Radiative environment inside a greenhouse

This paper reports a study on the solar and thermal radiative environment inside a plastic film cladded tunnel type greenhouse.In the day-time the net radiation is found to be strongly correlated to the incoming solar radiation, in analogy to what is known to occur over open ground. At night, a simple radiation budget model is effective in relating the net radiation to the radiometric properties and temperature of the surfaces which form the envelope of the greenhouse and the external (atmospheric and terrestrial) radiation fluxes.     

Assessment of maturity degree of composts from domestic solid wastes by fluorescence and Fourier transform infrared spectroscopies.

Methods of assessment of compost maturity are needed so the application of composted materials to lands will provide optimal benefits. The aim of the present paper is to assess the maturity reached by composts from domestic solid wastes (DSW) prepared under periodic and permanent aeration systems and sampled at different composting time, by means of excitation-emission matrix (EEM) fluorescence spectroscopy and Fourier transform infrared spectroscopy (FT-IR). EEM spectra indicated the presence of two different fluorophores centered, respectively, at Ex/Em wavelength pairs of 330/425 and 280/330 nm. The fluorescence intensities of these peaks were also analyzed, showing trends related to the maturity of composts. The "contour density" of EEM maps appeared to be strongly reduced with composting days. After 30 and 45 days of composting, FT-IR spectra exhibited a decrease of intensity of peaks assigned to polysaccharides and in the aliphatic region. EEM and FT-IR techniques seem to produce spectra that correlate with the degree of maturity of the compost. Further refinement of these techniques should provide a relatively rapid method of assessing the suitability of the compost to land application.     

Simple and inexpensive flow L-glutamate determination using pumpkin tissue

This work refers to a very easy to implementate flow injection system with potentiometric detection for l-glutamate determination in food samples. The proposed procedure is based on measurement of carbon dioxide produced by decarboxylation of l-glutamate catalyzed by l-glutamate decarboxylase (E.C. 4.1.1.1.5) from Cucurbita maxima (pumpkin). The FI potentiometric system includes an enzymatic reactor with a length of 8 cm and thickness of 5 mm packed with 200 mg of a C. maxima outer layer cut in to small pieces. The proposed procedure allowed l-glutamate determinations in the concentration interval of 10-100 mmol L(-1) for an injected sample volume of 50 microL. A phosphate buffer (0.1 mol L(-1), pH 5.5) solution flowing at 1.4 mL min(-1) was used as the carrier solution in the system. The results obtained in the analysis of food samples revealed a relative error lower than 5% when compared with those provided by the spectrophometric reference procedure. The immobilized reactor retained its initial activity for 21 days. It was possible to measure 40 samples/h with the flow system proposed.     

Indole acetic acid production by Rhizobium: Effect of 2-ketoglutaric acid

I ndole acetic acid (IAA) production from tryptophan by cell suspensions of Rhizobium trifolii, R. leguminosarum, R. phaseoli and R. lupini was studied in the presence or in the absence of 2-ketoglutaric acid. In R. lupini, production of IAA was strongly enhanced by the ketoacid, but in fast growing rhizobia it was less enhanced or unaffected. On the other hand, glutamic acid inhibits IAA production by R. meliloti, but stimulates IAA production in both R. leguminosarum and R. phaseoli. A hypothesis is proposed to explain these results.     

Effect of the conservation procedure on the contents of phenolic compounds and organic acids in chanterelle (Cantharellus cibarius) mushroom

To check the influence of the conservation procedure in the chemical composition of chanterelle mushroom, phenolic compounds and organic acids of samples preserved under four different conditions (drying, freezing, conservation in olive oil and in vinegar) were determined. Phenolics and organic acids were analyzed by HPLC-DAD and HPLC-UV, respectively. The results showed that chanterelle is characterized by the presence of six phenolic compounds (3-, 4-, and 5-O-caffeoylquinic acid, caffeic acid, p-coumaric acid, and rutin) and five organic acids (citric, ascorbic, malic, shikimic, and fumaric acids). Samples preserved in olive oil also exhibited hydroxytyrosol, tyrosol, luteolin, and apigenin, whereas conservation in vinegar led to the detection of hydroxytyrosol, tyrosol, and tartaric acid in the analyzed samples. The conservation procedures to which chanterelle samples were subjected seem to affect the qualitative and quantitative phenolics and organic acids profiles.     

Morphological Characterization of the Ovarian Preantral Follicle Population of Collared Peccaries (Tayassu tajacu Linnaeus, 1758)

The aim of this research was to characterize the preantral ovarian follicular population in collared peccaries (Tayassu tajacu) using light and electron microscopy. Ovaries from six mature females were collected and further fixed for histological and ultrastructural analysis. A total of 33273.45 ± 5789.99 preantral follicles (PFs) were estimated for the population in each ovary. Most preantral follicles were primordial (91.56%), followed by primary (6.29%) and secondary (2.15%) ones. Most PFs were morphologically normal (94.4%), and only a few were atretic (5.6%). At histology assessment, amounts of lipid droplets were observed into the oocyte cytoplasm, which was confirmed through ultrastructural analysis. This work characterizes for the first time the ovarian population of preantral follicles, total and per category, in collared peccaries (Tayassu tajacu). The general follicles featured at primordial, primary and secondary categories are very similar to those described for other species.     

Role of probiotics on the immunity of Nile tilapia Oreochromis niloticus: a review

The development and intensification of Nile tilapia farming systems has happened together with ever increased use of antibiotics and therapeutants. Research on the use of probiotics has come along as alternative to routine use of antibiotics in fish diets. The manipulation of the gut microbiota through dietary probiotic inclusion targeting improved growth rate and disease resistance has been investigated in many farmed fish species. However, mechanisms underlying modulation of fish immune response remains unclear. This review summarizes and discuss recent findings in the role of probiotics on the immunity of Nile tilapia Oreochromis niloticus addressing available information regarding immunological parameters such as phagocytic activity, lysozyme, respiratory burst activity, antioxidant enzymes, complement system as well as immune-related gene expression, in the aim to foster research efforts on effective strategies for the successful use of probiotics in the tilapia farming industry.

     

Prevalence of antibodies against Toxoplasma gondii among Brazilian white-eared opossums (Didelphis albiventris)

Considering that Toxoplasma gondii is a parasite of global importance which affects several animal species including humans, the current study aimed to investigate the prevalence of antibodies against T. gondii among 72 white-eared opossums (Didelphis albiventris) from Botucatu Municipality (22°53'S 48°26'W), S?o Paulo State, Brazil. The investigation was carried out from January 2008 to December 2009, when the animals had their blood samples collected and subjected to the modified agglutination test (MAT); 12 specimens had brain samples bioassayed in mice. Seroprevalence was 5.5% (n=4) and bioassays were negative. Older animals had higher prevalence of antibodies against T. gondii. Opossums in closer contact with the urban environment are likely more exposed to T. gondii than animals from the sylvatic environment.     

Uncoupling and inhibition properties of 3,4-seco-friedelan-3-oic acid isolated from Maytenus imbricata

3,4-Seco-friedelan-3-oic acid was isolated from Maytenus imbricata (Celastraceae). At low concentrations it inhibited non-cyclic electron transport and ATP synthesis in spinach chloroplasts, i.e., it behaved as a Hill reaction inhibitor, and at high concentrations it acts as an uncoupler by enhancing uncoupled electron transport and Mg²⁺-ATPase activity. 3,4-Seco-friedelan-3-oic acid did not inhibit PSII electron transport from DPC to DCPIP_ox and photosystem I activity, but it enhanced from TMQH₂ to MV, corroborating its action as uncoupler. It inhibits electron flow through PSII from water to sodium silicomolybdate. The whole results indicate that the 3,4-seco-friedelan-3-oic acid target is at the OEC complex enzyme, the donor side of PSII. The fluorescence decay data shows the formation of the K-band, which match this result, acting as inhibitor at the donor side of PSII and it as an uncoupler.