3,144 research outputs found

    Artemisinin-based combination therapy does not measurably reduce human infectiousness to vectors in a setting of intense malaria transmission

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    <p>Background: Artemisinin-based combination therapy (ACT) for treating malaria has activity against immature gametocytes. In theory, this property may complement the effect of terminating otherwise lengthy malaria infections and reducing the parasite reservoir in the human population that can infect vector mosquitoes. However, this has never been verified at a population level in a setting with intense transmission, where chronically infectious asymptomatic carriers are common and cured patients are rapidly and repeatedly re-infected.</p> <p>Methods: From 2001 to 2004, malaria vector densities were monitored using light traps in three Tanzanian districts. Mosquitoes were dissected to determine parous and oocyst rates. Plasmodium falciparum sporozoite rates were determined by ELISA. Sulphadoxinepyrimethamine(SP) monotherapy was used for treatment of uncomplicated malaria in the contiguous districts of Kilombero and Ulanga throughout this period. In Rufiji district, the standard drug was changed to artesunate co-administered with SP (AS + SP) in March 2003. The effects of this change in case management on malaria parasite infection in the vectors were analysed.</p> <p>Results: Plasmodium falciparum entomological inoculation rates exceeded 300 infective bites per person per year at both sites over the whole period. The introduction of AS + SP in Rufiji was associated with increased oocyst prevalence (OR [95%CI] = 3.9 [2.9-5.3], p < 0.001), but had no consistent effect on sporozoite prevalence (OR [95%CI] = 0.9 [0.7-1.2], p = 0.5). The estimated infectiousness of the human population in Rufiji was very low prior to the change in drug policy. Emergence rates and parous rates of the vectors varied substantially throughout the study period, which affected estimates of infectiousness. The latter consequently cannot be explained by the change in drug policy.</p> <p>Conclusions: In high perennial transmission settings, only a small proportion of infections in humans are symptomatic or treated, so case management with ACT may have little impact on overall infectiousness of the human population. Variations in infection levels in vectors largely depend on the age distribution of the mosquito population. Benefits of ACT in suppressingtransmission are more likely to be evident where transmission is already low or effective vector control is widely implemented.</p&gt

    System Approaches for the Analysis of Water Quality Management of the Sio, Kapos, Veszpremi-Sed, Malom, Nador, and Gaja River System (Hungary)

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    The current challenge for water quality management in Central Europe and Eastern Europe is to identify feasible and cost-effective strategies for achieving sustainable progress towards improved water quality. This goal is set against a background of existing water quality standards which are strong but difficult to enforce, the changing role of the public sector after the fall of central planning, limited financial resources and the uncertainty and weak economic conditions of the transition. Within this context, successful water quality management requires strategies that are: (a) administratively enforceable; (b) strengthen and stabilize water quality management institutions; (c) financially feasible; (d) promote economic efficiency; and (e) fairly distribute costs over responsible parties. The Sio, Kapos, Veszpremi-Sed, Malom, Nador and Gaja River System epitomizes this need and confronts nearly all of the serious water management problems now facing Hungary. It is the home to the majority of Hungary's chemical industries receiving high wastewater loads from both industrial and municipal sources. The government seeks to clean up the river system, especially the Veszpremi-Sed River and Malom and Nador Channels, but is concerned about the costs of the chemical industry and the economically stressed municipalities and their customers. Local water and environmental authorities face the controversial challenge of satisfying the various demands on the system while taking into account constraints on both quality and supply. In this microcosm of Hungary and Central and Eastern Europe a water quality modeling and management tool developed by IIASA's Water Resources Project will be applied to help identify effective water quality management alternatives. This introductory Working Paper describes the nature of the water quality management problem, the policy setting and the management strategies which will be assessed

    What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

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    Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

    Serological responses in dairy calves to various vaccines administered via needle-free or conventional needle-based injections

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    One hundred and four, 5- to 10-month-old Holstein heifers and steers were blocked by age within gender and randomly assigned to treatments. Calves were vaccinated with 5- way modified-live respiratory viral vaccine, Mannheimia hemolytic bacterin/toxoid, and 5- way Leptospira bacterin, administered via either needle-free or conventional needle-andsyringe injection techniques. Blood samples were collected from all calves at the time of vaccination and 21 days later. Blood sera were analyzed for antibody titers to infectious bovine rhinotracheitis (IBR) virus as the indicator of serological response to the 5-way viral vaccine, to Leptospira pomona (LP) as the indicator of serological response to the 5-way Leptospira bacterin, and to Mannheimia hemolytica (MH) leukotoxoid. Responses of heifers on day 21 to the IBR fraction of the 5-way viral vaccine, MH bacterin, and LP fraction of the 5-way Lepto bacterin did not differ between methods of administration. Responses of steers on day 21 to the IBR fraction of the 5-way viral vaccine and MH bacterin were greater for the needle-free method of administration, whereas serological response to the LP fraction did not differ between methods of administration. We conclude that needle-free injections can eliminate broken needles in the carcass, reduce needle-borne transmission of disease, and possibly produce greater serological responses to various antigens, compared with those obtained with conventional needle-and-syringe injection systems.; Dairy Day, 2005, Kansas State University, Manhattan, KS, 2005; Dairy Research, 2005 is known as Dairy Day, 200

    Serological responses to IBR viral vaccine and Mannheimia haemolytica bacterin/leukotoxoid administered with needle-free injection technology

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    Yearling steers were randomized to treatment and vaccinated with 5-way modified live viral vaccine and Mannheimia haemolytica bacterin/toxoid by using either needle-free or standard needle injection. Blood samples were collected from all animals at the time of vaccination and 21 days later, and the serum was analyzed for antibody titers to infectious bovine rhinotracheitis (IBR) virus and M. haemolytica leukotoxoid. Serological responses to the IBR viral fraction of the 5-way viral vaccine were significantly greater on day 21 after administration with the needle-free injection system. Serological responses to the M. haemolytica leukotoxoid tended to be greater on day 21 after administration with the needle-free injection system

    The 2dF QSO Redshift Survey - XII. The spectroscopic catalogue and luminosity function

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    We present the final catalogue of the 2dF QSO Redshift Survey (2QZ), based on Anglo-Australian Telescope 2dF spectroscopic observations of 44 576 colour-selected (ubJr) objects with 18.2

    Key lessons from the COVID-19 public health response in Australia

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    Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts. Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decision-making that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a ‘standing threat’, 10) regional and global solidarity is important. It should be acknowledged that we were unable to capture all relevant nuances and context specific differences. However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region

    Quantum wave equation of photon

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    In this paper, we give the quantum wave equations of single photon when it is in the free or medium space. With these equations, we can study light interference and diffraction with quantum approach. Otherwise, they can be applied in quantum optics and photonic crystal.Comment: 8 pages, 0 figure
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