317 research outputs found
Ecoregional and temporal dynamics of dugong habitat use in a complex coral reef lagoon ecosystem
Mobile marine species display complex and nonstationary habitat use patterns that require understanding to design effective management measures. In this study, the spatio-temporal habitat use dynamics of the vulnerable dugong (Dugong dugon) were modelled from 16 satellite-tagged individuals in the coral reef lagoonal ecosystems of New Caledonia, South Pacific. Dugong residence time was calculated along the interpolated tracks (9371 hourly positions) to estimate intensity of use in three contrasting ecoregions, previously identified through hierarchical clustering of lagoon topographic characteristics. Across ecoregions, differences were identified in dugong spatial intensity of use of shallow waters, deeper lagoon waters and the fore-reef shelf outside the barrier reef. Maps of dugong intensity of use were predicted from these ecological relationships and validated with spatial density estimates derived from aerial surveys conducted for population assessment. While high correlation was found between the two datasets, our study extended the spatial patterns of dugong distribution obtained from aerial surveys across the diel cycle, especially in shallow waters preferentially used by dugongs at night/dusk during high tide. This study has important implications for dugong conservation and illustrates the potential benefits of satellite tracking and dynamic habitat use modelling to inform spatial management of elusive and mobile marine mammals
Set-Theoretic Types for Polymorphic Variants
Polymorphic variants are a useful feature of the OCaml language whose current
definition and implementation rely on kinding constraints to simulate a
subtyping relation via unification. This yields an awkward formalization and
results in a type system whose behaviour is in some cases unintuitive and/or
unduly restrictive. In this work, we present an alternative formalization of
poly-morphic variants, based on set-theoretic types and subtyping, that yields
a cleaner and more streamlined system. Our formalization is more expressive
than the current one (it types more programs while preserving type safety), it
can internalize some meta-theoretic properties, and it removes some
pathological cases of the current implementation resulting in a more intuitive
and, thus, predictable type system. More generally, this work shows how to add
full-fledged union types to functional languages of the ML family that usually
rely on the Hindley-Milner type system. As an aside, our system also improves
the theory of semantic subtyping, notably by proving completeness for the type
reconstruction algorithm.Comment: ACM SIGPLAN International Conference on Functional Programming, Sep
2016, Nara, Japan. ICFP 16, 21st ACM SIGPLAN International Conference on
Functional Programming, 201
Quantifying humpback whale song sequences to understand the dynamics of song exchange at the ocean basin scale
Humpback whales have a continually evolving vocal sexual display, or "song," that appears to undergo both evolutionary and "revolutionary" change. All males within a population adhere to the current content and arrangement of the song. Populations within an ocean basin share similarities in their songs; this sharing is complex as multiple variations of the song (song types) may be present within a region at any one time. To quantitatively investigate the similarity of song types, songs were compared at both the individual singer and population level using the Levenshtein distance technique and cluster analysis. The highly stereotyped sequences of themes from the songs of 211 individuals from populations within the western and central South Pacific region from 1998 through 2008 were grouped together based on the percentage of song similarity, and compared to qualitatively assigned song types. The analysis produced clusters of highly similar songs that agreed with previous qualitative assignments. Each cluster contained songs from multiple populations and years, confirming the eastward spread of song types and their progressive evolution through the study region. Quantifying song similarity and exchange will assist in understanding broader song dynamics and contribute to the use of vocal displays as population identifiers
Les effets de la canicule et de la sĂ©cheresse sur la forĂȘt de la Massane (PyrĂ©nĂ©es-Orientales)
Depuis 2003, la réserve naturelle de la Massane subit les effets des canicules et des sécheresses répétées. De nombreux travaux ont été menés sur le site, qui ont permis de suivre l'impact de ces phénomÚnes sur les écosytÚmes
Demographic and physiological signals of reproductive events in humpback whales on a southwest pacific breeding ground
The field of marine mammal conservation has dramatically benefited from the rapid advancement of methods to assess the reproductive physiology of individuals and populations from steroid hormones isolated from minimally invasive skin-blubber biopsy samples. Historically, this vital information was only available from complete anatomical and physiological investigations of samples collected during commercial or indigenous whaling. Humpback whales (Megaptera novaeangliae) are a migratory, cosmopolitan species that reproduce in warm, low-latitude breeding grounds. New Caledonia is seasonally visited by a small breeding sub-stock of humpback whales, forming part of the endangered Oceania subpopulation. To better understand the demographic and seasonal patterns of reproductive physiology in humpback whales, we quantified baseline measurements of reproductive hormones (progesterone â P4, testosterone - T, and 17ÎČ-estradiol â E2) using an extensive archive of skin-blubber biopsy samples collected from female humpback whales in New Caledonia waters between 2016-2019 (n = 194). We observed significant differences in the P4, T, and E2 concentrations across different demographic groups of female humpback whales, and we described some of the first evidence of the endocrine patterns of estrus in live free-ranging baleen whales. This study is fundamental in its methodological approach to a wild species that has a global distribution, with seasonally distinct life histories. This information will assist in monitoring, managing, and conserving this population as global ecological changes continue to occur unhindered.Peer reviewe
Efficacy and Safety of 0.1% Cyclosporine a Cationic Emulsion in the Treatment of Severe Dry Eye Disease: A Multicenter Randomized Trial:
PurposeThe SANSIKA study was conducted to assess the treatment effect of 0.1% cyclosporine A cationic emulsion (CsA CE) eye drops on signs and symptoms of patients with severe dry eye disease (DED)..
A pan-cetacean MHC amplicon sequencing panel developed and evaluated in combination with genome assemblies
This study was funded by a Royal Society Research Grants for Research Fellows (RGF\R1\181014) to E.C.G. E.C.G. is funded by a Royal Society University Research Fellowship (UF160081 & URF\R\221020). F.E. is supported by a University of St Andrews School of Biology Ph.D. scholarship and a Royal Society Research Fellows Enhancement Award (RGF\EA\180213 to E.C.G). E.L.C. is funded by a Rutherford Discovery Fellowship from the Royal Society of New Zealand Te ApÄrangi.The major histocompatibility complex (MHC) is a highly polymorphic gene family that is crucial in immunity, and its diversity can be effectively used as a fitness marker for populations. Despite this, MHC remains poorly characterised in non-model species (e.g., cetaceans: whales, dolphins and porpoises) as high gene copy number variation, especially in the fast-evolving class I region, makes analyses of genomic sequences difficult. To date, only small sections of class I and IIa genes have been used to assess functional diversity in cetacean populations. Here, we undertook a systematic characterisation of the MHC class I and IIa regions in available cetacean genomes. We extracted full-length gene sequences to design pan-cetacean primers that amplified the complete exon2 from MHC class I and IIa genes in one combined sequencing panel. We validated this panel in 19 cetacean species and described 354 alleles for both classes. Furthermore, we identified likely assembly artefacts for many MHC class I assemblies based on the presence of class I genes in the amplicon data compared to missing genes from genomes. Finally, we investigated MHC diversity using the panel in 25 humpback and 30 southern right whales, including four paternity trios for humpback whales. This revealed copy-number variable class I haplotypes in humpback whales, which is likely a common phenomenon across cetaceans. These MHC alleles will form the basis for a cetacean branch of the Immuno-Polymorphism Database (IPD-MHC), a curated resource intended to aid in the systematic compilation of MHC alleles across several species, to support conservation initiatives.Peer reviewe
Experimental study of a liquid Xenon PET prototype module
A detector using liquid Xenon in the scintillation mode is studied for
Positron Emission Tomography (PET). The specific design aims at taking full
advantage of the liquid Xenon properties. It does feature a promising
insensitive to any parallax effect. This work reports on the performances of
the first LXe prototype module, equipped with a position sensitive PMT
operating in the VUV range (178 nm).Comment: Proc. of the 7th International Workshops on Radiation Imaging
Detectors (IWORID-7), Grenoble, France 4-7 July 200
Usages et biodiversitĂ© dans les forĂȘts mĂ©diterranĂ©ennes - L'exemple du massif des AlbĂšres (PyrĂ©nĂ©es-Orientales) -
De tout temps, la forĂȘt mĂ©diterranĂ©enne a Ă©tĂ© pourvoyeuse de ressources pour les sociĂ©tĂ©s humaines. Ces ressources Ă©taient exploitĂ©es selon des âdroits d'usagesâ prĂ©cis. Le pacage du bĂ©tail en forĂȘt fait partie des usages qui se maintiennent encore localement mĂȘme si cette activitĂ© a subi un fort dĂ©clin sur les rives nord de la MĂ©diterranĂ©e occidentale depuis le milieu du XIXe siĂšcle. Cette activitĂ© pastorale pose cependant la question de son influence sur le milieu forestier, notamment en termes de rĂ©gĂ©nĂ©ration forestiĂšre et de maintien de la biodiversitĂ©. Le massif des AlbĂšres, dans les PyrĂ©nĂ©es-Orientales, fait partie de ces moyennes montagnes mĂ©diterranĂ©ennes oĂč le sylvopastoralisme perdure. Ce massif abrite Ă©galement une riche biodiversitĂ© comme en tĂ©moignent les rĂ©sultats des inventaires rĂ©alisĂ©s au sein de la RĂ©serve naturelle de la Massane, situĂ©e au cĆur des AlbĂšres. La prĂ©sence de troupeaux domestiques et lâexpression dâune riche biodiversitĂ© tĂ©moignent dâune coexistence possible entre diffĂ©rents enjeux au sein dâun mĂȘme territoire
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