616 research outputs found
Novel lines of Pax6-/- embryonic stem cells exhibit reduced neurogenic capacity without loss of viability
<p>Abstract</p> <p>Background</p> <p>Embryonic stem (ES) cells can differentiate into all cell types and have been used extensively to study factors affecting neuronal differentiation. ES cells containing mutations in known genes have the potential to provide useful in vitro models for the study of gene function during neuronal differentiation. Recently, mouse ES cell lines lacking the neurogenic transcription factor Pax6 were reported; neurons derived from these <it>Pax6</it><sup>-/- </sup>ES cells died rapidly after neuronal differentiation in vitro.</p> <p>Results</p> <p>Here we report the derivation of new lines of <it>Pax6</it><sup>-/- </sup>ES cells and the assessment of their ability to survive and differentiate both in vitro and in vivo. Neurons derived from our new <it>Pax6</it><sup>-/- </sup>lines were viable and continued to elaborate processes in culture under conditions that resulted in the death of neurons derived from previously reported <it>Pax6</it><sup>-/- </sup>ES cell lines. The new lines of <it>Pax6</it><sup>-/-</sup>ES cells showed reduced neurogenic potential, mimicking the effects of loss of Pax6 in vivo. We used our new lines to generate <it>Pax6</it><sup>-/- </sup>↔ <it>Pax6</it><sup>+/+ </sup>chimeras in which the mutant cells survived and displayed the same phenotypes as <it>Pax6</it><sup>-/- </sup>cells in <it>Pax6</it><sup>-/- </sup>↔ <it>Pax6</it><sup>+/+ </sup>chimeras made by embryo aggregation.</p> <p>Conclusions</p> <p>We suggest that loss of Pax6 from ES cells reduces their neurogenic capacity but does not necessarily result in the death of derived neurons. We offer these new lines as additional tools for those interested in the generation of chimeras and the analysis of in vitro ES cell models of Pax6 function during neuronal differentiation, embryonic and postnatal development.</p
Do self-reported intentions predict clinicians behaviour: a systematic review.
Background: Implementation research is the scientific study of methods to promote the systematic uptake of
clinical research findings into routine clinical practice. Several interventions have been shown to be effective in
changing health care professionals' behaviour, but heterogeneity within interventions, targeted behaviours, and
study settings make generalisation difficult. Therefore, it is necessary to identify the 'active ingredients' in
professional behaviour change strategies. Theories of human behaviour that feature an individual's "intention" to
do something as the most immediate predictor of their behaviour have proved to be useful in non-clinical
populations. As clinical practice is a form of human behaviour such theories may offer a basis for developing a
scientific rationale for the choice of intervention to use in the implementation of new practice. The aim of this
review was to explore the relationship between intention and behaviour in clinicians and how this compares to
the intention-behaviour relationship in studies of non-clinicians.
Methods: We searched: PsycINFO, MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled
Trials, Science/Social science citation index, Current contents (social & behavioural med/clinical med), ISI
conference proceedings, and Index to Theses. The reference lists of all included papers were checked manually.
Studies were eligible for inclusion if they had: examined a clinical behaviour within a clinical context, included
measures of both intention and behaviour, measured behaviour after intention, and explored this relationship
quantitatively. All titles and abstracts retrieved by electronic searching were screened independently by two
reviewers, with disagreements resolved by discussion.
Discussion: Ten studies were found that examined the relationship between intention and clinical behaviours in
1623 health professionals. The proportion of variance in behaviour explained by intention was of a similar
magnitude to that found in the literature relating to non-health professionals. This was more consistently the case
for studies in which intention-behaviour correspondence was good and behaviour was self-reported. Though firm
conclusions are limited by a smaller literature, our findings are consistent with that of the non-health professional
literature. This review, viewed in the context of the larger populations of studies, provides encouragement for
the contention that there is a predictable relationship between the intentions of a health professional and their
subsequent behaviour. However, there remain significant methodological challenges
Estimating relative survival among people registered with cancer in England and Wales
Because routinely collected survival data for cancer patients in England and Wales do not typically specify cause of death, conventional estimates of survival in cancer patients based on such data are a measure of their mortality from all causes rather than their mortality due to cancer. As a result, trends in survival over time are difficult to interpret because changes in overall survival may well reflect changes in the risk of death from other causes, rather than from the cancer of interest. One way of overcoming this problem is to use some form of ‘relative survival’ defined as a measure of survival corrected for the effect of other independent causes of death. Since this concept was first introduced, various methods for calculating relative survival have been proposed and this had led to some confusion as to the most appropriate choice of estimate. This paper aims to provide an introduction to the concept of relative survival and reviews some of the suggested methods of estimation. In addition, a particularly simple, but robust approach, is highlighted based on expected and observed mortality. This method is illustrated using preliminary data from the Office for National Statistics on cancer survival in patients born after 1939 and diagnosed with cancer during 1972–84. The examples presented, although limited to analyses on a small number of selected sites, highlight some encouraging trends in survival in people aged under 35 diagnosed with leukaemia, Hodgkin's disease and testicular cancer during this period. © 1999 Cancer Research Campaig
Living between languages: The politics of translation in Leila Aboulela’s Minaret and Xiaolu Guo’s A Concise Chinese-English Dictionary for Lovers
This is the author's final draft post-refereeing as published in The Journal of Commonwealth Literature 2012 47: 207 DOI:10.1177/0021989412440433. The online version of this article can be found at: http://jcl.sagepub.com/content/47/2/20
GLAST: Understanding the High Energy Gamma-Ray Sky
We discuss the ability of the GLAST Large Area Telescope (LAT) to identify,
resolve, and study the high energy gamma-ray sky. Compared to previous
instruments the telescope will have greatly improved sensitivity and ability to
localize gamma-ray point sources. The ability to resolve the location and
identity of EGRET unidentified sources is described. We summarize the current
knowledge of the high energy gamma-ray sky and discuss the astrophysics of
known and some prospective classes of gamma-ray emitters. In addition, we also
describe the potential of GLAST to resolve old puzzles and to discover new
classes of sources.Comment: To appear in Cosmic Gamma Ray Sources, Kluwer ASSL Series, Edited by
K.S. Cheng and G.E. Romer
HIV/AIDS Stigma and Refusal of HIV Testing Among Pregnant Women in Rural Kenya: Results from the MAMAS Study
HIV/AIDS stigma is a common thread in the narratives of pregnant women affected by HIV/AIDS globally and may be associated with refusal of HIV testing. We conducted a cross-sectional study of women attending antenatal clinics in Kenya (N = 1525). Women completed an interview with measures of HIV/AIDS stigma and subsequently information on their acceptance of HIV testing was obtained from medical records. Associations of stigma measures with HIV testing refusal were examined using multivariate logistic regression. Rates of anticipated HIV/AIDS stigma were high—32% anticipated break-up of their relationship, and 45% anticipated losing their friends. Women who anticipated male partner stigma were more than twice as likely to refuse HIV testing, after adjusting for other individual-level predictors (OR = 2.10, 95% CI: 1.15–3.85). This study demonstrated quantitatively that anticipations of HIV/AIDS stigma can be barriers to acceptance of HIV testing by pregnant women and highlights the need to develop interventions that address pregnant women’s fears of HIV/AIDS stigma and violence from male partners
The Cassava Genome: Current Progress, Future Directions
The starchy swollen roots of cassava provide an essential food source for nearly a billion people, as well as possibilities for bioenergy, yet improvements to nutritional content and resistance to threatening diseases are currently impeded. A 454-based whole genome shotgun sequence has been assembled, which covers 69% of the predicted genome size and 96% of protein-coding gene space, with genome finishing underway. The predicted 30,666 genes and 3,485 alternate splice forms are supported by 1.4 M expressed sequence tags (ESTs). Maps based on simple sequence repeat (SSR)-, and EST-derived single nucleotide polymorphisms (SNPs) already exist. Thanks to the genome sequence, a high-density linkage map is currently being developed from a cross between two diverse cassava cultivars: one susceptible to cassava brown streak disease; the other resistant. An efficient genotyping-by-sequencing (GBS) approach is being developed to catalog SNPs both within the mapping population and among diverse African farmer-preferred varieties of cassava. These resources will accelerate marker-assisted breeding programs, allowing improvements in disease-resistance and nutrition, and will help us understand the genetic basis for disease resistance
Hyperon Photoproduction in the Nucleon Resonance Region
Cross-sections and recoil polarizations for the reactions gamma + p --> K^+ +
Lambda and gamma + p --> K^+ + Sigma^0 have been measured with high statistics
and with good angular coverage for center-of-mass energies between 1.6 and 2.3
GeV. In the K^+Lambda channel we confirm a structure near W=1.9 GeV at backward
kaon angles, but our data shows a more complex s- and u- channel resonance
structure than previously seen. This structure is present at forward and
backward angles but not central angles, and its position and width change with
angle, indicating that more than one resonance is playing a role. Rising
back-angle cross sections at higher energies and large positive polarization at
backward angles are consistent with sizable s- or u-channel contributions. None
of the model calculations we present can consistently explain these aspects of
the data.Comment: 5 pages, 3 figures, submitted to Physical Review Letter
A mixed methods study of hope, transitions, and quality of life in family caregivers of persons with Alzheimer's disease
<p>Abstract</p> <p>Background</p> <p>Several research studies have reported the poor quality of life of family caregivers of persons with Alzheimer's disease (AD). However, factors that influence their quality of life have not been clearly defined. The purpose of this study was to examine factors associated with the quality of life of these caregivers such as demographic variables, their transition experience, and hope. A secondary aim was to explore the transition experience of family caregivers of persons with AD.</p> <p>Methods</p> <p>A cross-sectional triangulation data transformation model mixed method design (Quant +Qual) was utilized to address the purpose of the study. Eighty family caregivers of persons with AD completed a survey with quantitative measures [demographic variables, Herth Hope Index (HHI-hope), World Health Organization Quality of Life -BREF (WHOQOL-BREF)] and a qualitative survey about their transitions experience. The qualitative data (transition open ended- survey) was converted to quantitative data using content analysis. Variables significant at the p < 0.10 level in the univariate analysis were entered in the multivariate generalized linear model used to determine significant factors associated with quality of life.</p> <p>Results</p> <p>Subjects with higher hope scores (p < 0.0001) (Factor 1: temporality and future-cognitive-temporary dimension of hope) and who dealt with their transitions by actively seeking out knowledge and assistance (p = 0.02) had higher overall quality of life scores. HHI scores were associated with overall quality of life and for each of the four quality of life domains (physical psychosocial, relationships, and environment).</p> <p>Conclusions</p> <p>Hope played a significant role in the subjects' perceptions of overall quality of life as well as the 4 quality of life domains. This underscores the need to develop ways to foster hope in family caregivers. Moreover, the active engagement of families in seeking information and help, as a way to deal with their transitions, suggests encouraging this engagement is important. The findings of this study also suggest many directions for future research, such as increasing our understanding of the processes of transitions for this population.</p
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