Alpine endemic spiders shed light on the origin and evolution of subterranean species

We designed a comparative study to unravel the phylogeography of two Alpine endemic spiders characterized by a different degree of adaptation to subterranean life: Troglohyphantes vignai (Araneae, Linyphiidae) and Pimoa rupicola (Araneae, Pimoidae), the latter showing minor adaptation to hypogean life. We sampled populations of the model species in caves and other subterranean habitats across their known geographical range in the Western Alps. By combining phylogeographic inferences and Ecological Niche Modeling techniques, we inferred the biogeographic scenario that led to the present day population structure of the two species. According to our divergent time estimates and relative uncertainties, the isolation of T. vignai and P. rupicola from their northern sister groups was tracked back to Middle-Late Miocene. Furthermore, the fingerprint left by Pleistocene glaciations on the population structure revealed by the genetic data, led to the hypothesis that a progressive adaptation to subterranean habitats occurred in T. vignai, followed by strong population isolation. On the other hand, P. rupicola underwent a remarkable genetic bottleneck during the Pleistocene glaciations, that shaped its present population structure. It seems likely that such shallow population structure is both the result of the minor degree of specialization to hypogean life and the higher dispersal ability characterizing this species. The simultaneous study of overlapping spider species showing different levels of adaptation to hypogean life, disclosed a new way to clarify patterns of biological diversification and to understand the effects of past climatic shift on the subterranean biodiversity

Shape matters: relevance of carapace for brachyuran crab invaders

The increasing trend of biological invasions is one of the most concerning threats for ecosystems functioning. The identification of optimal characters determining the invasive potential of nonnative species has always been a challenge in conservation studies. Morphological features can be used as a good proxy to address the invasive success in fish species, assuming that anatomical differences in comparison to native species can provide to newcomers ecological opportunities increasing their probability to become successful. Considering this, the present study constitutes the first applicative attempt of a model based on geometric morphometrics to demonstrate the importance of the carapace shape in the invasive ability in marine decapod crustaceans. The study was performed on the native brachyuran community of Alfacs Bay, in the Ebro Delta, the largest estuarine zone along the north-western Mediterranean, in which two recently established non-native crab species coexist: Dyspanopeus sayi and Callinectes sapidus. Results suggested that invaders with extreme carapace traits located peripherally in the community morphospace, such as C. sapidus, usually possess ecological advantages contributing to understand their success. Conversely, intermediate morphologies within the morphospace, such as D. sayi, imply ecological overlapping with native species reducing their community relevance. Besides, we also assessed the effect on the community morphospace of a hypothetical future invasive event from another crab species (Portunus segnis) with high probabilities to also colonize the community. Our outcomes confirm that the morphometric approach could be an alternative tool for assessing the potential ability of invasive crab species. However, further studies at different spatial and temporal scales, including additional traits and quantitative data from invasions, would be necessary to confirm the efficacy and usefulness of the methodology.Postprint2,89

Selección de puntos homólogos (landmarks) y equidistantes (semilandmarks) en peces para análisis de morfometría geométrica: un estudio comparativo basado en métodos analíticos

We applied and compared three different sets of landmarks and semilandmarks commonly used in studies of fish assemblages to identify a standardized method of landmark selection that includes the maximum amount of morphological information of species. The different landmark-based methods used produced differences regarding the distribution of case-study species within the morphospace. We suggest that adding landmarks and semilandmarks that provide more specific information about anatomical structures with important roles in the biology of species, such as transformed fins or sensory organs, contributes to a clearer differentiation of species within the morphospace and a better interpretation of their occupancy. In addition, three types of method were used to establish how species are distributed within morphospace. The results demonstrated that aggregation points methods, including analyses based on quadrants or distances, are more appropriate for this purpose than indices of morphological disparity. The results also confirmed that although numerical methods are needed to test the statistical significance of outcomes, graphical methods provide a more intuitive interpretation of morphospace occupancy. The kernel density and Gabriel graph were useful to infer the morphospace zone where species are more densely grouped, improving the knowledge of space occupancy and structural complexity of fish assemblages.En el presente estudio se compara la estructura de una comunidad de peces a partir del análisis morfológico de puntos homólogos (landmarks) y equidistantes (semilandmarks) en las especies de dicha comunidad. Para este propósito, se utilizaron tres metodologías distintas descritas en la literatura a la hora de definir dichos puntos con el fin de identificar cuál de ellas incluía la máxima cantidad de información morfológica posible sobre las especies. Las tres opciones proporcionaron diferentes resultados en relación a la distribución de las especies dentro del morfoespacio. Los resultados sugirieron que la incorporación de puntos que proporcionen información más específica sobre estructuras anatómicas que tienen papeles importantes en la biología de las especies, como aletas modificadas u órganos sensoriales, contribuye a una diferenciación más clara de las especies y a una mejor interpretación de la ocupación del morfoespacio. Adicionalmente, varios métodos numéricos y gráficos se emplearon con el fin de establecer cómo las especies se distribuyen dentro del morfoespacio. Los resultados demostraron que los métodos de agregación de puntos, incluyendo análisis basados en cuadrantes o distancias, fueron más apropiados para este propósito que los índices de disparidad morfológica. Además, los resultados también confirmaron que aunque los métodos numéricos fueron necesarios para evaluar la significancia estadística de los mismos, los métodos gráficos proporcionaron una interpretación más intuitiva y clara de la distribución de las especies dentro del morfoespacio. La densidad de Kernel y los gráficos de Gabriel se mostraron muy útiles a la hora de deducir la zona del morfoespacio donde las especies estaban más densamente agrupadas, hecho que ayudó a mejorar el conocimiento de la ocupación del espacio y de la complejidad estructural en comunidades de peces

Summer diet of European Shags Phalacrocorax aristotelis desmarestii in southern Mallorca

16 pages, 4 pages, 3 tablesAnalysis of pellets of European Shags Phalacrocorax aristotelis desmarestii collected at a non-breeding roost site in southern Mallorca identified 36 species of fish prey, belonging to 27 genera and to 16 families. This diversity is higher than in the diet of P. a. aristotelis in the Atlantic, and higher than in the previous literature for P. a. desmarestii in the Mediterranean. European Shags in southern Mallorca foraged mainly on fishes with a mean estimated length of 11.6 cm (84.1% ranging from 6.1–15.0 cm in estimated length), most being pelagic species (59.6 %). The most important fish in numerical frequency (43.9%) and estimated biomass (37.2%) was the Bogue Boops boops (Sparidae). This species has not been reported in European Shag diet in the Atlantic, and its importance was low in other Ph. a. desmarestii populations studied. The second most frequent prey was sand smelt Atherina (15%), but its contribution to biomass was low (1.4% of estimated biomass) because of its small size, as has been reported from other Mediterranean locations. The occurence of Scorpaenidae (10.7% by frequency, 17.4% of estimated biomass) was higher than in previous studies of Ph. a. desmarestii. Scorpaenids have not been found in the diet of Ph. a. aristotelis. Sandeels (Ammodytidae), a key prey for Ph. a. aristotelis in the Atlantic, were very scarce in this study, as in other recent Mediterranean studies. The relative abundance of species anatomically well protected against predation, such as scorpaenids and trachinids, and the diversity of prey probably reflects the scarcity or absence of other preferred prey. This study reflects the opportunistic behaviour of European Shags in the Mediterranean Sea, foraging on fish with very different ecological requirements, in an environment that is poor but diverseThis paper is included as a colateral research in the DGICYT Research Projects CGL2012–38089 and MINECO Research Project CTM2010–19701. Dr. Victor M. Tuset has a contract JAE-DOC (CSIC) co-funded by the European Social FoundationPeer reviewe

Advances in the systematics of the spider genus Troglohyphantes (Araneae, Linyphiidae)

With 128 described species and five subspecies, the spider genus Troglohyphantes (Araneae, Linyphiidae) is a remarkable example of species diversification in the subterranean environment. In this paper, we conducted a systematic revision of the Troglohyphantes species of the Italian Alps, with a special focus on the Lucifuga complex, including the description of two new species (T. lucifer sp. nov. and T. apenninicus n. sp.). In addition, we provided new diagnostic drawings of the holotype of T. henroti (Henroti complex) and established three new synonymies within the genus. The molecular analysis of the animal DNA barcode confirms the validity of this method of identification of the Alpine Troglohyphantes and provides additional support for the morphology based species complexes. Finally, we revised the known distribution range of additional Troglohyphantes species, as well as other poorly known alpine cave-dwelling spiders

A new minimal mathematical model of the endocrine system of normal rats validated against experimental data

As a common laboratory practice, rats are studied as biological models for understanding human physiology. Even though, with the advent of modern computer sciences, new methodologies appeared in medical sciences like simulation and optimization to simplify and improve the experimental work. With this background, a novel simulation model of the endocrine system of Sprague Dawley rats is presented. It is a simplified mathematical model composed of 3 differential equations and 8 parameters that have been determined and validated with experimental measures of plasma glucose and insulin alone by means of calculus and optimization techniques. The results presented here are a step before the development of a type I diabetic model of Sprague Dawley rats.Sociedad Argentina de Informática e Investigación Operativ

Influencia de la actividad física y práctica deportiva en el rendimiento académico del alumnado de educación secundaria

This research aims to identify whether the performance of sport and physical activity influences the academic achievement of adolescents in their school years. To do this, it has been taken through a quantitative approach to inferential character, a sample of 91 students of ESO students (n = 91). On the one hand, sport and physical activity was measured through global physical activity questionnaire GPAQ (OMS, 2004), on the other hand, have implemented a number of questions on academic performance, focusing on the overall rating the last quarter and the number of failed subjects in addition to their subjective assessment of sports. The results show that students exhibiting higher levels of physical activity have better academic performance than those not involved in the practice, both in its upper half note as the lower number of failed subjects. In turn, these results are more positive when many hours of sport are made, and students who perform also any kind of sports have a more positive assessment than physically inactive students.La presente investigación pretende identificar si la realización de práctica deportiva y de actividad física tiene influencia en el rendimiento académico de adolescentes en su etapa escolar. Se ha tomado a través de un enfoque cuantitativo con carácter inferencial, una muestra de 91 alumnos estudiantes de ESO (n=91). Los instrumentos utilizados han sido el cuestionario mundial de actividad física GPAQ (OMS, 2004), valoración subjetiva de la práctica deportiva y una serie de cuestiones sobre el rendimiento académico, centradas en la nota media del último trimestre y número de asignaturas suspendidas. Los resultados muestran que los alumnos que exponen mayores niveles de actividad física tienen un mejor rendimiento académico que los que no realizan dicha práctica. A su vez, estos resultados son más positivos cuantas más horas de práctica deportiva se realizan, y los alumnos que realizan cualquier tipo de práctica deportiva tienen una valoración más positiva que los alumnos inactivos

Altered expression of the immunoregulatory ligand-receptor pair CD200-CD200R1 in the brain of Parkinson's disease patients

Neuroinflammation, in which activated microglia are involved, appears to contribute to the development of Parkinson's disease (PD). However, the role of microglial activation and the mechanisms governing this process remain uncertain. We focused on one inhibitory mechanism involved in the control of microglial activation, the microglia inhibitory receptor CD200R1, and its ligand CD200, mainly expressed by neurons. The human CD200R1 gene encodes two membrane-associated and two soluble protein isoforms and the human CD200 gene encodes full-length proteins (CD200full) but also truncated (CD200tr) proteins which act as CD200R1 antagonists. Little is known about their expression in the human brain under pathological conditions. We used human peripheral blood monocytes and monocyte-derived microglia-like cells from control subjects to characterize the expression of the CD200R1 mRNA variants, which showed stimulus-specific responses. We provide evidence of increased CD200R1 (mRNA variants and protein isoforms) and CD200 expression (CD200tr mRNA) in brain tissue of PD patients, mainly in the hippocampus, as well as increased CD200 expression (CD200full and CD200tr mRNAs) in iPSCs-derived dopaminergic neurons generated from skin fibroblasts of PD patients. Our results suggest that CD200-CD200R1 signalling is altered in PD, which may affect the microglial function and constitute a potential target in therapeutic strategies for PD.© 2022. The Author(s)