9,848 research outputs found
Successful preoperative bridge with extracorporeal membrane oxygenation in three neonates with D-transposition of the great vessels and pulmonary hypertension
Time Evolution of Temperature and Entropy of Various Collapsing Domain Walls
We investigate the time evolution of the temperature and entropy of
gravitationally collapsing domain walls as seen by an asymptotic observer. In
particular, we seek to understand how topology and the addition of a
cosmological constant affect the gravitational collapse. Previous work has
shown that the entropy of a spherically symmetric collapsing domain approaches
a constant. In this paper, we reproduce these results, using both a fully
quantum and a semi-classical approach, then we repeat the process for a de
Sitter Schwarzschild domain wall (spherical with cosmological constant) and a
(3+1) BTZ domain wall (cylindrical). We do this by coupling a scalar field to
the background of the domain wall and analyzing the spectrum of radiation as a
function of time. We find that the spectrum is quasi-thermal, with the degree
of thermality increasing as the domain wall approaches the horizon. The thermal
distribution allows for the determination of the temperature as a function of
time, and we find that the late time temperature is very close to the Hawking
temperature and that it also exhibits the proper scaling with the mass. From
the temperature we find the entropy. Since the collapsing domain wall is what
forms a black hole, we can compare the results to those of the standard
entropy-area relation. We find that the entropy does in fact approach a
constant that is close to the Hawking entropy. However, both the de Sitter
Schwarzschild domain wall and the (3+1) BTZ domain wall show periods of
decreasing entropy, which suggests that spontaneous collapse may be prevented.Comment: This paper is a merging of two previously submitted papers: Time
Evolution of Temperature and Entropy of a Gravitationally Collapsing Cylinder
[arXiv:1106.2278]; Time Evolution of Temperature and Entropy of a
Gravitationally Collapsing de Sitter Schwarzschild Domain Wal
The relationship between infecting organisms and underlying structural anomalies in children with urinary tract infections
Introduction: Urinary tract infections (UTIs) are a common cause of morbidity in childhood with potential for renal scarring and reflux nephropathy which can lead to hypertension and end-stage renal failure. Aim: The aim of this study was to investigate the relationship between the infecting organism and any underlying anomalies of the urinary tract which may predispose to the development of infections and which may alter the management of children with UTIs. Methods and results: A total of 72 cases of UTI were recorded retrospectively (in- and outpatients), with ages ranging from 3 days to 48 months (mean 9.5, median 5 months). Fifty seven (79%) of patients had their first reported urinary tract infection under the age of 1 year.. Fifty eight (80.6%) were E. coli infections. These presented at an older age than non-E. coli infections. Investigations were abnormal in 31 (43%) cases. The mean age for first infection in patients with abnormal investigations was 7.7 months (median 2 months), younger than those with no renal tract abnormalities. Organisms other than E. coli were rarely found when no significant abnormalities were detected with investigation by US and MCUG and this was a statistically significant difference (p<0.001). Renal scarring was identified in 10 (13.9%) patients. Discussion: This study confirms that non-E. coli UTI is associated with underlying renal pathology and that early infections with any organism are more likely to be associated with underlying abnormalities. We also outline an algorithm based on the recent NICE 2007 guidelines which will be adopted by the Paediatric Department, Mater Dei Hospital for the investigation of UTI.peer-reviewe
The Terrorist Informant
A man sets himself on fire in front of the White House in a dispute with the Federal Bureau of Investigation (FBI). He has been working as an informant for the FBI in a high-profile terrorism prosecution and is unhappy with the $100,000 he has been paid so far. He has also been recently convicted of bank fraud. As a result, the government declines to call him as a witness, given the damage his actions have on his credibility and trustworthiness. This incident underscores the difficulty inherent in relying on paid informants to drive a prosecution, where material considerations such as money and legal assistance are often the price the government pays for an informant’s services. In the years since September 11, 2001, informants have been at the heart of many major terrorism prosecutions. The entrapment defense, perhaps the only legal tool available to defendants in such prosecutions, has proven ineffective. This is evident when one considers the context of generally heightened suspicion of the Arab and Muslim communities in the United States. Further, a closer look at several of these prosecutions reveals repeated instances of suggestive and provocative activity by informants geared at obtaining a conviction, calling into question whether a genuine threat to U.S. national security actually existed in the first place. This Article argues that the government should cease its current practice of using informants to generate terrorism prosecutions
Palestinian Refugees: Host Countries, Legal Status and the Right of Return
Given the Palestinian refugees’ precarious legal status in their host countries, recognition of the Palestinian right of return is not only legally viable, but also crucial for the establishment of a just and lasting peace in the Middle East. That racially driven demographic considerations have been employed up until now to derail binding and directly applicable laws and practices, as well as keep the refugees in a state of legal limbo in their host countries, cuts to the heart of the fundamental injustice currently plaguing the Middle East. No amount of obfuscating the facts and the law can tarnish the applicability and relevance of the right of return, and Palestinian refugees and their advocates remain in both a strong moral and legal position to continue to call for the recognition of that right.Considérant la précarité du statut légal des réfugiés palestiniens dans leur pays hôte, la reconnaissance du Droit au retour des Palestiniens est non seulement légalement viable mais aussi un facteur essentiel pour qu’une paix juste et durable soit établie au Moyen Orient. L’usage – d’inspiration raciste – de facteurs démographiques pour faire échouer jusqu’à présent les lois et les pratiques exécutoires directement applicables et ainsi maintenir les réfugiés dans un état juridique incertain dans leur pays hôte, est au coeur de l’injustice fondamentale qui empoisonne la situation au Moyen-Orient. Toutes les tentatives en vue d’obscurcir les faits et la loi n’arriveront jamais à ternir l’applicabilité et la pertinence du Droit au retour. Les Palestiniens et leurs défenseurs restent donc en position forte, aussi bien au plan moral que légal, pour continuer leur revendication pour la reconnaissance de ce Droit
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