Pulsar Results with the Fermi Large Area Telescope

The launch of the Fermi Gamma-ray Space Telescope has heralded a new era in the study of gamma-ray pulsars. The population of confirmed gamma-ray pulsars has gone from 6-7 to more than 60, and the superb sensitivity of the Large Area Telescope (LAT) on Fermi has allowed the detailed study of their spectra and light curves. Twenty-four of these pulsars were discovered in blind searches of the gamma-ray data, and twenty-one of these are, at present, radio quiet, despite deep radio follow-up observations. In addition, millisecond pulsars have been confirmed as a class of gamma-ray emitters, both individually and collectively in globular clusters. Recently, radio searches in the direction of LAT sources with no likely counterparts have been highly productive, leading to the discovery of a large number of new millisecond pulsars. Taken together, these discoveries promise a great improvement in the understanding of the gamma-ray emission properties and Galactic population of pulsars. We summarize some of the results stemming from these newly-detected pulsars and their timing and multi-wavelength follow-up observations.Comment: 21 pages, 9 figures, to appear in Proceedings of ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain, 2010 April 12-16 (Springer

Ar dreno pašalinimo laikas turi įtakos pirminio spontaninio pneumotorakso pirmojo epizodo gydymo išeitims?

Background / objectives. The main treatment option for the first episode of primary spontaneous pneumothorax is chest tube drainage, however, whether delayed chest tube removal might influence the recurrence is unclear.Methods. A prospective study, which included 50 patients, with an initial episode of primary spontaneous pneumothorax was performed. Patients were randomized into two groups according to the chest tube removal time: 1-day and 5-days after the air-leak has stopped. All patients were followed-up for at least six months. Both groups were compared according to the recurrence rate and possible complications.Results. There were 39 (78%) men and the median age was 27 (23–35) years. Successful management with a chest tube was achieved in 43 (86%) patients, others were operated on because of the continuous air-leak or relapse of the pneumothorax after the chest tube was removed. Significant difference was not found comparing groups by age, gender, side, tobacco smoking, alpha-1-antitrypsin level, rate of prolonged air-leak, necessity of surgery, and the mean follow-up time. There was a significant difference between groups in hospitalization time: 1-day group – 6 (4–12), 5-days group – 8 (7–10) days, p = 0.017. Five (20%) patients from 1-day group and 3 (12%) from 5-days group had a recurrence, however the difference was not significant (p = 0.702). There were no significant differences comparing groups by the recurrence time or complications.Conclusions. The recurrence rate of primary spontaneous pneumothorax was higher if the chest tube was removed earlier, however not significantly. More data and longer follow-up are necessary to confirm these findings.Įvadas / tikslas. Pirminis spontaninis pneumotoraksas yra didelė jaunų sveikų žmonių problema. Pleuros ertmės drenavimas – pagrindinis pirminio spontaninio pneumotorakso pirmojo epizodo gydymo būdas. Vis dėlto nėra žinoma, ar dreno buvimo pleuros ertmėje trukmė gali turėti įtakos recidyvų dažniui.Metodai. Atliktas perspektyvusis tyrimas, į kurį įtraukta 50 pacientų. Tiriamiesiems diagnozuotas pirminio spontaninio pneumotorakso pirmasis epizodas. Visi pacientai gydyti drenuojant pleuros ertmę. Pacientai suskirstyti į dvi grupes, atsižvelgiant į dreno pašalinimo laiką: praėjus vienai dienai ar praėjus penkioms dienoms, kai per dreną nustojo skirtis oras. Visi pacientai atokiu laikotarpiu (mažiausiai šešis mėnesius) stebėti dėl galimo recidyvo. Atlikta abiejų grupių recidyvų dažnio ir galimų komplikacijų lyginamoji analizė.Rezultatai. Vidutinis pacientų amžius – 27 (23–35) metai. 78 proc. tiriamųjų – vyrai. Drenavus pleuros ertmę, sėkmingai išgydyti 43 ligoniai (86 %). Kiti tiriamieji dėl besiskiriančio per dreną oro ar dėl rentgenogramoje matomo pakartotinio pneumotorakso, pašalinus dreną, buvo operuoti. Abiejų tiriamųjų grupių duomenys pagal amžių, lytį, pneumotorakso pasireiškimo krūtinės ląstoje pusę, rūkymą, alfa-1 antitripsino koncentraciją kraujyje, ilgesnį oro skyrimąsi per dreną ar operacijos poreikį statistiškai reikšmingai nesiskyrė. Statistiškai reikšmingai skyrėsi abiejų grupių hospitalizacijos trukmė: tiriamieji, kuriems, nustojus per dreną skirtis orui, drenas pašalintas praėjus vienai dienai, ligoninėje gulėjo vidutiniškai 6 (4–12) dienas, o tiriamieji, kuriems drenas pašalintas praėjus penkioms dienoms, – 8 (7–10) dienas (p = 0,017). Penkiems (20 %) pirmosios grupės ir trims (12 %) antrosios grupės pacientams pneumotoraksas recidyvavo (skirtumas statistiškai nereikšmingas (p = 0,702)). Statistiškai nereikšmingas skirtumas nustatytas ir tarp abiejų grupių recidyvo laiko bei komplikacijų.Išvados. Pirminio spontaninio pneumotorakso recidyvų dažnis kiek didesnis, kai drenas ištraukiamas anksčiau, tačiau lyginamųjų grupių skirtumas statistiškai nereikšmingas. Siekiant patvirtinti gautus rezultatus, reikia atlikti didesnės apimties tyrimą, būtina ilgiau stebėti tiriamuosius

Observation of second-harmonic generation induced by pure spin currents

Extensive efforts are currently being devoted to developing a new electronic technology, called spintronics, where the spin of electrons is explored to carry information. [1,2] Several techniques have been developed to generate pure spin currents in many materials and structures. [3-10] However, there is still no method available that can be used to directly detect pure spin currents, which carry no net charge current and no net magnetization. Currently, studies of pure spin currents rely on measuring the induced spin accumulation with optical techniques [5, 11-13] or spin-valve configurations. [14-17] However, the spin accumulation does not directly reflect the spatial distribution or temporal dynamics of the pure spin current, and therefore cannot monitor the pure spin current in a real-time and real-space fashion. This imposes severe constraints on research in this field. Here we demonstrate a second-order nonlinear optical effect of the pure spin current. We show that such a nonlinear optical effect, which has never been explored before, can be used for the non-invasive, non-destructive, and real-time imaging of pure spin currents. Since this detection scheme does not rely on optical resonances, it can be generally applied in a wide range of materials with different electronic bandstructures. Furthermore, the control of nonlinear optical properties of materials with pure spin currents may have potential applications in photonics integrated with spintronics.Comment: 19 pages, 3 figures, supplementary discussion adde

Genomic characterization of large rearrangements of the LDLR gene in Czech patients with familial hypercholesterolemia

<p>Abstract</p> <p>Background</p> <p>Mutations in the <it>LDLR </it>gene are the most frequent cause of Familial hypercholesterolemia, an autosomal dominant disease characterised by elevated concentrations of LDL in blood plasma. In many populations, large genomic rearrangements account for approximately 10% of mutations in the <it>LDLR </it>gene.</p> <p>Methods</p> <p>DNA diagnostics of large genomic rearrangements was based on Multiple Ligation dependent Probe Amplification (MLPA). Subsequent analyses of deletion and duplication breakpoints were performed using long-range PCR, PCR, and DNA sequencing.</p> <p>Results</p> <p>In set of 1441 unrelated FH patients, large genomic rearrangements were found in 37 probands. Eight different types of rearrangements were detected, from them 6 types were novel, not described so far. In all rearrangements, we characterized their exact extent and breakpoint sequences.</p> <p>Conclusions</p> <p>Sequence analysis of deletion and duplication breakpoints indicates that intrachromatid non-allelic homologous recombination (NAHR) between <it>Alu </it>elements is involved in 6 events, while a non-homologous end joining (NHEJ) is implicated in 2 rearrangements. Our study thus describes for the first time NHEJ as a mechanism involved in genomic rearrangements in the <it>LDLR </it>gene.</p

Radio pulsar populations

The goal of this article is to summarize the current state of play in the field of radio pulsar statistics. Simply put, from the observed sample of objects from a variety of surveys with different telescopes, we wish to infer the properties of the underlying sample and to connect these with other astrophysical populations (for example supernova remnants or X-ray binaries). The main problem we need to tackle is the fact that, like many areas of science, the observed populations are often heavily biased by a variety of selection effects. After a review of the main effects relevant to radio pulsars, I discuss techniques to correct for them and summarize some of the most recent results. Perhaps the main point I would like to make in this article is that current models to describe the population are far from complete and often suffer from strong covariances between input parameters. That said, there are a number of very interesting conclusions that can be made concerning the evolution of neutron stars based on current data. While the focus of this review will be on the population of isolated Galactic pulsars, I will also briefly comment on millisecond and binary pulsars as well as the pulsar content of globular clusters and the Magellanic Clouds.Comment: 16 pages, 6 figures, to appear in Proceedings of ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain, 2010 April 12-16 (Springer

The role of guidelines and the patient's life-style in GPs' management of hypercholesterolaemia

BACKGROUND: Recent Swedish and joint European guidelines on hyperlipidaemia stress the high coronary risk for patients with already established arterio-sclerotic disease (secondary prevention) or diabetes. For the remaining group, calculation of the ten-year risk for coronary events using the Framingham equation is suggested. There is evidence that use of and adherence to guidelines is incomplete and that tools for risk estimations are seldom used. Intuitive risk estimates are difficult and systematically biased. The purpose of the study was to examine how GPs use knowledge of guidelines in their decisions to recommend or not recommend a cholesterol-lowering drug and the reasons for their decisions. METHODS: Twenty GPs were exposed to six case vignettes presented on a computer. In the course of six screens, successively more information was added to the case. The doctors were instructed to think aloud while processing the cases (Think-Aloud Protocols) and finally to decide for or against drug treatment. After the six cases they were asked to describe how they usually reason when they meet patients with high cholesterol values (Free-Report Protocols). The two sets of protocols were coded for cause-effect relations that were supposed to reflect the doctors' knowledge of guidelines. The Think-Aloud Protocols were also searched for reasons for the decisions to prescribe or not to prescribe. RESULTS: According to the protocols, the GPs were well aware of the importance of previous coronary heart disease and diabetes in their decisions. On the other hand, only a few doctors mentioned other arterio-sclerotic diseases like stroke and peripheral artery disease as variables affecting their decisions. There were several instances when the doctors' decisions apparently deviated from their knowledge of the guidelines. The arguments for the decisions in these cases often concerned aspects of the patient's life-style like smoking or overweight- either as risk-increasing factors or as alternative strategies for intervention. CONCLUSIONS: Coding verbal protocols for knowledge and for decision arguments seems to be a valuable tool for increasing our understanding of how guidelines are used in the on treatment of hypercholesterolaemia. By analysing arguments for treatment decisions it was often possible to understand why departures from the guidelines were made. While the need for decision support is obvious, the current guidelines may be too simple in some respects

Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care

<p>Abstract</p> <p>Background</p> <p>Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate.</p> <p>Methods</p> <p>N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical information, and echocardiographic data of left ventricular systolic function were collected in 542 family practice patients with at least one cardiovascular risk factor. We determined the diagnostic power of the NT-proBNP assessment in ruling out left ventricular systolic dysfunction and compared it to a risk score derived from a logistic regression model of easily acquired clinical information.</p> <p>Results</p> <p>23 of 542 patients showed left ventricular systolic dysfunction. Both NT-proBNP and the clinical risk score consisting of dyspnea at exertion and ankle swelling, coronary artery disease and diuretic treatment showed excellent diagnostic power for ruling out left ventricular systolic dysfunction. AUC of NT-proBNP was 0.83 (95% CI, 0.75 to 0.92) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.46 (95% CI, 0.41 to 0.50). AUC of the clinical risk score was 0.85 (95% CI, 0.79 to 0.91) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.64 (95% CI, 0.59 to 0.67). 148 misclassifications using NT-proBNP and 55 using the clinical risk score revealed a significant difference (McNemar test; p < 0.001) that was based on the higher specificity of the clinical risk score.</p> <p>Conclusion</p> <p>The evaluation of clinical information is at least as effective as NT-proBNP testing in ruling out left ventricular systolic dysfunction in family practice patients at risk. If these results are confirmed in larger cohorts and in different samples, family physicians should be encouraged to rely on the diagnostic power of the clinical information from their patients.</p

Mixed-marker approach suggests maternal philopatry and sex-biased behaviours of narrow sawfish Anoxypristis cuspidata

ABSTRACT: The narrow sawfish Anoxypristis cuspidata belongs to the most endangered family of chondrichthyan fishes, the sawfishes (Pristidae). This species has undergone significant declines in geographic range and abundance due to anthropogenic activities including fishing and habitat destruction. Very little is known of adult movements within its distribution. In order to better manage and protect this endangered species, understanding patterns of habitat use, connectivity and behaviour is important. Using a combination of partial mitochondrial sequences (control region [CR] and NADH dehydrogenase 4 [ND4]) and nuclear markers (microsatellites), this study assessed the genetic population structure of A. cuspidata in Australia and Papua New Guinea. Significant population structuring using mitochondrial DNA was found between the east Australian coast, Gulf of Papua and Gulf of Carpentaria (using concatenated CR and ND4 markers) (analysis of molecular variance [AMOVA], ΦST = 0.082, p = FST = 0.012, p = 1.000). Our results suggest that a combination of historic genetic drift, maternal natal philopatry and possible male-biased dispersal likely drive the genetic patterns observed. Given the endangered status and lack of knowledge for A. cuspidata, this study presents important insights that may be used to inform management efforts

Introduction : From Fundamentals to Advances in Crowdfunding Research and Practice

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