Comparative analysis of TMV-Cg and TMV-U1 detection methods in infected Arabidopsis thaliana.

The common strain of the tobacco mosaic virus (TMV-U1), and the crucifer-infecting tobacco mosaic virus (TMV-Cg), both members of Tobamovirus genus, infect efficiently the solanaceous plants such as tomato and tobacco. The crucifer-infecting tobacco mosaic virus (TMV-Cg) also infects Arabidopsis thaliana plant, spreading systemically without causing severe symptoms. In contrast, Arabidopsis is a poor host for TMV-U1 infection. Within the past 10 years, Arabidopsis has developed into a powerful model system for studying plant-pathogen interaction. However, a detailed analysis comparing the accuracy of various viral detection methods has not been reported previously. Four detection methods were evaluated in A. thaliana (ecotype Po-1), infected with TMV-U1 or TMV-Cg. Western blots, enzyme-linked immunosorbent assay (ELISA), reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ RNA hybridization methods were used to determine viral spread at various days post inoculation (dpi) in inoculated and apical non-inoculated leaves. The detection of viral spread of TMV-U1 and TMV-Cg in Arabidopsis, using these four detection methods, supports previous studies, which demonstrate that the systemic spreads of these two viruses differ in Arabidopsis. Western blotting and ELISA detected TMV-Cg at 5dpi, and TMV-U1 at 12 dpi in systemic tissues. Viral spread was detected earlier when using RNA detection methods. Reverse transcriptase-polymerase chain reaction (RT-PCR) was very sensitive for detecting TMV-Cg in A. thaliana, but less sensitive for TMV-U1 detection. In situ RNA hybridization showed differential distribution of TMV-Cg and TMV-U1 in the inoculated leaf and systemic tissues.

[Differential mortality in women of reproductive age]. / La mortalidad diferencial de las mujeres en edades reproductivas.

"This paper begins by reviewing some conceptual frameworks for the study of female mortality and indicates some of its application problems. Next it presents results of mortality of women in reproductive-age classified by age, causes of death, and socio-demographic traits (marital status, schooling, and occupation) for ten states [in Mexico] differentiated according to level of development and well-being. The data suggests differences according to age, marital status, and schooling. Finally, testing of the mutual independence and partial independence hypotheses indicates that age, marital status, and schooling correlate to the degree of development of each state." (SUMMARY IN ENG)