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.

Factors associated to Theileria equi in equids of two microregions from Rio de Janeiro, Brazil

Abstract: Serum samples from 714 equids of Itaguai and Serrana microregions, Rio de Janeiro, southeastern Brazil, were examined by indirect fluorescent antibody test (titer 1:80) for Theileria equi . The prevalence in the microregions and factors associated with seropositivity were evaluated and the prevalence ratio (PR) calculated. The overall prevalence of T. equi infection was 81.09% (n = 579), with higher prevalence (p < 0.05) in the Itaguai (85.43%) when compared to Serrana microregion (76.92%). The geographic area, altitude, farming condition and area of origin of equids were associated (p < 0.05) with seropositivity for T. equi. Equids reared in the Itaguai microregion (PR = 1.11, p = 0.003) and at altitudes below 500 m (PR = 1.10; p = 0,014) were more likely to be seropositive for T. equi. Furthermore, when equids were born in the farm (PR = 1.10, p = 0.008) and reared with poor farming conditions (PR = 1.13, p = 0.018) they were more likely to be exposed to T. equi. The main ticks found on equids were Amblyomma cajennense and Dermacentor (Anocentor) nitens. The microregions studied are endemic areas for equine theileriosis and there exists enzootic stability for T. equi. Only factors related to the collection area of serum samples influenced the seropositivity of equids for T. equi in that region.

Condutância estomática em milho em condições de deficiência de água e nitrogênio

Abstract: The objective of this work was to evaluate the effect of drought and nitrogen (N) stresses on stomatal conductance of three maize cultivars grown in the field. The stomatal conductance of Sol da Manha variety (BRS 4157) and Pioneer 6875 hybrid, under drought and high N, was lower than under drought and low N, which indicates drought tolerance, since these cultivars did not exhibit reduction in grain yield by drought, as observed for Amarelao variety, which flowered under more severe drought. 'Sol da Manha' exhibited shorter anthesis-silking interval under high N than under low N, an additional indication of tolerance.

In vitro efficacy of essential oils and extracts of Schinus molle L. against Ctenocephalides felis felis.

Abstract: Extracts and essential oils from plants are important natural sources of pesticides. These compounds are considered an alternative to control ectoparasites of veterinary importance. Schinus molle, an endemic species of Brazil, produces a high level of essential oil and several other compounds. The aim of this work was to determinate the chemical composition of extracts and essential oils of S. molle and further to evaluate the activity against eggs and adults of Ctenocephalides felis felis, a predominant flea that infests dogs and cats in Brazil. In an in vitro assay, the non-polar (n-hexane) extract showed 100% efficacy (800 µg cm(-2); LD50 = 524·80 µg cm(-2)) at 24 and 48 h. Its major compound was lupenone (50·25%). Essential oils from fruits and leaves were evaluated, and had 100% efficacy against adult fleas at 800 µg cm(-2) (LD50 = 353·95 µg cm(-2)) and at 50 µg cm(-2) (LD50 = 12·02 µg cm(-2)), respectively. On the other hand, the essential oil from fruits and leaves was not active against flea eggs. This is the first study that reports the insecticidal effects of essential oils and extracts obtained from Schinus molle against Ctenocephalides felis felis.

Triterpenes involved in the anti-inflammatory effect of ethanolic extract of Pterodon emarginatus Vogel stem bark

Abstract: Bioassay-guided fractionation of the ethanolic extract of Pterodon emarginatus Vogel stem bark (EtEx) resulted in the isolation and characterization of lupeol and betulin. Their structures were elucidated by spectroscopic methods including IR, (1)H-NMR, (13)C-NMR and comparison with literature values. This study showed the anti-inflammatory activity of EtEx, the hexane (HexL) and dichloromethane (DichL) layers, and lupeol and betulin. The extract, HexL, DichL, lupeol and betulin were able to inhibit acetic acid-induced writhing. In the formalin test, EtEx decreased licking time only in the second phase characterizing anti-inflammatory activity. In the oil-induced ear oedema test, EtEx, lupeol and betulin decrease edema formation. In conclusion, EtEx has antinociceptive effects arising from anti-inflammatory activity; this activity could be due to the presence of lupeol and betulin.