Brazilian sedimentary zeolite use in agriculture.

Zeolites are hydrated crystalline aluminosilicate minerals of alkaline and alkaline earth metals, structured in rigid three dimension nets, organized by AlO4 and SiO4 tetrahedral and are of natural occurrence. This report describes the characterization and application of the Brazilian zeolitic sedimentary rock as a release fertilizer and soil conditioner. The characterization of the head samples showed that it is composed of the zeolite stilbite intermixed with a smectitic clay mineral, and quartz. A low-cost quartz separation technique was established. Enrichment of concentrated natural zeolite was carried out: zeolite + KNO3, zeolite + K2HPO4 and zeolite + H3PO4 + apatite and the concentrated zeolite. These materials were tested with Rangpur lime rootstock and an experiment was also carried out with successive crops grown on the same substrate: lettuce, tomato, rice, and Andropogon grass. The results indicated that N, P and K enriched zeolite was an adequate slow-release source of nutrients to plants. Other green house and field experiments with concentrated zeolite applied with urea showed reduction of losses of ammonia by volatilization and improved in N use efficiency by maize. Concentrated zeolite also increased water retention and the available water capacity of a sand soil

Killer lymphocytes use granulysin, perforin and granzymes to kill intracellular parasites

Protozoan infections are a serious global health problem1, 2. Natural killer (NK) cells and cytolytic T lymphocytes (CTLs) eliminate pathogen-infected cells by releasing cytolytic granule contents—granzyme (Gzm) proteases and the pore-forming perforin (PFN)—into the infected cell3. However, these cytotoxic molecules do not kill intracellular parasites. CD8+ CTLs protect against parasite infections in mice primarily by secreting interferon (IFN)-γ4, 5, 6, 7, 8, 9, 10. However, human, but not rodent, cytotoxic granules contain the antimicrobial peptide granulysin (GNLY), which selectively destroys cholesterol-poor microbial membranes11, 12, 13, 14, and GNLY, PFN and Gzms rapidly kill intracellular bacteria15. Here we show that GNLY delivers Gzms into three protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii and Leishmania major), in which the Gzms generate superoxide and inactivate oxidative defense enzymes to kill the parasite. PFN delivers GNLY and Gzms into infected cells, and GNLY then delivers Gzms to the intracellular parasites. Killer cell–mediated parasite death, which we term 'microbe-programmed cell death' or 'microptosis', is caspase independent but resembles mammalian apoptosis, causing mitochondrial swelling, transmembrane potential dissipation, membrane blebbing, phosphatidylserine exposure, DNA damage and chromatin condensation. GNLY-transgenic mice are protected against infection by T. cruzi and T. gondii, and survive infections that are lethal to wild-type mice. Thus, GNLY-, PFN- and Gzm-mediated elimination of intracellular protozoan parasites is an unappreciated immune defense mechanism

Qualidade de solo e água como indicadores de recuperação de áreas degradadas submetidas a manejo agroflorestal.

bitstream/CNPS-2010/14933/1/bpd100-2006-qual-solo-agua.pd

Desenvolvimento inicial de milho em função e doses de ureia aplicadas em semeadura.

A ureia é o fertilizante nitrogenado mais utilizado, contudo apresenta altas perdas de NH 3 pelo processo de volatilização. A fertilização com ureia no momento da semeadura pode comprometer a germinação, e, por conseguinte a população final da lavoura. Testaram -se três doses de ureia, calculadas com base na área superficial (AS), no volume do vaso (VV) e no número de plantas (NP), para a aplicação de 20 kg N ha-1.Asunidades experimentais foram vasos contendo 7 kg de solo, onde foram semeadas 6 sementes do híbrido AG 1051, sendo a adubação realizada ao lado e abaixo da linha de semeadura. A maior dose de ureia, obtida com base no numero de plantas, proporcionou menor germinação no terceiro dia após a semeadura, provavelmente devido a maior condutividade elétrica e maior volatilização de NH 3 a que foram submetidas às plantas deste tratamento

Prediction of Gravel Beach Storm Profiles Under Bimodal Sea-States

Presently our understanding of gravel beach response under wave attack is limited and approaches to predict gravel beach response rely on formulae and models based on a few physical modelling studies. Field and laboratory studies (Hawkes, Coates, and Jones (1998)) indicate the importance of complex wave spectra (combining swell and wind sea) in the design of gravel beach recharge schemes. The objective of the study was to develop a data-set and a new parametric model, Shingle-B, to analyse the generic profile response of shingle beaches under bimodal wave conditions in order to increase confidence in beach cross section design. A mobile bed flume study was therefore carried out at HR Wallingford. This paper describes both the design and the results of the 2D physical model study