Somatic evolution of marine transmissible leukemias in the common cockle, Cerastoderma edule.

Transmissible cancers are malignant cell lineages that spread clonally between individuals. Several such cancers, termed bivalve transmissible neoplasia (BTN), induce leukemia-like disease in marine bivalves. This is the case of BTN lineages affecting the common cockle, Cerastoderma edule, which inhabits the Atlantic coasts of Europe and northwest Africa. To investigate the evolution of cockle BTN, we collected 6,854 cockles, diagnosed 390 BTN tumors, generated a reference genome and assessed genomic variation across 61 tumors. Our analyses confirmed the existence of two BTN lineages with hemocytic origins. Mitochondrial variation revealed mitochondrial capture and host co-infection events. Mutational analyses identified lineage-specific signatures, one of which likely reflects DNA alkylation. Cytogenetic and copy number analyses uncovered pervasive genomic instability, with whole-genome duplication, oncogene amplification and alkylation-repair suppression as likely drivers. Satellite DNA distributions suggested ancient clonal origins. Our study illuminates long-term cancer evolution under the sea and reveals tolerance of extreme instability in neoplastic genomes.

How Important Are Functional and Developmental Constraints on Phenotypic Evolution? An Empirical Test with the Stomatal Anatomy of Flowering Plants.

AbstractQuantifying the relative contribution of functional and developmental constraints on phenotypic variation is a long-standing goal of macroevolution, but it is often difficult to distinguish different types of constraints. Alternatively, selection can limit phenotypic (co)variation if some trait combinations are generally maladaptive. The anatomy of leaves with stomata on both surfaces (amphistomatous) present a unique opportunity to test the importance of functional and developmental constraints on phenotypic evolution. The key insight is that stomata on each leaf surface encounter the same functional and developmental constraints but potentially different selective pressures because of leaf asymmetry in light capture, gas exchange, and other features. Independent evolution of stomatal traits on each surface imply that functional and developmental constraints alone likely do not explain trait covariance. Packing limits on how many stomata can fit into a finite epidermis and cell size-mediated developmental integration are hypothesized to constrain variation in stomatal anatomy. The simple geometry of the planar leaf surface and knowledge of stomatal development make it possible to derive equations for phenotypic (co)variance caused by these constraints and compare them with data. We analyzed evolutionary covariance between stomatal density and length in amphistomatous leaves from 236 phylogenetically independent contrasts using a robust Bayesian model. Stomatal anatomy on each surface diverges partially independently, meaning that packing limits and developmental integration are not sufficient to explain phenotypic (co)variation. Hence, (co)variation in ecologically important traits like stomata arises in part because there is a limited range of evolutionary optima. We show how it is possible to evaluate the contribution of different constraints by deriving expected patterns of (co)variance and testing them using similar but separate tissues, organs, or sexes.

Effects of Copenhagen Adduction Exercise on Muscle Architecture and Adductor Flexibility.

Groin injuries are one of the most prevalent in sports, especially due to the hip adductor muscles' weakness, which is considered as a risk factor. The Copenhagen adduction exercise (CAE) has been demonstrated to increase the strength of adductor muscles, but its effects on the architectural characteristics and flexibility of the adductors has been little studied. The aim of the present study was to analyse the impact on the muscular architecture and flexibility of the adductor musculature after 8 weeks of CAE-based training and after 4 weeks of subsequent detraining. A sample of 45 active subjects (26.1 ± 2.8 years old) were randomly divided into a control group with no intervention and an experimental group with an intervention based on 8 weeks of CAE training and 4 weeks of subsequent detraining. The muscle thickness of adductors was measured before and after training and detraining using ultrasound imaging and hip abduction range with goniometry. A significant increase in muscle thickness (left leg: +17.83%, d = 1.77, p < 0.001//right leg: +18.38%, d = 1.82, p < 0.001) and adductor flexibility was found in the experimental group (left leg: +7.3%, d = 0.96, p < 0.05//right leg: +7.15%, d = 0.94, p < 0.05), and after detraining, both variables returned to their initial values. These results could indicate that CAE would be a suitable strategy to modify the architecture of the adductors and thus form part of training protocols designed for the prevention and rehabilitation of muscle injuries.

Impact of High-Intensity Interval Training on Body Composition and Depressive Symptoms in Adults under Home Confinement.

The home confinement derived from the COVID-19 pandemic has led to drastic changes in people's habits. This situation has influenced their eating, rest, physical activity and socialization patterns, triggering changes in their mental stability. It was demonstrated that physical activity is beneficial for people's physical and mental health. By its moderate volume and requiring little space or material, high-intensity interval training (HIIT) could prove to be a valid alternative in a situation of confinement. The aim of the present study was to observe the impact of an 8-week HIIT protocol on the body composition and the depressive symptoms of adults in strict home confinement. A total of 21 healthy adults, both male and female, (35.4 ± 5.6 years old; 70.50 ± 12.1 kg; 171 ± 10 cm) were divided into an experimental group (EG, n = 11) who carried out an 8-week Tabata protocol, based upon calisthenic exercises with their own weight in their homes, and a control group (CG, n = 10) who did not carry out any systematic physical activity over the same period. Following the intervention, the EG experienced a significant reduction in percentage (t = 3.86, d = 0.57, p < 0.05) and in kg (t = 4.62, d = 0.29, p < 0.05) of body fat mass (BFM) and body fat mass index (BFMI) (t = 4.61, d = 0.31, p < 0.05), as well as a reduction in depressive symptoms (t = 6.48, d = 1.3, p < 0.05). These results indicate that HIIT is a potential public health tool that could possibly be prescribed to the population in case of future situations of home confinement.

Mitochondrial genome sequencing of marine leukaemias reveals cancer contagion between clam species in the Seas of Southern Europe.

Clonally transmissible cancers are tumour lineages that are transmitted between individuals via the transfer of living cancer cells. In marine bivalves, leukaemia-like transmissible cancers, called hemic neoplasia (HN), have demonstrated the ability to infect individuals from different species. We performed whole-genome sequencing in eight warty venus clams that were diagnosed with HN, from two sampling points located more than 1000 nautical miles away in the Atlantic Ocean and the Mediterranean Sea Coasts of Spain. Mitochondrial genome sequencing analysis from neoplastic animals revealed the coexistence of haplotypes from two different clam species. Phylogenies estimated from mitochondrial and nuclear markers confirmed this leukaemia originated in striped venus clams and later transmitted to clams of the species warty venus, in which it survives as a contagious cancer. The analysis of mitochondrial and nuclear gene sequences supports all studied tumours belong to a single neoplastic lineage that spreads in the Seas of Southern Europe.

In humans and other animals, cancer cells divide excessively, forming tumours or flooding the blood, but they rarely spread to other individuals. However, some animals, including dogs, Tasmanian devils and bivalve molluscs like clams, cockles and mussels, can develop cancers that are transmitted from one individual to another. Despite these cancers being contagious, each one originates in a single animal, meaning that even when the cancer has spread to many individuals, its origins can be traced through its DNA. Cancer contagion is rare, but transmissible cancers seem to be particularly common in the oceans. In fact, 7 types of contagious cancer have been described in bivalve species so far. These cancers are known as 'hemic neoplasias', and are characterized by the uncontrolled division of blood-like cells, which can be released by the host they developed in, and survive in ocean water. When these cells encounter individuals from the same species, they can infect them, causing them to develop hemic neoplasia too There are still many unanswered questions about contagious cancers in bivalves. For example, how many species do the cancers affect, and which species do the cancers originate in? To address these questions, Garcia-Souto, Bruzos, Díaz et al. gathered over 400 specimens of a species of clam called the warty venus clam from the coastlines of Europe and examined them for signs of cancer. Clams collected in two regions of Spain showed signs of hemic neoplasia: one of the populations was from the Balearic Islands in the Mediterranean Sea, while the other came from the Atlantic coast of northwestern Spain. Analyzing the genomes of the tumours from each population showed that the cancer cells from both regions had likely originated in the same animal, indicating that the cancer is contagious and had spread through different populations. The analysis also revealed that the cancer did not originally develop in warty venus clams: the cancer cells contained DNA from both warty venus clams and another species called striped venus clams. These two species live close together in the Mediterranean Sea, suggesting that the cancer started in a striped venus clam and then spread to a warty venus clam. To determine whether the cancer still affected both species, Garcia-Souto, Bruzos, Díaz et al. screened 200 striped venus clams from the same areas, but no signs of cancer were found in these clams. This suggests that currently the cancer only affects the warty venus clam. These findings confirm that contagious cancers can jump between clam species, which could be threat to the marine environment. The fact that the cancer was so similar in clams from the Atlantic coast and from the Mediterranean Sea, however, suggests that it may have emerged very recently, or that human activity helped it to spread from one place to another. If the latter is the case, it may be possible to prevent further spread of these sea-borne cancers through human intervention.

Impact of Askling L-PROTOCOL on Biceps Femoris Architecture, Hamstring Flexibility and Sprint Performance.

Eccentric training has been shown to be important for hamstring strain injuries rehabilitation and prevention. The Askling L-PROTOCOL (L-P), comprising three exercises aimed at eccentric training and hamstring lengthening, was shown to improve this injuries recovery and relapse times in comparison with other traditional exercise-based protocols. However, the causes of these results remain unclear. This study looks at the impact of an 8-week L-P followed by 4 weeks of detraining on the architecture of the biceps femoris long head, hamstring flexibility and sprint performance. Twenty-eight healthy individuals were divided into two groups: an experimental group, which carried out the L-P, and a control group with no training. Muscle architecture was measured using 2D ultrasound, hamstring flexibility using goniometry and sprint performance using sports radar equipment before (M1) and after (M2) the training period and after detraining (M3). No significant changes were observed between M1 and M2 in the experimental group with regard to fascicle length (t=- 0.79, P>0.05), theoretical maximum speed (t=- 1.43, P>0.05), horizontal force (t=0.09, P>0.05), force application during sprint running (t=- 0.09, P>0.05) and horizontal power (t=- 0.97, P>0.05), but, however, changes were observed in hamstring flexibility (t=- 4.42, d=0.98, P<0.001) returning to pre-training values after detraining period (t=- 1.11, P>0.05). L-P has been shown to be an eccentric protocol of moderate intensity and easy implementation that could be interesting to include throughout a sports season.

Reproductive cycle of the sea cucumber Holothuria forskali (Holothuriida: Holothuriidae) in the Ría de Vigo (NW of Spain) / Ciclo reproductivo del pepino de mar Holothuria forskali (Holothuriida: Holothuriidae) en la Ría de Vigo (NW de España)

Introduction: The exploitation of the sea cucumber (Holothuria (Panningothuria) forskali) in Ría de Vigo (NW Spain) is recent (2015) and it has been done until now with scarce or no information about some key biological aspects as reproduction, recruitment or growth. Objective: To describe the reproductive cycle of H. forskali in Ría de Vigo. Methods: We sampled fortnightly throughout 2018. We calculated gonadal condition indices (GCI) and gametogenic stages by classic histological methods. Results: The reproductive cycle of H. forskali in the Ría de Vigo is characterized by a sexual resting stage during spring, when temperature and daylight hours are lower; the beginning of gametogenesis during summer, when temperature is higher, daylight hours longer and the sea bottom is rich in nutrients; then, a period of spawns interspersed with a gonadal restoration during autumn and winter, when temperature is lower and food is scarce. Sex ratio is 1:1, however, the studied population is not synchronized, because females initiate maturation earlier. The comparison of the histological results with GCI indices suggest that GCI is a good indicator for gonadal stage. Fishery management strategies, such as a closure period, must be adapted to the reproductive stage. We recommend avoiding fishing between November and February to increase spawning potential ratio and, consequently, recruitment.

Introducción: La explotación del pepino de mar (Holothuria (Panningothuria) forskali) en la Ría de Vigo (NO España) es reciente (2015) y se ha llevado a cabo con poca o ninguna información sobre algunos aspectos biológicos claves como la reproducción, el reclutamiento o el crecimiento. Objetivo: Describir el ciclo reproductivo de H. forskali en un banco de la Ría de Vigo. Métodos: Se tomaron muestras quincenales durante el 2018. Se calcularon índices de condición gonadal (ICG) y se obtuvieron los estados gonadales siguiendo métodos histológicos clásicos. El estado gonadal de cada individuo se asignó de acuerdo con una escala modificada por otros autores, y en ella se describe un nuevo estado de recuperación gonadal, no descrito hasta ahora para esta especie. Resultados: El ciclo reproductivo de H. forskali se caracteriza por una etapa de reposo sexual en primavera, un inicio de la gametogénesis durante el verano y un período de puestas sucesivas intercaladas con recuperaciones gonadales durante el otoño e invierno. La proporción de sexos es 1:1 y la población estudiada no está sincronizada, las hembras inician la maduración antes. La comparación de los resultados histológicos con los índices ICG sugiere que este índice es un buen indicador del estado gonadal. El período de veda debe adaptarse a la etapa reproductiva, por lo que recomendamos evitar la extracción del recurso al menos entre noviembre y febrero para asegurar un mayor número de puestas y, en consecuencia, el reclutamiento.

Intervención educativa, intersectorial e interdisciplinaria para la promoción de alimentación saludable en el ámbito escolar / Educational and interdisciplinary intervention for promotion of healthy nutrition habits in the school enviroment

Introducción: el ámbito escolar es propicio para desplegar los mensajes de salud, dentro del cual la tarea del pediatra y el nutricionista se extiende en el trabajo interdisciplinar y se enriquece con el aporte del sector docente. La elección de los alumnos como multiplicadores resulta en un impacto hacia toda la comunidad escolar que abarca el entorno familiar. Objetivos: se describe una intervención educativa desarrollada en el ambiente escolar dirigida a alumnos de 7... grado de una escuela pública de la Ciudad Autónoma de Buenos Aires, con el propósito de formarlos como agentes multiplicadores de hábitos y estilos de vida saludables. Materiales y métodos: se expone un modelo socio-ecológico de medicina y se discuten qué tipos de resultados deben eva- luarse. Se detalla el trabajo en sus tres etapas: inicial (planifi- cación interdisciplinaria y vinculación con los docentes), central (desarrollo de los talleres) y final (evaluación de resultados). Resultados: se destaca como principal resultado del impacto de la intervención el conjunto de productos finales determinados por las actividades que los multiplicadores realizan para comu- nicar los mensajes de salud a la comunidad escolar. Se dan por cumplidos los resultados de meta como cronograma y cobertura. Conclusiones: se concluye que la escuela es un ámbito propicio para el despliegue de la educación alimentaria y que la formación de los niños como agentes multiplicadores tiene un efecto am- plificador hacia toda la comunidad. En este sentido, este artículo detalla la aplicación concreta de acciones intersectoriales y mul- tidisciplinarias dentro del marco escolar y la salud comunitaria

Self-Organizing Neural Networks Based on OxRAM Devices under a Fully Unsupervised Training Scheme.

A fully-unsupervised learning algorithm for reaching self-organization in neuromorphic architectures is provided in this work. We experimentally demonstrate spike-timing dependent plasticity (STDP) in Oxide-based Resistive Random Access Memory (OxRAM) devices, and propose a set of waveforms in order to induce symmetric conductivity changes. An empirical model is used to describe the observed plasticity. A neuromorphic system based on the tested devices is simulated, where the developed learning algorithm is tested, involving STDP as the local learning rule. The design of the system and learning scheme permits to concatenate multiple neuromorphic layers, where autonomous hierarchical computing can be performed.

Low-Power, High-Performance, Non-volatile Inkjet-Printed HfO2-Based Resistive Random Access Memory: From Device to Nanoscale Characterization.

Low-power, high-performance metal-insulator-metal (MIM) non-volatile resistive memories based on HfO2 high- k dielectric are fabricated using a drop-on-demand inkjet printing technique as a low-cost and eco-friendly method. The characteristics of resistive switching of Pt (bottom)/HfO2/Ag (top) stacks on Si/SiO2 substrates are investigated in order to study the bottom electrode's interaction with the HfO2 dielectric layer and the resulting effects on resistive switching. The devices show low Set and Reset voltages, high ON/OFF current ratio, and relatively low switching current (∼1 µA), which are comparable to the characteristics of current commercial CMOS memories. In order to understand the resistive switching mechanism, direct structural observation is carried out by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM) on cross-sectioned samples prepared by focused ion beam (FIB). In addition, electron energy loss spectroscopy (EELS) inspections discard a silver electro-migration effect.

Changes in rectus femoris architecture induced by the reverse nordic hamstring exercises.

BACKGROUND: Injuries and mechanical stimuli alter the muscle architecture and, therefore, its function. The changes in the architecture of the rectus femoris (RF) induced by an eccentric training protocol with reverse nordic hamstring exercises (RNHE) have never been studied. Therefore, the aim of the present study was to determine the architectural adaptations of the RF after an eccentric training with RNHE, followed by a subsequent detraining period. METHODS: Twenty-six subjects performed a first week of control, 8 weeks of eccentric training, concluding with a 4-week period of detraining. The architectural characteristics of the RF were evaluated using 2D ultrasound at rest (pretest: week 1), after the training (post-test: week 9), and at the end of the detraining period (retest: week 13). RESULTS: At the end of the training period, a significant increase in the muscle fascicle length (FL) (t=-8.96, d=2.22, P<0.001), muscle thickness (MT) (t=-8.76, d=2.219, P<0.001), pennation angle (PA) (t=-9.83, d=2.49, P<0.05) and cross-sectional area (CSA) (t=-13.06, d=3.06, P<0.001) was observed. After the detraining period FL, MT, PA and CSA showed a significant decrease. CONCLUSIONS: The eccentric training with RNHE may cause changes in the architectural conditions of RF, which, in addition, are also reversible after a 4-week detraining period. The adaptations produced by RNHE may have practical implications for injury prevention and rehabilitation programs, which include the changes in muscle architecture variables.

Numerical Study of Hydrodynamic Forces for AFM Operations in Liquid.

For advanced atomic force microscopy (AFM) investigation of chemical surface modifications or very soft organic sample surfaces, the AFM probe tip needs to be operated in a liquid environment because any attractive or repulsive forces influenced by the measurement environment could obscure molecular forces. Due to fluid properties, the mechanical behavior of the AFM cantilever is influenced by the hydrodynamic drag force due to viscous friction with the liquid. This study provides a numerical model based on computational fluid dynamics (CFD) and investigates the hydrodynamic drag forces for different cantilever geometries and varying fluid conditions for Peakforce Tapping (PFT) in liquids. The developed model was verified by comparing the predicted values with published results of other researchers and the findings confirmed that drag force dependence on tip speed is essentially linear in nature. We observed that triangular cantilever geometry provides significant lower drag forces than rectangular geometry and that short cantilever offers reduced flow resistance. The influence of different liquids such as ultrapure water or an ethanol-water mixture as well as a temperature induced variation of the drag force could be demonstrated. The acting forces are lowest in ultrapure water, whereas with increasing ethanol concentrations the drag forces increase.

A synthesis of radial growth patterns preceding tree mortality.

Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1-100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks.

Factores asociados a la comprensión lectora en estudiantes de noveno grado de Barranquilla / Factors associated with reading comprehension in students of ninth grade in Barranquilla

Resumen El presente artículo es resultado de una investigación cuyo objetivo consistió en determinar la incidencia de los factores asociados al desarrollo de la comprensión lectora en estudiantes de noveno grado de la Institución Educativa Distrital Jesús Maestro Fe y Alegría de Barranquilla. Asumiendo que la comprensión lectora está presente en la vida como fuente de entendimiento y placer, esta investigación surge porque los docentes en aula han identificado que los estudiantes presentan dificultades en el proceso lector que pueden estar asociadas a factores académicos, socioculturales y personales. El diseño es de carácter mixto (cualitativo-cuantitativo) y las técnicas de recolección de información fueron: entrevista y encuestas con preguntas cerradas y abiertas. Los resultados evidenciaron que el 50 % de los estudiantes poseen la habilidad para comprender lo que leen, pero su contexto familiar no acompaña los procesos y en lo escolar no hay ambientes que motiven la lectura. Lo anterior se evidencia en su desempeño escolar. Ante este problema, la institución debe gestionar estrategias pedagógicas para fomentar procesos lectores en los que se integren las áreas del conocimiento, así como crear espacios para el desarrollo de la lectura y su comprensión.

Abstract This article is the result of research and its main work objective is to determine the incidence of the factors associated with the development of reading comprehension for ninth grade students of School District Jesús Maestro Fe y Alegría of Barranquilla. Based on the fact that reading comprehension is present in life as a source of understanding and pleasure, because when learners read, they are generally motivated to think and respond with answers; this research arises because teachers in the classroom identify those students that have difficulties in the reading process, which in turn may be associated with academic, cultural and personal factors that significantly affect the teaching-learning process.The design is of a mixed nature (qualitative - quantitative) and the techniques of data collection were made through interviews and surveys with closed and open questions. The results proved that 50 % of students have the ability to understand what they read, but from the familiar context does not accompany the process and from the school point of view no favorable environments encourage reading. This of course is evident in school performance thereof. Faced with this situation the institution must manage educational strategies to promote reading processes in the areas of knowledge, thus creating enough spaces for the development of integrated reading and understanding.

A novel paramyxean parasite, Marteilia octospora n. sp. (Cercozoa) infecting the Grooved Razor Shell clam Solen marginatus from Galicia (NW Spain).

Protozoan parasites of the genus Marteilia have been detected in marine bivalves and other invertebrates around the world, associated in some cases with mass mortalities. The present paper reports the characterization of the Marteilia sp. protozoan infecting the digestive gland of the Grooved Razor Shell clam (Solen marginatus) from Galicia (NW Spain), proposing a novel species in the genus: Marteilia octospora n. sp. Morphological and molecular techniques were used for the description of this parasite. Tissue imprints were essential in the study to confirm the presence of 8 spores per sporangium, a number never reported in other species from this genus. An ultrastructural study revealed that the size and number of dense granules, free in the mature sporangia, were quite different from granules in other Marteilia spp. Another morphological difference is the absence of a layer of concentric membranes found surrounding the mature spore in other species. In addition, concentric membranous structures observed in the different stages of the parasite have never been mentioned in other species of genus Marteilia. Moreover, molecular analysis of the rDNA intergenic spacer (IGS) and the internal transcribed spacer (ITS-1) showed differences with the sequences available for other Marteilia spp.

Histological survey of symbionts and other conditions of pod razor clam Ensis siliqua (Linnaeus, 1758) in Galicia (NW Spain).

The aim of the present study was to carry out a survey of parasites and other conditions affecting pod razor clam populations, Ensis siliqua, in two beds from Galicia (NW Spain). In Galicia, the production of E. siliqua has increased in recent years due to the development of specific plans for its exploitation, however few and quite recent pathological studies have been carried out in this species. The results of this study showed the presence of different protozoa as the more prevalent group, especially Nematopsis sp. gregarines, unidentified branchial protozoa, renal coccidia and Trichodina sp. ciliates. Larval stages of trematodes and neoplastic disorders were also observed with lower prevalences. Furthermore, an ultrastructural analysis of two types of unidentified basophilic inclusions, both found in the digestive gland, revealed the presence of icosahedral viral particles and prokaryotic organisms, respectively. None of the parasites detected in E. siliqua from this study was notifiable to the World Organisation for Animal Health (OIE) and the majority of the symbionts and conditions observed in their tissues did not cause host damage. Nevertheless, parasites like bucephalid digenean sporocysts, viral inclusions, prokaryotic infections, disseminated neoplasm or germinoma detected in some samples could cause moderate or severe damage to the host depending on the intensity of infection.

Histological survey of symbionts and other conditions in razor clam Ensis arcuatus (Jeffreys, 1865) (Pharidae) of the coast of Galicia (NW Spain).

Symbionts and abnormal conditions of razor clam Ensis arcuatus were surveyed in three commercially important natural beds of Galician estuaries (NW Spain). Samples of 15-20 E. arcuatus were collected every 2 months from January 2003 until July 2004 and processed for histological examination. Prokaryote-like colonies, renal coccidians, gregarines, Trichodina sp. ciliates, haplosporidian-like plasmodia, turbelaria, trematode metacercariae, cestode-like larvae and basophilic inclusion bodies were observed in razor clam tissues without causing host damage. Bucephalid digenean sporocysts and germinoma were seen in some samples causing moderate or severe damage to the host depending on the intensity of infection and both could be a cause for concern if prevalence reached epizootic levels in Galician E. arcuatus populations. None of the parasites detected is OIE notifiable and, in general, the commercially exploited beds studied seem to be devoid of serious pathogens.

La práctica de la Ligadura tubaria en hospitales públicos del Gran Mendoza: un cruce entre los derechos ciudadanos de las mujeres y los servicios de salud, un análisis desde la perspectiva de género (2000 - 2005)

Objetivos: Analizar la cuestión de la LT como derecho ciudadano de las mujeres. Describir las posiciones de los profesionales de la salud (con relación a: sus disciplinas, jerarquías, funciones y relaciones que guardan entre sí, y a sus posiciones éticas). Describir y analizar cómo se juegan las relaciones entre los profesionales de la salud y las mujeres (beneficiarias-usuarias) en torno de la decisión de LT.