Nitrogen fertilizer (15N) leaching in a central pivot fertigated coffee crop

Nitrogen has a complex dynamics in the soil-plant-atmosphere system. N fertilizers are subject to chemical and microbial transformations in soils that can result in significant losses. Considering the cost of fertilizers, the adoption of good management practices like fertigation could improve the N use efficiency by crops. Water balances (WB) were applied to evaluate fertilizer N leaching using 15N labeled urea in west Bahia, Brazil. Three scenarios (2008/2009) were established: i) rainfall + irrigation the full year, ii) rainfall only; and iii) rainfall + irrigation only in the dry season. The water excess was considered equal to the deep drainage for the very flat area (runoff = 0) with a water table located several meters below soil surface (capillary rise = 0). The control volume for water balance calculations was the 0 - 1 m soil layer, considering that it involves the active root system. The water drained below 1 m was used to estimate fertilizer N leaching losses. WB calculations used the mathematic model of Penman-Monteith for evapotranspiration, considering the crop coefficient equal to unity. The high N application rate associated to the high rainfall plus irrigation was found to be the main cause for leaching, which values were 14.7 and 104.5 kg ha-1 for the rates 400 and 800 kg ha-1 of N, corresponding to 3.7 and 13.1 % of the applied fertilizer, respectively.

Use efficiency of variable rate of nitrogen prescribed by optical sensor in corn

ABSTRACT The efficiency of nitrogen fertilizer in corn is usually low, negatively affecting plant nutrition, the economic return, and the environment. In this context, a variable rate of nitrogen, prescribed by crop sensors, has been proposed as an alternative to the uniform rate of nitrogen traditionally used by farmers. This study tested the hypothesis that variable rate of nitrogen, prescribed by optical sensor, increases the nitrogen use efficiency and grain yield as compared to uniform rate of nitrogen. The following treatments were evaluated: 0; 70; 140; and 210 kg ha-1 under uniform rate of nitrogen, and 140 kg ha -1 under variable rate of nitrogen. The nitrogen source was urea applied on the soil surface using a distributor equipped with the crop sensor. In this study, the grain yield ranged from 10.2 to 15.5 Mg ha-1, with linear response to nitrogen rates. The variable rate of nitrogen increased by 11.8 and 32.6% the nitrogen uptake and nitrogen use efficiency, respectively, compared to the uniform rate of nitrogen. However, no significant increase in grain yield was observed, indicating that the major benefit of the variable rate of nitrogen was reducing the risk of environmental impact of fertilizer.

Organização e desempenho: avaliação da centralização da patologia do INCA-Brasil

A literatura atribui à descentralização da estrutura organizacional efeitos positivos sobre a orientação empreendedora e o desempenho da firma; existem também evidências de efeito positivo da centralização dos procedimentos complexos em hospitais de grande porte sobre os resultados do tratamento do câncer. O objetivo deste estudo é avaliar os efeitos da centralização dos laboratórios de anatomia patológica do Instituto Nacional do Câncer (INCA) brasileiro, em 2002, sobre o desempenho da atividade de diagnóstico e controle do câncer. A análise é desenvolvida com o cálculo de uma fronteira eficiente não paramétrica de produção no período 1997-2007, por meio da Análise Envoltória de Dados (DEA). O resultado é que a centralização reverteu a queda de eficiência técnica dos laboratórios no período 1997-2001. A conclusão do artigo é que o Modelo DEA traz um aporte ao conhecimento sobre a mudança de estrutura organizacional nas organizações públicas de saúde e uma contribuição gerencial sobre a eficácia da centralização para melhorar o suporte laboratorial da patologia aos hospitais do INCA.

Perfil da automedicação em município do Sul do Brasil

OBJETIVO: Caracterizar o usuário de medicamentos, especialmente aquele que se automedica. MATERIAL E MÉTODO: Foram entrevistadas 413 pessoas do Município de Santa Maria, Estado do Rio Grande do Sul, Brasil, sobre o consumo de medicamentos no último mês. RESULTADOS: Dos entrevistados, 69,9% utilizaram medicamentos e destes 76,1% o fizeram através de automedicação. Cefaléia (28,8%) foi a principal queixa motivadora de automedicação. O ácido acetilsalicílico foi a droga mais utilizada (25,4%). Dos fármacos utilizados na automedicação, 51,2% foram indicados por terceiros e 51,7% dessas indicações eram prescrições médicas emitidas em consultas anteriores. CONCLUSÃO: Idade, grau de escolaridade e acompanhamento médico periódico correlacionaram-se significativamente com automedicação.

Resposta dos plasmódios humanos aos antimaláricos na ilha de São Luís, estado do Maranhão, Brasil

Os Autores estudaram a resposta dos plasmódios humanos "in vivo" aos antimaláricos na Ilha de São Luís, Estado do Maranhão, Brasil, durante os anos de 1981 e 1982. No tratamento de malária por P. falciparum definem o atual estado da resistência à cloroquina (25,9%) e a associação sulfamídicos e pirimetamina (16%). Quanto ao tratamento da malária por P. vivax, obtém índices de cura de 94,4% e 96% respectivamente, para dois esquemas testados. Finalmente, proclamam a utilização da associação cloroquina, primaquina e pirimetamina, em três dias, como o tratamento mais eficaz e de menor custo. Também a associação sulfamídicos e pirimetamina e a quinina ainda como drogas alternativas para tratamento do P. falciparum resistente dos 4-amino-quinoleínicos.

Jorge Lobo’s disease: experimental inoculation in Swiss mice

Sixty-four isogenic Swiss mice were intradermically inoculated in both hind foot pads. The inocula, consisting of fungal suspensions from biopsies obtained from Jorge Lobo’s Disease patients, had the total number of fungi and the viability index determined using a Neubauer chamber and the fluorescein diacetate-ethidium bromide technique (FD-EB), respectively. The animals were sacrificed at times ranging from ten days to eighteen months after inoculation. The cellular infiltrate, mainly consisting of macrophages containing fungi, increased progressively up to end of the study; however, no macroscopic alterations were observed in the inoculated feet. After nine months, small numbers of Langhans’ giant cells started to appear in the infiltrate. A considerable number of fungi was observed at the end of the experimental period, but only a few were viable when stained by the FD-EB technique. This fact suggests that there is a multiplication of fungal cells, which are destroyed by the macrophages but remain in the tissue for a long time due perhaps to the difficulties in their elimination. These findings led us to conclude that in spite of the maintenance of the infection in these animals, Swiss mice cannot be considered an ideal model to study Jorge Lobo’s Disease. However, the authors call attention to the possibility of other mouse strains being more susceptible to Paracoccidioides loboi.

Ten years experience with Jorge Lobo's disease in the state of Acre, Amazon region, Brazil

Jorge Lobo's disease is a cutaneous and subcutaneous mycosis that affects patients in the Amazon region. The number of patients is relatively small, but the real situation of the disease as public health problem is not known, because Jorge Lobo's disease is not a notifiable disease. This study aims to report the clinical evolution in patients affected and to determine the prevalence and areas of occurrence of the disease. A retrospective study was carried out based on the analysis of the clinical records, which included a collection of photographs of patients in the Department of Sanitary Dermatology, in Rio Branco, and patients seen in the interior of the state. In a decade, in Rio Branco, 249 cases of the disease were reported, 30 were females and 219 males. Of these patients, 153 had localized lesions, 94 of them were on one ear, 55 had multifocal lesions and 41 had disseminated lesions. The average time between the onset of symptoms and diagnosis was 19 years. The average age at the time of diagnosis was 53 years, and ages ranged from 14 to 96 years.

Envenoming by coral snakes (Micrurus) in Argentina, during the period between 1979-2003

Envenomation by coral snakes (Micrurus sp.) is one of the most dangerous injuries in America and it is considered as a serious medical emergency, however bites by these snakes appear to be rare. We analyzed epidemiological data, clinical signs and antivenom use in Argentina during the period between 1979-2003. During this period of study 46 non-fatal Micrurus bites were reported. The majority of cases were men from 31 to 40 years old. Bites occurred primarily in spring and summer. Most cases were reported from the northeast and northwest provinces of the country. The bites were mostly located on hands or feet and occurred mostly during agricultural activities and so mainly involved farmers. Only four cases occurred as a result of handling snakes. The median time it took for antivenom to be administrated was 60 minutes after the bite, and the median number of vials applied was 2. Local pain was mentioned and edema was reported in 41% of patients. All patients recovered without sequelae. This study showed a low incidence of Micrurus bites and low severity of envenomation. However, although no deaths have been reported during the last 30 years, given the toxicity of the venom of Micrurus snakes, the risk of severe envenomation should be considered.

Evaluation of the phagocytic activity of peripheral blood monocytes of patients with Jorge Lobo's disease

Studies on host-parasite interaction in Jorge Lobo's disease are scarce, with no report in the literature on the phagocytosis of Lacazia loboi by phagocytic mononuclear cells. Thus, the objective of the present study was to assess the phagocytic activity of blood monocytes in the presence of L. loboi in patients with the disease and in healthy subjects (controls) over 3 and 24 hours of incubation. Statistical analyses of the results showed no significant difference in percent phagocytosis of the fungus between patient and control monocytes. With respect to incubation time, however, there was a significant difference, in that percent phagocytosis was higher at 3 hours than at 24 hours (p <0.01). These results suggest that monocytes from patients with the mycosis are able to phagocyte the fungus, as also observed in control individuals.

Estudo de associação entre antígenos leucocitários humanos e doença de Jorge Lobo

A doença de Jorge Lobo é uma micose cutânea/subcutânea de evolução crônica, causada pelo fungo Lacazia loboi. Devido às características epidemiológicas e poucos estudos relacionados aos aspectos imunológicos dessa doença, o objetivo do trabalho foi investigar uma possível associação das especificidades HLA de classe II em 21 pacientes portadores da doença de Jorge Lobo, comparando com indivíduos sadios de mesma etnia. As tipificações HLA foram realizadas pelo método de PCR-SSP. O resultado não revelou qualquer tipo de associação entre os antígenos HLA e doença de Jorge Lobo. Embora sem significância estatística, foi observada a diminuição da freqüência do antígeno HLA-DR7 no grupo dos pacientes em relação aos controles (0% x 18%), sugerindo uma associação negativa (protetora) entre HLA-DR7 e doença de Jorge Lobo. Contudo, estudos devem ser continuados, objetivando melhor entendimento nos mecanismos envolvidos na suscetibilidade e/ou proteção dessa doença.

Controle da malária no Estado do Maranhão

Este estudo objetiva mostrar os resultados do controle da malária no Estado do Maranhão, com base nos Planos Estaduais de Controle e na série histórica dos registros de malária, no período de 1999 a 2007. A evolução da malária foi analisada comparando-se a incidência parasitária anual (total de casos notificados por 1.000 habitantes) por Região Geográfica, por Unidades Regionais de Saúde e pelos 46 municípios incluídos nos Planos. A análise dos resultados permitiu concluir pela eficácia dos Planos, pois a incidência anual apresentou redução de 10,1 casos para 1,1 casos por 1000 habitantes, uma regressão de 89,1%, a maior entre todos os estados amazônicos.

Persistent asthma in adults: comparison of high resolution computed tomography of the lungs after one year of follow-up

OBJECTIVE: The aims of this study were to evaluate the role of high resolution computed tomography of the torax in detecting abnormalities in chronic asthmatic patients and to determine the behavior of these lesions after at least one year. METHOD: Fourteen persistent asthmatic patients with a mean forced expiratory volume in 1-second that was 63% of predicted and a mean forced expiratory volume in 1-second /forced vital capacity of 60% had two high resolution computed tomographys separated by an interval of at least one year. RESULTS: All 14 patients had abnormalities on both scans. The most common abnormality was bronchial wall thickening, which was present in all patients on both computed tomographys. Bronchiectasis was suggested on the first computed tomography in 5 of the 14 (36%) patients, but on follow-up, the bronchial dilatation had disappeared in 2 and diminished in a third. Only one patient had any emphysematous changes; a minimal persistent area of paraseptal emphysema was present on both scans. In 3 patients, a "mosaic" appearance was observed on the first scan, and this persisted on the follow-up computed tomography. Two patients had persistent areas of mucoid impaction. In a third patient, mucus plugging was detected only on the second computed tomography. CONCLUSIONS: We conclude that there are many abnormalities on the high resolution computed tomography of patients with persistent asthma. Changes suggestive of bronchiectasis, namely bronchial dilatation, frequently resolve spontaneously. Therefore, the diagnosis of bronchiectasis by high resolution computed tomography in asthmatic patients must be made with caution, since bronchial dilatation can be reversible or can represent false dilatation. Nonsmoking chronic asthmatic subjects in this study had no evidence of centrilobular or panacinar emphysema.