bluuebunny/crossref_metadata_2025_split huggingface dataset:
Friction performance of MoDTP and ester‐containing lubricants between CKS piston ring and cast iron cylinder liner
Authors: Wang Weiwei , Li Chengdi , Yang Jie , Shen Yan , Xu Jiujun 
Published: September 2017

AbstractThe friction performance of MoDTP in the existence of ester was investigated. Tribological experiments were performed on reciprocating test rig between CKS piston ring and cast iron cylinder liner. Experimental results show that ester concentration is a key factor that influences the performance of MoDTP, the competitive effects between MoDTP and ester also vary with test temperature and load, and the “V” shape friction coefficient curve is caused by the change in friction surface states. During friction, when the surface roughness decreased and liner surface is covered by the friction layer, fresh metal is less likely to expose to lube oil, which reduces the activity of MoDTP in the existence of high concentration ester.
Movement disorders in genetically confirmed mitochondrial disease and the putative role of the cerebellum
Authors: Schreglmann Sebastian R. , Riederer Franz , Galovic Marian , Ganos Christos , Kägi Georg , Waldvogel Daniel , Jaunmuktane Zane , Schaller Andre , Hidding Ute , Krasemann Ernst , Michels Lars , Baumann Christian R. , Bhatia Kailash , Jung Hans H. 
Published: September 2017

ABSTRACTBackground: Mitochondrial disease can present as a movement disorder. Data on this entity's epidemiology, genetics, and underlying pathophysiology, however, is scarce.Objective: The objective of this study was to describe the clinical, genetic, and volumetric imaging data from patients with mitochondrial disease who presented with movement disorders.Methods: In this retrospective analysis of all genetically confirmed mitochondrial disease cases from three centers (n = 50), the prevalence and clinical presentation of video‐documented movement disorders was assessed. Voxel‐based morphometry from high‐resolution MRI was employed to compare cerebral and cerebellar gray matter volume between mitochondrial disease patients with and without movement disorders and healthy controls.Results: Of the 50 (30%) patients with genetically confirmed mitochondrial disease, 15 presented with hypokinesia (parkinsonism 3/15), hyperkinesia (dystonia 5/15, myoclonus 3/15, chorea 2/15), and ataxia (3/15). In 3 patients, mitochondrial disease presented as adult‐onset isolated dystonia. In comparison to healthy controls and mitochondrial disease patients without movement disorders, patients with hypo‐ and hyperkinetic movement disorders had significantly more cerebellar atrophy and an atrophy pattern predominantly involving cerebellar lobules VI and VII.Conclusion: This series provides clinical, genetic, volumetric imaging, and histologic data that indicate major involvement of the cerebellum in mitochondrial disease when it presents with hyper‐ and hypokinetic movement disorders. As a working hypothesis addressing the particular vulnerability of the cerebellum to energy deficiency, this adds substantially to the pathophysiological understanding of movement disorders in mitochondrial disease. Furthermore, it provides evidence that mitochondrial disease can present as adult‐onset isolated dystonia. © 2017 International Parkinson and Movement Disorder Society
Assessment of prior image induced nonlocal means regularization for low‐dose CT reconstruction: Change in anatomy
Authors: Zhang Hao , Ma Jianhua , Wang Jing , Moore William , Liang Zhengrong 
Published: September 2017

PurposeRepeated computed tomography (CT) scans are prescribed for some clinical applications such as lung nodule surveillance. Several studies have demonstrated that incorporating a high‐quality prior image into the reconstruction of subsequent low‐dose CT (LDCT) acquisitions can either improve image quality or reduce data fidelity requirements. Our proposed previous normal‐dose image induced nonlocal means (ndiNLM) regularization method for LDCT is an example of such a method. However, one major concern with prior image based methods is that they might produce false information when the prior image and the current LDCT image show different structures (for example, if a lung nodule emerges, grows, shrinks, or disappears over time). This study aims to assess the performance of the ndiNLM regularization method in situations with change in anatomy.MethodWe incorporated the ndiNLM regularization into the statistical image reconstruction (SIR) framework for reconstruction of subsequent LDCT images. Because of its patch‐based search mechanism, a rough registration between the prior image and the current LDCT image is adequate for the SIR‐ndiNLM method. We assessed the performance of the SIR‐ndiNLM method in lung nodule surveillance for two different scenarios: (a) the nodule was not found in a baseline exam but appears in a follow‐up LDCT scan; (b) the nodule was present in a baseline exam but disappears in a follow‐up LDCT scan. We further investigated the effect of nodule size on the performance of the SIR‐ndiNLM method.ResultsWe found that a relatively large search‐window (e.g., 33 × 33) should be used for the SIR‐ndiNLM method to account for misalignment between the prior image and the current LDCT image, and to ensure that enough similar patches can be found in the prior image. With proper selection of other parameters, experimental results with two patient datasets demonstrated that the SIR‐ndiNLM method did not miss true nodules nor introduce false nodules in the lung nodule surveillance scenarios described above. We also found that the SIR‐ndiNLM reconstruction shows improved image quality when the prior image is similar to the current LDCT image in anatomy. These gains in image quality might appear small upon visual inspection, but they can be detected using quantitative measures. Finally, the SIR‐ndiNLM method also performed well in ultra‐low‐dose conditions and with different nodule sizes.ConclusionsThis study assessed the performance of the SIR‐ndiNLM method in situations in which the prior image and the current LDCT image show substantial anatomical differences, specifically, changes in lung nodules. The experimental results demonstrate that the SIR‐ndiNLM method does not introduce false lung nodules nor miss true nodules, which relieves the concern that this method might produce false information. However, there is insufficient evidence that these findings will hold true for all kinds of anatomical changes.
The impact of white matter fiber orientation in single‐acquisition quantitative susceptibility mapping
Authors: Lancione Marta , Tosetti Michela , Donatelli Graziella , Cosottini Mirco , Costagli Mauro 
Published: September 2017

The aim of this work was to assess the impact of tissue structural orientation on quantitative susceptibility mapping (QSM) reliability, and to provide a criterion to identify voxels in which measures of magnetic susceptibility (χ) are most affected by spatial orientation effects. Four healthy volunteers underwent 7‐T magnetic resonance imaging (MRI). Multi‐echo, gradient‐echo sequences were used to obtain quantitative maps of frequency shift (FS) and χ. Information from diffusion tensor imaging (DTI) was used to investigate the relationship between tissue orientation and FS measures and QSM. After sorting voxels on the basis of their fractional anisotropy (FA), the variations in FS and χ values over tissue orientation were measured. Using a K‐means clustering algorithm, voxels were separated into two groups depending on the variability of measures within each FA interval. The consistency of FS and QSM values, observed at low FA, was disrupted for FA > 0.6. The standard deviation of χ measured at high FA (0.0103 ppm) was nearly five times that at low FA (0.0022 ppm). This result was consistent through data across different head positions and for different brain regions considered separately, which confirmed that such behavior does not depend on structures with different bulk susceptibility oriented along particular angles. The reliability of single‐orientation QSM anticorrelates with local FA. QSM provides replicable values with little variability in brain regions with FA < 0.6, but QSM should be interpreted cautiously in major and coherent fiber bundles, which are strongly affected by structural anisotropy and magnetic susceptibility anisotropy.
DCE‐ and DW‐MRI as early imaging biomarkers of treatment response in a preclinical model of triple negative breast cancer
Authors: Barnes Stephanie L. , Sorace Anna G. , Whisenant Jennifer G. , McIntyre J. Oliver , Kang Hakmook , Yankeelov Thomas E. 
Published: September 2017

This work evaluates quantitative dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and diffusion‐weighted MRI (DW‐MRI) parameters as early biomarkers of response in a preclinical model of triple negative breast cancer (TNBC). The standard Tofts' model of DCE‐MRI returns estimates of the volume transfer constant (Ktrans) and the extravascular extracellular volume fraction (ve). DW‐MRI returns estimates of the apparent diffusion coefficient (ADC). Mice (n = 38) were injected subcutaneously with MDA‐MB‐231. Tumors were grown to approximately 275 mm3 and sorted into the following groups: saline controls, low‐dose Abraxane (15 mg/kg) and high‐dose Abraxane (25 mg/kg). Animals were imaged at days zero, one and three. On day three, tumors were extracted for immunohistochemistry. The positive percentage change in ADC on day one was significantly higher in both treatment groups relative to the control group (p < 0.05). In addition, the positive percentage change in Ktrans was significantly higher than controls (p < 0.05) on day one for the high‐dose group and on days one and three for the low‐dose group. The percentage change in tumor volume was significantly different between the high‐dose and control groups on day three (p = 0.006). Histology confirmed differences at day three through reduced numbers of proliferating cells (Ki67 staining) in the high‐dose group (p = 0.03) and low‐dose group (p = 0.052) compared with the control group. Co‐immunofluorescent staining of vascular maturity [using von Willebrand Factor (vWF) and α‐smooth muscle actin (α‐SMA)] indicated significantly higher vascular maturation in the low‐dose group compared with the controls on day three (p = 0.03), and trending towards significance in the high‐dose group compared with controls on day three (p = 0.052). These results from quantitative imaging with histological validation indicate that ADC and Ktrans have the potential to serve as early biomarkers of treatment response in murine studies of TNBC.
Automating tasks in protein structure determination with the clipper python module
Authors: McNicholas Stuart , Croll Tristan , Burnley Tom , Palmer Colin M. , Hoh Soon Wen , Jenkins Huw T. , Dodson Eleanor , Cowtan Kevin , Agirre Jon 
Published: September 2017

AbstractScripting programming languages provide the fastest means of prototyping complex functionality. Those with a syntax and grammar resembling human language also greatly enhance the maintainability of the produced source code. Furthermore, the combination of a powerful, machine‐independent scripting language with binary libraries tailored for each computer architecture allows programs to break free from the tight boundaries of efficiency traditionally associated with scripts. In the present work, we describe how an efficient C++ crystallographic library such as Clipper can be wrapped, adapted and generalized for use in both crystallographic and electron cryo‐microscopy applications, scripted with the Python language. We shall also place an emphasis on best practices in automation, illustrating how this can be achieved with this new Python module.
Behavioral responses of pest mole crickets, Neoscapteriscus spp. (Orthoptera: Gryllotalpidae), to selected insecticides
Authors: Kostromytska Olga S , Scharf Michael E , Buss Eileen A 
Published: September 2017

AbstractBACKGROUNDMole crickets (Neoscapteriscus spp.) consume turfgrasses and pasture grasses and uproot plants by their tunneling, which is detrimental to turf aesthetics and decreases forage quantity and quality. Insecticides are frequently used to prevent damage. In typical field trials, damage symptoms, not percent mortality or achieved level of control, are used to assess treatment efficacy. Here, however, laboratory tests assessed the direct effect of key insecticides on Neoscapteriscus mole cricket behavior.RESULTSMole crickets, Neoscapteriscus spp., were able to detect and avoid areas treated with fipronil [formulated product (FP)] and imidacloprid (FP). They tunneled less in sand treated with fipronil and avoided sand treated with fipronil and imidacloprid if given a choice. Mole crickets escaped areas treated with acephate, bifenthrin and fipronil. Bifenthrin and acephate caused increased tunneling during the first 90 min of observation. Fipronil and imidacloprid significantly reduced overall tunneling on treated areas.CONCLUSIONTested insecticides elicited two types of behavioral changes in Neoscapteriscus mole crickets: increased locomotory activity and tunneling [acephate (organophosphate) and bifenthrin (pyrethroid)] and reduced spatial movement [fipronil (phenylpyrazole) and imidacloprid (neonicotinoid)]. These behavioral responses resulted mainly from contact chemoreception and inherent neurotoxicity of the chemicals on Neoscapteriscus mole crickets. © 2017 Society of Chemical Industry
Mimicking of cyproconazole behavior in the presence of Cu and Zn
Authors: Jakl Michal , Fanfrlík Jindřich , Jaklová Dytrtová Jana 
Published: September 2017

RationaleThe frequently used pesticide cyproconazole (Cyp) interacts with the essential elements commonly present in soil which play important roles in various enzymatic processes. These interactions predetermine the Cyp degradation pathways. We suggest a simple experimental and theoretical approach for the prediction of pesticide behavior.MethodsCu/Cyp complexes are explored because of the typical Cu(II) reduction in complexes. Its level and the stability of the Cu–ligand bond depend on the type and the number of the surrounding ligands. Zn/Cyp complexes were compared as it is not expected that Zn(II) will reduce. The complexations were studied by means of electrospray ionization ion trap mass spectrometry and MS/MS collision‐induced dissociations with comparative and explicative density functional theory calculations.ResultsThe Cyp ligand allows both Cu(II) reduction as well as, in specific cases, it protects the higher Cu oxidation state. The reduction is observed in the complexes with solely neutral Cyp where the number of ligands is below 3; a higher number protects the Cu(II) state. The metal atom binds to Cyp via N2 of the triazole ring as well as via π‐electrons of the benzene ring; additional stabilization brings an interaction with the deprotonated OH group.ConclusionsThe character of Cyp interactions with doubly charged metals (Cu(II), Zn(II)) clarified the creation of Cyp metabolites. The phenyl and triazole rings are bound to the metal cation and enable access for the isopropyl ring to be cleaved leaving the common metabolite (CAS Number: 58905‐19‐4).
High‐speed autonomous obstacle avoidance with pushbroom stereo
Authors: Barry Andrew J. , Florence Peter R. , Tedrake Russ 
Published: September 2017

AbstractWe present the design and implementation of a small autonomous unmanned aerial vehicle capable of high‐speed flight through complex natural environments. Using only onboard GPS‐denied sensing and computation, we perform obstacle detection, planning, and feedback control in real time. We present a novel integrated approach to perception and control using pushbroom stereo, which exploits forward motion to enable efficient obstacle detection and avoidance using lightweight processors on an unmanned aerial vehicle. Our use of model‐based planning and control techniques allows us to track precise trajectories that avoid obstacles identified by the vision system. We demonstrate a complete working system detecting obstacles at 120 Hz and avoiding trees at up to 14 m/s (31 MPH). To the best of our knowledge, this is the fastest lightweight aerial vehicle to perform collision avoidance using three‐dimensional geometric information.
Comparison of macroinvertebrate assemblages across a gradient of flow permanence in an agricultural watershed
Authors: Smith C.R. , McCormick P.V. , Covich A.P. , Golladay S.W. 
Published: September 2017

AbstractIn the south‐eastern United States and globally, increasing human water demand coupled with climate change is diminishing stream flows and increasing stream intermittency in many watersheds. We characterized benthic invertebrate assemblages across a stream flow gradient ranging from intermittent to perennial following a multiyear drought by examining the functional traits that can influence assemblage response to drying. We sampled 13 reaches within the Lower Flint River Basin in south‐western Georgia, from September to December 2013. Reaches included perennial, near‐perennial (ceased flowing but maintained a wetted channel during drought), intermittent‐dry (seasonally dry), and intermittent‐frequent (frequently dry). Distinct assemblages were documented across this gradient. Reaches that dried during the drought had a lower richness of aquatic insects, especially Ephemeroptera, Plecoptera, and Trichoptera taxa, partly due to inadequate time for life cycle completion and lack of adaptations to avoid drying. Intermittent reaches also included abundant and unique noninsect taxa such as Gammarus spp. and Isopoda. Projected trends towards increased water demand and drought severity and frequency in the south‐eastern United States will magnify shifts towards dominance by drought‐tolerant taxa as greater portions of stream networks become intermittent.
An iterative mathematical decision model for cloud migration: A cost and security risk approach
Authors: Hosseini Shirvani Mirsaeid , Rahmani Amir Masoud , Sahafi Amir 
Published: September 2017

SummaryThis paper presents an iterative mathematical decision model for organizations to evaluate whether to invest in establishing information technology (IT) infrastructure on‐premises or outsourcing IT services on a multicloud environment. This is because a single cloud cannot cover all types of users’ functional/nonfunctional requirements, in addition to several drawbacks such as resource limitation, vendor lock‐in, and prone to failure. On the other hand, multicloud brings several merits such as vendor lock‐in avoidance, system fault tolerance, cost reduction, and better quality of service. The biggest challenge is in selecting an optimal web service composition in the ever increasing multicloud market in which each provider has its own pricing schemes and delivers variation in the service security level. In this regard, we embed a module in the cloud broker to log service downtime and different attacks to measure the security risk. If security tenets, namely, security service level agreement, such as availability, integrity, and confidentiality for mission‐critical applications, are targeted by cybersecurity attacks, it causes disruption in business continuity, leading to financial losses or even business failure. To address this issue, our decision model extends the cost model by using the cost present value concept and the risk model by using the advanced mean failure cost concept, which are derived from the embedded module to quantify cloud competencies. Then, the cloud economic problem is transformed into a bioptimization problem, which minimizes cost and security risks simultaneously. To deal with the combinatorial problem, we extended a genetic algorithm to find a Pareto set of optimal solutions. To reach a concrete result and to illustrate the effectiveness of the decision model, we conducted different scenarios and a small‐to‐medium business IT development for a 5‐year investment as a case study. The result of different implementation shows that multicloud is a promising and reliable solution against IT on‐premises deployment.
Coupling of Acoustic Cavitation with Dem-Based Particle Solvers for Modeling De-agglomeration of Particle Clusters in Liquid Metals
Authors: Manoylov Anton , Lebon Bruno , Djambazov Georgi , Pericleous Koulis 
Published: September 2017

Abstract
The aerospace and automotive industries are seeking advanced materials with low weight yet high strength and durability. Aluminum and magnesium-based metal matrix composites with ceramic micro- and nano-reinforcements promise the desirable properties. However, larger surface-area-to-volume ratio in micro- and especially nanoparticles gives rise to van der Waals and adhesion forces that cause the particles to agglomerate in clusters. Such clusters lead to adverse effects on final properties, no longer acting as dislocation anchors but instead becoming defects. Also, agglomeration causes the particle distribution to become uneven, leading to inconsistent properties. To break up clusters, ultrasonic processing may be used via an immersed sonotrode, or alternatively via electromagnetic vibration. This paper combines a fundamental study of acoustic cavitation in liquid aluminum with a study of the interaction forces causing particles to agglomerate, as well as mechanisms of cluster breakup. A non-linear acoustic cavitation model utilizing pressure waves produced by an immersed horn is presented, and then applied to cavitation in liquid aluminum. Physical quantities related to fluid flow and quantities specific to the cavitation solver are passed to a discrete element method particles model. The coupled system is then used for a detailed study of clusters’ breakup by cavitation.
Identification and Characterization of Phospholipids with Very Long Chain Fatty Acids in Brewer's Yeast
Authors: Řezanka Tomáš , Kolouchová Irena , Gharwalová Lucia , Palyzová Andrea , Sigler Karel 
Published: September 2017

AbstractYeast lipids and fatty acids (FA) were analyzed in Saccharomyces pastorianus from seven breweries and in the dietary yeast supplement Pangamin. GC–MS identified more than 30 FA, half of which were very‐long chain fatty acids (VLCFA) with hydrocarbon chain lengths of ≥22 C atoms. Positional isomers ω‐9 and ω‐7 were identified in FA with C18–C28 even‐numbered alkyl chains. The most abundant ω‐7 isomer was cis‐vaccenic acid. The structure of monounsaturated FA was proved by dimethyl disulfide adducts (position of double bonds and cis geometric configuration) and by GC–MS of pyridyl carbinol esters. Ultra‐high performance liquid chromatography‐tandem mass spectrometry with negative electrospray ionization identified the phospholipids phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine, with more than 150 molecular species. Wild‐type unmutated brewer's yeast strains conventionally used for the manufacture of food supplements were found to contain VLCFA.
Circadian Rhythms, Sleep, and Cognitive Skills: Evidence From an Unsleeping Giant
Authors: Giuntella Osea , Han Wei , Mazzonna Fabrizio 
Published: September 2017

AbstractThis study analyzes the effects of sleep duration on cognitive skills and depression symptoms of older workers in urban China. Cognitive skills and mental health have been associated with sleep duration and are known to be strongly related to economic behavior and performance. However, causal evidence is lacking, and little is known about sleep deprivation in developing countries. We exploit the relationship between circadian rhythms and bedtime to identify the effects of sleep using sunset time as an instrument. Using the Chinese Health and Retirement Longitudinal Study, we show that a later sunset time significantly reduces sleep duration and that sleep duration increases cognitive skills and eases depression symptoms of workers aged 45 years and older. The results are driven by employed individuals living in urban areas, who are more likely to be constrained by rigid work schedules. We find no evidence of significant effects on the self-employed, non-employed, or farmers.