Proteomic Analysis of Growth Phase-Dependent Expression of Legionella pneumophila Proteins Which Involves Regulation of Bacterial Virulence Traits

Legionella pneumophila, which is a causative pathogen of Legionnaires' disease, expresses its virulent traits in response to growth conditions. In particular, it is known to become virulent at a post-exponential phase in vitro culture. In this study, we performed a proteomic analysis of differences in expression between the exponential phase and post-exponential phase to identify candidates associated with L. pneumophila virulence using 2-Dimentional Fluorescence Difference Gel Electrophoresis (2D-DIGE) combined with Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry (MALDI-TOF-MS). Of 68 identified proteins that significantly differed in expression between the two growth phases, 64 were up-regulated at a post-exponential phase. The up-regulated proteins included enzymes related to glycolysis, ketone body biogenesis and poly-3-hydroxybutyrate (PHB) biogenesis, suggesting that L. pneumophila may utilize sugars and lipids as energy sources, when amino acids become scarce. Proteins related to motility (flagella components and twitching motility-associated proteins) were also up-regulated, predicting that they enhance infectivity of the bacteria in host cells under certain conditions. Furthermore, 9 up-regulated proteins of unknown function were found. Two of them were identified as novel bacterial factors associated with hemolysis of sheep red blood cells (SRBCs). Another 2 were found to be translocated into macrophages via the Icm/Dot type IV secretion apparatus as effector candidates in a reporter assay with Bordetella pertussis adenylate cyclase. The study will be helpful for virulent analysis of L. pneumophila from the viewpoint of physiological or metabolic modulation dependent on growth phase

Exploring Pathways for Building Trust in Vaccination and Strengthening Health System Resilience

Background: Trust is critical to generate and maintain demand for vaccines in low and middle income countries. However, there is little documentation on how health system insufficiencies affect trust in vaccination and the process of re-building trust once it has been compromised. We reflect on how disruptions to immunizations systems can affect trust in vaccination and can compromise vaccine utilization. We then explore key pathways for overcoming system vulnerabilities in order to restore trust, to strengthen the resilience of health systems and communities, and to promote vaccine utilization. Methods: Utilizing secondary data and a review of the literature, we developed a causal loop diagram (CLD) to map the determinants of building trust in immunizations. Using the CLD, we devised three scenarios to illustrate common vulnerabilities that compromise trust and pathways to strengthen trust and utilization of vaccines, specifically looking at weak health systems, harmful communication channels, and role of social capital. Spill-over effects, interactions and other dynamics in the CLD were then examined to assess leverage points to counter these vulnerabilities. Results: Trust in vaccination arises from the interactions among experiences with the health system, the various forms of communication and social capital – both external and internal to communities. When experiencing system-wide shocks such as the case in Ebola-affected countries, distrust is reinforced by feedback between the health and immunization systems where distrust often lingers even after systems are restored and spills over beyond vaccination in the broader health system. Vaccine myths or anti-vaccine movements reinforce distrust. Social capital – the collective value of social networks of community members – plays a central role in increasing levels of trust. Conclusions: Trust is important, yet underexplored, in the context of vaccine utilization. Using a CLD to illustrate various scenarios helped to explore how common health and vaccine vulnerabilities can reinforce and spill over distrust through vicious, reinforcing feedback. Restoring trust requires a careful balance between eliminating vulnerabilities and strengthening social capital and interactions among communication channels

Cotton farmers’ willingness to pay for pest management services in northern Benin

This study was carried out to assess cotton farmers’ willingness to pay (WTP) for pest management services in northern Benin. Targeted staggered control (TSC) has been introduced to reduce pesticide use in cotton cropping and generate an estimated benefit of FCFA48,800 (€74.40) per cotton hectare accruing from increased productivity and reduced pesticide cost. However, TSC application requires extra time for pest identification and scouting, and its adoption remains low due to the lack of funding to boost farmers’ awareness and cover training costs. An interval regression model was used to analyze responses to a double-bounded contingent valuation survey with data collected from 300 cotton farmers. The results showed that 87.3% of cotton farmers were willing to pay for TSC services. Annual WTP per cotton hectare was estimated at FCFA16,962 (€25.80), revealing an existing demand for TSC adoption. Respondents' WTP was driven by farm and socio-economic characteristics. Financial mechanisms managed by farmers could thus potentially foster technology adoption, and in turn, generate economic and environmental benefits

Farm machinery use, off-farm employment and farm performance in China

We analyse the joint impacts of farm machinery use and off-farm employment on maize yields and agrochemical expenses from a household survey of 493 farmers in China. Our findings are obtained from an innovative two-stage econometric procedure that combines a bivariate ordered probit model with an endogeneity-corrected ordinary least square regression model. The results show that farmers are jointly making decisions to use farm machines and to work off the farm and that these two household activities affect maize yields and agrochemical expenses in different ways. We show that farm machinery use significantly increases both maize yields and agrochemical expenses, while off-farm employment significantly decreases agrochemical expenses. Our findings highlight the importance of additional machinery use in increasing farm production; the need to account for possible endogeneity in estimation; and the statistical significance of key household characteristics (gender, education, and household size) on overall farm production

Divergência entre genótipos de soja, cultivados em várzea irrigada

A divergência genética é um dos mais importantes parâmetros avaliados por melhoristas de plantas, na fase inicial de um programa de melhoramento genético. Diante disso, objetivou-se com este trabalho avaliar, por meio de técnicas multivariadas, a divergência genética entre 48 genótipos de soja, cultivados em várzea irrigada no Estado do Tocantins, com o intuito de identificar as combinações mais promissoras para produzir recombinações superiores, tanto destinados a produção de óleo e farelo, como do grupo especial, destinados ao consumo humano. O experimento foi conduzido no município de Formoso do Araguaia, TO, em cultivo de várzea irrigada na entressafra de 2010. O delineamento experimental foi o de blocos ao acaso, com quatro repetições. Verificou-se variabilidade entre os genótipos testados. Os resultados dos métodos de agrupamento de Tocher, UPGMA e Variáveis Canônicas foram concordantes entre si e detectaram quatro grupos distintos. As seguintes hibridações são promissoras para produção de grãos de soja destinados a óleo e farelo: M-Soy 8766, M-Soy 9144, A 7002 e M-Soy 9056 com Amaralina e cruzamentos entre M-Soy 8766, M-Soy 9144 e Amaralina com BRSMG 790A, BRS 257, BRS 216 e BRS 213 e são indicados visando a genótipos de soja especiais para alimentação humana