2-(2-methyl-2-nitrovinyl)furan but not furvina interfere with staphylococcus aureus agr quorum-sensing system and potentiate the action of fusidic acid against biofilms

Quorum sensing (QS) plays an essential role in the production of virulence factors, in biofilm formation and antimicrobial resistance. Consequently, inhibiting QS is being consid-ered a promising target for antipathogenic/anti-virulence therapies. This study aims to screen 2-nitrovinylfuran derivatives structurally related to Furvina (a broad-spectrum antibiotic already used for therapeutic purposes) for their effects on QS and in biofilm prevention/control. Furvina and four 2-nitrovinylfuran derivatives (compounds 1–4) were tested to assess the ability to interfere with QS of Staphylococcus aureus using bioreporter strains (S. aureus ALC1742 and ALC1743). The activity of Furvina and the most promising quorum-sensing inhibitor (QSI) was evaluated in biofilm prevention and in biofilm control (combined with fusidic acid). The biofilms were further characterized in terms of biofilm mass, viability and membrane integrity. Compound 2 caused the most significant QS inhibition with reductions between 60% and 80%. Molecular docking simulations indicate that this compound interacts preferentially with the protein hydrophobic cleft in the LytTR domain of AgrA pocket. Metabolic inactivations of 40% for S. aureus ALC1742 and 20% for S. aureus ALC1743 were reached. A 24 h-old biofilm formed in the presence of the QSI increased the metabolic inactivation by fusidic acid to 80%, for both strains. The overall results highlight the effects of compound 2 as well as the potential of combining QSI with in-use antibiotics for the management of skin and soft tissues infections

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Credit Constraints and Productive Entrepreneurship in Africa

Limited access of entrepreneurs to credit constrains the creation and growth of private firms. In Africa, access to credit is particularly limited for small and medium enterprises (SMEs) due to unclear property rights and the lack of assets that can be used as collateral. This paper presents a model where firm creation and growth hinge on matching potential entrepreneurs with productive technologies, while firm growth depends on acquired capital. The shortage of collateral creates a binding credit constraint on borrowing by SMEs and hence private sector growth and employment, even though the banking sectors have ample liquidity, as is the case in many African countries. The model is tested using a sample of 20 African countries over the period 2005-09. The empirical results suggest that policies aimed at easing the binding credit constraints (e.g., the depth of credit information and the strength of legal rights pertaining to collateral and bankruptcy) would stimulate productive entrepreneurship and private sector employment in Africa

O que significa ter uma criança com deficiência mental na família?

A família desempenha um papel preponderante no processo de inserção e adaptação da criança deficiente mental no contexto sociocultural. A literatura tem mostrado similaridades e diferenças não só quanto aos modos como as famílias se relacionam com sua criança com deficiência mental, mas também quando comparadas com famílias de crianças com desenvolvimento típico. Este artigo tem como objetivo descrever alguns aspectos do funcionamento de famílias de crianças com deficiência mental, comparando-os àqueles de famílias de crianças com desenvolvimento típico. Ênfase é dada às relações entre os diferentes subsistemas familiares: marido-esposa, genitores-criança e irmão-irmão, e suas implicações para o desenvolvimento infantil. Conhecer a dinâmica das relações de famílias de crianças com deficiência mental constitui o primeiro passo para a compreensão do desenvolvimento e dos mecanismos de adaptação dessas famílias às suas crianças. Mas, para compreender o funcionamento dessas famílias, é preciso levar em consideração as descobertas recentes da genética comportamental