17 research outputs found
Effective Lagrangian description of the lepton flavor violating decays Z-->li lj
A comprehensive analysis of the lepton flavor violating (LFV) decays Z-->li
lj is presented within the effective Lagrangian approach. Both the decoupling
and nondecoupling scenarios are explored. The experimental constraints from li
--> lj lk \bar{lk} and li -->lj gamma as well as some relationships arising
from the gauge invariance of the effective Lagrangian are used to put
constraints on Z-->li lj. It is found that while current experimental data
impose very strong constraints on Z-->mu e, the channel Z --> tau mu (e)still
may be at the reach of the planned TESLA collider.Comment: References added, final version to appear in Physical Review
Comportamento e avaliação de metais potencialmente tóxicos (Cu (II), Cr (III), Pb(II) e Fe(III)) em águas superficiais dos Riachos Capivara e Bacuri Imperatriz-MA, Brasil
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Plant extracts for controlling the post-harvest anthracnose of banana fruit
In banana, fruit rot is incited by Colletotrichum musae which has been the most serious post-harvest disease of immature and mature fruit. The usual control by fungicides prohibited in many countries reduces their commercial value. Therefore, two experiments were conducted to evaluate the antimicrobial activity of alternative products to the synthetic fungicides. First, berries naturally infected by anthracnose were immersed into Azadirachta indica and citric extracts at 2 and 4% (v/v) for 3 minutes and stored for 11 days under environmental conditions. Next, other berries were immersed into essential oil emulsions of Allium sativum, Copaifera langsdorfii, Cinnamomum zeylanicum and Eugenia caryophyllata at 5% for 3 minutes but stored for 11 days. Berries immersed into distilled water were used as control-treatments. The percentage of disease incidence observed in the control-treatment was similar to the ones observed in the extract of A. indica at 2%. The control-treatment showed disease severity of 75.13% and the percentage of disease control was 20.85%. Fruit immersed into distilled water presented less effectiveness than the ones immersed into citric extracts, which promoted the highest effectiveness. Citric extract at 4% was the most efficient treatment because the disease incidence was 19.44%, the disease severity was 9.34% and the disease control was 90.16%. Less severity and, consequently, more disease control were achieved by immersing the berries into the emulsion of essential oil of A. sativum, followed by treatments with C. langsdorfii, E. caryophyllata and C. zeylanicum
Efeito de níveis de nitrogênio e fósforo no desenvolvimento de mudas de guaranazeiro (Paullinia cupana (Mart.) Ducke), em condições de viveiro
Caracterização química de extratos hidrossolúveis desidratados de arroz e soja Chemical characterization of dehydrated rice and soybean water-soluble extracts
O presente trabalho teve por objetivo caracterizar quimicamente os extratos hidrossolúveis desidratados de arroz (Oryza sativa L.) e de soja (Glycine max (L.) Merrill). Os processos utilizados para a obtenção dos extratos hidrossolúveis foram: maceração do arroz e da soja, desintegração, centrifugação, adição de ácido cítrico, fervura e secagem por atomização. A caracterização química foi realizada através das seguintes determinações: composição centesimal aproximada, composição de minerais e atividade do inibidor de tripsina. Com o aumento das proporções de soja (0 a 50%), os extratos hidrossolúveis desidratados tiveram aumento nos teores de proteína, extrato etéreo, cinzas e fibra crua, porém diminuição no teor de carboidratos. Os teores de P, K, Mg, Cu e Co foram altos em alguns extratos hidrossolúveis desidratados estudados, os quais foram semelhantes à indicação diária na "Recommended Dietary Allowances", enquanto os demais minerais se mostraram em pequenas quantidades ou apenas traços. Não foi detectada atividade do inibidor de tripsina.<br>The objective of the present study was to evaluate the chemical characteristics of dehydrated water-soluble extracts of rice (Oryza sativa L.) and soybean (Glycine max (L.) Merrill). The preparation included soaking of the rice and soybean, desintegration, centrifugation, addition of citric acid, boiling and spray drying. Dehydrated water-soluble extracts were analysed for their proximate composition, minerals content and trypsin inhibitor activity. Results indicated that an increase in the proportion of soybean (0 to 50%) resulted in an increase in the content of proteins, oil, ash, crude fiber, as well as a decrease in the percentage of carbohydrates. The content of P, K, Mg, Cu and Co in some of the extracts were particularly high and were comparable with those of the Recommended Dietary Allowances. Other minerals were detected in low or trace amounts. No trypsin inhibitor activity was detected
Geoprocessamento aplicado à observação da sazonalidade das larvas da mosca Dermatobia hominis no município de Seropédica - RJ
Serological follow-up of patients with paracoccidioidomycosis treated with itraconazole using Dot-blot, ELISA and Western-blot
Twenty-seven mycologically proven cases of paracoccidioidomycosis (PCM) were treated with itraconazole (100-200 mg/day in month 1 and 100 mg/day until month 6-8) and evaluated clinically and serologically, up to 3.5 years post-therapy, using Dot-blot and ELISA for measuring the titers of IgG, IgA and IgM anti-P. brasiliensis antibodies and Western-blot for determining IgG, IgA and IgM antibodies against the antigen components of the fungus. Before treatment, 81.5% (Dot-blot) and 84% (ELISA) of the patients presented elevated IgG anti-P. brasiliensis antibody titers which dropped slightly with treatment. On the other hand, the percentages of pre-treatment high-titered sera for IgA and IgM anti-P.brasiliensis were lower (5l.9% and 5l.8%: Dot-blot; 16.5 and 36%: ELISA, respectively) but the titers tended to become negative more frequently with treatment. Prior to treatment, the percentages of positivity for IgG, IgA and IgM anti-P.brasiliensis antibodies in Western-blot were 96%, 20.8% and 41.6%, respectively. Antigens with molecular weights varying from 16-78 kDa, from 21-76 kDa and from 27-78 kDa were reactive for IgG, IgA and IgM antibodies, respectively. The most frequently reactive antigenic components had molecular weights of 27, 33 and 43 kDa for IgG, and 70 for IgA and IgM antibodies. During the period of study, the patients responded well to treatment. The present data confirm the diversity and complexity of the humoral response in PCM, and the importance of utilizing different serological tests to detect IgG, IgA and IgM anti-P. brasiliensis antibodies<br>Vinte e sete pacientes portadores de paracoccidioidomicose (PCM) foram tratados com itraconazole (100-200 mg/dia no primeiro mês e 100 mg/dia até 6-8 meses) e avaliados sob o ponto de vista clínico e sorológico, até 3 e meio anos após o início do tratamento, utilizando-se os testes de Dot-blot e ELISA para medir os títulos de anticorpos IgG, IgA e IgM anti-P. brasiliensis, e Western-blot para determinar os anticorpos IgG, IgA e IgM contra os componentes antigênicos do fungo. Antes do tratamento, 81,5% (Dot-blot) e 84% (ELISA) dos pacientes apresentaram títulos elevados de anticorpos IgG anti-P. brasiliensis, que decresceram levemente com o tratamento. Por outro lado, as porcentagens de soros pré-tratamento com títulos elevados para anticorpos IgA e IgM foram menores (51,9% e 51,8%: Dot-blot; 16% e 36 %: ELISA, respectivamente); com o tratamento, entretanto, estes títulos tenderam mais frequentemente a se negativar. Antes do tratamento, as porcentagens de positividade para anticorpos IgG, IgA e IgM, avaliados por Western-blot, foram 96%, 20,8% e 41,6%, respectivamente. Componentes antigênicos de massas moleculares variando entre 16-78 kDa, 21-76 kDa e 27-78 kDa reagiram com anticorpos das classes IgG, IgA e IgM, respectivamente, As frações antigênicas com massas moleculares de 27, 33 e 43 kDa foram as mais frequentemente reativas com anticorpos da classe IgG, e a de 70 kDa para anticorpos IgA e IgM. Todos os pacientes apresentaram remissão da sintomatologia com o tratamento, durante o período de estudo. Os dados do presente trabalho confirmam a diversidade e a complexidade da resposta humoral dos pacientes com PCM e reforçam a importância de se utilizar diferentes testes sorológicos para se detectar anticorpos IgG, IgA e IgM anti- P. brasiliensis