Proparathyroid hormone: biosynthesis by human parathyroid adenomas

Biosynthesis of a precursor (proparathyroid hormone) to human parathyroid hormone was demonstrated during incubation of tissue from parathyroid adenomas. The proparathyroid hormone is labeled more rapidly than parathyroid hormone during incubation with amino acids labeled with carbon-14 and is progressively converted to the hormone. Apparent differences in the relative rate of conversion of precursor to hormone found in different tumors suggest that proparathyroid hormone may accumulate in some of the tumors and be secreted into the circulation.     

Single crystals of transfer RNA: an x-ray diffraction study

Large single crystals of formylmethionyl transfer RNA have been prepared. An x-ray diffraction study shows that the material crystallizes in a hexagonal lattice with a equal to 170 angstroms, c equal to 234 angstroms. The diffraction pattern extends to spacings just under 20 angstroms at present. The crystals are heavily hydrated, containing 88 percent water.     

Fecal free: Biology and authority in industrialized Midwestern pork production

Ethnographically, “fecal free” is a lexical marker that invokes a form of industrialized swine husbandry used in large-scale confinement hog production. Using participant observation and interview research with Illinois contract hog producers, I explore the basis of this husbandry in the biological fragility of confinement hogs. Rather than biology being a simplistic “state of nature,” as it was in early neo-Marxist and populist studies of the 1970s, the frailty of confinement hogs suggests that industrial hog biology is a socially constructed state that justifies the use of contract-based hog production units and their coordination with animal processors. The frailty of confinement hogs results from their genetic characteristics, from the conditions in which they are raised, and from a production rationality that equates animal health with production efficiency. I detail the multiple-site methods, confinement technologies, and contract-based production organization required to raise biologically fragile hogs. And I link hog biology directly to the unequal contract-based relations between actors in industrial pork networks. My study emphasizes the relevance of ethnographic analyses within a political economy of agriculture by describing specific relations of inequalities in local and regional production units and distribution networks that form the building blocks of larger global agro-food systems.

AN ULTRAMICROSCOPIC STUDY OF THE TWO STAGES OF BLOOD COAGULATION

There is no reaction-basis for the division of the process of blood-coagulation into the two stages (transparent and opaque) which appearso strikingly in sloiwly-clotting mammalian blood. These stages are saperficial phenomena which merely reflect the extent of fibrin-formation. Coagulation is a gradual continuous process of fibrin-formation; and in the clotting of normal plasma, fibrin needles can be demonstrated in the earliest appreciable coagulum, however delicate, transparent or gellike.     

Effects of Bulk Density on Sediment Erosion Rates

By means of a recently developed flume, sediment erosion rates as a function of shear stress and with depth in the sediments have previously been determined for relatively undisturbed sediments from several rivers and lakes. These experiments demonstrated that erosion rates depended on at least the following parameters: bulk density (or water content) of the sediments, particle size distribution as well as mean particle size, mineralogy, organic content, and amounts and sizes of gas bubbles. In order to isolate and quantify the effects of one of these parameters, the bulk density, additional experiments have been done with reconstructed sediments and are reported here. These experiments first determined the bulk density as a function of depth in the sediments for three different types of sediments, for three different sediment core lengths, and for compaction times varying from 1 to 60 days. For each of these sediment cores and compaction times, the erosion rate as a function of shear stress and with depth was then measured and related to the local bulk density of the sediment. The results demonstrate that, for a particular sediment and shear stress, the erosion rate is a unique function of the bulk density and can be expressed as a product of powers of the shear stress and bulk density.     

MODELLING LEACHING OF INORGANIC Hg(II) IN A SCANDINAVIAN IRON-HUMUS PODZOL - VALIDATION AND LONG-TERM LEACHING UNDER VARIOUS DEPOSITION RATES

Increasing mercury contents are reported from freshwater systems and fish in northern Europe and North America. Mercury input from soils is a major source with the leaching being affected by increased atmospheric mercury deposition compared to pre-industrial times and by other environmental conditions such as acid rain. The results of a mathematical model-calculation of vertical inorganic Hg(II) leaching in a Scandinavian iron-humus podzol under different atmospheric input rates of mercury are presented. Leaching under background rain conditions was calculated to be considerably stronger than under acid rain conditions. Increasing fractions of deposited soluble or solute atmospheric mercury were leached from the O _f(h)-horizon with decreasing soil content of soluble mercury under acid rain conditions; this effect was less pronounced under background rain conditions. The steady state concentrations of soluble mercury of the upper soil horizons were calculated and compared with the actual concentrations of total (= soluble + insoluble mercury) and extractable (= estimate of soluble) mercury measured in these horizons. The results indicate that even if the deposition of airborne mercury to soil is strongly reduced, the total mercury content of the soil decreases only slowly. It may take decades or even centuries before a new steady state concentration of total mercury is established in the soil. The decrease of the mercury concentration in the O _f(h)-horizon is probably largely dependent on the turnover of organic matter, binding most of the deposited airborne mercury in an insoluble form. Hence, present day mercury leaching is likely to be dominated by mercury deposited during former times and temporarily retained in an insoluble form in the organic matter.     

Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

Successful sterlet, Acipenser ruthenus L., propagation with synthetic LH-RH hormone

Abstract. The synthetic LH-RH (luliberine) has proved to be successful in inducing the ovulation of sterlet, Acipenser ruthenus L. Three dosages of LH-RH 50, along with carp pituitary, and 100 and 300 μg/kg of body weight were administered, and 100 and 300 μg of LH-RH/kg body weight were found to be successful in ovulation. Spawners were kept at low temperature (9–12°C). Forty-two hours after treatment the eggs entered ovulation in the ovary and became suitable for stripping. The ripening ratio for spawners varied between 75 and 83%. The eggs that could be obtained by opening the abdominal wall were fertilized with milt diluted with pond water to avoid polyspermism. The fertility of the stripped eggs was 89–90%. Despite a reduced number of subjects (12 treated, 2 control females), as a result of the favourable fertilization percentage, approximately 55 000 fingerlings were reared in tanks to approximately 5–7cm in size.