946 research outputs found
Chemical Composition and larvicidal activity against Aedes aegypti of essential oils from Croton jacobinenesis Baill
The chemical composition of essential oils from leaves, stalks and inflorescences of Croton jacobinensis obtained by hydrodistillation were analyzed by GC-MS. E-caryophyllene, 1,8-cineole, α-pinene, viridiflorene, -cadinene were the main components in essential oils from plant parts. Essential oils of leaves, stalks, and inflorescences were tested at different concentrations against instar III larvae of Aedes aegypti and showed LC50 of 79.3, 117.2, 65.8 μg/ml, respectively
Use of threshold electrolyte concentration analysis to determine salinity and sodicity limit of irrigation water
This research studied threshold electrolyte concentration (TEC) of irrigation water and its effect on the infiltration rate of two contrasting soils from Pernambuco state, Brazil. The experiment was conducted in the Soil Chemistry and Salinity Laboratory of Federal Rural University of Pernambuco. Each soil was packed in five Buchner funnels, where one funnel from each soil was submitted to treatment with solution of electrical conductivity (EC) of 0.5, 1.0, 2.0, 4.0 or 8.0 dS m-1. For each funnel containing soil, an increasing ratio of NaCl to CaCl2 was applied in a treatment solution to achieve 10 increasing values of sodium adsorption ratio (SAR) from 0 to 100. These solutions were applied through a Mariotte bottle, with a constant hydraulic head of ~2 cm (pressure potential). After a liter of solution had drained, in the flux was collected for a known time interval, until steady state was reached. Darcy's equation was used to calculate saturated hydraulic conductivity (Ksat) and a mathematical model used to calculate the TEC as a 20% reduction in Ksat. By increasing SAR similar behavior was noted between the two soils, whereby Ksat decreased, although the relative decrease in Ksat was greater for SAR of 100 in the soil with higher clay content
Lower respiratory tract infections among human immunodeficiency virus-exposed, uninfected infants
Objectives: To evaluate whether maternal HIV disease severity during pregnancy is associated with an increased likelihood of lower respiratory tract infections (LRTIs) in HIV-exposed, uninfected infants.Methods: HIV-exposed, uninfected, singleton, term infants enrolled in the NISDI Perinatal Study, with birth weight >2500 g were followed from birth until 6 months of age. LRTI diagnoses, hospitalizations, and associated factors were assessed.Results: of 547 infants, 103 (18.8%) experienced 116 episodes of LRTI (incidence = 0.84 LRTIs/100 child-weeks). Most (81%) episodes were bronchiolitis. Forty-nine (9.0%) infants were hospitalized at least once with an LRTI. There were 53 hospitalizations (45.7%) for 116 LRTI episodes. None of these infants were breastfed. the odds of LRTI in infants whose mothers had CD4% = 29 (p = 0.003). the odds of LRTI in infants with a CD4+ count (cells/ mm(3)) = 750 (p = 0.002). Maternal CD4+ decline and infant hemoglobin at the 6-12 week visit were associated with infant LRTIs after 6-12 weeks and before 6 months of age.Conclusions: Acute bronchiolitis is common and frequently severe among HIV-exposed, uninfected infants aged 6 months or less. Lower maternal and infant CD4+ values were associated with a higher risk of infant LRTIs. Further understanding of the immunological mechanisms of severe LRTIs is needed. (C) 2010 International Society for Infectious Diseases. Published by Elsevier B.V. All rights reserved.NICHDUniv São Paulo, Fac Med Ribeirao Preto, BR-14049900 Ribeirao Preto, SP, BrazilWESTAT Corp, Rockville, MD 20850 USAUniv Caxias Sul, Rio Grande Do Sul, BrazilHosp Diego Paroissien, Buenos Aires, DF, ArgentinaUniversidade Federal de São Paulo, São Paulo, BrazilUniv W Indies, Kingston 7, JamaicaHosp Juan Fernandez, Buenos Aires, DF, ArgentinaHosp Agudos Dra Cecilia Grierson, Buenos Aires, DF, ArgentinaNICHD, Pediat Adolescent & Maternal AIDS Branch, CRMC, NIH,DHHS, Bethesda, MD USAUniversidade Federal de São Paulo, São Paulo, BrazilNICHD: N01-HD-3-3345NICHD: HHSN267200800001CNICHD: N01-DK-8-0001Web of Scienc
Reconcentração do sêmen congelado de carneiros por centrifugação da palheta após a descongelação: efeito sobre a cinética espermática.
A inseminação artificial cervical (IAC) mostra-se uma opção economicamente viável para o incremento da produção de ovinos, desde que se consiga minimizar as dificuldades inerentes à técnica e à espécie e que se maximizem seus índices de fertilidade. O refluxo seminal durante a IAC devido à limitada capacidade volumétrica da cérvix promove uma diminuição de sêmen e consequentemente de espermatozoides disponíveis para o transporte ao sitio de fertilização. Nessa perspectiva, a centrifugação do sêmen ovino surge como alternativa para se depositar um elevado número de espermatozoides viáveis, em pequenos volumes de dose inseminante. O objetivo deste trabalho foi avaliar o efeito da centrifugação do sêmen descongelado sobre a cinética espermática a fim de analisar a viabilidade da reconcentração dos espermatozoides como meio de redução do volume da dose inseminante. Amostras de sêmen de cinco carneiros da raça Santa Inês foram congeladas em palhetas de 0,25 mL contendo 100 x 106 espermatozoides e submetidas à centrifugação por 10 minutos após a descongelação (37°C/ 30 segundos) para posteriormente serem avaliadas de acordo com os seguintes grupos de amostras removidas das palhetas: antes da centrifugação (NC ? Controle) e, pós-centrifugação a 800 (96 g), 1000 (150 g) e 1200 (217 g) rpm. Foi realizada a análise da cinética espermática através de sistema computadorizado no momento da descongelação (T0h) e após incubação à 37ºC por 2h (T2h) e 4h (T4h) sendo avaliados os parâmetros: motilidades total (MT) e progressiva (MP); velocidades do percurso médio (VAP), em linha reta (VSL) e curvilínea (VCL); retilinearidade (STR) e; linearidade (LIN). A maior força centrifuga usada (1200rpm - 217g) aumentou significativamente (p0,05) para nenhum dos parâmetros cinéticos testados. A centrifugação da palheta de sêmen congelado de carneiros após descongelação a uma força centrífuga de 1200rpm (217g) durante dez minutos promove um aumento na velocidade cinética e não afeta a proporção de células com motilidade total e progressiva, linearidade e retilinearidade dos espermatozoides, podendo ser utilizada como estratégia de reconcentração espermática para redução do volume da dose inseminante e de refluxo seminal nas inseminações cervicais
Prevalence of smoking and incidence of initiation in the Latin American adult population: the PLATINO study
Background: the PLATINO project was launched in 2002 in order to study the prevalence of chronic obstructive pulmonary disease (COPD) in Latin America. Because smoking is the main risk factor for COPD, detailed data on it were obtained. the aim of this paper was to evaluate the prevalence of smoking and incidence of initiation among middle-aged and older adults (40 years or older). Special emphasis was given to the association between smoking and schooling.Methods: PLATINO is a multicenter study comprising five cross-sectional population-based surveys of approximately 1,000 individuals per site in São Paulo (Brazil), Santiago (Chile), Mexico City (Mexico), Montevideo (Uruguay) and Caracas (Venezuela). the outcome variable was smoking status (never, former or current). Current smokers were those who reported to smoke within the previous 30 days. Former smokers were those who reported to quit smoking more than 30 days before the survey. Using information on year of birth and age of smoking onset and quitting, a retrospective cohort analysis was carried out. Smoking prevalence at each period was defined as the number of subjects who started to smoke during the period plus those who were already smokers at the beginning of the period, divided by the total number of subjects. Incidence of smoking initiation was calculated as the number of subjects who started to smoke during the period divided by the number of non-smokers at its beginning. the independent variables included were sex, age and schooling.Results: Non-response rates ranged from 11.1% to 26.8%. the prevalence of smoking ranged from 23.9% (95% CI 21.3; 26.6) in São Paulo to 38.5% (95% CI 35.7; 41.2) in Santiago. Males and middle-aged adults were more likely to smoke in all sites. After adjustment for age, schooling was not associated with smoking. Using retrospective cohort analysis, it was possible to detect that the highest prevalence of smoking is found between 20-29 years, while the highest incidence is found between 10-19 years. Age of smoking onset tended to decline over time among females.Conclusion: the prevalence of smoking varied considerably across sites, but was lower among countries with national anti-smoking campaigns.Univ Fed Pelotas, Pelotas, BrazilUniv Republica, Montevideo, UruguayInst Nacl Enfermedades Resp, Mexico City, DF, MexicoUniversidade Federal de São Paulo, São Paulo, BrazilPontificia Univ Catolica Chile, Santiago, ChileCent Univ Venezuela, Caracas, VenezuelaUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Chemical composition, cytotoxicity and larvicidal activity against Aedes aegypti of essential oils from Vitex gardineriana Schauer
Vitex gardneriana Schauer (Lamiaceae) popularly known as “jaramataia”, is a shrub commonly found in caatinga biome located in Northeast Brazil. In folk medicine, its leaves have been used as analgesic and anti-inflammatory agents. The chemical composition of the essential oil from leaves obtained by hydrodistillation was analyzed and identified by GC-MS and GC-FID and showing a total of 26 constituents (95.9%) being 2 monoterpenes (0.4%) and 24 sesquiterpenes (95.4%). The main constituents identified were cis-calamenene (29.7%), 6,9-guaiadiene (14.5%) and caryophyllene oxide (14.0%). The essential oil has been demonstrated high larvicidal activity againstAedes aegypti (LC50 = 28.0 μg/mL). In the evaluation of the bioassay with Artemia salina the essential oil showed LC50 = 98.11 μg/mL. Inaddition, the essential oil did not show cytotoxicity (IC50 > 2.50 mg/mL) by the hemolysis assay
Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.
BACKGROUND: The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. METHODS: We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). PRINCIPAL FINDINGS/CONCLUSIONS: We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically diverse sites. Further genome-wide analyses are required to test the demographic scenario suggested by our data
Results from portable and of low cost equipment developed for detection of milk adulterations
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