On the α−\alpha-decay of deformed actinide nuclei

$\alpha-$decay through a deformed potential barrier produces significant mixing of angular momenta when mapped from the nuclear interior to the outside. Using experimental branching ratios and either semi-classical or coupled-channels transmission matrices, we have found that there is a set of internal amplitudes which are essentially constant for all even--even actinide nuclei. These same amplitudes also give good results for the known anisotropic $\alpha-$particle emission of the favored decays of odd nuclei in the same mass region. PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures uuencoded gz-compressed .tar file To appear in Physical Review Letter

Bacterial adherence to mucosal epithelium in the upper airways has less significance than believed

BACKGROUND: Bacterial adherence to the upper airway epithelium is considered to be an important phenomenon in the pathogenesis of infections. However, the evidence for the hypothesis that bacterial adherence to mucosal epithelial cells has significance for pathogenesis of mucosal infections is based on studies using indirect techniques. We could find no biopsy studies with direct ocular observations of significant numbers of bacteria adhering to upper airway mucosal epithelial cells either in health or during disease. RESULTS: We studied specimens from healthy and infected tonsillar epithelium and specimens from the soft palate epithelium obtained by surgery. The specimens were examined by TEM. In the vast majority of specimens, we found no bacteria adhering to the epithelial cells in the mucosal line regardless of whether the patient was infected or not. Bacteria adhering to shed epithelial cells were seen in higher numbers. Furthermore, as bacteria are small compared to epithelial cells, we calculated the risk of overlooking every adhered bacteria in a section if bacterial adherence was such a significant phenomenon as earlier suggested. We found this risk to be very small. CONCLUSION: We conclude that bacterial adherence to mucosal surface epithelial cells is not a significant phenomenon, either in healthy mucosa in the upper airways or during infection. This is also in line with our earlier results, where we have shown that the site for the infectious process in pharyngotonsillitis is in the secretion on the tonsillar mucosal surface

Site-specific Protein Photochemical Covalent Attachment to Carbon Nanotube Side Walls and its Electronic Impact on Single Molecule Function

This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordFunctional integration of proteins with carbon-based nanomaterials such as nanotubes holds great promise in emerging electronic and optoelectronic applications. Control over protein attachment poses a major challenge for consistent and useful device fabrication, especially when utilizing single/few molecule properties. Here, we exploit genetically encoded phenyl azide photochemistry to define the direct covalent attachment of four different proteins, including the fluorescent protein GFP and a -lactamase binding protein (BBP), to carbon nanotube side walls. AFM showed that on attachment BBP could still recognize and bind additional protein components. Single molecule fluorescence revealed that on attachment to SWCNTs function was retained and there was feedback to GFP in terms of fluorescence intensity and improved resistance to photobleaching; GFP is fluorescent for much longer on attachment. The site of attachment proved important in terms of electronic impact on GFP function, with the attachment site furthest from the chromophore having the larger effect on fluorescence. Our approach provides a versatile and general method for generating intimate protein-CNT hybrid bioconjugates. It can be potentially applied easily to any protein of choice; attachment position and thus interface characteristics with the CNT can easily be changed by simply placing the phenyl azide chemistry at different residues by gene mutagenesis. Thus, our approach will allow consistent construction and modulate functional coupling through changing the protein attachment position.Biotechnology and Biological Sciences Research Council (BBSRC)Engineering and Physical Sciences Research Council (EPSRC)Cardiff Synthetic Biology InitiativeSynbiCITEWellcome Trus

The deuteron: structure and form factors

A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

Site-specific protein photochemical covalent attachment to carbon nanotube side walls and its electronic impact on single molecule function

Functional integration of proteins with carbon-based nanomaterials such as nanotubes holds great promise in emerging electronic and optoelectronic applications. Control over protein attachment poses a major challenge for consistent and useful device fabrication, especially when utilizing single/few molecule properties. Here, we exploit genetically encoded phenyl azide photochemistry to define the direct covalent attachment of four different proteins, including the fluorescent protein GFP and a β-lactamase binding protein (BBP), to carbon nanotube side walls. AFM showed that on attachment BBP could still recognize and bind additional protein components. Single molecule fluorescence revealed that on attachment to SWCNTs function was retained and there was feedback to GFP in terms of fluorescence intensity and improved resistance to photobleaching; GFP is fluorescent for much longer on attachment. The site of attachment proved important in terms of electronic impact on GFP function, with the attachment site furthest from the chromophore having the larger effect on fluorescence. Our approach provides a versatile and general method for generating intimate protein–CNT hybrid bioconjugates. It can be potentially applied to any protein of choice; the attachment position and thus interface characteristics with the CNT can easily be changed by simply placing the phenyl azide chemistry at different residues by gene mutagenesis. Thus, our approach will allow consistent construction and modulate functional coupling through changing the protein attachment position

Do Biofilm Formation and Interactions with Human Cells Explain the Clinical Success of Acinetobacter baumannii?

BACKGROUND: The dramatic increase in antibiotic resistance and the recent manifestation in war trauma patients underscore the threat of Acinetobacter baumannii as a nosocomial pathogen. Despite numerous reports documenting its epidemicity, little is known about the pathogenicity of A. baumannii. The aim of this study was to obtain insight into the factors that might explain the clinical success of A. baumannii. METHODOLOGY/PRINCIPAL FINDINGS: We compared biofilm formation, adherence to and inflammatory cytokine induction by human cells for a large panel of well-described strains of A. baumannii and compared these features to that of other, clinically less relevant Acinetobacter species. Results revealed that biofilm formation and adherence to airway epithelial cells varied widely within the various species, but did not differ among the species. However, airway epithelial cells and cultured human macrophages produced significantly less inflammatory cytokines upon exposure to A. baumannii strains than to strains of A. junii, a species infrequently causing infection. CONCLUSION/SIGNIFICANCE: The induction of a weak inflammatory response may provide a clue to the persistence of A. baumannii in patients

Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study

International audienc

Maroon Archaeology Beyond the Americas: A View From Kenya

Archaeological research on Maroons—that is, runaway slaves—has been largely confined to the Americas. This essay advocates a more global approach. It specifically uses two runaway slave communities in 19th-century coastal Kenya to rethink prominent interpretive themes in the field, including “Africanisms,” Maroons’ connections to indigenous groups, and Maroon group cohesion and identity. This article’s analysis demonstrates that the comparisons enabled by a more globalized perspective benefit the field. Instead of eliding historical and cultural context, these comparisons support the development of more localized and historically specific understandings of individual runaway slave communities both in Kenya and throughout the New World