¿Puede la disponibilidad temporal de datos determinar el calentamiento percibido por las tribus nómadas de mongoles cerca de las montañas Khangai?

Temperatures changes can be difficult to infer from changes in vegetation patterns or other ecological changes, yet warming can be inferred through changes in the habits of people who live in close connection with their natural environment. Herders near the Khangai Mountains of central Mongolia have perceived a warming trend in recent years. Since it is difficult to determine the exact time period over which perceived warming has occurred, we examined the statistical difference in changes based on the length of data and the specific period of record used in the analysis. We used temperature data from five meteorological stations for up to 50 years (1961-2010). We examined varying lengths of record from 15 to 50 years with varying start periods (1961 through 1986), based on the length of record. We found that the most statistically significant changes occurred for the longest time periods and for the annual average minimum temperatures. We also found that one very cold winter, in particular 2009-2010 decreased the warming trend and for shorter periods of record reduced the statistical significance.Los cambios de temperatura pueden ser difíciles de inferir a partir de los cambios en los patrones de vegetación u otros cambios ecológicos. Sin embargo, el calentamiento se puede inferir a través de cambios en los hábitos de las personas que viven en estrecha relación con su entorno natural. Los pastores de las montañas de Mongolia central, cerca deKhangai, perciben una tendencia hacia el calentamiento en los últimos años. Ya que resulta difícil determinar el período de tiempo exacto durante el que se ha producido el calentamiento, se analizó la diferencia estadística de los cambios en función de la longitud de los datos y el período de registros utilizado en el análisis. Hemos utilizado los datos de temperatura de cinco estaciones meteorológicas con 50 años de registros (1961-2010). Se examinaron diferentes longitudes de registro (de 15 a 50 años) con períodos de inicio diferentes (1961 a 1986). Se comprobó que los cambios estadísticamente más significativos se registran en los períodos más largos y considerando las temperaturas mínimas medias anuales. También se encontró que un invierno muy frío, en particular (2009-2010) disminuyó la tendencia al calentamiento

Characterization of Melan-A reactive memory CD8+ T cells in a healthy donor.

Melan-A specific CD8+ T cells are thought to play an important role against the development of melanoma. Their in vivo expansion is often observed with advanced disease. In recent years, low levels of Melan-A reactive CD8+ T cells have also been found in HLA-A2 healthy donors, but these cells harbor naive characteristics and are thought to be mostly cross-reactive for the Melan-A antigen. Here, we report on a large population of CD8+ T cells reactive for the Melan-A antigen, identified in one donor with no evidence of melanoma. Interestingly, this population is oligoclonal and displays a clear memory phenotype. However, a detailed study of these cells indicated that they are unlikely to be directly specific for melanoma, so that their in vivo expansion may have been driven by an exogenous antigen. Screening of a Melan-A cross-reactive peptide library suggested that these cells may be specific for an epitope derived from a Mycobacterium protein, which would provide a further example of CD8+ T cell cross-reactivity between a pathogen antigen and a tumor antigen. Finally, we discuss potential perspectives regarding the role of such cells in heterologous immunity, by influencing the balance between protective immunity and pathology, e.g. in the case of melanoma development

Comparison of sensitivity of Th1, Th2, and Th17 cells to Fas-mediated apoptosis

Following activation through the TCR, CD4+ T cells can differentiate into three major subsets: Th1, Th2, and Th17 cells. IL-17-secreting Th17 cells play an important role in the pathogenesis of several autoimmune diseases and in immune responses to pathogens, but little is known about the regulation of apoptosis in Th17 cells. In this study, the sensitivity of in vitro-polarized Th1, Th2, and Th17 cells to Fas-mediated apoptosis was compared directly by different methods. The order of sensitivity of T cell subsets to Fas-mediated apoptosis is: Th1 > Th17 > Th2. The greater sensitivity of Th17 cells to Fas-mediated apoptosis compared with Th2 cells correlated with their higher expression of FasL and comparable expression of the antiapoptotic molecule FLIP. The decreased sensitivity of Th17 compared with Th1 cells correlated with the higher expression of FLIP by Th17 cells. Transgenic overexpression of FLIP in T cells protected all three subsets from Fas-mediated apoptosis. These findings provide new knowledge for understanding how survival of different subsets of T cells is regulated