bluuebunny/crossref_metadata_2025 huggingface dataset:
Le mécanisme de sélection des firmes est-il efficace? Une approche en termes de coût d’opportunité
Authors: Asma Raies , Mohamed Ben Mimoun
Published: July 2012

La littérature récente a toujours attribué au phénomène dit de « sélection naturelle » – selon lequel, seules les firmes les plus efficientes survivent alors que les autres sont éliminées par le jeu de la concurrence – un rôle crucial dans la croissance de l’efficience agrégée. En supposant, dans le cadre d’un modèle théorique que les firmes différent non seulement par leurs niveaux d’efficience mais aussi par leurs valeurs de réservation, nous montrons ici que le rôle du mécanisme de sélection dans la croissance de l’efficience agrégée peut être remis en cause notamment lorsque les sortants sont plutôt les firmes les plus efficientes. Un autre résultat important consiste à montrer, qu’à l’équilibre stationnaire, les firmes efficientes et inefficientes peuvent coexister. Ce faisant, le modèle développé permet de rendre compte de la persistance des firmes inefficientes et de la grande dispersion des niveaux d’efficience constatée dans plusieurs études empiriques.
Just Tell Us What Happened to You: Autobiographical Memory and Seeking Asylum
Authors: Herlihy Jane , Jobson Laura , Turner Stuart
Published: July 2012

When someone flees their country and seeks the protection of another state, they usually have to describe what happened to make them afraid to return. This task requires many psychological processes, a key one being autobiographical memory. Memory for events of a specific time and place in one's personal past is the subject of a huge literature, much of it showing that recall is vulnerable to distortions and biases. We review selected areas of this literature, shedding light on some of the processes at work when someone seeks to be recognised as a refugee—in particular, the effects of emotion, including emotional disorder. We then turn to the differing types of memory styles seen in different cultures. Crucial to this area, we briefly examine the current literature on deception. Finally, we draw on the reviewed literature to present conclusions about the reliance on autobiographical memories in the asylum process. Copyright © 2012 John Wiley & Sons, Ltd.
Osteological Associations With Unique Tooth Development in Manatees (Trichechidae, Sirenia): A Detailed Look at Modern Trichechus and a Review of the Fossil Record
Authors: Beatty Brian Lee , Vitkovski Taisia , Lambert Olivier , Macrini Thomas E.
Published: July 2012

Modern manatees have a unique type of tooth development, continually forming identical new molars in the posterior end of each quadrant of their mouths, and then progressively moving teeth anteriorly, only to reabsorb roots and spit out worn crowns. This process is not only developmentally complex, but requires space in the oral cavity that imposes its own limitations on other uses of that space. To gain a clearer understanding of the anatomical constraints on the evolution of this unique developmental process, we identified the specialized craniodental features in modern Trichechus that permit this specialization using visual observation and CT. Furthermore, to better understand the evolution of these traits, we review the fossil record of trichechids for these traits, including CT analysis of the skull of Miosiren kocki, a possible early member of the family from the Early Miocene of Belgium. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Enriched Environment and White Matter in Aging Brain
Authors: Yang Shu , Lu Wei , Zhou De‐Shan , Tang Yong
Published: July 2012

Normal aging is commonly associated with decreased cognitive functions, which could be conspicuously alleviated by enriched environment (EE) with physical, social, and sensory stimuli, suggesting that aging brain still has intriguing plasticity. Multiple researches have been carried out to explore the structural and the molecular changes in aging brain, which would be considered for evidences that EE regulated brain plasticity. Because there is no significant neuron loss in aging cerebral cortex and the white matter is crucial for cognitive functions, this review focused on the age‐related white matter changes and the effects of EE on aged white matter. Data from our stereology laboratory revealed that age‐related spatial memory declines had more to do with white matter alterations, which were due to marked demyelination and loss of oligodendrocytes in the white matter. We also demonstrated that EE recovered spatial memory impairment and increased white matter volume by promoting marked remyelination in aged brain. This review approached the issue that EE might contribute to normal aging and be beneficial for those suffering from demyelinated diseases. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Iterative sparse matrix–vector multiplication for accelerating the block Wiedemann algorithm over GF(2) on multi‐graphics processing unit systems
Authors: Schmidt Bertil , Aribowo Hans , Dang Hoang‐Vu
Published: July 2012

The block Wiedemann (BW) algorithm is frequently used to solve sparse linear systems over GF(2). Iterative sparse matrix–vector multiplication is the most time‐consuming operation. The necessity to accelerate this step is motivated by the application of BW to very large matrices used in the linear algebra step of the number field sieve (NFS) for integer factorization. In this paper, we derive an efficient CUDA implementation of this operation by using a newly designed hybrid sparse matrix format. This leads to speedups between 4 and 8 on a single graphics processing unit (GPU) for a number of tested NFS matrices compared with an optimized multicore implementation. We further present a GPU cluster implementation of the full BW for NFS matrices. A small‐sized GPU cluster is able to outperform CPU clusters of larger size for large matrices such as the one obtained from the Kilobit special NFS factorization. Copyright © 2012 John Wiley & Sons, Ltd.
Health status of ayahuasca users
Authors: Barbosa Paulo Cesar Ribeiro , Mizumoto Suely , Bogenschutz Michael P. , Strassman Rick J.
Published: July 2012

Ayahuasca is a psychedelic brew originally used for magico‐religious purposes by Amerindian populations of the western Amazon Basin. Throughout the last four decades, the use of ayahuasca spread towards major cities in all regions of Brazil and abroad. This trend has raised concerns that regular use of this N,N‐dimethyltryptamine‐ and harmala‐alkaloid‐containing tea may lead to mental and physical health problems associated typically with drug abuse. To further elucidate the mental and physical health of ayahuasca users, we conducted a literature search in the international medical PubMed database. Inclusion criteria were evaluation of any related effect of ayahuasca use that occurred after the resolution of acute effects of the brew. Fifteen publications were related to emotional, cognitive, and physical health of ayahuasca users. The accumulated data suggest that ayahuasca use is safe and may even be, under certain conditions, beneficial. However, methodological bias of the reviewed studies might have contributed to the preponderance of beneficial effects and to the few adverse effects reported. The data up to now do not appear to allow for definitive conclusions to be drawn on the effects of ayahuasca use on mental and physical health, but some studies point in the direction of beneficial effects. Additional studies are suggested to provide further clarification. Copyright © 2012 John Wiley & Sons, Ltd.
Investigation of emissions from heated essential‐oil‐rich fuels at 200 °C
Authors: Zhao Feng‐Jun , Shu Li‐Fu , Wang Ming‐Yu , Tian Xiao‐Rui
Published: July 2012

Essential oil of fuels is closely linked with the behavior of forest fires, especially high intensity fires and eruptive fires. It is assumed that the potential reason is the large quantities of flammable gases released from essential oil‐rich fuels before pyrolysis in fire environment. However, few studies have been carried out on the hypothesis. The purpose of the present study is to investigate the emissions from essential oil‐rich fuels. The fuels were collected from three coniferous species. In the experiment, needles and twigs were heated in a vacuum oven at 200 °C, and the emissions within 15 min had been sampled using Tenax tubes. Gas chromatography–mass spectrometry served as an analytical instrument. The results showed that the emissions contained high proportion of monoterpenes, such as α‐pinene, camphene, β‐pinene, 3‐carene, and d‐limonene. The monoterpene emissions from heated needles and twigs of Pinus pumila, Larix gmelinii, and Pinus sylvestris were 61.221, 49.606, and 37.853 µg g−1 dry weight (needles), and 211.727, 139.957, and 121.505 µg g−1 dry weight (twigs), respectively. Statistical analyses showed the significant differences not only among species but also between needles and twigs. Copyright © 2012 John Wiley & Sons, Ltd.
Experimental evaluation of flame and flamelet spread over cellulosic materials using the narrow channel apparatus
Authors: Wichman Indrek S. , Olson Sandra L. , Miller Fletcher J. , Tanaya Stefanus A.
Published: July 2012

Originally conceived as an apparatus to study near‐limit flames and their breakup into flamelets and later modified to function as a microgravity simulation apparatus, the narrow channel apparatus serves also as a facility for examining long time flame spread and material flammability in on‐earth (terrestrial) applications. These applications include flame spread in narrow gaps, persistence of flame in heat‐loss environments, and flame‐to‐flamelet front transition. The narrow channel apparatus tests described here measure behavior of the spreading flame and features of the flame‐to‐flamelet transition. Measured quantities include flow, flame and flamelet velocities in normal and inverted tests, flow deceleration and acceleration rates with associated flame or flamelet response, flame‐to‐flamelet transition times, and influences of fuel thickness. The principal goal of this research was to ascertain the capacity of the narrow channel apparatus to produce data for phenomena observed in both (1) simulated microgravity flame spread and (2) terrestrial flame spread in narrow gaps and channels. Copyright © 2012 John Wiley & Sons, Ltd.
In vitrobiodistribution of silver nanoparticles in isolated perfused porcine skin flaps
Authors: Leavens Teresa L. , Monteiro‐Riviere Nancy A. , Inman Alfred O. , Brooks James D. , Oldenburg Steven J. , Riviere Jim E.
Published: July 2012

Nanomaterials increasingly are playing a role in society for uses ranging from biomedicine to microelectronics; however, pharmacokinetic studies, which will be necessary for human health risk assessments, are limited. Currently the most widely used nanoparticle in consumer products is silver (Ag). The objective of the present study was to quantify the local biodistribution of two types of Ag nanoparticles, Ag‐citrate and Ag‐silica, in the isolated perfused porcine skin flap (IPPSF). IPPSFs were perfused for 4 h with 0.84 µg ml–1Ag‐citrate or 0.48 µg ml–1Ag‐silica followed by a 4‐h perfusion with media only during a washout phase. Arterial and venous concentrations of Ag were measured in the media by inductively coupled plasma optical emission spectrometry (ICP‐OES). Venous concentrations of Ag for both types of nanoparticles were best fit with a two compartment model. The normalized volumes of distribution estimated from the noncompartmental analysis of the venous concentrations indicated distribution of Ag greater than the vascular space; however, because total Ag was measured, the extravascular distribution could be attributed to diffusion of Ag ions. The estimated clearance for both types of Ag nanoparticles was 1 ml min–1, which was equal to the flap perfusion rate, indicating no detectable elimination of Ag from the system. Four hours after infusion of the Ag nanoparticles, the recovery of Ag in the venous effluent was 90 ± 5.0% and 87 ± 22 % of the infused Ag for Ag‐citrate and Ag‐silica, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
Corn oil as a vehicle in drug development exerts a dose‐dependent effect on gene expression profiles in rat thymus
Authors: Geng Xing‐Chao , Li Bo , Zhang Liang , Song Ying , Lin Zhi , Zhang Ying‐Qi , Wang Jun‐Zhi
Published: July 2012

The purpose of this study was to investigate the effects of corn oil (CO), which is widely used as a vehicle for water‐insoluble agents in drug development, on the gene expression profiles in rat thymus with microarray technique. Female Wistar rats were administered daily with normal saline (NS) and CO 2, 5 and 10 ml kg−1 per day for 14 days, respectively. Then, the thymus samples of rats were collected for microarray test and histopathology examination. CD4+ and CD8+ lymphocytes in peripheral blood were also numerated to assess the effects on lymphocyte subpopulations. The microarray data showed that the numbers of differentially expressed genes in the 2, 5 and 10 ml kg−1 CO groups were 0, 40 and 458, respectively, compared with the NS control group. The altered genes were mainly associated with immune response, cellular response to organic cyclic substance and regulation of fatty acid β‐oxidation. However, no abnormal changes in thymus weight, CD4+ and CD8+ lymphocytes counts and histopathological examination were observed in the three CO groups. These data showed that 10 ml kg−1 CO, the usually recommended dosing volume as a vehicle in drug safety assessment, caused obvious dysregulated genes in rat thymus. Our study suggests that the appropriate dosing volume of CO gavage as a vehicle for water‐insoluble agents in drug development should be 2 ml kg−1 per day, if agent effects on thymus will be assessed in gene levels. Copyright © 2012 John Wiley & Sons, Ltd.
Predictive model for L‐type channel inhibition: multichannel block in QT prolongation risk assessment
Authors: Wiśniowska Barbara , Mendyk Aleksander , Fijorek Kamil , Glinka Anna , Polak Sebastian
Published: July 2012

Evaluation of the proarrhythmic potential of an investigated compound is now an integral element of the safety profile required for the approval of new drugs. The human ether‐à‐go‐go‐related gene (hERG) channel blocking potency is regarded as a surrogate marker of the proarrhythmic risk at the early stages of the research and development process. However, there is no straight correlation between QT prolongation and TdP occurrence probability, and hERG inhibition potential can be an inadequate predictor of QT prolongation. The L‐type calcium channel plays a pivotal role in cardiomyocytes' physiology. Thus the main aim of this study was to develop a predictive model for drug‐triggered CaL channel inhibition and also the assessment of drug–multichannel interaction effects on the heart rate‐corrected QT interval. The data set, consisting of 123 records describing in vitro experimental settings, measured IC50 values and calculated physico‐chemical properties for 72 various chemicals, was collected. The models were tested in a modified 10‐fold cross‐validation procedure. The generalization ability of the best model was as follows: root mean squared error (RMSE) = 1.10, normalized root mean squared error (NRMSE) = 16.09%. Out of the 10 most important variables, 5 described conditions of the in vitro experiments thus their description and experiment's conditions standardization might be the key to the models better performance. The simulations performed with the ToxComp system showed that the hERG block alone causes concentration‐dependent QT prolongation, whereas when multichannel block is regarded, the effect could be reversed. For that reason, the multichannel interaction of tested compounds should be taken into consideration, in order to make the proarrhythmic risk assessment more reliable. Copyright © 2012 John Wiley & Sons, Ltd.
A preliminary study of presence of resveratrol in skins and pulps of European and Japanese plum cultivars
Authors: Sebastià Natividad , Montoro Alegría , Mañes Jordi , Soriano Jose M
Published: July 2012

BACKGROUND: Resveratrol is a polyphenol with health properties being mainly present in the skins of several foods. However, any study has been carried out to analyze the presence of this stilbene in the plum fruit from the genus Prunus in European and Japanese cultivars.

RESULTS: The analysis of resveratrol from the skin in different cultivars of plums from Spanish markets with liquid chromatography coupled to ultraviolet (LC‐UV) detector with subsequent confirmation by LC‐MS/MS has been demonstrated that contents of this compound in plums ranged from 0.1 to 6.2 µg/g.

CONCLUSIONS: Values of resveratrol in European plum cultivars is higher than in Japanese cultivars. Copyright © 2012 Society of Chemical Industry
Needle trap extraction for GC analysis of formic and acetic acids in aqueous solution
Authors: Lee Xinqing , Huang Daikuan , Lou Dawei , Pawliszyn Janusz
Published: July 2012

Formic and acetic acids are ubiquitous in the environment, food, and most of the natural products. Extraction of the acids from aqueous solution is required for their isotope analysis by the gas chromatography‐isotope ratio mass spectrometry. To this objective, we have previously developed a purge‐and‐trap technique using the dynamic solid‐phase microextraction technology, the NeedlEX. The extraction efficiency, however, remains unexamined. Here, we address this question using the flame ionization detector and isotope ratio mass spectrometer while comparing it with that of the CAR/PDMS fiber. The results show that the NeedlEX is applicable at a wide range of concentration through coordination of purge volume given the minimum amount 3.7 ng and 1.8 ng of formic and acetic, respectively, is extracted. The efficiency of NeedlEX was 6–7 times lower than the fiber at 1000 μg/mL depending on the analyte. It is, however, superior to the latter at 10 μg/mL or less owing to its lower detection limit. The extraction efficiency of both acids is equivalent in molar amount. This is, however, disguised by the different response of the flame ionization detector. The isotope ratio mass spectrometor overcomes this problem but is compromised by relatively large errors. These results are particularly useful for isotopic analysis of carboxylic acids.
Development of magnetic multiwalled carbon nanotubes as solid‐phase extraction technique for the determination of p‐hydroxybenzoates in beverage
Authors: Huang Danni , Fu Chinfai , Li Zhongbo , Deng Chunhui
Published: July 2012

In this work, magnetic multiwalled carbon nanotubes were synthesized through a facile hydrothermal process, and then successfully used as magnetic solid‐phase extraction sorbents for the determination of p‐hydroxybenzoates in beverage. The prepared magnetic multiwalled carbon nanotubes presented both satisfactory superparamagnetism and strong capacity of absorption, with magnetic Fe3O4 beads of 200 nm average diameters decorated at either ends of the tubes. The hybrid nanocomposites showed a high efficiency in the extraction and enrichment of p‐hydroxybenzoates via π–π stacking of targeted molecules onto the polyaromatic composed surface of multiwalled carbon nanotubes, which entitled them promising magnetic solid‐phase extraction sorbents for p‐hydroxybenzoates at trace level from complex drink samples. By using an external magnetic field, p‐hydroxybenzoates adsorbed on magnetic multiwalled carbon nanotubes could be rapidly isolated in only 30 s, and subsequently analyzed by liquid chromatography‐diode array detector after elution with organic solvents. Extraction conditions such as eluting solvent, the amounts of magnetic sorbents added, pH values, adsorption and desorption time were investigated and optimized to achieve the best effect. Method validations including linearity, detection limit, and precision were also studied. The linearities were in the wide range of 0.05–500 μg/mL with correlation coefficients higher than 0.9983 for all p‐hydroxybenzoates. The limits of detection were less than 20 ng/mL. Acceptable RSDs were achieved within 5–8% for all analytes. The results indicated that the proposed method based on magnetic multiwalled carbon nanotubes as magnetic solid‐phase extraction absorbents was rapid, efficient, and convenient for the analysis of the targeted compounds of p‐hydroxybenzoates in beverage sample.
Time‐dependent column performance of cholesterol‐based stationary phases for HPLC by LC characterization and solid‐state NMR spectroscopy
Authors: Yeman Helen , Nicholson Tim M. , Friebolin Volker , Steinhauser Lisa , Matyska Maria T. , Pesek Joseph J. , Albert Klaus
Published: July 2012

Three different cholesterol‐based stationary phases were investigated with respect to their time‐dependent separation behavior. The examined stationary phases differ in the used spacer molecule and the synthesis route and were used under routine laboratory conditions over a period of two years. The chromatographic behavior of the three phases was determined by using a standard reference material in addition to a separation of a steroid mixture. The surface chemistry and the modification of these with the chemically bonded moiety were investigated with nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Through applying different techniques we determined changes in retention and selectivity; solid‐state NMR spectra showed changes in the surface chemistry dependent on the synthesis route. Superior long‐term stability was observed for the undecanoate‐cholesterol (UDC‐Chol) column in terms of hydrophobic retentiveness and selectivity.
Temperature effects on nano‐LC column packing technology
Authors: Leonardis Irene , Capriotti Fabiana , Cappiello Achille , Famiglini Giorgio , Palma Pierangela
Published: July 2012

We investigated the effect of temperature on the packing procedure of nano‐LC columns (up to 50 cm) and on their performance. Several slurries of stationary phase were prepared using different solvent mixtures. Their stability was evaluated at several temperatures: 70°C, 50°C, and room temperature. At the higher temperature (70°C) the suspensions resulted to be stable for a longer time. For each slurry, we compared nano‐LC columns packed with ultrasounds at 70°C and at room temperature. All the columns were tested with a standard mixture at 70°C, to reduce the solvent viscosity and the backpressure. Main chromatographic parameters such as the asymmetry factor, As, the reduced plate high, h, pattern in a Van Deemter plot, the total porosity, t, and the permeability, k, were calculated and discussed. One of the nano‐LC columns was used to separate a mixture of pesticides in a LC‐MS system with an electron ionization LC‐MS interface (Direct‐EI). From our knowledge, this is the first study on the role of temperature in the efficiency of slurry‐packing procedure.
Chiral amines as reagents for HPLC–MS enantioseparation of chiral carboxylic acids
Authors: Tsutsui Haruhito , Fujii Shinya , Sakamoto Tasuku , Min Jun Zhe , Todoroki Kenichiro , Toyo'oka Toshimasa
Published: July 2012

Mass spectrometry (MS) has become a popular analytical technique because of its high sensitivity and specificity. Therefore, the use of a chiral derivatization reagent for the MS detection seems to be efficient for the enantiomeric separation of racemates. However, the number of chiral reagents for the liquid chromatography (LC)–tandem mass spectrometry (MS/MS) analysis is very limited. The applicability of commercially available chiral amines as the derivatization reagents for the enantiomeric separation of chiral carboxylic acids is reported in this paper by using non‐steroidal anti‐inflammatory drugs (NSAIDs), i.e. ibuprofen, flurbiprofen, and loxoprofen. The efficiency of the chiral reagents was evaluated in terms of tagging easiness, separation by reversed‐phase chromatography, and detection sensitivity by electrospray ionization (ESI)–MS/MS. Among the tested eight chiral amines, i.e. (R)‐(+)‐4‐(3‐aminopyrrolidin‐1‐yl)‐7‐(N,N‐dimethylaminosulfonyl)‐2,1,3‐benzoxadiazole (DBD‐APy), (S)‐(+)‐1‐(2‐pyrrolidinylmethyl)‐pyrrolidine (PMP), l‐prolinamide, (3R)‐(−)‐1‐benzyl‐3‐aminopyrrolidine, (S)‐(+)‐1‐cyclohexyl‐ethylamine, (3R)‐(+)‐3‐(trifluoroacetamido)‐pyrrolidine (TFAP), (R)‐(−)‐1‐aminoindan (AI), and (S)‐(+)‐tetrahydrofurfuryl‐amine, DBD‐APy, PMP, AI, and TFAP could be used as the chiral reagents for the enantiomeric separation of the NSAIDs. The Rs values and the detection limits of the derivatives were in the range of 1.29–3.85 and 0.57–0.96 fmol, respectively. These four reagents were applied for the determination of the NSAIDs in rat plasma.
Separation of isomeric bavachin and isobavachalcone in the Fructus Psoraleae by capillary electrophoresis–mass spectrometry
Authors: Zhang Yulin , Chen Zilin
Published: July 2012

Bavachin and isobavachalcone are the isomeric compounds in the Fructus Psoraleae. The ion trap mass spectrometric fragmentation pathways of the bavachin and isobavachalcone in negative ion mode were elucidated for the identification. A novel method for determination of isomeric bavachin and isobavachalcone has been developed by capillary electrophoresis coupled with mass spectrometric detection. The effects of several factors such as concentration, pH of ammonium acetate buffer, separation voltage, composition and flow rate of the sheath liquid were investigated. Under optimal conditions, the linear concentration range for bavachin and isobavachalcone were 0.8–100 μg/mL with the correlation coefficient of 0.996 and 0.995, respectively. Relative standard deviations of migration time and peak areas were lower than 5%. The limits of detection (signal/noise = 3) were 60 ng/mL. The proposed method can be successfully applied to the determination of bavachin and isobavachalcone in the Fructus Psoraleae and six Fructus Psoraleae‐containing preparations.
Evaluation of toughening mechanisms of polypropylene/ethylene–octene copolymer/maleic anhydride‐grafted poly(ethylene‐co‐octene)/clay nanocomposite
Authors: Bagheri‐Kazemabad Sedigheh , Khavandi Alireza , Chen Biqiong
Published: July 2012

The toughness of a polypropylene (PP)/ethylene‐octene copolymer (EOC)/maleic anhydride‐grafted poly(ethylene‐co‐octene) (EOC‐g‐MA)/clay nanocomposite and blends of PP/EOC and PP/EOC/EOC‐g‐MA was investigated using Charpy impact and single‐edge‐notch tensile (SENT) tests. In order to understand the toughening mechanisms, impact fracture surfaces and damage zones of single‐edge‐notch samples were studied with scanning electron microscopy and transmission optical microscopy, respectively. It was observed that the addition of EOC‐g‐MA to PP/EOC blend led to improvements in both impact strength and fracture energy of SENT tests because of the enhanced compatibility of the blend, which resulted from reduced EOC particle size and improved interfacial adhesion, and the decreased crystallinity of PP. The incorporation of clay to PP/EOC/EOC‐g‐MA blend caused a further increase of the toughness, owing to the greater decrease in the size of elastomer particles, to the presence of clay tactoids inside the elastomer phase and presumably to debonding of clay layers during the low‐speed SENT tests. The results of microscopic observations showed that the main toughening mechanism in PP/EOC/EOC‐g‐MA blend and PP/EOC/EOC‐g‐MA/clay nanocomposite is crazing. Copyright © 2012 Society of Chemical Industry
Thermal and mechanical properties of poly(ε‐caprolactone)/polyhedral oligomeric silsesquioxane nanocomposites
Authors: Lee Kang Suk , Chang Young‐Wook
Published: July 2012

Poly(ε‐caprolactone) (PCL)/trisilanolphenyl polyhedral oligomeric silsesquioxane (TspPOSS) nanocomposites were prepared by solution mixing followed by film casting. Wide‐angle X‐ray diffraction and field‐emission scanning electron microscopy observations showed that the POSS molecules formed crystal domains and dispersed uniformly on the nanoscale in the PCL matrix. Fourier transform infrared analysis of the nanocomposites revealed that there are hydrogen‐bonded interactions between the silanol group of the TspPOSS and carbonyl oxygen of the PCL. Differential scanning calorimetry, tensile testing, and dynamic mechanical analysis (DMA) showed that, with increasing POSS content in the nanocomposites, the melting temperature and degree of crystallinity decreased while glass transition temperature, tensile modulus and strength increased without sacrificing the ductility of the PCL. DMA results also demonstrated the presence of a rubbery plateau above the melting temperature of the PCL/TspPOSS nanocomposites, and the moduli at the plateau region increased with increasing POSS content in the nanocomposites, implying that the PCL/TspPOSS nanocomposites formed a physically crosslinked structure. The physically crosslinked PCL/TspPOSS nanocomposites exhibited a thermally triggered shape memory effect. Copyright © 2012 Society of Chemical Industry
Quantitative proteomics of Trypanosoma cruzi during metacyclogenesis
Authors: de Godoy Lyris Martins Franco , Marchini Fabricio Klerynton , Pavoni Daniela Parada , Rampazzo Rita de Cássia Pontello , Probst Christian Macagnan , Goldenberg Samuel , Krieger Marco Aurelio
Published: July 2012

Trypanosoma cruzi is the etiologic agent of Chagas disease, which is estimated to affect over eight million people around the world. Trypanosoma cruzi has a complex life cycle, involving insect and mammalian hosts and four distinct developmental stages: epimastigotes, metacyclic trypomastigotes, amastigotes, and bloodstream trypomastigotes. Metacyclogenesis is the process by which T. cruzi epimastigotes differentiate into metacyclic trypomastigotes and acquire infectivity, and involves differential gene expression associated with acquisition of virulence. In T. cruzi, gene expression regulation is achieved mainly posttranscriptionally. Therefore, proteomics‐based approaches are extremely useful for gaining a better understanding of the changes that occur in the stage‐regulated gene expression program of the parasite at the molecular level. Here, we performed an in‐depth quantitative MS‐based proteomic study of T. cruzi metacyclogenesis and quantified almost 3000 proteins expressed during the process of differentiation. To the best of our knowledge, this work is the most comprehensive quantitative proteomics study of different cell populations of T. cruzi available so far. We identified relevant proteins and pathways involved in the parasite's differentiation and infectivity acquisition, opening new perspectives for further studies that could, ultimately, lead to the identification of new targets for chemotherapy.
Proteomic profiling of skeletal muscle in an animal model of overtraining
Authors: Gandra Paulo Guimaraes , Valente Richard Hemmi , Perales Jonas , Pacheco Antonio Guilherme Fonseca , Macedo Denise Vaz
Published: July 2012

Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re‐establish performance (i.e. functional overreaching (FOR), nonfunctional overreaching, OT syndrome). The present study is an initial screening for proteins presenting altered abundance in the red (RG) and white (WG) portions of the gastrocnemius muscle from rats submitted to an OT protocol that induced FOR. In the RG, compared to the nontrained control, FOR demonstrated an increased abundance of proteins normally related to adaptation to endurance training (e.g. proteins of oxidative phosphorylation complexes, proteins related to lipid metabolism, antioxidants, and chaperones). In the WG, spots identified as mitochondrial aconitase and a component of the succinate dehydrogenase complex were downregulated in FOR, as were proteins related to myofibril stabilization; these latter were upregulated in the RG. This initial study shows that skeletal muscles with different fiber‐type compositions respond differently to an OT period. Also, it is likely that actin‐interacting proteins have an important role in muscle adaptation to endurance exercise.
Insecticide susceptibility status in three medically important species of mosquitoes, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus, from Bruhat Bengaluru Mahanagara Palike, Karnataka, India
Authors: Shetty Vinaya , Sanil Deepak , Shetty Nadikere Jaya
Published: July 2012

BACKGROUND: Development of resistance among mosquito vectors of diseases is of growing concern in many countries of the subtropics, including much of India. The distributions of susceptibility/resistance to insecticides are scarcely recorded and are unknown in many parts of India. This manuscript reports the susceptibility status among strains of Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus collected from different geographical areas of Bruhat Bengaluru Mahanagara Palike (BBMP), Karnataka, to six conventionally used insecticides.

RESULTS: An. stephensi, Ae. aegypti and Cx. quinquefasciatus from different geographic areas showed susceptibility towards temephos. However, susceptibility was meagre for most of the other insecticides used in the study. Strong resistance to propoxur was reported in Ullala (RR90 = 467.1) and Bannerghatta (RR90 = 12 265) populations of An. stephensi and Ae. aegypti respectively. RR90 ≥ 12 830 was recorded as higher in the Yelahanka (YLK) population of Cx. quinquefasciatus to neem. Significant differences at LC50 and LC90 concentrations were observed against various insecticides in different mosquito populations. Resistance was observed against some of the larvicides for the diagnostic dose recommended by WHO.

CONCLUSION: The results form baseline data on the susceptibility status of three medically important mosquito vectors of diseases to commonly used insecticides in the field at present emphasise the importance of carrying out more effective and planned vector control measures. Copyright © 2012 Society of Chemical Industry
Development of a multiplex allele‐specific primer PCR assay for simultaneous detection of QoI and CAA fungicide resistance alleles in Plasmopara viticola populations
Authors: Aoki Yoshinao , Hada Yosuke , Suzuki Shunji
Published: July 2012

BACKGROUND: DNA‐based diagnosis has become a common tool for the evaluation of fungicide resistance in obligate phytopathogenic fungus Plasmopara viticola.

RESULTS: A multiplex allele‐specific primer PCR assay has been developed for the rapid detection of fungicide resistance in P. viticola populations. With this assay, a glycine‐to‐alanine substitution at codon 143 of the P. viticola cytochrome b gene, which conferred QoI fungicide resistance, and a glycine‐to‐serine substitution at codon 1105 of the P. viticola cellulose synthase gene PvCesA3, which conferred CAA fungicide resistance, were detected simultaneously.

CONCLUSION: It is suggested that the present assay is a reliable tool for the rapid and simultaneous detection of QoI and CAA fungicide resistance alleles in P. viticola populations. The assay required only 2 h from the sampling of symptoms to the detection of resistance alleles to both fungicides. Copyright © 2012 Society of Chemical Industry
Hantavirus infections in Europe and their impact on public health
Authors: Vaheri Antti , Henttonen Heikki , Voutilainen Liina , Mustonen Jukka , Sironen Tarja , Vapalahti Olli
Published: July 2012

Hantaviruses (genus Hantavirus, family Bunyaviridae) are enveloped tri‐segmented negative‐stranded RNA viruses each carried by a specific rodent or insectivore host species. Several different hantaviruses known to infect humans circulate in Europe. The most common is Puumala (PUUV) carried by the bank vole; another two important, genetically closely related ones are Dobrava–Belgrade (DOBV) and Saaremaa viruses (SAAV) carried by Apodemus mice (species names follow the International Committee on Taxonomy of Viruses nomenclature). Of the two hantaviral diseases, hemorrhagic fever with renal syndrome (HFRS) and hantaviral cardiopulmonary syndrome, the European viruses cause only HFRS: DOBV with often severe symptoms and a high case fatality rate, and PUUV and SAAV more often mild disease. More than 10,000 HFRS cases are diagnosed annually in Europe and in increasing numbers. Whether this is because of increasing recognition by the medical community or due to environmental factors such as climate change, or both, is not known. Nevertheless, in large areas of Europe, the population has a considerable seroprevalence but only relatively few HFRS cases are reported. Moreover, no epidemiological data are available from many countries. We know now that cardiac, pulmonary, ocular and hormonal disorders are, besides renal changes, common during the acute stage of PUUV and DOBV infection. About 5% of hospitalized PUUV and 16%–48% of DOBV patients require dialysis and some prolonged intensive‐care treatment. Although PUUV–HFRS has a low case fatality rate, complications and long‐term hormonal, renal, and cardiovascular consequences commonly occur. No vaccine or specific therapy is in general use in Europe. We conclude that hantaviruses have a significant impact on public health in Europe. Copyright © 2012 John Wiley & Sons, Ltd.
A test for emergent dynamics
Authors: Hook Anson
Published: July 2012

Abstract

A generalization of a-maximization is proposed that maximizes a subject to inequalities rather than equalities. An implication of this conjecture is that in the absence of emergent symmetries, there is a maximum R-charge for fields appearing in the path integral. This maximum R-charge leads to a novel way of detecting emergent Abelian symmetries and non-Abelian gauge symmetries.
Tuning supersymmetric models at the LHC: a comparative analysis at two-loop level.
Authors: Ghilencea D. M. , Lee H. M. , Park M.
Published: July 2012

Abstract

We provide a comparative study of the fine tuning amount (Δ) at the two-loop leading log level in supersymmetric models commonly used in SUSY searches at the LHC. These are the constrained MSSM (CMSSM), non-universal Higgs masses models (NUHM1, NUHM2), non-universal gaugino masses model (NUGM) and GUT related gaugino masses models (NUGMd). Two definitions of the fine tuning are used, the first (Δmax) measures maximal fine-tuning w.r.t. individual parameters while the second (Δ
q
) adds their contribution in “quadrature”. As a direct consequence of two theoretical constraints (the EW minimum conditions), fine tuning (Δ
q
) emerges at the mathematical level as a suppressing factor (effective prior) of the averaged likelihood (
$ L $
) under the priors, under the integral of the global probability of measuring the data (Bayesian evidence p(D)). For each model, there is little difference between Δ
q
, Δmax in the region allowed by the data, with similar behaviour as functions of the Higgs, gluino, stop mass or SUSY scale (
$ {m_{\text{SUSY}}} = {\left( {{m_{{\overline t 1}}}{m_{{\overline t 2}}}} \right)^{{{{1} \left/ {2} \right.}}}} $
) or dark matter and g − 2 constraints. The analysis has the advantage that by replacing any of these mass scales or constraints by their latest bounds one easily infers for each model the value of Δ
q
, Δmax or vice versa. For all models, minimal fine tuning is achieved for M
higgs near 115 GeV with a Δ
q
 ≈ Δmax ≈ 10 to 100 depending on the model, and in the CMSSM this is actually a global minimum. Due to a strong (≈ exponential) dependence of Δ on M
higgs, for a Higgs mass near 125 GeV, the above values of Δ
q
 ≈ Δmax increase to between 500 and 1000. Possible corrections to these values are briefly discussed.
A note on supersymmetric type II solutions of Lifshitz type
Authors: Petrini Michela , Zaffaroni Alberto
Published: July 2012

Abstract

We discuss a class of supersymmetric type II non-relativistic solutions with exact or asymptotic scale invariance. As already emerged from previous investigations, we find a clear correspondence between anisotropic d-dimensional vacua and relativistic solutions in d+1 dimensions. We will show that supersymmetric four-dimensional Poincaré invariant backgrounds in type IIB can descend to analogous solutions with anisotropic scaling in t and (x, y). This result can be applied to scale invariant theories, domain walls interpolating between four-dimensional Lifshitz vacua and more general solutions with only asymptotic, approximate scaling behaviour and hyperscaling violation.
The importance of local and landscape‐scale processes to the occupancy of wetlands by pond‐breeding amphibians
Authors: Scherer Rick D. , Muths Erin , Noon Barry R.
Published: July 2012

Variation in the distribution and abundance of species across landscapes has traditionally been attributed to processes operating at fine spatial scales (i.e., environmental conditions at the scale of the sampling unit), but processes that operate across larger spatial scales such as seasonal migration or dispersal are also important. To determine the relative importance of these processes, we evaluated hypothesized relationships between the probability of occupancy in wetlands by two amphibians [wood frogs (Lithobates sylvaticus) and boreal chorus frogs (Pseudacris maculata)] and attributes of the landscape measured at three spatial scales in Rocky Mountain National Park, Colorado. We used cost‐based buffers and least‐cost distances to derive estimates of landscape attributes that may affect occupancy patterns from the broader spatial scales. The most highly ranked models provide strong support for a positive relationship between occupancy by breeding wood frogs and the amount of streamside habitat adjacent to a wetland. The model selection results for boreal chorus frogs are highly uncertain, though several of the most highly ranked models indicate a positive association between occupancy and the number of neighboring, occupied wetlands. We found little evidence that occupancy of either species was correlated with local‐scale attributes measured at the scale of individual wetlands, suggesting that processes operating at broader scales may be more important in influencing occupancy patterns in amphibian populations.
Biological pest control by investing crops in pests
Authors: Ito Hiroshi C. , Kondo Natsuko I.
Published: July 2012

We propose a biological pest control system that invests part of a crop in feeding a pest in a cage. The fed pest maintains a predator that attacks the pest in the target area (i.e., the area for storing or growing crops). The fed pest cannot leave the cage nor the target pest cannot enter the cage. The predator, however, can freely attack both the fed and target pests in the target area. By introducing a refuge in the cage against the predator for the fed pest, the fed pest and predator may be stably sustained. In this study, we analyzed the potential performance of this system by modeling the population dynamics of the target pest, fed pest, and predator as differential equations. First, we show analytically that the target pest can be suppressed at extremely low abundance by adjusting both refuge efficiency and crop investment. Second, we show numerically that crop damage by the pest may be effectively suppressed by investing only small amounts of the crop. Third, we show numerically that the magnitude of required crop investment can be estimated by an index comprising of the predator's searching cost for prey and the relative growth efficiency of the predator with respect to the pest. Even if the system structure is changed or its population dynamics is modeled based on host–parasitoid interactions, crop damage can be suppressed effectively by small amounts of crop investment.
Microbial Oxidation of Medium Chain Fatty Alcohol in the Synthesis of Sophorolipids by Candida bombicola and its Physicochemical Characterization
Authors: Dengle Pulate Vrushali , Bhagwat Sunil , Prabhune Asmita
Published: July 2012

Sophorolipids (SL) are glycolipid biosurfactants abundantly produced from different feedstocks by yeasts and have been widely developed for various applications. The amphipathic structures of sophorolipids imparts to them surfactant type properties. These biosurfactants are readily isolated in high yield and are nontoxic and biodegradable, which make them industrially interesting as surfactants or emulsifiers. Sophorolipid production was carried out using glucose as a hydrophilic source and lauryl alcohol C12–14, as a hydrophobic source by Candida bombicola (ATCC 22214). Process economics and environmental attractiveness was increased by using a low cost substrate. Optimization studies were carried out where the effect of glucose concentration, pH, temperature and metal ions on sophorolipid production was studied. Optimum production of sophorolipid obtained using lauryl alcohol (SLLA) was achieved after 96 h, the initial pH of the medium was 6.0 with 10 % glucose at 30 °C. Primary characterization of SLLA was done by FTIR. The SLLA showed high physicochemical properties in terms of the surface activities when compared with synthetic surfactants including dodecyl tetraethylene glycol ether and sodium lauryl sulfate. The surface tension of SLLA thus obtained was found to be 24 mN/m with a critical micellar concentration (CMC) value of 0.68 mg/L. Antimicrobial testing showed that SLLA have potent antimicrobial activity against both gram negative bacteria, Escherichia coli (ATCC 8739) and gram positive cocci, Staphylococcus aureuss (ATCC 2079).
Service Backstage Visibility and the Corresponding Perceived Values in the Process of Service Delivery
Authors: Huang Yu-Ying
Published: July 2012

Increasingly service providers show customers some activities originally in the backstage but few are known about the phenomenon from theoretical viewpoints. The purpose of this study is to conduct an exploratory investigation of positive backstage visibility and the corresponding perceived values. The CIT method was applied to analyze 387 service experiences in Greater China (including Mainland China, Macau, and Taiwan). The categorization of backstage visibility was classified by two dimensions (complexity and attractiveness), and the corresponding perceived values for backstage visibility for each category of backstage visibility was discussed. The main findings of this study include that (1) the visualized backstage could become a differentiated strategy or tangible clue for services, and (2) the contents of dramaturgy theory should be adjusted to be suitable in the business practices today.
Safety and resource utilization of anterior cervical discectomy and fusion
Authors: Feng Yu‐Tung , Hwang Shiuh‐Lin , Lin Chih‐Lung , Lee I‐Chen , Lee King‐Teh
Published: July 2012

Degenerative cervical spondylosis (DCS) is part of the aging process and is the most common reason for degenerative changes with the spinal column. Anterior cervical discectomy and fusion (ACDF) is a major option for operative management of DCS in our institution. This retrospective study investigated the frequency of postoperative complications and resource utilization in 145 patients who underwent ACDF procedures from January 2009 to December 2011. Patients with degenerative changes that involved cervical intervertebral levels C1–C2, spinal injury of traumatic origin, spinal tumors, or previous cervical fusion were excluded. Patients were then further classified into two groups: (1) level 1 or 2 disease (Group M) and (2) level 3 or 4 disease (Group S). Measures of mortality, complications after surgery as well as immediate reoperation for any reason were evaluated. Operation time, length of hospital stay, and hospitalization cost were defined as resource utilization. Ninety seven patients met the inclusion criteria and were further reviewed to characterize the sample better. There were no hematomas, airway complications or deaths, except in one patient who developed postoperative hemorrhage that required immediate surgical intervention, and resolved without any neurological deficit or casualty. Resource utilization indicated that the average operation time for Group S was significantly higher than for Group M (4.31 ± 1.25 vs. 2.88 ± 0.90 hours, p < 0.0001). There were no significant differences in length of hospital stay and hospitalization cost between the two groups (p = 0.265 and p = 0.649). Our results indicate that neurosurgical intervention is safe for patients with DSC. Postoperative complication rates associated with these procedures are low. When surgery is considered appropriate for patients with multilevel diseases, these data suggest that ACDF is a safe surgical option.