978 resultados para Presence-only data


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This paper describes the TURTLE project that aim to develop sub-systems with the capability of deep-sea long-term presence. Our motivation is to produce new robotic ascend and descend energy efficient technologies to be incorporated in robotic vehicles used by civil and military stakeholders for underwater operations. TURTLE contribute to the sustainable presence and operations in the sea bottom. Long term presence on sea bottom, increased awareness and operation capabilities in underwater sea and in particular on benthic deeps can only be achieved through the use of advanced technologies, leading to automation of operation, reducing operational costs and increasing efficiency of human activity.

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During a health survey in a primary school from the district of Carabayllo (North of Lima, Peru), 200 schoolchildren (96 male and 104 female between five to 12 years old) were randomly selected and divided in two groups (as positive or negative group), according to the serologic result of the Toxocara ELISA test from a total population of 646 schoolchildren. All children were analyzed by hematologic tests to determinate the frequency of eosinophilia and leukocytosis. Additionally, all clinical and epidemiological data were also analyzed to determine their association with toxocariasis. From group of children with positive serology, 40% had some type of eosinophilia in contrast to 19% of children with negative serology, and their association was statistically significant (OR = 2.84, p < 0.001). From all signs and symptoms evaluated, only 'dry cough' was more frequent and statistically significant in the positive serology group (OR = 2.79, p < 0.001). Almost all risk factors evaluated were highly frequent and statistically associated to the positive serology. In conclusion, the presence of eosinophilia and the risk factors evaluated in this population were frequently associated to human toxocariasis.

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Epidemiological studies conducted in Peru disclosed HTLV-1 to be prevalent in different ethnic groups, and found HTLV-2 in some Amazonian Indians and in men who have sex with men. No data concerning HTLV-1/2 infection in blood donors from Arequipa, a highlands region in southern Peru, is available. We searched for the presence of HTLV-1 and HTLV-2 antibodies in 2,732 serum samples obtained from blood donors from this geographic area. HTLV-1/2-specific antibodies were detected using an enzyme-linked immunosorbent assay (ELISA) and were confirmed by Western blot (WB). Reactive sera had their blood bags discarded from donation, and the demographic characteristics of the donors were analyzed. Thirty-five sera (1.2%) were HTLV seroreactive by ELISA, and 25 were confirmed HTLV-1-positive by WB. One serum disclosed HTLV-positivity, and the remaining nine serum samples showed indeterminate results by WB; three of which had an HTLV-1 indeterminate Gag profile. The median age of HTLV-positive individuals was 34.6 years; 27 were male and eight were female. All individuals were from southern Peru: 27 from Arequipa, five from Puno, and three from Cuzco. HTLV co-positivity with hepatitis B (five sera) and syphilis (one serum) were detected. Previous transfusion and tattooing were observed in two and one individuals, respectively. No serum was positive for HTLV/HIV co-infection. This study confirmed, for the first time, HTLV-1 infection and the absence of HTLV-2 infection in blood donors from Arequipa, Peru and suggests vertical transmission as the major route of HTLV-1 transmission and acquisition in this geographic region.

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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

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Hepatitis C virus (HCV) and human T-cell lymphotropic virus type 1 (HTLV-1) share routes of transmission and some individuals have dual infection. Although some studies point to a worse prognosis of hepatitis C virus in patients co-infected with HTLV-1, the interaction between these two infections is poorly understood. This study evaluated the influence of HTLV-1 infection on laboratory parameters in chronic HCV patients. Twelve HTLV-1/HCV-coinfected patients were compared to 23 patients infected only with HCV, in regard to demographic data, risk factors for viral acquisition, HCV genotype, presence of cirrhosis, T CD4+ and CD8+ cell counts and liver function tests. There was no difference in regard to age, gender, alcohol consumption, smoking habits, HCV genotype or presence of cirrhosis between the groups. Intravenous drug use was the most common risk factor among individuals co-infected with HTLV-1. These patients showed higher TCD8+ counts (p = 0.0159) and significantly lower median values of AST and ALT (p = 0.0437 and 0.0159, respectively). In conclusion, we have shown that HCV/HTLV-1 co-infected patients differs in laboratorial parameters involving both liver and immunological patterns. The meaning of these interactions in the natural history of these infections is a matter that deserves further studies.

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At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

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OBJECTIVE: To evaluate the prevalence of the urinary excretion of BKV and JCV in HIV-infected patients without neurological symptoms. METHODS: Urine samples from HIV-infected patients without neurological symptoms were tested for JC virus and BK virus by PCR. Samples were screened for the presence of polyomavirus with sets of primers complementary to the early region of JCV and BKV genome (AgT). The presence of JC virus or BK virus were confirmed by two other PCR assays using sets of primers complementary to the VP1 gene of each virus. Analysis of the data was performed by the Kruskal-Wallis test for numerical data and Pearson or Yates for categorical variables. RESULTS: A total of 75 patients were included in the study. The overall prevalence of polyomavirus DNA urinary shedding was 67/75 (89.3%). Only BKV DNA was detected in 14/75 (18.7%) urine samples, and only JCV DNA was detected in 11/75 (14.7%) samples. Both BKV and JCV DNA were present in 42/75 (56.0%) samples. CONCLUSION: In this study we found high rates of excretion of JCV, BKV, and simultaneous excretion in HIV+ patients. Also these results differ from the others available on the literature.

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INTRODUCTION: Data on recurrence after operation for intrahepatic cholangiocarcinoma (ICC) are limited. We sought to investigate rates and patterns of recurrence in patients after operative intervention for ICC. METHODS: We identified 301 patients who underwent operation for ICC between 1990 and 2011 from an international, multi-institutional database. Clinicopathologic data, recurrence patterns, and recurrence-free survival (RFS) were analyzed. RESULTS: During the median follow up duration of 31 months (range 1-208), 53.5% developed a recurrence. Median RFS was 20.2 months and 5-year actuarial disease-free survival, 32.1%. The most common site for initial recurrence after operation of ICC was intrahepatic (n = 98; 60.9%), followed by simultaneous intra- and extrahepatic disease (n = 30; 18.6%); 33 (21.0%) patients developed extrahepatic recurrence only as the first site of recurrence. Macrovascular invasion (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.34-3.21; P < .001), nodal metastasis (HR, 1.55; 95% CI, 1.01-2.45; P = .04), unknown nodal status (HR, 1.57; 95% CI, 1.10-2.25; P = .04), and tumor size ≥5 cm (HR, 1.84; 95% CI, 1.28-2.65; P < .001) were independently associated with increased risk of recurrence. Patients were assigned a clinical score from 0 to 3 according to the presence of these risk factors. The 5-year RFS for patients with scores of 0, 1, 2, and 3 was 61.8%, 36.2%, 19.5%, and 9.6%, respectively. CONCLUSION: Recurrence after operative intervention for ICC was common. Disease recurred both at intra- and extrahepatic sites with roughly the same frequency. Factors such as lymph node metastasis, tumor size, and vascular invasion predict highest risk of recurrence.

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RESUMO: O maraviroc (MVC) é o único anti-retroviral antagonista do co-receptor CCR5 licenciado e interage com as ansas transmembranares de CCR5, induzindo uma alteração da sua conformação e impedindo a interacção com gp120. O MVC é activo apenas contra estirpes R5 de HIV-1, sendo utilizado em terapia de recurso. Neste trabalho, foi estudada a diversidade genética da região C2V3C3 do gene env de estirpes de HIV-1 de oxicodependentes por via endovenosa da Grande Lisboa, pesquisando-se também a presença de polimorfismos genéticos naturais. Foram utilizadas 52 amostras de plasma e para 35 destas foi amplificado por RT-nested PCR um produto de 565 pb. A análise filogenética revelou a seguinte distribuição de genótipos: 23 B (incluindo, provavelmente, 2 CRF14_BG), 8 A, 3 G e 1 F1. Após tradução, e por comparação com a sequência consenso B, verificou-se uma elevada frequência de polimorfismos genéticos, sendo encontradas algumas “assinaturas de aminoácidos” relativas aos subtipos não-B. Realizou-se ainda uma pesquisa de locais de N-glicosilação e a previsão da utilização de co-receptores (abordagem genotípica), com recurso às regras 11/25 e da carga líquida da ansa V3 e aos programas PSSM e geno2pheno[coreceptor]. Observou-se uma conservação genérica do número de locais de N-glicosilação e foram identificadas 5 sequências com tropismo X4 ou duplo. Por fim, com base na literatura, realizou-se uma pesquisa de polimorfismos genéticos associados a resistência ao MVC presentes na ansa V3. Foi observado um número elevado destas mutações. A presença dos padrões 11S+26V e 20F+25D+26V, num total de 3 sequências, é relevante, visto estes estarem inequivocamente associados à resistência in vivo ao MVC. Apesar de não estar ainda definido um perfil de resistência para o MVC, a presença das mutações encontradas, em indivíduos sem contacto prévio com o fármaco, trará implicações relevantes na sua gestão clínica, considerando a introdução do MVC na terapia de recurso.---------- ABSTRACT: Maraviroc (MVC) is the only CCR5 inhibitor licensed today. This drug interacts with the transmembrane helices of CCR5 co-receptor, inducing a conformation change of its extracellular loops and preventing the interaction with gp120. MVC is only active against R5 strains of HIV-1 and is currently used in salvage therapy. The genetic diversity of the env C2V3C3 region of HIV-1 strains from injecting drug users in the Greater Lisbon was studied, along with the presence of natural genetic polymorphisms. 52 plasma samples were used and the amplification by RT-nested PCR of a 565 bp-product was possible in 35 of them. The phylogenetic analysis revealed 23 sequences classified as subtype B (probably including 2 CRF14_BG), 8 A, 3 G and 1 F1. After translation, the presence of natural genetic polymorphisms was studied by comparison to a subtype B consensus. A high frequency of genetic polymorphisms was observed and significant “amino acid signatures” were found in association with non-B subtypes. A full characterization of the N-glycosylation sites was also performed and a coreceptor prediction (genotypic approach) was accomplished using the 11/25 and the V3 net charge rules and the programs PSSM and geno2pheno[coreceptor]. The number of N-glycosylation sites was generically preserved. Five sequences were defined as X4 or dual-tropic. Based on published data, a search for genetic polymorphisms, present in V3loop, associated to MVC resistance was finally undertaken. Several of such mutations were observed, being particularly interesting the presence of the patterns 11S+26V and 20F+25D+26V, in a total of 3 sequences, since these patterns have unequivocally been associated with MVC resistance in vivo. Although a resistance profile for MVC is not yet defined, the presence of these mutations in MVC-naïve populations may have significant impact in their clinical management in the future, especially considering the introduction of this drug in salvage therapy.

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Fasciolosis is a disease of importance for both veterinary and public health. For the first time, georeferenced prevalence data of Fasciola hepatica in bovines were collected and mapped for the Brazilian territory and data availability was discussed. Bovine fasciolosis in Brazil is monitored on a Federal, State and Municipal level, and to improve monitoring it is essential to combine the data collected on these three levels into one dataset. Data were collected for 1032 municipalities where livers were condemned by the Federal Inspection Service (MAPA/SIF) because of the presence of F. hepatica. The information was distributed over 11 states: Espírito Santo, Goiás, Minas Gerais, Mato Grosso do Sul, Mato Grosso, Pará, Paraná, Rio de Janeiro, Rio Grande do Sul, Santa Catarina and São Paulo. The highest prevalence of fasciolosis was observed in the southern states, with disease clusters along the coast of Paraná and Santa Catarina and in Rio Grande do Sul. Also, temporal variation of the prevalence was observed. The observed prevalence and the kriged prevalence maps presented in this paper can assist both animal and human health workers in estimating the risk of infection in their state or municipality.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Anopheles (Kerteszia) cruzii has been implicated as the primary vector of human and simian malarias out of the Brazilian Amazon and specifically in the Atlantic Forest regions. The presence of asymptomatic human cases, parasite-positive wild monkeys and the similarity between the parasites infecting them support the discussion whether these infections can be considered as a zoonosis. Although many aspects of the biology of An. cruzii have already been addressed, studies conducted during outbreaks of malaria transmission, aiming at the analysis of blood feeding and infectivity, are missing in the Atlantic Forest. This study was conducted in the location of Palestina, Juquitiba, where annually the majority of autochthonous human cases are notified in the Atlantic Forest of the state of São Paulo. Peridomiciliary sites were selected for collection of mosquitoes in a perimeter of up to 100 m around the residences of human malaria cases. The mosquitoes were analyzed with the purpose of molecular identification of blood-meal sources and to examine the prevalence of Plasmodium. A total of 13,441 females of An. (Ker.) cruzii were collected. The minimum infection rate was calculated at 0.03% and 0.01%, respectively, for P. vivax and P. malariae and only human blood was detected in the blood-fed mosquitoes analyzed. This data reinforce the hypothesis that asymptomatic human carriers are the main source of anopheline infection in the peridomiciliary area, making the probability of zoonotic transmission less likely to happen.