701 research outputs found
Avaliação de estado nutricional da mangueira Tommy Atkins no submédio do vale do rio São Francisco: estabelecimento das normas DRIS
Este trabalho teve por objetivo estabelecer as
normas do sistema integrado de diagnose e recomendação
(DRIS) para manga, variedade Tommy Atkins. Foram
avaliados sessenta e três pomares comerciais
representativos do Submédio do Vale do Rio São Francisco,
no Nordeste do Brasil. A região não dispõe de um conjunto
de normas de diagnose de tecidos foliares para o cultivo,
sendo o diagnóstico do estado nutricional e as
recomendações de fertilização baseados em faixas de
teores de nutrientes em folhas de mangueira cultivadas em
diferentes regiões. Foram coletadas amostras de folhas
para análise química, antes da aplicação de quebradores de
dormência de brotos. As normas DRIS para nutrição das
plantas foram estabelecidas com base em um banco de
dados criado nesta pesquisa, envolvendo os nutrientes N, P,
K, Ca, Mg, B, Cu, Fe, Mn e Zn. Essas normas foram
estabelecidas considerando uma subpopulação de plantas
com produção igual ou superior a 250 kg/planta, produção
essa representativa para as condições ambientais da
principal zona produtora de manga do país. Das noventa
relações consideradas entre nutrientes, sessenta e duas
foram significativas pelo teste F, das quais, quarenta e
quatro foram selecionadas como normas para a cultura
Avaliação do estado nutricional da mangueira Tommy Atkins no submédio do vale do rio São Francisco: cálculo dos índices DRIS
O Sistema Integrado de Diagnose e
Recomendação, DRIS, é uma ferramenta importante na
avaliação do estado nutricional das plantas. Os objetivos do
presente trabalho foram avaliar o estado nutricional de
pomares de mangueira Tommy Atkins no Submédio do vale
do São Francisco, no Brasil, mediante o DRIS, relacionar os
índices com os teores foliares de nutrientes e discriminar a
ordem de limitação de cada nutriente nas subamostras de
alta e de baixa produtividade. Foram amostrados sessenta
e três pomares comerciais com sete ou mais anos de idade.
Com os teores foliares de macro e micronutrientes foram
calculados os índices DRIS, utilizando-se como referência
os dados da subpopulação de alta produtividade. Os
maiores valores de Índices de Balanço Nutricional médio
(IBNm) verificados em pomares de baixa produtividade
demonstraram o potencial deste índice na avaliação do
estado nutricional da mangueira, e a necessidade de
adubações mais criteriosas em tais pomares. A utilização do
conceito de potencial de resposta à adubação na
interpretação dos índices DRIS mostrou-se uma ferramenta
eficaz, principalmente nos pomares de baixa produtividade,
onde os desequilíbrios nutricionais foram maiores,
confirmando a seqüência de deficiência a excessos,
auxiliando o diagnóstico final, indicando os nutrientes que
realmente estão em deficiência ou em excesso
Status of a Supersymmetric Flavour Violating Solution to the Solar Neutrino Puzzle with Three Generations
We present a general study of a three neutrino flavour transition model based
on the supersymmetric interactions which violate R-parity. These interactions
induce flavour violating scattering reactions between solar matter and
neutrinos. The model does not contain any vacuum mass or mixing angle for the
first generation neutrino. Instead, the effective mixing in the first
generation is induced via the new interactions. The model provides a natural
interpretation of the atmospheric neutrino anomaly, and is consistent with
reactor experiments. We determine all R-parity violating couplings which can
contribute to the effective neutrino oscillations, and summarize the present
laboratory bounds. Independent of the specific nature of the (supersymmetric)
flavour violating model, the experimental data on the solar neutrino rates and
the recoil electron energy spectrum are inconsistent with the theoretical
predictions. The confidence level of the -analysis ranges between and . The incompatibility, is due to the new SNO
results, and excludes the present model. We conclude that a non-vanishing
vacuum mixing angle for the first generation neutrino is necessary in our
model. We expect this also to apply to the solutions based on other flavour
violating interactions having constraints of the same order of magnitude.Comment: 17 pages, Latex fil
Epidemiology of childhood and adolescent cancer in Bangladesh, 2001-2014
Background: Cancer burden among children and adolescents is largely unknown in Bangladesh. This study aims to provide a comprehensive overview on childhood and adolescent cancers and to contribute to the future strategies to deal with these diseases in Bangladesh. Methods: Data on malignant neoplasms in patients aged less than 20years diagnosed between 2001 and 2014 (N=3143) in Bangladesh was collected by the National Institute of Cancer Research and Hospital and ASHIC Foundation. The age pattern and distribution of cancer types were analysed and the incidence rates were calculated. Results: The age-standardised incidence rate was 7.8 per million person-years for children (0-14 years) in the last time period (2011-2014). Retinoblastoma (25%) and leukaemia (18%) were the most common childhood cancers. For adolescents (15-19 years), the age-specific incidence rate was 2.1 per million person-years in the same time period. Most common adolescent cancers were malignant bone tumours (38%), germ cell and gonadal tumours (17%), and epithelial tumours (16%). There were more boys affected (M: F ratio 2.0 in children and 1.4 in adolescents) than girls. Conclusion: Cancer incidences were lower than expected most likely due to a low level of awareness about cancer among clinicians and the population, inadequate access to health care, lack of diagnostic equipment and incomplete recording of cases. Improvements on different levels should be made to get a better epidemiologic insight and to detect cancer earlier resulting in a better outcome for affected chil
Qualidade pós-colheita de frutos de mangueira ("Mangifera indica" L.) var. 'Tommy Atkins' sob sistema orgânico no submédio São Francisco (Brasil)
O objetivo do trabalho foi avaliar a qualidade pós -
colheita de frutos de mangueira Tommy Atkins, cultivada sob
sistema orgânico. Os frutos foram avaliados logo ao
chegarem ao laboratório (0) e após armazenamento em
câmara fria a 10,5º ± 1 ºC e 85,5º ± 5 % de UR, durante, 14,
28 e 42 dias após a colheita (DAC), sendo que após cada
período, foram retirados da câmara fria e mantidos durante
quatro dias a 21 ± 1º C e 55-65 % de UR, após o que foram
caracterizados física, biológica e químicamente. O
delineamento experimental foi em blocos inteiramente ao
acaso. As médias foram comparadas pelo teste de Tukey.
Os frutos foram avaliados quanto a: perda de água e a
aparência, danos mecânicos, coloração da casca, firmeza
da polpa, ocorrência de colapso interno, escurecimento de
lenticelas, danos por lesões devido ao ataque de
Lasiodiplodia, Colletotrichum ou por Alternaria ou por tripes;
SST, ATT e o pH da polpa. As mangas estavam aptas para
o consumo por volta dos 18 DAC, tempo, mais do que
suficiente para se proceder ao transporte do produto até
mercados distantes, como o americano e o europeu
The processes in SM and MSSM
We present the results of a complete analysis of the one loop electroweak
corrections to in the Standard (SM) and
the Minimal Supersymmetric Standard Model (MSSM). A special emphasis is put on
the high energy behaviour of the various helicity amplitudes and the way the
logarithmic structure is generated. The large magnitude of these effects, which
induce striking differences between the SM and MSSM cases at high energies,
offers the possibility of making global tests which could check the consistency
of these models, and even decide whether any additional new physics is
required.Comment: Short version (16 pages and 9 figures) of the paper hep-ph/0207273,
to appear in Phy.Rev.D. e-mail: [email protected]
Search for heavy neutrinos mixing with tau neutrinos
We report on a search for heavy neutrinos (\nus) produced in the decay
D_s\to \tau \nus at the SPS proton target followed by the decay \nudecay in
the NOMAD detector. Both decays are expected to occur if \nus is a component
of .\
From the analysis of the data collected during the 1996-1998 runs with
protons on target, a single candidate event consistent with
background expectations was found. This allows to derive an upper limit on the
mixing strength between the heavy neutrino and the tau neutrino in the \nus
mass range from 10 to 190 . Windows between the SN1987a and Big Bang
Nucleosynthesis lower limits and our result are still open for future
experimental searches. The results obtained are used to constrain an
interpretation of the time anomaly observed in the KARMEN1 detector.\Comment: 20 pages, 7 figures, a few comments adde
Lower limit on the neutralino mass in the general MSSM
We discuss constraints on SUSY models with non-unified gaugino masses and R_P
conservation. We derive a lower bound on the neutralino mass combining the
direct limits from LEP, the indirect limits from gmuon, bsgamma, Bsmumu and the
relic density constraint from WMAP. The lightest neutralino (mneutralino=6GeV)
is found in models with a light pseudoscalar with MA<200GeV and a large value
for . Models with heavy pseudoscalars lead to mneutralino>18(29)GeV
for . We show that even a very conservative bound from the
muon anomalous magnetic moment can increase the lower bound on the neutralino
mass in models with mu<0 and/or large values of . We then examine
the potential of the Tevatron and the direct detection experiments to probe the
SUSY models with the lightest neutralinos allowed in the context of light
pseudoscalars with high . We also examine the potential of an e+e-
collider of 500GeV to produce SUSY particles in all models with neutralinos
lighter than the W. In contrast to the mSUGRA models, observation of at least
one sparticle is not always guaranteed.Comment: 37 pages, LateX, 16 figures, paper with higher resolution figures
available at
http://wwwlapp.in2p3.fr/~boudjema/papers/bound-lsp/bound-lsp.htm
Value chain transformation: Taking stock of WorldFish research on value chains and markets
The goal of WorldFish’s research on markets and value chains is to increase the benefits to resource-poor people from fisheries and aquaculture value chains by researching (1) key barriers to resource-poor men, women and other marginalized groups gaining greater benefits from participation in value chains, including barriers related to the availability, affordability and quality of nutrient-rich fish for resource-poor consumers; (2) interventions to overcome those barriers; and (3) mechanisms that are most effective for scaling up of value chain interventions. This paper aims to promote and document learning across WorldFish’s value chain research efforts in Asia and Africa. It has three main objectives: (1) to take stock of WorldFish’s past and ongoing research on value chains; (2) to draw out commonalities and differences between these projects; and (3) to provide a synthesis of some learning that can guide future work
Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up
Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated
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