bluuebunny/crossref_metadata_2025 huggingface dataset:
DFT Study for a Series of Less‐Symmetrical Crown Ethers and Their Complexes with Alkali Metal Cations
Authors: Miao Yuan , Wang Xueye , Jin Xin , Yi Ling , Ren Cuihuan
Published: November 2010

A series of ring‐contracted (14‐crown‐5, 17‐crown‐6) and ring‐enlarged (16‐crown‐5, 17‐crown‐5, 19‐crown‐6, 20‐crown‐6) crown ethers and their complexes with alkali‐metal cations Na+ and K+ had been explored using density functional theory (DFT) at B3LYP/6‐31G* level in order to reveal the effects of the methylene‐chain length in a crown ether. The nucleophilicity of all crown ethers had been investigated by the Fukui functions. The quantum chemistry parameters, such as the energy gap (ΔE), the highest occupied molecular orbital energy (EHOMO) and the lowest unoccupied molecular orbital energy (ELUMO) for less‐symmetrical crown ethers and symmetrical frameworks (15‐crown‐5, 18‐crown‐6) had been calculated. In addition, the thermodynamic energies of complexation reactions had also been studied. The results of the DFT calculations show that the methylene‐chain length plays an important role in determining the structure characters of the crown ethers and also strongly influences the properties of the ethers. Some of the calculated results are in a good agreement with the experimental values.
Convolutive Cyclic Voltammetry, Chronoamperometry and Chronopotentiometry Studies of C6Me6‐isocloso‐ruthenaborane Complex in Non‐aqueous Medium at a Glassy Carbon Electrode
Authors: Ghoneim M. Mohamed , El‐Hallag S. Ibrahim
Published: November 2010

Electroreduction of the C6Me6‐isocloso‐ruthenaborane complex {(C6Me6)‐isocloso‐1‐RuB10H10} has been investigated using cyclic voltammetry, convolutive voltammetry, chronoamperometry and chronopotentiometry techniques at a glassy carbon electrode in 0.1 mol·L−1 tetrabutyl ammonium perchlorate dissolved in methylene chloride. The investigated complex has been reduced via the consumption of two sequential electrons leading to the formation of monoanion and dianion, respectively. The electrode reaction pathway and the electrochemical parameters of the investigated system were determined. The extracted electrochemical parameters were verified via digital simulation treatments. Diffusion coefficient and heterogeneous electron transfer kinetics of the {(C6Me6)‐isocloso‐1‐RuB10H10} complex at low temperature were studied and discussed.
Formation of Left‐handed Double Twisted Silica Nanoribbons
Authors: Chen Yuxia , Wang Sibing , Liu Xiaojuan , Li Yi , Li Baozong , Yang Yonggang
Published: November 2010

Left‐handed double twisted silica nanoribbons were prepared through a sol‐gel transcription approach in the mixtures of ethanol and water. The self‐assemblies of a chiral low‐molecular‐weight amphiphile served as the templates. The samples were characterized using X‐ray diffraction, transmission electron microscope and scanning electron microscope. These double twisted silica nanoribbons were several micrometers in length, 50 to 70 nm in wideness, about 15 nm in thickness. The silica nanoribbons can be prepared in a large scale.
Synthesis of Hollow‐flower‐ball‐like Cd4(OH)5Cl3 Using Microwave Irradiation Method
Authors: Peng Yin , Liu Shuhua , Yang Zihui
Published: November 2010

Novel mesoporous hollow‐flower‐ball‐like Cd4Cl3(OH)5 was selectively synthesized using microwave‐irradiation process. The structure of the resultant Cd4Cl3(OH)5 was characterized by scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and low temperature nitrogen sorption isotherms. The concentration of the reagents and the reaction time affect the formation of this hollow‐flower‐ball‐like structure of this complex. The formation of this interesting structure may be attributed to the self‐assembly of smaller inorganic building blocks during the crystallization process of Cd4(OH)5Cl3 crystals. The photocatalytic activity of as‐prepared Cd4(OH)5Cl3 was evaluated by the degradation of salicylic acid and 4‐chlorophenol in water under UV‐irradiation.
A New Sensor for Simultaneous Determination of Tyrosine and Dopamine Using Iron(III) Doped Zeolite Modified Carbon Paste Electrode
Authors: Babaei Ali , Zendehdel Mojgan , Khalilzadeh Balal , Abnosi Mohammad
Published: November 2010

A new chemically modified electrode is constructed based on iron(III) doped zeolite modified carbon paste electrode (Fe3+Y/ZMCPE). The new sensor could be used for the simultaneous determination of the biologically important compounds dopamine (DA) and tyrosine (Tyr). The measurements are carried out using differential pulse voltammetric (DPV) method. The prepared modified electrode shows voltammetric responses of high sensitivity, selectivity and stability for DA and Tyr under optimal conditions, which makes it a suitable sensor for simultaneous trace detection of DA and Tyr in solution. Application of the DPV method demonstrates that in the Briton Robinson buffer solutions (pH=5) containing 50 µmol/L Tyr, there is a linear relationship between the oxidation peaks and the concentrations of DA over the range of 0.1–200 µmol/L, with a detection limit of 0.05 µmol/L (S/N=3). For Tyr a linear correlation between oxidation peak current and concentration of Tyr over the range of 0.5–200 µmol/L (containing 50 µmol/L DA), with a detection limit of 0.08 µmol/L is obtained. The analytical performances of this sensor are evaluated for the detection of DA and Tyr in human serum and a medicine.
Study on Production of Amino Acids from Bean Dregs by Hydrolysis in Sub‐critical Water
Authors: Zhu Guangyong , Zhu Xian , Fan Qi , Liu Xiaolei , Shen Yijing , Jiang Junhui
Published: November 2010

This study investigated the production of value‐added amino acids from bean dregs by hydrolysis in subcritical water. It was investigated that the effect of reaction temperature, reaction time and CO2 on amino acid concentration in the hydrolysates of bean dregs. The product of amino acid was determined by Amino Acid Analyzer. The results show that a variety of amino acids are produced. The concentrations of arginine, lysine and alanine were relatively high in the hydrolysate. Temperature and time have a great influence on the hydrolysis reaction. The effects of reaction temperature and time on concentration of different amino acids vary. The addition of carbon dioxide led to an increase in amino acid yield due to the acceleration of acid hydrolyzed catalysis steps. The highest yield of total amino acids is 22% (0.22 g/g of dry bean dregs) at 330°C and 30 min. This method may provide a practical and economical solution for the disposal of bean dregs wastes.
Highly Selective Aldol Condensation Using Amine‐functionalized SiO2‐Al2O3 Mixed‐oxide under Solvent‐free Condition
Authors: Abbaspourrad Alireza , Javad Kalbasi Roozbeh , Zamani Farzad
Published: November 2010

A series of amine catalysts supported on mesoporous molecular sieves SiO2/Al2O3 with trimethoxysilylpropylamine [(CH3O)3Si(CH2)3NH2] loading varying from 3 mmol to 6 mmol were synthesized by impregnation method. The aldol condensation of various aromatic aldehydes and 1‐heptanal was used to test the acid‐base cooperativity of amine‐functionalized SiO2/Al2O3. The effects of solvent, reaction temperature, benzaldehyde to 1‐heptanal molar ratio, different supports (SiO2, Al2O3 and SiO2‐Al2O3), catalyst amount and recyclability of the catalyst were investigated. Sample containing 5 mmol amine loaded showed highest benzaldehyde conversion (100%) and selectivity (97%) for jasminaldehyde.
Increased IL‐17A secretion in response to Candida albicans in autoimmune polyendocrine syndrome type 1 and its animal model
Authors: Ahlgren Kerstin M. , Moretti Silvia , Lundgren Brita Ardesjö , Karlsson Iulia , Åhlin Erik , Norling Anna , Hallgren Åsa , Perheentupa Jaakko , Gustafsson Jan , Rorsman Fredrik , Crewther Pauline E. , Rönnelid Johan , Bensing Sophie , Scott Hamish S. , Kämpe Olle , Romani Luigina , Lobell Anna
Published: November 2010

Autoimmune polyendocrine syndrome type 1 (APS‐1) is a multiorgan autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis, hypoparathyroidism and adrenal failure are hallmarks of the disease. The critical mechanisms causing chronic mucocutaneous candidiasis in APS‐1 patients have not been identified although autoantibodies to cytokines are implicated in the pathogenesis. To investigate whether the Th reactivity to Candida albicans (C. albicans) and other stimuli was altered, we isolated PBMC from APS‐1 patients and matched healthy controls. The Th17 pathway was upregulated in response to C. albicans in APS‐1 patients, whereas the IL‐22 secretion was reduced. Autoantibodies against IL‐22, IL‐17A and IL‐17F were detected in sera from APS‐1 patients by immunoprecipitation. In addition, Aire‐deficient (Aire0/0) mice were much more susceptible than Aire+/+ mice to mucosal candidiasis and C. albicans‐induced Th17‐ and Th1‐cell responses were increased in Aire0/0 mice. Thus an excessive IL‐17A reactivity towards C. albicans was observed in APS‐1 patients and Aire0/0 mice.
Shortened Carbon Nanotubes as Enhanced Support for High‐performance Platinum Catalysts
Authors: Wu Y.‐N. , Liao S.‐J. , Su H.‐N. , Dang D. , Liu B.
Published: November 2010

Carbon nanotubes (CNTs) were shortened from 5 to 15 μm to ca. 200 nm using ball milling with ethanol as the milling aid agent, and a platinum catalyst with these shortened carbon nanotubes (SCNTs) as the support was prepared by a high‐pressure colloidal method. It was found that this catalyst with SCNTs showed much higher activity than a platinum catalyst with normal CNTs as support; for methanol anodic oxidation, the activity of the Pt/SCNTs was 50% higher than that of the Pt/CNTs, and the Pt/SCNTs also showed higher activity for the cathodic reduction of oxygen. The Pt/SCNTs were characterised by X‐ray diffraction scanning and transmission electron microscropy. It is suggested that the significant performance enhancement when SCNTs are used as support might result from the generation of new surfaces and defects, the opening of closed nanotubes in the process of milling, higher platinum dispersion on the shortened nanotubes and the interaction of platinum nanoparticles with the SCNTs.
Studies of the growth, evolution, and self‐aggregation of β‐amyloid fibrils using tapping‐mode atomic force microscopy
Authors: Serem Wilson K. , Bett Cyrus K. , Ngunjiri Johnpeter N. , Garno Jayne C.
Published: November 2010

Amyloid peptide (Aβ) is the major protein component of plaques found in Alzheimer's disease, and the aggregation of Aβ into oligomeric and fibrillic assemblies has been shown to be an early event of the disease pathway. Visualization of the progressive evolution of nanoscale changes in the morphology of Aβ oligomeric assemblies and amyloid fibrils has been accomplished ex situ using atomic force microscopy (AFM) in ambient conditions. In this report, the size and the shape of amyloid β1‐40fibrils, as well as the secondary organization into aggregate structures were monitored at different intervals over a period of 5 months. Characterizations with tapping‐mode AFM serve to minimize the strong adhesive forces between the probe and the sample to prevent damage or displacement of fragile fibrils. The early stages of Aβ growth showed a predominance of spherical seed structures, oligomeric assemblies, and protofibrils; however the size and density of fibrils progressively increased with time. Within a few days of incubation, linear assemblies and fibrils became apparent. Over extended time scales of up to 5 months, the fibrils formed dense ensembles spanning lengths of several microns, which exhibit interesting changes due to self‐organization of the fibrils into bundles or tangles. Detailed characterization of the Aβ assembly process at the nanoscale will help elucidate the role of Aβ in the pathology of Alzheimer's disease. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Extraction and isolation of catechins from tea
Authors: Vuong Quan V. , Golding John B. , Nguyen Minh , Roach Paul D.
Published: November 2010

Tea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf‐life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.
In vivo evaluation and proof of radiofrequency safety of a novel diagnostic MR‐electrophysiology catheter
Authors: Weiss Steffen , Wirtz Daniel , David Bernd , Krueger Sascha , Lips Oliver , Caulfield Dennis , Pedersen Steen Fjord , Bostock Julian , Razavi Reza , Schaeffter Tobias
Published: November 2010

An MR‐electrophysiology (EP) catheter is presented that provides full diagnostic EP functionality and a high level of radiofrequency safety achieved by custom‐designed transmission lines. Highly resistive wires transmit intracardiac electrograms and currents for intracardiac pacing. A transformer cable transmits the localization signal of a tip coil. Specific absorption rate simulations and temperature measurements at 1.5 T demonstrate that a wire resistance > 3 kΩ/m limits dielectric heating to a physiologically irrelevant level. Additional wires do not increase tip specific absorption rate significantly, which is important because some clinical catheters require up to 20 electrodes. It is further demonstrated that radiofrequency‐induced and pacing‐induced resistive heating of the wires is negligible under clinical conditions. The MR‐EP catheters provided uncompromised recording of electrograms and cardiac pacing in combination with a standard EP recorder in MR‐guided in vivo EP studies, and the tip coil enabled fast and robust catheter localization. In vivo temperature measurements during such a study did not detect any device‐related heating, which confirms the high level of safety of the catheter, whereas unacceptable heating was found with a standard EP catheter. The presented concept for the first time enables catheters with full diagnostic EP functionality and active tracking and at the same time a sufficient level of radiofrequency safety for MRI without specific absorption rate‐related limitations. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Fiber‐type dependence of stretch‐induced force enhancement in rat skeletal muscle
Authors: Ramsey Kathryn A. , Bakker Anthony J. , Pinniger Gavin J.
Published: November 2010

When an active muscle is stretched, the force increases due to strain of contractile and noncontractile proteins. We examined this force enhancement in rat extensor digitorum longus (EDL) and soleus muscles, which differ in their composition of these proteins, and their susceptibility to damage. Small stretches were applied at different velocities during isometric contractions from which we quantified the velocity‐dependent contractile and velocity‐independent noncontractile contributions to force enhancement. Whereas the contractile contribution was significantly greater in soleus than EDL, the noncontractile force enhancement was significantly greater in EDL than soleus, and increased ≈6‐fold after damaging eccentric contractions. The increased contractile stiffness may be functionally beneficial in slow muscle, as resistance to lengthening is fundamental to maintaining posture. Following stretch‐induced muscle damage this capacity is compromised, leading to increased strain of noncontractile proteins that may facilitate the activation of signaling pathways involved in muscle adaptation to injury. Muscle Nerve 42: 769–777, 2010
Survey of MicroRNA expression in pediatric brain tumors
Authors: Birks Diane K. , Barton Valerie N. , Donson Andrew M. , Handler Michael H. , Vibhakar Rajeev , Foreman Nicholas K.
Published: November 2010

Background

A better understanding of pediatric brain tumor biology is needed to assist in the development of less toxic therapies and to provide better markers for disease stratification. MicroRNAs (miRNA) may play a significant role in brain tumor biology. The present study provides an initial survey of miRNA expression in pediatric central nervous system (CNS) malignancies including atypical teratoid/rhabdoid tumor, ependymoma, glioblastoma, medulloblastoma, and pilocytic astrocytoma.

Procedure

MicroRNA expression in pediatric brain tumors and normal tissue controls was examined by microarray. Three aberrantly expressed miRNAs were further studied in a larger cohort by quantitative real‐time PCR (qRT‐PCR).

Results

MicroRNA‐129, miR‐142‐5p, and miR‐25 were differentially expressed in every pediatric brain tumor type compared to normal tissue controls as measured by microarray. When further examined by qRT‐PCR, these miRNAs demonstrated differential expression that significantly correlated with the microarray findings. Distinctive miRNA expression profiles were also observed in the different pediatric brain tumor types.

Conclusions

MicroRNAs are differentially expressed between pediatric CNS neoplasms and normal tissue suggesting that they may play a significant role in oncogenesis. A greater understanding of aberrant miRNA expression in pediatric brain tumors may aid in the development of novel therapies. The characterization of tumor‐specific miRNA signatures may aid in the discovery of biomarkers with diagnostic or prognostic utility. Pediatr Blood Cancer 2011;56:211–216. © 2010 Wiley‐Liss, Inc.
Investigation of stabilizer‐free dispersion polymerization process of styrene and maleic anhydride copolymer microspheres
Authors: Liang Pengzong , Meng Zhun , Jiang Zhanglin , Nie Jun , He Yong
Published: November 2010

The copolymer microspheres of styrene (St) and maleic anhydride (MA) were synthesized by stabilizer‐free dispersion polymerization, and the polymerization process was explored in detail. The results showed that the homopolymerization of St formed in initial polymerization period served as stabilizer, and reaction solvent of closer solubility parameter would benefit the stabilizer‐free dispersion polymerization. In addition, some principal factors affecting the microspheres size, such as reaction time, reaction temperature, monomer concentration, molar feed ratio, reaction media, and cosolvent, were investigated as well. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis, characterization, and star polymer assembly of boronic acid end‐functionalized polycaprolactone
Authors: Korich Andrew L. , Walker Amanda R. , Hincke Christopher , Stevens Caitlin , Iovine Peter M.
Published: November 2010

Boronic acid end‐functionalized polycaprolactone (PCL) polymers were synthesized by ring‐opening polymerization using a pinacol boronate ester‐containing (Bpin) initiator. The polymerization provides access to boron‐terminated polymers (i.e. Bpin‐PCL‐OH) with narrow molecular weight distributions (PDI = 1.09). Postsynthetic manipulation of the polymer's terminal hydroxyl group by copper‐catalyzed azide‐alkyne cycloaddition chemistry provides a series of bis end‐functionalized polymers with significant structural diversity at the termini. Deprotection of the boronate ester end group was accomplished with an acidic solid phase DOWEX resin. The boronate ester deprotection methodology does not result in hydrolysis of the polymeric backbone. The boronic acid‐tipped polymers were converted into star polymer assemblies using thermal dehydration and ligand‐facilitated trimerization. Thermal dehydration of (HO)2B‐PCL‐OAc to the corresponding boroxine‐based star polymer assembly was inefficient and lead to degradation products. Ligand‐facilitated trimerization using either pyridine or 7‐azaindole as the Lewis base was efficient and mild. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Solid‐state thermal stability and degradation of a family of poly(N‐isopropylacrylamide‐co‐hydroxymethylacrylamide) copolymers
Authors: Saeed Abdirahman , Georget Dominique M. R. , Mayes Andrew G.
Published: November 2010

There is widespread interest in responsive polymers that show cloud point behavior, but little attention is paid to their solid state thermal properties. To manufacture products based on such polymers, it may be necessary to subject them to high temperatures; hence, it is important to investigate their thermal behavior. In this study, we characterized a family of poly(N‐isopropylacrylamide‐co‐hydroxymethylacrylamide) copolymers. Although poly(N‐isopropylacrylamide) shows very high thermal stability (up to 360 °C), introduction of hydroxy side chains leads to a significant reduction in stability and new degradation processes become apparent. Thermogravimetric analysis and fourier transform infrared spectroscopy (FT‐IR) indicate that the first degradation process involves a chemical dehydration step (110–240 °C), supported by the nonreversing heat flow response in modulated temperature differential scanning calorimetry. Water loss scales with the fraction of hydroxy monomer in the copolymer. Glass transition temperatures (Tg) are higher than the temperatures causing dehydration; hence, these values relate to newly‐formed copolymer structures produced by controlled heating under nitrogen. Fourier transform‐Raman (FT‐Raman) spectra suggest that this transition involves imine formation. The Tg increases as the fraction of hydroxy groups in the original copolymer increases. Further heating leads to degradation and mass loss, and more complex changes in the FT‐IR spectra, consistent with formation of unsaturated species. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Size and morphology controllable core cross‐linked self‐aggregates from poly(ethylene glycol‐b‐succinimide) copolymers
Authors: Park Chan Woo , Lee Hyun Jin , Yang Hee‐man , Woo Min‐ah , Park Hyun gyu , Kim Jong‐Duk
Published: November 2010

We developed a simple route to prepare stabilized micelles and nanovesicles in aqueous solutions. A hydrophobic poly(succinimide) (PSI) was conjugated with the hydrophilic poly(ethylene glycol) (PEG) as a new type of cross‐linkable unit. Spherical aggregates were formed when dissolving the amphiphilic PEG682‐b‐PSI130 copolymer in aqueous solutions directly, and polymer nanovesicles were prepared by a precipitation‐dialysis method using PEG455‐b‐PSI130 copolymer. Bifunctional primary amine was added to the micelle or nanovesicle solutions to prepare cross‐linked structures via aminolysis reaction of the succinimide units. The degree of cross‐linking was controlled by adjusting the molar ratio of the cross‐linker to the succinimide units. Increasing the degree of cross‐linking leads to the compaction of the micelle core thus reduced diameter. The cross‐linked polymer micelles or nanovesicles maintained their morphology in extremely diluted solutions because of their structural stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Another look at the degree‐Kirchhoff index
Authors: Palacios José Luis , Renom José Miguel
Published: November 2010

Let G be an arbitrary graph with vertex set {1,2, …,N} and degrees di ≤ D, for fixed D and all i, then for the index R′(G) = ∑i < jdidjRij we show that

We also show that the minimum of R′(G) over all N‐vertex graphs is attained for the star graph and its value is 2N2 − 5N + 3. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Electronic structure, chemical bonding, and oxidation numbers of first‐row transition metals in [MePIm2] complexes and their cations
Authors: Mitin Alexander V. , Kubicki James D. , Merz Kenneth M.
Published: November 2010

The qualitative structures of the upper one‐electron energy levels of imidazole‐coordinated first‐row transition metal porphyrin [MePIm2] complexes established in the present study have shown that the second oxidation number of the first‐row transition metals in the neutral complexes do not change in their cations and double cations. It was found that occupied orbitals of the density functional theory method obtained with B3LYP functional are not correctly ordered. Therefore, they cannot be used in investigations of the orbital structure of the upper molecular orbitals. A qualitative analysis of density functional theory method wave functions in terms of Mulliken and natural charges of atoms, together with an analysis of electrostatic potentials of the neutral [MePIm2] complex, its single and double cations, demonstrates that the highest occupied orbitals of these complexes are mainly formed by atomic orbitals of the porphyrin ring atoms. Therefore, transition metal atoms are not active in chemical reactions with these complexes unless the 3d electrons of transition metal atoms are excited, for example by light. A mechanism of an electron transfer reaction that occurs between a heme cytochrome and Fe‐oxide mineral surface is discussed in the light of the obtained results. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Kullback–Leibler Information and Its Applications in Multi-Dimensional Adaptive Testing
Authors: Wang Chun , Chang Hua-Hua , Boughton Keith A.
Published: November 2010

This paper first discusses the relationship between Kullback–Leibler information (KL) and Fisher information in the context of multi-dimensional item response theory and is further interpreted for the two-dimensional case, from a geometric perspective. This explication should allow for a better understanding of the various item selection methods in multi-dimensional adaptive tests (MAT) which are based on these two information measures. The KL information index (KI) method is then discussed and two theorems are derived to quantify the relationship between KI and item parameters. Due to the fact that most of the existing item selection algorithms for MAT bear severe computational complexity, which substantially lowers the applicability of MAT, two versions of simplified KL index (SKI), built from the analytical results, are proposed to mimic the behavior of KI, while reducing the overall computational intensity.
Classification of Turkish Extra Virgin Olive Oils by a SAW Detector Electronic Nose
Authors: Kadiroğlu Pınar , Korel Figen , Tokatlı Figen
Published: November 2010

An electronic nose (e‐nose), in combination with chemometrics, has been used to classify the cultivar, harvest year, and geographical origin of economically important Turkish extra virgin olive oils. The aroma fingerprints of the eight different olive oil samples [Memecik (M), Erkence (E), Gemlik (G), Ayvalık (A), Domat (D), Nizip (N), Gemlik–Edremit (GE), Ayvalık–Edremit (AE)] were obtained using an e‐nose consisting a surface acoustic wave detector. Data were analyzed by principal component analysis (PCA) and discriminant function analysis (DFA). Classification of cultivars using PCA revealed that A class model was correctly discriminated from N in two harvest years. The DFA classified 100 and 97% of the samples correctly according to the cultivar in the 1st and 2nd harvest years, respectively. Successful separation among the harvest years and geographical origins were obtained. Sensory analyses were performed for determining the differences in the geographical origin of the olive oils and the preferences of the panelists. The panelists could not detect the differences among olive oils from two different regions. The cultivar, harvest year, and geographical origin of extra virgin olive oils could be discriminated successfully by the e‐nose.
Cryptorchidie: influence sur la fertilité de l’âge au moment de l’orchidopexie, du siège et de la taille du testicule et de l’existence d’anomalies épididymaires
Authors: Jallouli M. , Mefteh S. , Rebai T. , Mhiri R.
Published: November 2010

Malgré le traitement chirurgical, la cryptorchidie reste la cause la plus fréquente de stérilité. À travers une revue de la littérature, les auteurs relatent les données actuelles concernant l’influence de l’âge au moment de l’orchidopexie, de la taille du testicule, du siège du testicule et de l’existence d’une indépendance épididymotesticulaire sur la fertilité ultérieure.
The quality of life and health utility burden of recurrent respiratory papillomatosis in children
Authors: Chadha Neil K. , Allegro Jennifer , Barton Michelle , Hawkes Michael , Harlock Hayley , Campisi Paolo
Published: November 2010

OBJECTIVE

In this study we 1) measured the impact of juvenile‐onset recurrent respiratory papillomatosis on health‐related quality of life, voice‐related quality of life, and family psychosocial well‐being; and 2) compared these different measures, exploring their intercorrelation and their correlation with clinical disease severity.

STUDY DESIGN

Cross‐sectional qualitative study.

SETTING

Tertiary academic pediatric hospital.

SUBJECTS AND METHODS

Twenty consecutive children with active juvenile‐onset recurrent respiratory papillomatosis (JoRRP) were included. Standardized interviews were performed on parents and children with the use of four validated tools: the Health Utilities Index version 3; the Pediatric Voice‐Related Quality of Life survey; the Impact on Family Scale; and a visual analogue health preference measure. Clinical disease severity and demographic data also were collected.

RESULTS

Subjects (13 male, 7 female) had a median age of 9.2 years, median age of JoRRP onset of 3.8 years, and averaged four procedures per year of disease. Mean health utility was 0.76 (95% confidence interval 0.68–0.84) on a scale of 0 (death) to 1 (perfect health). Marked impact on voice‐related quality of life and family psychosocial health also was identified. Health burden correlated poorly with existing methods of severity scoring.

CONCLUSION

This is the first study to use validated measures of health utility, voice‐related quality of life, and psychosocial impact. This information has public health implications, providing essential parameters for accurate modeling studies and cost‐utility analysis of future interventions, including different human papilloma virus vaccination strategies.
Induced endolymphatic flow from the endolymphatic sac to the cochlea in Ménière's disease
Authors: Mandalà Marco , Colletti Liliana , Carner Marco , Cerini Roberto , Barillari Marco , Mucelli Roberto Pozzi , Colletti Vittorio
Published: November 2010

OBJECTIVE

The aim of the present study was to verify whether drugs injected into the endolymphatic sac (ES) can reach the cochlea and possibly treat inner ear disorders.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center, Otolaryngology Department, University of Verona.

SUBJECTS AND METHODS

Patients with Ménière's disease (MD) who were candidates for ES decompression were selected. Nineteen subjects received dexamethasone (DEX) via injection into the ES. To objectively define whether substances administered into the ES could reach the cochlea, we added gadolinium (GD) in three patients. All subjects had intraoperative electrocorticogram recordings and an audiologic follow‐up. The three subjects who underwent injection of the DEX‐GD solution were followed‐up with magnetic resonance imaging. The audio‐logical data are presented during a follow‐up period of 12 months.

RESULTS

Intraoperative electrocochleography recordings revealed no changes in two patients and summating potentials and compound action potential latency and wave‐form modifications in all the other subjects. GD distribution was observed from 48 hours to one week after ES injection into the cochlea of the three subjects injected with DEX‐GD. GD‐related enhancement of inner ear structures lasted more than two weeks in all subjects. Pure tone average results showed hearing improvement of at least 20 dB HL in 42 percent of patients (8 of 19) at the 12‐month follow‐up. Statistically significant differences emerged between the mean pure tone average of the ES procedure subjects at one and 12 months after surgery (P = 0.0096).

CONCLUSION

This novel approach might reveal new prospects for treating viral, metabolic, autoimmune, and genetic disorders of the cochlea.
A speleothem record of Holocene climate variability from southwestern Mexico
Authors: Bernal Juan Pablo , Lachniet Matthew , McCulloch Malcolm , Mortimer Graham , Morales Pedro , Cienfuegos Edith
Published: November 2010

A paleoclimate reconstruction for the Holocene based upon variations of δ18O in a U–Th dated stalagmite from southwestern Mexico is presented. Our results indicate that the arrival of moisture to the area has been strongly linked to the input of glacial meltwaters into the North Atlantic throughout the Holocene. The record also suggests a complex interplay between Caribbean and Pacific moisture sources, modulated by the North Atlantic SST and the position of the ITCZ, where Pacific moisture becomes increasingly more influential through ENSO since ~ 4.3 ka. The interruption of stalagmite growth during the largest climatic anomalies of the Holocene (10.3 and 8.2 ka) is evidenced by the presence of hiatuses, which suggest a severe disruption in the arrival of moisture to the area. The δ18O record presented here has important implications for understanding the evolution of the North American Monsoon and climate in southwestern Mexico, as it represents one of the most detailed archives of climate variability for the area spanning most of the Holocene.
Unsteady aerodynamics of dragonfly using a simple wing–wing model from the perspective of a force decomposition
Authors: HSIEH CHENG-TA , KUNG CHUN-FEI , CHANG CHIEN C. , CHU CHIN-CHOU
Published: November 2010

Insects perform their multitude of flight skills at frequencies of tens to hundreds of Hertz, and the aerodynamics of these skills are fundamentally unsteady. Intuitively, unsteadiness may come from unsteady wing motion, unsteady surface vorticity or vorticity being shed into the rear and front wakes. In this study, we propose to investigate the aerodynamics of dragonfly using a simplified wing–wing model from the perspective of many-body force decomposition and the associated force elements. Insect flight usually operates at Reynolds numbers of the order of several hundreds, at which the surface vorticity is shown to play a substantial role. There are important cases where the added mass effect is non-negligible. Nevertheless, the major contribution to the forces comes from the vorticity within the flow. This study focused on the effects of mutual interactions due to phase differences between the fore- and hindwings in the translational as well as rotational motions. It is well known that the dynamic stall vortex is an important mechanism for an unsteady wing to gain lift. In analysing the life cycles of lift and thrust elements, we also associate some high lift and thrust with the mechanisms identified as ‘riding on’ lift elements, ‘driven by’ thrust elements and ‘sucked by’ thrust elements, by which a wing makes use of a shed or fused vortex below, in front of, and behind it, respectively. In addition, a shear layer attaching to each wing may also provide significant thrust elements.
David Crighton FRS
Authors: WILLIAMS J. E. FFOWCS
Published: November 2010

Apart from being extremely clever, David Crighton was a very nice person. He must have been well brought up and made his family very proud of him (see figures 1 and 2).
Youth music and politics in post-war Sierra Leone
Authors: Shepler Susan
Published: November 2010

The brutal, eleven-year long civil war in Sierra Leone has been understood by many scholarly observers as ‘a crisis of youth’. The national elections of 2007 were notable for an explosion of popular music by young people directly addressing some of the central issues of the election: corruption of the ruling party and lack of opportunities for youth advancement. Though produced by youth and understood locally as youth music, the sounds were inescapable in public transport, markets, and parties. The musical style is a combination of local idioms and West African hip-hop. The lyrics present a young people's moral universe in stark contrast to that of their elders. This paper addresses the themes of these election-focused songs as well as the emerging subaltern youth identity discernible in supposedly less political songs.
Turkey's opening to Africa
Authors: Özkan Mehmet , Akgün Birol
Published: November 2010

As part of on-going multidimensional foreign policy changes in recent years, there has been since 1998 a revival in Turkey's relations with Africa. Initially rather passive, after 2005 this became a massive effort to develop relations with the whole continent. However, Turkey's Africa policy is unique in Turkish foreign policy, since for the first time it is driven and complemented by the activities of civil society organisations in and about Africa. Conceptualisation of Africa in Turkish society has changed dramatically in less than a decade, and the recent Turkey–Africa Cooperation Summit should be seen as part of this trend. Turkey's opening to Africa is not a short-term inclination, but is likely to develop and deepen in coming years.
Spatial variation of the crustal stress field along the Ryukyu‐Taiwan‐Luzon convergent boundary
Authors: Wu Wen‐Nan , Kao Honn , Hsu Shu‐Kun , Lo Chung‐Liang , Chen How‐Wei
Published: November 2010

We applied an improved stress inversion method to a comprehensive data set of earthquake focal mechanisms to depict the pattern of crustal stress along the western convergent boundary of the Philippine Sea plate. Our results indicate that the crustal stress along the Ryukyu fore arc is segmented with boundaries at or near the places of seamount subduction, including the Tokara channel. An extensional stress regime is observed along the entire Ryukyu back arc, implying that back‐arc rifting may have extended northward to Kyushu. A triangular area near the southernmost terminus of the Ryukyu arc is characterized by a unique stress signature. The eastern boundary of this Ryukyu‐Taiwan Stress Transition coincides with the 123°E meridian where the Gagua ridge intercepts the Ryukyu trench; whereas its western boundary agrees remarkably well with the border between the postcollision and waning‐collision domains in northern Taiwan. The Taiwan collision zone is dominated by compression that rotates locally according to the structural configuration of the Lukang Magnetization High (LMH), suggesting that the LMH may be critical in controlling the local stress distribution. The stress signature of the Luzon arc–Taiwan collision reaches as far south as 19.5°N. The tectonic stress along the Manila trench–Luzon fore arc is dominated by a complex regime of extension that cannot be explained by simple plate bending or in‐slab membrane stress. Since this extensional regime is observed only south of ∼22°N, it probably marks the northern limit of the contemporary boundary between the subduction along the Manila trench and the collision in Taiwan.
Remote sensing and inverse transport modeling of the Kasatochi eruption sulfur dioxide cloud
Authors: Kristiansen N. I. , Stohl A. , Prata A. J. , Richter A. , Eckhardt S. , Seibert P. , Hoffmann A. , Ritter C. , Bitar L. , Duck T. J. , Stebel K.
Published: November 2010

An analytical inversion method is used to estimate the vertical profile of sulfur dioxide (SO2) emissions from the major 2008 eruption of Kasatochi Volcano, located on the Aleutian Arc, Alaska. The method uses satellite‐observed total SO2 columns from the Global Ozone Monitoring Experiment‐2 (GOME‐2), Ozone Monitoring Instrument (OMI), and Atmospheric InfraRed Sounder (AIRS) during the first 2 days after the eruption, and an atmospheric transport model, FLEXPART, to calculate the vertical emission profile. The inversion yields an emission profile with two large emission maxima near 7 km above sea level (asl) and around 12 km asl, with smaller emissions up to 20 km. The total mass of SO2 injected into the atmosphere by the eruption is estimated to 1.7 Tg, with ∼1 Tg reaching the stratosphere (above 10 km asl). The estimated vertical emission profile is robust against changes of the assumed eruption time, meteorological input data, and satellite data used. Using the vertical emission profile, a simulation of the transport extending for 1 month after the eruption is performed. The simulated cloud agrees very well with SO2 columns observed by GOME‐2, OMI, and AIRS until 6 days after the eruption, and the altitudes agree with both Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation measurements and ground‐based lidar observations to within 1 km. The method is computationally very fast. It is therefore suitable for implementation within an operational environment, such as the Volcanic Ash Advisory Centers, to predict the threat posed by volcanic emissions for air traffic.
A link between reduced Barents‐Kara sea ice and cold winter extremes over northern continents
Authors: Petoukhov Vladimir , Semenov Vladimir A.
Published: November 2010

The recent overall Northern Hemisphere warming was accompanied by several severe northern continental winters, as for example, extremely cold winter 2005–2006 in Europe and northern Asia. Here we show that anomalous decrease of wintertime sea ice concentration in the Barents‐Kara (B‐K) seas could bring about extreme cold events like winter 2005–2006. Our simulations with the ECHAM5 general circulation model demonstrate that lower‐troposphere heating over the B‐K seas in the Eastern Arctic caused by the sea ice reduction may result in strong anticyclonic anomaly over the Polar Ocean and anomalous easterly advection over northern continents. This causes a continental‐scale winter cooling reaching −1.5°C, with more than 3 times increased probability of cold winter extremes over large areas including Europe. Our results imply that several recent severe winters do not conflict the global warming picture but rather supplement it, being in qualitative agreement with the simulated large‐scale atmospheric circulation realignment. Furthermore, our results suggest that high‐latitude atmospheric circulation response to the B‐K sea ice decrease is highly nonlinear and characterized by transition from anomalous cyclonic circulation to anticyclonic one and then back again to cyclonic type of circulation as the B‐K sea ice concentration gradually reduces from 100% to ice free conditions. We present a conceptual model that may explain the nonlinear local atmospheric response in the B‐K seas region by counter play between convection over the surface heat source and baroclinic effect due to modified temperature gradients in the vicinity of the heating area.
Observations of energetic electrons up to 200 keV associated with a secondary island near the center of an ion diffusion region: A Cluster case study
Authors: Wang Rongsheng , Lu Quanming , Li Xing , Huang Can , Wang Shui
Published: November 2010

An antiparallel reconnection event is recognized in the magnetotail, and a secondary island with a strong core magnetic field is identified near the center of the ion diffusion region. In the island, the electron density peaks in the outer region while the dip is in the core region with a strong core magnetic field. A strong electron beam parallel to the magnetic field, as well as an obvious current antiparallel to the magnetic field with density up to ∼40 nA/m2, is observed in the outer region of the island. This suggests that the strong core magnetic field inside the island is generated by the electron beam and then the antiparallel current in the outer region of the island. The electron density dip in the core region is formed due to the existing strong core field, which expels electrons out of the core region. The electron flat‐top distributions are detected in the ion diffusion region except the core region of the island, and the shoulder energy range of the flat‐top distributions is from 100 eV to 4 keV. An enhancement of the energetic electron flux up to 200 keV is found in the ion diffusion region, and a further increase of energetic electron fluxes is observed inside the island. Waves at the lower hybrid frequency are intensified in the ion diffusion region, while the intensification is strong in the outer region of the island and becomes very weak in the core region.
Composition, uniqueness and variability of the epiphytic bacterial community of the green alga Ulva australis
Authors: Burke Catherine , Thomas Torsten , Lewis Matt , Steinberg Peter , Kjelleberg Staffan
Published: November 2010

Green Ulvacean marine macroalgae are distributed worldwide in coastal tidal and subtidal ecosystems. As for many living surfaces in the marine environment, little is known concerning the epiphytic bacterial biofilm communities that inhabit algal surfaces. This study reports on the largest published libraries of near full-length 16S rRNA genes from a marine algal surface (5293 sequences from six samples) allowing for an in-depth assessment of the diversity and phylogenetic profile of the bacterial community on a green Ulvacean alga. Large 16S rRNA gene libraries of surrounding seawater were also used to determine the uniqueness of this bacterial community. The surface of Ulva australis is dominated by sequences of Alphaproteobacteria and the Bacteroidetes, especially within the Rhodobacteriaceae, Sphingomonadaceae, Flavobacteriaceae and Sapropiraceae families. Seawater libraries were also dominated by Alphaproteobacteria and Bacteroidetes sequences, but were shown to be clearly distinct from U. australis libraries through the clustering of sequences into operational taxonomic units and Bray–Curtis similarity analysis. Almost no similarity was observed between these two environments at the species level, and only minor similarity was observed at levels of sequence clustering representing clades of bacteria within family and genus taxonomic groups. Variability between libraries of U. australis was relatively high, and a consistent sub-population of bacterial species was not detected. The competitive lottery model, originally derived to explain diversity in coral reef fishes, may explain the pattern of colonization of this algal surface.
Effect of temperature on development rate and fecundity of apterous Aphis gossypii Glover (Hom., Aphididae) reared on Gossypium hirsutum L.
Authors: Kersting U. , Satar S. , Uygun N.
Published: November 2010

The developmental time, survival and reproduction of the cotton aphid, Aphis gossypii Glover (Hom., Aphididae), were evaluated on detached cotton leaves at five constant and two alternating temperatures (15, 20, 25, 30, 35, 25/30, and 30/35°C). The developmental periods of the immature stages ranged from 12.0 days at 15°C to 4.5 days at 30°C. A constant temperature of 35°C was lethal to the immature stages of A. gossypii. The lower developmental threshold for the cotton aphid was estimated at 6.2°C and it required 108.9 degree‐days for a first instar to become adult. The average longevity of adult females was reduced from 39.7 days at 15°C to 12.6 days at 30/35°C. The average reproduction rate per female was 51.5 at 25/30°C and 20.9 at 30/35°C. Mean generation time of the population ranged from 10.4 days at 30°C to 24.5 days at 15°C. The largest per capita growth rate (rm = 0.413) occurred at 30°C, the smallest at 15°C (rm = 0.177). It was evident that temperatures over 30°C prolonged development, increased the mortality of the immature stages, shortened adult longevity, and reduced fecundity. The optimal range of temperature for population growth of A. gossypii on cotton was 25/30–30°C.