705 research outputs found
High performance astrophysics computing
The application of high end computing to astrophysical problems, mainly in
the galactic environment, is under development since many years at the Dep. of
Physics of Sapienza Univ. of Roma. The main scientific topic is the physics of
self gravitating systems, whose specific subtopics are: i) celestial mechanics
and interplanetary probe transfers in the solar system; ii) dynamics of
globular clusters and of globular cluster systems in their parent galaxies;
iii) nuclear clusters formation and evolution; iv) massive black hole formation
and evolution; v) young star cluster early evolution. In this poster we
describe the software and hardware computational resources available in our
group and how we are developing both software and hardware to reach the
scientific aims above itemized.Comment: 2 pages paper presented at the Conference "Advances in Computational
Astrophysics: methods, tools and outcomes", to be published in the ASP
Conference Series, 2012, vol. 453, R. Capuzzo-Dolcetta, M. Limongi and A.
Tornambe' ed
The origin of the first neutron star -- neutron star merger
The first neutron star-neutron star (NS-NS) merger was discovered on August
17, 2017 through gravitational waves (GW170817) and followed with
electromagnetic observations. This merger was detected in an old elliptical
galaxy with no recent star formation. We perform a suite of numerical
calculations to understand the formation mechanism of this merger. We probe
three leading formation mechanisms of double compact objects: classical
isolated binary star evolution, dynamical evolution in globular clusters and
nuclear cluster formation to test whether they are likely to produce NS-NS
mergers in old host galaxies. Our simulations with optimistic assumptions show
current NS-NS merger rates at the level of 10^-2 yr^-1 from binary stars, 5 x
10^-5 yr^-1 from globular clusters and 10^-5 yr^-1 from nuclear clusters for
all local elliptical galaxies (within 100 Mpc^3). These models are thus in
tension with the detection of GW170817 with an observed rate 1.5 yr^-1 (per 100
Mpc^3; LIGO/Virgo estimate). Our results imply that either (i) the detection of
GW170817 by LIGO/Virgo at their current sensitivity in an elliptical galaxy is
a statistical coincidence; or that (ii) physics in at least one of our three
models is incomplete in the context of the evolution of stars that can form
NS-NS mergers; or that (iii) another very efficient (unknown) formation channel
with a long delay time between star formation and merger is at play.Comment: A&A: accepte
Pemantauan Penerimaan Dosis Eksterna Dan Interna Di Instalasi Radiometalurgi Tahun 2012
PEMANTAUAN PENERIMAAN DOSIS EKSTERNA DAN INTERNA DI INSTALASI RADIOMETALURGI TAHUN 2012. Pemantauan penerimaan dosis eksterna dan interna di Instalasi Radiometalurgi tahun 2012 telah dilakukan. Tujuan dari kegiatan ini untuk mengetahui besarnya dosis eksterna dan interna yang diterima pekerja radiasi dihubungkan dengan kegiatan yang pekerja radiasi lakukan selama bekerja di laboratorium. Metoda yang dilakukan untuk mengevaluasi DEST yang diterima pekerja radiasi ini dengan cara menganalisis dosis eksterna yang berasal dari paparan radiasi dan dosis interna dengan cara in-vitro (pemeriksaan urine) dan in-vivo (Whole Body Counter). Ada beberapa personil yang menerima dosis eksterna triwulan 1 sebesar 0,06 mSv/thn, triwulan 3 antara 0,03 sampai dengan 0,10 mSv/thn sedangkan triwulan 2 dan 4 untuk penerimaan dosis eksterna hasil pemantauan ttd (tak terdeteksi). Hasil pemantauan dosis interna untuk triwulan 1 terpantau sebesar 0,01 mSv/thn, triwulan 4 antara 0,02 sampai dengan 0,09 mSv/thn. Untuk pemantauan triwulan 2 dan 3 hasilnya ttd (tak terdeteksi). Selama tahun 2012 penerimaan dosis eksterna dan interna untuk pekerja radiasi tersebut masih dalam kategori aman karena dosis yang diterima oleh pekerja radiasi masih jauh di bawah batas dosis yang diizinkan. Sesuai dengan Peraturan Kepala Badan Pengawas Tenaga Nuklir No. 4 Tahun 2013 Tentang Proteksi dan Keselamatan Radiasi Dalam Pemanfaatan Tenaga Nuklir dan berdasarkan Laporan Analisis Keselamatan Instalasi Radiometalurgi (LAK IRM), Nilai Batas Dosis yang diijinkan yakni sebesar 50 mSv/thn dan rata-rata 20 mSv dalam 5 tahun
Prevalence and pharmacologic management of familial hypercholesterolemia in an unselected contemporary cohort of patients with stable coronary artery disease
INTRODUCTION:
Familial hypercholesterolemia (FH) is an inherited disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) associated with premature cardiovascular disease.
METHODS:
Using the data from the START (STable Coronary Artery Diseases RegisTry) study, a nationwide, prospective survey on patients with stable coronary artery disease (CAD), we described prevalence and lipid lowering strategies commonly employed in these patients. The study population was divided into "definite/probable FH," defined as a Dutch Lipid Clinic Network (DLCN) score ≥6, "possible FH" with DLCN 3-5, and "unlikely FH" in presence of a DLCN <3.
RESULTS:
Among the 4030 patients with the DLCN score available, 132 (3.3%) were classified as FH (2.3% with definite/probable and 1.0% with possible FH) and 3898 (96.7%) had unlikely FH. Patients with both definite/probable and possible FH were younger compared to patients not presenting FH. Mean on-treatment LDL-C levels were 107.8 ± 41.5, 84.4 ± 40.9, and 85.8 ± 32.3 (P < 0.0001) and a target of ≤70 mg/dL was reached in 10.9%, 30.0%, and 22.0% (P < 0.0001) of patents with definite/probable, possible FH, and unlikely FH, respectively. Statin therapy was prescribed in 85 (92.4%) patients with definite/probable FH, in 38 (95.0%) with possible FH, and in 3621 (92.9%) with unlikely FH (P = 0.86). The association of statin and ezetimibe, in absence of other lipid-lowering therapy, was more frequently used in patients with definite/probable FH compared to patients without FH (31.5% vs 17.5% vs 9.5%; P < 0.0001).
CONCLUSIONS:
In this large cohort of consecutive patients with stable CAD, FH was highly prevalent and generally undertreated with lipid lowering therapies
Familial hypercholesterolemia: The Italian Atherosclerosis Society Network (LIPIGEN)
Primary dyslipidemias are a heterogeneous group of disorders characterized by abnormal levels of circulating lipoproteins. Among them, familial hypercholesterolemia is the most common lipid disorder that predisposes for premature cardiovascular disease. We set up an Italian nationwide network aimed at facilitating the clinical and genetic diagnosis of genetic dyslipidemias named LIPIGEN (LIpid TransPort Disorders Italian GEnetic Network)
Evaluation of polygenic determinants of non-alcoholic fatty liver disease (NAFLD) by a candidate genes resequencing strategy
NAFLD is a polygenic condition but the individual and cumulative contribution of identified genes remains to be established. To get additional insight into the genetic architecture of NAFLD, GWAS-identified GCKR, PPP1R3B, NCAN, LYPLAL1 and TM6SF2 genes were resequenced by next generation sequencing in a cohort of 218 NAFLD subjects and 227 controls, where PNPLA3 rs738409 and MBOAT7 rs641738 genotypes were also obtained. A total of 168 sequence variants were detected and 47 were annotated as functional. When all functional variants within each gene were considered, only those in TM6SF2 accumulate in NAFLD subjects compared to controls (P = 0.04). Among individual variants, rs1260326 in GCKR and rs641738 in MBOAT7 (recessive), rs58542926 in TM6SF2 and rs738409 in PNPLA3 (dominant) emerged as associated to NAFLD, with PNPLA3 rs738409 being the strongest predictor (OR 3.12, 95% CI, 1.8-5.5, P 0.28 was associated with a 3-fold increased risk of NAFLD. Interestingly, rs61756425 in PPP1R3B and rs641738 in MBOAT7 genes were predictors of NAFLD severity. Overall, TM6SF2, GCKR, PNPLA3 and MBOAT7 were confirmed to be associated with NAFLD and a score based on these genes was highly predictive of this condition. In addition, PPP1R3B and MBOAT7 might influence NAFLD severity
Diradical Character of Neutral Heteroleptic Bis(1,2-dithiolene) Metal Complexes: Case Study of [Pd(Me2timdt)(mnt)] (Me2timdt = 1,3-Dimethyl-2,4,5-trithioxoimidazolidine; mnt2-= 1,2-Dicyano-1,2-ethylenedithiolate)
The reaction of the bis(1,2-dithiolene) complex [Pd(Me2timdt)2] (1; Me2timdt•- = monoreduced 1,3-dimethyl-2,4,5-trithioxoimidazolidine) with Br2 yielded the complex [Pd(Me2timdt)Br2] (2), which was reacted with Na2mnt (mnt2- = 1,2-dicyano-1,2-ethylenedithiolate) to give the neutral mixed-ligand complex [Pd(Me2timdt)(mnt)] (3). Complex 3 shows an intense solvatochromic near-infrared (NIR) absorption band falling between 955 nm in DMF and 1060 nm in CHCl3 (ϵ = 10700 M-1 cm-1 in CHCl3). DFT calculations were used to elucidate the electronic structure of complex 3 and to compare it with those of the corresponding homoleptic complexes 1 and [Pd(mnt)2] (4). An in-depth comparison of calculated and experimental structural and vis-NIR spectroscopic properties, supported by IEF-PCM TD-DFT and NBO calculations, clearly points to a description of 3 as a dithione-dithiolato complex. For the first time, a broken-symmetry (BS) procedure for the evaluation of the singlet diradical character (DC) of heteroleptic bis(1,2-dithiolene) complexes has been developed and applied to complex 3. The DC, predominant for 1 (nDC = 55.4%), provides a remarkable contribution to the electronic structures of the ground states of both 3 and 4, showing a diradicaloid nature (nDC = 24.9% and 27.5%, respectively). The computational approach developed here clearly shows that a rational design of the DC of bis(1,2-ditiolene) metal complexes, and hence their linear and nonlinear optical properties, can be achieved by a proper choice of the 1,2-dithiolene ligands based on their electronic structure
Space Images for NASA JPL Android Version
This software addresses the demand for easily accessible NASA JPL images and videos by providing a user friendly and simple graphical user interface that can be run via the Android platform from any location where Internet connection is available. This app is complementary to the iPhone version of the application. A backend infrastructure stores, tracks, and retrieves space images from the JPL Photojournal and Institutional Communications Web server, and catalogs the information into a streamlined rating infrastructure. This system consists of four distinguishing components: image repository, database, server-side logic, and Android mobile application. The image repository contains images from various JPL flight projects. The database stores the image information as well as the user rating. The server-side logic retrieves the image information from the database and categorizes each image for display. The Android mobile application is an interfacing delivery system that retrieves the image information from the server for each Android mobile device user. Also created is a reporting and tracking system for charting and monitoring usage. Unlike other Android mobile image applications, this system uses the latest emerging technologies to produce image listings based directly on user input. This allows for countless combinations of images returned. The backend infrastructure uses industry-standard coding and database methods, enabling future software improvement and technology updates. The flexibility of the system design framework permits multiple levels of display possibilities and provides integration capabilities. Unique features of the software include image/video retrieval from a selected set of categories, image Web links that can be shared among e-mail users, sharing to Facebook/Twitter, marking as user's favorites, and image metadata searchable for instant results
Ten years since the introduction of therapeutic hypothermia in neonates with perinatal hypoxic-ischaemic encephalopathy in Spain
More than a decade has passed since therapeutic hypothermia (TH) was introduced in Spain; this is the only neuroprotective intervention that has become standard practice in the treatment of perinatal hypoxic-ischaemic encephalopathy (HIE). This article aims to provide a current picture of the technique and to address the controversies surrounding its use. In the last 10 years, TH has been successfully implemented in the vast majority of tertiary hospitals in Spain, and more than 85% of newborns with moderate or severe HIE currently receive the treatment. The factors that can improve the efficacy of TH include early treatment onset (first 6 hours of life) and the control of comorbid factors associated with perinatal asphyxia. In patients with moderate HIE, treatment onset after 6 hours seems to have some neuroprotective efficacy. TH duration longer than 72 hours or deeper hypothermia do not offer greater neuroprotective efficacy, but instead increase the risk of adverse effects. Unclarified aspects are the sedation of patients during TH, the application of the treatment in infants with mild HIE, and its application in other scenarios. Prognostic information and time frame are one of the most challenging aspects. TH is universal in countries with sufficient economic resources, although certain unresolved controversies remain. While the treatment is widespread in Spain, there is a need for cooling devices for the transfer of these patients and their centralisationSe cumple ahora más de una década del inicio de la hipotermia terapéutica (HT) en España, la única intervención neuroprotectora que ha venido a ser práctica estándar en el tratamiento de la encefalopatÃa hipóxico-isquémica perinatal (EHI). El objetivo de este artÃculo es ofrecer un panorama actual y presentar las controversias surgidas alrededor de la aplicación de esta terapia.
En esta década se ha implantado con éxito la HT en la gran mayorÃa de los hospitales terciarios de España y más del 85% de los recién nacidos con EHI moderada-grave reciben esta terapia. Entre los aspectos que pueden mejorar la eficacia de la HT están su inicio precoz dentro de las primeras 6 horas de vida y el control de factores comórbidos asociados a la asfixia perinatal. En los pacientes con EHI moderada el inicio después de las 6 horas parece mantener cierta eficacia neuroprotectora. Una duración de la HT mayor de 72 horas o un enfriamiento más profundo no ofrecen mayor eficacia neuroprotectora y aumentan el riesgo de efectos adversos. Persiste la controversia acerca de la sedación durante la HT, la aplicación de esta intervención a los neonatos con EHI leve y en otros escenarios. La información pronóstica y su marco temporal es uno de los aspectos más desafiantes.
La HT es universal en paÃses con recursos económicos, aunque existen puntos de controversia no resueltos. Si bien es un tratamiento generalizado en nuestro paÃs, falta disponer de dispositivos para el traslado de estos pacientes y su centralizació
TRASTORNOS DE PERSONALIDAD EN CONSUMIDORES DE DROGAS: DATOS PRELIMINARES
Comorbility between licit and illicit drugs and personality disorders is studied in a sample of 320 adults who attended specialized addictions service. There is a predominance of single-male participants with a starting age at 20 on drug consumption while consultation begins around 35. Fifty percent of the consultations correspond to alcohol in both sexes. The more frequent illicit drugs were marijuana and cocaine. Gender differences were found. Firstly, the use of sedatives in women and of marijuana in men, and, secondly different personality profiles. The more predominant personality disorders were the ones of the cluster B. The consumption of illicit drugs is associated with the borderline and antisocial personality disorders. In men, this was found concurrently with narcissistic personality disorder and in women, with the dependent and histrionic personality disorders.Se estudia la Comorbilidad entre consumo de drogas legales e ilegales y el tipo de Trastorno de Personalidad en una muestra de 320 adultos: a través de Entrevista ClÃnica Psiquiátrica (estandarizada y normatizada) a pacientes que concurrieron a un servicio especializado en adicciones. Hay un predominio del sexo masculino, solteros, con edad de inicio en el consumo de drogas de 20 años y de consulta –promedio- de 35 años. El 50% de las consultas fue por alcohol, en ambos sexos. Las drogas ilegales más frecuentes fueron marihuana y cocaÃna. Se encontraron diferencias de género, entre ellas, el consumo de sedantes propio de las mujeres y el de marihuana en los hombres, asà como un perfil de personalidad diferente. En los Trastornos de Personalidad predominaron los del grupo B. El consumo de drogas ilegales se asocia a los Trastornos Disocial y LÃmite. En los hombres se agrega el Narcisista y en las mujeres el Histriónico y Dependiente
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