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Search Results: 1 - 10 of 194084 matches for " Carlos B; Greco "
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Ser planta en el desierto: estrategias de uso de agua y resistencia al estrés hídrico en el Monte Central de Argentina
Villagra,Pablo E; Giordano,Carla; Alvarez,Juan A; Bruno Cavagnaro,Juan; Guevara,Aranzazú; Sartor,Carmen; Passera,Carlos B; Greco,Silvina;
Ecolog?-a austral , 2011,
Abstract: the diversity and productivity of arid lands depend on the interaction between environmental limitations and the complex of adaptive features that allow organisms to maintain their water and energy balance. the central monte is located in the aridsemiarid zone from western argentina, with mean annual rainfall that varies between 30 and 350 mm, concentrated in summer, mean temperature between 13 and 18 oc and with water deficit during most of the year. here we analyze plant adaptations to water stress and the water use strategies of the dominant life forms in central monte: trees, shrubs and perennial grasses. trees and shrubs from the monte include species with different levels of xerophytism. their adaptations range from exploitation of deep water reservoirs with extensive root systems to a wide variety of physiological, morphological and architectural strategies to tolerate drought and salinity. prosopis flexuosa, a phreatophytic tree, plays central ecological roles in plant communities, affects the hydrological cycle, and is an important economical resource locally and regionally. grasses, with shallow root systems, have growth pulses associated to rainfall dynamics. diversity in water use by the dominant plant growth forms determines negative and positive interactions among species that modulate the ecosystem productivity and, consequently, its productive potential. the hydrological cycle is strongly linked to vegetation (and viceversa) in the monte ecosystems, both locally and regionally (in several areas with groundwater accessible to plant roots, recharged by andean precipitations). therefore, the knowledge of the mechanism driving this connections helps to understand ecosystem functioning and to predict future scenarios in relation to global climate change and land use.
A epidemia da Aids: impacto social, científico, econ?mico e perspectivas
Greco, Dirceu B.;
Estudos Avan?ados , 2008, DOI: 10.1590/S0103-40142008000300006
Abstract: the emergence of the aids epidemic and the increase in the incidence of hiv infection are still a health challenge for the 21st century. the way the epidemic is being confronted and how it will be in the years to come will be of fundamental importance on the discussion of public health, ethics and human rights. the diverse aspects of the epidemic are here discussed, including the possible interventions necessary to its control. changes in the decision-making process for the allocation of resources, both for public health care and research, as well the expansion of the ethical debate and the need to improve the standard of living of all individuals, are imperative conditions in order to face this very serious public health problem.
Editorial Especial: as modifica es propostas para o parágrafo 30 da Declara o de Helsinque 2000 diminuir o os requisitos relacionados ao acesso aos cuidados de saúde para os voluntários de ensaios clínicos Special Editorial: the proposed changes for Paragraph 30 of the Declaration of Helsinki 2000 will reduce requirements relative to healthcare access for clinical trial volunteers
Dirceu B. Greco
Revista Brasileira de Epidemiologia , 2003, DOI: 10.1590/s1415-790x2003000400002
Analytical solutions for geometrically nonlinear trusses
Greco, Marcelo;Vicente, Carlos Eduardo Rodrigues;
Rem: Revista Escola de Minas , 2009, DOI: 10.1590/S0370-44672009000200012
Abstract: this paper presents an analytical method for analyzing trusses with severe geometrically nonlinear behavior. the main objective is to find analytical solutions for trusses with different axial forces in the bars. the methodology is based on truss kinematics, elastic constitutive laws and equilibrium of nodal forces. the proposed formulation can be applied to hyper elastic materials, such as rubber and elastic foams. a von mises truss with two bars made by different materials is analyzed to show the accuracy of this methodology.
Novel aminonaphthoquinone mannich bases derived from lawsone and their copper(II) complexes: synthesis, characterization and antibacterial activity
Neves, Amanda P.;Barbosa, Cláudia C.;Greco, Sandro J.;Vargas, Maria D.;Visentin, Lorenzo C.;Pinheiro, Carlos B.;Mangrich, Ant?nio S.;Barbosa, Jussara P.;Costa, Gisela L. da;
Journal of the Brazilian Chemical Society , 2009, DOI: 10.1590/S0103-50532009000400015
Abstract: a series of novel mannich bases (hl1-hl13) derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes [c6h2r1r2r3c(o)h] and various primary amines (nh2r4, r4 = n-butyl, benzyl, allyl, 2-furfuryl), and their cu2+ complexes, [cu(l1)2]-[cu(l13)2], have been synthesized and fully characterized by analytical and spectroscopic methods. the structures of complexes 1(r1 = r2 = r3 = h; r4 = bu), 2(r1 = r3 = h; r2 = no2; r4= bu) and 7 (r1 = oh; r2 = r3 = h; r4= bu) were determined by single crystal x-ray diffraction studies. all complexes crystallize in centrosymmetric space groups, with a copper atom in the inversion centre. two l- coordinate through the naphthalen-2-olate oxygen and secondary amine-n atoms, forming six-membered chelate rings around the copper atom in a trans-n2o2 environment; spectroscopic data confirm that the other complexes exhibit similar molecular arrangement. the antimicrobial activity of all compounds has been tested on seven different strains of bacteria: bacillus cereus, bacillus subtilis, escherichia coli, enterococcus faecalis, klebsiella pneumoniae, pseudomonas aeruginosaand staphylococcus aureus. in general, mannich bases were more active than complexes, hl11(r1 = oh; r2 =h; r3 = me; r4= bn) and hl13(r1 = oh; r2 = h; r3 = br; r4= bn) being the most potent inhibitors. the mic for the most active compound hl11against s. coliwas 20 μmol l-1 (8 μg ml-1), better than chloramphenicol (90 μmol l-1) and well below most values reported for other naphthoquinones.
Dinamica da institucionaliza??o de idosos em Belo Horizonte, Brasil
Chaimowicz,Flávio; Greco,Dirceu B;
Revista de Saúde Pública , 1999, DOI: 10.1590/S0034-89101999000500004
Abstract: introduction: epidemiological and social changes related to population aging in brazil will probably increase the need for nursing homes (nh). the study analyses the dynamics of institutionalization in belo horizonte, a 3 million inhabitant city of whom 8.0% are aged 60 or more. methods: age and length of stay of 1,128 nh residents (92.5% of the estimated population) was registered and occupancy and institutionalization rates were determined. results: among women aged 65+ in belo horizonte, 0.88% were living in nh; among men, 0.26%. occupancy rates were 92%. women (81%) were older than men (76.4 x 70.4 years; two-tailed t test = 6.4; p=0.00) and lived there for a longer period (5.6 x 4.5 years; two-tailed t test = 2.6; p=0.01). almost 1/3 of the men were aged < 65. conclusions: high occupancy rates, long waiting lists and hard criteria for admission (half reject demented or dependent individuals) insinuates that these low institutionalization rates are related to scarcity of beds. the preponderance of women reflects the proportion of those widowed or separated in the community (66% of those aged 65-+, versus 76% of married man). the high frequency of institutionalized men aged <65 suggests lower capacity of maintaining themselves after widowhood. high death rates (24% during a 20 month follow-up of a 263 random sample) determines the small median length of stay (3 years). these data unveil the anachronism of a system which is not directed towards the maintenance of the brazilian older people among their families and homes.
Dinamica da institucionaliza o de idosos em Belo Horizonte, Brasil
Chaimowicz Flávio,Greco Dirceu B
Revista de Saúde Pública , 1999,
Abstract: OBJETIVO: O processo de envelhecimento populacional brasileiro tem sido acompanhado por transforma es epidemiológicas e sociais que, em outros países, aumentaram a demanda por institui es de longa permanência. Nesse sentido, desenvolveu-se estudo sobre dinamica da institucionaliza o de idosos através da análise da oferta de leitos e características demográficas dos residentes em asilos. MéTODOS: Foi realizado levantamento dos asilos de idosos do Município de Belo Horizonte, MG. Foram registradas datas de nascimento e admiss o de 1.128 residentes de 33 dos 40 asilos em funcionamento no município. A lota o foi calculada através da capacidade informada e da taxa de institucionaliza o, segundo dados da Pesquisa Nacional por Amostra de Domicílios (PNAD). RESULTADOS: As taxas de institucionaliza o de idosos (65+) do município foram 0,9% (mulheres) e 0,3% (homens). A lota o mediana dos asilos era de 92%. Dentre os 1.128 residentes arrolados (92,5% do total), as mulheres (81%) apresentavam maiores médias de idade (76,4 x 70,4 anos; p=0,00) e estada (5,6 x 4,5 anos; p=0,01). DISCUSS O/CONCLUS ES: Elevada lota o, listas de espera nos asilos filantrópicos (85% do total) e rígidos critérios para admiss o (metade recusava idosos demenciados ou dependentes) sugerem que a baixa taxa de institucionaliza o se deve à escassez de vagas. A predominancia de idosas reflete a prevalência de viúvas ou separadas na comunidade (66% contra 76% de homens casados). A propor o de homens adultos (31% < 65 anos) sugere dificuldade de se auto-sustentarem após a viuvez. Elevada taxa de mortalidade (24% durante 20 meses de acompanhamento de amostra aleatória de 263 residentes), incompatível com o rigor dos critérios de admiss o, determina a baixa mediana de estada (3 anos). Os dados refletem o anacronismo de um sistema n o direcionado à manuten o dos idosos em seus próprios domicílios.
Accidental tetanus: prognosis evaluation in a historical series at a hospital in Salvador, Bahia, Brazil
Greco, Jiuseppe B.;Tavares-Neto, José;Greco Júnior, Jiuseppe B.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2003, DOI: 10.1590/S0036-46652003000100007
Abstract: a total of 868 (84.89%) patients diagnosed with tetanus were studied, out of the 1,024 tetanus patients hospitalized at couto maia hospital (salvador, bahia, brazil), during the period between 1986 and 1997. of this group (n = 868), 63.5% (n = 551) were discharged, 35.4% (n = 307) died, and 1.1% (n = 10) were transferred. the average age of the deceased patients (38.73 ± 23.31 years) was significantly greater (p < 0.0001) than the age of those who survived (29.21 ± 20.05 years). analyzing the variables of the logistic regression model with statistic significance (p £ 0.25) for univariate analysis, we observed a greater association of risk for worst prognosis (death) in patients aged 3 51 years; time of illness < 48 hours; time of incubation < 168 hours; neck rigidity; spasms; opisthotonos; body temperature 3 37.7 oc; heart beat 3 111 beats/minute; sympathetic hyperactivity and association with pneumonia. among the group of those who survived, patients with 1 to 5 of those variables (n = 398; 76.8%) were more frequent, while among patients of the group of the deceased, 70.3% (n = 206) presented 6 to 10 of those variables, with a highly significant difference (p < 10-8). in conclusion, the indicators described provide early information that may guide the prognosis and medical and nurse care.
Accidental tetanus: prognosis evaluation in a historical series at a hospital in Salvador, Bahia, Brazil
Greco Jiuseppe B.,Tavares-Neto José,Greco Júnior Jiuseppe B.
Revista do Instituto de Medicina Tropical de S?o Paulo , 2003,
On two methods to estimate production of Eichhornia crassipes in the eutrophic Pampulha reservoir (MG, Brazil)
GRECO, M. K. B.;FREITAS, J. R. de;
Brazilian Journal of Biology , 2002, DOI: 10.1590/S1519-69842002000300010
Abstract: this paper deals with variations in biomass and in the production of eichhornia crassipes (water hyacinth) in a eutrophic tropical reservoir. net production was assessed by both a traditional method and a demographic approach. the initial biomass ranges from 96 g dw.m-2 to a maximum of 2027 g dw.m-2. net production estimates varied greatly according to which method was used to calculate them (traditional: 20.6 ton dw.hectare-1.year-1, demographic: 226.9 ton dw.year-1).
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