Predictors of the groupwork experience: generic skill development, peer appraisals, and country of residence

Humphrey et al. (1997) argued that a range of generic skills are important in enhancing the experience of groupwork for students. These skills include problem solving skills, leadership skills, research skills, study skills, and communication skills. However, little is known about the extent to which the development of such skills impact on the students' experience of groupwork, Students are also rarely given opportunities to develop their performance management skills in group assignments, despite often being expected to evaluate the performance of their peers. Those doing the appraisal may not learn how to provide feedback and justify their evaluations. It also means that those being appraised do not receive feedback regarding their strengths and whereimprovements are needed. As a consequence, students tend to report negative experiences of groupwork when they have to assess and be assessed by their peers. The current study aims to examine the effects of generic skill development and peerevaluation on the students' evaluation of their group experience, following their participation on a group assignment

A cross-sectional survey of water and clean faces in trachoma endemic communities in Tanzania

<p>Abstract</p> <p>Background</p> <p>Face washing is important to interrupt the transmission of trachoma, the leading infectious cause of blindness worldwide. We aimed to assess the household and personal factors that affected water use and face washing practices in Kongwa, Tanzania.</p> <p>Methods</p> <p>We conducted a household water use survey in 173 households (329 children) in January, 2010. Self reported data on water use practices, observed water in the household, and observed clean faces in children were collected. Contingency table analyses and logistic regression analyses were used to measure associations between unclean faces and risk factors.</p> <p>Results</p> <p>We found that women are recognized as primary decision makers on water use in a household, and respondents who reported laziness as a reason that others do not wash children's faces were significantly more likely to have children with clean faces. Washing was reported as a priority for water use in most households. Sixty four percent (95% Confidence Interval = 59%-70%) of children had clean faces.</p> <p>Conclusions</p> <p>Attitudes toward face washing and household water use appear to have changed dramatically from 20 years ago when clean faces were rare and men made decisions on water use in households. The sources of these attitudinal changes are not clear, but are positive changes that will assist the trachoma control program in strengthening its hygiene efforts.</p

Phasic Phosphorylation of Caldesmon and ERK 1/2 during Contractions in Human Myometrium

Human myometrium develops phasic contractions during labor. Phosphorylation of caldesmon (h-CaD) and extracellular signal-regulated kinase 1/2 (ERK 1/2) has been implicated in development of these contractions, however the phospho-regulation of these proteins is yet to be examined during periods of both contraction and relaxation. We hypothesized that protein phosphorylation events are implicated in the phasic nature of myometrial contractions, and aimed to examine h-CaD and ERK 1/2 phosphorylation in myometrium snap frozen at specific stages, including; (1) prior to onset of contractions, (2) at peak contraction and (3) during relaxation. We aimed to compare h-CaD and ERK 1/2 phosphorylation in vitro against results from in vivo studies that compared not-in-labor (NIL) and laboring (L) myometrium. Comparison of NIL (n = 8) and L (n = 8) myometrium revealed a 2-fold increase in h-CaD phosphorylation (ser-789; P = 0.012) during onset of labor in vivo, and was associated with significantly up-regulated ERK2 expression (P = 0.022), however no change in ERK2 phosphorylation was observed (P = 0.475). During in vitro studies (n = 5), transition from non-contracting tissue to tissue at peak contraction was associated with increased phosphorylation of both h-CaD and ERK 1/2. Furthermore, tissue preserved at relaxation phase exhibited diminished levels of h-CaD and ERK 1/2 phosphorylation compared to tissue preserved at peak contraction, thereby producing a phasic phosphorylation profile for h-CaD and ERK 1/2. h-CaD and ERK 1/2 are phosphorylated during myometrial contractions, however their phospho-regulation is dynamic, in that h-CaD and ERK 1/2 are phosphorylated and dephosphorylated in phase with contraction and relaxation respectively. Comparisons of NIL and L tissue are at risk of failing to detect these changes, as L samples are not necessarily preserved in the midst of an active contraction

The association between atopic eczema and lymphopenia: results from a UK cohort study with replication in US survey data.

BACKGROUND: Lymphocyte skin homing in atopic eczema (AE) may induce lymphopenia. OBJECTIVE: To determine if AE is associated with lymphopenia. METHODS: We used UK primary care electronic health records (Clinical Practice Research Datalink GOLD) for a matched cohort study in adults (18yrs+) (1997-2015) with at least 1 recorded lymphocyte count. We matched people with AE to up to 5 people without. We used multivariable logistic regression to estimate the association between AE and lymphopenia (two low lymphocyte counts within 3 months) and linear mixed effects regression to estimate the association with absolute lymphocyte counts using all available counts. Cox proportional hazard models were used to investigate the effect of lymphopenia on common infections. We replicated the study using US survey data (National Health and Nutrition Examination Survey [NHANES]). RESULTS: Amongst 71,731 adults with AE and 126,349 adults without AE, we found an adjusted odds ratio (OR) for lymphopenia of 1.16 (95%CI: 1.09-1.23), the strength of association increased with increasing eczema severity. When comparing all recorded lymphocyte counts from adults with AE(n=1,497,306) to those of people without AE(n=4,035,870) we saw a lower mean lymphocyte (adjusted mean difference -0.047*109 /L (95%CI:- 0.051- -0.043)) in those with AE. The difference was larger for men, increasing age, increasing AE severity and was present among people with AE not treated with immunosuppressive drugs. In NHANES (n=22,624), the adjusted OR for lymphopenia in adults with AE was 1.30 (95% CI 0.80-2.11), and the adjusted mean lymphocyte count difference was -0.03*109 /L (95%CI -0.07-0.02). Despite having a lower lymphocyte count, adjusting for time with lymphopenia, did not alter risk estimates of infections. CONCLUSION: AE, including increasing AE severity, is associated with a decreasing lymphocyte count, regardless of immunosuppressive drug use.. Whether the decreasing lymphocyte count has wider health implications for people with severe eczema warrants further investigation

Light-Induced Fos Expression in Intrinsically Photosensitive Retinal Ganglion Cells in Melanopsin Knockout (Opn4−/−) Mice

Retinal ganglion cells that express the photopigment melanopsin are intrinsically photosensitive (ipRGCs) and exhibit robust synaptically driven ON-responses to light, yet they will continue to depolarize in response to light when all synaptic input from rod and cone photoreceptors is removed. The light-evoked increase in firing of classical ganglion cells is determined by synaptic input from ON-bipolar cells in the proximal sublamina of the inner plexiform layer. OFF-bipolar cells synapse with ganglion cell dendrites in the distal sublamina of the inner plexiform layer. Of the several types of ipRGC that have been described, M1 ipRGCs send dendrites exclusively into the OFF region of the inner plexiform layer where they stratify near the border of the inner nuclear layer. We tested whether M1 ipRGCs with dendrites restricted to the OFF sublamina of the inner plexiform layer receive synaptic ON-bipolar input by examining light-induced gene expression in vivo using melanopsin knockout mice. Mice in which both copies of the melanopsin gene (opn4) have been replaced with the tau-lacZ gene (homozygous tau-lacZ+/+ knockin mice) are melanopsin knockouts (opn4−/−) but M1 ipRGCs are specifically identified by their expression of β-galactosidase. Approximately 60% of M1 ipRGCs in Opn4−/− mice exposed to 3 hrs of light expressed c-Fos; no β-galactosidase-positive RGCs expressed c-Fos in the dark. Intraocular application of L-AP4, a compound which blocks transmission of visual signals between photoreceptors and ON-bipolar cells significantly reduced light-evoked c-Fos expression in M1 ipRGCs compared to saline injected eyes (66% saline vs 27% L-AP4). The results are the first description of a light-evoked response in an ipRGC lacking melanopsin and provide in vivo confirmation of previous in vitro observations illustrating an unusual circuit in the retina in which ganglion cells sending dendrites to the OFF sublamina of the inner plexiform layer receive excitatory synaptic input from ON-bipolar cells

Cellular Radiosensitivity: How much better do we understand it?

Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies. Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation

A uniform procedure for the purification of CDK7/CycH/MAT1, CDK8/CycC and CDK9/CycT1

We have established a uniform procedure for the expression and purification of the cyclin-dependent kinases CDK7/CycH/MAT1, CDK8/CycC and CDK9/CycT1. We attach a His(6)-tag to one of the subunits of each complex and then co-express it together with the other subunits in Spodoptera frugiperda insect cells. The CDK complexes are subsequently purified by Ni(2+)-NTA and Mono S chromatography. This approach generates large amounts of active recombinant kinases that are devoid of contaminating kinase activities. Importantly, the properties of these recombinant kinases are similar to their natural counterparts (Pinhero et al. 2004, Eur J Biochem 271:1004-14). Our protocol provides a novel systematic approach for the purification of these three (and possibly other) recombinant CDKs

Covalent Attachment of Proteins to Solid Supports and Surfaces via Sortase-Mediated Ligation

BACKGROUND: There is growing interest in the attachment of proteins to solid supports for the development of supported catalysts, affinity matrices, and micro devices as well as for the development of planar and bead based protein arrays for multiplexed assays of protein concentration, interactions, and activity. A critical requirement for these applications is the generation of a stable linkage between the solid support and the immobilized, but still functional, protein. METHODOLOGY: Solid supports including crosslinked polymer beads, beaded agarose, and planar glass surfaces, were modified to present an oligoglycine motif to solution. A range of proteins were ligated to the various surfaces using the Sortase A enzyme of S. aureus. Reactions were carried out in aqueous buffer conditions at room temperature for times between one and twelve hours. CONCLUSIONS: The Sortase A transpeptidase of S. aureus provides a general, robust, and gentle approach to the selective covalent immobilization of proteins on three very different solid supports. The proteins remain functional and accessible to solution. Sortase mediated ligation is therefore a straightforward methodology for the preparation of solid supported enzymes and bead based assays, as well as the modification of planar surfaces for microanalytical devices and protein arrays

DNA-PK-Dependent RPA2 Hyperphosphorylation Facilitates DNA Repair and Suppresses Sister Chromatid Exchange

Hyperphosphorylation of RPA2 at serine 4 and serine 8 (S4, S8) has been used as a marker for activation of the DNA damage response. What types of DNA lesions cause RPA2 hyperphosphorylation, which kinase(s) are responsible for them, and what is the biological outcome of these phosphorylations, however, have not been fully investigated. In this study we demonstrate that RPA2 hyperphosphorylation occurs primarily in response to genotoxic stresses that cause high levels of DNA double-strand breaks (DSBs) and that the DNA-dependent protein kinase complex (DNA-PK) is responsible for the modifications in vivo. Alteration of S4, S8 of RPA2 to alanines, which prevent phosphorylations at these sites, caused increased mitotic entry with concomitant increases in RAD51 foci and homologous recombination. Taken together, our results demonstrate that RPA2 hyperphosphorylation by DNA-PK in response to DSBs blocks unscheduled homologous recombination and delays mitotic entry. This pathway thus permits cells to repair DNA damage properly and increase cell viability

ULTRA-BRIGHT OPTICAL TRANSIENTS ARE LINKED WITH TYPE Ic SUPERNOVAE

Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries of SN 2005ap by the Texas Supernova Search and SCP-06F6 in a deep Hubble pencil beam survey were followed by the Palomar Transient Factory confirmation of host redshifts for other similar transients. The transients share the common properties of high optical luminosities (peak magnitudes ~−21 to −23), blue colors, and a lack of H or He spectral features. The physical mechanism that produces the luminosity is uncertain, with suggestions ranging from jet-driven explosion to pulsational pair instability. Here, we report the most detailed photometric and spectral coverage of an ultra-bright transient (SN 2010gx) detected in the Pan-STARRS 1 sky survey. In common with other transients in this family, early-time spectra show a blue continuum and prominent broad absorption lines of O ii. However, about 25 days after discovery, the spectra developed type Ic supernova features, showing the characteristic broad Fe ii and Si ii absorption lines. Detailed, post-maximum follow-up may show that all SN 2005ap and SCP-06F6 type transients are linked to supernovae Ic. This poses problems in understanding the physics of the explosions: there is no indication from late-time photometry that the luminosity is powered by 56Ni, the broad light curves suggest very large ejected masses, and the slow spectral evolution is quite different from typical Ic timescales. The nature of the progenitor stars and the origin of the luminosity are intriguing and open questions