883 research outputs found
A New Genus of Miniaturized and Pug-Nosed Gecko from South America (Sphaerodactylidae: Gekkota)
Sphaerodactyl geckos comprise five genera distributed across Central and South America and the Caribbean. We estimated phylogenetic relationships among sphaerodactyl genera using both separate and combined analyses of seven nuclear genes. Relationships among genera were incongruent at different loci and phylogenies were characterized by short, in some cases zero-length, internal branches and poor phylogenetic support at most nodes. We recovered a polyphyletic Coleodactylus, with Coleodactylus amazonicus being deeply divergent from the remaining Coleodactylus species sampled. The C. amazonicus lineage possessed unique codon deletions in the genes PTPN12 and RBMX while the remaining Coleodactylus species had unique codon deletions in RAG1. Topology tests could not reject a monophyletic Coleodactylus, but we show that short internal branch lengths decreased the accuracy of topology tests because there were not enough data along these short branches to support one phylogenetic hypothesis over another. Morphological data corroborated results of the molecular phylogeny, with Coleodactylus exhibiting substantial morphological heterogeneity. We identified a suite of unique craniofacial features that differentiate C. amazonicus not only from other Coleodactylus species, but also from all other geckos. We describe this novel sphaerodactyl lineage as a new genus, Chatogekko gen. nov. We present a detailed osteology of Chatogekko, characterizing osteological correlates of miniaturization that provide a framework for future studies in sphaerodactyl systematics and biology
Model-Twin Randomization (MoTR): A Monte Carlo Method for Estimating the Within-Individual Average Treatment Effect Using Wearable Sensors
Temporally dense single-person "small data" have become widely available
thanks to mobile apps and wearable sensors. Many caregivers and self-trackers
want to use these data to help a specific person change their behavior to
achieve desired health outcomes. Ideally, this involves discerning possible
causes from correlations using that person's own observational time series
data. In this paper, we estimate within-individual average treatment effects of
physical activity on sleep duration, and vice-versa. We introduce the model
twin randomization (MoTR; "motor") method for analyzing an individual's
intensive longitudinal data. Formally, MoTR is an application of the g-formula
(i.e., standardization, back-door adjustment) under serial interference. It
estimates stable recurring effects, as is done in n-of-1 trials and single case
experimental designs. We compare our approach to standard methods (with
possible confounding) to show how to use causal inference to make better
personalized recommendations for health behavior change, and analyze 222 days
of Fitbit sleep and steps data for one of the authors.Comment: 27 pages, 2 figures, 5 tables; appendix include
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Intermediate progenitors support migration of neural stem cells into dentate gyrus outer neurogenic niches.
The hippocampal dentate gyrus (DG) is a unique brain region maintaining neural stem cells (NCSs) and neurogenesis into adulthood. We used multiphoton imaging to visualize genetically defined progenitor subpopulations in live slices across key stages of mouse DG development, testing decades old static models of DG formation with molecular identification, genetic-lineage tracing, and mutant analyses. We found novel progenitor migrations, timings, dynamic cell-cell interactions, signaling activities, and routes underlie mosaic DG formation. Intermediate progenitors (IPs, Tbr2+) pioneered migrations, supporting and guiding later emigrating NSCs (Sox9+) through multiple transient zones prior to converging at the nascent outer adult niche in a dynamic settling process, generating all prenatal and postnatal granule neurons in defined spatiotemporal order. IPs (Dll1+) extensively targeted contacts to mitotic NSCs (Notch active), revealing a substrate for cell-cell contact support during migrations, a developmental feature maintained in adults. Mouse DG formation shares conserved features of human neocortical expansion
Evaluación de la transformación del matorral del Parque Nacional de Doñana como medida de gestión y su impacto sobre la comunidad de micromamÃferos.
Una de las principales medidas de gestión que se realizan en el Parque Nacional de Doñana dentro del Plan de manejo del lince (Lynx pardina) y del águila imperial (Aquila adalberti) es el desbroce de matorral, con ob- jeto de crear zonas abiertas de alimentación para el conejo (Oryctolagus cuniculus). Esta medida de gestión está produciendo una profunda modificación en la estructura de la vegetación, y aunque afecta positiva- mente a los conejos, se desconoce su efecto sobre otras especies caracterÃsticas de este hábitat como son los micromamÃferos, cuya comunidad podrÃa estar sufriendo importantes procesos de cambio. En concreto una de las especies más caracterÃsticas de esta comunidad, el lirón careto atlántico, Eliomys quercinus lusitanicus, abundante en el pasado es ahora extremadamente rara, e incluso podrÃa haber desparecido del área. Este estudio tiene como objetivo evaluar el efecto de la eliminación del matorral, mediante quema con- trolada, sobre la comunidad de micromamÃferos. Para ello hemos analizado la riqueza y abundancia es- pecÃficas y la evolución temporal de estos parámetros en parcelas quemadas de diferente antigüedad y en zonas no sometidas a tratamiento. La toma de datos se realizó mediante captura-recaptura en pe- riodos estacionales, desde el verano de 2005 a la primavera de 2007. Los resultados mostraron que la riqueza especÃfica fue muy baja, con tan solo 4 especies capturadas (Mus spretus, Apodemus sylvaticus, Crocidura russula y Eliomys quercinus). La abundancia presentó valo- res muy variables dependiendo de la especie, la época del año y el tipo de parcela; aunque se observa que la especie más abundante es Mus spretus con mucha diferencia sobre las demás. En general, el otoño y el invierno fueron las estaciones con mayor abundancia, y ésta se hace muy escasa durante el verano. La quema controlada del matorral mediterráneo senescente en el Parque Nacional de Doñana favorece la presencia de especies y su abundancia, no tanto en la propia parcela sometida a tratamiento, como en el matorral que la bordea. Mus es la especie dominante en todos los ambientes. Apodemus muestra mecanis- mos de evitación espacial y temporal con Mus. Eliomys quercinus no ha desaparecido de Doñana, aunque su abundancia es escasÃsima y aparece asociada al borde de parcelas quemadas de cuatro años de antigüedad. El proceso de colonización de las parcelas quemadas parece alcanzar la abundancia más alta y la mayor riqueza especÃfica a los tres-cuatro años tras la quema. Esta colonización no sigue una pauta regular en el tiempo, sino que se encuentra condicionada por otros factores, entre los que parece encontrarse la pre- cipitación anual.Peer Reviewe
China's transboundary hydropower development at home and abroad:Exploring the regulatory interface between international water law and international economic law
China, located upstream on most of the major transboundary waters shared with vast populations across Asia, is heavily invested in developing hydropower at home and abroad. Some of this hydropower development involves freshwaters that cross national borders raising complex issues in international law, a situation exacerbated by growing economic, environmental, and regional security pressures. In such a context, where conflicts-of-use are almost certain to arise, it is essential to understand the rules that apply so as to enhance opportunities for enhanced transboundary water cooperation. This paper examines the rules of international water law and international economic law that apply to transboundary hydropower development, with a focus on China as one of the key actors in this field. The aim is to examine the regulatory interface of relevant legal frameworks with a focus on China's approach to transboundary hydropower development at home and abroad. While international economic—and more specifically international investment law—is not directly concerned with international water law, host states and foreign investors must be informed, and take into account, the legal obligations governing transboundary waters. China's position as a major water user (at home) and significant investor (abroad) on transboundary waters, makes it a unique case study for exploring the rules of international law that apply in two different regulatory settings. The work examines the rules of law in each of these domains and reveals the inapparent linkages across these seemingly unconnected areas of international regulation.</p
Exploring Li-ion conductivity in cubic, tetragonal and mixed-phase Al-substituted Li7La3Zr2O12 using atomistic simulations and effective medium theory
Garnet Li7La3Zr2O12 (LLZO) is a promising solid electrolyte candidate for solid-state Li-ion batteries, but at room temperature it crystallizes in a poorly Li-ion conductive tetragonal phase. To this end, partial substitution of Li+ by Al3+ ions is an effective way to stabilize the highly conductive cubic phase at room temperature. Yet, fundamental aspects regarding this aliovalent substitution remain poorly understood. In this work, we use molecular dynamics and advanced hybrid Monte Carlo methods for systematic study of the room temperature Li-ion diffusion in tetragonal and cubic LLZO to shed light on important open questions. We find that Al substitution in tetrahedral sites of the tetragonal LLZO allows previously inaccessible sites to become available, which enhances Li-ion conductivity. In contrast, in the cubic phase Li-ion diffusion paths become blocked in the vicinity of Al ions, resulting in a decrease of Li-ion conductivity. Moreover, combining the conductivities of individual phases through an effective medium approximation allowed us to estimate the conductivities of cubic/tetragonal phase mixtures that are in good agreement with those reported in several experimental works. This suggests that phase coexistence (due to phase equilibrium or gradients in Al content within a sample) could have a significant impact on the conductivity of Al-substituted LLZO, particularly at low contents of Al3+. Overall, by making a thorough comparison with reported experimental data, the theoretical study and simulations of this work advance our current understanding of Li-ion mobility in Al-substituted LLZO garnets and might guide future in-depth characterization experiments of this relevant energy storage material.MINECO ENE2016-81020-R.
SGI/IZO-SGIker UPV/EHU.
the i2BASQUE academic network.
Barcelona Supercomputer Center (QCM-2016-450 3-0002)
Lesiones esqueléticas asociadas al sÃndrome de Papillon-Lefèvre
Se presentan dos casos de SÃndrome de Papillon-Lefèvre que se asocian
a osteolisis espontánea de los metatarsianos y las falanges de los dedos de
los pies. Esta asociación no habÃa sido descrita con anterioridad.Two case s of Papillon-Lefèvre syndrome associated with spontaneous
osteolysis of the phalanges and metatarsals of the toe s are
presented. This association has not been previously reported
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