bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation in predator species abundance can cause variable selection pressure on warning signaling prey
Authors: Valkonen Janne K. , Nokelainen Ossi , Niskanen Martti , Kilpimaa Janne , Björklund Mats , Mappes Johanna
Published: July 2012

Predation pressure is expected to drive visual warning signals to evolve toward conspicuousness. However, coloration of defended species varies tremendously and can at certain instances be considered as more camouflaged rather than conspicuous. Recent theoretical studies suggest that the variation in signal conspicuousness can be caused by variation (within or between species) in predators' willingness to attack defended prey or by the broadness of the predators' signal generalization. If some of the predator species are capable of coping with the secondary defenses of their prey, selection can favor reduced prey signal conspicuousness via reduced detectability or recognition. In this study, we combine data collected during three large‐scale field experiments to assess whether variation in avian predator species (red kite, black kite, common buzzard, short‐toed eagle, and booted eagle) affects the predation pressure on warningly and non‐warningly colored artificial snakes. Predation pressure varied among locations and interestingly, if common buzzards were abundant, there were disadvantages to snakes possessing warning signaling. Our results indicate that predator community can have important consequences on the evolution of warning signals. Predators that ignore the warning signal and defense can be the key for the maintenance of variation in warning signal architecture and maintenance of inconspicuous signaling.
Trimetallic [M3(dpa)4]2+ Complexes (M = Co, Ni) as Building Blocks for Cyano‐Bridged Coordination Polymers
Authors: Wang Jingfang , Ozarowski Andrew , Kovnir Kirill , Thompson Corey M. , Yaroslavtsev Alexander A. , Chernikov Roman V. , Dalal Naresh S. , Shatruk Michael
Published: July 2012

Reactions between the complexes M3(dpa)4Cl2 (M = Co, Ni; dpa = 2,2′‐dipyridylamine), which contain linear trimetallic fragments, and (Bu4N)3[M′(CN)6] (M′ = Fe, Co) result in the formation of CN‐bridged coordination polymers. The analysis of the products obtained suggests that they have a two‐dimensional structure, in which ditopic [M3(dpa)4]2+ linkers bridge 4‐connected [M′(CN)6]3– nodes into an extended layer. The synthesis of {[Co3(dpa)4]1.97[Fe(CN)6]}Cl0.8 (1) is accompanied by an electron transfer from the tricobalt to the hexacyanoferrate units, which results in the formation of [Co3(dpa)4]3+ and [Fe(CN)6]4– fragments. In {[Ni3(dpa)4]1.74[Fe(CN)6]}Cl0.45 (3), a partial charge transfer between the trinickel and the hexacyanoferrate units leads to the temperature‐dependent FeIII/FeII mixed valence, and lower temperatures favor the thermodynamic FeIII ground state. {[Co3(dpa)4]2.06[Co(CN)6]}Cl1.1 (2) exhibits spin‐glass behavior with a spin‐freezing point of approximately 4.8 K, which is due to the magnetic superexchange between the paramagnetic [Co3(dpa)4]2+ (S = 1/2) units through the diamagnetic [Co(CN)6]3– linkers.
Gold‐catalyzed synthesis of dicarboxylic and monocarboxylic acids
Authors: Kulik Anna , Janz Alexander , Pohl Marga‐Martina , Martin Andreas , Köckritz Angela
Published: July 2012

Vicinal dihydroxy derivatives of oleic acid, methyl oleate, and erucic acid were converted by oxidative cleavage to the respective di‐ and monocarboxylic acids according to an environmentally benign process carried out in the presence of supported gold catalysts and molecular oxygen as oxidant in an aqueous‐basic medium. Au(0) nanoparticles with particle sizes between 0.5 and 4.1 nm were deposited as catalytically active species on different oxidic supports. The influence of the catalyst composition and morphology as well as of the reaction conditions on conversion of dihydroxy fatty acids and yields of products were investigated. Thus, the reaction of 9,10‐dihydroxystearic acid catalyzed by Au/Al2O3 leads to azelaic acid (86% yield) and pelargonic acid (99% yield).
Improved method for the determination of wax esters in vegetable oils
Authors: Carelli Amalia A. , Bäumler Erica B. , Ceci Liliana N.
Published: July 2012

In this work, a modified International Olive Council (IOC) method for wax determination involving a double‐adsorbent layer of silica gel and silver nitrate‐impregnated silica gel is presented (SN method). Column chromatography by the SN method did not show retention of wax esters standards with an even number of carbon atoms (C34–C44), observing recovery percentages higher than 90% even for unsaturated wax esters. All wax fractions were lower by the SN method than by the IOC method, resulting in a percentage decrease in the total wax content (olive oils: 20–50%, crude sunflower oil: 38%, crude soybean oil: 58% and crude grape seed oil: 13%). Olive oils analysed by the SN method showed increases of up to 27% in C40 relative percentage with respect to the IOC method. Additionally, decreases were observed by the SN method in the relative percentages for odd‐carbon atom waxes for the seed oils in comparison to the IOC method (crude sunflower oil: 27%, crude soybean oil: 28% and crude grape seed oil: 13%). The main advantages of the proposed modification consist in its easy implementation and a better determination of wax esters (C34–C60) by controlling their complete recovery and removing interfering substances. The method is suitable for quality control and for authentication of olive oil and seed oils as well as in processing monitoring.

Practical applications: The proposed method is useful in the quality, authentication and processing control of fruit and seed oils. Moreover, it can be an important tool for vegetable oil industries to control the efficiency of the wax separation process to prevent turbidity in the refined oil.
Rapid determination of cholesterol in emulsified confectioneries by ultra‐performance liquid chromatography
Authors: Ahn Jang‐Hyuk , Jeong In‐Seek , Kwak Byung‐Man , Leem Donggil , Yoon Taehyung , Yoon Changyong , Jeong Jayoung , Park Jung‐Min , Kim Jin‐Man
Published: July 2012

We developed a sample preparation method by using no‐heating saponification after dispersive SPE and ultra‐performance liquid chromatography for rapid determination of cholesterol in emulsified foods, such as cream pie, cream sandwich‐type biscuit, plate chocolate, and chocobar. Optimum cholesterol extraction was obtained by using 10 mL isopropyl alcohol and 8.0 g (NH4)2SO4 per 1–2 g sample; saponification after extraction was performed using 25 mg KOH, 0.8 g NaCl, and 100 mg of a silica based NH2 SPE material. The determined cholesterol concentration was within certified reference material limits, and results of the recovery test were in the range of 97.4 to 104.8% with a relative standard deviation between 2.14 and 3.80%. Since our method had less sample preparation and chromatographic separation times, we expect our method to be used for effective quality control processes for monitoring cholesterol concentrations in confectioneries.

Practical applications: A rapid analytical method for determining the cholesterol concentration in emulsified confectioneries was developed by using UPLC. The assessed cholesterol levels after comparing them with the CRMs were within the permissible range; results of the recovery tests performed using spiked materials ranged from 97.4 to 104.8% with RSD between 2.14 and 3.80%. Thus, our method could be used for accurate and precise determination of cholesterol concentration at low analysis and pretreatment time.
2′‐Modified Neamine Analogues from Thiomannosides through Glycosidation–Stereoinversion
Authors: Gironés Daniel , Hanckmann Marcel , Rutjes Floris P. J. T. , van Delft Floris L.
Published: July 2012

Conveniently protected neamine analogues were synthesized with a free 2′‐OH group for further functionalization. An approach was investigated involving a stereoselective α‐glycosidation reaction of 3,4‐O‐dimethoxybutanediyl‐2‐O‐silyl protected thiomannosides with a 2‐deoxystreptamine derivative. Subsequent 2‐O‐deprotection followed by anoxidation–reduction sequence led to α‐glucosides withstereoinversion at C‐2′. The scope of the procedure for the syntheses of α‐glucosides was explored with three distinct model acceptors. Thiomannoside coupling, 2‐O‐deprotection, and oxidation were straightforward, whereas the outcome of the reduction step was clearly acceptor‐dependent.
Oxidative Coupling of Enolates, Enol Silanes, and Enamines: Methods and Natural Product Synthesis
Authors: Guo Fenghai , Clift Michael D. , Thomson Regan J.
Published: July 2012

Oxidative coupling of enolates, enol silanes, and enamines provides a direct method for the construction of useful 1,4‐dicarbonyl synthons. Despite its first being reported in 1935, with subsequent important advances beginning in the 1970s, the development of this powerful reaction into a reliable methodology was somewhat limited. In recent years, though, there have been a number of reports from several research groups demonstrating advances in several neglected areas of oxidative coupling. This microreview summarizes these new advances in methodology and provides an overview of recent natural product syntheses that showcase the power of these transformations.
A well‐defined block copolymer serving as surfactants in separation of 1,4‐dihydropyridines by open‐tubular capillary eletrochromatography
Authors: Li Yaping , Qi Li , Qiao Juan , Shen Ying , Yan Huijuan , Xin Peiyong , Ma Huimin
Published: July 2012

A novel series of diblock copolymers, poly(butyl methacrylate)n‐block‐poly(glycidyl methacrylate)m [P(BMA)n‐b‐P(GMA)m], were synthesized by atom transfer radical polymerization and developed as covalent coating of capillaries. The excellent performance of this coating in separation of three 1,4‐dihydropyridines (DHPs) derivatives (amlodipine, nicardipine, nitrendipine) was achieved when the diblock copolymers self‐assembled into micelles, which was confirmed by transmission electron microscopy, dynamic light scattering, and atom force microscopy. Meanwhile, the effects of block ratio n/m, pH value, buffer concentration, and organic solvents on the separation of 1,4‐DHPs were investigated in detail. Then, the relationship between the morphologies of copolymers and the separation resolutions of 1,4‐DHPs was discussed. Furthermore, the proposed method exhibited good run‐to‐run and column‐to‐column precision with relative standard deviations of electroosmotic flow less than 3.0%. It was also validated with linearity of three 1,4‐DHPs in the range of 0.01–1.80 mM (r2 ≥ 99.7%), efficient recovery (94–103%), and good repeatability (≤ 3.8%). In addition, three 1,4‐DHPs were successfully separated in the spiked human serum sample, which indicated the potential utility of this method in biological sample analysis.
Optimization of protein sample preparation for two‐dimensional electrophoresis
Authors: Valente Kristin N. , Choe Leila H. , Lenhoff Abraham M. , Lee Kelvin H.
Published: July 2012

Optimized 2DE sample preparation protocols that maximize total protein recovery are fundamental to improving proteome capture and increasing the utility of 2DE, which is in part limited by inadequate recovery of proteins with diverse physicochemical properties. Maintaining protein solubility is an important factor for protein recovery, but the multitude of solubility‐enhancing agents and the relatively low‐throughput nature of 2DE limit the systematic study of sample preparation. In this work, design of experiment (DOE) approaches are used to optimize protein recovery by altering the levels of four solubility‐enhancing agents (urea, DTT, CHAPS, and SDS) in the initial suspension solution. Protein recovery is quantified by a total protein concentration assay, which is demonstrated to be representative of SDS‐PAGE and 2DE recovery. DOE methodologies are presented as relatively high‐throughput procedures for optimizing 2DE sample preparation parameters for a variety of sample types. Optimal suspension solution compositions are shown to vary across a model protein solution (no urea or DTT), Chinese hamster ovary (CHO) cell lysate (8 M urea, ≥2% CHAPS, ≥32.5 mM DTT), and Escherichia coli cell lysate (8 M urea, 4% CHAPS, 65 mM DTT), with optimized conditions increasing 2DE protein recovery at least 50% compared to suboptimal conditions.
Longitudinal analysis of novel Alzheimer's disease proteomic cerebrospinal fluid biomarkers during intravenous immunoglobulin therapy
Authors: Shayan Gilda , Adamiak Basia , Relkin Norman R. , Lee Kelvin H.
Published: July 2012

Intravenous immunoglobulin (IVIg) therapy has shown promising results in treating Alzheimer's disease (AD). In this study, a Random Forest (RF) classification model was used to identify possible effects of IVIg on a group of eight subjects who underwent immunotherapy. Cerebrospinal fluid (CSF) samples from eight ADsubjects who underwent IVIg therapy were collected before therapy, after 6 months of therapy, and after a 3‐month drug washout period. Samples were analyzed using 2DE and further studied using a RF classification model to identify effects of IVIg on a panel of 23 putative diagnostic ADbiomarkers previously identified. Six of the eight subjects showed improvements with respect to the 23 ADdiagnostic biomarkers after 6 months of therapy compared to the samples taken at the outset of the trial. All subjects reverted back to baseline during drug washout. These results are also consistent with clinical observations. The observed improvements in subjects during 6 months of IVIg therapy and the reversion back to baseline during drug washout provides preliminary evidence regarding the potential use of IVIg as an AD immunotherapy.
An integrated workflow for extraction and solubilization of intermediate filaments from colorectal biopsies for proteomic analysis
Authors: Majumdar Debabrata , Rosser Ria , Havard Suzanne , Lobo Alan J. , Wright Phillip C. , Evans Caroline A. , Corfe Bernard M.
Published: July 2012

We report a technique for isolation and solubilization of intermediate filament (IF) proteins from colonic biopsies compatible with both gel electrophoresis and liquid chromatography “shotgun” proteomics using mass spectrometry (MS). This is important because changes in the IF proteome, particularly in keratin expression and modification, are noted in colonic mucosa of patients with colorectal cancer. Though keratins have traditionally been dissolved in high concentration of urea, the latter solvent precludes efficient proteolytic digestion by trypsin prior to gel‐free LC‐MS/MS approaches. The extraction of cytoskeletal proteins was initially evaluated using MCF‐7 cancer cell lines using a published, differential detergent solubilization protocol. IF proteins were extracted from colonic biopsies using a combination of homogenization and sonication. Since comparable efficiency of solubilization was noted on the extracted IF from cell lines between urea and guanidine hydrochloride (GuHCl) in triethylammonium bicarbonate buffer, isolated proteins from endoscopic biopsies were solubilized in GuHCl. Using immunoblotting techniques, we successfully demonstrated isolation of keratins and preservation of posttranslational modifications (phosphorylation, acetylation). Dissolved proteins were tryptically digested and peptides analyzed by MS, showing the functionality of the workflow in shotgun proteomic applications, specifically compatibility of the workflow for isobaric tagging relative and absolute quantification based quantitation approaches.
Multilayer contactless dielectrophoresis: Theoretical considerations
Authors: Sano Michael B. , Salmanzadeh Alireza , Davalos Rafael V.
Published: July 2012

Dielectrophoresis (DEP), the movement of dielectric particles in a nonuniform electric field, is of particular interest due to its ability to manipulate particles based on their unique electrical properties. Contactless DEP (cDEP) is an extension of traditional and insulator‐based DEP topologies. The devices consist of a sample channel and fluid electrode channels filled with a highly conductive media. A thin insulating membrane between the sample channel and the fluid electrode channels serves to isolate the sample from direct contact with metal electrodes. Here we investigate, for the first time, the properties of multilayer devices in which the sample and electrode channels occupy distinct layers. Simulations are conducted using commercially available finite element software and a less computationally demanding numerical approximation is presented and validated. We show that devices can be created that achieve a similar level of electrical performance to other cDEP devices presented in the literature while increasing fluid throughput. We conclude, based on these models, that the ultimate limiting factors in device performance resides in breakdown voltage of the barrier material and the ability to generate high‐voltage, high‐frequency signals. Finally, we demonstrate trapping of MDA‐MB‐231 breast cancer cells in a prototype device at a flow rate of 1.0 mL/h when 250 VRMS at 600 kHz is applied.
Nano‐constriction device for rapid protein preconcentration in physiological media through a balance of electrokinetic forces
Authors: Liao Kuo‐Tang , Tsegaye Mikiyas , Chaurey Vasudha , Chou Chia‐Fu , Swami Nathan S.
Published: July 2012

We describe a methodology to steeply enhance streptavidin protein preconcentration within physiological media over that achieved by negative dielectrophoresis (NDEP) through utilizing a DC offset to the AC field at nanoscale constriction gap devices. Within devices containing approximately 50‐nm constriction gaps, we find that the addition of a critical DC field offset (1.5 V/cm) to the NDEP condition (∼200 Vpp/cm at 1 MHz) results in an exponentially enhanced extent of protein depletion across the device to cause a rapid and steeply rising degree of protein preconcentration. Under these conditions, an elliptical‐shaped protein depletion zone that is extended along the device centerline axis forms instantaneously around the constrictions to result in protein preconcentration along the constriction sidewall direction. Through a potential energy diagram to describe the electrokinetic force balance across the device, we find that the potential energy barrier due to NDEP is gradually tilted upon addition of DC fields, to cause successively steeper potential wells along the sidewall direction for devices containing smaller constriction gaps. Hence, for approximately 50‐nm constriction gaps at a critical DC field, the ensuing narrow and deep potential energy wells enable steep protein preconcentration, due to depletion over an exponentially enhanced extent across the device.
Micellar nanotubes dispersed electrokinetic chromatography for the simultaneous determination of antibiotics in bovine milk
Authors: Springer Valeria H. , Lista Adriana G.
Published: July 2012

A method to determine four antibiotics for veterinary use (ciprofloxacin, enrofloxacin, florfenicol, and chloramphenicol) of different families (fluoroquinolones and amphenicols) in bovine milk was developed. The determination of the analytes was carried out using micellar electrokinetic capillary chromatography (MEKC) with a common sodium borate‐SDS buffer solution containing single‐walled carbon nanotubes (SWCNTs). In this way, a great improvement in the electrophoretic resolution and the separation efficiency was achieved compared to MEKC. An online reverse electrode polarity‐stacking mode (REPSM) was carried out to enhance sensitivity. This step was performed in only 2 min and it allowed a stacked percentage of 103. That means that all the amount of injected analytes is effectively stacked. When this stacking procedure was combined with an off‐line preconcentration step, based on SPE, analytes could be detected in lower concentration than the established maximum residue limits (MRLs). The LODs for the four compounds were between 6.8 and 13.8 μg L−1 and the RSD values were between 1.1% and 6.6%. The whole method was applied to spiked real samples with acceptable precision and satisfactory recoveries.
One‐pot synthesis of N‐methylimidazolium‐based porous polymer monolith for capillary electrochromatography via free radical copolymerization and quaterisation
Authors: Li Yi , Chen Yingzhuang , Wang Keyi , Nie Lihua , Yao Shouzhuo
Published: July 2012

One‐pot synthesis of porous polymer monolith decorated with N‐methylimidazolium in a capillary was described. The polymer matrix was synthesized by in situ copolymerization and quaterization of 3‐chloro‐2‐hydroxylpropyl methacrylate (CHPMA), ethylene dimethacrylate (EDMA), and N‐methylimidazole (N‐MIz). The influencing factors including amount of cross‐linkers, composition of porogenic solvents, and polymerization temperature on the formation of the monolithic column were investigated. The monolithic column exhibited high column efficiency for thiourea, up to 135 000 plates per meter, and phenylmethanol, up to 102 000 plates per meter. Different types of compounds including alkylbenzenes, phenols, and inorganic anions were successfully baseline separated by capillary electrochromatography (CEC). The separation of theses analytes on the column indicated typical reversed‐phase and anion‐exchange chromatographic retention mechanism.
Altered posttranslational modification on U1 small nuclear ribonucleoprotein 68k in systemic autoimmune diseases detected by 2D Western blot
Authors: Nagai Kouhei , Arito Mitsumi , Takakuwa Yukiko , Ooka Seido , Sato Toshiyuki , Kurokawa Manae S. , Okamoto Kazuki , Uchida Teisuke , Suematsu Naoya , Kato Tomohiro
Published: July 2012

Anti‐ribonucleoprotein (anti‐RNP) antibodies are one of the representative autoantibodies detectable in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). Generally, posttranslational modifications (PTMs) on autoantigens are proposed to be involved in the production of autoantibodies. In this study, we tried to detect the alteration in PTMs on a U1 small nuclear RNP 68k subunit (U1‐68k), a major antigen of anti‐RNP antibodies. Peripheral blood mononuclear cells (PBMCs) were obtained from patients with MCTD, SLE, and rheumatoid arthritis (RA), and from healthy donors. U1‐68ks in the PBMCs were detected by 2D Western blot (WB), where extracted nuclear proteins were separated by 2DE, followed by the detection of U1‐68k using WB. More than 20 PTM isoforms were detected with different molecular weights of 65.0 , 66.5, and 68.0kDa, and different pIs between 6.0 and 8.5. Importantly, the relative intensity of the spot with 66.5 kDa and pI 7.5 was significantly increased in the MCTD and SLE groups compared to the RA and healthy groups. Further, this U1‐68k isoform, in particular, in its RS domain, was found to have significantly decreased phosphorylation compared to the other isoforms. The PTM alternation may be one of the steps to generate the anti‐RNP antibodies.
Quantitative assessment of flow and electric fields for electrophoretic focusing at a converging channel entrance with interfacial electrode
Authors: Keebaugh Michael W. , Mahanti Prasun , Hayes Mark A.
Published: July 2012

The electric field and flow field gradients near an electrified converging channel are amenable to separating and focusing specific classes of electrokinetic material, but the detailed local electric field and flow dynamics in this region have not been thoroughly investigated. Finite elemental analysis was used to develop a model of a buffer reservoir connected to a smaller channel to simulate the electrophoretic and flow velocities (which correspond directly to the respective electric and flow fields) at a converging entrance. A detailed PTV (Particle Tracking Velocimetry) study using charged fluorescent microspheres was performed to assess the model validity both in the absence and presence of an applied electric field. The predicted flow velocity gradient from the model agreed with the PTV data when no electric field was present. Once the additional forces that act on the large particles required for tracing (dielectrophoresis) were included, the model accurately described the velocity of the charged particles in electric fields.
Modeling a Reversible Solid Oxide Fuel Cell as a Storage Device Within AC Power Networks
Authors: Ren J. , Gamble S. R. , Roscoe A. J. , Irvine J. T. S. , Burt G.
Published: July 2012

A reversible solid oxide fuel cell (RSOFC) system, consisting of a RSOFC stack, heat store, and electrical inverters to convert DC to AC power, is shown by computer modeling to have the potential to efficiently store electrical energy. This paper describes the modeling of a single RSOFC, based on a proposed cell geometry, empirical data on the resistivities of the components, and calculation of activation and diffusion polarization resistances from electrochemical theory. Data from ac impedance spectroscopy measurements on symmetrical cells are used to model RSOFC impedance. A RSOFC stack is modeled by electrically linking the individual cells inside a pressurized vessel. A phase change heat store is added to improve energy storage efficiency. The model is implemented in MATLAB®/Simulink®. Two competing inverter control schemes are compared, trading off DC bus ripple against AC power quality. It is found that selection of appropriate DC bus capacitance is important in certain scenarios, with potential system cost implications. It is shown that the system can store electrical energy at an efficiency of 64% over a single discharge–charge cycle, i.e., hydrogen to electricity and heat to hydrogen.
Young Children's Imitative and Innovative Behaviour on the Floating Object Task
Authors: Nielsen Mark
Published: July 2012

Past research has shown that children will copy the actions of adults with high fidelity, even actions that are obviously causally irrelevant to the modelled outcome. However, this phenomenon has always been documented in cases where a clear functional outcome has been brought about (e.g. getting a box open to retrieve a toy). Here, we demonstrate how young children will continue to adopt the precise actions shown to them by an adult even if the goal of the actions is not realized during modelling. A group of 4‐year‐old participants were presented with a toy lying at the bottom of a Perspex tube. Despite the availability of a bottle of water, and unlike the responses of a group of adults, few children spontaneously identified the solution of pouring the water into the tube to raise the toy up the tube where it could be reached. The majority did so, however, after seeing an adult demonstrate this approach. Critically, children copied the specific method of the adult, even when this involved the unnecessary steps of pouring from the bottle into a cup before pouring from the cup into the tube. These results highlight the value of overimitation to children growing up in a world filled with objects whose operating mechanisms are often hidden or unclear. Copyright © 2012 John Wiley & Sons, Ltd.
THE IMPORTANCE OF SAP FLOW MEASUREMENTS TO ESTIMATE ACTUAL WATER USE OF MESKI OLIVE TREES UNDER DIFFERENT IRRIGATION REGIMES IN TUNISIA
Authors: Vandegehuchte Maurits W. , Braham Mohamed , Lemeur Raoul , Steppe Kathy
Published: July 2012

Improvement in irrigation techniques has led to an expansion of the irrigated olive area in Tunisia and consequently a rise in agricultural water consumption. Here, the actual water use of Olea europaea L. ‘Meski’ as estimated by thermal dissipation probe measurements was compared for different irrigation regimes: three plots with irrigation doses based on Penman–Monteith crop evapotranspiration (ETc), 0.33 × ETc and the local grower's experience (about 0.6 × ETc), respectively. The scaling up of sap flux densities proved to be difficult given the azimuthal and radial sap flux density variability and the conductive surface area asymmetry. Moreover, natural thermal gradients may lead to inaccurate use of standard sap flow formulas. Depending on the manner of upscaling, differences in water use of more than 50 l day‐1 per tree were obtained (up to 0.7 × ETc irrigation dose). Despite these difficulties, sap flow calculations seem crucial to accurately determine the water needs of the orchard under investigation, as they corresponded closely to the lowest irrigation dose which was considered sufficiently high as no significant differences in drought stress variables were detected between the plots. Therefore, irrigation based solely on ETc leads to wasting of water; hence, careful application of both meteorological and sap flow methods is desirable in irrigation scheduling. Copyright © 2012 John Wiley & Sons, Ltd.
Toxic interaction between acid yellow 23 and trypsin: Spectroscopic methods coupled with molecular docking
Authors: Wang Jing , Liu Rutao , Qin Pengfei
Published: July 2012

Acid yellow 23 (AY23) is a pervasive azo dye used in many fields which is potentially harmful to the environment and human health. This paper studied the toxic effects of AY23 on trypsin by spectroscopic and molecular docking methods. The addition of AY23 effectively quenched the intrinsic fluorescence of trypsin via static quenching with association constants of K290,K = 3.67 × 105 L mol−1 and K310,K = 1.83 × 105 L mol−1. The calculated thermodynamic parameters conformed that AY23 binds to trypsin predominantly via electrostatic forces with one binding site. Conformational investigations indicated the skeletal structure of trypsin unfolded and the microenvironment of tryptophan changed with the addition of AY23. Molecular docking study showed that AY23 interacted with the His 57 and Lys 224 residue of trypsin and led to the inhibition of enzyme activity. This study offers a more comprehensive picture of AY23–trypsin interaction and indicates their interaction may perform toxic effects within the organism. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:360–367, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21430
Attenuation of cellular antioxidant defense mechanisms in kidney of rats intoxicated with carbofuran
Authors: Kaur Bhupindervir , Khera Alka , Sandhir Rajat
Published: July 2012

Carbofuran, an anticholinestrase carbamate, is commonly used as an insecticide. Its toxic effect on kidney is less established. The present study was designed to investigate the effect of carbofuran on kidneys and to understand the mechanism involved in its nephrotoxicity. Male Wistar rats were divided into two groups of eight animals each; control animals received sunflower oil (vehicle) and carbofuran exposed animals were treated with carbofuran (1 mg/kg body weight) orally for 28 days. At the end of the treatment, significant increase was observed in urea and creatinine levels in serum along with the inhibition of acetylcholinesterase, suggesting nephrotoxicity. The antioxidant defense system of animals treated with carbofuran was altered in terms of increased lipid peroxidation, reduced glutathione, and total thiols and decreased activity of antioxidant enzymes (superoxide dismutase and catalase). The results indicate that carbofuran is nephrotoxic and increased oxidative stress appears to be involved in its nephrotoxic effects. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:393–398, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21433
DO EMERGING DONORS ALLOCATE AID AS DAC MEMBERS DO? THE CASE OF KOREA IN THE MILLENNIUM ERA
Authors: Lee Kye Woo
Published: July 2012

This study estimates the responsiveness of Korean aid to recipient countries' socio‐economic development needs and the strategic and commercial interests of Korea, with implications for other emerging and Development Assistance Committee (DAC) donors. For this purpose, fixed effects regression models are used for the allocation of aid by the Korea International Cooperation Agency (KOICA) to 157 recipient countries over the period 2004–2008. The results contrast sharply with the trend seen in DAC member countries. KOICA's aid allocations are consistent with neither socio‐economic development and poverty‐reduction objectives of aid, nor much of the strategic and commercial interests of Korea. Copyright © 2012 John Wiley & Sons, Ltd.
Transcriptional profiles underlying vulnerability and resilience in rats exposed to an acute unavoidable stress
Authors: Benatti Cristina , Valensisi Cristina , Blom Joan M.C. , Alboni Silvia , Montanari Claudia , Ferrari Francesco , Tagliafico Enrico , Mendlewicz Julien , Brunello Nicoletta , Tascedda Fabio
Published: July 2012

A complex interplay between gene and environment influences the vulnerability or the resilience to stressful events. In the acute escape deficit (AED) paradigm, rats exposed to an acute unavoidable stress (AUS) develop impaired reactivity to noxious stimuli. Here we assessed the behavioral and molecular changes in rats exposed to AUS. A genome‐wide microarray experiment generated a comprehensive picture of changes in gene expression in the hippocampus and the frontal cortex of animals exposed or not to AUS. Exposure to AUS resulted in two distinct groups of rats with opposite behavioral profiles: one developing an AED, called “stress vulnerable,” and one that did not develop an AED, called “stress resilient.” Genome‐wide profiling revealed a low percentage of overlapping mechanisms in the two areas, suggesting that, in the presence of stress, resilience or vulnerability to AUS is sustained by specific changes in gene expression that can either buffer or promote the behavioral and molecular adverse consequences of stress. Specifically, we observed in the frontal cortex a downregulation of the transcript coding for interferon‐β and leukemia inhibitory factor in resilient rats and an upregulation of neuroendocrine related genes, growth hormone and prolactin, in vulnerable rats. In the hippocampus, the muscarinic M2 receptor was downregulated in vulnerable but upregulated in resilient rats. Our findings demonstrate that opposite behavioral responses did not correspond to opposite regulatory changes of the same genes, but resilience rather than vulnerability to stress was associated with specific changes, with little overlap, in the expression of patterns of genes. © Wiley Periodicals, Inc.
The vibrations of vitreous silica observed in hyper‐Raman scattering
Authors: Hehlen B. , Simon G.
Published: July 2012

Hyper‐Raman scattering (HRS) is performed in v‐SiO2, and the results are compared to RS and infrared absorption data. Mode analyses are tested based on two models, either the local C2v symmetry of the Si–O–Si bonds or the Td symmetry of the SiO4 tetrahedra. The HRS boson‐peak (BP) signal is dominated by the quasi‐local librations of tetrahedra. However, we find that it also contains a weak dipolar contribution with a different spectral signature, suggesting that the BP modes are not fully hybridized. The transverse optic (TO) modes can be assigned to molecular‐like excitations according to either model, with the exception of the lowest frequency TO4 which involves highly cooperative Si–O–Si motions. On the opposite, the strong scattering from all longitudinal optic (LO) modes clearly follows the average isotropic medium ∞∞m selection rules. This long range cooperativity presumably results from the associated internal electric field. Finally, the strong LO HRS signals enabled observing a new longitudinal component at 1078 cm−1. Through the example of v‐SiO2, the article also highlights new perspectives provided by HRS for the description of the vibrations in disordered materials in general. Copyright © 2012 John Wiley & Sons, Ltd.
Raman tensor analysis of hexagonal polyoxymethylene and its application to study the molecular arrangement in highly crystalline electrospun nanofibers
Authors: Puppulin Leonardo , Kotaki Masaya , Nakamura Morimasa , Iba Daisuke , Moriwaki Ichiro , Pezzotti Giuseppe
Published: July 2012

The orientation dependence in space of Raman‐active vibrations in the hexagonal structure of polyoxymethylene (POM) is discussed in terms of Raman tensor elements as intrinsic physical parameters of the lattice. The variation of polarized intensity for the A1 and the E1 vibrational modes with respect to the POM molecular orientation is systematically studied, from both theoretical and experimental viewpoints, according to the symmetry assignments of each vibrational mode. A set of working equations including the Raman selection rules associated with the A1 and the E1 modes and the orientation distribution function are explicitly formulated and validated by means of a least‐square fitting procedure on experimental data. In addition, an approach based on the introduction of orientation distribution functions is applied to quantitatively assess and compare on a statistical base the molecular orientation of two different types of electrospun POM nanofibers. Copyright © 2012 John Wiley & Sons, Ltd.
Raman spectroscopy in gemmology as seen from a ‘jeweller's’ point of view
Authors: Giarola Marco , Mariotto Gino , Barberio Marianna , Ajò David
Published: July 2012

Some gemstones (diamonds, coloured stones or assembled gems) found in the jewellery commerce, when observed by an optical microscopy or even at naked eye, exhibit unusual characteristics, such as inclusions incorporated at different depths. The investigation by confocal Raman micro‐spectroscopy allowed identification of a blue sapphire and of nanocrystalline anatase in the same surface region of a cut and polished diamond. Moreover, hematite (α‐Fe2O3) inclusions of rectangular shape, embedded at different depths, ranging from a few microns to some tens of microns beneath the gemstone surface, were identified in the coloured stones. Finally, a detailed study of an assembled gem evidenced spectral features that can be put in relation with its fabrication process. Copyright © 2012 John Wiley & Sons, Ltd.
Characterisation and diagnosis of the conservation state of cementitious materials exposed to the open air in XIX century lighthouses located on the coast of the Basque Country: ‘The case of Igueldo lighthouse, San Sebastian, North of Spain’
Authors: Morillas Héctor , Maguregui Maite , Gómez‐Laserna Olivia , Trebolazabala Josu , Madariaga Juan Manuel
Published: July 2012

Non‐invasive Raman spectroscopy for molecular analysis, assisted with other analytical techniques such as X‐ray fluorescence for elemental analysis were applied to characterise possible pathologies on cement mortar and concrete (cementitious materials) from a historical 19th century lighthouse exposed to the open air, in Igueldo (San Sebastian, Basque Country, North of Spain). The spectroscopic observations were compared with quantitative concentration values of cations and anions extracted as soluble salts, treated by chemometric tools. The integrated analytical techniques were used to diagnose the influence of (1) marine aerosol, (2) seagull droppings and (3) original addition of sulphates to the cementitious materials, on the formation of decaying products such as chlorides, sulphates, nitrates, etc., that affect the integrity of the lighthouse outdoor area. Copyright © 2012 John Wiley & Sons, Ltd.
Templated syntheses of Pt thin films with feature sizes of 3, 6 and 9 nm and their effects on SERS
Authors: Lee Ki‐Rim , Kim Min‐Hye , Hong Jeung‐Eun , Kwon Young‐Uk
Published: July 2012

We report on the syntheses of nanostructured Pt films with three different feature sizes of 3, 6 and 9 nm and their effects to the surface enhance Raman spectroscopy of rhodamine 6G (Rh6G) analytes. The syntheses of the Pt films have been achieved through templating the pore structures of mesoporous silica thin films (MSTFs). For the purpose of the present study, we synthesized three MSTFs with pore sizes 3, 6 and 9 nm. Other than the pore sizes, the silica thin films have the same pore structures. The Pt films have been synthesized by depositing Pt into the pores of the template MSTFs and removing the templates after the deposition. The Pt films produce strong Raman spectra of Rh6G with the intensity increasing as the feature size of the Pt film increases. Simulations of the induced electromagnetic fields on the Pt films show the same trend as the observed Raman intensity with the feature size. Copyright © 2012 John Wiley & Sons, Ltd.
Enhanced Fröhlich interaction of semiconductor cuprous oxide films determined by temperature‐dependent Raman scattering and spectral transmittance
Authors: Yu Wenlei , Han Meijie , Jiang Kai , Duan Zhihua , Li Yawei , Hu Zhigao , Chu Junhao
Published: July 2012

Anomalous low temperature behaviors in cuprous oxide (Cu2O) film grown on quartz substrate have been investigated by temperature‐dependent Raman and transmittance spectra. The longitudinal optical components of two Γ15‐ phonon modes become sharper and more intense at a low temperature. It can be found that the highest‐order electronic transition located at 6.4 eV exhibits a minimum transmittance near 200 K. Correspondingly, the variations from phonon intensity ratios reveal obvious anomalies with the decreasing temperature, indicating the existence of strong electron–phonon coupling mediated by Fröhlich interaction in the Cu2O films below the temperature of 200 K. Copyright © 2012 John Wiley & Sons, Ltd.
On‐and off‐site Raman study of rock‐shelter paintings at world‐heritage site of Bhimbetka
Authors: Ravindran T. R. , Arora A. K. , Singh M. , Ota S. B.
Published: July 2012

Rock‐shelter paintings of Bhimbetka world‐heritage site near Bhopal, India have been investigated using a portable Raman spectrometer. These paintings in the rock shelters belong to periods starting from pre‐historic to the 19th century AD (Gond period). In addition, tiny fragments of pigments (100–200 µm in size) extracted from some of the artworks were also studied in laboratory using a micro‐Raman spectrometer and analyzed using energy‐dispersive X‐ray analysis for elemental composition. Based on the Raman spectra and the elemental analysis mineral‐based pigments such as calcite, gypsum, hematite, whewellite, and goethite could be identified. A comparison of the spectra recorded on‐site using a light‐weight portable spectrometer with those using laboratory equipment is also made and discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Multiple liquid chromatography separations and nanoESI‐ion trap detection of plasma proteins in search of stroke biomarkers: A pilot study
Authors: Kodali Phanichand , Jurkevica Agnese , Landero Julio , Kuhlmann Christopher , Caruso Joseph , Adeoye Opeolu
Published: July 2012

Stroke is the most common cause of morbidity and death in the Western world, following ischemic heart disease and cancer. Stroke can be of two types, ischemic or hemorrhagic, with ischemic stroke accounting for approximately 85% of the total number of strokes. Well‐recognized environmental risk factors for stroke include hypertension, smoking, diabetes mellitus, atrial fibrillation, and atherosclerosis. Computed tomography (CT) scanning is used to diagnose hemorrhagic stroke but is relatively ineffective and may remain normal in patients with mild ischemic strokes. Magnetic Resonance Imaging (MRI) is more sensitive in detecting ischemia than CT, especially in the diagnosis of mild stroke but it is still not 100% sensitive or precise. A simple and low‐cost, rapid blood test to confirm a clinical and imaging diagnosis of ischemic stroke would be extremely useful. Based on this, the central idea of this paper is to develop a method that would be applicable to a statistically viable sample set to provide candidate biomarkers for distinguishing stroke types. In search of these candidate biomarkers, different analytical separation techniques have been used to screen for major differences in the proteomes of patients plasma samples with proteomics for identification.
Application of NaClO‐treated multiwalled carbon nanotubes as solid phase extraction sorbents for preconcentration of trace 2,4‐dichlorophenoxyacetic acid in aqueous samples
Authors: Lu Ping , Deng Dayi , Ni Xiaodan
Published: July 2012

Multiwalled carbon nanotubes functionalized by oxidation of original multiwalled carbon nanotubes with NaClO were prepared and their application as solid phase extraction sorbent for 2,4‐dichlorophenoxyacetic acid (2,4‐D) was investigated systemically, and a new method was developed for the determination of trace 2,4‐D in water samples based on extraction and preconcentration of 2,4‐D with solid phase extraction columns packed with NaClO‐treated multiwalled carbon nanotubes prior to its determination by HPLC. The optimum experimental parameters for preconcentration of 2,4‐D, including the column activating conditions, the amount of the sorbent, pH of the sample, elution composition, and elution volume, were investigated. The results indicated 2,4‐D could be quantitatively retained by 100 mg NaClO‐treated multiwalled carbon nanotubes at pH 5, and then eluted completely with 10 mL 3:1 (v/v) methanol‐ammonium acetate solution (0.3 mol/L). The detection limit of this method for 2,4‐D was 0.15 μg/L, and the relative standard deviation was 2.3% for fortified tap water samples and 2.5% for fortified riverine water sample at the 10 μg/L level. The method was validated using fortified tap water and riverine water samples with known amount of 2,4‐D at the 0.4, 10, and 30 μg/L levels, respectively.
Roadway mortality of barn owls in Idaho, USA
Authors: Boves Than J. , Belthoff James R.
Published: July 2012

We examined the temporal, spatial, and demographic factors that influenced roadway mortality of barn owls (Tyto alba) along a 248‐km stretch of Interstate 84 in southern Idaho using systematic road surveys. Counts of dead animals from surveys can be underestimated because of sampling biases; therefore, we also conducted experiments to assess the effects of search and removal bias on the estimates of roadway mortality of owls. We conducted surveys every 2 weeks over a 2‐year period and detected 812 dead barn owls (unadjusted mortality rate of 1.64 owls/km/yr). After adjusting this estimate for search and removal bias, we documented mortality rates of up to 5.99 owls/km/year. Owl mortality was not random in relation to sex, age class, or location along the highway. Females and juveniles, which represent individuals more likely to disperse long distances, were killed more frequently than males and adults. During the nonbreeding season, owls were killed more often near agricultural lands than in shrub‐steppe, but this pattern was not apparent during the breeding season. Owls were also killed more often on portions of the roadway closer to the Snake River canyon, perhaps because of the availability of nest and roost sites. Mortality rates differed markedly between the 2 years of study, which could have been related to variability in weather and its subsequent effect on owl productivity. Our data suggest that barn owls in this region may not persist under this level of mortality without significant immigration or management. Thus, roadway management to reduce or prevent owl use of roadways, reduce rodent populations near major roads, alert motorists to the presence of owls, or otherwise reduce the chances that vehicles and owls collide would improve barn owl survival and population persistence. © 2012 The Wildlife Society.
Synthesis of Amphiphilic Poly(ethylene oxide‐co‐glycidol)‐graft‐polyacrylonitrile Brush Copolymers and their Self‐assembly in Aqueous Media
Authors: Sui Kunyan , Liang Hongchao , Zhao Xin , Ma Yingying , Zhang Yang , Xia Yanzhi
Published: July 2012

An amphiphilic copolymer brush poly(ethylene oxide‐co‐glycidol)‐graft‐polyacrylonitrile [poly(EO‐co‐Gly)‐g‐PAN], is successfully prepared for the first time by a combination of anionic polymerization and redox free radical polymerization. The final products and intermediates are characterized by NMR and GPC. Aggregates made from the brush copolymers, poly(EO‐co‐Gly)‐g‐PAN, with a long hydrophobic graft length in water are studied by TEM and DLS. The effects of hydrophobic graft length and water content on the morphologies are discussed. Some rare morphologies of aggregates are observed, such as lamellae, bicontinuous networks, bowls or nanosheets, and large compound rods with a brittleness that can be ascribed to the orientation of high content semi‐crystalline PAN segments.