Maximum Proportions Research Articles

Experimentally induced Haemonchus contortus infections in the rabbit

Haemonchus contortus originally derived from an Ontario field strain was used to infect laboratory rabbits. Both enshealthed and artificially exsheathed larvae were given at doses of up to 10 million larvae per rabbit. Only artifically exsheathed larvae were infective and a dose of at least 50,000 was required to produce a significant level of infection. H. contortus completed its development in the rabbit, but at a slower rate than in the sheep. Although a few fecund females were found 35 days after infection no eggs were observed on faecal examination. A high proportion of early fourth stage larvae were recovered from numerous rabbits including some which were examined well beyond a postinfection period when all worms should have been in the adult stage. This phenomenon occurred when freshly harvested and exsheathed larvae were used. Post-exsheathed cold conditioning of larvae at 5degreesC further increased the proportion of early fourth stage larvae (maximum proportions were found after 21 and again after 79 days of cold conditioning and thereafter declined). Whether such larvae were inhibited cannot be stated definitely. However, several of these larvae contained crystalline rods within their soma, and the structure of the crystals was similar to those previously described from inhibited H. contortus larvae recovered from sheep. It was concluded that the laboratory rabbit could be a useful host for further studies on some aspects of the biology and pathogenicity of H. contortus.

Plasma corticosteroid, circulating leukocyte and milk somatic cell responses to Escherichia coli endotoxin-induced mastitis.

SummaryA mammary quarter in each of 4 cows was infused with 0.5 mg E. coli endotoxin to determine its effect on plasma corticosteroids, circulating leukocytes and milk somatic cells. At 1.5 hr following endotoxin infusion, segmented neutrophils decreased 23%, and by 5 hr dropped 93%. A shift left in the differential circulating leukocyte count began at 2.5 hr and reached maximum proportions between 18-24 hr postendotoxin infusion. Circulating lymphocytes, monocytes and eosinophils were all depressed in response to endotoxin. Plasma corticosteroid concentrations increased (P < 0.01) 2 hr following endotoxin infusion, reached maximum concentrations at 4 hr, then returned to prein-fusion concentrations by 12 hr. The initial decrease in circulating lymphocytes at 2.5 hr was not attributed to the lytic effect of the plasma corticosteroids, since depressions in circulating lymphocytes occurred too soon (0.5 hr) after the increase in plasma corticosteroids. The high plasma corticosteroid concentration appeared t...

The effects of hormones on milk-fat synthesis in mammary explants from pseudopregnant rabbits.

1. When freshly prepared explants from pseudopregnant-rabbit mammary gland were incubated with sodium [1-(14)C]acetate plus glucose, they synthesized triglyceride and phospholipid containing long-chain fatty acids. Explants cultured with insulin and corticosterone also synthesized these products. The addition of prolactin to this culture medium increased the rate of fatty acid synthesis up to 40-fold and the explants synthesized predominantly triglyceride enriched with C(8:0) and C(10:0) fatty acids characteristic of rabbit milk. 2. The maximum rates of fatty acid synthesis obtained by explants from pseudopregnant-rabbit mammary gland after culture with insulin, corticosterone and prolactin were similar to those observed with freshly prepared explants from lactating-rabbit mammary gland. The time in culture required to attain these maximum rates varied between animals, and did not appear to be connected with the time required (6-7 days) to synthesize the maximum proportions of C(8:0) and C(10:0) acids. 3. As the pattern of short- and medium-chain milk fatty acids is characteristic for many species, the techniques described to determine the time-course for the development of this pattern can be used to investigate hormonal response.

Overwintering of Heliothis spp. in the Lower Rio Grande Valley, Texas12

Mature larvae of the tobacco budworm, Heliothis virescens (F.), and the bollworm, H. zea (Boddie), when collected from hosts in the lower Rio Grande Valley, Texas, and caged outdoors, did not diapause until late September. Emergence of moths from larvae collected in October, November, and December peaked in the winter and spring.; that of moths from larvae collected in January peaked in the spring. Mature larvae held in the laboratory at conditions favorable to pupation and emergence had maximum proportions diapausing in mid-October to early November.

High‐order compositeness in randomly distributed natural fats: Glyceride structure of an arecanut fat

AbstractA specimen of arecanut fat, 78 mol.‐% saturated acids, contained 54.9 fully saturated triglycerides (GS3), 8.1 mol.‐% tri‐unsaturated glycerides (GU3) and, for partly unsaturated triglycerides, 32.5 mol.‐%. GS2U and 4.7 GSU2 compared with 46.7, 1.1, 40.5 and 11.7 mol.‐%, respectively, expected for random distribution. The maximum proportions of GS3 and GU3 possible by any mechanism of esterification are shown to be the same as the random distribution values. The unusual structure of the fat is hence due to ‘high‐order compositeness’, i.e. it is produced by admixture of fats of widely differing saturated acid contents from different cells of the same tissue. Published data on the biogenesis of fat in ripening acrecanut support this concept. This heterogeneity was not evident from examination of the tissues.

HEREDITARY OSTEOARTHRITIS IN DAIRY COWS.

Bilateral spontaneous osteoarthritis of the stifle joint was observed to cause progressive lameness in 3 Holstein-Friesian and 52 Jersey cows 5–13 years old. Both breeds were represented by one herd each, and no affected males were ascertained in either herd. Pedigree information in case of the Holstein-Friesians and maximum likelihood proportions of arthritics in maternal halfsib families in case of the Jerseys suggest inheritance of the disease in dairy cows by means of a single pair of autosomal recessive genes. Penetrance is very low, mainly because of the variable and late age of onset. The literature concerning genetic aspects of the disease in mammals is reviewed.

Periploca nigra, a Major Cause of Dieback of Ornamental Juniper in California

Periploca nigra Hodges (Lepidoptera: Walshiidae) is a newly described species which is widely distributed in California. Severe twig dieback of juniper results from the girdling of the stems, beneath the bark, by the larval stage. Because of the nature of the injury, the common name—juniper twig girdler—is proposed for P. nigra . Hosts on which the insect has been collected thus far include: Juniperus chinensis L., J. horizontalis Moench., J. sabina L., and J. virginiana In the San Francisco Bay area in 1963, pupation in the twigs began in late March and reached maximum proportions in early June. Emergence of moths occurred in June and July. Eggs are laid singly on the bark of the twigs, and new larvae were first found in late July. There was no evidence of a second generation. An undescribed braconid ( Microchelonus sp.) exerts a measure of biological control of the larvae.

Denver Basin: ABSTRACT

The Denver basin is one of the largest structural basins in the Rocky Mountain area and extends across portions of Colorado, Nebraska, and Wyoming. The basin is typically asymmetrical with its axis paralleling and close to the Front Range. The deepest portion of the basin lies near Denver, where more than 12,500 feet of sediments are present. Recently discovered outcrops suggest that during pre-Pennsylvanian time, the Denver basin area was a normal marine shelf receiving sediments from early Paleozoic seas. Post depositional uplift along Siouxia exposed this area to deep erosion removing nearly all the early sediments. In Early Pennsylvanian time, transgressive seas entered the Denver basin area from the Anadarko basin, depositing a predominantly clastic terrane. Near the end of the Atoka, the first major pulses of the Ancestral Rockies occurred. This uplift reached maximum proportions during the Des Moines. Clastic material eroded from the uplifted mountains was deposited contemporaneously with marine sediments deposited in the expanding seaway. This expansion reached its maximum during the Missourian and was followed by a slight Virgil regression. Continued Permian regression left a full suite of environments and facies ranging from normal marine through an evaporitic sequence to terrestrial deposits. Late Permian and Triassic sediments indicate the Ancestral Rockies were weakly positive and suppl ed sediments to a shallow hypersaline sea. Non-depositional conditions persisted from Upper Triassic through Lower Jurassic, and into Mid-Jurassic time. During Middle and Upper Jurassic time, transgressive seas fluctuated across the basin from the northwest. As these seas regressed at the close of the Jurassic, a broad inland flood plain developed. Early Cretaceous seas inundated the area from the north and south reworking earlier sediments and obscuring the Jurassic-Cretaceous boundary. Initial basin-forming movement occurred at this time. Fluviatile material from exposed areas to the east and northeast developed a complex deltaic pattern as it interfingered with marine sediments basinward. Deltaic deposits also extended into the area from the southwest merging with sediments from the east. Another cycle of transgression and regression developed similar depositional patterns. It is within these two Early Cretaceous sedimentary End_Page 1880------------------------------ cycles that significant reserves of oil and gas have been discovered. In the Upper Cretaceous, a major transgression joined the northern and southern seas into a large seaway crossing the downwarping basin, and lapping against the uplifted Front Range. This Laramide tectonic activity reached its peak during the Eocene with the basin acquiring its present configuration. End_of_Article - Last_Page 1881------------

Biochemical significance of serum glycoproteins. I. Changes in rat serum following injury.

SummaryChanges produced in distribution of serum proteins of rats by injury were studied using paper electrophoresis. The electrophoretic distribution of glycoproteins was determined by measuring the concentrations of hexosamine in 4 zones, albumin + α1, α2, β, and γ globulins. Parallel elevations of serum hexosamines and proteins which are classified as α2 and β globulins were observed in response to 2 kinds of experimental injury. These increases reached maximum proportions 2 to 4 days after injury.

The Processes of Business Revival in the Light of 1933 Conditions

The significance of business revival processes depends greatly upon what business is reviving from, and toward what future it is reviving. Ordinarily, a study of the processes of revival from a depression is important only because it helps one to figure the relative strength of the existing forces, and to forecast the timing; for ordinarily depressions are much the same, and the requirements for recovery are very similar. In the midst of the 1933 depression, however, the facts are in so much dispute that it is necessary to consider what we are reviving from. Furthermore, the processes are so involved in revolutionary schemes of collectivism and social control, that what we may be reviving for, is not at all clear. Under the New Deal, the existence of economic laws or equilibria is not recognized, but in their place we have someone's wishes for a 1926 level, or someone's notions about social justice. Seen in historical perspective, cycles when subjected to broad economic analysis, are very simple. (Only the selfish interests of politicians, and individuals whose opinions are perverted by personal losses, previous erroneous forecasts, etc., can keep one from recognizing this fact.) The plain facts are these. (1) Each business cycle starts with an upswing which develops into a boom. The cycle begins with a rising period, and the logical starting point is the normal or equilibrium level reached after recovery from the preceding depression. It follows that in 1933 we were still in the late phase of a cycle which began in 1927. (2) The peak, or the ultimate maximum of the cyclical rise, is fixed by the limits of disequilibrium. A moment's reflection makes it clear that no outstanding failure or loss of confidence would be fatal or terminate a boom, if conditions were sound. The striking phenomena which usually mark the period are not fortuitous, and are significant only as indicating the character of the maladjustments or disequilibria which are the real causes of the ensuing recession. The upper limit depends upon the force of the boom, the factors which facilitate expansion, the resistances to expansion, and the occurrence of any conjunctural events which may serve to precipitate these factors. In the case of all great wars government credit becomes so involved that facilitating factors are strengthened, and resistances are weakened, so that booms are apt to attain maximum proportions.

Effect of composition of air on the growth and mortality of the chick embryo

AbstractThe fertilized hen's eggs of known origin were incubated under predetermined, standardized, and uniform conditions of all physical factors except air, the composition of which in respect to the carbon dioxide and oxygen varied in each experiment. The growth and mortality of the embryo were studied daily, with, on an average, four observations.The experimental data show that the continuous exposure to about 0.4 per cent of carbon dioxide in the air of the incubator stimulated growth during the first part of embryonic life. A high content of carbon dioxide and at the same time a slightly reduced content of oxygen resulted in diminishing of the size and increasing of mortality of the embryo. The maximum combined proportions of these gases possible for growth of the embryo were about 22.0 and 16.3 per cent, respectively. A temporary exposure (twenty‐four and forty‐eight hours) to a large amount of carbon dioxide resulted in diminishing the size of the embryo without apparent deformities or increase of mortality.

British Food Journal Volume 8 Issue 4 1906

Next after butter and milk—as regards the total number of samples examined—come spirits, of which 6,938 samples were dealt with. Of the articles of which sufficiently numerous analyses were made to furnish reliable data, spirits as a class are the most extensively adulterated, and the 12 per cent. of adulteration recorded for the year under review does not, in all probability, nearly represent the real extent of the evil. Many samples are returned as genuine which have been watered beyond the legal limit because the vendors have exhibited dilution notices, a method of legalising what are essentially fraudulent practices which is, unfortunately, being extended to other foods and drinks, and bids fair to bring the whole execution of the “Acts” to a standstill. In addition to this there are the widest differences of opinion and practice amongst both Public Analysts and Local Authorities as regards those spirits which have been the subjects of prosecution, on account of their origin or mode of manufacture, i.e., for being partially or entirely the product of the “patent still.” Prosecutions of brandy for containing spirit not derived from the grape have been fairly common, and similar offences connected with whisky and rum have also been brought before the courts, and yet the proportion of “spirits” now found to be adulterated is 30 per cent. lower than it was ten years ago, when watering was practically the only offence recorded. In view of the interest aroused and the intrinsic importance of the whole question some details and some guidance also might be looked for in such a report as this. Unfortunately the spirits are all lumped together under one heading, and although the presence in brandy of alcohol not derived from the grape is referred to, no further details are given. It is, no doubt, the case that the Local Government Board is not in a position to express an authoritative opinion on any of the difficult problems to which we have referred, and has no legal power to fix standards or enforce their use; nevertheless the mere statement of the number of prosecutions, of brandy, for instance (for containing other than grape‐derived spirit) together with the maximum and minimum proportions of the foreign spirit or the figures for esters in the corresponding cases would have at least shown to what extent the recently promulgated standards for this liquor had gained acceptance throughout the country.