1,648 research outputs found

    Handling Confidential Data on the Untrusted Cloud: An Agent-based Approach

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    Cloud computing allows shared computer and storage facilities to be used by a multitude of clients. While cloud management is centralized, the information resides in the cloud and information sharing can be implemented via off-the-shelf techniques for multiuser databases. Users, however, are very diffident for not having full control over their sensitive data. Untrusted database-as-a-server techniques are neither readily extendable to the cloud environment nor easily understandable by non-technical users. To solve this problem, we present an approach where agents share reserved data in a secure manner by the use of simple grant-and-revoke permissions on shared data.Comment: 7 pages, 9 figures, Cloud Computing 201

    On political parties in contemporary democracies. From the classic perspective to the current debate.

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    The crisis of political parties in contemporary societies and democracies is composed of different points of views, that require a joint effort for social and political science to try to understand the changing relation-ship between citizens and parties. Compared to the political mass models, which are typical of the second half of the twentieth century, parties undergo deep processes of transformation. The beginning of a critical season for the traditional forms of political organization goes back to those years; and this critical season can be configured as ideological, organizational and institutional. Between the twentieth and twenty-first century, the political parties has strengthened the structure of their political organization and the weight of their parliamentary activities within the institutions, becoming more and more «state-centered parties», characterized by the progressive reduction of the forms of territorial settlement and the growth of the im-portance of central organisms and the representatives of the assemblies, especially those elected in na-tional parliaments. This results in significant changes of the organizational model and their political func-tions. In the face of these changes, will the parties still remain a key player for the functioning of contem-porary democracy? We will focus on three fundamental steps: the analysis of the creation process of par-ties and of their function; the description of the most recent perspectives in political parties; the analysis of the relationship between the personalisation of politics and the passage to leader democracy

    iPrivacy: a Distributed Approach to Privacy on the Cloud

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    The increasing adoption of Cloud storage poses a number of privacy issues. Users wish to preserve full control over their sensitive data and cannot accept that it to be accessible by the remote storage provider. Previous research was made on techniques to protect data stored on untrusted servers; however we argue that the cloud architecture presents a number of open issues. To handle them, we present an approach where confidential data is stored in a highly distributed database, partly located on the cloud and partly on the clients. Data is shared in a secure manner using a simple grant-and-revoke permission of shared data and we have developed a system test implementation, using an in-memory RDBMS with row-level data encryption for fine-grained data access controlComment: 13 pages, International Journal on Advances in Security 2011 vol.4 no 3 & 4. arXiv admin note: substantial text overlap with arXiv:1012.0759, arXiv:1109.355

    On Political Parties in Contemporary Democracies: From the classic perspective to the current debate

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    The crisis of political parties in contemporary societies and democracies is composed of differ-ent points of views, that require a joint effort for social and political science to try to understand the changing relationship between citizens and parties. Compared to the political mass models, which are typ-ical of the second half of the twentieth century, parties undergo deep processes of transformation. The beginning of a critical season for the traditional forms of political organization goes back to those years; and this critical season can be configured as ideological, organizational and institutional. Between the twentieth and twenty-first century, the political parties has strengthened the structure of their political organization and the weight of their parliamentary activities within the institutions, becoming more and more «state-centered parties», characterized by the progressive reduction of the forms of territorial set-tlement and the growth of the importance of central organisms and the representatives of the assemblies, especially those elected in national parliaments. This results in significant changes of the organizational model and their political functions. In the face of these changes, will the parties still remain a key player for the functioning of contemporary democracy? We will focus on three fundamental steps: the analysis of the creation process of parties and of their function; the description of the most recent perspectives in political parties; the analysis of the relationship between the personalisation of politics and the passage to leader democracy

    Lotus tenuis x L. corniculatus interspecific hybridization as a means to breed bloat-safe pastures and gain insight into the genetic control of proanthocyanidin biosynthesis in legumes

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    Background: Proanthocyanidins (PAs) are secondary metabolites that strongly affect plant quality traits. The concentration and the structure of these metabolites influence the palatability and nutritional value of forage legumes. Hence, modulating PAs in the leaves of forage legumes is of paramount relevance for forage breeders worldwide. The lack of genetic variation in the leaf PA trait within the most important forage species and the difficulties in engineering this pathway via the ectopic expression of regulatory genes, prompted us to pursue alternative strategies to enhance this trait in forage legumes of agronomic interest. The Lotus genus includes forage species which accumulate PAs in edible organs and can thus be used as potential donor parents in breeding programs. Results: We recovered a wild, diploid and PA-rich population of L. corniculatus and crossed with L. tenuis. The former grows in an alkaline-salty area in Spain while the latter is a diploid species, grown extensively in South American pastures, which does not accumulate PAs in the herbage. The resulting interspecific hybrids displayed several traits of outstanding agronomic relevance such as rhizome production, PA levels in edible tissues sufficient to prevent ruminal bloating (around 5 mg of PAs/g DW), biomass production similar to the cultivated parent and potential for adaptability to marginal lands. We show that PA levels correlate with expression levels of the R2R3MYB transcription factor TT2 and, in turn, with those of the key structural genes of the epicatechin and catechin biosynthetic pathways leading to PA biosynthesis. Conclusions: The L. tenuis x L. corniculatus hybrids, reported herein, represent the first example of the introgression of the PA trait in forage legumes to levels known to provide nutritional and health benefits to ruminants. Apart from PAs, the hybrids have additional traits which may prove useful to breed forage legumes with increased persistence and adaptability to marginal conditions. Finally, our study suggests the hybrids and their progeny are an invaluable tool to gain a leap forward in our understanding of the genetic control of PA biosynthesis and tolerance to stresses in legumes.Fil: Escaray, Francisco José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Passeri, Valentina. Institute of Biosciences and BioResources; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Babuin, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Marco, Francisco. Universidad de Valencia; EspañaFil: Carrasco, Pedro. Universidad de Valencia; EspañaFil: Damiani, Francesco. Consiglio Nazionale delle Ricerche; Italia. Institute of Biosciences and BioResources; ItaliaFil: Pieckenstain, Fernando Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Paolocci, Francesco. Consiglio Nazionale delle Ricerche; Italia. Institute of Biosciences and BioResources; ItaliaFil: Ruiz, Oscar Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

    Simple and fast orotracheal intubation procedure in rat

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    Introduction: Endotracheal intubation in the rat is difficult because of extremely small size of anatomical structures (oral cavity, epiglottis and vocal cords), small inlet for an endotracheal tube and the lack of proper techniacal instruments. Matherial and Methods: In this study we used seventy rats weighthing 400-500 g. The equipment needed for intubation was an operating table, a longish of cotton, a cotton tip, orotracheal tube, neonatal laryngoscope KTR4, small animal ventilator, and isoflurane for inhalation anaesthesia. Premedication was carried out by medetomidine hydrochloride 1 mg/mL; then, thanks to a closed glass chamber, a mixture of oxygen and isoflurane was administered. By means of neonatal laryngoscope the orotracheal tube was advanced into the oral cavity untile the wire guide was visualized trough the vocal cords; then it was passed through them. The tube was introduced directly into into the larynx over the wire guide; successively, the guide was removed and the tube placed into the trachea. Breathing was confirmed using a glove, cut at the end of a finger, simulating a small ballon. Conclusions: We believe that our procedure is easier and faster than those previously reported in scientific literature. (www.actabiomedica.it

    No surviving companion in Kepler's supernova

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    We have surveyed Kepler's supernova remnant in search of the companion star of the explosion. We have gone as deep as 2.6 solar luminosities in the stars within 20% of the radius of the remnant. We use FLAMES at the VLT-UT2 telescope to obtain high resolution spectra of the stellar candidates selected from HST images. The resulting set of stellar parameters suggests that these stars come from a rather ordinary mixture of field stars (mostly giants). A few of the stars seem to have low [Fe/H] (< -1) and they are consistent with being metal-poor giants. The radial velocities and rotational velocities vrot sin i are very well determined. There are no fast rotating stars as vrot sin i < 20 km/s. The radial velocities from the spectra and the proper motions determined from HST images are compatible with those expected from the Besan\c{c}on model of the Galaxy. The strong limits placed on luminosity suggest that this supernova could have arisen either from the core-degenerate scenario or from the double-degenerate scenario.Comment: ApJ accepted, 7 figures and 7 table

    Laparoscopic Myomectomy for Very Large Myomas Using an Isobaric (Gasless) Technique

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    Laparoscopic myomectomy using pneumoperitoneum for large myomas (> or = 8 cm) is hindered by several factors, such as the increased operative time, the risk of perioperative bleeding, and the risk of conversion to laparotomy. With the introduction of isobaric laparoscopy using abdominal wall lifting, this procedure can be performed using conventional surgical instruments introduced through small abdominal incisions. The aim of this study was to evaluate the feasibility, reproducibility, and safety of isobaric laparoscopic myomectomy for very large myomas > or = 10 cm using a subcutaneous abdominal wall-lifting device
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