Volume XCIII, Number 15, February 22, 1974

11th International Conference of Inborn Errors of Metabolism -- AUG 29-SEP 02, 2009 -- San Diego, CAWOS: 00026894260018

Aplicación de un cultivo iniciador mixto para la producción de aceituna de mesa

The fermentation of olives is usually carried out spontaneously by natural microbiota. Spontaneous fermentation has some disadvantages, such as the formation of defects in the end product due to the activities of undesirable microorganisms. The use of starter cultures could be a promising option to provide a more controlled fermentation environment and to reduce the risk of spoilage. Mixed starter culture use (generally selected Lactobacillus strains with or without yeasts) could reduce pH in a shorter time, producing a higher amount of lactic acid and enhancing microbial safety compared to fermentation with starter cultures containing single species or natural fermentation. Their use could also enhance the organoleptical properties of table olives. Particularly the use of yeast (such as strains of W. anomolus, S. cerevisiae) in the fermentation of olives, in combination or sequentially with lactic acid bacteria could result in an increase in volatile compounds and a more aromatic final product.La fermentación de la aceituna generalmente se lleva a cabo espontáneamente por la microbiota natural. Sin embargo, la fermentación espontánea tiene algunas desventajas, como la formación de defectos en el producto final debido a las actividades de microorganismos indeseables. El uso de cultivos iniciadores podría ofrecerse como una opción importante para proporcionar un entorno de fermentación más controlado y reducir el riesgo de deterioro. El uso de cultivos mixtos iniciadores (cepas generalmente seleccionadas de Lactobacillus con/sin levaduras) podría reducir el pH en un tiempo más corto, produciendo una mayor cantidad de ácido láctico y mejorando la seguridad microbiana, en comparación con la fermentación con cultivos iniciadores que contienen especies individuales o fermentación natural. Su uso también podría mejorar las propiedades organolépticas de las aceitunas de mesa. En particular, el uso de la levadura (como las cepas de W. anomolus, S. cerevisiae) en la fermentación de aceitunas, en combinación o secuencialmente con bacterias de ácido láctico podría dar lugar a un aumento de los compuestos volátiles y a la obtención de un producto final más aromático

Evaluating performance of missing data imputation methods in IRT analyses

Missing data is a common problem in datasets that are obtained by administration of educational and psychological tests. It is widely known that existence of missing observations in data can lead to serious problems such as biased parameter estimates and inflation of standard errors. Most of the missing data imputation methods are focused on datasets containing continuous variables. However, it is very common to work with datasets that are made of dichotomous responses of individuals to a set of test items to which IRT models are fitted. This study compared the performances of missing data imputation methods that are IRT model-based imputation (MBI), Expectation-Maximization (EM), Multiple Imputation (MI), and Regression Imputation (RI). Parameter recoveries were evaluated by repetitive analyses that were conducted on samples that were drawn from an empirical large-scale dataset. Results showed that MBI outperformed other imputation methods in recovering item difficulty and mean of the ability parameters, especially with higher sample sizes. However, MI produced the best results in recovery of item discrimination parameters

Korištenje GIS tehnika za modeliranje širenja antropogene buke koju stvara motorna pila prilikom sječe šuma

Noise is an environmental pollution that negatively affects human health and reduces the performance of employees. Forest harvesting activities are one of the working environments where noise effect is intense. The most common equipment used in forest operations is chainsaw whose noise affects not only the operator but also the wildlife in the territory. The noise maps showing noise propagation can be effectively used in evaluating and controlling the noise effects. In this study, it was aimed to measure the anthropogenic noise levels ​​resulting from the chainsaw used in tree felling and to map its noise propagation with SPreAD-GIS (System for Prediction of Acoustic Detectability) which is a GIS (Geographical Information Systems) based noise prediction software. The study was conducted in Karacabey Flooded Forest within the city of Bursa in Türkiye. The results indicated that the average noise level from the chainsaw was above the danger limit (90 dBA) that causes increased physiological reactions and headache on the workers. According to the noise propagation map, the noise exposure of the employees exceeded the warning limit (85 dBA) and the maximum noise level was 95.96 dBA during the harvesting activity. In some parts of the study area, the noise level was 45 dBA or above, causing negative effects on bird species. It can be concluded that the noise maps can be effectively used to determine noise propagation generated by a chainsaw and evaluate the noise effects on the operators and as well as on the bird species in the perimeter.Buka je onečišćenje okoliša koje negativno utječe na zdravlje ljudi i smanjuje učinak zaposlenika. Aktivnosti sječe šuma jedno su od radnih okruženja u kojima je buka intenzivna. Najčešća oprema koja se koristi u šumarstvu je motorna pila, čija buka utječe ne samo na operatera, već i na divlje životinje na teritoriju. Karte buke koje prikazuju širenje buke mogu se učinkovito koristiti za procjenu i kontrolu učinaka buke. U ovome radu cilj je bio izmjeriti razine antropogene buke nastale radom motorne pile koja se koristi pri sječi stabala i mapirati širenje buke pomoću SPreAD-GIS programa (Sustav za predviđanje akustične detektabilnosti) čija se procjena širenja buke temelji na GIS-u (Geografski informacijski sustav). Istraživanje je provedeno u poplavnoj šumi Karacabey na području grada Bursa u Turskoj. Rezultati su pokazali da je prosječna razina buke motorne pile iznad granice opasnosti (90 dBA), što uzrokuje pojačane fiziološke reakcije i glavobolju radnika. Prema karti širenja buke, izloženost zaposlenika buci prešla je granicu upozorenja (85 dBA), a maksimalna razina buke tijekom rada iznosila je 95,96 dBA. U nekim dijelovima istraživanog područja razina buke iznosila je 45 dBA ili više, što je uzrokovalo negativan utjecaj na vrste ptica. Može se zaključiti da se karte buke mogu učinkovito koristiti za određivanje širenja buke koju stvara motorna pila i procjenu učinaka buke na operatere, kao i na vrste ptica u okruženju

Management of spontaneous pneumothorax in patients with COVID-19.

ObjectivesThe coronavirus disease 2019 (COVID-19) pneumonia may cause cystic features of lung parenchyma which can resolve or progress to larger blebs. Pneumothorax was more likely in patients with neutrophilia, severe lung injury and a prolonged clinical course. The timely diagnosis and management will reduce COVID-19-associated morbidity and mortality.MethodsWe present 11 cases of spontaneous pneumothorax managed with chest tube thoracostomy or high-dose oxygen therapy. Isolated spontaneous pneumothorax was detected in all cases.ResultsEight cases were male and 3 cases were female. There were bilateral ground-glass opacities or pulmonary infiltrates in the parenchyma of the 10 cases. We detected neutrophilia, lymphopaenia and increased C-reactive protein, Ferritin, lactate dehydrogenase, D-Dimer, interleukin-6 levels in almost all cases. Chest tube thoracostomy was sufficient to treat pneumothorax in our 9 of case. In 2 cases, pneumothorax healed with high-dose oxygen therapy. Favipiravir and antibiotic treatment were given to different 10 patients. In our institution, all patients with COVID-19 infection were placed on prophylactic or therapeutic anticoagulation, unless contraindicated. The treatments of patients diagnosed with secondary spontaneous pneumothorax during the pandemic period and those diagnosed with secondary spontaneous pneumothorax in the previous 3 years were compared with the durations of tube thoracostomy performed in both groups.ConclusionsThe increased number of cases of pneumothorax suggests that pneumothorax may be a complication of COVID-19 infection. During medical treatment of COVID-19, pneumothorax may be the only reason for hospitalization. Although tube thoracostomy is a sufficient treatment option in most cases, clinicians should be aware of the difficulties that may arise in diagnosis and treatment

Heterologous expression, purification and structural features of native Dictyostelium discoideum dye-decolorizing peroxidase bound to a natively incorporated heme

The Dictyostelium discoideum dye-decolorizing peroxidase (DdDyP) is a newly discovered peroxidase, which belongs to a unique class of heme peroxidase family that lacks homology to the known members of plant peroxidase superfamily. DdDyP catalyzes the H2O2-dependent oxidation of a wide-spectrum of substrates ranging from polycyclic dyes to lignin biomass, holding promise for potential industrial and biotechnological applications. To study the molecular mechanism of DdDyP, highly pure and functional protein with a natively incorporated heme is required, however, obtaining a functional DyP-type peroxidase with a natively bound heme is challenging and often requires addition of expensive biosynthesis precursors. Alternatively, a heme in vitro reconstitution approach followed by a chromatographic purification step to remove the excess heme is often used. Here, we show that expressing the DdDyP peroxidase in ×2 YT enriched medium at low temperature (20°C), without adding heme supplement or biosynthetic precursors, allows for a correct native incorporation of heme into the apo-protein, giving rise to a stable protein with a strong Soret peak at 402 nm. Further, we crystallized and determined the native structure of DdDyP at a resolution of 1.95 Å, which verifies the correct heme binding and its geometry. The structural analysis also reveals a binding of two water molecules at the distal site of heme plane bridging the catalytic residues (Arg239 and Asp149) of the GXXDG motif to the heme-Fe(III) via hydrogen bonds. Our results provide new insights into the geometry of native DdDyP active site and its implication on DyP catalysis

Wheat and hazelnut inspection with impact acoustics time-frequency patterns

Kernel damage caused by insects and fungi is one of the most common reason for poor flour quality. Cracked hazelnut shells are prone to infection by cancer producing mold. We propose a new adaptive time-frequency classification procedure for detecting cracked hazelnut shells and damaged wheat kernels using impact acoustic emissions recorded by dropping wheat kernels or hazelnut shells on a steel plate. The proposed algorithm is based on a flexible local discriminant bases (F-LDB) procedure. The F-LDB method combines local cosine packet analysis and a frequency axis clustering approach which supports individual time and frequency band adaptation. Discriminant features are extracted from the adaptively segmented acoustic signal, sorted according to a Fisher class separability criterion, post processed by principal component analysis and fed to linear discriminant. We describe experimental results that establish the superior performance of the proposed approach when compared with prior techniques reported in the literature or used in the field. Our approach achieved classification accuracy in paired separation of undamaged wheat kernels from IDK, Pupae and Scab damaged kernels with 96%, 82% and 94%. For hazelnuts the accuracy was 97.1%

Identification of damaged wheat kernels and cracked-shell hazelnuts with impact acoustics time-frequency patterns

A new adaptive time-frequency (t-f) analysis and classification procedure is applied to impact acoustic signals for detecting hazelnuts with cracked shells and three types of damaged wheat kernels. Kernels were dropped onto a steel plate, and the resulting impact acoustic signals were recorded with a PC-based data acquisition system. These signals were segmented with a flexible local discriminant bases (F-LDB) procedure in the time-frequency plane to extract discriminative patterns between damaged and undamaged food kernels. The F-LDB procedure requires no prior knowledge of the relevant time or frequency indices of the impact acoustics signals for classification. The method automatically finds all crucial time-frequency indices from the training data by combining local cosine packet analysis and a frequency axis clustering approach, which supports individual time and frequency band adaptation. Discriminant features are extracted from the adaptively segmented acoustic signal, sorted according to a Fisher class separability criterion, post-processed by principal component analysis, and fed to a linear discriminant classifier. Experimental results establish the superior performance of the proposed approach when compared to prior techniques reported in the literature or used in the field. The new approach separated damaged wheat kernels (IDK, pupal, and scab) from undamaged wheat kernels with 96%, 82%, and 94% accuracy, respectively. It also separated cracked-shell hazelnuts from those with undamaged shells with 97.1% accuracy. The adaptation capability of the algorithm to the time-frequency patterns of signals makes it a universal method for food kernel inspection that can resist the impact acoustic variability between different kernel and damage types. 2008 American Society of Agricultural and Biological Engineers