31,221 research outputs found
Multiple morbidities in companion dogs: a novel model for investigating age-related disease
The proportion of men and women surviving over 65 years has been steadily increasing over the last century. In their later years, many of these individuals are afflicted with multiple chronic conditions, placing increasing pressure on healthcare systems. The accumulation of multiple health problems with advanced age is well documented, yet the causes are poorly understood. Animal models have long been employed in attempts to elucidate these complex mechanisms with limited success. Recently, the domestic dog has been proposed as a promising model of human aging for several reasons. Mean lifespan shows twofold variation across dog breeds. In addition, dogs closely share the environments of their owners, and substantial veterinary resources are dedicated to comprehensive diagnosis of conditions in dogs. However, while dogs are therefore useful for studying multimorbidity, little is known about how aging influences the accumulation of multiple concurrent disease conditions across dog breeds. The current study examines how age, body weight, and breed contribute to variation in multimorbidity in over 2,000 companion dogs visiting private veterinary clinics in England. In common with humans, we find that the number of diagnoses increases significantly with age in dogs. However, we find no significant weight or breed effects on morbidity number. This surprising result reveals that while breeds may vary in their average longevity and causes of death, their age-related trajectories of morbidities differ little, suggesting that age of onset of disease may be the source of variation in lifespan across breeds. Future studies with increased sample sizes and longitudinal monitoring may help us discern more breed-specific patterns in morbidity. Overall, the large increase in multimorbidity seen with age in dogs mirrors that seen in humans and lends even more credence to the value of companion dogs as models for human morbidity and mortality
Direct investment by stepfathers can mitigate effects on educational outcomes but does not improve behavioural difficulties
In contemporary developed populations, stepfather presence has been associated with detrimental effects on child development. However, the proximate mechanisms behind such effects are yet to be fully explored. From a behavioural ecological perspective, the negative effects associated with stepfathers may be due to the reduced quantity and quality of investments children receive within stepfather households. Here, we build on previous studies by investigating whether the effects of stepfather presence on child outcomes are driven by differences in maternal and partner (i.e., father or stepfather) direct investments. We use data from the Avon Longitudinal Study of Parents and Children to explore stepfather effects on children's educational achievement and behavioural difficulties at age 7. Our results indicate that, for educational achievement, stepfather effects are due to the lower levels of direct investments children receive. For behavioural difficulty, stepfather effects are due to multiple factors whereby stepfather presence is associated with greater difficulties independent of investment levels, and direct investments from stepfathers are ineffective. Our results suggest that the negative effects of stepfathers on child outcomes can be explained, in part, by the reduced quantity and the ineffectiveness of direct investments children receive from stepfathers. Furthermore, the effects of stepfather direct investments seem to vary between child outcomes. © 2014 The Authors
Adjustable viscoelasticity allows for efficient collective cell migration
Cell migration is essential for a wide range of biological processes such as embryo morphogenesis, wound healing, regeneration, and also in pathological conditions, such as cancer. In such contexts, cells are required to migrate as individual entities or as highly coordinated collectives, both of which requiring cells to respond to molecular and mechanical cues from their environment. However, whilst the function of chemical cues in cell migration is comparatively well understood, the role of tissue mechanics on cell migration is just starting to be studied. Recent studies suggest that the dynamic tuning of the viscoelasticity within a migratory cluster of cells, and the adequate elastic properties of its surrounding tissues, are essential to allow efficient collective cell migration in vivo. In this review we focus on the role of viscoelasticity in the control of collective cell migration in various cellular systems, mentioning briefly some aspects of single cell migration. We aim to provide details on how viscoelasticity of collectively migrating groups of cells and their surroundings is adjusted to ensure correct morphogenesis, wound healing, and metastasis. Finally, we attempt to show that environmental viscoelasticity triggers molecular changes within migrating clusters and that these new molecular setups modify clusters' viscoelasticity, ultimately allowing them to migrate across the challenging geometries of their microenvironment
Electrodermal activity measurement within a qualitative methodology: Exploring emotion in leisure experience
Purpose - Reflecting, reliving and reforming experiences enhances the longer-term effects of travel and tourism, and has been highlighted as an important aspect in determining loyalty, re-visitation and post-consumption satisfaction. The purpose of this article is to develop new methodological approaches to investigate emotion, memory creation, and the resulting psychosocial effects. Design/methodology/approach - The paper proposes a unique combination of physiological measures and photo-elicitation based discussions within a longitudinal design. A physiological measuring instrument (electrodermal activity tracking technology through Empatica E4 wristbands) is utilised to capture the ‘unadulterated’ emotional response both during the experience and in reliving or remembering it. This is combined with post experience narrative discussion groups using photos and other artefacts to give further understanding of the process of collective memory creation. Findings - EDA tracking can enhance qualitative research methodologies in three ways: through use as an ‘artefact’ to prompt reflection on feelings, through identifying peaks of emotional response and through highlighting changes in emotional response over time. Empirical evidence from studies into participatory arts events and the potential wellbeing effects upon women over the age of 70 are presented to illustrate the method. Originality/value - The artificial environment created using experimental approaches to measure emotions and memory (common in many fields of psychology) has serious limitations. Our paper proposes new and more ‘natural’ methods for use in tourism, hospitality and events research, which have the potential to better capture participants’ feelings, behaviours and the meanings they place upon them
Vortex deformation and breaking in superconductors: A microscopic description
Vortex breaking has been traditionally studied for nonuniform critical
current densities, although it may also appear due to nonuniform pinning force
distributions. In this article we study the case of a
high-pinning/low-pinning/high-pinning layered structure. We have developed an
elastic model for describing the deformation of a vortex in these systems in
the presence of a uniform transport current density for any arbitrary
orientation of the transport current and the magnetic field. If is above a
certain critical value, , the vortex breaks and a finite effective
resistance appears. Our model can be applied to some experimental
configurations where vortex breaking naturally exists. This is the case for
YBaCuO (YBCO) low angle grain boundaries and films on vicinal
substrates, where the breaking is experienced by Abrikosov-Josephson vortices
(AJV) and Josephson string vortices (SV), respectively. With our model, we have
experimentally extracted some intrinsic parameters of the AJV and SV, such as
the line tension and compared it to existing predictions based on
the vortex structure.Comment: 11 figures in 13 files; minor changes after printing proof
Shot/Reverse Shot: A Conversation on Architecture, Design and the Climate Emergency with Rania Ghosn, El Hadi Jazairy & Peg Rawes facilitated by Rodney Harrison
Recommended from our members
Patterns of custodial isospin violation from a composite top
In this paper we consider the effects of top-quark compositeness on the electroweak parameters T^ and S^ and the ZbLb̄L coupling. We do so by using an effective field theory analysis to identify several promising patterns of mixing between standard-model-like and vector fermions, and then analyzing simple extensions of the standard model that realize those patterns. These models illustrate four ways in which an extended O(4) symmetry, which controls the size of radiative corrections to the observables discussed, may be broken. These models may also be viewed as highly deconstructed versions of five-dimensional gauge theories dual to various strongly interacting composite Higgs theories. We comment on how our results relate to extra-dimensional models previously considered, and we demonstrate that one pattern of O(4) breaking is phenomenologically favored. © 2011 American Physical Society
On Some Open Problems in Many-Electron Theory
Mel Levy and Elliott Lieb are two of the most prominent researchers who have
dedicated their efforts to the investigation of fundamental questions in
many-electron theory. Their results have not only revolutionized the
theoretical approach of the field, but, directly or indirectly, allowed for a
quantum jump in the computational treatment of realistic systems as well. For
this reason, at the conclusion of our book where the subject is treated across
different disciplines, we have asked Mel Levy and Elliott Lieb to provide us
with some open problems, which they believe will be a worth challenge for the
future also in the perspective of a synergy among the various disciplines.Comment: "Epilogue" chapter in "Many-Electron Approaches in Physics, Chemistry
and Mathematics: A Multidisciplinary View", Volker Bach and Luigi Delle Site
Eds. pages 411-416; Book Series: Mathematical Physics Studies, Springer
International Publishing Switzerland, 2014. The original title has been
modified in order to clarify the subject of the chapter out of the context of
the boo
A review of the factors involved in older people's decision making with regard to influenza vaccination: a literature review
Aims and objectives. The aim of this paper was to develop an understanding of the factors involved in older people's decision making with regard to influenza vaccination to inform strategies to improve vaccine uptake and reduce morbidity and mortality.
Background. Influenza is a major cause of morbidity and mortality world-wide. In the UK, it accounts for 3000–6000 deaths annually; 85% of these deaths are people aged 65 and over. Despite this, and the widespread and costly annual government campaigns, some older people at risk of influenza and the associated complications remain reluctant to take advantage of the offer of vaccination.
Methods. A review of the English language literature referring to older people published between 1996 and 2005 was the method used. Inclusion and exclusion criteria were identified and applied.
Results. The majority of the literature was quantitative in nature, investigating personal characteristics thought to be predictors of uptake, such as age, sex, co-morbidity, educational level, income and area of residence. However, there was little discussion of the possible reasons for the significance of these factors and conflict between findings was often evident, particularly between studies employing different methodologies. Other factors identified were prior experience, concerns about the vaccine, perceived risk and advice and information.
Relevance to clinical practice. The wealth of demographic information available will be useful at a strategic level in targeting groups identified as being unlikely to accept vaccination. However, the promotion of person-centred ways of working that value the health beliefs, attitudes, perceptions and subjective experiences of older people is likely to be more successful during individual encounters designed to promote acceptance. Without more research in investigating these concepts, our understanding is inevitably limited
- …