994 research outputs found
The financial sustainability of Microcredit in Portugal
Microcredit and microfinance emerged in the 1970’s in Bangladesh and other developing countries and expanded rapidly worldwide as a business model financially sustainable and able to fight poverty and social exclusion. Empirical evidence confirms microcredit ability to mitigate poverty but its financial sustainability is controversial. Using 2006-2009 Portuguese micro-level data, we estimate the failure rate of Portuguese micro-credit projects as 20,6%/year that, to be financially sustainable, would require a real interest rate by 25%/year. Using a territorial variable on a discrete Cox proportional hazard model with censured data, we estimate that the failure rate of those micro-credit projects located in the worst-case NUTS II Portuguese regions (Alentejo and Centro) and promoted by lower schooling people is significantly higher than best-case.Microcredit, Firms failure rate, Poverty, Financial sustainability
The European Parliament as a driving force of constitutionalisation
Study for the AFCO CommiteeThis report analyses the increasing role played by the European Parliament (EP) in the EU decision-making process. In the first part (Sections 2, 3, 4 and 5), it describes how the EP acquired more power in legislation, comitology, in the appointment of the European Commission and in the budgetary field. In the second part (Sections 6 and 7), the report illustrates the EP’s role in two relevant policy fields: economic governance and external trade agreements. The report demonstrates that EP’s formal and informal powers in legislation, comitology, Commission investiture, the budgetary process, economic governance and international agreements have increased strikingly since the Treaty of Rome. This empowerment is partially explained by the concern for democratic legitimacy on the part of some member states’ (and the Commission). To another important part the empowerment may be explained by the fact that treaties frequently contain ambiguous provisions and thus allow room for informal rules to emerge through bargaining specifying the details of treaty provisions
The mechanism of formate oxidation by metal-dependent formate dehydrogenases
J Biol Inorg Chem (2011) 16:1255–1268 DOI 10.1007/s00775-011-0813-8Metal-dependent formate dehydrogenases
(Fdh) from prokaryotic organisms are members of the dimethyl sulfoxide reductase family of mononuclear molybdenum-containing and tungsten-containing enzymes.
Fdhs catalyze the oxidation of the formate anion to carbon dioxide in a redox reaction that involves the transfer of two electrons from the substrate to the active site. The active site in the oxidized state comprises a hexacoordinated molybdenum or tungsten ion in a distorted trigonal prismatic geometry. Using this structural model, we calculated
the catalytic mechanism of Fdh through density functional theory tools. The simulated mechanism was correlated with
the experimental kinetic properties of three different Fdhs isolated from three different Desulfovibrio species. Our studies indicate that the C–H bond break is an event involved in the rate-limiting step of the catalytic cycle. The role in catalysis of conserved amino acid residues involved in metal coordination and near the metal active site is discussed on the basis of experimental and theoretical results
Molybdenum Induces the expression of a protein containing a new heterometallic Mo-Fe cluster in desulfoVibrio alaskensis
Biochemistry. 2009 Feb 10;48(5):873-82. doi: 10.1021/bi801773t.The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.5 Da. The UV/visible absorption spectrum of the as-isolated protein shows absorption peaks around 280, 320, and 570 nm with extinction coefficients of 18700, 12800, and 5000 M(-1) cm(-1), respectively. Metal content, EXAFS data and DFT calculations support the presence of a Mo-2S-[2Fe-2S]-2S-Mo cluster never reported before. Analysis of the available genomes from Desulfovibrio species shows that the MorP encoding gene is located downstream of a sensor and a regulator gene. This type of gene arrangement, called two component system, is used by the cell to regulate diverse physiological processes in response to changes in environmental conditions. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 microM molybdenum. Involvement of this system in Mo tolerance of sulfate reducing bacteria is proposed
Yarrowia lipolytica growth under increased air pressure: influence on enzymes production
Improvement of microbial cell cultures oxygenation can be achieved by the
increase of total air pressure, which increases oxygen solubility in the medium. In this
work, a pressurized bioreactor was used for Yarrowia lipolytica batch cultivation under
increased air pressure from 1 to 6 bar. Cell growth was strongly enhanced by the pressure
rise. Fivefold and 3.4-fold increases in the biomass production and in specific growth rate,
respectively, were observed under 6 bar. The increase of oxygen availability caused the
induction of the antioxidant enzyme superoxide dismutase, which indicates that the
defensive mechanisms of the cells against oxidative stress were effective and cells could
cope with increased pressure. The pregrowth of Y. lipolytica under increased pressure
conditions did not affect the lipase production ability of the cells. Moreover, the
extracellular lipase activity increased 96% using a 5-bar air pressure instead of air at 1-
bar pressure during the enzyme production phase. Thus, air pressure increase in bioreactors
is an effective mean of cell mass and enzyme productivity enhancement in bioprocess based
in Y. lipolytica cultures
Comparison of Yarrowia lipolytica and Pichia pastoris cellular response to different agents of oxidative stress
Yeast cells exposed to adverse conditions employ a number of defense mechanisms in order to respond effectively to the stress effects of reactive oxygen species. In this work, the cellular response of Yarrowia lipolytica and Pichia pastoris to the exposure to the ROSinducing agents’ paraquat, hydrogen peroxide, and increased air pressure was analyzed. Yeast cells at exponential phase were exposed for 3 h to 1 mM paraquat, to 50 mM H2O2, or to increased air pressure of 3 or 5 bar. For both strains, the cellular viability loss and lipid peroxidation was lower for the cells exposed to increased air pressure than for those exposed to chemical oxidants. The glutathione induction occurred only in Y. lipolytica strain and reached the highest level as a response to PQ exposure. In general, antioxidant enzymes were more expressed in Y. lipolytica than in P. pastoris. The enzyme superoxide dismutase was induced in both strains under all the oxidant conditions but was dependent on the cellular growth phase, being undetectable in non-growing cells, whereas glutathione reductase was more induced in those conditions. Hydrogen peroxide was the most efficient inducer of catalase. Both yeast cultures underwent no cellular growth inhibition with increased air pressure, indicating that these yeast species were able to adapt to the oxidative stressful environment.The authors acknowledge the financial support provided by "Fundacao para a Ciencia e Tecnologia" (Grant SFRH/BD/47371/2008)
One More Piece in the VACV Ecological Puzzle: Could Peridomestic Rodents Be the Link between Wildlife and Bovine Vaccinia Outbreaks in Brazil?
BACKGROUND: Despite the fact that smallpox eradication was declared by the World Health Organization (WHO) in 1980, other poxviruses have emerged and re-emerged, with significant public health and economic impacts. Vaccinia virus (VACV), a poxvirus used during the WHO smallpox vaccination campaign, has been involved in zoonotic infections in Brazilian rural areas (Bovine Vaccinia outbreaks - BV), affecting dairy cattle and milkers. Little is known about VACV's natural hosts and its epidemiological and ecological characteristics. Although VACV was isolated and/or serologically detected in Brazilian wild animals, the link between wildlife and farms has not yet been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we describe for the first time, to our knowledge, the isolation of a VACV (Mariana virus - MARV) from a mouse during a BV outbreak. Genetic data, in association with biological assays, showed that this isolate was the same etiological agent causing exanthematic lesions observed in the cattle and human inhabitants of a particular BV-affected area. Phylogenetic analysis grouped MARV with other VACV isolated during BV outbreaks. CONCLUSION/SIGNIFICANCE: These data provide new biological and epidemiological information on VACV and lead to an interesting question: could peridomestic rodents be the link between wildlife and BV outbreaks
Bark anatomy, chemical composition and ethanol-water extract composition of Anadenanthera peregrina and Anadenanthera colubrina
The bark of Anadenanthera peregrina (L.) Speg and Anadenanthera colubrina (Vell.) Brenan
were characterized in relation to anatomical and chemical features. The barks were
similar and included a thin conducting phloem, a largely dilated and sclerified non-conducting
phloem, and a rhyridome with periderms with thin phellem interspersed by cortical tissues.
Only small differences between species were observed that cannot be used alone for
taxonomic purposes. The summative chemical composition of A. peregrina and A. colubrina
was respectively: 8.2% and 7.7% ash; 28.8% and 29.3% extractives; 2.4% and 2.6%
suberin; and 18.9% lignin. The monosaccharide composition showed the predominance of
glucose (on average 82% of total neutral sugars) and of xylose (9%). The ethanol-water
extracts of A. peregrina and A. colubrina barks included a high content of phenolics, respectively:
total phenolics 583 and 682 mg GAE/g extract; 148 and 445 mg CE/g extract; tannins
587 and 98 mg CE/g extract. The antioxidant activity was 238 and 269 mg Trolox/g extract.
The barks of the Anadenanthera species are a potential source of polar extractives that will
represent an important valorization and therefore contribute to improve the overall economic
potential and sustainability of A. peregrina and A. colubrinainfo:eu-repo/semantics/publishedVersio
“Quem ensina também aprende” : a formação pela prática de professores primários na província do Paraná
Resumo Segundo a historiografia da educação brasileira, muitas foram as ações relacionadas aos modos de formar professores primários durante o período imperial. Desses estudos, a maioria se centra na formação de professores atrelada à instituição das escolas normais, entretanto, há uma parcela menor de trabalhos que se propõem a discutir outro aspecto da formação de professores ao longo do século XIX, mais especificamente, a forma como sujeitos que não frequentaram esse espaço institucional (a escola normal), constituíram-se docentes primários. O artigo que aqui se apresenta partilha dessa perspectiva, e volta o olhar para os modos de formação pela prática de professores primários no Paraná na segunda metade do século XIX, por compreender que esse tipo de formação marcou um período em que a instrução pública estava se consolidando em meio a ações, deliberações, dificuldades e tensões, na tentativa de melhorias de sua condição. A pesquisa valeu-se da consulta da legislação educacional do período e de documentos advindos dos sujeitos envolvidos com a instrução pública, naquele momento, disponíveis no acervo do Arquivo Público do Paraná. No cotejamento e análise das fontes, é possível afirmar, que a formação pela prática dos professores primários na província do Paraná se deu no decorrer do desenvolvimento do processo de constituição do magistério primário
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