Effect of Prenatal Exposure to Lead on Estrogen Action in the Prepubertal Rat Uterus

Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals and causes infertility and other adverse effects. The present paper investigated the effects of prenatal exposure to lead on different parameters of estrogen stimulation in the uterus of the prepubertal rat. In prenatally and perinatally exposed rats, estrogen-induced endometrial eosinophilia, endometrial stroma edema, and eosinophil migration towards the endometrium, and uterine luminal epithelial hypertrophy are enhanced while several other responses to estrogen appear unchanged. These effects may contribute to decrease in fertility following prenatal exposure to lead. The striking difference between most of these effects of prenatal exposure and the previously reported effects of chronic exposure to lead suggests that prenatal exposure to lead may neutralize the effects of chronic exposure to lead, providing partial protection of cell function against the adverse effects of chronic exposure to lead. We propose that the mechanism involved, named imprinting or cell programming, persisted through evolution as a nongenetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation

Answer to photo quiz: Tunga penetrans

For both patients, considering the characteristics of the lesions, the epidemiological history of travel, and the microscopic study, a diagnosis of tungiasis was made. Tunga penetrans (sand flea) is a hematophagous flea 1 mm in length, whose habitat is warm, dry, sandy soils. This flea is widely distributed in parts of East and West Africa, South America, and the Caribbean and in countries bordering the Indian Ocean. This flea presents a wide range of wild and domestic hosts, humans being an accidental host. Occasionally, tourists from developed countries are diagnosed with tungiais after becoming infected in areas where the disease is endemic...

Overfishing drivers and opportunities for recovery in small-scale fisheries of the Midriff islands region, Gulf of California, Mexico: The role of land and sea institutions in fisheries sustainability

Institutions play an important role in shaping individual incentives in complex social-ecological systems, by encouraging or discouraging resource overuse. In the Gulf of California, Mexico, there is widespread evidence of declines in small-scale fishery stocks, largely attributed to policy failures. We investigated formal and informal rules-in-use regulating access and resource use by small-scale fishers in the two most important fishing communities of the Midriff Islands region in the Gulf of California, which share several target species and fishing grounds. The Midriff Islands region is a highly productive area where sustainable use of fisheries resources has been elusive. Our study aimed to inform policy by providing information on how management and conservation policies perform in this unique environment. In addition, we contrast attributes of the enabling conditions for sustainability on the commons in an effort to better understand why these communities, albeit showing several contrasting attributes of the above conditions, have not developed sustainable fishing practices. We take a novel, comprehensive institutional approach that includes formal and informal institutions, incorporating links between land (i.e., communal land rights) and sea institutions (i.e., fisheries and conservation policies) and their effects on stewardship of fishery resources, a theme that is practically unaddressed in the literature. Insufficient government support in provision of secure rights, enforcement and sanctioning, and recognition and incorporation of local arrangements and capacities for management arose as important needs to address in both cases. We highlight the critical role of higher levels of governance, that when disconnected from local practices, realities, and needs, can be a major impediment to achieving sustainability in small-scale fisheries, even in cases where several facilitating conditions are met.Resumen: Las instituciones desempeñan un papel importante en la determinación de los incentivos individuales en sistemas socio-ecológicos complejos, alentando o desalentando la sobreexplotación. En el Golfo de California, México, existe amplia evidencia de una marcada disminución en la abundancia de recursos pesqueros de pequeña escala o artesanales, atribuida a fracasos en las políticas de manejo. Este trabajo investiga las reglas formales e informales en uso para regular acceso y uso de recursos por parte de pescadores artesanales en las dos comunidades pesqueras más importantes de la Región de las Grandes Islas, Golfo de California. A pesar de su elevada productividad biológica, el uso sustentable de los recursos marinos en esta región ha sido difícil de alcanzar. Este trabajo proporcionamo información para optimizar el desempeño de los instrumentos de manejo y conservación de recursos marinos presentes en este ambiente único. Además, contrastamos los atributos de las condiciones que facilitan la sustentabilidad en el uso de recursos de uso común, para comprender mejor por qué estas comunidades no han logrado incorporar de manera duradera prácticas de pesca sustentables, a pesar de presentar, en el caso particular de una de ellas, varias condiciones propicias. Adoptamos un enfoque institucional novedoso e integral que incluye instituciones formales e informales, e incorpora los vínculos entre reglas relativas a la tenencia de la tierra (ej. derechos de uso comunales) y del ámbito marino (de pesca y conservación), y sus efectos sobre el cuidado de los recursos marinos, un tópico prácticamente sin abordar en la literatura. Surgen como limitantes importantes en ambos casos, un apoyo gubernamental insuficiente tanto en la provisión de derechos de pesca seguros como en la fiscalización y la aplicación de sanciones, y la falta de reconocimiento e incorporación de arreglos institucionales y capacidades de manejo locales en instancias formales de decisión. Resaltamos el papel fundamental que cumplen los niveles de gobernanza más elevados, los que al estar desvinculados de las prácticas, realidades y necesidades locales, pueden obstaculizar de manera significativa el alcance de la sustentabilidad en pesquerías artesanales, incluso cuando varias condiciones favorables están presentes.Fil: Cinti, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. University Of Arizona; Estados UnidosFil: Duberstein, Jennifer N.. University Of Arizona; Estados UnidosFil: Torreblanca, Esteban. Pronatura Noroeste, A.C.; ArgentinaFil: Moreno Báez, Marcia. University Of Arizona; Estados Unido

The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC

We analyzed the triple Higgs boson self-coupling at future $e^{+}e^{-}$ colliders energies, with the reactions $e^{+}e^{-}\to b \bar b HH, t \bar t HH$. We evaluate the total cross-sections for both $b\bar bHH$ and $t\bar tHH$, and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. We vary the triple coupling $\kappa\lambda_{3H}$ within the range $\kappa=-1$ and +2. The numerical computation is done for the energies expected to be available at a possible Future Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1500$ $GeV$ and a luminosity 1000 $fb^{-1}$. Our analysis is also extended to a center-of-mass energy 3 $TeV$ and luminosities of 1000 $fb^{-1}$ and 5000 $fb^{-1}$. We found that for the process $e^{+}e^{-}\to b \bar b HH$, the complete calculation differs only by 3% from the approximate calculation $e^{+}e^{-}\to ZHH(Z\to b\bar b)$, while for the process $e^{+}e^{-}\to t \bar tHH$, the expected number of events, considering the decay products of both $t$ and $H$, is not enough to obtain an accurate determination of the triple Higgs boson self-coupling.Comment: 19 pages, 12 figure

Producción de un tensoactivo biológico

This paper summarizes the scale up work performed at the Colombian Petroleum Institute on a process to produce at pilot plant level a biosurfactant of the rhamnolipid type. By examination of both the activation conditions of the microorganism and design aspects of the broth, a stable condition was achieved which consistently triggers the production mechanisms and thus it was obtained a significant increment in biosurfactant productivity. The biological surfactant exhibited high efficiency in applications such as hydrocarbon biodegradation in saline environments, corrosion inhibition, and crude oil recovery from storage tank bottom sludges.En este artículo se resume el estudio realizado en el Instituto Colombiano del Petróleo (ICP), para escalar desde el laboratorio hasta la planta piloto, un proceso para la producción de biosurfactante tipo ramnolípido. Mediante el examen de las condiciones de activación del microorganismo y del diseño del medio de cultivo se establecieron condiciones que en forma sistemática disparan el mecanismo productor del microorganismo y permiten incrementar la productividad del biosurfactante. Se demostró la alta eficiencia de este aditivo biológico en aplicaciones, tales como biodegradación de hidrocarburos en medios salinos, control de la corrosión y recuperación de crudo a partir de lodos de fondos de tanques de almacenamiento.

Características del cibario y órganos genitales internos en la identificación de Lutzomyia longipalpis hembra

El control epidemiológico de la leishmaniosis canina requiere establecer fehacientemente la existencia del vector de la enfermedad. El flebótomo Lutzomyia longipalpis es el transmisor de la leishmaniosis visceral del perro. Dado que en el nordeste argentino existen otras especies de flebótomos del mismo género, la presente investigación tuvo como objetivo verificar la eficacia de algunos descriptores anatómicos microscópicos para constatar la presencia de hembras de L. longipalpis. De los 63 descriptores aptos para este fin, se seleccionaron algunos ubicados en la cabeza del insecto (cibario y antena) y en la región abdominal caudal (genitales internos). Estos descriptores se revelaron como los más relevantes y factibles de ser distinguidos, permitiendo una rápida y segura identificación del flebótomo. Se espera que esta información resulte útil para los encargados del control epizootiológico de la leishmaniosis

Características epidemiológicas y desenlaces de la infección por SARS-CoV-2 en pacientes con patologías reumáticas: primer reporte del registro argentino SAR-COVID

Con el fin de evaluar el impacto de la infección por SARS-CoV-2 en pacientes con enfermedades reumáticas, la Sociedad Argentina de Reumatología desarrolló el Registro Nacional de Pacientes con Enfermedades Reumáticas y COVID-19 (SAR-COVID). El objetivo del presente trabajo fue evaluar las características sociodemográficas y clínicas de los pacientes con enfermedades reumáticas e infección por SARS-CoV-2 incluidos en el registro SAR-COVID y describir las complicaciones y desenlaces de la COVID-19 en esta población. Material y métodos: SAR-COVID es un registro nacional, multicéntrico y observacional, en el cual se incluyen de manera consecutiva pacientes ≥18 años de edad, con diagnóstico de alguna enfermedad reumática que hayan cursado infección por SARS-CoV-2. Se consignan datos sociodemográficos, comorbilidades, enfermedad reumática y su tratamiento, características clínicas, laboratorio, complicaciones y tratamientos de la infección por SARS-CoV-2. Resultados: se incluyeron 525 pacientes, con una edad media de 51.3 años (DE 15.2). Las enfermedades reumatológicas más frecuentes fueron artritis reumatoidea (40.4%), lupus eritematoso sistémico (14.9%) y espondiloartritis (8.2%). El 72.9% recibía tratamiento inmunosupresor o inmunomodulador al momento del inicio de la infección y 36.9% glucocorticoides. En la mayoría de los casos, el diagnóstico de infección por SARS-CoV-2 se llevó a cabo mediante RT-PCR (95%), 39.4% en la consulta externa, 32.2% en el departamento de urgencias, y 14.7% durante la hospitalización. La mayoría de los pacientes presentaron síntomas, siendo los más frecuentes fiebre (56.2%), tos (46.7%) y cefalea (39.2%). Durante la infección, 35.1% requirieron hospitalización y 11.6% en unidad de cuidados intensivos. El 75.1% se recuperó completamente, 8.4% presentó secuelas y 6.9% murieron a causa de COVID-19. Conclusión: en este primer reporte del registro SAR-COVID encontramos una amplia distribución de enfermedades reumáticas. La mayoría de los pacientes tuvieron una buena evolución de la infección, sin embargo un 7% falleció como consecuencia de la misma, datos comparables a los reportados por otros registros latinoamericanos con poblaciones similares

Soil net nitrogen mineralisation across global grasslands

Soil nitrogen mineralisation (N-min), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net N-min) varies with soil properties and climate. However, because most global-scale assessments of net N-min are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net N-min across 30 grasslands worldwide. We find that realised N-min is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. Potential N-min only weakly correlates with realised N-min, but contributes to explain realised net N-min when combined with soil and climatic variables. We provide novel insights of global realised soil net N-min and show that potential soil net N-min data available in the literature could be parameterised with soil and climate data to better predict realised N-min

Transcriptional profile of the homologous recombination machinery and characterization of the EhRAD51 recombinase in response to DNA damage in Entamoeba histolytica

<p>Abstract</p> <p>Background</p> <p>In eukaryotic and prokaryotic cells, homologous recombination is an accurate mechanism to generate genetic diversity, and it is also used to repair DNA double strand-breaks. <it>RAD52 </it>epistasis group genes involved in recombinational DNA repair, including <it>mre11, rad50, nsb1/xrs2, rad51, rad51c/rad57, rad51b/rad55, rad51d, xrcc2, xrcc3, rad52, rad54, rad54b/rdh54 </it>and <it>rad59 </it>genes, have been studied in human and yeast cells. Notably, the RAD51 recombinase catalyses strand transfer between a broken DNA and its undamaged homologous strand, to allow damaged region repair. In protozoan parasites, homologous recombination generating antigenic variation and genomic rearrangements is responsible for virulence variation and drug resistance. However, in <it>Entamoeba histolytica </it>the protozoan parasite responsible for human amoebiasis, DNA repair and homologous recombination mechanisms are still unknown.</p> <p>Results</p> <p>In this paper, we initiated the study of the mechanism for DNA repair by homologous recombination in the primitive eukaryote <it>E. histolytica </it>using UV-C (150 J/m²) irradiated trophozoites. DNA double strand-breaks were evidenced in irradiated cells by TUNEL and comet assays and evaluation of the EhH2AX histone phosphorylation status. In <it>E. histolytica </it>genome, we identified genes homologous to yeast and human RAD52 epistasis group genes involved in DNA double strand-breaks repair by homologous recombination. Interestingly, the <it>E. histolytica </it>RAD52 epistasis group related genes were differentially expressed before and after UV-C treatment. Next, we focused on the characterization of the putative recombinase EhRAD51, which conserves the typical architecture of RECA/RAD51 proteins. Specific antibodies immunodetected EhRAD51 protein in both nuclear and cytoplasmic compartments. Moreover, after DNA damage, EhRAD51 was located as typical nuclear <it>foci</it>-like structures in <it>E. histolytica </it>trophozoites. Purified recombinant EhRAD51 exhibited DNA binding and pairing activities and exchanging reactions between homologous strands <it>in vitro</it>.</p> <p>Conclusion</p> <p><it>E. histolytica </it>genome contains most of the RAD52 epistasis group related genes, which were differentially expressed when DNA double strand-breaks were induced by UV-C irradiation. In response to DNA damage, EhRAD51 protein is overexpressed and relocalized in nuclear <it>foci</it>-like structures. Functional assays confirmed that EhRAD51 is a <it>bonafide </it>recombinase. These data provided the first insights about the potential roles of the <it>E. histolytica </it>RAD52 epistasis group genes and EhRAD51 protein function in DNA damage response of this ancient eukaryotic parasite.</p