Prediction of total and volatile acidity in red wines by Fourier-transform mid-infrared spectroscopy and iterative predictor weighting.

Fourier-transform mid-infrared (FT-MIR) spectroscopy, combined with partial least-squares (PLS) regression and IPW as feature selection method, was used to develop reduced-spectrum calibration models based on a few IR bands to provide near-real-time predictions of two key parameters for the characterization of finished red wines, which are essential from a quality assurance standpoint: total and volatile acidity. Separate PLS calibration models, correlating IR data (only considering those regions showing a high signal to noise ratio) with each response studied, were developed. Wavenumber selection was also performed applying IPW-PLS to take into account only significant predictors, in an attempt to improve the quality of the final models constructed. Using both PLS and IPW-PLS regression, prediction of the two responses modelled was performed with very high reliability, with RMSECV and RMSEP values on the order of 1% (comparable in terms of accuracy to the results provided by the respective reference analysis methods). An important advantage derived from the application of the IPW-PLS method had to do with the low number of original variables needed for modelling both total acidity (22 significant wavenumbers) and volatile acidity (only 11 selected predictor variables), in such a way that variable selection contributed to enhance the stability and parsimony properties of the final calibration models. The high quality of the calibration models proposed encourages the feasibility of implementing them as a fast and reliable tool in routine analysis for the determination of critical parameters for wine quality.

Monitoring of substrate and product concentrations in acetic fermentation processes for onion vinegar production by NIR spectroscopy: value addition to worthless onions.

Wastes and by-products of the onion-processing industry pose an increasing disposal and environmental problem and represent a loss of valuable sources of nutrients. The present study focused on the production of vinegar from worthless onions as a potential valorisation route which could provide a viable solution to multiple disposal and environmental problems, simultaneously offering the possibility of converting waste materials into a useful food-grade product and of exploiting the unique properties and health benefits of onions. This study deals specifically with the second and definitive step of the onion vinegar production process: the efficient production of vinegar from onion waste by transforming onion ethanol, previously produced by alcoholic fermentation, into acetic acid via acetic fermentation. Near-infrared spectroscopy (NIRS), coupled with multivariate calibration methods, has been used to monitor the concentrations of both substrates and products in acetic fermentation. Separate partial least squares (PLS) regression models, correlating NIR spectral data of fermentation samples with each kinetic parameter studied, were developed. Wavelength selection was also performed applying the iterative predictor weighting-PLS (IPW-PLS) method in order to only consider significant spectral features in each model development to improve the quality of the final models constructed. Biomass, substrate (ethanol) and product (acetic acid) concentration were predicted in the acetic fermentation of onion alcohol with high accuracy using IPW-PLS models with a root-mean-square error of the residuals in external prediction (RMSEP) lower than 2.5% for both ethanol and acetic acid, and an RMSEP of 6.1% for total biomass concentration (a very satisfactory result considering the relatively low precision and accuracy associated with the reference method used for determining the latter). Thus, the simple and reliable calibration models proposed in this study suggest that they could be implemented in routine applications to monitor and predict the key species involved in the acetic fermentation of onion alcohol, allowing the onion vinegar production process to be controlled in real time.

Experimental design approach to evaluate the impact of oak chips and micro-oxygenation on the volatile profile of red wines.

A chemometric strategy based on combining an experimental design approach and response surface methodology was applied to gain further knowledge on the influence of chip maceration and micro-oxygenation related factors (oxygen doses, chip doses, wood origin, toasting degree and maceration time) on the volatile profile of red wines during the accelerated ageing process. The results obtained indicated that the volatile profile of wines could be modulated by applying different combinations of factor conditions. Thus, these results would be used to obtain wines with specific volatile profiles that would lead to particular olfactory attributes according to consumers' preferences. Moreover, it was shown that combining wood from different origins helped enhance the quality of the elaborated wines. To the best of our knowledge, this is the first time that an experimental design methodology has been applied to simultaneously evaluate the influence of five different ageing parameters on the volatile profile of red wines.

Modulation of the phenolic composition and colour of red wines subjected to accelerated ageing by controlling process variables.

The aim of the present work was to evaluate the effect of the main factors conditioning accelerated ageing processes (oxygen dose, chip dose, wood origin, toasting degree and maceration time) on the phenolic and chromatic profiles of red wines by using a multivariate strategy based on experimental design methodology. The results obtained revealed that the concentrations of monomeric anthocyanins and flavan-3-ols could be modified through the application of particular experimental conditions. This fact was particularly remarkable since changes in phenolic profile were closely linked to changes observed in chromatic parameters. The main strength of this study lies in the possibility of using its conclusions as a basis to make wines with specific colour properties based on quality criteria. To our knowledge, the influence of such a large number of alternative ageing parameters on wine phenolic composition and chromatic attributes has not been studied previously using a comprehensive experimental design methodology.

Classification of Spanish extra virgin olive oils by data fusion of visible spectroscopic fingerprints and chemical descriptors.

The potential of visible fingerprints and physical-chemical parameters in combination with multivariate data analysis was examined to classify extra virgin olive oils (EVOOs) from different Spanish regions according to their geographical origin. Firstly, spectral and quality parameters matrices were processed separately and subsequently were joined to evaluate the effect of synergy on the information obtained from the different methodologies. Linear discriminant analysis (LDA) and partial least squares discriminant analysis (PLS-DA) were performed as classification methods. The results revealed a perfect discrimination between the defined categories after performing PLS-DA on the Fused matrix, reaching 100% of correct classifications and showed a clear improvement in the overall prediction rates (92.5%), so that the effect of synergy was confirmed. These accurate results emphasise the feasibility of the proposed strategy and encourage the development of similar approaches based on visible spectroscopy in olive oil quality and traceability determination.

Classification of archaeological sherds across the southeast United States based on variable selection from compositional fingerprints.

The transfer of advances in chemometrics into archaeometric research opens a wide range of new application possibilities in this rapidly developing field. The present research represents a feasibility study aimed at showing how the huge potential that multivariate analysis and feature selection techniques have demonstrated for classification purposes can be extrapolated to archaeological provenance studies, thus pursuing an enhancement of the resulting classification performance. The classification problem studied here was related to the discrimination of pottery sherds from different sources across the southeast of the United States from their compositional fingerprints. The sample elemental concentrations were analyzed using the stepwise linear discriminant analysis (SLDA) method, thus simultaneously performing feature selection and classification. Several approaches, more or less restrictive according to the geographical scope and the number of considered classes, were explored, following a hierarchical classification approach. In contrast to previous studies on the same data set, the reliable and unequivocal classification strategy presented here did not merely focus on developing a large-scale classification into broad geographical areas, but finer classifications were also successively obtained until samples were assigned into individual regions. The great discrimination ability and effectiveness of the classification methodology proposed are promising and encourage its application to new samples of unknown provenance and the feasibility of using similar approaches in other archaeological studies. The high quality results obtained were even more remarkable considering the relatively small number of discriminant variables selected in each case by the stepwise procedure.

Vinegar classification based on feature extraction and selection from headspace solid-phase microextraction/gas chromatography volatile analyses: a feasibility study.

Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography (GC) and multivariate data analysis were applied to classify different vinegar types (white and red, balsamic, sherry and cider vinegars) on the basis of their volatile composition. The collected chromatographic signals were analysed using the stepwise linear discriminant analysis (SLDA) method, thus simultaneously performing feature selection and classification. Several options, more or less restrictive according to the final number of considered categories, were explored in order to identify the one that afforded highest discrimination ability. The simplicity and effectiveness of the classification methodology proposed in the present study (all the samples were correctly classified and predicted by cross-validation) are promising and encourage the feasibility of using a similar strategy to evaluate the quality and origin of vinegar samples in a reliable, fast, reproducible and cost-efficient way in routine applications. The high quality results obtained were even more remarkable considering the reduced number of discriminant variables finally selected by the stepwise procedure. The use of only 14 peaks enabled differentiation between cider, balsamic, sherry and wine vinegars, whereas only 3 variables were selected to discriminate between red (RW) and white wine (WW) vinegars. The subsequent identification by gas chromatography-mass spectrometry (GC-MS) of the volatile compounds associated with the discriminant peaks selected in the classification process served to interpret their chemical significance.

Mixture resolution according to the percentage of robusta variety in order to detect adulteration in roasted coffee by near infrared spectroscopy.

Near infrared spectroscopy (NIRS), combined with multivariate calibration methods, has been used to quantify the robusta variety content of roasted coffee samples, as a means for controlling and avoiding coffee adulteration, which is a very important issue taking into account the great variability of the final sale price depending on coffee varietal origin. In pursuit of this aim, PLS regression and a wavelet-based pre-processing method that we have recently developed called OWAVEC were applied, in order to simultaneously operate two crucial pre-processing steps in multivariate calibration: signal correction and data compression. Several pre-processing methods (mean centering, first derivative and two orthogonal signal correction methods, OSC and DOSC) were additionally applied in order to find calibration models with as best a predictive ability as possible and to evaluate the performance of the OWAVEC method, comparing the respective quality of the different regression models constructed. The calibration model developed after pre-processing derivative spectra by OWAVEC provided high quality results (0.79% RMSEP), the percentage of robusta variety being predicted with a reliability notably better than that associated with the models constructed from raw spectra and also from data corrected by other orthogonal signal correction methods, and showing a higher model simplicity.

Coffee varietal differentiation based on near infrared spectroscopy.

Near infrared spectroscopy (NIRS) was used to discriminate between arabica and robusta pure coffee varieties and blends of varied varietal composition. Direct orthogonal signal correction (DOSC) pre-processing method was applied on a set of 191 roasted coffee NIR spectra from both pure varieties and blends varying the final robusta content from 0 to 60% (w/w) in order to remove information unrelated to the actual varietal composition of samples. The corrected NIR spectra, as well as raw NIR spectra, were used to develop separate classification models using the potential functions method as class-modelling technique, exploring several options more or less restrictive according to the final number of considered categories. All constructed classification models were compared to evaluate their respective qualities and to show the suitability of applying DOSC method as pre-processing step for developing improved classification models for coffee varietal identification purposes.

Evolución de la mortalidad neonatal y perinatal en la comunidad autónoma de La Rioja (1980-2006) / Trends in neonatal mortality in La Rioja, Spain (1980-2006)

Introducción: Las tasas de mortalidad neonatal y perinatal son un importante indicador de la asistencia sanitaria a la mujer gestante y al recién nacido. El objetivo de este estudio es aportarlos datos de mortalidad neonatal y perinatal de La Rioja en las tres últimas décadas y valorar su evolución. Material y métodos: Se han estudiado las tasas de mortalidad fetal, neonatal inmediata, precoz, tardía y total, así como la mortalidad perinatal precoz y total. Se ha valorado también las tasas y porcentaje de mortalidad perinatal que corresponden a neonatos de muy bajo peso al nacer. Los datos se han recogido del registro de la Unidad Neonatal del Complejo Hospitalario «San Millán-San Pedro» desde 1980 hasta 2006. Resultados: Se ha constatado un descenso en todas las tasas de mortalidad en los últimos 27 años. La mortalidad neonatal media es de 4,72 por 1.000, y ha descendido hasta a 2,6 en 2006. La mortalidad perinatal, cuya media es 9,93 por 1.000, ha disminuido también hasta 2,59 en 2005. El descenso más importante en la mortalidad perinatal total se ha observado en el grupo de neonatos que pesaron menos de 1.500 g. Conclusiones: En las tres últimas décadas, se ha producido un descenso de las cifras de mortalidad neonatal y perinatal en La Rioja. Ha disminuido de forma importante la mortalidad de los neonatos de muy bajo peso (menores de 1.500 g) (AU)

Background: Neonatal and perinatal mortality rates are two of the most important maternal and neonatal health care markers. We have performed a study on the neonatal and perinatal mortality in La Rioja over the last three decades. Patients and methods: We have estimated fetal mortality, immediate, early, late and total neonatal mortality and early and total perinatal mortality rates. The percentage and rates of perinatal mortality in very low birth weight newborns have also been evaluated. Data are obtained from the records of San Millán San Pedro Hospital from 1980 to 2006. Results: A reduction in all mortality rates has been observed over the last 27 years. The mean neonatal mortality is 4.72, and had decreased to 2.6 per 1,000 live births in 2006. Perinatal mortality, with a mean of 9.93, had fallen to 2.59 per 1,000 live births in 2005. The most marked decrease was recorded for the perinatal mortality rate among very low birth weight newborns. Conclusion: Over the last three decades, there has been a marked decrease in all mortality rates, especially in the very low birth weigh newborn perinatal mortality rate (AU)

Meningitis por enterovirus en recién nacidos / Neonatal enteroviral meningitis

La meningitis por enterovirus es una entidad poco frecuente en recién nacidos, que puede infradiagnosticarse ante la normalidad de las pruebas habituales. El estudio de virus en el líquido cefalorraquídeo de neonatos febriles sin foco puede orientar su diagnóstico. Se presentan dos nuevos casos (AU)

Enteroviral meningitis is uncommon in the newborn infant. It may be underdiagnosed because the usual laboratory tests, except that performed in cerebrospinal fluid, may be normal. Two new cases in newborn infants are reported (AU)

Evolución de la natalidad en la comunidad autónoma de La Rioja (1980-2006) / Trends in the birth rate in La Rioja, Spain (1980-2006)

Introducción: En las últimas décadas ha aumentado la natalidad en España. A su vez, han aumentado las cifras de prematuridad, sobre todo en relación con las técnicas de fertilidad y el incremento de partos múltiples. También ha aumentado la supervivencia de estos prematuros. Material y método: Se realiza un estudio de los nacimientos en La Rioja, de la incidencia de partos prematuros y embarazos múltiples, de la patología obstétrica y neonatal, así como del porcentaje de ingresos en la unidad neonatal. Los datos se obtuvieron a partir de los registros del Hospital «San Millán-San Pedro» durante el periodo comprendido entre 1980 y 2006. Resultado: Se confirma en La Rioja un aumento de la tasa de natalidad, hasta alcanzar los 10,12 nacimientos por 1.000 habitantes al año en 2006. Ha aumentado el número de partos múltiples (2,47%), que se asocia a un incremento de cesáreas (23,13%) y prematuridad (7,77%), lo que influye directamente en el número de ingresos en la unidad neonatal. También ha habido un aumento de partos instrumentales (9,51%). De los recién nacidos prematuros, un 11,73% tenía un peso <1.500 g, con un aumento tanto en la incidencia como en la supervivencia en los últimos años. Conclusiones: Se confirma un aumento de la natalidad en La Rioja. Se constata un aumento de partos múltiples, que se asocia al incremento en el número de cesáreas y a la prematuridad. Entre los recién nacidos prematuros aumenta el porcentaje de los que tienen un peso inferior a 1.500 g (AU)

Background: In recent decades, there has been a steady increase in the birth rate in Spain. The rates of preterm delivery are on the rise; this circumstance is closely associated with the improvement in fertilization techniques and the increase in multiple births. Premature infant survival has also improved. Material and methods: We have calculated birth rates, incidence of preterm and multiple births and that of obstetric and neonatal disorders, as well as admission rates. Data were obtained from the records of San Millán San Pedro Hospital from 1980 to 2006. Results: The birth rate in La Rioja increased to 10.12 per 1,000 population/year during 2006. The number of multiple births has increased (2.47%). That incidence is associated with an increase in cesarean sections (23.13%) and preterm births (7.77%). All of these circumstances directly influence the number of admissions to Neonatal Units. A high proportion of forceps or vacuum assisted deliveries (9.51%) has also been recorded. In all, 11.73 % of the preterm newborns weigh less than 1,500 grams, with an increase in the incidence and survival of these infants in recent years. Conclusions: An increase in birth rates in La Rioja is confirmed. There is a high proportion of multiple births, associated with the increase in the number of cesarean section and preterm births. Low birth weight newborns (less than 1,500 grams)are an ever-growing population (AU)

Neumonías adquiridas en la comunidad en pacientes pediátricos en un hospital de La Rioja / Community-acquired pneumonias in pediatric patients in a hospital in La Rioja in northern Spain

Objetivo: Analizar la incidencia, la etiología, las complicaciones, el tratamiento, la estancia media y el coste aproximado de las neumonías adquiridas en la comunidad en el periodo 2004-2006 en La Rioja, así como otros factores que pudieran influir sobre dichas variables. Material y métodos: Estudio retrospectivo. Consulta y recogida manual del diagnóstico al alta y otras variables que se pueden relacionar con el coste hospitalario (edad, número de días de ingreso, etiología, complicaciones, tratamiento) en las historias clínicas de pacientes menores de 14 años ingresados en el Complejo Hospitalario «San Millán-San Pedro» de Logroño, hospital de referencia en la comunidad autónoma de La Rioja. Resultados: Se obtuvo una incidencia de ingreso por neumonía de 4,06 casos/1.000 niños menores de 14 años. La etiología más a menudo diagnosticada fue la neumocócica (8,40%). El coste medio por día de estancia ascendió a 657,14 euros, y la estancia media fue de 6,72 días. Se observó relación entre el coste más elevado y la neumonía por Streptococcus pneumoniaey un mayor número de días de estancia media. Conclusiones: El incremento de las neumonías neumocócicas en los últimos años debería hacernos plantear la posibilidad de realizar más estudios en la población infantil sobre este tema, su posible prevención vacunal (coste-efectividad) y la valoración de administrar tratamiento intravenoso frente a oral de forma ambulatoria como protocolo general para las neumonías. Son muy escasos los estudios de costes realizados sobre esta enfermedad (AU)

Objective: To analyze the incidence, etiology, complications, treatment, average hospital stay and estimated costs associated with cases of community-acquired pneumonia from 2004 to 2006 in La Rioja, as well as to evaluate some of the factors that could have influenced those major variables. Material and methods: Retrospective study. Consultation was performed and the discharge diagnosis and other variables that can be related to the hospital costs (age, number of days of hospitalization, etiology, complications, treatment) were manually recorded in clinical histories of patients under 14 years of age admitted to the «Complejo Hospitalario San Millán-San Pedro», a referral hospital in the Autonomous Community of La Rioja. Results: The incidence of hospitalization for pneumonia was 4.06 cases/1000 patients under 14 years of age. The most frequently diagnosed etiology was pneumococcal pneumonia (corresponding to 8.40% of the patients). The average cost of the hospital stay amounted to 657.14 euros per day, and the average length of the stay was 6.72 days. We found a direct relationship between pneumonia caused by Streptococcus pneumonia e and both a higher hospital cost and a greater number of days of hospitalization. Conclusions: The increase in the incidence of cases of pneumococcal pneumonia over recent years should encourage us to develop a greater number of studies on this subject in the pediatric population, in order to investigate its potential prevention by vaccination (cost-effectiveness) and to evaluate the administration of intravenous treatment as an alternative to oral treatment and as a general protocol for outpatient management of pneumonias. Very few cost studies on this disease have been reported to date (AU)

Factores etiopatogénicos del asma bronquial en la edad infantil / Etiological and pathogenic factors of bronchial asthma in childhood

Introducción: Hay muchos factores implicados en el desarrollo y la progresión del asma bronquial infantil. Objetivo: Valorar si estos factores están claramente implicados en la etiopatogenia de esta enfermedad. Material y métodos: Revisión bibliográfica estructurada de los trabajos sobre factores de riesgo para el asma publicados en bibliografía biomédica actualizada durante los últimos 5 años. Resultados: Se han seleccionado 14 artículos que aporta datos a favor y en contra sobre los factores considerados de riesgo para el desarrollo y la progresión del asma bronquial como la genética o los antecedentes familiares, la atopía, las anomalías de la función pulmonar, el sexo, la lactancia materna y los estilos de alimentación, el tabaco, las infecciones respiratorias virales y otros factores ambientales (hipótesis de la higiene). Conclusiones: Hay discordancia entre la implicación de los diferentes factores etiopatogénicos del asma con la propia enfermedad

Introduction: There are many factors implicated in the development and progression of childhood bronchial asthma. Objective: To determine whether these factors are clear involved in the etiology and pathogenesis of this disease. Material and methods: Structured review of the articles dealing with risk factors for asthma published in the biomedicé literature updated over the last 5 years. Results: The authorss elected fourteen articles that contribute information in favor of and against the factors considered indicate risk for the development and progression of bronchial asthma. These include genetics or family history, atopy, abnormal lung function, sex, breastfeeding and eating habits, smoking, viral respiratory infections and environmental factors (the hygiene hypothesis).Conclusions: There is no consensus as to the involvement (the different etiological and pathogenic factors associate with asthma in the disease itself