169 research outputs found
Exploring trainer and trainee emotional talk in narratives about workplace-based feedback processes
Emotion characterises learners' feedback experiences. While the failure-to-fail literature suggests that emotion may be important, little is known about the role of emotion for educators. Secondary analyses were therefore conducted on data exploring 110 trainers' and trainees' feedback experiences. Group and individual narrative interviews were conducted across three UK sites. We analysed 333 narratives for emotional talk using textual analysis: Linguistic Inquiry and Word Count. Furthermore, thematic framework analysis was conducted on the trainer narratives to explore aspects of feedback processes that are emotional. An additional in-depth little 'd' discourse analysis was conducted on selected trainer narratives to enable us to explore the complex relationship between the whats (reported events) and the hows (emotional talk). Trainer narratives did not differ significantly in positive or negative emotional talk from trainee narratives. By exploring the interplay of the whats and the hows, several aspects of feedback processes were identified as potentially emotional for trainers including trainers being concerned about upsetting learners and worried about patient safety. This was illustrated through numerous linguistic devices to establish emotional tone such as metaphoric talk and laughter. These findings suggest that feedback processes can be emotional for trainers. It highlights the need to better understand the 'filter' of emotion for trainers but also to better understand how emotion plays a role in feedback as a complex social process.</p
Production properties of K*(892) vector mesons and their spin alignment as measured in the NOMAD experiment
First measurements of K*(892) mesons production properties and their spin
alignment in nu_mu charged current (CC) and neutral current (NC) interactions
are presented. The analysis of the full data sample of the NOMAD experiment is
performed in different kinematic regions. For K*+ and K*- mesons produced in
nu_mu CC interactions and decaying into K0 pi+/- we have found the following
yields per event: (2.6 +/- 0.2 (stat.) +/- 0.2 (syst.))% and (1.6 +/- 0.1
(stat.) +/- 0.1 (syst.))% respectively, while for the K*+ and K*- mesons
produced in nu NC interactions the corresponding yields per event are: (2.5 +/-
0.3 (stat.) +/- 0.3 (syst.))% and (1.0 +/- 0.3 (stat.) +/- 0.2 (syst.))%. The
results obtained for the rho00 parameter, 0.40 +/- 0.06 (stat) +/- 0.03 (syst)
and 0.28 +/- 0.07 (stat) +/- 0.03 (syst) for K*+ and K*- produced in nu_mu CC
interactions, are compared to theoretical predictions tuned on LEP measurements
in e+e- annihilation at the Z0 pole. For K*+ mesons produced in nu NC
interactions the measured rho00 parameter is 0.66 +/- 0.10 (stat) +/- 0.05
(syst).Comment: 20 p
Mechanism of subunit interaction at ketosynthase-dehydratase junctions in trans-AT polyketide synthases
Modular polyketide synthases (PKSs) produce numerous structurally complex natural products with diverse applications in medicine and agriculture. They typically consist of several multienzyme subunits that utilize structurally-defined docking domains (DDs) at their N- and C-termini to ensure correct assembly into functional multi-protein complexes. Here we report a fundamentally different mechanism for subunit assembly in trans-AT modular PKSs at the junction between ketosynthase (KS) and dehydratase (DH) domains. This involves direct interaction of a largely unstructured docking domain (DD) at the C-terminus of the KS with the surface of the downstream DH. Acyl transfer assays and mechanism-based cross-linking established that the DD is required for the KS to communicate with the acyl carrier protein appended to the DH. Two distinct regions for binding of the DD to the DH were identified using NMR spectroscopy, carbene foot-printing and mutagenesis, providing a foundation for future elucidation of the molecular basis for interaction specificity
Sequenceserver: A Modern Graphical User Interface for Custom BLAST Databases
Comparing newly obtained and previously known nucleotide and amino-acid sequences underpins modern biological research. BLAST is a well-established tool for such comparisons but is challenging to use on new data sets. We combined a user-centric design philosophy with sustainable software development approaches to create Sequenceserver, a tool for running BLAST and visually inspecting BLAST results for biological interpretation. Sequenceserver uses simple algorithms to prevent potential analysis errors and provides flexible text-based and visual outputs to support researcher productivity. Our software can be rapidly installed for use by individuals or on shared servers
Effects of luteectomy in early pregnancy on the maintenance of gestation and plasma progesterone concentrations in the viviparous temperate lizard Barisia imbricata imbricata
<p>Abstract</p> <p>Background</p> <p>Several studies have shown that the corpus luteum is the principal source of progesterone during the gravidity period in reptiles; however, its participation in the maintenance of gestation in the viviparous squamata is in dispute. The effects of ovariectomy or luteectomy vary according to the species and the time at which the procedure is performed. In this paper, we describe the effects of luteectomy during early pregnancy on the maintenance of gestation and progesterone concentrations in the temperate Mexican viviparous lizard <it>Barisia imbricata imbricata.</it></p> <p>Methods</p> <p>Twenty-four lizards were subjected to three different treatments: luteectomy, sham luteectomy or non-surgical treatment, and blood samples were obtained before and after surgical treatment at different stages of gestation to determine the effects of luteectomy on the maintenance of gestation and progesterone concentrations.</p> <p>Results</p> <p>Spontaneous abortion was not observed in any of the females. However, luteectomy provoked abnormal parturition and a significant reduction in the number of young born alive. Parturition was normal in untreated females as well as those submitted to sham luteectomy. The surgical treatment also caused a significant reduction in progesterone concentrations in luteectomised females during early and middle gestation. However, no significant differences in hormone concentrations were observed among the three groups during late gestation or immediately post-parturition.</p> <p>Conclusions</p> <p>Our observations indicate that the presence of the corpus luteum is not necesary for the maintenance of gestation, but that it does participate in parturition control. Moreover, the corpus luteum of the viviparous lizard <it>B. i. imbricata</it> produces progesterone, at least during the first half of pregnancy, and that an extra-ovarian source of progesterone must maintain gestation in the absence of luteal tissue.</p
A Randomized Placebo-Controlled Trial of Intermittent Preventive Treatment in Pregnant Women in the Context of Insecticide Treated Nets Delivered through the Antenatal Clinic
Background:Current recommendations to prevent malaria in African pregnant women rely on insecticide treated nets(ITNs) and intermittent preventive treatment (IPTp). However, there is no information on the safety and efficacy of theircombined use.Methods:1030 pregnant Mozambican women of all gravidities received a long-lasting ITN during antenatal clinic (ANC)visits and, irrespective of HIV status, were enrolled in a randomised, double blind, placebo-controlled trial, to assess thesafety and efficacy of 2-dose sulphadoxine-pyrimethamine (SP). The main outcome was the reduction in low birth weight.Findings:Two-dose SP was safe and well tolerated, but was not associated with reductions in anaemia prevalence atdelivery (RR, 0.92 [95% CI, 0.79-1.08]), low birth weight (RR, 0.99 [95% CI, 0.70-1.39]), or overall placental infection(p = 0.964). However, the SP group showed a 40% reduction (95% CI, 7.40-61.20]; p = 0.020) in the incidence of clinicalmalaria during pregnancy, and reductions in the prevalence of peripheral parasitaemia (7.10% vs 15.15%) (p,0.001), and ofactively infected placentas (7.04% vs 13.60%) (p = 0.002). There was a reduction in severe anaemia at delivery of borderlinestatistical significance (p = 0.055). These effects were not modified by gravidity or HIV status. Reported ITN's use was morethan 90% in both groups.Conclusions:Two-dose SP was associated with a reduction in some indicators, but these were not translated to significantimprovement in other maternal or birth outcomes. The use of ITNs during pregnancy may reduce the need to administerIPTp. ITNs should be part of the ANC package in sub-Saharan Afric
Endocrine Activity of Extraembryonic Membranes Extends beyond Placental Amniotes
BACKGROUND. During development, all amniotes (mammals, reptiles, and birds) form extraembryonic membranes, which regulate gas and water exchange, remove metabolic wastes, provide shock absorption, and transfer maternally derived nutrients. In viviparous (live-bearing) amniotes, both extraembryonic membranes and maternal uterine tissues contribute to the placenta, an endocrine organ that synthesizes, transports, and metabolizes hormones essential for development. Historically, endocrine properties of the placenta have been viewed as an innovation of placental amniotes. However, an endocrine role of extraembryonic membranes has not been investigated in oviparous (egg-laying) amniotes despite similarities in their basic structure, function, and shared evolutionary ancestry. In this study, we ask whether the oviparous chorioallantoic membrane (CAM) of chicken (Gallus gallus) has the capability to synthesize and receive signaling of progesterone, a major placental steroid hormone. METHODOLOGY/PRINCIPAL FINDINGS. We quantified mRNA expression of key steroidogenic enzymes involved in progesterone synthesis and found that 3β-hydroxysteroid dehydrogenase, which converts pregnenolone to progesterone exhibited a 464 fold increase in the CAM from day 8 to day 18 of embryonic development (F5, 68=89.282, p<0.0001). To further investigate progesterone synthesis, we performed explant culture and found that the CAM synthesizes progesterone in vitro in the presence of a steroid precursor. Finally, we quantified mRNA expression and performed protein immunolocalization of the progesterone receptor in the CAM. CONCLUSIONS/SIGNIFICANCE. Collectively, our data indicate that the chick CAM is steroidogenic and has the capability to both synthesize progesterone and receive progesterone signaling. These findings represent a paradigm shift in evolutionary reproductive biology by suggesting that endocrine activity of extraembryonic membranes is not a novel characteristic of placental amniotes. Rather, we hypothesize that these membranes may share an additional unifying characteristic, steroidogenesis, across amniotes at large.Sigma Xi (G20073141634396861); National Science Foundation (2008059161); UF-Howard Hughes G.A.T.O.R. Program; Howard Hughes Medical Institute Professorshi
From monogenic to polygenic obesity: recent advances
The heritability of obesity and body weight in general is high. A small number of confirmed monogenic forms of obesity—the respective mutations are sufficient by themselves to cause the condition in food abundant societies—have been identified by molecular genetic studies. The elucidation of these genes, mostly based on animal and family studies, has led to the identification of important pathways to the disorder and thus to a deeper understanding of the regulation of body weight. The identification of inborn deficiency of the mostly adipocyte-derived satiety hormone leptin in extremely obese children from consanguineous families paved the way to the first pharmacological therapy for obesity based on a molecular genetic finding. The genetic predisposition to obesity for most individuals, however, has a polygenic basis. A polygenic variant by itself has a small effect on the phenotype; only in combination with other predisposing variants does a sizeable phenotypic effect arise. Common variants in the first intron of the ‘fat mass and obesity associated’ gene (FTO) result in an elevated body mass index (BMI) equivalent to approximately +0.4 kg/m² per risk allele. The FTO variants were originally detected in a genome wide association study (GWAS) pertaining to type 2 diabetes mellitus. Large meta-analyses of GWAS have subsequently identified additional polygenic variants. Up to December 2009, polygenic variants have been confirmed in a total of 17 independent genomic regions. Further study of genetic effects on human body weight regulation should detect variants that will explain a larger proportion of the heritability. The development of new strategies for diagnosis, treatment and prevention of obesity can be anticipated
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats
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