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Dynamic Changes in the Mental Rotation Network Revealed by Pattern Recognition Analysis of fMRI Data

MOURAO-MIRANDA, Janaina; ECKER, Christine; SATO, Joao R.; BRAMMER, Michael
Fonte: M I T PRESS Publicador: M I T PRESS
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
464.7053%
We investigated the temporal dynamics and changes in connectivity in the mental rotation network through the application of spatio-temporal support vector machines (SVMs). The spatio-temporal SVM [Mourao-Miranda, J., Friston, K. J., et al. (2007). Dynamic discrimination analysis: A spatial-temporal SVM. Neuroimage, 36, 88-99] is a pattern recognition approach that is suitable for investigating dynamic changes in the brain network during a complex mental task. It does not require a model describing each component of the task and the precise shape of the BOLD impulse response. By defining a time window including a cognitive event, one can use spatio-temporal fMRI observations from two cognitive states to train the SVM. During the training, the SVM finds the discriminating pattern between the two states and produces a discriminating weight vector encompassing both voxels and time (i.e., spatio-temporal maps). We showed that by applying spatio-temporal SVM to an event-related mental rotation experiment, it is possible to discriminate between different degrees of angular disparity (0 degrees vs. 20 degrees, 0 degrees vs. 60 degrees, and 0 degrees vs. 100 degrees), and the discrimination accuracy is correlated with the difference in angular disparity between the conditions. For the comparison with highest accuracy (08 vs. 1008)...

Aparecimento de lesões decorrentes do desgaste ou não de dentes de leitões na maternidade: efeitos no comportamento e desempenho de suínos em diferentes fases da produção; Appearance of injuries resulting from detrition or no teeth piglets in maternity: effects on behavior and performance of pigs in different phases of production

Ricci, Gisele Dela
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/06/2015 Português
Relevância na Pesquisa
382.70523%
O bem-estar animal tem sido foco de discussões referindo-se ao modo como os animais são tratados dentro dos confinamentos. A prática do desgaste dos dentes é realizada no segundo dia de nascimento dos lactentes, buscando reduzir lesões cutâneas nos leitões e no aparelho mamário das matrizes. O incorreto desgaste pode propiciar lesões e enfermidades que deprimem a imunidade e o desenvolvimento do leitão. Questiona-se, no entanto, a possibilidade de manter os dentes íntegros, uma vez que o corte e ou desgaste dos dentes podem aumentar a mortalidade na maternidade, reduzindo a habilidade do leitão em competir pelos tetos e consequentemente ganhar peso. A avaliação da estabilidade das instalações diante da qualidade de vida dos animais confinados tem recebido atenção notória nos últimos anos, surgindo à necessidade de analise do comportamento dos suínos diante dos procedimentos realizados nos primeiros dias de nascimento visando compreender e implantar aqueles que induzam ao menor sofrimento aos suínos contemplando simultaneamente o desempenho e bem-estar animal. Neste estudo foram avaliadas a presença e ausência de lesões nas faces dos leitões e nos tetos das matrizes a partir dos tratamentos de desgaste ou integridade dos dentes dos lactentes na fase de maternidade e a influencia destes tratamentos no comportamento...

Running behavior and its energy cost in mice selectively bred for high voluntary locomotor activity

Rezende, Enrico L.; Gomes, Fernando R.; Chappell, Mark A.; Garland Jr., Theodore
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 662-679
Português
Relevância na Pesquisa
482.04727%
Locomotion is central to behavior and intrinsic to many fitnesscritical activities (e.g., migration, foraging), and it competes with other life-history components for energy. However, detailed analyses of how changes in locomotor activity and running behavior affect energy budgets are scarce. We quantified these effects in four replicate lines of house mice that have been selectively bred for high voluntary wheel running (S lines) and in their four nonselected control lines (C lines). We monitored wheel speeds and oxygen consumption for 24-48 h to determine daily energy expenditure (DEE), resting metabolic rate (RMR), locomotor costs, and running behavior (bout characteristics). Daily running distances increased roughly 50%-90% in S lines in response to selection. After we controlled for body mass effects, selection resulted in a 23% increase in DEE in males and a 6% increase in females. Total activity costs (DEE - RMR) accounted for 50%-60% of DEE in both S and C lines and were 29% higher in S males and 5% higher in S females compared with their C counterparts. Energetic costs of increased daily running distances differed between sexes because S females evolved higher running distances by running faster with little change in time spent running...

Observação e controlo da segurança estrutural de barragens de betão: utilização integrada de modelos numéricos e de modelos de separação de efeitos

Mendes, Emanuel Jesus Guerreiro
Fonte: Instituto Politécnico de Lisboa Publicador: Instituto Politécnico de Lisboa
Tipo: Dissertação de Mestrado
Publicado em /11/2014 Português
Relevância na Pesquisa
790.25836%
Atualmente, o controlo da segurança estrutural de barragens de betão em fase de exploração tende a apoiar-se em sistemas de monitorização que permitem a recolha automática e a recolha manual dos dados da observação. Estes dados são armazenados computacionalmente em bases que podem ser acedidas via web através de sistemas informáticos (web systems) especificamente desenvolvidos para apoiar as atividades de gestão e controlo da segurança. Estes sistemas informáticos são parte integrante dos sistemas de monitorização de barragens e devem: i) ser dotados de interfaces gráficas que permitam uma grande interatividade; ii) permitir armazenar e consultar os dados da observação sob a forma numérica; iii) permitir a visualização gráfica das diversas grandezas observadas ao longo do tempo. Devem também disponibilizar módulos para: i) analisar a evolução ao longo do tempo das grandezas observadas com base em modelos de separação de efeitos (MSE); ii) utilizar modelos de elementos finitos (MEF) para simular o comportamento observado, sob a ação das principais solicitações; e iii) comparar as observações e os resultados dos MSE e MEF. Neste sentido...

Plano de segurança alimentar em venda avulso de produtos de mercearia

Amaro, Paula Cristina Catalão Rodrigues da Costa
Fonte: Universidade de Lisboa. Faculdade de Medicina Veterinária Publicador: Universidade de Lisboa. Faculdade de Medicina Veterinária
Tipo: Dissertação de Mestrado
Publicado em 28/04/2014 Português
Relevância na Pesquisa
468.12203%
Dissertação de Mestrado em Segurança Alimentar; Com este trabalho pretendeu-se desenvolver técnicas adequadas para a venda de produtos de mercearia avulso, tentando responder a uma necessidade que se tem manifestado por parte dos consumidores e das alterações dos seus hábitos de compra, face às novas realidades socioeconómicas. Assim, e uma vez que esta forma de venda foi sendo descontinuada ao longo do tempo e surge hoje como uma nova realidade, tentou-se perceber que procedimentos seriam os mais adequados para cumprir todos os requisitos essenciais para manter a segurança dos alimentos e a qualidade dos produtos expostos. Analisaram-se os procedimentos já aplicados em loja sugerindo-se algumas alterações, nomeadamente ao nível de procedimentos de limpeza e no equipamento utilizado. Observou-se o comportamento dos consumidores, constatando-se que também aqui é necessário intervir com ações de sensibilização para esta nova realidade. Realizaram-se provas organoléticas para aferir quanto ao tempo de exposição adequado dos produtos e, de uma forma geral, a aceitação dos mesmos pelos provadores após 60 dias foi bastante boa. Por último, efetuaram-se análises laboratoriais para contagem de fungos e deteção de esporos nos produtos...

Preferência por produtos verdes : qualidades assinaladas acerca dos consumidores

Gomes, Marta Filipa Baptista
Fonte: Instituto Universitário de Lisboa Publicador: Instituto Universitário de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2011 Português
Relevância na Pesquisa
385.42492%
Mestrado em Marketing / JEL Classification System: M31 - Marketing; C12 - Hypothesis Testing: General; Ao longo dos últimos anos as preocupações com o ambiente têm sido cada vez maiores, devido à crescente degradação que este tem vindo a sofrer ao longo do tempo. E, por isso, tem sido cada vez mais relevante perceber o porquê dos consumidores comprarem ou não produtos amigos do ambiente, visto este ser um comportamento relevante de forma a ajudar a preservar o ambiente, e que pode e deve ser incentivado. Assim, com base na revisão de literatura realizada, pode-se afirmar que a realização de um comportamento pro-ambiental sinaliza algumas qualidades acerca das pessoas que os colocam em prática (costly signaling perspective), qualidades estas que ainda não está claro quais são, e que isso pode influenciar o comportamento das pessoas relativamente aos produtos verdes. Deste modo, o estudo realizado observou a influência que duas qualidades, inteligência e estar na moda, têm sobre a preferência por produtos verdes. Foi possível observar que a existência de um motivo de inteligência leva a que as pessoas revelem maior preferência pelo produto verde quando comparado com o produto convencional, e que o mesmo não acontece com o motivo de estar na moda...

Observation and quantification of individual microtubule behavior in vivo: microtubule dynamics are cell-type specific

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 02/02/1993 Português
Relevância na Pesquisa
385.44383%
Recent experiments have demonstrated that the behavior of the interphase microtubule array is cell-type specific: microtubules in epithelial cells are less dynamic than microtubules in fibroblasts (Pepper-kok et al., 1990; Wadsworth and McGrail, 1990). To determine which parameters of microtubule dynamic instability behavior are responsible for this difference, we have examined the behavior of individual microtubules in both cell types after injection with rhodamine-labeled tubulin subunits. Individual microtubules in both cell types were observed to grow, shorten, and pause, as expected. The average amount of time microtubules remained within the lamellae of CHO fibroblasts, measured from images acquired at 10-s intervals, was significantly shorter than the average amount of time microtubules remained within lamellae of PtK1 epithelial cells. Further analysis of individual microtubule behavior from images acquired at 2-s intervals reveals that microtubules in PtK1 cells undergo multiple brief episodes of growth and shortening, resulting in little overall change in the microtubule network. In contrast, microtubules in lamellae of CHO fibroblasts are observed to undergo fewer transitions which are of longer average duration, resulting in substantial changes in the microtubule network over time. A small subset of more stable microtubules was also detected in CHO fibroblasts. Quantification of the various parameters of dynamic instability behavior from these sequences demonstrates that the average rates of both growth and shortening are significantly greater for the majority of microtubules in fibroblasts than for microtubules in epithelial cells (19.8 +/- 10.8 microns/min...

Low Incidences of Human Immunodeficiency Virus and Hepatitis C Virus Infection and Declining Risk Behaviors in a Cohort of Injection Drug Users in Chennai, India

Solomon, Sunil Suhas; Celentano, David D.; Srikrishnan, Aylur K.; Vasudevan, Canjeevaram K.; Murugavel, Kalilapuri G.; Iqbal, Syed H.; Anand, Santhanam; Kumar, Muniratnam Suresh; Latkin, Carl; Solomon, Suniti; Mehta, Shruti H.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
383.11312%
The authors characterized human immunodeficiency virus (HIV) and hepatitis C virus (HCV) incidence and prospective changes in self-reported risk behavior over 2 years among 1,158 injection drug users (IDUs) recruited in Chennai, India, in 2005–2006. At baseline, HIV prevalence was 25.3%, and HCV prevalence was 54.5%. Seropositive persons with prevalent HIV infection were used to estimate baseline HIV incidence by means of the Calypte HIV-1 BED Incidence EIA (Calypte Biomedical Corporation, Portland, Oregon). Longitudinal HIV and HCV incidence were measured among 865 HIV-negative IDUs and 519 HCV antibody-negative IDUs followed semiannually for 2 years. Participants received pre- and posttest risk reduction counseling at each visit. Estimated HIV incidence at baseline was 2.95 per 100 person-years (95% confidence interval (CI): 1.21, 4.69) by BED assay; observed HIV incidence over 1,262 person-years was 0.48 per 100 person-years (95% CI: 0.17, 1.03). HCV incidence over 645 person-years was 1.71 per 100 person-years (95% CI: 0.85, 3.03). Self-reported risk behaviors declined significantly over time, from 100% of participants reporting drug injection at baseline to 11% at 24 months. In this cohort with high HIV and HCV prevalence at enrollment...

COMPUTER-ASSISTED MEASUREMENT OF WOUND SIZE ASSOCIATED WITH SELF-INJURIOUS BEHAVIOR

Wilson, David M.; Iwata, Brian A.; Bloom, Sarah E.
Fonte: The Society for the Experimental Analysis of Behavior Publicador: The Society for the Experimental Analysis of Behavior
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
Relevância na Pesquisa
466.31418%
We evaluated an inexpensive, efficient, and noninvasive technique for measuring tissue damage produced by self-injurious behavior (SIB). The technique involved computerized measurement of wound surface area (WSA) based on digital photographs. In Study 1, we compared photographic measurement to a more commonly used procedure, transparency measurement, in estimating WSA of 20 wound models. Results showed that both methods were reliable and that there was a high degree of correspondence between the 2 sets of measures. In Study 2, we compared photographic WSA measures to direct-observation measures in documenting changes over time in the SIB exhibited by a woman with Prader-Willi syndrome. Results showed that increases and decreases in observed SIB during baseline and treatment conditions corresponded with changes in WSA measures, indicating that the computer-assisted photographic technique may be useful as a corroborative measure or as a primary measure when direct observation of SIB is not feasible.

Chronic variable stress in fathers alters paternal and social behavior but not pup development in the biparental California mouse (Peromyscus californicus)

Harris, Breanna N.; de Jong, Trynke R.; Yang, Vanessa; Saltzman, Wendy
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
390.51164%
Stress and chronically elevated glucocorticoid levels have been shown to disrupt parental behavior in mothers; however, almost no studies have investigated corresponding effects in fathers. The present experiment tested the hypothesis that chronic variable stress inhibits paternal behavior and consequently alters pup development in the monogamous, biparental California mouse (Peromyscus californicus). First-time fathers were assigned to one of three experimental groups: chronic variable stress (CVS, n=8), separation control (SC, n=7), or unmanipulated control (UC, n=8). The CVS paradigm (3 stressors per day for 7 days) successfully stressed mice, as evidenced by increased baseline plasma corticosterone concentrations, increased adrenal mass, decreased thymus mass, and a decrease in body mass over time. CVS altered paternal and social behavior of fathers, but major differences were observed only on day 6 of the 7-day paradigm. At that time point, CVS fathers spent less time with their pairmate and pups, and more time autogrooming, as compared to UC fathers; SC fathers spent more time behaving paternally and grooming the female mate than CVS and UC fathers. Thus, CVS blocked the separation-induced increase in social behaviors observed in the SC fathers. Nonetheless...

Evaluation of an Implementation Initiative for Embedding Dialectical Behavior Therapy in Community Settings

Herschell, Amy D.; Lindhiem, Oliver J.; Kogan, Jane N.; Celedonia, Karen L.; Stein, Bradley D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
380.9117%
We examined the effectiveness of Dialectical Behavior Therapy (DBT) training in community-based agencies. Data were gathered at four time points over a two-year period from front-line mental health therapists (N = 64) from 10 community-based agencies that participated in a DBT implementation initiative. We examined change on therapist attitudes towards consumers with Borderline Personality Disorder (BPD), confidence in the effectiveness of DBT, and use of DBT model components. All measures were self-report. Participating in DBT training resulted in positive changes over time, including improved therapist attitudes toward consumers with BPD, improved confidence in the effectiveness of DBT, and increased use of DBT components. Therapists who had the lowest baseline scores on the study outcomes had the greatest self-reported positive change in outcomes over time. Moreover, there were notable positive correlations in therapist characteristics; therapists who had the lowest baseline attitudes towards individuals with BPD, confidence in the effectiveness of DBT, or who were least likely to use DBT modes and components were the therapists who had the greatest reported increase over time in each respective area. DBT training with ongoing support resulted in changes not commonly observed in standard training approaches typically used in community settings. It is encouraging to observe positive outcomes in therapist self-reported skill...

Promoting prosocial behavior and self-regulatory skills in preschool children through a mindfulness-based kindness curriculum

Flook, Lisa; Goldberg, Simon B.; Pinger, Laura; Davidson, Richard J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
473.66324%
Self-regulatory abilities are robust predictors of important outcomes across the lifespan, yet they are rarely taught explicitly in school. Using a randomized controlled design, the present study investigated the effects of a 12-week mindfulness-based Kindness Curriculum (KC) delivered in a public school setting on executive function, self-regulation, and prosocial behavior in a sample of 68 preschool children. The KC intervention group showed greater improvements in social competence and earned higher report card grades in domains of learning, health, and social-emotional development, whereas the control group exhibited more selfish behavior over time. Interpretation of effect sizes overall indicate small to medium effects favoring the KC group on measures of cognitive flexibility and delay of gratification . Baseline functioning was found to moderate treatment effects with KC children initially lower in social competence and executive functioning demonstrating larger gains in social competence relative to the control group. These findings, observed over a relatively short intervention period, support the promise of this program for promoting self-regulation and prosocial behavior in young children. They also support the need for future investigation of program implementation across diverse settings.

Temporal patterns of communication in social networks

Miritello, Giovanna
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
395.37312%
This thesis has been a joint project between Universidad Carlos III de Madrid and Telefónica Research (Spain). Specifically, the research has been conducted at the GISC (Grupo Interdisciplinar de Sistemas Complejos), group of Universidad Carlos III and at the analytics and data mining and user modelling research teams of Telefónica Research. The main interest of this research has been in understanding and characterizing large networks of human interactions as continuously changing objects, which members appear and disappear over time and which interactions are characterized by temporal correlations and inhomogeneities. This constitutes a very challenging and novel topic. In fact, although many real social networks are temporal or dynamical networks, which elements and properties continuously change over time, traditional approaches to social network analysis are essentially static: ties (and tie weights) are given by the aggregated activity observed in a given time period, nodes and ties are considered persistent over time, temporal inhomogeneities and correlations between interaction events are neglected, etc. Within this frame, therefore, the time dimension of human behavior has typically been projected out. Although much effort has been devoted in the last years to characterize the temporal patterns of human interaction...

Estudo de composição para concreto extrudável para pré fabricados

Quevedo, Valéria Ramos Baltazar
Fonte: Curitiba Publicador: Curitiba
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
381.76703%
A well established and widely used in the industries of ceramics and polymers, the extrusion process has been also explored by the concrete industry. Although the industry of prefabricated structural concrete using superplasticizers, there are still no specific tests to characterize the behavior in the fresh concrete used for extrusion. Although the industry prefabricated concrete structural use superplasticizers, there're not no specific tests to characterize the behavior of the fresh concrete used for extrusion. It was observed that, even in large companies, the evaluation consists of the slump test in truncated cone and the intuitive experience of an employee to handle the concrete with a shovel manual. However the concrete cast in molds is done by extruding machines that have greater strength and consistency in application. Thus extrudability of concrete is based on the testing of "slump test" and the personal evaluation of the operator, being confirmed in a pilot batch in industrial process itself. This work was based on the manufacturing process of extruded tiles freestanding. Aiming to simulate some of the conditions of the production process, there was an adaptation of the test box-L, which was inserted in the reservoir hose vibrator housing. The test consisted in assessing the behavior of the concrete to be inserted into the reservoir from the L-box and immediately after opening the gate...

Comportamento dependente do tempo de rochas sulfáticas de anidrita e gipso; Time-dependent behavior of sulphatic rocks of the anhydrite and gypsum

Giambastiani, Mauricio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/06/2005 Português
Relevância na Pesquisa
383.30277%
A presente tese tem por objetivo contribuir para o conhecimento do comportamento dependente do tempo das rochas de anidrita e gipso. O maior interesse é fornecer argumentos convincentes sobre os mecanismos físicos responsáveis pelas deformações lentas observadas em algumas escavações subterrâneas realizadas em maciços dessas rochas na Europa, aspecto este que hoje está bastante confuso e escassamente estudado. A hipótese central desta pesquisa é que o comportamento dependente do tempo das rochas de anidrita e gipso deve-se parcial e/ou totalmente às propriedades reológicas (fluência) e não exclusivamente a expansão decorrente da transformação anidrita – gipso como a maioria dos autores sustenta. Este problema será analisado a partir de uma perspectiva experimental através de ensaios específicos. Os ensaios de expansão axial livre em rochas de anidrita permitiram concluir que quando submersas em água destilada, experimentam diminuição de volume por dissolução. Já as amostras de anidrita em contato com solução saturada em 'CA'SO IND.4' mostram uma relação não linear entre deformação axial e o tempo indicando uma taxa de expansão que decresce com o tempo. As taxas de expansão axial variam entre 0...

The Influence of Media Type on Attitude Toward Mobile Advertisements Over Time

Sung, Jungyeon; Cho, Kwangsu
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
Publicado em /01/2012 Português
Relevância na Pesquisa
466.13902%
This study explores the relationships between consumers and mobile advertisements on attitude change over time. Two experiments were used to investigate both immediate and delayed effects of different media types on attitudes toward mobile advertisements. Experiment 1 formulated three types of advertisements corresponding to three media types: text, still pictures, and motion pictures. The results indicate that motion pictures on mobile phones significantly influence consumers' initial attitudes toward advertisements. Experiment 2, focusing on delayed effects, was conducted 4 weeks after Experiment 1. Ninety-five of the 117 participants in Experiment 1 were contacted via cellular phone. The results of Experiment 2 showed a decrease in attitude in relation to motion pictures, whereas an increase in attitude in relation to text and still pictures was observed. The findings were interpreted from the perspectives of media characteristics, consumer behavior, and advertising research.

Detecting Time-dependent Structure in Network Data via a New Class of Latent Process Models

Robinson, Lucy F.; Priebe, Carey E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
488.0145%
We introduce a new class of latent process models for dynamic relational network data with the goal of detecting time-dependent structure. Network data are often observed over time, and static network models for such data may fail to capture relevant dynamic features. We present a new technique for identifying the emergence or disappearance of distinct subpopulations of vertices. In this formulation, a network is observed over time, with attributed edges appearing at random times. At unknown time points, subgroups of vertices may exhibit a change in behavior. Such changes may take the form of a change in the overall probability of connection within or between subgroups, or a change in the distribution of edge attributes. A mixture distribution for latent vertex positions is used to detect heterogeneities in connectivity behavior over time and over vertices. The probability of edges with various attributes at a given time is modeled using a latent-space stochastic process associated with each vertex. A random dot product model is used to describe the dependency structure of the graph. As an application we analyze the Enron email corpus.

Incorporating nocturnal activity of wintering Atlantic brant (Branta bernicla hrota) into 24 hour time-activity and daily energy expenditure models

Heise, Jeremiah
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
388.37086%
Williams, Christopher; The Arctic Goose Joint Venture has established numerous priority areas of research for Atlantic brant (Branta bernicla hrota). Several of these priorities focus on the wintering grounds, as the wintering period is often a limiting time for many species, especially migratory waterfowl. Addressing these areas of research often centers on behavioral observations to construct subsequent time-energy models. While waterfowl have qualitatively been shown to be active nocturnally, limited research has addressed incorporating this activity into time-activity and daily energy expenditure models. Thus, popular assumption promotes that observed diurnal behavior is representative of 24 hrs. As a result, my objectives were to 1) directly quantify the behavioral dynamics of wintering Atlantic brant within the 24 hr period inclusive of morning crepuscular, diurnal, evening crepuscular, and nocturnal periods along southern coastal New Jersey, USA, 2) determine if environmental variability (e.g. freezing temperatures, wind, snow cover, ice cover, etc.), or anthropogenic pressure (e.g. hunting disturbance) affect time spent in different behaviors across the 24 hr period, and 3) evaluate the effect of hunting and non-hunting areas on brant behavior both during and outside the Coastal Zone waterfowl hunting seasons. I observed brant during October-February 2009???2010 and 2010???2011...

A memoryless, stochastic mechanism of timing of phases of behavior by a neural network controller

Saaniya Contractor; Nataliya Kozlova; Vladimir Brezina
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Relevância na Pesquisa
382.4489%
For a sensorimotor network to generate adaptive behavior in the environment, the phases of the behavior must be appropriately timed. When the behavior is driven simply by the sensory stimuli from the environment, these can supply the timing. But when the behavior is driven by an internal "goal" that ignores and perhaps even opposes the immediate sensory stimuli, the timing must be generated internally by the network. We have modeled a realistic behavioral scenario that requires such internal timing. When the sea slug Aplysia feeds, it incrementally ingests long strips of seaweed, driven by ingestive stimuli emanating from the seaweed. But if, having ingested a strip, the animal fails to break the strip off the substrate, it must incrementally egest the entire strip again. To do this, it must ignore the inherent ingestiveness of the seaweed and generate the opposite, egestive behavior, driven by an internal egestive goal, for a length of time that is appropriate for the length of the strip to be egested. In previous work, we found that a differential-equation model of the Aplysia feeding network, with dynamics like those experimentally observed, performed this task extremely well. In this model...

Ecotourism and primate habituation: Behavioral variation in two groups of white-faced capuchins (Cebus capucinus) from Costa Rica

Webb,Shasta E.; McCoy,Michael B.
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
Relevância na Pesquisa
386.4917%
The increase of ecotourism operations within Costa Rica during the last 20yrs has brought more and more humans into close, direct contact with several wildlife species. One of these species is the white-faced capuchin (Cebus capucinus), highly gregarious, and with exposure over time, willing to come into close vicinity of humans and their developments. Such contact has its advantages and disadvantages for the ecotourism industry. We observed white-faced monkeys in order to assess the impact of human presence and development on monkey behavior, with a focus on aggressive, affiliative, and foraging behaviors in Curú Wildlife Refuge (CWR), located in Puntarenas, Costa Rica, and to ascertain the degree of over-habituation of capuchin populations at CWR. Though there exists no discrete behavioral parameters that measure over-habituation, it can be defined as an extreme state of habituation in which non-human primates not only lose fear of humans, but also actively include humans in social interactions or treat them as a food resource. We used instantaneous focal animal and group scan sampling during 8wks in March and April 2012. Two groups (approximately 20-30 individuals each) of capuchins were observed; the first near the tourist development at the Southwestern area of CWR...