1,113 research outputs found

    University Students' Democratic Values and Attitudes toward Democracy in Hungary

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    In December 2012 Hungarian students rallied to protest against cutbacks in scholarships and to the introduction of tuition fees. Two years later, in October 2014, thousands of (mostly young) people gathered at anti-government demonstrations against a proposal to include the taxation of Internet usage in the Taxation Law. The article brings results on changes in patterns of democratic citizenship among Hungarian students and demonstrates that despite their issue related ‘rational rebellion’ democratic transition resulted in a low-level of political participation and commitment to democratic values among them. We describe democratic attitudes of Hungarian college and university students by using both qualitative and quantitative data asking if they have developed a commitment to democracy as a system of rule

    Conformation and concerted dynamics of the integrin-binding site and the C-terminal region of echistatin revealed by homonuclear NMR

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    Echistatin is a potent antagonist of the integrins αvβ3, α5β1 and αIIbβ3. Its full inhibitory activity depends on an RGD (Arg-Gly- Asp) motif expressed at the tip of the integrin-binding loop and on its C-terminal tail. Previous NMR structures of echistatin showed a poorly defined integrin-recognition sequence and an incomplete C-terminal tail, which left the molecular basis of the functional synergy between the RGD loop and the C-terminal region unresolved. We report a high-resolution structure of echistatin and an analysis of its internal motions by off-resonance ROESY (rotating-frame Overhauser enhancement spectroscopy). The fulllength C-terminal polypeptide is visible as a β-hairpin running parallel to the RGD loop and exposing at the tip residues Pro43, His44 and Lys45. The side chains of the amino acids of the RGD motif have well-defined conformations. The integrin-binding loop displays an overall movement with maximal amplitude of 30◦. Internal angular motions in the 100–300 ps timescale indicate increased flexibility for the backbone atoms at the base of the integrin- recognition loop. In addition, backbone atoms of the amino acids Ala23 (flanking the R24GD26 tripeptide) and Asp26 of the integrin-binding motif showed increased angular mobility, suggesting the existence of major and minor hinge effects at the base and the tip, respectively, of the RGD loop. A strong network of NOEs (nuclear Overhauser effects) between residues of the RGD loop and the C-terminal tail indicate concerted motions between these two functional regions. A full-length echistatin– αvβ3 docking model suggests that echistatin’s C-terminal amino acids may contact αv-subunit residues and provides new insights to delineate structure–function [email protected]; [email protected]; [email protected]; [email protected]

    Group authorship, an excellent opportunity laced with ethical, legal and technical challenges

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    Group authorship (also known as corporate authorship, team authorship, consortium authorship) refers to attribution practices that use the name of a collective (be it team, group, project, corporation, or consortium) in the authorship byline. Data shows that group authorships are on the rise but thus far, in scholarly discussions about authorship, they have not gained much specific attention. Group authorship can minimize tensions within the group about authorship order and the criteria used for inclusion/exclusion of individual authors. However, current use of group authorships has drawbacks, such as ethical challenges associated with the attribution of credit and responsibilities, legal challenges regarding how copyrights are handled, and technical challenges related to the lack of persistent identifiers (PIDs), such as ORCID, for groups. We offer two recommendations: 1) Journals should develop and share context-specific and unambiguous guidelines for group authorship, for which they can use the four baseline requirements offered in this paper; 2) Using persistent identifiers for groups and consistent reporting of members’ contributions should be facilitated through devising PIDs for groups and linking these to the ORCIDs of their individual contributors and the Digital Object Identifier (DOI) of the published item.</p

    Additive Manufacturing of 17-4PH Alloy: Tailoring the Printing Orientation for Enhanced Aerospace Application Performance

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    Additive manufacturing (AM) is one of the fastest-growing markets of our time. During its journey in the past 30 years, its key to success has been that it can easily produce extremely complex shapes and is not limited by tooling problems when a change in geometry is desired. This flexibility leads to possible solutions for creating lightweight structural elements while keeping the mechanical properties at a stable reserve factor value. In the aerospace industry, several kinds of structural elements for fuselage and wing parts are made from different kinds of steel alloys, such as 17-4PH stainless steel, which are usually milled from a block material made using conventional processing (CP) methods. However, these approaches are limited when a relatively small element must withstand greater forces that can occur during flight. AM can bridge this problem with a new perspective, mainly using thin walls and complex shapes while maintaining the ideal sizes. The downside of the elements made using AM is that the quality of the final product is highly dependent on the build/printing orientation, an issue extensively studied and addressed by researchers in the field. During flight, some components may experience forces that predominantly act in a single direction. With this in mind, we created samples with the desired orientation to maximize material properties in a specific direction. The goal of this study was to demonstrate that an additively manufactured part, produced using laser powder bed fusion (LPBF), with a desired build orientation has exceptional properties compared to parts produced via conventional methods. To assess the impact of the build orientation on the LPBF parts’ properties, one-dimensional tensile and dynamic fracture toughness tests were deployed

    Poreklo i genetička struktura nekoliko mađarskih divljih i domestifikovanih populacija potočne pastrmke na osnovu PCR-RFLP i mikrosatelitskih markera

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    U Evropi je, na osnovu studija mitohondrijalne DNK, identifikovano pet evolutivnih linija potočne pastrmke (Salmo trutta m. fario L. 1758): Atlanska, Dunavska, Mediteranska, Jadranska i Mramorna. Mađarske linije bi teorijski trebalo da pripadaju Dunavskoj liniji na osnovu hidrogeografije zemlje, ipak, ovo nije potvrđeno genetičkim studijama. Korišćeni su molekularni markeri da bi se ispitalo genetička pozadina populacije potočne pastrmke u Mađarskoj. Istraživanja su uključila jedini matični nasad potočne pastrmke u Mađarskoj, kao i po jedna populacije u planinskim vencima Bükk, Aggtelek, Börzsöny i Visegrádi, po jedna populacija u svakom. Genetička analiza je do sada sprovedena na 533 individue, isečak peraja je uzorkovan sa svake ribe i PCR-RFLP (kontrolni region mitohondrijalne DNK, laktat dehidrogenaza i somatolaktin geni), kao i analiza mikrosatelitnih markeri (BFRO002, OMM1064, Ssa408uos, SsoSL417, SsoSL438) su bili korišćeni da bi se razlikovale Dunavska i Atlanska linija potočne pastrmke. Na osnovu genetičke analize mitohondrijalne DNK divljih populacija, udeo Dunavskog haplotipa je nizak (< 10 %), sa izuzetkom potoka Apátkúti u planinama Visegrádi, gde je nađena relativno visok udeo Dunavskog haplotipa (34%). 401 analizirani primerak matičnog jata farme je skoro u potpunosti Atlanski haplotip, što ukazuje na efekat osnivača. Iako su kasnije prikupljeni primerci iz obližnjeg potoka i pridodati matičnom jatu, njihov broj je bio ograničen jer su uglavnom svi bili mužjaci. Budući da je jedino matično jato u Mađarskoj, ribe sa ove farme se koriste za poribljavanje od strane ribolovaca, što može dovesti do značajnog uticaja na prirodne populacije. Na osnovu analize nuklearnih markera sve populacije su veoma heterogene. Veliki udeo (60-80%) Atlanskih alela primećen za ove markere na svim lokacijama gde je obavljano uzorkovanje ukazuje na efekat intenzivnog poribljavanja mađarskih salmonidnih regiona. Analize mikrosatelitskih markera su ukazale na visoku heterozigotnost i Hardy-Weinberg-ovu ravnotežu svih populacija

    Debugging of Web Applications with Web-TLR

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    Web-TLR is a Web verification engine that is based on the well-established Rewriting Logic--Maude/LTLR tandem for Web system specification and model-checking. In Web-TLR, Web applications are expressed as rewrite theories that can be formally verified by using the Maude built-in LTLR model-checker. Whenever a property is refuted, a counterexample trace is delivered that reveals an undesired, erroneous navigation sequence. Unfortunately, the analysis (or even the simple inspection) of such counterexamples may be unfeasible because of the size and complexity of the traces under examination. In this paper, we endow Web-TLR with a new Web debugging facility that supports the efficient manipulation of counterexample traces. This facility is based on a backward trace-slicing technique for rewriting logic theories that allows the pieces of information that we are interested to be traced back through inverse rewrite sequences. The slicing process drastically simplifies the computation trace by dropping useless data that do not influence the final result. By using this facility, the Web engineer can focus on the relevant fragments of the failing application, which greatly reduces the manual debugging effort and also decreases the number of iterative verifications.Comment: In Proceedings WWV 2011, arXiv:1108.208

    ADCY5 gene expression in adipose tissue is related to obesity in men and mice

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    Genome wide association studies revealed an association of the single nucleotide polymorphism rs11708067 within the ADCY5 gene—encoding adenylate cyclase 5—with increased type 2 diabetes (T2D) risk and higher fasting glucose. However, it remains unclear whether the association between ADCY5 variants and glycemic traits may involve adipose tissue (AT) related mechanisms. We therefore tested the hypothesis that ADCY5 mRNA expression in human and mouse AT is related to obesity, fat distribution, T2D in humans and high fat diet (HFD) in mice. We measured ADCY5 mRNA expression in paired samples of visceral and subcutaneous adipose tissue from 244 individuals with a wide range of body weight and parameters of hyperglycemia, which have been genotyped for rs11708067. In addition, AT ADCY5 mRNA was assessed in C57BL/6NTac which underwent a 10 weeks standard chow (n = 6) or high fat diet (HFD, n = 6). In humans, visceral ADCY5 expression is significantly higher in obese compared to lean individuals. ADCY5 expression correlates with BMI, body fat mass, circulating leptin, fat distribution, waist and hip circumference, but not with fasting plasma glucose and HbA1c. Adcy5 expression in mouse AT is significantly higher after a HFD compared to chow (p<0.05). Importantly, rs11708067 is not associated with ADCY5 mRNA expression levels in either fat depot in any of the genetic models tested. Our results suggest that changes in AT ADCY5 expression are related to obesity and fat distribution, but not with impaired glucose metabolism and T2D. However, altered ADCY5 expression in AT does not seem to be the mechanism underlying the association between rs11708067 and increased T2D risk

    Regulation of ryanodine receptors by sphingosylphosphorylcholine: Involvement of both calmodulin-dependent and -independent mechanisms

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    Sphingosylphosphorylcholine (SPC), a lipid mediator with putative second messenger functions, has been reported to regulate ryanodine receptors (RyRs), Ca2+ channels of the sarco/endoplasmic reticulum. RyRs are also regulated by the ubiquitous Ca2+ sensor calmodulin (CaM), and we have previously shown that SPC disrupts the complex of CaM and the peptide corresponding to the CaM-binding domain of the skeletal muscle Ca2+ release channel (RyR1). Here we report that SPC also displaces Ca2+-bound CaM from the intact RyR1, which we hypothesized might lead to channel activation by relieving the negative feedback Ca2+CaM exerts on the channel. We could not demonstrate such channel activation as we have found that SPC has a direct, CaM-independent inhibitory effect on channel activity, confirmed by both single channel measurements and [3H]ryanodine binding assays. In the presence of Ca2+CaM, however, the addition of SPC did not reduce [3H]ryanodine binding, which we could explain by assuming that the direct inhibitory action of the sphingolipid was negated by the simultaneous displacement of inhibitory Ca2+CaM. Additional experiments revealed that RyRs are unlikely to be responsible for SPC-elicited Ca2+ release from brain microsomes, and that SPC does not exert detergent-like effects on sarcoplasmic reticulum vesicles. We conclude that regulation of RyRs by SPC involves both CaM-dependent and -independent mechanisms, thus, the sphingolipid might play a pysiological role in RyR regulation, but channel activation previously attributed to SPC is unlikely

    Identification of quantifiable biological parameters for rescue personnel in the context of relational analysis of hazardous environments

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    The previous events in the industry reflect the need to take action to stop or at least slow down the development of damage and to prevent or reduce, as far as possible, their extent. In the case of breakdowns in industrial technological processes, their management requires, in addition to plant maintenance personnel properly trained for such situations, the participation of specialized personnel for interventions in hazardous environments. To form an image, the intervention is described as a set of actions in the facilities of a technological flow in which an event out of technological control was triggered, which aims to stop the negative consequences. The systemic approach of the correlation of hazardous substances in connection with the hazardous environment, of the relationships between the hazardous environment, constructions, technological installations and personnel as well as the identification of the effects of hazardous environments allows the crystallization of a relational analysis of hazardous environments. In this context, rescuers involved in the liquidation of damage must have a high degree of practical and physical training. During the training / interventions, rescuers have the opportunity to constantly monitor their physiological parameters through wearables. This paper aims to identify quantifiable biometric parameters for rescue and rescue personnel in the context of relational analysis of hazardous environments

    Catalog of fundamental mode RR Lyrae stars in the Galactic bulge from the Optical Gravitational Lensing Experiment

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    We present a catalog of 1888 fundamental-mode RR Lyrae stars detected in the Galactic bulge fields of the second phase of the Optical Gravitational Lensing Experiment (OGLE). The catalog includes basic parameters of the light curves, identifications of Blazhko frequencies, V-I colors at minimum light (for most stars), and other information for each star. We detect a high rate of incidence of the Blazhko phenomenon (at least 27.6%), including unprecedentedly many frequency triplets, which we attribute to our sensitive search method. We find that the minimum light V-I color (useful as a reddening indicator) grows slowly redder with increasing period and exhibits a star-to-star scatter of approximately 0.07 mag. We use this color to evaluate the zero-point accuracy of the reddening map of the Galactic bulge derived from OGLE data, and find that in addition to low-level random errors or resolution effects (responsible for much of the scatter), the map may systematically over-represent E(V-I) by approximately 0.05 mag in most fields. We present reasonably robust evidence that the RR Lyrae-to-red clump color separation is larger by 0.05--0.08 mag in the bulge than locally, which argues for caution in the use of these stars for reddening determinations. We consider the RR Lyrae constraint on the Galactocentric distance, but uncertainty about the absolute magnitude calibration leaves significant flexibility in the result. In contrast to previous results, we robustly detect the signature of the Galactic bar in the RR Lyrae population within the inner plus/minus 3 degrees of longitude, and we highlight the apparent differences between the structures traced by the red clump giants and the more metal-poor RR Lyrae stars. (abridged)Comment: Submitted to ApJ, 34 pages aastex including 8 figures, full tables to appear electronically (temporarily available at http://www.astro.princeton.edu/~collinge/RR/
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