bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracting Customer Perceptions of Product Sustainability From Online Reviews
Authors: El Dehaibi Nasreddine , Goodman Noah D. , MacDonald Erin F.
Published: September 2019

In order for a sustainable product to be successful in the market, designers must create products that are not only sustainable in reality but are also sustainable as perceived by the customer—and reality versus perception of sustainability can be quite different. This paper details a design method to identify perceptions of sustainable features (PerSFs) by collecting online reviews, manually annotating them using crowdsourced work, and processing the annotated review fragments with a natural language machine learning algorithm. We analyze all three pillars of sustainability—social, environmental, and economic—for positive and negative perceptions of product features of a French press coffee carafe. For social aspects, the results show that positive PerSFs are associated with intangible features, such as giving the product as a gift, while negative PerSFs are associated with tangible features perceived as unsafe, like sharp corners. For environmental aspects, positive PerSFs are associated with reliable materials like metal while negative PerSFs are associated with the use of plastic. For economic aspects, PerSFs mainly serve as a price constraint for designers to satisfy other customer perceptions. We also show that some crucial sustainability concerns related to environmental aspects, like energy and water consumption, did not have a significant impact on customer sentiment, thus demonstrating the anticipated gap in sustainability perceptions and the realities of sustainable design, as noted in previous literature. From these results, online reviews can enable designers to extract PerSFs for further design study and to create products that resonate with customers' sustainable values.
A Data-Driven Approach to Product Usage Context Identification From Online Customer Reviews
Authors: Suryadi Dedy , Kim Harrison M.
Published: September 2019

This paper proposes a data-driven methodology to automatically identify product usage contexts from online customer reviews. Product usage context is one of the factors that affect product design, consumer behavior, and consumer satisfaction. The previous works identify the usage contexts using the survey-based method or subjectively determine them. The proposed methodology, on the other hand, uses machine learning and Natural Language Processing tools to identify and cluster usage contexts from a large volume of customer reviews. Furthermore, aspect sentiment analysis is applied to capture the sentiment toward a particular usage context in a sentence. The methodology is implemented to two data sets of products, i.e., laptop and tablet. The result shows that the methodology is able to capture relevant product usage contexts and cluster bigrams that refer to similar usage context. The aspect sentiment analysis enables the observation of a product’s position with respect to its competitors for a particular usage context. For a product designer, the observation may indicate a requirement to improve the product. It may also indicate a possible market opportunity in a usage context in which most of the current products are perceived negatively by customers. Finally, it is shown that overall rating might not be a strong indicator for representing customer sentiment toward a particular usage context, due to the moderate linear correlation for most of the usage contexts in the case study.
A Comparative Evaluation of Supervised Machine Learning Classification Techniques for Engineering Design Applications
Authors: Sharpe Conner , Wiest Tyler , Wang Pingfeng , Seepersad Carolyn Conner
Published: September 2019

Supervised machine learning techniques have proven to be effective tools for engineering design exploration and optimization applications, in which they are especially useful for mapping promising or feasible regions of the design space. The design space mappings can be used to inform early-stage design exploration, provide reliability assessments, and aid convergence in multiobjective or multilevel problems that require collaborative design teams. However, the accuracy of the mappings can vary based on problem factors such as the number of design variables, presence of discrete variables, multimodality of the underlying response function, and amount of training data available. Additionally, there are several useful machine learning algorithms available, and each has its own set of algorithmic hyperparameters that significantly affect accuracy and computational expense. This work elucidates the use of machine learning for engineering design exploration and optimization problems by investigating the performance of popular classification algorithms on a variety of example engineering optimization problems. The results are synthesized into a set of observations to provide engineers with intuition for applying these techniques to their own problems in the future, as well as recommendations based on problem type to aid engineers in algorithm selection and utilization.
Knowledge-Assisted Optimization for Large-Scale Design Problems: A Review and Proposition
Authors: Wu Di , Gary Wang G.
Published: September 2019

Practicing design engineers often have certain knowledge about a design problem. However, in the last decades, the design optimization community largely treats design functions as black-boxes. This paper discusses whether and how knowledge can help with optimization, especially for large-scale optimization problems. Existing large-scale optimization methods based on black-box functions are first reviewed, and the drawbacks of those methods are briefly discussed. To understand what knowledge is and what kinds of knowledge can be obtained and applied in a design, the concepts of knowledge in both artificial intelligence (AI) and in the area of the product design are reviewed. Existing applications of knowledge in optimization are reviewed and categorized. Potential applications of knowledge for optimization are discussed in more detail, in hope to identify possible directions for future research in knowledge-assisted optimization (KAO).
Infusion Jet Flow Control in Neonatal Double Lumen Cannulae
Authors: Rasooli Reza , Yıldız Yahya , Jamil Muhammad , Pekkan Kerem
Published: September 2019

Clinical success of extracorporeal membrane oxygenation (ECMO) depends on the proper venous cannulation. Venovenous (VV) ECMO is the preferred clinical intervention as it provides a single-site access by utilizing a VV double lumen cannula (VVDLC) with a higher level of mobilization and physical rehabilitation. Concurrent venous blood drainage and oxygenated blood infusion in the right atrium at the presence of the cannula makes the flow dynamics complex where potential mixing of venous and oxygenated blood can drastically decrease the overall performance of ECMO. There are no studies focusing on the neonatal and pediatric populations, in which the flow related effects are critical due to the small atrium size. In this study, fluid dynamics of infusion outflow jet for two commercially available neonatal VVDLC is analyzed using particle image velocimetry (PIV). Moreover, six new designs are proposed for the infusion channel geometry and compared. Important flow parameters such as flow turning angle (FTA), velocity decay, potential core, and turbulent intensity are investigated for the proposed models. The experiments showed that the outflow parameters of commercial cannulae such as FTA are strongly dependent on the operating Re number. This may result in a drastic efficiency reduction for cannula operating at off-design flow conditions. Moreover, the infusion outlet tip structure and jet internal guiding pathway (JIGP) was observed to greatly affect the outflow flow features. This is of paramount importance since the anatomical positioning of the cannula and the infusion outlet is strongly dependent on the outflow properties such as FTA.
Liquid State Machine to Generate the Movement Profiles for the Gait Cycle of a Six Degrees-of-Freedom Bipedal Robot in a Sagittal Plane
Authors: Franco-Robles Jesús , De Lucio-Rangel Alejandro , Camarillo-Gómez Karla A. , Pérez-Soto Gerardo I. , Martínez-Prado Miguel A.
Published: September 2019

In this paper, an approach based on a liquid state machine (LSM) to compute the movement profiles to achieve a gait pattern subject to different variations in its trajectory is presented. At the same time, the position of the zero moment point (ZMP) to determine the stability of the six degrees-of-freedom (6DOF) bipedal robot in the sagittal plane during the gait cycle is calculated. The system is constructed as a supervised machine learning model. The time series of the oscillating foot trajectory obtained by direct kinematics with a multilayer perceptron neural network (MLP), to strengthen the kinematic model, is considered as input values for training. The target movement profiles are acquired of a human gait cycle analysis in three different scenarios: normal gait, climbing stairs, and descending stairs. In training, this model also gets the trajectories of the ZMP position during the gait cycle, as target time series. The LSM formed by spiking neurons, considered as third-generation neural networks, is compared in the accuracy of prediction, by the dynamic time warping (DTW) technique and correlation analysis, against the human gait analysis database. With this neuronal system, the joint positions to generate a trajectory of the oscillating foot and the ZMP position of the bipedal in the sagittal plane in different scenarios are obtained, proving the robustness of the LSM.
Stokes Slip Flow in Channel Bend
Authors: Wang C. Y.
Published: September 2019

Using intrinsic coordinates, the slip flow in a minute meandering channel is studied by perturbation about the small ratio of curvature to inverse half gap width. The exact solution for an annulus shows this ratio can be as large as 0.5 with less than 1% error. Velocity slip on the walls and the pressure drop depend on the slip factor. Formula for the pressure drop in a channel with a single bend is derived.
Parameter Identification in a Magnetic Suspension Force Transduction System
Authors: Stambaugh Corey , Abbott Patrick , Vlajic Nicholas
Published: September 2019

In force transduction systems, magnetic suspension can be used to facilitate the measurement of a force acting between two objects in different environments, namely, between the force transducer in one environment and the test object in another environment. In the past, it has been employed in densimetry and equations-of-state measurements of fluids and gases. An instrument being constructed at the National Institute of Standards and Technology (NIST), referred to as the magnetic suspension mass comparator (MSMC), also employs force transduction between two environments to provide a direct means of vacuum-to-air mass dissemination. Within this work, we discuss the identification, through a combination of finite element analysis and experimental measurements, of the system parameters used for feedback control of the suspension. A Hall effect magnetometer is used to determine the position of the suspended object. Emphasis is placed on experimentally and numerically characterizing the magnetic field and its appropriate gradients to determine the set point of operation. The information presented here is useful for a variety of applications that utilize magnetic suspension for force transduction.
Numerical Investigations of Gas–Liquid Two-Phase Flow in a Pump Inducer
Authors: Mansour Michael , Parikh Trupen , Engel Sebastian , Thévenin Dominique
Published: September 2019

Inducers show generally a positive influence on the performance of centrifugal pumps in the two-phase regime, since they produce more uniform mixtures and increase the pressure before the impeller. However, the effect is much more pronounced in part-load compared to overload conditions. In this study, the air–water two-phase flow behavior in a pump inducer was numerically investigated. The main objectives were to clarify the effect of the inducer, the effective operating range, and to examine flow mixing. Several flow conditions were studied, covering part-load, optimal, and overload pumping conditions, together with different relevant gas volume fractions (1%, 3%, and 5%). The simulations were performed using a transient setup and a moving-mesh approach. Two-phase air–water interactions were modeled by the volume of fluid (VOF) method. After checking the proper discretization in space and time, the model was validated against experimental results, revealing excellent agreement. The numerical analysis was able to explain different effects of inducers in part-load and overload conditions. Under overload conditions, the flow separates, leading to the generation of axial vortices and to a negative pressure change across the inducer; additionally, the residence time is reduced, hindering mixing. These vortices are intensified as the gas volume fraction increases, reducing further the pressure downstream of the inducer. This is the reason why inducers can mainly be used in part-load and near optimal conditions in order to improve pumping of two-phase flows.
Hydrostatic Journal Bearing With Porous Pads and Improved Properties
Authors: Shaw Dein , Hsieh Hui-An
Published: September 2019

A hydrostatic journal bearing with porous pads to improve its performance is designed. The porous pads, which are embedded in recesses of the hydrostatic journal bearing, not only allow lubricant to flow through them but also form a complete cylindrical surface with the bearing land. The load capacity of the hydrostatic bearing is thus maintained and the hydrodynamic effects strengthened. A theoretical model of the porous pads bearing is tested with the simulation software, and the parameters that critically affect the bearing performance are studied. Thus, the results obtained indicate that the porous pads bearing has higher load capacity and higher stiffness than a typical hydrostatic bearing with lower friction and lower end flow rate at high rotating speed.
Research on Mixed Lubrication Problems of the Non-Gaussian Rough Textured Surface With the Influence of Stochastic Roughness in Consideration
Authors: Gu Chunxing , Meng Xianghui , Wang Shuwen , Ding Xiaohong
Published: September 2019

In order to find the effects of surface topography on the tribological properties of the rough textured surfaces, an improved mixed lubrication model allowing specifying the standard deviation, the skewness, and the kurtosis was developed. In this model, by considering the non-Gaussian properties of rough surfaces, an improved average flow model was combined with a modified statistical elastoplastic asperity contact model. The performances of the slider bearings with two arrays of anisotropic textures were studied in terms of Stribeck curves. It appears that the tribological properties of the anisotropic textures are sensitive to the sliding direction. Meanwhile, the surfaces with more negative skewness or the lower kurtosis can obtain better tribological performances related to friction and wear.
The Uncertainty in Solutions to Implicit Equation Systems
Authors: Terry Beck B. , Peterman Robert J. , Wu Chih-Hang John
Published: September 2019

This paper introduces a general methodology for determining the uncertainty of the solution to implicit systems of equations. Equation systems of this type arise from many practical applications, including the analysis of pipe networks, and in the implementation of complex numerical (finite difference or finite element) solution algorithms. The procedure is applicable to either linear or nonlinear equation systems, and does not require any specific algorithm for solution to the equation system itself. A general sensitivity matrix is constructed from an implicit sensitivity analysis of the equation system. This overall sensitivity matrix is expressed in terms of input and output sensitivity matrices, which represent the sensitivity of the equation system to changes in the independent (parameters) and dependent (calculated) variables, respectively. A vector representing the root-mean-square (RMS) uncertainty of the solution variables in the equation system is then given as a function of the given uncertainty in the input parameters. Two specific examples are presented to illustrate the practical application of the technique: (1) An example from fluid mechanics evaluating the uncertainty in solutions to a pipe network problem and (2) an example evaluating the uncertainty of a thermistor calibration and measurement problem.
Predicting Performance of Double-Pipe Parallel- and Counter-Flow Heat Exchanger Using Fuzzy Logic
Authors: Sridharan M.
Published: September 2019

The heat exchanger is a device in which heat transfer takes place between two fluids at different temperatures. Among various classifications of heat exchangers, parallel and counter flow types are used widely in many industrial applications. This paper presents two fuzzy logic expert systems (FLESs), one for parallel-flow and another for counter-flow double-pipe heat exchanger (DPHE). Such FLESs are capable of predicting the exit temperature of heat carrier fluids and its effectiveness in an accurate manner. In total, 96 sets of experiments have been conducted for parallel and counter flow types under different combinations of the mass flow rate. The performance accuracy of the fuzzy logic expert system is measured by comparing fuzzy predicted results with experimental data sets. Such a comparison indicates a good agreement between experimental data sets and fuzzy predicted results. The accuracy of the parallel-flow FLES in predicting the exit temperature and its effectiveness is 92.78% and 95%, respectively. The accuracy of the counter-flow FLES in predicting the exit temperature and its effectiveness is 94.28% and 95.5%, respectively.
A Preliminary Risk Assessment on the Development of a Small-Scaled Floating Power Plant
Authors: Park Sung-In , Kim Su Kyeong , Kim Sang Jin , Paik Jeom Kee
Published: September 2019

This paper introduces a preliminary risk assessment method carried out on a newly developed floating power plant. The small-scale floating power plant has been developed to provide electric power for areas on demand, and this is a kind of a new concept system which is not clearly classified in the maritime industry. To grant the feasibility for this novel system design, a set of risk assessment activities is essentially required, and in this context, a hazard identification (HAZID) study is conducted at the very early stage of the plant design. The aims of this HAZID study are to verify the inherent safety of the initial plant design and to provide any recommendations on the next design stages. For this purpose, the potential hazards are identified in view of personnel, structural, and asset effects in association with the operation of the power plant and all the identified hazards and relevant risks are assessed with the defined criteria using a simple risk matrix. As a result, the risk or safety level of the conceptual plant design is estimated, and some design changes are suggested to give a better balance between the safety and the cost of the plant system. Overall, this paper shows how the primitive risk assessment techniques are utilized as a practical engineering tool in the development of the marine system.
Effect of Graphite Content on Cu–Ni–Graphite Composite for Use as Switch Slide Baseplate Materials Sliding Against U75V Steel
Authors: Wang Yiran , Gao Yimin , Takahashi Jun , Wan Yi , Zhang Yunqian , Xiao Bing , He Xiangdong , Li Jun
Published: September 2019

The rapid development of high-speed railways necessitates the development of new materials for switch slide baseplates. In this study, a Cu–Ni–graphite composite, containing 1 wt% to 6 wt% graphite and prepared by powder metallurgy, was used as a potential material. Pin-on-disk wear tests were conducted to measure the sliding friction of the Cu–Ni–graphite composite against U75 V steel. The results showed that the friction coefficients gradually decreased when the graphite content in the composite ranged from 1 wt% to 4 wt% in the composite. When the graphite content was 4 wt%, the friction coefficient reached the minimum value (0.153). When the graphite content was low (1 wt% to 4 wt%), the primary wear mechanism was microcutting. An increased graphite content facilitated the generation of lubricating films and decreased the wear damage. As the graphite content increased from 4 wt% to 6 wt%, the friction coefficients also increased. The variation in the wear volume rate had the same tendency as the friction coefficient. When the graphite content exceeded 4 wt%, the primary wear mechanism was delamination and fatigue wear. Due to the tendency to form cracks on the subsurface and the plentiful generation of the spalled pits, the graphite fragments could not completely form lubricating films but separated as wear debris. The lubricating films existing on the U75 V steel were in proportion to the graphite content in the composite. The wear weight loss of the U75 V steel exhibited a reduction with increasing graphite content.
Rigid and Flat Foldability of a Degree-Four Vertex in Origami
Authors: Zimmermann Luca , Stanković Tino
Published: September 2019

Rigid foldability is the property of an origami that folds continuously from an unfolded to a folded state without deformation in its facets. Although extensively researched, there exist no intrinsic conditions for the rigid foldability of a degree-four vertex, which is the simplest possible origami building block that folds nontrivially. In this paper, we derive a necessary and sufficient condition for the rigid foldability of a degree-four vertex and show that it can be reduced to a purely sufficient condition, which is equivalent to a known condition from the realm of spherical mechanisms. The implications of these conditions are discussed, which reveals the connection between rigid and flat foldability, the two most important mathematical notions in origami. In practice, this work further contributes to the design synthesis and analysis of deployable structures, in which the mechanics of degree-four vertices is omnipresent.
Bio-Inspired Locomotion of Circular Robots With Diametrically Translating Legs
Authors: Steffan Eric , Pal Sudeshna , Das Tuhin
Published: September 2019

In this paper, we develop an analytical framework for designing the locomotion of mobile robots with a circular core and equispaced diametral legs, each having a radial translational degree of freedom. The mechanism has resemblance with certain cellular locomotion. The robot travels by radial actuation of the legs in a sequential and synchronized manner. Two elementary regimes of motion are first designed using the geometry and degrees of freedom of the mechanism. Overall motion of the robot is generated by repeated switching between the two regimes. The paper addresses both kinematics and kinetics of the mechanism, enabling the prediction of trajectories and computation of constraint as well as actuation forces. Simulation results are provided in support of the theory developed.
Entropy Generation Minimization in a Parabolic Trough Collector Operating With SiO2–Water Nanofluids Using the Genetic Algorithm and Artificial Neural Network
Authors: Okonkwo Eric C. , Adun Humphrey , Babatunde Akinola A. , Abid Muhammad , Ratlamwala Tahir A.H.
Published: September 2019

The paper presents an entropy generation minimization study for a solar parabolic trough collector (PTC) operating with SiO2–water nanofluid using a genetic algorithm (GA) and artificial neural network (ANN). The characteristic variables of nanoparticle volumetric concentration (0.01 ≤ φ ≤ 0.05), mass flow rate (0.1 ≤ ṁ ≤ 1.1 kg/s), and inlet temperatures (350–550 K) are used to analyze the rate of entropy generated in the PTC. GA is used in optimizing the entropy generation rate for the specified parameters, while ANN is used for predicting and observing the behavior of these parameters on the rate of entropy generation in the collector. The optimum ANN model is derived with one hidden layer of 18 neurons when training the input variables for the entropy generation predictions. The optimal mean square error used as a performance validation of the model is 0.02288 for training and 0.0282 for testing with an R2 value of 0.9999. The impact of the defined parameters on the entropy generation rate is presented in Sec. 5. It is concluded that machine learning techniques can be an efficient tool for predicting the rate of entropy generation in a collector within the constraint of the defined parameters.
Analysis of Gas-Liquid Cylindrical Cyclone Separator With Inlet Modifications Using Fluid–Structure Interaction
Authors: Kolla Srinivas Swaroop , Mohan Ram S. , Shoham Ovadia
Published: September 2019

The gas-liquid cylindrical cyclone (GLCC©, The University of Tulsa, 1994) is a simple, compact, and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. An in-depth evaluation of specific design modifications and their effect on safety and structural robustness are carried out in this study using finite element analysis (FEA). Fluid–structure interaction (FSI) analysis is also carried out using the results of computational fluid dynamics (CFD) aimed at investigating the effect of fluid flow on the inlet section structural integrity. The selected design modifications are based on feasibility of GLCC© manufacturing and assembly for field applications. Different case studies incorporating sustained GLCC© internal pressure, dead weight loading, forces generated because of slug flow and high temperatures are analyzed and presented in this paper. The concept of holes cut out in baffle has been effective with no stresses or deformation in the baffle area. FSI simulation of slug flow has proved that FEA direct loading case studies are far more conservative.
Development of a Standalone, Liquid Fuelled Miniature Power Generation System
Authors: Bharadwaz N. K. Aditya , Jain Naman , Arghode Vaibhav Kumar
Published: September 2019

This paper aims at developing a novel mesoscale combustion-based thermoelectric power generator as an alternate to the electrochemical batteries. Most of the micro and mesoscale combustors investigated till date are based on external fuel and air supply systems, which may not be beneficial for a practical system. The proposed design is a standalone system which makes use of the heat conducted through the combustor walls, as an energy source to evaporate the liquid fuel stored in a surrounding tank and supply the vaporized fuel to the combustor. The high momentum fuel (vapor) jet is designed to entrain the ambient air in appropriate proportion so as to form a combustible mixture. The fuel/air mixture is fed to a mesoscale combustor and the flame is stabilized by facilitating hot gas recirculation regions. The hot combustion products then flow over a ceramic plate on the other side of which the hot side of a thermoelectric module (TEM) is attached, while ensuring a near uniform temperature, to generate electricity. The cold side of the TEM is maintained at relatively lower temperature and the heat is designed to be rejected using fins to the ambient. The prototype is designed to produce an electrical power output of 12 W with an overall efficiency of about 2.4% (heat load of 500 W) and endurance of 1.5 h in a single fuel refill. The paper presents detailed description of the constituent components and the CFD analysis which evaluates the performance of the system.
Integrating an Analytical Uncertainty Quantification Approach to Multi-Scale Modeling of Nanocomposites
Authors: Acar Pınar
Published: September 2019

The present study addresses the integration of an analytical uncertainty quantification approach to multi-scale modeling of single-walled carbon nanotube (SWNT)-epoxy nanocomposites. The main highlight is the investigation of the stochasticity of nanotube orientations, and its effects on the homogenized properties. Even though the properties of SWNT-epoxy nanocomposites are well-studied in the literature, the natural stochasticity that arises from the nanotube orientations has not been observed. To understand the effects of the variability in SWNT orientations to material properties of interest, an analytical uncertainty quantification algorithm is utilized. The analytical scheme computes the propagation of the orientational uncertainty to the volume-averaged properties with a linear solution and uses the transformation of random variables principle to obtain the variations in non-linear properties. The results indicate that the uncertainty propagation affects the macro-scale properties, including stiffness, thermal expansion, thermal conductivity, and natural frequencies.
Rising to the Challenge of Our Rival: Promoting Rivalry at Sam Houston State University Through Campus Recreation
Authors: Lee Jason W. , Zapalac Ryan K. , Gregg Elizabeth A. , Godfrey Courtney
Published: September 2019

Rivalries are a powerful promotional tool that can help drive identification with a brand, attendance at sports events, and subsequent consumer spending. While rivalries often benefit the participating athletic departments directly, there are other peripheral benefits that institutions can take advantage of. For instance, campus recreation departments can use the rivalry to help boost participation and provide additional psychic income benefits. This case focuses on two NCAA Football Championship Subdivision rivals and the ways in which the branding of their annual football contest, the Battle of the Piney Woods, can be best leveraged by other programs in the university, namely campus recreation. A sample scenario of a relatively new recreational sports employee is provided along with promotional elements and background for the universities and the Battle of the Piney Woods event. The reader is challenged to devise strategies that can best tie the Battle of the Piney Woods rivalry to the promotion of recreational sports offerings. The goal of such an exercise is to have one examine how large inter-institutional rivalries can also benefit other sport organizations that are within the university but are not necessarily just in the athletic department.
Puck Drop in the Pacific Northwest: Building Brand Equity for a New Professional Sport Franchise
Authors: Davies Melissa , Naraine Michael L. , Mastromartino Brandon
Published: September 2019

This case asks participants to take on the role of a brand consultant, working for the fictional brand management firm, BrandNew, to advise on the branding of a new National Hockey League (NHL) franchise. The consultant will need to identify the strengths and weaknesses in the brand equity for three previous NHL expansion or relocation teams (i.e., Vegas Golden Knights, Winnipeg Jets, Carolina Hurricanes) in order to understand what goes into selecting an effective team name, color scheme, logo, mascot, and how to socially integrate into the host city market. Consultants will then make recommendations for the NHL’s next expansion team in Seattle, Washington, so as to build sustained brand equity in the Seattle market.
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in fibrosis: To know your enemy, you must become your enemy
Authors: Bal Suzanne M. , Stadhouders Ralph
Published: September 2019

T helper 2–skewed regulatory T cells in the skin use GATA3 to suppress local profibrotic type 2 cytokine production. See the related Research Article by

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Novel Inducers of the Expression of Multidrug Efflux Pumps That TriggerPseudomonas aeruginosaTransient Antibiotic Resistance
Authors: Laborda Pablo , Alcalde-Rico Manuel , Blanco Paula , Martínez José Luis , Hernando-Amado Sara
Published: September 2019

The study of the acquisition of antibiotic resistance (AR) has mainly focused on inherited processes, namely, mutations and acquisition of AR genes. However, inducible, noninheritable AR has received less attention, and most information in this field derives from the study of antibiotics as inducers of their associated resistance mechanisms. Less is known about nonantibiotic compounds or situations that can induce AR during infection.
Conceptual Model of Biofilm Antibiotic Tolerance That Integrates Phenomena of Diffusion, Metabolism, Gene Expression, and Physiology
Authors: Stewart Philip S. , White Ben , Boegli Laura , Hamerly Timothy , Williamson Kerry S. , Franklin Michael J. , Bothner Brian , James Garth A. , Fisher Steve , Vital-Lopez Francisco G. , Wallqvist Anders
Published: September 2019

Bacteria in biofilms are protected from killing by antibiotics, and this reduced susceptibility contributes to the persistence of infections such as those in the cystic fibrosis lung and chronic wounds. A generalized conceptual model of biofilm antimicrobial tolerance with the following mechanistic steps is proposed: (i) establishment of concentration gradients in metabolic substrates and products; (ii) active biological responses to these changes in the local chemical microenvironment; (iii) entry of biofilm cells into a spectrum of states involving alternative metabolisms, stress responses, slow growth, cessation of growth, or dormancy (all prior to antibiotic treatment); (iv) adaptive responses to antibiotic exposure; and (v) reduced susceptibility of microbial cells to antimicrobial challenges in some of the physiological states accessed through these changes.
Cenozoic carbonate burial along continental margins
Authors: van der Ploeg Robin , Boudreau Bernard P. , Middelburg Jack J. , Sluijs Appy
Published: September 2019

Marine carbonate burial represents the largest long-term carbon sink at Earth’s surface, occurring in both deep-sea (pelagic) environments and shallower waters along continental margins. The distribution of carbonate accumulation has varied over geological history and impacts the carbon cycle and ocean chemistry, but it remains difficult to quantitatively constrain. Here, we reconstruct Cenozoic carbonate burial along continental margins using a mass balance for global carbonate alkalinity, which integrates independent estimates for continental weathering and pelagic carbonate burial. Our results indicate that major changes in marginal carbonate burial were associated with important climate and sea-level change events, including the Eocene-Oligocene transition (ca. 34 Ma), the Oligocene-Miocene boundary Mi-1 glaciation (ca. 23 Ma), and the middle Miocene climate transition (ca. 14 Ma). In addition, we find that a major increase in continental weathering from ca. 10 Ma to the present may have driven a concomitant increase in pelagic carbonate burial. Together, our results show that changes in global climate, sea level, and continental weathering have all impacted carbonate burial over the Cenozoic, but the relative importance of these processes may have varied through time.
The Aspen paleoriver: Linking Eocene magmatism to the world’s largest Na-carbonate evaporite (Wyoming, USA)
Authors: Hammond Alexander P. , Carroll Alan R. , Parrish Ethan C. , Smith M. Elliot , Lowenstein Tim K.
Published: September 2019

Deposition of trona, nahcolite, and other Na-carbonate evaporite minerals in lakes is commonly closely associated with active volcanism, suggesting that the excess alkalinity required for their formation may arise from fluid-rock interactions involving hydrothermal waters that contain magmatic CO2. Paradoxically, the world’s largest Na-carbonate occurrence, contained within the Eocene Green River Formation in Wyoming, USA, was not associated with nearby active magmatism. Magmatism was active ∼200 km southeast in the Colorado Mineral Belt, however, suggesting that a river draining this area could have supplied excess alkalinity to Eocene lakes. Sedimentologic studies in southwestern Wyoming, along the course of the hypothesized Aspen paleoriver, document fluvial and deltaic sandstone with generally northwest-directed paleocurrent indicators. Sandstone framework grain compositions and detrital zircon ages are consistent with derivation from the Colorado Mineral Belt and its host rocks. These results provide the first confirmation of a fluvial connection to downstream Eocene lakes, and indicate that lake deposits may offer a unique perspective on upstream magmatic and hydrothermal histories.
How coping can hide larger systems problems: the routine immunisation supply chain in Bihar, India
Authors: Lee Bruce Y , Wedlock Patrick T , Mitgang Elizabeth A , Cox Sarah N , Haidari Leila A , Das Manoja K , Dutta Srihari , Kapuria Bhrigu , Brown Shawn T
Published: September 2019

Introduction

Coping occurs when health system personnel must make additional, often undocumented efforts to compensate for existing system and management deficiencies. While such efforts may be done with good intentions, few studies evaluate the broader impact of coping.

Methods

We developed a computational simulation model of Bihar, India’s routine immunisation supply chain where coping (ie, making additional vaccine shipments above stated policy) occurs. We simulated the impact of coping by allowing extra trips to occur as needed up to one time per day and then limiting coping to two times per week and three times per month before completely eliminating coping.

Results

Coping as needed resulted in 3754 extra vaccine shipments over stated policy resulting in 56% total vaccine availability and INR 2.52 logistics cost per dose administered. Limiting vaccine shipments to two times per week reduced shipments by 1224 trips, resulting in a 7% vaccine availability decrease to 49% and an 8% logistics cost per dose administered increase to INR 2.73. Limiting shipments to three times per month reduced vaccine shipments by 2635 trips, which decreased vaccine availability by 19% to 37% and increased logistics costs per dose administered by 34% to INR 3.38. Completely eliminating coping further reduced shipments by 1119 trips, decreasing total vaccine availability an additional 24% to 13% and increasing logistics cost per dose administered by 169% to INR 9.08.

Conclusion

Our results show how coping can hide major system design deficiencies and how restricting coping can improve problem diagnosis and potentially lead to enhanced system design.
Incubator traffic light: the development of an alcohol-based hand rub dispenser system for neonatal incubators with visual feedback to improve hand hygiene compliance
Authors: van Gils Ronald H J , Helder Onno K , Wauben Linda S G L
Published: September 2019

Introduction

Sustained high compliance with hand hygiene prior to patient contact in a neonatal intensive care unit (NICU) could reduce the spread of pathogens and incidence of bloodstream infections of preterm infants. These infections are associated with high mortality, morbidity and additional costs. Behaviour change interventions to promote hand hygiene, such as education, have only temporary beneficial effect on compliance. Our aim is to develop a technical intervention that supports a sustainable behaviour change for appropriate hand hygiene among NICU healthcare professionals.

Methods

Students from different disciplines incrementally designed and evaluated solutions in co-creation with healthcare professionals of a NICU in a teaching hospital.

Results

A prototype of the ‘Incubator Traffic Light’ system for neonatal incubators was developed, that is, a touchless alcohol-based hand rub (ABHR) dispenser with integrated colour display and incubator door sensor with lights. The system provides visual feedback to support healthcare professionals’ compliance with the prescribed 30 s drying time for ABHR. After 30 s, green lights indicate that the incubator doors may be opened. In the event that doors are opened without dispensing ABHR or earlier than 30 s, blinking orange lights and a display message urge the person to close the doors. The system documents compliance data in a web-based database.

Conclusions

We developed a sophisticated technical intervention to support hand hygiene compliance. It is ready for clinical tests that should prove that the system contributes to sustainable hand hygiene compliance near neonatal incubators.
Transdermal fentanyl to parenteral morphine route switch and drug rotation in refractory cancer cachexia
Authors: Alsirafy Samy A , Alabdullateef Saad H , Elyamany Ashraf M , Hassan Amneh D , Almashiakhi Mohammed
Published: September 2019

It is recommended not to use transdermal fentanyl (Fe) patches (TFP) in cancer cachexia but TFP may be the only available option for pain. Limited evidence suggests lower Fe absorption from TFP in cachexia. We describe a case of metastatic breast cancer with refractory cachexia. Her pain was uncontrolled on TFP and was route switched and drug rotated to intravenous morphine (M). We were conservative and did not use the 1:100 TFP to oral M conversion ratio. Assuming opioid needs were similar before and after switch/rotation, the suitable conversion ratio in this case was about 1:25. Absent clear guidelines on converting from TFP in cachexia, it is better to avoid TFP. When essential to use TFP in cachexia, caution should be taken when switching from TFP to avoid overdose.
Mental health service users’ progression from illicit drug use to schizophrenia in New Zealand
Authors: Mellsop Graham , Tapsell Rees , Holmes Pragya
Published: September 2019

Background

Recently, publications have hypothesised that the demonstrated increase in the incidence of schizophrenia in New Zealand is a side effect of the increased strength of available cannabis derivatives over the last 25+ years and the much more recent increase in the population’s use of methamphetamine.

Aim

To compare the rates of later schizophrenia between age-matched mental health service users with initial diagnoses as alcohol abusers or illicit drug users.

Method

From the PRIMHD comprehensive national database, all users of the mental health services over a 5-year period who received an ICD-10 presenting diagnosis of alcohol or substance use/abuse were identified. For each person identified, the database was examined for the following 3 years to determine the numbers later diagnosed with schizophrenia.

Results

For the initial alcohol problem people in their twenties, 1.7% were diagnosed as suffering from schizophrenia in the subsequent 3 years. For the initial drug problem people, the rate was 10.9%. Within that drug-using population, the indigenous Maori developed schizophrenia at a higher rate than did the remainder of the population.

Conclusion

These findings in New Zealand require further research into their generalisability, context and explanation.
Growth differentiation factor-15 as candidate predictor for mortality in adults with pulmonary hypertension
Authors: Geenen Laurie W , Baggen Vivan J M , Kauling Robert M , Koudstaal Thomas , Boomars Karin A , Boersma Eric , Roos-Hesselink Jolien W , van den Bosch Annemien E
Published: September 2019

Objective

Despite its predictive value for mortality in various diseases, the relevance of growth differentiation factor-15 (GDF-15) as prognostic biomarker in pulmonary hypertension (PH) remains unclear. This study investigated the association between GDF-15 and outcomes in adults with PH.

Methods

This is a single-centre prospective observational cohort study. All adults with PH were included at the day of their diagnostic right heart catheterisation between 2012 and 2016. PH due to left heart disease was excluded. Venous blood sampling was performed and included GDF-15 and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements. Kaplan-Meier curves and Cox regression analysis were used to investigate the association between GDF-15 and a composite endpoint of death or lung transplantation. We adjusted for age and NT-proBNP in multivariable analysis. Reference values were established by GDF-15 measurements in healthy controls.

Results

GDF-15 was measured in 103 patients (median age 59.2 years, 65% women, 51% pulmonary arterial hypertension). GDF-15 was elevated in 76 patients (74%). After a median follow-up of 3.4 (IQR 2.3–4.6) years, 32 patients (31.1%) reached the primary endpoint. Event-free survival 2 years after diagnosis was 100% in patients with normal GDF-15 versus 72.4% in patients with elevated GDF-15 (p=0.007). A significant association was found between GDF-15 and the primary endpoint (HR per twofold higher value 1.77, 95% CI 1.39 to 2.27, p<0.001), also after adjustment for age and NT-proBNP (HR 1.41, 95% CI 1.02 to 1.94, p=0.038).

Conclusions

High GDF-15 levels are associated with an increased risk of death or transplant in adults with PH, independent of age and NT-proBNP. As non-specific biomarker, GDF-15 could particularly be useful to detect low-risk patients.
Differences in public support for handgun purchaser licensing
Authors: Crifasi Cassandra K , Stone Elizabeth M , McGinty Beth , Vernick Jon S , Barry Colleen L , Webster Daniel W
Published: September 2019

Objective

To assess whether there are differences in support for handgun purchaser licensing.

Methods

We used data from four waves of online, national polling on gun policy. To estimate differences in support for licensing across groups, we categorised respondents by whether they personally owned a gun, lived in a state with handgun purchaser licensing or lived in a state regulating private sales without a licensing system.

Results

Eighty-four per cent of adults living in states with licensing supported the policy compared with 74% in states without the law (p<0.001). Seventy-seven per cent of gun owners living in states with licensing supported the policy vs 59% of gun owners in states without licensing (p<0.001).

Conclusions

Support for licensing among gun owners living in states with these laws, many of whom have presumably gone through the process, was much higher than gun owners in states without such laws.
Waterpipe tobacco smoke toxicity: the impact of waterpipe size
Authors: Hauser Cindy DeForest , Mailig Ronnae , Stadtler Hannah , Reed Jenna , Chen Shi , Uffman Emilie , Bernd Karen
Published: September 2019

Introduction

Waterpipe tobacco smoking continues to show increasing popularity, especially among individuals between 18 and 22 years old. Waterpipe tobacco smoke (WTS) is a mixture of particulates and gases formed from the combustion of the charcoal and volatilisation and humidification of the tobacco+humectant+flavouring substrate known as shisha or mu’assel. As such, variation in the configuration of the waterpipe may affect the particles produced. Our study focuses on the effects of waterpipe size on the physical properties and cytotoxicity of the smoke produced.

Methods

Shisha type and headspace volume were held constant and a modified Beirut puff protocol was followed while the size of the waterpipe was varied. Particle concentrations and size distributions were measured using a TSI Engine Exhaust Particle Sizer. Type II alveolar cells were exposed to smoke at the air-liquid interface and two metrics of cell health analysed.

Results

In a 30 min session, we observed a decrease in total particle concentration (1014–1013) and mass (10 000–2800 mg/m3) and an increase in particle size (125–170 nm) as pipe height increases from 22 to 55 cm and bowl size from 300 to 1250 mL. Smoke from all pipe sizes caused decreases in lysosomal function (>40%) and membrane integrity (>60%) 24 hours post 57 min exposure, and meet the National Institutes of Health definition of a cytotoxic agent (≥30% decrease in cell viability).

Conclusion

Smoke from waterpipes of all sizes causes significant alveolar cellular harm, indicating that this device needs regulation as a hazard to human health.