Temperature Induced Spin Density Wave in Magnetic Doped Topological Insulators

We study the magnetic properties of topological insulators doped with isoelectronic magnetic impurities. We obtain that at zero temperature the impurities order ferromagnetically, but when raising the temperature the topological insulator undergoes a first order phase transition to a spin density wave phase before the system reaches the paramagnetic phase. The origin of this phase is the non-trivial dependence of the topological insulator spin susceptibility on the momentum. We analyze the coupling of the non-uniform magnetic phase with the Dirac electronic system that occurs at the surfaces of the topological insulators.Comment: 7 pages. Major changes. the message has been revised and expande

Correlations Among First and Second Lactation Milk Yield and Calving Interval

Estimates of genetic correlations were .17 between first lactation milk yield and concurrent calving interval, .10 between second lactation milk yield and first calving interval, and .82 between first and second milk yields. Corresponding phenotypic correlations were .27, .16, and .58. Heritability estimates were .27 and .25 for first and second lactations and .15 for calving interval. Estimates were averages of two samples of 15 New York State herds averaging 144 Al-sired Holstein cows and 30 sires. Milk yields were 305-d, mature equivalent. Calving interval was days between first and second freshening. First milk records without a second freshening were included. Multiple- trait animal model included separate herd-year-season effects for first and second milk yields and calving interval. Numerator relationships among animals within herd, except for daughter-dam relationships, were included. The REML with the expectation-maximization algorithm was used to estimate (co)variance matrices among genetic values and environmental effects for the three traits. Results indicate a need to adjust milk records for the phenotypic effects of current and previous calving interval. The genetic association, however, between fertility and milk yield appears small. Genetic improvement of 450 kg of milk yield may result in 2 added d to first calving interval

Age-of-dam adjustment factors for birth and weaning weight records of beef cattle: a review

Age-of-dam adjustment factors are used to pre-adjust birth and weaning weight data for national beef cattle genetic evaluations. Adjustments are used in order to make the means of the different age-of-dam subclasses similar so that a fair comparison of animals can be performed. A review was made of various research studies that have estimated age-of-dam adjustment factors for birth weight and weaning weight of beef cattle. In general, birth weight age-of-dam adjustment factors are the same across the sexes, but weaning weight age-of-darn adjustment factors differ across the sexes, with heifer calves receiving smaller adjustments than their male counterparts. Additionally, adjustment factors vary greatly across breeds. Readjustment of records is difficult to do because a perfect estimate of adjustments is not possible. A more appropriate method for adjusting for age-of-dam is to simultaneously adjust during national genetic evaluations

Age-of-dam adjustment factors for birth and weaning weight records of beef cattle: a review

Age-of-dam adjustment factors are used to pre-adjust birth and weaning weight data for national beef cattle genetic evaluations. Adjustments are used in order to make the means of the different age-of-dam subclasses similar so that a fair comparison of animals can be performed. A review was made of various research studies that have estimated age-of-dam adjustment factors for birth weight and weaning weight of beef cattle. In general, birth weight age-of-dam adjustment factors are the same across the sexes, but weaning weight age-of-darn adjustment factors differ across the sexes, with heifer calves receiving smaller adjustments than their male counterparts. Additionally, adjustment factors vary greatly across breeds. Readjustment of records is difficult to do because a perfect estimate of adjustments is not possible. A more appropriate method for adjusting for age-of-dam is to simultaneously adjust during national genetic evaluations

MEASURES OF RACETRACK PERFORMANCE WITH REGARD TO BREEDING EVALUATION OF TROTTERS

Trotting records on the Finnish Horse were divided into two subsets: the total data set, with 13,000 race records on 554 horses by 206 sires, and the summary data set, with 1,378 records summarized annually for each horse. The purpose of the study was to determine whether these data could be utilized in a simple, yet useful way for the assessment of breeding value. A total of 24 measures of performance based on time at finish, money won and rank at finish were studied in the summary data set. The total data set included four traits compiled from records made at ages of 3 through 6 years. The proportion of horses that started races and at the end of a race year had records different from those of unraced horses, i.e., different from zero, was 95, 82 and 40 through 77% for measures of performance based on time, money and rank, respectively. Simple correlations between best and average time for a year were in excess of .90. Repeatabilities for time at finish during a year were about .70. Both estimates imply that time records are relatively consistent over an entire year. Estimates of heritability for best time were about .30, whereas those for money and rank traits were small or even negative. The results from this study support the concept that best time in a year is the most useful measure for assessing sire breeding values based on progeny records

Genetics of Dairy Goats: A Review

The literature on genetics of dairy goats was reviewed to point out not only world wide research but also the need for research in the United States to achieve the goal of uniform national genetic evaluations similar to those now available for dairy cattle. The number of breeds studied and the variety of research are remarkable. The numbers of animals and records involved in most studies, however, suggest large sampling variances of estimates

Bohr-van Leeuwen theorem and the thermal Casimir effect for conductors

The problem of estimating the thermal corrections to Casimir and Casimir-Polder interactions in systems involving conducting plates has attracted considerable attention in the recent literature on dispersion forces. Alternative theoretical models, based on distinct low-frequency extrapolations of the plates reflection coefficient for transverse electric (TE) modes, provide widely different predictions for the magnitude of this correction. In this paper we examine the most widely used prescriptions for this reflection coefficient from the point of view of their consistency with the Bohr-van Leeuwen theorem of classical statistical physics, stating that at thermal equilibrium transverse electromagnetic fields decouple from matter in the classical limit. We find that the theorem is satisfied if and only if the TE reflection coefficient vanishes at zero frequency in the classical limit. This criterion appears to rule out some of the models that have been considered recently for describing the thermal correction to the Casimir pressure with non-magnetic metallic plates.Comment: 12 pages, no figures. Presentation has been significantly improved, more references included. The new version matches the one accepted for publication in Phys. Rev.

Yet another surprise in the problem of classical diamagnetism

The well known Bohr-van Leeuwen Theorem states that the orbital diamagnetism of classical charged particles is identically zero in equilibrium. However, results based on real space-time approach using the classical Langevin equation predicts non-zero diamagnetism for classical unbounded (finite or infinite) systems. Here we show that the recently discovered Fluctuation Theorems, namely, the Jarzynski Equality or the Crooks Fluctuation Theorem surprisingly predict a free energy that depends on magnetic field as well as on the friction coefficient, in outright contradiction to the canonical equilibrium results. However, in the cases where the Langevin approach is consistent with the equilibrium results, the Fluctuation Theorems lead to results in conformity with equilibrium statistical mechanics. The latter is demonstrated analytically through a simple example that has been discussed recently.Comment: 6 pages, 6 figure