bluuebunny/crossref_metadata_2025 huggingface dataset:
Single intratympanic gentamicin injection in Ménière's disease: VOR change and prognostic usefulness
Authors: Marques Pedro , Manrique‐Huarte Raquel , Perez‐Fernandez Nicolas
Published: January 2015

Objective

Assess angular vestibular‐ocular reflex (VOR) changes after treatment with intratympanic gentamicin (ITG) for Ménière's disease (MD) and impact on short‐term follow‐up.

Design

Prospective study.

Methods

Patients submitted to ITG for unilateral MD. The gain VOR and the presence of compensatory saccades elicited by rapid head impulses were measured using the video head impulse test (vHIT).

Results

The study included 31 subjects (mean age: 59 years). Functional Level Scale (FLS) distributions were 35,5% (FLS3); 32,2% (FLS4); and 32,2% (FLS5). Mean follow‐up was 21 ± 7 months. Multiple injections were needed in nine patients.

VOR gain in the treated ear was significantly reduced in all subjects and for all the semicircular canals (paired samples t test; P < 0,05). Gain averages after treatment were 0,61 (superior); 0,69 (horizontal); and 0,47 (posterior). A horizontal canal VOR gain superior to 0,80 after treatment was associated with the need for a second gentamicin injection (Chi‐square; P = 0,003). Gain asymmetry between the symptomatic and asymptomatic ear (GASM) was increased after treatment. The rate of vestibular function reduction was 47,9%; 26,0%; and 35,8% for the superior, horizontal, and posterior canals, respectively. According to the receiving operator characteristic curve, the amount of change in GASM must be greater than 7 in order to predict the avoidance of a second procedure (area under the curve [AUC] horizontal canal = 0,861) and the amount of vestibular function reduction in the pathologic ear in patients with a controlled disease must be greater than 17,8% (AUC horizontal canal = 0,843).

Conclusions

When evaluated with the vHIT, intratympanic gentamicin changes in VOR seem to foresee short‐term control of vertigo attacks.

Level of Evidence

4. Laryngoscope, 125:1915–1920, 2015
A comparison between autograft alone, bone cement, and demineralized bone matrix in cranioplasty
Authors: Plum Ann W. , Tatum Sherard A.
Published: January 2015

Objectives

To compare bone autograft, bone cement, and demineralized bone matrix in functional and aesthetic outcomes and complications following cranioplasty for reconstruction of cranial defects.

Study Design

Retrospective chart review.

Materials and Methods

A retrospective chart review was performed of patients who underwent cranioplasty at a single institution between 1992 and 2012. The patients were divided based on whether bone autograft, demineralized bone matrix, or bone cement was used for reconstruction of their craniofacial defect. Demographics and diagnosis data were collected. Complications and cosmetic outcomes were examined for each group.

Results

There was no significant difference between groups regarding follow‐up and age at time of surgery. The bone cement group had a higher infection rate. There was more dehiscence and scalp scarring in the autograft and bone cement groups. However, residual bone defects and the need for a revision cranioplasty were higher in the bone matrix group. Likewise, patient, parent, and surgeon satisfaction with the appearance was lower in the bone matrix group.

Conclusions

There appears to be a trend toward a lower success rate in patients with fibroblast growth factor receptor‐related craniosynostosis and in those reconstructed with bone matrix compared to bone autograft and bone cement.

Level of Evidence

4. Laryngoscope, 125:1322–1327, 2015
A randomized controlled trial of simulation‐based training for ear, nose, and throat emergencies
Authors: Smith Matthew Edward , Navaratnam Annakan , Jablenska Lily , Dimitriadis Panagiotis A. , Sharma Rishi
Published: January 2015

Objectives/Hypothesis

Life‐threatening ear, nose, and throat (ENT) emergencies are uncommon but require immediate skilled management. We investigated if traditional lecture‐based teaching can be improved by a simulation and lecture hybrid approach.

Study Design

A single‐blinded, prospective, randomized controlled trial.

Methods

Two groups of interns with no previous ENT experience were randomized to one of two training groups: a simulation/lecture hybrid group or a lecture‐only control group. Both groups received 90 minutes of training covering the assessment of critically ill patients and four ENT emergency topics. Both groups received the same initial lecture slides. The control group received additional slides, and the simulation group received simulated emergency scenario training using basic mannequins. Following the training, candidates were asked to provide feedback on their perception of training, and they were formally assessed with a standardized one‐to‐one viva.

Results

Thirty‐eight interns were recruited: 18 in the control group and 20 in the simulation group. The candidates in the simulation group performed significantly better in all viva situations (P < .05) and had better perception of learning (P < .05). Additionally, the simulation group was more likely to recommend the training to a colleague (P < .05).

Conclusions

We have demonstrated that replacing traditional lecture‐based training with a mixture of lectures and emergency scenario simulation is more effective at preparing junior doctors for ENT emergencies, and better met their learning needs. Implementing this kind of teaching is feasible with a minimum of additional resources or time.

Level of Evidence

1b Laryngoscope, 125:1816–1821, 2015
Facile Synthesis and Structural Characterization of Amylose–Fatty Acid Inclusion Complexes
Authors: Cao Zheng , Woortman Albert J. J. , Rudolf Petra , Loos Katja
Published: January 2015

Amylose‐fatty acid inclusion complexes can be easily prepared by simple mixing in hot aqueous solutions. Above a critical chain length (C6) of the fatty acid insoluble complexes between amylose and each fatty acid (C8, C10, C12, C14, C16) were precipitated from the solution, and characterized by FT‐IR, XRD, DSC, and SEC. The presence of the characteristic (CO) FT‐IR absorption peak at 1 710 cm−1 confirmed the inclusion of the fatty acids inside the amylose helix. XRD showed the same characteristic features of the V amylose single helical structure. Both SEC and DSC revealed that longer fatty acids can form inclusion complexes with amylose fractions having higher degree of polymerization, leading to greater yields, and higher thermal stability (higher melting temperature and enthalpy) of the amylose‐complexes.
Functional chimeras of flagellar stator proteins between E. coli MotB and Vibrio PomB at the periplasmic region in Vibrio or E. coli
Authors: Nishino Yuuki , Onoue Yasuhiro , Kojima Seiji , Homma Michio
Published: January 2015

The bacterial flagellar motor has a stator and a rotor. The stator is composed of two membrane proteins, MotA and MotB in Escherichia coli and PomA and PomB in Vibrio alginolyticus. The Vibrio motor has a unique structure, the T ring, which is composed of MotX and MotY. Based on the structural information of PomB and MotB, we constructed three chimeric proteins between PomB and MotB, named PotB91, PotB129, and PotB138, with various chimeric junctions. When those chimeric proteins were produced with PomA in a ΔmotAB strain of E. coli or in ΔpomAB and ΔpomAB ΔmotX strains of Vibrio, all chimeras were functional in E. coli or Vibrio, either with or without the T ring, although the motilities were very weak in E. coli. Furthermore, we could isolate some suppressors in E. coli and identified the mutation sites on PomA or the chimeric B subunit. The weak function of chimeric PotBs in E. coli is derived mainly from the defect in the rotational switching of the flagellar motor. In addition, comparing the motilities of chimera strains in ΔpomAB, PotB138 had the highest motility. The difference between the origin of the α1 and α2 helices, E. coli MotB or Vibro PomB, seems to be important for motility in E. coli and especially in Vibrio.
Computational Investigation and Experimental Validation of Crizotinib Resistance Conferred by C1156Y Mutant Anaplastic Lymphoma Kinase
Authors: Kumar Anish , Shanthi V. , Ramanathan K.
Published: January 2015

Crizotinib is an anticancer drug approved by FDA for the treatment of non‐small cell lung cancer (NSCLC). The main target for crizotinib was anaplastic lymphoma kinase (ALK). However, evidences available indicate that C1156Y mutation in ALK confers resistance to crizotinib. Unfortunately, how mutation actually confers drug resistance is not well understood. Hence, in the present study computational approaches have been employed alongside KINOMEscan profiling technique to reveal the mechanism behind crizotinib resistance in ALK at a molecular level. The results of our analysis indicate that C1156Y mutation alters the conformation of the ALK binding pocket residues which results in a marked decrease in hydrogen bond interactions between crizotinib and ALK. This indicates that hydrogen bonding was a crucial effector of decreased binding affinity. Interestingly, the docking study also indicates that C1156Y mutation increases the affinity for ATP. Finally, our analysis theoretically suggests that M‐1199 is a key residue responsible for the ALK drug selectivity. We certainly believe that these results may be immense importance for the molecular level understanding of crizotinib resistance pattern and also for designing a potential drug molecule for the treatment of lung cancer in the near future.
Global attractivity for a class of delayed discrete SIRS epidemic models with general nonlinear incidence
Authors: Teng Zhidong , Wang Lei , Nie Linfei
Published: January 2015

This paper deals with global dynamics of a class of delayed discrete susceptible‐infected‐recovered (SIR) compartmental epidemic models with general nonlinear incidence rate and disease‐induced mortality, which are proposed from the Mickens nonstandard discretization of the corresponding delayed continuous epidemic models. By constructing discrete Lyapunov functions, the sufficient conditions for the global attractivity of the disease‐free equilibrium and endemic equilibrium are established. Under some additional assumptions (see (H3) in Section 3 and (H4) in Section 4), it is shown that the disease‐free equilibrium is globally attractive when basic reproduction number
, and when
, there is a unique endemic equilibrium, which is globally attractive. Furthermore, some special cases are discussed, and as corollaries, several idiographic results are established. Copyright © 2015 John Wiley & Sons, Ltd.
Spin echoes in the regime of weak dephasing
Authors: Assländer Jakob , Glaser Steffen J. , Hennig Jürgen
Published: January 2015

Purpose

This article analyzes possibilities and limits of spin echoes beyond Hahn's theory. The regime of weak dephasing is explored with the purpose of combining the enhanced signal and reduced artifacts of spin echoes with the speed and flexibility of the fast low angle shot sequence.

Methods

In the regime of weak dephasing, an upper boundary of the echo time is derived analytically. This limit is verified with optimal control pulses, which are also used to heuristically examine the transition to Hahn's regime of complete dephasing. The potential of the proposed pulses is demonstrated in proof‐of‐concept spin echo fast low angle shot images of a volunteer's lung and head.

Results

It was found that the time between the end of the pulse and the spin echo can exceed the duration of the composite radio frequency‐pulse, which stands in contrast to Hahn echoes where those measures are at most equal. The maximum echo time was found to mainly depend on the total amount of dephasing. In vivo spin echo fast low angle shot images show an increased pulmonary signal as well as reduced artifacts in areas affected by susceptibility differences.

Conclusion

The spin dynamics in the regime of weak dephasing was investigated and the feasibility of spin echo fast low angle shot imaging was demonstrated in vivo. Magn Reson Med 75:150–160, 2016. © 2015 Wiley Periodicals, Inc.
Baukasten der Natur
Authors: Wich Peter R.
Published: January 2015

Mit synthetischen Tools können Chemiker Biomakromoleküle so modifizieren, dass deren Materialeigenschaften neue Anwendungsgebiete erschließen, etwa in der Biomedizin.
Hyperpolarized [1,13C]pyruvate in lysed human erythrocytes: effects of co‐substrate supply on reaction time courses
Authors: Pagès Guilhem , Tan Yee Ling , Kuchel Philip W.
Published: January 2015

Hyperpolarized [1,13C]pyruvate was injected rapidly into haemolysates in which hydrolysis of nicotinamide adenine dinucleotide (phosphate) (NAD(P))/NAD(P)H had been inhibited with nicotinamide. Haemolysates provide a stable glycolytic system in which membrane permeability is not a flux‐controlling step, and they enable the concentration of NADH to be adjusted experimentally while keeping the rest of the sample with the same composition as that of the cytoplasm of the cell (albeit diluted twofold at the time of injection of the [1,13C]pyruvate). We showed that the maximum amplitude of the 13C NMR signal from the [1,13C]l‐lactate, produced from [1,13C]pyruvate, and the time at which it occurred was dependent on NADH concentration, as predicted by enzyme‐kinetic analysis. The main feature of such curves was dictated by the immediacy of the supply of the co‐substrate of lactate dehydrogenase (LDH, EC 1.1.1.27), and we posit that this also pertains in vivo in various tissues including neoplasms. By constructing an appropriate mathematical model and by using a Markov‐chain Monte Carlo approach, we fitted experimental data to estimate LDH and NADH concentrations. Experiments carried out with only endogenous NADH present enabled the estimation of its effective concentration in human RBCs; the ability to make this estimate is a special feature of the rapid‐dissolution dynamic nuclear polarization method. We found an endogenous NADH concentration in human RBCs two to four times higher than previously reported. Copyright © 2014 John Wiley & Sons, Ltd.
Cell cycle deregulation and mosaic loss of Ext1 drive peripheral chondrosarcomagenesis in the mouse and reveal an intrinsic cilia deficiency
Authors: de Andrea Carlos E , Zhu Ju‐Fen , Jin Huifeng , Bovée Judith VMG , Jones Kevin B
Published: January 2015

Peripheral chondrosarcoma (PCS) develops as malignant transformation of an osteochondroma, a benign cartilaginous outgrowth at the bone surface. Its invasive, lobular growth despite low‐grade histology suggests a loss of chondrocyte polarity. The known genetics of osteochondromagenesis include mosaic loss of EXT1 or EXT2 in both hereditary and non‐hereditary cases. The most frequent genetic aberrations in human PCS also include disruptions of CDKN2A or TP53. In order to test the sufficiency of either of these to drive progression of an osteochondroma to PCS, we added conditional loss of Trp53 or Ink4a/Arf in an Ext1‐driven mouse model of osteochondromagenesis. Each additional tumour suppressor silencing efficiently drove the development of growths that mimic human PCS. As in humans, lobules developed from both Ext1‐null and Ext1‐functional clones within osteochondromas. Assessment of their orientation revealed an absence of primary cilia in the majority of mouse PCS chondrocytes, which was corroborated in human PCSs. Loss of primary cilia may be responsible for the lost polarity phenotype ascribed to PCS. Cilia deficiency blocks proliferation in physeal chondrocytes, but cell cycle deregulation is sufficient to rescue chondrocyte proliferation following deciliation. This provides a basis of selective pressure for the frequent cell‐cycle regulator silencing observed in peripheral chondrosarcomagenesis. Mosaic loss of Ext1 combined with loss of cell cycle regulators promotes peripheral chondrosarcomagenesis in the mouse and reveals deficient ciliogenesis in both the model and the human disease, explaining biological behaviour including lobular and invasive growth. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Synthesis, self‐assembly and redox‐responsive properties of well‐defined hydroxypropylcellulose‐graft‐poly(2‐acryloyloxyethyl ferrocenecarboxylate) copolymers
Authors: Li Pingping , Kang Hongliang , Che Ning , Liu Zhijing , Zhang Chao , Cao Chun , Li Weiwei , Liu Ruigang , Huang Yong
Published: January 2015

Well‐defined amphiphilic graft copolymers, hydroxypropylcellulose‐graft‐poly(2‐acryloyloxyethyl ferrocenecarboxylate) (HPC‐g‐PAEFC), were synthesized via atom transfer radical polymerization. The graft copolymers contain hydrophilic thermo‐responsive HPC backbones and hydrophobic redox‐sensitive PAEFC side chains and can self‐assemble into spherical micelles in aqueous solution, with a hydrodynamic radius  in the range 70–130 nm depending on length of the graft chains. The thermo‐responsive properties of the HPC‐g‐PAEFC copolymers in aqueous solution are gradually destroyed with increasing length of PAEFC side chains. The redox‐responsive behaviors of the graft copolymers were investigated with H2O2 and sodium ascorbate as oxidant and reductant, respectively, indicating an incompletely reversible redox‐triggered size transition. And the reversibility of the redox process becomes weaker gradually as the side chains are more difficult to be oxidized with an increase of the graft chains, which is evidenced from cyclic voltammetry measurements. The resultant HPC‐g‐PAEFC graft copolymers with the unique properties of ferrocene and cellulose provide prerequisites for amperometric biosensors and redox‐responsive drug delivery carriers. © 2015 Society of Chemical Industry
Analyzing the higher order structure of proteins with conformer‐selective ultraviolet photodissociation
Authors: Warnke Stephan , von Helden Gert , Pagel Kevin
Published: January 2015

The top‐down approach in protein sequencing requires simple methods in which the analyte can be readily dissociated at every position along the backbone. In this context, ultraviolet photodissociation (UVPD) recently emerged as a promising tool because, in contrast to slow heating techniques such as CID, the absorption of UV light is followed by a rather statistically distributed cleavage of backbone bonds. As a result, nearly complete sequence coverage can be obtained. It is well known, however, that gas‐phase proteins can adopt a variety of different, sometimes coexisting conformations and the influence of this structural diversity on the UVPD fragmentation behavior is not clear. Using ion mobility‐UVPD‐MS, we recently showed that UVPD is sensitive to the higher order structure of gas‐phase proteins. In particular, the cis/trans isomerization of certain proline peptide bonds was shown to significantly influence the UVPD fragmentation pattern of two extended conformers of 11+ ubiquitin. Building on these results, we here provide conformer‐selective UVPD data for 7+ ubiquitin ions, which are known to be present in a much more diverse and wider ensemble of different structures, ranging from very compact to highly extended species. Our data show that certain conformers fall into groups with similar UVPD fragmentation pattern. Surprisingly, however, the conformers within each group can differ tremendously in their collision cross‐section. This indicates that the multiple coexisting conformations typically observed for 7+ ubiquitin are caused by a few, not easily interconvertible, subpopulations.
Intramolecular acyl transfer in peptide and protein ligation and synthesis
Authors: Tailhades Julien , Patil Nitin A. , Hossain Mohammed Akhter , Wade John D.
Published: January 2015

Intramolecular acyl transfer equilibrium in peptides and proteins has stimulated the development of new methodologies for ligation, aggregation suppression or difficult peptide synthesis. Native chemical ligation or aggregation suppression methodologies are based on an X‐to‐N acyl transfer of a peptide chain (X = S, O). The reverse reaction from N‐to‐X has led to exciting developments in solving key synthetic problems such as peptide thioester preparation using Fmoc/tBu strategy. Depending on the target peptide or protein, variations of these methods, which are also based on acyl transfer equilibriums, are now available.

In this review, we provide a detailed overview of development and utility of methodologies in peptide chemistry that are based on the control of intramolecular equilibrium. To this end, we outline the scaffolds that are favorable for acyl transfer, the conditions for controlling both sides of the acyl transfer equilibrium and their applications to peptide and protein chemistry. Additional new methodologies have been developed for the synthesis of difficult peptides such as peptide alcohols or head‐to‐tail cyclic peptides. Promising new applications of intramolecular acyl transfer reactions are also highlighted. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.
Segmentation of low‐cost high efficiency oxide‐based thermoelectric materials
Authors: Hung Le Thanh , Van Nong Ngo , Linderoth Søren , Pryds Nini
Published: January 2015

Thermoelectric (TE) oxide materials have attracted great interest in advanced renewable energy research owing to the fact that they consist of abundant elements, can be manufactured by low‐cost processing, sustain high temperatures, be robust and provide long lifetime. However, the low conversion efficiency of TE oxides has been a major drawback limiting these materials to broaden applications. In this work, theoretical calculations are used to predict how segmentation of oxide and semimetal materials, utilizing the benefits of both types of materials, can provide high efficiency, high temperature oxide‐based segmented legs. The materials for segmentation are selected by their compatibility factors and their conversion efficiency versus material cost, i.e., “efficiency ratio”. Numerical modelling results showed that conversion efficiency could reach values of more than 10% for unicouples using segmented legs based p‐type Ca3Co4O9 and n‐type ZnO oxides excluding electrical and thermal losses. It is found that the maximum efficiency of segmented unicouple could be linearly decreased with increasing the interfacial contact resistance. The obtained results provide useful tool for designing a low‐cost and high efficiency thermoelectric modules based‐oxide materials.
Nitrogen‐doped ZnO obtained by nitrogen plasma treatment
Authors: Wang Dengkui , Zhao Dongxu , Wang Fei , Yao Bin , Shen Dezhen
Published: January 2015

We carried out a nitrogen plasma treatment process to obtain N‐doped ZnO single crystal. The treated sample showed an acceptor related emission located at 3.354 eV when excited by a 325‐nm He–Cd laser at 85 K. Raman spectra revealed the formation of a bond between Zn and N atoms. The surface work function indicated increasing of hole concentration of the N‐plasma‐treated ZnO. By constructing a ZnO‐based homojunction, the I–V curve displayed perfect rectification performance.
Determination of the diffusion lengths of Ga adatoms using GaN stripe profiling
Authors: Rozhavskaya M. M. , Lundin W. V. , Troshkov S. I. , Tsatsulnikov A. F. , Dubrovskii V. G.
Published: January 2015

We present a method for determining the diffusion lengths of Ga adatoms on GaN by combining profiling of the tops of GaN stripes obtained by selective area MOCVD and a diffusion growth model. We deduce very high values of the diffusion lengths on tops of <11–20>‐oriented stripes at 1040 °C which range from 6 μm under nitrogen‐rich to 24 μm under hydrogen‐rich atmosphere in the reactor. The obtained results show in particular that Ga‐catalyzed growth of GaN nanostructures and nanowires should not be limited by Ga influx and thus the exceptional growth rate is anticipated in such cases.
Mapping of inhomogeneity and thermal degradation of Au/Ni/n‐GaN Schottky diodes using scanning internal photoemission microscopy
Authors: Yamamoto Shingo , Kihara Yuhei , Shiojima Kenji
Published: January 2015

We have developed a new mapping technique, termed scanning internal‐photoemission microscopy, to characterize the electrical inhomogeneity of metal‐semiconductor interfaces. We characterized the initial stage of thermal degradation of Au/Ni/n‐GaN Schottky contacts. We found that, upon 400 °C annealing, a partial thermal degradation occurred from a scratch on the dot, where Au atoms diffused to the interface and reacted with GaN. When the top Au layer was partially missing, upon annealing, the Ni surface was oxidized and NiOx/n‐GaN with a small Schottky barrier height was formed. In addition, a thin contamination layer at the interface was clearly observed as a pattern. It was confirmed that this method is a powerful tool to map metal contacts for the investigations of partial thermal degradation, formation of parallel contacts, and inhomogeneity of surface chemistry.
Alkali‐Soluble Polysaccharide, Isolated from Lentinus edodes, Induces Apoptosis and G2/M Cell Cycle Arrest in H22 Cells Through Microtubule Depolymerization
Authors: You Ru‐xu , Liu Jin‐yu , Li Shi‐jun , Wang Liu , Wang Kai‐ping , Zhang Yu
Published: January 2015

The aim of the study was to evaluate the pro‐apoptotic effects of polysaccharides derived from Lentinus edodes and further elucidated the mechanisms of this action. Our results demonstrated that marked morphological changes of apoptosis were observed after treatment of L. edodes polysaccharides [Lentinan (LTN)]. Moreover, LTN‐induced cell apoptosis was characterized by a rapid stimulation of reactive oxygen species production, the loss of mitochondrial membrane potential and an increase in intracellular concentration of Ca2+. In addition, the results of the haematoxylin and eosin and TUNEL assay further confirmed that LTN‐induced apoptosis in vivo. Furthermore, flow cytometry analysis showed that LTN could arrest the cell cycle at G2/M phase, and immunofluorescence showed LTN caused disruption of microtubule. These results suggest that disruption of cellular microtubule network, arrest of the cell cycle at G2/M phase and induction of apoptosis may be one of the possible mechanisms of anti‐tumour effect of LTN. Copyright © 2014 John Wiley & Sons, Ltd.
Vibration suppression for mass‐spring‐damper systems with a tuned mass damper using interconnection and damping assignment passivity‐based control
Authors: Aoki Takashi , Yamashita Yuh , Tsubakino Daisuke
Published: January 2015

This paper considers a vibration suppression control method using feedback for a mass‐spring‐damper system with a tuned mass damper. For vibration suppression, we adopt the interconnection and damping assignment passivity‐based control, whereby the system is transformed to a system with a skyhook damper with an artificial structure matrix. The feedback law includes no accelerometer signal and uses only information on relative displacements and velocities. The proposed control method can simultaneously suppress the influences of the floor vibration and the disturbance force acting on the main body. A guideline for choosing parameters of the desired system is shown. The proposed method can be easily extended to nonlinear cases, which is demonstrated for a nonlinear‐spring case. We also show the input‐to‐state stability property of closed‐loop systems for linear cases and nonlinear cases. Copyright © 2015 John Wiley & Sons, Ltd.
Learned Stochastic Mobility Prediction for Planning with Control Uncertainty on Unstructured Terrain
Authors: Peynot Thierry , Lui Sin‐Ting , McAllister Rowan , Fitch Robert , Sukkarieh Salah
Published: January 2015

Motion planning for planetary rovers must consider control uncertainty in order to maintain the safety of the platform during navigation. Modeling such control uncertainty is difficult due to the complex interaction between the platform and its environment. In this paper, we propose a motion‐planning approach whereby the outcome of control actions is learned from experience and represented statistically using a Gaussian process regression model. This mobility prediction model is trained using sample executions of motion primitives on representative terrain, and it predicts the future outcome of control actions on similar terrain. Using Gaussian process regression allows us to exploit its inherent measure of prediction uncertainty in planning. We integrate mobility prediction into a Markov decision process framework and use dynamic programming to construct a control policy for navigation to a goal region in a terrain map built using an onboard depth sensor. We consider both rigid terrain, consisting of uneven ground, small rocks, and nontraversable rocks, and also deformable terrain. We introduce two methods for training the mobility prediction model from either proprioceptive or exteroceptive observations, and we report results from nearly 300 experimental trials using a planetary rover platform in a Mars‐analogue environment. Our results validate the approach and demonstrate the value of planning under uncertainty for safe and reliable navigation.
Strategies for Water Quality Assessment: A Multiparametric Analysis of Microbiological Changes in River Waters
Authors: Boi P. , Amalfitano S. , Manti A. , Semprucci F. , Sisti D. , Rocchi M. B. , Balsamo M. , Papa S.
Published: January 2015

River waters are classified worldwide in relation to their chemical quality status, which is assessed by the presence of inorganic and organic pollutants. Meanwhile, microbiological quality evaluations are based mainly on the occurrence of pathogens and faecal contaminants, which are indirectly retrieved by standard cultivation methods. In this study, the structural dynamics of a riverine bacterioplankton community were investigated through a quantitative single‐cell approach with the use of flow cytometry for the quantification of total, viable and active cells. Furthermore, catalyzed reporter deposition (CARD)‐FISH was used for the evaluation of Proteobacteria and Cytophaga–Flavobacteria bacterial classes. The aim was to identify the major cytometric and phylogenetic cell groups that most representatively reflect the physical and chemical changes occurring in an upland‐to‐lowland transect along a human‐impacted river (the Foglia River, Italy). The use of CARD‐FISH to obtain cell abundance measurements of specific taxonomic clusters enabled different microbial propagation dynamics along the river transects to be identified. Furthermore, our results highlighted that the multiparametric approach with flow cytometry produces basic microbiological parameters in a reasonable time span that is consistent with the requirements for an early warning monitoring strategy with respect to integrated riverine water quality assessments. Copyright © 2015 John Wiley & Sons, Ltd.
Using distance covariance for improved variable selection with application to learning genetic risk models
Authors: Kong Jing , Wang Sijian , Wahba Grace
Published: January 2015

Variable selection is of increasing importance to address the difficulties of high dimensionality in many scientific areas. In this paper, we demonstrate a property for distance covariance, which is incorporated in a novel feature screening procedure together with the use of distance correlation. The approach makes no distributional assumptions for the variables and does not require the specification of a regression model and hence is especially attractive in variable selection given an enormous number of candidate attributes without much information about the true model with the response. The method is applied to two genetic risk problems, where issues including uncertainty of variable selection via cross validation, subgroup of hard‐to‐classify cases, and the application of a reject option are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Quantifying fair payment after outsourcing – a case study
Authors: Eveleens Laurenz , Kampstra Peter , Verhoef Chris
Published: January 2015

After outsourcing, issues can arise between the outsourcing organization and their third parties about fair payment. In a ceteris paribus situation, fair payment can be determined based on the differences made by the third parties. However, when information technology development is (partly) outsourced to third parties, often, not only does the supplier change, but the development process is also changed. This change of development process alone influences important software metrics, such as time to market, productivity, costs, size, and quality, exactly the metrics that are often used to establish payments. Quantifying the influence of the development process redesign is therefore vital to make a fair assessment of the changes truly caused by the supplier, and thus realistic payment.

In this paper, the influence of the change in the development process on important key performance indicators is quantified using simulation techniques. We use discrete event simulation to analyze the effect on time to market. The techniques we use are illustrated and validated by applying them in a real‐world situation. The techniques can be used to estimate the influence of the business process change both before outsourcing and after the outsourcing has been decided. Our case study helped the organization in their outsourcing by adapting its proposed development process so that the balance between a more formal process and time to market became more in line with their demands. Although the specific numbers will be different per company, other organizations can apply the general principle. Copyright © 2015 John Wiley & Sons, Ltd.
Cross‐layer resource control and scheduling for improving interactivity in Android
Authors: Huh Sungju , Yoo Jonghun , Hong Seongsoo
Published: January 2015

Android smartphones are often reported to suffer from sluggish user interactions due to poor interactivity. This is partly because Android and its task scheduler, the completely fair scheduler (CFS), may incur perceptibly long response time to user‐interactive tasks. Particularly, the Android framework cannot systemically favor user‐interactive tasks over other background tasks since it does not distinguish between them. Furthermore, user‐interactive tasks can suffer from high dispatch latency due to the non‐preemptive nature of CFS. To address these problems, this paper presents framework‐assisted task characterization and virtual time‐based CFS. The former is a cross‐layer resource control mechanism between the Android framework and the underlying Linux kernel. It identifies user‐interactive tasks at the framework‐level, by using the notion of a user‐interactive task chain. It then enables the kernel scheduler to selectively promote the priorities of worker tasks appearing in the task chain to reduce the preemption latency. The latter is a cross‐layer refinement of CFS in terms of interactivity. It allows a task to be preempted at every predefined period. It also adjusts the virtual runtimes of the identified user‐interactive tasks to ensure that they are always scheduled prior to the other tasks in the run‐queue when they wake up. As a result, the dispatch latency of a user‐interactive task is reduced to a small value. We have implemented our approach into Android 4.1.2 running with Linux kernel 3.0.31. Experimental results show that the response time of a user interaction is reduced by up to 77.35% while incurring only negligible overhead. Copyright © 2014 John Wiley & Sons, Ltd.
Research on the water‐holding capacity of pork sausage with acetate cassava starch
Authors: Zhang Fa‐ling , Liang Yan , Tan Cong‐ping , Lu Yan‐min , Cui Bo
Published: January 2015

The water‐holding capacity properties of native and acetate cassava starch were evaluated by freeze–thaw stability and XRD. The results indicated that acetate starch was suitable to be used in sausage for its more stable and lower retrogradation properties compared to native starch. The water‐holding capacity (WHC) of pork sausages with acetate starch was analyzed by NMR T2 relaxometry, magnetic resonance imaging (MRI), differential scanning calorimeter (DSC) and SEM. NMR T2 relaxometry and MRI displayed the significant effect of acetate starch on the water content in sausages. Water‐holding capacity of sausages first increased then decreased with increase of acetate starch. The sausage with 5% w/w acetate starch had the highest content of immobilized water. The result was consistent with the data indirectly obtained from DSC. SEM analysis demonstrated that the sausage with 5% w/w acetate starch had appropriate structure and pore size to hold water. Therefore, we concluded that the sausage with 5% w/w acetate starch had the best WHC property in pork sausages.
Preparation and characterization of octenyl succinic anhydride modified waxy rice starch by dry media milling
Authors: Chen Mian , Yin Tao , Chen Ying , Xiong Shanbai , Zhao Siming
Published: January 2015

Octenyl succinic anhydride (OSA) modified starch from waxy rice was prepared using dry media milling. The characteristics of OSA were investigated by laser particle analyzer, FT‐IR spectroscopy, XRD, and DSC. Degree of substitution (DS) and reaction efficiency (RE) were significantly (p<0.05) influenced by sodium hydroxide concentration, OSA concentration, and mechanical activation time. The suitable processing conditions for preparing octenyl succinic anhydride starch (OSA starch) were determined to be 0.9 g sodium hydroxide per 100 g starch, 4 g OSA per 100 g starch, and 20 h of mechanical activation. Intensities of characteristic peaks at 1724 and 1572 cm−1 in FT‐IR spectrogram increased with DS, which confirmed the successful introduction of ester carbonyl groups into the starch. Size distribution analysis and XRD indicated that the increased DS and RE by dry media milling were attributed to both the decrease of starch granule size and the destruction of the crystalline structure. DSC results showed that the gelatinization temperature of the OSA starch decreased with the increase of DS.
Exploring the characteristics of sago starch films for pharmaceutical application
Authors: Poeloengasih Crescentiana Dewi , Anggraeni Frida Dwi
Published: January 2015

This study investigates the development of sago (Metroxylon sagu) starch‐based edible films for potential hard capsule application. In its conduct, films were made with different amount of starch (9, 10, and 11% w/v) and glycerol (25, 30, 35, and 40% w/w starch) by casting method. The films were characterized by physicochemical, water vapor barrier properties and mechanical properties analysis. The results reveal that sago starch films generally have low solubility in water. It was also found that higher glycerol content leads to decreased tensile strength and increased elongation of the films, while constant glycerol content with higher amylose content results in increased tensile strength and decreased elongation of the films. The increase of water vapor permeability of all films is in line with that of glycerol concentration. Films prepared with 10% of sago starch and 25% of glycerol have the highest tensile strength, the lowest elongation and water vapor permeability, a low moisture content and solubility.
Starch physicochemical properties of waxy proso millet (Panicum Miliaceum L.)
Authors: Chao Guimei , Gao Jinfeng , Liu Rui , Wang Li , Li Cui , Wang Ying , Qu Yang , Feng Baili
Published: January 2015

Starches of four varieties of waxy proso millet were examined in terms of granule morphology, amylose, transparency, retrogradation, pasting, and thermal properties. The starches had great numbers of large polygonal granules with smooth edges, small numbers of small spherical granules, and an average granule size of 6.12 µm. Compared with the starches of non‐waxy proso millet and maize, the starches of the waxy proso millet varieties had lower amylose contents (0.21%) and higher phosphorus contents (1.85 mg/100 g); higher transparency (29.84%) and lower volume percentages of retrogradation (5.01%); higher peak viscosities (3304 cP), trough viscosities (2422 cP) and breakdowns (882 cP), and lower setbacks (267 cP); and lower onset temperatures (To) (69.7°C), peak temperatures (Tp) (75.3°C), final temperatures (Tc) (80.8°C) and enthalpies (ΔH) (10.55 J/g) in their starch gelatinization.
Impacts of powdery mildew on wheat grain sugar metabolism and starch accumulation in developing grains
Authors: Gao Hongyun , Niu Jishan , Yang Xiwen , He Dexian , Wang Chenyang
Published: January 2015

Powdery mildew (Blumeria graminis f. sp. tritici, Bgt) is a destructive disease responsible for yield reductions in wheat. In this study, we quantify the impacts on grain starch accumulation and yield of different wheat cultivars in response to powdery mildew under field conditions. A coupled spectrophotometer assay, enthrone colorimetric method, 2‐DE and MS/MS were used to analyse starch, total soluble sugars (TSS) and metabolic proteins, respectively. Results indicated that AM concentration increased significantly while AP and total starch concentrations decreased with the increase of powdery mildew severity. Powdery mildew suppressed the transformation of sugar to starch in wheat grains at the early infection stage, and there was insufficient substrate for starch synthesis in susceptible cultivars at the later infection stage. A proteomic analysis of metabolic protein showed that plastid α‐1,4‐glucan phosphorylase, sucrose synthase, β‐amylase and glyceraldehyde‐3‐phosphate dehydrogenase related to starch synthesis were all down regulated and hence starch production was accordingly suppressed. Powdery mildew stress appeared to influence expression of starch synthesis‐related enzymes, repressed transformation of sugar to starch, and then inhibited starch (especially AP) synthesis, leading to yield losses.
Effects of coconut oil concentration as a plasticizer and Yucca schidigera extract as a surfactant in the preparation of extruded corn starch films
Authors: Gutiérrez Miguel Chávez , del Carmen Nuñez‐Santiago Maria , Romero‐Bastida Claudia Andrea , Martinez‐Bustos Fernando
Published: January 2015

In this study, extruded films of corn starch (CS) plasticized with coconut oil (CO) (as an alternative plasticizer to glycerol) in the presence of Yucca schidigera extract (YSE) as a surfactant were investigated. It was observed that corn starch films (CSF) plasticized with a lower concentration (15 wt%) of CO showed a better equilibrium of mechanical properties, a higher WVP (5.8 ± 0.2 × 10−9 g m−1 s−1 Pa−1) and percentage of elongation (8 ± 0.5), and a lower Young modulus (99 ± 8 MPa) than those with a higher amount of plasticizer. However, films with Yucca schidigera extract (YSE) as a surfactant showed a decrease in WVP (4.9 ± 0.2 × 10−9 g m−1 s−1 Pa−1), a lower Young modulus (61 ± 2 MPa) and an increase in the percentage of elongation (13 ± 0.4). In order to describe the viscoelastic properties before the extrusion processes in materials in water suspensions and after extrusion process in CSF, rheological and DMTA analysis were performed, showing consistent behaviors for both samples.
Influence of cassia gum on rheological and textural properties of native potato and corn starch
Authors: Gałkowska Dorota , Pycia Karolina , Juszczak Lesław , Pająk Paulina
Published: January 2015

Pasting, rheological, and textural properties of potato and corn starch pastes and gels with different amounts of cassia gum were investigated. Significant effect of cassia gum on pasting characteristic of the starches was found. A decrease and an increase in peak viscosity of potato and corn starch systems, respectively, was observed with increase in cassia gum concentration. The final viscosity, extent of breakdown and setback viscosity were increasing with increasing cassia gum level in both starch systems. The effect of cassia gum on steady flow behavior of the starch pastes differed among the starches. However, all the systems with higher cassia gum concentration exhibited higher shear stress values than their control counterparts. The starch–cassia gum systems were classified as weak gels and their elastic properties were decreasing by the amount of cassia gum. Presence of cassia gum resulted in changes in textural properties of the starch gels, however, the changes were not always consistent with the increase in cassia gum concentration.
Comparison of a dynamic test to analyze the texture of cooked rice with a classic compression–extension test
Authors: Park Inmyoung , Kim Seung‐Hyun , Chung Ill‐Min , Kim In‐Ho , Shoemaker Charles F. , Seo Young‐Su
Published: January 2015

This study was conducted to elucidate the inter‐relationships between the classical compression–extension test and the dynamic rheological test to analyze the texture of cooked rice with two different water ratios. The classical compression–extension test evaluated firmness and adhesiveness, after which the modified balance was calculated. Concurrently, a rheological test, tanδ and |G*| were used to analyze the data. The compression–extension test revealed that the firmness and modified balance increased, while adhesiveness was less affected as the water to rice ratio increased. The modified balances generally increased as grains became shorter, while, |G*| increased and tanδ decreased as the grain became longer. These results were also closely related to the amylose content of each rice variant. Waxy rice (few amylose content) was least firm and highest modified balance, lowest |G*| and highest tanδ, while the results of rice with the highest amylose content showed the opposite results. Principal component analysis revealed that the modified balance, tanδ, firmness and |G*| were located in similar ordinates, indicating that the variables of the two different tests were closely related. Overall, these results demonstrate that some variables in the two different tests provide the same type of information and complementary explanation.
Emulsification properties of enzymatically treated octenyl‐succinic anhydride starch
Authors: Li Zhengsong , Hong Yan , Gu Zhengbiao , Tian Ying , Li Zhaofeng , Cheng Li
Published: January 2015

Octenyl‐succinic anhydride (OSA)‐modified starch was used as an emulsifier in oil‐in‐water emulsions. Multiple analytical techniques, including size‐exclusion chromatography (SEC), confocal laser scanning microscopy (CLSM), and laser diffraction particle size analysis were used to determine the structure and emulsification properties of OSA‐starch. The results indicated that OSA‐starch with a smaller molar mass exhibited improved emulsification properties than its larger counterparts. Furthermore, samples pretreated by enzymatic modification for 25 min showed the best droplet size distribution, improved emulsion stability, and minimum aggregation. It was also determined that stable emulsions were not formed when the average molar mass of OSA‐starch was too small. The emulsion ability of OSA‐starch enzymatically modified for 35 min was found to be a little inferior than that of OSA‐starch upon enzyme treatment for 25 min.