Sea temperature effects on depth use and habitat selection in a marine fish community

Understanding the responses of aquatic animals to temperature variability is essential to predict impacts of future climate change and to inform conservation and management. Most ectotherms such as fish are expected to adjust their behaviour to avoid extreme temperatures and minimize acute changes in body temperature. In coastal Skagerrak, Norway, sea surface temperature (SST) ranges seasonally from 0 to over 20°C, representing a challenge to the fish community which includes cold-, cool- and warm-water affinity species.publishedVersio

Effect of temperature, relative humidity and aphid developmental stage on the efficacy of the mycoinsecticide Mycotal® against Myzus persicae

The green peach aphid, Myzus persicae, is a major pest worldwide. An examination of the impact of temperature, relative humidity and developmental stages of M. persicae on the efficacy of the whitefly mycoinsecticide Mycotal®, based on Lecanicillium muscarium and the effects of infection on aphid fecundity was evaluated under controlled conditions. Although this fungus can be grown at a broad range of temperatures (15-30oC), the optimum temperature for control of M. persicae ranged between 20 and 30oC. L. muscarium had high efficacy as a microbial control against M. persicae between 55 and 90% relative humidity. Total mortality of aphids treated with different spore dosages of L. muscarium varied according to the developmental stage: adults, fourth and third instar nymphs of proved more susceptible than first instar nymphs. Although the fungus did not affect the rate of nymph production, the reproductive period of aphids significantly decreased with increasing the spore dosage. Thus, total fecundity of treated aphids was 22.6 ± 1.1 and 31.6 ± 2.4 offspring per adult at the medium (644 ± viable spore/mm2) and low (330 ± 40 viable spore/mm2) dosages, compared with 45.7 ± 4.3 offspring per untreated aphid. The results suggest that L. muscarium has the potential as a biological control agent of M. persicae. However, fungal infection appears to have no sub-lethal effects on the fitness of the host’s progeny

Human biogeography and faunal exploitation in Diamante River basin, central western Argentina

A biogeographic model used to describe human peopling of southern Mendoza, central western Argentina, proposed an intensification process activated by an increase in population growth rate during the Late Holocene. During this process, high-ranked resources at the surroundings of residential camps were depleted, and hunter–gatherers broadened their diet by incorporating a larger number of low-ranked prey and domesticated plant resources. In this paper, we evaluate an alternative hypothesis, focusing on zooarchaeological data from the Diamante River basin. The results show that faunal resource intensification does not appear to have occurred in the Diamante River basin during the Late Holocene. Faunal consumption in Diamante River basin mainly reflects the local fauna in each ecological zone. The data do not show a lack of higher ranked resources. We suggest it is more likely that the demographic increase was not significant enough to cause an impact on the faunal resources. The archaeological evidence should be improved and analysed in smaller scales to continue with the intensification debate.Fil: Otaola, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giardina, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Franchetti, Fernando Ricardo. University of Pittsburgh at Johnstown; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Who Eats Whom in a Pool? A Comparative Study of Prey Selectivity by Predatory Aquatic Insects

Predatory aquatic insects are a diverse group comprising top predators in small fishless water bodies. Knowledge of their diet composition is fragmentary, which hinders the understanding of mechanisms maintaining their high local diversity and of their impacts on local food web structure and dynamics. We conducted multiple-choice predation experiments using nine common species of predatory aquatic insects, including adult and larval Coleoptera, adult Heteroptera and larval Odonata, and complemented them with literature survey of similar experiments. All predators in our experiments fed selectively on the seven prey species offered, and vulnerability to predation varied strongly between the prey. The predators most often preferred dipteran larvae; previous studies further reported preferences for cladocerans. Diet overlaps between all predator pairs and predator overlaps between all prey pairs were non-zero. Modularity analysis separated all primarily nectonic predator and prey species from two groups of large and small benthic predators and their prey. These results, together with limited evidence from the literature, suggest a highly interconnected food web with several modules, in which similarly sized predators from the same microhabitat are likely to compete strongly for resources in the field (observed Pianka’s diet overlap indices >0.85). Our experiments further imply that ontogenetic diet shifts are common in predatory aquatic insects, although we observed higher diet overlaps than previously reported. Hence, individuals may or may not shift between food web modules during ontogeny

Serum homocysteine, vitamin B 12 and folic acid levels in different types of glaucoma

BACKGROUND: This study was performed to compare levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with primary open-angle glaucoma (POAG), pseudoexfoliative glaucoma (PEXG), normotensive glaucoma (NTG) and healthy controls. METHODS: Twentyfive patients with POAG, 24 with PEXG, and 18 with NTG, along with 19 control healthy subjects were included this prospective study. Levels of serum Hcy were measured using immunoassay, and those of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay. RESULTS: The mean Hcy concentration in the PEXG group was significantly higher (P < 0.001) as compared to the other groups. There were no significant differences with respect to the mean Hcy concentrations among other groups (P > 0.05). There were no statistical differences in serum vitamin B12 levels among POAG, PEXG, NTG and control subjects (P > 0.05). The mean serum folic acid level was significantly lower in the subjects with PEXG (P < 0.009). However, the mean folic acid concentrations among the other groups did not differ significantly (P > 0.05). CONCLUSION: Elevated levels of Hcy in PEXG may explain the role of endothelial dysfunction among patients with PEXG

Clamp-Crushing versus stapler hepatectomy for transection of the parenchyma in elective hepatic resection (CRUNSH) - A randomized controlled trial (NCT01049607)

<p>Abstract</p> <p>Background</p> <p>Hepatic resection is still associated with significant morbidity. Although the period of parenchymal transection presents a crucial step during the operation, uncertainty persists regarding the optimal technique of transection. It was the aim of the present randomized controlled trial to evaluate the efficacy and safety of hepatic resection using the technique of stapler hepatectomy compared to the simple clamp-crushing technique.</p> <p>Methods/Design</p> <p>The CRUNSH Trial is a prospective randomized controlled single-center trial with a two-group parallel design. Patients scheduled for elective hepatic resection without extrahepatic resection at the Department of General-, Visceral- and Transplantation Surgery, University of Heidelberg are enrolled into the trial and randomized intraoperatively to hepatic resection by the clamp-crushing technique and stapler hepatectomy, respectively. The primary endpoint is total intraoperative blood loss. A set of general and surgical variables are documented as secondary endpoints. Patients and outcome-assessors are blinded for the treatment intervention.</p> <p>Discussion</p> <p>The CRUNSH Trial is the first randomized controlled trial to evaluate efficacy and safety of stapler hepatectomy compared to the clamp-crushing technique for parenchymal transection during elective hepatic resection.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01049607">NCT01049607</a></p

Ghrelin as a novel locally produced relaxing peptide of the iris sphincter and dilator muscles

Ghrelin is a recently described acylated peptide, which works as a somatosecretagogue and has described effects on the smooth, skeletal and cardiac muscle. We examined the production and effects of ghrelin on relaxation of the iris muscles. Contractile effects of 1-5 human ghrelin (frGhr, 10(-9)-6 x 10(-5)M) and 1-5 human des-octanoyl-ghrelin (d-frGhr; 10(-9)-6 x 10(-5)M) were tested on iris rabbit sphincter (n=11 frGhr; n=7 d-frGhr), dilator (n=6 frGhr; n=6 d-frGhr) and rat sphincter (n=6 frGhr; n=8 d-frGhr) precontracted muscles. On rabbit sphincter the effect of frGhr was also tested in presence of: i) L-NA (10(-5)M; n=7); ii) indomethacin (10(-5)M; n=7); iii) DLys(3)GHRP6 (10(-4)M; n=6); and iv) apamin+carybdotoxin (10(-6)M; n=6). Furthermore, on rabbit dilator the effect of frGhr was tested in presence of DLys(3)GHRP6 (10(-4)M; n=7). Finally, ghrelin mRNA production was assessed by "in situ" hybridization in Wistar rat eyes (n=8). In all muscles, frGhr promoted a concentration-dependent relaxation, maximal at 6 x 10(-5)M, 1.5-3 min after its addition, decreasing tension by 34.1+/-12.1%, 25.8+/-4.8% and 52.1+/-10.3% in the rabbit sphincter, dilator and rat sphincter, respectively. In the rabbit sphincter the relaxing effects of frGhr were: (i) enhanced in presence of DLys(3)GHRP6 (118.1+/-21.1%); (ii) blunted by indomethacin; and (iii) not altered by apamin+carybdotoxin (36.4+/-14.4%) or L-NA (52.4+/-11.4%). Relaxing effects of d-frGhr in rabbit (43.3+/-5.2%) and rat (77.1+/-15.3%) sphincter muscles were similar to those of frGhr. In rabbit dilator muscle, d-frGhr did not significantly alter active tension and the relaxing effect of frGhr was blunted by GHSR-1a blockage. Ghrelin mRNA was identified in iris posterior epithelium. In conclusion, ghrelin is a novel, locally produced, relaxing agent of iris dilator and sphincter muscles, an effect that is mediated by GHSR-1a in the former, but not in the latter. Furthermore, in the sphincter it seems to be mediated by prostaglandins, but not by NO or K(Ca) channels.Portuguese Foundation for Science and Technology (nr. POCI/SAU-FCF/60803/2004) through Cardiovascular R&D Unit (FCT nr. 51/94). Authors are sincerely grateful to RS. Moura (SFRH/BPD/15408/2005), Development Unit, Health and Life Sciences Institute, School of Health Sciences, University of Minho, Braga, Portugal for her excellent contribution in the in-situ hybridization techniques

Specialization among amphipods: the invasiveGammarus tigrinushas narrower niche space compared to native gammarids

Human-mediated invasions of nonindigenous species are modifying global biodiversity. Despite significant interest in the topic, niche separation and specialization of invasive and closely related native sympatric species are not well understood. It is expected that combined use of various methods may reveal different aspects of niche space and provide stronger evidence for niche partitioning as compared to a single method. We applied the species marginality index (OMI) and species distribution modeling (SDM) in the northern Baltic Proper to determine (1) if environmental niche spaces at habitat scale differ between taxonomically and functionally closely related invasive and native gammarid species, and (2) whether the observed pattern relates to the species distribution overlap. Both methods agreed in notably narrower and more segregated realized niche of invasive Gammarus tigrinus compared to the studied native gammarids. Among native species, the distribution of G. zaddachi overlapped the most with G. tigrinus. Our results confirm that widespread colonization does not require a wide niche of the colonizer, but may rather be a function of other biological traits and/or the saturation of the recipient ecosystem. The niche divergence and wider environmental niche space of native species are likely to safeguard their existence in habitats less suitable for G. tigrinus

eDNA metabarcoding reveals dietary niche overlap among herbivores in an Indian wildlife sanctuary

As many ecosystems are under increasing pressure from invasive species, habitatdegradation, overgrazing and overharvesting, pollution, and climate change, dietaryniche monitoring is gaining importance. The Malai Mahadeshwara Wildlife Sanctuary(MMH) in southern India is home to several long-standing ethnic and tribal groups andsupports a considerable number of domestic herbivores (cattle, goats and water buffalo)as well as a range of wildlife (including several species of deer, bonnet macaque,and Asian elephant). We reconstructed dietary niche partitioning of the herbivoresoccurring in MMH using eDNA metabarcoding to quantify diet richness, composition,and overlap. In total, we distinguish 134 diet items (molecular operational taxonomicunits), covering 31 plant families. Overall, our results indicate 35% overlap indomestic and wild herbivore diet items. The greatest overlap is found for the dietaryniches of cattle and sambar deer (Pianka's niche overlap index: 0.68), and the dietaryniche of cattle also overlaps considerably with those of Indian hare (0.65) and Asianelephant (0.46). This suggests that these herbivores may compete for these foodplants in the case of limited availability, which could lead to exclusion of some herbivorespecies. Particular concern should go to bonnet macaque and Asian elephant astheir below average dietary richness could make them vulnerable to changes in theirenvironment. With increasing pressures on local wildlife from a range of differentfactors, DNA metabarcoding of fecal samples is a non-invasive method for monitoringchanges in animal diets, providing valuable information for the management ofbiodiversity in mosaic natural and anthropogenic landscapes