Mineralogical and geochemical influences on sediment color of Amazon wetlands analyzed by visible spectrophotometry

Based on sedimentological and geochemical data, this work relates spectrophotometric measurements with sediment composition and its application in palaeoecological studies of Amazon wetlands. The CIELAB values are directly related to mineralogical and chemical composition, mostly involving quartz, iron oxyhydroxides and sulfides (e.g. pyrite), and total organic carbon. Total organic carbon contents between 0.4-1%, 1-2%, 3-5% and 15-40% were related to L* (lightness) data of 27, 26-15, 7-10 and 7 or less, respectively. The CIELAB values of a deposit in Marabá, Pará, were proportional to variations in quartz and total organic carbon contents, but changes in zones of similar color, mainly in the +a* (red) and +b* (yellow) values of deposits in Calçoene, Amapá and Soure, Pará, indicate a close relationship between total organic carbon content and iron oxyhydroxides and sulfides. Furthermore, the Q7/4 diagram (ratio between the % re?ectance value at 700 nm to that at 400 nm, coupled with L*) indicated iron-rich sediments in the bioturbated mud facies of the Amapá deposit, bioturbated mud and bioturbated sand facies of Soure deposit, and cross-laminated sand and massive sand facies of the Marabá core. Also, organic-rich sediments were found in the bioturbated mud facies of the Amapá deposit, lenticular heterolithic and bioturbated mud facies of the Soure deposit, and laminated mud and peat facies of the Marabá deposit. At the Marabá site, the data suggest an autochthonous influence with peat formation. The coastal wetland sites at Marajó and Amapá represent the development of a typical tidal flat setting with sulfide and iron oxyhydroxides formation during alternated flooding and drying.

The prevalence of human immunodeficiency virus type 1 and hepatitis C virus among injection drug users who use high risk inner-city locales in Miami, Florida

In order to estimate the prevalence of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) co-infection in hard-to-reach intravenous drug users, 199 subjects from high-risk inner-city locales, the so called "shooting galleries", were consented, interviewed, and tested in Miami, FL, US. Positive HIV-1 status was based on repeatedly reactive ELISA and confirmatory Western Blot. Positive HCV status was based on reactive ELISA and confirmatory polymerase chain reaction techniques. Overall, 50 (25%) were not infected with either virus, 61 (31%) were HIV-1/HCV co-infected, 17 (8%) infected by HIV-1 only, and 71 (36%) infected by HCV only. The results of the multivariable analyses showed that more years using heroin was the only significant risk factor for HCV only infection (odds ratio = 1.15; 95% confidence interval = 1.07, 1.24) and for HIV-1/HCV co-infection (odds ratio = 1.17; 95% confidence interval = 1.09, 1.26). This paper demonstrates that HIV-1/HCV co-infection is highly prevalent among so called "shooting galleries".

Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR). Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT) (n = 51) and by both techniques (n = 47). PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.

SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME

Veredas are humid tropical ecosystems, generally associated to hydromorphic soils and a shallow water table. The soils of these ecosystems are affected by the use of the areas around these veredas. The objective of this study was to determine soil organic matter (SOM) fractions in veredas adjacent to preserved (native savanna) and disturbed environments (agricultural areas and pastures) in the Cerrado biome. Soil samples were collected from the 0-10 and 10-20 cm layers along reference lines drawn along the relief following the upper, middle and lower positions of one of the slopes, in the direction of the draining line of the vereda. The soil analysis determined: total soil OC, total nitrogen and C:N ratio; C and N contents and C:N ratio in particulate and mineral-associated fractions (of SOM); fulvic acids, humic acids and humin fractions and ratio between humic and fulvic acids. The agricultural use around the veredas induced changes in the SOM fractions, more pronounced in the lower part of the slope. In the soil surface of this part, the OC levels in the humic substances and the particulate fraction of SOM, as well as total soil OC were reduced in the vereda next to crop fields.

Antioxidant compoundsand total antioxidant activity in fruits of acerola from cv. Flor Branca, Florida Sweet and BRS 366

Information on antioxidant properties at different ontological stages may help producers and food technologists to identify which cultivar and/or maturity stage are most adequate for their need, therefore this work aimed to study the changes in the antioxidant metabolism during acerola development. Fruit from cv. Flor Branca, BRS366 and Florida Sweet were harvested at different stages: immature green colored (I), physiologically mature with green color and maximum size (II), breaker (III) and full red ripe (IV). After harvest, fruits were selected, divided into four replications with 500 g each and evaluated regarding their titratable acidity, pH, soluble solids, total soluble sugar, vitamin C, polyphenol, anthocyanin, yellow flavonoid, total antioxidant activity and antioxidant enzyme activity. Anthocyanin and flavonoid were determined through LC-DAD-ESI/MS and all analysis followed a completely randomized factorial 3 x 4 design. Fruits of 'Florida Sweet' presented significantly higher soluble solids (9.46ºBrix). Vitamin C content decreased during ripening, but ripe 'BRS 366' fruits showed the greatest values (1363 mg.100 g-1) and highest TAA with 42.36 µM TEAC.g-1FW. Cyanidin 3-rhamnoside (520.76 mg.100 g-1 DM) and quercetin 3-rhamnoside (33.72 mg.100 g-1 DM) were the most abundant anthocyanin and yellow flavonoids found mainly in 'Flor Branca' fruit of acerola, whose antioxidant enzymes activities were also higher. Ripe 'Florida Sweet' fruit presents a great potential for fresh consumption, meanwhile physiologically mature 'BRS 366' fruit seems the best option for the bioactive compounds processing industry. As 'Flor Branca' fruit of acerola kept the highest activity levels, it could be an indicative of greater potential for postharvest conservation.

Citrus root distribution under water stress grown in sandy soil of central Florida

The experiment was conducted in an orchard located in University of Florida (Citrus Research and Education Center), Lake Alfred, Polk County, Florida, USA. The objective of this study was to evaluate the effects of water stress in root distribution of 'Valencia' orange tree on 'Swingle' citrumelo rootstock. Three treatments were imposed on the trees: 1) normal irrigation with microsprinklers, 2) no irrigation in winter (November through mid-March) and 3) rainfall exclusion by placing a water repelling fabric (Tyvek) under the trees. Trees in treatments 1 and 2 received normal rainfall during the winter, but treatment 3 received no rain. Normal irrigation was resumed on all treatments in mid March. Soil was collected using root auger head (0.09 m diameter and height 0.25 m) in two opposing quadrants (West and East at 3 horizontal distances from tree trunk (1, 2 and 3 m) and 4 depths (0.0-0.15; 0.15-0.30; 0.30-0.60 and 0.60-0.90 m). The results from root sampling showed that there was a significant difference in root distribution between irrigated treatment and non irrigated/non rainfall.