209 research outputs found
Gauge Orbit Types for Theories with Classical Compact Gauge Group
We determine the orbit types of the action of the group of local gauge
transformations on the space of connections in a principal bundle with
structure group O(n), SO(n) or over a closed, simply connected manifold
of dimension 4. Complemented with earlier results on U(n) and SU(n) this
completes the classification of the orbit types for all classical compact gauge
groups over such space-time manifolds. On the way we derive the classification
of principal bundles with structure group SO(n) over these manifolds and the
Howe subgroups of SO(n).Comment: 57 page
Biztonságos Scrum változatok áttekintése
A hatékony szoftverfejlesztés egyik alapfeltétele a megfelelő módszertan kiválasztása és alkalmazása. Napjaink egyik legelterjedtebb módszertana a Scrum, amit sok ezer projekt során alkalmaztak sikeresen. Számos előnyös tulajdonsága ellenére a Scrum gyenge pontja az, hogy nem kínál teljes értékű megoldást biztonságkritikus szoftverek fejlesztésére, pl.
nem tartalmaz explicit módon biztonsági elemzést és tervezést.
Cikkünkben két olyan módszertant (S-Scrum és Secure Scrum)
is áttekintünk és értékelünk, ami az eredeti eljárást alkalmassá teszi biztonságkritikus szoftverek fejlesztésére újabb lépések és komponensek beépítésével
Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector
Detector-plane prototypes of the very forward calorimetry of a future
detector at an e+e- collider have been built and their performance was measured
in an electron beam. The detector plane comprises silicon or GaAs pad sensors,
dedicated front-end and ADC ASICs, and an FPGA for data concentration.
Measurements of the signal-to-noise ratio and the response as a function of the
position of the sensor are presented. A deconvolution method is successfully
applied, and a comparison of the measured shower shape as a function of the
absorber depth with a Monte-Carlo simulation is given.Comment: 25 pages, 32 figures, revised version following comments from
referee
MicroRNA 10a Marks Regulatory T Cells
MicroRNAs (miRNAs) are crucial for regulatory T cell (Treg) stability and function. We report that microRNA-10a (miR-10a) is expressed in Tregs but not in other T cells including individual thymocyte subsets. Expression profiling in inbred mouse strains demonstrated that non-obese diabetic (NOD) mice with a genetic susceptibility for autoimmune diabetes have lower Treg-specific miR-10a expression than C57BL/6J autoimmune resistant mice. Inhibition of miR-10a expression in vitro leads to reduced FoxP3 expression levels and miR-10a expression is lower in unstable “exFoxP3” T cells. Unstable in vitro TGF-ß-induced, iTregs do not express miR-10a unless cultured in the presence of retinoic acid (RA) which has been associated with increased stability of iTreg, suggesting that miR-10a might play a role in stabilizing Treg. However, genetic ablation of miR-10a neither affected the number and phenotype of natural Treg nor the capacity of conventional T cells to induce FoxP3 in response to TGFβ, RA, or a combination of the two. Thus, miR-10a is selectively expressed in Treg but inhibition by antagomiRs or genetic ablation resulted in discordant effects on FoxP3
Hepatobiliary and pancreatic tuberculosis: A two decade experience
<p>Abstract</p> <p>Background</p> <p>Isolated hepatobiliary or pancreatic tuberculosis (TB) is rare and preoperative diagnosis is difficult. We reviewed our experience over a period two decades with this rare site of abdominal tuberculosis.</p> <p>Methods</p> <p>The records of 18 patients with proven histological diagnosis of hepatobiliary and pancreatic tuberculosis were reviewed retrospectively. The demographic features, sign and symptoms, imaging, cytology/histopathology, procedures performed, outcome and follow up data were obtained from the departmental records. The diagnosis of tuberculosis was based on granuloma with caseation necrosis on histopathology or presence of acid fast bacilli.</p> <p>Results</p> <p>Of 18 patients (11 men), 11 had hepatobiliary TB while 7 had pancreatic TB. Two-thirds of the patients were < 40 years (mean: 42 yrs; range 19–70 yrs). The duration of the symptoms varied between 2 weeks to 104 weeks (mean: 20 weeks). The most common symptom was pain in the abdomen (n = 13), followed by jaundice (n = 10), fever, anorexia and weight loss (n = 9). Five patients (28%) had associated extra-abdominal TB which helped in preoperative diagnosis in 3 patients. Imaging demonstrated extrahepatic bile duct obstruction in the patients with jaundice and in addition picked up liver, gallbladder and pancreatic masses with or without lymphadenopathy (peripancreatic/periportal). Preoperative diagnosis was made in 4 patients and the other 14 were diagnosed after surgery. Two patients developed significant postoperative complications (pancreaticojejunostomy leak <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> intraabdominal abscess <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>) and 3 developed ATT induced hepatotoxicity. No patient died. The median follow up period was 12 months (9 – 96 months).</p> <p>Conclusion</p> <p>Tuberculosis should be considered as a differential diagnosis, particularly in young patients, with atypical signs and symptoms coming from areas where tuberculosis is endemic and preoperative tissue and/or cytological diagnosis should be attempted before labeling them as hepatobiliary and pancreatic malignancy.</p
Aberrant Herpesvirus-Induced Polyadenylation Correlates With Cellular Messenger RNA Destruction
Inhibition of host cell gene expression by the human herpesvirus KSHV occurs via a novel mechanism involving polyadenylation-linked RNA turnover
Phospholipids Trigger Cryptococcus neoformans Capsular Enlargement during Interactions with Amoebae and Macrophages
A remarkable aspect of the interaction of Cryptococcus
neoformans with mammalian hosts is a consistent increase in capsule
volume. Given that many aspects of the interaction of C.
neoformans with macrophages are also observed with amoebae, we
hypothesized that the capsule enlargement phenomenon also had a protozoan
parallel. Incubation of C. neoformans with Acanthamoeba
castellanii resulted in C. neoformans capsular
enlargement. The phenomenon required contact between fungal and protozoan cells
but did not require amoeba viability. Analysis of amoebae extracts showed that
the likely stimuli for capsule enlargement were protozoan polar lipids. Extracts
from macrophages and mammalian serum also triggered cryptococcal capsular
enlargement. C. neoformans capsule enlargement required
expression of fungal phospholipase B, but not phospholipase C. Purified
phospholipids, in particular, phosphatidylcholine, and derived molecules
triggered capsular enlargement with the subsequent formation of giant cells.
These results implicate phospholipids as a trigger for both C.
neoformans capsule enlargement in vivo and
exopolysaccharide production. The observation that the incubation of C.
neoformans with phospholipids led to the formation of giant cells
provides the means to generate these enigmatic cells in vitro.
Protozoan- or mammalian-derived polar lipids could represent a danger signal for
C. neoformans that triggers capsular enlargement as a
non-specific defense mechanism against potential predatory cells. Hence,
phospholipids are the first host-derived molecules identified to trigger
capsular enlargement. The parallels apparent in the capsular response of
C. neoformans to both amoebae and macrophages provide
additional support for the notion that certain aspects of cryptococcal virulence
emerged as a consequence of environmental interactions with other microorganisms
such as protists
Cost-Effectiveness Analysis of Diagnostic Options for Pneumocystis Pneumonia (PCP)
Diagnosis of Pneumocystis jirovecii pneumonia (PCP) is challenging, particularly in developing countries. Highly sensitive diagnostic methods are costly, while less expensive methods often lack sensitivity or specificity. Cost-effectiveness comparisons of the various diagnostic options have not been presented.We compared cost-effectiveness, as measured by cost per life-years gained and proportion of patients successfully diagnosed and treated, of 33 PCP diagnostic options, involving combinations of specimen collection methods [oral washes, induced and expectorated sputum, and bronchoalveolar lavage (BAL)] and laboratory diagnostic procedures [various staining procedures or polymerase chain reactions (PCR)], or clinical diagnosis with chest x-ray alone. Our analyses were conducted from the perspective of the government payer among ambulatory, HIV-infected patients with symptoms of pneumonia presenting to HIV clinics and hospitals in South Africa. Costing data were obtained from the National Institutes of Communicable Diseases in South Africa. At 50% disease prevalence, diagnostic procedures involving expectorated sputum with any PCR method, or induced sputum with nested or real-time PCR, were all highly cost-effective, successfully treating 77-90% of patients at 189-232 per life-year gained. A relatively cost-effective diagnostic procedure that did not require PCR was Toluidine Blue O staining of induced sputum (109 per life-year gained) compared with several molecular diagnostic options.For diagnosis of PCP, use of PCR technologies, when combined with less-invasive patient specimens such as expectorated or induced sputum, represent more cost-effective options than any diagnostic procedure using BAL, or chest x-ray alone
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