22 research outputs found
Risk of septic knee following retrograde intramedullary nailing of open and closed femur fractures
<p>Abstract</p> <p>Background</p> <p>One potential complication of retrograde femoral nailing in the treatment of femur fractures is the risk of septic knee. This risk theoretically increases in open fractures as a contaminated fracture site has the potential to seed the instrumentation being passed in and out of the sterile intraarticular starting point. There are few studies examining this potential complication in a relatively commonly practiced technique.</p> <p>Methods</p> <p>All patients who received a retrograde femoral nail for femur fracture between September 1996 and November 2006 at a Level 1 trauma center were retrospectively reviewed. This yielded 143 closed fractures, 38 open fractures and 4 closed fractures with an ipsilateral traumatic knee arthrotomy. Patient follow-up records were reviewed for documentation of septic knee via operative notes, wound culture or knee aspirate data, or the administration of antibiotics for suspected septic knee.</p> <p>Results</p> <p>No evidence of septic knee was found in the 185 fractures examined in the dataset. Utilizing the Wilson confidence interval, the rate of septic knee based on our population was no greater than 2%, with that of the open fracture group alone being 9%.</p> <p>Conclusions</p> <p>Based on these results and review of the literature, the risk of septic knee in retrograde femoral nailing of both open and closed femoral shaft fractures appears low but potentially not insignificant.</p> <p>Funding</p> <p>There was no outside source of funding from either industry or other organization for this study.</p
General Analysis of Antideuteron Searches for Dark Matter
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.Comment: 44 pages, 15 Figure
Precision Unification in \lambda SUSY with a 125 GeV Higgs
It is challenging to explain the tentative 125 GeV Higgs signal in the
Minimal Supersymmetric Standard Model (MSSM) without introducing excessive
fine-tuning, and this motivates the study of non-minimal implementations of low
energy supersymmetry (SUSY). A term \lambda SH_uH_d involving a Standard Model
(SM) singlet state S leads to an additional source for the quartic interaction
raising the mass of the lightest SM-like Higgs. However, in order to achieve
m_h \approx 125 GeV with light stops and small stop mixing, it is necessary for
\lambda \gtrsim 0.7 and consequently \lambda may become non-perturbative before
the unification scale. Moreover, as argued by Barbieri, Hall, et al. low
fine-tuning prefers the region \lambda~1-2, leading to new or non-perturbative
physics involving S below the GUT scale (`\lambda SUSY' models). This raises
the concern that precision gauge coupling unification, the prime piece of
indirect experimental evidence for low energy SUSY, may be upset. Using the
NSVZ exact \beta-function along with well motivated assumptions on the strong
coupling dynamics we show that this is not necessarily the case, but rather
there exist classes of UV completions where the strong-coupling effects can
naturally correct for the present ~3% discrepancy in the two-loop MSSM
unification prediction for \alpha_s. Moreover, we argue that in certain
scenarios a period of strong coupling can also be beneficial for t-b
unification, while maintaining the small to moderate values of tan\beta
preferred by the Higgs mass.Comment: 16 pages, 5 figures, v2. Discussion regarding evolution of Yukawa
couplings and t-b unification added, accepted for publication in JHE
Development of the PSYCHS: Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS
Aim: To harmonize two ascertainment and severity rating instruments commonly used for the clinical high risk syndrome for psychosis (CHR-P): the Structured Interview for Psychosis-risk Syndromes (SIPS) and the Comprehensive Assessment of At-Risk Mental States (CAARMS). Methods: The initial workshop is described in the companion report from Addington et al. After the workshop, lead experts for each instrument continued harmonizing attenuated positive symptoms and criteria for psychosis and CHR-P through an intensive series of joint videoconferences. Results: Full harmonization was achieved for attenuated positive symptom ratings and psychosis criteria, and modest harmonization for CHR-P criteria. The semi-structured interview, named Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS (PSYCHS), generates CHR-P criteria and severity scores for both CAARMS and SIPS. Conclusions: Using the PSYCHS for CHR-P ascertainment, conversion determination, and attenuated positive symptom severity rating will help in comparing findings across studies and in meta-analyses
Separation and Information Hiding
We investigate proof rules for information hiding, using the formalism of separation logic. In essence, we use the separating conjunction to partition the internal resources of a module from those accessed by the moduleâs clients. The use of a logical connective gives rise to a form of dynamic partitioning, where we track the transfer of ownership of portions of heap storage between program components. It also enables us to enforce separation in the presence of mutable data structures with embedded addresses that may be aliased