575 research outputs found

    Computing coset leaders and leader codewords of binary codes

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    In this paper we use the Gr\"obner representation of a binary linear code C\mathcal C to give efficient algorithms for computing the whole set of coset leaders, denoted by CL(C)\mathrm{CL}(\mathcal C) and the set of leader codewords, denoted by L(C)\mathrm L(\mathcal C). The first algorithm could be adapted to provide not only the Newton and the covering radius of C\mathcal C but also to determine the coset leader weight distribution. Moreover, providing the set of leader codewords we have a test-set for decoding by a gradient-like decoding algorithm. Another contribution of this article is the relation stablished between zero neighbours and leader codewords

    Síntesis y evaluación citotoxica de derivados halogenados y peracetylados de nucleósidos en celulas de cancer de mama

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    Objectives. To make the synthesis of halogenated derivatives on the nitrogenous base and their respective acyl ester and amide type derivatives for all hydroxyl and amine groups of the uridine and cytarabine nucleosides, and evaluate cytotoxicity against breast cancer cell line. Methods. First, it was accomplished the halogenation reaction on the 5-position of the nitrogenous base, subsequently, the ester and amide derivatives were performed for all hydroxyl and amine group present in the nucleosides. Besides, the uridine acetonide derivatives as prepared by acid catalysis. The products were characterized by nuclear magnetic resonance spectroscopy (1H RMN y 13C RMN) and mass spectrometry in positive mode by direct injection. Derivatives were evaluated in Chinese hamster ovary (CHO-K1) and human breast cancer (MCF-7) cell lines. Results. The four derivatives were obtained with chlorine and bromine for the uridine and cytarabine, respectively, their respective per-acetylated derivatives, the per-acetylated nucleoside and the uridine acetonide; the compounds were obtained with efficiency over 90%. The per-acetylated nucleosides and the halogenated and per-acetylated derivatives did not show inhibitory effects on cell viability in MCF-7 cell line. However, the per-acetylated and halogenated derivatives presented a higher cytotoxic activity than their respective per-acetylated nucleoside. The uridine 3’,4’-acetonide showed a significant cytotoxicity on both cell lines. Conclusions. The per-acetylated nucleoside, and the respective halogenated derivatives with chlorine and bromine were obtained with high yields, nevertheless, these compounds did not exhibit a significant anti-proliferative activity (p˂0.05), possibly due to a low intra-cellular activation.Objetivos: Sintetizar derivados halogenados sobre la base nitrogenada, sus respectivos derivados tipo éster o amida de todos los grupos hidroxilo y amina presentes en los nucleósidos uridina y citarabina, y evaluar su actividad citotóxica sobre una línea celular de cáncer de mama. Metodología: primero se realizó la reacción de halogenación en la posición 5 de la base nitrogenada, posteriormente se formaron los ésteres y amidas de todos los grupos hidroxilos y amino presentes en los nucleósidos. Además, se preparó el derivado acetónido con catálisis ácida. Los compuestos se caracterizaron por espectroscopía de resonancia magnética nuclear (RMN 1H y RMN 13C) y espectrometría de masas por inyección directa en modo positivo. Los derivados se evaluaron sobre líneas celulares de tumor de Ovario de Hámster Chino (CHO) y de cáncer de mamá (MCF-7). Resultados: Se obtuvieron 4 derivados mono-halogenados con cloro y bromo de la uridina y citarabina, respectivamente, sus respectivos derivados per-acetilados, los nucleósidos per-acetilados y el acetónido de la uridina; los compuestos se obtuvieron con rendimientos superiores a 90%. Los nucleósidos per-acetilados, y los derivados per-acetilados y halogenados no exhibieron una inhibición significativa de la viabilidad celular en ambas líneas celulares, sin embargo, de estos, los derivados per-acetilados y halogenados presentaron mayor actividad citotóxica que los respectivos nucleósidos per-acetilados. El derivado acetónido de la uridina mostró citotoxicidad significativa sobre ambas líneas celulares. Conclusiones: se obtuvieron los nucleósidos per-acetilados y los respectivos derivados clorados y bromados de estos, con rendimientos altos, sin embargo, estos compuestos no exhibieron una actividad anti-proliferativa significativa (p˂0,05), posiblemente debido a una baja activación intra-celular de los nucleósidos

    A Digitally Programmable Analog Quadrature Sine Oscillator for on-chip Lock-In Measurement Systems

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    This paper presents a CMOS 1.8V-180nm analog quadrature sine oscillator. Thanks to a custom 12-bit bidirectional DAC-based architecture, the frequency can be digitally programmed over two decades with high accuracy, making it suitable as the actuation system in low-cost high-performance embedded lock-in measurement systems

    A Digitally Programmable Active-RC Filter for On-Chip Portable Sensor Applications

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    An enhanced digital tuning approach for RC-active circuits is presented. Simulations of a 12-bit CMOS second-order filter provide a 11.46-bit effective resolution to linearly control the frequency over three decades with THD<-70 dB. Its low power, 0.5 mW, and low active area, 0.087 mm2, prove its suitability for on-chip sensing systems

    Nuevos Espacios Urbanos Para Nuevas Tendencias: Medicina Complementaria y Alternativa y Ciudades Medias Globales

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    Complementary and alternative medicine refers to the use and benefit of non-allopathic medicines, which is presently increasing in Western societies. This study, on one hand, shows the presence and the form that this new fashion among the population adopts. On the other hand, it shows the spatial distribution of the tendency in CAM. This refers to its distribution according to neighborhoods and metropolitan territories. For this purpose, the city of Seville, Spain, a middle European city present in the network of global cities, has been selected for this study. To show this sociological reality, quantitative methodology has been conducted within two years beginning from 2013 to 2014. The database that was created provided information about the offer of the CAM, specifically 100 different practices related with the complementary and alternative medicine of 450 Centers and professionals. This is with a total of 1338 number of answers

    Production of highly bioactive resveratrol analogues pterostilbene and piceatannol in metabolically engineered grapevine cell cultures

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    Summary Grapevine stilbenes, particularly trans-resveratrol, have a demonstrated pharmacological activity. Other natural stilbenes derived from resveratrol such as pterostilbene or piceatannol, display higher oral bioavailability and bioactivity than the parent compound, but are far less abundant in natural sources. Thus, to efficiently obtain these bioactive resveratrol derivatives, there is a need to develop new bioproduction systems. Grapevine cell cultures are able to produce large amounts of easily recoverable extracellular resveratrol when elicited with methylated cyclodextrins and methyl jasmonate. We devised this system as an interesting starting point of a metabolic engineering-based strategy to produce resveratrol derivatives using resveratrolconverting enzymes. Constitutive expression of either Vitis vinifera resveratrol O-methyltransferase (VvROMT) or human cytochrome P450 hydroxylase 1B1 (HsCYP1B1) led to pterostilbene or piceatannol, respectively, after the engineered cell cultures were treated with the aforementioned elicitors. Functionality of both gene products was first assessed in planta by Nicotiana benthamiana agroinfiltration assays, in which tobacco cells transiently expressed stilbene synthase and VvROMT or HsCYP1B1. Grapevine cell cultures transformed with VvROMT produced pterostilbene, which was detected in both intra- and extracellular compartments, at a level of micrograms per litre. Grapevine cell cultures transformed with HsCYP1B1 produced about 20 mg/L culture of piceatannol, displaying a sevenfold increase in relation to wild-type cultures, and reaching an extracellular distribution of up to 45% of total production. The results obtained demonstrate the feasibility of this novel system for the bioproduction of natural and more bioactive resveratrol derivatives and suggest new ways for the improvement of production yield

    A database and digital signal processing framework for the perceptual analysis of voice quality

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    Bermúdez de Alvear RM, Corral J, Tardón LJ, Barbancho AM, Fernández Contreras E, Rando Márquez S, Martínez-Arquero AG, Barbancho I. A database and digital signal processing framework for the perceptual analysis of voice quality. Pan European Voice Conferenc: PEVOC 11 Abstract Book. Aug. 31-Sept.2, 2015.Introduction. Clinical assessment of dysphonia relies on perceptual as much as instrumental methods of analysis [1]. The perceptual auditory analysis is potentially subject to several internal and external sources of bias [2]. Furthermore acoustic analyses which have been used to objectively characterize pathological voices are likely to be affected by confusion variables such as the signal processing or the hardware and software specifications [3]. For these reasons the poor correlation between perceptual ratings and acoustic measures remains to be a controversial matter [4]. The availability of annotated databases of voice samples is therefore of main importance for clinical and research purposes. Databases to perform digital processing of the vocal signal are usually built from English speaking subjects’ sustained vowels [5]. However phonemes vary from one language to another and to the best of our knowledge there are no annotated databases with Spanish sustained vowels from healthy or dysphonic voices. This work shows our first steps to fill in this gap. For the aim of aiding clinicians and researchers in the perceptual assessment of voice quality a two-fold objective was attained. On the one hand a database of healthy and disordered Spanish voices was developed; on the other an automatic analysis scheme was accomplished on the basis of signal processing algorithms and supervised learning machine techniques. Material and methods. A preliminary annotated database was created with 119 recordings of the sustained Spanish /a/; they were perceptually labeled by three experienced experts in vocal quality analysis. It is freely available under Links in the ATIC website (www.atic.uma.es). Voice signals were recorded using a headset condenser cardioid microphone (AKG C-544 L) positioned at 5 cm from the speaker’s mouth commissure. Speakers were instructed to sustain the Spanish vowel /a/ for 4 seconds. The microphone was connected to a digital recorder Edirol R-09HR. Voice signals were digitized at 16 bits with 44100 Hz sampling rate. Afterwards the initial and last 0.5 second segments were cut and the 3 sec. mid portion was selected for acoustic analysis. Sennheiser HD219 headphones were used by judges to perceptually evaluate voice samples. To label these recordings raters used the Grade-Roughness-Breathiness (GRB) perceptual scale which is a modified version of the original Hirano’s GRBAS scale, posteriorly modified by Dejonckere et al., [6]. In order to improve intra- and inter-raters’ agreement two types of modifications were introduced in the rating procedure, i.e. the 0-3 points scale resolution was increased by adding subintervals to the standard 0-3 intervals, and judges were provided with a written protocol with explicit definitions about the subintervals boundaries. By this way judges could compensate for the potential instability that might occur in their internal representations due to the perceptual context influence [7]. Raters’ perceptual evaluations were simultaneously performed by means of connecting the Sennheiser HD219 headphones to a multi-channel headphone preamp Behringer HA4700 Powerplay Pro-XL. The Yin algorithm [8] was selected as initial front-end to identify voiced frames and extract their fundamental frequency. For the digital processing of voice signals some conventional acoustic parameters [6] were selected. To complete the analysis the Mel-Frequency Cepstral Coefficients (MFCC) were further calculated because they are based on the auditory model and they are thus closer to the auditory system response than conventional features. Results. In the perceptual evaluation excellent intra-raters agreement and very good inter-raters agreement were achieved. During the supervised machine learning stage some conventional features were found to attain unexpected low performance in the classification scheme selected. Mel Frequency Cepstral Coefficients were promising for assorting samples with normal or quasi-normal voice quality. Discussion and conclusions. Despite it is still small and unbalanced the present annotated data base of voice samples can provide a basis for the development of other databases and automatic classification tools. Other authors [9, 10, 11] also found that modeling the auditory non-linear response during signal processing can help develop objective measures that better correspond with perceptual data. However highly disordered voices classification remains to be a challenge for this set of features since they cannot be correctly assorted by either conventional variables or the auditory model based measures. Current results warrant further research in order to find out the usability of other types of voice samples and features for the automatic classification schemes. Different digital processing steps could be used to improve the classifiers performance. Additionally other types of classifiers could be taken into account in future studies. Acknowledgment. This work was funded by the Spanish Ministerio de Economía y Competitividad, Project No. TIN2013-47276-C6-2-R has been done in the Campus de Excelencia Internacional Andalucía Tech, Universidad de Málaga. References [1] Carding PN, Wilson JA, MacKenzie K, Deary IJ. Measuring voice outcomes: state of the science review. The Journal of Laryngology and Otology 2009;123,8:823-829. [2] Oates J. Auditory-perceptual evaluation of disordered voice quality: pros, cons and future directions. Folia Phoniatrica et Logopaedica 2009;61,1:49-56. [3] Maryn et al. Meta-analysis on acoustic voice quality measures. J Acoust Soc Am 2009; 126, 5: 2619-2634. [4] Vaz Freitas et al. Correlation Between Acoustic and Audio-Perceptual Measures. J Voice 2015;29,3:390.e1 [5] “Multi-Dimensional Voice Program (MDVP) Model 5105. Software Instruction Manual”, Kay PENTAX, A Division of PENTAX Medical Company, 2 Bridgewater Lane, Lincoln Park, NJ 07035-1488 USA, November 2007. [6] Dejonckere PH, Bradley P, Clemente P, Cornut G, Crevier-Buchman L, Friedrich G, Van De Heyning P, Remacle M, Woisard V. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Comm. on Phoniatrics of the European Laryngological Society (ELS). Eur Arch Otorhinolaryngol 2001;258:77–82. [7] Kreiman et al. Voice Quality Perception. J Speech Hear Res 1993;36:21-4 [8] De Cheveigné A, Kawahara H. YIN, a fundamental frequency estimator for speech and music. J. Acoust. Soc. Amer. 202; 111,4:1917. [9] Shrivastav et al. Measuring breathiness. J Acoust Soc Am 2003;114,4:2217-2224. [10] Saenz-Lechon et al. Automatic Assessment of voice quality according to the GRBAS scale. Eng Med Biol Soc Ann 2006;1:2478-2481. [11] Fredouille et al. Back-and-forth methodology for objective voice quality assessment: from/to expert knowledge to/from automatic classification of dysphonia. EURASIP J Appl Si Pr 2009.Campus de Excelencia Internacional Andalucía Tech, Universidad de Málaga. Ministerio de Economía y Competitividad, Projecto No. TIN2013-47276-C6-2-R

    Osteocalcin in serum, saliva and gingival crevicular fluid : their relation with periodontal treatment outcome in postmenopausal women

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    Antecedentes. Los niveles de osteocalcina se han propuesto como marcador de la inhibición de la formación ósea. El propósito de este trabajo es determinar las concentraciones de osteocalcina en plasma, saliva y fluido crevicular correlacionándolo con el resultado del tratamiento periodontal en mujeres postmenopáusicas. Pacientes y métodos. El estudio se realizó en treinta y nueve mujeres postmenopáusicas (57.8 ±8.5 años de edad). El examen periodontal incluyó el control de placa, el sangrado al sondaje, la profundidad de sondaje (PS) y la pérdida de inserción (CAL). Se determinaron los niveles de osteocalcina en suero, saliva y fluido crevicular. A continuación se llevó a cabo el tratamiento periodontal. Pasados seis meses tras la primera cita se llevó a cabo un segundo examen periodontal. Resultados. Las medias de la PS y del CAL disminuyeron significativamente en el segundo examen periodontal en el grupo de mujeres con osteocalcina en suero < 10 ng/ml (15.8± 15.8% y 15.3± 21.2%, respectivamente; p < 0.05). La PS media disminuyó significativamente en el segundo exámen en los grupos con concentraciones de osteocalcina en saliva < 3 ng/ml (17.1± 15.9%; p < 0.05) y 3 ? 7 ng/ml (16.2 ± 18.1%; p < 0.05). Conclusiones. Los niveles bajos de osteocalcina en suero se asocian significativamente a un mayor porcentaje de disminución de la PS y del CAL tras el tratamiento periodontal en mujeres postmenopáusicas. Las bajas concentraciones de osteocalcina en saliva se asociaron significativamente a un mayor porcentaje de disminución de la PS

    Controlled manipulation of enzyme specificity through immobilization-induced flexibility constraints

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    It is thought that during immobilization enzymes, as dynamic biomolecules, may become distorted and this may alter their catalytic properties. However, the effects of different immobilization strategies on enzyme rigidity or flexibility and their consequences in specificity and stereochemistry at large scale has not been yet clearly evaluated and understood. This was here investigated by using as model an ester hydrolase, isolated from a bacterium inhabiting a karstic lake, with broad substrate spectrum (72 esters being converted; 61.5 U mg1^{-1} for glyceryl tripropionate) but initially non-enantiospecific. We found that the enzyme (7 nm × 4.4 nm × 4.2 nm) could be efficiently ionic exchanged inside the pores (9.3 nm under dry conditions) of amino-functionalized ordered mesoporous material (NH2_{2}-SBA-15), achieving a protein load of 48 mg g−1, and a specific activity of 4.5 ± 0.1 U mg1^{-1}. When the enzyme was site-directed immobilized through His interaction with an immobilized cationon the surface of two types of magnetic micro-particles through hexahistidine-tags, protein loads up to 10.2 μg g1^{-1} and specific activities of up to 29.9 ± 0.3 U mg1^{-1}, were obtained. We found that ionically exchanged enzyme inside pores of NH2-SBA-15 drastically narrowed the substrate range (17 esters), to an extent much higher than ionically exchanged enzyme on the surface of magnetic micro-particles (up to 61 esters). This is attributed to differences in surface chemistry, particle size, and substrate accessibility to the active site tunnel. Our results also suggested, for the first time, that immobilization of enzymes in pores of similar size may alter the enzyme structures and produce enzyme active centers with different configuration which promote stereochemical conversions in a manner different to those arising from surface immobilization, where the strength of the ionic exchange also has an influence. This was shown by demonstrating that when the enzyme was introduced inside pores with a diameter (under dry conditions) slightly higher than that of the enzyme crystal structure a biocatalyst enantiospecific for ethyl (R)-4-chloro-3-hydroxybutyrate was produced, a feature not found when using wider pores. By contrast, immobilization on the surface of ferromagnetic microparticles produced selective biocatalysts for methyl (S)-(+)-mandelate or methyl (S)-lactate depending on the functionalization. This study illustrates the benefits of extensive analysis of the substrate spectra to better understand the effects of different immobilization strategies on enzyme flexibility/rigidity, as well as substrate specificity and stereochemistry. Our results will help to design tunable materials and interfaces for a controlled manipulation of specificity and to transform non-enantiospecific enzymes into stereo-chemically substrate promiscuous biocatalysts capable of converting multiple chiral molecules
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