Effect of Restricted Weight Gain and/or Dichlorvos on Reproductive Performance of Gravid Gilts

In recent years much of the interest in nutrition of the gravid sow has been centered around restricting feed intake regardless of the weight gain of the sow. It has now become a common practice to restrict intake so that weight gain during gestation is limited to a maximum of 75 to 100 pounds. More recently, there has been some interest in the feeding of 2, 2 – dichlorovinyl dimethyl phosphate (dichlorvos) near the end of gestation to attempt to increase the number of live pigs born and growth rate following birth

Absence of classical and quantum mixing

It is shown, under mild assumptions, that classical degrees of freedom dynamically coupled to quantum ones do not inherit their quantum fluctuations. It is further shown that, if the assumptions are strengthen by imposing the existence of a canonical structure, only purely classical or purely quantum dynamics are allowed.Comment: REVTeX, 4 page

Comparative Growth Rates of Different Strains of Rhizobium meliloti

The growth rates of two strains of Rhizobium meliloti were measured when the organisms were grown in a nitrogen-free medium and in a medium containing nitrate nitrogen. The strains used differed widely in their ability to aid the host plant in symbiotic nitrogen fixation. They also differed somewhat in cultural characteristics

Ultrasonic characterization of the pulmonary venous wall: echographic and histological correlation

Background: Pulmonary vein isolation with radiofrequency catheter ablation techniques is used to prevent recurrences of human atrial fibrillation. Visualization of the architecture at the venoatrial junction could be crucial for these ablative techniques. Our study assesses the potential for intravascular ultrasound to provide this information. Methods and Results: We retrieved 32 pulmonary veins from 8 patients dying from noncardiac causes. We obtained cross-sectional intravascular ultrasound (IVUS) images with a 3.2F, 30-MHz ultrasound catheter at intervals on each vein. Histological cross-sections at the intervals allowed comparisons with ultrasonic images. The pulmonary venous wall at the venoatrial junction revealed a 3-layered ultrasonic pattern. The inner echogenic layer represents both endothelium and connective tissue of the media (mean maximal thickness, 1.4±0.3 mm). The middle hypoechogenic stratum corresponds to the sleeves of left atrial myocardium surrounding the external aspect of the venous media. This layer was thickest at the venoatrial junction (mean maximal thickness, 2.6±0.8 mm) and decreased toward the lung hilum. The outer echodense layer corresponds to fibro-fatty adventitial tissue (mean maximal thickness, 2.15±0.36 mm). We found a close agreement among the IVUS and histological measurements for maximal luminal diameter (mean difference, -0.12±1.3 mm) and maximal muscular thickness (mean difference, 0.17±0.13 mm) using the Bland and Altman method. Conclusions: Our experimental study demonstrates for the first time that IVUS images of the pulmonary veins can provide information on the distal limits and thickness of the myocardial sleeves and can be a valuable tool to help accurate targeting during ablative procedures

The Influence of Alfalfa Coumestrol on the Reproductive Performance of Gilts

In Australia during the early 1940\u27sa syndrome known as clover disease was observed in sheep grazing subterranean clover. This syndrome was characterized by a marked reduction in fertility which was later proved to be due to a high content of estrogenic substances in the clover. Alfalfa has since been shown to contain varying levels of these plant estrogens. The most important of the plant estrogens present in alfalfa is coumestrol because of its relatively greater biological potency than the other plant estrogens and because of its more frequent occurrence. Plant physiologists have shown that alfalfa infected with certain fungus diseases contains a level of coumestrol which increases with the amount of disease present in the alfalfa plants. Since alfalfa meal is such an important source of nutrients for farm animals and is often included in swine rations this study was conducted to determine if alfalfa plants with coumestrol levels in excess of 100 parts per million (ppm) would have any effect on the reproductive performance of gilts when included in their ration

Modified gravity without dark matter

On an empirical level, the most successful alternative to dark matter in bound gravitational systems is the modified Newtonian dynamics, or MOND, proposed by Milgrom. Here I discuss the attempts to formulate MOND as a modification of General Relativity. I begin with a summary of the phenomenological successes of MOND and then discuss the various covariant theories that have been proposed as a basis for the idea. I show why these proposals have led inevitably to a multi-field theory. I describe in some detail TeVeS, the tensor-vector-scalar theory proposed by Bekenstein, and discuss its successes and shortcomings. This lecture is primarily pedagogical and directed to those with some, but not a deep, background in General RelativityComment: 28 pages, 10 figures, lecture given at Third Aegean Summer School, The Invisible Universe: Dark Matter and Dark Energy, minor errors corrected, references update

Comparative value of dry-rolled corn, distiller’s dried grains, and wheat middlings for receiving diets

Two 28-day receiving experiments were conducted using 620 exotic × British cross steers to evaluate differences in growth performance, morbidity, and mortality when fed diets containing dry-rolled corn, distiller’s dried grains with solubles, or wheat middlings. All diets contained approximately 60% concentrate and 40% roughage (alfalfa hay). Gain and efficiency tended to be poorer for cattle fed the wheat middling-based diet than for those fed corn. No notable differences were evident in terms of the percentage of cattle treated for respiratory disease. Feed intake and daily gain were improved slightly when corn was replaced by distiller’s dried grains, but efficiency was not changed. However, the incidence of respiratory disease also was higher for cattle fed the distiller’s grains diet in comparison to corn

The Puzzle of the Flyby Anomaly

Close planetary flybys are frequently employed as a technique to place spacecraft on extreme solar system trajectories that would otherwise require much larger booster vehicles or may not even be feasible when relying solely on chemical propulsion. The theoretical description of the flybys, referred to as gravity assists, is well established. However, there seems to be a lack of understanding of the physical processes occurring during these dynamical events. Radio-metric tracking data received from a number of spacecraft that experienced an Earth gravity assist indicate the presence of an unexpected energy change that happened during the flyby and cannot be explained by the standard methods of modern astrodynamics. This puzzling behavior of several spacecraft has become known as the flyby anomaly. We present the summary of the recent anomalous observations and discuss possible ways to resolve this puzzle.Comment: 6 pages, 1 figure. Accepted for publication by Space Science Review

The anatomy of the tendon of the Infundibulum revisited

The heart is a muscular organ supported by collagenous tissue. The collagenous tissue is condensed in certain areas to form a supporting framework, often called the fibrous skeleton. The so-called tendon of the infundibulum has previously been described as part of this skeleton, but its structure and incidence remain ill defined. The tendon was initially described as a strip of fibrous tissue running between the aortic root and the pulmonary trunk. Since information on its structure is vague, we sought to evaluate its existence in 100 formalin-fixed adult human hearts obtained from subjects ranging in age from 22 to 86 years, in 20 hearts from infants and children aged from 2 months to 6 years at the time of their death and in 10 cattle hearts. We used classical macroscopic anatomical techniques to demonstrate all the possible connections between the sinuses of the aorta and the pulmonary trunk. We then supplemented the macroscopic techniques with serial transverse histological sections taken through the vascular roots, staining the sections with the haematoxylin-eosin, van Gieson, Masson trichrome and orcein staining methods. Fascial bands surrounded by connective tissue were observed in all hearts. In 80 adult hearts and in 16 neonatal hearts we found fascial bands or strips, which connected the aortic and pulmonary roots. Only in two hearts, however, were we able to identify tendon-like structures, and histology revealed that these were formed by tightly packed collagen fibres intermingled with fat, most likely due to advanced age. Thus in those cases where a "tendon" was present it was no more than condensed fascial bands joining together the apposing sinuses of the arterial trunks. In our opinion, therefore, accounts in the literature describing the "tendon of the infundibulum" as a tendinous structure connecting the aortic and pulmonary roots do not accurately represent this anatomical structure