151 research outputs found

    Exercise in colon cancer modulation: an experimental approach

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    Carcinogenesis is a complex process best characterized as an accumulation of alterations in genes regulating cellular homeostasis. The whole process can be divided into three main stages: initiation, promotion, and progression. It has been observed that moderate and regular physical activity (PA) may prevent cancer, mainly colon cancer (CC), up to 50% in humans. The evidence that PA protects against colon cancer is convincing. Also, PA probably protects against postmenopausal breast cancer and cancer of the endometrium. On the other hand, exhaustive exercise increases free radical DNA oxidative damage, inflammation and depresses immune function, events also related to the increased risk for cancer development. Nevertheless, the mechanisms involved in both PA effects remain largely unknown and poorly studied. Understanding the mechanisms that link PA with cancer is useful to identify plausible mechanisms and associations between PA and cancer; to provide evidence for implementing interventions on clinical and public-health levels; to define exercise prescription for people without and with cancer; and to identify new clues to cancer biology, which might help in designing other cancer prevention and treatment modalities. Because of the complexity and heterogeneity of activity in people, animal models for carcinogenesis and PA present the opportunity to study the amounts and types of PA and biomarkers that influence carcinogenesis in controlled environments. Epithelial cell proliferation and aberrant crypt foci (ACF) have been used for early detection of factors that influence colorectal carcinogenesis in rats and can be induced by the colon carcinogen dimethyl-hydrazine (DMH). This interesting animal-tumor model is possible a useful approach for studying the influence of exercise during the initiation and post initiation period, and has already contributed to the current understanding of colon carcinogenesis and PA relationship

    On the Seismic Vulnerability Assessment of Urban Areas Using Census Data: The Lisbon Metropolitan Area as a Pilot Study Area

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    This paper presents a procedure for the application of an index-based vulnerability assessment method to the seismic risk assessment of 292,978 reinforced concrete and 152,916 unreinforced masonry buildings in the Lisbon Metropolitan Area (LMA). A singular innovation of this proposed methodology is that it is tailored to be fed with data from the 2011 national population and housing Census. The vulnerability results are then combined with the seismic hazard component into a GIS tool used to map seismic risk across the LMA. The spatial representation of these results highlights the areas of different levels of vulnerability and risk.info:eu-repo/semantics/publishedVersio

    Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

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    The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

    On the seismic vulnerability assessment of urban areas using census data: The Lisbon metropolitan area as a pilot study area

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    This paper presents a procedure for the application of an index-based vulnerability assessment method to the seismic risk assessment of 292,978 reinforced concrete and 152,916 unreinforced masonry buildings in the Lisbon Metropolitan Area (LMA). A singular innovation of this proposed methodology is that it is tailored to be fed with data from the 2011 national population and housing Census. The vulnerability results are then combined with the seismic hazard component into a GIS tool used to map seismic risk across the LMA. The spatial representation of these results highlights the areas of different levels of vulnerability and risk

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
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