bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental factors associated with long-term changes in chlorophyll-a concentration in the Amazon floodplain
Authors: Alcântara E. , Novo E. M. , Barbosa C. F. , Bonnet M.-P. , Stech J. , Ometto J. P.
Published: April 2011

Abstract. Long-term environmental time series of continuously collected data are fundamental to identify and classify pulses and determine their role in aquatic systems. This paper presents in situ daily mean chlorophyll-a concentration time series, key information for the current understanding of carbon fluxes in and out of the Amazonian floodplain system. This paper also investigates how seasonal fluctuations in water level affect the relationship between chlorophyll-a concentration and some of its controlling limnological (water level, water surface temperature, pH and turbidity) and meteorological (wind intensity, relative humidity and short wave radiation) variables provided by an automatic monitoring system (Integrated System for Environmental Monitoring-SIMA) deployed at Curai Lake. The data are collected in preprogrammed time interval (1 h) and are transmitted by satellite in quasi-real time for any user in a range of 2500 km from the acquisition point. We used Pearson correlation to determine the quantitative relationship between chlorophyll-a time series and others environmental parameters. Fourier power spectrum analyses were applied to identify periods of high variability in chlorophyll-a time series and wavelet power spectrum analyses helped to characterize their time-frequency structure. To further investigate the relationship between chlorophyll-a and the statistically significant variable highlighted by Pearson's correlation, the set of time series was submitted to cross wavelet analysis. The time series of chlorophyll-a shows two high peaks (47 μg L−1 and 53.30 μg L−1) of concentration during a year: first during the rising water and second during the low water level. A small peak was observed during the high water level (10 μg L−1). For the most part of rising, high and receding water level, the chlorophyll-a concentration is often low (from 2.20 μg L−1 to 9.10 μg L−1). chlorophyll-a concentration displays periodicities ranging from 2–60 days, with a coherence of approximately 1 in phase with water level during the rising and low water period. Water level dynamics and turbidity explain 68% of the chlorophyll-a time series variability.
Thermal anomalies detection before strong earthquakes (M > 6.0) using interquartile, wavelet and Kalman filter methods
Authors: Saradjian M. R. , Akhoondzadeh M.
Published: April 2011

Abstract. Thermal anomaly is known as a significant precursor of strong earthquakes, therefore Land Surface Temperature (LST) time series have been analyzed in this study to locate relevant anomalous variations prior to the Bam (26 December 2003), Zarand (22 February 2005) and Borujerd (31 March 2006) earthquakes. The duration of the three datasets which are comprised of MODIS LST images is 44, 28 and 46 days for the Bam, Zarand and Borujerd earthquakes, respectively. In order to exclude variations of LST from temperature seasonal effects, Air Temperature (AT) data derived from the meteorological stations close to the earthquakes epicenters have been taken into account. The detection of thermal anomalies has been assessed using interquartile, wavelet transform and Kalman filter methods, each presenting its own independent property in anomaly detection. The interquartile method has been used to construct the higher and lower bounds in LST data to detect disturbed states outside the bounds which might be associated with impending earthquakes. The wavelet transform method has been used to locate local maxima within each time series of LST data for identifying earthquake anomalies by a predefined threshold. Also, the prediction property of the Kalman filter has been used in the detection process of prominent LST anomalies. The results concerning the methodology indicate that the interquartile method is capable of detecting the highest intensity anomaly values, the wavelet transform is sensitive to sudden changes, and the Kalman filter method significantly detects the highest unpredictable variations of LST. The three methods detected anomalous occurrences during 1 to 20 days prior to the earthquakes showing close agreement in results found between the different applied methods on LST data in the detection of pre-seismic anomalies. The proposed method for anomaly detection was also applied on regions irrelevant to earthquakes for which no anomaly was detected, indicating that the anomalous behaviors can be related to impending earthquakes. The proposed method receives its credibility from the overall capabilities of the three integrated methods.
The Prevalence of Dysplasia in Femoroacetabular Impingement
Authors: Paliobeis Christos P. , Villar Richard N.
Published: April 2011

It is unknown how often femoro-acetabular impingement (FAI) and hip dysplasia co-exist and which is more important in the development of intra-articular lesions such as labral tears. This study identified the prevalence of dysplasia on standard radiographs in a group of 76 consecutive patients with symptomatic FAI. The centre-edge (CE) angle of Wiberg, the acetabular angle (AA) of Sharp, FAI type, offset ratio and posterior wall sign were identified.

63 patients, predominantly young adult males (mean age: 34.6 years; 10:4 male-to-female ratio), met our inclusion criteria. Most females (13:18) showed signs of dysplasia based on the AA. No association of dysplasia with FAI group, offset ratio or posterior wall sign was found. 47% of our patients with FAI also had radiographic evidence of dysplasia (3–15% definite and 9–30% borderline, depending on the angle utilised).

Surgery for FAI should therefore take into account the presence of co-existing dysplasia. Conversely, surgery for dysplasia should take into consideration the co-existence of FAI. The prime cause of labral pathology in the presence of dysplasia may be co-existent FAI and the latter problem may demand priority, not the former.
Characteristics of Heat Transfer for Heat Pipe and Its Correlation
Authors: Mozumder Aloke Kumar , Chowdhury Mohammed Shafiul Hasib , Akon Abul Fahad
Published: April 2011

In spite of wide application of heat pipe in microelectronics cooling system, a complete understanding of heat pipe mechanism has not yet been completed. An experimental investigation of heat transfer performance of a heat pipe for dry condition and with three different liquids as acetone, methanol, and water having four fill ratios, for each liquid has been conducted in the present study. The heat pipe was 5 mm in diameter and 150 mm long with a thermal capacity of 10 W. The evaporator and condenser's temperatures were measured with varying input power to estimate the heat transfer coefficient. This study reveals that the dominating parameters for the heat transfer coefficient are evaporator surface temperature, saturated boiling temperature of working fluid, latent heat of vaporization, and fill ratio. The investigation also shows that 85% fill ratio can be regarded as an optimum value for a heat pipe. A new correlation for the heat transfer coefficient has been proposed here which fairly agrees with the experimental results.
Studies on Wound Healing Activity ofHeliotropium indicumLinn. Leaves on Rats
Authors: Dash G. K. , Murthy P. N.
Published: April 2011

The petroleum ether, chloroform, methanol, and aqueous extracts ofHeliotropium indicumLinn. (Family: Boraginaceae) were separately evaluated for their wound healing activity in rats using excision (normal and infected), incision, and dead space wound models. The effects of test samples on the rate of wound healing were assessed by the rate of wound closure, period of epithelialisation, wound breaking strength, weights of the granulation tissue, determination of hydroxyproline, super oxide dismutase (SOD), catalase, and histopathology of the granulation tissues. Nitrofurazone (0.2% w/w) in simple ointment I. P. was used as reference standard for the activity comparison. The results revealed significant promotion of wound healing with both methanol and aqueous extracts with more promising activity with the methanol extract compared to other extracts under study. In the wound infection model (withS. aureusandP. aeruginosa), the methanol extract showed significant healing activity similar to the reference standard nitrofurazone. Significant increase in the granulation tissue weight, increased hydroxyproline content, and increased activity of SOD and catalase level with the animals treated with methanol extract in dead space wound model further augmented the wound healing potential ofH. indicum. The present work substantiates its validity of the folklore use.
Preparation and Analysis of Glycan Microarrays
Authors: Heimburg‐Molinaro Jamie , Song Xuezheng , Smith David F. , Cummings Richard D.
Published: April 2011

Determination of the binding specificity of glycan‐binding proteins (GBPs), such as lectins, antibodies, and receptors, has traditionally been difficult and laborious. The advent of glycan microarrays has revolutionized the field of glycobiology by allowing simultaneous screening of a GBP for interactions with a large set of glycans in a single format. This unit describes the theory and method for production of two types of glycan microarrays (chemo/enzymatically synthesized and naturally derived), and their application to functional glycomics to explore glycan recognition by GBPs. These procedures are amenable to various types of arrays and a wide range of GBP samples. Curr. Protoc. Protein Sci. 64:12.10.1‐12.10.29. © 2011 by John Wiley & Sons, Inc.
Nucleic Acid Programmable Protein Arrays: Versatile Tools for Array‐Based Functional Protein Studies
Authors: Miersch Shane , LaBaer Joshua
Published: April 2011

Protein microarrays offer a global perspective on the function of expressed gene products. However, technical issues related to the stability and dynamic range of microarrays printed with purified protein have hampered their widespread adoption. Taking an alternate approach, the Nucleic Acid Programmable Protein Array (NAPPA) is constructed by spotting protein‐encoding plasmid DNA at high density, in addressable fashion, on an array surface. Proteins are subsequently generated in situ just prior to experimentation using cell‐free expression systems. As such, the NAPPA platform offers a unique and viable alternative that circumvents many of the inherent limitations of spotted protein arrays, enabling diverse functional protein studies including protein–small molecule, protein‐protein, antigen‐antibody, and protein–nucleic acid interactions. It further offers a versatile and adaptable platform amenable to a variety of capture modalities and expression systems, and, most importantly, construction of the array is accessible to any lab with an array printer and laser slide scanner. This unit is intended to provide a reference for investigators wishing to generate arrays based on this platform, and details (1) the basic construction of cDNA‐based protein microarrays from DNA isolation to printing and development, (2) quality‐control efforts taken to ensure the usefulness and integrity of microarray data, and (3) a particular example of the application of self‐assembling protein arrays to screen for blood‐borne antibody biomarkers. Curr. Protoc. Protein Sci. 64:27.2.1‐27.2.26. © 2011 by John Wiley & Sons, Inc.
Influence of Transport Mechanisms on Macrosegregation Formation in Direct Chill Cast Industrial Scale Aluminum Alloy Ingots
Authors: Založnik Miha , Kumar Arvind , Combeau Hervé , Bedel Marie , Jarry Philippe , Waz Emmanuel
Published: April 2011

The phenomena responsible for the formation of macrosegregations and grain structures during solidification are closely related. We present a model study of macrosegregation formation in an industrial sized (350 mm thick) direct chill (DC) cast aluminum alloy slab. The modeling of these phenomena in DC casting is a challenging problem mainly due to the size of the products, the variety of the phenomena to be accounted for, and the nonlinearities involved. We used a volume‐averaged two‐phase multiscale model that describes nucleation on grain refiner particles and grain growth, fully coupled with macroscopic transport: fluid flow driven by natural convection and shrinkage, transport of free‐floating equiaxed grains, heat transfer, and solute transport. The individual and combined roles of shrinkage, natural convection, and grain motion on the sump profile and macrosegregation formation are analyzed. The formation and evolution of grains are discussed. We show that it is important to account for all the named transport mechanisms to be able to explain the macrosegregation pattern observed experimentally in DC cast ingots.
Localized Ligand Induced Electroless Plating (LIEP) Process for the Fabrication of Copper Patterns Onto Flexible Polymer Substrates
Authors: Garcia Alexandre , Polesel‐Maris Jérôme , Viel Pascal , Palacin Serge , Berthelot Thomas
Published: April 2011

The “ligand induced electroless plating (LIEP) process” is a simple process to obtain localized metal plating onto flexible polymers such as poly(ethylene terephtalate) and polyvinylidene fluoride sheets. This generic and cost‐effective process, efficient on any common polymer surface, is based on the covalent grafting by the GraftFast process of a thin chelating polymer film, such as poly(acrylic acid), which can complex copper ions. The entrapped copper ions are then chemically reduced in situ and the resulting Cu0 species act as a seed layer for the electroless copper growth which, thus, starts inside the host polymer. The present work focuses on the application of the LIEP process to the patterning of localized metallic tracks via two simple lithographic methods. The first is based on a standard photolithography process using a positive photoresist masking to prevent the covalent grafting of PAA in designated areas of the polymer substrate. In the second, the patterning is performed by direct printing of the mask with a commercial laser printer. In both cases, the mask was lifted off before the copper electroless plating step, which provides ecological benefits, since only the amount of copper necessary for the metallic patterning is used.
Complex Faraday Rotation in Microstructured Magneto‐optical Fiber Waveguides
Authors: Schmidt Markus A. , Wondraczek Lothar , Lee Ho W. , Granzow Nicolai , Da Ning , Russell Philip St. J.
Published: April 2011

Magneto‐optical glasses are of considerable current interest, primarily for applications in fiber circuitry, optical isolation, all‐optical diodes, optical switching and modulation. While the benchmark materials are still crystalline, glasses offer a variety of unique advantages, such as very high rare‐earth and heavy‐metal solubility and, in principle, the possibility of being produced in fiber form. In comparison to conventional fiber‐drawing processes, pressure‐assisted melt‐filling of microcapillaries or photonic crystal fibers with magneto‐optical glasses offers an alternative route to creating complex waveguide architectures from unusual combinations of glasses. For instance, strongly diamagnetic tellurite or chalcogenide glasses with high refractive index can be combined with silica in an all‐solid, microstructured waveguide. This promises the implementation of as‐yet‐unsuitable but strongly active glass candidates as fiber waveguides, for example in photonic crystal fibers.
Grafting onto carbohydrate polymer using novel potassium persulfate/tetramethylethylene diamine redox system for initiating grafting
Authors: Mostafa KH. M. , Samarkandy Abdul Rahim , El‐Sanabary A. A.
Published: April 2011

Starch as one of the most abundant, renewable, low‐cost, and biodegradable carbohydrate polymers worldwide suffers from some drawbacks: The most important one is that it lacks properties of synthetic polymers. So, modification of starch by graft copolymerization will provide a substantial modification route to alter physical and chemical properties of starch, thereby increasing its utilization, by attaching a flexible synthetic polymer onto the rigid natural polysaccharide backbone without greatly changing the latter. In addition to the main disadvantage of the above technique, the high percentage of homopolymer and low percentage of grafting are other disadvantages. At this point, our research team focused on how to maximize the graft yields and graft reaction efficiency percentage, minimize the homopolymer percentage, as well as enhance the water solubility of the prepared copolymers. Based on the results obtained, appropriate conditions for grafting methacrylic acid onto pregelled starch were established and the graft yield was higher under the following conditions: 10 mmol/L potassium persulfate (KPS); 8 mmol/L tetramethylethylene diamine (TMEDA) 50% methacrylic acid concentration (based on weight of substrate); liquor ratio, 10; reaction time, 60 min; and polymerization temperature, 60°C. On the other hand, grafting was significantly enhanced by adding Fe3+, Cu2+, and Li+ in the grafting media and it follows the following order: Fe3+ > Cu2+ > Li+, in addition to the solubility percentage. Approximately 37.5% graft yield and 75% graft reaction efficiency as well as 25% homopolymerization were obtained when methacrylic acid was graft copolymerized onto pregelled starch as a reactive carbohydrate polymer using a new redox initiation system, namely KPS/TMEDA redox pair. Furthermore, a notable enhancement was observed in solubility percentage of grafted samples with lower graft yields than that of the higher one. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 138–149, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20210
Blending polylactic acid with polyhydroxybutyrate: The effect on thermal, mechanical, and biodegradation properties
Authors: Zhang Min , Thomas Noreen L.
Published: April 2011

Blends of polylactic acid (PLA) and polyhydroxybutyrate (PHB) at a number of different PLA/PHB weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) have been prepared by melt compounding. The morphology, thermal properties, mechanical properties, and biodegradation behavior of these blends have been investigated. The results indicate that PLA/PHB blends are immiscible but exhibit molecular interaction. PHB is highly crystallizable, and it enhances the recrystallization of PLA and consequently increases the heat distortion temperature. Adding PLA to PHB improves the mechanical properties of PHB. In fact, blending with PHB is also a viable approach to improve the mechanical properties of PLA because the PLA/PHB 75/25 blend exhibits significantly improved tensile properties compared with pure PLA. This is due to the finely dispersed PHB crystals acting as a filler and nucleating agent in PLA. The biodegradability, studied by weight change measurement at room temperature, improved with increasing PHB content. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 67–79, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20235
Assessing bioequivalence of generic antiepilepsy drugs
Authors: Krauss Gregory L. , Caffo Brian , Chang Yi‐Ting , Hendrix Craig W. , Chuang Kelly
Published: April 2011

Objective:

Patients with epilepsy are often concerned that switching between brand‐name and generic formulations of antiepilepsy drugs (AEDs) may cause clinically significant changes in plasma drug concentrations. We assessed bioequivalence (BE) studies for approved generic AEDs to evaluate US Food and Drug Administration claims that: (1) generic AEDs are accurate copies of reference formulations; (2) delivery of reference formulations may be as variable as generic AEDs and so provide no increased benefit; and (3) switches between generic AED formulations are safe and effective.

Methods:

We determined differences in 90% confidence interval limits for total drug exposure (AUC0‐t) and peak concentration (Cmax) ratios of generic and reference formulations during fasting and fed BE studies. We simulated BE between generic formulations after adjusting for reference values.

Results:

AUC0‐t values of approved reference and generic formulations differed by <15% in 99% of BE studies; Cmax differed by <15% in 89% of studies. Food affected variability of Cmax but not AUC0‐t. Intersubject variability in Cmax and AUC0‐t was small and similar for reference and generic products. In simulated switches between 595 pairs of generic AED formulations, estimated AUC0‐t differed by >15% for 17% of pairs; estimated Cmax differed by >15% for 39%. AEDs with low bioavailability and solubility (eg, oxcarbazepine) had the greatest variability in BE.

Interpretation:

Most generic AED products provide total drug delivery (AUC) similar to reference products; differences in peak concentrations between formulations are more common. Switches between generic AED products may cause greater changes in plasma drug concentrations than generic substitutions of reference products. ANN NEUROL 2011
Gelatinases (MMP2 and MMP9) in swine antral follicle
Authors: Basini Giuseppina , Bussolati Simona , Baioni Laura , Grasselli Francesca
Published: April 2011

Follicular growth is allowed by extracellular matrix remodeling and vascular network development. Since matrix metalloproteinases (MMPs) play a crucial role in both of these processes, the aim of the present study was to evaluate the expression of gelatinases MMP2 and MMP9 in swine ovarian follicle (theca and granulosa compartments) during its development. Moreover, we measured gelatinase activities into follicular fluids (FF). Our data demonstrate for the first time that MMP2 and MMP9 are expressed in swine ovarian follicle both in theca and granulosa layers; moreover we show that the expression of both gelatinases increases in theca while decreases in granulosa during follicle growth. Additionally, MMP2 activity has been detected in FF. The spatial pattern of expression of gelatinases in swine follicle suggests a differential role during physiological ovarian events.
Incidence of cardiovascular events and death after open or endovascular repair of abdominal aortic aneurysm in the randomized EVAR trial 1
Authors: Brown L C , Thompson S G , Greenhalgh R M , Powell J T
Published: April 2011

Background

The aim was to compare rates of myocardial infarction, stroke and cardiovascular death in patients with a large abdominal aortic aneurysm who had endovascular (EVAR) or open repair to determine whether cardiovascular mortality explains the convergence in survival curves after these procedures.

Methods

Between 1999 and 2004, 1252 patients were randomized to EVAR or open repair in the UK EVAR trial 1. All patients were followed for death, myocardial infarction or stroke until September 2009. Cox regression was used to compare cardiovascular events and deaths between the randomized groups during different time intervals.

Results

Over 5 years of follow-up, a total of 187 first non-fatal or fatal cardiovascular events (98 myocardial infarctions and 89 strokes) and 256 cardiovascular deaths occurred. Although the endovascular group had a lower cardiovascular event rate than the open repair group (2·6 versus 3·2 per 100 person-years respectively) this was not statistically significant (adjusted hazard ratio (HR) 0·83, 95 per cent confidence interval 0·62 to 1·10; P = 0·199). Overall, there was little difference in cardiovascular mortality between the randomized groups (adjusted HR 1·06, 0·83 to 1·36; P = 0·638), but a non-significant excess of cardiovascular deaths was apparent in the endovascular group during the 6–24-month interval (adjusted HR 1·44, 0·79 to 2·62; P = 0·237).

Conclusion

Patients who had EVAR appeared to have a lower subsequent cardiovascular event rate during all time intervals. Cardiovascular mortality was similar between the two groups overall, but more cardiovascular deaths in the EVAR group appeared to contribute to the convergence in all-cause mortality during the first 2 years.
Characteristic facial retargeting
Authors: Song Jaewon , Choi Byungkuk , Seol Yeongho , Noh Junyong
Published: April 2011

Facial motion retargeting has been developed mainly in the direction of representing high fidelity between a source and a target model. We present a novel facial motion retargeting method that properly regards the significant characteristics of target face model. We focus on stylistic facial shapes and timings that reveal the individuality of the target model well, after the retargeting process is finished. The method works with a range of expression pairs between the source and the target facial expressions and emotional sequence pairs of the source and the target facial motions. We first construct a prediction model to place semantically corresponding facial shapes. Our hybrid retargeting model, which combines the radial basis function (RBF) and kernel canonical correlation analysis (kCCA)‐based regression methods copes well with new input source motions without visual artifacts. 1D Laplacian motion warping follows after the shape retargeting process, replacing stylistically important emotional sequences and thus, representing the characteristics of the target face. Copyright © 2011 John Wiley & Sons, Ltd.
Chemical Characterization (GC/MS and NMR Fingerprinting) and Bioactivities of South‐African Pelargonium capitatum (L.) L' Her. (Geraniaceae) Essential Oil
Authors: Guerrini Alessandra , Rossi Damiano , Paganetto Guglielmo , Tognolini Massimiliano , Muzzoli Mariavittoria , Romagnoli Carlo , Antognoni Fabiana , Vertuani Silvia , Medici Alessandro , Bruni Alessandro , Useli Chiara , Tamburini Elena , Bruni Renato , Sacchetti Gianni
Published: April 2011

Chemical fingerprinting of commercial Pelargonium capitatum (Geraniaceae) essential oil samples of south African origin was performed by GC, GC/MS, and 13C‐ and 1H‐NMR. Thirty‐seven compounds were identified, among which citronellol (32.71%) and geraniol (19.58%) were the most abundant. NMR Spectra of characteristic chemicals were provided. Broad‐spectrum bioactivity properties of the oil were evaluated and compared with those of commercial Thymus vulgaris essential oil with the aim to obtain a functional profile in terms of efficacy and safety. P. capitatum essential oil provides a good performance as antimicrobial, with particular efficacy against Candida albicans strains. Antifungal activity performed against dermatophyte and phytopathogen strains revealed the latter as more sensitive, while antibacterial activity was not remarkable against both Gram‐positive and Gram‐negative bacteria. P. capitatum oil provided a lower antioxidant activity (IC50) than that expressed by thyme essential oil, both in the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and β‐carotene bleaching tests. Results in photochemiluminescence (PCL) assay were negligible. To test the safety aspects of P. capitatum essential oil, mutagenic and toxicity properties were assayed by Ames test, with and without metabolic activation. Possible efficacy of P. capitatum essential oil as mutagenic protective agent against NaN3, 2‐nitrofluorene, and 2‐aminoanthracene was also assayed, providing interesting and significant antigenotoxic properties.
Volatile Compounds of Asphodelus microcarpusSalzm. et Viv. Honey Obtained by HS‐SPME and USE Analyzed by GC/MS
Authors: Jerković Igor , Tuberoso Carlo I. G. , Kasum Ana , Marijanović Zvonimir
Published: April 2011

Chemical analysis of Asphodelus microcarpus Salzm. et Viv. honey is of great importance, since melissopalynology does not allow the unambiguous determination of its botanical origin. Therefore, the volatile compounds of eight unifloral asphodel honeys have been investigated for the first time. The honey extracts were obtained by headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE) and analyzed by GC and GC/MS. In the honey headspace, 31 volatile compounds were identified with high percentages of 2‐phenylacetaldehyde (2; 14.8–34.7%), followed by somewhat lower percentages of methyl syringate (1; 10.5–11.5%). Compound 2 is not a specific marker of the botanical origin of the honey, but its high percentage can be emphasized as headspace characteristic of asphodel honey. The extraction solvent for all the samples was selected after extracting a representative sample with pentane, Et2O, pentane/Et2O 1 : 2 (v/v), and CH2Cl2. Compound 1 was the major constituent of all the USE extracts (46.8–87.0%). According to these preliminary results, all the honey samples were extracted by USE with the solvent pentane/Et2O 1 : 2. A total of 60 volatile compounds were identified with 1 as predominant compound (69.4–87.0%), pointing out 1 as Asphodelus honey volatile marker.
Molecular Aspects of Glucose Dehydration by Chromium Chlorides in Ionic Liquids
Authors: Zhang Yanmei , Pidko Evgeny A. , Hensen Emiel J. M.
Published: April 2011

A combined experimental and computational study of the ionic‐liquid‐mediated dehydration of glucose and fructose by CrII and CrIII chlorides has been performed. The ability of chromium to selectively dehydrate glucose to 5‐hydroxymethylfurfural (HMF) in the ionic liquid 1‐ethyl‐3‐methyl imidazolium chloride does not depend on the oxidation state of chromium. Nevertheless, CrIII exhibits higher activity and selectivity to HMF than CrII. Anhydrous CrCl2 and CrCl3⋅6 H2O readily catalyze glucose dehydration with HMF yields of 60 and 72 %, respectively, after 3 h. Anhydrous CrCl3 has a lower activity, because it only slowly dissolves in the reaction mixture. The transformation of glucose to HMF involves the formation of fructose as an intermediate. The exceptional catalytic performance of the chromium catalysts is explained by their unique ability to catalyze glucose to fructose isomerization and fructose to HMF dehydration with high selectivity. Side reactions leading to humins by means of condensation reactions take predominantly place during fructose dehydration. The higher HMF selectivity for CrIII is tentatively explained by the higher activity in fructose dehydration compared to CrII. This limits the concentration of intermediates that are involved in bimolecular condensation reactions. Model DFT calculations indicate a substantially lower activation barrier for glucose isomerization by CrIII compared to CrII. Qualitatively, glucose isomerization follows a similar mechanism for CrII and CrIII. The mechanism involves ring opening of D‐glucopyranose coordinated to a single Cr ion, followed by a transient self‐organization of catalytic chromium complexes that promotes the rate‐determining hydrogen‐shift step.
Application of Monte‐Carlo simulation to estimate the kinetic parameters for pyrolysis—Part I
Authors: Kaushal Priyanka , Abedi Jalal
Published: April 2011

A mathematical model was developed to represent pyrolysis. The components of primary and secondary pyrolysis reactions were simply lump into different groups and were represented through a set of pseudo‐first‐order reactions. This study presents an algorithm to estimate the kinetic parameters using Monte‐Carlo (MC) simulation. The combination of an analytical reaction model and the MC simulation technique rapidly generates a large number of numerical values. Results show that MC‐simulated data and experimental data are in fair agreement. Though the technique developed in this study proved to have potential, more experimental data are needed to check the robustness of the model. © 2011 Canadian Society for Chemical Engineering
Removal of reactive blue 19 and reactive blue 49 textile dyes by citrus waste biomass from aqueous solution: Equilibrium and kinetic study
Authors: Asgher Mahwish , Bhatti Haq Nawaz
Published: April 2011

The purpose of this study was to establish the potential of inexpensive and locally available biomaterial, that is, lignocellulosic waste of Citrus sinensis as biosorbent to remove reactive anthraquinone dyes from aqueous solution. The effects of immobilisation and chemical treatment of biosorbent were also explored for the enhanced sorption of dyes. Biosorbent was chemically treated with organic and inorganic reagents of which acetic acid augmented the sorption capacities for Reactive blue 19 and Reactive blue 49 attaining equilibrium in 60 min. While immobilisation of biosorbent into calcium alginate beads reduced the sorption capacity and the time to achieve equilibrium was prolonged up to 120 min. Sorption of both reactive dyes was found to be dependent on pH of media and maximum removal was observed at pH 2. The sorption process was fast and the data followed pseudo‐second‐order kinetic rate equation (R2 = 0.99). The equilibrium data were also fitted to Freundlich, Langmuir and Temkin isotherms. The mechanism of sorption was found to be physiosorption. FTIR analysis and SEM imaging of biosorbent were also carried out to study functional groups involved and morphological changes at the surface of biomass. © 2011 Canadian Society for Chemical Engineering
The limit of ethnocentric perceptions in civil war peace negotiations
Authors: Lee Sung Yong
Published: April 2011

This paper is an empirical study to demonstrate the effect of the ethnocentric cultures of both Western interveners and national warring factions on civil war peace negotiations. By examining the peace negotiations in Cambodia and Angola, it demonstrates that actors' cultural values have significant effects on the formation of their goals, domestic resources, interveners' pressure and incentives, and contents of peace proposals. This paper also reveals that the strategic decisions of the national factions in the two cases varied according to the combined effects of the four factors just mentioned.
The safety and tolerability of GLP‐1 receptor agonists in the treatment of type 2 diabetes: a review
Authors: Aroda Vanita R. , Ratner Robert
Published: April 2011

Although several classes of pharmacotherapy are available for type 2 diabetes, glycaemic control is often hampered by medication‐related adverse effects and contraindications such as renal impairment. Glucagon‐like peptide‐1 (GLP‐1) receptor agonists provide a new pharmacotherapeutic option based on the multiple glucose‐lowering effects of the human hormone GLP‐1. This mechanism of action not only provides therapeutic efficacy but also suggests that GLP‐1 receptor agonists have distinct safety and tolerability concerns compared with other diabetes therapies. Stimulation of pancreatic insulin secretion by GLP‐1 receptor agonists is glucose dependent, conferring a lesser risk of hypoglycaemia than that seen with sulfonylureas. Individual GLP‐1 receptor agonists differ in their metabolism and excretion profiles, affecting the choice of agent for patients with renal impairment. As with other protein‐based therapies, GLP‐1 receptor agonists may induce the formation of antibodies that may attenuate therapeutic efficacy and affect safety. Conclusions on cardiovascular safety must await outcomes studies, but at present no signal of harm has been reported, and preclinical data and effects on risk markers suggest a potential for benefit. Current data on thyroid medullary cancer in humans and pancreatic malignancy in rodents do not suggest that there is any reason to restrict the clinical use of GLP‐1 analogues in most people with diabetes. It is currently difficult to ascertain the possible contributory role of GLP‐1 receptor agonists in increasing the risk of pancreatitis, and vigilance for signs and symptoms is prudent. Primary tolerability issues include transient gastrointestinal symptoms, common with GLP‐1 receptor agonists, which can be reduced through dose titration. Copyright © 2011 John Wiley & Sons, Ltd.
A study of modeling of EMTP analysis for indoor distribution line
Authors: Abe Toshiya , Tsuboi Toshihiro , Sakamoto Yoshiki , Miyazaki Teru , Okabe Shigemitsu
Published: April 2011

Damage to home electric appliances due to lightning surges has recently become more common. The installation of SPDs (surge protective devices) in interior wiring is a countermeasure against damage and is also becoming more widespread after amendment of the regulation on indoor wires in 2005. Past study showed an effective method in which the earth line of the SPD is connected with that of home appliances and is grounded at one place in the home. However, because the methods of installing the distribution line in homes vary, it is difficult to estimate the effect of SPDs in every home, and high‐precision analysis by EMTP for interior wiring and SPD in the home is required. In this study, experiments were conducted with interior wiring and varistors, which constitute SPDs, and this paper reports the results of those experiments and of EMTP analytical models. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(4): 24–33, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21062
TSLP enhances the function of helper type 2 cells
Authors: Kitajima Masayuki , Lee Hai‐Chon , Nakayama Toshinori , Ziegler Steven F.
Published: April 2011

The cytokine thymic stromal lymphopoietin (TSLP) has been implicated in the development and progression of allergic inflammation in both humans and mice. TSLP has been shown to promote a Th2‐type response through upregulation of OX40L on dendritic cells, and through direct induction of IL‐4 production in naïve CD4+ T cells. However, its direct effect on effector Th cells has not been extensively investigated. In this study, we show that the level of TSLP receptor (TSLPR) expression on mouse effector Th2 cells is higher than on Th1 and Th17 cells, and that TSLP induced proliferation of effector Th2, but not Th1 nor Th17 cells. TSLP also induced the phosphorylation of signal transducer and activator of transcription (Stat) 5, and expression of the anti‐apoptotic factor Bcl‐2 in Th2 cells. Finally, TSLP‐mediated proliferation on Th2 cells was enhanced by TCR stimulation, through IL‐4‐mediated induction of TSLPR expression. Taken together, these results indicate that TSLP is involved in exacerbation of mouse Th2‐mediated allergic inflammation in a Th2 environment through direct stimulation of Th2 effector cells.
Organocatalyzed Enantioselective Synthesis of Quaternary Carbon‐Containing Isoindolin‐1‐ones
Authors: Yu Xiaolei , Wang Youming , Wu Guiping , Song Haibin , Zhou Zhenghong , Tang Chuchi
Published: April 2011

3,3′‐Triphenylsilyl‐substituted (S)‐BINOL‐based (1,1′‐bi‐2‐naphthol) phosphoric acid has proven to be an effective organocatalyst for the asymmetric Friedel–Crafts alkylation of indoles with 3‐substituted 3‐hydroxyisoindolin‐1‐ones, affording the corresponding quaternary carbon‐containing 3,3‐disubstituted isoindolin‐1‐ones in good yields (up to 99 %) with good to excellent enantioselectivities (up to 95 % ee). The optical purity of the product was further improved after a single recrystallization. This protocol provides a convenient method for the catalytic asymmetric synthesis of valuable 3,3‐disubstituted isoindolin‐1‐ones in high yields and enantioselectivities.
Sensitive Hydrazine Detection Using a Porous Mn2O3 Nanofibers‐Based Sensor
Authors: Ding Yu , Hou Changjun , Li Baikun , Lei Yu
Published: April 2011

Following a facile two‐step synthetic route (electrospinning and subsequent calcination), highly porous Mn2O3 nanofibers (Ø 105 nm) were fabricated. The as‐prepared Mn2O3 nanofibers were applied to construct an amperometric sensor for hydrazine detection in neutral phosphate buffer. The developed hydrazine sensor showed a fast response time (within 5 s), a wide linear range up to 644 µM, a high sensitivity of 474 µA mM−1 cm−2, a good limit of detection of 0.3 µM (S/N=3) as well as good reproducibility and selectivity. These results demonstrate that Mn2O3 nanofibers have great potential in the application of hydrazine detection.
Smoothed Particle Hydrodynamics: Approximate zero‐consistent 2‐D boundary conditions and still shallow‐water tests
Authors: Vacondio R. , Rogers B. D. , Stansby P. K.
Published: April 2011

smoothed particle hydrodynamics; boundary conditions; shallow water equations; source terms; virtual boundary particles; still waterIn this paper, an approximate modified virtual boundary particle method (MVBP) for solid boundary conditions in a two‐dimensional (2‐D) smoothed particle hydrodynamics (SPH) model is presented; this is a development of the original VBP method recently proposed by Ferrari et al. (Comput. Fluids 2009; 38(6): 1203–1217). The aim is to maintain the zeroth moment of the kernel function as closely as possible to unity, a property referred to as zero‐consistency, for particles close to solid boundaries. The performance of the new method in approximating zero‐consistency in the presence of complicated boundaries is demonstrated where we show that the MVBP method improves the accuracy of the zeroth moment by almost an order of magnitude. Shallow‐water flows are an important two‐dimensional (2‐D) application and provide the simple test case of still water. The shallow‐water equations (SWEs) are thus considered in SPH form and the zero‐consistency approximation is tested for still water in domains with different boundaries: a circle and two squares, one with an additional internal angle of 300∘ and one with four internal angles of 345∘. We demonstrate that for an internal angle of 300∘, the MVBP method demonstrates numerical convergence to still‐water conditions whereas both mirror particles and the VBP method cannot. The method is also demonstrated for the dynamic case of a circular dam break interacting with an outer circular wall where conventional mirror particles fail to prevent particles passing through the solid wall. The SPH SWEs are further generalized through a new method for discretizing the bed source term allowing arbitrarily complicated bathymetries. The resulting formulation is tested by considering many different bed shapes in still water: submerged and surface‐piercing humps, a submerged step, a submerged and surface‐piercing parabolic bed. Copyright © 2011 John Wiley & Sons, Ltd.
Phase precession and variable spatial scaling in a periodic attractor map model of medial entorhinal grid cells with realistic after‐spike dynamics
Authors: Navratilova Zaneta , Giocomo Lisa M. , Fellous Jean‐Marc , Hasselmo Michael E , McNaughton Bruce L.
Published: April 2011

We present a model that describes the generation of the spatial (grid fields) and temporal (phase precession) properties of medial entorhinal cortical (MEC) neurons by combining network and intrinsic cellular properties. The model incorporates network architecture derived from earlier attractor map models, and is implemented in 1D for simplicity. Periodic driving of conjunctive (position × head‐direction) layer‐III MEC cells at theta frequency with intensity proportional to the rat's speed, moves an ‘activity bump’ forward in network space at a corresponding speed. The addition of prolonged excitatory currents and simple after‐spike dynamics resembling those observed in MEC stellate cells (for which new data are presented) accounts for both phase precession and the change in scale of grid fields along the dorso‐ventral axis of MEC. Phase precession in the model depends on both synaptic connectivity and intrinsic currents, each of which drive neural spiking either during entry into, or during exit out of a grid field. Thus, the model predicts that the slope of phase precession changes between entry into and exit out of the field. The model also exhibits independent variation in grid spatial period and grid field size, which suggests possible experimental tests of the model. © 2011 Wiley Periodicals, Inc.
Triethylamine‐Catalyzed Efficient Synthesis of Oxathiolanes Containing a Highly Polarized Carbon‐Carbon Double Bond from Reaction of Malononitrile, Carbon Disulfide (CS2), and Oxiranes
Authors: Yavari Issa , Ghazanfarpour‐Darjani Majid , Solgi Yazdan , Ahmadian Salomeh
Published: April 2011

An efficient synthesis of functionalized 2‐(1,3‐oxathiolan‐2‐ylidene)malononitriles containing a push‐pull CC bond via a simple reaction between malononitrile, CS2, and oxiranes in the presence of Et3N is described (Scheme 1).
neo‐Clerodane Diterpenoids from the Aerial Part of Scutellaria barbata
Authors: Lee Hanna , Hee Shim Sang
Published: April 2011

Three new neo‐clerodane diterpenoids, barbatellarines C–E (1–3), were isolated from the CHCl3‐soluble fraction of the aerial part of Scutellaria barbata. Their chemical structures were elucidated by detailed analysis of NMR and MS data. Compounds 1 and 2 were C(13) epimers, which was confirmed by an NOE difference experiment and the NOESY spectrum. The relative configuration was determined on the basis of the 1H‐NMR J‐value and NOE data, while the absolute configuration of the previously isolated analogue, barbatellarine B (4), as a representative member of the group, was assigned by CD analysis.
Dammarane Triterpenes from Gardenia aubryiVieill.
Authors: Grougnet Raphaël , Magiatis Prokopios , Mitaku Sofia , Skaltsounis Alexios‐Leandros , Cabalion Pierre , Tillequin François , Michel Sylvie
Published: April 2011

Three new dammarane triterpenoids, gardaubryones A–C (1–3), were isolated from the gum collected on the aerial parts of Gardenia aubryi Vieill., together with the known compounds hydroxydammarenone II (4), ocotillone (5), cabraleone, and hollongdione. The structures of the novel compounds were established on the basis of mass spectrometry, NMR experiments, and chemical‐correlation reactions.
Identifying step changes in single streamflow and evaporation records due to forest cover change
Authors: Chappell Nick A. , Tych Wlodek
Published: April 2011

Techniques that identify forestry‐induced changes to streamflow or evaporation are needed to assess available water resources. Equally, there is a growing appreciation that climate cycles may be having a profound impact on the land‐surface hydrology. The ability to see forestry‐induced change above the effects of climate dynamics, therefore, becomes a critical issue. Paired‐catchment analyses have proved very valuable in identifying change, but cannot quantify the relative impacts of climate and land‐cover change, and data from adjacent reference basins are not always available. Within this study, we examined whether step changes within single time‐series of streamflow or evaporation (P‐Q) could be identified without reference to those of a control catchment. The UC‐DHR method was used for this analysis, and included a special routine to allow a known change‐point (e.g. start of logging) to be specified or alternatively identified by the model. Data from three experimental catchments important for their seminal forestry impact studies were selected for the analyses.

The study demonstrated that clear‐cutting 29% of the Hore catchment and 40% selective felling of the Berembun basin produced a step change in the discharge trend that was clearly observable above the climate‐related dynamics and uncertainty. In contrast, step changes in P‐Q following the same selective felling event or following 22% afforestation of the Upper Hodder basin were not larger than the uncertainty bands or magnitude of the inter‐annual cycles produced by the climate dynamics, respectively. This demonstrates that while step changes can be observed in single hydrological time‐series, errors within the observations can sometimes mask the identification of change. This masking of change is also possible where the longer‐term cyclical behaviour in Q or P‐Q from natural climate dynamics is large, while the spatial extent of forestry change is small. Copyright © 2011 John Wiley & Sons, Ltd.