Substrate Matters: Ionic Silver Alters Lettuce Growth, Nutrient Uptake, and Root Microbiome in a Hydroponics System.

Ionic silver (Ag+) is being investigated as a residual biocide for use in NASA spacecraft potable water systems on future crewed missions. This water will be used to irrigate future spaceflight crop production systems. We have evaluated the impact of three concentrations (31 ppb, 125 ppb, and 500 ppb) of ionic silver biocide solutions on lettuce in an arcillite (calcinated clay particle substrate) and hydroponic (substrate-less) growth setup after 28 days. Lettuce plant growth was reduced in the hydroponic samples treated with 31 ppb silver and severely stunted for samples treated at 125 ppb and 500 ppb silver. No growth defects were observed in arcillite-grown lettuce. Silver was detectable in the hydroponic-grown lettuce leaves at each concentration but was not detected in the arcillite-grown lettuce leaves. Specifically, when 125 ppb silver water was applied to a hydroponics tray, Ag+ was detected at an average amount of 7 µg/g (dry weight) in lettuce leaves. The increase in Ag+ corresponded with a decrease in several essential elements in the lettuce tissue (Ca, K, P, S). In the arcillite growth setup, silver did not impact the plant root zone microbiome in terms of alpha diversity and relative abundance between treatments and control. However, with increasing silver concentration, the alpha diversity increased in lettuce root samples and in the water from the hydroponics tray samples. The genera in the hydroponic root and water samples were similar across the silver concentrations but displayed different relative abundances. This suggests that ionic silver was acting as a selective pressure for the microbes that colonize the hydroponic water. The surviving microbes likely utilized exudates from the stunted plant roots as a carbon source. Analysis of the root-associated microbiomes in response to silver showed enrichment of metagenomic pathways associated with alternate carbon source utilization, fatty-acid synthesis, and the ppGpp (guanosine 3'-diphosphate 5'-diphosphate) stringent response global regulatory system that operates under conditions of environmental stress. Nutrient solutions containing Ag+ in concentrations greater than 31 ppb in hydroponic systems lacking cation-exchange capacity can severely impact crop production due to stunting of plant growth.

Not all respiratory infections were SARS-CoV-2 during the pandemic, analysis in a clinic on the Colombian Caribbean coast.

INTRODUCTION: Acute Respiratory Infections (ARIs) are considered one of the leading causes of morbidity and mortality worldwide. Children under five and older adults are most likely to die from this cause. OBJECTIVE: To describe the behavior of infection by respiratory viruses other than SARS-CoV-2 during the pandemic in a clinic in the Colombian Caribbean. METHODS: This descriptive and retrospective study evaluates the characteristics, associated comorbidities, and requirements of hospitalization or Intensive Care Unit in patients diagnosed with respiratory viral infections treated at IMAT Oncomedica clinic from July 2020 to August 2022. RESULTS: This study evaluated 351 patients with respiratory symptoms, observing an exponential increase in cases of respiratory infection as of April 2022, with a high proportion of syncytial virus infections mainly in children under 18 years of age (22.1%) and Human Rhinovirus/Enterovirus in patients with solid tumors and hematological disorders (48.8%), the latter was associated with a higher rate of hospitalization and ICU requirement in the individuals evaluated. CONCLUSIONS: Respiratory viruses other than SARS-CoV-2, such as Rhino/Enterovirus, RSV, and adenovirus, are circulating in the population at a clinic on the Colombian Caribbean coast. The findings should motivate public health authorities to conduct more thorough surveillance in the rest of the state.

Biofilm formation is correlated with low nutrient and simulated microgravity conditions in a Burkholderia isolate from the ISS water processor assembly.

The International Space Station (ISS) Water Processor Assembly (WPA) experiences intermittent dormancy in the WPA wastewater tank during water recycling events which promotes biofilm formation within the system. In this work we aimed to gain a deeper understanding of the impact of nutrient limitation on bacterial growth and biofilm formation under microgravity in support of biofilm mitigation efforts in exploration water recovery systems. A representative species of bacteria that is commonly cultured from the ISS WPA was cultured in an WPA influent water ersatz formulation tailored for microbiological studies. An isolate of Burkholderia contaminans was cultured under a simulated microgravity (SµG) treatment in a vertically rotating high-aspect rotating vessel (HARV) to create the low shear modeled microgravity (LSMMG) environment on a rotating wall vessel (RWV), with a rotating control (R) in the horizontal plane at the predetermined optimal rotation per minute (rpm) speed of 20. Over the course of the growth curve, the bacterial culture in ersatz media was harvested for bacterial counts, and transcriptomic and nutrient content analyses. The cultures under SµG treatment showed a transcriptomic signature indicative of nutrient stress and biofilm formation as compared to the R control treatment. Further analysis of the WPA ersatz over the course of the growth curve suggests that the essential nutrients of the media were consumed faster in the early stages of growth for the SµG treatment and thus approached a nutrient limited growth condition earlier than in the R control culture. The observed limited nutrient response may serve as one element to explain a moderate enhancement of adherent biofilm formation in the SµG treatment after 24 h. While nutrients levels can be modulated, one implication of this investigation is that biofilm mitigation in the ISS environment could benefit from methods such as mixing or the maintenance of minimum flow within a dormant water system in order to force convection and offset the response of microbes to the secondary effects of microgravity.

Revealing the hidden biodiversity of Antarctic and the Magellanic Sub-Antarctic Ecoregion: A comprehensive study of aquatic invertebrates from the BASE Project.

Background: Antarctica, its outlying archipelagoes and the Magellanic Subantarctic (MSA) ecoregion are amongst the last true wilderness areas remaining on the planet. Therefore, the publication, citation and peer review of their biodiversity data are essential. The new Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), a Chilean scientific initiative funded by the National Agency of Research and Innovation, contributes 770 new records of aquatic invertebrates as a point of reference for present-day biodiversity research at these latitudes. New information: The occurrence dataset presented here has never been released before and is the result of the systematic recording of occurrences of several taxa across the Antarctic, Subantarctic and Magellanic Subantarctic ecoregions. We collected data from marine and freshwater invertebrates across numerous samplings from 2008 to 2023. From the 770 occurrences, we identified 160 taxa, 125 at species level and 35 at the genus level. The database has been registered in the Global Biodiversity Information Facility (GBIF). The publication of this data paper was funded by the Belgian Science Policy Office (BELSPO, contract n°FR/36/AN1/AntaBIS) in the Framework of EU-Lifewatch as a contribution to the SCAR Antarctic biodiversity portal (biodiversity.aq).

Taxonomic reassessment of Tetrapygus niger (Arbacioida, Echinoidea): molecular and morphological evidence support its placement in Arbacia.

The echinoid genus Tetrapygus was initially described by L. Agassiz (1841) based on a single species, Tetrapygus niger Molina, 1782. Since the extensive work conducted by Mortensen (1935), Tetrapygus has received limited taxonomic attention over the past century. Recent discoveries of new fossil species of Arbacia Gray, 1835 from the upper Pliocene of northern Chile revealed striking morphological similarities between the two distinct Arbaciidae genera Arbacia and Tetrapygus. These findings compelled new investigations to evaluate the taxonomic status of these genera. Based on molecular mitochondrial (COI), nuclear (28S), and morphological evidence, Tetrapygus niger is here recovered as the sister species to Arbacia dufresnii, both species forming a clade within the phylogeny of South American species of Arbacia. Consequently, the diagnosis and description of Tetrapygus niger are here revised, and the species is reattributed to Arbacia, as previously proposed by A. Agassiz in Agassiz & Desor (1846) under the species name Arbacia nigra. An emended diagnosis of Arbacia is also proposed in light of these new findings.

Ecomorphology and Morphological Disparity of Caquetaia Kraussii (Perciformes: Cichlidae) in Colombia.

Understanding the interspecific morphological variability of Caquetaia kraussii (Perciformes: Cichlidae) between different localities in its distribution range is becoming essential, as this species constitutes a valuable resource for the economy and subsistence of the local human communities where it is endemic in Colombia and Venezuela. In order to develop efficient farming and handling plans for this species, a deep understanding of the factors and mechanisms generating morphological variability is crucial. This study analyzes the morphological variability of C. kraussii by using geometric morphometrics in four localities distributed between the Dique and North channels, which are part of the Bolívar department in Colombia. Likewise, the effect of environmental variables such as temperature (T°), dissolved oxygen (OD) and pH on morphological variability was analyzed using a partial least squares approach. The results show that environmental stress has an influence on ~10% of the body shape of C. kraussii, whereas ~90% of the body shape is not directly influenced by environmental parameters, suggesting an effect from stress related to sexual dimorphism. Similarly, the analyses show shape variation among localities, mainly between populations of lotic environments and those of lentic environments. This morphological disparity seems to be subject to environmental and sexual stresses in the different localities.

Scalability of an ACT-Based strategy for improving well-being in health care providers: A mix-method and preliminary evaluation of efficacy.

The burden of the COVID-19 pandemic has been mainly carried by health care providers. Technology-Mediated Interventions (TMI) seem to be a feasible alternative to increase access to behavioral health resources in this population. However, scaling-up treatments into TMI requires developing user-friendly, accepted, and accessible formats. A two-stage study was conducted to assess scalability of an Acceptance and Commitment Therapy (ACT) based strategy (named FACE COVID) delivered using technology. First, a mix-method design connected qualitative and quantitative data from health providers and ACT experts by which changes were performed to enhance scalability. Second, a pretest-posttest study was conducted to preliminary evaluate the efficacy of FACE COVID intervention on well-being, psychological distress, and psychological flexibility. Results showed a positive impact on well-being, but not distress and psychological flexibility. While this intervention has promising results, changes in dose intensity, social support, and mental health literacy could improve retention as well as increase opportunities to target distress and psychological flexibility in future studies.

A step-by-step guide to creating an academic surgery interest group: Review article.

An academic interest group in medicine is defined as a collective that can be made up of undergraduate students, residents, and/or teachers, who share as an object of interest the advancement and growth of a specific area of medicine. It is organized to carry out extracurricular academic and research activities. It is essential to stimulate participation in these interest groups, which allow the personal and professional growth of their members, being a tool that promotes and provides better opportunities for entry as candidates for graduate studies. The American College of Surgeons is one of the largest medical scientific societies with the participation of undergraduate students with an interest in surgery. This society mentions the benefits of participating in interest groups in surgery, specifically, it highlights the importance of contributing to these when looking for a surgical specialty, because they address issues such as: what is the mentioned specialty itself?, what are the details about the application process for each surgical specialty?, these groups can provide information on different residency programs, lifestyle benefits, and/or cons; in addition to improving practical skills through surgical technique workshops or various organized activities. Based on the above, the objective of this manuscript is to design a Step-by-step guide for the creation of a surgical interest group, in order to encourage participation by medical students, residents, and teachers in the research and academic field.

Publisher Correction: Spatial distribution of freshwater crustaceans in Antarctic and Subantarctic lakes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Leishmaniasis cutánea, a propósito de un caso / Cutaneous leishmaniasis, a purpose of a case

La Leishmaniasis es una enfermedad parasitaria catalogada como emer-gente y sin control debido al cambio en el perfil epidemiológico por el sur-gimiento de nuevos focos y urbanización del ciclo de transmisión. Se des-cribe el caso de un adolescente de la Comunidad Dos Ríos, del Cantón Taisha, quien presentó varias lesiones ulceradas, confirmándose diagnós-tico de Leishmaniasis Cutáneamediante estudio histológico, iniciándose tratamiento con sales de antimonio pentavalentes, logrando una resolución progresiva y paulatina de las lesiones. Destacándose la importancia del diagnóstico temprano, tratamiento supervisado, y seguimiento para preve-nir complicaciones.

Leishmaniasis is a parasitic, emergent and uncontrolled disease due to the change in the epidemiological profile for the appearance of new outbreaks and urbanization of the transmission cycle. A case of a 15-years-old ado-lescent, who is resident of the Community Dos Ríos located on the Taisha Canton, was described. The patient presented ulcerated lesions, confir-ming the diagnosis of Cutaneous Leishmaniasis through the histological study of the lesions, and starting intramuscular treatment with pentavalent antimony salts observing healing with a progressive and gradual resolution of the lesions and emphasizing the importance of early diagnosis, supervi-sed treatment, and monitoring to prevent complications.

Spatial distribution of freshwater crustaceans in Antarctic and Subantarctic lakes.

Antarctic and Subantarctic lakes are unique ecosystems with relatively simple food webs, which are likely to be strongly affected by climate warming. While Antarctic freshwater invertebrates are adapted to extreme environmental conditions, little is known about the factors determining their current distribution and to what extent this is explained by biogeography or climate. We explored the distribution of freshwater crustaceans (one of the most abundant and diverse group of organisms in Antarctic and Subantarctic lakes) across four biogeographic provinces (Continental Antarctic, CA; Maritime Antarctic, MA; Subantarctic islands, SA; and Southern Cool Temperate, SCT) based on the literature, predicting that species distribution would be determined by biogeography, spatial autocorrelation among regions (in relation to dispersal) and climate. We found that variation in species composition was largely explained by the joint effect of spatial autocorrelation and climate, with little effect of biogeography - only regions within the SA province had a clearly distinct species composition. This highlights a plausible main influence of crustacean dispersal - mainly through migratory seabirds - and suggests that some regions will be more affected by climate warming than others, possibly in relation to the existence of nearby sources of colonists.

Acciones fonoaudiológicas para niños con discapacidad múltiple dentro del aula de clase / Actions the speech-language pathologist for children with multiple disability inside the classroom of class

El presente artículo abarca el resultado de un conjunto de consideraciones teórico prácticas acerca de las necesidades comunicativas y sociales que presentan los niños con discapacidad múltiple en el aula de clase; asimismo, cómo el término discapacidad se encuentra en constante cambio y cómo la Ley estatutaria 1618 se apropia del concepto de discapacidad para cubrir todas las necesidades y garantizar la conformidad y buen trato hacia esta población. En este contexto, es importante abordar la manera como el Fonoaudiólogo empieza a ocupar un papel relevante en el aula, donde contribuye al desarrollo comunicativo, analiza y procura la mejora de las deficiencias que se presentan, buscando soluciones y propiciando actividades viables para aumentar el desarrollo social e interpersonal de la población educativa, la cual a su vez, se proyecta desde el aula de clase bajo una perspectiva inclusiva y dinamizadora del docente hacia una sociedad en donde todos los niños y niñas tienen el poder de comunicar y participar. Se propone mediante este artículo reflexionar sobre las acciones del fonoaudiólogo para favorecer la interacción comunicativa en el aula de clase con la población infantil con discapacidad múltiple.

This article covers the result of a set of theoretical- practical considerations about the communicative and social needs of children with multiple disabilities in classrooms. This, taking in account that disability is constantly changing concept and that the Statutory Law 1618 uses the concept of disability to ensure this population's good treatment, needs and guarantees. In this context, it is important to address how the speech therapist has started to occupy a relevant role in the classroom, contributing to the communicative development, analyzing and seeking to improve deficiencies, looking for solutions and making activities to increase the social and interpersonal development of the student population. With the teachers help, this population is projected from the classroom, under an inclusive and dynamic perspective, towards a society where all children have the power to communicate and participate. This article proposes a reflection on the speech therapist's actions to favor the interactive classroom communication with the child's population with multiple disabilities

Genetic structure and demographic inference of the regular sea urchin Sterechinus neumayeri (Meissner, 1900) in the Southern Ocean: The role of the last glaciation.

One of the most relevant characteristics of the extant Southern Ocean fauna is its resiliency to survive glacial processes of the Quaternary. These climatic events produced catastrophic habitat reductions and forced some marine benthic species to move, adapt or go extinct. The marine benthic species inhabiting the Antarctic upper continental shelf faced the Quaternary glaciations with different strategies that drastically modified population sizes and thus affected the amount and distribution of intraspecific genetic variation. Here we present new genetic information for the most conspicuous regular sea urchin of the Antarctic continental shelf, Sterechinus neumayeri. We studied the patterns of genetic diversity and structure in this broadcast-spawner across three Antarctic regions: Antarctic Peninsula, the Weddell Sea and Adélie Land in East Antarctica. Genetic analyses based on mitochondrial and nuclear markers suggested that S. neumayeri is a single genetic unit around the Antarctic continent. The species is characterized by low levels of genetic diversity and exhibits a typical star-like haplotype genealogy that supports the hypothesis of a single in situ refugium. Based on two mutation rates standardized for this genus, the Bayesian Skyline plot analyses detected a rapid demographic expansion after the Last Glacial Maximum. We propose a scenario of rapid postglacial expansion and recolonization of Antarctic shallow areas from a less ice-impacted refugium where the species survived the LGM. Considering the patterns of genetic diversity and structure recorded in the species, this refugium was probably located in East Antarctica.

Diabetes mellitus tipo 2 en pacientes con diagnóstico de glaucoma primario de ángulo abierto durante el período 2010-2014 / Type 2 diabetes mellitus in patients diagnosed with primary open angle glaucoma during the period 2010-2014

RESUMEN Objetivo La asociación entre diabetes mellitus tipo 2 y glaucoma primario de ángulo abierto aún no está claramente establecida. Este estudio tiene como objetivo identificar la frecuencia entre ambas patologías en pacientes del Hospital Teodoro Maldonado Carbo durante el período 2010-2014 Métodos Se realizó un estudio retrospectivo, de corte transversal, de proporción, en una muestra de 283 pacientes mayores de 30 años cuyo diagnóstico fue de GPAA (Glaucoma primario de ángulo abierto) confirmado mediante estudio de tonometría, gonioscopia, campimetría y ausencia de causas secundarias de aumento de PIO. Se utilizaron criterios de la ADA/OMS para establecer el diagnóstico de DM2. Resultados La frecuencia de pacientes con diabetes en pacientes con diagnóstico de GPAA, que fueron atendidos en consultorios de Emergencia, Endocrinología y Oftalmología del Hospital Regional Teodoro Maldonado Carbo, durante el período 2010-2014, fue de 26,15% (74 de 283 pacientes), con importantes diferencias entre sexo y lugar de residencia. Conclusiones: Se demostró la existencia de una alta proporción entre DM2 y GPAA mediante razón de proporción.

ABSTRACT Objective The association between diabetes mellitus type 2 (DM2) and Primary Open- Angle Glaucoma (POAG) is not clearly established yet. This study has the objective to identify the frequency of both diseases in patients of Teodoro Maldonado Carbo Hospital during the period 2010-2014. Methods A retrospective, cross-sectional frequency was conducted on a sample of 283 patients over age 30 whose diagnosis was confirmed by examination of POAG tonometry, gonioscopy, perimetry and absence of secondary causes of increased intraocular pressure. ADA/OMS criteria were used to establish the diagnosis of DM2. Results The frequency of patients with diabetes diagnosed with POAG patients who were treated at the services of Emergency, Endocrinology and Ophthalmology of the Regional Hospital Teodoro Maldonado Carbo, during the period 2010-2014, was 26.15% (74 of 283 patients) with significant differences between sex and place of residence. Conclusions The existence of a high proportion between DM2 and POAG was demonstrated by prevalence ratio.

Evaluation of Single Hydrogel Nanofiber Mechanics Using Persistence Length Analysis.

Polyelectrolyte hydrogel fibers can mimic the extracellular matrix and be used for tissue scaffolding. Mechanical properties of polyelectrolyte nanofibers are crucial in manipulating cell behavior, which metal ions have been found to enable tuning. While metal ions play an important role in manipulating the mechanical properties of the fibers, evaluating the mechanical properties of a single hydrated hydrogel fiber remains a challenging task and a more detailed understanding of how ions modulate the mechanical properties of individual polyelectrolyte polymers is still lacking. In this study, dark-field microscopy and persistence length analysis help directly evaluate fiber mechanics using electrospun fibers of poly(acrylic acid) (PAA), chitosan (CS), and ferric ions as a model system. By comparing the persistence length and estimated Young's modulus of different nanofibers, we demonstrate that persistence length analysis is a viable approach to evaluate mechanical properties of hydrated fibers. Ferric ions were found to create shorter and stiffer nanofibers, with Young's modulus estimated at a few kilopascals. Ferric ions, at low concentration, reduce the Young's modulus of PAA and PAA/CS fibers through the interaction between ferric ions and carboxylate groups. Such interaction was further supported by nanoscale infrared spectroscopy studies of PAA and PAA/CS fibers with different concentrations of ferric ions.

Genetics, Gene Flow, and Glaciation: The Case of the South American Limpet Nacella mytilina.

Glacial episodes of the Quaternary, and particularly the Last Glacial Maximum (LGM) drastically altered the distribution of the Southern-Hemisphere biota, principally at higher latitudes. The irregular coastline of Patagonia expanding for more than 84.000 km constitutes a remarkable area to evaluate the effect of Quaternary landscape and seascape shifts over the demography of near-shore marine benthic organisms. Few studies describing the biogeographic responses of marine species to the LGM have been conducted in Patagonia, but existing data from coastal marine species have demonstrated marked genetic signatures of post-LGM recolonization and expansion. The kelp-dweller limpet Nacella mytilina is broadly distributed along the southern tip of South America and at the Falkland/Malvinas Islands. Considering its distribution, abundance, and narrow bathymetry, N. mytilina represents an appropriate model to infer how historical and contemporary processes affected the distribution of intraspecific genetic diversity and structure along the southern tip of South America. At the same time, it will be possible to determine how life history traits and the ecology of the species are responsible for the current pattern of gene flow and connectivity across the study area. We conducted phylogeographic and demographic inference analyses in N. mytilina from 12 localities along Pacific Patagonia (PP) and one population from the Falkland/Malvinas Islands (FI). Analyses of the mitochondrial gene COI in 300 individuals of N. mytilina revealed low levels of genetic polymorphism and the absence of genetic differentiation along PP. In contrast, FI showed a strong and significant differentiation from Pacific Patagonian populations. Higher levels of genetic diversity were also recorded in the FI population, together with a more expanded genealogy supporting the hypothesis of glacial persistence of the species in these islands. Haplotype genealogy, and mismatch analyses in the FI population recognized an older and more complex demographic history than in PP. Demographic reconstructions along PP suggest a post-LGM expansion process (7.5 ka), also supported by neutrality tests, mismatch distribution and maximum parsimony haplotype genealogies. Migration rate estimations showed evidence of asymmetrical gene flow from PP to FI. The absence of genetic differentiation, the presence of a single dominant haplotype, high estimated migration rates, and marked signal of recent demographic growth, support the hypothesis of rapid post-glacial expansion in N. mytilina along PP. This expansion could have been sustained by larval and rafting-mediated dispersal of adults from northernmost populations following the Cape Horn Current System. Marked genetic differentiation between PP and FI could be explained through differences in their respective glacial histories. During the LGM, Pacific Patagonia (PP) was almost fully covered by the Patagonian Ice Sheet, while sheet coverage in the FI ice was restricted to small cirques and valleys. As previously recorded in the sister-species N. magellanica, the FI rather than represent a classical glacial refugium for N. mytilina, seems to represent a sink area and/or a secondary contact zone. Accordingly, historical and contemporary processes, contrasting glacial histories between the analyzed sectors, as well as life history traits constitute the main factors explaining the current biogeographical patterns of most shallow Patagonian marine benthic organisms.

Envejecimiento: Cambio estructurales y papel de la facilitación neuromuscular propioceptiva / Elderly: Structural changes and the role of the neuromuscular proprioceptive facilitation

En el mundo, el porcentaje de adultos mayores se encuentra en aumento, obligando al desarro-llo continuo de políticas en salud. En razón a los cambios morfológicos y estructurales propios del músculo esquelético durante el envejecimiento, que llevan a su deterioro, varios modelos de ejercicio han sido puestos a prueba, incluyendo el entrenamiento de la fuerza explosiva y la flexibilidad. La Facilitación Neuromuscular Propioceptiva, ha surgido como una alternativa de entrenamiento, gracias a los resultados positivos demostrados en el área de la prevención y la rehabilitación; sin embargo en el adulto mayor sano no ha sido posible demostrar dichos benefi-cios, presentándose por el contrario dificultades en la aplicación de los programas, dados por los tiempos necesarios para hacer tangibles los resultados y los riesgos que con su implementación se puedan presentar. Es necesario desarrollar nuevas investigaciones que involucren técnicas combinadas de entrenamiento, con el fin de comprender y optimizar la respuesta al ejercicio físico en el adulto mayor

Worldwide the percentage of elderly people is increasing, forcing the continued development of health policies. Due to structural and morphological characteristic changes of skeletal muscle during aging, leading to deterioration, several models of exercising have been tested, including the explosive strength and flexibility training, the Proprioceptive Neuromuscular Facilitation has emerged as an alternative training, because of the good results shown in the prevention and rehabilitation area. However in healthy elderly adults have not been possible to demonstrate those benefits, instead they have revealed difficulties in programs implementation, in part for the time needed to obtain tangible results and the risks involved with its implementation may arise. Furthermore, it is necessary to develop combined techniques involving training, in order to understand and optimize the response to exercise in the elderly.

An efficient method to find potentially universal population genetic markers, applied to metazoans.

BACKGROUND: Despite the impressive growth of sequence databases, the limited availability of nuclear markers that are sufficiently polymorphic for population genetics and phylogeography and applicable across various phyla restricts many potential studies, particularly in non-model organisms. Numerous introns have invariant positions among kingdoms, providing a potential source for such markers. Unfortunately, most of the few known EPIC (Exon Primed Intron Crossing) loci are restricted to vertebrates or belong to multigenic families. RESULTS: In order to develop markers with broad applicability, we designed a bioinformatic approach aimed at avoiding multigenic families while identifying intron positions conserved across metazoan phyla. We developed a program facilitating the identification of EPIC loci which allowed slight variation in intron position. From the Homolens databases we selected 29 gene families which contained 52 promising introns for which we designed 93 primer pairs. PCR tests were performed on several ascidians, echinoderms, bivalves and cnidarians. On average, 24 different introns per genus were amplified in bilaterians. Remarkably, five of the introns successfully amplified in all of the metazoan genera tested (a dozen genera, including cnidarians). The influence of several factors on amplification success was investigated. Success rate was not related to the phylogenetic relatedness of a taxon to the groups that most influenced primer design, showing that these EPIC markers are extremely conserved in animals. CONCLUSIONS: Our new method now makes it possible to (i) rapidly isolate a set of EPIC markers for any phylum, even outside the animal kingdom, and thus, (ii) compare genetic diversity at potentially homologous polymorphic loci between divergent taxa.