bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the Influence of Operating Point on the Shape and Position of Textile Material in the Inlet Pipe to a Dry-Installed Wastewater Pump
Authors: Jensen Anna Lyhne , Gerlach Stefan , Lykholt-Ustrup Flemming , Sørensen Henrik , Rosendahl Lasse , Thamsen Paul Uwe
Published: October 2017

Wet wipes and similar flexible objects are causing major problems in wastewater systems as these materials often lead to clogging in the wastewater pumps. However, the understanding of clogging phenomena and the behaviour of these objects in the wastewater system is limited. Using a scaled pumping station with major parts constructed in acrylic glass, enabling good visual access, six parameters of shape, position and orientation of dustcloths in the pumping system are investigated at nine different operating points. In each test, 20 dustcloths are added to the pump sump and a fast digital camera captures the dust-cloths inside the inlet pipe close to the pump with a frame rate of 150 fps. Limited differences in the results of the chosen textile parameters indicate that the phenomena leading to different types of clogging occurs inside the pump and not in the inlet pipe. The determined parameters of shape, position and orientation can be used as initial conditions in simulation of clogging phenomena.
Marker Re-Distancing (MRD) Algorithm for High-Fidelity Interface Tracking on Arbitrary Meshes
Authors: Greene Patrick T. , Nourgaliev Robert , Schofield Samuel P.
Published: October 2017

A new sharp high-order interface tracking method for multi-material flow problems on unstructured meshes is presented. This marker re-distancing (MRD) method is designed to work accurately and robustly on unstructured, generally highly distorted meshes, necessitated by applications within ALE-based hydrocodes. The method is a hybrid of a Lagrangian marker tracking method and a novel discontinuous Galerkin (DG) projection based level set re-distancing algorithm. The re-distancing method is formulated as a constrained minimization problem and is shown to obtain arbitrary orders of convergence for smooth interfaces. High-order (>2nd) re-distancing on irregular meshes is a must for applications were the interfacial curvature is important for the underlying physics, such as surface tension, wetting, and detonation shock dynamics. Since no PDE is solved for re-distancing, the method does not have a stability time step restriction, which is particularly useful in combination with AMR, used here to efficiently resolve fine interface features. In addition, the method can robustly handle discontinuities in the distance function without explicit utilization of solution limiters. Results will be shown for a number of different interface geometries, which will demonstrate the method’s capability of obtaining high-fidelity results on arbitrary meshes.
LES of Flow Past a Circular Cylinder With Roughened Surface
Authors: Jiang Li , Shan Hua , Mansfield John , Junghans Kurt , Harrison Emily
Published: October 2017

The present work concerns large eddy simulation (LES) of flow past smooth and roughened circular cylinder at Reynolds numbers in the subcritical, critical, and supercritical regimes. The cylinder surface is either entirely or partially roughened by irregular distributed roughness. The statistics obtained from the actual roughness samples are used to numerically generate the roughness height distribution on the cylinder surface. Part of the roughness height variations on the surface can be resolved by the LES grid, the contribution from the unresolved part of the surface roughness is modeled by a dynamic sub-grid-scale (SGS) surface roughness model developed by Anderson & Meneveau. Similar to the dynamic Smagorinsky SGS model, the model parameter is determined dynamically using a consistency condition for the total force calculated at both the grid- and test-filter widths. The LES results are compared with measured data.
Prediction of Local Losses of Low Re Flows in Elastic Porous Media
Authors: Becker Sid M. , Gasow Stefan
Published: October 2017

An isotropic elastic porous structure whose pore geometry is regular (periodically uniform) will experience non-uniform deformation when a viscous fluid flows through the matrix under the influence of an externally applied pressure difference. In such a case, the flow field will experience a non-uniform pressure gradient whose magnitude increases in the direction of bulk flow. In this study, a method is presented that predicts local losses of the flow through a porous matrix whose geometry varies in the direction of flow. Employing an asymptotic expansion about the variation in geometry provides an expression relating local hydraulic permeability to local pore geometry. In this way the pressure field is able to be determined without requiring the explicit solution of the flow field. In this study a test case is presented showing that the local pressure losses are predicted to be within 0.5% of the losses determined from the solution to the Navier-Stokes Equations. The approach can be used to simplify the coupled fluid-solid problem of flow through elastic porous media by replacing the need to explicitly solve the flow field.
Sequential Design of UAV Fuselage Pods Using Bounding Aerodynamic Models
Authors: Valenti Justin D. , Kinzel Michael P. , Miller Simon W.
Published: October 2017

In this work, a Sequential Decision Process (SDP) is applied to perform fuselage design using Computational Fluid Dynamics (CFD). The SDP uses models to provide two-sided estimates that attempt to bound the exact solution, ultimately converging to an optimal design space to be analyzed with models of increased fidelity. The present work proposes the use of laminar and turbulent physics in CFD models to form lower and upper bounds on drag calculations, respectively. These bounding models are then used in a formal SDP to cull the design space, focusing the region of interest for increased fidelity modeling and analysis. Increasing mesh resolution is used to increase fidelity, creating a multi-fidelity approach to aerodynamic shape design. In this work the SDP-CFD design approach is applied to two design problems: (1) drag minimization of a fairing with a defined thickness and (2) drag per unit volume minimization of a fairing. The results of this study demonstrate that the SDP-CFD approach can accurately and quickly improve the fuselage design.
Effect of Near Wall Modeling Approaches on Solid Particle Erosion Prediction
Authors: Zhang Jun , McLaury Brenton S. , Shirazi Siamack A.
Published: October 2017

Computational Fluid Dynamics (CFD) based erosion prediction procedures are carried out to predict erosion for a submerged liquid jet impingement geometry. 2-D axisymmetric modeling with different near wall treatments are employed to model the wall bounded turbulent jet flow. Discrete Phase Model (DPM) is applied to track particles and obtain particle impact characteristics. Erosion is calculated using a typical Finnie-Bitter model [1]. In this paper, two categories of near wall modeling approaches (wall functions and near wall models) are presented and examined. Erosion prediction results for 300 μm large particles and 25 μm small particles are compared with experimental data to evaluate different near wall models with application to erosion prediction. Near wall trajectories are extracted to explain prediction results and reveal particle near wall behaviors. It is shown that appropriate selection of meshes and near wall models is capable of yielding good erosion prediction regardless of particle size.
Experimental Investigation on Diffuser Rotating Stall in a Three-Stage Centrifugal Pump
Authors: Takamine Taiki , Watanabe Satoshi , Furukawa Daichi , Watanabe Hiroyoshi , Miyagawa Kazuyoshi
Published: October 2017

Rotating stall phenomenon frequently causes the troubles such as vibrations acting on the shaft system and reduces the reliability of turbomachines. In the present study, the diffuser rotating stall in a three-stage centrifugal pump was experimentally studied. Special emphasises were placed on the geometrical conditions; an axial offset of rotor against the stationary part, which might be unavoidable due to accumulation of geometrical tolerances and assembling errors., and the radial clearances of annular leakage paths which increases the thru-flow rate at the impellers and the first and second stage diffusers. As a result, with the rotor axial offset to the suction side, the rotating stall appeared only at the third stage diffuser, while with that to the discharge side, the rotating stall was more significant. By enlarging the leakage flow passages at the inter-stage bush and the balancing flow channel, the onset range of rotating stall became narrower in the first and second stage diffusers, which was well explained by the increase of the thru-flow rate. On the other hand, with the enlarged leakage passage at the liner ring, the onset range became slightly wider.
Pool Scrubbing Efficiency of Hypothesized Filtered Containment Venting System for APR1400 Nuclear Power Plants
Authors: Seo Seungwon , Lee Jungjae , Cho Yongjin
Published: October 2017

For a severe accident (a core melting accident) of nuclear power plants, a heat-up of the molten core might cause a overpressurizing of containment building to be damaged, if there couldn’t be given a proper cooling and/or a depressurizing strategy. In order to depressurize containment building and also to minimize the release of radioactive materials, filtered containment venting system (FCVS) might be used for a one of possible options. For a wet-type FCVS, radioactive aerosol released from molten core could be decontaminated by water pool, which is called pool scrubbing effect. The objective of this study is to find out regulatory insights for evaluating a wet-type FCVS for Korean nuclear power plant, APR1400. MELCOR, which is a severe accident analysis code developed by Sandia National Laboratories, was used for simulating postulated accidents. A full-plant scale calculation was performed considering the accident conditions such as temperature, pressure flow rate from containment to the pool of FCVS, behavior of radioactive materials and decontamination factors (DFs) for them. FCVS was operated with containment pressure set points. The decrease thermal margin between containment atmosphere and the pool of the FCVS influenced the DF, because the decreased amount of the steam due to the lowered thermal margin interrupted the radioactive aerosols and steam condensed.
Studies of Flow Induced on a Water Surface due to the Impingement of a Drop or a Water Source
Authors: Musunuri Naga , Benouaguef Islam , Amah Edison , Blackmore Denis , Fischer Ian S. , Singh Pushpendra
Published: October 2017

The particle image velocimetry (PIV) technique is used to study the flow induced on the surface of a salt waterbody when a drop impinges on the surface or when a source is present on the surface. The measurements show that the impingement of a fresh water drop causes a strong axisymmetric solutocapillary flow about the vertical line passing through the center of impact. The fluid directly below the center of impact rises upward, and near the surface, it moves away from the center of impact. The flow, which develops within a fraction of second after the impact, persists for several seconds. Similarly, when a fresh water source is present on a salt waterbody there is a solutocapillary flow which on the surface is away from the source and below the surface is towards the source. The solutocapillary flow is quasi-steady when the volume flow rate from the source is small in the sense that the salt concentration in the waterbody changes slowly.
Experimental Investigation of a Drafting Cyclist in Cross-Wind
Authors: Nedyalkov Ivaylo , Lovell Adam , Cunningham Alec
Published: October 2017

Drafting is commonly utilized in cycling, particularly during competitions. According to the literature, in a racing environment, the riders can expend 90% of their energy on overcoming drag, and can save about 30% of their energy by riding behind another rider in the absence of cross-wind. In the presence of a strong cross-wind, competitive cyclists form echelons by placing themselves about halfway behind each other, while being slightly offset sideways. Although forming an echelon is a common practice, the formation has not been sufficiently studied in the literature. To address this, the drag and side forces on a model cyclist were studied experimentally. A simplified 3D model was built based on the outline of a competitive cyclist. Two 1:11 scale models were rapid-prototyped and tested in a wind tunnel. The drafting effects on a cyclist were investigated for different yaw angles — the angles of the apparent wind with respect to the direction of cyclist motion. The effects of wind-stream-wise position and wind-off-stream-wise position were studied for each angle by measuring the drag and side-force on a model placed in the wake of another identical model. The results suggest that there is a significant decrease in both drag and side force when a cyclist is riding in the wake of another cyclist. Although a smaller wind-stream-wise offset generally results in smaller forces, this effect is not significant for most configurations. The offset in the wind-off-stream-wise direction has a noticeable effect on the forces — no off-stream-wise offset results in the lowest drag and side force, except for low yaw angles at which it may be beneficial for the drafting cyclist to be slightly forward with respect to the in-line (no offset) position.
A Hydrofoil Configuration for Wind Powered Energy Ship Applications
Authors: Woeste Jacob T. , Turner Mark G. , Saxer Nicolas
Published: October 2017

Hydrofoils allow for boats to reach greater speeds by lifting the hulls of the boat out of the water. This reduces the drag due to the hulls pushing through the water. Implementing this technology on energy ships, sailboats or kiteboats that generate renewable energy using wind power, can increase the efficiency of such energy generating systems.

A hydrofoil design was developed and manufactured for a Hobie 17 sailboat to allow for preliminary testing of the energy ship concept. A V-shape hydrofoil design was used to provide hands-free foiling of the sailboat. The advantages and disadvantages of this configuration are explored. An attachment mechanism is also described that allows for the user to preset the angle of attack of the dihedral hydrofoils, and an analysis of the adjustment angle’s impact on the hydrofoils′ angle of attack is quantified. Since the V-shape hydrofoil design pierces the water’s surface, ventilation becomes an issue due to air being sucked down the low-pressure lifting surface of the hydrofoils. To reduce ventilation, fences were added along the top surface of the hydrofoils. The hydrofoil design was tested and proven to be a feasible configuration for wind powered boats.
Comparative Calculations of TROI TS-2 and TS-3 Steam Explosion Experiments With TEXAS-V
Authors: Kim Taehoon , Pak Sukyoung , Cho Yongjin
Published: October 2017

During a severe accident, contact of the molten corium with the coolant water may cause an energetic steam explosion which is a rapid increase of explosive vaporization by transfer to the water of a significant part of the energy in the corium melt. This steam explosion has been considered as an adverse effect when the water is used to cool the molten corium and could threaten reactor vessel, reactor cavity, containment integrity. In this study, TROI TS-2 and TS-3 experiments as part of the OECD/SERENA-2 project were analyzed with TEXAS-V. Input parameters were based on actual TROI experiment data. In mixing simulations, calculated results were compared to melt front behavior, void fraction in trigger time and other parameters in experiment results. In explosion simulations, corresponding to TROI experiments an external triggering was employed at the moment that melt front reached heights of 0.4 m. Calculated results of peak pressure and impulse at the bottom were compared with TROI experiment results. Melt front behaviors of the melt was different from the experimental results in both TS-2 and TS-3. Void fraction in triggering time in TS-2 was in good agreement with the experiment results and in TS-3 was slightly overestimated. The peak pressure and impulse at bottom were successfully predicted by TEXAS-V. These calculations will allow establishing whether the limitations and differences observed in the simulations of the experiments are important for the reactor case.
Experimental and Numerical Study on Solid Particle Erosion in Elbows Mounted in Series
Authors: Asgharpour Alireza , Zahedi Peyman , Arabnejad Khanouki Hadi , Shirazi Siamack A. , McLaury Brenton S.
Published: October 2017

Solid particle erosion in elbows is of great importance in the pipeline design process. In many situations, elbows are mounted in series with small distances between each other. Due to changes in flow direction and particles concentration after the first elbow, a significant change in erosion magnitude and pattern in the downstream elbows (second elbow) might be expected. The aim of this study is to investigate the solid particle erosion behavior in the second elbow. In the experimental study using a state-of-art ultrasonic technique, erosion magnitudes in two standard 4-inch elbows separated by a distance of 10 pipe diameter have been measured. Experiments have been conducted in single and two-phase flow regimes for different particle sizes and gas and liquid velocities. In most of the cases, the maximum erosion in the second elbow was less than the first elbow, and the erosion pattern in the second elbow was slightly different than the first elbow. Comparison of single and two-phase flow results for both elbows revealed that in two-phase flow regime a major reduction in erosion magnitude happens as a results of the presence of liquid in the pipe. Additionally, for further considerations, the experimental conditions have been simulated numerically using ANSYS FLUENT software. Simulations have been performed for different mesh grids and turbulence models to examine how they influence the erosion in the second elbow as both can affect the particles trajectories. The accuracy of the numerical results are evaluated with available experimental data. For most of the cases, the erosion predictions are in a good agreement with experimental results. For both elbows by increasing the gas velocity and particle size, the maximum erosion increased.
Improvement of Cavitation Surge in a Double Suction Centrifugal Pump by Use of CFD
Authors: Kagawa Shusaku , Matsushita Naoki
Published: October 2017

This paper discussed about suppressions of cavitation surge in a double suction centrifugal pump. In order to suppress the cavitation surge, CFD simulation was carried out. Cavitation surge was observed near the best efficiency point, and it was difficulty to operate the pump stably. The specific speed of the tested pump was about 81 [m3/min, min−1, m] or 533 [ft., USGPM, min.−1]. In general, the main cause of the cavitation surge is inlet reverse flows at the impeller inlet. In order to prevent the inlet reverse flow, two kinds of modification at the impeller inlet were applied. One was the reduction of impeller inlet area by using a suction ring, and the other was the reduction of impeller inlet diameter. To reduce the computational time, in CFD model, a half of the double suction centrifugal pump was modeled. CFD simulations were carried out using ANSYS CFX with the Rayleigh Preset cavitation model. It was confirmed that the head fluctuation caused by the cavitation phenomena was predicted qualitatively by use of unsteady CFD simulation in the original pump impeller. The head fluctuation was about the 16% of the time averaged head and the very low frequency was confirmed by the FFT analysis. In addition, the relationship between head characteristics and cavitation behavior was observed clearly. The objective of the suction ring was to eliminate the head fluctuations caused by the cavitation. It was concluded that the suction ring was very effective to prevent the cavitation surge. On the other hand, the decrease of impeller inlet diameter was effective to reduce the head fluctuations, which became half of that for the original pump impeller. As a result, it was suggested that the complete suppression of the cavitation surge by the reduction of impeller inlet diameter was difficult in this case. It was concluded that unsteady CFD simulations with cavitation model is very effective for clarification of the impeller inlet modification on the cavitation surge.
Computational Assessment of Double-Inlet Collector in Solar Chimney Power Plant Systems
Authors: Fathi Nima , Aleyasin Seyed Sobhan , Wayne Patrick , Vorobieff Peter
Published: October 2017

Solar chimney power plant systems (SCPPS) offer a simple and reliable way to generate electricity using solar radiation to drive a flow of buoyant air. A typical SCPP setup includes a collector, a tower, and a turbine or several turbines. Current SCPP designs have low thermal efficiency: only between 0.5% and 5% of the incident solar energy is converted into electricity. Inefficiencies result partially from limited mass flow rates through the tower. It is therefore desirable to provide a new design for the collector to increase the inlet air mass flow rate. In this paper, we present a double-inlet collector concept and results of numerical analysis to evaluate this design in terms of flow rate improvement. Computational fluid dynamics (CFD) was utilized to perform the numerical modeling and simulation (M&S) by using a finite volume method package. The Manzanares prototype (the only operational solar tower power plant with available published reports) is selected to implement the double-inlet collector design and study its effect on the power plant. Beside this case, we fabricated a 1/1000 scale model of the Manzanares prototype which enables us to measure the filed variables experimentally. Validation analysis was performed to quantify the reliability of our numerical model with respect to the available experimental data. We obtained a significant increase (14%) in the available output power by using the double-inlet collector.
Design and Performance of a Hypersonic Wind Tunnel
Authors: Maxwell Jesse
Published: October 2017

A moveable block planar nozzle wind tunnel design from the University of Michigan in 1955 was shown with previous analysis to operate between Mach 1 and at least Mach 6.3 for mid-size test sections, with continuous variation in Mach number and accounting for limitations governed by supply temperature and pressure, liquefaction, flow rate, and flow quality for a desired dynamic pressure or Reynolds number. The moveable block planar nozzle design allows for continuous variation of Mach number, based on a Method of Characteristics solution to a convergent-divergent nozzle with a boundary layer correction. The present work summarizes the design considerations and hardware performance requirements for such a tunnel in the blowdown configuration, with a comparison between cold and hot operation for various test section sizes and supply conditions. The flow quality is compared between a two planar nozzles and an axisymmetric nozzle for a 12×12[in] test section, the effect of physical scaling on flow quality and boundary layer encroachment is investigated across scales of 1×1” to 12×12” test sections at Mach 5, and the merits of planar nozzle aspect ratios greater than unity are presented and discussed.
Investigation of EGR With EGB (Exhaust Gas Bypass) on Low Speed Marine Diesel Engine Performance and Emission Characteristics
Authors: Wang Zhanguang , Zhou Song , Feng Yongming , Zhu Yuanqing
Published: October 2017

In 2016, the International Maritime Organization (IMO) has enforced stricter nitrogen oxide (NOx) emission standards. Exhaust gas recirculation (EGR) technology is an effective way to achieve IMO Tier III standards for two-stroke marine diesel engines. This paper selected the 6S50ME-C8.2 diesel engine for research, by making use of GT-POWER simulation software. In this paper, three different types of EGR systems were built to investigate the effects of EGR on engine performance and NOx emissions.

The results show that both the high pressure EGR system and the low pressure EGR system can reduce NOx emissions with the power drop and BSFC risen.

While in the high pressure EGR system combined with CB (cylinder bypass) and EGB (exhaust gas bypass), more NOx emissions can be reduced with less power drop and BSFC risen. What is more, the running points of the compressor are still in the efficient areas and away the surge margin.

Based on the conclusions, the results obtained in this paper can provide reference for turbocharged diesel engines with EGR systems to reduce NOx emissions and improve engine performance.
Oblique Shock Reflection Over a Soft Reflecting Surface
Authors: Henmi Hiroki , Kobayashi Susumu
Published: October 2017

In this study, we conducted experiments using a shock tube to investigate how the thickness of soft reflecting material affects the reflected shock wave of oblique shock reflection. Results indicated that transition to Mach reflection (MR) is delayed when the reflecting surface is silicone, compared with that when the surface is rigid. Regarding the influence of reflecting material thickness, no remarkable difference was observed between 1mm and 10mm thickness, due to the trade-off of reflecting wedge angle and material thickness. No significant difference was observed regarding the influence of silicone on wave configuration.
Effect of Silt and Jet Diameter on Performance of Turgo Impulse Hydro Turbine
Authors: Khurana Sourabh , Goel Varun , Singh Gurmeet
Published: October 2017

Silt particles flow through hydro turbines cause erosion in turbines and due to silt efficiency of turbine reduces, vibrations produces in hydro turbines components and finally breakdown of hydro turbines take place, which causes immense losses. In the present study experiments were carried out to study the effect of silt size, silt concentration, jet velocity and operating hours on performance of Turgo impulse turbine. Silt was collected from Dehar power house (India). It has been found that erosion strongly depends on silt parameters (silt size, silt concentration) and operating parameters (Jet velocity and operating hours of turbine). A correlation has been developed as a function of jet diameter, silt parameters and operating parameters of percentage efficiency loss in Turgo impulse turbine.
Investigation of Cavitation Phenomena on Noise of Underwater Propeller
Authors: Karimi Noughabi Amir , Bayati Morteza , Tadjfar Mehran
Published: October 2017

Underwater propeller cavitation noise is composed of tonal blade rate noise and high frequency broadband noise. Cavitation usually increases overall sound pressure level in the various frequency ranges which depends on the type of cavitation. This research had been carry out to predict the radiated noise from a marine propeller in presence of cavitation with various cavitation types. The analysis is performed by coupling an acoustic code based on the Ffowcs Williams-Hawkings (FWH) equation to unsteady Reynolds-averaged Navier-Stokes (URANS) which able to simulate multiphase flows in rotational domains. A brief summary of numerical method used to model the cavitation around the underwater propeller are presented and the thrust and torque coefficients are validated in different flow conditions by experimental results. The radiated noise along the shaft direction and perpendicular to the shaft direction is studied on both cavitating and non-cavitating propellers. Then, to predict the radiated noise due to cavitation in marine propeller, the computed sound pressure level (SPL) for non-cavitating marine propeller is compared with the SPL for the same propeller in cavitation conditions at various cavitation number and advanced coefficients. The noise analysis helps to determine the dominant noise source of the underwater propeller in different conditions, which will provide a basis for proper noise control strategies.
A new species and new host record of Demodecidae (Acariformes: Prostigmata) associated with the bandicoot rat (Rodentia: Muridae) from Lao PDR with data on parasitism and a checklist of the demodecid mites of rodents
Authors: Izdebska Joanna N. , Rolbiecki Leszek , Morand Serge , Ribas Alexis
Published: October 2017

A new species, Demodex bandicotae sp. nov. (Acariformes: Demodecidae), is described based on adult stages from the hairy skin of the greater bandicoot rat Bandicota indica (Bechstein, 1800), collected in Lao People’s Democratic Republic (Laos). Parasites were noted in 41.7% of bandicoot rats, with a mean intensity of 5.6 parasites in the tested skin fragments of the host. This is the first report on Demodecidae mites in rodents of the genus Bandicota Gray, 1873. A checklist of demodecid mites in rodents worldwide is also provided.
Community Engagement Through Sport: University Partnerships to Promote Youth Development
Authors: Hemphill Michael A. , Martinek Tom
Published: October 2017

Many kinesiology departments engage in partnerships that aim to promote positive youth development through physical activity. These partnerships are often enhanced by mutually beneficial goals and shared decision making between university and community partners. This paper describes how sport has been at the center of two university-community partnerships that have helped to teach life skills to youth. We draw upon our experience working with community partners to illuminate challenges and opportunities for youth-focused partnerships. The programs include an emphasis on sustainability. As kinesiology programs continue to enhance their efforts to partner and support youth development, case studies such as this may help inform our efforts.
Sexual Harassment and Internships: How Do We Protect Our Students and Program?
Authors: Russ Anne C. , Moffit Dani M. , Mansell Jamie L.
Published: October 2017

Sexual harassment is a sensitive and pervasive topic in higher education. Programs and institutions have the responsibility to protect the students from sexual harassment under Title IX of the Education Amendments of 1972 (United States Department of Education Office of Civil Rights, 2011). While much attention has been focused toward on-campus interactions (i.e., professor/student, student/student), many students participate in off-campus fieldwork and internships associated with coursework, where the students are still protected under Title IX. The purpose of this discussion is to define sexual harassment, summarize research regarding sexual harassment in a fieldwork setting, consider how sexual harassment affects students, and identify resources to help programs identify and respond to sexual harassment.
“It Made Me Want to be that Spark”: A Case Study of the Experiences of College Student Group Exercise Instructors
Authors: Buzzelli Armand
Published: October 2017

While recent research has focused on leadership and development in collegiate club and intramural sports participants, many of the findings and suggestions may be deemed applicable to student roles within college fitness and group exercise programs. The purpose of this exploratory case study was to learn about the leadership experiences, motivations, benefits, and perceived limitations to group fitness instruction for students at a small, private, Mid-Atlantic university, and to discover potential influences of these experiences on the overall collegiate experience. The researcher was interested in insights of both current and recently graduated students who serve as group fitness instructors at their college. The researcher interviewed eight participants from one institution selected through convenience sampling. While this study used a small sample from one institution, interviewee responses were consistent, relevant, and may be expanded upon in future research. Participants reported that they improved leadership skills, public speaking, conflict resolution, and developed a campus identity as a result of teaching group exercise. The majority of the participants had not considered the benefits of their experiences in terms of professional development, and relationship building before their participation in the study. These findings demonstrate that campus recreation departments need to provide evidence to students and university administration that their programs not only provide enjoyment and health benefits for participants, but also a litany of “soft skills” and professional experiences that employers will look for after graduation.
Moderating Effects of Campus Recreation Participation in the Relationship between Grade Point Average and First-Year Student Engagement: An Exploratory Study
Authors: Mayers Rebecca Fallon , Wilson Austin W. , Potwarka Luke R.
Published: October 2017

Health and student success outcomes are often thought to be associated with campus recreation participation. Thus, decision makers at the university level are interested in the relationship between campus recreation participation, grade point average (GPA), and student engagement. Previous research has called for a clearer understanding of how campus recreation is meaningful for first-year university students and its potential influences on GPA. This study explored the influence of first-year students' campus recreation participation, GPA, and facets of student engagement. First-year university students ( N = 171) were surveyed. Demographic characteristics, GPA, and level of engagement on five scales were assessed. Results showed that GPA positively influenced those who participated in campus recreation on four facets of engagement. Results may help academic administrators to target efforts toward making the transition from high school to university easier. Promoting campus recreation participation may be effective for strengthening students' level of engagement and result in positive success outcomes.
What Gets Them Moving? College Students' Motivation for Exercise: An Exploratory Study
Authors: Snyder Kailey , Lee Jung Min , Bjornsen Abby , Dinkel Danae
Published: October 2017

This exploratory study applied constructs of self-determination theory to assess college students exercise motivation and to determine the influence on exercise within active college students. Students included 24 college students (12 normal weight, 12 overweight) currently meeting national exercise recommendations. Surveys and semistructured interviews were used to assess exercise motivation. Descriptive statistics and MANOVA were used to analyze survey results. Horizontalization was used to analyze interview responses. It was found that the majority of students were extrinsically motivated for exercise regardless of BMI or gender. Identified regulation was found to be the most common form of motivation. Extrinsic motivation may be a key determinant for increasing exercise and enhancing utilization of campus recreation facilities among undergraduate students. Future efforts should consider the inclusion of extrinsic motivation (e.g., to look good, improve health) in communication strategies and program development.
TCR-stimulated changes in cell surface CD46 expression generate type 1 regulatory T cells
Authors: Ni Choileain Siobhan , Hay Joanne , Thomas Joelle , Williams Anna , Vermeren Matthieu M. , Benezech Cecile , Gomez-Salazar Mario , Hugues Owen R. , Vermeren Sonja , Howie Sarah E. M. , Dransfield Ian , Astier Anne L.
Published: October 2017

Defects in the T cell receptor–stimulated processing of a cell surface receptor may contribute to the pathogenesis of autoimmune diseases.
Papers of note in
Science Translational Medicine
9
(412)
Authors: Ferrarelli Leslie K.
Published: October 2017

This week’s articles describe ways to potentially treat obesity-associated disorders and prevent sepsis.
Praziquantel Targets M1 Macrophages and Ameliorates Splenomegaly in Chronic Schistosomiasis
Authors: Kong Delong , Zhou Chunlei , Guo Hongfei , Wang Wei , Qiu Jingfan , Liu Xinjian , Liu Jinfeng , Wang Lijuan , Wang Yong
Published: October 2017

Splenomegaly is a common feature of many infectious diseases, including schistosomiasis japonica. However, the immunopathogenesis and the treatment of splenomegaly due to schistosomiasis have been largely neglected. Praziquantel (PZQ), a classical schistosomicide, has been demonstrated by us and others to have antifibrotic and anti-inflammatory activities against schistosomiasis. In this study, we investigated the effect of PZQ on alleviating the splenomegaly caused by
Schistosoma japonicum
infection in mice. The results showed that the number of macrophages, especially the number of M1 macrophages, was significantly increased in the enlarged spleens of infected mice (
P
< 0.001). After PZQ treatment for 4 weeks, the number of splenic macrophages, especially the number of M1 macrophages, was significantly reduced (
P
< 0.001) by the way of apoptosis, and another schistosomicide, mefloquine, had no effect either on the splenomegaly or on reducing the number of macrophages. Furthermore, by using the murine macrophage line RAW 264.7, we found that PZQ could inhibit the formation of the NLRP3 inflammasome and attenuate phagocytic activity in M1 macrophages. Thus, our studies suggest that PZQ plays a powerful role in ameliorating the splenomegaly caused by
S. japonicum
infection, which presents a new strategy for the therapy of splenomegaly resulting from other pathological conditions.
Functional Involvement of Leishmania donovani Tryparedoxin Peroxidases during Infection and Drug Treatment
Authors: Das Sanchita , Giri Sagnik , Sundar Shyam , Shaha Chandrima
Published: October 2017

The parasiteLeishmania donovanicauses visceral leishmaniasis, a potentially fatal disease. The parasites survive within mammalian macrophages and express a unique set of enzymes, the tryparedoxin peroxidases, for their defense against oxidative stress generated by the host. In this study, we demonstrate different roles of two distinct enzymes, the mitochondrial tryparedoxin peroxidase (mTXNPx) and the cytosolic tryparedoxin peroxidase (cTXNPx), in defending the parasites against mitochondrial and exogenous oxidative stress during infection and drug treatment. Our findings indicate a greater increase in cTXNPx expression in response to exogenous oxidative stress and a higher elevation of mTXNPx expression in response to mitochondrial or endogenous stress created by respiratory chain complex inhibitors. Overexpression of cTXNPx inLeishmaniashowed improved protection against exogenous stress and enhanced protection against mitochondrial stress in parasites overexpressing mTXNPx. Further, parasites overexpressing cTXNPx infected host cells with increased efficiency at early times of infection compared to control parasites or parasites overexpressing mTXNPx. The mTXNPx-overexpressing parasites maintained higher infection at later times. Higher mTXNPx expression occurred in wild-type parasites on exposure to miltefosine, while treatment with antimony elevated cTXNPx expression. Parasites resistant to miltefosine or antimony demonstrated increased expression of mTXNPx, as well as cTXNPx. In summary, this study provides evidence of distinct roles of the two enzymes defined by virtue of their localization during infection and drug treatment.
In Vitro
Evaluation of Povidone-Iodine and Chlorhexidine against Outbreak and Nonoutbreak Strains of Mycobacterium abscessus Using Standard Quantitative Suspension and Carrier Testing
Authors: Cheng Aristine , Sun Hsin-Yun , Tsai Yi-Tzu , Wu Un-In , Chuang Yu-Chung , Wang Jann-Tay , Sheng Wang-Huei , Hsueh Po-Ren , Chen Yee-Chun , Chang Shan-Chwen
Published: October 2017

Povidone-iodine (PI) and chlorhexidine (CHX) are widely used antiseptics active against conventional
Staphylococcus aureus
,
Enterobacteriaceae
,
Candida
species, and viruses, but their efficacy against
Mycobacterium abscessus
remains unproven. We determined the
in vitro
potency of alcoholic PI and CHX against
M. abscessus
subsp.
abscessus
(ATCC 19977),
M. abscessus
subsp.
bolletii
(BCRC 16915), and our outbreak strain of
M. abscessus
subsp.
massiliense
(TPE 101) in reference to
Staphylococcus aureus
(ATCC 29213) by standard quantitative suspension and carrier methods (EN 14563). By suspension, all mycobacterial strains compared to
S. aureus
were significantly more resistant to CHX, but not PI. By carrier, the mean logarithmic reductions (LR) achieved by PI under clean (dirty) conditions were 6.575 (2.482), 5.540 (2.298), 4.595 (1.967), and 1.173 (0.889), while those achieved by CHX under clean (dirty) conditions were 3.164 (5.445), 5.307 (2.564), 3.844 (2.232), and 0.863 (0.389) for
S. aureus
,
M. abscessus
subsp.
bolletii
,
M. abscessus
subsp.
abscessus
, and
M. abscessus
subsp.
massiliense
, respectively.
M. abscessus
subsp.
massiliense
(outbreak strain) was significantly more resistant than the other tested strains to PI and CHX. By both methods, the mean LR achieved by PI was higher than for CHX for all mycobacterial strains, but under dirty conditions, neither antiseptic was effectively mycobactericidal (LR < 5). These preliminary findings caution against the universal replacement of PI with CHX as the first-line skin antiseptic, since all
M. abscessus
isolates were resistant to CHX. More studies are needed to establish the best practice for skin antisepsis if mycobacterial infections are also to be prevented.
Molecular Mechanisms of Intrinsic Streptomycin Resistance in Mycobacterium abscessus
Authors: Dal Molin Michael , Gut Myriam , Rominski Anna , Haldimann Klara , Becker Katja , Sander Peter
Published: October 2017

Streptomycin, the first drug used for the treatment of tuberculosis, shows limited activity against the highly resistant pathogen
Mycobacterium abscessus
. We recently identified two aminoglycoside-acetylating genes [
aac(2′)
and
eis2
] which, however, do not affect susceptibility to streptomycin. This suggests the existence of a discrete mechanism of streptomycin resistance.
M. abscessus
BLASTP analysis identified MAB_2385 as a close homologue of the 3″-
O
-phosphotransferase [APH(3″)] from the opportunistic pathogen
Mycobacterium fortuitum
as a putative streptomycin resistance determinant. Heterologous expression of
MAB_2385
in
Mycobacterium smegmatis
increased the streptomycin MIC, while the gene deletion mutant
M. abscessus
ΔMAB_2385 showed increased streptomycin susceptibility. The MICs of other aminoglycosides were not altered in
M. abscessus
ΔMAB_2385. This demonstrates that
MAB_2385
encodes a specific and prime innate streptomycin resistance determinant in
M. abscessus
. We further explored the feasibility of applying
rpsL
-based streptomycin counterselection to generate gene deletion mutants in
M. abscessus
. Spontaneous streptomycin-resistant mutants of
M. abscessus
ΔMAB_2385 were selected, and we demonstrated that the wild-type
rpsL
is dominant over the mutated

rpsL
K43R

in merodiploid strains. In a proof of concept study, we exploited this phenotype for construction of a targeted deletion mutant, thereby establishing an
rpsL
-based counterselection method in
M. abscessus
.
Combinations of Respiratory Chain Inhibitors Have Enhanced Bactericidal Activity against Mycobacterium tuberculosis
Authors: Berube Bryan J. , Parish Tanya
Published: October 2017

As an obligate aerobe,
Mycobacterium tuberculosis
uses its electron transport chain (ETC) to produce energy via oxidative phosphorylation. This pathway has recently garnered a lot of attention and is a target for several new antimycobacterials. We tested the respiratory adaptation of
M. tuberculosis
to phenoxyalkylbenzimidazoles (PABs), compounds proposed to target QcrB, a component of the cytochrome
bc
1
complex. We show that
M. tuberculosis
is able to reroute its ETC to provide temporary resistance to PABs. However, combination treatment of PAB with agents targeting other components of the electron transport chain overcomes this respiratory flexibility. PAB in combination with clofazimine resulted in synergistic killing of
M. tuberculosis
under both replicating and nonreplicating conditions. PABs in combination with bedaquiline demonstrated antagonism at early time points, particularly under nonreplicating conditions. However, this antagonistic effect disappeared within 3 weeks, when PAB-BDQ combinations became highly bactericidal; in some cases, they were better than either drug alone. This study highlights the potential for combination treatment targeting the ETC and supports the development of PABs as part of a novel drug regimen against
M. tuberculosis
.
NLRP3 Is a Critical Regulator of Inflammation and Innate Immune Cell Response during Mycoplasma pneumoniae Infection
Authors: Segovia Jesus A. , Chang Te-Hung , Winter Vicki T. , Coalson Jacqueline J. , Cagle Marianna P. , Pandranki Lavanya , Bose Santanu , Baseman Joel B. , Kannan Thirumalai R.
Published: October 2017

Mycoplasma pneumoniae
is an atypical bacterial respiratory pathogen known to cause a range of airway inflammation and lung and extrapulmonary pathologies. We recently reported that an
M. pneumoniae
-derived ADP-ribosylating and vacuolating toxin called community-acquired respiratory distress syndrome (CARDS) toxin is capable of triggering NLRP3 (NLR-family, leucine-rich repeat protein 3) inflammasome activation and interleukin-1β (IL-1β) secretion in macrophages. However, it is unclear whether the NLRP3 inflammasome is important for the immune response during
M. pneumoniae
acute infection. In the current study, we utilized
in vitro
and
in vivo
models of
M. pneumoniae
infection to characterize the role of the NLRP3 inflammasome during acute infection.
M. pneumoniae-
infected macrophages deficient for inflammasome components NLRP3, ASC (apoptosis speck-like protein containing a caspase activation and recruitment domain), or caspase-1 failed to process and secrete IL-1β. The MyD88/NF-κB signaling pathway was found to be critical for proinflammatory gene expression in macrophages infected with
M. pneumoniae
. C57BL/6 mice deficient for NLRP3 expression were unable to produce IL-1β in the airways during acute infection, and lack of this inflammatory response led to deficient immune cell activation and delayed bacterial clearance. These findings are the first to report the importance of the NLRP3 inflammasome in regulating the inflammatory response and influencing the progression of
M. pneumoniae
during acute infection.
Heparinase Is Essential for Pseudomonas aeruginosa Virulence during Thermal Injury and Infection
Authors: Dzvova Nyaradzo , Colmer-Hamood Jane A. , Griswold John A. , Hamood Abdul N.
Published: October 2017

The opportunistic pathogen
Pseudomonas aeruginosa
is a major cause of sepsis in severely burned patients. If it is not eradicated from the wound, it translocates to the bloodstream, causing sepsis, multiorgan failure, and death. We recently described the
P. aeruginosa
heparinase-encoding gene,
hepP
, whose expression was significantly enhanced when
P. aeruginosa
strain UCBPP_PA14 (PA14) was grown in whole blood from severely burned patients. Further analysis demonstrated that
hepP
contributed to the
in vivo
virulence of PA14 in the
Caenorhabditis elegans
model. In this study, we utilized the murine model of thermal injury to examine the contribution of
hepP
to the pathogenesis of
P. aeruginosa
during burn wound infection. Mutation of
hepP
reduced the rate of mortality from 100% for mice infected with PA14 to 7% for mice infected with PA14::
hepP
. While comparable numbers of PA14 and PA14::
hepP
bacteria were recovered from infected skin, only PA14 was recovered from the livers and spleens of infected mice. Despite its inability to spread systemically, PA14::
hepP
formed perivascular cuffs around the blood vessels within the skin of the thermally injured/infected mice. Intraperitoneal inoculation of the thermally injured mice, bypassing the need for translocation, produced similar results. The rate of mortality for mice infected with PA14::
hepP
was 0%, whereas it was 66% for mice infected with PA14. As before, only PA14 was recovered from the livers and spleens of infected mice. These results suggest that
hepP
plays a crucial role in the pathogenesis of PA14 during burn wound infection, most likely by contributing to PA14 survival in the bloodstream of the thermally injured mouse during sepsis.