Explanation for Anomalous Shock Temperatures Measured by Neutron Resonance Spectroscopy

Neutron resonance spectrometry (NRS) has been used to measure the temperature inside Mo samples during shock loading. The temperatures obtained were significantly higher than predicted assuming ideal hydrodynamic loading. The effect of plastic flow and non-ideal projectile behavior were assessed. Plastic flow was calculated self-consistently with the shock jump conditions: this is necessary for a rigorous estimate of the locus of shock states accessible. Plastic flow was estimated to contribute a temperature rise of 53K compared with hydrodynamic flow. Simulations were performed of the operation of the explosively-driven projectile system used to induce the shock in the Mo sample. The simulations predicted that the projectile was significantly curved on impact, and still accelerating. The resulting spatial variations in load, including radial components of velocity, were predicted to increase the apparent temperature that would be deduced from the width of the neutron resonance by 160K. These corrections are sufficient to reconcile the apparent temperatures deduced using NRS with the accepted properties of Mo, in particular its equation of state.Comment: near-final version, waiting for final consent from an autho

The trade-off between accuracy and accessibility of syphilis screening assays.

The availability of rapid and sensitive methods to diagnose syphilis facilitates screening of pregnant women, which is one of the most cost-effective health interventions available. We have evaluated two screening methods in Tanzania: an enzyme immunoassay (EIA), and a point-of-care test (POCT). We evaluated the performance of each test against the Treponema pallidum particle agglutination assay (TPPA) as the reference method, and the accessibility of testing in a rural district of Tanzania. The POCT was performed in the clinic on whole blood, while the other assays were performed on plasma in the laboratory. Samples were also tested by the rapid plasma Reagin (RPR) test. With TPPA as reference assay, the sensitivity and specificity of EIA were 95.3% and 97.8%, and of the POCT were 59.6% and 99.4% respectively. The sensitivity of the POCT and EIA for active syphilis cases (TPPA positive and RPR titer ≥ 1/8) were 82% and 100% respectively. Only 15% of antenatal clinic attenders in this district visited a health facility with a laboratory capable of performing the EIA. Although it is less sensitive than EIA, its greater accessibility, and the fact that treatment can be given on the same day, means that the use of POCT would result in a higher proportion of women with syphilis receiving treatment than with the EIA in this district of Tanzania

Exploratory Investigation into the Durability of Beneficial Cold Worked Fastener Hole in Aluminum

Cold working fastener holes in aluminum alloys is a widely used technique in the aerospace industry for improving the fatigue performance of structures. A compressive tangential stress introduced in the material during the cold working of the hole reduces the natural tendency of the material to crack at the holes under cyclic tensile loading. It is a lucrative technique for the aerospace industry in that it provides an increase in performance without any weight cost

Comparative Analysis of Heart Rate Variability Between Traditional Sets and Rest Redistribution

Resistance exercise methods have different effects on the cardiovascular system. During skeletal muscular contraction, heart rate increases while heart rate variability (HRV) decreases. HRV is thought to represent the complex interaction between the sympathetic and parasympathetic branches of the autonomic nervous system. PURPOSE: This study analyzed heart rate variability during two methods of resistance exercise, traditional sets (TS) and rest redistribution sets (RR), both containing the same volume and total rest time. METHODS: Twenty-five participants (Mean ± SD: Age= 22.4 ± 3.7 y.; height = 167.5 ± 9.7 cm; body mass = 72.7 ± 14.7 kg) completed 40 repetitions of the barbell squat with 65% 1RM load. Participants completed TS (4 sets of 10 repetitions, 3-minute rest) and RR (10 sets of 4 repetitions, 1-minute rest), in a randomized order on separate days. HRV was collected from each participant using a heart rate monitor. The HRV was analyzed using a specialized software. Average windows were developed to calculate the root mean square of successive differences (RMSSD) between normal heartbeats and stress index (SI) at rest, during the exercise session, and during recovery. Log transformation was performed in the case of a violation of the normality assumption. Paired t-tests were used to compare RMSSD and SI responses at initial rest, during exercise and recovery between TS and RR. RESULTS: During the initial rest period, there were no statistical differences between RR and TS in RMSSD (p=0.36; 7.85 ± 44.2 vs. 9.14 ± 6.63, respectively or SI (p=0.81; 3.50 ± 0.43 vs. 3.41 ±0.60, respectively). However, there were statistical significance for both RMSSD (pCONCLUSION: While the vagal response does not seem to be affected by training method during recovery, stress responses were higher during RR than TS exercise, as measured by HRV. Future studies can examine HRV behavior during exercise and establish its relationship to other physiological and perceptual markers

Distribution of the Southeastern Shrew (Sorex longirostris longirostris) in Arkansas

The southeastern shrew (Sorex longirostris longirostris) is considered uncommon and, due to a lack of knowledge, a Species of Greatest Conservation Need in Arkansas. Also, eastern Arkansas may represent a gap in the species’ distribution. Therefore, we evaluated persistence at previous capture sites, surveyed additional counties, quantified microhabitat at our capture locations, and compiled occurrences. Since Sealander and Heidt’s (1990) Arkansas Mammals detailed its occurrence, additional captures by Huston and Nelson (1994), Showen (2006), and this study document new counties (Pope and Searcy) and a new ecoregion (Arkansas Valley). Number of specimens in Arkansas has increased to 17 in 11 counties within the Ozark Highlands, Boston Mountains, Ouachita Mountains, and Arkansas Valley Ecoregions. Our efforts to assess a potential distribution gap within the Mississippi Alluvial Plain produced only specimens of other shrew species; therefore, possible factors affecting connectivity across the Mississippi Alluvial Plain and river basin are discussed. Given sparse records in Arkansas, uncommon and Species of Greatest Conservation Need designations are warranted for the southeastern shrew