Blood meal sources of wild and domestic Triatoma infestans (Hemiptera : Reduviidae) in Bolivia : connectivity between cycles of transmission of Trypanosoma cruzi

Background: Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. Methods: In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Results and discussion: Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36 %) and Galea musteloides (30 %), while humans were the third most prevalent source (18.7 %). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. Conclusion: The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans

Teleworking practice in small and medium-sized firms: Management style and worker autonomy

In an empirical study of teleworking practices amongst small and medium-sized enterprises (SMEs) in West London, organisational factors such as management attitudes, worker autonomy and employment flexibility were found to be more critical than technological provision in facilitating successful implementation. Consequently, we argue that telework in most SMEs appears as a marginal activity performed mainly by managers and specialist mobile workers

Individual Preferences and Social Interactions Determine the Aggregation of Woodlice

n°e17389.info:eu-repo/semantics/publishe

A knowledge management platform for the promotion of modern rural energy services in ASEAN countries

Modern Rural Energy Service (MRES) has been developed and implemented for years. It offers lots of advantage such as efficient energy and clean environment. However, MRES is used only in a particular group due to the lack of knowledge and promotion. This paper proposes the design and development of a Knowledge Management platform for promotion of MRES in ASEAN countries. The proposed system will employ web service technologies for enhancing and distribution the utilization of MRES

What affect student cognitive style in the development of hypermedia learning system?

Recent developments in learning technology such as hypermedia is becoming widespread and offer significant contribution to improve the delivery of learning and teaching materials. A key factor in the development of hypermedia learning system is cognitive style (CS) as it relates to users' information processing habits, representing individual user's typical modes of perceiving, thinking, remembering and problem solving. The sample comprised of 217 students from Murdoch University who were enrolled in a first-year undergraduate unit. A survey was carried out every second semester over a period of 3 years (1999-2001). Both generalized linear model and tree-based regression were used to analyse the interaction among the learning dimensions and the effect on students' CS. When comparing both models, tree-based regression outperformed generalized linear model in this study. The research findings indicated that non-linear learning is the primary dimension that determines students' CS. This is subsequently, followed by multiple tools (MT) and learner control (LC) dimensions. The results also confirm that background information has effects on students' CS. The overall findings suggest that students' preference of learning dimensions such as linear vs. non-linear, level of LC and the range of MT must be taken into consideration in order to enrich students' quality of education by means of motivating students' acquisition of subject matter through individualize instruction when designing, developing, and delivering educational resources

Static and dynamic difficulty level design for edutainment game using artificial neural networks

When designing a game, one of the major tasks is to design a game of exciting and challenging difficulty levels to maintain the interest level of a player throughout the game. This is especially important when designing an educational game. This paper proposes the use of Artificial Neural Networks (ANNs), specifically the Backpropagation Neural Networks (BPNNs) for handling the gaming experience. The BPNNs can provide targeted learning experience for the user or the student. This will achieve personalized learning that is an important issue for student relationship management. The proposed frameworks will provide motivation for the student as the difficulty level progresses and adjusts to suit individual users

INFLUENCE of ASYMPTOMATIC PEOPLE on MALARIA TRANSMISSION: A MATHEMATICAL MODEL for A LOW-TRANSMISSION AREA CASE

Malaria remains a primary parasitic disease in the tropical world, generating high morbidity and mortality in human populations. Recently, community surveys showed a high proportion of asymptomatic cases, which are characterized by a low parasitemia and a lack of malaria symptoms. Until now, the asymptomatic population is not treated for malaria and thus remains infective for a long time. In this paper, we introduce a four-dimensional mathematical model to study the influence of asymptomatic people on malaria transmission in low-transmission areas, specifically using data from Brazil. The equilibrium points of the system are calculated, and their stability is analyzed. Via numerical simulations, more in-depth analyzes of the space of some crucial parameters on the asymptomatic population are done, such as the per capita recovery rates of symptomatic and asymptomatic people, the ratio of the density of mosquitoes to that of humans, the mortality rate of mosquitoes and the probability of undergoing asymptomatic infection upon an infectious mosquito bite. Our results indicate that the disease-free equilibrium is inside the stability region if asymptomatic people are treated and/or the ratio of the density of mosquitoes to that of humans is decreased and/or the mortality rate of mosquitoes is increased