A high-conductance cation channel from the inner membrane of the free-living soil bacteria Rhizobium etli

In this communication we reported the study of a cation channel present in the cytoplasmic membrane of the nitrogen fixing bacterium Rhizobium etli. Inner-membrane (IM) vesicles were purified and fused into planar lipid bilayers (PLBs), under voltage clamp conditions. We have found that fusion of IM-enriched vesicle fractions with these model membranes leads, mainly (>30% of 46 experiments), to the reconstitution of high-conductance channels. Following this strategy, the activity of a channel with main open conductance of 198 pS, in symmetrical 100 mM KCl, was recorded. The single-channel conductance increase to 653 pS in the presence of a 5:1 (cis to trans) gradient of KCl. The channel exhibits voltage dependency and a weak selectivity for cations showing a permeability ratios of P _Rb/P _K = 0.96, P _Na/P _K = 0.07, and a conductance ratio of γ_Rb/γ_K = 1.1. The channel here characterized represents a previously undescribed Rhizobium channel although its precise role in rhizobial physiology remains yet to be determined.     

Hunting among Moka Bubis in Bioko: dynamics of faunal exploitation at the village level

Hunting by Bubi villages around Moka, Bioko, and their impact on the local prey fauna was studied during July–August, 1992. Questionnaires were sent to 45 known hunters in the region in order to find out their techniques and hunting procedures. Hunting trips were also followed (a total of 204 km covered) and counts of animals brought to the villages from 103 recorded trips were also made. There were two main hunting methods employed: trapping and shooting. Most commonly used was snare trapping. At least five different types were used during the study. Guns were less commonly employed. Both techniques are efficient and productive but prey caught by each method differed. Most animals caught by snares were large rodents (Atherurus africanus, Cricetomys emini) and small antelopes (Cephalophus monticola) whereas those shot were usually antelopes (C. monticola and C. ogilbyi), monkeys (Cercopithecus spp.) and, when accompanied by dogs, drills (Mandrillus leucophaeus). The effects of hunting in the region is acute especially since they incur upon the proclaimed protected areas in the south of the island. Hunting trips are gradually being lengthened and areas which were originally unaffected by this activity are now part of the villages' hunting zones.     

In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial

Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31) versus an Augmented Reality system (N = 32) in a randomized controlled trial. “One-session treatment” guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants’ expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.     

How Predictability of Feeding Patches Affects Home Range and Foraging Habitat Selection in Avian Social Scavengers?

Feeding stations are commonly used to sustain conservation programs of scavengers but their impact on behaviour is still debated. They increase the temporal and spatial predictability of food resources while scavengers have supposedly evolved to search for unpredictable resources. In the Grands Causses (France), a reintroduced population of Griffon vultures Gyps fulvus can find carcasses at three types of sites: 1. “light feeding stations”, where farmers can drop carcasses at their farm (spatially predictable), 2. “heavy feeding stations”, where carcasses from nearby farms are concentrated (spatially and temporally predictable) and 3. open grasslands, where resources are randomly distributed (unpredictable). The impact of feeding stations on vulture’s foraging behaviour was investigated using 28 GPS-tracked vultures. The average home range size was maximal in spring (1272±752 km²) and minimal in winter (473±237 km²) and was highly variable among individuals. Analyses of home range characteristics and feeding habitat selection via compositional analysis showed that feeding stations were always preferred compared to the rest of the habitat where vultures can find unpredictable resources. Feeding stations were particularly used when resources were scarce (summer) or when flight conditions were poor (winter), limiting long-ranging movements. However, when flight conditions were optimal, home ranges also encompassed large areas of grassland where vultures could find unpredictable resources, suggesting that vultures did not lose their natural ability to forage on unpredictable resources, even when feeding stations were available. However during seasons when food abundance and flight conditions were not limited, vultures seemed to favour light over heavy feeding stations, probably because of the reduced intraspecific competition and a pattern closer to the natural dispersion of resources in the landscape. Light feeding stations are interesting tools for managing food resources, but don’t prevent vultures to feed at other places with possibly high risk of intoxication (poison).     

Genome-wide programmable transcriptional memory by CRISPR-based epigenome editing

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Variability in timing of larval season in an amphibian community in SW Spain

Timing of larval periods of 9 species of amphibians (Hyla meridionalis, Pelobates cultripes, Discoglossus galganot, Bufo calamita, Bufo bufo, Rana perezi, Triturus marmoratus, Triturus boscat, Pleurodeles waltl) was followed in 7 different years Total larval season may last from autumn to summer, whereas in low rainy years it may last from late winter to summer In rainy years, two species are early breeders, starting to breed m autumn, six species commonly start in mid-winter and one species always breeds later, in spring The widest interannual variability m the onset and duration of larval season occurs in the earliest breeders In general, the more rainy the autumn and the higher temperatures were reached, the earlier the season started In contrast, duration of the season was not correlated with rainfall and temperature Interannual variability is interpreted as the possibility of adjusting the reproduction of the species to the availability of breeding habitats, constrained by physiological features of the species and interspecific relationships