Wolf pack rendezvous site selection in Greece is mainly affected by anthropogenic landscape features

In wolves, most offspring mortality occurs within the first 6–8 months of their life. As wolf pups pass this entire period at either the den or rendezvous sites, their selection by wolf packs may affect pup survival and recruitment. Rendezvous sites are important for pup survival as they are used during summer and early autumn, when intense human activity may increase pup mortality. Adult wolves and pups can be killed by livestock guarding dogs during summer and intentionally or accidentally during large game hunting in autumn. This study describes factors related to rendezvous site selection in order to enhance their protection and management. We studied the rendezvous site selection of 30 wolf packs in central and northern Greece between 1998 and 2010, after locating 35 sites using the simulated howling survey method and telemetry. We considered a series of environmental and anthropogenic predictors of wolf rendezvous site selection at two spatial scales. At the landscape-population scale, wolves selected rendezvous sites below 1,200 m asl, with large inter-site distance (mean, 12.9 km), and avoided partially forested or open habitats, indicating preference for covered, spaced areas with seasonally stable resources. At the home range scale, wolves selected rendezvous sites away from forest roads and villages, close to water sources, and in areas with low forest fragmentation, indicating avoidance of human presence and disturbance. In the summer of 2011, we used an ensuing resource selection model (RSF, AUC?=?0.818) to successfully locate seven new rendezvous sites outside our previous survey area, verifying the utility of prediction maps (all new sites were at areas with 0.8–1 model probability). Rendezvous prediction maps can be used to reduce field effort when monitoring wolf populations, assess livestock predation risk, design protected areas, and reduce human disturbance on reproductive wolf packs.     

The SMC5/6 complex compacts and silences unintegrated HIV-1 DNA and is antagonized by Vpr

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AT32P-dependent estimation of nanomoles of fatty acids: its use in the assay of phospholipase A2 activity

A procedure for the assay of free fatty acids which has been adapted for the assay of phospholipase A2 is described. This consists of the conversion of long chain fatty acids to fatty acyl-CoA using the Mg2(+)-dependent fatty acyl-CoA synthetase, [alpha-32P]ATP and coenzyme A. In order to ensure the complete conversion of the acid to its CoA ester pyrophosphatase is also added to the incubation mixture. AM32P formed in stoichiometric amounts is separated from the remaining AT32P by polyethyleneimine-cellulose thin-layer chromatography and the fatty acid content is calculated from the specific radioactivity of AT32P. As little as 1 to 3 nmol of fatty acids hydrolyzed from any phospholipid using nanogram amounts of phospholipase A2 can be estimated with reliability. The real advantage of the method is that it combines the sensitivity of a radiochemical procedure without having to use radiolabeled substrates for the assay of phospholipases.     

The effect of fire history in shaping diversity patterns of flower-visiting insects in post-fire Mediterranean pine forests

Fire affects diversity and structure of flower-visitor communities. We explored the effect of fire history on the diversity patterns and structure of the flower-visitor guilds (bees, beetles, flies, sawflies, and wasps), across a post-fire regeneration sequence of pine forests in Rhodes Island, Greece. Fire history was defined by fire frequency and post-fire age of sites. We did not find significant differences in species richness and abundance per guild between fire-history regimes except for the abundance of flies, sawflies and the entire flower-visitor community. Fire strongly affected the community structure of bees, beetles, and sawflies. Some of the most abundant and common species responded significantly to fire in terms of abundance; yet, we observed no significant variation in the abundance of the common species of bees, the most prominent pollinator group, implying that provision of pollination services may not be considerably affected by fire. Long-unburnt sites displayed higher heterogeneity in species composition compared to recently-burnt sites (either burnt once or twice). This pattern deviated significantly from null expectations when analyzing the abundance-based metric of β-diversity and was obscure in the case of the presence/absence-based metric, indicating that fire affected mainly the spatial distribution of individuals, i.e. the main change is not due to species turnover but to changes in relative abundance. Furthermore, the species composition in recently-burnt sites (burnt once in 2008) were more similar than in twice-burnt sites (including areas burnt once between 1984 and 1992, and in 2008), indicating that fire frequency affected post-fire heterogeneity of species composition.     

Expression and reconstitution of a biologically active human interferon-gamma receptor in hamster cells

We report the expression of the human interferon-gamma (Hu-IFN-gamma) receptor from a cDNA clone in an animal cell where both stable expression of the cloned receptor as well as its biological activity is demonstrated for the first time. Biological activity of the receptor (i.e. expression of surface histocompatibility antigens in response to human interferon-gamma) requires the presence of human chromosome 21 demonstrating the requirement for at least one other species-specific factor in the modulation of receptor action. This system should now facilitate delineation of regions involved in the binding of human interferon-gamma and receptor signal transduction.