405 research outputs found
Vitamin A deficiency impairs contextual fear memory in rats: abnormalities in glucocorticoid pathway
Observations and fine-scale model simulations of gravity waves over Davis, East Antarctica (69°S, 78°E)
Large vertical velocities were observed throughout the troposphere at Davis, East Antarctica, on 18 February 2014 by a VHF wind-profiling radar. Simulations using the Met Office Unified Model at 2.2, 0.5, and 0.1 km horizontal grid spacing were able to broadly capture the location, timing, and magnitude of the observed velocities, as well as reveal that they are due to small-scale orographic gravity waves resulting from the interaction between the coastal topography and strong easterly winds associated with a synoptic-scale cyclone situated to the north. The simulations indicated that the gravity waves are responsible for (i) temperature fluctuations which coincided with satellite-observed cloud variations in the vicinity of Davis, suggesting that they have a crucial role in the formation of cirrus clouds, and (ii) large vertical momentum fluxes in the troposphere. The waves are prevented from propagating into the stratosphere by the background winds turning from near-surface easterlies to lower stratospheric northerlies. As well as illuminating and quantifying the role that weather systems have in producing orographic gravity waves along the East Antarctic coastline, studies such as this should be exploited to improve the representation of key localized atmospheric processes in global climate models
Effectiveness of adjuvant FOLFOX vs 5FU/LV in adults over age 65 with stage II and III colon cancer using a novel hybrid approach
Purpose: Estimates of cancer therapy effects can differ in clinical trials and clinical practice, partly due to underrepresentation of certain patient subgroups in trials. We utilize a hybrid approach, combining clinical trial and real-world data, to estimate the comparative effectiveness of two adjuvant chemotherapy regimens for colon cancer. Methods: We identified patients aged 66 and older enrolled in the Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer. Similar patients were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, initiating adjuvant chemotherapy with either 5-fluorouracil (5FU) alone or in combination with oxaliplatin (FOLFOX). We used logistic regression to estimate the likelihood of trial enrollment as a function of age, sex, and substage. Using inverse odds of sampling weights (IOSW), we compared 5-year mortality in patients randomized to FOLFOX vs 5FU using weighted Cox proportional hazards regression, the Nelson-Aalen estimator for cumulative hazards, and bootstrapping for 95% confidence intervals (CIs). Results: There were 690 trial participants and 3834 SEER-Medicare patients. The SEER-Medicare population was older and had a higher proportion of stage IIIB and IIIC patients than the trial. After controlling for differences between populations, the IOSW 5-year HR was 1.21 (0.89, 1.65), slightly farther from the null than the trial estimate (HR = 1.14, 95%CI: 0.87, 1.49). Conclusions: This study supports mounting evidence of little to no incremental reduction in 5-year mortality for FOLFOX vs 5FU in older adults with stage II-III colon cancer, emphasizing the importance of combining clinical trial and real-world data to support such conclusions
Quantification of 11β-hydroxysteroid dehydrogenase 1 kinetics and pharmacodynamic effects of inhibitors in brain using mass spectrometry imaging and stable-isotope tracers in mice
Hydrocarbon-based statistical copolymers outperform block copolymers for stabilization of ethanol–water Foams
Well-defined block copolymers have been widely used as emulsifiers, stabilizers, and dispersants in the chemical industry for at least 50 years. In contrast, nature employs amphiphilic proteins as polymeric surfactants whereby the spatial distribution of hydrophilic and hydrophobic amino acids within the polypeptide chains is optimized for surface activity. Herein, we report that polydisperse statistical copolymers prepared by conventional free-radical copolymerization can provide superior foaming performance compared to the analogous diblock copolymers. A series of predominantly (meth)acrylic comonomers are screened to identify optimal surface activity for foam stabilization of aqueous ethanol solutions. In particular, all-acrylic statistical copolymers comprising trimethylhexyl acrylate and poly(ethylene glycol) acrylate, P(TMHA-stat-PEGA), confer strong foamability and also lower the surface tension of a range of ethanol–water mixtures to a greater extent than the analogous block copolymers. For ethanol-rich hand sanitizer formulations, foam stabilization is normally achieved using environmentally persistent silicone-based copolymers or fluorinated surfactants. Herein, the best-performing fully hydrocarbon-based copolymer surfactants effectively stabilize ethanol-rich foams by a mechanism that resembles that of naturally-occurring proteins. This ability to reduce the surface tension of low-surface-energy liquids suggests a wide range of potential commercial applications
Influence of optimized lubrication-cooling and minimum quantity lubrication on the cutting forces, on the geometric quality of the surfaces and on the micro-structural integrity of hardened steel parts
Search for and Using Genetic Programming Event Selection
We apply a genetic programming technique to search for the double Cabibbo
suppressed decays and .
We normalize these decays to their Cabibbo favored partners and find
\Lambda_c^+ \to p K^+ \pi^-\Lambda_c^+ \to p K^-
\pi^+ and D_s^+ \to K^+ K^+
\pi^-D_s^+ \to K^+ K^- \pi^+ where
the first errors are statistical and the second are systematic. Expressed as
90% confidence levels (CL), we find and respectively.
This is the first successful use of genetic programming in a high energy
physics data analysis.Comment: 10 page
Measurement of the D+ and Ds+ decays into K+K-K+
We present the first clear observation of the doubly Cabibbo suppressed decay
D+ --> K-K+K+ and the first observation of the singly Cabibbo suppressed decay
Ds+ --> K-K+K+. These signals have been obtained by analyzing the high
statistics sample of photoproduced charm particles of the FOCUS(E831)
experiment at Fermilab. We measure the following relative branching ratios:
Gamma(D+ --> K-K+K+)/Gamma(D+ --> K-pi+pi+) = (9.49 +/- 2.17(statistical) +/-
0.22(systematic))x10^-4 and Gamma(Ds+ --> K-K+K+)/Gamma(Ds+ --> K-K+pi+) =
(8.95 +/- 2.12(statistical) +2.24(syst.) -2.31(syst.))x10^-3.Comment: 10 pages, 8 figure
A Non-parametric Approach to the D+ to K*0bar mu+ nu Form Factors
Using a large sample of D+ -> K- pi+ mu+ nu decays collected by the FOCUS
photoproduction experiment at Fermilab, we present the first measurements of
the helicity basis form factors free from the assumption of spectroscopic pole
dominance. We also present the first information on the form factor that
controls the s-wave interference discussed in a previous paper by the FOCUS
collaboration. We find reasonable agreement with the usual assumption of
spectroscopic pole dominance and measured form factor ratios.Comment: 14 pages, 5 figures, and 2 tables. We updated the previous version by
changing some words, removing one plot, and adding two tables. These changes
are mostly stylisti
Measurements of Branching Ratios
Using data collected by the fixed target Fermilab experiment FOCUS, we
measure the branching ratios of the Cabibbo favored decays , , and relative to to be
, , and ,
respectively. We report the first observation of the Cabibbo suppressed decay
and we measure the branching ratio relative to
to be . We also set 90%
confidence level upper limits for and relative to to
be 0.12 and 0.05, respectively. We find an indication of the decays and and set
90% confidence level upper limits for the branching ratios with respect to
to be 0.12 and 1.72, respectively. Finally, we
determine the 90% C.L. upper limit for the resonant contribution relative to to be 0.10.Comment: 14 pages, 8 figure
- …