Interface dynamics in planar neural field models

Neural field models describe the coarse-grained activity of populations of interacting neurons. Because of the laminar structure of real cortical tissue they are often studied in two spatial dimensions, where they are well known to generate rich patterns of spatiotemporal activity. Such patterns have been interpreted in a variety of contexts ranging from the understanding of visual hallucinations to the generation of electroencephalographic signals. Typical patterns include localized solutions in the form of traveling spots, as well as intricate labyrinthine structures. These patterns are naturally defined by the interface between low and high states of neural activity. Here we derive the equations of motion for such interfaces and show, for a Heaviside firing rate, that the normal velocity of an interface is given in terms of a non-local Biot-Savart type interaction over the boundaries of the high activity regions. This exact, but dimensionally reduced, system of equations is solved numerically and shown to be in excellent agreement with the full nonlinear integral equation defining the neural field. We develop a linear stability analysis for the interface dynamics that allows us to understand the mechanisms of pattern formation that arise from instabilities of spots, rings, stripes and fronts. We further show how to analyze neural field models with linear adaptation currents, and determine the conditions for the dynamic instability of spots that can give rise to breathers and traveling waves.

An evaluation of the theoretical potential and practical opportunity for using greywater for domestic purposes in Ghana

Assessments concerning the effects of climate change, water resource availability and water deprivation in West Africa have not frequently considered the positive contribution to be derived from collecting and reusing water for domestic purposes. Where the originating water is taken from a clean water source and has been used the first time for washing or bathing, this water is commonly called “greywater”. Greywater is a prolific resource that is generated wherever people live. Treated greywater can be used for domestic cleaning, for flushing toilets where appropriate, for washing cars, sometimes for watering kitchen gardens, and for clothes washing prior to rinsing. Therefore, a large theoretical potential exists to increase total water resource availability if greywater were to be widely reused. Locally treated greywater reduces the distribution network requirement, lower construction effort and cost and, wherever possible, minimising the associated carbon footprint. Such locally treated greywater offers significant practical opportunities for increasing the total available water resources at a local level. The reuse of treated greywater is one important action that will help to mitigate the reducing availability of clean water supplies in some areas, and the expected mitigation required in future aligns well with WHO/UNICEF (2012) aspirations. The evaluation of potential opportunities for prioritising greywater systems to support water reuse takes into account the availability of water resources, water use indicators and published estimates in order to understand typical patterns of water demand. The approach supports knowledge acquisition regarding local conditions for enabling capacity building for greywater reuse, the understanding of systems that are most likely to encourage greywater reuse, and practices and future actions to stimulate greywater infrastructure planning, design and implementation. Although reuse might be considered to increase the uncertainty of achieving a specified quality of the water supply, robust methods and technologies are available for local treatment. Resource strategies for greywater reuse have the potential to consistently improve water efficiency and availability in water impoverished and water stressed regions of Ghana and West Africa. Untreated greywater is referred to as “greywater”; treated greywater is referred to as “treated greywater” in this paper.

Relação entre gênero e orientação sexual a partir da perspectiva evolucionista

Este estudo trata da relação entre gênero e orientação sexual a partir da perspectiva interacionista da Psicologia Evolucionista e da análise de diferentes elementos da sexualidade humana. Procurou-se discutir a literatura existente sobre os conceitos de gênero e de orientação sexual, com base nos quatro porquês da Etologia. Propõe-se a existência de múltiplas origens para a orientação sexual, sendo uma delas relacionada aos padrões típicos de gênero e à identidade de gênero. Isso levaria à identificação com indivíduos do mesmo sexo ou do sexo oposto e, consequentemente, à atração pelo grupo diferente daquele com o qual se desenvolveu a identificação. Essa perspectiva integra pré-disposições biológicas à análise de influências culturais, compreendendo, como complementares, vertentes teóricas usualmente tidas como contraditórias.

Avaliação comportamental de crianças com Síndrome do Respirador Bucal

A Síndrome do Respirador Bucal (SRB) ocasiona características físicas e comportamentais que interferem na qualidade de vida da criança. O Transtorno do Déficit de Atenção e Hiperatividade (TDAH) pode estar relacionado à respiração bucal no indivíduo, bem como a presença de Distúrbios Respiratórios do Sono (DRS). Por outro lado, estudos indicam que a adenotonsilectomia reduz a ocorrência de comportamentos sugestivos de TDAH em portadores de SRB, bem como produz melhora significativa nos DRS. Pretendeu-se caracterizar a condição sociodemográfica e de risco e analisar padrões comportamentais indicadores de TDAH e os hábitos de sono de crianças com diagnóstico de Síndrome do Respirador Bucal, observados antes e após a realização de cirurgia de adenoidectomia, tonsilectomia ou adenotonsilectomia. Participaram 44 crianças, de ambos os gêneros, entre dois e 12 anos de idade, atendidas pelo Serviço de Otorrinolaringologia de um hospital universitário, assim como seus cuidadores e professores. A coleta de dados foi realizada mediante aplicação de: (1) Roteiros de entrevistas denominados Informações sobre a família e a criança e História desenvolvimental e médica, aplicados com os cuidadores; (2) Lista de Verificação Comportamental para Crianças – versão para pais (CBCL) e dos critérios para diagnóstico de TDAH do DSM-IV; (2) Lista de Verificação Comportamental para Crianças – versão para professores (TRF); (3) Inventário dos hábitos de sono para crianças pré-escolares e Questionário sobre o comportamento do sono, para escolares; (4) Avaliação comportamental pós-cirúrgica, utilizando-se o CBCL e os Inventários do sono, após dois meses da cirurgia; e (5) Entrevista devolutiva. Os respiradores bucais em sua maioria: (a) eram crianças em período escolar; (b) entre sete e nove anos de idade; (c) do gênero feminino; (d) seu principal cuidador tinha o Ensino Médio Completo; (e) renda familiar mensal entre um e dois salários mínimos; (f) constituição familiar original; e, (g) encontravam-se em risco psicossocial moderado. Observou-se que a maioria das crianças deste estudo teve uma gestação dentro de padrões considerados como normais e seu nascimento se deu de forma adequada; no entanto, uma parcela de respiradores bucais desta amostra ficou cianótica durante ou imediatamente após o parto e apresentou problemas respiratórios nos primeiros meses de vida. A respeito do temperamento do bebê no primeiro ano de vida, grande parte teve dificuldade para dormir, em ser mantido ocupado e foi superativo. A maioria dos marcos desenvolvimentais ocorreu em um período considerado dentro dos padrões típicos do desenvolvimento infantil. Os problemas de saúde mais frequentes foram problemas de apetite e problemas de sono. Tanto as crianças pré-escolares quanto as escolares apresentaram melhoras nos comportamentos característicos do TDAH após a cirurgia, de acordo com dados do CBCL (p=0,723). A maioria dos itens do Inventário dos hábitos de sono para crianças pré-escolares teve redução na frequência dos hábitos inadequados e aumento dos adequados. No Questionário sobre o comportamento do sono, uma minoria apresentou problemas de sono na avaliação pós-cirúrgica e a maior parte dos problemas de sono sofreu redução de frequência. As maiores reduções ocorreram em movimenta-se muito enquanto dorme e ronca enquanto dorme (p=0,000). Sugere-se a avaliação multidisciplinar preventiva da respiração bucal e a incorporação de um grupo controle em estudos futuros, composto por indivíduos respiradores nasais.

Avaliação do consumo do álcool entre universitários

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo de comunidades de foraminíferos em manguezal do Rio Itapanhaú, Bertioga-SP, aplicado à reconstrução paleoambiental

Foraminifera scientific studies became, historically, of your apply in relative dating of rocks, stratigraphic correlations and paleoenvironmental reconstruction. In the last decades, they have been applied on the studies of modern ecosystems, with or without antrhopic influence. Both aspects are interest of petroleum industry. Among other approaches, foraminífera are used as good indicators of the fluctuation of relative sea level. This study aimed to survey and taxonomic study of the community structure of foraminifera in surface samples of a core, 60 cm, collected in mangrove located in Itapanhaú river in Bertioga (SP).It also aims to contribute to the discussion about typical patterns of community structure of mangrove margins and provide elements for discussion on the relative sea level behavior in this area in almost modern times. It was been collected 6 samples along the core of 60 cm of length, each one 10 cm depth. They were made in laboratory and in each sample sought to find at least 100 foraminifera per ml. The species identification was made with reference specified material and collection available on IGCE-UNESPetro, Rio Claro. The community structure was studied in terms of richness, diversity and species composition and was made the results comparison from similar areas to interpret the depositional environment. Were found 21 species within them 13 calcareous and 8 binders, being the most abundant and frequent species Ammonia tepida, Ammonia parkinsoniana e Elphidium spp. Essentially there wasn’t change in the community structure within the period covered by the core which reflects an environment of outer margin of mangrove without noticeable change in relative sea level at the respective time of deposition of muddy sediments. The community structure here recognized its similar to estuarine environment well maintained which indicates a low human impact in the area over the time interval. The agreement of the results...

Spindle burst like spike discharge oscillations in organotypic cultures of neonatal rat cortex

Early network oscillations and spindle bursts are typical patterns of spontaneous rhythmic activity in cortical networks of neonatal rodents in vivo and in vitro. The latter can also be triggered in vivo by stimulation of afferent inputs. The mechanisms underlying such oscillations undergo profound developmental changes in the first postnatal weeks. Their possible role in cortical development is postulated but not known in detail. We have studied spontaneous and evoked patterns of activity in organotypic cultures of slices from neonatal rat cortex grown on multielectrode arrays (MEAs) for extracellular single- and multi-unit recording. Episodes of spontaneous spike discharge oscillations at 7 - 25 Hz lasting for 0.6 - 3 seconds appeared in about half of these cultures spontaneously and could be triggered by electrical stimulation of few distinct electrodes. These oscillations usually covered only restricted areas of the slices. Besides oscillations, single population bursts that spread in a wavelike manner over the whole slice also appeared spontaneously and were triggered by electrical stimulation. In most but not all cultures, population bursts preceded the oscillations. Both population bursts and spike discharge oscillations required intact glutamatergic synaptic transmission since they were suppressed by the AMPA/kainate glutamate receptor antagonist CNQX. The NMDA antagonist d-APV suppressed the oscillations but not the population bursts, suggesting an involvement of NMDA receptors in the oscillations. These findings show that spindle burst like cortical rhythms are reproduced in organotypic cultures of neonatal cortex. The culture model thus allows investigating the role of such rhythms in cortical circuit formation. Supported by SNF grant No. 3100A0-107641/1.

Electrical neuroimaging in the time domain

A publication entitled “A default mode of brain function” initiated a new way of looking at functional imaging data. In this PET study the authors discussed the often-observed consistent decrease of brain activation in a variety of tasks as compared with the baseline. They suggested that this deactivation is due to a task-induced suspension of a default mode of brain function that is active during rest, i.e. that there exists intrinsic well-organized brain activity during rest in several distinct brain regions. This suggestion led to a large number of imaging studies on the resting state of the brain and to the conclusion that the study of this intrinsic activity is crucial for understanding how the brain works. The fact that the brain is active during rest has been well known from a variety of EEG recordings for a very long time. Different states of the brain in the sleep–wake continuum are characterized by typical patterns of spontaneous oscillations in different frequency ranges and in different brain regions. Best studied are the evolving states during the different sleep stages, but characteristic EEG oscillation patterns have also been well described during awake periods (see Chapter 1 for details). A highly recommended comprehensive review on the brain's default state defined by oscillatory electrical brain activities is provided in the recent book by György Buzsaki, showing how these states can be measured by electrophysiological procedures at the global brain level as well as at the local cellular level.

The Effect Of Misleading Prior Information On The Subjective Visual Vertical

When tilted sideways participants misperceive the visual vertical assessed by means of a luminous line in otherwise complete dark- ness. A recent modeling approach (De Vrijer et al., 2009) claimed that these typical patterns of errors (known as A- and E-effects) could be explained by as- suming that participants behave in a Bayes optimal manner. In this study, we experimentally manipulate participants’ prior information about body-in-space orientation and measure the effect of this manipulation on the subjective visual vertical (SVV). Specifically, we explore the effects of veridical and misleading instructions about body tilt orientations on the SVV. We used a psychophys- ical 2AFC SVV task at roll tilt angles of 0 degrees, 16 degrees and 4 degrees CW and CCW. Participants were tilted to 4 degrees under different instruction conditions: in one condition, participants received veridical instructions as to their tilt angle, whereas in another condition, participants received the mis- leading instruction that their body position was perfectly upright. Our results indicate systematic differences between the instruction conditions at 4 degrees CW and CCW. Participants did not simply use an ego-centric reference frame in the misleading condition; instead, participants’ estimates of the SVV seem to lie between their head’s Z-axis and the estimate of the SVV as measured in the veridical condition. All participants displayed A-effects at roll tilt an- gles of 16 degrees CW and CCW. We discuss our results in the context of the Bayesian model by De Vrijer et al. (2009), and claim that this pattern of re- sults is consistent with a manipulation of precision of a prior distribution over body-in-space orientations. Furthermore, we introduce a Bayesian Generalized Linear Model for estimating parameters of participants’ psychometric function, which allows us to jointly estimate group level and individual level parameters under all experimental conditions simultaneously, rather than relying on the traditional two-step approach to obtaining group level parameter estimates.

A case of EDTA-dependent pseudothrombocytopenia: simple recognition of an underdiagnosed and misleading phenomenon

1. BMC Clin Pathol. 2014 May 1;14:19. doi: 10.1186/1472-6890-14-19. eCollection 2014. A case of EDTA-dependent pseudothrombocytopenia: simple recognition of an underdiagnosed and misleading phenomenon. Nagler M, Keller P, Siegrist D, Alberio L. Author information: Department of Hematology and Central Hematology Laboratory, Inselspital University Hospital and University of Berne, CH-3010 Berne, Switzerland. BACKGROUND: EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a common laboratory phenomenon with a prevalence ranging from 0.1-2% in hospitalized patients to 15-17% in outpatients evaluated for isolated thrombocytopenia. Despite its harmlessness, EDTA-PTCP frequently leads to time-consuming, costly and even invasive diagnostic investigations. EDTA-PTCP is often overlooked because blood smears are not evaluated visually in routine practice and histograms as well as warning flags of hematology analyzers are not interpreted correctly. Nonetheless, EDTA-PTCP may be diagnosed easily even by general practitioners without any experiences in blood film examinations. This is the first report illustrating the typical patterns of a platelet (PLT) and white blood cell (WBC) histograms of hematology analyzers. CASE PRESENTATION: A 37-year-old female patient of Caucasian origin was referred with suspected acute leukemia and the crew of the emergency unit arranged extensive investigations for work-up. However, examination of EDTA blood sample revealed atypical lymphocytes and an isolated thrombocytopenia together with typical patterns of WBC and PLT histograms: a serrated curve of the platelet histogram and a peculiar peak on the left side of the WBC histogram. EDTA-PTCP was confirmed by a normal platelet count when examining citrated blood. CONCLUSION: Awareness of typical PLT and WBC patterns may alert to the presence of EDTA-PTCP in routine laboratory practice helping to avoid unnecessary investigations and over-treatment. PMCID: PMC4012027 PMID: 24808761 [PubMed]

Assessing the Potential of Multiple Imputation in Sequence Analysis

Sequence analysis and optimal matching are useful heuristic tools for the descriptive analysis of heterogeneous individual pathways such as educational careers, job sequences or patterns of family formation. However, to date it remains unclear how to handle the inevitable problems caused by missing values with regard to such analysis. Multiple Imputation (MI) offers a possible solution for this problem but it has not been tested in the context of sequence analysis. Against this background, we contribute to the literature by assessing the potential of MI in the context of sequence analyses using an empirical example. Methodologically, we draw upon the work of Brendan Halpin and extend it to additional types of missing value patterns. Our empirical case is a sequence analysis of panel data with substantial attrition that examines the typical patterns and the persistence of sex segregation in school-to-work transitions in Switzerland. The preliminary results indicate that MI is a valuable methodology for handling missing values due to panel mortality in the context of sequence analysis. MI is especially useful in facilitating a sound interpretation of the resulting sequence types.

Re-written by machine and new technology: Did the Internet kill the Video Star

The traditional way of understanding television content consumption and viewer reactions may be simply summarised: information about the program, viewing at airing time, and interpersonal discussion after the program. In our digital media environment due to crossmedia consumption and platform shifts, the actual trend in audiovisual, and traditionally television content consumption is changing, the viewer’s journey is different across contents and platforms. Content is becoming independent from the platform and the medium is increasingly in the hands of technologically empowered viewers. Our objective is to uncover how traditional content expressly manufactured for television (series, reality shows, sports) can now be consumed via other platforms, and how and to what extent audiovisual content consumption is complemented or replaced by other forms (text, audio). In our exploratory research we identify the typical patterns of interaction and synergies of consumption across classical media content. In this study we used a multimethodology qualitative research design with three research phases including focus groups, online content analysis, and viewers’ narratives. Overall, the Video Star stays alive, but has to deal with immediate reactions and has to change according to his or her audiences’ wishes

Study and analysis of the waves and currents interaction phenomena

Interaction of ocean waves, currents and sea bed roughness is a complicated phenomena in fluid dynamic. This paper will describe the governing equations of motions of this phenomena in viscous and nonviscous conditions as well as study and analysis the experimental results of sets of physical models on waves, currents and artificial roughness, and consists of three parts: First, by establishing some typical patterns of roughness, the effects of sea bed roughness on a uniform current has been studied, as well as the manning coefficient of each type is reviewed to find the critical situation due to different arrangement. Second, the effect of roughness on wave parameters changes, such as wave height, wave length, and wave dispersion equations have been studied, third, superimposing, the waves + current + roughness patterns established in a flume, equipped with waves + currents generator, in this stage different analysis has been done to find the governing dimensionless numbers, and present the numbers to define the contortions and formulations of this phenomena. First step of the model is verified by the so called Chinese method, and the Second step by the Kamphius (1975), and third step by the van Rijn (1990) , and Brevik and Ass ( 1980), and in all cases reasonable agreements have been obtained. Finally new dimensionless parameters presented for this complicated phenomena.