Winter locomotor activity patterns of European hares (Lepus europaeus)

In this study, activity patterns of the European hare (Lepus europaeus) were analyzed during winter using global positioning system (GPS) collars on 24 hares in two study areas located in central Italy. We programmed the collars to collect 12 location points per day, for a duration of three months. Results show two distinct phases of activities related to the day–night cycle. The daytime phase is characterized by inactivity at the form while the second phase is characterized by movements. Males were more active than females, showing a constant locomotor activity during the whole night. Females showed two peaks of activity during the night with a reduction in the middle of this time period. The comparison between females of the two study areas showed difference in interfix distance in particular around sunset and sunrise. In fact the minimum daily movement between the two areas shows that foraging sites of area B are more distant than those of area A. The recent possibility to apply GPS collars on small–medium mammals provides a powerful instrument to study the behavioral ecology of the European hare, and consequently promote an effective population management strategy for the species conservation.     

Prejudice in the former Soviet Union

Research in the United States and Europe has focused on the prejudice of majority groups towards minority groups, the implication somehow being that majority groups were more prejudiced than minority groups. In the former Soviet Union, ethnic environments were more complex; the same ethnic group could be a majority in one region but a minority in others. Using a sample of 1,459 first‐ and fourth‐year university students from eight regions of the former USSR, this study focuses on Russian, Tatar and Ukrainian respondents (n = 821) to test the hypothesis that the status of an ethnic group (majority/minority) or in‐group bias explains members’ prejudice. According to in‐group bias, all ethnic groups are equally prejudiced, minority and majority alike, whereas group status posits that groups in a majority position are more prejudiced. Findings show that group status has greater impact on prejudice than does in‐group bias. This applies, however, only to Russians. Interpretations of the findings rest on Soviet history and the rise of nationalism during the breakup of the Soviet Union.     

Ion-mediated resistance to osmotic changes of ram spermatozoa: the role of amiloride and ouabain

The aim of this study was to evaluate whether the Na+/K+ and Na+/H+ exchange can maintain the function of fresh ram spermatozoa. We analyzed the quality parameters of spermatozoa from fresh ram ejaculates incubated in iso- (about 300 mOsm), hypo- (about 100 mOsm) and hyperosmotic (about 900 mOsm) media in the presence of ouabain a specific inhibitor of the Na+/K+ ATP-ase or amiloride, a specific inhibitor of the Na+/H+ antiporter. Ouabain increased the percentage of morphologically altered acrosomes in isoosmotic media (from about 10% to 15% in control to about 30% with 10(-4) M ouabain) and decreased the percentage of total motility (from about 80% in control to about 50% to 55% with 10(-4) M ouabain). Ouabain decreased the mean linearity component of motility and decreased the frequency of head displacement. The addition of ouabain increased the percentage of altered acrosomes in the hypo- and hyperosmotic media, although it did not modify viability in either media. Ouabain also increased the percentage of swollen tails in the hypoosmotic medium at higher concentrations of the inhibitor. Amiloride increased the percentage of altered acrosomes in all media although its effect was less intense than that of ouabain. In isoosmotic media, total motility was decreased from about 80% in control to about 65% with 10(-4) M amiloride. Motile spermatozoa incubated with amiloride showed a clear decrease of mean velocity and mean linearity and increased frequency of head displacement. In the hyperosmotic medium, adding amiloride decreased the percentage of viability and altered tails at concentrations as low as 10(-6) to 10(-5) M. Our results indicate that the active mechanisms which control Na+ transport play a significant role in the maintenance of function in ram spermatozoa subjected to different osmotic environments. These mechanisms may be important in maintaining ram sperm function both "in vivo" and "in vitro".     

Harmful effects of mustard bio-fumigants on entomopathogenic nematodes

Mustard (Brassica and Sinapis spp.) green manures tilled into the soil preceding potato crops act as bio-fumigants that are toxic to plant–parasitic nematodes, providing an alternative to synthetic soil fumigants. However, it is not known whether mustard green manures also kill beneficial entomopathogenic nematodes (EPNs) that contribute to the control of pest insects. We used sentinel insect prey (Galleria mellonella larvae) to measure EPN infectivity in Washington State (USA) potato fields that did or did not utilize mustard green manures. We found a trend toward lower rates of EPN infection in fields, where mustard green manures were applied, compared to those not receiving this cultural control method. In a series of bioassays we then tested whether the application of two mustard (Brassica juncea) cultivars, differing in glucosinolate levels, disrupted the abilities of a diverse group of EPN species to infect insect hosts. Mustard-exposure trials were conducted first in laboratory arenas where EPNs were exposed to mustard extracts suspended in water, and then in larger microcosms in the greenhouse where EPNs were exposed to green manure grown, chopped, and incorporated into field soil. In all trials we used G. mellonella larvae as hosts and included multiple EPN species in the genera Steinernema (Steinernema carpocapsae, Steinernema feltiae, Steinernema glaseri, and Steinernema riobrave) and Heterorhabditis (Heterorhabditis bacteriophora, Heterorhabditis marelatus, and Heterorhabditis megidis). In the laboratory, EPN infection rates were lower in arenas receiving mustard extracts than the control (water), and lower still when EPNs were exposed to extracts from plants with high versus low glucosinolate levels. Results were nearly identical when mustard foliage was soil-incorporated into greenhouse microcosms, except that the negative effects of mustards on EPNs developed more slowly in soil. Significantly, in arenas of both types one EPN species, S. feltiae, appeared to be relatively unaffected by mustard exposure. Together, our results suggest that the use of mustard bio-fumigants for the control of plant–parasitic nematodes has the potential to interfere with the biocontrol of insect pests using EPNs. Thus, it may be difficult to combine these two approaches in integrated pest management programs.     

Environmental stress increases variability in the expression of dental cusps

Teeth are an important model for developmental studies but, despite an extensive literature on the genetics of dental development, little is known about the environmental influences on dental morphology. Here we test whether and to what extent the environment plays a role in producing morphological variation in human teeth. We selected a sample of modern human skulls and used dental enamel hypoplasia as an environmental stress marker to identify two groups with different stress levels, referred to as SG (“stressed” group) and NSG (“nonstressed” group). We collected data on the occurrence and the relative development of 15 morphological traits on upper molars using a standard methodology (ASU‐DAS system) and then we compared the frequencies of the traits in the two groups. Overall, the results suggest that (a) stressors like malnutrition and/or systemic diseases have a significant effect on upper molar morphology; (b) stress generates a developmental response which increases the morphological variability of the SG; and (c) the increase in variability is directional, since individuals belonging to the SG have more developed and extra cusps. These results are consistent with the expectations of the current model of dental development. Am J Phys Anthropol 153:397–407, 2014. © 2013 Wiley Periodicals, Inc.