Crescimento de Bertholletia excelsa em floresta nativa no Mato Grosso.

Resumo

Produção de mudas de mamoneira (Ricinus communis L.) a partir da estimulação de estacas aéreas pelo Ácido 3-Indolacético (AIA) e pelo Ácido Indolbutírico (AIB).

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Above ground biomass functions with vegetation indices for multiple use systems of two evergreen oaks

Remote sensing is a promising approach for above ground biomass estimation, as forest parameters can be obtained indirectly. The analysis in space and time is quite straight forward due to the flexibility of the method to determine forest crown parameters with remote sensing. It can be used to evaluate and monitoring for example the development of a forest area in time and the impact of disturbances, such as silvicultural practices or deforestation. The vegetation indices, which condense data in a quantitative numeric manner, have been used to estimate several forest parameters, such as the volume, basal area and above ground biomass. The objective of this study was the development of allometric functions to estimate above ground biomass using vegetation indices as independent variables. The vegetation indices used were the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Simple Ratio (SR) and Soil-Adjusted Vegetation Index (SAVI). QuickBird satellite data, with 0.70 m of spatial resolution, was orthorectified, geometrically and atmospheric corrected, and the digital number were converted to top of atmosphere reflectance (ToA). Forest inventory data and published allometric functions at tree level were used to estimate above ground biomass per plot. Linear functions were fitted for the monospecies and multispecies stands of two evergreen oaks (Quercus suber and Quercus rotundifolia) in multiple use systems, montados. The allometric above ground biomass functions were fitted considering the mean and the median of each vegetation index per grid as independent variable. Species composition as a dummy variable was also considered as an independent variable. The linear functions with better performance are those with mean NDVI or mean SR as independent variable. Noteworthy is that the two better functions for monospecies cork oak stands have median NDVI or median SR as independent variable. When species composition dummy variables are included in the function (with stepwise regression) the best model has median NDVI as independent variable. The vegetation indices with the worse model performance were EVI and SAVI

Controle do alho-macho (Sisyrinchium platense Johnst): pesquisas realizadas na Embrapa Pecuária Sul.

Efeito do uso de calcário; Efeito de roçadasbitstream/item/67073/1/CR-22-2001.pd

Crescimento de Bertholletia excelsa em floresta natural em Juína, MT.

Resumo

Disposition of [U-2H7]glucose into hepatic glycogen in rat and in seabass

The stimulation of hepatic glycogenesis is a ubiquitous response to a glucose challenge and quantifying its contribution to glucose uptake informs its role in restoring euglycemia. Glycogenesis can be quantified with labeled water provided that exchange of glucose-6-phosphate hydrogen 2 (G6P-H2) and body water via glucose-6-phosphate isomerase, and exchange of positions 4, 5 and 6 hydrogens (G6P-H456) via transaldolase, are known. These exchanges were quantified in 24-h fasted rats (Rattus norvegicus; n=6) and 21-day fasted seabass (Dicentrarchus labrax; n = 8) by administration of a glucose load (2000 mg·kg−1) enriched with [U-2H7]glucose and by quantifying hepatic glycogen 2H-enrichments after 2 h (rats) and 48 h (seabass). Direct pathway contributions of the glucose load to glycogenesis were also estimated. G6P-H2 and body water exchange was 61 ± 1% for rat and 47 ± 3% for seabass. Transaldolase-mediated exchange of G6P-H456 was 5 ± 1% for rat and 10 ± 1% for seabass. Conversion of the glucose load to hepatic glycogen was significant in seabass (249 ± 54 mg·kg−1) but negligible in rats (12 ± 1 mg·kg−1). Preload plasma glucose levels were similar for seabass and rats (3.3 ± 0.7 and 4.4 ± 0.1 mmol·L−1, respectively) but post-load plasma glucose was significantly higher in seabass compared to rats (14.6 ± 1.8 versus 5.8 ± 0.3 mmol·L−1, p b 0.01). In conclusion, G6P-H2 and body water exchange is incomplete for both species and has to be accounted for in estimating hepatic glycogen synthesis and direct pathway activities with labeled water tracers. Transaldolase-mediated exchange is insignificant. Hepatic direct pathway glycogenesis plays a prominent role in seabass glucose load disposal, but a negligible role in the rat.The authors acknowledge the financial support from Fundação para a Ciência e a Tecnologia (FCT) in the form of a Ph.D. Fellowship to F.O.M.: SFRH/ BD/51194/2010, and Research Grants to J.G.J.: PTDC/EBB-BIO/ 098111/2008 & PTDC/SAU-MET/111398/2009. The NMR spectrometer is part of the National NMR Network and was purchased in the framework of the National Programme for Scientific re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and FCT

Knockout of insulin-degrading enzyme leads to mice testicular morphological changes and impaired sperm quality

Insulin-degrading enzyme (IDE) is a zinc metalloprotease responsible for degrading and inactivating several bioactive peptides, including insulin. Individuals without this enzyme or with a loss-of-function mutation in the gene that codifies it, present hyperinsulinemia. In addition, impairment of IDE-mediated insulin clearance is associated with the development of metabolic diseases, namely prediabetes. Although insulin regulates male fertility, the role of IDE on male reproductive function remains unknown. We proposed to study the influence of IDE in the reproductive potential of males. As insulin mediates key events for the normal occurrence of spermatogenesis, we hypothesized that IDE functioning might be linked with sperm quality. We used C57BL/6N mice that were divided in three groups according to its genotype: wild type (WT), heterozygous and knockout (KO) male mice for Ide. Spermatozoa were collected from the cauda of epididymis and sperm parameters were evaluated. Testicular tissue morphology was assessed through hematoxylin and eosin stain. Mitochondrial complex protein levels and lipid peroxidation were also evaluated in the testicular tissue. Our results show that KO mice present a 50% decrease in testes weight compared to WT mice as well as a decrease in seminiferous tubules diameter. Moreover, KO mice present impaired sperm quality, namely a decrease in both sperm viability and morphology. These results provide evidence that IDE plays an important role in determining the reproductive potential of males.publishe

A rapid and low-cost nonlithographic method to fabricate biomedical microdevices for blood flow analysis

Microfluidic devices are electrical/mechanical systems that offer the ability to work with minimal sample volumes, short reactions times, and have the possibility to perform massive parallel operations. An important application of microfluidics is blood rheology in microdevices, which has played a key role in recent developments of lab-on-chip devices for blood sampling and analysis. The most popular and traditional method to fabricate these types of devices is the polydimethylsiloxane (PDMS) soft lithography technique, which requires molds, usually produced by photolithography. Although the research results are extremely encouraging, the high costs and time involved in the production of molds by photolithography is currently slowing down the development cycle of these types of devices. Here we present a simple, rapid, and low-cost nonlithographic technique to create microfluidic systems for biomedical applications. The results demonstrate the ability of the proposed method to perform cell free layer (CFL) measurements and the formation of microbubbles in continuous blood flow.The authors acknowledge the financial support provided by PTDC/SAU-BEB/105650/2008, PTDC/SAU-ENB/116929/2010, EXPL/EMS-SIS/2215/2013 and scholarship SFRH/BD/89077/2012 and SFRH/BD/97658/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER).info:eu-repo/semantics/publishedVersio