Effect of the inelastic dynamic soil-structure interaction on the seismic vulnerability assessment

This paper presents a study of the influence of inelastic dynamic soil-structure interaction (DSSI) on the seismic vulnerability assessment of buildings. The seismic vulnerability is evaluated in terms of analytical fragility curves constructed on the basis of non-linear dynamic finite elements (FE) analysis. An analytical sensibility strategy is introduced in order to define a suitable size of the motion database to be used for computing fragility curves. The fragility curves developed in this study are compared with reference curves. Concerning the effect of the inelastic DSSI, a general reduction of seismic demand when DSSI phenomena are included is found. Derived fragility curve reflects this seismic demand reduction. The importance of the ground motion database is highlighted in terms of the variability of parameters describing derived fragility curves. Comparison with reference curves are satisfactory. Findings illustrate clearly the importance and the advantages of an adequate DSSI effects evaluation.     

Miracidial infectivity of Hypoderaeum conoideum (Trematoda: Echinostomatidae): differential susceptibility of two lymnaeid species

A study was made of the infectivity of Hypoderaeum conoideum miracidia to a range of laboratory-reared specimens of freshwater snail species (Lymnaea peregra, L. corvus, Physella acuta, and Gyraulus chinensis) that coexist with the parasite in the same natural habitat. L. peregra and L. corvus were found to be equally susceptible to the parasite when specimens of each snail species were singly exposed to miracidia. However, when miracidia could choose either lymnaeid species, they showed a high degree of specificity toward L. peregra. The results obtained suggest that H. conoideum miracidia are capable of distinguishing among these lymnaeids in their orientation to the host. This indicates that miracidia might achieve specificity before actually contacting the snail host and suggests that during the host-snail orientation process they respond to signals different from those generated upon snail contact and invasion. The specificity toward L. peregra observed in H. conoideum miracidia seems to indicate adaptation to the snail community in their natural habitat, resulting in enhancement of their transmission.     

The vaccinia virus 14-kilodalton (A27L) fusion protein forms a triple coiled-coil structure and interacts with the 21-kilodalton (A17L) virus membrane protein through a C-terminal alpha-helix

The vaccinia virus 14-kDa protein (encoded by the A27L gene) plays an important role in the biology of the virus, acting in virus-to-cell and cell-to-cell fusions. The protein is located on the surface of the intracellular mature virus form and is essential for both the release of extracellular enveloped virus from the cells and virus spread. Sequence analysis predicts the existence of four regions in this protein: a structureless region from amino acids 1 to 28, a helical region from residues 29 to 37, a triple coiled-coil helical region from residues 44 to 72, and a Leu zipper motif at the C terminus. Circular dichroism spectroscopy, analytical ultracentrifugation, and chemical cross-linking studies of the purified wild-type protein and several mutant forms, lacking one or more of the above regions or with point mutations, support the above-described structural division of the 14-kDa protein. The two contiguous cysteine residues at positions 71 and 72 are not responsible for the formation of 14-kDa protein trimers. The location of hydrophobic residues at the a and d positions on a helical wheel and of charged amino acids in adjacent positions, e and g, suggests that the hydrophobic and ionic interactions in the triple coiled-coil helical region are involved in oligomer formation. This conjecture was supported by the construction of a three-helix bundle model and molecular dynamics. Binding assays with purified proteins expressed in Escherichia coli and cytoplasmic extracts from cells infected with a virus that does not produce the 14-kDa protein during infection (VVindA27L) show that the 21-kDa protein (encoded by the A17L gene) is the specific viral binding partner and identify the putative Leu zipper, the predicted third alpha-helix on the C terminus of the 14-kDa protein, as the region involved in protein binding. These findings were confirmed in vivo, following transfection of animal cells with plasmid vectors expressing mutant forms of the 14-kDa protein and infected with VVindA27L. We find the structural organization of 14kDa to be similar to that of other fusion proteins, such as hemagglutinin of influenza virus and gp41 of human immunodeficiency virus, except for the presence of a protein-anchoring domain instead of a transmembrane domain. Based on our observations, we have established a structural model of the 14-kDa protein.     

Bacterial adherence on UHMWPE with vitamin E: an in vitro study

Orthopaedic materials may improve its capacity to resist bacterial adherence, and subsequent infection. Our aim was to test the bacterial adherence to alpha-tocopherol (frequently named vitamin E, VE) doped or blended UHMWPE with S. aureus and S. epidermidis, compared to virgin material. Collection strains and clinical strains isolated from patients with orthopaedic infections were used, with the biofilm-developing ability as a covariable. While collection strains showed significantly less adherence to VE-UHMWPE, some clinical strains failed to confirm this effect, leading to the conclusion that VE doped or blended UHMWPE affects the adherence of some S. epidermidis and S. aureus strains, independently of the concentration in use, but the results showed important intraspecies differences and cannot be generalized.     

Association between LAG3/CD4 Genes Variants and Risk for Multiple Sclerosis

Several recent works have raised the possibility of the contribution of the lymphocyte activation gene 3 (LAG3) protein in the inflammatory processes of multiple sclerosis (MS). Results of studies on the possible association between LAG3 gene variants and the risk of MS have been inconclusive. In this study, we tried to show the possible association between the most common single nucleotide variants (SNVs) in the CD4 and LAG3 genes (these two genes are closely related) and the risk of MS in the Caucasian Spanish population. We studied the genotypes and allelic variants CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 in 300 patients diagnosed with MS and 400 healthy patients using specific TaqMan-based qPCR assays. We analyzed the possible influence of the genotype frequency on age at the onset of MS, the severity of MS, clinical evolutive subtypes of MS, and the HLADRB1*1501 genotype. The frequencies of the CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 genotypes and allelic variants were not associated with the risk of MS and were unrelated to gender, age at onset and severity of MS, the clinical subtype of MS, and HLADRB1*1501 genotype. The results of the current study showed a lack of association between the CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 SNVs and the risk of developing MS in the Caucasian Spanish population.     

Coherent interaction of atoms with a beam of light confined in a light cage

Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms is essential for quantum technologies. Miniaturise...     

Vaccinia virus 15-kilodalton (A14L) protein is essential for assembly and attachment of viral crescents to virosomes

Early stages in vaccinia virus (VV) assembly involve the recruitment of cellular membranes from the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) to virus factories (or virosomes). The key viral factors involved in this process are not yet known. We have previously identified and characterized two viral proteins, of 21 kDa (A17L gene) and 15 kDa (A14L gene), that associate with tubulovesicular elements related to the ERGIC and are localized in viral membranes at all stages of virion assembly. We showed that the 21-kDa protein is not responsible for the recruitment of membranes from the ERGIC to viral factories. However, it appears to be essential for the organization of viral membranes. In this investigation we have generated a VV recombinant, VVindA14L, in which the expression of the A14L gene is inducibly regulated by the Escherichia coli lacI operator-repressor system. Repression of 15-kDa protein synthesis has a dramatic effect on virus yields and severely impairs plaque formation. Compared to wild-type VV, reduced amounts of 15-kDa protein are produced in VVindA14L-infected cells in the presence of IPTG (isopropyl-beta-D-thiogalactoside), and this correlates with a small-plaque phenotype and reduced VVindA14L yields under these conditions. In the absence of the 15-kDa protein, early and late viral protein syntheses proceed normally; however, proteolytic cleavage of the major core precursors is inhibited. Electron microscopic examination of cells infected with VVindA14L under nonpermissive conditions reveals the presence of numerous membranous elements that look like unfinished or disassembled crescents interspersed between electron-dense masses. These abnormal membrane elements are usually well separated from the surfaces of the dense structures. These findings show that the 15-kDa protein is essential for VV morphogenesis and indicate that this polypeptide is necessary both for the correct assembly of viral crescents and for their stable attachment to the surfaces of viral factories.     

Surface plasmon excitation in fiber-optics sensors: a noveltheoretical approach

A theoretical method for the study of surface plasmon excitation in metallic layers, as used in fiber-optics sensors, is presented. It is based in the calculation of the propagated fields in the waveguide structure and allows us to compute the loss of optical power in the fiber (which is the measured parameter) from energy conservation considerations. The agreement with experimental data obtained with real sensors is good. The method is conceptually simple and can be adapted to different configurations of the sensors     

XI. Yeast sequencing reports. The complete sequence of an 18,002 bp segment of Saccharomyces cerevisiae chromosome XI contains the HBS1, MRP-L20 and PRP16 genes,and six new open reading frames

We report the sequence of an 18,002 bp DNA fragment from the right arm of Saccharomyces cerevisiae chromosome XI. This segment contains nine complete open reading frames (ORFs), YKR401 to YKR409, and part of another ORF, YKR400, covering altogether 87·2% of the entire sequence. One of them, YKR400, encodes an NAD-dependent 5,10-methylene-tetrahydrofolate dehydrogenase. YKR404, YKR405 and YKR406 correspond to the previously characterized HBS1, MRP-L20 and PRP16 genes, coding for a translation elongation factor, a mitochondrial ribosomal protein and an ATP-binding protein, respectively. The putative product of YKR407 contains the zinc-binding region signature of neutral zinc metallopeptidases. The five other ORFs do not show significant homology to any known protein. The sequence data reported here have been assigned EMBL accession number Z27116.