957 resultados para Engineering, environmental


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Intracellular, vertically transmitted bacteria form complex and intimate relationships with their hosts. Wolbachia, maternally transmitted α- proteobacteria, live within the cells of numerous arthropod species. Wolbachia are famous master manipulators of insect reproduction: to favour their own spread they can induce male killing, parthenogenesis or cytoplasmic incompatibility. Wolbachia can also protect various insects from pathogens, which makes them a promising tool for the control of vector-borne diseases. Mosquitoes with Wolbachia have already been released in the wild to eliminate dengue. Yet, how Wolbachia manipulate their hosts remains largely unknown.(...)

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INTRODUCTION: The aim of the present study was to identify the presence of Leishmania (Leishmania) chagasi infection in dogs in the City of Palmas, Tocantins, Brazil, using the PCR technique to list the hot spots of infected dogs in the city and associate their occurrence to significant environmental changes at capture sites. METHODS: DNA was extracted from blood of dogs, and the PCR were performed with primers RV1/RV2. After screening the population studied, the regions of the city that had the highest occurrence of canine infection were detected. These sites were visited, and ecological parameters denoting anthropogenic disturbance were evaluated. RESULTS: Some important features were listed in the regions visited, such as low urbanization, lack of public collection of sewage, limited garbage collection, vacant lots with tall vegetation, decaying organic matter, and, most importantly, the occurrence of stray dogs and poultry in homes. CONCLUSIONS: The methodology for screening the population was very efficient, especially in evaluating a large number of individuals in a short time, with a high degree of automation. The results indicate an association between the observed parameters and the occurrence of infection in dogs. The model presented in the city is ideal for studies of disease progression and expansion and for the evaluation of control measures adopted for canine VL.

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INTRODUCTION: Vancomycin-resistant enterococci (VRE) can colonize or cause infections in high-risk patients and contaminate the environment. Our objective was to describe theepidemiological investigation of an outbreak of VRE, the interventions made, and their impact on its control. METHODS: We conducted a retrospective, descriptive, non-comparative study by reviewing the charts of patients with a VRE-positive culture in the University Hospital of Campinas State University, comprising 380 beds, 40 of which were in intensive care units (ICUs), who were admitted from February 2008-January 2009. Interventions were divided into educational activity, reviewing the workflow processes, engineering measures, and administrative procedures. RESULTS: There were 150 patients, 139 (92.7%) colonized and 11 (7.3%) infected. Seventy-three percent were cared for in non-ICUs (p = 0.028). Infection was more frequent in patients with a central-line (p = 0.043), mechanical ventilation (p = 0.013), urinary catheter (p = 0.049), or surgical drain (p = 0.049). Vancomycin, metronidazole, ciprofloxacin, and third-generation cephalosporin were previously used by 47 (31.3%), 31 (20.7%), 24 (16%), and 24 (16%) patients, respectively. Death was more frequent in infected (73%) than in colonized (17%) patients (p < 0.001). After the interventions, the attack rate fell from 1.49 to 0.33 (p < 0.001). CONCLUSIONS: Classical risk factors for VRE colonization or infection, e.g., being cared for in an ICU and previous use of vancomycin, were not found in this study. The conjunction of an educational program, strict adhesion to contact precautions, and reinforcement of environmental cleaning were able to prevent the dissemination of VRE.

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This paper demonstrates the significance of culture in examining the relationshipbetween democratic capital and environmental performance.The aim is to examine the relationship among scores on the Environmental Performance Index and the two dimensions of cross cultural variation suggested by Ronald Inglehart and Christian Welzel. Significantional interrelationships among democracy, cultural and environmental sustaintability measures could be found, following the regression results. Firstly, higher levels of democratic capital stock are associated with better environmental performance. Secondly importance to distinguish between cultural groups could be confirmed.

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INTRODUCTION: Leishmaniasis is an infectious and parasitic zoonotic, non-contagious, vector-borne disease caused by protozoa of the genus Leishmania. In Brazil, the major vector of Leishmania (Leishmania) infantum chagasi (Cunha & Chagas, 1934) is Lutzomyia longipalpis. Barra do Garças, State of Mato Grosso, was designated as a priority area by the Brazilian Ministry of Health for american visceral leishmaniasis, and it is important to identify the vector species present in this municipality. Our objective was to raise sandflies and study the influence of environmental variables on the vector density of Lutzomyia longipalpis. METHODS: We performed entomological monitoring in 3 districts using Centers for Disease Control and Prevention (CDC) light traps and recorded human cases of american visceral leishmaniasis in the city. We calculated the relative frequency and richness of sandflies and applied a transfer function model to the vector density correlate with relative humidity. RESULTS: The sandfly population was composed of 2 genera and 27 species, totaling 8,097 individuals. Monitoring identified Lutzomyia longipalpis (44%), followed by Lutzomyia lenti (18.9%), Lutzomyia whitmani (13.9%), Lutzomyia carmelinoi (9.1%), Lutzomyia evandroi (5.1%), Lutzomyia termitophila (3.3%), Lutzomyia sordellii (1.9%), and 20 other species (<4%). The male:female ratio was 3.5:1. We observed high species diversity (Dα = 6.65). Lutzomyia longipalpis showed occurrence peaks during the rainy season; there was a temporal correlation with humidity, but not with frequency or temperature. CONCLUSIONS: The presence of Lutzomyia longipalpis in the urban area of Barra do Garças underscores the changing disease profile, which was previously restricted to the wild environment.

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The growing demand for materials and devices with new functionalities led to the increased inter-est in the field of nanomaterials and nanotechnologies. Nanoparticles, not only present a reduced size as well as high reactivity, which allows the development of electronic and electrochemical devices with exclusive properties, when compared with thin films. This dissertation aims to explore the development of several nanostructured metal oxides by sol-vothermal synthesis and its application in different electrochemical devices. Within this broad theme, this study has a specific number of objectives: a) research of the influence of the synthesis parameters to the structure and morphology of the nanoparticles; b) improvement of the perfor-mance of the electrochromic devices with the application of the nanoparticles as electrode; c) application of the nanoparticles as probes to sensing devices; and d) production of solution-pro-cessed transistors with a nanostructured metal oxide semiconductor. Regarding the results, several conclusions can be exposed. Solvothermal synthesis shows to be a very versatile method to control the growth and morphology of the nanoparticles. The electrochromic device performance is influenced by the different structures and morphologies of WO3 nanoparticles, mainly due to the surface area and conductivity of the materials. The dep-osition of the electrochromic layer by inkjet printing allows the patterning of the electrodes without wasting material and without any additional steps. Nanostructured WO3 probes were produced by electrodeposition and drop casting and applied as pH sensor and biosensor, respectively. The good performance and sensitivity of the devices is explained by the high number of electrochemical reactions occurring at the surface of the na-noparticles. GIZO nanoparticles were deposited by spin coating and used in electrolyte-gated transistors, which promotes a good interface between the semiconductor and the dielectric. The produced transistors work at low potential and with improved ON-OFF current ratio, up to 6 orders of mag-nitude. To summarize, the low temperatures used in the production of the devices are compatible with flexible substrates and additionally, the low cost of the techniques involved can be adapted for disposable devices.

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Double degree

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Double degree

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Introduction The incidence of opportunistic fungal infections has increased in recent years and is considered an important public health problem. Among systemic and opportunistic mycoses, cryptococcosis is distinguished by its clinical importance due to the increased risk of infection in individuals infected by human immunodeficiency virus. Methods To determine the occurrence of pathogenic Cryptococcus in pigeon excrement in the City of Araraquara, samples were collected from nine environments, including state and municipal schools, abandoned buildings, parks, and a hospital. The isolates were identified using classical tests, and susceptibility testing for the antifungal drugs (fluconazole, itraconazole, voriconazole, and amphotericin B) independently was also performed. After collection, the excrement samples were plated on Niger agar and incubated at room temperature. Results A total of 87 bird dropping samples were collected, and 66.6% were positive for the genus Cryptococcus. The following species were identified: Cryptococcus neoformans (17.2%), Cryptococcus gattii (5.2%), Cryptococcus ater (3.5%), Cryptococcus laurentti (1.7%), and Cryptococcus luteolus (1.7%). A total of 70.7% of the isolates were not identified to the species level and are referred to as Cryptococcus spp. throughout the manuscript. Conclusions Although none of the isolates demonstrated resistance to antifungal drugs, the identification of infested areas, the proper control of birds, and the disinfection of these environments are essential for the epidemiological control of cryptococcosis.

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The history between cetaceans and humans is documented throughout time not only in reports, descriptions, and tales but also in legal documents, laws and regulations, and tithes. This wealth of information comes from the easy spotting and identification of individuals due to their large size, surface breathing, and conspicuous above water behaviour. This work is based on historical sources and accounts accounting for cetacean presence for the period between the 12th and 17th centuries, as well as scientific articles, newspapers, illustrations, maps, non-published scientific reports, and other grey literature from the 18th century onwards. Information on whale use in Portugal's mainland has been found since as early as the 12th century and has continued to be created throughout time. No certainty can be given for medieval and earlier events, but both scavenging of stranded whales or use of captured ones may have happened. There is an increasing number of accounts of sighted, stranded, used, or captured cetaceans throughout centuries which is clearly associated with a growing effort towards the study of these animals. Scientific Latin species denominations only started to be registered from the 18th century onwards, as a consequence of the evolution of natural sciences in Portugal and increasing interest from zoologists. After the 19th century, a larger number of observations were recorded, and from the 20th century to the present day, regular scientific records have been collected. Research on the environmental history of cetaceans in Portugal shows a several-centuries-old exploitation of whales and dolphins, as resources mainly for human consumption, followed in later centuries by descriptions of natural history documenting strandings and at sea encounters. Most cetaceans species currently thought to be present in Portuguese mainland waters were at some point historically recorded.

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Introduction Visceral leishmaniasis (VL) stands out as a zoonosis observed on four continents and also in urban expansion zones in several regions of Brazil. Methods A cross-sectional epidemiological study of VL cases in children under 15 years of age in the period from 2007 to 2012. Clinical data were gathered from medical reports; meteorological data were obtained at the Meteorological Measurement Department of UFT. Environmental variables were divided into two periods, rainy and dry. Results The study revealed no difference by gender (p=0.67) among the 821 patients. However, the most affected age group was between one and five years of age (58.6%; p<0.01); the highest prevalence of the disease (99.03%; p<0.01) occurred in urban zones; and the most affected ethnic group (85.5%; p<0.01) was mixed race. The highest incidence coefficients in this population occurred in 2007 and 2008 (578.39/100,000 inhabitants; 18.5/100,000 inhabitants, respectively), whereas the highest lethality coefficients occurred in 2008 and 2011 (0.85/100 deaths). There was no significant correlation between average rainfall and the number of VL cases. The correlation between temperature and number of VL cases was negative (r = -0.4039; p<0.01). Conclusions In Araguaína, visceral leishmaniasis in children under 15 years is an urban-based endemic disease distributed across all districts of the city wherein temperature as an environmental factor, a higher prevalence in mixed race children between one and five years of age, and a high incidence coefficient all strongly contribute to child mortality.

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ABSTRACT INTRODUCTION: Emergent and re-emergent waterborne protozoans have become a worldwide public health problem, especially among vulnerable groups. METHODS: This cross-sectional study evaluated 17 HIV-infected children and their families. RESULTS: A high (76.5%) percentage of parasite-infected children was observed, even among children with CD4+ T-cell counts of >200 cells/mm3. Giardia spp., Cryptosporidium spp. and Cyclospora spp. were observed in 41.2% of these children Low income, poor hygiene practices, and co-infection in domestic, peridomestic and scholastic environments were significant sources of these intestinal infections. CONCLUSIONS: Early diagnosis, timely treatment, and socio-educational interventions may improve the health conditions of this vulnerable population.