854 research outputs found
A systematic review of robot-assisted cholecystectomy to examine the quality of reporting in relation to the IDEAL recommendations:systematic review
Is dissection the only way to learn anatomy? Thoughts from students at a non-dissecting based medical school.
Anatomical teaching has been centred around dissection for centuries. Generations of doctors have been initiated into the medical profession by cutting into their first cadavers. With the number of donor cadavers available decreasing and medical student numbers increasing, the emphasis placed on dissection has changed dramatically over the past 15 years. However, a solid appreciation of human anatomy is still a necessary part of understanding pathology and treatments. Therefore in light of these changes we ask, is dissection the only option? Or are there other options which students can undertake to develop anatomical knowledge?This article is freely available via Open Access. Click on the 'Additional Link' above to access the full-text from the publisher's site.Published (Open Access
A JWST/MIRI and NIRCam Analysis of the Young Stellar Object Population in the Spitzer I region of NGC 6822
We present an imaging survey of the Spitzer~I star-forming region in NGC 6822
conducted with the NIRCam and MIRI instruments onboard JWST. Located at a
distance of 490 kpc, NGC 6822 is the nearest non-interacting low-metallicity
(0.2 ) dwarf galaxy. It hosts some of the brightest known HII
regions in the local universe, including recently discovered sites of
highly-embedded active star formation. Of these, Spitzer I is the youngest and
most active, and houses 90 color-selected candidate young stellar objects
(YSOs) identified from Spitzer Space Telescope observations. We revisit the YSO
population of Spitzer~I with these new JWST observations. By analyzing
color-magnitude diagrams (CMDs) constructed with NIRCam and MIRI data, we
establish color selection criteria and construct spectral energy distributions
(SEDs) to identify candidate YSOs and characterize the full population of young
stars, from the most embedded phase to the more evolved stages. In this way, we
have identified 129 YSOs in Spitzer I. Comparing to previous Spitzer studies of
the NGC 6822 YSO population, we find that the YSOs we identify are fainter and
less massive, indicating that the improved resolution of JWST allows us to
resolve previously blended sources into individual stars.Comment: 17 pages, 9 figures, 2 tables, to be submitted to ApJ, comments
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Risk factors associated with bloodstream infections among critically ill patients with COVID-19
JWST MIRI and NIRCam Unveil Previously Unseen Infrared Stellar Populations in NGC 6822
NGC 6822 is a nearby (\sim490 kpc) non-interacting low-metallicity (0.2
Z_\odot) dwarf galaxy which hosts several prominent Hii regions, including
sites of highly embedded active star formation. In this work, we present an
imaging survey of NGC 6822 conducted with the NIRCam and MIRI instruments
onboard JWST. We provide a description of the data reduction, source
extraction, and stellar population identifications from combined near- and
mid-infrared (IR) photometry. Our NIRCam observations reach seven magnitudes
deeper than previous JHKs surveys of this galaxy, which were sensitive to just
below the tip of the red giant branch (TRGB). These JWST observations thus
reveal for the first time in the near-IR the red clump stellar population and
extend nearly three magnitudes deeper. In the mid-IR, we observe roughly two
magnitudes below the TRGB with the MIRI F770W and F1000W filters. With these
improvements in sensitivity, we produce a catalogue of \sim900,000 point
sources over an area of \sim 6.0 x 4.3 arcmin2. We present several NIRCam and
MIRI colour-magnitude diagrams and discuss which colour combinations provide
useful separations of various stellar populations to aid in future JWST
observation planning. Finally, we find populations of carbon- and oxygen-rich
asymptotic giant branch stars which will assist in improving our understanding
of dust production in low-metallicity, early Universe analogue galaxies
Diversity of a cytokinin dehydrogenase gene in wild and cultivated barley
The cytokinin dehydrogenase gene HvCKX2.1 is the regulatory target for the most abundant heterochromatic small RNAs in drought-stressed barley caryopses. We investigated the diversity of HvCKX2.1 in 228 barley landraces and 216 wild accessions and identified 14 haplotypes, five of these with ten or more members, coding for four different protein variants. The third largest haplotype was abundant in wild accessions (51 members), but absent from the landrace collection. Protein structure predictions indicated that the amino acid substitution specific to haplotype 3 could result in a change in the functional properties of the HvCKX2.1 protein. Haplotypes 1–3 have overlapping geographical distributions in the wild population, but the average rainfall amounts at the collection sites for haplotype 3 plants are significantly higher during November to February compared to the equivalent data for plants of haplotypes 1 and 2. We argue that the likelihood that haplotype 3 plants were excluded from landraces by sampling bias that occurred when the first wild barley plants were taken into cultivation is low, and that it is reasonable to suggest that plants with haplotype 3 are absent from the crop because these plants were less suited to the artificial conditions associated with cultivation. Although the cytokinin signalling pathway influences many aspects of plant development, the identified role of HvCKX2.1 in the drought response raises the possibility that the particular aspect of cultivation that mitigated against haplotype 3 relates in some way to water utilization. Our results therefore highlight the possibility that water utilization properties should be looked on as a possible component of the suite of physiological adaptations accompanying the domestication and subsequent evolution of cultivated barley
General practitioner workforce planning: assessment of four policy directions
<p>Abstract</p> <p>Background</p> <p>Estimating the supply of GPs into the future is important in forecasting shortages. The lengthy training process for medicine means that adjusting supply to meet demand in a timely fashion is problematic. This study uses Ireland as a case study to determine the future demand and supply of GPs and to assess the potential impact of several possible interventions to address future shortages.</p> <p>Methods</p> <p>Demand was estimated by applying GP visit rates by age and sex to national population projections. Supply was modelled using a range of parameters derived from two national surveys of GPs. A stochastic modelling approach was adopted to determine the probable future supply of GPs. Four policy interventions were tested: increasing vocational training places; recruiting GPs from abroad; incentivising later retirement; increasing nurse substitution to enable practice nurses to deliver more services.</p> <p>Results</p> <p>Relative to most other European countries, Ireland has few GPs per capita. Ireland has an ageing population and demand is estimated to increase by 19% by 2021. Without intervention, the supply of GPs will be 5.7% less than required in 2021. Increasing training places will enable supply to meet demand but only after 2019. Recruiting GPs from overseas will enable supply to meet demand continuously if the number recruited is approximately 0.8 per cent of the current workforce per annum. Later retirement has only a short-term impact. Nurse substitution can enable supply to meet demand but only if large numbers of practice nurses are recruited and allowed to deliver a wide range of GP services.</p> <p>Conclusions</p> <p>A significant shortfall in GP supply is predicted for Ireland unless recruitment is increased. The shortfall will have numerous knock-on effects including price increases, longer waiting lists and an increased burden on hospitals. Increasing training places will not provide an adequate response to future shortages. Foreign recruitment has ethical considerations but may provide a rapid and effective response. Increased nurse substitution appears to offer the best long-term prospects of addressing GP shortages and presents the opportunity to reshape general practice to meet the demands of the future.</p
Gene expression analysis in human osteoblasts exposed to dexamethasone identifies altered developmental pathways as putative drivers of osteoporosis
BACKGROUND: Osteoporosis, a disease of decreased bone mineral density represents a significant and growing burden in the western world. Aging population structure and therapeutic use of glucocorticoids have contributed in no small way to the increase in the incidence of this disease. Despite substantial investigative efforts over the last number of years the exact molecular mechanism underpinning the initiation and progression of osteoporosis remain to be elucidated. This has meant that no significant advances in therapeutic strategies have emerged, with joint replacement surgery being the mainstay of treatment. METHODS: In this study we have used an integrated genomics profiling and computational biology based strategy to identify the key osteoblast genes and gene clusters whose expression is altered in response to dexamethasone exposure. Primary human osteoblasts were exposed to dexamethasone in vitro and microarray based transcriptome profiling completed. RESULTS: These studies identified approximately 500 osteoblast genes whose expression was altered. Functional characterization of the transcriptome identified developmental networks as being reactivated with 106 development associated genes found to be differentially regulated. Pathway reconstruction revealed coordinate alteration of members of the WNT signaling pathway, including frizzled-2, frizzled-7, DKK1 and WNT5B, whose differential expression in this setting was confirmed by real time PCR. CONCLUSION: The WNT pathway is a key regulator of skeletogenesis as well as differentiation of bone cells. Reactivation of this pathway may lead to altered osteoblast activity resulting in decreased bone mineral density, the pathological hallmark of osteoporosis. The data herein lend weight to the hypothesis that alterations in developmental pathways drive the initiation and progression of osteoporosis
SmCL3, a Gastrodermal Cysteine Protease of the Human Blood Fluke Schistosoma mansoni
Parasitic infection caused by blood flukes of the genus Schistosoma is a major global health problem. More than 200 million people are infected. Identifying and characterizing the constituent enzymes of the parasite's biochemical pathways should reveal opportunities for developing new therapies (i.e., vaccines, drugs). Schistosomes feed on host blood, and a number of proteolytic enzymes (proteases) contribute to this process. We have identified and characterized a new protease, SmCL3 (for Schistosoma mansoni cathepsin L3), that is found within the gut tissue of the parasite. We have employed various biochemical and molecular biological methods and sequence similarity analyses to characterize SmCL3 and obtain insights into its possible functions in the parasite, as well as its evolutionary position among cathepsin L proteases in general. SmCL3 hydrolyzes major host blood proteins (serum albumin and hemoglobin) and is expressed in parasite life stages infecting the mammalian host. Enzyme substrate specificity detected by positional scanning-synthetic combinatorial library was confirmed by molecular modeling. A sequence analysis placed SmCL3 to the cluster of other cathepsins L in accordance with previous phylogenetic analyses
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