental noises and control parameter variations than conventional adiabatic passage techniques. All these features inspire the further application of MSDs on robust quantum information processing in experiment.

  6. The spatial and temporal variability of the seasonal mean sea level cycle in the South China Sea

    NASA Astrophysics Data System (ADS)

    Muhaimin Amiruddin, Abd; Haigh, Ivan; Tsimplis, Mikis; Calafat, Francisco; Dangendorf, Soenke

    2015-04-01

    The seasonal cycle is the most energetic component of mean sea level variability and changes in either its amplitude or phase can seriously impact the risk of coastal flooding. Here, tide gauge records and satellite altimetry observations, along with steric and meteorological data are used to investigate the spatial and temporal variability of the seasonal cycle in the South China Sea (SCS) and its forcing mechanisms. The coastal annual amplitude varies significantly from region to region with values ranging from 2 cm to 24 cm, and generally peaks between July and January. The coastal semi-annual amplitude has maximum values of 7 cm, and it peaks between March and June. Along the coast, the seasonal cycle accounts on average for 60% with maximum values of up to 92% of the mean monthly sea level variability. Atmospheric pressure fluctuations explain a significant portion of the seasonal cycle with dominant annual signals in the northern SCS, the Gulf of Thailand and the north-western Philippines Sea. The wind forcing is dominant on the shelf areas of the SCS and the Gulf of Thailand where a simple barotropic model forced by local wind shows amplitudes of up to 27 cm. In the deep basin of the SCS, the Philippines Sea and the shallow Malacca Strait, the steric component is the major contributor with maximum annual amplitudes of up to 15 cm. Significant variability in the annual and semi-annual cycle is found on a year-to-year basis. The annual and semi-annual amplitudes vary by up to 63% and 45% of the maximum values, 15 cm and 11 cm, respectively. On average, stepwise regression analysis of contribution of different forcing factors accounts for 69% of the temporal variability of the annual cycle. The zonal wind and the cross-shore wind were found to exert considerable influence in the Malacca Strait and the northern SCS respectively.

  7. Introduction of temporal sub-stepping in the Multi-Level Multi-Domain semi-implicit Particle-In-Cell code Parsek2D-MLMD

    NASA Astrophysics Data System (ADS)

    Innocenti, M. E.; Beck, A.; Ponweiser, T.; Markidis, S.; Lapenta, G.

    2015-04-01

    In this paper, the introduction of temporal sub-stepping in Multi-Level Multi-Domain (MLMD) simulations of plasmas is discussed. The MLMD method addresses the multi-scale nature of space plasmas by simulating a problem at different levels of resolution. A large-domain "coarse grid" is simulated with low resolution to capture large-scale, slow processes. Smaller scale, local processes are obtained through a "refined grid" which uses higher resolution. Very high jumps in the resolution used at the different levels can be achieved thanks to the Implicit Moment Method and appropriate grid interlocking operations. Up to now, the same time step was used at all the levels. Now, with temporal sub-stepping, the different levels can also benefit from the use of different temporal resolutions. This saves further resources with respect to "traditional" simulations done using the same spatial and temporal stepping on the entire domain. It also prevents the levels from working at the limits of the stability condition of the Implicit Moment Method. The temporal sub-stepping is tested with simulations of magnetic reconnection in space. It is shown that, thanks to the reduced costs of MLMD simulations with respect to single-level simulations, it becomes possible to verify with realistic mass ratios scaling laws previously verified only for reduced mass ratios. Performance considerations are also provided.

  8. The temporal profile of postactivation potentiation is related to strength level.

    PubMed

    Seitz, Laurent B; de Villarreal, Eduardo S; Haff, G Gregory

    2014-03-01

    The purpose of this investigation was to determine whether stronger individuals are able to express postactivation potentiation (PAP) earlier than weaker individuals during a vertical squat jump test. Eighteen junior elite rugby league players were divided into strong (relative 1 repetition maximum [1RM] back squat ≥ 2 × body mass) and weak (relative 1RM back squat <2.0 × body mass) groups. Each subject performed squat jumps before, 15 seconds, 3, 6, 9, and 12 minutes after a conditioning activity (CA) that contained 1 set of 3 back squats performed at 90% of 1RM. A force plate, which sampled at 1000 Hz, was used to determine the power output and height for each squat jump. Stronger individuals expressed PAP between 3 and 12 minutes post-CA, whereas their weaker counterparts displayed potentiation between 6 and 12 minutes post-CA. Moreover, the stronger group exhibited a significantly (p ≤ 0.05) higher PAP response than the weaker group at all post-CA squat jump tests. The stronger group displayed the greatest potentiation at 6 minutes post-CA, whereas the weaker group displayed the greatest potentiation response at 9 minutes following the CA. Based on these results, stronger individuals appear to be able to express PAP earlier after a CA than weaker individuals. Additionally, stronger individuals express significantly greater postactivation responses than weaker individuals. From a practical standpoint, strength and conditioning coaches should consider the athletes' strength levels when constructing postactivation complexes (CA + performance activity) as strength will dictate the time frame required between the conditioning and the performance activity.

  9. Dual-color multiple-particle tracking at 50-nm localization and over 100-µm range in 3D with temporal focusing two-photon microscopy

    PubMed Central

    Ding, Yu; Li, Chunqiang

    2016-01-01

    Nanoscale particle tracking in three dimensions is crucial to directly observe dynamics of molecules and nanoparticles in living cells. Here we present a three-dimensional particle tracking method based on temporally focused two-photon excitation. Multiple particles are imaged at 30 frames/s in volume up to 180 × 180 × 100 µm3. The spatial localization precision can reach 50 nm. We demonstrate its capability of tracking fast swimming microbes at speed of ~200 µm/s. Two-photon dual-color tracking is achieved by simultaneously exciting two kinds of fluorescent beads at 800 nm to demonstrate its potential in molecular interaction studies. Our method provides a simple wide-field fluorescence imaging approach for deep multiple-particle tracking. PMID:27867724

  10. Understanding epigenetic regulation: Tracking protein levels across multiple generations of cells

    NASA Astrophysics Data System (ADS)

    Rowat, A. C.; Weitz, D. A.

    2009-11-01

    Cells and organisms are remarkably robust: they alter the variety and levels of expressed genes and proteins in response to environmental stimuli, including temperature, chemicals, and the stiffness of their surroundings. Ultimately changes in gene and protein expression can result in a distinct phenotypic state, which in some cases is maintained over multiple generations; the ability to pass on a particular phenotypic state to progeny cells is critical for differentiation. Moreover, epigenetic regulation of phenotype is also thought to provide an evolutionary advantage for a population of cells adapting to a fluctuating environment on faster timescales than the occurrence of genetic mutations. However, simple methods to study patterns of gene and protein expression on multi-generational timescales are sparse. Here we describe a technique to study lineages of single cells over multiple generations using a microfluidic device; this reveals patterns of expression where protein levels are correlated across multiple generations. Such quantitative information of protein expression in the context of pedigree remains hidden when studying the population as an ensemble.

  11. Water mass change in the Amazon basin estimated by multi-temporal SAR data, GRACE gravimetry and water level observations

    NASA Astrophysics Data System (ADS)

    Spiridonova, S.; Seitz, F.; Hedman, K.; Meyer, F.

    2012-04-01

    -tion. Multiplying the differences in heights between high and low water periods by the area of the DEM reso-lution cell and summing them up over the river area provided an estimate of the total volume change. In the end, the presentation will give an assessment of the spatio-temporal consistency of the different ob-servation systems by comparing the spatial patterns of water variability in the data sets with respect to their temporal development and existing phase lags. Based on the level of consistency we will provide an outlook on the applicability of measurements of water levels and surface water extent for an independent assess-ment of water mass variations.

  12. Estimation of the discharges of the multiple water level stations by multi-objective optimization

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kazuhiro; Miyamoto, Mamoru; Yamakage, Yuzuru; Tsuda, Morimasa; Yanami, Hitoshi; Anai, Hirokazu; Iwami, Yoichi

    2016-04-01

    This presentation shows two aspects of the parameter identification to estimate the discharges of the multiple water level stations by multi-objective optimization. One is how to adjust the parameters to estimate the discharges accurately. The other is which optimization algorithms are suitable for the parameter identification. Regarding the previous studies, there is a study that minimizes the weighted error of the discharges of the multiple water level stations by single-objective optimization. On the other hand, there are some studies that minimize the multiple error assessment functions of the discharge of a single water level station by multi-objective optimization. This presentation features to simultaneously minimize the errors of the discharges of the multiple water level stations by multi-objective optimization. Abe River basin in Japan is targeted. The basin area is 567.0km2. There are thirteen rainfall stations and three water level stations. Nine flood events are investigated. They occurred from 2005 to 2012 and the maximum discharges exceed 1,000m3/s. The discharges are calculated with PWRI distributed hydrological model. The basin is partitioned into the meshes of 500m x 500m. Two-layer tanks are placed on each mesh. Fourteen parameters are adjusted to estimate the discharges accurately. Twelve of them are the hydrological parameters and two of them are the parameters of the initial water levels of the tanks. Three objective functions are the mean squared errors between the observed and calculated discharges at the water level stations. Latin Hypercube sampling is one of the uniformly sampling algorithms. The discharges are calculated with respect to the parameter values sampled by a simplified version of Latin Hypercube sampling. The observed discharge is surrounded by the calculated discharges. It suggests that it might be possible to estimate the discharge accurately by adjusting the parameters. In a sense, it is true that the discharge of a water

  13. Computing multiple aggregation levels and contextual features for road facilities recognition using mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Dong, Zhen; Liu, Yuan; Liang, Fuxun; Wang, Yongjun

    2017-04-01

    In recent years, updating the inventory of road infrastructures based on field work is labor intensive, time consuming, and costly. Fortunately, vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. However, robust recognition of road facilities from huge volumes of 3D point clouds is still a challenging issue because of complicated and incomplete structures, occlusions and varied point densities. Most existing methods utilize point or object based features to recognize object candidates, and can only extract limited types of objects with a relatively low recognition rate, especially for incomplete and small objects. To overcome these drawbacks, this paper proposes a semantic labeling framework by combing multiple aggregation levels (point-segment-object) of features and contextual features to recognize road facilities, such as road surfaces, road boundaries, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, and cars, for highway infrastructure inventory. The proposed method first identifies ground and non-ground points, and extracts road surfaces facilities from ground points. Non-ground points are segmented into individual candidate objects based on the proposed multi-rule region growing method. Then, the multiple aggregation levels of features and the contextual features (relative positions, relative directions, and spatial patterns) associated with each candidate object are calculated and fed into a SVM classifier to label the corresponding candidate object. The recognition performance of combining multiple aggregation levels and contextual features was compared with single level (point, segment, or object) based features using large-scale highway scene point clouds. Comparative studies demonstrated that the proposed semantic labeling framework significantly improves road facilities recognition

  14. The impact of multiple low-level BCR-ABL1 mutations on response to ponatinib

    PubMed Central

    Yeung, David T. O.; Yeoman, Alexandra L.; Altamura, Haley K.; Jamison, Bronte A.; Field, Chani R.; Hodgson, J. Graeme; Lustgarten, Stephanie; Rivera, Victor M.; Hughes, Timothy P.; Branford, Susan

    2016-01-01

    The third-generation tyrosine kinase inhibitor (TKI) ponatinib shows activity against all common BCR-ABL1 single mutants, including the highly resistant BCR-ABL1-T315I mutant, improving outcome for patients with refractory chronic myeloid leukemia (CML). However, responses are variable, and causal baseline factors have not been well-studied. The type and number of low-level BCR-ABL1 mutations present after imatinib resistance has prognostic significance for subsequent treatment with nilotinib or dasatinib as second-line therapy. We therefore investigated the impact of low-level mutations detected by sensitive mass-spectrometry before ponatinib initiation (baseline) on treatment response in 363 TKI-resistant patients enrolled in the PONATINIB for Chronic Myeloid Leukemia Evaluation and Ph+ Acute Lymphoblastic Leukemia trial, including 231 patients in chronic phase (CP-CML). Low-level mutations were detected in 53 patients (15%, including low-level T315I in 14 patients); most, however, did not undergo clonal expansion during ponatinib treatment and, moreover, no specific individual mutations were associated with inferior outcome. We demonstrate however, that the number of mutations detectable by mass spectrometry after TKI resistance is associated with response to ponatinib treatment and could be used to refine the therapeutic approach. Although CP-CML patients with T315I (63/231, 27%) had superior responses overall, those with multiple mutations detectable by mass spectrometry (20, 32%) had substantially inferior responses compared with those with T315I as the sole mutation detected (43, 68%). In contrast, for CP-CML patients without T315I, the inferior responses previously observed with nilotinib/dasatinib therapy for imatinib-resistant patients with multiple mutations were not seen with ponatinib treatment, suggesting that ponatinib may prove to be particularly advantageous for patients with multiple mutations detectable by mass spectrometry after TKI resistance

  15. A temporal and spatial analysis of ground-water levels for effective monitoring in Huron County, Michigan

    USGS Publications Warehouse

    Holtschlag, David J.; Sweat, M.J.

    1999-01-01

    Quarterly water-level measurements were analyzed to assess the effectiveness of a monitoring network of 26 wells in Huron County, Michigan. Trends were identified as constant levels and autoregressive components were computed at all wells on the basis of data collected from 1993 to 1997, using structural time series analysis. Fixed seasonal components were identified at 22 wells and outliers were identified at 23 wells. The 95- percent confidence intervals were forecast for water-levels during the first and second quarters of 1998. Intervals in the first quarter were consistent with 92.3 percent of the measured values. In the second quarter, measured values were within the forecast intervals only 65.4 percent of the time. Unusually low precipitation during the second quarter is thought to have contributed to the reduced reliability of the second-quarter forecasts. Spatial interrelations among wells were investigated on the basis of the autoregressive components, which were filtered to create a set of innovation sequences that were temporally uncorrelated. The empirical covariance among the innovation sequences indicated both positive and negative spatial interrelations. The negative covariance components are considered to be physically implausible and to have resulted from random sampling error. Graphical modeling, a form of multivariate analysis, was used to model the covariance structure. Results indicate that only 29 of the 325 possible partial correlations among the water-level innovations were statistically significant. The model covariance matrix, corresponding to the model partial correlation structure, contained only positive elements. This model covariance was sequentially partitioned to compute a set of partial covariance matrices that were used to rank the effectiveness of the 26 monitoring wells from greatest to least. Results, for example, indicate that about 50 percent of the uncertainty of the water-level innovations currently monitored by the 26

  16. Biologically Motivated Novel Localization Paradigm by High-Level Multiple Object Recognition in Panoramic Images

    PubMed Central

    Kim, Sungho; Shim, Min-Sheob

    2015-01-01

    This paper presents the novel paradigm of a global localization method motivated by human visual systems (HVSs). HVSs actively use the information of the object recognition results for self-position localization and for viewing direction. The proposed localization paradigm consisted of three parts: panoramic image acquisition, multiple object recognition, and grid-based localization. Multiple object recognition information from panoramic images is utilized in the localization part. High-level object information was useful not only for global localization, but also for robot-object interactions. The metric global localization (position, viewing direction) was conducted based on the bearing information of recognized objects from just one panoramic image. The feasibility of the novel localization paradigm was validated experimentally. PMID:26457323

  17. Measuring the engagement level of children for multiple intelligence test using Kinect

    NASA Astrophysics Data System (ADS)

    Lee, Dongjin; Yun, Woo han; Park, Chan kyu; Yoon, H.; Kim, Jaehong; Park, C. H.

    2015-02-01

    In this paper, we present an affect recognition system for measuring the engagement level of children using the Kinect while performing a multiple intelligence test on a computer. First of all, we recorded 12 children while solving the test and manually created a ground truth data for the engagement levels of each child. For a feature extraction, Kinect for Windows SDK provides support for a user segmentation and skeleton tracking so that we can get 3D joint positions of an upper-body skeleton of a child. After analyzing movement of children, the engagement level of children's responses is classified into two classes: High or Low. We present the classification results using the proposed features and identify the significant features in measuring the engagement.

  18. Genetic variants are major determinants of CSF antibody levels in multiple sclerosis.

    PubMed

    Goris, An; Pauwels, Ine; Gustavsen, Marte W; van Son, Brechtje; Hilven, Kelly; Bos, Steffan D; Celius, Elisabeth Gulowsen; Berg-Hansen, Pål; Aarseth, Jan; Myhr, Kjell-Morten; D'Alfonso, Sandra; Barizzone, Nadia; Leone, Maurizio A; Martinelli Boneschi, Filippo; Sorosina, Melissa; Liberatore, Giuseppe; Kockum, Ingrid; Olsson, Tomas; Hillert, Jan; Alfredsson, Lars; Bedri, Sahl Khalid; Hemmer, Bernhard; Buck, Dorothea; Berthele, Achim; Knier, Benjamin; Biberacher, Viola; van Pesch, Vincent; Sindic, Christian; Bang Oturai, Annette; Søndergaard, Helle Bach; Sellebjerg, Finn; Jensen, Poul Erik H; Comabella, Manuel; Montalban, Xavier; Pérez-Boza, Jennifer; Malhotra, Sunny; Lechner-Scott, Jeannette; Broadley, Simon; Slee, Mark; Taylor, Bruce; Kermode, Allan G; Gourraud, Pierre-Antoine; Sawcer, Stephen J; Andreassen, Bettina Kullle; Dubois, Bénédicte; Harbo, Hanne F

    2015-03-01

    Immunological hallmarks of multiple sclerosis include the production of antibodies in the central nervous system, expressed as presence of oligoclonal bands and/or an increased immunoglobulin G index-the level of immunoglobulin G in the cerebrospinal fluid compared to serum. However, the underlying differences between oligoclonal band-positive and -negative patients with multiple sclerosis and reasons for variability in immunoglobulin G index are not known. To identify genetic factors influencing the variation in the antibody levels in the cerebrospinal fluid in multiple sclerosis, we have performed a genome-wide association screen in patients collected from nine countries for two traits, presence or absence of oligoclonal bands (n = 3026) and immunoglobulin G index levels (n = 938), followed by a replication in 3891 additional patients. We replicate previously suggested association signals for oligoclonal band status in the major histocompatibility complex region for the rs9271640*A-rs6457617*G haplotype, correlated with HLA-DRB1*1501, and rs34083746*G, correlated with HLA-DQA1*0301 (P comparing two haplotypes = 8.88 × 10(-16)). Furthermore, we identify a novel association signal of rs9807334, near the ELAC1/SMAD4 genes, for oligoclonal band status (P = 8.45 × 10(-7)). The previously reported association of the immunoglobulin heavy chain locus with immunoglobulin G index reaches strong evidence for association in this data set (P = 3.79 × 10(-37)). We identify two novel associations in the major histocompatibility complex region with immunoglobulin G index: the rs9271640*A-rs6457617*G haplotype (P = 1.59 × 10(-22)), shared with oligoclonal band status, and an additional independent effect of rs6457617*G (P = 3.68 × 10(-6)). Variants identified in this study account for up to 2-fold differences in the odds of being oligoclonal band positive and 7.75% of the variation in immunoglobulin G index. Both traits are associated with clinical features of disease such

  19. Genetic variants are major determinants of CSF antibody levels in multiple sclerosis

    PubMed Central

    Pauwels, Ine; Gustavsen, Marte W.; van Son, Brechtje; Hilven, Kelly; Bos, Steffan D.; Celius, Elisabeth Gulowsen; Berg-Hansen, Pål; Aarseth, Jan; Myhr, Kjell-Morten; D’Alfonso, Sandra; Barizzone, Nadia; Leone, Maurizio A.; Martinelli Boneschi, Filippo; Sorosina, Melissa; Liberatore, Giuseppe; Kockum, Ingrid; Olsson, Tomas; Hillert, Jan; Alfredsson, Lars; Bedri, Sahl Khalid; Hemmer, Bernhard; Buck, Dorothea; Berthele, Achim; Knier, Benjamin; Biberacher, Viola; van Pesch, Vincent; Sindic, Christian; Bang Oturai, Annette; Søndergaard, Helle Bach; Sellebjerg, Finn; Jensen, Poul Erik H.; Comabella, Manuel; Montalban, Xavier; Pérez-Boza, Jennifer; Malhotra, Sunny; Lechner-Scott, Jeannette; Broadley, Simon; Slee, Mark; Taylor, Bruce; Kermode, Allan G.; Gourraud, Pierre-Antoine; Sawcer, Stephen J.; Andreassen, Bettina Kullle; Dubois, Bénédicte; Harbo, Hanne F.

    2015-01-01

    Immunological hallmarks of multiple sclerosis include the production of antibodies in the central nervous system, expressed as presence of oligoclonal bands and/or an increased immunoglobulin G index—the level of immunoglobulin G in the cerebrospinal fluid compared to serum. However, the underlying differences between oligoclonal band-positive and -negative patients with multiple sclerosis and reasons for variability in immunoglobulin G index are not known. To identify genetic factors influencing the variation in the antibody levels in the cerebrospinal fluid in multiple sclerosis, we have performed a genome-wide association screen in patients collected from nine countries for two traits, presence or absence of oligoclonal bands (n = 3026) and immunoglobulin G index levels (n = 938), followed by a replication in 3891 additional patients. We replicate previously suggested association signals for oligoclonal band status in the major histocompatibility complex region for the rs9271640*A-rs6457617*G haplotype, correlated with HLA-DRB1*1501, and rs34083746*G, correlated with HLA-DQA1*0301 (P comparing two haplotypes = 8.88 × 10−16). Furthermore, we identify a novel association signal of rs9807334, near the ELAC1/SMAD4 genes, for oligoclonal band status (P = 8.45 × 10−7). The previously reported association of the immunoglobulin heavy chain locus with immunoglobulin G index reaches strong evidence for association in this data set (P = 3.79 × 10−37). We identify two novel associations in the major histocompatibility complex region with immunoglobulin G index: the rs9271640*A-rs6457617*G haplotype (P = 1.59 × 10−22), shared with oligoclonal band status, and an additional independent effect of rs6457617*G (P = 3.68 × 10−6). Variants identified in this study account for up to 2-fold differences in the odds of being oligoclonal band positive and 7.75% of the variation in immunoglobulin G index. Both traits are associated with clinical features of disease such

  20. Temporal variability in urinary levels of drinking water disinfection byproducts dichloroacetic acid and trichloroacetic acid among men

    SciTech Connect

    Wang, Yi-Xin; Zeng, Qiang; Wang, Le; Huang, Yue-Hui; Lu, Zhi-Wei; Wang, Peng; He, Meng-Jie; Huang, Xin; Lu, Wen-Qing

    2014-11-15

    Urinary haloacetic acids (HAAs), such as dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), have been suggested as potential biomarkers of exposure to drinking water disinfection byproducts (DBPs). However, variable exposure to and the short elimination half-lives of these biomarkers can result in considerable variability in urinary measurements, leading to exposure misclassification. Here we examined the variability of DCAA and TCAA levels in the urine among eleven men who provided urine samples on 8 days over 3 months. The urinary concentrations of DCAA and TCAA were measured by gas chromatography coupled with electron capture detection. We calculated the intraclass correlation coefficients (ICCs) to characterize the within-person and between-person variances and computed the sensitivity and specificity to assess how well single or multiple urine collections accurately determined personal 3-month average DCAA and TCAA levels. The within-person variance was much higher than the between-person variance for all three sample types (spot, first morning, and 24-h urine samples) for DCAA (ICC=0.08–0.37) and TCAA (ICC=0.09–0.23), regardless of the sampling interval. A single-spot urinary sample predicted high (top 33%) 3-month average DCAA and TCAA levels with high specificity (0.79 and 0.78, respectively) but relatively low sensitivity (0.47 and 0.50, respectively). Collecting two or three urine samples from each participant improved the classification. The poor reproducibility of the measured urinary DCAA and TCAA concentrations indicate that a single measurement may not accurately reflect individual long-term exposure. Collection of multiple urine samples from one person is an option for reducing exposure classification errors in studies exploring the effects of DBP exposure on reproductive health. - Highlights: • We evaluated the variability of DCAA and TCAA levels in the urine among men. • Urinary DCAA and TCAA levels varied greatly over a 3-month

  1. Multiple Levels of Family Factors and Oppositional Defiant Disorder Symptoms Among Chinese Children.

    PubMed

    Lin, Xiuyun; Li, Longfeng; Heath, Melissa A; Chi, Peilian; Xu, Shousen; Fang, Xiaoyi

    2016-11-30

    Family factors are closely associated with child developmental outcomes. This study examined the relationship of oppositional defiant disorder (ODD) symptoms and factors at whole family, dyadic, and individual levels in Chinese children. Participants, who were recruited from 14 primary schools in north, east, and south-west China, included 80 father-child dyads and 169 mother-child dyads. Children in the participating dyads were previously diagnosed with ODD. Results revealed that family cohesion/adaptability was indirectly associated with ODD symptoms via parent-child relationship and child emotion regulation. Parent-child relationship affected ODD symptoms directly and indirectly through child emotion regulation. In addition, the effects of family cohesion/adaptability on parent emotion regulation and child emotion regulation were mediated by the parent-child relationship. The tested model provides a comprehensive framework of how family factors at multiple levels are related to child ODD symptoms and highlights the importance of understanding child emotional and behavioral problems within the family context, more specifically within the multiple levels of family relationships.

  2. Low-Level Exposure to Multiple Chemicals: Reason for Human Health Concerns?

    PubMed Central

    Kortenkamp, Andreas; Faust, Michael; Scholze, Martin; Backhaus, Thomas

    2007-01-01

    Background A key question in the risk assessment of exposures to multiple chemicals is whether mixture effects may occur when chemicals are combined at low doses which individually do not induce observable effects. However, a systematic evaluation of experimental studies addressing this issue is missing. Objectives With this contribution, we wish to bridge this gap by providing a systematic assessment of published studies against well-defined quality criteria. Results On reviewing the low-dose mixture literature, we found good evidence demonstrating significant mixture effects with combinations of chemicals well below their individual no observable adverse effect levels (NOAELs), both with mixtures composed of similarly and dissimilarly acting agents. Conclusions The widely held view that mixtures of dissimilarly acting chemicals are “safe” at levels below NOAELs is not supported by empirical evidence. We show that this view is also based on the erroneous assumption that NOAELs can be equated with zero-effect levels. Thus, on the basis of published evidence, it is difficult to rule out the possibility of mixture effects from low-dose multiple exposures. PMID:18174958

  3. DeltaA/DeltaD regulate multiple and temporally distinct phases of notch signaling during dopaminergic neurogenesis in zebrafish.

    PubMed

    Mahler, Julia; Filippi, Alida; Driever, Wolfgang

    2010-12-08

    Dopaminergic neurons develop at distinct anatomical sites to form some of the major neuromodulatory systems in the vertebrate brain. Despite their relevance in neurodegenerative diseases and the interests in reconstitutive therapies from stem cells, mechanisms of the neurogenic switch from precursor populations to dopaminergic neurons are not well understood. Here, we investigated neurogenesis of different dopaminergic and noradrenergic neuron populations in the zebrafish embryo. Birth-dating analysis by EdU (5-ethynyl-2'-deoxyuridine) incorporation revealed temporal dynamics of catecholaminergic neurogenesis. Analysis of Notch signaling mutants and stage-specific pharmacological inhibition of Notch processing revealed that dopaminergic neurons form by temporally distinct mechanisms: dopaminergic neurons of the posterior tuberculum derive directly from neural plate cells during primary neurogenesis, whereas other dopaminergic groups form in continuous or wavelike neurogenesis phases from proliferating precursor pools. Systematic analysis of Notch ligands revealed that the two zebrafish co-orthologs of mammalian Delta1, DeltaA and DeltaD, control the neurogenic switch of all early developing dopaminergic neurons in a partially redundant manner. DeltaA/D may also be involved in maintenance of dopaminergic precursor pools, as olig2 expression in ventral diencephalic dopaminergic precursors is affected in dla/dld mutants. DeltaA/D act upstream of sim1a and otpa during dopaminergic specification. However, despite the fact that both dopaminergic and corticotropin-releasing hormone neurons derive from sim1a- and otpa-expressing precursors, DeltaA/D does not act as a lineage switch between these two neuronal types. Rather, DeltaA/D limits the size of the sim1a- and otpa-expressing precursor pool from which dopaminergic neurons differentiate.

  4. Community Health Workers promoting physical activity: Targeting multiple levels of the Social Ecological Model

    PubMed Central

    Haughton, Jessica; Ayala, Guadalupe X.; Burke, Kari Herzog; Elder, John P.; Montañez, Jacqueline; Arredondo, Elva M.

    2015-01-01

    The effectiveness of Community Health Workers (CHWs) as health educators and health promoters among Latino populations is widely recognized. The Affordable Care Act created important opportunities to increase the role of CHWs in preventive health. This article describes the implementation of CHW-led, culturally specific, faith-based program to increase physical activity (PA) among churchgoing Latinas. The current study augments previous research by describing the recruitment, selection, training, and evaluation of CHWs for a PA intervention targeting multiple levels of the Social Ecological Model. PMID:26280587

  5. Performance of mean-level detector in presence of multiple-tone interference plus noise

    NASA Astrophysics Data System (ADS)

    Al-Hussaini, E. K.

    1988-05-01

    Performance of the adaptive mean-level constant false alarm rate detector is derived in the presence of multiple-tone interference plus Gaussian noise. Such signals may result from jamming, interference, or multipath propagation. A square-law envelope detector is employed and a single sweep or hit is processed. The target signal envelope fluctuates according to a Rayleigh probability density function. The results show that the probability of a false alarm decreases monotonically with increasing interfering tonal SNR per pulse for one tone. The probability is unaffected when there is an infinite number of tones.

  6. Extremely high HDL levels in a patient with multiple symmetric lipomatosis.

    PubMed

    Deiana, L; Pes, G M; Carru, C; Campus, G V; Tidore, M G; Cherchi, G M

    1993-12-31

    An extreme form of hyperalphalipoproteinemia was studied in a patient affected by multiple symmetric lipomatosis (MSL); four relatives and three MSL controls were also evaluated. Plasma lipids and apolipoproteins were measured and overall lipoprotein profile was assessed by density gradient ultracentrifugation. The patient showed a plasma HDL-cholesterol of 138 mg/dl and an apo A-I of 218 mg/dl; moreover significantly high HDL levels were found in two unaffected relatives. The hypobetalipoproteinemia trait was also found both in the patient and in one of his daughters. We suggest that some pre-existing conditions may enhance lipoprotein metabolism alterations in this lipid storage disease.

  7. High levels of mercury contamination in multiple media of the Carson River drainage basin of Nevada: implications for risk assessment.

    PubMed Central

    Gustin, M S; Taylor, G E; Leonard, T L

    1994-01-01

    Approximately 5.5 x 109 g (4.0 x 105) of mercury was discharged into the Carson River Drainage Basin of west-central Nevada during processing of the gold- and silver-rich Comstock ore in the late 1800s. For the past 13 decades, mercury has been redistributed throughout 500 km2 of the basin, and concentrations are some of the highest reported values in North America. This article documents the concentrations of mercury in the air, water, and substrate at both contaminated and noncontaminated sites within the basin and discusses the implications for risk assessment. At contaminated areas, the range of mercury concentrations are as follows: mill tailings, 3-1610 micrograms/g; unfiltered reservoir water, 53-591 ng/l; atmospheric vapor, 2-294 ng/m3. These values are three to five orders of magnitude greater than natural background. In all media at contaminated sites, concentrations are spatially variable, and air and water mercury concentrations vary temporally. The study are in situated in a natural mercuriferous belt, and regional background mercury concentrations in all environmental media are higher than values typically cited for natural background. As a mercury-contaminated site in North America, the Carson River Drainage Basin is unusual for a number of reasons, including its location in a natural mercuriferous belt, high and sustained levels of anthropogenic mercury inputs, long exposure time, aridity of the climate, and the riparian setting in an arid landscape, where biological activity is concentrated in the same areas that contain high levels of mercury in multiple media. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 4. Figure 4. PMID:9657709

  8. Spatio-Temporal Factors Associated with Meningococcal Meningitis Annual Incidence at the Health Centre Level in Niger, 2004–2010

    PubMed Central

    Paireau, Juliette; Collard, Jean-Marc; Idi, Issa; Moulia-Pelat, Jean-Paul; Mueller, Judith E.; Fontanet, Arnaud

    2014-01-01

    Background Epidemics of meningococcal meningitis (MM) recurrently strike the African Meningitis Belt. This study aimed at investigating factors, still poorly understood, that influence annual incidence of MM serogroup A, the main etiologic agent over 2004–2010, at a fine spatial scale in Niger. Methodology/Principal Findings To take into account data dependencies over space and time and control for unobserved confounding factors, we developed an explanatory Bayesian hierarchical model over 2004–2010 at the health centre catchment area (HCCA) level. The multivariate model revealed that both climatic and non-climatic factors were important for explaining spatio-temporal variations in incidence: mean relative humidity during November–June over the study region (posterior mean Incidence Rate Ratio (IRR) = 0.656, 95% Credible Interval (CI) 0.405–0.949) and occurrence of early rains in March in a HCCA (IRR = 0.353, 95% CI 0.239–0.502) were protective factors; a higher risk was associated with the percentage of neighbouring HCCAs having at least one MM A case during the same year (IRR = 2.365, 95% CI 2.078–2.695), the presence of a road crossing the HCCA (IRR = 1.743, 95% CI 1.173–2.474) and the occurrence of cases before 31 December in a HCCA (IRR = 6.801, 95% CI 4.004–10.910). At the study region level, higher annual incidence correlated with greater geographic spread and, to a lesser extent, with higher intensity of localized outbreaks. Conclusions Based on these findings, we hypothesize that spatio-temporal variability of MM A incidence between years and HCCAs result from variations in the intensity or duration of the dry season climatic effects on disease risk, and is further impacted by factors of spatial contacts, representing facilitated pathogen transmission. Additional unexplained factors may contribute to the observed incidence patterns and should be further investigated. PMID:24852960

  9. Experimental and Temporal Observations on the Occurrence and Abundance of Pyrogenic PAH Relative to Atmospheric Oxygen Levels

    NASA Astrophysics Data System (ADS)

    Schuneman, P. J.; Uhle, M. E.

    2004-12-01

    seem to reflect differences in atmospheric oxygen levels. These temporal trends are compared to experimentally-derived pyrogenic PAH produced in a combustion apparatus with different levels of oxygen.

  10. Serum Prolactin Levels in Multiple Sclerosis, Neuromyelitis Optica, and Clinically Isolated Syndrome Patients

    PubMed Central

    TÜRKOĞLU, Recai; GİRİŞ, Murat; GENCER, Mehmet; AKCAN, Uğur; ÖRÇEN, Arda

    2016-01-01

    Introduction Prolactin has been discussed as a factor likely to play a mediating role in multiple sclerosis (MS). Our aim was to investigate the possible association between prolactin production and clinical features of autoimmune demyelinating central nervous system disorders. Methods Serum prolactin levels of 255 MS patients, 19 neuromyelitis optica (NMO) patients, 15 clinically isolated syndrome (CIS) patients, and 240 healthy controls were measured by a heterogeneous sandwich magnetic separation assay. Results MS and NMO cohorts had a significantly higher number of patients with hyperprolactinemia than healthy controls. Sera obtained during attacks of both MS and NMO patients displayed higher prolactin levels than those collected during remission. Prolactin level elevations were found to be more prominent in myelitis attacks in MS. No significant correlation was found between prolactin levels and age, disease duration, disability status, number of attacks, and oligoclonal band positivity. CIS patients who converted to MS had higher prolactin levels than those who did not. Conclusion Our findings support the possible mediating role of prolactin in the immunopathogenesis of MS, NMO, and conversion from CIS to MS.

  11. Intelligent query by humming system based on score level fusion of multiple classifiers

    NASA Astrophysics Data System (ADS)

    Pyo Nam, Gi; Thu Trang Luong, Thi; Ha Nam, Hyun; Ryoung Park, Kang; Park, Sung-Joo

    2011-12-01

    Recently, the necessity for content-based music retrieval that can return results even if a user does not know information such as the title or singer has increased. Query-by-humming (QBH) systems have been introduced to address this need, as they allow the user to simply hum snatches of the tune to find the right song. Even though there have been many studies on QBH, few have combined multiple classifiers based on various fusion methods. Here we propose a new QBH system based on the score level fusion of multiple classifiers. This research is novel in the following three respects: three local classifiers [quantized binary (QB) code-based linear scaling (LS), pitch-based dynamic time warping (DTW), and LS] are employed; local maximum and minimum point-based LS and pitch distribution feature-based LS are used as global classifiers; and the combination of local and global classifiers based on the score level fusion by the PRODUCT rule is used to achieve enhanced matching accuracy. Experimental results with the 2006 MIREX QBSH and 2009 MIR-QBSH corpus databases show that the performance of the proposed method is better than that of single classifier and other fusion methods.

  12. Population-level differences in disease transmission: A Bayesian analysis of multiple smallpox epidemics

    PubMed Central

    Elderd, Bret D.; Dwyer, Greg; Dukic, Vanja

    2013-01-01

    Estimates of a disease’s basic reproductive rate R0 play a central role in understanding outbreaks and planning intervention strategies. In many calculations of R0, a simplifying assumption is that different host populations have effectively identical transmission rates. This assumption can lead to an underestimate of the overall uncertainty associated with R0, which, due to the non-linearity of epidemic processes, may result in a mis-estimate of epidemic intensity and miscalculated expenditures associated with public-health interventions. In this paper, we utilize a Bayesian method for quantifying the overall uncertainty arising from differences in population-specific basic reproductive rates. Using this method, we fit spatial and non-spatial susceptible-exposed-infected-recovered (SEIR) models to a series of 13 smallpox outbreaks. Five outbreaks occurred in populations that had been previously exposed to smallpox, while the remaining eight occurred in Native-American populations that were naïve to the disease at the time. The Native-American outbreaks were close in a spatial and temporal sense. Using Bayesian Information Criterion (BIC), we show that the best model includes population-specific R0 values. These differences in R0 values may, in part, be due to differences in genetic background, social structure, or food and water availability. As a result of these inter-population differences, the overall uncertainty associated with the “population average” value of smallpox R0 is larger, a finding that can have important consequences for controlling epidemics. In general, Bayesian hierarchical models are able to properly account for the uncertainty associated with multiple epidemics, provide a clearer understanding of variability in epidemic dynamics, and yield a better assessment of the range of potential risks and consequences that decision makers face. PMID:24021521

  13. Population-level differences in disease transmission: a Bayesian analysis of multiple smallpox epidemics.

    PubMed

    Elderd, Bret D; Dwyer, Greg; Dukic, Vanja

    2013-09-01

    Estimates of a disease's basic reproductive rate R0 play a central role in understanding outbreaks and planning intervention strategies. In many calculations of R0, a simplifying assumption is that different host populations have effectively identical transmission rates. This assumption can lead to an underestimate of the overall uncertainty associated with R0, which, due to the non-linearity of epidemic processes, may result in a mis-estimate of epidemic intensity and miscalculated expenditures associated with public-health interventions. In this paper, we utilize a Bayesian method for quantifying the overall uncertainty arising from differences in population-specific basic reproductive rates. Using this method, we fit spatial and non-spatial susceptible-exposed-infected-recovered (SEIR) models to a series of 13 smallpox outbreaks. Five outbreaks occurred in populations that had been previously exposed to smallpox, while the remaining eight occurred in Native-American populations that were naïve to the disease at the time. The Native-American outbreaks were close in a spatial and temporal sense. Using Bayesian Information Criterion (BIC), we show that the best model includes population-specific R0 values. These differences in R0 values may, in part, be due to differences in genetic background, social structure, or food and water availability. As a result of these inter-population differences, the overall uncertainty associated with the "population average" value of smallpox R0 is larger, a finding that can have important consequences for controlling epidemics. In general, Bayesian hierarchical models are able to properly account for the uncertainty associated with multiple epidemics, provide a clearer understanding of variability in epidemic dynamics, and yield a better assessment of the range of potential risks and consequences that decision makers face.

  14. Temporal uncertainty analysis of human errors based on interrelationships among multiple factors: a case of Minuteman III missile accident.

    PubMed

    Rong, Hao; Tian, Jin; Zhao, Tingdi

    2016-01-01

    In traditional approaches of human reliability assessment (HRA), the definition of the error producing conditions (EPCs) and the supporting guidance are such that some of the conditions (especially organizational or managerial conditions) can hardly be included, and thus the analysis is burdened with incomprehensiveness without reflecting the temporal trend of human reliability. A method based on system dynamics (SD), which highlights interrelationships among technical and organizational aspects that may contribute to human errors, is presented to facilitate quantitatively estimating the human error probability (HEP) and its related variables changing over time in a long period. Taking the Minuteman III missile accident in 2008 as a case, the proposed HRA method is applied to assess HEP during missile operations over 50 years by analyzing the interactions among the variables involved in human-related risks; also the critical factors are determined in terms of impact that the variables have on risks in different time periods. It is indicated that both technical and organizational aspects should be focused on to minimize human errors in a long run.

  15. Integrating hydrologic and geophysical data to constrain coastal surficial aquifer processes at multiple spatial and temporal scales

    USGS Publications Warehouse

    Schultz, Gregory M.; Ruppel, Carolyn; Fulton, Patrick

    2007-01-01

    Since 1997, repeated, coincident geophysical surveys and extensive hydrologic studies in shallow monitoring wells have been used to study static and dynamic processes associated with surface water-groundwater interaction at a range of spatial scales at the estuarine and ocean boundaries of an undeveloped, permeable barrier island in the Georgia part of the U.S. South Atlantic Bight. Because geophysical and hydrologic data measure different parameters, at different resolution and precision, and over vastly different spatial scales, reconciling the coincident data or even combining complementary inversion, hydrogeochemcial analyses and well-based groundwater monitoring, and, in some cases, limited vegetation mapping to demonstrate the utility of an integrative, multidisciplinary approach for elucidating groundwater processes at spatial scales (tens to thousands of meters) that are often difficult to capture with traditional hydrologic approaches. The case studies highlight regional aquifer characteristics, varying degrees of lateral saltwater intrusion at estuarine boundaries, complex subsurface salinity gradients at the ocean boundary, and imaging of submarsh groundwater discharge and possible free convection in the pore waters of a clastic marsh. This study also documents the use of geophysical techniques for detecting temporal changes in groundwater salinity regimes under natural (not forced) gradients at intratidal to interannual (1998-200 Southeastern U.S.A. drought) time scales.

  16. Temporal and multiple quantitative trait loci analyses of resistance to bacterial wilt in tomato permit the resolution of linked loci.

    PubMed Central

    Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H

    1999-01-01

    Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties. PMID:10049932

  17. Temporal and multiple quantitative trait loci analyses of resistance to bacterial wilt in tomato permit the resolution of linked loci.

    PubMed

    Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H

    1999-03-01

    Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties.

  18. Elevated plasma homocysteine levels in patients with multiple sclerosis are associated with male gender.

    PubMed

    Zoccolella, Stefano; Tortorella, Carla; Iaffaldano, Pietro; Direnzo, Vita; D'Onghia, Mariangela; Paolicelli, Damiano; Livrea, Paolo; Trojano, Maria

    2012-10-01

    Elevated homocysteine (Hcy) levels exert several neurotoxic actions and vascular dysfunctions that may be involved in pathogenesis and progression of multiple sclerosis (MS). The effective role of Hcy in MS however remains to be determined. The aim of this work was to compare plasma Hcy levels in MS patients and neurological disease controls (NDC) and to evaluate their relationships with clinical and demographic variables. In this cross-sectional study, we examined plasma Hcy levels in 217 patients with MS [53 clinically isolated syndromes (CIS) suggestive of MS, 134 relapsing remitting (RR), 23 secondary progressive (SP) and seven primary progressive (PP) MS], recruited among patients attending a tertiary clinical center in southern Italy and in 219 age/sex-matched controls. Median Hcy levels were slightly higher in MS patients compared to NDC (9.1 μmol/l; range, 3.4-35.9 vs. 8.6, range 3.5-27.4; p = 0.02). Median Hcy concentrations were increased in males more than in females in the MS population (10.4 vs. 8.4; p < 0.0001), whereas no differences across genders were found in NDC (9.1 vs. 8.5). Hcy levels were higher in male MS patients compared to the male NDC patients (p = 0.001). Patients with CIS had lower Hcy (7.5 μmol/l; p = 0.004) compared to patients with RR (9.5 μmol/l), SP (10.1 μmol/l) and PP (9.9 μmol/l). Median Hcy concentration was higher in patients with disease duration longer than 22 months (9.7 vs. 8.6 μmol/l; p = 0.02). Plasma Hcy levels are increased in patients with definite MS. Higher Hcy levels are associated with male sex, suggesting a role of Hcy in neurodegenerative processes of MS, which are prominent in male patients.

  19. Levels and temporal trends of toxaphene congeners in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Canada.

    PubMed

    Gouteux, Bruno; Lebeuf, Michel; Muir, Derek C G; Gagné, Jean-Pierre

    2003-10-15

    Environmentally relevant toxaphene congeners were determined in blubber samples of stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary (SLE), Canada. The purpose of this study was to evaluate the levels and the temporal trends (1988-1999) of a suite of six chlorobornanes (P26, P40/41, P44, P50, and P62) in the SLE belugas. P26 and P50 mean concentrations were in the same range as those reported for animals living in the Arctic environment suggesting that the atmospheric transport represents the main input of toxaphene to the SLE. A general exponential decline of chlorobornane concentrations in belugas was observed, except for P26 and P50 in males. On average, concentrations decreased by a factor of two in 8.5 years during the 1988-1999 time period. This rate of decline is similar to the reduction of toxaphene emission from agricultural soils in the southern United States reported over the same time period. Some differences in decline rates were observed among the studied CHB congeners. For instance, P62 decreased more rapidly than P26 and P50 in both male and female belugas. Several hypotheses were advanced to explain these differences such as selective metabolism of specific chlorobornanes by SLE belugas or their prey. However, a most likely explanation is the selective degradation of the technical product in soils and atmosphere in the source region.

  20. Trait-level temporal lobe hypoactivation to social exclusion in unaffected siblings of children and adolescents with autism spectrum disorders

    PubMed Central

    Bolling, Danielle Z.; Pelphrey, Kevin A.; Vander Wyk, Brent C.

    2015-01-01

    Social exclusion elicits powerful feelings of negative affect associated with rejection. Additionally, experiencing social exclusion reliably recruits neural circuitry associated with emotion processing. Recent work has demonstrated abnormal neural responses to social exclusion in children and adolescents with autism spectrum disorders (ASD). However, it remains unknown to what extent these abnormalities are due to atypical social experiences versus genetic predispositions to atypical neural processing. To address this question, the current study investigated brain responses to social exclusion compared to a baseline condition of fair play in unaffected siblings of youth with ASD using functional magnetic resonance imaging. We identified common deviations between unaffected siblings and ASD probands that might represent trait-level abnormalities in processing social exclusion versus fair play, specifically in the right anterior temporoparietal junction extending into posterior superior temporal sulcus. Thus, hypoactivation to social exclusion versus fair play in this region may represent a shared genetic vulnerability to developing autism. In addition, we present evidence supporting the idea that one’s status as an unaffected sibling moderates the relationship between IQ and neural activation to social exclusion versus fair play in anterior cingulate cortex. These results are discussed in the context of previous literature on neural endophenotypes of autism. PMID:26011751

  1. Brain mitochondrial metabolic dysfunction and glutamate level reduction in the pilocarpine model of temporal lobe epilepsy in mice

    PubMed Central

    Smeland, Olav B; Hadera, Mussie G; McDonald, Tanya S; Sonnewald, Ursula; Borges, Karin

    2013-01-01

    Although certain metabolic characteristics such as interictal glucose hypometabolism are well established for temporal lobe epilepsy (TLE), its pathogenesis still remains unclear. Here, we performed a comprehensive study of brain metabolism in a mouse model of TLE, induced by pilocarpine–status epilepticus (SE). To investigate glucose metabolism, we injected mice 3.5–4 weeks after SE with [1,2-13C]glucose before microwave fixation of the head. Using 1H and 13C nuclear magnetic resonance spectroscopy, gas chromatography—mass spectrometry and high-pressure liquid chromatography, we quantified metabolites and 13C labeling in extracts of cortex and hippocampal formation (HF). Hippocampal levels of glutamate, glutathione and alanine were decreased in pilocarpine–SE mice compared with controls. Moreover, the contents of N-acetyl aspartate, succinate and reduced nicotinamide adenine dinucleotide (phosphate) NAD(P)H were decreased in HF indicating impairment of mitochondrial function. In addition, the reduction in 13C enrichment of hippocampal citrate and malate suggests decreased tricarboxylic acid (TCA) cycle turnover in this region. In cortex, we found reduced 13C labeling of glutamate, glutamine and aspartate via the pyruvate carboxylation and pyruvate dehydrogenation pathways, suggesting slower turnover of these amino acids and/or the TCA cycle. In conclusion, mitochondrial metabolic dysfunction and altered amino-acid metabolism is found in both cortex and HF in this epilepsy model. PMID:23611869

  2. Cockles, barnacles and ascidians compose a subtidal facilitation cascade with multiple hierarchical levels of foundation species.

    PubMed

    Yakovis, Eugeniy; Artemieva, Anna

    2017-03-22

    Facilitation cascades occur when multiple foundation species in a community are involved in a hierarchy of positive interactions, and consist of a primary facilitator which positively affects secondary facilitators, each supporting a suit of dependent species. There is no theoretical limit to the number of levels in a facilitation cascade, yet the existence of more than two has rarely been examined. We manipulated biogenic substrate produced by a primary facilitator (cockle shells) and a secondary facilitator (barnacles and their empty tests) in a space-limited subtidal community to test the hypothesis that solitary ascidians would be the third-level facilitator. In the field, most ascidians were found on barnacles, and most barnacles occupied cockle shells. To produce this pattern, barnacles could nurse ascidians (a longer 'facilitation chain') or outcompete them from cockle shells (a shorter chain). Experimental results clearly supported the nursing hypothesis providing evidence for a facilitation cascade with three hierarchical levels of foundation species. Our findings confirm that like predation and competition, positive interspecific interactions nest into multi-tier hierarchies with numerous levels. While the number of foundation species should increase community stability and resilience as it increases diversity and reduces environmental stress, facilitation chain length may have the opposite effect.

  3. Dysregulated Homeostasis of Acetylcholine Levels in Immune Cells of RR-Multiple Sclerosis Patients.

    PubMed

    Di Bari, Maria; Reale, Marcella; Di Nicola, Marta; Orlando, Viviana; Galizia, Sabrina; Porfilio, Italo; Costantini, Erica; D'Angelo, Chiara; Ruggieri, Serena; Biagioni, Stefano; Gasperini, Claudio; Tata, Ada Maria

    2016-11-30

    Multiple sclerosis (MS) is characterized by pro-inflammatory cytokine production. Acetylcholine (ACh) contributes to the modulation of central and peripheral inflammation. We studied the homeostasis of the cholinergic system in relation to cytokine levels in immune cells and sera of relapsing remitting-MS (RR-MS) patients. We demonstrated that lower ACh levels in serum of RR-MS patients were inversely correlated with the increased activity of the hydrolyzing enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Interestingly, the expression of the ACh biosynthetic enzyme and the protein carriers involved in non-vesicular ACh release were found overexpressed in peripheral blood mononuclear cells of MS patients. The inflammatory state of the MS patients was confirmed by increased levels of TNFα, IL-12/IL-23p40, IL-18. The lower circulating ACh levels in sera of MS patients are dependent on the higher activity of cholinergic hydrolyzing enzymes. The smaller ratio of ACh to TNFα, IL-12/IL-23p40 and IL-18 in MS patients, with respect to healthy donors (HD), is indicative of an inflammatory environment probably related to the alteration of cholinergic system homeostasis.

  4. Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

    PubMed

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-06-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

  5. Serum Gelatinases Levels in Multiple Sclerosis Patients during 21 Months of Natalizumab Therapy

    PubMed Central

    Bellini, Tiziana; Trentini, Alessandro; Delbue, Serena; Elia, Francesca; Gastaldi, Matteo; Franciotta, Diego; Bergamaschi, Roberto; Manfrinato, Maria Cristina; Volta, Carlo Alberto; Granieri, Enrico; Fainardi, Enrico

    2016-01-01

    Background. Natalizumab is a highly effective treatment approved for multiple sclerosis (MS). The opening of the blood-brain barrier mediated by matrix metalloproteinases (MMPs) is considered a crucial step in MS pathogenesis. Our goal was to verify the utility of serum levels of active MMP-2 and MMP-9 as biomarkers in twenty MS patients treated with Natalizumab. Methods. Serum levels of active MMP-2 and MMP-9 and of specific tissue inhibitors TIMP-1 and TIMP-2 were determined before treatment and for 21 months of therapy. Results. Serum levels of active MMP-2 and MMP-9 and of TIMP-1 and TIMP-2 did not differ during the treatment. The ratio between MMP-9 and MMP-2 was increased at the 15th month compared with the 3rd, 6th, and 9th months, greater at the 18th month than at the 3rd and 6th months, and higher at the 21st than at the 3rd and 6th months. Discussion. Our data indicate that an imbalance between active MMP-9 and active MMP-2 can occur in MS patients after 15 months of Natalizumab therapy; however, they do not support the use of serum active MMP-2 and active MMP-9 and TIMP-1 and TIMP-2 levels as biomarkers for monitoring therapeutic response to Natalizumab. PMID:27340316

  6. Comparing multiple imputation methods for systematically missing subject-level data.

    PubMed

    Kline, David; Andridge, Rebecca; Kaizar, Eloise

    2015-12-17

    When conducting research synthesis, the collection of studies that will be combined often do not measure the same set of variables, which creates missing data. When the studies to combine are longitudinal, missing data can occur on the observation-level (time-varying) or the subject-level (non-time-varying). Traditionally, the focus of missing data methods for longitudinal data has been on missing observation-level variables. In this paper, we focus on missing subject-level variables and compare two multiple imputation approaches: a joint modeling approach and a sequential conditional modeling approach. We find the joint modeling approach to be preferable to the sequential conditional approach, except when the covariance structure of the repeated outcome for each individual has homogenous variance and exchangeable correlation. Specifically, the regression coefficient estimates from an analysis incorporating imputed values based on the sequential conditional method are attenuated and less efficient than those from the joint method. Remarkably, the estimates from the sequential conditional method are often less efficient than a complete case analysis, which, in the context of research synthesis, implies that we lose efficiency by combining studies. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Neurophysiological analysis of the suprachiasmatic nucleus: a challenge at multiple levels.

    PubMed

    Meijer, Johanna H; Michel, Stephan

    2015-01-01

    Understanding the neurophysiology of the circadian timing system requires investigation at multiple levels of organization. Neurons of the suprachiasmatic nucleus (SCN) function as autonomous single-cell oscillators, which warrant studies at the single-cell level. Combining patch-clamp recordings of ion channels with imaging techniques to measure clock gene expression and intracellular calcium has proven extremely valuable to study cellular properties. To achieve and maintain rhythmic activity, SCN neurons require sufficient stimulation (i.e., input) from surrounding cells. At the network level, SCN rhythms are robust and can be measured in vitro, for example, in brain slices that contain the SCN. These recordings revealed that the collective behavior of the SCN neuronal network is strongly determined by the phase dispersal of the neurons. This phase dispersal is plastic, with high synchronization in short photoperiod, desynchronization in long photoperiod, and antiphase oscillations in aging and/or continuous light. In vivo recordings are needed in order to study the SCN as part of a larger network (i.e., interacting with other brain centers) and to study the SCN's response to light. Interestingly, superimposed on the circadian waveform are higher frequency fluctuations that are present in vivo but not in vitro. These fluctuations are attributed to input from other brain centers and computational analyses suggest that these fluctuations are beneficial to the system. Hence, the SCN's properties arise from several organizational levels, and a combination of approaches is needed in order to fully understand the circadian system.

  8. Dysregulated Homeostasis of Acetylcholine Levels in Immune Cells of RR-Multiple Sclerosis Patients

    PubMed Central

    Di Bari, Maria; Reale, Marcella; Di Nicola, Marta; Orlando, Viviana; Galizia, Sabrina; Porfilio, Italo; Costantini, Erica; D’Angelo, Chiara; Ruggieri, Serena; Biagioni, Stefano; Gasperini, Claudio; Tata, Ada Maria

    2016-01-01

    Multiple sclerosis (MS) is characterized by pro-inflammatory cytokine production. Acetylcholine (ACh) contributes to the modulation of central and peripheral inflammation. We studied the homeostasis of the cholinergic system in relation to cytokine levels in immune cells and sera of relapsing remitting-MS (RR-MS) patients. We demonstrated that lower ACh levels in serum of RR-MS patients were inversely correlated with the increased activity of the hydrolyzing enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Interestingly, the expression of the ACh biosynthetic enzyme and the protein carriers involved in non-vesicular ACh release were found overexpressed in peripheral blood mononuclear cells of MS patients. The inflammatory state of the MS patients was confirmed by increased levels of TNFα, IL-12/IL-23p40, IL-18. The lower circulating ACh levels in sera of MS patients are dependent on the higher activity of cholinergic hydrolyzing enzymes. The smaller ratio of ACh to TNFα, IL-12/IL-23p40 and IL-18 in MS patients, with respect to healthy donors (HD), is indicative of an inflammatory environment probably related to the alteration of cholinergic system homeostasis. PMID:27916909

  9. The drinking water contamination crisis in Flint: Modeling temporal trends of lead level since returning to Detroit water system.

    PubMed

    Goovaerts, Pierre

    2017-03-01

    Since Flint returned to its pre-crisis source of drinking water close to 25,000 water samples have been collected and tested for lead and copper in >10,000 residences. This paper presents the first analysis and time trend modeling of lead data, providing new insights about the impact of this intervention. The analysis started with geocoding all water lead levels (WLL) measured during an 11-month period following the return to the Detroit water supply. Each data was allocated to the corresponding tax parcel unit and linked to secondary datasets, such as the composition of service lines, year built, or census tract poverty level. Only data collected on residential parcels within the City limits were used in the analysis. One key feature of Flint data is their collection through two different sampling initiatives: (i) voluntary or homeowner-driven sampling whereby concerned citizens decided to acquire a testing kit and conduct sampling on their own (non-sentinel sites), and (ii) State-controlled sampling where data were collected bi-weekly at selected sites after training of residents by technical teams (sentinel sites). Temporal trends modeled from these two datasets were found to be statistically different with fewer sentinel data exceeding WLL thresholds ranging from 10 to 50μg/L. Even after adjusting for housing characteristics the odds ratio (OR) of measuring WLL above 15μg/L at non-sentinel sites is significantly >1 (OR=1.480) and it increases with the threshold (OR=2.055 for 50μg/L). Joinpoint regression showed that the city-wide percentage of WLL data above 15μg/L displayed four successive trends since the return to Detroit Water System. Despite the recent improvement in water quality, the culprit for differences between sampling programs needs to be identified as it impacts exposure assessment and might influence whether there is compliance or not with the Lead and Copper Rule.

  10. [Level indicators construction and temporal-spatial distribution features of agricultural flood in the southwest of China].

    PubMed

    Wu, Li; Huo, Zhi-guo; Zhang, Lei; Yu, Cai-xia; Yang, Jian-ying; Zhang, Gui-xiang

    2015-08-01

    Flood level indicators of southwest provinces were built in this study by using daily precipitation data of 341 weather stations in southwest agricultural areas from 1961 to 2010 combined with grey correlation analysis. In the process of building the indicators, we took single station flood indicators of Chongqing as the prototype. Through increasing and decreasing the precipitation threshold of Chongqing indicators by the amplitude of -50-+50 mm and the step size of 1 mm, each province got 101 groups of flood indicators. Based on the correlation between flood intensity calculated by all the indicators and crop flood real seriousness, coincidence between indicators and historical flood records and the comparability of different province indicators, we finally constructed agricultural flood level indicators of each province step by step. According to the flood indicators, we also analyzed temporal-spatial distribution features of flood disaster in southwest agricultural areas. The results were as follows: the final indicators of Yunnan were the original indicators plus 16 mm, while it was plus 30 mm for Guizhou and plus 40 mm for Sichuan-Chongqing. The correlation coefficients between flood index defined by indicators and affected ratio were 0.314 (P < 0.05), 0.553 (P < 0.01) and 0.305 (P < 0.05), respectively. The coincidence was relatively high between indicators and historical flood records. The ages in which flood disaster appeared very serious were 1980s in Yunnan, 1990s in Guizhou and 1980s and 2000s in Sichuan-Chongqing in the nearly 50 years. In the southwest and southeast of Yunnan, southwest of Guizhou and west and northeast of Sichuan Basin, the flood disaster was prevalent.

  11. Temporally and spatially resolved photoluminescence investigation of (112{sup ¯}2) semi-polar InGaN/GaN multiple quantum wells grown on nanorod templates

    SciTech Connect

    Liu, B.; Smith, R.; Athanasiou, M.; Yu, X.; Bai, J.; Wang, T.

    2014-12-29

    By means of time-resolved photoluminescence (PL) and confocal PL measurements, temporally and spatially resolved optical properties have been investigated on a number of In{sub x}Ga{sub 1−x}N/GaN multiple-quantum-well (MQW) structures with a wide range of indium content alloys from 13% to 35% on (112{sup ¯}2) semi-polar GaN with high crystal quality, obtained through overgrowth on nanorod templates. With increasing indium content, the radiative recombination lifetime initially increases as expected, but decreases if the indium content further increases to 35%, corresponding to emission in the green spectral region. The reduced radiative recombination lifetime leads to enhanced optical performance for the high indium content MQWs as a result of strong exciton localization, which is different from the behaviour of c-plane InGaN/GaN MQWs, where quantum confined Stark effect plays a dominating role in emission process.

  12. The severity of Minamata disease declined in 25 years: temporal profile of the neurological findings analyzed by multiple logistic regression model.

    PubMed

    Uchino, Makoto; Hirano, Teruyuki; Satoh, Hiroshi; Arimura, Kimiyoshi; Nakagawa, Masanori; Wakamiya, Jyunji

    2005-01-01

    Minamata disease (MD) was caused by ingestion of seafood from the methylmercury-contaminated areas. Although 50 years have passed since the discovery of MD, there have been only a few studies on the temporal profile of neurological findings in certified MD patients. Thus, we evaluated changes in neurological symptoms and signs of MD using discriminants by multiple logistic regression analysis. The severity of predictive index declined in 25 years in most of the patients. Only a few patients showed aggravation of neurological findings, which was due to complications such as spino-cerebellar degeneration. Patients with chronic MD aged over 45 years had several concomitant diseases so that their clinical pictures were complicated. It was difficult to differentiate chronic MD using statistically established discriminants based on sensory disturbance alone. In conclusion, the severity of MD declined in 25 years along with the modification by age-related concomitant disorders.

  13. Multiple cis-elements and trans-acting factors regulate dynamic spatio-temporal transcription of let-7 in Caenorhabditis elegans.

    PubMed

    Kai, Zoya S; Finnegan, Emily F; Huang, Stacey; Pasquinelli, Amy E

    2013-02-01

    The let-7 microRNA (miRNA) is highly conserved across animal phyla and generally regulates cellular differentiation and developmental timing pathways. In Caenorhabditis elegans, the mature let-7 miRNA starts to accumulate in the last stages of larval development where it directs cellular differentiation programs required for adult fates. Here, we show that expression of the let-7 gene in C. elegans is under complex transcriptional control. The onset of let-7 transcription begins as early as the first larval stage in some tissues, and as late as the third larval stage in others, and is abrogated at the gravid adult stage. Transcription from two different start sites in the let-7 promoter oscillates during each larval stage. We show that transcription is regulated by two distinct cis-elements in the promoter of let-7, the previously described temporal regulatory element (TRE), and a novel element downstream of the TRE that we have named the let-7 transcription element (LTE). These elements play distinct and redundant roles in regulating let-7 expression in specific tissues. In the absence of the TRE and LTE, transcription of let-7 is undetectable and worms exhibit the lethal phenotype characteristic of let-7 null mutants. We also identify several genes that affect the transcription of let-7 generally and tissue-specifically. Overall, spatio-temporal regulation of let-7 transcription is orchestrated by multiple cis- and trans-acting factors to ensure appropriate expression of this essential miRNA during worm development.

  14. Investigating tree mortality at multiple spatial and temporal scales in the Bishop pine forest on Santa Cruz Island, California

    NASA Astrophysics Data System (ADS)

    Baguskas, S. A.; Bookhagen, B.; Peterson, S. H.; Asner, G. P.

    2010-12-01

    The rate of tree mortality has increased across the western United States in recent decades, and many studies attribute the cause to water stress induced by regional warming. To date, the geographical scope of study regions affected by widespread tree mortality in the American West has largely been limited to continental, montane climates. Much less is known about mortality events in other climatic regions, such as coastal forests. The relatively unvarying nature of the coastal, maritime climate has traditionally been assumed to buffer these forests from large climate variations; however, we have observed rapid tree mortality in this region which suggests coastal forests may be as susceptible to drought-induced mortality as inland forest locations. Santa Cruz Island (SCI), one of the California Channel Islands, harbors numerous relict and endemic plant species, including Bishop pine (Pinus muricata). Following extreme drought in southern California in two of the last three years (2007-2009), widespread mortality of Bishop pines has become evident. Bishop pine populations are restricted to the fog belt of coastal California and northern Baja California; therefore, a major reduction of existing populations on SCI would greatly reduce the distribution of the species as a whole. The focus of my research is to investigate the mechanisms underlying spatial and temporal patterns of Bishop pine mortality on SCI. I used remote sensing techniques to characterize spatiotemporal patterns of tree mortality and I have performed ground-data collection to validate remote-sensing results. Remote sensing in combination with field verification is a valuable tool to understand the spatiotemporal pattern of tree mortality and is a necessary step to help elucidate potential environmental and biological controls on tree mortality.

  15. Limited pattern of TCR delta chain gene rearrangement on the RNA level in multiple sclerosis.

    PubMed

    Nowak, J; Januszkiewicz, D; Pernak, M; Hertmanowska, H; Nowicka-Kujawska, K; Rembowska, J; Lewandowski, K; Nowak, T; Wender, M

    2001-01-01

    Susceptibility to multiple sclerosis (MS) is most likely affected by a number of genes, including HLA and T-cell receptor (TCR) genes. T cells expressing gamma/delta receptors seem to contribute to autoagression in MS, as evidenced by their localization in the MS plaques in the brain. The aim of this study was to analyse the TCRdelta chain gene rearrangement at the RNA (cDNA) level and compare to the DNA pattern rearrangement. TCRdelta gene rearrangement was analysed in MS patients and healthy individuals with the use of primers specific for Vdelta1-6 and Jdelta1 genes (at the DNA level) and specific for Vdelta1-6 and Cdelta1 genes (at the cDNA level). The size of PCR products was analysed on agarose gel and by ALF-Express (Pharmacia). Additionally, the lymphocyte surface immunophenotype was studied with specific monoclonal antibodies. At the DNA level a restricted pattern of Vdelta3-Jdelta1 and Vdelta5-Jdelta1 was found only in MS patients. Contrary to DNA, mono-, oligoclonal RNA (cDNA) rearrangements were limited to Vdelta1-Cdelta1, Vdelta2-Cdelta1 and Vdelta3-Cdelta1 only in MS patients as well. Surface immunophenotype analysis revealed in MS a much higher frequency of activated gamma/delta T lymphocytes, i.e. expressing HLA-DR and CD25. An elevated level of CD56 positive cells in MS was recorded. Mono-oligoclonal pattern of TCRdelta gene rearrangement at the RNA level, along with increase in activated gamma/delta T cells, strongly argue for a significant role of gamma/delta T lymphocytes in the pathogenesis of MS.

  16. High levels of multiple paternity in Littorina saxatilis: hedging the bets?

    PubMed

    Mäkinen, Tuuli; Panova, Marina; André, Carl

    2007-01-01

    The mating system of a species can have great effects on its genetic structure and evolution. We studied the extent of multiple paternity in a gastropod with internal fertilization, the intertidal snail Littorina saxatilis. Paternal genotype reconstruction based on microsatellite markers was performed on the offspring of wild, naturally fertilized females from 2 populations. The numbers of males contributing to the offspring per female were among the highest detected in invertebrates so far, with the exception of social insects. No reproductive skew in favor of males that were genetically more distant from the females was detected, and the pattern of fertilization appeared random. The result fits a hypothesis of indiscriminate mating, with genetic bet hedging as the most likely explanation. Bet hedging may have evolved as a form of inbreeding avoidance, if the snails are not able to recognize relatives. However, nutritional benefits from sperm or sexual conflict with males are additional possibilities that remain to be assessed in this species. Whatever the causes, such high levels of multiple paternity are remarkable and are likely to have a large impact on population structure and dynamics in a species in which migration between populations is spurious.

  17. Resonance fluorescence of strongly driven two-level system coupled to multiple dissipative reservoirs

    SciTech Connect

    Yan, Yiying Lü, Zhiguo Zheng, Hang

    2016-08-15

    We present a theoretical formalism for resonance fluorescence radiating from a two-level system (TLS) driven by any periodic driving and coupled to multiple reservoirs. The formalism is derived analytically based on the combination of Floquet theory and Born–Markov master equation. The formalism allows us to calculate the spectrum when the Floquet states and quasienergies are analytically or numerically solved for simple or complicated driving fields. We can systematically explore the spectral features by implementing the present formalism. To exemplify this theory, we apply the unified formalism to comprehensively study a generic model that a harmonically driven TLS is simultaneously coupled to a radiative reservoir and a dephasing reservoir. We demonstrate that the significant features of the fluorescence spectra, the driving-induced asymmetry and the dephasing-induced asymmetry, can be attributed to the violation of detailed balance condition, and explained in terms of the driving-related transition quantities between Floquet-states and their steady populations. In addition, we find the distinguished features of the fluorescence spectra under the biharmonic and multiharmonic driving fields in contrast with that of the harmonic driving case. In the case of the biharmonic driving, we find that the spectra are significantly different from the result of the RWA under the multiple resonance conditions. By the three concrete applications, we illustrate that the present formalism provides a routine tool for comprehensively exploring the fluorescence spectrum of periodically strongly driven TLSs.

  18. Resonance fluorescence of strongly driven two-level system coupled to multiple dissipative reservoirs

    NASA Astrophysics Data System (ADS)

    Yan, Yiying; Lü, Zhiguo; Zheng, Hang

    2016-08-01

    We present a theoretical formalism for resonance fluorescence radiating from a two-level system (TLS) driven by any periodic driving and coupled to multiple reservoirs. The formalism is derived analytically based on the combination of Floquet theory and Born-Markov master equation. The formalism allows us to calculate the spectrum when the Floquet states and quasienergies are analytically or numerically solved for simple or complicated driving fields. We can systematically explore the spectral features by implementing the present formalism. To exemplify this theory, we apply the unified formalism to comprehensively study a generic model that a harmonically driven TLS is simultaneously coupled to a radiative reservoir and a dephasing reservoir. We demonstrate that the significant features of the fluorescence spectra, the driving-induced asymmetry and the dephasing-induced asymmetry, can be attributed to the violation of detailed balance condition, and explained in terms of the driving-related transition quantities between Floquet-states and their steady populations. In addition, we find the distinguished features of the fluorescence spectra under the biharmonic and multiharmonic driving fields in contrast with that of the harmonic driving case. In the case of the biharmonic driving, we find that the spectra are significantly different from the result of the RWA under the multiple resonance conditions. By the three concrete applications, we illustrate that the present formalism provides a routine tool for comprehensively exploring the fluorescence spectrum of periodically strongly driven TLSs.

  19. Increased serum levels of C21 steroids in female patients with multiple sclerosis.

    PubMed

    Kanceva, R; Stárka, L; Kancheva, L; Hill, M; Veliková, M; Havrdová, E

    2015-01-01

    Multiple sclerosis (MS) is one of the most common neurological diseases. This neurodegenerative autoimmune disease manifests as inflammatory and demyelinating impairment of the central nervous system (CNS). Although some studies demonstrated associations between altered steroidogenesis and pathophysiology of MS as well as the importance of steroids in the pathophysiology of MS, the knowledge concerning the steroid metabolome in female patients is limited. Hence, 51 steroids and steroid polar conjugates were measured in the serum of 12 women with MS, untreated with steroids and 6 age-corresponding female controls with the use of gas chromatography - mass spectrometry (GC-MS). The data were processed using age adjusted ANCOVA, receiver operating characteristics (ROC) analysis and orthogonal projections to latent structures (OPLS). Our data show higher levels of circulating C21 steroids including steroid modulators of ionotropic type A gamma-aminobutyric acid (GABA A) receptors and glutamate receptors. Furthermore, the levels of GABAergic androsterone and 5-androsten-3beta,7alpha,17beta-triol were also higher in the female MS patients. In conclusion, the data demonstrate higher levels of circulating C21 steroids and their polar conjugates and some bioactive C19 steroids in women with MS, which may influence neuronal activity and affect the balance between neuroprotection and excitotoxicity.

  20. Climate change and freshwater ecosystems: impacts across multiple levels of organization

    PubMed Central

    Woodward, Guy; Perkins, Daniel M.; Brown, Lee E.

    2010-01-01

    Fresh waters are particularly vulnerable to climate change because (i) many species within these fragmented habitats have limited abilities to disperse as the environment changes; (ii) water temperature and availability are climate-dependent; and (iii) many systems are already exposed to numerous anthropogenic stressors. Most climate change studies to date have focused on individuals or species populations, rather than the higher levels of organization (i.e. communities, food webs, ecosystems). We propose that an understanding of the connections between these different levels, which are all ultimately based on individuals, can help to develop a more coherent theoretical framework based on metabolic scaling, foraging theory and ecological stoichiometry, to predict the ecological consequences of climate change. For instance, individual basal metabolic rate scales with body size (which also constrains food web structure and dynamics) and temperature (which determines many ecosystem processes and key aspects of foraging behaviour). In addition, increasing atmospheric CO2 is predicted to alter molar CNP ratios of detrital inputs, which could lead to profound shifts in the stoichiometry of elemental fluxes between consumers and resources at the base of the food web. The different components of climate change (e.g. temperature, hydrology and atmospheric composition) not only affect multiple levels of biological organization, but they may also interact with the many other stressors to which fresh waters are exposed, and future research needs to address these potentially important synergies. PMID:20513717

  1. Diffusion tensor imaging detects corticospinal tract involvement at multiple levels in amyotrophic lateral sclerosis

    PubMed Central

    Toosy, A; Werring, D; Orrell, R; Howard, R; King, M; Barker, G; Miller, D; Thompson, A

    2003-01-01

    Background: Histopathological studies of amyotrophic lateral sclerosis (ALS) are of end stage disease. Diffusion tensor imaging (DTI) provides the opportunity to investigate indirectly corticospinal tract pathology of ALS in vivo. Methods: DTI was used to study the water diffusion characteristics of the corticospinal tracts in 21 patients with ALS and 14 normal controls. The authors measured the fractional anisotropy (FA) and mean diffusivity (MD) along the pyramidal tracts from the internal capsules down to the pyramids. A mixed model regression analysis was used to compare FA and MD between the ALS and control groups. Results: FA showed a downward linear trend from the cerebral peduncles to the pyramids and was lower in the ALS group than controls at multiple levels of the corticospinal tract. At the internal capsules, FA was higher on the right. MD showed an upward trend, progressing caudally from the internal capsules to the pyramids. MD was higher at the level of the internal capsule in the ALS group, but caudally this difference was not maintained. No correlations were found between clinical markers of disability and water diffusion indices. Conclusions: These findings provide insights into the pathological processes of ALS. Differences in diffusion characteristics at different anatomical levels may relate to underlying tract architecture or the distribution of pathological damage in ALS. Further development may permit monitoring of progression and treatment of disease. PMID:12933929

  2. A Compendium of Caenorhabditis elegans RNA Binding Proteins Predicts Extensive Regulation at Multiple Levels

    PubMed Central

    Tamburino, Alex M.; Ryder, Sean P.; Walhout, Albertha J. M.

    2013-01-01

    Gene expression is regulated at multiple levels, including transcription and translation, as well as mRNA and protein stability. Although systems-level functions of transcription factors and microRNAs are rapidly being characterized, few studies have focused on the posttranscriptional gene regulation by RNA binding proteins (RBPs). RBPs are important to many aspects of gene regulation. Thus, it is essential to know which genes encode RBPs, which RBPs regulate which gene(s), and how RBP genes are themselves regulated. Here we provide a comprehensive compendium of RBPs from the nematode Caenorhabditis elegans (wRBP1.0). We predict that as many as 887 (4.4%) of C. elegans genes may encode RBPs ~250 of which likely function in a gene-specific manner. In addition, we find that RBPs, and most notably gene-specific RBPs, are themselves enriched for binding and modification by regulatory proteins, indicating the potential for extensive regulation of RBPs at many different levels. wRBP1.0 will provide a significant contribution toward the comprehensive delineation of posttranscriptional regulatory networks and will provide a resource for further studies regulation by RBPs. PMID:23390605

  3. Decreased Endothelin-1 Plasma Levels in Multiple Sclerosis Patients: A Possible Factor of Vascular Dysregulation?

    PubMed Central

    Jankowska-Lech, Irmina; Terelak-Borys, Barbara; Grabska-Liberek, Iwona; Palasik, Witold; Bik, Wojciech; Wolińska-Witort, Ewa

    2015-01-01

    Background Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system with possible involvement of vascular dysregulation secondary to endothelial dysfunction caused by destruction of the vessel wall. Vascular dysregulation leads to excessive vasoconstriction or insufficient vasodilatation, resulting in vasospasm mediated by endothelin-1 (ET-1), the most potent and long-lasting mediator. Vascular dysregulation can play an important role in the pathogenesis of some eye disorders and it has been hypothesized that it is a vascular risk factor for glaucomatous optic neuropathy. The aim of this study was to estimate endothelin-1 (ET-1) plasma levels in patients with MS. Material/Methods The MS group consisted of 39 patients (9 males, 30 females), mean age: 38.8±10.02 years, range: 22–62. The control group consisted of 27 healthy volunteers (3 males and 24 females), mean age: 37.4±10.88 years, range: 20–62; clinically, in a non-active stage of the disease. ET-1 plasma levels were measured using the Endothelin-1 ELISA Kit (Immuno-Biological Laboratories Co., Japan). Statistical analysis was performed with the nonparametric Mann-Whitney U test for independent groups. Results Endothelin-1 (ET-1) plasma levels were significantly lower in MS patients compared to healthy controls: mean value 0.55±0.44 pg/ml (146.05±118.27 fmol/ml) vs. 0.95±0.48 pg/ml (252.83±127.16 fmol/ml); P=0.012. Conclusions Significantly decreased ET-1 plasma levels in the MS patients could reflect the non-active disease at the time of ET-1 measurements or the effects of immunomodulatory treatment, but it cannot be excluded that decreased ET-1 plasma levels in these patients might result from vascular dysregulation. PMID:25864450

  4. Anti-annexin antibodies, cholesterol levels and disability in multiple sclerosis.

    PubMed

    Mandoj, Chiara; Renna, Rosaria; Plantone, Domenico; Sperduti, Isabella; Cigliana, Giovanni; Conti, Laura; Koudriavtseva, Tatiana

    2015-10-08

    So far, no studies have been conducted to evaluate possible correlations between lipid/lipoprotein levels and the anti-phospholipid antibody (aPL) positivity in multiple sclerosis (MS). In this cross-sectional study, we aimed to investigate the relationships between serum lipid profile and aPL positivity rates in MS patients, and their possible differences among secondary-progressive MS (SPMS) patients, relapsing-remitting MS patients in remission (REM) and in relapse (REL). We included 16 SPMS, 58 REM and 26 REL. Their sera were tested for aPL (anti-cardiolipin, anti-β2glycoproteinI, anti-prothrombin, anti-annexinV), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and lipoprotein(a) levels. High TC levels were more frequent in SPMS patients than other groups (p=0.05). The REL had significantly higher rates of positivity for anti-β2glycoproteinI IgM (p<0.0001), anti-prothrombin IgG and IgM (both p=0.05) than the other groups. A significant positive correlation was found between age and both TC and LDL-C, disability and both TC and LDL-C, disease duration and LDL-C. TC levels were significantly higher (p=0.007) in anti-annexinV-IgG positive patients. The anti-annexinV-IgG positivity significantly associated with high levels of TC (p=0.002) and LDL-C (p=0.03). Our results support the hypothesis that both thrombogenic and neurodegenerative mechanisms associated with an abnormal cholesterol homeostasis might contribute to MS progression. Our study may have interesting practical implications, which could potentially open new therapeutic approaches in the context of appropriately designed clinical trials.

  5. Association of Children’s Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media

    PubMed Central

    Beamer, Paloma I.; Klimecki, Walter T.; Loh, Miranda; Van Horne, Yoshira Ornelas; Sugeng, Anastasia J.; Lothrop, Nathan; Billheimer, Dean; Guerra, Stefano; Lantz, Robert Clark; Canales, Robert A.; Martinez, Fernando D.

    2016-01-01

    Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = −0.43, p = 0.001, R2 = 0.08), water (b = −0.22, p = 0.07, R2 = 0.03), house dust (b = −0.37, p = 0.07, R2 = 0.04), and dust loading (b = −0.21, p = 0.04, R2 = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = −0.42, p = 0.02, R2 = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities. PMID:27223295

  6. Systemic Inflammatory Response and Serum Lipopolysaccharide Levels Predict Multiple Organ Failure and Death in Alcoholic Hepatitis

    PubMed Central

    Michelena, Javier; Altamirano, José; Abraldes, Juan G.; Affò, Silvia; Morales-Ibanez, Oriol; Sancho-Bru, Pau; Dominguez, Marlene; García-Pagán, Juan Carlos; Fernández, Javier; Arroyo, Vicente; Ginès, Pere; Louvet, Alexandre; Mathurin, Philippe; Mehal, Wajahat Z.; Caballería, Juan; Bataller, Ramón

    2015-01-01

    Alcoholic hepatitis (AH) frequently progresses to multiple organ failure (MOF) and death. However, the driving factors are largely unknown. At admission, patients with AH often show criteria of systemic inflammatory response syndrome (SIRS) even in the absence of an infection. We hypothesize that the presence of SIRS may predispose to MOF and death. To test this hypothesis, we studied a cohort including 162 patients with biopsy-proven AH. The presence of SIRS and infections was assessed in all patients, and multivariate analyses identified variables independently associated with MOF and 90-day mortality. At admission, 32 (19.8%) patients were diagnosed with a bacterial infection, while 75 (46.3%) fulfilled SIRS criteria; 58 patients (35.8%) developed MOF during hospitalization. Short-term mortality was significantly higher among patients who developed MOF (62.1% versus 3.8%, P <0.001). The presence of SIRS was a major predictor of MOF (odds ratio = 2.69, P=0.025) and strongly correlated with mortality. Importantly, the course of patients with SIRS with and without infection was similar in terms of MOF development and short-term mortality. Finally, we sought to identify serum markers that differentiate SIRS with and without infection. We studied serum levels of high-sensitivity C-reactive protein, procalcitonin, and lipopolysaccharide at admission. All of them predicted mortality. Procalcitonin, but not high-sensitivity C-reactive protein, serum levels identified those patients with SIRS and infection. Lipopolysaccharide serum levels predicted MOF and the response to prednisolone. Conclusion In the presence or absence of infections, SIRS is a major determinant of MOF and mortality in AH, and the mechanisms involved in the development of SIRS should be investigated; procalcitonin serum levels can help to identify patients with infection, and lipopolysaccharide levels may help to predict mortality and the response to steroids. PMID:25761863

  7. Depression from childhood through adolescence: Risk mechanisms across multiple systems and levels of analysis

    PubMed Central

    Hankin, Benjamin L.

    2015-01-01

    This paper selectively reviews recent research, especially in the last two years (2012-2014) in preschool, child, and adolescent depression. In particular, attention is paid to developmental epidemiology as well as risk factors and processes that contribute to depression trajectories over time. Emphasis is placed on a developmental psychopathology perspective in which risks are instantiated across multiple systems and levels of analysis, including genetics, stress contexts and processes, biological stress mechanisms, temperament, emotion, reward, cognitive factors and processes, and interpersonal influences. These risks dynamically transact over time, as they emerge and stabilize into relatively trait-like vulnerabilities that confer risk for the increasing rates of depression observed in adolescence. Overall, this summary illustrates that considerable progress has been made recently in understanding the complex developmental processes contributing to depression. Finally, a few gaps are highlighted as opportunities for future research. PMID:25692174

  8. Modulation of C. elegans Touch Sensitivity Is Integrated at Multiple Levels

    PubMed Central

    Chen, Xiaoyin

    2014-01-01

    Sensory systems can adapt to different environmental signals. Here we identify four conditions that modulate anterior touch sensitivity in Caenorhabditis elegans after several hours and demonstrate that such sensory modulation is integrated at multiple levels to produce a single output. Prolonged vibration involving integrin signaling directly sensitizes the touch receptor neurons (TRNs). In contrast, hypoxia, the dauer state, and high salt reduce touch sensitivity by preventing the release of long-range neuroregulators, including two insulin-like proteins. Integration of these latter inputs occurs at upstream neurohormonal cells and at the insulin signaling cascade within the TRNs. These signals and those from integrin signaling converge to modulate touch sensitivity by regulating AKT kinases and DAF-16/FOXO. Thus, activation of either the integrin or insulin pathways can compensate for defects in the other pathway. This modulatory system integrates conflicting signals from different modalities, and adapts touch sensitivity to both mechanical and non-mechanical conditions. PMID:24806678

  9. A multivariate model for the meta-analysis of study level survival data at multiple times.

    PubMed

    Jackson, Dan; Rollins, Katie; Coughlin, Patrick

    2014-09-01

    Motivated by our meta-analytic dataset involving survival rates after treatment for critical leg ischemia, we develop and apply a new multivariate model for the meta-analysis of study level survival data at multiple times. Our data set involves 50 studies that provide mortality rates at up to seven time points, which we model simultaneously, and we compare the results to those obtained from standard methodologies. Our method uses exact binomial within-study distributions and enforces the constraints that both the study specific and the overall mortality rates must not decrease over time. We directly model the probabilities of mortality at each time point, which are the quantities of primary clinical interest. We also present I(2) statistics that quantify the impact of the between-study heterogeneity, which is very considerable in our data set.

  10. Spatio-Temporal Pattern and Socio-Economic Factors of Bacillary Dysentery at County Level in Sichuan Province, China.

    PubMed

    Ma, Yue; Zhang, Tao; Liu, Lei; Lv, Qiang; Yin, Fei

    2015-10-15

    Bacillary dysentery (BD) remains a big public health problem in China. Effective spatio-temporal monitoring of BD incidence is important for successful implementation of control and prevention measures. This study aimed to examine the spatio-temporal pattern of BD and analyze socio-economic factors that may affect BD incidence in Sichuan province, China. Firstly, we used space-time scan statistic to detect the high risk spatio-temporal clusters in each year. Then, bivariate spatial correlation and Bayesian spatio-temporal model were utilized to examine the associations between the socio-economic factors and BD incidence. Spatio-temporal clusters of BD were mainly located in the northern-southern belt of the midwest area of Sichuan province. The proportion of primary industry, the proportion of rural population and the rates of BD incidence show statistically significant positive correlation. The proportion of secondary industry, proportion of tertiary Industry, number of beds in hospitals per thousand persons, medical and technical personnel per thousand persons, per capital GDP and the rate of BD incidence show statistically significant negative correlation. The best fitting spatio-temporal model showed that medical and technical personnel per thousand persons and per capital GDP were significantly negative related to the risk of BD.

  11. Identification of the source of elevated hepatocyte growth factor levels in multiple myeloma patients

    PubMed Central

    2014-01-01

    Background Hepatocyte growth factor (HGF) is a pleiotropic cytokine which can lead to cancer cell proliferation, migration and metastasis. In multiple myeloma (MM) patients it is an abundant component of the bone marrow. HGF levels are elevated in 50% of patients and associated with poor prognosis. Here we aim to investigate its source in myeloma. Methods HGF mRNA levels in bone marrow core biopsies from healthy individuals and myeloma patients were quantified by real-time PCR. HGF gene expression profiling in CD138+ cells isolated from bone marrow aspirates of healthy individuals and MM patients was performed by microarray analysis. HGF protein concentrations present in peripheral blood of MM patients were measured by enzyme-linked immunosorbent assay (ELISA). Cytogenetic status of CD138+ cells was determined by fluorescence in situ hybridization (FISH) and DNA sequencing of the HGF gene promoter. HGF secretion in co-cultures of human myeloma cell lines and bone marrow stromal cells was measured by ELISA. Results HGF gene expression profiling in both bone marrow core biopsies and CD138+ cells showed elevated HGF mRNA levels in myeloma patients. HGF mRNA levels in biopsies and in myeloma cells correlated. Quantification of HGF protein levels in serum also correlated with HGF mRNA levels in CD138+ cells from corresponding patients. Cytogenetic analysis showed myeloma cell clones with HGF copy numbers between 1 and 3 copies. There was no correlation between HGF copy number and HGF mRNA levels. Co-cultivation of the human myeloma cell lines ANBL-6 and JJN3 with bone marrow stromal cells or the HS-5 cell line resulted in a significant increase in secreted HGF. Conclusions We here show that in myeloma patients HGF is primarily produced by malignant plasma cells, and that HGF production by these cells might be supported by the bone marrow microenvironment. Considering the fact that elevated HGF serum and plasma levels predict poor prognosis, these findings are of

  12. Temporal variation (seasonal and interannual) of vegetation indices of maize and soybeans across multiple years in central Iowa

    NASA Astrophysics Data System (ADS)

    Prueger, J. H.; Hatfield, J. L.

    2015-09-01

    Remotely sensed reflectance parameters from corn and soybean surfaces can be correlated to crop production. Surface reflectance of a typical Upper Midwest corn /soybean region in central Iowa across multiple years reveal subtle dynamics in vegetative surface response to a continually varying climate. From 2006 through 2014 remotely sensed data have been acquired over production fields of corn and soybeans in central IA, U.S.A. with the fields alternating between corn and soybeans. The data have been acquired using ground-based radiometers with 16 wavebands covering the visible, near infrared, shortwave infrared wavebands and combined into a series of vegetative indices. These data were collected on clear days with the goal of collecting data at a minimum of once per week from prior to planting until after fall tillage operations. Within each field, five sites were established and sampled during the year to reduce spatial variation and allow for an assessment of changes in the vegetative indices throughout the growing season. Ancillary data collected for each crop included the phenological stage at each sampling date along with biomass sampled at the onset of the reproductive stage and at physiological maturity. Evaluation of the vegetative indices for the different years revealed that patterns were related to weather effects on corn and soybean growth. Remote sensing provides a method to evaluate changes within and among growing seasons to assess crop growth and development as affected by differences in weather variability.

  13. Low Serum Urate Levels Are Associated to Female Gender in Multiple Sclerosis Patients

    PubMed Central

    Zoccolella, Stefano; Tortorella, Carla; Iaffaldano, Pietro; Direnzo, Vita; D’Onghia, Mariangela; Luciannatelli, Elena; Paolicelli, Damiano; Livrea, Paolo; Trojano, Maria

    2012-01-01

    Background Urate is a natural antioxidant and may prevent CNS tissue damage and the clinical manifestations of experimental autoimmune encephalitis. Results from clinical studies are conflicting and the contribution of urate to the pathogenesis of Multiple Sclerosis (MS) remains uncertain. Objective To evaluate serum urate levels in MS patients and their relationships with clinical, demographic and MRI variables. Methods Levels of non-fasting serum uric acid and creatinine were determined by an automated enzymatic assay and glomerular filtration rate was assessed in 245 MS patients, in 252 age/sex-matched neurological controls (NC) and in 59 Healthy controls (HC). Results Median serum urate levels did not differ between MS patients (3.8 mg/dL), HC (4.0 mg/dl) and NC (4.0 mg/dL). Serum urate levels were lower in females than in males in all groups (p = <0.0001). In female-MS, serum urate levels (3.2 mg/dL) were lower compared to those in female HC (3.8; p = 0.01) and NC (3.5 mg/dL; p = 0.02), whereas in male-MS they(4.8 mg/dL) did not differ from those in male HC (4.5 mg/dl) and NC (4.8 mg/dL). Urate concentrations trended to be lower in Clinically isolated syndromes suggestive of MS (3.7 mg/dL) and in relapsing MS (3.7 mg/dL), compared to patients with progressive MS (4.4 mg/dL; p = 0.06), and in patients with an annual relapse rate (ARR) >2 (3.3 mg/dL) than in those with an ARR ≤2: 3.9 mg/dL; p = 0.05). Significant lower serum urate levels were found in females than in males in all clinical MS subtypes (p<0.01), separately evaluated. Female sex (beta: −0.53; p<0.00001) was the most significant determinant of serum urate concentrations in MS patients on multivariate regression analysis. Conclusions Our findings suggest that low urate levels could be of significance in predominantly inflammatory phases of MS even at the early stage and mainly in females. PMID:22848387

  14. Higher minor hemoglobin A2 levels in multiple sclerosis patients correlate with lesser disease severity

    PubMed Central

    Ozcan, Muhammed Emin; Ince, Bahri; Karadeli, Hasan Huseyin; Gedikbasi, Asuman; Asil, Talip; Altinoz, Meric A

    2016-01-01

    Objective To define whether minor adult hemoglobin A2 (HbA2, α2δ2) exerts any protective activity in multiple sclerosis (MS). Methods HbA2 levels were measured in 146 MS patients with high performance liquid chromatography and association with MS Severity Scores (MSSS) were determined. HbA2 associations with blood count parameters were also studied using blood counts evaluated on the same day of high performance liquid chromatography sampling. Routine biochemical parameters were also determined to rule out elusively influential factors, such as anemia and thyroid disorders. Results HbA2 levels negatively correlated with MSSS (Spearman correlation, R: −0.186, P=0.025). Exclusion of confounding factors with a generalized linear model revealed an even stronger negative correlation between HbA2 and MSSS (P<0.001). HbA2 positively correlated with red blood cells (RBCs) (R=0.350, P<0.001) and in turn, RBCs negatively correlated with MSSS (R=−0.180, P=0.031). Average HbA2 levels were highest among patients treated with interferon β1a. Conclusion RBC fragility is increased in MS, and recent data suggest that circulating free Hb contributes to neural injury in MS. HbA2 and its oxidative denaturation product hemichrome A2 enhance RBC membrane stability to a greater extent than do major HbA or hemichrome A. Reductions in ischemic cerebrovascular vascular events are reported in β-thalassemia carriers and HbA2 levels are considerably higher in this population. Episodic declines of cerebral blood flow were shown in bipolar disorder, and we have recently shown a protective role of HbA2 against postpartum episodes in females with bipolar disorder. HbA2’s erythroprotective functions may reduce free Hb and long-term neural injury in MS. PMID:27578976

  15. Farm-level feasibility of bioenergy depends on variations across multiple sectors

    NASA Astrophysics Data System (ADS)

    Myhre, Mitchell; Barford, Carol

    2013-03-01

    The potential supply of bioenergy from farm-grown biomass is uncertain due to several poorly understood or volatile factors, including land availability, yield variability, and energy prices. Although biomass production for liquid fuel has received more attention, here we present a case study of biomass production for renewable heat and power in the state of Wisconsin (US), where heating constitutes at least 30% of total energy demand. Using three bioenergy systems (50 kW, 8.8 MW and 50 MW) and Wisconsin farm-level data, we determined the net farm income effect of producing switchgrass (Panicum virgatum) as a feedstock, either for on-farm use (50 kW system) or for sale to an off-farm energy system operator (8.8 and 50 MW systems). In southern counties, where switchgrass yields approach 10 Mg ha-1 yr-1, the main determinants of economic feasibility were the available land area per farm, the ability to utilize bioheat, and opportunity cost assumptions. Switchgrass yield temporal variability was less important. For the state median farm size and switchgrass yield, at least 25% (50 kW system) or 50% (8.8 MW system) bioheat utilization was required to economically offset propane or natural gas heat, respectively, and purchased electricity. Offsetting electricity only (50 MW system) did not generate enough revenue to meet switchgrass production expenses. Although the opportunity cost of small-scale (50 kW) on-farm bioenergy generation was higher, it also held greater opportunity for increasing farm net income, especially by replacing propane-based heat.

  16. The nuclear receptor LXR modulates interleukin-18 levels in macrophages through multiple mechanisms

    PubMed Central

    Pourcet, Benoit; Gage, Matthew C.; León, Theresa E.; Waddington, Kirsty E.; Pello, Oscar M.; Steffensen, Knut R.; Castrillo, Antonio; Valledor, Annabel F.; Pineda-Torra, Inés

    2016-01-01

    IL-18 is a member of the IL-1 family involved in innate immunity and inflammation. Deregulated levels of IL-18 are involved in the pathogenesis of multiple disorders including inflammatory and metabolic diseases, yet relatively little is known regarding its regulation. Liver X receptors or LXRs are key modulators of macrophage cholesterol homeostasis and immune responses. Here we show that LXR ligands negatively regulate LPS-induced mRNA and protein expression of IL-18 in bone marrow-derived macrophages. Consistent with this being an LXR-mediated process, inhibition is abolished in the presence of a specific LXR antagonist and in LXR-deficient macrophages. Additionally, IL-18 processing of its precursor inactive form to its bioactive state is inhibited by LXR through negative regulation of both pro-caspase 1 expression and activation. Finally, LXR ligands further modulate IL-18 levels by inducing the expression of IL-18BP, a potent endogenous inhibitor of IL-18. This regulation occurs via the transcription factor IRF8, thus identifying IL-18BP as a novel LXR and IRF8 target gene. In conclusion, LXR activation inhibits IL-18 production through regulation of its transcription and maturation into an active pro-inflammatory cytokine. This novel regulation of IL-18 by LXR could be applied to modulate the severity of IL-18 driven metabolic and inflammatory disorders. PMID:27149934

  17. Spatial and Temporal Distribution of Multiple Cropping Indices in the North China Plain Using a Long Remote Sensing Data Time Series

    PubMed Central

    Zhao, Yan; Bai, Linyan; Feng, Jianzhong; Lin, Xiaosong; Wang, Li; Xu, Lijun; Ran, Qiyun; Wang, Kui

    2016-01-01

    Multiple cropping provides China with a very important system of intensive cultivation, and can effectively enhance the efficiency of farmland use while improving regional food production and security. A multiple cropping index (MCI), which represents the intensity of multiple cropping and reflects the effects of climate change on agricultural production and cropping systems, often serves as a useful parameter. Therefore, monitoring the dynamic changes in the MCI of farmland over a large area using remote sensing data is essential. For this purpose, nearly 30 years of MCIs related to dry land in the North China Plain (NCP) were efficiently extracted from remotely sensed leaf area index (LAI) data from the Global LAnd Surface Satellite (GLASS). Next, the characteristics of the spatial-temporal change in MCI were analyzed. First, 2162 typical arable sample sites were selected based on a gridded spatial sampling strategy, and then the LAI information was extracted from the samples. Second, the Savizky-Golay filter was used to smooth the LAI time-series data of the samples, and then the MCIs of the samples were obtained using a second-order difference algorithm. Finally, the geo-statistical Kriging method was employed to map the spatial distribution of the MCIs and to obtain a time-series dataset of the MCIs of dry land over the NCP. The results showed that all of the MCIs in the NCP showed an increasing trend over the entire study period and increased most rapidly from 1982 to 2002. Spatially, MCIs decreased from south to north; also, high MCIs were mainly concentrated in the relatively flat areas. In addition, the partial spatial changes of MCIs had clear geographical characteristics, with the largest change in Henan Province. PMID:27104536

  18. Spatial and Temporal Distribution of Multiple Cropping Indices in the North China Plain Using a Long Remote Sensing Data Time Series.

    PubMed

    Zhao, Yan; Bai, Linyan; Feng, Jianzhong; Lin, Xiaosong; Wang, Li; Xu, Lijun; Ran, Qiyun; Wang, Kui

    2016-04-19

    Multiple cropping provides China with a very important system of intensive cultivation, and can effectively enhance the efficiency of farmland use while improving regional food production and security. A multiple cropping index (MCI), which represents the intensity of multiple cropping and reflects the effects of climate change on agricultural production and cropping systems, often serves as a useful parameter. Therefore, monitoring the dynamic changes in the MCI of farmland over a large area using remote sensing data is essential. For this purpose, nearly 30 years of MCIs related to dry land in the North China Plain (NCP) were efficiently extracted from remotely sensed leaf area index (LAI) data from the Global LAnd Surface Satellite (GLASS). Next, the characteristics of the spatial-temporal change in MCI were analyzed. First, 2162 typical arable sample sites were selected based on a gridded spatial sampling strategy, and then the LAI information was extracted from the samples. Second, the Savizky-Golay filter was used to smooth the LAI time-series data of the samples, and then the MCIs of the samples were obtained using a second-order difference algorithm. Finally, the geo-statistical Kriging method was employed to map the spatial distribution of the MCIs and to obtain a time-series dataset of the MCIs of dry land over the NCP. The results showed that all of the MCIs in the NCP showed an increasing trend over the entire study period and increased most rapidly from 1982 to 2002. Spatially, MCIs decreased from south to north; also, high MCIs were mainly concentrated in the relatively flat areas. In addition, the partial spatial changes of MCIs had clear geographical characteristics, with the largest change in Henan Province.

  19. CO2 and nutrient-driven changes across multiple levels of organization in Zostera noltii ecosystems

    NASA Astrophysics Data System (ADS)

    Martínez-Crego, B.; Olivé, I.; Santos, R.

    2014-12-01

    Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low- and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and

  20. Inter-Annotator Reliability of Medical Events, Coreferences and Temporal Relations in Clinical Narratives by Annotators with Varying Levels of Clinical Expertise

    PubMed Central

    Raghavan, Preethi; Fosler-Lussier, Eric; Lai, Albert M.

    2012-01-01

    The manual annotation of clinical narratives is an important step for training and validating the performance of automated systems that utilize these clinical narratives. We build an annotation specification to capture medical events, and coreferences and temporal relations between medical events in clinical text. Unfortunately, the process of clinical data annotation is both time consuming and costly. Many annotation efforts have used physicians to annotate the data. We investigate using annotators that are current students or graduates from diverse clinical backgrounds with varying levels of clinical experience. In spite of this diversity, the annotation agreement across our team of annotators is high; the average inter-annotator kappa statistic for medical events, coreferences, temporal relations, and medical event concept unique identifiers was 0.843, 0.859, 0.833, and 0.806, respectively. We describe methods towards leveraging the annotations to support temporal reasoning with medical events. PMID:23304416

  1. Molecular evolution of multiple-level control of heme biosynthesis pathway in animal kingdom.

    PubMed

    Tzou, Wen-Shyong; Chu, Ying; Lin, Tzung-Yi; Hu, Chin-Hwa; Pai, Tun-Wen; Liu, Hsin-Fu; Lin, Han-Jia; Cases, Ildeofonso; Rojas, Ana; Sanchez, Mayka; You, Zong-Ye; Hsu, Ming-Wei

    2014-01-01

    Adaptation of enzymes in a metabolic pathway can occur not only through changes in amino acid sequences but also through variations in transcriptional activation, mRNA splicing and mRNA translation. The heme biosynthesis pathway, a linear pathway comprised of eight consecutive enzymes in animals, provides researchers with ample information for multiple types of evolutionary analyses performed with respect to the position of each enzyme in the pathway. Through bioinformatics analysis, we found that the protein-coding sequences of all enzymes in this pathway are under strong purifying selection, from cnidarians to mammals. However, loose evolutionary constraints are observed for enzymes in which self-catalysis occurs. Through comparative genomics, we found that in animals, the first intron of the enzyme-encoding genes has been co-opted for transcriptional activation of the genes in this pathway. Organisms sense the cellular content of iron, and through iron-responsive elements in the 5' untranslated regions of mRNAs and the intron-exon boundary regions of pathway genes, translational inhibition and exon choice in enzymes may be enabled, respectively. Pathway product (heme)-mediated negative feedback control can affect the transport of pathway enzymes into the mitochondria as well as the ubiquitin-mediated stability of enzymes. Remarkably, the positions of these controls on pathway activity are not ubiquitous but are biased towards the enzymes in the upstream portion of the pathway. We revealed that multiple-level controls on the activity of the heme biosynthesis pathway depend on the linear depth of the enzymes in the pathway, indicating a new strategy for discovering the molecular constraints that shape the evolution of a metabolic pathway.

  2. Correlation of Fatigue with Depression, Disability Level and Quality of Life in Patients with Multiple Sclerosis

    PubMed Central

    KAYA AYGÜNOĞLU, Selma; ÇELEBİ, Arif; VARDAR, Nilgün; GÜRSOY, Esra

    2015-01-01

    Introduction Fatigue is a subjective and non-specific symptom; therefore, evaluation of fatigue is quite difficult. Fatigue has been reported in 75%–87% of patients with multiple sclerosis (MS) and two-thirds of these patients indicated fatigue as one of the worst three common symptoms that they experienced. This study was conducted to measure the intensity, frequency and the characteristics of fatigue in patients with MS. Moreover, the effect of fatigue on the quality of life and its association with depression and disability were evaluated. Methods One hundred and twenty patients with multiple sclerosis (84 women and 36 men) were included in our study. The patients’ sociodemographic characteristics and their experiences on symptoms of fatigue were questioned. Presence and degree of fatigue were assessed using the fatigue severity scale (FSS). Disability status was detected with expanded disability status scale (EDSS). The Multiple Sclerosis Quality of Life (MSQoL-54) survey was conducted to evaluate the quality of life of patients and Beck Depression Inventory (BDI) was used to determine the current depression status. Patients were grouped into fatigue and non-fatigue groups based on FSS. Both groups were compared according to their age, sex, MS clinical types, course of the disease and scores of EDSS, BDI and MSQoL-54. Results Seventy percent of patients reported fatigue and 38% of these patients defined fatigue as their most disabling symptom. There was no correlation of fatigue with age, sex and disease duration. The correlation of fatigue and educational level was negative and weak (p<.05, r=−.214) and the correlation between fatigue and MS clinical types were significant but weak (p<.01, r=.228). Patients with fatigue had higher EDSS and BDI scores. In addition, FSS scores were found to be statistically meaningful and positively correlated with both EDSS and BDI scores (r=.404, r=.476, p<.01). Furthermore, our findings revealed that the quality of life

  3. Cognitive and cortical plasticity deficits correlate with altered amyloid-β CSF levels in multiple sclerosis.

    PubMed

    Mori, Francesco; Rossi, Silvia; Sancesario, Giulia; Codecà, Claudia; Mataluni, Giorgia; Monteleone, Fabrizia; Buttari, Fabio; Kusayanagi, Hajime; Castelli, Maura; Motta, Caterina; Studer, Valeria; Bernardi, Giorgio; Koch, Giacomo; Bernardini, Sergio; Centonze, Diego

    2011-02-01

    Cognitive dysfunction is of frequent observation in multiple sclerosis (MS). It is associated with gray matter pathology, brain atrophy, and altered connectivity, and recent evidence showed that acute inflammation can exacerbate mental deficits independently of the primary functional system involved. In this study, we measured cerebrospinal fluid (CSF) levels of amyloid-β(1-42) and τ protein in MS and in clinically isolated syndrome patients, as both proteins have been associated with cognitive decline in Alzheimer's disease (AD). In AD, amyloid-β(1-42) accumulates in the brain as insoluble extracellular plaques, possibly explaining why soluble amyloid-β(1-42) is reduced in the CSF of these patients. In our sample of MS patients, amyloid-β(1-42) levels were significantly lower in patients cognitively impaired (CI) and were inversely correlated with the number of Gadolinium-enhancing (Gd+) lesions at the magnetic resonance imaging (MRI). Positive correlations between amyloid-β(1-42) levels and measures of attention and concentration were also found. Furthermore, abnormal neuroplasticity of the cerebral cortex, explored with θ burst stimulation (TBS), was observed in CI patients, and a positive correlation was found between amyloid-β(1-42) CSF contents and the magnitude of long-term potentiation-like effects induced by TBS. No correlation was conversely found between τ protein concentrations and MRI findings, cognitive parameters, and TBS effects in these patients. Together, our results indicate that in MS, central inflammation is able to alter amyloid-β metabolism by reducing its concentration in the CSF and leading to impairment of synaptic plasticity and cognitive function.

  4. Development of temporally refined land-use regression models predicting daily household-level air pollution in a panel study of lung function among asthmatic children.

    PubMed

    Johnson, Markey; Macneill, Morgan; Grgicak-Mannion, Alice; Nethery, Elizabeth; Xu, Xiaohong; Dales, Robert; Rasmussen, Pat; Wheeler, Amanda

    2013-01-01

    Regulatory monitoring data and land-use regression (LUR) models have been widely used for estimating individual exposure to ambient air pollution in epidemiologic studies. However, LUR models lack fine-scale temporal resolution for predicting acute exposure and regulatory monitoring provides daily concentrations, but fails to capture spatial variability within urban areas. This study coupled LUR models with continuous regulatory monitoring to predict daily ambient nitrogen dioxide (NO(2)) and particulate matter (PM(2.5)) at 50 homes in Windsor, Ontario. We compared predicted versus measured daily outdoor concentrations for 5 days in winter and 5 days in summer at each home. We also examined the implications of using modeled versus measured daily pollutant concentrations to predict daily lung function among asthmatic children living in those homes. Mixed effect analysis suggested that temporally refined LUR models explained a greater proportion of the spatial and temporal variance in daily household-level outdoor NO(2) measurements compared with daily concentrations based on regulatory monitoring. Temporally refined LUR models captured 40% (summer) and 10% (winter) more of the spatial variance compared with regulatory monitoring data. Ambient PM(2.5) showed little spatial variation; therefore, daily PM(2.5) models were similar to regulatory monitoring data in the proportion of variance explained. Furthermore, effect estimates for forced expiratory volume in 1 s (FEV(1)) and peak expiratory flow (PEF) based on modeled pollutant concentrations were consistent with effects based on household-level measurements for NO(2) and PM(2.5). These results suggest that LUR modeling can be combined with continuous regulatory monitoring data to predict daily household-level exposure to ambient air pollution. Temporally refined LUR models provided a modest improvement in estimating daily household-level NO(2) compared with regulatory monitoring data alone, suggesting that this

  5. Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina.

    PubMed

    Frate, Ludovico; Acosta, Alicia T R; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

    2015-01-01

    The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979-2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (Pf) and structural connectivity (Pff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting Pf vs. Pff mean values and were compared across spatial extents. The distributions of Pf across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of Pf's variability along with the increment of the mean slope of the Pf 's scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and sustainable

  6. On the potentials of multiple climate variables in assessing the spatio-temporal characteristics of hydrological droughts over the Volta Basin.

    PubMed

    Ndehedehe, Christopher E; Awange, Joseph L; Corner, Robert J; Kuhn, Michael; Okwuashi, Onuwa

    2016-07-01

    Multiple drought episodes over the Volta basin in recent reports may lead to food insecurity and loss of revenue. However, drought studies over the Volta basin are rather generalised and largely undocumented due to sparse ground observations and unsuitable framework to determine their space-time occurrence. In this study, we examined the utility of standardised indicators (standardised precipitation index (SPI), standardised runoff index (SRI), standardised soil moisture index (SSI), and multivariate standardised drought index (MSDI)) and Gravity Recovery and Climate Experiment (GRACE) derived terrestrial water storage to assess hydrological drought characteristics over the basin. In order to determine the space-time patterns of hydrological drought in the basin, Independent Component Analysis (ICA), a higher order statistical technique was employed. The results show that SPI and SRI exhibit inconsistent behaviour in observed wet years presupposing a non-linear relationship that reflects the slow response of river discharge to precipitation especially after a previous extreme dry period. While the SPI and SSI show a linear relationship with a correlation of 0.63, the correlation between the MSDIs derived from combining precipitation/river discharge and precipitation/soil moisture indicates a significant value of 0.70 and shows an improved skill in hydrological drought monitoring over the Volta basin during the study period. The ICA-derived spatio-temporal hydrological drought patterns show Burkina Faso and the Lake Volta areas as predominantly drought zones. Further, the statistically significant negative correlations of pacific decadal oscillations (0.39 and 0.25) with temporal evolutions of drought in Burkina Faso and Ghana suggest the possible influence of low frequency large scale oscillations in the observed wet and dry regimes over the basin. Finally, our approach in drought assessment over the Volta basin contributes to a broad framework for hydrological

  7. Spontaneous switching among multiple spatio-temporal patterns in three-oscillator systems constructed with oscillatory cells of true slime mold

    NASA Astrophysics Data System (ADS)

    Takamatsu, Atsuko

    2006-11-01

    Three-oscillator systems with plasmodia of true slime mold, Physarum polycephalum, which is an oscillatory amoeba-like unicellular organism, were experimentally constructed and their spatio-temporal patterns were investigated. Three typical spatio-temporal patterns were found: rotation ( R), partial in-phase ( PI), and partial anti-phase with double frequency ( PA). In pattern R, phase differences between adjacent oscillators were almost 120 ∘. In pattern PI, two oscillators were in-phase and the third oscillator showed anti-phase against the two oscillators. In pattern PA, two oscillators showed anti-phase and the third oscillator showed frequency doubling oscillation with small amplitude. Actually each pattern is not perfectly stable but quasi-stable. Interestingly, the system shows spontaneous switching among the multiple quasi-stable patterns. Statistical analyses revealed a characteristic in the residence time of each pattern: the histograms seem to have Gamma-like distribution form but with a sharp peak and a tail on the side of long period. That suggests the attractor of this system has complex structure composed of at least three types of sub-attractors: a “Gamma attractor”-involved with several Poisson processes, a “deterministic attractor”-the residence time is deterministic, and a “stable attractor”-each pattern is stable. When the coupling strength was small, only the Gamma attractor was observed and switching behavior among patterns R, PI, and PA almost always via an asynchronous pattern named O. A conjecture is as follows: Internal/external noise exposes each pattern of R, PI, and PA coexisting around bifurcation points: That is observed as the Gamma attractor. As coupling strength increases, the deterministic attractor appears then followed by the stable attractor, always accompanied with the Gamma attractor. Switching behavior could be caused by regular existence of the Gamma attractor.

  8. Cholera in Cameroon, 2000-2012: Spatial and Temporal Analysis at the Operational (Health District) and Sub Climate Levels

    PubMed Central

    Liang, Song; Kracalik, Ian T.; Morris, Lillian; Blackburn, Jason K.; Mbam, Leonard M.; Ba Pouth, Simon Franky Baonga; Teboh, Andrew; Yang, Yang; Arabi, Mouhaman; Sugimoto, Jonathan D.; Morris, John Glenn

    2016-01-01

    Introduction Recurrent cholera outbreaks have been reported in Cameroon since 1971. However, case fatality ratios remain high, and we do not have an optimal understanding of the epidemiology of the disease, due in part to the diversity of Cameroon’s climate subzones and a lack of comprehensive data at the health district level. Methods/Findings A unique health district level dataset of reported cholera case numbers and related deaths from 2000–2012, obtained from the Ministry of Public Health of Cameroon and World Health Organization (WHO) country office, served as the basis for the analysis. During this time period, 43,474 cholera cases were reported: 1748 were fatal (mean annual case fatality ratio of 7.9%), with an attack rate of 17.9 reported cases per 100,000 inhabitants per year. Outbreaks occurred in three waves during the 13-year time period, with the highest case fatality ratios at the beginning of each wave. Seasonal patterns of illness differed strikingly between climate subzones (Sudano-Sahelian, Tropical Humid, Guinea Equatorial, and Equatorial Monsoon). In the northern Sudano-Sahelian subzone, highest number of cases tended to occur during the rainy season (July-September). The southern Equatorial Monsoon subzone reported cases year-round, with the lowest numbers during peak rainfall (July-September). A spatial clustering analysis identified multiple clusters of high incidence health districts during 2010 and 2011, which were the 2 years with the highest annual attack rates. A spatiotemporal autoregressive Poisson regression model fit to the 2010–2011 data identified significant associations between the risk of transmission and several factors, including the presence of major waterbody or highway, as well as the average daily maximum temperature and the precipitation levels over the preceding two weeks. The direction and/or magnitude of these associations differed between climate subzones, which, in turn, differed from national estimates that

  9. The Periaqueductal Gray Orchestrates Sensory and Motor Circuits at Multiple Levels of the Neuraxis

    PubMed Central

    Koutsikou, Stella; Watson, Thomas C.; Crook, Jonathan J.; Leith, J. Lianne; Lawrenson, Charlotte L.; Lumb, Bridget M.

    2015-01-01

    The periaqueductal gray (PAG) coordinates behaviors essential to survival, including striking changes in movement and posture (e.g., escape behaviors in response to noxious stimuli vs freezing in response to fear-evoking stimuli). However, the neural circuits underlying the expression of these behaviors remain poorly understood. We demonstrate in vivo in rats that activation of the ventrolateral PAG (vlPAG) affects motor systems at multiple levels of the neuraxis through the following: (1) differential control of spinal neurons that forward sensory information to the cerebellum via spino-olivo-cerebellar pathways (nociceptive signals are reduced while proprioceptive signals are enhanced); (2) alterations in cerebellar nuclear output as revealed by changes in expression of Fos-like immunoreactivity; and (3) regulation of spinal reflex circuits, as shown by an increase in α-motoneuron excitability. The capacity to coordinate sensory and motor functions is demonstrated in awake, behaving rats, in which natural activation of the vlPAG in fear-conditioned animals reduced transmission in spino-olivo-cerebellar pathways during periods of freezing that were associated with increased muscle tone and thus motor outflow. The increase in spinal motor reflex excitability and reduction in transmission of ascending sensory signals via spino-olivo-cerebellar pathways occurred simultaneously. We suggest that the interactions revealed in the present study between the vlPAG and sensorimotor circuits could form the neural substrate for survival behaviors associated with vlPAG activation. SIGNIFICANCE STATEMENT Neural circuits that coordinate survival behaviors remain poorly understood. We demonstrate in rats that the periaqueductal gray (PAG) affects motor systems at the following multiple levels of the neuraxis: (1) through altering transmission in spino-olivary pathways that forward sensory signals to the cerebellum, reducing and enhancing transmission of nociceptive and

  10. Spatially Oriented, Temporally Sequential Smooth Muscle Cell-Endothelial Progenitor Cell Bi-Level Cell Sheet Neovascularizes Ischemic Myocardium

    PubMed Central

    Shudo, Yasuhiro; Cohen, Jeffrey E.; MacArthur, John W.; Atluri, Pavan; Hsiao, Philip F.; Yang, Elaine C.; Fairman, Alexander S.; Trubelja, Alen; Patel, Jay; Miyagawa, Shigeru; Sawa, Yoshiki; Woo, Y. Joseph

    2014-01-01

    Background Endothelial progenitor cells (EPCs) possess robust therapeutic angiogenic potential, yet may be limited in the capacity to develop into fully mature vasculature. This problem might be exacerbated by the absence of a neovascular foundation, namely pericytes, with simple EPC injection. We hypothesized that coculturing EPCs with smooth muscle cells (SMCs), components of the surrounding vascular wall, in a cell sheet will mimic the native spatial orientation and interaction between EPCs and SMCs to create a supratherapeutic angiogenic construct in a model of ischemic cardiomyopathy. Methods and Results Primary EPCs and SMCs were isolated from Wistar rats. Confluent SMCs topped with confluent EPCs were spontaneously detached from the Upcell dish to create an SMC-EPC bi-level cell sheet. A rodent ischemic cardiomyopathy model was created by ligating the left anterior descending coronary artery. Rats were then immediately divided into 3 groups: cell-sheet transplantation (n=14), cell injection (n=12), and no treatment (n=13). Cocultured EPCs and SMCs stimulated an abundant release of multiple cytokines in vitro. Increased capillary density and improved blood perfusion in the borderzone elucidated the significant in vivo angiogenic potential of this technology. Most interestingly, however, cell fate–tracking experiments demonstrated that the cell-sheet EPCs and SMCs directly migrated into the myocardium and differentiated into elements of newly formed functional vasculature. The robust angiogenic effect of this cell sheet translated to enhanced ventricular function as demonstrated by echocardiography. Conclusions Spatially arranged EPC-SMC bi-level cell-sheet technology facilitated the natural interaction between EPCs and SMCs, thereby creating structurally mature, functional microvasculature in a rodent ischemic cardiomyopathy model, leading to improved myocardial function. PMID:24030422

  11. Comparative Metagenomics Reveal Phylum Level Temporal and Spatial Changes in Mycobiome of Belowground Parts of Crocus sativus

    PubMed Central

    Ambardar, Sheetal; Singh, Heikham Russiachand; Gowda, Malali; Vakhlu, Jyoti

    2016-01-01

    Plant-fungal associations have been explored by routine cultivation based approaches and cultivation based approaches cannot catalogue more than 5% of fungal diversity associated with any niche. In the present study, an attempt has been made to catalogue fungal diversity associated with belowground parts i.e. rhizosphere and cormosphere, of Crocus sativus (an economically important herb) during two growth stages, using cultivation independent ITS gene targeted approach, taking bulk soil as reference. The 454 pyrosequencing sequence data analysis suggests that the fungal diversity was niche and growth stage specific. Fungi diversity, in the present case, was not only different between the two organs (roots and corm) but the dominance pattern varies between the cormosphere during two growth stages. Zygomycota was dominant fungal phylum in the rhizosphere whereas Basidiomycota was dominant in cormosphere during flowering stage. However in cormosphere though Basidiomycota was dominant phylum during flowering stage but Zygomycota was dominant during dormant stage. Interestingly, in cormosphere, the phyla which was dominant at dormant stage was rare at flowering stage and vice-versa (Basidiomycota: Flowering = 93.2% Dormant = 0.05% and Zygomycota: Flowering = 0.8% Dormant = 99.7%). At genus level, Rhizopus was dominant in dormant stage but was rare in flowering stage (Rhizopus: Dormant = 99.7% Flowering = 0.55%). This dynamics is not followed by the bulk soil fungi which was dominated by Ascomycota during both stages under study. The genus Fusarium, whose species F. oxysporum causes corm rot in C. sativus, was present during both stages with slightly higher abundance in roots. Interestingly, the abundance of Rhizopus varied a great deal in two stages in cormosphere but the abundance of Fusarium was comparable in two growth stages (Bulk soil Flowering = 0.05%, Rhizosphere Flowering = 1.4%, Cormosphere Flowering = 0.06%, Bulk soil Dormant = 2.47% and cormosphere dormant

  12. Comparative Metagenomics Reveal Phylum Level Temporal and Spatial Changes in Mycobiome of Belowground Parts of Crocus sativus.

    PubMed

    Ambardar, Sheetal; Singh, Heikham Russiachand; Gowda, Malali; Vakhlu, Jyoti

    Plant-fungal associations have been explored by routine cultivation based approaches and cultivation based approaches cannot catalogue more than 5% of fungal diversity associated with any niche. In the present study, an attempt has been made to catalogue fungal diversity associated with belowground parts i.e. rhizosphere and cormosphere, of Crocus sativus (an economically important herb) during two growth stages, using cultivation independent ITS gene targeted approach, taking bulk soil as reference. The 454 pyrosequencing sequence data analysis suggests that the fungal diversity was niche and growth stage specific. Fungi diversity, in the present case, was not only different between the two organs (roots and corm) but the dominance pattern varies between the cormosphere during two growth stages. Zygomycota was dominant fungal phylum in the rhizosphere whereas Basidiomycota was dominant in cormosphere during flowering stage. However in cormosphere though Basidiomycota was dominant phylum during flowering stage but Zygomycota was dominant during dormant stage. Interestingly, in cormosphere, the phyla which was dominant at dormant stage was rare at flowering stage and vice-versa (Basidiomycota: Flowering = 93.2% Dormant = 0.05% and Zygomycota: Flowering = 0.8% Dormant = 99.7%). At genus level, Rhizopus was dominant in dormant stage but was rare in flowering stage (Rhizopus: Dormant = 99.7% Flowering = 0.55%). This dynamics is not followed by the bulk soil fungi which was dominated by Ascomycota during both stages under study. The genus Fusarium, whose species F. oxysporum causes corm rot in C. sativus, was present during both stages with slightly higher abundance in roots. Interestingly, the abundance of Rhizopus varied a great deal in two stages in cormosphere but the abundance of Fusarium was comparable in two growth stages (Bulk soil Flowering = 0.05%, Rhizosphere Flowering = 1.4%, Cormosphere Flowering = 0.06%, Bulk soil Dormant = 2.47% and cormosphere dormant

  13. Temporal variability of pyrethroid metabolite levels in bedtime, morning, and 24-hr urine samples for 50 adults in North Carolina

    EPA Science Inventory

    Pyrethroid insecticides are widely used to control insects in both agricultural and residential settings worldwide. Few data are available on the temporal variability of pyrethroid metabolites in the urine of non-occupationally exposed adults. In this work, we describe the study ...

  14. From stem cell to red cell: regulation of erythropoiesis at multiple levels by multiple proteins, RNAs, and chromatin modifications.

    PubMed

    Hattangadi, Shilpa M; Wong, Piu; Zhang, Lingbo; Flygare, Johan; Lodish, Harvey F

    2011-12-08

    This article reviews the regulation of production of RBCs at several levels. We focus on the regulated expansion of burst-forming unit-erythroid erythroid progenitors by glucocorticoids and other factors that occur during chronic anemia, inflammation, and other conditions of stress. We also highlight the rapid production of RBCs by the coordinated regulation of terminal proliferation and differentiation of committed erythroid colony-forming unit-erythroid progenitors by external signals, such as erythropoietin and adhesion to a fibronectin matrix. We discuss the complex intracellular networks of coordinated gene regulation by transcription factors, chromatin modifiers, and miRNAs that regulate the different stages of erythropoiesis.

  15. Mediators of Physical Activity on Neurocognitive Function: A Review at Multiple Levels of Analysis

    PubMed Central

    Stillman, Chelsea M.; Cohen, Jamie; Lehman, Morgan E.; Erickson, Kirk I.

    2016-01-01

    Physical activity (PA) is known to maintain and improve neurocognitive health. However, there is still a poor understanding of the mechanisms by which PA exerts its effects on the brain and cognition in humans. Many of the most widely discussed mechanisms of PA are molecular and cellular and arise from animal models. While information about basic cellular and molecular mechanisms is an important foundation from which to build our understanding of how PA promotes cognitive health in humans, there are other pathways that could play a role in this relationship. For example, PA-induced changes to cellular and molecular pathways likely initiate changes to macroscopic properties of the brain and/or to behavior that in turn influence cognition. The present review uses a more macroscopic lens to identify potential brain and behavioral/socioemotional mediators of the association between PA and cognitive function. We first summarize what is known regarding cellular and molecular mechanisms, and then devote the remainder of the review to discussing evidence for brain systems and behavioral/socioemotional pathways by which PA influences cognition. It is our hope that discussing mechanisms at multiple levels of analysis will stimulate the field to examine both brain and behavioral mediators. Doing so is important, as it could lead to a more complete characterization of the processes by which PA influences neurocognitive function, as well as a greater variety of targets for modifying neurocognitive function in clinical contexts. PMID:28018195

  16. Multiple Levels of Bilingual Language Control: Evidence from Language Intrusions in Reading Aloud

    PubMed Central

    Gollan, Tamar H.; Schotter, Elizabeth R.; Gomez, Joanne; Murillo, Mayra; Rayner, Keith

    2013-01-01

    Bilinguals rarely produce words in an unintended language. However, we induced such intrusion errors (e.g., saying el instead of he) in 32 Spanish-English bilinguals who read aloud language-selective and language-mixed paragraphs with English or Spanish word order. Bilinguals produced language intrusions almost exclusively in language-mixed paragraphs, and most often when attempting to produce dominant-language targets (accent-only errors also exhibited reversed language dominance effects). Most intrusion errors occurred for function word targets, especially when they did not match paragraph language word order. Eye movements showed that fixating a word in the non-target language increased intrusion errors only for function word targets. Together, these results imply multiple mechanisms of language control, including (a) inhibition of the dominant language at both lexical (Green, 1998) and sublexical processing levels, (b) special retrieval mechanisms for function words in mixed-language utterances (Myers-Scotton, 1993), and (c) attention’s role in monitoring target language for match with intended language. PMID:24367061

  17. Variants in ELL2 influencing immunoglobulin levels associate with multiple myeloma

    PubMed Central

    Swaminathan, Bhairavi; Thorleifsson, Guðmar; Jöud, Magnus; Ali, Mina; Johnsson, Ellinor; Ajore, Ram; Sulem, Patrick; Halvarsson, Britt-Marie; Eyjolfsson, Guðmundur; Haraldsdottir, Vilhelmina; Hultman, Christina; Ingelsson, Erik; Kristinsson, Sigurður Y.; Kähler, Anna K.; Lenhoff, Stig; Masson, Gisli; Mellqvist, Ulf-Henrik; Månsson, Robert; Nelander, Sven; Olafsson, Isleifur; Sigurðardottir, Olof; Steingrimsdóttir, Hlif; Vangsted, Annette; Vogel, Ulla; Waage, Anders; Nahi, Hareth; Gudbjartsson, Daniel F.; Rafnar, Thorunn; Turesson, Ingemar; Gullberg, Urban; Stefánsson, Kári; Hansson, Markus; Thorsteinsdóttir, Unnur; Nilsson, Björn

    2015-01-01

    Multiple myeloma (MM) is characterized by an uninhibited, clonal growth of plasma cells. While first-degree relatives of patients with MM show an increased risk of MM, the genetic basis of inherited MM susceptibility is incompletely understood. Here we report a genome-wide association study in the Nordic region identifying a novel MM risk locus at ELL2 (rs56219066T; odds ratio (OR)=1.25; P=9.6 × 10−10). This gene encodes a stoichiometrically limiting component of the super-elongation complex that drives secretory-specific immunoglobulin mRNA production and transcriptional regulation in plasma cells. We find that the MM risk allele harbours a Thr298Ala missense variant in an ELL2 domain required for transcription elongation. Consistent with a hypomorphic effect, we find that the MM risk allele also associates with reduced levels of immunoglobulin A (IgA) and G (IgG) in healthy subjects (P=8.6 × 10−9 and P=6.4 × 10−3, respectively) and, potentially, with an increased risk of bacterial meningitis (OR=1.30; P=0.0024). PMID:26007630

  18. Simplified analytical model for sound level prediction at shielded urban locations involving multiple diffraction and reflections.

    PubMed

    Wei, Weigang; Van Renterghem, Timothy; Botteldooren, Dick

    2015-11-01

    Accurate and efficient prediction of the sound field in shadow zones behind obstacles is a challenging task but essential to produce urban noise maps. A simplified method is presented to predict sound levels at shielded urban locations, including multi-edge diffraction over successive buildings and multiple reflections between parallel façades. The model is essentially based on Pierce's diffraction theory, where the Fresnel Integral is approximated by trigonometric functions for efficient evaluation, and parameterized for urban environments. The model has been validated for idealized urban configurations by comparing to the results of Pierce's theory and a full-wave numerical method. In case of multi-edge diffraction over buildings in absence of a source or receiver canyon, deviations from the full-wave simulations are smaller than 2 dB for the octave bands with central frequencies ranging from 125 to 1000 Hz. However, larger errors are made when receivers are close to the extension line from the diffraction edge closest to the receiver. In case of combining the simplified multi-edge diffraction model with an efficient approach for including the series of mirror sources and mirror receivers, based on the Hurwitz-Lerch transcendent, this same accuracy is obtained.

  19. Multiple-choice exams: an obstacle for higher-level thinking in introductory science classes.

    PubMed

    Stanger-Hall, Kathrin F

    2012-01-01

    Learning science requires higher-level (critical) thinking skills that need to be practiced in science classes. This study tested the effect of exam format on critical-thinking skills. Multiple-choice (MC) testing is common in introductory science courses, and students in these classes tend to associate memorization with MC questions and may not see the need to modify their study strategies for critical thinking, because the MC exam format has not changed. To test the effect of exam format, I used two sections of an introductory biology class. One section was assessed with exams in the traditional MC format, the other section was assessed with both MC and constructed-response (CR) questions. The mixed exam format was correlated with significantly more cognitively active study behaviors and a significantly better performance on the cumulative final exam (after accounting for grade point average and gender). There was also less gender-bias in the CR answers. This suggests that the MC-only exam format indeed hinders critical thinking in introductory science classes. Introducing CR questions encouraged students to learn more and to be better critical thinkers and reduced gender bias. However, student resistance increased as students adjusted their perceptions of their own critical-thinking abilities.

  20. Modeling Stochastic Kinetics of Molecular Machines at Multiple Levels: From Molecules to Modules

    PubMed Central

    Chowdhury, Debashish

    2013-01-01

    A molecular machine is either a single macromolecule or a macromolecular complex. In spite of the striking superficial similarities between these natural nanomachines and their man-made macroscopic counterparts, there are crucial differences. Molecular machines in a living cell operate stochastically in an isothermal environment far from thermodynamic equilibrium. In this mini-review we present a catalog of the molecular machines and an inventory of the essential toolbox for theoretically modeling these machines. The tool kits include 1), nonequilibrium statistical-physics techniques for modeling machines and machine-driven processes; and 2), statistical-inference methods for reverse engineering a functional machine from the empirical data. The cell is often likened to a microfactory in which the machineries are organized in modular fashion; each module consists of strongly coupled multiple machines, but different modules interact weakly with each other. This microfactory has its own automated supply chain and delivery system. Buoyed by the success achieved in modeling individual molecular machines, we advocate integration of these models in the near future to develop models of functional modules. A system-level description of the cell from the perspective of molecular machinery (the mechanome) is likely to emerge from further integrations that we envisage here. PMID:23746505

  1. Levels and Rates of Physical Activity in Older Adults with Multiple Sclerosis

    PubMed Central

    Klaren, Rachel E.; Sebastiao, Emerson; Chiu, Chung-Yi; Kinnett-Hopkins, Dominique; McAuley, Edward; Motl, Robert W.

    2016-01-01

    There is much evidence supporting the safety and benefits of physical activity in adults with multiple sclerosis (MS) and recent evidence of beneficial effects on physical function in older adults with MS. However, there is very little known about physical activity participation in older adults with conditions such as MS. This study compared levels of physical activity (i.e., sedentary behavior, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)) and rates of meeting public health guidelines for MVPA (i.e., ≥30 min/day) among young (i.e., ages 20-39 years), middle-aged (i.e., ages 40-59 years) and older adults (i.e., ages ≥60 years) with MS. The sample included 963 persons with MS who provided demographic and clinical information and wore an accelerometer for a 7-day period. The primary analysis involved a between-subjects ANOVA on accelerometer variables (i.e., accelerometer wear time; number of valid days; sedentary behavior in min/day; LPA in min/day; and MVPA in min/day). Collectively, our data indicated that older adults with MS engaged in less MVPA and more sedentary behavior than middle-aged and young adults with MS. Such results highlight the importance of developing physical activity interventions as an effective means for managing the progression and consequences of MS in older adults. PMID:27330842

  2. Modeling stochastic kinetics of molecular machines at multiple levels: from molecules to modules.

    PubMed

    Chowdhury, Debashish

    2013-06-04

    A molecular machine is either a single macromolecule or a macromolecular complex. In spite of the striking superficial similarities between these natural nanomachines and their man-made macroscopic counterparts, there are crucial differences. Molecular machines in a living cell operate stochastically in an isothermal environment far from thermodynamic equilibrium. In this mini-review we present a catalog of the molecular machines and an inventory of the essential toolbox for theoretically modeling these machines. The tool kits include 1), nonequilibrium statistical-physics techniques for modeling machines and machine-driven processes; and 2), statistical-inference methods for reverse engineering a functional machine from the empirical data. The cell is often likened to a microfactory in which the machineries are organized in modular fashion; each module consists of strongly coupled multiple machines, but different modules interact weakly with each other. This microfactory has its own automated supply chain and delivery system. Buoyed by the success achieved in modeling individual molecular machines, we advocate integration of these models in the near future to develop models of functional modules. A system-level description of the cell from the perspective of molecular machinery (the mechanome) is likely to emerge from further integrations that we envisage here.

  3. Population-level effects and recovery of aquatic invertebrates after multiple applications of an insecticide.

    PubMed

    Dohmen, G Peter; Preuss, Thomas G; Hamer, Mick; Galic, Nika; Strauss, Tido; van den Brink, Paul J; De Laender, Frederik; Bopp, Stephanie

    2016-01-01

    Standard risk assessment of plant protection products (PPP) combines "worst-case" exposure scenarios with effect thresholds using assessment (safety) factors to account for uncertainties. If needed, risks can be addressed applying more realistic conditions at higher tiers, which refine exposure and/or effect assessments using additional data. However, it is not possible to investigate the wide range of potential scenarios experimentally. In contrast, ecotoxicological mechanistic effect models do allow for addressing a multitude of scenarios. Furthermore, they may aid the interpretation of experiments such as mesocosm studies, allowing extrapolation to conditions not covered in experiments. Here, we explore how to use mechanistic effect models in the aquatic risk assessment of a model insecticide (Modelmethrin), applied several times per season but rapidly dissipating between applications. The case study focuses on potential effects on aquatic arthropods, the most sensitive group for this substance. The models provide information on the impact of a number of short exposure pulses on sensitive and/or vulnerable populations and, when impacted, assess recovery. The species to model were selected based on their sensitivity in laboratory and field (mesocosm) studies. The general unified threshold model for survival (GUTS) model, which describes the toxicokinetics and toxicodynamics of chemicals in individuals, was linked to 3 individual-based models (IBM), translating individual survival of sensitive organisms into population-level effects. The impact of pulsed insecticide exposures on populations were modeled using the spatially explicit IBM metapopulation model for assessing spatial and temporal effects of pesticides (MASTEP) for Gammarus pulex, the Chaoborus IBM for populations of Chaoborus crystallinus, and the "IdamP" model for populations of Daphnia magna. The different models were able to predict the potential effects of Modelmethrin applications to key arthropod

  4. Temporal changes in the level of neurotrophins in the spinal cord and associated precentral gyrus following spinal hemisection in adult Rhesus monkeys.

    PubMed

    Zhang, Hong-Tian; Gao, Zhi-Yu; Chen, Yi-Zhao; Wang, Ting-Hua

    2008-12-01

    Neurotrophins (NTs) appear to be crucial for the survival and potential regeneration of injured neurons. However, their temporal changes and remote regulations following spinal cord injury (SCI) have been only partially determined, especially in primates. In this study, ELISA was performed on the extracts of injured spinal cord and the associated precentral gyrus contralateral to the site of spinal cord hemisection to investigate the temporal changes in the levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) in adult rhesus monkeys subjected to T8 spinal hemisection. Animals were allowed to survive 3, 7, 14, 30 and 90 days post-operation (dpo). In the spinal cord, the levels of NGF, BDNF and NT-3 sharply decreased between 3 and 7dpo. Thereafter, the levels of NGF and BDNF were transiently elevated while NT-3 level continuously increased and recovered to normal level at 30dpo. In the contralateral precentral gyrus (cPG), only the NT-3 level was altered and in fact elevated above the normal value. No obvious changes were observed in NT-4 level in any of the regions studied. Taken together, the present findings indicated that intrinsic NGF, BDNF and NT-3 may play a local role in the responses to the SCI in primates. Especially, the increase of NT-3 level occurred continuously in both the cPG and the spinal cord pointed to a possible transportation of NT-3 to the cord following SCI.

  5. Multiple scales of temporal variability in ecosystem metabolism rates: results from two years of continuous monitoring in a forested headwater stream

    SciTech Connect

    Roberts, Brian J; Mulholland, Patrick J; Hill, Walter

    2007-01-01

    Headwater streams are key sites of nutrient and organic matter processing and retention, but little is known about temporal variability in gross primary production (GPP) and ecosystem respiration (ER) rates as a result of the short duration of most ecosystem metabolism measurements in lotic ecosystems. We examined temporal variability and controls on ecosystem metabolism by measuring daily rates continuously for two years in Walker Branch, a first-order deciduous forest stream. Four important scales of temporal variability in ecosystem metabolism rates were identified: (1) seasonal, (2) day-to-day, (3) episodic (storm-related), and (4) inter-annual. Seasonal patterns were largely controlled by the leaf phenology and productivity of the deciduous riparian forest. Walker Branch was strongly net heterotrophic throughout the year with the exception of the open-canopy spring when GPP and ER rates were similar. Day-to-day variability in weather conditions influenced light reaching the streambed, resulting in high day-to-day variability in GPP particularly during spring (daily light levels explained 84% of the variance in daily GPP in April). Episodic storms depressed GPP for several days in spring, but increased GPP in autumn by removing leaves shading the streambed. Storms depressed ER initially, but then stimulated ER to 2-3 times pre-storm levels for several days. Walker Branch was strongly net heterotrophic in both years of the study (NEP = -1156 and -773 g O2 m-2 y-1), with annual GPP being similar (488 and 519 g O2 m-2 y-1) but annual ER being higher in 2004 than 2005 (-1645 vs. -1292 g O2 m-2 y-1). Inter-annual variability in ecosystem metabolism (assessed by comparing 2004 and 2005 rates with previous measurements) was the result of the storm frequency and timing and the size of the spring macroalgal bloom. Changes in local climate can have substantial impacts on stream ecosystem metabolism rates and ultimately influence the carbon source and sink properties of

  6. Abnormal fatty acid pattern in the superior temporal gyrus distinguishes bipolar disorder from major depression and schizophrenia and resembles multiple sclerosis.

    PubMed

    McNamara, Robert K; Rider, Therese; Jandacek, Ronald; Tso, Patrick

    2014-03-30

    This study investigated the fatty acid composition of the postmortem superior temporal gyrus (STG), a cortical region implicated in emotional processing, from normal controls (n=15) and patients with bipolar disorder (BD, n=15), major depressive disorder (MDD, n=15), and schizophrenia (SZ, n=15). For comparative purposes, STG fatty acid composition was determined in a separate cohort of multiple sclerosis patients (MS, n=15) and normal controls (n=15). Compared with controls, patients with BD, but not MDD or SZ, exhibited abnormal elevations in the saturated fatty acids (SFA) palmitic acid (16:0), stearic acid (18:0), the polyunsaturated fatty acids (PUFA) linoleic acid (18:2n-6), arachidonic acid (20:4n-6), and docosahexaenoic acid (22:6n-3), and reductions in the monounsaturated fatty acid (MUFA) oleic acid (18:1n-9). The total MUFA/SFA and 18:1/18:0 ratios were lower in the STG of BD patients and were inversely correlated with total PUFA composition. MS patients exhibited a pattern of fatty acid abnormalities similar to that observed in BD patients including elevated PUFA and a lower 18:1/18:0 ratio. Collectively, these data demonstrate that BD patients exhibit a pattern of fatty acid abnormalities in the STG that is not observed in MDD and SZ patients and closely resembles MS patients.

  7. Development of Meta Level Communication Analysis using Temporal Data Crystallization and Its Application to Multi Modal Human Communication

    DTIC Science & Technology

    2013-07-22

    ABSTRACT The purpose of this project is to develop methods to analyse human communication using the temporal data crystallization (TDC). The major...hometowns rather than building a new workspace, for realizing his real and latent intention to expand the residential areas of customers. This intention...the condition that subshine become shed to the surrounding residential area , without failing to satisfy his own intention to expand business

  8. [Brief Neuropsychological Battery for multiple sclerosis. Normative data stratified by age and educational level].

    PubMed

    Duque, P; Oltra-Cucarella, J; Fernandez, O; Sepulcre, J; Grupo de Estudio de la Bateria Neuropsicologica Breve En la Esclerosis Multiple, Grupo de Estudio de la Bateria Neuropsicologica Breve En la Esclerosis Multiple

    2017-02-01

    Introduccion. La interpretacion del rendimiento en los tests cognitivos utilizados en la evaluacion neuropsicologica de pacientes con esclerosis multiple difiere en funcion del nivel educativo del evaluado. Objetivos. Aportar datos normativos de la bateria neuropsicologica breve (BNB) en la esclerosis multiple, estratificados por edad y nivel educativo, y demostrar la utilidad de la bateria para discriminar entre sujetos sanos y pacientes con esclerosis multiple. Sujetos y metodos. Se utilizaron los datos de 701 controles sanos de la muestra de baremacion original de la BNB en la esclerosis multiple, y se estratificaron por edad y nivel educativo mediante analisis de regresion de puntuaciones escalares. Se comparo el rendimiento del grupo control con un grupo de 112 pacientes con esclerosis multiple. Resultados. Se hallaron diferencias significativas entre los grupos en las variables de la BNB, en especial en tareas de velocidad de procesamiento, memoria de trabajo y memoria verbal. La edad y el sexo no mostraron efectos relevantes. Conclusiones. Los datos indican que la BNB en la esclerosis multiple es una herramienta sensible para identificar alteraciones cognitivas en la esclerosis multiple, con especial enfasis en las tareas de memoria de trabajo.

  9. Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina

    PubMed Central

    Frate, Ludovico; Acosta, Alicia T. R.; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

    2015-01-01

    The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979–2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (Pf) and structural connectivity (Pff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting Pf vs. Pff mean values and were compared across spatial extents. The distributions of Pf across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of Pf’s variability along with the increment of the mean slope of the Pf ‘s scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and

  10. Levels of 25 trace elements in high-volume air filter samples from Seville (2001-2002): Sources, enrichment factors and temporal variations

    NASA Astrophysics Data System (ADS)

    Enamorado-Báez, S. M.; Gómez-Guzmán, J. M.; Chamizo, E.; Abril, J. M.

    2015-03-01

    The measurement of trace element concentration in aerosols is of interest for environmental studies and for human health assessment. The temporal variability of total suspended particles (TSP) and its elemental composition in Seville, in SW Spain, is of particular complexity since Atlantic air masses and Saharan Dust Intrusions (SDI) overlap to local natural and anthropogenic sources. This paper is aimed to study the temporal evolution (in a monthly basis) of the concentrations of 25 trace elements, determined by ICP-MS, in high-volume air filter samples from Seville, covering a two-year period: 2001-2002. The mean TSP value for this period was 79.7 μg m- 3 and showed peak values in August 2001 and June 2002, likely related to SDI. Enrichment factors (EF) for Se, Sb and Zn and Pb were above 100, which revealed their anthropogenic sources. The comparison among EF from Seville and Huelva, a highly industrialized city nearby Seville, showed higher levels of anthropogenic elements there than in Seville. Simulations of the transport/dispersion of pollutants starting in Huelva confirm that air pollutants can reach Seville in the course of around 6 hours although they do not contribute significantly to the levels found in this city. A significant temporal correlation was found between elements which have a common source, being crustal (Al, Ti, Be, Co, Cs, Fe, Cr, Mn, U, Sr and Th) or anthropogenic sources (Zn, Pb, Cd). The temporal variations of those crustal elements are similar and related with the TSP levels for both years, with the clearly visible peaks probably related with the Saharan dust intrusion.

  11. Temporal trends (1989-2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ.

    PubMed

    Burger, Joanna

    2013-04-01

    There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey) did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1,470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2,669 ppb to 329 ppb)). Although mercury levels decreased from 2003-2008 (6,430 ppb to 1,042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2,610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6,430 ppb) are in the range associated with adverse effects (5,000 ppb for feathers).

  12. What role does the anterior temporal lobe play in sentence-level processing? Neural correlates of syntactic processing in semantic variant primary progressive aphasia.

    PubMed

    Wilson, Stephen M; DeMarco, Andrew T; Henry, Maya L; Gesierich, Benno; Babiak, Miranda; Mandelli, Maria Luisa; Miller, Bruce L; Gorno-Tempini, Maria Luisa

    2014-05-01

    Neuroimaging and neuropsychological studies have implicated the anterior temporal lobe (ATL) in sentence-level processing, with syntactic structure-building and/or combinatorial semantic processing suggested as possible roles. A potential challenge to the view that the ATL is involved in syntactic aspects of sentence processing comes from the clinical syndrome of semantic variant primary progressive aphasia (semantic PPA; also known as semantic dementia). In semantic PPA, bilateral neurodegeneration of the ATLs is associated with profound lexical semantic deficits, yet syntax is strikingly spared. The goal of this study was to investigate the neural correlates of syntactic processing in semantic PPA to determine which regions normally involved in syntactic processing are damaged in semantic PPA and whether spared syntactic processing depends on preserved functionality of intact regions, preserved functionality of atrophic regions, or compensatory functional reorganization. We scanned 20 individuals with semantic PPA and 24 age-matched controls using structural MRI and fMRI. Participants performed a sentence comprehension task that emphasized syntactic processing and minimized lexical semantic demands. We found that, in controls, left inferior frontal and left posterior temporal regions were modulated by syntactic processing, whereas anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the ATLs but extended to the posterior temporal regions involved in syntactic processing. Functional activity for syntactic processing was broadly similar in patients and controls; in particular, whole-brain analyses revealed no significant differences between patients and controls in the regions modulated by syntactic processing. The atrophic left ATL did show abnormal functionality in semantic PPA patients; however, this took the unexpected form of a failure to deactivate. Taken together, our findings indicate that spared

  13. A comprehensive emission inventory of multiple air pollutants from iron and steel industry in China: Temporal trends and spatial variation characteristics.

    PubMed

    Wang, Kun; Tian, Hezhong; Hua, Shenbing; Zhu, Chuanyong; Gao, Jiajia; Xue, Yifeng; Hao, Jiming; Wang, Yong; Zhou, Junrui

    2016-07-15

    China has become the largest producer of iron and steel throughout the world since 1996. However, as an energy-and-pollution intensive manufacturing sector, a detailed comprehensive emission inventory of air pollutants for iron and steel industry of China is still not available. To obtain and better understand the temporal trends and spatial variation characteristics of typical hazardous air pollutants (HAPs) emissions from iron and steel production in China, a comprehensive emission inventory of multiple air pollutants, including size segregated particulate matter (TSP/PM10/PM2.5), gaseous pollutants (SO2, NOx, CO), heavy metals (Pb, Cd, Hg, As, Cr, Ni etc.), as well as the more dangerous PCDD/Fs, is established with the unit-based annual activity, specific dynamic emission factors for the historical period of 1978-2011, and the future potential trends till to 2050 are forecasted by using scenario analysis. Our results show that emissions of gaseous pollutants and particulate matter have experienced a gradual increase tendency since 2000, while emissions of priority-controlled heavy metals (Hg, Pb, As, Cd, Cr, and Ni) have exhibited a short-term fluctuation during the period of 1990 to 2005. With regard to the spatial distribution of HAPs emissions in base year 2011, Bohai economic circle is identified as the top emission intensity region where iron and steel smelting plants are densely built; within iron and steel industry, blast furnaces contribute the majority of PM emissions, sinter plants account for most of gaseous pollutants and the majority of PCDD/Fs, whereas steel making processes are responsible for the majority of heavy metal emissions. Moreover, comparisons of future emission trends under three scenarios indicate that advanced technologies and integrated whole process management strategies are in great need to further diminish various hazardous air pollutants from iron and steel industry in the future.

  14. Temporal Gene Expression Analysis and RNA Silencing of Single and Multiple Members of Gene Family in the Lone Star Tick Amblyomma americanum

    PubMed Central

    Karim, Shahid

    2016-01-01

    Saliva is an integral factor in the feeding success of veterinary and medically important ticks. Therefore, the characterization of the proteins present in tick saliva is an important area of tick research. Here, we confirmed previously generated sialotranscriptome data using quantitative real-time PCR. The information obtained in this in-depth study of gene expression was used to measure the effects of metalloprotease gene silencing on tick feeding. We analyzed the temporal expression of seven housekeeping genes and 44 differentially expressed salivary molecules selected from a previously published Amblyomma americanum sialotranscriptome. Separate reference genes were selected for the salivary glands and midgut from among the seven housekeeping genes, to normalize the transcriptional expression of differentially expressed genes. The salivary gland reference gene, ubiquitin, was used to normalize the expression of 44 salivary genes. Unsurprisingly, each gene family was expressed throughout the blood meal, but the expression of specific genes differed at each time point. To further clarify the complex nature of the many proteins found in the saliva, we disrupted the translation of several members of the metalloprotease family. Intriguingly, the nucleotide sequence similarity of the reprolysin metalloprotease gene family is so homologous that a single synthesized dsRNA sequence knocked down multiple members of the family. The use of multigene knockdown yielded a more significant picture of the role of metalloproteases in tick feeding success, and changes were observed in the female engorgement weight and larval hatching success. Interestingly, the depletion of metalloprotease transcripts also reduced the total number of bacteria present in the salivary glands. These data provide insight into the expression and functions of tick salivary proteins expressed while feeding on its host. PMID:26872360

  15. Modeling for Fatigue Hysteresis Loops of Carbon Fiber-Reinforced Ceramic-Matrix Composites under Multiple Loading Stress Levels

    NASA Astrophysics Data System (ADS)

    Longbiao, Li

    2015-12-01

    In this paper, the fatigue hysteresis loops of fiber-reinforced ceramic-matrix composites (CMCs) under multiple loading stress levels considering interface wear has been investigated using micromechanical approach. Under fatigue loading, the fiber/matrix interface shear stress decreases with the increase of cycle number due to interface wear. Upon increasing of fatigue peak stress, the interface debonded length would propagate along the fiber/matrix interface. The difference of interface shear stress existed in the new and original debonded region would affect the interface debonding and interface frictional slipping between the fiber and the matrix. Based on the fatigue damage mechanism of fiber slipping relative to matrix in the interface debonded region upon unloading and subsequent reloading, the interface slip lengths, i.e., the interface debonded length, interface counter-slip length and interface new-slip length, are determined by fracture mechanics approach. The fatigue hysteresis loops models under multiple loading stress levels have been developed. The effects of single/multiple loading stress levels and different loading sequences on fatigue hysteresis loops have been investigated. The fatigue hysteresis loops of unidirectional C/SiC composite under multiple loading stress levels have been predicted.

  16. A Comparative Analysis of Multiple Intelligence Theory with Relationship to Gender and Grade Level in Selected Schools in Ghana

    ERIC Educational Resources Information Center

    Oteng, Ellen N.

    2012-01-01

    This dissertation examined the relationships between Howard Gardner's Multiple Intelligence Theory and students' gender, age, grade level, and enrollment into a public or private school. The research determined students' dominant intelligences and investigated whether students' intelligences may be influenced by demographic variables such as…

  17. Student Interactions with CD-ROM Storybooks: A Look at Potential Relationships between Multiple Intelligence Strengths and Levels of Interaction

    ERIC Educational Resources Information Center

    Huffman, Celia A.

    2012-01-01

    This study looked at the potential relationship that may exist between students' intelligence strengths, in particular their spatial and kinesthetic strengths, and their combined cognitive and metacognitive levels of interaction with a CD-ROM storybook. The multiple intelligence strengths of a sample of students, measured via the MIDAS/My…

  18. Development of multiple scattering polarization lidar to observe depolarization ratio of optically thick low level clouds

    NASA Astrophysics Data System (ADS)

    Okamoto, Hajime; Sato, Kaori; Nishizawa, Tomoaki; Sugimoto, Nobuo; Jin, Yoshitaka

    2017-02-01

    We have examined the characteristic of backscattering coefficient and depolarization ratio that are affected by multiple scattering in optically thick water clouds. We used observations obtained by the Multiple Field of view Multiple Scattering Polarization Lidar (MFMSPL) system. The MFMSPL was the first ground-based lidar that can detect depolarization ratio of optically thick clouds and it has 8 channels, i.e., 4 for parallel channels and another 4 for perpendicular ones and achieved total FOV of 70mrad. The MFMSPL offers a unique opportunity to simulate and study space-borne lidar signals including depolarization ratio such as from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar. It was shown that the attenuated backscattering coefficient and depolarization ratio constructed by using 8 channel observations by MFMSPL were comparable to the values obtained by CALIPSO lidar.

  19. Two-level hierarchy with sparsely and temporally coded patterns and its possible functional role in information processing.

    PubMed

    Nomura, Masaki; Aoyagi, Toshio; Okada, Masato

    2003-09-01

    We study the stability of two types of mixed states in an oscillator neural network model. Patterns to be stored are represented by complex variables whose amplitudes are either 0 (silent state) or 1 (firing state) and whose phases represent the timing of firing. The mixed states are defined in terms of a certain type of average over some specified number s of memory patterns. We define two types of such mixed states, each of which corresponds to a different type of restriction placed on this set of s memory patterns. The stability of each type is investigated both theoretically and numerically. We find that only one type of a mixed state, which consists of temporally correlated patterns, is stable. Finally, we discuss a possible functional role of such mixed states in information processing.

  20. Tolerable Levels of Nonclinical Vehicles and Formulations Used in Studies by Multiple Routes in Multiple Species With Notes on Methods to Improve Utility.

    PubMed

    Gad, Shayne Cox; Spainhour, Charles B; Shoemake, Catherine; Pallman, Danielle R Stackhouse; Stricker-Krongrad, Alain; Downing, Philip A; Seals, Richard E; Eagle, Leslie Anne; Polhamus, Kara; Daly, Jennifer

    2016-01-01

    Formulation of nonclinical evaluations is a challenge, with the fundamental need to achieve multiples of the clinical exposure complicated by differences in species and routes of administration-specific tolerances, depending on concentrations, volumes, dosing regimen, duration of each administration, and study duration. Current practice to approach these differences is based on individual experience and scattered literature with no comprehensive data source (the most notable exception being our 2006 publication on this same subject). Lack of formulation tolerance data results in excessive animal use, unplanned delays in the evaluation and development of drugs, and vehicle-dependent results. A consulting firm, a chemical company, and 4 contract research organizations conducted a rigorous data mining operation of vehicle data from studies dating from 1991 to 2015, enhancing the data from this author's 2006 publication (3 of the six 2015 contributors were also 2006 contributors). Additional data were found in the published literature. The results identified 108 single-component vehicles (and 305 combination formulations) used in more than 1,040 studies across multiple species (dog, primate, rat, mouse, rabbit, guinea pig, minipig, pig, chick embryo, and cat) by multiple routes for a wide range of study durations. The tabulated data include maximum tolerated use levels by species, route, duration of study, dose-limiting toxicity where reported, review of the available literature on each vehicle, guidance on syringe selection, volume and pH limits by route with basic guidance on nonclinical formulation development, and guidance on factors to be considered in nonclinical route selection.

  1. Spatial and temporal patterns of carabid activity-density in cereals do not explain levels of predation on weed seeds.

    PubMed

    Saska, P; van der Werf, W; de Vries, E; Westerman, P R

    2008-04-01

    Seed predation is an important component of seed mortality of weeds in agro-ecosystems, but the agronomic use and management of this natural weed suppression is hampered by a lack of insight in the underlying ecological processes. In this paper, we investigate whether and how spatial and temporal variation in activity-density of granivorous ground beetles (Coleoptera: Carabidae) results in a corresponding pattern of seed predation. Activity-density of carabids was measured by using pitfall traps in two organic winter wheat fields from March to July 2004. Predation of seeds (Capsella bursa-pastoris, Lamium amplexicaule, Poa annua and Stellaria media) was assessed using seed cards at the same sites and times. As measured by pitfall traps, carabids were the dominant group of insects that had access to the seed cards. In the field, predation of the four different species of seed was in the order: C. bursa-pastoris>P. annua>S. media>L. amplexicaule; and this order of preference was confirmed in the laboratory using the dominant species of carabid. On average, seed predation was higher in the field interior compared to the edge, whereas catches of carabids were highest near the edge. Weeks with elevated seed predation did not concur with high activity-density of carabids. Thus, patterns of spatial and temporal variation in seed predation were not matched by similar patterns in the abundance of granivorous carabid beetles. The lack of correspondence is ascribed to effects of confounding factors, such as weather, the background density of seeds, the composition of the carabid community, and the phenology and physiological state of the beetles. Our results show that differences in seed loss among weed species may be predicted from laboratory trials on preference. However, predator activity-density, as measured in pitfall traps, is an insufficient predictor of seed predation over time and space within a field.

  2. Salmon Migration Patterns Revealed the Temporal and Spatial Fluctuations of the Radiocesium Levels in Terrestrial and Ocean Environments

    PubMed Central

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3–40.2 Bq kg−1 in mean) and 137Cs (41.4–51.7 Bq kg−1 in mean) than did the anadromous (sea-run) type salmons (0.64–8.03 Bq kg−1 in mean 134Cs and 0.42–10.2 Bq kg−1 in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal. PMID:24964195

  3. Salmon migration patterns revealed the temporal and spatial fluctuations of the radiocesium levels in terrestrial and ocean environments.

    PubMed

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3-40.2 Bq kg(-1) in mean) and 137Cs (41.4-51.7 Bq kg(-1) in mean) than did the anadromous (sea-run) type salmons (0.64-8.03 Bq kg(-1) in mean 134Cs and 0.42-10.2 Bq kg(-1) in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal.

  4. "School" Reading and Multiple Texts: Examining the Metacognitive Development of Secondary-Level Preservice Teachers

    ERIC Educational Resources Information Center

    Lesley, Mellinee; Watson, Patricia; Elliot, Susan

    2007-01-01

    This practitioner-research study investigated the reading behaviors of preservice teachers from diverse content disciplines as they engaged in reading multiple texts pertaining to a historical topic. Through participant-observer field notes, reader response journals, reflective essays, and participant debriefing, the authors examined the…

  5. Population Size Predicts Lexical Diversity, but so Does the Mean Sea Level – Why It Is Important to Correctly Account for the Structure of Temporal Data

    PubMed Central

    Koplenig, Alexander; Müller-Spitzer, Carolin

    2016-01-01

    In order to demonstrate why it is important to correctly account for the (serial dependent) structure of temporal data, we document an apparently spectacular relationship between population size and lexical diversity: for five out of seven investigated languages, there is a strong relationship between population size and lexical diversity of the primary language in this country. We show that this relationship is the result of a misspecified model that does not consider the temporal aspect of the data by presenting a similar but nonsensical relationship between the global annual mean sea level and lexical diversity. Given the fact that in the recent past, several studies were published that present surprising links between different economic, cultural, political and (socio-)demographical variables on the one hand and cultural or linguistic characteristics on the other hand, but seem to suffer from exactly this problem, we explain the cause of the misspecification and show that it has profound consequences. We demonstrate how simple transformation of the time series can often solve problems of this type and argue that the evaluation of the plausibility of a relationship is important in this context. We hope that our paper will help both researchers and reviewers to understand why it is important to use special models for the analysis of data with a natural temporal ordering. PMID:26938719

  6. Temporal trends (1989–2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ

    SciTech Connect

    Burger, Joanna

    2013-04-15

    There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey) did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets.

  7. Lenalidomide affect expression level of cereblon protein in multiple myeloma cell line RPMI8226.

    PubMed

    Yang, D Y; Ren, J H; Guo, X N; Guo, X L; Cai, X Y; Guo, X F; Zhang, J N

    2015-10-29

    We investigated the mechanisms of action of immuno-modulatory drug (lenalidomide) on the protein expression of cereblon (CRBN) and their therapeutic targets in the multiple myeloma cell line RPMI8226. The multiple myeloma cell line RPMI8226 was cultured and treated with different concentrations of lenalidomide and bortezomib to determine the proliferation inhibition rate, apoptosis rate, and protein expression of CRBN. The results revealed that both lenalidomide and bortezomib inhibited the proliferation of RPMI8226 and promoted cell apoptosis. However, the protein expression of CRBN decreased signifi-cantly after treatment with lenalidomide, while bortezomib had no effect on the expression of CRBN. We confirmed that CRBN may be a target of lenalidomide.

  8. Illustrating the multiple facets and levels of fidelity of implementation to a teacher classroom management intervention.

    PubMed

    Reinke, Wendy M; Herman, Keith C; Stormont, Melissa; Newcomer, Lori; David, Kimberly

    2013-11-01

    Many school-based interventions to promote student mental health rely on teachers as implementers. Thus, understanding the interplay between the multiple domains of fidelity to the intervention and intervention support systems such as coaching and teacher implementation of new skills is an important aspect of implementation science. This study describes a systematic process for assessing multiple domains of fidelity. Data from a larger efficacy trial of the Incredible Years Teacher Classroom Management (IY TCM) program are utilized. Data on fidelity to the IY TCM workshop training sessions and onsite weekly coaching indicate that workshop leaders and the IY TCM coach implemented the training and coaching model with adequate adherence. Further, workshop leaders' ratings of engagement were associated with teacher implementation of specific praise, following training on this content. Lastly, the IY TCM coach differentiation of teacher exposure to coaching was evaluated and found to be associated with teacher implementation of classroom management practices and student disruptive behavior.

  9. Temporal Variation for the Expression of Catalase in DROSOPHILA MELANOGASTER: Correlations between Rates of Enzyme Synthesis and Levels of Translatable Catalase-Messenger RNA

    PubMed Central

    Bewley, Glenn C.; Mackay, William J.; Cook, Julia L.

    1986-01-01

    Two variants that alter the temporal expression of catalase have been isolated from a set of third chromosome substitution lines. Each variant has been mapped to a cytogenetic interval flanked by the visible markers st (3-44.0) and cu (3-50.0) at a map position of 47.0, which is within or near the interval 75D-76A previously identified as containing the catalase structural gene on the bases of dosage responses to segmental aneuploidy. Each variant operates by modulating the rate of enzyme synthesis and the level of translatable catalase-mRNA. PMID:3091448

  10. Temporal trends in the levels of metals, PCDD/Fs and PCBs in the vicinity of a municipal solid waste incinerator. Preliminary assessment of human health risks.

    PubMed

    Rovira, Joaquim; Vilavert, Lolita; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

    2015-09-01

    The concentrations of PCDD/Fs, PCBs, and metals were determined in soil and air samples collected near a municipal solid waste incinerator (MSWI) located in Mataró (Catalonia, Spain), being the health risks for the population living in the vicinity of the facility subsequently assessed. We also established the temporal trends with respect to previous surveys performed in the same zone. In general terms, the highest environmental levels of the pollutants were found in the city of Mataró and were independent on the distance to the MSWI. Soil levels of metals did not show temporal variations between the current and previous campaigns. However, the concentrations of metals in air samples collected in 2011 and 2013, were lower than those found in our 2008 survey. Regarding PCDD/Fs and PCBs, no differences were noted between the levels of the current survey and those corresponding to 2008. Anyhow, the concentrations of metals, PCDD/Fs, and PCBs in soils and air did not exceed the reference values established by regulatory organizations, being also in the low range of other similar studies recently reported. Finally, the human non-carcinogenic and carcinogenic risks due to exposure to metals, PCDD/Fs, and PCBs, were, for the population living in the neighborhood of the MSWI, considered as acceptable according to international standards.

  11. Enhanced levels of mitochondrial enzyme 17beta-hydroxysteroid dehydrogenase type 10 in patients with Alzheimer disease and multiple sclerosis.

    PubMed

    Kristofiková, Zdena; Bocková, Markéta; Hegnerová, Katerina; Bartos, Ales; Klaschka, Jan; Rícný, Jan; Rípová, Daniela; Homola, Jirí

    2009-10-01

    The multifunctional mitochondrial enzyme 17beta-hydroxysteroid dehydrogenase type 10 might play a role in the development of Alzheimer disease via its high-affinity binding to amyloid beta peptides and its neuronal over-expression. It is suggested that the cerebrospinal fluid levels of the enzyme, free or bound to amyloid beta peptides, are a potential specific biomarker of Alzheimer disease. However, mitochondrial dysfunction seems to play a role in many neurological diseases including multiple sclerosis. In this study, the specificity of changes in relation to the enzyme over-expression was evaluated using enzyme-linked immunosorbent and surface plasmon resonance sensors. The data indicated pronounced increases in the enzyme levels, specifically to 179% in multiple sclerosis and to 573% in Alzheimer disease when compared to the age-matched controls. Although the differences between both diseases were statistically significant, enzyme levels do not appear to be a highly specific biomarker of Alzheimer disease. On the other hand, enhancement in levels of the enzyme bound to amyloid beta peptides was only observed in people with Alzheimer disease, which suggests that the complex should be further considered as a possible biomarker. In patients with multiple sclerosis, our results are the first to demonstrate significant changes in enzyme expression and to suggest possible alterations in amyloid beta peptides.

  12. Isomer specific determination of hexabromocyclododecanes (HBCDs) in small cetaceans from the South China Sea--Levels and temporal variation.

    PubMed

    Isobe, Tomohiko; Ramu, Karri; Kajiwara, Natsuko; Takahashi, Shin; Lam, Paul K S; Jefferson, Thomas A; Zhou, Kaiya; Tanabe, Shinsuke

    2007-08-01

    A diastereoisomer (alpha, beta, and gamma) specific analytical method for measuring hexabromocyclododecanes (HBCDs) was developed using liquid chromatography-tandem mass spectrometry (LC-MS-MS). The method developed was applied to analyze blubber of small cetaceans to divulge the distribution and temporal variation of HBCDs in the Asian marine environment. HBCDs were detected in all the blubber samples of finless porpoises (Neophocaena phocaenoides) and Indo-Pacific humpback dolphins (Sousa chinensis) collected from the South China Sea during 1990-2001. Concentrations of HBCDs were higher in humpback dolphins (31-380 ng/g lipid) than in finless porpoises (4.7-55 ng/g lipid), which can be attributed to habitat differences. Average concentrations of alpha-HBCD in finless porpoises increased from 9.5 ng/g lipid in 1990 to 35 ng/g lipid in 2000/01. alpha-HBCD was predominant among the three isomers with some exceptions in finless porpoises collected in 1990. This is the first report on HBCDs contamination in marine mammals from Southeast Asia.

  13. Topology of Awareness: Therapeutic Implications of Logical Modalities of Multiple Levels of Awareness.

    ERIC Educational Resources Information Center

    Levine, Shellie

    2000-01-01

    Describes a theory of a topology of awareness, in which higher levels organize reality through dialectical logic, whereas lower levels construct reality based on Aristotelian logic, binary oppositions, and experiencing entities as discreet and independent. Argues that metaphor, poetry, and narrative are linguistic tools that enable clients to…

  14. Temporal and spatial variation in alkaloid levels in Achnatherum robustum, a native grass infected with the endophyte Neotyphodium.

    PubMed

    Faeth, Stanley H; Gardner, Dale R; Hayes, Cinnamon J; Jani, Andrea; Wittlinger, Sally K; Jones, Thomas A

    2006-02-01

    The native North American perennial grass Achnatherum robustum (Vasey) Barkworth [= Stipa robusta (Vasey) Scribn.] or sleepygrass is toxic and narcotic to livestock. The causative agents are alkaloidal mycotoxins produced from infections by a systemic and asexual Neotyphodium endophyte. Recent studies suggest that toxicity is limited across the range of sleepygrass in the Southwest USA. We sampled 17 populations of sleepygrass with varying distance from one focal population known for its high toxicity levels near Cloudcroft, NM, USA. For some, we sampled individual plants twice within the same growing season and over successive years (2001-2004). We also determined infection levels in each population. In general, all populations were highly infected, but infection levels were more variable near the focal population. Only infected plants within populations near the Cloudcroft area produced alkaloids. The ergot alkaloid, ergonovine, comprised the bulk of the alkaloids, with lesser amounts of lysergic and isolysergic acid amides and ergonovinine alkaloids. Levels of all alkaloids were positively correlated among individual plants within and between growing seasons. Infected plants that produced no alkaloids in 1 yr did not produce any alkaloids within the same growing season or in other years. Levels of alkaloids in sleepygrass populations declined with distance from the Cloudcroft population, although infection levels increased. Infected plants in populations in northern New Mexico and southern Colorado produced no alkaloids at all despite 100% infectivity. Our results suggest that only specific Neotyphodium haplotypes or specific Neotyphodium-grass combinations produce ergot alkaloids in sleepygrass. The Neotyphodium haplotype or host-endophyte combination that produces toxic levels of alkaloids appears restricted to one locality across the range of sleepygrass. Because of the wide variation in alkaloid levels among populations, interactions between the endophyte

  15. Multiple tests for wind turbine fault detection and score fusion using two- level multidimensional scaling (MDS)

    NASA Astrophysics Data System (ADS)

    Ye, Xiang; Gao, Weihua; Yan, Yanjun; Osadciw, Lisa A.

    2010-04-01

    Wind is an important renewable energy source. The energy and economic return from building wind farms justify the expensive investments in doing so. However, without an effective monitoring system, underperforming or faulty turbines will cause a huge loss in revenue. Early detection of such failures help prevent these undesired working conditions. We develop three tests on power curve, rotor speed curve, pitch angle curve of individual turbine. In each test, multiple states are defined to distinguish different working conditions, including complete shut-downs, under-performing states, abnormally frequent default states, as well as normal working states. These three tests are combined to reach a final conclusion, which is more effective than any single test. Through extensive data mining of historical data and verification from farm operators, some state combinations are discovered to be strong indicators of spindle failures, lightning strikes, anemometer faults, etc, for fault detection. In each individual test, and in the score fusion of these tests, we apply multidimensional scaling (MDS) to reduce the high dimensional feature space into a 3-dimensional visualization, from which it is easier to discover turbine working information. This approach gains a qualitative understanding of turbine performance status to detect faults, and also provides explanations on what has happened for detailed diagnostics. The state-of-the-art SCADA (Supervisory Control And Data Acquisition) system in industry can only answer the question whether there are abnormal working states, and our evaluation of multiple states in multiple tests is also promising for diagnostics. In the future, these tests can be readily incorporated in a Bayesian network for intelligent analysis and decision support.

  16. Understanding Children and Adolescents’ Victimizations at Multiple Levels: An Ecological Review of the Literature

    PubMed Central

    Sabri, Bushra; Hong, Jun Sung; Campbell, Jacquelyn C.; Cho, Hyunkag

    2013-01-01

    This article examines children and adolescent exposure to violence in various contexts. A systematic review of the literature was conducted to identify the definitions and types of violence reported in studies on victimization using the ecological systems framework. Sources included research studies and/or reports from scholarly journals (n = 140), books (n = 9), conference/workshops (n = 5), and web sources, such as Uniform Crime Reports (n = 23). The findings indicated that research differed in terminologies, conceptual and operational definitions, sample sizes and age group classification for children and adolescents. Further, studies lacked focus on the co-occurrence and inter-relatedness of victimization, and how these factors might affect the outcomes. Many studies employed a cross-sectional design, which limits strong conclusions about the temporal order of victimization experiences and outcomes. Future research efforts need more consistency among researchers in conceptual and operational definitions and the use of more rigorous designs. Increased holistic assessments are critical for effective prevention and intervention strategies for at-risk children and adolescents PMID:24065867

  17. The relationship between national-level carbon dioxide emissions and population size: an assessment of regional and temporal variation, 1960-2005.

    PubMed

    Jorgenson, Andrew K; Clark, Brett

    2013-01-01

    This study examines the regional and temporal differences in the statistical relationship between national-level carbon dioxide emissions and national-level population size. The authors analyze panel data from 1960 to 2005 for a diverse sample of nations, and employ descriptive statistics and rigorous panel regression modeling techniques. Initial descriptive analyses indicate that all regions experienced overall increases in carbon emissions and population size during the 45-year period of investigation, but with notable differences. For carbon emissions, the sample of countries in Asia experienced the largest percent increase, followed by countries in Latin America, Africa, and lastly the sample of relatively affluent countries in Europe, North America, and Oceania combined. For population size, the sample of countries in Africa experienced the largest percent increase, followed countries in Latin America, Asia, and the combined sample of countries in Europe, North America, and Oceania. Findings for two-way fixed effects panel regression elasticity models of national-level carbon emissions indicate that the estimated elasticity coefficient for population size is much smaller for nations in Africa than for nations in other regions of the world. Regarding potential temporal changes, from 1960 to 2005 the estimated elasticity coefficient for population size decreased by 25% for the sample of Africa countries, 14% for the sample of Asia countries, 6.5% for the sample of Latin America countries, but remained the same in size for the sample of countries in Europe, North America, and Oceania. Overall, while population size continues to be the primary driver of total national-level anthropogenic carbon dioxide emissions, the findings for this study highlight the need for future research and policies to recognize that the actual impacts of population size on national-level carbon emissions differ across both time and region.

  18. [Noise level measurements of the air noise during drilling and grinding on the fresh isolated temporal bone (author's transl)].

    PubMed

    Paulsen, K; Vietor, K

    1975-10-01

    Aerial sound measurements with different drilling instruments were performed during dry running and preparations of the bone. Registered were the values of the small drilling instruments Sirona, Dentatus-Air, and Electro-Torque-Ritter. Also tested were the KaVo-Technique-machine, the Hall-machine, the Air-Orbit-turbine, and the Sirona-turbine. During dry running most of them already reached the allowed marginal value of noise nuisance for the ear of 85 dB (A) at a distance of 35 cm. Only the Air-Orbit-machine showed a slightly lower value of 80 dB (A). The level increases with the used handpieces. Normal handpieces 1:1 exert only a minimal influence, gear handpieces 2:1, however, markedly increase the level. The verticity is of no importance in the range of normal rotations between 10,000 r/min. and 80,000 r/min. Only rotations in the lower frequency range of 2,000 r/min. markedly decrease the noise level. During bone drilling, the kind and size of the drilling bit have an influence on the intensity of the noise level. Quadruple wing milling cutters create a very high noise level (at a distance of 15 cm still above 110 dB [A!]), big rose cutters (R 16) create noise levels of 95 dB (A) and above, and only diamond round bits create less noise (approximately 88 db [A]). Small drilling bits make such a faint noise, that it is overroared by the drilling instrument. The turbines create only slightly higher levels than during dry running. Larger drilling bits cannot be employed here on principle. Wing milling cutters can lead to persistent damages of the inner ear. The frequent use of dental drilling instruments for bone preparations can also lead to a hearing loss of the operator in the long run.

  19. Temporal changes in nutritional state affect hypothalamic POMC peptide levels independently of leptin in adult male mice.

    PubMed

    Mercer, Aaron J; Stuart, Ronald C; Attard, Courtney A; Otero-Corchon, Veronica; Nillni, Eduardo A; Low, Malcolm J

    2014-04-15

    Hypothalamic proopiomelanocortin (POMC) neurons constitute a critical anorexigenic node in the central nervous system (CNS) for maintaining energy balance. These neurons directly affect energy expenditure and feeding behavior by releasing bioactive neuropeptides but are also subject to signals directly related to nutritional state such as the adipokine leptin. To further investigate the interaction of diet and leptin on hypothalamic POMC peptide levels, we exposed 8- to 10-wk-old male POMC-Discosoma red fluorescent protein (DsRed) transgenic reporter mice to either 24-48 h (acute) or 2 wk (chronic) food restriction, high-fat diet (HFD), or leptin treatment. Using semiquantitative immunofluorescence and radioimmunoassays, we discovered that acute fasting and chronic food restriction decreased the levels of adrenocorticotropic hormone (ACTH), α-melanocyte-stimulating hormone (α-MSH), and β-endorphin in the hypothalamus, together with decreased DsRed fluorescence, compared with control ad libitum-fed mice. Furthermore, acute but not chronic HFD or leptin administration selectively increased α-MSH levels in POMC fibers and increased DsRed fluorescence in POMC cell bodies. HFD and leptin treatments comparably increased circulating leptin levels at both time points, suggesting that transcription of Pomc and synthesis of POMC peptide products are not modified in direct relation to the concentration of plasma leptin. Our findings indicate that negative energy balance persistently downregulated POMC peptide levels, and this phenomenon may be partially explained by decreased leptin levels, since these changes were blocked in fasted mice treated with leptin. In contrast, sustained elevation of plasma leptin by HFD or hormone supplementation did not significantly alter POMC peptide levels, indicating that enhanced leptin signaling does not chronically increase Pomc transcription and peptide synthesis.

  20. Temporal changes in nutritional state affect hypothalamic POMC peptide levels independently of leptin in adult male mice

    PubMed Central

    Mercer, Aaron J.; Stuart, Ronald C.; Attard, Courtney A.; Otero-Corchon, Veronica; Nillni, Eduardo A.

    2014-01-01

    Hypothalamic proopiomelanocortin (POMC) neurons constitute a critical anorexigenic node in the central nervous system (CNS) for maintaining energy balance. These neurons directly affect energy expenditure and feeding behavior by releasing bioactive neuropeptides but are also subject to signals directly related to nutritional state such as the adipokine leptin. To further investigate the interaction of diet and leptin on hypothalamic POMC peptide levels, we exposed 8- to 10-wk-old male POMC-Discosoma red fluorescent protein (DsRed) transgenic reporter mice to either 24–48 h (acute) or 2 wk (chronic) food restriction, high-fat diet (HFD), or leptin treatment. Using semiquantitative immunofluorescence and radioimmunoassays, we discovered that acute fasting and chronic food restriction decreased the levels of adrenocorticotropic hormone (ACTH), α-melanocyte-stimulating hormone (α-MSH), and β-endorphin in the hypothalamus, together with decreased DsRed fluorescence, compared with control ad libitum-fed mice. Furthermore, acute but not chronic HFD or leptin administration selectively increased α-MSH levels in POMC fibers and increased DsRed fluorescence in POMC cell bodies. HFD and leptin treatments comparably increased circulating leptin levels at both time points, suggesting that transcription of Pomc and synthesis of POMC peptide products are not modified in direct relation to the concentration of plasma leptin. Our findings indicate that negative energy balance persistently downregulated POMC peptide levels, and this phenomenon may be partially explained by decreased leptin levels, since these changes were blocked in fasted mice treated with leptin. In contrast, sustained elevation of plasma leptin by HFD or hormone supplementation did not significantly alter POMC peptide levels, indicating that enhanced leptin signaling does not chronically increase Pomc transcription and peptide synthesis. PMID:24518677

  1. Temporal response of hydraulic head, temperature, and chloride concentrations to sea-level changes, Floridan aquifer system, USA

    NASA Astrophysics Data System (ADS)

    Hughes, J. D.; Vacher, H. L.; Sanford, Ward E.

    2009-06-01

    Three-dimensional density-dependent flow and transport modeling of the Floridan aquifer system, USA shows that current chloride concentrations are not in equilibrium with current sea level and, second, that the geometric configuration of the aquifer has a significant effect on system responses. The modeling shows that hydraulic head equilibrates first, followed by temperatures, and then by chloride concentrations. The model was constructed using a modified version of SUTRA capable of simulating multi-species heat and solute transport, and was compared to pre-development conditions using hydraulic heads, chloride concentrations, and temperatures from 315 observation wells. Three hypothetical, sinusoidal sea-level changes occurring over 100,000 years were used to evaluate how the simulated aquifer responds to sea-level changes. Model results show that hydraulic head responses lag behind sea-level changes only where the Miocene Hawthorn confining unit is thick and represents a significant restriction to flow. Temperatures equilibrate quickly except where the Hawthorn confining unit is thick and the duration of the sea-level event is long (exceeding 30,000 years). Response times for chloride concentrations to equilibrate are shortest near the coastline and where the aquifer is unconfined; in contrast, chloride concentrations do not change significantly over the 100,000-year simulation period where the Hawthorn confining unit is thick.

  2. Temporal response of hydraulic head, temperature, and chloride concentrations to sea-level changes, Floridan aquifer system, USA

    USGS Publications Warehouse

    Hughes, J.D.; Vacher, H.L.; Sanford, W.E.

    2009-01-01

    Three-dimensional density-dependent flow and transport modeling of the Floridan aquifer system, USA shows that current chloride concentrations are not in equilibrium with current sea level and, second, that the geometric configuration of the aquifer has a significant effect on system responses. The modeling shows that hydraulic head equilibrates first, followed by temperatures, and then by chloride concentrations. The model was constructed using a modified version of SUTRA capable of simulating multi-species heat and solute transport, and was compared to pre-development conditions using hydraulic heads, chloride concentrations, and temperatures from 315 observation wells. Three hypothetical, sinusoidal sea-level changes occurring over 100,000 years were used to evaluate how the simulated aquifer responds to sea-level changes. Model results show that hydraulic head responses lag behind sea-level changes only where the Miocene Hawthorn confining unit is thick and represents a significant restriction to flow. Temperatures equilibrate quickly except where the Hawthorn confining unit is thick and the duration of the sea-level event is long (exceeding 30,000 years). Response times for chloride concentrations to equilibrate are shortest near the coastline and where the aquifer is unconfined; in contrast, chloride concentrations do not change significantly over the 100,000-year simulation period where the Hawthorn confining unit is thick. ?? US Government 2008.

  3. Multiple Geodetic Observations for Identifying Glacial Isostatic Adjustment and the Causes of Sea-Level Change

    NASA Astrophysics Data System (ADS)

    Tamisiea, M. E.; Williams, S. D. P.; Hughes, C. W.; Bingley, R.; Blewitt, G.; Hammond, W. C.; Kreemer, C.

    2015-12-01

    Understanding the Earth's and ocean's response to past changes in global ice extent and ocean volume, collectively termed glacial isostatic adjustment (GIA), is necessary for interpreting observations of present-day sea level change. GIA has the largest effect on sea-level observations nearest the locations of the former ice sheets. Under the former loading centers, crustal uplift contributes to a local relative sea-level fall while the collapsing forebulge surrounding these centers accentuates a local sea-level rise. Some of the longest tide gauge records are in these regions. However, GIA also causes global deformation and geoid changes that introduce systematic differences between global averages of tide gauge and altimetry observations. Clearly accounting for the GIA contribution to sea-level change while identifying other present-day contributors is greatly assisted by additional geodetic measurements. Time-variable satellite gravity observations highlight the regional GIA signal, on length scales of hundreds of kilometers, while also locating water mass changes on the continents and the oceans. As the spatial density of GNSS observations has increased, it has become easier to discern the regional characteristics of crustal deformation (e.g. Blewitt et al. abstract in U009). Combined, these two observations allow for greater separation of GIA and water mass changes. More importantly for society, though, the regional crustal estimates could be combined with coastal altimetry products to create regional estimates of relative sea-level change, the observation most relevant for coastal planning. In this presentation we discuss how the various geodetic measurements complement each other and allow us to identify various components of sea level change, including GIA. We illustrate how the weakness of any individual observation component can be overcome by comparison with the other components. A sustained and global geodetic observing system is essential for

  4. High-throughput amplicon sequencing and stream benthic bacteria: identifying the best taxonomic level for multiple-stressor research

    PubMed Central

    Salis, R. K.; Bruder, A.; Piggott, J. J.; Summerfield, T. C.; Matthaei, C. D.

    2017-01-01

    Disentangling the individual and interactive effects of multiple stressors on microbial communities is a key challenge to our understanding and management of ecosystems. Advances in molecular techniques allow studying microbial communities in situ and with high taxonomic resolution. However, the taxonomic level which provides the best trade-off between our ability to detect multiple-stressor effects versus the goal of studying entire communities remains unknown. We used outdoor mesocosms simulating small streams to investigate the effects of four agricultural stressors (nutrient enrichment, the nitrification inhibitor dicyandiamide (DCD), fine sediment and flow velocity reduction) on stream bacteria (phyla, orders, genera, and species represented by Operational Taxonomic Units with 97% sequence similarity). Community composition was assessed using amplicon sequencing (16S rRNA gene, V3-V4 region). DCD was the most pervasive stressor, affecting evenness and most abundant taxa, followed by sediment and flow velocity. Stressor pervasiveness was similar across taxonomic levels and lower levels did not perform better in detecting stressor effects. Community coverage decreased from 96% of all sequences for abundant phyla to 28% for species. Order-level responses were generally representative of responses of corresponding genera and species, suggesting that this level may represent the best compromise between stressor sensitivity and coverage of bacterial communities. PMID:28327636

  5. High-throughput amplicon sequencing and stream benthic bacteria: identifying the best taxonomic level for multiple-stressor research

    NASA Astrophysics Data System (ADS)

    Salis, R. K.; Bruder, A.; Piggott, J. J.; Summerfield, T. C.; Matthaei, C. D.

    2017-03-01

    Disentangling the individual and interactive effects of multiple stressors on microbial communities is a key challenge to our understanding and management of ecosystems. Advances in molecular techniques allow studying microbial communities in situ and with high taxonomic resolution. However, the taxonomic level which provides the best trade-off between our ability to detect multiple-stressor effects versus the goal of studying entire communities remains unknown. We used outdoor mesocosms simulating small streams to investigate the effects of four agricultural stressors (nutrient enrichment, the nitrification inhibitor dicyandiamide (DCD), fine sediment and flow velocity reduction) on stream bacteria (phyla, orders, genera, and species represented by Operational Taxonomic Units with 97% sequence similarity). Community composition was assessed using amplicon sequencing (16S rRNA gene, V3-V4 region). DCD was the most pervasive stressor, affecting evenness and most abundant taxa, followed by sediment and flow velocity. Stressor pervasiveness was similar across taxonomic levels and lower levels did not perform better in detecting stressor effects. Community coverage decreased from 96% of all sequences for abundant phyla to 28% for species. Order-level responses were generally representative of responses of corresponding genera and species, suggesting that this level may represent the best compromise between stressor sensitivity and coverage of bacterial communities.

  6. Navigability of multiplex temporal network

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Song, Qiao-Zhen

    2017-01-01

    Real world complex systems have multiple levels of relationships and in many cases, they need to be modeled as multiplex networks where the same nodes can interact with each other in different layers, such as social networks. However, social relationships only appear at prescribed times so the temporal structures of edge activations can also affect the dynamical processes located above them. To consider both factors are simultaneously, we introduce multiplex temporal networks and propose three different walk strategies to investigate the concurrent dynamics of random walks and the temporal structure of multiplex networks. Thus, we derive analytical results for the multiplex centrality and coverage function in multiplex temporal networks. By comparing them with the numerical results, we show how the underlying topology of the layers and the walk strategy affect the efficiency when exploring the networks. In particular, the most interesting result is the emergence of a super-diffusion process, where the time scale of the multiplex is faster than that of both layers acting separately.

  7. Reproducing system-level bulk current injection test in direct power injection setup for multiple-port DUTs

    NASA Astrophysics Data System (ADS)

    Miropolsky, S.; Frei, S.

    2013-07-01

    Many investigations have been published on the transferability of RF immunity test results between system and IC-levels. The RF signal level at DUT (Device under Test) inputs, i.e. either RF voltage amplitude or RF input current, is used as a reference value for the load on the DUT. Existing approaches analyze the DUT response as a function of the RF signal level at a single input pin, e.g. supply voltage. Sufficient accuracy of such an approach could be shown in several cases, but results are not sufficient as a general solution for complex DUT. This paper proposes both theoretical analysis and practical implementation of a DPI setup, where a disturbance, equivalent to system-level BCI setup, can be delivered to multiple DUT input ports.

  8. Temporal trends in the levels of polychlorinated dioxins, -furans, -biphenyls and polybrominated diethyl ethers in bank voles in Northern Finland.

    PubMed

    Murtomaa-Hautala, Mari; Viluksela, Matti; Ruokojärvi, Päivi; Rautio, Arja

    2015-09-01

    Dioxin-like chemicals and brominated flame retardants are ubiquitous in the environment, despite the introduction of international prohibitions and restrictions. These chemicals do not remain in the vicinity of their source, instead they can be transported over long distances, in fact even to pristine areas in the northern latitudes. However, there have been rather few time series experiments monitoring the trends in the levels of chlorinated and brominated forms of these chemicals in the environment. In this study, the concentrations of polychlorinated dibenzo-p-dioxins and -furans (PCDDs/Fs), polychlorinated biphenyls (PCBs) and polybrominated diethyl ethers (PBDEs) were measured in the liver and muscle of bank voles (Myodes glareolus) caught in a remote area in Finnish Lapland during 1986-2007. Five time points were selected: years 1986, 1992, 1998, 2003 and 2007. The levels of PCDDs/Fs and PCBs declined from 1986 until 2003 in both females and males, but tended to increase again in 2007. The peak levels of the most abundant PBDE congeners (PBDEs 47, 99, 100 and 153) were measured in 1998 and 2003. These results reveal that the levels of dioxin-like chemicals remain high also in rural areas in Lapland, whereas the concentrations of brominated flame retardants decreased and follow the current restriction prohibitions.

  9. Measured and predicted temporal changes in soil nitrate-N levels from late summer to early spring in Montana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most soil sampling is conducted from August to November in Montana because of better soil sampling conditions and because it provides more time for growers to make fertilizer decisions prior to application. Fertilizer guidelines in Montana are based on spring nitrate-N levels in the upper 2 ft becau...

  10. Monitoring street-level spatial-temporal variations of carbon monoxide in urban settings using a wireless sensor network (WSN) framework.

    PubMed

    Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

    2013-11-27

    Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

  11. Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN) Framework

    PubMed Central

    Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

    2013-01-01

    Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management. PMID:24287859

  12. SyStemCell: A Database Populated with Multiple Levels of Experimental Data from Stem Cell Differentiation Research

    PubMed Central

    Zeng, Lingyao; Sun, Jiehuan; Li, Wei; Sun, Han; He, Ying; Li, Jing; Zhang, Guoqing; Wang, Chuan; Li, Yixue; Xie, Lu

    2012-01-01

    Elucidation of the mechanisms of stem cell differentiation is of great scientific interest. Increasing evidence suggests that stem cell differentiation involves changes at multiple levels of biological regulation, which together orchestrate the complex differentiation process; many related studies have been performed to investigate the various levels of regulation. The resulting valuable data, however, remain scattered. Most of the current stem cell-relevant databases focus on a single level of regulation (mRNA expression) from limited stem cell types; thus, a unifying resource would be of great value to compile the multiple levels of research data available. Here we present a database for this purpose, SyStemCell, deposited with multi-level experimental data from stem cell research. The database currently covers seven levels of stem cell differentiation-associated regulatory mechanisms, including DNA CpG 5-hydroxymethylcytosine/methylation, histone modification, transcript products, microRNA-based regulation, protein products, phosphorylation proteins and transcription factor regulation, all of which have been curated from 285 peer-reviewed publications selected from PubMed. The database contains 43,434 genes, recorded as 942,221 gene entries, for four organisms (Homo sapiens, Mus musculus, Rattus norvegicus, and Macaca mulatta) and various stem cell sources (e.g., embryonic stem cells, neural stem cells and induced pluripotent stem cells). Data in SyStemCell can be queried by Entrez gene ID, symbol, alias, or browsed by specific stem cell type at each level of genetic regulation. An online analysis tool is integrated to assist researchers to mine potential relationships among different regulations, and the potential usage of the database is demonstrated by three case studies. SyStemCell is the first database to bridge multi-level experimental information of stem cell studies, which can become an important reference resource for stem cell researchers. The database

  13. Coseismic water level changes induced by two distant earthquakes in multiple wells of the Chinese mainland

    NASA Astrophysics Data System (ADS)

    Ma, Yuchuan; Huang, Fuqiong

    2017-01-01

    Coseismic water level oscillations, or step-like rises and step-like drops were recorded in 159 wells throughout the Chinese mainland due to the 2015 Nepal Mw 7.8 earthquake, and 184 wells for the 2011 Japan Mw 9.0 earthquake. The earthquake magnitude, and the associated dynamic stresses, has positive roles in both the sensitivity of water level to earthquake induced change, and the amplitude and duration of resulting coseismic water level changes. Wells whose water levels are sensitive to Earth tides have high potential to response to earthquakes. Polarities of step-like changes (rises or drops) are locally controlled and spatially variable, with artesian wells generally recording water-level rises. Permeability enhancement was assessed as a mechanism responsible for step-like changes by analyzing the tidal phase responses. Permeability variations are inferred for 17 out of 95 wells with step-like changes during the Nepal earthquake and for 32 out of 105 wells following the Japan earthquake; however, only 6 wells have permeability variations after both earthquakes.

  14. Parallel evolution at multiple levels in the origin of hummingbird pollinated flowers in Ipomoea.

    PubMed

    Des Marais, David L; Rausher, Mark D

    2010-07-01

    A transition in flower color accompanying a shift in pollinator guilds is a prominent and repeated adaptation in angiosperms. In many cases, shifts to similar pollinators are associated with similar flower-color transitions. The extent to which this parallelism at the phenotypic level results from parallel changes at the biochemical, developmental, and genetic levels, however, remains an open question. There have been few attempts to determine whether parallelism at these lower levels results from mutation bias or fixation bias of different classes of mutation. We address these issues by examining the biochemical, developmental, and genetic changes that have occurred in red-flowering species of the Mina lineage of morning glories (Ipomoea) and compare these to the changes reported for I. horsfalliae, which has independently evolved red flowers. Using transgenic techniques, we demonstrate that the transition from blue to red flowers in Mina species is due primarily to down-regulation of the enzyme flavonol-3'-hydroxylase (F3'H) in flowers but not in vegetative tissues, and that this down-regulation is at least partly due to cis-regulatory change in the gene for F3'H. These changes are similar to those exhibited by I. horsfalliae, indicating parallelism at the biochemical and developmental levels, and possibly at the genetic level.

  15. Identifying Multiple Levels of Discussion-Based Teaching Strategies for Constructing Scientific Models

    NASA Astrophysics Data System (ADS)

    Williams, Grant; Clement, John

    2015-01-01

    This study sought to identify specific types of discussion-based strategies that two successful high school physics teachers using a model-based approach utilized in attempting to foster students' construction of explanatory models for scientific concepts. We found evidence that, in addition to previously documented dialogical strategies that teachers utilize to engage students in effectively communicating their scientific ideas in class, there is a second level of more cognitively focused model-construction-supporting strategies that these teachers utilized in attempting to foster students' learning. A further distinction between macro and micro strategy levels within the set of cognitive strategies is proposed. The relationships between the resulting three levels of strategies are portrayed in a diagramming system that tracks discussions over time. The study attempts to contribute to a clearer understanding of how discussion-leading strategies may be used to scaffold the development of conceptual understanding.

  16. Serum BAFF levels, Methypredsinolone therapy, Epstein-Barr Virus and Mycobacterium avium subsp. paratuberculosis infection in Multiple Sclerosis patients.

    PubMed

    Mameli, Giuseppe; Cocco, Eleonora; Frau, Jessica; Arru, Giannina; Caggiu, Elisa; Marrosu, Maria Giovanna; Sechi, Leonardo A

    2016-07-07

    Elevated B lymphocyte activating factor BAFF levels have been reported in multiple sclerosis (MS) patients; moreover, disease-modifying treatments (DMT) have shown to influence blood BAFF levels in MS patients, although the significance of these changes is still controversial. In addition, BAFF levels were reported increased during infectious diseases. In our study, we wanted to investigate on the serum BAFF concentrations correlated to the antibody response against Mycobacterium avium subspecies paratuberculosis (MAP), Epstein-Barr virus (EBV) and their human homologous epitopes in MS and in patients affected with other neurological diseases (OND), divided in Inflammatory Neurological Diseases (IND), Non Inflammatory Neurological Diseases (NIND) and Undetermined Neurological Diseases (UND), in comparison to healthy controls (HCs). Our results confirmed a statistically significant high BAFF levels in MS and IND patients in comparison to HCs but not NIND and UND patients. Interestingly, BAFF levels were inversely proportional to antibodies level against EBV and MAP peptides and the BAFF levels significantly decreased in MS patients after methylprednisolone therapy. These results implicate that lower circulating BAFF concentrations were present in MS patients with humoral response against MAP and EBV. In conclusion MS patients with no IgGs against EBV and MAP may support the hypothesis that elevated blood BAFF levels could be associated with a more stable disease.

  17. Serum BAFF levels, Methypredsinolone therapy, Epstein-Barr Virus and Mycobacterium avium subsp. paratuberculosis infection in Multiple Sclerosis patients

    PubMed Central

    Mameli, Giuseppe; Cocco, Eleonora; Frau, Jessica; Arru, Giannina; Caggiu, Elisa; Marrosu, Maria Giovanna; Sechi, Leonardo A.

    2016-01-01

    Elevated B lymphocyte activating factor BAFF levels have been reported in multiple sclerosis (MS) patients; moreover, disease-modifying treatments (DMT) have shown to influence blood BAFF levels in MS patients, although the significance of these changes is still controversial. In addition, BAFF levels were reported increased during infectious diseases. In our study, we wanted to investigate on the serum BAFF concentrations correlated to the antibody response against Mycobacterium avium subspecies paratuberculosis (MAP), Epstein-Barr virus (EBV) and their human homologous epitopes in MS and in patients affected with other neurological diseases (OND), divided in Inflammatory Neurological Diseases (IND), Non Inflammatory Neurological Diseases (NIND) and Undetermined Neurological Diseases (UND), in comparison to healthy controls (HCs). Our results confirmed a statistically significant high BAFF levels in MS and IND patients in comparison to HCs but not NIND and UND patients. Interestingly, BAFF levels were inversely proportional to antibodies level against EBV and MAP peptides and the BAFF levels significantly decreased in MS patients after methylprednisolone therapy. These results implicate that lower circulating BAFF concentrations were present in MS patients with humoral response against MAP and EBV. In conclusion MS patients with no IgGs against EBV and MAP may support the hypothesis that elevated blood BAFF levels could be associated with a more stable disease. PMID:27383531

  18. An Iterative Maximum a Posteriori Estimation of Proficiency Level to Detect Multiple Local Likelihood Maxima

    ERIC Educational Resources Information Center

    Magis, David; Raiche, Gilles

    2010-01-01

    In this article the authors focus on the issue of the nonuniqueness of the maximum likelihood (ML) estimator of proficiency level in item response theory (with special attention to logistic models). The usual maximum a posteriori (MAP) method offers a good alternative within that framework; however, this article highlights some drawbacks of its…

  19. Activities for Differentiated Instruction Addressing All Levels of Bloom's Taxonomy and Eight Multiple Intelligences.

    ERIC Educational Resources Information Center

    Rule, Audrey C., Ed.; Lord, Linda Hurley, Ed.

    This manuscript contains 13 curriculum units designed to enhance differentiated instruction for learners with special needs from grades 1-12, including gifted students. It integrates Benjamin S. Bloom's levels of cognitive understanding with Howard Gardner's eight domains of intelligence to provide a framework for individualized instruction. Each…

  20. Multiple Levels of Social Disadvantage and Links to Obesity in Adolescence and Young Adulthood

    ERIC Educational Resources Information Center

    Lee, Hedwig; Harris, Kathleen M.; Lee, Joyce

    2013-01-01

    Background: The rise in adolescent obesity has become a public health concern, especially because of its impact on disadvantaged youth. This article examines the role of disadvantage at the family-, peer-, school-, and neighborhood-level, to determine which contexts are related to obesity in adolescence and young adulthood. Methods: We analyzed…

  1. The Response of Spartina Alterniflora to Multiple Stressors of Eutrophication, Precipitation Changes, and Sea Level Rise

    EPA Science Inventory

    A four month experiment using greenhouse mesocosms was conducted to analyze the effects of eutrophication, sea level rise, and precipitation changes on the salt marsh plant Spartina alterniflora. Pots containing plants were placed in six 600L tanks that received seawater pumped f...

  2. Zinc Levels Modulate Lifespan through Multiple Longevity Pathways in Caenorhabditis elegans

    PubMed Central

    Kumar, Jitendra; Barhydt, Tracy; Awasthi, Anjali; Lithgow, Gordon J.; Killilea, David W.; Kapahi, Pankaj

    2016-01-01

    Zinc is an essential trace metal that has integral roles in numerous biological processes, including enzymatic function, protein structure, and cell signaling pathways. Both excess and deficiency of zinc can lead to detrimental effects on development and metabolism, resulting in abnormalities and disease. We altered the zinc balance within Caenorhabditis elegans to examine how changes in zinc burden affect longevity and healthspan in an invertebrate animal model. We found that increasing zinc levels in vivo with excess dietary zinc supplementation decreased the mean and maximum lifespan, whereas reducing zinc levels in vivo with a zinc-selective chelator increased the mean and maximum lifespan in C. elegans. We determined that the lifespan shortening effects of excess zinc required expression of DAF-16, HSF-1 and SKN-1 proteins, whereas the lifespan lengthening effects of the reduced zinc may be partially dependent upon this set of proteins. Furthermore, reducing zinc levels led to greater nuclear localization of DAF-16 and enhanced dauer formation compared to controls, suggesting that the lifespan effects of zinc are mediated in part by the insulin/IGF-1 pathway. Additionally, zinc status correlated with several markers of healthspan in worms, including proteostasis, locomotion and thermotolerance, with reduced zinc levels always associated with improvements in function. Taken together, these data support a role for zinc in regulating both development and lifespan in C. elegans, and that suggest that regulation of zinc homeostasis in the worm may be an example of antagonistic pleiotropy. PMID:27078872

  3. Levels and temporal trend of bisphenol A in composite food samples from Canadian Total Diet Study 2008-2012.

    PubMed

    Cao, Xu-Liang; Perez-Locas, Carolina; Robichaud, André; Clement, Genevieve; Popovic, Svetlana; Dufresne, Guy; Dabeka, Robert W

    2015-01-01

    Food composite samples from the Canadian Total Diet Study which was conducted each year from 2008 to 2012 rotating between different cities were analysed for bisphenol A (BPA). The overall levels of BPA in the composite food samples from each of the five years from 2008 to 2012 were similar in general with averages (range) of 7.7 ng/g (0.20-106 ng/g), 7.8 ng/g (0.26-110 ng/g), 6.9 ng/g (0.20-84 ng/g), 7.7 ng/g (0.20-105 ng/g) and 9.0 ng/g (0.15-90 ng/g) for 2008, 2009, 2010, 2011 and 2012, respectively. Levels of BPA in most of the non-canned food composite samples were low and no particular trends were observed. In contrast, the trend of BPA levels in canned food composite samples over the five years (2008-2012) varies. BPA levels in most of the canned food composite samples from 2008 to 2012 were consistent in general (e.g. canned luncheon meat: 10-18 ng/g, canned baked beans: 18-25 ng/g). While BPA levels over the five years were found to decrease for some canned food composite samples (e.g., canned fish: 109 ng/g in 2009 vs. 51 ng/g in 2012), they were also found to increase for some other canned food composite samples (e.g. canned meat soups: 90-104 ng/g in 2011-2012 vs. 29 ng/g in 2008). Thus, recent changes in can coating for food packaging to BPA-free alternatives may have not been fully reflected in all canned food products over the period from 2008 to 2012. Continued monitoring is necessary to more fully assess the potential impact on dietary exposure by the use of BPA alternatives in food contact materials.

  4. Accounting for Multiple Sources of Uncertainty in the Statistical Analysis of Holocene Sea Levels

    NASA Astrophysics Data System (ADS)

    Cahill, N.; Parnell, A. C.; Kemp, A.; Horton, B.

    2014-12-01

    We perform a Bayesian statistical analysis on historical and late Holocene rates of sea-level change. The data that form the input to the statistical model are tide-gauge measurements and proxy reconstructions from cores of coastal sediment. The aims are to estimate rates of sea-level change, to determine when modern rates of rise began and to observe how these rates have evolved over time. Many current methods for doing this use simple linear regression to estimate rates. This is often inappropriate as it is too rigid and it can ignore uncertainties that arise as part of the data collection exercise. This can lead to over-confidence in the sea-level trends being characterized. The proposed model places a Gaussian process prior on the rate process (i.e. the process that determines how rates of sea-level are changing over time). The likelihood of the observed data is the integral of this process. When dealing with proxy reconstructions, the model is set in an errors-in-variables framework so as to take account of age uncertainty. It is also necessary to account for glacio-isostatic adjustment, which introduces a covariance between individual age and sea-level observations. This method allows for the estimation of the rate process with full consideration of all sources of uncertainty. The model captures the continuous and dynamic evolution of sea-level change and results show that modern rates of rise are consistently increasing. Analysis of a global tide-gauge record (Church and White, 2011) indicated that the rate of sea-level rise increased continuously since 1880AD and is currently 1.9mm/yr (95% credible interval of 1.84 to 2.03mm/yr). Applying the model to a proxy reconstruction from North Carolina (Kemp et al., 2011) indicated that the mean rate of rise in this locality since the middle of the 19th century (current rate of 2.44 mm/yr with a 95% credible interval of 1.91 to 3.01mm/yr) is unprecedented in at least the last 2000 years.

  5. Global 5-Hydroxymethylcytosine Levels Are Profoundly Reduced in Multiple Genitourinary Malignancies

    PubMed Central

    Munari, Enrico; Chaux, Alcides; Vaghasia, Ajay M.; Taheri, Diana; Karram, Sarah; Bezerra, Stephania M.; Gonzalez Roibon, Nilda; Nelson, William G.; Yegnasubramanian, Srinivasan; Netto, George J.; Haffner, Michael C.

    2016-01-01

    Solid tumors are characterized by a plethora of epigenetic changes. In particular, patterns methylation of cytosines at the 5-position (5mC) in the context of CpGs are frequently altered in tumors. Recent evidence suggests that 5mC can get converted to 5-hydroxylmethylcytosine (5hmC) in an enzymatic process involving ten eleven translocation (TET) protein family members, and this process appears to be important in facilitating plasticity of cytosine methylation. Here we evaluated the global levels of 5hmC using a validated immunohistochemical staining method in a large series of clear cell renal cell carcinoma (n = 111), urothelial cell carcinoma (n = 55) and testicular germ cell tumors (n = 84) and matched adjacent benign tissues. Whereas tumor-adjacent benign tissues were mostly characterized by high levels of 5hmC, renal cell carcinoma and urothelial cell carcinoma showed dramatically reduced staining for 5hmC. 5hmC levels were low in both primary tumors and metastases of clear cell renal cell carcinoma and showed no association with disease outcomes. In normal testis, robust 5hmC staining was only observed in stroma and Sertoli cells. Seminoma showed greatly reduced 5hmC immunolabeling, whereas differentiated teratoma, embryonal and yolk sack tumors exhibited high 5hmC levels. The substantial tumor specific loss of 5hmC, particularly in clear cell renal cell carcinoma and urothelial cell carcinoma, suggests that alterations in pathways involved in establishing and maintaining 5hmC levels might be very common in cancer and could potentially be exploited for diagnosis and treatment. PMID:26785262

  6. Global 5-Hydroxymethylcytosine Levels Are Profoundly Reduced in Multiple Genitourinary Malignancies.

    PubMed

    Munari, Enrico; Chaux, Alcides; Vaghasia, Ajay M; Taheri, Diana; Karram, Sarah; Bezerra, Stephania M; Gonzalez Roibon, Nilda; Nelson, William G; Yegnasubramanian, Srinivasan; Netto, George J; Haffner, Michael C

    2016-01-01

    Solid tumors are characterized by a plethora of epigenetic changes. In particular, patterns methylation of cytosines at the 5-position (5mC) in the context of CpGs are frequently altered in tumors. Recent evidence suggests that 5mC can get converted to 5-hydroxylmethylcytosine (5hmC) in an enzymatic process involving ten eleven translocation (TET) protein family members, and this process appears to be important in facilitating plasticity of cytosine methylation. Here we evaluated the global levels of 5hmC using a validated immunohistochemical staining method in a large series of clear cell renal cell carcinoma (n = 111), urothelial cell carcinoma (n = 55) and testicular germ cell tumors (n = 84) and matched adjacent benign tissues. Whereas tumor-adjacent benign tissues were mostly characterized by high levels of 5hmC, renal cell carcinoma and urothelial cell carcinoma showed dramatically reduced staining for 5hmC. 5hmC levels were low in both primary tumors and metastases of clear cell renal cell carcinoma and showed no association with disease outcomes. In normal testis, robust 5hmC staining was only observed in stroma and Sertoli cells. Seminoma showed greatly reduced 5hmC immunolabeling, whereas differentiated teratoma, embryonal and yolk sack tumors exhibited high 5hmC levels. The substantial tumor specific loss of 5hmC, particularly in clear cell renal cell carcinoma and urothelial cell carcinoma, suggests that alterations in pathways involved in establishing and maintaining 5hmC levels might be very common in cancer and could potentially be exploited for diagnosis and treatment.

  7. A cross-cultural investigation of multiple intelligences in university-level nutrition students

    NASA Astrophysics Data System (ADS)

    Short, Joy E.

    Effective strategies for the recruitment and retention of a diverse student body in undergraduate nutrition and dietetics programs are needed in order for graduates to effectively meet the health and nutrition needs of a diverse clientele. One way to promote diversity and improve teaching methods in dietetics education is through a framework based on Howard Gardner's Theory of Multiple Intelligences (MI). The theory suggests that individuals possess varying degrees of eight different intelligences which are shaped by genetics and cultural context. Relatively little research has been conducted to investigate MI approaches in the areas of higher education, cross-cultural education, or dietetics education. Therefore, this study investigated the MI profiles of students within undergraduate nutrition programs at Universidad Iberoamericana in Mexico City, Mexico and Saint Louis University in St. Louis, Missouri, United States. Data were collected through the Multiple Intelligences Developmental Assessment Scales (MIDAS). The findings provide a profile of the intellectual dispositions for the study population and suggest that dietetics students in this cross-cultural study population score highest for the MIDAS scale measuring interpersonal intelligence, with significant differences occurring between scores for the eight intelligences measured by the MIDAS. Not only were there significant differences between scale scores when analyzing the population as a whole, there were also significant differences in scale scores when comparing American and Mexican students. This phenomenon was also true when scores were grouped into five ordinal categories. In addition, the findings suggest that differences exist among the particular skills associated with the intelligences for the students at each university. Results indicate that skills related to social sensitivity and persuasion are significantly higher than many other skills for dietetics students. Further, when comparing the

  8. Evolution of high-level, multiple anthelmintic resistance on a sheep farm in Malaysia.

    PubMed

    Chandrawathani, P; Waller, P J; Adnan, M; Höglund, J

    2003-02-01

    Anthelmintic resistance in nematode parasites of sheep and goats on a government farm in north Malaysia was monitored over a 3-year period (1997-2000). The faecal egg count reduction test (FECRT) was conducted on young sheep at the beginning and end of this period. Changes in management, designed to reduce the selection pressure for the development of anthelmintic resistance, were also implemented during this time. By far the most important parasite problem was Haemonchus contortus. In 1997, this nematode was found to be resistant to levamisole, with suspected resistance to closantel and moxidectin. However, when the FECRT was repeated 3 years later, its resistance status had become much more severe, with resistance to benzimidazole, levamisole and ivermectin, and suspected resistance to moxidectin. This rapid evolution to multiple anthelmintic resistance is a major concern that needs to be arrested. There is an urgent need to evaluate other control strategies that incorporate livestock management, the 'smart' use of drugs and non-chemotherapeutic approaches, such as biological control agents.

  9. PATTERNS OF EMOTIONAL AVAILABILITY IN MOTHER-INFANT DYADS: ASSOCIATIONS WITH MULTIPLE LEVELS OF CONTEXT.

    PubMed

    Mingo, M Verónica; Easterbrooks, M Ann

    2015-01-01

    This study explored emotional availability (EA)- an individual's emotional responsiveness and attunement to another's needs and goals (R.N. Emde, 1980)- among a high social risk group of 226 adolescent mothers and their infants (average = 12 months old). The aim was to identify dyadic patterns of EA and to examine their association with multiple indicators of the ecological context. Maternal sensitivity, maternal nonhostility, and child responsiveness were assessed with the Emotional Availability Scales, Third Edition (Z. Biringen, J. Robinson, & R.N. Emde, 1998) during free play and teaching observations at home. Four EA patterns were identified using k-means cluster analysis: (a) "low functioning," (b) "high functioning," (c) "low functioning dyads with nonhostile mothers," and (d) "inconsistently sensitive mother and responsive child." These patterns had distinct associations with (a) mothers' parenting attitudes regarding children's power and independence and parent-child role reversal, (b) mothers' strategies in conflict resolution with their partners and their children, and (c) the dyads' living arrangements. This study makes a contribution to the understanding of the mother-child relationship from a systemic and relational perspective and explores the association of EA patterns with the dyads' relational context. Implications for programs and treatment approaches aimed at supporting dyads at social risk are discussed.

  10. Phylogeny of a Genomically Diverse Group of Elymus (Poaceae) Allopolyploids Reveals Multiple Levels of Reticulation

    PubMed Central

    Mason-Gamer, Roberta J.

    2013-01-01

    The grass tribe Triticeae (=Hordeeae) comprises only about 300 species, but it is well known for the economically important crop plants wheat, barley, and rye. The group is also recognized as a fascinating example of evolutionary complexity, with a history shaped by numerous events of auto- and allopolyploidy and apparent introgression involving diploids and polyploids. The genus Elymus comprises a heterogeneous collection of allopolyploid genome combinations, all of which include at least one set of homoeologs, designated St, derived from Pseudoroegneria. The current analysis includes a geographically and genomically diverse collection of 21 tetraploid Elymus species, and a single hexaploid species. Diploid and polyploid relationships were estimated using four molecular data sets, including one that combines two regions of the chloroplast genome, and three from unlinked nuclear genes: phosphoenolpyruvate carboxylase, β-amylase, and granule-bound starch synthase I. Four gene trees were generated using maximum likelihood, and the phylogenetic placement of the polyploid sequences reveals extensive reticulation beyond allopolyploidy alone. The trees were interpreted with reference to numerous phenomena known to complicate allopolyploid phylogenies, and introgression was identified as a major factor in their history. The work illustrates the interpretation of complicated phylogenetic results through the sequential consideration of numerous possible explanations, and the results highlight the value of careful inspection of multiple independent molecular phylogenetic estimates, with particular focus on the differences among them. PMID:24302986

  11. Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River.

    PubMed

    Morrissette, Joëlle; Takser, Larissa; St-Amour, Genevieve; Smargiassi, Audrey; Lafond, Julie; Mergler, Donna

    2004-07-01

    Fish consumption from the Great Lakes and the St. Lawrence River has been decreasing over the last years due to advisories and increased awareness of the presence of several contaminants. Methylmercury (MeHg), a well-established neurotoxicant even at low levels of exposure, bioaccumulates to differing degrees in various fish species and can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Most studies on MeHg exposure have focussed on high-level consumers from local fish sources, although mercury (Hg) is also present in fresh, frozen, and canned market fish. Moreover, little information exists on the temporal variation of blood and hair Hg in pregnant women, particularly in populations with low levels of Hg. The aim of the present study was to characterize the temporal variation of Hg during pregnancy and to investigate the relation between fish consumption from various sources prior to and during pregnancy and maternal cord blood and mother's hair Hg levels. We recruited 159 pregnant women from Southwest Quebec through two prenatal clinics of the Quebec Public Health System. All women completed two detailed questionnaires concerning their fish consumption (species and frequency) prior to and during pregnancy. The women also provided blood samples for all three trimesters of pregnancy and hair samples after delivery of up to 9 cm in length. Blood and hair Hg levels were analyzed by cold-vapor atomic-absorption and -fluorescence spectrometry methods, respectively. Results showed that maternal blood and hair Hg levels decreased significantly between the second and third trimesters of pregnancy. However, cord blood Hg was significantly higher than maternal blood at birth. Maternal hair was correlated with Hg blood concentration and was highly predictive of the organic fraction in cord blood. A strong dose relation was observed between the frequency of fish consumption before and

  12. Cumulative annoyance due to multiple aircraft flyover with differing peak noise levels

    NASA Technical Reports Server (NTRS)

    Shepherd, K. P.

    1981-01-01

    A laboratory study in which 160 subjects judged the annoyance of 30 minute sessions of aircraft noise is described. Each session contained nine flyovers consisting of various combinations of three takeoff recordings of Boeing 727. The subjects were asked to judge their annoyance in the simulated living room environment of the laboratory and also to assess how annoyed they would be if they heard the noise in their home during the day, evening, and night periods. The standard deviation of the sound level did not improve the predictive ability of L sub eq (equivalent continuous sound level) which performed as well or better than other noise measured. Differences were found between the projected home responses for the day, evening, and nighttime periods. Time of day penalties derived from these results showed reasonable agreement with those currently used in community noise indices.

  13. Spatial and temporal evolution of the levels of tritium in the Tagus River in its passage through Caceres (Spain) and the Alentejo (Portugal).

    PubMed

    Baeza, A; Brogueira, A M; Carreiro, M C; García, E; Gil, J M; Miró, C; Sequeira, M M; Teixeira, M M

    2001-03-01

    This work is the result of a collaboration between Spanish and Portuguese laboratories. The specific objective was to quantify the time evolution during 1994, 1995 and 1996 of the radioecological impact of the liquid releases of 3H from the Almaraz Nuclear Power Plant (ANPP) in the section of the Tagus River corresponding to Cáceres province in Spain and the Alentejo region in Portugal. We found that the temporal evolution of the levels of tritium depends on the management of the water held in the cooling reservoir of the ANPP and the presence of the dams that exist along the river. This management regime has a 12-month period. Also the movement of the mass of tritiated water (HTO) downriver was much faster during 1996 than 1995 or 1994 due to the hydrological differences between those years and consequently to the different amounts of water transferred between the reservoirs of the dams. From the hypothesis that hydrodynamically it is impossible to differentiate tritiated water from non-tritiated water, a model was constructed that satisfactorily reproduces the temporal evolution of the 3H in the zone of the Tagus River in which the exchange of water takes place, with the cooling reservoir of the Almaraz Nuclear Power Plant.

  14. A High-Level Symbolic Representation for Intelligent Agents Across Multiple Architectures

    DTIC Science & Technology

    2004-07-01

    benefit from the higher level, cross-platform abstraction that HLSR provides. HLSR would provide a common foundation for these tools, assuring that they...changed during execution. This allows for more flexible execution while retaining the primary benefits of typing. HLSR provides two constructs for... cider <self>.contents.content end end o s trqp RequeotSpeedChangenessage isa Messagei =t~,,um-eruaation SpeedRequestTokens"Message intece

  15. Co-seismic water level changes in response to multiple large earthquakes at the LGH well in Sichuan, China

    NASA Astrophysics Data System (ADS)

    Lai, Guijuan; Jiang, Changsheng; Han, Libo; Sheng, Shuzhong; Ma, Yuchuan

    2016-06-01

    We examined the water level data at the LGH well in Sichuan, China, from December 2007 to July 2015 and their responses to multiple large earthquakes with seismic energy densities greater than 10- 4 J/m3. Co-seismic water level declines were observed in response to eleven earthquakes out of twelve in the farfield, and co-seismic water level increase was observed in one nearfield case. The water level declines in the farfield showed a linear relation with the common logarithm of the seismic energy densities, whereas the water level increase in the nearfield fell away from this relation, indicating that the farfield responses and the nearfield response were produced by distinct mechanisms. We used the phase shift of tidal responses as a proxy for permeability and found that permeability enhancements were observed both in the farfield and nearfield. The co-seismic water level declines in response to the distant earthquakes could be explained by permeability enhancements caused by the passage of seismic waves through the mobilization of colloidal particles; the co-seismic water level increase in response to the nearfield case could be caused both by the compression of the static stress and by the seismic waves.

  16. Level of education and multiple sclerosis risk after adjustment for known risk factors: The EnvIMS study

    PubMed Central

    Bjørnevik, Kjetil; Riise, Trond; Cortese, Marianna; Holmøy, Trygve; Kampman, Margitta T; Magalhaes, Sandra; Myhr, Kjell-Morten; Wolfson, Christina; Pugliatti, Maura

    2016-01-01

    Background: Several recent studies have found a higher risk of multiple sclerosis (MS) among people with a low level of education. This has been suggested to reflect an effect of smoking and lower vitamin D status in the social class associated with lower levels of education. Objective: The objective of this paper is to investigate the association between level of education and MS risk adjusting for the known risk factors smoking, infectious mononucleosis, indicators of vitamin D levels and body size. Methods: Within the case-control study on Environmental Factors In MS (EnvIMS), 953 MS patients and 1717 healthy controls from Norway reported educational level and history of exposure to putative environmental risk factors. Results: Higher level of education were associated with decreased MS risk (p trend = 0.001) with an OR of 0.53 (95% CI 0.41–0.68) when comparing those with the highest and lowest level of education. This association was only moderately reduced after adjusting for known risk factors (OR 0.61, 95% CI 0.44–0.83). The estimates remained similar when cases with disease onset before age 28 were excluded. Conclusion: These findings suggest that factors related to lower socioeconomic status other than established risk factors are associated with MS risk. PMID:26014605

  17. Human leukocyte telomere length is associated with DNA methylation levels in multiple subtelomeric and imprinted loci.

    PubMed

    Buxton, Jessica L; Suderman, Matthew; Pappas, Jane J; Borghol, Nada; McArdle, Wendy; Blakemore, Alexandra I F; Hertzman, Clyde; Power, Christine; Szyf, Moshe; Pembrey, Marcus

    2014-05-14

    In humans, leukocyte telomere length (LTL) is positively correlated with lifespan, and shorter LTL is associated with increased risk of age-related disease. In this study we tested for association between telomere length and methylated cytosine levels. Measurements of mean telomere length and DNA methylation at >450,000 CpG sites were obtained for both blood (N = 24) and EBV-transformed cell-line (N = 36) DNA samples from men aged 44-45 years. We identified 65 gene promoters enriched for CpG sites at which methylation levels are associated with leukocyte telomere length, and 36 gene promoters enriched for CpG sites at which methylation levels are associated with telomere length in DNA from EBV-transformed cell-lines. We observed significant enrichment of positively associated methylated CpG sites in subtelomeric loci (within 4 Mb of the telomere) (P < 0.01), and also at loci in imprinted regions (P < 0.001). Our results pave the way for further investigations to help elucidate the relationships between telomere length, DNA methylation and gene expression in health and disease.

  18. Speech perception and talker segregation: Effects of level, pitch, and tactile support with multiple simultaneous talkers

    NASA Astrophysics Data System (ADS)

    Drullman, Rob; Bronkhorst, Adelbert W.

    2004-11-01

    Speech intelligibility was investigated by varying the number of interfering talkers, level, and mean pitch differences between target and interfering speech, and the presence of tactile support. In a first experiment the speech-reception threshold (SRT) for sentences was measured for a male talker against a background of one to eight interfering male talkers or speech noise. Speech was presented diotically and vibro-tactile support was given by presenting the low-pass-filtered signal (0-200 Hz) to the index finger. The benefit in the SRT resulting from tactile support ranged from 0 to 2.4 dB and was largest for one or two interfering talkers. A second experiment focused on masking effects of one interfering talker. The interference was the target talker's own voice with an increased mean pitch by 2, 4, 8, or 12 semitones. Level differences between target and interfering speech ranged from -16 to +4 dB. Results from measurements of correctly perceived words in sentences show an intelligibility increase of up to 27% due to tactile support. Performance gradually improves with increasing pitch difference. Louder target speech generally helps perception, but results for level differences are considerably dependent on pitch differences. Differences in performance between noise and speech maskers and between speech maskers with various mean pitches are explained by the effect of informational masking. .

  19. Melatonin in Plants – Diversity of Levels and Multiplicity of Functions

    PubMed Central

    Hardeland, Rüdiger

    2016-01-01

    Melatonin has been detected in numerous plant species. A particularly surprising finding concerns the highly divergent levels of melatonin that vary between species, organs and environmental conditions, from a few pg/g to over 20 μg/g, reportedly up to 200 μg/g. Highest values have been determined in oily seeds and in plant organs exposed to high UV radiation. The divergency of melatonin concentrations is discussed under various functional aspects and focused on several open questions. This comprises differences in precursor availability, catabolism, the relative contribution of isoenzymes of the melatonin biosynthetic pathway, and differences in rate limitation by either serotonin N-acetyltransferase or N-acetylserotonin O-methyltransferase. Other differences are related to the remarkable pleiotropy of melatonin, which exhibits properties as a growth regulator and morphogenetic factor, actually debated in terms of auxin-like effects, and as a signaling molecule that modulates pathways of ethylene, abscisic, jasmonic and salicylic acids and is involved in stress tolerance, pathogen defense and delay of senescence. In the context of high light/UV intensities, elevated melatonin levels exceed those required for signaling via stress-related phytohormones and may comprise direct antioxidant and photoprotectant properties, perhaps with a contribution of its oxidatively formed metabolites, such as N1-acetyl-N2-formyl-5-methoxykynuramine and its secondary products. High melatonin levels in seeds may also serve antioxidative protection and have been shown to promote seed viability and germination capacity. PMID:26925091

  20. Nucella lapillus L. imposex levels after legislation prohibiting TBT antifoulants: temporal trends from 2003 to 2008 along the Portuguese coast.

    PubMed

    Galante-Oliveira, Susana; Oliveira, Isabel; Ferreira, Nelson; Santos, José António; Pacheco, Mário; Barroso, Carlos

    2011-02-01

    Nucella lapillus (dog whelk) imposex levels were assessed along the mainland Portuguese coast in 2006 and 2008 and were compared with available data from 2003 for the same area. Given that specimen size has been described as a factor inducing variation in some of the imposex assessment indices, and thus resulting in less reliable results, new monitoring and data analysis procedures are described and applied to study change of imposex levels from 2003 to 2008. A significant decline in imposex intensity was observed in the study area during the study period, and the Portuguese coast ecological status (under the terms defined by the OSPAR Commission) notably improved after 2003, confirming the effectiveness of the Regulation (EC) No. 782/2003 in reducing TBT pollution. Nevertheless, N. lapillus populations are still extensively affected by imposex, and fresh TBT inputs were detected in seawater throughout the coast in 2006. These recent inputs are attributed to vessels still carrying TBT antifoulants applied before 2003, as their presence in vessels was only forbidden in 2008. Considering that Regulation (EC) No. 782/2003 is an anticipation of the IMO global ban entered into force in September 2008, a worldwide-scale decrease in TBT pollution can be expected in the near future.

  1. Spatio-temporal profiling of Filamin A RNA-editing reveals ADAR preferences and high editing levels outside neuronal tissues

    PubMed Central

    Stulić, Maja; Jantsch, Michael F

    2013-01-01

    RNA editing by ADARs can change the coding potential of protein-coding mRNAs. So far, this type of RNA editing has mainly been shown to affect RNAs expressed in the nervous system with much lower editing levels being observed in other tissues. The actin crosslinking proteins filamin α and filamin β are widely expressed in most tissues. The mRNAs encoding either protein are edited at the same position leading to a conserved Q to R exchange in both proteins. Using bar-coded next generation sequencing, we show that editing of filamin α is most abundant in the gastrointestinal tract and only to a lesser extent in the nervous system. Using knockout mice, we show that ADARB1 (ADAR2) is responsible for the majority of FLNA editing, while ADAR1 can edit filamin α mRNA in some tissues quite efficiently. Interestingly, editing levels of filamin α and β do not follow the same trend across tissues, suggesting a substrate-specific regulation of editing. PMID:24025532

  2. Regulatory mechanisms of cAMP levels as a multiple target for antiplatelet activity and less bleeding risk.

    PubMed

    Fuentes, Eduardo; Palomo, Iván

    2014-08-01

    Platelet activation is a critical component of atherothrombosis. The multiple pathways of platelet activation limit the effect of specific receptor/pathway inhibitors, resulting in limited clinical efficacy. Recent research has confirmed that combination therapy results in enhanced antithrombotic efficacy without increasing bleeding risk. In this way, the best-known inhibitor and turn off signaling in platelet activation is cAMP. In this article we discuss the mechanisms of regulation of intraplatelet cAMP levels, a) platelet-dependent pathway: Gi/Gs protein-coupled receptors, phosphodiesterase inhibition and activation of PPARs and b) platelet-independent pathway: inhibition of adenosine uptake by erythrocytes. With respect to the association between intraplatelet cAMP levels and bleeding risk it is possible to establish that compounds/drugs with pleitropic effect for increased intraplatelet cAMP level could have an antithrombotic activity with less risk of bleeding.

  3. Predation on multiple trophic levels shapes the evolution of pathogen virulence.

    PubMed

    Friman, Ville-Petri; Lindstedt, Carita; Hiltunen, Teppo; Laakso, Jouni; Mappes, Johanna

    2009-08-25

    The pathogen virulence is traditionally thought to co-evolve as a result of reciprocal selection with its host organism. In natural communities, pathogens and hosts are typically embedded within a web of interactions with other species, which could affect indirectly the pathogen virulence and host immunity through trade-offs. Here we show that selection by predation can affect both pathogen virulence and host immune defence. Exposing opportunistic bacterial pathogen Serratia marcescens to predation by protozoan Tetrahymena thermophila decreased its virulence when measured as host moth Parasemia plantaginis survival. This was probably because the bacterial anti-predatory traits were traded off with bacterial virulence factors, such as motility or resource use efficiency. However, the host survival depended also on its allocation to warning signal that is used against avian predation. When infected with most virulent ancestral bacterial strain, host larvae with a small warning signal survived better than those with an effective large signal. This suggests that larval immune defence could be traded off with effective defence against bird predators. However, the signal size had no effect on larval survival when less virulent control or evolved strains were used for infection suggesting that anti-predatory defence against avian predators, might be less constrained when the invading pathogen is rather low in virulence. Our results demonstrate that predation can be important indirect driver of the evolution of both pathogen virulence and host immunity in communities with multiple species interactions. Thus, the pathogen virulence should be viewed as a result of both past evolutionary history, and current ecological interactions.

  4. Alendronate treatment alters bone tissues at multiple structural levels in healthy canine cortical bone.

    PubMed

    Acevedo, Claire; Bale, Hrishikesh; Gludovatz, Bernd; Wat, Amy; Tang, Simon Y; Wang, Mingyue; Busse, Björn; Zimmermann, Elizabeth A; Schaible, Eric; Allen, Matthew R; Burr, David B; Ritchie, Robert O

    2015-12-01

    Bisphosphonates are widely used to treat osteoporosis, but have been associated with atypical femoral fractures (AFFs) in the long term, which raises a critical health problem for the aging population. Several clinical studies have suggested that the occurrence of AFFs may be related to the bisphosphonate-induced changes of bone turnover, but large discrepancies in the results of these studies indicate that the salient mechanisms responsible for any loss in fracture resistance are still unclear. Here the role of bisphosphonates is examined in terms of the potential deterioration in fracture resistance resulting from both intrinsic (plasticity) and extrinsic (shielding) toughening mechanisms, which operate over a wide range of length-scales. Specifically, we compare the mechanical properties of two groups of humeri from healthy beagles, one control group comprising eight females (oral doses of saline vehicle, 1 mL/kg/day, 3 years) and one treated group comprising nine females (oral doses of alendronate used to treat osteoporosis, 0.2mg/kg/day, 3 years). Our data demonstrate treatment-specific reorganization of bone tissue identified at multiple length-scales mainly through advanced synchrotron x-ray experiments. We confirm that bisphosphonate treatments can increase non-enzymatic collagen cross-linking at molecular scales, which critically restricts plasticity associated with fibrillar sliding, and hence intrinsic toughening, at nanoscales. We also observe changes in the intracortical architecture of treated bone at microscales, with partial filling of the Haversian canals and reduction of osteon number. We hypothesize that the reduced plasticity associated with BP treatments may induce an increase in microcrack accumulation and growth under cyclic daily loadings, and potentially increase the susceptibility of cortical bone to atypical (fatigue-like) fractures.

  5. The Relationship between Multiplication Fact Speed-Recall and Fluency and Higher Level Mathematics Learning with Eighth Grade Middle School Students

    ERIC Educational Resources Information Center

    Curry, Steven James

    2012-01-01

    This quantitative study investigated relationships between higher level mathematics learning and multiplication fact fluency, multiplication fact speed-recall, and reading grade equivalency of eighth grade students in Algebra I and Pre-Algebra. Higher level mathematics learning was indicated by an average score of 80% or higher on first and second…

  6. Temporal variations of heavy metals levels in Perna viridis, on the Chacopata-Bocaripo lagoon axis, Sucre State, Venezuela.

    PubMed

    Pinto, Rafael; Acosta, Vanessa; Segnini, Mary Isabel; Brito, Leonor; Martínez, Gregorio

    2015-02-28

    Perna viridis was used as biomonitor to assess heavy metal levels in the Chacopata-Bocaripo lagoon axis, Venezuela, during rain and drought seasons. The mussels were weighed and measured. The metal concentrations were determined by atomic absorption spectrophotometry. For rain period, the order of bioavailability was: Cu>Ni>Mn>Co>Cd>Pb, and for drought: Cu>Mn>Ni>Co>Pb>Cd. The concentrations of Ni, Co, Cd and Pb showed significant differences (P<0.05) in both periods. There was higher metal accumulation during drought season, possibly related to upwelling, since it produces an increase in primary productivity, which translates more food into organisms, making metals bioavailable for mussels. Only Cu and Mn showed significant relationships between the size and metal concentration, during drought period, it may be because of the organisms need for these essential metals in different physiological processes.

  7. Temporal and spatial distributions of summer-time ground-level fine particulate matters in Baltimore-DC region

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Greenwald, R.; Sarnat, J.; Hu, X.; Kewada, P.; Morales, Y.; Goldman, G.; Redman, J.; Russell, A. G.

    2011-12-01

    Environmental epidemiological studies have established a robust association between chronic exposure to ambient level fine particulate matters (PM2.5) and adverse health effects such as COPD, cardiorespiratory diseases, and premature death. Population exposure to PM2.5 has historically been estimated using ground measurements which are often sparse and unevenly distributed. There has been much interest as well as suspicion in both the air quality management and research communities regarding the value of satellite retrieved AOD as particle air pollution indicators. A critical step towards the future use of satellite aerosol products in air quality monitoring and management is to better understand the AOD-PM2.5 association. The existing EPA and IMPROVE networks are insufficient to validate AOD-estimated PM2.5 surface especially when higher resolution satellite products become available in the near future. As part of DISCOVER-AQ mission, we deployed 15 portable filter-based samplers alongside of ground-based sun photometers of the Distributed Regional Aerosol Gridded Observation Network (DRAGON) in July 2011. Gravimetric analyses were conducted to estimate 24h PM2.5 mass concentrations, using Teflon filters and Personal Environmental Monitors (PEMs) operated at a flow rate of 4 LPM. Pre- and post-sampling filters were weighed at our weigh room laboratory facilities at the Georgia Institute of Technology. Our objectives are (1) to examine if AOD measured by ground-based sun-photometers with the support from ground-based lidars can provide the fine scale spatial heterogeneity observed by ground PM monitors, and (2) whether PM2.5 levels estimated by satellite AOD agree with this true PM2.5 surface. Study design, instrumentation, and preliminary results of measured PM2.5 spatial patterns in July 2011 will be presented as well as discussion of further data analysis and model development.

  8. Serum 25(OH) Vitamin D levels is not associated with disability in multiple sclerosis patients: A case-control study

    PubMed Central

    Nikanfar, Masoud; Taheri-Aghdam, Ali Akbar; Yazdani, Maria; Shaafi, Sheida; Masoudian, Nooshin; Akbari, Hossein; Youhanaee, Parisa; Abbaszadeh, Hamzeh

    2015-01-01

    Background: It seems that serum vitamin D levels are one of the potential environmental factors affecting the severity of multiple sclerosis (MS). In this study, we aim to evaluate vitamin D levels in MS patients and healthy subjects and assess the relationship between vitamin D level and disability. Methods: In this case-control study, 168 rapid relapsing MS patients and 168 matched healthy controls were randomly included in this study. Demographic characteristics and serum vitamin D levels for patients and controls, as well as expanded disability status scale (EDSS), duration of disease and diagnostic lag for patients were evaluated. We followed up patients for 6 months and relapses were recorded. Results: The mean serum vitamin D levels were 19.16 ± 17.37 inpatients and 25.39 ± 19.67 in controls (P = 0.560). The mean serum vitamin D levels were 12.65 ± 13.3 in patients with relapses and 22.08 ± 18.22 in patients without any relapses (P < 0.001). There was no significant correlation between EDSS score and serum vitamin D levels (r = −0.08, P = 0.280). There was a significant positive correlation between EDSS score and disease duration (r = 0.52, P < 0.001). Conclusion: In conclusion, vitamin D level in patients with MS was significantly lower than the healthy subjects, but no significant relationship was found between vitamin D levels and disability. Our findings did not suggest a protective role for serum vitamin D levels against disability. PMID:25874052

  9. Multiple Mechanisms Increase Levels of Resistance in Rapistrum rugosum to ALS Herbicides

    PubMed Central

    Hatami, Zahra M.; Gherekhloo, Javid; Rojano-Delgado, Antonia M.; Osuna, Maria D.; Alcántara, Ricardo; Fernández, Pablo; Sadeghipour, Hamid R.; De Prado, Rafael

    2016-01-01

    Rapistrum rugosum (turnip weed) is a common weed of wheat fields in Iran, which is most often controlled by tribenuron-methyl (TM), a sulfonylurea (SU) belonging to the acetolactate synthase (ALS) inhibiting herbicides group. Several cases of unexplained control failure of R. rugosum by TM have been seen, especially in Golestan province-Iran. Hence, there is lack of research in evaluation of the level of resistance of the R. rugosum populations to TM, using whole plant dose-response and enzyme assays, then investigating some potential resistance mechanisms Results revealed that the resistance factor (RF) for resistant (R) populations was 2.5–6.6 fold higher than susceptible (S) plant. Neither foliar retention, nor 14C-TM absorption and translocation were the mechanisms responsible for resistance in turnip weed. Metabolism of TM was the second resistant mechanism in two populations (Ag-R5 and G-1), in which three metabolites were found. The concentration of TM for 50% inhibition of ALS enzyme activity in vitro showed a high level of resistance to the herbicide (RFs were from 28 to 38) and cross-resistance to sulfonyl-aminocarbonyl-triazolinone (SCT), pyrimidinyl-thiobenzoate (PTB) and triazolopyrimidine (TP), with no cross-resistance to imidazolinone (IMI). Substitution Pro 197 to Ser 197 provided resistance to four of five ALS-inhibiting herbicides including SU, TP, PTB, and SCT with no resistance to IMI. These results documented the first case of R. rugosum resistant population worldwide and demonstrated that both RST and NRST mechanisms are involved to the resistance level to TM. PMID:26941749

  10. A comparative study of antiestrogen action: temporal patterns of antagonism of estrogen stimulated uterine growth and effects on estrogen receptor levels.

    PubMed

    Ferguson, E R; Katzenellenbogen, B S

    1977-05-01

    Studies were undertaken to ascertain the effects of structural modification of two well-known antiestrogens (CI-628 and U-11,100A) on their estrogenic and antiestrogenic potencies and temporal patterns of effectiveness in the immature rat uterus. Changes in the chemical structures of these anti-estrogens produce compounds with markedly different affinities for the uterine estrogen receptor as measured in an in vitro cell-free cytosol system; binding affinities relative to estradiol (100%) are: CI-628, 4%; CI-680, 34%; 94X1127 (94X),222%; U-11,100A (UA), 6%; and U-23,469 (U-23), 0.1%. Although all five antiestrogens (daily injections of 50 microng over three days) appear equally effective in stimulating 72 h uterine weight when given alone, or in blocking the estradiol-stimulated weight increase when given with estradiol, marked differences in their potencies are noted when the effects of the compounds are monitored beyond 24 h following a single injection. The compounds CI-628, CI-680 and UA (50 microng sc in saline), which have a methylated hydroxyl group (at the site analogous to the steroid position 3), show a prolonged maintenance of elevated levels of nuclear receptor (beyond 48 h) and elevated uterine weight (until 72 h); this correlates with a prolonged period of depressed cytoplasmic receptor levels (beyond 48 h) and prolonged uterine insensitivity to estrogen (beyond 36 h as monitored by 3 h wet weight response). In contrast, a single injection of 50 microng of 94X (having a free hydroxyl group) or U-23 (with a side chain and central ring different from UA) maintained nuclear receptor levels elevated for only 12 h (94X) or 36 h (U-23) and uterine weights declined after 36-48 h; cytoplasmic receptor levels remained depressed for only 12 h (94X) or 24 h (U-23) and then returned to control levels or above by 36 h. These latter compounds likewise evoked the shortest period of uterine insensitivity to estrogen (ineffective as antagonists by 36 h). Comparative

  11. Evaluation of Glutamic Acid Decarboxylase Antibody Levels in Patients with Juvenile Myoclonic Epilepsy and Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis

    PubMed Central

    CEYHAN DİRİCAN, Ayten; ELİBİRLİK, Sevilay; KÖKSAL, Ayhan; ÖZTÜRK, Musa; ALTUNKAYNAK, Yavuz; BAYBAŞ, Sevim; DİRİCAN, Ahmet

    2016-01-01

    Introduction Several clinical studies have been conducted to investigate the role of autoantibodies and immunological mechanisms in the etiology of treatment-resistant epilepsy in recent years. Some immunological treatments have been suggested as a result of these studies. In this study, we aimed to investigate the role of autoimmunity in partial and idiopathic generalized epilepsy and determine the relationship between drug resistance and autoimmune antibodies. Methods Twenty-eight patients (24 treatment-responsive and 4 treatment-resistant) with juvenile myoclonic epilepsy (JME), 26 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLEHS) resistant to antiepileptic drug treatment, and 26 age-matched healthy control subjects were included in a two-year cross sectional study. Glutamic acid decarboxylase antibody (GADA) levels were measured with a radioimmunoassay method in the serum of the included subjects. Results High GADA titers were detected in 2 patients with JME (7.1%), 1 patient with MTLEHS (3.8%), and 1 healthy subject (3.8%). There was no statistically significant difference among the groups regarding the serum GADA level. Although a limited number of drug-resistant patients with JME our study did not show relationships among anti-GADAs, both epileptic syndromes and drug resistance. Conclusion Because we did not determine any significant relationship between GADA levels and JME or MTLEHS, we do not recommend analysis of serum GADA levels in routine examinations where there is no evidence to suggest risk factors for autoimmunity. PMID:28373803

  12. Temporal invariance and clonal uniformity of brain and cerebrospinal IgG, IgA, and IgM in multiple sclerosis

    PubMed Central

    1986-01-01

    Elevated cerebrospinal fluid (CSF) IgG and oligoclonal IgG bands on electrophoresis are valuable clinical markers for B cell proliferation in the brains of patients with multiple sclerosis (MS). Using two- dimensional electrophoresis, (2DE) we have established that the humoral immune response in MS brain is characterized by finite clonal complexity for the major Ig classes. An important question is whether this immune response is clonally stable or varies with time, related to the development of new lesions and random entry of B cells into the MS brain. To investigate this, we performed serial electrophoretic studies on CSF obtained from 19 patients with MS; the intervals ranged from 7 to 12 yr, with a mean of 8 yr. These analyses included studies of IgG, IgA, and IgM, and revealed that the humoral immune response in MS is clonally stable over long periods. Spontaneous fluctuations or reduction in CSF IgG levels by drugs did not qualitatively affect B cell clonal proliferation in MS brain, in that dominant bands and spots were not obliterated. It has been asserted that IgG synthesis in MS is nonsense antibody because the spectotypes of IgG isolated from different regions of MS brains differ. Factors other than clonal heterogeneity could account for differences found using one-dimensional analysis. B cell clonal products resolve into unique and well-resolved spots by 2DE; the method is uniquely suitable for analysis of restricted immune responses. Therefore, Ig were isolated from 11 regions of three MS brains and the 2DE patterns were compared. The similarity of the 2DE patterns indicate unequivocally that major clones are distributed uniformly although some clones are more prominent in some brain areas. IgA and IgM isolated from the same areas also showed similar patterns. Furthermore, the patterns of light and heavy chains in brain regions differed from serum but were similar to the autologous CSF, providing new evidence that CSF IgG in MS derives from synthesis

  13. Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis

    PubMed Central

    Wright, Aidan G. C.; Beltz, Adriene M.; Gates, Kathleen M.; Molenaar, Peter C. M.; Simms, Leonard J.

    2015-01-01

    Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days) of maladaptive behaviors collected from a sample (N = 101) of individuals diagnosed with personality disorders (PDs). Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days) we found support for a two-factor Internalizing–Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals) we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Disinhibition structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic. PMID:26732546

  14. Effects of multiple levels of social organization on survival and abundance.

    PubMed

    Ward, Eric J; Semmens, Brice X; Holmes, Elizabeth E; Balcomb Iii, Ken C

    2011-04-01

    Identifying how social organization shapes individual behavior, survival, and fecundity of animals that live in groups can inform conservation efforts and improve forecasts of population abundance, even when the mechanism responsible for group-level differences is unknown. We constructed a hierarchical Bayesian model to quantify the relative variability in survival rates among different levels of social organization (matrilines and pods) of an endangered population of killer whales (Orcinus orca). Individual killer whales often participate in group activities such as prey sharing and cooperative hunting. The estimated age-specific survival probabilities and survivorship curves differed considerably among pods and to a lesser extent among matrilines (within pods). Across all pods, males had lower life expectancy than females. Differences in survival between pods may be caused by a combination of factors that vary across the population's range, including reduced prey availability, contaminants in prey, and human activity. Our modeling approach could be applied to demographic rates for other species and for parameters other than survival, including reproduction, prey selection, movement, and detection probabilities.

  15. Assessing the Health of Puget Sound's Pelagic Food Web at Multiple Trophic Levels

    NASA Astrophysics Data System (ADS)

    Rhodes, L. D.; Greene, C. M.; Rice, C. A.; Hall, J. E.; Baxter, A. E.; Naman, S. M.; Chamberlin, J.

    2012-12-01

    Puget Sound is an estuarine fjord in the northwestern United State surrounded by variable upland uses, ranging from industrial and urban to agricultural to forested lands. The quality of Puget Sound's ecosystem is under scrutiny because of the biological resources that depend on its function. In 2011, we undertook a study of the Sound's pelagic food web that measured water quality, microbial parameters, and abundance of higher trophic levels including gelatinous zooplankton, forage fish, and salmon. More than 75 sites spanning the latitudinal expanse of Puget Sound and the range of developed and agricultural land uses were sampled monthly from April to October. Strong relationships between water quality and microbial parameters suggest that microbes may modulate water quality indicators, such as dissolved inorganic nitrogen and pH, and that land use may be an influential factor. Basins within Puget Sound exhibit distinct biological profiles at the microbial and macrobiotic levels, emphasizing that Puget Sound is not a homogenous water body and suggesting that informative food web indicators may vary across the basins.

  16. Root-level exposure reveals multiple physiological toxicity of triazine xenobiotics in Arabidopsis thaliana.

    PubMed

    Alberto, Diana; Couée, Ivan; Sulmon, Cécile; Gouesbet, Gwenola

    2017-02-20

    Herbicides are pollutants of great concern due to environmental ubiquity resulting from extensive use in modern agriculture and persistence in soil and water. Studies at various spatial scales have also highlighted frequent occurrences of major herbicide breakdown products in the environment. Analysis of plant behavior toward such molecules and their metabolites under conditions of transient or persistent soil pollution is important for toxicity evaluation in the context of environmental risk assessment. In order to understand the mechanisms underlying the action of such environmental contaminants, the model plant Arabidopsis thaliana, which has been shown to be highly responsive to pesticides and other xenobiotics, was confronted with varying levels of the widely-used herbicide atrazine and of two of its metabolites, desethylatrazine and hydroxyatrazine, which are both frequently detected in water streams of agriculturally-intensive areas. After 24h of exposure to varying concentrations covering the range of triazine concentrations detected in the environment, root-level contaminations of atrazine, desethylatrazine and hydroxyatrazine were found to affect early growth and development in various dose-dependent and differential manners. Moreover, these differential effects of atrazine, desethylatrazine and hydroxyatrazine pointed to the involvement of distinct mechanisms directly affecting respiration and root development. The consequences of the identification of additional targets, in addition to the canonical photosystem II target, are discussed in relation with the ecotoxicological assessment of environmental xenobiotic contamination.

  17. Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis.

    PubMed

    Wright, Aidan G C; Beltz, Adriene M; Gates, Kathleen M; Molenaar, Peter C M; Simms, Leonard J

    2015-01-01

    Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days) of maladaptive behaviors collected from a sample (N = 101) of individuals diagnosed with personality disorders (PDs). Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days) we found support for a two-factor Internalizing-Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals) we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Disinhibition structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic.

  18. Temporal trends in geographic disparities in small-area-level colorectal cancer incidence and mortality in the United States

    PubMed Central

    Schootman, Mario; Lian, Min; Deshpande, Anjali D.; McQueen, Amy; Pruitt, Sandi L.; Jeffe, Donna B.

    2011-01-01

    Objective We examined the extent of changes in absolute and relative geographic disparities in six colorectal cancer (CRC) indicators using data about persons aged 50 and older from 195 counties in the 1988–2006 Surveillance, Epidemiology, and End Results Program database. Methods County-level trends in six colorectal cancer indicators (overall CRC incidence, descending colon cancer incidence, proximal colon cancer incidence, late-stage CRC incidence, CRC mortality, and 5-year probability of CRC death) were summarized using the estimated annual percentage change. Observed county rates were smoothed using Bayesian hierarchical spatiotemporal methods to calculate measures of absolute and relative geographic disparity and their changes over time. Results During the study period, absolute disparity for all six indicators decreased (CRC incidence: 43.2%; proximal colon cancer: 31.9%; descending colon cancer: 52.8%; late-stage CRC: 50.0%; CRC mortality: 57.8%; 5-year CRC-specific probability of death: 12.2%). Relative disparity remained stable for all six indicators over the entire study period. Conclusion Important progress has been made toward achieving the Healthy People 2010 and NCI strategic objectives for reducing geographic disparities, although absolute and relative disparities remain in CRC. PMID:21688130

  19. Temporal Variability of Upper-level Winds at the Eastern Range, Western Range and Wallops Flight Facility

    NASA Technical Reports Server (NTRS)

    Decker, Ryan K.; Barbre, Robert E., Jr.

    2014-01-01

    Space launch vehicle commit-to-launch decisions include an assessment of the upper-level (UL) atmospheric wind environment to assess the vehicle's controllability and structural integrity during ascent. These assessments occur at predetermined times during the launch countdown based on measured wind data obtained prior to the assessment. However, the pre-launch measured winds may not represent the wind environment during the vehicle ascent. Uncertainty in the UL winds over the time period between the assessment and launch can be mitigated by a statistical analysis of wind change over time periods of interest using historical data from the launch range. Without historical data, theoretical wind models must be used, which can result in inaccurate wind placards that misrepresent launch availability. Using an overconservative model could result in overly restrictive vehicle wind placards, thus potentially reducing launch availability. Conversely, using an under-conservative model could result in launching into winds that might damage or destroy the vehicle. A large sample of measured wind profiles best characterizes the wind change environment. These historical databases consist of a certain number of wind pairs, where two wind profile measurements spaced by the time period of interest define a pair.

  20. Understanding Spatial and Temporal Variability in Ozone Levels within a Remote-sensing Scale Grid Cell using Data Collected with Low-cost, Next Generation Monitoring Systems

    NASA Astrophysics Data System (ADS)

    Collier, A. M.; Hannigan, M.; Masson, N.; Piedrahita, R.; Gordon, J. L.; Russel, M.

    2014-12-01

    For the past several years, our research group has been developing low-cost (for reference, each unit costs under $1000) next generation air quality monitors, which utilize metal-oxide semiconductor sensors and non-dispersive infrared sensors to collect data on various gaseous pollutants. The pollutants of focus for this deployment were CO2, O3, and NO2. Additional data collected by the monitors includes temperature, humidity, wind speed and direction, and some information on hydrocarbon levels. A main focus of our research has been sensor characterization and exploring research applications of the technology. During summer 2014, the DISCOVER-AQ and FRAPPE sampling campaigns provided our group with the opportunity to deploy twenty monitors throughout the sampling region with the Boulder Atmospheric Observatory Tower in Erie CO at the center of our monitoring area. Thirteen of these monitors were located at ground-level within an approximately 10 by 10 km grid cell, and the rest were outside of this area at various distances. This placement was intended to provide information on pollutant variability, specifically ozone, within a remote-sensing sized grid cell. Additionally, the availability of reference monitors in the field provided opportunities for co-location during the deployment and hence, opportunities to quantify monitor performance. Analysis will include both an evaluation of low-cost sensor performance and a look at temporal and spatial variability. For example, land-use regression modeling will be used to explore population density, distance to roadways, and distance to oil and gas activity as covariates. Additionally, we will explore how the spatial distribution varies with time and look for temporal patterns.

  1. Pharmacoproteomic study of the natural product Ebenfuran III in DU-145 prostate cancer cells: the quantitative and temporal interrogation of chemically induced cell death at the protein level.

    PubMed

    Roumeliotis, Theodoros I; Halabalaki, Maria; Alexi, Xanthippi; Ankrett, Dyan; Giannopoulou, Eugenia G; Skaltsounis, Alexios-Leandros; Sayan, Berna S; Alexis, Michael N; Townsend, Paul A; Garbis, Spiros D

    2013-04-05

    A naturally occurring benzofuran derivative, Ebenfuran III (Eb III), was investigated for its antiproliferative effects using the DU-145 prostate cell line. Eb III was isolated from Onobrychis ebenoides of the Leguminosae family, a plant endemic in Central and Southern Greece. We have previously reported that Eb III exerts significant cytotoxic effects on certain cancer cell lines. This effect is thought to occur via the isoprenyl moiety at the C-5 position of the molecule. The study aim was to gain a deeper understanding of the pharmacological effect of Eb III on DU-145 cell death at the translational level using a relative quantitative and temporal proteomics approach. Proteins extracted from the cell pellets were subjected to solution phase trypsin proteolysis followed by iTRAQ-labeling. The labeled tryptic peptide extracts were then fractionated using strong cation exchange chromatography and the fractions were analyzed by nanoflow reverse phase ultraperformance liquid chromatography-nanoelectrospray ionization-tandem mass spectrometry analysis using a hybrid QqTOF platform. Using this approach, we compared the expression levels of 1360 proteins analyzed at ≤ 1% global protein false discovery rate (FDR), commonly present in untreated (control, vehicle only) and Eb III-treated cells at the different exposure time points. Through the iterative use of Ingenuity Pathway Analysis with hierarchical clustering of protein expression patterns, followed by bibliographic research, the temporal regulation of the Calpain-1, ERK2, PAR-4, RAB-7, and Bap31 proteins were identified as potential nodes of multipathway convergence to Eb III induced DU-145 cell death. These proteins were further verified with Western blot analysis. This gel-free, quantitative 2DLC-MS/MS proteomics method effectively captured novel modulated proteins in the DU-145 cell line as a response to Eb III treatment. This approach also provided greater insight to the multifocal and combinatorial signaling

  2. Understanding Physiology in the Continuum: Integration of Information from Multiple -Omics Levels

    PubMed Central

    Kamisoglu, Kubra; Acevedo, Alison; Almon, Richard R.; Coyle, Susette; Corbett, Siobhan; Dubois, Debra C.; Nguyen, Tung T.; Jusko, William J.; Androulakis, Ioannis P.

    2017-01-01

    In this paper, we discuss approaches for integrating biological information reflecting diverse physiologic levels. In particular, we explore statistical and model-based methods for integrating transcriptomic, proteomic and metabolomics data. Our case studies reflect responses to a systemic inflammatory stimulus and in response to an anti-inflammatory treatment. Our paper serves partly as a review of existing methods and partly as a means to demonstrate, using case studies related to human endotoxemia and response to methylprednisolone (MPL) treatment, how specific questions may require specific methods, thus emphasizing the non-uniqueness of the approaches. Finally, we explore novel ways for integrating -omics information with PKPD models, toward the development of more integrated pharmacology models. PMID:28289389

  3. Leading bureaucracies to the tipping point: An alternative model of multiple stable equilibrium levels of corruption.

    PubMed

    Caulkins, Jonathan P; Feichtinger, Gustav; Grass, Dieter; Hartl, Richard F; Kort, Peter M; Novak, Andreas J; Seidl, Andrea

    2013-03-16

    We present a novel model of corruption dynamics in the form of a nonlinear optimal dynamic control problem. It has a tipping point, but one whose origins and character are distinct from that in the classic Schelling (1978) model. The decision maker choosing a level of corruption is the chief or some other kind of authority figure who presides over a bureaucracy whose state of corruption is influenced by the authority figure's actions, and whose state in turn influences the pay-off for the authority figure. The policy interpretation is somewhat more optimistic than in other tipping models, and there are some surprising implications, notably that reforming the bureaucracy may be of limited value if the bureaucracy takes its cues from a corrupt leader.

  4. Changes in Blood B Cell-Activating Factor (BAFF) Levels in Multiple Sclerosis: A Sign of Treatment Outcome

    PubMed Central

    Kannel, Karin; Alnek, Kristi; Vahter, Liina; Gross-Paju, Katrin; Uibo, Raivo; Kisand, Kalle V.

    2015-01-01

    Multiple sclerosis (MS) is mediated primarily by autoreactive T cells. However, evidence suggesting the involvement of humoral immunity in brain diseases has increased interest in the role of B cells and their products during MS pathogenesis. The major survival factor for B cells, BAFF has been shown to play a role in several autoimmune conditions. Elevated BAFF levels have been reported in MS animal model and during MS relapse in patients. Moreover, disease-modifying treatments (DMT) reportedly influence blood BAFF levels in MS patients, but the significance of these changes remains unclear. The present study addresses how blood BAFF levels are associated with the clinical course of relapsing-remitting MS and the effectiveness of DMT and short-term steroid treatment. During a prospective longitudinal follow-up of 2.3 years, BAFF was measured in the blood of 170 MS patients in the stable phase and within 186 relapses. BAFF levels were significantly higher in MS patients compared to healthy controls. However, stable MS patients without relapses exhibited significantly higher BAFF levels than relapsing patients. Treatment with interferon-β and immunosuppressants raised BAFF blood levels. Interestingly, a similar effect was not seen in patients treated with glatiramer acetate. Short-term treatment with high doses of intravenous methylprednisolone did not significantly alter plasma BAFF levels in 65% of relapsing-remitting MS patients. BAFF were correlated weakly but significantly with monocyte and basophil counts, but not with other blood cell types (neutrophils, lymphocytes, or eosinophils) or inflammatory biomarkers. To our knowledge, this is the first report demonstrating that higher blood BAFF levels may reflect a more stable and effective MS treatment outcome. These results challenge hypotheses suggesting that elevated blood BAFF levels are associated with more severe disease presentation and could explain the recent failure of pharmaceutical trials targeting

  5. Cullin 1 functions as a centrosomal suppressor of centriole multiplication by regulating Polo-like kinase 4 protein levels

    PubMed Central

    Korzeniewski, Nina; Zheng, Leon; Cuevas, Rolando; Parry, Joshua; Chatterjee, Payel; Anderton, Brittany; Duensing, Anette; Münger, Karl; Duensing, Stefan

    2009-01-01

    Abnormal centrosome and centriole numbers are frequently detected in tumor cells where they can contribute to mitotic aberrations that cause chromosome missegregation and aneuploidy. The molecular mechanisms of centriole overduplication in malignant cells, however, are poorly characterized. Here, we show that the core SCF component CUL1 localizes to maternal centrioles and that CUL1 is critical for suppressing centriole overduplication through multiplication, a recently discovered mechanism whereby multiple daughter centrioles form concurrently at single maternal centrioles. We found that this activity of CUL1 involves the degradation of Polo-like kinase 4 (PLK4) at maternal centrioles. PLK4 is required for centriole duplication and strongly stimulates centriole multiplication when aberrantly expressed. We found that CUL1 is critical for the degradation of active PLK4 following deregulation of cyclin E/CDK2 activity, as is frequently observed in human cancer cells, as well as for baseline PLK4 protein stability. Collectively, our results suggest that CUL1 may function as a tumor suppressor by regulating PLK4 protein levels and thereby restraining excessive daughter centriole formation at maternal centrioles. PMID:19679553

  6. Effect of temperature, pH, and oxygen level on the multiplication of naturally occurring Legionella pneumophila in potable water.

    PubMed Central

    Wadowsky, R M; Wolford, R; McNamara, A M; Yee, R B

    1985-01-01

    A water culture containing naturally occurring Legionella pneumophila and associated microbiota was maintained in the laboratory by serially transferring the culture in tap water which had been sterilized by membrane filtration. Successful maintenance of the water culture depended upon transferring the culture when the growth of L. pneumophila was in the late-exponential to early-stationary phase. The water culture was used as a source of naturally occurring bacteria to determine some of the parameters which affect the multiplication of L. pneumophila in tap water. Naturally occurring L. pneumophila multiplied at a temperature between 25 and 37 degrees C, at pH levels of 5.5 to 9.2, and at concentrations of dissolved oxygen of 6.0 to 6.7 mg/liter. Multiplication did not occur in tap water which contained less than 2.2 mg of dissolved oxygen per liter. An association was observed between the multiplication of L. pneumophila and the non-Legionellaceae bacteria which were also present in the water culture. The method of preserving naturally occurring L. pneumophila and associated microbiota may facilitate studies on the symbiosis of L. pneumophila with other microorganisms. PMID:4004233

  7. Assessing spatial fluctuations, temporal variability, and measurement error in estimated levels of disinfection by-products in tap water: implications for exposure assessment

    PubMed Central

    Symanski, E; Savitz, D; Singer, P

    2004-01-01

    Aims: To assess spatial fluctuations, temporal variability, and errors due to sampling and analysis in levels of disinfection by-products in routine monitoring tap water samples and in water samples collected in households within the same distribution system for an exposure assessment study. Methods: Mixed effects models were applied to quantify seasonal effects and the degree to which trihalomethane (THM) levels vary among households or locations relative to variation over time within seasons for any given location. In a separate analysis, the proportion of total variation due to measurement error arising from sampling and analysis was also quantified. Results: THM levels were higher in the summer relative to other seasons. Differences in the relative magnitude of the intra- and inter-household components of variation were observed between the two sets of THM measurements, with a greater proportion of the variation due to differences within seasons for the routine monitoring data and a greater proportion of the variation due to differences across locations for the exposure assessment study data. Such differences likely arose due to differences in the strategies used to select sites for sampling and in the time periods over which the data were collected. With the exception of bromodichloromethane, measurement errors due to sampling and analysis contributed a small proportion of the total variation in THM levels. Conclusions: The utility of routine monitoring data in assigning exposure in epidemiological studies is limited because such data may not represent the magnitude of spatial variability in levels of disinfection by-products across the distribution system. Measurement error contributes a relatively small proportion to the total variation in THM levels, which suggests that gathering a greater number of samples over time with fewer replicates collected at each sampling location is more efficient and would likely yield improved estimates of household exposure

  8. The "Forgotten" Pseudomomenta and Gauge Changes in Generalized Landau Level Problems: Spatially Nonuniform Magnetic and Temporally Varying Electric Fields

    NASA Astrophysics Data System (ADS)

    Konstantinou, Georgios; Moulopoulos, Konstantinos

    2017-02-01

    By perceiving gauge invariance as an analytical tool in order to get insight into the states of the "generalized Landau problem" (a charged quantum particle moving inside a magnetic, and possibly electric field), and motivated by an early article that correctly warns against a naive use of gauge transformation procedures in the usual Landau problem (i.e. with the magnetic field being static and uniform), we first show how to bypass the complications pointed out in that article by solving the problem in full generality through gauge transformation techniques in a more appropriate manner. Our solution provides in simple and closed analytical forms all Landau Level-wavefunctions without the need to specify a particular vector potential. This we do by proper handling of the so-called pseudomomentum ěc {{K}} (or of a quantity that we term pseudo-angular momentum L z ), a method that is crucially different from the old warning argument, but also from standard treatments in textbooks and in research literature (where the usual Landau-wavefunctions are employed - labeled with canonical momenta quantum numbers). Most importantly, we go further by showing that a similar procedure can be followed in the more difficult case of spatially-nonuniform magnetic fields: in such case we define ěc {{K}} and L z as plausible generalizations of the previous ordinary case, namely as appropriate line integrals of the inhomogeneous magnetic field - our method providing closed analytical expressions for all stationary state wavefunctions in an easy manner and in a broad set of geometries and gauges. It can thus be viewed as complementary to the few existing works on inhomogeneous magnetic fields, that have so far mostly focused on determining the energy eigenvalues rather than the corresponding eigenkets (on which they have claimed that, even in the simplest cases, it is not possible to obtain in closed form the associated wavefunctions). The analytical forms derived here for these

  9. Estimation of water table level and nitrate pollution based on geostatistical and multiple mass transport models

    NASA Astrophysics Data System (ADS)

    Matiatos, Ioannis; Varouhakis, Emmanouil A.; Papadopoulou, Maria P.

    2015-04-01

    As the sustainable use of groundwater resources is a great challenge for many countries in the world, groundwater modeling has become a very useful and well established tool for studying groundwater management problems. Based on various methods used to numerically solve algebraic equations representing groundwater flow and contaminant mass transport, numerical models are mainly divided into Finite Difference-based and Finite Element-based models. The present study aims at evaluating the performance of a finite difference-based (MODFLOW-MT3DMS), a finite element-based (FEFLOW) and a hybrid finite element and finite difference (Princeton Transport Code-PTC) groundwater numerical models simulating groundwater flow and nitrate mass transport in the alluvial aquifer of Trizina region in NE Peloponnese, Greece. The calibration of groundwater flow in all models was performed using groundwater hydraulic head data from seven stress periods and the validation was based on a series of hydraulic head data for two stress periods in sufficient numbers of observation locations. The same periods were used for the calibration of nitrate mass transport. The calibration and validation of the three models revealed that the simulated values of hydraulic heads and nitrate mass concentrations coincide well with the observed ones. The models' performance was assessed by performing a statistical analysis of these different types of numerical algorithms. A number of metrics, such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), Bias, Nash Sutcliffe Model Efficiency (NSE) and Reliability Index (RI) were used allowing the direct comparison of models' performance. Spatiotemporal Kriging (STRK) was also applied using separable and non-separable spatiotemporal variograms to predict water table level and nitrate concentration at each sampling station for two selected hydrological stress periods. The predictions were validated using the respective measured values. Maps of water table

  10. Design and evaluation of multiple level data staging for Blue Gene systems.

    SciTech Connect

    Isaila, F.; Blas, J. G.; Carretero, J.; Latham, R.; Ross, R.

    2011-06-01

    Parallel applications currently suffer from a significant imbalance between computational power and available I/O bandwidth. Additionally, the hierarchical organization of current Petascale systems contributes to an increase of the I/O subsystem latency. In these hierarchies, file access involves pipelining data through several networks with incremental latencies and higher probability of congestion. Future Exascale systems are likely to share this trait. This paper presents a scalable parallel I/O software system designed to transparently hide the latency of file system accesses to applications on these platforms. Our solution takes advantage of the hierarchy of networks involved in file accesses, to maximize the degree of overlap between computation, file I/O-related communication, and file system access. We describe and evaluate a two-level hierarchy for Blue Gene systems consisting of client-side and I/O node-side caching. Our file cache management modules coordinate the data staging between application and storage through the Blue Gene networks. The experimental results demonstrate that our architecture achieves significant performance improvements through a high degree of overlap between computation, communication, and file I/O.

  11. Assimilation of benzene carbon through multiple trophic levels traced by different stable isotope probing methodologies.

    PubMed

    Bastida, Felipe; Jechalke, Sven; Bombach, Petra; Franchini, Alessandro G; Seifert, Jana; von Bergen, Martin; Vogt, Carsten; Richnow, Hans H

    2011-08-01

    The flow of benzene carbon along a food chain consisting of bacteria and eukaryotes, including larvae (Diptera: Chironomidae), was evaluated by total lipid fatty acids (TLFAs)-, amino acid- and protein-stable isotope probing (SIP). A coconut-fibre textile, colonized by a benzene-degrading biofilm, was sampled in a system established for the remediation of benzene, toluene, ethylbenzene and xylenes (BTEX)-polluted groundwater and incubated with (12)C- and [(13)C(6)]-benzene (>99 at.%) in a batch-scale experiment for 2-8 days. After 8 days, Chironomus sp. larvae were added to study carbon flow to higher trophic levels. Gas chromatography-combustion-isotope ratio monitoring mass spectrometry of TLFA showed increased isotope ratios in the (13)C-benzene-incubated biofilm. A higher (13)C-enrichment was observed in TLFAs, indicative of Gram-negative bacteria than for Gram-positive. Fatty acid indicators of eukaryotes showed significant (13)C-incorporation, but to a lower extent than bacterial indicators. Fatty acids extracted from larvae feeding on (13)C-biofilm reached an isotopic ratio of 1.55 at.%, illustrating that the larvae feed, to some extent, on labelled biomass. No (13)C-incorporation was detectable in larval proteins after their separation by sodium-dodecyl sulphate-polyacrylamide gel electrophoresis and analysis by nano-liquid-chromatography-mass spectrometry. The flow of benzene-derived carbon could be traced in a food web consisting of bacteria and eukaryotes.

  12. Efficient high light acclimation involves rapid processes at multiple mechanistic levels.

    PubMed

    Dietz, Karl-Josef

    2015-05-01

    Like no other chemical or physical parameter, the natural light environment of plants changes with high speed and jumps of enormous intensity. To cope with this variability, photosynthetic organisms have evolved sensing and response mechanisms that allow efficient acclimation. Most signals originate from the chloroplast itself. In addition to very fast photochemical regulation, intensive molecular communication is realized within the photosynthesizing cell, optimizing the acclimation process. Current research has opened up new perspectives on plausible but mostly unexpected complexity in signalling events, crosstalk, and process adjustments. Within seconds and minutes, redox states, levels of reactive oxygen species, metabolites, and hormones change and transmit information to the cytosol, modifying metabolic activity, gene expression, translation activity, and alternative splicing events. Signalling pathways on an intermediate time scale of several minutes to a few hours pave the way for long-term acclimation. Thereby, a new steady state of the transcriptome, proteome, and metabolism is realized within rather short time periods irrespective of the previous acclimation history to shade or sun conditions. This review provides a time line of events during six hours in the 'stressful' life of a plant.

  13. Temporal profile of inflammatory response to fracture and hemorrhagic shock: Proposal of a novel long-term survival murine multiple trauma model.

    PubMed

    Kleber, Christian; Becker, Christopher A; Malysch, Tom; Reinhold, Jens M; Tsitsilonis, Serafeim; Duda, Georg N; Schmidt-Bleek, Katharina; Schaser, Klaus D

    2015-07-01

    Hemorrhagic shock (hS) interacts with the posttraumatic immune response and fracture healing in multiple trauma. Due to the lack of a long-term survival multiple trauma animal models, no standardized analysis of fracture healing referring the impact of multiple trauma on fracture healing was performed. We propose a new long-term survival (21 days) murine multiple trauma model combining hS (microsurgical cannulation of carotid artery, withdrawl of blood and continuously blood pressure measurement), femoral (osteotomy/external fixation) and tibial fracture (3-point bending technique/antegrade nail). The posttraumatic immune response was measured via IL-6, sIL-6R ELISA. The hS was investigated via macrohemodynamics, blood gas analysis, wet-dry lung ration and histologic analysis of the shock organs. We proposed a new murine long-term survival (21 days) multiple trauma model mimicking clinical relevant injury patterns and previously published human posttraumatic immune response. Based on blood gas analysis and histologic analysis of shock organs we characterized and standardized our murine multiple trauma model. Furthermore, we revealed hemorrhagic shock as a causative factor that triggers sIL-6R formation underscoring the fundamental pathophysiologic role of the transsignaling mechanism in multiple trauma.

  14. Plasma Levels of Monocyte Chemotactic Protein-1 Are Associated with Clinical Features and Angiogenesis in Patients with Multiple Myeloma

    PubMed Central

    Valković, Toni; Babarović, Emina; Lučin, Ksenija; Štifter, Sanja; Aralica, Merica; Seili-Bekafigo, Irena; Duletić-Načinović, Antica; Jonjić, Nives

    2016-01-01

    The aim of this pilot study was to determine the plasma levels of monocyte chemotactic protein-1 (MCP-1) and possible associations with angiogenesis and the main clinical features of untreated patients with multiple myeloma (MM). ELISA was used to determine plasma MCP-1 levels in 45 newly diagnosed MM patients and 24 healthy controls. The blood vessels were highlighted by immunohistochemical staining, and computer-assisted image analysis was used for more objective and accurate determination of two parameters of angiogenesis: microvessel density (MVD) and total vascular area (TVA). The plasma levels of MCP-1 were compared to these parameters and the presence of anemia, renal dysfunction, and bone lesions. A significant positive correlation was found between plasma MCP-1 concentrations and TVA (p = 0.02). The MCP-1 levels were significantly higher in MM patients with evident bone lesions (p = 0.01), renal dysfunction (p = 0.02), or anemia (p = 0.04). Therefore, our preliminary results found a positive association between plasma MCP-1 levels, angiogenesis (expressed as TVA), and clinical features in patients with MM. However, additional prospective studies with a respectable number of patients should be performed to authenticate these results and establish MCP-1 as a possible target of active treatment. PMID:26925413

  15. Role of serum TRAIL level and TRAIL apoptosis gene expression in multiple sclerosis and relation to brain atrophy.

    PubMed

    Tawdy, Mohamed H; Abd El Nasser, Maged M; Abd El Shafy, Sanaa S; Nada, Mona A F; El Sirafy, Mohamed Nasr I; Magd, Amany Hussien Abol

    2014-09-01

    One of the presumed pathological mechanisms of multiple sclerosis (MS) is the failure of apoptosis of autoreactive T lymphocytes. This study aimed to determine the relationship of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA gene expression ratio and serum TRAIL levels with MS and brain atrophy. This study was conducted on 53 relapsing-remitting Egyptian MS patients and 25 matched healthy volunteers. The expression of TRAIL in peripheral blood lymphocytes was analyzed by reverse transcription polymerase chain reaction, serum levels of soluble TRAIL (sTRAIL) were determined by enzyme-linked immunosorbent assay and brain MRI measured "black holes" and the bicaudate ratio as a measure of brain atrophy in all patients. The serum TRAIL level was lower in MS patients compared to controls but no difference was seen in the TRAIL mRNA gene expression ratio. No significant correlation was detected between the serum TRAIL level and the TRAIL mRNA expression ratio in either group. No statistically significant correlation was found between serum TRAIL levels or the TRAIL mRNA expression ratio with the number of black holes or the bicaudate ratio on MRI. Apoptosis of T lymphocytes is decreased in MS patients, which could be useful when designing treatments. There was no difference in the TRAIL mRNA gene expression ratio between MS patients and controls.

  16. Elevated levels of a glycoprotein antigen (P-80) in gray and white matter of brain from victims of multiple sclerosis.

    PubMed

    Cruz, T F; Quackenbush, E J; Letarte, M; Moscarello, M A

    1986-06-01

    The levels of a glycoprotein reactive with monoclonal antibody (MAb) 44D10 in white and gray matter from brains of victims of several neurological diseases, including Multiple Sclerosis, Alzheimer's, Parkinson's and Huntington's diseases, were compared to that of normal individuals. The concentration of antigen reactive with MAb 44D10 was elevated in both gray and white matter of all MS brains examined, but not in brains with other neurological diseases. The increase in the concentration of antigen varied amongst the MS brains, such that the levels of antigen were only slightly increased in 2 of the 6 MS brains whereas 2 to 4 fold higher levels were found in the other 4 brains. Increased levels of antigen were detected in gray matter of MS brains, whereas this antigen was either not detected or present in very low levels in gray matter homogenates prepared from age-matched normal brains. MAb Leu 1, which reacts with T lymphocytes, was not absorbed by normal and MS brain tissue suggesting the increase in antigen reactive with MAb 44D10 in MS brain homogenates was not associated with non-specific infiltration by T lymphocytes. Comparison of the purified antigen from MS gray matter and normal white matter by gel electrophoresis demonstrated that MAb 44D10 was reacting with a similar protein in both tissues with an apparent molecular weight of 80K. We have named this molecule P-80 glycoprotein.

  17. Role of Therapeutic Plasma Exchange in Treatment of Tumefactive Multiple Sclerosis-Associated Low CD4 and CD8 Levels

    PubMed Central

    Lew, Kristen; Mewada, Nishith; Ramanujam, Sahana; Hassanzadeh, Bahareh; Donahue, John E.; Peddareddygari, Leema Reddy; Moser, Robert; Kososky, Charles; Grewal, Raji P.

    2016-01-01

    We report a 35-year-old healthy male who developed central nervous system inflammatory demyelinating disease consistent with tumefactive multiple sclerosis. About 2 weeks after onset of symptoms and prior to initiation of therapy, the patient had lymphopenia and low CD4 and CD8 levels. His lymphocyte count was 400 cells/µl (850–3,900 cells/µl), CD4 was 193 cells/µl (490–1,740 cells/µl) and CD8 was 103 cells/µl (180–1,170 cells/µl). He was treated with intravenous methylprednisolone followed by therapeutic plasma exchange, the levels of CD4 and CD8 normalized, and ultimately, he recovered completely. PMID:27721782

  18. The hierarchical structure of common mental disorders: Connecting multiple levels of comorbidity, bifactor models, and predictive validity.

    PubMed

    Kim, Hyunsik; Eaton, Nicholas R

    2015-11-01

    Studies of mental disorder comorbidity have produced an unsynthesized literature with multiple competing transdiagnostic models. The current study attempted to (a) integrate these models into an overarching comorbidity hierarchy, (b) link the resulting transdiagnostic factors to the bifactor model of psychopathology, and (c) investigate predictive validity of transdiagnostic factors for important future outcomes. A series of exploratory structural equation models (ESEMs) was conducted on 12 common mental disorders from a large, 2-wave nationally representative sample, using the bass-ackwards method to explore the hierarchical structure of transdiagnostic comorbidity factors. These Wave 1 factors were then linked with the bifactor model and with mental disorders at Wave 2. Results indicated that common mental disorder comorbidity was structured into an interpretable hierarchy. Connections between the hierarchy's general factor of psychopathology (denoted p), internalizing, and distress were very strong; these factors also linked strongly with the bifactor model's p factor. Predictive validity analyses prospectively predicting subsequent diagnoses indicated that, overall: (a) transdiagnostic factors outperformed disorder-specific variance; (b) within hierarchy levels, transdiagnostic factors where disorders optimally loaded outperformed other transdiagnostic factors, but this differed by disorder type; and (c) between hierarchy levels, transdiagnostic factors where disorders optimally loaded showed similar predictive validity. We discuss implications for hierarchical structure modeling, the integration of multiple competing comorbidity models, and benefits of transdiagnostic factors for understanding the continuity of mental disorders over time.

  19. Latitude has more significant impact on prevalence of multiple sclerosis than ultraviolet level or sunshine duration in Japanese population.

    PubMed

    Kinoshita, Masako; Obata, Kaoru; Tanaka, Masami

    2015-07-01

    Higher latitude is known to be associated with higher prevalence of multiple sclerosis (MS). We investigated the degree of impact of latitude, ultraviolet (UV) radiation, and sunshine on the prevalence of MS in Japan, which has 47 prefectures with a variety of climates. MS prevalence in each prefecture was collected from database of the Ministry of Health, Labour, and Welfare of Japan. Latitude of each prefecture was represented by that of the capital city. Data of UV radiation level and annual actual sunshine duration were obtained from databases of Japan Meteorological Agency. We performed linear correlation analyses of MS prevalence against latitude, UV radiation, and annual actual sunshine duration. MS prevalence significantly correlated to latitude (Pearson's correlation, r = 0.69, p < 0.001) and UV radiation level (r = -0.65, p < 0.001) but not to annual actual sunshine duration (r = -0.37, p = 0.011). Stepwise multiple linear regression analyses revealed significant correlation between MS prevalence and only latitude (p < 0.001). While our result shows that both latitude and the UV intensity have significant relationship to MS prevalence, the stronger relevance of the former suggests an existence of risk factors other than UV radiation.

  20. Monitoring In Vivo Changes in Tonic Extracellular Dopamine Level by Charge-Balancing Multiple Waveform Fast-Scan Cyclic Voltammetry.

    PubMed

    Oh, Yoonbae; Park, Cheonho; Kim, Do Hyoung; Shin, Hojin; Kang, Yu Min; DeWaele, Mark; Lee, Jeyeon; Min, Hoon-Ki; Blaha, Charles D; Bennet, Kevin E; Kim, In Young; Lee, Kendall H; Jang, Dong Pyo

    2016-11-15

    Dopamine (DA) modulates central neuronal activity through both phasic (second to second) and tonic (minutes to hours) terminal release. Conventional fast-scan cyclic voltammetry (FSCV), in combination with carbon fiber microelectrodes, has been used to measure phasic DA release in vivo by adopting a background subtraction procedure to remove background capacitive currents. However, measuring tonic changes in DA concentrations using conventional FSCV has been difficult because background capacitive currents are inherently unstable over long recording periods. To measure tonic changes in DA concentrations over several hours, we applied a novel charge-balancing multiple waveform FSCV (CBM-FSCV), combined with a dual background subtraction technique, to minimize temporal variations in background capacitive currents. Using this method, in vitro, charge variations from a reference time point were nearly zero for 48 h, whereas with conventional background subtraction, charge variations progressively increased. CBM-FSCV also demonstrated a high selectivity against 3,4-dihydroxyphenylacetic acid and ascorbic acid, two major chemical interferents in the brain, yielding a sensitivity of 85.40 ± 14.30 nA/μM and limit of detection of 5.8 ± 0.9 nM for DA while maintaining selectivity. Recorded in vivo by CBM-FSCV, pharmacological inhibition of DA reuptake (nomifensine) resulted in a 235 ± 60 nM increase in tonic extracellular DA concentrations, while inhibition of DA synthesis (α-methyl-dl-tyrosine) resulted in a 72.5 ± 4.8 nM decrease in DA concentrations over a 2 h period. This study showed that CBM-FSCV may serve as a unique voltammetric technique to monitor relatively slow changes in tonic extracellular DA concentrations in vivo over a prolonged time period.

  1. Forest fragmentation reduces parasitism via species loss at multiple trophic levels.

    PubMed

    Fenoglio, Maria Silvina; Srivastava, Diane; Valladares, Graciela; Cagnolo, Luciano; Salvo, Adriana

    2012-11-01

    Although there is accumulating evidence from artificially assembled communities that reductions of species diversity result in diminished ecosystem functioning, it is not yet clear how real-world changes in diversity affect the flow of energy between trophic levels in multi-trophic contexts. In central Argentina, forest fragmentation has led to species loss of plants, herbivore and parasitoid insects, decline in trophic processes (herbivory and parasitism), and food web contraction. Here we examine if and how loss of parasitoid species following fragmentation causes decreased parasitism rates, by analyzing food webs of leaf miners and parasitoids from 19 forest fragments of decreasing size. We asked three questions: Do reductions in parasitoid richness following fragmentation directly or indirectly affect parasitism rate? Are changes in community parasitism rate driven by changes in the parasitism rate of individual leaf miner species, or changes in leaf miner composition, or both? Which traits of species determine the effects of food web change on parasitism rates? We found that habitat loss initiated a bottom-up cascade of extinctions from plants to leaf miners to parasitoids, with reductions in parasitoid richness ultimately driving decreases in parasitism rates. This relationship between parasitoid richness and parasitism depended on changes in the relative abundance (but not occurrence) of leaf miners such that parasitoid-rich fragments were dominated by leaf miner species that supported high rates of parasitism. Surprisingly, we found that only a small subset of species in the food web could account for much of the increase in parasitism with parasitoid richness: lepidopteran miners that attained exceptionally high densities in some fragments and their largely specialist parasitoids. How specialized a parasitoid is, and the relative abundance of leaf miners, had important effects on the diversity-parasitism rate relationship, but not other leaf miner traits

  2. Managing temporal relations

    NASA Technical Reports Server (NTRS)

    Britt, Daniel L.; Geoffroy, Amy L.; Gohring, John R.

    1990-01-01

    Various temporal constraints on the execution of activities are described, and their representation in the scheduling system MAESTRO is discussed. Initial examples are presented using a sample activity described. Those examples are expanded to include a second activity, and the types of temporal constraints that can obtain between two activities are explored. Soft constraints, or preferences, in activity placement are discussed. Multiple performances of activities are considered, with respect to both hard and soft constraints. The primary methods used in MAESTRO to handle temporal constraints are described as are certain aspects of contingency handling with respect to temporal constraints. A discussion of the overall approach, with indications of future directions for this research, concludes the study.

  3. Levels of Daily Light Doses Under Changed Day-Night Cycles Regulate Temporal Segregation of Photosynthesis and N2 Fixation in the Cyanobacterium Trichodesmium erythraeum IMS101

    PubMed Central

    Cai, Xiaoni; Gao, Kunshan

    2015-01-01

    While the diazotrophic cyanobacterium Trichodesmium is known to display inverse diurnal performances of photosynthesis and N2 fixation, such a phenomenon has not been well documented under different day-night (L-D) cycles and different levels of light dose exposed to the cells. Here, we show differences in growth, N2 fixation and photosynthetic carbon fixation as well as photochemical performances of Trichodesmium IMS101 grown under 12L:12D, 8L:16D and 16L:8D L-D cycles at 70 μmol photons m-2 s-1 PAR (LL) and 350 μmol photons m-2 s-1 PAR (HL). The specific growth rate was the highest under LL and the lowest under HL under 16L:8D, and it increased under LL and decreased under HL with increased levels of daytime light doses exposed under the different light regimes, respectively. N2 fixation and photosynthetic carbon fixation were affected differentially by changes in the day-night regimes, with the former increasing directly under LL with increased daytime light doses and decreased under HL over growth-saturating light levels. Temporal segregation of N2 fixation from photosynthetic carbon fixation was evidenced under all day-night regimes, showing a time lag between the peak in N2 fixation and dip in carbon fixation. Elongation of light period led to higher N2 fixation rate under LL than under HL, while shortening the light exposure to 8 h delayed the N2 fixation peaking time (at the end of light period) and extended it to night period. Photosynthetic carbon fixation rates and transfer of light photons were always higher under HL than LL, regardless of the day-night cycles. Conclusively, diel performance of N2 fixation possesses functional plasticity, which was regulated by levels of light energy supplies either via changing light levels or length of light exposure. PMID:26258473

  4. Temporal Assessment of the Impact of Exposure to Cow Feces inTwo Watersheds by Multiple Host-Specific PCR Assays

    EPA Science Inventory

    Fecal exposure in two watersheds with different management histories was assessed by tracking cattle fecal bacterial populations using multiple host-specific PCR assays. In addition, environmental factors affecting the occurrence of these markers were identified. Each assay was t...

  5. Multiple rare variants in NPC1L1 associated with reduced sterol absorption and plasma low-density lipoprotein levels

    PubMed Central

    Cohen, Jonathan C.; Pertsemlidis, Alexander; Fahmi, Saleemah; Esmail, Sophie; Vega, Gloria L.; Grundy, Scott M.; Hobbs, Helen H.

    2006-01-01

    An approach to understand quantitative traits was recently proposed based on the finding that nonsynonymous (NS) sequence variants in certain genes are preferentially enriched at one extreme of the population distribution. The NS variants, although individually rare, are cumulatively frequent and influence quantitative traits, such as plasma lipoprotein levels. Here, we use the NS variant technique to demonstrate that genetic variation in NPC1L1 contributes to variability in cholesterol absorption and plasma levels of low-density lipoproteins (LDLs). The ratio of plasma campesterol (a plant sterol) to lathosterol (a cholesterol precursor) was used to estimate relative cholesterol absorption in a population-based study. Nonsynonymous sequence variations in NPC1L1 were five times more common in low absorbers (n = 26 of 256) than in high absorbers (n = 5 of 256) (P < 0.001). The rare variants identified in low absorbers were found in 6% of 1,832 African-Americans and were associated with lower plasma levels of LDL cholesterol (LDL-C) (96 ± 36 mg/dl vs. 105 ± 36 mg/dl; P = 0.005). These data, together with prior findings, reveal a genetic architecture for LDL-C levels that does not conform to current models for quantitative traits and indicate that a significant fraction of genetic variance in LDL-C is due to multiple alleles with modest effects that are present at low frequencies in the population. PMID:16449388

  6. High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment.

    PubMed

    Ozaktas, Tugba; Taskin, Bilgin; Gozen, Ayse G

    2012-12-01

    Freshwater fish, Alburnus alburnus (bleak), were captured from Lake Mogan, situated in Ankara, during spring. The surface mucus of the fish was collected and associated bacteria were cultured and isolated. By sequencing PCR-amplified 16S RNA encoding genes, the isolates were identified as members of 12 different genera: Acinetobacter, Aeromonas, Bacillus, Brevundimonas, Gordonia, Kocuria, Microbacterium, Mycobacterium, Pseudomonas, Rhodococcus, and Staphylococcus, in addition to one strain that was unidentified. The mucus-dwelling bacterial isolates were tested for resistance against ampicillin, kanamycin, streptomycin and chloramphenicol. About 95% of the isolates were found to be resistant to ampicillin, 93% to chloramphenicol, and 88% to kanamycin and streptomycin. A Microbacterium oxydans and the unidentified environmental isolate were resistant to all four antibiotics tested at very high levels (>1600 μg/ml ampicillin and streptomycin; >1120 μg/ml kanamycin; >960 μg/ml chloramphenicol). Only a Kocuria sp. was sensitive to all four antibiotics at the lowest concentrations tested (3.10 μg/ml ampicillin and streptomycin; 2.15 μg/ml kanamycin; 1.85 μg/ml chloramphenicol). The rest of the isolates showed different resistance levels. Plasmid isolations were carried out to determine if the multiple antibiotic resistance could be attributed to the presence of plasmids. However, no plasmid was detected in any of the isolates. The resistance appeared to be mediated by chromosome-associated functions. This study indicated that multiple antibiotic resistance at moderate to high levels is common among the current phenotypes of the fish mucus-dwelling bacterial populations in this temperate, shallow lake which has not been subjected to any aquaculturing so far but under anthropogenic effect being in a recreational area.

  7. Effective Visualization of Temporal Ensembles.

    PubMed

    Hao, Lihua; Healey, Christopher G; Bass, Steffen A

    2016-01-01

    An ensemble is a collection of related datasets, called members, built from a series of runs of a simulation or an experiment. Ensembles are large, temporal, multidimensional, and multivariate, making them difficult to analyze. Another important challenge is visualizing ensembles that vary both in space and time. Initial visualization techniques displayed ensembles with a small number of members, or presented an overview of an entire ensemble, but without potentially important details. Recently, researchers have suggested combining these two directions, allowing users to choose subsets of members to visualization. This manual selection process places the burden on the user to identify which members to explore. We first introduce a static ensemble visualization system that automatically helps users locate interesting subsets of members to visualize. We next extend the system to support analysis and visualization of temporal ensembles. We employ 3D shape comparison, cluster tree visualization, and glyph based visualization to represent different levels of detail within an ensemble. This strategy is used to provide two approaches for temporal ensemble analysis: (1) segment based ensemble analysis, to capture important shape transition time-steps, clusters groups of similar members, and identify common shape changes over time across multiple members; and (2) time-step based ensemble analysis, which assumes ensemble members are aligned in time by combining similar shapes at common time-steps. Both approaches enable users to interactively visualize and analyze a temporal ensemble from different perspectives at different levels of detail. We demonstrate our techniques on an ensemble studying matter transition from hadronic gas to quark-gluon plasma during gold-on-gold particle collisions.

  8. Does temporal variation of mercury levels in Arctic seabirds reflect changes in global environmental contamination, or a modification of Arctic marine food web functioning?

    PubMed

    Fort, Jérôme; Grémillet, David; Traisnel, Gwendoline; Amélineau, Françoise; Bustamante, Paco

    2016-04-01

    Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006-2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination.

  9. Evaluation of the potential of InSAR time series to study the spatio-temporal evolution of piezometric levels in the Madrid aquifer

    NASA Astrophysics Data System (ADS)

    Béjar-Pizarro, M.; Ezquerro Martín, P.; Herrera, G.; Tomás, R.; Guardiola-Albert, C.; Ruiz Hernández, J. M.; Marchamalo Sacristán, M.; Martínez Marín, R.

    2015-11-01

    The Tertiary detritic aquifer of Madrid (TDAM), with an average thickness of 1500 m and a heterogeneous, anisotropic structure, supplies water to Madrid, the most populated city of Spain (3.2 million inhabitants in the metropolitan area). Besides its complex structure, a previous work focused in the north-northwest of Madrid city showed that the aquifer behaves quasi elastically trough extraction/recovery cycles and ground uplifting during recovery periods compensates most of the ground subsidence measured during previous extraction periods (Ezquerro et al., 2014). Therefore, the relationship between ground deformation and groundwater level through time can be simulated using simple elastic models. In this work, we model the temporal evolution of the piezometric level in 19 wells of the TDAM in the period 1997-2010. Using InSAR and piezometric time series spanning the studied period, we first estimate the elastic storage coefficient (Ske) for every well. Both, the Ske of each well and the average Ske of all wells, are used to predict hydraulic heads at the different well locations during the study period and compared against the measured hydraulic heads, leading to very similar errors when using the Ske of each well and the average Ske of all wells: 14 and 16 % on average respectively. This result suggests that an average Ske can be used to estimate piezometric level variations in all the points where ground deformation has been measured by InSAR, thus allowing production of piezometric level maps for the different extraction/recovery cycles in the TDAM.

  10. The Temporal Pattern of Changes in Serum Biomarker Levels Reveals Complex and Dynamically Changing Pathologies after Exposure to a Single Low-Intensity Blast in Mice

    PubMed Central

    Ahmed, Farid; Plantman, Stefan; Cernak, Ibolja; Agoston, Denes V.

    2015-01-01

    Time-dependent changes in blood-based protein biomarkers can help identify the ­pathological processes in blast-induced traumatic brain injury (bTBI), assess injury severity, and monitor disease progression. We obtained blood from control and injured mice (exposed to a single, low-intensity blast) at 2-h, 1-day, 1–week, and 1-month post-injury. We then determined the serum levels of biomarkers related to metabolism (4-HNE, HIF-1α, ceruloplasmin), vascular function (AQP1, AQP4, VEGF, vWF, Flk-1), inflammation (OPN, CINC1, fibrinogen, MIP-1a, OX-44, p38, MMP-8, MCP-1 CCR5, CRP, galectin-1), cell adhesion and the extracellular matrix (integrin α6, TIMP1, TIMP4, Ncad, connexin-43), and axonal (NF-H, Tau), neuronal (NSE, CK-BB) and glial damage (GFAP, S100β, MBP) at various post-injury time points. Our findings indicate that the exposure to a single, low-intensity blast results in metabolic and vascular changes, altered cell adhesion, and axonal and neuronal injury in the mouse model of bTBI. Interestingly, serum levels of several inflammatory and astroglial markers were either unchanged or elevated only during the acute and subacute phases of injury. Conversely, serum levels of the majority of biomarkers related to metabolic and vascular functions, cell adhesion, as well as neuronal and axonal damage remained elevated at the termination of the experiment (1 month), indicating long-term systemic and cerebral alterations due to blast. Our findings show that the exposure to a single, low-intensity blast induces complex pathological processes with distinct temporal profiles. Hence, monitoring serum biomarker levels at various post-injury time points may provide enhanced diagnostics in blast-related neurological and multi-system deficits. PMID:26124743

  11. Temporal Predictability Facilitates Causal Learning

    ERIC Educational Resources Information Center

    Greville, W. James; Buehner, Marc J.

    2010-01-01

    "Temporal predictability" refers to the regularity or consistency of the time interval separating events. When encountering repeated instances of causes and effects, we also experience multiple cause-effect temporal intervals. Where this interval is constant it becomes possible to predict when the effect will follow from the cause. In…

  12. The temporal basis of angiogenesis

    PubMed Central

    Chakravartula, Shilpa

    2017-01-01

    The process of new blood vessel growth (angiogenesis) is highly dynamic, involving complex coordination of multiple cell types. Though the process must carefully unfold over time to generate functional, well-adapted branching networks, we seldom hear about the time-based properties of angiogenesis, despite timing being central to other areas of biology. Here, we present a novel, time-based formulation of endothelial cell behaviour during angiogenesis and discuss a flurry of our recent, integrated in silico/in vivo studies, put in context to the wider literature, which demonstrate that tissue conditions can locally adapt the timing of collective cell behaviours/decisions to grow different vascular network architectures. A growing array of seemingly unrelated ‘temporal regulators’ have recently been uncovered, including tissue derived factors (e.g. semaphorins or the high levels of VEGF found in cancer) and cellular processes (e.g. asymmetric cell division or filopodia extension) that act to alter the speed of cellular decisions to migrate. We will argue that ‘temporal adaptation’ provides a novel account of organ/disease-specific vascular morphology and reveals ‘timing’ as a new target for therapeutics. We therefore propose and explain a conceptual shift towards a ‘temporal adaptation’ perspective in vascular biology, and indeed other areas of biology where timing remains elusive. This article is part of the themed issue ‘Systems morphodynamics: understanding the development of tissue hardware’. PMID:28348255

  13. Temporal Variation and Association of Aflatoxin B₁ Albumin-Adduct Levels with Socio-Economic and Food Consumption Factors in HIV Positive Adults.

    PubMed

    Jolly, Pauline E; Akinyemiju, Tomi F; Jha, Megha; Aban, Inmaculada; Gonzalez-Falero, Andrea; Joseph, Dnika

    2015-11-30

    The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure to aflatoxin (AF) among HIV positive individuals. We examined temporal variation in AFB₁ albumin adducts (AF-ALB) in HIV positive Ghanaians, and assessed the association with socioeconomic and food consumption factors. We collected socioeconomic and food consumption data for 307 HIV positive antiretroviral naive adults and examined AF-ALB levels at recruitment (baseline) and at six (follow-up 1) and 12 (follow-up 2) months post-recruitment, by age, gender, socioeconomic status (SES) and food consumption patterns. Generalized linear models were used to examine the influence of socioeconomic and food consumption factors on changes in AF-ALB levels over the study period, adjusting for other covariates. AF-ALB levels (pg/mg albumin) were lower at baseline (mean AF-ALB: 14.9, SD: 15.9), higher at six months (mean AF-ALB: 23.3, SD: 26.6), and lower at 12 months (mean AF-ALB: 15.3, SD: 15.4). Participants with the lowest SES had the highest AF-ALB levels at baseline and follow up-2 compared with those with higher SES. Participants who bought less than 20% of their food and who stored maize for less than two months had lower AF-ALB levels. In the adjusted models, there was a statistically significant association between follow up time and season (dry or rainy season) on AF-ALB levels over time (p = 0.04). Asymptomatic HIV-positive Ghanaians had high plasma AF-ALB levels that varied according to season, socioeconomic status, and food consumption patterns. Steps need to be taken to ensure the safety and security of the food supply for the population, but in particular for the most vulnerable groups such as HIV positive people.

  14. Temporal Variation and Association of Aflatoxin B1 Albumin-Adduct Levels with Socio-Economic and Food Consumption Factors in HIV Positive Adults

    PubMed Central

    Jolly, Pauline E.; Akinyemiju, Tomi F.; Jha, Megha; Aban, Inmaculada; Gonzalez-Falero, Andrea; Joseph, Dnika

    2015-01-01

    The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure to aflatoxin (AF) among HIV positive individuals. We examined temporal variation in AFB1 albumin adducts (AF-ALB) in HIV positive Ghanaians, and assessed the association with socioeconomic and food consumption factors. We collected socioeconomic and food consumption data for 307 HIV positive antiretroviral naive adults and examined AF-ALB levels at recruitment (baseline) and at six (follow-up 1) and 12 (follow-up 2) months post-recruitment, by age, gender, socioeconomic status (SES) and food consumption patterns. Generalized linear models were used to examine the influence of socioeconomic and food consumption factors on changes in AF-ALB levels over the study period, adjusting for other covariates. AF-ALB levels (pg/mg albumin) were lower at baseline (mean AF-ALB: 14.9, SD: 15.9), higher at six months (mean AF-ALB: 23.3, SD: 26.6), and lower at 12 months (mean AF-ALB: 15.3, SD: 15.4). Participants with the lowest SES had the highest AF-ALB levels at baseline and follow up-2 compared with those with higher SES. Participants who bought less than 20% of their food and who stored maize for less than two months had lower AF-ALB levels. In the adjusted models, there was a statistically significant association between follow up time and season (dry or rainy season) on AF-ALB levels over time (p = 0.04). Asymptomatic HIV-positive Ghanaians had high plasma AF-ALB levels that varied according to season, socioeconomic status, and food consumption patterns. Steps need to be taken to ensure the safety and security of the food supply for the population, but in particular for the most vulnerable groups such as HIV positive people. PMID:26633502

  15. Multiple kernel based feature and decision level fusion of iECO individuals for explosive hazard detection in FLIR imagery

    NASA Astrophysics Data System (ADS)

    Price, Stanton R.; Murray, Bryce; Hu, Lequn; Anderson, Derek T.; Havens, Timothy C.; Luke, Robert H.; Keller, James M.

    2016-05-01

    A serious threat to civilians and soldiers is buried and above ground explosive hazards. The automatic detection of such threats is highly desired. Many methods exist for explosive hazard detection, e.g., hand-held based sensors, downward and forward looking vehicle mounted platforms, etc. In addition, multiple sensors are used to tackle this extreme problem, such as radar and infrared (IR) imagery. In this article, we explore the utility of feature and decision level fusion of learned features for forward looking explosive hazard detection in IR imagery. Specifically, we investigate different ways to fuse learned iECO features pre and post multiple kernel (MK) support vector machine (SVM) based classification. Three MK strategies are explored; fixed rule, heuristics and optimization-based. Performance is assessed in the context of receiver operating characteristic (ROC) curves on data from a U.S. Army test site that contains multiple target and clutter types, burial depths and times of day. Specifically, the results reveal two interesting things. First, the different MK strategies appear to indicate that the different iECO individuals are all more-or-less important and there is not a dominant feature. This is reinforcing as our hypothesis was that iECO provides different ways to approach target detection. Last, we observe that while optimization-based MK is mathematically appealing, i.e., it connects the learning of the fusion to the underlying classification problem we are trying to solve, it appears to be highly susceptible to over fitting and simpler, e.g., fixed rule and heuristics approaches help us realize more generalizable iECO solutions.

  16. Monitoring Tree Population Dynamics in Arid Zone Through Multiple Temporal Scales: Integration of Spatial Analysis, Change Detection and Field Long Term Monitoring

    NASA Astrophysics Data System (ADS)

    Isaacson, S.; Rachmilevitch, S.; Ephrath, J. E.; Maman, S.; Blumberg, D. G.

    2016-06-01

    High mortality rates and lack of recruitment in the acacia populations throughout the Negev Desert and the Arava rift valley of Israel have been reported in previous studies. However, it is difficult to determine whether these reports can be evidence to a significant decline trend of the trees populations. This is because of the slow dynamic processes of acaia tree populations and the lack of long term continuous monitoring data. We suggest a new data analysis technique that expands the time scope of the field long term monitoring of trees in arid environments. This will enables us to improve our understanding of the spatial and temporal changes of these populations. We implemented two different approaches in order to expand the time scope of the acacia population field survey: (1) individual based tree change detection using Corona satellite images and (2) spatial analysis of trees population, converting spatial data into temporal data. The next step was to integrate the results of the two analysis techniques (change detection and spatial analysis) with field monitoring. This technique can be implemented to other tree populations in arid environments to help assess the vegetation conditions and dynamics of those ecosystems.

  17. Evaluation of TNF-α serum level in patients with recalcitrant multiple common warts, treated by lipid garlic extract.

    PubMed

    Kenawy, Soha; Mohammed, Ghada Farouk; Younes, Soha; Elakhras, Atef Ibrahim

    2014-01-01

    No universal consensus about optimal modality for treating the recalcitrant multiple common warts (RMCW). The objective of the study was to evaluate the immunological mechanisms and clinical therapeutic effect of using lipid garlic extract (LGE) in the treatment of RMCW. The study included 50 patients with RMCW. They were randomly assigned into two groups: the first group (25 patients) received LGE, and the second group (25 patients) received saline as a control group. In both groups, treatments were made to single lesions, or largest wart in case of multiple lesions, until complete clearance of lesions or for a maximum of 4 weeks. Blood serum was taken at pre-study and at the fourth week to measure tumor necrosis factor alpha (TNF-α) level. A significant difference was found between the therapeutic responses of RMCW to LGE antigen and saline control group (p < 0.001). In the LGE group, complete response was achieved in 96% of patients presenting with RMCW. There was a statistically nonsignificant increase in TNF-α of LGE group versus saline group. No recurrence was observed in the LGE group. LGE as an immunotherapy is an inexpensive, effective, and safe modality with good cure rates for treatment of RMCWs, when other topical or physical therapies have failed.

  18. Bone Marrow Urokinase Plasminogen Activator Receptor Levels are Associated with the Progress of Multiple Myeloma(△).

    PubMed

    Shou, Li-Hong; Cao, Dan; Dong, Xiao-Hui; Fang, Qiu; Xu, Bao-Lian; Fei, Ju-Ping

    2016-09-20

    Objective To determine the mRNA and protein levels of urokinase plasminogen activator receptors (uPAR) in bone marrow fluid and bone marrow tissue from multiple myeloma (MM) patients and assess association of uPAR level with prognosis of MM. Methods uPAR levels in bone marrow fluid of 22 MM patients at the stable and progressive stages and 18 iron deficiency anemia patients with normal bone marrow (control) were examined by ELISA. Furthermore, uPAR expression in bone marrow tissue was investigated by RT-PCR and Western blot, respectively. The distribution of uPAR in MM cells was examined using immunofluorescence staining. The pathological changes in different stages of MM patients were studied by HE staining. Results uPAR level in bone marrow fluid of MM patients (1.52±0.32 μg/ml) was found to be higher than that in the control group (0.98±0.15 μg/ml). Interestingly, uPAR protein (0.686±0.075 vs. 0.372±0.043, P<0.05) and mRNA (2.51±0.46 vs. 4.46±1.15, P<0.05) expression levels of MM patients at the progressive stage were significantly higher than those at the stable stage. The expression of uPAR in MM bone marrow was confirmed by immunofluorescence staining. Moreover, HE staining revealed a great increased number of nucleated cells and severe impairment of hematopoietic function in the bone marrow of patients with progressive-stage myeloma. Conclusion Our study reveals that uPAR expression is positively correlated with the development and progress of MM.

  19. A New Less Invasive Technique for Multiple-Level Spontaneous Spinal Epidural Hematomas: Wash-and-Go Technique.

    PubMed

    Tanriverdi, Osman; Gungor, Abuzer; Coban, Mustafa Kemal; Okay, Onder; Kamaci, Umit

    2017-03-01

    Aim Spinal epidural hematomas are rare entity in neurosurgery practice. Most of them are spontaneous due to anticoagulant therapy and called spontaneous spinal epidural hematomas (SSEHs). Laminectomy or hemilaminectomy for affected levels is still the first choice in the operative treatment of an SSEH. We describe a new less invasive surgical technique, performing single-level laminectomy and washing with 0.9% sodium chloride through a thin soft catheter for a 12-level thoracic-cervical SSEH in a patient under anticoagulant therapy. Patient and Operative Technique A 55-year-old woman was brought to the emergency department with a rapid onset of pain in her upper back and both legs with weakness of her lower extremities. An urgent magnetic resonance imaging (MRI) of the whole spine showed a SEH. During the operation, after T2 laminectomy, a thin soft catheter was epidurally placed under the T1 lamina and gently pushed forward rostrally. Then continuous saline irrigation was utilized and aspiration made via the catheter to wash out the hematoma. Drainage of blood was observed. The procedure was performed for 15 minutes. Then the catheter was epidurally placed under the T3 lamina, and the procedure for the hematoma in the lower segment was repeated. Decompression of spinal cord and nerve roots was observed. Result Postoperative early MRI of the thoracic-cervical spine showed gross total evacuation of the SEH. Accordingly, the patient's muscle strength improved. Conclusion Although multiple laminectomy or hemilaminectomy for affected levels to evacuate the hematoma and decompress the spinal cord is the main choice of surgical treatment, single-level laminectomy and irrigation plus aspiration via a thin soft catheter can be performed successfully with good results in SSEH.

  20. An internal ribosome entry site (IRES) mutant library for tuning expression level of multiple genes in mammalian cells.

    PubMed

    Koh, Esther Y C; Ho, Steven C L; Mariati; Song, Zhiwei; Bi, Xuezhi; Bardor, Muriel; Yang, Yuansheng

    2013-01-01

    A set of mutated Encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) elements with varying strengths is generated by mutating the translation initiation codons of 10(th), 11(th), and 12(th) AUG to non-AUG triplets. They are able to control the relative expression of multiple genes over a wide range in mammalian cells in both transient and stable transfections. The relative strength of each IRES mutant remains similar in different mammalian cell lines and is not gene specific. The expressed proteins have correct molecular weights. Optimization of light chain over heavy chain expression by these IRES mutants enhances monoclonal antibody expression level and quality in stable transfections. Uses of this set of IRES mutants can be extended to other applications such as synthetic biology, investigating interactions between proteins and its complexes, cell engineering, multi-subunit protein production, gene therapy, and reprogramming of somatic cells into stem cells.

  1. The increased level of COX-dependent arachidonic acid metabolism in blood platelets from secondary progressive multiple sclerosis patients.

    PubMed

    Morel, Agnieszka; Miller, Elzbieta; Bijak, Michal; Saluk, Joanna

    2016-09-01

    Platelet activation is increasingly postulated as a possible component of the pathogenesis of multiple sclerosis (MS), especially due to the increased risk of cardiovascular events in MS. Arachidonic acid cascade metabolized by cyclooxygenase (COX) is a key pathway of platelet activation. The aim of our study was to investigate the COX-dependent arachidonic acid metabolic pathway in blood platelets from secondary progressive multiple sclerosis (SP MS) patients. The blood samples were obtained from 50 patients (man n = 22; female n = 28), suffering from SP MS, diagnosed according to the revised McDonald criteria. Platelet aggregation was measured in platelet-rich plasma after arachidonic acid stimulation. The level of COX activity and thromboxane B2 concentration were determined by ELISA method. Lipid peroxidation was assessed by measuring the level of malondialdehyde. The results were compared with a control group of healthy volunteers. We found that blood platelets obtained from SP MS patients were more sensitive to arachidonic acid and their response measured as platelet aggregation was stronger (about 14 %) relative to control. We also observed a significantly increased activity of COX (about 40 %) and synthesis of thromboxane B2 (about 113 %). The generation of malondialdehyde as a marker of lipid peroxidation was about 10 % higher in SP MS than in control. Cyclooxygenase-dependent arachidonic acid metabolism is significantly increased in blood platelets of patients with SP MS. Future clinical studies are required to recommend the use of low-dose aspirin, and possibly other COX inhibitors in the prevention of cardiovascular risk in MS.

  2. The limits of applicability of the sound exposure level (SEL) metric to temporal threshold shifts (TTS) in beluga whales, Delphinapterus leucas.

    PubMed

    Popov, Vladimir V; Supin, Alexander Ya; Rozhnov, Viatcheslav V; Nechaev, Dmitry I; Sysueva, Evgenia V

    2014-05-15

    The influence of fatiguing sound level and duration on post-exposure temporary threshold shift (TTS) was investigated in two beluga whales (Delphinapterus leucas). The fatiguing sound was half-octave noise with a center frequency of 22.5 kHz. TTS was measured at a test frequency of 32 kHz. Thresholds were measured by recording rhythmic evoked potentials (the envelope following response) to a test series of short (eight cycles) tone pips with a pip rate of 1000 s(-1). TTS increased approximately proportionally to the dB measure of both sound pressure (sound pressure level, SPL) and duration of the fatiguing noise, as a product of these two variables. In particular, when the noise parameters varied in a manner that maintained the product of squared sound pressure and time (sound exposure level, SEL, which is equivalent to the overall noise energy) at a constant level, TTS was not constant. Keeping SEL constant, the highest TTS appeared at an intermediate ratio of SPL to sound duration and decreased at both higher and lower ratios. Multiplication (SPL multiplied by log duration) better described the experimental data than an equal-energy (equal SEL) model. The use of SEL as a sole universal metric may result in an implausible assessment of the impact of a fatiguing sound on hearing thresholds in odontocetes, including under-evaluation of potential risks.

  3. Spatial and temporal variation in carbon deposition in a Galveston, Texas salt marsh: The role of elevation and relative sea level history

    NASA Astrophysics Data System (ADS)

    Kulawardhana, R. W.; Feagin, R. A.; Popescu, S. C.

    2013-12-01

    Coastal wetlands, including salt marshes, are considered to be large carbon sinks. Yet, there is little knowledge about how the terrain and land cover of these environments are related to carbon distribution. An understanding of the spatial and temporal patterns of carbon held in both the biomass and soil, and the factors that influence its distribution, will be necessary to allow coastal managers to initiate and verify 'Blue Carbon' projects. Through the use of extensive field sampling and remote sensing data (lidar and aerial images), we sought to map and explain how vegetation biomass and soil carbon are related to elevation and relative sea level change in a Spartina alterniflora dominated salt marsh in Galveston, Texas. The specific objectives of this study were to: 1) understand the relationship between elevation and the distribution of salt marsh vegetation percent cover, plant height, plant density, above-ground biomass, and root biomass; and 2) understand the relationship between elevation and patterns of soil carbon across different depths of the soil profile; and 3) to evaluate how relative water level governs the spatial and temporal variability of salt marsh carbon. Our results indicate a clear zonation of vegetation as a function of terrain. Plant height, culm/ stem height and the percent cover measurements showed significant differences (p=0.05) across three elevation zones defined as 0- 30cm, 30-40cm, and >40cm. Live biomass, plant height, and culm height decreased as elevation increased, while plant density followed the opposite pattern. Dead biomass accumulation increased with increasing elevation. Soil carbon was measured in the soil profile, revealing a gradual depletion of soil carbon with depth. However, both the soil bulk density and the percent carbon indicated an abrupt and significant change at a depth of 15cm (p=0.05), which we interpreted as distinct of two different environments. As evidenced by historical aerial imagery (1954, 1969

  4. Temporal dynamics of the developing lung transcriptome in three common inbred strains of laboratory mice reveals multiple stages of postnatal alveolar development

    PubMed Central

    Beauchemin, Kyle J.; Wells, Julie M.; Kho, Alvin T.; Philip, Vivek M.; Kamir, Daniela; Kohane, Isaac S.

    2016-01-01

    To characterize temporal patterns of transcriptional activity during normal lung development, we generated genome wide gene expression data for 26 pre- and post-natal time points in three common inbred strains of laboratory mice (C57BL/6J, A/J, and C3H/HeJ). Using Principal Component Analysis and least squares regression modeling, we identified both strain-independent and strain-dependent patterns of gene expression. The 4,683 genes contributing to the strain-independent expression patterns were used to define a murine Developing Lung Characteristic Subtranscriptome (mDLCS). Regression modeling of the Principal Components supported the four canonical stages of mammalian embryonic lung development (embryonic, pseudoglandular, canalicular, saccular) defined previously by morphology and histology. For postnatal alveolar development, the regression model was consistent with four stages of alveolarization characterized by episodic transcriptional activity of genes related to pulmonary vascularization. Genes expressed in a strain-dependent manner were enriched for annotations related to neurogenesis, extracellular matrix organization, and Wnt signaling. Finally, a comparison of mouse and human transcriptomics from pre-natal stages of lung development revealed conservation of pathways associated with cell cycle, axon guidance, immune function, and metabolism as well as organism-specific expression of genes associated with extracellular matrix organization and protein modification. The mouse lung development transcriptome data generated for this study serves as a unique reference set to identify genes and pathways essential for normal mammalian lung development and for investigations into the developmental origins of respiratory disease and cancer. The gene expression data are available from the Gene Expression Omnibus (GEO) archive (GSE74243). Temporal expression patterns of mouse genes can be investigated using a study specific web resource (http

  5. Temporal variations in sirtuin expression under normal and ultraviolet B-induced conditions and their correlation to energy levels in normal human epidermal keratinocytes.

    PubMed

    Pelle, Edward; Dong, Kelly; Pernodet, Nadine

    2015-01-01

    Sirtuins are post-translational modifiers that affect transcriptional signaling, metabolism, and DNA repair. Although originally identified as gene silencers capable of extending cell lifespan, the involvement of sirtuins in many different areas of cell biology has now become widespread. Our approach has been to study the temporal variation and also the effect of environmental stressors, such as ultraviolet B (UVB) and ozone, on sirtuin expression in human epidermal keratinocytes. In this report, we measured the variation in expression of several sirtuins over time and also show how a low dose of UVB can affect this pattern of expression. Moreover, we correlated these changes to variations in hydrogen peroxide (H2O2) and ATP levels. Our data show significant variations in normal sirtuin expression, which may indicate a generalized response by sirtuins to cell cycle kinetics. These results also demonstrate that sirtuins as a family of molecules are sensitive to UVB-induced disruption and may suggest a new paradigm for determining environmental stress on aging and provide direction for the development of new cosmetic products.

  6. Temporal Trends of the Clinical, Resource Use and Outcome Attributes of ICU-Managed Candidemia Hospitalizations: A Population-Level Analysis

    PubMed Central

    Oud, Lavi

    2016-01-01

    Background There are mixed findings on the longitudinal patterns of the incidence of intensive care unit (ICU)-managed candidemia, with scarcity of reports on the corresponding evolving patterns of patients’ clinical characteristics and outcomes. No population-level data were reported on the temporal trends of the attributes, care and outcomes of ICU-managed adults with candidemia. Methods The Texas Inpatient Public Use Data File was used to identify hospitalizations aged 18 years or older with a diagnosis of candidemia and ICU admission (C-ICU hospitalizations) between 2001 and 2010. Temporal trends of the demographics, clinical features, use of healthcare resources, and short-term outcomes were examined. Average annual percent changes (AAPCs) were derived. Results C-ICU hospitalizations (n = 7,552) became (AAPC) increasingly younger (age ≥ 65 years: -1.0%/year). The Charslon comorbidity index rose 4.2%/year, while the mean number of organ failures (OFs) increased by 8.2%/year, with a fast rise in the rate of those developing ≥ 3 OFs (+15.5%/year). Between 2001 and 2010, there was no significant change in utilization of mechanical ventilation and new hemodialysis among C-ICU hospitalizations with reported respiratory and renal failures (68.9% vs. 73.3%, P = 0.3653 and 15.5% vs. 21.8%, P = 0.8589, respectively). Hospital length of stay or total hospital charges remained unchanged during study period. Hospital mortality decreased between 2001 and 2010 from 39.3% to 23.8% (-5.2%/year). The majority of hospital survivors (61.6%) were discharged to another facility, and increasingly to long-term acute care hospitals, with routine home discharge decreasing to 11% by 2010. Conclusions C-ICU hospitalizations demonstrated increasing comorbidity burden and rising development of OF, and matching rise in use of selected life-support interventions, though with unchanged in-hospital fiscal impact. There has been marked decrease in hospital mortality, but survivors had

  7. Levels and temporal trends (1988-1999) of polybrominated diphenyl ethers in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Canada.

    PubMed

    Lebeuf, Michel; Gouteux, Bruno; Measures, Lena; Trottier, Steve

    2004-06-01

    Polybrominated diphenyl ethers (PBDEs) were determined in blubber samples of 54 stranded adult beluga whales (Delphinapterus leucas) collected between 1988 and 1999 in the St. Lawrence Estuary (SLE), Quebec, Canada. Summed concentrations of 10 PBDE congeners (sigmaPBDEs) measured in beluga samples varied between 20 and almost 1000 ng/g wet weight. According to the PBDE concentrations in marine mammals reported in the scientific literature, SLE belugas appear to be relatively lightly contaminated. Only a few predominant congeners (namely, PBDE-47, -99, and -100) represent on average more than 75% of sigmaPBDEs in SLE belugas. The accumulation of sigmaPBDEs in both male and female belugas showed significant exponential increase throughout the 1988-1999 time period. The time necessary for beluga to double their blubber concentration of the most prevalent PBDE congeners was no longer than 3 years. The PBDE temporal changes reported in this study are generally faster but in agreement with the trend observed in other organisms collected in Canada, such as lake trout (Salvelinus namaycush) from the Great Lakes, ringed seal (Phoca hispida), and beluga whale from the Canadian Arctic. Some changes in the pattern of PBDEs in belugas were also observed during the time period investigated. The recent and important increase of PBDE levels in SLE belugas could explain the unexpected lack of statistical difference in PBDE contamination between males and females. This suggests that to date PBDEs tend to be accumulated by both male and female belugas, masking the elimination of PBDEs by females through post-natal transfer to their offspring. This study confirms that the growing use of PBDEs as flame retardants has resulted in rising contamination of Canadian aquatic environments. Additional studies are needed to assess the toxicological implications of the PBDE tissue levels found in SLE belugas.

  8. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate

    PubMed Central

    Johnston, James D.; Tuttle, Steven C.; Nelson, Morgan C.; Bradshaw, Rebecca K.; Hoybjerg, Taylor G.; Johnson, Julene B.; Kruman, Bryce A.; Orton, Taylor S.; Cook, Ryan B.; Eggett, Dennis L.; Weber, K. Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan–Apr) and summer (July–Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction. PMID:26808528

  9. Effects of treated sewage sludge levels on temporal variations of some soil properties of a Typic Xerofluvent soil in Menemen Plain, Western Anatolia, Turkey.

    PubMed

    Delibacak, S; Okur, B; Ongun, A R

    2009-01-01

    The aim of this study is to determine effects of treated sewage sludge (TSS) levels as an organic matter (OM) resource on temporal variations of some soil properties of a Typic Xerofluvent soil. The experiment was conducted in Menemen Plain, in the Western Anatolia Region of Turkey (latitudes 38 degrees 34'48.22''-38 degrees 34'49.24'' N; longitudes 27 degrees 1'23.05-27 degrees 1'24.14'' E) in the years of 2003 and 2004. Moist TSS was added to the soil at the rates of 0, 30, 60 and 90 t ha(-1) on May 1, 2003. Peanut (Arachis hypogaea) was planted as first crop. On the other hand, mixture of green barley (Hordeum vulgare) and common vetch (Vicia sativa L.) was planted as second crop. During the experiment, soil samples were taken in five different periods (1st, June 18, 2003; 2nd, November 13, 2003; 3rd, April 30, 2004; 4th, October 10, 2004 and 5th, May 12, 2004). The results showed that increasing TSS application to Typic Xerofluvent soil was significantly increased total salt, OM, total porosity, micro porosity, macro porosity, field capacity, wilting point, available water content, structure stability index and aggregation percentage values of soil when compared with control. Meanwhile, particle density, dry bulk density and nonaggregated silt + clay values of soil decreased. On the other hand, soil reaction (pH), lime content and total silt + clay values of soil did not significantly change. In the course of time, depending on decomposing of TSS organic materials in soil, effect of TSS levels on soil properties decreased particularly in the last periods. For this reason, it can be recommended that 90 t ha(-1) moist TSS can be added once in 2 years for improving soil properties of Typic Xerofluvent soil, which are characterized by low OM content.

  10. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    PubMed

    Johnston, James D; Tuttle, Steven C; Nelson, Morgan C; Bradshaw, Rebecca K; Hoybjerg, Taylor G; Johnson, Julene B; Kruman, Bryce A; Orton, Taylor S; Cook, Ryan B; Eggett, Dennis L; Weber, K Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

  11. Preserved levels of uninvolved immunoglobulins are independently associated with favorable outcome in patients with symptomatic multiple myeloma.

    PubMed

    Kastritis, E; Zagouri, F; Symeonidis, A; Roussou, M; Sioni, A; Pouli, A; Delimpasi, S; Katodritou, E; Michalis, E; Michael, M; Hatzimichael, E; Vassou, A; Repousis, P; Christophoridou, A; Kartasis, Z; Stefanoudaki, E; Megalakaki, C; Giannouli, S; Kyrtsonis, M-C; Konstantopoulos, K; Spyroupoulou-Vlachou, M; Terpos, E; Dimopoulos, M A

    2014-10-01

    Suppression of uninvolved immunoglobulins is common in multiple myeloma (MM) but the prognostic significance of this phenomenon has not been assessed. We evaluated the prognostic significance of the preservation of uninvolved immunoglobulins in 1755 consecutive, unselected, patients with newly diagnosed, symptomatic MM with pre-therapy immunoglobulin levels measured by nephelometry. Suppression of at least one uninvolved immunoglobulin was observed in 87% of patients and was more common in patients with immunoglobulin A myeloma, those aged over 65 years, in patients with advanced-International Staging System (ISS) stage, extensive-bone marrow infiltration, anemia, low platelet counts, high levels of serum M-monoclonal protein or renal dysfunction. Patients with preserved immunoglobulins had a better survival than patients with suppressed immunoglobulins (median survival 55 vs 41.5 months, P<0.001). In multivariate analysis, preservation of uninvolved immunoglobulins was independently associated with better survival (hazard ratio: 0.781, 95% confidence interval: 0.618-0.987, P=0.039); irrespective of the treatment. In a subset of 500 patients, which were strictly followed for disease progression, preservation of uninvolved immunoglobulins was associated with a significantly longer progression-free survival (60 vs 25 months, P<0.001), independently of other common prognostic factors. In conclusion, preservation of uninvolved immunoglobulins in newly diagnosed patients with symptomatic MM was independently associated with long term disease control and improved survival.

  12. Modeling the reliability of a class of fault-tolerant VLSI/WSI systems based on multiple-level redundancy

    NASA Astrophysics Data System (ADS)

    Chen, Yung-Yuan; Upadhyaya, Shambhu J.

    1994-06-01

    A class of fault-tolerant Very Large Scale Integration (VLSI) and Wafer Scale Integration (WSI) schemes, called the multiple-level redundancy, which incorporates both hierarchical and element level redundancy has been proposed for the design of high yield and high reliability large area array processors. The residual redundancy left unused after successfully reconfiguring and eliminating the manufacturing defects can be used to improve the operational reliability of a system. Since existing techniques for the analysis of the effect of residual redundancy on reliability improvement are not applicable, we present a new hierarchical model to estimate the reliability of the systems designed by our approach. Our model emphasizes the effect of support circuit (interconnection) failures on system reliability, leading to more accurate analysis. We discuss two area prediction models, one based on the regular WSI process, another based on the advanced WSI process, to estimate the area-related parameters. This analysis gives an insight into the practical implementations of fault-tolerant schemes in VLSI/WSI technology. Results of a computer experiment conducted to validate our models are also discussed.

  13. Temporal summaries: supporting temporal categorical searching, aggregation and comparison.

    PubMed

    Wang, Taowei David; Plaisant, Catherine; Shneiderman, Ben; Spring, Neil; Roseman, David; Marchand, Greg; Mukherjee, Vikramjit; Smith, Mark

    2009-01-01

    When analyzing thousands of event histories, analysts often want to see the events as an aggregate to detect insights and generate new hypotheses about the data. An analysis tool must emphasize both the prevalence and the temporal ordering of these events. Additionally, the analysis tool must also support flexible comparisons to allow analysts to gather visual evidence. In a previous work, we introduced align, rank, and filter (ARF) to accentuate temporal ordering. In this paper, we present temporal summaries, an interactive visualization technique that highlights the prevalence of event occurrences. Temporal summaries dynamically aggregate events in multiple granularities (year, month, week, day, hour, etc.) for the purpose of spotting trends over time and comparing several groups of records. They provide affordances for analysts to perform temporal range filters. We demonstrate the applicability of this approach in two extensive case studies with analysts who applied temporal summaries to search, filter, and look for patterns in electronic health records and academic records.

  14. Physiological Stress Responses in Amphibian Larvae to Multiple Stressors Reveal Marked Anthropogenic Effects even below Lethal Levels.

    PubMed

    Burraco, Pablo; Gomez-Mestre, Ivan

    Natural and anthropogenic disturbances cause profound alterations in organisms, inducing physiological adjustments to avoid, reduce, or remedy the impact of disturbances. In vertebrates, the stress response is regulated via neuroendocrine pathways, including the hypothalamic-pituitary-interrenal axis that regulates the secretion of glucocorticoids. Glucocorticoids have cascading effects on multiple physiological pathways, affecting the metabolic rate, reactive oxygen species production, or immune system. Determining the extent to which natural and anthropogenic environmental factors induce stress responses in vertebrates is of great importance in ecology and conservation biology. Here we study the physiological stress response in spadefoot toad tadpoles (Pelobates cultripes) against three levels of a series of natural and anthropogenic stressors common to many aquatic systems: salinity (0, 6, and 9 ppt), herbicide (0, 1, and 2 mg/L acid equivalent of glyphosate), water acidity (pH 4.5, 7.0, and 9.5), predators (absent, native, and invasive), and temperature (21°, 25°, and 29°C). The physiological stress response was assessed examining corticosterone levels, standard metabolic rate, activity of antioxidant enzymes, oxidative cellular damage in lipids, and immunological status. We found that common stressors substantially altered the physiological state of tadpoles. In particular, salinity and herbicides cause dramatic physiological changes in tadpoles. Moreover, tadpoles reduced corticosterone levels in the presence of natural predators but did not do so against invasive predators, indicating a lack of innate recognition. Corticosterone and the antioxidant enzyme glutathione reductase were the most sensitive parameters to stress in this study. Anthropogenic perturbations of aquatic systems pose serious threats to larval amphibians even at nonlethal concentrations, judging from the marked physiological stress responses generated, and reveal the importance of

  15. Mapping the Multiple Graded Contributions of the Anterior Temporal Lobe Representational Hub to Abstract and Social Concepts: Evidence from Distortion-corrected fMRI

    PubMed Central

    Binney, Richard J.; Hoffman, Paul; Lambon Ralph, Matthew A.

    2016-01-01

    A growing body of recent convergent evidence indicates that the anterior temporal lobe (ATL) has connectivity-derived graded differences in semantic function: the ventrolateral region appears to be the transmodal, omni-category center-point of the hub whilst secondary contributions come from the peripheries of the hub in a manner that reflects their differential connectivity to different input/output modalities. One of the key challenges for this neurocognitive theory is how different types of concept, especially those with less reliance upon external sensory experience (such as abstract and social concepts), are coded across the graded ATL hub. We were able to answer this key question by using distortion-corrected fMRI to detect functional activations across the entire ATL region and thus to map the neural basis of social and psycholinguistically-matched abstract concepts. Both types of concept engaged a core left-hemisphere semantic network, including the ventrolateral ATL, prefrontal regions and posterior MTG. Additionally, we replicated previous findings of weaker differential activation of the superior and polar ATL for the processing of social stimuli, in addition to the stronger, omni-category activation observed in the vATL. These results are compatible with the view of the ATL as a graded transmodal substrate for the representation of coherent concepts. PMID:27600844

  16. Mapping the Multiple Graded Contributions of the Anterior Temporal Lobe Representational Hub to Abstract and Social Concepts: Evidence from Distortion-corrected fMRI.

    PubMed

    Binney, Richard J; Hoffman, Paul; Lambon Ralph, Matthew A

    2016-09-06

    A growing body of recent convergent evidence indicates that the anterior temporal lobe (ATL) has connectivity-derived graded differences in semantic function: the ventrolateral region appears to be the transmodal, omni-category center-point of the hub whilst secondary contributions come from the peripheries of the hub in a manner that reflects their differential connectivity to different input/output modalities. One of the key challenges for this neurocognitive theory is how different types of concept, especially those with less reliance upon external sensory experience (such as abstract and social concepts), are coded across the graded ATL hub. We were able to answer this key question by using distortion-corrected fMRI to detect functional activations across the entire ATL region and thus to map the neural basis of social and psycholinguistically-matched abstract concepts. Both types of concept engaged a core left-hemisphere semantic network, including the ventrolateral ATL, prefrontal regions and posterior MTG. Additionally, we replicated previous findings of weaker differential activation of the superior and polar ATL for the processing of social stimuli, in addition to the stronger, omni-category activation observed in the vATL. These results are compatible with the view of the ATL as a graded transmodal substrate for the representation of coherent concepts.

  17. Multiple single-point imaging (mSPI) as a tool for capturing and characterizing MR signals and repetitive signal disturbances with high temporal resolution: the MRI scanner as a high-speed camera.

    PubMed

    Bakker, Chris J G; van Gorp, Jetse S; Verwoerd, Jan L; Westra, Albert H; Bouwman, Job G; Zijlstra, Frank; Seevinck, Peter R

    2013-09-01

    In this paper we aim to lay down and demonstrate the use of multiple single-point imaging (mSPI) as a tool for capturing and characterizing steady-state MR signals and repetitive disturbances thereof with high temporal resolution. To achieve this goal, various 2D mSPI sequences were derived from the nearest standard 3D imaging sequences by (i) replacing the excitation of a 3D slab by the excitation of a 2D slice orthogonal to the read axis, (ii) setting the readout gradient to zero, and (iii) leaving out the inverse Fourier transform in the read direction. The thus created mSPI sequences, albeit slow with regard to the spatial encoding part, were shown to result into a series of densely spaced 2D single-point images in the time domain enabling monitoring of the evolution of the magnetization with a high temporal resolution and without interference from any encoding gradients. The high-speed capabilities of mSPI were demonstrated by capturing and characterizing the free induction decays and spin echoes of substances with long T2s (>30 ms) and long and short T2*s (4 - >30 ms) and by monitoring the perturbation of the transverse magnetization by, respectively, a titanium cylinder, representing a static disturbance; a pulsed magnetic field gradient, representing a stimulus inherent to a conventional MRI experiment; and a pulsed electric current, representing an external stimulus. The results of the study indicate the potential of mSPI for assessing the evolution of the magnetization and, when properly synchronized with the acquisition, repeatable disturbances thereof with a temporal resolution that is ultimately limited by the bandwidth of the receiver, but in practice governed by the SNR of the experiment and the magnitude of the disturbance. Potential applications of mSPI can be envisaged in research areas that are concerned with MR signal behavior, MR system performance and MR evaluation of magnetically evoked responses.

  18. Levels and temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard in relation to dietary habits and food availability.

    PubMed

    Andersen, Martin S; Fuglei, Eva; König, Max; Lipasti, Inka; Pedersen, Åshild Ø; Polder, Anuschka; Yoccoz, Nigel G; Routti, Heli

    2015-04-01

    Temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard, Norway, were investigated in relation to feeding habits and seasonal food availability. Arctic foxes from Svalbard forage in both marine and terrestrial ecosystems and the availability of their food items are impacted by climatic variability. Concentrations of polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and brominated flame retardants (polybrominated diphenyl ethers [PBDEs] and hexabromocyclododecane [HBCDD]) were analyzed in the liver of 141 arctic foxes collected between 1997 and 2013. Stable carbon isotope values (δ13C) were used as a proxy for feeding on marine versus terrestrial prey. The annual number of recovered reindeer carcasses and sea ice cover were used as proxies for climate influenced food availability (reindeers, seals). Linear models revealed that concentrations of PCBs, chlordanes, p,p'-DDE, mirex and PBDEs decreased 4-11% per year, while no trends were observed for hexachlorobenzene (HCB) or β-hexachlorocyclohexane (β-HCH). Positive relationships between POP concentrations and δ13C indicate that concentrations of all compounds increase with increasing marine dietary input. Increasing reindeer mortality was related to lower HCB concentrations in the foxes based on the linear models. This suggests that concentrations of HCB in arctic foxes may be influenced by high mortality levels of Svalbard reindeer. Further, β-HCH concentrations showed a positive association with sea ice cover. These results in addition to the strong effect of δ13C on all POP concentrations suggest that climate-related changes in arctic fox diet are likely to influence contaminant concentrations in arctic foxes from Svalbard.

  19. Signaling stress? An analysis of phaeomelanin-based plumage color and individual corticosterone levels at two temporal scales in North American barn swallows, Hirundo rustica erythrogaster.

    PubMed

    Jenkins, Brittany R; Vitousek, Maren N; Safran, Rebecca J

    2013-09-01

    Sexually selected traits confer greater reproductive benefits to individuals with more elaborate forms of the signal. However, whether these signals convey reliable information about the physiology underlying trait development remains unknown in many species. The steroid hormone corticosterone (CORT) mediates important physiological and behavioral processes during the vertebrate stress response, and CORT secretion itself can be modulated by melanocortins. Thus, sexually selected melanin-based plumage coloration could function as an honest signal of an individual's ability to respond to stressors. This hypothesis was tested in North American barn swallows, Hirundo rustica erythrogaster, where males with darker ventral plumage color exhibit higher phaeomelanin content and are more successful at reproduction. Because reproductive behavior occurs months after plumage signals are developed, we also addressed the potential temporal disconnect of physiological state during trait development and trait advertisement by analyzing three different measurements of CORT levels in adult males during the breeding season (trait advertisement) and in nestling males while they were growing their feathers (trait development). Variation in adult plumage color did not predict baseline or stress-induced CORT, or stress responsiveness. Likewise, there was no relationship between nestling plumage color and any of the CORT measurements, but heavier nestlings had significantly lower baseline CORT. Our finding that a predominantly phaeomelanin-based trait is unrelated to circulating CORT suggests that phaeomelanin and eumelanin signals may convey different physiological information, and highlights the need for further study on the biochemical links between the hypothalamic-pituitary-adrenal (HPA) axis and the production of different melanin-based pigments.

  20. Temporal Characterization of Hydrates System Dynamics beneath Seafloor Mounds. Integrating Time-Lapse Electrical Resistivity Methods and In Situ Observations of Multiple Oceanographic Parameters

    SciTech Connect

    Lutken, Carol; Macelloni, Leonardo; D'Emidio, Marco; Dunbar, John; Higley, Paul

    2015-01-31

    This study was designed to investigate temporal variations in hydrate system dynamics by measuring changes in volumes of hydrate beneath hydrate-bearing mounds on the continental slope of the northern Gulf of Mexico, the landward extreme of hydrate occurrence in this region. Direct Current Resistivity (DCR) measurements were made contemporaneously with measurements of oceanographic parameters at Woolsey Mound, a carbonate-hydrate complex on the mid-continental slope, where formation and dissociation of hydrates are most vulnerable to variations in oceanographic parameters affected by climate change, and where changes in hydrate stability can readily translate to loss of seafloor stability, impacts to benthic ecosystems, and venting of greenhouse gases to the water-column, and eventually, the atmosphere. We focused our study on hydrate within seafloor mounds because the structurally-focused methane flux at these sites likely causes hydrate formation and dissociation processes to occur at higher rates than at sites where the methane flux is less concentrated and we wanted to maximize our chances of witnessing association/dissociation of hydrates. We selected a particularly well-studied hydrate-bearing seafloor mound near the landward extent of the hydrate stability zone, Woolsey Mound (MC118). This mid-slope site has been studied extensively and the project was able to leverage considerable resources from the team’s research experience at MC118. The site exhibits seafloor features associated with gas expulsion, hydrates have been documented at the seafloor, and changes in the outcropping hydrates have been documented, photographically, to have occurred over a period of months. We conducted observatory-based, in situ measurements to 1) characterize, geophysically, the sub-bottom distribution of hydrate and its temporal variability, and 2) contemporaneously record relevant environmental parameters (temperature, pressure, salinity, turbidity, bottom currents) to

  1. A hybrid semi-automatic method for liver segmentation based on level-set methods using multiple seed points.

    PubMed

    Yang, Xiaopeng; Yu, Hee Chul; Choi, Younggeun; Lee, Wonsup; Wang, Baojian; Yang, Jaedo; Hwang, Hongpil; Kim, Ji Hyun; Song, Jisoo; Cho, Baik Hwan; You, Heecheon

    2014-01-01

    The present study developed a hybrid semi-automatic method to extract the liver from abdominal computerized tomography (CT) images. The proposed hybrid method consists of a customized fast-marching level-set method for detection of an optimal initial liver region from multiple seed points selected by the user and a threshold-based level-set method for extraction of the actual liver region based on the initial liver region. The performance of the hybrid method was compared with those of the 2D region growing method implemented in OsiriX using abdominal CT datasets of 15 patients. The hybrid method showed a significantly higher accuracy in liver extraction (similarity index, SI=97.6 ± 0.5%; false positive error, FPE = 2.2 ± 0.7%; false negative error, FNE=2.5 ± 0.8%; average symmetric surface distance, ASD=1.4 ± 0.5mm) than the 2D (SI=94.0 ± 1.9%; FPE = 5.3 ± 1.1%; FNE=6.5 ± 3.7%; ASD=6.7 ± 3.8mm) region growing method. The total liver extraction time per CT dataset of the hybrid method (77 ± 10 s) is significantly less than the 2D region growing method (575 ± 136 s). The interaction time per CT dataset between the user and a computer of the hybrid method (28 ± 4 s) is significantly shorter than the 2D region growing method (484 ± 126 s). The proposed hybrid method was found preferred for liver segmentation in preoperative virtual liver surgery planning.

  2. Seasonal variations of 25-OH vitamin D serum levels are associated with clinical disease activity in multiple sclerosis patients.

    PubMed

    Hartl, Christina; Obermeier, Viola; Gerdes, Lisa Ann; Brügel, Mathias; von Kries, Rüdiger; Kümpfel, Tania

    2017-04-15

    Low 25-hydroxy vitamin D (25-[OH]-D) serum concentrations have been associated with higher disease activity in multiple sclerosis (MS) patients. In a large cross-sectional study we assessed the vitamin D status in MS patients in relation to seasonality and relapse rate. 415 MS-patients (355 relapsing-remitting MS and 60 secondary-progressive, 282 female, mean age 39.1years) of whom 25-(OH)-D serum concentrations were determined at visits between 2010 and 2013 were included in the study. All clinical data including relapse at visit and expanded disability status scale were recorded in a standardized manner by an experienced neurologist. Seasonal variations of 25-(OH)-D serum concentrations were modelled by sinusoidal regression and seasonal variability in the prevalence of relapse by cubic regression. The mean 25-(OH)-D serum concentration was 24.8ng/ml (range 8.3-140ng/ml) with peak levels of 32.2ng/ml in July/August and nadir in January/February (17.2ng/ml). The lowest modelled prevalence of relapse was in September/October (28%) and the highest modelled prevalence in March/April (47%). The nadir of 25-(OH)-D serum concentrations preceded the peak in prevalence of relapses by two months. In summary, seasonal variation of 25-(OH)-D serum levels were inversely associated with clinical disease activity in MS patients. Future studies should investigate whether vitamin D supplementation in MS patients may decrease the seasonal risk for MS relapses.

  3. Enhanced high-level Petri nets with multiple colors for knowledge verification/validation of rule-based expert systems.

    PubMed

    Wu, C H; Lee, S J

    1997-01-01

    Exploring the properties of rule-based expert systems through Petri net models has received a lot of attention. Traditional Petri nets provide a straightforward but inadequate method for knowledge verification/validation of rule-based expert systems. We propose an enhanced high-level Petri net model in which variables and negative information can be represented and processed properly. Rule inference is modeled exactly and some important aspects in rule-based systems (RBSs), such as conservation of facts, refraction, and closed-world assumption, are considered in this model. With the coloring scheme proposed in this paper, the tasks involved in checking the logic structure and output correctness of an RES are formally investigated. We focus on the detection of redundancy, conflicts, cycles, unnecessary conditions, dead ends, and unreachable goals in an RES. These knowledge verification/validation (KVV) tasks are formulated as the reachability problem and improper knowledge can be detected by solving a set of equations with respect to multiple colors. The complexity of our method is discussed and a comparison of our model with other Petri net models is presented.

  4. The Synthetic Immunomodulator Murabutide Controls Human Immunodeficiency Virus Type 1 Replication at Multiple Levels in Macrophages and Dendritic Cells

    PubMed Central

    Darcissac, Edith C. A.; Truong, Marie-José; Dewulf, Joëlle; Mouton, Yves; Capron, André; Bahr, George M.

    2000-01-01

    Macrophages and dendritic cells are known to play an important role in the establishment and persistence of human immunodeficiency virus (HIV) infection. Besides antiretroviral therapy, several immune-based interventions are being evaluated with the aim of achieving better control of virus replication in reservoir cells. Murabutide is a safe synthetic immunomodulator presenting a capacity to enhance nonspecific resistance against viral infections and to target cells of the reticuloendothelial system. In this study, we have examined the ability of Murabutide to control HIV type 1 (HIV-1) replication in acutely infected monocyte-derived macrophages (MDMs) and dendritic cells (MDDCs). Highly significant suppression of viral replication was consistently observed in Murabutide-treated cultures of both cell types. Murabutide did not affect virus entry, reverse transcriptase activity, or early proviral DNA formation in the cytoplasm of infected cells. However, treated MDMs and MDDCs showed a dramatic reduction in nuclear viral two-long terminal repeat circular form and viral mRNA transcripts. This HIV-1-suppressive activity was not mediated by inhibiting cellular DNA synthesis or by activating p38 mitogen-activated protein kinase. Furthermore, Murabutide-stimulated cells expressed reduced CD4 and CCR5 receptors and secreted high levels of β-chemokines, although neutralization of the released chemokines did not alter the HIV-1-suppressive activity of Murabutide. These results provide evidence that a clinically acceptable immunomodulator can activate multiple effector pathways in macrophages and in dendritic cells, rendering them nonpermissive for HIV-1 replication. PMID:10933686

  5. Intra-urban spatial variability in wintertime street-level concentrations of multiple combustion-related air pollutants: the New York City Community Air Survey (NYCCAS).

    PubMed

    Clougherty, Jane E; Kheirbek, Iyad; Eisl, Holger M; Ross, Zev; Pezeshki, Grant; Gorczynski, John E; Johnson, Sarah; Markowitz, Steven; Kass, Daniel; Matte, Thomas

    2013-01-01

    Although intra-urban air pollution differs by season, few monitoring networks provide adequate geographic density and year-round coverage to fully characterize seasonal patterns. Here, we report winter intra-urban monitoring and land-use regression (LUR) results from the New York City Community Air Survey (NYCCAS). Two-week integrated samples of fine particles (PM(2.5)), black carbon (BC), nitrogen oxides (NO(x)) and sulfur dioxide (SO(2)) were collected at 155 city-wide street-level locations during winter 2008-2009. Sites were selected using stratified random sampling, randomized across sampling sessions to minimize spatio-temporal confounding. LUR was used to identify GIS-based source indicators associated with higher concentrations. Prediction surfaces were produced using kriging with external drift. Each pollutant varied twofold or more across sites, with higher concentrations near midtown Manhattan. All pollutants were positively correlated, particularly PM(2.5) and BC (Spearman's r=0.84). Density of oil-burning boilers, total and truck traffic density, and temporality explained 84% of PM(2.5) variation. Densities of total traffic, truck traffic, oil-burning boilers and industrial space, with temporality, explained 65% of BC variation. Temporality, built space, bus route location, and traffic density described 67% of nitrogen dioxide variation. Residual oil-burning units, nighttime population and temporality explained 77% of SO(2) variation. Spatial variation in combustion-related pollutants in New York City was strongly associated with oil-burning and traffic density. Chronic exposure disparities and unique local sources can be identified through year-round saturation monitoring.

  6. Temporal networks

    NASA Astrophysics Data System (ADS)

    Holme, Petter; Saramäki, Jari

    2012-10-01

    A great variety of systems in nature, society and technology-from the web of sexual contacts to the Internet, from the nervous system to power grids-can be modeled as graphs of vertices coupled by edges. The network structure, describing how the graph is wired, helps us understand, predict and optimize the behavior of dynamical systems. In many cases, however, the edges are not continuously active. As an example, in networks of communication via e-mail, text messages, or phone calls, edges represent sequences of instantaneous or practically instantaneous contacts. In some cases, edges are active for non-negligible periods of time: e.g., the proximity patterns of inpatients at hospitals can be represented by a graph where an edge between two individuals is on throughout the time they are at the same ward. Like network topology, the temporal structure of edge activations can affect dynamics of systems interacting through the network, from disease contagion on the network of patients to information diffusion over an e-mail network. In this review, we present the emergent field of temporal networks, and discuss methods for analyzing topological and temporal structure and models for elucidating their relation to the behavior of dynamical systems. In the light of traditional network theory, one can see this framework as moving the information of when things happen from the dynamical system on the network, to the network itself. Since fundamental properties, such as the transitivity of edges, do not necessarily hold in temporal networks, many of these methods need to be quite different from those for static networks. The study of