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. 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.

  3. Multiple Forms of Learning Yield Temporally Distinct Electrophysiological Repetition Effects

    PubMed Central

    Badre, David; Wagner, Anthony D.

    2010-01-01

    Prior experience with a stimulus leads to multiple forms of learning that facilitate subsequent behavior (repetition priming) and neural processing (repetition suppression). Learning can occur at the level of stimulus-specific features (stimulus learning), associations between stimuli and selected decisions (stimulus–decision learning), and associations between stimuli and selected responses (stimulus–response learning). Although recent functional magnetic resonance imaging results suggest that these distinct forms of learning are associated with repetition suppression (neural priming) in dissociable regions of frontal and temporal cortex, a critical question is how these different forms of learning influence cortical response dynamics. Here, electroencephalography (EEG) measured the temporal structure of neural responses when participants classified novel and repeated stimuli, using a design that isolated the effects of distinct levels of learning. Event-related potential and spectral EEG analyses revealed electrophysiological effects due to stimulus, stimulus–decision, and stimulus–response learning, demonstrating experience-dependent cortical modulation at multiple levels of representation. Stimulus-level learning modulated cortical dynamics earlier in the temporal-processing stream relative to stimulus–decision and stimulus–response learning. These findings indicate that repeated stimulus processing, including the mapping of stimuli to decisions and actions, is influenced by stimulus-level and associative learning mechanisms that yield multiple forms of experience-dependent cortical plasticity. PMID:19915094

  4. Multiple temporal mosaicing for Landsat satellite images

    NASA Astrophysics Data System (ADS)

    Guo, Yi; Li, Feng; Caccetta, Peter; Devereux, Drew

    2017-01-01

    Cloud removal is a very important preprocessing step when using aerial and spaceborne optical sensors for land surface and cover applications. Methods that have been proposed for identifying cloud-affected pixels range from classification and segmentation type approaches applied to individual images to outlier detection type methods applied to time-series of images. The choice of method is influenced by considerations including the requirements of the application, the image characteristics, and how frequently images over a given area are acquired. When many images are acquired in a period where land surface cover exhibits negligible change, an image formed by compositing from a series of images taken in a relatively short period of time will suffice for further analysis. It is highly desirable to fully automate this compositing process. To this end, we propose the multiple temporal mosaicing (MTM) algorithm. It uses, in the first instance, a cloud score for each pixel in the images to separate/partially separate cloud-affected pixels from noncloud pixels. These cloud scores are then combined with the output from existing cloud identification methods and date preference to determine the likelihood of given pixels being considered as good candidates to be included in the final image. Moreover, the spatial smoothness is incorporated to ensure that the pixels of a small neighborhood are from the same image so that the final image looks smoother. We apply MTM to two Landsat scenes. The resulting images show the effectiveness of this method. The methodology can be applied to images acquired from other sensors.

  5. Relative Priming of Temporal Local-Global Levels in Auditory Hierarchical Stimuli

    PubMed Central

    List, Alexandra; Justus, Timothy

    2009-01-01

    Priming is a useful tool for ascertaining the circumstances under which previous experiences influence behavior. Previously, using hierarchical stimuli, we demonstrated that selectively attending to one temporal scale of an auditory stimulus improved subsequent attention to a repeated (vs. changed) temporal scale, i.e., we demonstrated inter-trial auditory temporal level-priming. Here, we have extended those results to address whether level-priming relied on absolute or relative temporal information. Both relative and absolute temporal information are important in auditory perception: speech and music can be recognized over various temporal scales, but become uninterpretable to a listener when presented too quickly or slowly. We first confirmed that temporal level-priming generalized over new temporal scales. Second, in the context of multiple temporal scales, we found that temporal level-priming operates predominantly on the basis of relative, rather than absolute, temporal information. These findings are discussed in the context of expectancies and relational invariance in audition. PMID:20045889

  6. Automatic bias of temporal expectations following temporally regular input independently of high-level temporal expectation.

    PubMed

    Breska, Assaf; Deouell, Leon Y

    2014-07-01

    Exposure to rhythmic stimulation results in facilitated responses to events that appear in-phase with the rhythm and modulation of anticipatory and target-evoked brain activity, presumably reflecting "exogenous," unintentional temporal expectations. However, the extent to which this effect is independent from intentional processes is not clear. In two EEG experiments, we isolated the unintentional component of this effect from high-level, intentional factors. Visual targets were presented either in-phase or out-of-phase with regularly flickering colored stimuli. In different blocks, the rhythm could be predictive (i.e., high probability for in-phase target) or not, and the color could be predictive (i.e., validly cue the interval to the target) or not. Exposure to nonpredictive rhythms resulted in faster responses for in-phase targets, even when the color predicted specific out-of-phase target times. Also, the contingent negative variation, an EEG component reflecting temporal anticipation, followed the interval of the nonpredictive rhythm and not that of the predictive color. Thus, rhythmic stimulation unintentionally induced expectations, even when this was detrimental. Intentional usage of predictive rhythms to form expectations resulted in a stronger behavioral effect, and only predictive cues modulated the latency of the target-evoked P3, presumably reflecting stimulus evaluation. These findings establish the existence of unintentional temporal expectations in rhythmic contexts, dissociate them from intentional expectations, and highlight the need to distinguish between the source of expectation (exogenous-endogenous) and the level of voluntary control involved in it (unintentional-intentional).

  7. 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.

  8. 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 ...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Outlines of a multiple trace theory of temporal preparation

    PubMed Central

    Los, Sander A.; Kruijne, Wouter; Meeter, Martijn

    2014-01-01

    We outline a new multiple trace theory of temporal preparation (MTP), which accounts for behavior in reaction time (RT) tasks in which the participant is presented with a warning stimulus (S1) followed by a target stimulus (S2) that requires a speeded response. The theory assumes that during the foreperiod (FP; the S1–S2 interval) inhibition is applied to prevent premature response, while a wave of activation occurs upon the presentation of S2. On each trial, these actions are stored in a separate memory trace, which, jointly with earlier formed memory traces, starts contributing to preparation on subsequent trials. We show that MTP accounts for classic effects in temporal preparation, including mean RT–FP functions observed under a variety of FP distributions and asymmetric sequential effects. We discuss the advantages of MTP over other accounts of these effects (trace-conditioning and hazard-based explanations) and suggest a critical experiment to empirically distinguish among them. PMID:25285088

  15. 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

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. Temporal change in forest fragmentation at multiple scales

    Treesearch

    J.D. Wickham; K.H. Riitters; T.G. Wade; J.W. Coulston

    2007-01-01

    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 region and the state of New Jersey to compare patch-based and area–density scaling measures...

  3. 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

  4. 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

  5. Multiple soliton self-frequency shift cancellations in a temporally tailored photonic crystal fiber

    SciTech Connect

    Liu, Lai; Kang, Zhe; Li, Qing; Gao, Xuejian; Qin, Guanshi E-mail: wpqin@jlu.edu.cn; Qin, Weiping E-mail: wpqin@jlu.edu.cn; Liao, Meisong; Hu, Lili; Ohishi, Yasutake

    2014-11-03

    We report the generation of multiple soliton self-frequency shift cancellations in a temporally tailored tellurite photonic crystal fiber (PCF). The temporally regulated group velocity dispersion (GVD) is generated in the fiber by soliton induced optical Kerr effect. Two red-shifted dispersive waves spring up when two Raman solitons meet their own second zero-dispersion-wavelengths in the PCF. These results show how, through temporally tailored GVD, nonlinearities can be harnessed to generate unexpected effects.

  6. Multiple routes from occipital to temporal cortices during reading

    PubMed Central

    Richardson, Fiona M.; Seghier, Mohamed L.; Leff, Alex P.; Thomas, Michael S.C.; Price, Cathy J.

    2013-01-01

    Contemporary models of the neural system that supports reading propose that activity in a ventral occipital-temporal area (vOT) drives activity in higher order language areas, for example, those in the posterior and anterior superior temporal sulcus (pSTS and aSTS). We used fMRI with dynamic causal modelling (DCM) to investigate evidence for other routes from visual cortex to the left temporal lobe language areas. First we identified activations in posterior inferior occipital (iO) and vOT areas that were more activated for silent reading than listening to words and sentences; and in pSTS and aSTS areas that were commonly activated for reading relative to false-fonts and listening to words relative to reversed words. Second, in 3 different DCM analyses, we tested whether visual processing of words modulates activity from (1) iO→ vOT, iO→ pSTS, both or neither; (2) vOT→ pSTS, iO→pSTS, both or neither; and (3) pSTS→ aSTS, vOT→ aSTS, both or neither. We found that reading words increased connectivity (1) from iO to both pSTS and vOT; (2) to pSTS from both iO and vOT; and (3) to aSTS from both vOT and pSTS. These results highlight three potential processing streams in the occipito-temporal cortex: iO→pSTS→aSTS; iO→vOT→aSTS; and iO→vOT→pSTS→aSTS. We discuss these results in terms of cognitive models of reading and propose that efficient reading relies on the integrity of all these pathways. PMID:21632945

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

    PubMed

    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

  8. 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

  9. Temporal scaling of groundwater level fluctuations near a stream.

    PubMed

    Schilling, Keith E; Zhang, You-Kuan

    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 (β) 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.

  10. 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.

  11. 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

  12. 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).

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. Quantifying drivers of wild pig movement across multiple spatial and temporal scales

    USGS Publications Warehouse

    Kay, Shannon L.; Fischer, Justin W.; Monaghan, Andrew J.; Beasley, James C; Boughton, Raoul; Campbell, Tyler A; Cooper, Susan M; Ditchkoff, Stephen S; Hartley, Stephen B.; Kilgo, John C; Wisely, Samantha M; Wyckoff, A Christy; VerCauteren, Kurt C; Pipen, Kim M

    2017-01-01

    The analytical framework we present can be used to assess movement patterns arising from multiple data sources for a range of species while accounting for spatio-temporal correlations. Our analyses show the magnitude by which reaction norms can change based on the temporal scale of response data, illustrating the importance of appropriately defining temporal scales of both the movement response and covariates depending on the intended implications of research (e.g., predicting effects of movement due to climate change versus planning local-scale management). We argue that consideration of multiple spatial scales within the same framework (rather than comparing across separate studies post-hoc) gives a more accurate quantification of cross-scale spatial effects by appropriately accounting for error correlation.

  19. 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…

  20. 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…

  1. Flexible optical encryption with multiple users and multiple security levels

    NASA Astrophysics Data System (ADS)

    Nishchal, Naveen K.; Naughton, Thomas J.

    2011-02-01

    We present a basic optical encryption architecture that admits several cryptography applications based on multiplexing. Users can decrypt different private images from the same encrypted image, a superuser can have a key that decrypts all encrypted images, and multiplexed images can be encrypted with different levels of security. This system is presented in the context of a general framework of optical encryption application development. We illustrate with a real-world three-dimensional scene, captured with digital holography, and encrypted using the fractional Fourier transform, where different users have access to different three-dimensional objects in the scene.

  2. 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

  3. Temporal trends of postinjury multiple-organ failure: Still resource intensive, morbid, and lethal

    PubMed Central

    Sauaia, Angela; Moore, Ernest E.; Johnson, Jeffrey L.; Chin, Theresa L.; Banerjee, Anirban; Sperry, Jason L.; Maier, Ronald V.; Burlew, C. Cothren

    2014-01-01

    BACKGROUND While the incidence of postinjury multiple-organ failure (MOF) has declined during the past decade, temporal trends of its morbidity, mortality, presentation patterns, and health care resources use have been inconsistent. The purpose of this study was to describe the evolving epidemiology of postinjury MOF from 2003 to 2010 in multiple trauma centers sharing standard treatment protocols. METHODS “Inflammation and Host Response to Injury Collaborative Program” institutions that enrolled more than 20 eligible patients per biennial during the 2003 to 2010 study period were included. The patients were aged 16 years to 90 years, sustained blunt torso trauma with hemorrhagic shock (systolic blood pressure < 90 mm Hg, base deficit ≥ 6 mEq/L, blood transfusion within the first 12 hours), but without severe head injury (motor Glasgow Coma Scale [GCS] score < 4). MOF temporal trends (Denver MOF score > 3) were adjusted for admission risk factors (age, sex, body max index, Injury Severity Score [ISS], systolic blood pressure, and base deficit) using survival analysis. RESULTS A total of 1,643 patients from four institutions were evaluated. MOF incidence decreased over time (from 17% in 2003–2004 to 9.8% in 2009–2010). MOF-related death rate (33% in 2003–2004 to 36% in 2009–2010), intensive care unit stay, and mechanical ventilation duration did not change over the study period. Adjustment for admission risk factors confirmed the crude trends. MOF patients required much longer ventilation and intensive care unit stay, compared with non-MOF patients. Most of the MOF-related deaths occurred within 2 days of the MOF diagnosis. Lung and cardiac dysfunctions became less frequent (57.6% to 50.8%, 20.9% to 12.5%, respectively), but kidney and liver failure rates did not change (10.1% to 12.5%, 15.2% to 14.1%). CONCLUSION Postinjury MOF remains a resource-intensive, morbid, and lethal condition. Lung injury is an enduring challenge and should be a research

  4. 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.

  5. Spatial and temporal characteristics of gait as outcome measures in multiple sclerosis (EDSS 0 to 6.5).

    PubMed

    Lizrova Preiningerova, Jana; Novotna, Klara; Rusz, Jan; Sucha, Lucie; Ruzicka, Evzen; Havrdova, Eva

    2015-02-10

    Gait impairment represents one of the most common and disabling symptom of multiple sclerosis. Quantification of the gait is an important aspect of clinical trials. In order to identify which temporal or spatial parameters of gait could be used as outcome measures in interventional studies of patients with different levels of disability, we evaluated characteristics of these parameters in MS patients across the whole spectrum of mobility from EDSS 0 to 6.5. This is a cross-sectional study of spatial and temporal parameters of gait at self selected speed and at fast speed of walking in 284 patients with multiple sclerosis (108 men, mean age 38 years ± SD 10.8 years, range 18-64) divided into seven levels of disability (EDSS 0 to 1.5, EDSS 2.0 to 2.5, EDSS 3.0 to 3.5, EDSS 4.0 to 4.5, EDSS 5.0 to 5.5, EDSS 6.0, EDSS 6.5). The velocity of gait decreases with increasing EDSS levels. Hovewer, the spatio-temporal parameters of gait that are involved in this process differ across the EDSS levels. The step length is decreased at higher EDSS levels up to the EDSS 6.0, but was not different between EDSS 6.0 and 6.5. The step time is significantly longer at EDSS 6.0 and 6.5, while the step length remains the same at those levels. The increase in percentage of double support time becomes statistically significant at EDSS 3.0-3.5 and continues to increase until EDSS 6.5. Variability of step time, step length or step width did not show significant difference between studied EDSS levels. There is no single spatio-temporal parameter of gait (other than velocity of gait) that would show significant differences among all levels of EDSS. The step length reflects shortening of steps at lower EDSS levels (2.0 to 6.0), and percentage of double support time better reflects changes at higher EDSS levels 3.0 - 6.5. Gait variability is not associated with disability in MS and therefore would not be a suitable outcome measure. These observations have to be considered when designing

  6. 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

  7. 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.

  8. Temporal trends of postinjury multiple-organ failure: still resource intensive, morbid, and lethal.

    PubMed

    Sauaia, Angela; Moore, Ernest E; Johnson, Jeffrey L; Chin, Theresa L; Banerjee, Anirban; Sperry, Jason L; Maier, Ronald V; Burlew, C Cothren

    2014-03-01

    While the incidence of postinjury multiple-organ failure (MOF) has declined during the past decade, temporal trends of its morbidity, mortality, presentation patterns, and health care resources use have been inconsistent. The purpose of this study was to describe the evolving epidemiology of postinjury MOF from 2003 to 2010 in multiple trauma centers sharing standard treatment protocols. "Inflammation and Host Response to Injury Collaborative Program" institutions that enrolled more than 20 eligible patients per biennial during the 2003 to 2010 study period were included. The patients were aged 16 years to 90 years, sustained blunt torso trauma with hemorrhagic shock (systolic blood pressure < 90 mm Hg, base deficit ≥ 6 mEq/L, blood transfusion within the first 12 hours), but without severe head injury (motor Glasgow Coma Scale [GCS] score < 4). MOF temporal trends (Denver MOF score > 3) were adjusted for admission risk factors (age, sex, body max index, Injury Severity Score [ISS], systolic blood pressure, and base deficit) using survival analysis. A total of 1,643 patients from four institutions were evaluated. MOF incidence decreased over time (from 17% in 2003-2004 to 9.8% in 2009-2010). MOF-related death rate (33% in 2003-2004 to 36% in 2009-2010), intensive care unit stay, and mechanical ventilation duration did not change over the study period. Adjustment for admission risk factors confirmed the crude trends. MOF patients required much longer ventilation and intensive care unit stay, compared with non-MOF patients. Most of the MOF-related deaths occurred within 2 days of the MOF diagnosis. Lung and cardiac dysfunctions became less frequent (57.6% to 50.8%, 20.9% to 12.5%, respectively), but kidney and liver failure rates did not change (10.1% to 12.5%, 15.2% to 14.1%). Postinjury MOF remains a resource-intensive, morbid, and lethal condition. Lung injury is an enduring challenge and should be a research priority. The lack of outcome improvements suggests

  9. 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

  10. Genetics of multiple myeloma: another heterogeneity level?

    PubMed Central

    Corre, Jill; Munshi, Nikhil

    2015-01-01

    Our knowledge of myeloma genetics remained limited and lagged behind many other hematologic malignancies because of the inherent difficulties in generating metaphases within the malignant plasma cell clone. With the development of molecular techniques (microarrays and next-generation sequencing), our understanding has been highly improved in the past 5 years. These studies have not only confirmed the prevalence of wide heterogeneity in myeloma at the molecular level, but has also provided a much clearer picture of the disease pathogenesis and progression. Whether these data will enable improvements in the therapeutic approach is still a matter of debate. The next improvement will come from detailed analyses of these molecular features to try to move from a treatment fitted to every patient to individualized therapies, taking into account the complexity of the chromosomal changes, the mutation spectrum, and subclonality evolution. PMID:25628468

  11. Effect of temporally correlated recharge on fluctuations of groundwater levels

    NASA Astrophysics Data System (ADS)

    Zhang, You-Kuan; Li, Zhongwei

    2006-10-01

    The effect of temporally correlated groundwater recharge, R(t), on fluctuations of the hydraulic head, h(t), was investigated with theoretical analyses and numerical simulations. Under an exponentially correlated recharge (ECR) process, analytical solutions for the hydraulic head covariance, Chh, and variance, σh2, were derived with a linear reservoir model. It was found that Chh and σh2 are time-dependent or nonstationary and reduce to those derived in a previous study for a white noise recharge (WNR) when the correlation timescale of the recharge process approaches zero. It is also found that σh2 for ECR is proportional to t2, while that for WNR is proportional to t for a substantial period of time, indicating that h(t) under ECR may vary as a smooth curve with no fractal characteristics (D = 1.0), while h(t) under WNR fluctuates as a Brownian motion (D = 1.5). The theoretical findings were verified by numerical simulations: The power spectra of the simulated heads with a one-dimensional transient groundwater flow model under ECR were shown to have distinct slopes in the log-log plot with D = 1.02. It was emphasized that the effect of temporal correlation in groundwater recharge is to dampen the fluctuations of the head and base flow and that daily groundwater recharge rates may have little temporal correlation in the hydrogeological conditions similar to the Walnut Creek site.

  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. Twice upon a time: multiple concurrent temporal recalibrations of audiovisual speech.

    PubMed

    Roseboom, Warrick; Arnold, Derek H

    2011-07-01

    Audiovisual timing perception can recalibrate following prolonged exposure to asynchronous auditory and visual inputs. It has been suggested that this might contribute to achieving perceptual synchrony for auditory and visual signals despite differences in physical and neural signal times for sight and sound. However, given that people can be concurrently exposed to multiple audiovisual stimuli with variable neural signal times, a mechanism that recalibrates all audiovisual timing percepts to a single timing relationship could be dysfunctional. In the experiments reported here, we showed that audiovisual temporal recalibration can be specific for particular audiovisual pairings. Participants were shown alternating movies of male and female actors containing positive and negative temporal asynchronies between the auditory and visual streams. We found that audiovisual synchrony estimates for each actor were shifted toward the preceding audiovisual timing relationship for that actor and that such temporal recalibrations occurred in positive and negative directions concurrently. Our results show that humans can form multiple concurrent estimates of appropriate timing for audiovisual synchrony.

  14. Temporally-Patterned Deep Brain Stimulation in a Mouse Model of Multiple Traumatic Brain Injury

    PubMed Central

    Tabansky, Inna; Quinkert, Amy Wells; Rahman, Nadera; Muller, Salomon Zev; Löfgren, Jesper; Rudling, Johan; Goodman, Alyssa; Wang, Yingping; Pfaff, Donald W.

    2014-01-01

    We report that mice with closed-head multiple traumatic brain injury (TBI) show a decrease in the motoric aspects of generalized arousal, as measured by automated, quantitative behavioral assays. Further, we found that temporally-patterned deep brain stimulation (DBS) can increase generalized arousal and spontaneous motor activity in this mouse model of TBI. This arousal increase is input-pattern-dependent, as changing the temporal pattern of DBS can modulate its effect on motor activity. Finally, an extensive examination of mouse behavioral capacities, looking for deficits in this model of TBI, suggest that the strongest effects of TBI in this model are found in the initiation of any kind of movement. PMID:25072520

  15. Patient-level temporal aggregation for text-based asthma status ascertainment.

    PubMed

    Wu, Stephen T; Juhn, Young J; Sohn, Sunghwan; Liu, Hongfang

    2014-01-01

    To specify the problem of patient-level temporal aggregation from clinical text and introduce several probabilistic methods for addressing that problem. The patient-level perspective differs from the prevailing natural language processing (NLP) practice of evaluating at the term, event, sentence, document, or visit level. We utilized an existing pediatric asthma cohort with manual annotations. After generating a basic feature set via standard clinical NLP methods, we introduce six methods of aggregating time-distributed features from the document level to the patient level. These aggregation methods are used to classify patients according to their asthma status in two hypothetical settings: retrospective epidemiology and clinical decision support. In both settings, solid patient classification performance was obtained with machine learning algorithms on a number of evidence aggregation methods, with Sum aggregation obtaining the highest F1 score of 85.71% on the retrospective epidemiological setting, and a probability density function-based method obtaining the highest F1 score of 74.63% on the clinical decision support setting. Multiple techniques also estimated the diagnosis date (index date) of asthma with promising accuracy. The clinical decision support setting is a more difficult problem. We rule out some aggregation methods rather than determining the best overall aggregation method, since our preliminary data set represented a practical setting in which manually annotated data were limited. Results contrasted the strengths of several aggregation algorithms in different settings. Multiple approaches exhibited good patient classification performance, and also predicted the timing of estimates with reasonable accuracy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. 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.

  17. Spatio-temporal hierarchical modeling of rates and variability of Holocene sea-level changes in the western North Atlantic and the Caribbean

    NASA Astrophysics Data System (ADS)

    Ashe, E.; Kopp, R. E.; Khan, N.; Horton, B.; Engelhart, S. E.

    2016-12-01

    Sea level varies over of both space and time. Prior to the instrumental period, the sea-level record depends upon geological reconstructions that contain vertical and temporal uncertainty. Spatio-temporal statistical models enable the interpretation of RSL and rates of change as well as the reconstruction of the entire sea-level field from such noisy data. Hierarchical models explicitly distinguish between a process level, which characterizes the spatio-temporal field, and a data level, by which sparse proxy data and its noise is recorded. A hyperparameter level depicts prior expectations about the structure of variability in the spatio-temporal field. Spatio-temporal hierarchical models are amenable to several analysis approaches, with tradeoffs regarding computational efficiency and comprehensiveness of uncertainty characterization. A fully-Bayesian hierarchical model (BHM), which places prior probability distributions upon the hyperparameters, is more computationally intensive than an empirical hierarchical model (EHM), which uses point estimates of hyperparameters, derived from the data [1]. Here, we assess the sensitivity of posterior estimates of relative sea level (RSL) and rates to different statistical approaches by varying prior assumptions about the spatial and temporal structure of sea-level variability and applying multiple analytical approaches to Holocene sea-level proxies along the Atlantic coast of North American and the Caribbean [2]. References: 1. N Cressie, Wikle CK (2011) Statistics for spatio-temporal data (John Wiley & Sons). 2. Kahn N et al. (2016). Quaternary Science Reviews (in revision).

  18. Levels of Processing with Free and Cued Recall and Unilateral Temporal Lobe Epilepsy

    ERIC Educational Resources Information Center

    Lespinet-Najib, Veronique; N'Kaoua, Bernard; Sauzeon, Helene; Bresson, Christel; Rougier, Alain; Claverie, Bernard

    2004-01-01

    This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right ''RTLE''=24; left ''LTLE''=24) and a normal group (n=24). The results indicated…

  19. 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.

  20. 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.

  1. Temporal coherence after multiple forward scattering through random three-dimensional inhomogeneities in an ocean waveguide.

    PubMed

    Chen, Tianrun; Ratilal, Purnima; Makris, Nicholas C

    2008-11-01

    An analytical expression is derived for the temporal coherence of an acoustic field after multiple forward scattering through random three-dimensional (3D) inhomogeneities in an ocean waveguide. This expression makes it possible to predict the coherence time scale of field fluctuations in ocean-acoustic measurements from knowledge of the oceanography. It is used to explain the time scale of acoustic field fluctuations observed at megameter ranges in various deep ocean-acoustic transmission experiments. It is shown that this time scale is nonlinearly related to the much longer coherence time scale of deep ocean internal waves through a multiple forward scattering process. It is also shown that 3D scattering effects become pronounced when the acoustic Fresnel width exceeds the cross-range coherence length of the deep ocean internal waves, which lead to frequency and range-dependent power losses in the forward field that may help to explain historic long range measurements.

  2. 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.

  3. 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.

  4. Irresistible ants: exposure to novel toxic prey increases consumption over multiple temporal scales.

    PubMed

    Herr, Mark W; Robbins, Travis R; Centi, Alan; Thawley, Christopher J; Langkilde, Tracy

    2016-07-01

    As species become increasingly exposed to novel challenges, it is critical to understand how evolutionary (i.e., generational) and plastic (i.e., within lifetime) responses work together to determine a species' fate or predict its distribution. The introduction of non-native species imposes novel pressures on the native species that they encounter. Understanding how native species exposed to toxic or distasteful invaders change their feeding behavior can provide insight into their ability to cope with these novel threats as well as broader questions about the evolution of this behavior. We demonstrated that native eastern fence lizards do not avoid consuming invasive fire ants following repeated exposure to this toxic prey. Rather fence lizards increased their consumption of these ants following exposure on three different temporal scales. Lizards ate more fire ants when they were exposed to this toxic prey over successive days. Lizards consumed more fire ants if they had been exposed to fire ants as juveniles 6 months earlier. Finally, lizards from populations exposed to fire ants over multiple generations consumed more fire ants than those from fire ant-free areas. These results suggest that the potentially lethal consumption of fire ants may carry benefits resulting in selection for this behavior, and learning that persists long after initial exposure. Future research on the response of native predators to venomous prey over multiple temporal scales will be valuable in determining the long-term effects of invasion by these novel threats.

  5. 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.

  6. Temporal scale dependent interactions between multiple environmental disturbances in microcosm ecosystems.

    PubMed

    Garnier, Aurélie; Pennekamp, Frank; Lemoine, Mélissa; Petchey, Owen L

    2017-06-15

    Global environmental change has negative impacts on ecological systems, impacting the stable provision of functions, goods, and services. Whereas effects of individual environmental changes (e.g. temperature change or change in resource availability) are reasonably well understood, we lack information about if and how multiple changes interact. We examined interactions among four types of environmental disturbance (temperature, nutrient ratio, carbon enrichment, and light) in a fully factorial design using a microbial aquatic ecosystem and observed responses of dissolved oxygen saturation at three temporal scales (resistance, resilience, and return time). We tested whether multiple disturbances combine in a dominant, additive, or interactive fashion, and compared the predictability of dissolved oxygen across scales. Carbon enrichment and shading reduced oxygen concentration in the short term (i.e. resistance); although no other effects or interactions were statistically significant, resistance decreased as the number of disturbances increased. In the medium term, only enrichment accelerated recovery, but none of the other effects (including interactions) were significant. In the long term, enrichment and shading lengthened return times, and we found significant two-way synergistic interactions between disturbances. The best performing model (dominant, additive, or interactive) depended on the temporal scale of response. In the short term (i.e. for resistance), the dominance model predicted resistance of dissolved oxygen best, due to a large effect of carbon enrichment, whereas none of the models could predict the medium term (i.e. resilience). The long-term response was best predicted by models including interactions among disturbances. Our results indicate the importance of accounting for the temporal scale of responses when researching the effects of environmental disturbances on ecosystems. © 2017 The Authors. Global Change Biology Published by John Wiley

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.…

  13. 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.…

  14. 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

  15. 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.

  16. 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.

  17. Wait-Time and Multiple Representation Levels in Chemistry Lessons

    ERIC Educational Resources Information Center

    Li, Winnie Sim Siew; Arshad, Mohammad Yusof

    2014-01-01

    Wait-time is an important aspect in a teaching and learning process, especially after the teacher has posed questions to students, as it is one of the factors in determining quality of students' responses. This article describes the practices of wait-time one after teacher's questions at multiple representation levels among twenty three chemistry…

  18. 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.…

  19. 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.…

  20. Marginal models for correlated binary responses with multiple classes and multiple levels of nesting.

    PubMed

    Qaqish, B F; Liang, K Y

    1992-09-01

    A model for correlated binary data is presented. Marginal probabilities and odds ratios are allowed to have general regression structures that include multiple classes and multiple levels of nesting. Estimation is done through the generalized estimating equations approach of Liang and Zeger (1986, Biometrika 73, 13-22). They are contrasted with conditional models and recommendations for choosing between the two are given. Examples from genetic epidemiology are presented.

  1. Multiple Levels of Influence That Impact Youth Tobacco Use.

    PubMed

    Cavazos-Rehg, Patricia A; Krauss, Melissa J; Sowles, Shaina J; Spitznagel, Edward L; Grucza, Richard; Chaloupka, Frank J; Bierut, Laura J

    2016-04-01

    Multiple levels of influence interplay to impact youth tobacco use. We work towards understanding important policy and environmental strategies that are associated with youth tobacco use behaviors. We utilized data from participants of the Monitoring the Future (MTF) study and linked national data from multiple sources to assess correlates of youth tobacco use behaviors across individual, family, school, community, and state-level policy influences. Higher cigarette prices had the strongest association with youth tobacco use behaviors. Demographic and socio-economic characteristics at the individual, familial, and community/school-levels were associated with youth tobacco use behaviors. In the present study, we confirm that higher cigarette prices could help to reduce youth tobacco use behaviors. Several states are still lagging behind in terms of their low cigarette tax and they should enact tax policies to reduce youth tobacco use.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Deep-level stereoscopic multiple traps of acoustic vortices

    NASA Astrophysics Data System (ADS)

    Li, Yuzhi; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong

    2017-04-01

    Based on the radiation pattern of a planar piston transducer, the mechanisms underlying the generation of axially controllable deep-level stereoscopic multiple traps of acoustic vortices (AV) using sparse directional sources were proposed with explicit formulae. Numerical simulations for the axial and cross-sectional distributions of acoustic pressure and phase were conducted for various ka (product of the wave number and the radius of transducer) values at the frequency of 1 MHz. It was demonstrated that, for bigger ka, besides the main-AV (M-AV) generated by the main lobes of the sources, cone-shaped side-AV (S-AV) produced by the side lobes were closer to the source plane at a relatively lower pressure. Corresponding to the radiation angles of pressure nulls between the main lobe and the side lobes of the sources, vortex valleys with nearly pressure zero could be generated on the central axis to form multiple traps, based on Gor'kov potential theory. The number and locations of vortex valleys could be controlled accurately by the adjustment of ka. With the established eight-source AV generation system, the existence of the axially controllable multiple traps was verified by the measured M-AV and S-AVs as well as the corresponding vortex valleys. The favorable results provided the feasibility of deep-level stereoscopic control of AV and suggested potential application of multiple traps for particle manipulation in the area of biomedical engineering.

  7. 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.

  8. Urbanization-induced habitat fragmentation erodes multiple components of temporal diversity in a Southern California native bee assemblage.

    PubMed

    Hung, Keng-Lou James; Ascher, John S; Holway, David A

    2017-01-01

    Despite a large number of ecological studies that document diversity loss resulting from anthropogenic disturbance, surprisingly few consider how disturbance affects temporal patterns of diversity that result from seasonal turnover of species. Temporal dynamics can play an important role in the structure and function of biological assemblages. Here, we investigate the temporal diversity patterns of bee faunas in Southern California coastal sage scrub ecosystems that have been extensively fragmented by urbanization. Using a two-year dataset of 235 bee species (n = 12,036 specimens), we compared 1-ha plots in scrub fragments and scrub reserves with respect to three components of temporal diversity: overall plot-level diversity pooled over time (temporal gamma diversity), diversity at discrete points in time (temporal alpha diversity), and seasonal turnover in assemblage composition (temporal beta diversity). Compared to reserves, fragments harbored bee assemblages with lower species richness and assemblage evenness both when summed across temporal samples (i.e., lower temporal gamma diversity) and at single points in time (i.e., lower temporal alpha diversity). Bee assemblages in fragments also exhibited reduced seasonal turnover (i.e., lower temporal beta diversity). While fragments and reserves did not differ in overall bee abundance, bee abundance in fragments peaked later in the season compared to that in reserves. Our results argue for an increased awareness of temporal diversity patterns, as information about the distinct components of temporal diversity is essential both for characterizing the assemblage dynamics of seasonal organisms and for identifying potential impacts of anthropogenic disturbance on ecosystem function through its effects on assemblage dynamics.

  9. Urbanization-induced habitat fragmentation erodes multiple components of temporal diversity in a Southern California native bee assemblage

    PubMed Central

    Ascher, John S.; Holway, David A.

    2017-01-01

    Despite a large number of ecological studies that document diversity loss resulting from anthropogenic disturbance, surprisingly few consider how disturbance affects temporal patterns of diversity that result from seasonal turnover of species. Temporal dynamics can play an important role in the structure and function of biological assemblages. Here, we investigate the temporal diversity patterns of bee faunas in Southern California coastal sage scrub ecosystems that have been extensively fragmented by urbanization. Using a two-year dataset of 235 bee species (n = 12,036 specimens), we compared 1-ha plots in scrub fragments and scrub reserves with respect to three components of temporal diversity: overall plot-level diversity pooled over time (temporal gamma diversity), diversity at discrete points in time (temporal alpha diversity), and seasonal turnover in assemblage composition (temporal beta diversity). Compared to reserves, fragments harbored bee assemblages with lower species richness and assemblage evenness both when summed across temporal samples (i.e., lower temporal gamma diversity) and at single points in time (i.e., lower temporal alpha diversity). Bee assemblages in fragments also exhibited reduced seasonal turnover (i.e., lower temporal beta diversity). While fragments and reserves did not differ in overall bee abundance, bee abundance in fragments peaked later in the season compared to that in reserves. Our results argue for an increased awareness of temporal diversity patterns, as information about the distinct components of temporal diversity is essential both for characterizing the assemblage dynamics of seasonal organisms and for identifying potential impacts of anthropogenic disturbance on ecosystem function through its effects on assemblage dynamics. PMID:28854229

  10. Temporal trends in the risk of developing multiple primary cancers: a systematic review.

    PubMed

    Ye, Yuanzi; Neil, Amanda L; Wills, Karen E; Venn, Alison J

    2016-11-04

    Cancer survivors are at risk of developing second and subsequent primary cancers, referred to as multiple primary cancers (MPCs). It is not clear whether the risk of MPCs has increased over recent decades, but increasing use of radiological imaging and potentially harmful effects of certain cancer treatments raise this possibility. A systematic review was undertaken to assess whether there has been a temporal change in the risk of developing MPCs. A systematic search to identify population-based studies of MPCs was performed in Medline/PubMed and Embase databases from inception to August 2016. Included studies were those reporting risk of MPCs for all sites combined following a first cancer at any site or a specific site, using standard incidence ratios (SIRs) or equivalent, and with analysis stratified by calendar years. We identified 28 articles eligible for inclusion, comprising 26 population-based studies and two monographs. MPC incidence was reported in nearly 6.5 million cancer survivors. For all first cancer sites combined, a higher rate of MPCs was reported in more recent than earlier calendar periods in four of the six relevant studies. The SIRs ranged from 1.14 for a first cancer diagnosis in the early 1980s to 1.21-1.46 in the late 1990s in the USA and Australia. Two studies from Italy and France showed no significant difference in SIRs across time periods 1978-2010 and 1989-2004. The remaining 22 studies reported various temporal trends in the risk of developing MPCs after a first cancer at a specific site, but most showed little change. Overall, the risk of developing MPCs appears to have increased since the 1980s when considering studies of all primary cancer sites combined from the USA and Australia but not from Europe. With the introduction of more routine nuclear medical imaging over the last 15 years, more studies are needed to confirm recent trends of MPC risk in adult cancer survivors.

  11. Designing multiple-choice test items at higher cognitive levels.

    PubMed

    Su, Whei Ming; Osisek, Paul J; Montgomery, Cynthia; Pellar, Suzanne

    2009-01-01

    In the midst of a nursing faculty shortage, many academic institutions hire clinicians who are not formally prepared for an academic role. These novice faculty face an immediate need to develop teaching skills. One area in particular is test construction. To address this need, the authors describe how faculty from one course designed multiple-choice test items at higher cognitive levels and simultaneously achieved congruence with critical-thinking learning objectives defined by the course.

  12. 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

  13. A By-Level Analysis of Multiplicative Exponential Linear Logic

    NASA Astrophysics Data System (ADS)

    Gaboardi, Marco; Roversi, Luca; Vercelli, Luca

    We study the relations between Multiplicative Exponential Linear Logic ( mELL) and Baillot-Mazza Linear Logic by Levels ( mL 3). We design a decoration-based translation between propositional mELL and propositional mL 3. The translation preserves the cut elimination. Moreover, we show that there is a proof net {Pi} of second order mELL that cannot have a representative {Pi'} in second order mL 3 under any decoration. This suggests that levels can be an analytical tool in understanding the complexity of second order quantifier.

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

    PubMed

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

    2007-04-11

    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. 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. 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).

  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. Spatio-temporal patterns of dengue in Malaysia: combining address and sub-district level.

    PubMed

    Ling, Cheong Y; Gruebner, Oliver; Krämer, Alexander; Lakes, Tobia

    2014-11-01

    Spatio-temporal patterns of dengue risk in Malaysia were studied both at the address and the sub-district level in the province of Selangor and the Federal Territory of Kuala Lumpur. We geocoded laboratory-confirmed dengue cases from the years 2008 to 2010 at the address level and further aggregated the cases in proportion to the population at risk at the sub-district level. Kulldorff's spatial scan statistic was applied for the investigation that identified changing spatial patterns of dengue cases at both levels. At the address level, spatio-temporal clusters of dengue cases were concentrated at the central and south-eastern part of the study area in the early part of the years studied. Analyses at the sub-district level revealed a consistent spatial clustering of a high number of cases proportional to the population at risk. Linking both levels assisted in the identification of differences and confirmed the presence of areas at high risk for dengue infection. Our results suggest that the observed dengue cases had both a spatial and a temporal epidemiological component, which needs to be acknowledged and addressed to develop efficient control measures, including spatially explicit vector control. Our findings highlight the importance of detailed geographical analysis of disease cases in heterogeneous environments with a focus on clustered populations at different spatial and temporal scales. We conclude that bringing together information on the spatio-temporal distribution of dengue cases with a deeper insight of linkages between dengue risk, climate factors and land use constitutes an important step towards the development of an effective risk management strategy.

  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. 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…

  19. 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.

  20. Correlation among external auditory canal anomaly, temporal bone malformation, and hearing levels in patients with microtia.

    PubMed

    Chen, Kun; Liu, Liu; Shi, Runjie; Wang, Peihua; Chen, Dong; Xiao, Hua

    2017-06-01

    We conducted a retrospective study to evaluate the relationship between external auditory canal (EAC) anomaly, temporal bone abnormality, and hearing levels using objective scoring systems in Chinese patients with microtia. The study population consisted of 106 ears of 94 Chinese patients (67 male and 27 female) aged 5 to 45 years (mean: 12.6) with microtia. The EAC abnormalities were classified into 4 types according to Schuknecht's criteria: type A, type B, type C, and type D. Developmental anomalies of the temporal bone were evaluated by Jahrsdoerfer computed tomography (CT) scoring system using high-resolution CT scans of the temporal bone. Temporal bone malformation parameters were divided into 4 subgroups: ossicular chain development, windows connected to the cochlea, aeration development of the middle ear, and facial nerve aberration. Hearing levels (air conduction and bone conduction) were examined. Outcomes parameters included correlation coefficients (r) and a number of other variables. The total points (10 points) and subtotal points related to ossicles (4 points), windows (2 points), aeration (2 points), and facial nerve (1 point) correlated inversely with the EAC abnormalities. The hearing levels (air conduction, r = 0.396, p <0.01; bone conduction, r = 0.21, p = 0.03) correlated significantly with the EAC abnormalities of Schuknecht's classification. We conclude that the better developed the external auditory canal, the better developed the temporal bone and the better developed the external auditory canal, the better hearing level. The hearing level also can serve as an indicator to determine whether a patient will be suitable for reconstructive surgery.

  1. 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.

  2. 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.

  3. Exploiting Multiple Levels of Parallelism in Sparse Matrix-Matrix Multiplication

    SciTech Connect

    Azad, Ariful; Ballard, Grey; Buluc, Aydin; Demmel, James; Grigori, Laura; Schwartz, Oded; Toledo, Sivan; Williams, Samuel

    2016-11-08

    Sparse matrix-matrix multiplication (or SpGEMM) is a key primitive for many high-performance graph algorithms as well as for some linear solvers, such as algebraic multigrid. The scaling of existing parallel implementations of SpGEMM is heavily bound by communication. Even though 3D (or 2.5D) algorithms have been proposed and theoretically analyzed in the flat MPI model on Erdös-Rényi matrices, those algorithms had not been implemented in practice and their complexities had not been analyzed for the general case. In this work, we present the first implementation of the 3D SpGEMM formulation that exploits multiple (intranode and internode) levels of parallelism, achieving significant speedups over the state-of-the-art publicly available codes at all levels of concurrencies. We extensively evaluate our implementation and identify bottlenecks that should be subject to further research.

  4. Exploiting Multiple Levels of Parallelism in Sparse Matrix-Matrix Multiplication

    DOE PAGES

    Azad, Ariful; Ballard, Grey; Buluc, Aydin; ...

    2016-11-08

    Sparse matrix-matrix multiplication (or SpGEMM) is a key primitive for many high-performance graph algorithms as well as for some linear solvers, such as algebraic multigrid. The scaling of existing parallel implementations of SpGEMM is heavily bound by communication. Even though 3D (or 2.5D) algorithms have been proposed and theoretically analyzed in the flat MPI model on Erdös-Rényi matrices, those algorithms had not been implemented in practice and their complexities had not been analyzed for the general case. In this work, we present the first implementation of the 3D SpGEMM formulation that exploits multiple (intranode and internode) levels of parallelism, achievingmore » significant speedups over the state-of-the-art publicly available codes at all levels of concurrencies. We extensively evaluate our implementation and identify bottlenecks that should be subject to further research.« less

  5. 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

  6. 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

  7. Information Mining of Spatio-Temporal Evolution of Lakes Based on Multiple Dynamic Measurements

    NASA Astrophysics Data System (ADS)

    Feng, W.; Chen, J.

    2017-09-01

    Lakes are important water resources and integral parts of the natural ecosystem, and it is of great significance to study the evolution of lakes. The area of each lake increased and decreased at the same time in natural condition, only but the net change of lakes' area is the result of the bidirectional evolution of lakes. In this paper, considering the effects of net fragmentation, net attenuation, swap change and spatial invariant part in lake evolution, a comprehensive evaluation indexes of lake dynamic evolution were defined,. Such degree contains three levels of measurement: 1) the swap dynamic degree (SDD) reflects the space activity of lakes in the study period. 2) the attenuation dynamic degree (ADD) reflects the net attenuation of lakes into non-lake areas. 3) the fragmentation dynamic degree (FDD) reflects the trend of lakes to be divided and broken into smaller lakes. Three levels of dynamic measurement constitute the three-dimensional "Swap - attenuation - fragmentation" dynamic evolution measurement system of lakes. To show its effectiveness, the dynamic measurement was applied to lakes in Jianghan Plain, the middle Yangtze region of China for a more detailed analysis of lakes from 1984 to 2014. In combination with spatial-temporal location characteristics of lakes, the hidden information in lake evolution in the past 30 years can be revealed.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Spatio-temporal semiparametric models for NO₂ and PM₁₀ concentration levels in Athens, Greece.

    PubMed

    Gryparis, Alexandros; Dimakopoulou, Konstantina; Pedeli, Xanthi; Katsouyanni, Klea

    2014-05-01

    Studies of air pollution effects on health are often based on ecological measurements. Our aim was to develop spatio-temporal models that estimate daily levels of NO2 and PM10 at every point in space, within the greater Athens area. We applied a semiparametric approach using spatial and temporal covariates and a bivariate smooth thin plate function. We evaluated the predictions of our models against the exposure estimates that are typically used in health studies. For model validation we used a temporal and a spatial approach. The adjusted-R(2) of the developed exposure models was 0.53 and 0.75 for PM10 and NO2 respectively; the spatial terms in our models explained 41.5% and 64.5% and the temporal explained 52.85% and 32.0% of the variability in PM10 and NO2, respectively. There was no temporal or spatial left over autocorrelation in the residuals. We performed a leave-one-out cross validation and the adjusted-R(2) were 0.41 for PM10 and 0.71 for NO2. The developed model showed good validity when comparing predicted and observed measures for the 2010 data. Our models performed better compared to the "ecological" estimates and estimates based on the "nearest monitoring site". Our spatio-temporal model makes valid predictions, it introduces substantial geographical variability, it reduces the bias when compared with the "ecological" estimates and the estimates based on the "nearest monitoring site" and it can be used for a more personalized exposure assessment in health studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Levels, temporal trends, and tissue distribution of perfluorinated surfactants in freshwater fish from Asian countries.

    PubMed

    Murakami, Michio; Adachi, Nozomi; Saha, Mahua; Morita, Chiaki; Takada, Hideshige

    2011-11-01

    Perfluorinated surfactants (PFSs) in Asian freshwater fish species were analyzed to investigate tissue distribution, temporal trends, extent of pollution, and level of PFS exposure through food intake. Freshwater fish species, namely carp, snakehead, and catfish, were collected in Japan, Vietnam, India, Malaysia, and Thailand, and 10 PFSs, including perfluorooctanesulfonate (PFOS) and perfluorooctanoate, were analyzed by liquid chromatography-tandem mass spectrometry. PFSs in carp in Tokyo were more concentrated in kidneys (Σ10 PFSs = 257 ± 95 ng/g wet weight [ww]) and livers (119 ± 36 ng/g ww) than in ovaries (43 ± 2 ng/g ww) and muscles (24 ± 17 ng/g ww). Concentrations of PFOS and its precursor, perfluorooctane sulfonamide, in livers of carp and in waters in Tokyo showed a dramatic decrease during the last decade, probably because of 3 M's phasing-out of the manufacture of perfluorooctanesulfonyl-fluoride-based products in 2000. In contrast, continuing contamination by long-chain perfluorocarboxylates (PFCAs) with ≥ 9 fluorinated carbons was seen in multiple media, suggesting that these compounds continue to be emitted. PFS concentrations in freshwater fish species in tropical Asian countries were generally lower than those in developed countries, such as Japan, e.g., for PFOS in muscle, Vietnam < 0.05-0.3 ng/g ww; India < 0.05-0.2 ng/g ww; Malaysia < 0.05-0.2 ng/g ww; Thailand < 0.05 ng/g ww; and Japan (Tokyo) = 5.1-22 ng/g ww. Daily intake of short-chain PFCAs with ≤ 8 fluorinated carbons from freshwater fish species in Japan was approximately one order of magnitude lower than that from drinking water, whereas daily intake of PFOS and long-chain PFCAs with ≥ 9 fluorinated carbons from freshwater fish species was comparable with or greater than that from drinking water. Because the risk posed by exposure to these compounds through intake of fish species is a matter of concern, we recommend the continued monitoring of PFS levels in Asian developing

  14. A multiple index integrating different levels of organization.

    PubMed

    Cortes, Rui; Hughes, Samantha; Coimbra, Ana; Monteiro, Sandra; Pereira, Vítor; Lopes, Marisa; Pereira, Sandra; Pinto, Ana; Sampaio, Ana; Santos, Cátia; Carrola, João; de Jesus, Joaquim; Varandas, Simone

    2016-10-01

    Many methods in freshwater biomonitoring tend to be restricted to a few levels of biological organization, limiting the potential spectrum of measurable of cause-effect responses to different anthropogenic impacts. We combined distinct organisational levels, covering biological biomarkers (histopathological and biochemical reactions in liver and fish gills), community based bioindicators (fish guilds, invertebrate metrics/traits and chironomid pupal exuviae) and ecosystem functional indicators (decomposition rates) to assess ecological status at designated Water Framework Directive monitoring sites, covering a gradient of human impact across several rivers in northern Portugal. We used Random Forest to rank the variables that contributed more significantly to successfully predict the different classes of ecological status and also to provide specific cut levels to discriminate each WFD class based on reference condition. A total of 59 Biological Quality Elements and functional indicators were determined using this procedure and subsequently applied to develop the integrated Multiple Ecological Level Index (MELI Index), a potentially powerful bioassessment tool. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 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.

  16. Conceptual framework for indexing visual information at multiple levels

    NASA Astrophysics Data System (ADS)

    Jaimes, Alejandro; Chang, Shih-Fu

    1999-12-01

    In this paper, we present a conceptual framework for indexing different aspects of visual information. Our framework unifies concepts from this literature in diverse fields such as cognitive psychology, library sciences, art, and the more recent content-based retrieval. We present multiple level structures for visual and non-visual and non- visual information. The ten-level visual structure presented provides a systematic way of indexing images based on syntax and semantics, and includes distinctions between general concept and visual concept. We define different types of relations at different levels of the visual structure, and also use a semantic information table to summarize important aspects related to an image. While the focus is on the development of a conceptual indexing structure, our aim is also to bring together the knowledge from various fields, unifying the issues that should be considered when building a digital image library. Our analysis stresses the limitations of state of the art content-based retrieval systems and suggests areas in which improvements are necessary.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Heterogeneity of the Left Temporal Lobe in Semantic Representation and Control: Priming Multiple versus Single Meanings of Ambiguous Words

    PubMed Central

    Jefferies, Elizabeth; Kircher, Tilo

    2011-01-01

    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. PMID:20732899

  2. 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

  3. 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.

  4. 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.

  5. Temporal weights in the level discrimination of time-varying sounds.

    PubMed

    Pedersen, Benjamin; Ellermeier, Wolfgang

    2008-02-01

    To determine how listeners weight different portions of the signal when integrating level information, they were presented with 1-s noise samples the levels of which randomly changed every 100 ms by repeatedly, and independently, drawing from a normal distribution. A given stimulus could be derived from one of two such distributions, a decibel apart, and listeners had to classify each sound as belonging to the "soft" or "loud" group. Subsequently, logistic regression analyses were used to determine to what extent each of the ten temporal segments contributed to the overall judgment. In Experiment 1, a nonoptimal weighting strategy was found that emphasized the beginning, and, to a lesser extent, the ending of the sounds. When listeners received trial-by-trial feedback, however, they approached equal weighting of all stimulus components. In Experiment 2, a spectral change was introduced in the middle of the stimulus sequence, changing from low-pass to high-pass noise, and vice versa. The temporal location of the stimulus change was strongly weighted, much as a new onset. These findings are not accounted for by current models of loudness or intensity discrimination, but are consistent with the idea that temporal weighting in loudness judgments is driven by salient events.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Images crossing borders: image and workflow sharing on multiple levels.

    PubMed

    Ross, Peeter; Pohjonen, Hanna

    2011-04-01

    Digitalisation of medical data makes it possible to share images and workflows between related parties. In addition to linear data flow where healthcare professionals or patients are the information carriers, a new type of matrix of many-to-many connections is emerging. Implementation of shared workflow brings challenges of interoperability and legal clarity. Sharing images or workflows can be implemented on different levels with different challenges: inside the organisation, between organisations, across country borders, or between healthcare institutions and citizens. Interoperability issues vary according to the level of sharing and are either technical or semantic, including language. Legal uncertainty increases when crossing national borders. Teleradiology is regulated by multiple European Union (EU) directives and legal documents, which makes interpretation of the legal system complex. To achieve wider use of eHealth and teleradiology several strategic documents were published recently by the EU. Despite EU activities, responsibility for organising, providing and funding healthcare systems remains with the Member States. Therefore, the implementation of new solutions requires strong co-operation between radiologists, societies of radiology, healthcare administrators, politicians and relevant EU authorities. The aim of this article is to describe different dimensions of image and workflow sharing and to analyse legal acts concerning teleradiology in the EU.

  11. Convergence in pigmentation at multiple levels: mutations, genes and function

    PubMed Central

    Manceau, Marie; Domingues, Vera S.; Linnen, Catherine R.; Rosenblum, Erica Bree; Hoekstra, Hopi E.

    2010-01-01

    Convergence—the independent evolution of the same trait by two or more taxa—has long been of interest to evolutionary biologists, but only recently has the molecular basis of phenotypic convergence been identified. Here, we highlight studies of rapid evolution of cryptic coloration in vertebrates to demonstrate that phenotypic convergence can occur at multiple levels: mutations, genes and gene function. We first show that different genes can be responsible for convergent phenotypes even among closely related populations, for example, in the pale beach mice inhabiting Florida's Gulf and Atlantic coasts. By contrast, the exact same mutation can create similar phenotypes in distantly related species such as mice and mammoths. Next, we show that different mutations in the same gene need not be functionally equivalent to produce similar phenotypes. For example, separate mutations produce divergent protein function but convergent pale coloration in two lizard species. Similarly, mutations that alter the expression of a gene in different ways can, nevertheless, result in similar phenotypes, as demonstrated by sister species of deer mice. Together these studies underscore the importance of identifying not only the genes, but also the precise mutations and their effects on protein function, that contribute to adaptation and highlight how convergence can occur at different genetic levels. PMID:20643733

  12. 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.

  13. 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.

  14. Levels and spatial and temporal trends of contaminants in Greenland biota: an updated review.

    PubMed

    Riget, F; Dietz, R; Vorkamp, K; Johansen, P; Muir, D

    2004-09-20

    Knowledge of contaminant levels in Greenland biota has increased substantially in recent years, particularly for persistent organic pollutants. This paper reviews and updates knowledge of spatial and temporal trends of Cd, Hg and organochlorines (PCBs, DDTs, HCHs, HCB and chlordane-related compounds) in Greenland terrestrial, freshwater and marine biota. The most comprehensive studies of spatial trends of Cd and Hg in the terrestrial ecosystem concern lichens, with relatively complete coverage, and caribou (Rangifer tarandus), with coverage mainly in different regions of central West Greenland and Southwest Greenland. The Arctic char (Salvelinus alpinus) is the only freshwater organism for which studies of spatial trends of Hg levels have been completed. Information on spatial trends of Cd and Hg in the marine environment is available from studies of fish, seabirds, ringed seals (Phoca hispida) and polar bears (Ursus maritimus). Geographical patterns of Cd and Hg in Greenland biota were not always consistent among different species or different studies. In landlocked Arctic char the concentrations of Hg decreased from south to north. In marine animals levels of Hg tended to be higher in East Greenland than in West Greenland and Cd levels were highest in biota from Disko Island in central West Greenland. The observed regional differences are difficult to explain but in most cases the causes appear to be natural rather than anthropogenic. Only a few time series covering the last 20 years exist for Cd and Hg. The one time series indicating a temporal change is for ringed seals in Northwest Greenland, which shows an increasing trend of Hg and a decreasing trend of Cd since 1984. Whether the changes reflect anthropogenic inputs, seal behaviour or other environmental factors is unknown. The most significant new insights have concerned organochlorines. In general, levels of these compounds were very low in terrestrial biota compared to marine species. Concentrations in

  15. Voice selectivity in the temporal voice area despite matched low-level acoustic cues.

    PubMed

    Agus, Trevor R; Paquette, Sébastien; Suied, Clara; Pressnitzer, Daniel; Belin, Pascal

    2017-09-14

    In human listeners, the temporal voice areas (TVAs) are regions of the superior temporal gyrus and sulcus that respond more to vocal sounds than a range of nonvocal control sounds, including scrambled voices, environmental noises, and animal cries. One interpretation of the TVA's selectivity is based on low-level acoustic cues: compared to control sounds, vocal sounds may have stronger harmonic content or greater spectrotemporal complexity. Here, we show that the right TVA remains selective to the human voice even when accounting for a variety of acoustical cues. Using fMRI, single vowel stimuli were contrasted with single notes of musical instruments with balanced harmonic-to-noise ratios and pitches. We also used "auditory chimeras", which preserved subsets of acoustical features of the vocal sounds. The right TVA was preferentially activated only for the natural human voice. In particular, the TVA did not respond more to artificial chimeras preserving the exact spectral profile of voices. Additional acoustic measures, including temporal modulations and spectral complexity, could not account for the increased activation. These observations rule out simple acoustical cues as a basis for voice selectivity in the TVAs.

  16. Multi-temporal, high spatial resolution water level monitoring of the Everglades

    NASA Astrophysics Data System (ADS)

    Hong, S.; Wdowinski, S.; Kim, S.

    2008-05-01

    Water level information in South Florida's Everglades is very important for understanding the hydrology of this fragile ecosystem. Currently water levels are determined by a dense stage (water level) network providing high spatial resolution observation. However, because there are a finite number of stage stations in Everglades, water levels in areas located between stage stations can only be estimated by interpolation. Space-borne Interferometric Synthetic Aperture Radar (InSAR) techniques were successfully used to detect high spatial resolution (20-50 meter pixel resolution) water level changes in the Everglades and other wetlands. However, the InSAR observations are relative, providing measure of water level changes (not absolute). In this study we presents a new InSAR technique which enables to estimate a time series of absolute water levels using radar observations acquired successively over the Everglades. In this preliminary stage, we limit our study to Water Conservation Area 1 (WCA1), which is a managed area located in the northern section of the Everglades. The main advantage of the new technique is the reconstruction of absolute water level information instead of previous approaches calculating only relative water level changes. The new technique is called Small Temporal Baseline Subset (STBAS), which utilizes highly coherent interferometric phases obtained only with relatively short time difference between two SAR acquisitions (e.g. 24 or 48 recurrence periods in Radarsat-1 SAR system). The observed interferometric observations have to be calibrated with ground truth data as the reference wetland sheet flow vary daily. We use daily stage data measured at 13 stage stations in WCA1 to calibrate the space-based observations. This information is integrated using the Singular Value Decomposition (SVD) method to generate a time series of absolute water levels. Our calibration-validation study shows a very good fit to the stage data. The correlation

  17. 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).

  18. 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...

  19. 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...

  20. Hearing levels in patients with microtia: correlation with temporal bone malformation.

    PubMed

    Ishimoto, Shin-ichi; Ito, Ken; Karino, Shotaro; Takegoshi, Hideki; Kaga, Kimitaka; Yamasoba, Tatsuya

    2007-03-01

    To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia. Retrospective case series study between 1992 and 2004. Academic, tertiary care referral medical center. We evaluated 115 ears of 89 patients (68 males, 21 females; mean age, 11 yr; range, 5-44 yr) with microtia. Hearing level was examined in patients with microtia. Developmental abnormalities of the temporal bone were evaluated by Jahrsdoerfer's computed tomography (CT) scoring system using high-resolution CT (HRCT) scans of the temporal bone. Temporal bone malformation scores were divided into four subgroups: ossicular development, windows connected to the cochlea, aeration of the middle ear cavity, and facial nerve aberration. Patients were divided into the stenosis and atresia groups on the basis of the appearance of the external auditory canal (EAC). We also evaluated the relationships between hearing level and four subtotal scores of the HRCT findings in the stenosis and atresia groups. There was no relationship between hearing level and total points of HRCT scoring system or between hearing level and severity of microtia scored by Marx classification. With regard to subtotal points related to ossicles (4 points), the hearing level in ears with low scores (<2) (64.7 +/- 1.6 dB) was significantly different (P = .03) from that in ears with high scores (> or =2) (54.0 +/- 2.8 dB) in the stenosis group. In the atresia group, the hearing level was 64.3 +/- 2.2 dB in ears with low scores and 62.3 +/- 1.1 in ears with high scores (P > .5). As for subtotal points related to the windows connected to cochlea (2 points), the hearing level was 64.8 +/- 2.6 dB in ears with low scores (0) and 55.9 +/- 2.4 dB in ears with high scores (> = 1) in the stenosis group. In the atresia group, the hearing level was 67.7 +/- 2.3 dB in ears with low scores and 61.5 +/- 1.0 in ears with high scores. There was significant difference between ears with low and high scores in the

  1. Temporal Hierarchical Adaptive Texture CRF for Automatic Detection of Gadolinium-Enhancing Multiple Sclerosis Lesions in Brain MRI.

    PubMed

    Karimaghaloo, Zahra; Rivaz, Hassan; Arnold, Douglas L; Collins, D Louis; Arbel, Tal

    2015-06-01

    We propose a conditional random field (CRF) based classifier for segmentation of small enhanced pathologies. Specifically, we develop a temporal hierarchical adaptive texture CRF (THAT-CRF) and apply it to the challenging problem of gad enhancing lesion segmentation in brain MRI of patients with multiple sclerosis. In this context, the presence of many nonlesion enhancements (such as blood vessels) renders the problem more difficult. In addition to voxel-wise features, the framework exploits multiple higher order textures to discriminate the true lesional enhancements from the pool of other enhancements. Since lesional enhancements show more variation over time as compared to the nonlesional ones, we incorporate temporal texture analysis in order to study the textures of enhanced candidates over time. The parameters of the THAT-CRF model are learned based on 2380 scans from a multi-center clinical trial. The effect of different components of the model is extensively evaluated on 120 scans from a separate multi-center clinical trial. The incorporation of the temporal textures results in a general decrease of the false discovery rate. Specifically, THAT-CRF achieves overall sensitivity of 95% along with false discovery rate of 20% and average false positive count of 0.5 lesions per scan. The sensitivity of the temporal method to the trained time interval is further investigated on five different intervals of 69 patients. Moreover, superior performance is achieved by the reviewed labelings of our model compared to the fully manual labeling when applied to the context of separating different treatment arms in a real clinical trial.

  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. Temporal and spatial dispersion of sound levels in a reverberant space

    NASA Astrophysics Data System (ADS)

    Guilhot, J. P.; Legros, C.; Flenner, J. P.

    1982-01-01

    Acoustical measurements in rooms are generally made with the aid of a random excitation signal, white noise or pink noise. The sound level measured at a point, fluctuates depending on the duration of the integration and of the bandwidth of the noise. If the measurement point is chosen in a random fashion in the room, the sound field can be simulated by a multidimensional random process which depends on time and on space. The mean square value of the acoustic pressure in time and in space is estimated. Spatial mean is estimated by sampling, by the choice of positions of source and of the point of measurement, and the mean over time by an integration of a finite duration. The spatial and temporal variances of the level of the acoustical pressure measured in a reverberant space are determined.

  4. Temporal and spatial dispersion of sound levels in a reverberant space

    NASA Astrophysics Data System (ADS)

    Guilhot, J. P.; Legros, C.; Flenner, J. P.

    The spatial and temporal variances of the level of the acoustical pressure measured in a reverberant space were determined. Acoustical measurements in rooms are generally made with the aid of a random excitation signal, white noise or pink noise and the sound level measured at a point, fluctuates depending on the duration of the integration and of the bandwidth of the noise. The measurement point is chosen in a random fashion in the room and the sound field is simulated by a multidimensional random process which depends on time and on space. The mean square value of the acoustic pressure in time and in space is estimated. Spatial mean is estimated by sampling, by the choice of positions of source and of the point of measurement and the mean over time by an integration of a finite duration.

  5. 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.

  6. Investigating the temporal relationship between individual-level social capital and health in fragile families.

    PubMed

    Nichols Dauner, Kim; Wilmot, Neil A; Schultz, Jennifer F

    2015-11-16

    The potential for social capital to influence health outcomes has received significant attention, yet few studies have assessed the temporal ordering between the two. Even less attention has been paid to more vulnerable populations, such as low-income women with children. Our objective was to explore how different dimensions of social capital impact future health status among this population. This study uses data from the Fragile Families and Child Well-Being (FFCWB) Study, which has followed a cohort of children and their families born in large U.S. cities between 1998 and 2000 to mostly minority, unmarried parents who tend to be at greater risk for falling into poverty. Four separate measures of social capital were constructed, which include measures of social support and trust, social participation, perceptions of neighborhood social cohesion, and perceptions of neighborhood social control. The temporal effect of social capital on self-reported health (SRH) is investigated using logistic regression and we hypothesize that higher levels of social capital are associated with higher levels of self-rated health. After controlling for socioeconomic and demographic factors related to social capital and self-rated health, social support and trust, perceptions of neighborhood social cohesion and control at an earlier point in time were positively associated with higher levels of health four-years later. Social participation was not related to increased health. The empirical results appear robust. Higher levels of social capital are predictive of improved health over a four-year time frame. These results suggest that policy initiatives supporting increasing the social capital available and accessible by low-income, urban, minority women are viable for improving health. Such policies may have the potential to reduce socioeconomic health disparities.

  7. 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

  8. [Potentially avoidable hospitalisation in Bologna, 1997-2000: temporal trend and differences by income level].

    PubMed

    Pirani, Monica; Schifano, Patrizia; Agabiti, Nera; Davoli, Marina; Caranci, Nicola; Perucci, Carlo Alberto

    2006-01-01

    To describe the temporal trend of hospitalisations for Ambulatory Care Sensitive Conditions (ACSCs) from 1997 to 2000 in Bologna (Italy) and to analyze the association with the income level. We have selected two panels of ACSCs: eight conditions for the paediatric/young population (<20 years of age) and fourteen for the adult population (> or =20 years of age). All discharges for ACSCs of residents in Bologna from Emilia-Romagna hospitals have been selected in the years 1997-2000. An indicator of social position was computed: the median per capita equivalent income by census block, obtained through record linkage between the Italian Tax Register (income earned in 1998) and the Population Register of Bologna. The direct age-standardized rates and the rate ratio by income level have been calculated. The Poisson regression model has been used to calculate the relative risk (RR) of hospitalizations for ACSCs. 2359 (17.6% of the total) hospitalisations have been selected among the paediatric/young population and 27822 (11.1% of the total) among the adult population. The annual age-adjusted rate of ACSC is 122.68 per 10000 persons among children and 176.60 among adults. The hospitalisation forACSCs among children is associated with a middle-low level of income (RR 1.55; CI 95% 1.35-1.78 for the lowest level vs. highest level), male gender and age <5 years old. In the adult population the risk of hospitalisation for ACSCs is higher among those with lower levels of income (RR 1.80; CI 95% 1.66-1.95 for the lowest level vs. highest level), moreover the RR is higher for men at every age. The admissions forACSCs among adults show a decreasing temporal trend. The disadvantaged groups of the population experience the highest risk of hospitalisation for ACSCs, with differences by gender and age groups. Although it is difficult to specifically identify the mechanisms potentially involved in the relationship between socioeconomic status and excess of hospitalisation, the

  9. Sorting photon wave packets using temporal-mode interferometry based on multiple-stage quantum frequency conversion

    NASA Astrophysics Data System (ADS)

    Reddy, D. V.; Raymer, M. G.; McKinstrie, C. J.

    2015-01-01

    All classical and quantum technologies that encode in and retrieve information from optical fields rely on the ability to selectively manipulate orthogonal field modes of light. Such manipulation can be achieved with high selectivity for polarization modes and transverse-spatial modes. For the time-frequency degree of freedom, this could efficiently be achieved for a limited choice of approximately orthogonal modes, i.e., nonoverlapping bins in time or frequency. We recently proposed a method that surmounts the selectivity barrier for sorting arbitrary orthogonal temporal modes [Opt. Lett. 39, 2924 (2014)., 10.1364/OL.39.002924] using cascaded interferometric quantum frequency conversion in nonlinear optical media. We call this method temporal-mode interferometry, as it has a close resemblance to the well-known separated-fields atomic interferometry method introduced by Ramsey. The method has important implications for quantum memories, quantum dense coding, quantum teleportation, and quantum key distribution. Here we explore the inner workings of the method in detail, and extend it to multiple stages with a concurrent asymptotic convergence of temporal-mode selectivity to unity. We also complete our analysis of pump-chirp compensation to counter pump-induced nonlinear phase modulation in four-wave mixing implementations.

  10. Temporal and spatial variability of annual extreme water level in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Yan, Yixin; Zheng, Jinhai; Li, Ling; Dong, Xue; Cai, Huijuan

    2009-10-01

    This paper is concerned with identifying the spatial and temporal patterns in the annual maximum and minimum water level in the Pearl River Delta (PRD) region. The Mann-Kendall test and Pettitt test are used to detect trends and abrupt change points, and the Trend Free Pre-Whitening (TFPW) approach then eliminates the effect of serial correlation in data series with significant autocorrelation. Approximately fifty years of the annual hydrological variables from 18 stations in the three major rivers (the West River, the North River, and the East River) are examined. The changing trends of the extremes in water level show different features in different parts of the PRD region. Generally speaking, in the upper part of the delta, the water levels show a decreasing trend while in the middle and lower part there is an increasing trend. This spatial pattern of the extreme water level variation is unlikely to be due to a long-term change in stream flow in the PRD region because the water level changes do not always coincide with the extreme stream flow variations. Sand excavation initiated in the 1980s and continuing for more than 20 years in almost all tributaries around the PRD region is one of the most serious intensive human activities affecting water levels. The result of the Pettitt test indicates that most abrupt change points occurred in 1980s-1990s, which reveals that sand excavation and channel regulation are likely to have been the most significant factors contributing to the change over this period. These anthropogenic activities modify the annual extreme water level dramatically in a way that affects the morphology of river channels and estuaries of the PRD and also the redistribution of discharge. However, there are differences in the geographic locations of significant trends for the water level investigated, which implies that these impacts are not spatially uniform.

  11. 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.

  12. 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

  13. Auditory hypergnosia as an example of psychic tonus in the temporal lobes: multiple case analyses.

    PubMed

    Braun, Claude M J; Duval, Julie; Guimond, Anik

    2005-01-01

    In 2006, Braun proposed a new model of hemispheric specialization of energy management by the brain, which he termed the "psychic tonus" model of hemispheric specialization. The term "psychic tonus" is deliberately general. It invites further investigation designed to incorporate various behavioral and cognitive modalities. At present, any cognitive operation or behavior likely to require energy expenditure, such as cardiovascular or metabolic, is considered to be at one extreme while any cognitive operation or behavior likely to reduce energy expenditure is considered to be at the other extreme. The model states that the left hemisphere of the brain is specialized to increase psychic tonus and the right to decrease it. The model predicts that the tonus of auditory representation ought to also manifest these hemispheric specializations in the temporal lobes. Specifically, it was predicted that pathological positive auditory tonus (auditory hallucination) ought to be associated more frequently with right temporal lobe lesions. Our analysis of a large number of previously published cases of patients with unilateral lesions supports the prediction.

  14. 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.

  15. Not FLEXible enough: Exploring the temporal dynamics of attentional reallocations with the multiple object tracking paradigm.

    PubMed

    Meyerhoff, Hauke S; Papenmeier, Frank; Jahn, Georg; Huff, Markus

    2016-06-01

    The dynamic environment of human observers requires continuous reallocations of visual attention to compensate for location changes of the attended objects. Particularly, situations with reduced spatial distance between targets and other objects in the display are crucial for keeping track of the target objects. In the present experiments, we explored how the temporal dynamics of such moments of reduced spacing affects the reallocation of visual attention. We asked participants to track 4 targets among indistinguishable distractors. Hereby, we manipulated whether target and distractor objects moved at a constant speed or whether their actual speed followed a sine wave profile. The variable speed oscillated around the constant speed thus maintaining average speed as well as traveled distance and average spatial proximity. We observed inferior tracking performance with variable speed profiles relative to constant speed profiles (Experiments 1a and 1b). When we increased the number of pairs of targets and distractors moving with a variable speed profile (Experiment 2), performance declined continuously. Remarkably, tracking performance also declined when only distractors moved at variable speeds, suggesting that the dynamic changes in interobject spacing rather than the variable speed impairs tracking (Experiment 3). In sum, our results provide evidence for a flexible allocation of the attentional resource toward targets suffering spatial interference by demonstrating the temporal constraints of the reallocation process. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. 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.

  17. 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.

  18. Serum phosphorylated neurofilament-heavy chain levels in multiple sclerosis patients.

    PubMed

    Gresle, M M; Liu, Y; Dagley, L F; Haartsen, J; Pearson, F; Purcell, A W; Laverick, L; Petzold, A; Lucas, R M; Van der Walt, A; Prime, H; Morris, D R; Taylor, B V; Shaw, G; Butzkueven, H

    2014-11-01

    We evaluated whether the measurement of serum phosphorylated neurofilament heavy chain (pNF-H) titre is likely to be a valid biomarker of axonal injury in multiple sclerosis (MS). Serum pNF-H concentrations were measured by ELISA in cases with relapsing-remitting (RR)-MS (n=81), secondary progressive (SP) MS (n=13) and primary progressive (PP)-MS; n=6) MS; first demyelinating event (FDE; n=82); and unaffected controls (n=135). A subset of MS cases (n=45) were re-sampled on one or multiple occasions. The Multiple Sclerosis Severity Score (MSSS) and MRI measures were used to evaluate associations between serum pNF-H status, disease severity and cerebral lesion load and activity. We confirmed the presence of pNF-H peptides in serum by ELISA. We showed that a high serum pNF-H titre was detectable in 9% of RR-MS and FDE cases, and 38.5% of SP-MS cases. Patients with a high serum pNF-H titre had higher average MSSS scores and T2 lesion volumes than patients with a low serum pNF-H titre. Repeated sampling of a subset of MS cases showed that pNF-H levels can fluctuate over time, likely reflecting temporal dynamics of axonal injury in MS. A subset of FDE/MS cases was found to have a high serum pNF-H titre, and this was associated with changes in clinical outcome measures. We propose that routine measurement of serum pNF-H should be further investigated for monitoring axonal injury in MS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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).

  7. Fission Multiplicity Detection With Temporal Gamma-Neutron Discrimination From Higher Order Time Correlation Statistics

    SciTech Connect

    Oberer, R.B.

    2002-01-17

    The subject of this thesis is the nondestructive assay (NDA) of nuclear materials. NDA is made possible by the fact that fissile and fertile transuranic isotopes emit characteristic radiations. Fission Multiplicity Detection (FMD) is the name of the standard technique used in NDA of nuclear materials in the 1960s and 1970s. It was characterized by the use of fast plastic scintillating detectors. These systems were used in both active and passive mode. These FMD systems were eventually replaced by thermal well counters as the standard NDA technique. The thermal well counters use {sup 3}He detectors embedded in a moderator. Among the passive neutron assay techniques, neutron multiplicity counting (NMC) in a thermal well counter is the preferred technique for the determination of fissile mass when spontaneous fission yields are significant. it is used in conjunction with gamma-ray spectroscopy to determine the isotopic composition of a sample. The major problem with the use of fast plastic detectors as used in FMD is that both neutrons and gamma rays are detected. The pulses from the two are indistinguishable. The disadvantages of this indistinguishability between neutron and gamma rays is explained further in the explanation of NMIS multiplicity in Section 2.5.

  8. Spatial, temporal and spatio-temporal clusters of measles incidence at the county level in Guangxi, China during 2004-2014: flexibly shaped scan statistics.

    PubMed

    Tang, Xianyan; Geater, Alan; McNeil, Edward; Deng, Qiuyun; Dong, Aihu; Zhong, Ge

    2017-04-04

    Outbreaks of measles re-emerged in Guangxi province during 2013-2014, where measles again became a major public health concern. A better understanding of the patterns of measles cases would help in identifying high-risk areas and periods for optimizing preventive strategies, yet these patterns remain largely unknown. Thus, this study aimed to determine the patterns of measles clusters in space, time and space-time at the county level over the period 2004-2014 in Guangxi. Annual data on measles cases and population sizes for each county were obtained from Guangxi CDC and Guangxi Bureau of Statistics, respectively. Epidemic curves and Kulldorff's temporal scan statistics were used to identify seasonal peaks and high-risk periods. Tango's flexible scan statistics were implemented to determine irregular spatial clusters. Spatio-temporal clusters in elliptical cylinder shapes were detected by Kulldorff's scan statistics. Population attributable risk percent (PAR%) of children aged ≤24 months was used to identify regions with a heavy burden of measles. Seasonal peaks occurred between April and June, and a temporal measles cluster was detected in 2014. Spatial clusters were identified in West, Southwest and North Central Guangxi. Three phases of spatio-temporal clusters with high relative risk were detected: Central Guangxi during 2004-2005, Midwest Guangxi in 2007, and West and Southwest Guangxi during 2013-2014. Regions with high PAR% were mainly clustered in West, Southwest, North and Central Guangxi. A temporal uptrend of measles incidence existed in Guangxi between 2010 and 2014, while downtrend during 2004-2009. The hotspots shifted from Central to West and Southwest Guangxi, regions overburdened with measles. Thus, intensifying surveillance of timeliness and completeness of routine vaccination and implementing supplementary immunization activities for measles should prioritized in these regions.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. Spatio-temporal characterization of the multiple current pulse regime of diffuse barrier discharges in helium with nitrogen admixtures

    NASA Astrophysics Data System (ADS)

    Bogaczyk, Marc; Tschiersch, Robert; Nemschokmichal, Sebastian; Meichsner, Jürgen

    2017-10-01

    This work reports on the spatio-temporal characterization of the multiple current pulse regime of diffuse barrier discharges driven by sine-wave feeding voltage at a frequency of 2~kHz in helium with small nitrogen admixtures. The discharge gap of 3~mm is bounded by glass plates on both plane electrodes. Priority is given to the lateral discharge inhomogeneities, underlying volume- and surface-memory effects, and the breakdown mechanism. Therefore, relevant processes in the discharge volume and on the dielectric surfaces were investigated by ICCD camera imaging and optical emission spectroscopy in combination with electrical measurements and surface charge diagnostics using the electro-optic Pockels effect of a bismuth silicon oxide crystal. The number of current pulses per half-cycle of the sine-wave voltage rises with increasing nitrogen admixture to helium due to the predominant role of the Penning ionization. Here, the transition from the first glow-like breakdown to the last Townsend-like breakdown is favored by residual species from the former breakdowns which enhance the secondary electron emission during the pre-phase of the later breakdowns. Moreover, the surface charge measurements reveal that the consecutive breakdowns occur alternately at central and peripheral regions on the electrode surface. These spatial inhomogeneities are conserved by the surface charge memory effect as pointed out by the recalculated spatio-temporal development of the gap voltage.

  14. Temporal lobe cortical pathology and inhibitory GABA interneuron cell loss are associated with seizures in multiple sclerosis

    PubMed Central

    Nicholas, Richard; Magliozzi, Roberta; Campbell, Graham; Mahad, Don; Reynolds, Richard

    2016-01-01

    Background: Seizures are recognised in multiple sclerosis (MS), but their true incidence and the mechanism by which they are associated with MS is unclear. Objective: The objective of this paper is to determine the lifetime frequency of seizures in the United Kingdom MS Tissue Bank (UKMSTB) population and any pathological features associated with seizures. Methods: We evaluated 255 individuals from the UKMSTB. A subset underwent analysis of cortical thickness, grey matter lesion (GML) (type and number) and cortical neuronal numbers (total and GABAergic). Results: A total of 37/255 patients had seizures (14.5% lifetime incidence); in 47% they were associated with concurrent infection. In those with seizures, death and wheelchair use occurred earlier and in 59% seizures developed after 15 years of disease. Seizures were associated with Type 1 GMLs and reduced cortical thickness in the middle temporal gyrus. Localised selective GABAergic interneuron loss in layers IV and VI was related to GMLs but was not explained by the presence of inflammation or by mitochondrial dysfunction within Type I GMLs. Conclusion: We confirm that seizure frequency rises in MS. Type I GMLs in the temporal lobe underlie a loss of inhibitory interneurons in cortical layers IV and VI and these changes could together with concurrent infection enhance susceptibility to seizures. PMID:25921040

  15. 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.

  16. Parallel evolution and vicariance in the guppy (Poecilia reticulata) over multiple spatial and temporal scales.

    PubMed

    Alexander, Heather J; Taylor, John S; Wu, Sampson Sze-Tsun; Breden, Felix

    2006-11-01

    Well-studied model systems present ideal opportunities to understand the relative roles of contemporary selection versus historical processes in determining population differentiation and speciation. Although guppy populations in Trinidad have been a model for studies of evolutionary ecology and sexual selection for more than 50 years, this work has been conducted with little understanding of the phylogenetic history of this species. We used variation in nuclear (X-src) and mitochondrial DNA (mtDNA) sequences to examine the phylogeographic history of Poecilia reticulata Peters (the guppy) across its entire natural range, and to test whether patterns of morphological divergence are a consequence of parallel evolution. Phylogenetic, nested clade, population genetic, and demographic analyses were conducted to investigate patterns of genetic structure at several temporal scales and are discussed in relation to vicariant events, such as tectonic activity and glacial cycles, shaping northeast South American river drainages. The mtDNA phylogeny defined five major lineages, each associated with one or more river drainages, and analysis of molecular variance also detected geographic structuring among these river drainages in an evolutionarily conserved nuclear (X-src) locus. Nested clade and other demographic analyses suggest that the eastern Venezuela/ western Trinidad region is likely the center of origin of P. reticulata. Mantel tests show that the divergence of morphological characters, known to differentiate on a local scale in response to natural and sexual selection pressures, is not associated with mtDNA genetic distance; however, TreeScan analysis identified several significant associations of these characters with the haplotype tree. Parallel upstream/downstream patterns of morphological adaptation in response to selection pressures reported in P. reticulata within Trinidad rivers appears to persist across the natural range. Our results together with previous

  17. Experimental low-level jaw clenching inhibits temporal summation evoked by electrical stimulation in healthy human volunteers.

    PubMed

    Tada, Hiroaki; Torisu, Tetsurou; Tanaka, Mihoko; Murata, Hiroshi; De Laat, Antoon; Svensson, Peter

    2015-05-01

    To examine the effect of low-level jaw clenching on temporal summation in healthy volunteers. In 18 healthy volunteers, the pain intensities evoked at the masseter muscle and the hand palm by the first and last stimuli in a train of repeated electrical stimuli (0.3 or 2.0 Hz) were rated using 0-100mm visual analogue scales (VAS), in order to evaluate temporal summation before and after three types of jaw-muscle tasks: low-level jaw clenching, repetitive gum chewing and mandibular rest position. A set of concentric surface electrodes with different diameters (small and large) was used for the electrical stimulation. The temporal summation evoked by the large diameter electrode with 2.0 Hz stimulation decreased significantly both on the masseter and the hand after low-level clenching (P ≤ 0.03), but did not show any significant change after the other tasks (P > 0.23). The VAS score of the first stimulation did not show any significant changes after low-level clenching (P > 0.57). Experimental low-level jaw clenching can inhibit pain sensitivity, especially temporal summation. Low-level jaw clenching can modify pain sensitivity, most likely through the central nervous system. The findings suggest that potential harmful low-level jaw clenching or tooth contacting could continue despite painful symptoms, e.g., temporomandibular disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. 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

  19. 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

  20. 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…

  1. 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.

  2. 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.

  3. Patients with multiple sclerosis present low levels of empathy.

    PubMed

    Almeida, Marcos Barbosa de; Going, Luana Carramilo; Fragoso, Yara Dadalti

    2016-12-01

    This is a single center, cross-sectional study, of 34 patients with MS and 34 matched control subjects. A specific questionnaire (empathy quotient) was used. Patients with MS showed significantly lower levels of empathy. This finding was not correlated with disease duration, degree of disability, drugs for treating MS or lesion load on resonance magnetic imaging. Decreased empathy is a frequent condition in patients with MS and should be addressed in order to diminish the psychosocial burden of this neurological disease.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Exploiting temporal and nonstationary features in breathing sound analysis for multiple obstructive sleep apnea severity classification.

    PubMed

    Kim, Jaepil; Kim, Taehoon; Lee, Donmoon; Kim, Jeong-Whun; Lee, Kyogu

    2017-01-07

    Polysomnography (PSG) is the gold standard test for obstructive sleep apnea (OSA), but it incurs high costs, requires inconvenient measurements, and is limited by a one-night test. Thus, a repetitive OSA screening test using affordable data would be effective both for patients interested in their own OSA risk and in-hospital PSG. The purpose of this research was to develop a four-OSA severity classification model using a patient's breathing sounds. Breathing sounds were recorded from 83 subjects during a PSG test. There was no exclusive experimental protocol or additional recording instruments use throughout the sound recording procedure. Based on the Apnea-Hypopnea Index (AHI), which indicates the severity of sleep apnea, the subjects' sound data were divided into four-OSA severity classes. From the individual sound data, we proposed two novel methods which were not attempted in previous OSA severity classification studies. First, the total transition probability of approximated sound energy in time series, and second, the statistical properties derived from the dimension-reduced cyclic spectral density. In addition, feature selection was conducted to achieve better results with a more relevant subset of features. Then, the classification model was trained using support vector machines and evaluated using leave-one-out cross-validation. The overall results show that our classification model is better than existing multiple OSA severity classification method using breathing sounds. The proposed method demonstrated 79.52% accuracy for the four-class classification task. Additionally, it demonstrated 98.0% sensitivity, 75.0% specificity, and 92.78% accuracy for OSA subject detection classification with AHI threshold 5. The results show that our proposed method can be used as part of an OSA screening test, which can provide the subject with detailed OSA severity results from only breathing sounds.

  9. 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

  10. Temporal Information Entropy of the Blood-Oxygenation Level-Dependent Signals Increases in the Activated Human Primary Visual Cortex.

    PubMed

    DiNuzzo, Mauro; Mascali, Daniele; Moraschi, Marta; Bussu, Giorgia; Maraviglia, Bruno; Mangia, Silvia; Giove, Federico

    2017-01-01

    Time-domain analysis of blood-oxygenation level-dependent (BOLD) signals allows the identification of clusters of voxels responding to photic stimulation in primary visual cortex (V1). However, the characterization of information encoding into temporal properties of the BOLD signals of an activated cluster is poorly investigated. Here, we used Shannon entropy to determine spatial and temporal information encoding in the BOLD signal within the most strongly activated area of the human visual cortex during a hemifield photic stimulation. We determined the distribution profile of BOLD signals during epochs at rest and under stimulation within small (19-121 voxels) clusters designed to include only voxels driven by the stimulus as highly and uniformly as possible. We found consistent and significant increases (2-4% on average) in temporal information entropy during activation in contralateral but not ipsilateral V1, which was mirrored by an expected loss of spatial information entropy. These opposite changes coexisted with increases in both spatial and temporal mutual information (i.e., dependence) in contralateral V1. Thus, we showed that the first cortical stage of visual processing is characterized by a specific spatiotemporal rearrangement of intracluster BOLD responses. Our results indicate that while in the space domain BOLD maps may be incapable of capturing the functional specialization of small neuronal populations due to relatively low spatial resolution, some information encoding may still be revealed in the temporal domain by an increase of temporal information entropy.

  11. Temporal information entropy of the Blood-Oxygenation Level-Dependent signals increases in the activated human primary visual cortex

    NASA Astrophysics Data System (ADS)

    DiNuzzo, Mauro; Mascali, Daniele; Moraschi, Marta; Bussu, Giorgia; Maraviglia, Bruno; Mangia, Silvia; Giove, Federico

    2017-02-01

    Time-domain analysis of blood-oxygenation level-dependent (BOLD) signals allows the identification of clusters of voxels responding to photic stimulation in primary visual cortex (V1). However, the characterization of information encoding into temporal properties of the BOLD signals of an activated cluster is poorly investigated. Here, we used Shannon entropy to determine spatial and temporal information encoding in the BOLD signal within the most strongly activated area of the human visual cortex during a hemifield photic stimulation. We determined the distribution profile of BOLD signals during epochs at rest and under stimulation within small (19-121 voxels) clusters designed to include only voxels driven by the stimulus as highly and uniformly as possible. We found consistent and significant increases (2-4% on average) in temporal information entropy during activation in contralateral but not ipsilateral V1, which was mirrored by an expected loss of spatial information entropy. These opposite changes coexisted with increases in both spatial and temporal mutual information (i.e. dependence) in contralateral V1. Thus, we showed that the first cortical stage of visual processing is characterized by a specific spatiotemporal rearrangement of intracluster BOLD responses. Our results indicate that while in the space domain BOLD maps may be incapable of capturing the functional specialization of small neuronal populations due to relatively low spatial resolution, some information encoding may still be revealed in the temporal domain by an increase of temporal information entropy.

  12. 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.

  13. 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.

  14. Optimizing environmental flows for multiple reaches affected by a multipurpose reservoir system in Taiwan: Restoring natural flow regimes at multiple temporal scales

    NASA Astrophysics Data System (ADS)

    Shiau, Jenq-Tzong; Wu, Fu-Chun

    2013-01-01

    For reservoirs that are operated for multiple purposes such as water supply, flood control, and power generation, any attempts to incorporate environmental flow targets in the reservoir operation rules need to take into account both the human and ecosystem demands. To date, however, none of the reservoir operation schemes that consider environmental flow requirements includes subdaily flow regimes and is able to optimize for multiple reaches. Here, we address the temporal and spatial issues associated with the optimal environmental flow and operation strategies for a multipurpose reservoir system in Taiwan. We propose an environmental flow proportion strategy and three-period release approach, and multireach operation scenarios that simultaneously optimize reservoir performances and environmental flow objectives at subdaily to interannual timescales for a maximum of three connected reaches. Our results imply that taking into account the environmental flow objectives does not necessarily degrade the overall reservoir performance due to the positive effect on flood control, which in turn would compensate for the adverse effects on domestic water supply and hydropower generation. The three-period release approach benefits mainly the subdaily flow regime, while the environmental flow proportion strategy benefits primarily the daily flow regime. Spatially, a mutual exclusion is observed between the reaches above and below a diversion weir, a fact that revises the conventional perception that restoring the flow regimes of a downstream reach would automatically restore those of upstream reaches. An overall evaluation reveals that the three-reach scenario outperforms the two-reach scenarios, which then outperform the one-reach scenarios. The one- or two-reach scenario that incorporates the midstream reach may be taken as an alternative because such scenario would benefit the upstream or downstream reach in addition to the midstream reach.

  15. Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

    PubMed Central

    Loaiza, Vanessa M.; Camos, Valérie

    2016-01-01

    The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects. PMID:27152126

  16. Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

    PubMed

    Loaiza, Vanessa M; Camos, Valérie

    2016-01-01

    The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.

  17. Stochastic modelling of aquifer level temporal fluctuations using the Kalman filter adaptation algorithm and an autoregressive exogenous variable model

    NASA Astrophysics Data System (ADS)

    Varouchakis, Emmanouil

    2017-04-01

    Reliable temporal modelling of groundwater level is significant for efficient water resources management in hydrological basins and for the prevention of possible desertification effects. In this work we propose a stochastic data driven approach of temporal monitoring and prediction that can incorporate auxiliary information. More specifically, we model the temporal (mean annual and biannual) variation of groundwater level by means of a discrete time autoregressive exogenous variable model (ARX model). The ARX model parameters and its predictions are estimated by means of the Kalman filter adaptation algorithm (KFAA). KFAA is suitable for sparsely monitored basins that do not allow for an independent estimation of the ARX model parameters. Three new modified versions of the original form of the ARX model are proposed and investigated: the first considers a larger time scale, the second a larger time delay in terms of the groundwater level input and the third considers the groundwater level difference between the last two hydrological years, which is incorporated in the model as a third input variable. We apply KFAA to time series of groundwater level values from Mires basin in the island of Crete. In addition to precipitation measurements, we use pumping data as exogenous variables. We calibrate the ARX model based on the groundwater level for the years 1981 to 2006 and use it to successfully predict the mean annual and biannual groundwater level for recent years (2007-2010).

  18. 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

  19. 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.

  20. 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.

  1. 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…

  2. 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…

  3. 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.

  4. 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.

  5. 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.

  6. Multiple Intelligence Approach to Curriculum Transaction in Achieving the Educational Objectives at Secondary School Level

    ERIC Educational Resources Information Center

    Francis, Reni

    2012-01-01

    The purpose of this study was to foster learning through the Multiple Intelligence Approach in achieving educational objectives across the levels of Revised Bloom's Taxonomy. Multiple intelligences approach facilitates ways for students by ensuring that curriculum and instruction validate the strengths and build on the assets that students possess…

  7. 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…

  8. 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

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

    PubMed

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

    2017-01-01

    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).

  10. 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.

  11. Featured Article: Serum [Met(5)]-enkephalin levels are reduced in multiple sclerosis and restored by low-dose naltrexone.

    PubMed

    Ludwig, Michael D; Zagon, Ian S; McLaughlin, Patricia J

    2017-09-01

    Low-dose naltrexone is a widely used off-label therapeutic prescribed for a variety of immune-related disorders. The mechanism underlying low-dose naltrexone's efficacy for fatigue, Crohn's disease, fibromyalgia, and multiple sclerosis is, in part, intermittent blockade of opioid receptors followed by upregulation of endogenous opioids. Short, intermittent blockade by naltrexone specifically blocks the opioid growth factor receptor resulting in biofeedback events that increase production of the endogenous opioid growth factor (OGF) (chemically termed [Met(5)]-enkephalin) facilitating interactions between opioid growth factor and opioid growth factor receptor that ultimately, result in inhibited cell proliferation. Preclinical studies have reported that enkephalin levels are deficient in animal models of experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. Our hypothesis is that serum enkephalin levels are diminished in humans with multiple sclerosis and experimental autoimmune encephalomyelitis mice, and that change in serum opioid growth factor levels may serve as a reasonable candidate biomarker for the onset of experimental autoimmune encephalomyelitis and response to therapy. To address this, we designed a two-part study to measure endogenous opioids in multiple sclerosis patients, and to investigate the temporal pattern of decline in serum enkephalin concentrations in mice with chronic progressive experimental autoimmune encephalomyelitis and treated with low-dose naltrexone. For comparison, we investigated whether low-dose naltrexone exposure in normal mice also resulted in altered enkephalin levels. In both animal models, we monitored tactile and heat sensitivity, as well as differential white blood cell counts as indicators of inflammation. Serum [Met(5)]-enkephalin levels were lower in humans with multiple sclerosis relative to non-multiple sclerosis patients, and low-dose naltrexone restored their levels. In experimental

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Effects of Level of Retrieval Success on Recall-Related Frontal and Medial Temporal Lobe Activations

    PubMed Central

    Montaldi, Daniela; Mayes, Andrew R.; Barnes, Anna; Hadley, Donald M.; Patterson, Jim; Wyper, David J.

    2002-01-01

    Brain dedicated single photon emission computed tomography (SPECT) was used to compare the neuroactivation produced by the cued recall of response words in a set of studied word pairs with that produced by the cued retrieval of words semantically related to unstudied stimulus words. Six of the 12 subjects scanned were extensively trained so as to have good memory of the studied pairs and the remaining six were minimally trained so as to have poor memory. When comparing episodic with semantic retrieval, the well-trained subjects showed significant left medial temporal lobe activation, which was also significantly greater than that shown by the poorly trained subjects, who failed to show significant medial temporal lobe activation. In contrast, the poorly trained subjects showed significant bilateral frontal lobe activation, which was significantly greater than that shown by the well-trained subjects who failed to show significant frontal lobe activation. The frontal activations occurred mainly in the dorsolateral region, but extended into the ventrolateral and, to a lesser extent, the frontal polar regions. It is argued that whereas the medial temporal lobe activation increased as the proportion of response words successfully recalled increased, the bilateral frontal lobe activation increased in proportion to retrieval effort, which was greater when learning had been less good. PMID:12446952

  18. A high resolution spatial and temporal multiple Doppler analysis of a microburst and its application to aircraft flight simulation

    NASA Technical Reports Server (NTRS)

    Elmore, K. L.; Mccarthy, J.; Frost, W.; Chang, H. P.

    1986-01-01

    Multiple Doppler radar data collected during the Joint Airport Weather Studies (JAWS) Project is used to synthesize the three-dimensional wind in the region of a microburst. The particular microburst used in this study is the strongest one to date for which three-dimensional winds have been recovered. As a diagnostic tool, a six-DOF numerical aircraft model having characteristics similar to 727 series aircraft is used to investigate jet transport aircraft response to observed microburst winds during simulated approaches and departures. Simple pilot control laws are used to adjust thrust, pitch, roll, and yaw so as to maintain given approach or departure parameters. Generally, when horizontal wind shear along the approach or departure path is 0.01/s or greater, the model is unable to maintain the desired approach path and suffers a significant reduction in climb performance during a go-around or departure. Although the mean wind shear along a path gives a good qualitative measure of the wind shear threat to a jet transport, different paths with similar mean shears can yield markedly different results, as do the same paths through the microburst at different times. These findings are a direct consequence of the fine temporal and spatial scale of microburst winds. During any given modeled aircraft traverse through the region of highest horizontal shear, time variations in the microburst wind field are shown to have an insignificant effect on the modeled flight path. This is because the traverse period is short (30 s) compared to the lifetime of a microburst (300-600 s).

  19. Identifying multiple gestation groups using state-level birth and fetal death certificate data.

    PubMed

    Lazar, Jane; Kotelchuck, Milton; Nannini, Angela; Barger, Mary

    2006-05-01

    Birth and fetal death certificates classify individuals as twins or higher order multiples, but do not identify multiple gestation groups. As a result, multiple gestations are consistently excluded from maternal and child health research studies despite the surge in multiple births since the early 1980s and the health risks associated with them. A standardized methodology for states to identify multiple gestation groups is proposed to allow researchers to account for multiple gestations in analyses, improve the accuracy of the incidence of multiple gestations and further knowledge of the impact of multiple gestations on birth outcomes. Using 3 years of Massachusetts birth and fetal death certificate data from 1998 to 2000 (247,959 births and 1358 fetal deaths), we assigned matching multiple gestation group numbers to records with identical combinations of mother's first name, last name, date of birth, and month of delivery. To validate our methodology, we calculated plurality and compared it to plurality reported on the existing birth and fetal death data. This method correctly identified 10,765 records out of 10,795 validated multiple gestation deliveries (99.8%). Our method identified 71 additional multiple gestation deliveries, which were not identified by the birth and fetal death files. This method resulted in only 4 false positives and 51 false negatives over 3 years. This algorithm provides much needed information on multiple gestation groupings, and as an additional benefit, improves the identification of multiple gestation deliveries. This method has proven easy to use, employs state-level data, and offers numerous new analytic opportunities.

  20. Obesity and chronic stress are able to desynchronize the temporal pattern of serum levels of leptin and triglycerides.

    PubMed

    de Oliveira, Carla; Scarabelot, Vanessa Leal; de Souza, Andressa; de Oliveira, Cleverson Moraes; Medeiros, Liciane Fernandes; de Macedo, Isabel Cristina; Marques Filho, Paulo Ricardo; Cioato, Stefania Giotti; Caumo, Wolnei; Torres, Iraci L S

    2014-01-01

    Disruption of the circadian system can lead to metabolic dysfunction as a response to environmental alterations. This study assessed the effects of the association between obesity and chronic stress on the temporal pattern of serum levels of adipogenic markers and corticosterone in rats. We evaluated weekly weight, delta weight, Lee index, and weight fractions of adipose tissue (mesenteric, MAT; subcutaneous, SAT; and pericardial, PAT) to control for hypercaloric diet-induced obesity model efficacy. Wistar rats were divided into four groups: standard chow (C), hypercaloric diet (HD), stress plus standard chow (S), and stress plus hypercaloric diet (SHD), and analyzed at three time points: ZT0, ZT12, and ZT18. Stressed animals were subjected to chronic stress for 1h per day, 5 days per week, during 80 days. The chronic exposure to a hypercaloric diet was an effective model for the induction of obesity and metabolic syndrome, increasing delta weight, Lee index, weight fractions of adipose tissue, and triglycerides and leptin levels. We confirmed the presence of a temporal pattern in the release of triglycerides, corticosterone, leptin, and adiponectin in naïve animals. Chronic stress reduced delta weight, MAT weight, and levels of triglycerides, total cholesterol, and leptin. There were interactions between chronic stress and obesity and serum total cholesterol levels, between time points and obesity and adiponectin and corticosterone levels, and between time points and chronic stress and serum leptin levels. In conclusion, both parameters were able to desynchronize the temporal pattern of leptin and triglyceride release, which could contribute to the development of metabolic diseases such as obesity and metabolic syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. 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.

  2. 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

  3. Using Multiple FPGA Architectures for Real-time Processing of Low-level Machine Vision Functions

    Treesearch

    Thomas H. Drayer; William E. King; Philip A. Araman; Joseph G. Tront; Richard W. Conners

    1995-01-01

    In this paper, we investigate the use of multiple Field Programmable Gate Array (FPGA) architectures for real-time machine vision processing. The use of FPGAs for low-level processing represents an excellent tradeoff between software and special purpose hardware implementations. A library of modules that implement common low-level machine vision operations is presented...

  4. Acceptance and Accuracy of Multiple Choice, Confidence-Level, and Essay Question Formats for Graduate Students

    ERIC Educational Resources Information Center

    Swartz, Stephen M.

    2006-01-01

    The confidence level (information-referenced testing; IRT) design is an attempt to improve upon the multiple choice format by allowing students to express a level of confidence in the answers they choose. In this study, the author evaluated student perceptions of the ease of use and accuracy of and general preference for traditional multiple…

  5. 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

  6. 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.

  7. Level of sFas/APO 1 in serum and cerebrospinal fluid in multiple sclerosis.

    PubMed

    Mahovic, Darija; Petravic, Damir; Petelin, Zeljka; Zurak, Niko; Horvat, Gordana; Hajnsek, Sanja

    2004-06-01

    The aim of the study was to measure sFas/APO 1 serum and cerebrospinal fluid (CSF) levels in patients with relapsing-remitting multiple sclerosis (MS) during relapses, as an index of inhibition of apoptosis of activated lymphocytes in eight patients with clinically definite multiple sclerosis, and 12 healthy controls. The level of serum and CSF sFas/APO 1 was determined by commercially available enzyme-linked immunosorbent assay (ELISA) kits. No significant differences were detected in the sFas/APO 1 serum level between patients and controls, but the levels in CSF was lower in the former. Our results suggest the possibility of Fas mediated apoptosis as a contributing factor in the pathogenesis of multiple sclerosis.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. IL-21 and other serum proinflammatory cytokine levels in patients with multiple myeloma at diagnosis.

    PubMed

    Mehtap, O; Atesoglu, E B; Tarkun, P; Hacihanefioglu, A; Dolasik, I; Musul, M M

    2014-01-01

    IL-6, IL1-β, TNF-α and IL-21 have been identified in the growth, progression and dissemination of multiple myeloma. To dte, there is no published data about serum levels of IL-21 in patients with multiple myeloma. In the present study we have investigated circulating levels of cytokines, such as IL-6, IL-1β, TNF-α, IL-21 and the association of these levels with the disease stage in newly diagnosed multiple myeloma patients. Twenty healthy controls and 44 newly diagnosed multiple myeloma patients were evaluated. Patients were classified according to Durie-Salmon criteria, international staging system (ISS) and bone disease. Quantification of cytokine levels in serum were performed by using ELISA. The levels of cytokines in patients' serum are found elevated than healthy controls. However, only the serum levels of IL-1β and TNF-α were found statistically significant. TNF-α levels of patients with ISS stage 3 were significantly higher than patients with ISS stage 1 and 2 (P 0.000). IL-1β was significantly elevated in advanced stage patients (stage II-III) (P 0.040). There was no correlation between IL-1β, TNF-α, IL-21 levels and bone lesions. IL-6 levels were significantly elevated who have at least three visible lytic bone lesions and/or bone fracture in comparison to patients who have one or two visible or no visible lytic bone lesions (P 0.048). It appears that there is no association of serum IL-21 level with multiple myeloma in contrast to the other cytokines such as IL-6, IL-1β, TNF-α.

  13. Sea-level rise impacts on the temporal and spatial variability of extreme water levels: A case study for St. Peter-Ording, Germany

    NASA Astrophysics Data System (ADS)

    Santamaria-Aguilar, S.; Arns, A.; Vafeidis, A. T.

    2017-04-01

    Both the temporal and spatial variability of storm surge water level (WL) curves are usually not taken into account in flood risk assessments as observational data are often scarce. In addition, sea-level rise (SLR) can further affect the variability of WLs. We analyze the temporal and spatial variability of the WL curve of 75 historical storm surge events that have been numerically simulated for St. Peter-Ording at the German North Sea coast, considering the effects induced by three SLR scenarios (RCP 4.5, RCP 8.5, and a RCP 8.5 high end scenario). We assess potential impacts of these scenarios on two parameters related to flooding: overflow volumes and fullness. Our results indicate that due to both the temporal and spatial variability of those events the resulting overflow volume can be two or even three times greater. We observe a steepening of the WL curve with an increase of the tidal range under the three SLR scenarios, although SLR induced effects are relatively higher for the RCP 4.5. The steepening of the WL curve with SLR produces a reduction of the fullness, but the changes in overflow volumes also depend on the magnitude of the storm surge event.

  14. 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.

  15. Tryptase levels in children presenting with anaphylaxis: Temporal trends and associated factors.

    PubMed

    De Schryver, Sarah; Halbrich, Michelle; Clarke, Ann; La Vieille, Sebastien; Eisman, Harley; Alizadehfar, Reza; Joseph, Lawrence; Morris, Judy; Ben-Shoshan, Moshe

    2016-04-01

    The diagnosis of anaphylaxis currently relies on suggestive clinical history after exposure to a potential triggering factor because no reliable diagnostic marker is available to confirm the diagnosis. We aimed to evaluate tryptase levels in children with anaphylaxis and to examine predictors of elevated tryptase level (defined as ≥11.4 μg/L during reaction and for those with a baseline level, defined as a reaction level of at least 2 ng/mL + 1.2 × [postreaction tryptase level]). Children presenting with anaphylaxis to the Montreal Children's Hospital were recruited over a 4-year period. Symptoms, triggers, and management of anaphylaxis were documented. Levels during the reaction and approximately 9 months after the reaction were compared on the basis of paired means using the t distribution. Multivariate linear and logistic regressions were used to evaluate the association between tryptase levels and risk factors. Over a 4-year period, 203 children had serum tryptase levels measured. Among these, 39 children (19.2%; 95% CI, 14.1%-25.4%) had elevated levels. Only severe reactions were associated with reaction levels of 11.4 μg/L or more (odds ratio, 6.5; 95% CI, 2.2-19.0). Milk-induced anaphylaxis and severe reactions were more likely associated with increased tryptase levels (beta-adjusted, 4.0; 95% CI, 0.95-7.0, and 7.5; 95% CI, 4.8-10.3, respectively). Reaction levels exceeding the threshold level of 2 ng/mL + 1.2 × (postreaction tryptase level) detected most of the anaphylactic reactions, particularly if baseline levels were taken within 2 months of the reaction. Tryptase levels are particularly useful for the diagnosis of severe and/or milk-induced anaphylaxis. Assessing the difference between reaction and postreaction tryptase levels may improve diagnostic sensitivity. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  16. Dual-temporal resolution dynamic contrast-enhanced MRI protocol for blood-brain barrier permeability measurement in enhancing multiple sclerosis lesions.

    PubMed

    Jelescu, I O; Leppert, I R; Narayanan, S; Araújo, D; Arnold, D L; Pike, G B

    2011-06-01

    To design a more accurate and reproducible technique for the measurement of blood-brain barrier (BBB) permeability in gadolinium-enhancing multiple sclerosis (MS) lesions. Four MS patients were scanned using a new dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) protocol based on an uninterrupted two-part acquisition consisting of an initial part at high temporal and low spatial resolutions and a second part at low temporal and high spatial resolutions. The method preserves both the high spatial resolution needed for the often small size of lesions and the high temporal resolution required during the first minute after injection to sufficiently sample the first-pass bolus. Simulations compared the performance of this new protocol with the conventional one at low temporal and high spatial resolutions throughout. The BBB permeability estimates changed by up to 33% between the two protocols. The new protocol led to simulated error on K(trans) of 7%-10%, versus 7%-30% with the conventional protocol, and was more robust with respect to offsets between acquisition and injection start times, differences in shape of the first-pass peak, and permeability values. The dual-temporal resolution protocol produces improved BBB permeability estimates and provides a more complete view of active inflammatory MS lesion pathology. Copyright © 2011 Wiley-Liss, Inc.

  17. Low levels of maximal aerobic power impair the profile of mood state in individuals with temporal lobe epilepsy.

    PubMed

    Vancini, Rodrigo Luiz; Lira, Claudio Andre Barbosa de; Andrade, Marília dos Santos; Lima, Cristiano de; Arida, Ricardo Mario

    2015-01-01

    To investigate the correlation between cardiorespiratory fitness and mood state in individuals with temporal lobe epilepsy (TLE). Individuals with TLE (n = 20) and healthy control subjects (C, n = 20) were evaluated. Self-rating questionnaires were used to assess mood (POMS) and habitual physical activity (BAECKE). Cardiorespiratory fitness was evaluated by a maximal incremental test. People with TLE presented lower cardiorespiratory fitness; higher levels of mood disorders; and lower levels of vigor when compared to control health subjects. A significant negative correlation was observed between the levels of tension-anxiety and maximal aerobic power. Low levels of cardiorespiratory fitness may modify the health status of individuals with TLE and it may be considered a risk factor for the development of mood disorders.

  18. 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.

  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 Central

    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. PMID:25789612

  20. VEGF levels in humans and animal models with RDS and BPD: temporal relationships.

    PubMed

    Meller, Stephanie; Bhandari, Vineet

    2012-05-01

    Respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) contribute significantly to neonatal morbidity and mortality. Pulmonary function depends on the interaction between alveolar microvasculature and airspace development. While it has been shown in various animal models that vascular endothelial growth factor (VEGF) and its receptors increase in normal animal lung development, its pathophysiological role in neonatal respiratory failure is not yet entirely clear. Current animal and human studies exhibit controversial results. Though animal models are invaluable tools in the study of human lung disease, inherent differences in physiology mandate clarification of the timing of these studies to ensure that they appropriately correlate with the human stages of lung development. The purpose of this review article is to highlight the importance of considering the temporal relationship of VEGF and lung development in human neonates and developmentally-appropriate animal models with RDS and BPD.

  1. 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

  2. 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.

  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. Informing the operations of water reservoirs over multiple temporal scales by direct use of hydro-meteorological data

    NASA Astrophysics Data System (ADS)

    Denaro, Simona; Anghileri, Daniela; Giuliani, Matteo; Castelletti, Andrea

    2017-05-01

    Water reservoir systems may become more adaptive and reliable to external changes by enlarging the information sets used in their operations. Models and forecasts of future hydro-climatic and socio-economic conditions are traditionally used for this purpose. Nevertheless, the identification of skillful forecasts and models might be highly critical when the system comprises several processes with inconsistent dynamics (fast and slow) and disparate levels of predictability. In these contexts, the direct use of observational data, describing the current conditions of the water system, may represent a practicable and zero-cost alternative. This paper contrasts the relative contribution of state observations and perfect forecasts of future water availability in improving multipurpose water reservoirs operation over short- and long-term temporal scales. The approach is demonstrated on the snow-dominated Lake Como system, operated for flood control and water supply. The Information Selection Assessment (ISA) framework is adopted to retrieve the most relevant information to be used for conditioning the operations. By explicitly distinguishing between observational dataset and future forecasts, we quantify the relative contribution of current water system state estimates and perfect streamflow forecasts in improving the lake regulation with respect to both flood control and water supply. Results show that using the available observational data capturing slow dynamic processes, particularly the snow melting process, produces a 10% improvement in the system performance. This latter represents the lower bound of the potential improvement, which may increase to the upper limit of 40% in case skillful (perfect) long-term streamflow forecasts are used.

  5. 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

  6. 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.

  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. 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.

  9. 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.

  10. Spatial and temporal determinants of A-weighted and frequency specific sound levels-An elastic net approach.

    PubMed

    Walker, Erica D; Hart, Jaime E; Koutrakis, Petros; Cavallari, Jennifer M; VoPham, Trang; Luna, Marcos; Laden, Francine

    2017-11-01

    Urban sound levels are a ubiquitous environmental stressor and have been shown to be associated with a wide variety of health outcomes. While much is known about the predictors of A-weighted sound pressure levels in the urban environment, far less is known about other frequencies. To develop a series of spatial-temporal sound models to predict A-weighted sound pressure levels, low, mid, and high frequency sound for Boston, Massachusetts. Short-term sound levels were gathered at n = 400 sites from February 2015 - February 2016. Spatial and meteorological attributes at or near the sound monitoring site were obtained using publicly available data and a portable weather station. An elastic net variable selection technique was used to select predictors of A-weighted, low, mid, and high frequency sound. The final models for low, mid, high, and A-weighted sound levels explained 59 - 69% of the variability in each measure. Similar to other A-weighted models, our sound models included transportation related variables such as length of roads and bus lines in the surrounding area; distance to road and rail lines; traffic volume, vehicle mix, residential and commercial land use. However, frequency specific models highlighted additional predictors not included in the A-weighted model including temperature, vegetation, impervious surfaces, vehicle mix, and density of entertainment establishments and restaurants. Building spatial temporal models to characterize sound levels across the frequency spectrum using an elastic net approach can be a promising tool for noise exposure assessments within the urban soundscape. Models of sound's character may give us additional important sound exposure metrics to be utilized in epidemiological studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Changes in B- and T-lymphocyte and chemokine levels with rituximab treatment in multiple sclerosis.

    PubMed

    Piccio, Laura; Naismith, Robert T; Trinkaus, Kathryn; Klein, Robyn S; Parks, Becky J; Lyons, Jeri A; Cross, Anne H

    2010-06-01

    B cells are implicated in the pathogenesis of multiple sclerosis. A beneficial effect of B-cell depletion using rituximab has been shown, but the complete mechanism of action for this drug is unclear. To determine the relationship between T and B cells and changes in cerebrospinal fluid (CSF) chemokine levels with rituximab, a monoclonal antibody that targets CD20. Phase 2 trial of rituximab as an add-on therapy. The John L. Trotter Multiple Sclerosis Center, Washington University. Participants and Intervention Thirty subjects who had relapsing-remitting multiple sclerosis with clinical and magnetic resonance imaging activity despite treatment with an immunomodulatory drug received 4 weekly doses of rituximab (375 mg/m(2)). Lumbar puncture was performed before and after rituximab infusions in 26 subjects. Levels of B and T lymphocytes in the CSF were enumerated by flow cytometry, and chemoattractant levels were measured by enzyme-linked immunosorbent assay. After rituximab administration, CSF B-cell levels were decreased or undetectable in all subjects, and CSF T-cell levels were reduced in 21 subjects (81%). The mean reduction in CSF cellularity was 95% for B cells and 50% for T cells. After rituximab infusion, CSF CXCL13 and CCL19 levels decreased (P = .002 and P = .03, respectively). The proportional decline in CSF T-cell levels correlated with the proportional decrease in CXCL13 levels (r = 0.45; P = .03), suggesting a possible relationship. The CSF IgG index, IgG concentration, and oligoclonal band number were unchanged following treatment. In subjects with multiple sclerosis, B cells are critical for T-cell trafficking into the central nervous system and may alter the process by influencing chemokine production within the central nervous system.

  12. 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…

  13. 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…

  14. Beyond the Basics: Preschool Children Label Objects Flexibly at Multiple Hierarchical Levels.

    ERIC Educational Resources Information Center

    Waxman, Sandra R.; Hatch, Thomas

    1992-01-01

    Examines (1) preschool children's production of multiple, hierarchically related labels; (2) the pragmatic consequences of the inherent asymmetry of inclusion relations; and (3) the influence of morphology (modifier plus noun constructions vs. simple lexemes) at the subordinate level. Performance shows an inability to label objects flexibly at…

  15. 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…

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

    ERIC Educational Resources Information Center

    Graesser, Arthur C.; McNamara, Danielle S.; Cai, Zhiqiang; 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…

  17. Platelet monoamine oxidase activity levels in subgroups of alcoholics: diagnostic, temporal, and clinical correlates.

    PubMed

    Anthenelli, R M; Smith, T L; Craig, C E; Tabakoff, B; Schuckit, M A

    1995-09-15

    Platelet monoamine oxidase (MAO) activity levels were measured in 47 male inpatient alcoholics to determine whether this biological marker might be useful in differentiating subtypes of alcoholics. Of the subgrouping methods tested, only type 2 alcoholics defined by the criteria of Gilligan et al had significantly lower platelet MAO activity than type 1 alcoholics at intake, but this finding was not stable over time in a subset of subjects. Neither separating male veteran alcoholics into either of two other variations of the type 1/type 2 subtypes, nor classifying the sample into primary alcoholics versus primary ASPD with secondary alcoholism categories, yielded significant differences between subgroups. Generally, enzyme activity levels (Vmax) were higher about 10 days after stopping drinking compared to platelet MAO values determined in thrombocytes obtained after approximately 4 weeks abstinence; these levels remained relatively stable 3 months later in a cohort of subjects. Tobacco smoking was significantly negatively correlated to platelet MAO activity levels.

  18. 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.

  19. 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

  20. Octopaminergic modulation of temporal frequency tuning of a fly visual motion-sensitive neuron depends on adaptation level

    PubMed Central

    Lüders, Janina; Kurtz, Rafael

    2015-01-01

    Several recent studies in invertebrates as well as vertebrates have demonstrated that neuronal response characteristics of sensory neurons can be profoundly affected by an animal’s locomotor activity. The functional consequences of such state-dependent modulation have been a matter of intense debate. In flies, a particularly interesting finding was that tethered walking or flying causes not only general response enhancement of visual motion-sensitive neurons, but also broadens their temporal frequency tuning towards higher values. However, in other studies such state-dependent alterations of neuronal tuning functions were not found. We hypothesize that these discrepancies were due to different adaptation levels of the motion-sensitive neurons, resulting from the use of different stimulation protocols. This is plausible, because the strength of adaptation during ongoing stimulation was shown to be affected by chlordimeform (CDM), an agonist of the insect neuromodulator octopamine, which mediates state-dependent modulation. Our results show that CDM causes broadening of the temporal frequency tuning of the blowfly’s visual motion-sensitive H1 neuron only in the adapted state, but not prior to the presentation of adapting motion. Thus, our study indicates that seemingly conflicting results on the locomotor state-dependence of neuronal tuning functions are consistent when considering the neurons’ adaptation level. Moreover, it demonstrates that stimulation history has to be considered when the significance of state-dependent modulation of sensory processing is interpreted. PMID:26074790

  1. Temporal trends in metal levels in eggs of the endangered roseate tern (Sterna dougallii) in New York

    SciTech Connect

    Gochfeld, M. |; Burger, J. |

    1998-04-01

    Female birds sequester certain organic and inorganic compounds in their eggs which have been widely used as a bioindicator for examining the body burdens of contaminants and therefore the temporal and spatial trends of the contaminants in the environment. The same analyses can also reflect the status or vulnerability of the indicator species. Extensive bridge deleading activities in the New York Bight (Cape May to Montauk) in the early 1990s coincided with a long-term study of the endangered roseate tern (Sterna dougallii) on Long Island, New York, affording the opportunity to test the utility of such fish-eating species as bioindicators of lead contamination, as well as the potential impact on the bird population itself. In this paper the authors test the null hypothesis that there were no temporal trends between 1989 and 1994 in metal levels in eggs of roseate terns nesting at Cedar Beach, Long Island, where the birds have been declining since the late 1980s. The authors report levels and trends for cadmium, chromium, manganese, mercury, and selenium as well as lead in abandoned eggs collected each year.

  2. Temporal trends in BMI in Argentina by socio-economic position and province-level economic development, 2005-2009.

    PubMed

    Christine, Paul J; Diez Roux, Ana V; Wing, Jeffrey J; Alazraqui, Marcio; Spinelli, Hugo

    2015-04-01

    We investigated temporal trends in BMI, and assessed hypothesized predictors of trends including socio-economic position (SEP) and province-level economic development, in Argentina. Using multivariable linear regression, we evaluated cross-sectional patterning and temporal trends in BMI and examined heterogeneity in these associations by SEP and province-level economic development with nationally representative samples from Argentina in 2005 and 2009. We calculated mean annual changes in BMI for men and women to assess secular trends. Women, but not men, exhibited a strong cross-sectional inverse association between SEP and BMI, with the lowest-SEP women having an average BMI 2.55 kg/m(2) greater than the highest-SEP women. Analysis of trends revealed a mean annual increase in BMI of 0.19 kg/m(2) and 0.15 kg/m(2) for women and men, respectively, with slightly greater increases occurring in provinces with greater economic growth. No significant heterogeneity in trends existed by individual SEP. BMI is increasing rapidly over time in Argentina irrespective of various sociodemographic characteristics. Higher BMI remains more common in women of lower SEP compared with those of higher SEP.

  3. Temporal Trends and Determinants of Longitudinal Change in 25-Hydroxyvitamin D and Parathyroid Hormone Levels

    PubMed Central

    Berger, Claudie; Greene-Finestone, Linda S; Langsetmo, Lisa; Kreiger, Nancy; Joseph, Lawrence; Kovacs, Christopher S.; Richards, J. Brent; Hidiroglou, Nick; Sarafin, Kurtis; Davison, K. Shawn; Adachi, Jonathan D.; Brown, Jacques; Hanley, David A.; Prior, Jerilynn C.; Goltzman, David

    2016-01-01

    Vitamin D is essential for facilitating calcium absorption and preventing increases in parathyroid hormone (PTH), which can augment bone resorption. Our objectives were to examine serum levels of 25-hydroxyvitamin D [25(OH)D] and PTH, and factors related to longitudinal change in a population-based cohort. This is the first longitudinal population-based study looking at PTH and 25(OH)D levels. We analyzed 3896 blood samples from 1896 women and 829 men in the Canadian Multicentre Osteoporosis Study over a 10-year period starting in 1995 to 1997. We fit hierarchical models with all available data and adjusted for season. Over 10 years, vitamin D supplement intake increased by 317 (95% confidence interval [CI] 277 to 359) IU/day in women and by 193 (135 to 252) IU/day in men. Serum 25(OH)D (without adjustment) increased by 9.3 (7.3 to 11.4) nmol/L in women and by 3.5 (0.6 to 6.4) nmol/L in men but increased by 4.7 (2.4 to 7.0) nmol/L in women and by 2.7 (−0.6 to 6.2) nmol/L in men after adjustment for vitamin D supplements. The percentage of participants with 25(OH)D levels <50 nmol/L was 29.7% (26.2 to 33.2) at baseline and 19.8% (18.0 to 21.6) at year 10 follow-up. PTH decreased over 10 years by 7.9 (5.4 to 11.3) pg/mL in women and by 4.6 (0.2 to 9.0) pg/mL in men. Higher 25(OH)D levels were associated with summer, younger age, lower body mass index (BMI), regular physical activity, sun exposure, and higher total calcium intake. Lower PTH levels were associated with younger age and higher 25(OH)D levels in both women and men and with lower BMI and participation in regular physical activity in women only. We have observed concurrent increasing 25(OH)D levels and decreasing PTH levels over 10 years. Secular increases in supplemental vitamin D intake influenced both changes in serum 25(OH)D and PTH levels. PMID:22407786

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Spatial, spectral and temporal patterns of tropical forest cover change as observed with multiple scales of optical satellite data.

    Treesearch

    D.J. Hayes; W.B. Cohen

    2006-01-01

    This article describes the development of a methodology for scaling observations of changes in tropical forest cover to large areas at high temporal frequency from coarse-resolution satellite imagery. The approach for estimating proportional forest cover change as a continuous variable is based on a regression model that relates multispectral, multitemporal Moderate...

  10. 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.

  11. 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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. 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.

  13. 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.

  14. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 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.

  17. Spatial-temporal models for improved county-level annual estimates

    Treesearch

    Francis Roesch

    2009-01-01

    The consumers of data derived from extensive forest inventories often seek annual estimates at a finer spatial scale than that which the inventory was designed to provide. This paper discusses a few model-based and model-assisted estimators to consider for county level attributes that can be applied when the sample would otherwise be inadequate for producing low-...

  18. 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.

  19. 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

  20. Effect of exit spacing in a multiple-jet nozzle on noise levels at audible frequencies.

    PubMed

    Sheen, Shaw-Ching

    2011-06-01

    This work investigated the effect of exit spacing on audible noise levels generated by a multiple-jet nozzle, which replaces the single exit in a common nozzle with multiple smaller exits to reduce the risk of hearing damage. Sound measurements and 1/3-octave band analyses were performed for multiple-jet nozzles with varying exit diameters and exit spacings. Results show that the effect of exit spacing is evident below a certain frequency range, which falls in the relatively low frequency part of the sound spectrum. The frequency range affected by exit spacing was found to extend to higher frequencies if the exits were more closely distributed. It was found that decreasing the exit spacing will shift the sound spectrum toward the low frequency side, which has been shifted toward the high frequency side by the use of smaller exits, and will increase the sound pressure levels at lower frequencies. When the exits were confined in a limited area, to maintain a constant total exit area, decreasing the exit diameters will increase the number of exits and reduce the exit spacing. Smaller exit diameters will increase the sound frequency and shift the sound spectrum toward the high frequency side, while decreased exit spacing has the opposite effect of shifting the spectrum toward the low frequency side. Due to these two opposing effects, for a multiple-jet nozzle with a limited size, there is an optimum exit diameter that, depending on the method used to evaluate the overall sound pressure level, generates the lowest sound pressure levels in the audible frequency range. If there is no limit to its physical size, a multiple-jet nozzle should avoid using an exit spacing that is too small. The minimum exit spacing required to avoid the adverse effects of a small exit spacing requires more extensive studies.

  1. 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.

  2. Spatial and temporal variability of sea level rise hot spots over the eastern United States

    NASA Astrophysics Data System (ADS)

    Valle-Levinson, Arnoldo; Dutton, Andrea; Martin, Jonathan B.

    2017-08-01

    Regional sea level rise (SLR) acceleration during the past few decades north of Cape Hatteras has commonly been attributed to weakening Atlantic Meridional Overturning Circulation, although this causal link remains debated. In contrast to this pattern, we demonstrate that SLR decelerated north of Cape Hatteras and accelerated south of the Cape to >20 mm/yr, > 3 times the global mean values from 2011 to 2015. Tide gauge records reveal comparable short-lived, rapid SLR accelerations (hot spots) that have occurred repeatedly over 1500 km stretches of the coastline during the past 95 years, with variable latitudinal position. Our analysis indicates that the cumulative (time-integrated) effects of the North Atlantic Oscillation determine the latitudinal position of these SLR hot spots, while a cumulative El Niño index is associated with their timing. The superposition of these two ocean-atmospheric processes accounts for 87% of the variance in the spatiotemporal pattern of intradecadal sea level oscillations.

  3. 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.

  4. 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.

  5. Levels of uninvolved immunoglobulins predict clinical status and progression-free survival for multiple myeloma patients.

    PubMed

    Harutyunyan, Nika M; Vardanyan, Suzie; Ghermezi, Michael; Gottlieb, Jillian; Berenson, Ariana; Andreu-Vieyra, Claudia; Berenson, James R

    2016-07-01

    Multiple myeloma (MM) is characterized by the enhanced production of the same monoclonal immunoglobulin (M-Ig or M protein). Techniques such as serum protein electrophoresis and nephelometry are routinely used to quantify levels of this protein in the serum of MM patients. However, these methods are not without their shortcomings and problems accurately quantifying M proteins remain. Precise quantification of the types and levels of M-Ig present is critical to monitoring patient response to therapy. In this study, we investigated the ability of the HevyLite (HLC) immunoassay to correlate with clinical status based on levels of involved and uninvolved antibodies. In our cohort of MM patients, we observed that significantly higher ratios and greater differences of involved HLC levels compared to uninvolved HLC levels correlated with a worse clinical status. Similarly, higher absolute levels of involved HLC antibodies and lower levels of uninvolved HLC antibodies also correlated with a worse clinical status and a shorter progression-free survival. These findings suggest that the HLC assay is a useful and a promising tool for determining the clinical status and survival time for patients with multiple myeloma. © 2016 John Wiley & Sons Ltd.

  6. 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

  7. 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.

  8. Observed cloud level circulation on Venus - Temporal variations and solar longitude dependence

    NASA Technical Reports Server (NTRS)

    Limaye, Sanjay Shridhar

    1987-01-01

    This paper presents data on the atmospheric circulation of Venus, obtained by the Mariner 10 (1974) and Pioneer (1979-1986) observations. The results yielded evidence of relatively stable zonal circulation at the cloud level. On the other hand, changes on a yearly time scale appear in both the zonal and the meridional components of motion. Solar thermal tides and large-scale planetary waves are also seen in averaged zonal and meridional cloud motions. The relationship between the large-scale circulation and global cloud structure is discussed.

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

    PubMed

    Al-Khamis, Fahd A

    2016-01-01

    To determine the relationship between Vitamin B12 levels and thyroid hormones in patients with multiple sclerosis (MS). 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. 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). 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.

  10. 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

  11. 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.

  12. Multiple-Objective Optimal Designs for Studying the Dose Response Function and Interesting Dose Levels

    PubMed Central

    Hyun, Seung Won; Wong, Weng Kee

    2016-01-01

    We construct an optimal design to simultaneously estimate three common interesting features in a dose-finding trial with possibly different emphasis on each feature. These features are (1) the shape of the dose-response curve, (2) the median effective dose and (3) the minimum effective dose level. A main difficulty of this task is that an optimal design for a single objective may not perform well for other objectives. There are optimal designs for dual objectives in the literature but we were unable to find optimal designs for 3 or more objectives to date with a concrete application. A reason for this is that the approach for finding a dual-objective optimal design does not work well for a 3 or more multiple-objective design problem. We propose a method for finding multiple-objective optimal designs that estimate the three features with user-specified higher efficiencies for the more important objectives. We use the flexible 4-parameter logistic model to illustrate the methodology but our approach is applicable to find multiple-objective optimal designs for other types of objectives and models. We also investigate robustness properties of multiple-objective optimal designs to mis-specification in the nominal parameter values and to a variation in the optimality criterion. We also provide computer code for generating tailor made multiple-objective optimal designs. PMID:26565557

  13. 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

  14. 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.

  15. 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

  16. Physicians, clinics, and neighborhoods: multiple levels of influence on colorectal cancer screening.

    PubMed

    Pruitt, Sandi L; Leonard, Tammy; Zhang, Song; Schootman, Mario; Halm, Ethan A; Gupta, Samir

    2014-07-01

    We (i) described variability in colorectal cancer (CRC) test use across multiple levels, including physician, clinic, and neighborhood; and (ii) compared the performance of novel cross-classified models versus traditional hierarchical models. We examined multilevel variation in CRC test use among patients not up-to-date with screening in a large, urban safety net health system (2011-2012). Outcomes included: (i) fecal occult blood test (FOBT) or (ii) colonoscopy and were ascertained using claims data during a 1-year follow-up. We compared Bayesian (i) cross-classified four-level logistic models nesting patients within separate, nonoverlapping "levels" (physicians, clinics, and census tracts) versus (ii) three hierarchical two-level models using deviance information criterion. Models were adjusted for covariates (patient sociodemographic factors, driving time to clinic, and census tract poverty rate). Of 3,195 patients, 157 (4.9%) completed FOBT and 292 (9.1%) completed colonoscopy during the study year. Patients attended 19 clinics, saw 177 physicians, and resided in 332 census tracts. Significant variability was observed across all levels in both hierarchical and cross-classified models that was unexplained by measured covariates. For colonoscopy, variance was similar across all levels. For FOBT, physicians, followed by clinics, demonstrated the largest variability. Model fit using cross-classified models was superior or similar to 2-level hierarchical models. Significant and substantial variability was observed across neighborhood, physician, and clinic levels in CRC test use, suggesting the importance of factors at each of these levels on CRC testing. Future multilevel research and intervention should consider the simultaneous influences of multiple levels, including clinic, physician, and neighborhood. ©2014 American Association for Cancer Research.

  17. Temporal variation in the biochemical ecology of lower trophic levels in the Northern California Current

    NASA Astrophysics Data System (ADS)

    Miller, J. A.; Peterson, W. T.; Copeman, L. A.; Du, X.; Morgan, C. A.; Litz, M. N. C.

    2017-06-01

    There is strong correlative evidence that variation in the growth and survival of secondary consumers is related to the copepod species composition within the Northern California Current. Potential mechanisms driving these correlations include: (1) enhanced growth and survival of secondary consumers when lipid-rich, boreal copepod species are abundant, with cascading effects on higher trophic levels; (2) the regulation of growth and condition of primary and secondary consumers by the relative proportion of certain essential fatty acids (FAs) in primary producers; or (3) a combination of these factors. Disentangling the relative importance of taxonomic composition, lipid quantity, and FA composition on the nutritional quality of copepods requires detailed information on both the consumer and primary producers. Therefore, we collected phytoplankton and copepods at an oceanographic station for 19 months and completed species community analyses and generated detailed lipid profiles, including lipid classes and FAs, for both groups. There was strong covariation between species and biochemistry within and across trophic levels and distinct seasonal differences. The amount of total lipid within both the phytoplankton and copepod communities was twice as high in spring and summer than in fall and winter, and certain FAs, such as diatom indicators 20:5ω3 and 16:1ω7, comprised a greater proportion of the FA pool in spring and summer. Indicators of bacterial production within the copepod community were proportionally twice as high during fall and winter than spring and summer. Seasonal transitions in copepod FA composition were consistently offset from transitions in copepod species composition by approximately two weeks. The timing of the seasonal transition in copepod FAs reflected seasonal shifts in the species composition and/or biochemistry of primary producers more than seasonal shifts in the copepod species composition. These results emphasize the importance of

  18. 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.

  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. High apelin levels could be used as a diagnostic marker in multiple myeloma: A comparative study.

    PubMed

    Maden, Muhammet; Pamuk, Omer Nuri; Pamuk, Gulsum Emel

    2016-01-01

    Apelin/APJ system regulates angiogenesis and is overexpressed in some malignancies. Apelin can induce lymphangiogenesis and lymph node metastasis. We evaluated apelin levels in multiple myeloma (MM) and non-Hodgkin lymphoma (NHL); and analyzed the association between apelin levels and clinical findings. We included consecutive 29 MM, 31 NHL patients, and 19 healthy controls. Patients' demographic and clinical features, treatment modalities, and responses were recorded from hospital records. Plasma apelin was determined by enzyme-linked immunosorbent assay (ELISA). MM patients had significantly higher plasma apelin level than NHL and healthy control groups (p< 0.001). Apelin level in NHL group was similar to controls (p> 0.05). ROC curve analysis showed that the area under the curve value for apelin level in MM was 0.842 ng/ml (95%CI: 0.739-0.945, p< 0.001). Plasma apelin level ≥ 0.827 ng/ml had 76% sensitivity and 86% specificity for the diagnosis of MM. Multivariate Cox regression analysis showed that MM patients with high apelin level had better prognosis and patients with advanced stage of disease (ISS-3) had significantly poor prognosis when compared to others. In the MM group, apelin level correlated negatively with LDH (r = -0.39, p= 0.038). In MM, plasma apelin level was significantly higher than in NHL and control groups. Apelin could be playing a role in MM pathogenesis; and apelin level could be used as a diagnostic and prognostic biomarker in MM.

  1. 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...

  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. In pursuit of an accurate spatial and temporal model of biomolecules at the atomistic level: a perspective on computer simulation

    PubMed Central

    Gray, Alan; Harlen, Oliver G.; Harris, Sarah A.; Khalid, Syma; Leung, Yuk Ming; Lonsdale, Richard; Mulholland, Adrian J.; Pearson, Arwen R.; Read, Daniel J.; Richardson, Robin A.

    2015-01-01

    Despite huge advances in the computational techniques available for simulating biomolecules at the quantum-mechanical, atomistic and coarse-grained levels, there is still a widespread perception amongst the experimental community that these calculations are highly specialist and are not generally applicable by researchers outside the theoretical community. In this article, the successes and limitations of biomolecular simulation and the further developments that are likely in the near future are discussed. A brief overview is also provided of the experimental biophysical methods that are commonly used to probe biomolecular structure and dynamics, and the accuracy of the information that can be obtained from each is compared with that from modelling. It is concluded that progress towards an accurate spatial and temporal model of biomacromolecules requires a combination of all of these biophysical techniques, both experimental and computational. PMID:25615870

  5. Temporal weighting of binaural information at low frequencies: Discrimination of dynamic interaural time and level differences

    PubMed Central

    Diedesch, Anna C.; Stecker, G. Christopher

    2015-01-01

    The importance of sound onsets in binaural hearing has been addressed in many studies, particularly at high frequencies, where the onset of the envelope may carry much of the useful binaural information. Some studies suggest that sound onsets might play a similar role in the processing of binaural cues [e.g., fine-structure interaural time differences (ITD)] at low frequencies. This study measured listeners' sensitivity to ITD and interaural level differences (ILD) present in early (i.e., onset) and late parts of 80-ms pure tones of 250-, 500-, and 1000-Hz frequency. Following previous studies, tones carried static interaural cues or dynamic cues that peaked at sound onset and diminished to zero at sound offset or vice versa. Although better thresholds were observed in static than dynamic conditions overall, ITD discrimination was especially impaired, regardless of frequency, when cues were not available at sound onset. Results for ILD followed a similar pattern at 1000 Hz; at lower frequencies, ILD thresholds did not differ significantly between dynamic-cue conditions. The results support the “onset” hypothesis of Houtgast and Plomp [(1968). J. Acoust. Soc. Am. 44, 807–812] for ITD discrimination, but not necessarily ILD discrimination, in low-frequency pure tones. PMID:26233013

  6. Temporal weighting of binaural information at low frequencies: Discrimination of dynamic interaural time and level differences.

    PubMed

    Diedesch, Anna C; Stecker, G Christopher

    2015-07-01

    The importance of sound onsets in binaural hearing has been addressed in many studies, particularly at high frequencies, where the onset of the envelope may carry much of the useful binaural information. Some studies suggest that sound onsets might play a similar role in the processing of binaural cues [e.g., fine-structure interaural time differences (ITD)] at low frequencies. This study measured listeners' sensitivity to ITD and interaural level differences (ILD) present in early (i.e., onset) and late parts of 80-ms pure tones of 250-, 500-, and 1000-Hz frequency. Following previous studies, tones carried static interaural cues or dynamic cues that peaked at sound onset and diminished to zero at sound offset or vice versa. Although better thresholds were observed in static than dynamic conditions overall, ITD discrimination was especially impaired, regardless of frequency, when cues were not available at sound onset. Results for ILD followed a similar pattern at 1000 Hz; at lower frequencies, ILD thresholds did not differ significantly between dynamic-cue conditions. The results support the "onset" hypothesis of Houtgast and Plomp [(1968). J. Acoust. Soc. Am. 44, 807-812] for ITD discrimination, but not necessarily ILD discrimination, in low-frequency pure tones.

  7. Global Coastal Exposure due to Sea-level Rise beyond Tipping Points with Multiple Warming Pathways

    NASA Astrophysics Data System (ADS)

    Tawatari, R.; Iseri, Y.; Kiguchi, M.; Kanae, S.

    2016-12-01

    Sea-level is observed and estimated to continue rising. In the future, the rise could be abrupt and irreversible in century to millennial timescale even if we conduct strong reduction of greenhouse gas emission. Greenland ice sheet and West Antarctic ice sheet are considered as attributable climate systems which would significantly enhance presently-projected sea-level rise by several meters if global mean temperature passes certain "Tipping points" which would exist around +1-5 degree Celsius above present temperature (1980-1999 average). Therefore, vulnerable coastal low-lying area, especially small islands, deltas or poor developing countries, would suffer from semi-permanent inundation and forced to counteract due to the enhanced sea-level rise. This study estimate range of sea-level rise until the year 2300 and 3000 considering excess of tipping points with using multiple levels of temperature scenarios which consist of excess tipping points and non-excess tipping points pathways. We extract state-of-the-art knowledge of tipping elements from paper reviewing to express reasonable relationship between temperature and abruptly-changing sea-level transition across the ages. This study also calculate coastal exposure globally as affected population, area and asset below the estimated sea-level for each countries with overlaying 30 arc-second gridded topography, population distribution and the sea-level. The result indicates which country would be critically affected if we follow overshooting pathways. Furthermore, this study visualize uncertain coastal exposure due to sea-level rise in the future from the multiple warming pathways. This estimation of possible future beyond tipping point would be useful information for decision-makers to establish new planning of defense, migration or mitigation for the future societies.

  8. 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.

  9. Physicians, Clinics, and Neighborhoods: Multiple Levels of Influence on Colorectal Cancer Screening

    PubMed Central

    Pruitt, Sandi L.; Leonard, Tammy; Zhang, Song; Schootman, Mario; Halm, Ethan A.; Gupta, Samir

    2014-01-01

    Background We 1) Described variability in colorectal cancer (CRC) test use across multiple levels, including physician, clinic, and neighborhood; and 2) Compared the performance of novel cross-classified vs. traditional hierarchical models. Methods We examined multilevel variation in CRC test use among patients not up-to-date with screening in a large, urban safety net health system (2011–2012). Outcomes included: 1) fecal occult blood test (FOBT) or 2) colonoscopy and were ascertained using claims data during a 1-year follow-up. We compared Bayesian 1) Cross-classified 4-level logistic models nesting patients within separate, non-overlapping “levels” (physicians, clinics, and census tracts) vs. 2) Three hierarchical 2-level models using deviance information criterion. Models adjusted for covariates (patient sociodemographic factors, driving time to clinic, and census tract poverty rate). Results Of 3,195 patients, 157 (4.9%) completed FOBT and 292 (9.1%) completed colonoscopy during the study year. Patients attended 19 clinics, saw 177 physicians, and resided in 332 census tracts. Significant variability was observed across all levels in both hierarchical and cross-classified models that was unexplained by measured covariates. For colonoscopy, variance was similar across all levels. For FOBT, physicians, followed by clinics, demonstrated the largest variability. Model fit using cross-classified models was superior or similar to 2-level hierarchical models. Conclusions Significant and substantial variability was observed across neighborhood, physician, and clinic levels in CRC test use, suggesting the importance of factors at each of these levels on CRC testing. Impact Future multilevel research and intervention should consider the simultaneous influences of multiple levels, including clinic, physician, and neighborhood. PMID:24732630

  10. 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.

  11. 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.

  12. Spatio-temporal factors associated with meningococcal meningitis annual incidence at the health centre level in Niger, 2004-2010.

    PubMed

    Paireau, Juliette; Maïnassara, Halima B; Jusot, Jean-François; Collard, Jean-Marc; Idi, Issa; Moulia-Pelat, Jean-Paul; Mueller, Judith E; Fontanet, Arnaud

    2014-05-01

    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. 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. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  18. Dietary Leucine - An Environmental Modifier of Insulin Resistance Acting on Multiple Levels of Metabolism

    PubMed Central

    Macotela, Yazmin; Emanuelli, Brice; Bång, Anneli M.; Espinoza, Daniel O.; Boucher, Jeremie; Beebe, Kirk; Gall, Walter; Kahn, C. Ronald

    2011-01-01

    Environmental factors, such as the macronutrient composition of the diet, can have a profound impact on risk of diabetes and metabolic syndrome. In the present study we demonstrate how a single, simple dietary factor—leucine—can modify insulin resistance by acting on multiple tissues and at multiple levels of metabolism. Mice were placed on a normal or high fat diet (HFD). Dietary leucine was doubled by addition to the drinking water. mRNA, protein and complete metabolomic profiles were assessed in the major insulin sensitive tissues and serum, and correlated with changes in glucose homeostasis and insulin signaling. After 8 weeks on HFD, mice developed obesity, fatty liver, inflammatory changes in adipose tissue and insulin resistance at the level of IRS-1 phosphorylation, as well as alterations in metabolomic profile of amino acid metabolites, TCA cycle intermediates, glucose and cholesterol metabolites, and fatty acids in liver, muscle, fat and serum. Doubling dietary leucine reversed many of the metabolite abnormalities and caused a marked improvement in glucose tolerance and insulin signaling without altering food intake or weight gain. Increased dietary leucine was also associated with a decrease in hepatic steatosis and a decrease in inflammation in adipose tissue. These changes occurred despite an increase in insulin-stimulated phosphorylation of p70S6 kinase indicating enhanced activation of mTOR, a phenomenon normally associated with insulin resistance. These data indicate that modest changes in a single environmental/nutrient factor can modify multiple metabolic and signaling pathways and modify HFD induced metabolic syndrome by acting at a systemic level on multiple tissues. These data also suggest that increasing dietary leucine may provide an adjunct in the management of obesity-related insulin resistance. PMID:21731668

  19. Commensal Rodents in the City of Buenos Aires: A Temporal, Spatial, and Environmental Analysis at the Whole City Level.

    PubMed

    Cavia, Regino; Muschetto, Emiliano; Cueto, Gerardo Rubén; Suárez, Olga Virginia

    2015-09-01

    Commensal rodents are some of the main vertebrate pests in urban areas; however, knowledge about factors that favor them at large scales is scarce. We studied spatial and temporal variations in rodent infestation levels at the whole city scale using the complaints of rodent sightings and questionnaire surveys to city neighbors. Demographic, socio-economic, and environmental characteristics handled with a geographic information system were evaluated as possible indicators of rodent infestation. The number of rodent sightings was lower in months with low mean temperature with two months time lag and higher in areas with high number of meat and metal industries. Rodent infestation estimated by the questionnaire survey showed spatial autocorrelation defining large areas with similar infestation levels. It decreased when the apartment density increased, while increased when the proportion of area occupied by shantytowns, the density of meat industries, and the proportion of area occupied by moderate urban development increased. Rodent control programs at the whole city level would have better results if public health pest agencies and/or governments will focus the efforts on areas with more precarious conditions as well as the industrial areas in the cold season when have lower rodent abundances.

  20. Planar UWB Filter with Multiple Notched Band and Stopband with Improved Rejection Level

    NASA Astrophysics Data System (ADS)

    Ghazali, Abu Nasar; Pal, Srikanta

    2015-05-01

    Analysis and realization of a microstrip-based planar ultra-wideband (UWB) filter with integrated multiple notch elimination property and simultaneously extended upper stopband is proposed. Initially, a UWB filter based on back-to-back microstrip-to-CPW technology is designed. Later, multiple spiral defected ground structures (DGS) are embedded to obtain multiple passband notches. Further, double equilateral U (DEU)-type DGS are used to improve upon the rejection level in upper stopband. The multiple passband notches are results of embedded spiral-shaped DGS (SDGS), while extended upper stopband is the outcome of suppressed higher-order spurious harmonics. The flexible dual-attenuation poles of DEU-shaped DGS suppress the stopband harmonics and widen the stopband. An approximate lumped equivalent circuit model of the proposed filter is modelled. The filter is compact and its layout measures 25.26 mm × 11.01 mm. The measured result is in good agreement with the full-wave electromagnetic (EM) simulation and circuit simulation.

  1. 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.

  2. Simultaneous application of multiple platforms (Glider, Scanfish, profiling mooring, CTD) to improve detection and quantification of temporal ocean dynamics

    NASA Astrophysics Data System (ADS)

    Meyer, D.; Prien, R. D.; Lips, U.; Naumann, M.; Liblik, T.; Schulz-Bull, D. E.

    2016-02-01

    Ocean dynamics are difficult to observe given the broad spectrum of temporal and spatial scales. Robotic technology can be used to address this issue, and help to investigate the variability of physical and biogeochemical processes. This work focuses on ocean robots and in particular on glider technology which seems to be one of the most promising oceanographic tools for future marine research. In this context, we present the results of an observational program conducted in the Baltic Sea combining a profiling mooring (GODESS - Gotland Deep Environmental Sampling Station) and glider technology (Slocum). The temporal variability is captured by the mooring, while the spatial variability is obtained from the glider sampling the surrounding area. Furthermore, classical CTD-measurements and an underwater vehicle (Scanfish) are used simultaneously by two different research vessels to validate and complement the observing network. The main aim of the study is to identify possible synergies between the different platforms and to get a better understanding of maximizing the information content of the data collected by this network. The value and the quality of the data of each individual platform is analyzed and their contribution to the performance of the network itself evaluated.

  3. 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.

  4. 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

  5. Space-time adaptive processing algorithm for airborne MIMO radar with nonside-looking array using temporally correlated multiple sparse Bayesian learning

    NASA Astrophysics Data System (ADS)

    Liu, Hanwei; Zhang, Yongshun; Guo, Yiduo; Wang, Qiang

    2017-01-01

    The near-range clutter of airborne nonside-looking array greatly depends on range. Conventional phased-array space-time adaptive processing (STAP) radar suffers severe performance degradation in the presence of a near-range clutter scenario. To efficiently suppress no-stationary clutter with only one snapshot, an STAP algorithm for airborne multiple-input multiple-output (MIMO) radar with nonside-looking array based on sparse representation is first presented, which is referred to as MIMOSR-STAP in this paper. By exploiting the waveform diversity of MIMO radar, each snapshot of a tested range-cell is transformed into the multisnapshots of phased array radar, which are used to estimate the high-resolution space-time spectrum with multiple measurement vectors technique. The proposed approach is effective in estimating the spectrum by utilizing temporally correlated multiple sparse Bayesian learning. In the sequel, the clutter covariance matrix and corresponding adaptive weight vector are efficiently obtained. MIMOSR-STAP enjoys high accuracy and robustness so that it achieves better performance of output signal-to-clutter-plus-noise-ratio and minimum detectable velocity than the single measurement vector sparse representation methods in the literature. Thus, MIMOSR-STAP performs well in a serious nonstationary clutter scenario and is suitable for an insufficient independent and identically distributed samples environment.

  6. 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

  7. 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

  8. 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

  9. Different FDG-PET metabolic patterns at single-subject level in the behavioral variant of fronto-temporal dementia.

    PubMed

    Cerami, Chiara; Dodich, Alessandra; Lettieri, Giada; Iannaccone, Sandro; Magnani, Giuseppe; Marcone, Alessandra; Gianolli, Luigi; Cappa, Stefano F; Perani, Daniela

    2016-10-01

    The diagnosis of probable behavioral variant of fronto-temporal dementia (bvFTD) according to current criteria requires the imaging evidence of frontal and/or anterior temporal atrophy or hypoperfusion/hypometabolism. Different variants of this pattern of brain involvement may, however, be found in individual cases, supporting the presence of heterogeneous phenotypes. We examined in a case-by-case approach the FDG-PET metabolic patterns of patients fulfilling clinical criteria for probable bvFTD, assessing the presence and frequency of specific FDG-PET features. Fifty two FDG-PET scans of probable bvFTD patients were retrospectively analyzed together with clinical and neuropsychological data. Neuroimaging experts rated the FDG-PET hypometabolism maps obtained at the single-subject level with optimized voxel-based Statistical Parametric Mapping (SPM). The functional metabolic heterogeneity was further tested by hierarchical cluster analysis and principal component analysis (PCA). Both the SPM maps and cluster analysis identified two major variants of cerebral hypometabolism, namely the "frontal" and the "temporo-limbic", which were correlated with different cognitive profiles. Executive and language deficits were the cognitive hallmark in the "frontal" subgroup, while poor encoding and recall on long-term memory tasks was typical of the "temporo-limbic" subgroup. SPM single-subject analysis indicates distinct patterns of brain dysfunction in bvFTD, coupled with specific clinical features, suggesting different profiles of neurodegenerative vulnerability. These findings have important implications for the early diagnosis of bvFTD and for the application of the recent international consensus criteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. 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

  11. Cerebrospinal fluid levels of alpha-tocopherol in patients with multiple sclerosis.

    PubMed

    Jiménez-Jiménez, F J; de Bustos, F; Molina, J A; de Andrés, C; Gasalla, T; Ortí-Pareja, M; Zurdo, M; Porta, J; Castellano-Millán, F; Arenas, J; Enríquez de Salamanca, R

    1998-06-12

    We compared cerebrospinal fluid (CSF) and serum levels, and the CSF/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 36 patients with multiple sclerosis (MS) and 32 matched controls. The mean CSF vitamin E levels and the CSF/serum vitamin E ratio did not differ significantly between the two study groups. The serum levels of vitamin E and the serum vitamin E/cholesterol ratio were significantly lower in MS patients when compared with controls (P < 0.05 and P < 0.01, respectively). These values were not correlated with age, age at onset and duration of the disease in the patients group. These results suggest that CSF vitamin E concentrations are not a marker of activity of MS activity.

  12. Serum levels of coenzyme Q10 in patients with multiple sclerosis.

    PubMed

    de Bustos, F; Jiménez-Jiménez, F J; Molina, J A; Gómez-Escalonilla, C; de Andrés, C; del Hoyo, P; Zurdo, M; Tallón-Barranco, A; Berbel, A; Porta-Etessam, J; Parrilla, G; Arenas, J

    2000-03-01

    To elucidate whether serum coenzyme Q10 levels are related with the risk for multiple sclerosis (MS) or are a marker for the activity of the disease, we compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio, in 31 patients with MS (during exacerbations) and 19 matched controls using a high performance liquid chromatography technique. The mean serum coenzyme Q10 levels and the coenzyme Q10/cholesterol ratio did not differ significantly between the 2 study groups. The values did not correlate with age, age at onset, and duration of the disease. These results suggest that serum coenzyme Q10 concentrations are unrelated with the risk for MS and are not a useful marker of activity of the disease.

  13. 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.

  14. Spatio-Temporal Variation of Longevity Clusters and the Influence of Social Development Level on Lifespan in a Chinese Longevous Area (1982–2010)

    PubMed Central

    Qin, Jian; Xia, Tianlong; Li, You; Liang, Xue; Wei, Peng; Long, Bingshuang; Lei, Mingzhi; Wei, Xiao; Tang, Xianyan; Zhang, Zhiyong

    2017-01-01

    The study aims to determine the spatial and temporal variation of a longevous region and explore the correlation between longevity and socioeconomic development. Population data at the township level were obtained from the last four population censuses (1982–2010). Five main lifespan indicators and the Human Development Index (HDI) were calculated. Getis-Ord G*, Gravity modeling, and Pearson’s r between lifespan indicators and HDI were applied. In this study, a stable longevous gathering area was discovered in Hechi during different periods. Under the influence of social and economic development, more longevous areas appeared. However, the effects of genetic and natural environmental factors on longevity were always dominant in this remote and mountainous city. Furthermore, longevity indicators lacked any significant correlation with life expectancy. No significant positive correlation was detected between lifespan indicators and HDI. Thus, we conclude that lifespan indicators can determine the spatial distribution and variation pattern of longevity from multiple dimensions. The geographical scope of longevity in Hechi City is gradually expanding, and significant spatial clustering was detected in southwestern, southern, and eastern parts of Hechi. This study also found that social economic development is likely to have a certain impact on new longevous areas, but their role on extreme longevity is not significant. PMID:28753971

  15. 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

  16. 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

  17. 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

  18. Increased serum level of IL-37 in patients with multiple sclerosis and neuromyelitis optica.

    PubMed

    Farrokhi, Mehrdad; Rezaei, Ali; Amani-Beni, Ali; Etemadifar, Masoud; Kouchaki, Ebrahim; Zahedi, Abolfazl

    2015-12-01

    Multiple sclerosis (MS) is a common autoimmune disease of central nervous system in which neurodegenerative and inflammatory mechanisms cause alternate neurological impairments. Many inflammatory and anti-inflammatory cytokines were suggested as contributor in MS pathogenesis, and the balance between these opposing cytokines can regulate MS severity. IL-37, an anti-inflammatory cytokine, is the most recently identified member of IL-1 family, which acts as a natural inhibitor of innate immunity. However, the role of IL-37 in MS has not investigated so far. Therefore, in this study, we aimed to measure serum level of IL-37 in patients with relapsing remitting multiple sclerosis (RRMS) and neuromyelitis optica (NMO). In a case-control study, plasma was collected from healthy controls (n = 49) and also patients with RRMS (n = 122) and NMO (n = 31). Serum level measurement of IL-37 was performed using enzyme-linked immunoassay (ELISA) method. The serum levels of IL-37 were 247.46 ± 74.02 and 312.00 ± 86.72 and 114.63 ± 20.58 in RRMS and NMO patients and healthy controls, respectively, showing statistically significant difference between them (P = 0.00). Furthermore, we found a positive correlation between the serum levels of IL-37 and EDSS of patients (r = +0.31 and P = 0.00). In summary, the serum level of IL-37 was found to be significantly increased in MS patients compared to healthy controls. Furthermore, the mean serum level of IL-37 was correlated with disease severity. This suggests that IL-37 may be part of a feed-back loop to control underlying inflammation in MS pathogenesis. However, further studies will be required to indicate exact role of IL-37 in the MS pathomechanisms.

  19. 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.

  20. 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. © 2016 Family Process Institute.

  1. 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

  2. Natalizumab Modifies Catecholamines Levels Present in Patients with Relapsing- Remitting Multiple Sclerosis.

    PubMed

    Escribano, Begona M; Aguilar-Luque, Macarena; Bahamonde, Carmen; Conde, Cristina; Lillo, Rafael; Sanchez-Lopez, Fernando; Giraldo, Ana I; Cruz, Antonio H; Luque, Evelio; Gascon, Felix; Aguera, Eduardo; Tunez, Isaac

    2016-01-01

    The main aim of this study was to verify the effect of natalizumab on the levels of circulating catecholamines and indolamine and their possible relation with MS. For this purpose, 12 healthy individuals (control group) and 12 relapsing-remitting multiple sclerosis patients (RR-MS) were selected. The patients were treated with 300 mg of natalizumab during 56 weeks (1 dose/4 weeks) (MS-56). This selection was based on the McDonalds revision criterion and scheduled to star treatment with natalizumab. Blood samples were taken before treatment (basal level) and after 56 weeks of using natalizumab. Melatonin was measured in serum and in plasma, catecholamines (dopamine, epinephrine, and norepinephrine), carbonylated proteins, 8-hydroxy-2'deoxyguanosine (8OH-dG) and the ratio reduced glutathione/oxidised glutathione (GSH/GSSG). The epinephrine and dopamine levels diminished in the basal group with respect to the control and did not recover normal levels with the treatment. The melatonin was decreased in RR-MS patients and went back to its normal levels with natalizumab. Norepinephrine was increased in RR-MS and decreased in MS-56 until it equalled the control group. Natalizumab normalizes altered melatonin and norepinephrine levels in MS.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Multiplicity

    DTIC Science & Technology

    1991-04-01

    practice as a "[descent] into that inner circle of the Inferno where the damned endlessly degate multiplicity for sentencing." United States v. Barnard...select the charges to be brought in a particular case"). 19 Brown v. Ohio, 432 U.S. 161, 165 (1977). 20 Whalen v. United States, 445 U.S. at 689. 21...parte Lange, 8-5 U.S. (19 Wall.) 163 (1874). Cf. Brown v. Ohio, 432 U.S. at 165 ("once the legislature has acted courts may not impose more than one

  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. Temporal Variation in Ankle Fractures and Orthopedic Resident Program Planning in an Urban Level 1 Trauma Center.

    PubMed

    Wynkoop, Aaron; Ndubaku, Osy; Walter, Norman; Atkinson, Theresa

    Previous studies have described the mechanism of ankle fractures, their seasonal variation, and fracture patterns but never in conjunction. In addition, the cohorts previously studied were either not from trauma centers or were often dominated by low-energy mechanisms. The present study aimed to describe the epidemiology of ankle fractures presenting to an urban level 1 trauma center. The records from an urban level 1 trauma center located in the Midwestern United States were retrospectively reviewed, and the injury mechanism and energy, time of injury, day of week, month, and patient characteristics (age, gender, comorbidities, smoking status) were collected. The fractures were classified using the AO (Arbeitsgemeinschaft für Osteosynthesefragen), Lauge-Hansen, and Danis-Weber systems. Of these systems, the Lauge-Hansen classification system resulted in the greatest number of "unclassifiable" cases. Most ankle fractures were due to high-energy mechanisms, with motor vehicle collisions the most common high-energy mechanism. The review found that most ankle fractures were malleolar fractures, regardless of the mechanism of injury. The ankle fracture patients had greater rates of obesity, diabetes, and smoking than present in the region where the hospital is located. The fractures were most likely to occur in the afternoon, with more fractures presenting on the weekend than earlier in the week and more fractures in the fall and winter than in the spring and summer. The temporal variation of these fractures should be considered for health services planning, in particular, in regard to resident physician staffing at urban level 1 trauma centers. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Circulating N-cadherin levels are a negative prognostic indicator in patients with multiple myeloma.

    PubMed

    Vandyke, Kate; Chow, Annie W S; Williams, Sharon A; To, Luen B; Zannettino, Andrew C W

    2013-05-01

    N-cadherin (cadherin 2, type 1, N-cadherin (neuronal); CDN2) is a homotypic adhesion molecule that is upregulated in breast, prostate and bladder cancer. Here we investigated the prognostic significance of upregulated N-cadherin expression in multiple myeloma (MM). Our results indicate that N-cadherin protein and gene expression is abnormally increased in trephine biopsies and CD38(++) /CD138(+) plasma cells from MM patients, when compared with those of normal donors. In addition, levels of circulating N-cadherin were elevated in a subset of patients with MM (n = 81; mean: 14·50 ng/ml, range: 0-146·78 ng/ml), relative to age-matched controls (n = 27; mean: 2·66 ng/ml, range: 0-5·96 ng/ml), although this did not reach statistical significance. Notably, patients with abnormally high levels of N-cadherin (>6 ng/ml) had decreased progression-free survival (P = 0·036; hazard ratio: 1·94) and overall survival (P = 0·002; hazard ratio: 3·15), when compared with patients with normal N-cadherin levels (≤6 ng/ml). Furthermore, multivariate analyses revealed that the combination of N-cadherin levels and International Staging System (ISS) was a more powerful prognostic indicator than using ISS alone. Collectively, our studies demonstrate that circulating N-cadherin levels are a viable prognostic marker for high-risk MM patients. © 2013 John Wiley & Sons Ltd.

  17. Feature-level fusion of multiple target detection results in hyperspectral image based on RX detector

    NASA Astrophysics Data System (ADS)

    Sun, Xu; Zhang, Bing; Yang, Lina; Gao, Lianru; Zhang, Wenjuan

    2012-05-01

    Target detection is an important research content in hyperspectral remote sensing technology, which is widely used in securities and defenses. Nowadays, many target detection algorithm have been proposed. One of the key evaluation indicators of these algorithms performance is false-alarm rate. The feature-level fusion of different target detection results is a simple and effective method to reduce false-alarm rate. But the different value ranges of different algorithms bring difficulties for data fusion. This paper proposed a feature-level fusion method based on RXD detector, which is to integrate multiple target detection results into a multi-bands image, and fuse detection results using principal theory of abnormal detection. Experiments revealed that, this method is not restricted by the quantity of target detection algorithms and not influenced by different value ranges of different algorithms, which can reduce false-alarm rate effectively.

  18. Comparison of Multiple Carrier Disposition PWM Techniques Applied for Multi-Level Shunt Active Filter

    NASA Astrophysics Data System (ADS)

    Kathalingam, Sebasthi Rani; Karantharaj, Porkumaran

    2012-07-01

    This work presents the simulation of a shunt active filter using seven-level cascaded inverter. The ultimate objective is to bring out the influence of multiple carrier level shifted PWM techniques on the performance of a shunt active filter. Classical disposition PWM techniques such as PD, POD and APOD have been used to generate the gating signals for the inverter active switches. A comparison is presented to substantiate the effect of these techniques in filtering. The comparison is made from the perspective of reduction in THD of source currents after filtering. For compensation current extraction synchronous detection method has been used. The harmonic reduction is achieved in source currents as well as source voltages.

  19. 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

  20. 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.

  1. A tractable probabilistic model for Affymetrix probe-level analysis across multiple chips.

    PubMed

    Liu, Xuejun; Milo, Marta; Lawrence, Neil D; Rattray, Magnus

    2005-09-15

    Affymetrix GeneChip arrays are currently the most widely used microarray technology. Many summarization methods have been developed to provide gene expression levels from Affymetrix probe-level data. Most of the currently popular methods do not provide a measure of uncertainty for the expression level of each gene. The use of probabilistic models can overcome this limitation. A full hierarchical Bayesian approach requires the use of computationally intensive MCMC methods that are impractical for large datasets. An alternative computationally efficient probabilistic model, mgMOS, uses Gamma distributions to model specific and non-specific binding with a latent variable to capture variations in probe affinity. Although promising, the main limitations of this model are that it does not use information from multiple chips and does not account for specific binding to the mismatch (MM) probes. We extend mgMOS to model the binding affinity of probe-pairs across multiple chips and to capture the effect of specific binding to MM probes. The new model, multi-mgMOS, provides improved accuracy, as demonstrated on some bench-mark datasets and a real time-course dataset, and is much more computationally efficient than a competing hierarchical Bayesian approach that requires MCMC sampling. We demonstrate how the probabilistic model can be used to estimate credibility intervals for expression levels and their log-ratios between conditions. Both mgMOS and the new model multi-mgMOS have been implemented in an R package, which is available at http://www.bioinf.man.ac.uk/resources/puma.

  2. 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.

  3. [Conduction disorders at multiple levels during the acute phase of a myocardial infarct: an electrophysiological study].

    PubMed

    García Burgos, A; Rangel Abundis, A; Castaño, R; Ramos, M A; Badui, E

    1993-01-01

    Forty patients with a diagnosis of acute myocardial infarction (anterior 24, and inferior 16) were studied. Of these patients, 37.5% manifested second and third degree atrioventricular (AV) block as a complication; another 30% showed complete right bundle branch and left anterior hemiblock. Right bundle branch and left posterior hemiblock were evidenced in 12.5% of the subjects. There was 20% with complete left bundle branch block. Electrophysiologic studies were performed in all patients to assess the site of block. A direct relation was found between the surface ECG and the His bundle electrogram studies in patients with an inferior myocardial infarction and AV block, both procedures located the conduction disturbances at the AV node (suprahisian block), in contrast to patients with anteroseptal myocardial infarction whose surface ECG only showed bundle branch block or fascicular block. The His bundle electrogram registered multiple levels of AV block, 70% with troncular and infrahisian block that gave way to sudden AV block. The mechanism responsible for this block was considered to be a functional longitudinal dissociation of conduction system due to an acute ischemic injury of the His bundle, more than a sudden and simultaneous failure of all the bundle branch of His. We conclude that electrophysiologic studies are a useful procedure for identification of a group of patients with multiple AV conduction disturbances that have a less favorable prognosis than those with only suprahisian level of block.

  4. 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

  5. Temporal changes in the levels of perfluorinated compounds in California women's serum over the past 50 years.

    PubMed

    Wang, Miaomiao; Park, June-Soo; Petreas, Myrto

    2011-09-01

    Serum samples collected from California women at different time periods: 1960s (n = 40), 1980s (n = 30), and 2009 (n = 35) were examined for the presence of 12 perfluorinated compounds (PFCs) using an online SPE-HPLC-MS/MS method. At each time period, perfluorooctane sulfonate (PFOS) was present at the highest concentration, followed by perfluorooctanoic acid (PFOA, except in the 1960s). We found the highest levels of PFOS (median = 42.1 ng/mL) and perfluorohexane sulfonate (PFHxS, median = 1.56 ng/mL) in the 1960s samples, possibly reflecting widespread use of precursor PFCs. PFOS showed a statistically significant drop from the 1960s to the 1980s (28.8 ng/mL ) and to 2009 (9.0 ng/mL ), the latter being in agreement with national data. For PFOA, there was an approximately 10-fold increase in median concentrations from the 1960s (0.27 ng/mL) to the 1980s (2.71 ng/mL), and a slight drop in the 2009 samples (2.08 ng/mL). For longer chain perfluorocarboxylic acids (PFCAs), there was a continuous build-up in serum from the 1960s to 2009. To our knowledge, this is the first study to investigate temporal changes of PFCs over the past 50 years.

  6. 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

  7. 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.

  8. In pursuit of an accurate spatial and temporal model of biomolecules at the atomistic level: a perspective on computer simulation

    SciTech Connect

    Gray, Alan; Harlen, Oliver G.; Harris, Sarah A.; Khalid, Syma; Leung, Yuk Ming; Lonsdale, Richard; Mulholland, Adrian J.; Pearson, Arwen R.; Read, Daniel J.; Richardson, Robin A.

    2015-01-01

    The current computational techniques available for biomolecular simulation are described, and the successes and limitations of each with reference to the experimental biophysical methods that they complement are presented. Despite huge advances in the computational techniques available for simulating biomolecules at the quantum-mechanical, atomistic and coarse-grained levels, there is still a widespread perception amongst the experimental community that these calculations are highly specialist and are not generally applicable by researchers outside the theoretical community. In this article, the successes and limitations of biomolecular simulation and the further developments that are likely in the near future are discussed. A brief overview is also provided of the experimental biophysical methods that are commonly used to probe biomolecular structure and dynamics, and the accuracy of the information that can be obtained from each is compared with that from modelling. It is concluded that progress towards an accurate spatial and temporal model of biomacromolecules requires a combination of all of these biophysical techniques, both experimental and computational.

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

    PubMed

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

    2014-11-01

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. 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.

  11. 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.

  12. 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.

  13. Multiple layers of temporal and spatial control regulate accumulation of the fruiting body-specific protein APP in Sordaria macrospora and Neurospora crassa.

    PubMed

    Nowrousian, Minou; Piotrowski, Markus; Kück, Ulrich

    2007-07-01

    During fungal fruiting body development, specialized cell types differentiate from vegetative mycelium. We have isolated a protein from the ascomycete Sordaria macrospora that is not present during vegetative growth but accumulates in perithecia. The protein was sequenced by mass spectrometry and the corresponding gene was termed app (abundant perithecial protein). app transcript occurs only after the onset of sexual development; however, the formation of ascospores is not a prerequisite for APP accumulation. The transcript of the Neurospora crassa ortholog is present prior to fertilization, but the protein accumulates only after fertilization. In crosses of N. crassa Deltaapp strains with the wild type, APP accumulates when the wild type serves as female parent, but not in the reciprocal cross; thus, the presence of a functional female app allele is necessary and sufficient for APP accumulation. These findings highlight multiple layers of temporal and spatial control of gene expression during fungal development.

  14. 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.

  15. 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.

  16. Temporal-spatial characteristics of wheelchair propulsion. Effects of level of spinal cord injury, terrain, and propulsion rate.

    PubMed

    Newsam, C J; Mulroy, S J; Gronley, J K; Bontrager, E L; Perry, J

    1996-01-01

    The purpose of this investigation was to compare the temporal-spatial characteristics of wheelchair propulsion (velocity, cycle distance, and cadence) of customary wheelchair users in conditions designed to simulate community settings. Seventy adult males with spinal cord injuries (SCI) were grouped by their level of SCI: low paraplegia (n = 17); high paraplegia (n = 19); C-7 tetraplegia (n = 17); C-6 tetraplegia (n = 17). Testing was performed in a wheelchair that had the right pushrim instrumented with force transducers. Participants propelled the test wheelchair at a self-selected, free, and fast pace over tile and carpeted floors. A wheelchair ergometer was designed to simulate loads encountered during propulsion over graded surfaces. Participants propelled the test wheelchair during ergometer simulation of 4% and 8% grades. Mean velocity, cycle distance, and cadence were calculated for each group in all test conditions. A two-way repeated measures analysis of variance and simple main effects testing for comparison across conditions and between groups were performed. For all test conditions, participants with low paraplegia were the fastest and had the longest cycle distance. With successively higher levels of SCI, velocities were slower and cycle distances shorter. During free propulsion on tile, velocities ranged from 95 m/min in low paraplegics to 55 m/min in C-6 tetraplegics. Fast propulsion velocity increased to 141 and 55 m/min, respectively. There was a significant main effect of surface for velocity such that the carpet condition was slower than the tile for all groups. Differences in velocity were most often the result of changes in cycle distance. High and low paraplegic groups were statistically similar for all test conditions. Participants with C-6 tetraplegia were significantly slower than all other groups for most test conditions. Because their fast propulsion velocities were slower than typical community demands, their ability to function

  17. [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.

  18. Possible Evidence of Multiple Sea Level Oscillations in the Seychelles During the Last Interglacial

    NASA Astrophysics Data System (ADS)

    Dutton, A. L.; Vyverberg, K.; Webster, J.; Dechnik, B.; Zwartz, D.; Lambeck, K.

    2013-12-01

    observations ostensibly support the notion that the last interglacial period was characterized by ice sheet instability, causing multiple sea level oscillations.

  19. Multiple remote sensing data sources to assess spatio-temporal patterns of fire incidence over Campos Amazônicos Savanna Vegetation Enclave (Brazilian Amazon).

    PubMed

    Alves, Daniel Borini; Pérez-Cabello, Fernando

    2017-12-01

    Fire activity plays an important role in the past, present and future of Earth system behavior. Monitoring and assessing spatial and temporal fire dynamics have a fundamental relevance in the understanding of ecological processes and the human impacts on different landscapes and multiple spatial scales. This work analyzes the spatio-temporal distribution of burned areas in one of the biggest savanna vegetation enclaves in the southern Brazilian Amazon, from 2000 to 2016, deriving information from multiple remote sensing data sources (Landsat and MODIS surface reflectance, TRMM pluviometry and Vegetation Continuous Field tree cover layers). A fire scars database with 30 m spatial resolution was generated using a Landsat time series. MODIS daily surface reflectance was used for accurate dating of the fire scars. TRMM pluviometry data were analyzed to dynamically establish time limits of the yearly dry season and burning periods. Burned area extent, frequency and recurrence were quantified comparing the results annually/seasonally. Additionally, Vegetation Continuous Field tree cover layers were used to analyze fire incidence over different types of tree cover domains. In the last seventeen years, 1.03millionha were burned within the study area, distributed across 1432 fire occurrences, highlighting 2005, 2010 and 2014 as the most affected years. Middle dry season fires represent 86.21% of the total burned areas and 32.05% of fire occurrences, affecting larger amount of higher density tree surfaces than other burning periods. The results provide new insights into the analysis of burned areas of the neotropical savannas, spatially and statistically reinforcing important aspects linked to the seasonality patterns of fire incidence in this landscape. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25104920

  1. 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.

  2. 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

  3. Circulating resistin levels and risk of multiple myeloma in three prospective cohorts.

    PubMed

    Santo, Loredana; Teras, Lauren R; Giles, Graham G; Weinstein, Stephanie J; Albanes, Demetrius; Wang, Ye; Pfeiffer, Ruth M; Lan, Qing; Rothman, Nathaniel; Birmann, Brenda M; Colditz, Graham A; Pollak, Michael N; Purdue, Mark P; Hofmann, Jonathan N

    2017-10-10

    Resistin is a polypeptide hormone secreted by adipose tissue. A prior hospital-based case-control study reported serum resistin levels to be inversely associated with risk of multiple myeloma (MM). To date, this association has not been investigated prospectively. We measured resistin concentrations for pre-diagnosis peripheral blood samples from 178 MM cases and 358 individually matched controls from three cohorts participating in the MM cohort consortium. In overall analyses, higher resistin levels were weakly associated with reduced MM risk. For men, we observed a statistically significant inverse association between resistin levels and MM (odds ratio, 0.44; 95% confidence interval (CI) 0.24-0.83 and 0.54; 95% CI 0.29-0.99, for the third and fourth quartiles, respectively, vs the lowest quartile; Ptrend=0.03). No association was observed for women. This study provides the first prospective evidence that low circulating resistin levels may be associated with an increased risk of MM, particularly for men.

  4. Rapid multiple-level coevolution in experimental populations of yeast killer and nonkiller strains.

    PubMed

    Pieczynska, Magdalena D; Wloch-Salamon, Dominika; Korona, Ryszard; de Visser, J Arjan G M

    2016-06-01

    Coevolution between different biological entities is considered an important evolutionary mechanism at all levels of biological organization. Here, we provide evidence for coevolution of a yeast killer strain (K) carrying cytoplasmic dsRNA viruses coding for anti-competitor toxins and an isogenic toxin-sensitive strain (S) during 500 generations of laboratory propagation. Signatures of coevolution developed at two levels. One of them was coadaptation of K and S. Killing ability of K first increased quickly and was followed by the rapid invasion of toxin-resistant mutants derived from S, after which killing ability declined. High killing ability was shown to be advantageous when sensitive cells were present but costly when they were absent. Toxin resistance evolved via a two-step process, presumably involving the fitness-enhancing loss of one chromosome followed by selection of a recessive resistant mutation on the haploid chromosome. The other level of coevolution occurred between cell and killer virus. By swapping the killer viruses between ancestral and evolved strains, we could demonstrate that changes observed in both host and virus were beneficial only when combined, suggesting that they involved reciprocal changes. Together, our results show that the yeast killer system shows a remarkable potential for rapid multiple-level coevolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  5. 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.

  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. 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.

  8. Reduced GABA levels correlate with cognitive impairment in patients with relapsing-remitting multiple sclerosis.

    PubMed

    Cao, Guanmei; Edden, Richard A E; Gao, Fei; Li, Hao; Gong, Tao; Chen, Weibo; Liu, Xiaohui; Wang, Guangbin; Zhao, Bin

    2017-10-06

    To investigate if brain gamma-aminobutyric acid (GABA) levels in patients with relapsing-remitting multiple sclerosis (RRMS) are abnormal compared with healthy controls, and their relationship to cognitive function in RRMS. Twenty-eight RRMS patients and twenty-six healthy controls underwent magnetic resonance spectroscopy (MRS) at 3-T to detect GABA signals from posterior cingulate cortex (PCC), medial prefrontal cortex (mPFC) and left hippocampus using the 'MEGAPoint Resolved Spectroscopy Sequence' (MEGA-PRESS) technique. All subjects also underwent a cognitive assessment. In RRMS patients, GABA+ were lower in the PCC (p = 0.036) and left hippocampus (p = 0.039) compared with controls, decreased GABA+ in the PCC and left hippocampus were associated with specific cognitive functions (r = -0.452, p = 0.016 and r = 0.451, p = 0.016 respectively); GABA+ in the mPFC were not significantly decreased or related to any cognitive scores (p > 0.05). This study demonstrates that abnormalities of the GABAergic system may be present in the pathogenesis of RRMS and suggests a potential link between regional GABA levels and cognitive impairment in patients with RRMS. • GABA levels may decrease in patients with RRMS. • Lower GABA levels correlated with worse cognitive performance in patients with RRMS. • Dysfunctional GABAergic neurotransmission may have a role in cognitive impairment in RRMS.

  9. 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

  10. 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.

  11. Robustly decoding multiple-line-structured light in temporal Fourier domain for fast and accurate three-dimensional reconstruction

    NASA Astrophysics Data System (ADS)

    Bian, Haidong; Liu, Kai

    2016-09-01

    Compared with grayscale patterns in structured light illumination, line stripes, as one binary pattern, are attractive for being more conveniently decoded. However, traditional line scanning typically involves a single line shifting across objects to avoid spatial ambiguities possibly introduced by complex surface geometry of objects. We propose a multiple-line strategy for fast and accurate reconstructing of the three-dimensional surfaces of targets. First, we build a mathematical model for multiline scanning, and second, we derive phase computation from the model along time axis and resolve the issue of ambiguity naturally. Errors of the proposed method are theoretically analyzed, and it shows that the proposed method is immune to nonlinearity and is robust to uncertainty. Experimental results demonstrate that the proposed method is of advantages both in accuracy and time cost.

  12. Multiple cervical levels: increased risk of dysphagia and dysphonia during anterior cervical discectomy.

    PubMed

    Danto, Joseph; DiCapua, John; Nardi, Dominic; Pekmezaris, Renee; Moise, Gregory; Lesser, Martin; Dimarzio, Paola

    2012-10-01

    Anterior cervical discectomy (ACD) is widely used for symptomatic cervical spine pathologies. The most common complications associated with this type of surgery are dysphagia and dysphonia; however, the risk factors associated with them have not been adequately elucidated. The purpose of this study is to assess the incidence of self-reported dysphagia and dysphonia and the associated risk factors after ACD. This study used a retrospective chart review of 149 patients who underwent ACD at a tertiary care facility operating in the New York metropolitan area over a period of 2½ years. Charts for ACD patients were reviewed by 6 trained researchers. Incidence rates for self-reported dysphagia and dysphonia were calculated using 95% exact confidence intervals (CI). Risk factors such as age, sex, surgical hours, number of disc levels, airway class, American Society of Anesthesiologists class, fiberoptic intubation, and intubation difficulty were assessed using logistic regression. The incidence of self-reported dysphagia was 12.1% (95% exact CI, 7.3%-18.4%); for dysphonia the self-reported incidence was 5.4% (95% exact CI, 2.3%-10.3%). Patients who underwent surgery at ≥4 cervical levels had a significant 4-fold increased risk (odds ratio=4; 95% CI, 1.1-13.8) of developing dysphonia and/or dysphagia compared with patients who underwent surgery at a single surgical level. This study confirms previous findings that the risk of developing dysphagia and/or dysphonia increases with the number of surgical levels, with multiple cervical levels representing a significantly higher postoperative risk, as compared with surgery at 1 level.

  13. 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.

  14. What role does the anterior temporal lobe play in sentence-level processing? Neural correlates of syntactic processing in semantic PPA

    PubMed Central

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

    2014-01-01

    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 anterior temporal lobes 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, in order 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 and functional MRI. 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, while anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the anterior temporal lobes, 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 anterior temporal lobe did show abnormal functionality in semantic PPA patients, however this took the unexpected form of a

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  20. A probabilistic framework for the spatio-temporal segmentation of multiple sclerosis lesions in MR images of the brain

    NASA Astrophysics Data System (ADS)

    Greenspan, Hayit; Mayer, Arnaldo; Shahar, Allon

    2003-05-01

    In this paper we describe the application of a novel statistical image-sequence (video) modeling scheme to sequences of multiple sclerosis (MS) images taken over time. A unique key feature of the proposed framework is the analysis of the image-sequence input as a single entity as opposed to a sequence of separate frames. The extracted space-time regions allow for the detection and identification of disease events and processes, such as the appearance and progression of lesions. According to the proposed methodology, coherent space-time regions in the feature space, and corresponding coherent segments in the video content are extracted by unsupervised clustering via Gaussian mixture modeling (GMM). The parameters of the GMM are determined via the maximum likelihood principle and the Expectation-Maximization (EM) algorithm. The clustering of the image sequence yields a collection of regions (blobs) in a four-dimensional feature space (including intensity, position (x,y), and time). Regions corresponding to MS lesions are automatically identified based on criteria regarding the mean intensity and the size variability over time. The proposed methodology was applied to a registered sequence of 24 T2-weighted MR images acquired from an MS patient over a period of approximately a year. Examples of preliminary qualitative results are shown.

  1. Disability weight for each level of the Expanded Disability Status Scale in multiple sclerosis.

    PubMed

    Cho, Joong-Yang; Hong, Keun-Sik; Kim, Ho Jin; Kim, Su-Hyun; Min, Ju-Hong; Kim, Nam-Hee; Ahn, Suk-Won; Park, Min Su; An, Jae-Young; Kim, Byung-Jo; Kim, Woojun

    2014-08-01

    The Expanded Disability Status Scale (EDSS) is the most widely employed ordinal disability scale in multiple sclerosis (MS). However, how far apart the individual EDSS levels are along the disability spectrum has not been formally quantified. The objective of this paper is to generate refined disability weights (DWs) for each of the ordinal EDSS levels. We performed the person trade-off (PTO) procedure to derive DWs of five representative EDSS categories (2, 4, 6, 7 and 9), and DWs of the remaining EDSS categories were assigned by linear interpolation. The modified Delphi process was used to achieve consensus among raters. DWs were 0.021 for EDSS 2, 0.199 for EDSS 4, 0.313 for EDSS 6, 0.617 for EDSS 7, and 0.926 for EDSS 9. Panel members achieved a high degree of consensus for each DW, as indicated by low coefficients of variation. Our DWs confirmed that EDSS is an ordinal scale with highly variable intervals. The availability of DW for each EDSS level allows direct comparison of each MS outcome state with other health states and provides a foundation for the estimation of the disability-adjusted life-years lost of individual patients. © The Author(s) 2013.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. Systemic inflammatory response and serum lipopolysaccharide levels predict multiple organ failure and death in alcoholic hepatitis.

    PubMed

    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

    2015-09-01

    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. 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. © 2015 by the American Association

  7. 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

  8. 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

  9. 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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

    PubMed

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2017-08-01

    Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

  16. Relationship Between Changes in the Temporal Dynamics of the Blood-Oxygen-Level-Dependent Signal and Hypoperfusion in Acute Ischemic Stroke.

    PubMed

    Khalil, Ahmed A; Ostwaldt, Ann-Christin; Nierhaus, Till; Ganeshan, Ramanan; Audebert, Heinrich J; Villringer, Kersten; Villringer, Arno; Fiebach, Jochen B

    2017-04-01

    Changes in the blood-oxygen-level-dependent (BOLD) signal provide a noninvasive measure of blood flow, but a detailed comparison with established perfusion parameters in acute stroke is lacking. We investigated the relationship between BOLD signal temporal delay and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) in stroke patients. In 30 patients with acute (<24 hours) ischemic stroke, we performed Pearson correlation and multiple linear regression between DSC-MRI parameters (time to maximum [Tmax], mean transit time, cerebral blood flow, and cerebral blood volume) and BOLD-based parameters (BOLD delay and coefficient of BOLD variation). Prediction of severe hypoperfusion (Tmax >6 seconds) was assessed using receiver-operator characteristic (ROC) analysis. Correlation was highest between Tmax and BOLD delay (venous sinus reference; time shift range 7; median r=0.60; interquartile range=0.49-0.71). Coefficient of BOLD variation correlated with cerebral blood volume (median r= 0.37; interquartile range=0.24-0.51). Mean R(2) for predicting BOLD delay by DSC-MRI was 0.54 (SD=0.2) and for predicting coefficient of BOLD variation was 0.37 (SD=0.17). BOLD delay (whole-brain reference, time shift range 3) had an area under the curve of 0.76 for predicting severe hypoperfusion (sensitivity=69.2%; specificity=80%), whereas BOLD delay (venous sinus reference, time shift range 3) had an area under the curve of 0.76 (sensitivity=67.3%; specificity=83.5%). BOLD delay is related to macrovascular delay and microvascular hypoperfusion, can identify severely hypoperfused tissue in acute stroke, and is a promising alternative to gadolinium contrast agent-based perfusion assessment in acute stroke. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00715533 and NCT02077582. © 2017 American Heart Association, Inc.

  17. 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

  18. 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

  19. Meralgia paraesthetica: Ultrasound-guided injection at multiple levels with 12-month follow-up.

    PubMed

    Klauser, Andrea S; Abd Ellah, Mohamed M H; Halpern, Ethan J; Sporer, Isabella; Martinoli, Carlo; Tagliafico, Alberto; Sojer, Martin; Taljanovic, Mihra S; Jaschke, Werner R

    2016-03-01

    To evaluate the efficacy of ultrasound (US)-guided injections around the lateral femoral cutaneous nerve (LFCN) at different levels in meralgia paraesthetica (MP) patients. The study was approved by the university ethics committee and informed oral and written consent were obtained from all patients. Between June 2008 and August 2013, 20 patients with symptoms of MP, including nine men (mean age, 61.33 years) and 11 women (mean age 61.18 years), were treated with US-guided injection of steroids along the LFCN at three different levels in a mean of 2.25 sessions. A visual analogue scale (VAS) was used to measure symptoms before, immediately after and 12 months after treatment. Complete resolution of symptoms was documented in 15/20 patients (mean VAS decreased from 82 to 0), and partial resolution in the remaining five (mean VAS decreased from 92 to 42), which was confirmed at 12-month follow-up. By using the different levels of injection approach overall significantly better symptom relief was obtained (p < 0.05). The outcome of US-guided injection along the LFCN can be further improved by injections at different levels (p < 0.05), which was confirmed at 12-month long-term follow-up. Meralgia paraesthetica is an entrapment neuropathy of the lateral femoral cutaneous nerve. Ultrasound proved effective in diagnosis and in guiding injection therapy. Injection at the anterior superior iliac spine has been used previously. Multiple injections along the nerve course were used in this study. Long-term follow-up (12 months) confirmed the results.

  20. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The Drosophila nerfin-1 mRNA requires multiple microRNAs to regulate its spatial and temporal translation dynamics in the developing nervous system.

    PubMed

    Kuzin, Alexander; Kundu, Mukta; Brody, Thomas; Odenwald, Ward F

    2007-10-01

    The mRNA encoding the Drosophila Zn-finger transcription factor Nerfin-1, required for CNS axon pathfinding events, is subject to post-transcriptional silencing. Although nerfin-1 mRNA is expressed in many neural precursor cells including all early delaminating CNS neuroblasts, the encoded Nerfin-1 protein is detected only in the nuclei of neural precursors that divide just once to generate neurons and then only transiently in nascent neurons. Using a nerfin-1 promoter-controlled reporter transgene, replacement of the nerfin-1 3' UTR with the viral SV-40 3' UTR releases the neuroblast translational block and prolongs reporter protein expression in neurons. Comparative genomics analysis reveals that the nerfin-1 mRNA 3' UTR contains multiple highly conserved sequence blocks that either harbor and/or overlap 21 predicted binding sites for 18 different microRNAs. To determine the functional significance of these microRNA-binding sites and less conserved microRNA target sites, we have studied their ability to block or limit the expression of reporter protein in nerfin-1-expressing cells during embryonic development. Our results indicate that no single microRNA is sufficient to fully inhibit protein expression but rather multiple microRNAs that target different binding sites are required to block ectopic protein expression in neural precursor cells and temporally restrict expression in neurons. Taken together, these results suggest that multiple microRNAs play a cooperative role in the post-transcriptional regulation of nerfin-1 mRNA, and the high degree of microRNA-binding site evolutionary conservation indicates that all members of the Drosophila genus employ a similar strategy to regulate the onset and extinction dynamics of Nerfin-1 expression.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. Caregiver burden, quality of life and walking ability in different disability levels of multiple sclerosis.

    PubMed

    Ertekin, Özge; Özakbaş, Serkan; İdiman, Egemen

    2014-01-01

    The caregivers of Multiple Sclerosis (MS) individuals are usually burdened with a wide range of MS-related caregiving tasks which may result in damages of their daily life and quality of life (QOL). This study was designed to compare according to the disability level (1) the walking ability, quality of life (QOL), and disease impact of the MS patients (2) and the burden, QOL, self-efficacy and life satisfaction of their caregivers; (3) to determine the relationship between these outcome results, disease duration and caregivers' age. 772 MS patients were recruited, 47 MS patients and their 47 caregivers finished the study. Disability, walking ability, QOL, disease impact of the MS participants; the burden, QOL, self-efficacy, life satisfaction of the caregivers were evaluated. MS Patients with higher disability had significantly worse scores on the MSWS-12, MUSIQOL, MSIS-29, and PDSS (p < 0.01). The caregivers facing with higher disability had significantly worse scores on CBI and CAREQOL (p < 0.01). The impairments on disability level, walking and QOL of MS patients were related to OQL declines and increased burden of their caregivers. Therefore, it may be important to provide acceptable education and support strategies with individual intervention while defining the needs and goals of the MS patients and their caregivers to improve the rehabilitation success.

  7. DataSHIELD: an ethically robust solution to multiple-site individual-level data analysis.

    PubMed

    Budin-Ljøsne, Isabelle; Burton, Paul; Isaeva, Julia; Gaye, Amadou; Turner, Andrew; Murtagh, Madeleine J; Wallace, Susan; Ferretti, Vincent; Harris, Jennifer R

    2015-01-01

    DataSHIELD (Data Aggregation Through Anonymous Summary-statistics from Harmonised Individual levEL Databases) has been proposed to facilitate the co-analysis of individual-level data from multiple studies without physically sharing the data. In a previous paper, we investigated whether DataSHIELD could protect participant confidentiality in accordance with UK law. In this follow-up paper, we investigate whether DataSHIELD addresses a broader range of ethics-related data-sharing concerns. Ethics-related data-sharing concerns of Institutional Review Boards, ethics experts, international research consortia and research participants were identified through a literature search and systematically examined at a multidisciplinary workshop to determine whether DataSHIELD proposes mechanisms which can address these concerns. DataSHIELD addresses several ethics-related data-sharing concerns related to privacy, confidentiality, and the protection of the research participant's rights while sharing data and after the data have been shared. The data remain entirely under the direct management of the study that collected them. Data processing commands are strictly supervised, and the data are queried in a protected environment. Issues related to the return of individual research results when data are shared are eliminated; the responsibility for return remains at the study of origin. DataSHIELD can provide an innovative and robust solution for addressing commonly encountered ethics-related data-sharing concerns. © 2014 S. Karger AG, Basel.

  8. Coenzyme Q10 Levels Are Decreased in the Cerebellum of Multiple-System Atrophy Patients

    PubMed Central

    Schottlaender, Lucia V.; Bettencourt, Conceição; Kiely, Aoife P.; Chalasani, Annapurna; Neergheen, Viruna; Holton, Janice L.; Hargreaves, Iain; Houlden, Henry

    2016-01-01

    Background The objective of this study was to evaluate whether the levels of coenzyme Q10 (CoQ10) in brain tissue of multiple system atrophy (MSA) patients differ from those in elderly controls and in patients with other neurodegenerative diseases. Methods Flash frozen brain tissue of a series of 20 pathologically confirmed MSA patients [9 olivopontocerebellar atrophy (OPCA) type, 6 striatonigral degeneration (SND) type, and 5 mixed type] was used for this study. Elderly controls (n = 37) as well as idiopathic Parkinson's disease (n = 7), dementia with Lewy bodies (n = 20), corticobasal degeneration (n = 15) and cerebellar ataxia (n = 18) patients were used as comparison groups. CoQ10 was measured in cerebellar and frontal cortex tissue by high performance liquid chromatography. Results We detected a statistically significant decrease (by 3–5%) in the level of CoQ10 in the cerebellum of MSA cases (P = 0.001), specifically in OPCA (P = 0.001) and mixed cases (P = 0.005), when compared to controls as well as to other neurodegenerative diseases [dementia with Lewy bodies (P<0.001), idiopathic Parkinson's disease (P<0.001), corticobasal degeneration (P<0.001), and cerebellar ataxia (P = 0.001)]. Conclusion Our results suggest that a perturbation in the CoQ10 biosynthetic pathway is associated with the pathogenesis of MSA but the mechanism behind this finding remains to be elucidated. PMID:26894433

  9. 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

  10. Month of birth and level of insolation as risk factors for multiple sclerosis in Poland.

    PubMed

    Dobrakowski, Paweł; Bogocz, Michał; Cholewa, Kamil; Rajchel, Mateusz; Kapica-Topczewska, Katarzyna; Wawrzyniak, Sławomir; Bartosik-Psujek, Halina; Kułakowska, Alina; Koziarska, Dorota; Adamczyk-Sowa, Monika

    2017-01-01

    Many studies have shown that people born in the spring are at a higher risk of developing multiple sclerosis (MS). This may be associated with lower levels of sun exposure, and consequently, lower levels of vitamin D3 during pregnancy. However, these relationships have not been verified thus far in any countries in Central Europe. The aim of our study was to determine the frequency distribution of births for each calendar month in patients suffering from MS in Poland. We analyzed data for 2574 patients diagnosed with MS (1758 women, 816 men) living in Poland for an extended period. We added corrections resulting from the frequency distribution of births for the years in which the patients were born. We applied the Hewitt test for seasonality with Rogerson modification for 3-, 4-, or 6-month pulses or periods. Moreover, we examined the average number hours of sunshine in every month of the year. The rank-sums for successive 3- and 4-month segments indicated the period from September to December and from October to December as having a significantly lower incidence (p = 0.027 and p = 0.054, respectively). We did not find a correlation between with hours of sunshine in the first trimester of pregnancy, the child's birth month, and the child developing MS. We were able to confirm a seasonal variation in the risk of MS in Poland. However, these findings did not correlate with hours of sunshine during the first trimester of pregnancy.

  11. Self-reported levels of education and disability progression in multiple sclerosis.

    PubMed

    D'hooghe, M B; Haentjens, P; Van Remoortel, A; De Keyser, J; Nagels, G

    2016-12-01

    The purpose of our study is to investigate whether socioeconomic indicators such as education, financial concerns, employment, and living status are associated with disease progression in relapsing-onset and progressive-onset Multiple Sclerosis (MS). We performed a cross-sectional survey among individuals with MS, registered by the Flemish MS society and included socioeconomic indicators. A Cox proportional hazard regression was performed with the time from MS onset and from birth to reach an ambulatory disability milestone corresponding to Expanded Disability Status Scale (EDSS) 6 (requiring a cane) as outcome measure, adjusted for gender, age at MS onset, and immunomodulatory treatment. Among the participants with relapsing-onset MS, subjects reporting education for more than 12 years had a reduced risk of reaching EDSS 6 compared to subjects reporting education for less than 12 years [HR from onset 0.68 (95% CI 0.49-0.95); HR from birth 0.71 (95% CI 0.51-0.99)]. In progressive-onset MS, longer education was associated with an increased hazard to reach EDSS 6 [HR from onset 1.25 (95% CI 0.91-1.70); HR from birth 1.39 (95% CI 1.02-1.90)]. Our study shows an association of self-reported levels of education with disability progression in MS, with the highest level being protective in relapsing-onset MS. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. 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.

    2014-04-01

    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 effects of CO2 enrichment and its interaction with 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 effect of elevated CO2 levels was mediated by epiphyte proliferation (mostly the cyanobacterium Microcoleus spp.), but not through changes in plant biochemistry or population-level traits. In the low-nutrient meadow, epiphyte proliferation suppressed the CO2 benefits on Z. noltii leaf production and led to increased detritus and decreased organic matter in sediment. Faster and stronger responses to nutrients than to CO2 were observed. Nutrient addition enhanced the nutritional quality of Z. noltii (high N, low C : N and phenolics) and the loss of leaves and shoots, while promoted the proliferation of pennate diatoms and purple bacteria. These changes led to a reduced sediment organic matter, but had no significant effects on herbivory nor on community metabolism. Interestingly, the interaction with CO2 attenuated eutrophication effects. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing was observed, with no response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex, being mediated by epiphyte proliferation rather than by effects on plant biochemistry. The

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. Fast and robust brain tumor segmentation using level set method with multiple image information.

    PubMed

    Lok, Ka Hei; Shi, Lin; Zhu, Xianlun; Wang, Defeng

    2017-01-01

    Brain tumor segmentation is a challenging task for its variation in intensity. The phenomenon is caused by the inhomogeneous content of tumor tissue and the choice of imaging modality. In 2010 Zhang developed the Selective Binary Gaussian Filtering Regularizing Level Set (SBGFRLS) model that combined the merits of edge-based and region-based segmentation. To improve the SBGFRLS method by modifying the singed pressure force (SPF) term with multiple image information and demonstrate effectiveness of proposed method on clinical images. In original SBGFRLS model, the contour evolution direction mainly depends on the SPF. By introducing a directional term in SPF, the metric could control the evolution direction. The SPF is altered by statistic values enclosed by the contour. This concept can be extended to jointly incorporate multiple image information. The new SPF term is expected to bring a solution for blur edge problem in brain tumor segmentation. The proposed method is validated with clinical images including pre- and post-contrast magnetic resonance images. The accuracy and robustness is compared with sensitivity, specificity, DICE similarity coefficient and Jaccard similarity index. Experimental results show improvement, in particular the increase of sensitivity at the same specificity, in segmenting all types of tumors except for the diffused tumor. The novel brain tumor segmentation method is clinical-oriented with fast, robust and accurate implementation and a minimal user interaction. The method effectively segmented homogeneously enhanced, non-enhanced, heterogeneously-enhanced, and ring-enhanced tumor under MR imaging. Though the method is limited by identifying edema and diffuse tumor, several possible solutions are suggested to turn the curve evolution into a fully functional clinical diagnosis tool.

  20. 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

  1. 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.

  2. Astragaloside IV attenuates experimental autoimmune encephalomyelitis of mice by counteracting oxidative stress at multiple levels.

    PubMed

    He, Yixin; Du, Min; Gao, Yan; Liu, Hongshuai; Wang, Hongwei; Wu, Xiaojun; Wang, Zhengtao

    2013-01-01

    Multiple sclerosis (MS) is a chronic autoimmune neuroinflammatory disease found mostly in young adults in the western world. Oxidative stress induced neuronal apoptosis plays an important role in the pathogenesis of MS. In current study, astragaloside IV (ASI), a natural saponin molecule isolated from Astragalus membranceus, given at 20 mg/kg daily attenuated the severity of experimental autoimmune encephalomyelitis (EAE) in mice significantly. Further studies disclosed that ASI treatment inhibited the increase of ROS and pro-inflammatory cytokine levels, down-regulation of SOD and GSH-Px activities, and elevation of iNOS, p53 and phosphorylated tau in central nervous system (CNS) as well as the leakage of BBB of EAE mice. Meanwhile, the decreased ratio of Bcl-2/Bax was reversed by ASI. Moreover, ASI regulated T-cell differentiation and infiltration into CNS. In neuroblast SH-SY5Y cells, ASI dose-dependently reduced cellular ROS level and phosphorylation of tau in response to hydrogen peroxide challenge by modulation of Bcl-2/Bax ratio. ASI also inhibited activation of microglia both in vivo and in vitro. iNOS up-regulation induced by IFNγ stimulation was abolished by ASI dose-dependently in BV-2 cells. In summary, ASI prevented the severity of EAE progression possibly by counterbalancing oxidative stress and its effects via reduction of cellular ROS level, enhancement of antioxidant defense system, increase of anti-apoptotic and anti-inflammatory pathways, as well as modulation of T-cell differentiation and infiltration into CNS. The study suggested ASI may be effective for clinical therapy/prevention of MS.

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

    PubMed

    Ngwa, Moise C; 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

    2016-11-01

    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. 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 ignored subzones differences in

  4. 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

  5. Using level data to estimate inflow hydrographs in ungauged sites of multiple reach systems

    NASA Astrophysics Data System (ADS)

    D'Oria, M.; Mignosa, P.; Tanda, M.

    2013-12-01

    Considering a natural river system, usually only few sites are monitored and equipped to measure discharge over time. However, the knowledge of the discharge hydrograph in a specific station is important for many purposes: calibration of rainfall-runoff model, building of new structures, flood frequency analysis, water resource management, etc.. In addition, continuous direct measurement of discharges in open channels can be impossible and in any way difficult to assess. Therefore, most frequently, only level gauges are used for monitoring the system. In this work we propose a methodology to estimate a flow hydrograph in completely ungauged upstream sites of multiple reach systems by means of level data available at monitored stations downstream. In particular, a Bayesian approach is proposed to solve this kind of inverse problem. Prior information, in terms of geostatistical models and tools, is used to represent the structure of the unknowns and to regularize the solution. The methodology requires a forward hydraulic model of the considered river system able to reproduce the routing process and to account for all the reach characteristics: roughness, bed slope, cross sections, confluences, structures, etc.. In this work, the forward model is the widely known HEC-RAS river analysis system. The methodology has been tested through synthetic examples of river confluences, that differ in the available water level data, in the boundary conditions and in the number of the estimated inflow time series. Known inflow time-series were routed downstream by means of HEC-RAS to obtain the downstream stage hydrographs used as observations to test the reverse procedure. In almost all cases, the observed water levels were corrupted with random errors to highlight the reliability of the methodology in preventing instabilities and overfitting. The procedure has been also tested on a real case study of a river confluence located at the city of Parma (Italy) to assess the tributary

  6. 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

  7. 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

  8. 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

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

    PubMed

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

    2015-10-21

    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. 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 proprioceptive information

  10. 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

  11. 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 e