This research set as objective to quantify carbon stocks in aerial biomass of temperate communities of northern Durango, Mexico. The carbon concentration of several biomass components of 25 trees were quantified in the laboratory. Dasometric data of inventoried trees, together with alometric equations to estimate biomass and carbon concentrations were employed to estimate carbon expansion factors using stand volume. The carbon expansion factors were modeled as a function of the dasometric features of trees at the stand scale and the normal probabilistic density function was fitted to obtain information on the skewness of this parameter. The results showed that the carbon expansion factors are dependent of the mean tree height and they distributed normally. This information is important for the development of environmental management plans of forest ecosystems and will allow the broader use of forest inventory data.

Este estudio tuvo por objetivo la cuantificación del almacén de carbono en la biomasa aérea de comunidades forestales templadas del norte de Durango, México. Se estimaron los valores de la concentración de carbono de diversos componentes de biomasa de 25 árboles provenientes de bosques de coníferas. Datos dasométricos de rodales inventariados, junto con ecuaciones alométricas y concentraciones de carbono sirvieron para estimar los factores de expansión de carbono, utilizando los volúmenes por hectárea. Se modeló la dependencia de los factores de expansión de carbono en función de las características dasométricas de los árboles y se determinó la distribución probabilística de estos factores. Los resultados mostraron que los factores de expansión de carbono son dependientes de la altura promedio del rodal y se distribuyeron normalmente. Esta fuente de información es clave en el desarrollo de planes de manejo de servicios ambientales de los ecosistemas forestales y permitirá el uso más amplio de datos de inventarios convencionales.

Objective: Rhabdomyomas are benign tumors of the skeletal muscle and extracardiac rhabdomyomas are very rare. Methods/Results: We report one case of spermatic cord rhabdomyoma in a 28-year-old male. Conclusions: Genital rhabdomyomas are rare benign tumors. Rhabdomyomas should be considered in the clinicopathological differential diagnosis of tumors of the male genital tract.

Objetivo: Los rabdomiomas son tumores benignos del músculo esquelético cuya localización extracardiaca es rara. Métodos/Resultados: Presentamos un caso de rabdomioma de cordón espermático en un varón de 28 años de edad. Conclusiones: Los rabdomiomas genitales son tumores benignos poco frecuentes, y deben ser considerados en el diagnóstico diferencial de tumores del tracto genital masculino.

The high morbidity, high socioeconomic costs and lack of specific treatments are key factors that define the relevance of brain pathology for human health and the importance of research on neuronal protective agents. Epidemiological studies have shown beneficial effects of flavonoids on arteriosclerosis-related pathology in general and neurodegeneration in particular. Flavonoids can protect the brain by their ability to modulate intracellular signals promoting cellular survival. Quercetin and structurally related flavonoids (myricetin, fisetin, luteolin) showed a marked cytoprotective capacity in in vitro experimental conditions in models of predominantly apoptotic death such as that induced by medium concentrations (200 µM) of H2O2 added to PC12 cells in culture. Nevertheless, quercetin did not protect substantia nigra neurons in vivo from an oxidative insult (6-hydroxydopamine), probably due to difficulties in crossing the blood-brain barrier. On the other hand, treatment of permanent focal ischemia with a lecithin/quercetin preparation decreased lesion volume, showing that preparations that help to cross the blood-brain barrier may be critical for the expression of the effects of flavonoids on the brain. The hypothesis is advanced that a group of quercetin-related flavonoids could become lead molecules for the development of neuroprotective compounds with multitarget anti-ischemic effects.