3,073 research outputs found
Gut-seeded α-synuclein fibrils promote gut dysfunction and brain pathology specifically in aged mice
Parkinson’s disease is a synucleinopathy that is characterized by motor dysfunction, death of midbrain dopaminergic neurons and accumulation of α-synuclein (α-Syn) aggregates. Evidence suggests that α-Syn aggregation can originate in peripheral tissues and progress to the brain via autonomic fibers. We tested this by inoculating the duodenal wall of mice with α-Syn preformed fibrils. Following inoculation, we observed gastrointestinal deficits and physiological changes to the enteric nervous system. Using the AAV-PHP.S capsid to target the lysosomal enzyme glucocerebrosidase for peripheral gene transfer, we found that α-Syn pathology is reduced due to the increased expression of this protein. Lastly, inoculation of α-Syn fibrils in aged mice, but not younger mice, resulted in progression of α-Syn histopathology to the midbrain and subsequent motor defects. Our results characterize peripheral synucleinopathy in prodromal Parkinson’s disease and explore cellular mechanisms for the gut-to-brain progression of α-Syn pathology
Experimental evidence that browsing for activewear lowers explicit body image attitudes and implicit self-esteem in women
Online apparel shopping is popular amongst women and offers salient visual information for making body image and self-worth judgements. Apparel segments which emphasize the value of women\u27s bodies are particularly effective for eliciting low body image and self-worth. Across two studies, we investigated the association between self-reported and experimental online activewear exposure on women\u27s self-worth, body image, appearance attitudes, mood and gaze behavior. In Study 1, participants (N = 399) completed a survey collecting their online apparel shopping habits, body appreciation, self-esteem, appearance comparison tendencies and self-objectification attitudes. Activewear was the second-most popular apparel segment amongst women (after casualwear) and weekly activewear browse time was positively correlated with appearance comparison tendencies, desires to be muscular/athletic and body shame. In Study 2, participants (N = 126) were randomly allocated to browse an activewear, casualwear or homewares website and completed pre and post measures of mood, body image, implicit self-esteem and body gaze behavior. In the activewear condition, there was a significant reduction in positive body image and implicit self-esteem scores. There were no experimental effects for body gaze behavior. These findings illustrate that apparel choices have value for understanding the aetiology of maladaptive body image attitudes and low self-esteem in women
Transformation as Development: Southern Africa Perspectives on Capacity Building and Heritage
As an agenda for development, ‘transformation’ invokes the long-standing and (in South Africa) constitutionally supported struggle for redistributive socioeconomic rights. This chapter brings experiences from two different sorts of heritage management programs to bear on discussions of transformation as development: the Metolong Cultural Resource Management Project associated with Lesotho’s Metolong Dam, and the Matatiele Archaeology and Rock Art program as a National Research Foundation-funded academic project, both of which included capacity building components. Tracing their paths—and the expectations for heritage that they entailed—reveals where invoking heritage as a platform for capacity building too often works against the cause of empowerment. In this chapter, we disarticulate received narratives of transformation, community engagement, and development, identifying tensions and concerns that emerge in practical examples. We highlight issues surrounding credentialing trainees, knowledge production and the creation of expert/technician divides, and recommend policies for the southern African heritage sector to address these
Solitary-wave description of condensate micro-motion in a time-averaged orbiting potential trap
We present a detailed theoretical analysis of micro-motion in a time-averaged
orbiting potential trap. Our treatment is based on the Gross-Pitaevskii
equation, with the full time dependent behaviour of the trap systematically
approximated to reduce the trapping potential to its dominant terms. We show
that within some well specified approximations, the dynamic trap has
solitary-wave solutions, and we identify a moving frame of reference which
provides the most natural description of the system. In that frame eigenstates
of the time-averaged orbiting potential trap can be found, all of which must be
solitary-wave solutions with identical, circular centre of mass motion in the
lab frame. The validity regime for our treatment is carefully defined, and is
shown to be satisfied by existing experimental systems.Comment: 12 pages, 2 figure
Mechanics Of The Foot And Ankle Joints During Running Using A Multi-Segment Foot Model Compared With A Single-Segment Model
The primary purpose of this study was to compare the ankle joint mechanics, during the stance phase of running, computed with a multi-segment foot model (MULTI; three segments) with a traditional single segment foot model (SINGLE). Traditional ankle joint models define all bones between the ankle and metatarsophalangeal joints as a single rigid segment (SINGLE). However, this contrasts with the more complex structure and mobility of the human foot, recent studies of walking using more multiple-segment models of the human foot have highlighted the errors arising in ankle kinematics and kinetics by using an oversimplified model of the foot. This study sought to compare whether ankle joint kinematics and kinetics during running are similar when using a single segment foot model (SINGLE) and a multi-segment foot model (MULTI). Seven participants ran at 3.1 m/s while the positions of markers on the shank and foot were tracked and ground reaction forces were measured. Ankle joint kinematics, resultant joint moments, joint work, and instantaneous joint power were determined using both the SINGLE and MULTI models. Differences between the two models across the entire stance phase were tested using statistical parametric mapping. During the stance phase, MULTI produced ankle joint angles that were typically closer to neutral and angular velocities that were reduced compared with SINGLE. Instantaneous joint power (
Client self-assessment in community aged care: A comparative study involving older Australians and their case managers
Self-assessment of support needs is a relatively new and under-researched phenomenon in domiciliary aged care. This article outlines the results of a comparative study focusing on whether a self-assessment approach assists clients to identify support needs and the degree to which self-assessed needs differ from an assessment conducted by community care professionals. A total of 48 older people and their case managers completed a needs assessment tool. Twenty-two semi-structured interviews were used to ascertain older people’s views and preferences regarding the self-assessment process. The study suggests that while a co-assessment approach as outlined in this article has the potential to assist older people to gain a better understanding of their care needs as well as the assessment process and its ramifications, client self-assessment should be seen as part of a co-assessment process involving care professionals. Such a co-assessment process allows older people to gain a better understanding of their support needs and the wider community aged care context. The article suggests that a co-assessment process involving both clients and care professionals contains features that have the capacity to enhance domiciliary aged care
Bragg scattering of Cooper pairs in an ultra-cold Fermi gas
We present a theoretical treatment of Bragg scattering of a degenerate Fermi
gas in the weakly interacting BCS regime. Our numerical calculations predict
correlated scattering of Cooper pairs into a spherical shell in momentum space.
The scattered shell of correlated atoms is centered at half the usual Bragg
momentum transfer, and can be clearly distinguished from atoms scattered by the
usual single-particle Bragg mechanism. We develop an analytic model that
explains key features of the correlated-pair Bragg scattering, and determine
the dependence of this scattering on the initial pair correlations in the gas.Comment: Manuscript substantially revised. Version 2 contains a more detailed
discussion of the collisional interaction used in our theory, and is based on
three-dimensional solution
Developing the evidence base for adult social care practice: The NIHR School for Social Care Research
In a foreword to 'Shaping the Future of Care Together', Prime Minister Gordon Brown says that a care and support system reflecting the needs of our times and meeting our rising aspirations is achievable, but 'only if we are prepared to rise to the challenge of radical reform'. A number of initiatives will be needed to meet the challenge of improving social care for the growing older population. Before the unveiling of the green paper, The National Institute for Health Research (NIHR) announced that it has provided 15m pounds over a five-year period to establish the NIHR School for Social Care Research. The School's primary aim is to conduct or commission research that will help to improve adult social care practice in England. The School is seeking ideas for research topics, outline proposals for new studies and expert advice in developing research methods
Nonlinear atom-optical delta-kicked harmonic oscillator using a Bose-Einstein condensate
We experimentally investigate the atom-optical delta-kicked harmonic
oscillator for the case of nonlinearity due to collisional interactions present
in a Bose-Einstein condensate. A Bose condensate of rubidium atoms tightly
confined in a static harmonic magnetic trap is exposed to a one-dimensional
optical standing-wave potential that is pulsed on periodically. We focus on the
quantum anti-resonance case for which the classical periodic behavior is simple
and well understood. We show that after a small number of kicks the dynamics is
dominated by dephasing of matter wave interference due to the finite width of
the condensate's initial momentum distribution. In addition, we demonstrate
that the nonlinear mean-field interaction in a typical harmonically confined
Bose condensate is not sufficient to give rise to chaotic behavior.Comment: 4 pages, 3 figure
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