1,766 research outputs found

    In situ observations of fish associated with coral reefs off Ireland

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    The abundance and behaviour of fish on and around coral reefs at Twin Mounds and Giant Mounds, carbonate mounds located on the continental shelf off Ireland (600-1100. m), were studied using two Remotely Operated Vehicle (ROV) dives. We recorded 30 fish taxa on the dives, together with three species of Scleractinia (Lophelia pertusa, Madrepora oculata and Desmophyllum cristagalli) and a diverse range of other corals (Antipatharia, Alcyonacea, and Stylasteridae). Stands of live coral provided the only habitat in which Guttigadus latifrons was observed whereas Neocyttus helgae was found predominantly on structural habitats provided by dead coral. Significantly more fish were found on structurally complex coral rubble habitats than on flatter areas where coral rubble was clogged with sand. The most common species recorded was Lepidion eques (2136 individuals), which always occurred a few cm above bottom and was significantly more active on the reefs than on sedimentary habitats. Synaphobranchus kaupii (1157 indiv.). , N. helgae (198 indiv.) and Micromesistius poutassou (116 indiv.) were also common; S. kaupii did not exhibit habitat-related differences in behaviour, whilst N. helgae was more active over the reefs and other structured habitats whereas M. poutassou was more active with decreasing habitat complexity. Trawl damage and abandoned fishing gear was observed at both sites. We conclude that Irish coral reefs provide complex habitats that are home to a diverse assemblage of fish utilising the range of niches occurring both above and within the reef structure. © 2011 Elsevier Ltd

    Early-Life Stress Triggers Juvenile Zebra Finches to Switch Social Learning Strategies.

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    This is the final version of the article. Available from Elsevier (Cell Press) via the DOI in this record.Stress during early life can cause disease and cognitive impairment in humans and non-humans alike. However, stress and other environmental factors can also program developmental pathways. We investigate whether differential exposure to developmental stress can drive divergent social learning strategies between siblings. In many species, juveniles acquire essential foraging skills by copying others: they can copy peers (horizontal social learning), learn from their parents (vertical social learning), or learn from other adults (oblique social learning). However, whether juveniles' learning strategies are condition dependent largely remains a mystery. We found that juvenile zebra finches living in flocks socially learned novel foraging skills exclusively from adults. By experimentally manipulating developmental stress, we further show that social learning targets are phenotypically plastic. While control juveniles learned foraging skills from their parents, their siblings, exposed as nestlings to experimentally elevated stress hormone levels, learned exclusively from unrelated adults. Thus, early-life conditions triggered individuals to switch strategies from vertical to oblique social learning. This switch could arise from stress-induced differences in developmental rate, cognitive and physical state, or the use of stress as an environmental cue. Acquisition of alternative social learning strategies may impact juveniles' fit to their environment and ultimately change their developmental trajectories.We thank Ben Sheldon, Kevin Laland, Will Hoppitt, Lucy Aplin, Bram Kuijper, and Willem Frankenhuis for their constructive feedback, James Sturdy for his help scoring the videos, and Roland Stump for his help setting up the PIT/RFID system. D.R.F. was funded by grants from the NSF (NSF-IOS1250895) to Margaret Crofoot and BBSRC (BB/L006081/1) to Ben Sheldon, K.A.S. was funded by a BBSRC David Phillips Research Fellowship, and N.J.B. was funded by a Netherlands Organization for Scientific Research (NWO) Rubicon grant

    A novel locus of resistance to severe malaria in a region of ancient balancing selection.

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    The high prevalence of sickle haemoglobin in Africa shows that malaria has been a major force for human evolutionary selection, but surprisingly few other polymorphisms have been proven to confer resistance to malaria in large epidemiological studies. To address this problem, we conducted a multi-centre genome-wide association study (GWAS) of life-threatening Plasmodium falciparum infection (severe malaria) in over 11,000 African children, with replication data in a further 14,000 individuals. Here we report a novel malaria resistance locus close to a cluster of genes encoding glycophorins that are receptors for erythrocyte invasion by P. falciparum. We identify a haplotype at this locus that provides 33% protection against severe malaria (odds ratio = 0.67, 95% confidence interval = 0.60-0.76, P value = 9.5 × 10(-11)) and is linked to polymorphisms that have previously been shown to have features of ancient balancing selection, on the basis of haplotype sharing between humans and chimpanzees. Taken together with previous observations on the malaria-protective role of blood group O, these data reveal that two of the strongest GWAS signals for severe malaria lie in or close to genes encoding the glycosylated surface coat of the erythrocyte cell membrane, both within regions of the genome where it appears that evolution has maintained diversity for millions of years. These findings provide new insights into the host-parasite interactions that are critical in determining the outcome of malaria infection

    Protective role of aqueous extract of Hibiscus sabdariffa (calyx) against potassium bromate induced tissue damage in wistar rats

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    The protective role of aqueous extract of Hibiscus sabdariffa (calyx) against potassium bromate induced tissue damage was investigated in rat tissues (brain, kidney, stomach, spleen, heart and liver). The rats were divided into four groups. Group A was administered with 0.25 M sucrose only (base line control), Group B with 60 mg/kg body weight of potassium bromate, and Group C with 250 mg/kg body weight of extracts. Group D was administered 500 mg/kg body weight of extract. Group A and B were used as control groups, while Group C and D were the experimentals. The oral administration of potassium bromate to groups B, C and D were done eight hours before sacrifice. Lipid peroxidation was monitored by colorimetric determination of amino acid, protein and malondialdehyde level in the tissues. The organ-to-body weight ratio was taken as indication for inflammation and necrosis of the tissues investigated. The results of the test groups were statistically (p < 0.05) compared with the base linecontrol and the group B. There was no significant difference in the organ-to-body weight ratio in all the tissues investigated at both doses, when compared with base line control, but showed a significant decrease when compared with group B. The protein level of the tissues investigated showed a similar trend but the stomach shows significant increase in the protein level. This may be due to accumulation of the toxicant inducing protein synthesis. Amino acid level decreased significantly when comparedwith the base-line control and group B. This may be due to the extract ability to reduce proteolysis. Malondialdehyde level in the test groups decreased significantly in a dose dependent manner in all tissues investigated

    Impaired perception of facial motion in autism spectrum disorder

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    Copyright: © 2014 O’Brien et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Facial motion is a special type of biological motion that transmits cues for socio-emotional communication and enables the discrimination of properties such as gender and identity. We used animated average faces to examine the ability of adults with autism spectrum disorders (ASD) to perceive facial motion. Participants completed increasingly difficult tasks involving the discrimination of (1) sequences of facial motion, (2) the identity of individuals based on their facial motion and (3) the gender of individuals. Stimuli were presented in both upright and upside-down orientations to test for the difference in inversion effects often found when comparing ASD with controls in face perception. The ASD group’s performance was impaired relative to the control group in all three tasks and unlike the control group, the individuals with ASD failed to show an inversion effect. These results point to a deficit in facial biological motion processing in people with autism, which we suggest is linked to deficits in lower level motion processing we have previously reported
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