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## A PDF based digital signed document format for interoperable institutional structured data integrity

Luís A. Maia; Luís M. Valente; Manuel E. Correia; Lígia M. Ribeiro; Luís Antunes
Tipo: Artigo de Revista Científica
Português
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It is widely recognized that information systems constitute a key tool for the overall performance improvement of administrative tasks in academic institutions. However at their genesis lies a latent promise of a paper-less environment that stays most of the time unfulfilled due to the lack of appropriate digital document integrity and accountability mechanisms. Academic institutions are thus most of the time still relying on traditional security trust methods based on paper documents for signing and archiving critical documents. While this method delivers an inefficient, inconvenient and costly workflow, it is still a common method to provide some sort of workable verifiable integrity and accountability that is still considered to be appropriate for the digital data that is being managed by the institutional information systems. Paper based documents have been relying on physical signatures and stamping policies and the physical properties of paper and ink for their integrity and authenticity for a long time. However, the evaluation of a paper document signature or stamp is not a straight forward process. It requires the recipient to have a notarized copy of the signer#8217;s signature or stamp for comparison and requires handwritten signature evaluation training that is often beyond the scope of many office employee training. This can lead to situations where the level of credibility and integrity of paper based document is not adequate and makes the verification process entirely dependent on the administrative staff capacity of recognizing hand written signatures and puts too much trust on physical stamps...

## A gestão da produção informacional: o formato PDF e a comunicação via email

Oliveira, Hugo Azevedo de; Pinto, Maria Manuela
Tipo: Artigo de Revista Científica
Português
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This article presents some results of the analysis of two practical cases of informational production considered priorities in the context of trustworthy digital repository structuration in a Portuguese public administration institution. This is an Information Science (IS) study in the field of Information Management (IM), assuming the function of information preservation as an IM variable under a systemic perspective.It addresses, on the one hand, the adoption of formats normalization as a preservation strategy based on the adoption of PDF/A, a work that has been carried out in recent years in the institution, and on the other hand, tasks and specifications that should be developed regarding the management and preservation of informational production communicated via email. It is characterized PDF format, variants and application contexts, and it is defined and described how works the technology of email, the need and importance to be considered in IM processes. An approach that involves the development of an email management policy, the email management process throughout its life cycle, assuming its preservation in a perspective of continuous access and use, only possible if its effectively integrated into the management processes of organizational information system...

## Comparative Antimicrobial Characterization of LBM415 (NVP PDF-713), a New Peptide Deformylase Inhibitor of Clinical Importance

Fritsche, Thomas R.; Sader, Helio S.; Cleeland, Roy; Jones, Ronald N.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
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LBM415 (NVP PDF-713) is the first member of the peptide deformylase (PDF) inhibitor class being developed for clinical trials as a parenteral and oral agent for treatment of community-acquired respiratory tract disease and serious infections caused by antimicrobial-resistant gram-positive cocci. In this study susceptibility testing results from 1,306 recent clinical isolates selected to overrepresent resistance trends among the species were summarized. All staphylococci (153 strains; MIC at which 90% of isolates were inhibited [MIC90], 2 μg/ml), Streptococcus pneumoniae (170 strains; MIC90, 1 μg/ml), other streptococci (150 strains; MIC90, 1 μg/ml), enterococci (104 strains; MIC90, 4 μg/ml), Moraxella catarrhalis (103 strains; MIC90, 0.5 μg/ml), and Legionella pneumophila (50 strains; MIC90, 0.12 μg/ml) were inhibited at ≤8 μg of LBM415/ml, as were 97% of Haemophilus influenzae isolates (300 strains; MIC90, 4 to 8 μg/ml). Among other bacterial groups, 100% of gram-positive and -negative anaerobes, including 22 Bacteroides spp. strains (31 strains total; MIC90, 1 μg/ml), were inhibited by ≤4 μg/ml, whereas Enterobacteriaceae (112 strains) and most nonfermentative bacilli (107 strains) were not inhibited at readily achievable concentrations. The compound was found to have a dominantly bacteriostatic action...

## Autoreceptor Modulation of Peptide/Neurotransmitter Co-release from PDF Neurons Determines Allocation of Circadian Activity in Drosophila

Choi, Charles; Cao, Guan; Tanenhaus, Anne K.; McCarthy, Ellena v.; Jung, Misun; Schleyer, William; Shang, Yuhua; Rosbash, Michael; Yin, Jerry C.P.; Nitabach, Michael N.
Tipo: Artigo de Revista Científica
Português
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Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral ventral pacemaker neurons (LNvs) that secrete the neuropeptide PDF (Pigment Dispersing Factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity. While LNvs also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here we show that (1) PDFR activation in LNvs shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions and (2) this shift is mediated by stimulation of the Ga,s-cAMP pathway and a consequent change in PDF/neurotransmitter co-release from the LNvs. These results suggest a novel mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits.

## Serotonin and the Neuropeptide PDF Initiate and Extend Opposing Behavioral States in C. elegans

Flavell, Steven W.; Pokala, Navin; Macosko, Evan Z.; Albrecht, Dirk R.; Larsch, Johannes; Bargmann, Cornelia I.
Tipo: Artigo de Revista Científica
Português
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Foraging animals have distinct exploration and exploitation behaviors that are organized into discrete behavioral states. Here we characterize a neuromodulatory circuit that generates long-lasting roaming and dwelling states in Caenorhabditis elegans. We find that two opposing neuromodulators, serotonin and the neuropeptide pigment dispersing factor (PDF), each initiate and extend one behavioral state. Serotonin promotes dwelling states through the MOD-1 serotonin-gated chloride channel. The spontaneous activity of serotonergic neurons correlates with dwelling behavior, and optogenetic modulation of the critical MOD-1-expressing targets induces prolonged dwelling states. PDF promotes roaming states through a Gαs-coupled PDF receptor; optogenetic activation of cAMP production in PDF receptor-expressing cells induces prolonged roaming states. The neurons that produce and respond to each neuromodulator form a distributed circuit orthogonal to the classical wiring diagram, with several essential neurons that express each molecule. The slow temporal dynamics of this neuromodulatory circuit supplement fast motor circuits to organize long-lasting behavioral states.

## The Drosophila neuropeptides PDF and sNPF have opposing electrophysiological and molecular effects on central neurons

Vecsey, Christopher G.; Pírez, Nicolás; Griffith, Leslie C.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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Neuropeptides have widespread effects on behavior, but how these molecules alter the activity of their target cells is poorly understood. We employed a new model system in Drosophila melanogaster to assess the electrophysiological and molecular effects of neuropeptides, recording in situ from larval motor neurons, which transgenically express a receptor of choice. We focused on two neuropeptides, pigment-dispersing factor (PDF) and small neuropeptide F (sNPF), which play important roles in sleep/rhythms and feeding/metabolism. PDF treatment depolarized motor neurons expressing the PDF receptor (PDFR), increasing excitability. sNPF treatment had the opposite effect, hyperpolarizing neurons expressing the sNPF receptor (sNPFR). Live optical imaging using a genetically encoded fluorescence resonance energy transfer (FRET)-based sensor for cyclic AMP (cAMP) showed that PDF induced a large increase in cAMP, whereas sNPF caused a small but significant decrease in cAMP. Coexpression of pertussis toxin or RNAi interference to disrupt the G-protein Gαo blocked the electrophysiological responses to sNPF, showing that sNPFR acts via Gαo signaling. Using a fluorescent sensor for intracellular calcium, we observed that sNPF-induced hyperpolarization blocked spontaneous waves of activity propagating along the ventral nerve cord...

## PDF neuron firing phase-shifts key circadian activity neurons in Drosophila

Guo, Fang; Cerullo, Isadora; Chen, Xiao; Rosbash, Michael
Fonte: eLife Sciences Publications, Ltd Publicador: eLife Sciences Publications, Ltd
Tipo: Artigo de Revista Científica
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Our experiments address two long-standing models for the function of the Drosophila brain circadian network: a dual oscillator model, which emphasizes the primacy of PDF-containing neurons, and a cell-autonomous model for circadian phase adjustment. We identify five different circadian (E) neurons that are a major source of rhythmicity and locomotor activity. Brief firing of PDF cells at different times of day generates a phase response curve (PRC), which mimics a light-mediated PRC and requires PDF receptor expression in the five E neurons. Firing also resembles light by causing TIM degradation in downstream neurons. Unlike light however, firing-mediated phase-shifting is CRY-independent and exploits the E3 ligase component CUL-3 in the early night to degrade TIM. Our results suggest that PDF neurons integrate light information and then modulate the phase of E cell oscillations and behavioral rhythms. The results also explain how fly brain rhythms persist in constant darkness and without CRY.

## GW182 controls Drosophila circadian behavior and PDF-Receptor signaling

Zhang, Yong; Emery, Patrick
Tipo: Artigo de Revista Científica
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The neuropeptide PDF is crucial for Drosophila circadian behavior: it keeps circadian neurons synchronized. Here, we identify GW182 as a key regulator of PDF signaling. Indeed, GW182 downregulation results in phenotypes similar to those of Pdf and Pdf-receptor (Pdfr) mutants. gw182 genetically interacts with Pdfr and cAMP signaling, which is essential for PDFR function. GW182 mediates miRNA-dependent gene silencing through its interaction with AGO1. Consistently, GW182's AGO1 interaction domain is required for GW182's circadian function. Moreover, our results indicate that GW182 modulates PDFR signaling by silencing the expression of the cAMP phosphodiesterase DUNCE. Importantly, this repression is under photic control, and GW182 activity level - which is limiting in circadian neurons - influences the responses of the circadian neural network to light. We propose that GW182's gene silencing activity functions as a rheostat for PDFR signaling, and thus profoundly impacts the circadian neural network and its response to environmental inputs.

## PDF modeling of turbulent flows on unstructured grids

Bakosi, J.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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In probability density function (PDF) methods of turbulent flows, the joint PDF of several flow variables is computed by numerically integrating a system of stochastic differential equations for Lagrangian particles. A mathematically exact treatment of advection, viscous effects and arbitrarily complex chemical reactions is possible; these processes are treated without closure assumptions. A set of algorithms is proposed to provide an efficient solution of the PDF transport equation modeling the joint PDF of turbulent velocity, frequency and concentration of a passive scalar in geometrically complex configurations. An unstructured Eulerian grid is employed to extract Eulerian statistics, to solve for quantities represented at fixed locations of the domain and to track particles. All three aspects regarding the grid make use of the finite element method. Compared to hybrid methods, the current methodology is stand-alone, therefore it is consistent both numerically and at the level of turbulence closure without the use of consistency conditions. Several newly developed algorithms are described that facilitate the numerical solution in complex flow geometries, including a stabilized mean-pressure projection scheme, the estimation of conditional and unconditional Eulerian statistics and their derivatives from stochastic particle fields...

## Detecting Table Region in PDF Documents Using Distant Supervision

Fan, Miao; Kim, Doo Soon
Tipo: Artigo de Revista Científica
Português
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Superior to state-of-the-art approaches which compete in table recognition with 67 annotated government reports in PDF format released by {\it ICDAR 2013 Table Competition}, this paper contributes a novel paradigm leveraging large-scale unlabeled PDF documents to open-domain table detection. We integrate the paradigm into our latest developed system ({\it PdfExtra}) to detect the region of tables by means of 9,466 academic articles from the entire repository of {\it ACL Anthology}, where almost all papers are archived by PDF format without annotation for tables. The paradigm first designs heuristics to automatically construct weakly labeled data. It then feeds diverse evidences, such as layouts of documents and linguistic features, which are extracted by {\it Apache PDFBox} and processed by {\it Stanford NLP} toolkit, into different canonical classifiers. We finally use these classifiers, i.e. {\it Naive Bayes}, {\it Logistic Regression} and {\it Support Vector Machine}, to collaboratively vote on the region of tables. Experimental results show that {\it PdfExtra} achieves a great leap forward, compared with the state-of-the-art approach. Moreover, we discuss the factors of different features, learning models and even domains of documents that may impact the performance. Extensive evaluations demonstrate that our paradigm is compatible enough to leverage various features and learning models for open-domain table region detection within PDF files.

## Heavy-quark mass dependence in global PDF analyses and 3- and 4-flavour parton distributions

Martin, A. D.; Stirling, W. J.; Thorne, R. S.; Watt, G.
Tipo: Artigo de Revista Científica
Português
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We study the sensitivity of our recent MSTW 2008 NLO and NNLO PDF analyses to the values of the charm- and bottom-quark masses, and we provide additional public PDF sets for a wide range of these heavy-quark masses. We quantify the impact of varying m_c and m_b on the cross sections for W, Z and Higgs production at the Tevatron and the LHC. We generate 3- and 4-flavour versions of the (5-flavour) MSTW 2008 PDFs by evolving the input PDFs and alpha_S determined from fits in the 5-flavour scheme, including the eigenvector PDF sets necessary for calculation of PDF uncertainties. As an example of their use, we study the difference in the Z total cross sections at the Tevatron and LHC in the 4- and 5-flavour schemes. Significant differences are found, illustrating the need to resum large logarithms in Q^2/m_b^2 by using the 5-flavour scheme. The 4-flavour scheme is still necessary, however, if cuts are imposed on associated (massive) b-quarks, as is the case for the experimental measurement of Z b bbar production and similar processes.; Comment: 40 pages, 11 figures. Grids can be found at http://projects.hepforge.org/mstwpdf/ and in LHAPDF V5.8.4. v2: version published in EPJC

## Measuring the History of Cosmic Reionization using the 21-cm PDF from Simulations

Ichikawa, Kazuhide; Barkana, Rennan; Iliev, Ilian T.; Mellema, Garrelt; Shapiro, Paul
Tipo: Artigo de Revista Científica
Português
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The 21-cm PDF (i.e., distribution of pixel brightness temperatures) is expected to be highly non-Gaussian during reionization and to provide important information on the distribution of density and ionization. We measure the 21-cm PDF as a function of redshift in a large simulation of cosmic reionization and propose a simple empirical fit. Guided by the simulated PDF, we then carry out a maximum likelihood analysis of the ability of upcoming experiments to measure the shape of the 21-cm PDF and derive from it the cosmic reionization history. Under the strongest assumptions, we find that upcoming experiments can measure the reionization history in the mid to late stages of reionization to 1-10% accuracy. Under a more flexible approach that allows for four free parameters at each redshift, a similar accuracy requires the lower noise levels of second-generation 21-cm experiments.; Comment: 13 pages, 16 figures, submitted to MNRAS

## Joint PDF modelling of turbulent flow and dispersion in an urban street canyon

Bakosi, J.; Franzese, P.; Boybeyi, Z.
Tipo: Artigo de Revista Científica
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The joint probability density function (PDF) of turbulent velocity and concentration of a passive scalar in an urban street canyon is computed using a newly developed particle-in-cell Monte Carlo method. Compared to moment closures, the PDF methodology provides the full one-point one-time PDF of the underlying fields containing all higher moments and correlations. The small-scale mixing of the scalar released from a concentrated source at the street level is modelled by the interaction by exchange with the conditional mean (IECM) model, with a micro-mixing time scale designed for geometrically complex settings. The boundary layer along no-slip walls (building sides and tops) is fully resolved using an elliptic relaxation technique, which captures the high anisotropy and inhomogeneity of the Reynolds stress tensor in these regions. A less computationally intensive technique based on wall functions to represent boundary layers and its effect on the solution are also explored. The calculated statistics are compared to experimental data and large-eddy simulation. The present work can be considered as the first example of computation of the full joint PDF of velocity and a transported passive scalar in an urban setting. The methodology proves successful in providing high level statistical information on the turbulence and pollutant concentration fields in complex urban scenarios.; Comment: Accepted in Boundary-Layer Meteorology...

## An SMLD joint PDF model for turbulent non-premixed combustion using the flamelet progress-variable approach

Coclite, Alessandro; Pascazio, Giuseppe; De Palma, Pietro; Cutrone, Luigi; Ihme, Matthias
Tipo: Artigo de Revista Científica
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This paper provides an improved flamelet/progress variable (FPV) model for the simulation of turbulent combustion, employing the statistically most likely distribution (SMLD) approach for the joint probability density function (PDF) of the mixture fraction, Z, and of the progress parameter, {\Lambda} . Steady-state FPV models are built presuming the func- tional shape of the joint PDF of Z and {\Lambda} in order to evaluate Favre-averages of thermody- namic quantities. The mixture fraction is widely assumed to behave as a passive scalar with a mono-modal behaviour modelled by a \b{eta} -distribution. Moreover, under the hypothesis that Z and {\Lambda} are statistically independent, the joint PDF coincides with the product of the two marginal PDFs. In this work we discuss these two constitutive hypotheses. The proposed model evaluates the most probable joint distribution of Z and {\Lambda} , relaxing some crucial as- sumption on their statistical behaviour. This provides a more general model in the context of FPV approach and an effective tool to verify the adequateness of widely used hypotheses. The model is validated versus experimental data of well-known test cases, namely, the San- dia flames. The results are also compared with those obtained by the standard FPV approach...

## Feasibility of top quark measurements at LHCb and constraints on the large-$x$ gluon PDF

Gauld, Rhorry
Tipo: Artigo de Revista Científica
Português
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The forward LHCb acceptance opens interesting possibilities of studying precision Standard Model hard processes in a kinematical region beyond the reach of ATLAS and CMS. In this paper we perform a feasibility study for cross-section measurements of top quark pairs with the LHCb detector, with an analysis of signal and background rates for selected final states, and determine the potential precision achievable at $\sqrt{s} =$ 7 and 14~TeV. We then study the dependence of theoretical uncertainties on the pseudorapidity distribution of top quarks produced in pair production at NLO, and observe that a cross-section measurement at high pseudorapidity has enhanced sensitivity to probe the high-$x$ gluon PDF as compared to measurements in the central-region. Based on simulated pseudodata, the impact of a 14~TeV cross-section measurement on the gluon PDF and charge asymmetry is quantified.; Comment: 25 pages, 14 figures, 8 tables. Extended PDF analysis to include ABM11 5flv nlo. Added summary plots of LHCb cross-sections. Include shift of gluon PDF central value for CT10, NNPDF sets assuming different pseudodata values. Matches version to be published in JHEP

## The impact of PDF uncertainties on the measurement of the W boson mass at the Tevatron and the LHC

Bozzi, G.; Rojo, J.; Vicini, A.
Tipo: Artigo de Revista Científica
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We study at a quantitative level the impact of the uncertainties on the value of the W boson mass measured at hadron colliders due to: the proton parton distribution functions (PDFs), the value of the strong coupling constant alpha_S and the value of the charm mass used in the PDF determination. The value of the W boson mass is extracted, by means of a template fit technique, from the lepton-pair transverse mass distribution measured in the charged current Drell-Yan process. We study the determination of M_W at the Tevatron and at the LHC with 7 and 14 TeV of center-of-mass energy in a realistic experimental setup. The analysis has been done at the Born level using the event generator HORACE and at NLO-QCD using the event generators DYNNLO and ResBos. We consider the three global PDF sets, CTEQ6.6, MSTW2008 and NNPDF2.1. We estimate that the total PDF uncertainty on M_W is below 10 MeV both at the Tevatron and at the LHC for all energies and final states. We conclude that PDF uncertainties do not challenge a measurement of the W boson mass at the level of 10 MeV accuracy.; Comment: 22 pages, 14 figures

## Precoder Design for Multi-antenna Partial Decode-and-Forward (PDF) Cooperative Systems with Statistical CSIT and MMSE-SIC Receivers

Chiu, Eddy; Lau, Vincent K. N.; Zhang, Shunqing; Mok, Bao S. M.
Tipo: Artigo de Revista Científica
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Cooperative communication is an important technology in next generation wireless networks. Aside from conventional amplify-and-forward (AF) and decode-and-forward (DF) protocols, the partial decode-and-forward (PDF) protocol is an alternative relaying scheme that is especially promising for scenarios in which the relay node cannot reliably decode the complete source message. However, there are several important issues to be addressed regarding the application of PDF protocols. In this paper, we propose a PDF protocol and MIMO precoder designs at the source and relay nodes. The precoder designs are adapted based on statistical channel state information for correlated MIMO channels, and matched to practical minimum mean-square-error successive interference cancelation (MMSE-SIC) receivers at the relay and destination nodes. We show that under similar system settings, the proposed MIMO precoder design with PDF protocol and MMSE-SIC receivers achieves substantial performance enhancement compared with conventional baselines.

## The impact of PDF and alphas uncertainties on Higgs Production in gluon fusion at hadron colliders

Demartin, Federico; Forte, Stefano; Mariani, Elisa; Rojo, Juan; Vicini, Alessandro
Tipo: Artigo de Revista Científica
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We present a systematic study of uncertainties due to parton distributions and the strong coupling on the gluon-fusion production cross section of the Standard Model Higgs at the Tevatron and LHC colliders. We compare procedures and results when three recent sets of PDFs are used, CTEQ6.6, MSTW08 and NNPDF1.2, and we discuss specifically the way PDF and strong coupling uncertainties are combined. We find that results obtained from different PDF sets are in reasonable agreement if a common value of the strong coupling is adopted. We show that the addition in quadrature of PDF and alphas uncertainties provides an adequate approximation to the full result with exact error propagation. We discuss a simple recipe to determine a conservative PDF+alphas uncertainty from available global parton sets, and we use it to estimate this uncertainty on the given process to be about 10% at the Tevatron and 5% at the LHC for a light Higgs.; Comment: 29 pages, 13 figures

## La accesibilidad potencial y real del formato pdf : análisis de diarios digitales españoles

Voces Merayo, Ramón; Codina Bonilla, Lluís
Tipo: Artigo de Revista Científica Formato: application/pdf