846 research outputs found
Salt Damage to Northern White-Cedar and White Spruce
Five-year-old transplants of northern white-cedar and white spruce were treated with tap water applied to the soil and with various concentrations of sodium chloride in distilled water, applied either to the soil or to the foliage. Observations were made on the gross morphological effects and anatomical effects of the treatments. Morphological damage included discoloration and loss of foliage. The most significant anatomical damage included fragmented cuticle, disrupted stomata, collapsed cell walls, disorganized or disintegrated protoplasts, coarsely granular cytoplasm, disintegrated chloroplasts, disintegrated nuclei and disorganized phloem. While there appeared to be no outstanding anatomical differences between the effects of soil versus foliar applications, both species did show somewhat less damage by soil-applied than by foliar-applied salt. It was not possible to conclusively assign the cause of morphological or anatomical damage to indirect effects, such as water deficiency or to ion toxicity of the salt. However, the results did suggest that northern white-cedar may be somewhat more salt-tolerant than white spruce
Cyclotron production and cyclometallation chemistry of 192Ir
Introduction
To explore new questions and techniques in nuclear medicine, new isotopes with novel chemical and nuclear properties must be developed. We are interested in the small cyclotron production of new radiometals for the development of new radiopharmaceuticals (RX). In an example of RX multifunctionality, Luminescence Cell Imaging (LCI) has been combined with radio-isotopes to allow compounds that can be imaged with both optical microscopy and nuclear techniques [1]. Within this field, iridium cy-clometalates have good potential with excellent photophysical properties [2]. As well, low specific activity iridium-192 has found use in brachy-therapy as a high-intensity beta emitter [3]. Despite this, iridium radioisotopes have yet to be applied to cyclometalation chemistry, or a radiochemical isolation method developed for carrier free production on a medical cyclotron. Our goal is to demonstrate the feasibility of the production and isolation of radio-iridium, and its application to cyclometalate chemistry as a potentially interesting tool for nuclear medicine research.
Materials and Methods
Following literature precedent [4], natural osmium was electroplated onto a silver disc from basic media containing osmium tetroxide and sulphamic acid. The thin deposits obtained (15â20 mg cmâ2) were weighed and characterized with scanning electron microscopy.
Targets were irradiated using the TRIUMF TR13 cyclotron, delivering 12.5 MeV protons to the target disc. Initial bombardments were per-formed at 5 ÎŒA; gamma spectra of the targets were collected 24 hours after end of bombardment.
The irradiated material was oxidized, dissolved from the target backing, and separated via anion exchange.
In parallel to the isotope production work, non-radioactive iridium was used to define a chemical procedure suitable for the synthesis of model iridium cyclometalate compounds given low concentrations of radioiridium. These experiments will be performed with radioactive iridium in the next step of the research project.
Results and Conclusion
Proton bombardment of natural osmium yielded a range of iridium isotopes, with characteristic spectral lines corresponding to 186-190Ir, and 192Ir; no other characteristic radiation was observed. The EOB activity of each isotope was then used in thin target calculations to approximate their (p,n) cross section. Preliminary cross section measurements of the 192Os(p,n)192Ir reaction (53 ± 13 mb @ 12.5 MeV) confirm published data (52.3 ± 5.7 mb @ 12.2 MeV) [6], and provide as-yet unpublished data on the lower mass number isotopes.
The progress of radioactive iridium through the radiochemical separation was tracked with a dose calibrator; the osmium complex formed was brightly coloured and could be seen retained on the column. The overall efficiency of the process is estimated at 80 %. Radioactive cyclometallation chemistry is currently under-way.
The production and isolation of a range of iridium isotopes in a chemically useful form was demonstrated, and is ready to be applied to a cyclometalate model compound. Future work will investigate the production of 192Ir from enriched 192Os
Cross-sectional evaluation of a longitudinal consultation skills course at a new UK medical school
Background: Good communication is a crucial element of good clinical care, and it is important to provide appropriate consultation skills teaching in undergraduate medical training to ensure that doctors have the necessary skills to communicate effectively with patients and other key stakeholders. This article aims to provide research evidence of the acceptability of a longitudinal consultation skills strand in an undergraduate medical course, as assessed by a cross-sectional evaluation of students' perceptions of their teaching and learning experiences. Methods: A structured questionnaire was used to collect student views. The questionnaire comprised two parts: 16 closed questions to evaluate content and process of teaching and 5 open-ended questions. Questionnaires were completed at the end of each consultation skills session across all year groups during the 2006-7 academic year (5 sessions in Year 1, 3 in Year 2, 3 in Year 3, 10 in Year 4 and 10 in Year 5). 2519 questionnaires were returned in total. Results: Students rated Tutor Facilitation most favourably, followed by Teaching, then Practice & Feedback, with suitability of the Rooms being most poorly rated. All years listed the following as important aspects they had learnt during the session: âą how to structure the consultation âą importance of patient-centredness âą aspects of professionalism (including recognising own limits, being prepared, generally acting professionally). All years also noted that the sessions had increased their confidence, particularly through practice. Conclusions: Our results suggest that a longitudinal and integrated approach to teaching consultation skills using a well structured model such as Calgary-Cambridge, facilitates and consolidates learning of desired process skills, increases student confidence, encourages integration of process and content, and reinforces appreciation of patient-centredness and professionalism
The Use of HCGâBased Combination Therapy for Recovery of Spermatogenesis after Testosterone Use
Introduction and AimAbout 3 million men take testosterone in the United States with many reproductiveâage men unaware of the negative impact of testosterone supplementation on fertility. Addressing this population, we provide an early report on the use of human chorionic gonadotropin (HCG)âbased combination therapy in the treatment of a series of men with likely testosteroneârelated azoospermia or severe oligospermia. MethodsWe retrospectively reviewed charts from two tertiary care infertility clinics to identify men presenting with azoospermia or severe oligospermia (<1 million sperm/mL) while taking exogenous testosterone. All were noted to have been placed on combination therapy, which included 3,000 units HCG subcutaneously every other day supplemented with clomiphene citrate, tamoxifen, anastrozole, or recombinant follicleâstimulating hormone (or combination) according to physician preference.Main Outcome MeasureClinical outcomes, including hormone values, semen analyses, and clinical pregnancies, were tracked. ResultsFortyânine men were included in this case series. Return of spermatogenesis for azoospermic men or improved counts for men with severe oligospermia was documented in 47 men (95.9%), with one additional man (2.1%) having a documented pregnancy without followâup semen analysis. The average time to return of spermatogenesis was 4.6 months with a mean first density of 22.6 million/mL. There was no significant difference in recovery by type of testosterone administered or supplemental therapy. No men stopped HCG or supplemental medications because of adverse events. ConclusionsWe here provide an early report of the feasibility of using combination therapy with HCG and supplemental medications in treating men with testosteroneârelated infertility. Future discussion and studies are needed to further characterize this therapeutic approach and document the presumed improved tolerability and speed of recovery compared with unaided withdrawal of exogenous testosterone. Wenker EP, Dupree JM, Langille GM, Kovac J, Ramasamy R, Lamb D, Mills JN, and Lipshultz LI. The use of HCGâbased combination therapy for recovery of spermatogenesis after testosterone use. J Sex Med 2015;12:1334â1337.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111925/1/jsm12890.pd
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An online study combining the constructs from the theory of planned behaviour and protection motivation theory in predicting intention to test for chlamydia in two testing contexts
Chlamydia is a common sexually-transmitted infection that has potentially serious consequences unless detected and treated early. The health service in the UK offers clinic-based testing for chlamydia but uptake is low. Identifying the predictors of testing behaviours may inform interventions to increase uptake. Self-tests for chlamydia may facilitate testing and treatment in people who avoid clinic-based testing. Self-testing and being tested by a health care professional (HCP) involve two contrasting contexts that may influence testing behaviour. However, little is known about how predictors of behaviour differ as a function of context. In this study, theoretical models of behaviour were used to assess factors that may predict intention to test in two different contexts: self-testing and being tested by a HCP. Individuals searching for, or reading about chlamydia testing online were recruited using Google Adwords. Participants completed an online questionnaire that addressed previous testing behaviour and measured constructs of the Theory of Planned Behaviour and Protection Motivation Theory, which propose a total of eight possible predictors of intention. The questionnaire was completed by 310 participants. Sufficient data for multiple regression were provided by 102 and 118 respondents for self-testing and testing by a HCP respectively. Intention to self-test was predicted by vulnerability and self-efficacy, with a trend-level effect for response efficacy. Intention to be tested by a HCP was predicted by vulnerability, attitude and subjective norm. Thus, intentions to carry out two testing behaviours with very similar goals can have different predictors depending on test context. We conclude that interventions to increase self-testing should be based on evidence specifically related to test context
G(alpha)11 signaling through ARF6 regulates F-actin mobilization and GLUT4 glucose transporter translocation to the plasma membrane
The action of insulin to recruit the intracellular GLUT4 glucose transporter to the plasma membrane of 3T3-L1 adipocytes is mimicked by endothelin 1, which signals through trimeric G(alpha)q or G(alpha)11 proteins. Here we report that murine G(alpha)11 is most abundant in fat and that expression of the constitutively active form of G(alpha)11 [G(alpha)11(Q209L)] in 3T3-L1 adipocytes causes recruitment of GLUT4 to the plasma membrane and stimulation of 2-deoxyglucose uptake. In contrast to the action of insulin on GLUT4, the effects of endothelin 1 and G(alpha)11 were not inhibited by the phosphatidylinositol 3-kinase inhibitor wortmannin at 100 nM. Signaling by insulin, endothelin 1, or G(alpha)11(Q209L) also mobilized cortical F-actin in cultured adipocytes. Importantly, GLUT4 translocation caused by all three agents was blocked upon disassembly of F-actin by latrunculin B, suggesting that the F-actin polymerization caused by these agents may be required for their effects on GLUT4. Remarkably, expression of a dominant inhibitory form of the actin-regulatory GTPase ARF6 [ARF6(T27N)] in cultured adipocytes selectively inhibited both F-actin formation and GLUT4 translocation in response to endothelin 1 but not insulin. These data indicate that ARF6 is a required downstream element in endothelin 1 signaling through G(alpha)11 to regulate cortical actin and GLUT4 translocation in cultured adipocytes, while insulin action involves different signaling pathways
Brazilian spring wheat germplasm as source of genetic variability.
As part of a Canada-Brazil germplasm exchange, 106 modern and ancient Brazilian spring wheat cultivars have been genotyped and phenotypically evaluated in Canada since 201
Comparative genomic analysis reveals habitat-specific genes and regulatory hubs within the genus Novosphingobium
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in mSystems 2 (2017): e00020-17, doi:10.1128/mSystems.00020-17.Species belonging to the genus Novosphingobium are found in many different habitats and have been identified as metabolically versatile. Through comparative genomic analysis, we identified habitat-specific genes and regulatory hubs that could determine habitat selection for Novosphingobium spp. Genomes from 27 Novosphingobium strains isolated from diverse habitats such as rhizosphere soil, plant surfaces, heavily contaminated soils, and marine and freshwater environments were analyzed. Genome size and coding potential were widely variable, differing significantly between habitats. Phylogenetic relationships between strains were less likely to describe functional genotype similarity than the habitat from which they were isolated. In this study, strains (19 out of 27) with a recorded habitat of isolation, and at least 3 representative strains per habitat, comprised four ecological groupsârhizosphere, contaminated soil, marine, and freshwater. Sulfur acquisition and metabolism were the only core genomic traits to differ significantly in proportion between these ecological groups; for example, alkane sulfonate (ssuABCD) assimilation was found exclusively in all of the rhizospheric isolates. When we examined osmolytic regulation in Novosphingobium spp. through ectoine biosynthesis, which was assumed to be marine habitat specific, we found that it was also present in isolates from contaminated soil, suggesting its relevance beyond the marine system. Novosphingobium strains were also found to harbor a wide variety of mono- and dioxygenases, responsible for the metabolism of several aromatic compounds, suggesting their potential to act as degraders of a variety of xenobiotic compounds. Protein-protein interaction analysis revealed ÎČ-barrel outer membrane proteins as habitat-specific hubs in each of the four habitatsâfreshwater (Saro_1868), marine water (PP1Y_AT17644), rhizosphere (PMI02_00367), and soil (V474_17210). These outer membrane proteins could play a key role in habitat demarcation and extend our understanding of the metabolic versatility of the Novosphingobium species.This work was supported by grants from the Department of Biotechnology (DBT),
R.K., S.H., K.P., A.B., and U.S. gratefully acknowledge the National Bureau of Agriculturally
Important Microorganisms (NBAIM), Science and Engineering Research Board
(SERB), N-PDF (PDF/2015/000062), (PDF/2015, 000319), University Grant Commission
(UGC) for the Dr. D. S. Kothari Postdoctoral Fellowship and UGC for providing fellowships,
respectively
The dental values scale: development and validation
Publisher's version/PDFThe purpose of this study was to produce a valid scale for use in measuring the values of dental students and practitionersâthe lack of which has impeded research on professionalism in dentistry. Following standard scale development procedures, we had focus groups of dental practitioners (N=23) develop a ninety-nine-item pool of value terms related to dentistry. Next, Canadian dentists (N=449) rated the relevance of each item through an online survey. They also rated the values in a generic values measure, Schwartzâs Values Scale. Exploratory and confirmatory factor analyses identified twenty-five items representing five values: Altruism, Personal Satisfaction, Conscientiousness, Quality of Life, and Professional Status. These values correlate with related dimensions from Schwartzâs measure; they also correspond to the values in the American Dental Education Associationâs statement on professionalism. We then administered the new Dental Values Scale to dental students (N=96) to determine the relationship between practitioner and student values. First-year students were higher in Conscientiousness, Altruism, and Personal Satisfaction than practitioners, but these values decreased over time to those held by the dentists. We discuss the implication of these results and the potential value of the new scale for dental education
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