427 research outputs found

    Multiepoch Radial Velocity Observations of L Dwarfs

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    We report on the development of a technique for precise radial-velocity measurements of cool stars and brown dwarfs in the near infrared. Our technique is analogous to the Iodine (I2) absorption cell method that has proven so successful in the optical regime. We rely on telluric CH4 absorption features to serve as a wavelength reference, relative to which we measure Doppler shifts of the CO and H2O features in the spectra of our targets. We apply this technique to high-resolution (R~50,000) spectra near 2.3 micron of nine L dwarfs taken with the Phoenix instrument on Gemini-South and demonstrate a typical precision of 300 m/s. We conduct simulations to estimate our expected precision and show our performance is currently limited by the signal-to-noise of our data. We present estimates of the rotational velocities and systemic velocities of our targets. With our current data, we are sensitive to companions with M sin i > 2MJ in orbits with periods less than three days. We identify no companions in our current data set. Future observations with improved signal-to-noise should result in radial-velocity precision of 100 m/s for L dwarfs.Comment: Accepted for publication in ApJ, 24 pages, 7 figure

    Complete Genome Sequences of Mycobacterium smegmatis Phages Chewbacca, Reptar3000, and Riparian, Isolated in Las Vegas, Nevada

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    Here, we present the complete genome sequences of Mycobacterium smegmatis phages Chewbacca, Reptar3000, and Riparian, isolated from soil in Las Vegas, NV. The phages were isolated and annotated by undergraduate students enrolled in the Phage Discovery course offered by the School of Life Sciences at the University of Nevada, Las Vega

    One Year Clinical Outcomes of Renal Artery Stenting: The Results of ODORI Registry

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    The safety, efficacy and long term clinical benefits of renal artery revascularization by stenting are still a matter of debate. The aim of our study was to define the safety and efficacy of renal artery stenting with the Tsunami peripheral stent (Terumo Corporation, Tokyo, Japan). The ODORI was a prospective, multicentre registry which enrolled 251 consecutive patients, (276 renal arteries) in 36 centres across Europe. The primary endpoint was acute procedural success defined as <30% residual stenosis after stent placement. Secondary endpoints included major adverse events, blood pressure control, serum creatinine level, and target lesion revascularization (TLR) at 6 and 12 months. Patients were 70 ± 10 years old, 59% were male, 33% had diabetes, and 96% hypertension. The main indications for renal stent implantation were hypertension in 83% and renal salvage in 39%. Direct stent implantation was performed in 76% of the cases. Acute success rate was 100% with residual stenosis of 2.5 ± 5.4%. Systolic/diastolic blood pressure decreased from a mean of 171/89 at baseline to 142/78 mmHg at 6 months (p < 0.0001 vs. baseline), and 141/80 mmHg at 12 months (p < 0.0001 vs. baseline). Mean serum creatinine concentration did not change significantly in the total population. However, there was significant improvement in the highest tercile (from 283 μmol/l at baseline to 205 and 209 μmol/l at 6 and 12 months respectively). At 12-months, rates of restenosis and TLR were 6.6 and 0.8% respectively. The 12 month cumulative rate of all major clinical adverse events was 6.4% while the rate of device or procedure related events was 2.4%. In hypertensive patients with atherosclerotic renal artery stenosis Tsunami peripheral balloon-expandable stent provides a safe revascularization strategy, with a potential beneficial impact on hypertension control and renal function in the highest risk patients

    Relationship of morpho-sedimentological variations to the fate of Hg- and Zn-polluted sediments in the contaminated site of Porto Marghera, Lagoon of Venice, Italy.

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    New data collected from twenty-six sites during 2008 in the contaminated Site of National Interest (SIN) of Porto Mar- ghera within the Lagoon of Venice (Italy), which has been affected by the presence of an industrial zone for the last 80 years, were compared with data from a campaign performed in the same site 30 years before (1976-1978). The SIN was found to be heavily polluted in the earlier study, and several tons of Hg and Zn are still stored in soils and industrial channel sediments, potentially affecting the lagoon part of the SIN. Bathymetric variations, grain-size, Hg and Zn con- tent in sediments were analysed. The severe contamination of the late 1970s (Hg 1.7 µg/g; Zn 754 µg/g) had fallen by the late 2000s (Hg 0.9 µg/g; Zn 225 µg/g). The fall in Hg and Zn contamination over the 30-year period was mainly linked to the patterns of geomorphological change inside the SIN that affected two distinct sub-areas: 1) a stable-depo- sitional (SD) area in the Northern part, which exerted a “dilution” effect on contaminants, with significant deposition (~11%) of coarse-grained sediments (63 - 8 µm), and 2) an area characterised by moderate-to-severe-erosion (MSE) to the South, which saw the loss (~13%) of pollutant-bearing fine-grained sediments (<8 µm). A budget calculation in the MSE sub-area showed a loss of ~2.5 tons for Hg and ~700 tons for Zn over three decades, most of which was exported to other parts of the LV or at the open sea. A similar amount is still stored in the SD area, which will be subject to ero- sion if hydrodynamic conditions change in the future. This study provides useful support to decision-making systems by helping to select hot-spots for remediation measures

    Teaching anatomy in a modern medical course: an integrated approach at Vialba Medical School in Milan

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    Introduction The course of Anatomy in Vialba Medical School \u2013 University of Milan, integrates systemic, topographic and development anatomy, dissection laboratory, peer-teaching, flipped classroom, clinical correlation to radiology and surgery. Methods An anonymous questionnaire based on a five-point Likert scale was submitted to 162 students who had passed the exam of Anatomy. Students evaluated the importance given during study to morphology, relations and variations of organs, the usefulness of different tools in preparing the exam of anatomy. Finally, the impact of the new design course of Anatomy on students\u2019 progress was assessed. Results The results showed that most of the students found very useful dissections, multimedia sources and 3D virtual models. 3D virtual models, dissections and physical models were indicated as the most important tools that should be available for learning Anatomy; instead, medical imaging received a low score. Students focused the study on morphology and relations between organs much more than anatomical variations. Lastly, students who followed the new design course of anatomy showed a significant better performance when compared to students of the previous academic years, in particular on the anatomy of neck, thoracic and abdominopelvic cavity, and neuroanatomy. Conclusions Our study underlines the positive impact of the integration of traditional methods and innovative solutions in learning anatomy, but also the critical approach to radiologic imaging and anatomical variability

    Should wheat, barley, rye, and/or gluten be avoided in a 6-food elimination diet?

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    Eosinophilic esophagitis (EoE), a food antigen-mediated disease, is effectively treated with the dietary elimination of six foods commonly associated with food allergies (milk, wheat, egg, soy, tree nuts/peanuts and fish/shellfish). Because wheat shares homologous proteins (including gluten) with barley and rye and may also be processed with these grains, some clinicians have suggested barley and rye may also trigger EoE as a result of cross-reaction and/or cross-contamination with wheat. In this opinion paper, we discuss the theoretical risks of cross-reactivity and cross-contamination among wheat, barley, and rye proteins (including gluten), assess common practices at EoE treatment centers, and provide recommendations for dietary treatment and future studies of EoE

    Fluid gels: a new feedstock for high viscosity jetting

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    Suspensions of gel particles which are pourable or spoonable at room temperature can be created by shearing a gelling biopolymer through its gelation (thermal or ion mediated) rather than allowing quiescent cooling – thus the term ‘fluid gel’ may be used to describe the resulting material. As agar gelation is thermoreversible this type of fluid gel is able to be heated again to melt agar gel particles to varying degrees then re-form a network quiescently upon cooling, whose strength depends on the temperature of re-heating, determining the amount of agar solubilised and subsequently able to partake in re-gelation. Using this principle, for the first time fluid gels have been applied to a high viscosity 3D printing process wherein the printing temperature (at the nozzle) is controllable. This allows the use of ambient temperature feedstocks and by altering the nozzle temperature, the internal nature (presence or absence of gel particles) and gel strength of printed droplets differs. If the nozzle prints at different temperatures for each layer a structure with modulated texture could be created

    Pulmonary hemodynamic responses to in utero ventilation in very immature fetal sheep

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    <p>Abstract</p> <p>Background</p> <p>The onset of ventilation at birth decreases pulmonary vascular resistance (PVR) resulting in a large increase in pulmonary blood flow (PBF). As the large cross sectional area of the pulmonary vascular bed develops late in gestation, we have investigated whether the ventilation-induced increase in PBF is reduced in immature lungs.</p> <p>Methods</p> <p>Surgery was performed in fetal sheep at 105 d GA (n = 7; term ~147 d) to insert an endotracheal tube, which was connected to a neonatal ventilation circuit, and a transonic flow probe was placed around the left pulmonary artery. At 110 d GA, fetuses (n = 7) were ventilated <it>in utero </it>(IUV) for 12 hrs while continuous measurements of PBF were made, fetuses were allowed to develop <it>in utero </it>for a further 7 days following ventilation.</p> <p>Results</p> <p>PBF changes were highly variable between animals, increasing from 12.2 ± 6.6 mL/min to a maximum of 78.1 ± 23.1 mL/min in four fetuses after 10 minutes of ventilation. In the remaining three fetuses, little change in PBF was measured in response to IUV. The increases in PBF measured in responding fetuses were not sustained throughout the ventilation period and by 2 hrs of IUV had returned to pre-IUV control values.</p> <p>Discussion and conclusion</p> <p>Ventilation of very immature fetal sheep <it>in utero </it>increased PBF in 57% of fetuses but this increase was not sustained for more than 2 hrs, despite continuing ventilation. Immature lungs can increase PBF during ventilation, however, the present studies show these changes are transient and highly variable.</p
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