Genotype by environment interaction for adult body weights of shrimp Penaeus vannamei when grown at low and high densitie

Shrimp is one of few marine species cultured worldwide for which several selective breeding programs are being conducted. One environmental factor that can affect the response to selection in breeding programs is the density at which the shrimp are cultured (low-medium-high). Phenotypic plasticity in the growth response to different densities might be accompanied by a significant genotype by environment interaction, evidenced by a change in heritabilities between environments and by a genetic correlation less than one for a unique trait between environments. Our goal was to understand whether different growth densities affect estimates of those genetic parameters for adult body weight (BW) in the Pacific white shrimp (Penaeus vannamei). BW heritabilities were significantly different between environments, with the largest at high density. These differences resulted from both an increased additive genetic variance and a decreased environmental variance when grown at high density. The genetic correlation between BWs at the two environmental conditions was significantly less than one. Whereas these results might be suggestive for carrying out shrimp selective breeding for BW under high density conditions, further understanding of genetic correlations between growth and reproductive traits within a given environment is necessary, as there are indications of reduced reproductive fitness for shrimp grown at high densities

Thirty-Seven Additional Microsatellite Loci in the Pacific Lion-Paw Scallop (\u3ci\u3eNodipecten subnodosus\u3c/i\u3e) and Cross-Amplification in Other Pectinids

We characterized 37 new microsatellite markers in the Pacific lion-paw scallop (Nodipecten subnodosus) and tested for cross-amplification in four other species. Genetic diversity was estimated using 24 individuals from the Lagoon Ojo de Liebre, B.C.S., Mexico. Allelic richness varied from 5 to 27 alleles per locus and the average expected heterozygosity was 0.76. Ten loci exhibited significant departure from Hardy–Weinberg equilibrium likely due to the presence of null alleles. Sixteen of these markers cross-amplified in closely related N. nodosus, while little or no amplification was observed in three Argopecten species

Thirty-Seven Additional Microsatellite Loci in the Pacific Lion-Paw Scallop (\u3ci\u3eNodipecten subnodosus\u3c/i\u3e) and Cross-Amplification in Other Pectinids

We characterized 37 new microsatellite markers in the Pacific lion-paw scallop (Nodipecten subnodosus) and tested for cross-amplification in four other species. Genetic diversity was estimated using 24 individuals from the Lagoon Ojo de Liebre, B.C.S., Mexico. Allelic richness varied from 5 to 27 alleles per locus and the average expected heterozygosity was 0.76. Ten loci exhibited significant departure from Hardy–Weinberg equilibrium likely due to the presence of null alleles. Sixteen of these markers cross-amplified in closely related N. nodosus, while little or no amplification was observed in three Argopecten species

Vegetation Changes Following Biosolids Applications at an Old Boer Lovegrass Pasture in Northern Sonora, México

Short grass prairies (Bouteloua-Aristida) are the main vegetation type in northern Sonora, México, however, factors such as land fragmentation, overgrazing, severe droughts and lack of infrastructure in most ranches poor grazing management has caused land degradation. Boer lovegrass (Eragrostis curvula var. conferta) is an introduced species planted to increase productivity on deteriorated rangelands. Forage production with Boer lovegrass increases two to three fold as compared to native grasses after range seeding but productivity declines as stands become old. Biosolids have been recognized as a useful soil amendment and source of nitrogen, phosphorus, organic matter and other nutrients, which can enhance soil physical properties as well as plant yield (US Environmental Protection Agency 1999, Kinney et al. 2006). These organic compounds of human origins may play an important role in rangelands increasing soil fertility, however data do not exist to justify its use in México. This study was conducted to evaluate forage responses of old Boer lovegrass stands to biosolids applications

Chitosan and Xyloglucan-Based Hydrogels: An Overview of Synthetic and Functional Utility

The development of new strategies for wound healing has resulted in the design of biomedical devices using polymers of natural origin. Hydrogels are biomaterials formed by three-dimensional polymeric networks that can retain large amounts of water or biological fluids, and smooth texture similar to living tissue. Chitosan is a linear polysaccharide, (1-4)-2-amino-2deoxy-ß-D-glucan, which has desirable features such as biocompatibility, non-toxicity, hemostasis and antibacterial character. Xyloglucans have different applications in tissue engineering for their physicochemical properties, biocompatibility and control of cell expansion. Hydrogels had been made of homogeneous mixtures prepared of chitosan and purified xyloglucan, followed by a freeze-drying process to develop a flexible and porous structure. Additionally, their mechanical properties such as porosity, solubility, biodegradation, and the antibacterial activity of the hydrogels are studied. The results suggest that the incorporation of xyloglucan favors the characteristics from chitosan-based hydrogels, providing a promising alternative for application in biomaterials with antimicrobial activity

Ecological Connectivity of Trypanosoma cruzi Reservoirs and Triatoma pallidipennis Hosts in an Anthropogenic Landscape with Endemic Chagas Disease

Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats.This study was funded by the Secretaria de Salud and Consejo Nacional de Ciencia y Tecnología (CONACyt) project MOR-2004-CO2-012 to JMR, and by the Universidad Nacional Autónoma de México (PAPIIT project 225408 to VS-C, and the Sistema de Informática para la Biodiversidad y el Ambiente [SIBA], and Tecnologías para la Universidad de la Información y la Computación. AEGC was funded with a scholarship from CONACyT for a M. Sc. degree in vector-borne diseases at the Instituto Nacional de Salud Publica. CNIC is funded with a scholarship from CONACyT for studies at the graduate program in Biomedical Sciences of the Universidad Nacional Autonoma de Mexico

Caracterización clínica del síndrome nefrótico en infantes de Neiva

Nephrotic Syndrome is a chronic glomerular disease more commonly found in children. The United States has an annual incidence of 2.0 to 2.7 cases per 100,000 children and an accumulated prevalence of 16 per 100,000. The department of Huila, Colombia lacks up-to-date information that would allow the establishment and standardisation of clear objectives in the diagnosis and treatment of this disease in the paediatric population. Equipment and Methods. A descriptive, cross-sectional study was carried out of the clinical and epidemiological characteristics of Nephrotic Syndrome in children treated at Neiva's Hospital Universitario between March 2011 and December 2013. The information was collected by reviewing clinical records. 67 patients with a confirmed diagnosis were included. Results. The average age of onset was 46 months (0-175 months) and patients were mainly male (53.7%). 19% showed cortical resistance, the most common disease was focal segmental glomerulosclerosis (FSGS) (60%). High blood pressure at the beginning, or during follow-up, haematuria, hypocomplementemia and persistent dyslipidaemia are associated with cortical resistance (P < 0.01). Changes in the anthropometric measurements of height and weight were analysed in the patients at the beginning and at the end of the follow-up (P < 0.01). Conclusion. Nephrotic Syndrome is a common disease in the region of Neiva and the presence of cortical resistance and the progression to chronic kidney disease and death is also seen. Therefore, early diagnosis, treatment and timely follow-up is imperative in order to avoid complications in the future.El Síndrome Nefrótico es la enfermedad glomerular crónica más prevalente en pediatría, en los Estados Unidos presenta una incidencia anual de 2,0 a 2,7 casos por 100.000 niños, y una prevalencia acumulada de 16 por 100.000 (1). El departamento del Huila, carece de información actualizada que permita establecer y unificar objetivos claros en el diagnóstico y tratamiento de esta patología en la población pediátrica. Materiales y Métodos. Se realizó un estudio descriptivo tipo corte transversal de las características clínicas y epidemiológicas del Síndrome Nefrótico en niños atendidos en el Hospital Universitario de Neiva, entre marzo de 2011 y diciembre de 2013; la información se recolectó mediante revisión de historias clínicas. Se incluyeron 67 pacientes con diagnóstico confirmado. Resultados. la edad promedio de debut fue 46 meses (0-175 meses), en su mayoría de género masculino (53,7%). El 19% presentaron corticoresistencia, la patología más frecuente fue la glomeruloesclerosis focal y segmentaria (GEFS) (60%). La presencia de hipertensión arterial al debut o durante el seguimiento, hematuria, hipocomplementemia y dislipidemia persistente se asoció con cortico-resistencia (P < 0,01). Se observó cambios en las medidas antropométricas de talla y peso en los pacientes al inicio y final del seguimiento (P < 0,01). Conclusión. El Síndrome Nefrótico en esta región es una patología prevalente, con presencia de cortico-resistencia y progresión a enfermedad renal crónica y muerte, por lo tanto es imperativo su diagnóstico temprano, tratamiento y seguimiento oportuno para evitar complicaciones a futuro