1,619 research outputs found

    School-university partnerships: Lessons learned from 10 years of spectroscopy for teachers and post 16 students

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    Spectroscopy covers a wide range of analytical techniques, a small sub-set of which UK pre-university chemistry students are required to study. The expense of such equipment means that it is not available to the vast majority of schools whilst it is commonplace in university chemistry departments. This article discusses the evolution of the Bristol ChemLabS spectroscopy outreach activities. The advantages and disadvantages of this method of engagement for both the participants and the providers are discussed from 10 years of activity

    Phonological contrast and phonetic variation: The case of velars in Iwaidja

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    A field-based ultrasound and acoustic study of Iwaidja, an endangered Australian Aboriginal language, investigates the phonetic identity of nonnasal velar consonants in intervocalic position, where past work has proposed a [+continuant] vs. [−continuant] phonemic contrast. We analyze the putative contrast within a continuous phonetic space, defined by both acoustic and articulatory parameters, and find gradient variation: from more consonantal realizations, such as [ɰ], to more vocalic realizations, such as [a]. The distribution of realizations across lexical items and speakers does not support the proposed phonemic contrast. This case illustrates how lenition that is both phonetically gradient and variable across speakers and words can give the illusion of a contextually restricted phonemic contrast

    Fate and transport of volatile organic compounds in glacial till and groundwater at an industrial site in Northern Ireland

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    Volatile organic compound (VOC) contamination of subsurface geological material and groundwater was discovered on the Nortel Monkstown industrial site, Belfast, Northern Ireland. The objectives of this study were to (1) investigate the characteristics of the geological material and its influences on contaminated groundwater flow across the site using borehole logs and hydrological evaluations, and (2) identify the contaminants and examine their distribution in the subsurface geological material and groundwater using chemical analysis. This report focuses on the eastern car park (ECP) which was a former storage area associated with trichloroethene (TCE) degreasing operations. This is where the greatest amount of volatile organic compounds (VOCs), particularly TCE, were detected. The study site is on a complex deposit of clayey glacial till with discontinuous coarser grained lenses, mainly silts, sands and gravel, which occur at 0.45-7.82 m below ground level (bgl). The lenses overall form an elongated formation that acts as a small unconfined shallow aquifer. There is a continuous low permeable stiff clayey till layer beneath the lenses that performs as an aquitard to the groundwater. Highest concentrations of VOCs, mainly TCE, in the geological material and groundwater are in these coarser lenses at similar to 4.5-7 m bgl. Highest TCE measurements at 390,000 mu g L-1 for groundwater and at 39,000 mu g kg(-1) at 5.7 m for geological material were in borehole GA19 in the coarse lens zone. It is assumed that TCE gained entrance to the subsurface near this borehole where the clayey till was thin to absent above coarse lenses which provided little retardation to the vertical migration of this dense non-aqueous phase liquid (DNAPL) into the groundwater. However, TCE is present in low concentrations in the geological material overlying the coarse lens zone. Additionally, VOCs appear to be associated with poorly drained layers and in peat < 3.0 m bgl in the ECP. Some indication of natural attenuation as VOCs degradation products vinyl chloride (VC) and dichloromethane (DCM) also occur on the site

    Gac two-component system in Pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction

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    Pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. To investigate the regulatory mechanism of the expression of virulence, Gac two-Component system-defective mutants, Delta gacA and Delta gacS, and a double mutant, Delta gacA Delta gacS, were generated. These mutants produced smaller amounts of N-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algT gene required for exopolysaccharide production. The ability of the mutants to cause disease symptoms in their host tobacco plant was remarkably reduced, while they retained the ability to induce hypersensitive reaction (HR) in the nonhost plants. These results indicated that the Gac two-component system of P. syringae pv. tabaci 6605 is indispensable for virulence on the host plant, but not for HR induction in the nonhost plants.</p

    Do you think it's a disease? a survey of medical students

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    Background: The management of medical conditions is influenced by whether clinicians regard them as "disease" or "not a disease". The aim of the survey was to determine how medical students classify a range of conditions they might encounter in their professional lives and whether a different name for a condition would influence their decision in the categorisation of the condition as a 'disease' or 'not a disease'. Methods. We surveyed 3 concurrent years of medical students to classify 36 candidate conditions into "disease" and "non-disease". The conditions were given a 'medical' label and a (lay) label and positioned where possible in alternate columns of the survey. Results: The response rate was 96% (183 of 190 students attending a lecture): 80% of students concurred on 16 conditions as "disease" (eg diabetes, tuberculosis), and 4 as "non- disease" (eg baldness, menopause, fractured skull and heat stroke). The remaining 16 conditions (with 21-79% agreement) were more contentious (especially obesity, infertility, hay fever, alcoholism, and restless leg syndrome). Three pairs of conditions had both a more, and a less, medical label: the more medical labels (myalgic encephalomyelitis, hypertension, and erectile dysfunction) were more frequently classified as 'disease' than the less medical (chronic fatigue syndrome, high blood pressure, and impotence), respectively, significantly different for the first two pairs. Conclusions: Some conditions excluded from the classification of "disease" were unexpected (eg fractured skull and heat stroke). Students were mostly concordant on what conditions should be classified as "disease". They were more likely to classify synonyms as 'disease' if the label was medical. The findings indicate there is still a problem 30 years on in the concept of 'what is a disease'. Our findings suggest that we should be addressing such concepts to medical students

    Transcription profiling reveals potential mechanisms of dysbiosis in the oral microbiome of rhesus macaques with chronic untreated SIV infection.

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    A majority of individuals infected with human immunodeficiency virus (HIV) have inadequate access to antiretroviral therapy and ultimately develop debilitating oral infections that often correlate with disease progression. Due to the impracticalities of conducting host-microbe systems-based studies in HIV infected patients, we have evaluated the potential of simian immunodeficiency virus (SIV) infected rhesus macaques to serve as a non-human primate model for oral manifestations of HIV disease. We present the first description of the rhesus macaque oral microbiota and show that a mixture of human commensal bacteria and "macaque versions" of human commensals colonize the tongue dorsum and dental plaque. Our findings indicate that SIV infection results in chronic activation of antiviral and inflammatory responses in the tongue mucosa that may collectively lead to repression of epithelial development and impact the microbiome. In addition, we show that dysbiosis of the lingual microbiome in SIV infection is characterized by outgrowth of Gemella morbillorum that may result from impaired macrophage function. Finally, we provide evidence that the increased capacity of opportunistic pathogens (e.g. E. coli) to colonize the microbiome is associated with reduced production of antimicrobial peptides

    Morpholino Gene Knockdown in Adult Fundulus heteroclitus: Role of SGK1 in Seawater Acclimation

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    The Atlantic killifish (Fundulus heteroclitus) is an environmental sentinel organism used extensively for studies on environmental toxicants and salt (NaCl) homeostasis. Previous research in our laboratory has shown that rapid acclimation of killifish to seawater is mediated by trafficking of CFTR chloride channels from intracellular vesicles to the plasma membrane in the opercular membrane within the first hour in seawater, which enhances chloride secretion into seawater, thereby contributing to salt homeostasis. Acute transition to seawater is also marked by an increase in both mRNA and protein levels of serum glucocorticoid kinase 1 (SGK1) within 15 minutes of transfer. Although the rise in SGK1 in gill and its functional analog, the opercular membrane, after seawater transfer precedes the increase in membrane CFTR, a direct role of SGK1 in elevating membrane CFTR has not been established in vivo. To test the hypothesis that SGK1 mediates the increase in plasma membrane CFTR we designed two functionally different vivo-morpholinos to knock down SGK1 in gill, and developed and validated a vivo-morpholino knock down technique for adult killifish. Injection (intraperitoneal, IP) of the splice blocking SGK1 vivo-morpholino reduced SGK1 mRNA in the gill after transition from fresh to seawater by 66%. The IP injection of the translational blocking and splice blocking vivo-morpholinos reduced gill SGK1 protein abundance in fish transferred from fresh to seawater by 64% and 53%, respectively. Moreover, knock down of SGK1 completely eliminated the seawater induced rise in plasma membrane CFTR, demonstrating that the increase in SGK1 protein is required for the trafficking of CFTR from intracellular vesicles in mitochondrion rich cells to the plasma membrane in the gill during acclimation to seawater. This is the first report of the use of vivo-morpholinos in adult killifish and demonstrates that vivo-morpholinos are a valuable genetic tool for this environmentally relevant model organism

    Pregnancy and neonatal outcomes in COVID-19: study protocol for a global registry of women with suspected or confirmed SARS-CoV-2 infection in pregnancy and their neonates, understanding natural history to guide treatment and prevention

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    ntroduction Previous novel COVID-19 pandemics, SARS and middle east respiratory syndrome observed an association of infection in pregnancy with preterm delivery, stillbirth and increased maternal mortality. COVID-19, caused by SARS-CoV-2 infection, is the largest pandemic in living memory. Rapid accrual of robust case data on women in pregnancy and their babies affected by suspected COVID-19 or confirmed SARS-CoV-2 infection will inform clinical management and preventative strategies in the current pandemic and future outbreaks. Methods and analysis The pregnancy and neonatal outcomes in COVID-19 (PAN-COVID) registry are an observational study collecting focused data on outcomes of pregnant mothers who have had suspected COVID-19 in pregnancy or confirmed SARS-CoV-2 infection and their neonates via a web-portal. Among the women recruited to the PAN-COVID registry, the study will evaluate the incidence of: (1) miscarriage and pregnancy loss, (2) fetal growth restriction and stillbirth, (3) preterm delivery, (4) vertical transmission (suspected or confirmed) and early onset neonatal SARS-CoV-2 infection. Data will be centre based and collected on individual women and their babies. Verbal consent will be obtained, to reduce face-to-face contact in the pandemic while allowing identifiable data collection for linkage. Statistical analysis of the data will be carried out on a pseudonymised data set by the study statistician. Regular reports will be distributed to collaborators on the study research questions. Ethics and dissemination This study has received research ethics approval in the UK. For international centres, evidence of appropriate local approval will be required to participate, prior to entry of data to the database. The reports will be published regularly. The outputs of the study will be regularly disseminated to participants and collaborators on the study website (https://pan-covid.org) and social media channels as well as dissemination to scientific meetings and journals

    Relatively higher norms of blood flow velocity of major intracranial arteries in North-West Iran

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    <p>Abstract</p> <p>Background</p> <p>Transcranial Doppler (TCD) is a noninvasive, less expensive and harmless hemodynamic study of main intracranial arteries. The aim of this study was to assess normal population values of cerebral blood flow velocity and its variation over age and gender in a given population.</p> <p>Findings</p> <p>Eighty healthy volunteers including 40 people with an age range of 25-40 years (group1) and 40 persons with an age range of 41-55 years (group2) were studied. In each group 20 males and 20 females were enrolled. Peak systolic, end diastolic and mean velocities of nine main intracranial arteries were determined using TCD. Mean age of the studied volunteers was 31.6 ± 4.50 years in group one and 47.2 ± 4.3 years in group two. Mean age among males was 40 years and among females it was 39. Mean blood flow velocity in middle, anterior and posterior cerebral arteries, vertebral and basilar arteries was 60 ± 8, 52 ± 9, 42 ± 6, 39 ± 8 and 48 ± 8 cm/sec respectively. Cerebral blood flow velocities among females were relatively higher than males. Cerebral blood flow velocity of left side was relatively higher than right side.</p> <p>Conclusion</p> <p>Compared to previous studies, cerebral blood flow velocity in this population was relatively higher.</p

    Abundance estimation of Ixodes ticks (Acari: Ixodidae) on roe deer (Capreolus capreolus)

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    Despite the importance of roe deer as a host for Ixodes ticks in central Europe, estimates of total tick burden on roe deer are not available to date. We aimed at providing (1) estimates of life stage and sex specific (larvae, nymphs, males and females, hereafter referred to as tick life stages) total Ixodes burden and (2) equations which can be used to predict the total life stage burden by counting the life stage on a selected body area. Within a period of 1½ years, we conducted whole body counts of ticks from 80 hunter-killed roe deer originating from a beech dominated forest area in central Germany. Averaged over the entire study period (winter 2007–summer 2009), the mean tick burden per roe deer was 64.5 (SE ± 10.6). Nymphs were the most numerous tick life stage per roe deer (23.9 ± 3.2), followed by females (21.4 ± 3.5), larvae (10.8 ± 4.2) and males (8.4 ± 1.5). The individual tick burden was highly aggregated (k = 0.46); levels of aggregation were highest in larvae (k = 0.08), followed by males (k = 0.40), females (k = 0.49) and nymphs (k = 0.71). To predict total life stage specific burdens based on counts on selected body parts, we provide linear equations. For estimating larvae abundance on the entire roe deer, counts can be restricted to the front legs. Tick counts restricted to the head are sufficient to estimate total nymph burden and counts on the neck are appropriate for estimating adult ticks (females and males). In order to estimate the combined tick burden, tick counts on the head can be used for extrapolation. The presented linear models are highly significant and explain 84.1, 77.3, 90.5, 91.3, and 65.3% (adjusted R2) of the observed variance, respectively. Thus, these models offer a robust basis for rapid tick abundance assessment. This can be useful for studies aiming at estimating effects of abiotic and biotic factors on tick abundance, modelling tick population dynamics, modelling tick-borne pathogen transmission dynamics or assessing the efficacy of acaricides
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