463 research outputs found
Feux de forêts. Bilan de la campagne 1987
Décrit les mesures de prévention et d'information du public, les actions d'équipement du terrain, les opérations de surveillance et de lutte
A dimensão do cuidar no trabalho hospitalar: abordagem psicodinâmica do trabalho de enfermagem e dos serviços de manutenção
Formation and Recognition of UV-Induced DNA Damage within Genome Complexity
Ultraviolet (UV) light is a natural genotoxic agent leading to the formation of photolesions endangering the genomic integrity and thereby the survival of living organisms. To prevent the mutagenetic effect of UV, several specific DNA repair mechanisms are mobilized to accurately maintain genome integrity at photodamaged sites within the complexity of genome structures. However, a fundamental gap remains to be filled in the identification and characterization of factors at the nexus of UV-induced DNA damage, DNA repair, and epigenetics. This review brings together the impact of the epigenomic context on the susceptibility of genomic regions to form photodamage and focuses on the mechanisms of photolesions recognition through the different DNA repair pathways
EP-1245: Gated Rapidarc using KV intrafraction verification for liver stereotactic treatment
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Hydro-climatic and ecological behaviour of the drought of Amazonia in 2005
In 2005, southwestern Amazonia experienced the effects of an intense drought that affected life and biodiversity. Several major tributaries as well as parts of the main river itself contained only a fraction of their normal volumes of water, and lakes were drying up. The consequences for local people, animals and the forest itself are impossible to estimate now, but they are likely to be serious. The analyses indicate that the drought was manifested as weak peak river season during autumn to winter as a consequence of a weak summertime season in southwestern Amazonia; the winter season was also accompanied by rainfall that sometimes reached 25% of the climatic value, being anomalously warm and dry and helping in the propagation of fires. Analyses of climatic and hydrological records in Amazonia suggest a broad consensus that the 2005 drought was linked not to El Niño as with most previous droughts in the Amazon, but to warming sea surface temperatures in the tropical North Atlantic Ocean
Protein crystals in adenovirus type 5-infected cells: requirements for intranuclear crystallogenesis, structural and functional analysis
Intranuclear crystalline inclusions have been observed in the nucleus of epithelial cells infected with Adenovirus serotype 5 (Ad5) at late steps of the virus life cycle. Using immuno-electron microscopy and confocal microscopy of cells infected with various Ad5 recombinants modified in their penton base or fiber domains, we found that these inclusions represented crystals of penton capsomers, the heteromeric capsid protein formed of penton base and fiber subunits. The occurrence of protein crystals within the nucleus of infected cells required the integrity of the fiber knob and part of the shaft domain. In the knob domain, the region overlapping residues 489–492 in the FG loop was found to be essential for crystal formation. In the shaft, a large deletion of repeats 4 to 16 had no detrimental effect on crystal inclusions, whereas deletion of repeats 8 to 21 abolished crystal formation without altering the level of fiber protein expression. This suggested a crucial role of the five penultimate repeats in the crystallisation process. Chimeric pentons made of Ad5 penton base and fiber domains from different serotypes were analyzed with respect to crystal formation. No crystal was found when fiber consisted of shaft (S) from Ad5 and knob (K) from Ad3 (heterotypic S5-K3 fiber), but occurred with homotypic S3K3 fiber. However, less regular crystals were observed with homotypic S35-K35 fiber. TB5, a monoclonal antibody directed against the Ad5 fiber knob was found by immunofluorescence microscopy to react with high efficiency with the intranuclear protein crystals in situ. Data obtained with Ad fiber mutants indicated that the absence of crystalline inclusions correlated with a lower infectivity and/or lower yields of virus progeny, suggesting that the protein crystals might be involved in virion assembly. Thus, we propose that TB5 staining of Ad-infected 293 cells can be used as a prognostic assay for the viability and productivity of fiber-modified Ad5 vectors
Subtypes of Acute Ischemic Stroke
Background: To determine the frequency ofvarious subtypes of acute ischemic stroke amongpatients using the TOAST criteria.Methods: In this prospective, cross sectional study156 consecutive stroke patients fulfilling theinclusion criteria were recruited. Information on riskfactors like age, gender, diabetes and hypertensionwas collected. Physical and neurologicalexamination was done and relevant investigationswere reviewed, to classify the subtype of strokeaccording to TOAST criteria. . Risk factors like age,gender, diabetes and hypertension were comparedwith stroke subtypes after stratification using thechi-square test with significance at p < 0.05.Results: Out of the 156 patients with acute ischemicstroke, mean age at presentation was 63.51 years.Among them 75% had hypertension and 48.1% werediabetics. The various subtypes of acute ischemicstroke were Large artery atherosclerosis(35.3%)whichwas the commonest cause. Large arteryatherosclerosis was found to be more common infemales (47.1% vs 25.6%) whereas cardioembolicstrokes were more common in males (29.1% vs17.1%) (p value 0.02). When hypertension anddiabetes was compared with stroke subtypes theresults were statistically insignificant (p value.>0.05).Conclusion: Higher incidence of large artery andcardioembolic disease was found. Preventive effortsagainst the burden of ischemic stroke should focuson risk factor intervention for each patient accordingto subtype rather than ischemic stroke as a whole
Transgenerational Stress Memory Is Not a General Response in Arabidopsis
Adverse conditions can trigger DNA damage as well as DNA repair responses in plants. A variety of stress factors are known to stimulate homologous recombination, the most accurate repair pathway, by increasing the concentration of necessary enzymatic components and the frequency of events. This effect has been reported to last into subsequent generations not exposed to the stress. To establish a basis for a genetic analysis of this transgenerational stress memory, a broad range of treatments was tested for quantitative effects on homologous recombination in the progeny. Several Arabidopsis lines, transgenic for well-established recombination traps, were exposed to 10 different physical and chemical stress treatments, and scored for the number of somatic homologous recombination (SHR) events in the treated generation as well as in the two subsequent generations that were not treated. These numbers were related to the expression level of genes involved in homologous recombination and repair. SHR was enhanced after the majority of treatments, confirming previous data and adding new effective stress types, especially interference with chromatin. Compounds that directly modify DNA stimulated SHR to values exceeding previously described induction rates, concomitant with an induction of genes involved in SHR. In spite of the significant stimulation in the stressed generations, the two subsequent non-treated generations only showed a low and stochastic increase in SHR that did not correlate with the degree of stimulation in the parental plants. Transcripts coding for SHR enzymes generally returned to pre-treatment levels in the progeny. Thus, transgenerational effects on SHR frequency are not a general response to abiotic stress in Arabidopsis and may require special conditions
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