Analysis of growth and stable isotopes in teeth of male Australian fur seals reveals interannual variability in prey resources

To detect and monitor long-term ecosystem responses to environmental variability, managers must utilize reliable and quantitative techniques to predict future ecosystem responses. Canine teeth from 67 male Australian fur seals (aged 2-19 yr), collected at Seal Rocks, between 1967 and 1976, were measured for relative growth within the dentine growth layer groups (GLGs), as an index of body growth. Fluctuations in relative growth were apparent during 1956-1971, suggesting interannual variation in prey resources within Bass Strait. These were positively correlated with the Southern Oscillation Index and negatively with the Indian Ocean Subtropical Dipole, both on a 2 yr lag. The observed delay may reflect the time required for the nutrient cascade to filter through to the predominantly benthic prey of Australian fur seals. Stable isotope analysis (?15N/?13C) was also used to investigate whether fluctuations in growth were associated with differences in diet. Relative growth was found to be negatively correlated with ?15N, suggesting years of greater resource availability may be associated with individuals consuming proportionally more prey biomass of lower isotopic value. This study demonstrates that fluctuations in the dentine GLGs of male Australian fur seals are related to environmental parameters, suggesting variation in body growth is mediated by changes in prey resources

Inhibition of A/Human/Hubei/3/2005 (H3N2) influenza virus infection by silver nanoparticles in vitro and in vivo

Abstract
Silver nanoparticles (AgNPs) have attracted much attention as antimicrobial agents and have demonstrated efficient inhibitory activity against various viruses, including human immunodeficiency virus, hepatitis B virus, and Tacaribe virus. In this study, we investigated if AgNPs could have antiviral and preventive effects in A/Human/Hubei/3/2005 (H3N2) influenza virus infection. Madin-Darby canine kidney cells infected with AgNP-treated H3N2 influenza virus showed better viability (P,0.05 versus influenza virus control) and no obvious cytopathic effects compared with an influenza virus control group and a group treated with the solvent used for preparation of the AgNPs. Hemagglutination assay indicated that AgNPs could significantly inhibit growth of the influenza virus in Madin-Darby canine kidney cells (P,0.01 versus the influenza virus control). AgNPs significantly reduced cell apoptosis induced by H3N2 influenza virus at three different treatment pathways (P,0.05 versus influenza virus control). H3N2 influenza viruses treated with AgNPs were analyzed by transmission electron microscopy and found to interact with each other, resulting in destruction of morphologic viral structures in a time-dependent manner in a time range of 30 minutes to 2 hours. In addition, intranasal AgNP administration in mice significantly enhanced survival after infection with the H3N2 influenza virus. Mice treated with AgNPs showed lower lung viral titer levels and minor pathologic lesions in lung tissue, and had a marked survival benefit during secondary intranasal passage in vivo. These results provide evidence that AgNPs have beneficial effects in preventing H3N2 influenza virus infection both in vitro and in vivo, and demonstrate that AgNPs can be used as potential therapeutics for inhibiting outbreaks of influenza.

Bark in the park: a review of domestic dogs in parks

The presence of domestic dogs Canis familiaris in public open spaces is increasingly controversial. In our review of the literature, we located 133 publications of various types (papers, reports etc.) that examine some aspect of dogs in parks and open spaces (50 % focussed solely on dogs). There has been an exponential growth in the cumulative number of articles (R (2) = 0.96; 82 % published since 1997); almost all pertain to temperate latitudes (97 %) and most to the northern hemisphere (62 %). Most articles focus on impacts on wildlife (51 %), zoonotic diseases (17 %), and people's perceptions regarding dogs (12 %). Articles mostly describe problems associated with dogs, while reports of low compliance with dog regulations are common. We outline six major findings regarding dogs in parks: (1) there is a paucity of information on dogs in parks, particularly in relation to their interactions with wildlife and regarding their management; (2) published studies are mainly restricted to a handful of locations in developed countries; (3) sectors of societies hold different views over the desirability of dogs in parks; (4) the benefits and risks of dogs to humans and park values are poorly documented and known; (5) dogs represent a notable disease risk in some but not all countries; and (6) coastal parks are over-represented in the literature in terms of potential negative impacts. Park managers globally require better information to achieve conservation outcomes from dog management in parks.