Translational Selection on Codon Usage in Xenopus laevis

A correspondence analysis of codon usage in Xenopus laevis revealed that the first axis is strongly correlated with the base composition at third codon positions. The second axis discriminates between putatively highly expressed genes and the other coding sequences, with expression levels being confirmed by the analysis of Expressed sequence tag frequencies. The comparison of codon usage of the sequences displaying the extreme values on the second axis indicates that several codons are statistically more frequent among the highly expressed (mainly housekeeping) genes. Translational selection appears, therefore, to influence synonymous codon usage in Xenopus

Identification of a novel herpesvirus associated with a penile proliferative lesion in a beluga (Delphinapterus leucas)

The carcass of an adult male beluga (Delphinapterus leucas) was found beach cast in 2008 on the shore of the St. Lawrence Estuary at Rivière-Ouelle, Quebec, Canada. The carcass was transported to the Faculté de médecine vétérinaire of the Université de Montréal for postmortem examination. Aspiration pneumonia was the probable cause of death. Necropsy revealed a focal papilloma-like penile lesion, characterized by focal mucosal thickening with disorganization of the epithelial layers and lymphoplasmacytic infiltration. A pan-herpesvirus nested PCR assay on frozen tissue from the penile lesion was positive. The PCR product sequencing revealed a partial herpesvirus DNA polymerase (DPOL) gene sequence of 600 nucleotides. Its nearest nucleotide identity was with the partial DPOL gene of an alphaherpesvirus, bovine herpesvirus 5 (79.5% identity). It also shared high identity with several other marine mammal herpesviruses (50.2 to 77.3% identity). This new herpesvirus was tentatively named beluga whale herpesvirus (BWHV). Virus isolation was unsuccessful. The pathogenic potential of BWHV is unknown, but the evaluation of archived tissues suggests that the virus is endemic in the St. Lawrence Estuary beluga population

How VASP enhances actin-based motility

The function of vasodilator-stimulated phosphoprotein (VASP) in motility is analyzed using a biomimetic motility assay in which ActA-coated microspheres propel themselves in a medium containing actin, the Arp2/3 complex, and three regulatory proteins in the absence or presence of VASP. Propulsion is linked to cycles of filament barbed end attachment-branching-detachment-growth in which the ActA-activated Arp2/3 complex incorporates at the junctions of branched filaments. VASP increases the velocity of beads. VASP increases branch spacing of filaments in the actin tail, as it does in lamellipodia in living cells. The effect of VASP on branch spacing of Arp2/3-induced branched actin arrays is opposed to the effect of capping proteins. However, VASP does not compete with capping proteins for binding barbed ends of actin filaments. VASP enhances branched actin polymerization only when ActA is immobilized on beads or on Listeria. VASP increases the rate of dissociation of the branch junction from immobilized ActA, which is the rate-limiting step in the catalytic cycle of site-directed filament branching

Miocene semidiurnal tidal rhythmites in Madre de Dios, Peru: Reply

Hoorn et al. commented on the following aspects of our 2005 Geology article: 1) the age of the sediments, 2) the interpreted brackish water affi nity of the studied deposits, and 3) the possible connection between Paraná and western Amazonia depositional systems during the late Miocene

Reversible, electric-field induced magneto-tonic control of magnetism in mesoporous cobalt ferrite thin films

The magnetic properties of mesoporous cobalt ferrite films can be largely tuned by the application of an electric field using a liquid dielectric electrolyte. By applying a negative voltage, the cobalt ferrite becomes reduced, leading to an increase in saturation magnetization of 15% (M) and reduction in coercivity (H) between 5-28%, depending on the voltage applied (−10 V to −50 V). These changes are mainly non-volatile so after removal of −10 V M remains 12% higher (and H 5% smaller) than the pristine sample. All changes can then be reversed with a positive voltage to recover the initial properties even after the application of −50 V. Similar studies were done on analogous films without induced porosity and the effects were much smaller, underscoring the importance of nanoporosity in our system. The different mechanisms possibly responsible for the observed effects are discussed and we conclude that our observations are compatible with voltage-driven oxygen migration (i.e., the magneto-ionic effect)

Actividades recreativas y conservación en Áreas Naturales Protegidas en el centro de México: un enfoque desde los Socioecosistemas

La Dra. Tizbe Teresa Arteaga Reyes participó: (i) como corresponsable del proyecto de investigación Parque Nacional Nevado de Toluca: un laboratorio socio-ambiental en la innovación de políticas para la gestión de parques nacionales, en el marco del Convenio Bilateral México-Francia, financiado por el CONACYT; (ii) en la dirección de la tesis (Tutora Académica) de Doctorado en Ciencias Agropecuarias y Recursos Naturales de la C. Nadinne Ivette González Romero; y (iii) en la redacción de este artículo científico como autora por correspondencia, resultado del proyecto de investigación y la dirección de tesis doctoral.The Protected Area of Flora and Fauna Nevado de Toluca (APFFNT) does not consider the double mandate to reduce conflicts between use and protection of Natural Protected Areas (NPAs), which requires integrating the socio-ecosystems approach. The objective of the present study was to analyze the recreational activity in three socio-ecological units within the socio-ecosystem APFFNT, in order to understand the interaction and compatibility between recreation and conservation in NPAs. From a literature review, direct observation, field trips and semi-structured interviews, it was observed that within the management of the three socio-ecological units, conservation actions and recreational activities coexist that are developed in social and ecologically fragile and complex contexts; however, these activities have not been carried out in a formal way, due to the limited synergies between actors and to failures in the application and enforcement of existing regulation. The socio-ecosystem approach allows to analyze recreational activities and the visualization of dynamics, temporality and complexity of the interactions of socio-ecosystem components to implement management and governance alternatives that contribute to preventing and reducing conservation-management-environmental degradation conflicts.Al Consejo Nacional de Ciencia y Tecnología (CONACYT) por el financiamiento para: (i) el Doctorado en Ciencias Agropecuarias y Recursos Naturales de la Mtra. González Romero y (ii) el proyecto de investigación Parque Nacional Nevado de Toluca: un laboratorio socio-ambiental en la innovación de políticas para la gestión de parques nacionales, en el marco del Convenio Bilateral México-Francia

Progressive Structural Defects in Canine Centronuclear Myopathy Indicate a Role for HACD1 in Maintaining Skeletal Muscle Membrane Systems

Mutations in HACD1/PTPLA cause recessive congenital myopathies in humans and dogs. Hydroxyacyl-coA dehydratases are required for elongation of very long chain fatty acids, and HACD1 has a role in early myogenesis, but the functions of this striated muscle-specific enzyme in more differentiated skeletal muscle remain unknown. Canine HACD1 deficiency is histopathologically classified as a centronuclear myopathy (CNM). We investigated the hypothesis that muscle from HACD1-deficient dogs has membrane abnormalities in common with CNMs with different genetic causes. We found progressive changes in tubuloreticular and sarcolemmal membranes and mislocalized triads and mitochondria in skeletal muscle from animals deficient in HACD1. Furthermore, comparable membranous abnormalities in cultured HACD1-deficient myotubes provide additional evidence that these defects are a primary consequence of altered HACD1 expression. Our novel findings, including T-tubule dilatation and disorganization, associated with defects in this additional CNM-associated gene provide a definitive pathophysiologic link with these disorders, confirm that dogs deficient in HACD1 are relevant models, and strengthen the evidence for a unifying pathogenesis in CNMs via defective membrane trafficking and excitation-contraction coupling in muscle. These results build on previous work by determining further functional roles of HACD1 in muscle and provide new insight into the pathology and pathogenetic mechanisms of HACD1 CNM. Consequently, alterations in membrane properties associated with HACD1 mutations should be investigated in humans with related phenotypes

Relational dynamics of recreational activities in the Nevado de Toluca Flora and Fauna Protection Area, Mexico: A Social Network Analysis approach

La gestión de las actividades recreativas en Áreas Naturales Protegidas es compleja por el número de actores sociales que aprovechan y administran los recursos naturales con actividades, intereses y necesidades distintas. El objetivo del estudio fue analizar la dinámica relacional entre los actores sociales involucrados en tres Unidades Socio‐Ecológicas, y sus implicaciones en el manejo de las actividades recreativas en el Área de Protección de Flora y Fauna Nevado de Toluca, México. A partir de una revisión de literatura, entrevistas semiestructuradas y Análisis de Redes Sociales se encontró que los actores sociales presentes, no son suficientes para un buen manejo de las actividades recreativas. La principal función de todos los actores sociales es la conservación de recursos naturales, pero también asumen funciones para el manejo de las actividades recreativas. La dinámica entre actores sociales presenta lazos débiles e intermitencia en las relaciones debido a la ausencia de vínculos institucionalizados y metas comunes. Es necesario desarrollar redes de colaboración donde los actores asuman corresponsabilidades y acciones conjuntas para la planeación y manejo de las actividades recreativas.The management of recreational activities in Natural Protected Areas is complex due to the number of stakeholders that use and manage natural resources, their varying activities, interests and needs. The aim of the study was to analyse the relational dynamics between stakeholders involved in three Socio‐Ecological Units, and their implications in the management of recreational activities in the Nevado de Toluca Flora and Fauna Protected Area, Mexico. From literature review, semi‐structured interviews and application of Social Network Analysis tools, it was identified that not all the stakeholders that should be involved for efficient management of recreational activities are effectively included . Although their main function is the conservation of natural resources, they also assume functions for the management of recreational activities. They present weak ties and lack of consistency in their relationships, due to the absence of institutionalized links and common goals. It is necessary to move towards collaboration networks where stakeholders assume joint responsibilities and actions for the planning and management of recreational activities

Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS

We report the discovery of 74 new pulsating DA white dwarf stars, or ZZ Cetis, from the data obtained by the Transiting Exoplanet Survey Satellite mission, from Sectors 1 to 39, corresponding to the first 3 cycles. This includes objects from the Southern hemisphere (Sectors 1–13 and 27–39) and the Northern hemisphere (Sectors 14–26), observed with 120 s- and 20 s-cadence. Our sample likely includes 13 low-mass and one extremely low-mass white dwarf candidate, considering the mass determinations from fitting Gaia magnitudes and parallax. In addition, we present follow-up time series photometry from ground-based telescopes for 11 objects, which allowed us to detect a larger number of periods. For each object, we analysed the period spectra and performed an asteroseismological analysis, and we estimate the structure parameters of the sample, i.e. stellar mass, effective temperature, and hydrogen envelope mass. We estimate a mean asteroseismological mass of 〈Msis〉 = 0.635 ± 0.015 M⊙, excluding the candidate low or extremely low-mass objects. This value is in agreement with the mean mass using estimates from Gaia data, which is 〈Mphot〉 = 0.631 ± 0.040 M⊙, and with the mean mass of previously known ZZ Cetis of 〈M*〉 = 0.644 ± 0.034 M⊙. Our sample of 74 new bright ZZ Cetis increases the number of known ZZ Cetis by ∼20 per cent