74 research outputs found

    Phonotaxis to advertisement calls by midwife toads (Alytes muletensis) is not necessarily related to mating

    Get PDF
    Previous studies with the Mallorcan midwife toad (Alytes muletensis) found that gravid females show inconsistent phonotactic preferences for male calls unless they are highly motivated to mate; and, non-gravid females will occasionally show phonotaxis to male advertisement calls. These results suggest that sometimes phonotaxis may not be related to seeking a mating partner. In this article we report on experiments that give further support to a non-mating function of phonotaxis in this species. Males and metamorphs were played conspecific male and female advertisement calls. Males that were expected to be unmotivated to mate were not less likely to respond to, or less consistent in their choice of, female calls than males who were expected to be motivated to mate. Metamorphs who were not yet in breeding condition nevertheless showed positive phonotaxis. We suggest that Mallorcan midwife toads may sometimes show phonotaxis simply to seek out refuges where toads aggregate

    Quelles variations subit la composition du peuplement d’Amphibiens dans les paysages nigériens subissant une dégradation sur le long terme ? Le cas d’un environnement de montagne.

    Get PDF
    Les forêts tropicales mondiales subissent une importante altération anthropique. Les données recueillies au cours de diverses études dans les forêts du Nigéria montrent que l'herpétofaune subit ces modifications d'habitat. En particulier, quand les environnements forestiers tropicaux se dégradent et bien que la diversité globale reste stable ou voire même augmente, on remarque que l'on passe d'une dominance d'espèces spécialistes forestières à une dominance d'espèces généralistes capables d'utiliser une large gamme d'habitats. La même modification s'observe quels que soient le type d'habitat (e. g. forêt basse temporairement inondée ou forêt de montagne) ou le taxon (e. g. anoures ou serpents). Un inventaire des amphibiens a été conduit en 2002 sur le plateau d'Obudu au Nigéria, qui est une zone d'intérêt majeur pour la conservation, abritant beaucoup d'espèces endémiques et menacées. L'environnement y a été gravement dégradé et a souffert d'une forte déforestation dans les années récentes ; le tourisme de plaisance, en pleine extension, menace d'avoir un impact encore plus grand. En comparant les résultats de cet inventaire à divers jeux de données des années 1960 et 1980, nous sommes en mesure de décrire les changements dans la composition des peuplements intervenus après de nombreuses années de perturbation anthropique et nous discutons les raisons du succès ou de l'échec d'espèces spécialistes ou généralistes particulières.Tropical forests worldwide undergo severe anthropogenic habitat alteration. We report here on various long-term studies in Nigerian rainforests and show that there appears to be a trend of change in herpetofaunal communities that follows this habitat change. Specifically, as rainforest environments become degraded there is a shift from a predominance of forest specialists to a predominance of generalists that are able to utilize a wide range of habitats (although overall species diversity may remain stable or even locally increase). The same shift is seen regardless of the type of habitat (e.g. seasonally flooded lowland forest or montane forest) or the taxa (e.g. anura or serpentes). An amphibian survey was conducted in 2002 in the Obudu plateau, Nigeria, which is an area of major conservation importance, containing many endemic and threatened species. The environment has been severely degraded and suffered heavy deforestation in recent years, and expanding leisure tourism threatens to have an even greater environmental impact. We compare the results from our current survey to other studies by previous authors conducted in the 1960’s and 1980’s to provide an insight into changes in community species composition after many years of anthropogenic disturbance. We discuss the reasons for the success and failure of particular specialist and generalist species

    Trophic niches of four sympatric rainforest anurans from southern Nigeria: does resource partitioning play a role in structuring the community ?

    Get PDF
    Le partage des ressources est un mécanisme qui peut réduire l'intensité de la compétition interspécifique dans un cortège d'espèces syntopiques, morphologiquement et éco-éthologiquement semblables. La documentation du partage des ressources, entre quatre espèces d'Anoures sympatriques, a été recherchée par l'examen du régime alimentaire (par dissection stomacale) de spécimens obtenus auprès de fournisseurs de viande de brousse dans le sud-est du Nigéria. Pour l'ensemble des quatres espèces, nous avons trouvé au total 32 différents types de proies. Ptychadena oxyrhynchus en a consommé 28, contre 17 pour P. aequiplicata, 15 pour Bufo maculatus et 10 seulement pour Hoplobatrachus occipitalis. Pour les courbes cumulatives de diversité des trois premières espèces un plateau a été atteint, montrant que la composition des régimes pouvait être considérée comme correctement établie. Les proies communes, consommées par les quatre espèces d'Anoures, étaient des Formicoidea, des Coléoptères adultes, des Aranéides, des Isopodes, des Oligochètes et des Pulmonés. Les proies communes, consommées par trois des quatre amphibiens, étaient des Dermaptères, des Hémiptères, des Odonates adultes et des Orthoptères. Les largeurs de tête variaient significativement entre les espèces d'Anoures ; toutefois, les deux espèces de Ptychadena ne montraient pas de différence significative entre elles sur ce point Pour trois espèces, la largeur de tête était significativement corrélée au volume de proies dans l'estomac. Le partage des ressources (en termes de types de proies) a été trouvé particulièrement net entre deux espèces de Ptychadena étroitement apparentées. La divergence entre Ptychadena oxyrhynchus et P. aequiplicata apparut telle que des analyses multivariées ont placé chacune d'elles, du point de vue alimentaire, plus près de Hoplobatrachus occipitalis ou de Bufo maculatus que de son congénère. Une divergence si forte semblerait jouer un rôle majeur dans le maintien de la structure de ce peuplement mixte d'Anoures.Resource partitioning is a mechanism that can reduce the intensity of inter-specifie competition between morphologically and eco-ethologically similar, syntopic species . Evidence for resource partitioning, between four syntopic anuran species, was investigated by examining the diet (through stomach dissection) of frogs bought from bush meat traders in southeastern Nigeria . Considering the four species together, a total of 32 different prey types were found. Ptychadena oxyrhynchus consumed 28 of them, while P. aequiplicata consumed 17 , Bufo maculatus 15 and Hoplobatrachus occipitalis only 10. For the first three species, the cumulative-diversity curves indicated that a plateau phase was reached, i .e . that the prey composition could be considered reliably assessed. Common prey items, which were consumed by all four anuran species, were : Formicoidea, Coleoptera adults, Araneidae, Jsopoda, Oligochaeta, and Pulmonata. Common prey items, which were consumed by three of the four amphibians, were : Dermaptera, Hemiptera, Odonata adults, and Orthoptera. Head width varied significantly between species, but there was no statistical difference between the two Ptychadena species. Head width was significantly correlated with prey volume in the stomach in each of three species. Resource partitioning (in terms of prey types) was found to be particularly strong between two closely related species of Ptychadena. The divergence bewteen Ptychadena oxyrhynchus and P. aequiplicata was such that multivariate analyses placed each one of them closer in feeding ecology to either Hoplobatrachus occipitalis or Bufo maculatus, than to their congener. Such strong divergence is hypothesized to play a major role in maintaining the structure of this mixed anuran community

    NorCPM1 and its contribution to CMIP6 DCPP

    Get PDF
    The Norwegian Climate Prediction Model version 1 (NorCPM1) is a new research tool for performing climate reanalyses and seasonal-to-decadal climate predictions. It combines the Norwegian Earth System Model version 1 (NorESM1) – which features interactive aerosol-cloud schemes and an isopycnic-coordinate ocean component with biogeochemistry – with anomaly assimilation of SST and T/S-profile observations using the Ensemble Kalman Filter (EnKF).publishedVersio

    Short-term symptom improvement in infants with suspected cow’s milk protein allergy using amino acid formula: a prospective cohort analysis

    Get PDF
    BackgroundCow’s milk protein allergy (CMPA) occurs commonly in infants. While the long-term efficacy of amino acid formulas for managing CMPA is well-established, there is limited data on the short-term symptom improvement of using amino acid formula (AAF).ObjectiveThis study aimed to determine the short-term effects of managing suspected CMPA in infants aged 6 months and under using a commercial AAF.MethodsHealthcare providers who treated infants with suspected CMPA aged 6 months or younger (n = 104) provided de-identified survey data in this prospective study. Healthcare providers scored symptoms for severity from 0 to 3 (none, low, moderate, severe) before using a commercial AAF at Visit 1 and at Visit 2 (3–6 weeks later).ResultsGastrointestinal (94%), skin (87%), respiratory (86%), and uncategorized symptoms (89%) improved from AAF initiation, and these findings were consistent across different follow-up visit durations.ConclusionThis study is the most extensive prospective analysis conducted in the United States examining the short-term change in suspected CMPA symptoms using an AAF. These findings suggest that AAF may decrease the severity of suspected CMPA symptoms in infants 6 months or younger, often by the next follow-up visit. Further randomized controlled trials are required to confirm these initial findings

    Hydrographic changes in the eastern subpolar North Atlantic during the last deglaciation

    Get PDF
    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Quaternary Science Reviews 29 (2010): 3336-3345, doi:10.1016/j.quascirev.2010.08.013.Millennial-scale climate fluctuations of the last deglaciation have been tied to abrupt changes in the Atlantic Meridional Overturning Circulation (MOC). A key to understanding mechanisms of MOC collapse and recovery is the documentation of upper ocean hydrographic changes in the vicinity of North Atlantic deep convection sites. Here we present new high-resolution ocean temperature and δ18Osw records spanning the last deglaciation from an eastern subpolar North Atlantic site that lies along the flow path of the North Atlantic Current, approaching deep convection sites in the Labrador and Greenland-Iceland-Norwegian (GIN) Seas. High-resolution temperature and δ18Osw records from subpolar Site 980 help track the movement of the subpolar/subtropical front associated with temperature and Atlantic MOC changes throughout the last deglaciation. Distinct δ18Osw minima during Heinrich-1 (H1) and the Younger Dryas (YD) correspond with peaks in ice-rafted debris and periods of reduced Atlantic MOC, indicating the presence of melt water in this region that could have contributed to MOC reductions during these intervals. Increased tropical and subtropical δ18Osw during these periods of apparent freshening in the subpolar North Atlantic suggest a buildup of salt at low latitudes that served as a negative feedback on reduced Atlantic MOC.Support for this research was provided by the U.S. National Science Foundation (JFM and DWO) and a postdoctoral scholarship funded in part by the Gary Comer Science and Education Foundation (HB)

    Diagnostic Accuracy of HPV16 Early Antigen Serology For HPV-Driven Oropharyngeal Cancer is Independent of Age and Sex

    Get PDF
    Funding information: This project was funded in part by NIH/NIDCR R01 DE025712 (Paul Brennan, Brenda Diergaarde and Neil Hayes). The Alcohol-Related Cancers and Genetic Susceptibility Study in Europe (ARCAGE) was funded by the European Commission’s fifth framework program (QLK1-2001-00182), the Italian Association for Cancer Research, Compagnia di San Paolo/FIRMS, Region Piemonte and Padova University (CPDA057222). We thank Dr. Wolfgang Ahrens, PhD (Universität Bremen, Germany) for his support in ARCAGE study. The Carolina Head and Neck Cancer Epidemiology (CHANCE) study was supported in part by the National Cancer Institute (R01-CA90731). The Head and Neck 5000 study was a component of independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research scheme (RP-PG-0707-10034). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. Core funding was also provided through awards from Above and Beyond, University Hospitals Bristol and Weston Research Capability Funding and the NIHR Senior Investigator award to Professor Andy Ness. Human papillomavirus (HPV) serology was supported by a Cancer Research UK Programme Grant, the Integrative Cancer Epidemiology Programme (grant number: C18281/A19169). The University of Pittsburgh head and neck cancer case-control study is supported by US National Institutes of Health grants P50CA097190 and P30CA047904. The MSH-PMH study was supported by Canadian Cancer Society Research Institute and Lusi Wong Programs at the Princess Margaret Hospital Foundation.Peer reviewedPublisher PD

    TEF, Vol. 4 No. 1

    Get PDF
    This is the fourth issue of the annually published literary magazine TEF.https://scholarworks.sfasu.edu/tef/1003/thumbnail.jp

    Global and local sea level during the Last Interglacial: A probabilistic assessment

    Full text link
    The Last Interglacial (LIG) stage, with polar temperatures likely 3-5 C warmer than today, serves as a partial analogue for low-end future warming scenarios. Based upon a small set of local sea level indicators, the Intergovernmental Panel on Climate Change (IPCC) inferred that LIG global sea level (GSL) was about 4-6 m higher than today. However, because local sea levels differ from GSL, accurately reconstructing past GSL requires an integrated analysis of globally distributed data sets. Here we compile an extensive database of sea level indicators and apply a novel statistical approach that couples Gaussian process regression of sea level to Markov Chain Monte Carlo modeling of geochronological errors. Our analysis strongly supports the hypothesis that LIG GSL was higher than today, probably peaking at 6-9 m. Our results highlight the sea level hazard associated with even relatively low levels of sustained global warming.Comment: Preprint version of what has since been published in Natur

    Lower export production during glacial periods in the equatorial Pacific derived from (231Pa/230Th)xs,0 measurements in deep-sea sediments

    Get PDF
    Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 19 (2004): PA4023, doi:10.1029/2003PA000994.The (231Pa/230Th)xs,0 records obtained from two cores from the western (MD97-2138; 1°25′S, 146°24′E, 1900 m) and eastern (Ocean Drilling Program Leg 138 Site 849, 0°11.59′N, 110°31.18′W, 3851 m) equatorial Pacific display similar variability over the last 85,000 years, i.e., from isotopic stages 1 to 5a, with systematically higher values during the Holocene, isotopic stage 3, and isotopic stage 5a, and lower values, approaching the production rate ratio of the two isotopes (0.093), during the colder periods corresponding to isotopic stages 2 and 4. We have also measured the 230Th-normalized biogenic preserved and terrigenous fluxes, as well as major and trace elements concentrations, in both cores. The (231Pa/230Th)xs,0 results combined with the changes in preserved carbonate and opal fluxes at the eastern site indicate lower productivity in the eastern equatorial Pacific during glacial periods. The (231Pa/230Th)xs,0 variations in the western equatorial Pacific also seem to be controlled by productivity (carbonate and/or opal). The generally high (231Pa/230Th)xs,0 ratios (>0.093) of the profile could be due to opal and/or MnO2 in the sinking particles. The profiles of (231Pa/230Th)xs,0 and 230Th-normalized fluxes indicate a decrease in exported carbonate, and possibly opal, during isotopic stages 2 and 4 in MD97-2138. Using 230Th-normalized flux, we also show that sediments from the two cores were strongly affected by sediment redistribution by bottom currents suggesting a control of mass accumulation rates by sediment focusing variability.SP funding for this research was provided by grants from the French Minister of Research and a EURODOC grant of the Re´gion Rhoˆne-Alpes (SAFIR-980065327). SP also gratefully acknowledges the financial support of the WHOI Geology and Geophysics Dept. This work was also supported by a CNRS-NSF grant (SP and KWWS). The contribution of JFM to this study was supported in part by the US NSF and by WHOI OCCI and Mellon awards
    corecore