bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Composite Quadrature Rule
Authors: Sun Weiwei , Zhang Qian
Published: June 2013

We present a new composite quadrature rule which is exact for polynomials of degree 2N+K– 1 withNabscissas at each subinterval andKboundary conditions. The corresponding orthogonal polynomials are introduced and the analytic formulae for abscissas and weight functions are presented. Numerical results show that the new quadrature rule is more efficient, compared with classical ones.
A Method of Lines Based on Immersed Finite Elements for Parabolic Moving Interface Problems
Authors: Lin Tao , Lin Yanping , Zhang Xu
Published: June 2013

This article extends the finite element method of lines to a parabolic initial boundary value problem whose diffusion coefficient is discontinuous across an interface that changes with respect to time. The method presented here uses immersed finite element (IFE) functions for the discretization in spatial variables that can be carried out over a fixed mesh (such as a Cartesian mesh if desired), and this feature makes it possible to reduce the parabolic equation to a system of ordinary differential equations (ODE) through the usual semi-discretization procedure. Therefore, with a suitable choice of the ODE solver, this method can reliably and efficiently solve a parabolic moving interface problem over a fixed structured (Cartesian) mesh. Numerical examples are presented to demonstrate features of this new method.
Monetary versus Non-Monetary Pro-Poor Growth: Evidence from Rural Ethiopia between 2004 and 2009
Authors: Ben Haj Kacem Rami
Published: June 2013

The aim of this paper is to contribute to the debate on the pro-poor growth measurement techniques using monetary versus non-monetary indicators. In this context, an alternative method for introducing non-monetary indicators into monetary pro-poor growth analysis is presented. The method is based on the definition of a “Conditional Growth Incidence Curve” for each group of households with a common selected non-monetary characteristic. Additional information provided by the “Conditional Growth Incidence Curve” is useful for a more detailed pro-poor growth analysis. Empirical illustration using data from rural Ethiopia between 2004 and 2009 shows the utility and the limits of each measurement technique.
Organizational Form as a Source of Systemic Risk
Authors: Bholat David , Gray Joanna
Published: June 2013

“Systemic risk” now occupies centre stage in discussions of bank regulatory reform. Systemic risk is often seen as a problem of size, operational complexity, interconnectivity and contagion. It is less often discussed in terms of the institutional framework of legal rules and principles within which financial intermediation takes place, and the organizational culture promoted by those structures. In this article we redress this deficit through an appraisal of Northern Rock, illustrating the consequences of its transformation from mutually owned building society to publicly held company on organisational culture. These changes had profound effects on the incentive structure of its owners and managers, as profit-maximisation and shareholder value became the driving force within the firm, as in much of the rest of the UK banking sector. Thus, in addition to grappling with risk and uncertainty—and taking care to distinguish between the two—current efforts to construct a new macro-prudential regulatory paradigm should recognise the importance of Frank Knight’s third key conceptual category–profit. Furthermore, in seeking to understand systemic risk, it becomes necessary to delve into micro-legal concepts such as property, trust, and contract that govern different forms of business to discern whether or not some modes of financial association create a greater degree of systemic risk than others. This is especially so when one organizational model comes to dominate retail markets, as did the publicly held company in the UK banking sector at the turn of the twenty-first century.
The simulations of sulfuric acid concentration and new particle formation in an urban atmosphere in China
Authors: Wang Z. B. , Hu M. , Mogensen D. , Yue D. L. , Zheng J. , Zhang R. Y. , Liu Y. , Yuan B. , Li X. , Shao M. , Zhou L. , Wu Z. J. , Wiedensohler A. , Boy M.
Published: June 2013

Abstract. Simulations of sulfuric acid concentration and new particle formation are performed by using the zero-dimensional version of the model MALTE (Model to predict new Aerosol formation in the Lower TropospherE) and measurements from the Campaign of Air Quality Research in Beijing and Surrounding areas (CAREBeijing) in 2008. Chemical reactions from the Master Chemical Mechanism Version 3.2 (MCM v3.2) are used in the model. High correlation (slope = 0.72, R = 0.74) between the modelled and observed sulfuric acid concentrations is found during daytime (06:00–18:00). The aerosol dynamics are simulated by the University of Helsinki Multicomponent Aerosol (UHMA) model including several nucleation mechanisms. The results indicate that the model is able to predict the on- and offset of new particle formation in an urban atmosphere in China. In addition, the number concentrations of newly formed particles in kinetic-type nucleation including homogenous homomolecular (J=K[H2SO4]2) and homogenous heteromolecular nucleation involving organic vapours (J=Khet[H2SO4][Org]) are in satisfactory agreement with the observations. However, the specific organic compounds possibly participate in the nucleation process should be investigated in further studies.
Determining spatial variability of dry spells: a Markov-based method, applied to the Makanya catchment, Tanzania
Authors: Fischer B. M. C. , Mul M. L. , Savenije H. H. G.
Published: June 2013

Abstract. With a growing world population and a trend towards more resource-intensive diets, pressure on land and water resources for food production will continue to increase in the coming decades. Large parts of the world rely on rainfed agriculture for their food security. In Africa, 90% of the food production is from rainfed agriculture, generally with low yields and a high risk of crop failure. One of the main reasons for crop failure is the occurrence of dry spells during the growing season. Key indicators are the critical dry spell duration and the probability of dry spell occurrence. In this paper a new Markov-based framework is presented to spatially map the length of dry spells for fixed probabilities of non-exceedance. The framework makes use of spatially varying Markov coefficients that are correlated to readily available spatial information such as elevation and distance to the sea. The dry spell map thus obtained is compared to the spatially variable critical dry spell duration, based on soil properties and crop water requirements, to assess the probability of crop failure in different locations. The results show that in the Makanya catchment the length of dry spell occurrence is highly variable in space, even over relatively short distances. In certain areas the probability of crop failure reaches levels that make rainfed agricultural unsustainable, even close to areas where currently rainfed agriculture is successfully being practised. This method can be used to identify regions that are vulnerable to dry spells and, subsequently, to develop strategies for supplementary irrigation or rainwater harvesting.
3-D geomechanical modelling of a gas reservoir in the North German Basin: workflow for model building and calibration
Authors: Fischer K. , Henk A.
Published: June 2013

Abstract. The optimal use of conventional and unconventional hydrocarbon reservoirs depends, amongst others, on the local tectonic stress field. For example, wellbore stability, orientation of hydraulically induced fractures and – especially in fractured reservoirs – permeability anisotropies are controlled by the recent in situ stresses. Faults and lithological changes can lead to stress perturbations and produce local stresses that can significantly deviate from the regional stress field. Geomechanical reservoir models aim for a robust, ideally "pre-drilling" prediction of the local variations in stress magnitude and orientation. This requires a~numerical modelling approach that is capable to incorporate the specific geometry and mechanical properties of the subsurface reservoir. The workflow presented in this paper can be used to build 3-D geomechanical models based on the Finite Element Method (FEM) and ranging from field-scale models to smaller, detailed submodels of individual fault blocks. The approach is successfully applied to an intensively faulted gas reservoir in the North German Basin. The in situ stresses predicted by the geomechanical FE model were calibrated against stress data actually observed, e.g. borehole breakouts and extended leak-off tests. Such a validated model can provide insights into the stress perturbations in the inter-well space and undrilled parts of the reservoir. In addition, the tendency of the existing fault network to slip or dilate in the present-day stress regime can be addressed.
Rereading Comprehension Pedagogies: Toward a Dialogic Teaching Ethic that Honors Student Sensemaking
Authors: Aukerman Maren
Published: June 2013

This conceptual essay critiques reading comprehension pedagogies that are part of the current educational landscape.  I argue that comprehension pedagogy generally reflects one of three differing orientations, each with its own assumptions about what comprehension is:  comprehension-as-outcome pedagogies, which emphasize getting textual meaning “right”; comprehension-as-procedure pedagogies, which emphasize knowing the “right” ways doing reading; and comprehension-as-sensemaking pedagogies, which take all textual interpretation seriously, regardless of “rightness.”  Comprehension-as-sensemaking pedagogies, in turn, can be distinguished as either primarily responsive – aimed at surfacing student understandings – or primarily dialogic – aimed at getting student understandings to refract.  Arguably, comprehension-as-outcome pedagogy dominates current reading instruction.  A focus on measuring and teaching toward “right” interpretations permeates almost all aspects of comprehension pedagogy even when one of the other orientations toward comprehension pedagogy is also at play.  While seemingly intuitive, this overarching outcome emphasis reifies textual meaning in ways that are both theoretically and ethically problematic.  I make the case that comprehension-as-sensemaking pedagogy should become primary instead.  I propose that comprehension-as-outcome and comprehension-as-procedure pedagogies should not be abandoned, but should be subordinated to dialogic comprehension-as-sensemaking pedagogy so that students’ textual sensemaking is more fully heard, respected, and examined in reading classrooms.
Robotic Radiosurgery for the Treatment of 1–3 Brain Metastases: A Pragmatic Application of Cost-Benefit Analysis Using Willingness-To-Pay
Authors: Greenspoon Jeffrey Noah , Whitton Anthony , Whelan Timothy , Sharieff Waseem , Wright James , Sussman Jonathan , Gafni Amiram
Published: June 2013

With the emergence of radiosurgery as a new radiotherapeutic technique, health care decision makers are required to incorporate community need, cost and patient preferences when allocating radiosurgery resources. Conventional patient utility measures would not reflect short term preferences and would therefore not inform decision makers when allocating radiosurgery treatment units. The goal of this article is to demonstrate the feasibility of cost-benefit analysis to elicit the yearly net monetary benefit of robotic radiosurgery. To calculate the yearly incremental cost of robotic radiosurgery as compared to fixed gantry radiosurgery we used direct local cost data. We assumed a standard 10 year replacement and 5% amortization rate. Decision boards summarizing the clinical scenario of brain metastases and the difference between robotic and fixed gantry radiosurgery in terms of immobilization, comfort and treatment time were then presented to a sample of 18 participants. Participants who preferred robotic radiosurgery were randomly assigned to either a low ($1) or high ($5) starting point taxation based willingness-to-pay algorithm. The yearly incremental cost of providing robotic radiosurgery was $99,177 CAD. The mean community yearly willingness-to-pay for robotic radiosurgery was $2,300,000 CAD, ρ = 0.03. The calculated yearly net societal benefit for robotic radiosurgery was $2,200,823 CAD. Among participants who preferred robotic radiosurgery there was no evidence of starting point bias, ρ = 0.8. We have shown through this pilot study that it is feasible to perform cost-benefit analysis to evaluate new technologies in Radiation Oncology. Cost-benefit analysis offers an analytic method to evaluate local preferences and provide accountability when allocating limited healthcare resources.
Optical Biopsy of Benign and Malignant Tissue by Time Resolved Spectroscopy
Authors: Masilamani V. , Das B. B. , Secor J. , AlSalhi M. , Devanesan S. , Prasad S. , Rabah D. , Alfano R. R.
Published: June 2013

Pathological condition of malignant tissue could be analyzed by spectral domain or time domain spectroscopy, the two being the complementary to each other in optical biopsy (OB) of cancer. This paper reports results of time resolved emission spectroscopy (TRS) of 24 excised tissue samples of breast and prostate (normal control = 12; benign = 4; malignant = 8), employing a 390 nm, 100 fs, Ti-Sapphire laser pulses. The fluorescence decay times were measured using streak camera and the resultant data were fitted for single and bi-exponential decays with reliability of 97%. Our results show the distinct difference between normal, benign and malignant tissues mostly due to the emission spectra of Nicotinamide Adenine Dinucleotide (NADH), Flavin Mononucleotide (FAD) and also due to the heterogeneity of micro environments associated with the diseased tissues. In this short report, fit is also shown that TRS of breast tissues are similar to those of prostate tissues.
Validation of Automatic Contour Propagation for 4D Treatment Planning Using Multiple Metrics
Authors: Peroni M. , Spadea M. F. , Riboldi M. , Falcone S. , Vaccaro C. , Sharp G. C. , Baroni G.
Published: June 2013

The aim of this work is to provide insights into multiple metrics clinical validation of deformable image registration and contour propagation methods in 4D lung radiotherapy planning. The following indices were analyzed and compared: Volume Difference (VD), Dice Similarity Coefficient (DSC), Positive Predictive Value (PPV) and Surface Distances (SD). The analysis was performed on three patient datasets, using as reference a ground-truth volume generated by means of Simultaneous Truth And Performance Level Estimation (STAPLE) algorithm from the outlines of five experts. Significant discrepancies in the quality assessment provided by the different metrics in all the examined cases were found. Metrics sensitivity was more evident in presence of image artifacts and particularly for tubular anatomical structures, such as esophagus or spinal cord. Volume Differences did not account for position and DSC exhibited criticalities due to its intrinsic symmetry ( i.e. over- and under-estimation of the reference contours cannot be discriminated) and dependency on the total volume of the structure. PPV analysis showed more robust performance, as each voxel concurs to the classification of the propagation, but was not able to detect inclusion of propagated and ground-truth volumes. Mesh distances could interpret the actual shape of the structures, but might report higher mismatches in case of large local differences in the contour surfaces. According to our study, the combination of VD and SD for the validation of contour propagation algorithms in 4D could provide the necessary failure detection accuracy.
Radiotherapy for Esophageal Cancer Using Simultaneous Integrated Boost Techniques: Dosimetric Comparison of Helical TomoTherapy, Volumetric-Modulated Arc Therapy (RapidArc) and Dynamic Intensity-Modulated Radiotherapy
Authors: Wang Yao-Ching , Chen Shang-Wen , Chien Chun-Ru , Hsieh Te-Chun , Yu Chun-Yen , Kuo Yu-Cheng , Yang Shih-Neng , Kao Chia-Hung , Liang Ji-An
Published: June 2013

This study compared TomoTherapy (TM), with Volumetric-Modulated Arc Therapy (RapidArc, RA), and dynamic intensity-modulated radiotherapy (dIMRT) for locally advanced esophageal cancer (LAEC) with a simultaneous integrated boost (SIB) technique with regard to the target coverage and sparing of organs at risk (OARs). Twelve patients receiving four-dimensional computed tomography simulation were enrolled for dosimetric comparison. Gross tumor volume was contoured with the maximum intensity projection method. Using an SIB method, Planning target volume low (PTVL) and planning target volume high (PTVH) were prescribed as 54 Gy and 60 Gy, respectively, each administered in 30 fractions. We compared the results of statistical analysis for target coverage, homogeneity index (HI) and conformity index (CI) of PTVs, parameters of OARs and monitor unit (MU) were compared for analysis. The HI for PTVH varied significantly for the 3 techniques of TM, RA, and dIMRT (4.38 ± 0.86, 6.40 ± 0.86, and 6.11 ± 0.68, respectively; P < 0.001). The CI scores for PTVH also differed across TM, RA, and dIMRT (0.64 ± 0.06, 0.53 ± 0.06, and 0.59 ± 0.05, respectively; P < 0.001). The HI for PTVL showed a significant difference among TM, RA, and dIMRT (15.44 ± 0.88, 20.88 ± 1.03 and 18.65 ± 1.42, respectively; P < 0.001). The percentage of lung volume receiving 5 Gy (V5) and 20 Gy (V20) (for V5: TM 54.4 ± 8.0%; RA 67.5 ± 14.5%, P <0.01; dIMRT 44.8 ± 8.2%; for V20: 13.6 ± 3.3%, 12.2 ± 3.6%, 18.1 ± 3.4%, P = 0.001, respectively). For RA, the lung V5 ≥ 65% was observed in 6 patients and the V10 ≥ 50 % in one patient. TM, RA and dIMRT provided comparable coverage of the target and sparing of OARs. TM demonstrated superior CI and HI for tumor coverage and lowered the specified dose parameters for lung. RA provided an advantage in terms of the lowest MU and V20 of the lung, but its higher lung V5 was of some concern about lung toxicity.
An Introduction to Sequence Similarity (“Homology”) Searching
Authors: Pearson William R.
Published: June 2013

Sequence similarity searching, typically with BLAST, is the most widely used and most reliable strategy for characterizing newly determined sequences. Sequence similarity searches can identify “homologous” proteins or genes by detecting excess similarity— statistically significant similarity that reflects common ancestry. This unit provides an overview of the inference of homology from significant similarity, and introduces other units in this chapter that provide more details on effective strategies for identifying homologs. Curr. Protoc. Bioinform. 42:3.1.1‐3.1.8. © 2013 by John Wiley & Sons, Inc.
Fully Plastic Dye Solar Cell Devices by Low‐Temperature UV‐Irradiation of both the Mesoporous TiO2 Photo‐ and Platinized Counter‐Electrodes
Authors: Zardetto Valerio , Di Giacomo Francesco , Garcia‐Alonso Diana , Keuning Wytze , Creatore Mariadriana , Mazzuca Claudia , Reale Andrea , Di Carlo Aldo , Brown Thomas M.
Published: June 2013

The application of UV irradiation processes are successfully proposed for the first time in the fabrication of both of the two plastic electrodes in flexible dye solar cells (DSCs) and modules. For the realization of the photo‐electrode, a customized TiO2 paste formulation and UV processing method was developed which yields 134% (48%) performance enhancement with respect to the same (binder‐free) paste treated at 120 °C. UV treatment induces both complete removal of organic media and more efficient charge collection. Significantly, highly catalytic platinized flexible counter‐electrodes are also obtained via UV photo‐induced reduction of screen‐printed platinum precursor pastes based on hexachloroplatinic acid. Using both UV‐processed electrodes, a fully plastic DSC is fabricated with a conversion efficiency of 4.3% under 1 Sun (semitransparent) and 5.3% under 0.2 Sun (opaque). Performance is within 10% of the efficiency of a glass‐based DSC prepared with the same materials but with conventional high temperature processes. The material formulations and processes are simple, and easily up‐scaled over large areas, even directly and simultaneously applicable to the preparation of both the photo‐and counter‐electrode on the same substrate which enabled us to demonstrate the first module on plastic realized with a W series interconnection.
Safety of intravenous thrombolysis for ischemic stroke in patients treated with warfarin
Authors: Mazya Michael V. , Lees Kennedy R. , Markus Romesh , Roine Risto O. , Seet Raymond C. S. , Wahlgren Nils , Ahmed Niaz ,   Safe Implementation of Thrombolysis in Stroke Investigators
Published: June 2013

Objective

Controversy surrounds the safety of intravenous (IV) tissue plasminogen activator (tPA) in ischemic stroke patients treated with warfarin. The European tPA license precludes its use in anticoagulated patients altogether. American guidelines accept IV tPA use with an international normalized ratio (INR) ≤ 1.7. The influence of warfarin on symptomatic intracerebral hemorrhage (SICH), arterial recanalization, and long‐term functional outcome in stroke thrombolysis remains unclear.

Methods

We analyzed data from 45,074 patients treated with IV tPA enrolled in the Safe Implementation of Thrombolysis in Stroke (SITS) International Stroke Thrombolysis Register. A total of 768 patients had baseline warfarin treatment with INR ≤ 1.7. Outcome measures were SICH, arterial recanalization, mortality, and functional independence at 3 months.

Results

Patients on warfarin with INR ≤ 1.7 were older, had more comorbidities, and had more severe strokes compared to patients without warfarin. There were no significant differences between patients with and without warfarin in SICH rates (adjusted odds ratio [aOR] = 1.23, 95% confidence interval [CI] = 0.72–2.11 per SITS‐MOST; aOR = 1.26, 95% CI = 0.82–1.70 per European Cooperative Acute Stroke Study II) after adjustment for age, stroke severity, and comorbidities. Neither did warfarin independently influence mortality (aOR = 1.05, 95% CI = 0.83–1.35) or functional independence at 3 months (aOR = 1.01, 95% CI = 0.81–1.24). Arterial recanalization by computed tomography/magnetic resonance angiography trended higher in warfarin patients (62% [37 of 59] vs 55% [776/1,475], p = 0.066). Recanalization approximated by disappearance at 22 to 36 hours of a baseline hyperdense middle cerebral artery sign was increased (63% [124 of 196] vs 55% [3,901 of 7,099], p = 0.022).

Interpretation

Warfarin treatment with INR ≤ 1.7 did not increase the risk for SICH or death, and had no impact on long‐term functional outcome in patients treated with IV tPA for acute ischemic stroke. Ann Neurol 2013;74:266–274
Confounding underlies the apparent month of birth effect in multiple sclerosis
Authors: Fiddes Barnaby , Wason James , Kemppinen Anu , Ban Maria , Compston Alastair , Sawcer Stephen
Published: June 2013

Objective

Several groups have reported apparent association between month of birth and multiple sclerosis. We sought to test the extent to which such studies might be confounded by extraneous variables such as year and place of birth.

Methods

Using national birth statistics from 2 continents, we assessed the evidence for seasonal variations in birth rate and tested the extent to which these are subject to regional and temporal variation. We then established the age and regional origin distribution for a typical multiple sclerosis case collection and determined the false‐positive rate expected when comparing such a collection with birth rates estimated by averaging population‐specific national statistics.

Results

We confirm that seasonality in birth rate is ubiquitous and subject to highly significant regional and temporal variations. In the context of this variation we show that birth rates observed in typical case collections are highly likely to deviate significantly from those obtained by the simple unweighted averaging of national statistics. The significant correlations between birth rates and both place (latitude) and time (year of birth) that characterize the general population indicate that the apparent seasonal patterns for month of birth suggested to be specific for multiple sclerosis (increased in the spring and reduced in the winter) are expected by chance alone.

Interpretation

In the absence of adequate control for confounding factors, such as year and place of birth, our analyses indicate that the previous claims for association of multiple sclerosis with month of birth are probably false positives. ANN NEUROL 2013;73:714–720
Ion‐Transfer Electrochemistry of Rat Amylin at the Water–Organogel Microinterface Array and Its Selective Detection in a Protein Mixture
Authors: Alvarez de Eulate Eva , O'Sullivan Shane , Fletcher Sharon , Newsholme Philip , Arrigan Damien W. M.
Published: June 2013

The behavior of proteins and polypeptides at electrified aqueous–organic interfaces is of benefit in label‐free detection strategies. In this work, rat amylin (or islet amyloid polypeptide) was studied at the interface formed between aqueous liquid and gelled organic phases. Amylin is a polypeptide that is co‐secreted with insulin from islet beta‐cells and is implicated in fibril formation. In this study, rat amylin was used, which does not undergo aggregation. The polypeptide underwent an interfacial transfer process, from water to the gelled organic phase, under applied potential stimulation. Cyclic voltammetry revealed steady‐state forward and peak‐shaped reverse voltammograms, which were consistent with diffusion‐controlled water‐to‐organic transfer and thin‐film stripping or desorptive back‐transfer. The diffusion‐controlled forward current was greater when amylin was present in an acidic aqueous phase than when it was present in an aqueous phase at physiological pH; this reflects the greater charge on the polypeptide under acidic conditions. The amylin transfer current was concentration dependent over the range 2–10 μM, at both acidic and physiological pH. At physiological pH, amylin was selectively detected in the presence of a protein mixture, which illustrated the bioanalytical possibilities for this electrochemical behavior.
Isolation and enzymatic properties of a nonspecific acid phosphatase from Vigna aconitifolia seeds
Authors: Anand Asha , Srivastava Pramod Kumar
Published: June 2013

Acid phosphatase (EC 3.1.3.2) from Vigna aconitifolia seeds was purified to apparent homogeneity by using ammonium sulfate fractionation and cation‐exchange chromatography [carboxymethyl (CM) cellulose]. The enzyme was 228‐fold purified with 14.6% recovery. Analytical gel filtration chromatography on Sephadex G‐200 column showed that Mr of native enzyme was 58 kDa and denaturing PAGE demonstrated that it was made up of two subunits of 24 and 27 kDa. The enzyme showed its optimum activity at pH 5.0 and 60°C. It exhibited broad substrate specificity and showed a higher specificity constant for para‐nitrophenyl phosphate, Na β‐naphthyl phosphate, and adenosine monophosphate (AMP). Cu2+, Mo6+, Fe3+, phosphate, and fluoride ions were reported as strong inhibitors for the enzyme. Active site study for the enzyme demonstrated that tryptophan and aspartic acid may be important for the catalysis.
Flow‐injection chemiluminescence determination of gentamicin: optimization by central composite design
Authors: Iranifam M , Hasanzadeh A , Fathinia M , Khataee A R , Mousavi S A
Published: June 2013

A simple and sensitive flow‐injection chemiluminescence (CL) method has been developed for the determination of gentamicin sulfate. The method is based on the inhibitory effect of gentamicin on the CL emission accompanying oxidation of luminol by H2O2 in an alkaline medium in the presence of Cu(II) as a catalyst. Inhibition was caused by the formation of a strong complex between analyte and the catalyst. Experimental variables, including the concentrations of luminol (µmol/L), H2O2 (mol/L), Cu(II) (mol/L) and NaOH (mol/L), were optimized using a central composite design. Under optimum conditions, the plot of CL intensity versus gentamicin concentration was found to have two linear ranges. One range was at low concentrations from 1.0 to 10.0 mg/L and the other was from 10.0 to 30.0 mg/L. Precision was calculated by analyzing samples containing 5.0 mg/L gentamicin (n = 11) and the relative standard deviation (RSD) was 1.7%. Also, a high injection throughput of 120 samples/h was achieved. This method was successfully applied to the determination of gentamicin sulfate in pharmaceutical formulations and water samples. Copyright © 2013 John Wiley & Sons, Ltd.
Synchronous fluorescence determination of ferulic acid with Ce(IV) and sodium tripolyphosphate
Authors: Meng F , Liu P , Huang F , Wang L , Wu X , Shen L
Published: June 2013

In this study, a synchronous fluorescence detection method for ferulic acid (FA) is proposed based on a redox reaction between FA and Ce(IV) sulfate in dilute sulfuric acid medium at room temperature. It was found that FA could reduce Ce(IV) to Ce(III) in acidic medium, and sodium tripolyphosphate could further enhance the intrinsic fluorescence of the Ce(III) produced. The enhanced extent of synchronous fluorescence intensity was in proportion to the concentration of FA over the range 3.0 × 10‐8 to 1.0 × 10‐5 mol/L. The corresponding limit of determination (S/N = 3) was 1.3 × 10‐8 mol/L. The proposed method was applied to the determination of sodium ferulate for injection sample with satisfactory results. Copyright © 2013 John Wiley & Sons, Ltd.
Engineering of a hybrid biotransformation system for cytochrome P450sca‐2 inEscherichia coli
Authors: Ba Lina , Li Pan , Zhang Hui , Duan Yan , Lin Zhanglin
Published: June 2013

P450sca‐2 is an industrially important enzyme that stereoselectively converts mevastatin into pravastatin. However, little information or engineering efforts have been reported for this enzyme or its redox partner. In this study, we successfully reconstituted the P450sca‐2 activity inEscherichia coliby co‐expression with putidaredoxin reductase (Pdr) and putidaredoxin (Pdx) from thePseudomonas putidacytochrome P450cam system. With an HPLC‐based screening assay, random mutagenesis was applied to yield a mutant (R8‐5C) with a pravastatin yield of the whole‐cell biotransformation 4.1‐fold that of the wild type. P450sca‐2 wild‐type and R8‐5C were characterized in terms of mevastatin binding and hydroxylation, electron transfer, and circular dichroism spectroscopy. R8‐5C showed an active P450 expression level that was 3.8‐fold that of the wild type, with relatively smaller changes in the apparentkcat/KMwith respect to the substrate mevastatin (1.3‐fold) or Pdx (1.5‐fold) compared with the wild type. Thus, the increase in the pravastatin yield of the whole‐cell biotransformation primarily came from the improved active P450 expression, which has resulted largely from better heme incorporation, although none of the six mutations of R8‐5C are located near the heme active site. These results will facilitate further engineering of this P450sca‐2 system and provide useful clues for improving other hybrid P450 systems.
Removal of SO2 and NOX Using Microwave Swing Adsorption over Activated Carbon Carried Catalyst
Authors: Ma S.‐C. , Yao J. , Ma X. , Gao L. , Guo M.
Published: June 2013

SO2 and NO are the main precursors for acid precipitation. Experimental studies on desulfurization and denitrification were carried out using microwave irradiation over activated carbon carried catalyst. The results show that adsorption capacities and removal efficiencies of activated carbon carried Cu‐based catalyst were higher than Mn‐based or Zn‐based ones. The adsorption capacity of SO2 improved with the increasing moisture in flue gas, but the adsorption capacity of NO had a peak at 6.23 mg g–1 and then began to drop. The desulfurization efficiency increased with O2 content in flue gas, but no noticeable change of denitrification efficiency was observed from the experimental data. The desulfurization efficiency descended with the increase of moisture in flue gas, while the denitrification efficiency augmented earlier and reached a plateau later with the addition of the water steam. In addition, characterization of activated carbon confirmed that the main active component of Cu‐based catalyst is CuO.
High‐Solid‐Content Emulsions of PVC: Scale‐Down of an Industrial Process for Enhanced Understanding of Particle Formation Part 1: Introduction and Scale‐Down
Authors: McKenna T. F. L. , Pascal T. , Lys T.
Published: June 2013

A scale‐down study of an industrial reactor for the production of polyvinyl chloride (PVC) via an emulsion polymerization process was carried out in order to understand the source of batch‐to‐batch variations in product quality. In Part 1, an analysis of the plant is presented and the industrial recipe scaled down to a pilot‐scale reactor. In the following Parts 2 and 3 a systematic analysis of the main process parameters revealed that particle generation and stabilization actually occurred in a manner slightly different from what was thought at the production site.
High‐Solid‐Content Emulsions of PVC: Scale‐Down of an Industrial Process for Enhanced Understanding of Particle Formation Part 3: Production of Bimodal Latexes
Authors: McKenna T. F. L. , Pascal T. , Lys T.
Published: June 2013

A scale‐down study of an industrial reactor for the production of polyvinyl chloride (PVC) via an emulsion polymerization process was carried out in order to understand the cause of batch‐to‐batch variations in product quality. The results in Part 2 of this series of papers indicated that a large excess of base is required to control the particle size distribution (PSD) of the seed process. Here, it is demonstrated that the flow rate of the initiator and the second‐stage surfactant are the most important parameters for PSD control. Altering the time point at which the initiator and surfactant are injected allows controlling the relative volume fractions of large and small particles.
DFT Study of a 5‐endo‐trig‐Type Cyclization of 3‐Alkenoic Acids by Using Pd–Spiro‐bis(isoxazoline) as Catalyst: Importance of the Rigid Spiro Framework for Both Selectivity and Reactivity
Authors: Gabr Randa K. , Hatakeyama Takuji , Takenaka Kazuhiro , Takizawa Shinobu , Okada Yoshihiro , Nakamura Masaharu , Sasai Hiroaki
Published: June 2013

The reaction pathway of an enantioselective 5‐endo‐trig‐type cyclization of 3‐alkenoic acids catalyzed by a chiral palladium–spiro‐bis(isoxazoline) complex, Pd–SPRIX, has been studied by density functional theory calculations. The most plausible pathway involves intramolecular nucleophilic attack of the carboxylate moiety on the CC double bond activated by Pd–SPRIX and β‐H elimination from the resulting organopalladium intermediate. The enantioselectivity was determined in the cyclization step through the formation of a π‐olefin complex, in which one of the two enantiofaces of the olefin moiety was selected. The β‐H elimination occurs via a seven‐membered cyclic structure in which the acetate ligand plays a key role in lowering the activation barrier of the transition state. In the elimination step, the SPRIX ligand was found to behave as a monodentate ligand due to the hemilability of one of the isoxazoline units thereby facilitating the elimination. Natural population analysis of this pathway showed that the more weakly electron‐donating SPRIX ligand, compared with the bis(oxazoline) ligand, BOX, facilitated the formation of the π‐olefin complex intermediate, leading to a smaller overall activation energy and a higher reactivity of the Pd–SPRIX catalyst.
Efficient Enantioselective Total Synthesis of (−)‐Horsfiline
Authors: Hong Suckchang , Jung Myunggi , Park Yohan , Ha Min Woo , Park Cheonhyoung , Lee Myungmo , Park Hyeung‐geun
Published: June 2013

A new efficient and concise enantioselective synthetic method for (−)‐horsfiline is reported. (−)‐Horsfiline could be obtained from diphenylmethyl tert‐butyl malonate in 9 steps (32 %,>99 % ee) by using the enantioselective phase‐transfer catalytic allylation (91 % ee) as the key step. This approach can be applied as a practical route for the large‐scale synthesis of spirooxindole natural products, which enables a systematic investigation of their biological activity to be performed.
Synthesis, HPLC Enantioresolution, and X‐ray Analysis of a New Series of C5‐methyl Pyridazines as N‐Formyl Peptide Receptor (FPR) Agonists
Authors: Cilibrizzi Agostino , Crocetti Letizia , Paola Giovannoni Maria , Graziano Alessia , Vergelli Claudia , Bartolucci Gianluca , Soldani Giacomo , Quinn Mark T. , Schepetkin Igor A. , Faggi Cristina
Published: June 2013

The synthesis of three racemates and the corresponding non‐chiral analogues of a C5‐methyl pyridazine series is described here, as well as the isolation of pure enantiomers and their absolute configuration assignment. In order to obtain optically active compounds, direct chromatographic methods of separation by HPLC‐UV were investigated using four chiral stationary phases (CSPs: Lux Amylose‐2, Lux Cellulose‐1, Lux Cellulose‐2 and Lux Cellulose‐3). The best resolution was achieved using amylose tris(5‐chloro‐2‐methylphenylcarbamate) (Lux Amylose‐2), and single enantiomers were isolated on a semipreparative scale with high enantiomeric excess, suitable for biological assays. The absolute configuration of optically active compounds was unequivocally established by X‐ray crystallographic analysis and comparative chiral HPLC‐UV profile. All compounds of the series were tested for formyl peptide receptor (FPR) agonist activity, and four were found to be active, with EC50 values in the micromolar range. Chirality 25:400–408, 2013. © 2013 Wiley Periodicals, Inc.
Enantiomerically Pure Bithiophene Diphosphine Oxides as Catalysts for Direct Double Aldol Reactions
Authors: Genoni Andrea , Benaglia Maurizio , Rossi Sergio , Celentano Giuseppe
Published: June 2013

The direct aldol reaction between aryl methyl ketones with aromatic aldehydes in the presence of tetrachlorosilane and a catalytic amount of a chiral bithiophene diphosphine oxide was studied; the product of double aldol addition was isolated as diacetate in good diastereoselectivity (up to 95:5) and enantioselectivities up to 91%. The reaction with heteroaromatic aldehydes was also investigated leading to the corresponding 1,3 diols, in some cases with excellent stereoselectivities. Chirality 25:643–647:, 2013. © 2013 Wiley Periodicals, Inc.
Population Balance Modeling – Experimental Study with Bubble Columns
Authors: Hlawitschka Mark W. , Seiberth Dorian , Gao Ying , Bart Hans‐Jörg
Published: June 2013

Ein gerührter Blasenkontaktor im Gegenstrom wird mithilfe der Computational Fluid Dynamics (CFD) in Kombination mit der Populationsbilanzmodellierung (PBM) untersucht. Zur Simulation der Hydrodynamik wird auf das Euler‐Euler‐Modell zurückgegriffen, welches jedoch die Widerstandskräfte zwischen den Phasen modelliert. Die Widerstandskraft wird daher in einem Einzelblasenprüfstand bestimmt, bei dem die Blase durch einen Gegenstrom in Schwebe gehalten wird. Hierbei konnte der experimentell bestimmte Widerstandskoeffizient für sphärische Blasen mittels Literaturkorrelationen abgebildet werden. Die Einzelblasenapparatur ermöglicht zudem weitere Untersuchungen zum Stofftransport an ruhenden Blasen. Die durchgeführten CFD‐PBM‐Simulationen des gerührten Blasenkontaktors zeigen eine gute Übereinstimmung mit der experimentell ermittelten Blasengrößenverteilung.
Bacterial Proliferation in Municipal Water Supplied in Mirpur Locality of Dhaka City, Bangladesh
Authors: Acharjee Mrityunjoy , Rahman Farjana , Jahan Fahmida , Noor Rashed
Published: June 2013

Water related environmental pollution has long been a major concern not only in Bangladesh but also in other developing countries. Present study assessed the pathogenic prevalence in municipal water supplied across Mirpur zone, Dhaka, and its subsequent health impact on the local community. Elevated numbers of pathogenic bacteria including Aeromonas spp., Shigella spp., Staphylococcus spp., and Salmonella spp. were found in the consumer points (n = 30) compared to that of the supply points (n = 10). Additionally, proliferation of fecal coliforms, Escherichia coli and Klebsiella spp. was monitored among the consumer points and not in the supply points. Drug resistance was scored against ampicillin (10 µg), ciprofloxacin (5 µg), ceftriazone (30 µg), penicillin (10 µg), nalidixic acid (30 µg), and vancomycin (30 µg). Hence, the municipal water of the study area was microbiologically unsafe, and the propagation of drug resistant strains was assumed to escalate the public health threat. A survey on public opinions was also conducted to evidently chalk out the impact of municipal water on the specific community studied.
Estimating resource selection with count data
Authors: Nielson Ryan M. , Sawyer Hall
Published: June 2013

Resource selection functions (RSFs) are typically estimated by comparing covariates at a discrete set of “used” locations to those from an “available” set of locations. This RSF approach treats the response as binary and does not account for intensity of use among habitat units where locations were recorded. Advances in global positioning system (GPS) technology allow animal location data to be collected at fine spatiotemporal scales and have increased the size and correlation of data used in RSF analyses. We suggest that a more contemporary approach to analyzing such data is to model intensity of use, which can be estimated for one or more animals by relating the relative frequency of locations in a set of sampling units to the habitat characteristics of those units with count‐based regression and, in particular, negative binomial (NB) regression. We demonstrate this NB RSF approach with location data collected from 10 GPS‐collared Rocky Mountain elk (Cervus elaphus) in the Starkey Experimental Forest and Range enclosure. We discuss modeling assumptions and show how RSF estimation with NB regression can easily accommodate contemporary research needs, including: analysis of large GPS data sets, computational ease, accounting for among‐animal variation, and interpretation of model covariates. We recommend the NB approach because of its conceptual and computational simplicity, and the fact that estimates of intensity of use are unbiased in the face of temporally correlated animal location data.
Inferences of evolutionary history of a widely distributed mangrove species, Bruguiera gymnorrhiza, in the Indo‐West Pacific region
Authors: Urashi Chie , Teshima Kosuke M. , Minobe Sumiko , Koizumi Osamu , Inomata Nobuyuki
Published: June 2013

Inference of genetic structure and demographic history is fundamental issue in evolutionary biology. We examined the levels and patterns of genetic variation of a widespread mangrove species in the Indo‐West Pacific region, Bruguiera gymnorrhiza, using ten nuclear gene regions. Genetic variation of individual populations covering its distribution range was low, but as the entire species it was comparable to other plant species. Genetic differentiation among the investigated populations was high. They could be divided into two genetic clusters: the West and East clusters of the Malay Peninsula. Our results indicated that these two genetic clusters derived from their ancestral population whose effective size of which was much larger compared to the two extant clusters. The point estimate of speciation time between B. gymnorrhiza and Bruguiera sexangula was two times older than that of divergence time between the two clusters. Migration from the West cluster to the East cluster was much higher than the opposite direction but both estimated migration rates were low. The past Sundaland and/or the present Malay Peninsula are likely to prevent gene flow between the West and East clusters and function as a geographical or land barrier.
Luminescence in Functionalized Copper Thiolate Clusters – Synthesis and Structural Effects
Authors: Langer Robert , Yadav Munendra , Weinert Bastian , Fenske Dieter , Fuhr Olaf
Published: June 2013

A series of luminescent polynuclear copper(I) phenyl thiolate clusters with functional groups in the organic ligand shell has been synthesized and characterized by single‐crystal X‐ray diffraction. Cluster compounds 1–5 with Me2N groups bound to the phenyl thiolate are described and feature different nuclearities and core geometries. The heptanuclear compound 6, which contains both phenyl thiolate and Me3SiO functionalized phenyl thiolate ligands, is an unusual example of a mixed thiolate cluster and exhibits a core almost identical to that of 5. The optical properties of these compounds, which range from binuclear complexes with large Cu···Cu distances to cluster molecules with seven copper atoms and relatively short Cu···Cu distances, have been investigated. Compounds 1–5 show strong absorption below 500 nm. The intense luminescence covers a wide range of the visible spectrum (1: green; 2 and 3: blue; 4 and 5: yellow). It seems likely that the optical transitions occur between orbitals of the thiol ligands and metal‐centered orbitals; for the species with short Cu···Cu distances (3–5), these interactions cause a further redshift of the spectra. In addition, the influence of functional groups on optical absorption and emission is shown by the two Cu7 clusters 5 and 6, which differ solely in the electron‐donating nature of their functional groups.
Preliminary Theoretical Insights into SmI2‐Mediated Reactions: Activation of Ketones in THF
Authors: Kefalidis Christos E , Perrin Lionel , Maron Laurent
Published: June 2013

The structure of samarium iodide in THF solution and its reactivity towards aromatic ketones has been studied by means of DFT calculations. A comparison between the X‐ray and DFT optimised structure of [SmI2(THF)3(η2‐MeOCH2H4OMe)] and [SmI2(THF)5]+ shows that the use of DFT‐B3PW91 in conjunction with the appropriate relativistic electron core potential is able to reproduce the structures of these complexes. In THF solution, the simulation of SmI2(THF)n complexes reveals that an equilibrium should exist between SmI2(THF)5, SmI2(THF)4, SmI2(THF)3 and dimetallic [SmI(μ‐I)(THF)2]2. The formation of SmI2(THF)2 and the dissociation of an iodide to yield [SmI (THF)n]+ is less likely to occur. A first estimation of the thermodynamics of ketone reduction by SmI2(THF)n is given and qualitative values compared with experiment are presented. Concerning the pinacolic coupling of ketones, a “key intermediate” based on experimental interpretation has been considered. Formation of this so‐called “Streitwiser dimer” is strongly endothermic with respect to the monomeric SmIII–OCPh2 radical anion adduct. A doubly reduced ketone sandwiched between two Sm centres is more likely to occur and is consistent with the overall pinacol coupling reaction.
Color and Brightness Tuning in Heteronuclear Lanthanide Terephthalate Coordination Polymers
Authors: Haquin Victor , Etienne Mael , Daiguebonne Carole , Freslon Stéphane , Calvez Guillaume , Bernot Kevin , Le Pollès Laurent , Ashbrook Sharon E. , Mitchell Martin R. , Bünzli Jean‐Claude , Eliseeva Svetlana V. , Guillou Olivier
Published: June 2013

Heteronuclear lanthanide terephthalate coordination polymers with the general chemical formula [Ln2–2xLn′2x(bdc)3(H2O)4]∞, for which bdc2– symbolizes benzene‐1,4‐dicarboxylate (or terephthalate) and Ln and Ln′ represent trivalent rare earth ions, were synthesized and structurally characterized. Analysis of the Y/Lu compounds by 89Y and 13C solid‐state NMR spectroscopy was carried out, and the results support the hypothesis of randomly distributed lanthanide ions. The spectroscopic and colorimetric properties of this family of compounds were investigated in detail. The resulting data demonstrate that this series of compounds presents highly tunable luminescence properties and clearly indicate that intermetallic deactivation processes play an important role in the emission mechanism. Playing with intermetallic distances allows one to tune the color and the brightness of the lanthanide emission in these coordination polymers.