252 research outputs found
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Advanced Modeling of Renewable Energy Market Dynamics: May 2006
This report documents a year-long academic project, presenting selected techniques for analysis of market growth, penetration, and forecasting applicable to renewable energy technologies. Existing mathematical models were modified to incorporate the effects of fiscal policies and were evaluated using available data. The modifications were made based on research and classification of current mathematical models used for predicting market penetration. An analysis of the results was carried out, based on available data. MATLAB versions of existing and new models were developed for research and policy analysis
Soil organisms in organic and conventional cropping systems.
Apesar do crescente interesse pela agricultura orgânica, sĂŁo poucas as informações de pesquisa disponĂveis sobre o assunto. Assim, num Argissolo Vermelho-Amarelo distrĂłfico foram comparados os efeitos de sistemas de cultivo orgânico e convencional, para as culturas do tomate (Lycopersicum esculentum) e do milho (Zea mays), sobre a comunidade de organismos do solo e suas atividades. As populações de fungos,bactĂ©rias e actinomicetos, determinadas pela contagem de colĂ´nias em meio de cultura, foram semelhantes para os dois sistemas de produção. A atividade microbiana, avaliada pela evolução de CO2, manteve-se superior no sistema orgânico, sendo que em determinadas avaliações foi o dobro da evolução verificada no sistema convencional. O nĂşmero de espĂ©cimes de minhoca foi praticamente dez vezes maior no sistema orgânico. NĂŁo foi observada diferença na taxa de decomposição de matĂ©ria orgânica entre os dois sistemas. De modo geral, o nĂşmero de indivĂduos de microartrĂłpodos foi superior no sistema orgânico do que no sistema convencional, refletindo no maior Ăndice de diversidade de Shannon. As maiores populações de insetos foram as da ordem Collembola, enquanto para os ácaros a maior população foi a da superfamĂlia Oribatuloidea. IndivĂduos dos grupos Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura e Symphyla foram ocasionalmente coletados e de forma similar entre os sistemas
Osteoporosis-related life habits and knowledge about osteoporosis among women in El Salvador: A cross-sectional study
BACKGROUND: Osteoporosis is a systemic skeletal disorder, characterized by reduced bone mass, deterioration of bone structure, increased bone fragility, and increased fracture risk. It is more frequent to find among women than men at a 4:1 ratio. Evidence suggests that to adopt changes on some life habits can prevent or delay development of osteoporosis. Several osteoporosis-risk factors have been confirmed in the US and western Europe, but in El Salvador there are neither reliable epidemiological statistics about this skeletal disorder nor studies addressing osteoporosis-risk factors in women. The aim of this study was to determinate the extent of osteoporosis knowledge, the levels of both daily calcium intake and weight-bearing physical activity, and the influence of several osteoporosis-risk factors on these variables in three age groups of Salvadorean women. METHODS: In this exploratory cross-sectional study, an osteoporosis knowledge assessment questionnaire incluiding a food frequency and a physical activity record section were used to collect data and it was delivered through a face-to-face interview. A convenience sample (n = 197) comprised of three groups of women aged 25–35 years, 36–49 years, and over 49 years was taken. Among-group comparisons of means were analyzed by two-way ANOVA. To determinate the overall influence of osteoporosis-risk factors, the multivariate analysis was used. RESULTS: Study results indicated that better educated women had more knowledge about osteoporosis than women with a low education level, regardless of age, even though this knowledge was rather fair. Older women got more weight-bearing physical activity at home and less at place of employment than reported by the younger women; however, neither group performed sufficient high-intensity WBPA to improve bone mass. Regardless of age, the most women consumed 60% or less than the Dietary Reference Intake of calcium and depend on household income, lactose intolerance and coffee rather than milk consumption. CONCLUSION: In summary, the majority of women in this study have modest knowledge on osteoporosis. The knowledge base is not linked to preventive health habits, including sufficient calcium intake and performance of weight-bearing physical activities. They are thus at increased risk for low bone mass
Unmet need for contraception among sex workers in Madagascar
The study was conducted to investigate past and future pregnancy preferences and contraceptive need among Malagasy sex workers
BARRIERS TO THE USE OF MODERN CONTRACEPTIVES AND IMPLICATIONS FOR WOMAN-CONTROLLED PREVENTION OF SEXUALLY TRANSMITTED INFECTIONS IN MADAGASCAR
Globally, unplanned pregnancies and sexually transmitted infections (STIs) persist as significant threats to women’s reproductive health. Barriers to the use of modern contraceptives by women might inhibit uptake of novel woman-controlled methods for preventing STIs/HIV. Use of modern contraceptives and perceptions and attitudes towards contraceptive use were investigated among women in Antananarivo, Madagascar using qualitative research. The hypothetical acceptability of the diaphragm, a woman-controlled barrier contraceptive device that also holds promise of protecting against STI/HIV, was assessed. Women consecutively seeking care for vaginal discharge at a public health clinic were recruited for participation in a semi-structured interview (SSI) or focus group discussion (FGD). Audiotaped SSIs and FGDs were transcribed, translated, and coded for predetermined and emerging themes. Of 46 participating women, 70% reported occasional use of male condoms, mostly for preventing pregnancy during their fertile days. Although women could name effective contraceptive methods, only 14% reported using hormonal contraception. Three barriers to use of modern contraceptives emerged: gaps in knowledge about the range of available contraceptive methods; misinformation and negative perceptions about some methods; and concern about social opposition to contraceptive use, mainly from male partners. These results demonstrate the need for programs in both family planning and STI prevention to improve women’s knowledge of modern contraceptives and methods to prevent STI and to dispel misinformation and negative perceptions of methods. In addition, involvement of men will likely be a critical component of increased uptake of woman-controlled pregnancy and STI/HIV prevention methods and improved health
Quantification of within- and between-farm dispersal of Culicoides biting midges using an immunomarking technique.
Culicoides biting midges (Diptera, Ceratopogonidae) are vectors of arboviruses that cause significant economic and welfare impact. Local-scale spread of Culicoides-borne arboviruses is largely determined by the between-farm movement of infected Culicoides.Study of the dispersal behaviour of Culicoides by capture-mark-recapture (CMR) is problematic due to the likelihood of mortality and changes in behaviour upon capture caused by the small size and fragility of these insects, evidenced by low recapture rates. To counter the problem of using CMR with Culicoides, this study utilised an ovalbumin immunomarking technique to quantify the within- and between-farm dispersal of Culicoides in southern England.Both within- and between-farm dispersal of Culicoides was observed. Of the 9058 Culicoides collected over 22 nights of trapping, 600 ovalbumin-positive Culicoides, of 12 species including those implicated as arbovirus vectors, were collected with a maximum dispersal distance of 3125 m.This study provides the first species-level data on the between-farm dispersal of potential bluetongue, Schmallenberg and African horse sickness virus vectors in northern Europe. High-resolution meteorological data determined upwind and downwind flight by Culicoides had occurred. Cumulative collection and meteorological data suggest 15·6% of flights over 1 km were upwind of the treatment area and 84·4% downwind. Synthesis and applications. The use of immunomarking eliminates the potential adverse effects on survival and behaviour of insect collection prior to marking, substantially improving the resolution and accuracy of estimates of the dispersal potential of small and delicate vector species such as Culicoides. Using this technique, quantification of the range of Culicoides dispersal with regard to meteorological conditions including wind direction will enable improved, data-driven modelling of the spread of Culicoides-borne arboviruses and will inform policy response to incursions and outbreaks
Sleep deprivation impairs and caffeine enhances my performance, but not always our performance: how acting in a group can change the effects of impairments and enhancements
What effects do factors that impair or enhance performance in individuals have when these individuals act in groups? We provide a framework, called the GIE ("Effects of Grouping on Impairments and Enhancements”) framework, for investigating this question. As prominent examples for individual-level impairments and enhancements, we discuss sleep deprivation and caffeine. Based on previous research, we derive hypotheses on how they influence performance in groups, specifically process gains and losses in motivation, individual capability, and coordination. We conclude that the effect an impairment or enhancement has on individual-level performance is not necessarily mirrored in group performance: grouping can help or hurt. We provide recommendations on how to estimate empirically the effects individual-level performance impairments and enhancements have in groups. By comparing sleep deprivation to stress and caffeine to pharmacological cognitive enhancement, we illustrate that we cannot readily generalize from group results on one impairment or enhancement to another, even if they have similar effects on individual-level performance
Enzyme Sequence and Its Relationship to Hyperbaric Stability of Artificial and Natural Fish Lactate Dehydrogenases
The cDNAs of lactate dehydrogenase b (LDH-b) from both deep-sea and shallow living fish species, Corphaenoides armatus and Gadus morhua respectively, have been isolated, sequenced and their encoded products overproduced as recombinant enzymes in E. coli. The proteins were characterised in terms of their kinetic and physical properties and their ability to withstand high pressures. Although the two proteins are very similar in terms of their primary structure, only 21 differences at the amino acid level exist between them, the enzyme from the deep-sea species has a significantly increased tolerance to pressure and a higher thermostability. It was possible to investigate whether the changes in the N-terminal or C-terminal regions played a greater role in barophilic adaptation by the construction of two chimeric enzymes by use of a common restriction site within the cDNAs. One of these hybrids was found to have even greater pressure stability than the recombinant enzyme from the deep-living fish species. It was possible to conclude that the major adaptive changes to pressure tolerance must be located in the N-terminal region of the protein. The types of changes that are found and their spatial location within the protein structure are discussed. An analysis of the kinetic parameters of the enzymes suggests that there is clearly a trade off between Km and kcat values, which likely reflects the necessity of the deep-sea enzyme to operate at low temperatures
Vaginal microbicide and diaphragm use for sexually transmitted infection prevention: A randomized acceptability and feasibility study among high-risk women in Madagascar (Sex Transm Dis (2008) 35(9) 818-26)
In preparation for a randomized controlled trial (RCT), we conducted a pilot RCT of the acceptability and feasibility of diaphragms and candidate vaginal microbicide for sexually transmitted infection prevention among high-risk women in Madagascar
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