51 research outputs found

    Slow and steady wins the race: Diversification rate is independent from body size and lifestyle in Malagasy skinks (Squamata: Scincidae: Scincinae)

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    Research data are available on the Mendeley Data platform (https://doi.org/10.17632/xfx2yhw949.2), which include datasets, input files and R scripts of the analyses.Appendix A. Supplementary material Supplementary data to this article can be found online at https://doi. org/10.1016/j.ympev.2022.107635Most of the unique and diverse vertebrate fauna that inhabits Madagascar derives from in situ diversification from colonisers that reached this continental island through overseas dispersal. The endemic Malagasy Scincinae lizards are amongst the most species-rich squamate groups on the island. They colonised all bioclimatic zones and display many ecomorphological adaptations to a fossorial (burrowing) lifestyle. Here we propose a new phylogenetic hypothesis for their diversification based on the largest taxon sampling so far compiled for this group. We estimated divergence times and investigated several aspects of their diversification (diversification rate, body size and fossorial lifestyle evolution, and biogeography). We found that diversification rate was constant throughout most of the evolutionary history of the group, but decreased over the last 6–4 million years and independently from body size and fossorial lifestyle evolution. Fossoriality has evolved from fully quadrupedal ancestors at least five times independently, which demonstrates that even complex morphological syndromes – in this case involving traits such as limb regression, body elongation, modification of cephalic scalation, depigmentation, and eyes and ear-opening regression – can evolve repeatedly and independently given enough time and eco-evolutionary advantages. Initial diversification of the group likely occurred in forests, and the divergence of sand-swimmer genera around 20 Ma appears linked to a period of aridification. Our results show that the large phenotypic variability of Malagasy Scincinae has not influenced diversification rate and that their rich species diversity results from a constant accumulation of lineages through time. By compiling large geographic and trait-related datasets together with the computation of a new time tree for the group, our study contributes important insights on the diversification of Malagasy vertebrates.Portuguese National Funds through FCT (Fundação para a Ciência e a Tecnologia) supported this work with the projects UIDP/50027/2020 and PTDC/BIA-EVL/31254/2017Contract grant to AC [2020.00823.CEECIND/CP1601/CT0003PD/BD/128493/2017SFRH/BD/102495/2014SFRH/BPD/111015/2015Agencia Española de Investigación, with a Juan de la Cierva-Formación grant [FCI2019-039443-I/AEI/10.13039/501100011033]Swedish Research Council [2019-05191]Swiss National Science Foundation [PCEFP3_187012]Swedish Research Council [VR: 2019-04739

    Uncertainty in calibration and characterisation of pyranometers

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    This work quantifies the uncertainties of thermoelectric pyranometer measurements made with different calibration methods. Measurement campaigns supported both the evaluation of pyranometer calibrations and newly proposed approaches to characterise the pyranometers in indoor and outdoor conditions. Estimated uncertainties were then applied to a year-long irradiance dataset to evaluate the impact on the assessment of the annual solar irradiation. This study highlights the differences seen when calibrating pyranometers under different conditions and procedures. Such deeper insight of pyranometers response aims ultimately to assist the integration of short-term (pyranometers) and long-term (satellite-based) data to a more accurate evaluation of PV energy yield

    Resolving a taxonomic and nomenclatural puzzle in mantellid frogs: synonymization of Gephyromantis azzurrae with G. corvus, and description of Gephyromantis kintana sp. nov. from the Isalo Massif, western Madagascar

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    The genus Gephyromantis belongs to the species-rich family Mantellidae and is currently divided in six subgenera. Among these is the subgenus Phylacomantis, which currently includes four described species: Gephyromantis pseudoasper, G. corvus, G. azzurrae, and G. atsingy. The latter three species are distributed in western Madagascar, and two of them (G. azzurrae and G. corvus) occur in the Isalo Massif. Based on the analysis of molecular data (a fragment of the 16S rRNA gene), morphological inspection of museum specimens, and photographic comparisons, G. azzurrae is synonymised with G. corvus and the second Phylacomantis lineage of Isalo is described as G. kintana sp. nov. This medium-sized frog species (adult snout-vent length 35–44 mm) is assigned to this subgenus according to genetic and morphological similarities to the other known species of Phylacomantis. Gephyromantis kintana sp. nov. is known only from the Isalo Massif, while new records for G. corvus extend its range to ca. 200 km off its currently known distribution. These two taxa seem to occur in syntopy in at least one locality in Isalo, and the easiest way to distinguish them is the inspection of the ventral colouration, dark in G. corvus and dirty white in G. kintana.info:eu-repo/semantics/publishedVersio

    Uncovering the herpetological diversity of small forest fragments in south-eastern Madagascar (Haute Matsiatra)

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    Madagascar has historically suffered from high fragmentation of forested habitats, often leading to biodiversity loss. Neverthless, forest fragments still retain high levels of biological diversity. The Haute Matsiatra Region (south-eastern Madagascar) hosts the renowned Andringitra National Park and several surrounding isolated forest fragments embedded in a matrix of human-dominated landscape. During a herpetological survey conducted in the Region, we visited a total of 25 sites. We applied a molecular taxonomic approach to identify the collected material and generate new reference sequences to improve the molecular identification of Malagasy herpetofauna. We identified a total of 28 amphibian and 38 squamate taxa and provided a systematic account for each one of them. Nine of the identified taxa are candidate species, amongst which one was newly identified. We extended the known distributional range of 21 taxa (nine amphibians and 12 squamates). Although the largest forest fragments hold a higher number of species, we also detected a relatively high herpetological diversity in small patches. Our results highlight the importance of investigating small forest fragments to contribute to a better understanding of the patterns of diversity and distribution of the amphibians and reptiles of Madagascar.info:eu-repo/semantics/publishedVersio

    Lack of Dystrophin Affects Bronchial Epithelium in mdx Mice

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    Mild exercise training may positively affect the course of Duchenne Muscular Dystrophy (DMD). Training causes mild bronchial epithelial injury in both humans and mice, but no study assessed the effects of exercise in mdx mice, a well known model of DMD. The airway epithelium was examined in mdx (C57BL/10ScSn-Dmdmdx) mice, and in wild type (WT, C57BL/10ScSc) mice either under sedentary conditions (mdx-SD, WT-SD) or during mild exercise training (mdx-EX, WT-EX). At baseline, and after 30 and 45 days of training (5 d/wk for 6 weeks), epithelial morphology and markers of regeneration, apoptosis, and cellular stress were assessed. The number of goblet cells in bronchial epithelium was much lower in mdx than in WT mice under all conditions. At 30 days, epithelial regeneration (PCNA positive cells) was higher in EX than SD animals in both groups; however, at 45 days, epithelial regeneration decreased in mdx mice irrespective of training, and the percentage of apoptotic (TUNEL positive) cells was higher in mdx-EX than in WT-EX mice. Epithelial expression of HSP60 (marker of stress) progressively decreased, and inversely correlated with epithelial apoptosis (r=-0.66, P=0.01) only in mdx mice. Lack of dystrophin in mdx mice appears associated with defective epithelial differentiation, and transient epithelial regeneration during mild exercise training. Hence, lack of dystrophin might impair repair in bronchial epithelium, with potential clinical consequences in DMD patients

    Assessment and improvement of thermoelectric pyranometer measurements

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    This work evaluates the variability of thermoelectric pyranometer calibration values seen when using different calibration methods and practices. The pyranometer calibration ISO 9847:1992 standard leaves many procedural details to the user’s discretion. The variability resulting from different interpretations influences PV system performance monitoring and energy yield modelling. Improved methods and more robust standardisation are therefore needed to reduce uncertainty in field-deployed thermoelectric pyranometers and consequently reduce risk in PV system energy yield assessment. This paper investigates the variability induced by relaxed calibration procedures defined in the standard Furthermore, it proposes indoor procedures for the characterisation of pyranometer response to incidence angle and temperature which have not yet been defined in the standards. Uncertainty of calibration factors including under high angles of incidence and a few cloudy data series from outdoor methods were found to be up to 2.08%, compared with 1.4% stated by the manufacturer. Uncertainty increases up to 4.73% when reference and test sensors are of different types. Results of indoor calibration procedures agreed to within 1.21% even when calibrating multiple sensors at the same time. The instability of the irradiance source contributed more to the overall uncertainty than the selection of the procedure. The angular response of the devices tested was close to the prescribed limits [1]

    A New Neurorehabilitative Postsurgery Intervention for Facial Palsy Based on Smile Observation and Hand-Mouth Motor Synergies

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    Objective. To perform a preliminary test of a new rehabilitation treatment (FIT-SAT), based on mirror mechanisms, for gracile muscles after smile surgery. Method. A pre- and postsurgery longitudinal design was adopted to study the efficacy of FIT-SAT. Four patients with bilateral facial nerve paralysis (Moebius syndrome) were included. They underwent two surgeries with free muscle transfers, one year apart from each other. The side of the face first operated on was rehabilitated with the traditional treatment, while the second side was rehabilitated with FIT-SAT. The FIT-SAT treatment includes video clips of an actor performing a unilateral or a bilateral smile to be imitated (FIT condition). In addition to this, while smiling, the participants close their hand in order to exploit the overlapped cortical motor representation of the hand and the mouth, which may facilitate the synergistic activity of the two effectors during the early phases of recruitment of the transplanted muscles (SAT). The treatment was also aimed at avoiding undesired movements such as teeth grinding. Discussion. Results support FIT-SAT as a viable alternative for smile rehabilitation after free muscle transfer. We propose that the treatment potentiates the effect of smile observation by activating the same neural structures responsible for the execution of the smile and therefore by facilitating its production. Closing of the hand induces cortical recruitment of hand motor neurons, recruiting the transplanted muscles, and reducing the risk of associating other unwanted movements such as teeth clenching to the smile movements
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