Genetics of heifer puberty and growth in tropically adapted beef breeds

Heifer reproductive performance is a driving factor for profitability in northern beef systems. Age at puberty (AP) directly influences conception rates and is a highly heritable early-in-life trait for the genetic improvement of female reproduction (Johnston et al. 2009). The research showed selection could occur with few major antagonisms with production traits. Recognising the relationship between AP and growth traits during sire selection has the potential to achieve desirable mating weights of pubertal heifers. The aim of this paper was to investigate the genetic relationship between age at puberty, weight at puberty (WP), and 600-day weight (600 dW) through use of sire EBVs

Class dealignment and the neighbourhood effect: Miller revisited

The concept of a neighbourhood effect within British voting patterns has largely been discarded, because no data have been available for testing it at the appropriate spatial scales. To undertake such tests, bespoke neighbourhoods have been created around the home of each respondent to the 1997 British Election Study survey in England and Wales, and small-area census data have been assembled for these to depict the socio-economic characteristics of voters' local contexts. Analyses of voting in these small areas, divided into five equal-sized status areas, provides very strong evidence that members of each social class were much more likely to vote Labour than Conservative in the low-status than in the high-status areas. This is entirely consistent with the concept of the neighbourhood effect, but alternative explanations are feasible. The data provide very strong evidence of micro-geographical variations in voting patterns, for which further research is necessary to identify the processes involved

Higher water temperature leads to precocious maturation of western rock lobsters (Panulirus cygnus), but are things that simple?

During a rock lobster post-puerulus grow out project, western rock lobsters from three different cohorts (post-puerulus, year-1 and year-2) were held for 12 months under two temperature regimes (ambient and 23oC) and two feed delivery treatments (the same ration of pelleted diet fed once nightly and in the alternate treatment, thrice nightly). At the end of the trial, 43% of females from the largest cohort (2-year post settlement) in the 23oC treatment, had ovigerous setae. However, none of the animals held at ambient temperatures showed signs of maturity. Feed delivery did not influence the presence or absence of ovigerous setae. Male maturity responded to elevated temperature in the same way as for females, as indicated by merus/carapace length ratios. The response of female size at maturity to 23oC was compared to a similar trial in the 1970s in which 2-year post settlement animals wereheld at 25oC. Maturity of females in that study was one year later than in the trial reported here, indicating that there may have been a decrease in age at maturity since the 1970s. The conclusion from this and research on other rock lobster species, is that size/age at maturity is likely to be a complex response to a range of contributing factors of which temperature is an important one

The Magnetic Field of the Solar Corona from Pulsar Observations

We present a novel experiment with the capacity to independently measure both the electron density and the magnetic field of the solar corona. We achieve this through measurement of the excess Faraday rotation due to propagation of the polarised emission from a number of pulsars through the magnetic field of the solar corona. This method yields independent measures of the integrated electron density, via dispersion of the pulsed signal and the magnetic field, via the amount of Faraday rotation. In principle this allows the determination of the integrated magnetic field through the solar corona along many lines of sight without any assumptions regarding the electron density distribution. We present a detection of an increase in the rotation measure of the pulsar J1801$-$2304 of approximately 160 \rad at an elongation of 0.95$^\circ$ from the centre of the solar disk. This corresponds to a lower limit of the magnetic field strength along this line of sight of $> 393\mu\mathrm{G}$. The lack of precision in the integrated electron density measurement restricts this result to a limit, but application of coronal plasma models can further constrain this to approximately 20mG, along a path passing 2.5 solar radii from the solar limb. Which is consistent with predictions obtained using extensions to the Source Surface models published by Wilcox Solar ObservatoryComment: 16 pages, 4 figures (1 colour): Submitted to Solar Physic

The ground state of the two-leg Hubbard ladder: a density--matrix renormalization group study

We present density-matrix renormalization group results for the ground state properties of two-leg Hubbard ladders. The half-filled Hubbard ladder is an insulating spin-gapped system, exhibiting a crossover from a spin-liquid to a band-insulator as a function of the interchain hopping matrix element. When the system is doped, there is a parameter range in which the spin gap remains. In this phase, the doped holes form singlet pairs and the pair-field and the "$4 k_F$" density correlations associated with pair density fluctuations decay as power laws, while the "$2 k_F$" charge density wave correlations decay exponentially. We discuss the behavior of the exponents of the pairing and density correlations within this spin gapped phase. Additional one-band Luttinger liquid phases which occur in the large interband hopping regime are also discussed.Comment: 14 pages, 18 figures, uses Revtex with epsfig to include the figure

Respiratory viruses, symptoms, and inflammatory markers in acute exacerbations and stable chronic obstructive pulmonary disease

The effects of respiratory viral infection on the time course of chronic obstructive pulmonary disease (COPD) exacerbation were examined by monitoring changes in systemic inflammatory markers in stable COPD and at exacerbation. Eighty-three patients with COPD (mean [SD] age, 66.6 [7.1] yr, FEV1, 1.06 [0.61] L) recorded daily peak expiratory flow rate and any increases in respiratory symptoms. Nasal samples and blood were taken for respiratory virus detection by culture, polymerase chain reaction, and serology, and plasma fibrinogen and serum interleukin-6 (IL-6) were determined at stable baseline and exacerbation. Sixty-four percent of exacerbations were associated with a cold occurring up to 18 d before exacerbation. Seventy-seven viruses (39 [58.2%] rhinoviruses) were detected in 66 (39.2%) of 168 COPD exacerbations in 53 (64%) patients. Viral exacerbations were associated with frequent exacerbators, colds with increased dyspnea, a higher total symptom count at presentation, a longer median symptom recovery period of 13 d, and a tendency toward higher plasma fibrinogen and serum IL-6 levels. Non-respiratory syncytial virus (RSV) respiratory viruses were detected in 11 (16%), and RSV in 16 (23.5%), of 68 stable COPD patients, with RSV detection associated with higher inflammatory marker levels. Respiratory virus infections are associated with more severe and frequent exacerbations, and may cause chronic infection in COPD. Prevention and early treatment of viral infections may lead to a decreased exacerbation frequency and morbidity associated with COPD

Characterization of Au3+ species in Au/C catalysts for the hydrochlorination reaction of acetylene

A set of Au/C catalysts for the gas phase hydrochlorination of acetylene to vinyl chloride monomer were prepared using a range of strong acids as impregnating solvents and varying the preparation drying temperature. The most active catalyst is the material prepared using aqua regia as solvent with an intermediate drying temperature of 140 °C. The effects of the catalyst preparation parameters on the catalytic activity are examined using XPS and TPR as analytical tools. In particular, the use of thermal reduction methods allows the determination of kinetic parameters for the reduction of Au3+ to Au0 by means of H2. These data support the existence of a redox cycle between Au3+/Au0 when carbon is used as support

Measuring proper motions of isolated neutron stars with Chandra

The excellent spatial resolution of the Chandra observatory offers the unprecedented possibility to measure proper motions at X-ray wavelength with relatively high accuracy using as reference the background of extragalactic or remote galactic X-ray sources. We took advantage of this capability to constrain the proper motion of RX J0806.4-4123 and RX J0420.0-5022, two X-ray bright and radio quiet isolated neutron stars (INSs) discovered by ROSAT and lacking an optical counterpart. In this paper, we present results from a preliminary analysis from which we derive 2 sigma upper limits of 76 mas/yr and 138 mas/yr on the proper motions of RX J0806.4-4123 and RX J0420.0-5022 respectively. We use these values together with those of other ROSAT discovered INSs to constrain the origin, distance and evolutionary status of this particular group of objects. We find that the tangential velocities of radio quiet ROSAT neutron stars are probably consistent with those of 'normal' pulsars. Their distribution on the sky and, for those having accurate proper motion vectors, their possible birth places, all point to a local population, probably created in the part of the Gould Belt nearest to the earth.Comment: 8 pages, 3 figures, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zan