WorldWideScience

Sample records for repeating temporal patterns

  1. Temporal Pattern of the Repeated Bout Effect of Eccentric Exercise on Delayed-Onset Muscle Soreness

    Science.gov (United States)

    Cleary, Michelle A.; Kimura, Iris F.; Sitler, Michael R.; Kendrick, Zebulon V.

    2002-01-01

    Objective: To determine the temporal pattern of the repeated bout effect of eccentric exercise on perceived pain and muscular tenderness associated with delayed-onset muscle soreness (DOMS). Design and Setting: Subjects completed 2 identical eccentric exercise bouts separated by 6, 7, 8, or 9 weeks. The experiment was conducted in a biokinetics research laboratory. Subjects: Sixteen male and 15 female untrained subjects (age = 24.59 ± 4.42 years, height = 171.71 ± 7.81 cm, weight = 73.00 ± 11.20 kg). Measurements: Two physiologic characteristics of DOMS were measured immediately before and 0, 24, 48, and 72 hours after each eccentric exercise bout. Perceived pain was measured using a visual analog scale (VAS), and muscular tenderness was measured using a punctate tenderness gauge (PTG). Results: Two 4 × 2 × 5 (group × bout × time) analyses of variance with repeated measures on the bout and time factors were performed on the VAS and PTG data. Significant (P < .05) main effects were found for group, bout, and time for the VAS and the PTG data. No significant interactions were detected. Post hoc analysis revealed significantly less perceived pain for the 9-week group than the 8-week group. The 7-week group had significantly less and the 8-week group had significantly more muscular tenderness than any other group. Perceived pain and muscular tenderness were significantly less after exercise bout 2 than after exercise bout 1. All subjects had significantly less perceived pain and muscular tenderness pre-exercise than 0 and 24 hours after the eccentric exercise bouts. Conclusions: An effective prophylaxis for perceived pain and muscular tenderness associated with DOMS is the performance of an eccentric exercise bout 6 to 9 weeks before a similar exercise bout. PMID:12937441

  2. Temporal asthma patterns using repeated questionnaires over 13 years in a large French cohort of women.

    Directory of Open Access Journals (Sweden)

    Margaux Sanchez

    Full Text Available Variable expression is one aspect of the heterogeneity of asthma. We aimed to define a variable pattern, which is relevant in general health epidemiological cohorts. Our objectives were to assess whether: 1 asthma patterns defined using simple asthma questions through repeated measurements could reflect disease variability 2 these patterns may further be classified according to asthma severity/control. Among 70,428 French women, we used seven questionnaires (1992-2005 and a comprehensive reimbursement database (2004-2009 to define three reliable asthma patterns based on repeated positive answers to the ever asthma attack question: "never asthma" (n = 64,061; "inconsistent" ("yes" followed by "no", n = 3,514; "consistent" (fully consistent positive answers, n = 2,853. The "Inconsistent" pattern was related to both long-term (childhood-onset asthma with remission in adulthood and short-term (reported asthma attack in the last 12 months, associated with asthma medication asthma variability, showing that repeated questions are relevant markers of the variable expression of asthma. Furthermore, in this pattern, the number of positive responses (1992-2005 predicted asthma drug consumption in subsequent years, a marker of disease severity. The "Inconsistent" pattern is a phenotype that may capture the variable expression of asthma. Repeated answers, even to a simple question, are too often neglected.

  3. Crowding by a repeating pattern.

    Science.gov (United States)

    Rosen, Sarah; Pelli, Denis G

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target-flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker.

  4. A Central Limit Theorem for Repeating Patterns

    CERN Document Server

    Abrams, Aaron; Landau, Henry; Landau, Zeph; Pommersheim, James

    2012-01-01

    This note gives a central limit theorem for the length of the longest subsequence of a random permutation which follows some repeating pattern. This includes the case of any fixed pattern of ups and downs which has at least one of each, such as the alternating case considered by Stanley in [2] and Widom in [3]. In every case considered the convergence in the limit of long permutations is to normal with mean and variance linear in the length of the permutations.

  5. A Repeated Signal Difference for Recognising Patterns

    Directory of Open Access Journals (Sweden)

    Kieran Greer

    2016-08-01

    Full Text Available This paper describes a new mechanism that might help with defining pattern sequences, by the fact that it can produce an upper bound on the ensemble value that can persistently oscillate with the actual values produced from each pattern. With every firing event, a node also receives an on/off feedback switch. If the node fires then it sends a feedback result depending on the input signal strength. If the input signal is positive or larger, it can store an ‘on’ switch feedback for the next iteration. If the signal is negative or smaller it can store an ‘off’ switch feedback for the next iteration. If the node does not fire, then it does not affect the current feedback situation and receives the switch command produced by the last active pattern event for the same neuron. The upper bound therefore also represents the largest or most enclosing pattern set and the lower value is for the actual set of firing patterns. If the pattern sequence repeats, it will oscillate between the two values, allowing them to be recognised and measured more easily, over time. Tests show that changing the sequence ordering produces different value sets, which can also be measured.

  6. Temporal summation and motor function modulation during repeated jaw movements in patients with temporomandibular disorder pain and healthy controls

    DEFF Research Database (Denmark)

    Zhang, Yuanxiu; Shao, Sheng; Zhang, Jinglu

    2017-01-01

    Temporal summation of nociceptive inputs may be an important pathophysiological mechanism in temporomandibular disorders (TMD) pain; however, it remains unknown how natural jaw function relates to underlying pain mechanisms. This study evaluated changes in pain and movement patterns during repeated...... velocity (P = 0.039) increased. The study demonstrates that repeated jaw movements constitute a sufficient and adequate stimulation for triggering temporal summation effects associated with significant inhibition of motor function in painful TMJs. These findings have practical implications for diagnosis...

  7. Optimal temporal patterns for dynamical cellular signaling

    Science.gov (United States)

    Hasegawa, Yoshihiko

    2016-11-01

    Cells use temporal dynamical patterns to transmit information via signaling pathways. As optimality with respect to the environment plays a fundamental role in biological systems, organisms have evolved optimal ways to transmit information. Here, we use optimal control theory to obtain the dynamical signal patterns for the optimal transmission of information, in terms of efficiency (low energy) and reliability (low uncertainty). Adopting an activation-deactivation decoding network, we reproduce several dynamical patterns found in actual signals, such as steep, gradual, and overshooting dynamics. Notably, when minimizing the energy of the input signal, the optimal signals exhibit overshooting, which is a biphasic pattern with transient and steady phases; this pattern is prevalent in actual dynamical patterns. We also identify conditions in which these three patterns (steep, gradual, and overshooting) confer advantages. Our study shows that cellular signal transduction is governed by the principle of minimizing free energy dissipation and uncertainty; these constraints serve as selective pressures when designing dynamical signaling patterns.

  8. Efficient online detection of temporal patterns

    Directory of Open Access Journals (Sweden)

    Shlomi Dolev

    2016-04-01

    Full Text Available Identifying a temporal pattern of events is a fundamental task of online (real-time verification. We present efficient schemes for online monitoring of events for identifying desired/undesired patterns of events. The schemes use preprocessing to ensure that the number of comparisons during run-time is minimized. In particular, the first comparison following the time point when an execution sub-sequence cannot be further extended to satisfy the temporal requirements halts the process that monitors the sub-sequence.

  9. Animating streamlines with repeated asymmetric patterns for steady flow visualization

    Science.gov (United States)

    Yeh, Chih-Kuo; Liu, Zhanping; Lee, Tong-Yee

    2012-01-01

    Animation provides intuitive cueing for revealing essential spatial-temporal features of data in scientific visualization. This paper explores the design of Repeated Asymmetric Patterns (RAPs) in animating evenly-spaced color-mapped streamlines for dense accurate visualization of complex steady flows. We present a smooth cyclic variable-speed RAP animation model that performs velocity (magnitude) integral luminance transition on streamlines. This model is extended with inter-streamline synchronization in luminance varying along the tangential direction to emulate orthogonal advancing waves from a geometry-based flow representation, and then with evenly-spaced hue differing in the orthogonal direction to construct tangential flow streaks. To weave these two mutually dual sets of patterns, we propose an energy-decreasing strategy that adopts an iterative yet efficient procedure for determining the luminance phase and hue of each streamline in HSL color space. We also employ adaptive luminance interleaving in the direction perpendicular to the flow to increase the contrast between streamlines.

  10. Explaining temporal patterns in street robbery

    OpenAIRE

    Tompson, L. A.

    2016-01-01

    This thesis is concerned with explaining spatio-temporal patterns in street robbery through the lens of environmental criminology. The research question ‘what makes a place criminogenic for street robbery at some times and not others?’ is used to frame seven hypotheses. These centre on some of the features of the natural and built environment that can be considered criminogenic (i.e. crime producing). Specifically, the hypotheses test the time-varying influence of darkness, weather conditions...

  11. Temporal sleep patterns in adults using actigraph

    OpenAIRE

    Lia Matuzaki; Rogerio Santos-Silva; Elaine Cristina Marqueze; Claudia Roberta de Castro Moreno; Sergio Tufik; Lia Bittencourt

    2014-01-01

    The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m2, and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by ...

  12. Temporal sleep patterns in adults using actigraph

    Directory of Open Access Journals (Sweden)

    Lia Matuzaki

    2014-09-01

    Full Text Available The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m2, and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences.

  13. Temporal sleep patterns in adults using actigraph

    Science.gov (United States)

    Matuzaki, Lia; Santos-Silva, Rogerio; Marqueze, Elaine Cristina; de Castro Moreno, Claudia Roberta; Tufik, Sergio; Bittencourt, Lia

    2014-01-01

    The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m2, and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences. PMID:26483920

  14. Temporal sleep patterns in adults using actigraph.

    Science.gov (United States)

    Matuzaki, Lia; Santos-Silva, Rogerio; Marqueze, Elaine Cristina; de Castro Moreno, Claudia Roberta; Tufik, Sergio; Bittencourt, Lia

    2014-09-01

    The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m(2), and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences.

  15. Practical use of the repeating patterns in mask writing

    Science.gov (United States)

    Shoji, Masahiro; Inoue, Tadao; Yamabe, Masaki

    2010-03-01

    In May 2006, the Mask Design, Drawing, and Inspection Technology Research Department (Mask D2I) at the Association of Super-Advanced Electronics Technologies (ASET) launched a 4-year program for reducing mask manufacturing cost and TAT by concurrent optimization of MDP, mask writing, and mask inspection. As one of the tasks being pursued at the Mask Design Data Technology Research Laboratory, we have evaluated the effect of reducing the drawing shot counts by utilizing the repeating patterns, and showed positive impact on mask making by using CP drawing. During the past four years, we have developed a software to extract repeating patterns from fractured OPCed mask data which can be used to minimize the shot counts. In this evaluation, we have used an actual device production data obtained from the member companies of MaskD2I. To the extraction software we added new functions for extracting common repeating patterns from a set of multiple masks, and studied how this step can reduce the counts in comparison to the shot counts required during the conventional mask writing techniques. We have also developed software that uses the extraction result of repeating patterns and prepares drawing-data for the MCC/CP drawing system, which has been developed at the Mask Writing Equipment Technology Research Laboratory. With this software, we have simulated EB proximity effect on CP writing and examined how it affect the shot count reduction where CP shots with large CD errors are to be divided into VSB shots. In this paper, we will report the evaluation result of the practical application of repeating patterns in mask writing with this software.

  16. Music snippet extraction via melody-based repeated pattern discovery

    Institute of Scientific and Technical Information of China (English)

    XU JiePing; ZHAO Yang; CHEN Zhe; LIU ZiLi

    2009-01-01

    In this paper, we present a complete set of procedures to automatically extract a music snippet, defined as the most representative or the highlighted excerpt of a music clip. We first generate a modified and compact similarity matrix based on selected features and distance metrics, and then several improved techniques for music repeated pattern discovery are utilized because a music snippet is usually a part of the repeated melody, main theme or chorus. During the process, redundant and wrongly detected patterns are discarded, boundaries are corrected using beat information, and final clusters are also further sorted according to the occurrence frequency and energy information. Subsequently, following our methods, we designed a music snippet extraction system which allows users to detect snippets. Experiments performed on the system show the superiority of our proposed approach.

  17. Coding of multisensory temporal patterns in human superior temporal sulcus

    Directory of Open Access Journals (Sweden)

    Toemme eNoesselt

    2012-08-01

    Full Text Available Philosophers, psychologists, and neuroscientists have long been interested in how the temporal aspects of perception are represented in the brain. In the present study, we investigated the neural basis of the temporal perception of synchrony/asynchrony for audiovisual speech stimuli using functional magnetic imaging (fMRI. Subjects judged the temporal relation of (asynchronous audiovisual speech streams, and indicated any changes in their perception of the stimuli over time. Differential hemodynamic responses for synchronous versus asynchronous stimuli were observed in the multisensory superior temporal sulcus complex (mSTS-c and prefrontal cortex. Within mSTS-c we found adjacent regions expressing an enhanced BOLD-response to the different physical (asynchrony conditions. These regions were further modulated by the subjects’ perceptual state. By calculating the distances between the modulated regions within mSTS-c in single-subjects we demonstrate that the ‘auditory’ and ‘visual leading areas’ lie closer to ‘synchrony areas’ than to each other. Moreover, analysis of interregional connectivity indicates a stronger functional connection between multisensory prefrontal cortex and mSTS-c during the perception of asynchrony. Taken together, these results therefore suggest the presence of distinct sub-regions within the human STS-c for the maintenance of temporal relations for audiovisual speech stimuli plus differential functional connectivity with prefrontal regions. The respective local activity in mSTS-c is dependent both upon the physical properties of the stimuli presented and upon the subjects’ perception of (asynchrony.

  18. Scaling properties in temporal patterns of schizophrenia

    Science.gov (United States)

    Dünki, R. M.; Ambühl, B.

    1996-02-01

    Investigations into the patterns of schizophrenia reveal evidence of scaling properties in temporal behaviour. This is shown in the spectral properties of mid-range and long-range (up to two years) daily recordings from a sample of patients drawn at the therapeutic dwelling SOTERIA (Ambühl et al., in: Springer Series in Synergetics, Vol. 58, eds. Tschacher et al. (Springer, Berlin, 1992) pp. 195-203 and references therein) of the Psychiatric University Hospital in Bern. The therapeutic setting is unique in that it tries to avoid treatment by medication. Power law behaviour has been found within fractal walk analysis and Fourier spectra for the daily fluctuations. A simple dynamic principle, based on a generic intermittency model, is put in relation to these time series thus predicting an additional scaling law for the distribution P( T) of time spans T between successive hospitalizations. Testing this hypothesis with our data shows only insignificant deviations. A possible role of this dynamic principle in the risk assignment of psychotic phases is explored with the help of an example.

  19. Spatio-temporal databases complex motion pattern queries

    CERN Document Server

    Vieira, Marcos R

    2013-01-01

    This brief presents several new query processing techniques, called complex motion pattern queries, specifically designed for very large spatio-temporal databases of moving objects. The brief begins with the definition of flexible pattern queries, which are powerful because of the integration of variables and motion patterns. This is followed by a summary of the expressive power of patterns and flexibility of pattern queries. The brief then present the Spatio-Temporal Pattern System (STPS) and density-based pattern queries. STPS databases contain millions of records with information about mobi

  20. Repeatability of arm pull patterns in front crawl swimming

    Science.gov (United States)

    Su, Lester K.; Kegelman, John C.

    2009-11-01

    The arm pull in human swimming has seen extensive study, particularly involving the front crawl stroke. This work has primarily been aimed either at clarifying the mechanisms of thrust generation by the arm and hand, or at comparing the relative performance of different canonical pulling patterns. In this work we investigate the degree to which swimmers adjust their arm and hand trajectories in response to instantaneous ambient conditions. Video imaging data from competitive swimmers indicates that there may be wide stroke-to-stroke variations in pull trajectories. This suggests that optimal stroking form may be less about a swimmer's ability to repeat idealized pull patterns, than about the swimmer's ability to respond to local flow conditions, or what is referred to in the swimming vernacular as the ``feel'' for the water.

  1. A Comparative Study on Temporal Mobile Access Pattern Mining Methods

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    Hanan Fahmy

    2012-03-01

    Full Text Available Mobile users behavior patterns is one of the most critical issues that need to be explored in mobile agent systems. Recently the algorithms of discovering frequent mobile user’s behavior patterns have been studied extensively. Existing mining methods have proposed frequent mobile user's behavior patterns statistically based on requested services and location information. Therefore, other studies considered that the mobile user's dynamic behavior patterns are usually associated with temporal access patterns. In this paper, temporal mobile access pattern methods are studied and compared in terms of complexity and accuracy. The advantages and disadvantages of these methods will be summarized as well

  2. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  3. Temporal pattern of alcohol consumption in the United States.

    Science.gov (United States)

    Arfken, C L

    1988-02-01

    Alcohol is a major risk factor for many causes of injuries. A preliminary assessment of alcohol's involvement in specific causes of injuries must take into account when people are drinking. This study quantified the weekly and diurnal rhythm of alcohol consumption for the general U.S. population using data collected in a national survey. The data showed a strong temporal pattern consisting of more drinking on weekends with daily peaks in the early evening and troughs in the early morning. The national temporal drinking pattern was positively correlated (0.22 to 0.56) with national temporal patterns of motor vehicle accidents, a cause of injury commonly associated with drinking.

  4. Temporal eating patterns: a latent class analysis approach.

    Science.gov (United States)

    Leech, Rebecca M; Worsley, Anthony; Timperio, Anna; McNaughton, Sarah A

    2017-01-07

    There is some evidence that large energy intakes towards the end of the day are associated with adverse health outcomes, however, studies of temporal eating patterns across the day are rare. This study examines the temporal eating patterns of Australian adults using latent class analysis (LCA), as a novel approach. Dietary data (n = 2402 men and n = 2840 women, ≥19 years) from two 24-h recalls collected during the 2011-12 Australian National Nutrition and Physical Activity Survey were analyzed. LCA was performed to identify distinct temporal eating patterns based on whether or not an eating occasion (EO) occurred within each hour of the day. F and adjusted-chi(2) tests assessed differences in sociodemographic and eating patterns (e.g., meal, snack and EO frequency) between latent classes. Three patterns, labelled "Conventional" (men: 43%, women: 41%), "Later lunch" (men: 34%, women: 34%) and "Grazing" (men: 23%, women: 25%) were identified. Men and women with a "Grazing" pattern were significantly younger (P patterns. The "Grazing" pattern was also characterized by a higher EO frequency (P patterns in adults that varied by age, EO frequency, snack frequency and energy intake pattern. LCA is a useful approach to capture differences in EO timing across the day. Future research should examine associations between temporal eating patterns and health.

  5. Graphic Methods for Interpreting Longitudinal Dyadic Patterns From Repeated-Measures Actor-Partner Interdependence Models

    DEFF Research Database (Denmark)

    Perry, Nicholas; Baucom, Katherine; Bourne, Stacia

    2017-01-01

    Researchers commonly use repeated-measures actor–partner interdependence models (RM-APIM) to understand how romantic partners change in relation to one another over time. However, traditional interpretations of the results of these models do not fully or correctly capture the dyadic temporal...... patterns estimated in RM-APIM. Interpretation of results from these models largely focuses on the meaning of single-parameter estimates in isolation from all the others. However, considering individual coefficients separately impedes the understanding of how these associations combine to produce...... to improve the understanding and presentation of dyadic patterns of association described by standard RM-APIMs. The current article briefly reviews the conceptual foundations of RM-APIMs, demonstrates how change-as-outcome RM-APIMs and VFDs can aid interpretation of standard RM-APIMs, and provides a tutorial...

  6. Temporal properties of pattern adaptation of relay cells in the lateral geniculate nucleus of cats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The temporal properties of pattern adaptation of relay cells induced by repeated sinusoidal drifting grating were investigated in the dorsal lateral geniculate nucleus (dLGN) of cats. The results showed that the response amplitude declined and the response latency prolonged when relay cells were pattern-adapted in dLGN, like the similar fmdings in visual cortex. However, in contrast to the result in cortex,the response phase of relay cells advanced. This implies that an inhibition with relatively long latency may participate in the pattern adaptation of dLGN cells and the adaptation in dLGN may be via a mechanism different from that of visual cortex.``

  7. Analysis of brain patterns using temporal measures

    Energy Technology Data Exchange (ETDEWEB)

    Georgopoulos, Apostolos

    2015-08-11

    A set of brain data representing a time series of neurophysiologic activity acquired by spatially distributed sensors arranged to detect neural signaling of a brain (such as by the use of magnetoencephalography) is obtained. The set of brain data is processed to obtain a dynamic brain model based on a set of statistically-independent temporal measures, such as partial cross correlations, among groupings of different time series within the set of brain data. The dynamic brain model represents interactions between neural populations of the brain occurring close in time, such as with zero lag, for example. The dynamic brain model can be analyzed to obtain the neurophysiologic assessment of the brain. Data processing techniques may be used to assess structural or neurochemical brain pathologies.

  8. Bases of motifs for generating repeated patterns with wild cards.

    Science.gov (United States)

    Pisanti, Nadia; Crochemore, Maxime; Grossi, Roberto; Sagot, Marie-France

    2005-01-01

    Motif inference represents one of the most important areas of research in computational biology, and one of its oldest ones. Despite this, the problem remains very much open in the sense that no existing definition is fully satisfying, either in formal terms, or in relation to the biological questions that involve finding such motifs. Two main types of motifs have been considered in the literature: matrices (of letter frequency per position in the motif) and patterns. There is no conclusive evidence in favor of either, and recent work has attempted to integrate the two types into a single model. In this paper, we address the formal issue in relation to motifs as patterns. This is essential to get at a better understanding of motifs in general. In particular, we consider a promising idea that was recently proposed, which attempted to avoid the combinatorial explosion in the number of motifs by means of a generator set for the motifs. Instead of exhibiting a complete list of motifs satisfying some input constraints, what is produced is a basis of such motifs from which all the other ones can be generated. We study the computational cost of determining such a basis of repeated motifs with wild cards in a sequence. We give new upper and lower bounds on such a cost, introducing a notion of basis that is provably contained in (and, thus, smaller) than previously defined ones. Our basis can be computed in less time and space, and is still able to generate the same set of motifs. We also prove that the number of motifs in all bases defined so far grows exponentially with the quorum, that is, with the minimal number of times a motif must appear in a sequence, something unnoticed in previous work. We show that there is no hope to efficiently compute such bases unless the quorum is fixed.

  9. Spatio-temporal Variations of Characteristic Repeating Earthquake Sequences along the Middle America Trench in Mexico

    Science.gov (United States)

    Dominguez, L. A.; Taira, T.; Hjorleifsdottir, V.; Santoyo, M. A.

    2015-12-01

    Repeating earthquake sequences are sets of events that are thought to rupture the same area on the plate interface and thus provide nearly identical waveforms. We systematically analyzed seismic records from 2001 through 2014 to identify repeating earthquakes with highly correlated waveforms occurring along the subduction zone of the Cocos plate. Using the correlation coefficient (cc) and spectral coherency (coh) of the vertical components as selection criteria, we found a set of 214 sequences whose waveforms exceed cc≥95% and coh≥95%. Spatial clustering along the trench shows large variations in repeating earthquakes activity. Particularly, the rupture zone of the M8.1, 1985 earthquake shows an almost absence of characteristic repeating earthquakes, whereas the Guerrero Gap zone and the segment of the trench close to the Guerrero-Oaxaca border shows a significantly larger number of repeating earthquakes sequences. Furthermore, temporal variations associated to stress changes due to major shows episodes of unlocking and healing of the interface. Understanding the different components that control the location and recurrence time of characteristic repeating sequences is a key factor to pinpoint areas where large megathrust earthquakes may nucleate and consequently to improve the seismic hazard assessment.

  10. Temporal alcohol availability predicts first-time drunk driving, but not repeat offending.

    Science.gov (United States)

    Schofield, Timothy P; Denson, Thomas F

    2013-01-01

    Alcohol availability has been linked to drunk driving, but research has not examined whether this relationship is the same for first-time and repeat offenses. We examined the relationship between the business hours of alcohol outlets licensed to serve alcohol for on-premises consumption and misdemeanor-level (first offense) and felony-level drunk driving (repeat offense) charges in New York State in 2009. Longer outlet business hours were associated with more misdemeanor drunk driving charges, but were not associated with felony drunk driving charges. The per capita density of on-premises alcohol outlets did not affect misdemeanor or felony drunk driving charges. The results suggest that temporal alcohol availability may be an impelling factor for first-time drunk driving, but other factors likely influence repeat drunk driving behaviors.

  11. Temporal alcohol availability predicts first-time drunk driving, but not repeat offending.

    Directory of Open Access Journals (Sweden)

    Timothy P Schofield

    Full Text Available Alcohol availability has been linked to drunk driving, but research has not examined whether this relationship is the same for first-time and repeat offenses. We examined the relationship between the business hours of alcohol outlets licensed to serve alcohol for on-premises consumption and misdemeanor-level (first offense and felony-level drunk driving (repeat offense charges in New York State in 2009. Longer outlet business hours were associated with more misdemeanor drunk driving charges, but were not associated with felony drunk driving charges. The per capita density of on-premises alcohol outlets did not affect misdemeanor or felony drunk driving charges. The results suggest that temporal alcohol availability may be an impelling factor for first-time drunk driving, but other factors likely influence repeat drunk driving behaviors.

  12. Repeating Patterns in Kindergarten: Findings from Children's Enactments of Two Activities

    Science.gov (United States)

    Tsamir, Pessia; Tirosh, Dina; Levenson, Esther S.; Barkai, Ruthi; Tabach, Michal

    2017-01-01

    This paper describes kindergarten children's engagement with two patterning activities. The first activity includes two tasks in which children are asked to choose possible ways for extending two different repeating patterns and the second activity calls for comparing different pairs of repeating patterns. Children's recognition of the unit of…

  13. Pattern formations in chaotic spatio-temporal systems

    Indian Academy of Sciences (India)

    Ying Zhang; Shihong Wang; Jinhua Xiao; Hilda A Cerdeira; S Chen; Gang Hu

    2005-06-01

    Pattern formations in chaotic spatio-temporal systems modelled by coupled chaotic oscillators are investigated. We focus on various symmetry breakings and different kinds of chaos synchronization–desynchronization transitions, which lead to certain types of spontaneous spatial orderings and the emergence of some typical ordered patterns, such as rotating wave patterns with splay phase ordering (orientational symmetry breaking) and partially synchronous standing wave patterns with in-phase ordering (translational symmetry breaking). General pictures of the global behaviors of pattern formations and transitions in coupled chaotic oscillators are provided.

  14. Temporal summation and motor function modulation during repeated jaw movements in patients with temporomandibular disorder pain and healthy controls.

    Science.gov (United States)

    Zhang, Yuanxiu; Shao, Sheng; Zhang, Jinglu; Wang, Lin; Wang, Kelun; Svensson, Peter

    2017-07-01

    Temporal summation of nociceptive inputs may be an important pathophysiological mechanism in temporomandibular disorders (TMD) pain; however, it remains unknown how natural jaw function relates to underlying pain mechanisms. This study evaluated changes in pain and movement patterns during repeated jaw movements in patients with painful temporomandibular joints (TMJ) compared with healthy controls. Twenty patients with TMD with TMJ pain, and an anterior disk displacement without reduction and 20 age- and gender-matched healthy volunteers were included. Participants performed 20 trials (4 × 5 sessions) of standardized and repeated mandibular movements, and scored the movement-associated pain intensity on 0 to 10 numeric rating scale in addition to measurements of jaw movements. Patients with TMJ pain reported higher baseline pain compared to the control group for all types of jaw movements (P = 0.001) and significant increases in numeric rating scale pain scores by repetition of jaw movements (P 0.05). Jaw total opening distance (P = 0.030), maximum opening velocity (P = 0.043) and average closing velocity (P = 0.044) in the TMJ pain group were significantly reduced during the repeated movements. In the control group, however, total opening distance (P = 0.499), maximum opening velocity (P = 0.064), and average closing velocity (P = 0.261) remained unchanged, whereas average opening velocity (P = 0.040) and maximum closing velocity (P = 0.039) increased. The study demonstrates that repeated jaw movements constitute a sufficient and adequate stimulation for triggering temporal summation effects associated with significant inhibition of motor function in painful TMJs. These findings have practical implications for diagnosis of TMD pain and for more mechanism-driven management protocols in the future.

  15. TPR repeats and ELTR pattern: length variation as a function evolution mechanism.

    Science.gov (United States)

    Yang, Ke-Qian

    2007-12-01

    TPR repeat was originally defined as a 34 amino acid structural repeat (TPR-34). Equal length tandem repeats (ELTR) was proposed to represent the ancestral repeat pattern. Length polymorphism of TPR repeats was analyzed using PATTINPROT, two new versions of TPR repeat of 40 and 42 amino acids were identified. These 'long' TPRs endow new functional capacities to the resulting proteins. A strong correlation between varied lengths and new functions supports the hypothesis that length variation is an underlying mechanism for the function evolution of repeat containing proteins.

  16. Spike timing dependent plasticity finds the start of repeating patterns in continuous spike trains.

    Directory of Open Access Journals (Sweden)

    Timothée Masquelier

    Full Text Available Experimental studies have observed Long Term synaptic Potentiation (LTP when a presynaptic neuron fires shortly before a postsynaptic neuron, and Long Term Depression (LTD when the presynaptic neuron fires shortly after, a phenomenon known as Spike Timing Dependent Plasticity (STDP. When a neuron is presented successively with discrete volleys of input spikes STDP has been shown to learn 'early spike patterns', that is to concentrate synaptic weights on afferents that consistently fire early, with the result that the postsynaptic spike latency decreases, until it reaches a minimal and stable value. Here, we show that these results still stand in a continuous regime where afferents fire continuously with a constant population rate. As such, STDP is able to solve a very difficult computational problem: to localize a repeating spatio-temporal spike pattern embedded in equally dense 'distractor' spike trains. STDP thus enables some form of temporal coding, even in the absence of an explicit time reference. Given that the mechanism exposed here is simple and cheap it is hard to believe that the brain did not evolve to use it.

  17. Exploring Spatial-Temporal Patterns of Urban Human Mobility Hotspots

    Directory of Open Access Journals (Sweden)

    Xiping Yang

    2016-07-01

    Full Text Available Understanding human mobility patterns provides us with knowledge about human mobility in an urban context, which plays a critical role in urban planning, traffic management and the spread of disease. Recently, the availability of large-scale human-sensing datasets enables us to analyze human mobility patterns and the relationships between humans and their living environments on an unprecedented spatial and temporal scale to improve decision-making regarding the quality of life of citizens. This study aims to characterize the urban spatial-temporal dynamic from the perspective of human mobility hotspots by using mobile phone location data. We propose a workflow to identify human convergent and dispersive hotspots that represent the status of human mobility in local areas and group these hotspots into different classes according to clustering their temporal signatures. To illustrate our proposed approach, a case study of Shenzhen, China, has been conducted. Six typical spatial-temporal patterns in the city are identified and discussed by combining the spatial distribution of these identified patterns with urban functional areas. The findings enable us to understand the human dynamics in a different area of the city, which can serve as a reference for urban planning and traffic management.

  18. The Influence of Relational Knowledge and Executive Function on Preschoolers' Repeating Pattern Knowledge

    Science.gov (United States)

    Miller, Michael R.; Rittle-Johnson, Bethany; Loehr, Abbey M.; Fyfe, Emily R.

    2016-01-01

    Children's knowledge of repeating patterns (e.g., ABBABB) is a central component of early mathematics, but the developmental mechanisms underlying this knowledge are currently unknown. We sought clarity on the importance of relational knowledge and executive function (EF) to preschoolers' understanding of repeating patterns. One hundred…

  19. Quantifying positional and temporal movement patterns in professional rugby union using global positioning system.

    Science.gov (United States)

    Jones, Marc R; West, Daniel J; Crewther, Blair T; Cook, Christian J; Kilduff, Liam P

    2015-01-01

    This study assessed the positional and temporal movement patterns of professional rugby union players during competition using global positioning system (GPS) units. GPS data were collected from 33 professional rugby players from 13 matches throughout the 2012-2013 season sampling at 10 Hz. Players wore GPS units from which information on distances, velocities, accelerations, exertion index, player load, contacts, sprinting and repeated high-intensity efforts (RHIE) were derived. Data files from players who played over 60 min (n = 112) were separated into five positional groups (tight and loose forwards; half, inside and outside backs) for match analysis. A further comparison of temporal changes in movement patterns was also performed using data files from those who played full games (n = 71). Significant positional differences were found for movement characteristics during performance (P drills that elicit specific adaptations and provide objective measures of preparedness. Knowledge of performance changes may be used when developing drills and should be considered when monitoring and evaluating performance.

  20. Spatio-temporal Patterns in Inclined Layer Convection

    CERN Document Server

    Subramanian, Priya; Brausch, Oliver; Daniels, Karen E; Bodenschatz, Eberhard; Schneider, Tobias M

    2015-01-01

    This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle {\\gamma} and the Rayleigh number R. The patterns are shown to originate from a complicated competition of buoyancy-driven and shear-flow driven pattern forming mechanisms. The former is expressed as longitudinal convection rolls with their axes oriented parallel to the incline, the latter as perpendicular transverse rolls. Our investigation is based on the standard Oberbeck-Boussinesq equations. Besides conventional methods to study roll patterns and their stability, we employ in particular, direct numerical simulations in large spatial domains comparable with experimental ones. As a result we arrive at a phase diagram of the characteristic complex 3D convection patterns in the {\\gamma}-R- plane, which compares very well to the experiments. In particular it is demonstrated that interactions of specific Fourier mo...

  1. Rotating waves during human sleep spindles organize global patterns of activity that repeat precisely through the night

    Science.gov (United States)

    Muller, Lyle; Piantoni, Giovanni; Koller, Dominik; Cash, Sydney S; Halgren, Eric; Sejnowski, Terrence J

    2016-01-01

    During sleep, the thalamus generates a characteristic pattern of transient, 11-15 Hz sleep spindle oscillations, which synchronize the cortex through large-scale thalamocortical loops. Spindles have been increasingly demonstrated to be critical for sleep-dependent consolidation of memory, but the specific neural mechanism for this process remains unclear. We show here that cortical spindles are spatiotemporally organized into circular wave-like patterns, organizing neuronal activity over tens of milliseconds, within the timescale for storing memories in large-scale networks across the cortex via spike-time dependent plasticity. These circular patterns repeat over hours of sleep with millisecond temporal precision, allowing reinforcement of the activity patterns through hundreds of reverberations. These results provide a novel mechanistic account for how global sleep oscillations and synaptic plasticity could strengthen networks distributed across the cortex to store coherent and integrated memories. DOI: http://dx.doi.org/10.7554/eLife.17267.001 PMID:27855061

  2. Temporal and spatial patterns of micropollutants in urban receiving waters

    Energy Technology Data Exchange (ETDEWEB)

    Musolff, Andreas, E-mail: andreas.musolff@ufz.d [UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany); Leschik, Sebastian, E-mail: sebastian.leschik@ufz.d [UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany); Moeder, Monika, E-mail: monika.moeder@ufz.d [UFZ - Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, 04318 Leipzig (Germany); Strauch, Gerhard, E-mail: gerhard.strauch@ufz.d [UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany); Reinstorf, Frido, E-mail: frido.reinstorf@hs-magdeburg.d [University of Applied Sciences Magdeburg-Stendal, Department of Water and Waste Management, Breitscheidstr. 2, 39114 Magdeburg (Germany); Schirmer, Mario, E-mail: mario.schirmer@eawag.c [Eawag, The Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Ueberlandstr. 133, 8600 Duebendorf (Switzerland)

    2009-11-15

    Based on a monitoring program over the course of a year, we characterize the temporal and spatial distribution of selected micropollutants in an urban watershed within the city of Leipzig, Germany. Micropollutants revealed a ubiquitous presence in untreated and treated wastewater, surface water and groundwater. The loads of 4-nonylphenol in the effluents of the municipal wastewater treatment plant followed a seasonal trend, whereas the loads of all other micropollutants were highly variable and not correlated to seasons. In the surface water, load seasonality of caffeine, galaxolide and tonalide resulted from a rapid removal with increased water temperature. The loads of 4-nonylphenol and of caffeine in the colder months increased when rainfall occurred. In the groundwater, complex spatial and temporal patterns were apparent and were related to varying input, retardation and removal processes. As a consequence, an assessment of micropollutants in urban waters should consider different micropollutants' temporal and spatial variability. - Micropollutants in urban receiving waters are characterized by variable temporal and spatial concentration and load patterns that have to be considered in risk assessments.

  3. 1987 wet deposition temporal and spatial patterns in North America

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.C.; Olsen, A.R.

    1990-03-01

    The focus of this report is on North American wet deposition temporal patterns from 1979 to 1987 and spatial patterns for 1987. The report investigates the patterns of annual precipitation-weighted average concentration and annual deposition for nine ion species: hydrogen, sulfate, nitrate, ammonium, calcium, chloride, sodium, potassium, and magnesium. Data are from the Acid Deposition System (ADS) for the statistical reporting of North American deposition data which includes the National Atmospheric Deposition Program/National Trends Network (NADP/NTN), the MAP3S precipitation chemistry network, the Utility Acid Precipitation Study Program (UAPSP), the Canadian Precipitation Monitoring Network (CAPMoN), and the daily and 4-weekly Acidic Precipitation in Ontario Study (APIOS-D and APIOS-C). Mosaic maps, based on surface estimation using kriging, display concentration and deposition spatial patterns of pH, hydrogen, sulfate, nitrate, ammonium, and calcium ion species for 1987 annual, winter, and summer periods. The temporal pattern analyses use a subset of 39 sites over a 9-year (1979--1987) period and an expanded subset of 140 sites with greater spatial coverage over a 6-year (1982--1987) period. 68 refs., 15 figs., 15 tabs.

  4. The Repeat Pattern Toolkit (RPT): Analyzing the structure and evolution of the C. elegans genome

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, P.; States, D.J. [Washington Univ., St. Louis, MO (United States)

    1994-12-31

    Over 3.6 million bases of DNA sequence from chromosome III of the C. elegans have been determined. The availability of this extended region of contiguous sequence has allowed us to analyze the nature and prevalence of repetitive sequences in the genome of a eukaryotic organism with a high gene density. We have assembled a Repeat Pattern Toolkit (RPT) to analyze the patterns of repeats occurring in DNA. The tools include identifying significant local alignments (utilizing both two-way and three-way alignments), dividing the set of alignments into connected components (signifying repeat families), computing evolutionary distance between repeat family members, constructing minimum spanning trees from the connected components, and visualizing the evolution of the repeat families. Over 7000 families of repetitive sequences were identified. The size of the families ranged from isolated pairs to over 1600 segments of similar sequence. Approximately 12.3% of the analyzed sequence participates in a repeat element.

  5. Odor identity influences tracking of temporally patterned plumes in Drosophila

    Directory of Open Access Journals (Sweden)

    Frye Mark A

    2011-06-01

    Full Text Available Abstract Background Turbulent fluid landscapes impose temporal patterning upon chemical signals, and the dynamical neuronal responses to patterned input vary across the olfactory receptor repertoire in flies, moths, and locusts. Sensory transformations exhibit low pass filtering that ultimately results in perceptual fusion of temporally transient sensory signals. For example, humans perceive a sufficiently fast flickering light as continuous, but the frequency threshold at which this fusion occurs varies with wavelength. Although the summed frequency sensitivity of the fly antenna has been examined to a considerable extent, it is unknown how intermittent odor signals are integrated to influence plume tracking behavior independent of wind cues, and whether temporal fusion for behavioral tracking might vary according to the odor encountered. Results Here we have adopted a virtual reality flight simulator to study the dynamics of plume tracking under different experimental conditions. Flies tethered in a magnetic field actively track continuous (non-intermittent plumes of vinegar, banana, or ethyl butyrate with equal precision. However, pulsing these plumes at varying frequency reveals that the threshold rate, above which flies track the plume as if it were continuous, is unique for each odorant tested. Thus, the capability of a fly to navigate an intermittent plume depends on the particular odorant being tracked during flight. Finally, we measured antennal field potential responses to an intermittent plume, found that receptor dynamics track the temporal pattern of the odor stimulus and therefore do not limit the observed behavioral temporal fusion limits. Conclusions This study explores the flies' ability to track odor plumes that are temporally intermittent. We were surprised to find that the perceptual critical fusion limit, determined behaviorally, is strongly dependent on odor identity. Antennal field potential recordings indicate that

  6. Nearly a decade-long repeatable seasonal diversity patterns of bacterioplankton communities in the eutrophic Lake Donghu (Wuhan, China)

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Qingyun [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Stegen, James C. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA USA; Yu, Yuhe [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Deng, Ye [CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing China; Li, Xinghao [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Wu, Shu [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Dai, Lili [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Zhang, Xiang [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Li, Jinjin [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Wang, Chun [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Ni, Jiajia [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Li, Xuemei [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Hu, Hongjuan [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Xiao, Fanshu [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Feng, Weisong [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Ning, Daliang [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; He, Zhili [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Van Nostrand, Joy D. [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Wu, Liyou [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Zhou, Jizhong [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing China; Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley CA USA

    2017-05-21

    Uncovering which environmental factors have the greatest influence on community diversity patterns and how ecological processes govern community turnover are key questions related to understanding community assembly mechanisms. Although we have good understanding of plant and animal community assembly, the mechanisms regulating diversity patterns of aquatic bacterial communities in lake ecosystems remains poorly understood. Here we present nearly a decade-long time-series study of bacterioplankton communities from the eutrophic Lake Donghu (Wuhan, China) using 16S rRNA gene amplicon sequencing. We found strong repeatable seasonal patterns for the overall community, common (detected in more than 50% samples) and dominant bacterial taxa (relative abundance > 1%). Moreover, community composition tracked the seasonal temperature gradient, indicating that temperature is an important environmental factor controlling observed diversity patterns. Total phosphorus also contributed significantly to the seasonal shifts in bacterioplankton composition. However, any spatial pattern across the main lake areas was overwhelmed by temporal variability in this eutrophic lake system. Phylogenetic analysis further indicated that 75%-82% of community turnover was governed by homogeneous selection, suggesting that the bacterioplankton communities are mainly controlled by niche-based processes. However, dominant niches available within seasons might be occupied by similar combinations of bacterial taxa with modest dispersal rates throughout this lake system. This study gives us important insights into community assembly and seasonal turnover of lake bacterioplankton, it may be also useful to predict temporal patterns of other planktonic communities.

  7. Bases of motifs for generating repeated patterns with wild cards

    OpenAIRE

    Pisanti, Nadia; Crochemore, Maxime; Grossi, Roberto; Sagot, Marie-France

    2005-01-01

    Motif inference represents one of the most important areas of research in computational biology, and one of its oldest ones. Despite this, the problem remains very much open in the sense that no existing definition is fully satisfying, either in formal terms, or in relation to the biological questions that involve finding such motifs. Two main types of motifs have been considered in the literature: matrices (of letter frequency per position in the motif) and patterns. There is no conclusive e...

  8. Graphic Methods for Interpreting Longitudinal Dyadic Patterns From Repeated-Measures Actor-Partner Interdependence Models

    DEFF Research Database (Denmark)

    Perry, Nicholas; Baucom, Katherine; Bourne, Stacia

    2017-01-01

    Researchers commonly use repeated-measures actor–partner interdependence models (RM-APIM) to understand how romantic partners change in relation to one another over time. However, traditional interpretations of the results of these models do not fully or correctly capture the dyadic temporal...

  9. FIXED TEMPORAL PATTERNS IN CHILDREN'S SPEECH DESPITE VARIABLE VOWEL DURATIONS.

    Science.gov (United States)

    Redford, Melissa A; Oh, Grace E

    2015-08-01

    The current study compared children's and adults' ability to produce inherent and context-specific vowel duration differences with their ability to repeatedly produce the same vowel in the same context. Children (5- and 8-year-olds) and adults produced real English words in a frame sentence multiple times. Mean vowel duration and variability in vowel duration were analysed as a function of the manipulated factors. Results were that children produced exactly the same contrasts as adults despite also exhibiting more variability in their production of individual vowels. The results are consistent with a model where the 'plan' is remembered relative timing information and execution is the achievement of motor goals at specified temporal intervals.

  10. Exploring Temporal Patterns of Stress in Adolescent Girls with Headache.

    Science.gov (United States)

    Björling, Elin A; Singh, Narayan

    2017-02-01

    As part of a larger study on perceived stress and headaches in 2009, momentary perceived stress, head pain levels and stress-related symptom data were collected. This paper explores a temporal analysis of the patterns of stress, as well as an analysis of momentary and retrospective stress-related symptoms compared by level of headache activity. Adolescent girls (N = 31) ages 14-18 were randomly cued by electronic diaries 7 times per day over a 21-day period responding to momentary questions about level of head pain, perceived stress and stress-related symptoms. Multivariate general linear modelling was used to determine significant differences among headache groups in relation to temporal patterns of stress. Significant headache group differences were found on retrospective and momentary stress-related symptom measures. A total of 2841 diary responses captured stress levels, head pain and related symptoms. The chronic headache (CH) group reported the highest levels of hourly and daily stress, followed by the moderate headache (MH) and low headache (LH) groups. Patterns of stress for the three headache groups were statistically distinct, illustrating increased stress in girls with more frequent head pain. This evidence suggests that because of increased stress, girls with recurrent head pain are likely a vulnerable population who may benefit from stress-reducing interventions. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Recurrent coupling improves discrimination of temporal spike patterns

    Directory of Open Access Journals (Sweden)

    Chun-Wei eYuan

    2012-05-01

    Full Text Available Despite the ubiquitous presence of recurrent synaptic connections insensory neuronal systems, their general functional purpose is not wellunderstood. A recent conceptual advance has been achieved by theoriesof reservoir computing in which recurrent networks have been proposedto generate short-term memory as well as to improve neuronalrepresentation of the sensory input for subsequent computations.Here, we present a numerical study on the distinct effects ofinhibitory and excitatory recurrence in a canonical linearclassification task. It is found that both types of coupling improvethe ability to discriminate temporal spike patterns as compared to apurely feed-forward system, although in different ways. For a largeclass of inhibitory networks, the network's performance is optimal aslong as a fraction of roughly 50% of neurons per stimulus is activein the resulting population code. Thereby the contribution of inactiveneurons to the neural code is found to be even more informative thanthat of the active neurons, generating an inherent robustness ofclassification performance against temporal jitter of the inputspikes. Excitatory couplings are found to not only produce ashort-term memory buffer but also to improve linear separability ofthe population patterns by evoking more irregular firing as comparedto the purely inhibitory case. As the excitatory connectivity becomesmore sparse, firing becomes more variable and pattern separabilityimproves. We argue that the proposed paradigm is particularlywell-suited as a conceptual framework for processing of sensoryinformation in the auditory pathway.

  12. Inverse hydrological modelling of spatio-temporal rainfall patterns

    Science.gov (United States)

    Grundmann, Jens; Hörning, Sebastian; Bárdossy, András

    2016-04-01

    Distributed hydrological models are commonly used for simulating the non-linear response of a watershed to rainfall events for addressing different hydrological properties of the landscape. Such models are driven by spatial rainfall patterns for consecutive time steps, which are normally generated from point measurements using spatial interpolation methods. However, such methods fail in reproducing the true spatio-temporal rainfall patterns especially in data scarce regions with poorly gauged catchments or for highly dynamic, small scaled rainstorms which are not well recorded by existing monitoring networks. Consequently, uncertainties are associated with poorly identified spatio-temporal rainfall distribution in distributed rainfall-runoff-modelling since the amount of rainfall received by a catchment as well as the dynamics of the runoff generation of flood waves are underestimated. For addressing these challenges a novel methodology for inverse hydrological modelling is proposed using a Markov-Chain-Monte-Carlo framework. Thereby, potential candidates of spatio-temporal rainfall patterns are generated and selected according their ability to reproduce the observed surface runoff at the catchment outlet for a given transfer function in a best way. The Methodology combines the concept of random mixing of random spatial fields with a grid-based spatial distributed rainfall runoff model. The conditional target rainfall field is obtained as a linear combination of unconditional spatial random fields. The corresponding weights of the linear combination are selected such that the spatial variability of the rainfall amounts as well as the actual observed rainfall values are reproduced. The functionality of the methodology is demonstrated on a synthetic example. Thereby, the known spatio-temporal distribution of rainfall is reproduced for a given number of point observations of rainfall and the integral catchment response at the catchment outlet for a synthetic catchment

  13. TEMPORAL PATTERN OF KINESIOLOGY TAPE EFFICACY ON HAMSTRING EXTENSIBILITY.

    Science.gov (United States)

    Farquharson, Claire; Greig, Matt

    2015-12-01

    Kinesiology tape has been advocated as a means of improving muscle flexibility, a potential modifiable risk factor for injury, over time. The epidemiology and etiology of hamstring injuries in sport have been well documented. To compare the temporal pattern of efficacy of kinesiology tape and traditional stretching techniques on hamstring extensibility over a five day period. Controlled laboratory study. Thirty recreationally active male participants (Mean ± SD: age 20.0 ± 1.55 years; height 179.3 ± 4.94 cm; mass 76.9 ± 7.57 kg) completed an active knee extension assessment (of the dominant leg) as a measure of hamstring extensibility. Three experimental interventions were applied in randomized order: Kinesiology tape (KT), static stretch (SS), proprioceptive neuromuscular facilitation (PNF). Measures were taken at baseline, +1min, + 30mins, + 3days and +5days days after each intervention. The temporal pattern of change in active knee extension was modelled as a range of regression polynomials for each intervention, quantified as the regression coefficient. Hamstring ROM with KT application at +3days was significantly greater than baseline (129.18 ± 15.46%, p = 0.01), SS (106.99 ± 9.84%, p = 0.03) and PNF (107.42 ± 136.13%, p = 0.03) interventions. The temporal pattern of changes in ROM for SS and PNF were best modelled by a negative linear function, although the strength of the correlation was weak in each case. In contrast, the KT data was optimised using a quadratic polynomial function (r(2) = 0.60), which yielded an optimum time of 2.76 days, eliciting a predicted ROM of 129.6% relative to baseline. Each intervention displayed a unique temporal pattern of changes in active knee extension. SS was best suited to immediate improvements, and PNF to +30 minutes in hamstring extensibility, whereas kinesiology tape offered advantages over a longer duration, peaking at 2.76 days. These findings have implications for the

  14. Repeating Patterns: Strategies to Assist Young Students to Generalise the Mathematical Structure

    Science.gov (United States)

    Warren, Elizabeth; Miller, Jodie; Cooper, Thomas

    2012-01-01

    This paper focuses on very young students' ability to engage in repeating pattern tasks and identifying strategies that assist them to ascertain the structure of the pattern. It describes results of a study which is part of the Early Years Generalising Project (EYGP) and involves Australian students in Years 1 to 4 (ages 5-10). This paper reports…

  15. Developing Pre-Algebraic Thinking in Generalizing Repeating Pattern Using SOLO Model

    Science.gov (United States)

    Lian, Lim Hooi; Yew, Wun Thiam

    2011-01-01

    In this paper, researchers discussed the application of the generalization perspective in helping the primary school pupils to develop their pre-algebraic thinking in generalizing repeating pattern. There are two main stages of the generalization perspective had been adapted, namely investigating and generalizing the pattern. Since the Biggs and…

  16. Inferring Synaptic Connectivity from Spatio-Temporal Spike Patterns

    Directory of Open Access Journals (Sweden)

    Frank eVan Bussel

    2011-02-01

    Full Text Available Networks of well-known dynamical units but unknown interaction topology arise across various fields of biology, including genetics, ecology and neuroscience. The collective dynamics of such networks is often sensitive to the presence (or absence of individual interactions, but there is usually no direct way to probe for their existence. Here we present an explicit method for reconstructing interaction networks of leaky integrate-and-fire neurons from the spike patterns they exhibit in response to external driving. Given the dynamical parameters are known, the approach works well for networks in simple collective states but is also applicable to networks exhibiting complex spatio-temporal spike patterns. In particular, stationarity of spiking time series is not required.

  17. An intelligent temporal pattern classification system using fuzzy temporal rules and particle swarm optimization

    Indian Academy of Sciences (India)

    S Ganapathy; R Sethukkarasi; P Yogesh; P Vijayakumar; A Kannan

    2014-04-01

    In this paper, we propose a new pattern classification system by combining Temporal features with Fuzzy Min–Max (TFMM) neural network based classifier for effective decision support in medical diagnosis. Moreover, a Particle Swarm Optimization (PSO) algorithm based rule extractor is also proposed in this work for improving the detection accuracy. Intelligent fuzzy rules are extracted from the temporal features with Fuzzy Min–Max neural network based classifier, and then PSO rule extractor is used to minimize the number of features in the extracted rules. We empirically evaluated the effectiveness of the proposed TFMM-PSO system using the UCI Machine Learning Repository Data Set. The results are analysed and compared with other published results. In addition, the detection accuracy is validated by using the ten-fold cross validation.

  18. Reconstructing spatial and temporal patterns of paleoglaciation across Central Asia

    Science.gov (United States)

    Stroeven, Arjen P.

    2014-05-01

    Understanding the behaviour of mountain glaciers and ice caps, the evolution of mountain landscapes, and testing global climate models all require well-constrained information on past spatial and temporal patterns of glacier change. Particularly important are transitional regions that have high spatial and temporal variation in glacier activity and that can provide a sensitive record of past climate change. Central Asia is an extreme continental location with glaciers that have responded sensitively to variations in major regional climate systems. As an international team, we are reconstructing glacial histories of several areas of the Tibetan Plateau as well as along the Tian Shan, Altai and Kunlun Mountains. Building on previous work, we are using remote sensing-based geomorphological mapping augmented with field observations to map out glacial landforms and the maximum distributions of erratics. We then use cosmogenic nuclide Be-10 and Al-26, optically stimulated luminescence, and electron spin resonance dating of moraines and other landforms to compare dating techniques and to constrain the ages of defined extents of paleo-glaciers and ice caps. Comparing consistently dated glacial histories across central Asia provides an opportunity to examine shifts in the dominance patterns of climate systems over time in the region. Results to date show significant variations in the timing and extent of glaciation, including areas in the southeast Tibetan Plateau and Tian Shan with extensive valley and small polythermal ice cap glaciation during the global last glacial maximum in contrast to areas in central and northeast Tibetan Plateau that had very limited valley glacier expansion then. Initial numerical modelling attempting to simulate mapped and dated paleoglacial extents indicates that relatively limited cooling is sufficient to produce observed past expansions of glaciers across the Tibetan Plateau, and predicts complex basal thermal regimes in some locations that

  19. A Novel Signal Processing Measure to Identify Exact and Inexact Tandem Repeat Patterns in DNA Sequences

    Directory of Open Access Journals (Sweden)

    Ravi Gupta

    2007-03-01

    Full Text Available The identification and analysis of repetitive patterns are active areas of biological and computational research. Tandem repeats in telomeres play a role in cancer and hypervariable trinucleotide tandem repeats are linked to over a dozen major neurodegenerative genetic disorders. In this paper, we present an algorithm to identify the exact and inexact repeat patterns in DNA sequences based on orthogonal exactly periodic subspace decomposition technique. Using the new measure our algorithm resolves the problems like whether the repeat pattern is of period P or its multiple (i.e., 2P, 3P, etc., and several other problems that were present in previous signal-processing-based algorithms. We present an efficient algorithm of O(NLw logLw, where N is the length of DNA sequence and Lw is the window length, for identifying repeats. The algorithm operates in two stages. In the first stage, each nucleotide is analyzed separately for periodicity, and in the second stage, the periodic information of each nucleotide is combined together to identify the tandem repeats. Datasets having exact and inexact repeats were taken up for the experimental purpose. The experimental result shows the effectiveness of the approach.

  20. Enhanced methane production via repeated batch bioaugmentation pattern of enriched microbial consortia.

    Science.gov (United States)

    Yang, Zhiman; Guo, Rongbo; Xu, Xiaohui; Wang, Lin; Dai, Meng

    2016-09-01

    Using batch and repeated batch cultivations, this study investigated the effects of bioaugmentation with enriched microbial consortia (named as EMC) on methane production from effluents of hydrogen-producing stage of potato slurry, as well as on the indigenous bacterial community. The results demonstrated that the improved methane production and shift of the indigenous bacterial community structure were dependent on the EMC/sludge ratio and bioaugmentation patterns. The methane yield and production rate in repeated batch bioaugmentation pattern of EMC were, respectively, average 15% and 10% higher than in one-time bioaugmentation pattern of EMC. DNA-sequencing approach showed that the enhanced methane production in the repeated batch bioaugmentation pattern of EMC mainly resulted from the enriched iron-reducing bacteria and the persistence of the introduced Syntrophomonas, which led to a rapid degradation of individual VFAs to methane. The findings contributed to understanding the correlation between the bioaugmentation of microbial consortia, community shift, and methane production.

  1. Spatio-temporal patterns of leptospirosis in Thailand: is flooding a risk factor?

    Science.gov (United States)

    Suwanpakdee, S; Kaewkungwal, J; White, L J; Asensio, N; Ratanakorn, P; Singhasivanon, P; Day, N P J; Pan-Ngum, W

    2015-07-01

    We studied the temporal and spatial patterns of leptospirosis, its association with flooding and animal census data in Thailand. Flood data from 2010 to 2012 were extracted from spatial information taken from satellite images. The incidence rate ratio (IRR) was used to determine the relationship between spatio-temporal flooding patterns and the number of human leptospirosis cases. In addition, the area of flood coverage, duration of waterlogging, time lags between flood events, and a number of potential animal reservoirs were considered in a sub-analysis. There was no significant temporal trend of leptospirosis over the study period. Statistical analysis showed an inconsistent relationship between IRR and flooding across years and regions. Spatially, leptospirosis occurred repeatedly and predominantly in northeastern Thailand. Our findings suggest that flooding is less influential in leptospirosis transmission than previously assumed. High incidence of the disease in the northeastern region is explained by the fact that agriculture and animal farming are important economic activities in this area. The periodic rise and fall of reported leptospirosis cases over time might be explained by seasonal exposure from rice farming activities performed during the rainy season when flood events often occur. We conclude that leptospirosis remains an occupational disease in Thailand.

  2. Melatonin affects the temporal pattern of vocal signatures in birds.

    Science.gov (United States)

    Derégnaucourt, Sébastien; Saar, Sigal; Gahr, Manfred

    2012-10-01

    In humans and other animals, melatonin is involved in the control of circadian biological rhythms. Here, we show that melatonin affects the temporal pattern of behavioral sequences in a noncircadian manner. The zebra finch (Taeniopygia guttata) song and the crow of the Japanese quail (Coturnix japonica) are courtship vocalizations composed of a stereotyped sequence of syllables. The zebra finch song is learned from conspecifics during infancy, whereas the Japanese quail crow develops normally without auditory input. We recorded and analyzed the complete vocal activity of adult birds of both species kept in social isolation for several weeks. In both species, we observed a shortening of signal duration following the transfer from a light-dark (LD) cycle to constant light (LL), a condition known to abolish melatonin production and to disrupt circadian rhythmicity. This effect was reversible because signal duration increased when the photoperiod was returned to the previous LD schedule. We then tested whether this effect was directly related to melatonin by removal of the pineal gland, which is the main production site of circulating melatonin. A shortening of the song duration was observed following pinealectomy in LD. Likewise, melatonin treatment induced changes in the temporal structure of the song. In a song learning experiment, young pinealectomized finches and young finches raised in LL failed to copy the temporal pattern of their tutor's song. Taken together, these results suggest that melatonin is involved in the control of motor timing of noncircadian behavioral sequences through an evolutionary conserved neuroendocrine pathway. © 2012 John Wiley & Sons A/S.

  3. Intra-session repeatability of lower limb muscles activation pattern during pedaling.

    Science.gov (United States)

    Dorel, Sylvain; Couturier, Antoine; Hug, François

    2008-10-01

    Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

  4. Temporal patterns in adult salmon migration timing across southeast Alaska

    Science.gov (United States)

    Kovach, Ryan P.; Ellison, Stephen; Pyare, Sanjay; Tallmon, David

    2015-01-01

    Pacific salmon migration timing can drive population productivity, ecosystem dynamics, and human harvest. Nevertheless, little is known about long-term variation in salmon migration timing for multiple species across broad regions. We used long-term data for five Pacific salmon species throughout rapidly warming southeast Alaska to describe long-term changes in salmon migration timing, interannual phenological synchrony, relationships between climatic variation and migratory timing, and to test whether long-term changes in migration timing are related to glaciation in headwater streams. Temporal changes in the median date of salmon migration timing varied widely across species. Most sockeye populations are migrating later over time (11 of 14), but pink, chum, and especially coho populations are migrating earlier than they did historically (16 of 19 combined). Temporal trends in duration and interannual variation in migration timing were highly variable across species and populations. The greatest temporal shifts in the median date of migration timing were correlated with decreases in the duration of migration timing, suggestive of a loss of phenotypic variation due to natural selection. Pairwise interannual correlations in migration timing varied widely but were generally positive, providing evidence for weak region-wide phenological synchrony. This synchrony is likely a function of climatic variation, as interannual variation in migration timing was related to climatic phenomenon operating at large- (Pacific decadal oscillation), moderate- (sea surface temperature), and local-scales (precipitation). Surprisingly, the presence or the absence of glaciers within a watershed was unrelated to long-term shifts in phenology. Overall, there was extensive heterogeneity in long-term patterns of migration timing throughout this climatically and geographically complex region, highlighting that future climatic change will likely have widely divergent impacts on salmon

  5. Spatio-temporal point pattern analysis on Wenchuan strong earthquake

    Institute of Scientific and Technical Information of China (English)

    PeijianShi; Jie Liu; ZhenYang

    2009-01-01

    For exploring the aftershock occurrence process of the 2008 Wenchuan strong earthquake, the spatio-temporal point pattern analysis method is employed to study the sequences of aftershocks with magnitude M≥4.0, M≥4.5, and M≥5.0. It is found that these data exhibit the spatio-temporal clustering on a certain distance scale and on a certain time scale. In particular, the space-time interaction obviously strengthens when the distance is less than 60 km and the time is less than 260 h for the first two aftershock sequences; however, it becomes strong when the distance scale is less than 80 km and the time scale is less than 150 h for the last aftershock sequence. The completely spatial randomness analysis on the data regardless of time component shows that the spatial clustering of the aftershocks gradually strengthens on the condition that the distance is less than 60 km. The results are valuable for exploring the occurrence rules of the Wenchuan strong earthquake and for predicting the aftershocks.

  6. Uncovering Urban Temporal Patterns from Geo-Tagged Photography

    Science.gov (United States)

    Paldino, Silvia; Kondor, Dániel; Sobolevsky, Stanislav; González, Marta C.; Ratti, Carlo

    2016-01-01

    We live in a world where digital trails of different forms of human activities compose big urban data, allowing us to detect many aspects of how people experience the city in which they live or come to visit. In this study we propose to enhance urban planning by taking into a consideration individual preferences using information from an unconventional big data source: dataset of geo-tagged photographs that people take in cities which we then use as a measure of urban attractiveness. We discover and compare a temporal behavior of residents and visitors in ten most photographed cities in the world. Looking at the periodicity in urban attractiveness, the results show that the strongest periodic patterns for visitors are usually weekly or monthly. Moreover, by dividing cities into two groups based on which continent they belong to (i.e., North America or Europe), it can be concluded that unlike European cities, behavior of visitors in the US cities in general is similar to the behavior of their residents. Finally, we apply two indices, called “dilatation attractiveness index” and “dilatation index”, to our dataset which tell us the spatial and temporal attractiveness pulsations in the city. The proposed methodology is not only important for urban planning, but also does support various business and public stakeholder decision processes, concentrated for example around the question how to attract more visitors to the city or estimate the impact of special events organized there. PMID:27935979

  7. Classifying Human Body Acceleration Patterns Using a Hierarchical Temporal Memory

    Science.gov (United States)

    Sassi, Federico; Ascari, Luca; Cagnoni, Stefano

    This paper introduces a novel approach to the detection of human body movements during daily life. With the sole use of one wearable wireless triaxial accelerometer attached to one's chest, this approach aims at classifying raw acceleration data robustly, to detect many common human behaviors without requiring any specific a-priori knowledge about movements. The proposed approach consists of feeding sensory data into a specifically trained Hierarchical Temporal Memory (HTM) to extract invariant spatial-temporal patterns that characterize different body movements. The HTM output is then classified using a Support Vector Machine (SVM) into different categories. The performance of this new HTM+SVM combination is compared with a single SVM using real-word data corresponding to movements like "standing", "walking", "jumping" and "falling", acquired from a group of different people. Experimental results show that the HTM+SVM approach can detect behaviors with very high accuracy and is more robust, with respect to noise, than a classifier based solely on SVMs.

  8. Temporal prediction of epidemic patterns in community networks

    CERN Document Server

    Peng, Xiao-Long; Xu, Xin-Jian; Fu, Xinchu

    2013-01-01

    Most previous studies of epidemic dynamics on complex networks suppose that the disease will eventually stabilize at either a disease-free state or an endemic one. In reality, however, some epidemics always exhibit sporadic and recurrent behaviour in one region because of the invasion from an endemic population elsewhere. In this paper we address this issue and study a susceptible-infected-susceptible epidemiological model on a network consisting of two communities, where the disease is endemic in one community but alternates between outbreaks and extinctions in the other. We provide a detailed characterization of the temporal dynamics of epidemic patterns in the latter community. In particular, we investigate the time duration of both outbreak and extinction, and the time interval between two consecutive inter-community infections, as well as their frequency distributions. Based on the mean-field theory, we theoretically analyze these three timescales and their dependence on the average node degree of each c...

  9. Global Patterns of Turbulence and Diapycnal Mixing from CTD-Chipods on the Global Repeat Hydrography Program

    Science.gov (United States)

    Pickering, A.; Nash, J. D.; Moum, J. N.; MacKinnon, J. A.

    2016-02-01

    With an aim to quantify global patterns of ocean mixing, we have developed the CTD-chipod, an instrument that measures the turbulent dissipation rate of temperature variance from standard shipboard CTD. First, turbulent diffusivities and turbulent dissipation rate inferred from the CTD-chipod are compared to that from traditional turbulence profilers with shear probes, suggesting the method does not suffer from significant bias. CTD-chipods have now been deployed on several of the global repeat hydrography program cruises, including the complete P16 line from 60S to 55N in the Pacific. Here we discuss broad patterns of mixing from these observations, as well as focusing on some specific interesting features. In particular, a section of higher resolution sampling across the equator from 5S to 5N in the Pacific suggests elevated abyssal mixing in that region. This and other patterns will be examined in relation to large-scale patterns of stratification, velocity, and shear. The observations will also be compared to other common parameterizations of mixing from shear and strain. These chipod measurements are a step towards constraining the spatial and temporal patterns of turbulent mixing across the world's oceans, in order to better understand dissipative mechanisms and their role in ocean dynamics.

  10. Quantitative Effects of Repeated Muscle Vibrations on Gait Pattern in a 5-Year-Old Child with Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Filippo Camerota

    2011-01-01

    Full Text Available Objective. To investigate quantitatively and objectively the effects of repeated muscle vibration (rMV of triceps surae on the gait pattern in a 5-year-old patient with Cerebral Palsy with equinus foot deformity due to calf spasticity. Methods. The patient was assessed before and one month after the rMV treatment using Gait Analysis. Results. rMV had positive effects on the patient's gait pattern, as for spatio-temporal parameters (the stance duration and the step length increased their values after the treatment and kinematics. The pelvic tilt reduced its anteversion and the hip reduced the high flexion evidenced at baseline; the knee and the ankle gained a more physiological pattern bilaterally. The Gillette Gait Index showed a significant reduction of its value bilaterally, representing a global improvement of the child's gait pattern. Conclusions. The rMV technique seems to be an effective option for the gait pattern improvement in CP, which can be used also in very young patient. Significant improvements were displayed in terms of kinematics at all lower limb joints, not only at the joint directly involved by the treatment (i.e., ankle and knee joints but also at proximal joints (i.e., pelvis and hip joint.

  11. Differentiation of bacterial colonies and temporal growth patterns using hyperspectral imaging

    Science.gov (United States)

    Mehrübeoglu, Mehrube; Buck, Gregory W.; Livingston, Daniel W.

    2014-09-01

    Detection and identification of bacteria are important for health and safety. Hyperspectral imaging offers the potential to capture unique spectral patterns and spatial information from bacteria which can then be used to detect and differentiate bacterial species. Here, hyperspectral imaging has been used to characterize different bacterial colonies and investigate their growth over time. Six bacterial species (Pseudomonas fluorescens, Escherichia coli, Serratia marcescens, Salmonella enterica, Staphylococcus aureus, Enterobacter aerogenes) were grown on tryptic soy agar plates. Hyperspectral data were acquired immediately after, 24 hours after, and 96 hours after incubation. Spectral signatures from bacterial colonies demonstrated repeatable measurements for five out of six species. Spatial variations as well as changes in spectral signatures were observed across temporal measurements within and among species at multiple wavelengths due to strengthening or weakening reflectance signals from growing bacterial colonies based on their pigmentation. Between-class differences and within-class similarities were the most prominent in hyperspectral data collected 96 hours after incubation.

  12. Encoding of sound localization cues by an identified auditory interneuron: effects of stimulus temporal pattern.

    Science.gov (United States)

    Samson, Annie-Hélène; Pollack, Gerald S

    2002-11-01

    An important cue for sound localization is binaural comparison of stimulus intensity. Two features of neuronal responses, response strength, i.e., spike count and/or rate, and response latency, vary with stimulus intensity, and binaural comparison of either or both might underlie localization. Previous studies at the receptor-neuron level showed that these response features are affected by the stimulus temporal pattern. When sounds are repeated rapidly, as occurs in many natural sounds, response strength decreases and latency increases, resulting in altered coding of localization cues. In this study we analyze binaural cues for sound localization at the level of an identified pair of interneurons (the left and right AN2) in the cricket auditory system, with emphasis on the effects of stimulus temporal pattern on binaural response differences. AN2 spike count decreases with rapidly repeated stimulation and latency increases. Both effects depend on stimulus intensity. Because of the difference in intensity at the two ears, binaural differences in spike count and latency change as stimulation continues. The binaural difference in spike count decreases, whereas the difference in latency increases. The proportional changes in response strength and in latency are greater at the interneuron level than at the receptor level, suggesting that factors in addition to decrement of receptor responses are involved. Intracellular recordings reveal that a slowly building, long-lasting hyperpolarization is established in AN2. At the same time, the level of depolarization reached during the excitatory postsynaptic potential (EPSP) resulting from each sound stimulus decreases. Neither these effects on membrane potential nor the changes in spiking response are accounted for by contralateral inhibition. Based on comparison of our results with earlier behavioral experiments, it is unlikely that crickets use the binaural difference in latency of AN2 responses as the main cue for

  13. Spatial and temporal patterns of eastern Australia subtropical coral communities.

    Directory of Open Access Journals (Sweden)

    Steven J Dalton

    Full Text Available Despite increases in the frequency and intensity of disturbances on coral reefs over the past few decades, the response of subtropical coral assemblages to climate change is poorly understood. To address this knowledge gap on Australian reefs and provide a baseline for future comparisons, we quantified spatial (10-100's of kilometres and temporal (decadal patterns of benthic assemblages across a latitudinal gradient along the east Australian coastline (23.5° S to 31.5° S. Benthic community composition was quantified at six locations from the southern Great Barrier Reef, Queensland (Heron Reef, 23.5° S, 152° E to northern New South Wales (31° S, 153.1° E and at Lord Howe Island (31.5° S, 159.1° E. Our results indicate significant latitudinal differences in benthic assemblages, while community composition at some sites was more similar to those hundreds of kilometres away than to that of neighbouring reefs. A general trend was observed with decreasing cover of Acroporidae with increasing latitude, corresponding with an increasing cover of Pocilloporidae and Dendrophylliidae. Heron Reef comprised a high proportion of Acropora corals (43% total coral cover and coralline algae (44%. In contrast, high-latitude reefs were dominated by mixed coral assemblages (0-52% and high macroalgal cover (16-27%. Decadal comparisons of high-latitude reefs showed regional stability of benthic assemblages (9 out of 11 assemblages remained stable at > 75% similarity, during a period of warming oceans (0.15-0.24°C per decade. Such temporal stability suggests that eastern Australian subtropical communities may be more resistant than tropical reef communities that have experienced assembly shifts caused by perturbations associated with recent global climate change. Despite the clear differences in the structure of coral assemblages evident in our spatial surveys, we suggest that the temporal stability of high-latitude reefs may provide a limited refuge for

  14. Spatio-temporal correlation of vegetation and temperature patterns

    Science.gov (United States)

    Coppola, R.; D'Emilio, M.; Imbrenda, V.; Lanfredi, M.; Macchiato, M.; Simoniello, T.

    2010-05-01

    Temperature is one of the variables largely influencing vegetation species distributions (biogeographical regions) and plant development (phenological cycle). Anomalies in temperature regional patterns and in microclimate conditions induce modifications in vegetation cover phenology; in particular in European regions, the responsiveness of vegetation to temperature increase is greater in warmer Mediterranean countries. In order to assess the spatial arrangement and the temporal variability of vegetation and temperature patterns in a typical Mediterranean environment, we investigated monthly NDVI-AVHRR and temperature time series over Southern Italy, core of Mediterranean Basin. Temperature data, obtained from 35 meteoclimatic stations, were rasterized by adopting a combined deterministic-stochastic procedure we suitably implemented for the investigated region in order to obtain spatial data comparable with NDVI maps. For the period 1996-1998, monthly MVC data were clusterized on annual basis by means of a classification procedure to aggregate areas with similar phenological cycles. The same procedure was adopted to jointly evaluate temperature and vegetation profiles and identify areas having similar phenological and temperature patterns. The comparison of the identified clusters showed that the classification obtained with and without temperature profiles are very similar enhancing the strong role of this variable in vegetation development. Some exceptions in the cluster arrangement are due to local anomalies in vegetation distribution, such as forest fires. In order to spatially analyze such a dependence, we also elaborated a time correlation map for each year and we found that the correlation patterns are persistent on the year basis and generally follow the land cover distributions. The correlation values are very high and positive for the forested mountainous areas (R>0.8), whereas they are negative for plan coastal areas (R<-0.8). Low correlation values (R

  15. Unravelling spatio-temporal evapotranspiration patterns in topographically complex landscapes

    Science.gov (United States)

    Metzen, Daniel; Sheridan, Gary; Nyman, Petter; Lane, Patrick

    2016-04-01

    Vegetation co-evolves with soils and topography under a given long-term climatic forcing. Previous studies demonstrated a strong eco-hydrologic feedback between topography, vegetation and energy and water fluxes. Slope orientation (aspect and gradient) alter the magnitude of incoming solar radiation resulting in larger evaporative losses and less water availability on equator-facing slopes. Furthermore, non-local water inputs from upslope areas potentially contribute to available water at downslope positions. The combined effect of slope orientation and drainage position creates complex spatial patterns in biological productivity and pedogenesis, which in turn alter the local hydrology. In complex upland landscapes, topographic alteration of incoming radiation can cause substantial aridity index (ratio of potential evapotranspiration to precipitation) variations over small spatial extents. Most of the upland forests in south-east Australia are located in an aridity index (AI) range of 1-2, around the energy limited to water limited boundary, where forested systems are expected to be most sensitive to AI changes. In this research we aim to improve the fundamental understanding of spatio-temporal evolution of evapotranspiration (ET) patterns in complex terrain, accounting for local topographic effects on system properties (e.g. soil depth, sapwood area, leaf area) and variation in energy and water exchange processes due to slope orientation and drainage position. Six measurement plots were set-up in a mixed species eucalypt forest on a polar and equatorial-facing hillslope (AI ˜1.3 vs. 1.8) at varying drainage position (ridge, mid-slope, gully), while minimizing variations in other factors, e.g. geology and weather patterns. Sap flow, soil water content, incoming solar radiation and throughfall were continuously monitored at field sites spanning a wide range of soil depth (0.5 - >3m), maximum tree heights (17 - 51m) and LAI (1.2 - 4.6). Site-specific response curves

  16. Temporal patterns of diversification across global cichlid biodiversity (Acanthomorpha: Cichlidae.

    Directory of Open Access Journals (Sweden)

    Caleb D McMahan

    Full Text Available The contrasting distribution of species diversity across the major lineages of cichlids makes them an ideal group for investigating macroevolutionary processes. In this study, we investigate whether different rates of diversification may explain the disparity in species richness across cichlid lineages globally. We present the most taxonomically robust time-calibrated hypothesis of cichlid evolutionary relationships to date. We then utilize this temporal framework to investigate whether both species-rich and depauperate lineages are associated with rapid shifts in diversification rates and if exceptional species richness can be explained by clade age alone. A single significant rapid rate shift increase is detected within the evolutionary history of the African subfamily Pseudocrenilabrinae, which includes the haplochromins of the East African Great Lakes. Several lineages from the subfamilies Pseudocrenilabrinae (Australotilapiini, Oreochromini and Cichlinae (Heroini exhibit exceptional species richness given their clade age, a net rate of diversification, and relative rates of extinction, indicating that clade age alone is not a sufficient explanation for their increased diversity. Our results indicate that the Neotropical Cichlinae includes lineages that have not experienced a significant rapid burst in diversification when compared to certain African lineages (rift lake. Neotropical cichlids have remained comparatively understudied with regard to macroevolutionary patterns relative to African lineages, and our results indicate that of Neotropical lineages, the tribe Heroini may have an elevated rate of diversification in contrast to other Neotropical cichlids. These findings provide insight into our understanding of the diversification patterns across taxonomically disparate lineages in this diverse clade of freshwater fishes and one of the most species-rich families of vertebrates.

  17. Temporal patterns of diversification across global cichlid biodiversity (Acanthomorpha: Cichlidae).

    Science.gov (United States)

    McMahan, Caleb D; Chakrabarty, Prosanta; Sparks, John S; Smith, W M Leo; Davis, Matthew P

    2013-01-01

    The contrasting distribution of species diversity across the major lineages of cichlids makes them an ideal group for investigating macroevolutionary processes. In this study, we investigate whether different rates of diversification may explain the disparity in species richness across cichlid lineages globally. We present the most taxonomically robust time-calibrated hypothesis of cichlid evolutionary relationships to date. We then utilize this temporal framework to investigate whether both species-rich and depauperate lineages are associated with rapid shifts in diversification rates and if exceptional species richness can be explained by clade age alone. A single significant rapid rate shift increase is detected within the evolutionary history of the African subfamily Pseudocrenilabrinae, which includes the haplochromins of the East African Great Lakes. Several lineages from the subfamilies Pseudocrenilabrinae (Australotilapiini, Oreochromini) and Cichlinae (Heroini) exhibit exceptional species richness given their clade age, a net rate of diversification, and relative rates of extinction, indicating that clade age alone is not a sufficient explanation for their increased diversity. Our results indicate that the Neotropical Cichlinae includes lineages that have not experienced a significant rapid burst in diversification when compared to certain African lineages (rift lake). Neotropical cichlids have remained comparatively understudied with regard to macroevolutionary patterns relative to African lineages, and our results indicate that of Neotropical lineages, the tribe Heroini may have an elevated rate of diversification in contrast to other Neotropical cichlids. These findings provide insight into our understanding of the diversification patterns across taxonomically disparate lineages in this diverse clade of freshwater fishes and one of the most species-rich families of vertebrates.

  18. Analysis of Tandem Repeat Patterns in Nlrc4 using a Motif Model

    Directory of Open Access Journals (Sweden)

    Sim-Hui Tee

    2012-12-01

    Full Text Available Exponential accumulation of biological data requires computer scientists and bioinformaticians to improve the efficiency of computer algorithms and databases. The recent advancement of computational tools has boosted the processing capacity of enormous volume of genetic data. This research applied a computational approach to analyze the tandem repeat patterns in Nlrc4 gene. Because the protein product of Nlrc4 gene is important in detecting pathogen and triggering subsequent immune responses, the results of this genetic analysis is essential for the understanding of the genetic characteristics of Nlrc4. The study on the distribution of tandem repeats may provide insights for drug design catered for the Nlrc4-implicated diseases.

  19. Climate drives temporal replacement and nested-resultant richness patterns of Scottish coastal vegetation

    DEFF Research Database (Denmark)

    Lewis, Rob; Marrs, Rob H.; Pakeman, Robin J.

    2016-01-01

    Beta diversity quantifies spatial and/or temporal variation in species composition. It is comprised of two distinct components, species replacement and nestedness, which derive from opposing ecological processes. Using Scotland as a case study and a β-diversity partitioning framework, we...... contribution of each on temporal replacement and nestedness patterns. Temporal β-diversity patterns were reasonably well explained by climate change but weakly explained by changes in landscape-scale heterogeneity. Climate was shown to have a greater influence on temporal nestedness than replacement patterns...... investigate temporal replacement and nestedness patterns of coastal grassland species over a 34-yr time period. We aim to 1) understand the influence of two potentially pivotal processes (climate and land-use changes) on landscape-scale (5 × 5 km) temporal replacement and nestedness patterns, and 2...

  20. The temporal patterns of disease severity and prevalence in schistosomiasis

    Energy Technology Data Exchange (ETDEWEB)

    Ciddio, Manuela; Gatto, Marino, E-mail: marino.gatto@polimi.it; Casagrandi, Renato, E-mail: renato.casagrandi@polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Via Ponzio 34/5, 20133 Milano (Italy); Mari, Lorenzo [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Via Ponzio 34/5, 20133 Milano (Italy); Laboratory of Ecohydrology, ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, Station 2, 1015 Lausanne (Switzerland); Rinaldo, Andrea [Laboratory of Ecohydrology, ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, Station 2, 1015 Lausanne (Switzerland); Dipartimento di Ingegneria Civile, Edile ed Ambientale, Università di Padova, Via Loredan 20, 35131 Padova (Italy)

    2015-03-15

    Schistosomiasis is one of the most widespread public health problems in the world. In this work, we introduce an eco-epidemiological model for its transmission and dynamics with the purpose of explaining both intra- and inter-annual fluctuations of disease severity and prevalence. The model takes the form of a system of nonlinear differential equations that incorporate biological complexity associated with schistosome's life cycle, including a prepatent period in snails (i.e., the time between initial infection and onset of infectiousness). Nonlinear analysis is used to explore the parametric conditions that produce different temporal patterns (stationary, endemic, periodic, and chaotic). For the time-invariant model, we identify a transcritical and a Hopf bifurcation in the space of the human and snail infection parameters. The first corresponds to the occurrence of an endemic equilibrium, while the latter marks the transition to interannual periodic oscillations. We then investigate a more realistic time-varying model in which fertility of the intermediate host population is assumed to seasonally vary. We show that seasonality can give rise to a cascade of period-doubling bifurcations leading to chaos for larger, though realistic, values of the amplitude of the seasonal variation of fertility.

  1. The temporal patterns of disease severity and prevalence in schistosomiasis

    Science.gov (United States)

    Ciddio, Manuela; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea; Casagrandi, Renato

    2015-03-01

    Schistosomiasis is one of the most widespread public health problems in the world. In this work, we introduce an eco-epidemiological model for its transmission and dynamics with the purpose of explaining both intra- and inter-annual fluctuations of disease severity and prevalence. The model takes the form of a system of nonlinear differential equations that incorporate biological complexity associated with schistosome's life cycle, including a prepatent period in snails (i.e., the time between initial infection and onset of infectiousness). Nonlinear analysis is used to explore the parametric conditions that produce different temporal patterns (stationary, endemic, periodic, and chaotic). For the time-invariant model, we identify a transcritical and a Hopf bifurcation in the space of the human and snail infection parameters. The first corresponds to the occurrence of an endemic equilibrium, while the latter marks the transition to interannual periodic oscillations. We then investigate a more realistic time-varying model in which fertility of the intermediate host population is assumed to seasonally vary. We show that seasonality can give rise to a cascade of period-doubling bifurcations leading to chaos for larger, though realistic, values of the amplitude of the seasonal variation of fertility.

  2. Spatio-temporal patterns of precipitation in Serbia

    Science.gov (United States)

    Gocic, Milan; Trajkovic, Slavisa

    2014-08-01

    The monthly precipitation data from 29 synoptic stations for the period 1946-2012 were analyzed using a number of different multivariate statistical analysis methods to investigate the spatial variability and temporal patterns of precipitation across Serbia. R-mode principal component analysis was used to study the spatial variability of the precipitation. Three distinct sub-regions were identified by applying the agglomerative hierarchical cluster analysis to the two component scores: C1 includes the north and the northeast part of Serbia, while C2 includes the western part of Central Serbia and southwestern part of Serbia and C3 includes central, east, south and southeast part of Serbia. The analysis of the identified sub-regions indicated that the monthly and seasonal precipitation in sub-region C2 had the values above average, while C1 and C3 had the precipitation values under average. The analysis of the linear trend of the mean annual precipitation showed an increasing trend for the stations located in Serbia and three sub-regions. From the result of this analysis, one can plan land use, water resources and agricultural production in the region.

  3. Air pollution in Accra neighborhoods: spatial, socioeconomic, and temporal patterns.

    Science.gov (United States)

    Dionisio, Kathie L; Arku, Raphael E; Hughes, Allison F; Vallarino, Jose; Carmichael, Heather; Spengler, John D; Agyei-Mensah, Samuel; Ezzati, Majid

    2010-04-01

    This study examined the spatial, socioeconomic status (SES), and temporal patterns of ambient air pollution in Accra, Ghana. Over 22 months, integrated and continuous rooftop particulate matter (PM) monitors were placed at a total of 11 residential or roadside monitoring sites in four neighborhoods of varying SES and biomass fuel use. PM concentrations were highest in late December and January, due to dust blown from the Sahara. Excluding this period, annual PM(2.5) ranged from 39 to 53 microg/m(3) at roadside sites and 30 to 70 microg/m(3) at residential sites; mean annual PM(10) ranged from 80 to 108 microg/m(3) at roadside sites and 57 to 106 microg/m(3) at residential sites. The low-income and densely populated neighborhood of Jamestown/Ushertown had the single highest residential PM concentration. There was less difference across traffic sites. Daily PM increased at all sites at daybreak, followed by a mid-day peak at some sites, and a more spread-out evening peak at all sites. Average carbon monoxide concentrations at different sites and seasons ranged from 7 to 55 ppm, and were generally lower at residential sites than at traffic sites. The results show that PM in these four neighborhoods is substantially higher than the WHO Air Quality Guidelines and in some cases even higher than the WHO Interim Target 1, with the highest pollution in the poorest neighborhood.

  4. Lesser Neural Pattern Similarity across Repeated Tests Is Associated with Better Long-Term Memory Retention.

    Science.gov (United States)

    Karlsson Wirebring, Linnea; Wiklund-Hörnqvist, Carola; Eriksson, Johan; Andersson, Micael; Jonsson, Bert; Nyberg, Lars

    2015-07-01

    Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability--the altering or adding of underlying memory representations. Human participants studied 60 Swahili-Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgotten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. Repeated testing is known to produce superior long-term retention of the to-be-learned material compared with repeated encoding and other learning techniques, much because it fosters repeated memory retrieval. This study demonstrates that repeated memory

  5. Long Term Memory for Noise: Evidence of Robust Encoding of Very Short Temporal Acoustic Patterns.

    Science.gov (United States)

    Viswanathan, Jayalakshmi; Rémy, Florence; Bacon-Macé, Nadège; Thorpe, Simon J

    2016-01-01

    Recent research has demonstrated that humans are able to implicitly encode and retain repeating patterns in meaningless auditory noise. Our study aimed at testing the robustness of long-term implicit recognition memory for these learned patterns. Participants performed a cyclic/non-cyclic discrimination task, during which they were presented with either 1-s cyclic noises (CNs) (the two halves of the noise were identical) or 1-s plain random noises (Ns). Among CNs and Ns presented once, target CNs were implicitly presented multiple times within a block, and implicit recognition of these target CNs was tested 4 weeks later using a similar cyclic/non-cyclic discrimination task. Furthermore, robustness of implicit recognition memory was tested by presenting participants with looped (shifting the origin) and scrambled (chopping sounds into 10- and 20-ms bits before shuffling) versions of the target CNs. We found that participants had robust implicit recognition memory for learned noise patterns after 4 weeks, right from the first presentation. Additionally, this memory was remarkably resistant to acoustic transformations, such as looping and scrambling of the sounds. Finally, implicit recognition of sounds was dependent on participant's discrimination performance during learning. Our findings suggest that meaningless temporal features as short as 10 ms can be implicitly stored in long-term auditory memory. Moreover, successful encoding and storage of such fine features may vary between participants, possibly depending on individual attention and auditory discrimination abilities. Significance Statement Meaningless auditory patterns could be implicitly encoded and stored in long-term memory.Acoustic transformations of learned meaningless patterns could be implicitly recognized after 4 weeks.Implicit long-term memories can be formed for meaningless auditory features as short as 10 ms.Successful encoding and long-term implicit recognition of meaningless patterns may

  6. Long term memory for noise: evidence of robust encoding of very short temporal acoustic patterns.

    Directory of Open Access Journals (Sweden)

    Jayalakshmi Viswanathan

    2016-11-01

    Full Text Available Recent research has demonstrated that humans are able to implicitly encode and retain repeating patterns in meaningless auditory noise. Our study aimed at testing the robustness of long-term implicit recognition memory for these learned patterns. Participants performed a cyclic/non-cyclic discrimination task, during which they were presented with either 1-s cyclic noises (CNs (the two halves of the noise were identical or 1-s plain random noises (Ns. Among CNs and Ns presented once, target CNs were implicitly presented multiple times within a block, and implicit recognition of these target CNs was tested 4 weeks later using a similar cyclic/non-cyclic discrimination task. Furthermore, robustness of implicit recognition memory was tested by presenting participants with looped (shifting the origin and scrambled (chopping sounds into 10- and 20-ms bits before shuffling versions of the target CNs. We found that participants had robust implicit recognition memory for learned noise patterns after 4 weeks, right from the first presentation. Additionally, this memory was remarkably resistant to acoustic transformations, such as looping and scrambling of the sounds. Finally, implicit recognition of sounds was dependent on participant’s discrimination performance during learning. Our findings suggest that meaningless temporal features as short as 10 ms can be implicitly stored in long-term auditory memory. Moreover, successful encoding and storage of such fine features may vary between participants, possibly depending on individual attention and auditory discrimination abilities.

  7. The Incidence and Temporal Patterning of Insomnia: a Pilot Study

    Science.gov (United States)

    Perlis, Michael; Phillips, Cindy; Gehrman, Philip R.; Pigeon, Wilfred; Matteson, Sara; Jungquist, Carla

    2014-01-01

    To date very little research has been conducted on night-to-night variability in the incidence of insomnia. Unclear from prior research is whether subjects with Primary Insomnia (PI) exhibit good sleep (or better than average sleep) on some interval basis. In the present study, pilot data are provided on 1) the frequency with which “good sleep” occurs in subjects with PI and 2) whether these events occur in a non-random manner. 10 PI subjects participated in this “naturalistic” study. All subjects completed daily sleep diaries for a minimum of 20 days. None of the subjects received treatment for their insomnia during the monitoring period. The night-tonight data were evaluated by typing each night’s sleep as “Good” or “Bad” and then by determining the number of bad nights that occurred prior to a good night for each subject. Good and bad nights were typed in two ways: 1. using a ≥ 85% cutoff and 2. using a better than the individual’s mean sleep efficiency (idiographic cutoff). Subjects exhibited good sleep on between 29% (> 85% criteria) and 55% (idiographic criteria) of the nights evaluated. The temporal patterning analysis (based on a idiographic cutoff) revealed that better than average sleep most frequently occurred (> 89% of instances) following one to three night’s of poor sleep. These data suggests that insomnia severity may be mediated/moderated by sleep homeostasis and that the homeostat, or input to the homeostat, may be abnormal in patients with Primary Insomnia. PMID:19912510

  8. Spatial and temporal patterns of subtidal and intertidal crabs excursions

    Science.gov (United States)

    Silva, A. C. F.; Boaventura, D. M.; Thompson, R. C.; Hawkins, S. J.

    2014-01-01

    Highly mobile predators such as fish and crabs are known to migrate from the subtidal zone to forage in the intertidal zone at high-tide. The extent and variation of these habitat linking movements along the vertical shore gradient have not been examined before for several species simultaneously, hence not accounting for species interactions. Here, the foraging excursions of Carcinus maenas (L.), Necora puber (Linnaeus, 1767) and Cancer pagurus (Linnaeus, 1758) were assessed in a one-year mark-recapture study on two replicated rocky shores in southwest U.K. A comparison between the abundance of individuals present on the shore at high-tide with those present in refuges exposed at low-tide indicated considerable intertidal migration by all species, showing strong linkage between subtidal and intertidal habitats. Estimates of population size based on recapture of marked individuals indicated that an average of ~ 4000 individuals combined for the three crab species, can be present on the shore during one tidal cycle. There was also a high fidelity of individuals and species to particular shore levels. Underlying mechanisms for these spatial patterns such as prey availability and agonistic interactions are discussed. Survival rates were estimated using the Cormack-Jolly-Seber model from multi-recapture analysis and found to be considerably high with a minimum of 30% for all species. Growth rates were found to vary intraspecifically with size and between seasons. Understanding the temporal and spatial variations in predation pressure by crabs on rocky shores is dependent on knowing who, when and how many of these commercially important crab species depend on intertidal foraging. Previous studies have shown that the diet of these species is strongly based on intertidal prey including key species such as limpets; hence intertidal crab migration could be associated with considerable impacts on intertidal assemblages.

  9. Spatial and temporal patterns of malaria incidence in Mozambique

    Directory of Open Access Journals (Sweden)

    Zacarias Orlando P

    2011-07-01

    Full Text Available Abstract Background The objective of this study is to analyze the spatial and temporal patterns of malaria incidence as to determine the means by which climatic factors such as temperature, rainfall and humidity affect its distribution in Maputo province, Mozambique. Methods This study presents a model of malaria that evolves in space and time in Maputo province-Mozambique, over a ten years period (1999-2008. The model incorporates malaria cases and their relation to environmental variables. Due to incompleteness of climatic data, a multiple imputation technique is employed. Additionally, the whole province is interpolated through a Gaussian process. This method overcomes the misalignment problem of environmental variables (available at meteorological stations - points and malaria cases (available as aggregates for every district - area. Markov Chain Monte Carlo (MCMC methods are used to obtain posterior inference and Deviance Information Criteria (DIC to perform model comparison. Results A Bayesian model with interaction terms was found to be the best fitted model. Malaria incidence was associated to humidity and maximum temperature. Malaria risk increased with maximum temperature over 28°C (relative risk (RR of 0.0060 and 95% Bayesian credible interval (CI of 0.00033-0.0095 and humidity (relative risk (RR of 0.00741 and 95% Bayesian CI 0.005141-0.0093. The results would suggest that additional non-climatic factors including socio-economic status, elevation, etc. also influence malaria transmission in Mozambique. Conclusions These results demonstrate the potential of climate predictors particularly, humidity and maximum temperature in explaining malaria incidence risk for the studied period in Maputo province. Smoothed maps obtained as monthly average of malaria incidence allowed to visualize months of initial and peak transmission. They also illustrate a variation on malaria incidence risk that might not be related to climatic factors

  10. Soil wetting patterns of vegetation and inter-patches following single and repeated wildfires

    Science.gov (United States)

    González, Óscar; Malvar, Maruxa; van den Elsen, Erik; Hosseini, mohammadreza; Coelho, Celeste; Ritsema, Coen; Bautista, Susana; Keizer, Jan Jacob; Cerdà, Artemi

    2015-04-01

    Although wildfires spread in Mediterranean areas are considered a natural processes, the expected increase in fire frequency has raised concerns about the systems' future resilience (Pausas, 2004). Besides more frequent, future wildfires can become more severe and produce more pronounced changes in topsoil properties, vegetation and litter (Cerdá and Mataix-Solera, 2009). To deal with challenges, the EU funded CASCADE and RECARE projects, which are currently assessing soil threats and tipping-points for land degradation in a climatic gradient across Europe. The present research was developed in Portugal and aims to find relationships between fire frequency and soil wetting patterns following single versus repeated wildfires. In September 2012, a wildfire burnt 3000 ha. of Pine stands and shrub vegetation in the vicinity of Viseu district, North-Central Portugal. Analyses according to the available burnt-area maps (1975-2012), discriminated areas that has been burned 1x (called SD) and 4x (called D) times. In order to evaluate the post-fire soil surface moisture patterns, 6 slopes (3 in SD and 3 in D) were selected and a balanced experimental design with 72 soil moisture sensors (EC5 and GS3, from Decagon devices) was implemented under shrubs (n=18) and on bare (n=18) soil environments, at 2.5 cm and 7.5 cm soil depth each. The spatio-temporal occurrence of soil water repellence (SWR) (Keizer et al., 2008; Prats et al., 2013; Santos et al., 2014) was monthly assessed through the MED test at 2.5 cm and 7.5 cm soil depth into 5 sampling points located at regular distances along a transect running from the top to bottom of a selected slope in SD and D. Automatic and totalize rainfall gauges were also installed across the study area. Preliminary results showed that soil wetting patterns and SWR occurrence differs between SD, D sites and, between soil environment (under shrubs and on bare soil areas). SWR were more pronounced on the SD than in D, affecting soil wetting

  11. Repeatability of gait pattern variables measured by use of extremity-mounted inertial measurement units in nonlame horses during trotting.

    Science.gov (United States)

    Cruz, Antonio M; Maninchedda, Ugo E; Burger, Dominik; Wanda, Sabine; Vidondo, Beatriz

    2017-09-01

    OBJECTIVE To determine repeatability of gait variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses during trotting under controlled conditions of treadmill exercise. ANIMALS 10 horses. PROCEDURES Six IMUs were strapped to the metacarpal, metatarsal, and distal tibial regions of each horse. Data were collected in a standardized manner (3 measurements/d on 3 d/wk over a 3-week period) while each horse was trotted on a treadmill. Every measurement consisted of a minimum of 20 strides from which a minimum of 10 strides was selected for analysis. Spatial and temporal variables were derived from the IMUs. Repeatability coefficients based on the within-subject SD were computed for each gait analysis variable at each week. RESULTS Most of the temporal and spatial variables had high repeatability (repeatability coefficients variables, specifically the symmetry variables (which were calculated from other variables), had somewhat higher repeatability coefficients (ie, lower repeatability) only in the last week. CONCLUSIONS AND CLINICAL RELEVANCE With the exceptions of some symmetry variables, which may reflect individual variations during movement, the extremity-mounted IMUs provided data with high repeatability for nonlame horses trotting under controlled conditions of treadmill exercise. Repeatability was achieved for each instrumented limb segment with regard to the spatial relationship between 2 adjacent segments (joint angles) and the temporal relationship among all segments (limb phasing). Extremity-mounted IMUs could have the potential to become a method for gait analysis in horses.

  12. Patient characteristics and patterns of intoxication: one-time and repeated use of emergency ambulance services.

    Science.gov (United States)

    Holzer, Barbara M; Minder, Christoph E; Rosset, Nina; Schaetti, Gabriela; Battegay, Edouard; Mueller, Stefan; Zimmerli, Lukas

    2013-05-01

    The aim of this study was to investigate the utilization of ambulance services that resulted from alcohol and drug intoxication over a period of 1 year in a metropolitan area, with an emphasis on characteristic differences between patients with one-time versus repeated use. All ambulance-service report forms filed in 2010 were systematically screened for utilizations in which alcohol intoxication or intoxication resulting from consumption of illicit or legal drugs other than alcohol was the chief complaint (N = 2,341 patients; 65% male). Repeat users differed from persons with one-time use in their characteristics and patterns of intoxication. On average, patients with repeated ambulance use were almost 8 years older and had a different pattern of ambulance use over the course of the week with no clear peak on any specific day. The mean number of ambulance services in patients with repeated use was 2.8 (SD = 1.517) in the 1-year study period. Repeat users were less likely to be injured than patients with one-time ambulance-service use and more often showed aggression or uncooperative behavior toward paramedics. All cases of death associated with intoxication involved patients with one-time ambulance use. The ambulance-service users' generally slight impairment of consciousness and the high proportion of intoxicated patients without any injuries raise the question of how many of these patients could be adequately cared for in a sobering center. Sobering centers might relieve hospital emergency departments of patients not requiring acute emergency care and, in addition, could provide intervention services to prevent relapses.

  13. Spatio-temporal patterns of Campylobacter colonization in Danish broilers

    DEFF Research Database (Denmark)

    Chowdhury, S; Themudo, G E; Sandberg, M

    2013-01-01

    SUMMARY Despite a number of risk-factor studies in different countries, the epidemiology of Campylobacter colonization in broilers, particularly spatial dependencies, is still not well understood. A series of analyses (visualization and exploratory) were therefore conducted in order to obtain...... a better understanding of the spatial and temporal distribution of Campylobacter in the Danish broiler population. In this study, we observed a non-random temporal occurrence of Campylobacter, with high prevalence during summer and low during winter. Significant spatio-temporal clusters were identified...

  14. Temporal motifs reveal homophily, gender-specific patterns and group talk in mobile communication networks

    CERN Document Server

    Kovanen, Lauri; Kertész, János; Saramäki, Jari

    2013-01-01

    Electronic communication records provide detailed information about temporal aspects of human interaction. Previous studies have shown that individuals' communication patterns have complex temporal structure, and that this structure has system-wide effects. In this paper we use mobile phone records to show that interaction patterns involving multiple individuals have non-trivial temporal structure that cannot be deduced from a network presentation where only interaction frequencies are taken into account. We apply a recently introduced method, temporal motifs, to identify interaction patterns in a temporal network where nodes have additional attributes such as gender and age. We then develop a null model that allows identifying differences between various types of nodes so that these differences are independent of the network based on interaction frequencies. We find gender-related differences in communication patters, and show the existence of temporal homophily, the tendency of similar individuals to partic...

  15. Determining Scale-dependent Patterns in Spatial and Temporal Datasets

    Science.gov (United States)

    Roy, A.; Perfect, E.; Mukerji, T.; Sylvester, L.

    2016-12-01

    Spatial and temporal datasets of interest to Earth scientists often contain plots of one variable against another, e.g., rainfall magnitude vs. time or fracture aperture vs. spacing. Such data, comprised of distributions of events along a transect / timeline along with their magnitudes, can display persistent or antipersistent trends, as well as random behavior, that may contain signatures of underlying physical processes. Lacunarity is a technique that was originally developed for multiscale analysis of data. In a recent study we showed that lacunarity can be used for revealing changes in scale-dependent patterns in fracture spacing data. Here we present a further improvement in our technique, with lacunarity applied to various non-binary datasets comprised of event spacings and magnitudes. We test our technique on a set of four synthetic datasets, three of which are based on an autoregressive model and have magnitudes at every point along the "timeline" thus representing antipersistent, persistent, and random trends. The fourth dataset is made up of five clusters of events, each containing a set of random magnitudes. The concept of lacunarity ratio, LR, is introduced; this is the lacunarity of a given dataset normalized to the lacunarity of its random counterpart. It is demonstrated that LR can successfully delineate scale-dependent changes in terms of antipersistence and persistence in the synthetic datasets. This technique is then applied to three different types of data: a hundred-year rainfall record from Knoxville, TN, USA, a set of varved sediments from Marca Shale, and a set of fracture aperture and spacing data from NE Mexico. While the rainfall data and varved sediments both appear to be persistent at small scales, at larger scales they both become random. On the other hand, the fracture data shows antipersistence at small scale (within cluster) and random behavior at large scales. Such differences in behavior with respect to scale-dependent changes in

  16. Temporal introduction patterns of invasive alien plant species to Australia

    Directory of Open Access Journals (Sweden)

    Brad Murray

    2012-05-01

    Full Text Available We examined temporal introduction patterns of 132 invasive alien plant species (IAPS to Australia since European colonisation in 1770. Introductions of IAPS were high during 1810–1820 (10 species, 1840–1880 (51 species, 38 of these between 1840 and 1860 and 1930–1940 (9 species. Conspicuously few introductions occurred during 10-year periods directly preceding each introduction peak. Peaks during early European settlement (1810–1820 and human range expansion across the continent (1840-1860 both coincided with considerable growth in Australia’s human population. We suggest that population growth during these times increased the likelihood of introduced plant species becoming invasive as a result of increased colonization and propagule pressure. Deliberate introductions of IAPS (104 species far outnumbered accidental introductions (28 species and were particularly prominent during early settlement. Cosmopolitan IAPS (25 species and those native solely to South America (53 species, Africa (27 species and Asia (19 species have been introduced deliberately and accidentally to Australia across a broad period of time. A small number of IAPS, native solely to Europe (5 species and North America (2 species, were all introduced to Australia prior to 1880. These contrasting findings for native range suggest some role for habitat matching, with similar environmental conditions in Australia potentially driving the proliferation of IAPS native to southern-hemisphere regions. Shrub, tree and vine species dominated IAPS introduced prior to 1840, with no grasses or forbs introduced during early colonisation. Since 1840, all five growth forms have been introduced deliberately and accidentally in relatively large numbers across a broad period of time. In particular, a large number of grass and forb IAPS were deliberately introduced between 1840 and 1860, most likely a direct result of the introduction of legislation promoting intensive agriculture across

  17. optix drives the repeated convergent evolution of butterfly wing pattern mimicry.

    Science.gov (United States)

    Reed, Robert D; Papa, Riccardo; Martin, Arnaud; Hines, Heather M; Counterman, Brian A; Pardo-Diaz, Carolina; Jiggins, Chris D; Chamberlain, Nicola L; Kronforst, Marcus R; Chen, Rui; Halder, Georg; Nijhout, H Frederik; McMillan, W Owen

    2011-08-26

    Mimicry--whereby warning signals in different species evolve to look similar--has long served as a paradigm of convergent evolution. Little is known, however, about the genes that underlie the evolution of mimetic phenotypes or to what extent the same or different genes drive such convergence. Here, we characterize one of the major genes responsible for mimetic wing pattern evolution in Heliconius butterflies. Mapping, gene expression, and population genetic work all identify a single gene, optix, that controls extreme red wing pattern variation across multiple species of Heliconius. Our results show that the cis-regulatory evolution of a single transcription factor can repeatedly drive the convergent evolution of complex color patterns in distantly related species, thus blurring the distinction between convergence and homology.

  18. Detecting small-scale spatial heterogeneity and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

    Science.gov (United States)

    Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

    2017-03-01

    Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial (10-30 m) and temporal changes in SOC stocks, particularly pronounced in arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal dynamics as well as small-scale spatial differences of ΔSOC using measurements of the net ecosystem carbon balance (NECB) as a proxy. To estimate the NECB, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) were used. To verify our method, results were compared with ΔSOC observed by soil resampling. Soil resampling and AC measurements were performed from 2010 to 2014 at a colluvial depression located in the hummocky ground moraine landscape of northeastern Germany. The measurement site is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity regarding SOC and nitrogen (Nt) stocks. Tendencies and magnitude of ΔSOC values derived by AC measurements and repeated soil inventories corresponded well. The period of maximum plant growth was identified as being most important for the development of spatial differences in annual ΔSOC. Hence, we were able to confirm that AC-based C budgets are able

  19. Detecting small-scale spatial differences and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

    Science.gov (United States)

    Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

    2017-04-01

    Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial and temporal changes in SOC stocks, particularly pronounced on arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal as well as small-scale spatial dynamics of ΔSOC. Therefore, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) was used. To verify our method, results were compared with ΔSOC observed by soil resampling. AC measurements were performed from 2010 to 2014 under a silage maize/winter fodder rye/sorghum-Sudan grass hybrid/alfalfa crop rotation at a colluvial depression located in the hummocky ground moraine landscape of NE Germany. Widespread in large areas of the formerly glaciated Northern Hemisphere, this depression type is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity in soil properties, such as SOC and nitrogen (Nt). After monitoring the initial stage during 2010, soil erosion was experimentally simulated by incorporating topsoil material from an eroded midslope soil into the plough layer of the colluvial depression. SOC stocks were quantified before and after soil manipulation and at the end

  20. Changes in pathological pattern and treatment regimens based on repeat renal biopsy in lupus nephritis

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-bao; XU Zheng-jin; LIU Hong-fa; ZHOU Qiu-gen; ZHOU Zhan-mei; JIA Nan

    2012-01-01

    Background Relapses occur frequently in patients with lupus nephritis.Renal biopsy is the gold standard for assessing renal activity and hence guiding the treatment.Whether repeat renal biopsy is helpful during flares of lupus nephritis remains inconclusive.In the present study,we retrospectively reviewed the patients with lupus nephritis who had more than one renal biopsy with the hope to find the clinical value of repeat biopsy.Methods Patients who had a diagnosis of lupus nephritis and two or more renal biopsies were selected from the database of the patient pathology registration at this renal division.Renal biopsy was evaluated according to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification of lupus nephritis.The pathological patterns and treatment regimens were analyzed after a repeat biopsy.Results We identified 44 systemic lupus erythematosus patients with serial renal biopsies.In total,there were 94 renal biopsies.Overall,the pathological transition occurred in 64% instances according to the ISN/RPS class.When the transition was analyzed according to proliferative,membranous or mix lesions,it showed different profile:35% in patients with proliferative lesion,23.5% patients with mix lesions,100% in patients with pure membranous lesion.The pathological transition could not be predicted by any clinical characteristics.After the repeat renal biopsy,34% of patients had a change in their treatment regimens.Conclusions The pathological conversion was very prevalent in patients with lupus nephritis.However,the transitions became less prevalent when they were analyzed according to pure membranous,proliferative,and mix lesion.Repeat biopsy might be helpful to avoid unnecessary increased immunosuppression therapy.

  1. Impacts of Temporal-Spatial Variant Background Ionosphere on Repeat-Track GEO D-InSAR System

    Directory of Open Access Journals (Sweden)

    Cheng Hu

    2016-11-01

    Full Text Available An L band geosynchronous synthetic aperture radar (GEO SAR differential interferometry system (D-InSAR will be obviously impacted by the background ionosphere, which will give rise to relative image shifts and decorrelations of the SAR interferometry (InSAR pair, and induce the interferometric phase screen errors in interferograms. However, the background ionosphere varies within the long integration time (hundreds to thousands of seconds and the extensive imaging scene (1000 km levels of GEO SAR. As a result, the conventional temporal-spatial invariant background ionosphere model (i.e., frozen model used in Low Earth Orbit (LEO SAR is no longer valid. To address the issue, we firstly construct a temporal-spatial background ionosphere variation model, and then theoretically analyze its impacts, including relative image shifts and the decorrelation of the GEO InSAR pair, and the interferometric phase screen errors, on the repeat-track GEO D-InSAR processing. The related impacts highly depend on the background ionosphere parameters (constant total electron content (TEC component, and the temporal first-order and the temporal second-order derivatives of TEC with respect to the azimuth time, signal bandwidth, and integration time. Finally, the background ionosphere data at Isla Guadalupe Island (29.02°N, 118.27°W on 7–8 October 2013 is employed for validating the aforementioned analysis. Under the selected background ionosphere dataset, the temporal-spatial background ionosphere variation can give rise to a relative azimuth shift of dozens of meters at most, and even the complete decorrelation in the InSAR pair. Moreover, the produced interferometric phase screen error corresponds to a deformation measurement error of more than 0.2 m at most, even in a not severely impacted area.

  2. Modeling spatio-temporal wildfire ignition point patterns

    Science.gov (United States)

    Amanda S. Hering; Cynthia L. Bell; Marc G. Genton

    2009-01-01

    We analyze and model the structure of spatio-temporal wildfire ignitions in the St. Johns River Water Management District in northeastern Florida. Previous studies, based on the K-function and an assumption of homogeneity, have shown that wildfire events occur in clusters. We revisit this analysis based on an inhomogeneous K-...

  3. Life between Clocks : Daily Temporal Patterns of Human Chronotypes

    NARCIS (Netherlands)

    Roenneberg, Till; Wirz-Justice, Anna; Merrow, Martha

    2003-01-01

    Human behavior shows large interindividual variation in temporal organization. Extreme “larks” wake up when extreme “owls” fall asleep. These chronotypes are attributed to differences in the circadian clock, and in animals, the genetic basis of similar phenotypic differences is well established. To

  4. Grid patterns, spatial inter-scan variations and scanning reading repeatability in radiochromic film dosimetry

    CERN Document Server

    Méndez, I; Hudej, R; Jenko, A; Casar, B

    2016-01-01

    Purpose: When comparing different scans of the same radiochromic film, several patterns can be observed. These patterns are caused by different sources of uncertainty, which affect the repeatability of the scanner. The purpose of this work was to study these uncertainties. Methods: The variance of the scanner noise, as a function of the pixel position, was studied for different resolutions. The inter-scan variability of the scanner response was analyzed taking into account spatial discrepancies. Finally, the distance between the position of the same point in different scans was examined. Results: The variance of noise follows periodical patterns in both axes, causing the grid patterns. These patterns were identified for resolutions of 50, 72 and 96 dpi, but not for 150 dpi. Specially recognizable is the sinusoidal shape with a period of 8.5 mm that is produced with 72 dpi. Inter-scan variations of the response caused systematic relative dose deviations larger than 1% in 5% of the red channel images, 9% of the...

  5. Suppression of Repeat-Intensive False Targets Based on Temporal Pulse Diversity

    Directory of Open Access Journals (Sweden)

    Gang Lu

    2013-01-01

    Full Text Available This paper considers the problem of suppressing the repeat-intensive false targets produced by a deception electronic attack (EA system equipped with a Digital Radio Frequency Memory (DRFM device. Different from a conventional repeat jammer, this type of jamming intensively retransmits the intercepted signal stored in a DRFM to the victim radar in a very short time-delay interval relative to a radar pulse wide. A multipeak matched-filtering output is then produced other than the merely expected true target. An electronic protection (EP algorithm based on the space time block code (STBC is proposed to suppress the adverse effects of this jammer. By transmitting a pulse sequence generated from the STBC in succession and the following cancellation process applied upon the received signal, this algorithm performs successfully in a single antenna system provided that the target models are nonfluctuating or slow fluctuating and the pulse repetition frequency (PRF is comparatively high. The performance in white and correlated Gaussian disturbance is evaluated by means of Monte Carlo simulations.

  6. Brief Report: The Temporal Stability of the Repeatable Battery for the Assessment of Neuropsychological Status Effort Index in Geriatric Samples

    Science.gov (United States)

    O'Mahar, Kerry M.; Duff, Kevin; Scott, James G.; Linck, John F.; Adams, Russell L.; Mold, James W.

    2012-01-01

    The Effort Index (EI) of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was developed to identify inadequate effort. Although researchers have examined its validity, the reliability of the EI has not been evaluated. The current study examined the temporal stability of the EI across 1 year in two independent samples of older adults. One sample consisted of 445 cognitively intact older adults (mean age = 72.89; 59% having 12–15 years of education) and the second sample consisted of 51 individuals diagnosed with amnestic Mild Cognitive Impairment (mean age = 82.41; 41% having 12–15 years of education). For both samples, the EI was found to have low stability (Spearman's ρ = .32–.36). When participants were divided into those whose EI stayed stable or improved versus those whose EI worsened (i.e., declining effort) on retesting, it was observed that individuals with lower baseline RBANS Total scores tended to worsen on the EI across time. Overall, the findings suggest low temporal stability of the EI in two geriatric samples. In particular, individuals with poorer cognition at baseline could present with poorer effort across time. These findings also suggest the need to further examine the temporal stability of other effort measures. PMID:22075575

  7. A model for optimizing file access patterns using spatio-temporal parallelism

    Energy Technology Data Exchange (ETDEWEB)

    Boonthanome, Nouanesengsy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patchett, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Geveci, Berk [Kitware Inc., Clifton Park, NY (United States); Ahrens, James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bauer, Andy [Kitware Inc., Clifton Park, NY (United States); Chaudhary, Aashish [Kitware Inc., Clifton Park, NY (United States); Miller, Ross G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shipman, Galen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-01-01

    For many years now, I/O read time has been recognized as the primary bottleneck for parallel visualization and analysis of large-scale data. In this paper, we introduce a model that can estimate the read time for a file stored in a parallel filesystem when given the file access pattern. Read times ultimately depend on how the file is stored and the access pattern used to read the file. The file access pattern will be dictated by the type of parallel decomposition used. We employ spatio-temporal parallelism, which combines both spatial and temporal parallelism, to provide greater flexibility to possible file access patterns. Using our model, we were able to configure the spatio-temporal parallelism to design optimized read access patterns that resulted in a speedup factor of approximately 400 over traditional file access patterns.

  8. (TG/CAn repeats in human gene families: abundance and selective patterns of distribution according to function and gene length

    Directory of Open Access Journals (Sweden)

    Ramachandran Srinivasan

    2005-06-01

    Full Text Available Abstract Background Creation of human gene families was facilitated significantly by gene duplication and diversification. The (TG/CAn repeats exhibit length variability, display genome-wide distribution, and are abundant in the human genome. Accumulation of evidences for their multiple functional roles including regulation of transcription and stimulation of recombination and splicing elect them as functional elements. Here, we report analysis of the distribution of (TG/CAn repeats in human gene families. Results The 1,317 human gene families were classified into six functional classes. Distribution of (TG/CAn repeats were analyzed both from a global perspective and from a stratified perspective based on their biological properties. The number of genes with repeats decreased with increasing repeat length and several genes (53% had repeats of multiple types in various combinations. Repeats were positively associated with the class of Signaling and communication whereas, they were negatively associated with the classes of Immune and related functions and of Information. The proportion of genes with (TG/CAn repeats in each class was proportional to the corresponding average gene length. The repeat distribution pattern in large gene families generally mirrored the global distribution pattern but differed particularly for Collagen gene family, which was rich in repeats. The position and flanking sequences of the repeats of Collagen genes showed high conservation in the Chimpanzee genome. However the majority of these repeats displayed length polymorphism. Conclusion Positive association of repeats with genes of Signaling and communication points to their role in modulation of transcription. Negative association of repeats in genes of Information relates to the smaller gene length, higher expression and fundamental role in cellular physiology. In genes of Immune and related functions negative association of repeats perhaps relates to the smaller gene

  9. Temporal lobe epilepsy subtypes, differential patterns of cerebral perfusion on ictal SPECT

    NARCIS (Netherlands)

    Ho, SS; Berkovic, SF; McKay, WJ; Kalnins, RM; Bladin, PF

    1996-01-01

    Purpose: We studied cerebral perfusion patterns in the various subtypes of TLE, as determined by pathology and good outcome after temporal lobectomy (as confirmation of temporal origin). Methods: We studied clinical features and ictal technetium 99m hexamethyl-propyleneamineoxime (Tc-99m-HMPAO) sing

  10. General asymmetric neutral networks and structure design by genetic algorithms: A learning rule for temporal patterns

    Energy Technology Data Exchange (ETDEWEB)

    Bornholdt, S. [Heidelberg Univ., (Germany). Inst., fuer Theoretische Physik; Graudenz, D. [Lawrence Berkeley Lab., CA (United States)

    1993-07-01

    A learning algorithm based on genetic algorithms for asymmetric neural networks with an arbitrary structure is presented. It is suited for the learning of temporal patterns and leads to stable neural networks with feedback.

  11. Spatio-temporal variability of abient seismic noise repeatedly monitored above a geothermal reservoir

    Science.gov (United States)

    Woith, H.; Parolai, S.; Picozzi, M.; Boxberger, T.; Milkereit, C.; Zschau, J.

    2011-12-01

    A simple method had been proposed to use passive seismic noise measurements as "direct hydrocarbon indicators (DHI)". It had been claimed that low frequency (1-10 Hz) seismic signal anomalies correlate with the occurrence of hydrocarbons. Due to lack of convincing case studies and an underlying theory the approach is severely under discussion. Three mechanisms had been proposed to explain the anomalous seismic signals: (1) macroscopic resonance effects of standing waves, (2) selective attenuation of seismic waves, and (3) resonant scattering/amplification at microscopic scales. In the frame of a theoretical work (co-funded by a consulting company and GFZ) the selective attenuation of seismic waves as a DHI mechanism could be ruled out. Assuming that the seismic noise is originated within the reservoir (source effect), it should be possible to locate the noise source with array techniques by deploying arrays around the reservoir. For this reason, a series of tests have been carried out above oil, gas and geothermal reservoirs - none of them indicating a noise source inside the reservoir. In one case, a nearby wind park could be identified as a noise source. Here, we focus on repeated measurements of seismic noise related to the Heybeli geothermal reservoir in Turkey. We compared repeated noise measurements from 2002, 2010, and 2011. In 2002 profile measurements were performed during the aftershock sequence of the Mw=6.5 Sultandagi earthquake of 03.02.2002, where a distinct cluster of aftershocks was co-located with the geothermal field of Heybeli. In October 2010 six arrays (each consisting of 17 geophones; seismic noise recorded for several hours; thereafter the array was moved to the next position) had been located on and off the reservoir. Again, a clear noise source coming from the reservoir could not be clearly identified. Nevertheless, at some sites in the centre of the reservoir a 6-Hz-signal was observed. The origin of this signal is not clear yet. Hence, it

  12. Characteristics of Spatial Structural Patterns and Temporal Variability of Annual Precipitation in Ningxia

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the characteristics of the spatial structural patterns and temporal variability of annual precipitation in Ningxia.[Method] Using rotated empirical orthogonal function,the precipitation concentration index,wavelet analysis and Mann-Kendall rank statistic method,the characteristics of precipitation on the spatial-temporal variability and trend were analyzed by the monthly precipitation series in Ningxia during 1951-2008.[Result] In Ningxia,the spatial structural patterns of a...

  13. Prediction of spatio-temporal patterns of neural activity from pairwise correlations

    OpenAIRE

    Marre, Olivier; Boustani, Sami El; Fregnac, Yves; Destexhe, Alain

    2009-01-01

    We designed a model-based analysis to predict the occurrence of population patterns in distributed spiking activity. Using a maximum entropy principle with a Markovian assumption, we obtain a model that accounts for both spatial and temporal pairwise correlations among neurons. This model is tested on data generated with a Glauber spin-glass system and is shown to correctly predict the occurrence probabilities of spatio-temporal patterns significantly better than Ising models taking into acco...

  14. A novel triple repeat mutant tau transgenic model that mimics aspects of pick's disease and fronto-temporal tauopathies.

    Directory of Open Access Journals (Sweden)

    Edward Rockenstein

    Full Text Available Tauopathies are a group of disorders leading to cognitive and behavioral impairment in the aging population. While four-repeat (4R Tau is more abundant in corticobasal degeneration, progressive supranuclear palsy, and Alzheimer's disease, three-repeat (3R Tau is the most abundant splice, in Pick's disease. A number of transgenic models expressing wild-type and mutant forms of the 4R Tau have been developed. However, few models of three-repeat Tau are available. A transgenic mouse model expressing three-repeat Tau was developed bearing the mutations associated with familial forms of Pick's disease (L266V and G272V mutations. Two lines expressing high (Line 13 and low (Line 2 levels of the three-repeat mutant Tau were analyzed. By Western blot, using antibodies specific to three-repeat Tau, Line 13 expressed 5-times more Tau than Line 2. The Tau expressed by these mice was most abundant in the frontal-temporal cortex and limbic system and was phosphorylated at residues detected by the PHF-1, AT8, CP9 and CP13 antibodies. The higher-expressing mice displayed hyperactivity, memory deficits in the water maze and alterations in the round beam. The behavioral deficits started at 6-8 months of age and were associated with a progressive increase in the accumulation of 3R Tau. By immunocytochemistry, mice from Line 13 displayed extensive accumulation of 3R Tau in neuronal cells bodies in the pyramidal neurons of the neocortex, CA1-3 regions, and dentate gyrus of the hippocampus. Aggregates in the granular cells had a globus appearance and mimic Pick's-like inclusions. There were abundant dystrophic neurites, astrogliosis and synapto-dendritic damage in the neocortex and hippocampus of the higher expresser line. The hippocampal lesions were moderately argyrophilic and Thioflavin-S negative. By electron microscopy, discrete straight filament aggregates were detected in some neurons in the hippocampus. This model holds promise for better understanding the

  15. Methane Seeps in the Gulf of Mexico: repeat acoustic surveying shows highly temporally and spatially variable venting

    Science.gov (United States)

    Beaumont, B. C.; Raineault, N.

    2016-02-01

    Scientists have recognized that natural seeps account for a large amount of methane emissions. Despite their widespread occurrence in areas like the Gulf of Mexico, little is known about the temporal variability and site-scale spatial variability of venting over time. We used repeat acoustic surveys to compare multiple days of seep activity and determine the changes in the locus of methane emission and plume height. The Sleeping Dragon site was surveyed with an EM302 multibeam sonar on three consecutive days in 2014 and 4 days within one week in 2015. The data revealed three distinctive plume regions. The locus of venting varied by 10-60 meters at each site. The plume that exhibited the least spatial variability in venting, was also the most temporally variable. This seep was present in one-third of survey dates in 2014 and three quarters of survey dates in 2015, showing high day-to-day variability. The plume height was very consistent for this plume, whereas the other plumes were more consistent temporally, but varied in maximum plume height detection by 25-85 m. The single locus of emission at the site that had high day-to-day variability may be due to a single conduit for methane release, which is sometimes closed off by carbonate or clathrate hydrate formation. In addition to day-to-day temporal variability, the locus of emission at one site was observed to shift from a point-source in 2014 to a diffuse source in 2015 at a nearby location. ROV observations showed that one of the seep sites that closed off temporarily, experienced an explosive breakthrough of gas, releasing confined methane and blowing out rock. The mechanism that causes on/off behavior of certain plumes, combined with the spatial variability of the locus of methane release shown in this study may point to carbonate or hydrate formation in the seep plumbing system and should be further investigated.

  16. Mosses as biomonitors of atmospheric heavy metal deposition: Spatial patterns and temporal trends in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Harmens, H., E-mail: hh@ceh.ac.u [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW (United Kingdom); Norris, D.A., E-mail: danor@ceh.ac.u [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW (United Kingdom); Steinnes, E., E-mail: Eiliv.Steinnes@chem.ntnu.n [Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Kubin, E., E-mail: Eero.Kubin@metla.f [Finnish Forest Research Institute, Kirkkosaarentie 7, 91500 Muhos (Finland); Piispanen, J., E-mail: Juha.Piispanen@metla.f [Finnish Forest Research Institute, Kirkkosaarentie 7, 91500 Muhos (Finland); Alber, R., E-mail: Renate.Alber@provinz.bz.i [Environmental Agency of Bolzano, 39055 Laives (Italy); Aleksiayenak, Y., E-mail: beataa@gmail.co [International Sakharov Environmental University, Minsk (Belarus); Blum, O., E-mail: blum@nbg.kiev.u [National Botanical Garden, Academy of Science of Ukraine, Timiryazevs' ka St. 1, 01014 Kyiv (Ukraine); Coskun, M., E-mail: coskunafm@yahoo.co [Canakkale Onsekiz Mart University, 17100 Canakkale (Turkey); Dam, M., E-mail: mariad@us.f [Environment Agency, Traoagota 38, FO-165 Argir (Faroe Islands); De Temmerman, L., E-mail: ludet@var.fgov.b [Veterinary and Agrochemical Research Centre, Leuvensesteenweg 17, 3080 Tervuren (Belgium); Fernandez, J.A., E-mail: jangel.fernandez@usc.e [University of Santiago de Compestela, Faculty of Biology, Department of Ecology, 15782 Santiago de Compostela (Spain); Frolova, M., E-mail: marina.frolova@lvgma.gov.l [Latvian Environment, Geology and Meteorology Agency, Maskavas Str. 165, Riga LV 1019 (Latvia); Frontasyeva, M., E-mail: marina@nf.jinr.r [Joint Institute for Nuclear Research, Str. Joliot-Curie 6, 141980 Dubna (Russian Federation); Gonzalez-Miqueo, L., E-mail: lgonzale2@alumni.unav.e [University of Navarra, Irunlarrea No 1, 31008 Pamplona (Spain)

    2010-10-15

    In recent decades, mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals. Since 1990, the European moss survey has been repeated at five-yearly intervals. Although spatial patterns were metal-specific, in 2005 the lowest concentrations of metals in mosses were generally found in Scandinavia, the Baltic States and northern parts of the UK; the highest concentrations were generally found in Belgium and south-eastern Europe. The recent decline in emission and subsequent deposition of heavy metals across Europe has resulted in a decrease in the heavy metal concentration in mosses for the majority of metals. Since 1990, the concentration in mosses has declined the most for arsenic, cadmium, iron, lead and vanadium (52-72%), followed by copper, nickel and zinc (20-30%), with no significant reduction being observed for mercury (12% since 1995) and chromium (2%). However, temporal trends were country-specific with sometimes increases being found. - Since 1990, heavy metal concentrations in mosses have declined in Europe for most metals.

  17. Long-period seismic events with strikingly regular temporal patterns on Katla volcano's south flank (Iceland)

    CERN Document Server

    Sgattoni, Giulia; Guðmundsson, Ólafur; Einarsson, Páll; Tryggvason, Ari; Lund, Björn; Lucchi, Federico

    2015-01-01

    Katla is a threatening volcano in Iceland, partly covered by the M\\'yrdalsj\\"okull ice cap. The volcano has a large caldera with several active geothermal areas. A peculiar cluster of long-period seismic events started on Katla's south flank in July 2011, during an unrest episode in the caldera that culminated in a glacier outburst. The seismic events were tightly clustered at shallow depth in the Gvendarfell area, 4 km south of the caldera, under a small glacier stream on the southern margin of M\\'yrdalsj\\"okull. No seismic events were known to have occurred in this area before. The most striking feature of this seismic cluster is its temporal pattern, characterized by regular intervals between repeating seismic events, modulated by a seasonal variation. Remarkable is also the stability of both the time and waveform features over a long time period, around 3.5 years. No comparable examples have been found in the literature. Both volcanic and glacial processes can produce similar waveforms and therefore have ...

  18. Observation of spatio-temporal pattern in magnetised rf plasmas

    CERN Document Server

    Bandyopadhyay, P; Konopka, U; Morfill, G

    2016-01-01

    We address an experimental observation of pattern formation in a magnetised rf plasma. The experiments are carried out in a electrically grounded aluminium chamber which is housed inside a rotatable superconducting magnetic coil. The plasma is formed by applying a rf voltage in parallel plate electrodes in push-pull mode under the background of argon gas. The time evolution of plasma intensity shows that a homogeneous plasma breaks into several concentric radial spatiotemoral bright and dark rings. These rings propagate radially at considerably low pressure and a constant magnetic field. These patterns are observed to trap small dust particles/grains in their potential. Exploiting this property of the patterns, a novel technique to measure the electric field associated with the patterns is described. The resulting estimates of the corresponding field intensity are presented. At other specific discharge parameters the plasma shows a range of special type of characteristic structures observed in certain other c...

  19. Exploring Spatial-Temporal Patterns of Urban Human Mobility Hotspots

    National Research Council Canada - National Science Library

    Yang, Xiping; Zhao, Zhiyuan; Lu, Shiwei

    2016-01-01

    Understanding human mobility patterns provides us with knowledge about human mobility in an urban context, which plays a critical role in urban planning, traffic management and the spread of disease...

  20. Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements

    Science.gov (United States)

    Gillespie, Jonathan; Masey, Nicola; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

    2017-02-01

    Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires substantial time and monitoring equipment. The objective of this study was to establish if short-duration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO2) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40-80%, and 7-64% respectively, of spatial variation in the intervening 1-week NO2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1-week NO2 concentrations over the same period. The relatively high explained variation observed between BC and NO2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.

  1. [Temporality and trauma: Towards an articulation between the judicial, educational and psychological times in repeat teenage offenders].

    Science.gov (United States)

    Kermarrec, S; Mougli, K

    2015-09-01

    Within the past few years, the problem of repeat teenage offenders has raised troubling questions among the various institutions in charge of this population. The temporalities of these adolescents are marked by immediacy, urgency, and repetition that circumvent a linear view of time and the programs set up to handle them. Studies on repeat teenage aggressors (notably, sexual aggressors) have shown that these young people often have a history of an acknowledged or unacknowledged trauma. The fact of having been a victim of abuse during childhood is thought to be a factor leading to later acting out. Our objective is to inquire into these juvenile delinquents and their treatment using a temporal framework of their life pathway that will influence the ways in which they are treated by professionals. By tracing back through the lives of these young authors of violence, we can find out whether they were themselves victims. Repeated acts of violence by a youth could then be seen not as isolated acts but as expressions of ill-being, of having been a victim, whether recognized or not. The act thus represents a link between the present and the past that can be analyzed by looking at occurrences of acting out. It would be interesting, moreover, to reflect upon how continuity could be created there where disruption strikes the youth and often the institutions too. We provide a detailed description of the notion of trauma by recalling its definition and its possible immediate and deferred effects on these youths. In the immediate time frame, the subject may present a physical reaction to the trauma. The psychological reaction will determine a psychic time frame expressed in several ways, whether immediately or at a distance from the traumatic event. Posttraumatic reactions may hamper the development of the teenager's personality. Some traumatized adolescents will express their ill-being by aggressiveness, as they replay the traumatic scene by staging violent and dangerous

  2. Analysis of spatial-temporal gene expression patterns reveals dynamics and regionalization in developing mouse brain.

    Science.gov (United States)

    Chou, Shen-Ju; Wang, Chindi; Sintupisut, Nardnisa; Niou, Zhen-Xian; Lin, Chih-Hsu; Li, Ker-Chau; Yeang, Chen-Hsiang

    2016-01-20

    Allen Brain Atlas (ABA) provides a valuable resource of spatial/temporal gene expressions in mammalian brains. Despite rich information extracted from this database, current analyses suffer from several limitations. First, most studies are either gene-centric or region-centric, thus are inadequate to capture the superposition of multiple spatial-temporal patterns. Second, standard tools of expression analysis such as matrix factorization can capture those patterns but do not explicitly incorporate spatial dependency. To overcome those limitations, we proposed a computational method to detect recurrent patterns in the spatial-temporal gene expression data of developing mouse brains. We demonstrated that regional distinction in brain development could be revealed by localized gene expression patterns. The patterns expressed in the forebrain, medullary and pontomedullary, and basal ganglia are enriched with genes involved in forebrain development, locomotory behavior, and dopamine metabolism respectively. In addition, the timing of global gene expression patterns reflects the general trends of molecular events in mouse brain development. Furthermore, we validated functional implications of the inferred patterns by showing genes sharing similar spatial-temporal expression patterns with Lhx2 exhibited differential expression in the embryonic forebrains of Lhx2 mutant mice. These analysis outcomes confirm the utility of recurrent expression patterns in studying brain development.

  3. The encoding of temporally irregular and regular visual patterns in the human brain.

    Directory of Open Access Journals (Sweden)

    Semir Zeki

    Full Text Available In the work reported here, we set out to study the neural systems that detect predictable temporal patterns and departures from them. We used functional magnetic resonance imaging (fMRI to locate activity in the brains of subjects when they viewed temporally regular and irregular patterns produced by letters, numbers, colors and luminance. Activity induced by irregular sequences was located within dorsolateral prefrontal cortex, including an area that was responsive to irregular patterns regardless of the type of visual stimuli producing them. Conversely, temporally regular arrangements resulted in activity in the right frontal lobe (medial frontal gyrus, in the left orbito-frontal cortex and in the left pallidum. The results show that there is an abstractive system in the brain for detecting temporal irregularity, regardless of the source producing it.

  4. Differences between work and leisure in temporal patterns of objectively measured physical activity among blue-collar workers.

    Science.gov (United States)

    Hallman, David M; Mathiassen, Svend Erik; Gupta, Nidhi; Korshøj, Mette; Holtermann, Andreas

    2015-09-28

    Leisure time physical activity (LTPA) is generally associated with favorable cardiovascular health outcomes, while occupational physical activity (OPA) shows less clear, or even opposite, cardiovascular effects. This apparent paradox is not sufficiently understood, but differences in temporal patterns of OPA and LTPA have been suggested as one explanation. Our aim was to investigate the extent to which work and leisure (non-occupational time) differ in temporal activity patterns among blue-collar workers, and to assess the modification of these patterns by age and gender. This study was conducted on a cross-sectional sample of male (n = 108) and female (n = 83) blue-collar workers, aged between 21 and 65 years. Physical activity and sedentary behavior were assessed using accelerometers (Actigraph GT3X+) worn on the thigh and trunk for four consecutive days. Temporal patterns of OPA and LTPA were retrieved using Exposure Variation Analysis (EVA), and expressed in terms of percentage of work and leisure time spent in uninterrupted periods of different durations ( 60 min) of sitting, standing, and walking. Repeated measures ANOVA and linear regression analyses were used to test a) possible differences between OPA and LTPA in selected EVA derivatives, and b) the modification of these differences by age and gender. OPA showed a larger percentage time walking in brief (30 min) sitting [7.0 % (9.3)] than LTPA [walking 15.4 % (5.0); sitting 31.9 % (15.3)], even after adjustment for the difference between work and leisure in total time spent in each activity type. These marked differences in the temporal pattern of OPA and LTPA were modified by gender, but not age. We found that the temporal patterns of OPA and LTPA among blue-collar workers were markedly different even after adjustment for total physical activity time, and that this difference was modified by gender. We recommend using EVA derivatives in future studies striving to disentangle the apparent

  5. Historical manuscript dating based on temporal pattern codebook

    NARCIS (Netherlands)

    He, Sheng; Samara, Petros; Burgers, Jan; Schomaker, Lambert

    2016-01-01

    Manuscript dating is an essential part of historical scholarship. This paper proposes a framework for image-based historical manuscript dating based on handwritten pattern analysis in scanned historical manuscript images. We first use a singular structural feature to extract the mid-level

  6. Temporal Patterns in Seawater Quality from Dredging in Tropical Environments.

    Directory of Open Access Journals (Sweden)

    Ross Jones

    Full Text Available Maintenance and capital dredging represents a potential risk to tropical environments, especially in turbidity-sensitive environments such as coral reefs. There is little detailed, published observational time-series data that quantifies how dredging affects seawater quality conditions temporally and spatially. This information is needed to test realistic exposure scenarios to better understand the seawater-quality implications of dredging and ultimately to better predict and manage impacts of future projects. Using data from three recent major capital dredging programs in North Western Australia, the extent and duration of natural (baseline and dredging-related turbidity events are described over periods ranging from hours to weeks. Very close to dredging i.e. <500 m distance, a characteristic features of these particular case studies was high temporal variability. Over several hours suspended sediment concentrations (SSCs can range from 100-500 mg L-1. Less turbid conditions (10-80 mg L-1 can persist over several days but over longer periods (weeks to months averages were <10 mg L-1. During turbidity events all benthic light was sometimes extinguished, even in the shallow reefal environment, however a much more common feature was very low light 'caliginous' or daytime twilight periods. Compared to pre-dredging conditions, dredging increased the intensity, duration and frequency of the turbidity events by 10-, 5- and 3-fold respectively (at sites <500 m from dredging. However, when averaged across the entire dredging period of 80-180 weeks, turbidity values only increased by 2-3 fold above pre-dredging levels. Similarly, the upper percentile values (e.g., P99, P95 of seawater quality parameters can be highly elevated over short periods, but converge to values only marginally above baseline states over longer periods. Dredging in these studies altered the overall probability density distribution, increasing the frequency of extreme values. As

  7. Temporal and spatial patterns of suicides in Stockholm's subway stations.

    Science.gov (United States)

    Uittenbogaard, Adriaan; Ceccato, Vania

    2015-08-01

    This paper investigates the potential temporal and spatial variations of suicides in subway stations in Stockholm, Sweden. The study also assesses whether the variation in suicide rates is related to the station environments by controlling for each station's location and a number of contextual factors using regression models and geographical information systems (GIS). Data on accidents are used as references for the analysis of suicides. Findings show that suicides tend to occur during the day and in the spring. They are concentrated in the main transportation hubs but, interestingly, during off-peak hours. However, the highest rates of suicides per passenger are found in Stockholm's subway stations located in the Southern outskirts. More than half of the variation in suicide rates is associated with stations that have walls between the two sides of the platform but still allow some visibility from passers-by. The surrounding environment and socioeconomic context show little effect on suicide rates, but stations embedded in areas with high drug-related crime rates tend to show higher suicide rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Visual mining of moving flock patterns in large spatio-temporal data sets using a frequent pattern approach

    NARCIS (Netherlands)

    Turdukulov, U.; Calderon Romero, A.O.; Huisman, O.; Retsios, V.

    2014-01-01

    The popularity of tracking devices continues to contribute to increasing volumes of spatio-temporal data about moving objects. Current approaches in analysing these data are unable to capture collective behaviour and correlations among moving objects. An example of these types of patterns is moving

  9. Empirical analysis on temporal statistics of human correspondence patterns

    Science.gov (United States)

    Li, Nan-Nan; Zhang, Ning; Zhou, Tao

    2008-11-01

    Recently, extensive empirical evidence shows that the timing of human behaviors obeys non-Possion statistics with heavy-tailed interevent time distribution. In this paper, we empirically study the correspondence pattern of a great Chinese scientist, named Hsue-Shen Tsien. Both the interevent time distribution and response time distributions deviate from the Poisson statistics, showing an approximate power-law decaying. The two power-law exponents are more or less the same (about 2.1), which strongly support the hypothesis in [A. Vázquez, J.G. Oliveira, Z. Dezsö, K.-I. Goh, I. Kondor, A.-L. Barabási, Phys. Rev. E 73 (2006) 036127] that the response time distribution of the tasks could in fact drive the interevent time distribution, and both the two distributions should decay with the same exponent. Our result is against the claim in [A. Vázquez, J.G. Oliveira, Z. Dezsö, K.-I. Goh, I. Kondor, A.-L. Barabási, Phys. Rev. E 73 (2006) 036127], which suggests the human correspondence pattern belongs to a universality class with exponent 1.5.

  10. Temporal pattern of stimulation modulates reflex bladder activation by pudendal nerve stimulation.

    Science.gov (United States)

    McGee, Meredith J; Grill, Warren M

    2016-11-01

    Reflex bladder activation and inhibition by electrical stimulation of pudendal nerve (PN) afferents is a promising approach to restore control of bladder function in persons with lower urinary tract dysfunction caused by disease or injury. The objective of this work was to determine whether bladder activation evoked by pudendal afferent stimulation was dependent on the temporal pattern of stimulation, and whether specific temporal patterns of stimulation produced larger bladder contractions than constant frequency stimulation. The mean and maximum contraction pressures evoked by different temporal patterns of stimulation of the dorsal genital branch of the pudendal nerve were measured under isovolumetric conditions in α-chloralose anesthetized cats. A computational model of the spinal neural network mediating the pudendo-vesical reflex was used to understand the mechanisms of different bladder responses to patterned stimulation. The pattern of stimulation significantly affected the magnitude of evoked bladder contractions; several temporal patterns were as effective as regular stimulation, but no pattern evoked larger bladder contractions. Random patterns and patterns with pauses, burst-like activity, or high frequency components evoked significantly smaller bladder contractions, supporting the use of regular frequency stimulation in the development of neural prosthetic approaches for bladder control. These results reveal that the bladder response to pudendal afferent stimulation is dependent on the pattern, as well as the frequency, of stimulation. The computational model revealed that the effects of patterned pudendal afferent stimulation were determined by the dynamic properties of excitatory and inhibitory interneurons in the lumbosacral spinal cord. Neurourol. Urodynam. 35:882-887, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  11. Analysis of spatio-temporal pattern and driving force of land cover change using multi-temporal remote sensing images

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Landuse and land cover change is regarded as a good indicator that represents the impact of human activities on earth’s environment.When the large collection of multi-temporal satellite images has become available,it is possible to study a long-term historical process of land cover change.This study aims to investigate the spatio-temporal pattern and driving force of land cover change in the Pearl River Delta region in southern China,where the rapid development has been witnessed since 1980s.The fast economic growth has been associated with an accelerated expansion of urban landuse,which has been recorded by historical remote sensing images.This paper reports the method and outcome of the research that attempts to model spatio-temporal pattern of land cover change using multi-temporal satellite images.The classified satellite images were compared to detect the change from various landuse types to built-up areas.The trajectories of land cover change have then been established based on the time-series of the classified land cover classes.The correlation between the expansion of built-up areas and selected economic data has also been analysed for better understanding on the driving force of the rapid urbanisation process.The result shows that,since early 1990s,the dominant trend of land cover change has been from farmland to urban landuse.The relationship between economic growth indicator(measured by GDP)and built-up area can well fit into a linear regression model with correlation coefficients greater than 0.9.It is quite clear that cities or towns have been sprawling in general,demonstrating two growth models that were closely related to the economic development stages.

  12. Leaders and followers: Quantifying consistency in spatio-temporal propagation patterns

    CERN Document Server

    Kreuz, Thomas; Pofahl, Martin; Mulansky, Mario

    2016-01-01

    Repetitive spatio-temporal propagation patterns are encountered in fields as wide-ranging as climatology, social communication and network science. In neuroscience, perfectly consistent repetitions of the same global propagation pattern are called a synfire pattern. For any recording of sequences of discrete events (in neuroscience terminology: sets of spike trains) the questions arise how closely it resembles such a synfire pattern and which are the spike trains that lead/follow. Here we address these questions and introduce an algorithm built on two new indicators, termed SPIKE-Order and Spike Train Order, that define the Synfire Indicator value, which allows to sort multiple spike trains from leader to follower and to quantify the consistency of the temporal leader-follower relationships for both the original and the optimized sorting. We demonstrate our new approach using artificially generated datasets before we apply it to analyze the consistency of propagation patterns in two real datasets from neurosc...

  13. Temporal pattern recognition based on instantaneous spike rate coding in a simple auditory system.

    Science.gov (United States)

    Nabatiyan, A; Poulet, J F A; de Polavieja, G G; Hedwig, B

    2003-10-01

    Auditory pattern recognition by the CNS is a fundamental process in acoustic communication. Because crickets communicate with stereotyped patterns of constant frequency syllables, they are established models to investigate the neuronal mechanisms of auditory pattern recognition. Here we provide evidence that for the neural processing of amplitude-modulated sounds, the instantaneous spike rate rather than the time-averaged neural activity is the appropriate coding principle by comparing both coding parameters in a thoracic interneuron (Omega neuron ON1) of the cricket (Gryllus bimaculatus) auditory system. When stimulated with different temporal sound patterns, the analysis of the instantaneous spike rate demonstrates that the neuron acts as a low-pass filter for syllable patterns. The instantaneous spike rate is low at high syllable rates, but prominent peaks in the instantaneous spike rate are generated as the syllable rate resembles that of the species-specific pattern. The occurrence and repetition rate of these peaks in the neuronal discharge are sufficient to explain temporal filtering in the cricket auditory pathway as they closely match the tuning of phonotactic behavior to different sound patterns. Thus temporal filtering or "pattern recognition" occurs at an early stage in the auditory pathway.

  14. Long-period seismic events with strikingly regular temporal patterns on Katla volcano's south flank (Iceland)

    Science.gov (United States)

    Sgattoni, Giulia; Jeddi, Zeinab; Gudmundsson, Ólafur; Einarsson, Páll; Tryggvason, Ari; Lund, Björn; Lucchi, Federico

    2016-09-01

    Katla is a threatening volcano in Iceland, partly covered by the Mýrdalsjökull ice cap. The volcano has a large caldera with several active geothermal areas. A peculiar cluster of long-period seismic events started on Katla's south flank in July 2011, during an unrest episode in the caldera that culminated in a glacier outburst. The seismic events were tightly clustered at shallow depth in the Gvendarfell area, 4 km south of the caldera, under a small glacier stream at the southern margin of Mýrdalsjökull. No seismic events were known to have occurred in this area before. The most striking feature of this seismic cluster is its temporal pattern, characterized by regular intervals between repeating seismic events, modulated by a seasonal variation. Remarkable is also the stability of both the time and waveform features over a long time period, around 3.5 years. We have not found any comparable examples in the literature. Both volcanic and glacial processes can produce similar waveforms and therefore have to be considered as potential seismic sources. Discerning between these two causes is critical for monitoring glacier-clad volcanoes and has been controversial at Katla. For this new seismic cluster on the south flank, we regard volcano-related processes as more likely than glacial ones for the following reasons: 1) the seismic activity started during an unrest episode involving sudden melting of the glacier and a jökulhlaup; 2) the glacier stream is small and stagnant; 3) the seismicity remains regular and stable for years; 4) there is no apparent correlation with short-term weather changes, such as rainstorms. We suggest that a small, shallow hydrothermal system was activated on Katla's south flank in 2011, either by a minor magmatic injection or by changes of permeability in a local crack system.

  15. A Bayesian Hierarchical Model for Spatio-Temporal Prediction and Uncertainty Assessment Using Repeat LiDAR Acquisitions for the Kenai Peninsula, AK, USA

    Science.gov (United States)

    Babcock, C. R.; Andersen, H. E.; Finley, A. O.; Cook, B.; Morton, D. C.

    2015-12-01

    Models using repeat LiDAR and field campaigns may be one mechanism to monitor carbon storage and flux in forested regions. Considering the ability of multi-temporal LiDAR to estimate growth, it is not surprising that there is great interest in developing forest carbon monitoring strategies that rely on repeated LiDAR acquisitions. Allowing for sparser field campaigns, LiDAR stands to make monitoring forest carbon cheaper and more efficient than field-only sampling procedures. Here, we look to the spatio-temporally data-rich Kenai Peninsula in Alaska to examine the potential for Bayesian spatio-temporal mapping of forest carbon storage and uncertainty. The framework explored here can predict forest carbon through space and time, while formally propagating uncertainty through to prediction. Bayesian spatio-temporal models are flexible frameworks allowing for forest growth processes to be formally integrated into the model. By incorporating a mechanism for growth---using temporally repeated field and LiDAR data---we can more fully exploit the information-rich inventory network to improve prediction accuracy. LiDAR data for the Kenai Peninsula has been collected on four different occasions---spatially coincident LiDAR strip samples in 2004, 09 and 14, along with a wall-to-wall collection in 2008. There were 436 plots measured twice between 2002 and 2014. LiDAR was acquired at least once over most inventory plots with many having LiDAR collected during 2, 3 or 4 different campaigns. Results from this research will impact how forests are inventoried. It is too expensive to monitor terrestrial carbon using field-only sampling strategies and currently proposed LiDAR model-based techniques lack the ability to properly utilize temporally repeated and misaligned data. Bayesian hierarchical spatio-temporal models offer a solution to these shortcomings and allow for formal predictive error assessment, which is useful for policy development and decision making.

  16. Temporal Patterns in Fine Particulate Matter Time Series in Beijing: A Calendar View

    Science.gov (United States)

    Liu, Jianzheng; Li, Jie; Li, Weifeng

    2016-08-01

    Extremely high fine particulate matter (PM2.5) concentration has become synonymous to Beijing, the capital of China, posing critical challenges to its sustainable development and leading to major public health concerns. In order to formulate mitigation measures and policies, knowledge on PM2.5 variation patterns should be obtained. While previous studies are limited either because of availability of data, or because of problematic a priori assumptions that PM2.5 concentration follows subjective seasonal, monthly, or weekly patterns, our study aims to reveal the data on a daily basis through visualization rather than imposing subjective periodic patterns upon the data. To achieve this, we conduct two time-series cluster analyses on full-year PM2.5 data in Beijing in 2014, and provide an innovative calendar visualization of PM2.5 measurements throughout the year. Insights from the analysis on temporal variation of PM2.5 concentration show that there are three diurnal patterns and no weekly patterns; seasonal patterns exist but they do not follow a strict temporal division. These findings advance current understanding on temporal patterns in PM2.5 data and offer a different perspective which can help with policy formulation on PM2.5 mitigation.

  17. Characterizing spatial and temporal patterns of intermittent rivers

    Science.gov (United States)

    de Vries, Stefan B.; Hoeve, Jasper; Sauquet, Eric; Leigh, Catherine; Bonada, Núria; Fike, Kimberly; Dahm, Clifford; Booij, Martijn J.; Datry, Thibault

    2015-04-01

    the monitoring strategy, i.e. gauging stations have been primarily installed to measure perennial flows of medium size basins and most of the IRs remain ungauged. This is also true in the US where ~ 7% of the current and historical gage network is on intermittent rivers. - Intermittence of rivers demonstrates high seasonality which varies from one country to another. - Links between climate variability and intermittence are not straightforward. No relation was found between annual DUR and annual precipitation in France whereas DUR was significantly correlated with precipitation in Australia. Potential evapotranspiration was correlated with DUR for France, but not for Australia, where the results were more obscure. - No spatially coherent trends in flow intermittence were identified in Spain, France or the USA. Significant trends according to the Mann Kendall test were found in Australia and results suggest trends in yearly DUR consistent with observed changes in rainfall in Western Australia during the last few decades. The El Nino cycle is one of the possible sources of variability in intermittency patterns.

  18. Time Curves: Folding Time to Visualize Patterns of Temporal Evolution in Data.

    Science.gov (United States)

    Bach, Benjamin; Shi, Conglei; Heulot, Nicolas; Madhyastha, Tara; Grabowski, Tom; Dragicevic, Pierre

    2016-01-01

    We introduce time curves as a general approach for visualizing patterns of evolution in temporal data. Examples of such patterns include slow and regular progressions, large sudden changes, and reversals to previous states. These patterns can be of interest in a range of domains, such as collaborative document editing, dynamic network analysis, and video analysis. Time curves employ the metaphor of folding a timeline visualization into itself so as to bring similar time points close to each other. This metaphor can be applied to any dataset where a similarity metric between temporal snapshots can be defined, thus it is largely datatype-agnostic. We illustrate how time curves can visually reveal informative patterns in a range of different datasets.

  19. Function-based discovery of significant transcriptional temporal patterns in insulin stimulated muscle cells.

    Science.gov (United States)

    Di Camillo, Barbara; Irving, Brian A; Schimke, Jill; Sanavia, Tiziana; Toffolo, Gianna; Cobelli, Claudio; Nair, K Sreekumaran

    2012-01-01

    Insulin action on protein synthesis (translation of transcripts) and post-translational modifications, especially of those involving the reversible modifications such as phosphorylation of various signaling proteins, are extensively studied but insulin effect on transcription of genes, especially of transcriptional temporal patterns remains to be fully defined. To identify significant transcriptional temporal patterns we utilized primary differentiated rat skeletal muscle myotubes which were treated with insulin and samples were collected every 20 min for 8 hours. Pooled samples at every hour were analyzed by gene array approach to measure transcript levels. The patterns of transcript levels were analyzed based on a novel method that integrates selection, clustering, and functional annotation to find the main temporal patterns associated to functional groups of differentially expressed genes. 326 genes were found to be differentially expressed in response to in vitro insulin administration in skeletal muscle myotubes. Approximately 20% of the genes that were differentially expressed were identified as belonging to the insulin signaling pathway. Characteristic transcriptional temporal patterns include: (a) a slow and gradual decrease in gene expression, (b) a gradual increase in gene expression reaching a peak at about 5 hours and then reaching a plateau or an initial decrease and other different variable pattern of increase in gene expression over time. The new method allows identifying characteristic dynamic responses to insulin stimulus, common to a number of genes and associated to the same functional group. The results demonstrate that insulin treatment elicited different clusters of gene transcript profile supporting a temporal regulation of gene expression by insulin in skeletal muscle cells.

  20. Function-based discovery of significant transcriptional temporal patterns in insulin stimulated muscle cells.

    Directory of Open Access Journals (Sweden)

    Barbara Di Camillo

    Full Text Available BACKGROUND: Insulin action on protein synthesis (translation of transcripts and post-translational modifications, especially of those involving the reversible modifications such as phosphorylation of various signaling proteins, are extensively studied but insulin effect on transcription of genes, especially of transcriptional temporal patterns remains to be fully defined. METHODOLOGY/PRINCIPAL FINDINGS: To identify significant transcriptional temporal patterns we utilized primary differentiated rat skeletal muscle myotubes which were treated with insulin and samples were collected every 20 min for 8 hours. Pooled samples at every hour were analyzed by gene array approach to measure transcript levels. The patterns of transcript levels were analyzed based on a novel method that integrates selection, clustering, and functional annotation to find the main temporal patterns associated to functional groups of differentially expressed genes. 326 genes were found to be differentially expressed in response to in vitro insulin administration in skeletal muscle myotubes. Approximately 20% of the genes that were differentially expressed were identified as belonging to the insulin signaling pathway. Characteristic transcriptional temporal patterns include: (a a slow and gradual decrease in gene expression, (b a gradual increase in gene expression reaching a peak at about 5 hours and then reaching a plateau or an initial decrease and other different variable pattern of increase in gene expression over time. CONCLUSION/SIGNIFICANCE: The new method allows identifying characteristic dynamic responses to insulin stimulus, common to a number of genes and associated to the same functional group. The results demonstrate that insulin treatment elicited different clusters of gene transcript profile supporting a temporal regulation of gene expression by insulin in skeletal muscle cells.

  1. Next generation sequencing (NGS database for tandem repeats with multiple pattern 2°-shaft multicore string matching

    Directory of Open Access Journals (Sweden)

    Chinta Someswara Rao

    2016-03-01

    Full Text Available Next generation sequencing (NGS technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching.

  2. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching

    Science.gov (United States)

    Someswara Rao, Chinta; Raju, S. Viswanadha

    2016-01-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats) in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching. PMID:26981434

  3. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching.

    Science.gov (United States)

    Someswara Rao, Chinta; Raju, S Viswanadha

    2016-03-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats) in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching.

  4. Spatio-temporal flow pattern observations using bio-inspired hair flow sensors

    NARCIS (Netherlands)

    Dagamseh, Ahmad; Hmeidi, Sarah; Krijnen, Gijs

    2015-01-01

    In nature, sensing is a fundamental property of virtually all living creatures. For many insects airflow patterns, as observed by means of their hair-sensors, carry highly valuable information exposing the sources of these flows. Flow-sensor arrays can be used to extract spatio-temporal flow fields

  5. Interrelationships Among Warmth, Genuineness, Empathy, And Temporal Speech Patterns In Interpersonal Interaction

    Science.gov (United States)

    Welkowitz, Joan; Kuc, Marta

    1973-01-01

    This study explores interrelationships among ratings by conversational partners and independent observers of empathy, warmth, and genuineness, and relates these ratings to partners' dialogue patterns. The results support the hypothesis that one of the parameters of temporal congruence, switching pauses, relates significantly to ratings of warmth…

  6. Temporal pattern of acoustic imaging noise asymmetrically modulates activation in the auditory cortex.

    Science.gov (United States)

    Ranaweera, Ruwan D; Kwon, Minseok; Hu, Shuowen; Tamer, Gregory G; Luh, Wen-Ming; Talavage, Thomas M

    2016-01-01

    This study investigated the hemisphere-specific effects of the temporal pattern of imaging related acoustic noise on auditory cortex activation. Hemodynamic responses (HDRs) to five temporal patterns of imaging noise corresponding to noise generated by unique combinations of imaging volume and effective repetition time (TR), were obtained using a stroboscopic event-related paradigm with extra-long (≥27.5 s) TR to minimize inter-acquisition effects. In addition to confirmation that fMRI responses in auditory cortex do not behave in a linear manner, temporal patterns of imaging noise were found to modulate both the shape and spatial extent of hemodynamic responses, with classically non-auditory areas exhibiting responses to longer duration noise conditions. Hemispheric analysis revealed the right primary auditory cortex to be more sensitive than the left to the presence of imaging related acoustic noise. Right primary auditory cortex responses were significantly larger during all the conditions. This asymmetry of response to imaging related acoustic noise could lead to different baseline activation levels during acquisition schemes using short TR, inducing an observed asymmetry in the responses to an intended acoustic stimulus through limitations of dynamic range, rather than due to differences in neuronal processing of the stimulus. These results emphasize the importance of accounting for the temporal pattern of the acoustic noise when comparing findings across different fMRI studies, especially those involving acoustic stimulation.

  7. Comparison of the temporal release pattern of copeptin with conventional biomarkers in acute myocardial infarction

    NARCIS (Netherlands)

    Y.L. Gu (Youlan); A.A. Voors (Adriaan); F. Zijlstra (Felix); H.L. Hillege (Hans); J. Struck (Joachim); S. Masson (Serge); T. Vago (Tarcisio); S.D. Anker (Stefan); A.F.M. van den Heuvel (Ad); D.J. van Veldhuisen (Dirk); B.J.G.L. de Smet (Bart)

    2011-01-01

    textabstractBackground Early detection of acute myocardial infarction (AMI) using cardiac biomarkers of myocardial necrosis remains limited since these biomarkers do not rise within the first hours from onset of AMI. We aimed to compare the temporal release pattern of the C-terminal portion of prova

  8. Comparison of the temporal release pattern of copeptin with conventional biomarkers in acute myocardial infarction

    NARCIS (Netherlands)

    Gu, Youlan L.; Voors, Adriaan A.; Zijlstra, Felix; Hillege, Hans L.; Struck, Joachim; Masson, Serge; Vago, Tarcisio; Anker, Stefan D.; van den Heuvel, Ad F. M.; van Veldhuisen, Dirk J.; de Smet, Bart J. G. L.

    2011-01-01

    Background Early detection of acute myocardial infarction (AMI) using cardiac biomarkers of myocardial necrosis remains limited since these biomarkers do not rise within the first hours from onset of AMI. We aimed to compare the temporal release pattern of the C-terminal portion of provasopressin (c

  9. Temporal stability of Escherichia coli concentration patterns in two irrigation ponds in Maryland

    Science.gov (United States)

    Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. We hypothesized that there is a temporally stable pattern of E.coli concentrations ...

  10. Extreme variation in patterns of tandem repeats in mitochondrial control region of yellow-browed tits (Sylviparus modestus, Paridae).

    Science.gov (United States)

    Wang, Xiaoyang; Liu, Nian; Zhang, Hongli; Yang, Xiao-Jun; Huang, Yuan; Lei, Fumin

    2015-08-19

    To investigate the evolutionary pattern and origins of tandem repeats in the mitochondrial control region of the yellow-browed tit (Sylviparus modestus), the control region and another four mitochondrial loci from fifteen individuals were analyzed. A 117-bp tandem repeat unit that repeated once, twice or three times in different individuals was found, and a rarely reported arrangement for this tandem repeats region that a 5' imperfect copy at its downstream and a 3' imperfect copy at its upstream was observed. The haplotype network, phylogenetic trees, and ancestral state reconstruction of the combined dataset of five loci suggested multiple origins of the same repeat number. The turnover model via slipped-strand mispairing was introduced to interpret the results, because mispairing occurred so frequently that multiple origins of certain repeat number were observed. Insertion via recombination should be a better explanation for the origin of this tandem repeat unit, considering characteristics of the combined sequence of the 3' and 5' imperfect copy, including identification of its homolog in other passerines and its predicted secondary structure.

  11. Prospective study on determinants of repeat attendance and attendance patterns in breast cancer screening using the Theory of Planned Behaviour.

    NARCIS (Netherlands)

    Drossaert, Constance H.C.; Boer, Hendrik; Seydel, E.R.

    2003-01-01

    This prospective study, using the Theory of Planned Behaviour (TPB) as a theoretical framework, was carried out to identify the determinants of repeat attendance and attendance patterns in organised breast screening. A group of 2657 women filled out a baseline questionnaire, approximately 8 weeks

  12. Spatial and temporal patterns of air pollutants in rural and urban areas of India.

    Science.gov (United States)

    Sharma, Disha; Kulshrestha, U C

    2014-12-01

    In this study, we analysed spatial and temporal patterns of Suspended Particulate Matter (SPM) concentrations across India. We have also assessed MODIS-derived aerosol optical depth (AOD) variations to characterize the air quality and relate it to SPM, NO2 and SO2 in different areas. In addition, the pollutant concentrations have been mapped using geospatial techniques. The results indicated significant differences in air pollutant levels across rural and urban areas. In general, districts of central and northern India had relatively higher SPM concentrations compared to southern India. Out of the top ten SPM polluted districts in India, nine were located in the state of Uttar Pradesh (UP). We observed significant correlations between the SPM and AOD at different sites. Although spatial and temporal patterns of NO2 and SO2 matched AOD patterns, the correlation strength (r2) varied based on location. The causes and implications of these findings are presented.

  13. Temporal feeding pattern may influence reproduction efficiency, the example of breeding mares.

    Science.gov (United States)

    Benhajali, Haifa; Ezzaouia, Mohammed; Lunel, Christophe; Charfi, Faouzia; Hausberger, Martine

    2013-01-01

    Discomfort in farm animals may be induced by inappropriate types or timing of food supplies. Thus, time restriction of meals and lack of roughage have been shown to be one source of emergence of oral stereotypies and abnormal behaviour in horses which have evolved to eat high-fibre diets in small amounts over long periods of time. This feeding pattern is often altered in domestic environment where horses are often fed low fibre meals that can be rapidly consumed. This study aimed at determining the effect of the temporal pattern of feeding on reproductive efficiency of breeding mares, One hundred Arab breeding mares were divided into two groups that differed only in the temporal pattern of roughage availability: only at night for the standard feeding pattern group (SFP mares), night and day for the "continuous feeding" group (CF mares). The total amount of roughage provided was the same as the CF mares received half of the hay during the day while in paddock (haynets). Mares were tested for oestrus detection by teasing with one stallion and were then examined clinically by rectal palpations and ultrasound before being mated naturally or inseminated by fresh or frozen semen. Multivariate logistic regression was used to analyse data. The treatment affected significantly the reproductive efficiency of the mares with fewer oestrus abnormalities (p = 0.0002) and more fertility (p = 0.024) in CF mares (conception rate = 81% versus 55% in SFP mares). Ensuring semi-continous feeding by providing roughage may be a way of fulfilling the basic physiological needs of the horses' digestive system, reducing stress and associated inhibitors of reproduction. To our knowledge, this study provides the first evidence of an impact of temporal feeding patterns on reproductive success in a Mammal. Temporal patterns of feeding may be a major and underestimated factor in breeding.

  14. Temporal feeding pattern may influence reproduction efficiency, the example of breeding mares.

    Directory of Open Access Journals (Sweden)

    Haifa Benhajali

    Full Text Available Discomfort in farm animals may be induced by inappropriate types or timing of food supplies. Thus, time restriction of meals and lack of roughage have been shown to be one source of emergence of oral stereotypies and abnormal behaviour in horses which have evolved to eat high-fibre diets in small amounts over long periods of time. This feeding pattern is often altered in domestic environment where horses are often fed low fibre meals that can be rapidly consumed. This study aimed at determining the effect of the temporal pattern of feeding on reproductive efficiency of breeding mares, One hundred Arab breeding mares were divided into two groups that differed only in the temporal pattern of roughage availability: only at night for the standard feeding pattern group (SFP mares, night and day for the "continuous feeding" group (CF mares. The total amount of roughage provided was the same as the CF mares received half of the hay during the day while in paddock (haynets. Mares were tested for oestrus detection by teasing with one stallion and were then examined clinically by rectal palpations and ultrasound before being mated naturally or inseminated by fresh or frozen semen. Multivariate logistic regression was used to analyse data. The treatment affected significantly the reproductive efficiency of the mares with fewer oestrus abnormalities (p = 0.0002 and more fertility (p = 0.024 in CF mares (conception rate = 81% versus 55% in SFP mares. Ensuring semi-continous feeding by providing roughage may be a way of fulfilling the basic physiological needs of the horses' digestive system, reducing stress and associated inhibitors of reproduction. To our knowledge, this study provides the first evidence of an impact of temporal feeding patterns on reproductive success in a Mammal. Temporal patterns of feeding may be a major and underestimated factor in breeding.

  15. The statistics of repeating patterns of cortical activity can be reproduced by a model network of stochastic binary neurons.

    Science.gov (United States)

    Roxin, Alex; Hakim, Vincent; Brunel, Nicolas

    2008-10-15

    Calcium imaging of the spontaneous activity in cortical slices has revealed repeating spatiotemporal patterns of transitions between so-called down states and up states (Ikegaya et al., 2004). Here we fit a model network of stochastic binary neurons to data from these experiments, and in doing so reproduce the distributions of such patterns. We use two versions of this model: (1) an unconnected network in which neurons are activated as independent Poisson processes; and (2) a network with an interaction matrix, estimated from the data, representing effective interactions between the neurons. The unconnected model (model 1) is sufficient to account for the statistics of repeating patterns in 11 of the 15 datasets studied. Model 2, with interactions between neurons, is required to account for pattern statistics of the remaining four. Three of these four datasets are the ones that contain the largest number of transitions, suggesting that long datasets are in general necessary to render interactions statistically visible. We then study the topology of the matrix of interactions estimated for these four datasets. For three of the four datasets, we find sparse matrices with long-tailed degree distributions and an overrepresentation of certain network motifs. The remaining dataset exhibits a strongly interconnected, spatially localized subgroup of neurons. In all cases, we find that interactions between neurons facilitate the generation of long patterns that do not repeat exactly.

  16. Robust Speech Recognition Using Temporal Pattern Feature Extracted From MTMLP Structure

    Directory of Open Access Journals (Sweden)

    Yasser Shekofteh

    2014-10-01

    Full Text Available Temporal Pattern feature of a speech signal could be either extracted from the time domain or via their front-end vectors. This feature includes long-term information of variations in the connected speech units. In this paper, the second approach is followed, i.e. the features which are the cases of temporal computations, consisting of Spectral-based (LFBE and Cepstrum-based (MFCC feature vectors, are considered. To extract these features, we use posterior probability-based output of the proposed MTMLP neural networks. The combination of the temporal patterns, which represents the long-term dynamics of the speech signal, together with some traditional features, composed of the MFCC and its first and second derivatives are evaluated in an ASR task. It is shown that the use of such a combined feature vector results in the increase of the phoneme recognition accuracy by more than 1 percent regarding the results of the baseline system, which does not benefit from the long-term temporal patterns. In addition, it is shown that the use of extracted features by the proposed method gives robust recognition under different noise conditions (by 13 percent and, therefore, the proposed method is a robust feature extraction method.

  17. COMPOSE: Using temporal patterns for interpreting wearable sensor data with computer interpretable guidelines.

    Science.gov (United States)

    Urovi, V; Jimenez-Del-Toro, O; Dubosson, F; Ruiz Torres, A; Schumacher, M I

    2017-02-01

    This paper describes a novel temporal logic-based framework for reasoning with continuous data collected from wearable sensors. The work is motivated by the Metabolic Syndrome, a cluster of conditions which are linked to obesity and unhealthy lifestyle. We assume that, by interpreting the physiological parameters of continuous monitoring, we can identify which patients have a higher risk of Metabolic Syndrome. We define temporal patterns for reasoning with continuous data and specify the coordination mechanisms for combining different sets of clinical guidelines that relate to this condition. The proposed solution is tested with data provided by twenty subjects, which used sensors for four days of continuous monitoring. The results are compared to the gold standard. The novelty of the framework stands in extending a temporal logic formalism, namely the Event Calculus, with temporal patterns. These patterns are helpful to specify the rules for reasoning with continuous data and in combining new knowledge into one consistent outcome that is tailored to the patient's profile. The overall approach opens new possibilities for delivering patient-tailored interventions and educational material before the patients present the symptoms of the disease.

  18. Temporal Stability of Sward Dry Matter and Nitrogen Yield Patterns in a Temperate Grassland

    Institute of Scientific and Technical Information of China (English)

    XU Hong-Wei; WANG Ke; J.S.BAILEY; C.JORDAN; A.WTTHERS

    2006-01-01

    The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen(N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast,at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.

  19. Developmental regulation of spatio-temporal patterns of cortical circuit activation

    Directory of Open Access Journals (Sweden)

    Trevor Charles Griffen

    2013-01-01

    Full Text Available Neural circuits are refined in an experience-dependent manner during early postnatal development. How development modulates the spatio-temporal propagation of activity through cortical circuits is poorly understood. Here we use voltage sensitive dye imaging (VSD to show that there are significant changes in the spatio-temporal patterns of intracortical signals in primary visual cortex from postnatal day 13 (P13, eye opening, to P28, the peak of the critical period for rodent visual cortical plasticity. Upon direct stimulation of layer 4 (L4, activity spreads to L2/3 and to L5 at all ages. However, while from eye opening to the peak of the critical period, the amplitude and persistence of the voltage signal decrease, peak activation is reached more quickly and the interlaminar gain increases with age. The lateral spread of activation within layers remains unchanged throughout the time window under analysis. These developmental changes in spatio-temporal patterns of intracortical circuit activation are mediated by differences in the contributions of excitatory and inhibitory synaptic components. Our results demonstrate that after eye opening the circuit in primary visual cortex is refined through a progression of changes that shape the spatio-temporal patterns of circuit activation. Signals become more efficiently propagated across layers through developmentally regulated changes in interlaminar gain.

  20. Tri-allelic pattern of short tandem repeats identifies the murderer among identical twins and suggests an embryonic mutational origin.

    Science.gov (United States)

    Wang, Li-Feng; Yang, Ying; Zhang, Xiao-Nan; Quan, Xiao-Liang; Wu, Yuan-Ming

    2015-05-01

    Monozygotic twins can be co-identified by genotyping of short tandem repeats (STRs); however, for distinguishing them, STR genotyping is ineffective, especially in the case of murder. Here, a rarely occurring tri-allelic pattern in the vWA locus (16, 18, 19) was identified only in the DNA of one identical twin, which could help to exonerate the innocent twin in a murder charge. This mutation was defined as primary through genotyping of the family and could be detected in blood, buccal and semen samples from the individual; however, two alternative allele-balanced di-allelic patterns (16, 18 or 16, 19) were detected in hair root sheath cells. Such a kind of segregation indicates a one-step mutation occurs in cell mitosis, which is after embryonic zygote formation and during the early development of the individual after the division of the blastocyte. Sequencing revealed the insertion between the allele 18 and 19 is a repeat unit of TAGA/TCTA (plus/minus strand), which belongs to "AGAT/ATCT"-based core repeats identified from all tri-allelic pattern reports recorded in the STR base and a detailed model was proposed for STR repeat length variation caused by false priming during DNA synthesis. Our model illustrates the possible origination of allele-balanced and unbalanced tri-allelic pattern, clarifies that the genotypes of parent-child mismatches, aberrant di-allelic patterns, and type 1 or 2 tri-allelic patterns should be considered as independent, but interconnected forms of STR mutation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Spatio-temporal patterns and predictions of phytoplankton assemblages in a subtropical river delta system

    DEFF Research Database (Denmark)

    Wang, Chao; Li, Xinhui; Wang, Xiangxiu;

    2016-01-01

    similarities. These groups were distinct with respect to species richness, biomass and indicators, especially for groups representing spatial dimension. The Linear Discriminant Analysis (LDA) model indicated that the spatial patterns of phytoplankton assemblages were mostly explained by water quality variables...... dominate? Are physical or chemical factors determining the above patterns in this area? We conclude that the spatial-temporal patterns of phytoplankton in the PRD are closely associated with eutrophication levels caused by anthropogenic activities. The spatial patterns are apparently dominant in this area......Spatial and seasonal sampling within a subtropical river delta system, the Pearl River Delta (China), provided data to determine seasonal phytoplankton patterns and develop prediction models. The high nutrient levels and frequent water exchanges resulted in a phytoplankton community with greatest...

  2. Are temporal patterns of sitting associated with obesity among blue-collar workers? A cross sectional study using accelerometers

    DEFF Research Database (Denmark)

    Gupta, Nidhi; Hallman, David M; Mathiassen, Svend Erik

    2016-01-01

    Background: Little is known about associations of temporal patterns of sitting (i.e., distribution of sitting across time) with obesity. We aimed investigating the association between temporal patterns of sitting (long, moderate and brief uninterrupted bouts) and obesity indicators (body mass ind...

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

    Science.gov (United States)

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

    2000-01-01

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

  4. Spatial and temporal patterns of nonvolcanic tremor along the southern Cascadia subduction zone

    Science.gov (United States)

    Boyarko, Devin C.; Brudzinski, Michael R.

    2010-08-01

    Episodic tremor and slip (ETS), the spatial and temporal correlation of slow slip events monitored via GPS surface displacements and nonvolcanic tremor (NVT) monitored via seismic signals, is a newly discovered mode of deformation thought to be occurring downdip from the seismogenic zone along several subduction zone megathrusts. To provide overall constraints on the distribution and migration behavior of NVT in southern Cascadia, we apply a semiautomated location algorithm to seismic data available during the EarthScope Transportable Array deployment to detect the most prominent pulses of NVT and invert analyst-refined relative arrival times for source locations. In the processing, we also detect distinct and isolated bursts of energy within the tremor similar to observations of low-frequency earthquakes in southwest Japan. We investigate in detail eight NVT episodes between November 2005 and August 2007 with source locations extending over a 650 km along-strike region from northern California to northern Oregon. We find complex tremor migration patterns with periods of steady migration (4-10 km/d), halting, and frequent along-strike jumps (30-400 km) in activity. The initiation and termination points of laterally continuous tremor activity appear to be repeatable features between NVT episodes which support the hypothesis of segmentation within the ETS zone. The overall distribution of NVT epicenters occur within a narrow band primarily confined by the surface projections of the 30 and 40 km contours of the subducting plate interface. We find as much as 50 km spatial offset from the updip edge of the tremor source zone to the downdip edge of the thermally and geodetically defined transition zone, which may inhibit ETS from triggering earthquakes further updip. Intriguingly, NVT activity is spatially anticorrelated with local seismicity, suggesting the two processes are mutually exclusive. We propose that the transition in frictional behavior coupled with high pore

  5. A three-dimensional spatio-temporal EEG pattern analyzing system

    Institute of Scientific and Technical Information of China (English)

    LIU Hesheng; GAO Xiaorong; YANG Fusheng

    2003-01-01

    Spatio-temporal pattern analysis of EEG is an important tool in brain research. An EEG pattern analysis system based on a hierarchical multi-method approach is proposed here. The system consists of multiple steps including extraction of target signal, acquisition of intracranial electric activity distribution, adaptive segmentation of EEG and spatio-temporal pattern recognition. Some modern signal processing methods such as common spatial subspace decomposition, hidden Markov model are adopted. This paper also proposes an algorithm named LORETA-FOCUSS to estimate the current density inside the brain with a high spatial resolution. Microstate analysis of EEG is extended to the 3-D situation. The system was applied to the brain computer interface problem and achieved the highest accuracy of 88.89% with an average accuracy of 81.48% when classifying two imaginary movement tasks, while the data were not manually pre-selected. The result has proved spatio-temporal EEG pattern analysis is an efficient way in brain research.

  6. Spatial and temporal air quality pattern recognition using environmetric techniques: a case study in Malaysia.

    Science.gov (United States)

    Syed Abdul Mutalib, Sharifah Norsukhairin; Juahir, Hafizan; Azid, Azman; Mohd Sharif, Sharifah; Latif, Mohd Talib; Aris, Ahmad Zaharin; Zain, Sharifuddin M; Dominick, Doreena

    2013-09-01

    The objective of this study is to identify spatial and temporal patterns in the air quality at three selected Malaysian air monitoring stations based on an eleven-year database (January 2000-December 2010). Four statistical methods, Discriminant Analysis (DA), Hierarchical Agglomerative Cluster Analysis (HACA), Principal Component Analysis (PCA) and Artificial Neural Networks (ANNs), were selected to analyze the datasets of five air quality parameters, namely: SO2, NO2, O3, CO and particulate matter with a diameter size of below 10 μm (PM10). The three selected air monitoring stations share the characteristic of being located in highly urbanized areas and are surrounded by a number of industries. The DA results show that spatial characterizations allow successful discrimination between the three stations, while HACA shows the temporal pattern from the monthly and yearly factor analysis which correlates with severe haze episodes that have happened in this country at certain periods of time. The PCA results show that the major source of air pollution is mostly due to the combustion of fossil fuel in motor vehicles and industrial activities. The spatial pattern recognition (S-ANN) results show a better prediction performance in discriminating between the regions, with an excellent percentage of correct classification compared to DA. This study presents the necessity and usefulness of environmetric techniques for the interpretation of large datasets aiming to obtain better information about air quality patterns based on spatial and temporal characterizations at the selected air monitoring stations.

  7. Tracking pedestrians using local spatio-temporal motion patterns in extremely crowded scenes.

    Science.gov (United States)

    Kratz, Louis; Nishino, Ko

    2012-05-01

    Tracking pedestrians is a vital component of many computer vision applications, including surveillance, scene understanding, and behavior analysis. Videos of crowded scenes present significant challenges to tracking due to the large number of pedestrians and the frequent partial occlusions that they produce. The movement of each pedestrian, however, contributes to the overall crowd motion (i.e., the collective motions of the scene's constituents over the entire video) that exhibits an underlying spatially and temporally varying structured pattern. In this paper, we present a novel Bayesian framework for tracking pedestrians in videos of crowded scenes using a space-time model of the crowd motion. We represent the crowd motion with a collection of hidden Markov models trained on local spatio-temporal motion patterns, i.e., the motion patterns exhibited by pedestrians as they move through local space-time regions of the video. Using this unique representation, we predict the next local spatio-temporal motion pattern a tracked pedestrian will exhibit based on the observed frames of the video. We then use this prediction as a prior for tracking the movement of an individual in videos of extremely crowded scenes. We show that our approach of leveraging the crowd motion enables tracking in videos of complex scenes that present unique difficulty to other approaches.

  8. Instruction in learning a temporal pattern on an anticipation-coincidence task.

    Science.gov (United States)

    Albinet, C; Fezzani, K

    2003-08-01

    Using a computer-simulated anticipation-coincidence task, the main aim of the study was to examine the effect of the type of instruction on learning a temporal pattern. For this task, participants must learn to anticipate the appropriate time to launch a projectile to hit a moving target. The experiment involved three instructional conditions. In the Explicit-rule Discover Instruction Condition participants were informed that target speed could change from trial to trial and that change is controlled by a regular pattern. Their task was then to search, to identify, and to use such pattern to enhance their anticipation. In the Explicit-Informative Instruction Condition, participants were, however, allowed before practice to examine attentively the regular pattern. Participants were also explicitly urged to use the pattern they observed to ensure a better interception of the target. Finally, in the Implicit Instruction Condition, participants were only informed that their task was to hit, or at least, to place the projectile as near as possible to the target. No additional information was provied about the target's behaviour. Analysis indicated that learning the temporal pattern was more important in Implicit than in Explicit-rule Discover Instruction Condion. However, the Explicit-Informative Instruction Condition produced unambiguouslly the highest learning. Overall, the study highlights the role of information over guidance in the understanding of the effect of the instructions on learning. Finally, we discussed the implications of these results on the comprehension of the variability of the effects of the instruction on learning.

  9. Effects of varying temporal scale on spatial models of mortality patterns attributed to pediatric diarrhea

    Science.gov (United States)

    Leyk, S; McCormick, BJJ; Nuckols, JR

    2011-01-01

    Public health data is often highly aggregated in time and space. The consequences of temporal aggregation for modeling in support of policy decisions have largely been overlooked. We examine the effects of changing temporal scale on spatial regression models of pediatric diarrhea mortality patterns, mortality rates and mortality peak timing, in Mexico. We compare annual and decadal level univariate models that incorporate known risk factors. Based on normalized sums of squared differences we compare between annual and decadal coefficients for variables that were significant in decadal models. We observed that spurious relationships might be created through aggregating time scales; eliminating inter-annual variation and resulting in inflated model diagnostics. In fact, variable selection and coefficient values can vary with changing temporal aggregation. Some variables that were significant at the decadal level were not significant at the annual level. Implications of such aggregation should be part of risk communication to policy makers. PMID:22623950

  10. Spatial-Temporal Patterns in a Dielectric Barrier Discharge under Narrow Boundary Conditions in Argon at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    LI Xue-Chen; JIA Peng-Ying; ZHAO Na

    2011-01-01

    @@ Pattern formation phenomena are investigated in a dielectric barrier discharge under narrow boundary conditions in argon at atmospheric pressure.The discharge shows various scenarios with the increasing applied voltage.This is the first observation of alternating single spot and pair spots pattern and of a moving striation pattern in a dielectric barrier discharge system.The spatial-temporal correlations between discharge filaments in these patterns are measured by an optical method.The results show that the zigzag pattern is an interleaving of two sub-structure patterns, which ignites once for each sub-pattern per half cycle of the applied voltage.There is a temporal sequence inversion in consecutive half-cycles for the two sub-patterns.The pattern of alternating single spot and pair spots is also an interleaving of two sub-structure patterns.However, the pair spots sub-pattern ignites twice and the single spot sub-pattern ignites once per half cycle of the applied voltage.%Pattern formation phenomena are investigated in a dielectric barrier discharge under narrow boundary conditions in argon at atmospheric pressure. The discharge shows various scenarios with the increasing applied voltage.This is the first observation of alternating single spot and pair spots pattern and of a moving striation pattern in a dielectric barrier discharge system. The spatial-temporal correlations between discharge filaments in these patterns are measured by an optical method. The results show that the zigzag pattern is an interleaving of two sub-structure patterns, which ignites once for each sub-pattern per half cycle of the applied voltage. There is a temporal sequence inversion in consecutive half-cycles for the two sub-patterns. The pattern of alternating single spot and pair spots is also an interleaving of two sub-structure patterns. However, the pair spots sub-pattern ignites twice and the single spot sub-pattern ignites once per half cycle of the applied voltage.

  11. Temporal patterns of native Mandarin Chinese speakers' productions of English stop-vowel syllable

    Science.gov (United States)

    Wang, Yue; Behne, Dawn M.

    2004-05-01

    Second language (L2) production can be a kind of interlanguage, a relatively stable system bearing the nature of both the native language (L1) and L2. Within such a system sound components of a syllable may bear their own interlanguage characteristics and yet interact with the other component sounds. The present study investigates temporal patterns of L1-L2 interaction at the syllable level. Audio recordings were made of English stop-vowel syllables produced by native speakers of Mandarin who were fluent in English (ChE). Native English productions (AmE) of these syllables and native productions of Mandarin (ChM) stop-vowel syllables were acquired as native norms. Temporal measures included stop closure duration, voice-onset time (VOT), vowel duration, and syllable duration. Results show that the internal timing components of ChE often deviate from AmE, with the closure duration, VOT, and vowel duration being intermediate to AmE and ChM. However, at the syllable level, ChE productions tend to follow the overall patterns of AmE. Temporal deviations were often compensated by temporal compensation of other components in the syllable, maintaining a balanced consonant/vowel distribution. These findings have implications for a broader understanding of L2 productions.

  12. Reliability of spatial and temporal patterns of C. finmarchicus inferred from the CPR survey

    Science.gov (United States)

    Hélaouët, Pierre; Beaugrand, Grégory; Reygondeau, Gabriel

    2016-01-01

    The Continuous Plankton Recorder (CPR) survey has collected plankton since 1958 in the North Atlantic Ocean and its adjacent seas. Among all species recorded by the CPR, Calanus finmarchicus has probably been the most investigated species because of its ecological importance for the temperate and subpolar regions of the North Atlantic Ocean. However, abundances of C. finmarchicus assessed from the CPR survey have been rarely compared to more traditional sampling methodologies. In this study, we examine and compare spatial (surface and vertical) and temporal (diel and seasonal) patterns in the abundance of C. finmarchicus with another sampling technique in the gulf of Maine. Our results provide evidence that the CPR survey not only gives internally consistent time series of C. finmarchicus, but also an accurate representation of both spatial (surface and vertical) and temporal (diel and seasonal) patterns.

  13. Temporal metastates are associated with differential patterns of time-resolved connectivity, network topology, and attention.

    Science.gov (United States)

    Shine, James M; Koyejo, Oluwasanmi; Poldrack, Russell A

    2016-08-30

    Little is currently known about the coordination of neural activity over longitudinal timescales and how these changes relate to behavior. To investigate this issue, we used resting-state fMRI data from a single individual to identify the presence of two distinct temporal states that fluctuated over the course of 18 mo. These temporal states were associated with distinct patterns of time-resolved blood oxygen level dependent (BOLD) connectivity within individual scanning sessions and also related to significant alterations in global efficiency of brain connectivity as well as differences in self-reported attention. These patterns were replicated in a separate longitudinal dataset, providing additional supportive evidence for the presence of fluctuations in functional network topology over time. Together, our results underscore the importance of longitudinal phenotyping in cognitive neuroscience.

  14. Carbon and nitrogen dynamics in agroforestry systems. Temporal patterns of some important soil processes

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, Gert [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Forest Ecology

    2001-07-01

    The ameliorative effects of different tree species on soils in some agroforestry systems were studied. The temporal pattern of nutrient release from tree organic material is important to achieve synchrony with crop uptake. When, as in many tropical agroforestry systems, trees (C{sub 3}-plants) are planted on C{sub 4}-carbon dominated soils, the difference of around 12-16 per mille in natural abundance of {sup 13}C between C{sub 3} and C{sub 4} plants makes the natural abundance of {sup 13}C a particularly sensitive indicator of the influence of trees on the soil. An increase of 3-5% of the percentage C was proven to derive from trees by this method, only five years after planting. By using the difference of around 10 per mille in natural abundance of {sup 13}C between the endogenous soil C (mainly C{sub 4}) and the applied C (C{sub 3}) in green manure experiments, the contributions of the two C sources to soil respiration can be calculated. The microbial response to the additions of leaves was an immediate increase in respiration. This non-destructive method allows repeated measurements of the actual rate of C mineralisation and facilitates decomposition studies with high temporal resolution in the field. The mineralisation of N was also very rapid and the concentration of NH{sub 4}{sup +} in the soil correlated well with respiration of added C. In our studies, 3-4% of the added C was respired daily, for the first 10 days after addition of Sesbania sesban leaves. Although respiration rates decline with time, we estimated 70-90% to be respired in as short time as 40 days. Weight losses of around 80% after 52 days, from high quality residues in litter bags, also indicate substantial C losses. Measurable build-up of soil organic matter is, hence, unlikely. For immediate soil fertility, addition of high quality green manure may, however, be a viable management option. To achieve synchrony with crop demand, caution is needed in management as large amounts of N are

  15. A Sequence Identification Measurement Model to Investigate the Implicit Learning of Metrical Temporal Patterns

    Science.gov (United States)

    Schultz, Benjamin G.; Stevens, Catherine J.; Keller, Peter E.; Tillmann, Barbara

    2013-01-01

    Implicit learning (IL) occurs unconsciously and without intention. Perceptual fluency is the ease of processing elicited by previous exposure to a stimulus. It has been assumed that perceptual fluency is associated with IL. However, the role of perceptual fluency following IL has not been investigated in temporal pattern learning. Two experiments by Schultz, Stevens, Keller, and Tillmann demonstrated the IL of auditory temporal patterns using a serial reaction-time task and a generation task based on the process dissociation procedure. The generation task demonstrated that learning was implicit in both experiments via motor fluency, that is, the inability to suppress learned information. With the aim to disentangle conscious and unconscious processes, we analyze unreported recognition data associated with the Schultz et al. experiments using the sequence identification measurement model. The model assumes that perceptual fluency reflects unconscious processes and IL. For Experiment 1, the model indicated that conscious and unconscious processes contributed to recognition of temporal patterns, but that unconscious processes had a greater influence on recognition than conscious processes. In the model implementation of Experiment 2, there was equal contribution of conscious and unconscious processes in the recognition of temporal patterns. As Schultz et al. demonstrated IL in both experiments using a generation task, and the conditions reported here in Experiments 1 and 2 were identical, two explanations are offered for the discrepancy in model and behavioral results based on the two tasks: 1) perceptual fluency may not be necessary to infer IL, or 2) conscious control over implicitly learned information may vary as a function of perceptual fluency and motor fluency. PMID:24086461

  16. A sequence identification measurement model to investigate the implicit learning of metrical temporal patterns.

    Directory of Open Access Journals (Sweden)

    Benjamin G Schultz

    Full Text Available Implicit learning (IL occurs unconsciously and without intention. Perceptual fluency is the ease of processing elicited by previous exposure to a stimulus. It has been assumed that perceptual fluency is associated with IL. However, the role of perceptual fluency following IL has not been investigated in temporal pattern learning. Two experiments by Schultz, Stevens, Keller, and Tillmann demonstrated the IL of auditory temporal patterns using a serial reaction-time task and a generation task based on the process dissociation procedure. The generation task demonstrated that learning was implicit in both experiments via motor fluency, that is, the inability to suppress learned information. With the aim to disentangle conscious and unconscious processes, we analyze unreported recognition data associated with the Schultz et al. experiments using the sequence identification measurement model. The model assumes that perceptual fluency reflects unconscious processes and IL. For Experiment 1, the model indicated that conscious and unconscious processes contributed to recognition of temporal patterns, but that unconscious processes had a greater influence on recognition than conscious processes. In the model implementation of Experiment 2, there was equal contribution of conscious and unconscious processes in the recognition of temporal patterns. As Schultz et al. demonstrated IL in both experiments using a generation task, and the conditions reported here in Experiments 1 and 2 were identical, two explanations are offered for the discrepancy in model and behavioral results based on the two tasks: 1 perceptual fluency may not be necessary to infer IL, or 2 conscious control over implicitly learned information may vary as a function of perceptual fluency and motor fluency.

  17. Relationship between Musical Characteristics and Temporal Breathing Pattern in Piano Performance

    OpenAIRE

    Yutaka Sakaguchi; Eriko Aiba

    2016-01-01

    Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale,...

  18. Spatio-temporal patterns with hyperchaotic dynamics in diffusively coupled biochemical oscillators

    Directory of Open Access Journals (Sweden)

    Gerold Baier

    1997-01-01

    Full Text Available We present three examples how complex spatio-temporal patterns can be linked to hyperchaotic attractors in dynamical systems consisting of nonlinear biochemical oscillators coupled linearly with diffusion terms. The systems involved are: (a a two-variable oscillator with two consecutive autocatalytic reactions derived from the Lotka–Volterra scheme; (b a minimal two-variable oscillator with one first-order autocatalytic reaction; (c a three-variable oscillator with first-order feedback lacking autocatalysis. The dynamics of a finite number of coupled biochemical oscillators may account for complex patterns in compartmentalized living systems like cells or tissue, and may be tested experimentally in coupled microreactors.

  19. Leaders and followers: quantifying consistency in spatio-temporal propagation patterns

    Science.gov (United States)

    Kreuz, Thomas; Satuvuori, Eero; Pofahl, Martin; Mulansky, Mario

    2017-04-01

    Repetitive spatio-temporal propagation patterns are encountered in fields as wide-ranging as climatology, social communication and network science. In neuroscience, perfectly consistent repetitions of the same global propagation pattern are called a synfire pattern. For any recording of sequences of discrete events (in neuroscience terminology: sets of spike trains) the questions arise how closely it resembles such a synfire pattern and which are the spike trains that lead/follow. Here we address these questions and introduce an algorithm built on two new indicators, termed SPIKE-order and spike train order, that define the synfire indicator value, which allows to sort multiple spike trains from leader to follower and to quantify the consistency of the temporal leader-follower relationships for both the original and the optimized sorting. We demonstrate our new approach using artificially generated datasets before we apply it to analyze the consistency of propagation patterns in two real datasets from neuroscience (giant depolarized potentials in mice slices) and climatology (El Niño sea surface temperature recordings). The new algorithm is distinguished by conceptual and practical simplicity, low computational cost, as well as flexibility and universality.

  20. Comparison of reproductive outcome, including the pattern of loss, between couples with chromosomal abnormalities and those with unexplained repeated miscarriages.

    Science.gov (United States)

    Flynn, Helen; Yan, Junhao; Saravelos, Sotirios H; Li, Tin-Chiu

    2014-01-01

    Chromosomal abnormalities are an important cause of repeated miscarriage. Several studies have discussed the association between chromosomal abnormalities and repeated miscarriage. This study attempts to describe the pattern of miscarriage in this group of women and the eventual pregnancy outcome of couples with chromosomal abnormalities compared with couples with unexplained repeated pregnancy loss. This was a retrospective study involving 795 couples with repeated miscarriages. Out of 795 couples, 28 (3.52%) were found to have a chromosomal abnormality (carrier group). Over half (65.5%) of the chromosomal abnormalities were balanced reciprocal translocations. After referral, this carrier group had a total of 159 pregnancies, leading to 36 live births (22.6%) among 18 couples. The after referral miscarriage rate in the chromosomal anomaly group (55.6%) was significantly (P chromosomal anomaly, the miscarriages were more likely to occur between 6 and 12 weeks' gestation. The encouraging cumulative live birth rate of 64.3% for couples with chromosomal anomaly and repeated miscarriage suggests that further attempts at natural conception are a viable option. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  1. The Temporal Pattern, Flux, and Function of Autophagy in Spinal Cord Injury

    Science.gov (United States)

    Zhou, Kailiang; Sansur, Charles A.; Xu, Huazi; Jia, Xiaofeng

    2017-01-01

    Previous studies have indicated that autophagy plays a critical role in spinal cord injury (SCI), including traumatic spinal cord injury (TSCI) and ischemia-reperfusion spinal cord injury (IRSCI). However, while the understanding of mechanisms underlying autophagy in SCI has progressed, there remain several controversial points: (1) temporal pattern results of autophagic activation after SCI are not consistent across studies; (2) effect of accumulation of autophagosomes due to the blockade or enhancement of autophagic flux is uncertain; (3) overall effect of enhanced autophagy remains undefined, with both beneficial and detrimental outcomes reported in SCI literature. In this review, the temporal pattern of autophagic activation, autophagic flux, autophagic cell death, relationship between autophagy and apoptosis, and pharmacological intervention of autophagy in TSCI (contusion injury, compression injury and hemisection injury) and IRSCI are discussed. Types of SCI and severity appear to contribute to differences in outcomes regarding temporal pattern, flux, and function of autophagy. With future development of specific strategies on autophagy intervention, autophagy may play an important role in improving functional recovery in patients with SCI. PMID:28230791

  2. Application of Genetic Algorithm for the Discovery of Hidden Temporal Patterns in Earthquakes Data

    Directory of Open Access Journals (Sweden)

    Sohair F Higazi

    2013-12-01

    Full Text Available Time Series Data mining (TSDM is one of the most widely used technique that deals with temporal patterns. Genetic algorithm (GA is a predictive TSDM search technique that is used for solving search/optimization problems. GA is based on the principles and mechanisms of natural selections to find the most nearest optimal solution available from a list of solutions. GA relies on a set of important fundamentals, such as chromosome, crossover and mutation. GA is applied to earthquakes data in the year 2003-2004 in the Suez Gulf in Egypt, gathered from the Egyptian National Seismic Network. The study does not aim to building time series models from the point of time, since the analysis neither include the time nor the prediction of when an earth quake will occur, but to determine the possibility of occurrence of a strong magnitude earthquake after specific sequence of previous earthquakes as temporal pattern. The temporal pattern cluster used is a "circle". The objective function used is a function that gives the highest percentage of correct classification. Empirical results show that crossover and mutation probabilities are 0.4 and .01 respectively for both the training and the testing sample. The algorithm yields 96.98% correct classification for the training sample, and 95.35% for the testing sample.

  3. Modulation of heart rate by temporally patterned vagus nerve stimulation in the anesthetized dog.

    Science.gov (United States)

    Yoo, Paul B; Liu, Haoran; Hincapie, Juan G; Ruble, Stephen B; Hamann, Jason J; Grill, Warren M

    2016-02-01

    Despite current knowledge of the myriad physiological effects of vagus nerve stimulation (VNS) in various mammalian species (including humans), the impact of varying stimulation parameters on nerve recruitment and physiological responses is not well understood. We investigated nerve recruitment, cardiovascular responses, and skeletal muscle responses to different temporal patterns of VNS across 39 combinations of stimulation amplitude, frequency, and number of pulses per burst. Anesthetized dogs were implanted with stimulating and recording cuff electrodes around the cervical vagus nerve, whereas laryngeal electromyogram (EMG) and heart rate were recorded. In seven of eight dogs, VNS-evoked bradycardia (defined as ≥10% decrease in heart rate) was achieved by applying stimuli at amplitudes equal to or greater than the threshold for activating slow B-fibers. Temporally patterned VNS (minimum 5 pulses per burst) was sufficient to elicit bradycardia while reducing the concomitant activation of laryngeal muscles by more than 50%. Temporal patterns of VNS can be used to modulate heart rate while minimizing laryngeal motor fiber activation, and this is a novel approach to reduce the side effects produced by VNS.

  4. How can a recurrent neurodynamic predictive coding model cope with fluctuation in temporal patterns? Robotic experiments on imitative interaction.

    Science.gov (United States)

    Ahmadi, Ahmadreza; Tani, Jun

    2017-08-01

    The current paper examines how a recurrent neural network (RNN) model using a dynamic predictive coding scheme can cope with fluctuations in temporal patterns through generalization in learning. The conjecture driving this present inquiry is that a RNN model with multiple timescales (MTRNN) learns by extracting patterns of change from observed temporal patterns, developing an internal dynamic structure such that variance in initial internal states account for modulations in corresponding observed patterns. We trained a MTRNN with low-dimensional temporal patterns, and assessed performance on an imitation task employing these patterns. Analysis reveals that imitating fluctuated patterns consists in inferring optimal internal states by error regression. The model was then tested through humanoid robotic experiments requiring imitative interaction with human subjects. Results show that spontaneous and lively interaction can be achieved as the model successfully copes with fluctuations naturally occurring in human movement patterns. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Timing the provision of a pregnancy decision-aid: temporal patterns of preference for mode of birth during pregnancy.

    Science.gov (United States)

    Shorten, Allison; Shorten, Brett

    2014-10-01

    To help identify the optimal timing for provision of pregnancy decision-aids, this paper examines temporal patterns in women's preference for mode of birth after previous cesarean, prior to a decision-aid intervention. Pregnant women (n=212) with one prior cesarean responded to surveys regarding their preference for elective repeat cesarean delivery (ERCD) or trial of labor (TOL) at 12-18 weeks and again at 28 weeks gestation. Patterns of adherence or change in preference were examined. Women's preferences for birth were not set in early pregnancy. There was evidence of increasing uncertainty about preferred mode of birth during the first two trimesters of pregnancy (McNemar value=4.41, p=0.04), decrease in preference for TOL (McNemar value=3.79, p=0.05) and stability in preference for ERCD (McNemar value=0.31, p=0.58). Adherence to early pregnancy choice was associated with previous birth experience, maternal country of birth, emotional state and hospital site. Women's growing uncertainty about mode of birth prior to 28 weeks indicates potential readiness for a decision-aid earlier in pregnancy. Pregnancy decision-aids affecting mode of birth could be provided early in pregnancy to increase women's opportunity to improve knowledge, clarify personal values and reduce decision uncertainty. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Cheong Y. Ling

    2014-11-01

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

  7. Temporal stability of E. coli concentration patterns in two irrigation ponds in Maryland

    Science.gov (United States)

    Pachepsky, Yakov; Kierzewsky, Rachel; Stocker, Matthew; Mulbry, Walter; Millner, Patricia; Shelton, Daniel

    2017-04-01

    There are about nine million ponds in U.S., and many of them serve as important agricultural surface water source. E. coli concentrations are commonly used to evaluate microbial water quality for irrigation and recreation. Our hypothesis was that temporally stable patterns of E. coli concentrations exist across irrigation ponds, i.e. there are zones where E. coli concentrations are mostly or always lower than the average concentration across a pond for any sampling event, and there are other zones where E. coli concentrations are mostly or always higher than the average concentration across a pond for any sampling event. Two irrigation ponds in Maryland were sampled biweekly in summer of 2016. Samples were taken in 22 locations across one pond and at 34 locations across another pond on grids. Temperature, pH, turbidity, and concentrations of dissolved oxygen, nutrients, chlorophyll a, and generic E. coli were determined. Methods of temporal stability assessment included estimating Vachaud's mean relative differences, computing the Spearman correlation coefficient, and deriving empirical orthogonal functions. All three methods indicated the presence of temporally stable patterns in E. coli concentrations and environmental covariates. The distance from the shore seemed to serve as one of controls. Temporal stability was found for the most of environmental covariates. Smaller mean relative differences of E. coli concentrations corresponded to larger mean relative differences of chlorophyll a. Presence of temporal stability in E. coli concentrations across ponds means that (a) the selection of sampling locations may strongly affect the microbial quality assessment, (b) the microbial quality of water at the pumping intake for irrigation can be affected by the intake location, and (c) one or more locations can be found where E. coli concentrations remain close to the median concentrations across the pond, and can be used to characterize the overall microbial water

  8. Widespread Recurrent Patterns of Rapid Repeat Evolution in the Kinetochore Scaffold KNL1

    NARCIS (Netherlands)

    Tromer, Eelco; Snel, Berend; Kops, Geert J P L

    2015-01-01

    The outer kinetochore protein scaffold KNL1 is essential for error-free chromosome segregation during mitosis and meiosis. A critical feature of KNL1 is an array of repeats containing MELT-like motifs. When phosphorylated, these motifs form docking sites for the BUB1-BUB3 dimer that regulates chromo

  9. Discovery of temporal and disease association patterns in condition-specific hospital utilization rates

    Science.gov (United States)

    Haimovich, Julian S.; Venkatesh, Arjun K.; Coppi, Andreas; Li, Shu-Xia; Krumholz, Harlan M.

    2017-01-01

    Identifying temporal variation in hospitalization rates may provide insights about disease patterns and thereby inform research, policy, and clinical care. However, the majority of medical conditions have not been studied for their potential seasonal variation. The objective of this study was to apply a data-driven approach to characterize temporal variation in condition-specific hospitalizations. Using a dataset of 34 million inpatient discharges gathered from hospitals in New York State from 2008–2011, we grouped all discharges into 263 clinical conditions based on the principal discharge diagnosis using Clinical Classification Software in order to mitigate the limitation that administrative claims data reflect clinical conditions to varying specificity. After applying Seasonal-Trend Decomposition by LOESS, we estimated the periodicity of the seasonal component using spectral analysis and applied harmonic regression to calculate the amplitude and phase of the condition’s seasonal utilization pattern. We also introduced four new indices of temporal variation: mean oscillation width, seasonal coefficient, trend coefficient, and linearity of the trend. Finally, K-means clustering was used to group conditions across these four indices to identify common temporal variation patterns. Of all 263 clinical conditions considered, 164 demonstrated statistically significant seasonality. Notably, we identified conditions for which seasonal variation has not been previously described such as ovarian cancer, tuberculosis, and schizophrenia. Clustering analysis yielded three distinct groups of conditions based on multiple measures of seasonal variation. Our study was limited to New York State and results may not directly apply to other regions with distinct climates and health burden. A substantial proportion of medical conditions, larger than previously described, exhibit seasonal variation in hospital utilization. Moreover, the application of clustering tools yields groups

  10. Spatio-temporal patterns of Barmah Forest virus disease in Queensland, Australia.

    Directory of Open Access Journals (Sweden)

    Suchithra Naish

    Full Text Available BACKGROUND: Barmah Forest virus (BFV disease is a common and wide-spread mosquito-borne disease in Australia. This study investigated the spatio-temporal patterns of BFV disease in Queensland, Australia using geographical information system (GIS tools and geostatistical analysis. METHODS/PRINCIPAL FINDINGS: We calculated the incidence rates and standardised incidence rates of BFV disease. Moran's I statistic was used to assess the spatial autocorrelation of BFV incidences. Spatial dynamics of BFV disease was examined using semi-variogram analysis. Interpolation techniques were applied to visualise and display the spatial distribution of BFV disease in statistical local areas (SLAs throughout Queensland. Mapping of BFV disease by SLAs reveals the presence of substantial spatio-temporal variation over time. Statistically significant differences in BFV incidence rates were identified among age groups (χ(2 = 7587, df = 7327,p<0.01. There was a significant positive spatial autocorrelation of BFV incidence for all four periods, with the Moran's I statistic ranging from 0.1506 to 0.2901 (p<0.01. Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the state. CONCLUSIONS/SIGNIFICANCE: This is the first study to examine spatial and temporal variation in the incidence rates of BFV disease across Queensland using GIS and geostatistics. The BFV transmission varied with age and gender, which may be due to exposure rates or behavioural risk factors. There are differences in the spatio-temporal patterns of BFV disease which may be related to local socio-ecological and environmental factors. These research findings may have implications in the BFV disease control and prevention programs in Queensland.

  11. Inter- vs intra-individual variation and temporal repeatability of escape responses in the coral reef fish Amblyglyphidodon curacao

    Directory of Open Access Journals (Sweden)

    Maïwenn Jornod

    2015-11-01

    Full Text Available Fast-start escape responses are critical behaviours used by fishes during predator-prey encounters and some interactions with hetero- and conspecifics. In experimental studies, escape responses are often measured once per individual and considered representative of maximum performance. However, few studies have compared variability and repeatability in escape performances within and among individuals. Using the tropical damselfish Amblyglyphidodon curacao, we quantified inter- and intra-individual variation in behavioural and kinematic components of escape performance during repeated presentations of a stimulus at 15 min intervals. Individual maximum escape performance was repeatable through time, but there was considerable variation in the magnitude of responses both among and within fish. We found no evidence of habituation or fatigue due to repeated stimulations, suggesting that fish can be stimulated multiple times to ensure that an accurate estimate of maximum escape performance is obtained.

  12. Temporal Patterns in Bacterioplankton Community Composition in Three Reservoirs of Similar Trophic Status in Shenzhen, China

    Directory of Open Access Journals (Sweden)

    Jiancheng Li

    2016-06-01

    Full Text Available The bacterioplankton community composition’s (BCC spatial and temporal variation patterns in three reservoirs (Shiyan, Xikeng, and LuoTian Reservoir of similar trophic status in Bao’an District, Shenzhen (China, were investigated using PCR amplification of the 16S rDNA gene and the denaturing gradient gel electrophoresis (DGGE techniques. Water samples were collected monthly in each reservoir during 12 consecutive months. Distinct differences were detected in band number, pattern, and density of DGGE at different sampling sites and time points. Analysis of the DGGE fingerprints showed that changes in the bacterial community structure mainly varied with seasons, and the patterns of change indicated that seasonal forces might have a more significant impact on the BCC than eutrophic status in the reservoirs, despite the similar Shannon-Weiner index among the three reservoirs. The sequences obtained from excised bands were affiliated with Cyanobacteria, Firmicutes, Bacteriodetes, Acidobacteria, Actinobacteria, Planctomycetes, and Proteobacteria.

  13. Spatio-temporal patterns of forest carbon dioxide exchange based on global eddy covariance measurements

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Spatio-temporal patterns and driving mechanisms of forest carbon dioxide (CO2) exchange are the key issues on terrestrial ecosystem carbon cycles, which are the basis for developing and validating ecosystem carbon cycle models, assessing and predicting the role of forests in global carbon balance. Eddy covariance (EC) technique, an important method for measuring energy and material exchanges between terrestrial ecosystems and the atmosphere, has made a great contribution to understanding CO2 exchanges in the biosphere during the past decade. Here, we synthesized published EC flux measurements at various forest sites in the global network of eddy flux tower sites (FLUXNET) and regional flux networks. Our objective was to explore spatio-temporal patterns and driving factors on forest carbon fluxes, i.e. net ecosystem productivity (NEP), gross primary productivity (GPP) and total ecosystem respiration (TER). Globally, forest NEP exhibited a significant latitudinal pattern jointly controlled by GPP and TER. The NEP decreased in an order of warm temperate forest > cold temperate and tropical rain forests > boreal and subalpine forests. Mean annual temperature (MAT) made a greater contribution to forest carbon fluxes than sum of annual precipitation (SAP). As MAT increased, the GPP increased linearly, whereas the TER increased exponentially, resulting in the NEP decreasing beyond an MAT threshold of 20°C. The GPP, TER and NEP varied substantially when the SAP was less than 1500 mm, but tended to increase with increasing SAP. Temporal dynamics in forest carbon fluxes and determinants depended upon time scales. NEP showed a significant interannual variability mainly driven by climate fluctuations and different responses of the GPP and TER to environmental forcing. In a longer term, forest carbon fluxes had a significant age effect. The ecosystem was a net carbon source right after clearcutting, gradually switched to a net carbon sink when the relative stand age (i

  14. Spatio-temporal patterns of forest carbon dioxide ex change based on global eddy covariance measurements

    Institute of Scientific and Technical Information of China (English)

    WANG XingChang; WANG ChuanKuan; YU GuiRui

    2008-01-01

    Spatio-temporal patterns and driving mechanisms of forest carbon dioxide (CO2) exchange are the key issues on terrestrial ecosystem carbon cycles, which are the basis for developing and validating ecosystem carbon cycle models, assessing and predicting the role of forests in global carbon balance.Eddy covariance (EC) technique, an important method for measuring energy and material exchanges between terrestrial ecosystems and the atmosphere, has made a great contribution to understanding CO2 exchanges in the biosphere during the past decade. Here, we synthesized published EC flux measurements at various forest sites in the global network of eddy flux tower sites (FLUXNET) and regional flux networks. Our objective was to explore spatio-temporal patterns and driving factors on forest carbon fluxes, i.e. net ecosystem productivity (NEP), gross primary productivity (GPP) and total ecosystem respiration (TER). Globally, forest NEP exhibited a significant latitudinal pattern jointly controlled by GPP and TER. The NEP decreased in an order of warm temperate forest > cold temperate and tropical rain forests > boreal and subalpine forests. Mean annual temperature (MAT) made a greater contribution to forest carbon fluxes than sum of annual precipitation (SAP). As MAT increased, the GPP increased linearly, whereas the TER increased exponentially, resulting in the NEP decreasing beyond an MAT threshold of 20℃. The GPP, TER and NEP varied substantially when the SAP was less than 1500 mm, but tended to increase with increasing SAP. Temporal dynamics in forest carbon fluxes and determinants depended upon time scales. NEP showed a significant interannual variability mainly driven by climate fluctuations and different responses of the GPP and TER to environmental forcing. In a longer term, forest carbon fluxes had a significant age effect. The ecosystem was a net carbon source right after clearcutting, gradually switched to a net carbon sink when the relative stand age (i

  15. Decoding of retinal ganglion cell spike trains evoked by temporally patterned electrical stimulation.

    Science.gov (United States)

    Ryu, Sang Baek; Ye, Jang Hee; Goo, Yong Sook; Kim, Chi Hyun; Kim, Kyung Hwan

    2010-08-12

    For successful restoration of vision by retinal prostheses, the neural activity of retinal ganglion cells (RGCs) evoked by electrical stimulation should represent the information of spatiotemporal patterns of visual input. We propose a method to evaluate the effectiveness of stimulation pulse trains so that the crucial temporal information of a visual input is accurately represented in the RGC responses as the amplitudes of pulse trains are modulated according to the light intensity. This was enabled by spike train decoding. The effectiveness of the stimulation was evaluated by the accuracy of decoding pulse amplitude from the RGC spike train, i.e., by the similarity between the original and the decoded pulse amplitude time series. When the parameters of stimulation were suitably determined, the RGC responses were reliably modulated by varying the amplitude of electrical pulses. Accordingly, the temporal pattern of pulse amplitudes could be successfully decoded from multiunit RGC spike trains. The range of pulse amplitude and the pulse rate were critical for accurate representation of input information in RGC responses. These results suggest that pulse amplitude modulation is a feasible means to encode temporal visual information by RGC spike trains and thus to implement stimulus encoding strategies for retinal prostheses.

  16. Microscopic theory of spatial-temporal congested traffic patterns at highway bottlenecks.

    Science.gov (United States)

    Kerner, Boris S; Klenov, Sergey L

    2003-09-01

    A microscopic theory of spatial-temporal congested traffic patterns at highway bottlenecks due to on-ramps, merge bottlenecks (a reduction of highway lanes), and off-ramps is presented. The basic postulate of three-phase traffic theory is used, which claims that homogeneous (in space and time) model solutions (steady states) of synchronized flow cover a two dimensional region in the flow-density plane [B. S. Kerner, Phys. Rev. Lett. 81, 3797 (1998); Trans. Res. Rec. 1678, 160 (1999)]. Phase transitions leading to diverse congested patterns, pattern evolution, and pattern nonlinear features have been found. Diagrams of congested patterns, i.e., regions of the pattern emergence dependent on traffic demand, have been derived. Diverse effects of metastability with respect to the pattern formation have been found. The microscopic theory allows us to explain the main empirical pattern features at on-ramps and off-ramps which have recently been found [B. S. Kerner, Phys. Rev. E 65, 046138 (2002)]. (i) Rather than moving jams, synchronized flow first occurs at bottlenecks if the flow rate is slowly increasing. Wide moving jams can spontaneously occur only in synchronized flow. (ii) General patterns (GP) and synchronized flow patterns (SP) can spontaneously emerge at the bottlenecks. There can be the widening SP (WSP), the moving SP (MSP), and the localized SP. (iii) At on-ramps cases of "weak" and "strong" congestion should be distinguished. In contrast to weak congestion, under strong congestion the flow rate in synchronized flow in GP reaches a limit flow rate, the frequency of the moving jam emergence reaches a maximum, i.e., the GP characteristics under strong congestion do not depend on traffic demand. (iv) At the off-ramp GP with weak congestion occur. (v) A study of the pattern formation on a highway with two bottlenecks shows that diverse expanded patterns can occur, which cover both bottlenecks. SP first emerged at the downstream bottleneck can be caught at the

  17. Identification of neural firing patterns, frequency and temporal coding mechanisms in individual aortic baroreceptors

    Directory of Open Access Journals (Sweden)

    Huaguang eGu

    2015-08-01

    Full Text Available In rabbit depressor nerve fibers, an on-off firing pattern, period-1 firing, and integer multiple firing with quiescent state were observed as the static pressure level was increased. A bursting pattern with bursts at the systolic phase of blood pressure, continuous firing, and bursting with burst at diastolic phase and quiescent state at systolic phase were observed as the mean level of the dynamic blood pressure was increased. For both static and dynamic pressures, the firing frequency of the first two firing patterns increased and of the last firing pattern decreased due to the quiescent state. If the quiescent state is disregarded, the spike frequency becomes an increasing trend. The instantaneous spike frequency of the systolic phase bursting, continuous firing, and diastolic phase bursting can reflect the temporal process of the systolic phase, whole procedure, and diastolic phase of the dynamic blood pressure signal, respectively. With increasing the static current corresponding to pressure level, the deterministic Hodgkin-Huxley (HH model manifests a process from a resting state first to period-1 firing via a subcritical Hopf bifurcation and then to a resting state via a supercritical Hopf bifurcation, and the firing frequency increases. The on-off firing and integer multiple firing were here identified as noise-induced firing patterns near the subcritical and supercritical Hopf bifurcation points, respectively, using the stochastic HH model. The systolic phase bursting and diastolic phase bursting were identified as pressure-induced firings near the subcritical and supercritical Hopf bifurcation points, respectively, using an HH model with a dynamic signal. The firing, spike frequency, and instantaneous spike frequency observed in the experiment were simulated and explained using HH models. The results illustrate the dynamics of different firing patterns and the frequency and temporal coding mechanisms of aortic baroreceptor.

  18. Exploring Spatio-temporal Dynamics of Cellular Automata for Pattern Recognition in Networks

    Science.gov (United States)

    Miranda, Gisele Helena Barboni; Machicao, Jeaneth; Bruno, Odemir Martinez

    2016-11-01

    Network science is an interdisciplinary field which provides an integrative approach for the study of complex systems. In recent years, network modeling has been used for the study of emergent phenomena in many real-world applications. Pattern recognition in networks has been drawing attention to the importance of network characterization, which may lead to understanding the topological properties that are related to the network model. In this paper, the Life-Like Network Automata (LLNA) method is introduced, which was designed for pattern recognition in networks. LLNA uses the network topology as a tessellation of Cellular Automata (CA), whose dynamics produces a spatio-temporal pattern used to extract the feature vector for network characterization. The method was evaluated using synthetic and real-world networks. In the latter, three pattern recognition applications were used: (i) identifying organisms from distinct domains of life through their metabolic networks, (ii) identifying online social networks and (iii) classifying stomata distribution patterns varying according to different lighting conditions. LLNA was compared to structural measurements and surpasses them in real-world applications, achieving improvement in the classification rate as high as 23%, 4% and 7% respectively. Therefore, the proposed method is a good choice for pattern recognition applications using networks and demonstrates potential for general applicability.

  19. Deciphering principles of morphogenesis from temporal and spatial patterns on the integument

    Science.gov (United States)

    Li, Ang; Lai, Yung-Chih; Figueroa, Seth; Yang, Tian; Widelitz, Randall B; Kobielak, Krzysztof; Nie, Qing; Chuong, Cheng Ming

    2015-01-01

    How tissue patterns form in development and regeneration is a fundamental issue remaining to be fully understood. The integument often forms repetitive units in space (periodic patterning) and time (cyclic renewal), such as feathers and hairs. Integument patterns are visible and experimentally manipulatable, helping us reveal pattern formative processes. Variability is seen in regional phenotypic specificities and temporal cycling at different physiological stages. Here we show some cellular / molecular bases revealed by analyzing integument patterns. 1) Localized cellular activity (proliferation, rearrangement, apoptosis, differentiation) transforms prototypic organ primordia into specific shapes. Combinatorial positioning of different localized activity zones generates diverse and complex organ forms. 2) Competitive equilibrium between activators and inhibitors regulates stem cells through cyclic quiescence and activation. Dynamic interactions between stem cells and their adjacent niche regulate regenerative behavior, modulated by multi-layers of macro-environmental factors (dermis, body hormone status and external environment). Genomics studies may reveal how positional information of localized cellular activity is stored. In vivo skin imaging and lineage tracing unveils new insights into stem cell plasticity. Principles of self-assembly obtained from the integumentary organ model can be applied to help restore damaged patterns during regenerative wound healing and for tissue engineering to rebuild tissues. PMID:25858668

  20. Diverse spatio-temporal dynamical patterns of p53 and cell fate decisions

    Science.gov (United States)

    Clairambault, Jean; Eliaš, Ján

    2016-06-01

    The protein p53 as a tumour suppressor protein accumulates in cells in response to DNA damage and transactivates a large variety of genes involved in apoptosis, cell cycle regulation and numerous other processes. Recent biological observations suggest that specific spatio-temporal dynamical patterns of p53 may be associated with specific cellular response, and thus the spatio-temporal heterogeneity of the p53 dynamics contributes to the overall complexity of p53 signalling. Reaction-diffusion equations taking into account spatial representation of the cell and motion of the species inside the cell can be used to model p53 protein network and could be thus of some help to biologists and pharmacologists in anticancer treatment.

  1. Searching electronic health records for temporal patterns in patient histories: a case study with microsoft amalga.

    Science.gov (United States)

    Plaisant, Catherine; Lam, Stanley; Lam, Stanley J; Shneiderman, Ben; Smith, Mark S; Roseman, David; Roseman, David H; Marchand, Greg; Gillam, Michael; Feied, Craig; Handler, Jonathan; Rappaport, Hank

    2008-11-06

    As electronic health records (EHR) become more widespread, they enable clinicians and researchers to pose complex queries that can benefit immediate patient care and deepen understanding of medical treatment and outcomes. However, current query tools make complex temporal queries difficult to pose, and physicians have to rely on computer professionals to specify the queries for them. This paper describes our efforts to develop a novel query tool implemented in a large operational system at the Washington Hospital Center (Microsoft Amalga, formerly known as Azyxxi). We describe our design of the interface to specify temporal patterns and the visual presentation of results, and report on a pilot user study looking for adverse reactions following radiology studies using contrast.

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

    Science.gov (United States)

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

    2016-09-01

    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.

  3. Geographic Variation in Daily Temporal Activity Patterns of a Neotropical Marsupial (Gracilinanus agilis)

    Science.gov (United States)

    Vieira, Emerson M.; de Camargo, Nícholas F.; Colas, Paul F.; Ribeiro, Juliana F.; Cruz-Neto, Ariovaldo P.

    2017-01-01

    The temporal activity of animals is an outcome of both biotic and abiotic factors, which may vary along the geographic range of the species. Therefore, studies conducted with a species in different localities with distinct features could elucidate how animals deal with such factors. In this study, we used live traps equipped with timing devices to investigate the temporal activity patterns of the didelphid Gracilinanus agilis in two dry-woodland areas of the Brazilian savanna (Cerrado). These areas were located about 660 km apart, one in Central Brazil and the other in Southeastern Brazil. We compared such patterns considering both reproductive and non-reproductive periods, and how it varies as a function of temperature on a seasonal basis. In Central Brazil, we found a constant, and temperature-independent activity during the night in both reproductive and non-reproductive periods. On the other hand, in Southeastern Brazil, we detected a constant activity during the reproductive period, but in the non-reproductive period G. agilis presented a peak of activity between two and four hours after sunset. Moreover, in this latter we found a relation between temporal activity and temperature during the autumn and spring. These differences in temporal activity between areas, observed during the non-reproductive period, might be associated with the higher seasonal variability in temperature, and lower mean temperatures in the Southeastern site in comparison to the Central one. In Southeastern Brazil, the decrease in temperature during the non-reproductive season possibly forced G. agilis to be active only at certain hours of the night. However, likely due to the reproductive activities (intensive foraging and searching for mates) this marsupial showed constant, temperature-independent activity during the night in the reproductive period at both sites. PMID:28052077

  4. Temporal Analysis of Activity Patterns of Editors in Collaborative Mapping Project of OpenStreetMap

    CERN Document Server

    Yasseri, Taha; Mashhadi, Afra

    2013-01-01

    In the recent years Wikis have become an attractive platform for social studies of the human behaviour. Containing millions records of edits across the globe, collaborative systems such as Wikipedia have allowed researchers to gain a better understanding of editors participation and their activity patterns. However, contributions made to Geo-wikis_wiki-based collaborative mapping projects_ differ from systems such as Wikipedia in a fundamental way due to spatial dimension of the content that limits the contributors to a set of those who posses local knowledge about a specific area and therefore cross-platform studies and comparisons are required to build a comprehensive image of online open collaboration phenomena. In this work, we study the temporal behavioural pattern of OpenStreetMap editors, a successful example of geo-wiki, for two European capital cities. We categorise different type of temporal patterns and report on the historical trend within a period of 7 years of the project age. We also draw a com...

  5. Spatial and Temporal Patterns of Carbon Storage in Forest Ecosystems on Hainan Island, Southern China

    Science.gov (United States)

    Tang, Xuli; Zhang, Qianmei; Wang, Dong; Yuan, Lianlian; Chen, Xubing

    2014-01-01

    Spatial and temporal patterns of carbon (C) storage in forest ecosystems significantly affect the terrestrial C budget, but such patterns are unclear in the forests in Hainan Province, the largest tropical island in China. Here, we estimated the spatial and temporal patterns of C storage from 1993–2008 in Hainan's forest ecosystems by combining our measured data with four consecutive national forest inventories data. Forest coverage increased from 20.7% in the 1950s to 56.4% in the 2010s. The average C density of 163.7 Mg C/ha in Hainan's forest ecosystems in this study was slightly higher than that of China's mainland forests, but was remarkably lower than that in the tropical forests worldwide. Total forest ecosystem C storage in Hainan increased from 109.51 Tg in 1993 to 279.17 Tg in 2008. Soil C accounted for more than 70% of total forest ecosystem C. The spatial distribution of forest C storage in Hainan was uneven, reflecting differences in land use change and forest management. The potential carbon sequestration of forest ecosystems was 77.3 Tg C if all forested lands were restored to natural tropical forests. To increase the C sequestration potential on Hainan Island, future forest management should focus on the conservation of natural forests, selection of tree species, planting of understory species, and implementation of sustainable practices. PMID:25229628

  6. Temporal changes of spatial soil moisture patterns: controlling factors explained with a multidisciplinary approach

    Science.gov (United States)

    Martini, Edoardo; Wollschläger, Ute; Kögler, Simon; Behrens, Thorsten; Dietrich, Peter; Reinstorf, Frido; Schmidt, Karsten; Weiler, Markus; Werban, Ulrike; Zacharias, Steffen

    2016-04-01

    Characterizing the spatial patterns of soil moisture is critical for hydrological and meteorological models, as soil moisture is a key variable that controls matter and energy fluxes and soil-vegetation-atmosphere exchange processes. Deriving detailed process understanding at the hillslope scale is not trivial, because of the temporal variability of local soil moisture dynamics. Nevertheless, it remains a challenge to provide adequate information on the temporal variability of soil moisture and its controlling factors. Recent advances in wireless sensor technology allow monitoring of soil moisture dynamics with high temporal resolution at varying scales. In addition, mobile geophysical methods such as electromagnetic induction (EMI) have been widely used for mapping soil water content at the field scale with high spatial resolution, as being related to soil apparent electrical conductivity (ECa). The objective of this study was to characterize the spatial and temporal pattern of soil moisture at the hillslope scale and to infer the controlling hydrological processes, integrating well established and innovative sensing techniques, as well as new statistical methods. We combined soil hydrological and pedological expertise with geophysical measurements and methods from digital soil mapping for designing a wireless soil moisture monitoring network. For a hillslope site within the Schäfertal catchment (Central Germany), soil water dynamics were observed during 14 months, and soil ECa was mapped on seven occasions whithin this period of time using an EM38-DD device. Using the Spearman rank correlation coefficient, we described the temporal persistence of a dry and a wet characteristic state of soil moisture as well as the switching mechanisms, inferring the local properties that control the observed spatial patterns and the hydrological processes driving the transitions. Based on this, we evaluated the use of EMI for mapping the spatial pattern of soil moisture under

  7. Tupu methods of spatial-temporal pattern on land use change:a case study in the Yellow River Delta

    Institute of Scientific and Technical Information of China (English)

    YEQinghua; TIANGuoliang; LIUGaohuan; YEJingmin; YAOXin; LIUQingsheng; LOUWeiguo; WUShuguang

    2004-01-01

    Comprehensive study on land-use change of spatial pattern and temporal process is the key component in LUCC study nowadays. Based on the theories and methods of Geo-information Tupu(Carto-methodology in Geo-information, CMGI), integration of spatial pattern and temporal processes of land-use change in the Yellow River Delta (YRD) are studied in the paper, which is supported by ERDAS and ARC/INFO software. The main contents include: (1) concept models of Tupu by spatial-temporal integration on land-use change, whose Tupu unit is synthesized by "Spatial·Attribute·Process" features and composed of relatively homogeneous geographical unit and temporal unit; (2)data sources and handling process, where four stages of spatial features in 1956, 1984, 1991, and 1996are acquired; (3) integration of series of temporal-spatial Tupu, reconstruction series of "Arising" Tupu,spatial-temporal Process Tupu and the spatial temporal Pattern Tupu on land-use change by remap tables; (4) Pattern Tupu analysis on land-use change in YRD during 1956-1996; and (5) spatial difference of the Pattem Tupu analysis by dynamic Tupu units. The various landform units and seven sub-deltas generated by the Yellow River since 1855 are different. The Tupu analysis on land-use in the paper is a promising try on the comprehensive research of "spatial pattern of dynamic process" and "temporal process of spatial pattern" in LUCC research. The Tupu methodology would be a powerful and efficient tool on integrated studies of spatial pattern and temporal process in Geo-science.

  8. The impact of spatial and temporal patterns on multi-cellular behavior

    Science.gov (United States)

    Nikolic, Djordje L.

    What makes a fruit fly a fruit fly? Essentially this question stems from one of the most fascinating problems in biology: how a single cell (fertilized egg) can give rise to a fully grown animal. To be able to answer this question, the importance to how spatial and temporal patterns of gene and protein expression influence the development of an organism must be understood. After all, fruit fly larvae are segmented, while fertilized eggs are not. Pattern formation is fundamental to establishing this organization of the developing embryo with the ultimate goal being the precise arrangements of specialized cells and tissues within each organ in an adult organism. The research presented here showcases the examples of studies that assess the impact spatial and temporal protein patterns have on the behavior of a collection of cells. By introducing new experimental, non-traditional techniques we developed model systems that allowed us to examine the dependence of the strength of adhesion of cells on the protein organization on sub-cellular, micron length scales, and to investigate how epithelial cell sheets coordinate their migration incorporating individual cell locomotion, molecular signal propagation and different boundary conditions. The first part of this dissertation presents a photolithography-based silanization patterning technique that allowed us to homogeneously pattern large areas with high precision. This method is then applied to organizing cell adhesion-promoting proteins on surfaces for the purposes of studying and manipulating cell behavior. We show how the strength of adhesion is dependent on high local density of an adhesive extracellular matrix protein fibronectin. The varied appeal of this technique is exhibited by showing its applicability to pattern stretched DNA, too. The second part of this dissertation focuses on the impact of spatial and temporal propagation of a molecular signal (ERK 1/2 MAPK) in migrating epithelial sheets during wound healing

  9. A polarized digital shearing speckle pattern interferometry system based on temporal wavelet transformation.

    Science.gov (United States)

    Feng, Ziang; Gao, Zhan; Zhang, Xiaoqiong; Wang, Shengjia; Yang, Dong; Yuan, Hao; Qin, Jie

    2015-09-01

    Digital shearing speckle pattern interferometry (DSSPI) has been recognized as a practical tool in testing strain. The DSSPI system which is based on temporal analysis is attractive because of its ability to measure strain dynamically. In this paper, such a DSSPI system with Wollaston prism has been built. The principles and system arrangement are described and the preliminary experimental result of the displacement-derivative test of an aluminum plate is shown with the wavelet transformation method and the Fourier transformation method. The simulations have been conducted with the finite element method. The comparison of the results shows that quantitative measurement of displacement-derivative has been realized.

  10. Assessing hippocampal functional reserve in temporal lobe epilepsy: A multi-voxel pattern analysis of fMRI data

    OpenAIRE

    Bonnici, Heidi M; Sidhu, Meneka; Chadwick, Martin J.; Duncan, John S.; Maguire, Eleanor A.

    2013-01-01

    Summary Assessing the functional reserve of key memory structures in the medial temporal lobes (MTL) of pre-surgical patients with intractable temporal lobe epilepsy (TLE) remains a challenge. Conventional functional MRI (fMRI) memory paradigms have yet to fully convince of their ability to confidently assess the risk of a post-surgical amnesia. An alternative fMRI analysis method, multi-voxel pattern analysis (MVPA), focuses on the patterns of activity across voxels in specific brain regions...

  11. Temporal patterns of happiness and information in a global social network: Hedonometrics and Twitter

    CERN Document Server

    Dodds, Peter Sheridan; Kloumann, Isabel M; Bliss, Catherine A; Danforth, Christopher M

    2011-01-01

    Individual happiness is a fundamental societal metric. Normally measured through self-report, happiness has often been indirectly characterized and overshadowed by more readily quantifiable economic indicators, such as gross domestic product. Here, we use a real-time, remote-sensing, non-invasive, text-based approach---a kind of hedonometer---to uncover collective dynamical patterns of happiness levels expressed by over 50 million users in the online, global social network Twitter. With a data set comprising nearly 2.8 billion expressions involving more than 28 billion words, we explore temporal variations in happiness, as well as information levels, over time scales of hours, days, and months. Among many observations, we find a steady global happiness level, evidence of universal weekly and daily patterns of happiness and information, and that happiness and information levels are generally uncorrelated. We also extract and analyse a collection of happiness and information trends based on keywords, showing th...

  12. Trend and uncertainty in spatial-temporal patterns of hydrological droughts in the Amazon basin

    Science.gov (United States)

    Lopes, A. V.; Chiang, J. C. H.; Thompson, S. A.; Dracup, J. A.

    2016-04-01

    Spatial-temporal patterns of hydrological droughts in the Amazon basin are derived from drought indices computed from existing streamflow data. Principal component analysis and Monte Carlo simulations are employed to account for the uncertainty and overcome the limitations of missing data in streamflow records. Results show that northern and southern subbasins differ in drought trends and in patterns of correlation between drought indices and climate anomalies originating from the Pacific (El Niño-Southern Oscillation) and Atlantic (differences in sea surface temperature across the equator) Oceans. A significant trend toward more intense droughts is found in the southern subbasins, which is highly correlated to tropical Atlantic Ocean sea surface temperature anomalies. That drying trend might have distinct causes in each subbasin and can lead to potential intensification of regional impacts.

  13. Mechanisms for spatio-temporal pattern formation in highway traffic models.

    Science.gov (United States)

    Wilson, R Eddie

    2008-06-13

    A key qualitative requirement for highway traffic models is the ability to replicate a type of traffic jam popularly referred to as a phantom jam, shock wave or stop-and-go wave. Despite over 50 years of modelling, the precise mechanisms for the generation and propagation of stop-and-go waves and the associated spatio-temporal patterns are in dispute. However, the increasing availability of empirical datasets, such as those collected from motorway incident detection and automatic signalling system (MIDAS) inductance loops in the UK or the next-generation simulation trajectory data (NGSIM) project in the USA, means that we can expect to resolve these questions definitively in the next few years. This paper will survey the essence of the competing explanations of highway traffic pattern formation and introduce and analyse a new mechanism, based on dynamical systems theory and bistability, which can help resolve the conflict.

  14. Frequent visitors to psychiatric emergency services: staff attitudes and temporal patterns.

    Science.gov (United States)

    Arfken, Cynthia; Zeman, Lori Lackman; Yeager, Lindsay; Mischel, Edward; Amirsadri, Alireza

    2002-11-01

    Providing quality psychiatric emergency services is becoming more difficult as utilization rates soar, especially by individuals who are frequent visitors. To address this issue, a staff survey and analysis of admission patterns were conducted. Staff were more likely to believe that frequent visitors sought care because they had difficulty accessing alternative services, had basic needs unmet, were substance abusers, wanted inpatient admission, and were noncompliant with treatment plans. The 1999 temporal admission pattern documented that frequent visitors' admissions were higher during the first week of the month and inclement weather. Surprisingly, the infrequent visitors' admissions also were higher during the first week of the month. Together, these findings suggest that, in this urban location, frequent visitors are disadvantaged individuals lacking support and alternative treatment settings who use psychiatric emergency services to meet basic needs.

  15. A framework for the assessment of the spatial and temporal patterns of threatened coastal delphinids

    Science.gov (United States)

    Wang, Jingzhen; Yang, Yingting; Yang, Feng; Li, Yuelin; Li, Lianjie; Lin, Derun; He, Tangtian; Liang, Bo; Zhang, Tao; Lin, Yao; Li, Ping; Liu, Wenhua

    2016-01-01

    The massively accelerated biodiversity loss rate in the Anthropocene calls for an efficient and effective way to identify the spatial and temporal dynamics of endangered species. To this end, we developed a useful identification framework based on a case study of locally endangered Sousa chinensis by combining both LEK (local ecological knowledge) evaluation and regional boat-based survey methods. Our study investigated the basic ecological information of Sousa chinensis in the estuaries of eastern Guangdong that had previously been neglected, which could guide the future study and conservation. Based on the statistical testing of reported spatial and temporal dolphins sighting data from fishermen and the ecological monitoring analyses, including sighting rate, site fidelity and residence time estimations, some of the current Sousa chinensis units are likely to be geographically isolated and critically endangered, which calls for much greater conservation efforts. Given the accelerated population extinction rate and increasing budgetary constraints, our survey pattern can be applied in a timely and economically acceptable manner to the spatial and temporal assessment of other threatened coastal delphinids, particularly when population distributions are on a large scale and traditional sampling methods are difficult to implement.

  16. Gradient analysis of landscape spatial and temporal pattern changes in Beijing metropolitan area

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the urbanization.In order to discover the trend of spatio-temporal changes in Beijing metropolitan area during the past 15 years,several landscape metrics are computed using a moving window along a 96 km long transect across Beijing metropolitan area from west to east.Specially,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly examined.The results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of Beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in Beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.

  17. Exploring the Ecological Coherence between the Spatial and Temporal Patterns of Bacterioplankton in Boreal Lakes

    Directory of Open Access Journals (Sweden)

    Juan Pablo Niño-García

    2017-04-01

    Full Text Available One of the major contemporary challenges in microbial ecology has been to discriminate the reactive core from the random, unreactive components of bacterial communities. In previous work we used the spatial abundance distributions of bacterioplankton across boreal lakes of Québec to group taxa into four distinct categories that reflect either hydrology-mediated dispersal along the aquatic network or environmental selection mechanisms within lakes. Here, we test whether this categorization derived from the spatial distribution of taxa is maintained over time, by analyzing the temporal dynamics of the operational taxonomic units (OTUs within those spatially derived categories along an annual cycle in the oligotrophic lake Croche (Québec, Canada, and assessing the coherence in the patterns of abundance, occurrence, and environmental range of these OTUs over space and time. We report that the temporal dynamics of most taxa within a single lake are largely coherent with those derived from their spatial distribution over large spatial scales, suggesting that these properties must be intrinsic of particular taxa. We also identified a set of rare taxa cataloged as having a random occupancy based on their spatial distribution, but which showed clear seasonality and abundance peaks along the year, yet these comprised a very small fraction of the total rare OTUs. We conclude that the presence of most rare bacterioplankton taxa in boreal lakes is random, since both their temporal and spatial dynamics suggest links to passive downstream transport and persistence in freshwater networks, rather than environmental selection.

  18. Spatio-temporal pattern of vestibular information processing after brief caloric stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Marcelli, Vincenzo [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Esposito, Fabrizio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands)], E-mail: fabrizio.esposito@unina.it; Aragri, Adriana [Department of Neurological Sciences, Second University of Naples, Naples (Italy); Furia, Teresa; Riccardi, Pasquale [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Tosetti, Michela; Biagi, Laura [I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Marciano, Elio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Di Salle, Francesco [Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands); I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Department of Neurosciences, University of Pisa, Pisa (Italy)

    2009-05-15

    Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.

  19. The temporal and spatial patterns of terrestrial net primary productivity in China

    Institute of Scientific and Technical Information of China (English)

    TAOBo; LIKerang; SHAOXuemei; CAOMingkui

    2003-01-01

    In this paper,we use CEVSA,a process-based model,which has been validated on regional and global scales,to explore the temporal and spatial patterns of Net Primary Productivity (NPP) and its responses to interannual Climate fluctuations in China''''''''s terrestrial ecosystems over the period 1981-1998,The estimated results suggest that ,in this study period,the averaged annual total NPP is about 3.09 Gt C/yr-1 and average NPP is about 342 g C/m2,The results also showed that the precipitaion was the key factor determining the spsatial distribution and temporal trends of NPP. Temporally,the total NPP exhibited a slowly increasing trend.In some ENSO years( e.g.1982,1986,1997)NPP decreased clearly compared to the previous year,but the relationship between ENSO and NPP is decreased clearly compared to the previous year,but the relationship between ENSO and NPP is complex due to the integrated effects of monsoons and regional differentiation. Spatially,the relatively high NPP occurred at the middle high latitudes,the low latitudes and the lower appeared at the middle latitudes,On national scale,precipitaion is the key conntro factor on NPP variations and there exists a weak correlation between NP and temperature ,but regional responses are greatly different.

  20. Recognition of music in long-term memory: are melodic and temporal patterns equal partners?

    Science.gov (United States)

    Hébert, S; Peretz, I

    1997-07-01

    The notion that the melody (i.e., pitch structure) of familiar music is more recognizable than its accompanying rhythm (i.e., temporal structure) was examined with the same set of nameable musical excerpts in three experiments. In Experiment 1, the excerpts were modified so as to keep either their original pitch variations, whereas durations were set to isochrony (melodic condition) or their original temporal pattern while played on a single constant pitch (rhythmic condition). The subjects, who were selected without regard to musical training, were found to name more tunes and to rate their feeling of knowing the musical excerpts far higher in the melodic condition than in the rhythmic condition. These results were replicated in Experiment 2, wherein the melodic and rhythmic patterns of the musical excerpts were interchanged to create chimeric mismatched tunes. The difference in saliency of the melodic pattern and the rhythmic pattern also emerged with a music-title-verification task in Experiment 3, hence discarding response selection as the main source of the discrepancy. The lesser effectiveness of rhythmic structure appears to be related to its lesser encoding distinctiveness relative to melodic structure. In general, rhythm was found to be a poor cue for the musical representations that are stored in long-term memory. Nevertheless, in all three experiments, the most effective cue for music identification involved the proper combination of pitches and durations. Therefore, the optimal code of access to long-term memory for music resides in a combination of rhythm and melody, of which the latter would be the most informative.

  1. Spatio-Temporal Patterns of the International Merger and Acquisition Network.

    Science.gov (United States)

    Dueñas, Marco; Mastrandrea, Rossana; Barigozzi, Matteo; Fagiolo, Giorgio

    2017-09-07

    This paper analyses the world web of mergers and acquisitions (M&As) using a complex network approach. We use data of M&As to build a temporal sequence of binary and weighted-directed networks for the period 1995-2010 and 224 countries (nodes) connected according to their M&As flows (links). We study different geographical and temporal aspects of the international M&A network (IMAN), building sequences of filtered sub-networks whose links belong to specific intervals of distance or time. Given that M&As and trade are complementary ways of reaching foreign markets, we perform our analysis using statistics employed for the study of the international trade network (ITN), highlighting the similarities and differences between the ITN and the IMAN. In contrast to the ITN, the IMAN is a low density network characterized by a persistent giant component with many external nodes and low reciprocity. Clustering patterns are very heterogeneous and dynamic. High-income economies are the main acquirers and are characterized by high connectivity, implying that most countries are targets of a few acquirers. Like in the ITN, geographical distance strongly impacts the structure of the IMAN: link-weights and node degrees have a non-linear relation with distance, and an assortative pattern is present at short distances.

  2. Optimization of Classification Strategies of Acetowhite Temporal Patterns towards Improving Diagnostic Performance of Colposcopy

    Directory of Open Access Journals (Sweden)

    Karina Gutiérrez-Fragoso

    2017-01-01

    Full Text Available Efforts have been being made to improve the diagnostic performance of colposcopy, trying to help better diagnose cervical cancer, particularly in developing countries. However, improvements in a number of areas are still necessary, such as the time it takes to process the full digital image of the cervix, the performance of the computing systems used to identify different kinds of tissues, and biopsy sampling. In this paper, we explore three different, well-known automatic classification methods (k-Nearest Neighbors, Naïve Bayes, and C4.5, in addition to different data models that take full advantage of this information and improve the diagnostic performance of colposcopy based on acetowhite temporal patterns. Based on the ROC and PRC area scores, the k-Nearest Neighbors and discrete PLA representation performed better than other methods. The values of sensitivity, specificity, and accuracy reached using this method were 60% (95% CI 50–70, 79% (95% CI 71–86, and 70% (95% CI 60–80, respectively. The acetowhitening phenomenon is not exclusive to high-grade lesions, and we have found acetowhite temporal patterns of epithelial changes that are not precancerous lesions but that are similar to positive ones. These findings need to be considered when developing more robust computing systems in the future.

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

    Directory of Open Access Journals (Sweden)

    Kulldorff Martin

    2007-04-01

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

  4. Hyperpigmentation in North Sea dab Limanda limanda. I. Spatial and temporal patterns and host effects.

    Science.gov (United States)

    Grütjen, F; Lang, T; Feist, S; Bruno, D; Noguera, P; Wosniok, W

    2013-03-13

    Hyperpigmentation is a term describing a specific pigment anomaly affecting common dab Limanda limanda in the North Sea and, less frequently, in adjacent areas, e.g. the English Channel, Irish and Celtic Seas, western Baltic Sea and Icelandic waters. Other North Sea flatfish species are also affected, but at a markedly lower prevalence. The condition is characterised by the occurrence of varying degrees of green to black patchy pigment spots in the skin of the upper (ocular) body side and pearly-white pigment spots in the skin of the lower (abocular) body side. In the course of fish disease monitoring programmes carried out by Germany and the UK (England and Scotland), a pronounced spatial pattern of hyperpigmentation has been detected in the North Sea. An increase in prevalence has been recorded in almost all North Sea areas studied in the past 2 decades. The prevalence recorded in hot spot areas of the condition increased from 5 to >40% between 1988 and 2009. Analysis of the German data indicates that the prevalence and intensity (degree of discolouration) of hyperpigmentation increase with size and age, indicating a temporal progression of the condition with size and age. Intense hyperpigmentation is associated with increased growth (length) and decreased condition factor. Potential causes of the condition (UV-B radiation nutrition, water temperature increase, demographic changes) and, in particular, of the spatial/temporal patterns recorded as well as the relationship to host-specific factors (sex, age, length, growth, condition factor) are discussed.

  5. Local Temporal Correlation Common Spatial Patterns for Single Trial EEG Classification during Motor Imagery

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    Rui Zhang

    2013-01-01

    Full Text Available Common spatial pattern (CSP is one of the most popular and effective feature extraction methods for motor imagery-based brain-computer interface (BCI, but the inherent drawback of CSP is that the estimation of the covariance matrices is sensitive to noise. In this work, local temporal correlation (LTC information was introduced to further improve the covariance matrices estimation (LTCCSP. Compared to the Euclidean distance used in a previous CSP variant named local temporal CSP (LTCSP, the correlation may be a more reasonable metric to measure the similarity of activated spatial patterns existing in motor imagery period. Numerical comparisons among CSP, LTCSP, and LTCCSP were quantitatively conducted on the simulated datasets by adding outliers to Dataset IVa of BCI Competition III and Dataset IIa of BCI Competition IV, respectively. Results showed that LTCCSP achieves the highest average classification accuracies in all the outliers occurrence frequencies. The application of the three methods to the EEG dataset recorded in our laboratory also demonstrated that LTCCSP achieves the highest average accuracy. The above results consistently indicate that LTCCSP would be a promising method for practical motor imagery BCI application.

  6. Temporal patterns of genetic and phenotypic variation in the epidemiologically important drone fly, Eristalis tenax.

    Science.gov (United States)

    Francuski, Lj; Matić, I; Ludoški, J; Milankov, V

    2011-06-01

    Eristalis tenax L. (Diptera: Syrphidae) is commonly known as the drone fly (adult) or rat-tailed maggot (immature). Both adults and immature stages are identified as potential mechanical vectors of mycobacterial pathogens, and early-stage maggots cause accidental myiasis. We compared four samples from Mount Fruška Gora, Serbia, with the aim of obtaining insights into the temporal variations and sexual dimorphism in the species. This integrative approach was based on allozyme loci, morphometric wing parameters (shape and size) and abdominal colour patterns. Consistent sexual dimorphism was observed, indicating that male specimens had lighter abdomens and smaller and narrower wings than females. The distribution of genetic diversity at polymorphic loci indicated genetic divergence among collection dates. Landmark-based geometric morphometrics revealed, contrary to the lack of divergence in wing size, significant wing shape variation throughout the year. In addition, temporal changes in the frequencies of the abdominal patterns observed are likely to relate to the biology of the species and ecological factors in the locality. Hence, the present study expands our knowledge of the genetic diversity and phenotypic plasticity of E. tenax. The quantification of such variability represents a step towards the evaluation of the adaptive potential of this species of medical and epidemiological importance.

  7. Reproductive behaviour of Crocidosema (=Epinotia) aporema (Walsingham) (Lepidoptera: Tortricidae): temporal pattern of female calling and mating

    Energy Technology Data Exchange (ETDEWEB)

    Altesor, Paula; Arcia, Maria P.; Rossini, Carmen; Gonzalez, Andres, E-mail: paltesor@fq.edu.u, E-mail: mparcia@fq.edu.u, E-mail: crossini@fq.edu.u, E-mail: agonzal@fq.edu.u [Universidad de la Republica, Montevideo (Uruguay). Fac. de Quimica. Lab. de Ecologia Quimica; Horas, Vanusa R; Zarbin, Paulo H.G., E-mail: vanusa@quimica.ufpr.b, E-mail: pzarbin@quimica.ufpr.b [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Semioquimicos

    2010-06-15

    Crocidosema aporema (Walsingham) is a major pest of legumes in the southern cone of Latin America. The mating behaviour of two allopatric populations (Uruguay and Brazil) of C. aporema kept in captivity was studied by observing the posture of calling females, the temporal pattern of pheromone emission and mating, and the response of males to calling females in olfactometer tests. Female calling and mating was observed during the scotophase, from the fi rst to the seventh night after adult emergence. Male response was evaluated at night using a single calling female in a Y-shaped olfactometer. Females adopted a characteristic calling posture, extruding the pheromone gland from the tip of the abdomen. Most females started calling during the second scotophase, and all females called from the third, between the fifth and seventh hours after the onset of the scotophase. Most of the couples mated once throughout the experiment, between the third and sixth night and during the middle of the dark phase. Males preferentially chose the female arm in olfactometer tests, considering both the fi rst arm chosen and the number of visits during the observation period. Our results describe for the fi rst time the temporal pattern associated to the reproductive behaviour of C. aporema. We also provide evidence that this tortricid is monoandrous, and that pheromones are used in intersexual communication for mate finding. Our data will be used to optimize the collection of female sex pheromones for chemical characterization in order to develop a monitoring tool for this pest. (author)

  8. Temporal patterns of human and canine Giardia infection in the United States: 2003-2009.

    Science.gov (United States)

    Mohamed, Ahmed S; Levine, Michael; Camp, Joseph W; Lund, Elisabeth; Yoder, Jonathan S; Glickman, Larry T; Moore, George E

    2014-02-01

    Giardia protozoa have been suspected to be of zoonotic transmission, including transmission from companion animals such as pet dogs to humans. Patterns of infection have been previously described for dogs and humans, but such investigations have used different time periods and locations for these two species. Our objective was to describe and compare the overall trend and seasonality of Giardia species infection among dogs and humans in the United States from 2003 through 2009 in an ecological study using public health surveillance data and medical records of pet dogs visiting a large nationwide private veterinary hospital. Canine data were obtained from all dogs visiting Banfield hospitals in the United States with fecal test results for Giardia species, from January 2003 through December 2009. Incidence data of human cases from the same time period were obtained from the CDC. Descriptive time plots, a seasonal trend decomposition (STL) procedure, and seasonal autoregressive moving-average (SARIMA) models were used to assess the temporal characteristics of Giardia infection in the two species. Canine incidence showed a gradual decline from 2003 to 2009 with no significant/distinct regular seasonal component. By contrast, human incidence showed a stable annual rate with a significant regular seasonal cycle, peaking in August and September. Different temporal patterns in human and canine Giardia cases observed in this study suggest that the epidemiological disease processes underlying both series might be different, and Giardia transmission between humans and their companion dogs seems uncommon.

  9. Fish and phytoplankton exhibit contrasting temporal species abundance patterns in a dynamic north temperate lake.

    Directory of Open Access Journals (Sweden)

    Gretchen J A Hansen

    Full Text Available Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of "core" (common occurrence and high abundance and "occasional" (rare occurrence and low abundance species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions.

  10. Spatio-temporal patterns of key exploited marine species in the Northwestern Mediterranean Sea.

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    Marie Morfin

    Full Text Available This study analyzes the temporal variability/stability of the spatial distributions of key exploited species in the Gulf of Lions (Northwestern Mediterranean Sea. To do so, we analyzed data from the MEDITS bottom-trawl scientific surveys from 1994 to 2010 at 66 fixed stations and selected 12 key exploited species. We proposed a geostatistical approach to handle zero-inflated and non-stationary distributions and to test for the temporal stability of the spatial structures. Empirical Orthogonal Functions and other descriptors were then applied to investigate the temporal persistence and the characteristics of the spatial patterns. The spatial structure of the distribution (i.e. the pattern of spatial autocorrelation of the 12 key species studied remained highly stable over the time period sampled. The spatial distributions of all species obtained through kriging also appeared to be stable over time, while each species displayed a specific spatial distribution. Furthermore, adults were generally more densely concentrated than juveniles and occupied areas included in the distribution of juveniles. Despite the strong persistence of spatial distributions, we also observed that the area occupied by each species was correlated to its abundance: the more abundant the species, the larger the occupation area. Such a result tends to support MacCall's basin theory, according to which density-dependence responses would drive the expansion of those 12 key species in the Gulf of Lions. Further analyses showed that these species never saturated their habitats, suggesting that they are below their carrying capacity; an assumption in agreement with the overexploitation of several of these species. Finally, the stability of their spatial distributions over time and their potential ability to diffuse outside their main habitats give support to Marine Protected Areas as a potential pertinent management tool.

  11. The chronotron: a neuron that learns to fire temporally precise spike patterns.

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    Răzvan V Florian

    Full Text Available In many cases, neurons process information carried by the precise timings of spikes. Here we show how neurons can learn to generate specific temporally precise output spikes in response to input patterns of spikes having precise timings, thus processing and memorizing information that is entirely temporally coded, both as input and as output. We introduce two new supervised learning rules for spiking neurons with temporal coding of information (chronotrons, one that provides high memory capacity (E-learning, and one that has a higher biological plausibility (I-learning. With I-learning, the neuron learns to fire the target spike trains through synaptic changes that are proportional to the synaptic currents at the timings of real and target output spikes. We study these learning rules in computer simulations where we train integrate-and-fire neurons. Both learning rules allow neurons to fire at the desired timings, with sub-millisecond precision. We show how chronotrons can learn to classify their inputs, by firing identical, temporally precise spike trains for different inputs belonging to the same class. When the input is noisy, the classification also leads to noise reduction. We compute lower bounds for the memory capacity of chronotrons and explore the influence of various parameters on chronotrons' performance. The chronotrons can model neurons that encode information in the time of the first spike relative to the onset of salient stimuli or neurons in oscillatory networks that encode information in the phases of spikes relative to the background oscillation. Our results show that firing one spike per cycle optimizes memory capacity in neurons encoding information in the phase of firing relative to a background rhythm.

  12. Timescales of multineuronal activity patterns reflect temporal structure of visual stimuli.

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    Ovidiu F Jurjuţ

    Full Text Available The investigation of distributed coding across multiple neurons in the cortex remains to this date a challenge. Our current understanding of collective encoding of information and the relevant timescales is still limited. Most results are restricted to disparate timescales, focused on either very fast, e.g., spike-synchrony, or slow timescales, e.g., firing rate. Here, we investigated systematically multineuronal activity patterns evolving on different timescales, spanning the whole range from spike-synchrony to mean firing rate. Using multi-electrode recordings from cat visual cortex, we show that cortical responses can be described as trajectories in a high-dimensional pattern space. Patterns evolve on a continuum of coexisting timescales that strongly relate to the temporal properties of stimuli. Timescales consistent with the time constants of neuronal membranes and fast synaptic transmission (5-20 ms play a particularly salient role in encoding a large amount of stimulus-related information. Thus, to faithfully encode the properties of visual stimuli the brain engages multiple neurons into activity patterns evolving on multiple timescales.

  13. Himalayan glaciers: understanding contrasting patterns of glacier behavior using multi-temporal satellite imagery

    Science.gov (United States)

    Racoviteanu, A.

    2014-12-01

    High rates of glacier retreat for the last decades are often reported, and believed to be induced by 20th century climate changes. However, regional glacier fluctuations are complex, and depend on a combination of climate and local topography. Furthermore, in ares such as the Hindu-Kush Himalaya, there are concerns about warming, decreasing monsoon precipitation and their impact on local glacier regimes. Currently, the challenge is in understanding the magnitude of feedbacks between large-scale climate forcing and small-scale glacier behavior. Spatio-temporal patterns of glacier distribution are still llimited in some areas of the high Hindu-Kush Himalaya, but multi-temporal satellite imagery has helped fill spatial and temporal gaps in regional glacier parameters in the last decade. Here I present a synopsis of the behavior of glaciers across the Himalaya, following a west to east gradient. In particular, I focus on spatial patterns of glacier parameters in the eastern Himalaya, which I investigate at multi-spatial scales using remote sensing data from declassified Corona, ASTER, Landsat ETM+, Quickbird and Worldview2 sensors. I also present the use of high-resolution imagery, including texture and thermal analysis for mapping glacier features at small scale, which are particularly useful in understanding surface trends of debris-covered glaciers, which are prevalent in the Himalaya. I compare and contrast spatial patterns of glacier area and élévation changes in the monsoon-influenced eastern Himalaya (the Everest region in the Nepal Himalaya and Sikkim in the Indian Himalaya) with other observations from the dry western Indian Himalaya (Ladakh and Lahul-Spiti), both field measurements and remote sensing-based. In the eastern Himalaya, results point to glacier area change of -0.24 % ± 0.08% per year from the 1960's to the 2006's, with a higher rate of retreat in the last decade (-0.43% /yr). Debris-covered glacier tongues show thinning trends of -30.8 m± 39 m

  14. Detecting the community structure and activity patterns of temporal networks: a non-negative tensor factorization approach

    CERN Document Server

    Gauvin, Laetitia; Cattuto, Ciro

    2014-01-01

    The increasing availability of temporal network data is calling for more research on extracting and characterizing mesoscopic structures in temporal networks and on relating such structure to specific functions or properties of the system. An outstanding challenge is the extension of the results achieved for static networks to time-varying networks, where the topological structure of the system and the temporal activity patterns of its components are intertwined. Here we investigate the use of a latent factor decomposition technique, non-negative tensor factorization, to extract the community-activity structure of temporal networks. The method is intrinsically temporal and allows to simultaneously identify communities and to track their activity over time. We represent the time-varying adjacency matrix of a temporal network as a three-way tensor and approximate this tensor as a sum of terms that can be interpreted as communities of nodes with an associated activity time series. We summarize known computationa...

  15. Spatial and temporal exposure patterns in non-target small mammals during brodifacoum rat control.

    Science.gov (United States)

    Geduhn, Anke; Esther, Alexandra; Schenke, Detlef; Mattes, Hermann; Jacob, Jens

    2014-10-15

    Worldwide pest rodents on livestock farms are often regulated using anticoagulant rodenticides (ARs). Second generation ARs in particular can cause poisoning in non-target species due to their high toxicity and persistence. However, research on exposure of small mammals is rare. We systematically investigated spatial and temporal exposure patterns of non-target small mammals in a large-scale replicated study. Small mammals were trapped at different distances to bait stations on ten farms before, during and after brodifacoum (BR) bait application, and liver samples of 1178 non-target small mammals were analyzed for residues of eight ARs using liquid chromatography coupled with tandem mass spectrometry. BR residues were present in 23% out of 742 samples collected during and after baiting. We found clear spatial and temporal exposure patterns. High BR residue concentrations mainly occurred within 15m from bait stations. Occurrence and concentrations of residues significantly decreased with increasing distance. This pattern was found in almost all investigated taxa. After baiting, significantly more individuals contained residues than during baiting but concentrations were considerably lower. Residue occurrence and concentrations differed significantly among taxa, with the highest maximal residue concentrations in Apodemus species, which are protected in Germany. Although Sorex species are known to be insectivorous we regularly found residues in this genus. Residues of active agents other than brodifacoum were rare in all samples. The confirmation of substantial primary exposure in non-target small mammals close to the baiting area indicates considerable risk of secondary poisoning of predators, a pathway that was possibly underestimated until now. Our results will help to develop risk mitigation strategies to reduce risk for non-target small mammals, as well as their predators, in relation to biocidal AR usage.

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

    Science.gov (United States)

    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 (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).

  17. Temporal patterns and behavioral characteristics of aggregation formation and spawning in the Bermuda chub ( Kyphosus sectatrix)

    Science.gov (United States)

    Nemeth, Richard S.; Kadison, Elizabeth

    2013-12-01

    Reef fish spawning aggregations are important life history events that occur at specific times and locations and represent the primary mode of reproduction for many species. This paper provides detailed descriptions of aggregation formation and mass spawning of the Bermuda chub ( Kyphosus sectatrix). Spawning coloration and gamete release of K. sectatrix were observed and filmed at the Grammanik Bank, a deep spawning aggregation site used by many different species located on the southern edge of the Puerto Rican shelf 10 km south of St. Thomas, US Virgin Islands. Underwater visual surveys using technical Nitrox and closed circuit re-breathers were conducted from December 2002 to March 2013 and documented spatial and temporal patterns of movement and aggregation formation along 1.5 km of mesophotic reef. The largest aggregations of K. sectatrix (>200 fish) were observed on the Grammanik Bank January to March from 0 to 11 d after the full moon with peak abundance from 60 to 80 d after the winter solstice across all survey years. Aggregation formation of K. sectatrix coincided with the spawning season of Nassau ( Epinephelus striatus) and yellowfin ( Mycteroperca venenosa) groupers. These spatial and temporal patterns of aggregation formation and spawning suggest that K. sectatrix, an herbivore, may also be a transient aggregating species. On several occasions, chubs were observed both pair spawning and mass spawning. Color patterns and behaviors associated with aggregation and spawning are described and compared to spawning characteristics observed in other species, many of which are similar but others that appear unique to K. sectatrix. This represents the first report of a kyphosid species aggregating to spawn and illuminates a portion of the poorly understood life history of the Bermuda chub.

  18. Spatial and Temporal Microbial Patterns in a Tropical Macrotidal Estuary Subject to Urbanization

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    Mirjam Kaestli

    2017-07-01

    Full Text Available Darwin Harbour in northern Australia is an estuary in the wet-dry tropics subject to increasing urbanization with localized water quality degradation due to increased nutrient loads from urban runoff and treated sewage effluent. Tropical estuaries are poorly studied compared to temperate systems and little is known about the microbial community-level response to nutrients. We aimed to examine the spatial and temporal patterns of the bacterial community and its association with abiotic factors. Since Darwin Harbour is macrotidal with strong seasonal patterns and mixing, we sought to determine if a human impact signal was discernible in the microbiota despite the strong hydrodynamic forces. Adopting a single impact–double reference design, we investigated the bacterial community using next-generation sequencing of the 16S rRNA gene from water and sediment from reference creeks and creeks affected by effluent and urban runoff. Samples were collected over two years during neap and spring tides, in the dry and wet seasons. Temporal drivers, namely seasons and tides had the strongest relationship to the water microbiota, reflecting the macrotidal nature of the estuary and its location in the wet-dry tropics. The neap-tide water microbiota provided the clearest spatial resolution while the sediment microbiota reflected current and past water conditions. Differences in patterns of the microbiota between different parts of the harbor reflected the harbor's complex hydrodynamics and bathymetry. Despite these variations, a microbial signature was discernible relating to specific effluent sources and urban runoff, and the composite of nutrient levels accounted for the major part of the explained variation in the microbiota followed by salinity. Our results confirm an overall good water quality but they also reflect the extent of some hypereutrophic areas. Our results show that the microbiota is a sensitive indicator to assess ecosystem health even in this

  19. Self-Organization of Spatio-Temporal Hierarchy via Learning of Dynamic Visual Image Patterns on Action Sequences.

    Science.gov (United States)

    Jung, Minju; Hwang, Jungsik; Tani, Jun

    2015-01-01

    It is well known that the visual cortex efficiently processes high-dimensional spatial information by using a hierarchical structure. Recently, computational models that were inspired by the spatial hierarchy of the visual cortex have shown remarkable performance in image recognition. Up to now, however, most biological and computational modeling studies have mainly focused on the spatial domain and do not discuss temporal domain processing of the visual cortex. Several studies on the visual cortex and other brain areas associated with motor control support that the brain also uses its hierarchical structure as a processing mechanism for temporal information. Based on the success of previous computational models using spatial hierarchy and temporal hierarchy observed in the brain, the current report introduces a novel neural network model for the recognition of dynamic visual image patterns based solely on the learning of exemplars. This model is characterized by the application of both spatial and temporal constraints on local neural activities, resulting in the self-organization of a spatio-temporal hierarchy necessary for the recognition of complex dynamic visual image patterns. The evaluation with the Weizmann dataset in recognition of a set of prototypical human movement patterns showed that the proposed model is significantly robust in recognizing dynamically occluded visual patterns compared to other baseline models. Furthermore, an evaluation test for the recognition of concatenated sequences of those prototypical movement patterns indicated that the model is endowed with a remarkable capability for the contextual recognition of long-range dynamic visual image patterns.

  20. Diurnal Changes of Heart Rate and Sympathovagal Activity for Temporal Patterns of Transient Ischemic Episodes in 24-Hour Electrocardiograms

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    F. Jager

    2007-01-01

    Full Text Available We test the hypothesis that different temporal patterns of transient ST segment changes compatible with ischemia (ischemic episodes are a result of different physiologic mechanisms responsible for ischemia. We tested the hypothesis using records of the Long-Term ST Database. Each record was divided into three intervals of records: morning, day, and night intervals; and was inserted into one of three sets according to the temporal pattern of ischemia: salvo, periodic, and sporadic pattern. We derived time- and frequency-domain parameters of the heart rate time series in selected intervals in the neighborhood of ischemic episodes. We used the adaptive autoregressive method with a recursive least-square algorithm for consistent spectral tracking of heart rate time series and to study frequency-domain sympathovagal behavior during ischemia. The results support the hypothesis that there are at least two distinct populations, which differ according to mechanisms and temporal patterns of ischemia.

  1. Patterns of Canopy and Surface Layer Consumption in a Boreal Forest Fire from Repeat Airborne Lidar

    Science.gov (United States)

    Alonzo, Michael; Morton, Douglas C.; Cook, Bruce D.; Andersen, Hans-Erik; Babcock, Chad; Pattison, Robert

    2017-01-01

    Fire in the boreal region is the dominant agent of forest disturbance with direct impacts on ecosystem structure, carbon cycling, and global climate. Global and biome-scale impacts are mediated by burn severity, measured as loss of forest canopy and consumption of the soil organic layer. To date, knowledge of the spatial variability in burn severity has been limited by sparse field sampling and moderate resolution satellite data. Here, we used pre- and post-fire airborne lidar data to directly estimate changes in canopy vertical structure and surface elevation for a 2005 boreal forest fire on Alaskas Kenai Peninsula. We found that both canopy and surface losses were strongly linked to pre-fire species composition and exhibited important fine-scale spatial variability at sub-30m resolution. The fractional reduction in canopy volume ranged from 0.61 in lowland black spruce stands to 0.27 in mixed white spruce and broad leaf forest. Residual structure largely reflects standing dead trees, highlighting the influence of pre-fire forest structure on delayed carbon losses from above ground biomass, post-fire albedo, and variability in understory light environments. Median loss of surface elevation was highest in lowland black spruce stands (0.18 m) but much lower in mixed stands (0.02 m), consistent with differences in pre-fire organic layer accumulation. Spatially continuous depth-of-burn estimates from repeat lidar measurements provide novel information to constrain carbon emissions from the surface organic layer and may inform related research on post-fire successional trajectories. Spectral measures of burn severity from Landsat were correlated with canopy (r = 0.76) and surface (r = -0.71) removal in black spruce stands but captured less of the spatial variability in fire effects for mixed stands (canopy r = 0.56, surface r = -0.26), underscoring the difficulty in capturing fire effects in heterogeneous boreal forest landscapes using proxy measures of burn severity

  2. Relationship between Musical Characteristics and Temporal Breathing Pattern in Piano Performance.

    Science.gov (United States)

    Sakaguchi, Yutaka; Aiba, Eriko

    2016-01-01

    Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale, Hanon's exercise, J. S. Bach's Invention, Mozart's Sonatas, and Debussy's Clair de lune), was monitored by capnography. The relationship between breathing and musical characteristics was analyzed. Five major results were obtained. (1) Mean breath interval was shortened for excerpts in faster tempi. (2) Fluctuation of breath intervals was reduced for the pieces for finger exercise and those in faster tempi. Pianists showing large within-trial fluctuation also exhibited large inter-excerpt difference. (3) Inter-trial consistency of the breath patterns depended on the excerpts. Consistency was generally reduced for the excerpts that could be performed mechanically (i.e., pieces for finger exercise), but interestingly, one third of the participant showed consistent patterns for the simple scale, correlated with the ascending/descending sequences. (4) Pianists tended to exhale just after the music onsets, inhale at the rests, and inhibit inhale during the slur parts. There was correlation between breathing pattern and two-voice polyphonic structure for several participants. (5) Respiratory patterns were notably different among the pianists. Every pianist showed his or her own characteristic features commonly for various musical works. These findings suggest that breathing in piano performance depends not only on musical parameters and organization written in the score but also some pianist-dependent factors which might be ingrained to individual pianists.

  3. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns.

    Science.gov (United States)

    Si, Yali; Skidmore, Andrew K; Wang, Tiejun; de Boer, Willem F; Debba, Pravesh; Toxopeus, Albert G; Li, Lin; Prins, Herbert H T

    2009-11-01

    The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March). In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  4. Relationship between Musical Characteristics and Temporal Breathing Pattern in Piano Performance

    Science.gov (United States)

    Sakaguchi, Yutaka; Aiba, Eriko

    2016-01-01

    Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale, Hanon's exercise, J. S. Bach's Invention, Mozart's Sonatas, and Debussy's Clair de lune), was monitored by capnography. The relationship between breathing and musical characteristics was analyzed. Five major results were obtained. (1) Mean breath interval was shortened for excerpts in faster tempi. (2) Fluctuation of breath intervals was reduced for the pieces for finger exercise and those in faster tempi. Pianists showing large within-trial fluctuation also exhibited large inter-excerpt difference. (3) Inter-trial consistency of the breath patterns depended on the excerpts. Consistency was generally reduced for the excerpts that could be performed mechanically (i.e., pieces for finger exercise), but interestingly, one third of the participant showed consistent patterns for the simple scale, correlated with the ascending/descending sequences. (4) Pianists tended to exhale just after the music onsets, inhale at the rests, and inhibit inhale during the slur parts. There was correlation between breathing pattern and two-voice polyphonic structure for several participants. (5) Respiratory patterns were notably different among the pianists. Every pianist showed his or her own characteristic features commonly for various musical works. These findings suggest that breathing in piano performance depends not only on musical parameters and organization written in the score but also some pianist-dependent factors which might be ingrained to individual pianists. PMID:27516736

  5. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns

    Directory of Open Access Journals (Sweden)

    Yali Si

    2009-11-01

    Full Text Available The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March. In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  6. Temporal patterns and geographic heterogeneity of Zika virus (ZIKV) outbreaks in French Polynesia and Central America

    Science.gov (United States)

    2017-01-01

    Background Zika virus (ZIKV) transmission has been reported in 67 countries/territories in the Oceania region and the Americas since 2015, prompting the World Health Organization (WHO) to declare ZIKV as a Public Health Emergency of International Concern in February 2016, due to its strong association with medical complications such as microcephaly and Guillain–Barré Syndrome (GBS). However, a substantial gap in knowledge still exists regarding differing temporal pattern and potential of transmission of ZIKV in different regions of the world. Methods We use a phenomenological model to ascertain the temporal patterns and transmission potential of ZIKV in various countries/territories, by fitting the model to Zika case data from Yap Island and French Polynesia in the Oceania region and 11 countries/territories with confirmed case data, namely, Colombia, Ecuador, French Guiana, Guadeloupe, Guatemala, Mexico, Nicaragua, Panama, Puerto Rico, Saint Martin, and Suriname, to pinpoint the waves of infections in each country/territory and to estimate the respective basic reproduction number R0. Results Six of these time series datasets resulted in statistically significant model fit of at least one wave of reported cases, namely that of French Polynesia, Colombia, Puerto Rico, Guatemala, Suriname and Saint Martin. However, only Colombia and Guatemala exhibited two waves of cases while the others had only one wave. Temporal patterns of the second wave in Colombia and the single wave in Suriname are very similar, with the respective turning points separated by merely a week. Moreover, the mean estimates of R0 for Colombia, Guatemala and Suriname, all land-based populations, range between 1.05 and 1.75, while the corresponding mean estimates for R0 of island populations in French Polynesia, Puerto Rico and Saint Martin are significantly lower with a range of 5.70–6.89. We also fit the Richards model to Zika case data from six main archipelagos in French Polynesia

  7. Temporal Pattern Recognition: A Network Architecture For Multi-Sensor Fusion

    Science.gov (United States)

    Priebe, C. E.; Marchette, D. J.

    1989-03-01

    A self-organizing network architecture for the learning and recognition of temporal patterns is proposed. This multi-layered architecture has as its focal point a layer of multi-dimensional Gaussian classification nodes, and the learning scheme employed is based on standard statistical moving mean and moving covariance calculations. The nodes are implemented in the network architecture by using a Gaussian, rather than sigmoidal, transfer function acting on the input from numerous connections. Each connection is analogous to a separate dimension for the Gaussian function. The learning scheme is a one-pass method, eliminating the need for repetitive presentation of the teaching stimuli. The Gaussian classes developed are representative of the statistics of the teaching data and act as templates in classifying novel inputs. The input layer employs a time-based decay to develop a time-ordered representation of the input stimuli. This temporal pattern recognition architecture is used to perform multi-sensor fusion and scene analysis for ROBART II, an autonomous sentry robot employing heterogeneous and homogeneous binary (on / off) sensors. The system receives sensor packets from ROBART indicating which sensors are active. The packets from various sensors are integrated in the input layer. As time progresses these sensor outputs become ordered, allowing the system to recognize activities which are dependent, not only on the individual events which make up the activity, but also on the order in which these events occur and their relative spacing throughout time. Each Gaussian classification node, representing a learned activity as an ordered sequence of sensor outputs, calculates its activation value independently, based on the activity in the input layer. These Gaussian activation values are then used to determine which, if any, of the learned sequences are present and with what confidence. The classification system is capable of recognizing activities despite missing

  8. Temporal patterns and geographic heterogeneity of Zika virus (ZIKV outbreaks in French Polynesia and Central America

    Directory of Open Access Journals (Sweden)

    Ying-Hen Hsieh

    2017-03-01

    Full Text Available Background Zika virus (ZIKV transmission has been reported in 67 countries/territories in the Oceania region and the Americas since 2015, prompting the World Health Organization (WHO to declare ZIKV as a Public Health Emergency of International Concern in February 2016, due to its strong association with medical complications such as microcephaly and Guillain–Barré Syndrome (GBS. However, a substantial gap in knowledge still exists regarding differing temporal pattern and potential of transmission of ZIKV in different regions of the world. Methods We use a phenomenological model to ascertain the temporal patterns and transmission potential of ZIKV in various countries/territories, by fitting the model to Zika case data from Yap Island and French Polynesia in the Oceania region and 11 countries/territories with confirmed case data, namely, Colombia, Ecuador, French Guiana, Guadeloupe, Guatemala, Mexico, Nicaragua, Panama, Puerto Rico, Saint Martin, and Suriname, to pinpoint the waves of infections in each country/territory and to estimate the respective basic reproduction number R0. Results Six of these time series datasets resulted in statistically significant model fit of at least one wave of reported cases, namely that of French Polynesia, Colombia, Puerto Rico, Guatemala, Suriname and Saint Martin. However, only Colombia and Guatemala exhibited two waves of cases while the others had only one wave. Temporal patterns of the second wave in Colombia and the single wave in Suriname are very similar, with the respective turning points separated by merely a week. Moreover, the mean estimates of R0 for Colombia, Guatemala and Suriname, all land-based populations, range between 1.05 and 1.75, while the corresponding mean estimates for R0 of island populations in French Polynesia, Puerto Rico and Saint Martin are significantly lower with a range of 5.70–6.89. We also fit the Richards model to Zika case data from six main archipelagos in French

  9. Detecting the community structure and activity patterns of temporal networks: a non-negative tensor factorization approach.

    Directory of Open Access Journals (Sweden)

    Laetitia Gauvin

    Full Text Available The increasing availability of temporal network data is calling for more research on extracting and characterizing mesoscopic structures in temporal networks and on relating such structure to specific functions or properties of the system. An outstanding challenge is the extension of the results achieved for static networks to time-varying networks, where the topological structure of the system and the temporal activity patterns of its components are intertwined. Here we investigate the use of a latent factor decomposition technique, non-negative tensor factorization, to extract the community-activity structure of temporal networks. The method is intrinsically temporal and allows to simultaneously identify communities and to track their activity over time. We represent the time-varying adjacency matrix of a temporal network as a three-way tensor and approximate this tensor as a sum of terms that can be interpreted as communities of nodes with an associated activity time series. We summarize known computational techniques for tensor decomposition and discuss some quality metrics that can be used to tune the complexity of the factorized representation. We subsequently apply tensor factorization to a temporal network for which a ground truth is available for both the community structure and the temporal activity patterns. The data we use describe the social interactions of students in a school, the associations between students and school classes, and the spatio-temporal trajectories of students over time. We show that non-negative tensor factorization is capable of recovering the class structure with high accuracy. In particular, the extracted tensor components can be validated either as known school classes, or in terms of correlated activity patterns, i.e., of spatial and temporal coincidences that are determined by the known school activity schedule.

  10. Detecting the community structure and activity patterns of temporal networks: a non-negative tensor factorization approach.

    Science.gov (United States)

    Gauvin, Laetitia; Panisson, André; Cattuto, Ciro

    2014-01-01

    The increasing availability of temporal network data is calling for more research on extracting and characterizing mesoscopic structures in temporal networks and on relating such structure to specific functions or properties of the system. An outstanding challenge is the extension of the results achieved for static networks to time-varying networks, where the topological structure of the system and the temporal activity patterns of its components are intertwined. Here we investigate the use of a latent factor decomposition technique, non-negative tensor factorization, to extract the community-activity structure of temporal networks. The method is intrinsically temporal and allows to simultaneously identify communities and to track their activity over time. We represent the time-varying adjacency matrix of a temporal network as a three-way tensor and approximate this tensor as a sum of terms that can be interpreted as communities of nodes with an associated activity time series. We summarize known computational techniques for tensor decomposition and discuss some quality metrics that can be used to tune the complexity of the factorized representation. We subsequently apply tensor factorization to a temporal network for which a ground truth is available for both the community structure and the temporal activity patterns. The data we use describe the social interactions of students in a school, the associations between students and school classes, and the spatio-temporal trajectories of students over time. We show that non-negative tensor factorization is capable of recovering the class structure with high accuracy. In particular, the extracted tensor components can be validated either as known school classes, or in terms of correlated activity patterns, i.e., of spatial and temporal coincidences that are determined by the known school activity schedule.

  11. Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis.

    Science.gov (United States)

    Coan, Ana Carolina; Campos, Brunno M; Bergo, Felipe P G; Kubota, Bruno Y; Yasuda, Clarissa L; Morita, Marcia E; Guerreiro, Carlos A M; Cendes, Fernando

    2015-02-01

    Patients with mesial temporal lobe epilepsy (MTLE) may present unstable pattern of seizures. We aimed to evaluate the occurrence of relapse-remitting seizures in MTLE with (MTLE-HS) and without (MTLE-NL) hippocampal sclerosis. We evaluated 172 patients with MTLE-HS (122) or MTLE-NL (50). Relapse-remitting pattern was defined as periods longer than two years of seizure-freedom intercalated with seizure recurrence. "Infrequent seizures" was considered as up to three seizures per year and "frequent seizures" as any period of seizures higher than that. Thirty-seven (30%) MTLE-HS and 18 (36%) MTLE-NL patients had relapse-remitting pattern (X2, p = 0.470). This was more common in those with infrequent seizures (X2, p seizure remission between the first and second decade of life (X2, p = 0.06). Similar proportion of MTLE-HS or MTLE-NL patients present relapse-remitting seizures and this occurs more often in those with infrequent seizures.

  12. Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis

    Directory of Open Access Journals (Sweden)

    Ana Carolina Coan

    2015-02-01

    Full Text Available Objective Patients with mesial temporal lobe epilepsy (MTLE may present unstable pattern of seizures. We aimed to evaluate the occurrence of relapse-remitting seizures in MTLE with (MTLE-HS and without (MTLE-NL hippocampal sclerosis. Method We evaluated 172 patients with MTLE-HS (122 or MTLE-NL (50. Relapse-remitting pattern was defined as periods longer than two years of seizure-freedom intercalated with seizure recurrence. “Infrequent seizures” was considered as up to three seizures per year and “frequent seizures” as any period of seizures higher than that. Results Thirty-seven (30% MTLE-HS and 18 (36% MTLE-NL patients had relapse-remitting pattern (X2, p = 0.470. This was more common in those with infrequent seizures (X2, p < 0.001. Twelve MTLE-HS and one MTLE-NL patients had prolonged seizure remission between the first and second decade of life (X2, p = 0.06. Conclusion Similar proportion of MTLE-HS or MTLE-NL patients present relapse-remitting seizures and this occurs more often in those with infrequent seizures.

  13. Population ecology of Paepalanthus polyanthus (Bong. Kunth: temporal variation in the pattern of spatial distribution

    Directory of Open Access Journals (Sweden)

    Tânia Tarabini Castellani

    2004-11-01

    Full Text Available The temporal variation in density and pattern of spatial distribution of Paepalanthus polyanthus (BONG. Kunth (Eriocaulaceae were evaluated at a determinate sand dune. This study was carried out over a period of five years, at three permanent plots of 25m2 in a sand dune slack at Joaquina Beach, Florianópolis, SC, Brazil. There were strong density fluctuations throughout these years. In areas 1, 2 and 3, the densities changed from 10.4, 2.2 and 1.8 plants/m2 in December 1986 to 75.8, 11.4 and 45.6 plants/m2 in December 1991. Area 3, situated on an elevated site, presented greater variation in density, with no live plants in December 1989 and 102.2 plants/m2 at the recruitment observed in May 1990. Despite these density fluctuations, the pattern of spatial distribution was always aggregated (Id>1, P<0.05. The greatest Id values occurred in periods of low density and not in those of high density, associated with seedling recruitment. Factors such as high seed production with low dispersal, massive germination in moit years and a comparatively high death rate of seedlings at sites more subject to flooding or more distant from the water table proved themselves able to promote this aggregate pattern and increase it during plant development.

  14. User Activity Recognition in Smart Homes Using Pattern Clustering Applied to Temporal ANN Algorithm

    Directory of Open Access Journals (Sweden)

    Serge Thomas Mickala Bourobou

    2015-05-01

    Full Text Available This paper discusses the possibility of recognizing and predicting user activities in the IoT (Internet of Things based smart environment. The activity recognition is usually done through two steps: activity pattern clustering and activity type decision. Although many related works have been suggested, they had some limited performance because they focused only on one part between the two steps. This paper tries to find the best combination of a pattern clustering method and an activity decision algorithm among various existing works. For the first step, in order to classify so varied and complex user activities, we use a relevant and efficient unsupervised learning method called the K-pattern clustering algorithm. In the second step, the training of smart environment for recognizing and predicting user activities inside his/her personal space is done by utilizing the artificial neural network based on the Allen’s temporal relations. The experimental results show that our combined method provides the higher recognition accuracy for various activities, as compared with other data mining classification algorithms. Furthermore, it is more appropriate for a dynamic environment like an IoT based smart home.

  15. Rationalizing spatial exploration patterns of wild animals and humans through a temporal discounting framework.

    Science.gov (United States)

    Namboodiri, Vijay Mohan K; Levy, Joshua M; Mihalas, Stefan; Sims, David W; Hussain Shuler, Marshall G

    2016-08-02

    Understanding the exploration patterns of foragers in the wild provides fundamental insight into animal behavior. Recent experimental evidence has demonstrated that path lengths (distances between consecutive turns) taken by foragers are well fitted by a power law distribution. Numerous theoretical contributions have posited that "Lévy random walks"-which can produce power law path length distributions-are optimal for memoryless agents searching a sparse reward landscape. It is unclear, however, whether such a strategy is efficient for cognitively complex agents, from wild animals to humans. Here, we developed a model to explain the emergence of apparent power law path length distributions in animals that can learn about their environments. In our model, the agent's goal during search is to build an internal model of the distribution of rewards in space that takes into account the cost of time to reach distant locations (i.e., temporally discounting rewards). For an agent with such a goal, we find that an optimal model of exploration in fact produces hyperbolic path lengths, which are well approximated by power laws. We then provide support for our model by showing that humans in a laboratory spatial exploration task search space systematically and modify their search patterns under a cost of time. In addition, we find that path length distributions in a large dataset obtained from free-ranging marine vertebrates are well described by our hyperbolic model. Thus, we provide a general theoretical framework for understanding spatial exploration patterns of cognitively complex foragers.

  16. User Activity Recognition in Smart Homes Using Pattern Clustering Applied to Temporal ANN Algorithm.

    Science.gov (United States)

    Bourobou, Serge Thomas Mickala; Yoo, Younghwan

    2015-05-21

    This paper discusses the possibility of recognizing and predicting user activities in the IoT (Internet of Things) based smart environment. The activity recognition is usually done through two steps: activity pattern clustering and activity type decision. Although many related works have been suggested, they had some limited performance because they focused only on one part between the two steps. This paper tries to find the best combination of a pattern clustering method and an activity decision algorithm among various existing works. For the first step, in order to classify so varied and complex user activities, we use a relevant and efficient unsupervised learning method called the K-pattern clustering algorithm. In the second step, the training of smart environment for recognizing and predicting user activities inside his/her personal space is done by utilizing the artificial neural network based on the Allen's temporal relations. The experimental results show that our combined method provides the higher recognition accuracy for various activities, as compared with other data mining classification algorithms. Furthermore, it is more appropriate for a dynamic environment like an IoT based smart home.

  17. Patterns of canopy and surface layer consumption in a boreal forest fire from repeat airborne lidar

    Science.gov (United States)

    Alonzo, Michael; Morton, Douglas C.; Cook, Bruce D.; Andersen, Hans-Erik; Babcock, Chad; Pattison, Robert

    2017-05-01

    Fire in the boreal region is the dominant agent of forest disturbance with direct impacts on ecosystem structure, carbon cycling, and global climate. Global and biome-scale impacts are mediated by burn severity, measured as loss of forest canopy and consumption of the soil organic layer. To date, knowledge of the spatial variability in burn severity has been limited by sparse field sampling and moderate resolution satellite data. Here, we used pre- and post-fire airborne lidar data to directly estimate changes in canopy vertical structure and surface elevation for a 2005 boreal forest fire on Alaska’s Kenai Peninsula. We found that both canopy and surface losses were strongly linked to pre-fire species composition and exhibited important fine-scale spatial variability at sub-30 m resolution. The fractional reduction in canopy volume ranged from 0.61 in lowland black spruce stands to 0.27 in mixed white spruce and broadleaf forest. Residual structure largely reflects standing dead trees, highlighting the influence of pre-fire forest structure on delayed carbon losses from aboveground biomass, post-fire albedo, and variability in understory light environments. Median loss of surface elevation was highest in lowland black spruce stands (0.18 m) but much lower in mixed stands (0.02 m), consistent with differences in pre-fire organic layer accumulation. Spatially continuous depth-of-burn estimates from repeat lidar measurements provide novel information to constrain carbon emissions from the surface organic layer and may inform related research on post-fire successional trajectories. Spectral measures of burn severity from Landsat were correlated with canopy (r = 0.76) and surface (r = -0.71) removal in black spruce stands but captured less of the spatial variability in fire effects for mixed stands (canopy r = 0.56, surface r = -0.26), underscoring the difficulty in capturing fire effects in heterogeneous boreal forest landscapes using proxy measures of burn

  18. Spatial and temporal patterns of rockfall activity - Drivers, precursors, kinetics and evolution

    Science.gov (United States)

    Dietze, Michael; Turowski, Jens; Hovius, Niels

    2017-04-01

    Rockfalls are key processes in steep alpine landscapes but hard to monitor by classic techniques under natural conditions due to their unpredictable and rapid evolution. In contrast, seismic methods allow rockfall event detection, localisation and tracking, describtion of the temporal evolution, of the precursor activity and of external triggers. To exploit these capabilities, a 700 m high, nearly vertical limestone cliff section in the Lauterbrunnen Valley, Bernese Oberland, Switzerland, was instrumented with six broadband seismometers for more than six months during two distinct campaigns: late summer/autumn 2014 and spring 2015. A total of 49 rockfalls events (17 in 2014 and 32 in 2015) were detected that occurred in the monitored cliff section. There were distinct spatial and temporal activity patterns at different observational scales: in summer/autumn rockfalls detached near the cliff base of the southern part, whereas in spring material was released at the upper and middle cliff parts from three activity hotspots - a downward annual vertical activity shift of 40-50 m/month. Rockfalls can be classified into three evolutionary types ("single impact", "multiple impact" and "avalanche-like") and showed seismic signals indicating precursor activity (e.g., crack propagation). Lag times for potential trigger mechanisms of 2-3 hours on average reveal that there is a tight temporal correlation of rockfall activity to rainfall and freeze-thaw transitions. Throughout the day, there are four distinct activity phases related to absolute temperature, temperature change rate and precipitation intensity. The contribution highlights the potential of environmental seismology to give profound and holistic insight into rockfall activity in a prototype landscape, representative for many other alpine catchments.

  19. Wildlife in the Matrix: Spatio-Temporal Patterns of Herbivore Occurrence in Karnataka, India

    Science.gov (United States)

    Karanth, Krithi K.

    2016-01-01

    Wildlife reserves are becoming increasingly isolated from the surrounding human-dominated landscapes particularly in Asia. It is imperative to understand how species are distributed spatially and temporally in and outside reserves, and what factors influence their occurrence. This study surveyed 7500 km2 landscape surrounding five reserves in the Western Ghats to examine patterns of occurrence of five herbivores: elephant, gaur, sambar, chital, and pig. Species distributions are modeled spatio-temporally using an occupancy approach. Trained field teams conducted 3860 interview-based occupancy surveys in a 10-km buffer surrounding these five reserves in 2012. I found gaur and wild pig to be the least and most wide-ranging species, respectively. Elephant and chital exhibit seasonal differences in spatial distribution unlike the other three species. As predicted, distance to reserve, the reserve itself, and forest cover were associated with higher occupancy of all species, and higher densities of people negatively influenced occurrence of all species. Park management, species protection, and conflict mitigation efforts in this landscape need to incorporate temporal and spatial understanding of species distributions. All species are known crop raiders and conflict prone locations with resources (such as water and forage) have to be monitored and managed carefully. Wildlife reserves and adjacent areas are critical for long-term persistence and habitat use for all five herbivores and must be monitored to ensure wildlife can move freely. Such a large-scale approach to map and monitor species distributions can be adapted to other landscapes to identify and monitor critical habitats shared by people and wildlife.

  20. Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes.

    Science.gov (United States)

    Leong, Misha; Roderick, George K

    2015-01-01

    Global change has led to shifts in phenology, potentially disrupting species interactions such as plant-pollinator relationships. Advances in remote sensing techniques allow one to detect vegetation phenological diversity between different land use types, but it is not clear how this translates to other communities in the ecosystem. Here, we investigated the phenological diversity of the vegetation across a human-altered landscape including urban, agricultural, and natural land use types. We found that the patterns of change in the vegetation indices (EVI and NDVI) of human-altered landscapes are out of synchronization with the phenology in neighboring natural California grassland habitat. Comparing these findings to a spatio-temporal pollinator distribution dataset, EVI and NDVI were significant predictors of total bee abundance, a relationship that improved with time lags. This evidence supports the importance of differences in temporal dynamics between land use types. These findings also highlight the potential to utilize remote sensing data to make predictions for components of biodiversity that have tight vegetation associations, such as pollinators.

  1. Geostatistical Analysis on the Temporal Patterns of the Yellow Rice Borer, Tryporyza incertulas

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhe-ming; WANG Zhi; HU Xiang-yue

    2005-01-01

    In order to comprehend temporal pattern of the larvae population of the yellow rice borer, Tryporyza incertulas, and provide valuable information for its forecast model, the data series of the population for each generation and the over-wintered larvae from 1960 to 1990 in Dingcheng District, Changde City, Hunan Province, were analyzed with geostatistics. The data series of total number,the 1 st generation, the 3rd generation and the over-wintered larvae year to year displayed rather better autocorrelation and prediction.The data series of generation to generation, the 2nd generation and the 4th generation year to year, however, demonstrated poor autocorrelation, especially for the 4th generation, whose autocorrelation degree was zero. The population dynamics of the yellow rice borer was obviously intermittent. A remarkable cycle of four generations, one year, was observed in the population of generation to generation. Omitting the certain generation or interposing the over-wintered larvae only resulted in a less or slight change of autocorrelation of the whole data series generation to generation. Crop system, food, climate and natural enemies, therefore, played more important roles in regulating the population dynamics than base number of the larvae. The basic techniques of geostatistics applied in analyzing temporal population dynamics were outlined.

  2. Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes

    Directory of Open Access Journals (Sweden)

    Misha Leong

    2015-08-01

    Full Text Available Global change has led to shifts in phenology, potentially disrupting species interactions such as plant–pollinator relationships. Advances in remote sensing techniques allow one to detect vegetation phenological diversity between different land use types, but it is not clear how this translates to other communities in the ecosystem. Here, we investigated the phenological diversity of the vegetation across a human-altered landscape including urban, agricultural, and natural land use types. We found that the patterns of change in the vegetation indices (EVI and NDVI of human-altered landscapes are out of synchronization with the phenology in neighboring natural California grassland habitat. Comparing these findings to a spatio-temporal pollinator distribution dataset, EVI and NDVI were significant predictors of total bee abundance, a relationship that improved with time lags. This evidence supports the importance of differences in temporal dynamics between land use types. These findings also highlight the potential to utilize remote sensing data to make predictions for components of biodiversity that have tight vegetation associations, such as pollinators.

  3. Precision phenotyping of biomass accumulation in triticale reveals temporal genetic patterns of regulation

    Science.gov (United States)

    Busemeyer, Lucas; Ruckelshausen, Arno; Möller, Kim; Melchinger, Albrecht E.; Alheit, Katharina V.; Maurer, Hans Peter; Hahn, Volker; Weissmann, Elmar A.; Reif, Jochen C.; Würschum, Tobias

    2013-08-01

    To extend agricultural productivity by knowledge-based breeding and tailor varieties adapted to specific environmental conditions, it is imperative to improve our ability to assess the dynamic changes of the phenome of crops under field conditions. To this end, we have developed a precision phenotyping platform that combines various sensors for a non-invasive, high-throughput and high-dimensional phenotyping of small grain cereals. This platform yielded high prediction accuracies and heritabilities for biomass of triticale. Genetic variation for biomass accumulation was dissected with 647 doubled haploid lines derived from four families. Employing a genome-wide association mapping approach, two major quantitative trait loci (QTL) for biomass were identified and the genetic architecture of biomass accumulation was found to be characterized by dynamic temporal patterns. Our findings highlight the potential of precision phenotyping to assess the dynamic genetics of complex traits, especially those not amenable to traditional phenotyping.

  4. Blood DNA methylation pattern is altered in mesial temporal lobe epilepsy

    Science.gov (United States)

    Long, Hong-Yu; Feng, Li; Kang, Jin; Luo, Zhao-Hui; Xiao, Wen-Biao; Long, Li-Li; Yan, Xiao-Xin; Zhou, Luo; Xiao, Bo

    2017-01-01

    Mesial temporal lobe epilepsy (MTLE) is a common epileptic disorder; little is known whether it is associated with peripheral epigenetic changes. Here we compared blood whole genomic DNA methylation pattern in MTLE patients (n = 30) relative to controls (n = 30) with the Human Methylation 450 K BeadChip assay, and explored genes and pathways that were differentially methylated using bioinformatics profiling. The MTLE and control groups showed significantly different (P drug metabolism, with the most distinct ones included SLC34A2, CLCN6, CLCA4, CYP3A43, CYP3A4 and CYP2C9. Among the MTLE patients, panels of genes also appeared to be differentially methylated relative to disease duration, resistance to anti-epileptics and MRI alterations of hippocampal sclerosis. The peripheral epigenetic changes observed in MTLE could be involved in certain disease-related modulations and warrant further translational investigations. PMID:28276448

  5. Temporal patterns of emergency calls of a metropolitan city in China

    Science.gov (United States)

    Wang, Wenjun; Yuan, Ning; Pan, Lin; Jiao, Pengfei; Dai, Weidi; Xue, Guixiang; Liu, Dong

    2015-10-01

    Quantitative understanding of human communication behavior, one of the fundamental human activities, is of great value in many practical problems, ranging from urban planning to emergency management. Most of the recent studies have focused on human communication under normal situations. Here, we study the temporal patterns of emergency calls, which is a special kind of human communication activity under emergency circumstances, by analyzing a dataset of emergency call records that collected from a metropolitan city in China during a five year period. We find that most individuals rarely make emergency calls. The distribution of inter-call durations decays as double power law along with an exponential tail. We also discover that, comparing with the normal communication activities, the activity of calling the emergency number shows more significant characteristics of burstiness and memory. We further demonstrate that the behavior of calling the emergency number when people encounter extreme events could be explained by an event-driven memory process.

  6. Spatio-temporal patterns in ultra-slow domain wall creep dynamics

    CERN Document Server

    Ferrero, Ezequiel E; Giamarchi, Thierry; Kolton, Alejandro B; Rosso, Alberto

    2016-01-01

    In presence of impurities, ferromagnetic and ferroelectric domain walls slide only above a finite external field. Close to this depinning threshold, the wall proceeds by large and abrupt jumps, called avalanches, while, at much smaller field, it creeps by thermal activation. In this work we develop a novel numerical technique that captures the ultra-slow creep regime over huge time scales. We point out the existence of activated events that involve collective reorganizations similar to avalanches, but, at variance with them, display correlated spatio-temporal patterns that resemble the complex sequence of aftershocks observed after a large earthquake. Remarkably, we show that events assembly in independent clusters owning the same scale-free statistics as critical depinning avalanches. This correlated dynamics should be experimentally accessible by magneto-optical imaging of ferro- magnetic films.

  7. Phase extraction from two phase-shifting fringe patterns using spatial-temporal fringes method.

    Science.gov (United States)

    Zhu, Ronggang; Li, Bo; Zhu, Rihong; He, Yong; Li, Jianxin

    2016-04-04

    Phase extraction from phase-shifting fringe patterns with unknown phase shift values is a valuable but challenging task, especially when there are only two frames of fringes. In this paper, a phase demodulation method based on the spatial-temporal fringes (STF) method is proposed, where two phase shift fringes with linear carrier are fused into one STF image, and then the measured phase can be extracted from its frequency spectrum. The algorithm is deduced by extending the traditional STF theory with at least three frames of fringes to the two frames case. In the simulations, its performance is compared with the classical Fourier Transform method, and the different carrier and phase step conditions are analyzed where the accuracy can be ensured in most cases. The algorithm is also validated by the experiment, where the reliable result can be given even if the phase shift changes within a wide range.

  8. Reconstructing spatial and temporal patterns of paleoglaciation along the Tian Shan

    Science.gov (United States)

    Harbor, J.; Stroeven, A. P.; Beel, C.; Blomdin, R.; Caffee, M. W.; Chen, Y.; Codilean, A.; Gribenski, N.; Hattestrand, C.; Heyman, J.; Ivanov, M.; Kassab, C.; Li, Y.; Lifton, N. A.; Liu, G.; Petrakov, D.; Rogozhina, I.; Usubaliev, R.

    2012-12-01

    Testing and calibrating global climate models require well-constrained information on past climates of key regions around the world. Particularly important are transitional regions that provide a sensitive record of past climate change. Central Asia is an extreme continental location with glaciers and rivers that respond sensitively to temporal variations in the dominance of several major climate systems. As an international team initiative, we are reconstructing the glacial history of the Kyrgyz and Chinese Tian Shan, based on mapping and dating of key localities along the range. Remote-sensing-based geomorphological mapping, building on previous maps produced by Kyrgyz, Russian, Chinese and German scholars, is being augmented with field observations of glacial geomorphology and the maximum distribution of erratics. We are using cosmogenic nuclide (CN) 10Be dating of moraines and other landforms that constrain the former maximum extents of glaciers. Study sites include the Ala-Archa, Ak-Shyrak and Inylchek/Sary-Dzaz areas in Kyrgyzstan and the Urumqi valley (as well as its upland and southern slopes), and the Tumur and Bogeda peak areas in China. Comparing consistently dated glacial histories along and across the range will allow us to examine potential shifts in the dominance patterns of climate systems over time in Central Asia. We are also comparing ages based on CN with optically stimulated luminescence (OSL) and electron spin resonance (ESR) dates. The final stage of this project will use intermediate complexity glacier flow models to examine paleoclimatic implications of the observed spatial and temporal patterns of glacier changes across Central Asia and eastern Tibet, focused in particular on the last glacial cycle.

  9. Analysis of Spatio-Temporal Traffic Patterns Based on Pedestrian Trajectories

    Science.gov (United States)

    Busch, S.; Schindler, T.; Klinger, T.; Brenner, C.

    2016-06-01

    For driver assistance and autonomous driving systems, it is essential to predict the behaviour of other traffic participants. Usually, standard filter approaches are used to this end, however, in many cases, these are not sufficient. For example, pedestrians are able to change their speed or direction instantly. Also, there may be not enough observation data to determine the state of an object reliably, e.g. in case of occlusions. In those cases, it is very useful if a prior model exists, which suggests certain outcomes. For example, it is useful to know that pedestrians are usually crossing the road at a certain location and at certain times. This information can then be stored in a map which then can be used as a prior in scene analysis, or in practical terms to reduce the speed of a vehicle in advance in order to minimize critical situations. In this paper, we present an approach to derive such a spatio-temporal map automatically from the observed behaviour of traffic participants in everyday traffic situations. In our experiments, we use one stationary camera to observe a complex junction, where cars, public transportation and pedestrians interact. We concentrate on the pedestrians trajectories to map traffic patterns. In the first step, we extract trajectory segments from the video data. These segments are then clustered in order to derive a spatial model of the scene, in terms of a spatially embedded graph. In the second step, we analyse the temporal patterns of pedestrian movement on this graph. We are able to derive traffic light sequences as well as the timetables of nearby public transportation. To evaluate our approach, we used a 4 hour video sequence. We show that we are able to derive traffic light sequences as well as time tables of nearby public transportation.

  10. a Three-Step Spatial-Temporal Clustering Method for Human Activity Pattern Analysis

    Science.gov (United States)

    Huang, W.; Li, S.; Xu, S.

    2016-06-01

    How people move in cities and what they do in various locations at different times form human activity patterns. Human activity pattern plays a key role in in urban planning, traffic forecasting, public health and safety, emergency response, friend recommendation, and so on. Therefore, scholars from different fields, such as social science, geography, transportation, physics and computer science, have made great efforts in modelling and analysing human activity patterns or human mobility patterns. One of the essential tasks in such studies is to find the locations or places where individuals stay to perform some kind of activities before further activity pattern analysis. In the era of Big Data, the emerging of social media along with wearable devices enables human activity data to be collected more easily and efficiently. Furthermore, the dimension of the accessible human activity data has been extended from two to three (space or space-time) to four dimensions (space, time and semantics). More specifically, not only a location and time that people stay and spend are collected, but also what people "say" for in a location at a time can be obtained. The characteristics of these datasets shed new light on the analysis of human mobility, where some of new methodologies should be accordingly developed to handle them. Traditional methods such as neural networks, statistics and clustering have been applied to study human activity patterns using geosocial media data. Among them, clustering methods have been widely used to analyse spatiotemporal patterns. However, to our best knowledge, few of clustering algorithms are specifically developed for handling the datasets that contain spatial, temporal and semantic aspects all together. In this work, we propose a three-step human activity clustering method based on space, time and semantics to fill this gap. One-year Twitter data, posted in Toronto, Canada, is used to test the clustering-based method. The results show that the

  11. A THREE-STEP SPATIAL-TEMPORAL-SEMANTIC CLUSTERING METHOD FOR HUMAN ACTIVITY PATTERN ANALYSIS

    Directory of Open Access Journals (Sweden)

    W. Huang

    2016-06-01

    Full Text Available How people move in cities and what they do in various locations at different times form human activity patterns. Human activity pattern plays a key role in in urban planning, traffic forecasting, public health and safety, emergency response, friend recommendation, and so on. Therefore, scholars from different fields, such as social science, geography, transportation, physics and computer science, have made great efforts in modelling and analysing human activity patterns or human mobility patterns. One of the essential tasks in such studies is to find the locations or places where individuals stay to perform some kind of activities before further activity pattern analysis. In the era of Big Data, the emerging of social media along with wearable devices enables human activity data to be collected more easily and efficiently. Furthermore, the dimension of the accessible human activity data has been extended from two to three (space or space-time to four dimensions (space, time and semantics. More specifically, not only a location and time that people stay and spend are collected, but also what people “say” for in a location at a time can be obtained. The characteristics of these datasets shed new light on the analysis of human mobility, where some of new methodologies should be accordingly developed to handle them. Traditional methods such as neural networks, statistics and clustering have been applied to study human activity patterns using geosocial media data. Among them, clustering methods have been widely used to analyse spatiotemporal patterns. However, to our best knowledge, few of clustering algorithms are specifically developed for handling the datasets that contain spatial, temporal and semantic aspects all together. In this work, we propose a three-step human activity clustering method based on space, time and semantics to fill this gap. One-year Twitter data, posted in Toronto, Canada, is used to test the clustering-based method. The

  12. Zebrafish: an exciting model for investigating the spatio-temporal pattern of enteric nervous system development.

    LENUS (Irish Health Repository)

    Doodnath, Reshma

    2012-02-01

    AIM: Recently, the zebrafish (Danio rerio) has been shown to be an excellent model for human paediatric research. Advantages over other models include its small size, externally visually accessible development and ease of experimental manipulation. The enteric nervous system (ENS) consists of neurons and enteric glia. Glial cells permit cell bodies and processes of neurons to be arranged and maintained in a proper spatial arrangement, and are essential in the maintenance of basic physiological functions of neurons. Glial fibrillary acidic protein (GFAP) is expressed in astrocytes, but also expressed outside of the central nervous system. The aim of this study was to investigate the spatio-temporal pattern of GFAP expression in developing zebrafish ENS from 24 h post-fertilization (hpf), using transgenic fish that express green fluorescent protein (GFP). METHODS: Zebrafish embryos were collected from transgenic GFP Tg(GFAP:GFP)(mi2001) adult zebrafish from 24 to 120 hpf, fixed and processed for whole mount immunohistochemistry. Antibodies to Phox2b were used to identify enteric neurons. Specimens were mounted on slides and imaging was performed using a fluorescent laser confocal microscope. RESULTS: GFAP:GFP labelling outside the spinal cord was identified in embryos from 48 hpf. The patterning was intracellular and consisted of elongated profiles that appeared to migrate away from the spinal cord into the periphery. At 72 and 96 hpf, GFAP:GFP was expressed dorsally and ventrally to the intestinal tract. At 120 hpf, GFAP:GFP was expressed throughout the intestinal wall, and clusters of enteric neurons were identified using Phox2b immunofluorescence along the pathway of GFAP:GFP positive processes, indicative of a migratory pathway of ENS precursors from the spinal cord into the intestine. CONCLUSION: The pattern of migration of GFAP:GFP expressing cells outside the spinal cord suggests an organized, early developing migratory pathway to the ENS. This shows for the

  13. α-Calcium calmodulin kinase II modulates the temporal structure of hippocampal bursting patterns.

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    Jeiwon Cho

    Full Text Available The alpha calcium calmodulin kinase II (α-CaMKII is known to play a key role in CA1/CA3 synaptic plasticity, hippocampal place cell stability and spatial learning. Additionally, there is evidence from hippocampal electrophysiological slice studies that this kinase has a role in regulating ion channels that control neuronal excitability. Here, we report in vivo single unit studies, with α-CaMKII mutant mice, in which threonine 305 was replaced with an aspartate (α-CaMKII(T305D mutants, that indicate that this kinase modulates spike patterns in hippocampal pyramidal neurons. Previous studies showed that α-CaMKII(T305D mutants have abnormalities in both hippocampal LTP and hippocampal-dependent learning. We found that besides decreased place cell stability, which could be caused by their LTP impairments, the hippocampal CA1 spike patterns of α-CaMKII(T305D mutants were profoundly abnormal. Although overall firing rate, and overall burst frequency were not significantly altered in these mutants, inter-burst intervals, mean number of intra-burst spikes, ratio of intra-burst spikes to total spikes, and mean intra-burst intervals were significantly altered. In particular, the intra burst intervals of place cells in α-CaMKII(T305D mutants showed higher variability than controls. These results provide in vivo evidence that besides its well-known function in synaptic plasticity, α-CaMKII, and in particular its inhibitory phosphorylation at threonine 305, also have a role in shaping the temporal structure of hippocampal burst patterns. These results suggest that some of the molecular processes involved in acquiring information may also shape the patterns used to encode this information.

  14. Temporal patterns in count-to-ten fetal movement charts and their associations with pregnancy characteristics: a prospective cohort study

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    Winje Brita Askeland

    2012-11-01

    Full Text Available Abstract Background Fetal movement counting has long been suggested as a screening tool to identify impaired placental function. However, quantitative limits for decreased fetal movement perform poorly for screening purposes, indicating the need for methodological refinement. We aimed to identify the main individual temporal patterns in fetal movement counting charts, and explore their associations with pregnancy characteristics. Methods In a population-based prospective cohort in Norway, 2009–2011, women with singleton pregnancies counted fetal movements daily from pregnancy week 24 until delivery using a modified "count-to-ten” procedure. To account for intra-woman correlation of observations, we used functional data analysis and corresponding functional principal component analysis to identify the main individual temporal patterns in fetal movement count data. The temporal patterns are described by continuous functional principal component (FPC curves, with an individual score on each FPC for each woman. These scores were later used as outcome variables in multivariable linear regression analyses, with pregnancy characteristics as explanatory variables. Results Fetal movement charts from 1086 pregnancies were included. Three FPC curves explained almost 99% of the variation in the temporal data, with the first FPC, representing the individual overall counting time, accounting for 91% alone. There were several statistically significant associations between the FPCs and various pregnancy characteristics. However, the effects were small and of limited clinical value. Conclusions This statistical approach for analyzing fetal movement counting data successfully captured clinically meaningful individual temporal patterns and how these patterns vary between women. Maternal body mass index, gestational age and placental site explained little of the variation in the temporal fetal movement counting patterns. Thus, a perceived decrease in fetal

  15. Repeated assessment of exploration and novelty seeking in the human behavioral pattern monitor in bipolar disorder patients and healthy individuals.

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    Arpi Minassian

    Full Text Available BACKGROUND: Exploration and novelty seeking are cross-species adaptive behaviors that are dysregulated in bipolar disorder (BD and are critical features of the illness. While these behaviors have been extensively quantified in animals, multivariate human paradigms of exploration are lacking. The human Behavioral Pattern Monitor (hBPM, a human version of the animal open field, identified a signature pattern of hyper-exploration in manic BD patients, but whether exploratory behavior changes with treatment is unknown. The objective of this study was to assess the sensitivity of the hBPM to changes in manic symptoms, a necessary step towards elucidating the neurobiology underlying BD. METHODOLOGY AND PRINCIPAL FINDINGS: Twelve acutely hospitalized manic BD subjects and 21 healthy volunteers were tested in the hBPM over three sessions; all subjects were retested one week after their first session and two weeks after their second session. Motor activity, spatial and entropic (degree of unpredictability patterns of exploration, and interactions with novel objects were quantified. Manic BD patients demonstrated greater motor activity, extensive and more unpredictable patterns of exploration, and more object interactions than healthy volunteers during all three sessions. Exploration and novelty-seeking slightly decreased in manic BD subjects over the three sessions as their symptoms responded to treatment, but never to the level of healthy volunteers. Among healthy volunteers, exploration did not significantly decrease over time, and hBPM measures were highly correlated between sessions. CONCLUSIONS/SIGNIFICANCE: Manic BD patients showed a modest reduction in symptoms yet still demonstrated hyper-exploration and novelty seeking in the hBPM, suggesting that these illness features may be enduring characteristics of BD. Furthermore, behavior in the hBPM is not subject to marked habituation effects. The hBPM can be reliably used in a repeated-measures design

  16. NFI-C2 temporal-spatial expression and cellular localization pattern during tooth formation.

    Science.gov (United States)

    Lamani, Ejvis; Gluhak-Heinrich, Jelica; MacDougall, Mary

    2015-12-01

    Currently, little is known regarding critical signaling pathways during later stages of tooth development, especially those associated with root formation. Nfi-c null mice, lacking molar roots, have implicated the transcription factor NFI-C as having an essential role in root development. Previously, we identified three NFI-C isoforms expressed in dental tissues with NFI-C2 being the major transcript. However, the expression pattern of the NFI-C2 protein is not characterized. In this study we performed in situ hybridization and immunohistochemistry using isoform specific probes. We show the production of a NFI-C2 peptide antibody, its characterization, the temporal-spatial expression pattern of the NFI-C2 protein during odontogenesis and sub-cellular localization in dental cells. Moderate NFI-C2 staining, as early as bud stage, was detected mostly in the condensing dental ectomesenchyme. This staining intensified within the dental pulp at later stages culminating in high expression in the dentin producing odontoblasts. The dental epithelium showed slight staining until cytodifferentiation of enamel organ into ameloblasts and stratum intermedium. During root formation NFI-C2 expression was high in the Hertwig's epithelial root sheath and later was found in the fully developed root and its supporting tissues. NFI-C2 cellular staining was cytosolic, associated with the Golgi, and nuclear. These data suggest a broader role for NFI-C during tooth formation than limited to root and periodontal ligament development. © 2015 Japanese Society of Developmental Biologists.

  17. Does sex matter? Temporal and spatial patterns of cougar-human conflict in British Columbia.

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    Kristine J Teichman

    Full Text Available Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality. We investigated the importance of cougar (Puma concolor habitat, human landscape characteristics and the combination of habitat and human features on the temporal and spatial patterns of cougar-human conflicts in British Columbia. Conflicts (n = 1,727; 1978-2007 involved similar numbers of male and female cougars with conflict rate decreasing over the past decade. Conflicts were concentrated within the southern part of the province with the most conflicts per unit area occurring on Vancouver Island. For both sexes, the most supported spatial models for the most recent (1998-2007 conflicts contained both human and habitat variables. Conflicts were more likely to occur close to roads, at intermediate elevations and far from the northern edge of the cougar distribution range in British Columbia. Male cougar conflicts were more likely to occur in areas of intermediate human density. Unlike cougar conflicts in other regions, cattle density was not a significant predictor of conflict location. With human populations expanding, conflicts are expected to increase. Conservation tools, such as the maps predicting conflict hotspots from this study, can help focus management efforts to decrease carnivore-human conflict.

  18. Temporal patterns in disparity and diversity of the Jurassic ammonoids of southern Germany

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    M. S. Simon

    2011-02-01

    Full Text Available A morphometric analysis of the characteristic whorl cross-sections of 1,200 Jurassic ammonoid species from southern Germany enabled us to characterise their morphospace. The successive Jurassic ammonoid faunas of southern Germany show characteristic patterns in morphospace occupation. While Early and Middle Jurassic ammonoids occupy limited areas of the morphospace range, the Late Jurassic ammonoids cover the entire spectrum. The ammonoids are characterised by an overall increase of both taxonomic diversity and morphological disparity in the course of the Jurassic. Strong fluctuations occur until the middle Late Jurassic, followed by a diversity decrease in the early Kimmeridgian and a disparity reduction in the early Tithonian. While diversity and disparity show similar progression during most of the Early Jurassic, they diverge subsequently and show only poor correlation until the end of the Jurassic. Particularly in the Middle Jurassic diversity and sea level changes correlate strongly. Neither temporal patterns in diversity nor disparity support the hypothesis of a mass extinction event in the early Toarcian. Significant changes in diversity and disparity in the early Callovian support a putative migration event of Boreal ammonoids into the Tethyan realm. doi:10.1002/mmng.201000016

  19. Direct Visualization of Spatial and Temporal Patterns of Antimicrobial Action within Model Oral Biofilms▿

    Science.gov (United States)

    Takenaka, Shoji; Trivedi, Harsh M.; Corbin, Audrey; Pitts, Betsey; Stewart, Philip S.

    2008-01-01

    A microscopic method for noninvasively visualizing the action of an antimicrobial agent inside a biofilm was developed and applied to describe spatial and temporal patterns of mouthrinse activity on model oral biofilms. Three species biofilms of Streptococcus oralis, Streptococcus gordonii, and Actinomyces naeslundii were grown in glass capillary flow cells. Bacterial cells were stained with the fluorogenic esterase substrate Calcien AM (CAM). Loss of green fluorescence upon exposure to an antimicrobial formulation was subsequently imaged by time-lapse confocal laser scanning microscopy. When an antimicrobial mouthrinse containing chlorhexidine digluconate was administered, a gradual loss of green fluorescence was observed that began at the periphery of cell clusters where they adjoined the flowing bulk fluid and progressed inward over a time period of several minutes. Image analysis was performed to quantify a penetration velocity of 4 μm/min. An enzyme-based antimicrobial formulation led to a gradual, continually slowing loss of fluorescence in a pattern that was qualitatively different from the behavior observed with chlorhexidine. Ethanol at 11.6% had little effect on the biofilm. None of these treatments resulted in the removal of biomass from the biofilm. Most methods to measure or visualize antimicrobial action in biofilms are destructive. Spatial information is important because biofilms are known for their structural and physiological heterogeneity. The CAM staining technique has the potential to provide information about the rate of antimicrobial penetration, the presence of tolerant subpopulations, and the extent of biomass removal effected by a treatment. PMID:18223108

  20. Temporal and spatial expression pattern of Nnat during mouse eye development.

    Science.gov (United States)

    Sel, Saadettin; Patzel, Eva; Poggi, Lucia; Kaiser, Delia; Kalinski, Thomas; Schicht, Martin; Paulsen, Friedrich; Nass, Norbert

    2017-01-01

    Neuronatin (Nnat) was initially identified as a highly expressed gene in neonatal mammalian brain. In this study, we analyze the spatial and temporal expression pattern of Nnat during mouse eye development as well as in the adult. The expression of Nnat was analyzed on mRNA as well as protein level. The presence of Nnat transcripts in the adult retina was examined using reverse transcription-polymerase chain reaction (RT-PCR). Nnat protein expression was evaluated by Western blot and immunohistochemistry during eye development at embryonic day (E) 12, 15, 16 and postnatal day (P) 7, 14, 30 and 175 (adult). Immunohistochemical studies of the developing mouse eye revealed Nnat expression in embryonic and adult neuroretina as well as in corneal epithelial, stromal, endothelial cells and in lens epithelium. Expression of Nnat was detected from E12 onwards and was also present in adult eyes. The expression pattern suggests that Nnat may play an important role during eye development and in the maintenance of mature eye. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Multi-instrument Method to Map Spatial and Temporal Patterns of Snowmelt Infiltration

    Science.gov (United States)

    Hyde, K.; Beverly, D.; Thayer, D.; Speckman, H. N.; Parsekian, A.; Kelleners, T.

    2015-12-01

    Mapping spatial patterns of relative soil moisture over time may improve understanding of snowmelt infiltration processes in heterogeneous systems. Conventional soil water measurement methods disturb soil properties and rocky materials generally limit installation of monitoring instruments to shallow depths in mountainous landscapes with snowmelt dominated hydrology. Modifications to existing technology combined with low impact installation methods provide high temporal and spatial resolution of relative soil moisture as well as a temperature profile and water table level. Closely spaced (10cm) electrical resistance pads are combined in a small diameter (2.54 cm) tube with temperature probes each 50cm, a pressure transducer, and a tube to extract groundwater for stable isotope analysis. This vertical probe array (VPA) extends 3.2m and is installed in a small diameter (4 cm) bore using a backpack drill limiting soil disturbance. Two VPAs are installed in the Snowy Range of Wyoming, one in a forested mountainous environment impacted by mortality by insects and disease and the other (limited to resistance pads only) in recently burned sagelands. Each VPA is co-located with meteorological stations. Eddy-covariance, sap flux, electrical resistivity, snowpack survey, and other hillslope eco-hydrology measurements accompany the fully instrumented VPA. Data are sampled and recorded at 5 or 15 minute intervals starting in December 2014. Over the winter both sites exhibit highly variable patterns of relatively dry soils with steady increase in wetness. Abrupt increases in relative wetness occurred with short periods of warming temperatures in Spring. Following a temperature increase in the forested site the relative moisture dramatically increased over a period of several hours at all depths as water level rose 1m within 8 hours. In contrast, following snowmelt relative moisture in the sageland site increased gradually and systematically with depth over a period of two weeks

  2. Spatio-temporal seasonal drought patterns in Europe from 1950 to 2015

    Science.gov (United States)

    Spinoni, Jonathan; Naumann, Gustavo; Vogt, Jürgen

    2016-04-01

    Drought is one of the natural disasters with severe impacts in Europe, not only in areas which frequently experience water scarcity such as the Mediterranean, but also in temperate or continental climates such as Central and Eastern Europe and even in cold regions such as Scandinavia and Iceland. In this study the spatio-temporal patterns of seasonal meteorological droughts in Europe between 1950 and 2015 are investigated using the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). Since the focus is on the analysis of seasonal drought trends, indicators were calculated for 3 monthly accumulation periods. The input variables of precipitation and temperature were derived from E-OBS grids (v11-v12) at a spatial resolution of 0.25°x0.25°. Seasonal trends of drought frequency and severity were analyzed for moderate (SPI or SPEI SPEI droughts in Northern Europe and Russia, especially in winter and spring; oppositely, an increasing trend is visible in Southern Europe, mainly in spring and summer. According to the SPEI analysis (precipitation and temperature driven) Northern Europe shows wetting patterns, while Southern and Eastern Europe show a more remarkable drying tendency, especially in summer and autumn for drought frequency and in every season for drought severity. The evolution towards drier conditions is more relevant from 1981 onwards, both in terms of frequency and severity. This is especially true for Central Europe in spring, for the Mediterranean in summer, and for Eastern Europe in autumn. Extreme events follow similar patterns, but in autumn no spatially coherent trend can be found.

  3. Understanding flood-induced water chemistry variability extracting temporal patterns with the LDA method

    Science.gov (United States)

    Aubert, A. H.; Tavenard, R.; Emonet, R.; De Lavenne, A.; Malinowski, S.; Guyet, T.; Quiniou, R.; Odobez, J.; Merot, P.; Gascuel-odoux, C.

    2013-12-01

    Studying floods has been a major issue in hydrological research for years, both in quantitative and qualitative hydrology. Stream chemistry is a mix of solutes, often used as tracers, as they originate from various sources in the catchment and reach the stream by various flow pathways. Previous studies (for instance (1)) hypothesized that stream chemistry reaction to a rainfall event is not unique but varies seasonally, and according to the yearly meteorological conditions. Identifying a typology of flood temporal chemical patterns is a way to better understand catchment processes at the flood and seasonal time scale. We applied a probabilistic model (Latent Dirichlet Allocation or LDA (2)) mining recurrent sequential patterns from a dataset of floods. A set of 472 floods was automatically extracted from a daily 12-year long record of nitrate, dissolved organic carbon, sulfate and chloride concentrations. Rainfall, discharge, water table depth and temperature are also considered. Data comes from a long-term hydrological observatory (AgrHys, western France) located at Kervidy-Naizin. From each flood, a document has been generated that is made of a set of "hydrological words". Each hydrological word corresponds to a measurement: it is a triplet made of the considered variable, the time at which the measurement is made (relative to the beginning of the flood), and its magnitude (that can be low, medium or high). The documents and the number of pattern to be mined are used as input data to the LDA algorithm. LDA relies on spotting co-occurrences (as an alternative to the more traditional study of correlation) between words that appear within the flood documents. It has two nice properties that are its ability to easily deal with missing data and its additive property that allows a document to be seen as a mixture of several flood patterns. The output of LDA is a set of patterns easily represented in graphics. These patterns correspond to typical reactions to rainfall

  4. Spatial and temporal statistical analysis of bycatch data: Patterns of sea turtle bycatch in the North Atlantic

    Science.gov (United States)

    Gardner, B.; Sullivan, P.J.; Morreale, S.J.; Epperly, S.P.

    2008-01-01

    Loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtle distributions and movements in offshore waters of the western North Atlantic are not well understood despite continued efforts to monitor, survey, and observe them. Loggerhead and leatherback sea turtles are listed as endangered by the World Conservation Union, and thus anthropogenic mortality of these species, including fishing, is of elevated interest. This study quantifies spatial and temporal patterns of sea turtle bycatch distributions to identify potential processes influencing their locations. A Ripley's K function analysis was employed on the NOAA Fisheries Atlantic Pelagic Longline Observer Program data to determine spatial, temporal, and spatio-temporal patterns of sea turtle bycatch distributions within the pattern of the pelagic fishery distribution. Results indicate that loggerhead and leatherback sea turtle catch distributions change seasonally, with patterns of spatial clustering appearing from July through October. The results from the space-time analysis indicate that sea turtle catch distributions are related on a relatively fine scale (30-200 km and 1-5 days). The use of spatial and temporal point pattern analysis, particularly K function analysis, is a novel way to examine bycatch data and can be used to inform fishing practices such that fishing could still occur while minimizing sea turtle bycatch. ?? 2008 NRC.

  5. Selecting a linear mixed model for longitudinal data: repeated measures analysis of variance, covariance pattern model, and growth curve approaches.

    Science.gov (United States)

    Liu, Siwei; Rovine, Michael J; Molenaar, Peter C M

    2012-03-01

    With increasing popularity, growth curve modeling is more and more often considered as the 1st choice for analyzing longitudinal data. Although the growth curve approach is often a good choice, other modeling strategies may more directly answer questions of interest. It is common to see researchers fit growth curve models without considering alterative modeling strategies. In this article we compare 3 approaches for analyzing longitudinal data: repeated measures analysis of variance, covariance pattern models, and growth curve models. As all are members of the general linear mixed model family, they represent somewhat different assumptions about the way individuals change. These assumptions result in different patterns of covariation among the residuals around the fixed effects. In this article, we first indicate the kinds of data that are appropriately modeled by each and use real data examples to demonstrate possible problems associated with the blanket selection of the growth curve model. We then present a simulation that indicates the utility of Akaike information criterion and Bayesian information criterion in the selection of a proper residual covariance structure. The results cast doubt on the popular practice of automatically using growth curve modeling for longitudinal data without comparing the fit of different models. Finally, we provide some practical advice for assessing mean changes in the presence of correlated data.

  6. Repeated measurements of cerebral blood flow in the left superior temporal gyrus reveal tonic hyperactivity in patients with auditory verbal hallucinations: A possible trait marker

    Directory of Open Access Journals (Sweden)

    Philipp eHoman

    2013-06-01

    Full Text Available Background: The left superior temporal gyrus (STG has been suggested to play a key role in auditory verbal hallucinations in patients with schizophrenia. Methods: Eleven medicated subjects with schizophrenia and medication-resistant auditory verbal hallucinations and 19 healthy controls underwent perfusion magnetic resonance imaging with arterial spin labeling. Three additional repeated measurements were conducted in the patients. Patients underwent a treatment with transcranial magnetic stimulation (TMS between the first 2 measurements. The main outcome measure was the pooled cerebral blood flow (CBF, which consisted of the regional CBF measurement in the left superior temporal gyrus (STG and the global CBF measurement in the whole brain.Results: Regional CBF in the left STG in patients was significantly higher compared to controls (p < 0.0001 and to the global CBF in patients (p < 0.004 at baseline. Regional CBF in the left STG remained significantly increased compared to the global CBF in patients across time (p < 0.0007, and it remained increased in patients after TMS compared to the baseline CBF in controls (p < 0.0001. After TMS, PANSS (p = 0.003 and PSYRATS (p = 0.01 scores decreased significantly in patients.Conclusions: This study demonstrated tonically increased regional CBF in the left STG in patients with schizophrenia and auditory hallucinations despite a decrease in symptoms after TMS. These findings were consistent with what has previously been termed a trait marker of auditory verbal hallucinations in schizophrenia.

  7. Earthquake damage history in Israel and its close surrounding - evaluation of spatial and temporal patterns

    Science.gov (United States)

    Zohar, Motti; Salamon, Amos; Rubin, Rehav

    2017-01-01

    Israel was hit by destructive earthquakes many times in the course of history. To properly understand the hazard and support effective preparedness towards future earthquakes, we examined the spatial and temporal distribution of the resulted damage. We described in detail our systematic approach to searching the available literature, collecting the data and screening the authenticity of that information. We used GIS (Geographic Information System) to map and evaluate the distribution of the damage and to search for recurring patterns. Overall, it is found that 186 localities were hit, 54 of them at least twice. We also found that Israel was affected by 4, 17, 8 and 2 damaging earthquakes that originated, respectively, from the southern, central, central-northern and northern parts of the Dead Sea Transform (DST). The temporal appearance of the northern earthquakes is clustered; the central earthquakes are more regular in time, whereas no damage from the north-central and the central quakes, with the exception of the year 363 earthquake, seems to have occurred south of the Dead Sea region. Analyzing the distribution of the damage, we realized that the number of the damage reports reflects only half of the incidents that actually happened, attesting to incompleteness of the historical catalogue. Jerusalem is the most reported city with 14 entries, followed by Akko (Acre), Tiberias, Nablus and Tyre with 8, 7, 7 and 6 reports, respectively. In general, localities in the Galilee and north of it suffered more severely than localities in central Israel with the exception of Nablus and the localities along the coastal plain of Israel, most probably due to local site effects. For the sake of hazard management, these observations should be considered for future planning and risk mitigation.

  8. Interpreting the spatio-temporal patterns of sea turtle strandings: Going with the flow

    Science.gov (United States)

    Hart, K.M.; Mooreside, P.; Crowder, L.B.

    2006-01-01

    Knowledge of the spatial and temporal distribution of specific mortality sources is crucial for management of species that are vulnerable to human interactions. Beachcast carcasses represent an unknown fraction of at-sea mortalities. While a variety of physical (e.g., water temperature) and biological (e.g., decomposition) factors as well as the distribution of animals and their mortality sources likely affect the probability of carcass stranding, physical oceanography plays a major role in where and when carcasses strand. Here, we evaluate the influence of nearshore physical oceanographic and wind regimes on sea turtle strandings to decipher seasonal trends and make qualitative predictions about stranding patterns along oceanfront beaches. We use results from oceanic drift-bottle experiments to check our predictions and provide an upper limit on stranding proportions. We compare predicted current regimes from a 3D physical oceanographic model to spatial and temporal locations of both sea turtle carcass strandings and drift bottle landfalls. Drift bottle return rates suggest an upper limit for the proportion of sea turtle carcasses that strand (about 20%). In the South Atlantic Bight, seasonal development of along-shelf flow coincides with increased numbers of strandings of both turtles and drift bottles in late spring and early summer. The model also predicts net offshore flow of surface waters during winter - the season with the fewest relative strandings. The drift bottle data provide a reasonable upper bound on how likely carcasses are to reach land from points offshore and bound the general timeframe for stranding post-mortem (strandings follow a seasonal regime predictable from physical oceanography and mimicked by drift bottle experiments. Managers can use these findings to reevaluate incidental strandings limits and fishery takes for both nearshore and offshore mortality sources. ?? 2005 Elsevier Ltd. All rights reserved.

  9. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.

  10. Pigment patterns in the Arabian Sea: Spatio-temporal variability as observed by ADEOS

    Digital Repository Service at National Institute of Oceanography (India)

    Jadhav, N.A.; Rao, L.V.G.; Panigrahy, R.C.

    The spatial and temporal variations of the near-surface concentration of phytoplankton pigment observed by ADEOS during November 1996 - May 1997 are studied in relation to SST and winds. Monthly composite images from OCTS depict spatial and temporal...

  11. Decoding temporal structure in music and speech relies on shared brain resources but elicits different fine-scale spatial patterns.

    Science.gov (United States)

    Abrams, Daniel A; Bhatara, Anjali; Ryali, Srikanth; Balaban, Evan; Levitin, Daniel J; Menon, Vinod

    2011-07-01

    Music and speech are complex sound streams with hierarchical rules of temporal organization that become elaborated over time. Here, we use functional magnetic resonance imaging to measure brain activity patterns in 20 right-handed nonmusicians as they listened to natural and temporally reordered musical and speech stimuli matched for familiarity, emotion, and valence. Heart rate variability and mean respiration rates were simultaneously measured and were found not to differ between musical and speech stimuli. Although the same manipulation of temporal structure elicited brain activation level differences of similar magnitude for both music and speech stimuli, multivariate classification analysis revealed distinct spatial patterns of brain responses in the 2 domains. Distributed neuronal populations that included the inferior frontal cortex, the posterior and anterior superior and middle temporal gyri, and the auditory brainstem classified temporal structure manipulations in music and speech with significant levels of accuracy. While agreeing with previous findings that music and speech processing share neural substrates, this work shows that temporal structure in the 2 domains is encoded differently, highlighting a fundamental dissimilarity in how the same neural resources are deployed.

  12. Understanding spatial and temporal patterning of astrocyte calcium transients via interactions between network transport and extracellular diffusion

    Science.gov (United States)

    Shtrahman, E.; Maruyama, D.; Olariu, E.; Fink, C. G.; Zochowski, M.

    2017-02-01

    Astrocytes form interconnected networks in the brain and communicate via calcium signaling. We investigate how modes of coupling between astrocytes influence the spatio-temporal patterns of calcium signaling within astrocyte networks and specifically how these network interactions promote coordination within this group of cells. To investigate these complex phenomena, we study reduced cultured networks of astrocytes and neurons. We image the spatial temporal patterns of astrocyte calcium activity and quantify how perturbing the coupling between astrocytes influences astrocyte activity patterns. To gain insight into the pattern formation observed in these cultured networks, we compare the experimentally observed calcium activity patterns to the patterns produced by a reduced computational model, where we represent astrocytes as simple units that integrate input through two mechanisms: gap junction coupling (network transport) and chemical release (extracellular diffusion). We examine the activity patterns in the simulated astrocyte network and their dependence upon these two coupling mechanisms. We find that gap junctions and extracellular chemical release interact in astrocyte networks to modulate the spatiotemporal patterns of their calcium dynamics. We show agreement between the computational and experimental findings, which suggests that the complex global patterns can be understood as a result of simple local coupling mechanisms.

  13. Muscle wasting and the temporal gene expression pattern in a novel rat intensive care unit model

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    Llano-Diez Monica

    2011-12-01

    Full Text Available Abstract Background Acute quadriplegic myopathy (AQM or critical illness myopathy (CIM is frequently observed in intensive care unit (ICU patients. To elucidate duration-dependent effects of the ICU intervention on molecular and functional networks that control the muscle wasting and weakness associated with AQM, a gene expression profile was analyzed at time points varying from 6 hours to 14 days in a unique experimental rat model mimicking ICU conditions, i.e., post-synaptically paralyzed, mechanically ventilated and extensively monitored animals. Results During the observation period, 1583 genes were significantly up- or down-regulated by factors of two or greater. A significant temporal gene expression pattern was constructed at short (6 h-4 days, intermediate (5-8 days and long (9-14 days durations. A striking early and maintained up-regulation (6 h-14d of muscle atrogenes (muscle ring-finger 1/tripartite motif-containing 63 and F-box protein 32/atrogin-1 was observed, followed by an up-regulation of the proteolytic systems at intermediate and long durations (5-14d. Oxidative stress response genes and genes that take part in amino acid catabolism, cell cycle arrest, apoptosis, muscle development, and protein synthesis together with myogenic factors were significantly up-regulated from 5 to 14 days. At 9-14 d, genes involved in immune response and the caspase cascade were up-regulated. At 5-14d, genes related to contractile (myosin heavy chain and myosin binding protein C, regulatory (troponin, tropomyosin, developmental, caveolin-3, extracellular matrix, glycolysis/gluconeogenesis, cytoskeleton/sarcomere regulation and mitochondrial proteins were down-regulated. An activation of genes related to muscle growth and new muscle fiber formation (increase of myogenic factors and JunB and down-regulation of myostatin and up-regulation of genes that code protein synthesis and translation factors were found from 5 to 14 days. Conclusions Novel

  14. Iterating 'addiction': Residential relocation and the spatio-temporal production of alcohol and other drug consumption patterns.

    Science.gov (United States)

    Dilkes-Frayne, Ella; Fraser, Suzanne; Pienaar, Kiran; Kokanovic, Renata

    2017-06-01

    Addiction is generally understood to be characterised by a persistent pattern of regular, heavy alcohol and other drug consumption. Current models of addiction tend to locate the causes of these patterns within the body or brain of the individual, sidelining relational and contextual factors. Where space and place are acknowledged as key factors contributing to consumption, they tend to be conceived of as static or fixed, which limits their ability to account for the fluid production and modulation of consumption patterns over time. In this article we query individualised and decontextualised understandings of the causes of consumption patterns through an analysis of accounts of residential relocation from interviews undertaken for a large research project on experiences of addiction in Australia. In conducting our analysis we conceptualise alcohol and other drug consumption patterns using Karen Barad's notions of intra-action and spatio-temporality, which allow for greater attention to be paid to the spatial and temporal dimensions of the material and social processes involved in generating consumption patterns. Drawing on 60 in-depth interviews conducted with people who self-identified as experiencing an alcohol and other drug addiction, dependence or habit, our analysis focuses on the ways in which participant accounts of moving enacted space and time as significant factors in how patterns of consumption were generated, disrupted and maintained. Our analysis explores how consumption patterns arose within highly localised relations, demonstrating the need for understandings of consumption patterns that acknowledge the indivisibility of space and time in their production. In concluding, we argue for a move away from static conceptions of place towards a more dynamic conception of spatio-temporality, and suggest the need to consider avenues for more effectively integrating place and time into strategies for generating preferred consumption patterns and initiating

  15. Temporal variability and persistence of soil CO2 efflux spatial patterns at a mowed and a grazed grassland

    Science.gov (United States)

    Fóti, Szilvia; Balogh, János; Papp, Marianna; Koncz, Péter; Nagy, Zoltán

    2017-04-01

    Spatial patterns of ecosystem processes constitute significant uncertainty sources in greenhouse gas flux estimations partly because of the temporal dynamics of the patterns. The aim of this study was to describe the temporal variability of grassland CO2 flux spatial patterns under varying environmental conditions and to assess the effects of the grassland management (grazing and mowing) in pattern modifications. For this reason, we conducted spatial measurements on soil respiration (Rs), soil water content (SWC) and soil temperature (Ts) 9 times during a four-year study in the vegetation periods at grazed and mowed grasslands. Altitude (ALT) of the measuring positions were used as background factor, while SWC and Ts were considered as abiotic co-variables in the spatial analysis. The sampling scheme was based on 80×60 m grids of 10 m resolution with a total of 78 sampling points in both study plots. Data analysis was based on variography and kriging. Altitude showed autocorrelation lengths of 40-50 m in both plots and was an important factor in determining the spatial patterns of the co-variables. Soil water content changed in general inversely, while Ts changed jointly with ALT. Autocorrelation lengths of the Rs patterns were similarly about 30 m on average in both plots. Grazing potentially created increased heterogeneity and regulation of the patterns, while mowing appeared to have had a homogenizing effect resulting in a lesser degree of pattern regulation. We found that SWC and Rs patterns were temporally variable especially in the first two years of the experiment, while these patterns were more persistent (mostly significant correlation at p<0.05 between location ranks) in the second two years, following a wet year. Increased persistence after a wet year indicated not only the homogenizing effect of adequate water supply conditions but also the recovery potential of the grassland after droughts.

  16. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation.

    Science.gov (United States)

    Sako, Keisuke; Pradhan, Saurabh J; Barone, Vanessa; Inglés-Prieto, Álvaro; Müller, Patrick; Ruprecht, Verena; Čapek, Daniel; Galande, Sanjeev; Janovjak, Harald; Heisenberg, Carl-Philipp

    2016-07-19

    During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc) in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation.

  17. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation

    Directory of Open Access Journals (Sweden)

    Keisuke Sako

    2016-07-01

    Full Text Available During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation.

  18. Effects of Temporal Sequencing and Auditory Discrimination on Children's Memory Patterns for Tones, Numbers, and Nonsense Words

    Science.gov (United States)

    Gromko, Joyce Eastlund; Hansen, Dee; Tortora, Anne Halloran; Higgins, Daniel; Boccia, Eric

    2009-01-01

    The purpose of this study was to determine whether children's recall of tones, numbers, and words was supported by a common temporal sequencing mechanism; whether children's patterns of memory for tones, numbers, and nonsense words were the same despite differences in symbol systems; and whether children's recall of tones, numbers, and nonsense…

  19. Effects of Temporal Sequencing and Auditory Discrimination on Children's Memory Patterns for Tones, Numbers, and Nonsense Words

    Science.gov (United States)

    Gromko, Joyce Eastlund; Hansen, Dee; Tortora, Anne Halloran; Higgins, Daniel; Boccia, Eric

    2009-01-01

    The purpose of this study was to determine whether children's recall of tones, numbers, and words was supported by a common temporal sequencing mechanism; whether children's patterns of memory for tones, numbers, and nonsense words were the same despite differences in symbol systems; and whether children's recall of tones, numbers, and nonsense…

  20. Probing on suitability of TRMM data to explain spatio-temporal pattern of severe storms in tropic region

    Directory of Open Access Journals (Sweden)

    A. Akbari

    2011-10-01

    Full Text Available Spatial and temporal pattern of rainfall play an important role in runoff generation. Raingauge density influences the accuracy of spatial pattern and time interval influence the accuracy of temporal pattern of storms. Usually due to practical and financial limitation the perfect distribution is not achievable. Several sources of data are used to define the behavior of rainfall over a watershed. Raingauges station, radar operation and satellite sensor are the main source of rainfall estimation over the space and time. Recording raingauges are the most common source of rainfall data in many countries. However raingauge network has not adequate coverage in many watersheds spatially in developing countries. Therefore other global source of rainfall data may be useful for hydrological analysis such as flood modeling. This research assessed the ability of TRMM rainfall estimates for explain the Spatio-temporal pattern of severe storm over Klang watershed which is a hydrologically well instrumented watershed. It was experienced that TRMM rainfall estimates are 35% less than actual data for the investigated events. Due to coarse temporal resolution of TRMM (3 h compare to gauge rainfall (15 min, significant uncertainty influences identifying the start and end of storm event and consequently their resultant time to peak of flood hydrograph which is extremely important in flood forecasting systems. Due to coarse pixel size of TRMM data, watershed scale is important issue.

  1. Multivariate pattern analysis reveals anatomical connectivity differences between the left and right mesial temporal lobe epilepsy

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    Peng Fang

    2015-01-01

    Full Text Available Previous studies have demonstrated differences of clinical signs and functional brain network organizations between the left and right mesial temporal lobe epilepsy (mTLE, but the anatomical connectivity differences underlying functional variance between the left and right mTLE remain uncharacterized. We examined 43 (22 left, 21 right mTLE patients with hippocampal sclerosis and 39 healthy controls using diffusion tensor imaging. After the whole-brain anatomical networks were constructed for each subject, multivariate pattern analysis was applied to classify the left mTLE from the right mTLE and extract the anatomical connectivity differences between the left and right mTLE patients. The classification results reveal 93.0% accuracy for the left mTLE versus the right mTLE, 93.4% accuracy for the left mTLE versus controls and 90.0% accuracy for the right mTLE versus controls. Compared with the right mTLE, the left mTLE exhibited a different connectivity pattern in the cortical-limbic network and cerebellum. The majority of the most discriminating anatomical connections were located within or across the cortical-limbic network and cerebellum, thereby indicating that these disease-related anatomical network alterations may give rise to a portion of the complex of emotional and memory deficit between the left and right mTLE. Moreover, the orbitofrontal gyrus, cingulate cortex, hippocampus and parahippocampal gyrus, which exhibit high discriminative power in classification, may play critical roles in the pathophysiology of mTLE. The current study demonstrated that anatomical connectivity differences between the left mTLE and the right mTLE may have the potential to serve as a neuroimaging biomarker to guide personalized diagnosis of the left and right mTLE.

  2. Spatial and temporal patterns of micropollutants in streams and effluent of 24 WWTPs across Switzerland

    Science.gov (United States)

    Schönenberger, Urs; Spycher, Barbara; Kistler, David; Burdon, Frank; Reyes, Marta; Eggen, Rik; Joss, Adriano; Singer, Heinz; Stamm, Christian

    2016-04-01

    Treated municipal wastewater is an important source of micropollutants entering the environment. Micropollutants are a diverse range of chemicals of which concentrations vary strongly in space and time. To better quantitatively understand the spatio-temporal patterns of micropollutants in streams, we compared upstream and downstream locations at 24 wastewater treatment plants (WWTPs) across the Swiss Plateau and Jura regions. Each site represents the most upstream treatment plant in the corresponding catchment. In 2013, a broad analytical screening was applied to samples collected at 12 sites during winter (January) and summer conditions (June). Based in these results, the bi-monthly samples obtained in 2014 at 12 additional sites were analysed for a group of approximately 60 selected organic micropollutants. The screening results demonstrate that generally, pharmaceuticals, artificial sweeteners and corrosion inhibitors make up the largest share of the organic micropollutants in wastewater. Pesticides including biocides and plant protection products are also regularly found, but at lower concentrations. The opposite holds true for the concentration variability: pesticides vary the most across time and space, while pharmaceuticals exhibit more stable concentrations. Heavy metals fluctuate to a similar degree as pharmaceuticals. Principal component analyses suggest that pesticide and pharmaceutical levels at both upstream locations and in the wastewater vary independently of each other. At the upstream locations, the pesticide levels increased with the proportion of arable land in the watershed, whilst decreasing with greater cover of pasture and forest. Interestingly, the same patterns hold true for the composition of wastewater when considering land use in the catchments of the WWTPs. This suggests that pesticide-intensive agricultural crops not only impact surface water quality via diffuse pollution but also increase levels of pesticides in wastewater discharged

  3. Capturing spatial and temporal patterns of widespread, extreme flooding across Europe

    Science.gov (United States)

    Busby, Kathryn; Raven, Emma; Liu, Ye

    2013-04-01

    Statistical characterisation of physical hazards is an integral part of probabilistic catastrophe models used by the reinsurance industry to estimate losses from large scale events. Extreme flood events are not restricted by country boundaries which poses an issue for reinsurance companies as their exposures often extend beyond them. We discuss challenges and solutions that allow us to appropriately capture the spatial and temporal dependence of extreme hydrological events on a continental-scale, which in turn enables us to generate an industry-standard stochastic event set for estimating financial losses for widespread flooding. By presenting our event set methodology, we focus on explaining how extreme value theory (EVT) and dependence modelling are used to account for short, inconsistent hydrological data from different countries, and how to make appropriate statistical decisions that best characterise the nature of flooding across Europe. The consistency of input data is of vital importance when identifying historical flood patterns. Collating data from numerous sources inherently causes inconsistencies and we demonstrate our robust approach to assessing the data and refining it to compile a single consistent dataset. This dataset is then extrapolated using a parameterised EVT distribution to estimate extremes. Our method then captures the dependence of flood events across countries using an advanced multivariate extreme value model. Throughout, important statistical decisions are explored including: (1) distribution choice; (2) the threshold to apply for extracting extreme data points; (3) a regional analysis; (4) the definition of a flood event, which is often linked with reinsurance industry's hour's clause; and (5) handling of missing values. Finally, having modelled the historical patterns of flooding across Europe, we sample from this model to generate our stochastic event set comprising of thousands of events over thousands of years. We then briefly

  4. Convergence and divergence in the evolution of cat skulls: temporal and spatial patterns of morphological diversity.

    Directory of Open Access Journals (Sweden)

    Manabu Sakamoto

    applications in reconstructing temporal transitions across two-dimensional trait spaces, can be used in ecophenotypical and functional diversity studies, and may reveal novel patterns of morphospace occupation.

  5. Spatio-temporal expression patterns of Arabidopsis thaliana and Medicago truncatula defensin-like genes.

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    Mesfin Tesfaye

    Full Text Available Plant genomes contain several hundred defensin-like (DEFL genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species.

  6. Spatio-temporal expression patterns of Arabidopsis thaliana and Medicago truncatula defensin-like genes.

    Science.gov (United States)

    Tesfaye, Mesfin; Silverstein, Kevin At; Nallu, Sumitha; Wang, Lin; Botanga, Christopher J; Gomez, S Karen; Costa, Liliana M; Harrison, Maria J; Samac, Deborah A; Glazebrook, Jane; Katagiri, Fumiaki; Gutierrez-Marcos, Jose F; Vandenbosch, Kathryn A

    2013-01-01

    Plant genomes contain several hundred defensin-like (DEFL) genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species.

  7. Automated swimming activity monitor for examining temporal patterns of toxicant effects on individual Daphnia magna.

    Science.gov (United States)

    Bahrndorff, Simon; Michaelsen, Thomas Yssing; Jensen, Anne; Marcussen, Laurits Faarup; Nielsen, Majken Elley; Roslev, Peter

    2016-07-01

    Aquatic pollutants are often biologically active at low concentrations and impact on biota in combination with other abiotic stressors. Traditional toxicity tests may not detect these effects, and there is a need for sensitive high-throughput methods for detecting sublethal effects. We have evaluated an automated infra-red (IR) light-based monitor for recording the swimming activity of Daphnia magna to establish temporal patterns of toxicant effects on an individual level. Activity was recorded for 48 h and the sensitivity of the monitor was evaluated by exposing D. magna to the reference chemicals K2 Cr2 O7 at 15, 20 and 25 °C and 2,4-dichlorophenol at 20 °C. Significant effects (P swimming activity remained unchanged for 48 h at sublethal concentrations of K2 Cr2 O7 whereas activity at 20 and 25 °C was more biphasic with decreases in activity occurring after 12-18 h. A similar biphasic pattern was observed after 2,4-dichlorophenol exposure at 20 °C. EC50 values for 2,4-dichlorophenol and K2 Cr2 O7 determined from automated recording of swimming activity showed increasing toxicity with time corresponding to decreases in EC50 of 0.03-0.07 mg l(-1) h(-1) . EC50 values determined after 48 h were comparable or lower than EC50 values based on visual inspection according to ISO 6341. The results demonstrated that the swimming activity monitor is capable of detecting sublethal behavioural effects that are toxicant and temperature dependent. The method allows EC values to be established at different time points and can serve as a high-throughput screening tool in toxicity testing. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Temporal-Spatial Pattern of Carbon Stocks in Forest Ecosystems in Shaanxi, Northwest China.

    Directory of Open Access Journals (Sweden)

    Gaoyang Cui

    Full Text Available The precise and accurate quantitative evaluation of the temporal and spatial pattern of carbon (C storage in forest ecosystems is critical for understanding the role of forests in the global terrestrial C cycle and is essential for formulating forest management policies to combat climate change. In this study, we examined the C dynamics of forest ecosystems in Shaanxi, northwest China, based on four forest inventories (1989-1993, 1994-1998, 1999-2003, and 2004-2008 and field-sampling measurements (2012. The results indicate that the total C storage of forest ecosystems in Shaanxi increased by approximately 29.3%, from 611.72 Tg in 1993 to 790.75 Tg in 2008, partially as a result of ecological restoration projects. The spatial pattern of C storage in forest ecosystems mainly exhibited a latitude-zonal distribution across the province, increasing from north (high latitude to south (low latitude generally, which signifies the effect of environmental conditions, chiefly water and heat related factors, on forest growth and C sequestration. In addition, different data sources and estimation methods had a significant effect on the results obtained, with the C stocks in 2008 being considerably overestimated (864.55 Tg and slightly underestimated (778.07 Tg when measured using the mean C density method and integrated method, respectively. Overall, our results demonstrated that the forest ecosystem in Shaanxi acted as a C sink over the last few decades. However, further studies should be carried out with a focus on adaption of plants to environmental factors along with forest management for vegetation restoration to maximize the C sequestration potential and to better cope with climate change.

  9. Neuromolecular Imaging Shows Temporal Synchrony Patterns between Serotonin and Movement within Neuronal Motor Circuits in the Brain

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    Patricia A. Broderick

    2013-06-01

    Full Text Available The present discourse links the electrical and chemical properties of the brain with neurotransmitters and movement behaviors to further elucidate strategies to diagnose and treat brain disease. Neuromolecular imaging (NMI, based on electrochemical principles, is used to detect serotonin in nerve terminals (dorsal and ventral striata and somatodendrites (ventral tegmentum of reward/motor mesocorticolimbic and nigrostriatal brain circuits. Neuronal release of serotonin is detected at the same time and in the same animal, freely moving and unrestrained, while open-field behaviors are monitored via infrared photobeams. The purpose is to emphasize the unique ability of NMI and the BRODERICK PROBE® biosensors to empirically image a pattern of temporal synchrony, previously reported, for example, in Aplysia using central pattern generators (CPGs, serotonin and cerebral peptide-2. Temporal synchrony is reviewed within the context of the literature on central pattern generators, neurotransmitters and movement disorders. Specifically, temporal synchrony data are derived from studies on psychostimulant behavior with and without cocaine while at the same time and continuously, serotonin release in motor neurons within basal ganglia, is detected. The results show that temporal synchrony between the neurotransmitter, serotonin and natural movement occurs when the brain is NOT injured via, e.g., trauma, addictive drugs or psychiatric illness. In striking contrast, in the case of serotonin and cocaine-induced psychostimulant behavior, a different form of synchrony and also asynchrony can occur. Thus, the known dysfunctional movement behavior produced by cocaine may well be related to the loss of temporal synchrony, the loss of the ability to match serotonin in brain with motor activity. The empirical study of temporal synchrony patterns in humans and animals may be more relevant to the dynamics of motor circuits and movement behaviors than are studies of

  10. Temporal patterns of change in panic disorder during cognitive behaviour therapy: an Indian study.

    Science.gov (United States)

    Manjula, M; Prasadarao, P S D V; Kumaraiah, V; Raguram, R

    2014-09-01

    CBT has been proven to be effective in the treatment of panic disorder; however, attempts to study the process of change are limited. The study evaluated the temporal patterns of change in the panic symptoms, cognitions, behaviours, and anxiety sensitivity in subjects with panic disorder being treated with CBT. Thirty subjects with panic disorder were allocated to two groups: Cognitive Behaviour Therapy (CBT, n = 15) and Behaviour Therapy (BT, n = 15). Assessments were carried out weekly for five consecutive weeks using the Semi-Structured Interview Schedule, the Anxiety Sensitivity Index, the Agoraphobic Cognitions Questionnaire, and the Texas Panic Attack Record Form. The CBT group received comprehensive CBT and the BT group received psycho-education and Applied Relaxation. Following intervention the change was continuous and gradual on all the variables in the CBT group and the scores reduced to a functional range after 4-5 weeks of therapy. Such a change was not evident in the BT group. Significant change was evident in cognitive domains following the introduction of the exposure and cognitive restructuring within the CBT group. Both cognitive and behavioural techniques contributed to the overall change. CBT had an impact on the cognitive domains and significant changes were evident corresponding to the addition of cognitive restructuring and exposure techniques in the 3rd to 5th week. Both cognitive and behavioural components are therefore crucial for overall improvement to occur.

  11. Spatial and temporal patterns of debris flow deposition in the Oregon Coast Range, USA

    Science.gov (United States)

    May, Christine L.; Gresswell, Robert E.

    2004-01-01

    Patterns of debris-flow occurrence were investigated in 125 headwater basins in the Oregon Coast Range. Time since the previous debris-flows was established using dendrochronology, and recurrence interval estimates ranged from 98 to 357 years. Tributary basins with larger drainage areas had a greater abundance of potential landslide source areas and a greater frequency of scouring events compared to smaller basins. The flux rate of material delivered to the confluence with a larger river influenced the development of small-scale debris-flow fans. Fans at the mouths of tributary basins with smaller drainage areas had a higher likelihood of being eroded by the mainstem river in the interval between debris-flows, compared to bigger basins that had larger, more persistent fans. Valley floor width of the receiving channel also influenced fan development because it limited the space available to accommodate fan formation. Of 63 recent debris-flows, 52% delivered sediment and wood directly to the mainstem river, 30% were deposited on an existing fan before reaching the mainstem, and 18% were deposited within the confines of the tributary valley before reaching the confluence. Spatial variation in the location of past and present depositional surfaces indicated that sequential debris-flow deposits did not consistently form in the same place. Instead of being spatially deterministic, results of this study suggest that temporally variable and stochastic factors may be important for predicting the runout length of debris-flows.

  12. Multi-voxel pattern analysis of noun and verb differences in ventral temporal cortex.

    Science.gov (United States)

    Boylan, Christine; Trueswell, John C; Thompson-Schill, Sharon L

    2014-10-01

    Recent evidence suggests a probabilistic relationship exists between the phonological/orthographic form of a word and its lexical-syntactic category (specifically nouns vs. verbs) such that syntactic prediction may elicit form-based estimates in sensory cortex. We tested this hypothesis by conducting multi-voxel pattern analysis (MVPA) of fMRI data from early visual cortex (EVC), left ventral temporal (VT) cortex, and a subregion of the latter - the left mid fusiform gyrus (mid FG), sometimes called the "visual word form area." Crucially, we examined only those volumes sampled when subjects were predicting, but not viewing, nouns and verbs. This allowed us to investigate prediction effects in visual areas without any bottom-up orthographic input. We found that voxels in VT and mid FG, but not in EVC, were able to classify noun-predictive trials vs. verb-predictive trials in sentence contexts, suggesting that sentence-level predictions are sufficient to generate word form-based estimates in visual areas.

  13. Detection of temporal behaviour patterns of free-ranging cattle by means of diversity spectra

    Directory of Open Access Journals (Sweden)

    de Miguel, J. M.

    1991-06-01

    Full Text Available The aim of this paper is to detect temporal patterns of cattle behaviour. The method, diversity spectra, provides, on the one hand, the number of parts into which a temporary transect should be divided in order to understand the maximum segregation of cattle activities and, on the other, the clarity with which each segregation is defined. In the case under study (a 'dehesa' pasture-land in central Spain the maximum segregation of fundamental activities in cattle behaviour is reached by considering the year as divided into two periods: spring-summer and autumn-winter. Cattle behaviour shows an annual "coarse grain" pattern, which is associated with management activities and with the meteorological seasonality of the Mediterranean climate. However, within each of the two annual periods, maximum segregation is reached considering separately the days of observation. This "fine grain" pattern indicates within each season, a certain capacity for response to a fluctuating environment and determines very different behaviour on close days. During autumn-winter period cattle show seasonal and daily activity segregations which are clearer than during spring-summer. In the former period, the lack of grass, more severe climatic conditions and management would seem to be determining factors of this temporal behaviour pattern.

    [es] El objetivo del trabajo es identificar patrones temporales de comportamiento del ganado. El procedimiento utilizado, espectros de diversidad, permite apreciar, por un lado, el número de partes en que debe dividirse un transecto temporal para detectar la máxima segregación de las actividades del ganado y, por otro, el grado de definición con que se manifiesta dicha segregación. En el caso estudiado (una dehesa del centro de España la máxima segregación de las actividades fundamentales de comportamiento del ganado se produce al considerar el año dividido en dos periodos: primavera-verano y otoño-invierno. El

  14. We'll meet again: revealing distributional and temporal patterns of social contact.

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    Thorsten Pachur

    Full Text Available What are the dynamics and regularities underlying social contact, and how can contact with the people in one's social network be predicted? In order to characterize distributional and temporal patterns underlying contact probability, we asked 40 participants to keep a diary of their social contacts for 100 consecutive days. Using a memory framework previously used to study environmental regularities, we predicted that the probability of future contact would follow in systematic ways from the frequency, recency, and spacing of previous contact. The distribution of contact probability across the members of a person's social network was highly skewed, following an exponential function. As predicted, it emerged that future contact scaled linearly with frequency of past contact, proportionally to a power function with recency of past contact, and differentially according to the spacing of past contact. These relations emerged across different contact media and irrespective of whether the participant initiated or received contact. We discuss how the identification of these regularities might inspire more realistic analyses of behavior in social networks (e.g., attitude formation, cooperation.

  15. Patterns of spatial and temporal distribution of the asparagus miner (Diptera: Agromyzidae): implications for management.

    Science.gov (United States)

    Morrison, William R; Szendrei, Zsofia

    2013-06-01

    The asparagus miner is an obligatory feeder on asparagus and a putative vector for pathogenic fungi implicated in the early decline of asparagus fields. To date, the distribution of the asparagus miner over space and time is poorly understood. Our study evaluated the spatial and temporal pattern of adult asparagus miners in commercial asparagus fields in Michigan in 2011 and 2012. We sampled adults and damage weekly during the growing season using yellow sticky traps outside, at the edge, and inside commercial fields. Yellow sticky traps at each trapping location were placed at the canopy and ground level to determine vertical distribution of adults. During the first generation, adults were more evenly distributed throughout the field. In the second generation, adults were more commonly found on the edge of the field. Overall, there was a greater percent of mining damage near the edge of the field. Additionally, three times as many asparagus miners were found in the canopy compared with ground-level traps. There were 12 times as many asparagus miner adults on edges bordered by another asparagus field than on ones bordered by forest. Taken together, our results indicate that while asparagus miner management in the beginning of the growing season should focus on the entire field, in the latter half of the season, growers could save money and resources by targeting miner adults at the edges of fields. Finally, conserving the remaining naturally forested landscape and planting borders of trees may help ameliorate pest pressure in asparagus fields.

  16. Spatial Patterns and Temporal Variability of Drought in Beijing-Tianjin-Hebei Metropolitan Areas in China

    Directory of Open Access Journals (Sweden)

    Wanyuan Cai

    2015-01-01

    Full Text Available Drought identification and assessment are essential for regional water resources management. In this paper, the spatiotemporal characteristics of drought were evaluated based on monthly precipitation data from 33 synoptic stations during the period of 1960–2010. The percent of normal precipitation was applied to illustrate the driest years in Beijing-Tianjin-Hebei metropolitan areas (BTHMA (1965, 1997, and 2002. The modified Reconnaissance Drought Index (RDI was applied to capture the drought patterns and to estimate the drought severity at 33 meteorological stations. Agglomerative hierarchical cluster analysis (AHCA and principal component analysis (PCA were used to identify three different drought subregions R1, R2, and R3 based on the monthly precipitation values in BTHMA, which is located in southeast, north, and south of BTHMA, respectively. The year 1965 was the driest and 1964 was the wettest during the observed period. The characteristics of drought were analyzed in terms of the temporal evolution of the RDI-12 values and the frequency of drought for the three identified regions. The percentage of years characterized by drought was 13.73% for R1, 16.50% for R2, and 15.53% for R3. 66.91% of drought belongs to the near normal drought category. The obtained results can aid to improve water resources management in the area.

  17. Spatio-temporal cerebral blood flow perfusion patterns in cortical spreading depression

    Science.gov (United States)

    Verisokin, Andrey Yu.; Verveyko, Darya V.; Postnov, Dmitry E.

    2017-04-01

    Cortical spreading depression (CSD) is an example of one of the most common abnormalities in biophysical brain functioning. Despite the fact that there are many mathematical models describing the cortical spreading depression (CSD), most of them do not take into consideration the role of redistribution of cerebral blood flow (CBF), that results in the formation of spatio-temporal patterns. The paper presents a mathematical model, which successfully explains the CBD role in the CSD process. Numerical study of this model has revealed the formation of stationary dissipative structures, visually analogous to Turing structures. However, the mechanism of their formation is not diffusion. We show these structures occur due to another type of spatial coupling, that is related to tissue perfusion rate. The proposed model predicts that at similar state of neurons the distribution of blood flow and oxygenation may by different. Currently, this effect is not taken into account when the Blood oxygen-level dependent (BOLD) contrast imaging used in functional magnetic resonance imaging (fMRI). Thus, the diagnosis on the BOLD signal can be ambiguous. We believe that our results can be used in the future for a more correct interpretation of the data obtained with fMRI, NIRS and other similar methods for research of the brain activity.

  18. Temporal patterns of infiltration into a water repellent soil under field conditions

    Science.gov (United States)

    Ward, Phil; Roper, Margaret; Micin, Shayne; Jongepier, Ramona

    2014-05-01

    Water repellency causes substantial economic losses for farmers in southern Australia through impacts on crop growth and weed germination. However, recent research has demonstrated that laboratory measurements of water repellency may not be a reliable indicator of the severity of symptoms experienced in the field. In particular, crop residue retention and minimal soil disturbance led to increased water repellency, but was also associated with higher soil water contents measured at strategic times of the year. Little is known about the temporal patterns of soil water storage close to the soil surface in a water repellent sand. In this research we measured soil water content at a depth of 0.05 m at 15-minute intervals from June 2011 to October 2012, under various treatment combinations of residue retention and soil disturbance. Measurements were made in both 'crop row' and 'crop inter-row' positions. For a rainfall event (9.2 mm) in March 2012, prior to crop seeding, plots previously established with no-till absorbed significantly more water (increase in soil water content of 0.074 v/v) than plots conventionally cultivated (0.038 v/v). In June 2012 (12.6 mm), 4 weeks after crop seeding, tillage was again significant, and there was a significant interaction between tillage and 'row' or 'inter-row' position. These results demonstrate the importance of crop management in modifying the response of water repellent soils to rainfall in the field.

  19. Synthesis of US Public Water Supply: Spatio-temporal Patterns and Socio-Economic Controls

    Science.gov (United States)

    Arumugam, S.; Sabo, J. L.; Larson, K.; Sinha, T.; Seo, S. B.; Das Bhowmik, R.; Ruhi, A.

    2016-12-01

    Recent USGS water use report suggest that continuously water-use efficiency could mitigate the supply-and-demand imbalance arising from changing climate and growing population. However, this rich data have not been analyzed to understand the underlying spatio-temporal patterns in public supply water use, nor have been investigated to identify the factors contributing to this increased water-use efficiency. A national-scale synthesis of public supply withdrawals ("withdrawals") reveals a strong North-South gradient in public supply water use with the increased population in the US Sunbelt contributing to the increased withdrawal over the South. In contrast, a reverse South-North gradient exists in and per-capita withdrawals ("efficiency"), with northern states consistently improving the efficiency, while the southern states' efficiency declined. Analysis on the role of socio-economic indicators reveals that efficiency has improved in urban counties relative to rural ones, and in counties with higher income and education. We argue that there is a critical need for monthly-to-annual updating of the USGS water-use data for identifying effective strategies that control the water-use efficiency in various geographic settings under a changing climate.

  20. Similarity between Spatial-temporal Expression Patterning of HOXA11 and Progesterone Receptor in Human Endometrium

    Institute of Scientific and Technical Information of China (English)

    Li-fen WANG; Hong-zhi LUO; Zheng-mei ZHU; Jie-dong WANG

    2003-01-01

    Objective To study HOXAll expression and its correlation with that of the progesterone receptor(PR) gene in human endometriumMethods In situ hybridization and semi-quantitative RT-PCR were used.Results HOXA l l mRNA was detected in both stromal and glandular cells of normal endometrium bv in situ hybridization. But the expression levels in the glandular cells had a dramatic decline or even disappearance at mid-secretory stage.Semi-quantitative RT-PCR analysis, however, demonstrated that the total expression levels of HOXAll mRNA were markedly increased in the mid-secretory endometrium, which suggested that there was an increased expression in stromal cells. Similar results were obtained for PR gene expression in human endometrium by in situ hybridization and semi-quantitative RT-PCR analysis.Conclusion HOXAll gene spatial and temporal expression patterns were similar to that of PR gene in endometrium across menstrual cycle, and HOXA l l was closely related to the endometrial proltferation and differentiation during menstrual cycle, especially the establishment of receptive status in implantation.

  1. Spatial and temporal patterns of nasopharyngeal carcinoma mortality in China, 1973-2005.

    Science.gov (United States)

    Xia, Changfa; Yu, Xue Qin; Zheng, Rongshou; Zhang, Siwei; Zeng, Hongmei; Wang, Jinfeng; Liao, Yilan; Zou, Xiaonong; Zuo, Tingting; Yang, Zhixun; Chen, Wanqing

    2017-08-10

    We fitted generalized linear models using data from three national retrospective surveys on cause of death in China to explore the spatial and temporal patterns of nasopharyngeal carcinoma (NPC) mortality over the period 1973 to 2005. The results suggest that there was a significant decrease in NPC mortality in China over time (p China areas have an elevated risk of mortality from NPC compared to those living in North China across all three time periods, with the RR being 4.96 (95% CI: 4.31-5.70) in 1973-1975, 12.83 (95% CI: 10.73-15.34) in 1990-1992 and 15.20 (95% CI: 12.34-18.72) in 2004-2005. Although NPC mortality in most areas of China has reduced to very low levels, the widening geographical disparities in NPC mortality are still noteworthy. It may be necessary to target public health policies to address the widening geographical disparities in NPC mortality. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Enhancing the usage pattern mining performance with temporal segmentation of QPop Increment in digital libraries

    Institute of Scientific and Technical Information of China (English)

    CAO San-xing; KLEIN R.Rody; LIU Jian-bo

    2005-01-01

    The convergence of next-generation Networks and the emergence of new media systems have made media-rich digital libraries popular in application and research. The discovery of media content objects' usage patterns, where QPop Increment is the characteristic feature under study, is the basis of intelligent data migration scheduling, the very key issue for these systems to manage effectively the massive storage facilities in their backbones. In this paper, a clustering algorithm is established, on the basis of temporal segmentation of QPop Increment, so as to improve the mining performance. We employed the standard C-Means algorithm as the clustering kernel, and carried out the experimental mining process with segmented QPop Increases obtained in actual applications. The results indicated that the improved algorithm is more advantageous than the basic one in important indices such as the clustering cohesion. The experimental study in this paper is based on a Media Assets Library prototype developed for the use of the advertainment movie production project for Olympics 2008, under the support of both the Humanistic Olympics Study Center in Beijing, and China State Administration of Radio, Film and TV.

  3. Spatial and temporal fish diversity patterns from Santa Catarina Island, Brazil

    Directory of Open Access Journals (Sweden)

    André Cattani

    2015-11-01

    Full Text Available The Santa Catarina Island has a mosaic of ecosystems, with great importance for the fishes. There is the presence of estuaries, lagoons, mangroves and sandy beaches in the same island. Thus, the objectives of this study were to evaluate the spatio and temporal fish diversity patterns in estuaries, lagoons and beach systems of Santa Catarina Island, Santa Catarina, Brazil. Fish data collected between 1983 to 2011 in the baía Norte, saco dos Limões, Itacorubi and Ratones mangroves, Conceição lagoon and Índio beach was analyzed. Fish were sampled with different gear techniques. In the North Bay and saco dos Limões individuals were caught by trawl, but in the mangroves and lagoon were used gillnets, cast nets and dip nets. In the Índio beach the fishes were collected using fyke nets. For each local, species accumulation curves were plotted to compare the observed pattern with modelled data, using first order Jackknife estimator. Species richness differences among locals and seasons were tested using PERMANOVA, followed by a canonical analysis of principal coordinates (CAP. To assess the taxonomic structures at each location, the average taxonomic distinctness (AvTD and the variation in taxonomic distinctness (VarTD were also used. Higher average species richness was found in the saco dos Limões (mean ± SE; 59.8 ± 2.5, followed by Índio Beach (55.7 ± 2.7, Conceição lagoon (52.3 ± 6.4, North bay (45.0 ± 2.5, mangrove Itacorubi (34.5 ± 3.2 and mangrove Ratones (30.8 ± 3.8. No significate differences for the taxonomic patterns were observed between seasons. Furthermore the hereby data suggest that the fish assemblages of the inner portion of the island of Santa Catarina are mainly formed by estuarine and marine fish, but differing in species richness among locals.

  4. Temporal Patterns of Larval Fish Occurrence in a Large Subtropical River.

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    Fangmin Shuai

    Full Text Available Knowledge of temporal patterns of larval fish occurrence is limited in south China, despite its ecological importance. This research examines the annual and seasonal patterns of fish larval presence in the large subtropical Pearl River. Data is based on samples collected every two days, from 2006 to 2013. In total, 45 taxa representing 13 families and eight orders were sampled. The dominant larval family was Cyprinidae, accounting for 27 taxa. Squaliobarbus curriculus was the most abundant species, followed by Megalobrama terminalis, Xenocypris davidi, Cirrhinus molitorella, Hemiculter leuscisculus and Squalidus argentatus. Fish larvae abundances varied significantly throughout the seasons (multivariate analyses: Cluster, SIMPROF and ANOSIM. The greatest numbers occurred between May and September, peaking from June through August, which corresponds to the reproductive season. In this study, redundancy analysis was used to describe the relationship between fish larval abundance and associated environmental factors. Mean water temperature, river discharge, atmospheric pressure, maximum temperature and precipitation play important roles in larval occurrence patterns. According to seasonal variations, fish larvae occurrence is mainly affected by water temperature. It was also noted that the occurrence of Salanx reevesii and Cyprinus carpio larvae is associated with higher dissolved oxygen (DO concentrations, higher atmospheric pressure and lower water temperatures which occur in the spring. On the other hand, M. terminalis, X. davidi, and C. molitorella are associated with high precipitation, high river discharge, low atmospheric pressure and low DO concentrations which featured during the summer months. S. curriculus also peaks in the summer and is associated with peak water temperatures and minimum NH3-N concentrations. Rhinogobius giurinus occur when higher atmospheric pressure, lower precipitation and lower river discharges occur in the autumn

  5. Discovering temporal patterns in water quality time series, focusing on floods with the LDA method

    Science.gov (United States)

    Hélène Aubert, Alice; Tavenard, Romain; Emonet, Rémi; Malinowski, Simon; Guyet, Thomas; Quiniou, René; Odobez, Jean-Marc; Gascuel-Odoux, Chantal

    2013-04-01

    Studying floods has been a major issue in hydrological research for years. It is often done in terms of water quantity but it is also of interest in terms of water quality. Stream chemistry is a mix of solutes. They originate from various sources in the catchment, reach the stream by various flow pathways and are transformed by biogeochemical reactions at different locations. Therefore, we hypothesized that reaction of the stream chemistry to a rainfall event is not unique but varies according to the season (1), and the global meteorological conditions of the year (2). Identifying a typology of temporal chemical patterns of reaction to a rainfall event is a way to better understand catchment processes at the flood time scale. To answer this issue, we applied a probabilistic model (Latent Dirichlet Allocation or LDA (3)) mining recurrent sequential patterns to a dataset of floods. The dataset is 12 years long and daily recorded. It gathers a broad range of parameters from which we selected rainfall, discharge, water table depth, temperature as well as nitrate, dissolved organic carbon, sulphate and chloride concentrations. It comes from a long-term hydrological observatory (AgrHys, western France) located at Kervidy-Naizin. A set of 472 floods was automatically extracted (4). From each flood, a document has been generated that is made of a set of "hydrological words". Each hydrological word corresponds to a measurement: it is a triplet made of the considered variable, the time at which the measurement is made (relative to the beginning of the flood), and its magnitude (that can be low, medium or high). The documents are used as input data to the LDA algorithm. LDA relies on spotting co-occurrences (as an alternative to the more traditional study of correlation) between words that appear within the flood documents. It has two nice properties that are its ability to easily deal with missing data and its additive property that allows a document to be seen as a mixture

  6. Rich do not rise early: spatio-temporal patterns in the mobility networks of different socio-economic classes

    Science.gov (United States)

    Lotero, Laura; Hurtado, Rafael G.; Floría, Luis Mario; Gómez-Gardeñes, Jesús

    2016-10-01

    We analyse the urban mobility in the cities of Medellín and Manizales (Colombia). Each city is represented by six mobility networks, each one encoding the origin-destination trips performed by a subset of the population corresponding to a particular socio-economic status. The nodes of each network are the different urban locations whereas links account for the existence of a trip between two different areas of the city. We study the main structural properties of these mobility networks by focusing on their spatio-temporal patterns. Our goal is to relate these patterns with the partition into six socio-economic compartments of these two societies. Our results show that spatial and temporal patterns vary across these socio-economic groups. In particular, the two datasets show that as wealth increases the early-morning activity is delayed, the midday peak becomes smoother and the spatial distribution of trips becomes more localized.

  7. Geospatial and temporal patterns of annual cholera outbreaks in Matlab, Bangladesh

    Science.gov (United States)

    Majumder, M. S.; de Klerk, K.; Meyers, D.

    2012-12-01

    Cholera is a waterborne diarrheal disease endemic to Bangladesh, resulting in 1 million diagnoses annually. Such disease burden results in incalculable lost wages and treatment expenses, taken from the pockets of an already impoverished society. Two seasonally correlated outbreaks of cholera occur in Bangladesh every year. In the spring and early summer, the Bay of Bengal - which serves as a natural reservoir for the cholera bacteria - flows inland, causing the first outbreak amongst coastal communities. Waste containing the cholera bacteria enters the sewage system and remains untreated due to poor water and sanitation infrastructure. Therefore, during the following monsoon season, flooding of cholera-contaminated sewage into drinking water sources results in a second outbreak. Though considered common knowledge among local populations, this geographic and temporal progression has not been empirically verified in the current literature. The aim of our ongoing study is to systematically analyze the seasonal trajectory of endemic cholera in Bangladesh. This paper discusses the results obtained from a comprehensive survey of available cholera data from the International Centre of Diarrheal Disease Research, Bangladesh (ICDDR,B) in Matlab, Bangladesh. Matlab thana is a near-coastal community that consists of 142 villages. Monsoon season takes place from June through October. Due to its proximity to the Meghna River, which opens into the Bay of Bengal, the area experiences significant flooding during these months. Using 10 years of geographically referenced cholera data, cases were plotted in time and space. Preliminary patterns suggest that villages closer to the Meghna River experience the majority of the area's cholera outbreaks and that case count is highest in late spring and late fall. April/May and November/December represent 25% and 23% of total annual case counts respectively. Moreover, villages further from the coastline demonstrate 57% higher relative

  8. Spatial-temporal patterns in Mediterranean carnivore road casualties: Consequences for mitigation

    Science.gov (United States)

    Grilo, C.; Bissonette, J.A.; Santos-Reis, M.

    2009-01-01

    Many carnivores have been seriously impacted by the expansion of transportation systems and networks; however we know little about carnivore response to the extent and magnitude of road mortality, or which age classes may be disproportionately impacted. Recent research has demonstrated that wildlife-vehicle-collisions (WVC) involving carnivores are modulated by temporal and spatial factors. Thus, we investigated road mortality on a guild of small and medium-sized carnivores in southern Portugal using road-kill data obtained from a systematic 36 months monitoring period along highways (260 km) and national roads (314 km) by addressing the following questions: (a) which species and age class are most vulnerable to WVC? (b) are there temporal and/or spatial patterns in road-kill? and (c) which life-history and/or spatial factors influence the likelihood of collisions? We recorded a total of 806 carnivore casualties, which represented an average of 47 ind./100 km/year. Red fox and stone marten had the highest mortality rates. Our findings highlight three key messages: (1) the majority of road-killed individuals were adults of common species; (2) all carnivores, except genets, were more vulnerable during specific life-history phenological periods: higher casualties were observed when red fox and stone marten were provisioning young, Eurasian badger casualties occurred more frequently during dispersal, and higher Egyptian mongoose mortality occurred during the breeding period; and (3) modeling demonstrated that favorable habitat, curves in the road, and low human disturbance were major contributors to the deadliest road segments. Red fox carcasses were more likely to be found on road sections with passages distant from urban areas. Conversely, stone marten mortalities were found more often on national roads with high of cork oak woodland cover; Egyptian mongoose and genet road-kills were found more often on road segments close to curves. Based on our results, two key

  9. Spatial and temporal patterns in oxygen and nutrient fluxes in sediment of German Bight (North Sea)

    Science.gov (United States)

    Neumann, Andreas; Friedrich, Jana; van Beusekom, Justus; Naderipour, Céline

    2016-04-01

    The German Bight in the southern North Sea is affected by intensive anthropogenic exploitation. Over a century of intensive use by shipping, fishery, and input by polluted rivers has pushed the coastal ecosystem far from its pristine state. The nutrient load reached a maximum in the early 1990s (Amann et al. 2012), and implementation of environmental protection policies substantially decreased the riverine nutrient load. While the riverine input of pollutants has constantly reduced since then, new forms of sea exploitation emerge. The most noticeable example is the installation of more than 600 wind turbines over the past few years in the German EEZ, and additionally 1,200 are already planned. The impact of these installations on hydrology and biogeochemical cycles is largely unclear. In a series of monitoring cruises we repeatedly sampled the sediment at a set of monitoring stations, which represent all typical habitats of the German Bight. We deployed benthic landers for in-situ chamber incubations and performed ex-situ whole-core incubations to investigate the benthic fluxes of oxygen and nutrients, and their spatial and temporal variability. Our first results indicate that benthic nutrient recycling is more intense during summer than during winter, which suggests that biological processes contribute substantially to the recycling of nutrients. The fluxes of reactive nitrogen appear lower than observations from 1992 (Lohse et al. 1993), when riverine N loads were at their maximum (Amann et al. 2012). The comparison of our recent measurements with observations from the past decades will enable us to assess the effect of decreasing nutrient discharge into the coastal North Sea. Our results will further set a baseline for elucidating the impact of the massive installation of wind turbines in the near future. This study contributes to the NOAH project (North Sea; Observation and Assessment of Habitats). References Amann T., A. Weiss, and J. Hartmann (2012): Carbon

  10. Soft computing analysis of the possible correlation between temporal and energy release patterns in seismic activity

    Science.gov (United States)

    Konstantaras, Anthony; Katsifarakis, Emmanouil; Artzouxaltzis, Xristos; Makris, John; Vallianatos, Filippos; Varley, Martin

    2010-05-01

    This paper is a preliminary investigation of the possible correlation of temporal and energy release patterns of seismic activity involving the preparation processes of consecutive sizeable seismic events [1,2]. The background idea is that during periods of low-level seismic activity, stress processes in the crust accumulate energy at the seismogenic area whilst larger seismic events act as a decongesting mechanism releasing considerable energy [3,4]. A dynamic algorithm is being developed aiming to identify and cluster pre- and post- seismic events to the main earthquake following on research carried out by Zubkov [5] and Dobrovolsky [6,7]. This clustering technique along with energy release equations dependent on Richter's scale [8,9] allow for an estimate to be drawn regarding the amount of the energy being released by the seismic sequence. The above approach is being implemented as a monitoring tool to investigate the behaviour of the underlying energy management system by introducing this information to various neural [10,11] and soft computing models [1,12,13,14]. The incorporation of intelligent systems aims towards the detection and simulation of the possible relationship between energy release patterns and time-intervals among consecutive sizeable earthquakes [1,15]. Anticipated successful training of the imported intelligent systems may result in a real-time, on-line processing methodology [1,16] capable to dynamically approximate the time-interval between the latest and the next forthcoming sizeable seismic event by monitoring the energy release process in a specific seismogenic area. Indexing terms: pattern recognition, long-term earthquake precursors, neural networks, soft computing, earthquake occurrence intervals References [1] Konstantaras A., Vallianatos F., Varley M.R. and Makris J. P.: ‘Soft computing modelling of seismicity in the southern Hellenic arc', IEEE Geoscience and Remote Sensing Letters, vol. 5 (3), pp. 323-327, 2008 [2] Eneva M. and

  11. Use of soil moisture dynamics and patterns at different spatio-temporal scales for the investigation of subsurface flow processes

    Directory of Open Access Journals (Sweden)

    T. Blume

    2009-07-01

    Full Text Available Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale and binary indicator maps (for the long-term and hillslope scale. Annual dynamics of soil moisture and decimeter-scale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a data-scarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to

  12. Mice lacking Sμ tandem repeats maintain RNA polymerase patterns but exhibit histone modification pattern shifts linked to class switch site locations.

    Science.gov (United States)

    Balter, Barbara B; Ciccone, David N; Oettinger, Marjorie A; Selsing, Erik

    2012-08-01

    Antibody switching involves class switch recombination (CSR) events between switch (S) regions located upstream of heavy chain constant (C) genes. Mechanisms targeting CSR to S-regions are not clear. Deletion of Sμ tandem repeat (SμTR) sequences causes CSR to shift into downstream regions that do not undergo CSR in WT B-cells, including the Cμ-region. We now find that, in SμTR(-/-) B cells, Sμ chromatin histone modification patterns also shift downstream relative to WT and coincide with SμTR(-/-) CSR locations. Our results suggest that histone H3 acetylation and methylation are involved in accessibility of switch regions and that these modifications are not dependent on the underlying sequence, but may be controlled by the location of upstream promoter or regulatory elements. Our studies also show RNA polymerase II (RNAPII) loading increases in the Eμ/Iμ region in stimulated B cells; these increases are independent of SμTR sequences. Longer Sμ deletions have been reported to eliminate increases in RNAPII density, therefore we suggest that sequences between Iμ and Sμ (possibly the Iμ splicing region as well as G-tracts that are involved in stable RNA:DNA complex formation during transcription) might control the RNAPII density increases.

  13. The use of satellite data for monitoring temporal and spatial patterns of fire: a comprehensive review

    Science.gov (United States)

    Lasaponara, R.

    2009-04-01

    Remotely sensed (RS) data can fruitfully support both research activities and operative monitoring of fire at different temporal and spatial scales with a synoptic view and cost effective technologies. "The contribution of remote sensing (RS) to forest fires may be grouped in three categories, according to the three phases of fire management: (i) risk estimation (before fire), (ii) detection (during fire) and (iii) assessment (after fire)" Chuvieco (2006). Relating each phase, wide research activities have been conducted over the years. (i) Risk estimation (before fire) has been mainly based on the use of RS data for (i) monitoring vegetation stress and assessing variations in vegetation moisture content, (ii) fuel type mapping, at different temporal and spatial scales from global, regional down to a local scale (using AVHRR, MODIS, TM, ASTER, Quickbird images and airborne hyperspectral and LIDAR data). Danger estimation has been mainly based on the use of AVHRR (onborad NOAA), MODIS (onboard TERRA and AQUA), VEGETATION (onboard SPOT) due to the technical characteristics (i.e. spectral, spatial and temporal resolution). Nevertheless microwave data have been also used for vegetation monitoring. (ii) Detection: identification of active fires, estimation of fire radiative energy and fire emission. AVHRR was one of the first satellite sensors used for setting up fire detection algorithms. The availbility of MODIS allowed us to obtain global fire products free downloaded from NASA web site. Sensors onboard geostationary satellite platforms, such as GOES, SEVIRI, have been used for fire detection, to obtain a high temporal resolution (at around 15 minutes) monitoring of active fires. (iii) Post fire damage assessment includes: burnt area mapping, fire emission, fire severity, vegetation recovery, fire resilience estimation, and, more recently, fire regime characterization. Chuvieco E. L. Giglio, C. Justice, 2008 Global charactrerization of fire activity: toward defining

  14. Characterization of clonal relatedness among the natural population of Staphylococcus aureus strains by using spa sequence typing and the BURP (based upon repeat patterns) algorithm

    NARCIS (Netherlands)

    Mellmann, Alexander; Weniger, Thomas; Berssenbrügge, Christoph; Keckevoet, Ursula; Friedrich, Alexander W; Harmsen, Dag; Grundmann, Hajo

    2008-01-01

    We evaluated the BURP (based upon repeat patterns) algorithm, which relies on sequencing of the Staphylococcus aureus protein A gene (spa), for its ability to infer clonal relatedness within a population of 110 wild-type strains. BURP clustering of the resulting 66 spa types was highly concordant wi

  15. Prospective study on the determinants of repeat attendance and attendance patterns in breast cancer screening using the Theory of Planned Behaviour

    NARCIS (Netherlands)

    Drossaert, C.H.C.; Boer, H.; Seydel, E.R.

    2003-01-01

    This prospective study, using the Theory of Planned Behaviour (TPB) as a theoretical framework, was carried out to identify the determinants of repeat attendance and attendance patterns in organised breast screening. A group of 2657 women filled out a baseline questionnaire, approximately 8 weeks af

  16. Identification of temporal patterns in the seismicity of Sumatra using Poisson Hidden Markov models

    Directory of Open Access Journals (Sweden)

    Katerina Orfanogiannaki

    2014-05-01

    Full Text Available On 26 December 2004 and 28 March 2005 two large earthquakes occurred between the Indo-Australian and the southeastern Eurasian plates with moment magnitudes Mw=9.1 and Mw=8.6, respectively. Complete data (mb≥4.2 of the post-1993 time interval have been used to apply Poisson Hidden Markov models (PHMMs for identifying temporal patterns in the time series of the two earthquake sequences. Each time series consists of earthquake counts, in given and constant time units, in the regions determined by the aftershock zones of the two mainshocks. In PHMMs each count is generated by one of m different Poisson processes that are called states. The series of states is unobserved and is in fact a Markov chain. The model incorporates a varying seismicity rate, it assigns a different rate to each state and it detects the changes on the rate over time. In PHMMs unobserved factors, related to the local properties of the region are considered affecting the earthquake occurrence rate. Estimation and interpretation of the unobserved sequence of states that underlie the data contribute to better understanding of the geophysical processes that take place in the region. We applied PHMMs to the time series of the two mainshocks and we estimated the unobserved sequences of states that underlie the data. The results obtained showed that the region of the 26 December 2004 earthquake was in state of low seismicity during almost the entire observation period. On the contrary, in the region of the 28 March 2005 earthquake the seismic activity is attributed to triggered seismicity, due to stress transfer from the region of the 2004 mainshock.

  17. Spatial and Temporal Patterns of Global NDVI Trends: Correlations with Climate and Human Factors

    Science.gov (United States)

    LIU, Y.; Li, S.

    2015-12-01

    Abstract: Changes in vegetation activity are driven by multiple natural and anthropogenic factors, which can be reflected by Normalized Difference Vegetation Index (NDVI) derived from satellite. In this paper, NDVI trends from 1982 to 2012 are first estimated by the Theil-Sen median slope method to explore their spatial and temporal patterns. Then the impact of climate variables and human activity on the observed NDVI trends is analyzed. Our results show on average NDVI increased by 0.46×10-3 per year from 1982 to 2012 globally with decadal variations. For most regions of the world, a greening (increasing) - browning(decreasing) - greening (G-B-G) trend is observed over the periods 1982-2004, 1995-2004, and 2005-2012, respectively. A positive partial correlation of NDVI and temperature is observed in the first period but it decreases and occasionally becomes negative in the following periods, especially in the Humid Temperate and Dry Domain Regions. This suggests a weakened effect of temperature on vegetation growth. Precipitation, on the other hand, is found to have a positive impact on the NDVI trend. This effect becomes stronger in the third period of 1995-2004, especially in the Dry Domain Region. Anthropogenic effects and human activities, derived here from the Human Footprint Dataset and the associated Human Influence Index (HII), have varied impacts on the magnitude (absolute value) of the NDVI trends across continents. Significant positive effects are found in Asia, Africa, and Europe, suggesting that intensive human activity could accelerate the change in NDVI and vegetation. A more accurate attribution of vegetation change to specific climatic and anthropogenic factors is instrumental to understand vegetation dynamics and requires further research.

  18. Systematic temporal patterns in the relationship between housing development and forest bird biodiversity.

    Science.gov (United States)

    Pidgeon, Anna M; Flather, Curtis H; Radeloff, Volker C; Lepczyk, Christopher A; Keuler, Nicholas S; Wood, Eric M; Stewart, Susan I; Hammer, Roger B

    2014-10-01

    As people encroach increasingly on natural areas, one question is how this affects avian biodiversity. The answer to this is partly scale-dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and housing development. We used linear regression to examine associations between forest bird species richness and housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, housing density increased continually over time. Across the conterminous United States, the association between bird species richness and housing density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as housing increased through time. In more recently developed ecoregions, where housing density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where housing density was highest, the association of housing density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2-phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low-density housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in housing density are associated with biodiversity losses. The long-term effect on biodiversity depends on the final housing density. This general pattern can help unify our understanding of the relationship

  19. Non-linear power law approach for spatial and temporal pattern analysis of salt marsh evolution

    Science.gov (United States)

    Taramelli, A.; Cornacchia, L.; Valentini, E.; Bozzeda, F.

    2013-11-01

    Many complex systems on the Earth surface show non-equilibrium fluctuations, often determining the spontaneous evolution towards a critical state. In this context salt marshes are characterized by complex patterns both in geomorphological and ecological features, which often appear to be strongly correlated. A striking feature in salt marshes is vegetation distribution, which can self-organize in patterns over time and space. Self-organized patchiness of vegetation can often give rise to power law relationships in the frequency distribution of patch sizes. In cases where the whole distribution does not follow a power law, the variance of scale in its tail may often be disregarded. To this end, the research aims at how changes in the main climatic and hydrodynamic variables may influence such non-linearity, and how numerical thresholds can describe this. Since it would be difficult to simultaneously monitor the presence and typology of vegetation and channel sinuosity through in situ data, and even harder to analyze them over medium to large time-space scales, remote sensing offers the ability to analyze the scale invariance of patchiness distributions. Here, we focus on a densely vegetated and channelized salt marsh (Scheldt estuary Belgium-the Netherlands) by means of the sub-pixel analysis on satellite images to calculate the non-linearity in the values of the power law exponents due to the variance of scale. The deviation from power laws represents stochastic conditions under climate drivers that can be hybridized on the basis of a fuzzy Bayesian generative algorithm. The results show that the hybrid approach is able to simulate the non-linearity inherent to the system and clearly show the existence of a link between the autocorrelation level of the target variable (i.e. size of vegetation patches), due to its self-organization properties, and the influence exerted on it by the external drivers (i.e. climate and hydrology). Considering the results of the

  20. Microscale spatio-temporal patterns of oxygen dynamics in permeable intertidal sediments (Skallingen, Denmark)

    DEFF Research Database (Denmark)

    Walpersdorf, Eva Christine; Andersen, Thorbjørn Joest; Elberling, Bo

    a range of spatial and temporal timescales are required to fully quantify the importance of such ecosystems for benthic autotrophic and heterotrophic activity, carbon mineralization and element cycling. Here, small scale spatio-temporal heterogeneity of oxygen (O2) dynamics (mm to cm, min to hours, day...

  1. Spatial and temporal patterns of airborne metal pollution: the value of low technology sampling to an environmental epidemiology study.

    Science.gov (United States)

    Gailey, F A; Lloyd, O L

    1993-06-18

    To investigate an epidemic of respiratory cancer in Armadale, central Scotland, its air pollution was studied. During a period of 18 months, low technology samplers were exposed at 47 sites in the town to monitor the local variations in contamination by atmospheric metals. The samplers were two types of lichen and two types of moss, one of each type being a transplant and the other an in situ sampler. Following each exposure, the comparability of the samplers' uptake and retention of the metals was assessed. The sources of the metals and the effects of environmental variables on the pollution patterns were investigated through statistical analyses of spatial and temporal trends in the data. The spatial patterns of the metals indicated the steel foundry in the town as the major source of most of the pollutants. The temporal patterns, although less statistically significant, suggested the pollution might have been affected by some meteorological factors and by the foundry's output, but not by the output of the other main industry in the town, i.e. a brickworks. The types of sampler showed a general similarity of pollution pattern, but with some differences which indicated that some types of sampler were more suitable than others for particular forms of survey. Low technology sampling can provide information about short-distance and short-term changes in the patterns of airborne pollution by metals, thereby assisting the interpretation of epidemiological patterns of respiratory disease.

  2. Multivariate temporal pattern analysis applied to the study of rat behavior in the elevated plus maze: methodological and conceptual highlights.

    Science.gov (United States)

    Casarrubea, M; Magnusson, M S; Roy, V; Arabo, A; Sorbera, F; Santangelo, A; Faulisi, F; Crescimanno, G

    2014-08-30

    Aim of this article is to illustrate the application of a multivariate approach known as t-pattern analysis in the study of rat behavior in elevated plus maze. By means of this multivariate approach, significant relationships among behavioral events in the course of time can be described. Both quantitative and t-pattern analyses were utilized to analyze data obtained from fifteen male Wistar rats following a trial 1-trial 2 protocol. In trial 2, in comparison with the initial exposure, mean occurrences of behavioral elements performed in protected zones of the maze showed a significant increase counterbalanced by a significant decrease of mean occurrences of behavioral elements in unprotected zones. Multivariate t-pattern analysis, in trial 1, revealed the presence of 134 t-patterns of different composition. In trial 2, the temporal structure of behavior become more simple, being present only 32 different t-patterns. Behavioral strings and stripes (i.e. graphical representation of each t-pattern onset) of all t-patterns were presented both for trial 1 and trial 2 as well. Finally, percent distributions in the three zones of the maze show a clear-cut increase of t-patterns in closed arm and a significant reduction in the remaining zones. Results show that previous experience deeply modifies the temporal structure of rat behavior in the elevated plus maze. In addition, this article, by highlighting several conceptual, methodological and illustrative aspects on the utilization of t-pattern analysis, could represent a useful background to employ such a refined approach in the study of rat behavior in elevated plus maze. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.Este estudio describe patrones de abundancia temporal y espacial de larvas de

  4. Spatial and temporal patterns of land surface fluxes from remotely sensed surface temperatures within an uncertainty modelling framework

    Directory of Open Access Journals (Sweden)

    M. F. McCabe

    2005-01-01

    Full Text Available Characterising the development of evapotranspiration through time is a difficult task, particularly when utilising remote sensing data, because retrieved information is often spatially dense, but temporally sparse. Techniques to expand these essentially instantaneous measures are not only limited, they are restricted by the general paucity of information describing the spatial distribution and temporal evolution of evaporative patterns. In a novel approach, temporal changes in land surface temperatures, derived from NOAA-AVHRR imagery and a generalised split-window algorithm, are used as a calibration variable in a simple land surface scheme (TOPUP and combined within the Generalised Likelihood Uncertainty Estimation (GLUE methodology to provide estimates of areal evapotranspiration at the pixel scale. Such an approach offers an innovative means of transcending the patch or landscape scale of SVAT type models, to spatially distributed estimates of model output. The resulting spatial and temporal patterns of land surface fluxes and surface resistance are used to more fully understand the hydro-ecological trends observed across a study catchment in eastern Australia. The modelling approach is assessed by comparing predicted cumulative evapotranspiration values with surface fluxes determined from Bowen ratio systems and using auxiliary information such as in-situ soil moisture measurements and depth to groundwater to corroborate observed responses.

  5. Multiagent-Based Simulation of Temporal-Spatial Characteristics of Activity-Travel Patterns Using Interactive Reinforcement Learning

    Directory of Open Access Journals (Sweden)

    Min Yang

    2014-01-01

    Full Text Available We propose a multiagent-based reinforcement learning algorithm, in which the interactions between travelers and the environment are considered to simulate temporal-spatial characteristics of activity-travel patterns in a city. Road congestion degree is added to the reinforcement learning algorithm as a medium that passes the influence of one traveler’s decision to others. Meanwhile, the agents used in the algorithm are initialized from typical activity patterns extracted from the travel survey diary data of Shangyu city in China. In the simulation, both macroscopic activity-travel characteristics such as traffic flow spatial-temporal distribution and microscopic characteristics such as activity-travel schedules of each agent are obtained. Comparing the simulation results with the survey data, we find that deviation of the peak-hour traffic flow is less than 5%, while the correlation of the simulated versus survey location choice distribution is over 0.9.

  6. MBD3 expression and DNA binding patterns are altered in a rat model of temporal lobe epilepsy

    OpenAIRE

    Joanna Bednarczyk; Dębski, Konrad J.; Anna M. Bot; Katarzyna Lukasiuk

    2016-01-01

    The aim of the present study was to examine involvement of MBD3 (methyl-CpG-binding domain protein 3), a protein involved in reading DNA methylation patterns, in epileptogenesis and epilepsy. We used a well-characterized rat model of temporal lobe epilepsy that is triggered by status epilepticus, evoked by electrical stimulation of the amygdala. Stimulated and sham-operated animals were sacrificed 14 days after stimulation. We found that MBD3 transcript was present in neurons, oligodendrocyte...

  7. The temporal pattern of trading rule returns and central bank intervention: intervention does not generate technical trading rule profits

    OpenAIRE

    Neely, Christopher J.

    2002-01-01

    This paper characterizes the temporal pattern of trading rule returns and official intervention for Australian, German, Swiss and U.S. data to investigate whether intervention generates technical trading rule profits. High frequency data show that abnormally high trading rule returns precede German, Swiss and U.S. intervention, disproving the hypothesis that intervention generates inefficiencies from which technical rules profit. Australian intervention precedes high trading rule returns, but...

  8. Temporal patterns in coral reef, seagrass and mangrove communities from Chengue bay CARICOMP site (Colombia): 1993-2008

    OpenAIRE

    2015-01-01

    Few monitoring programs have simultaneously assessed the dynamics of linked marine ecosystems (coral reefs, seagrass beds and mangroves) to document their temporal and spatial variability. Based on CARICOMP protocol we evaluated permanent stations in coral reefs, seagrass beds and mangroves from 1993 to 2008 in Chengue Bay at the Tayrona Natural Park, Colombian Caribbean. Overall, the studied ecosystems showed a remarkable stability pattern over the monitoring period. While there were annual ...

  9. T-pattern analysis for the study of temporal structure of animal and human behavior: a comprehensive review.

    Science.gov (United States)

    Casarrubea, M; Jonsson, G K; Faulisi, F; Sorbera, F; Di Giovanni, G; Benigno, A; Crescimanno, G; Magnusson, M S

    2015-01-15

    A basic tenet in the realm of modern behavioral sciences is that behavior consists of patterns in time. For this reason, investigations of behavior deal with sequences that are not easily perceivable by the unaided observer. This problem calls for improved means of detection, data handling and analysis. This review focuses on the analysis of the temporal structure of behavior carried out by means of a multivariate approach known as T-pattern analysis. Using this technique, recurring sequences of behavioral events, usually hard to detect, can be unveiled and carefully described. T-pattern analysis has been successfully applied in the study of various aspects of human or animal behavior such as behavioral modifications in neuro-psychiatric diseases, route-tracing stereotypy in mice, interaction between human subjects and animal or artificial agents, hormonal-behavioral interactions, patterns of behavior associated with emesis and, in our laboratories, exploration and anxiety-related behaviors in rodents. After describing the theory and concepts of T-pattern analysis, this review will focus on the application of the analysis to the study of the temporal characteristics of behavior in different species from rodents to human beings. This work could represent a useful background for researchers who intend to employ such a refined multivariate approach to the study of behavior.

  10. Temporal development of coastal ecosystems in the Baltic Sea - an assessment of patterns and trends

    DEFF Research Database (Denmark)

    Olsson, Jens; Bergström, Lena; Tomczak, Maciej;

    2014-01-01

    Coastal areas are amongst the most biologically productive aquatic systems worldwide, but face strong and varaible anthropogenic pressures. Many marine ecosystems worlwide has gone through substantial structural changes during recent decades, but few studies have addressed the temporal developmen...

  11. Spatio-Temporal Patterns of Demyelination and Remyelination in the Cuprizone Mouse Model.

    Directory of Open Access Journals (Sweden)

    Ian Tagge

    Full Text Available Cuprizone administration in mice provides a reproducible model of demyelination and spontaneous remyelination, and has been useful in understanding important aspects of human disease, including multiple sclerosis. In this study, we apply high spatial resolution quantitative MRI techniques to establish the spatio-temporal patterns of acute demyelination in C57BL/6 mice after 6 weeks of cuprizone administration, and subsequent remyelination after 6 weeks of post-cuprizone recovery. MRI measurements were complemented with Black Gold II stain for myelin and immunohistochemical stains for associated tissue changes. Gene expression was evaluated using the Allen Gene Expression Atlas. Twenty-five C57BL/6 male mice were split into control and cuprizone groups; MRI data were obtained at baseline, after 6 weeks of cuprizone, and 6 weeks post-cuprizone. High-resolution (100 μm isotropic whole-brain coverage magnetization transfer ratio (MTR parametric maps demonstrated concurrent caudal-to-rostral and medial-to-lateral gradients of MTR decrease within corpus callosum (CC that correlated well with demyelination assessed histologically. Our results show that demyelination was not limited to the midsagittal line of the corpus callosum, and also that opposing gradients of demyelination occur in the lateral and medial CC. T2-weighted MRI gray/white matter contrast was strong at baseline, weak after 6 weeks of cuprizone treatment, and returned to a limited extent after recovery. MTR decreases during demyelination were observed throughout the brain, most clearly in callosal white matter. Myelin damage and repair appear to be influenced by proximity to oligodendrocyte progenitor cell populations and exhibit an inverse correlation with myelin basic protein gene expression. These findings suggest that susceptibility to injury and ability to repair vary across the brain, and whole-brain analysis is necessary to accurately characterize this model. Whole

  12. Temporal patterns of broad isoform expression during the development of neuronal lineages in Drosophila

    Directory of Open Access Journals (Sweden)

    Williams Darren W

    2009-11-01

    Full Text Available Abstract Background During the development of the central nervous system (CNS of Drosophila, neuronal stem cells, the neuroblasts (NBs, first generate a set of highly diverse neurons, the primary neurons that mature to control larval behavior, and then more homogeneous sets of neurons that show delayed maturation and are primarily used in the adult. These latter, 'secondary' neurons show a complex pattern of expression of broad, which encodes a transcription factor usually associated with metamorphosis, where it acts as a key regulator in the transitions from larva and pupa. Results The Broad-Z3 (Br-Z3 isoform appears transiently in most central neurons during embryogenesis, but persists in a subset of these cells through most of larval growth. Some of the latter are embryonic-born secondary neurons, whose development is arrested until the start of metamorphosis. However, the vast bulk of the secondary neurons are generated during larval growth and bromodeoxyuridine incorporation shows that they begin expressing Br-Z3 about 7 hours after their birth, approximately the time that they have finished outgrowth to their initial targets. By the start of metamorphosis, the oldest secondary neurons have turned off Br-Z3 expression, while the remainder, with the exception of the very youngest, maintain Br-Z3 while they are interacting with potential partners in preparation for neurite elaboration. That Br-Z3 may be involved in early sprouting is suggested by ectopically expressing this isoform in remodeling primary neurons, which do not normally express Br-Z3. These cells now sprout into ectopic locations. The expression of Br-Z3 is transient and seen in all interneurons, but two other isoforms, Br-Z4 and Br-Z1, show a more selective expression. Analysis of MARCM clones shows that the Br-Z4 isoform is expressed by neurons in virtually all lineages, but only in those cells born during a window during the transition from the second to the third larval

  13. Patterns of venom production and temporal polyethism in workers of Jerdon's jumping ant, Harpegnathos saltator.

    Science.gov (United States)

    Haight, Kevin L

    2012-12-01

    Ants are chemical factories, and among their more noticeable products are their venoms. Though many studies have addressed the properties and activities of ant venoms, basic venom-related physiological questions, such as how venom production and replacement may vary with age, are rarely addressed. The answers to these questions are fundamental to understanding the physiological capabilities of these organisms, as well as the parameters within which potential optimization of their investment in venom production must take place. The only previous investigation into venom production in ants found it to be limited to early life in workers of the fire ant, Solenopsis invicta (Haight and Tschinkel, 2003). Because similar studies have not been conducted for comparison, it is unclear whether or not this is a common physiological pattern in ants. As a parsimonious way to address this question, and, more generally, to increase the currently scant information available regarding the venom-producing capabilities of ants, the longevity, temporal polyethism, age-related venom production, and age-related venom replacement capabilities of workers of Jerdon's jumping ant, Harpegnathos saltator were investigated. Longevity varied from 10 days to nearly 2 years, with a median lifespan of 206 days. Workers remained in the nest when young, transitioned to outside work (foraging) after 50 days of age, and reached a plateau in their tendency to be outside the nest at 74 days of age. They eclosed with empty venom sacs, filled them by about 57 days of age, and were able to replace venom at all three ages tested (though at a higher rate when aged 100 days than 30 and 206). So, venom-production ability is not limited to early life in H. saltator workers, and aspects of venom physiology and exploratory behavior appear to coincide in a manner likely to result in foraging efficiency benefits; venom sacs reach fullness around the age workers begin their foraging careers, and venom replacement

  14. Spatio-temporal patterns and landscape-associated risk of Buruli ulcer in Akonolinga, Cameroon.

    Directory of Open Access Journals (Sweden)

    Jordi Landier

    2014-09-01

    Full Text Available Buruli ulcer (BU is an extensively damaging skin infection caused by Mycobacterium ulcerans, whose transmission mode is still unknown. The focal distribution of BU and the absence of interpersonal transmission suggest a major role of environmental factors, which remain unidentified. This study provides the first description of the spatio-temporal variations of BU in an endemic African region, in Akonolinga, Cameroon. We quantify landscape-associated risk of BU, and reveal local patterns of endemicity.From January 2002 to May 2012, 787 new BU cases were recorded in 154 villages of the district of Akonolinga. Incidence per village ranged from 0 (n = 59 villages to 10.4 cases/1000 person.years (py; median incidence was 0.4 cases/1,000 py. Villages neighbouring the Nyong River flood plain near Akonolinga town were identified as the highest risk zone using the SPODT algorithm. We found a decreasing risk with increasing distance to the Nyong and identified 4 time phases with changes in spatial distribution. We classified the villages into 8 groups according to landscape characteristics using principal component analysis and hierarchical clustering. We estimated the incidence ratio (IR associated with each landscape using a generalised linear model. BU risk was highest in landscapes with abundant wetlands, especially cultivated ones (IR = 15.7, 95% confidence interval [95%CI] = 15.7[4.2-59.2], and lowest in reference landscape where primary and secondary forest cover was abundant. In intermediate-risk landscapes, risk decreased with agriculture pressure (from IR[95%CI] = 7.9[2.2-28.8] to 2.0[0.6-6.6]. We identified landscapes where endemicity was stable and landscapes where incidence increased with time.Our study on the largest series of BU cases recorded in a single endemic region illustrates the local evolution of BU and identifies the Nyong River as the major driver of BU incidence. Local differences along the river are explained by wetland

  15. Spatio-temporal distribution patterns of the epibenthic community in the coastal waters of Suriname

    Science.gov (United States)

    Willems, Tomas; De Backer, Annelies; Wan Tong You, Kenneth; Vincx, Magda; Hostens, Kris

    2015-10-01

    This study aimed to characterize the spatio-temporal patterns of the epibenthic community in the coastal waters of Suriname. Data were collected on a (bi)monthly basis in 2012-2013 at 15 locations in the shallow (<40 m) coastal area, revealing three spatially distinct species assemblages, related to clear gradients in some environmental parameters. A species-poor coastal assemblage was discerned within the muddy, turbid-water zone (6-20 m depth), dominated by Atlantic seabob shrimp Xiphopenaeus kroyeri (Crustacea: Penaeoidea). Near the 30 m isobath, sediments were much coarser (median grain size on average 345±103 μm vs. 128±53 μm in the coastal assemblage) and water transparency was much higher (on average 7.6±3.5 m vs. 2.4±2.1 m in the coastal assemblage). In this zone, a diverse offshore assemblage was found, characterized by brittle stars (mainly Ophioderma brevispina and Ophiolepis elegans) and a variety of crabs, sea stars and hermit crabs. In between both zones, a transition assemblage was noted, with epibenthic species typically found in either the coastal or offshore assemblages, but mainly characterized by the absence of X. kroyeri. Although the epibenthic community was primarily structured in an on-offshore gradient related to depth, sediment grain size and sediment total organic carbon content, a longitudinal (west-east) gradient was apparent as well. The zones in the eastern part of the Suriname coastal shelf seemed to be more widely stretched along the on-offshore gradient. Although clear seasonal differences were noted in the environmental characteristics (e.g. dry vs. rainy season), this was not reflected in the epibenthic community structure. X. kroyeri reached very high densities (up to 1383 ind 1000 m-²) in the shallow coastal waters of Suriname. As X. kroyeri is increasingly exploited throughout its range, the current study provides the ecological context for its presence and abundance, which is crucial for an ecosystem approach and the

  16. Classification of River Basins by Recurrent Temporal Patterns of Storage and Runoff

    Science.gov (United States)

    Sayama, T.; Fernandez, R.

    2015-12-01

    Hydrological functions of river basins are summarized as collection, storage and runoff generation, which can be characterized by the dynamics of hydrological variables including precipitation, evaporation, storage and runoff. The temporal patterns of each variable can be indicators of the functionality of a basin. In this paper we introduce a measure to quantify the degree of similarity in intra-annual variations at monthly scale at different years for the four main variables. We introduce this measure under the term of recurrence and define it as the degree to which a monthly hydrological variable returns to the same state in subsequent years. The degree of recurrence in runoff is important not only for the management of water resources but also for the understanding of hydrologic processes, especially in terms of how the other three variables determine the recurrence in runoff. The main objective of this paper is to propose a simple hydrologic classification framework based on the combinations of recurrence in the four variables using a monthly scale time series. We evaluate it with lagged autocorrelation (AC), fast Fourier transforms (FFT) and Colwell's indices of variables. By setting a threshold to define high or low recurrence in the four variables, we classify each river basin into 16 possible classes. According to the river basin classification, 10 out of the 16 possible classes were present in the 35 largest river basins in the world. In the humid tropic region, the basins belong to a class with high recurrence in all the variables, while in the subtropical region many of the river basins have low recurrence. In the temperate region, the energy limited or water limited in summer characterizes the recurrence in storage, but runoff exhibits generally low recurrence due to the low recurrence in precipitation. Our proposed framework follows a simple methodology that can aid in grouping river basins with similar characteristics of water, energy and storage

  17. Effects of speed on temporal patterns in classical style and freestyle cross-country skiing.

    Science.gov (United States)

    Nilsson, Johnny; Tveit, Per; Eikrehagen, Olav

    2004-01-01

    The purpose was to study the adaptation to speed in the temporal patterns of the movement cycle and determine any differences in velocity, cycle rate and cycle length at the maximum speed level in the different classical style and freestyle cross-country skiing techniques. Eight skilled male cross-country skiers were filmed with a digital video camera in the sagittal plane while skiing on a flat cross-country ski track. The skiers performed three classical style techniques the diagonal stride, kick double poling and the double poling technique and four freestyle techniques paddle dance (gear 2), double dance (gear 3), single dance (gear 4) and combiskate (gear 5) at four different self-selected speed levels slow, medium, fast and their maximum. Cycle duration, cycle rate, cycle length, and relative and absolute cycle phase duration of the different techniques at the different speed levels were analysed by means of a video analysis system. The cycle rate in all tested classical and freestyle techniques was found to increase significantly (p skiing techniques. A minor, not significant, change in cycle length, and the significant increase in cycle rate with speed showed that the classical and freestyle cross-country skiing styles are dependent, to a large extent, on an increase in cycle rate for speed adaptation. A striking finding was the constant relative phase duration with speed, which indicates a simplified neural control of the speed adaptation in both cross-country skiing styles. For the practitioner, the knowledge about the importance of increasing cycle frequency rather than cycle length in the speed adaptation can be used to optimise a rapid increase in speed. The knowledge about the decrease in absolute phase duration, especially the thrust phase duration, points to the need for strength and technique training to enable force production at a high cycle rate and skiing speed. The knowledge that the relative phase duration stays constant with speed may be

  18. Spatial and temporal patterns of larval dispersal in a coral-reef fish metapopulation: evidence of variable reproductive success.

    Science.gov (United States)

    Pusack, Timothy J; Christie, Mark R; Johnson, Darren W; Stallings, Christopher D; Hixon, Mark A

    2014-07-01

    Many marine organisms can be transported hundreds of kilometres during their pelagic larval stage, yet little is known about spatial and temporal patterns of larval dispersal. Although traditional population-genetic tools can be applied to infer movement of larvae on an evolutionary timescale, large effective population sizes and high rates of gene flow present serious challenges to documenting dispersal patterns over shorter, ecologically relevant, timescales. Here, we address these challenges by combining direct parentage analysis and indirect genetic analyses over a 4-year period to document spatial and temporal patterns of larval dispersal in a common coral-reef fish: the bicolour damselfish (Stegastes partitus). At four island locations surrounding Exuma Sound, Bahamas, including a long-established marine reserve, we collected 3278 individuals and genotyped them at 10 microsatellite loci. Using Bayesian parentage analysis, we identified eight parent-offspring pairs, thereby directly documenting dispersal distances ranging from 0 km (i.e., self-recruitment) to 129 km (i.e., larval connectivity). Despite documenting substantial dispersal and gene flow between islands, we observed more self-recruitment events than expected if the larvae were drawn from a common, well-mixed pool (i.e., a completely open population). Additionally, we detected both spatial and temporal variation in signatures of sweepstakes and Wahlund effects. The high variance in reproductive success (i.e., 'sweepstakes') we observed may be influenced by seasonal mesoscale gyres present in the Exuma Sound, which play a prominent role in shaping local oceanographic patterns. This study documents the complex nature of larval dispersal in a coral-reef fish, and highlights the importance of sampling multiple cohorts and coupling both direct and indirect genetic methods in order disentangle patterns of dispersal, gene flow and variable reproductive success. © 2014 John Wiley & Sons Ltd.

  19. Variability in Regularity: Mining Temporal Mobility Patterns in London, Singapore and Beijing Using Smart-Card Data.

    Science.gov (United States)

    Zhong, Chen; Batty, Michael; Manley, Ed; Wang, Jiaqiu; Wang, Zijia; Chen, Feng; Schmitt, Gerhard

    2016-01-01

    To discover regularities in human mobility is of fundamental importance to our understanding of urban dynamics, and essential to city and transport planning, urban management and policymaking. Previous research has revealed universal regularities at mainly aggregated spatio-temporal scales but when we zoom into finer scales, considerable heterogeneity and diversity is observed instead. The fundamental question we address in this paper is at what scales are the regularities we detect stable, explicable, and sustainable. This paper thus proposes a basic measure of variability to assess the stability of such regularities focusing mainly on changes over a range of temporal scales. We demonstrate this by comparing regularities in the urban mobility patterns in three world cities, namely London, Singapore and Beijing using one-week of smart-card data. The results show that variations in regularity scale as non-linear functions of the temporal resolution, which we measure over a scale from 1 minute to 24 hours thus reflecting the diurnal cycle of human mobility. A particularly dramatic increase in variability occurs up to the temporal scale of about 15 minutes in all three cities and this implies that limits exist when we look forward or backward with respect to making short-term predictions. The degree of regularity varies in fact from city to city with Beijing and Singapore showing higher regularity in comparison to London across all temporal scales. A detailed discussion is provided, which relates the analysis to various characteristics of the three cities. In summary, this work contributes to a deeper understanding of regularities in patterns of transit use from variations in volumes of travellers entering subway stations, it establishes a generic analytical framework for comparative studies using urban mobility data, and it provides key points for the management of variability by policy-makers intent on for making the travel experience more amenable.

  20. Variability in Regularity: Mining Temporal Mobility Patterns in London, Singapore and Beijing Using Smart-Card Data.

    Directory of Open Access Journals (Sweden)

    Chen Zhong

    Full Text Available To discover regularities in human mobility is of fundamental importance to our understanding of urban dynamics, and essential to city and transport planning, urban management and policymaking. Previous research has revealed universal regularities at mainly aggregated spatio-temporal scales but when we zoom into finer scales, considerable heterogeneity and diversity is observed instead. The fundamental question we address in this paper is at what scales are the regularities we detect stable, explicable, and sustainable. This paper thus proposes a basic measure of variability to assess the stability of such regularities focusing mainly on changes over a range of temporal scales. We demonstrate this by comparing regularities in the urban mobility patterns in three world cities, namely London, Singapore and Beijing using one-week of smart-card data. The results show that variations in regularity scale as non-linear functions of the temporal resolution, which we measure over a scale from 1 minute to 24 hours thus reflecting the diurnal cycle of human mobility. A particularly dramatic increase in variability occurs up to the temporal scale of about 15 minutes in all three cities and this implies that limits exist when we look forward or backward with respect to making short-term predictions. The degree of regularity varies in fact from city to city with Beijing and Singapore showing higher regularity in comparison to London across all temporal scales. A detailed discussion is provided, which relates the analysis to various characteristics of the three cities. In summary, this work contributes to a deeper understanding of regularities in patterns of transit use from variations in volumes of travellers entering subway stations, it establishes a generic analytical framework for comparative studies using urban mobility data, and it provides key points for the management of variability by policy-makers intent on for making the travel experience more

  1. Temporal patterns in capture rate and sex ratio of forest bats in Arkansas

    Science.gov (United States)

    Roger W. Perry; S. Andrew Carter; Ronald E. Thill

    2010-01-01

    We quantified changes in capture rates and sex ratios from May to Sept. for eight species of bats, derived from 8 y of extensive mist netting in forests of the Ouachita Mountains, Arkansas. Our primary goal was to determine patterns of relative abundance for each species of bat captured over forest streams and to determine if these patterns were similar to patterns of...

  2. Composition, structural characteristics and temporal patterns of fish assemblages in non-tidal Mediterranean lagoons: A case study

    Science.gov (United States)

    Maci, S.; Basset, A.

    2009-08-01

    The importance of transitional water ecosystems as nursery habitats and feeding grounds for fish species is well-known. Detailed studies of colonization patterns of fish guilds in response to biotic and abiotic drivers are however unevenly distributed among ecosystem types. We address here the temporal variability of fish assemblages in small non-tidal lagoons in the Mediterranean basin. The study was carried out at the Acquatina lagoon (Lecce, Italy) where four stations, situated in two habitat types along a confinement gradient, were sampled twice per month for one year with fyke nets. Forty-five taxa ranging across 20 families were collected, with the most abundant species, Atherina boyeri, accounting for more than 95% of total abundance. Pooling all species together (excluding sand smelt), the structural features of the assemblage, relative abundance of families, and abundance of individual species all showed significant temporal patterns. Mean abundance peaked in Summer and Autumn and fell in Winter, whereas taxonomic richness and diversity were highest in Summer and lowest in Spring. Within the fish assemblage, multivariate ordination showed temporal segregation of species belonging to the same family or genus and expected to be functionally similar, suggesting that they avoid competition for space and resources by timing inward migration and peak occurrence differently. Of the environmental driving forces, which also showed temporal patterns of variation, salinity was the main factor affecting the distribution of individuals and species. The catch of young individuals of several marine species confirmed the role of this small lagoon as a nursery and feeding area, and emphasized the need for further studies.

  3. Spatio-temporal patterns of hazards and their use in risk assessment and mitigation. Case study of road accidents in Romania

    Science.gov (United States)

    Catalin Stanga, Iulian

    2013-04-01

    the spatial or temporal clustering of crash accidents. Since the 1990's, Geographical Informational Systems (GIS) became a very important tool for traffic and road safety management, allowing not only the spatial and multifactorial analysis, but also graphical and non-graphical outputs. The current paper presents an accessible GIS methodology to study the spatio-temporal pattern of injury related road accidents, to identify the high density accidents zones, to make a cluster analysis, to create multicriterial typologies, to identify spatial and temporal similarities and to explain them. In this purpose, a Geographical Information System was created, allowing a complex analysis that involves not only the events, but also a large set of interrelated and spatially linked attributes. The GIS includes the accidents as georeferenced point elements with a spatially linked attribute database: identification information (date, location details); accident type; main, secondary and aggravating causes; data about driver; vehicle information; consequences (damages, injured peoples and fatalities). Each attribute has its own number code that allows both the statistical analysis and the spatial interrogation. The database includes those road accidents that led to physical injuries and loss of human lives between 2007 and 2012 and the spatial analysis was realized using TNTmips 7.3 software facilities. Data aggregation and processing allowed creating the spatial pattern of injury related road accidents through Kernel density estimation at three different levels (national - Romania; county level - Iasi County; local level - Iasi town). Spider graphs were used to create the temporal pattern or road accidents at three levels (daily, weekly and monthly) directly related to their causes. Moreover the spatial and temporal database relates the natural hazards (glazed frost, fog, and blizzard) with the human made ones, giving the opportunity to evaluate the nature of uncertainties in risk

  4. A low cost sensor network approach to investigate spatio-temporal patterns of stream temperatures and electrical conductivity

    Science.gov (United States)

    Lieder, Ernestine; Weiler, Markus; Blume, Theresa

    2016-04-01

    Understanding water and energy fluxes at the stream and catchment scale remains a challenging task. Within the CAOS-project-framework it is our aim to investigate spatiotemporal patterns of stream temperature and to deduce understanding about the underlying hydrological system. A low cost sensor network was installed in summer 2015 to monitor stream temperature and EC patterns in time and space. 90 HOBO temperature sensors, which were modified to additionally measure EC, were installed at 30 confluences across the Attert catchment (288 km²) in Luxembourg. The design of the sensor network allows for the investigation of three research questions: a) spatial patterns of stream temperatures and EC and their dynamics across the region b) estimation of relative streamflow contributions and their temporal dynamics by using simple mixing models and c) estimation of heat transport. The data will thus provide valuable insight in runoff contributions from different sub-catchments, and a combined analysis with distributed measurements of soil moisture and shallow groundwater will improve our process understanding by linking hillslope scale processes with stream responses. First results indicate that streams in different geologies show distinct temperature and EC patterns throughout the observation period. Differences are also found with respect to temporal dynamics both for longer periods as well as diurnal fluctuations. These differences are likely to be caused by differences in flow paths on the one hand (e.g. amount of groundwater contribution) and exposure to direct radiation on the other hand.

  5. Complex temporal and spatial patterns in nonequilibrium processes. Final report, December 1, 1987--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    Dynamical systems methods have been used to study bifurcations and pattern formation in nonequilibrium systems. Accomplishments during this period include: information-theoretic methods for analyzing chaos, chemical reactors for studying sustained reaction-diffusion patterns, a reactor exploiting pattern formation to extract short- lived intermediate species, observation of bifurcation from periodic to quasiperiodic rotating chemical spiral patterns, observation of a Turing bifurcation (transition from uniform state to a stationary chemical pattern), method for extracting noise strength in ramped convection, self-similar fractal structure of Zn clusters in electrodeposition, and dynamical instability in crack propagation.

  6. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

    Science.gov (United States)

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-04-01

    The seasonality of woody plants in cold and temperate climates is adapted to the annual course of temperature and photoperiod in order to maximise the length of the active growing season and, at the same time, avoid damages by frost events, especially by late spring frosts. Winter chilling, spring warming and finally photoperiod trigger the timely bud burst of European beech (Fagus sylvatica L.) which as a climax species is quite sensitive to winter frost and also as seedling to late spring frosts. However, due to relatively late and less varying dates of leaf unfolding, damages by late spring frosts should not occur each year. In case of a total loss due to a late frost event, F. sylvatica trees produce a new set of leaves which guarantees survival, but diminishes carbon reserves. With a phenological camera we observed the phenological course of such an extreme event in the Nationalpark Bayerischer Wald in May 2011: Spring leaf unfolding, an almost complete loss of fresh green leaves after the frost event in the night 3rd to 4th May, a subsequent leafless period followed by re-sprouting. We modeled this special leaf development from day 80 to 210, observed as green% from the repeated digital camera pictures, using the Bayesian multiple change point approach recently introduced by Henneken et al. (2013). The results for more than 30 trees predominantly suggested a model with five change points: firstly, start of the season, abrupt ending before the frost event, the loss by the frost event and after a longer period of recovery the second leaf unfolding (St. John's sprout) ending in full leaf maturity. Analyzing the results of these models the following questions were answered (1) how long is the period of recovery till the second green-up? (2) does the temporal course of the second leafing differ from the first one? (3) what are the individual factors influencing damage and recovery? (4) are individuals with early or late bud burst more prone to damage? The five

  7. Spatio-Temporal Stochastic Pattern Generator for ensemble prediction and ensemble data assimilation in geophysical applications

    CERN Document Server

    Tsyrulnikov, Michael

    2016-01-01

    A generator of spatio-temporal pseudo-random Gaussian fields that satisfy the "proportionality of scales" property (Tsyroulnikov 2001) is presented. The generator is a third-order in time stochastic differential equation with a pseudo-differential spatial operator defined on a limited area domain in Cartesian coordinate system. The spatial covariance functions of the generated fields belong to the Mat\\'ern class. The spatio-temporal covariances are non-separable. A spectral-space numerical solver is implemented and accelerated exploiting properties of real-world geophysical fields, in particular, smoothness of their spatial spectra. The generator is designed to simulate additive or multiplicative, or other spatio-temporal perturbations that represent uncertainties in numerical prediction models in geophysics. The program code of the generator is publicly available.

  8. Dynamic maps: a visual-analytic methodology for exploring spatio-temporal disease patterns

    Directory of Open Access Journals (Sweden)

    Chui Kenneth KH

    2009-12-01

    Full Text Available Abstract Background Epidemiologic studies are often confounded by the human and environmental interactions that are complex and dynamic spatio-temporal processes. Hence, it is difficult to discover nuances in the data and generate pertinent hypotheses. Dynamic mapping, a method to simultaneously visualize temporal and spatial information, was introduced to elucidate such complexities. A conceptual framework for dynamic mapping regarding principles and implementation methods was proposed. Methods The spatio-temporal dynamics of Salmonella infections for 2002 in the U.S. elderly were depicted via dynamic mapping. Hospitalization records were obtained from the Centers of Medicare and Medicaid Services. To visualize the spatial relationship, hospitalization rates were computed and superimposed onto maps of environmental exposure factors including livestock densities and ambient temperatures. To visualize the temporal relationship, the resultant maps were composed into a movie. Results The dynamic maps revealed that the Salmonella infections peaked at specific spatio-temporal loci: more clusters were observed in the summer months and higher density of such clusters in the South. The peaks were reached when the average temperatures were greater than 83.4°F (28.6°C. Although the relationship of salmonellosis rates and occurrence of temperature anomalies was non-uniform, a strong synchronization was found between high broiler chicken sales and dense clusters of cases in the summer. Conclusions Dynamic mapping is a practical visual-analytic technique for public health practitioners and has an outstanding potential in providing insights into spatio-temporal processes such as revealing outbreak origins, percolation and travelling waves of the diseases, peak timing of seasonal outbreaks, and persistence of disease clusters.

  9. Spatio-Temporal Patterns of the International Merger and Acquisition Network

    OpenAIRE

    Duenas, Marco; Mastrandrea, Rossana; Barigozzi, Matteo; Fagiolo, Giorgio

    2017-01-01

    This paper analyses the world web of mergers and acquisitions (M&As) using a complex network approach. We use data of M&As to build a temporal sequence of binary and weighted-directed networks for the period 1995-2010 and 224 countries (nodes) connected according to their M&As flows (links). We study different geographical and temporal aspects of the international M&A network (IMAN), building sequences of filtered sub-networks whose links belong to specific intervals of distance or time. Give...

  10. Spatio-temporal patterns and climate variables controlling of biomass carbon stock of global grassland ecosystems from 1982 to 2006

    Science.gov (United States)

    Xia, Jiangzhou; Liu, Shuguang; Liang, Shunlin; Chen, Yang; Xu, Wenfang; Yuan, Wenping

    2014-01-01

    Grassland ecosystems play an important role in subsistence agriculture and the global carbon cycle. However, the global spatio-temporal patterns and environmental controls of grassland biomass are not well quantified and understood. The goal of this study was to estimate the spatial and temporal patterns of the global grassland biomass and analyze their driving forces using field measurements, Normalized Difference Vegetation Index (NDVI) time series from satellite data, climate reanalysis data, and a satellite-based statistical model. Results showed that the NDVI-based biomass carbon model developed from this study explained 60% of the variance across 38 sites globally. The global carbon stock in grassland aboveground live biomass was 1.05 Pg·C, averaged from 1982 to 2006, and increased at a rate of 2.43 Tg·C·y−1 during this period. Temporal change of the global biomass was significantly and positively correlated with temperature and precipitation. The distribution of biomass carbon density followed the precipitation gradient. The dynamics of regional grassland biomass showed various trends largely determined by regional climate variability, disturbances, and management practices (such as grazing for meat production). The methods and results from this study can be used to monitor the dynamics of grassland aboveground biomass and evaluate grassland susceptibility to climate variability and change, disturbances, and management.

  11. Revealing Patterns and Trends of Mass Mobility Through Spatial and Temporal Abstraction of Origin-Destination Movement Data.

    Science.gov (United States)

    Andrienko, Gennady; Andrienko, Natalia; Fuchs, Georg; Wood, Jo

    2017-09-01

    Origin-destination (OD) movement data describe moves or trips between spatial locations by specifying the origins, destinations, start, and end times, but not the routes travelled. For studying the spatio-temporal patterns and trends of mass mobility, individual OD moves of many people are aggregated into flows (collective moves) by time intervals. Time-variant flow data pose two difficult challenges for visualization and analysis. First, flows may connect arbitrary locations (not only neighbors), thus making a graph with numerous edge intersections, which is hard to visualize in a comprehensible way. Even a single spatial situation consisting of flows in one time step is hard to explore. The second challenge is the need to analyze long time series consisting of numerous spatial situations. We present an approach facilitating exploration of long-term flow data by means of spatial and temporal abstraction. It involves a special way of data aggregation, which allows representing spatial situations by diagram maps instead of flow maps, thus reducing the intersections and occlusions pertaining to flow maps. The aggregated data are used for clustering of time intervals by similarity of the spatial situations. Temporal and spatial displays of the clustering results facilitate the discovery of periodic patterns and longer-term trends in the mass mobility behavior.

  12. Temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy field at Kelantan, Malaysia.

    Science.gov (United States)

    Hussain, Hazilia; Yusoff, Mohd Kamil; Ramli, Mohd Firuz; Abd Latif, Puziah; Juahir, Hafizan; Zawawi, Mohamed Azwan Mohammed

    2013-11-15

    Nitrate-nitrogen leaching from agricultural areas is a major cause for groundwater pollution. Polluted groundwater with high levels of nitrate is hazardous and cause adverse health effects. Human consumption of water with elevated levels of NO3-N has been linked to the infant disorder methemoglobinemia and also to non-Hodgkin's disease lymphoma in adults. This research aims to study the temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy soil at Ladang Merdeka Ismail Mulong in Kelantan, Malaysia. The complex data matrix (128 x 16) of nitrate-nitrogen parameters was subjected to multivariate analysis mainly Principal Component Analysis (PCA) and Discriminant Analysis (DA). PCA extracted four principal components from this data set which explained 86.4% of the total variance. The most important contributors were soil physical properties confirmed using Alyuda Forecaster software (R2 = 0.98). Discriminant analysis was used to evaluate the temporal variation in soil nitrate-nitrogen on leaching process. Discriminant analysis gave four parameters (hydraulic head, evapotranspiration, rainfall and temperature) contributing more than 98% correct assignments in temporal analysis. DA allowed reduction in dimensionality of the large data set which defines the four operating parameters most efficient and economical to be monitored for temporal variations. This knowledge is important so as to protect the precious groundwater from contamination with nitrate.

  13. Persistent patterns of brain activity: an EEG coherence study of the positive effect of music on spatial-temporal reasoning.

    Science.gov (United States)

    Sarnthein, J; vonStein, A; Rappelsberger, P; Petsche, H; Rauscher, F H; Shaw, G L

    1997-04-01

    Motivated by predictions from the structured trion model of the cortex, behavioral experiments have demonstrated a causal short-term enhancement of spatial-temporal reasoning in college students following exposure to a Mozart sonata, but not in control conditions. The coherence analysis of electroencephalogram (EEG) recordings is well suited to the neurophysiological investigation of this behavioral enhancement. Here we report the presence of right frontal and left temporo-parietal coherent activity induced by listening to Mozart which carried over into the spatial-temporal tasks in three of our seven subjects. This carry-over effect was compared to EEG coherence analysis of spatial-temporal-tasks after listening to text. We suggest that these EEG coherence results provide the beginnings of understanding of the neurophysiological basis of the causal enhancement of spatial-temporal reasoning by listening to specific music. The observed long-lasting coherent EEG pattern might be evidence for structured sequences in cortical dynamics which extend over minutes.

  14. Three-dimensional knee kinematics by conventional gait analysis for eleven motor tasks of daily living: typical patterns and repeatability.

    Science.gov (United States)

    Scheys, Lennart; Leardini, Alberto; Wong, Pius D; Van Camp, Laurent; Callewaert, Barbara; Bellemans, Johan; Desloovere, Kaat

    2013-04-01

    The availability of detailed knee kinematic data during various activities can facilitate clinical studies of this joint. To describe in detail normal knee joint rotations in all three anatomical planes, 25 healthy subjects (aged 22-49 years) performed eleven motor tasks, including walking, step ascent and descent, each with and without sidestep or crossover turns, chair rise, mild and deep squats, and forward lunge. Kinematic data were obtained with a conventional lower-body gait analysis protocol over three trials per task. To assess the repeatability with standard indices, a representative subset of 10 subjects underwent three repetitions of the entire motion capture session. Extracted parameters with good repeatability included maximum and minimum axial rotation during turning, local extremes of the flexion curves during gait tasks, and stride times. These specific repeatable parameters can be used for task selection or power analysis when planning future clinical studies.

  15. Spatio-temporal patterns of gun violence in Syracuse, New York 2009-2015.

    Science.gov (United States)

    Larsen, David A; Lane, Sandra; Jennings-Bey, Timothy; Haygood-El, Arnett; Brundage, Kim; Rubinstein, Robert A

    2017-01-01

    Gun violence in the United States of America is a large public health problem that disproportionately affects urban areas. The epidemiology of gun violence reflects various aspects of an infectious disease including spatial and temporal clustering. We examined the spatial and temporal trends of gun violence in Syracuse, New York, a city of 145,000. We used a spatial scan statistic to reveal spatio-temporal clusters of gunshots investigated and corroborated by Syracuse City Police Department for the years 2009-2015. We also examined predictors of areas with increased gun violence using a multi-level zero-inflated Poisson regression with data from the 2010 census. Two space-time clusters of gun violence were revealed in the city. Higher rates of segregation, poverty and the summer months were all associated with increased risk of gun violence. Previous gunshots in the area were associated with a 26.8% increase in the risk of gun violence. Gun violence in Syracuse, NY is both spatially and temporally stable, with some neighborhoods of the city greatly afflicted.

  16. Spatio-temporal patterns of gun violence in Syracuse, New York 2009-2015

    Science.gov (United States)

    Lane, Sandra; Jennings-Bey, Timothy; Haygood-El, Arnett; Brundage, Kim; Rubinstein, Robert A.

    2017-01-01

    Gun violence in the United States of America is a large public health problem that disproportionately affects urban areas. The epidemiology of gun violence reflects various aspects of an infectious disease including spatial and temporal clustering. We examined the spatial and temporal trends of gun violence in Syracuse, New York, a city of 145,000. We used a spatial scan statistic to reveal spatio-temporal clusters of gunshots investigated and corroborated by Syracuse City Police Department for the years 2009–2015. We also examined predictors of areas with increased gun violence using a multi-level zero-inflated Poisson regression with data from the 2010 census. Two space-time clusters of gun violence were revealed in the city. Higher rates of segregation, poverty and the summer months were all associated with increased risk of gun violence. Previous gunshots in the area were associated with a 26.8% increase in the risk of gun violence. Gun violence in Syracuse, NY is both spatially and temporally stable, with some neighborhoods of the city greatly afflicted. PMID:28319125

  17. COMPOSE: Using temporal patterns for interpreting wearable sensor data with computer interpretable guidelines

    NARCIS (Netherlands)

    Urovi, Visara; Jimenez del Toro, Oscar; Dubosson, Fabian; Ruiz Torres, Alehandra; Schumacher, Michael Ignaz

    2017-01-01

    This paper describes a novel temporal logic-based framework for reasoning with continuous data collected from wearable sensors. The work is motivated by the Metabolic Syndrome, a cluster of conditions which are linked to obesity and unhealthy lifestyle. We assume that, by interpreting the physiologi

  18. Disordered semantic representation in schizophrenic temporal cortex revealed by neuromagnetic response patterns

    Directory of Open Access Journals (Sweden)

    Silberman Yaron

    2006-05-01

    Full Text Available Abstract Background Loosening of associations and thought disruption are key features of schizophrenic psychopathology. Alterations in neural networks underlying this basic abnormality have not yet been sufficiently identified. Previously, we demonstrated that spatio-temporal clustering of magnetic brain responses to pictorial stimuli map categorical representations in temporal cortex. This result has opened the possibility to quantify associative strength within and across semantic categories in schizophrenic patients. We hypothesized that in contrast to controls, schizophrenic patients exhibit disordered representations of semantic categories. Methods The spatio-temporal clusters of brain magnetic activities elicited by object pictures related to super-ordinate (flowers, animals, furniture, clothes and base-level (e.g. tulip, rose, orchid, sunflower categories were analysed in the source space for the time epochs 170–210 and 210–450 ms following stimulus onset and were compared between 10 schizophrenic patients and 10 control subjects. Results Spatio-temporal correlations of responses elicited by base-level concepts and the difference of within vs. across super-ordinate categories were distinctly lower in patients than in controls. Additionally, in contrast to the well-defined categorical representation in control subjects, unsupervised clustering indicated poorly defined representation of semantic categories in patients. Within the patient group, distinctiveness of categorical representation in the temporal cortex was positively related to negative symptoms and tended to be inversely related to positive symptoms. Conclusion Schizophrenic patients show a less organized representation of semantic categories in clusters of magnetic brain responses than healthy adults. This atypical neural network architecture may be a correlate of loosening of associations, promoting positive symptoms.

  19. Spatial and temporal patterns of chronic wasting disease: fine-scale mapping of a wildlife epidemic in Wisconsin.

    Science.gov (United States)

    Osnas, Erik E; Heisey, Dennis M; Rolley, Robert E; Samuel, Michael D

    2009-07-01

    Emerging infectious diseases threaten wildlife populations and human health. Understanding the spatial distributions of these new diseases is important for disease management and policy makers; however, the data are complicated by heterogeneities across host classes, sampling variance, sampling biases, and the space-time epidemic process. Ignoring these issues can lead to false conclusions or obscure important patterns in the data, such as spatial variation in disease prevalence. Here, we applied hierarchical Bayesian disease mapping methods to account for risk factors and to estimate spatial and temporal patterns of infection by chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) of Wisconsin, U.S.A. We found significant heterogeneities for infection due to age, sex, and spatial location. Infection probability increased with age for all young deer, increased with age faster for young males, and then declined for some older animals, as expected from disease-associated mortality and age-related changes in infection risk. We found that disease prevalence was clustered in a central location, as expected under a simple spatial epidemic process where disease prevalence should increase with time and expand spatially. However, we could not detect any consistent temporal or spatiotemporal trends in CWD prevalence. Estimates of the temporal trend indicated that prevalence may have decreased or increased with nearly equal posterior probability, and the model without temporal or spatiotemporal effects was nearly equivalent to models with these effects based on deviance information criteria. For maximum interpretability of the role of location as a disease risk factor, we used the technique of direct standardization for prevalence mapping, which we develop and describe. These mapping results allow disease management actions to be employed with reference to the estimated spatial distribution of the disease and to those host classes most at risk. Future

  20. Spatial and temporal patterns of chronic wasting disease: Fine-scale mapping of a wildlife epidemic in Wisconsin

    Science.gov (United States)

    Osnas, E.E.; Heisey, D.M.; Rolley, R.E.; Samuel, M.D.

    2009-01-01

    Emerging infectious diseases threaten wildlife populations and human health. Understanding the spatial distributions of these new diseases is important for disease management and policy makers; however, the data are complicated by heterogeneities across host classes, sampling variance, sampling biases, and the space-time epidemic process. Ignoring these issues can lead to false conclusions or obscure important patterns in the data, such as spatial variation in disease prevalence. Here, we applied hierarchical Bayesian disease mapping methods to account for risk factors and to estimate spatial and temporal patterns of infection by chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) of Wisconsin, USA. We found significant heterogeneities for infection due to age, sex, and spatial location. Infection probability increased with age for all young deer, increased with age faster for young males, and then declined for some older animals, as expected from disease-associated mortality and age-related changes in infection risk. We found that disease prevalence was clustered in a central location, as expected under a simple spatial epidemic process where disease prevalence should increase with time and expand spatially. However, we could not detect any consistent temporal or spatiotemporal trends in CWD prevalence. Estimates of the temporal trend indicated that prevalence may have decreased or increased with nearly equal posterior probability, and the model without temporal or spatiotemporal effects was nearly equivalent to models with these effects based on deviance information criteria. For maximum interpretability of the role of location as a disease risk factor, we used the technique of direct standardization for prevalence mapping, which we develop and describe. These mapping results allow disease management actions to be employed with reference to the estimated spatial distribution of the disease and to those host classes most at risk. Future

  1. Complex temporal and spatial patterns in nonequilibrium processes. Progress report, December 1, 1987--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Swinney, H.L.

    1992-10-01

    We have used dynamical systems methods to study and characterize bifurcations and pattern formation in a variety of nonequilibrium systems. In this paper we describe our work on dynamical systems, chemical oscillations and chaos, chemical spatial patterns, instabilities in fluid dynamics, electrodeposition clusters, the ballast resistor, and crack propagation.

  2. Spatial and temporal patterns of locally-acquired dengue transmission in northern Queensland, Australia, 1993-2012.

    Directory of Open Access Journals (Sweden)

    Suchithra Naish

    Full Text Available Dengue has been a major public health concern in Australia since it re-emerged in Queensland in 1992-1993. We explored spatio-temporal characteristics of locally-acquired dengue cases in northern tropical Queensland, Australia during the period 1993-2012.Locally-acquired notified cases of dengue were collected for northern tropical Queensland from 1993 to 2012. Descriptive spatial and temporal analyses were conducted using geographic information system tools and geostatistical techniques.2,398 locally-acquired dengue cases were recorded in northern tropical Queensland during the study period. The areas affected by the dengue cases exhibited spatial and temporal variation over the study period. Notified cases of dengue occurred more frequently in autumn. Mapping of dengue by statistical local areas (census units reveals the presence of substantial spatio-temporal variation over time and place. Statistically significant differences in dengue incidence rates among males and females (with more cases in females (χ(2 = 15.17, d.f.  = 1, p<0.01. Differences were observed among age groups, but these were not statistically significant. There was a significant positive spatial autocorrelation of dengue incidence for the four sub-periods, with the Moran's I statistic ranging from 0.011 to 0.463 (p<0.01. Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the northern Queensland.Tropical areas are potential high-risk areas for mosquito-borne diseases such as dengue. This study demonstrated that the locally-acquired dengue cases have exhibited a spatial and temporal variation over the past twenty years in northern tropical Queensland, Australia. Therefore, this study provides an impetus for further investigation of clusters and risk factors in these high-risk areas.

  3. Spatial and Temporal Patterns of Locally-Acquired Dengue Transmission in Northern Queensland, Australia, 1993–2012

    Science.gov (United States)

    Naish, Suchithra; Dale, Pat; Mackenzie, John S.; McBride, John; Mengersen, Kerrie; Tong, Shilu

    2014-01-01

    Background Dengue has been a major public health concern in Australia since it re-emerged in Queensland in 1992–1993. We explored spatio-temporal characteristics of locally-acquired dengue cases in northern tropical Queensland, Australia during the period 1993–2012. Methods Locally-acquired notified cases of dengue were collected for northern tropical Queensland from 1993 to 2012. Descriptive spatial and temporal analyses were conducted using geographic information system tools and geostatistical techniques. Results 2,398 locally-acquired dengue cases were recorded in northern tropical Queensland during the study period. The areas affected by the dengue cases exhibited spatial and temporal variation over the study period. Notified cases of dengue occurred more frequently in autumn. Mapping of dengue by statistical local areas (census units) reveals the presence of substantial spatio-temporal variation over time and place. Statistically significant differences in dengue incidence rates among males and females (with more cases in females) (χ2 = 15.17, d.f. = 1, p<0.01). Differences were observed among age groups, but these were not statistically significant. There was a significant positive spatial autocorrelation of dengue incidence for the four sub-periods, with the Moran's I statistic ranging from 0.011 to 0.463 (p<0.01). Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the northern Queensland. Conclusions Tropical areas are potential high-risk areas for mosquito-borne diseases such as dengue. This study demonstrated that the locally-acquired dengue cases have exhibited a spatial and temporal variation over the past twenty years in northern tropical Queensland, Australia. Therefore, this study provides an impetus for further investigation of clusters and risk factors in these high-risk areas. PMID:24691549

  4. Temporal patterns of ant diversity across a mountain with climatically contrasting aspects in the tropics of Africa.

    Directory of Open Access Journals (Sweden)

    Thinandavha Caswell Munyai

    Full Text Available Factors that drive species richness over space and time are still poorly understood and are often context specific. Identifying these drivers for ant diversity has become particularly relevant within the context of contemporary global change events. We report on a long-term bi-annual (wet and dry seasons, standardized sampling of epigeal ants over a five year period on the mesic and arid aspects of an inselberg (Soutpansberg Mountain Range in the tropics of Africa. We detail seasonal, annual and long-term trends of species density, test the relative contribution of geometric constraints, energy, available area, climate, local environmental variables, time, and space in explaining ant species density patterns through Generalized Linear Mixed Models (GLMM where replicates were included as random factors to account for temporal pseudo-replication. Seasonal patterns were very variable and we found evidence of decreased seasonal variation in species density with increased elevation. The extent and significance of a decrease in species density with increased elevation varied with season. Annual patterns point to an increase in ant diversity over time. Ant density patterns were positively correlated with mean monthly temperature but geometric constraints dominated model performance while soil characteristics were minor correlates. These drivers and correlates accounted for all the spatio-temporal variability in the database. Ant diversity was therefore mainly determined by geometric constraints and temperature while soil characteristics (clay and carbon content accounted for smaller but significant amounts of variation. This study documents the role of season, elevation and their interaction in affecting ant species densities while highlighting the importance of neutral processes and temperature in driving these patterns.

  5. Long-term analysis of spatio-temporal patterns in population dynamics and demography of juvenile Pinfish (Lagodon rhomboides)

    Science.gov (United States)

    Chacin, D. H.; Switzer, T. S.; Ainsworth, C. H.; Stallings, C. D.

    2016-12-01

    In estuarine systems, proximity to the ocean has the potential to directly and indirectly drive patterns of fish distribution and population dynamics. To test this hypothesis, we conducted a comprehensive analysis of fisheries-independent data and quantified patterns of density, biomass, and growth rates of juvenile Pinfish (Lagodon rhomboides) across spatial and temporal scales in Tampa Bay, Florida, USA. Spatially, the highest density and biomass were found in the outermost regions (closest to the Gulf of Mexico) of the Bay, and these patterns were generally consistent temporally. Inter-annually, Pinfish density and biomass were the highest during periods coinciding with favorable oceanographic conditions (e.g., anomalously intense and prolonged upwelling) for across-shelf transport of larvae from spawning grounds in the Gulf to Tampa Bay. Intra-annually, density and biomass were the highest during spring and summer likely due to the combined effects of spawning timing (and delivery of new settlers), and high somatic growth fueled by increased secondary and primary productivity. Declines in density and biomass during the late summer through early winter were possibly due to high post-settlement mortality and egress to offshore habitats. Pinfish increased predictably in size across the months of the calendar year, and tended to be larger and grew faster in the innermost regions of the Bay, which were located farthest from the Gulf. Pinfish density was related to the proximity to the Gulf of Mexico, with the outermost regions of the Bay having greater seagrass cover, higher salinity, and being closer to the offshore larval pool where spawning occurs. Thus, this study provided evidence that distance to the ocean was an important driver of biotic and abiotic factors that influenced Pinfish demographic rates across spatial and temporal scales in the largest estuary in Florida.

  6. Spatial and temporal patterns in Cimex lectularius (Hemiptera: Cimicidae) reporting in Philadelphia, PA.

    Science.gov (United States)

    Mabud, Tarub S; Barbarin, Alexis M; Barbu, Corentin M; Levy, Katelyn H; Edinger, Jason; Levy, Michael Z

    2014-01-01

    We analyzed a comprehensive telephone log of pest infestation reports to assess the spatial and temporal trends in Cimex lectularius L. (bed bug) reporting throughout Philadelphia, PA. Citywide spatial analyses of reports from September 2011 to June 2012 revealed several statistically significant bed bug hotspots. However, these were small and diffuse. Temporal analyses of reports from December 2008 to May 2011 detected prominent seasonality in bed bug reporting, peaking in August and reaching a nadir in February each year. Controlling for seasonal cycling, the number of bed bug reports in Philadelphia increased steadily at a rate of approximately 4.5% per month (or 69.45% per year) from December 2008 to May 2011. While it may be difficult to spatially target citywide bed bug control measures because of the insects' widespread migration, interventions informed by seasonal trends may enhance efforts to curb the recent increases in urban bed bug populations.

  7. A novel method for spatio-temporal pattern analysis of brain fMRI data

    Institute of Scientific and Technical Information of China (English)

    LIU Yadong; ZHOU Zongtan; HU Dewen; YAN Lirong; TAN Changlian; WU Daxing; YAO Shuqiao

    2005-01-01

    A novel data processing procedure for fMRI was suggested in this paper, by which spatial and temporal characteristics of stimuli-induced signal dynamic responses can be investigated simultaneously. First the multitaper spectral estimation was utilized to estimate the spectrum of each voxel; the significance of the line frequency components at the interested frequency was tested to detect the task-related cortex areas; the temporal independent component analysis (tICA) was then applied to the activated voxels to obtain stimuli-induced signal dynamic responses. The advantages of this procedure are: few assumptions are needed for the cerebral hemodynamics and spatial distribution of task-related areas, problems which often appear in tICA analysis of fMRI data, such as the lack of stability, reliability and robustness, are overcome by the suggested method.

  8. Spatio-temporal pattern of viral meningitis in Michigan, 1993-2001

    Science.gov (United States)

    Greene, Sharon K.; Schmidt, Mark A.; Stobierski, Mary Grace; Wilson, Mark L.

    2005-05-01

    To characterize Michigan's high viral meningitis incidence rates, 8,803 cases from 1993-2001 were analyzed for standard epidemiological indices, geographic distribution, and spatio-temporal clusters. Blacks and infants were found to be high-risk groups. Annual seasonality and interannual variability in epidemic magnitude were apparent. Cases were concentrated in southern Michigan, and cumulative incidence was correlated with population density at the county level (r=0.45, p<0.001). Kulldorff's Scan test identified the occurrence of spatio-temporal clusters in Lower Michigan during July-October 1998 and 2001 (p=0.01). More extensive data on cases, laboratory isolates, sociodemographics, and environmental exposures should improve detection and enhance the effectiveness of a Space-Time Information System aimed at prevention.

  9. Evaluation of spatial and temporal root water uptake patterns of a flood-irrigated pecan tree using the hydrus (2D/3D) model

    OpenAIRE

    Deb, SK; Shukla, MK; J. Šimůnek; Mexal, JG

    2013-01-01

    Quantitative information about the spatial and temporal patterns of compensatory root water uptake (RWU) in flood-irrigated pecan orchard is limited. We evaluated spatio-temporal compensated and uncompensated RWU patterns of mature pecan tree in a silty clay loam orchard using the HYDRUS (2D/3D) model. HYDRUS (2D/3D) simulations, which agreed well with measured water contents and temperatures at different soil depths and horizontal distances from the tree trunk, suggested that while both comp...

  10. Space-borne Chlorophyll Fluorescence, Greenness, Vegetation Models and Interannual Variability of Photosynthetic Activity: Spatio-temporal Patterns, Mechanisms, and Environmental Sensitivities

    Science.gov (United States)

    Walther, S.; Guanter, L.; Jung, M.; Frankenberg, C.; Sun, Y.; Forkel, M.; Zhang, Y.; Duveiller, G.; Cescatti, A.; Camps-Valls, G.; Köhler, P.

    2016-12-01

    It is much debated whether respiration or photosynthesis drive net ecosystem productivity andwhich regions contribute strongest to the observed interannual variability (IAV) of the strengthof the land sink. Several studies point to photosynthetic productivity in semi-arid regions as avery important factor influencing atmospheric CO2 variability globally (e.g. Jung et al., 2011;Poulter et al., 2014; Ahlstr ̈ om et al., 2015). Here, we aim at a comprehensive comparison ofthe strength, timing and spatial extent of anomalies of photosynthesis as they are indicated bysatellite observations of greenness, vegetation optical depth, and sun-induced chlorophyll fluo-rescence (SIF). We will compare them to the results of diagnostic, empirical and process-basedvegetation models. Except for the evergreen tropics, the spatio-temporal patterns of monthlydominant vegetation variability are generally consistently shown in semi-arid areas, albeit withdiffering magnitudes between greenness and photosynthesis globally. Relative anomalies (to themean seasonal cycle) are particularly widespread in high northern latitudes. Further researchsteps will include i) the repeated analysis at higher temporal resolution to better refine the dif-ferent time scales of reaction between light-use-efficiency and APAR and between forestedand non-forested ecosystems, ii) investigate on characteristic time scales at which the proxies(dis-)agree and why, iii) study the relative contributions of anomalies in peak and length of thegrowing season to IAV (similar to Xia et al., 2015; Zhou et al., 2016), iv) analyse the proxiesfor possibly differing hydrological sensitivities, and v) vegetation models have long been knownto have very diverse abilities to capture GPP IAV. Our preliminary results confirm this and wewill further study possible limitations and possible ways for improvement of the simulations.

  11. Spatio-temporal patterns of recurrent slope instabilities affecting undercut slopes in flysch: A dendrogeomorphic approach using broad-leaved trees

    Science.gov (United States)

    Šilhán, Karel; Pánek, Tomáš; Turský, Ondřej; Brázdil, Rudolf; Klimeš, Jan; Kašičková, Lucie

    2014-05-01

    The undercut slope of the Skalická Strážnice/Vrchy hill situated in the piedmont of the Carpathian Mountains (Czech Republic) is a regional landslide "hotspot", notorious for its repeated recent and historical sliding reactivations. We performed tree-ring analysis of a large number (n = 274) of broad-leaved trees to reconstruct the spatio-temporal patterns of landslide reactivation for a period spanning more than one hundred years (1884-2011). Although tree rings of broad-leaved trees are less-reliable archives of landslide activity than those of conifers, the application of a methodology based on the weighting of disturbance signals within eccentricity series generated a usable dataset of sliding activity affecting anisotropic flysch bedrock. Although some known landslide years could not be found (or were expressed by only weak signals) in the reconstructed dataset, the majority of landslide events reconstructed from the tree-ring series coincide with hydrometeorological data, revealing a correlation with heavy summer rainfalls lasting from two to ten days. The spatial distribution of landslide recurrence derived from the tree-ring records together with electrical resistivity tomography and a kinematic analysis of slope failures suggest a close link between the concentration of landslide activity and the presence of faulted or fractured flysch bedrock.

  12. Temporal and spatial expression patterns of biomineralization proteins during early development in the stony coral Pocillopora damicornis.

    Science.gov (United States)

    Mass, Tali; Putnam, Hollie M; Drake, Jeana L; Zelzion, Ehud; Gates, Ruth D; Bhattacharya, Debashish; Falkowski, Paul G

    2016-04-27

    Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete skeleton and a protein-rich skeletal organic matrix that attach them to the reef. Here, we characterized the temporal and spatial expression pattern of a suite of biomineralization genes during three stages of larval development in the reef-building coral Pocillopora damicornis: stage I, newly released; stage II, oral-aborally compressed and stage III, settled and calcifying spat. Transcriptome analysis revealed 3882 differentially expressed genes that clustered into four distinctly different patterns of expression change across the three developmental stages. Immunolocalization analysis further reveals the spatial arrangement of coral acid-rich proteins (CARPs) in the overall architecture of the emerging skeleton. These results provide the first analysis of the timing of the biomineralization 'toolkit' in the early life history of a stony coral. © 2016 The Author(s).

  13. A model-based analysis of chemical and temporal patterns of cuticular hydrocarbons in male Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Clement Kent

    Full Text Available Drosophila Cuticular Hydrocarbons (CH influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions.

  14. Spatial and Temporal Patterns of Vegetation in Water-Limited Ecosystems: The Role of Interannual Rainfall Variability.

    Science.gov (United States)

    Fernandez-Illescas, C. P.; Rodriguez-Iturbe, I.

    2001-12-01

    In water-limited ecosystems, soil water availability lies at the center of a complex coupling between vegetation and climate. Attempts to understand the temporal and spatial vegetation structure of such systems require the formulation of an spatially explicit model of evolutionary dynamics which accounts for temporal fluctuations in soil moisture amounts. Previous work has linked the analytical treatment of the vegetation-soil-climate system described by Laio et al. (2001) and Porporato et al. (2001) characterizing the impact of intraseasonal soil moisture variability on vegetation overall condition with the hierarchical competition-colonization model of Tilman (1994). In this way, the impact of interannual rainfall fluctuations is incorporated into a model of species competition. Such a hydrologically driven hierarchical competition-colonization model is here modified to differentiate between local and global seed dispersal abilities. Simulations at the La Copita savanna site in Texas where the herbaceous C4 Paspaleum setaceum and the woody Prosopis glandulosa (honey mesquite) coexist, suggest that interannual rainfall variability enhances the impact of local dispersion on the temporal evolution of species abundances as well as on the spatial structure of vegetation. Various descriptors of vegetation patterns, (e.g. cluster size distributions, fractal dimensions) and their sensitivity to interannual rainfall fluctuations will be discussed.

  15. Dietary patterns extracted from the current Japanese diet and their associations with sodium and potassium intakes estimated by repeated 24 h urine collection.

    Science.gov (United States)

    Fujiwara, Aya; Asakura, Keiko; Uechi, Ken; Masayasu, Shizuko; Sasaki, Satoshi

    2016-10-01

    To identify dietary patterns in the current Japanese diet and evaluate the associations between these patterns and Na and K intakes. Dietary patterns were extracted by factor analysis from the intakes of food groups assessed with a validated self-administrated diet history questionnaire. Na and K intakes and urinary Na:K were assessed by repeated 24 h urine collection. Healthy Japanese adults aged 20-69 years (353 men and 349 women). Twenty study areas in twenty-three prefectures in Japan. Result Four dietary patterns were identified in each sex. After adjustment for several confounding factors, the 'Fish and vegetable' pattern was associated with higher urinary Na excretion, but the association was not significant (P=0·37 in men and P=0·06 in women). This pattern was also associated with higher K excretion in both sexes. The 'Noodle' pattern tended to be associated with higher urinary Na excretion (P=0·17 in men and P=0·04 in women) and higher Na:K (P=0·02 in men). The 'Meat, vegetable and oil' (in men)/'Meat and oil' (in women) and 'Bread and confectioneries' patterns were not associated with urinary Na excretion (in men) or were negatively associated (in women). Contrary to the case in Western countries, the 'Fish and vegetable' and 'Noodle' patterns contributed to higher Na intake in Japan. Target foods for salt reduction should be set based on careful consideration of the relationships between dietary patterns and Na and K intakes in the target population.

  16. Multiscale temporal variability and regional patterns in 555 years of conterminous U.S. streamflow

    Science.gov (United States)

    Ho, Michelle; Lall, Upmanu; Sun, Xun; Cook, Edward R.

    2017-04-01

    The development of paleoclimate streamflow reconstructions in the conterminous United States (CONUS) has provided water resource managers with improved insights into multidecadal and centennial scale variability that cannot be reliably detected using shorter instrumental records. Paleoclimate streamflow reconstructions have largely focused on individual catchments limiting the ability to quantify variability across the CONUS. The Living Blended Drought Atlas (LBDA), a spatially and temporally complete 555 year long paleoclimate record of summer drought across the CONUS, provides an opportunity to reconstruct and characterize streamflow variability at a continental scale. We explore the validity of the first paleoreconstructions of streamflow that span the CONUS informed by the LBDA targeting a set of U.S. Geological Survey streamflow sites. The reconstructions are skillful under cross validation across most of the country, but the variance explained is generally low. Spatial and temporal structures of streamflow variability are analyzed using hierarchical clustering, principal component analysis, and wavelet analyses. Nine spatially coherent clusters are identified. The reconstructions show signals of contemporary droughts such as the Dust Bowl (1930s) and 1950s droughts. Decadal-scale variability was detected in the late 1900s in the western U.S., however, similar modes of temporal variability were rarely present prior to the 1950s. The twentieth century featured longer wet spells and shorter dry spells compared with the preceding 450 years. Streamflows in the Pacific Northwest and Northeast are negatively correlated with the central U.S. suggesting the potential to mitigate some drought impacts by balancing economic activities and insurance pools across these regions during major droughts.

  17. Spatial and temporal patterns of floral scent emission in Dianthus inoxianus and electroantennographic responses of its hawkmoth pollinator.

    Science.gov (United States)

    Balao, Francisco; Herrera, Javier; Talavera, Salvador; Dötterl, Stefan

    2011-05-01

    Scent emission is important in nocturnal pollination systems, and plant species pollinated by nocturnal insects often present characteristic odor compositions and temporal patterns of emission. We investigated the temporal (day/night; flower lifetime) and spatial (different flower parts, nectar) pattern of flower scent emission in nocturnally pollinated Dianthusinoxianus, and determined which compounds elicit physiological responses on the antennae of the sphingid pollinator Hyles livornica. The scent of D.inoxianus comprises 68 volatile compounds, but is dominated by aliphatic 2-ketones and sesquiterpenoids, which altogether make up 82% of collected volatiles. Several major and minor compounds elicit electrophysiological responses in the antennae of H. livornica. Total odor emission does not vary along day and night hours, and neither does along the life of the flower. However, the proportion of compounds eliciting physiological responses varies between day and night. All flower parts as well as nectar release volatiles. The scent of isolated flower parts is dominated by fatty acid derivatives, whereas nectar is dominated by benzenoids. Dissection (= damage) of flowers induced a ca. 20-fold increase in the rate of emission of EAD-active volatiles, especially aliphatic 2-ketones. We suggest that aliphatic 2-ketones might contribute to pollinator attraction in D. inoxianus, even though they have been attributed an insect repellent function in other plant species. We also hypothesize that the benzenoids in nectar may act as an honest signal ('nectar guide') for pollinators.

  18. Spatio-temporal changes of lymphatic contractility and drainage patterns following lymphadenectomy in mice.

    Directory of Open Access Journals (Sweden)

    Sunkuk Kwon

    Full Text Available OBJECTIVE: To investigate the redirection of lymphatic drainage post-lymphadenectomy using non-invasive near-infrared fluorescence (NIRF imaging, and to subsequently assess impact on metastasis. BACKGROUND: Cancer-acquired lymphedema arises from dysfunctional fluid transport after lymphadenectomy performed for staging and to disrupt drainage pathways for regional control of disease. However, little is known about the normal regenerative processes of the lymphatics in response to lymphadenectomy and how these responses can be accelerated, delayed, or can impact metastasis. METHODS: Changes in lymphatic "pumping" function and drainage patterns were non-invasively and longitudinally imaged using NIRF lymphatic imaging after popliteal lymphadenectomy in mice. In a cohort of mice, B16F10 melanoma was inoculated on the dorsal aspect of the paw 27 days after lymphadenectomy to assess how drainage patterns affect metastasis. RESULTS: NIRF imaging demonstrates that, although lymphatic function and drainage patterns change significantly in early response to popliteal lymph node (PLN removal in mice, these changes are transient and regress dramatically due to a high regenerative capacity of the lymphatics and co-opting of collateral lymphatic pathways around the site of obstruction. Metastases followed the pattern of collateral pathways and could be detected proximal to the site of lymphadenectomy. CONCLUSIONS: Both lymphatic vessel regeneration and co-opting of contralateral vessels occur following lymphadenectomy, with contractile function restored within 13 days, providing a basis for preclinical and clinical investigations to hasten lymphatic repair and restore contractile lymphatic function after surgery to prevent cancer-acquired lymphedema. Patterns of cancer metastasis after lymphadenectomy were altered, consistent with patterns of re-directed lymphatic drainage.

  19. Temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern based on image texture spectrum descriptor

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xi-guo; JIN Ning-de; WANG Zhen-ya; ZHANG Wen-yin

    2009-01-01

    The dynamic image information of typical gas-liquid two-phase flow patterns in vertical upward pipe is captured by a high-speed dynamic camera. The texture spectrum descriptor is used to describe the texture characteristics of the processed images whose content is represented in the form of texture spectrum histogram, and four time-varying characteristic param-eter indexes which represent image texture structure of different flow patterns are extracted. The study results show that the amplitude fluctuation of texture characteristic parameter indexes of bubble flow is lowest and shows very random complex dynamic behavior; the amplitude fluctuation of slug flow is higher and shows intermittent motion behavior between gas slug and liquid slug, and the amplitude fluctuation of churn flow is the highest and shows better periodicity; the amplitude fluctuation of bubble-slug flow is from low to high and oscillating frequence is higher than that of slug flow, and includes the features of both slug flow and bubble flow; the slug-churn flow loses the periodicity of slug flow and churn flow, and the amplitude fluctuation is high. The results indicate that the image texture characteristic parameter indexes of different flow pattern can reflect the flow characteristics of gas-liquid two-phase flow, which provides a new approach to tmderstand the temporal and spatial evolution of flow pattern dynamics.

  20. Maturation of the murine respiratory epithelium: patterns of precursor uptake and temporal behavior of incorporated materials

    Energy Technology Data Exchange (ETDEWEB)

    Webster, E.H. Jr.

    1987-01-01

    The pattern of incorporation of various extracellular matrix material precursors into extracellular matrix materials of developing lung tissues was investigated at stages corresponding to glandular, fetal saccular and postnatal saccular periods. Of the precursors investigated, labeling patterns with /sup 3/H-mannose were the most distinctive, being highly specific for future respiratory terminals. Hence, these materials were investigated for their relationship to normal lung development. The hypothesis tested was that changes in the distribution of extracellular matrix structural glycoproteins plays a directive role in determining which portions of the developing mouse lung will become airway and which will become respiratory.

  1. Inter-provincial migration in Spain: temporal trends and age-specific patterns.

    Science.gov (United States)

    Garcia Coll, A; Stillwell, J

    1999-01-01

    "This paper provides interpretation of the changing patterns of internal migration in Spain at the inter-provincial scale, and new analysis of age-specific migration during the 1980s using a 10% sample of anonymised records from the 1991 census. Schedules of age-specific gross migration rates are constructed and classified according to their shape and level relative to the national schedule, and the relationships between in-migration and out-migration rates are examined for four selected age groups to demonstrate how aggregate patterns of inter-provincial migration conceal a wide diversity of age specific experience."

  2. Spatial and temporal patterns in Arctic river ice breakup revealed by automated ice detection from MODIS imagery

    Science.gov (United States)

    Cooley, Sarah; Pavelsky, Tamlin

    2016-04-01

    The annual spring breakup of river ice has important consequences for northern ecosystems and significant economic implications for Arctic industry and transportation. River ice breakup research is restricted by the sparse distribution of hydrological stations in the Arctic, where limited available data suggests a trend towards earlier ice breakup. The specific climatic mechanisms driving this trend, however, are complex and can vary both regionally and within river systems. Consequently, understanding the response of river ice processes to a warming Arctic requires simultaneous examination of spatial and temporal patterns in breakup timing. Here we present an automated algorithm for river ice breakup detection using MODIS satellite imagery that enables identification of spatial and temporal breakup patterns at large scales. We examine breakup timing on the Mackenzie, Lena, Ob' and Yenisey rivers for the period 2000-2014. First, we split each river into 10 km segments. Next, for each day of the breakup season, we classify each river pixel as snow/ice, mixed ice/water or open water based on MODIS reflectance values and remove all cloud-covered segments using the MODIS cloud product. We then define the breakup date as the first day where the segment is 75% open water. Using this method, we are able to determine breakup dates with a mean uncertainty of +/-1.3 days. We find our remotely sensed breakup dates to be highly correlated to ground breakup dates and the timing of peak discharge. All statistically significant temporal trends in breakup timing are negative, indicating an overall shift towards earlier breakup. Considerable variability in the statistical significance and magnitude of trends along each river suggests that different climatic and physiographic drivers are impacting spatial patterns in breakup. Trends detected on the lower Mackenzie corroborate recent studies indicating weakening ice resistance and earlier breakup timing near the Mackenzie Delta. In

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

    Science.gov (United States)

    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.

  4. Temporal protein expression pattern in intracellular signalling cascade during T-cell activation: A computational study

    Indian Academy of Sciences (India)

    Piyali Ganguli; Saikat Chowdhury; Rupa Bhowmick; Ram Rup Sarkar

    2015-10-01

    Various T-cell co-receptor molecules and calcium channel CRAC play a pivotal role in the maintenance of cell’s functional responses by regulating the production of effector molecules (mostly cytokines) that aids in immune clearance and also maintaining the cell in a functionally active state. Any defect in these co-receptor signalling pathways may lead to an altered expression pattern of the effector molecules. To study the propagation of such defects with time and their effect on the intracellular protein expression patterns, a comprehensive and largest pathway map of T-cell activation network is reconstructed manually. The entire pathway reactions are then translated using logical equations and simulated using the published time series microarray expression data as inputs. After validating the model, the effect of in silico knock down of co-receptor molecules on the expression patterns of their downstream proteins is studied and simultaneously the changes in the phenotypic behaviours of the T-cell population are predicted, which shows significant variations among the proteins expression and the signalling routes through which the response is propagated in the cytoplasm. This integrative computational approach serves as a valuable technique to study the changes in protein expression patterns and helps to predict variations in the cellular behaviour.

  5. How Temporal and Spatial Aspects of Presenting Visualizations Affect Learning about Locomotion Patterns

    Science.gov (United States)

    Imhof, Birgit; Scheiter, Katharina; Edelmann, Jorg; Gerjets, Peter

    2012-01-01

    Two studies investigated the effectiveness of dynamic and static visualizations for a perceptual learning task (locomotion pattern classification). In Study 1, seventy-five students viewed either dynamic, static-sequential, or static-simultaneous visualizations. For tasks of intermediate difficulty, dynamic visualizations led to better…

  6. Spatio-temporal patterns and predictions of phytoplankton assemblages in a subtropical river delta system

    DEFF Research Database (Denmark)

    2016-01-01

    Spatial and seasonal sampling within a subtropical river delta system, the Pearl River Delta (China), provided data to determine seasonal phytoplankton patterns and develop prediction models. The high nutrient levels and frequent water exchanges resulted in a phytoplankton community with greatest...

  7. Retrospective 70 y-spatial analysis of repeated vine mortality patterns using ancient aerial time series, Pléiades images and multi-source spatial and field data

    Science.gov (United States)

    Vaudour, E.; Leclercq, L.; Gilliot, J. M.; Chaignon, B.

    2017-06-01

    For any wine estate, there is a need to demarcate homogeneous within-vineyard zones ('terroirs') so as to manage grape production, which depends on vine biological condition. Until now, the studies performing digital zoning of terroirs have relied on recent spatial data and scant attention has been paid to ancient geoinformation likely to retrace past biological condition of vines and especially occurrence of vine mortality. Is vine mortality characterized by recurrent and specific patterns and if so, are these patterns related to terroir units and/or past landuse? This study aimed at performing a historical and spatial tracing of vine mortality patterns using a long time-series of aerial survey images (1947-2010), in combination with recent data: soil apparent electrical conductivity EM38 measurements, very high resolution Pléiades satellite images, and a detailed field survey. Within a 6 ha-estate in the Southern Rhone Valley, landuse and planting history were retraced and the map of missing vines frequency was constructed from the whole time series including a 2015-Pléiades panchromatic band. Within-field terroir units were obtained from a support vector machine classifier computed on the spectral bands and NDVI of Pléiades images, EM38 data and morphometric data. Repeated spatial patterns of missing vines were highlighted throughout several plantings, uprootings, and vine replacements, and appeared to match some within-field terroir units, being explained by their specific soil characteristics, vine/soil management choices and the past landuse of the 1940s. Missing vines frequency was spatially correlated with topsoil CaCO3 content, and negatively correlated with topsoil iron, clay, total N, organic C contents and NDVI. A retrospective spatio-temporal assessment of terroir therefore brings a renewed focus on some key parameters for maintaining a sustainable grape production.

  8. Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, anovular, suckled, beef cows exposed acutely to bulls

    Directory of Open Access Journals (Sweden)

    Tauck Shaun A

    2010-07-01

    Full Text Available Abstract Background The physiological mechanism by which bulls stimulate resumption of ovarian cycling activity in postpartum, anovular, suckled cows after calving may involve the concurrent activation of the hypothalamic-hypophyseal-ovarian (HPO axis and hypothalamic-hypophyseal-adrenal (HPA axis. Thus, the objectives of this experiment were to determine if characteristics of temporal patterns of cortisol and luteinizing hormone (LH in postpartum, anovular, beef cows are influenced by acute exposure to bulls. The null hypotheses were that daily, temporal characteristics of cortisol and LH concentration patterns do not differ between cows exposed acutely to bulls or steers. Methods Sixteen cows were assigned randomly 67 +/- 4 (+/- SE after calving to be exposed to bulls (EB, n = 8 or steers (ES, n = 8 5 h daily for 9 d (D 0 to 8. Blood samples were collected daily from each cow via jugular catheters at 15-min intervals for 6 h from 1000 to 1600 h each day. The 5-h exposure period began 1 h after the start of the intensive bleeding period. Characteristics of cortisol and LH concentration patterns (mean, baseline, pulse frequency, pulse amplitude, and pulse duration were identified by PULSAR analyses. Results Mean cortisol concentrations decreased (P 0.10 between EB and ES cows. The decrease in mean cortisol concentrations in EB and ES cows from D 0 to D 2 was attributed to cows acclimatizing to intensive blood sampling and handling procedures. Consequently, analyses for characteristics of cortisol and LH concentration patterns included D 2 through 8 only. Cortisol mean and baseline concentrations, and pulse amplitude did not differ (P > 0.10 between EB and ES cows. However, cortisol pulse duration tended to be longer (P = 0.09 and pulse frequency was lower (P = 0.05 in EB than ES cows. LH pulse frequency was greater (P = 0.06 in EB than ES cows. All other characteristics of LH concentration patterns did not differ (P > 0.10 between EB and ES cows

  9. Polycyclic aromatic hydrocarbons (PAHs in the atmospheres of two French alpine valleys: sources and temporal patterns

    Directory of Open Access Journals (Sweden)

    N. Marchand

    2004-01-01

    Full Text Available Alpine valleys represent some of the most important crossroads for international heavy-duty traffic in Europe, but the full impact of this traffic on air quality is not known due to a lack of data concerning these complex systems. As part of the program "Pollution des Vallées Alpines" (POVA, we performed two sampling surveys of polycyclic aromatic hydrocarbons (PAHs in two sensitive valleys: the Chamonix and Maurienne Valleys, between France and Italy. Sampling campaigns were performed during the summer of 2000 and the winter of 2001, with both periods taking place during the closure of the "Tunnel du Mont-Blanc". The first objective of this paper is to describe the relations between PAH concentrations, external parameters (sampling site localization, meteorological parameters, sources, and aerosol characteristics, including its carbonaceous fraction (OC and EC. The second objective is to study the capacity of PAH profiles to accurately distinguish the different emission sources. Temporal evolution of the relative concentration of an individual PAH (CHR and the PAH groups BghiP+COR and BbF+BkF is studied in order to differentiate wood combustion, gasoline, and diesel emissions, respectively. The results show that the total particulate PAH concentrations were higher in the Chamonix valley during both seasons, despite the cessation of international traffic. Seasonal cycles, with higher concentrations in winter, are also stronger in this valley. During winter, particulate PAH concentration can reach very high levels (up to 155 ng.m-3 in this valley during cold anticyclonic periods. The examination of sources shows the impact during summer of heavy-duty traffic in the Maurienne valley and of gasoline vehicles in the Chamonix valley. During winter, Chamonix is characterized by the strong influence of wood combustion in residential fireplaces, even if the temporal evolution of specific PAH ratios are difficult to interpret. Information on sources

  10. The temporal expression pattern of alpha-synuclein modulates olfactory neurogenesis in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Sebastian R Schreglmann

    Full Text Available Adult neurogenesis mirrors the brain´s endogenous capacity to generate new neurons throughout life. In the subventricular zone/ olfactory bulb system adult neurogenesis is linked to physiological olfactory function and has been shown to be impaired in murine models of neuronal alpha-Synuclein overexpression. We analyzed the degree and temporo-spatial dynamics of adult olfactory bulb neurogenesis in transgenic mice expressing human wild-type alpha-Synuclein (WTS under the murine Thy1 (mThy1 promoter, a model known to have a particularly high tg expression associated with impaired olfaction.Survival of newly generated neurons (NeuN-positive in the olfactory bulb was unchanged in mThy1 transgenic animals. Due to decreased dopaminergic differentiation a reduction in new dopaminergic neurons within the olfactory bulb glomerular layer was present. This is in contrast to our previously published data on transgenic animals that express WTS under the control of the human platelet-derived growth factor β (PDGF promoter, that display a widespread decrease in survival of newly generated neurons in regions of adult neurogenesis, resulting in a much more pronounced neurogenesis deficit. Temporal and quantitative expression analysis using immunofluorescence co-localization analysis and Western blots revealed that in comparison to PDGF transgenic animals, in mThy1 transgenic animals WTS is expressed from later stages of neuronal maturation only but at significantly higher levels both in the olfactory bulb and cortex.The dissociation between higher absolute expression levels of alpha-Synuclein but less severe impact on adult olfactory neurogenesis in mThy1 transgenic mice highlights the importance of temporal expression characteristics of alpha-Synuclein on the maturation of newborn neurons.

  11. Modeling and Statistical Analysis of the Spatio-Temporal Patterns of Seasonal Influenza in Israel

    Science.gov (United States)

    Katriel, Guy; Yaari, Rami; Roll, Uri; Stone, Lewi

    2012-01-01

    Background Seasonal influenza outbreaks are a serious burden for public health worldwide and cause morbidity to millions of people each year. In the temperate zone influenza is predominantly seasonal, with epidemics occurring every winter, but the severity of the outbreaks vary substantially between years. In this study we used a highly detailed database, which gave us both temporal and spatial information of influenza dynamics in Israel in the years 1998–2009. We use a discrete-time stochastic epidemic SIR model to find estimates and credible confidence intervals of key epidemiological parameters. Findings Despite the biological complexity of the disease we found that a simple SIR-type model can be fitted successfully to the seasonal influenza data. This was true at both the national levels and at the scale of single cities.The effective reproductive number Re varies between the different years both nationally and among Israeli cities. However, we did not find differences in Re between different Israeli cities within a year. Re was positively correlated to the strength of the spatial synchronization in Israel. For those years in which the disease was more “infectious”, then outbreaks in different cities tended to occur with smaller time lags. Our spatial analysis demonstrates that both the timing and the strength of the outbreak within a year are highly synchronized between the Israeli cities. We extend the spatial analysis to demonstrate the existence of high synchrony between Israeli and French influenza outbreaks. Conclusions The data analysis combined with mathematical modeling provided a better understanding of the spatio-temporal and synchronization dynamics of influenza in Israel and between Israel and France. Altogether, we show that despite major differences in demography and weather conditions intra-annual influenza epidemics are tightly synchronized in both their timing and magnitude, while they may vary greatly between years. The predominance of

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

    Science.gov (United States)

    Saska, P; van der Werf, W; de Vries, E; Westerman, P R

    2008-04-01

    Seed predation is an important component of seed mortality of weeds in agro-ecosystems, but the agronomic use and management of this natural weed suppression is hampered by a lack of insight in the underlying ecological processes. In this paper, we investigate whether and how spatial and temporal variation in activity-density of granivorous ground beetles (Coleoptera: Carabidae) results in a corresponding pattern of seed predation. Activity-density of carabids was measured by using pitfall traps in two organic winter wheat fields from March to July 2004. Predation of seeds (Capsella bursa-pastoris, Lamium amplexicaule, Poa annua and Stellaria media) was assessed using seed cards at the same sites and times. As measured by pitfall traps, carabids were the dominant group of insects that had access to the seed cards. In the field, predation of the four different species of seed was in the order: C. bursa-pastoris>P. annua>S. media>L. amplexicaule; and this order of preference was confirmed in the laboratory using the dominant species of carabid. On average, seed predation was higher in the field interior compared to the edge, whereas catches of carabids were highest near the edge. Weeks with elevated seed predation did not concur with high activity-density of carabids. Thus, patterns of spatial and temporal variation in seed predation were not matched by similar patterns in the abundance of granivorous carabid beetles. The lack of correspondence is ascribed to effects of confounding factors, such as weather, the background density of seeds, the composition of the carabid community, and the phenology and physiological state of the beetles. Our results show that differences in seed loss among weed species may be predicted from laboratory trials on preference. However, predator activity-density, as measured in pitfall traps, is an insufficient predictor of seed predation over time and space within a field.

  13. Temporal and spatial patterning of transgene expression by near-infrared irradiation

    Science.gov (United States)

    Gomez, Leyre; Lopez, Daniel; Arruebo, Manuel; Wilson, Christopher G; Franceschi, Renny T.; Voellmy, Richard; Santamaria, Jesus; Vilaboa, Nuria

    2014-01-01

    We investigated whether near-infrared (NIR) light could be employed for patterning transgene expression in plasmonic cell constructs. Hollow gold nanoparticles with a plasmon surface band absorption peaking at ~750 nm, a wavelength within the so called “tissue optical window”, were used as fillers in fibrin-based hydrogels. These composites, which efficiently transduce NIR photon energy into heat, were loaded with genetically-modified cells that harbor a heat-activated and ligand-dependent gene switch for regulating transgene expression. NIR laser irradiation in the presence of ligand triggered 3-dimensional patterns of transgene expression faithfully matching the illuminated areas of plasmonic cell constructs. This noninvasive technology was proven useful for remotely controlling in vivo the spatiotemporal bioavailability of transgenic vascular endothelial growth factor. The combination of spatial control by means of NIR irradiation along with safe and timed transgene induction presents a high application potential for engineering tissues in regenerative medicine scenarios. PMID:24957294

  14. Quantum noise and spatio-temporal pattern formation in nonlinear optics

    DEFF Research Database (Denmark)

    Bache, Morten

    2002-01-01

    -harmonic field, and the distinct peaks at the critical wave numbers reveal a quantum image. A microscopical model is suggested as a guide to understanding the processes involved in producing a classical pattern. Finally, the quantum nature of the correlations leads to spatial multimode nonclassical light, which......This work concerns analytical and numerical investigations of cavity enhanced x2 frequency conversion processes, specifically second-harmonic generation (SHG). We focus on how the transverse degrees of freedom affect the dynamics, where the interaction between nonlinearity and diffraction gives...... rise to spatially modulated structures, patterns. The two main parts of the thesis are the classical model and the quantum mechanical model, the latter being an extension of the former by including the inherent quantum fluctuations of light. From a theoretical point of view the classical dynamics...

  15. Temporal patterns of diversification in Andean Eois, a species-rich clade of moths (Lepidoptera, Geometridae).

    Science.gov (United States)

    Strutzenberger, P; Fiedler, K

    2011-04-01

    The timing of the origin of present day Neotropical animal diversity is still a matter of debate. For a long time, a preponderance of glacial (i.e. Pleistocene) radiations has been proposed. However, recent data from molecular clock studies indicate a preglacial origin for most of the examined taxa. We performed a fossil-calibrated molecular dating analysis of the genus Eois, which is a major component of one of the world's most diverse assemblages of herbivorous insects. We found that diversification of Eois took place in the Miocene following a pattern best explained by density-dependent diversification. A strong slowdown of diversification towards the present was detected. Diversification of Eois does overlap with increased Andean uplift and diversification of the most commonly used host plant genus Piper. These findings match the patterns found for the majority of Neotropical tetrapods and for three other unrelated, ecologically different lepidopteran genera.

  16. Spatial and temporal patterns of deforestation in Rio Cajari Extrative Reserve, Amapa, Brazil.

    Directory of Open Access Journals (Sweden)

    Claudia Funi

    Full Text Available The Rio Cajarí Extractive Reserve (RCER is a sustainable use protected area located in Southern Amapá state, Brazil. This protected area is home to traditional agro-extractive families, but has been increasingly invaded by commercial agriculture producers. In this work, we test the hypothesis that the RCER implementation has distinctly affected spatial patterns of deforestation and rates of bare soil and secondary forest formation by the social groups occupying the protected area and its surrounding area. Detailed maps of vegetation cover and deforestation were elaborated, based on Landsat TM images from 1991, 1998, 2007 and 2008 and Linear Spectral Mixture Models. Based on an extensive fieldwork, patches were classified according to the agents causing deforestation and characterized with ten explanatory variables. A discriminant function analysis was used to identify homogeneous groups based on the data. Results show increased rates and distinct spatial patterns of deforestation by three groups: extractivists, non traditional commercial agriculture producers, and a less representative group constituted of miners, cattle and timber producers. In all analyzed dates, clearings by the extrativist community presented the highest total area and smaller average sizes and were located in close proximity to villages. Deforestation patches by the non-traditional group were exclusively associated with ombrophilous forests; these presented higher average sizes and proximity indexes, and showed increased aggregation and large cluster formation. No significant differences were observed in deforestation patterns by the three groups inside or outside the reserve.

  17. Deriving spatial and temporal patterns of coastal marsh aggradation from hurricane storm surge marker beds

    Science.gov (United States)

    Hodge, Joshua; Williams, Harry

    2016-12-01

    This study uses storm surge sediment beds deposited by Hurricanes Audrey (1957), Carla (1961), Rita (2005) and Ike (2008) to investigate spatial and temporal changes in marsh sedimentation on the McFaddin National Wildlife Refuge in Southeastern Texas. Fourteen sediment cores were collected along a transect extending 1230 m inland from the Gulf coast. Storm-surge-deposited sediment beds were identified by texture, organic content, carbonate content, the presence of marine microfossils and 137Cs dating. The hurricane-derived sediment beds facilitate assessment of changes in marsh sedimentation from nearshore to inland locations and over decadal to annual timescales. Spatial variation along the transect reflects varying contributions from three prevailing sediment sources: flooding, overwash and organic sedimentation from marsh plants. Over about the last decade, hurricane overwash has been the predominant sediment source for nearshore locations because of large sediment inputs from Hurricanes Rita and Ike. Farther inland, hurricane inputs diminish and sedimentation is dominated by deposition from flood waters and a larger organic component. Temporal variations in sedimentation reflect hurricane activity, changes in marsh surface elevation and degree of compaction of marsh sediments, which is time-dependent. There was little to no marsh sedimentation in the period 2008-2014, firstly because no hurricanes impacted the study area and secondly because overwash sedimentation prior to 2008 had increased nearshore marsh surface elevations by up to 0.68 m, reducing subsequent inputs from flooding. Marsh sedimentation rates were relatively high in the period 2005-2008, averaging 2.13 cm/year and possibly reflecting sediment contributions from Hurricanes Humberto and Gustav. However, these marsh sediments are highly organic and largely uncompacted. Older, deeper marsh deposits formed between 1961 and 2005 are less organic-rich, more compacted and have an average annual

  18. DIFFERENCES IN INTERICTAL PERFUSION PATTERNS BETWEEN REFRACTORY AND NON-REFRACTORY TEMPORAL LOBE EPILEPSIES EVALUATED WITH FAIR AT 3.0T

    Institute of Scientific and Technical Information of China (English)

    Hui You; Jing-jing Lu; Lian-kun Ren; Xiao-zhen Li; Feng Feng; Chun-ling Meng; Zheng-yu Jin

    2006-01-01

    Objective To investigate the difference in interictal perfusion patterns between refractory and non-refractory temporal lobe epilepsies evaluated with flow-sensitive alternating inversion recovery (FAIR) magnetic resonance (MR) sequence.Methods Nine patients with refractory temporal lobe epilepsy,21 patients with non-refractory temporal lobe epilepsy,and 13 normal volunteers underwent FAIR MR scanning.The relative cerebral blood flow (rCBF) in bilateral hemispheres and mesial temporal lobes were measured.And we also calculated the asymmetry index (AI) values.Results The AI values of bilateral hemispheres in refractory and non-refractory epilepsy patients were both significantly different from those of volunteers (P=0.012 and 0.029,respectively).There was significant difference in AI values of bilateral mesial temporal lobes between non-refractory epilepsy patients and volunteers (P=0.049),while no significant difference between refractory epilepsy patients and volunteers.Conclusions The hypoperfusion pattern of interictal refractory temporal lobe epilepsy patients is different from that of non-refractory patients.Although the hypoperfusion tends to extend out of temporal lobes in all patients,the refractory epilepsy patients have a preference of bilateral mesial temporal hypoperfusion,which may be valuable for evaluating prognosis.

  19. A young clade repeating an old pattern: diversity in Nothonotus darters (Teleostei: Percidae) endemic to the Cumberland River.

    Science.gov (United States)

    Keck, Benjamin P; Near, Thomas J

    2010-11-01

    Hypotheses of diversification in eastern North American freshwater fishes have focused primarily on allopatric distributions of species between disjunct highland areas and major river systems. However, these hypotheses do not fully explain the rich diversity of species within highland regions and river systems. Relatively old diversification events at small geographic scales have been observed in the Barcheek Darter subclade that occurs in the Cumberland River drainage (CRD) in Kentucky and Tennessee, United States of America, but it is unknown if this pattern is consistent in other darter subclades. We explored phylogeographic diversity in two species of Nothonotus darters, N. microlepidus and N. sanguifluus, endemic to the CRD to compare phylogenetic patterns between Barcheek Darters and species of Nothonotus. We collected sequence data for a mitochondrial gene (cytb) and three nuclear genes (MLL, S7 and RAG1) from 19 N. microlepidus and 35 N. sanguifluus specimens. Gene trees were estimated using maximum likelihood and Bayesian methods, and a 'species tree' was inferred using a Bayesian method. These trees indicate that species diversity in Nothonotus is underestimated. Five distinct lineages were evident, despite retained ancestral polymorphism and unsampled extirpated populations. Comparison of chronograms for Barcheek Darters and Nothonotus revealed that microendemism resulting from species diversification at small geographic scales in the CRD is a consistent pattern in both old and young darter subclades. Our analyses reveal that geographic isolating mechanisms that result in similar phylogeographic patterns in the CRD are persistent through long expanses of evolutionary time.

  20. Chromosomal organization of simple sequence repeats in the Pacific oyster (Crassostrea gigas): (GGAT)4, (GT)7 and (TA)10 chromosome patterns

    Indian Academy of Sciences (India)

    K. Bouilly; R. Chaves; A. Leitão; A. Benabdelmouna; H. Guedes-Pinto

    2008-08-01

    Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or ribosomal DNA sequences. However, regarding chromosome identification, no study has been conducted with simple sequence repeats (SSRs). FISH was used to probe the physical organization of three particular SSRs, (GGAT)4, (GT)7 and (TA)10 onto metaphase chromosomes of the Pacific oyster, Crassostrea gigas. Hybridization signals were observed in all the SSR probes, but the distribution and intensity of signals varied according to the oligonucleotide repeat. The intercalary, centromeric and telomeric bands were observed along the chromosomes, and for each particular repeat every chromosome pair presented a similar pattern, allowing karyotypic analysis with all the SSRs tested. Our study is the first in mollusks to show the application of SSR in situ hybridization for chromosome identification and karyotyping. This technique can be a useful tool for oyster comparative studies and to understand genome organization in different oyster taxa.

  1. Temporal patterns of moose-vehicle collisions with and without personal injuries.

    Science.gov (United States)

    Niemi, Milla; Rolandsen, Christer M; Neumann, Wiebke; Kukko, Tuomas; Tiilikainen, Raisa; Pusenius, Jyrki; Solberg, Erling J; Ericsson, Göran

    2017-01-01

    Collisions with wild ungulates are an increasing traffic safety issue in boreal regions. Crashes involving smaller-bodied deer species usually lead to vehicle damage only, whereas collisions with a large animal, such as the moose, increase the risk of personal injuries. It is therefore important to understand both the factors affecting the number of moose-vehicle collisions (MVCs) and the underlying causes that turn an MVC into an accident involving personal injuries or fatalities. As a basis for temporal mitigation measures, we examined the annual and monthly variation of MVCs with and without personal injuries. Using a 22-year-long (1990-2011) time series from Finland, we tested the effect of moose population density and traffic volume on the yearly number of all MVCs and those leading to personal injuries. We also examined the monthly distribution of MVCs with and without personal injuries, and contrasted the Finnish findings with collision data from Sweden (years 2008-2010) and Norway (years 2008-2011). Both moose population abundance indices and traffic volume were positively related to the yearly variation in the number of MVCs in Finland. The proportion of MVCs involving personal injuries decreased during our 22-year study period. The monthly distribution of all MVCs peaked during the autumn or winter depending on country, while MVCs involving personal injury peaked in summer. Our study indicates that efforts to reduce MVCs involving personal injuries need to address driver awareness and attitudes during summer, despite most MVCs occurring in autumn or winter.

  2. Temporal patterns in Homalodisca spp. (Hemiptera: Cicadellidae) oviposition on southern California citrus and jojoba.

    Science.gov (United States)

    Al-Wahaibi, Ali K; Morse, Joseph G

    2010-02-01

    A detailed study of the distribution of egg masses of Homalodisca vitripennis (Germar) and H. liturata Ball was done across a 2-yr period (2001-2003) on six host plants in southern California (Marsh grapefruit, Lisbon lemon, Washington navel, Dancy tangerine, rough lemon, and jojoba in Riverside; jojoba in Desert Center). The majority of egg masses in Riverside belonged to H. vitripennis (84-100%), whereas in Desert Center, all Homalodisca egg masses were H. liturata. Oviposition in Riverside occurred in two discrete periods, a late winter and spring period (mid-February to late May), followed by a short interval of very low oviposition during most of June, and then a summer period (late June to late September) followed by a relatively long period of very low oviposition in fall and early winter (October to mid-February). Levels of oviposition during the late winter-spring period were similar to those during the summer despite an observed larger population of adults during the latter period. Moreover, egg clutch size for H. vitripennis was generally greater in spring than during summer and was generally higher than that for H. liturata, especially on Riverside jojoba. Larger egg clutch size was seen on grapefruit than on lemon, navel, and tangerine during summer. There appeared to be temporal host shifts in oviposition; most evident was the shift from relatively high rates of oviposition on lemon and tangerine in late winter-early spring to relatively higher rates of oviposition on grapefruit and navel during summer.

  3. Model-based control of the temporal patterns of intracellular signaling in silico

    Science.gov (United States)

    Murakami, Yohei; Koyama, Masanori; Oba, Shigeyuki; Kuroda, Shinya; Ishii, Shin

    2017-01-01

    The functions of intracellular signal transduction systems are determined by the temporal behavior of intracellular molecules and their interactions. Of the many dynamical properties of the system, the relationship between the dynamics of upstream molecules and downstream molecules is particularly important. A useful tool in understanding this relationship is a methodology to control the dynamics of intracellular molecules with an extracellular stimulus. However, this is a difficult task because the relationship between the levels of upstream molecules and those of downstream molecules is often not only stochastic, but also time-inhomogeneous, nonlinear, and not one-to-one. In this paper, we present an easy-to-implement model-based control method that makes the target downstream molecule to trace a desired time course by changing the concentration of a controllable upstream molecule. Our method uses predictions from Monte Carlo simulations of the model to decide the strength of the stimulus, while using a particle-based approach to make inferences regarding unobservable states. We applied our method to in silico control problems of insulin-dependent AKT pathway model and EGF-dependent Akt pathway model with system noise. We show that our method can robustly control the dynamics of the intracellular molecules against unknown system noise of various strengths, even in the absence of complete knowledge of the true model of the target system. PMID:28275530

  4. Modelling spatial patterns and temporal trends of wildfires in Galicia (NW Spain

    Directory of Open Access Journals (Sweden)

    Jesús Barreal

    2015-08-01

    Full Text Available Aim of study: The goal of this paper is to analyse the importance of the main contributing factors to the occurrence of wildfires. Area of study: We employ data from the region of Galicia during 2001-2010; although the similarities shared between this area and other rural areas may allow extrapolation of the present results. Material and Methods: The spatial dependence is analysed by using the Moran’s I and LISA statistics. We also conduct an econometric analysis modelling both, the number of fires and the relative size of afflicted woodland area as dependent variables, which depend on the climatic, land cover variables, and socio-economic characteristics of the affected areas. Fixed effects and random effect models are estimated in order to control for the heterogeneity between the Forest Districts in Galicia. Main results: Moran’s I and LISA statistics show that there is spatial dependence in the occurrence of Galician wildfires. Econometrics models show that climatology, socioeconomic variables, and temporal trends are also important to study both, the number of wildfires and the burned-forest ratio. Research highlights: We conclude that in addition to direct forest actions, other agricultural or social public plans, can help to reduce wildfires in rural areas or wildland-urban areas. Based on these conclusions, a number of guidelines are provided that may foster the development of better forest management policies in order to reduce the occurrence of wildfires.

  5. Temporal Patterns of Happiness and Information in a Global Social Network: Hedonometrics and Twitter

    Science.gov (United States)

    Dodds, Peter Sheridan; Harris, Kameron Decker; Kloumann, Isabel M.; Bliss, Catherine A.; Danforth, Christopher M.

    2011-01-01

    Individual happiness is a fundamental societal metric. Normally measured through self-report, happiness has often been indirectly characterized and overshadowed by more readily quantifiable economic indicators such as gross domestic product. Here, we examine expressions made on the online, global microblog and social networking service Twitter, uncovering and explaining temporal variations in happiness and information levels over timescales ranging from hours to years. Our data set comprises over 46 billion words contained in nearly 4.6 billion expressions posted over a 33 month span by over 63 million unique users. In measuring happiness, we construct a tunable, real-time, remote-sensing, and non-invasive, text-based hedonometer. In building our metric, made available with this paper, we conducted a survey to obtain happiness evaluations of over 10,000 individual words, representing a tenfold size improvement over similar existing word sets. Rather than being ad hoc, our word list is chosen solely by frequency of usage, and we show how a highly robust and tunable metric can be constructed and defended. PMID:22163266

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

    Science.gov (United States)

    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.

  7. Temporal Patterns of Energy Balance for a Brazilian Tropical Savanna under Contrasting Seasonal Conditions

    Directory of Open Access Journals (Sweden)

    Thiago R. Rodrigues

    2013-01-01

    Full Text Available The savanna of Central Brazil (locally known as cerrado has a long history of land cover change due to human activity. These changes have led to the degradation of cerrado forests and woodlands, leading to the expansion of grass-dominated cerrados and pastures. Thus, the aim of this study was to evaluate the temporal variation in energy flux in areas of degraded, grass-dominated cerrado (locally known as campo sujo in Central Brazil. The amount of Rn partitioned into H declined as monthly rainfall increased and reached a level of approximately 30% during the wet season, while the amount of Rn partitioned into Le increased as monthly rainfall increased and reached a level of approximately 60% during the wet season. As a result, H was significantly higher than Le during the dry season, resulting in a Bowen ratio (β = H/Le of 3-5, while Le was higher than H during the wet season, resulting in a β≈1. These data indicate that the energy partitioning of grass-dominated cerrado is relatively more sensitive to water availability than cerrado woodlands and forests, and have important implications for local and regional energy balance.

  8. National spatial and temporal patterns of notified dengue cases, Colombia 2007-2010.

    Science.gov (United States)

    Restrepo, Angela Cadavid; Baker, Peter; Clements, Archie C A

    2014-07-01

    To explore the variation in the spatial distribution of notified dengue cases in Colombia from January 2007 to December 2010 and examine associations between the disease and selected environmental risk factors. Data on the number of notified dengue cases in Colombia were obtained from the National Institute of Health (Instituto Nacional de Salud - INS) for the period 1 January 2007 through 31 December 2010. Data on environmental factors were collected from the Worldclim website. A Bayesian spatio-temporal conditional autoregressive model was used to quantify the relationship between monthly dengue cases and temperature, precipitation and elevation. Monthly dengue counts decreased by 18% (95% credible interval (CrI): 17-19%) in 2008 and increased by 30% (95% CrI: 28-31%) and 326% (95% CrI: 322-331%) in 2009 and 2010, respectively, compared to 2007. Additionally, there was a significant, nonlinear effect of monthly average precipitation. The results highlight the role of environmental risk factors in determining the spatial of dengue and show how these factors can be used to develop and refine preventive approaches for dengue in Colombia. © 2014 John Wiley & Sons Ltd.

  9. Spatio-Temporal Patterns and Source Identification of Water Pollution in Lake Taihu (China

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-03-01

    Full Text Available Various multivariate methods were used to analyze datasets of river water quality for 11 variables measured at 20 different sites surrounding Lake Taihu from 2006 to 2010 (13,200 observations, to determine temporal and spatial variations in river water quality and to identify potential pollution sources. Hierarchical cluster analysis (CA grouped the 12 months into two periods (May to November, December to the next April and the 20 sampling sites into two groups (A and B based on similarities in river water quality characteristics. Discriminant analysis (DA was important in data reduction because it used only three variables (water temperature, dissolved oxygen (DO and five-day biochemical oxygen demand (BOD5 to correctly assign about 94% of the cases and five variables (petroleum, volatile phenol, dissolved oxygen, ammonium nitrogen and total phosphorus to correctly assign >88.6% of the cases. In addition, principal component analysis (PCA identified four potential pollution sources for Clusters A and B: industrial source (chemical-related, petroleum-related or N-related, domestic source, combination of point and non-point sources and natural source. The Cluster A area received more industrial and domestic pollution-related agricultural runoff, whereas Cluster B was mainly influenced by the combination of point and non-point sources. The results imply that comprehensive analysis by using multiple methods could be more effective for facilitating effective management for the Lake Taihu Watershed in the future.

  10. Temporal and spatial patterns of remotely sensed litterfall in tropical and subtropical forests of Taiwan

    Science.gov (United States)

    Wang, Hsueh-Ching; Lin, Kuo-Chuan; Huang, Cho-ying

    2016-02-01

    Litterfall is important for returning nutrients and carbon to the forest floor, and microbes decompose the litterfall to release CO2 into the atmosphere. Litterfall is a pivotal component in the forest biogeochemical cycle, which is sensitive to climate variability and plant physiology. In this study, we combined field litterfall estimates and time series (2001-2011) climate (the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) and Tropical Rainfall Measuring Mission (TRMM) precipitations) and green vegetation (MODIS photosynthetically active vegetation cover (PV)) variables to estimate regional annual litterfall in tropical/subtropical forests in Taiwan. We found that time series MODIS LST- and PV-derived metrics, the annual accumulated MODIS LST, and coefficient of variation of PV, respectively, but not the TRMM precipitation variables were salient factors for the estimation (r2 = 0.548 and p events might affect the litterfall temporal variation. Overall, the annual litterfall decreased along the elevation gradient, which may reflect a change in the vegetation type. The northeast and northwest facing slopes yielded the highest amount of annual litterfall (≥5.9 Mg ha-1 yr-1), which was in contrast with the southern aspect (5.1 Mg ha-1 yr-1). This variation may be associated with the dryness of the microclimate influenced by solar radiation. This study demonstrates the feasibility of utilizing time series MODIS LST and PV data to predict large-scale field litterfall, which may facilitate large-scale monitoring of biogeochemical cycles in forest ecosystems.

  11. Spatial-Temporal Pattern and Driving Forces of Land Use Changes in Xiamen

    Institute of Scientific and Technical Information of China (English)

    QUAN Bin; CHEN Jian-Fei; QIU Hong-Lie; M.J.M.R(O)MKENS; YANG Xiao-Qi; JIANG Shi-Feng; LI Bi-Cheng

    2006-01-01

    Using Landsat TM data of 1988, 1998 and 2001, the dynamic process of the spatial-temporal characteristics of land use changes during 13 years from 1988 to 2001 in the special economic zone of Xiamen, China was analyzed to improve understanding and to find the driving forces of land use change so that sustainable land utilization could be practiced.During the 13 years cropland decreased remarkably by nearly 11304.95 ha. The areas of rural-urban construction and water body increased by 10152.24 ha and 848.94 ha, respectively. From 1988 to 2001, 52.5% of the lost cropland was converted into rural-urban industrial land. Rapid urbanization contributed to a great change in the rate of cropland land use during these years. Land-reclamation also contributed to a decrease in water body area as well as marine ecological and environmental destruction. In the study area 1) urbanization and industrialization, 2) infrastructure and agricultural intensification, 3) increased affluence of the farming community, and 4) policy factors have driven the land use changes.Possible sustainable land use measures included construction of a land management system, land planning, development of potential land resources, new technology applications, and marine ecological and environmental protection.

  12. Ecology of lichens in boreal coniferous forests with reference to spatial and temporal patterns

    OpenAIRE

    Esseen, Per-Anders

    1983-01-01

    The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. The study sites were located in Medelpad and Väs­terbotten, in the central and northern par...

  13. Understanding the spatial and temporal patterns of copper in-use stocks in China.

    Science.gov (United States)

    Zhang, Ling; Yang, Jiameng; Cai, Zhijian; Yuan, Zengwei

    2015-06-02

    Two approaches are adopted to characterize the comprehensive pattern of the copper in-use stocks in China. The top-down results indicate that both the total amount and the per capita quantity of the stocks have exhibited a significant and increasing trend for the past 60 years, especially since 2000. The top-down results show that the copper stocks increased from a negligible level of less than 1 kg/capita in 1952 to 44 kg/capita in 2012. The total stocks in 2012 are estimated to be 60 Mt by a top-down approach or 48 Mt by a bottom-up calculation. The bottom-up method determines that the largest reservoir is the infrastructure sector, which accounts for approximately 58% of the total stocks. The spatial pattern indicates that the copper in-use stocks are predominately spatially distributed in the eastern regions of China, a feature that is obviously different from the geographical distribution of the primary resources. Analysis on the prospects of stocks shows both the total magnitude and per capita value will continuously increase in the following decade, and enter a relatively stable stage in around 2030, with a maximum value of 106 kg/capita. The results improve the knowledge about closing copper cycles.

  14. Patterns in the composition of microbial communities from a subtropical river: effects of environmental, spatial and temporal factors.

    Directory of Open Access Journals (Sweden)

    Lemian Liu

    Full Text Available Microbes are key components of aquatic ecosystems and play crucial roles in global biogeochemical cycles. However, the spatiotemporal dynamics of planktonic microbial community composition in riverine ecosystems are still poorly understood. In this study, we used denaturing gradient gel electrophoresis of PCR-amplified 16S and 18S rRNA gene fragments and multivariate statistical methods to explore the spatiotemporal patterns and driving factors of planktonic bacterial and microbial eukaryotic communities in the subtropical Jiulong River, southeast China. Both bacterial and microbial eukaryotic communities varied significantly in time and were spatially structured according to upper stream, middle-lower stream and estuary. Among all the environmental factors measured, water temperature, conductivity, PO4-P and TN/TP were best related to the spatiotemporal distribution of bacterial community, while water temperature, conductivity, NOx-N and transparency were closest related to the variation of eukaryotic community. Variation partitioning, based on partial RDA, revealed that environmental factors played the most important roles in structuring the microbial assemblages by explaining 11.3% of bacterial variation and 17.5% of eukaryotic variation. However, pure spatial factors (6.5% for bacteria and 9.6% for eukaryotes and temporal factors (3.3% for bacteria and 5.5% for eukaryotes also explained some variation in microbial distribution, thus inherent spatial and temporal variation of microbial assemblages should be considered when assessing the impact of environmental factors on microbial communities.

  15. SuperFly: a comparative database for quantified spatio-temporal gene expression patterns in early dipteran embryos.

    Science.gov (United States)

    Cicin-Sain, Damjan; Pulido, Antonio Hermoso; Crombach, Anton; Wotton, Karl R; Jiménez-Guri, Eva; Taly, Jean-François; Roma, Guglielmo; Jaeger, Johannes

    2015-01-01

    We present SuperFly (http://superfly.crg.eu), a relational database for quantified spatio-temporal expression data of segmentation genes during early development in different species of dipteran insects (flies, midges and mosquitoes). SuperFly has a special focus on emerging non-drosophilid model systems. The database currently includes data of high spatio-temporal resolution for three species: the vinegar fly Drosophila melanogaster, the scuttle fly Megaselia abdita and the moth midge Clogmia albipunctata. At this point, SuperFly covers up to 9 genes and 16 time points per species, with a total of 1823 individual embryos. It provides an intuitive web interface, enabling the user to query and access original embryo images, quantified expression profiles, extracted positions of expression boundaries and integrated datasets, plus metadata and intermediate processing steps. SuperFly is a valuable new resource for the quantitative comparative study of gene expression patterns across dipteran species. Moreover, it provides an interesting test set for systems biologists interested in fitting mathematical gene network models to data. Both of these aspects are essential ingredients for progress toward a more quantitative and mechanistic understanding of developmental evolution.

  16. Facial Expression Recognition from Video Sequences Based on Spatial-Temporal Motion Local Binary Pattern and Gabor Multiorientation Fusion Histogram

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    2017-01-01

    Full Text Available This paper proposes novel framework for facial expressions analysis using dynamic and static information in video sequences. First, based on incremental formulation, discriminative deformable face alignment method is adapted to locate facial points to correct in-plane head rotation and break up facial region from background. Then, spatial-temporal motion local binary pattern (LBP feature is extracted and integrated with Gabor multiorientation fusion histogram to give descriptors, which reflect static and dynamic texture information of facial expressions. Finally, a one-versus-one strategy based multiclass support vector machine (SVM classifier is applied to classify facial expressions. Experiments on Cohn-Kanade (CK + facial expression dataset illustrate that integrated framework outperforms methods using single descriptors. Compared with other state-of-the-art methods on CK+, MMI, and Oulu-CASIA VIS datasets, our proposed framework performs better.

  17. Mercury concentrations in Atlantic bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, Florida: Patterns of spatial and temporal distribution.

    Science.gov (United States)

    Schaefer, Adam M; Titcomb, Elizabeth Murdoch; Fair, Patricia A; Stavros, Hui-Chen W; Mazzoil, Marilyn; Bossart, Gregory D; Reif, John S

    2015-08-15

    Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue mercury concentrations among the highest reported worldwide. Analysis of total mercury (THg) concentrations in blood collected between 2003 and 2012 showed a significant linear decrease over time (p=0.04). Significant differences in the spatial distribution of THg in resident IRL dolphins were also observed with a general gradient in concentration from north to south. Evaluation of local biogeochemistry and accumulation of mercury in prey species is needed to better understand factors influencing the distribution of Hg in the apex predator. Analyses of temporal and spatial patterns of exposure to THg in this sentinel species may have implications for both ecosystem and public health in the region.

  18. Temporal patterns of dissolved organic matter biodegradability are similar across three rivers of varying size

    Science.gov (United States)

    Coble, Ashley A.; Marcarelli, Amy M.; Kane, Evan S.; Toczydlowski, David; Stottlemyer, Robert

    2016-06-01

    Dissolved organic matter (DOM) composition may be an important determinant of its fate in freshwaters, but little is known about temporal variability in DOM composition and the biodegradability of DOM in northern temperate watersheds. We measured biodegradable dissolved organic carbon (BDOC) via incubation assays and DOM composition using optical indices on 11 dates in three Lake Superior tributaries. Percent BDOC (%BDOC) and BDOC concentrations were seasonally synchronous across these watersheds, despite that they vary in size by orders of magnitude (1.7 to 3400 km2). Relative to %BDOC, BDOC concentrations were more tightly constrained among sites on any given date. BDOC also varied within seasons; for example, %BDOC on two different dates in winter were among the highest (29% and 54%) and lowest (0%) values observed for each site (overall %BDOC range: 0 to 72%). DOM composition varied the most among tributaries during a summer storm event when BDOC (both as percent and concentration) was elevated but was remarkably similar among tributaries during fall, spring, and winter. Multivariate models identified humic-like and tryptophan-like fluorophores as predictors of %BDOC, but DOM composition only described 21% of the overall variation in %BDOC. Collectively, these three rivers exported ~18 Gg C yr-1 as DOC and ~2 Gg C yr-1 as BDOC, which corresponded to 9 to 17% of annual DOC exported in biodegradable form. Our results suggest much of the C exported from these northern temperate watersheds may be biodegradable within 28 days and that large pulses of labile DOM can be exported during storm events and spring snowmelt.

  19. Modeling of the temporal patterns of fluoxetine prescriptions and suicide rates in the United States.

    Directory of Open Access Journals (Sweden)

    Michael S Milane

    2006-06-01

    Full Text Available BACKGROUND: To study the potential association of antidepressant use and suicide at a population level, we analyzed the associations between suicide rates and dispensing of the prototypic SSRI antidepressant fluoxetine in the United States during the period 1960-2002. METHODS AND FINDINGS: Sources of data included Centers of Disease Control and US Census Bureau age-adjusted suicide rates since 1960 and numbers of fluoxetine sales in the US, since its introduction in 1988. We conducted statistical analysis of age-adjusted population data and prescription numbers. Suicide rates fluctuated between 12.2 and 13.7 per 100,000 for the entire population from the early 1960s until 1988. Since then, suicide rates have gradually declined, with the lowest value of 10.4 per 100,000 in 2000. This steady decline is significantly associated with increased numbers of fluoxetine prescriptions dispensed from 2,469,000 in 1988 to 33,320,000 in 2002 (r(s = -0.92; p < 0.001. Mathematical modeling of what suicide rates would have been during the 1988-2002 period based on pre-1988 data indicates that since the introduction of fluoxetine in 1988 through 2002 there has been a cumulative decrease in expected suicide mortality of 33,600 individuals (posterior median, 95% Bayesian credible interval 22,400-45,000. CONCLUSIONS: The introduction of SSRIs in 1988 has been temporally associated with a substantial reduction in the number of suicides. This effect may have been more apparent in the female population, whom we postulate might have particularly benefited from SSRI treatment. While these types of data cannot lead to conclusions on causality, we suggest here that in the context of untreated depression being the major cause of suicide, antidepressant treatment could have had a contributory role in the reduction of suicide rates in the period 1988-2002.

  20. Spatio-temporal patterns in pollination of deceptive Aristolochia rotunda L. (Aristolochiaceae).

    Science.gov (United States)

    Oelschlägel, B; von Tschirnhaus, M; Nuss, M; Nikolić, T; Wanke, S; Dötterl, S; Neinhuis, C

    2016-11-01

    Pollination success of highly specialised flowers is susceptible to fluctuations of the pollinator fauna. Mediterranean Aristolochia rotunda has deceptive trap flowers exhibiting a highly specialised pollination system. The sole pollinators are kleptoparasitic flies in search of food. This study investigates these pollinators on a spatio-temporal scale and the impact of weather conditions on their availability. Two potential strategies of the plants to cope with pollinator limitation, i.e. autonomous selfing and an increased floral life span, were tested. A total of 6156 flowers were investigated for entrapped pollinators in 10 Croatian populations. Availability of the main pollinator was correlated to meteorological data. Artificial pollination experiments were conducted and the floral life span was recorded in two populations according to pollinator availability. Trachysiphonella ruficeps (Chloropidae) was identified as dominant pollinator, along with less abundant species of Chloropidae, Ceratopogonidae and Milichiidae. Pollinator compositions varied among populations. Weather conditions 15-30 days before pollination had a significant effect on availability of the main pollinator. Flowers were not autonomously selfing, and the floral life span exhibited considerable plasticity depending on pollinator availability. A. rotunda flowers rely on insect pollen vectors. Plants are specialised on a guild of kleptoparasitic flies, rather than on a single species. Pollinator variability may result in differing selection pressures among populations. The availability/abundance of pollinators depends on weather conditions during their larval development. Flowers show a prolonged trapping flower stage that likely increases outcrossing success during periods of pollinator limitation. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Spatial and Temporal Patterns of Soil Carbon and Nitrogen Storage Following Woody Plant Encroachment Into Grassland

    Science.gov (United States)

    Archer, S.; Boutton, T. W.; Wu, X. B.; Liu, F.; Bai, E.

    2004-12-01

    Encroachment of woody plants into drylands during the past century may have significantly influenced the terrestrial carbon cycle. However, the magnitude and sign of change in soil organic carbon (SOC) pools accompanying this vegetation change is highly uncertain, ranging from positive to neutral to negative. Some of the controversy over woody plant impacts on SOC pools may be an artifact how soil properties determined from point samples are area-weighted and extrapolated. If there is substantial spatial structure in properties of soils associated with woody and herbaceous communities, extrapolations from limited point samples that do not account for this may over- or underestimate actual SOC pools. To test this possibility, we quantified near surface (0-15 cm) soil properties (bulk density, SOC, total N [TN], root biomass) at seven locations along transects extending from the tree bole to canopy edge and into adjoining herbaceous zones in replicated woody communities known to have developed on grasslands over the past 100 y. A strong gradient was found to occur: root biomass, SOC, and TN decreased exponentially with distance from tree boles, while bulk density increased. These spatial changes are consistent with temporal changes expected to occur as shrub establish and their canopies grow through time. Given the strong spatial structure of the data, it appears that area-weighted extrapolations of SOC based on near-bole samples would overestimate woody plant influences, whereas sampling soils away from boles would tend to underestimate impacts. Implications for sampling strategies to efficiently and effectively represent this non-linear spatial variation will be discussed.

  2. Spatio-temporal patterns of under-five mortality in Matlab HDSS in rural Bangladesh

    Directory of Open Access Journals (Sweden)

    Nurul Alam

    2010-08-01

    Full Text Available Background: Knowledge of spatial and temporal distributions of mortality and morbidity is important to prioritise areas for adjusting the public health system where people need services most. A Health and Demographic Surveillance System (HDSS plays an important role where accurate national vital events are not available in identifying areas and periods with excess mortality risks. Methods: The HDSS in Matlab, a rural area of Bangladesh, provided data on yearly number of deaths and children aged below 5 years for each of 90 villages during 1998–2007, along with village location points, longitudes and latitudes. Kulldorff's space–time scan statistic was used to identify villages and periods that experienced high mortality risks in the HDSS area with a statistical significance of p<0.001. Logistic regression was conducted to examine if village-level education and economic status explained village-level mortality risks. Results: There were 3,434 deaths among children aged below 5 years in the HDSS area during 1998–2007 with an average yearly rate of 13 deaths per 1,000 under-five child-years. The mortality rate showed a declining trend with high concentration in 1998–2002, but not in 2003–2007. Two clusters of villages had significantly higher mortality risks in 1998–2002, but not later, and the mortality risks in the high-risk clusters reduced little, but remained significant after controlling for adult education and economic status at village level. Conclusions: Spatial clustering of childhood mortality observed during 1998–2002 had disappeared in subsequent years with a decline in mortality rates. Space–time scanning helps identify high-risk areas and periods to enhance public health actions.

  3. Microbial colonization induces dynamic temporal and spatial patterns of NF-κB activation in the zebrafish digestive tract

    Science.gov (United States)

    Kanther, Michelle; Sun, Xiaolun; Mühlbauer, Marcus; Mackey, Lantz C.; Flynn, Edward J.; Bagnat, Michel; Jobin, Christian; Rawls, John F.

    2011-01-01

    Background & Aims The nuclear factor κ-light-chain enhancer of activated B cells (NF-κB) transcription factor pathway is activated in response to diverse microbial stimuli to regulate expression of genes involved in immune responses and tissue homeostasis. However, the temporal and spatial activation of NF-κB in response to microbial signals have not been determined in whole living organisms, and the molecular and cellular details of these responses are not well understood. We used in vivo imaging and molecular approaches to analyze NF-κB activation in response to the commensal microbiota in transparent gnotobiotic zebrafish. Methods We used DNA microarrays, in situ hybridization, and quantitative reverse transcription PCR analyses to study the effects of the commensal microbiota on gene expression in gnotobiotic zebrafish. Zebrafish PAC2 and ZFL cells were used to study the NF-κB signaling pathway in response to bacterial stimuli. We generated transgenic zebrafish that express enhanced green fluorescent protein under transcriptional control of NF-κB, and used them to study patterns of NF-κB activation during development and microbial colonization. Results Bacterial stimulation induced canonical activation of the NF-κB pathway in zebrafish cells. Colonization of germ-free transgenic zebrafish with a commensal microbiota activated NF-κB and led to up-regulation of its target genes in intestinal and extra-intestinal tissues of the digestive tract. Colonization with the bacterium Pseudomonas aeruginosa was sufficient to activate NF-κB, and this activation required a functional flagellar apparatus. Conclusions In zebrafish, transcriptional activity of NF-κB is spatially and temporally regulated by specific microbial factors. The observed patterns of NF-κB-dependent responses to microbial colonization indicate that cells in the gastrointestinal tract respond robustly to the microbial environment. PMID:21439961

  4. The spatial-temporal pattern and influencing factors of negative air ions in urban forests, Shanghai, China

    Institute of Scientific and Technical Information of China (English)

    Hong Liang; Xiaoshuang Chen; Junguang Yin; Liangjun Da

    2014-01-01

    Negative air ions are natural components of the air we breathe. Forests are the main continuous natural source of negative air ions (NAI). The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations (NAIC) showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles (TSP) were the dominant determining factor of NAIC in sum-mer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai’s ongoing urbanization and its impacts on the environment. It is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Fur-thermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to the effect of urbanization on NAIC.

  5. [Spatio-temporal pattern of larvae and eggs of gastrointestinal nematodes in cattle pastures in Veracruz, Mexico].

    Science.gov (United States)

    Flota-Bañuelos, Carolina; Martínez, Imelda; López-Collado, José; Vargas Mendoza, Mónica; González Hernández, Hector; Fajersson, Pernilla

    2013-12-01

    The spatial and temporal distribution of gastrointestinal nematodes of cattle has been little studied in Mexico. Previous studies have described periods of higher larval presence, vertical and horizontal migration in grasslands, and the frequency of adult nematodes; as well as the effect of pasture trichomes on the migration and survival of Haemonchus larvae. The aim of this study was to determine the time-space layout and spread of gastrointestinal nematode larvae on pasture, and to estimate the effect of ivermectin applied to cattle on the time-dependent abundance of their eggs in a ranch in Veracruz. To determine the spatio-temporal arrangement, monthly morning grass samples were obtained from 30 sampling points from July 2008 to June 2009. Third stage larvae (L3) from each point were counted, and aggregation patterns were estimated through variance/mean and negative binomial K indices. Additionally, the number of eggs per gram in cattle feces was determined, from samples with (CI) and without ivermectin (SI), using standard techniques. A total of 20 276 L(3) larvae were recovered in the pasture, of which an 80% corresponded to Haemonchus contortus. The highest nematode density with more than 5 000L(3)/kgDM was detected in October 2008, and the lowest in February and March 2009. The L3 showed an aggregated spatial pattern of varying intensity throughout the year. The number of eggs in the stool was not reduced with the ivermectin application to cattle, which suggested a failure of control. However, the highest parasite loads were observed from July to November 2008. We concluded that the application of ivermectin was not effective to control nematodes eggs, and that L3 populations fluctuated on pasture for ten months, providing an infection source to grazing animals afterwards.

  6. Temporal patterns of glacial lake evolution in high-mountain environments

    Science.gov (United States)

    Mergili, Martin; Emmer, Adam; Viani, Cristina; Huggel, Christian

    2017-04-01

    Lakes forming at the front of retreating glaciers are characteristic features of high-mountain areas in a warming climate. Typically, lakes shift from the proglacial phase (lake is in direct contact with glacier) to a glacier-detached (no direct contact) and finally to a non-glacial phase (lake catchment is completely deglaciated) of lake evolution. Apart from changing glacier-lake interactions, each stage is characterized by particular features of lake growth, and by the lake's susceptibility to sudden drainage (lake outburst flood). While this concept appears to be valid globally, some mountain areas are rich in dynamically evolving proglacial lakes, while in others most lakes have already shifted to the glacier-detached or even non-glacial phase. In the present contribution we (i) explore and quantify the history of glacial lake formation and evolution over the past up to 70 years; (ii) assess the current situation of selected contrasting mountain areas (eastern and western European Alps, southern and northern Pamir, Cordillera Blanca); and (iii) link the patterns of lake evolution to the prevailing topographic and glaciological characteristics in order to improve the understanding of high-mountain geoenvironmental change. In the eastern Alps we identify only very few lakes in the proglacial stage. While many lakes appeared and dynamically evolved until the 1980s between 2550 m and 2800 m asl, most of them have lost glacier contact until the 2000s, whereas very few new proglacial lakes appeared at the same time. Even though a similar trend is observed in the higher western Alps, a more dynamic glacial lake evolution is observed there. The arid southern Pamir is characterized by a high number of proglacial lakes, mainly around 4500 m asl. There is strong evidence that glacial lake evolution is, after a highly dynamic phase between the 1970s and approx. 2000, decelerating. Few proglacial lakes exist in the higher and more humid, heavily glacierized northern Pamir

  7. Spatial temporal patterns for action-oriented perception in roving robots

    CERN Document Server

    Patanè, Luca

    2014-01-01

    This book presents the result of a joint effort from different European Institutions within the framework of the EU funded project called SPARK II, devoted to device an insect brain computational model, useful to be embedded into autonomous robotic agents.  Part I reports the biological background on Drosophila melanogaster with particular attention to the main centers which are used as building blocks for the implementation of the insect brain computational model.  Part II  reports the mathematical approach to model the Central Pattern Generator used for the gait generation in a six-legged robot. Also the Reaction-diffusion principles in non-linear lattices are exploited to develop a compact internal representation of a dynamically changing environment for behavioral planning. In Part III  a software/hardware framework, developed to integrate the insect brain computational model in a simulated/real robotic platform, is illustrated. The different robots used for the experiments are also described.  Moreo...

  8. Temporal Patterns of Glyphosate Leaching at a Loamy Agricultural Field in Denmark

    DEFF Research Database (Denmark)

    Nørgaard, Trine; Møldrup, Per; Olsen, Preben

    2013-01-01

    applications in combination with the effect of precipitation events, drain water runoff, soil water content at 25 cm soil depth, management, and particle leaching patterns, and compares this with monitored field-scale glyphosate and AMPA leaching to a tile drainage system. Preliminary findings indicate...... that there is an accumulation of glyphosate and AMPA in the soil after the successive applications of glyphosate, as the level of the peaking concentrations right after applications increases. Furthermore, large precipitation events with subsequent high drain water runoff together with management, especially plowing...... and harvesting, trigger the leaching of mobile colloids, glyphosate, and AMPA. As a likely consequence, glyphosate has occasionally been detected in groundwater monitoring wells installed at the location down to 3.5-4.5 m depth in concentrations exceeding the EU drinking water quality criterion....

  9. A Naturalistic Examination of the Temporal Patterns of Affect and Eating Disorder Behaviors in Anorexia Nervosa

    Science.gov (United States)

    Lavender, Jason M.; Utzinger, Linsey M.; Crosby, Ross D.; Goldschmidt, Andrea B.; Ellison, Jo; Wonderlich, Stephen A.; Engel, Scott G.; Mitchell, James E.; Crow, Scott J.; Peterson, Carol B.; Le Grange, Daniel

    2017-01-01

    Objective Evidence supports the presence of significant variability in the timing of affective experiences and eating disorder (ED) behaviors across ED populations. This study examined the naturalistic timing of affective states and ED behaviors in anorexia nervosa (AN). Methods Women (N = 118) with full or subthreshold DSM-IV AN completed two weeks of ecological momentary assessment (EMA) involving self-reports of affect and ED behaviors. Patterns of positive affect, negative affect, and tension/anxiety across hours of the day and days of the week were examined using linear mixed models. Variation in ED behavior occurrence (i.e., binge eating, vomiting, exercise, meal skipping, and self-weighing) across hours of the day and days of the week was examined using general estimating equations. Results Results revealed significant variation in tension/anxiety across hours of the day; there were no significant associations between time of day and negative or positive affect. All affective variables significantly varied across days of the week, with both negative affect and tension/anxiety highest in the middle of the week and lowest on the weekends. The ED behaviors all significantly varied across hours of the day, with binge eating and vomiting most common in later hours, exercise and self-weighing most common in earlier hours, and meal skipping most common at times corresponding to breakfast and lunch. ED behaviors did not significantly vary across days of the week. Conclusion The significant patterns of variation in the timing of affective experiences and ED behaviors may have utility in informing theories and interventions for AN. PMID:26282336

  10. Temporal patterns of methane emissions from wetland rice fields treated by different modes of N application

    Science.gov (United States)

    Wassmann, R.; Neue, H. U.; Lantin, R. S.; Aduna, J. B.; Alberto, M. C. R.; Andales, M. J.; Tan, M. J.; van der G