Spectrophotometric Evaluation of the Behavior of Disperse Red 1 Dye in Aqueous Media and its Interaction with Calf Thymus ds-DNA

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DISTRIBUTION AND SEASONAL DYNAMICS OF RHODOPHYTA IN THE PRETO RIVER BASIN, SOUTHEASTERN BRAZIL

Distribution and seasonal dynamics of freshwater Rhodophyta were investigated in the Preto River basin, located in northwestern São Paulo State, southeastern Brazil. Twenty-two sites were sampled, six monthly during one year, four bimonthly during two years, and 12 twice (hot-rainy and cool-dry seasons) during the study period (May 1989 through March 1991). Red algal representatives were found in 19 sites (86.4%). Four species occurred in the basin with varying frequencies: Batrachospermum delicatulum (54.5%), Compsopogon coeruleus (36.4%), B. bicudoi (13.6%) and B. virgatum (4.5%). In addition, 'Chantransia' stage of the batrachospermalean species was found in 17 sites (77.3%). B. bicudoi, B. virgatum and C. coeruleus occurred only in large stream segments (greater-than-or-equal-to 3-order), generally in the main river, whereas B. delicatulum was more frequent in small streams (less-than-or-equal-to 3-order). The stream variables most closely related to the species distribution in the basin were specific conductance, pH and oxygen. B. bicudoi and B. delicatulum showed a marked seasonality: gametophytes were observed from late fall to early spring, while the 'Chantransia' stage generally occurred throughout the year. C. coeruleus was observed throughout the year in most sites, but the populations were generally more abundant from late fall to early spring. The combination of lower temperature and reduced turbidity resulting in increased illumination to the benthic algae during the dry winter months promotes the gametophytic growth of the batrachospermalean species, whereas current velocity was found to be the most influential stream variable for C. coeruleus. The persistance of the 'Chantransia' stage throughout the year as well as its tolerance to wider environmental conditions are key factors in the efficiency of the batrachospermalean life history strategy in lotic ecosystems.

Caracterización y clasificación de la red hidrográfica de la cuenca del río Bobo, departamento de Nariño - Colombia

The object of this work was to make a morphometric characterization of the Bobo river watershed in the Nariño department in Colombia. A map was created from topographical maps (1:25.000 scale) using the drainage network and the limit of each 2nd order microbasin as database. Dimensional, drainage network and relief morphometric parameters were evaluated for a later hy-drological study. The drainage area was 224.97 km2, having a 71.31 km perimeter. The Bobo river watershed is considered to be 6th order and has 176 2nd order drainage channels, 34 3rd order drainage channels, 9 4th order drainage channels and 3 5th order drainage channels. Average drainage density is 3.71km/km2, reflecting its high density, having strong, dissected geological formation. The area has a typical Andean land-use pattern, having native wooded vegetation, traditional transitory potato and vegetable growing predominating.

Genetic structure of red-handed howler monkey populations in the fragmented landscape of Eastern Brazilian Amazonia

We genotyped 15 microsatellite loci in order to evaluate the effects of habitat fragmentation, caused by flooding of the Tucuruí reservoir, on the genetic structure of Alouatta belzebul in eastern Amazonia. The analysis included two populations sampled in 1984, representing both margins of the Tocantins river, and three populations sampled 18 years later. Minimal differences in the diversity levels between present-day (Ho = 0.62-0.69 and AR = 6.07-7.21) and pre-flooding (Ho = 0.60-0.62 and AR = 6.27-6.77) populations indicated there was no significant loss of genetic variability, possibly because of successful management strategies applied during the flooding. The changes observed were limited to shifts in the composition of alleles, which presumably reflect the admixture of subpopulations during flooding. Given this, there were significant differences in the Rst values (p = 0.05) in all but one between-site comparison. Both present-day and original populations showed a deficit of heterozygotes, which suggests that this may be typical of the species, at least at a local level, perhaps because of specific ecological characteristics. The relatively large number of private alleles recorded in all populations may be a consequence of the Wahlund effect resulting from population admixture or a process of expansion rather than the loss of rare alleles through genetic drift. Additionally, the levels of genetic variability observed in this study were higher than those reported for other species of Neotropical primates, suggesting good fitness levels in these A. belzebul populations. Regular genetic monitoring of remnant populations, especially on islands, should nevertheless be an integral component of long-term management strategies.

Precolumbian land use and settlement pattern in the Santarém region, lower Amazon

Uma das áreas mais promissoras para o estudo das sociedades pré-colombianas complexas na bacia do rio Amazonas é a área do baixo curso dos rios Tapajós, Trombetas e Nhamundá. Há relatos escritos sobre os Konduri e os Tapajós, apresentando informações sobre a sua organização social regional, padrões de comércio, a abundância de alimentos, e o mundo material. Assim, evidências arqueológicas – sítios imensos, solos antrópicos, e belos artefatos – podem ser contrastadas com a informação escrita. Estes ricos depósitos culturais estão desaparecendo a um ritmo alarmante, à medida em que os centros urbanos crescem e se expande a agricultura na região. Apesar desta situação, pouca pesquisa arqueológica tem sido realizada na área, especialmente quando se trata de investigar os antigos padrões de assentamento e redes de trocas. Nos últimos anos, temos realizado pesquisas na bacia do baixo rio Tapajós. O registro arqueológico indica que a cerâmica mostrando forte semelhança estilística forte com a encontrada no grande sítio central está espalhada por pelo menos 90 quilômetros ao sul da presente cidade de Santarém. Este artigo apresenta os resultados de uma pesquisa regional realizada nas proximidades de Santarém, no planalto de Belterra e Alter do Chão, oferecendo uma análise preliminar do sistema de assentamentos na região.

Effect of tank colour on larval performance of the Amazon River prawn Macrobrachium amazonicum

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fire History at the Eastern Great Plains Margin, Missouri River Loess Hills

The purpose of this paper is to provide quantitative fire history information for a geographically unique region, the Loess Hills of northwest Missouri. We sampled 33 bur oak (Quercus macrocarpa Michx.), chinkapin oak (Q. muehlenbergii Engelm.), and black oak (Q. velutina Lam.) trees from the Brickyard Hill Conservation Area in northwest Missouri. The period of tree-ring record ranged in calendar years from 1671 to 2004 and fire-scar dates (n = 97) ranged from 1672 to 1980. Fire intervals for individual trees ranged from 1 to 87 years. The mean fire interval was 6.6 years for the pre-Euro-American settlement period (1672-1820), and 5.2 years for the entire record (1672-1980). A period of more frequent fire (mean fire interval = 1.6 for 1825 to 1850) coincided with Euro-American settlement of the area. The average percentage of trees scarred at the site was 16.8%, or about 1 in 7 trees sampled per fire. No significant relationship between fire years and drought conditions was found; however, events prior to 1820 may have been associated with wet to dry mode transitions.

Indicios de antecedencia en la red fluvial del sureste de Galicia

[ES] El presente trabajo ofrece un análisis preliminar de la red fluvial con antecedencia terciaria del sureste gallego. Las observaciones geomorfológicas de campo se centran en la cartografía de terrazas erosivas, canales abandonados, meandros colgados, codos de captura y redes anómalas. Para su interpretación se confrontaron con los thalwegs de los cursos principales y las fracturas alpinas cartografiadas por otros autores. Se propone una cronología para los procesos fluviales identificados; cronología que apunta una antigüedad de la red fluvial mayor a la estimada hasta el momento. De las siete tendencias identificadas, tres presentan una entidad regional (ENE-WSW, NE-SW, N-S), y cuatro local (NW-SE, SW-NE, SE-NW, S-N). Se confirma el carácter principal de la paleorred ENE-WSW (caracterizada por el río Sil) y como hipótesis se propone, para la Sierra de Queixa-San Mamede, el carácter de paleorrelieve positivo de herencia mesozoica. Este relieve habría sufrido varios procesos de levantamiento isostático y también tectónico durante la Orogenia Alpina. Estos levantamientos habrían provocado la superposición de capturas en las estribaciones surorientales de la Sierra de Queixa-San Mamede.

Sediment physicochemical properties condition pollutant association : a multivariate study of polybrominated diphenyl ethers on the Mendoza River irrigation areas

This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.

Performance data of the coral Pocillopora verrucosa and environmental conditions along the Saudi Arabian Red Sea coast as assessed during 3 expeditions in the years 2011 and 2012

Large scale patterns of ecologically relevant traits may help identify drivers of their variability and conditions beneficial or adverse to the expression of these traits. Antimicrofouling defenses in scleractinian corals regulate the establishment of the associated biofilm as well as the risks of infection. The Saudi Arabian Red Sea coast features a pronounced thermal and nutritional gradient including regions and seasons with potentially stressful conditions to corals. Assessing the patterns of antimicrofouling defenses across the Red Sea may hint at the susceptibility of corals to global change. We investigated microfouling pressure as well as the relative strength of 2 alternative antimicrofouling defenses (chemical antisettlement activity, mucus release) along the pronounced environmental gradient along the Saudi Arabian Red Sea coast in 2 successive years. Microfouling pressure was exceptionally low along most of the coast but sharply increased at the southernmost sites. Mucus release correlated with temperature. Chemical defense tended to anti-correlate with mucus release. As a result, the combined action of mucus release and chemical antimicrofouling defense seemed to warrant sufficient defense against microbes along the entire coast. In the future, however, we expect enhanced energetic strain on corals when warming and/or eutrophication lead to higher bacterial fouling pressure and a shift towards putatively more costly defense by mucus release.

Discarge compilation from The Global River Discharge (RivDIS) Project

The Global River Discharge (RivDIS) data set contains monthly discharge measurements for 1018 stations located throughout the world. The period of record varies widely from station to station, with a mean of 21.5 years. These data were digitized from published UNESCO archives by Charles Voromarty, Balaze Fekete, and B.A. Tucker of the Complex Systems Research Center (CSRC) at the University of New Hampshire. River discharge is typically measured through the use of a rating curve that relates local water level height to discharge. This rating curve is used to estimate discharge from the observed water level. The rating curves are periodically rechecked and recalibrated through on-site measurement of discharge and river stage.

Relationship between piezometric level and ground deformations measured by means of DInSAR in the Vega Media of the Segura River (Spain)

Differential SAR Interferometry (DInSAR) is a remote sensing method with the well demonstrated ability to monitor geological hazards like earthquakes, landslides and subsidence. Among all these hazards, subsidence involves the settlement of the ground surface affecting wide areas. Frequently, subsidence is induced by overexploitation of aquifers and constitutes a common problem that affects developed societies. The excessive pumping of underground water decreases the piezometric level in the subsoil and, as a consequence, increases the effective stresses with depth causing a consolidation of the soil column. This consolidation originates a settlement of ground surface that must be withstood by civil structures built on these areas. In this paper we make use of an advanced DInSAR approach - the Coherent Pixels Technique (CPT) [1] - to monitor subsidence induced by aquifer overexploitation in the Vega Media of the Segura River (SE Spain) from 1993 to the present. 28 ERS-1/2 scenes covering a time interval of about 10 years were used to study this phenomenon. The deformation map retrieved with CPT technique shows settlements of up to 80 mm at some points of the studied zone. These values agree with data obtained by means of borehole extensometers, but not with the distribution of damaged buildings, well points and basements, because the occurrence of damages also depends on the structural quality of the buildings and their foundations. The most interesting relationship observed is the one existing between piezometric changes, settlement evolution and local geology. Three main patterns of ground surface and piezometric level behaviour have been distinguished for the study zone during this period: 1) areas where deformation occurs while ground conditions remain altered (recent deformable sediments), 2) areas with no deformation (old and non-deformable materials), and 3) areas where ground deformation mimics piezometric level changes (expansive soils). The temporal relationship between deformation patterns and soil characteristics has been analysed in this work, showing a delay between them. Moreover, this technique has allowed the measurement of ground subsidence for a period (1993-1995) where no instrument information was available.