The effect of stocking density on growth in the gilthead sea-bream, Sparus aurata (L.)

The effect of stocking density on growth and size variability in gilthead sea-bream, Sparus aurata (L.), was tested by growing juveniles at densities of 0.35 kgm^?3, 1.3 kg m^?3 and 3.2 kg m^?3. Fish in the highest density group grew 25% slower than fish in the lowest density group. The coefficient of variation of weight (standard deviation/mean) did not change during the experiment. The effect of size variability on growth rate was tested by creating groups with coefficients of variation of weights ranging from 0.11 to 0.32, and growing them at similar density (1.5 kg m^?3). No differences in growth rates between groups were found. Only the more heterogeneous group showed a large decrease in the coefficient of variation over time. It was concluded that growth in gilthead sea-bream, although negatively correlated to stocking density, did not seem to be related to intraspecific competition as assessed by changes in size variability.     

Gammaherpesvirus infection in a free-ranging eastern grey kangaroo (Macropus giganteus)

A gammaherpesvirus was detected by polymerase chain reaction (PCR) in ocular, nasal and oropharyngeal swab samples collected from an adult free-ranging male eastern grey kangaroo (Macropus giganteus) with clinical signs of severe respiratory disease. This is the first time a gammaherpesvirus has been detected in a free-ranging macropod in Australia. The nucleotide sequence of a conserved region of the DNA polymerase gene of the detected virus showed a high degree of identity to a gammaherpesvirus recently detected in a zoological collection of eastern grey kangaroos in North America. The detection of this gammaherpesvirus in a free-ranging, native eastern grey kangaroo provides evidence that this species is a natural host.     

Erythrocyte migration and gap formation in rabbit blood clots in vitro

Thrombolytic agents must be carried by the blood circulation to thrombi to exert their functions. Structural gaps exist between blood vessels and thrombi or in the area surrounding thrombi. Therefore, information about fundamental gap formation at thrombotic areas is critically important for thrombolytic therapy. We previously reported that t-PA accelerates the activities of bovine erythrocytes and hemoglobin (Hb) towards bovine plasminogen activation. Here, we examined gap generation by observing morphological changes during thrombolytic processes in rabbit blood clots deformation of erythrocytes from blood clots and Hb transfer from erythrocytes to serum in vitro. Rabbit venous blood samples (1 ml) were stored under sterile conditions in glass tubes at 37°C for 2, 24, 48 h, 1, and 2 weeks. We examined clot diameter, erythrocyte diameter and number as well as Hb volume in the serum, as well as histological changes in the clots. The diameter of blood clots did not change until 2 weeks after sampling. Erythrocyte diameter decreased within 48 h and at 2 weeks after sampling at the clot surface (p < 0.001) and interior (p < 0.001). The number of erythrocytes in the serum started to increase starting from 24 h after sampling (p < 0.01). Serum Hb volume also gradually increased from 24 h until 2 weeks after sampling (p < 0.01). The erythrocyte envelope became disrupted and cytoplasm started to flow through pores into the serum at 24 h. The results indicated that blood clots are reduced due to clot retraction, erythrocyte dissociation and cytoplasm leakage without a distinct fibrinolytic reaction. These results indicated that gaps start to form between 2 and 24 h after blood clotting.     

Distinguishing male sterile and fertile cytoplasms in indica rice (Oryza sativa L.) by OPA 12

The majority of off-type plants in indica hybrid rice were CMS and its maintainer lines.     

Uterine environment as a regulator of birth weight and body dimensions of newborn lambs

Pure-bred embryos were transferred within and reciprocally between large (Suffolk) and small (Cheviot) breeds of sheep to establish 4 treatment groups: SinS (Suffolk embryos in Suffolk dams), SinC (Suffolk embryos in Cheviot dams), CinS (Cheviot embryos in Suffolk dams), and CinC (Cheviot embryos in Cheviot dams). The recipient ewes carried single fetuses to term. The maternal plasma concentrations of ovine placental lactogen (oPL), progesterone, IGF-1, FFA, and glucose were measured on d 50, 90, 120, and 140 of pregnancy. Birth weight, body dimensions, and placental characteristics of lambs were recorded at birth. There was a recipient ewe breed × lamb breed × time interaction for the concentration of oPL (P = 0.03), but no such interaction was observed for progesterone (P = 0.42), IGF-1 (P = 0.57), glucose (P = 0.36), or FFA (P = 0.72). There were no differences in oPL (P = 0.28) and progesterone (P = 0.34) concentrations between SinC and SinS ewes. The concentrations of FFA on d 140 (P = 0.008), and those of glucose on d 50 (P = 0.02) and 120 (P = 0.01), were greater in SinC ewes than in SinS ewes. The ewes in CinS had less FFA concentration (P = 0.002) at all time points than CinC ewes. The concentrations of IGF-1 on d 90 were greater (P = 0.004) in CinS ewes than CinC ewes, but did not differ (P = 0.16) on d 50, 120, and 140. The concentrations of glucose on d 50 (P = 0.001), 90 (P = 0.03), and 140 (P = 0.03) were less in CinS ewes compared with CinC ewes. The birth weight of SinC lambs (5.04 ± 0.20 kg) was lighter (P = 0.001) than SinS lambs (5.94 ± 0.19 kg), and body dimensions of SinC lambs were smaller (P = 0.01) than SinS lambs. Neither birth weight nor the body dimensions of CinS lambs differed (P = 0.24) from CinC lambs. Cotyledon number was reduced (P = 0.04) in the CinS (57.5 ± 6.3) compared with the SinS group (74.2 ± 5.9), whereas mean cotyledon weight in CinS (2.42 ± 0.20 g) was greater (P = 0.02) than SinS (1.74 ± 0.21 g). It was concluded that the large genotype lambs were lighter and smaller when born to small genotype dams; however, the birth weight or body dimensions of small genotype lambs did not differ when born to large genotype dams. This study suggests that plasma oPL, progesterone, IGF-1, FFA, and glucose concentrations at different times throughout pregnancy reflect the regulatory effect of the uterine environment on the development of the fetus.