bluuebunny/crossref_metadata_2025 huggingface dataset:
A Computationally Efficient Multichannel Active Road Noise Control System
Authors: Duan Jie , Li Mingfeng , Lim Teik C. , Lee Ming-Ran , Cheng Ming-Te , Vanhaaften Wayne , Abe Takeshi
Published: August 2014

A multichannel active noise control (ANC) system has been developed for a vehicle application, which employs loudspeakers to reduce the low-frequency road noise. Six accelerometers were attached to the vehicle structure to provide the reference signal for the feedforward control strategy, and two loudspeakers and two microphones were applied to attenuate acoustic noise near the headrest of the driver's seat. To avoid large computational burden caused by the conventional time-domain filtered-x least mean square (FXLMS) algorithm, a time-frequency domain FXLMS (TF-FXLMS) algorithm is proposed. The proposed algorithm calculates the gradient estimate and filtered reference signal in the frequency domain to reduce the computational requirement, while also updates the control signals in the time domain to avoid delay. A comprehensive computational complexity analysis is conducted to demonstrate that the proposed algorithm requires significantly lower computational cost as compared to the conventional FXLMS algorithm.
Thermo-Electric Modeling of Nanotube-Based Environmental Sensors
Authors: Martin Michael James , Manohara Harish
Published: August 2014

Free-standing electrically conductive nanotube and nanobridge structures offer a simple, small-scale, low-power option for pressure and temperature sensing. To sense pressure, a constant voltage is applied across the bridge. At small scales, the heat transfer coefficient is pressure-dependent. The change in the heat transfer coefficients results in the circuit operating at higher temperatures, with different resistances, at low pressures. This in turn will lead to a change in the electrical resistivity of the system. If the system is held at constant voltage, this can be measured as a change in the current in such systems, representing a simple alternative to existing Pirani gauges. The current work simulates the Joule heating, conduction and convection heat transfer of a 5 μm long suspended single-wall carbon-nanotube, incorporating temperature-sensitive material properties. The simulation allows prediction of the thermo-electrical response of the systems. The results agree with the trends observed in existing devices. Additional results look at the effects of system length, temperature, and contact resistances between the substrate and the device.
A Thermodynamic and Cost Analysis of Solar Syngas From the Zn/ZnO Cycle
Authors: Nicodemus Julia Haltiwanger , McGuinness Morgan , Maharjan Rijan
Published: August 2014

We present a thermodynamic and cost analysis of synthesis gas (syngas) production by the Zn/ZnO solar thermochemical fuel production cycle. A mass, energy, and entropy balance over each step of the Zn/ZnO syngas production cycle is presented. The production of CO and H2 is considered simultaneously across the range of possible stoichiometric combinations, and the effects of irreversibilities due to both recombination in the quenching process following dissociation of ZnO and incomplete conversion in the fuel production step are explored. In the cost analysis, continuous functions for each cost component are presented, allowing estimated costs of syngas fuel produced at plants between 50 and 500 MWth. For a solar concentration ratio of 10,000, a dissociation temperature of 2300 K, and a CO fraction in the syngas of 1/3, the maximum cycle efficiency is 39% for an ideal case in which there is no recombination in the quencher, complete conversion in the oxidizer, and maximum heat recovery. In a 100 MWth plant, the cost to produce syngas would be $0.025/MJ for this ideal case. The effect of heat recuperation, recombination in the quencher, and incomplete conversion on efficiency and cost are explored. The effects of plant size and feedstock costs on the cost of solar syngas are also explored. The results underscore the importance improving quencher and oxidizer processes to reduce costs. However, even assuming the ideal case, the predicted cost of solar syngas is 5.5 times more expensive than natural gas on an energy basis. The process will therefore require incentive policies that support early implementation in order to become economically competitive.
Experimental and Theoretical Investigations of Mechanical Joints With Form Defects
Authors: Lê Hoài-Nam , Ledoux Yann , Ballu Alex
Published: August 2014

This article deals with the behavior of a planar joint taking surface defects into account. Two theoretical concepts are used: gap hull and difference surface. Gap hull represents the displacement space characterizing all possible relative displacements in a joint. Difference surface simplifies the study of contact between parts of that joint. A bijective relationship between these two concepts is developed and exploited. Two experimental methods are developed to validate these theoretical concepts. The first consists of measuring relative displacements between two parts of a planar joint using a measuring system designed specifically for this study. Results obtained from the first method are validated by comparing with the results of the second method in which the contacting surfaces of the planar joint are measured.
Benchmarking PRAISE-CANDU 1.0 With Nuclear Risk Based Inspection Methodology Project Fatigue Cases
Authors: Duan Xinjian , Wang Min , Kozluk Michael J.
Published: August 2014

A probabilistic fracture mechanics (PFM) code, PRAISE-CANDU 1.0, has been developed under a software quality assurance (QA) program in full compliance with Canadian Standards Association (CSA) N286.7-99, and was initially released in June 2012 and officially approved for use in August 2013. Extensive verification and validation has been performed on PRAISE-CANDU 1.0 for the purpose of software QA. This paper presents the fatigue benchmarking against NURBIM (nuclear risk based inspection methodology for passive components) fatigue cases between PRAISE-CANDU 1.0 and six other PFM codes. This benchmarking is considered to be an important element of the validation of PRAISE-CANDU. Excellent agreement is observed in spite of the differences between the codes. The comparison of the predicted leak probability at the 40th year shows that PRAISE-CANDU not only captures the same trend but also bounds (higher predicted failure probability) the majority of the NURBIM results. In addition to the leak probability, the rupture probability, and uncertainty analysis, which were not reported in the NURBIM Project, are also calculated with PRAISE-CANDU and presented.
Absolute/Convective Instability Transition in a Backward Facing Step Combustor: Fundamental Mechanism and Influence of Density Gradient
Authors: Manoharan Kiran , Hemchandra Santosh
Published: August 2014

Hydrodynamic instabilities of the flow field in lean premixed gas turbine combustors can generate velocity perturbations that wrinkle and distort the flame sheet over length scales that are smaller than the flame length. The resultant heat release oscillations can then potentially result in combustion instability. Thus, it is essential to understand the hydrodynamic instability characteristics of the combustor flow field in order to understand its overall influence on combustion instability characteristics. To this end, this paper elucidates the role of fluctuating vorticity production from a linear hydrodynamic stability analysis as the key mechanism promoting absolute/convective instability transitions in shear layers occurring in the flow behind a backward facing step. These results are obtained within the framework of an inviscid, incompressible, local temporal and spatio-temporal stability analysis. Vorticity fluctuations in this limit result from interaction between two competing mechanisms—(1) production from interaction between velocity perturbations and the base flow vorticity gradient and (2) baroclinic torque in the presence of base flow density gradients. This interaction has a significant effect on hydrodynamic instability characteristics when the base flow density and velocity gradients are colocated. Regions in the space of parameters characterizing the base flow velocity profile, i.e., shear layer thickness and ratio of forward to reverse flow velocity, corresponding to convective and absolute instability are identified. The implications of the present results on understanding prior experimental studies of combustion instability in backward facing step combustors and hydrodynamic instability in other flows such as heated jets and bluff body stabilized flames is discussed.
Hydrogen Enriched Combustion Testing of Siemens Industrial SGT-400 at Atmospheric Conditions
Authors: Lam Kam-Kei , Geipel Philipp , Larfeldt Jenny
Published: August 2014

In order to further extend the turbine fuel flex capability, a test under atmospheric conditions of a full-scale SGT-400 burner was performed to study the combustion behavior when operating on hydrogen enriched natural gas (NG). A high speed camera was installed in the rig to investigate the flame dynamics on different operation conditions. NOx emissions were measured for all presented conditions. The combustion system was instrumented with thermocouples on all the key locations to allow flame position monitoring and to avoid flame attachment on the hardware. Further measurements included static pressure probes to monitor combustor pressure drop. The test was conducted in a systematic matrix format to include the most important combustion parameters in order to identify their individual effects on the combustion behaviors. The quantity of hydrogen in natural gas, fuel split, air preheat temperature, air reference velocity and flame temperature were the combustion related variables studied in the presented test campaign. The volumetric hydrogen quantity could be increased to 30% maintaining stable operation for all measured conditions. Higher hydrogen contents up to 80 vol. % were reached without flash back tendency. A glowing spark igniter prevented testing at even higher hydrogen contents. Hydrogen enriched gas showed higher NOx emissions and improved blowout limit. Hydrogen blending in the fuel also reduced the combustor pressure drop, lowered the prechamber temperature and raised the pilot tip temperature.
Operational Modal Analysis of Torsional Modes in Rotating Machinery
Authors: Peter Carden Eoin , Lindblad Mattias
Published: August 2014

Traditional experimental modal testing techniques rely on controlled and measured excitation together with measured responses in order to identify the mode shape, natural frequency, and damping factor of each mode. Applying a controlled and measured excitation to a rotor train when in operation is logistically difficult and especially challenging in the field. Operational modal analysis (OMA) identifies the modal parameters of a system from measurement of response due to some (unknown) excitation. OMA has proven successful over the past several decades on nonrotating structures but has relatively rarely been applied to rotating machinery. Case studies are presented demonstrating the use of OMA in identifying torsional modes on an electric motor driven reciprocating compressor, on a diesel engine driven fire water pump, and on a marine propulsion system. In contrast to lateral modes, torsional modes of rotor trains are typically not speed dependent. However, phenomena exist whereby the torsional modes may be different at stand still, off-load and at different loads. The case studies provide examples of such phenomena and also of significant differences between predicted and measured behavior which suggests that improvements in industrial practice would be beneficial. Such improvements should be based on reconciliation of measured and predicted behavior and OMA offers a valuable tool to facilitate this. OMA provides a significant benefit in investigating and understanding torsional behavior in operation.
Large Eddy Simulation on the Interactions of Wake and Film-Cooling Near a Leading Edge
Authors: Sarkar S. , Babu Harish
Published: August 2014

The unsteady flow physics due to interactions between a separated shear layer and film cooling jet apart from excitation of periodic passing wake are studied using large eddy simulation (LES). An aerofoil of constant thickness with rounded leading edge induced flow separation, while film cooling jets were injected normal to the crossflow a short distance downstream of the blend point. Wake data extracted from precursor LES of flow past a cylinder are used to replicate a moving bar that generates wakes in front of a cascade (in this case, an infinite row of the model aerofoils). This setup is a simplified representation of rotor-stator interaction in a film cooled gas turbine. The results of numerical simulation are presented to elucidate the formation, convection and breakdown of flow structures associated with the highly anisotropic flow involved in film cooling perturbed by convective wakes. The various vortical structures namely, horseshoe vortex, roller vortex, upright wake vortex, counter rotating vortex pair (CRVP), and downward spiral separation node (DSSN) vortex associated with film cooling are resolved. The effects of wake on the evolution of these structures are then discussed.
Inconsistent Stability of Newmark's Method in Structural Dynamics Applications
Authors: Wiebe Richard , Stanciulescu Ilinca
Published: August 2014

The stability of numerical time integrators, and of the physical systems to which they are applied, are normally studied independently. This conceals a very interesting phenomenon, here termed inconsistent stability, wherein a numerical time marching scheme predicts a stable response about an equilibrium configuration that is, in fact, unstable. In this paper, time integrator parameters leading to possible inconsistent stability are first found analytically for conservative systems (symmetric tangent stiffness matrices), then several structural arches with increasing complexity are used as numerical case studies. The intention of this work is to highlight the potential for this unexpected, and mostly unknown, behavior to researchers studying complex dynamical systems, especially through time marching of finite element models. To allow for direct interpretation of our results, the work is focused on the Newmark time integrator, which is commonly used in structural dynamics.
Optimization of Test Parameters That Influence Erosive Wear Behaviors of Glass Fiber-Reinforced Epoxy Composites by Using the Taguchi Method
Authors: Bagci Mehmet , Imrek Huseyin , Mashi Khalfan Omari
Published: August 2014

This study describes the development of a multicomponent composite system consisting of thermoplastic epoxy resin reinforced with E-glass fiber and silicon dioxide (SiO2) particles and investigates its erosion behavior under different operating conditions. Due to the increasing importance of composites in engineering applications and the need to tackle solid particle erosion in various industrial sectors, the study aims at finding how these composites behave in such type of wear. The composite specimens used for the tests were classified into three types; pure glass fiber (GF)–epoxy, those with addition of SiO2 particles at an amount of 15% and the last group had SiO2 particles added at 30% of the resin used for the materials. The experiments were carried out by selecting three different impact velocities, three different impingement angles, and angular alumina abrasive particles having approximate sizes of 200 μm. The fiber directions used were 0/90/0 and 45/ − 45/45. SEM views belonging to the specimens were taken before and after the tests in order to investigate the differences and the causes of the surface damages. Moreover, it is found that the Taguchi's robust orthogonal array method provides a simple, systematic, and efficient methodology for the optimization of the erosion wear parameters. At the end of the tests, the most significant factor in affecting the erosion rate is found to be the impingement angle, followed by the impact velocity, fiber direction, and filler material.
Kinematic Analysis of Basic Rhythmic Movements of Hip-hop Dance: Motion Characteristics Common to Expert Dancers
Authors: Sato Nahoko , Nunome Hiroyuki , Ikegami Yasuo
Published: August 2014

In hip-hop dance contests, a procedure for evaluating performances has not been clearly defined, and objective criteria for evaluation are necessary. It is assumed that most hip-hop dance techniques have common motion characteristics by which judges determine the dancer’s skill level. This study aimed to extract motion characteristics that may be linked to higher evaluations by judges. Ten expert and 12 nonexpert dancers performed basic rhythmic movements at a rate of 100 beats per minute. Their movements were captured using a motion capture system, and eight judges evaluated the performances. Four kinematic parameters, including the amplitude of the body motions and the phase delay, which indicates the phase difference between two joint angles, were calculated. The two groups showed no significant differences in terms of the amplitudes of the body motions. In contrast, the phase delay between the head motion and the other body parts’ motions of expert dancers who received higher scores from the judges, which was approximately a quarter cycle, produced a loop-shaped motion of the head. It is suggested that this slight phase delay was related to the judges’ evaluations and that these findings may help in constructing an objective evaluation system.
Considerations for Single and Double Leg Drop Jumps: Bilateral Deficit, Standardizing Drop Height, and Equalizing Training Load
Authors: Pain Matthew T.G.
Published: August 2014

Bilateral deficit is well documented; however, bilateral deficit is not present in all tasks and is more likely in dynamic activities than isometric activities. No definitive mechanism(s) for bilateral deficit is known but an oft cited mechanism is lower activation of fast twitch motor units. The aim of this study was to produce comparable and consistent one and two legged drop jumps to examine bilateral deficit in elite power athletes and elite endurance athletes. Seven power athletes and seven endurance athletes performed single and double leg drop jumps from a range of heights that equalized loading per leg in terms of: height dropped, energy absorbed, and momentum absorbed. Force and motion data were collected at 800 Hz. Bilateral deficit for jump height, peak concentric force, and peak concentric power were calculated. Power athletes had a significantly greater (P < .05) bilateral deficit for jump height and peak power, possibly due to power athletes having more fast twitch motor units, however, endurance athletes generally had a bilateral surfeit which could confound this inference. Results indicate that equalizing loading by impulse per leg is the most appropriate and that a consistent drop height can be obtained with a short 10 minute coaching session.
Social Environmental Influences on Physical Activity of Children With Autism Spectrum Disorders
Authors: Schenkelberg Michaela A. , Rosenkranz Richard R. , Milliken George A. , Dzewaltowski David A.
Published: August 2014

Background:

Children with Autism Spectrum Disorders (ASD) may be at greater risk for not meeting physical activity (PA) guidelines than neurotypical children (NT). The purpose of this study was to explore setting (free play versus organized) and social group composition influences on PA of children with ASD during summer camp.

Methods:

Data were collected on 6 ASD and 6 NT boys (aged 5 to 6 years) attending an inclusive summer camp. During free play and organized activity, research assistants observed the camp’s social environment and children’s PA using a modified version of the Observational System for Recording Physical Activity of Children—Preschool version.

Results:

In free play, children with ASD spent significantly less time in Moderate-Vigorous PA (MVPA) while with a peer (1.2%), compared with a peer group (11.5%) or alone (13.2%). They demonstrated significantly more Light-Moderate-Vigorous PA (LMVPA) while in a solitary social context (68.2%) compared with alone with an adult (25.8%), alone with a peer (34.8%), or with a peer group (28.2%). No significant differences were noted during organized activity.

Conclusion:

Features of the social environment may influence PA levels of children with ASD. Specifically, certain social group contexts may be more PA-promoting than others depending on the setting.
Recreational Exercise Before and During Pregnancy in Relation to Plasma C-Reactive Protein Concentrations in Pregnant Women
Authors: Wang Yan , Cupul-Uicab Lea A. , Rogan Walter J. , Eggesbo Merete , Travlos Gregory , Wilson Ralph , Longnecker Matthew P.
Published: August 2014

Background:

Pregnant women who are physically active have a lower risk of preeclampsia and gestational diabetes than women who are less active. One possible mechanism is a reduction in low-grade inflammation, as measured by plasma concentrations of C-reactive protein (CRP). The association between exercise and CRP in pregnant women, however, has not been adequately investigated.

Methods:

A total of 537 pregnant women, enrolled around the 17th week of gestation in the Norwegian Mother and Child Cohort Study in 2003 to 2004, were studied. Self-reported recreational exercise was recalled for both 3 months before pregnancy and early pregnancy. The total energy expenditure from recreational exercise (total recreational exercise, metabolic equivalent of task [MET]-hr/week) was estimated, and low-, moderate- and vigorous-intensity exercise was defined. Plasma CRP concentrations were measured during pregnancy.

Results:

In adjusted linear regression models, mean CRP concentration was 1.0% lower [95% CI = –1.9% to 0.2%] with each 1 MET-hr/week of total recreational exercise before pregnancy. In addition, vigorous-intensity exercise before pregnancy was more strongly related to a reduction in CRP levels than low- or moderate-intensity exercise. However, we observed no association between recreational exercise during pregnancy and plasma CRP levels.

Conclusion:

Recreational exercise before pregnancy, especially vigorous exercise, may reduce the risk of maternal inflammation during pregnancy.
Managing Diversity to Provide Culturally Safe Sport Programming: A Case Study of the Canadian Red Cross’s Swim Program
Authors: Rich Kyle A. , Giles Audrey R.
Published: August 2014

This article examines the piloting of a cultural safety training module in the Canadian Red Cross’s (CRC’s) Water Safety Instructor Development Program. Thematic analysis of interviews with program participants and facilitators revealed two main themes: Inclusion is important and valued by instructors, and accommodation for cultural and ethnic diversity is difficult to achieve in aquatics settings. Doherty and Chelladurai’s (1999) framework was used to understand the strengths and weaknesses of the pilot module. In conclusion, the authors propose that cultural safety training for the instructors alone will not lead to the provision of culturally safe sport; rather, there needs to be a change in the overall organizational culture in which the CRC’s programs are offered if they are to succeed. These findings make three contributions to the literature. First, the authors bridge the existing bodies of literature on critical Whiteness theory and sport management literature that addresses the management of diversity. Second, the authors explore the novel application of cultural safety training for instructors of a sport program. Finally, the authors offer recommendations to enable the development of an organizational culture that is facilitative and supportive with respect to inclusion (i.e., is welcoming) and accommodation (i.e., is flexible and adaptable) of cultural and ethnic diversity in aquatics programming.
A method for building self-folding machines
Authors: Felton S. , Tolley M. , Demaine E. , Rus D. , Wood R.
Published: August 2014

Folding robots and metamaterials

The same principles used to make origami art can make self-assembling robots and tunable metamaterials—artificial materials engineered to have properties that may not be found in nature (see the Perspective by You). Felton
et al.
made complex self-folding robots from flat templates. Such robots could potentially be sent through a collapsed building or tunnels and then assemble themselves autonomously into their final functional form. Silverberg
et al.
created a mechanical metamaterial that was folded into a tessellated pattern of unit cells. These cells reversibly switched between soft and stiff states, causing large, controllable changes to the way the material responded to being squashed.

Science
, this issue p.
644
, p.
647
; see also p.
623
A million spiking-neuron integrated circuit with a scalable communication network and interface
Authors: Merolla Paul A. , Arthur John V. , Alvarez-Icaza Rodrigo , Cassidy Andrew S. , Sawada Jun , Akopyan Filipp , Jackson Bryan L. , Imam Nabil , Guo Chen , Nakamura Yutaka , Brezzo Bernard , Vo Ivan , Esser Steven K. , Appuswamy Rathinakumar , Taba Brian , Amir Arnon , Flickner Myron D. , Risk William P. , Manohar Rajit , Modha Dharmendra S.
Published: August 2014

Modeling computer chips on real brains

Computers are nowhere near as versatile as our own brains. Merolla
et al.
applied our present knowledge of the structure and function of the brain to design a new computer chip that uses the same wiring rules and architecture. The flexible, scalable chip operated efficiently in real time, while using very little power.

Science
, this issue p.
668
Polyunsaturated phospholipids facilitate membrane deformation and fission by endocytic proteins
Authors: Pinot Mathieu , Vanni Stefano , Pagnotta Sophie , Lacas-Gervais Sandra , Payet Laurie-Anne , Ferreira Thierry , Gautier Romain , Goud Bruno , Antonny Bruno , Barelli Hélène
Published: August 2014

Bending the benefits of polyunsaturates

We have often heard that it is beneficial to eat polyunsaturated fatty acids. We also know that some organelles such as synaptic vesicles are extremely rich in polyunsaturated lipids. However, what polyunsaturated lipids do in our body is unclear. Using cell biology, biochemical reconstitutions, and molecular dynamics, Pinot
et al.
show that polyunsaturated phospholipids can change the response of membranes to proteins involved in membrane curvature sensing, membrane shaping, and membrane fission. Polyunsaturated phospholipids make the plasma membrane more amenable to deformation; facilitate endocytosis; and, in reconstitution experiments, increased membrane fission by the dynamin-endophilin complex.

Science
, this issue p.
693
Beyond blob-ology
Authors: Smith Martin T. J. , Rubinstein John L.
Published: August 2014

Advanced cryo–electron microscopy yields high-resolution structures of proteins
Folding structures out of flat materials
Authors: You Zhong
Published: August 2014

Reconfigurable machines and internally structured materials can be created through folding

[Also see Reports by

Felton
et al.

and

Silverberg
et al.

]
The innermost secrets of root development
Authors: Mellor Nathan , Bishopp Anthony
Published: August 2014

Local biosynthesis and mutual inhibition between plant hormones pattern root tissues

[Also see Research Article by

De Rybel
et al.

]
A splicing magic bullet
Authors: Vigevani Luisa , Valcárcel Juan
Published: August 2014

Drugs that modulate RNA splicing are potential therapeutics for spinal muscular atrophy

[Also see Report by

Naryshkin
et al.

]
In praise of power
Authors: Smith Kirk R.
Published: August 2014

The importance of energy for development is underscored by the United Nations declaration of 2014 to 2024 as the Decade of Sustainable Energy for All. Among the goals is to provide universal access to electricity and clean cooking. Each laudable in itself, the two goals actually overlap.
Building a cheaper, better census
Authors: Mervis Jeffrey
Published: August 2014

Statistical agencies worldwide are trying to meet demand for cost-savings without harming quality.
In the battle for fitness, being smart doesn't always pay
Authors: Pennisi Elizabeth
Published: August 2014

Studies of individual animals in the wild suggest that higher cognition has evolutionary trade-offs.
New recipe produces ammonia from air, water, and sunlight
Authors: Service Robert F.
Published: August 2014

Catalytic approach could eliminate CO
2
emissions from the key step in making fertilizer.
The brain chip
Authors: Service Robert F.
Published: August 2014

Microprocessors modeled on networks of nerve cells promise blazing speed at incredibly low power—if they live up to hopes.
Advances in Neurotechniques: Methods that Reveal the Structure and Function of the Brain
Authors: Deisseroth Karl , Gradinaru Viviana
Published: August 2014

Elucidating the mind's inner workings is one of the remaining challenges facing scientists today. Since Ramó Cajal's first illustrations of neuronal structures, neuroscientists have benefited from new ways to visualize the microscopic components within the brain. The development of new, advanced imaging techniques holds the promise for elucidating a better understanding of the how the brain works. Already, cutting-edge tools such as optogenetics and CLARITY offer researchers novel methods for peering into the structure and function of the brain. This webinar will explore the most recent neurotechniques and how these are being used to advance our knowledge of the brain.

View the Webinar
Serum Neutralization Assay Can Efficiently Replace Plaque Reduction Neutralization Test for Detection and Quantitation of West Nile Virus Antibodies in Human and Animal Serum Samples
Authors: Di Gennaro Annapia , Lorusso Alessio , Casaccia Claudia , Conte Annamaria , Monaco Federica , Savini Giovanni
Published: August 2014

A serum neutralization assay (SN) was compared with the official plaque reduction neutralization test for the quantitation of West Nile virus antibodies. A total of 1,348 samples from equid sera and 38 from human sera were tested by these two methods. Statistically significant differences were not observed, thus supporting the use of SN for routine purposes.
Clinical Characteristics Associated with Mycoplasma genitalium among Female Sex Workers in Nairobi, Kenya
Authors: Gomih-Alakija Ayodele , Ting Jie , Mugo Nelly , Kwatampora Jessie , Getman Damon , Chitwa Michael , Patel Suha , Gokhale Mugdha , Kimani Joshua , Behets Frieda S. , Smith Jennifer S.
Published: August 2014

The prevalence of
Mycoplasma genitalium
is high in vulnerable populations of women in low-resource settings. However, the epidemiology of infection in these populations is not well established. To determine the prevalence of
Mycoplasma genitalium
and its association with cervical cytology and other correlates, we recruited 350 female sex workers (FSW) who were 18 to 50 years old in Nairobi, Kenya, for a cross-sectional study. A questionnaire was administered at baseline to obtain information on sociodemographics and sexual behaviors. Women underwent a pelvic exam, during which a physician collected cervical-exfoliation samples for conventional cytology and sexually transmitted infection (STI) testing. Samples were tested for
M. genitalium
and other STI organisms (
Chlamydia trachomatis
,
Neisseria gonorrhoeae
,
Trichomonas vaginalis
) and the E6/E7 mRNA of human papillomavirus (HPV) by Aptima nucleic amplification assays. The prevalence of
M. genitalium
was 12.9%. FSW who engaged in sexual intercourse during menses were less likely to have
M. genitalium
infection than those who did not (odds ratio [OR], 0.3; 95% confidence interval [95% CI], 0.1, 0.9).
M. genitalium
was also less prevalent among FSW who had worked in prostitution for >5 years (6.2%) than among those who had worked for <3 years (17.6%) (OR, 0.3; 95% CI, 0.1, 0.8). FSW who reported more frequent condom use were more likely to be infected with
M. genitalium
than those who reported less frequent use (OR, 3.8; 95% CI, 1.2, 11.6). These correlates differ from those found in
M. genitalium
studies conducted with FSW from West Africa and China. Further longitudinal analyses assessing associations with persistent
M. genitalium
infection are needed.
Human Rhinovirus 16 Causes Golgi Apparatus Fragmentation without Blocking Protein Secretion
Authors: Mousnier Aurelie , Swieboda Dawid , Pinto Anaïs , Guedán Anabel , Rogers Andrew V. , Walton Ross , Johnston Sebastian L. , Solari Roberto
Published: August 2014

The replication of picornaviruses has been described to cause fragmentation of the Golgi apparatus that blocks the secretory pathway. The inhibition of major histocompatibility complex class I upregulation and cytokine, chemokine and interferon secretion may have important implications for host defense. Previous studies have shown that disruption of the secretory pathway can be replicated by expression of individual nonstructural proteins; however the situation with different serotypes of human rhinovirus (HRV) is unclear. The expression of 3A protein from HRV14 or HRV2 did not cause Golgi apparatus disruption or a block in secretion, whereas other studies showed that infection of cells with HRV1A did cause Golgi apparatus disruption which was replicated by the expression of 3A. HRV16 is the serotype most widely used in clinical HRV challenge studies; consequently, to address the issue of Golgi apparatus disruption for HRV16, we have systematically and quantitatively examined the effect of HRV16 on both Golgi apparatus fragmentation and protein secretion in HeLa cells. First, we expressed each individual nonstructural protein and examined their cellular localization and their disruption of endoplasmic reticulum and Golgi apparatus architecture. We quantified their effects on the secretory pathway by measuring secretion of the reporter protein Gaussia luciferase. Finally, we examined the same outcomes following infection of cells with live virus. We demonstrate that expression of HRV16 3A and 3AB and, to a lesser extent, 2B caused dispersal of the Golgi structure, and these three nonstructural proteins also inhibited protein secretion. The infection of cells with HRV16 also caused significant Golgi apparatus dispersal; however, this did not result in the inhibition of protein secretion.

IMPORTANCE
The ability of replicating picornaviruses to influence the function of the secretory pathway has important implications for host defense. However, there appear to be differences between different members of the family and inconsistent results when comparing infection with live virus to expression of individual nonstructural proteins. We demonstrate that individual nonstructural HRV16 proteins, when expressed in HeLa cells, can both fragment the Golgi apparatus and block secretion, whereas viral infection fragments the Golgi apparatus without blocking secretion. This has major implications for how we interpret mechanistic evidence derived from the expression of single viral proteins.
The Epstein-Barr Virus (EBV) Glycoprotein B Cytoplasmic C-Terminal Tail Domain Regulates the Energy Requirement for EBV-Induced Membrane Fusion
Authors: Chen Jia , Zhang Xianming , Jardetzky Theodore S. , Longnecker Richard
Published: August 2014

The entry of enveloped viruses into host cells is preceded by membrane fusion, which in Epstein-Barr virus (EBV) is thought to be mediated by the refolding of glycoprotein B (gB) from a prefusion to a postfusion state. In our current studies, we characterized a gB C-terminal tail domain (CTD) mutant truncated at amino acid 843 (gB843). This truncation mutant is hyperfusogenic as monitored by syncytium formation and in a quantitative fusion assay and is dependent on gH/gL for fusion activity. gB843 can rescue the fusion function of other glycoprotein mutants that have null or decreased fusion activity in epithelial and B cells. In addition, gB843 requires less gp42 and gH/gL for fusion, and can function in fusion at a lower temperature than wild-type gB, indicating a lower energy requirement for fusion activation. Since a key step in fusion is the conversion of gB from a prefusion to an active postfusion state by gH/gL, gB843 may access this activated gB state more readily. Our studies indicate that the gB CTD may participate in the fusion function by maintaining gB in an inactive prefusion form prior to activation by receptor binding.

IMPORTANCE
Diseases resulting from Epstein-Barr virus (EBV) infection in humans range from the fairly benign disease infectious mononucleosis to life-threatening cancer. As an enveloped virus, EBV must fuse with a host cell membrane for entry and infection by using glycoproteins gH/gL, gB, and gp42. Among these glycoproteins, gB is thought to be the protein that executes fusion. To further characterize the function of the EBV gB cytoplasmic C-terminal tail domain (CTD) in fusion, we used a previously constructed CTD truncation mutant and studied its fusion activity in the context of other EBV glycoprotein mutants. From these studies, we find that the gB CTD regulates fusion by altering the energy requirements for the triggering of fusion mediated by gH/gL or gp42. Overall, our studies may lead to a better understanding of EBV fusion and entry, which may result in novel therapies that target the EBV entry step.
Attachment Protein G of an African Bat Henipavirus Is Differentially Restricted in Chiropteran and Nonchiropteran Cells
Authors: Krüger Nadine , Hoffmann Markus , Drexler Jan Felix , Müller Marcel Alexander , Corman Victor Max , Drosten Christian , Herrler Georg
Published: August 2014

Henipaviruses are associated with pteropodid reservoir hosts. The glycoproteins G and F of an African henipavirus (strain M74) have been reported to induce syncytium formation in kidney cells derived from a
Hypsignathus monstrosus
bat (HypNi/1.1) but not in nonchiropteran BHK-21 and Vero76 cells. Here, we show that syncytia are also induced in two other pteropodid cell lines from
Hypsignathus monstrosus
and
Eidolon helvum
bats upon coexpression of the M74 glycoproteins. The G protein was transported to the surface of transfected chiropteran cells, whereas surface expression in the nonchiropteran cells was detectable only in a fraction of cells. In contrast, the G protein of Nipah virus is transported efficiently to the surface of both chiropteran and nonchiropteran cells. Even in chiropteran cells, M74-G was predominantly expressed in the endoplasmic reticulum (ER), as indicated by colocalization with marker proteins. This result is consistent with the finding that all N-glycans of the M74-G proteins are of the mannose-rich type, as indicated by sensitivity to endo H treatment. These data indicate that the surface transport of M74-G is impaired in available cell culture systems, with larger amounts of viral glycoprotein present on chiropteran cells than on nonchiropteran cells. The restricted surface expression of M74-G explains the reduced fusion activity of the glycoproteins of the African henipavirus. Our results suggest strategies for the isolation of infectious viruses, which is necessary to assess the risk of zoonotic virus transmission.

IMPORTANCE
Henipaviruses are highly pathogenic zoonotic viruses associated with pteropodid bat hosts. Whether the recently described African bat henipaviruses have a zoonotic potential as high as that of their Asian and Australian relatives is unknown. We show that surface expression of the attachment protein G of an African henipavirus, M74, is restricted in comparison to the G protein expression of the highly pathogenic Nipah virus. Transport to the cell surface is more restricted in nonchiropteran cells than it is in chiropteran cells, explaining the differential fusion activity of the M74 surface proteins in these cells. Our results imply that surface expression of viral glycoproteins may serve as a major marker to assess the zoonotic risk of emerging henipaviruses.
High Eomesodermin Expression among CD57
+
CD8
+
T Cells Identifies a CD8
+
T Cell Subset Associated with Viral Control during Chronic Human Immunodeficiency Virus Infection
Authors: Simonetta Federico , Hua Stéphane , Lécuroux Camille , Gérard Sandie , Boufassa Faroudy , Sáez-Cirión Asier , Pancino Gianfranco , Goujard Cécile , Lambotte Olivier , Venet Alain , Bourgeois Christine
Published: August 2014

During HIV infection, increased CD57 expression among CD8
+
T cells has been associated with immune senescence and defective immune responses. Interestingly, CD57-expressing CD8
+
T cells exhibit a dual profile, being simultaneously highly cytotoxic (terminally differentiated effectors) and poorly proliferative (replicative senescent). Recent publications point toward a positive role of CD57-expressing CD8
+
T cell subsets, presumably due to their high cytolytic activity. We further investigated the phenotype of CD57-expressing CD8
+
T cells in healthy donors and during HIV infection combining CD57 expression to Eomesodermin (EOMES), a T box transcription factor which determines, coordinately with T-bet, effector and memory CD8
+
T cell differentiation. We defined in healthy donors two functionally distinct CD57-expressing CD8
+
T cell subsets exhibiting different levels of EOMES expression: EOMES
hi
CD57
+
and EOMES
int
CD57
+
CD8
+
T cells. EOMES
hi
CD57
+
cells exhibited low cytotoxic activity but preserved proliferative capacity and interleukin 7 (IL-7) receptor expression, whereas EOMES
int
CD57
+
cells exhibited obvious cytotoxic functions and a more terminally differentiated phenotype. We next performed a similar analysis in different contexts of HIV infection: primary infected patients, long-term viremic patients, aviremic patients treated with antiretroviral therapy, and HIV controllers; we demonstrated a higher percentage of CD57-expressing cells in all HIV-infected patients regardless of virological status. When heterogeneity in EOMES expression among CD57 cells was taken into account, we detected significantly higher proportions of EOMES
hi
CD57
+
cells among HIV-specific and nonspecific CD8
+
T cells from HIV controllers than in aviremic antiretroviral-treated patients and viremic patients. Importantly, such a peculiar non-terminally differentiated EOMES
hi
CD57
+
phenotypic profile was associated with viral control.

IMPORTANCE
This study demonstrates that functional heterogeneity exists among CD57-expressing CD8 T cells, which include both terminally differentiated, highly cytotoxic EOMES
int
CD57
+
CD8
+
T cells and less differentiated EOMES
hi
CD57
+
CD8 T cells, which do not exhibit immediate cytotoxic functions but present high proliferative capacity. Interestingly, HIV controllers present a high proportion of EOMES
hi
CD57 cells among CD57-expressing HIV-specific CD8 T cells compared to both long-term viremic and aviremic antiretroviral therapy (ART)-treated patients, suggesting a beneficial role for this cell subset in viral control.
The potential for community-based health information exchange systems to reduce hospital readmissions
Authors: Vest Joshua R , Kern Lisa M , Silver Michael D , Kaushal Rainu ,   for the HITEC investigators
Published: August 2014

Background Hospital readmissions are common, costly, and offer opportunities for utilization reduction. Electronic health information exchange (HIE) systems may help prevent readmissions by improving access to clinical data by ambulatory providers after discharge from the hospital.

Objective We sought to determine the association between HIE system usage and 30-day same-cause hospital readmissions among patients who consented and participated in an operational community-wide HIE during a 6-month period in 2009–2010.

Methods We identified a retrospective cohort of hospital readmissions among adult patients in the Rochester, New York area. We analyzed claims files from two health plans that insure more than 60% of the area population. To be included in the dataset, patients needed to be continuously enrolled in the health plan with at least one encounter with a participating provider in the 6 months following consent to be included in the HIE system. Each patient appeared in the dataset only once and each discharge could be followed for at least 30 days.

Results We found that accessing patient information in the HIE system in the 30 days after discharge was associated with a 57% lower adjusted odds of readmission (OR 0.43; 95% CI 0.27 to 0.70). The estimated annual savings in the sample from averted readmissions associated with HIE usage was $605 000.

Conclusions These findings indicate that usage of an electronic HIE system in the ambulatory setting within 30 days after hospital discharge may effectively prevent hospital readmissions, thereby supporting the need for ongoing HIE efforts.
Atypical presentation of chronic granulomatous disease withBurkholderia cepacia
Authors: Vining Mac , Sharma Nirupma , Guill Margaret
Published: August 2014

Chronic granulomatous disease (CGD) is a rare inherited disorder of neutrophil oxidative burst. In patients with CGD, phagocyte destruction of catalase-producing organisms is impaired, resulting in recurrent and potentially fatal infections.Burkholderia cepacia, a catalase-producing organism, is known to infect patients with dysfunctional immune systems. We report a case of a 3-year-old boy with this rare infection that unravelled the diagnosis of CGD.
Intranasal tooth: ectopic eruption 1 year after maxillofacial trauma
Authors: Agrawal Mamta , Khan Tayyeb Sultan , Gupta Tulika , Khanna Shally
Published: August 2014

Injury to the permanent central incisors due to trauma in the maxillofacial region, though common, may result in an uncommon sequel. We report a case of traumatic injury in a 5-year-old child with displacement of the tooth bud into the nasal floor. The identification of ectopic tooth buds poses little diagnostic challenge due to the available imaging facilities, however, in the present case the ectopic bud remained unnoticed and resulted in ectopic eruption of the tooth in the nasal cavity 1 year later. This report highlights a rare case of nasal eruption of a permanent tooth and places stress on the need for close attention to detail during maxillofacial trauma for early detection and proper management.
Hymenoptera venom allergy: work disability and occupational impact of venom immunotherapy
Authors: Paolocci Giulia , Folletti Ilenia , Torén Kjell , Muzi Giacomo , Murgia Nicola
Published: August 2014

Objectives

Little is known about the Hymenoptera venom allergy impact on work ability and the effect of venom immunotherapy (VIT) on work. The objective of this study was to evaluate the prevalence and predictors of work disability in patients treated with VIT and the effects of VIT on occupational functioning.

Methods

181 patients, aged 18–71 years, treated with VIT while working, were investigated by questionnaire. Participants were classified into employed and self-employed and, based on work exposure to Hymenoptera, into three risk categories: high risk, occasionally high risk and low risk. Work disability was defined as having to have changed jobs/tasks and/or suffered economic loss because of Hymenoptera venom allergy. Predictors of work disability were assessed in logistic regression models.

Results

31 (17%) patients reported work disability. Being self-employed and having the severe reaction at work were associated with work disability (p<0.01). Having a high-risk job for exposure to Hymenoptera was a significant predictor of work disability (OR 2.66, 95% CI 1.04 to 6.75). 24% of patients referred a positive effect of VIT on work. Determinants of the positive effect of VIT on work were having a high-risk job for exposure to hymenoptera (OR 3.60, 95% CI 1.52 to 8.51) and having already concluded VIT (OR 2.82, 95% CI 1.30 to 6.14).

Conclusions

Hymenoptera venom allergy could determine work disability. Patients with Hymenoptera venom allergy having a high-risk job for exposure to Hymenoptera seem to have higher risk of work disability and refer more frequently a positive effect of VIT on work.