1,161 research outputs found

    Standing-stock Biomass and Diversity of Caulerpa (Chlorophyta) in Solong-on, Siquijor Island, Philippines

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    Caulerpa species growing on shallow to deep waters are considered to be both economically nuisance and important. Although invasive in the temperate regions, Caulerpa species mainly C. racemosa and C. lentillifera (lato) are harvested and consumed as food, especially in the Philippines. Caulerpa communities in Solong-on, Siquijor are one of the sources for export to neighbouring municipalities. This study aimed to determine the present standing stock biomass, percent cover and diversity of Caulerpa in Solong-on, as well as to determine the environmental parameters that may affect its abundance and diversity. The results showed a total of eight species of Caulerpa were identified in the shallow Caulerpa community in Solong-on, Siquijor. The highest standing stock biomass was obtained by C. cupressoides with mean biomass of 26.16±2.44 (SE) g dry wt m-2, whereas C. microphysa has the least standing stock biomass with an average mean of 9.16±0.26 g dry wt m-2. In general, the total standing stock biomass for all species obtained throughout the sampling period was 132.57±2.06 g dry wt m-2. Shannon-Wiener diversity index (H') ranged from 1.7-2 suggesting a relatively diverse Caulerpa community. Canonical correspondence analysis (CCA) revealed that temperature and type of substrate were the main drivers of Caulerpa biomass

    Éthique de la recherche d’ADN sur les vestiges humains: cinq lignes directrices applicables à l'échelle globale.

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    Nous sommes un groupe d'archéologues, d’anthropologues, de conservateurs et de généticiens de différentes origines et représentant 31 pays. Nous nous sommes rencontrés en novembre 2020 lors d'une table ronde en ligne dédiée à l'éthique de la recherche d’ADN ancien. Nous avons alors convenu de la nécessité de lignes directrices éthiques applicables à l'échelle mondiale. Les recommandations publiées récemment et développées dans le cadre de recherches d’ADN sur des vestiges humains d’Amérique du Nord ne s’avèrent pas généralisables à d’autres régions du monde. Suite à l’analyse de divers contextes, nous proposons ici des lignes directrices que nous pensons être applicables partout dans le monde. Ces lignes directrices sont les suivantes : 1) les chercheurs doivent s'assurer que les règlements s’appliquant dans les lieux où ils travaillent ainsi que dans les lieux d’où proviennent les vestiges humains sont bien respectés ; 2) les chercheurs doivent préparer un programme de recherche détaillé avant de commencer toute étude ; 3) les chercheurs doivent minimiser les dommages causés aux vestiges humains ; 4) les chercheurs doivent s'assurer que les données seront disponibles après la publication pour permettre un réexamen critique des résultats scientifiques; et 5) les chercheurs doivent échanger avec toutes les parties impliquées dès le début de l’étude et respecter leurs points de vue. Nous nous engageons à respecter ces directives et nous souhaitons qu’elles contribuent au renforcement de la pratique éthique de notre champ de recherche.NWOVI.C.191.070Human Origin

    More arrows in the ancient DNA quiver: use of paleoepigenomes and paleomicrobiomes to investigate animal adaptation to environment

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    Whether and how epigenetic mechanisms and the microbiome play a role in mammalian adaptation raised considerable attention and controversy, mainly because they have the potential to add new insights into the Modern Synthesis. Recent attempts to reconcile neo-Darwinism and neo-Lamarckism in a unified theory of molecular evolution give epigenetic mechanisms and microbiome a prominent role. However, supporting empirical data is still largely missing. Because experimental studies using extant animals can hardly be done over evolutionary timescales, we propose that advances in ancient DNA techniques provide a valid alternative. In this piece, we evaluate: (1) the possible roles of epigenomes and microbiomes in animal adaptation; (2) advances in the retrieval of paleoepigenome and paleomicrobiome data using ancient DNA techniques; and (3) the plasticity of either and interactions between the epigenome and the microbiome, while emphasising that it is essential to take both into account, as well as the underlying genetic factors that may confound the findings. We propose that advanced ancient DNA techniques should be applied to a wide range of past animals, so novel dynamics in animal evolution and adaption can be revealed.Yichen Liu, Laura S Weyrich, Bastien Llama

    Did COVID-19 policies have the same effect on covid-19 incidence among women and men? Evidence from Spain and Switzerland

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    Objective: This study aimed to investigate how COVID-19 prevention policies influenced the COVID-19 incidence in men and women. Methods: We conducted a retrospective longitudinal study using the Swiss Federal Office of Public Health and the Spanish Ministry of Health surveillance data for February 2020-June 2021 to explore sex and age differences in COVID-19 cases and testing. The female-male incidence rate ratios (IRR) were estimated for each week of the pandemic. We complemented our analysis with qualitative information on relevant containment measures in each country. Results: In Switzerland and in Spain, there was an excess of cases in women of 20-59 years old and 80+. This excess of cases was significant during the waves of the pandemic in both countries. In Switzerland, the biggest difference was observed for the age group 20-29, reaching an excess of 94% of cases compared to men during the first wave of COVID-19 (March-May 2020). The excess of cases in women was greater in Spain than in Switzerland, where it reached 159% for women aged 20-29 during the first wave (March-June 2020). In both countries, the age groups 60-79 had a significant excess of cases in men during the pandemic. Conclusion: COVID-19 public health policies affect men and women in different ways. Our findings highlight the importance of gender-sensitive responses to address a public health crisis

    A multidisciplinary review of the Inka imperial resettlement policy and implications for future investigations

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    The rulers of the Inka empire conquered approximately 2 million km² of the South American Andes in just under 100 years from 1438-1533 CE. Inside the empire, the elite conducted a systematic resettlement of the many Indigenous peoples in the Andes that had been rapidly colonised. The nature of this resettlement phenomenon is recorded within the Spanish colonial ethnohistorical record. Here we have broadly characterised the resettlement policy, despite the often incomplete and conflicting details in the descriptions. We then review research from multiple disciplines that investigate the empirical reality of the Inka resettlement policy, including stable isotope analysis, intentional cranial deformation morphology, ceramic artefact chemical analyses and genetics. Further, we discuss the benefits and limitations of each discipline for investigating the resettlement policy and emphasise their collective value in an interdisciplinary characterisation of the resettlement policy.Roberta Davidson, Lars Fehren-Schmitz and Bastien Llama

    Ensayos de hormigones fabricados con polvo de corcho

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    [ES] Este trabajo de investigación tiene por objeto conocer algunas propiedades físicas y mecánicas de un hormigón elaborado en laboratorio, adicionándole diversas proporciones de polvo de corcho. Las propiedades del material resultante, si bien carecen de la resistencia mecánica que caracteriza al hormigón, parecen interesantes para su uso en ciertas aplicaciones de la ingeniería agronómica tales como en la fabricación de piezas para solados de parques infantiles y jardines, o en los cubículos de ciertas construcciones ganaderas, extremos que es preciso analizar y comprobar

    Chromosome Y variants from different inbred mouse strains are linked to differences in the morphologic and molecular responses of cardiac cells to postpubertal testosterone

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    Background: We have reported previously that when chromosome Y (chrY) from the mouse strain C57BL/6J (ChrYC57) was substituted for that of A/J mice (ChrYA), cardiomyocytes from the resulting "chromosome substitution" C57BL/6J-chrYA strain were smaller than that of their C57BL/6J counterparts. In reverse, when chrYA from A/J mice was substituted for that of chrYC57, cardiomyocytes from the resulting A/J-chrYC57 strain were larger than in their A/J counterparts. We further used these strains to test whether: 1) the origin of chrY could also be linked to differences in the profile of gene expression in the hearts of adult male mice, and 2) post-pubertal testosterone could play a role in the differential morphologic and/or molecular effects of chrYC57 and chrYA. Results: The increased size of cardiomyocytes from adult male C57BL/6J mice compared to C57BL/6JchrYA resulted from the absence of hypertrophic effects of post-pubertal testosterone on cells from the latter strain. However, gene profiling revealed that the latter effect could not be explained on the basis of an insensitivity of cells from C57BL/6J-chrYA to androgens, since even more cardiac genes were affected by post-pubertal testosterone in C57BL/6J-chrYA hearts than in C57BL/6J. By testing for interaction between the effects of surgery and strain, we identified 249 "interaction genes" whose expression was affected by post-pubertal testosterone differentially according to the genetic origin of chrY. These interaction genes were found to be enriched within a limited number of signaling pathways, including: 1) p53 signaling, which comprises the interacting genes Ccnd1, Pten and Cdkn1a that are also potential coregulators of the androgen receptors, and 2) circadian rhythm, which comprises Arntl/Bmal1, which may in turn regulate cell growth via the control of Cdkn1a. Conclusion: Although post-pubertal testosterone increased the size of cardiomyocytes from male C56BL/6J mice but not that from their C57BL/6J-chrYA counterparts, it affected gene expression in the hearts from both strains. However, several cardiac genes responded to post-pubertal testosterone in a strict strain-selective manner, which provides possible mechanisms explaining how chrY may, in part via interference with androgen regulatory events, be linked to morphologic differences of cardiac cells of adult male mice.Bastien Llamas, Ricardo A Verdugo, Gary A Churchill and Christian F Descheppe

    Using ancient DNA analysis and radiocarbon dating to determine the provenance of an unusual whaling artifact

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    Natural history collections provide a critical temporal view of past biodiversity and are instrumental in the study of extinct populations. However, the value of historical specimens relies on correct species identification, collection date and collection locality. The Australian National Maritime Museum (ANMM) holds an unusual artifact – an electric lamp made from a dried whale penis – with unknown age, species-of-origin and collection locality. We used ancient DNA methods to generate a partial mitochondrial DNA (mtDNA) genome sequence to establish the identity and provenance of the whale, and accelerator mass spectrometry (AMS) radiocarbon dating to determine the approximate year of death. Mitochondrial DNA sequences from the 16S rRNA gene and the control region indicate that the specimen belonged to a sperm whale (Physeter macrocephalus) and a modern radiocarbon age suggests it was collected post-1950s. We were unable to determine the collection locality of the whale due to the very broad geographic distribution of its mtDNA haplotype. Our results suggest the specimen was possibly collected as a souvenir during post-war whaling, where nearly 30,000 male sperm whales were killed annually. This study supports and extends previous research that applies ancient DNA and radiocarbon dating techniques to enhance the value of natural history collections, by identifying the species-of-origin and age of historical specimens.Caitlin Mudge, Rebecca Dallwitz, Bastien Llamas and Jeremy J. Austi
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