3,018 research outputs found
Rare B Decays and B Decay Dynamics
I present some recent measurements of B meson decay rates to leptonic and
charmless hadronic final states, as well as of CP-violation charge asymmetries
and other features. I sketch the theoretical frameworks used to predict these,
and indicate the level of agreement of the estimates with experiment.Comment: Comments: 10 pages, 13 postscript figues, contributed to the
Proceedings of the XXV Physics in Collisio
Transit Timing Observations from Kepler: VI. Potentially interesting candidate systems from Fourier-based statistical tests
We analyze the deviations of transit times from a linear ephemeris for the
Kepler Objects of Interest (KOI) through Quarter six (Q6) of science data. We
conduct two statistical tests for all KOIs and a related statistical test for
all pairs of KOIs in multi-transiting systems. These tests identify several
systems which show potentially interesting transit timing variations (TTVs).
Strong TTV systems have been valuable for the confirmation of planets and their
mass measurements. Many of the systems identified in this study should prove
fruitful for detailed TTV studies.Comment: 32 pages, 6 of text and one long table, Accepted to Ap
Route of administration affects corticosteroid sensitivity of a combined ovalbumin and lipopolysaccharide model of asthma exacerbation in guinea-pigs
Lipopolysaccharide (LPS) contributes to asthma exacerbations and development of inhaled corticosteroid insensitivity. Complete resistance to systemic corticosteroids is rare and most patients lie on a continuum of steroid responsiveness. The objective of this study was to examine the sensitivity of combined ovalbumin- (Ova) and LPS-induced functional and inflammatory responses to inhaled and systemic corticosteroid in conscious guinea-pigs, to test the hypothesis that the route of administration affects its sensitivity. Guinea-pigs were sensitised to Ova and challenged with inhaled Ova alone or combined with LPS. Airways function was determined by measuring specific airways conductance via whole-body plethysmography. Airways hyperresponsiveness to histamine was determined pre- and 24h post-Ova challenge. Airways inflammation and underlying mechanisms were determined from bronchoalveolar lavage cell counts and lung tissue cytokines. Vehicle or dexamethasone was administered by once-daily intraperitoneal injection (5, 10 or 20 mg/kg) or twice-daily inhalation (4 or 20 mg/ml) for 6 days before Ova challenge or Ova with LPS. LPS exacerbated Ova-induced responses, elongating early asthmatic responses (EAR), prolonging bronchoconstriction by histamine and further elevating airways inflammation. Intraperitoneal dexamethasone (20 mg/kg) significantly reduced the elongated EAR and airways inflammation but not the increased bronchoconstriction to histamine. In contrast, inhaled dexamethasone (20 mg/ml), which inhibited responses to Ova alone, did not significantly reduce functional and inflammatory responses to combined Ova and LPS. Combined Ova and LPS-induced functional and inflammatory responses are insensitive to inhaled but only partially sensitive to systemic dexamethasone. These results suggest that the route of corticosteroid administration may be important in determining the sensitivity of asthmatic responses to these agents
Prognostic implications of left ventricular global longitudinal strain in heart failure patients with narrow QRS complex treated with cardiac resynchronization therapy: a subanalysis of the randomized EchoCRT trial
Aim:
Left ventricular (LV) global longitudinal strain (GLS) reflects LV systolic function and correlates inversely with the extent of LV myocardial scar and fibrosis. The present subanalysis of the Echocardiography Guided CRT trial investigated the prognostic value of LV GLS in patients with narrow QRS complex.
Methods and results:
Left ventricular (LV) global longitudinal strain (GLS) was measured on the apical 2-, 4- and 3-chamber views using speckle tracking analysis. Measurement of baseline LV GLS was feasible in 755 patients (374 with cardiac resynchronization therapy (CRT)-ON and 381 with CRT-OFF). The median value of LV GLS in the overall population was 7.9%, interquartile range 6.2–10.1%. After a mean follow-up period of 19.4 months, 95 patients in the CRT-OFF group and 111 in the CRT-ON group reached the combined primary endpoint of all-cause mortality and heart failure hospitalization. Each 1% absolute unit decrease in LV GLS was independently associated with 11% increase in the risk to reach the primary endpoint (Hazard ratio 1.11; 95% confidence interval 95% 1.04–1.17, P < 0.001), after adjusting for ischaemic cardiomyopathy and randomization treatment among other clinically relevant variables. When categorizing patients according to quartiles of LV GLS, the primary endpoint occurred more frequently in patients in the lowest quartile (<6.2%) treated with CRT-ON vs. CRT-OFF (45.6% vs. 28.7%, P = 0.009) whereas, no differences were observed in patients with LV GLS ≥6.2% treated with CRT-OFF vs. CRT-ON (23.7% vs. 24.5%, respectively; P  = 0.62).
Conclusion:
Low LV GLS is associated with poor outcome in heart failure patients with QRS width <130 ms, independent of randomization to CRT or not. Importantly, in the group of patients with the lowest LV GLS quartile, CRT may have a detrimental effect on clinical outcomes
Factors Influencing Sun Protection Behaviors among Patients with Skin Cancer: An Application of the Information-Motivation-Behavioral Skills Model
© 2019 by the Dermatology Nurses\u27 Association. This study aimed to assess predictors of sun protection behaviors based on the information-motivation-behavioral skills (IMB) model among people diagnosed with nonmelanoma skin cancer (NMSC). For this descriptive, cross-sectional study, a convenience sample of 311 patients with NMSC was recruited at a medical center in Mississippi. Patients were invited to complete a face- A nd content-valid, IMB-model-based questionnaire. The average age of the participants was 64.12 (±12.02) years, and most (58.8%) were male. Most participants indicated not using sun protection behaviors while outdoors. Findings showed that sun protection behaviors were directly predicted by self-efficacy (standardized path coefficient = 0.504, p \u3c.001) and social support (standardized path coefficient = 0.199, p =.010). In addition, sun protection behavior was indirectly predicted (through self-efficacy) by social support (standardized indirect effect = 0.160, p \u3c.001) and attitudes (standardized indirect effect = 0.192, p =.001). The explained variances for self-efficacy and sun protection behaviors were 43% and 35.4%, respectively. In conclusion, the IMB model appears to be a useful theoretical framework for predicting sun protection behaviors among patients with NMSC. Sun safety intervention programs should be developed based on this theoretical model for patients with NMSC
Design, Synthesis and Biological Evaluation of Aminoalkylindole Derivatives as Cannabinoid Receptor Ligands with Potential for Treatment of Alcohol Abuse
Attenuation of increased endocannabinoid signaling with a CB1R neutral antagonist might offer a new therapeutic direction for treatment of alcohol abuse. We have recently reported that a mono-hydroxylated metabolite of the synthetic aminoalkylindole cannabinoid JHW-073 (3) exhibits neutral antagonist activity at CB1Rs and thus may serve as a promising lead for the development of novel alcohol abuse therapies. In the current study, we show that systematic modification of an aminoalkylindole scaffold identified two new compounds with dual CB1R antagonist/CB2R agonist activity. Similar to the CB1R antagonist/inverse agonist rimonabant, analogues 27 and 30 decrease oral alcohol self-administration, without affecting total fluid intake and block the development of alcohol-conditioned place preference. Collectively, these initial findings suggest that design and systematic modification of aminoalkylindoles such as 3 may lead to development of novel cannabinoid ligands with dual CB1R antagonist/CB2R agonist activity with potential for use as treatments of alcohol abuse
Low False-Positive Rate of Kepler Candidates Estimated From A Combination Of Spitzer And Follow-Up Observations
(Abridged) NASA's Kepler mission has provided several thousand transiting
planet candidates, yet only a small subset have been confirmed as true planets.
Therefore, the most fundamental question about these candidates is the fraction
of bona fide planets. Estimating the rate of false positives of the overall
Kepler sample is necessary to derive the planet occurrence rate. We present the
results from two large observational campaigns that were conducted with the
Spitzer telescope during the the Kepler mission. These observations are
dedicated to estimating the false positive rate (FPR) amongst the Kepler
candidates. We select a sub-sample of 51 candidates, spanning wide ranges in
stellar, orbital and planetary parameter space, and we observe their transits
with Spitzer at 4.5 microns. We use these observations to measures the
candidate's transit depths and infrared magnitudes. A bandpass-dependent depth
alerts us to the potential presence of a blending star that could be the source
of the observed eclipse: a false-positive scenario. For most of the candidates
(85%), the transit depths measured with Kepler are consistent with the depths
measured with Spitzer as expected for planetary objects, while we find that the
most discrepant measurements are due to the presence of unresolved stars that
dilute the photometry. The Spitzer constraints on their own yield FPRs between
5-40%, depending on the KOIs. By considering the population of the Kepler field
stars, and by combining follow-up observations (imaging) when available, we
find that the overall FPR of our sample is low. The measured upper limit on the
FPR of our sample is 8.8% at a confidence level of 3 sigma. This observational
result, which uses the achromatic property of planetary transit signals that is
not investigated by the Kepler observations, provides an independent indication
that Kepler's false positive rate is low.Comment: 33 pages, 16 figures, 3 tables; accepted for publication in ApJ on
February 7, 201
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