420 research outputs found

    Flogging tired horses: who wants whipping and who would walk away if whipping horses were withheld?

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    Recent studies have cast doubt on the effectiveness of whipping horses during races and this has led to questions concerning its continuing justification. Furthermore, it has been argued that whipping tired horses in racing is the most televised form of violence to animals. The present study used de-identified data from a recent independent Australian poll (n = 1,533) to characterise the 26% of respondents (113 females and 271 males) who support the whipping of racehorses and the 10% of racing enthusiasts in the sample (44 females and 63 males) who would stop watching races and betting on them if whipping were banned. Logistic regression models examining associations between age, gender, and income level of respondents demonstrated that those who support racehorse whipping are significantly more likely to be male. Among racing enthusiasts who would stop watching races and betting on them if whipping were banned, those in the lowest income bracket were over-represented. The more frequently respondents attended races or gambled on them, the more likely they were to agree that horses should be hit with a whip during the normal course of a race. These findings align with previous studies of violence among men and women but may also be attributed to male support of traditional gambling practices. Globally, racing organisations may consider the findings of the present study helpful in their deliberations on the merits of continuing the practice of whipping tired horses in the name of sport. The study might also provide important data for stakeholders who demand that it continues

    Reusable Components of Semantic Specifications

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    Semantic specifications of programming languages typically have poor modularity. This hinders reuse of parts of the semantics of one language when specifying a different language – even when the two languages have many constructs in common – and evolution of a language may require major reformulation of its semantics. Such drawbacks have discouraged language developers from using formal semantics to document their designs. In the PLanCompS project, we have developed a component-based approach to semantics. Here, we explain its modularity aspects, and present an illustrative case study: a component-based semantics for Caml Light. We have tested the correctness of the semantics by running programs on an interpreter generated from the semantics, comparing the output with that produced on the standard implementation of the language. Our approach provides good modularity, facilitates reuse, and should support co-evolution of languages and their formal semantics. It could be particularly useful in connection with domain-specific languages and language-driven software development

    “That little doorway where I could suddenly start shouting out”: barriers and enablers to the disclosure of distressing voices

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    Hearing distressing voices is a key feature of psychosis. The time between voice onset and disclosure may be crucial as voices can grow in complexity. This study investigated barriers and enablers to early voice disclosure. Interviews with 20 voice hearers underwent Thematic Analysis. Beliefs about the effect of disclosure on self and others acted as a barrier and enabler to voices being discussed. Voice hearing awareness should be increased amongst young people, the public and care services. To support earlier disclosure measures need to increase skill amongst those likely to be disclosed to

    Synchronisation of egg hatching of brown hairstreak (Thecla betulae) and budburst of blackthorn (Prunus spinosa) in a warmer future

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    Synchronisation of the phenology of insect herbivores and their larval food plant is essential for the herbivores’ fitness. The monophagous brown hairstreak (Thecla betulae) lays its eggs during summer, hibernates as an egg, and hatches in April or May in the Netherlands. Its main larval food plant blackthorn (Prunus spinosa) flowers in early spring, just before the leaves appear. As soon as the Blackthorn opens its buds, and this varies with spring temperatures, food becomes available for the brown hairstreak. However, the suitability of the leaves as food for the young caterpillars is expected to decrease rapidly. Therefore, the timing of egg hatch is an important factor for larval growth. This study evaluates food availability for brown hairstreak at different temperatures. Egg hatch and budburst were monitored from 2004 to 2008 at different sites in the Netherlands. Results showed ample food availability at all monitored temperatures and sites but the degree of synchrony varied strongly with spring temperatures. To further study the effect of temperature on synchronisation, an experiment using normal temperatures of a reference year (T) and temperatures of T + 5°C was carried out in climate chambers. At T + 5°C, both budburst and egg hatch took place about 20 days earlier and thus, on average, elevated temperature did not affect synchrony. However, the total period of budburst was 11 days longer, whereas the period of egg hatching was 3 days shorter. The implications for larval growth by the brown hairstreak under a warmer climate are considered.

    Interplay between pleiotropy and secondary selection determines rise and fall of mutators in stress response

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    Dramatic rise of mutators has been found to accompany adaptation of bacteria in response to many kinds of stress. Two views on the evolutionary origin of this phenomenon emerged: the pleiotropic hypothesis positing that it is a byproduct of environmental stress or other specific stress response mechanisms and the second order selection which states that mutators hitchhike to fixation with unrelated beneficial alleles. Conventional population genetics models could not fully resolve this controversy because they are based on certain assumptions about fitness landscape. Here we address this problem using a microscopic multiscale model, which couples physically realistic molecular descriptions of proteins and their interactions with population genetics of carrier organisms without assuming any a priori fitness landscape. We found that both pleiotropy and second order selection play a crucial role at different stages of adaptation: the supply of mutators is provided through destabilization of error correction complexes or fluctuations of production levels of prototypic mismatch repair proteins (pleiotropic effects), while rise and fixation of mutators occur when there is a sufficient supply of beneficial mutations in replication-controlling genes. This general mechanism assures a robust and reliable adaptation of organisms to unforeseen challenges. This study highlights physical principles underlying physical biological mechanisms of stress response and adaptation

    Bridging Time Scales in Cellular Decision Making with a Stochastic Bistable Switch

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    Cellular transformations which involve a significant phenotypical change of the cell's state use bistable biochemical switches as underlying decision systems. In this work, we aim at linking cellular decisions taking place on a time scale of years to decades with the biochemical dynamics in signal transduction and gene regulation, occuring on a time scale of minutes to hours. We show that a stochastic bistable switch forms a viable biochemical mechanism to implement decision processes on long time scales. As a case study, the mechanism is applied to model the initiation of follicle growth in mammalian ovaries, where the physiological time scale of follicle pool depletion is on the order of the organism's lifespan. We construct a simple mathematical model for this process based on experimental evidence for the involved genetic mechanisms. Despite the underlying stochasticity, the proposed mechanism turns out to yield reliable behavior in large populations of cells subject to the considered decision process. Our model explains how the physiological time constant may emerge from the intrinsic stochasticity of the underlying gene regulatory network. Apart from ovarian follicles, the proposed mechanism may also be of relevance for other physiological systems where cells take binary decisions over a long time scale.Comment: 14 pages, 4 figure

    A family history of breast cancer will not predict female early onset breast cancer in a population-based setting

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    ABSTRACT: BACKGROUND: An increased risk of breast cancer for relatives of breast cancer patients has been demonstrated in many studies, and having a relative diagnosed with breast cancer at an early age is an indication for breast cancer screening. This indication has been derived from estimates based on data from cancer-prone families or from BRCA1/2 mutation families, and might be biased because BRCA1/2 mutations explain only a small proportion of the familial clustering of breast cancer. The aim of the current study was to determine the predictive value of a family history of cancer with regard to early onset of female breast cancer in a population based setting. METHODS: An unselected sample of 1,987 women with and without breast cancer was studied with regard to the age of diagnosis of breast cancer. RESULTS: The risk of early-onset breast cancer was increased when there were: (1) at least 2 cases of female breast cancer in first-degree relatives (yes/no; HR at age 30: 3.09; 95% CI: 128-7.44), (2) at least 2 cases of female breast cancer in first or second-degree relatives under the age of 50 (yes/no; HR at age 30: 3.36; 95% CI: 1.12-10.08), (3) at least 1 case of female breast cancer under the age of 40 in a first- or second-degree relative (yes/no; HR at age 30: 2.06; 95% CI: 0.83-5.12) and (4) any case of bilateral breast cancer (yes/no; HR at age 30: 3.47; 95%: 1.33-9.05). The positive predictive value of having 2 or more of these characteristics was 13% for breast cancer before the age of 70, 11% for breast cancer before the age of 50, and 1% for breast cancer before the age of 30. CONCLUSION: Applying family history related criteria in an unselected population could result in the screening of many women who will not develop breast cancer at an early age

    Does Work Affect Personality? A Study in Horses

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    It has been repeatedly hypothesized that job characteristics are related to changes in personality in humans, but often personality models still omit effects of life experience. Demonstrating reciprocal relationships between personality and work remains a challenge though, as in humans, many other influential factors may interfere. This study investigates this relationship by comparing the emotional reactivity of horses that differed only by their type of work. Horses are remarkable animal models to investigate this question as they share with humans working activities and their potential difficulties, such as “interpersonal” conflicts or “suppressed emotions”. An earlier study showed that different types of work could be associated with different chronic behavioural disorders. Here, we hypothesised that type of work would affect horses' personality. Therefore over one hundred adult horses, differing only by their work characteristics were presented standardised behavioural tests. Subjects lived under the same conditions (same housing, same food), were of the same sex (geldings), and mostly one of two breeds, and had not been genetically selected for their current type of work. This is to our knowledge the first time that a direct relationship between type of work and personality traits has been investigated. Our results show that horses from different types of work differ not as much in their overall emotional levels as in the ways they express emotions (i.e. behavioural profile). Extremes were dressage horses, which presented the highest excitation components, and voltige horses, which were the quietest. The horses' type of work was decided by the stall managers, mostly on their jumping abilities, but unconscious choice based on individual behavioural characteristics cannot be totally excluded. Further research would require manipulating type of work. Our results nevertheless agree with reports on humans and suggest that more attention should be given to work characteristics when evaluating personalities

    Frozen section analysis of sentinel lymph nodes in patients with breast cancer does not impair the probability to detect lymph node metastases

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    Intra-operative frozen section analysis (FS analysis) of sentinel lymph nodes (SLNs) in patients with breast cancer can prevent a second operation for axillary lymph node dissection. In contrast, loss of tissue during FS analysis may impair the probability to detect lymph node metastases. To determine the effect of tissue loss on the probability of detection of metastases, dimensions and tissue loss resulting from intra-operative frozen section analysis were measured for 21 SLNs. In a mathematical model, the influence of tissue loss on the probability to detect metastases was calculated in relation to SLN size for various pathology protocols: an American, a widely used European, the extensive ‘Milan’ and the Dutch protocol. For median-sized SLN 11 × 8 × 5 mm (length × width × height), FS analysis led to a median loss of 680 μm (13.6%) of the height of the SLN. Irrespective of SLN size or used pathology protocol, the probability of detecting 2 mm metastases remained unchanged or even increased (0–12.8%). Moreover, the probability to detect 0.2 mm metastases increased for the majority of tested combinations of SLN size, tissue loss and used protocol. Only when combining maximum tissue loss and smallest SLN size in the Dutch protocol, or when applying the extensive Milan protocol on a median-sized SLN, the probability to detect 0.2 mm metastases decreased by 2.7% and 14.3%, respectively. Contrary to ‘common knowledge’, doing FS analysis of SLNs does not impair the probability to detect lymph node metastases

    Predicting the Evolution of Sex on Complex Fitness Landscapes

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    Most population genetic theories on the evolution of sex or recombination are based on fairly restrictive assumptions about the nature of the underlying fitness landscapes. Here we use computer simulations to study the evolution of sex on fitness landscapes with different degrees of complexity and epistasis. We evaluate predictors of the evolution of sex, which are derived from the conditions established in the population genetic literature for the evolution of sex on simpler fitness landscapes. These predictors are based on quantities such as the variance of Hamming distance, mean fitness, additive genetic variance, and epistasis. We show that for complex fitness landscapes all the predictors generally perform poorly. Interestingly, while the simplest predictor, ΔVarHD, also suffers from a lack of accuracy, it turns out to be the most robust across different types of fitness landscapes. ΔVarHD is based on the change in Hamming distance variance induced by recombination and thus does not require individual fitness measurements. The presence of loci that are not under selection can, however, severely diminish predictor accuracy. Our study thus highlights the difficulty of establishing reliable criteria for the evolution of sex on complex fitness landscapes and illustrates the challenge for both theoretical and experimental research on the origin and maintenance of sexual reproduction
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