Universidade Federal Rural do Rio de Janeiro

About: Universidade Federal Rural do Rio de Janeiro is a education organization based out in Seropédica, Brazil. It is known for research contribution in the topics: Population & Species richness. The organization has 6405 authors who have published 9852 publications receiving 105911 citations.

Calorific value of Prosopis africana and Balanites aegyptiaca wood: Relationships with tree growth, wood density and rainfall gradients in the West African Sahel

Abstract: Prosopis africana and Balanites aegyptiaca are native tree species in the West African Sahel and provide wood for fuel, construction and other essential products. A provenance/progeny test of each species was established at one relatively dry site in Niger, and evaluated at 13 years. Gross calorific value of the wood was determined for a random sample of trees in each test: gross CV and CVm 3 = gross calorific value in MJ kg −1 and MJ m −3 , respectively. The major objectives were to determine if gross CV was positively correlated with wood density and tree growth, and if gross CV and/or CVm 3 varied with rainfall gradients in the sample region. Provenances were grouped into a drier and more humid zone, and correlations were computed among all trees and separately in each zone. Results indicated that gross CV was not significantly correlated with density in either species. Gross CV was positively correlated with growth of P . africana (but not B . aegyptiaca ) only in the drier zone. Gross CVm 3 was positively correlated with growth of both species, and the correlations were stronger in the drier zone. Multiple regressions with provenance latitude, longitude and elevation indicated that provenance means for gross CV increased, in general, from the drier to the more humid zones. Regressions with gross CVm 3 were not significant. Results are compared with earlier research reports from the provenance/progeny tests and with other tropical hardwood species; and practical implications are presented for tree improvement and conservation programs in the region.

Study of the Stepwise Deprotonation Reactions of Glyphosate and the Corresponding pKa Values in Aqueous Solution

Abstract: Glyphosate (N-(phosphonomethyl)glycine) (Gph) is a herbicide that is broadly used in several countries. Its application to eliminate weeds may have the undesired effect of diminishing the metallic cations found in the soil (e.g., Ni2+ and Zn2+), due to a complexation reaction that depends on the soil’s pH. To better understand the molecular structures of glyphosate that are involved in such a complexation reaction, we have studied all possible glyphosate conformations in aqueous solution that may be involved in deprotonation reactions in the pH range from 2 to 11 using the polarizable continuum method (PCM). We have also compared direct (or absolute) methods to calculate pKa values, the cluster-continuum model and the proton-exchange scheme, using different thermodynamic cycles. The best result was achieved when using a proton-exchange scheme, which was able to properly reproduce three glyphosate experimental pKa values predicted for the glyphosate structures and conformations previously determined.

Flora vascular do Parque Estadual Carlos Botelho, São Paulo, Brasil

Abstract: Localizado na Serra de Paranapiacaba, sul do Estado de Sao Paulo, o Parque Estadual Carlos Botelho (PECB) abriga mais de 37.000 ha de Floresta Atlântica em um dos remanescentes mais importantes e extensos deste Bioma no Brasil. No Parque, predomina a Floresta Ombrofila Densa Montana e Submontana. Com o objetivo de organizar as informacoes floristicas disponiveis e direcionar futuros levantamentos, este estudo apresenta a lista de especies vasculares nativas das florestas do PECB. Alem de coletas pessoais dos autores, foram compilados mais de 3.900 registros citados desde 1967. Provindos de diferentes fontes de informacao, estes registros foram checados para verificar a presenca de sinonimias botânicas e novas combinacoes. Foi listado um total de 1.143 especies vasculares pertencentes a 140 familias e 528 generos (outras 63 especies nao foram incluidas por serem exoticas ou de ocorrencia/identificacao duvidosa). Houve grande riqueza de Myrtaceae, Orchidaceae, Fabaceae, Asteraceae, Melastomataceae, Lauraceae, Rubiaceae e Bromeliaceae. Apesar da alta riqueza de especies, a riqueza de ervas, epifitos e lianas esta certamente subestimada no Parque, de modo que futuros levantamentos certamente incluirao varias especies na lista apresentada aqui. Adicionalmente, foram encontradas mais de 60 especies com algum grau de ameaca de extincao, principalmente entre as familias Myrtaceae, Lauraceae e Gesneriaceae. Assim, os resultados encontrados colocam o PECB entre as unidades de conservacao com maior riqueza de especies no Estado de Sao Paulo, com grande importância nacional para a conservacao de especies de plantas.

COMMUNITY ECOLOGY OF THE METAZOAN PARASITES OF ATLANTIC MOONFISH, Selene setapinnis (OSTEICHTHYES: CARANGIDAE) FROM THE COASTAL ZONE OF THE STATE OF RIO DE JANEIRO, BRAZIL

Abstract: Eighty-nine specimens of Selene setapinnis (Mitchill, 1815) collected from the coastal zone of the State of Rio de Janeiro (21-23 degrees S, 41-45 degrees W and 23 degrees 05'S, 44 degrees 30'W), Brazil, from August 2001 to May 2002, were necropsied to study their metazoan parasites. Eighty-one (91%) specimens of S. setapinnis were parasitized by one or more metazoan species. Twenty-one species of parasites were collected: 8 digeneans, 3 monogeneans, 2 cestodes, 5 nematodes, and 3 copepods. The endoparasites (digeneans, cestodes, and nematodes) were 74.1% of total number of parasite specimens collected. The monogenean Pseudomazocraes selene (Hargis, 1957) was the most dominant species with the highest prevalence in the parasite community of S. setapinnis. The metazoan parasites of this host species showed the typical aggregated pattern of distribution. Only one parasite species (Acanthocolpoides pauloi Travassos, Freitas & Buhrnheim, 1955) showed positive correlation between the host total length and parasite abundance in S. setapinnis. Caligus robustus Bassett-Smith, 1898, P. selene, and Terranova sp. demonstrated positive correlation between the host total length and prevalence. Larvae of Terranova sp. showed influence of the host sex on its prevalence. A pair of ectoparasite species, P. selene-C. robustus, exhibited positive covariation between their abundances. Two pairs of endoparasite species, L. microstomum-P. merus and A. pauloi-P. merus showed significant covariation among their abundances; and the pair Terranova sp.-Raphidascaris sp. had positive co-ocorrence and covariation in the infracommunities of S. setapinnis. Like the parasite communities of the other carangid fishes from Rio de Janeiro, the parasite community of S. setapinnis is apparently only a slightly ordered species complex, characterized by dominance of endoparasite species.