bluuebunny/crossref_metadata_2025 huggingface dataset:
A rapid method for determination of polar compounds in used frying fats and oils
Authors: Marmesat S. , Velasco J. , Márquez-Ruiz G. , Dobarganes M.C.
Published: October 2008

The determination of polar compounds by adsorption chromatography is the most accepted method for the analysis of used frying fats due to its high precision and accuracy. However, this method is expensive and time consuming. In this study, a rapid analytical method to determine polar compounds is proposed. Starting from milligrams of sample dissolved in a solution of hexane containing methyl oleate as internal standard, the nonpolar fraction, which comprises the non-altered triglycerides (TG) and the internal standard, is obtained by solid phase extraction. Then, the non polar fraction is quantitatively analyzed in 15 min by high-performance size-exclusion chromatography (HPSEC) and the polar fraction is determined by difference of weight. Response factors for pure TG and FAME were calculated. Six samples of sunflower oils of different degrees of unsaturation were analyzed in triplicate and the results were compared with those obtained by the gravimetric method based on silica classical column chromatography. Results showed no significant differences between the two methods. In addition, the repeatability of the proposed method was excellent, as the coefficient of variation ranged from 1.5 to 13% depending on the contents of polar compounds.
Uncontrolled variables in frying studies: differences in repeatability between thermoxidation and frying experiments
Authors: Rodrigues Machado Eliana , Marmesat Susana , Abrantes Shirley , Dobarganes Carmen
Published: October 2008

Palm oil, soybean oil and partially hydrogenated soybean oil were used to define the repeatability of oil degradation under thermoxidation in the absence of food and during the frying of potatoes. Total polar compounds and their constituent polymeric triglycerides, oxidized monomeric triglycerides and diglycerides were analyzed. The oils were thermoxidized under standard conditions in a Rancimat apparatus at 180 °C for 25 hours. Discontinuous frying experiments were carried out in triplicate in three apparently identical domestic fryers. Five batches of potatoes were fried per day in each fryer. Oils were heated at 180 °C in periods of 5 h per day during 5 consecutive days so that the total heating period was 25 h. Repeatability was high in the thermoxidation assays and rather low in the frying experiments. Significant differences between the oils were found in the thermoxidation experiments, while no significant differences were found in the frying assays due to large standard deviations. The participation of variables related to the fryer performance which are difficult to control, was deduced. Among them, differences in the heating/cooling cycles at high temperature might be important. The contribution of fryer performance to the decreased repeatability was confirmed in further frying experiments with palm oil. Results showed that repeatability for the same fryer was higher than that obtained when different fryers were considered.
Influence of desalinator wastewater for the cultivation of Arthrospira platensis. Fatty acids profile
Authors: Volkmann Harriet , Imianovsky Ulisses , Badiale Furlong Eliana , Barcelos Oliveira Jorge Luiz , Sebastião Sant’Anna Ernani
Published: October 2008

The need for a desalination processes in northeastern Brazil is due to the salinity of its water sources. However, these processes produce residues with high saline concentrations and a significant environmental impact. These wastewaters can be used for Arthrospira platensis cultivation. This work aimed to cultivate Arthrospira platensis in three different media: Paoletti Synthetic Medium (PSM), Salinated Water Medium (SWM) and Desalinator Wastewater Médium (DWWM). Microalgae were cultivated under controlled conditions, in 4 L photobioreactors, 30±1°C, 12 hours of light/dark photoperiod provided by fluorescent lamps at a light intensity of 140 μmol• m–2•s–1 and constant bubbling of air (0.5 L•L–1 •min–1). The effect of different media on cell concentration, productivity, total content of lipids and fatty acids profile was verified. Higher cell concentration, as well as higher productivity was observed in DWWM: 4.954 (±0.554) g•L–1 and 0.225 (±0.042) g•L–1 •day–1, respectively. Concerning total lipids, the contents of 4.54% and 4.69% were observed in DWWM and SWM, respectively. High levels of saturated fatty acids were observed in both treatments. Concerning γ-linolenic acid, the contents of 13.09% (DWWM) and 11.95% (SWM) were found.
Analysis of used frying fats for biodiesel production
Authors: Ruiz-Méndez M. V. , Marmesat S. , Liotta A. , Dobarganes M. C.
Published: October 2008

Used frying fats and oils with highly variable and uncontrolled quality are used for the production of biodiesel . The objective of this study was to define the analytical methods useful to obtaining information on the quality of the used frying oils as raw material for biodiesels as well as for the characterization of the biodiesels obtained from them. Twentyfour used frying oils from restaurants and domestic fryers were analyzed before and after transesterification to fatty acid methyl esters (FAME). From a detailed analysis of the samples by means of a combination of adsorption and size exclusion chromatography, the quantitative importance of polymeric compounds was deduced both from the direct analysis of the oils and from their FAME. Excellent linear correlation between polar compounds and polar FAME (R=0.9768) was found. The possibilities of interferences from polar fatty acid in the standard method to determine the ester content are defined. Finally, determination of non-polar FAME by silica column is proposed as a good alternative to the gas chromatography method.
Pistachio (Pistacia vera) seed oil composition: geographic situation and variety effects
Authors: Chahed T. , Bellila A. , Dhifi W. , Hamrouni I. , M’hamdi B. , Kchouk M. E. , Marzouk B.
Published: October 2008

This study was aimed at characterizing four Tunisian pistachio cultivations (Pistacia vera) from the Mateur (North), Nabeul (North-East), Kairouan (Middle) and Sfax (Middle- East) regions and two varieties, Mateur and Ohadi, considering fatty acid composition and main lipid class contents (polar lipids, diacylglycerols, triacylglycerols and free fatty acids) in ripe seeds. Lipid classes were separated using thin layer chromatography, and fatty acid methyl esters (FAMEs) were analyzed by gas chromatography. Oleic acid (C18:1 Δ9) was the major fatty acid for all samples; those of the Mateur region (the northern region) differed significantly with the lowest content in C18:1 (54.2 % of total fatty acids) and the highest in C18:2 (24.1 %). The total amount of fatty acids (TFA) in the seeds of Ohadi variety was significantly lower than that of the Mateur variety from the Sfax region. Triacylglycerols were most abundant in pistachio seeds from Nabeul (98.5% of total glycerolipids).
Production of biodiesel from vegetable oils
Authors: Cerveró José María , Coca José , Luque Susana
Published: October 2008

Biodiesel is produced by transesterification of triglycerides present in animal fat or vegetable oils, by displacing glycerine with a low molar mass alcohol. This resulting ester mixture has physico-chemical properties similar to those of petroleum diesel. This paper reviews the synthetic paths that lead to biodiesel by means of the catalytic transesterification of vegetable oils. Although methyl esters are at present the only ones produced at industrial scale, the use of ethanol, which can also be obtained from renewable resources, has been considered, since it would generate a cleaner and more biocompatible fuel.
Detection of contaminations and/or adulterations of the extra virgin olive oil with seeds oils (sunflower and soybean) and olive pomace oil
Authors: Contiñas A. , Martínez S. , Carballo J. , Franco I.
Published: October 2008

The objective of this work was to determine the contents of fatty acids, squalen and triglycerides and the values of some spectrophotometric parameters in a representative number of samples of refined seed oil (sunflower and soybean), refined olive pomace oil and extra virgin olive oil and to attempt the detection of possible contaminations and/or adulterations of the virgin olive oil with seed oils or residue olive oil from the differentiating parameters of each oil type was carried out. The K270 value and the sum of the percentages of the trans-linoleic and trans-linolenic isomers allow for detection of the presence of 10% refined residue olive oil in extra virgin olive oil. The detection of 1% and 2% sunflower and soybean oils respectively, in extra virgin olive oil was possible through theΔECN42 values and the percentages of the sum of the isomeric trans-linoleic and trans-linolenic. The three adulterations made (1%, 2% and 10% refined sunflower oil, refined soybean oil and refined olive pomace oil, respectively, in extra virgin olive oil) were correctly differentiated by applying discriminant analysis techniques using ΔECN42, ΔK and the sum of the translinoleic and trans-linolenic isomers as variables.
Fractionation and interesterification of palm (Elaeis guineensis) oil from Peruvian Amazon
Authors: García de Sotero Dora , Sandoval del Águila Jorge , Saldaña Ramírez Robinson , Cárdenas de Reátegui Gladys , Soplín Ríos José Antonio , Sotero Solís Víctor , Pavan Torres Rosángela , Mancini Filho Jorge
Published: October 2008

In the present work, the physical and chemical characteristics of the fruit of the oily palm coming from the river basin of the Manití (Region Loreto - Peru) were studied. Also, the fractionation of the palm oil and the interesterification of mixtures of palm oil/estearin was carried out. Physico- chemical properties of the crude oil and of the products obtained and fatty acids were analysed by gas chromatography. The level of saturated fatty acids increased from 51,17% in the palm oil to 54,31% in the stearin. The best products for the food industry were the interesterified samples as they had melting points close to 37 °C.
Conjugated linoleic acid (CLA). Cis 9, trans 11 and trans 10, cis 12 isomer detection in crude and refined corn oils by capillary GC
Authors: Tokuşoğlu Özlem
Published: October 2008

Conjugated linoleic acids (CLAs) exhibit protective effects against various types of cancer and heart diseases. With the newly developed capillary gas chromatographic method (GC), cis9, trans11 and trans10, cis12 octadecadienoic acid isomers of CLA (C18:2) were determined in crude and refined corn oils as qualitative and quantitative measurements. Cis 9, trans11 C18:2 (c9, t11 CLA) was the major CLA isomer in both oils. It was found that c9, t11 CLA was 0.62% of the total lipid in crude oil and 1.24% of the total lipid in refined oil. Using the refining process, the total CLA was 1.38% whereas that of crude corn oil was 0.62%. An approximate 2.2 fold increase in the total CLA was found in refined oil (n = 9) (p < 0.01). The alteration in CLA could be used as a quality indicator for the refining process due to the contrubution of CLA to polyunsaturated fatty acids. Analytical method validation, calibration (R2 = 0.9999) and recovery data [y = 2.782x + 0.046 (R2 = 0.9999)] were performed (p < 0.01).The proponed chromatographic procedure could be used for vegetable oil quality control
Antioxidant potential of extracts from different agro wastes: Stabilization of corn oil
Authors: Sultana Bushra , Anwar Farooq , Rafique Asi Muhammad , Ali Shahid Chatha Shahzad
Published: October 2008

The antioxidant potential of 80% methanolic extracts of some agro wastes (pomegranate peel, apple peel, banana peel, citrus peel, corncob, wheat husk, wheat bran, rice bran, and rice hull) was assessed. The yields of the extracts varied over a wide range (8.83 to 29.9 g/100g of dry weight). TPC, TFC, total flavonols (kaempeferol, quercetin, myricetin; HPLC method), DPPH. radical scavenging and inhibition of linoleic acid peroxidation for the extracts varied significantly (P < 0.05) ranging from 0.16-36.40, 0.026-4.89 g/100g of dry matter, 1.06-2622.41 mg/Kg of dry matter, 11.2-52.6, and 64.8-96.4%, respectively. Pomegranate peel extract, offering the highest TPC, TFC, and total flavonols exhibited superior antioxidant activity followed by apple peel, citrus peel, banana peel, corncob, wheat bran, rice bran, wheat husk, and rice hull. Furthermore, the antioxidant effectiveness of the extracts was assessed using corn oil (CO) as the oxidation substrate. CO samples stabilized with extracts at a concentration of 600 ppm (w/w) were subjected to accelerated aging (60 ºC, oven heating, 30 days; 8 h heating cycle per day), and analyzed periodically for the extent of oxidative alterations following the measurement of conjugated dienes (CD), conjugated trienes (CT), p-anisidine and peroxide values. The correlation between the results of different antioxidant assays and oxidation parameters investigated in the present study indicated that fruit peel extracts, exhibiting higher TPC, TFC, flavonol and scavenging power, were also more potent for enhancing the oxidative stability of corn oil.
Probiotic characteristics of Lactobacillus plantarum strains from traditional butter made from camel milk in arid regions (Sahara) of Algeria
Authors: Maurad Kacem , Meriem Kaid Harche
Published: October 2008

Lactobacillus plantarum strains previously isolated from the traditional butter made from camel milk (shmen) were evaluated for some probiotic criteria. Among 38 strains investigated for bile resistance, 14 were tolerant to 2% oxgall with survival percentages ranging from 69 to 75%. Out of these, only 4 strains (L. plantarum SH5, SH12, SH24 and SH32) were sufficiently resistant to pH 2.0 for 2 to 6 h incubation periods. Only crude extracts of L. plantarum SH12 and L. plantarum SH24 were inhibitory against Lactococcus lactis B8, the strain used as indicator. The antibacterial activity of crude extracts was completely lost after treatment with α-chymotrypsin and proteinase K. L. plantarum SH12 and SH24 strains were susceptible to penicillin G, oxacillin, vancomycin and clindamycin, but resistant to tetracycline and kanamycin. These strains showed rapid acidification activity (0.921 and 1.075 mmol/l of lactic acid, respectively), a good proteolytic activity (5.45 and 3.49 mg/l tyrosine at 72 h, respectively) and high survival percentage after freeze-drying. None of the strains produced polysaccharides or haemolysin in sheep blood.
Lactobacillus pentosus DSM 16366 starter added to brine as freeze-dried and as culture in the nutritive media for Spanish style green olive production
Authors: Peres Cidália , Catulo Luis , Brito Dulce , Pintado Cristina
Published: October 2008

Lactobacillus pentosus DSM 16366, a strain originally isolated from olive fermentation, was used as a starter culture for “Azeiteira” the preparation of Spanish style green olives. Inoculum was added to the fermentors as a freezedried starter culture or as a culture in the nutritive media. Lactic acid fermentation induction produced a more rapid acidification of brines and reduced the survival period of Enterobacteriaceae compared with the uninoculated process. The best results were obtained using the nutritive media as a culture carrier rather than the freeze-dried starter.
Structural characterization by Nuclear Magnetic Resonance of ozonized triolein
Authors: F. Díaz Maritza , Gavín José A. , B. de Andrade Jailson
Published: October 2008

In the present study ozonized triolein with 739 mmolequiv/ kg peroxide index is characterized by NMR.The triolein and ozonized triolein show very similar 1H NMR spectra except for the resonances at δ 9.74 ppm, which correspond to aldehydic protons and δ 5.14 ppm (ozonides methylic protons). Other new signal assignments are based on the connectivities provided by the proton scalar coupling constants δ 2.41 ppm (methylenic group allylic to aldehydic protons and ozonides methynic protons) and δ 1.67 ppm (methylenic protons in position with respect to ozonides methylic protons). From the 13C and 1H-13C spectrum of the ozonized triolein, the presence of ozonides was confirmed by the signals δ 104.2 and 104.3 ppm, respectively. Other new signals in δ 43.9 ppm confirm the presence of methylenic carbon ozonides. From the structural elucidation of ozonated triglycerides, relevant chemical information about ozonated vegetable oil can be found .
Study of the possible chemical and biochemical events that affect the increase of the acidity in process extraction of maize oil
Authors: Romero Danabely , Bolívar Francisco , Salinas Nancy
Published: October 2008

The present work has the objective of studying the chemical and biochemical factors that promote the increase in acidity in oil produced from maize grains during storage in silos, the degermination and palletizing. A water activity ((aw) of 0,805 ± 0,003 was determined in maize grains, a peroxide index (IP) of 6,75 ± 0,20 in degermination, and a % acidity of 4,07 ± 0,06 in palletized oil. The lipase activity was performed by potentiometry in the presence of bovine bile and olive oil. The enzymes were extracted in a 1% (p/v) saline medium at 13000 rpm (15 min), resulting in an activity at pH 7,6, 36 °C of 2.6 meq/g min in samples without physical processing treatments, and 0,02-0,04 meq/g min in samples submitted to processing . A bifactorial design and central stars surface type composition studied the hydrolytic deterioration of the oil. The water flow was significant. The mathematical equation obtained was: % acidity = 4.88 - 0.741557A, with a regression coefficient of (R2) 91.76%.
An analysis of the industries of olive oil refining in Andalusia
Authors: García Brenes M. David
Published: October 2008

This work studies the economic relationships between the industries of refining and other links of the foodprocessing chain of the olive oil. In addition, the principal components of the cost structure of the refining and packaging processes are analyzed. Also, an analysis of the evolution followed by the participation of the foreign investment in the share capital of the refining industries is included. Finally, the strategies that the industries of refining are developing on the market in origin are commented.
Generalization of heterogeneous alpine vegetation in air photo-based image classification, Latnjajaure catchment, northern Sweden
Authors: Lindblad K. E. M. , Nyberg R. , Molau U.
Published: October 2008

Hemos llevado a cabo la cartografía de la vegetación alpina a escala media (nivel de cuenca experimental) mediante interpretación remota. Esta metodología plantea dificultades debido a la distribución en mosaico de la vegetación y a la heterogeneidad del espetro obtenido. Se discuten las posibilidades de generalización de los resultados y el grado de precisión alcanzado en este caso experimental mediante fotografía aérea digital CIR aplicada a una clasificación automática de las comunidades vegetales dominantes. La información espectral obtenida por foto áerea se complementó con la clasificación de las comunidades vegetales in situ y la información topográfica derivada de un Modelo Digital de Terreno. Además se marcaron 150 puntos de control en el campo por medio de GPS. Los resultados de tres clasificaciones alternativas se analizaron mediante el estadístico Kappa y la precisión del usuario y del productor. El grado de precisión obtenido apenas difirió entre clasificaciones, a pesar de que sí había diferencias significativas entre la precisión del usuario o del productor para las diferentes clases, así como para la superficie total y la distribución. La presencia sobre el terreno de una clase correctamente identificada a menos de 5 m de un punto de control, aumentó la precisión en un 16 %. Unas 10 comunidades vegetales pueden ser identificadas con un grado de precisión aceptable al terminar la clasificación. Si un mosaico de píxels de alta resolución se generaliza a unidades cuya precisión es comparable a la de un simple GPS, tal generalización puede también influir en la cantidad de información de la imagen.
Métodos para el censo y seguimiento de plantas rupícolas amenazadas
Authors: Goñi D. , García M. B. , Guzmán D.
Published: October 2008

La conservación de especies de flora amenazada requiere tanto del clásico conocimiento de su área de distribución y ocupación como de parámetros demográficos tales como el tamaño, estructura y dinámica de las poblaciones. La inaccesibilidad de muchas poblaciones de plantas rupícolas hace que esta información no pueda ser recogida mediante los métodos utilizados para plantas que viven en otros ambientes más comunes. Puesto que a menudo la flora endémica y amenazada de montaña está ligada a los hábitats rocosos, hemos desarrollado algunos métodos específicos para poder realizar prospecciones y censos con cierta fiabilidad en este hábitat. Dichos métodos, utilizados en el Pirineo aragonés e ilustrados con ejemplos concretos, corresponden a tres niveles de intensidad de seguimiento, y tienen como objetivo obtener información que permita tanto una catalogación objetiva de especies amenazadas como la toma de decisiones en posibles actuaciones para asegurar su persistencia. Este conjunto de métodos permite cierta flexibilidad a la hora de elegir el más adecuado en cada situación particular, al tiempo que se recoge información comparable para un conjunto de especies que comparten hábitat.
Fenomorfología y estrategias funcionales de los principales tipos de caméfitos leñosos mediterráneos del Prepirineo
Authors: Palacio S.
Published: October 2008

Los caméfitos leñosos dominan extensas áreas de clima mediterráneo donde los altos niveles de estrés o las frecuentes perturbaciones impiden el desarrollo de árboles y arbustos. No obstante, pese a su gran relevancia en los ecosistemas mediterráneos, la atención dedicada a su estudio ha sido muy limitada, sobre todo si se compara con los estudios realizados sobre árboles y arbustos de las mismas zonas. Se desconocen, por ejemplo, los límites de su diversidad ecológica. De hecho, este tipo de plantas presenta una gran variedad de formas de crecimiento que parece ser indicativa de sus diferentes estrategias ecológicas y, por tanto, de su elevada diversidad funcional. En esta nota se analizan las características fenológicas y morfológicas de los principales tipos de caméfitos leñosos mediterráneos existentes en las montañas prepirenaicas. El objetivo principal es estudiar los mecanismos que permiten a estas plantas sobrevivir a las perturbaciones y condiciones de estrés propias de los ambientes en los que crecen, llegando a perfilar sus principales estrategias ecológicas o funcionales.
Endoluminal arterial stents below the inguinal ligament
Authors: Reekers J A
Published: November 2008

Twisted literature
Outcome from abdominal aortic aneurysms in Scotland, 1991–2006
Authors: Mofidi R , Suttie S A , Howd A , Dawson A R W , Griffiths G D , Stonebridge P A
Published: November 2008

Background

This study assessed the impact of sex, presentation and treatment on outcome from abdominal aortic aneurysm (AAA) in Scotland.

Methods

All patients admitted from January 1991 to December 2006 with a primary diagnosis of AAA were identified. Patients were stratified by age, sex, admission diagnosis (ruptured versus intact) and procedure performed (endovascular versus open repair). Multivariable logistic regression analysis was used to determine predictors of mortality.

Results

Some 9779 men and 2927 women were admitted with a principal diagnosis of AAA. Women were significantly older than men (median (range) age 75 (35–97) versus 71 (17–96) years; P < 0·001). A higher proportion of women presented with a ruptured AAA (29·5 versus 27·5 per cent; P = 0·043). Age (odds ratio (OR) 2·52 (95 per cent confidence interval 2·36 to 2·74); P < 0·001), female sex (OR 1·63 (1·48 to 1·78); P < 0·001) and admission diagnosis (OR 10·49 (9·53 to 11·54); P < 0·001) were independent predictors of early death, whereas endovascular repair predicted survival (OR 0·67 (0·58 to 0·76); P < 0·001).

Conclusion

Women presenting with an AAA were older and more likely to be admitted with a ruptured aneurysm. Female sex was an independent risk factor for death from AAA.
ChemInform Abstract: Synthesis and Biological Activities of New Hydroxy‐3‐pyrazolyl‐4H‐chromen‐4‐ones and Their O‐Glucosides.
Authors: Hatzade K. M. , Taile V. S. , Gaidhane P. K. , Haldar A. G. M. , Ingle V. N.
Published: November 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Monitoring of Airborne Mumps and Measles Viruses in a Hospital
Authors: Agranovski Igor E. , Safatov Alex S. , Agafonov Alex P. , Pyankov Oleg V. , Sergeev Alex N.
Published: November 2008

A new personal bioaerosol sampler, which was found suitable for continuous long‐term (up to 8 h) monitoring of airborne bacteria, fungi, and viruses, was recently developed. A range of investigations under controlled laboratory conditions verified the performance of the device for both stress sensitive and robust viral particles. To decrease the detection time, the next step of the technique development was related to utilization of the sampler in combination with polymerase chain reaction (PCR) technology in the laboratory. The combined device was found to be fully feasible with the corresponding decrease of the detection time from a few days to 2.5 h. In addition, the results for targeted microorganisms were not affected by background biological particles and cross‐reaction was not observed. The current study is the first trial to use the new combined device, i. e., sampler‐conventional PCR device, for monitoring airborne viruses in the field. The monitoring procedures were performed in hospital infection wards with patients suffering from mumps and measles diseases to detect the corresponding disease causing viruses in the ambient air. The results for the existence of the airborne viruses were obtained for both strains. A simple procedure is also suggested for enumeration of microbial contamination in the ambient air.
Aspergillums Niger assisted crystal growth of calcium tartrate: an alternative method to grow crystals
Authors: Parekh B. B. , Joshi V. S. , Pawar V. , Thaker V. S. , Joshi M. J.
Published: November 2008

A novel method of growing calcium tartrate single crystals was developed in which the crystals were hanging freely in solution assisted by fine filaments of fungi (Aspergillums niger). Spores of A. niger were inoculated and allowed to grow in the supernatant solution of calcium chloride and tartaric acid (1:1) on the silica hydro‐gel impregnated with orthophosphoric acid. Transparent, prismatic, calcium tartrate crystals were grown hanging in the filamentous network of the fungi after 10 days in the supernatant solution. This network of the mycelium facilitated and mimicked the gel. The grown crystals were identified as calcium tartrate trihydrate and characterized by powder XRD, FTIR and TGA. This technique provides an alternate and a novel technique to grow crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Essential differences in ligand presentation and T cell epitope recognition among HLA molecules of the HLA‐B44 supertype
Authors: Hillen Nina , Mester Gabor , Lemmel Claudia , Weinzierl Andreas O. , Müller Margret , Wernet Dorothee , Hennenlotter Jörg , Stenzl Arnulf , Rammensee Hans‐Georg , Stevanović Stefan
Published: November 2008

Human leukocyte antigens (HLA) have long been grouped into supertypes to facilitate peptide‐based immunotherapy. Analysis of several hundreds of peptides presented by all nine antigens of the HLA‐B44 supertype (HLA‐B*18, B*37, B*40, B*41, B*44, B*45, B*47, B*49 and B*50) revealed unique peptide motifs for each of them. Taking all supertype members into consideration only 25 out of 670 natural ligands were found on more than one HLA molecule. Further direct comparisons by two mass spectrometric methods – isotope labeling as well as a label‐free approach – consistently demonstrated only minute overlaps of below 3% between the ligandomes of different HLA antigens. In addition, T cell reactions of healthy donors against immunodominant HLA‐B*44 and HLA‐B*40 epitopes from EBV lacked promiscuous T‐cell recognition within the HLA‐B44 supertype. Taken together, these results challenge the common paradigm of broadly presented epitopes within this supertype.
PVA‐based tunable buffering membranes for isoelectric trapping separations
Authors: Fleisher‐Craver Helen C. , Vigh Gyula
Published: November 2008

PVA‐based buffering membranes with tunable pH values were prepared on a PVA substrate by reacting PVA, glycerol‐1,3‐diglycidyl ether, –NH2 group‐containing buffers and –NH2 group‐containing titrants in the presence of sodium hydroxide. The pH of the buffering membranes could be tuned in the 3<pH<10 range according to the Hendersson–Hasselbach equation while maintaining buffering capacities in excess of 100 mM. Detailed recipes for the preparation of six families of buffering membranes are tabulated and provided as Supporting Information. The buffering membranes were used to trap and desalt ampholyte solutions and separate proteins having a ΔpI as small as 0.1. The membranes were mechanically and hydrolytically stable and could be stored, even in 10<pH sodium hydroxide solutions, in excess of 6 months.
Stereochemical dependence of NMR geminal spin–spin coupling constants
Authors: Contreras Rubén H. , Provasi Patricio F. , dos Santos Francisco P. , Tormena Cláudio F.
Published: November 2008

In this work it was sought to explore the versatility of geminal spin–spin coupling constants, 2JXY SSCCs, as probes for stereochemical studies. A set of compounds, where their experimental 2JXY SSCCs through the X–C–Y molecular fragment are predicted to be sensitive to hyperconjugative interactions involving either bonding or antibonding orbitals containing the C carbon atom (‘coupling pathway’), were analyzed. SSCC calculations were performed for some selected examples using the second order polarization propagator approximation (SOPPA) method or within the DFT‐B3LYP framework. Hyperconjugative interactions were calculated within the Natural Bond Orbital (NBO) approach. Results are condensed in two qualitative rules: Rule IM—hyperconjugative interactions transferring charge into the coupling pathway yield a positive increase to the Fermi contact (FC), contribution to 2KXY reduced spin–spin coupling constants (RSSCC), and Rule IIM—hyperconjugative interactions transferring charge from the coupling pathway yield a negative increase to the FC contribution to 2KXY RSSCC. Copyright © 2008 John Wiley & Sons, Ltd.
Study on the layer structure of W/C multilayers deposited by magnetron sputtering using x‐ray reflectivity
Authors: Deng Songwen , Qi Hongji , Shao Jianda
Published: November 2008

A study on the layer structure of W/C multilayers deposited by magnetron sputtering is reported. In the study, soft x‐ray resonant reflectivity and hard x‐ray grazing incidence reflectivity of the W/C multilayers were measured. The imperfections at the interface such as interdiffusion and formation of compounds were dealt with by two methods. On analyzing the experimental results, we found that the incorporation of an interlayer was a more suitable method than the traditional statistical method to describe the layer structure of a W/C system we fabricated. The optical constants of each layer at a wavelength of 4.48 nm were also obtained from the analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Multiple indicator hidden Markov model with an application to medical utilization data
Authors: Wall Melanie M. , Li Ran
Published: November 2008

Monthly counts of medical visits across several years for persons identified to have alcoholism problems are modeled using two‐state hidden Markov models (HMM) in order to describe the effect of alcoholism treatment on the likelihood of persons to be in a ‘healthy’ or ‘unhealthy’ state. The medical visits can be classified into different types leading to multivariate counts of medical visits each month. A multiple indicator HMM is introduced, which simultaneously fits the multivariate Poisson counts by assuming a shared hidden state underlying all of them. The multiple indicator HMM borrows information across different types of medical encounters. A univariate HMM based on the total count across types of medical visits each month is also considered. Comparisons between the multiple indicator HMM and the total count HMM are made, as well as comparisons with more traditional longitudinal models that directly model the counts. A Bayesian framework is used for the estimation of the HMM and implementation is in Winbugs. Copyright © 2008 John Wiley & Sons, Ltd.
Zur probabilistischen Sicherheitsanalyse von Stabtragwerken nach der Theorie 2. Ordnung
Authors: Biehounek Josef , Grolik Helmut , Herz Susanne
Published: November 2008

Das probabilistische Bemessungsverfahren für Stabtragwerke geht aus der Deformationsmethode nach der Theorie 2. Ordnung hervor und bewahrt die auf dem Gleichgewicht der Kräfte und Drehmomente beruhende Praxis. Die Approximation zufälliger Lasten durch Hermitesche Polynome normalverteilter Zufallsgrößen führt mittels Galerkin‐Projektion auf ein lineares Gleichungssystem. Es beruht auf der Elastizitätsgleichung der deterministischen Deformationsmethode und muss iterativ behandelt werden. Das Verfahren lässt sich formalisieren und liefert die Versagenswahrscheinlichkeit mit einem im Berufsalltag des Bauingenieurs vertretbaren Aufwand. An Hand des Querschnittsversagens wird gezeigt, in welcher Hinsicht die probabilistische Analyse das mit Beiwerten arbeitende Sicherheitskonzept erweitert.
The symposium on urban popular culture in modern China
Authors: Min MA , Jin JIANG , Di WANG , Esherick Joseph W. , Hanchao LU
Published: November 2008

The studies of urban popular culture in modern China in recent years have attracted wide attention from scholars in China and abroad. The symposium, which is composed by Ma Min’s “Injecting vitality into the studies of urban cultural history,” Jiang Jin’s “Issues in the studies of urban popular culture in modern China,” Wang Di’s “The microcosm of Chinese cities: The perspective and methodology of studying urban popular culture from the case of teahouses in Chengdu,” Joseph W. Esherick’s “Remaking the Chinese city: Urban space and urban culture” and Lu Hanchao’s “From elites to common people: The downward trend in the studies of Chinese urban history in the United States,” provide valuable insights on the perspective, trend, and methodology of the studies.
Permanent Replacements and the End of Labor's “Only True Weapon”
Authors: Logan John
Published: November 2008

This article analyzes the origins and impact of one of the most powerful antiunion weapons used by American employers during the past four decades: the right to use and threaten to use permanent replacement workers during economic strikes. It examines the policy debate over replacements in the 1930s and 1940s, the increasing use of permanent replacements in the 1970s and 1980s, the growth of a powerful and sophisticated “strike management industry,” and the unsuccessful efforts of organized labor and its political allies to amend the National Labor Relations Act to outlaw permanent replacements. The article concludes with a brief discussion of the relationship between the “striker replacement doctrine” and declining strike levels in the postwar decades.
Regional variation in tropical forest tree species composition in the Central African Republic: an assessment based on inventories by forest companies
Authors: Réjou-Méchain Maxime , Pélissier Raphaël , Gourlet-Fleury Sylvie , Couteron Pierre , Nasi Robert , Thompson John D.
Published: November 2008

Understanding how species assemblages are structured in relation to environmental variation is a central issue in community ecology. However, factors that create regional variation in relative species abundances have been little studied due to the rarity of large-scale datasets. Here, we investigated a large dataset (30 180 0.5-ha plots spread over 1 600 000 ha) gathered from forest planning inventories in the semi-deciduous forest of the south western Central African Republic. We used Correspondence Analysis and Non-Symmetric Correspondence Analysis on Instrumental Variables to analyse variation in the abundance of 73 common tree species in relation to soil type, rainfall and proximity to villages. Together, environmental variables explained 10.3% of multi-species floristic variation among plots, and the regional spatial structure almost disappeared when the effects of these variables were removed. A Trend Surface Analysis using a third order polynomial function of the geographical coordinates of the plots explained 14.5% of the floristic variation and more than 75% of this variation was explained by environmental variables. Sandy soil was the most influential factor affecting floristic composition. Residual spatial variation not explained by the environmental variables probably reflects the natural and anthropogenic history of the vegetation.
Is Second Language Attrition the Reversal of Second Language Acquisition?
Authors: Olshtain Elite
Published: November 2008

The study of language attrition, whether it is concerned with first or second languages, focuses on the effects resulting from an individual's reduced use of the attrited language. Such reduction in use can be due to a change in the linguistic environment or to the termination of an instructional program. In either case, some other language (or languages) is or becomes the dominant one.

The present article reports on a series of studies, all focusing on individual attrition of English as a second language (ESL) in an environment where Hebrew is the dominant language. The predictor variables discussed are age, sociolinguistic features, input variables, and linguistic variables. The attrition process affecting English as a second language in a Hebrew dominant context seems to exhibit two major trends of change in language use: (a) a greater variability in the application of peripheral and highly marked structural rules, and (b) lower accessibility of specific lexical items. In each of these trends one can identify a limited reversal of the acquisition process, particularly with young children (5–8-year-olds) as well as a typological transfer process from the dominant language.
Quelques remarques sur la notion de situation en linguistique appliquee a la didactique des langues
Authors: Coste Daniel
Published: November 2008

La notion de situation a eu en linguistique appliquée à la didactique des langues un succès singulier, qui ne tenait sans doute ni à une définition précise et opérante (encore que, dans ce domaine comme dans certains autres, la circulation des concepts s'accommode facilement de leur flou relatif) ni à une richesse d'applications pédagogiques qui eût suffi à la justifier empiriquement (à bien des égards, l'enseignement des langues vivantes a préconisé des choix méthodologiques d'inspiration fort peu ‘situationnelle’).
Social Psychological Mechanisms Underlying Native Speaker Evaluations of Non-Native Speech
Authors: Ryan Ellen Bouchard
Published: November 2008

Research concerning native speaker reactions to the speech of language learners has generally flowed from an interpersonal perspective (i.e. speaker/listener). On the other hand, the broader social psychological domain of language attitude research has typically been based on an intergroup perspective (i.e. ingroup/outgroup). The two perspectives are elaborated here and shown to provide complementary interpretations of evaluations of non-native speech. From the intergroup viewpoint, evaluations are based upon two processes: identification of the speaker's social group attributes and group-based inferences. The particularly complex role of identification for non-native speakers is discussed in detail. Within the interpersonal sphere, inferences regarding speaker competence and generalized negative affect are emphasized.
Second Language Fluency and the Subjective Evaluation of Officer Cadets in a Military College
Authors: Olynyk Marian , Sankoff David , d'Anglejan Alison
Published: November 2008

The present study investigated the role of first and second language fluency in subjective judgments of linguistic, social and professional competence of adult bilinguals in a military setting. We examined the use of five types of speech marker, commonly referred to as hesitation phenomena, among ten Francophone officer-cadets in their native and second language, English. The results confirmed the experimenters' a priori classification of the subjects as high or low fluency speakers. Anglophone and Francophone peer judges of various levels of proficiency in their second language listened to a tape assembled of fifteen second segments of each subject's speech production in the native and second language and completed a questionnaire composed of ten scales evaluating the subjects in three domains: linguistic, social, and professional. The results showed that the eighty-six judges evaluated the subjects more positively in their native than in their second language guises in all three areas. High fluency speakers were evaluated more highly than low fluency speakers. Judges reactions were shown to vary as a function of their degree of bilingualism and their minority versus majority group membership.
Proficiency
Authors: Lantolf James P. , Frawley William
Published: November 2008

In this article we argue against a definitional approach to oral proficiency and in favor of a principled approach based on sound theoretical considerations. We first identify four problematic frends in the oral proficiency movement as it is currently conceived: the tail wagging the dog, false authenticity, premature institutionalization, and the psychometric posture. Thereafter, we offer the rudiments of a principled theory of oral proficiency, based on the theory of higher forms of human cognitive activity developed by the Vygotskyan school of psycholinguistics. The theory compels us to bring into focus such factors as open systems, the individual speaker, functional systems, and intersubjectivity. From this perspective, we argue that if the construct of oral proficiency is to have any significance at all for language teaching and testing, researchers must come to understand what it means for real speakers (natives as well as nonnatives) to interact with other real speakers in the everyday world of human activity rather than in the world circumscribed by language tests.
Parsing Effects in Second Language Sentence Processing
Authors: Juffs Alan , Harrington Michael
Published: November 2008

This paper reexamines claims that second language learners are more accurate at judging long-distance object extraction than subject extraction and that the difference in accuracy is due to processing factors rather than differences in underlying competence. Although previous studies have reported robust effects for the subject/object asymmetry, the global nature of the response measures leaves open the question of whether the subject gap is in fact the locus of difficulty for second language learners. Using many of the same stimuli sentences from original research in combination with a theory of principle-based parsing, this study employs the moving window display technique to collect on-line measures of processing long-distancewh-extraction. Twenty-five advanced Chinese-speaking ESL learners provided grammaticality judgments in two presentation conditions: full-sentence, where judgment reaction times are measured from sentence onset to the learner's judgment; and word-by-word reading, where word-by-word latencies are collected in addition to judgments. The accuracy and reaction time results from the full-sentence condition replicated previous findings. The word-by-word results confirm that it is the subject gap that is the source of difficulty for the learners. Claims in the literature that principles of Universal Grammar are not available to adult learners are not supported by these results, which show that parsing, and not grammatical competence, is the source of difficulty on performance with subject extraction sentences.
On the generalisation of a theorem of Steiner
Authors: Baker H. F.
Published: November 2008

The theorem that, if four arbitrary lines be taken in a plane, the four circles about the triangles formed by threes of these lines, meet in a point, can be generalised to space of any even number of dimensions, as was recognised by Mr J. H. Grace in 1897. In the plane case the centres of the four circles lie on another circle passing through the point of concurrence of these four; it has been sought to prove that the centres of the n + 2 spheres, similarly arising in space of an even number, n, of dimensions, also lie on a sphere†.
A note on k-3 caps in three-dimensional Galois space
Authors: Bramwell Dennis
Published: November 2008

A k-3 cap in a three-dimensional Galois space, S3,q, is a set of k points, of which some 3, but no 4 are collinear. It is shown in (2) that for q ≥ 4
.
Fubini and martingale theorems in C* -algebras
Authors: Batty C. J. K.
Published: November 2008

The basic integration theory of Radon measures on locally compact spaces, as described in (5), has been developed in various directions both in commutative and non-commutative analysis. Thus if Ω is a compact Hausdorff space, and C(Ω) denotes the space of continuous complex-valued functions on Ω, Kaplan (16) showed how topological measure theory can be performed in the second dual C(Ω)** of C(Ω). Here as usual C(Ω)* is identified with the space of Radon measures on Ω by associating with a measure μ the linear functional φμ where

Thus if f is a bounded real-valued function on Ω, there is an affine function f* defined on the set P(Ω) of Radon probability measures μ on Ω, by

and f* extends by linearity to a functional in C(Ω)**. Conversely any function x on P(Ω) determines a function x0 on Ω. by

wehere εω is the unit point of mass at ω.
On Banach algebra elements of thin numerical range
Authors: Smith R. R.
Published: November 2008

Among the elements of a complex unital Banach algebra the real subspace of hermitian elements deserves special attention. This forms the natural generalization of the set of self-adjoint elements in a C*-algebra and exhibits many of the same properties. Two equivalent definitions may be given: if W(h) ⊂ , where W(h) denotes the numerical range of h (7), or if ║eiλh║ = 1 for all λ ∈ . In this paper some related subsets are introduced and studied. For δ ≥ 0, an element is said to be a member of if the condition

is satisfied. These may be termed the elements of thin numerical range if δ is small.
On an urn problem of Paul and Tatiana Ehrenfest
Authors: Takács Lajos
Published: November 2008

A short solution is given for the urn problem proposed by Paul and Tatiana Ehrenfest in 1907.

In 1907 P. and T. Ehrenfest(3) proposed an urn model for the resolution of the apparent discrepancy between irreversibility and recurrence in Boltzmann's theory of gases (2). In this model it is assumed that m balls numbered 1, 2, …, m are distributed in two boxes. We perform a series of trials. In each trial we choose a number at random among 1, 2, …, m in such a way that each number has probability 1/m. If we choose j, then we transfer the ball numbered j from one box to the other. Denote by ξn the number of balls in the first box at the end of the nth trial. Initially there are ξ0 balls in the first box. If the trials are independent, then the sequence {ξn;n = 0, 1, 2,…} forms a homogeneous Markov chain with state space I = {0, 1, 2,…, m} and transition probabilities pi,i+1 = (m − i)/m for i = 0, l,…, m − 1, Pi,i−1 = i/m for i = 1, 2,…, m, and pi,k = 0 otherwise. The problem is to determine the transition probabilities

for i∈I, k∈I and n = 0,1, 2,….