180 resultados para Underlying determinants


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The degree of individual specialization in resource use differs widely among wild populations where individuals range from fully generalized to highly specialized. This interindividual variation has profound implications in many ecological and evolutionary processes. A recent review proposed four main ecological causes of individual specialization: interspecific and intraspecific competition, ecological opportunity and predation. Using the isotopic signature of subsampled whiskers, we investigated to what degree three of these factors (interspecific and intraspecific competition and ecological opportunity) affect the population niche width and the level of individual foraging specialization in two fur seal species, the Antarctic and subantarctic fur seals (Arctocephalus gazella and Arctocephalus tropicalis), over several years. Population niche width was greater when the two seal species bred in allopatry (low interspecific competition) than in sympatry or when seals bred in high-density stabilized colonies (high intraspecific competition). In agreement with the niche variation hypothesis (NVH), higher population niche width was associated with higher interindividual niche variation. However, in contrast to the NVH, all Antarctic females increased their niche width during the interbreeding period when they had potential access to a wider diversity of foraging grounds and associated prey (high ecological opportunities), suggesting they all dispersed to a similar productive area. The degree of individual specialization varied among populations and within the annual cycle. Highest levels of interindividual variation were found in a context of lower interspecific or higher intraspecific competition. Contrasted results were found concerning the effect of ecological opportunity. Depending on seal species, females exhibited either a greater or lower degree of individual specialization during the interbreeding period, reflecting species-specific biological constraints during that period. These results suggest a significant impact of ecological interactions on the population niche width and degree of individual specialization. Such variation at the individual level may be an important factor in the species plasticity with significant consequences on how it may respond to environmental variability.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 This thesis investigates how capital structure decisions of private and public firms in the UK differ in regards to their ownership structure, information asymmetry (proxied by audit quality) and access to debt capital.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 Participation in both physical activity and sedentary behaviours follow a social gradient, such that those who are more advantaged are more likely to be regularly physically active, less likely to be sedentary, and less likely to experience the adverse health outcomes associated with inactive lifestyles than their less advantaged peers. The aim of this paper is to provide, in a format that will support policymakers and practitioners, an overview of the current evidence base and highlight promising approaches for promoting physical activity and reducing sedentary behaviours equitably at each level of ‘Fair Foundations: The VicHealth framework for health equity’. A rapid review was undertaken in February–April 2014. Electronic databases (Medline, PsychINFO, SportsDISCUS, CINAHL, Scopus, Web of Science, Cochrane Library, Global Health and Embase) were searched using a pre-defined search strategy and grey literature searches of websites of key relevant organizations were undertaken. The majority of included studies focussed on approaches targeting behaviour change at the individual level, with fewer focussing on daily living conditions or broader socioeconomic, political and cultural contexts. While many gaps in the evidence base remain, particularly in relation to reducing sedentary behaviour, promising approaches for promoting physical activity equitably across the three levels of the Fair Foundations framework include: community-wide approaches; support for local and state governments to develop policies and practices; neighbourhood designs (including parks) that are conducive to physical activity; investment in early childhood interventions; school programmes; peer- or group-based programmes; and targeted motivational, cognitive-behavioural, and/or mediated individual-level approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 Social Recruiting technologies such as LinkedIn and Twitter have been fast emerging as one of the modern recruitment methods. However, research on their effective usage is scarce and outpaced by organisational practice. The current study addresses this gap by investigating the drivers of SR technology adoption on one hand, and their pre-hire outcomes on the other.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article is part of a Special Issue SBN 2014. Photoperiod and the hormonal response it triggers are key determinants of reproductive timing in birds. However, other cues and physiological traits may permit flexibility in the timing of breeding and perhaps facilitate adaptation to global change. Opportunistic breeders are excellent models to study the adaptive significance of this flexibility, especially at the individual level. Here, we sought to quantify whether particular male physiological and behavioral traits were linked to reproductive timing and output in wild-derived zebra finches. We repeatedly assessed male stress-induced corticosterone levels (CORT), basal metabolic rate (BMR), and activity before releasing them into outdoor aviaries and quantifying each pair's breeding timing, investment, and output over a seven-month period. Despite unlimited access to food and water, the colony breeding activity occurred in waves, probably due to interpair social stimulations. Pairs adjusted their inter-clutch interval and clutch size to social and temperature cues, respectively, but only after successful breeding attempts, suggesting a facultative response to external cues. When these effects were controlled for statistically or experimentally, breeding intervals were repeatable within individuals across reproductive attempts. In addition, males' first laying date and total offspring production varied with complex interactions between pre-breeding CORT, BMR and activity levels. These results suggest that no one trait is under selection but that, instead, correlational selection acts on hormone levels, metabolism, and behavior. Together our results suggest that studying inter-individual variation in breeding strategy and their multiple physiological and behavioral underpinnings may greatly improve our understanding of the mechanisms underlying the evolution of breeding decisions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: In developed countries, individuals experiencing socioeconomic disadvantage - whether a low education level, low income, low-status occupation, or living in a socioeconomically disadvantaged neighbourhood - are less likely than those more advantaged to engage in eating and physical activity behaviours conducive to optimal health. These socioeconomic inequities in nutrition and physical activity (and some sedentary) behaviours are graded, persistent, and evident across multiple populations and studies. They are concerning in that they mirror socioeconomic inequities in obesity and in health outcomes. Yet there remains a dearth of evidence of the most effective means of addressing these inequities. People experiencing disadvantage face multiple challenges to healthy behaviours that can appear insurmountable. With increasing recognition of the role of underlying structural and societal factors as determinants of nutrition and physical activity behaviours and inequities in these behaviours, and the limited success of behaviour change approaches in addressing these inequities, we might wonder whether there remains a role for behavioural scientists to tackle these challenges. DISCUSSION: This debate piece argues that behavioural scientists can play an important role in addressing socioeconomic inequities in nutrition, physical activity and sedentary behaviours, and that this will involve challenging myths and taking on new perspectives. There are successful models for doing so from which we can learn. Addressing socioeconomic inequities in eating, physical activity and sedentary behaviours is challenging. However, successful examples demonstrate that overcoming such challenges is possible, and provide guidance for doing so. Given the disproportionate burden of ill health carried by people experiencing socioeconomic disadvantage, all our nutrition and physical activity interventions, programs and policies should be designed to reach and positively impact these individuals at greatest need.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we investigate the trust-based mechanisms underlying the relationship between ethical leadership and followers' organisational citizenship behaviours (OCBs). Based on three-wave survey data obtained from 184 employees and their supervisors, we find that ethical leadership leads to higher levels of both affective and cognitive trust. In addition, we find support for a three-path mediational model, where cognitive trust and affective trust, in turn, mediate the relationship between ethical leadership and follower OCBs. That is to say, we found that ethical leadership leads to the development of cognitive trust, which subsequently influences the development of affective trust. Affective trust, in turn, induces followers to exhibit OCBs as a means of reciprocating the leader's favourable behaviour. Our findings suggest that both affective and cognitive trust plays an important role in the social exchange processes that underlie the relationship between ethical leadership and the discretionary behaviour of followers. © 2013 Springer Science+Business Media Dordrecht.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract
Purpose– The purpose of this paper is to examine the factors which determine the adoption of best HR practices in Chinese small- and medium-sized enterprises (SMEs).
Design/methodology/approach – Regression analysis was utilized to analyse survey data obtained from 345 enterprises operating across China in a wide range of industrial sectors.
Findings – Enterprises with greater resources in terms of their size, their relationships with external organizations, their cooperation with foreign partners and the human capital of their CEO were found to be more likely to adopt best HR practices. Contrary to the findings of the existing literature no relationship was found of a relationship between family ownership and the use of best HR practices.
Research limitations/implications – The cross-sectional design is an obvious limitation of the study. Other limitations relate to the generalizability of the study findings outside the context in which the research was undertaken, and the use of convenience sampling.
Practical implications – Enterprises should consider building strategic relationships with external organizations and developing cooperation with foreign partners as a way of leveraging human resource expertise at a limited cost.
Originality/value – This is the first study to examine how differences in the resource endowments of Chinese SMEs influence their adoption of best HR practices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Mastitis is an acute, debilitating condition that occurs in approximately 20 % of breastfeeding women who experience a red, painful breast with fever. This paper describes the factors correlated with mastitis and investigates the presence of Staphylococcus aureus in women who participated in the CASTLE (Candida and Staphylococcus Transmission: Longitudinal Evaluation) study. The CASTLE study was a prospective cohort study which recruited nulliparous women in late pregnancy in two maternity hospitals in Melbourne, Australia in 2009-2011.

METHODS: Women completed questionnaires at recruitment and six time-points in the first eight weeks postpartum. Postpartum questionnaires asked about incidences of mastitis, nipple damage, milk supply, expressing practices and breastfeeding problems. Nasal and nipple swabs were collected from mothers and babies, as well as breast milk samples. All samples were cultured for S. aureus. "Time at risk" of mastitis was defined as days between birth and first occurrence of mastitis (for women who developed mastitis) and days between birth and the last study time-point (for women who did not develop mastitis). Risk factors for incidence of mastitis occurring during the time at risk (Incident Rate Ratios [IRR]) were investigated using a discrete version of the multivariable proportional hazards regression model.

RESULTS: Twenty percent (70/346) of participants developed mastitis. Women had an increased risk of developing mastitis if they reported nipple damage (IRR 2.17, 95 % CI 1.21, 3.91), over-supply of breast milk (IRR 2.60, 95 % CI 1.58, 4.29), nipple shield use (IRR 2.93, 95 % CI 1.72, 5.01) or expressing several times a day (IRR 1.64, 95 % CI 1.01, 2.68). The presence of S. aureus on the nipple (IRR 1.72, 95 % CI 1.04, 2.85) or in milk (IRR 1.78, 95 % CI 1.08, 2.92) also increased the risk of developing mastitis.

CONCLUSIONS: Nipple damage, over-supply of breast milk, use of nipple shields and the presence of S. aureus on the nipple or in breast milk increased the mastitis risk in our prospective cohort study sample. Reducing nipple damage may help reduce maternal breast infections.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The recent unprecedented scale of Chinese migration has had far-reaching consequences. Within China, many villages have been drained of their young and most able workers, cities have been swamped by the ‘floating population’, and many rural migrants have been unable to integrate into urban society. Internationally, the Chinese have become increasingly more mobile. This Handbook provides a unique collection of new and original research on internal and international Chinese migration and its effects on the sense of belonging of migrants.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The epidemiology of invasive fungal disease (IFD) due to filamentous fungi other than Aspergillus may be changing. We analysed clinical, microbiological and outcome data in Australian patients to determine the predisposing factors and identify determinants of mortality. Proven and probable non-Aspergillus mould infections (defined according to modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria) from 2004 to 2012 were evaluated in a multicentre study. Variables associated with infection and mortality were determined. Of 162 episodes of non-Aspergillus IFD, 145 (89.5%) were proven infections and 17 (10.5%) were probable infections. The pathogens included 29 fungal species/species complexes; mucormycetes (45.7%) and Scedosporium species (33.3%) were most common. The commonest comorbidities were haematological malignancies (HMs) (46.3%) diabetes mellitus (23.5%), and chronic pulmonary disease (16%); antecedent trauma was present in 21% of cases. Twenty-five (15.4%) patients had no immunocompromised status or comorbidity, and were more likely to have acquired infection following major trauma (p <0.01); 61 (37.7%) of cases affected patients without HMs or transplantation. Antifungal therapy was administered to 93.2% of patients (median 68 days, interquartile range 19-275), and adjunctive surgery was performed in 58.6%. The all-cause 90-day mortality was 44.4%; HMs and intensive-care admission were the strongest predictors of death (both p <0.001). Survival varied by fungal group, with the risk of death being significantly lower in patients with dematiaceous mould infections than in patients with other non-Aspergillus mould infections. Non-Aspergillus IFD affected diverse patient groups, including non-immunocompromised hosts and those outside traditional risk groups; therefore, definitions of IFD in these patients are required. Given the high mortality, increased recognition of infections and accurate identification of the causative agent are required.