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

Density Local Discriminant Bases for the analysis of otolith morphology in fish identification applications

Postprint (published version

Prevalencia y prevención de las úlceras por presión en una cohorte de nonagenarios. Estudio NonaSantfeliu

IntroducciónEl envejecimiento progresivo de la población ha comportado un rápido aumento del grupo poblacional de los habitantes más ancianos, de manera que los > 89 años representan aproximadamente el 2% del total de > 65 años en España1. Las úlceras por presión (UPP) son un importante problema de salud por su prevalencia y morbilidad asociada2, que pueden afectar a pacientes en todos los ámbitos asistenciales. Una gran mayoría de ellas (alrededor del 70%)3 ocurren en personas > 70 años. Diversos estudios han mostrado que con una correcta implementación de políticas específicas destinadas a su prevención se consigue evitar su aparición en un considerable número de casos2,4.ObjetivosEvaluar en nuestro medio la prevalencia e incidencia de UPP en un grupo de población muy frágil, como son los nonagenarios, y comprobar la efectividad de un programa de prevención basado en recomendaciones para prevenir su aparición y enseñanza de los cuidados, cuando haya, para conseguir su curación.DiseñoEstudio de cohortes prospectivo.EmplazamientoCentros de atención primaria.ParticipantesEl trabajo se realizó dentro del estudio NonaSantfeliu, descrito ya previamente5. Se incluyó en el estudio inicial a 186 nonagenarios, el período de observación fue de 12 meses y se realizaron 2 evaluaciones al inicio y al final del período por parte del personal médico y/o de enfermería entrenado en la valoración geriátrica. Al año se revaluó a 140 nonagenarios; se excluyó a 36 participantes por haber fallecido y a 10 por cambio de domicilio.Mediciones principalesMediante entrevista personal, exploración a domicilio o en el centro de atención primaria cuando fue posible y posterior revisión de historia clínica, se recogieron datos sociodemográficos, actividades básicas de la vida diaria con el índice de Barthel (IB), cognición con el Miniexamen cognitivo de Lobo (MEC), comorbilidad con el índice de Charlson, riesgo de UPP con la escala de Braden con una puntuación 0-23 (< 12, alto riesgo), y valores de la version abreviada del Mini-Nutritional Assesment (MNA-SF) del año previo. El MNA-SF que puntúa de 0-14 (< 11 se considera riesgo nutricional) puede, al detectar pacientes de riesgo nutricional, ser útil para identificar a los pacientes con mayor incidencia de nuevas UPP.IntervencionesEducación sanitaria a los pacientes y cuidadores, para una correcta aplicación de medidas preventivas, y enseñanza de los cuidados necesarios para la cura de las UPP según la guía de UPP del Institut Català de Salut.ResultadosSe evaluó a 109 mujeres (77,8%) y 31 varones, con un promedio de edad al inicio del estudio de 92,7±2,8 años. En total, 114 eran viudos (81,5%), 14 (10%) estaban casados, y 12 (8,5%) eran solteros. La mayoría, 102 (73%), seguía viviendo en la comunidad y 38 estaban institucionalizados. Al final del período la media del IB era de 56,9±30,3, del MEC 22,4±11, del índice de Charlson de 1,1±1,5 y del MNA-SF de 11,4±2,1. Los valores medios de la escala de Braden eran de 15,5±2,4. El año previo, la prevalencia de UPP era del 7,1% (10) y al final del período de seguimiento, se habían curado todos los casos a excepción de un paciente. La incidencia de nuevas UPP fue del 3,5% (5 casos) con una prevalencia al año del 4,2% (3 mujeres y 3 varones). En la tabla 1 se puede observar las principales diferencias entre los pacientes con UPP al año de seguimiento y los pacientes sin UPP. En el análisis de regresión múltiple, tras ajustar por la edad y el sexo, la escala de Braden fue la única variable asociada significativamente con tener UPP en el momento de la evaluación (p=0,011; odds ratio [OR]=3,2; intervalo de confianza [IC] del 95%, 1,3-7,8).DiscusiónLas UPP han pasado de ser consideradas durante años un problema banal e inevitable a constituir en la actualidad un indicador de calidad asistencial debido a su gran impacto económico, tanto en el consumo de recursos humanos como materiales. La identificación de pacientes de riesgo y las recomendaciones preventivas son, sin duda, la mejor actuación para combatir las UPP2. El importante descenso observado en nuestro estudio, cercano al 50%, tras la implementación de medidas preventivas confirma la utilidad de la prevención, incluso en el paciente más anciano. Dado el reducido tamaño de la muestra, no se han observado diferencias en la prevalencia según el sexo, aunque se ha descrito una mayor prevalencia en mujeres6.ConclusionesLos programas de prevención de UPP son útiles en pacientes nonagenarios y debería intensificarse su implantación en los pacientes con riesgo en las escalas específicas para UPP, como la de Braden o con riesgo nutricional (MNASF)

In vitro biocompatibility and electrical stability of thick-film platinum/gold alloy electrodes printed on alumina

OBJECTIVE: High-density electrode arrays are a powerful tool in both clinical neuroscience and basic research. However, current manufacturing techniques require the use of specialised techniques and equipment, which are available to few labs. We have developed a high-density electrode array with customisable design, manufactured using simple printing techniques and with commercially available materials. APPROACH: Electrode arrays were manufactured by thick-film printing a platinum-gold alloy (Pt/Au) and an insulating dielectric on 96% alumina ceramic plates. Arrays were conditioned in serum and serum-free conditions, with and without 1kHz, 200µA, charge balanced stimulation for up to 21 days. Array biocompatibility was assessed using an extract assay and a PC-12 cell contact assay. Electrode impedance, charge storage capacity and charge injection capacity were before and after array conditioning. MAIN RESULTS: The manufactured Pt/Au electrodes have a highly porous surface and exhibit electrical properties comparable to arrays manufactured using alternative techniques. Materials used in array manufacture were found to be non-toxic to L929 fibroblasts by extract assay, and neuronal-like PC-12 cells adhered and extended neurites on the array surfaces. Arrays remained functional after long-term delivery of electrical pulses while exposed to protein-rich environments. Charge storage capacities and charge injection capacities increased following stimulation accounted for by an increase in surface index (real surface area) observed by vertical scanning interferometry. Further, we observed accumulation of proteins at the electrode sites following conditioning in the presence of serum. SIGNIFICANCE: This study demonstrates the in vitro biocompatibility of commercially available thick-film printing materials. The printing technique is both simple and versatile, with layouts readily modified to produce customized electrode arrays. Thick-film electrode arrays are an attractive tool that may be implemented for general tissue engineering and neuroscience research

Back to the future: restoring historical communities

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The macrofauna associated to the bamboo coral Isidella elongata: to what extent the impact on isideidae affects diversification of deep-sea fauna

Macrofauna associated with the bamboo coral Isidella elongata was analysed in the Balearic Basin at depths of 697–1308 m. The diversity of associated macrofauna and the specific associations identified depended on different morphological characteristics of colonies, such as height or density of rami. Species associated with Isidella consisted mainly of sessile fauna, such as cnidarians (the actinian Amphianthus dornhii and the solitary coral Desmophyllum dianthus) and cirripeds (Gibossaverruca sp.). The strongest relationship (commensalism) occurred for the Pontogeneiidae amphipod Dautzenbergia megacheir, living attached to colonies of Isidella and represented by all population stages from adult (oostegal) females and males to juveniles. Species-coral relationships between Dautzenbergia and bamboo corals (Isididae) are plausible. Dautzenbergia spp. showed morphological differences between Atlantic (described by Walker 1897 as “eyes wanting”) and Mediterranean (with well-developed reddish eyes) specimens. This would suggest diversification of this genus, as has been recently suggested for Pleustidae associated with deep gorgonians. The diversity of the macrofaunal community associated with I. elongata was higher in the most mature (larger colonies with higher density) fields found NW of Mallorca, with higher colonies than in other parts of the Mediterranean. This was the only site where Gibossaverruca sp. (a first Mediterranean faunal record) and D. dianthus were collected. These complex associations between macrofauna and deep-water corals may provide arguments to protect these fragile ecosystems as a source of faunal diversity and diversification.Versión del editor3,87

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

How the reconstruction of faunal communities in a marine protected area (Columbretes Reserve, western Mediterranean) evidence human and natural impacts on fauna

Reconstruction of marine communities in search of baseline (pristine) conditions is a crucial first step for their future restoration. A recent reconstruction (last century) of the sandy-muddy bottom fauna on the continental shelf of a marine protected area (MPA) was performed in the Columbretes Reserve, including periods after and before the Reserve declaration. The dating of sediments and identification of faunal remains (e.g., shells of benthic bivalves and gastropods and pelagic pteropods) were performed in a core (MC2) at a depth of 87 m in 2018. Radiometric data identified sediments older (below 11 cm) and younger (from the top of the core to 11 cm) than ca. 110 years. Mercury analyses validated the 210Pbxs data at 5–7 cm (1967–1989), with a significant Hg peak that coincided with a period of military activities occurring until 1982 in the Columbretes Islands. Both human and climatic variables affected benthic and pelagic communities. Among the human impacts, the cessation of trawling activity after the declaration of the MPA (1980s) influenced the most dominant benthos (bivalves and gastropods) by i) increases in their abundance and ii) changes in the feeding guilds, with a return to baseline conditions by the increase in filter feeders after trawling cessation vs a high abundance of detritus feeders occurring under high trawling activity. Human activities apparently did not affect diversity levels. In parallel, we also identified some recolonization by Octocorallia since the 1980s. Finally, the increase in the pelagic pteropod Creseis acicula since 1995 at the MC2 station probably indicates the result of warming of surface waters in recent decades. Our study based on core reconstructions provides for the first time an historical perspective of the impact of trawling on marine benthos and the positive effect of conservation measures in marine protected areas.En prens