137 research outputs found

    Deficits in episodic future thinking following acute alcohol consumption

    Get PDF
    Rationale Acute alcohol consumption adversely affects many cognitive abilities, including episodic memory and executive functioning. However, no study to date has tested whether these acute effects of alcohol also extend to episodic future thinking (EFT). This is a surprising omission given that EFT refers to the ability to imagine oneself experiencing the future, a highly adaptive ability that has been implicated in many important functional behaviours. EFT is also thought to impose demands on episodic memory and executive control. Objectives The current study was designed to provide the first test of whether a moderate dose of alcohol influences EFT and whether any observed EFT difficulties are secondary to broader problems in episodic memory and executive functioning. Sex differences in EFT following acute alcohol consumption were also examined. Methods One hundred and twenty-four healthy adult social drinkers were recruited and randomly assigned to either the alcohol (n = 61) or placebo (n = 63) condition. Participants were administered a dose of 0.6 g/kg alcohol or a matched placebo drink. Results Relative to the placebo condition, EFT was impaired by acute alcohol consumption. This impairment was underpinned by broader difficulties with episodic memory, but not executive functioning. There were no sex differences in EFT performance following acute alcohol use. Conclusion These data provide novel insights into the effects of acute alcohol consumption on EFT and the broader cognitive mechanisms that contribute to these difficulties. The results are discussed in relation to their implications for understanding many of the maladaptive behaviours commonly associated with acute alcohol use

    Prospective memory impairment in chronic heart failure

    Get PDF
    Although cognitive deficits are common in patients with chronic heart failure (CHF), no study to date has investigated whether these deficits extend to the capacity to execute delayed intentions (prospective memory, PM). This is a surprising omission given the critical role PM plays in correctly implementing many important CHF self-care behaviors. The present study aimed to provide the first empirical assessment of PM function in people with CHF. The key dependent measure was a laboratory measure of PM that closely simulates PM tasks in daily life - Virtual Week. A group comparison design was used, with 30 CHF patients compared to 30 demographically matched controls. Background measures assessing executive functions, working memory, and verbal memory were also administered. The CHF group exhibited significant PM impairment, with difficulties generalizing across different types of PM tasks (event, time, regular, irregular). The CHF group also had moderate deficits on several of the background cognitive measures. Given the level of impairment remained consistent even on tasks that imposed minimal demands on memory for task content, CHF-related difficulties most likely reflects problems with the prospective component. However, exploratory analyses suggest that difficulties with retrospective memory and global cognition (but not executive control), also contribute to the PM difficulties seen in this group. The implications of these data are discussed, and in particular, it is argued that problems with PM may help explain why patient engagement in CHF self-care behaviors is often poor. (JINS, 2015, 21, 1-10)</p

    Perception of biological motion and emotion in mild cognitive impairment and dementia

    Get PDF
    Participants diagnosed with mild cognitive impairment (MCI), dementia and controls completed measures that required decoding emotions from point-light displays of bodily motion, and static images of facial affect. Both of these measures tap social cognitive processes that are considered critical for social competency. Consistent with prior literature, both clinical groups were impaired on the static measure of facial affect recognition. The dementia (but not the MCI) group additionally showed difficulties interpreting biological motion cues. However, this did not reflect a specific deficit in decoding emotions, but instead a more generalized difficulty in processing visual motion (both to action and to emotion). These results align with earlier studies showing that visual motion processing is disrupted in dementia, but additionally show for the first time that this extends to the recognition of socially relevant biological motion. The absence of any MCI related impairment on the point-light biological emotion measure (coupled with deficits on the measure of facial affect recognition) also point to a potential disconnect between the processes implicated in the perception of emotion cues from static versus dynamic stimuli. For clinical (but not control) participants, performance on all recognition measures was inversely correlated with level of semantic memory impairment

    Aspectos microbiológicos e epidemiológicos dos surtos causados por Salmonella sp em criações não industriais de Gallus gallus domesticus no Estado do Paraná

    Get PDF
    Orientador: Yasuyoshi HayashiDissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias AgrariasCom o objetivo de verificar a participação de Salmonella sp como causa de mortalidade entre as aves domésticas das criações caseiras no Estado do Paraná, foram analisadas, no período de 1987 a 1991, 671 amostras de aves, obtendo-se 7,0% de isolamento positivo, totalizando 47 cepas do microrganismo. Foram encontrados três sorovares causando doença, entre os quais, S.gallinarum (82,9%) responsável pela maioria dos surtos, seguido pela S.pullorum (12,7%) e S.enteritidis (4,2%). Vale ressaltar que o sorovar S.pullorum afetou somente as aves adultas. As 47 cepas de Salmonella pertenciam ao sorogrupo D1 , apresentando semelhante sensibilidade e resistência aos antibióticos e quimioterápicos quando testados "in vitro". Comprovou-se estatisticamente correlação entre o isolamento dos três sorovares citados com a morbidade e mortalidade ocorridas. Quanto ao sorovar S.gallinarum, as taxas médias de morbidade e mortalidade observadas nas aves consideradas jovens adultas (duas a oito semanas de idade) e adultas (mais de oito semanas de idade), situaram-se em 17 ,8%, 34,3% e 17,3%, 33,6%, respectivamente. No que se refere à S.pullorum as mesmas faixas etárias em relação a morbidade foram de 3,2% e 26,9% e mortalidade de 3,2% e 24,8%. S.enteritidis causou índices de morbidade de 23,8% e mortalidade de 22,6% somente na faixa etária das aves consideradas adultas. As aves jovens (1 a 14 dias de idade) não foram afetadas pela doença. Os percentuais de letalidade em relação à S.gallinarum, S.pullorum e S.enteritidis, foram de 97 ,9%, 93,3% e 95,0%, respectivamente. Observou-se ainda que a salmonelose ocorreu em todos os meses do ano. No entanto, quando distribuídos nas estações do ano, a primavera (31,9%) concentrou maior número de surtos, seguido do outono (25,5%), verão (23,4%) e inverno (19,1%)In order to check the role of the Salmonella as the cause of mortality of non commercial flocks of chicken in the State of Parana - Brazil, between 1987 and 1991, 671 samples were analyzed. The percentage of positive cases was 7,0%, comprising 47 different strains of the microorganism. Three serovars of Salmonella affected the birds. S.gallinarum was present in 82,9% of the outbreaks, S.pullorum in 12,7%, and S.enteritidis in only 4,2% of them. It is important to notice that S.pullorum affected only adult animals. When tested "in vitro" all the 47 strains of Salmonella belonged to the D1 serogroup, and showed similar resistance and sensitivity to antibacterial drugs. There is statistically significant correlation between the isolated serovars and the occurrence of morbidity and mortality .The mean rates of morbidity and mortality caused by the S.gallinarum serovar were respectively 17,8% and 34,3%, for young adults (two to eight weeks) and 17,3% and 33,6%, for adults (more than eight weeks). For the same are groups, the mean rates related to morbidity and mortality caused by S.pullorum was 3,2% and 26,9%, and 3,2% and 24,8%, respectively .The S.enteritidis affected only adult birds, causing 23,8% of morbidity and 22,6% of mortality. The group of young birds (one to 14 days) did not show morbidity or mortality .The lethality caused by S.gallinarum, S.pullorum and S.enteritidis was 97,9%, 93,3% and 95,0%, respectively. The salmonellosis was observed in all months of the year, with the greater number of outbreaks in the spring (31,9%). The percentages for the other seasons were 25,5%,23,4% and 19,1%, for the fallt, summer and winter, respectivel

    Systematic techniques for assisting recruitment to trials (START): study protocol for embedded, randomized controlled trials

    Get PDF
    BACKGROUND: Randomized controlled trials play a central role in evidence-based practice, but recruitment of participants, and retention of them once in the trial, is challenging. Moreover, there is a dearth of evidence that research teams can use to inform the development of their recruitment and retention strategies. As with other healthcare initiatives, the fairest test of the effectiveness of a recruitment strategy is a trial comparing alternatives, which for recruitment would mean embedding a recruitment trial within an ongoing host trial. Systematic reviews indicate that such studies are rare. Embedded trials are largely delivered in an ad hoc way, with interventions almost always developed in isolation and tested in the context of a single host trial, limiting their ability to contribute to a body of evidence with regard to a single recruitment intervention and to researchers working in different contexts. METHODS/DESIGN: The Systematic Techniques for Assisting Recruitment to Trials (START) program is funded by the United Kingdom Medical Research Council (MRC) Methodology Research Programme to support the routine adoption of embedded trials to test standardized recruitment interventions across ongoing host trials. To achieve this aim, the program involves three interrelated work packages: (1) methodology - to develop guidelines for the design, analysis and reporting of embedded recruitment studies; (2) interventions - to develop effective and useful recruitment interventions; and (3) implementation - to recruit host trials and test interventions through embedded studies. DISCUSSION: Successful completion of the START program will provide a model for a platform for the wider trials community to use to evaluate recruitment interventions or, potentially, other types of intervention linked to trial conduct. It will also increase the evidence base for two types of recruitment intervention. TRIAL REGISTRATION: The START protocol covers the methodology for embedded trials. Each embedded trial is registered separately or as a substudy of the host trial

    Light emission from a scanning tunneling microscope: Fully retarded calculation

    Full text link
    The light emission rate from a scanning tunneling microscope (STM) scanning a noble metal surface is calculated taking retardation effects into account. As in our previous, non-retarded theory [Johansson, Monreal, and Apell, Phys. Rev. B 42, 9210 (1990)], the STM tip is modeled by a sphere, and the dielectric properties of tip and sample are described by experimentally measured dielectric functions. The calculations are based on exact diffraction theory through the vector equivalent of the Kirchoff integral. The present results are qualitatively similar to those of the non-retarded calculations. The light emission spectra have pronounced resonance peaks due to the formation of a tip-induced plasmon mode localized to the cavity between the tip and the sample. At a quantitative level, the effects of retardation are rather small as long as the sample material is Au or Cu, and the tip consists of W or Ir. However, for Ag samples, in which the resistive losses are smaller, the inclusion of retardation effects in the calculation leads to larger changes: the resonance energy decreases by 0.2-0.3 eV, and the resonance broadens. These changes improve the agreement with experiment. For a Ag sample and an Ir tip, the quantum efficiency is \approx 104^{-4} emitted photons in the visible frequency range per tunneling electron. A study of the energy dissipation into the tip and sample shows that in total about 1 % of the electrons undergo inelastic processes while tunneling.Comment: 16 pages, 10 figures (1 ps, 9 tex, automatically included); To appear in Phys. Rev. B (15 October 1998

    Specialization of amygdala subregions in emotion processing

    Get PDF
    The amygdala is important for human fear processing. However, recent research has failed to reveal specificity, with evidence that the amygdala also responds to other emotions. A more nuanced understanding of the amygdala's role in emotion processing, particularly relating to fear, is needed given the importance of effective emotional functioning for everyday function and mental health. We studied 86 healthy participants (44 females), aged 18–49 (mean 26.12 ± 6.6) years, who underwent multiband functional magnetic resonance imaging. We specifically examined the reactivity of four amygdala subregions (using regions of interest analysis) and related brain connectivity networks (using generalized psycho-physiological interaction) to fear, angry, and happy facial stimuli using an emotional face-matching task. All amygdala subregions responded to all stimuli (p-FDR <.05), with this reactivity strongly driven by the superficial and centromedial amygdala (p-FDR <.001). Yet amygdala subregions selectively showed strong functional connectivity with other occipitotemporal and inferior frontal brain regions with particular sensitivity to fear recognition and strongly driven by the basolateral amygdala (p-FDR <.05). These findings suggest that amygdala specialization to fear may not be reflected in its local activity but in its connectivity with other brain regions within a specific face-processing network

    Spatiotemporal Patterns in Nest Box Occupancy by Tree Swallows Across North America

    Get PDF
    Data from the North American Breeding Bird Survey (BBS) suggest that populations of aerial insectivorous birds are declining, particularly in northeastern regions of the continent, and particularly since the mid-1980s. Species that use nest boxes, such as Tree Swallows (Tachycineta bicolor), may provide researchers with large data sets that better reveal finer-scale geographical patterns in population trends. We analyzed trends in occupancy rates for ca. 40,000 Tree Swallow nest-box-years from 16 sites across North America. The earliest site has been studied intensively since 1969 and the latest site since 2004. Nest box occupancy rates declined significantly at five of six (83%) sites east of -78° W longitude, whereas occupancy rates increased significantly at four of ten sites (40%) west of -78° W longitude. Decreasing box occupancy trends from the northeast were broadly consistent with aspects of a previous analysis of BBS data for Tree Swallows, but our finding of instances of increases in other parts of the continent are novel. Several questions remain, particularly with respect to causes of these broad-scale geographic changes in population densities of Tree Swallows. The broad geographic patterns are consistent with a hypothesis of widespread changes in climate on wintering, migratory, or breeding areas that in turn may differentially affect populations of aerial insects, but other explanations are possible. It is also unclear whether these changes in occupancy rates reflect an increase or decrease in overall populations of Tree Swallows. Regardless, important conservation steps will be to unravel causes of changing populations of aerial insectivores in North America

    The interpretations and uses of fitness landscapes in the social sciences

    Get PDF
    __Abstract__ This working paper precedes our full article entitled “The evolution of Wright’s (1932) adaptive field to contemporary interpretations and uses of fitness landscapes in the social sciences” as published in the journal Biology & Philosophy (http://link.springer.com/article/10.1007/s10539-014-9450-2). The working paper features an extended literature overview of the ways in which fitness landscapes have been interpreted and used in the social sciences, for which there was not enough space in the full article. The article features an in-depth philosophical discussion about the added value of the various ways in which fitness landscapes are used in the social sciences. This discussion is absent in the current working paper. Th

    Bayesian spatial NBDA for diffusion data with home-base coordinates

    Get PDF
    Network-based diffusion analysis (NBDA) is a statistical method that allows the researcher to identify and quantify a social influence on the spread of behaviour through a population. Hitherto, NBDA analyses have not directly modelled spatial population structure. Here we present a spatial extension of NBDA, applicable to diffusion data where the spatial locations of individuals in the population, or of their home bases or nest sites, are available. The method is based on the estimation of inter-individual associations (for association matrix construction) from the mean inter-point distances as represented on a spatial point pattern of individuals, nests or home bases. We illustrate the method using a simulated dataset, and show how environmental covariates (such as that obtained from a satellite image, or from direct observations in the study area) can also be included in the analysis. The analysis is conducted in a Bayesian framework, which has the advantage that prior knowledge of the rate at which the individuals acquire a given task can be incorporated into the analysis. This method is especially valuable for studies for which detailed spatially structured data, but no other association data, is available. Technological advances are making the collection of such data in the wild more feasible: for example, bio-logging facilitates the collection of a wide range of variables from animal populations in the wild. We provide an R package, spatialnbda, which is hosted on the Comprehensive R Archive Network (CRAN). This package facilitates the construction of association matrices with the spatial x and y coordinates as the input arguments, and spatial NBDA analyses
    corecore