Antioxidant activities of Parquetina nigrescens

The antioxidant activities of different extracts (aqueous, methanol and flavonoid) of Parquetina nigrescens and butylated hydroxyl anisole, as reference compound, were evaluated in terms of scavenging effect, reducing power and inhibition of Fe2+/ascorbate-induced mitochondrial lipid peroxidation in rat liver. Extracts of P. nigrescens scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) generated radicals in the increasing order of flavonoid > methanol > aqueous > BHA at 1000 g/ml. The reducing power followed a similar trend as observed with scavenging activities. Extracts of P. nigrescens, at 50 mg/ml, exhibited significant (P < 0.05) inhibitory effects on  Fe2+/ascorbate-induced lipid peroxidation in rat liver mitochondria. These results showed that P. nigrescens contains antioxidants that could be useful in attenuating reactions which generate free radicals in the body.Key words: Parquetina nigrescens, antioxidant activities, lipid peroxidation

Antioxidant And Anti-Inflammatory Properties Of A Flavonoid Fraction From The Leaves Of Voacanga Africana

In this study we used several models for evaluation of probable anti-inflammatory and anti-nociceptive effects of the flavonoid fraction of the leaves of Voacanga Africana, using mice and rats. The extract (50 - 150mg/kg, p.o) inhibited, in a dose-related manner, carrageenan induced paw oedema in rats. The extract caused a significant inhibition of the cotton-pellet granuloma. Vascular permeability induced by acetic-acid in the peritoneum of the animals was equally inhibited. The extract also exhibited significant analgesic action in acetic acid- induced pain in mice. There was reduction of writhings induced by acetic acid. In the formalin test, the extract caused inhibition of the neurogenic (first phase) and inflammatory phase (second phase) of formalin-induced pain. The extract also produced anti-nociception in the animals, as assessed by the tail flick, hot-plate and limb-withdrawal tests. These findings suggest that the leaf extract of Voacanga Africana has potent anti-imfiammatory and anti-nociceptive action. Key words: Voacanga africana; anti-inflammatory and anti-nociceptive activities. Nigerian Journal of Physiological Sciences Vol.19(1&2) 2004: 69-7

Extraction of Knowledge Rules for the Retrieval of Mesoscale Oceanic Structures in Ocean Satellite Images

The processing of ocean satellite images has as goal the detection of phenomena related with ocean dynamics. In this context, Mesoscale Oceanic Structures (MOS) play an essential role. In this chapter we will present the tool developed in our group in order to extract knowledge rules for the retrieval of MOS in ocean satellite images. We will describe the implementation of the tool: the workflow associated with the tool, the user interface, the class structure, and the database of the tool. Additionally, the experimental results obtained with the tool in terms of fuzzy knowledge rules as well as labeled structures with these rules are shown. These results have been obtained with the tool analyzing chlorophyll and temperature images of the Canary Islands and North West African coast captured by the SeaWiFS and MODIS-Aqua sensors

Strong Ultraviolet Pulse From a Newborn Type Ia Supernova

Type Ia supernovae are destructive explosions of carbon oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious, One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations of strong but declining ultraviolet emission from a Type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some Type Ia supernovae arise from the single degenerate channel.Comment: Accepted for publication on the 21 May 2015 issue of Natur

ReCombine: A Suite of Programs for Detection and Analysis of Meiotic Recombination in Whole-Genome Datasets

In meiosis, the exchange of DNA between chromosomes by homologous recombination is a critical step that ensures proper chromosome segregation and increases genetic diversity. Products of recombination include reciprocal exchanges, known as crossovers, and non-reciprocal gene conversions or non-crossovers. The mechanisms underlying meiotic recombination remain elusive, largely because of the difficulty of analyzing large numbers of recombination events by traditional genetic methods. These traditional methods are increasingly being superseded by high-throughput techniques capable of surveying meiotic recombination on a genome-wide basis. Next-generation sequencing or microarray hybridization is used to genotype thousands of polymorphic markers in the progeny of hybrid yeast strains. New computational tools are needed to perform this genotyping and to find and analyze recombination events. We have developed a suite of programs, ReCombine, for using short sequence reads from next-generation sequencing experiments to genotype yeast meiotic progeny. Upon genotyping, the program CrossOver, a component of ReCombine, then detects recombination products and classifies them into categories based on the features found at each location and their distribution among the various chromatids. CrossOver is also capable of analyzing segregation data from microarray experiments or other sources. This package of programs is designed to allow even researchers without computational expertise to use high-throughput, whole-genome methods to study the molecular mechanisms of meiotic recombination

Seasonal climatic effects and feedbacks of anthropogenic heat release due to global energy consumption with CAM5

Anthropogenic heat release (AHR) is the heat generated in global energy consumption, which has not been considered in global climate models generally. The global high-resolution AHR from 1992 to 2013, which is estimated by using the Defense Meteorological Satellite Program (DMSP)/Operational Linescan System (OLS) satellite data, is implemented into the Community Atmosphere Model version 5 (CAM5). The seasonal climatic effects and possible feedbacks of AHR are examined in this study. The modeling results show that AHR increases the global annual mean surface temperature and land surface temperature by 0.02 ± 0.01 K (1σ uncertainty) and 0.05 ± 0.02 K (1σ uncertainty), respectively. The global climatic effect of AHR varies with season: with a stronger climatic effect in the boreal winter leading to global mean land surface temperature increases by 0.10 ± 0.01 K (1σ uncertainty). In the selected regions (40°N–60°N, 0°E–45°E) of Central and Western Europe the average surface temperature increases by 0.46 K in the boreal summer, and in the selected regions (45°N–75°N, 30°E–140°E) of northern Eurasia the average surface temperature increases by 0.83 K in the boreal winter. AHR changes the height and thermodynamic structure of the global planetary boundary layer, as well as the stability of the lower troposphere, which affects the global atmospheric circulation and low cloud fraction. In addition, at the surface both the shortwave radiation flux in the boreal summer and the down-welling longwave flux in the boreal winter change signifi- cantly, as a result of the change in low clouds caused by the effect of AHR. This study suggests a possible new mechanism of AHR effect on global climate through changing the global low-cloud fraction, which is crucial for global energy balance, by modifying the thermodynamic structure and stability of the lower troposphere. Thus this study improves our understanding of the global climate change caused by human activities

Antitumor activity of a small-molecule inhibitor of the histone kinase Haspin

The approval of histone deacetylase inhibitors for treatment of lymphoma subtypes has positioned histone modifications as potential targets for the development of new classes of anticancer drugs. Histones also undergo phosphorylation events, and Haspin is a protein kinase the only known target of which is phosphorylation of histone H3 at Thr3 residue (H3T3ph), which is necessary for mitosis progression. Mitotic kinases can be blocked by small drugs and several clinical trials are underway with these agents. As occurs with Aurora kinase inhibitors, Haspin might be an optimal candidate for the pharmacological development of these compounds. A high-throughput screening for Haspin inhibitors identified the CHR-6494 compound as being one promising such agent. We demonstrate that CHR-6494 reduces H3T3ph levels in a dose-dependent manner and causes a mitotic catastrophe characterized by metaphase misalignment, spindle abnormalities and centrosome amplification. From the cellular standpoint, the identified small-molecule Haspin inhibitor causes arrest in G2/M and subsequently apoptosis. Importantly, ex vivo assays also demonstrate its anti-angiogenetic features; in vivo, it shows antitumor potential in xenografted nude mice without any observed toxicity. Thus, CHR-6494 is a first-in-class Haspin inhibitor with a wide spectrum of anticancer effects that merits further preclinical research as a new member of the family of mitotic kinase inhibitors