EXPECTED PHENOTYPIC RESPONSE IN WEANING WEIGHT OF BEEF CALVES FROM SELECTION FOR DIRECT AND MATERNAL GENETIC EFFECTS

An equation is derived to predict expected phenotypic response to selection when the trait under selection is influenced by both direct and maternal genetic effects. The expected phenotypic response after the i+lth generation of selection is Pi+1 = (i+l){Delta}D + i{Delta}M + {Delta}MC where {Delta}D and {Delta}M are the averages of the genetic selection differentials of the parents for the direct and maternal effects and {Delta}MC is the maternal genetic selection differential for selected females. An example, corresponding to published reports of genetic variances and covariance for direct and maternal effects on weaning weight, illustrates the importance of the covariance term in long term response. With a large negative covariance, selection of males for direct and females for maternal genetic value would give greater expected response in progeny after the first generation than selection of females for direct genetic value

Stratigraphic Column of the Kope and Fairview Formations, Kentucky 445, Brent, Kentucky

The Upper Ordovician Kope Formation is exposed over a broad area of southwestern Ohio, southeastern Indiana, and northern Kentucky (Weir and others, 1984). Roadcuts along Ky. 445 near Brent (Figs. 2-3) and adjacent roadcuts along Interstate 275 expose a nearly complete section of the Kope Formation as well as the overlying Fairview Formation

The net exchange of methane with high Arctic landscapes during the summer growing season

High Arctic landscapes are essentially vast cold deserts interspersed with streams, ponds and wetlands. These landscapes may be important consumers and sources of the greenhouse gas methane (CH4), though few measurements exist from this region. To quantify the flux of CH4 (FCH4 ) between the atmosphere and high Arctic landscapes on northern Ellesmere Island, Canada, we made static chamber measurements over five and three growing seasons at a desert and wetland, respectively, and eddy covariance (EC) measurements at a wetland in 2012. Chamber measurements revealed that, during the growing season, desert soils consumed CH4 (-1.37±0.06 mg-CH4 m-2 d-1), whereas the wetland margin emitted CH4 (+0.22±0.14 mg-CH4 m-2 d-1). Desert CH4 consumption rates were positively associated with soil temperature among years, and were similar to temperate locations, likely because of suitable landscape conditions for soil gas diffusion. Wetland FCH 4 varied closely with stream discharge entering the wetland and hence e

Egg Quality Assurance Programs and Egg-associated Salmonella Enteritidis Infections, United States

A 1% increase in eggs produced under egg quality assurance programs was associated with a 0.14% decrease in Salmonella Enteritidis incidence

The Onfp Class in the Magellanic Clouds

The Onfp class of rotationally broadened, hot spectra was defined some time ago in the Galaxy, where its membership to date numbers only eight. The principal defining characteristic is a broad, centrally reversed He II $\lambda$4686 emission profile; other emission and absorption lines are also rotationally broadened. Recent surveys in the Magellanic Clouds (MCs) have brought the class membership there, including some related spectra, to 28. We present a survey of the spectral morphology and rotational velocities, as a first step toward elucidating the nature of this class. Evolved, rapidly rotating hot stars are not expected theoretically, because the stellar winds should brake the rotation. Luminosity classification of these spectra is not possible, because the principal criterion (He II $\lambda$4686) is peculiar; however, the MCs provide reliable absolute magnitudes, which show that they span the entire range from dwarfs to supergiants. The Onfp line-broadening distribution is distinct and shifted toward larger values from those of normal O dwarfs and supergiants with >99.99% confidence. All cases with multiple observations show line-profile variations, which even remove some objects from the class temporarily. Some of them are spectroscopic binaries; it is possible that the peculiar profiles may have multiple causes among different objects. The origin and future of these stars are intriguing; for instance, they could be stellar mergers and/or gamma-ray-burst progenitors.Comment: 27 pages, 8 figures, 2 tables; AJ accepte

A 2.3-Day Periodic Variability in the Apparently Single Wolf-Rayet Star WR 134: Collapsed Companion or Rotational Modulation?

We present the results of an intensive campaign of spectroscopic and photometric monitoring of the peculiar Wolf-Rayet star WR 134 from 1989 to 1997. This unprecedentedly large data set allows us to confirm unambiguously the existence of a coherent 2.25 +/- 0.05 day periodicity in the line-profile changes of He II 4686, although the global pattern of variability is different from one epoch to another. This period is only marginally detected in the photometric data set. Assuming the 2.25 day periodic variability to be induced by orbital motion of a collapsed companion, we develop a simple model aiming at investigating (i) the effect of this strongly ionizing, accreting companion on the Wolf-Rayet wind structure, and (ii) the expected emergent X-ray luminosity. We argue that the predicted and observed X-ray fluxes can only be matched if the accretion on the collapsed star is significantly inhibited. Additionally, we performed simulations of line-profile variations caused by the orbital revolution of a localized, strongly ionized wind cavity surrounding the X-ray source. A reasonable fit is achieved between the observed and modeled phase-dependent line profiles of He II 4686. However, the derived size of the photoionized zone substantially exceeds our expectations, given the observed low-level X-ray flux. Alternatively, we explore rotational modulation of a persistent, largely anisotropic outflow as the origin of the observed cyclical variability. Although qualitative, this hypothesis leads to greater consistency with the observations.Comment: 34 pages, 16 figures. Accepted by the Astrophysical Journa

Evolution of the geomagnetic daily variation at Tatuoca, Brazil, from 1957 to 2019: a transition from Sq to EEJ

The magnetic equator in the Brazilian region has moved over 1,100 km northward since 1957, passing the geomagnetic observatory Tatuoca (TTB), in northern Brazil, around 2013. We recovered and processed TTB hourly mean values of the geomagnetic field horizontal (H) component from 1957 until 2019, allowing the investigation of long‐term changes in the daily variation due to the influence of secular variation, solar activity, season, and lunar phase. The H day‐to‐day variability and the occurrence of the counter electrojet at TTB were also investigated. Until the 1990s, ionospheric solar quiet currents dominated the quiet‐time daily variation at TTB. After 2000, the magnitude of the daily variation became appreciably greater due to the equatorial electrojet (EEJ) contribution. The H seasonal and day‐to‐day variability increased as the magnetic equator approached, but their amplitudes normalized to the average daily variation remained at similar levels. Meanwhile, the amplitude of the lunar variation, normalized in the same way, increased from 5% to 12%. Within the EEJ region, the occurrence rate of the morning counter electrojet (MCEJ) increased with proximity to the magnetic equator, while the afternoon counter electrojet (ACEJ) did not. EEJ currents derived from CHAMP and Swarm satellite data revealed that the MCEJ rate varies with magnetic latitude within the EEJ region while the ACEJ rate is largely constant. Simulations with the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model based on different geomagnetic main field configurations suggest that long‐term changes in the geomagnetic daily variation at TTB can be attributed to the main field secular variation

A Spectroscopic Survey of WNL Stars in the LMC: General Properties and Binary Status

We report the results of an intense, spectroscopic survey of all 41 late-type, nitrogen-rich Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) observable with ground-based telescopes. This survey concludes the decade-long effort of the Montr\'eal Massive Star Group to monitor every known WR star in the Magellanic Clouds except for the 6 crowded WNL stars in R136, which will be discussed elsewhere. The focus of our survey was to monitor the so-called WNL stars for radial-velocity (RV) variability in order to identify the short- to intermediate-period (P \la 200 days) binaries among them. Our results are in line with results of previous studies of other WR subtypes, and show that the binary frequency among LMC WNL stars is statistically consistent with that of WNL stars in the Milky Way. We have identified four previously unknown binaries, bringing the total number of known WNL binaries in the LMC to nine. Since it is very likely that none but one of the binaries are classical, helium-burning WNL stars, but rather superluminous, hence extremely massive, hydrogen-burning objects, our study has dramatically increased the number of known binaries harbouring such objects, and thus paved the way to determine their masses through model-independent, Keplerian orbits. It is expected that some of the stars in our binaries will be among the most massive known. With the binary status of each WR star now known, we also studied the photometric and X-ray properties of our program stars using archival MACHO photometry as well as Chandra and ROSAT data. We find that one of our presumably single WNL stars is among the X-ray brightest WR sources known. We also identify a binary candidate from its RV variability and X-ray luminosity which harbours the most luminous WR star known in the Local Group.Comment: 25 pages, 11 figures; accepted for MNRA

SN 2011hw: Helium-Rich Circumstellar Gas and the Luminous Blue Variable to Wolf-Rayet Transition in Supernova Progenitors

We present optical photometry and spectroscopy of the peculiar Type IIn/Ibn supernova SN2011hw. Its light curve exhibits a slower decline rate than normal SNeIbc, with a peak absolute magnitude of -19.5 (unfiltered) and a secondary peak of -18.3 mag (R). Spectra of SN2011hw are unusual compared to normal SN types, most closely resembling the spectra of SNeIbn. We center our analysis on comparing SN 2011hw to the well-studied TypeIbn SN2006jc. While the two SNe have many important similarities, the differences are quite telling: compared to SN2006jc, SN2011hw has weaker HeI and CaII lines and relatively stronger H lines, its light curve has a higher luminosity and slower decline rate, and emission lines associated with the progenitor's CSM are narrower. One can reproduce the unusual continuum shape of SN2011hw with equal contributions of a 6000K blackbody and a spectrum of SN2006jc. We attribute this emission component and many other differences between the two SNe to extra opacity from a small amount of additional H in SN2011hw, analogous to the small H mass that makes SNeIIb differ from SNeIb. Slower speeds in the CSM and elevated H content suggest a connection between the progenitor of SN2011hw and the class of Ofpe/WN9 stars, which have been associated with LBVs in their hot quiescent phases between outbursts, and are H-poor - but not H-free like classical Wolf-Rayet (WR) stars. We conclude that the similarities and differences between SN2011hw and SN2006jc can be largely understood if their progenitors exploded at different points in the transitional evolution from an LBV to a WR star.Comment: 11 pages, 7 figures, submitted to MNRA