11,780 research outputs found
Acute Respiratory Tract Infections and How to Treat Them
Get PDFAcute respiratory tract infections (ARTIs) are one of the most common clinical encounters in primary care settings and they often lead to antibiotic prescriptions. However, more than 90% of ARTIs are caused by viral syndromes. Evidence has showed that interventions addressed at antibiotic prescription practices for ARTIs are critical to combatting the widespread overuse of antibiotics and increase in antibiotic resistance infections in the US. Providers report pressure from patients to prescribe antibiotics even when they are not clinical indicated and patients have several misconceptions surrounding the clinical course of ARTIs that lead to this behavior. A brochure was developed to address the symptoms and duration of various types of ARTIs, the supportive treatment that can provide relief, and the dangers of antibiotic overuse and resistant infections. This brochure can be used in primary care settings to reduce pressure from patients to provide antibiotics by educating them on antibiotics are rarely indicated for ARTIs.https://scholarworks.uvm.edu/fmclerk/1569/thumbnail.jp
Partial dosage compensation in Strepsiptera, a sister group of beetles.
Get PDFSex chromosomes have evolved independently in many different taxa, and so have mechanisms to compensate for expression differences on sex chromosomes in males and females. Different clades have evolved vastly different ways to achieve dosage compensation, including hypertranscription of the single X in male Drosophila, downregulation of both Xs in XX Caenorhabditis, or inactivation of one X in female mammals. In the flour beetle Tribolium, the X appears hyperexpressed in both sexes, which might represent the first of two steps to evolve dosage compensation along the paths mammals may have taken (i.e., upregulation of X in both sexes, followed by inactivation of one X in females). Here we test for dosage compensation in Strepsiptera, a sister taxon to beetles. We identify sex-linked chromosomes in Xenos vesparum based on genomic analysis of males and females, and show that its sex chromosome consists of two chromosomal arms in Tribolium: The X chromosome that is shared between Tribolium and Strepsiptera, and another chromosome that is autosomal in Tribolium and another distantly related Strepsiptera species, but sex-linked in X. vesparum. We use RNA-seq (RNA sequencing) to show that dosage compensation along the X of X. vesparum is partial and heterogeneous. In particular, genes that are X-linked in both beetles and Strepsiptera appear fully dosage compensated probably through downregulation in both sexes, whereas genes on the more recently added X segment have evolved only partial dosage compensation. In addition, reanalysis of published RNA-seq data suggests that Tribolium has evolved dosage compensation, without hypertranscribing the X in females. Our results demonstrate that patterns of dosage compensation are highly variable across sex-determination systems and even within species
Chirp assisted ion acceleration via relativistic self induced transparency
Full text linkWe study the effect of the chirped laser pulse on the transmission and
associated ion acceleration by the sub-wavelength target. In the chirped laser
pulses, the pulse frequency has a temporal variation about its fundamental
frequency,
which manifests to the temporal dependence of the critical density ().
In this work we used a chirp model which is beyond the linear approximation.
For negatively (positively) chirped pulses, the high (low) frequency component
of the pulse interacts with the target initially followed by the low (high)
frequency component. The threshold plasma density for the transmission of the
pulse is found to be higher for the negatively chirped laser pulses as compared
to the unchirped or positively chirped pulses. The enhanced transmission of the
negatively chirped pulses for higher densities () results in very
efficient heating of the target electrons, creating a very stable and
persistent longitudinal electrostatic field behind the target. The void of the
electrons results in expansion of the target ions in either direction,
resulting in the broad energy spectrum. We have introduced a very thin, low
density () secondary layer behind the primary layer. The ions from the
secondary layer are then found to be accelerated as a mono-energetic bunch
under the influence of the electrostatic field created by the primary layer
upon interaction by the negatively chirped pulse. Under the optimum conditions,
the maximum energy of the protons are found to be MeV for 10 fs
(intensity fwhm); Circularly Polarized; Gaussian; negatively chirped laser
pulse with peak intensity W/cm.Comment: 9 pages, 10 figure
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