53 research outputs found
Application of full-reference video quality metrics in IPTV
Executing an accurate full-reference metric such as VQM can take minutes in an average computer for just one user. Therefore, it can be unfeasible to analyze all the videos received by users in an IPTV network for example consisting of 10.000 users using a single computer running the VQM metric. One solution can be to use a lightweight no-reference metrics in addition to the full-reference metric mentioned. Lightweight no-reference metrics can be used for discarding potential situations to evaluate because they are accurate enough for that task, and then the full-reference metric VQM can be used when more accuracy is needed. The work in this paper is focused on determining the maximum number of situations/users that can be analyzed simultaneously using the VQM metric in a computer with good performance. The full-reference metric is applied on the transmitter using a method specified in the recommendation ITU BT.1789. The best performance achieved was 112.8 seconds per process
The phonetics and phonology of intonational phrasing in Romance
Previous work on intonational phrasing in Romance has addressed the role of syntactic and prosodic structure on the placement of boundaries within SVO utterances (Elordieta et al. 2003, D'Imperio et al. to appear). A comparable database of 744 utterances was created for the 5 languages and varieties under study: Catalan (Cat), European Portuguese (both the Standard variety and the Northern variety spoken in Braga, SEP and NEP respectively), Italian (Neapolitan variety), and Spanish. The patterns of phrasing found were described and discussed, but a detailed inspection of the nature of the boundary cues was left undone. The present paper investigates the phonetics and phonology of the perceived phrasing boundaries established in previous work. We have three related goals: 1) to provide a typology of the boundary cues used by each language and determine their relative frequency; 2) to describe the phonetics of the dominant phonological choices to mark phrasing boundaries; 3) to better understand the extent to which Romance languages differ in their phonological boundary markers and/or in the phonetic instantiation of similar phonological choices.All the utterances previously classified as with and without a clear phrasing boundary were extracted from the compared Romance languages database. The utterances were perceptually and acoustically analysed. Resorting to spectrograms and F0 contours, a number of F0 and duration measurements were taken for each token. The results reported below are based on a random sample of 405 utterances. As shown in Table 1, prosodic breaks in Romance are usually marked by a High boundary tone. The preboundary stretch tends to be realised as a rise on the last stressed syllable, which extends to the boundary syllable (continuation rise) or forms a high plateau up to the boundary (sustained pitch). Italian deviates from the other languages due to its dominant use of sustained pitch. Other cues, such as pitch reset and preboundary lengthening are used by all languages but with different rates. In our database, the possibility of a Low boundary tone (in the EP case with a drop to the utterance base level) joins SEP, NEP and It against Cat and Sp. The phonetics of the H boundary tone points to the same language grouping, as shown by the scaling ratios in Table 2. However, It patterns with Cat and Sp with respect to pitch reset. Note that the height of the boundary tone is more extreme in the languages that make more use of it, in the same way that reset values are higher in the languages that more frequently resort to this boundary marker.Romance languages mainly signal phrasing boundaries with rises. Nevertheless, our data shows that not only the phonology (choice of pitch accent, boundary tone, phrasing level), but also the specific phonetics (scaling of boundary tone, scaling of pre- and post-boundary peaks) of the boundary gesture may differ, even among closely related languages
Evidence for 'soft' preplanning in tonal production: Initial scaling in Romance
International audienceIn this study, the scaling of utterance-initial f0 values and H initial peaks are examined in several Romance languages as a function of phrasal length, measured in number of pitch accents (1 to 3 pitch accents) and in number of syllables (3 to 15). The motivation for this study stems from contradictory claims in the literature regarding whether the height of the initial f0 values and peaks is governed by a look-ahead or preplanning mechanism. A total of ten speakers of five Romance language varieties (Catalan, Italian, Standard and Northern European Portuguese, and Spanish) read a total of 3720 declarative utterances (744 utterances per language) of varying length in number of pitch accents and syllables. The data reveal that the majority of speakers tend to begin higher in longer utterances. Results thus confirm recent findings about the need for a certain amount of global preplanning in tonal production ([1], [2]). The failure to find a correlation between phrase length and initial scaling for all speakers within languages shows that we are dealing with soft preplanning (in Liberman & Pierrehumbert's terms [3]), that is, an optional production mechanism that may be overridden by other tonal features
Using a Simple Cellular Assay to Map NES Motifs in Cancer-Related Proteins, Gain Insight into CRM1-Mediated NES Export, and Search for NES-Harboring Micropeptides
The nuclear export receptor CRM1 (XPO1) recognizes and binds specific sequence motifs termed nuclear export signals (NESs) in cargo proteins. About 200 NES motifs have been identified, but over a thousand human proteins are potential CRM1 cargos, and most of their NESs remain to be identified. On the other hand, the interaction of NES peptides with the “NES-binding groove” of CRM1 was studied in detail using structural and biochemical analyses, but a better understanding of CRM1 function requires further investigation of how the results from these in vitro studies translate into actual NES export in a cellular context. Here we show that a simple cellular assay, based on a recently described reporter (SRVB/A), can be applied to identify novel potential NESs motifs, and to obtain relevant information on different aspects of CRM1-mediated NES export. Using cellular assays, we first map 19 new sequence motifs with nuclear export activity in 14 cancer-related proteins that are potential CRM1 cargos. Next, we investigate the effect of mutations in individual NES-binding groove residues, providing further insight into CRM1-mediated NES export. Finally, we extend the search for CRM1-dependent NESs to a recently uncovered, but potentially vast, set of small proteins called micropeptides. By doing so, we report the first NES-harboring human micropeptides.This work was supported by grants from the Spanish Government MINECO-FEDER (SAF2014-57743-R), the Basque Country Government (IT1257-19) and the University of the Basque Country (UFI11/20), as well as a fellowship from the Basque Country Government (to M.S.)
DVB-T2 Performance in Presence of Multipath Laboratory Tests
Abstract-This paper presents the results of laboratory tests carried out to study the performance of DVB-T2 in presence of multipath in fixed reception with rooftop antenna. The typical multipath cause in this scenario is a Single Frequency Network (SFN) reception. A range of relative levels and delays between the main path and one echo are tested to obtain the C/N requirements for each case. DVB-T2 supports a large number of options that can be chosen to optimize the system. Some of those options (Pilot Patterns, Guard Interval Fraction, Rotated Constellations, FFT sizes) are tested to evaluate their performance. The results are compared with the simulation results available in the implementation guidelines for the extreme cases of Gaussian channel (no echo) and 0 dB echo channel (main path and echo at same level). Index Terms-DTV and broadband multimedia systems, Field trials and test results, Channel modeling and simulation, DVB-T2
Study of Micro-Samples from the Open-Air Rock Art Site of Cueva de la Vieja (Alpera, Albacete, Spain) for Assessing the Performance of a Desalination Treatment
In this work, some micro-samples belonging to the open-air rock art site of Cueva de la Vieja (Alpera, Albacete, Spain) were analysed. These samples were collected after and before a desalination treatment was carried out, with the aim of removing a whitish layer of concretion that affected the painted panel. The diagnostic study was performed to study the conservation state of the panel, and to then confirm the effectiveness of the treatment. Micro energy dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and X-ray diffraction were employed for the characterization of the degradation product as well as that of the mineral substrate and pigments. The micro-samples analysis demonstrated that the painted layer was settled on a dolomitic limestone with silicon aggregates and aluminosilicates as well as iron oxides. The whitish crust was composed by sulfate compounds such as gypsum (CaSO4·2H2O) with a minor amount of epsomite (MgSO4·7H2O). An extensive phenomenon of biological activity has been demonstrated since then in almost all of the samples that have been analysed, and the presence of calcium oxalates monohydrate (CaC2O4·H2O) and dehydrate (CaC2O4·2H2O) were found. The presence of both calcium oxalates probably favoured the conservation of the pictographs. In addition, some carotenoids pigments, scytonemin (C36H20N2O4), and astaxanthin (C40H52O4) were characterized both by Raman spectroscopy and by X-ray diffraction. Hematite was found as a pigment voluntarily used for the painting of the panels used in a mixture with hydroxyapatite and amorphous carbon. The results of the analyses of the samples taken after the cleaning treatment confirmed a substantial decrease in sulphate formation on the panel surfaceThis research was funded by the DEMORA project (Grant No. PID2020-113391GB-I00), funded by the Spanish Agency for Research (through the Spanish Ministry of Science and Innovation, MICINN, and the European Regional Development Fund, FEDER)
Graffiti Characterization Prior to Intervention in the Punta Begoña Galleries (Getxo, North of Spain): Raman and XRF Spectroscopy in the Service of Restoration
The Historical and Cultural Heritage of Punta Begoña Galleries in Getxo (Bizkaia, North of Spain) are currently in restoration after being abandoned for years. For that reason, many graffiti, which directly affect the wall paintings, appear on most of their walls. Moreover, several graffiti overlap each other, which makes their removal more difficult. For all these reasons, the chemical characterization of these pigments is a priority to optimize the cleaning and consolidation treatments of wall paintings. That being the case, an analysis based on Raman spectroscopy and X-ray fluorescence was carried out to obtain information to help conservators remove the graffiti without damaging the mural paintings and the support. Nevertheless, the first step, using X-ray fluorescence and Raman spectroscopy, involved the need for a database to compare the results and identify the compounds. Thus, different commercial inks were elementally and molecularly characterized to complete the existing databases. After this, an analysis of the inks was carried out that noted the presence of several organic pigments, such as phthalocyanines. Inorganic pigments such as titanium oxide were identified as well. After the analysis, the selection of the best removal process could be carried out to provide the most effective treatment, avoiding the “trial-and-error” classical practice.This work was supported by the DEMORA (Grant No. PID2020-113391GB-I00) project funded by the Spanish Agency for Research AEI (MICINN/FEDER-UE), and by the cooperation agreement between the University of the Basque Country and the City Council of Getxo (OTRI 2019-0316)
Looking for Novel Natural Gels to Improve Cleaning Methods for Bronze Leachates on Marble
Marble is one of the materials most susceptible to copper leaching, resulting in easily identifiable turquoise stains on the marble. This problem is particularly relevant when we are talking about marble structures of heritage value. For this reason, conservators look for cleaning materials that are specific to the structure to be treated without damaging the original surface. Materials such as agar have been studied for a long time. Agar creates a controlled water release system that adapts to the needs of conservators who seek the greatest possible cleanliness without damaging the material to be treated. To improve the cleaning, chelating agents such as EDTA are added to the agar composition. However, the microbiological growth and the damage it produces to the original material are disadvantages to take into account. In order to solve these problems, other natural materials with cleaning potential such as kudzu and konjac gels were studied in combination with other chelating agents such as citrate, oxalate, and gluconic acid. For the characterization and evaluation of copper cleaning, various analytical techniques were used, including Raman spectroscopy, colorimetry, X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). In this study, both konjac and kudzu emerged as promising alternatives to agar, revealing distinctive features such as simplified preparation methods and inherent antimicrobial properties. The EDTA chelator was found to be the most harmful for marble surfaces, as it extracted a greater amount of calcium from the marble during application of the gels doped with it. Citrate and gluconic acid have been identified as a promising substitute to prepare doped gels for the removal of copper stains. These compounds exhibit comparable or potentially superior cleaning capabilities than EDTA, with no negative side effects.This work has been supported by the project DEMORA (Grant PID2020-113391GB-I00) funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” (EU)
Identification of substrates for human deubiquitinating enzymes (DUBs): An up-to-date review and a case study for neurodevelopmental disorders
Similar to the reversal of kinase-mediated protein phosphorylation by phosphatases, deubiquitinating enzymes (DUBs) oppose the action of E3 ubiquitin ligases and reverse the ubiquitination of proteins. A total of 99 human DUBs, classified in 7 families, allow in this way for a precise control of cellular function and homeostasis. Ubiquitination regulates a myriad of cellular processes, and is altered in many pathological conditions. Thus, ubiquitination-regulating enzymes are increasingly regarded as potential candidates for therapeutic intervention. In this context, given the predicted easier pharmacological control of DUBs relative to E3 ligases, a significant effort is now being directed to better understand the processes and substrates regulated by each DUB. Classical studies have identified specific DUB substrate candidates by traditional molecular biology techniques in a case-by-case manner. Lately, single experiments can identify thousands of ubiquitinated proteins at a specific cellular context and narrow down which of those are regulated by a given DUB, thanks to the development of new strategies to isolate and enrich ubiquitinated material and to improvements in mass spectrometry detection capabilities. Here we present an overview of both types of studies, discussing the criteria that, in our view, need to be fulfilled for a protein to be considered as a high-confidence substrate of a given DUB. Applying these criteria, we have manually reviewed the relevant literature currently available in a systematic manner, and identified 650 high-confidence substrates of human DUBs. We make this information easily accessible to the research community through an updated version of the DUBase website (https://ehubio.ehu.eus/dubase/). Finally, in order to illustrate how this information can contribute to a better understanding of the physiopathological role of DUBs, we place a special emphasis on a subset of these enzymes that have been associated with neurodevelopmental disorders.This work was supported by Spanish MINECO grant SAF2016-76898-P to UM and by the University of the Basque Country (UPV/EHU), grant numbers US19/05 and COLAB19/18
Combined in situ XRF–LIBS analyses as a novel method to determine the provenance of central Mediterranean obsidians
This work presents a new calibration method for determining the provenance of obsidian artefacts based on the combined use of XRF and laser-induced breakdown spectroscopy (LIBS). At first, obsidian samples collected from the main Mediterranean sources were characterized using portable XRF and LIBS systems. After data treatment, elemental information was used to carry out principal component analysis (PCA) for each technique. Rb, Sr, Zr, Y and Fe elements, detected by using XRF, were found to be the key parameters enabling obsidians discrimination. Likewise, LIBS data helped differentiating the analysed patterns by the intensity of their main elemental components (Ca, Al, Mg and K). After selecting the key parameters detected by each technique, a new data matrix combining XRF and LIBS data was finally built. According to PCA results, the discrimination of Mediterranean sources based on combined XRF–LIBS data ensured a higher reliability over mono-analytical models, by increasing the Euclidean distance between sources projections over three-dimensional principal components plots. Knowing that the representativeness of elemental data could be compromised by the presence of superficial degradation products or deposition patinas, a shot-to-shot comparison of in-depth LIBS analyses is finally proposed as a method to disclose whether the spot under analysis was superficially contaminated or altered. Thus, the proposed strategy based on the combined use of portable XRF and LIBS spectrometers could be particularly useful for the in situ analysis of obsidian artefacts that underwent superficial alteration or could be covered by patina products.This work has been financially supported by the DEMORA project (Grant No. PID2020-113391GB-I00), funded by the Spanish Agency for Research (through the Spanish Ministry of Science and Innovation (Grant No. BIA2017-870´63-P), MICINN, and the European Regional Development Fund (Grant No. BIA2017-870´63-P), FEDER). I. Costantini gratefully acknowledges to the UPV/EHU for her postdoctoral contract.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature
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