40 research outputs found
Neutrino Telescopy in the Mediterranean Sea
The observation of high-energy extraterrestrial neutrinos is one of the most
promising future options to increase our knowledge on non-thermal processes in
the universe. Neutrinos are e.g. unavoidably produced in environments where
high-energy hadrons collide; in particular this almost certainly must be true
in the astrophysical accelerators of cosmic rays, which thus could be
identified unambiguously by sky observations in "neutrino light". On the one
hand, neutrinos are ideal messengers for astrophysical observations since they
are not deflected by electromagnetic fields and interact so weakly that they
are able to escape even from very dense production regions and traverse large
distances in the universe without attenuation. On the other hand, their weak
interaction poses a significant problem for detecting neutrinos. Huge target
masses up to gigatons must be employed, requiring to instrument natural
abundances of media such as sea water or antarctic ice. The first generation of
such neutrino telescopes is taking data or will do so in the near future, while
the second-generation projects with cubic-kilometre size is under construction
or being prepared. This report focuses on status and prospects of current
(ANTARES, NEMO, NESTOR) and future (KM3NeT) neutrino telescope projects in the
Mediterranean Sea.Comment: Presented at 27th Int. School on Nucl. Phys. (Neutrinos in Cosmology,
in Astro, Particle and Nuclear Physics), Erice/Italy, Sept. 2005; 8 pages, 7
figures. To appear in Prog. Part. Nucl. Phys. V2,V3: fixed incompatibilities
of postscript figures with the arXiv softwar
Earlier proteoglycan turnover promotes higher efficiency matrix remodeling in MRL/MpJ tendons
While most mammalian tissue regeneration is limited, the Murphy Roths Large (MRL/MpJ) mouse has been identified to regenerate several tissues, including tendon. Recent studies have indicated that this regenerative response is innate to the tendon tissue and not reliant on a systemic inflammatory response. Therefore, we hypothesized that MRL/MpJ mice may also exhibit a more robust homeostatic regulation of tendon structure in response to mechanical loading. To assess this, MRL/MpJ and C57BL/6J Flexor digitorum longus tendon explants were subjected to stress-deprived conditions in vitro for up to 14 days. Explant tendon health (metabolism, biosynthesis, and composition), matrix metalloproteinase activity, gene expression, and tendon biomechanics were assessed periodically. We found a more robust response to a loss of mechanical stimulus in the MRL/MpJ tendon explants, exhibiting an increase in collagen production and MMP activity consistent with previous in vivo studies. This greater collagen turnover was preceded by an early expression of small leucine rich proteoglycans and proteoglycan-degrading MMP-3, promoting efficient regulation and organization of newly synthesized collagen and allowing for more efficient overall turnover in MRL/MpJ tendons. Therefore, mechanisms of MRL/MpJ matrix homeostasis may be fundamentally different from that of B6 tendons and may indicate better recovery from mechanical microdamage in MRL/MpJ tendons. We demonstrate here the utility of the MRL/MpJ model in elucidating mechanisms of efficient matrix turnover and its potential to shed light on new targets for more effective treatments for degenerative matrix changes brought about by injury, disease, or aging. This article is protected by copyright. All rights reserved.NIH/National Institutes of Healt
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Enhancing the quality of international orthopedic medical mission trips using the blue distinction criteria for knee and hip replacement centers
Background: Several organizations seek to address the growing burden of arthritis in developing countries by providing total joint replacements (TJR) to patients with advanced arthritis who otherwise would not have access to these procedures. Because these mission trips operate in resource poor environments, some of the features typically associated with high quality care may be difficult to implement. In the U.S., many hospitals that perform TJRs use the Blue Cross/Shield’s Blue Distinction criteria as benchmarks of high quality care. Although these criteria were designed for use in the U.S., we applied them to Operation Walk (Op-Walk) Boston’s medical mission trip to the Dominican Republic. Evaluating the program using these criteria illustrated that the program provides high quality care and, more importantly, helped the program to find areas of improvement. Methods: We used the Blue Distinction criteria to determine if Op-Walk Boston achieves Blue Distinction. Each criterion was grouped according to the four categories included in the Blue Distinction criteria— “general and administrative”, “structure”, “process”, or “outcomes and volume”. Full points were given for criteria that the program replicates entirely and zero points were given for criteria that are not replicated entirely. Of the non-replicated criteria, Op-Walk Boston’s clinical and administrative teams were asked if they compensate for failure to meet the criterion, and they were also asked to identify barriers that prevent them from meeting the criterion. Results: Out of 100 possible points, the program received 71, exceeding the 60-point threshold needed to qualify as a Blue Distinction center. The program met five out of eight “required” criteria and 11 out of 19 “informational” criteria. It scored 14/27 in the “general” category, 30/36 in the “structure” category, 17/20 in the “process” category, and 10/17 in the “outcomes and volume” category. Conclusion: Op-Walk Boston qualified for Blue Distinction. Our analysis highlights areas of programmatic improvement and identifies targets for future quality improvement initiatives. Additionally, we note that many criteria can only be met by hospitals operating in the U.S. Future work should therefore focus on creating criteria that are applicable to TJR mission trips in the context of developing countries
Probing a Supersymmetric Model for Neutrino Masses at Ultrahigh Energy Neutrino Telescopes
A bilinear R-Parity breaking SUSY model for neutrino mass and mixing predicts
the lightest superparticle to decay mainly into a pair of tau leptons or b
quarks along with a neutrino for relatively light SUSY spectra. This leads to a
distinctive triple bang signature of SUSY events at ultrahigh energy neutrino
telescopes like IceCube or Antares. While the expected signal size is only
marginal at IceCube, it will be promising for a future multi-km^3 size neutrino
telescope.Comment: 11 pages pdf including 2 figures. Discussion added. Final version to
appear in Physics Letters