bluuebunny/crossref_metadata_2025 huggingface dataset:
A case of infarction of the region from the declive to the tuber in the cerebellar vermis
Authors: Ogawa Katsuhiko , Suzuki Yutaka , Akimoto Takayoshi , Kamei Satoshi
Published: October 2018

We report a rare case of infarction limited in the region from the declive to the tuber of the posterior lobe in the cerebellar vermis. A 47‐year‐old woman complained of dizziness with acute onset. Mild incoordination of the left upper extremity and mild truncal and gait ataxia was noted. Brain magnetic resonance imaging showed an infarct of the region from the declive to the tuber on the left side. In the posterior lobe, the region from the declive to the tuber is associated with coordination of the hands. The dorsal spinocerebellar tract and the ventral spinocerebellar tract convey unconsciousness proprioceptive signals from the trunk and leg and project to the anterior and posterior lobes in the cerebellar vermis. Symptoms in our patient indicated that the lesion of this region was related to the impairment of these two tracts and incidence of incoordination of the lateral upper extremity.
Prolonged sensory impairment in the perineal region after painless delivery through lumbar epidural anesthesia
Authors: Uemura Maiko T , Mezaki Takahiro , Shibasaki Hiroshi , Takahashi Ryosuke
Published: October 2018

In the painless delivery, the neuronal injury caused by regional anesthesia sometimes causes diagnostic difficulty because of the common findings with lumbosacral injury due to vaginal delivery. We herein report a 36‐year‐old woman presenting with long‐standing cauda equina syndrome due to neurotoxicity of regional anesthetic. Neurological examination revealed the almost symmetrical, heterogeneous sensory deficit mainly in the perineal region, hypoactive quadriceps femoris reflex, decreased anal sphincter reflex, and dermographia. The correct diagnosis is important to support the quality of life of patients.
Derivation and validation of a new score to predict long‐term survival after sudden cardiac arrest
Authors: Gupta Aman , Ladejobi Adetola , Munir Mohammad Bilal , Pasupula Deepak Kumar , Bhonsale Aditya , Kancharla Krishna , Wang Norman C. , Jain Sandeep , Saba Samir
Published: October 2018

Background

There is insufficient information about the long‐term prognosis of sudden cardiac arrest (SCA) survivors. We therefore derived a clinical score (Sudden Cardiac Arrest—mortality score, SCA—MS) that predicts long‐term mortality in patients surviving to hospital discharge and validated it in an independent cohort of SCA survivors.

Methods

A total of 1433 SCA survivors data were collected, who were discharged from the hospitals of the University of Pittsburgh Medical Center between 2002 and 2012. The overall cohort was randomly divided into two near equal cohorts used for the derivation and validation of the SCA—MS, respectively.

Results

The derivation cohort included 768 patients and identified serum potassium level>4.2 mg/dL at admission, the presence of atrial fibrillation at any time during the index hospitalization, and the presence of asystole or pulseless electrical activity as the initial documented rhythm as independent predictors of long‐term mortality. Based on the multivariable modeling result, one point was assigned to each one of these variables to create the SCA—MS that ranged from 0 to 3. In the validation cohort, the SCA—MS was predictive of long‐term mortality (hazards ratio = 1.69, 95% confidence interval 1.50‐1.91, P < 0.001) per 1‐point increment in the SCA—MS.

Conclusions

We describe a new clinical score that predicts long‐term survival after SCA based on serum potassium levels at the admission, presence of atrial fibrillation, and documented rhythm of SCA.
THE SIMPLE ARGUMENT FOR SUBCLASSICAL LOGIC
Authors: Beall Jc
Published: October 2018

This paper presents a simple but, by my lights, effective argument for a subclassical account of logic—an account according to which logical consequence is (properly) weaker than the standard, so‐called classical account. Alas, the vast bulk of the paper is setup. Because of the many conflicting uses of ‘logic’ the paper begins, following a disclaimer on logic and inference, by fixing the sense of ‘logic’ in question, and then proceeds to rehearse both the target subclassical account of logic and its well‐known relative (viz., classical logic). With background in place the simple argument—which takes up less than five pages—is advanced. My hope is that the minimal presentation will help to get ‘the simple argument’ plainly on the table, and that subsequent debate can move us forward.
Relations between the blood lead level and metabolic syndrome risk factors
Authors: Park Yoon‐Jin , Jung Yoomi , Oh Chung‐Uk
Published: October 2018

Objective

This study is to examine the relations between the blood lead level, which has an effect on lipid metabolism in the body, and metabolic syndrome to establish a basic reference for the development of a local community health management program.

Design and Sample

This study is a descriptive correlational study about verifying the relation between the blood lead level and metabolic syndrome risk factors. A total of 2,833 respondents’ data were sampled on the 1st year (2016) data of the 7th Korea National Health and Nutrition Examination Survey conducted by the Korean Centers for Disease Control and Prevention (CDC).

Measures

The data were analyzed to explore blood lead level differences by demographic characteristics, correlations between the blood lead level and metabolic syndrome risk factors using chi‐square test, Mann–Whitney U‐test, Pearson correlation coefficient, and binary logistic regression.

Results

Systolic and diastolic blood pressure, triglycerides (TG), and FBS demonstrated a significant difference by blood lead level (p < 0.001). Systolic and diastolic blood pressure, waist circumference, and FBS and TG levels were positively correlated with blood lead level (p < 0.005), whereas high‐density lipoprotein cholesterol was negatively correlated (r = −0.038, p < 0.005).

Conclusion

This study confirmed that the blood lead level was significantly correlated with all metabolic syndrome variables.
Applying Moral Foundations Theory to Identify Terrorist Group Motivations
Authors: Hahn Lindsay , Tamborini Ron , Novotny Eric , Grall Clare , Klebig Brian
Published: October 2018

Previous research distinguishing terrorist groups has employed categorical schemes that are (1) ideologically broad and ambiguous (e.g., right‐wing versus left‐wing) or (2) focused on single‐issues (e.g., guns, abortion). Broad schemes often fail to clearly distinguish groups’ motivations, and single‐issue schemes provide no coherent theoretical structure for understanding terrorist behavior. To address these limitations, we applied the conceptual framework of moral foundations theory (MFT) to derive a content‐analytic scheme identifying universal instincts we term “moral motivations.” We then applied this scheme to classify descriptions found in the Profiles of Perpetrators of Terrorism in the United States, an open‐sourced dataset providing information on terrorist organizations that committed violence on U.S. soil. Analyses examined how terrorist‐group activities are associated with specific moral motivations in order to distinguish dominant motives among different groups. Results showed that extremist right‐wing, religious, and ethno‐nationalist/separatist ideologies were associated with the binding motivations of loyalty, authority, and purity. Extremist left‐wing and single‐issue ideologies were associated with the individualizing motivations of care and fairness. These findings are discussed regarding the value of using MFT’s motivations to distinguish terrorist groups and how describing their moral motivations might advance efforts to curtail their activities.
Balancing Costs and Benefits of Collaboration in an Ecology of Games
Authors: Hileman Jacob , Bodin Örjan
Published: October 2018

The growth of collaborative approaches to governance has resulted in increasingly complex policy and management landscapes, where actors are presented with ever‐increasing numbers of decision‐making venues they can participate in and actors they can collaborate with. Given that actors face constraints on their capacity to manage actor and venue relationships in such polycentric governance systems, we assume the marginal benefit of yet another relationship should begin to diminish at some level of engagement. Furthermore, we hypothesize that such capacity limitations are not static, but decrease as actors learn, develop skills, and formulate strategies for how to navigate complex polycentric systems more effectively. Drawing on the Ecology of Games framework, this article investigates two Swedish collaborative governance initiatives where a multitude of actors came together to address a range of different, but interrelated, policy issues and management tasks. The empirical findings suggest that actors’ capacities to successfully navigate polycentric governance arrangements increase as they gain experience and develop their networking skills. Our findings imply there is a need to balance increased complexity in polycentric systems with increased capacity, otherwise the overall effect of an ever‐increasing number of venues and actors could be collaborative fatigue and decreased abilities to address diverse governance challenges.
Consciousness and no self?
Authors: Watzl Sebastian
Published: October 2018

Phenomenal consciousness, what it is like for each particular subject, seems to be at the heart of subjectivity and the primary home of the self. But is there in fact a role for the self in phenomenal consciousness? According to the phenomenal no‐self challenge, reflection on the character of phenomenal consciousness reveals no self and no subjectivity. I articulate an argument for this challenge based on the transparency of conscious experience. I then respond to this argument and show that there is an aspect of phenomenal consciousness that the challengers miss. This aspect is active attention. In active attention, in particular in the ability to actively resist distractions, consciousness reveals an agential self: the experiencer is phenomenally manifest as an active power. I further show that the subject’s active role in experience is plausibly present in every form of experience.
Gold Mineralization in Izu Peninsula, Central Japan, during Crustal Extension in Response to Double Subduction
Authors: Hattori Keiko , Kano Ken‐ichi
Published: October 2018

Izu Peninsula in central Japan, the northern tip of the Izu‐Bonin arc, hosts numerous epithermal Au–Ag vein deposits of low‐sulfidation style. All have similar vein textures, mineralogy, and alteration. Geochemical data from fluid inclusions in vein quartz, the mineralogy and mineral chemistry of alteration, and stable isotope data indicate that auriferous hydrothermal activity occurred under subaerial conditions. The K–Ar ages of auriferous vein minerals are <1.5 Ma, indicating that the mineralization took place after extensive submarine volcanism for the host rocks. These observations suggest that Au–Ag mineralization was synchronous with the development of an extensional regime of the Izu block after its collision with the Honshu arc after 1.5 Ma. This collision resulted in the shifting of the Izu block far from the trench to the rear position, and the subduction of the Izu block along the Suruga trough to the west and along the Sagami trough to the east. The reararc position of the Izu block and double subduction resulted in crustal extension, upwelling of asthenospheric mantle, and tholeiitic magmatism reflected by mafic dyke swarms and subsequent monogenetic volcanic activity in the Izu peninsula. The timing of the Au mineralization in the Izu Peninsula during the beginning of lithospheric extension is similar to that of the Sado Au–Ag deposit on Sado island in the Japan Sea. Two mineralization events coincide with extensive tholeiitic mafic volcanism and injections of dyke swarms related to the back‐arc opening of the Japan Sea. The geological setting of the Au–Ag mineralization in Izu and Sado is also similar to that of the epithermal Au–Ag deposits in northern Nevada, where mineralization was contemporaneous with crustal extension and tholeiitic mafic magmatism derived from the asthenospheric mantle. This study suggests that epithermal Au mineralization at shallow crustal depths is a product of large‐scale lithospheric evolution.
Domestic and export performances of French firms
Authors: Bardaji José , Bricongne Jean‐Charles , Campagne Benoît , Gaulier Guillaume
Published: October 2018

The French trade balance deteriorated almost continuously from the late 1990s to the early 2010s. At the macroeconomic level, French export market share deteriorated while domestic sales kept pace with domestic demand. Does this assessment apply to individual firms? Using microlevel data for French industrial firms over the period 2002–12, we explore the link between domestic and export sales. We show that export and domestic sales have a tendency, albeit slight, to move in opposite directions. This may be due to factors such as deliberate strategies to target a specific market or the presence of production constraints. Addressing the resulting endogeneity issue, our analysis shows that a positive demand shock in the domestic market also leads to an increase in exports. In particular, a 10% increase in domestic demand leads to a 4% increase in exports. This complementarity between markets seems to be driven by small firms and could reflect the existence of liquidity constraints. Increased sales in one market could lessen these constraints by facilitating funding for company development in the export market.
Probing Mechanical Properties of Brain in a Tuberous Sclerosis Model of Autism
Authors: Qing Bo , Canovic Elizabeth P. , Mijailovic Aleksandar S. , Jagielska Anna , Whitfield Matthew J. , Lowe Alexis L. , Kelly Elyza H. , Turner Daria , Sahin Mustafa , Van Vliet Krystyn J.
Published: October 2018

Causes of autism spectrum disorders (ASD) are understood poorly, making diagnosis and treatment challenging. While many studies have investigated the biochemical and genetic aspects of ASD, whether and how mechanical characteristics of the autistic brain can modulate neuronal connectivity and cognition in ASD are unknown. Previously, it has been shown that ASD brains are characterized by abnormal white matter and disorganized neuronal connectivity; we hypothesized that these significant cellular-level structural changes may translate to changes in the mechanical properties of the autistic brain or regions therein. Here, we focused on tuberous sclerosis complex (TSC), a genetic disorder with a high penetrance of ASD. We investigated mechanical differences between murine brains obtained from control and TSC cohorts at various deformation length- and time-scales. At the microscale, we conducted creep-compliance and stress relaxation experiments using atomic force microscope(AFM)-enabled indentation. At the mesoscale, we conducted impact indentation using a pendulum-based instrumented indenter to extract mechanical energy dissipation metrics. At the macroscale, we used oscillatory shear rheology to quantify the frequency-dependent shear moduli. Despite significant changes in the cellular organization of TSC brain tissue, we found no corresponding changes in the quantified mechanical properties at every length- and time-scale explored. This investigation of the mechanical characteristics of the brain has broadened our understanding of causes and markers of TSC/ASD, while raising questions about whether any mechanical differences can be detected in other animal models of ASD or other disease models that also feature abnormal brain structure.
A Methodology for Characterizing Representativeness Uncertainty in Performance Indicator Measurements of Power Generating Systems
Authors: Otgonbaatar U. , Baglietto E. , Caffari Y. , Todreas N. E. , Lenci G.
Published: October 2018

In this work, a general methodology and innovative framework to characterize and quantify representativeness uncertainty of performance indicator measurements of power generation systems is proposed. The representativeness uncertainty refers to the difference between a measurement value of a performance indicator quantity and its reference true value. It arises from the inherent variability of the quantity being measured. The main objectives of the methodology are to characterize and reduce the representativeness uncertainty by adopting numerical simulation in combination with experimental data and to improve the physical description of the measurement. The methodology is applied to an industrial case study for demonstration. The case study involves a computational fluid dynamics (CFD) simulation of an orifice plate-based mass flow rate measurement, using a commercially available package. Using the insight obtained from the CFD simulation, the representativeness uncertainty in mass flow rate measurement is quantified and the associated random uncertainties are comprehensively accounted for. Both parametric and nonparametric implementations of the methodology are illustrated. The case study also illustrates how the methodology is used to quantitatively test the level of statistical significance of the CFD simulation result after accounting for the relevant uncertainties.
Forced Response Sensitivity Analysis Using an Adjoint Harmonic Balance Solver
Authors: Engels-Putzka Anna , Backhaus Jan , Frey Christian
Published: October 2018

This paper describes the development and initial application of an adjoint harmonic balance (HB) solver. The HB method is a numerical method formulated in the frequency domain which is particularly suitable for the simulation of periodic unsteady flow phenomena in turbomachinery. Successful applications of this method include unsteady aerodynamics as well as aeroacoustics and aeroelasticity. Here, we focus on forced response due to the interaction of neighboring blade rows. In the simulation-based design and optimization of turbomachinery components, it is often helpful to be able to compute not only the objective values—e.g., performance data of a component—themselves but also their sensitivities with respect to variations of the geometry. An efficient way to compute such sensitivities for a large number of geometric changes is the application of the adjoint method. While this is frequently used in the context of steady computational fluid dynamics (CFD), it becomes prohibitively expensive for unsteady simulations in the time domain. For unsteady methods in the frequency domain, the use of adjoint solvers is feasible but still challenging. The present approach employs the reverse mode of algorithmic differentiation (AD) to construct a discrete adjoint of an existing HB solver in the framework of an industrially applied CFD code. The paper discusses implementational issues as well as the performance of the adjoint solver, in particular regarding memory requirements. The presented method is applied to compute the sensitivities of aeroelastic objectives with respect to geometric changes in a turbine stage.
Effect of Trailing-Edge Flap Deflection on a Symmetric Airfoil Over a Wavy Ground
Authors: Tremblay-Dionne V. , Lee T.
Published: October 2018

The effect of trailing-edge flap (TEF) deflection on the aerodynamic properties and flowfield of a symmetric airfoil over a wavy ground was investigated experimentally. This Technical Brief is a continuation of Lee and Tremblay-Dionne (2018, “Experimental Investigation of the Aerodynamics and Flowfield of a NACA 0015 Airfoil Over a Wavy Ground,” ASME J. Fluids Eng., 140(7), p. 071202) in which an unflapped airfoil was employed. Regardless of the flap deflection, the cyclic variation in the sectional lift Cl and pitching moment Cm coefficients over the wavy ground always persists. The Cm also has an opposite trend to Cl. The flap deflection, however, produces an increased maximum and minimum Cl and Cm with a reduced fluctuation compared to their unflapped counterparts. The Cd increase outperforms the Cl increase, leading to a lowered Cl/Cd of the flapped airfoil.
Optimizing Topology and Gradient Orthotropic Material Properties Under Multiple Loads
Authors: Garland Anthony , Fadel Georges
Published: October 2018

The goal of this research is to optimize an object's macroscopic topology and localized gradient material properties (GMPs) subject to multiple loading conditions simultaneously. The gradient material of each macroscopic cell is modeled as an orthotropic material where the elastic moduli in two local orthogonal directions we call x and y can change. Furthermore, the direction of the local coordinate system can be rotated to align with the loading conditions on each cell. This orthotropic material is similar to a fiber-reinforced material where the number of fibers in the local x and y-directions can change for each cell, and the directions can as well be rotated. Repeating cellular unit cells, which form a mesostructure, can also achieve these customized orthotropic material properties. Homogenization theory allows calculating the macroscopic averaged bulk properties of these cellular materials. By combining topology optimization with gradient material optimization and fiber orientation optimization, the proposed algorithm significantly decreases the objective, which is to minimize the strain energy of the object subject to multiple loading conditions. Additive manufacturing (AM) techniques enable the fabrication of these designs by selectively placing reinforcing fibers or by printing different mesostructures in each region of the design. This work shows a comparison of simple topology optimization, topology optimization with isotropic gradient materials, and topology optimization with orthotropic gradient materials. Finally, a trade-off experiment shows how different optimization parameters, which affect the range of gradient materials used in the design, have an impact on the final objective value of the design. The algorithm presented in this paper offers new insight into how to best take advantage of new AM capabilities to print objects with gradient customizable material properties.
Wear Evaluation of Engine Piston Rings Coated With Dual Layer Hard and Soft Coatings
Authors: Kumar Vikram , Sinha Sujeet Kumar , Agarwal Avinash Kumar
Published: October 2018

The main objective of this investigation is the evaluation of the performance of hard diamond-like-carbon (DLC) or tungsten carbide (WC) and soft (epoxy composite) dual-coatings on the internal combustion (IC) engine piston rings as a protective coating to reduce their wear. The rings were coated with DLC or WC by physical vapor deposition (PVD) method and then soft polymeric composite coating (epoxy/graphene/base oil SN150) was applied on the hard coating. The tribological tests of the dual-coated piston rings were conducted for 3.6 × 105 cycles at 1500 rpm engine speed and 50% rated load of a diesel engine in order to evaluate the wear performance of the piston rings. Scuffing of cylinder liner and piston rings interface was prevented by the application of polymer composites over the hard-coated rings. DLC hard and soft polymer composite dual coating over the top piston ring was found to have the lowest wear rate 1.69 × 10−12 mm3/N·m compared with the wear rate of dual coatings on the middle and lower rings.
A Boundary Layer Approach to Multibody Systems Involving Single Frictional Impacts
Authors: Natsiavas S. , Paraskevopoulos E.
Published: October 2018

A systematic theoretical approach is presented, revealing dynamics of a class of multibody systems. Specifically, the motion is restricted by a set of bilateral constraints, acting simultaneously with a unilateral constraint, representing a frictional impact. The analysis is carried out within the framework of Analytical Dynamics and uses some concepts of differential geometry, which provides a foundation for applying Newton's second law. This permits a successful and illuminating description of the dynamics. Starting from the unilateral constraint, a boundary is defined, providing a subspace of allowable motions within the original configuration manifold. Then, the emphasis is focused on a thin boundary layer. In addition to the usual restrictions imposed on the tangent space, the bilateral constraints cause a correction of the direction where the main impulse occurs. When friction effects are negligible, the dominant action occurs along this direction and is described by a single nonlinear ordinary differential equation (ODE), independent of the number of the original generalized coordinates. The presence of friction increases this to a system of three ODEs, capturing the essential dynamics in an appropriate subspace, arising by bringing the image of the friction cone from the physical to the configuration space. Moreover, it is shown that the classical Darboux–Keller approach corresponds to a special case of the new method. Finally, the theoretical results are complemented by a selected set of numerical results for three examples.
A New Stance Control Knee Orthosis Using a Self-Locking Mechanism Based on a Planetary Gear Train
Authors: Jiménez Gaspar Rodríguez , Salgado David Rodríguez , Sanchez Francisco Javier Alonso , del Castillo Granados Jose María
Published: October 2018

The objective of this work was to design and build a fully mechanical knee orthosis. A knee orthosis should both allow control of the angle of flexion of the knee during the stance phase of the gait cycle and leave the joint free during the swing phase. Knee orthoses are normally used to assist the walking of people suffering from muscle weaknesses or gait pathologies in order to avoid excessive knee flexion during the stance phase. The design of the orthosis proposed in the present work is characterized by allowing the knee to be locked at any angle of flexion during the stance phase, and because the orthosis can be unlocked to allow the joint to be released in the swing phase without the action of any external agent, i.e., without requiring external electrical or electronic systems for the control and performance of the orthosis. These characteristics mean that the design can be adapted to the gait of any user. The proposed design consists of a set of three rods, one attached to the user's thigh, another to the calf, and the other to the foot, connected to each other by a self-locking planetary gear train (PGT).
Form Defects Consideration in Polytope-Based Tolerance Analysis
Authors: Liu Ting , Pierre Laurent , Anwer Nabil , Cao Yanlong , Yang Jiangxin
Published: October 2018

The polytope-based tolerance analysis in design process uses a finite set of constraints to represent specifications and propagates these constraints to any objective point in the Euclidean space. The operations of Minkowski sum and intersection on polytopes are well suited to serial and parallel assemblies. The polytope model has been applied to complex assemblies which contain a large number of joints and geometrical tolerances. However, the previous studies on this model consider toleranced features as surfaces of perfect form. The ignorance of form defects in tolerance analysis would result in a significant loss in accuracy and reliability. In this paper, an extension of the polytope model for tolerance analysis considering form defects is described in which the skin model shape representing the physical shape of the product is adopted to simulate the actual toleranced feature in place of the substitute one used conventionally. The combination of polytope model and skin model shape is expected to inherit many of the advantages of each model, combining easy-to-use tolerance propagation and form defects representation with accuracy guarantees. To demonstrate the method and its respective application, a case study of an assembly is illustrated in detail. The proposed method further enhances the capability of the polytope model in handling form defects and provides more realistic assembly results that approximate the actual assembly conditions for design evaluation.
Aerodynamic Optimization Design of Airfoil Shape Using Entropy Generation as an Objective
Authors: Wang Wei , Wang Jun , Yang Xiao-Pei , Ding Yan-Yan
Published: October 2018

An entropy analysis and design optimization methodology is combined with airfoil shape optimization to demonstrate the impact of entropy generation on aerodynamics designs. In the work herein, the entropy generation rate is presented as an extra design objective along with lift-drag ratio, while the lift coefficient is the constraint. Model equation, which calculates the local entropy generation rate in turbulent flows, is derived by extending the Reynolds-averaging of entropy balance equation. The class-shape function transform (CST) parametric method is used to model the airfoil configuration and combine the radial basis functions (RBFs) based mesh deformation technique with flow solver to compute the quantities such as lift-drag ratio and entropy generation at the design condition. From the multi-objective solutions which represent the best trade-offs between the design objectives, one can select a set of airfoil shapes with a low relative energy cost and with improved aerodynamic performance. It can be concluded that the methodology of entropy generation analysis is an effective tool in the aerodynamic optimization design of airfoil shape with the capability of determining the amount of energy cost.
Estimated Clinical and Economic Impact through Use of a Novel Blood Collection Device To Reduce Blood Culture Contamination in the Emergency Department: a Cost-Benefit Analysis
Authors: Skoglund Erik , Dempsey Casey J. , Chen Hua , Garey Kevin W.
Published: October 2018

Blood culture contamination results in increased hospital costs and exposure to antimicrobials. We evaluated the potential clinical and economic benefits of an initial specimen diversion device (ISDD) when routinely utilized for blood culture collection in the emergency department (ED) of a quaternary care medical center.
Arabinose-Induced Catabolite Repression as a Mechanism for Pentose Hierarchy Control in
Clostridium acetobutylicum
ATCC 824
Authors: Servinsky Matthew D. , Renberg Rebecca L. , Perisin Matthew A. , Gerlach Elliot S. , Liu Sanchao , Sund Christian J.
Published: October 2018

Clostridium acetobutylicum
can ferment a wide variety of carbohydrates to the commodity chemicals acetone, butanol, and ethanol. Recent advances in genetic engineering have expanded the chemical production repertoire of
C. acetobutylicum
using synthetic biology. Due to its natural properties and genetic engineering potential, this organism is a promising candidate for converting biomass-derived feedstocks containing carbohydrate mixtures to commodity chemicals via natural or engineered pathways. Understanding how this organism regulates its metabolism during growth on carbohydrate mixtures is imperative to enable control of synthetic gene circuits in order to optimize chemical production. The work presented here unveils a novel mechanism via transcriptional regulation by a predicted Crh that controls the hierarchy of carbohydrate utilization and is essential for guiding robust genetic engineering strategies for chemical production.
Phylogenetically diverse native systems are more resistant to invasive plant species on Robben Island, South Africa
Authors: Yessoufou Kowiyou , Bezeng Bezeng S. , Gaoue Orou G. , Bengu Thato , van der Bank Michelle
Published: October 2018

Alien invasive species are problematic both economically and ecologically, particularly on islands. As such, understanding how they interact with their environment is necessary to inform invasive species management. Here, we ask the following questions: What are the main functional traits that correlate with invasion success of alien plants on Robben Island? How does phylogenetic structure shape biotic interactions on the island? Using multiple approaches to explore these questions, we found that alien invasive species flower later during the year and for longer period, although flowering phenology was sensitive to alternative starting date. Additionally, we observed that alien invasive species are mostly abiotically pollinated and are generally hermaphroditic whilst their native counterparts rely on biotic pollinators, flower earlier, and are generally dioecious, suggesting that alien invasive and native species use different ecological niches. Furthermore, we found a facilitative interaction between an alien invasive legume and other invasive plants as predicted by the invasional meltdown hypothesis, but this does not influence the phylogenetic structure of plant communities. Finally, phylogenetically diverse set of native species are less receptive to alien invasive species. Collectively, our findings reveal how biotic interactions and phylogenetic relatedness structure alien invasive – native co-existence.
Structural mapping of rock walls imaged with a LiDAR mounted on an unmanned aircraft system
Authors: McAnuff Connor , Samson Claire , Melanson Dave , Polowick Christopher , Bethell Erin
Published: October 2018

Structural mapping of rock walls to determine fracture orientation provides critical geological information in support of mining operations. A helicopter-style UAS (rotor diameter 2 m; take-off mass 35 kg; payload mass 11 kg) instrumented with a high-resolution LiDAR imaged a 75 m long and 10–15 m high series of four adjacent rock walls at the Canadian Wollastonite mine. A point cloud with a density of 484 point/m2 acquired at an angle of incidence of ∼41.7° from a flight altitude of 41.7 m above ground level was selected for structural mapping. The point cloud was first meshed using the Poisson surface reconstruction method and then remeshed to achieve an even element size distribution. Visualization of the remeshed Poisson mesh using a 360° hue–saturation–lightness colour wheel highlighted areas of higher fracture density, whereas visualization using a 180° colour wheel accentuated sliver-like geological features. Two joint sets were identified at 156/82 and 241/86 (strike/dip in degrees). A total of 18 virtual strike measurements and 13 virtual dip measurements were within 10% of manual compass measurements. This study demonstrated that the task of structural mapping of large rock walls can be automated by processing 3D images acquired with a LiDAR mounted on a UAS.
Three-Dimensional Vibration of Fluid-Conveying Laminated Composite Cylindrical Shells with Piezoelectric Layers
Authors: Miramini Seyed Mohammad , Ohadi Abdolreza
Published: October 2018

Cylindrical shells containing flowing fluid have wide applications in various industries. They can be enhanced as smart structures through inclusion of piezoelectric layers, of which the dynamic behavior, however, has not been fully understood. In this paper, the vibration and dynamic analysis of a laminated composite hollow cylinder with piezoelectric layers, subjected to an internal incompressible fluid flow is investigated. It is assumed that the shell is simply supported and the fluid is inviscid and irrotational. The differential equations of the elastic layers, piezoelectric layers, and flowing fluid are derived by the three-dimensional (3D) theory of elasticity, theory of piezoelectricity, and potential flow theory, respectively. A well-known recursive method is applied and extended for the first time to solve the fluid-conveying pipes using 3D theory. This approach makes it possible for the solutions to converge to the exact ones with reasonable computational cost. After validating the results against those available in the literature, the vibrational behavior of the system is examined for various cases with the effect of each parameter investigated. Also, the influence of fluid on the vibration and stability of the shell has been analyzed. The present method can be used to analyze and design hybrid shells conveying fluid with high accuracy and low computational cost.
Analytical Solutions for Large Deflections of Functionally Graded Beams Based on Layer-Graded Beam Model
Authors: Zhou Peng , Liu Ying , Liang Xiaoyan
Published: October 2018

The objective of this paper is to investigate the large deflection of a slender functionally graded beam under the transverse loading. Firstly, by modeling the functionally graded beam as a layered structure with graded yield strength, a unified yield criterion for a functionally graded metallic beam is established. Based on the proposed yielding criteria, analytical solutions (AS) for the large deflections of fully clamped functionally graded beams subjected to transverse loading are formulated. Comparisons between the present solutions with numerical results are made and good agreements are found. The effects of gradient profile and gradient intensity factor on the large deflections of functionally graded beams are discussed in detail. The reliability of the present analytical model is demonstrated, and the larger the gradient variation ratio near the loading surface is, the more accurate the layer-graded beam model will be.
A Comparison Between Fractional-Order and Integer-Order Differential Finite Deformation Viscoelastic Models: Effects of Filler Content and Loading Rate on Material Parameters
Authors: Khajehsaeid Hesam
Published: October 2018

Elastomers or rubber-like materials exhibit nonlinear viscoelastic behavior such as creep and relaxation upon mechanical loading. Differential constitutive models and hereditary integrals are the main frameworks followed in the literature for modeling the viscoelastic behavior at finite deformations. Regular differential operators can be replaced by fractional-order derivatives in the standard models in order to make fractional viscoelastic models. In the present paper, the relaxation behavior of elastomers is formulated both in terms of ordinary (integer-order) and fractional differential viscoelastic models. The derived constitutive equations are fitted to several experimental data to compare their efficiency in modeling the stress relaxation phenomenon. Specifically, a fractional viscoelastic model with one fractional dashpot (FD) is compared with two ordinary models including respectively one and two ordinary dashpots (OD). The models are compared in fitting accuracy, number of required material parameters and also variation of parameters from one compound to another to clarify the effects of filler content and deformation rate. It is shown that, the results of the ordinary model with one OD is not good at all. The fractional model with one FD and the ordinary model with two ODs provide good fittings for all compounds whereas the former uses only three parameters and the latter uses five material parameters. For the fractional model, the order of the Maxwell element and the associated relaxation time approximately remain the same for different compounds of each material at certain loading rates, but it is not the case for the ordinary differential models.
Determination of Random Matrices Dispersion Parameters for Nonparametric Modeling of Stochastic Dynamic Systems with Experimental Verification
Authors: Fatehi Mohammad Reza , Ghanbarzadeh Afshin , Moradi Shapour , Hajnayeb Ali
Published: October 2018

Extraction of random behavior of dynamic systems under the influence of the uncertainty associated with modeling error is a major challenge. In the present study, Random Matrix Theory (RMT) is applied to simulate this type of uncertainty in rotor shafts of high-speed rotordynamic systems. For this purpose, simulation of a random matrix is carried out based on the nonparametric approach followed by the determination of the mean model and dispersion parameters. The mean model is determined by extracting the mechanical and dimensional parameters of 15 rotor shaft samples via exact dimensional measurements and Experimental Modal Analysis (EMA). In this study, presenting the Difference Measure (DM) value, the dispersion parameters of the mass and stiffness of the rotor shafts are exploited. In this research, by minimizing the DM value as an objective function, domain variations and probability density distribution of the uncertain response (rotor shaft natural frequencies in this paper) obtained from the EMA and RMT are coincided simultaneously. The simulation process of a random matrix is fulfilled using the direct Monte Carlo simulation and minimization of the DM parameter is performed using Bee’s Algorithm (BA). It is demonstrated that this swarm intelligence-based algorithm provides an approach to extract optimal and accurate dispersion parameters in RMT implementation. The results show that the calculated dispersion parameters are in good agreement with the experimental data and the BA-based method is effective.
2018 ACM SIGAI student essay contest on artificial intelligence technologies
Authors: Mattei Nicholas
Published: October 2018

Win one of several prizes including $500USD or a chat with a leading AI Researcher. For complete details, including submission requirements, formats, and judges please see: www.tinyurl.com/SIGAIEssay2018
Bacterial Extracellular DNA Production Is Associated with Outcome of Prosthetic Joint Infections
Authors: Zatorska Beata , Arciola Carla Renata , Haffner Nicolas , Segagni Lusignani Luigi , Presterl Elisabeth , Diab-Elschahawi Magda
Published: October 2018

In a retrospective study the association of the production of extracellular DNA (eDNA) in biofilms of clinical staphylococcal isolates from 60 patients with prosthetic joint infection (PJI) and the clinical outcome were investigated. Data from a previous study on eDNA production determined in 24-hour biofilms of staphylococcal isolates (Staphylococcus aureusn=30,Staphylococcus epidermidisn=30) was correlated with the patients’ clinical outcome after 3 and 12 months. Statistical analysis was performed using either the Spearman’s rank correlations test or the t-test. eDNA production ofS. epidermidisin 24-hour biofilms correlated with the patients’ outcome ‘not cured‘ after 12 months. ForS. aureusno such correlation was detected. Thus, eDNA may be a virulence factor ofS. epidermidis.Quantification of eDNA production as a surrogate marker for biofilm formation might be a potential predictive marker for the management of PJI.
Travel beyond Clinical Uses of Fiber Reinforced Composites (FRCs) in Dentistry: A Review of Past Employments, Present Applications, and Future Perspectives
Authors: Scribante Andrea , Vallittu Pekka K. , Özcan Mutlu , Lassila Lippo V. J. , Gandini Paola , Sfondrini Maria Francesca
Published: October 2018

The reinforcement of resins with short or long fibers has multiple applications in various engineering and biomedical fields. The use of fiber reinforced composites (FRCs) in dentistry has been described in the literature from more than 40 years. In vitro studies evaluated mechanical properties such as flexural strength, fatigue resistance, fracture strength, layer thickness, bacterial adhesion, bonding characteristics with long fibers, woven fibers, and FRC posts. Also, multiple clinical applications such as replacement of missing teeth by resin-bonded adhesive fixed dental prostheses of various kinds, reinforcement elements of dentures or pontics, and direct construction of posts and cores have been investigated. In orthodontics, FRCs have been used also for active and passive orthodontic applications, such as anchorage units, en-masse movement units, and postorthodontic tooth retention. FRCs have been extensively tested in the literature, but today the advances in new technologies involving the introduction of nanofillers or new fibers along with understanding the design principles of FRC devices open new fields of research for these materials both in vitro and in vivo. The present review describes past and present applications of FRCs and introduces some future perspectives on the use of these materials.
Experimental Study on Basic Mechanical Properties of Steel Fiber‐Reinforced Siliceous Wet Shotcrete
Authors: Yan Xu , Liu Li-min , Zhang Jin-peng , Li Yan-hui , Wang He
Published: October 2018

In order to solve the problem of low strength and easy cracking of shotcrete in permanent support of tunnel single shell lining, the effects of steel fiber‐reinforced siliceous on mechanical properties of wet shotcrete were investigated by the tests of compressive strength, splitting tensile strength, flexural strength, shear strength, and bending toughness. The strength and the cracking resistance mechanism of steel fiber‐reinforced siliceous wet shotcrete were analyzed by the bending toughness evaluation method. The results show that (1) the steel fiber‐reinforced siliceous can improve splitting tensile, flexural, and shear capacity of the shotcrete, and the maximum growth rates were 77.42%, 72.73%, and 98.31%. The steel fiber plays a major role, and silica fume plays a subsidiarity role. (2) The effect of different types and contents of steel fibers on the compressive strength of wet shotcrete are not obvious. (3) The strengthening effect of shear undaform steel fiber on concrete is obviously better than that of shear flat steel fiber. (4) The flexural toughness of wet shotcrete with the silica content of 10% and the shear steel fiber of 60 kg/m3 is the best.
N-Acetylcysteine for the Treatment of Psychiatric Disorders: A Review of Current Evidence
Authors: Ooi Soo Liang , Green Ruth , Pak Sok Cheon
Published: October 2018

N-acetylcysteine, a sulphur-containing amino acid for the treatment of paracetamol overdose and chronic obstructive pulmonary disease, is a widely available off-the-shelf oral antioxidant supplement in many countries. With the potential to modulate several neurological pathways, including glutamate dysregulation, oxidative stress, and inflammation that can be beneficial to the brain functions, N-acetylcysteine is being explored as an adjunctive therapy for many psychiatric conditions. This narrative review synthesises and presents the current evidence from systematic reviews, meta-analyses, and latest clinical trials on N-acetylcysteine for addiction and substance abuse, schizophrenia, obsessive-compulsive and related disorders, and mood disorders. Good evidence exists to support the use of N-acetylcysteine as an adjunct treatment to reduce the total and negative symptoms of schizophrenia. N-acetylcysteine also appears to be effective in reducing craving in substance use disorders, especially for the treatment of cocaine and cannabis use among young people, in addition to preventing relapse in already abstinent individuals. Effects of N-acetylcysteine on obsessive-compulsive and related disorders, as well as on mood disorders, remain unclear with mixed reviews, even though promising evidence does exist. Larger and better-designed studies are required to further investigate the clinical effectiveness of N-acetylcysteine in these areas. Oral N-acetylcysteine is safe and well tolerated without any considerable adverse effects. Current evidence supports its use as an adjunctive therapy clinically for psychiatric conditions, administered concomitantly with existing medications, with a recommended dosage between 2000 and 2400 mg/day.