From October 1983 to July 1984, the north hemisphere of Venus, from latitude 30 degrees to latitude 90 degrees , was mapped by means of the radar imagers and altimeters of the spacecraft Venera 15 and Venera 16. This report presents the results of the radar mapping of the Maxwell Montes region, one of the most interesting features of Venus' surface. A radar mosaic map and contour map have been compiled. 相似文献
The purpose of this paper is to emphasize the importance of pulmonary auscultation for the clinician. It suggests a clarification and simplification of the terminology to be used which would be helpful to veterinary students and allow better communications between veterinarians. The interpretation of these sounds and the relationships to conditions and diseases of the lungs in cattle, horses, sheep and goats are discussed. 相似文献
Studies on the social insects (ants, bees, wasps, and termites) have focused increasingly on sociogenesis, the process by which colony members undergo changes in caste, behavior, and physical location incident to colonial development. Caste is determined in individuals largely by environmental cues that trigger a sequence of progressive physiological restrictions. Individual determination, which is socially mediated, yields an age-size frequency distribution of the worker population that enhances survival and reproduction of the colony as a whole, typically at the expense of individuals. This "adaptive demography" varies in a predictable manner according to the species and size of the colony. The demography is richly augmented by behavioral pacemaking on the part of certain castes and programmed changes in the physical position of colony members according to age and size. Much of what has been observed in these three colony-level traits (adaptive demography, pacemaking, and positional effects) can be interpreted as the product of ritualization of dominance and other forms of selfish behavior that is still found in the more primitive insect societies. Some of the processes can also be usefully compared with morphogenesis at the levels of cells and tissues. 相似文献
1. On average, over the laying year, a higher proportion of eggs were cracked from cages (4.6%) than from range (2.0%); the difference tended to increase as the flocks aged.
2. There was evidence that eggs from range had stronger shells: they required more energy to crack, shell thickness was greater and shell deformation at 70 weeks was less (though the difference was not significant).
3. The differences between systems in shell strength, although real, were small. It is probable that environmental insults make a much larger contribution than shell strength to differences in crack incidence.
4. Eggs laid by hens on range were larger (+ 6.8% at 36 weeks and + 2.9% at 70 weeks) than those laid by the same stock housed in cages. 相似文献
1. Methods for quantitative determination of proteolytic, lipolytic and haemolytic activities and egg yolk factors in semen are described.2. Comparative quantitative determinations of these enzyme activities in the semen of goat, ram, bull, boar, dog and horse have been carried out.3. Special interest attaches to the egg yolk turbidity factor which is found in goat semen and, in small concentrations, also in boar semen.4. As each species appears to have its specific enzyme pattern, regular enzymatic control does not seem to have great significance. 相似文献
1. Two experiments were conducted to evaluate the effects of including ascorbic acid (AA), palm oil or a combination of both in the diets of laying hens during the hot months in a tropical environment.
2. The inclusion of AA improved egg production, food intake and efficiency of utilisation, and decreased the cost of food per kg egg. The addition of 400 mg AA/kg diet gave the most efficient performance.
3. Palm oil inclusion reduced the effect of heat stress and increased egg production, egg weight, food intake and efficiency of utilisation.
4. When 200 mg AA and 50 g palm oil/kg were used, additive responses were obtained with further improvements in egg production, food cost and efficiency.
5. Ascorbic acid and palm oil when fed alone or in combination reduced the incidence of cracked eggs.
6. Thus, 400 mg ascorbic acid/kg of diet, 50 g palm oil or 200 mg AA plus 50 g palm oil/kg diet ameliorated the effects of heat stress in laying hens. 相似文献
1. A pause in egg production was induced in brown‐egg laying hens, aged 68 weeks, by feeding them whole oats for 7 d. Subsequently, these hens, together with control groups, were given laying diets with either 400 or 600 mg/kg iron. The 200 mg/kg of supplemental iron was added in the form of either ferrous sulphate or iron proteinate (chelated iron).
2. The feeding of whole oats halted egg production in 5.7 ±0.22 d and the duration of the pause was 8.3 ±0.78 d.
3. The induction of a pause improved the subsequent rate of egg production, egg output, efficiency of food utilisation, albumen quality, egg specific gravity and shell colour. It also increased food intake and body weight gain but neither egg weight nor the rate of mortality were affected.
4. Neither supplementation of the diet with iron nor its source had any significant effect on laying performance, egg quality or shell colour. 相似文献
Glasser's disease accounted for less than 1% of total swine mortalities in an 11 year retrospective postmortem survey of swine submissions at three provincial government diagnostic laboratories in southern Ontario. However, Glasser's disease was suspected in 17 of 83 boar mortalities at the Record of Production Boar Test Station between 1983 and 1985 and was much more common in specific-pathogen-free (SPF) boars than in conventional boars. The prevalence of the causative organism, Haemophilus parasuis, was determined for 19 SPF herds in Ontario classified as "Excellent" under the Ontario Swine Herd Health Policy. Nasal swabs from two-month-old pigs were cultured on chocolate agar containing 1.5 mug/mL lincomycin, 5 mug/mL bacitracin, and 0.1 mug/mL crystal violet. Three herds were negative for H. parasuis infection; 16 herds contained clinically healthy carrier pigs. 相似文献
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