Project description:Since the emergence of the first cases in Wuhan, China, the novel coronavirus (2019-nCoV) infection has been quickly spreading out to other provinces and neighboring countries. Estimation of the basic reproduction number by means of mathematical modeling can be helpful for determining the potential and severity of an outbreak and providing critical information for identifying the type of disease interventions and intensity. A deterministic compartmental model was devised based on the clinical progression of the disease, epidemiological status of the individuals, and intervention measures. The estimations based on likelihood and model analysis show that the control reproduction number may be as high as 6.47 (95% CI 5.71–7.23). Sensitivity analyses show that interventions, such as intensive contact tracing followed by quarantine and isolation, can effectively reduce the control reproduction number and transmission risk, with the effect of travel restriction adopted by Wuhan on 2019-nCoV infection in Beijing being almost equivalent to increasing quarantine by a 100 thousand baseline value. It is essential to assess how the expensive, resource-intensive measures implemented by the Chinese authorities can contribute to the prevention and control of the 2019-nCoV infection, and how long they should be maintained. Under the most restrictive measures, the outbreak is expected to peak within two weeks (since 23 January 2020) with a significant low peak value. With travel restriction (no imported exposed individuals to Beijing), the number of infected individuals in seven days will decrease by 91.14% in Beijing, compared with the scenario of no travel restriction.
Project description:Plasmodium falciparum is a unicellular parasite responsible for the majority of 440,000 death due to malaria every year. Due to their essential role for malaria transmission, gametocytes represent prime targets for transmission-blocking strategies intended to prevent spread of the deadly disease. In this study, we explored the signaling pathways leading to gametogenesis and identified a hitherto unknown protein, which structurally belongs to the class of seven-helix proteins and which thus was termed 7-helix-1. The protein is specifically expressed in female gametocytes and gene disruption leads to impaired gamete formation and thus reduced transmission of malaria parasites to mosquitoes. The loss of 7-helix-1 caused significant changes in the expression of components of the molecular machinery needed by eukaryotic cells to synthesize proteins. We thus propose that 7-helix-1 is a key regulator needed to coordinate the increased need of proteins at the onset of gametogenesis.
Project description:Begomoviruses, the largest, most damaging and emerging group of plant viruses in the world, infect hundreds of plant species and new virus species of the group are discovered each year. They are transmitted by species of the whitefly Bemisia tabaci. Tomato yellow leaf curl virus (TYLCV) is one of the most devastating begomoviruses worldwide and causes major losses in tomato crops as well as in many more agriculturally important plant species. Different B. tabaci populations vary in their virus transmission abilities; the causes for these differences are attributed among others to genetic diversity of vector populations, as well as to differences in the bacterial symbiont flora of the insects. Here, we performed discovery proteomic analyses in nine whiteflies populations from both B (MEAM1) and Q (MED) species with different TYLCV transmission abilities. The results provide the first comprehensive list of candidate insect and bacterial symbiont (mainly Rickettsia) proteins associated with virus transmission. Efficient vector populations from two different B. tabaci species over-expressed or downregulated expression of proteins belonging to two different molecular pathways.
Project description:Analysis of a rabies cross-species transmission suggests a role for sub-viral populations in successful maintenance within new host reservoirs.
