bluuebunny/crossref_metadata_2025 huggingface dataset:
Report onDrosophila melanogasterlarvae without functional tracheae
Authors: Wang Y. , Zuber R. , Oehl K. , Norum M. , Moussian B.
Published: March 2015

A network of tubes, the tracheal system, ensures circulation of oxygen and carbon dioxide in insects. A stabilizing chitinous cuticle lines this ectodermal tissue that commonly fills with gas shortly before hatching. In this study, we report onDrosophila melanogasterlarvae that lack a functional tracheal system through the reduction of the expression of the cuticle genekkvorsnslby specificRNAinterference in tracheal cells of the embryo. These embryos complete development and hatch arguing that functional tracheae are not required for embryogenesis. After hatching, larvae with dysfunctional tracheae ingest only little food and grow slowly. Without attaining the critical size for stage transition, a few of them moult to the next larval stage. We further show that hypoxia is induced in these larvae that conceptually switch to skin respiration. The rescue response is, however, futile and the respective larvae die latest after 4 days. Hence, a small body size and skin respiration per se are insufficient to ensure survival. Based on our data, we hypothesize that a low oxygen concentration entails a conflict between the developmental progress and a protective programme destined to restrict growth under hypoxia.D. melanogasterlarvae with dysfunctional tracheae will be useful to identify those factors accounting for the impact of respiration on growth and development ultimately allowing understanding these aspects of insect ecology.
White rhinoceros Ceratotherium simum horn development and structure: a deceptive optical illusion
Authors: Boy S. C. , Raubenheimer E.J. , Marais J. , Steenkamp G.
Published: March 2015

The alleged traditional medicinal properties of rhinoceros horn resulted in a dramatic escalation in rhinoceros poaching in South Africa. Despite the listing of all species of rhinoceros in the International Union for Conservation of Nature Red List of threatened animals, their numbers are still declining rapidly. Based on the assumption that rhinoceros' horn consists of a collection of hollow tubules and intertubular hollow spaces, which allow internal fluid distribution, a horn devaluation procedure through infusion of chemicals and dyes was recently introduced. This procedure is costly and has a mortality risk. This study study provides the first detailed description of the development and resultant structure of the rhinoceros horn. The unique solid structure which consists of a large number of tightly packed filaments is the result of the cellular orientation of squamous epithelium corneocytes. What was previously thought to be microtubules is an optical illusion created by the orientation of the corneocytes in the solid filaments. We contest the scientific basis for infusing chemicals into the rhinoceros horn as a deterrent for human use.
Impact of supply problems of preservative‐free glaucoma medications on patients and hospital staff
Authors: Shah Shima , Theodossiades Julia , Chapman Kristin , Murdoch Ian
Published: March 2015

Purpose

Glaucoma is a chronic ocular disease, which is usually managed with long‐term daily medical therapy, in the form of eye drops. Patients who are intolerant to preservatives in topical medicines require preservative‐free versions. From early 2011 patients attending Moorfields Eye Hospital, London, UK, started to report recurring problems with the supply of the following preservative‐free glaucoma medications: Timolol 0.25% (Timoptol 0.25%, MSD UK); Dorzolamide (Trusopt, MSD UK); Dorzolamide and Timolol 0.5% (Cosopt, MSD UK). This study investigates the impact of the supply problems of these medications at Moorfields Eye Hospital from a patient, administrative and clinical perspective.

Methods

Information was sought by interviewing both patients and hospital staff, and by a retrospective case note review between April 2010 and May 2013.

Results

Many hospital roles, both administrative and clinical, were involved in attempting to resolve the impact of the supply problems. All staff reported a considerable increase in their workload. At the peak of the problem, the glaucoma secretaries received about 150 enquiries per week.

A review of 83 sets of patient notes, retrieved from a random sample of 125 patients, showed that 22% encountered a supply problem. Of these, more than one‐third attended Moorfields Eye Hospital Accident & Emergency (A&E) for repeat supplies and 89% eventually had their medication changed. In telephone interviews with 39 of a random sample of 50 patients (a subset of the 83 notes retrieved), 59% of the interviewees reported a supply problem. Of these, one‐third attended Moorfields Eye Hospital A&E for repeat supplies and half eventually required an alternative medication. Some patients reported going to considerable lengths to obtain ongoing supplies in the community.

Conclusions

This study shows that medication supply problems can have a major impact on patients and hospital services. Supply problems occur across many fields of medicine and with increasing frequency. The findings of this study highlight the importance of early communication of impending shortages between manufacturers and the Department of Health, as recommended in the best practice guidelines. In order to minimise the impact of medicine shortages on patients, clinicians and administrative staff, hospitals need immediate notification of potential supply problems and clear updates on supply resolution. In addition, hospitals should consider nominating an individual as a contact point for patient enquiries regarding medicine supply problems.
Unrelated donor hematopoietic stem cell transplantation for infantile enteropathy due to IL‐10/IL‐10 receptor defect
Authors: Gassas Adam , Courtney Sarah , Armstrong Christine , Kapllani Erilda , Muise Aleixo M. , Schechter Tal
Published: March 2015

Recent advances in genetic diagnosis have identified mutations in gene encoding interleukin‐10 (IL‐10) and IL‐10 receptor (IL‐10R) proteins as a cause for early‐onset enterocolitis leading to hyperinflammatory immune response. Allogeneic HSCT offers a potential cure; however, it was only performed in a few infants and mainly from family‐related donors. We report a case of a girl who presented very early in life with severe infantile enterocolitis. Gene sequencing confirmed IL‐10R defect. Her older sister died at 13 months of age from severe undiagnosed enterocolitis. There was no family donor. An unrelated search identified a potential 10/10 high‐resolution HLA‐matched donor. There was some delay in donor activation because IL‐10R defect was not on the standard list of indications for unrelated HSCT. Our patient received the unrelated HSCT at seven months of age, and she is currently nine months after transplant and doing very well. Because HSCT is the curative option of choice for this disorder, we encourage adding IL‐10 and IL‐10R protein defects to the list of HSCT indications for unrelated donor procurement.
A Novel Microsensor for Measuring Angular Distribution of Radiative Intensity
Authors: Murphy Thomas E. , Pilorz Stuart , Prufert‐Bebout Leslie , Bebout Brad
Published: March 2015

This article presents the design, construction and characterization of a novel type of light probe for measuring the angular radiance distribution of light fields. The differential acceptance angle (DAA) probe can resolve the directionality of a light field in environments with steep light gradients, such as microbial mats, without the need to remove, reorient, and reinsert the probe, a clear advantage over prior techniques. The probe consists of an inner irradiance sensor inside a concentric, moveable light‐absorbing sheath. The radiative intensity in a specific zenith direction can be calculated by comparing the irradiance onto the sensor at different acceptance angles. We used this probe to measure the angular radiance distribution of two sample light fields, and observed good agreement with a conventional radiance probe. The DAA probe will aid researchers in understanding light transfer physics in dense microbial communities and expedite validation of numerical radiative transfer models for these environments.
‘Keeping meself to meself’ – How Social Networks Can Influence Narratives of Stigma and Identity for Long‐term Sickness Benefits Recipients
Authors: Garthwaite Kayleigh
Published: March 2015

This article focuses upon social networks and their relationship to stigma and identity for long‐term sickness benefits recipients in the North East of England. Drawing on empirical qualitative research with long‐term sickness benefits recipients, this article demonstrates how the co‐construction of stigma is fundamental in shaping how long‐term sickness benefits recipients participate in social networks with friends, family and the community. The findings support the idea that the stigma of receiving benefits can be contrasted with nostalgia for the social elements of employment. Utilizing the work of Goffman, the article focuses on how the stigma and shame felt at receiving sickness benefits for an extended period of time interacts with social networks and identity. Reluctance to disclose a claimant identity to friends and family could lead to social isolation and a perceived need to ‘keep meself to meself’ which can be linked to a wider rhetoric surrounding benefits recipients that characterizes them as ‘scroungers’.
Resolving the daratumumab interference with blood compatibility testing
Authors: Chapuy Claudia I. , Nicholson Rachel T. , Aguad Maria D. , Chapuy Bjoern , Laubach Jacob P. , Richardson Paul G. , Doshi Parul , Kaufman Richard M.
Published: March 2015

BACKGROUND

Daratumumab (DARA), a promising novel therapy for multiple myeloma, is an IgG1κ monoclonal antibody that recognizes CD38 on myeloma cells. During routine compatibility testing, we observed that the plasma of five of five DARA‐treated patients demonstrated a positive antibody screen and panreactivity on red blood cell (RBC) panel testing. We hypothesized that the observed panreactivity reflected DARA binding to CD38 on reagent RBCs, and we investigated methods to prevent this binding.

STUDY DESIGN AND METHODS

DARA binding to CD38+ or CD38– HL60 cells was assessed by flow cytometry. To remove cell surface CD38, cells were incubated with dithiothreitol (DTT) or trypsin. Soluble CD38 or anti‐DARA was used to neutralize DARA in solution. Routine blood bank serologic methods were used to test samples from DARA‐treated patients and normal plasma samples spiked with DARA and/or alloantibodies.

RESULTS

Normal plasma samples spiked with DARA (0.1‐10 µg/mL) and incubated with reagent RBCs recapitulated the interference observed with samples from DARA‐treated patients. Flow cytometry experiments confirmed DARA binding to CD38+ HL60 cells, but not to CD38– controls. DTT treatment of CD38+ HL60 cells reduced DARA binding by 92% by denaturing cell surface CD38. Treating DARA‐containing plasma with soluble CD38 or anti‐DARA idiotype also inhibited DARA binding.

CONCLUSION

DARA causes panreactivity in vitro by binding to CD38 on reagent RBCs. Treating reagent RBCs with DTT is a robust method to negate the DARA interference, enabling the safe provision of blood to DARA‐treated patients. Because DTT denatures Kell antigens, K– units are provided to these patients.
Chemical control of isolated invasive conifers using a novel aerial spot application method
Authors: Gous S , Raal P , Kimberley M O , Watt M S
Published: March 2015

Conifer species, which have formed the foundation of commercial forestry industry in many countries, are known to be invasive in natural ecosystems, especially in the Southern Hemisphere. Controlling isolated invasive conifers before they reach reproductive maturity is an essential element of any strategy that aims to reduce spread rate of these species. Using a novel helicopter‐mounted spot‐application gun, which delivers a precise dosage to the crown of each tree, the objective of this research was to test the efficacy of three triclopyr‐based treatments against the four most vigorous wilding conifer species (Pinus contorta, Pinus nigra, Pinus sylvestris and Pseudotsuga menziesii) under New Zealand field conditions. Herbicides tested were triclopyr at two different rates and a combination of triclopyr and picloram. Treated trees covered a wide range of heights (c. 0.5–16 m), and measurements of mortality taken two years post‐herbicide application were used to examine variation in efficacy of the herbicides. Successful treatment was defined by a mortality rate of 85% or higher. A logistic regression model was fitted to the mortality data and used to derive threshold tree heights at which 85% mortality occurred, H85. For all four species, the most effective treatment was application of 1000 ml of herbicide mixture per tree that contained 120 and 20 g, respectively, of the active ingredients triclopyr and picloram. There was a significant decline in efficacy of this treatment with increases in tree size for all four species. Values of H85 for this treatment were 7.4 m for P. nigra, 8.3 m for P. menziesii, 9.7 m for P. contorta and >10 m for P. sylvestris. The methods developed here could be used to effectively manage emerging conifer infestations before they become problematic.
Duality relations for hypergeometric series
Authors: Beukers Frits , Jouhet Frédéric
Published: March 2015

We explicitly give the relations between the hypergeometric solutions of the general hypergeometric equation and their duals, as well as similar relations for ‐hypergeometric equations. They form a family of very general identities for hypergeometric series. Although they were foreseen already by Bailey in the 1930s on analytic grounds, we give a purely algebraic treatment based on general principles in general differential and difference modules.
Robust numerical solutions of two singularly perturbed problems in mathematical biology
Authors: Nagarajan Shivaranjani , Miller John J. H. , Sigamani Valarmathi
Published: March 2015

In this paper, a numerical method is suggested for solving a mathematical modelВ for the process of cell proliferation and maturation and a model for determiningВ the expected time for the generation of action potentials in nerve cells by random synaptic inputs in the dendrites. Both these models give rise to singularlyВ perturbed delay dierential equations. The former is an initial value problemВ for a rst order singularly perturbed delay partial dierential equation, whileВ the latter is a boundary value problem for a second order singularly perturbedВ delay dierential equation. Numerical illustrations are provided.
Three-Dimensional Dynamic Model of TEHD Tilting-Pad Journal Bearing—Part I: Theoretical Modeling
Authors: Suh Junho , Palazzolo Alan
Published: March 2015

This paper is focused on a new modeling method of three-dimensional (3D) thermo-elasto-hydro-dynamic (TEHD) cylindrical pivot tilting-pad journal bearing (TPJB). Varying viscosity Reynolds equation and 3D energy equation are coupled via lubricant temperature and viscosity relationship. Three-dimensional finite element method (FEM) is adopted for the analysis of: (1) heat conduction in shaft and bearing pad, (2) thermal deformation of shaft and pad, (3) flexible bearing pad dynamic behavior, and (4) heat conduction, convection, and viscous shearing in thin lubricant film. For the computational efficiency, modal coordinate transformation is utilized in the flexible pad dynamic model, and pad dynamic behavior is represented only by means of modal coordinate. Fluid film thickness is calculated by a newly developed node based method, where pad arbitrary thermal and elastic deformation and journal thermal expansion are taken into account simultaneously. The main goal of this research is to provide more accurate numerical TPJB model than developed before so that the designers of rotating machinery are able to understand the bearing dynamic behavior and avoid unpredicted problem by selection of physical parameters.
Chaotification as a Means of Broadband Energy Harvesting With Piezoelectric Materials
Authors: Geiyer Daniel , Kauffman Jeffrey L.
Published: March 2015

Component miniaturization and reduced power requirements in sensors have enabled growth in the field of low-power ambient vibration energy harvesting. This work aims to increase bandwidth and power output beyond current techniques by inducing chaotic nonlinear phenomena and applying a low-power controller based on the method of Ott, Grebogi, and Yorke (OGY) to stabilize a chosen periodic orbit. Previously, researchers used a nonlinear piezomagnetoelastic beam in search of a large amplitude broadband voltage response, but chaos was strictly avoided. These large amplitude responses can deteriorate over time into low energy chaotic oscillations. Including chaos as a desirable property allows small perturbations to alter the behavior of a system dramatically, improving the dynamic response for energy harvesting. The nonlinear piezomagnetoelastic beam element described by a Duffing oscillator is extended to embrace chaotic motion more actively. By driving motion along a chaotic attractor, even single frequency excitation results in a theoretically infinite number of unstable periodic orbits that can be stabilized using small control inputs. The chosen orbit will be accessible from a large range of excitation frequencies and can be dynamically changed in real-time, potentially expanding the bandwidth of operation.
LQG Controller Design for Identified Wind Turbine Systems
Authors: Kim Young-Man
Published: March 2015

In this research, it is developed to design LQG controller for wind turbine systems which are identified with Predictor-Based System Identification (PBSID) technique. The PBSID technique works well under closed-loop condition, which is useful for a system requiring closed-loop operation due to safety reason. First, a wind turbine system is identified using PBSID technique in full range of wind speed. Afterwards, using the identified system matrices, 1-DOF LQG controller is designed. The controller enables power generation to track the optimal power trajectory of a system. Simulation is used to demonstrate its usefulness.
Design and Testing of a Portable Concussion Assessment Device
Authors: Zhu Yong , Thomas Evan
Published: March 2015

A concussion is a mild traumatic brain injury as a result from a blow to the head. From battlefields to football fields, concussions are unavoidable risks that occur on a daily basis. The goal of this research is to design and test the prototype of a portable concussion assessment device that can offer a quick indication of the state of concussion immediately after the concussion. Approximate Entropy (ApEn) values reflecting the amount of irregularity hiding in center-of-pressure (COP) oscillations will be used to calculate the index. The prototype will adopt a portable design and use the measurements of the load cells located at the four corners of the prototype. The test subject will be asked to stand on the device in normal stance for 30 seconds with their eyes closed. The COP oscillations will then be recorded. Based on the oscillation measurements, the ApEn index will be calculated and quickly displayed to indicate the state of concussion.
Hot Extrusion of Hollow Spur Gear of Magnesium Alloys
Authors: Hwang Yeong-Maw , Lin Sung-Hsiu
Published: March 2015

This study is to analyze the extrusion process of a hollow spur gear of magnesium alloys. A design criterion for the die geometry is first proposed for decreasing the extrusion load and increasing the filling ratio at the tooth tip of the product. Then, the Finite Element Analysis is used to simulate the flow pattern of the billet pushing through a port-hole, a welding chamber and finally a die bearing part. From a series of simulation results, the effect of the bridge length, bearing length, and the welding chamber height, etc. on the filling ratio, welding pressure, extrusion load, final temperature, etc. are discussed. Finally, hot extrusion experiments are conducted with a better die geometry to obtain a sound product. The experimental values of extrusion loads and filling ratios are compared with the analytical values to verify the validity of the analytical model.
The Configuration Recommendation Strategy Based on Similarity in Product Configuration for Manufacturing
Authors: Li Niya , Liu Yucheng , Zhang Jian
Published: March 2015

Product configuration technology is an important method for implementing Mass Customization paradigm. It used to configure personalized products within a short period of time by maximal utilization of original production resources. In the configuration process for meeting user requirements, it is very possible to get several configuration results from a product family. So, how to select the optimal configuration result is an inevitable issue for manufacture. In the light of the problem, this study provides a recommendation strategy so as to improve the productivity and the resource utilization of manufactory. The strategy is represented by Algorithm Recommend. It is given to select the optimal result by analyzing and comparing the degree of similarity between the configuration results and the historical data in manufacture. The degree of similarity integrates the configuration logic and the tree structure characteristics by using the weighted method. The final example is a symbolic application which proves that this recommendation strategy can help efficiently to find the optimal configuration result for manufacture.
Ceramic on-Ceramic Hip Implants: Analysis of Friction Induced Squeal
Authors: Sidebottom Mark , Allan D. G. , Paliwal Manish
Published: March 2015

Ceramic-on-Ceramic (CoC) bearings are an ideal choice for a total hip replacement because of the ceramic bearings’ longer wear life than Metal-on-Metal or Metal-on-Polyethylene bearings. Friction-induced squeaking has been reported in 1–10% of patients who have a ceramic-on-ceramic total hip replacement, which is a subject of annoyance. Many mechanisms have been proposed to address the squeaking phenomena in CoC hip replacements, but there is no consensus among researchers on the root cause behind the squeaking of hip implants. The goal of this study was to investigate the possible factors attributing to the hip squeak, and understand the underlying phenomenon based on the coupling stiffness of the bearing surface. Boundary conditions for the CoC hip bearing to produce audible noise were also identified. An explanted Stryker Trident CoC hip bearing that had been removed due to squeaking was analyzed visually and by computer simulation. Grey marks on the femoral head of the implant showed material transfer of titanium alloy onto the alumina head. Using modal analysis, the natural frequencies of all the components of the implant were determined. Random vibration analysis was conducted to identify the ideal boundary conditions for the CoC hip bearing.

The results from the modal analysis and calculated stiffness and damping coefficients were used in the mathematical two degree-of-freedom (DOF) model to calculate the velocity and position of the two masses in the system. State-Space plots of the parametric analysis were used to evaluate the stability of the system. Mathematical Analysis involved the investigation of the role of the frictional stick-slip phenomenon of the metal shell and ceramic liner on squeal. The size of the limit cycle provides an indication of the degree of severity of a noisy condition.

With only metallic shell affixed to the acetabulum constrained, the modal natural frequency was 3600 Hz which was very close to the free vibration results of the bearing. The Power Spectral Densities displayed the audible frequencies at 11.4 kHz. The limit cycle plots show that a variation in coupling contact stiffness has an influence on the behavior/stability of the system. The study underscored the relevance of material transfer on the bearing surface using the mathematical analysis by varying the coupling stiffness of the bearing surface. In addition, random vibration analysis in conjunction with the parametric analysis identified the ideal boundary condition to produce the squeal frequencies as observed by others.
Control of Slewing Motions of Flexible Structures Using Shape Memory Alloy
Authors: Janzen Frederic C. , Tusset Ângelo M. , Piccirillo Vinicius , Balthazar José M. , de Pontes Bento R. , Silveira Marcos , Brasil Reyolando M. L. R. F.
Published: March 2015

This paper presents the position and vibration control of a single flexible slewing structure driven by a DC motor at the slewing axis. The position is controlled over the current applied to the DC motor armature. To control the vibration of the flexible structure Shape Memory Alloys (SMA) are applied to them. The control is made through the State Dependent Ricatti Equations (SDRE) technique which uses sub-optimal control and system local stability search. Numerical simulations and experimental results are presented which demonstrate the effectiveness of the proposed control strategy.
Microwave Ignition for the Pulse Detonation Engine
Authors: Singh Gurjap
Published: March 2015

The Pulse Detonation Engine (PDE) is now offering the Aviation Industry a new, efficient and cheap mode of propulsion. Outside of the valving of the fuel and the air, the basic design of the PDE contains no moving parts: it is merely a tube in which some fuel is detonated, and the resultant shock wave used for propulsion. It suffers, however, from the lack of an appropriate ignition system designed especially for this propulsion technique. This paper discusses the possibility of using microwave radiation to initiate detonation in the PDE. Background information regarding the PDE, the merits of detonation over deflagration, and extant techniques for initiating detonation is included. The merits of this technique over the more traditional methods are emphasized. A practical technique of producing and controlling microwave radiation is subsequently presented. To prove viability of the central idea, a list of public patents related to the previous work done regarding the use of microwave radiation to initiate ignition is presented, along with a short summary related to each entry. This area of research is still new and unorthodox, as far as both the PDE and microwave ignition are concerned, and no work has been done until now that involves both of these. Further experiments involving realistic fuels and conditions to demonstrate the viability and practical use of this technique are required. It is expected that this research will do for the PDE what invention of spark plugs did for the gasoline (or Spark Ignition) engine.
An Investigation on the Relationship Between Operator’s Skill Level and Dimension Stability in Gel Coating
Authors: Kikuchi Tetsuo , Suzuki Erika , Liu Xiahui , Takai Yuka , Goto Akihiko , Hamada Hiroyuki , Yang Yuqiu
Published: March 2015

Gel Coating has been used for forming composite structures since ancient times. Although the gel coating method is very primitive, it offers the advantage of being able to deal widely with different production volumes and product sizes because the molds used are inexpensive and facility costs are low. On the other hand, gel coating work itself relies on human skills, which means that the finish differs according to the operator carrying out the work, the quality of the product differs among parts depending on the ease of forming. Hence highly specialized control technique and the tradition of skill are required to ensure the consistent stability of product quality. Generally, it needs more than 25 years of training and practice, as well as relentless efforts and an instinctive sense of molding to master the art of gel coating. However, there are in fact very few people who can be called experts of the technique in Japan. For this reason, the tradition of molding techniques needs to be carried on as quickly as possible.

It is considered that the experiment, seemingly a new and only attempt in Japan, quantified techniques that are not visibly apparent and considered to be tacit knowledge. Therefore, in this study, motion analysis experiment of gel coating experts by MAC 3D System at a sampling rate of 60 Hz was conducted to obtain objective data on an expert applier’s skills (the default value) with compared to the non-expert one. Furthermore, dimensional stability measurements were made, and an investigation of the correlation to an expert’s application techniques was conducted in order to pass the suitable training and communicating technical skills to advanced management engineering and inexperienced appliers.

It is found that the movement of an expert applier’s lower body had a different motion compared with a non-expert applier. The expert’s centroid moved smoothly and his motion tended to be constant. On the other hand, the non-expert’s motion was awkward at several points and his motion didn’t have the same tendencies as the expert.
Modeling and Control of the Electrical Actuation System of an Active Hydromagnetic Journal Bearing (AHJB)
Authors: Farmakopoulos Michael G. , Loghis Eleftherios K. , Nikolakopoulos Pantelis G. , Xiros Nikolaos I. , Papadopoulos Chris A.
Published: March 2015

The architecture of the electrical actuation module driving a magnetic-hydraulic bearing system is presented. The bearing is intended to be scaled for use in applications of all sizes in industries like shipboard for support of the engine-propeller shaft or in power-plants for the shaft through which the prime mover, e.g. steam or gas turbine, is driving the electric generator. The benefits of this new bearing is first and foremost its superb performance in terms of low down to practically no friction losses since there is no direct contact between the supporting bearing surface and the rotating shaft supported. Other benefits include the potential of active, inline, real-time balancing and alignment. To implement such concept of a magnetic-hydraulic bearing, the following tasks need to be carried out. First, identification of mechanical, electrodynamical and circuit properties of the bearing’s electromagnets in the system is necessary. Toward such identification, a series of experiments needed to be carried out. To be able to carry out these experiments, a specific power electronic converter is developed to drive each electromagnet. The power electronic drive is a quad MOSFET circuit based on full-bridge converter topology and outfitted with appropriate sensory instrumentation to collect and record measurements of all the physical variables of interest. Special care has been taken to compensate for magnetic hysteresis of the electromagnets, mitigate any induction heating effects and maintain operation within the material’s linear region i.e. without significant saturation occurring. The use of a power transistor bridge allows rapid changes to be applied on the electromagnet’s load force which could compensate disturbance or misalignment developed on the shaft supported. The data series from these experiments are useful for formulating a possibly nonlinear model of the electromagnetical and electromechanical processes involved in the bearing’s operation. Such a model can then be employed to help design a digital microcontroller system which could effectively drive the power electronics and electromagnets to perform their required tasks as part of the bearing. Besides, the model could also be used for the synthesis of the nonlinear, sampled-data (discrete-time) control law which will be programmed on the microcontroller system board.
A Novel Method to Model the Dynamics of an Uniball Robot
Authors: Chembrammel Pramod , Kesavadas Thenkurussi
Published: March 2015

In this paper the kinematics and dynamics of a uniball robot is demonstrated. The motion of a uniball robot is derived from the dynamics of a sphere rolling on a surface which is considered as a motion about a fixed point. The equations of motion are derived using Newton-Euler method incorporating the geometrical features of the surface. A uniball-robot can be considered as a Routh’s sphere whose center of mass is not at the geometrical center and have equal principal moments of inertia in the plane perpendicular to the axis connecting the center of mass and the geometrical center. The Euler angles are obtained using the Meusnier’s theorem which deals with the evolution of the surface as the robot moves along.
Bearing Fault Parameter Identification Under Varying Operating Conditions Using Vibration Signals and Evolutionary Algorithms
Authors: Abu-Mahfouz Issam , Banerjee Amit
Published: March 2015

This paper presents an effective bearing fault parameter identification scheme based on evolutionary optimization techniques. Three seeded faults in the rotating machinery supported by the test roller bearing include inner race fault, outer race fault and a single ball defect. The fault related features are extracted experimentally by processing the acquired vibration signals in both the time and frequency domain. Techniques based on the power spectral density (PSD) and wavelet transform (WT) are utilized for feature extraction. The sensitivity of the proposed method is investigated under varying operating speeds and radial bearing load. In this study, the inverse problem of parameter identification is investigated. The problem of parameter identification is recast as an optimization problem and two well known evolutionary algorithms, differential evolution (DE) and particle swarm optimization (PSO), are used to identify system parameters given a system response. For online parameter identification, differential evolution outperforms particle both in terms of adaptability and tighter convergence properties. The distinction between the two methods is not distinctively obvious on the offline parameter identification problem.
Evaluation Technique of Viscoelasticity of Pulsatile Tube Imitating Artery
Authors: Nakagawa Hiroya , Sakuma Atsushi , Simpo Takaya , Sakai Kazuhiko
Published: March 2015

The purpose of this study is to disclose the mechanism about arterial behavior for the development of the in situ diagnosis of human artery. Then, a method which can evaluate the viscoelasticity of artery is proposed for this purpose. In this evaluation, three-element solid model is adopted as a constitutive model of arterial tissue. A cylindrical tube of silicone rubber which imitates human artery is used in the validation of the proposed method. Here, the specimen is inserted to an artificial system of circulatory organ. The material parameters of this model are identified from the pulsatile behavior of the tube cylinder. The evaluation method is validated to derive the parameters at the same time by using the applied pulsatile pressure and deformation and the method of least-square. In the validated results, it is shown that the method can evaluate in more detail about the mechanical evaluation of the pulsatile tube imitating artery.
Stability Determination in Turning Using Persistent Homology and Time Series Analysis
Authors: Khasawneh Firas A. , Munch Elizabeth
Published: March 2015

This paper describes a new approach for ascertaining the stability of autonomous stochastic delay equations in their parameter space by examining their time series using topological data analysis. We use a nonlinear model that describes the tool oscillations due to self-excited vibrations in turning. The time series is generated using Euler-Maruyama method and then is turned into a point cloud in a high dimensional Euclidean space using the delay embedding. The point cloud can then be analyzed using persistent homology. Specifically, in the deterministic case, the system has a stable fixed point while the loss of stability is associated with Hopf bifurcation whereby a limit cycle branches from the fixed point. Since periodicity in the signal translates into circularity in the point cloud, the persistence diagram associated to the periodic time series will have a high persistence point. This can be used to determine a threshold criteria that can automatically classify the system behavior based on its time series. The results of this study show that the described approach can be used for analyzing datasets of delay dynamical systems generated both from numerical simulation and experimental data.
Electrically stable nanocomposite thin films formed by oxidation of Pt-ZrB2 nanolaminate templates
Authors: Sell Julia C. , Stewart David M. , Bernhardt George P. , Frankel David J. , Lad Robert J.
Published: March 2015

Platinum films of thickness <100 nm undergo agglomeration at temperatures exceeding 700 °C and lose electrically conductive pathways, making them unsuitable as stable films in high temperature electronic devices. To prevent agglomeration and create films that remain conductive above 1000 °C, a series of nanolaminate Pt-ZrB2 films comprised of Pt and ZrB2 were deposited to a total thickness of 200 nm at ambient temperature onto sapphire substrates using e-beam coevaporation. Annealing the nanolaminate films above 700 °C in air causes the ZrB2 and Pt layers to intermix, resulting in a nanocomposite Pt-ZrB2 film architecture. At temperatures between 1000 and 1300 °C in air, both monoclinic and tetragonal ZrO2 nanocrystallites are formed as indicated by x-ray diffraction, and they serve to hinder agglomeration of the Pt phase and allow for a stable network of conductive Pt-rich grains. Film electrical conductivity measurements acquired with a four-point probe indicate that the Pt-ZrB2 nanocomposite films retain conductivities in the 105–106 S/m range from 1000 to 1300 °C, and that the overall conductivity and stability depends on the Pt-ZrB2 layer thickness ratio. A nanolaminate film comprised of five 30 nm Pt/10 nm ZrB2 bilayers remained conductive after 1 h at 1300 °C. The use of a 100 nm thick amorphous Al2O3 protective capping layer grown by atomic layer deposition helps to limit oxygen diffusion into the Pt-ZrB2 films, but the films show regions of cracking and delamination of the Al2O3 layer due to stress caused by thermal expansion mismatch.
Computer‐aided detection of breast cancers using Haar‐like features in automated 3D breast ultrasound
Authors: Tan Tao , Mordang Jan‐Jurre , van Zelst Jan , Grivegnée André , Gubern‐Mérida Albert , Melendez Jaime , Mann Ritse M. , Zhang Wei , Platel Bram , Karssemeijer Nico
Published: March 2015

Purpose:

Automated 3D breast ultrasound (ABUS) has gained interest in breast imaging. Especially for screening women with dense breasts, ABUS appears to be beneficial. However, since the amount of data generated is large, the risk of oversight errors is substantial. Computer aided detection (CADe) may be used as a second reader to prevent oversight errors. When CADe is used in this fashion, it is essential that small cancers are detected, while the number of false positive findings should remain acceptable. In this work, the authors improve their previously developed CADe system in the initial candidate detection stage.

Methods:

The authors use a large number of 2D Haar‐like features to differentiate lesion structures from false positives. Using a cascade of GentleBoost classifiers that combines these features, a likelihood score, highly specific for small cancers, can be efficiently computed. The likelihood scores are added to the previously developed voxel features to improve detection.

Results:

The method was tested in a dataset of 414 ABUS volumes with 211 cancers. Cancers had a mean size of 14.72 mm. Free‐response receiver operating characteristic analysis was performed to evaluate the performance of the algorithm with and without using the aforementioned Haar‐like feature likelihood scores. After the initial detection stage, the number of missed cancer was reduced by 18.8% after adding Haar‐like feature likelihood scores.

Conclusions:

The proposed technique significantly improves our previously developed CADe system in the initial candidate detection stage.
A Mixed Methods Analysis of a Single-Course Strategy to Integrate Technology Into PETE
Authors: Wyant James D. , Jones Emily M. , Bulger Sean M.
Published: March 2015

In recent years increased attention has been placed on physical education teachers’ use of technology. To date little research has been disseminated regarding the strategies physical education teacher education (PETE) programs are employing to prepare preservice teacher’s to use technology. The purpose of this study was to examine the influence a technology course had on advancing change in preservice teachers. A mixed methods process involving qualitative and quantitative data collection was employed. Participants included 12 preservice teachers enrolled at a mid-Atlantic university. Data analysis revealed four dominant themes emerged from participant data: (1) Increased Technological and Technological Pedagogical Knowledge; (2) Persistent First- and Second-Order Barriers to Technology Use; (3) Necessity of Experiential and Hands-on Learning; and (4) Variation in Warrant for Technology Use. Findings illustrate strengths and limitations of a technology course in a preservice PETE program as well as its potential benefits and impediments to manifesting teacher change.
California fogs are thinning
Authors: Carswell Cally
Published: March 2015

Warming linked to urbanization prevents low clouds from forming, Los Angeles area study shows.
Coulomb crystallization of highly charged ions
Authors: Schmöger L. , Versolato O. O. , Schwarz M. , Kohnen M. , Windberger A. , Piest B. , Feuchtenbeiner S. , Pedregosa-Gutierrez J. , Leopold T. , Micke P. , Hansen A. K. , Baumann T. M. , Drewsen M. , Ullrich J. , Schmidt P. O. , López-Urrutia J. R. Crespo
Published: March 2015

Highly charged ions in cold confines

High-energy irradiation can strip many electrons away from individual atoms, producing ions with charges of +10 or more. However, many of the interesting properties of such highly charged ions are hard to study or exploit under the extreme conditions needed to prepare them. Schmöger
et al.
cooled down argon ions with +13 charges from the megakelvin temperatures needed for their generation to millikelvin temperatures appropriate for high-precision spectroscopy. The method relies on sympathetic cooling by a cold sample of singly charged beryllium ions and is likely to be applicable to a broad range of other elements.

Science
, this issue p.
1233
Pick your poison
Banned: A History of Pesticides and the Science of Toxicology
Frederick Rowe Davis
Yale University Press, 2014. 284 pp.
Authors: Hamblin Jacob Darwin
Published: March 2015

How getting rid of DDT opened the door for more dangerous pesticides
Reduced vaccination and the risk of measles and other childhood infections post-Ebola
Authors: Takahashi Saki , Metcalf C. Jessica E. , Ferrari Matthew J. , Moss William J. , Truelove Shaun A. , Tatem Andrew J. , Grenfell Bryan T. , Lessler Justin
Published: March 2015

Vaccinate children despite Ebola

During the medical emergency caused by the Ebola virus outbreak in West Africa, routine childhood vaccination programs have been suspended. If vaccination is not resumed soon, there could be even more deaths. Measles is highly infectious, and outbreaks are a sign of health care systems in trouble. Using mathematical modelling, Takahashi
et al.
estimate that about a million children across Liberia, Sierra Leone, and Guinea are vulnerable to measles. Aggressive public health programs are vital for this region to minimize harm, not only from measles but also from polio, malaria, tuberculosis, and other childhood infections.

Science
, this issue p.
1240
Control of mammalian G protein signaling by N-terminal acetylation and the N-end rule pathway
Authors: Park Sang-Eun , Kim Jeong-Mok , Seok Ok-Hee , Cho Hanna , Wadas Brandon , Kim Seon-Young , Varshavsky Alexander , Hwang Cheol-Sang
Published: March 2015

The N-end rule finds a physiological function

The N-end–rule pathway for protein degradation is a canonical degradation pathway discovered in the 1980s. In recent years, studies have focused on finding novel variant pathways of N-end recognition. The “classical” pathway is blocked by N-terminal acetylation of the substrate. However, in yeast, N-terminal acetylation need not block degradation, because a second pathway can act on acetylated N-termini. But is this alternate pathway a major player in the physiology of mammals? Park
et al.
now confirm the existence of the alternate pathway in mammalian cells. Most notably, patient-derived point mutations thought to confer hypertension in humans affect susceptibility to this pathway for the encoded protein substrate, Rgs2.

Science
, this issue p.
1249
Catalysis by nickel in its high oxidation state
Authors: Riordan Charles G.
Published: March 2015

A Ni
IV
catalyst couples carbon atoms to oxygen, sulfur, and nitrogen atoms

[Also see Report by
Camasso and Sanford
]
Genome Sequence of Corynebacterium ulcerans Strain FRC11
Authors: Benevides Leandro de Jesus , Viana Marcus Vinicius Canário , Mariano Diego César Batista , Rocha Flávia de Souza , Bagano Priscilla Carolinne , Folador Edson Luiz , Pereira Felipe Luiz , Dorella Fernanda Alves , Leal Carlos Augusto Gomes , Carvalho Alex Fiorini , Soares Siomar de Castro , Carneiro Adriana , Ramos Rommel , Badell-Ocando Edgar , Guiso Nicole , Silva Artur , Figueiredo Henrique , Azevedo Vasco , Guimarães Luis Carlos
Published: March 2015

Here, we present the genome sequence of
Corynebacterium ulcerans
strain FRC11. The genome includes one circular chromosome of 2,442,826 bp (53.35% G+C content), and 2,210 genes were predicted, 2,146 of which are putative protein-coding genes, with 12 rRNAs and 51 tRNAs; 1 pseudogene was also identified.
Candida inconspicua and Candida norvegensis: New Insights into Identification in Relation to Sexual Reproduction and Genome Organization
Authors: Guitard J. , Atanasova R. , Brossas J. Y. , Meyer I. , Gits M. , Marinach C. , Vellaissamy S. , Angoulvant A. , Mazier D. , Hennequin C.
Published: March 2015

Candida inconspicua
and
Candida
(
Pichia
)
norvegensis
are two emerging pathogenic species that exhibit reduced susceptibility to azole derivatives. Conventional (biochemical) approaches do not readily differentiate between the two species. The first aim of this work was to analyze the performance of biochemical, proteomic (matrix-assisted laser desorption ionization–time of flight [MALDI-TOF]), and molecular approaches in the precise identification of these species. These results then led us to sequence 3 genomic loci, i.e., the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA), the D1/D2 domain of the 28S rDNA, and the elongation factor 1α (EF-1α) gene, either directly or following cloning, of 13 clinical isolates and 9 reference strains belonging to the 5 species included in the
Pichia cactophila
clade, namely,
Pichia cactophila
,
Pichia insulana
,
C. inconspicua
,
C. norvegensis
, and
P. pseudocactophila
. Finally, isolates of
C. inconspicua
were challenged for sexual reproduction on the appropriate medium. Our results show that EF-1α sequencing and proteic profiling by MALDI-TOF are the two most efficient approaches to distinguish between
C. norvegensis
and
C. inconspicua
. As a characteristic of the
P. cactophila
clade, we found multiple alleles of the rDNA regions in certain strains belonging to the tested species, making ITS or D1/D2 sequencing not appropriate for identification. Whatever the method of identification, including MALDI-TOF and EF-1α sequencing, none could differentiate
C. inconspicua
from
P. cactophila
. The results of phylogenetic analysis and the generation of asci from pure cultures of all
C. inconspicua
strains both support the identification of
P. cactophila
as the teleomorph of
C. inconspicua
.