8,426 research outputs found
Fermi pulsar revolution
2009 has been an extraordinary year for gamma-ray pulsar astronomy and 2010
promises to be equally good. Not only have we registered an extraordinary
increase in the number of pulsars detected in gamma rays, but we have also
witnessed the birth of new sub-families: first of all, the radio-quiet gamma
pulsars and later an ever growing number of millisecond pulsars, a real
surprise. We started with a sample of 7 gamma-ray emitting neutron stars (6
radio pulsars and Geminga) and now the Fermi-LAT harvest encompasses 24
"Geminga-like" new gamma-ray pulsars, a dozen millisecond pulsars and about
thirty radio pulsars. Moreover, radio searches targeted to LAT unidentified
sources yielded 18 new radio millisecond pulsars, several of which have been
already detected also in gamma rays. Thus, currently the family of gamma-ray
emitting neutron stars seems to be evenly divided between classical radio
pulsars, millisecond pulsars and radio quiet neutron stars.Comment: High Time Resolution Astrophysics IV - The Era of Extremely Large
Telescopes-HTRA-IV Agios Nikolaos, Crete, Greece May 5-7 2010 to be published
in Po
Timing for treatment of HCV recurrence after liver transplantation: the earlier the better.
HCV is the leading cause of death from liver disease and is the most common indication for a liver transplantation. Although HCV is a widespread health problem, disease management is particularly challenging in several key subpopulations, including liver transplant recipients. HCV recurrence after liver transplantation constituted a major challenge for the physicians during the last years. The recommended standard of care before the advent of new regimen was the treatment of confirmed recurrent disease, based either on persistent, unexplained elevated alanine aminotransferase levels or on histologically confirmed fibrosis, once rejection, biliary obstruction, and vascular damage have been ruled out. Moreover, early therapy (including interferon) has been associated with high rates of adverse effects, an increased risk of graft rejection, and higher proportions of patients requiring dose reductions. We are now facing a "new era" of direct antiviral agents that is already changing the approach to HCV burden in the post liver transplantation setting. Available data on treatment of HCV recurrence with the new antiviral drugs showed sustained virological response that ranges between 60 to 100%. In this comment we have focused on both the utility of non invasive test to evaluate the fibrosis progression and on timing of antiviral therapy for HCV recurrence. This article is protected by copyright. All rights reserved
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Towards a Wearer-Centred Framework for Animal Biotelemetry
The emerging discipline of Animal-Computer Interaction (ACI) aims to understand the relation between animals and technology in naturalistic settings, to design technology that can support animals in different contexts and to develop user-centred research methods and frameworks that enable animals to take part in the design process as legitimate contributors [11]. Given existing interspecies differences and communication barriers, measuring the behaviour of animals involved in ACI research can be instrumental to achieving any or all of these aims, as a way of gauging the animals’ patterns, needs and preferences. Indeed, measuring behaviour is a common practice among ACI researchers, who take various approaches to this task [5,15,17,24]. In this respect, the use of biotelemetry devices such as VHF tags and GPS trackers, or bio-logging and environmental sensors has a significant potential [22].
At the same time, biotelemetry has been used for many years in many areas of biological research. Biotelemetry is used to improve the quality of physiological and behavioural data collected from animals and in an attempt to reduce researchers’ intrusion in the animals’ habitat [2]. However, there is evidence that carrying biotelemetry tags may influence the bearer’s physiology and behaviour [20]. Such impacts interfere with the validity of recorded data [14] and the welfare of individual animal wearers [1,3,13]. Neither of these effects are compatible with the animal-centred perspective advocated by ACI, on both scientific and ethical grounds. Our analysis of current body-attached device design and biotelemetry-enabled studies points to a general lack of wearer-centred perspective. To address these issues, we have developed a framework to inform the design of wearer-centred biotelemetry interventions, in order to support the implementation of animal-centred research methodologies and design solutions in ACI and other disciplines
The Gribov problem in Noncommutative QED
It is shown that in the noncommutative version of QED (NCQED) Gribov copies
induced by the noncommutativity of space-time appear in the Landau gauge. This
is a genuine effect of noncommutative geometry which disappears when the
noncommutative parameter vanishes.Comment: 19 pages, 3 figures. Published. The paper has been shortened and many
references have been judged unnecessary or not suitable during the reviewing
proces
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