Variable numerical-aperture temporal-coherence measurement of resonant-cavity LEDs

The first interferometric measurements of temporal-coherence length variation with numerical aperture (NA) are described for 650 nm, resonant-cavity light-emitting diodes (LEDs) agreeing with spectrally derived results. The interferometrically measured coherence length (22 mum to 32 mum) reduced by 37% for a 0.42 increase in NA. For a larger range of NA (0-1), this would give coherence lengths (10 mum-40 mum) lying in the gap between that of conventional LEDs (similar to5 mum) and superluminescent diodes (similar to60 mum)

The influence of placements on adult nursing graduates’ choice of first post

Background: This article presents findings from a study that sought to explore the extent to which clinical placements have an impact on nursing students’ decisions regarding their first staff nurse post. Within the UK, nursing is facing a recruitment crisis with particular difficulty recruiting to areas such as primary and elderly care. Transitioning into a new role is challenging in any occupation, but it is a particular problem in nursing where the realities of professional practice often differ from students’ perception of the staff nurse role as shaped by their clinical placements. Aim: This pilot study aimed to explore the influence of practice placements on final year adult nursing students’ career decisions. Method: Qualitative and quantitative data were collected in a single phase using a questionnaire distributed to nursing students on the final day of their course. A total of 35 completed questionnaires were returned (response rate 57%). Results: Half of the participants entered the course with preconceived preferences for clinical specialisms. However, only five participants (14%) applied for first destination posts in that specialism. The overall importance of placements in career choice increased across the three years of the programme. Although placements in all three years are important, the experiences in year 3 are pivotal, with 74% rankingthese as ‘significantly influential’ in their decision-making process. Analysis of the data obtained from the free-text responses from the questionnaire suggested that working environment; the level of support provided by mentors and clinical staff; the opportunity to make a difference to patients’ lives and the variety of placements, were key influences on nursing students’ decision regarding their first staff nurse post. Conclusions: This study highlights the key role of practice placements in the career choices of student nurses, particularly during the final year of their programme. It shows that students are likely to apply for posts in the placement area they found to be most supportive and developmental

Causal network inference using biochemical kinetics

Motivation: Networks are widely used as structural summaries of biochemical systems. Statistical estimation of networks is usually based on linear or discrete models. However, the dynamics of biochemical systems are generally non-linear, suggesting that suitable non-linear formulations may offer gains with respect to causal network inference and aid in associated prediction problems. Results: We present a general framework for network inference and dynamical prediction using time course data that is rooted in nonlinear biochemical kinetics. This is achieved by considering a dynamical system based on a chemical reaction graph with associated kinetic parameters. Both the graph and kinetic parameters are treated as unknown; inference is carried out within a Bayesian framework. This allows prediction of dynamical behavior even when the underlying reaction graph itself is unknown or uncertain. Results, based on (i) data simulated from a mechanistic model of mitogen-activated protein kinase signaling and (ii) phosphoproteomic data from cancer cell lines, demonstrate that non-linear formulations can yield gains in causal network inference and permit dynamical prediction and uncertainty quantification in the challenging setting where the reaction graph is unknown. © The Author 2014. Published by Oxford University Press

The ErbB2ΔEx16 splice variant is a major oncogenic driver in breast cancer that promotes a pro-metastatic tumor microenvironment.

Amplification and overexpression of erbB2/neu proto-oncogene is observed in 20-30% human breast cancer and is inversely correlated with the survival of the patient. Despite this, somatic activating mutations within erbB2 in human breast cancers are rare. However, we have previously reported that a splice isoform of erbB2, containing an in-frame deletion of exon 16 (herein referred to as ErbB2ΔEx16), results in oncogenic activation of erbB2 because of constitutive dimerization of the ErbB2 receptor. Here, we demonstrate that the ErbB2ΔEx16 is a major oncogenic driver in breast cancer that constitutively signals from the cell surface. We further show that inducible expression of the ErbB2ΔEx16 variant in mammary gland of transgenic mice results in the rapid development of metastatic multifocal mammary tumors. Genetic and biochemical characterization of the ErbB2ΔEx16-derived mammary tumors exhibit several unique features that distinguish this model from the conventional ErbB2 ones expressing the erbB2 proto-oncogene in mammary epithelium. Unlike the wild-type ErbB2-derived tumors that express luminal keratins, ErbB2ΔEx16-derived tumors exhibit high degree of intratumoral heterogeneity co-expressing both basal and luminal keratins. Consistent with these distinct pathological features, the ErbB2ΔEx16 tumors exhibit distinct signaling and gene expression profiles that correlate with activation of number of key transcription factors implicated in breast cancer metastasis and cancer stem cell renewal

Recent amplification of an alpha satellite DNA in humans.

A repeat sequence 682 base pairs (bp) long produced by cleavage of human DNA with Xba I restriction enzyme is composed of four tandemly arranged subunits with lengths of 171, 170, 171, and 170 bp each. The sequence organization of the 682 bp Xba I repeat bears a striking resemblance to other complex satellite DNAs of primates, including the Eco RI human alpha satellite family which also occurs as a 170 bp repeat. The Eco RI tetramer and the 682 bp Xba I repeat show a sequence divergence of 21%. The 682 bp Xba I repeat sequence is restricted to humans and is only distantly related to the previously reported 340 bp Xba human repeated DNA sequence. These finding are consistent with the concept of occasional amplifications of members or groups of members of alpha satellite DNA during human evolution. Amplifications apparently occurred after humans, apes and gibbons diverged from Old World monkeys (Eco RI satellite), after humans and apes diverged from gibbons (340 bp Xba I satellite) and after humans diverged from the great apes (682 bp Xba I satellite)

Anticholinergic medication use and falls in postmenopausal women: Findings from the women's health initiative cohort study

Background: Results from studies assessing the association between anticholinergic use and falls are mixed, and prior studies are limited in their ability to control for important potential confounders. Thus, we sought to examine the association between anticholinergic medication use, including over-the-counter medications, and recurrent falls in community-dwelling older women. Methods: We analyzed data from a prospective cohort study of women aged 65 to 79 years from the Women's Health Initiative Observational Study and Clinical Trials. Women were recruited between 1993 and 1998, and analyses included 61,451 women with complete information. Medications with moderate or strong anticholinergic effects were ascertained directly from drug containers during face-to-face interviews. The main outcome measure was recurrent falls (≥2 falls in previous year), which was determined from self-report within 1.5 years subsequent to the medication assessment. Results: At baseline, 11.3 % were using an anticholinergic medication, of which antihistamines (commonly available over-the-counter) were the most common medication class (received by 45.2 % of individuals on anticholinergic medication). Using multivariable GEE models and controlling for potential confounders, the adjusted odds ratio for anticholinergic medication use was 1.51 (95 % CI, 1.43-1.60) for recurrent falls. Participants using multiple anticholinergic medications had a 100 % increase in likelihood of recurrent falls (adjusted odds ratio 2.00, 95 % CI 1.73-2.32). Results were robust to sensitivity analysis. Conclusions: Anticholinergic medication use was associated with increased risk for recurrent falls. Our findings reinforce judicious use of anticholinergic medications in older women. Public health efforts should emphasize educating older women regarding the risk of using over-the-counter anticholinergics, such as first-generation antihistamines

Inequivalent contact structures on Boothby-Wang 5-manifolds

We consider contact structures on simply-connected 5-manifolds which arise as circle bundles over simply-connected symplectic 4-manifolds and show that invariants from contact homology are related to the divisibility of the canonical class of the symplectic structure. As an application we find new examples of inequivalent contact structures in the same equivalence class of almost contact structures with non-zero first Chern class.Comment: 27 pages; to appear in Math. Zeitschrif