213 research outputs found
Adaptations of Avian Flu Virus Are a Cause for Concern
We are in the midst of a revolutionary period in the life sciences. Technological capabilities have dramatically expanded, we have a much improved understanding of the complex biology of selected microorganisms, and we have a much improved ability to manipulate microbial genomes. With this has come unprecedented potential for better control of infectious diseases and significant societal benefit. However, there is also a growing risk that the same science will be deliberately misused and that the consequences could be catastrophic. Efforts to describe or define life-sciences research of particular concern have focused on the possibility that knowledge or products derived from such research, or new technologies, could be directly misapplied with a sufficiently broad scope to affect national or global security. Research that might greatly enhance the harm caused by microbial pathogens has been of special concern (1â3). Until now, these efforts have suffered from a lack of specificity and a paucity of concrete examples of âdual use research of concernâ (3). Dual use is defined as research that could be used for good or bad purposes. We are now confronted by a potent, real-world example
Ligand-Induced Movements of Inner Transmembrane Helices of Glut1 Revealed by Chemical Cross-Linking of Di-Cysteine Mutants
The relative orientation and proximity of the pseudo-symmetrical inner transmembrane helical pairs 5/8 and 2/11 of Glut1 were analyzed by chemical cross-linking of di-cysteine mutants. Thirteen functional di-cysteine mutants were created from a C-less Glut1 reporter construct containing cysteine substitutions in helices 5 and 8 or helices 2 and 11. The mutants were expressed in Xenopus oocytes and the sensitivity of each mutant to intramolecular cross-linking by two homobifunctional thiol-specific reagents was ascertained by protease cleavage followed by immunoblot analysis. Five of 9 mutants with cysteine residues predicted to lie in close proximity to each other were susceptible to cross-linking by one or both reagents. None of 4 mutants with cysteine substitutions predicted to lie on opposite faces of their respective helices was susceptible to cross-linking. Additionally, the cross-linking of a di-cysteine pair (A70C/M420C, helices 2/11) predicted to lie near the exoplasmic face of the membrane was stimulated by ethylidene glucose, a non-transported glucose analog that preferentially binds to the exofacial substrate-binding site, suggesting that the binding of this ligand stimulates the closure of helices at the exoplasmic face of the membrane. In contrast, the cross-linking of a second di-cysteine pair (T158C/L325, helices 5/8), predicted to lie near the cytoplasmic face of the membrane, was stimulated by cytochalasin B, a glucose transport inhibitor that competitively inhibits substrate efflux, suggesting that this compound recruits the transporter to a conformational state in which closure of inner helices occurs at the cytoplasmic face of the membrane. This observation provides a structural explanation for the competitive inhibition of substrate efflux by cytochalasin B. These data indicate that the binding of competitive inhibitors of glucose efflux or influx induce occluded states in the transporter in which substrate is excluded from the exofacial or endofacial binding site
Tipificação de isolados deCurtobacterium flaccumfaciens pv. flaccumfaciens por bacteriocinas
Shifts in plant foliar and floral metabolomes in response to the suppression of the associated microbiota
Corporate philanthropic giving, advertising intensity, and industry competition level
This article examines whether the likelihood and amount of firm charitable giving in response to catastrophic events are related to firm advertising intensity, and whether industry competition level moderates this relationship. Using data on Chinese firms' philanthropic response to the 2008 Sichuan earthquake, we find that firm advertising intensity is positively associated with both the probability and the amount of corporate giving. The results also indicate that this positive advertising intensity-philanthropic giving relationship is stronger in competitive industries, and firms in competitive industries are more likely to donate. This study thus provides evidence suggesting that even in the wake of catastrophic events, corporate philanthropic giving is strategic.BusinessEthicsSSCI23ARTICLE139-529
Salinidade e temperatura na germinação e vigor de sementes de mutambo (Guazuma Ulmifolia Lam.) (Sterculiaceae)
Efeito da luz e de diferentes temperaturas na germinação de sementes de Heliocarpus popayanensis L
The Economies and Diseconomies of Industrial Clustering:Multinational Enterprises versus Uninational Enterprises
This studyâs objective is to compare cluster economies and diseconomies for multinational enterprises (MNEs) and uninational enterprises (UNEs) within the London financial services cluster. In contrast to the implicit assumption of the cluster participation literature that the economies and diseconomies of clusters are valued similarly by all firms, we find that economies relating to social capital and labour market pooling are equally important to MNEs and UNEs, economies relating to local competition and diseconomies relating to congestion costs are more important to MNEs than to UNEs, and economies relating to the reputational effects of locating in a world-leading cluster and access to specialised suppliers are more important to UNEs than to MNEs. That MNEs and UNEs do not experience cluster economies and diseconomies in the same way indicates that both cluster participation theory and international business theory need augmentation to recognise that cluster incumbents benefit and suffer from cluster membership differently
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