Efficient concepts for large erectable space structures

The status of Langley Research Center development of the nestable column concept is reviewed including results of member and truss component tests, and planned assembly studies. In addition, more recent studies of alternative member concepts are presented. Preliminary results on relative efficiency of several types of truss-type columns are compared and future test plans discussed

Sheep Production Guide

This publication provides various management practices to increase the productivity of the ewe flock. It discusses target dates, a timeline for early lambing, production records, lambing difficulties, and artificial rearing of lambs, as well as management of the flock, lambs, and wool

Adaptive Bayesian and frequentist data processing for quantum tomography

The outcome statistics of an informationally complete quantum measurement for a system in a given state can be used to evaluate the ensemble expectation of any linear operator in the same state, by averaging a function of the outcomes that depends on the specific operator. Here we introduce two novel data-processing strategies, non-linear in the frequencies, which lead to faster convergence to theoretical expectations.Comment: 12 pages, 2 figures, revised versio

Detection of impaired cerebral autoregulation improves by increasing arterial blood pressure variability

Although the assessment of dynamic cerebral autoregulation (CA) based on measurements of spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF) is a convenient and much used method, there remains uncertainty about its reliability. We tested the effects of increasing ABP variability, provoked by a modification of the thigh cuff method, on the ability of the autoregulation index to discriminate between normal and impaired CA, using hypercapnia as a surrogate for dynamic CA impairment. In 30 healthy volunteers, ABP (Finapres) and CBF velocity (CBFV, transcranial Doppler) were recorded at rest and during 5% CO(2) breathing, with and without pseudo-random sequence inflation and deflation of bilateral thigh cuffs. The application of thigh cuffs increased ABP and CBFV variabilities and was not associated with a distortion of the CBFV step response estimates for both normocapnic and hypercapnic conditions (P=0.59 and P=0.96, respectively). Sensitivity and specificity of CA impairment detection were improved with the thigh cuff method, with the area under the receiver-operator curve increasing from 0.746 to 0.859 (P=0.031). We conclude that the new method is a safe, efficient, and appealing alternative to currently existing assessment methods for the investigation of the status of CA

The Fitness Consequences Of Multiple‐Locus Heterozygosity: The Relationship Between Heterozygosity And Growth Rate In Pitch Pine (Pinus Rigida Mill.)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137487/1/evo05853.pd

The McGill score as a screening test for obstructive sleep disordered breathing in children with co-morbidities

Background: The McGill score is used to stratify severity of oximetry in children referred for investigation of obstructive sleep apnoea (OSA) to identify those with more severe disease and prioritize treatment. We hypothesized that its Positive predictive value (PPV) and Negative predictive value (NPV) in detecting OSA differs significantly between children with medical conditions and otherwise healthy children. / Methods: We performed a two-year retrospective analysis of children referred for investigation of OSA who underwent a cardiorespiratory (CR) polygraphy study. McGill score was calculated from the oximetry trace blinded to polygraphy results. We looked at 2 definitions of OSA: Obstructive Apnoea Hypopnoea Index (oAHI) ≥1 and ≥5. McGill sensitivity, specificity, PPV and NPV were calculated. McGill score=1 was considered normal or inconclusive, >1 abnormal. / Results: We studied 312 children, 190 males (61%), median age 4.5 (2.4-7.9) years. 129 were otherwise healthy and 183 had associated medical conditions. The PPV of the McGill score was significantly lower in children with medical conditions than otherwise healthy children. The NPV was similar in both groups of children. / Conclusions: The higher number of false positives in children with medical conditions may be due to non-obstructive causes such as central apnoeas. Children with underlying lung disease are also more likely to desaturate following a brief apnoea or hypopnoea. Children with co-morbidities who have an abnormal McGill score should not be assumed to have OSA and need more detailed sleep studies to determine the reason for the oxygen desaturations

Effects of Avoparcin on Performance of Feedlot Heifers

Avoparcin is a glycopeptide antibiotic produced by a strain of streptomyces candidus with activity against certain gram positive organisms. It has been reported to reduce the ratio of acetate to propionate produced during rumen fermentation and to improve weight gain and feed efficiency of feedlot cattle. This study was conducted to evaluate the effects of 30, 45 and 60 grams per ton of avoparcin and 30 grams per ton of monensin in the feed on weight gain, feed utilization and carcass quality of finishing heifers over a 140-day feeding period

Vitamin A Bioptency as Measured by Stores of Vitamin A in Livers of Feedlot Cattle

The objective of these experiments was to evaluate the biological potency of two sources of vitamin A premix differing in freshness when administered to fattening beef cattle. Chemical assays were compared with blood and liver vitamin A content to measure the biopotency of the vitamin

Measuring the Solar Radius from Space during the 2003 and 2006 Mercury Transits

The Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory observed the transits of Mercury on 2003 May 7 and 2006 November 8. Contact times between Mercury and the solar limb have been used since the 17th century to derive the Sun's size but this is the first time that high-quality imagery from space, above the Earth's atmosphere, has been available. Unlike other measurements this technique is largely independent of optical distortion. The true solar radius is still a matter of debate in the literature as measured differences of several tenths of an arcsecond (i.e., about 500 km) are apparent. This is due mainly to systematic errors from different instruments and observers since the claimed uncertainties for a single instrument are typically an order of magnitude smaller. From the MDI transit data we find the solar radius to be 960".12 +/- 0".09 (696,342 +/- 65 km). This value is consistent between the transits and consistent between different MDI focus settings after accounting for systematic effects.Comment: Accepted for publication in The Astrophysical Journal (2012 March 5