Proteolysis of very low density lipoprotein in perfused lung.

Perfusion of homologous 125I-labeled rat very low density lipoprotein through isolated rat lungs in the presence of heparin resulted in apoprotein proteolysis. At least the apoprotein C was degraded into two peptides smaller than 7500 daltons as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The lung uptake of radioactivity was small and due mainly to the presence of the larger of the two peptides. The lung protease was not active against an 125-I-labeled albumin substrate and was not released into the medium by heparin.     

Effect of residual enzymes on degradation of radioiodinated VLDL by collagenase-dispersed hepatocytes.

Liver cells isolated with crude collagenase rapidly catabolized radioiodinated VLDL. The hepatocytes retained proteolytically active elements of the preparative enzymes. Both collagenase in the absence of cells and hepatocytes prepared with collagenase degraded the C-apoproteins of labeled VLDL. Hepatocytes isolated with a chelating agent in place of collagenase deiodinated, but did not catabolize [¹²⁵I] labeled VLDL. Similarly prepared cells degraded labeled HDL, but addition of collagenase to incubations greatly enhanced this process. Therefore, data on hepatic catabolism of serum lipoproteins obtained with hepatocytes freshly prepared with collagenase must be interpreted with caution.     

Deciphering the “Fuzzy” Interaction of FG Nucleoporins and Transport Factors Using Small-Angle Neutron Scattering

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Acute toxicity effects of ibuprofen on behaviour and haematological parameters of African catfish Clarias gariepinus (Burchell, 1822)

Indiscriminate discharge of pharmaceutical waste into the aquatic ecosystem may pose serious health challenges to aquatic biota. The effect of acute exposure to ibuprofen was evaluated using changes in behaviour and haematological parameters under static bio-assay method in Clarias gariepinus. Test specimens were exposed to acute concentrations of ibuprofen (0.28, 0.33, 0.38, 0.43 and 0.48 mg l^?1) for 24, 48, 72 and 96 h durations respectively. Behavioural and phenotypic changes were observed in surviving fish. There were significant (p < 0.05) concentration and duration-dependent increases in erythrocyte (RBC), haemoglobin (Hb), pack cell volume (PCV) and leukocytes (WBC) in treated fish compared to the control. Insignificant decreases (p > 0.05) in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were observed in treated fish compared to the control. Ibuprofen elicited dose and duration- dependent decrease in neutrophil counts with the decreases being significant (p < 0.05) in the higher doses of 0.43 and 0.48 mg l^?1. Ibuprofen did not elicit any significant changes in monocytes, basophils and eosinophils. Changes observed in this study showed that ibuprofen negatively affected the health of the fish and we recommend that discharge of ibuprofen into the aquatic environment should be monitored and controlled.     

Race and ethnicity are not primary determinants in utilizing veterinary services in underserved communities in the United States

A retrospective database analysis (2011–2015) evaluated associations between race and ethnicity and veterinary service utilization by sampling 83,260 companion animals whose guardians (owners) self-identified as White, Black, or Latino/a from 39 Humane Society of the United States Pets for Life (PFL) sites across the United States. Controlling for socioeconomic status, the percentage of nonhuman animals sterilized through PFL whose owners were Latino/a or Black was substantially higher than in previously reported findings. While Latinos/as had the highest mean number of days from first contact with the program to consent, they also had the highest percentage of owners accepting the voucher during initial contact. Logistic regression models suggested that although meaningful, race and ethnicity were not primary determinants of veterinary service utilization. When veterinary and animal welfare organizations deliberately remove structural barriers embedded with racial inequalities, individuals, regardless of race and ethnicity, proceed with companion-animal sterilization. Therefore, service providers must use unbiased, informed, and culturally competent practices to improve companion-animal welfare through the optimization of veterinary services, including spay and neuter.     

The importance of shelter for butterflies in open landscapes

In Britain, much emphasis has been placed on conserving butterfly species in specialized habitats, since this is where most of its threatened butterflies exist, whilst the wider countryside has been largely overlooked. However, there is increasing awareness that small improvements to the dominant landscape could potentially reap huge benefits to the populations of many of Britains butterfly species. Recent studies have also stressed the importance of the landscape scale in the conservation of butterflies in small fragmented habitats. In this paper, we examine data from a variety of sources and conclude that the importance of shelter in open landscapes may be underestimated since recording is often restricted to the optimum conditions suggested by the Butterfly Monitoring Scheme. In less favourable conditions, butterflies may place greater reliance on those components of the landscape offering shelter. In light of the current policy of agricultural de-intensification we discuss how modifications to our current landscapes could benefit a wide range of species.     

Biometry and size distribution of Chrysaora hysoscella (Cnidaria, Scyphozoa) and Aequorea aequorea (Cnidaria, Hydrozoa) off Namibia with some notes on their parasite Hyperia medusarum

Novel data on the biometry, size distribution and parasitesof Aequorea aequorea and Chrysaora hysoscella are provided frominvestigations conducted during summer and winter in the northernBenguela ecosystem. The relationship between mass and diameterof C. hysoscella did not change on a seasonal basis, and thispossibly reflects the aseasonal nature of the food environment.The changes in the size structure of C. hysoscella across theshelf and with depth agree with postulated population maintenancestrategies in the region. Aequorea aequorea was not stronglyparasitized, butC. hysoscella was subject to occasional parasitismby Hyperia medusarum, especially in winter when C. hysoscellais thought to reproduce. Parasites were distributed in a typical,negative-binomial manner on their hosts, but load was independentof host size. As medusae increased in diameter so H. medusarumtended to move from other tissues to the gonads.     

Induction and regulation of juvenile hormone esterases during the last larval instar of the cabbage looper, Trichoplusia ni

Juvenile hormone esterase titres were monitored in gate I and gate II last instar larvae of Trichoplusia ni using JH III as substrate. Two peaks of activity were observed for both gate I and gate II larvae, although the first and second juvenile hormone esterase peaks for the gate II larvae are extended and delayed one day, respectively. Head or thoracic ligations before the prepupal stage lower or block the appearance of both esterase peaks. Juvenile hormone I and II, as well as homo and dihomo juvenoids can induce the second juvenile hormone esterase peak in both normal and ligated larvae, and increase the esterase titre during the first peak in nonligated larvae. Induction of the juvenile hormone esterases is possible in non-ligated larvae as soon as the moult to the last instar has occurred and in ligated larvae as soon as the first esterase peak has started to decline. Distinct mechanisms of regulation are present for the first and second juvenile hormone esterase peaks. Juvenile hormone does not appear to be involved in regulating its own metabolism by directly inducing the first esterase peak; however, evidence is consistent with a brief burst of juvenile hormone which occurs prior to pupation inducing the production of the second peak of juvenile hormone esterase activity.     

Seston quality controls zebra mussel (Dreissena polymorpha ) energetics in turbid rivers

Feeding processes and energetic balance of zebra mussels were both related to the quantity and quality of natural seston. Filtration rate and pseudofeces production increased while clearance rate remained constant with increasing seston concentration. Ingestion rate, assimilation efficiency, and assimilation rate all increased with increasing food quality, measured as the ratio of organic to inorganic material in the seston. Respiration rate did not change with either food quantity or quality. As a result, scope for growth declined with decreasing food quality, and fell below 0 cal mg⁻¹ h⁻¹ at an organic:inorganic ratio of 0.5. The association between feeding processes and food quality appears related to a breakdown in the ability of zebra mussels to selectively ingest high-quality organic particles when the organic content of the seston is low. Ingestion, assimilation efficiency, assimilation rate and scope for growth were all higher when seston was amended with an addition of a natural assemblage of algae. Food quality may be a better indicator of environmental conditions suitable for growth than food quantity. These results suggest that the conditions of high suspended inorganic sediment concentrations in large turbid rivers represent a difficult growth environment for the zebra mussel. Received: 12 May 1997 / Accepted: 7 July 1998