Spatio-temporal alignment of multiple sensors

NASA Astrophysics Data System (ADS)

Zhang, Tinghua; Ni, Guoqiang; Fan, Guihua; Sun, Huayan; Yang, Biao

2018-01-01

Aiming to achieve the spatio-temporal alignment of multi sensor on the same platform for space target observation, a joint spatio-temporal alignment method is proposed. To calibrate the parameters and measure the attitude of cameras, an astronomical calibration method is proposed based on star chart simulation and collinear invariant features of quadrilateral diagonal between the observed star chart. In order to satisfy a temporal correspondence and spatial alignment similarity simultaneously, the method based on the astronomical calibration and attitude measurement in this paper formulates the video alignment to fold the spatial and temporal alignment into a joint alignment framework. The advantage of this method is reinforced by exploiting the similarities and prior knowledge of velocity vector field between adjacent frames, which is calculated by the SIFT Flow algorithm. The proposed method provides the highest spatio-temporal alignment accuracy compared to the state-of-the-art methods on sequences recorded from multi sensor at different times.

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. Copyright © 2016 Elsevier Inc. All rights reserved.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Task-level feedback can explain temporal recruitment of spatially fixed muscle synergies throughout postural perturbations

PubMed Central

Safavynia, Seyed A.

2012-01-01

Recent evidence suggests that complex spatiotemporal patterns of muscle activity can be explained with a low-dimensional set of muscle synergies or M-modes. While it is clear that both spatial and temporal aspects of muscle coordination may be low dimensional, constraints on spatial versus temporal features of muscle coordination likely involve different neural control mechanisms. We hypothesized that the low-dimensional spatial and temporal features of muscle coordination are independent of each other. We further hypothesized that in reactive feedback tasks, spatially fixed muscle coordination patterns—or muscle synergies—are hierarchically recruited via time-varying neural commands based on delayed task-level feedback. We explicitly compared the ability of spatially fixed (SF) versus temporally fixed (TF) muscle synergies to reconstruct the entire time course of muscle activity during postural responses to anterior-posterior support-surface translations. While both SF and TF muscle synergies could account for EMG variability in a postural task, SF muscle synergies produced more consistent and physiologically interpretable results than TF muscle synergies during postural responses to perturbations. Moreover, a majority of SF muscle synergies were consistent in structure when extracted from epochs throughout postural responses. Temporal patterns of SF muscle synergy recruitment were well-reconstructed by delayed feedback of center of mass (CoM) kinematics and reproduced EMG activity of multiple muscles. Consistent with the idea that independent and hierarchical low-dimensional neural control structures define spatial and temporal patterns of muscle activity, our results suggest that CoM kinematics are a task variable used to recruit SF muscle synergies for feedback control of balance. PMID:21957219

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.

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

PubMed

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

2017-12-01

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

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

MEG evidence that the central auditory system simultaneously encodes multiple temporal cues.

PubMed

Simpson, Michael I G; Barnes, Gareth R; Johnson, Sam R; Hillebrand, Arjan; Singh, Krish D; Green, Gary G R

2009-09-01

Speech contains complex amplitude modulations that have envelopes with multiple temporal cues. The processing of these complex envelopes is not well explained by the classical models of amplitude modulation processing. This may be because the evidence for the models typically comes from the use of simple sinusoidal amplitude modulations. In this study we used magnetoencephalography (MEG) to generate source space current estimates of the steady-state responses to simple one-component amplitude modulations and to a two-component amplitude modulation. A two-component modulation introduces the simplest form of modulation complexity into the waveform; the summation of the two-modulation rates introduces a beat-like modulation at the difference frequency between the two modulation rates. We compared the cortical representations of responses to the one-component and two-component modulations. In particular, we show that the temporal complexity in the two-component amplitude modulation stimuli was preserved at the cortical level. The method of stimulus normalization that we used also allows us to interpret these results as evidence that the important feature in sound modulations is the relative depth of one modulation rate with respect to another, rather than the absolute carrier-to-sideband modulation depth. More generally, this may be interpreted as evidence that modulation detection accurately preserves a representation of the modulation envelope. This is an important observation with respect to models of modulation processing, as it suggests that models may need a dynamic processing step to effectively model non-stationary stimuli. We suggest that the classic modulation filterbank model needs to be modified to take these findings into account.

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit.

PubMed

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva C

2012-03-19

Perfluoroalkyl acids (PFAAs) have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982-2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Cross-section and temporal time trend survey. Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998-2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998-2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.

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.…

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.

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit

PubMed Central

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva C.

2012-01-01

Objectives Perfluoroalkyl acids (PFAAs) have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982–2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Study design Cross-section and temporal time trend survey. Methods Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998–2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Results Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998–2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. Conclusions We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.1 PMID:22456049

Joint level-set and spatio-temporal motion detection for cell segmentation.

PubMed

Boukari, Fatima; Makrogiannis, Sokratis

2016-08-10

Cell segmentation is a critical step for quantification and monitoring of cell cycle progression, cell migration, and growth control to investigate cellular immune response, embryonic development, tumorigenesis, and drug effects on live cells in time-lapse microscopy images. In this study, we propose a joint spatio-temporal diffusion and region-based level-set optimization approach for moving cell segmentation. Moving regions are initially detected in each set of three consecutive sequence images by numerically solving a system of coupled spatio-temporal partial differential equations. In order to standardize intensities of each frame, we apply a histogram transformation approach to match the pixel intensities of each processed frame with an intensity distribution model learned from all frames of the sequence during the training stage. After the spatio-temporal diffusion stage is completed, we compute the edge map by nonparametric density estimation using Parzen kernels. This process is followed by watershed-based segmentation and moving cell detection. We use this result as an initial level-set function to evolve the cell boundaries, refine the delineation, and optimize the final segmentation result. We applied this method to several datasets of fluorescence microscopy images with varying levels of difficulty with respect to cell density, resolution, contrast, and signal-to-noise ratio. We compared the results with those produced by Chan and Vese segmentation, a temporally linked level-set technique, and nonlinear diffusion-based segmentation. We validated all segmentation techniques against reference masks provided by the international Cell Tracking Challenge consortium. The proposed approach delineated cells with an average Dice similarity coefficient of 89 % over a variety of simulated and real fluorescent image sequences. It yielded average improvements of 11 % in segmentation accuracy compared to both strictly spatial and temporally linked Chan

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

Changes of procalcitonin level in multiple trauma patients.

PubMed

Wojtaszek, Marek; Staśkiewicz, Grzegorz; Torres, Kamil; Jakubowski, Krzysztof; Rácz, Oliver; Cipora, Elżbieta

2014-01-01

Some aspects of the pathophysiology of complications in multiple-trauma patients still remain unclear. Mediators of inflammation have been postulated as playing a key role in being responsible for life threatening complications of multiple trauma patients. The objective of this study was to evaluate the prognostic value of procalcitonin (PCT) level in multiple trauma patients. A prospective study took place including patients with multiple trauma hospitalised in several hospital units. PCT level was measured in blood from 45 patients, aged 18-70 years using enzyme-linked immunoassay. The patients were divided into three groups: group I - individuals with multiple trauma with central nervous system injury; group II - those with multiple trauma without CNS injury; and group III - patients with isolated central nervous system injury. Initial PCT levels were below 0.5 ng mL(-1) regardless of the cause of trauma. In the 24th hour of observation, a statistically significant increase of PCT concentration vs. initial levels was recorded in all groups of patients. Then PCT levels decreased significantly at the 3rd measurement point in all groups, and they remained unchanged until the last measurement. The highest levels of PCT were observed in multiple trauma patients without CNS injury (group II). In this group of patients, a significantly longer duration of surgery in the post-trauma period affected PCT levels. PCT concentrations in patients who died were significantly greater than in survivors. A long lasting elevated concentration of procalcitonin in the post-traumatic period, or its repeated increase, is a good marker of developing complications observed earlier than clinical manifestations.

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

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.

Altered medial temporal activation related to local glutamate levels in subjects with prodromal signs of psychosis.

PubMed

Valli, Isabel; Stone, James; Mechelli, Andrea; Bhattacharyya, Sagnik; Raffin, Marie; Allen, Paul; Fusar-Poli, Paolo; Lythgoe, David; O'Gorman, Ruth; Seal, Marc; McGuire, Philip

2011-01-01

Both medial temporal cortical dysfunction and perturbed glutamatergic neurotransmission are regarded as fundamental pathophysiological features of psychosis. However, although animal models of psychosis suggest that these two abnormalities are interrelated, their relationship in humans has yet to be investigated. We used a combination of functional magnetic resonance imaging and magnetic resonance spectroscopy to investigate the relationship between medial temporal activation during an episodic memory task and local glutamate levels in 22 individuals with an at-risk mental state for psychosis and 14 healthy volunteers. We observed a significant between-group difference in the coupling of medial temporal activation with local glutamate levels. In control subjects, medial temporal activation during episodic encoding was positively associated with medial temporal glutamate. However, in the clinical population, medial temporal activation was reduced, and the relationship with glutamate was absent. In individuals at high risk of psychosis, medial temporal dysfunction seemed related to a loss of the normal relationship with local glutamate levels. This study provides the first evidence that links medial temporal dysfunction with the central glutamate system in humans and is consistent with evidence that drugs that modulate glutamatergic transmission might be useful in the treatment of psychosis. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

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...

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.

Navigability of multiplex temporal network

NASA Astrophysics Data System (ADS)

Wang, Yan; Song, Qiao-Zhen

2017-01-01

Real world complex systems have multiple levels of relationships and in many cases, they need to be modeled as multiplex networks where the same nodes can interact with each other in different layers, such as social networks. However, social relationships only appear at prescribed times so the temporal structures of edge activations can also affect the dynamical processes located above them. To consider both factors are simultaneously, we introduce multiplex temporal networks and propose three different walk strategies to investigate the concurrent dynamics of random walks and the temporal structure of multiplex networks. Thus, we derive analytical results for the multiplex centrality and coverage function in multiplex temporal networks. By comparing them with the numerical results, we show how the underlying topology of the layers and the walk strategy affect the efficiency when exploring the networks. In particular, the most interesting result is the emergence of a super-diffusion process, where the time scale of the multiplex is faster than that of both layers acting separately.

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…

Temporally consistent probabilistic detection of new multiple sclerosis lesions in brain MRI.

PubMed

Elliott, Colm; Arnold, Douglas L; Collins, D Louis; Arbel, Tal

2013-08-01

Detection of new Multiple Sclerosis (MS) lesions on magnetic resonance imaging (MRI) is important as a marker of disease activity and as a potential surrogate for relapses. We propose an approach where sequential scans are jointly segmented, to provide a temporally consistent tissue segmentation while remaining sensitive to newly appearing lesions. The method uses a two-stage classification process: 1) a Bayesian classifier provides a probabilistic brain tissue classification at each voxel of reference and follow-up scans, and 2) a random-forest based lesion-level classification provides a final identification of new lesions. Generative models are learned based on 364 scans from 95 subjects from a multi-center clinical trial. The method is evaluated on sequential brain MRI of 160 subjects from a separate multi-center clinical trial, and is compared to 1) semi-automatically generated ground truth segmentations and 2) fully manual identification of new lesions generated independently by nine expert raters on a subset of 60 subjects. For new lesions greater than 0.15 cc in size, the classifier has near perfect performance (99% sensitivity, 2% false detection rate), as compared to ground truth. The proposed method was also shown to exceed the performance of any one of the nine expert manual identifications.

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

Diversity promotes temporal stability across levels of ecosystem organization in experimental grasslands.

PubMed

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

2010-10-13

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.

Encoding of Natural Sounds at Multiple Spectral and Temporal Resolutions in the Human Auditory Cortex

PubMed Central

Santoro, Roberta; Moerel, Michelle; De Martino, Federico; Goebel, Rainer; Ugurbil, Kamil; Yacoub, Essa; Formisano, Elia

2014-01-01

Functional neuroimaging research provides detailed observations of the response patterns that natural sounds (e.g. human voices and speech, animal cries, environmental sounds) evoke in the human brain. The computational and representational mechanisms underlying these observations, however, remain largely unknown. Here we combine high spatial resolution (3 and 7 Tesla) functional magnetic resonance imaging (fMRI) with computational modeling to reveal how natural sounds are represented in the human brain. We compare competing models of sound representations and select the model that most accurately predicts fMRI response patterns to natural sounds. Our results show that the cortical encoding of natural sounds entails the formation of multiple representations of sound spectrograms with different degrees of spectral and temporal resolution. The cortex derives these multi-resolution representations through frequency-specific neural processing channels and through the combined analysis of the spectral and temporal modulations in the spectrogram. Furthermore, our findings suggest that a spectral-temporal resolution trade-off may govern the modulation tuning of neuronal populations throughout the auditory cortex. Specifically, our fMRI results suggest that neuronal populations in posterior/dorsal auditory regions preferably encode coarse spectral information with high temporal precision. Vice-versa, neuronal populations in anterior/ventral auditory regions preferably encode fine-grained spectral information with low temporal precision. We propose that such a multi-resolution analysis may be crucially relevant for flexible and behaviorally-relevant sound processing and may constitute one of the computational underpinnings of functional specialization in auditory cortex. PMID:24391486

Spatio-Temporal Data Model for Integrating Evolving Nation-Level Datasets

NASA Astrophysics Data System (ADS)

Sorokine, A.; Stewart, R. N.

2017-10-01

Ability to easily combine the data from diverse sources in a single analytical workflow is one of the greatest promises of the Big Data technologies. However, such integration is often challenging as datasets originate from different vendors, governments, and research communities that results in multiple incompatibilities including data representations, formats, and semantics. Semantics differences are hardest to handle: different communities often use different attribute definitions and associate the records with different sets of evolving geographic entities. Analysis of global socioeconomic variables across multiple datasets over prolonged time is often complicated by the difference in how boundaries and histories of countries or other geographic entities are represented. Here we propose an event-based data model for depicting and tracking histories of evolving geographic units (countries, provinces, etc.) and their representations in disparate data. The model addresses the semantic challenge of preserving identity of geographic entities over time by defining criteria for the entity existence, a set of events that may affect its existence, and rules for mapping between different representations (datasets). Proposed model is used for maintaining an evolving compound database of global socioeconomic and environmental data harvested from multiple sources. Practical implementation of our model is demonstrated using PostgreSQL object-relational database with the use of temporal, geospatial, and NoSQL database extensions.

Temporal scaling and spatial statistical analyses of groundwater level fluctuations

NASA Astrophysics Data System (ADS)

Sun, H.; Yuan, L., Sr.; Zhang, Y.

2017-12-01

Natural dynamics such as groundwater level fluctuations can exhibit multifractionality and/or multifractality due likely to multi-scale aquifer heterogeneity and controlling factors, whose statistics requires efficient quantification methods. This study explores multifractionality and non-Gaussian properties in groundwater dynamics expressed by time series of daily level fluctuation at three wells located in the lower Mississippi valley, after removing the seasonal cycle in the temporal scaling and spatial statistical analysis. First, using the time-scale multifractional analysis, a systematic statistical method is developed to analyze groundwater level fluctuations quantified by the time-scale local Hurst exponent (TS-LHE). Results show that the TS-LHE does not remain constant, implying the fractal-scaling behavior changing with time and location. Hence, we can distinguish the potentially location-dependent scaling feature, which may characterize the hydrology dynamic system. Second, spatial statistical analysis shows that the increment of groundwater level fluctuations exhibits a heavy tailed, non-Gaussian distribution, which can be better quantified by a Lévy stable distribution. Monte Carlo simulations of the fluctuation process also show that the linear fractional stable motion model can well depict the transient dynamics (i.e., fractal non-Gaussian property) of groundwater level, while fractional Brownian motion is inadequate to describe natural processes with anomalous dynamics. Analysis of temporal scaling and spatial statistics therefore may provide useful information and quantification to understand further the nature of complex dynamics in hydrology.

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...

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.

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

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…

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.

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.

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.

Levels of processing with free and cued recall and unilateral temporal lobe epilepsy.

PubMed

Lespinet-Najib, Véronique; N'Kaoua, Bernard; Sauzéon, Hélène; Bresson, Christel; Rougier, Alain; Claverie, Bernard

2004-04-01

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 that LTLE patients were impaired for semantic processing (free and cued recall) and for phonetic processing (free and cued recall), while for RTLE patients deficits appeared in free recall with semantic processing. It is suggested that the left temporal lobe is involved in all aspects of verbal memory, and that the right temporal lobe is specialized in semantic processing. Moreover, our data seem to indicate that RTLE patients present a retrieval processing impairment (semantic condition), whereas the LTLE group is characterized by encoding difficulties in the phonetic and semantic condition.

Virtual temporal bone dissection system: OSU virtual temporal bone system: development and testing.

PubMed

Wiet, Gregory J; Stredney, Don; Kerwin, Thomas; Hittle, Bradley; Fernandez, Soledad A; Abdel-Rasoul, Mahmoud; Welling, D Bradley

2012-03-01

The objective of this project was to develop a virtual temporal bone dissection system that would provide an enhanced educational experience for the training of otologic surgeons. A randomized, controlled, multi-institutional, single-blinded validation study. The project encompassed four areas of emphasis: structural data acquisition, integration of the system, dissemination of the system, and validation. Structural acquisition was performed on multiple imaging platforms. Integration achieved a cost-effective system. Dissemination was achieved on different levels including casual interest, downloading of software, and full involvement in development and validation studies. A validation study was performed at eight different training institutions across the country using a two-arm randomized trial where study subjects were randomized to a 2-week practice session using either the virtual temporal bone or standard cadaveric temporal bones. Eighty subjects were enrolled and randomized to one of the two treatment arms; 65 completed the study. There was no difference between the two groups using a blinded rating tool to assess performance after training. A virtual temporal bone dissection system has been developed and compared to cadaveric temporal bones for practice using a multicenter trial. There was no statistical difference between practice on the current simulator compared to practice on human cadaveric temporal bones. Further refinements in structural acquisition and interface design have been identified, which can be implemented prior to full incorporation into training programs and used for objective skills assessment. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Featured Article: Serum [Met5]-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

Groundwater-level prediction using multiple linear regression and artificial neural network techniques: a comparative assessment

NASA Astrophysics Data System (ADS)

Sahoo, Sasmita; Jha, Madan K.

2013-12-01

The potential of multiple linear regression (MLR) and artificial neural network (ANN) techniques in predicting transient water levels over a groundwater basin were compared. MLR and ANN modeling was carried out at 17 sites in Japan, considering all significant inputs: rainfall, ambient temperature, river stage, 11 seasonal dummy variables, and influential lags of rainfall, ambient temperature, river stage and groundwater level. Seventeen site-specific ANN models were developed, using multi-layer feed-forward neural networks trained with Levenberg-Marquardt backpropagation algorithms. The performance of the models was evaluated using statistical and graphical indicators. Comparison of the goodness-of-fit statistics of the MLR models with those of the ANN models indicated that there is better agreement between the ANN-predicted groundwater levels and the observed groundwater levels at all the sites, compared to the MLR. This finding was supported by the graphical indicators and the residual analysis. Thus, it is concluded that the ANN technique is superior to the MLR technique in predicting spatio-temporal distribution of groundwater levels in a basin. However, considering the practical advantages of the MLR technique, it is recommended as an alternative and cost-effective groundwater modeling tool.

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

Level-dependent changes in detection of temporal gaps in noise markers by adults with normal and impaired hearing

PubMed Central

Horwitz, Amy R.; Ahlstrom, Jayne B.; Dubno, Judy R.

2011-01-01

Compression in the basilar-membrane input–output response flattens the temporal envelope of a fluctuating signal when more gain is applied to lower level than higher level temporal components. As a result, level-dependent changes in gap detection for signals with different depths of envelope fluctuation and for subjects with normal and impaired hearing may reveal effects of compression. To test these assumptions, gap detection with and without a broadband noise was measured with 1 000-Hz-wide (flatter) and 50-Hz-wide (fluctuating) noise markers as a function of marker level. As marker level increased, background level also increased, maintaining a fixed acoustic signal-to-noise ratio (SNR) to minimize sensation-level effects on gap detection. Significant level-dependent changes in gap detection were observed, consistent with effects of cochlear compression. For the flatter marker, gap detection that declines with increases in level up to mid levels and improves with further increases in level may be explained by an effective flattening of the temporal envelope at mid levels, where compression effects are expected to be strongest. A flatter effective temporal envelope corresponds to a reduced effective SNR. The effects of a reduction in compression (resulting in larger effective SNRs) may contribute to better-than-normal gap detection observed for some hearing-impaired listeners. PMID:22087921

Nonlinear computations shaping temporal processing of precortical vision.

PubMed

Butts, Daniel A; Cui, Yuwei; Casti, Alexander R R

2016-09-01

Computations performed by the visual pathway are constructed by neural circuits distributed over multiple stages of processing, and thus it is challenging to determine how different stages contribute on the basis of recordings from single areas. In the current article, we address this problem in the lateral geniculate nucleus (LGN), using experiments combined with nonlinear modeling capable of isolating various circuit contributions. We recorded cat LGN neurons presented with temporally modulated spots of various sizes, which drove temporally precise LGN responses. We utilized simultaneously recorded S-potentials, corresponding to the primary retinal ganglion cell (RGC) input to each LGN cell, to distinguish the computations underlying temporal precision in the retina from those in the LGN. Nonlinear models with excitatory and delayed suppressive terms were sufficient to explain temporal precision in the LGN, and we found that models of the S-potentials were nearly identical, although with a lower threshold. To determine whether additional influences shaped the response at the level of the LGN, we extended this model to use the S-potential input in combination with stimulus-driven terms to predict the LGN response. We found that the S-potential input "explained away" the major excitatory and delayed suppressive terms responsible for temporal patterning of LGN spike trains but revealed additional contributions, largely PULL suppression, to the LGN response. Using this novel combination of recordings and modeling, we were thus able to dissect multiple circuit contributions to LGN temporal responses across retina and LGN, and set the foundation for targeted study of each stage. Copyright © 2016 the American Physiological Society.

Principles of Temporal Processing Across the Cortical Hierarchy.

PubMed

Himberger, Kevin D; Chien, Hsiang-Yun; Honey, Christopher J

2018-05-02

The world is richly structured on multiple spatiotemporal scales. In order to represent spatial structure, many machine-learning models repeat a set of basic operations at each layer of a hierarchical architecture. These iterated spatial operations - including pooling, normalization and pattern completion - enable these systems to recognize and predict spatial structure, while robust to changes in the spatial scale, contrast and noisiness of the input signal. Because our brains also process temporal information that is rich and occurs across multiple time scales, might the brain employ an analogous set of operations for temporal information processing? Here we define a candidate set of temporal operations, and we review evidence that they are implemented in the mammalian cerebral cortex in a hierarchical manner. We conclude that multiple consecutive stages of cortical processing can be understood to perform temporal pooling, temporal normalization and temporal pattern completion. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of streamflow variability in Alpine catchments at multiple spatial and temporal scales

NASA Astrophysics Data System (ADS)

Pérez Ciria, T.; Chiogna, G.

2017-12-01

Alpine watersheds play a pivotal role in Europe for water provisioning and for hydropower production. In these catchments, temporal fluctuations of river discharge occur at multiple temporal scales due to natural as well as anthropogenic driving forces. In the last decades, modifications of the flow regime have been observed and their origin lies in the complex interplay between construction of dams for hydro power production, changes in water management policies and climatic changes. The alteration of the natural flow has negative impacts on the freshwater biodiversity and threatens the ecosystem integrity of the Alpine region. Therefore, understanding the temporal and spatial variability of river discharge has recently become a particular concern for environmental protection and represents a crucial contribution to achieve sustainable water resources management in the Alps. In this work, time series analysis is conducted for selected gauging stations in the Inn and the Adige catchments, which cover a large part of the central and eastern region of the Alps. We analyze the available time series using the continuous wavelet transform and change-point analyses for determining how and where changes have taken place. Although both catchments belong to different climatic zones of the Greater Alpine Region, streamflow properties share some similar characteristics. The comparison of the collected streamflow time series in the two catchments permits detecting gradients in the hydrological system dynamics that depend on station elevation, longitudinal location in the Alps and catchment area. This work evidences that human activities (e.g., water management practices and flood protection measures, changes in legislation and market regulation) have major impacts on streamflow and should be rigorously considered in hydrological models.

A multiple wavelet coherency method for temporal streamflow-precipitation-temperature relationships in 17 small catchments on the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Yang, Y.; Liu, B.

2017-12-01

Climate change and human activities are two critical factors causing the dramatical variations of streamflow in the Yellow River Basin of China during the last several decades. More and more attention has been paid to the temporal relationships of streamflow with precipitation and temperature recently. The objective of the current study was to explore the contributions of precipitation and temperature to the temporal variations of streamflow on the Loess Plateau using a multiple wavelet coherency method. Annual streamflow during 1961-2013 for 17 small catchments were collected from the Yellow River Conservancy Commission and annual precipitation and temperature for each catchment were derived from the meteorological data at the national weather stations across the Loess Plateau through the China Meteorological Data Sharing Service System. An abrupt decrease was observed in the annual streamflow around year 2000 for any of the 17 catchments investigated, which was believed to be related with the extensive Grain for Green Project. According to bivariate wavelet coherences, however, annual streamflow showed strong temporal variations with annual precipitation at 8 out of the 17 catchments, where the percentage area of significant coherency (PASC) exceeded 50%. Especially in Weihe and Yiluohe catchments, the corresponding PASC were close to 100%, suggesting that annual precipitation change accounted for almost all the temporal streamflow variations. Compared to annual precipitation, the temporal correlation of temperature with streamflow was relatively small, as implied in the lower mean wavelet coherence (MWC) and PASC. Moreover, including temperature in addition to precipitation in the multiple wavelet coherency analysis failed to increase either MWC or PASC in any of the 17 catchments except for Qingjianhe and Qiushuihe catchments. It was indicated that for most catchments on the Loess Plateau, annual temperature was not significantly different from the red noise in

Increasing Level of Aspiration by Matching Construal Level and Temporal Distance: The Motivating Effects of Contemplating "How" Now and "Why" Later

ERIC Educational Resources Information Center

Fessel, Florian

2009-01-01

Individuals trying to achieve goals often set a level of aspiration ahead of time, that is, they determine which specific outcomes in goal pursuit they desire to obtain. In the research contained in the current dissertation, I demonstrate that temporal distance and construal level have diametrically opposing effects on level of aspiration such…

Managing temporal relations

NASA Technical Reports Server (NTRS)

Britt, Daniel L.; Geoffroy, Amy L.; Gohring, John R.

1990-01-01

Various temporal constraints on the execution of activities are described, and their representation in the scheduling system MAESTRO is discussed. Initial examples are presented using a sample activity described. Those examples are expanded to include a second activity, and the types of temporal constraints that can obtain between two activities are explored. Soft constraints, or preferences, in activity placement are discussed. Multiple performances of activities are considered, with respect to both hard and soft constraints. The primary methods used in MAESTRO to handle temporal constraints are described as are certain aspects of contingency handling with respect to temporal constraints. A discussion of the overall approach, with indications of future directions for this research, concludes the study.

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.

Levels of word processing and incidental memory: dissociable mechanisms in the temporal lobe.

PubMed

Castillo, E M; Simos, P G; Davis, R N; Breier, J; Fitzgerald, M E; Papanicolaou, A C

2001-11-16

Word recall is facilitated when deep (e.g. semantic) processing is applied during encoding. This fact raises the question of the existence of specific brain mechanisms supporting different levels of information processing that can modulate incidental memory performance. In this study we obtained spatiotemporal brain activation profiles, using magnetic source imaging, from 10 adult volunteers as they performed a shallow (phonological) processing task and a deep (semantic) processing task. When phonological analysis of the word stimuli into their constituent phonemes was required, activation was largely restricted to the posterior portion of the left superior temporal gyrus (area 22). Conversely, when access to lexical/semantic representations was required, activation was found predominantly in the left middle temporal gyrus and medial temporal cortex. The differential engagement of each mechanism during word encoding was associated with dramatic changes in subsequent incidental memory performance.

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…

Complexities in Subsetting Level 2 Data

NASA Technical Reports Server (NTRS)

Huwe, Paul; Wei, Jennifer; Meyer, David; Silberstein, David S.; Alfred, Jerome; Savtchenko, Andrey K.; Johnson, James E.; Albayrak, Arif; Hearty, Thomas

2017-01-01

Satellite Level 2 data presents unique challenges for tools and services. From nonlinear spatial geometry to inhomogeneous file data structure to inconsistent temporal variables to complex data variable dimensionality to multiple file formats, there are many difficulties in creating general tools for Level 2 data support. At NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), we are implementing a general Level 2 Subsetting service for Level 2 data to a user-specified spatio-temporal region of interest (ROI). In this presentation, we will unravel some of the challenges faced in creating this service and the strategies we used to surmount them.

Multiple-sip temporal dominance of sensations associated with acceptance test: a study on special beers.

PubMed

Corrêa Simioni, Síntia Carla; Ribeiro, Michele Nayara; de Souza, Vanessa Rios; Nunes, Cleiton Antônio; Pinheiro, Ana Carla Marques

2018-03-01

In this study, we proposed the use of a multiple-sip temporal dominance of sensations (TDS) test alongside with an acceptance test over repeated consumption for the analysis of special beers, with the aim of contributing to a deeper understanding of consumer behavior regarding temporal descriptions and sensory acceptance. Consumers of special beers sequentially evaluated six sips of a particular type of beer by TDS analysis and an acceptance test was performed for each sip. Four different kinds of specialty beers were evaluated [Bohemian Pilsner (BP), Witbier (WB), Belgian Strong Ale Dubbel (BD), and Russian Imperial Stout (RS)]. In general, the descriptive profile of beers varied temporally, i.e., there was an increased dominance of bitterness and a decreased dominance of fruity, floral, toffee, and coffee attributes. Concurrently, a reduction in sensory acceptance with an increased number of sips, especially the last sip, was observed in two kinds of beers that possessed a strong flavor, BD and RS. BP and WB presented smooth attributes and low notable characteristics, which could have contributed to the maintenance of the acceptance grades as the number of sips increased. The combination of TDS and acceptance over repeated sips can be useful for obtaining detailed descriptions of products that are closer to real time consumption by consumers, and thus aids in ensuring good product performance once released. The information obtained can also help product development scientists to fine-tune product formulations and ensure acceptability.

Alpha-synuclein levels in patients with multiple system atrophy: a meta-analysis.

PubMed

Yang, Fei; Li, Wan-Jun; Huang, Xu-Sheng

2018-05-01

This study evaluates the relationship between multiple system atrophy and α-synuclein levels in the cerebrospinal fluid, plasma and neural tissue. Literature search for relevant research articles was undertaken in electronic databases and study selection was based on a priori eligibility criteria. Random-effects meta-analyses of standardized mean differences in α-synuclein levels between multiple system atrophy patients and normal controls were conducted to obtain the overall and subgroup effect sizes. Meta-regression analyses were performed to evaluate the effect of age, gender and disease severity on standardized mean differences. Data were obtained from 11 studies involving 378 multiple system atrophy patients and 637 healthy controls (age: multiple system atrophy patients 64.14 [95% confidence interval 62.05, 66.23] years; controls 64.16 [60.06, 68.25] years; disease duration: 44.41 [26.44, 62.38] months). Cerebrospinal fluid α-synuclein levels were significantly lower in multiple system atrophy patients than in controls but in plasma and neural tissue, α-synuclein levels were significantly higher in multiple system atrophy patients (standardized mean difference: -0.99 [-1.65, -0.32]; p = 0.001). Percentage of male multiple system atrophy patients was significantly positively associated with the standardized mean differences of cerebrospinal fluid α-synuclein levels (p = 0.029) whereas the percentage of healthy males was not associated with the standardized mean differences of cerebrospinal fluid α-synuclein levels (p = 0.920). In multiple system atrophy patients, α-synuclein levels were significantly lower in the cerebrospinal fluid and were positively associated with the male gender.

Association of baseline level of physical activity and its temporal changes with incident hypertension and diabetes mellitus.

PubMed

Lee, Jong-Young; Ryu, Seungho; Sung, Ki-Chul

2018-01-01

Background The association between baseline and temporal changes in physical activity and incident hypertension or diabetes mellitus in initially non-hypertensive or non-diabetic subjects is rarely known. Methods Among individuals who underwent consecutive comprehensive health screenings, their physical activity level was measured using a self-reported international physical activity questionnaire. First, subjects were classified into four categories: no regular physical activity with a sedentary lifestyle; minimal physical activity (<75 min/week); insufficient physical activity (≥75 min but <150 min/week); and sufficient physical activity (≥150 min/week). Second, subjects were sub-grouped, based on temporal changes in physical activity level between baseline and consecutive follow-up: increase, no change, and decrease. Results Finally, among 174,314 subjects (mean age 36.7 ± 6.9 years), 5544 (3.18%) and 21,276 (12.2%) developed incident diabetes mellitus and arterial hypertension, respectively. After a multivariate adjustment, sufficient baseline physical activity was associated with significantly lower risk for incident hypertension (hazard ratio 0.89; 95% confidence interval (CI) 0.81 to 0.97), but the difference was not significant, and showed a lower trend in diabetes mellitus incidence (hazard ratio 0.87; 95% CI 0.69 to 1.04) in reference to no regular physical activity group. Regardless of the baseline physical activity level, subjects with a temporal increase in physical activity showed significantly decreased risk for incident hypertension (hazard ratio 0.93; 95% CI 0.87 to 0.99) and diabetes mellitus (hazard ratio 0.83; 95% CI 0.74 to 0.92) compared with those with a temporal decrease in their physical activity level. Conclusion Both sufficient baseline physical activity level and its temporal increase were associated with a lower risk of incident hypertension and diabetes mellitus in a large, relatively healthy, cohort.

Using agent-based modeling to study multiple risk factors and multiple health outcomes at multiple levels.

PubMed

Yang, Yong

2017-11-01

Most health studies focus on one health outcome and examine the influence of one or multiple risk factors. However, in reality, various pathways, interactions, and associations exist not only between risk factors and health outcomes but also among the risk factors and among health outcomes. The advance of system science methods, Big Data, and accumulated knowledge allows us to examine how multiple risk factors influence multiple health outcomes at multiple levels (termed a 3M study). Using the study of neighborhood environment and health as an example, I elaborate on the significance of 3M studies. 3M studies may lead to a significantly deeper understanding of the dynamic interactions among risk factors and outcomes and could help us design better interventions that may be of particular relevance for upstream interventions. Agent-based modeling (ABM) is a promising method in the 3M study, although its potentials are far from being fully explored. Future challenges include the gap of epidemiologic knowledge and evidence, lack of empirical data sources, and the technical challenges of ABM. © 2017 New York Academy of Sciences.

Adjustable repetition-rate multiplication of optical pulses using fractional temporal Talbot effect with preceded binary intensity modulation

NASA Astrophysics Data System (ADS)

Xie, Qijie; Zheng, Bofang; Shu, Chester

2017-05-01

We demonstrate a simple approach for adjustable multiplication of optical pulses in a fiber using the temporal Talbot effect. Binary electrical patterns are used to control the multiplication factor in our approach. The input 10 GHz picosecond pulses are pedestal-free and are shaped directly from a CW laser. The pulses are then intensity modulated by different sets of binary patterns prior to entering a fiber of fixed dispersion. Tunable repetition-rate multiplication by different factors of 2, 4, and 8 have been achieved and up to 80 GHz pulse train has been experimentally generated. We also evaluate numerically the influence of the extinction ratio of the intensity modulator on the performance of the multiplied pulse train. In addition, the impact of the modulator bias on the uniformity of the output pulses has also been analyzed through simulation and experiment and a good agreement is reached. Last, we perform numerical simulation on the RF spectral characteristics of the output pulses. The insensitivity of the signal-to-subharmonic noise ratio (SSNR) to the laser linewidth shows that our multiplication scheme is highly tolerant to the incoherence of the input optical pulses.

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.

Community temporal variability increases with fluctuating resource availability

PubMed Central

Li, Wei; Stevens, M. Henry H.

2017-01-01

An increase in the quantity of available resources is known to affect temporal variability of aggregate community properties. However, it is unclear how might fluctuations in resource availability alter community-level temporal variability. Here we conduct a microcosm experiment with laboratory protist community subjected to manipulated resource pulses that vary in intensity, duration and time of supply, and examine the impact of fluctuating resource availability on temporal variability of the recipient community. The results showed that the temporal variation of total protist abundance increased with the magnitude of resource pulses, as protist community receiving infrequent resource pulses (i.e., high-magnitude nutrients per pulse) was relatively more unstable than community receiving multiple resource pulses (i.e., low-magnitude nutrients per pulse), although the same total amounts of nutrients were added to each community. Meanwhile, the timing effect of fluctuating resources did not significantly alter community temporal variability. Further analysis showed that fluctuating resource availability increased community temporal variability by increasing the degree of community-wide species synchrony and decreasing the stabilizing effects of dominant species. Hence, the importance of fluctuating resource availability in influencing community stability and the regulatory mechanisms merit more attention, especially when global ecosystems are experiencing high rates of anthropogenic nutrient inputs. PMID:28345592

Community temporal variability increases with fluctuating resource availability

NASA Astrophysics Data System (ADS)

Li, Wei; Stevens, M. Henry H.

2017-03-01

An increase in the quantity of available resources is known to affect temporal variability of aggregate community properties. However, it is unclear how might fluctuations in resource availability alter community-level temporal variability. Here we conduct a microcosm experiment with laboratory protist community subjected to manipulated resource pulses that vary in intensity, duration and time of supply, and examine the impact of fluctuating resource availability on temporal variability of the recipient community. The results showed that the temporal variation of total protist abundance increased with the magnitude of resource pulses, as protist community receiving infrequent resource pulses (i.e., high-magnitude nutrients per pulse) was relatively more unstable than community receiving multiple resource pulses (i.e., low-magnitude nutrients per pulse), although the same total amounts of nutrients were added to each community. Meanwhile, the timing effect of fluctuating resources did not significantly alter community temporal variability. Further analysis showed that fluctuating resource availability increased community temporal variability by increasing the degree of community-wide species synchrony and decreasing the stabilizing effects of dominant species. Hence, the importance of fluctuating resource availability in influencing community stability and the regulatory mechanisms merit more attention, especially when global ecosystems are experiencing high rates of anthropogenic nutrient inputs.

Spatial and temporal variation in evapotranspiration

USDA-ARS?s Scientific Manuscript database

Spatial and temporal variation in evapotranspiration occurs at multiple scales as the result of several different spatial and temporal patterns in precipitation, soil water holding capacity, cloudiness (available energy), types of crops, and residue and tillage management practices. We have often as...

Temporal rainfall disaggregation using a multiplicative cascade model for spatial application in urban hydrology

NASA Astrophysics Data System (ADS)

Müller, H.; Haberlandt, U.

2018-01-01

Rainfall time series of high temporal resolution and spatial density are crucial for urban hydrology. The multiplicative random cascade model can be used for temporal rainfall disaggregation of daily data to generate such time series. Here, the uniform splitting approach with a branching number of 3 in the first disaggregation step is applied. To achieve a final resolution of 5 min, subsequent steps after disaggregation are necessary. Three modifications at different disaggregation levels are tested in this investigation (uniform splitting at Δt = 15 min, linear interpolation at Δt = 7.5 min and Δt = 3.75 min). Results are compared both with observations and an often used approach, based on the assumption that a time steps with Δt = 5.625 min, as resulting if a branching number of 2 is applied throughout, can be replaced with Δt = 5 min (called the 1280 min approach). Spatial consistence is implemented in the disaggregated time series using a resampling algorithm. In total, 24 recording stations in Lower Saxony, Northern Germany with a 5 min resolution have been used for the validation of the disaggregation procedure. The urban-hydrological suitability is tested with an artificial combined sewer system of about 170 hectares. The results show that all three variations outperform the 1280 min approach regarding reproduction of wet spell duration, average intensity, fraction of dry intervals and lag-1 autocorrelation. Extreme values with durations of 5 min are also better represented. For durations of 1 h, all approaches show only slight deviations from the observed extremes. The applied resampling algorithm is capable to achieve sufficient spatial consistence. The effects on the urban hydrological simulations are significant. Without spatial consistence, flood volumes of manholes and combined sewer overflow are strongly underestimated. After resampling, results using disaggregated time series as input are in the range of those using observed time series. Best

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.

Temporal Dependency and the Structure of Early Looking.

PubMed

Messinger, Daniel S; Mattson, Whitney I; Todd, James Torrence; Gangi, Devon N; Myers, Nicholas D; Bahrick, Lorraine E

2017-01-01

Although looking time is used to assess infant perceptual and cognitive processing, little is known about the temporal structure of infant looking. To shed light on this temporal structure, 127 three-month-olds were assessed in an infant-controlled habituation procedure and presented with a pre-recorded display of a woman addressing the infant using infant-directed speech. Previous individual look durations positively predicted subsequent look durations over a six look window, suggesting a temporal dependency between successive infant looks. The previous look duration continued to predict the subsequent look duration after accounting for habituation-linked declines in look duration, and when looks were separated by an inter-trial interval in which no stimulus was displayed. Individual differences in temporal dependency, the strength of associations between consecutive look durations, are distinct from individual differences in mean infant look duration. Nevertheless, infants with stronger temporal dependency had briefer mean look durations, a potential index of stimulus processing. Temporal dependency was evident not only between individual infant looks but between the durations of successive habituation trials (total looking within a trial). Finally, temporal dependency was evident in associations between the last look at the habituation stimulus and the first look at a novel test stimulus. Thus temporal dependency was evident across multiple timescales (individual looks and trials comprised of multiple individual looks) and persisted across conditions including brief periods of no stimulus presentation and changes from a familiar to novel stimulus. Associations between consecutive look durations over multiple timescales and stimuli suggest a temporal structure of infant attention that has been largely ignored in previous work on infant looking.

Temporal Dependency and the Structure of Early Looking

PubMed Central

Messinger, Daniel S.; Mattson, Whitney I.; Todd, James Torrence; Gangi, Devon N.; Myers, Nicholas D.; Bahrick, Lorraine E.

2017-01-01

Although looking time is used to assess infant perceptual and cognitive processing, little is known about the temporal structure of infant looking. To shed light on this temporal structure, 127 three-month-olds were assessed in an infant-controlled habituation procedure and presented with a pre-recorded display of a woman addressing the infant using infant-directed speech. Previous individual look durations positively predicted subsequent look durations over a six look window, suggesting a temporal dependency between successive infant looks. The previous look duration continued to predict the subsequent look duration after accounting for habituation-linked declines in look duration, and when looks were separated by an inter-trial interval in which no stimulus was displayed. Individual differences in temporal dependency, the strength of associations between consecutive look durations, are distinct from individual differences in mean infant look duration. Nevertheless, infants with stronger temporal dependency had briefer mean look durations, a potential index of stimulus processing. Temporal dependency was evident not only between individual infant looks but between the durations of successive habituation trials (total looking within a trial). Finally, temporal dependency was evident in associations between the last look at the habituation stimulus and the first look at a novel test stimulus. Thus temporal dependency was evident across multiple timescales (individual looks and trials comprised of multiple individual looks) and persisted across conditions including brief periods of no stimulus presentation and changes from a familiar to novel stimulus. Associations between consecutive look durations over multiple timescales and stimuli suggest a temporal structure of infant attention that has been largely ignored in previous work on infant looking. PMID:28076362

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

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2014-01-01

Space launch 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.

Spontaneous neural activity in the right superior temporal gyrus and left middle temporal gyrus is associated with insight level in obsessive-compulsive disorder.

PubMed

Fan, Jie; Zhong, Mingtian; Gan, Jun; Liu, Wanting; Niu, Chaoyang; Liao, Haiyan; Zhang, Hongchun; Tan, Changlian; Yi, Jinyao; Zhu, Xiongzhao

2017-01-01

Insight into illness is an important issue for psychiatry disorder. Although the existence of a poor insight subtype of obsessive-compulsive disorder (OCD) was recognized in the DSM-IV, and the insight level in OCD was specified further in DSM-V, the neural underpinnings of insight in OCD have been rarely explored. The present study was designed to bridge this research gap by using resting-state functional magnetic resonance imaging (fMRI). Spontaneous neural activity were examined in 19 OCD patients with good insight (OCD-GI), 18 OCD patients with poor insight (OCD-PI), and 25 healthy controls (HC) by analyzing the amplitude of low-frequency fluctuation (ALFF) in the resting state. Pearson correlation analysis was performed between regional ALFFs and insight levels among OCD patients. OCD-GI and OCD-PI demonstrated overlapping and distinct brain alterations. Notably, compared with OCD-GI, tOCD-PI had reduced ALFF in left middle temporal gyrus (MTG) and right superior temporal gyrus (STG), as well as increased ALFF in right middle occipital gyrus. Further analysis revealed that ALFF values for the left MTG and right STG were correlated negatively with insight level in patients with OCD. Relatively small sample size and not all patients were un-medicated are our major limitations. Spontaneous brain activity in left MTG and right STG may be neural underpinnings of insight in OCD. Our results suggest the great role of human temporal brain regions in understanding insight, and further underscore the importance of considering insight presentation in understanding the clinical heterogeneity of OCD. Copyright © 2016 Elsevier B.V. All rights reserved.

Temporal characteristics of audiovisual information processing.

PubMed

Fuhrmann Alpert, Galit; Hein, Grit; Tsai, Nancy; Naumer, Marcus J; Knight, Robert T

2008-05-14

In complex natural environments, auditory and visual information often have to be processed simultaneously. Previous functional magnetic resonance imaging (fMRI) studies focused on the spatial localization of brain areas involved in audiovisual (AV) information processing, but the temporal characteristics of AV information flow in these regions remained unclear. In this study, we used fMRI and a novel information-theoretic approach to study the flow of AV sensory information. Subjects passively perceived sounds and images of objects presented either alone or simultaneously. Applying the measure of mutual information, we computed for each voxel the latency in which the blood oxygenation level-dependent signal had the highest information content about the preceding stimulus. The results indicate that, after AV stimulation, the earliest informative activity occurs in right Heschl's gyrus, left primary visual cortex, and the posterior portion of the superior temporal gyrus, which is known as a region involved in object-related AV integration. Informative activity in the anterior portion of superior temporal gyrus, middle temporal gyrus, right occipital cortex, and inferior frontal cortex was found at a later latency. Moreover, AV presentation resulted in shorter latencies in multiple cortical areas compared with isolated auditory or visual presentation. The results provide evidence for bottom-up processing from primary sensory areas into higher association areas during AV integration in humans and suggest that AV presentation shortens processing time in early sensory cortices.

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.

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

Differentiating levels of surgical experience on a virtual reality temporal bone simulator.

PubMed

Zhao, Yi C; Kennedy, Gregor; Hall, Richard; O'Leary, Stephen

2010-11-01

Virtual reality simulation is increasingly being incorporated into surgical training and may have a role in temporal bone surgical education. Here we test whether metrics generated by a virtual reality surgical simulation can differentiate between three levels of experience, namely novices, otolaryngology residents, and experienced qualified surgeons. Cohort study. Royal Victorian Eye and Ear Hospital. Twenty-seven participants were recruited. There were 12 experts, six residents, and nine novices. After orientation, participants were asked to perform a modified radical mastoidectomy on the simulator. Comparisons of time taken, injury to structures, and forces exerted were made between the groups to determine which specific metrics would discriminate experience levels. Experts completed the simulated task in significantly shorter time than the other two groups (experts 22 minutes, residents 36 minutes, and novices 46 minutes; P = 0.001). Novices exerted significantly higher average forces when dissecting close to vital structures compared with experts (0.24 Newton [N] vs 0.13 N, P = 0.002). Novices were also more likely to injure structures such as dura compared to experts (23 injuries vs 3 injuries, P = 0.001). Compared with residents, the experts modulated their force between initial cortex dissection and dissection close to vital structures. Using the combination of these metrics, we were able to correctly classify the participants' level of experience 90 percent of the time. This preliminary study shows that measurements of performance obtained from within a virtual reality simulator can differentiate between levels of users' experience. These results suggest that simulator training may have a role in temporal bone training beyond foundational training. Copyright © 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

Visualization of Spatio-Temporal Relations in Movement Event Using Multi-View

NASA Astrophysics Data System (ADS)

Zheng, K.; Gu, D.; Fang, F.; Wang, Y.; Liu, H.; Zhao, W.; Zhang, M.; Li, Q.

2017-09-01

Spatio-temporal relations among movement events extracted from temporally varying trajectory data can provide useful information about the evolution of individual or collective movers, as well as their interactions with their spatial and temporal contexts. However, the pure statistical tools commonly used by analysts pose many difficulties, due to the large number of attributes embedded in multi-scale and multi-semantic trajectory data. The need for models that operate at multiple scales to search for relations at different locations within time and space, as well as intuitively interpret what these relations mean, also presents challenges. Since analysts do not know where or when these relevant spatio-temporal relations might emerge, these models must compute statistical summaries of multiple attributes at different granularities. In this paper, we propose a multi-view approach to visualize the spatio-temporal relations among movement events. We describe a method for visualizing movement events and spatio-temporal relations that uses multiple displays. A visual interface is presented, and the user can interactively select or filter spatial and temporal extents to guide the knowledge discovery process. We also demonstrate how this approach can help analysts to derive and explain the spatio-temporal relations of movement events from taxi trajectory data.

Pain, Fatigue, and Cognitive Symptoms Are Temporally Associated Within but Not Across Days in Multiple Sclerosis.

PubMed

Kratz, Anna L; Murphy, Susan L; Braley, Tiffany J

2017-11-01

To examine the temporal associations, within day and day to day, between pain, fatigue, depressed mood, and cognitive function in multiple sclerosis (MS). Repeated-measures study involving 7 days of ecological momentary assessment (EMA) of symptoms 5 times a day; multilevel mixed models were used to analyze data. Community. Ambulatory adults (N=107) with MS. Not applicable. EMA of pain, fatigue, depressed mood, and cognitive function rated on a 0 to 10 scale. Fatigue and pain were linked within day such that higher pain was associated with higher subsequent fatigue (B=.09, P=.04); likewise, higher fatigue was associated with higher pain in the following time frame (B=.05, P=.04). Poorer perceived cognitive function preceded increased subsequent pain (B=.08, P=.007) and fatigue (B=.10, P=.01) within day. Depressed mood was not temporally linked with other symptoms. In terms of day-to-day effects, a day of higher fatigue related to decreased next day fatigue (B=-.16, P=.01), and a day of higher depressed mood related to increased depressed mood the next day (B=.17, P=.01). There were no cross-symptom associations from one day to the next. Findings provide new insights on how common symptoms in MS relate to each other and vary within and over days. Pain and fatigue show evidence of a dynamic bidirectional relation over the course of a day, and worsening of perceived cognitive function preceded worsening of both pain and fatigue. Most temporal associations between symptoms occur within the course of a day, with relatively little carryover from one day to the next. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Variability of Relative Sea Level Rise: Spatial and Temporal Correlations in Northwest Gulf of Mexico

NASA Astrophysics Data System (ADS)

Tissot, P.; Reisinger, A. S.; Besonen, M. R.

2017-12-01

While our understanding of global sea level rise and its budget has made great progress over the past decade, the spatial and temporal variability of relative sea level rise along the coasts still needs to be better understood and quantified. We developed a technique to reduce the confidence intervals associated with relative sea level rise (RSLR) estimates for 15 tide gauges located along the Texas coast for the period 1993-2016. Seasonally detrended monthly mean water levels are highly correlated after removal of station-specific RSLR trends, which allows for the quantification of a common, low frequency oceanic signal. RSLR confidence intervals are reduced from over 1.9 mm/yr, on average 2.3mm, to less than 1.1 mm/yr, on average 0.7 mm/yr after removing this common signal. The resulting RSLR rates range from 3.0 to 8.4 mm/yr. The range is wider than the longer-term rates of 5.3, 3.8 and 1.9 mm/yr measured from north to south by the three National Water Level Observation Network (NWLON) stations covering the study area (over different and longer time spans). The results emphasize the importance of the spatial variability of the vertical land motion component of RSLR. The temporal variability of the coherent oceanic signal is not significantly correlated to the ENSO signal for the study period and is only weakly correlated to the AMO and PDO climate indices. The coherence of the signal is further investigated by comparison with other locations along the Gulf of Mexico and along the Northeast Atlantic coast. The results are discussed while considering strong local processes along the Northwest Gulf of Mexico, such as wind forcing and intermittent eddies and the spatially broader influence of the Gulf Stream. The local significance of the RSLR spatial and temporal differences are discussed in terms of the differences in inundation frequency for nuisance type flooding including comparing the time span to reach a probability of at least one nuisance flood event per

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).

Retrograde amnesia in patients with hippocampal, medial temporal, temporal lobe, or frontal pathology.

PubMed

Bright, Peter; Buckman, Joseph; Fradera, Alex; Yoshimasu, Haruo; Colchester, Alan C F; Kopelman, Michael D

2006-01-01

There is considerable controversy concerning the theoretical basis of retrograde amnesia (R.A.). In the present paper, we compare medial temporal, medial plus lateral temporal, and frontal lesion patients on a new autobiographical memory task and measures of the more semantic aspects of memory (famous faces and news events). Only those patients with damage extending beyond the medial temporal cortex into the lateral temporal regions showed severe impairment on free recall remote memory tasks, and this held for both the autobiographical and the more semantic memory tests. However, on t-test analysis, the medial temporal group was impaired in retrieving recent autobiographical memories. Within the medial temporal group, those patients who had combined hippocampal and parahippocampal atrophy (H+) on quantified MRI performed somewhat worse on the semantic tasks than those with atrophy confined to the hippocampi (H-), but scores were very similar on autobiographical episodic recall. Correlational analyses with regional MRI volumes showed that lateral temporal volume was correlated significantly with performance on all three retrograde amnesia tests. The findings are discussed in terms of consolidation, reconsolidation, and multiple trace theory: We suggest that a widely distributed network of regions underlies the retrieval of past memories, and that the extent of lateral temporal damage appears to be critical to the emergence of a severe remote memory impairment.

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.

The Temporal and Spatial Variability of the Confined Aquifer Head and Storage Properties in the San Luis Valley, Colorado Inferred From Multiple InSAR Missions

NASA Astrophysics Data System (ADS)

Chen, Jingyi; Knight, Rosemary; Zebker, Howard A.

2017-11-01

Interferometric Synthetic Aperture Radar (InSAR) data from multiple satellite missions were combined to study the temporal and spatial variability of head and storage properties in a confined aquifer system on a decadal time scale. The area of study was a 4,500 km2 agricultural basin in the San Luis Valley (SLV), Colorado. We had available previous analyses of C-band ERS-1/2 data from June 1992 to November 2000, and L-band ALOS PALSAR data from October 2009 to March 2011. We used C-band Envisat data to fill in the time period from November 2006 to July 2010. In processing the Envisat data, we successfully employed a phase interpolation between persistent scatterer pixels to reduce the impact of vegetation decorrelation, which can significantly reduce the quality of C-band InSAR data over agricultural basins. In comparing the results from the L-band ALOS data and C-band Envisat data in a 10 month overlapping time period, we found that the shorter wavelength of C-band InSAR allowed us to preserve small deformation signals that were not detectable using L-band ALOS data. A significant result was the finding that the elastic storage properties of the SLV confined aquifer system remained stable over the 20 year time period and vary slowly in space, allowing us to combine InSAR data acquired from multiple missions to fill the temporal and spatial gaps in well data. The InSAR estimated head levels were validated with well measurements, which indicate little permanent water-storage loss over the study time period in the SLV.

Decoding visual object categories from temporal correlations of ECoG signals.

PubMed

Majima, Kei; Matsuo, Takeshi; Kawasaki, Keisuke; Kawai, Kensuke; Saito, Nobuhito; Hasegawa, Isao; Kamitani, Yukiyasu

2014-04-15

How visual object categories are represented in the brain is one of the key questions in neuroscience. Studies on low-level visual features have shown that relative timings or phases of neural activity between multiple brain locations encode information. However, whether such temporal patterns of neural activity are used in the representation of visual objects is unknown. Here, we examined whether and how visual object categories could be predicted (or decoded) from temporal patterns of electrocorticographic (ECoG) signals from the temporal cortex in five patients with epilepsy. We used temporal correlations between electrodes as input features, and compared the decoding performance with features defined by spectral power and phase from individual electrodes. While using power or phase alone, the decoding accuracy was significantly better than chance, correlations alone or those combined with power outperformed other features. Decoding performance with correlations was degraded by shuffling the order of trials of the same category in each electrode, indicating that the relative time series between electrodes in each trial is critical. Analysis using a sliding time window revealed that decoding performance with correlations began to rise earlier than that with power. This earlier increase in performance was replicated by a model using phase differences to encode categories. These results suggest that activity patterns arising from interactions between multiple neuronal units carry additional information on visual object categories. Copyright © 2013 Elsevier Inc. All rights reserved.

Modulation frequency discrimination with single and multiple channels in cochlear implant users

PubMed Central

Galvin, John J.; Oba, Sandy; Başkent, Deniz; Fu, Qian-Jie

2015-01-01

Temporal envelope cues convey important speech information for cochlear implant (CI) users. Many studies have explored CI users’ single-channel temporal envelope processing. However, in clinical CI speech processors, temporal envelope information is processed by multiple channels. Previous studies have shown that amplitude modulation frequency discrimination (AMFD) thresholds are better when temporal envelopes are delivered to multiple rather than single channels. In clinical fitting, current levels on single channels must often be reduced to accommodate multi-channel loudness summation. As such, it is unclear whether the multi-channel advantage in AMFD observed in previous studies was due to coherent envelope information distributed across the cochlea or to greater loudness associated with multi-channel stimulation. In this study, single- and multi-channel AMFD thresholds were measured in CI users. Multi-channel component electrodes were either widely or narrowly spaced to vary the degree of overlap between neural populations. The reference amplitude modulation (AM) frequency was 100 Hz, and coherent modulation was applied to all channels. In Experiment 1, single- and multi-channel AMFD thresholds were measured at similar loudness. In this case, current levels on component channels were higher for single- than for multi-channel AM stimuli, and the modulation depth was approximately 100% of the perceptual dynamic range (i.e., between threshold and maximum acceptable loudness). Results showed no significant difference in AMFD thresholds between similarly loud single- and multi-channel modulated stimuli. In Experiment 2, single- and multi-channel AMFD thresholds were compared at substantially different loudness. In this case, current levels on component channels were the same for single-and multi-channel stimuli (“summation-adjusted” current levels) and the same range of modulation (in dB) was applied to the component channels for both single- and multi

Spatial and temporal stability of temperature in the first-level basins of China during 1951-2013

NASA Astrophysics Data System (ADS)

Cheng, Yuting; Li, Peng; Xu, Guoce; Li, Zhanbin; Cheng, Shengdong; Wang, Bin; Zhao, Binhua

2018-05-01

In recent years, global warming has attracted great attention around the world. Temperature change is not only involved in global climate change but also closely linked to economic development, the ecological environment, and agricultural production. In this study, based on temperature data recorded by 756 meteorological stations in China during 1951-2013, the spatial and temporal stability characteristics of annual temperature in China and its first-level basins were investigated using the rank correlation coefficient method, the relative difference method, rescaled range (R/S) analysis, and wavelet transforms. The results showed that during 1951-2013, the spatial variation of annual temperature belonged to moderate variability in the national level. Among the first-level basins, the largest variation coefficient was 114% in the Songhuajiang basin and the smallest variation coefficient was 10% in the Huaihe basin. During 1951-2013, the spatial distribution pattern of annual temperature presented extremely strong spatial and temporal stability characteristics in the national level. The variation range of Spearman's rank correlation coefficient was 0.97-0.99, and the spatial distribution pattern of annual temperature showed an increasing trend. In the national level, the Liaohe basin, the rivers in the southwestern region, the Haihe basin, the Yellow River basin, the Yangtze River basin, the Huaihe basin, the rivers in the southeastern region, and the Pearl River basin all had representative meteorological stations for annual temperature. In the Songhuajiang basin and the rivers in the northwestern region, there was no representative meteorological station. R/S analysis, the Mann-Kendall test, and the Morlet wavelet analysis of annual temperature showed that the best representative meteorological station could reflect the variation trend and the main periodic changes of annual temperature in the region. Therefore, strong temporal stability characteristics exist for

Temporal stability of visually selective responses in intracranial field potentials recorded from human occipital and temporal lobes

PubMed Central

Bansal, Arjun K.; Singer, Jedediah M.; Anderson, William S.; Golby, Alexandra; Madsen, Joseph R.

2012-01-01

The cerebral cortex needs to maintain information for long time periods while at the same time being capable of learning and adapting to changes. The degree of stability of physiological signals in the human brain in response to external stimuli over temporal scales spanning hours to days remains unclear. Here, we quantitatively assessed the stability across sessions of visually selective intracranial field potentials (IFPs) elicited by brief flashes of visual stimuli presented to 27 subjects. The interval between sessions ranged from hours to multiple days. We considered electrodes that showed robust visual selectivity to different shapes; these electrodes were typically located in the inferior occipital gyrus, the inferior temporal cortex, and the fusiform gyrus. We found that IFP responses showed a strong degree of stability across sessions. This stability was evident in averaged responses as well as single-trial decoding analyses, at the image exemplar level as well as at the category level, across different parts of visual cortex, and for three different visual recognition tasks. These results establish a quantitative evaluation of the degree of stationarity of visually selective IFP responses within and across sessions and provide a baseline for studies of cortical plasticity and for the development of brain-machine interfaces. PMID:22956795

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 fastmore » neutron fluxes.« less

[Neural Mechanisms Underlying the Processing of Temporal Information in Episodic Memory and Its Disturbance].

PubMed

Iwata, Saeko; Tsukiura, Takashi

2017-11-01

Episodic memory is defined as memory for personally experienced events, and includes memory content and contextual information of time and space. Previous neuroimaging and neuropsychological studies have demonstrated three possible roles of the temporal context in episodic memory. First, temporal information contributes to the arrangement of temporal order for sequential events in episodic memory, and this process is involved in the lateral prefrontal cortex. The second possible role of temporal information in episodic memory is the segregation between memories of multiple events, which are segregated by cues of different time information. The role of segregation is associated with the orbitofrontal regions including the orbitofrontal cortex and basal forebrain region. Third, temporal information in episodic memory plays an important role in the integration of multiple components into a coherent episodic memory, in which episodic components in the different modalities are combined by temporal information as an index. The role of integration is mediated by the medial temporal lobe including the hippocampus and parahippocampal gyrus. Thus, temporal information in episodic memory could be represented in multiple stages, which are involved in a network of the lateral prefrontal, orbitofrontal, and medial temporal lobe regions.

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

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.

Hierarchical Spatio-temporal Visual Analysis of Cluster Evolution in Electrocorticography Data

DOE PAGES

Murugesan, Sugeerth; Bouchard, Kristofer; Chang, Edward; ...

2016-10-02

Here, we present ECoG ClusterFlow, a novel interactive visual analysis tool for the exploration of high-resolution Electrocorticography (ECoG) data. Our system detects and visualizes dynamic high-level structures, such as communities, using the time-varying spatial connectivity network derived from the high-resolution ECoG data. ECoG ClusterFlow provides a multi-scale visualization of the spatio-temporal patterns underlying the time-varying communities using two views: 1) an overview summarizing the evolution of clusters over time and 2) a hierarchical glyph-based technique that uses data aggregation and small multiples techniques to visualize the propagation of clusters in their spatial domain. ECoG ClusterFlow makes it possible 1) tomore » compare the spatio-temporal evolution patterns across various time intervals, 2) to compare the temporal information at varying levels of granularity, and 3) to investigate the evolution of spatial patterns without occluding the spatial context information. Lastly, we present case studies done in collaboration with neuroscientists on our team for both simulated and real epileptic seizure data aimed at evaluating the effectiveness of our approach.« less

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.

Contingent attentional capture across multiple feature dimensions in a temporal search task.

PubMed

Ito, Motohiro; Kawahara, Jun I

2016-01-01

The present study examined whether attention can be flexibly controlled to monitor two different feature dimensions (shape and color) in a temporal search task. Specifically, we investigated the occurrence of contingent attentional capture (i.e., interference from task-relevant distractors) and resulting set reconfiguration (i.e., enhancement of single task-relevant set). If observers can restrict searches to a specific value for each relevant feature dimension independently, the capture and reconfiguration effect should only occur when the single relevant distractor in each dimension appears. Participants identified a target letter surrounded by a non-green square or a non-square green frame. The results revealed contingent attentional capture, as target identification accuracy was lower when the distractor contained a target-defining feature than when it contained a nontarget feature. Resulting set reconfiguration was also obtained in that accuracy was superior when the current target's feature (e.g., shape) corresponded to the defining feature of the present distractor (shape) than when the current target's feature did not match the distractor's feature (color). This enhancement was not due to perceptual priming. The present study demonstrated that the principles of contingent attentional capture and resulting set reconfiguration held even when multiple target feature dimensions were monitored. Copyright © 2015 Elsevier B.V. All rights reserved.

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

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

PubMed

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

2016-01-01

Seizures are recognised in multiple sclerosis (MS), but their true incidence and the mechanism by which they are associated with MS is unclear. 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. 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). 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. 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. © The Author(s), 2015.

An operational ensemble prediction system for catchment rainfall over eastern Africa spanning multiple temporal and spatial scales

NASA Astrophysics Data System (ADS)

Riddle, E. E.; Hopson, T. M.; Gebremichael, M.; Boehnert, J.; Broman, D.; Sampson, K. M.; Rostkier-Edelstein, D.; Collins, D. C.; Harshadeep, N. R.; Burke, E.; Havens, K.

2017-12-01

While it is not yet certain how precipitation patterns will change over Africa in the future, it is clear that effectively managing the available water resources is going to be crucial in order to mitigate the effects of water shortages and floods that are likely to occur in a changing climate. One component of effective water management is the availability of state-of-the-art and easy to use rainfall forecasts across multiple spatial and temporal scales. We present a web-based system for displaying and disseminating ensemble forecast and observed precipitation data over central and eastern Africa. The system provides multi-model rainfall forecasts integrated to relevant hydrological catchments for timescales ranging from one day to three months. A zoom-in features is available to access high resolution forecasts for small-scale catchments. Time series plots and data downloads with forecasts, recent rainfall observations and climatological data are available by clicking on individual catchments. The forecasts are calibrated using a quantile regression technique and an optimal multi-model forecast is provided at each timescale. The forecast skill at the various spatial and temporal scales will discussed, as will current applications of this tool for managing water resources in Sudan and optimizing hydropower operations in Ethiopia and Tanzania.

Spatial-temporal and cancer risk assessment of selected hazardous air pollutants in Seattle.

PubMed

Wu, Chang-fu; Liu, L-J Sally; Cullen, Alison; Westberg, Hal; Williamson, John

2011-01-01

In the Seattle Air Toxics Monitoring Pilot Program, we measured 15 hazardous air pollutants (HAPs) at 6 sites for more than a year between 2000 and 2002. Spatial-temporal variations were evaluated with random-effects models and principal component analyses. The potential health risks were further estimated based on the monitored data, with the incorporation of the bootstrapping technique for the uncertainty analysis. It is found that the temporal variability was generally higher than the spatial variability for most air toxics. The highest temporal variability was observed for tetrachloroethylene (70% temporal vs. 34% spatial variability). Nevertheless, most air toxics still exhibited significant spatial variations, even after accounting for the temporal effects. These results suggest that it would require operating multiple air toxics monitoring sites over a significant period of time with proper monitoring frequency to better evaluate population exposure to HAPs. The median values of the estimated inhalation cancer risks ranged between 4.3 × 10⁻⁵ and 6.0 × 10⁻⁵, with the 5th and 95th percentile levels exceeding the 1 in a million level. VOCs as a whole contributed over 80% of the risk among the HAPs measured and arsenic contributed most substantially to the overall risk associated with metals. Copyright © 2010 Elsevier Ltd. All rights reserved.

Hemichorea after multiple bee stings.

PubMed

An, Jin Young; Kim, Ji Seon; Min, Jin Hong; Han, Kyu Hong; Kang, Jun Ho; Lee, Suk Woo; Kim, Hoon; Park, Jung Soo

2014-02-01

Bee sting is one of the most commonly encountered insect bites in the world. Despite the common occurrence of local and systemic allergic reactions, there are few reports of ischemic stroke after bee stings. To the best our knowledge, there have been no reports on involuntary hyperkinetic movement disorders after multiple bee stings. We report the case of a 50-year-old man who developed involuntary movements of the left leg 24 hours after multiple bee stings, and the cause was confirmed to be a right temporal infarction on a diffusion magnetic resonance imaging scan. Thus, we concluded that the involuntary movement disorder was caused by right temporal infarction that occurred after multiple bee stings.

Spatial-Temporal Dynamics of High-Resolution Animal Networks: What Can We Learn from Domestic Animals?

PubMed

Chen, Shi; Ilany, Amiyaal; White, Brad J; Sanderson, Michael W; Lanzas, Cristina

2015-01-01

Animal social network is the key to understand many ecological and epidemiological processes. We used real-time location system (RTLS) to accurately track cattle position, analyze their proximity networks, and tested the hypothesis of temporal stationarity and spatial homogeneity in these networks during different daily time periods and in different areas of the pen. The network structure was analyzed using global network characteristics (network density), subgroup clustering (modularity), triadic property (transitivity), and dyadic interactions (correlation coefficient from a quadratic assignment procedure) at hourly level. We demonstrated substantial spatial-temporal heterogeneity in these networks and potential link between indirect animal-environment contact and direct animal-animal contact. But such heterogeneity diminished if data were collected at lower spatial (aggregated at entire pen level) or temporal (aggregated at daily level) resolution. The network structure (described by the characteristics such as density, modularity, transitivity, etc.) also changed substantially at different time and locations. There were certain time (feeding) and location (hay) that the proximity network structures were more consistent based on the dyadic interaction analysis. These results reveal new insights for animal network structure and spatial-temporal dynamics, provide more accurate descriptions of animal social networks, and allow more accurate modeling of multiple (both direct and indirect) disease transmission pathways.

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).

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

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...

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.

Brain region and epilepsy-associated differences in inflammatory mediator levels in medically refractory mesial temporal lobe epilepsy.

PubMed

Strauss, Kenneth I; Elisevich, Kost V

2016-10-13

Epilepsy patients have distinct immune/inflammatory cell profiles and inflammatory mediator levels in the blood. Although the neural origin of inflammatory cells and mediators has been implied, few studies have measured these inflammatory components in the human brain itself. This study examines the brain levels of chemokines (8), cytokines (14), and vascular injury mediators (3) suspected of being altered in epilepsy. Soluble protein extracts of fresh frozen resected hippocampus, entorhinal cortex, and temporal cortex from 58 medically refractory mesial temporal lobe epilepsy subjects and 4 nonepileptic neurosurgical subjects were assayed for 25 inflammation-related mediators using ultrasensitive low-density arrays. Brain mediator levels were compared between regions and between epileptic and nonepileptic cases, showing a number of regional and possible epilepsy-associated differences. Eotaxin, interferon-γ, interleukin (IL)-2, IL-4, IL-12 p70, IL-17A, tumor necrosis factor-α, and intercellular adhesion molecule (ICAM)-1 levels were highest in the hippocampus, the presumptive site of epileptogenesis. Surprisingly, IL-1β and IL-1α were lowest in the hippocampus, compared to cortical regions. In the temporal cortex, IL-1β, IL-8, and MIP-1α levels were highest, compared to the entorhinal cortex and the hippocampus. The most pronounced epilepsy-associated differences were decreased levels of eotaxin, IL-1β, C-reactive protein, and vascular cell adhesion molecule (VCAM)-1 and increased IL-12 p70 levels. Caution must be used in interpreting these results, however, because nonepileptic subjects were emergent neurosurgical cases, not a control group. Correlation analyses of each mediator in each brain region yielded valuable insights into the regulation of these mediator levels in the brain. Over 70 % of the associations identified were between different mediators in a single brain region, providing support for local control of mediator levels. Correlations of

Multiplicative mixing of object identity and image attributes in single inferior temporal neurons.

PubMed

Ratan Murty, N Apurva; Arun, S P

2018-04-03

Object recognition is challenging because the same object can produce vastly different images, mixing signals related to its identity with signals due to its image attributes, such as size, position, rotation, etc. Previous studies have shown that both signals are present in high-level visual areas, but precisely how they are combined has remained unclear. One possibility is that neurons might encode identity and attribute signals multiplicatively so that each can be efficiently decoded without interference from the other. Here, we show that, in high-level visual cortex, responses of single neurons can be explained better as a product rather than a sum of tuning for object identity and tuning for image attributes. This subtle effect in single neurons produced substantially better population decoding of object identity and image attributes in the neural population as a whole. This property was absent both in low-level vision models and in deep neural networks. It was also unique to invariances: when tested with two-part objects, neural responses were explained better as a sum than as a product of part tuning. Taken together, our results indicate that signals requiring separate decoding, such as object identity and image attributes, are combined multiplicatively in IT neurons, whereas signals that require integration (such as parts in an object) are combined additively. Copyright © 2018 the Author(s). Published by PNAS.

An Arabidopsis introgression zone studied at high spatio-temporal resolution: interglacial and multiple genetic contact exemplified using whole nuclear and plastid genomes.

PubMed

Hohmann, Nora; Koch, Marcus A

2017-10-23

Gene flow between species, across ploidal levels, and even between evolutionary lineages is a common phenomenon in the genus Arabidopsis. However, apart from two genetically fully stabilized allotetraploid species that have been investigated in detail, the extent and temporal dynamics of hybridization are not well understood. An introgression zone, with tetraploid A. arenosa introgressing into A. lyrata subsp. petraea in the Eastern Austrian Forealps and subsequent expansion towards pannonical lowlands, was described previously based on morphological observations as well as molecular data using microsatellite and plastid DNA markers. Here we investigate the spatio-temporal context of this suture zone, making use of the potential of next-generation sequencing and whole-genome data. By utilizing a combination of nuclear and plastid genomic data, the extent, direction and temporal dynamics of gene flow are elucidated in detail and Late Pleistocene evolutionary processes are resolved. Analysis of nuclear genomic data significantly recognizes the clinal structure of the introgression zone, but also reveals that hybridization and introgression is more common and substantial than previously thought. Also tetraploid A. lyrata and A. arenosa subsp. borbasii from outside the previously defined suture zone show genomic signals of past introgression. A. lyrata is shown to serve usually as the maternal parent in these hybridizations, but one exception is identified from plastome-based phylogenetic reconstruction. Using plastid phylogenomics with secondary time calibration, the origin of A. lyrata and A. arenosa lineages is pre-dating the last three glaciation complexes (approx. 550,000 years ago). Hybridization and introgression followed during the last two glacial-interglacial periods (since approx. 300,000 years ago) with later secondary contact at the northern and southern border of the introgression zone during the Holocene. Footprints of adaptive introgression in the

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…

Complexities in Subsetting Satellite Level 2 Data

NASA Astrophysics Data System (ADS)

Huwe, P.; Wei, J.; Albayrak, A.; Silberstein, D. S.; Alfred, J.; Savtchenko, A. K.; Johnson, J. E.; Hearty, T.; Meyer, D. J.

2017-12-01

Satellite Level 2 data presents unique challenges for tools and services. From nonlinear spatial geometry to inhomogeneous file data structure to inconsistent temporal variables to complex data variable dimensionality to multiple file formats, there are many difficulties in creating general tools for Level 2 data support. At NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), we are implementing a general Level 2 Subsetting service for Level 2 data. In this presentation, we will unravel some of the challenges faced in creating this service and the strategies we used to surmount them.

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.

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.

Salicylic acid plasma levels following multiple doses of Norgesic Forte and aspirin.

PubMed

Harrison, L I; Kehe, C R; Goldlust, M B; Kvam, D C; Bianchine, J R

1983-01-01

Plasma salicyclic acid levels from the recommended multiple dose regimen of Norgesic Forte (orphenadrine citrate, aspirin, and caffeine) were compared to those from an equivalent multiple dose regimen of aspirin alone in 24 volunteers. The drugs were administered double-blind so that side effects could also be compared. No statistically significant differences were found between Norgesic Forte and aspirin in peak or trough levels, time to peak level, area under the curve, or mean steady-state level of salicylic acid. Mean steady-state levels averaged 154 +/- 46 (+/- SD) and 152 +/- 49 micrograms/ml on days 5 and 10 following Norgesic Forte versus 161 +/- 49 and 154 +/- 47 micrograms/ml following aspirin. Thus, the aspirin in Norgesic Forte provides an anti-inflammatory amount of salicylic acid equivalent to that of plain aspirin. There was no evidence that the combination of orphenadrine citrate, caffeine, and aspirin in Norgesic Forte caused increased or unusual side effects compared with aspirin alone.

Spectro-Temporal Weighting of Loudness

PubMed Central

Oberfeld, Daniel; Heeren, Wiebke; Rennies, Jan; Verhey, Jesko

2012-01-01

Real-world sounds like speech or traffic noise typically exhibit spectro-temporal variability because the energy in different spectral regions evolves differently as a sound unfolds in time. However, it is currently not well understood how the energy in different spectral and temporal portions contributes to loudness. This study investigated how listeners weight different temporal and spectral components of a sound when judging its overall loudness. Spectral weights were measured for the combination of three loudness-matched narrowband noises with different center frequencies. To measure temporal weights, 1,020-ms stimuli were presented, which randomly changed in level every 100 ms. Temporal weights were measured for each narrowband noise separately, and for a broadband noise containing the combination of the three noise bands. Finally, spectro-temporal weights were measured with stimuli where the level of the three narrowband noises randomly and independently changed every 100 ms. The data consistently showed that (i) the first 300 ms of the sounds had a greater influence on overall loudness perception than later temporal portions (primacy effect), and (ii) the lowest noise band contributed significantly more to overall loudness than the higher bands. The temporal weights did not differ between the three frequency bands. Notably, the spectral weights and temporal weights estimated from the conditions with only spectral or only temporal variability were very similar to the corresponding weights estimated in the spectro-temporal condition. The results indicate that the temporal and the spectral weighting of the loudness of a time-varying sound are independent processes. The spectral weights remain constant across time, and the temporal weights do not change across frequency. The results are discussed in the context of current loudness models. PMID:23209670

Time-series panel analysis (TSPA): multivariate modeling of temporal associations in psychotherapy process.

PubMed

Ramseyer, Fabian; Kupper, Zeno; Caspar, Franz; Znoj, Hansjörg; Tschacher, Wolfgang

2014-10-01

Processes occurring in the course of psychotherapy are characterized by the simple fact that they unfold in time and that the multiple factors engaged in change processes vary highly between individuals (idiographic phenomena). Previous research, however, has neglected the temporal perspective by its traditional focus on static phenomena, which were mainly assessed at the group level (nomothetic phenomena). To support a temporal approach, the authors introduce time-series panel analysis (TSPA), a statistical methodology explicitly focusing on the quantification of temporal, session-to-session aspects of change in psychotherapy. TSPA-models are initially built at the level of individuals and are subsequently aggregated at the group level, thus allowing the exploration of prototypical models. TSPA is based on vector auto-regression (VAR), an extension of univariate auto-regression models to multivariate time-series data. The application of TSPA is demonstrated in a sample of 87 outpatient psychotherapy patients who were monitored by postsession questionnaires. Prototypical mechanisms of change were derived from the aggregation of individual multivariate models of psychotherapy process. In a 2nd step, the associations between mechanisms of change (TSPA) and pre- to postsymptom change were explored. TSPA allowed a prototypical process pattern to be identified, where patient's alliance and self-efficacy were linked by a temporal feedback-loop. Furthermore, therapist's stability over time in both mastery and clarification interventions was positively associated with better outcomes. TSPA is a statistical tool that sheds new light on temporal mechanisms of change. Through this approach, clinicians may gain insight into prototypical patterns of change in psychotherapy. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Nonclassicality of Temporal Correlations.

PubMed

Brierley, Stephen; Kosowski, Adrian; Markiewicz, Marcin; Paterek, Tomasz; Przysiężna, Anna

2015-09-18

The results of spacelike separated measurements are independent of distant measurement settings, a property one might call two-way no-signaling. In contrast, timelike separated measurements are only one-way no-signaling since the past is independent of the future but not vice versa. For this reason some temporal correlations that are formally identical to nonclassical spatial correlations can still be modeled classically. We propose a new formulation of Bell's theorem for temporal correlations; namely, we define nonclassical temporal correlations as the ones which cannot be simulated by propagating in time the classical information content of a quantum system given by the Holevo bound. We first show that temporal correlations between results of any projective quantum measurements on a qubit can be simulated classically. Then we present a sequence of general measurements on a single m-level quantum system that cannot be explained by propagating in time an m-level classical system and using classical computers with unlimited memory.

GABA and glutamate levels correlate with MTR and clinical disability: Insights from multiple sclerosis.

PubMed

Nantes, Julia C; Proulx, Sébastien; Zhong, Jidan; Holmes, Scott A; Narayanan, Sridar; Brown, Robert A; Hoge, Richard D; Koski, Lisa

2017-08-15

Converging areas of research have implicated glutamate and γ-aminobutyric acid (GABA) as key players in neuronal signalling and other central functions. Further research is needed, however, to identify microstructural and behavioral links to regional variability in levels of these neurometabolites, particularly in the presence of demyelinating disease. Thus, we sought to investigate the extent to which regional glutamate and GABA levels are related to a neuroimaging marker of microstructural damage and to motor and cognitive performance. Twenty-one healthy volunteers and 47 people with multiple sclerosis (all right-handed) participated in this study. Motor and cognitive abilities were assessed with standard tests used in the study of multiple sclerosis. Proton magnetic resonance spectroscopy data were acquired from sensorimotor and parietal regions of the brains' left cerebral hemisphere using a MEGA-PRESS sequence. Our analysis protocol for the spectroscopy data was designed to account for confounding factors that could contaminate the measurement of neurometabolite levels due to disease, such as the macromolecule signal, partial volume effects, and relaxation effects. Glutamate levels in both regions of interest were lower in people with multiple sclerosis. In the sensorimotor (though not the parietal) region, GABA concentration was higher in the multiple sclerosis group compared to controls. Lower magnetization transfer ratio within grey and white matter regions from which spectroscopy data were acquired was linked to neurometabolite levels. When adjusting for age, normalized brain volume, MTR, total N-acetylaspartate level, and glutamate level, significant relationships were found between lower sensorimotor GABA level and worse performance on several tests, including one of upper limb motor function. This work highlights important methodological considerations relevant to analysis of spectroscopy data, particularly in the afflicted human brain. These findings

Selective attention to temporal features on nested time scales.

PubMed

Henry, Molly J; Herrmann, Björn; Obleser, Jonas

2015-02-01

Meaningful auditory stimuli such as speech and music often vary simultaneously along multiple time scales. Thus, listeners must selectively attend to, and selectively ignore, separate but intertwined temporal features. The current study aimed to identify and characterize the neural network specifically involved in this feature-selective attention to time. We used a novel paradigm where listeners judged either the duration or modulation rate of auditory stimuli, and in which the stimulation, working memory demands, response requirements, and task difficulty were held constant. A first analysis identified all brain regions where individual brain activation patterns were correlated with individual behavioral performance patterns, which thus supported temporal judgments generically. A second analysis then isolated those brain regions that specifically regulated selective attention to temporal features: Neural responses in a bilateral fronto-parietal network including insular cortex and basal ganglia decreased with degree of change of the attended temporal feature. Critically, response patterns in these regions were inverted when the task required selectively ignoring this feature. The results demonstrate how the neural analysis of complex acoustic stimuli with multiple temporal features depends on a fronto-parietal network that simultaneously regulates the selective gain for attended and ignored temporal features. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Sea-Level Trend Uncertainty With Pacific Climatic Variability and Temporally-Correlated Noise

NASA Astrophysics Data System (ADS)

Royston, Sam; Watson, Christopher S.; Legrésy, Benoît; King, Matt A.; Church, John A.; Bos, Machiel S.

2018-03-01

Recent studies have identified climatic drivers of the east-west see-saw of Pacific Ocean satellite altimetry era sea level trends and a number of sea-level trend and acceleration assessments attempt to account for this. We investigate the effect of Pacific climate variability, together with temporally-correlated noise, on linear trend error estimates and determine new time-of-emergence (ToE) estimates across the Indian and Pacific Oceans. Sea-level trend studies often advocate the use of auto-regressive (AR) noise models to adequately assess formal uncertainties, yet sea level often exhibits colored but non-AR(1) noise. Standard error estimates are over- or under-estimated by an AR(1) model for much of the Indo-Pacific sea level. Allowing for PDO and ENSO variability in the trend estimate only reduces standard errors across the tropics and we find noise characteristics are largely unaffected. Of importance for trend and acceleration detection studies, formal error estimates remain on average up to 1.6 times those from an AR(1) model for long-duration tide gauge data. There is an even chance that the observed trend from the satellite altimetry era exceeds the noise in patches of the tropical Pacific and Indian Oceans and the south-west and north-east Pacific gyres. By including climate indices in the trend analysis, the time it takes for the observed linear sea-level trend to emerge from the noise reduces by up to 2 decades.

Coordinated learning of grid cell and place cell spatial and temporal properties: multiple scales, attention and oscillations.

PubMed

Grossberg, Stephen; Pilly, Praveen K

2014-02-05

A neural model proposes how entorhinal grid cells and hippocampal place cells may develop as spatial categories in a hierarchy of self-organizing maps (SOMs). The model responds to realistic rat navigational trajectories by learning both grid cells with hexagonal grid firing fields of multiple spatial scales, and place cells with one or more firing fields, that match neurophysiological data about their development in juvenile rats. Both grid and place cells can develop by detecting, learning and remembering the most frequent and energetic co-occurrences of their inputs. The model's parsimonious properties include: similar ring attractor mechanisms process linear and angular path integration inputs that drive map learning; the same SOM mechanisms can learn grid cell and place cell receptive fields; and the learning of the dorsoventral organization of multiple spatial scale modules through medial entorhinal cortex to hippocampus (HC) may use mechanisms homologous to those for temporal learning through lateral entorhinal cortex to HC ('neural relativity'). The model clarifies how top-down HC-to-entorhinal attentional mechanisms may stabilize map learning, simulates how hippocampal inactivation may disrupt grid cells, and explains data about theta, beta and gamma oscillations. The article also compares the three main types of grid cell models in the light of recent data.

Seeking Temporal Predictability in Speech: Comparing Statistical Approaches on 18 World Languages.

PubMed

Jadoul, Yannick; Ravignani, Andrea; Thompson, Bill; Filippi, Piera; de Boer, Bart

2016-01-01

Temporal regularities in speech, such as interdependencies in the timing of speech events, are thought to scaffold early acquisition of the building blocks in speech. By providing on-line clues to the location and duration of upcoming syllables, temporal structure may aid segmentation and clustering of continuous speech into separable units. This hypothesis tacitly assumes that learners exploit predictability in the temporal structure of speech. Existing measures of speech timing tend to focus on first-order regularities among adjacent units, and are overly sensitive to idiosyncrasies in the data they describe. Here, we compare several statistical methods on a sample of 18 languages, testing whether syllable occurrence is predictable over time. Rather than looking for differences between languages, we aim to find across languages (using clearly defined acoustic, rather than orthographic, measures), temporal predictability in the speech signal which could be exploited by a language learner. First, we analyse distributional regularities using two novel techniques: a Bayesian ideal learner analysis, and a simple distributional measure. Second, we model higher-order temporal structure-regularities arising in an ordered series of syllable timings-testing the hypothesis that non-adjacent temporal structures may explain the gap between subjectively-perceived temporal regularities, and the absence of universally-accepted lower-order objective measures. Together, our analyses provide limited evidence for predictability at different time scales, though higher-order predictability is difficult to reliably infer. We conclude that temporal predictability in speech may well arise from a combination of individually weak perceptual cues at multiple structural levels, but is challenging to pinpoint.

Seeking Temporal Predictability in Speech: Comparing Statistical Approaches on 18 World Languages

PubMed Central

Jadoul, Yannick; Ravignani, Andrea; Thompson, Bill; Filippi, Piera; de Boer, Bart

2016-01-01

Temporal regularities in speech, such as interdependencies in the timing of speech events, are thought to scaffold early acquisition of the building blocks in speech. By providing on-line clues to the location and duration of upcoming syllables, temporal structure may aid segmentation and clustering of continuous speech into separable units. This hypothesis tacitly assumes that learners exploit predictability in the temporal structure of speech. Existing measures of speech timing tend to focus on first-order regularities among adjacent units, and are overly sensitive to idiosyncrasies in the data they describe. Here, we compare several statistical methods on a sample of 18 languages, testing whether syllable occurrence is predictable over time. Rather than looking for differences between languages, we aim to find across languages (using clearly defined acoustic, rather than orthographic, measures), temporal predictability in the speech signal which could be exploited by a language learner. First, we analyse distributional regularities using two novel techniques: a Bayesian ideal learner analysis, and a simple distributional measure. Second, we model higher-order temporal structure—regularities arising in an ordered series of syllable timings—testing the hypothesis that non-adjacent temporal structures may explain the gap between subjectively-perceived temporal regularities, and the absence of universally-accepted lower-order objective measures. Together, our analyses provide limited evidence for predictability at different time scales, though higher-order predictability is difficult to reliably infer. We conclude that temporal predictability in speech may well arise from a combination of individually weak perceptual cues at multiple structural levels, but is challenging to pinpoint. PMID:27994544

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

Spatial and temporal coherence in perceptual binding

PubMed Central

Blake, Randolph; Yang, Yuede

1997-01-01

Component visual features of objects are registered by distributed patterns of activity among neurons comprising multiple pathways and visual areas. How these distributed patterns of activity give rise to unified representations of objects remains unresolved, although one recent, controversial view posits temporal coherence of neural activity as a binding agent. Motivated by the possible role of temporal coherence in feature binding, we devised a novel psychophysical task that requires the detection of temporal coherence among features comprising complex visual images. Results show that human observers can more easily detect synchronized patterns of temporal contrast modulation within hybrid visual images composed of two components when those components are drawn from the same original picture. Evidently, time-varying changes within spatially coherent features produce more salient neural signals. PMID:9192701

Temporal Coordination and Adaptation to Rate Change in Music Performance

ERIC Educational Resources Information Center

Loehr, Janeen D.; Large, Edward W.; Palmer, Caroline

2011-01-01

People often coordinate their actions with sequences that exhibit temporal variability and unfold at multiple periodicities. We compared oscillator- and timekeeper-based accounts of temporal coordination by examining musicians' coordination of rhythmic musical sequences with a metronome that gradually changed rate at the end of a musical phrase…

Physical activity level and medial temporal health in youth at ultra high-risk for psychosis.

PubMed

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

2013-11-01

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, 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 with healthy controls. Total level of physical activity in the UHR group was moderately correlated with 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. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Response of Bacterioplankton Communities to Cadmium Exposure in Coastal Water Microcosms with High Temporal Variability

PubMed Central

Wang, Kai; Xiong, Jinbo; Chen, Xinxin; Zheng, Jialai; Hu, Changju; Yang, Yina; Zhu, Jianlin

2014-01-01

Multiple anthropogenic disturbances to bacterial diversity have been investigated in coastal ecosystems, in which temporal variability in the bacterioplankton community has been considered a ubiquitous process. However, far less is known about the temporal dynamics of a bacterioplankton community responding to pollution disturbances such as toxic metals. We used coastal water microcosms perturbed with 0, 10, 100, and 1,000 μg liter−1 of cadmium (Cd) for 2 weeks to investigate temporal variability, Cd-induced patterns, and their interaction in the coastal bacterioplankton community and to reveal whether the bacterial community structure would reflect the Cd gradient in a temporally varying system. Our results showed that the bacterioplankton community structure shifted along the Cd gradient consistently after a 4-day incubation, although it exhibited some resistance to Cd at low concentration (10 μg liter−1). A process akin to an arms race between temporal variability and Cd exposure was observed, and the temporal variability overwhelmed Cd-induced patterns in the bacterial community. The temporal succession of the bacterial community was correlated with pH, dissolved oxygen, NO3−-N, NO2−-N, PO43−-P, dissolved organic carbon, and chlorophyll a, and each of these parameters contributed more to community variance than Cd did. However, elevated Cd levels did decrease the temporal turnover rate of community. Furthermore, key taxa, affiliated to the families Flavobacteriaceae, Rhodobacteraceae, Erythrobacteraceae, Piscirickettsiaceae, and Alteromonadaceae, showed a high frequency of being associated with Cd levels during 2 weeks. This study provides direct evidence that specific Cd-induced patterns in bacterioplankton communities exist in highly varying manipulated coastal systems. Future investigations on an ecosystem scale across longer temporal scales are needed to validate the observed pattern. PMID:25326310

A level set method for multiple sclerosis lesion segmentation.

PubMed

Zhao, Yue; Guo, Shuxu; Luo, Min; Shi, Xue; Bilello, Michel; Zhang, Shaoxiang; Li, Chunming

2018-06-01

In this paper, we present a level set method for multiple sclerosis (MS) lesion segmentation from FLAIR images in the presence of intensity inhomogeneities. We use a three-phase level set formulation of segmentation and bias field estimation to segment MS lesions and normal tissue region (including GM and WM) and CSF and the background from FLAIR images. To save computational load, we derive a two-phase formulation from the original multi-phase level set formulation to segment the MS lesions and normal tissue regions. The derived method inherits the desirable ability to precisely locate object boundaries of the original level set method, which simultaneously performs segmentation and estimation of the bias field to deal with intensity inhomogeneity. Experimental results demonstrate the advantages of our method over other state-of-the-art methods in terms of segmentation accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Brain-derived neurotrophic factor levels under chronic natalizumab treatment in multiple sclerosis. A preliminary report.

PubMed

Văcăraş, Vitalie; Major, Zoltán Zsigmond; Buzoianu, Anca Dana

Our main purpose was to investigate if the chronic treatment with the disease-modifying drug natalizumab shows quantifiable effect on BDNF levels in multiple sclerosis patients. BDNF plasma concentration was evaluated using enzyme-linked immunosorbent assay in healthy individuals, not treated multiple sclerosis patients and patients treated with natalizumab. Multiple sclerosis patients have a significantly lower amount of peripheral BDNF than healthy individuals. Patients treated with natalizumab have significantly higher BDNF levels than not treated patients. Chronic natalizumab treatment is associated with significantly increased plasma BDNF concentration in multiple sclerosis. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

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.

[AIDS and level of education in Brazil: temporal evolution from 1986 to 1996].

PubMed

Fonseca, M G; Bastos, F I; Derrico, M; Andrade, C L; Travassos, C; Szwarcwald, C L

2000-01-01

This article analyzes the temporal distribution of reported AIDS cases by level of education used as a proxy variable for individual socioeconomic status. All AIDS cases aged 20-69 years and reported through May 29, 1999, with date of diagnosis between 1986-1996, were included in the study. Incidence rates were calculated for men and women according to level of education ("level 1" up to 8 years of schooling and "level 2" with over 8 years of schooling), by five geographic regions, and by year of diagnosis. Incidence rates for men with less schooling were close to or higher than those for men with more schooling (particularly in the Southeast region). For women, a time series showed that incidence rates increased at a higher rate among women with less schooling in all regions of the country; in the Southeast, the incidence rate for women with less schooling was already greater than for women with more schooling by 1989. According to the present analysis, the AIDS epidemic in Brazil began among people from the more highly educated social strata and progressed steadily through to the less educated social strata, especially among women.

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.

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.…

Contributions of primate prefrontal cortex and medial temporal lobe to temporal-order memory.

PubMed

Naya, Yuji; Chen, He; Yang, Cen; Suzuki, Wendy A

2017-12-19

Neuropsychological and neurophysiological studies have emphasized the role of the prefrontal cortex (PFC) in maintaining information about the temporal order of events or items for upcoming actions. However, the medial temporal lobe (MTL) has also been considered critical to bind individual events or items to their temporal context in episodic memory. Here we characterize the contributions of these brain areas by comparing single-unit activity in the dorsal and ventral regions of macaque lateral PFC (d-PFC and v-PFC) with activity in MTL areas including the hippocampus (HPC), entorhinal cortex, and perirhinal cortex (PRC) as well as in area TE during the encoding phase of a temporal-order memory task. The v-PFC cells signaled specific items at particular time periods of the task. By contrast, MTL cortical cells signaled specific items across multiple time periods and discriminated the items between time periods by modulating their firing rates. Analysis of the temporal dynamics of these signals showed that the conjunctive signal of item and temporal-order information in PRC developed earlier than that seen in v-PFC. During the delay interval between the two cue stimuli, while v-PFC provided prominent stimulus-selective delay activity, MTL areas did not. Both regions of PFC and HPC exhibited an incremental timing signal that appeared to represent the continuous passage of time during the encoding phase. However, the incremental timing signal in HPC was more prominent than that observed in PFC. These results suggest that PFC and MTL contribute to the encoding of the integration of item and timing information in distinct ways.

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.

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.

Multiplicative Forests for Continuous-Time Processes.

PubMed

Weiss, Jeremy C; Natarajan, Sriraam; Page, David

2012-01-01

Learning temporal dependencies between variables over continuous time is an important and challenging task. Continuous-time Bayesian networks effectively model such processes but are limited by the number of conditional intensity matrices, which grows exponentially in the number of parents per variable. We develop a partition-based representation using regression trees and forests whose parameter spaces grow linearly in the number of node splits. Using a multiplicative assumption we show how to update the forest likelihood in closed form, producing efficient model updates. Our results show multiplicative forests can be learned from few temporal trajectories with large gains in performance and scalability.

Neuroactive steroid levels in plasma and cerebrospinal fluid of male multiple sclerosis patients.

PubMed

Caruso, Donatella; Melis, Marta; Fenu, Giuseppe; Giatti, Silvia; Romano, Simone; Grimoldi, Maria; Crippa, Donatella; Marrosu, Maria Giovanna; Cavaletti, Guido; Melcangi, Roberto Cosimo

2014-08-01

Neuroactive steroid family includes molecules synthesized in peripheral glands (i.e., hormonal steroids) and directly in the nervous system (i.e., neurosteroids) which are key regulators of the nervous function. As already reported in clinical and experimental studies, neurodegenerative diseases affect the levels of neuroactive steroids. However, a careful analysis comparing the levels of these molecules in cerebrospinal fluid (CSF) and in plasma of multiple sclerosis (MS) patients is still missing. To this aim, the levels of neuroactive steroids were evaluated by liquid chromatography-tandem mass spectrometry in CSF and plasma of male adults affected by Relapsing-Remitting MS and compared with those collected in control patients. An increase in pregnenolone and isopregnanolone levels associated with a decrease in progesterone metabolites, dihydroprogesterone, and tetrahydroprogesterone was observed in CSF of MS patients. Moreover, an increase of 5α-androstane-3α,17β-diol and of 17β-estradiol levels associated with a decrease of dihydrotestosterone also occurred. In plasma, an increase in pregnenolone, progesterone, and dihydrotestosterone and a decrease in dihydroprogesterone and tetrahydroprogesterone levels were reported. This study shows for the first time that the levels of several neuroactive steroids, and particularly those of progesterone and testosterone metabolites, are deeply affected in CSF of relapsing-remitting MS male patients. We here demonstrated that, the cerebrospinal fluid and plasma levels of several neuroactive steroids are modified in relapsing remitting multiple sclerosis male patients. Interestingly, we reported for the first time that, the levels of progesterone and testosterone metabolites are deeply affected in cerebrospinal fluid. These findings may have an important relevance in therapeutic and/or diagnostic field of multiple sclerosis. © 2014 International Society for Neurochemistry.

Task-Dependent Behavioral Dynamics Make the Case for Temporal Integration in Multiple Strategies during Odor Processing

PubMed Central

Brown, Austin; Mehta, Nisarg; Vujovic, Mark; Amina, Tasneem; Fixsen, Bethany

2017-01-01

Differing results in olfactory-based decision-making research regarding the amount of time that rats and mice use to identify odors have led to some disagreements about odor-processing mechanics, including whether or not rodents use temporal integration (i.e., sniffing longer to identify odors better). Reported differences in behavioral strategies may be due to the different types of tasks used in different laboratories. Some researchers have reported that animals performing two-alternative choice (TAC) tasks need only 1–2 sniffs and do not increase performance with longer sampling. Others have reported that animals performing go/no-go (GNG) tasks increase sampling times and performance for difficult discriminations, arguing for temporal integration. We present results from four experiments comparing GNG and TAC tasks over several behavioral variables (e.g., performance, sampling duration). When rats know only one task, they perform better in GNG than in TAC. However, performance was not statistically different when rats learned and were tested in both tasks. Rats sample odors longer in GNG than in TAC, even when they know both tasks and perform them in the same or different sessions. Longer sampling is associated with better performance for both tasks in difficult discriminations, which supports the case for temporal integration over ≥2–6 sniffs in both tasks. These results illustrate that generalizations from a single task about behavioral or cognitive abilities (e.g., processing, perception) do not capture the full range of complexity and can significantly impact inferences about general abilities in sensory perception. SIGNIFICANCE STATEMENT Behavioral tasks and training and testing history affect measured outcomes in cognitive tests. Rats sample odors longer in a go/no-go (GNG) than in a two-alternative choice (TAC) task, performing better in GNG unless they know both tasks. Odor-sampling time is extended in both tasks when the odors to be discriminated

A framework for combining multiple soil moisture retrievals based on maximizing temporal correlation

NASA Astrophysics Data System (ADS)

Kim, Seokhyeon; Parinussa, Robert M.; Liu, Yi. Y.; Johnson, Fiona M.; Sharma, Ashish

2015-08-01

A method for combining two microwave satellite soil moisture products by maximizing the temporal correlation with a reference data set has been developed. The method was applied to two global soil moisture data sets, Japan Aerospace Exploration Agency (JAXA) and Land Parameter Retrieval Model (LPRM), retrieved from the Advanced Microwave Scanning Radiometer 2 observations for the period 2012-2014. A global comparison revealed superior results of the combined product compared to the individual products against the reference data set of ERA-Interim volumetric water content. The global mean temporal correlation coefficient of the combined product with this reference was 0.52 which outperforms the individual JAXA (0.35) as well as the LPRM (0.45) product. Additionally, the performance was evaluated against in situ observations from the International Soil Moisture Network. The combined data set showed a significant improvement in temporal correlation coefficients in the validation compared to JAXA and minor improvements for the LPRM product.

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.

Method for generating maximally entangled states of multiple three-level atoms in cavity QED

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin Guangsheng; Li Shushen; Feng Songlin

2004-03-01

We propose a scheme to generate maximally entangled states (MESs) of multiple three-level atoms in microwave cavity QED based on the resonant atom-cavity interaction. In the scheme, multiple three-level atoms initially in their ground states are sequently sent through two suitably prepared cavities. After a process of appropriate atom-cavity interaction, a subsequent measurement on the second cavity field projects the atoms onto the MESs. The practical feasibility of this method is also discussed.

Microencephaloceles: another dual pathology of intractable temporal lobe epilepsy in childhood.

PubMed

Aquilina, Kristian; Clarke, Dave F; Wheless, James W; Boop, Frederick A

2010-04-01

Temporal lobe encephaloceles can be associated with temporal lobe epilepsy. The authors report on the case of an adolescent with multiple microencephaloceles, in the anterolateral middle fossa floor, identified at surgery (temporal lobectomy) for intractable partial-onset seizures of temporal origin. Magnetic resonance imaging revealed only hippocampal atrophy. Subdural electrodes demonstrated ictal activity arising primarily from the anterior and lateral temporal lobe, close to the microencephaloceles, spreading to the anterior and posterior mesial structures. Pathological examination revealed diffuse temporal gliosis involving the hippocampus, together with microdysgenesis of the amygdala. The literature on epilepsy secondary to encephaloceles is reviewed and the contribution of the microencephaloceles to the seizure disorder in this patient is discussed.

Sequential detection of temporal communities by estrangement confinement.

PubMed

Kawadia, Vikas; Sreenivasan, Sameet

2012-01-01

Temporal communities are the result of a consistent partitioning of nodes across multiple snapshots of an evolving network, and they provide insights into how dense clusters in a network emerge, combine, split and decay over time. To reliably detect temporal communities we need to not only find a good community partition in a given snapshot but also ensure that it bears some similarity to the partition(s) found in the previous snapshot(s), a particularly difficult task given the extreme sensitivity of community structure yielded by current methods to changes in the network structure. Here, motivated by the inertia of inter-node relationships, we present a new measure of partition distance called estrangement, and show that constraining estrangement enables one to find meaningful temporal communities at various degrees of temporal smoothness in diverse real-world datasets. Estrangement confinement thus provides a principled approach to uncovering temporal communities in evolving networks.

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.

Multiplicative Forests for Continuous-Time Processes

PubMed Central

Weiss, Jeremy C.; Natarajan, Sriraam; Page, David

2013-01-01

Learning temporal dependencies between variables over continuous time is an important and challenging task. Continuous-time Bayesian networks effectively model such processes but are limited by the number of conditional intensity matrices, which grows exponentially in the number of parents per variable. We develop a partition-based representation using regression trees and forests whose parameter spaces grow linearly in the number of node splits. Using a multiplicative assumption we show how to update the forest likelihood in closed form, producing efficient model updates. Our results show multiplicative forests can be learned from few temporal trajectories with large gains in performance and scalability. PMID:25284967

Effects of ACL Reconstructive Surgery on Temporal Variations of Cytokine Levels in Synovial Fluid

PubMed Central

Bigoni, Marco; Gandolla, Marta; Sacerdote, Paola; Piatti, Massimiliano; Castelnuovo, Alberto; Franchi, Silvia; Gorla, Massimo; Munegato, Daniele; Gaddi, Diego; Pedrocchi, Alessandra; Omeljaniuk, Robert J.; Locatelli, Vittorio; Torsello, Antonio

2016-01-01

Anterior cruciate ligament (ACL) reconstruction restores knee stability but does not reduce the incidence of posttraumatic osteoarthritis induced by inflammatory cytokines. The aim of this research was to longitudinally measure IL-1β, IL-6, IL-8, IL-10, and TNF-α levels in patients subjected to ACL reconstruction using bone-patellar tendon-bone graft. Synovial fluid was collected within 24–72 hours of ACL rupture (acute), 1 month after injury immediately prior to surgery (presurgery), and 1 month thereafter (postsurgery). For comparison, a “control” group consisted of individuals presenting chronic ACL tears. Our results indicate that levels of IL-6, IL-8, and IL-10 vary significantly over time in reconstruction patients. In the acute phase, the levels of these cytokines in reconstruction patients were significantly greater than those in controls. In the presurgery phase, cytokine levels in reconstruction patients were reduced and comparable with those in controls. Finally, cytokine levels increased again with respect to control group in the postsurgery phase. The levels of IL-1β and TNF-α showed no temporal variation. Our data show that the history of an ACL injury, including trauma and reconstruction, has a significant impact on levels of IL-6, IL-8, and IL-10 in synovial fluid but does not affect levels of TNF-α and IL-1β. PMID:27313403

Effects of ACL Reconstructive Surgery on Temporal Variations of Cytokine Levels in Synovial Fluid.

PubMed

Bigoni, Marco; Turati, Marco; Gandolla, Marta; Sacerdote, Paola; Piatti, Massimiliano; Castelnuovo, Alberto; Franchi, Silvia; Gorla, Massimo; Munegato, Daniele; Gaddi, Diego; Pedrocchi, Alessandra; Omeljaniuk, Robert J; Locatelli, Vittorio; Torsello, Antonio

2016-01-01

Anterior cruciate ligament (ACL) reconstruction restores knee stability but does not reduce the incidence of posttraumatic osteoarthritis induced by inflammatory cytokines. The aim of this research was to longitudinally measure IL-1β, IL-6, IL-8, IL-10, and TNF-α levels in patients subjected to ACL reconstruction using bone-patellar tendon-bone graft. Synovial fluid was collected within 24-72 hours of ACL rupture (acute), 1 month after injury immediately prior to surgery (presurgery), and 1 month thereafter (postsurgery). For comparison, a "control" group consisted of individuals presenting chronic ACL tears. Our results indicate that levels of IL-6, IL-8, and IL-10 vary significantly over time in reconstruction patients. In the acute phase, the levels of these cytokines in reconstruction patients were significantly greater than those in controls. In the presurgery phase, cytokine levels in reconstruction patients were reduced and comparable with those in controls. Finally, cytokine levels increased again with respect to control group in the postsurgery phase. The levels of IL-1β and TNF-α showed no temporal variation. Our data show that the history of an ACL injury, including trauma and reconstruction, has a significant impact on levels of IL-6, IL-8, and IL-10 in synovial fluid but does not affect levels of TNF-α and IL-1β.

Classification and Weakly Supervised Pain Localization using Multiple Segment Representation.

PubMed

Sikka, Karan; Dhall, Abhinav; Bartlett, Marian Stewart

2014-10-01

Automatic pain recognition from videos is a vital clinical application and, owing to its spontaneous nature, poses interesting challenges to automatic facial expression recognition (AFER) research. Previous pain vs no-pain systems have highlighted two major challenges: (1) ground truth is provided for the sequence, but the presence or absence of the target expression for a given frame is unknown, and (2) the time point and the duration of the pain expression event(s) in each video are unknown. To address these issues we propose a novel framework (referred to as MS-MIL) where each sequence is represented as a bag containing multiple segments, and multiple instance learning (MIL) is employed to handle this weakly labeled data in the form of sequence level ground-truth. These segments are generated via multiple clustering of a sequence or running a multi-scale temporal scanning window, and are represented using a state-of-the-art Bag of Words (BoW) representation. This work extends the idea of detecting facial expressions through 'concept frames' to 'concept segments' and argues through extensive experiments that algorithms such as MIL are needed to reap the benefits of such representation. The key advantages of our approach are: (1) joint detection and localization of painful frames using only sequence-level ground-truth, (2) incorporation of temporal dynamics by representing the data not as individual frames but as segments, and (3) extraction of multiple segments, which is well suited to signals with uncertain temporal location and duration in the video. Extensive experiments on UNBC-McMaster Shoulder Pain dataset highlight the effectiveness of the approach by achieving competitive results on both tasks of pain classification and localization in videos. We also empirically evaluate the contributions of different components of MS-MIL. The paper also includes the visualization of discriminative facial patches, important for pain detection, as discovered by our

Reliability of MEG source imaging of anterior temporal spikes: analysis of an intracranially characterized spike focus.

PubMed

Wennberg, Richard; Cheyne, Douglas

2014-05-01

To assess the reliability of MEG source imaging (MSI) of anterior temporal spikes through detailed analysis of the localization and orientation of source solutions obtained for a large number of spikes that were separately confirmed by intracranial EEG to be focally generated within a single, well-characterized spike focus. MSI was performed on 64 identical right anterior temporal spikes from an anterolateral temporal neocortical spike focus. The effects of different volume conductors (sphere and realistic head model), removal of noise with low frequency filters (LFFs) and averaging multiple spikes were assessed in terms of the reliability of the source solutions. MSI of single spikes resulted in scattered dipole source solutions that showed reasonable reliability for localization at the lobar level, but only for solutions with a goodness-of-fit exceeding 80% using a LFF of 3 Hz. Reliability at a finer level of intralobar localization was limited. Spike averaging significantly improved the reliability of source solutions and averaging 8 or more spikes reduced dependency on goodness-of-fit and data filtering. MSI performed on topographically identical individual spikes from an intracranially defined classical anterior temporal lobe spike focus was limited by low reliability (i.e., scattered source solutions) in terms of fine, sublobar localization within the ipsilateral temporal lobe. Spike averaging significantly improved reliability. MSI performed on individual anterior temporal spikes is limited by low reliability. Reduction of background noise through spike averaging significantly improves the reliability of MSI solutions. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Quantifying Temporal Autocorrelations for the Expression of Geobacter species mRNA Gene Transcripts at Variable Ammonium Levels during in situ U(VI) Bioremediation

NASA Astrophysics Data System (ADS)

Mouser, P. J.

2010-12-01

In order to develop decision-making tools for the prediction and optimization of subsurface bioremediation strategies, we must be able to link the molecular-scale activity of microorganisms involved in remediation processes with biogeochemical processes observed at the field-scale. This requires the ability to quantify changes in the in situ metabolic condition of dominant microbes and associate these changes to fluctuations in nutrient levels throughout the bioremediation process. It also necessitates a need to understand the spatiotemporal variability of the molecular-scale information to develop meaningful parameters and constraint ranges in complex bio-physio-chemical models. The expression of three Geobacter species genes (ammonium transporter (amtB), nitrogen fixation (nifD), and a housekeeping gene (recA)) were tracked at two monitoring locations that differed significantly in ammonium (NH4+) concentrations during a field-scale experiment where acetate was injected into the subsurface to simulate Geobacteraceae in a uranium-contaminated aquifer. Analysis of amtB and nifD mRNA transcript levels indicated that NH4+ was the primary form of fixed nitrogen during bioremediation. Overall expression levels of amtB were on average 8-fold higher at NH4+ concentrations of 300 μM or more than at lower NH4+ levels (average 60 μM). The degree of temporal correlation in Geobacter species mRNA expression levels was calculated at both locations using autocorrelation methods that describe the relationship between sample semi-variance and time lag. At the monitoring location with lower NH4+, a temporal correlation lag of 8 days was observed for both amtB and nifD transcript patterns. At the location where higher NH4+ levels were observed, no discernable temporal correlation lag above the sampling frequency (approximately every 2 days) was observed for amtB or nifD transcript fluctuations. Autocorrelation trends in recA expression levels at both locations indicated that

Multivariate space-time modelling of multiple air pollutants and their health effects accounting for exposure uncertainty.

PubMed

Huang, Guowen; Lee, Duncan; Scott, E Marian

2018-03-30

The long-term health effects of air pollution are often estimated using a spatio-temporal ecological areal unit study, but this design leads to the following statistical challenges: (1) how to estimate spatially representative pollution concentrations for each areal unit; (2) how to allow for the uncertainty in these estimated concentrations when estimating their health effects; and (3) how to simultaneously estimate the joint effects of multiple correlated pollutants. This article proposes a novel 2-stage Bayesian hierarchical model for addressing these 3 challenges, with inference based on Markov chain Monte Carlo simulation. The first stage is a multivariate spatio-temporal fusion model for predicting areal level average concentrations of multiple pollutants from both monitored and modelled pollution data. The second stage is a spatio-temporal model for estimating the health impact of multiple correlated pollutants simultaneously, which accounts for the uncertainty in the estimated pollution concentrations. The novel methodology is motivated by a new study of the impact of both particulate matter and nitrogen dioxide concentrations on respiratory hospital admissions in Scotland between 2007 and 2011, and the results suggest that both pollutants exhibit substantial and independent health effects. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

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.

Instantiating the multiple levels of analysis perspective in a program of study on externalizing behavior

PubMed Central

Beauchaine, Theodore P.; Gatzke-Kopp, Lisa M.

2014-01-01

During the last quarter century, developmental psychopathology has become increasingly inclusive and now spans disciplines ranging from psychiatric genetics to primary prevention. As a result, developmental psychopathologists have extended traditional diathesis–stress and transactional models to include causal processes at and across all relevant levels of analysis. Such research is embodied in what is known as the multiple levels of analysis perspective. We describe how multiple levels of analysis research has informed our current thinking about antisocial and borderline personality development among trait impulsive and therefore vulnerable individuals. Our approach extends the multiple levels of analysis perspective beyond simple Biology × Environment interactions by evaluating impulsivity across physiological systems (genetic, autonomic, hormonal, neural), psychological constructs (social, affective, motivational), developmental epochs (preschool, middle childhood, adolescence, adulthood), sexes (male, female), and methods of inquiry (self-report, informant report, treatment outcome, cardiovascular, electrophysiological, neuroimaging). By conducting our research using any and all available methods across these levels of analysis, we have arrived at a developmental model of trait impulsivity that we believe confers a greater understanding of this highly heritable trait and captures at least some heterogeneity in key behavioral outcomes, including delinquency and suicide. PMID:22781868

Evolutions Of Diff-Tomo For Sensing Subcanopy Deformations And Height-Varying Temporal Coherence

NASA Astrophysics Data System (ADS)

Lombardini, Fabrizio; Cai, Francesco

2012-01-01

Interest is continuing to grow in advanced interferometric SAR methods for sensing complex scenarios with multiple (layover or volumetric) scatterers mapped in the SAR cell. Multibaseline SAR tomographic (3D) elevation beam forming is a promising technique in this field. Recently, the Tomo concept has been integrated with the differential interferometry concept, producing the advanced “differential tomography” (Diff-Tomo, “4D”) processing mode which furnishes “space-time” signatures of multiple scatterer dynamics in the SAR cell. Advances in the application of this new framework are investigated for complex volume scattering scenarios including temporal signal variations, both from scatterer temporal decorrelation and deformation motions. In particular, new results are reported concerning the potentials of Diff-Tomo for the analysis of forest scenarios, based on the original concept of the space-time signatures of temporal decorrelation. E-SAR P-band data results are expanded of tomography robust to temporal decorrelation, and first trials are reported of separation of different temporal decorrelation mechanisms of canopy and ground, and of sensing possible sub-canopy subsidences.

Generation of mammalian cells stably expressing multiple genes at predetermined levels.

PubMed

Liu, X; Constantinescu, S N; Sun, Y; Bogan, J S; Hirsch, D; Weinberg, R A; Lodish, H F

2000-04-10

Expression of cloned genes at desired levels in cultured mammalian cells is essential for studying protein function. Controlled levels of expression have been difficult to achieve, especially for cell lines with low transfection efficiency or when expression of multiple genes is required. An internal ribosomal entry site (IRES) has been incorporated into many types of expression vectors to allow simultaneous expression of two genes. However, there has been no systematic quantitative analysis of expression levels in individual cells of genes linked by an IRES, and thus the broad use of these vectors in functional analysis has been limited. We constructed a set of retroviral expression vectors containing an IRES followed by a quantitative selectable marker such as green fluorescent protein (GFP) or truncated cell surface proteins CD2 or CD4. The gene of interest is placed in a multiple cloning site 5' of the IRES sequence under the control of the retroviral long terminal repeat (LTR) promoter. These vectors exploit the approximately 100-fold differences in levels of expression of a retrovirus vector depending on its site of insertion in the host chromosome. We show that the level of expression of the gene downstream of the IRES and the expression level and functional activity of the gene cloned upstream of the IRES are highly correlated in stably infected target cells. This feature makes our vectors extremely useful for the rapid generation of stably transfected cell populations or clonal cell lines expressing specific amounts of a desired protein simply by fluorescent activated cell sorting (FACS) based on the level of expression of the gene downstream of the IRES. We show how these vectors can be used to generate cells expressing high levels of the erythropoietin receptor (EpoR) or a dominant negative Smad3 protein and to generate cells expressing two different cloned proteins, Ski and Smad4. Correlation of a biologic effect with the level of expression of the

TEMPORAL EVOLUTION OF MULTIPLE EVAPORATING RIBBON SOURCES IN A SOLAR FLARE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graham, D. R.; Cauzzi, G., E-mail: dgraham@arcetri.astro.it

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}more » 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.« less

STRAD Wheel: Web-Based Library for Visualizing Temporal Data.

PubMed

Fernondez-Prieto, Diana; Naranjo-Valero, Carol; Hernandez, Jose Tiberio; Hagen, Hans

2017-01-01

Recent advances in web development, including the introduction of HTML5, have opened a door for visualization researchers and developers to quickly access larger audiences worldwide. Open source libraries for the creation of interactive visualizations are becoming more specialized but also modular, which makes them easy to incorporate in domain-specific applications. In this context, the authors developed STRAD (Spatio-Temporal-Radar) Wheel, a web-based library that focuses on the visualization and interactive query of temporal data in a compact view with multiple temporal granularities. This article includes two application examples in urban planning to help illustrate the proposed visualization's use in practice.

EliXR-TIME: A Temporal Knowledge Representation for Clinical Research Eligibility Criteria.

PubMed

Boland, Mary Regina; Tu, Samson W; Carini, Simona; Sim, Ida; Weng, Chunhua

2012-01-01

Effective clinical text processing requires accurate extraction and representation of temporal expressions. Multiple temporal information extraction models were developed but a similar need for extracting temporal expressions in eligibility criteria (e.g., for eligibility determination) remains. We identified the temporal knowledge representation requirements of eligibility criteria by reviewing 100 temporal criteria. We developed EliXR-TIME, a frame-based representation designed to support semantic annotation for temporal expressions in eligibility criteria by reusing applicable classes from well-known clinical temporal knowledge representations. We used EliXR-TIME to analyze a training set of 50 new temporal eligibility criteria. We evaluated EliXR-TIME using an additional random sample of 20 eligibility criteria with temporal expressions that have no overlap with the training data, yielding 92.7% (76 / 82) inter-coder agreement on sentence chunking and 72% (72 / 100) agreement on semantic annotation. We conclude that this knowledge representation can facilitate semantic annotation of the temporal expressions in eligibility criteria.

Physics of cardiac imaging with multiple-row detector CT.

PubMed

Mahesh, Mahadevappa; Cody, Dianna D

2007-01-01

Cardiac imaging with multiple-row detector computed tomography (CT) has become possible due to rapid advances in CT technologies. Images with high temporal and spatial resolution can be obtained with multiple-row detector CT scanners; however, the radiation dose associated with cardiac imaging is high. Understanding the physics of cardiac imaging with multiple-row detector CT scanners allows optimization of cardiac CT protocols in terms of image quality and radiation dose. Knowledge of the trade-offs between various scan parameters that affect image quality--such as temporal resolution, spatial resolution, and pitch--is the key to optimized cardiac CT protocols, which can minimize the radiation risks associated with these studies. Factors affecting temporal resolution include gantry rotation time, acquisition mode, and reconstruction method; factors affecting spatial resolution include detector size and reconstruction interval. Cardiac CT has the potential to become a reliable tool for noninvasive diagnosis and prevention of cardiac and coronary artery disease. (c) RSNA, 2007.

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

Role of mastoid pneumatization in temporal bone fractures.

PubMed

Ilea, A; Butnaru, A; Sfrângeu, S A; Hedeşiu, M; Dudescu, C M; Berce, P; Chezan, H; Hurubeanu, L; Trombiţaş, V E; Câmpian, R S; Albu, S

2014-07-01

The mastoid portion of the temporal bone has multiple functional roles in the organism, including regulation of pressure in the middle ear and protection of the inner ear. We investigated whether mastoid pneumatization plays a role in the protection of vital structures in the temporal bone during direct lateral trauma. The study was performed on 20 human temporal bones isolated from cadavers. In the study group formed by 10 temporal bone samples, mastoid cells were removed and the resulting neocavities were filled. The mastoids were maintained intact in the control group. All samples were impacted at the same speed and kinetic energy. The resultant temporal bone fractures were evaluated by CT. Temporal squama fractures were 2.88 times more frequent, and mastoid fractures were 2.76 times more frequent in the study group. Facial nerve canal fractures were 6 times more frequent in the study group and involved all the segments of the facial nerve. Carotid canal fractures and jugular foramen fractures were 2.33 and 2.5 times, respectively, more frequent in the study group. The mastoid portion of the temporal bone plays a role in the absorption and dispersion of kinetic energy during direct lateral trauma to the temporal bone, reducing the incidence of fracture in the setting of direct trauma. © 2014 by American Journal of Neuroradiology.

Determination of multiple mycotoxins levels in poultry feeds from Cameroon.

PubMed

Abia, Wilfred Angie; Simo, Grace Nella; Warth, Benedikt; Sulyok, Michael; Krska, Rudolf; Tchana, Angele; Moundipa, Paul Fewou

2013-02-01

For the first time in Cameroon, this paper reports on multiple mycotoxins occurrences in poultry feeds. Twenty feed samples collected from different poultry farms were analyzed for 320 fungal metabolites by liquid chromatography electrospray ionization tandem mass spectrometry. Results showed feeds contamination by 68 metabolites including 18 mycotoxins/metabolites currently regulated in the European Union such as fumonisins B1 (FB1), B2, and B3; deoxynevalenol (DON); and beta-zearalenol recovered in all samples. FB1 reported highest FB mean level of 468 (range 16-1930) microg kg(-1). Levels of DON and ZEN were mostly concentrated in feeds from western-highlands conversely for FBs and aflatoxins concentrations in Yaounde. Aflatoxin B1 mean level of 40 microg kg(-1) exceeded the worldwide permitted limit for aflatoxins in feed and generally inversely proportional to weight gain in chicken.

Effects of temporal correlations in social multiplex networks.

PubMed

Starnini, Michele; Baronchelli, Andrea; Pastor-Satorras, Romualdo

2017-08-17

Multi-layered networks represent a major advance in the description of natural complex systems, and their study has shed light on new physical phenomena. Despite its importance, however, the role of the temporal dimension in their structure and function has not been investigated in much detail so far. Here we study the temporal correlations between layers exhibited by real social multiplex networks. At a basic level, the presence of such correlations implies a certain degree of predictability in the contact pattern, as we quantify by an extension of the entropy and mutual information analyses proposed for the single-layer case. At a different level, we demonstrate that temporal correlations are a signature of a 'multitasking' behavior of network agents, characterized by a higher level of switching between different social activities than expected in a uncorrelated pattern. Moreover, temporal correlations significantly affect the dynamics of coupled epidemic processes unfolding on the network. Our work opens the way for the systematic study of temporal multiplex networks and we anticipate it will be of interest to researchers in a broad array of fields.

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.

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

Attractive faces temporally modulate visual attention

PubMed Central

Nakamura, Koyo; Kawabata, Hideaki

2014-01-01

Facial attractiveness is an important biological and social signal on social interaction. Recent research has demonstrated that an attractive face captures greater spatial attention than an unattractive face does. Little is known, however, about the temporal characteristics of visual attention for facial attractiveness. In this study, we investigated the temporal modulation of visual attention induced by facial attractiveness by using a rapid serial visual presentation. Fourteen male faces and two female faces were successively presented for 160 ms, respectively, and participants were asked to identify two female faces embedded among a series of multiple male distractor faces. Identification of a second female target (T2) was impaired when a first target (T1) was attractive compared to neutral or unattractive faces, at 320 ms stimulus onset asynchrony (SOA); identification was improved when T1 was attractive compared to unattractive faces at 640 ms SOA. These findings suggest that the spontaneous appraisal of facial attractiveness modulates temporal attention. PMID:24994994

Temporal abstraction and temporal Bayesian networks in clinical domains: a survey.

PubMed

Orphanou, Kalia; Stassopoulou, Athena; Keravnou, Elpida

2014-03-01

Temporal abstraction (TA) of clinical data aims to abstract and interpret clinical data into meaningful higher-level interval concepts. Abstracted concepts are used for diagnostic, prediction and therapy planning purposes. On the other hand, temporal Bayesian networks (TBNs) are temporal extensions of the known probabilistic graphical models, Bayesian networks. TBNs can represent temporal relationships between events and their state changes, or the evolution of a process, through time. This paper offers a survey on techniques/methods from these two areas that were used independently in many clinical domains (e.g. diabetes, hepatitis, cancer) for various clinical tasks (e.g. diagnosis, prognosis). A main objective of this survey, in addition to presenting the key aspects of TA and TBNs, is to point out important benefits from a potential integration of TA and TBNs in medical domains and tasks. The motivation for integrating these two areas is their complementary function: TA provides clinicians with high level views of data while TBNs serve as a knowledge representation and reasoning tool under uncertainty, which is inherent in all clinical tasks. Key publications from these two areas of relevance to clinical systems, mainly circumscribed to the latest two decades, are reviewed and classified. TA techniques are compared on the basis of: (a) knowledge acquisition and representation for deriving TA concepts and (b) methodology for deriving basic and complex temporal abstractions. TBNs are compared on the basis of: (a) representation of time, (b) knowledge representation and acquisition, (c) inference methods and the computational demands of the network, and (d) their applications in medicine. The survey performs an extensive comparative analysis to illustrate the separate merits and limitations of various TA and TBN techniques used in clinical systems with the purpose of anticipating potential gains through an integration of the two techniques, thus leading to a

Spectral splitting of optical pulses inside a dispersive medium at a temporal boundary

DOE PAGES

Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

2016-11-07

We show numerically that the spectrum of an optical pulse splits into multiple, widely separated, spectral bands when it arrives at a temporal boundary across which refractive index changes suddenly. At the same time, the pulse breaks into several temporally separated pulses traveling at different speeds. The number of such pulses depends on the dispersive properties of the medium. We study the effect of second- and third-order dispersion in detail but also consider briefly the impact of other higher-order terms. As a result, a temporal waveguide formed with two temporal boundaries can reflect the temporally separated pulses again and again,more » increasing the number of pulses trapped within the temporal waveguide.« less

Prevalence of Temporal Bone Fractures in Patients with Mandibular Fractures Using Multidetector-Row CT.

PubMed

Ogura, I; Kaneda, T; Sasaki, Y; Buch, K; Sakai, O

2015-06-01

Temporal bone fracture after mandibular trauma is thought to be rare, and its prevalence has not been reported in the literature. The purpose of this study was to investigate the prevalence of temporal bone fractures in patients with mandibular fractures and the relationship between temporal bone fractures and the mandibular fracture location using multidetector-row computed tomography (MDCT). A prospective study was performed in 201 patients with mandibular fractures who underwent 64-MDCT scans. The mandibular fracture locations were classified as median, paramedian, angle, and condylar types. Statistical analysis for the relationship between prevalence of temporal bone fractures and mandibular fracture locations was performed using χ(2) test with Fisher's exact test. A P-value < 0.05 was considered statistically significant. The percentage of cases with temporal bone fracture was 3.0 % of all patients with mandibular fractures and 19.0 % of those with multiple mandibular fractures of paramedian and condylar type. There was a significant relationship between the incidence of temporal bone fracture and the paramedian- and condylar-type mandibular fracture (P = 0.001). Multiple mandibular fractures of paramedian and condylar type may be a stronger indicator for temporal bone fractures. This study suggests that patients with mandibular fracture, especially the paramedian and condylar type, should be examined for coexisting temporal bone fracture using MDCT.

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…

Quantifying the effect of disruptions to temporal coherence on the intelligibility of compressed American Sign Language video

NASA Astrophysics Data System (ADS)

Ciaramello, Frank M.; Hemami, Sheila S.

2009-02-01

Communication of American Sign Language (ASL) over mobile phones would be very beneficial to the Deaf community. ASL video encoded to achieve the rates provided by current cellular networks must be heavily compressed and appropriate assessment techniques are required to analyze the intelligibility of the compressed video. As an extension to a purely spatial measure of intelligibility, this paper quantifies the effect of temporal compression artifacts on sign language intelligibility. These artifacts can be the result of motion-compensation errors that distract the observer or frame rate reductions. They reduce the the perception of smooth motion and disrupt the temporal coherence of the video. Motion-compensation errors that affect temporal coherence are identified by measuring the block-level correlation between co-located macroblocks in adjacent frames. The impact of frame rate reductions was quantified through experimental testing. A subjective study was performed in which fluent ASL participants rated the intelligibility of sequences encoded at a range of 5 different frame rates and with 3 different levels of distortion. The subjective data is used to parameterize an objective intelligibility measure which is highly correlated with subjective ratings at multiple frame rates.

Spatio-temporal Analysis for New York State SPARCS Data

PubMed Central

Chen, Xin; Wang, Yu; Schoenfeld, Elinor; Saltz, Mary; Saltz, Joel; Wang, Fusheng

2017-01-01

Increased accessibility of health data provides unique opportunities to discover spatio-temporal patterns of diseases. For example, New York State SPARCS (Statewide Planning and Research Cooperative System) data collects patient level detail on patient demographics, diagnoses, services, and charges for each hospital inpatient stay and outpatient visit. Such data also provides home addresses for each patient. This paper presents our preliminary work on spatial, temporal, and spatial-temporal analysis of disease patterns for New York State using SPARCS data. We analyzed spatial distribution patterns of typical diseases at ZIP code level. We performed temporal analysis of common diseases based on 12 years’ historical data. We then compared the spatial variations for diseases with different levels of clustering tendency, and studied the evolution history of such spatial patterns. Case studies based on asthma demonstrated that the discovered spatial clusters are consistent with prior studies. We visualized our spatial-temporal patterns as animations through videos. PMID:28815148

Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices

NASA Astrophysics Data System (ADS)

Hyun, Seung; Kwon, Owoong; Lee, Bom-Yi; Seol, Daehee; Park, Beomjin; Lee, Jae Yong; Lee, Ju Hyun; Kim, Yunseok; Kim, Jin Kon

2016-01-01

Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process.Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07377d

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meeker, John D., E-mail: meekerj@umich.edu; Rossano, Mary G.; Protas, Bridget

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 withmore » 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.« less

Serum cytokine levels related to multiple dimensions of fatigue in patients with primary Sjögren's syndrome

PubMed Central

Hartkamp, A; Geenen, R; Bijl, M; Kruize, A; Godaert, G; Derksen, R

2004-01-01

Methods: Sixty female patients with pSS filled out a questionnaire to assess multiple dimensions of fatigue. Scores were compared with values in a population based control group (n = 139). Levels of interleukin (IL)1ß, IL2, IL6, IL10, and tumour necrosis factor α were measured in serum with commercial sandwich ELISAs. The relationship between self reported dimensions of fatigue and these serum cytokine levels was determined. Results: Patients with pSS had high scores at all dimensions of fatigue (p<0.001): general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue. Fatigue levels were not related to serum cytokine levels. The incidental finding that reduced motivation was higher in patients with detectable serum levels of IL10 (p = 0.04) disappeared after correction for multiple testing. Conclusion: Fatigue is prominent in patients with pSS and involves all dimensions of fatigue. The findings do not suggest a widespread effect of circulating cytokines on multiple aspects of fatigue. PMID:15361396

Comparison of Co-Temporal Modeling Algorithms on Sparse Experimental Time Series Data Sets.

PubMed

Allen, Edward E; Norris, James L; John, David J; Thomas, Stan J; Turkett, William H; Fetrow, Jacquelyn S

2010-01-01

Multiple approaches for reverse-engineering biological networks from time-series data have been proposed in the computational biology literature. These approaches can be classified by their underlying mathematical algorithms, such as Bayesian or algebraic techniques, as well as by their time paradigm, which includes next-state and co-temporal modeling. The types of biological relationships, such as parent-child or siblings, discovered by these algorithms are quite varied. It is important to understand the strengths and weaknesses of the various algorithms and time paradigms on actual experimental data. We assess how well the co-temporal implementations of three algorithms, continuous Bayesian, discrete Bayesian, and computational algebraic, can 1) identify two types of entity relationships, parent and sibling, between biological entities, 2) deal with experimental sparse time course data, and 3) handle experimental noise seen in replicate data sets. These algorithms are evaluated, using the shuffle index metric, for how well the resulting models match literature models in terms of siblings and parent relationships. Results indicate that all three co-temporal algorithms perform well, at a statistically significant level, at finding sibling relationships, but perform relatively poorly in finding parent relationships.

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.

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.

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…

Geostatistical interpolation model selection based on ArcGIS and spatio-temporal variability analysis of groundwater level in piedmont plains, northwest China.

PubMed

Xiao, Yong; Gu, Xiaomin; Yin, Shiyang; Shao, Jingli; Cui, Yali; Zhang, Qiulan; Niu, Yong

2016-01-01

Based on the geo-statistical theory and ArcGIS geo-statistical module, datas of 30 groundwater level observation wells were used to estimate the decline of groundwater level in Beijing piedmont. Seven different interpolation methods (inverse distance weighted interpolation, global polynomial interpolation, local polynomial interpolation, tension spline interpolation, ordinary Kriging interpolation, simple Kriging interpolation and universal Kriging interpolation) were used for interpolating groundwater level between 2001 and 2013. Cross-validation, absolute error and coefficient of determination (R(2)) was applied to evaluate the accuracy of different methods. The result shows that simple Kriging method gave the best fit. The analysis of spatial and temporal variability suggest that the nugget effects from 2001 to 2013 were increasing, which means the spatial correlation weakened gradually under the influence of human activities. The spatial variability in the middle areas of the alluvial-proluvial fan is relatively higher than area in top and bottom. Since the changes of the land use, groundwater level also has a temporal variation, the average decline rate of groundwater level between 2007 and 2013 increases compared with 2001-2006. Urban development and population growth cause over-exploitation of residential and industrial areas. The decline rate of the groundwater level in residential, industrial and river areas is relatively high, while the decreasing of farmland area and development of water-saving irrigation reduce the quantity of water using by agriculture and decline rate of groundwater level in agricultural area is not significant.

Short-Term Depression, Temporal Summation, and Onset Inhibition Shape Interval Tuning in Midbrain Neurons

PubMed Central

Baker, Christa A.

2014-01-01

A variety of synaptic mechanisms can contribute to single-neuron selectivity for temporal intervals in sensory stimuli. However, it remains unknown how these mechanisms interact to establish single-neuron sensitivity to temporal patterns of sensory stimulation in vivo. Here we address this question in a circuit that allows us to control the precise temporal patterns of synaptic input to interval-tuned neurons in behaviorally relevant ways. We obtained in vivo intracellular recordings under multiple levels of current clamp from midbrain neurons in the mormyrid weakly electric fish Brienomyrus brachyistius during stimulation with electrosensory pulse trains. To reveal the excitatory and inhibitory inputs onto interval-tuned neurons, we then estimated the synaptic conductances underlying responses. We found short-term depression in excitatory and inhibitory pathways onto all interval-tuned neurons. Short-interval selectivity was associated with excitation that depressed less than inhibition at short intervals, as well as temporally summating excitation. Long-interval selectivity was associated with long-lasting onset inhibition. We investigated tuning after separately nullifying the contributions of temporal summation and depression, and found the greatest diversity of interval selectivity among neurons when both mechanisms were at play. Furthermore, eliminating the effects of depression decreased sensitivity to directional changes in interval. These findings demonstrate that variation in depression and summation of excitation and inhibition helps to establish tuning to behaviorally relevant intervals in communication signals, and that depression contributes to neural coding of interval sequences. This work reveals for the first time how the interplay between short-term plasticity and temporal summation mediates the decoding of temporal sequences in awake, behaving animals. PMID:25339741

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

2018-03-01

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.

Multiple Levels of Suffering: Discrimination in Health-Care Settings is Associated With Enhanced Laboratory Pain Sensitivity in Sickle Cell Disease.

PubMed

Mathur, Vani A; Kiley, Kasey B; Haywood, Carlton; Bediako, Shawn M; Lanzkron, Sophie; Carroll, C Patrick; Buenaver, Luis F; Pejsa, Megan; Edwards, Robert R; Haythornthwaite, Jennifer A; Campbell, Claudia M

2016-12-01

People living with sickle cell disease (SCD) experience severe episodic and chronic pain and frequently report poor interpersonal treatment within health-care settings. In this particularly relevant context, we examined the relationship between perceived discrimination and both clinical and laboratory pain. Seventy-one individuals with SCD provided self-reports of experiences with discrimination in health-care settings and clinical pain severity, and completed a psychophysical pain testing battery in the laboratory. Discrimination in health-care settings was correlated with greater clinical pain severity and enhanced sensitivity to multiple laboratory-induced pain measures, as well as stress, depression, and sleep. After controlling for relevant covariates, discrimination remained a significant predictor of mechanical temporal summation (a marker of central pain facilitation), but not clinical pain severity or suprathreshold heat pain response. Furthermore, a significant interaction between experience with discrimination and clinical pain severity was associated with mechanical temporal summation; increased experience with discrimination was associated with an increased correlation between clinical pain severity and temporal summation of pain. Perceived discrimination within health-care settings was associated with pain facilitation. These findings suggest that discrimination may be related to increased central sensitization among SCD patients, and more broadly that health-care social environments may interact with pain pathophysiology.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spatio-temporal Hotelling observer for signal detection from image sequences

PubMed Central

Caucci, Luca; Barrett, Harrison H.; Rodríguez, Jeffrey J.

2010-01-01

Detection of signals in noisy images is necessary in many applications, including astronomy and medical imaging. The optimal linear observer for performing a detection task, called the Hotelling observer in the medical literature, can be regarded as a generalization of the familiar prewhitening matched filter. Performance on the detection task is limited by randomness in the image data, which stems from randomness in the object, randomness in the imaging system, and randomness in the detector outputs due to photon and readout noise, and the Hotelling observer accounts for all of these effects in an optimal way. If multiple temporal frames of images are acquired, the resulting data set is a spatio-temporal random process, and the Hotelling observer becomes a spatio-temporal linear operator. This paper discusses the theory of the spatio-temporal Hotelling observer and estimation of the required spatio-temporal covariance matrices. It also presents a parallel implementation of the observer on a cluster of Sony PLAYSTATION 3 gaming consoles. As an example, we consider the use of the spatio-temporal Hotelling observer for exoplanet detection. PMID:19550494

Spatio-temporal Hotelling observer for signal detection from image sequences.

PubMed

Caucci, Luca; Barrett, Harrison H; Rodriguez, Jeffrey J

2009-06-22

Detection of signals in noisy images is necessary in many applications, including astronomy and medical imaging. The optimal linear observer for performing a detection task, called the Hotelling observer in the medical literature, can be regarded as a generalization of the familiar prewhitening matched filter. Performance on the detection task is limited by randomness in the image data, which stems from randomness in the object, randomness in the imaging system, and randomness in the detector outputs due to photon and readout noise, and the Hotelling observer accounts for all of these effects in an optimal way. If multiple temporal frames of images are acquired, the resulting data set is a spatio-temporal random process, and the Hotelling observer becomes a spatio-temporal linear operator. This paper discusses the theory of the spatio-temporal Hotelling observer and estimation of the required spatio-temporal covariance matrices. It also presents a parallel implementation of the observer on a cluster of Sony PLAYSTATION 3 gaming consoles. As an example, we consider the use of the spatio-temporal Hotelling observer for exoplanet detection.

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

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...

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

PubMed Central

Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-01-01

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively. PMID:29596366

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing.

PubMed

Zhao, Hui; Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-03-29

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m³, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00-4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.

3D Printed Pediatric Temporal Bone: A Novel Training Model.

PubMed

Longfield, Evan A; Brickman, Todd M; Jeyakumar, Anita

2015-06-01

Temporal bone dissection is a fundamental element of otologic training. Cadaveric temporal bones (CTB) are the gold standard surgical training model; however, many institutions do not have ready access to them and their cost can be significant: $300 to $500. Furthermore, pediatric cadaveric temporal bones are not readily available. Our objective is to develop a pediatric temporal bone model. Temporal bone model. Tertiary Children's Hospital. Pediatric patient model. We describe the novel use of a 3D printer for the generation of a plaster training model from a pediatric high- resolution CT temporal bone scan of a normal pediatric temporal bone. Three models were produced and were evaluated. The models utilized multiple colors (white for bone, yellow for the facial nerve) and were of high quality. Two models were drilled as a proof of concept and found to be an acceptable facsimile of the patient's anatomy, rendering all necessary surgical landmarks accurately. The only negative comments pertaining to the 3D printed temporal bone as a training model were the lack of variation in hardness between cortical and cancellous bone, noting a tactile variation from cadaveric temporal bones. Our novel pediatric 3D temporal bone training model is a viable, low-cost training option for previously inaccessible pediatric temporal bone training. Our hope is that, as 3D printers become commonplace, these models could be rapidly reproduced, allowing for trainees to print models of patients before performing surgery on the living patient.

Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices.

PubMed

Hyun, Seung; Kwon, Owoong; Lee, Bom-Yi; Seol, Daehee; Park, Beomjin; Lee, Jae Yong; Lee, Ju Hyun; Kim, Yunseok; Kim, Jin Kon

2016-01-21

Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process.

Examining Procrastination Across Multiple Goal Stages: A Longitudinal Study of Temporal Motivation Theory

PubMed Central

Steel, Piers; Svartdal, Frode; Thundiyil, Tomas; Brothen, Thomas

2018-01-01

Procrastination is among the most common of motivational failures, putting off despite expecting to be worse off. We examine this dynamic phenomenon in a detailed and realistic longitudinal design (Study 1) as well as in a large correlational data set (N = 7400; Study 2). The results are largely consistent with temporal motivation theory. People’s pacing style reflects a hyperbolic curve, with the steepness of the curve predicted by self-reported procrastination. Procrastination is related to intention-action gaps, but not intentions. Procrastinators are susceptible to proximity of temptation and to the temporal separation between their intention and the planned act; the more distal, the greater the gap. Critical self-regulatory skills in explaining procrastination are attention control, energy regulation and automaticity, accounting for 74% of the variance. Future research using this design is recommended, as it provides an almost ideal blend of realism and detailed longitudinal assessment. PMID:29666590

Examining Procrastination Across Multiple Goal Stages: A Longitudinal Study of Temporal Motivation Theory.

PubMed

Steel, Piers; Svartdal, Frode; Thundiyil, Tomas; Brothen, Thomas

2018-01-01

Procrastination is among the most common of motivational failures, putting off despite expecting to be worse off. We examine this dynamic phenomenon in a detailed and realistic longitudinal design (Study 1) as well as in a large correlational data set ( N = 7400; Study 2). The results are largely consistent with temporal motivation theory. People's pacing style reflects a hyperbolic curve, with the steepness of the curve predicted by self-reported procrastination. Procrastination is related to intention-action gaps, but not intentions. Procrastinators are susceptible to proximity of temptation and to the temporal separation between their intention and the planned act; the more distal, the greater the gap. Critical self-regulatory skills in explaining procrastination are attention control, energy regulation and automaticity, accounting for 74% of the variance. Future research using this design is recommended, as it provides an almost ideal blend of realism and detailed longitudinal assessment.

VAUD: A Visual Analysis Approach for Exploring Spatio-Temporal Urban Data.

PubMed

Chen, Wei; Huang, Zhaosong; Wu, Feiran; Zhu, Minfeng; Guan, Huihua; Maciejewski, Ross

2017-10-02

Urban data is massive, heterogeneous, and spatio-temporal, posing a substantial challenge for visualization and analysis. In this paper, we design and implement a novel visual analytics approach, Visual Analyzer for Urban Data (VAUD), that supports the visualization, querying, and exploration of urban data. Our approach allows for cross-domain correlation from multiple data sources by leveraging spatial-temporal and social inter-connectedness features. Through our approach, the analyst is able to select, filter, aggregate across multiple data sources and extract information that would be hidden to a single data subset. To illustrate the effectiveness of our approach, we provide case studies on a real urban dataset that contains the cyber-, physical-, and socialinformation of 14 million citizens over 22 days.

Temporal variability of the bioaerosol background at a subway station: concentration level, size distribution, and diversity of airborne bacteria.

PubMed

Dybwad, Marius; Skogan, Gunnar; Blatny, Janet Martha

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 10(3) 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.

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

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

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.

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

PubMed

Kline, David; Andridge, Rebecca; Kaizar, Eloise

2017-06-01

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. Copyright © 2015 John Wiley & Sons, Ltd.

Spatio-temporal variation of fish taxonomic composition in a South-East Asian flood-pulse system.

PubMed

Kong, Heng; Chevalier, Mathieu; Laffaille, Pascal; Lek, Sovan

2017-01-01

The Tonle Sap Lake (TSL) is a flood-pulse system. It is the largest natural lake in South-East Asia and constitutes one of the largest fisheries over the world, supporting the livelihood of million peoples. Nonetheless, the Mekong River Basin is changing rapidly due to accelerating water infrastructure development (hydropower, irrigation, flood control, and water supply) and climate change, bringing considerable modifications to the annual flood-pulse of the TSL. Such modifications are expected to have strong impacts on fish biodiversity and abundance. This paper aims to characterize the spatio-temporal variations of fish taxonomic composition and to highlights the underlying determinants of these variations. For this purpose, we used data collected from a community catch monitoring program conducted at six sites during 141 weeks, covering two full hydrological cycles. For each week, we estimated beta diversity as the total variance of the site-by-species community matrix and partitioned it into Local Contribution to Beta Diversity (LCBD) and Species Contribution to Beta Diversity (SCBD). We then performed multiple linear regressions to determine whether species richness, species abundances and water level explained the temporal variation in the contribution of site and species to beta diversity. Our results indicate strong temporal variation of beta diversity due to differential contributions of sites and species to the spatial variation of fish taxonomic composition. We further found that the direction, the shape and the relative effect of species richness, abundances and water level on temporal variation in LCBD and SCBD values greatly varied among sites, thus suggesting spatial variation in the processes leading to temporal variation in community composition. Overall, our results suggest that fish taxonomic composition is not homogeneously distributed over space and time and is likely to be impacted in the future if the flood-pulse dynamic of the system is

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…

A spatio-temporal index for aerial full waveform laser scanning data

NASA Astrophysics Data System (ADS)

Laefer, Debra F.; Vo, Anh-Vu; Bertolotto, Michela

2018-04-01

Aerial laser scanning is increasingly available in the full waveform version of the raw signal, which can provide greater insight into and control over the data and, thus, richer information about the scanned scenes. However, when compared to conventional discrete point storage, preserving raw waveforms leads to vastly larger and more complex data volumes. To begin addressing these challenges, this paper introduces a novel bi-level approach for storing and indexing full waveform (FWF) laser scanning data in a relational database environment, while considering both the spatial and the temporal dimensions of that data. In the storage scheme's upper level, the full waveform datasets are partitioned into spatial and temporal coherent groups that are indexed by a two-dimensional R∗-tree. To further accelerate intra-block data retrieval, at the lower level a three-dimensional local octree is created for each pulse block. The local octrees are implemented in-memory and can be efficiently written to a database for reuse. The indexing solution enables scalable and efficient three-dimensional (3D) spatial and spatio-temporal queries on the actual pulse data - functionalities not available in other systems. The proposed FWF laser scanning data solution is capable of managing multiple FWF datasets derived from large flight missions. The flight structure is embedded into the data storage model and can be used for querying predicates. Such functionality is important to FWF data exploration since aircraft locations and orientations are frequently required for FWF data analyses. Empirical tests on real datasets of up to 1 billion pulses from Dublin, Ireland prove the almost perfect scalability of the system. The use of the local 3D octree in the indexing structure accelerated pulse clipping by 1.2-3.5 times for non-axis-aligned (NAA) polyhedron shaped clipping windows, while axis-aligned (AA) polyhedron clipping was better served using only the top indexing layer. The distinct

Satellite Level 3 & 4 Data Subsetting at NASA GES DISC

NASA Technical Reports Server (NTRS)

Huwe, Paul; Su, Jian; Loeser, Carlee; Ostrenga, Dana; Rui, Hualan; Vollmer, Bruce

2017-01-01

Earth Science data are available in many file formats (NetCDF, HDF, GRB, etc.) and in a wide range of sizes, from kilobytes to gigabytes. These properties have become a challenge to users if they are not familiar with these formats or only want a small region of interest (ROI) from a specific dataset. At NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), we have developed and implemented a multipurpose subset service to ease user access to Earth Science data. Our Level 3 & 4 Regridder is capable of subsetting across multiple parameters (spatially, temporally, by level, and by variable) as well as having additional beneficial features (temporal means, regridding to target grids, and file conversion to other data formats). In this presentation, we will demonstrate how users can use this service to better access only the data they need in the form they require.

Satellite Level 3 & 4 Data Subsetting at NASA GES DISC

NASA Astrophysics Data System (ADS)

Huwe, P.; Su, J.; Loeser, C. F.; Ostrenga, D.; Rui, H.; Vollmer, B.

2017-12-01

Earth Science data are available in many file formats (NetCDF, HDF, GRB, etc.) and in a wide range of sizes, from kilobytes to gigabytes. These properties have become a challenge to users if they are not familiar with these formats or only want a small region of interest (ROI) from a specific dataset. At NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), we have developed and implemented a multipurpose subset service to ease user access to Earth Science data. Our Level 3 & 4 Regridder is capable of subsetting across multiple parameters (spatially, temporally, by level, and by variable) as well as having additional beneficial features (temporal means, regridding to target grids, and file conversion to other data formats). In this presentation, we will demonstrate how users can use this service to better access only the data they need in the form they require.

Multiscale spatial and temporal estimation of the b-value

NASA Astrophysics Data System (ADS)

García-Hernández, R.; D'Auria, L.; Barrancos, J.; Padilla, G.

2017-12-01

The estimation of the spatial and temporal variations of the Gutenberg-Richter b-value is of great importance in different seismological applications. One of the problems affecting its estimation is the heterogeneous distribution of the seismicity which makes its estimate strongly dependent upon the selected spatial and/or temporal scale. This is especially important in volcanoes where dense clusters of earthquakes often overlap the background seismicity. Proposed solutions for estimating temporal variations of the b-value include considering equally spaced time intervals or variable intervals having an equal number of earthquakes. Similar approaches have been proposed to image the spatial variations of this parameter as well.We propose a novel multiscale approach, based on the method of Ogata and Katsura (1993), allowing a consistent estimation of the b-value regardless of the considered spatial and/or temporal scales. Our method, named MUST-B (MUltiscale Spatial and Temporal characterization of the B-value), basically consists in computing estimates of the b-value at multiple temporal and spatial scales, extracting for a give spatio-temporal point a statistical estimator of the value, as well as and indication of the characteristic spatio-temporal scale. This approach includes also a consistent estimation of the completeness magnitude (Mc) and of the uncertainties over both b and Mc.We applied this method to example datasets for volcanic (Tenerife, El Hierro) and tectonic areas (Central Italy) as well as an example application at global scale.

A common perceptual temporal limit of binding synchronous inputs across different sensory attributes and modalities.

PubMed

Fujisaki, Waka; Nishida, Shin'ya

2010-08-07

The human brain processes different aspects of the surrounding environment through multiple sensory modalities, and each modality can be subdivided into multiple attribute-specific channels. When the brain rebinds sensory content information ('what') across different channels, temporal coincidence ('when') along with spatial coincidence ('where') provides a critical clue. It however remains unknown whether neural mechanisms for binding synchronous attributes are specific to each attribute combination, or universal and central. In human psychophysical experiments, we examined how combinations of visual, auditory and tactile attributes affect the temporal frequency limit of synchrony-based binding. The results indicated that the upper limits of cross-attribute binding were lower than those of within-attribute binding, and surprisingly similar for any combination of visual, auditory and tactile attributes (2-3 Hz). They are unlikely to be the limits for judging synchrony, since the temporal limit of a cross-attribute synchrony judgement was higher and varied with the modality combination (4-9 Hz). These findings suggest that cross-attribute temporal binding is mediated by a slow central process that combines separately processed 'what' and 'when' properties of a single event. While the synchrony performance reflects temporal bottlenecks existing in 'when' processing, the binding performance reflects the central temporal limit of integrating 'when' and 'what' properties.

Evaluation of spatial and temporal patterns of insect damage and aflatoxin level in the pre-harvest corn fields to improve management tactics.

PubMed

Ni, Xinzhi; Wilson, Jeffrey P; Toews, Michael D; Buntin, G David; Lee, R Dewey; Li, Xin; Lei, Zhongren; He, Kanglai; Xu, Wenwei; Li, Xianchun; Huffaker, Alisa; Schmelz, Eric A

2014-10-01

Spatial and temporal patterns of insect damage in relation to aflatoxin contamination in a corn field with plants of uniform genetic background are not well understood. After previous examination of spatial patterns of insect damage and aflatoxin in pre-harvest corn fields, we further examined both spatial and temporal patterns of cob- and kernel-feeding insect damage, and aflatoxin level with two samplings at pre-harvest in 2008 and 2009. The feeding damage by each of the ear/kernel-feeding insects (i.e., corn earworm/fall armyworm damage on the silk/cob, and discoloration of corn kernels by stink bugs) and maize weevil population were assessed at each grid point with five ears. Sampling data showed a field edge effect in both insect damage and aflatoxin contamination in both years. Maize weevils tended toward an aggregated distribution more frequently than either corn earworm or stink bug damage in both years. The frequency of detecting aggregated distribution for aflatoxin level was less than any of the insect damage assessments. Stink bug damage and maize weevil number were more closely associated with aflatoxin level than was corn earworm damage. In addition, the indices of spatial-temporal association (χ) demonstrated that the number of maize weevils was associated between the first (4 weeks pre-harvest) and second (1 week pre-harvest) samplings in both years on all fields. In contrast, corn earworm damage between the first and second samplings from the field on the Belflower Farm, and aflatoxin level and corn earworm damage from the field on the Lang Farm were dissociated in 2009. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

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

Visual temporal processing in dyslexia and the magnocellular deficit theory: the need for speed?

PubMed

McLean, Gregor M T; Stuart, Geoffrey W; Coltheart, Veronika; Castles, Anne

2011-12-01

A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore temporal aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective Perceptual Speed factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability.

Plasma D-dimer levels and ischaemic lesions in multiple vascular regions can predict occult cancer in patients with cryptogenic stroke.

PubMed

Gon, Y; Sakaguchi, M; Takasugi, J; Kawano, T; Kanki, H; Watanabe, A; Oyama, N; Terasaki, Y; Sasaki, T; Mochizuki, H

2017-03-01

Cancer patients with cryptogenic stroke often have high plasma D-dimer levels and lesions in multiple vascular regions. Hence, if patients with cryptogenic stroke display such characteristics, occult cancer could be predicted. This study aimed to investigate the clinical characteristics of cryptogenic stroke as the first manifestation of occult cancer and to determine whether plasma D-dimer levels and lesions in multiple vascular regions can predict occult cancer in patients with cryptogenic stroke. Between January 2006 and October 2015, data on 1225 patients with acute ischaemic stroke were extracted from the stroke database of Osaka University Hospital. Among them, 184 patients were classified as having cryptogenic stroke, and 120 patients without a diagnosis of cancer at stroke onset were identified. Clinical variables were analyzed between cryptogenic stroke patients with and without occult cancer. Among 120 cryptogenic stroke patients without a diagnosis of cancer, 12 patients had occult cancer. The body mass index, hemoglobin levels and albumin levels were lower; plasma D-dimer and high-sensitivity C-reactive protein levels were higher; and lesions in multiple vascular regions were more common in patients with than in those without occult cancer. Multiple logistic regression analysis revealed that plasma D-dimer levels (odds ratio, 3.48; 95% confidence interval, 1.68-8.33; P = 0.002) and lesions in multiple vascular regions (odds ratio, 7.40; 95% confidence interval, 1.70-39.45; P = 0.01) independently predicted occult cancer. High plasma D-dimer levels and lesions in multiple vascular regions can be used to predict occult cancer in patients with cryptogenic stroke. © 2016 EAN.

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

Serum growth differentiation factor 15 levels in newly diagnosed multiple myeloma patients.

PubMed

Tarkun, Pinar; Birtas Atesoglu, Elif; Mehtap, Ozgur; Musul, Mahmut Mert; Hacihanefioglu, Abdullah

2014-01-01

Multiple myeloma (MM) is a hematological cancer associated with increased clonal malignant plasma cells. Growth differentiation factor 15 (GDF 15) is a protein that is highly expressed in the bone marrow mesenchymal stem cells of patients with MM. This study investigated whether the clinical stage of the disease, treatment response and survival are affected by pretreatment serum GDF 15 levels. Serum GDF 15 levels were measured in 35 newly diagnosed MM patients and 27 healthy controls. The correlation between serum GDF 15 levels and various clinical and laboratory parameters was analyzed. The study demonstrated significantly higher levels of GDF 15 in MM patients. There was a negative correlation between GDF 15 levels, hemoglobin and albumin levels, and a positive correlation between GDF 15 levels, CRP, creatinine, β-2-microglobulin and stage. GDF 15 levels were lower in patients who could receive autologous stem cell transplantation compared to other groups, representing a statistically significant difference. However, in the survival analyses, GDF 15 level did not have an impact on survival. High serum levels of GDF 15 may indicate a poor treatment response. Our study supports the prognostic value of GDF 15 in MM. © 2013 S. Karger AG, Basel.

Temporal change in fragmentation of continental US forests

Treesearch

James D. Wickham; Kurt H. Riitters; Timothy G. Wade; Collin Homer

2008-01-01

Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US....

Spatio-temporal models of mental processes from fMRI.

PubMed

Janoos, Firdaus; Machiraju, Raghu; Singh, Shantanu; Morocz, Istvan Ákos

2011-07-15

Understanding the highly complex, spatially distributed and temporally organized phenomena entailed by mental processes using functional MRI is an important research problem in cognitive and clinical neuroscience. Conventional analysis methods focus on the spatial dimension of the data discarding the information about brain function contained in the temporal dimension. This paper presents a fully spatio-temporal multivariate analysis method using a state-space model (SSM) for brain function that yields not only spatial maps of activity but also its temporal structure along with spatially varying estimates of the hemodynamic response. Efficient algorithms for estimating the parameters along with quantitative validations are given. A novel low-dimensional feature-space for representing the data, based on a formal definition of functional similarity, is derived. Quantitative validation of the model and the estimation algorithms is provided with a simulation study. Using a real fMRI study for mental arithmetic, the ability of this neurophysiologically inspired model to represent the spatio-temporal information corresponding to mental processes is demonstrated. Moreover, by comparing the models across multiple subjects, natural patterns in mental processes organized according to different mental abilities are revealed. Copyright © 2011 Elsevier Inc. All rights reserved.

Reconstruction of stochastic temporal networks through diffusive arrival times

NASA Astrophysics Data System (ADS)

Li, Xun; Li, Xiang

2017-06-01

Temporal networks have opened a new dimension in defining and quantification of complex interacting systems. Our ability to identify and reproduce time-resolved interaction patterns is, however, limited by the restricted access to empirical individual-level data. Here we propose an inverse modelling method based on first-arrival observations of the diffusion process taking place on temporal networks. We describe an efficient coordinate-ascent implementation for inferring stochastic temporal networks that builds in particular but not exclusively on the null model assumption of mutually independent interaction sequences at the dyadic level. The results of benchmark tests applied on both synthesized and empirical network data sets confirm the validity of our algorithm, showing the feasibility of statistically accurate inference of temporal networks only from moderate-sized samples of diffusion cascades. Our approach provides an effective and flexible scheme for the temporally augmented inverse problems of network reconstruction and has potential in a broad variety of applications.

Reconstruction of stochastic temporal networks through diffusive arrival times

PubMed Central

Li, Xun; Li, Xiang

2017-01-01

Temporal networks have opened a new dimension in defining and quantification of complex interacting systems. Our ability to identify and reproduce time-resolved interaction patterns is, however, limited by the restricted access to empirical individual-level data. Here we propose an inverse modelling method based on first-arrival observations of the diffusion process taking place on temporal networks. We describe an efficient coordinate-ascent implementation for inferring stochastic temporal networks that builds in particular but not exclusively on the null model assumption of mutually independent interaction sequences at the dyadic level. The results of benchmark tests applied on both synthesized and empirical network data sets confirm the validity of our algorithm, showing the feasibility of statistically accurate inference of temporal networks only from moderate-sized samples of diffusion cascades. Our approach provides an effective and flexible scheme for the temporally augmented inverse problems of network reconstruction and has potential in a broad variety of applications. PMID:28604687

Formally grounding spatio-temporal thinking.

PubMed

Klippel, Alexander; Wallgrün, Jan Oliver; Yang, Jinlong; Li, Rui; Dylla, Frank

2012-08-01

To navigate through daily life, humans use their ability to conceptualize spatio-temporal information, which ultimately leads to a system of categories. Likewise, the spatial sciences rely heavily on conceptualization and categorization as means to create knowledge when they process spatio-temporal data. In the spatial sciences and in related branches of artificial intelligence, an approach has been developed for processing spatio-temporal data on the level of coarse categories: qualitative spatio-temporal representation and reasoning (QSTR). Calculi developed in QSTR allow for the meaningful processing of and reasoning with spatio-temporal information. While qualitative calculi are widely acknowledged in the cognitive sciences, there is little behavioral assessment whether these calculi are indeed cognitively adequate. This is an astonishing conundrum given that these calculi are ubiquitous, are often intended to improve processes at the human-machine interface, and are on several occasions claimed to be cognitively adequate. We have systematically evaluated several approaches to formally characterize spatial relations from a cognitive-behavioral perspective for both static and dynamically changing spatial relations. This contribution will detail our framework, which is addressing the question how formal characterization of space can help us understand how people think with, in, and about space.

Patients with Alzheimer disease with multiple microbleeds: relation with cerebrospinal fluid biomarkers and cognition.

PubMed

Goos, Jeroen D C; Kester, M I; Barkhof, Frederik; Klein, Martin; Blankenstein, Marinus A; Scheltens, Philip; van der Flier, Wiesje M

2009-11-01

Microbleeds (MBs) are commonly observed in Alzheimer disease. A minority of patients has multiple MBs. We aimed to investigate associations of multiple MBs in Alzheimer disease with clinical and MRI characteristics and cerebrospinal fluid biomarkers. Patients with Alzheimer disease with multiple (>or=8) MBs on T2*-weighted MRI were matched for age, sex, and field strength with patients with Alzheimer disease without MBs on a 1:2 basis. We included 21 patients with multiple MBs (73+/-7 years, 33% female) and 42 patients without MBs (72+/-7 years, 38% female). Mini-Mental State Examination was used to assess dementia severity. Cognitive functions were assessed using neuropsychological tests. Medial temporal lobe atrophy (0 to 4), global cortical atrophy (0 to 3), and white matter hyperintensities (0 to 30) were assessed using visual rating scales. In a subset, apolipoprotein E genotype and cerebrospinal fluid amyloid beta 1-42, total tau and tau phosphorylated at threonine 181 were determined. Patients with multiple MBs performed worse on Mini-Mental State Examination (multiple MB: 17+/-7; no MB: 22+/-4, P<0.05) despite similar disease duration. Atrophy was not related to presence of MBs, but patients with multiple MBs had more white matter hyperintensities (multiple MB: 8.8+/-4.8; no MB: 3.2+/-3.6, P<0.05). Adjusted for age, sex, white matter hyperintensities, and medial temporal lobe atrophy, the multiple MB group additionally performed worse on Visual Association Test object naming and animal fluency. Patients with multiple MBs had lower cerebrospinal fluid amyloid beta 1-42 levels (307+/-61) than patients without MBs (505+/-201, P<0.05). Adjusted for the same covariates, total tau, and tau phosphorylated at threonine 181 were higher in the multiple MB group. Microbleeds are associated with the clinical manifestation and biochemical hallmarks of Alzheimer disease, suggesting possible involvement of MBs in the pathogenesis of Alzheimer disease.

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

PubMed

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

2014-05-01

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

Normalisation theory: Does it accurately describe temporal changes in adolescent drunkenness and smoking?

PubMed

Sznitman, Sharon R; Zlotnick, Cheryl; Harel-Fisch, Yossi

2016-07-01

The multiple risk model postulates that accumulating risk factors increase adolescent drunkenness and smoking. The normalisation theory adds to this by arguing that the relation between accumulative risk and drunkenness and smoking is dependent on the distribution of these behaviours in the larger population. More concretely, normalisation theory predicts that: (i) when population level use increases, low risk adolescents will be more likely to use alcohol and cigarettes; and (ii) adolescents facing multiple risk factors will be equally likely to use alcohol and cigarettes, regardless of trends in population level use. The current study empirically tests these assumptions on five waves of nationally representative samples of Israeli Jewish youth. Five cross-sectional waves of data from the Israeli Health Behaviour in School-aged Children survey for Jewish 10th graders were used. Logistic regression models measured the impact of changes in population level use across waves on drunkenness and smoking, and their association with differing levels of risk factors. Between zero and two risk factors, the risk of drunkenness and smoking increases for each additional risk factor. When reaching two risk factors, added risk does not significantly increase the likelihood of smoking and drunkenness. Changes in population level drunkenness and smoking did not systematically relate to changes in the individual level relationship between risk factors and smoking and drunkenness. The pattern of results in this study provides strong evidence for the multiple risk factor model and inconsistent evidence for the normalisation theory. [Sznitman SR, Zlotnick C, Harel-Fisch Y. Normalisation theory: Does it accurately describe temporal changes in adolescent drunkenness and smoking? Drug Alcohol Rev 2016;35:424-432]. © 2015 Australasian Professional Society on Alcohol and other Drugs.

A method for examining temporal changes in cyanobacterial ...

EPA Pesticide Factsheets

Cyanobacterial harmful algal blooms (CyanoHAB) are thought to be increasing globally over the past few decades, but relatively little quantitative information is available about the spatial extent of blooms. Satellite remote sensing provides a potential technology for identifying cyanoHABs in multiple water bodies and across geo-political boundaries. An assessment method was developed using MEdium Resolution Imaging Spectrometer (MERIS) imagery to quantify cyanoHAB surface area extent, transferable to different spatial areas, in Florida, Ohio, and California for the test period of 2008 to 2012. Temporal assessment was used to evaluate changes in satellite resolvable inland waterbodies for each state of interest. To further assess cyanoHAB risk within the states, the World Health Organization’s (WHO) recreational guidance level thresholds were used to categorize surface area of cyanoHABs into three risk categories: low, moderate, and high-risk bloom area. Results showed that in Florida, the area of cyanoHABs increased largely due to observed increases in high-risk bloom area. California exhibited a slight decrease in cyanoHAB extent, primarily attributed to decreases in Northern California. In Ohio (excluding Lake Erie), little change in cyanoHAB surface area was observed. This study uses satellite remote sensing to quantify changes in inland cyanoHAB surface area across numerous water bodies within an entire state. The temporal assessment method developed here

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…

Spatial and temporal variation in efficiency of the Moore egg collector

USGS Publications Warehouse

Worthington, Thomas A.; Brewer, Shannon K.; Farless, Nicole

2013-01-01

The Moore egg collector (MEC) was developed for quantitative and nondestructive capture of semibuoyant fish eggs. Previous studies have indicated that capture efficiency of the MEC was low and the use of one device did not adequately represent the spatial distribution within the water column of egg surrogates (gellan beads) of pelagic broadcast-spawning cyprinids. The objective of this study was to assess whether use of multiple MECs showed differences in spatial and temporal distribution of bead catches. Capture efficiency of three MECs was tested at four 500-m sites on the South Canadian River, a Great Plains river in Oklahoma. For each trial, approximately 100,000 beads were released and mean capture efficiency was 0.47–2.16%. Kolmogorov–Smirnov tests indicated the spatial distributions of bead catches were different among multiple MECs at three of four sites. Temporal variability in timing of peak catches of gellan beads was also evident between MECs. We concluded that the use of multiple MECs is necessary to properly sample eggs of pelagic broadcast-spawning cyprinids.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yi-Xin; Zeng, Qiang; Wang, Le

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 coefficientsmore » (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

Seasonal and temporal patterns of NDMA formation potentials in surface waters.

PubMed

Uzun, Habibullah; Kim, Daekyun; Karanfil, Tanju

2015-02-01

The seasonal and temporal patterns of N-nitrosodimethylamine (NDMA) formation potentials (FPs) were examined with water samples collected monthly for 21 month period in 12 surface waters. This long term study allowed monitoring the patterns of NDMA FPs under dynamic weather conditions (e.g., rainy and dry periods) covering several seasons. Anthropogenically impacted waters which were determined by high sucralose levels (>100 ng/L) had higher NDMA FPs than limited impacted sources (<100 ng/L). In most sources, NDMA FP showed more variability in spring months, while seasonal mean values remained relatively consistent. The study also showed that watershed characteristics played an important role in the seasonal and temporal patterns. In the two dam-controlled river systems (SW A and G), the NDMA FP levels at the downstream sampling locations were controlled by the NDMA levels in the dams independent of either the increases in discharge rates due to water releases from the dams prior to or during the heavy rain events or intermittent high NDMA FP levels observed at the upstream of dams. The large reservoirs and impoundments on rivers examined in this study appeared serving as an equalization basin for NDMA precursors. On the other hand, in a river without an upstream reservoir (SW E), the NDMA levels were influenced by the ratio of an upstream wastewater treatment plant (WWTP) effluent discharge to the river discharge rate. The impact of WWTP effluent decreased during the high river flow periods due to rain events. Linear regression with independent variables DOC, DON, and sucralose yielded poor correlations with NDMA FP (R(2) < 0.27). Multiple linear regression analysis using DOC and log [sucralose] yielded a better correlation with NDMA FP (R(2) = 0.53). Copyright © 2014 Elsevier Ltd. All rights reserved.

A spatio-temporal model for estimating the long-term effects of air pollution on respiratory hospital admissions in Greater London.

PubMed

Rushworth, Alastair; Lee, Duncan; Mitchell, Richard

2014-07-01

It has long been known that air pollution is harmful to human health, as many epidemiological studies have been conducted into its effects. Collectively, these studies have investigated both the acute and chronic effects of pollution, with the latter typically based on individual level cohort designs that can be expensive to implement. As a result of the increasing availability of small-area statistics, ecological spatio-temporal study designs are also being used, with which a key statistical problem is allowing for residual spatio-temporal autocorrelation that remains after the covariate effects have been removed. We present a new model for estimating the effects of air pollution on human health, which allows for residual spatio-temporal autocorrelation, and a study into the long-term effects of air pollution on human health in Greater London, England. The individual and joint effects of different pollutants are explored, via the use of single pollutant models and multiple pollutant indices. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A common perceptual temporal limit of binding synchronous inputs across different sensory attributes and modalities

PubMed Central

Fujisaki, Waka; Nishida, Shin'ya

2010-01-01

The human brain processes different aspects of the surrounding environment through multiple sensory modalities, and each modality can be subdivided into multiple attribute-specific channels. When the brain rebinds sensory content information (‘what’) across different channels, temporal coincidence (‘when’) along with spatial coincidence (‘where’) provides a critical clue. It however remains unknown whether neural mechanisms for binding synchronous attributes are specific to each attribute combination, or universal and central. In human psychophysical experiments, we examined how combinations of visual, auditory and tactile attributes affect the temporal frequency limit of synchrony-based binding. The results indicated that the upper limits of cross-attribute binding were lower than those of within-attribute binding, and surprisingly similar for any combination of visual, auditory and tactile attributes (2–3 Hz). They are unlikely to be the limits for judging synchrony, since the temporal limit of a cross-attribute synchrony judgement was higher and varied with the modality combination (4–9 Hz). These findings suggest that cross-attribute temporal binding is mediated by a slow central process that combines separately processed ‘what’ and ‘when’ properties of a single event. While the synchrony performance reflects temporal bottlenecks existing in ‘when’ processing, the binding performance reflects the central temporal limit of integrating ‘when’ and ‘what’ properties. PMID:20335212

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

PubMed

Parker, Wendy T; 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

2016-04-14

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

Spike-Based Bayesian-Hebbian Learning of Temporal Sequences

PubMed Central

Lindén, Henrik; Lansner, Anders

2016-01-01

Many cognitive and motor functions are enabled by the temporal representation and processing of stimuli, but it remains an open issue how neocortical microcircuits can reliably encode and replay such sequences of information. To better understand this, a modular attractor memory network is proposed in which meta-stable sequential attractor transitions are learned through changes to synaptic weights and intrinsic excitabilities via the spike-based Bayesian Confidence Propagation Neural Network (BCPNN) learning rule. We find that the formation of distributed memories, embodied by increased periods of firing in pools of excitatory neurons, together with asymmetrical associations between these distinct network states, can be acquired through plasticity. The model’s feasibility is demonstrated using simulations of adaptive exponential integrate-and-fire model neurons (AdEx). We show that the learning and speed of sequence replay depends on a confluence of biophysically relevant parameters including stimulus duration, level of background noise, ratio of synaptic currents, and strengths of short-term depression and adaptation. Moreover, sequence elements are shown to flexibly participate multiple times in the sequence, suggesting that spiking attractor networks of this type can support an efficient combinatorial code. The model provides a principled approach towards understanding how multiple interacting plasticity mechanisms can coordinate hetero-associative learning in unison. PMID:27213810

Treating autism by targeting the temporal lobes.

PubMed

Chi, Richard P; Snyder, Allan W

2014-11-01

Compelling new findings suggest that an early core signature of autism is a deficient left anterior temporal lobe response to language and an atypical over-activation of the right anterior temporal lobe. Intriguingly, our recent results from an entirely different line of reasoning and experiments also show that applying cathodal stimulation (suppressing) at the left anterior temporal lobe together with anodal stimulation (facilitating) at the right anterior temporal lobe, by transcranial direct current stimulation (tDCS), can induce some autistic-like cognitive abilities in otherwise normal adults. If we could briefly induce autistic like cognitive abilities in healthy individuals, it follows that we might be able to mitigate some autistic traits by reversing the above stimulation protocol, in an attempt to restore the typical dominance of the left anterior temporal lobe. Accordingly, we hypothesize that at least some autistic traits can be mitigated, by applying anodal stimulation (facilitating) at the left anterior temporal lobe together with cathodal stimulation (suppressing) at the right anterior temporal lobe. Our hypothesis is supported by strong convergent evidence that autistic symptoms can emerge and later reverse due to the onset and subsequent recovery of various temporal lobe (predominantly the left) pathologies. It is also consistent with evidence that the temporal lobes (especially the left) are a conceptual hub, critical for extracting meaning from lower level sensory information to form a coherent representation, and that a deficit in the temporal lobes underlies autistic traits. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

NONLINEAR OPTICAL EFFECTS AND FIBER OPTICS: Multiple stimulated optical echo in three-level media

NASA Astrophysics Data System (ADS)

Akhmediev, N. N.; Mel'nikov, I. V.

1988-12-01

It is shown that multiple stimulated optical echo may be generated in media with three closely spaced levels. The conditions for suppression of the stimulated echo signal are formulated and a proposal is described for apparatus which can be used to observe this effect.

Imaging systems level consolidation of novel associate memories: A longitudinal neuroimaging study

PubMed Central

Smith, Jason F; Alexander, Gene E; Chen, Kewei; Husain, Fatima T; Kim, Jieun; Pajor, Nathan; Horwitz, Barry

2010-01-01

Previously, a standard theory of systems level memory consolidation was developed to describe how memory recall becomes independent of the medial temporal memory system. More recently, an extended consolidation theory was proposed that predicts seven changes in regional neural activity and inter-regional functional connectivity. Using longitudinal event related functional magnetic resonance imaging of an associate memory task, we simultaneously tested all predictions and additionally tested for consolidation related changes in recall of associate memories at a sub-trial temporal resolution, analyzing cue, delay and target periods of each trial separately. Results consistent with the theoretical predictions were observed though two inconsistent results were also obtained. In particular, while recall-related delay period activity decreased with consolidation as predicted, visual cue activity increased for consolidated memories. Though the extended theory of memory consolidation is largely supported by our study, these results suggest the extended theory needs further refinement and the medial temporal memory system has multiple, temporally distinct roles in associate memory recall. Neuroimaging analysis at a sub-trial temporal resolution, as used here, may further clarify the role of the hippocampal complex in memory consolidation. PMID:19948227

Using spatio-temporal modeling to predict long-term exposure to black smoke at fine spatial and temporal scale

NASA Astrophysics Data System (ADS)

Dadvand, Payam; Rushton, Stephen; Diggle, Peter J.; Goffe, Louis; Rankin, Judith; Pless-Mulloli, Tanja

2011-01-01

Whilst exposure to air pollution is linked to a wide range of adverse health outcomes, assessing levels of this exposure has remained a challenge. This study reports a modeling approach for the estimation of weekly levels of ambient black smoke (BS) at residential postcodes across Northeast England (2055 km 2) over a 12 year period (1985-1996). A two-stage modeling strategy was developed using monitoring data on BS together with a range of covariates including data on traffic, population density, industrial activity, land cover (remote sensing), and meteorology. The first stage separates the temporal trend in BS for the region as a whole from within-region spatial variation and the second stage is a linear model which predicts BS levels at all locations in the region using spatially referenced covariate data as predictors and the regional predicted temporal trend as an offset. Traffic and land cover predictors were included in the final model, which predicted 70% of the spatio-temporal variation in BS across the study region over the study period. This modeling approach appears to provide a robust way of estimating exposure to BS at an inter-urban scale.

The Relationship between Multiplication Fact Speed-Recall and Fluency and Higher Level Mathematics Learning with Eighth Grade Middle School Students

ERIC Educational Resources Information Center

Curry, Steven James

2012-01-01

This quantitative study investigated relationships between higher level mathematics learning and multiplication fact fluency, multiplication fact speed-recall, and reading grade equivalency of eighth grade students in Algebra I and Pre-Algebra. Higher level mathematics learning was indicated by an average score of 80% or higher on first and second…

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.

Acute effects of single and multiple level thoracic manipulations on chronic mechanical neck pain: a randomized controlled trial

PubMed Central

Puntumetakul, Rungthip; Suvarnnato, Thavatchai; Werasirirat, Phurichaya; Uthaikhup, Sureeporn; Yamauchi, Junichiro; Boucaut, Rose

2015-01-01

Background Thoracic spine manipulation has become a popular alternative to local cervical manipulative therapy for mechanical neck pain. This study investigated the acute effects of single-level and multiple-level thoracic manipulations on chronic mechanical neck pain (CMNP). Methods Forty-eight patients with CMNP were randomly allocated to single-level thoracic manipulation (STM) at T6–T7 or multiple-level thoracic manipulation (MTM), or to a control group (prone lying). Cervical range of motion (CROM), visual analog scale (VAS), and the Thai version of the Neck Disability Index (NDI-TH) scores were measured at baseline, and at 24-hour and at 1-week follow-up. Results At 24-hour and 1-week follow-up, neck disability and pain levels were significantly (P<0.05) improved in the STM and MTM groups compared with the control group. CROM in flexion and left lateral flexion were increased significantly (P<0.05) in the STM group when compared with the control group at 1-week follow-up. The CROM in right rotation was increased significantly after MTM compared to the control group (P<0.05) at 24-hour follow-up. There were no statistically significant differences in neck disability, pain level at rest, and CROM between the STM and MTM groups. Conclusion These results suggest that both single-level and multiple-level thoracic manipulation improve neck disability, pain levels, and CROM at 24-hour and 1-week follow-up in patients with CMNP. PMID:25624764

Spatial and Temporal Variability in Biogenic Gas Accumulation and Release in The Greater Everglades at Multiple Scales of Measurement

NASA Astrophysics Data System (ADS)

McClellan, M. D.; Cornett, C.; Schaffer, L.; Comas, X.

2017-12-01

Wetlands play a critical role in the carbon (C) cycle by producing and releasing significant amounts of greenhouse biogenic gasses (CO2, CH4) into the atmosphere. Wetlands in tropical and subtropical climates (such as the Florida Everglades) have become of great interest in the past two decades as they account for more than 20% of the global peatland C stock and are located in climates that favor year-round C emissions. Despite the increase in research involving C emission from these types of wetlands, the spatial and temporal variability involving C production, accumulation and release is still highly uncertain, and is the focus of this research at multiple scales of measurement (i.e. lab, field and landscape). Spatial variability in biogenic gas content, build up and release, at both the lab and field scales, was estimated using a series of ground penetrating radar (GPR) surveys constrained with gas traps fitted with time-lapse cameras. Variability in gas content was estimated at the sub-meter scale (lab scale) within two extracted monoliths from different wetland ecosystems at the Disney wilderness Preserve (DWP) and the Blue Cypress Preserve (BCP) using high frequency GPR (1.2 GHz) transects across the monoliths. At the field scale (> 10m) changes in biogenic gas content were estimated using 160 MHz GPR surveys collected within 4 different emergent wetlands at the DWP. Additionally, biogenic gas content from the extracted monoliths was used to developed a landscape comparison of C accumulation and emissions for each different wetland ecosystem. Changes in gas content over time were estimated at the lab scale at high temporal resolution (i.e. sub-hourly) in monoliths from the BCP and Water Conservation Area 1-A. An autonomous rail system was constructed to estimate biogenic gas content variability within the wetland soil matrix using a series of continuous, uninterrupted 1.2 GHz GPR transects along the samples. Measurements were again constrained with an array

Temporal efficiency evaluation and small-worldness characterization in temporal networks

PubMed Central

Dai, Zhongxiang; Chen, Yu; Li, Junhua; Fam, Johnson; Bezerianos, Anastasios; Sun, Yu

2016-01-01

Numerous real-world systems can be modeled as networks. To date, most network studies have been conducted assuming stationary network characteristics. Many systems, however, undergo topological changes over time. Temporal networks, which incorporate time into conventional network models, are therefore more accurate representations of such dynamic systems. Here, we introduce a novel generalized analytical framework for temporal networks, which enables 1) robust evaluation of the efficiency of temporal information exchange using two new network metrics and 2) quantitative inspection of the temporal small-worldness. Specifically, we define new robust temporal network efficiency measures by incorporating the time dependency of temporal distance. We propose a temporal regular network model, and based on this plus the redefined temporal efficiency metrics and widely used temporal random network models, we introduce a quantitative approach for identifying temporal small-world architectures (featuring high temporal network efficiency both globally and locally). In addition, within this framework, we can uncover network-specific dynamic structures. Applications to brain networks, international trade networks, and social networks reveal prominent temporal small-world properties with distinct dynamic network structures. We believe that the framework can provide further insight into dynamic changes in the network topology of various real-world systems and significantly promote research on temporal networks. PMID:27682314

Temporal efficiency evaluation and small-worldness characterization in temporal networks

NASA Astrophysics Data System (ADS)

Dai, Zhongxiang; Chen, Yu; Li, Junhua; Fam, Johnson; Bezerianos, Anastasios; Sun, Yu

2016-09-01

Numerous real-world systems can be modeled as networks. To date, most network studies have been conducted assuming stationary network characteristics. Many systems, however, undergo topological changes over time. Temporal networks, which incorporate time into conventional network models, are therefore more accurate representations of such dynamic systems. Here, we introduce a novel generalized analytical framework for temporal networks, which enables 1) robust evaluation of the efficiency of temporal information exchange using two new network metrics and 2) quantitative inspection of the temporal small-worldness. Specifically, we define new robust temporal network efficiency measures by incorporating the time dependency of temporal distance. We propose a temporal regular network model, and based on this plus the redefined temporal efficiency metrics and widely used temporal random network models, we introduce a quantitative approach for identifying temporal small-world architectures (featuring high temporal network efficiency both globally and locally). In addition, within this framework, we can uncover network-specific dynamic structures. Applications to brain networks, international trade networks, and social networks reveal prominent temporal small-world properties with distinct dynamic network structures. We believe that the framework can provide further insight into dynamic changes in the network topology of various real-world systems and significantly promote research on temporal networks.

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

Group-level spatio-temporal pattern recovery in MEG decoding using multi-task joint feature learning.

PubMed

Kia, Seyed Mostafa; Pedregosa, Fabian; Blumenthal, Anna; Passerini, Andrea

2017-06-15

The use of machine learning models to discriminate between patterns of neural activity has become in recent years a standard analysis approach in neuroimaging studies. Whenever these models are linear, the estimated parameters can be visualized in the form of brain maps which can aid in understanding how brain activity in space and time underlies a cognitive function. However, the recovered brain maps often suffer from lack of interpretability, especially in group analysis of multi-subject data. To facilitate the application of brain decoding in group-level analysis, we present an application of multi-task joint feature learning for group-level multivariate pattern recovery in single-trial magnetoencephalography (MEG) decoding. The proposed method allows for recovering sparse yet consistent patterns across different subjects, and therefore enhances the interpretability of the decoding model. Our experimental results demonstrate that the mutli-task joint feature learning framework is capable of recovering more meaningful patterns of varying spatio-temporally distributed brain activity across individuals while still maintaining excellent generalization performance. We compare the performance of the multi-task joint feature learning in terms of generalization, reproducibility, and quality of pattern recovery against traditional single-subject and pooling approaches on both simulated and real MEG datasets. These results can facilitate the usage of brain decoding for the characterization of fine-level distinctive patterns in group-level inference. Considering the importance of group-level analysis, the proposed approach can provide a methodological shift towards more interpretable brain decoding models. Copyright © 2017 Elsevier B.V. All rights reserved.

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks.

PubMed

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O; Cohn, Emily; Mekaru, Sumiko R; Brownstein, John S; Ramakrishnan, Naren

2017-01-19

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations.

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks

PubMed Central

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O.; Cohn, Emily; Mekaru, Sumiko R.; Brownstein, John S.; Ramakrishnan, Naren

2017-01-01

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations. PMID:28102319

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks

NASA Astrophysics Data System (ADS)

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O.; Cohn, Emily; Mekaru, Sumiko R.; Brownstein, John S.; Ramakrishnan, Naren

2017-01-01

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations.

The relationship between national-level carbon dioxide emissions and population size: an assessment of regional and temporal variation, 1960-2005.

PubMed

Jorgenson, Andrew K; Clark, Brett

2013-01-01

This study examines the regional and temporal differences in the statistical relationship between national-level carbon dioxide emissions and national-level population size. The authors analyze panel data from 1960 to 2005 for a diverse sample of nations, and employ descriptive statistics and rigorous panel regression modeling techniques. Initial descriptive analyses indicate that all regions experienced overall increases in carbon emissions and population size during the 45-year period of investigation, but with notable differences. For carbon emissions, the sample of countries in Asia experienced the largest percent increase, followed by countries in Latin America, Africa, and lastly the sample of relatively affluent countries in Europe, North America, and Oceania combined. For population size, the sample of countries in Africa experienced the largest percent increase, followed countries in Latin America, Asia, and the combined sample of countries in Europe, North America, and Oceania. Findings for two-way fixed effects panel regression elasticity models of national-level carbon emissions indicate that the estimated elasticity coefficient for population size is much smaller for nations in Africa than for nations in other regions of the world. Regarding potential temporal changes, from 1960 to 2005 the estimated elasticity coefficient for population size decreased by 25% for the sample of Africa countries, 14% for the sample of Asia countries, 6.5% for the sample of Latin America countries, but remained the same in size for the sample of countries in Europe, North America, and Oceania. Overall, while population size continues to be the primary driver of total national-level anthropogenic carbon dioxide emissions, the findings for this study highlight the need for future research and policies to recognize that the actual impacts of population size on national-level carbon emissions differ across both time and region.

Community ecology in 3D: Tensor decomposition reveals spatio-temporal dynamics of large ecological communities

PubMed Central

Lindegren, Martin; Denker, Tim Spaanheden; Floeter, Jens; Fock, Heino O.; Sguotti, Camilla; Stäbler, Moritz; Otto, Saskia A.; Möllmann, Christian

2017-01-01

Understanding spatio-temporal dynamics of biotic communities containing large numbers of species is crucial to guide ecosystem management and conservation efforts. However, traditional approaches usually focus on studying community dynamics either in space or in time, often failing to fully account for interlinked spatio-temporal changes. In this study, we demonstrate and promote the use of tensor decomposition for disentangling spatio-temporal community dynamics in long-term monitoring data. Tensor decomposition builds on traditional multivariate statistics (e.g. Principal Component Analysis) but extends it to multiple dimensions. This extension allows for the synchronized study of multiple ecological variables measured repeatedly in time and space. We applied this comprehensive approach to explore the spatio-temporal dynamics of 65 demersal fish species in the North Sea, a marine ecosystem strongly altered by human activities and climate change. Our case study demonstrates how tensor decomposition can successfully (i) characterize the main spatio-temporal patterns and trends in species abundances, (ii) identify sub-communities of species that share similar spatial distribution and temporal dynamics, and (iii) reveal external drivers of change. Our results revealed a strong spatial structure in fish assemblages persistent over time and linked to differences in depth, primary production and seasonality. Furthermore, we simultaneously characterized important temporal distribution changes related to the low frequency temperature variability inherent in the Atlantic Multidecadal Oscillation. Finally, we identified six major sub-communities composed of species sharing similar spatial distribution patterns and temporal dynamics. Our case study demonstrates the application and benefits of using tensor decomposition for studying complex community data sets usually derived from large-scale monitoring programs. PMID:29136658

Community ecology in 3D: Tensor decomposition reveals spatio-temporal dynamics of large ecological communities.

PubMed

Frelat, Romain; Lindegren, Martin; Denker, Tim Spaanheden; Floeter, Jens; Fock, Heino O; Sguotti, Camilla; Stäbler, Moritz; Otto, Saskia A; Möllmann, Christian

2017-01-01

Understanding spatio-temporal dynamics of biotic communities containing large numbers of species is crucial to guide ecosystem management and conservation efforts. However, traditional approaches usually focus on studying community dynamics either in space or in time, often failing to fully account for interlinked spatio-temporal changes. In this study, we demonstrate and promote the use of tensor decomposition for disentangling spatio-temporal community dynamics in long-term monitoring data. Tensor decomposition builds on traditional multivariate statistics (e.g. Principal Component Analysis) but extends it to multiple dimensions. This extension allows for the synchronized study of multiple ecological variables measured repeatedly in time and space. We applied this comprehensive approach to explore the spatio-temporal dynamics of 65 demersal fish species in the North Sea, a marine ecosystem strongly altered by human activities and climate change. Our case study demonstrates how tensor decomposition can successfully (i) characterize the main spatio-temporal patterns and trends in species abundances, (ii) identify sub-communities of species that share similar spatial distribution and temporal dynamics, and (iii) reveal external drivers of change. Our results revealed a strong spatial structure in fish assemblages persistent over time and linked to differences in depth, primary production and seasonality. Furthermore, we simultaneously characterized important temporal distribution changes related to the low frequency temperature variability inherent in the Atlantic Multidecadal Oscillation. Finally, we identified six major sub-communities composed of species sharing similar spatial distribution patterns and temporal dynamics. Our case study demonstrates the application and benefits of using tensor decomposition for studying complex community data sets usually derived from large-scale monitoring programs.

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

PubMed Central

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

2008-01-01

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. PMID:19011082

Latent Variable Regression 4-Level Hierarchical Model Using Multisite Multiple-Cohorts Longitudinal Data. CRESST Report 801

ERIC Educational Resources Information Center

Choi, Kilchan

2011-01-01

This report explores a new latent variable regression 4-level hierarchical model for monitoring school performance over time using multisite multiple-cohorts longitudinal data. This kind of data set has a 4-level hierarchical structure: time-series observation nested within students who are nested within different cohorts of students. These…

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.

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.

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.

[Correlation of Th17 Cells and IL-17 Level in Multiple Myeloma Patients with Pathogenesis of Multiple Myeloma].

PubMed

DU, Chao-Yang; Yang, Ru-Yu; Li, Chao; Duan, Li-Juan

2017-02-01

To explore the correlation of Th17 cell rate and IL-17 level with pathogenetis of multiple myeloma(MM). Forty-five cases of MM were enrolled in MM group, while 45 healthy volunteers were selected in control group. The rate of Th17 cells, levels of IL-17 and β2-microglobulin(β2-MG) in patients subgrouping according to ISS staging and treatment were detected by using flow cytometer and IL-17 assay kit. The correlation of Th17 cell rate and IL-17 level with MM was analyzed. The rate of Th17 cells and level of IL-17 in MM group were higher than those in control group(P<0.05), the rate of Th17 cells and level of IL-17 in ISS III stage patients were higher than those in ISS I and II stage patients(P<0.05); the rate of Th17 cells and level of IL-17 in ISS I and ISS II stage patients were not significant difference (P>0.05); the rate of Th17 cells and level of IL-17 in firstly treated, retreated/refractory patients were significantly higher than those in patients with effective treatment(P<0.05), while the rate of Th17 cells and level of IL-17 between firstly treated patients and retreated/refractory patients were not significant difference (P>0.05). The Th17 rate and IL-17 level in MM patients positively correlated with β2-MG level (r=0.422, r=0.416, P<0.05). The obvious increase of Th17 rate, IL-17 and β2-MG levels closely relates with pathogenesis of MM. The Th17 rate and IL-17 level may be used as important evidence for evaluation of ISS stage and therapeutic efficacy of MM.

Altered Medial Frontal and Superior Temporal Response to Implicit Processing of Emotions in Autism.

PubMed

Kana, Rajesh K; Patriquin, Michelle A; Black, Briley S; Channell, Marie M; Wicker, Bruno

2016-01-01

Interpreting emotional expressions appropriately poses a challenge for individuals with autism spectrum disorder (ASD). In particular, difficulties with emotional processing in ASD are more pronounced in contexts where emotional expressions are subtle, automatic, and reflexive-that is, implicit. In contrast, explicit emotional processing, which requires the cognitive evaluation of an emotional experience, appears to be relatively intact in individuals with ASD. In the present study, we examined the brain activation and functional connectivity differences underlying explicit and implicit emotional processing in age- and IQ-matched adults with (n = 17) and without (n = 15) ASD. Results indicated: (1) significantly reduced levels of brain activation in participants with ASD in medial prefrontal cortex (MPFC) and superior temporal gyrus (STG) during implicit emotion processing; (2) significantly weaker functional connectivity in the ASD group in connections of the MPFC with the amygdala, temporal lobe, parietal lobe, and fusiform gyrus; (3) No group difference in performance accuracy or reaction time; and (4) Significant positive relationship between empathizing ability and STG activity in ASD but not in typically developing participants. These findings suggest that the neural mechanisms underlying implicit, but not explicit, emotion processing may be altered at multiple levels in individuals with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Supporting Children in Mastering Temporal Relations of Stories: The TERENCE Learning Approach

ERIC Educational Resources Information Center

Di Mascio, Tania; Gennari, Rosella; Melonio, Alessandra; Tarantino, Laura

2016-01-01

Though temporal reasoning is a key factor for text comprehension, existing proposals for visualizing temporal information and temporal connectives proves to be inadequate for children, not only for their levels of abstraction and detail, but also because they rely on pre-existing mental models of time and temporal connectives, while in the case of…

Future Directions in Vulnerability to Depression among Youth: Integrating Risk Factors and Processes across Multiple Levels of Analysis

PubMed Central

Hankin, Benjamin L.

2014-01-01

Depression is a developmental phenomenon. Considerable progress has been made in describing the syndrome, establishing its prevalence and features, providing clues as to its etiology, and developing evidence-based treatment and prevention options. Despite considerable headway in distinct lines of vulnerability research, there is an explanatory gap in the field ability to more comprehensively explain and predict who is likely to become depressed, when, and why. Still, despite clear success in predicting moderate variance for future depression, especially with empirically rigorous methods and designs, the heterogeneous and multi-determined nature of depression suggests that additional etiologies need to be included to advance knowledge on developmental pathways to depression. This paper advocates for a multiple levels of analysis approach to investigating vulnerability to depression across the lifespan and providing a more comprehensive understanding of its etiology. One example of a multiple levels of analysis model of vulnerabilities to depression is provided that integrates the most accessible, observable factors (e.g., cognitive and temperament risks), intermediate processes and endophenotypes (e.g., information processing biases, biological stress physiology, and neural activation and connectivity), and genetic influences (e.g., candidate genes and epigenetics). Evidence for each of these factors as well as their cross-level integration is provided. Methodological and conceptual considerations important for conducting integrative, multiple levels of depression vulnerability research are discussed. Finally, translational implications for how a multiple levels of analysis perspective may confer additional leverage to reduce the global burden of depression and improve care are considered. PMID:22900513

Cortical Circuit for Binding Object Identity and Location During Multiple-Object Tracking

PubMed Central

Nummenmaa, Lauri; Oksama, Lauri; Glerean, Erico; Hyönä, Jukka

2017-01-01

Abstract Sustained multifocal attention for moving targets requires binding object identities with their locations. The brain mechanisms of identity-location binding during attentive tracking have remained unresolved. In 2 functional magnetic resonance imaging experiments, we measured participants’ hemodynamic activity during attentive tracking of multiple objects with equivalent (multiple-object tracking) versus distinct (multiple identity tracking, MIT) identities. Task load was manipulated parametrically. Both tasks activated large frontoparietal circuits. MIT led to significantly increased activity in frontoparietal and temporal systems subserving object recognition and working memory. These effects were replicated when eye movements were prohibited. MIT was associated with significantly increased functional connectivity between lateral temporal and frontal and parietal regions. We propose that coordinated activity of this network subserves identity-location binding during attentive tracking. PMID:27913430

The proximal-to-distal sequence in upper-limb motions on multiple levels and time scales.

PubMed

Serrien, Ben; Baeyens, Jean-Pierre

2017-10-01

The proximal-to-distal sequence is a phenomenon that can be observed in a large variety of motions of the upper limbs in both humans and other mammals. The mechanisms behind this sequence are not completely understood and motor control theories able to explain this phenomenon are currently incomplete. The aim of this narrative review is to take a theoretical constraints-led approach to the proximal-to-distal sequence and provide a broad multidisciplinary overview of relevant literature. This sequence exists at multiple levels (brain, spine, muscles, kinetics and kinematics) and on multiple time scales (motion, motor learning and development, growth and possibly even evolution). We hypothesize that the proximodistal spatiotemporal direction on each time scale and level provides part of the organismic constraints that guide the dynamics at the other levels and time scales. The constraint-led approach in this review may serve as a first onset towards integration of evidence and a framework for further experimentation to reveal the dynamics of the proximal-to-distal sequence. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Population responses in primary auditory cortex simultaneously represent the temporal envelope and periodicity features in natural speech.

PubMed

Abrams, Daniel A; Nicol, Trent; White-Schwoch, Travis; Zecker, Steven; Kraus, Nina

2017-05-01

Speech perception relies on a listener's ability to simultaneously resolve multiple temporal features in the speech signal. Little is known regarding neural mechanisms that enable the simultaneous coding of concurrent temporal features in speech. Here we show that two categories of temporal features in speech, the low-frequency speech envelope and periodicity cues, are processed by distinct neural mechanisms within the same population of cortical neurons. We measured population activity in primary auditory cortex of anesthetized guinea pig in response to three variants of a naturally produced sentence. Results show that the envelope of population responses closely tracks the speech envelope, and this cortical activity more closely reflects wider bandwidths of the speech envelope compared to narrow bands. Additionally, neuronal populations represent the fundamental frequency of speech robustly with phase-locked responses. Importantly, these two temporal features of speech are simultaneously observed within neuronal ensembles in auditory cortex in response to clear, conversation, and compressed speech exemplars. Results show that auditory cortical neurons are adept at simultaneously resolving multiple temporal features in extended speech sentences using discrete coding mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

When should temporal-lobe epilepsy be treated surgically?

PubMed

Spencer, Susan S

2002-10-01

Our current knowledge of mesial-temporal-lobe epilepsy (MTLE) is extensive, yet still insufficient to draw final conclusions on the optimal approach to its therapy. MTLE has been well characterised and can usually be identified with noninvasive studies including scalp electroencephalography (EEG) and video monitoring with ictal recording, magnetic resonance imaging, single-photon-emission computed tomography, positron emission tomography, neuropsychological assessment, and historical and clinical data. Sometimes, invasive EEG is needed to confirm mesial-temporal-lobe seizure onset, which, combined with the underlying pathological abnormality (the substrate) of mesial temporal sclerosis (hippocampal neuronal loss and gliosis), defines MTLE. This disorder is the most common refractory partial epilepsy, and also the one most often treated surgically, because medical treatment fails in 75% of cases, and surgical treatment succeeds in a similar percentage. Despite the recent publication of the first randomised trial of surgical treatment for MTLE, questions remain about the neurological consequences of both medical and surgical treatment, the ultimate gains in quality of life parameters, and the precise predictors of success. Long-term follow-up and analyses of multiple factors in large groups of contemporary patient populations will be necessary to fully answer the question, "is temporal lobe epilepsy a surgical disease?" Right now it should be considered one in most cases.

Pitting temporal against spatial integration in schizophrenic patients.

PubMed

Herzog, Michael H; Brand, Andreas

2009-06-30

Schizophrenic patients show strong impairments in visual backward masking possibly caused by deficits on the early stages of visual processing. The underlying aberrant mechanisms are not clearly understood. Spatial as well as temporal processing deficits have been proposed. Here, by combining a spatial with a temporal integration paradigm, we show further evidence that temporal but not spatial processing is impaired in schizophrenic patients. Eleven schizophrenic patients and ten healthy controls were presented with sequences composed of Vernier stimuli. Patients needed significantly longer presentation times for sequentially presented Vernier stimuli to reach a performance level comparable to that of healthy controls (temporal integration deficit). When we added spatial contextual elements to some of the Vernier stimuli, performance changed in a complex but comparable manner in patients and controls (intact spatial integration). Hence, temporal but not spatial processing seems to be deficient in schizophrenia.

High levels of 15-oxygenated steroids in circulation of patients with multiple sclerosis: fact or fiction?

PubMed

Björkhem, I; Lövgren-Sandblom, A; Piehl, F; Khademi, M; Pettersson, H; Leoni, V; Olsson, T; Diczfalusy, U

2011-01-01

15-Oxygenated cholesterol species such as 5α-cholest-8(14)ene-3β,15α-diol (15HC) and 3β-hydroxy-5α-cholest-8(14)-en-15-one (15KC) are commercially available synthetic products unlikely to occur in biological systems. Surprisingly, Farez et al. recently reported that these two steroids occur in human circulation at levels considerably higher than those of any other endogenous oxysterol [Farez, M. et al. 2009. Toll-like receptor 2 and poly(ADP-ribose) polymerase 1 promote central nervous system neuroinflammation in progressive EAE. Nat. Immunol. 10: 958-964]. The levels were reported to be increased in patients with multiple sclerosis in a progressive phase and the authors suggested that this could be utilized diagnostically. Based on extensive in vitro experiments exposing cells to the same high levels of 15HC as found in vivo (1000 ng/ml) the authors concluded that 15HC may be an important pathogenetic factor in multiple sclerosis. Using combined gas chromatography-mass spectrometry we fail to detect significant plasma levels of 15HC either in healthy controls or in patients with multiple sclerosis (levels < 2 ng/ml). If 15KC is present in these plasma samples, the concentration of it must be <10 ng/ml. Our failure to detect significant levels of the above steroids could not be due to loss during hydrolysis and work-up because recovery of the added two oxysterols was close to 100%. Autoxidation of lipoprotein-bound cholesterol resulted in extensive conversion of cholesterol into 7-oxygenated but not 15-oxygenated sterols. We conclude that if present there are trace amounts only of the above 15-oxygenated steroids in human circulation and that the role of such oxysterols as pathogenetic factors and biomarkers must be reconsidered.

Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle.

PubMed

Ferrari, Renata; Marzinelli, Ezequiel M; Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F; Byrne, Maria; Malcolm, Hamish A; Williams, Stefan B; Steinberg, Peter D

2018-01-01

Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate 'no-take' and 'general-use' (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5-10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical analyses and

Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle

PubMed Central

Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F.; Byrne, Maria; Malcolm, Hamish A.; Williams, Stefan B.; Steinberg, Peter D.

2018-01-01

Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate ‘no-take’ and ‘general-use’ (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5–10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical

Circulating IGF-1, IGFB-3, GH and TSH levels in multiple sclerosis and their relationship with treatment.

PubMed

Akcali, Aylin; Bal, Berrin; Erbagci, Binnur

2017-07-01

Improving the proficiency of oligodendrocytes in their ability to repair myelin damage is one of the major goals of multiple sclerosis treatment. Insulin-like growth factor-1 (IGF-1) is one of several polypeptides that are considered to have potential benefits in that sense. In the present study, we aimed to determine serum levels of IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3), thyroid stimulating hormone (TSH) and growth hormone (GH) among treated and non-treated patients with Relapsing-Remitting Multiple Sclerosis (RRMS) and a healthy control group. The study enrolled 100 RRMS patients and 100 age- and sex-matched control subjects diagnosed with definite multiple sclerosis (MS). Serum GH, IGF-1, IGFBP-3, and TSH levels were studied. The number of relapses and Expanded Disability Status Scale were negatively correlated and IGFBP-3 and GH were positively correlated with IGF-1. A statistically significant difference was not observed when patients were divided into two subgroups as patients treated with a MS-specific therapy (n = 54) and non-treated patients (n = 46). TSH and IGFBP-3 values were significantly lower in patient group vs. While no difference was determined with in IGF-1 levels, low levels of IGF-1 was in correlation with the least levels of IGFBP-3. To understand the relation between IGF-1 and IGFBP-3, the role of low levels of IGFBP-3 and TSH may be studied with clinic isolated syndrome patients and the evolution of these patients to definite MS.

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.

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

Temporal Non-locality

NASA Astrophysics Data System (ADS)

Filk, Thomas

2013-04-01

In this article I investigate several possibilities to define the concept of "temporal non-locality" within the standard framework of quantum theory. In particular, I analyze the notions of "temporally non-local states", "temporally non-local events" and "temporally non-local observables". The idea of temporally non-local events is already inherent in the standard formalism of quantum mechanics, and Basil Hiley recently defined an operator in order to measure the degree of such a temporal non-locality. The concept of temporally non-local states enters as soon as "clock-representing states" are introduced in the context of special and general relativity. It is discussed in which way temporally non-local measurements may find an interesting application for experiments which test temporal versions of Bell inequalities.

Regional and Temporal Variation in Methamphetamine-Related Incidents: Applications of Spatial and Temporal Scan Statistics

PubMed Central

Sudakin, Daniel L.

2009-01-01

Introduction This investigation utilized spatial scan statistics, geographic information systems and multiple data sources to assess spatial clustering of statewide methamphetamine-related incidents. Temporal and spatial associations with regulatory interventions to reduce access to precursor chemicals (pseudoephedrine) were also explored. Methods Four statewide data sources were utilized including regional poison control center statistics, fatality incidents, methamphetamine laboratory seizures, and hazardous substance releases involving methamphetamine laboratories. Spatial clustering of methamphetamine incidents was assessed using SaTScan™. SaTScan™ was also utilized to assess space-time clustering of methamphetamine laboratory incidents, in relation to the enactment of regulations to reduce access to pseudoephedrine. Results Five counties with a significantly higher relative risk of methamphetamine-related incidents were identified. The county identified as the most likely cluster had a significantly elevated relative risk of methamphetamine laboratories (RR=11.5), hazardous substance releases (RR=8.3), and fatalities relating to methamphetamine (RR=1.4). A significant increase in relative risk of methamphetamine laboratory incidents was apparent in this same geographic area (RR=20.7) during the time period when regulations were enacted in 2004 and 2005, restricting access to pseudoephedrine. Subsequent to the enactment of these regulations, a significantly lower rate of incidents (RR 0.111, p=0.0001) was observed over a large geographic area of the state, including regions that previously had significantly higher rates. Conclusions Spatial and temporal scan statistics can be effectively applied to multiple data sources to assess regional variation in methamphetamine-related incidents, and explore the impact of preventive regulatory interventions. PMID:19225949

Two-color temporal focusing multiphoton excitation imaging with tunable-wavelength excitation

NASA Astrophysics Data System (ADS)

Lien, Chi-Hsiang; Abrigo, Gerald; Chen, Pei-Hsuan; Chien, Fan-Ching

2017-02-01

Wavelength tunable temporal focusing multiphoton excitation microscopy (TFMPEM) is conducted to visualize optical sectioning images of multiple fluorophore-labeled specimens through the optimal two-photon excitation (TPE) of each type of fluorophore. The tunable range of excitation wavelength was determined by the groove density of the grating, the diffraction angle, the focal length of lenses, and the shifting distance of the first lens in the beam expander. Based on a consideration of the trade-off between the tunable-wavelength range and axial resolution of temporal focusing multiphoton excitation imaging, the presented system demonstrated a tunable-wavelength range from 770 to 920 nm using a diffraction grating with groove density of 830 lines/mm. TPE fluorescence imaging examination of a fluorescent thin film indicated that the width of the axial confined excitation was 3.0±0.7 μm and the shifting distance of the temporal focal plane was less than 0.95 μm within the presented wavelength tunable range. Fast different wavelength excitation and three-dimensionally rendered imaging of Hela cell mitochondria and cytoskeletons and mouse muscle fibers were demonstrated. Significantly, the proposed system can improve the quality of two-color TFMPEM images through different excitation wavelengths to obtain higher-quality fluorescent signals in multiple-fluorophore measurements.

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.

Expression of SHANK3 in the Temporal Neocortex of Patients with Intractable Temporal Epilepsy and Epilepsy Rat Models.

PubMed

Zhang, Yanke; Gao, Baobing; Xiong, Yan; Zheng, Fangshuo; Xu, Xin; Yang, Yong; Hu, Yida; Wang, Xuefeng

2017-07-01

SH3 and multiple ankyrin (ANK) repeat domain 3 (SHANK3) is a synaptic scaffolding protein enriched in the postsynaptic density of excitatory synapses. SHANK3 plays an important role in the formation and maturation of excitatory synapses. In the brain, SHANK3 directly or indirectly interacts with various synaptic molecules including N-methyl-D-aspartate receptor, the metabotropic glutamate receptor (mGluR), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. Previous studies have shown that Autism spectrum disorder is a result of mutations of the main SHANK3 isoforms, which may be due to deficit in excitatory synaptic transmission and plasticity. Recently, accumulating evidence has demonstrated that overexpression of SHANK3 could induce seizures in vivo. However, little is known about the role of SHANK3 in refractory temporal lobe epilepsy (TLE). Therefore, we investigated the expression pattern of SHANK3 in patients with intractable temporal lobe epilepsy and in pilocarpine-induced models of epilepsy. Immunofluorescence, immunohistochemistry, and western blot analysis were used to locate and determine the expression of SHANK3 in the temporal neocortex of patients with epilepsy, and in the hippocampus and temporal lobe cortex of rats in a pilocarpine-induced epilepsy model. Double-labeled immunofluorescence showed that SHANK3 was mainly expressed in neurons. Western blot analysis confirmed that SHANK3 expression was increased in the neocortex of TLE patients and rats. These results indicate that SHANK3 participates in the pathology of epilepsy.

Application of a temporal reasoning framework tool in analysis of medical device adverse events.

PubMed

Clark, Kimberly K; Sharma, Deepak K; Chute, Christopher G; Tao, Cui

2011-01-01

The Clinical Narrative Temporal Relation Ontology (CNTRO)1 project offers a semantic-web based reasoning framework, which represents temporal events and relationships within clinical narrative texts, and infer new knowledge over them. In this paper, the CNTRO reasoning framework is applied to temporal analysis of medical device adverse event files. One specific adverse event was used as a test case: late stent thrombosis. Adverse event narratives were obtained from the Food and Drug Administration's (FDA) Manufacturing and User Facility Device Experience (MAUDE) database2. 15 adverse event files in which late stent thrombosis was confirmed were randomly selected across multiple drug eluting stent devices. From these files, 81 events and 72 temporal relations were annotated. 73 temporal questions were generated, of which 65 were correctly answered by the CNTRO system. This results in an overall accuracy of 89%. This system should be pursued further to continue assessing its potential benefits in temporal analysis of medical device adverse events.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

PubMed

Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy

PubMed Central

Ehsan, Sheeba; Baker, Gus A.; Rogers, Timothy T.

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients’ accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency

Multiple PAR and E4BP4 bZIP transcription factors in zebrafish: diverse spatial and temporal expression patterns.

PubMed

Ben-Moshe, Zohar; Vatine, Gad; Alon, Shahar; Tovin, Adi; Mracek, Philipp; Foulkes, Nicholas S; Gothilf, Yoav

2010-09-01

Circadian rhythms of physiology and behavior are generated by an autonomous circadian oscillator that is synchronized daily with the environment, mainly by light input. The PAR subfamily of transcriptional activators and the related E4BP4 repressor belonging to the basic leucine zipper (bZIP) family are clock-controlled genes that are suggested to mediate downstream circadian clock processes and to feedback onto the core oscillator. Here, the authors report the characterization of these genes in the zebrafish, an increasingly important model in the field of chronobiology. Five novel PAR and six novel e4bp4 zebrafish homolog genes were identified using bioinformatic tools and their coding sequences were cloned. Based on their evolutionary relationships, these genes were annotated as ztef2, zhlf1 and zhlf2, zdbp1 and zdbp2, and ze4bp4-1 to -6. The spatial and temporal mRNA expression pattern of each of these factors was characterized in zebrafish embryos in the context of a functional circadian clock and regulation by light. Nine of the factors exhibited augmented and rhythmic expression in the pineal gland, a central clock organ in zebrafish. Moreover, these genes were found to be regulated, to variable extents, by the circadian clock and/or by light. Differential expression patterns of multiple paralogs in zebrafish suggest multiple roles for these factors within the vertebrate circadian clock. This study, in the genetically accessible zebrafish model, lays the foundation for further research regarding the involvement and specific roles of PAR and E4BP4 transcription factors in the vertebrate circadian clock mechanism.

Impacts of education level and employment status on health-related quality of life in multiple sclerosis patients.

PubMed

Šabanagić-Hajrić, Selma; Alajbegović, Azra

2015-02-01

To evaluate the impacts of education level and employment status on health-related quality of life (HRQoL) in multiple sclerosis patients. This study included 100 multiple sclerosis patients treated at the Department of Neurology, Clinical Center of the University of Sarajevo. Inclusion criteria were the Expanded Disability Status Scale (EDSS) score between 1.0 and 6.5, age between 18 and 65 years, stable disease on enrollment. Quality of life (QoL) was evaluated by the Multiple Sclerosis Quality of Life-54 questionnaire (MSQoL-54). Mann-Whitney and Kruskal-Wallis test were used for comparisons. Linear regression analyses were performed to evaluate prediction value of educational level and employment status in predicting MSQOL-54 physical and mental composite scores. Full employment status had positive impact on physical health (54.85 vs. 37.90; p les than 0.001) and mental health (59.55 vs. 45.90; p les than 0.001) composite scores. Employment status retained its independent predictability for both physical (r(2)=0.105) and mental (r(2)=0.076) composite scores in linear regression analysis. Patients with college degree had slightly higher median value of physical (49.36 vs. 45.30) and mental health composite score (66.74 vs. 55.62) comparing to others, without statistically significant difference. Employment proved to be an important factor in predicting quality of life in multiple sclerosis patients. Higher education level may determine better QOL but without significant predictive value. Sustained employment and development of vocational rehabilitation programs for MS patients living in the country with high unemployment level is an important factor in improving both physical and mental health outcomes in MS patients.

Quantifying the Spatio-temporal Impacts of Sea Level Rise on Carbon Storage Using Repeat Lidar Surveys and Multispectral Satellite Imagery

NASA Astrophysics Data System (ADS)

Smart, L.; Taillie, P. J.; Smith, J. W.; Meentemeyer, R. K.

2017-12-01

Sound coastal land-use policy and management decisions to mitigate or adapt to sea level rise impacts depend on understanding vegetation responses to sea level rise over large extents. Accurate methodologies to quantify these changes are necessary to understand the continued production of the ecosystem services upon which human health and well-being depend. This research quantifies spatio-temporal changes in aboveground biomass altered by sea level rise across North Carolina's coastal plain using a combination of repeat-acquisition lidar data and multi-temporal satellite imagery. Using field data from across the study area, we evaluated the reliability of multi-temporal lidar data with disparate densities and accuracies to detect changes along a coastal vegetation gradient from marsh to forested wetland. Despite an 18 fold increase in lidar point density between survey years (2001, 2014), the relationships between lidar-derived heights and field-measured heights were similar (adjusted r2; 0.6 -0.7). Random Forest, a machine learning algorithm, was used to separately predict above-ground biomass pools at the landscape-scale for the two time periods using the 98 field plots as reference data. Models performed well for both years (adjusted r2; 0.67-0.85). The 2001 model required the addition of Landsat spectral indices to meet the same adjusted r2 values as the 2014 model, which utilized lidar-derived metrics alone. Of the many potential lidar-derived predictor metrics, median and mean vegetation height were the best predictors in both time periods. To measure the spatial patterns of biomass change across the landscape, we subtracted the 2001 biomass model from the 2014 model and found significant spatial heterogeneity in biomass change across both the vegetation gradient and across the peninsula over the 12-year time period. In forested areas, we found a mean increase in aboveground biomass whereas in transition zones, marshes and freshwater emergent wetlands we

It's about time: revisiting temporal processing deficits in dyslexia.

PubMed

Casini, Laurence; Pech-Georgel, Catherine; Ziegler, Johannes C

2018-03-01

Temporal processing in French children with dyslexia was evaluated in three tasks: a word identification task requiring implicit temporal processing, and two explicit temporal bisection tasks, one in the auditory and one in the visual modality. Normally developing children matched on chronological age and reading level served as a control group. Children with dyslexia exhibited robust deficits in temporal tasks whether they were explicit or implicit and whether they involved the auditory or the visual modality. First, they presented larger perceptual variability when performing temporal tasks, whereas they showed no such difficulties when performing the same task on a non-temporal dimension (intensity). This dissociation suggests that their difficulties were specific to temporal processing and could not be attributed to lapses of attention, reduced alertness, faulty anchoring, or overall noisy processing. In the framework of cognitive models of time perception, these data point to a dysfunction of the 'internal clock' of dyslexic children. These results are broadly compatible with the recent temporal sampling theory of dyslexia. © 2017 John Wiley & Sons Ltd.

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

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

PubMed

Hyun, Seung Won; Wong, Weng Kee

2015-11-01

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.

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity

PubMed Central

2014-01-01

Background Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. Results In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. Conclusions In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity.

PubMed

Kesäniemi, Jenni E; Mustonen, Marina; Boström, Christoffer; Hansen, Benni W; Knott, K Emily

2014-01-22

Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub

Sobering up: A Quantitative Review of Temporal Declines in Expectations

ERIC Educational Resources Information Center

Sweeny, Kate; Krizan, Zlatan

2013-01-01

Although people's outlook on the future tends to be characterized by hope and optimism, over time this outlook often becomes more dire. We review multiple theoretical accounts of this tendency to "sober up" as feedback about outcomes draws near, and we explicate factors critical to promoting these temporal declines in expectations. We then…

Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

PubMed

Ahmedov, Merdin Lyutviev; Kemerdere, Rahsan; Baran, Oguz; Inal, Berrin Bercik; Gumus, Alper; Coskun, Cihan; Yeni, Seher Naz; Eren, Bulent; Uzan, Mustafa; Tanriverdi, Taner

2017-10-01

We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r 2  = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r 2  = 0.7, P = 0.00001 and r 2  = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r 2  = 0.06, P = 0.00001). Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Temporal motifs reveal homophily, gender-specific patterns, and group talk in call sequences.

PubMed

Kovanen, Lauri; Kaski, Kimmo; Kertész, János; Saramäki, Jari

2013-11-05

Recent studies on electronic communication records have shown that human communication has complex temporal structure. We study how communication patterns that involve multiple individuals are affected by attributes such as sex and age. To this end, we represent the communication records as a colored temporal network where node color is used to represent individuals' attributes, and identify patterns known as temporal motifs. We then construct a null model for the occurrence of temporal motifs that takes into account the interaction frequencies and connectivity between nodes of different colors. This null model allows us to detect significant patterns in call sequences that cannot be observed in a static network that uses interaction frequencies as link weights. We find sex-related differences in communication patterns in a large dataset of mobile phone records and show the existence of temporal homophily, the tendency of similar individuals to participate in communication patterns beyond what would be expected on the basis of their average interaction frequencies. We also show that temporal patterns differ between dense and sparse neighborhoods in the network. Because also this result is independent of interaction frequencies, it can be seen as an extension of Granovetter's hypothesis to temporal networks.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay

PubMed Central

Mahoney, J. Matthew; Titiz, Ali S.; Hernan, Amanda E.; Scott, Rod C.

2016-01-01

Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation. PMID:26866597

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.

Spatial and Temporal Scaling of Thermal Infrared Remote Sensing Data

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Goel, Narendra S.

1995-01-01

Although remote sensing has a central role to play in the acquisition of synoptic data obtained at multiple spatial and temporal scales to facilitate our understanding of local and regional processes as they influence the global climate, the use of thermal infrared (TIR) remote sensing data in this capacity has received only minimal attention. This results from some fundamental challenges that are associated with employing TIR data collected at different space and time scales, either with the same or different sensing systems, and also from other problems that arise in applying a multiple scaled approach to the measurement of surface temperatures. In this paper, we describe some of the more important problems associated with using TIR remote sensing data obtained at different spatial and temporal scales, examine why these problems appear as impediments to using multiple scaled TIR data, and provide some suggestions for future research activities that may address these problems. We elucidate the fundamental concept of scale as it relates to remote sensing and explore how space and time relationships affect TIR data from a problem-dependency perspective. We also describe how linearity and non-linearity observation versus parameter relationships affect the quantitative analysis of TIR data. Some insight is given on how the atmosphere between target and sensor influences the accurate measurement of surface temperatures and how these effects will be compounded in analyzing multiple scaled TIR data. Last, we describe some of the challenges in modeling TIR data obtained at different space and time scales and discuss how multiple scaled TIR data can be used to provide new and important information for measuring and modeling land-atmosphere energy balance processes.

Temporally graded semantic memory loss in amnesia and semantic dementia: Further evidence for opposite gradients.

PubMed

Estmacott, Robyn W; Moscovitch, Morris

2002-03-01

The consolidation theory of long-term memory (e.g., Squire, 1992) predicts that damage to the medial temporal lobes will result in temporally graded retrograde memory loss, with a disproportionate impairment of recent relative to remote knowledge; in contrast, severe atrophy of the temporal neocortex is predicted to result in the reverse temporally graded pattern, with a selective sparing of recent memory (K.S. Graham & Hodges, 1997). Previously, we reported evidence that autobiographical episodic memory does not follow this temporal pattern (Westmacott, Leach, Freedman, & Moscovitch, 2001). In the present study, we found evidence suggesting that semantic memory loss does follow the predicted temporal pattern. We used a set of tasks that tap implicit and explicit memory for famous names and English vocabulary terms from across the 20th century. KC, a person with medial temporal amnesia, consistently demonstrated across tasks a selective deficit for famous names and vocabulary terms from the 5-year period just prior to injury; this deficit was particularly profound for elaborated semantic knowledge (e.g., word definitions, occupation of famous person). However, when asked to guess on unfamiliar items, KC's performance for names and words from this 5-year time period increased substantially, suggesting that he retains some of this knowledge at an implicit or rudimentary level. Conversely, EL, a semantic dementia patient with temporal neocortical atrophy and relative sparing of the medial temporal lobe, demonstrated a selective sparing of names and words from the most recent time period. However, this selective sparing of recent semantic memory was demonstrated in the implicit tasks only; performance on explicit tasks suggested an equally severe impairment of semantics across all time periods. Unlike the data from our previous study of autobiographical episodic memory, these findings are consistent with the predictions both of consolidation theory (Hodges & Graham

The Relationship between National-Level Carbon Dioxide Emissions and Population Size: An Assessment of Regional and Temporal Variation, 1960–2005

PubMed Central

Jorgenson, Andrew K.; Clark, Brett

2013-01-01

This study examines the regional and temporal differences in the statistical relationship between national-level carbon dioxide emissions and national-level population size. The authors analyze panel data from 1960 to 2005 for a diverse sample of nations, and employ descriptive statistics and rigorous panel regression modeling techniques. Initial descriptive analyses indicate that all regions experienced overall increases in carbon emissions and population size during the 45-year period of investigation, but with notable differences. For carbon emissions, the sample of countries in Asia experienced the largest percent increase, followed by countries in Latin America, Africa, and lastly the sample of relatively affluent countries in Europe, North America, and Oceania combined. For population size, the sample of countries in Africa experienced the largest percent increase, followed countries in Latin America, Asia, and the combined sample of countries in Europe, North America, and Oceania. Findings for two-way fixed effects panel regression elasticity models of national-level carbon emissions indicate that the estimated elasticity coefficient for population size is much smaller for nations in Africa than for nations in other regions of the world. Regarding potential temporal changes, from 1960 to 2005 the estimated elasticity coefficient for population size decreased by 25% for the sample of Africa countries, 14% for the sample of Asia countries, 6.5% for the sample of Latin America countries, but remained the same in size for the sample of countries in Europe, North America, and Oceania. Overall, while population size continues to be the primary driver of total national-level anthropogenic carbon dioxide emissions, the findings for this study highlight the need for future research and policies to recognize that the actual impacts of population size on national-level carbon emissions differ across both time and region. PMID:23437323

Hierarchical organization in the temporal structure of infant-direct speech and song.

PubMed

Falk, Simone; Kello, Christopher T

2017-06-01

Caregivers alter the temporal structure of their utterances when talking and singing to infants compared with adult communication. The present study tested whether temporal variability in infant-directed registers serves to emphasize the hierarchical temporal structure of speech. Fifteen German-speaking mothers sang a play song and told a story to their 6-months-old infants, or to an adult. Recordings were analyzed using a recently developed method that determines the degree of nested clustering of temporal events in speech. Events were defined as peaks in the amplitude envelope, and clusters of various sizes related to periods of acoustic speech energy at varying timescales. Infant-directed speech and song clearly showed greater event clustering compared with adult-directed registers, at multiple timescales of hundreds of milliseconds to tens of seconds. We discuss the relation of this newly discovered acoustic property to temporal variability in linguistic units and its potential implications for parent-infant communication and infants learning the hierarchical structures of speech and language. Copyright © 2017 Elsevier B.V. All rights reserved.

Event construal and temporal distance in natural language.

PubMed

Bhatia, Sudeep; Walasek, Lukasz

2016-07-01

Construal level theory proposes that events that are temporally proximate are represented more concretely than events that are temporally distant. We tested this prediction using two large natural language text corpora. In study 1 we examined posts on Twitter that referenced the future, and found that tweets mentioning temporally proximate dates used more concrete words than those mentioning distant dates. In study 2 we obtained all New York Times articles that referenced U.S. presidential elections between 1987 and 2007. We found that the concreteness of the words in these articles increased with the temporal proximity to their corresponding election. Additionally the reduction in concreteness after the election was much greater than the increase in concreteness leading up to the election, though both changes in concreteness were well described by an exponential function. We replicated this finding with New York Times articles referencing US public holidays. Overall, our results provide strong support for the predictions of construal level theory, and additionally illustrate how large natural language datasets can be used to inform psychological theory. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Controller design for a class of nonlinear MIMO coupled system using multiple models and second level adaptation.

PubMed

Pandey, Vinay Kumar; Kar, Indrani; Mahanta, Chitralekha

2017-07-01

In this paper, an adaptive control method using multiple models with second level adaptation is proposed for a class of nonlinear multi-input multi-output (MIMO) coupled systems. Multiple estimation models are used to tune the unknown parameters at the first level. The second level adaptation provides a single parameter vector for the controller. A feedback linearization technique is used to design a state feedback control. The efficacy of the designed controller is validated by conducting real time experiment on a laboratory setup of twin rotor MIMO system (TRMS). The TRMS setup is discussed in detail and the experiments were performed for regulation and tracking problem for pitch and yaw control using different reference signals. An Extended Kalman Filter (EKF) has been used to observe the unavailable states of the TRMS. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Auditory temporal processing in patients with temporal lobe epilepsy.

PubMed

Lavasani, Azam Navaei; Mohammadkhani, Ghassem; Motamedi, Mahmoud; Karimi, Leyla Jalilvand; Jalaei, Shohreh; Shojaei, Fereshteh Sadat; Danesh, Ali; Azimi, Hadi

2016-07-01

Auditory temporal processing is the main feature of speech processing ability. Patients with temporal lobe epilepsy, despite their normal hearing sensitivity, may present speech recognition disorders. The present study was carried out to evaluate the auditory temporal processing in patients with unilateral TLE. The present study was carried out on 25 patients with epilepsy: 11 patients with right temporal lobe epilepsy and 14 with left temporal lobe epilepsy with a mean age of 31.1years and 18 control participants with a mean age of 29.4years. The two experimental and control groups were evaluated via gap-in-noise and duration pattern sequence tests. One-way ANOVA was run to analyze the data. The mean of the threshold of the GIN test in the control group was observed to be better than that in participants with LTLE and RTLE. Also, it was observed that the percentage of correct responses on the DPS test in the control group and in participants with RTLE was better than that in participants with LTLE. Patients with TLE have difficulties in temporal processing. Difficulties are more significant in patients with LTLE, likely because the left temporal lobe is specialized for the processing of temporal information. Copyright © 2016 Elsevier Inc. All rights reserved.

Temporal Immediacy: A Two-System Theory of Mind for Understanding and Changing Health Behaviors.

PubMed

Cook, Paul F; Schmiege, Sarah J; Reeder, Blaine; Horton-Deutsch, Sara; Lowe, Nancy K; Meek, Paula

Health promotion and chronic disease management both require behavior change, but people find it hard to change behavior despite having good intentions. The problem arises because patients' narratives about experiences and intentions are filtered through memory and language. These narratives inaccurately reflect intuitive decision-making or actual behaviors. We propose a principle-temporal immediacy-as a moderator variable that explains which of two mental systems (narrative or intuitive) will be activated in any given situation. We reviewed multiple scientific areas to test temporal immediacy as an explanation for findings. In an iterative process, we used evidence from philosophy, cognitive neuroscience, behavioral economics, symptom science, and ecological momentary assessment to develop our theoretical perspective. These perspectives each suggest two cognitive systems that differ in their level of temporal immediacy: an intuitive system that produces behavior in response to everyday states and a narrative system that interprets and explains these experiences after the fact. Writers from Plato onward describe two competing influences on behavior-often with moral overtones. People tend to identify with the language-based narrative system and blame unhelpful results on the less accessible intuitive system, but neither is completely rational, and the intuitive system has strengths based on speed and serial processing. The systems differ based on temporal immediacy-the description of an experience as either "now" or "usually"-with the intuitive system generating behaviors automatically in real time and the narrative system producing beliefs about the past or future. The principle of temporal immediacy is a tool to integrate nursing science with other disciplinary traditions and to improve research and practice. Interventions should build on each system's strengths, rather than treating the intuitive system as a barrier for the narrative system to overcome. Nursing

Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN) Framework

PubMed Central

Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

2013-01-01

Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management. PMID:24287859

Monitoring street-level spatial-temporal variations of carbon monoxide in urban settings using a wireless sensor network (WSN) framework.

PubMed

Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

2013-11-27

Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

Temporal prediction errors modulate task-switching performance

PubMed Central

Limongi, Roberto; Silva, Angélica M.; Góngora-Costa, Begoña

2015-01-01

We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus’ onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as “executive control” is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching. PMID:26379568

Temporal prediction errors modulate task-switching performance.

PubMed

Limongi, Roberto; Silva, Angélica M; Góngora-Costa, Begoña

2015-01-01

We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus' onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as "executive control" is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching.

a Web-Based Interactive Platform for Co-Clustering Spatio-Temporal Data

NASA Astrophysics Data System (ADS)

Wu, X.; Poorthuis, A.; Zurita-Milla, R.; Kraak, M.-J.

2017-09-01

Since current studies on clustering analysis mainly focus on exploring spatial or temporal patterns separately, a co-clustering algorithm is utilized in this study to enable the concurrent analysis of spatio-temporal patterns. To allow users to adopt and adapt the algorithm for their own analysis, it is integrated within the server side of an interactive web-based platform. The client side of the platform, running within any modern browser, is a graphical user interface (GUI) with multiple linked visualizations that facilitates the understanding, exploration and interpretation of the raw dataset and co-clustering results. Users can also upload their own datasets and adjust clustering parameters within the platform. To illustrate the use of this platform, an annual temperature dataset from 28 weather stations over 20 years in the Netherlands is used. After the dataset is loaded, it is visualized in a set of linked visualizations: a geographical map, a timeline and a heatmap. This aids the user in understanding the nature of their dataset and the appropriate selection of co-clustering parameters. Once the dataset is processed by the co-clustering algorithm, the results are visualized in the small multiples, a heatmap and a timeline to provide various views for better understanding and also further interpretation. Since the visualization and analysis are integrated in a seamless platform, the user can explore different sets of co-clustering parameters and instantly view the results in order to do iterative, exploratory data analysis. As such, this interactive web-based platform allows users to analyze spatio-temporal data using the co-clustering method and also helps the understanding of the results using multiple linked visualizations.

RedeR: R/Bioconductor package for representing modular structures, nested networks and multiple levels of hierarchical associations

PubMed Central

2012-01-01

Visualization and analysis of molecular networks are both central to systems biology. However, there still exists a large technological gap between them, especially when assessing multiple network levels or hierarchies. Here we present RedeR, an R/Bioconductor package combined with a Java core engine for representing modular networks. The functionality of RedeR is demonstrated in two different scenarios: hierarchical and modular organization in gene co-expression networks and nested structures in time-course gene expression subnetworks. Our results demonstrate RedeR as a new framework to deal with the multiple network levels that are inherent to complex biological systems. RedeR is available from http://bioconductor.org/packages/release/bioc/html/RedeR.html. PMID:22531049

Evolutionary history of Daphnia drives divergence in grazing selectivity and alters temporal community dynamics of producers.

PubMed

Park, John S; Post, David M

2018-01-01

Consumers with different seasonal life histories encounter different communities of producers during specific seasonal phases. If consumers evolve to prefer the producers that they encounter, then consumers may reciprocally influence the temporal composition of producer communities. Here, we study the keystone consumer Daphnia ambigua, whose seasonal life history has diverged due to intraspecific predator divergence across lakes of New England. We ask whether grazing preferences of Daphnia have diverged also and test whether any grazing differences influence temporal composition patterns of producers. We reared clonal populations of Daphnia from natural populations representing the two diverged life history types for multiple generations. We conducted short-term (24 hr) and long-term (27 days) grazing experiments in equal polycultures consisting of three diatom and two green algae species, treated with no consumer, Daphnia from lakes with anadromous alewife, or from lakes with landlocked alewife. After 24 hr, life history and grazing preference divergence in Daphnia ambigua drove significant differences in producer composition. However, those differences disappeared at the end of the 27-day experiment. Our results illustrate that, despite potentially more complex long-term dynamics, a multitrophic cascade of evolutionary divergence from a predator can influence temporal community dynamics at the producer level.

The temporal representation of the delay of dynamic iterated rippled noise with positive and negative gain by single units in the ventral cochlear nucleus.

PubMed

Sayles, Mark; Winter, Ian Michael

2007-09-26

Spike trains were recorded from single units in the ventral cochlear nucleus of the anaesthetised guinea-pig in response to dynamic iterated rippled noise with positive and negative gain. The short-term running waveform autocorrelation functions of these stimuli show peaks at integer multiples of the time-varying delay when the gain is +1, and troughs at odd-integer multiples and peaks at even-integer multiples of the time-varying delay when the gain is -1. In contrast, the short-term autocorrelation of the Hilbert envelope shows peaks at integer multiples of the time-varying delay for both positive and negative gain stimuli. A running short-term all-order interspike interval analysis demonstrates the ability of single units to represent the modulated pitch contour in their short-term interval statistics. For units with low best frequency (approximate < or = 1.1 kHz) the temporal discharge pattern reflected the waveform fine structure regardless of unit classification (Primary-like, Chopper). For higher best frequency units the pattern of response varied according to unit type. Chopper units with best frequency approximate > or = 1.1 kHz responded to envelope modulation; showing no difference between their response to stimuli with positive and negative gain. Primary-like units with best frequencies in the range 1-3 kHz were still able to represent the difference in the temporal fine structure between dynamic rippled noise with positive and negative gain. No unit with a best frequency above 3 kHz showed a response to the temporal fine structure. Chopper units in this high frequency group showed significantly greater representation of envelope modulation relative to primary-like units with the same range of best frequencies. These results show that at the level of the cochlear nucleus there exists sufficient information in the time domain to represent the time-varying pitch associated with dynamic iterated rippled noise.

Contrasting outcomes of species- and community-level analyses of the temporal consistency of functional composition.

PubMed

Katabuchi, Masatoshi; Wright, S Joseph; Swenson, Nathan G; Feeley, Kenneth J; Condit, Richard; Hubbell, Stephen P; Davies, Stuart J

2017-09-01

Multiple anthropogenic drivers affect every natural community, and there is broad interest in using functional traits to understand and predict the consequences for future biodiversity. There is, however, no consensus regarding the choice of analytical methods. We contrast species- and community-level analyses of change in the functional composition for four traits related to drought tolerance using three decades of repeat censuses of trees in the 50-ha Forest Dynamics Plot on Barro Colorado Island, Panama. Community trait distributions shifted significantly through time, which may indicate a shift toward more drought tolerant species. However, at the species level, changes in abundance were unrelated to trait values. To reconcile these seemingly contrasting results, we evaluated species-specific contributions to the directional shifts observed at the community level. Abundance changes of just one to six of 312 species were responsible for the community-level shifts observed for each trait. Our results demonstrate that directional changes in community-level functional composition can result from idiosyncratic change in a few species rather than widespread community-wide changes associated with functional traits. Future analyses of directional change in natural communities should combine community-, species-, and possibly individual-level analyses to uncover relationships with function that can improve understanding and enable prediction. © 2017 by the Ecological Society of America.

Enhancing the Temporal Complexity of Distributed Brain Networks with Patterned Cerebellar Stimulation

PubMed Central

Farzan, Faranak; Pascual-Leone, Alvaro; Schmahmann, Jeremy D.; Halko, Mark

2016-01-01

Growing evidence suggests that sensory, motor, cognitive and affective processes map onto specific, distributed neural networks. Cerebellar subregions are part of these networks, but how the cerebellum is involved in this wide range of brain functions remains poorly understood. It is postulated that the cerebellum contributes a basic role in brain functions, helping to shape the complexity of brain temporal dynamics. We therefore hypothesized that stimulating cerebellar nodes integrated in different networks should have the same impact on the temporal complexity of cortical signals. In healthy humans, we applied intermittent theta burst stimulation (iTBS) to the vermis lobule VII or right lateral cerebellar Crus I/II, subregions that prominently couple to the dorsal-attention/fronto-parietal and default-mode networks, respectively. Cerebellar iTBS increased the complexity of brain signals across multiple time scales in a network-specific manner identified through electroencephalography (EEG). We also demonstrated a region-specific shift in power of cortical oscillations towards higher frequencies consistent with the natural frequencies of targeted cortical areas. Our findings provide a novel mechanism and evidence by which the cerebellum contributes to multiple brain functions: specific cerebellar subregions control the temporal dynamics of the networks they are engaged in. PMID:27009405

Evaluation of the role of 8-iso-PGF levels at multiple sites during intracranial hemorrhage in pediatric patients.

PubMed

Qi, B-X; Yao, H; Shang, L; Sheng, L-P; Wang, X-C; Zhu, L; Zhang, X-X; Wang, J-P; Fang, D-H

2017-09-01

The present study was planned to explore the role of 8-isomeric-prostaglandinF2α (8-iso-PGF2α) levels at the multiple sites of cerebrospinal fluid in children with intracranial hemorrhage. 90 children with intracranial hemorrhage were admitted to Surgery Intensive Care Unit (SICU) of our hospital from January to December 2013 and were selected as study subjects. They were divided into group A (n=30), group B (n=30) and group C (n=30). The group A was given conventional treatment, the group B was treated with minimally invasive puncture and the group C was treated with cerebrospinal fluid decompression. After 1 d, 2 d, 3 d, and 7 d of hospitalization, enzyme-linked immunosorbent assay (ELISA) was used to detect the 8-iso-PGF2α levels in peripheral blood of children in all groups. On the day of admission and 10 d after treatment, 3 groups of children were implemented with brain nuclear magnetic resonance spectroscopy for metabolite analyses. On the day of admission there were no significant differences in the 8-iso-PGF2α levels among group A, B and C. Further, after 1 d, 3 d, 7 d of hospital stay, the 8-iso-PGF2α levels in peripheral blood showed a gradual downward trend, and decline range of the group C was greater than that of group A and B (p < 0.05). After 10 days of treatment, there were significant differences in the bilateral temporal lobe and hippocampal NAA/Creatinine (Cr), Cho/Cr, mI/Cr and NAA/mI among group A, B, and C. The survival rate of group C was higher than that of group A and B (p < 0.05). On the other hand, the prevalence of sequelae was significantly lower than that of group A and B (p < 0.05). The amount of blood loss in children with intracranial hemorrhage was positively correlated with the levels of 8-iso-PGF2α in peripheral blood (r = 0.546, p < 0.05) as observed by Spearman correlation analysis. 8-iso-PGF2α plays an important role in the pathogenesis of intracranial hemorrhage, and could be utilized as a biomarker of oxidative

Temporal system-level organization of the switch from glycolytic to gluconeogenic operation in yeast

PubMed Central

Zampar, Guillermo G; Kümmel, Anne; Ewald, Jennifer; Jol, Stefan; Niebel, Bastian; Picotti, Paola; Aebersold, Ruedi; Sauer, Uwe; Zamboni, Nicola; Heinemann, Matthias

2013-01-01

The diauxic shift in Saccharomyces cerevisiae is an ideal model to study how eukaryotic cells readjust their metabolism from glycolytic to gluconeogenic operation. In this work, we generated time-resolved physiological data, quantitative metabolome (69 intracellular metabolites) and proteome (72 enzymes) profiles. We found that the diauxic shift is accomplished by three key events that are temporally organized: (i) a reduction in the glycolytic flux and the production of storage compounds before glucose depletion, mediated by downregulation of phosphofructokinase and pyruvate kinase reactions; (ii) upon glucose exhaustion, the reversion of carbon flow through glycolysis and onset of the glyoxylate cycle operation triggered by an increased expression of the enzymes that catalyze the malate synthase and cytosolic citrate synthase reactions; and (iii) in the later stages of the adaptation, the shutting down of the pentose phosphate pathway with a change in NADPH regeneration. Moreover, we identified the transcription factors associated with the observed changes in protein abundances. Taken together, our results represent an important contribution toward a systems-level understanding of how this adaptation is realized. PMID:23549479

Temporal lobe anatomy: eight imaging signs to facilitate interpretation of MRI.

PubMed

Lehman, Vance T; Black, David F; Bernstein, Matt A; Welker, Kirk M

2016-05-01

The temporal lobe is anatomically and functionally complex. However, relatively few radiologic signs are described to facilitate recognition of temporal lobe sulci and gyri in clinical practice. We devised and tested 8 radiologic signs of temporal lobe anatomy. Images from volumetric magnetization-prepared rapid gradient-echo imaging were analyzed of 100 temporal lobes from 26 female and 24 male patients. Patient age ranged from 1 to 79 years (mean 19 years; standard deviation 16 years). Standardized axial, coronal, and sagittal planes were evaluated and cross-referenced. Eight signs to delineate the superior temporal gyrus, Heschl gyrus (HG), parahippocampal gyrus, rhinal sulcus, collateral sulcus proper, or the occipitotemporal sulcus, or a combination, were evaluated in the sagittal or axial plane. Two neuroradiologists independently evaluated each sign; the sign was considered present only with positive reader agreement. All 8 signs were present in most patients. The most frequent signs were the posterior insular corner to identify HG in the axial plane (100 %), pointed STG to identify STG in the axial plane (98 %), and parahippocampal Y to identify the posterior parahippocampal gyrus in the sagittal plane (98 %). The frequencies were similar between the right and left cerebral hemispheres. Temporal lobe gyri and sulci can be reliably identified in multiple planes using anatomic signs.

Temporal Characteristics of Electron Flux Events at Geosynchronous Orbit

NASA Astrophysics Data System (ADS)

Olson, D. K.; Larsen, B.; Henderson, M. G.

2017-12-01

Geosynchronous satellites such as the LANL-GEO fleet are exposed to hazardous conditions when they encounter regions of hot, intense plasma such as that from the plasma sheet. These conditions can lead to the build-up of charge on the surface of a spacecraft, with undesired, and often dangerous, side effects. Observation of electron flux levels at geosynchronous orbit (GEO) with multiple satellites provides a unique view of plasma sheet access to that region. Flux "events", or periods when fluxes are elevated continuously above the LANL-GEO spacecraft charging threshold, can be characterized by duration in two dimensions: a spatial dimension of local time, describing the duration of an event from the perspective of a single spacecraft, and a temporal dimension describing the duration in time in which high energy plasma sheet particles have access to geosynchronous orbit. We examine the statistical properties of the temporal duration of 8 keV electron flux events at geosynchronous orbit over a twelve-year period. These results, coupled with the spatial duration characteristics, provide the key information needed to formulate a statistical model for forecasting the electron flux conditions at GEO that are correlated with LANL-GEO surface charging. Forecasting models are an essential component to understanding space weather and mitigating the dangers of surface charging on our satellites. We also examine the correlation of flux event durations with solar wind parameters and geomagnetic indices, identifying the data needed to improve upon a statistical forecasting model

Temporal motifs reveal homophily, gender-specific patterns, and group talk in call sequences

PubMed Central

Kovanen, Lauri; Kaski, Kimmo; Kertész, János; Saramäki, Jari

2013-01-01

Recent studies on electronic communication records have shown that human communication has complex temporal structure. We study how communication patterns that involve multiple individuals are affected by attributes such as sex and age. To this end, we represent the communication records as a colored temporal network where node color is used to represent individuals’ attributes, and identify patterns known as temporal motifs. We then construct a null model for the occurrence of temporal motifs that takes into account the interaction frequencies and connectivity between nodes of different colors. This null model allows us to detect significant patterns in call sequences that cannot be observed in a static network that uses interaction frequencies as link weights. We find sex-related differences in communication patterns in a large dataset of mobile phone records and show the existence of temporal homophily, the tendency of similar individuals to participate in communication patterns beyond what would be expected on the basis of their average interaction frequencies. We also show that temporal patterns differ between dense and sparse neighborhoods in the network. Because also this result is independent of interaction frequencies, it can be seen as an extension of Granovetter’s hypothesis to temporal networks. PMID:24145424

Temporally Graded Activation of Neocortical Regions in Response to Memories of Different Ages

PubMed Central

Woodard, John L.; Seidenberg, Michael; Nielson, Kristy A.; Miller, Sarah K.; Franczak, Malgorzata; Antuono, Piero; Douville, Kelli L.; Rao, Stephen M.

2007-01-01

The temporally graded memory impairment seen in many neurobehavioral disorders implies different neuroanatomical pathways and/or cognitive mechanisms involved in storage and retrieval of memories of different ages. A dynamic interaction between medial-temporal and neocortical brain regions has been proposed to account for memory’s greater permanence with time. Despite considerable debate concerning its time-dependent role in memory retrieval, medial-temporal lobe activity has been well studied. However, the relative participation of neocortical regions in recent and remote memory retrieval has received much less attention. Using functional magnetic resonance imaging, we demonstrate robust, temporally graded signal differences in posterior cingulate, right middle frontal, right fusiform, and left middle temporal regions in healthy older adults during famous name identification from two disparate time epochs. Importantly, no neocortical regions demonstrated greater response to older than to recent stimuli. Our results suggest a possible role of these neocortical regions in temporally dating items in memory and in establishing and maintaining memory traces throughout the lifespan. Theoretical implications of these findings for the two dominant models of remote memory functioning (Consolidation Theory and Multiple Trace Theory) are discussed. PMID:17583988

A novel multiple description scalable coding scheme for mobile wireless video transmission

NASA Astrophysics Data System (ADS)

Zheng, Haifeng; Yu, Lun; Chen, Chang Wen

2005-03-01

We proposed in this paper a novel multiple description scalable coding (MDSC) scheme based on in-band motion compensation temporal filtering (IBMCTF) technique in order to achieve high video coding performance and robust video transmission. The input video sequence is first split into equal-sized groups of frames (GOFs). Within a GOF, each frame is hierarchically decomposed by discrete wavelet transform. Since there is a direct relationship between wavelet coefficients and what they represent in the image content after wavelet decomposition, we are able to reorganize the spatial orientation trees to generate multiple bit-streams and employed SPIHT algorithm to achieve high coding efficiency. We have shown that multiple bit-stream transmission is very effective in combating error propagation in both Internet video streaming and mobile wireless video. Furthermore, we adopt the IBMCTF scheme to remove the redundancy for inter-frames along the temporal direction using motion compensated temporal filtering, thus high coding performance and flexible scalability can be provided in this scheme. In order to make compressed video resilient to channel error and to guarantee robust video transmission over mobile wireless channels, we add redundancy to each bit-stream and apply error concealment strategy for lost motion vectors. Unlike traditional multiple description schemes, the integration of these techniques enable us to generate more than two bit-streams that may be more appropriate for multiple antenna transmission of compressed video. Simulate results on standard video sequences have shown that the proposed scheme provides flexible tradeoff between coding efficiency and error resilience.

Investigating the Resilience Levels of Parents with Children with Multiple Disabilities Based on Different Variables

ERIC Educational Resources Information Center

Kadi, Sinem; Eldeniz Cetin, Muzeyyen

2018-01-01

This study investigated the resilience levels of parents with children with multiple disabilities by utilizing different variables. The study, conducted with survey model--a qualitative method--included a sample composed of a total of 222 voluntary parents (183 females, 39 males) residing in Bolu, Duzce and Zonguldak in Turkey. Parental…

The correlation between symptomatic fatigue to definite measures of gait in people with multiple sclerosis.

PubMed

Kalron, Alon

2016-02-01

There is a general consensus relating to the multidimensional aspects of fatigue in people with multiple sclerosis (PwMS), however, the exact impact of this symptom on gait is not fully understood. Our primary aim was to examine the relationship between definite parameters of gait with self-reported symptomatic fatigue in PwMS according to their level of neurological impairment. Spatio-temporal parameters of gait were studied using an electronic walkway. The Multiple Sclerosis Walking Scale (MSWS-12) questionnaire, a patient-rated measure of walking ability was collected. The Modified Fatigue Impact Scale (MFIS) questionnaire was used to determine the level of symptomatic fatigue. One hundred and one PwMS (61 women) were included in the study analysis. Subjects were divided into mild and moderate neurological impaired groups. Fatigue was correlated with 5 (out of 14) spatiotemporal parameters. However, correlation scores were all <0.35, thus considered as weak correlations. In the mild group, the double support period was the only variable positively correlated to fatigue (Spearman's rho=0.28, P=0.05). In the moderate group, step and stride length were solely negatively correlated to fatigue (Spearman's rho=0.32, P=0.03). In contrast to the definite gait parameters, the MSWS-12 self-questionnaire was moderately positively correlated to the level of fatigue. Scores for the total, mild and moderate groups were 0.54, 0.57 and 0.51; P<0.01, respectively. The present results indicate that modifications in spatio-temporal parameters of gait are not closely related to symptomatic fatigue in PwMS. On the contrary, the self-reported MSWS-12 questionnaire is predisposed to level of fatigue in PwMS. Copyright © 2015 Elsevier B.V. All rights reserved.

Soluble thrombomodulin levels in plasma of multiple sclerosis patients and their implication.

PubMed

Festoff, Barry W; Li, Chaoyang; Woodhams, Barry; Lynch, Sharon

2012-12-15

Thrombomodulin (TM) on the cell-surface of cerebrovascular endothelial cells (CECs) is released into blood upon CEC damage. TM promotes activation of protein C (APC), an anticoagulant, anti-inflammatory, neuroprotective molecule that protects CECs and impedes inflammatory cell migration across the blood-brain barrier (BBB). Multiple sclerosis (MS) is associated with CEC damage and BBB dysfunction. We evaluated soluble TM (sTM) levels as a biomarker of BBB integrity and whether glatiramer acetate (GA) influenced sTM levels in MS patients. sTM levels quantified by 2-site ELISA from sera of healthy controls and systemic lupus erythematosus (SLE) patients (CEC-damage positive control) were compared with levels from patients with relapsing-remitting (RRMS) or secondary-progressive MS (SPMS), stratified as: RRMS/GA/no relapse, RRMS/GA/in relapse, RRMS no GA/no relapse, RRMS/no GA/in relapse; and SPMS/no GA. Additionally, soluble endothelial protein C receptor (sEPCR) levels were assessed in the non-stratified MS group, SLE patients, and controls. sTM levels were highest in RRMS patients taking GA with or without relapse, followed in decreasing order by SLE, RRMS/no GA/in relapse, SPMS, RRMS/no GA/no relapse, healthy controls. sEPCR levels were highest in MS patients, then SLE, then controls. sTM may be a useful biomarker of BBB integrity in RRMS patients. Further evaluation of sEPCR is needed. The finding that the highest sTM levels were in RRMS patients taking GA is interesting and warrants further investigation. Published by Elsevier B.V.

Principal cells of the brainstem's interaural sound level detector are temporal differentiators rather than integrators.

PubMed

Franken, Tom P; Joris, Philip X; Smith, Philip H

2018-06-14

The brainstem's lateral superior olive (LSO) is thought to be crucial for localizing high-frequency sounds by coding interaural sound level differences (ILD). Its neurons weigh contralateral inhibition against ipsilateral excitation, making their firing rate a function of the azimuthal position of a sound source. Since the very first in vivo recordings, LSO principal neurons have been reported to give sustained and temporally integrating 'chopper' responses to sustained sounds. Neurons with transient responses were observed but largely ignored and even considered a sign of pathology. Using the Mongolian gerbil as a model system, we have obtained the first in vivo patch clamp recordings from labeled LSO neurons and find that principal LSO neurons, the most numerous projection neurons of this nucleus, only respond at sound onset and show fast membrane features suggesting an importance for timing. These results provide a new framework to interpret previously puzzling features of this circuit. © 2018, Franken et al.

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.

Temporal plus epilepsy is a major determinant of temporal lobe surgery failures.

PubMed

Barba, Carmen; Rheims, Sylvain; Minotti, Lorella; Guénot, Marc; Hoffmann, Dominique; Chabardès, Stephan; Isnard, Jean; Kahane, Philippe; Ryvlin, Philippe

2016-02-01

Reasons for failed temporal lobe epilepsy surgery remain unclear. Temporal plus epilepsy, characterized by a primary temporal lobe epileptogenic zone extending to neighboured regions, might account for a yet unknown proportion of these failures. In this study all patients from two epilepsy surgery programmes who fulfilled the following criteria were included: (i) operated from an anterior temporal lobectomy or disconnection between January 1990 and December 2001; (ii) magnetic resonance imaging normal or showing signs of hippocampal sclerosis; and (iii) postoperative follow-up ≥ 24 months for seizure-free patients. Patients were classified as suffering from unilateral temporal lobe epilepsy, bitemporal epilepsy or temporal plus epilepsy based on available presurgical data. Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom over time. Predictors of seizure recurrence were investigated using Cox proportional hazards model. Of 168 patients included, 108 (63.7%) underwent stereoelectroencephalography, 131 (78%) had hippocampal sclerosis, 149 suffered from unilateral temporal lobe epilepsy (88.7%), one from bitemporal epilepsy (0.6%) and 18 (10.7%) from temporal plus epilepsy. The probability of Engel class I outcome at 10 years of follow-up was 67.3% (95% CI: 63.4-71.2) for the entire cohort, 74.5% (95% CI: 70.6-78.4) for unilateral temporal lobe epilepsy, and 14.8% (95% CI: 5.9-23.7) for temporal plus epilepsy. Multivariate analyses demonstrated four predictors of seizure relapse: temporal plus epilepsy (P < 0.001), postoperative hippocampal remnant (P = 0.001), past history of traumatic or infectious brain insult (P = 0.022), and secondary generalized tonic-clonic seizures (P = 0.023). Risk of temporal lobe surgery failure was 5.06 (95% CI: 2.36-10.382) greater in patients with temporal plus epilepsy than in those with unilateral temporal lobe epilepsy. Temporal plus epilepsy represents a hitherto unrecognized prominent cause of

Accelerated long-term forgetting in temporal lobe epilepsy: evidence of improvement after left temporal pole lobectomy.

PubMed

Gallassi, Roberto; Sambati, Luisa; Poda, Roberto; Stanzani Maserati, Michelangelo; Oppi, Federico; Giulioni, Marco; Tinuper, Paolo

2011-12-01

Accelerated long term forgetting (ALF) is a characteristic cognitive aspect in patients affected by temporal lobe epilepsy that is probably due to an impairment of memory consolidation and retrieval caused by epileptic activity in hippocampal and parahippocampal regions. We describe a case of a patient with TLE who showed improvement in ALF and in remote memory impairment after an anterior left temporal pole lobectomy including the uncus and amygdala. Our findings confirm that impairment of hippocampal functioning leads to pathological ALF, whereas restoration of hippocampal functioning brings ALF to a level comparable to that of controls. Copyright © 2011 Elsevier Inc. All rights reserved.

Elevated soluble MUC1 levels and decreased anti-MUC1 antibody levels in patients with multiple myeloma.

PubMed

Treon, S P; Maimonis, P; Bua, D; Young, G; Raje, N; Mollick, J; Chauhan, D; Tai, Y T; Hideshima, T; Shima, Y; Hilgers, J; von Mensdorff-Pouilly, S; Belch, A R; Pilarski, L M; Anderson, K C

2000-11-01

Soluble MUC1 (sMUC1) levels are elevated in many MUC1(+) cancers. We and others have shown that MUC1 is expressed on multiple myeloma (MM) plasma cells and B cells. In this study, we measured sMUC1 levels in bone marrow (BM) plasma from 71 MM patients and 21 healthy donors (HDs), and in peripheral blood (PB) plasma from 42 MM patients and 13 HDs using an immunoassay that detects the CA27.29 epitope of MUC1. sMUC1 levels were found to be significantly greater (mean 31.76 U/mL, range 5.69 to 142.48 U/mL) in MM patient BM plasma versus HD BM plasma (mean 9.68 U/mL, range 0.65 to 39.83 U/mL) (P <. 001). Importantly, BM plasma sMUC1 levels were related to tumor burden because sMUC1 levels were significantly higher for MM patients with active disease (34.62 U/mL, range 5.69 to 142.48 U/mL) versus MM patients with minimal residual disease (16.16 U/mL, range 5.7 to 56.68 U/mL) (P =.0026). sMUC1 levels were also elevated in the PB plasma of MM patients (32.79 U/mL, range 4.15 to 148.84 U/mL) versus HDs (18.47 U/mL, range 8.84 to 42.49) (P =.0052). Lastly, circulating immunglobulin M (IgM) and IgG antibodies to MUC1 were measured in 114 MM patients and 31 HDs, because natural antibodies to MUC1 have been detected in patients with other MUC1-bearing malignancies. These studies demonstrated lower levels of circulating IgM (P <.001) and IgG (P =.078) antibodies to MUC1 in MM patients compared with HDs. Our data therefore show that in MM patients, sMUC1 levels are elevated and correlate with disease burden, whereas anti-MUC1 antibody levels are decreased.

Dealing with Multiple Solutions in Structural Vector Autoregressive Models.

PubMed

Beltz, Adriene M; Molenaar, Peter C M

2016-01-01

Structural vector autoregressive models (VARs) hold great potential for psychological science, particularly for time series data analysis. They capture the magnitude, direction of influence, and temporal (lagged and contemporaneous) nature of relations among variables. Unified structural equation modeling (uSEM) is an optimal structural VAR instantiation, according to large-scale simulation studies, and it is implemented within an SEM framework. However, little is known about the uniqueness of uSEM results. Thus, the goal of this study was to investigate whether multiple solutions result from uSEM analysis and, if so, to demonstrate ways to select an optimal solution. This was accomplished with two simulated data sets, an empirical data set concerning children's dyadic play, and modifications to the group iterative multiple model estimation (GIMME) program, which implements uSEMs with group- and individual-level relations in a data-driven manner. Results revealed multiple solutions when there were large contemporaneous relations among variables. Results also verified several ways to select the correct solution when the complete solution set was generated, such as the use of cross-validation, maximum standardized residuals, and information criteria. This work has immediate and direct implications for the analysis of time series data and for the inferences drawn from those data concerning human behavior.

Temporally diffeomorphic cardiac motion estimation from three-dimensional echocardiography by minimization of intensity consistency error.

PubMed

Zhang, Zhijun; Ashraf, Muhammad; Sahn, David J; Song, Xubo

2014-05-01

Quantitative analysis of cardiac motion is important for evaluation of heart function. Three dimensional (3D) echocardiography is among the most frequently used imaging modalities for motion estimation because it is convenient, real-time, low-cost, and nonionizing. However, motion estimation from 3D echocardiographic sequences is still a challenging problem due to low image quality and image corruption by noise and artifacts. The authors have developed a temporally diffeomorphic motion estimation approach in which the velocity field instead of the displacement field was optimized. The optimal velocity field optimizes a novel similarity function, which we call the intensity consistency error, defined as multiple consecutive frames evolving to each time point. The optimization problem is solved by using the steepest descent method. Experiments with simulated datasets, images of anex vivo rabbit phantom, images of in vivo open-chest pig hearts, and healthy human images were used to validate the authors' method. Simulated and real cardiac sequences tests showed that results in the authors' method are more accurate than other competing temporal diffeomorphic methods. Tests with sonomicrometry showed that the tracked crystal positions have good agreement with ground truth and the authors' method has higher accuracy than the temporal diffeomorphic free-form deformation (TDFFD) method. Validation with an open-access human cardiac dataset showed that the authors' method has smaller feature tracking errors than both TDFFD and frame-to-frame methods. The authors proposed a diffeomorphic motion estimation method with temporal smoothness by constraining the velocity field to have maximum local intensity consistency within multiple consecutive frames. The estimated motion using the authors' method has good temporal consistency and is more accurate than other temporally diffeomorphic motion estimation methods.

Waveform Optimization for Target Estimation by Cognitive Radar with Multiple Antennas.

PubMed

Yao, Yu; Zhao, Junhui; Wu, Lenan

2018-05-29

A new scheme based on Kalman filtering to optimize the waveforms of an adaptive multi-antenna radar system for target impulse response (TIR) estimation is presented. This work aims to improve the performance of TIR estimation by making use of the temporal correlation between successive received signals, and minimize the mean square error (MSE) of TIR estimation. The waveform design approach is based upon constant learning from the target feature at the receiver. Under the multiple antennas scenario, a dynamic feedback loop control system is established to real-time monitor the change in the target features extracted form received signals. The transmitter adapts its transmitted waveform to suit the time-invariant environment. Finally, the simulation results show that, as compared with the waveform design method based on the MAP criterion, the proposed waveform design algorithm is able to improve the performance of TIR estimation for extended targets with multiple iterations, and has a relatively lower level of complexity.

Detailed assessment of gene activation levels by multiple hypoxia-responsive elements under various hypoxic conditions.

PubMed

Takeuchi, Yasuto; Inubushi, Masayuki; Jin, Yong-Nan; Murai, Chika; Tsuji, Atsushi B; Hata, Hironobu; Kitagawa, Yoshimasa; Saga, Tsuneo

2014-12-01

HIF-1/HRE pathway is a promising target for the imaging and the treatment of intractable malignancy (HIF-1; hypoxia-inducible factor 1, HRE; hypoxia-responsive element). The purposes of our study are: (1) to assess the gene activation levels resulting from various numbers of HREs under various hypoxic conditions, (2) to evaluate the bidirectional activity of multiple HREs, and (3) to confirm whether multiple HREs can induce gene expression in vivo. Human colon carcinoma HCT116 cells were transiently transfected by the constructs containing a firefly luciferase reporter gene and various numbers (2, 4, 6, 8, 10, and 12) of HREs (nHRE+, nHRE-). The relative luciferase activities were measured under various durations of hypoxia (6, 12, 18, and 24 h), O2 concentrations (1, 2, 4, 8, and 16 %), and various concentrations of deferoxamine mesylate (20, 40, 80, 160, and 320 µg/mL growth medium). The bidirectional gene activation levels by HREs were examined in the constructs (dual-luc-nHREs) containing firefly and Renilla luciferase reporter genes at each side of nHREs. Finally, to test whether the construct containing 12HRE and the NIS reporter gene (12HRE-NIS) can induce gene expression in vivo, SPECT imaging was performed in a mouse xenograft model. (1) gene activation levels by HREs tended to increase with increasing HRE copy number, but a saturation effect was observed in constructs with more than 6 or 8 copies of an HRE, (2) gene activation levels by HREs increased remarkably during 6-12 h of hypoxia, but not beyond 12 h, (3) gene activation levels by HREs decreased with increasing O2 concentrations, but could be detected even under mild hypoxia at 16 % O2, (4) the bidirectionally proportional activity of the HRE was confirmed regardless of the hypoxic severity, and (5) NIS expression driven by 12 tandem copies of an HRE in response to hypoxia could be visualized on in vivo SPECT imaging. The results of this study will help in the understanding and assessment of

Temporal Trends in Population Level Impacts of Risk Factors for Sexually Transmitted Infections Among Men Who Have Sex with Men, Heterosexual Men, and Women: Disparities by Sexual Identity (1998-2013).

PubMed

Wand, Handan; Knight, Vickie; Lu, Heng; McNulty, Anna

2017-12-21

Sexually transmitted infections (STIs) remain a significant public health problem worldwide. We aimed to describe the temporal trends and relative contributions of established risk factors to STIs among sexual health center attendees. This retrospective study included more than 90,000 individuals who attended a sexual health center in Sydney, Australia, during the period 1998-2013. Multivariable logistic regression models were used to identify the correlates of STI diagnoses for three groups: men who have sex with men (MSM), heterosexual men, and women separately. Trends in population attributable risk percentages (PAR%) were estimated to assess the relative contributions of the risk factors on STI diagnosis. STI diagnosis rates among sexual health clinic attendees increased by 75% from 16 to 28% among MSM and more than doubled among heterosexual men and women (7-15 and 5-12%, respectively). Inconsistent condom use, three or more sex partners, sex overseas, past STI diagnosis, and contact with an STI case collectively contributed 61, 74 and 55% of the STI diagnoses among MSM, heterosexual men and women, respectively. Increase in STI diagnosis associated with temporal trends in combined risk factors including condomless sex, multiple sex partners, past STI diagnosis, and contact with an STI case. Although the majority of the factors considered in this study have been significantly associated with STI positivity in all three groups, their overall population level contributions to the epidemic have changed substantially. Our results indicated significant disparities between the MSM and heterosexual men and women as well as sex-specific differences in terms of sexual behaviors.

Evaluation of lithium serum level in multiple sclerosis patients: A neuroprotective element.

PubMed

Karimi, Atieh; Bahrampour, Kobra; Momeni Moghaddam, Mohammad Amin; Asadikaram, Gholamreza; Ebrahimi, Ghasem; Torkzadeh-Mahani, Masoud; Esmaeili Tarzi, Mojdeh; Nematollahi, Mohammad Hadi

2017-10-01

It has been claimed that continuous and high production of nitric oxide (NO) and its metabolites may be involved in the pathogenesis of several neurological disorders such as multiple sclerosis. A number of studies have demonstrated that lithium regulates NO levels in disorders of the central nervous system. The aim of this study was to investigate whether NO as a marker of disease activity is correlated with lithium deficiency in relapsing remitting multiple sclerosis (RR-MS). This case-controlled study comprised 44 patients with RR-MS and 43 healthy subjects matched by age, gender, smoking status, and body mass index. The Griess reaction was used to measure the NO metabolites, nitrite and nitrate in serum. In addition serum lithium levels were measured using atomic absorption spectrometry method. The mean serum NO concentrations in the groups RR-MS and the control were 18.5 ± 3.1µM and 15.5 ± 2.9µM, respectively. Data analysis showed a statistically significant difference between subjects with RR-MS and the control group (p < 0.05). Furthermore, serum lithium concentrations in RR-MS (0.57 ± 0.2) were remarkably lower in RR-MS patients than the controls (2.29 ± 0.7) (p < 0.05). The present findings suggest that lithium deficiency may upregulates NO production in RR-MS. Further studies with larger samples are needed to confirm the effects of lithium treatment on NO pathway and its association with synaptic plasticity in RR-MS patients. Copyright © 2017 Elsevier B.V. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna, E-mail: burger@biology.rutgers.edu

There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey)more » did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets.« less

Circumpolar spatio-temporal patterns and contributing climatic factors of wildfire activity in the Arctic tundra from 2001-2015

NASA Astrophysics Data System (ADS)

Masrur, Arif; Petrov, Andrey N.; DeGroote, John

2018-01-01

Recent years have seen an increased frequency of wildfire events in different parts of Arctic tundra ecosystems. Contemporary studies have largely attributed these wildfire events to the Arctic’s rapidly changing climate and increased atmospheric disturbances (i.e. thunderstorms). However, existing research has primarily examined the wildfire-climate dynamics of individual large wildfire events. No studies have investigated wildfire activity, including climatic drivers, for the entire tundra biome across multiple years, i.e. at the planetary scale. To address this limitation, this paper provides a planetary/circumpolar scale analyses of space-time patterns of tundra wildfire occurrence and climatic association in the Arctic over a 15 year period (2001-2015). In doing so, we have leveraged and analyzed NASA Terra’s MODIS active fire and MERRA climate reanalysis products at multiple temporal scales (decadal, seasonal and monthly). Our exploratory spatial data analysis found that tundra wildfire occurrence was spatially clustered and fire intensity was spatially autocorrelated across the Arctic regions. Most of the wildfire events occurred in the peak summer months (June-August). Our multi-temporal (decadal, seasonal and monthly) scale analyses provide further support to the link between climate variability and wildfire activity. Specifically, we found that warm and dry conditions in the late spring to mid-summer influenced tundra wildfire occurrence, spatio-temporal distribution, and fire intensity. Additionally, reduced average surface precipitation and soil moisture levels in the winter-spring period were associated with increased fire intensity in the following summer. These findings enrich contemporary knowledge on tundra wildfire’s spatial and seasonal patterns, and shed new light on tundra wildfire-climate relationships in the circumpolar context. Furthermore, this first pan-Arctic analysis provides a strong incentive and direction for future studies

Quantifying the effects of mountain pine beetle infestation on water and biogeochemical cycles at multiple spatial and temporal scales

NASA Astrophysics Data System (ADS)

Brooks, P. D.; Harpold, A. A.; Somor, A. J.; Troch, P. A.; Gochis, D. J.; Ewers, B. E.; Pendall, E.; Biederman, J. A.; Reed, D.; Barnard, H. R.; Whitehouse, F.; Aston, T.; Borkhuu, B.

2010-12-01

Unprecedented levels of bark beetle infestation over the last decade have radically altered forest structure across millions of hectares of Western U.S. montane environments. The widespread extent of this disturbance presents a major challenge for governments and resource managers who lack a predictive understanding of how water and biogeochemical cycles will respond to this disturbance over various temporal and spatial scales. There is a widespread perception, largely based on hydrological responses to fire or logging, that a reduction in both transpiration and interception following tree death will increase soil water availability and catchment water yield. However, few studies have directly addressed the effects of insect-induced forest decline on water and biogeochemical cycling. We address this knowledge gap using observations and modeling at scales from 100 to 109 m2 across study sites in CO and WY that vary in the intensity and timing of beetle infestation and tree death. Our focus on multiple sites with different levels of impact allows us to address two broad, organizing questions: How do changes in vegetation structure associated with MPB alter the partitioning of energy and water? And How do these changes in energy and water availability affect local to regional scale water and biogeochemical cycles? This presentation will focus primarily on energy balance and water partitioning, providing context for ongoing biogeochemical work. During the growing season, stand-scale transpiration declines rapidly and soil moisture increases following infestation, consistent with streamflow data from regional catchments that shows an increase in baseflow following widespread attack. During the winter and spring, stand scale snow surveys and continuous snow depth sensors suggested that the variability in snow cover decreased as the severity of beetle impact increases, but there were no significant stand-scale differences in snow depth among levels of impact. This is due

Cognitive Function and Heat Shock Protein 70 in Children With Temporal Lobe Epilepsy.

PubMed

Oraby, Azza M; Raouf, Ehab R Abdol; El-Saied, Mostafa M; Abou-Khadra, Maha K; Helal, Suzette I; Hashish, Adel F

2017-01-01

We conducted the present study to examine cognitive function and serum heat shock protein 70 levels among children with temporal lobe epilepsy. The Stanford-Binet Intelligence Test was carried out to examine cognitive function in 30 children with temporal lobe epilepsy and 30 controls. Serum heat shock protein 70 levels were determined with an enzyme-linked immunosorbent assay. The epilepsy group had significantly lower cognitive function testing scores and significantly higher serum heat shock protein 70 levels than the control group; there were significant negative correlations between serum heat shock protein 70 levels and short-term memory and composite scores. Children with uncontrolled seizures had significantly lower verbal reasoning scores and significantly higher serum heat shock protein 70 levels than children with controlled seizures. Children with temporal lobe epilepsy have cognitive dysfunction and elevated levels of serum heat shock protein 70, which may be considered a stress biomarker.

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

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.

Increased plasma/serum levels of prolactin in multiple sclerosis: a meta-analysis.

PubMed

Wei, Wei; Liu, Lei; Cheng, Zhong-Le; Hu, Bo

2017-08-01

Prolactin (PRL) is a polypeptide hormone that is known to stimulate humoral and cell mediated immune responses. PRL levels have been investigated in several autoimmune diseases including multiple sclerosis (MS); however, these have yielded different and inconsistent results. This study aims to perform a more precise evaluation on the plasma/serum PRL levels in MS patients, and to explore the available influential factors. Research related to plasma/serum PRL levels in MS patients and healthy controls were gathered using PubMed, EMBASE and The Cochrane Library database (until Mar 31 2016). Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analysis. Heterogeneity test was performed by the Q statistic and quantified using I 2 , and publication bias was evaluated using a funnel plot and Egger's linear regression test. 516 articles were obtained after searching databases, and 8 studies with 426 MS patients and 296 controls were finally included. Meta-analysis revealed that, compared with the control group, the MS group had significantly higher plasma/serum PRL levels, with the SMD of 0.55 and 95%CI (0.39, 0.72). Subgroup analyses showed that region, age and disease duration were associated with PRL level in MS patients. In summary, our meta-analysis revealed a significantly higher PRL level in MS patients than healthy controls, and it is influenced by region, age and disease duration.

Relativity theory and time perception: single or multiple clocks?

PubMed

Buhusi, Catalin V; Meck, Warren H

2009-07-22

Current theories of interval timing assume that humans and other animals time as if using a single, absolute stopwatch that can be stopped or reset on command. Here we evaluate the alternative view that psychological time is represented by multiple clocks, and that these clocks create separate temporal contexts by which duration is judged in a relative manner. Two predictions of the multiple-clock hypothesis were tested. First, that the multiple clocks can be manipulated (stopped and/or reset) independently. Second, that an event of a given physical duration would be perceived as having different durations in different temporal contexts, i.e., would be judged differently by each clock. Rats were trained to time three durations (e.g., 10, 30, and 90 s). When timing was interrupted by an unexpected gap in the signal, rats reset the clock used to time the "short" duration, stopped the "medium" duration clock, and continued to run the "long" duration clock. When the duration of the gap was manipulated, the rats reset these clocks in a hierarchical order, first the "short", then the "medium", and finally the "long" clock. Quantitative modeling assuming re-allocation of cognitive resources in proportion to the relative duration of the gap to the multiple, simultaneously timed event durations was used to account for the results. These results indicate that the three event durations were effectively timed by separate clocks operated independently, and that the same gap duration was judged relative to these three temporal contexts. Results suggest that the brain processes the duration of an event in a manner similar to Einstein's special relativity theory: A given time interval is registered differently by independent clocks dependent upon the context.

Fuzzy branching temporal logic.

PubMed

Moon, Seong-ick; Lee, Kwang H; Lee, Doheon

2004-04-01

Intelligent systems require a systematic way to represent and handle temporal information containing uncertainty. In particular, a logical framework is needed that can represent uncertain temporal information and its relationships with logical formulae. Fuzzy linear temporal logic (FLTL), a generalization of propositional linear temporal logic (PLTL) with fuzzy temporal events and fuzzy temporal states defined on a linear time model, was previously proposed for this purpose. However, many systems are best represented by branching time models in which each state can have more than one possible future path. In this paper, fuzzy branching temporal logic (FBTL) is proposed to address this problem. FBTL adopts and generalizes concurrent tree logic (CTL*), which is a classical branching temporal logic. The temporal model of FBTL is capable of representing fuzzy temporal events and fuzzy temporal states, and the order relation among them is represented as a directed graph. The utility of FBTL is demonstrated using a fuzzy job shop scheduling problem as an example.

Spatial and temporal ecology of eastern spadefoot toads on a Florida landscape

Treesearch

Cathryn H. Greenberg; George W. Tanner

2005-01-01

Effective amphibian conservation must consider population and landscape processes, but information at multiple scales is rare. We explore spatial and temporal patterns of breeding and recruitment by eastern spadefoot toads (Scaphiopus holbrookii), using nine years of data from continuous monitoring with drift fences and pitfall traps at eight...

Deficits in Visuo-Motor Temporal Integration Impacts Manual Dexterity in Probable Developmental Coordination Disorder

PubMed Central

Nobusako, Satoshi; Sakai, Ayami; Tsujimoto, Taeko; Shuto, Takashi; Nishi, Yuki; Asano, Daiki; Furukawa, Emi; Zama, Takuro; Osumi, Michihiro; Shimada, Sotaro; Morioka, Shu; Nakai, Akio

2018-01-01

The neurological basis of developmental coordination disorder (DCD) is thought to be deficits in the internal model and mirror-neuron system (MNS) in the parietal lobe and cerebellum. However, it is not clear if the visuo-motor temporal integration in the internal model and automatic-imitation function in the MNS differs between children with DCD and those with typical development (TD). The current study aimed to investigate these differences. Using the manual dexterity test of the Movement Assessment Battery for Children (second edition), the participants were either assigned to the probable DCD (pDCD) group or TD group. The former was comprised of 29 children with clumsy manual dexterity, while the latter consisted of 42 children with normal manual dexterity. Visuo-motor temporal integration ability and automatic-imitation function were measured using the delayed visual feedback detection task and motor interference task, respectively. Further, the current study investigated whether autism-spectrum disorder (ASD) traits, attention-deficit hyperactivity disorder (ADHD) traits, and depressive symptoms differed among the two groups, since these symptoms are frequent comorbidities of DCD. In addition, correlation and multiple regression analyses were performed to extract factors affecting clumsy manual dexterity. In the results, the delay-detection threshold (DDT) and steepness of the delay-detection probability curve, which indicated visuo-motor temporal integration ability, were significantly prolonged and decreased, respectively, in children with pDCD. The interference effect, which indicated automatic-imitation function, was also significantly reduced in this group. These results highlighted that children with clumsy manual dexterity have deficits in visuo-motor temporal integration and automatic-imitation function. There was a significant correlation between manual dexterity, and measures of visuo-motor temporal integration, and ASD traits and ADHD traits and

Deficits in Visuo-Motor Temporal Integration Impacts Manual Dexterity in Probable Developmental Coordination Disorder.

PubMed

Nobusako, Satoshi; Sakai, Ayami; Tsujimoto, Taeko; Shuto, Takashi; Nishi, Yuki; Asano, Daiki; Furukawa, Emi; Zama, Takuro; Osumi, Michihiro; Shimada, Sotaro; Morioka, Shu; Nakai, Akio

2018-01-01

The neurological basis of developmental coordination disorder (DCD) is thought to be deficits in the internal model and mirror-neuron system (MNS) in the parietal lobe and cerebellum. However, it is not clear if the visuo-motor temporal integration in the internal model and automatic-imitation function in the MNS differs between children with DCD and those with typical development (TD). The current study aimed to investigate these differences. Using the manual dexterity test of the Movement Assessment Battery for Children (second edition), the participants were either assigned to the probable DCD (pDCD) group or TD group. The former was comprised of 29 children with clumsy manual dexterity, while the latter consisted of 42 children with normal manual dexterity. Visuo-motor temporal integration ability and automatic-imitation function were measured using the delayed visual feedback detection task and motor interference task, respectively. Further, the current study investigated whether autism-spectrum disorder (ASD) traits, attention-deficit hyperactivity disorder (ADHD) traits, and depressive symptoms differed among the two groups, since these symptoms are frequent comorbidities of DCD. In addition, correlation and multiple regression analyses were performed to extract factors affecting clumsy manual dexterity. In the results, the delay-detection threshold (DDT) and steepness of the delay-detection probability curve, which indicated visuo-motor temporal integration ability, were significantly prolonged and decreased, respectively, in children with pDCD. The interference effect, which indicated automatic-imitation function, was also significantly reduced in this group. These results highlighted that children with clumsy manual dexterity have deficits in visuo-motor temporal integration and automatic-imitation function. There was a significant correlation between manual dexterity, and measures of visuo-motor temporal integration, and ASD traits and ADHD traits and

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

Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland

PubMed Central

Spotswood, Erica N.; Bartolome, James W.; Allen-Diaz, Barbara

2015-01-01

Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery. PMID:26222069

Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

PubMed

Spotswood, Erica N; Bartolome, James W; Allen-Diaz, Barbara

2015-01-01

Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

Spatial pattern of reference evapotranspiration change and its temporal evolution over Southwest China

NASA Astrophysics Data System (ADS)

Sun, Shanlei; Wang, Guojie; Huang, Jin; Mu, Mengyuan; Yan, Guixia; Liu, Chunwei; Gao, Chujie; Li, Xing; Yin, Yixing; Zhang, Fangmin; Zhu, Siguang; Hua, Wenjian

2017-11-01

Due to the close relationship of climate change with reference evapotranspiration (ETo), detecting changes in ETo spatial distribution and its temporal evolution at local and regional levels is favorable to comprehensively understand climate change-induced impacts on hydrology and agriculture. In this study, the objective is to identify whether climate change has caused variation of ETo spatial distribution in different analysis periods [i.e., long- (20-year), medium- (10-year), and short-term (5-year)] and to investigate its temporal evolution (namely, when these changes happened) at annual and monthly scales in Southwest China (SWC). First, we estimated ETo values using the United Nations Food and Agriculture Organization (FAO) Penman-Monteith equation, based on historical climate data measured at 269 weather sites during 1973-2012. The analysis of variance (ANOVA) results indicated that the spatial pattern of annual ETo had significantly changed during the past 40 years, particularly in west SWC for the long-term analysis period, and west and southeast SWC in both medium- and short-term periods, which corresponded to the percent area of significant differences which were 21.9, 58.0, and 48.2 %, respectively. For investigating temporal evolution of spatial patterns of annual ETo, Duncan's multiple range test was used, and we found that the most significant changes appeared during 1988-2002 with the significant area of higher than 25.0 %. In addition, for long-, medium-, and short-term analysis periods, the spatial distribution has significantly changed during March, September, November, and December, especially in the corresponding periods of 1988-1997, 1983-1992, 1973-1977, and 1988-2002. All in all, climate change has resulted in significant ETo changes in SWC since the 1970s. Knowledge of climate change-induced spatial distribution of ETo and its temporal evolution would aid in formulating strategies for water resources and agricultural managements.

Estimating uncertainty and its temporal variation related to global climate models in quantifying climate change impacts on hydrology

NASA Astrophysics Data System (ADS)

Shen, Mingxi; Chen, Jie; Zhuan, Meijia; Chen, Hua; Xu, Chong-Yu; Xiong, Lihua

2018-01-01

level, but their temporal variation could be well modeled by using the fourth-order polynomial. Overall, this study further emphasized the importance of using multiple GCMs for studying climate change impacts on hydrology. Furthermore, the temporal variation of uncertainty sourced from GCMs should be given more attention.

High-throughput amplicon sequencing and stream benthic bacteria: identifying the best taxonomic level for multiple-stressor research

PubMed Central

Salis, R. K.; Bruder, A.; Piggott, J. J.; Summerfield, T. C.; Matthaei, C. D.

2017-01-01

Disentangling the individual and interactive effects of multiple stressors on microbial communities is a key challenge to our understanding and management of ecosystems. Advances in molecular techniques allow studying microbial communities in situ and with high taxonomic resolution. However, the taxonomic level which provides the best trade-off between our ability to detect multiple-stressor effects versus the goal of studying entire communities remains unknown. We used outdoor mesocosms simulating small streams to investigate the effects of four agricultural stressors (nutrient enrichment, the nitrification inhibitor dicyandiamide (DCD), fine sediment and flow velocity reduction) on stream bacteria (phyla, orders, genera, and species represented by Operational Taxonomic Units with 97% sequence similarity). Community composition was assessed using amplicon sequencing (16S rRNA gene, V3-V4 region). DCD was the most pervasive stressor, affecting evenness and most abundant taxa, followed by sediment and flow velocity. Stressor pervasiveness was similar across taxonomic levels and lower levels did not perform better in detecting stressor effects. Community coverage decreased from 96% of all sequences for abundant phyla to 28% for species. Order-level responses were generally representative of responses of corresponding genera and species, suggesting that this level may represent the best compromise between stressor sensitivity and coverage of bacterial communities. PMID:28327636

Attention Deficit Hyperactivity Disorder (ADHD): Controversy, Developmental Mechanisms, and Multiple Levels of Analysis.

PubMed

Hinshaw, Stephen P

2018-05-07

Controversy abounds regarding the symptom dimensions of attention problems, impulsivity, and hyperactivity, developmentally extreme and impairing levels of which compose the diagnostic category of attention deficit hyperactivity disorder (ADHD). I highlight causal factors, underlying mechanisms, developmental trajectories, and female manifestations of ADHD, integrating the psychobiological underpinnings of this syndrome with contextual factors related to its clinical presentation, impairments, and soaring increases in diagnosed prevalence. Indeed, despite strong heritability, ADHD is expressed via transactional patterns of influence linked to family-, school-, peer-, neighborhood-, and policy-related factors. Moreover, intervention strategies must take into account both pharmacologic and behavioral modalities if the goal is to enhance competencies, rather than symptom reduction per se. A comprehensive understanding of ADHD mandates multiple levels of analysis-spanning genes, neurotransmission, brain pathways, individual skill levels, family socialization, peer relationships, and educational and cultural forces-which must be integrated and synthesized to surpass reductionist accounts, reduce stigma, and maximize the impact of prevention- and intervention-related efforts.

The temporal interplay of self-esteem instability and affective instability in borderline personality disorder patients' everyday lives.

PubMed

Santangelo, Philip S; Reinhard, Iris; Koudela-Hamila, Susanne; Bohus, Martin; Holtmann, Jana; Eid, Michael; Ebner-Priemer, Ulrich W

2017-11-01

Borderline personality disorder (BPD) is defined by a pervasive pattern of instability. Although there is ample empirical evidence that unstable self-esteem is associated with a myriad of BPD-like symptoms, self-esteem instability and its temporal dynamics have received little empirical attention in patients with BPD. Even worse, the temporal interplay of affective instability and self-esteem instability has been neglected completely, although it has been hypothesized recently that the lack of specificity of affective instability in association with BPD might be explained by the highly intertwined temporal relationship between affective and self-esteem instability. To investigate self-esteem instability, its temporal interplay with affective instability, and its association with psychopathology, 60 patients with BPD and 60 healthy controls (HCs) completed electronic diaries for 4 consecutive days during their everyday lives. Participants reported their current self-esteem, valence, and tense arousal levels 12 times a day in approximately one-hr intervals. We used multiple state-of-the-art statistical techniques and graphical approaches to reveal patterns of instability, clarify group differences, and examine the temporal interplay of self-esteem instability and affective instability. As hypothesized, instability in both self-esteem and affect was clearly elevated in the patients with BPD. In addition, self-esteem instability and affective instability were highly correlated. Both types of instability were related to general psychopathology. Because self-esteem instability could not fully explain affective instability and vice versa and neither affective instability nor self-esteem instability was able to explain psychopathology completely, our findings suggest that these types of instability represent unique facets of BPD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Spatio-temporal dynamics of species richness in coastal fish communities

USGS Publications Warehouse

Lekve, K.; Boulinier, T.; Stenseth, N.C.; Gjøsaeter, J.; Fromentin, J-M.; Hines, J.E.; Nichols, J.D.

2002-01-01

Determining patterns of change in species richness and the processes underlying the dynamics of biodiversity are of key interest within the field of ecology, but few studies have investigated the dynamics of vertebrate communities at a decadal temporal scale. Here, we report findings on the spado-temporal variability in the richness and composition of fish communities along the Norwegian Skagerrak coast having been surveyed for more than half a century. Using statistical models incorporating non-detection and associated sampling variance, we estimate local species richness and changes in species composition allowing us to compute temporal variability in species richness. We tested whether temporal variation could be related to distance to the open sea and to local levels of pollution. Clear differences in mean species richness and temporal variability are observed between fjords that were and were not exposed to the effects of pollution. Altogether this indicates that the fjord is an appropriate scale for studying changes in coastal fish communities in space and time. The year-to-year rates of local extinction and turnover were found to be smaller than spatial differences in community composition. At the regional level, exposure to the open sea plays a homogenizing role, possibly due to coastal currents and advection.

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…

Prediction of pediatric unipolar depression using multiple neuromorphometric measurements: a pattern classification approach.

PubMed

Wu, Mon-Ju; Wu, Hanjing Emily; Mwangi, Benson; Sanches, Marsal; Selvaraj, Sudhakar; Zunta-Soares, Giovana B; Soares, Jair C

2015-03-01

Diagnosis of pediatric neuropsychiatric disorders such as unipolar depression is largely based on clinical judgment - without objective biomarkers to guide diagnostic process and subsequent therapeutic interventions. Neuroimaging studies have previously reported average group-level neuroanatomical differences between patients with pediatric unipolar depression and healthy controls. In the present study, we investigated the utility of multiple neuromorphometric indices in distinguishing pediatric unipolar depression patients from healthy controls at an individual subject level. We acquired structural T1-weighted scans from 25 pediatric unipolar depression patients and 26 demographically matched healthy controls. Multiple neuromorphometric indices such as cortical thickness, volume, and cortical folding patterns were obtained. A support vector machine pattern classification model was 'trained' to distinguish individual subjects with pediatric unipolar depression from healthy controls based on multiple neuromorphometric indices and model predictive validity (sensitivity and specificity) calculated. The model correctly identified 40 out of 51 subjects translating to 78.4% accuracy, 76.0% sensitivity and 80.8% specificity, chi-square p-value = 0.000049. Volumetric and cortical folding abnormalities in the right thalamus and right temporal pole respectively were most central in distinguishing individual patients with pediatric unipolar depression from healthy controls. These findings provide evidence that a support vector machine pattern classification model using multiple neuromorphometric indices may qualify as diagnostic marker for pediatric unipolar depression. In addition, our results identified the most relevant neuromorphometric features in distinguishing PUD patients from healthy controls. Copyright © 2015 Elsevier Ltd. All rights reserved.

Temporal Resolution Needed for Auditory Communication: Measurement With Mosaic Speech

PubMed Central

Nakajima, Yoshitaka; Matsuda, Mizuki; Ueda, Kazuo; Remijn, Gerard B.

2018-01-01

Temporal resolution needed for Japanese speech communication was measured. A new experimental paradigm that can reflect the spectro-temporal resolution necessary for healthy listeners to perceive speech is introduced. As a first step, we report listeners' intelligibility scores of Japanese speech with a systematically degraded temporal resolution, so-called “mosaic speech”: speech mosaicized in the coordinates of time and frequency. The results of two experiments show that mosaic speech cut into short static segments was almost perfectly intelligible with a temporal resolution of 40 ms or finer. Intelligibility dropped for a temporal resolution of 80 ms, but was still around 50%-correct level. The data are in line with previous results showing that speech signals separated into short temporal segments of <100 ms can be remarkably robust in terms of linguistic-content perception against drastic manipulations in each segment, such as partial signal omission or temporal reversal. The human perceptual system thus can extract meaning from unexpectedly rough temporal information in speech. The process resembles that of the visual system stringing together static movie frames of ~40 ms into vivid motion. PMID:29740295

SwarmSight: Measuring the Temporal Progression of Animal Group Activity Levels from Natural Scene and Laboratory Videos

PubMed Central

Birgiolas, Justas; Jernigan, Christopher M.; Smith, Brian H.; Crook, Sharon M.

2016-01-01

We describe SwarmSight (available at: https://github.com/justasb/SwarmSight), a novel, open-source, Microsoft Windows software tool for quantitative assessment of the temporal progression of animal group activity levels from recorded videos. The tool utilizes a background subtraction machine vision algorithm and provides an activity metric that can be used to quantitatively assess and compare animal group behavior. Here we demonstrate the tool utility by analyzing defensive bee behavior as modulated by alarm pheromones, wild bird feeding onset and interruption, and cockroach nest finding activity. While more sophisticated, commercial software packages are available, SwarmSight provides a low-cost, open-source, and easy-to-use alternative that is suitable for a wide range of users, including minimally trained research technicians and behavioral science undergraduate students in classroom laboratory settings. PMID:27130170

A Plastic Temporal Brain Code for Conscious State Generation

PubMed Central

Dresp-Langley, Birgitta; Durup, Jean

2009-01-01

Consciousness is known to be limited in processing capacity and often described in terms of a unique processing stream across a single dimension: time. In this paper, we discuss a purely temporal pattern code, functionally decoupled from spatial signals, for conscious state generation in the brain. Arguments in favour of such a code include Dehaene et al.'s long-distance reverberation postulate, Ramachandran's remapping hypothesis, evidence for a temporal coherence index and coincidence detectors, and Grossberg's Adaptive Resonance Theory. A time-bin resonance model is developed, where temporal signatures of conscious states are generated on the basis of signal reverberation across large distances in highly plastic neural circuits. The temporal signatures are delivered by neural activity patterns which, beyond a certain statistical threshold, activate, maintain, and terminate a conscious brain state like a bar code would activate, maintain, or inactivate the electronic locks of a safe. Such temporal resonance would reflect a higher level of neural processing, independent from sensorial or perceptual brain mechanisms. PMID:19644552

Spatio-temporal Organization During Ventricular Fibrillation in the Human Heart.

PubMed

Robson, Jinny; Aram, Parham; Nash, Martyn P; Bradley, Chris P; Hayward, Martin; Paterson, David J; Taggart, Peter; Clayton, Richard H; Kadirkamanathan, Visakan

2018-06-01

In this paper, we present a novel approach to quantify the spatio-temporal organization of electrical activation during human ventricular fibrillation (VF). We propose three different methods based on correlation analysis, graph theoretical measures and hierarchical clustering. Using the proposed approach, we quantified the level of spatio-temporal organization during three episodes of VF in ten patients, recorded using multi-electrode epicardial recordings with 30 s coronary perfusion, 150 s global myocardial ischaemia and 30 s reflow. Our findings show a steady decline in spatio-temporal organization from the onset of VF with coronary perfusion. We observed transient increases in spatio-temporal organization during global myocardial ischaemia. However, the decline in spatio-temporal organization continued during reflow. Our results were consistent across all patients, and were consistent with the numbers of phase singularities. Our findings show that the complex spatio-temporal patterns can be studied using complex network analysis.

The associations between multisensory temporal processing and symptoms of schizophrenia.

PubMed

Stevenson, Ryan A; Park, Sohee; Cochran, Channing; McIntosh, Lindsey G; Noel, Jean-Paul; Barense, Morgan D; Ferber, Susanne; Wallace, Mark T

2017-01-01

Recent neurobiological accounts of schizophrenia have included an emphasis on changes in sensory processing. These sensory and perceptual deficits can have a cascading effect onto higher-level cognitive processes and clinical symptoms. One form of sensory dysfunction that has been consistently observed in schizophrenia is altered temporal processing. In this study, we investigated temporal processing within and across the auditory and visual modalities in individuals with schizophrenia (SCZ) and age-matched healthy controls. Individuals with SCZ showed auditory and visual temporal processing abnormalities, as well as multisensory temporal processing dysfunction that extended beyond that attributable to unisensory processing dysfunction. Most importantly, these multisensory temporal deficits were associated with the severity of hallucinations. This link between atypical multisensory temporal perception and clinical symptomatology suggests that clinical symptoms of schizophrenia may be at least partly a result of cascading effects from (multi)sensory disturbances. These results are discussed in terms of underlying neural bases and the possible implications for remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

Temporal Ventriloquism Reveals Intact Audiovisual Temporal Integration in Amblyopia.

PubMed

Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F

2018-02-01

We have shown previously that amblyopia involves impaired detection of asynchrony between auditory and visual events. To distinguish whether this impairment represents a defect in temporal integration or nonintegrative multisensory processing (e.g., cross-modal matching), we used the temporal ventriloquism effect in which visual temporal order judgment (TOJ) is normally enhanced by a lagging auditory click. Participants with amblyopia (n = 9) and normally sighted controls (n = 9) performed a visual TOJ task. Pairs of clicks accompanied the two lights such that the first click preceded the first light, or second click lagged the second light by 100, 200, or 450 ms. Baseline audiovisual synchrony and visual-only conditions also were tested. Within both groups, just noticeable differences for the visual TOJ task were significantly reduced compared with baseline in the 100- and 200-ms click lag conditions. Within the amblyopia group, poorer stereo acuity and poorer visual acuity in the amblyopic eye were significantly associated with greater enhancement in visual TOJ performance in the 200-ms click lag condition. Audiovisual temporal integration is intact in amblyopia, as indicated by perceptual enhancement in the temporal ventriloquism effect. Furthermore, poorer stereo acuity and poorer visual acuity in the amblyopic eye are associated with a widened temporal binding window for the effect. These findings suggest that previously reported abnormalities in audiovisual multisensory processing may result from impaired cross-modal matching rather than a diminished capacity for temporal audiovisual integration.

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

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

PubMed Central

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

2015-01-01

The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979–2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (P f) and structural connectivity (P ff), 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 P f vs. P ff mean values and were compared across spatial extents. The distributions of P f 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 P f’s variability along with the increment of the mean slope of the P f ‘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

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

Effects of education level and employment status on HRQoL in early relapsing-remitting multiple sclerosis.

PubMed

Patti, F; Pozzilli, C; Montanari, E; Pappalardo, A; Piazza, L; Levi, A; Onesti, E; Pesci, I

2007-07-01

To evaluate the effects of education level and employment status on health-related quality of life (HRQoL) in a large cohort of patients affected by relapsing-remitting multiple sclerosis (RRMS). Patients This study included 648 patients with RRMS attending 40 Italian MS centers. Inclusion criteria were an Expanded Disability Status Scale (EDSS) score between 1.0 and 5.5; stable disease on enrollment; and no previous treatment with interferons, glatiramer acetate, or immunosuppressive drugs. Quality of life (QoL) was evaluated by the Multiple Sclerosis Quality of Life-54 questionnaire (MSQoL-54). Employed patients scored significantly higher than other patient groups in the majority of MSQoL-54 domains. Similarly, patients with academic degrees and secondary education had higher scores than those with primary education (ie, eight years of education) in several domains of HRQoL. Patients who were employed with a high educational level achieved significantly better scores than unemployed patients with a lower educational level. In multivariate analysis, occupation and educational level were found to be significant and independent predictors of HRQoL. The results of our study suggest the importance of sustaining employment after a recent diagnosis of MS. In addition, education has a great influence on HRQoL; a higher education level may determine a stronger awareness of the disease, and a better ability to cope with the challenges of a chronic disease such as MS.

Disease and community structure: white-nose syndrome alters spatial and temporal niche partitioning in sympatric bat species

USGS Publications Warehouse

Jachowski, David S.; Dobony, Christopher A.; Coleman, Laci S.; Ford, W. Mark; Britzke, Eric R.; Rodrigue, Jane L.

2014-01-01

AimEmerging infectious diseases present a major perturbation with apparent direct effects such as reduced population density, extirpation and/or extinction. Comparatively less is known about the potential indirect effects of disease that likely alter community structure and larger ecosystem function. Since 2006, white-nose syndrome (WNS) has resulted in the loss of over 6 million hibernating bats in eastern North America. Considerable evidence exists concerning niche partitioning in sympatric bat species in this region, and the unprecedented, rapid decline in multiple species following WNS may provide an opportunity to observe a dramatic restructuring of the bat community.LocationWe conducted our study at Fort Drum Army Installation in Jefferson and Lewis counties, New York, USA, where WNS first impacted extant bat species in winter 2007–2008.MethodsAcoustical monitoring during 2003–2011 allowed us to test the hypothesis that spatial and temporal niche partitioning by bats was relaxed post-WNS.ResultsWe detected nine bat species pre- and post-WNS. Activity for most bat species declined post-WNS. Dramatic post-WNS declines in activity of little brown bat (Myotis lucifugus, MYLU), formerly the most abundant bat species in the region, were associated with complex, often species-specific responses by other species that generally favoured increased spatial and temporal overlap with MYLU.Main conclusionsIn addition to the obvious direct effects of disease on bat populations and activity levels, our results provide evidence that disease can have cascading indirect effects on community structure. Recent occurrence of WNS in North America, combined with multiple existing stressors, is resulting in dramatic shifts in temporal and spatial niche partitioning within bat communities. These changes might influence long-term population viability of some bat species as well as broader scale ecosystem structure and function.

Dopamine D2 receptor levels in striatum, thalamus, substantia nigra, limbic regions, and cortex in schizophrenic subjects.

PubMed

Kessler, Robert M; Woodward, Neil D; Riccardi, Patrizia; Li, Rui; Ansari, M Sib; Anderson, Sharlett; Dawant, Benoit; Zald, David; Meltzer, Herbert Y

2009-06-15

Studies in schizophrenic patients have reported dopaminergic abnormalities in striatum, substantia nigra, thalamus, anterior cingulate, hippocampus, and cortex that have been related to positive symptoms and cognitive impairments. [(18)F]fallypride positron emission tomography studies were performed in off-medication or never-medicated schizophrenic subjects (n = 11, 6 men, 5 women; mean age of 30.5 +/- 8.0 [SD] years; 4 drug-naive) and age-matched healthy subjects (n = 11, 5 men, 6 women, mean age of 31.6 +/- 9.2 [SD]) to examine dopamine D(2) receptor (DA D(2)r) levels in the caudate, putamen, ventral striatum, medial thalamus, posterior thalamus, substantia nigra, amygdala, temporal cortex, anterior cingulate, and hippocampus. In schizophrenic subjects, increased DA D(2)r levels were seen in the substantia nigra bilaterally; decreased levels were seen in the left medial thalamus. Correlations of symptoms with ROI data demonstrated a significant correlation of disorganized thinking/nonparanoid delusions with the right temporal cortex ROI (r = .94, p = .0001), which remained significant after correction for multiple comparisons (p < .03). Correlations of symptoms with parametric images of DA D(2)r levels revealed no significant clusters of correlations with negative symptoms but significant clusters of positive correlations of total positive symptoms, delusions and bizarre behavior with the lateral and anterior temporal cortex, and hallucinations with the left ventral striatum. The results of this study demonstrate abnormal DA D(2)r-mediated neurotransmission in the substantia nigra consistent with nigral dysfunction in schizophrenia and suggest that both temporal cortical and ventral striatal DA D(2)r mediate positive symptoms.

Structured Multi-level Data Fusion and Modelling of Heterogeneous Environmental Data for Future Internet Applications

NASA Astrophysics Data System (ADS)

Sabeur, Zoheir; Chakravarthy, Ajay; Bashevoy, Maxim; Modafferi, Stefano

2013-04-01

The rapid increase in environmental observations which are conducted by Small to Medium Enterprise communities and volunteers using affordable in situ sensors at various scales, in addition to the more established observatories set up by environmental and space agencies using airborne and space-borne sensing technologies is generating serious amounts of BIG data at ever increasing speeds. Furthermore, the emergence of Future Internet technologies and the urgent requirements for the deployment of specific enablers for the delivery of processed environmental knowledge in real-time with advanced situation awareness to citizens has reached paramount importance. Specifically, it has become highly critical now to build and provide services which automate the aggregation of data from various sources, while surmounting the semantic gaps, conflicts and heterogeneity in data sources. The early stage aggregation of data will enable the pre-processing of data from multiple sources while reconciling the temporal gaps in measurement time series, and aligning their respective a-synchronicities. This low level type of data fusion process needs to be automated and chained to more advanced level of data fusion services specialising in observation forecasts at spaces where sensing is not deployed; or at time slices where sensing has not taken place yet. As a result, multi-level fusion services are required among the families of specific enablers for monitoring environments and spaces in the Future Internet. These have been intially deployed and piloted in the ongoing ENVIROFI project of the FI-PPP programme [1]. Automated fusion and modelling of in situ and remote sensing data has been set up and the experimentation successfully conducted using RBF networks for the spatial fusion of water quality parameters measurements from satellite and stationary buoys in the Irish Sea. The RBF networks method scales for the spatial data fusion of multiple types of observation sources. This

Assessment of skills using a virtual reality temporal bone surgery simulator.

PubMed

Linke, R; Leichtle, A; Sheikh, F; Schmidt, C; Frenzel, H; Graefe, H; Wollenberg, B; Meyer, J E

2013-08-01

Surgery on the temporal bone is technically challenging due to its complex anatomy. Precise anatomical dissection of the human temporal bone is essential and is fundamental for middle ear surgery. We assessed the possible application of a virtual reality temporal bone surgery simulator to the education of ear surgeons. Seventeen ENT physicians with different levels of surgical training and 20 medical students performed an antrotomy with a computer-based virtual temporal bone surgery simulator. The ease, accuracy and timing of the simulated temporal bone surgery were assessed using the automatic assessment software provided by the simulator device and additionally with a modified Final Product Analysis Scale. Trained ENT surgeons, physicians without temporal bone surgical training and medical students were all able to perform the antrotomy. However, the highly trained ENT surgeons were able to complete the surgery in approximately half the time, with better handling and accuracy as assessed by the significant reduction in injury to important middle ear structures. Trained ENT surgeons achieved significantly higher scores using both dissection analysis methods. Surprisingly, there were no significant differences in the results between medical students and physicians without experience in ear surgery. The virtual temporal bone training system can stratify users of known levels of experience. This system can be used not only to improve the surgical skills of trained ENT surgeons for more successful and injury-free surgeries, but also to train inexperienced physicians/medical students in developing their surgical skills for the ear.

Temporal and spatial resolution required for imaging myocardial function

NASA Astrophysics Data System (ADS)

Eusemann, Christian D.; Robb, Richard A.

2004-05-01

4-D functional analysis of myocardial mechanics is an area of significant interest and research in cardiology and vascular/interventional radiology. Current multidimensional analysis is limited by insufficient temporal resolution of x-ray and magnetic resonance based techniques, but recent improvements in system design holds hope for faster and higher resolution scans to improve images of moving structures allowing more accurate functional studies, such as in the heart. This paper provides a basis for the requisite temporal and spatial resolution for useful imaging during individual segments of the cardiac cycle. Multiple sample rates during systole and diastole are compared to determine an adequate sample frequency to reduce regional myocardial tracking errors. Concurrently, out-of-plane resolution has to be sufficiently high to minimize partial volume effect. Temporal resolution and out-of-plane spatial resolution are related factors that must be considered together. The data used for this study is a DSR dynamic volume image dataset with high temporal and spatial resolution using implanted fiducial markers to track myocardial motion. The results of this study suggest a reduced exposure and scan time for x-ray and magnetic resonance imaging methods, since a lower sample rate during systole is sufficient, whereas the period of rapid filling during diastole requires higher sampling. This could potentially reduce the cost of these procedures and allow higher patient throughput.

Allometric and temporal scaling of movement characteristics in Galapagos tortoises

USGS Publications Warehouse

Bastille-Rousseau, Guillaume; Yackulic, Charles B.; Frair, Jacqueline L.; Cabrera, Freddy; Blake, Stephen

2016-01-01

Understanding how individual movement scales with body size is of fundamental importance in predicting ecological relationships for diverse species. One-dimensional movement metrics scale consistently with body size yet vary over different temporal scales. Knowing how temporal scale influences the relationship between animal body size and movement would better inform hypotheses about the efficiency of foraging behaviour, the ontogeny of energy budgets, and numerous life-history trade-offs.We investigated how the temporal scaling of allometric patterns in movement varies over the course of a year, specifically during periods of motivated (directional and fast movement) and unmotivated (stationary and tortuous movement) behaviour. We focused on a recently diverged group of species that displays wide variation in movement behaviour – giant Galapagos tortoises (Chelonoidis spp.) – to test how movement metrics estimated on a monthly basis scaled with body size.We used state-space modelling to estimate seven different movement metrics of Galapagos tortoises. We used log-log regression of the power law to evaluate allometric scaling for these movement metrics and contrasted relationships by species and sex.Allometric scaling of movement was more apparent during motivated periods of movement. During this period, allometry was revealed at multiple temporal intervals (hourly, daily and monthly), with values observed at daily and monthly intervals corresponding most closely to the expected one-fourth scaling coefficient, albeit with wide credible intervals. We further detected differences in the magnitude of scaling among taxa uncoupled from observed differences in the temporal structuring of their movement rates.Our results indicate that the definition of temporal scales is fundamental to the detection of allometry of movement and should be given more attention in movement studies. Our approach not only provides new conceptual insights into temporal attributes in one

Temporal Ventriloquism in a Purely Temporal Context

ERIC Educational Resources Information Center

Hartcher-O'Brien, Jessica; Alais, David

2011-01-01

This study examines how audiovisual signals are combined in time for a temporal analogue of the ventriloquist effect in a purely temporal context, that is, no spatial grounding of signals or other spatial facilitation. Observers were presented with two successive intervals, each defined by a 1250-ms tone, and indicated in which interval a brief…

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

Temporal abstraction and inductive logic programming for arrhythmia recognition from electrocardiograms.

PubMed

Carrault, G; Cordier, M-O; Quiniou, R; Wang, F

2003-07-01

This paper proposes a novel approach to cardiac arrhythmia recognition from electrocardiograms (ECGs). ECGs record the electrical activity of the heart and are used to diagnose many heart disorders. The numerical ECG is first temporally abstracted into series of time-stamped events. Temporal abstraction makes use of artificial neural networks to extract interesting waves and their features from the input signals. A temporal reasoner called a chronicle recogniser processes such series in order to discover temporal patterns called chronicles which can be related to cardiac arrhythmias. Generally, it is difficult to elicit an accurate set of chronicles from a doctor. Thus, we propose to learn automatically from symbolic ECG examples the chronicles discriminating the arrhythmias belonging to some specific subset. Since temporal relationships are of major importance, inductive logic programming (ILP) is the tool of choice as it enables first-order relational learning. The approach has been evaluated on real ECGs taken from the MIT-BIH database. The performance of the different modules as well as the efficiency of the whole system is presented. The results are rather good and demonstrate that integrating numerical techniques for low level perception and symbolic techniques for high level classification is very valuable.

Temporal Frequency Modulates Reaction Time Responses to First-Order and Second-Order Motion

ERIC Educational Resources Information Center

Hutchinson, Claire V.; Ledgeway, Tim

2010-01-01

This study investigated the effect of temporal frequency and modulation depth on reaction times for discriminating the direction of first-order (luminance-defined) and second-order (contrast-defined) motion, equated for visibility using equal multiples of direction-discrimination threshold. Results showed that reaction times were heavily…

Supporting temporal queries on clinical relational databases: the S-WATCH-QL language.

PubMed Central

Combi, C.; Missora, L.; Pinciroli, F.

1996-01-01

Due to the ubiquitous and special nature of time, specially in clinical datábases there's the need of particular temporal data and operators. In this paper we describe S-WATCH-QL (Structured Watch Query Language), a temporal extension of SQL, the widespread query language based on the relational model. S-WATCH-QL extends the well-known SQL by the addition of: a) temporal data types that allow the storage of information with different levels of granularity; b) historical relations that can store together both instantaneous valid times and intervals; c) some temporal clauses, functions and predicates allowing to define complex temporal queries. PMID:8947722

Emergent dynamics of spatio-temporal chaos in a heterogeneous excitable medium.

PubMed

Bittihn, Philip; Berg, Sebastian; Parlitz, Ulrich; Luther, Stefan

2017-09-01

Self-organized activation patterns in excitable media such as spiral waves and spatio-temporal chaos underlie dangerous cardiac arrhythmias. While the interaction of single spiral waves with different types of heterogeneity has been studied extensively, the effect of heterogeneity on fully developed spatio-temporal chaos remains poorly understood. We investigate how the complexity and stability properties of spatio-temporal chaos in the Bär-Eiswirth model of excitable media depend on the heterogeneity of the underlying medium. We employ different measures characterizing the chaoticity of the system and find that the spatial arrangement of multiple discrete lower excitability regions has a strong impact on the complexity of the dynamics. Varying the number, shape, and spatial arrangement of the heterogeneities, we observe strong emergent effects ranging from increases in chaoticity to the complete cessation of chaos, contrasting the expectation from the homogeneous behavior. The implications of our findings for the development and treatment of arrhythmias in the heterogeneous cardiac muscle are discussed.

Learning complex temporal patterns with resource-dependent spike timing-dependent plasticity.

PubMed

Hunzinger, Jason F; Chan, Victor H; Froemke, Robert C

2012-07-01

Studies of spike timing-dependent plasticity (STDP) have revealed that long-term changes in the strength of a synapse may be modulated substantially by temporal relationships between multiple presynaptic and postsynaptic spikes. Whereas long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength have been modeled as distinct or separate functional mechanisms, here, we propose a new shared resource model. A functional consequence of our model is fast, stable, and diverse unsupervised learning of temporal multispike patterns with a biologically consistent spiking neural network. Due to interdependencies between LTP and LTD, dendritic delays, and proactive homeostatic aspects of the model, neurons are equipped to learn to decode temporally coded information within spike bursts. Moreover, neurons learn spike timing with few exposures in substantial noise and jitter. Surprisingly, despite having only one parameter, the model also accurately predicts in vitro observations of STDP in more complex multispike trains, as well as rate-dependent effects. We discuss candidate commonalities in natural long-term plasticity mechanisms.

Emergent dynamics of spatio-temporal chaos in a heterogeneous excitable medium

NASA Astrophysics Data System (ADS)

Bittihn, Philip; Berg, Sebastian; Parlitz, Ulrich; Luther, Stefan

2017-09-01

Self-organized activation patterns in excitable media such as spiral waves and spatio-temporal chaos underlie dangerous cardiac arrhythmias. While the interaction of single spiral waves with different types of heterogeneity has been studied extensively, the effect of heterogeneity on fully developed spatio-temporal chaos remains poorly understood. We investigate how the complexity and stability properties of spatio-temporal chaos in the Bär-Eiswirth model of excitable media depend on the heterogeneity of the underlying medium. We employ different measures characterizing the chaoticity of the system and find that the spatial arrangement of multiple discrete lower excitability regions has a strong impact on the complexity of the dynamics. Varying the number, shape, and spatial arrangement of the heterogeneities, we observe strong emergent effects ranging from increases in chaoticity to the complete cessation of chaos, contrasting the expectation from the homogeneous behavior. The implications of our findings for the development and treatment of arrhythmias in the heterogeneous cardiac muscle are discussed.

Mu-opiate receptors measured by positron emission tomography are increased in temporal lobe epilepsy.

PubMed

Frost, J J; Mayberg, H S; Fisher, R S; Douglass, K H; Dannals, R F; Links, J M; Wilson, A A; Ravert, H T; Rosenbaum, A E; Snyder, S H

1988-03-01

Neurochemical studies in animal models of epilepsy have demonstrated the importance of multiple neurotransmitters and their receptors in mediating seizures. The role of opiate receptors and endogenous opioid peptides in seizure mechanisms is well developed and is the basis for measuring opiate receptors in patients with epilepsy. Patients with complex partial seizures due to unilateral temporal seizure foci were studied by positron emission tomography using 11C-carfentanil to measure mu-opiate receptors and 18F-fluoro-deoxy-D-glucose to measure glucose utilization. Opiate receptor binding is greater in the temporal neocortex on the side of the electrical focus than on the opposite side. Modeling studies indicate that the increase in binding is due to an increase in affinity or the number of unoccupied receptors. No significant asymmetry of 11C-carfentanil binding was detected in the amygdala or hippocampus. Glucose utilization correlated inversely with 11C-carfentanil binding in the temporal neocortex. Increased opiate receptors in the temporal neocortex may represent a tonic anticonvulsant system that limits the spread of electrical activity from other temporal lobe structures.

Models of Temporal Discounting 1937-2000: An Interdisciplinary Exchange between Economics and Psychology.

PubMed

Grüne-Yanoff, Till

2015-12-01

Today's models of temporal discounting are the result of multiple interdisciplinary exchanges between psychology and economics. Although these exchanges did not result in an integrated discipline, they had important effects on all disciplines involved. The paper describes these exchanges from the 1930s onwards, focusing on two episodes in particular: an attempted synthesis by psychiatrist George Ainslie and others in the 1970s; and the attempted application of this new discounting model by a generation of economists and psychologists in the 1980s, which ultimately ended in the diversity of measurements disappointment. I draw four main conclusions. First, multiple notions of temporal discounting must be conceptually distinguished. Second, behavioral economics is not an integration or unification of psychology and economics. Third, the analysis identifies some central disciplinary markers that distinguish modeling strategies in economics and psychology. Finally, it offers a case of interdisciplinary success that does not fit the currently dominant account of interdisciplinarity as integration.

Temporal trends in dancing among adults between 1994 and 2012: The Health Survey for England.

PubMed

Vassallo, Amy Jo; Hiller, Claire E; Pappas, Evangelos; Stamatakis, Emmanuel

2018-01-01

The benefits of physical activity are established, however, increasing population physical activity levels remains a challenge. Participating in activities that are enjoyable and multidimensional, such as dancing, are associated with better adherence. However, the extent to which the general population participates in dancing and its temporal trends has not been well studied. The aim of this study was to investigate temporal trends and patterns and correlates of dance participation in England from 1994 to 2012 using a series of large nationally representative surveys. We used data from the Health Survey for England 1994, 1997, 1998, 1999, 2003, 2004, 2006, 2008 and 2012 to examine dance temporal trends. Temporal trends data were age-standardized and correlates of dance participation were examined for males and females over each study year. Changes in population prevalence of dance participation were determined using multiple logistical regression with 1997 as the reference year. Of all survey participants (n=98,178) 7.8% (95%CI: 7.63-7.96) reported dance participation. There was a marked steady decrease over time, with the steepest decline from 2003 onwards. The multivariable-adjusted odds ratios for dance participation were 0.51 for males (95%CI 0.408-0.630, p<0.001) and 0.69 for females (95%CI: 0.598-0.973, p<0.001) in 2012 compared to 1997. Dance participation in adults in England has decreased markedly over time. This study suggests that dance is not being adequately utilized as a health enhancing physical activity, and therefore further research and resources should be dedicated to supporting dance in the community. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluating the status of individuals and populations: Advantages of multiple approaches and time scales: Chapter 6

USGS Publications Warehouse

Monson, Daniel H.; Bowen, Lizabeth

2015-01-01

Overall, a variety of indices used to measure population status throughout the sea otter’s range have provided insights for understanding the mechanisms driving the trajectory of various sea otter populations, which a single index could not, and we suggest using multiple methods to measure a population’s status at multiple spatial and temporal scales. The work described here also illustrates the usefulness of long-term data sets and/or approaches that can be used to assess population status retrospectively, providing information otherwise not available. While not all systems will be as amenable to using all the approaches presented here, we expect innovative researchers could adapt analogous multi-scale methods to a broad range of habitats and species including apex predators occupying the top trophic levels, which are often of conservation concern.

Flexible retrospective selection of temporal resolution in real-time speech MRI using a golden-ratio spiral view order.

PubMed

Kim, Yoon-Chul; Narayanan, Shrikanth S; Nayak, Krishna S

2011-05-01

In speech production research using real-time magnetic resonance imaging (MRI), the analysis of articulatory dynamics is performed retrospectively. A flexible selection of temporal resolution is highly desirable because of natural variations in speech rate and variations in the speed of different articulators. The purpose of the study is to demonstrate a first application of golden-ratio spiral temporal view order to real-time speech MRI and investigate its performance by comparison with conventional bit-reversed temporal view order. Golden-ratio view order proved to be more effective at capturing the dynamics of rapid tongue tip motion. A method for automated blockwise selection of temporal resolution is presented that enables the synthesis of a single video from multiple temporal resolution videos and potentially facilitates subsequent vocal tract shape analysis. Copyright © 2010 Wiley-Liss, Inc.

Spatial-Temporal Data Collection with Compressive Sensing in Mobile Sensor Networks

PubMed Central

Li, Jiayin; Guo, Wenzhong; Chen, Zhonghui; Xiong, Neal

2017-01-01

Compressive sensing (CS) provides an energy-efficient paradigm for data gathering in wireless sensor networks (WSNs). However, the existing work on spatial-temporal data gathering using compressive sensing only considers either multi-hop relaying based or multiple random walks based approaches. In this paper, we exploit the mobility pattern for spatial-temporal data collection and propose a novel mobile data gathering scheme by employing the Metropolis-Hastings algorithm with delayed acceptance, an improved random walk algorithm for a mobile collector to collect data from a sensing field. The proposed scheme exploits Kronecker compressive sensing (KCS) for spatial-temporal correlation of sensory data by allowing the mobile collector to gather temporal compressive measurements from a small subset of randomly selected nodes along a random routing path. More importantly, from the theoretical perspective we prove that the equivalent sensing matrix constructed from the proposed scheme for spatial-temporal compressible signal can satisfy the property of KCS models. The simulation results demonstrate that the proposed scheme can not only significantly reduce communication cost but also improve recovery accuracy for mobile data gathering compared to the other existing schemes. In particular, we also show that the proposed scheme is robust in unreliable wireless environment under various packet losses. All this indicates that the proposed scheme can be an efficient alternative for data gathering application in WSNs. PMID:29117152

Spatial-Temporal Data Collection with Compressive Sensing in Mobile Sensor Networks.

PubMed

Zheng, Haifeng; Li, Jiayin; Feng, Xinxin; Guo, Wenzhong; Chen, Zhonghui; Xiong, Neal

2017-11-08

Compressive sensing (CS) provides an energy-efficient paradigm for data gathering in wireless sensor networks (WSNs). However, the existing work on spatial-temporal data gathering using compressive sensing only considers either multi-hop relaying based or multiple random walks based approaches. In this paper, we exploit the mobility pattern for spatial-temporal data collection and propose a novel mobile data gathering scheme by employing the Metropolis-Hastings algorithm with delayed acceptance, an improved random walk algorithm for a mobile collector to collect data from a sensing field. The proposed scheme exploits Kronecker compressive sensing (KCS) for spatial-temporal correlation of sensory data by allowing the mobile collector to gather temporal compressive measurements from a small subset of randomly selected nodes along a random routing path. More importantly, from the theoretical perspective we prove that the equivalent sensing matrix constructed from the proposed scheme for spatial-temporal compressible signal can satisfy the property of KCS models. The simulation results demonstrate that the proposed scheme can not only significantly reduce communication cost but also improve recovery accuracy for mobile data gathering compared to the other existing schemes. In particular, we also show that the proposed scheme is robust in unreliable wireless environment under various packet losses. All this indicates that the proposed scheme can be an efficient alternative for data gathering application in WSNs .

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.

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

Multiple fMRI system-level baseline connectivity is disrupted in patients with consciousness alterations.

PubMed

Demertzi, Athena; Gómez, Francisco; Crone, Julia Sophia; Vanhaudenhuyse, Audrey; Tshibanda, Luaba; Noirhomme, Quentin; Thonnard, Marie; Charland-Verville, Vanessa; Kirsch, Murielle; Laureys, Steven; Soddu, Andrea

2014-03-01

In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the ten-network model in severely brain-injured patients suffering from disorders of consciousness and to identify those networks which will be most relevant to discriminate between patients and healthy subjects. 300 fMRI volumes were obtained in 27 healthy controls and 53 patients in minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/UWS) and coma. Independent component analysis (ICA) reduced data dimensionality. The ten networks were identified by means of a multiple template-matching procedure and were tested on neuronality properties (neuronal vs non-neuronal) in a data-driven way. Univariate analyses detected between-group differences in networks' neuronal properties and estimated voxel-wise functional connectivity in the networks, which were significantly less identifiable in patients. A nearest-neighbor "clinical" classifier was used to determine the networks with high between-group discriminative accuracy. Healthy controls were characterized by more neuronal components compared to patients in VS/UWS and in coma. Compared to healthy controls, fewer patients in MCS and VS/UWS showed components of neuronal origin for the left executive control network, default mode network (DMN), auditory, and right executive control network. The "clinical" classifier indicated the DMN and auditory network with the highest accuracy (85.3%) in discriminating patients from healthy subjects. FMRI multiple-network resting state connectivity is disrupted in severely brain-injured patients suffering from disorders of consciousness. When performing ICA, multiple-network testing and control for neuronal properties of the identified RSNs can advance fMRI system-level characterization. Automatic data-driven patient classification is the first step towards future single-subject objective diagnostics

Cerebrospinal fluid dehydroepiandrosterone levels are correlated with brain dehydroepiandrosterone levels, elevated in Alzheimer's disease, and related to neuropathological disease stage.

PubMed

Naylor, Jennifer C; Hulette, Christine M; Steffens, David C; Shampine, Lawrence J; Ervin, John F; Payne, Victoria M; Massing, Mark W; Kilts, Jason D; Strauss, Jennifer L; Calhoun, Patrick S; Calnaido, Rohana P; Blazer, Daniel G; Lieberman, Jeffrey A; Madison, Roger D; Marx, Christine E

2008-08-01

It is currently unknown whether cerebrospinal fluid (CSF) neurosteroid levels are related to brain neurosteroid levels in humans. CSF and brain dehydroepiandrosterone (DHEA) levels are elevated in patients with Alzheimer's disease (AD), but it is unclear whether CSF DHEA levels are correlated with brain DHEA levels within the same subject cohort. We therefore determined DHEA and pregnenolone levels in AD patients (n = 25) and cognitively intact control subjects (n = 16) in both CSF and temporal cortex. DHEA and pregnenolone levels were determined by gas chromatography/mass spectrometry preceded by HPLC. Frozen CSF and temporal cortex specimens were provided by the Alzheimer's Disease Research Center at Duke University Medical Center. Data were analyzed by Mann-Whitney U test statistic and Spearman correlational analyses. CSF DHEA levels are positively correlated with temporal cortex DHEA levels (r = 0.59, P < 0.0001) and neuropathological disease stage (Braak and Braak) (r = 0.42, P = 0.007). CSF pregnenolone levels are also positively correlated with temporal cortex pregnenolone levels (r = 0.57, P < 0.0001) and tend to be correlated with neuropathological disease stage (Braak) (r = 0.30, P = 0.06). CSF DHEA levels are elevated (P = 0.032), and pregnenolone levels tend to be elevated (P = 0.10) in patients with AD, compared with cognitively intact control subjects. These findings indicate that CSF DHEA and pregnenolone levels are correlated with temporal cortex brain levels of these neurosteroids and that CSF DHEA is elevated in AD and related to neuropathological disease stage. Neurosteroids may thus be relevant to the pathophysiology of AD.

Compilation and analysis of multiple groundwater-quality datasets for Idaho

USGS Publications Warehouse

Hundt, Stephen A.; Hopkins, Candice B.

2018-05-09

Groundwater is an important source of drinking and irrigation water throughout Idaho, and groundwater quality is monitored by various Federal, State, and local agencies. The historical, multi-agency records of groundwater quality include a valuable dataset that has yet to be compiled or analyzed on a statewide level. The purpose of this study is to combine groundwater-quality data from multiple sources into a single database, to summarize this dataset, and to perform bulk analyses to reveal spatial and temporal patterns of water quality throughout Idaho. Data were retrieved from the Water Quality Portal (https://www.waterqualitydata.us/), the Idaho Department of Environmental Quality, and the Idaho Department of Water Resources. Analyses included counting the number of times a sample location had concentrations above Maximum Contaminant Levels (MCL), performing trends tests, and calculating correlations between water-quality analytes. The water-quality database and the analysis results are available through USGS ScienceBase (https://doi.org/10.5066/F72V2FBG).

Detection of whole-brain abnormalities in temporal lobe epilepsy using tensor-based morphometry with DARTEL

NASA Astrophysics Data System (ADS)

Li, Wenjing; He, Huiguang; Lu, Jingjing; Lv, Bin; Li, Meng; Jin, Zhengyu

2009-10-01

Tensor-based morphometry (TBM) is an automated technique for detecting the anatomical differences between populations by examining the gradients of the deformation fields used to nonlinearly warp MR images. The purpose of this study was to investigate the whole-brain volume changes between the patients with unilateral temporal lobe epilepsy (TLE) and the controls using TBM with DARTEL, which could achieve more accurate inter-subject registration of brain images. T1-weighted images were acquired from 21 left-TLE patients, 21 right-TLE patients and 21 healthy controls, which were matched in age and gender. The determinants of the gradient of deformation fields at voxel level were obtained to quantify the expansion or contraction for individual images relative to the template, and then logarithmical transformation was applied on it. A whole brain analysis was performed using general lineal model (GLM), and the multiple comparison was corrected by false discovery rate (FDR) with p<0.05. For left-TLE patients, significant volume reductions were found in hippocampus, cingulate gyrus, precentral gyrus, right temporal lobe and cerebellum. These results potentially support the utility of TBM with DARTEL to study the structural changes between groups.

Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

PubMed Central

Vitello, Sylvia; Warren, Jane E.; Devlin, Joseph T.; Rodd, Jennifer M.

2014-01-01

Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., “bark,” “bank”). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretation of an ambiguous word. Here we used fMRI to investigate this hypothesis. 20 native British English monolinguals were scanned whilst listening to sentences that contained an ambiguous word. To induce semantic reinterpretation, the disambiguating information was presented after the ambiguous word and delayed until the end of the sentence (e.g., “the teacher explained that the BARK was going to be very damp”). These sentences were compared to well-matched unambiguous sentences. Supporting the reinterpretation hypothesis, these ambiguous sentences produced more activation in both the LIFG and the left posterior inferior temporal cortex. Importantly, all but one subject showed ambiguity-related peaks within both regions, demonstrating that the group-level results were driven by high inter-subject consistency. Further support came from the finding that activation in both regions was modulated by meaning dominance. Specifically, sentences containing biased ambiguous words, which have one more dominant meaning, produced greater activation than those with balanced ambiguous words, which have two equally frequent meanings. Because the context always supported the less frequent meaning, the biased words require reinterpretation more often than balanced words. This is the first evidence of dominance effects in the spoken modality and provides strong support that frontal and temporal regions support the updating of semantic representations during speech comprehension. PMID

Radiation injury to the temporal bone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guida, R.A.; Finn, D.G.; Buchalter, I.H.

1990-01-01

Osteoradionecrosis of the temporal bone is an unusual sequela of radiation therapy to the head and neck. Symptoms occur many years after the radiation is administered, and progression of the disease is insidious. Hearing loss (sensorineural, conductive, or mixed), otalgia, otorrhea, and even gross tissue extrusion herald this condition. Later, intracranial complications such as meningitis, temporal lobe or cerebellar abscess, and cranial neuropathies may occur. Reported here are five cases of this rare malady representing varying degrees of the disease process. They include a case of radiation-induced necrosis of the tympanic ring with persistent squamous debris in the external auditorymore » canal and middle ear. Another case demonstrates the progression of radiation otitis media to mastoiditis with bony sequestration. Further progression of the disease process is seen in a third case that evolved into multiple cranial neuropathies from skull base destruction. Treatment includes systemic antibiotics, local wound care, and debridement in cases of localized tissue involvement. More extensive debridement with removal of sequestrations, abscess drainage, reconstruction with vascularized tissue from regional flaps, and mastoid obliteration may be warranted for severe cases. Hyperbaric oxygen therapy has provided limited benefit.« less

Scaling in cognitive performance reflects multiplicative multifractal cascade dynamics

PubMed Central

Stephen, Damian G.; Anastas, Jason R.; Dixon, James A.

2012-01-01

Self-organized criticality purports to build multi-scaled structures out of local interactions. Evidence of scaling in various domains of biology may be more generally understood to reflect multiplicative interactions weaving together many disparate scales. The self-similarity of power-law scaling entails homogeneity: fluctuations distribute themselves similarly across many spatial and temporal scales. However, this apparent homogeneity can be misleading, especially as it spans more scales. Reducing biological processes to one power-law relationship neglects rich cascade dynamics. We review recent research into multifractality in executive-function cognitive tasks and propose that scaling reflects not criticality but instead interactions across multiple scales and among fluctuations of multiple sizes. PMID:22529819

Of Time and the Media: Issues of Temporality in Communication Research.

ERIC Educational Resources Information Center

Ritchie, L. David

The role of temporality as a cognitive and cultural factor in communication processes has been largely neglected in communication research. However, it is possible to examine the representation of time on three levels: allocation of events or actions to categories (as in sacred time versus profane time), temporal orientation, and the content of…

Clinical correlation of biopsy results in patients with temporal arteritis.

PubMed

Yuksel, Volkan; Guclu, Orkut; Tastekin, Ebru; Halici, Umit; Huseyin, Serhat; Inal, Volkan; Canbaz, Suat

2017-11-01

Temporal arteritis is systemic vasculitis of medium and large sized vessels. The lowest incidence rates were reported in Turkey, Japan and Israel. We aimed to investigate the results of patients with biopsy-proven temporal arteritis and those classified according to the American College of Rheumatology criteria from a low-incidence region for temporal arteritis. The results of our study are noteworthy, since there is limited data on pathologic diagnosis of temporal arteritis in Turkey. We studied the medical records, laboratory findings such as erythrocyte sedimentation rate and C-reactive protein levels, biopsy results, and postoperative complications of all the patients operated for temporal artery biopsy at our clinic. We used the computerized laboratory registry that keeps all records of 42 consecutive temporal artery biopsy results from January 2011 to December 2016. The mean age was 66±12.5 years. The most common manifestations on admission were temporal headache, optic neuritis and jaw claudication, respectively. Temporal artery biopsy  results confirmed tempoal arteritis in eight out of 42 (19%) patients. There was no statistically significant difference between biopsy-positive and biopsy-negative groups in terms of sex, age, erythrocyte sedimentation rate, C-reactive protein and biopsy length. We were not able to find a correlation between the analysis of biopsy results and clinical evaluation of patients with temporal arteritis. We suggest that diagnosis of temporal arteritis  depends on clinical suspicion. Laboratory examination results may not be helpful in accurate diagnosis of tempoal arteritis.

Automatic temporal segment detection via bilateral long short-term memory recurrent neural networks

NASA Astrophysics Data System (ADS)

Sun, Bo; Cao, Siming; He, Jun; Yu, Lejun; Li, Liandong

2017-03-01

Constrained by the physiology, the temporal factors associated with human behavior, irrespective of facial movement or body gesture, are described by four phases: neutral, onset, apex, and offset. Although they may benefit related recognition tasks, it is not easy to accurately detect such temporal segments. An automatic temporal segment detection framework using bilateral long short-term memory recurrent neural networks (BLSTM-RNN) to learn high-level temporal-spatial features, which synthesizes the local and global temporal-spatial information more efficiently, is presented. The framework is evaluated in detail over the face and body database (FABO). The comparison shows that the proposed framework outperforms state-of-the-art methods for solving the problem of temporal segment detection.

Database of Ground-Water Levels in the Vicinity of Rainier Mesa, Nevada Test Site, Nye County, Nevada, 1957-2005

USGS Publications Warehouse

Fenelon, Joseph M.

2006-01-01

More than 1,200 water-level measurements from 1957 to 2005 in the Rainier Mesa area of the Nevada Test Site were quality assured and analyzed. Water levels were measured from 50 discrete intervals within 18 boreholes and from 4 tunnel sites. An interpretive database was constructed that describes water-level conditions for each water level measured in the Rainier Mesa area. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes hydrograph narratives that describe the water-level history of each well.

TEMPORAL AND SPATIAL PATTERNS OF METHANE EMISSIONS FROM A RESERVOIR DRAINING AN AGRICULTURAL WATERSHED

EPA Science Inventory

We used multiple approaches to characterize temporal and spatial patterns in methane (CH4) emissions from a mid-latitude reservoir (William H. Harsha Lake, Ohio, USA) draining an agricultural watershed. Weekly to monthly monitoring at six sites in the reservoir during a 13 month...

Using Linear and Non-Linear Temporal Adjustments to Align Multiple Phenology Curves, Making Vegetation Status and Health Directly Comparable

NASA Astrophysics Data System (ADS)

Hargrove, W. W.; Norman, S. P.; Kumar, J.; Hoffman, F. M.

2017-12-01

National-scale polar analysis of MODIS NDVI allows quantification of degree of seasonality expressed by local vegetation, and also selects the most optimum start/end of a local "phenological year" that is empirically customized for the vegetation that is growing at each location. Interannual differences in timing of phenology make direct comparisons of vegetation health and performance between years difficult, whether at the same or different locations. By "sliding" the two phenologies in time using a Procrustean linear time shift, any particular phenological event or "completion milestone" can be synchronized, allowing direct comparison of differences in timing of other remaining milestones. Going beyond a simple linear translation, time can be "rubber-sheeted," compressed or dilated. Considering one phenology curve to be a reference, the second phenology can be "rubber-sheeted" to fit that baseline as well as possible by stretching or shrinking time to match multiple control points, which can be any recognizable phenological events. Similar to "rubber sheeting" to georectify a map inside a GIS, rubber sheeting a phenology curve also yields a warping signature that shows at every time and every location how many days the adjusted phenology is ahead or behind the phenological development of the reference vegetation. Using such temporal methods to "adjust" phenologies may help to quantify vegetation impacts from frost, drought, wildfire, insects and diseases by permitting the most commensurate quantitative comparisons with unaffected vegetation.

Reliability of spatial-temporal gait parameters during dual-task interference in people with multiple sclerosis. A cross-sectional study.

PubMed

Monticone, Marco; Ambrosini, Emilia; Fiorentini, Roberta; Rocca, Barbara; Liquori, Valentina; Pedrocchi, Alessandra; Ferrante, Simona

2014-09-01

To evaluate the reliability and minimum detectable change (MDC) of spatial-temporal gait parameters in subjects with multiple sclerosis (MS) during dual tasking. This cross-sectional study involved 25 healthy subjects (mean age 49.9 ± 15.8 years) and 25 people with MS (mean age 49.2 ± 11.5 years). Gait under motor-cognitive and motor-motor dual tasking conditions was evaluated in two sessions separated by a one-day interval using the GAITRite Walkway System. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and coefficients of variation (CV). MDC scores were computed for the velocity, cadence, step and stride length, step and stride time, double support time, the % of gait cycle for single support and stance phase, and base of support. All of the gait parameters reported good to excellent ICCs under both conditions, with healthy subject values of >0.69 and MS subject values of >0.84. SEM values were always below 18% for both groups of subjects. The gait patterns of the people with MS were slightly more variable than those of the normal controls (CVs: 5.88-41.53% vs 2.84-30.48%). The assessment of quantitative gait parameters in healthy subjects and people with MS is highly reliable under both of the investigated dual tasking conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Mapping child maltreatment risk: a 12-year spatio-temporal analysis of neighborhood influences.

PubMed

Gracia, Enrique; López-Quílez, Antonio; Marco, Miriam; Lila, Marisol

2017-10-18

'Place' matters in understanding prevalence variations and inequalities in child maltreatment risk. However, most studies examining ecological variations in child maltreatment risk fail to take into account the implications of the spatial and temporal dimensions of neighborhoods. In this study, we conduct a high-resolution small-area study to analyze the influence of neighborhood characteristics on the spatio-temporal epidemiology of child maltreatment risk. We conducted a 12-year (2004-2015) small-area Bayesian spatio-temporal epidemiological study with all families with child maltreatment protection measures in the city of Valencia, Spain. As neighborhood units, we used 552 census block groups. Cases were geocoded using the family address. Neighborhood-level characteristics analyzed included three indicators of neighborhood disadvantage-neighborhood economic status, neighborhood education level, and levels of policing activity-, immigrant concentration, and residential instability. Bayesian spatio-temporal modelling and disease mapping methods were used to provide area-specific risk estimations. Results from a spatio-temporal autoregressive model showed that neighborhoods with low levels of economic and educational status, with high levels of policing activity, and high immigrant concentration had higher levels of substantiated child maltreatment risk. Disease mapping methods were used to analyze areas of excess risk. Results showed chronic spatial patterns of high child maltreatment risk during the years analyzed, as well as stability over time in areas of low risk. Areas with increased or decreased child maltreatment risk over the years were also observed. A spatio-temporal epidemiological approach to study the geographical patterns, trends over time, and the contextual determinants of child maltreatment risk can provide a useful method to inform policy and action. This method can offer a more accurate description of the problem, and help to inform more

Is This Kid a Likely Experimenter or a Likely Persister? An Analysis of Individual-Level and Family-Level Risk Factors Predicting Multiple Offending Among a Group of Adjudicated Youth.

PubMed

Buker, Hasan; Erbay, Ayhan

2018-02-01

To implement effective diversion programs and determine for a well-suited intervention strategy, ascertaining who, among the adjudicated youth, is more likely to involve in multiple offending, rather than desisting after an initial delinquent behavior, is of great significance. The overall objective of this study, therefore, is to contribute to the existing knowledge on assessing the risks for multiple offending during juvenile adjudication processes. In this regard, this study examined the predicting powers of several individual-level and family-level risk factors on multiple offending during adolescence, based on a data set derived from court-ordered social examination reports (SERs) on 400 adjudicated youth in Turkey. Two binomial regression models were implemented to test the predictor values of various risk factors from these two domains. Results indicated the following as significant predictors of multiple offending among the subjects: younger age of onset in delinquency, dropping out of school, having delinquent/drug abusing (risky) friends, being not able to share problems with the family, increased number of siblings, and having a domestically migrated family. Conclusively, these findings were compared with the existing literature, and the policy implications and recommendations for future research were discussed.

Temporal Coding of Volumetric Imagery

NASA Astrophysics Data System (ADS)

Llull, Patrick Ryan

'Image volumes' refer to realizations of images in other dimensions such as time, spectrum, and focus. Recent advances in scientific, medical, and consumer applications demand improvements in image volume capture. Though image volume acquisition continues to advance, it maintains the same sampling mechanisms that have been used for decades; every voxel must be scanned and is presumed independent of its neighbors. Under these conditions, improving performance comes at the cost of increased system complexity, data rates, and power consumption. This dissertation explores systems and methods capable of efficiently improving sensitivity and performance for image volume cameras, and specifically proposes several sampling strategies that utilize temporal coding to improve imaging system performance and enhance our awareness for a variety of dynamic applications. Video cameras and camcorders sample the video volume (x,y,t) at fixed intervals to gain understanding of the volume's temporal evolution. Conventionally, one must reduce the spatial resolution to increase the framerate of such cameras. Using temporal coding via physical translation of an optical element known as a coded aperture, the compressive temporal imaging (CACTI) camera emonstrates a method which which to embed the temporal dimension of the video volume into spatial (x,y) measurements, thereby greatly improving temporal resolution with minimal loss of spatial resolution. This technique, which is among a family of compressive sampling strategies developed at Duke University, temporally codes the exposure readout functions at the pixel level. Since video cameras nominally integrate the remaining image volume dimensions (e.g. spectrum and focus) at capture time, spectral (x,y,t,lambda) and focal (x,y,t,z) image volumes are traditionally captured via sequential changes to the spectral and focal state of the system, respectively. The CACTI camera's ability to embed video volumes into images leads to exploration