bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensorless induction machine observation with nonlinear magnetic characteristic
Authors: El Fadili A. , Giri F. , El Magri A. , Besançon G. 
Published: April 2013

SUMMARYThis paper addresses the problem of state estimation in induction motors. Generally, the motor observer design has been dealt based on standard models neglecting the saturation effect in the magnetic characteristic. As a matter of fact, magnetic saturation cannot be ignored especially when considering control strategies (speed and torque) that involve large flux variations. Such large flux variations are necessary to meet optimal operation conditions in the presence of wide range load torque changes. On the other hand, it is well known that use of mechanical (speed and torque) sensors entails reliability issues. In this paper, a new sensorless adaptive observer is designed for induction machine based on a model that accounts for the nonlinear feature in the magnetic circuit. The observer consists of two interconnected state‐dependent gain observers and is formally shown to provide accurate estimates of the mechanical and magnetic variables using only stator current and voltage measurements. Copyright © 2013 John Wiley & Sons, Ltd.
Bioacoustic Field Research: A Primer to Acoustic Analyses and Playback Experiments With Primates
Authors: FISCHER JULIA , NOSER RAHEL , HAMMERSCHMIDT KURT 
Published: April 2013

AbstractAcoustic analyses of primate vocalizations as well as playback experiments are staple methods in primatology. Acoustic analyses have been used to investigate the influence of factors such as individuality, context, sex, age, and size on variation in calls. More recent studies have expanded our knowledge on the effects of phylogenetic relatedness and the structure of primate vocal repertoires in general. Complementary playback experiments allow direct testing of hypotheses regarding the attribution of meaning to calls, the cognitive mechanisms underpinning responses, and/or the adaptive value of primate behavior. After briefly touching on the historical background of this field of research, we first provide an introduction to recording primate vocalizations and discuss different approaches to describe primate calls in terms of their temporal and spectral properties. Second, we present a tutorial regarding the preparation, execution, and interpretation of field playback experiments, including a review of studies that have used such approaches to investigate the responses to acoustic variation in calls including the integration of contextual and acoustic information, recognition of kin and social relationships, and social knowledge. Based on the review of the literature and our own experience, we make a number of recommendations regarding the most common problems and pitfalls. The power of acoustic analyses typically hinges on the quality of the recordings and the number of individuals represented in the sample. Playback experiments require profound knowledge of the natural behavior of the animals for solid interpretation; experiments should be conducted sparingly, to avoid habituation of the subjects to the occurrence of the calls; experimenter‐blind designs chosen whenever possible; and researchers should brace themselves for long periods of waiting times until the appropriate moments to do the experiment arise. If all these aspects are considered, acoustic analyses and field playback experiments provide unique insights into primate communication and cognition. Am. J. Primatol. 75:643–663, 2013. © 2013 Wiley Periodicals, Inc.
The north‐west of the Iberian Peninsula is crucial for conservation of Margaritifera margaritifera (L.) in Europe
Authors: Lois S. , Ondina P. , Outeiro A. , Amaro R. , San Miguel E. 
Published: April 2013

ABSTRACT

Extensive assessments of a species distribution, its variation in density and demographic status across environments are crucial to develop successful conservation efforts.
The freshwater pearl mussel (Margaritifera margaritifera) is considered one of the most endangered freshwater bivalves with many recovery efforts continuing throughout its geographic range. The distribution and conservation status of M. margaritifera are not well documented in the Iberian Peninsula. Galicia (NW Iberian Peninsula) represents nearly 70% of the historical distribution of the species in the southern limit of its European range.
An extensive field survey was conducted in two phases at 2436 locations. The presence and density of M. margaritifera was determined at 555 sampling points spread across 54 rivers that belong to 23 drainage basins in Galicia. The present work has more than doubled the number of rivers known to provide habitat for this endangered species in the Iberian Peninsula.
In Galicia the species is heterogeneously distributed with a highly variable density of individuals within and between rivers. For example, within the River Camba density ranged from 0.02 to 47.8 ind m‐2. The maximum density detected in a sample was 332 ind m‐2. Twelve rivers in Galicia are thought to have more than 5000 individuals, and small individuals were found in 11 rivers.
High rates of decline and extinction of M. margaritifera populations are known in some areas and the main threat to unionoid bivalves is a lack of natural recruitment. Thus, Galician populations are important for providing new opportunities for conservation of the species in Europe because it is vitally important to find the reasons for recruitment failure. Copyright © 2013 John Wiley & Sons, Ltd.
Design, Synthesis, Antioxidant, and Anti‐Breast Cancer Activities of Novel Diethyl(alkyl/aryl/heteroarylamino)(4‐(pyridin‐2‐yl)phenyl)methylphosphonates
Authors: Prasad Sthanikam Siva , Kumar Krishnammagari Suresh , Jayaprakash Soora Harinath , Krishna Balam Satheesh , Sundar Chereddy Syama , Rao Pasupuleti Visweswara , Babu Tirumalasetty Munichandra , Rajendra Wudayagiri , Reddy Cirandur Suresh 
Published: April 2013

AbstractA series of new diethyl(alkyl/aryl/heteroarylamino)(4‐(pyridine‐2‐yl)phenyl)methylphosphonates (4a–t) were synthesized via three‐component Kabachnik–Field's reaction of 4‐(pyridin‐2‐yl)benzaldehyde, diethylphosphite and various primary amines, catalyzed by cupric acetate monohydrate [Cu(OAc)2 · H2O] under solvent‐free and microwave irradiation conditions. Their computational docking analysis supported them as good therapeutic agents to the breast cancer aromatase enzyme and ascertained 4a, 4h, 4m, 4n, and 4t as potential molecules with good binding affinities varying from −9.0 to −9.6 kcal/mol and containing the 4‐(pyridine‐2‐yl)phenyl moiety as a pharmacophore. Their in vitro screening performed for the anti‐cell proliferation activity against MBC‐MCF7 cells by MTT and Trypan blue assays confirmed 4m, 4n, and 4q as promising compounds to sustain a low percentage of cell viability at 20 µg/mL concentration. These compounds were also evaluated for their antioxidant activity by the DPPH method and the results established that compounds 4m, 4n, and 4q show around 10% higher activity than the standard antioxidant ascorbic acid.
Remote influence of North Atlantic SST on the equatorial westerly wind anomalies in the western Pacific for initiating an El Niño event: an Atmospheric General Circulation Model Study
Authors: Wang Xin , Wang Chunzai , Zhou Wen , Liu Lin , Wang Dongxiao 
Published: April 2013

AbstractThis article uses an atmospheric general circulation model to show that the cooler North Atlantic sea surface temperature anomalies in summer can produce a Rossby wave‐like teleconnection pattern strengthening the Siberian High in winter and next spring. The stronger Siberian High enhances the continent northerlies over East Asia and the associated cyclonic circulation over the western North Pacific, which provides a tropical westerly background for occurrence of the westerly wind bursts. The stronger northerlies over East Asia can also induce frequent cold surges, which tend to produce the equatorial westerly wind anomalies in the western Pacific for initiating an El Niño event. Copyright © 2013 Royal Meteorological Society
Harnessing Candida tenuis and Pichia stipitis in whole‐cell bioreductions of o‐chloroacetophenone: Stereoselectivity, cell activity, in situ substrate supply and product removal
Authors: Gruber Christoph , Krahulec Stefan , Nidetzky Bernd , Kratzer Regina 
Published: April 2013

AbstractGenerally, recombinant and native microorganisms can be employed as whole‐cell catalysts. The application of native hosts, however, shortens the process development time by avoiding multiple steps of strain construction. Herein, we studied the NAD(P)H‐dependent reduction of o‐chloroacetophenone by isolated xylose reductases and their native hosts Candida tenuis and Pichia stipitis. The natural hosts were benchmarked against Escherichia coli strains co‐expressing xylose reductase and a dehydrogenase for co‐enzyme recycling. Xylose‐grown cells of C. tenuis and P. stipitis displayed specific o‐chloroacetophenone reductase activities of 366 and 90 U gCDW–1, respectively, in the cell‐free extracts. Fresh biomass was employed in batch reductions of 100 mM o‐chloroacetophenone using glucose as co‐substrate. Reaction stops at a product concentration of about 15 mM, which suggests sensitivity of the catalyst towards the formed product. In situ substrate supply and product removal by the addition of 40% hexane increased catalyst stability. Optimisation of the aqueous phase led to a (S)‐1‐(2‐chlorophenyl)ethanol concentration of 71 mM (ee > 99.9%) obtained with 44 gCDW L–1 of C. tenuis. The final difference in productivities between native C. tenuis and recombinant E. coli was < 1.7‐fold. The optically pure product is a required key intermediate in the synthesis of a new class of chemotherapeutic substances (polo‐like kinase 1 inhibitors).
Protein engineering for metabolic engineering: Current and next‐generation tools
Authors: Marcheschi Ryan J. , Gronenberg Luisa S. , Liao James C. 
Published: April 2013

AbstractProtein engineering in the context of metabolic engineering is increasingly important to the field of industrial biotechnology. As the demand for biologically produced food, fuels, chemicals, food additives, and pharmaceuticals continues to grow, the ability to design and modify proteins to accomplish new functions will be required to meet the high productivity demands for the metabolism of engineered organisms. We review advances in selecting, modeling, and engineering proteins to improve or alter their activity. Some of the methods have only recently been developed for general use and are just beginning to find greater application in the metabolic engineering community. We also discuss methods of generating random and targeted diversity in proteins to generate mutant libraries for analysis. Recent uses of these techniques to alter cofactor use; produce non‐natural amino acids, alcohols, and carboxylic acids; and alter organism phenotypes are presented and discussed as examples of the successful engineering of proteins for metabolic engineering purposes.
Metabolic gradients as key regulators in zonation of tumor energy metabolism: A tissue‐scale model‐based study
Authors: König Matthias , Holzhütter Hermann‐Georg , Berndt Nikolaus 
Published: April 2013

AbstractCharacteristics of many tumor types are the reprogramming of metabolism and the occurrence of regional hypoxia. In this work, we investigated the hypothesis that metabolic reprogramming in combination with metabolic zonation of cellular energy metabolism are important factors in promotion of the growth capacity of solid tumors. A tissue‐scale model of the two main ATP delivering pathways, glycolysis (GLY) and oxidative phosphorylation (OXP), was used to simulate the energy metabolism within solid tumors under various metabolic strategies. Remarkably, despite the high diversity in the usage of glucose, lactate and oxygen in various spatial regions, the tumor as a whole clearly displays the hallmark of the so‐called Warburg effect, i.e. a high rate of glucose consumption and lactate production in the presence of sufficiently high levels of oxygen. Our simulations suggest that an increase in GLY capacity and concomitant decrease in OXP capacity from the periphery towards the center of the tumor improves the availability of oxygen to pericentral tumor cells. The found relationship between the regional oxygen level and the relative share of GLY and OXP capacities supports the view that metabolite availability functions as key regulator of tumor energy metabolism.
The challenge of improved secretory production of active pharmaceutical ingredients in Saccharomyces cerevisiae: A case study on human insulin analogs
Authors: Kazemi Seresht Ali , Palmqvist Eva A. , Schluckebier Gerd , Pettersson Ingrid , Olsson Lisbeth 
Published: April 2013

ABSTRACTThe yeast Saccharomyces cerevisiae has widely been used as a host for the production of heterologous proteins. Great attention has been put on improved secretory production of active pharmaceutical ingredients, and the secretory pathway of this eukaryotic host has been the playground of diverse strain engineering studies, aiming at enhanced cellular capacities for folding and trafficking of the target proteins. However, the cellular quality assessment for secretory proteins remains mostly unpredictable, and different target proteins often do not picture similar secretion yields, underlining the dependency of efficient secretion on the physicochemical properties of the protein of interest. In this study, two human insulin analog precursors (IAPs) with minor differences in their amino acid sequences were used as model secretory proteins. No differences between cells expressing these two proteins were found in the IAP transcript levels, gene copy numbers, or intra‐cellularly accumulated proteins, yet a more than sevenfold difference in their secretion yields was found. Physiological characterization of cells expressing these proteins in batch processes revealed no significant difference in their specific growth rate, but an altered overflow metabolism. Global transcriptome analysis carried out in chemostat experiments pinpointed distinct steps during the protein maturation pathway to be differentially regulated and indicated an increased degradation of the IAP with the low secretion yield. In silico protein structure modeling of the IAPs suggested a difference in conformational stability, induced by the amino acid substitution, which most likely resulted in disparity in trafficking through the secretory pathway and thus a large difference in secretion yields. Biotechnol. Bioeng. 2013;110: 2764–2774. © 2013 Wiley Periodicals, Inc.
Production of a novel O‐methyl‐isoflavone by regioselective sequential hydroxylation and O‐methylation reactions in Streptomyces avermitilis host system
Authors: Choi Kwon‐Young , Jung EunOk , Yang Yung‐Hun , Kim Byung‐Gee 
Published: April 2013

ABSTRACTDistinct isoflavone O‐methyltransferases (IOMTs) from Streptomyces species were isolated and expressed using S. avermitilis host system. Previously reported isoflavone 7‐O‐methyltransferases (I7OMTs, E.C. 2.1.1.150) and two putative O‐methyltransferases (OMTs) from Saccharopolyspora erythraea were selected by comparative sequence grouping and expressed in S. avermitilisΔSaOMT2 under the control of constitutive ermE promoter. During whole‐cell biotransformation of 4′,7‐dihydroxyisoflavone (daidzein) by constructed recombinant strains, production of O‐methylated daidzein was investigated. S. avermitilisΔSaOMT2::SeOMT3 (SeOMT3) produced 7‐methoxy‐4′‐hydroxyisoflavone (7‐OMD) with 4.5% of low conversion yield due to competitive oxidation reactions. However, SeOMT3 could produce a novel 4′,7‐dihydroxy‐3′‐methoxyisoflavone (3′‐OMD) (<1%) resulted from subsequent 3′‐O‐methylation of 3′,4′,7‐trihydroxyisoflavone (3′‐OHD) which was a hydroxylated product catalyzed by oxygenases. Although external addition of SAM did not change the conversion yield of O‐methylation reaction, co‐expression of SAM synthetase gene (metK) with SeOMT3 greatly induced the regiospecific O‐methylation reaction at 3′‐hydroxyl group with final conversion of 12.1% using 0.1 mM of daidzein. Biotechnol. Bioeng. 2013;110: 2591–2599. © 2013 Wiley Periodicals, Inc.
Model predicting impact of complexation with cyclodextrins on oral absorption
Authors: Gamsiz Ece D. , Thombre Avinash G. , Ahmed Imran , Carrier Rebecca L. 
Published: April 2013

ABSTRACTSignificant effort and resource expenditure is dedicated to enabling low‐solubility oral drug delivery using solubilization technologies. Cyclodextrins (CD) are cyclic oligosaccharides which form inclusion complexes with many drugs and are often used as solubilizing agents. It is not clear prior to developing a drug delivery device with CD what level of absorption enhancement might be achieved; modeling can provide useful guidance in formulation and minimize resource intensive iterative formulation development. A model was developed to enable quantitative, dynamic prediction of the influence of CD on oral absorption of low solubility drug administered as a pre‐formed complex. The predominant effects of CD considered were enhancement of dissolution and slowing of precipitation kinetics, as well as binding of free drug in solution. Simulation results with different parameter values reflective of typical drug and CD properties indicate a potential positive (up to five times increase in drug absorption), negative (up to 50% decrease in absorption) or lack of effect of CD. Comparison of model predictions with in vitro and in vivo experimental results indicate that a systems‐based dynamic model incorporating CD complexation and key process kinetics may enable quantitative prediction of impact of CD delivered as a pre‐formed complex on drug bioavailability. Biotechnol. Bioeng. 2013; 110:2536–2547. © 2013 Wiley Periodicals, Inc.
A lumen sizing workhorse guidewire for peripheral vasculature: Two functions in one device
Authors: Svendsen Mark C. , Choy Jenny S. , Ebner Adrian , Bigelow Brian , Sinha Anjan , Moussa Issam , Akingba A. George , Combs Bill , Kassab Ghassan S. 
Published: April 2013

ObjectivesIdeally, guidewires used during peripheral vasculature (PV) interventions could serve both as a therapy delivery platform and a diagnostic tool for real‐time vessel sizing (2‐in‐1 function).BackgroundVascular imaging modalities, like intravascular ultrasound (IVUS), used during lower PV interventions, can improve outcomes versus angiographic assessment alone, but are rarely used due to added time, cost, and required clinical training/interpretation.MethodsA 0.035″ bodied 0.035″ conductance guidewire (CGW) is described here as a vascular navigation and diagnostic real‐time PV sizing tool. When attached to a console, the CGW creates a safe, electric field to determine vascular size through simultaneous voltage measurements.ResultsThe CGW showed functionality as a workhorse guidewire on the bench (torqueability and trackability equivalent to a Wholey guidewire) and in vivo (over‐the‐wire stent deployment in domestic swine and first‐in‐man study with no major adverse events). Validation of CGW sizing versus the true diameter and IVUS was completed in 4–10 mm diameter phantoms on the bench and in swine and showed virtually no bias with excellent repeatability and accuracy (i.e., CGW repeatability: swine phantom bias = 0.03 ± 0.09 mm (1.3% error). CGW vs. true diameter: in vivo bias = 0.14 ± 0.15 mm (2.7% error). IVUS vs. true diameter: swine phantom bias = 0.01 ± 0.36 mm (4.7% error). CCW vs. IVUS: swine phantom bias = 0.13 ± 0.26mm (3.8% error)).ConclusionsReal‐time, accurate, and safe PV dimension assessment and therapy‐delivery (2‐in‐1 function) is possible using a novel workhorse 0.035″ bodied CGW. © 2013 Wiley Periodicals, Inc.
Radiation dose of patients undergoing transcatheter aortic valve implantation: A comparison between edwards SAPIEN XT and medtronic corevalve aortic valve prostheses
Authors: Steinvil Arie , Aviram Galit , Konigstein Maayan , Abramowitz Yigal , Halkin Amir , Arbel Yaron , Ben‐Gal Yanai , Keren Gad , Banai Shmuel , Finkelstein Ariel 
Published: April 2013

BackgroundThe relative radiation dose (RD) of patients undergoing transcatheter aortic valve implantation (TAVI) with either the Edwards Sapien XT (ESX) or the Medtronic CoreValve (MCV) prostheses has not been studied in depth. Our aim was to quantify RD in uncomplicated transfemoral TAVI with either prosthesis.MethodsWe analyzed 248 consecutive patients undergoing uncomplicated transfemoral TAVI between March 2009 and September 2012, at a single tertiary care facility. Total air Kerma, cumulated dose area product (DAP), and fluoroscopy time were determined in each case.ResultsThe ESX and MCV prostheses were implanted in 44 and 204 patients, respectively. Though mean fluoroscopy time was higher during ESX valve implantation, overall RD per total air Kerma and DAP was significantly higher during MCV implantation (P < 0.05 for both comparisons). By multivariate regression analyses, prosthesis type was an independent predictor of RD according to both total air Kerma and DAP (r2 = 0. 498; P < 0.01 and r2 = 0.363; P < 0.01, respectively).ConclusionIn uncomplicated transfemoral TAVI, RD is greater during MCV implantation than during ESX implantation. © 2013 Wiley Periodicals, Inc.
Hemodynamic impact of changes in bifurcation geometry after single‐stent cross‐over technique assessed by intravascular ultrasound and fractional flow reserve
Authors: Kang Soo‐Jin , Kim Won‐Jang , Lee Jong‐Young , Park Duk‐Woo , Lee Seung‐Whan , Kim Young‐Hak , Lee Cheol Whan , Mintz Gary S. , Park Seong‐Wook , Park Seung‐Jung 
Published: April 2013

BackgroundAngiographic stenosis of a sidebranch (SB) ostium is common after single‐stent cross‐over, but it is usually not hemodynamically significant. We evaluated the relationship between the mechanisms of SB stenosis and its hemodynamic significance.Methods and ResultsWe used preinterventional and post‐interventional intravascular ultrasound (IVUS) of the main branch (MB) and the SB and post‐intervention fractional flow reserve (FFR) of the SB to assess 40 nonleft main bifurcation lesions after a single stent cross‐over. Although post‐stenting angiographic diameter stenosis >50% was seen in 19 (48%) SB lesions, only 6 (15%) showed FFR < 0.80. Carina shift was seen in all but one lesion; and plaque shift superimposed on the carina shift was found in 18 (45%) lesions. The change in plaque area at the SB ostium positively correlated with preprocedural plaque burden at the carina of distal MB r = 0.341, P = 0.031). Plaque shift was more common in lesions with FFR < 0.80 vs. ≥0.80 (83% vs. 38%, P = 0.041); and FFR < 0.80 was more frequent in lesions with plaque shift superimposed on carina shift versus isolated carina shift (28% vs. 5%, P = 0.041).ConclusionsAlthough carina shift was the main mechanism of SB lumen loss after a single stent cross‐over technique, plaque shift superimposed on carina shift appeared to be necessary to cause a hemodynamically significant stenosis (FFR < 0.80). However, post‐procedural IVUS assessment did not accurately predict the functional significance. © 2013 Wiley Periodicals, Inc.