Nano-cathodoluminescence reveals the effect of electron damage on the optical properties of nitride optoelectronics and the damage threshold

Nano-cathodoluminescence (Nano-CL) reveals optical emission from individual InGaN quantum wells for applications in optoelectronic devices. We show the luminescent intensity decays over time with exposure to the electron beam for energies between 80 and 200 keV. Measurements of the CL intensity over time show an exponential decline in intensity, which we propose is due to the formation of nitrogen Frenkel defects. The measured CL damage decreases with reductions in the electron accelerating voltage and we suggest that the electron induced structural damage may be suppressed below the proposed damage threshold. The electron beam induced damage leads to a non-radiative region that extends over the measured minority carrier diffusion length. Nano-CL may thus serve as a powerful technique to study III-nitride optoelectronics.This work was carried out with the support of the United Kingdom Engineering and Physical Sciences Research Council under Grant Nos. EP/NO17927/1 and EP/J003603/1. R. Oliver acknowledges funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement number 279361 (MACONS) and the from the Royal Academy of Engineers/Leverhulme Trust senior research fellowship

Mammographic density does not correlate with Ki-67 expression or cytomorphology in benign breast cells obtained by random periareolar fine needle aspiration from women at high risk for breast cancer

BACKGROUND:Ki-67 expression is a possible risk biomarker and is currently being used as a response biomarker in chemoprevention trials. Mammographic breast density is a risk biomarker and is also being used as a response biomarker. We previously showed that Ki-67 expression is higher in specimens of benign breast cells exhibiting cytologic atypia that are obtained by random periareolar fine needle aspiration (RPFNA). It is not known whether there is a correlation between mammographic density and Ki-67 expression in benign breast ductal cells obtained by RPFNA.METHODS:Included in the study were 344 women at high risk for developing breast cancer (based on personal or family history), seen at The University of Kansas Medical Center high-risk breast clinic, who underwent RPFNA with cytomorphology and Ki-67 assessment plus a mammogram. Mammographic breast density was assessed using the Cumulus program. Categorical variables were analyzed by ?2 test, and continuous variables were analyzed by nonparametric test and linear regression.RESULTS:Forty-seven per cent of women were premenopausal and 53% were postmenopausal. The median age was 48 years, median 5-year Gail Risk was 2.2%, and median Ki-67 was 1.9%. The median mammographic breast density was 37%. Ki-67 expression increased with cytologic abnormality (atypia versus no atypia; P = 0.001) and younger age (=50 years versus >50 years; P = 0.001). Mammographic density was higher in premenopausal women (P = 0.001), those with lower body mass index (P < 0.001), and those with lower 5-year Gail risk (P = 0.001). Mammographic density exhibited no correlation with Ki-67 expression or cytomorphology.CONCLUSION:Given the lack of correlation of mammographic breast density with either cytomorphology or Ki-67 expression in RPFNA specimens, mammographic density and Ki-67 expression should be considered as potentially complementary response biomarkers in breast cancer chemoprevention trials

Nemo: a computational tool for analyzing nematode locomotion

The nematode Caenorhabditis elegans responds to an impressive range of chemical, mechanical and thermal stimuli and is extensively used to investigate the molecular mechanisms that mediate chemosensation, mechanotransduction and thermosensation. The main behavioral output of these responses is manifested as alterations in animal locomotion. Monitoring and examination of such alterations requires tools to capture and quantify features of nematode movement. In this paper, we introduce Nemo (nematode movement), a computationally efficient and robust two-dimensional object tracking algorithm for automated detection and analysis of C. elegans locomotion. This algorithm enables precise measurement and feature extraction of nematode movement components. In addition, we develop a Graphical User Interface designed to facilitate processing and interpretation of movement data. While, in this study, we focus on the simple sinusoidal locomotion of C. elegans, our approach can be readily adapted to handle complicated locomotory behaviour patterns by including additional movement characteristics and parameters subject to quantification. Our software tool offers the capacity to extract, analyze and measure nematode locomotion features by processing simple video files. By allowing precise and quantitative assessment of behavioral traits, this tool will assist the genetic dissection and elucidation of the molecular mechanisms underlying specific behavioral responses.Comment: 12 pages, 2 figures. accepted by BMC Neuroscience 2007, 8:8

The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots

During plant immunity, surface-localized pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs). The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs) EFR and XA21 from Arabidopsis thaliana (Arabidopsis) and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto) DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots

The mechanical stability of the world’s tallest broadleaf trees

© 2020 The Authors. Biotropica published by Wiley Periodicals LLC on behalf of Association for Tropical Biology and Conservation The factors that limit the maximum height of trees, whether ecophysiological or mechanical, are the subject of longstanding debate. Here, we examine the role of mechanical stability in limiting tree height and focus on trees from the tallest tropical forests on Earth, in Sabah, Malaysian Borneo, including the recently discovered tallest tropical tree, a 100.8 m Shorea faguetiana named Menara. We use terrestrial laser scans, in situ strain gauge data and finite element simulations, to map the architecture of tall tropical trees and monitor their response to wind loading. We demonstrate that a tree's risk of breaking due to gravity or self-weight decreases with tree height and is much more strongly affected by tree architecture than by material properties. In contrast, wind damage risk increases with tree height despite the larger diameters of tall trees, resulting in a U-shaped curve of mechanical risk with tree height. Our results suggest that the relative rarity of extreme wind speeds in north Borneo may be the reason it is home to the tallest trees in the tropics. Abstract in MALAY is available with online material

How to increase the potential policy impact of environmental science research

This article highlights eight common issues that limit the policy impact of environmental science research. The article also discusses what environmental scientists can do to resolve these issues, including (1) optimising the directness of their study so that it examines similar processes/populations/environments/ecosystems to that of policy interest; (2) using the most powerful study design possible, to increase confidence in the identified causal mechanisms; (3) selecting a sufficient sample size, to reduce the chance of false positives/negatives and increase policy-makers’ confidence in extrapolation of the findings; (4) minimizing the risk of bias through randomization of study units to treatment and control groups (reducing the risk of selection bias), blinding of study units and investigators (reducing the risk of performance and detection bias), following-up study units from enrolment to study completion (reducing the risk of attrition bias) and prospectively registering the study on a publically-available platform (reducing the risk of reporting and publication bias); (5) proving that statistical analyses meet test assumptions by reporting the results of statistical assumption checks, ideally publishing full datasets online in an open-access format; (6) publishing the research whether statistically significant or not, policy-makers are just as interested in the negative or insignificant results as they are in the positive results; (7) making the study easy to find and use, the title and abstract of an article are of high importance in determining whether articles are examined in detail or not and used to inform policy; (8) contributing towards systematic reviews on environmental topics, to provide policy-makers with comprehensive, reproducible and updateable syntheses of all the evidence on a given topic.</p

Hypertonic saline reduces inflammation and enhances the resolution of oleic acid induced acute lung injury

<p>Abstract</p> <p>Background</p> <p>Hypertonic saline (HTS) reduces the severity of lung injury in ischemia-reperfusion, endotoxin-induced and ventilation-induced lung injury. However, the potential for HTS to modulate the resolution of lung injury is not known. We investigated the potential for hypertonic saline to modulate the evolution and resolution of oleic acid induced lung injury.</p> <p>Methods</p> <p>Adult male Sprague Dawley rats were used in all experiments. <b><it>Series 1 </it></b>examined the potential for HTS to reduce the severity of evolving oleic acid (OA) induced acute lung injury. Following intravenous OA administration, animals were randomized to receive isotonic (Control, n = 12) or hypertonic saline (HTS, n = 12), and the extent of lung injury assessed after 6 hours. <b><it>Series 2 </it></b>examined the potential for HTS to enhance the resolution of oleic acid (OA) induced acute lung injury. Following intravenous OA administration, animals were randomized to receive isotonic (Control, n = 6) or hypertonic saline (HTS, n = 6), and the extent of lung injury assessed after 6 hours.</p> <p>Results</p> <p>In <b><it>Series I</it></b>, HTS significantly reduced bronchoalveolar lavage (BAL) neutrophil count compared to Control [61.5 ± 9.08 versus 102.6 ± 11.89 × 10³ cells.ml^-1]. However, there were no between group differences with regard to: A-a O2 gradient [11.9 ± 0.5 vs. 12.0 ± 0.5 KPa]; arterial PO2; static lung compliance, or histologic injury. In contrast, in <b><it>Series 2</it></b>, hypertonic saline significantly reduced histologic injury and reduced BAL neutrophil count [24.5 ± 5.9 versus 46.8 ± 4.4 × 10³ cells.ml^-1], and interleukin-6 levels [681.9 ± 190.4 versus 1365.7 ± 246.8 pg.ml^-1].</p> <p>Conclusion</p> <p>These findings demonstrate, for the first time, the potential for HTS to reduce pulmonary inflammation and enhance the resolution of oleic acid induced lung injury.</p

Choice of geographic unit influences socioeconomic inequalities in breast cancer survival

Socioeconomic differences in age-standardised crude survival for women diagnosed with breast cancer during 1991–1999 in England were influenced by the population of the geographic area used to assign the deprivation index, but not by the choice of index

Experimental manipulation of radiographic density in mouse mammary gland

INTRODUCTION: Extensive mammographic density in women is associated with increased risk for breast cancer. Mouse models provide a powerful approach to the study of human diseases, but there is currently no model that is suited to the study of mammographic density. METHODS: We performed individual manipulations of the stromal, epithelial and matrix components of the mouse mammary gland and examined the alterations using in vivo and ex vivo radiology, whole mount staining and histology. RESULTS: Areas of density were generated that resembled densities in mammographic images of the human breast, and the nature of the imposed changes was confirmed at the cellular level. Furthermore, two genetic models, one deficient in epithelial structure (Pten conditional tissue specific knockout) and one with hyperplastic epithelium and mammary tumors (MMTV-PyMT), were used to examine radiographic density. CONCLUSION: Our data show the feasibility of altering and imaging mouse mammary gland radiographic density by experimental and genetic means, providing the first step toward modelling the biological processes that are responsible for mammographic density in the mouse

General practitioners' use and experiences of palliative care services: a survey in south east England

<p>Abstract</p> <p>Background</p> <p>The role of the General Practitioner (GP) is central to community palliative care. Good liaison between the different professionals involved in a patient's care is extremely important in palliative care patients. In cases where GPs have previously been dissatisfied with palliative services, this may be seen as a barrier to referral when caring for other patients. The aim of this survey is to investigate the use and previous experiences of GPs of two palliative care services, with particular emphasis on barriers to referral and to explore issues surrounding the GP's role in caring for palliative patients.</p> <p>Methods</p> <p>Design: Descriptive postal survey of use and experience of palliative care services with particular emphasis on barriers to referral. Setting: One Primary Care Trust (PCT), south London, England, population 298,500. Subjects: 180 GPs in the PCT, which is served by two hospice services (A&B).</p> <p>Results</p> <p>An overall questionnaire response rate of 77% (138) was obtained, with 69% (124) used in analysis. Over 90% of GPs were satisfied with the palliative care services over the preceding two years. Two areas of possible improvement emerged; communication and prescribing practices. GPs identified some patients that they had not referred, most commonly when patients or carers were reluctant to accept help, or when other support was deemed sufficient. Over half of the GPs felt there were areas where improvement could be made; with clarification of the rules and responsibilities of the multi disciplinary team being the most common. The majority of GPs were working, and want to work with, the specialist services as part of an extended team. However, a greater number of GPs want to hand over care to the specialist services than are currently doing so.</p> <p>Conclusion</p> <p>A large number of GPs were happy with the service provision of the palliative care services in this area. They suggested that 3 out of 4 terminally ill patients needed specialist input. Views of services were largely positive, and reasons for non referral were unrelated to previous experience of the specialist services.</p