6,411 research outputs found

    Dual-use Molecules from Yeast

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    This year the OPCW, the implementing body for the Chemical Weapons Convention, celebrates the 20th anniversary of entry into forces. In 2014, this organization examined the impact of new technologies in the field of chemical and biological weapons, in particular the “Convergence” of Chemistry and Biology. An OPCW report of the Scientific Advisory Group highlighted the importance of monitoring developments in science and technology: “New production processes, combined with developments in drug discovery and delivery, could be exploited in the development of new toxic chemicals that could be used as weapons.” 1 Indeed, since 2008, Synthetic Biology is monitored also by other international organizations, such as the Nonproliferation Export Control Regimes Australia Group

    Common currency, common identity? The impact of the Euro introduction on European identity

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    Does European state building go hand in hand with European nation building? This article engages with the scholarly debate on the dynamic relationship between the construction of supranational political institutions that exert key functions of sovereignty and collective identities by investigating the extent to which the adoption of the Euro as a currency is associated with a decrease in the share of Europeans who identify exclusively with their nation and not with the European Union. In detail, by using a dynamic panel-data model on 26 European Union countries in the post-Maastricht period (1996–2017), our results show that the Euro has fostered European identity, leading to a small but significant decrease (-3%) in the share of Europeans with exclusive national identity

    The Potential Role of Exercise Training and Mechanical Loading on Bone-Associated Skeletal Nerves

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    : The spatial distribution, innervation, and functional role of the bone-associated skeletal nerves have been previously reported in detail. However, studies examining exercise-induced associations between skeletal nerves and bone metabolism are limited. This review introduces a potential relationship between exercise and the skeletal nerves and discusses how it can contribute to exercise-induced bone anabolism. First, the background and current understanding of nerve fiber types and their functions in the skeleton are provided. Next, the influence of exercise and mechanical loading on the skeletal nervous system is elaborated. Effective synthesis of recent studies could serve as an established baseline for the novel discovery of the effects of exercise on skeletal nerve density and bone anabolic activity in the future. Therefore, this review overviews the existing evidence for the neural control of bone metabolism and the potential positive effects of exercise on the peripheral skeletal nervous system. The influence of exercise training models on the relationships of sensory nerve signals with osteoblast-mediated bone formation and the increased bone volume provides the first insight on the potential importance of exercise training in stimulating positive adaptations in the skeletal nerve-bone interaction and its downstream effect on bone metabolism, thereby highlighting its therapeutic potential in a variety of clinical populations

    Ground Penetrating Radar (GPR): an application for evaluating the state of maintenance of the building coating

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    Ground Penetrating Radar (GPR) is a non-destructive methodology. For the localisation of buried structures, it uses short time duration electromagnetic (EM) pulses lasting from about 1 ns to about 30 ns. Therefore, GPR is characterised by a wide frequency band ranging from 10 MHz to some GHz, and is useful in the localisation of EM discontinuities in the subsurface with high resolution. This paper describes an application of GPR to evaluate the state of maintenance of some travertine panels attached to the inside walls of a building housing the Bank of Naples in Campobasso and in danger of falling because of the numerous voids present between the wall and the panels. The aim of the survey was to assess whether the GPR technique could be used to detect the voids behind the travertine panels. The study was made to assist the design of the restoration works of the travertine covering. Because of the very narrow thickness of both the travertine plates and the voids, special care was needed in the acquisition and processing steps. The measurements were performed on two panels: one purposely put on to the laboratory wall with a known position of the voids; the other one selected from among the panels to be restored. Although pushed to the limit of the resolution achievable by the available antenna, the study has given quite good results

    Characterization of a fully active N-terminal 37-kDa polypeptide obtained by limited tryptic cleavage of pig kidney D-amino acid oxidase.

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    In order to obtain further information on the structure of D-amino acid oxidase (EC 1.4.3.3), limited proteolysis experiments have been carried out on its apo-, holo-, and holoenzyme-benzoate forms. The enzyme is unsensitive to 10% (w/w) chymotrypsin, while incubation with 10% (w/w) trypsin, under nondenaturating conditions, produces inactivation and proteolysis patterns which are different for the three forms of enzyme analyzed. These results confirm the previously reported conformational changes which occur upon binding of coenzyme to the apoprotein, and of benzoate to holoenzyme. The stable 37.0-kDa polypeptide, obtained from the apo- and holoenzyme-benzoate complex upon cleavage of a C-terminal 2.0-kDa fragment, retains full catalytic activity with unaltered kinetic parameters, and the coenzyme binding properties of the native enzyme. These results are in agreement with the tentative localization of the FAD-binding domain in the N-terminal region of the enzyme, and with the hypothesis that the function of the C-terminal region of D-amino acid oxidase could be related to the import of the enzyme into the peroxisomes, as suggested by Gould et al. (Gould, S. J., Keller, G. A., and Subramani, S. (1988) J. Cell. Biol. 107, 897-905)

    Virulence factor of Candida tropicalis isolated from hospitalized patients

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    Candida tropicalis has been reported to be one of the Candida species which is most likely to cause bloodstream and urinary tract infections in hospitals. Several virulence factors seem to be responsible for C. tropicalis infections, which present high potential for dissemination and mortality. The aim of this study was to investigate the correlation between different virulence factors (enzymes secretion, adhesion and biofilm formation) and antifungal susceptibility of several C. tropicalis clinical isolates. This study was conducted with 8 isolates of C. tropicalis obtained from urine cultures (4), from blood culture (1) and from central venous catheter (1), from patients admitted to intensive care units at the University Hospital in Maringá, Paraná, Brazil. C. tropicalis ATCC 750 was also used, as a control. Virulence factors evaluated included: adhesion to epithelial cells and silicone, biofilm formation and enzyme production (hemolysins, proteinases, and phospholipases). Susceptibility to fluconazole, itraconazole, voriconazole, and amphotericin B was also determined, by E-test. Regarding adhesion, it can be highlighted that C. tropicalis adhered significantly more (p<0.05) to epithelial cells than to silicone. Morevoer, it was verified that all C. tropicalis were prone to form biofilms on silicone. Regarding C. tropicalis enzymatic activity, it was possible to verify that all isolates were able to express total hemolytic activity on sheep-blood agar medium supplemented with glucose. However, proteinase was only produced by two urine isolates and by the isolates from catheter and blood and only one C. tropicalis (from catheter) was phospholipase positive. All isolates were susceptible to voriconazole, fluconazole and amphotericin B. The largest percentage of susceptibility-dose dependence was observed for itraconazole in 4 strains (57.1%). Furthermore one clinical isolate (14.3%) from urine was found to be resistant to the same compound (MIC = 1 µg/ml). Thus, it is possible to conclude that there was no direct correlation between the virulence factors assayed (secretion of enzymes, adhesion to epithelial cells and silicone and biofilm formation). Concerning C. tropicalis susceptibility, it was not possible to establish any relation with Candida virulence factors as well. However, it is important to highlight that all isolates presented one or more virulence factors

    Differential Functional Constraints Cause Strain-Level Endemism in Polynucleobacter Populations.

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    The adaptation of bacterial lineages to local environmental conditions creates the potential for broader genotypic diversity within a species, which can enable a species to dominate across ecological gradients because of niche flexibility. The genus Polynucleobacter maintains both free-living and symbiotic ecotypes and maintains an apparently ubiquitous distribution in freshwater ecosystems. Subspecies-level resolution supplemented with metagenome-derived genotype analysis revealed that differential functional constraints, not geographic distance, produce and maintain strain-level genetic conservation in Polynucleobacter populations across three geographically proximal riverine environments. Genes associated with cofactor biosynthesis and one-carbon metabolism showed habitat specificity, and protein-coding genes of unknown function and membrane transport proteins were under positive selection across each habitat. Characterized by different median ratios of nonsynonymous to synonymous evolutionary changes (dN/dS ratios) and a limited but statistically significant negative correlation between the dN/dS ratio and codon usage bias between habitats, the free-living and core genotypes were observed to be evolving under strong purifying selection pressure. Highlighting the potential role of genetic adaptation to the local environment, the two-component system protein-coding genes were highly stable (dN/dS ratio, &lt; 0.03). These results suggest that despite the impact of the habitat on genetic diversity, and hence niche partition, strong environmental selection pressure maintains a conserved core genome for Polynucleobacter populations. IMPORTANCE Understanding the biological factors influencing habitat-wide genetic endemism is important for explaining observed biogeographic patterns. Polynucleobacter is a genus of bacteria that seems to have found a way to colonize myriad freshwater ecosystems and by doing so has become one of the most abundant bacteria in these environments. We sequenced metagenomes from locations across the Chicago River system and assembled Polynucleobacter genomes from different sites and compared how the nucleotide composition, gene codon usage, and the ratio of synonymous (codes for the same amino acid) to nonsynonymous (codes for a different amino acid) mutations varied across these population genomes at each site. The environmental pressures at each site drove purifying selection for functional traits that maintained a streamlined core genome across the Chicago River Polynucleobacter population while allowing for site-specific genomic adaptation. These adaptations enable Polynucleobacter to become dominant across different riverine environmental gradients

    Application of 3D visualization techniques in the analysis of GPR data for archaeology

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    In this work, some results of a GPR survey carried out in a 10000 m2 large archaeological site, located in Lecce (Italy) near to a necropolis dating from the Messapian to the Roman imperial age, are reported. After a preliminary survey, performed on the entire area along parallel 1 m spaced profiles using a 200 MHz and a 500 MHz antenna in single-fold continuous mode, some smaller areas were selected, where the survey was repeated decreasing the profile spacing down to 0.50 m for the lower frequency antenna and to 0.25 m for the higher one. For two selected zones (D and B) the processed data were visualized in 3D space not only by the standard time slice technique, but also by two recently proposed approaches, namely by iso-amplitude surfaces of the complex trace amplitude and by 3D projection of energy and envelope stacks. The immediacy in revealing the spatial positioning of highly reflecting bodies, such as the anomaly interpreted as an old refilled cistern in zone D, makes 3D visualization techniques very attractive in archaeological applications of GPR. Their sensitivity to the signal/noise ratio is, on the other hand, highlighted by the quite poor performance in zone B, where the only reliable result provided by all the techniques was the soil/bedrock reflection, whereas none of them could effectively enhance the visibility of weak dipping reflections noted on 2D sections and probably related to fractures or bedding planes in the calcarenitic basement. The performance of the various techniques in these two different situations allowed insights into their main advantages and drawbacks to be gained
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