A role for systems epidemiology in tuberculosis research

Despite being a curable disease, tuberculosis (TB) killed more people in 2009 than during any previous year in history. Progress in TB research has been slow, and remains burdened by important gaps in our knowledge of the basic biology of Mycobacterium tuberculosis, the causative agent of TB, and its interaction with the human host. Fortunately, major systems biology initiatives have recently been launched that will help fill some of these gaps. However, to fully comprehend TB and control this disease globally, current systems biological approaches will not suffice. The influence of host and pathogen diversity, changes in human demography, and socioeconomic and environmental factors will also need to be considered. Such a multidisciplinary approach might be best described as 'systems epidemiology' in an effort to overcome the traditional boundaries between basic biology and classical epidemiolog

Impact of an invasive alga (Womersleyella setacea) on sponge assemblages: compromising the viability of future populations

10 páginas, 5 figuras, 1 tabla.The effects of invasive species on native fauna are understudied, even though their consequences should be taken into consideration for the proper conservation and management of marine systems. Furthermore, bioinvasions may have greater consequences if they affect key structural species with slow dynamics such as marine sponges. We propose that reproductive output could be used as a potential early warning signal to detect possible future changes in population trends of long-lived species (i.e. sponges) as a result of biological invasions. The aim of this study was to investigate the effects of invasive algal (Womersleyella setacea) overgrowth on sponge reproduction by comparing the presence of reproductive elements (spermatic cysts, oocytes, embryos, and larvae) in sponges covered by a thick carpet of the invasive algae and in sponges dwelling in the same habitat but without the invasive algae. Three variables were calculated to assess the impact of the invasive alga on sponge reproduction: the reproductive effort, the proportion of individuals in reproduction, and the size of the reproductive structures. We studied eight sponge species representing the main components of the deep rocky reefs of the area. Our results showed that W. setacea had a strong negative effect on sponge reproduction in six out of eight sponge species studied, with lower and even nil reproductive structures on the sponges subjected to the algal overgrowth. Thus, considering that sexual reproduction is necessary for the persistence of most sponge populations, a significant and constant reduction of the reproductive effort may compromise their viability and affect future trends in these benthic systems.Financial support was provided by an EU reintegration grant (ERG-2009-248252) and the project Tracking Changes in the Marine benthos by Novel Molecular Tools: Individuals, populations, communities (BENTHOMICS) from the Ministerio de Ciencia e Innovacio ´n of the Spanish Government (MICINN) (CTM2010- 22218-C02). SC and EC were funded by a Juan de la Cierva Postdoctoral Fellowship.Peer reviewe