TVWS policies to enable efficient spectrum sharing

The transition from analogue to the Digital Terrestrial Television (DTV) in Europe is planned to be completed by the end of the year 2012. The DTV spectrum allocation is such that there are a number of TV channels which cannot be used for additional high power broadcast transmitters due to mutual interference and hence are left unused within a given geographical location, i.e. the TV channels are geographically interleaved. The use of geographically interleaved spectrum provides for the so-called TV white spaces (TVWS) an opportunity for deploying new wireless services. The main objective of this paper is to present the spectrum policies that are suitable for TVWS at European level, identified within the COGEU project. The COGEU project aims the efficient exploitation of the geographical interleaved spectrum (TVWS). COGEU is an ICT collaborative project supported by the European Commission within the 7th Framework Programme. Nine partners from seven EU countries representing academia, research institutes and industry are involved in the project. The COGEU project is a composite of technical, business, and regulatory/policy domains, with the objective of taking advantage of the TV digital switchover by developing cognitive radio systems that leverage the favorable propagation characteristics of the UHF broadcast spectrum through the introduction and promotion of real-time secondary spectrum trading and the creation of new spectrum commons regimes. COGEU will also define new methodologies for compliance testing and certification of TVWS equipment to ensure non-interference coexistence with the DVB-T European standard. The innovation brought by COGEU is the combination of cognitive access to TV white spaces with secondary spectrum trading mechanisms.telecommunications,spectrum management,secondary spectrum market,regulation,TV white spaces,cognitive radio

Do goal orientations really influence performance?

Purpose: The creativity of retail employees seems to be of the utmost importance for ensuring the performance of organizations in service settings. This paper contributes to the existing theory by investigating the direct and indirect effects of goal orientations on the creativity and performance of retail employees. The authors propose a framework depicting the relationships between goal orientations and employee creativity and performance, including the intervening effects of self-efficacy and customer orientation. Design/methodology/approach: The study was conducted with retail frontline employees of a large retail bank in Portugal. The sample consists of 267 valid responses. Structural equations are used by applying the maximum likelihood method to test the conceptual framework. Findings: Results are broadly supportive of the hypotheses. Learning orientation is, directly and indirectly, related to creativity, but only indirectly to performance. As to performance orientation, it is indirectly related to creativity through self-efficacy and customer orientation, and directly as well as indirectly, to performance. The authors investigate the extent to which the effects of goal orientations on creativity and performance are mediated by self-regulatory mechanisms, namely self-efficacy, and customer orientation. Originality/value: The results recognize that learning and performance goals are neither mutually exclusive nor contradictory, which collide with past empirical evidence showing that learning goals are generally associated with more favorable outcomes and performance goals with more negative or equivocal ones. These outcomes underscore the need and relevance for managers to foster both goal orientations to promote the creativity and performance of retail employees, representing a particularly salient issue in retail businesses characterized by significant interpersonal interactions.info:eu-repo/semantics/acceptedVersio

Functionalization of CNTS with maleic anhydride

The outstanding properties of carbon nanotubes (CNTs) [1] are mainly related with their unique structural features. However, the high π-π staking between the tubes is a major drawback for their manipulation and interaction with other materials. Chemical functionalization has been used as a convenient tool to improve their performance in various applications [2]. The work reports the functionalization of multi-wall carbon nanotubes (MWCNTs) with maleic anhydride via a Diels-Alder addition reaction, performed in dimethyl sulfoxide (190 ºC) or 2-chorotoluene (150 ºC) for 24 hours. The product was characterized by thermogravimetric analysis (TGA) and the weight loss at 800 ºC was 11.9 and 3.7 % respectively. Potentiometric titration suggests that CNTs modified at 190 ºC remain predominantly in the anhydride form, while for CNTs modified at 150 ºC, the extent of hydrolysis is approximately 40 %. Maleic anhydride was also reacted with a model compound (anthracene) in dimethyl sulfoxide (190 ºC) and the hydrolysis of the product (0.025 mmol in 650 µL of DMSO-d6) was followed by 1H RMN upon addition of 0.166 mmol of DCl (40 % weight in D2O) (graphic in figure). The anhydride 1 was easily regenerated from the dicarboxylic acid 2 when this compound was heated at 185 ºC for 10 minutes. A similar behavior is expected for the modified CNTs.Fundação para a Ciência e Tecnologi

Estudo preliminar da actividade antimicrobiana das folhas de cydonia oblonga miller

O marmelo é reconhecido como uma importante fonte de compostos promotores da saúde sendo que a actividade antimicrobiana dos extractos da sua polpa, casca e sementes foi já avaliada. Não existem porém estudos da actividade antimicrobiana das folhas de marmeleiro. Este estudo preliminar teve como objectivo determinar a actividade dos seus extractos metanólicos. Concluiu-se que os extractos testados não apresentam actividade em E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp pelo que novos extractos devem ser preparados sendo posteriormente avaliados. Quince fruit is recognized an important source of health promoting compounds being the antimicrobial activities of the quince pulp, peel grape and seed extracts already evaluated. No results are known for quince leaves antimicrobial activity. This preliminary work intended to determine the activity of quince leaves methanolic extracts. These had no antimicrobial activity either against E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp and new extracts must be prepared and evaluated

Estudo preliminar da actividade antimicrobiana das folhas de cydonia oblonga miller

O marmelo é reconhecido como uma importante fonte de compostos promotores da saúde sendo que a actividade antimicrobiana dos extractos da sua polpa, casca e sementes foi já avaliada. Não existem porém estudos da actividade antimicrobiana das folhas de marmeleiro. Este estudo preliminar teve como objectivo determinar a actividade dos seus extractos metanólicos. Concluiu-se que os extractos testados não apresentam actividade em E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp pelo que novos extractos devem ser preparados sendo posteriormente avaliados. Quince fruit is recognized an important source of health promoting compounds being the antimicrobial activities of the quince pulp, peel grape and seed extracts already evaluated. No results are known for quince leaves antimicrobial activity. This preliminary work intended to determine the activity of quince leaves methanolic extracts. These had no antimicrobial activity either against E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp and new extracts must be prepared and evaluated

On a class of 4D Kahler bases and AdS_5 supersymmetric Black Holes

We construct a class of toric Kahler manifolds, M_4, of real dimension four, a subset of which corresponds to the Kahler bases of all known 5D asymptotically AdS_5 supersymmetric black-holes. In a certain limit, these Kahler spaces take the form of cones over Sasaki spaces, which, in turn, are fibrations over toric manifolds of real dimension two. The metric on M_4 is completely determined by a single function H(x), which is the conformal factor of the two dimensional space. We study the solutions of minimal five dimensional gauged supergravity having this class of Kahler spaces as base and show that in order to generate a five dimensional solution H(x) must obey a simple sixth order differential equation. We discuss the solutions in detail, which include all known asymptotically AdS_5 black holes as well as other spacetimes with non-compact horizons. Moreover we find an infinite number of supersymmetric deformations of these spacetimes with less spatial isometries than the base space. These deformations vanish at the horizon, but become relevant asymptotically.Comment: 34 pages, 3 figures. v2: formula (8.35) and other minor typos corrected; references added; accepted for publication in JHE

Teorias discursivas em diálogo: perspetivas e análises

O volume inclui quatro capítulos: "Texto e contexto: Que relações?", de Carlos A. M. Gouveia e Joana Vieira Santos; "Classificações textuais e documentos programáticos de Português", de Paulo Nunes da Silva, Luís Filipe Barbeiro e Fausto Caels; "Géneros escolares e aprendizagens", de Luís Filipe Barbeiro, Fausto Caels e Paulo Nunes da Silva; e "Reconto e relato: Propostas de análise de narrativas orais em contexto escolar", de Carla Marques e Célia BarbeiroFinanciado por fundos nacionais através da FCT – Fundação para a Ciência e a Tecnologia, I.P., no âmbito do projeto UID/04887/2020info:eu-repo/semantics/publishedVersio

Using noninvasive metagenomics to characterize viral communities from wildlife

Microbial communities play an important role in organismal and ecosystem health. While high‐throughput metabarcoding has revolutionized the study of bacterial communities, generating comparable viral communities has proven elusive, particularly in wildlife samples where the diversity of viruses and limited quantities of viral nucleic acid present distinctive challenges. Metagenomic sequencing is a promising solution for studying viral communities, but the lack of standardized methods currently precludes comparisons across host taxa or localities. Here, we developed an untargeted shotgun metagenomic sequencing protocol to generate comparable viral communities from noninvasively collected faecal and oropharyngeal swabs. Using samples from common vampire bats (Desmodus rotundus), a key species for virus transmission to humans and domestic animals, we tested how different storage media, nucleic acid extraction procedures and enrichment steps affect viral community detection. Based on finding viral contamination in foetal bovine serum, we recommend storing swabs in RNAlater or another nonbiological medium. We recommend extracting nucleic acid directly from swabs rather than from supernatant or pelleted material, which had undetectable levels of viral RNA. Results from a low‐input RNA library preparation protocol suggest that ribosomal RNA depletion and light DNase treatment reduce host and bacterial nucleic acid, and improve virus detection. Finally, applying our approach to twelve pooled samples from seven localities in Peru, we showed that detected viral communities saturated at the attained sequencing depth, allowing unbiased comparisons of viral community composition. Future studies using the methods outlined here will elucidate the determinants of viral communities across host species, environments and time

Epidemiology and biology of a herpesvirus in rabies endemic vampire bat populations

Rabies is a viral zoonosis transmitted by vampire bats across Latin America. Substantial public health and agricultural burdens remain, despite decades of bats culls and livestock vaccinations. Virally vectored vaccines that spread autonomously through bat populations are a theoretically appealing solution to managing rabies in its reservoir host. We investigate the biological and epidemiological suitability of a vampire bat betaherpesvirus (DrBHV) to act as a vaccine vector. In 25 sites across Peru with serological and/or molecular evidence of rabies circulation, DrBHV infects 80–100% of bats, suggesting potential for high population-level vaccine coverage. Phylogenetic analysis reveals host specificity within neotropical bats, limiting risks to non-target species. Finally, deep sequencing illustrates DrBHV super-infections in individual bats, implying that DrBHV-vectored vaccines might invade despite the highly prevalent wild-type virus. These results indicate DrBHV as a promising candidate vector for a transmissible rabies vaccine, and provide a framework to discover and evaluate candidate viral vectors for vaccines against bat-borne zoonoses