Ontogenetic movements of juvenile blacktip reef sharks: evidence of dispersal and connectivity between coastal habitats and coral reefs

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Growth hormone modulates cholecalciferol metabolism with moderate effects on intestinal mineral absorption and specific effects on bone formation in growing dogs raised on balanced food

The aim of the study was to investigate the influence of growth hormone (GH) on Vitamin D3 metabolism and the subsequent effects on calcium (Ca) homeostasis and skeletal growth in growing dogs. A group of Miniature Poodles received supraphysiological doses of GH (GH group; n = 6; 0.5 IU GH per kg body per day) from 12 to 21 weeks of age and was compared with a control placebo-treated group (n = 8). Biologic activity of GH in the GH compared to the control group was indicated by (a) the 2.5- to 3.5-fold increase in the plasma concentrations of insulin-like growth factor I (IGF-I), (b) the increased production of 1,25-dihydroxycholecalciferol as indicated by the significantly increased plasma 1,25-dihydroxycholecalciferol concentrations and the 12.9-fold increase in renal 1alpha-hydroxylase gene expression, and (c) the inhibited production of 24,25-dihydroxycholecalciferol as indicated by the significantly lower plasma 24,25-dihydroxycholecalciferol concentrations and the similar levels of renal 24-hydroxylase gene expression. Despite the distinct effects on Vitamin D(3) metabolism in the GH group, there were only moderate effects on the intestine, i.e. at 20 weeks of age there was a significant increase of 14.4 and 5.6% in fractional absorption of Ca and phosphate (Pi), respectively, compared to the control group. GH administration resulted in significantly elevated glomerular filtration rate, with no differences in Pi urine excretion as a result of a concomitant increase in the tubular reabsorption of Pi. GH had only limited disturbing effects on endochondral ossification as indicated by the maintenance of the regularity of the growth plates. However, GH had specific anabolic effects on bone formation without concomitant effect on bone resorption that may result in disorders of skeletal remodeling and manifestation of enostosis.     

Retracted: Effect of Post‐Thaw Storage Time on Motility and Fertility of Cryopreserved Beluga Sturgeon (Huso huso) Sperm

The aim of this study was to test the influence of post ‐ thaw storage time on the duration of sperm motility, percentage of motile sperm, and fertilization and hatching rates of fresh sperm and sperm stored for 0, 30 and 60 min at 4°C post‐thawing. After being frozen in liquid nitrogen and then thawed, the percentage of motile sperm and duration of motility were not affected by 30 min of storage at 4°C, whereas a significant decline in these parameters was observed after 60 min of storage. Similarly, fertilization and hatching rates were significantly affected within 60 min of storage at 4°C, and the fertility of frozen‐thawed sperm was significantly lower than that of fresh sperm. We conclude that cryopreserved sperm of beluga sturgeon could be stored for 30 min without the loss of sperm quality. This described procedure for beluga sturgeon cryopreservation is reliable and efficient and therefore can be recommended for hatchery practice after scaling up this technique.     

Rhodococcus equi-associated osteomyelitis in foals

Two cases of Rhodococcus equl infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equl until proven otherwise.     

Host plant control of the inheritance of dinitrogen fixation in the Pisum-Rhizobium symbiosis

Summary The contribution of the host plant genome in symbiotic dinitrogen fixation has received little attention. In examining more than two thousand samples from the USDA Plant Introduction Collection, host-determined genetic variation in dinitrogen fixation has been found. In genetic analysis of a mutant line of Pisum resistant to nodulation, two genes designated Sym ₂ and Sym ₃ have been detected; Sym ₂ affects nodulation while Sym ₃ influences fixation. The two genes segregate independently as dominant Mendelian characters. Effective symbiosis requires the presence of at least one dominant gene at each locus.NRCC No. 146 96Preliminary report of some of this data has been made at the International Symposium on Nitrogen Fixation. Pullman. Washington, June 1974.     

Biological responses to porcine respiratory and reproductive syndrome virus in pigs of two genetic populations

One hundred pigs from the NE Index Line (NEI) and 100 Hampshire-Duroc cross pigs (HD) were inoculated intranasally with porcine respiratory and reproductive syndrome virus (PRRSV 97-7895 strain) at 26 d of age to determine whether genetic variation in response to PRRSV exists. An uninfected littermate to each infected pig served as a control. Pigs were from 163 dams and 83 sires. Body weight and rectal temperature were recorded, and blood samples were drawn from each pig on d 0 before inoculation and on d 4, 7, and 14 after inoculation. Pigs were sacrificed on d 14. Lung and bronchial lymph nodes were collected, placed in optimal cutting temperature compound, and frozen at -80 degrees C. The presence of PRRSV in serum and in lung tissue and bronchial lymph nodes was determined by isolation in cell culture. The presence of antibodies in serum collected on d 14 was determined by a commercial ELISA test. Lung tissue was examined microscopically and scored for incidence and severity of lesions (score of 1 to 3; 1 = no or few lesions, and 3 = severe interstitial pneumonia). Data were analyzed with a mixed model that included random sire and dam effects. The interaction of line x treatment was significant (P < 0.001) for weight change and rectal temperature. Un-infected HD pigs gained 0.67 kg more from d 0 to 14 and averaged 0.32 degrees C higher rectal temperature than uninfected NEI pigs (P < 0.001), whereas infected NEI pigs gained 0.34 kg more and had -0.54 degrees C lower temperature than infected HD pigs (P < 0.001). Viremic titer (cell culture infectious dose 50%/mL) was greater (P < 0.05) in HD than NEI at d 4 (10(4.52) vs. 10(4.22)), 7 (10(4.47) vs. 10(3.99)), and 14 (10(3.49) vs. 10(3.23)). Viral titer loads in lung (P = 0.11) and bronchial lymph nodes tended (P = 0.07) to be greater in HD than NEI pigs. Antibody signal-to-positive (S/P) ELISA ratios in infected pigs ranged from 0.18 to 3.38, and 88% had levels > or = 0.40, which is the positive threshold for this ELISA. The S/P range in uninfected pigs was 0 to 1.11, and 99% had levels < or = 0.40. Mean S/P ratio for infected pigs was 0.23 units higher in HD than in NEI (P < 0.001). The HD pigs had a greater incidence of interstitial pneumonia and 0.65 higher mean lesion scores than NEI pigs (P < 0.001). In summary, responses of pigs of the two lines to infection with PRRSV differed, indicating that underlying genetic variation existed.