RADIOTAGGING STUDIES OF BELUKHA WHALES (DELPHINAPTERUS LEUCAS) IN BRISTOL BAY, ALASKA

Research was conducted in Bristol Bay, Alaska, to determine the applicability of radiotagging to studies of behavior, distribution and movements of belukha whales. Backpack-style VHF transmitters were attached to two belukhas by pinning through the dorsal ridge. Both packages were shed after about 2 wk due to migration of the pin through the tissue. Movements of radio-tagged whales were essentially local within Kvichak Bay. Three basic respiration patterns were identified: surfacings that were grouped into breathing periods separated by longer dives; surfacings that did not occur during restricted breathing periods; and long-to-very-long surfacings separated by short-to-very-short dives. These patterns were interpreted as representing traveling, feeding and feeding or resting in very shallow water. Surface and dive interval data were used to calculate a correction factor of 2.75, which could then be applied to aerial survey counts to estimate the total number of belukha whales in the study area. Modifications to radio packages are necessary in order to increase retention time.     

Glycosylation of high-affinity thrombin receptors appears necessary for thrombin binding.

Monosaccharide binding competition, lectin affinity chromatography, and glycosylation inhibitors have been used to determine if glycosylation plays a role in thrombin-receptor interactions. Mannose appeared to specifically inhibit thrombin binding to mouse embryo (ME) and hamster fibroblasts. Concanavalin A bound to antibody-purified receptor fractions, and was used as an affinity ligand to purify receptor fractions that retained thrombin binding activity. Cells treated with tunicamycin (6.25 ng/ml) for 24 h lost approximately 35% of their high-affinity thrombin binding sites, yet binding of receptor monoclonal antibody TR-9 was not affected, indicating that the receptor was present in the membrane, but unable to bind thrombin. Thus thrombin receptor glycosylation may be directly involved in thrombin binding.     

Spatial and temporal factors associated with nest survival of Gray Flycatchers in managed ponderosa pine forests

Gray Flycatchers (Empidonax wrightii) breed in a variety of habitats in the arid and semi‐arid regions of the western United States, but little is known about their breeding biology, especially in the northern portion of their range where they nest in ponderosa pine (Pinus ponderosa) forests. From May to July 2014 and 2015, we conducted surveys for singing male Gray Flycatchers along the eastern slope of the Cascade Range in Washington, U.S.A, monitored flycatcher nests, and quantified nest‐site vegetation. We used a logistic‐exposure model fit within a Bayesian framework to model the daily survival probability of flycatcher nests. During the 2 yr of our study, we monitored 141 nests, with 93% in ponderosa pines. Mean clutch size was 3.6 eggs and the mean number of young fledged per nest was 3.2. Predation accounted for 90% of failed nests. We found a positive association between daily nest survival and both nest height and distance of nest substrates from the nearest tree. Flycatchers that locate their nests higher above the ground and further from adjacent trees may be choosing the safest alternative because higher nests may be less exposed to terrestrial predators and nests in trees that are farther from other trees may be less exposed to arboreal predators such as jays (Corvidae) that may forage in patches with connected canopies. Nests in trees farther from other trees may also allow earlier detection of approaching predators and thus aid in nest defense.     

Effect of the oral hypoglycemic agent 2-tetradecylglycidic acid on fatty acid oxidation in suckling rats in vivo and in perfused liver

The hypoglycemic agent, 2-tetradecylglycidic acid (TDGA), administered in vivo lowered the concentration of plasma glucose and ketone bodies but raised the concentration of liver and plasma triglycerides in 10-day-old suckling rats. Phospholipid and cholesterol content of the plasma and liver were unaffected by drug treatment. TDGA inhibited the in vivo oxidation of [1-¹⁴C]palmitate but not that of [1-¹⁴C]decanoate. In suckling rat liver perfusion, TDGA totally inhibited ketone body formation from palmitate and depressed ketone body production from decanoate by 20%. Liver ATP and ADP content in the presence of TDGA decreased although this was probably a reflection of the increased triglyceride content of the liver since the $\text{ATP}\text{ADP}$ was the same as control livers. The results are discussed in relation to the diet and to the inhibition of carnitine acyl transferase in suckling rats.     

The early pathogenesis of bovine mastitis due to Escherichia coli

The pathogenesis of coliform mastitis was studied after infusing each of ten lactating quarters of three dairy cows with a large dose (ca. 1 x 10(9) colony-forming units) of virulent Escherichia coli strain B117. This approach was adopted first to maximize the chance of observing microscopic lesions in the tissues of a gland and secondly to overwhelm the differences that might be shown between animals in their response to the infection. The infected glands were examined at intervals of up to 4 h after infection by scanning and transmission electron microscopy and by light microscopy. The earliest lesions were seen after 1 h and consisted of necrosis and sloughing of the epithelial cells of the teat and lactiferous sinuses. After 2 h this was more severe, and was followed by an intense neutrophil response. Neutrophils migrated through the epithelial lesions and at first remained attached to the epithelial surface, forming large mounds. This resulted in gross underestimation of the number of cells in the lumen of the gland when neutrophils in the secretion were counted. At no stage was there evidence of attachment of organisms to the epithelial cells. Tissue damage did not extent beyond the basement membrane, which helps to explain the rapid clinical resolution seen in most field cases of the disease. There was considerable variation in the degree of response shown by the three cows, and also within the infected glands, where the damage was most severe in the lactiferous and teat sinuses. It seems unlikely that all aspects of the disease could be attributed to endotoxin.     

Insulin-like growth factor-binding protein-1 is phosphorylated by cultured human endometrial stromal cells and multiple protein kinases in vitro.

The insulin-like growth factor-binding protein IGF-BP1 is a major secretory protein of human endometrial stromal cells decidualized in culture. Anion exchange chromatography and nondenaturing gel electrophoresis showed IGF-BP1 to exist in five electrophoretically and chromatographically distinct isoforms. IGF-BP1 variants migrated as a quintet on nondenaturing polyacrylamide gels and as a single band (28 kDa) on sodium dodecyl sulfate-polyacrylamide gels. Alkaline phosphatase treatment reduced the IGF-BP1 variants to a single band. Cells incubated with [32P]orthophosphate for 12 h secreted four 32P-labeled IGF-BP1 phosphovariants, and their migration coincided with those bands that were eliminated by alkaline phosphatase treatment. In cells treated with medroxyprogesterone acetate and relaxin, the concentration of phosphorylated IGF-BP1 was increased dramatically as compared with controls. All the phosphovariants were confirmed to be IGF-BP1 by their ability to be supershifted on nondenaturing polyacrylamide gels after binding a monoclonal antibody to IGF-BP1. Thin layer electrophoresis of IGF-BP1 acid hydrolysates showed IGF-BP1 to be phosphorylated exclusively on serine. Non-phosphorylated IGF-BP1 was phosphorylated by the catalytic subunit of the cAMP-dependent protein kinase and casein kinase II in vitro. This suggests that IGF-BP1 may be a substrate of multiple protein kinases in vivo.