Resposta de milho e soja à adubação fosfatada em latossolo amarelo muito argiloso de Paragominas - Pará.

FERTBIO 2006

Sistema Bragantino: modelo de agricultura em bases sustentáveis no Pará.

O sistema de agricultura utilizado no nordeste do Pará sempre foi o de derruba-e-queima que já dizimou a floresta primária antes existente. A atividade agrícola é exercida, por pequenos produtores com culturas anuais, sem calcário e fertilizantes, esgotando os nutrientes dos solos. Neste trabalho, o Sistema Bragantino foi testado para substituir o atual modelo utilizado, sendo instaladas nove UD's na região. Foram usados o milho, a mandioca e feijão-caupi, em rotação e consórcio. A adubação de fundação aumentou o P, Ca e Mg e diminuiu o Al e sua saturação no solo. As produtividades de milho e mandioca aumentaram e do caupi se manteve próximo da média regional. O rendimento médio da mandioca nas UD's foi 226,7% maior que a produtividade média do Estado do Pará. O Sistema Bragantino apresenta ainda outras vantagens, tais como: restaura a fertilidade do solo e possibilita o uso de áreas degradadas; elimina o uso do fogo e contribui para a preservação ambiental; permite o cultivo de até três culturas/ano, na mesma área, diminuindo os risco da atividade agrícola; aumenta a produtividade das culturas; aumenta a renda e melhora a qualidade de vida no campo; diminui os risco de erosão e de assoreamento dos cursos d?água, dentre outras

Sistema bragantino: alternativa inovadora para produção de alimentos em áreas degradadas na Amazônia.

O "Sistema Bragantino" é uma nova alternativa tecnológica de uso de áreas alteradas na Amazônia. A partir da recuperação da fertilidade dos solos pode-se substituir o sistema itinerante de derruba-e-queima, por um sistema de produção permanente, envolvendo o uso da rotação e do consórcio de culturas anuais, por meio da prática do plantio direto, a partir do segundo cultivo. Objetivando demonstrar suas vantagens foram implantadas, em áreas de produtores, "Unidades Demonstrativas" em vários municípios da região do Nordeste Paraense. Os resultados obtidos de produção de mandioca, milho e arroz foram considerados excelentes, alcançando produtividades médias de 226,7%, 537,4% e 430%, respectivamente, mais elevadas do que as obtidas com o sistema tradicional. Outro dado importante diz respeito à melhoria das características químicas do solo e das perspectivas de melhorias de vida dos produtores, permitindo afirmar que o "Sistema Bragantino" é uma tecnologia inovadora, prática e factível podendo substituir o sistema tradicional de derruba-e-queima, oferecendo vantagem não só nos aspectos produtivos, mas, também, nos sociais e ambientais

Sistema Bragantino: agricultura sustentável para a Amazônia.

Caracterização da região e dos sistemas de produção em uso. Sistema Bragantino. Considerações sobre as alternativas de rotação e consórcios. Etapas do trabalho. Sugestões de adubação e calagem para as culturas. Coeficientes técnicos.bitstream/item/25752/1/Doc218.pdfDisponível também on-line. 2ª impressão: 2009

Unsteady undular bores in fully nonlinear shallow-water theory

We consider unsteady undular bores for a pair of coupled equations of Boussinesq-type which contain the familiar fully nonlinear dissipationless shallow-water dynamics and the leading-order fully nonlinear dispersive terms. This system contains one horizontal space dimension and time and can be systematically derived from the full Euler equations for irrotational flows with a free surface using a standard long-wave asymptotic expansion. In this context the system was first derived by Su and Gardner. It coincides with the one-dimensional flat-bottom reduction of the Green-Naghdi system and, additionally, has recently found a number of fluid dynamics applications other than the present context of shallow-water gravity waves. We then use the Whitham modulation theory for a one-phase periodic travelling wave to obtain an asymptotic analytical description of an undular bore in the Su-Gardner system for a full range of "depth" ratios across the bore. The positions of the leading and trailing edges of the undular bore and the amplitude of the leading solitary wave of the bore are found as functions of this "depth ratio". The formation of a partial undular bore with a rapidly-varying finite-amplitude trailing wave front is predicted for ``depth ratios'' across the bore exceeding 1.43. The analytical results from the modulation theory are shown to be in excellent agreement with full numerical solutions for the development of an undular bore in the Su-Gardner system.Comment: Revised version accepted for publication in Phys. Fluids, 51 pages, 9 figure

Results and Outcome Reporting In ClinicalTrials.gov, What Makes it Happen?

At the end of the past century there were multiple concerns regarding lack of transparency in the conduct of clinical trials as well as some ethical and scientific issues affecting the trials' design and reporting. In 2000 ClinicalTrials.gov data repository was developed and deployed to serve public and scientific communities with valid data on clinical trials. Later in order to increase deposited data completeness and transparency of medical research a set of restrains had been imposed making the results deposition compulsory for multiple cases.We investigated efficiency of the results deposition and outcome reporting as well as what factors make positive impact on providing information of interest and what makes it more difficult, whether efficiency depends on what kind of institution was a trial sponsor. Data from the ClinicalTrials.gov repository has been classified based on what kind of institution a trial sponsor was. The odds ratio was calculated for results and outcome reporting by different sponsors' class.As of 01/01/2012 118,602 clinical trials data deposits were made to the depository. They came from 9068 different sources. 35344 (29.8%) of them are assigned as FDA regulated and 25151 (21.2%) as Section 801 controlled substances. Despite multiple regulatory requirements, only about 35% of trials had clinical study results deposited, the maximum 55.56% of trials with the results, was observed for trials completed in 2008.The most positive impact on depositing results, the imposed restrains made for hospitals and clinics. Health care companies showed much higher efficiency than other investigated classes both in higher fraction of trials with results and in providing at least one outcome for their trials. They also more often than others deposit results when it is not strictly required, particularly, in the case of non-interventional studies

Lipid-Induced Epigenomic Changes in Human Macrophages Identify a Coronary Artery Disease-Associated Variant that Regulates \u3cem\u3ePPAP2B\u3c/em\u3e Expression through Altered C/EBP-Beta Binding

Genome-wide association studies (GWAS) have identified over 40 loci that affect risk of coronary artery disease (CAD) and the causal mechanisms at the majority of loci are unknown. Recent studies have suggested that many causal GWAS variants influence disease through altered transcriptional regulation in disease-relevant cell types. We explored changes in transcriptional regulation during a key pathophysiological event in CAD, the environmental lipid-induced transformation of macrophages to lipid-laden foam cells. We used a combination of open chromatin mapping with formaldehyde-assisted isolation of regulatory elements (FAIRE-seq) and enhancer and transcription factor mapping using chromatin immuno-precipitation (ChIP-seq) in primary human macrophages before and after exposure to atherogenic oxidized low-density lipoprotein (oxLDL), with resultant foam cell formation. OxLDL-induced foam cell formation was associated with changes in a subset of open chromatin and active enhancer sites that strongly correlated with expression changes of nearby genes. OxLDL-regulated enhancers were enriched for several transcription factors including C/EBP-beta, which has no previously documented role in foam cell formation. OxLDL exposure up-regulated C/EBP-beta expression and increased genomic binding events, most prominently around genes involved in inflammatory response pathways. Variants at CAD-associated loci were significantly and specifically enriched in the subset of chromatin sites altered by oxLDL exposure, including rs72664324 in an oxLDL-induced enhancer at the PPAP2B locus. OxLDL increased C/EBP beta binding to this site and C/EBP beta binding and enhancer activity were stronger with the protective A allele of rs72664324. In addition, expression of the PPAP2B protein product LPP3 was present in foam cells in human atherosclerotic plaques and oxLDL exposure up-regulated LPP3 in macrophages resulting in increased degradation of pro-inflammatory mediators. Our results demonstrate a genetic mechanism contributing to CAD risk at the PPAP2B locus and highlight the value of studying epigenetic changes in disease processes involving pathogenic environmental stimuli