Longevity in Afrikaner Cattle: A Survival Analysis

The Afrikaner breed of cattle is indigenous to South Africa and due to their hardiness was once the most popular breed amongst farmers. The objectives for this study were to: (1) estimate environmental effects (age at first calving, season) and (2) genetic variance affecting longevity in Afrikaner cattle using survival analysis and a Weibull model and (3) evaluate the effect of the Infusion Project on longevity utilizing a Cox model. For the first objective, age at first calving impacted longevity as younger age at first calving was associated with decreased longevity. Season of birth and year of birth also impacted longevity. For the second objective, longevity in Afrikaner cattle was lowly heritable although sufficient breeding value variation was uncovered to justify selection for this trait. For the third objective, the Infusion Project was developed to target shortcomings of the Afrikaner breed with the introgression of Bonsmara alleles into Afrikaner cattle. The first backcross generation (BC1) and the initial Afrikaner-Bonsmara cross generation (F1) had greater longevity. The second (BC2) backcross generation did not differ in longevity relative to the purebreds (P ≥ 0.05). Infusion of Bonsmara germplasm increased longevity of the hybrid females, in the short-term

Alcohol consumption as a risk factor for sarcopenia - a meta-analysis

BACKGROUND: Sarcopenia, a loss of muscle strength and mass, has serious implications for older adults. Some risk factors for sarcopenia are well established. The role of other factors such as alcohol consumption is less certain. The main aim of this study was to explore the relationship between sarcopenia and alcohol consumption in people over 65 years old. METHODS: Four electronic databases were searched to identify potentially relevant papers. Demographics and information on sarcopenia and alcohol consumption were extracted from relevant papers. The relationship between sarcopenia and alcohol consumption was described using odds ratios (ORs). RESULTS: Of 214 papers identified as potentially relevant, 13 were ultimately included in the meta-analyses. The papers provided data from 13,155 participants. The OR (95 % CI) for sarcopenia among alcohol drinkers was 0.67 (0.54–0.83) for males, 0.89 (0.73–1.08) for females, and 0.77 (0.67–0.88) for the overall population. CONCLUSIONS: The results of this meta-analysis do not support alcohol consumption as a risk factor for sarcopenia

The Nature and Frequency of the Gas Outbursts in Comet 67P/Churyumov-Gerasimenko observed by the Alice Far-ultraviolet Spectrograph on Rosetta

Alice is a far-ultraviolet imaging spectrograph onboard Rosetta that, amongst multiple objectives, is designed to observe emissions from various atomic and molecular species from within the coma of comet 67P/Churyumov-Gerasimenko. The initial observations, made following orbit insertion in August 2014, showed emissions of atomic hydrogen and oxygen spatially localized close to the nucleus and attributed to photoelectron impact dissociation of H2O vapor. Weaker emissions from atomic carbon were subsequently detected and also attributed to electron impact dissociation, of CO2, the relative H I and C I line intensities reflecting the variation of CO2 to H2O column abundance along the line-of-sight through the coma. Beginning in mid-April 2015, Alice sporadically observed a number of outbursts above the sunward limb characterized by sudden increases in the atomic emissions, particularly the semi-forbidden O I 1356 multiplet, over a period of 10-30 minutes, without a corresponding enhancement in long wavelength solar reflected light characteristic of dust production. A large increase in the brightness ratio O I 1356/O I 1304 suggests O2 as the principal source of the additional gas. These outbursts do not correlate with any of the visible images of outbursts taken with either OSIRIS or the navigation camera. Beginning in June 2015 the nature of the Alice spectrum changed considerably with CO Fourth Positive band emission observed continuously, varying with pointing but otherwise fairly constant in time. However, CO does not appear to be a major driver of any of the observed outbursts.Comment: 6 pages, 4 figures, accepted for publication in the Astrophysical Journal Letter

Ultraviolet and visible photometry of asteroid (21) Lutetia using the Hubble Space Telescope

The asteroid (21) Lutetia is the target of a planned close encounter by the Rosetta spacecraft in July 2010. To prepare for that flyby, Lutetia has been extensively observed by a variety of astronomical facilities. We used the Hubble Space Telescope (HST) to determine the albedo of Lutetia over a wide wavelength range, extending from ~150 nm to ~700 nm. Using data from a variety of HST filters and a ground-based visible light spectrum, we employed synthetic photometry techniques to derive absolute fluxes for Lutetia. New results from ground-based measurements of Lutetia's size and shape were used to convert the absolute fluxes into albedos. We present our best model for the spectral energy distribution of Lutetia over the wavelength range 120-800 nm. There appears to be a steep drop in the albedo (by a factor of ~2) for wavelengths shorter than ~300 nm. Nevertheless, the far ultraviolet albedo of Lutetia (~10%) is considerably larger than that of typical C-chondrite material (~4%). The geometric albedo at 550 nm is 16.5 +/- 1%. Lutetia's reflectivity is not consistent with a metal-dominated surface at infrared or radar wavelengths, and its albedo at all wavelengths (UV-visibile-IR-radar) is larger than observed for typical primitive, chondritic material. We derive a relatively high FUV albedo of ~10%, a result that will be tested by observations with the Alice spectrograph during the Rosetta flyby of Lutetia in July 2010.Comment: 14 pages, 2 tables, 8 figure

Weakening of Jupiter's main auroral emission during January 2014

In January 2014 Jupiter's FUV main auroral oval decreased its emitted power by 70% and shifted equatorward by ∼1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in auroral current density rather than electron energy. This could be caused by a decrease in the source electron density, an order of magnitude increase in the source electron thermal energy, or a combination of these. Both can be explained either by expansion of the magnetosphere or by an increase in the inward transport of hot plasma through the middle magnetosphere and its interchange with cold flux tubes moving outward. In the latter case the hot plasma could have increased the electron temperature in the source region and produced the intense, low-latitude features, while the increased cold plasma transport rate produced the shift of the main oval