7,253 research outputs found

    Variation in habitat choice and delayed reproduction: Adaptive queuing strategies or individual quality differences?

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    In most species, some individuals delay reproduction or occupy inferior breeding positions. The queue hypothesis tries to explain both patterns by proposing that individuals strategically delay breeding (queue) to acquire better breeding or social positions. In 1995, Ens, Weissing, and Drent addressed evolutionarily stable queuing strategies in situations with habitat heterogeneity. However, their model did not consider the non - mutually exclusive individual quality hypothesis, which suggests that some individuals delay breeding or occupy inferior breeding positions because they are poor competitors. Here we extend their model with individual differences in competitive abilities, which are probably plentiful in nature. We show that including even the smallest competitive asymmetries will result in individuals using queuing strategies completely different from those in models that assume equal competitors. Subsequently, we investigate how well our models can explain settleme! nt patterns in the wild, using a long-term study on oystercatchers. This long-lived shorebird exhibits strong variation in age of first reproduction and territory quality. We show that only models that include competitive asymmetries can explain why oystercatchers' settlement patterns depend on natal origin. We conclude that predictions from queuing models are very sensitive to assumptions about competitive asymmetries, while detecting such differences in the wild is often problematic.

    Haematopoietic stem cell transplantation: Evaluation of a patient and carer psychoeducation programme

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    Haematopoietic stem cell transplantation (HSCT) is a complicated and high-risk procedure used to cure disease or stop the spread of disease in a range of cancers. HSCT carries a high incidence of mortality and is associated with distressing short and long-term side effects. In addition, patients remain at risk of recurrence or mortality years after transplantation. Therefore, patients undergoing HSCT have been found to experience significant emotional and psychosocial distress because of the trauma associated with treatment. The literature suggests that about 50% of HSCT patients will experience clinical levels of distress. Carers and family members play an important role in caring for these ill patients in the short and long-term. Major role changes and financial stressors are experienced in many families, adding to the burden of care. However, very little is known about the rates of psychopathology in carers of HSCT patients. Due to the arduous nature of HSCT, psycho-educational programmes have been developed by major transplant centres and hospitals in order to provide HSCT patients and their families with information on the treatment process, side effects, risks, and long-term outcomes. Research on patient education in oncology has shown that providing patients and carers with information about their illness and treatment reduces anxiety and distress. To date, there have been no empirical evaluations to support the use of education programmes for HSCT patients. While it could be assumed that information would be helpful in reducing anxiety and depression in HSCT as it is in oncology generally, the information provided to these patients is usually more confronting and therefore, may be less reassuring. Thus, it is not known whether providing patients with education about HSCT reduces patient and carer distress or whether it might actually increase adverse outcomes. The aim of the present study was to evaluate the rates and correlates of distress in carers and patients and examine the effect of a psychoeducation programme for patients undergoing HSCT and their carers on knowledge, distress, information satisfaction, social support and caregiver burden. A randomised control trial was conducted to provide empirical data in relation to the latter aim. The following hypotheses were proposed. Firstly, it was hypothesised that patients and carers who received the education programme would have higher levels of knowledge, not evidenced in a group waiting to receive the programme. Secondly, it was hypothesised that the education program would not lead to increased anxiety and depressive symptoms. Thirdly, patients who know more about their condition would be the least distressed. As predicted, this study found high levels of distress, particularly in carers. Higher patient distress was related to having more concern about one’s illness and experiencing more symptoms. Education was effective in increasing patient and carer knowledge. Importantly there were no adverse effects of knowledge and greater patient knowledge following the education program was associated with less distress, although there was no direct effect of education on distress. Future research should aim to identify what aspects of the education program are helpful to patients. Finally, support interventions such as CBT are needed to help patients and carers, in particular, cope with the high levels of distress inherent in the HSCT experience

    R package hiphop: parentage assignment using bi-allelic genetic markers. Statistical software

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    Can be used for paternity and maternity assignment and outperforms conventional methods where closely related individuals occur in the pool of possible parents. The method compares the genotypes of offspring with any combination of potentials parents and scores the number of mismatches of these individuals at bi-allelic genetic markers (e.g. Single Nucleotide Polymorphisms). It elaborates on a prior exclusion method based on the Homozygous Opposite Test (HOT; Huisman 2017 ) by introducing the additional exclusion criterion HIPHOP (Homozygous Identical Parents, Heterozygous Offspring are Precluded; Cockburn et al., in revision). Potential parents are excluded if they have more mismatches than can be expected due to genotyping error and mutation, and thereby one can identify the true genetic parents and detect situations where one (or both) of the true parents is not sampled. Package 'hiphop' can deal with (a) the case where there is contextual information about parentage of the mother (i.e. a female has been seen to be involved in reproductive tasks such as nest building), but paternity is unknown (e.g. due to promiscuity), (b) where both parents need to be assigned, because there is no contextual information on which female laid eggs and which male fertilized them (e.g. polygynandrous mating system where multiple females and males deposit young in a common nest, or organisms with external fertilisation that breed in aggregations)

    Arbeid op hightechbedrijf en lagekostenbedrijf

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    De laatste twee jaar realiseerden de bedrijven de werkzaamheden in een gemiddelde bedrijfstijd van 50 uur per week

    Лекарственный анафилактический и псевдоаллергический шок: патогенез, клиника, дифференциальная диагностика, подходы к терапии

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    Представлены особенности патогенеза анафилактического и псевдоаллергического шока, обусловленного лекарственными средствами, сходства и различия в клиническом их течении, субъективные и объективные признаки дифференциальной диагностики, подходы к терапии.The peculiarities of the pathogenesis of anaphylactic and pseudoallergic shock caused by medications, similarity and differences of the clinical course, subjective and objective signs of differential diagnosis, approaches to therapy are presented

    Verification of distributed dataspace architectures

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    Human Bocavirus and KI/WU Polyomaviruses in Pediatric Intensive Care Patients

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    We evaluated the prevalence of human bocavirus and KI and WU polyomaviruses in pediatric intensive care patients with and without lower respiratory tract infection (LRTI). The prevalence of these viruses was 5.1%, 0%, and 2.6%, respectively, in children with LRTI and 4.8%, 4.8%, and 2.4%, respectively, in those without LRTI

    Producing sons reduces lifetime reproductive success of subsequent offspring in pre-industrial Finns

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    Life-history theory states that reproductive events confer costs upon mothers. Many studies have shown that reproduction causes a decline in maternal condition, survival or success in subsequent reproductive events. However, little attention has been given to the prospect of reproductive costs being passed onto subsequent offspring, despite the fact that parental fitness is a function of the reproductive success of progeny. Here we use pedigree data from a pre-industrial human population to compare offspring life-history traits and lifetime reproductive success (LRS) according to the cost incurred by each individual's mother in the previous reproductive event. Because producing a son versus a daughter has been associated with greater maternal reproductive cost, we hypothesize that individuals born to mothers who previously produced sons will display compromised survival and/or LRS, when compared with those produced following daughters. Controlling for confounding factors such as socio-economic status and ecological conditions, we show that those offspring born after elder brothers have similar survival but lower LRS compared with those born after elder sisters. Our results demonstrate a maternal cost of reproduction manifested in reduced LRS of subsequent offspring. To our knowledge, this is the first time such a long-term intergenerational cost has been shown in a mammal species
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