bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of U10Mo Fuel Plate Irradiation Behavior via Numerical and Experimental Benchmarking
Authors: Miller Samuel J. , Ozaltun Hakan
Published: October 2013

This article analyzes dimensional changes due to irradiation of monolithic plate-type nuclear fuel and compares results with finite element analysis of the plates during fabrication and irradiation. Monolithic fuel plates tested in the Advanced Test Reactor (ATR) at Idaho National Lab (INL) are being used to benchmark the performance of proposed fuel for several high power research reactors. Post-irradiation metallographic images of plates sectioned at the mid-plane were analyzed to determine dimensional changes of the fuel and the cladding response. A constitutive model of the fabrication process and irradiation behavior of the tested plates was developed using the general purpose commercial finite element analysis package, ABAQUS. Using calculated burn-up profiles of irradiated plates to model the power distribution and including irradiation behaviors such as swelling and irradiation enhanced creep, model simulations allow analysis of plate parameters that are either impossible or infeasible in an experimental setting. The development and progression of fabrication induced stress concentrations at the plate edges was of primary interest, as these locations have a unique stress profile during irradiation. Additionally, comparison between 2D and 3D models was performed to optimize analysis methodology. In particular, the ability of 2D and 3D models to account for out of plane stresses which result in 3-dimensional creep behavior that is a product of these components. Results show that assumptions made in 2D models for the out-of-plane stresses and strains cannot capture the 3-dimensional physics accurately and thus 2D approximations are not representative. Stress-strain fields are dependent on plate geometry and irradiation conditions, thus, if stress based criteria is used to predict plate behavior (as opposed to material impurities, fine micro-structural defects, or sharp power gradients), unique 3D finite element formulation for each plate is required.
Second Law Analysis for a Mixed Electro-Osmotic and Pressure Driven Flow of a Viscoelastic Fluid in a Micro-Channel
Authors: Escandón Juan P. , Fernández Juan G. , Bautista Oscar E. , Méndez Federico
Published: October 2013

In this work the entropy generation rate in a parallel flat plate micro-channel under mixed electro-osmotic and pressure driven flow with a non-Newtonian fluid is analyzed. A fully-developed flow is considered and the fluid obeys a constitutive relation based in a simplified Phan-Thien-Tanner model. The temperature distributions of a conjugate heat transfer problem in the micro-channel were solved asymptotically in steady-state, then, expressions for dimensionless local and average entropy generation rate are obtained. The aim of this paper is to show the influence of dimensionless parameters involved on the entropy generation rate: the viscoelastic parameter, the ratio of pressure forces to electro-osmotic forces, the Péclet number, the normalized power generation term, the dimensionless temperature difference, the ratio of micro-channel thickness to length, the ratio of micro-channel wall thickness to length and the conjugation parameter; this set of parameters controls directly the thermal performance of this micro-channel. We can predict that the entropy generation rate is basically dominated by the Joule heating effect.
Toward an Early-Phase Conceptual System Design Risk-Informed Decision Making Framework
Authors: Van Bossuyt Douglas , Hoyle Chris , Tumer Irem Y. , Malak Richard , Doolen Toni , Dong Andy
Published: October 2013

Current methods of risk analysis conducted during the early phases of complex system design do not give a clear voice to the customer or design engineer when considering engineering risk attitude in the dynamic shaping of early-phase conceptual design trade study outcomes. The existing methods either collect risk information following the completion of a conceptual design thus treating risk as an afterthought during trade studies, make risk-informed decisions prior to the conduction of trade studies thus artificially constraining the design space, or do not consider risk at all. This paper proposes a risk-informed decision making framework that offers a new, meaningful way of accounting for risk during trade studies, informs design decisions during trade studies with pertinent risk information, and takes into account risk attitude of the design engineer or customer when risk-informed decisions are made. Risk is elevated to the same level of importance as other system level variables in trade studies and risk-based decisions are made by individual subsystem engineers through the lens of risk appetite. Several previously developed methods of risk trading, assessing engineering risk attitude, and making risk-informed decisions based upon engineering risk attitude using utility theory are synthesized into the risk-informed decision-making framework. Implementation methods for trade studies being performed by groups of people and automatically by computers are presented. Sensitivity of the framework to input variable variation is examined. A spacecraft example is employed to demonstrate the usefulness of the framework. This paper provides a novel framework for risk-informed design decisions made within trade studies that are based upon engineering risk attitudes in early phase conceptual design.
Applying Designer Feedback to Generate Requirements for an Intuitive Biologically Inspired Design Tool
Authors: Arlitt Ryan , O’Halloran Bryan M. , Novak Jennifer , Stone Robert B. , Tumer Irem Y.
Published: October 2013

This research provides a comparison of a set of Bio-Inspired Design (BID) tools to determine advantages and disadvantages of each, with particular focus on database-directed design processes. The result of this comparison is a set of beneficial attributes, discussed to develop requirements for formulating an effective BID tool. In this study, each tool is evaluated in terms of both the effectiveness of the concept generation process, and designer feedback concerning the effective elements. The comparison between tools uses concept sketches and feedback generated from a classroom of graduate and undergraduate engineering students. Over the course of a ten-week class, each BID technique was formally presented to the students. Following this presentation, students were given a new design problem and instructed to use the new BID technique to generate a set of solution concepts. Quantity of concepts generated was used to assess the goodness of each concept generation activity outcome, which forms one basis for comparing the different tools. In addition, questionnaires were used to assess and identify the various positive and negative elements of each BID tool.
A Survey of Early Design Risk and Reliability Methods and Their Impediments to Move Into Practice
Authors: O’Halloran Bryan M. , Stone Robert B. , Tumer Irem Y.
Published: October 2013

This research surveys early design risk and reliability methodologies and discusses the impediments of moving these research methods into practice. Reliability engineering techniques exist primarily to help engineers better meet the needs of customers by extending design life and reducing the number of failures observed throughout the intended life. These efforts look at system components and functions, critical events, failure modes, and system characteristics to assess risk and reliability during the early design phase before detailed design has begun. Surveying early design reliability to identify underdeveloped areas of research contributes to an ongoing effort to increase the presence of reliability engineering earlier in design. In addition, this improves a researchers’ understanding of key consideration that need to be addressed during the development of the research so that it is useful in practice. Throughout this paper, four fundamental methods are identified and described including Event Tree Analysis, Fault Tree Analysis, Reliability Block Diagrams, and Failure Modes and Effects Analysis. Related methods, or those developed to solve limitations of the fundamental methods, are presented and compared to the fundamental methods. Finally, the impediments of moving research methods into practice are surveyed, then discussion is provided for the factors that improve this transition of research.
Modeling the Hotspot Temperature in AlGaN/GaN High Electron Mobility Transistors Using a Non-Gray Phonon BTE Solver
Authors: Donmezer Fatma Nazli , Islam Munmun , Graham Samuel , Yoder Douglas
Published: October 2013

In this work, we utilize electron-phonon Monte Carlo simulations of AlGaN/GaN HEMTs to determine the energy loss rate of electrons in the channel of the transistor as a function of bias conditions. Intense energy transfer from electrons to phonons is observed near the gate edge on the drain side of such devices where the peak electric field exists. This intense energy exchange results in nanometer sized hotspots in the vicinity of the gate edge. In order to account for effects of ballistic phonon transport on temperature near the hotspots, a non-gray Discrete Ordinates Method (DOM) is used as a numerical solver for the phonon Boltzmann Transport Equation (BTE). The non-gray model accounts for dispersion effects of GaN by splitting the dispersion curve of GaN into a finite number of frequency bands. The phonons in each frequency band are assumed to have the same properties with the other phonons in the same band and the relaxation times between these bands are calculated. The results show how energy is redistributed among the available phonon bands and demonstrates which modes are most effective at transporting the thermal energy. Finally, the hotspot temperature predictions obtained by the model are compared to temperatures obtained by gray and continuum modeling approaches to show the discrepancies between different techniques.
Development of a System for the Study of Solid Fuel Conversion Under Supercritical Water Conditions
Authors: Kim Bumjick , Mitchell Reginald E.
Published: October 2013

Due to its low cost and abundance, a large amount of coal and biomass is still being used to generate electricity throughout the world. Given that these solid fuels are here to stay for the foreseeable future, the problem of their environmental impact in terms of their emission of CO2 and harmful gas streams will remain unless solutions to it can be found. Supercritical water (SCW) is an attractive medium for power generation because of its special characteristics. Organic compounds extracted from coal and biomass hydrolyze, and they are completely miscible in SCW. In contrast, sulfur, chlorine and many trace elements in coal are oxidized and form insoluble salts in SCW, which precipitate and can be removed. The coal/biomass-to-electricity scheme takes advantage of these characteristics of SCW in using it as a reaction medium.

A description of the experimental facility to conduct experiments for pulverized coal and biomass conversion under SCW conditions (P>218 atm and T>647 K) is provided. The facility includes high-pressure water pumps, pulse-dampening accumulators, a water preheater, an oxygen booster, a SCW gasification reactor, and a reaction quenching cooler. This work presents the entire coal/biomass conversion system, built and assembled, which permits the acquisition of data needed to determine the rate coefficients for reactions that are suitable for SCW conditions. The focus of the facility is a flow reactor that can be pressurized up to 340 atm at temperatures up to 750 K. The continuous flow reactor is 15 meters long, sufficient for residence times as long as 15 minutes when the total mass flow rate (slurry plus SCW flow rates) is 20 grams/min. The residence time in the reactor is varied by controlling the solids content of the slurry and the flow rate of the water supplied. The feed water is pressurized and preheated to the test conditions before the solids slurry and any oxygen are admitted. Oxygen is added so that the heat release from partial oxidation of the solids can supply energy for autothermal gasification. The facility developed is in operation to collect data sets for the characterization of conversion mechanism.
Mechanical Engineering TA Training Program Transformation
Authors: Bigio David I. , Bruck Hugh
Published: October 2013

A comprehensive training program for graduate students is presented in which the students are coached in being a Teaching Assistant (TA) and for performing research. A semester-long course ENME808Q – Professional Essentials was created as a vehicle to improve the effectiveness of the TAs in the classroom and to train them in long-term skills for their professional success.
Analytical Prediction of Melt Depth Inside Ti-6Al-4V During Laser Materials Processing
Authors: Ngwenya D. , Kahlen F. J.
Published: October 2013

The prediction of melt depth evolution inside Ti-6A-4V during laser-material processing enables the understanding of how heat affects the microstructure and phase transformations. However, modeling time increases with increased complication of mathematical functions. This work investigates the feasibility of approximating a melt depth profile which features the inverse of a complimentary error function (erfcinv) with a simpler mathematical function. It is proposed that for the ease of calculations, a melt depth profile containing the natural log function (ln) be used to approximate an erfcinv-bearing melt-depth-predicting equation. An introduction of a ratio R is made as a correction factor. This ratio is then applied to the natural-log-function-bearing melt-depth-predicting equation thus improving upon its approximation. In addition, the dependency of R on the affective laser parameters such as pulse duration and incident power density is investigated.
A Transferable Education Model for Creating Work-Ready College Graduates
Authors: Smith Lorenzo M. , Guessous Laila , Barber Gary C. , Cole Trevor , Keeler Stu
Published: October 2013

“Work-ready” college graduates, upon their first day at work, are able to make employee contributions which are comparable to those associated with a typical employee who is three years removed from his/her undergraduate graduation. The objective of CLIC-form (Chrysler Learning and Innovation Center for Sheet Metal Forming), a program recently implemented at Oakland University, is to deliver work-ready college graduates to the American sheet metal forming industry. Long-term fulfillment of this objective is expected to increase productivity and job satisfaction in the American work-force, enrich educational experiences for university students, and foster greater funded research opportunities for the university.

CLIC-form is a proven educational model. Now in its second year, it is recruiting a third cohort of Oakland University students, hosting once-per-week educational workshops for both students and local industry professionals, and continuing to generate revenue through direct support from Chrysler Group, LLC and funded research activity from other sources. Presented in this paper is a description of CLIC-form’s structure, operation and financial outlook. A proposed form for extending the CLIC-form template to different fields of study is offered.
Modeling of the Heave and the Cushion Pressure of Air Cushion Landing System (ACLS): Chaotic Dynamics Investigation
Authors: Sowayan Ahmed S.
Published: October 2013

A theoretical model for the dynamics behavior of an incompressible Air Cushion Landing System (ACLS) is introduced. In this model the incompressible Bernoulli’s equation and the Newton’s second law of motion are used to predict the dynamic behavior of the heave (vertical response) of the ACLS in both time and frequency domains. The mass flow rate inside the air cushion of this model is assumed to be constant. The self excited response for the heave and the cushion pressure of the ACLS are calculated. In this study, the dimensionless mass flow rate and the dimensionless skirt of the ACLS’s skirt are the only parameters which are considered to be investigated to control the steady state behavior of the oscillatory motion of the ACLS.

The equations of motion of the proposed nonlinear model are solved numerically using a code written on the Matlab software which is based on the Runge Kutta numerical integration method. The chaotic behavior of the heave motion and cushion pressure dynamics are investigated with the aid of the Fourier analysis and the Poincaré map. Periodic behavior is noticed in the vertical motion; on the other hand a chaotic behavior is manifest in the pressure inside the cushion volume of the ACLS. This model will help designers of the ACLS to understand the dynamics behavior of this system in order to redesign such system so that the violent oscillatory self excited motion can be reduced or eliminated.
Use of Satellite Images for Observational and Quantitative Analysis of Urban Heat Islands Around the World
Authors: Wong Kaufui V. , Chaudhry Sarmad
Published: October 2013

Urban Heat Island Intensity (UHII) is calculated as the spatially-averaged temperature difference between an urban and its surrounding rural area. This concept, however, provides an umbrella for a range of diversified ideas that include the temperature difference between the densely developed urban area and least developed area or between two different built-up areas. There are also averages for the season, for the year, for multiple years, etc. and UHII quoted for the day and another for the night.

The objective of this work is to examine the urban heat island effect for cities around the world, using readily available data. The innovation is in using data from the Landsat satellites for different cities previously not studied. Thermal images of the Earth were obtained and analyzed to produce surface temperature maps. These maps showed that the temperature in the urban environments were significantly higher than the temperature in the surrounding countryside, a defining characteristic of urban heat island.

Furthermore, the urban and rural areas in the images were separated and analyzed individually to quantitatively measure the temperature difference. It was found that the UHII could be 0.3–5.1°C for the eleven cities investigated. Miami and Shenzen are two cities which seem to have been missed in previous studies because they were limited in their scope and responsibilities, and their methods required much more resources for the longer term studies.

It is not the claim here that a UHI is definitively established by the analysis presented of the Landsat satellite data. The present work demonstrates the use of a possible planning tool in terms of understanding where urban areas may be subjected to additional heat. Our use of the method shows that a UHI is probably taking place at the time of observation, and precautionary notices should be sent out to the community to take preventative measures to ensure their health and wellbeing. The minimal resources required is the demonstration shown by our work of the usefulness of this method.
Optimization of Propulsion Kinematics of a Flexible Foil Using Integrated CFD-CSD Simulations
Authors: You Jiho , Lee Jinmo , You Donghyun
Published: October 2013

A computational simulation methodology, which combines a computational fluid dynamics technique and a computational structural dynamics technique, is employed to design a deformable foil of which kinematics is inspired by the propulsive motion of a fin or a tail of fish and cetacean. The unsteady incompressible Navier-Stokes equations are solved using a second-order accurate finite-difference method and an immersed-boundary method to effectively impose boundary conditions on complex moving boundaries. A finite-element-based structural dynamics solver is employed to compute the deformation of the foil due to interaction with fluid. A phase angle between pitching and heaving motions as well as the flexibility of the foil, which is represented by the Youngs modulus are varied to find out how these factors affect the propulsion efficiency.
Camshaft Efficiency Optimization: Employing the Rolling Bearing
Authors: Bayat Pour Mohsen
Published: October 2013

This paper is intended to discuss the optimization of camshaft efficiency; using the rolling bearing instead of the sliding bearing within the internal combustion engines. The advantages and disadvantages of employing this new method will be accordingly identified and determined in-order to open new windows to the vehicle manufacturing industry. Following the mentioned goal; a camshaft is designed and tested over two types of sliding and rolling bearings in the same conditions of testing. After the comparisons being made; the achieved records have been analyzed and finally the results have been concluded and discriminated by the tables. The calculations and analyses; which are reachable within this paper, are implemented by employing both simulation software and laboratory devices.
Radiofrequency pulsed glow discharge-ToFMS depth profiling of a CdTe solar cell: A comparative study versus time of flight secondary ion mass spectrometry
Authors: Gonzalez-Gago Cristina , Pisonero Jorge , Bordel Nerea , Sanz-Medel Alfredo , Tibbetts Nicole J. , Smentkowski Vincent S.
Published: October 2013

In this manuscript, the authors compare and contrast depth profile data generated on the same commercially available CdTe cell using two analytical techniques, Time of flight secondary ion mass spectroscopy (ToF-SIMS), which is a well-established technique, and radiofrequency pulsed glow discharge (rf-PGD)-ToFMS, which is an emerging technique. The authors demonstrate that pulsed-rf-GD-ToFMS allows for a rapid analysis over a large (4 mm diameter) area of the sample at moderate vacuum conditions, while ToF-SIMS analyzes smaller regions (typically about 200 × 200 μm2) of the sample at ultrahigh vacuum conditions; the authors note that ToF-SIMS enables three dimensional analysis at micron or better lateral resolution. Both techniques show, in general, good agreement; however, some discrepancies are observed and discussed herein.
Sputter-cleaned Epitaxial VxMo(1-x)Ny/MgO(001) Thin Films Analyzed by X-ray Photoelectron Spectroscopy: 3. Polycrystalline V0.49Mo0.51N1.02
Authors: Greczynski Grzegorz , Kindlund Hanna , Petrov Ivan , Greene Joe , Hultman Lars
Published: October 2013

VxMo(1-x)Ny thin films grown by ultrahigh vacuum reactive magnetron sputter deposition on MgO(001) substrates are analyzed by x-ray photoelectron spectroscopy (XPS). This contribution presents analytical results for 300-nm-thick 002-textured polycrystalline V0.49Mo0.51N1.02 films deposited by reactive cosputtering from V (99.95 % purity) and Mo (99.95 % purity) targets. Film growth is carried out at 500 °C in mixed Ar/N2 atmospheres at a total pressure of 5 mTorr, with a N2 partial pressure of 3.2 mTorr; a bias of −30 V is applied to the substrate. Films composition is determined by Rutherford backscattering spectrometry (RBS). XPS measurements employ monochromatic Al Kα radiation (hν = 1486.6 eV) to analyze V0.49Mo0.51N1.02 surface sputter-cleaned in-situ with 4 keV Ar+ ions incident at an angle of 70° with respect to the surface normal. XPS results show that the ion-etched sample surfaces have no measurable oxygen or carbon contamination; film composition, obtained using XPS sensitivity factors, is V0.34Mo0.66N1.00. All core level peaks, including the nearby Mo 3p3/2 (binding energy of 394.3 eV) and N 1s (at 397.4 eV) peaks, are well-resolved. Comparison to V0.33Mo0.67N0.64 and V0.34Mo0.66N0.81 single-crystal film surfaces, submitted separately to Surface Science Spectra, indicates that with decreasing growth temperature from 900 to 700 and 500 °C (and increasing nitrogen concentration in VxMo(1-x)Ny from y = 0.64 to 0.81 and 1.00) the N 1s core level peak shifts from 397.6 eV to 397.5 eV to 397.4 eV while metal atom peaks move towards higher binding energy by 0.2-0.4 eV.
The use of computed radiography plates to determine light and radiation field coincidence
Authors: Kerns James R. , Anand Aman
Published: October 2013

Purpose:

Photo‐stimulable phosphor computed radiography (CR) has characteristics that allow the output to be manipulated by both radiation and optical light. The authors have developed a method that uses these characteristics to carry out radiation field and light field coincidence quality assurance on linear accelerators.

Methods:

CR detectors from Kodak were used outside their cassettes to measure both radiation and light field edges from a Varian linear accelerator. The CR detector was first exposed to a radiation field and then to a slightly smaller light field. The light impinged on the detectorˈs latent image, removing to an extent the portion exposed to the light field. The detector was then digitally scanned. AMATLAB‐based algorithm was developed to automatically analyze the images and determine the edges of the light and radiation fields, the vector between the field centers, and the crosshair center. Radiographic film was also used as a control to confirm the radiation field size.

Results:

Analysis showed a high degree of repeatability with the proposed method. Results between the proposed method and radiographic film showed excellent agreement of the radiation field. The effect of varying monitor units and light exposure time was tested and found to be very small. Radiation and light field sizes were determined with an uncertainty of less than 1 mm, and light and crosshair centers were determined within 0.1 mm.

Conclusions:

A new method was developed to digitally determine the radiation and light field size using CR photo‐stimulable phosphor plates. The method is quick and reproducible, allowing for the streamlined and robust assessment of light and radiation field coincidence, with no observer interpretation needed.
Calculating Pi Using the Monte Carlo Method
Authors: Williamson Timothy
Published: October 2013

During the summer of 2012, I had the opportunity to participate in a research experience for teachers at the center for sustainable energy at Notre Dame University (RET @ cSEND) working with Professor John LoSecco on the problem of using antineutrino detection to accurately determine the fuel makeup and operating power of nuclear reactors. During full power operation, a reactor may produce 1021 antineutrinos per second with approximately 100 per day being detected. While becoming familiar with the design and operation of the detectors, and how total antineutrino flux could be obtained from such a small sample, I read about a simulation program called Monte Carlo.1 Further investigation led me to the Monte Carlo method page of Wikipedia2 where I saw an example of approximating pi using this simulation. Other examples where this method was applied were typically done with computer simulations2 or purely mathematical.3 It is my belief that this method may be easily related to the students by performing the simple activity of sprinkling rice on an arc drawn in a square. The activity that follows was inspired by those simulations and was used by my AP Physics class last year with very good results.
Developing Early Undergraduate Research at a Two-Year College
Authors: Sibbernsen Kendra
Published: October 2013

Two-year college (TYC) physics teachers are not often required to provide student research experiences as a part of their contracted duties. However, some TYC physics faculty members are interested in developing research opportunities for their freshman- and sophomore-level students, often called “early undergraduate research” (EUR). Here are some suggestions if you are interested in developing and managing EUR at your TYC.
Pharmacokinetics and RC Circuit Concepts
Authors: Cock Mieke De , Janssen Paul
Published: October 2013

Most introductory physics courses include a chapter on RC circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal1–5 describe lab experiments dealing with the measurement of different parameters in such RC circuits. In this contribution, we report on a lab experiment we developed for students majoring in pharmacy, using RC circuits to simulate a pharmacokinetic process.
The Pedagogical Value of “Obvious” Questions in Introductory Physics
Authors: Frank Brian , Goertzen Renee Michelle , Hutchison Paul
Published: October 2013

Each time students engage in a classroom activity, they make tacit interpretations (about the nature of those activities) that influence how they reason and ultimately what they learn. For example, a student answering a physics question on a worksheet might draw on her everyday thinking to help make sense of the physics, or she might not even consider everyday thinking if its usefulness was not readily apparent. For many physics instructors, the reconciliation of everyday thinking and formal physics knowledge is part of what it means to fully understand physics.1 Despite this, many students do not see reconciling these two things as what they are supposed to do in the classroom. Often we see students whose interpretation of physics class causes them to “turn off” their everyday thinking. In this article, we argue for the importance of attending closely to whether students are reconciling their everyday and formal physics thinking and introduce “obvious” questions as a tool that can help instructors assess whether such reconciliation is taking place.
Caprine Abscess Model of Tulathromycin Concentrations in Interstitial Fluid from Tissue Chambers Inoculated with Corynebacterium pseudotuberculosis following Subcutaneous or Intrachamber Administration
Authors: Washburn K. E. , Fajt V. R. , Lawhon S. D. , Adams L. G. , Tell L. A. , Bissett W. T.
Published: October 2013

Corynebacterium pseudotuberculosis
causes chronic, suppurative, abscessing conditions in livestock and humans. We used an
in vivo
model to evaluate antimicrobial efficacy for focal abscesses caused by
C. pseudotuberculosis
. Tissue chambers were surgically implanted in the subcutaneous tissues of the right and left paralumbar fossa of 12 goats to serve as a model for isolated, focal abscesses. For each goat, one tissue chamber was inoculated with
C. pseudotuberculosis
, while the contralateral chamber served as an uninoculated control. Six goats were administered a single dose of tulathromycin at 2.5 mg/kg of body weight subcutaneously, while the other six received the same dose by injection directly into the inoculated chambers. Our objective was to compare the effects and tulathromycin concentrations in interstitial fluid (IF) samples collected from
C. pseudotuberculosis
-infected and control chambers following subcutaneous or intrachamber injection of tulathromycin. In addition, the effects of tulathromycin on the quantity of
C. pseudotuberculosis
reisolated from inoculated chambers were assessed over time. Tulathromycin IF concentrations from
C. pseudotuberculosis
-infected and control tissue chambers were similar to those in plasma following subcutaneous administration. Following intrachamber administration, tulathromycin IF concentrations in infected chambers were continuously above the MIC for the
C. pseudotuberculosis
isolate for 15 days. There were no significant differences for plasma area under the curve and elimination half-lives between subcutaneous and intrachamber administration. Six of the 12 infected chambers had no growth of
C. pseudotuberculosis
15 days postadministration. Results of this study indicate that tulathromycin may be beneficial in the treatment of focal infections such as those caused by
C. pseudotuberculosis
.
CD4
+
T Cells Drive Goblet Cell Depletion during Citrobacter rodentium Infection
Authors: Chan Justin M. , Bhinder Ganive , Sham Ho Pan , Ryz Natasha , Huang Tina , Bergstrom Kirk S. , Vallance Bruce A.
Published: October 2013

Both idiopathic and infectious forms of colitis disrupt normal intestinal epithelial cell (IEC) proliferation and differentiation, although the mechanisms involved remain unclear. Recently, we demonstrated that infection by the attaching and effacing murine pathogen
Citrobacter rodentium
leads to a significant reduction in colonic goblet cell numbers (goblet cell depletion). This pathology depends on T and/or B cells, as
Rag1
−/−
mice do not suffer this depletion during infection, instead suffering high mortality rates. To address the immune mechanisms involved, we reconstituted
Rag
−/−
mice with either CD4
+
or CD8
+
T cells. Both T cell subsets increased
Rag1
−/−
mouse survival during infection, with mice that received CD8
+
T cells developing colonic ulcers but not goblet cell depletion. In contrast, mice that received CD4
+
T cells showed goblet cell depletion in concert with exaggerated IEC proliferation. To define the possible involvement of T cell-derived cytokines, we infected gamma interferon receptor gene knockout (
IFN-γR
−/−
) mice and wild-type mice given interleukin 17A (IL-17A) neutralizing antibodies and found that IFN-γ signaling was required for both goblet cell depletion and increased IEC proliferation. Immunostaining revealed that
C. rodentium
cells preferentially localized to nonhyperplastic crypts containing numerous goblet cells, whereas hyperplastic, goblet cell-depleted crypts appeared protected from infection. To address whether goblet cell depletion benefits the
C. rodentium
-infected host, we increased goblet cell numbers using the γ-secretase inhibitor dibenzazepine (DBZ), which resulted in greatly increased pathogen burdens and mortality rates. These results demonstrate that goblet cell depletion reflects host immunomodulation of IEC homeostasis and reflects a novel host defense mechanism against mucosal-adherent pathogens.
Lingual neurofibroma causing dysaesthesia of the tongue
Authors: Lykke Eva , Noergaard Tove , Rasmussen Eva Rye
Published: October 2013

Neurofibroma is a benign tumour derived from the neural sheaths of peripheral nerves and composed of Schwann cells, fibroblast-like cells and intermediate cells. The usual clinical presentation of an oral neurofibroma is swelling. A 62-year-old woman was referred to our department of otorhinolaryngology with irritation and dysaesthesia of the lateral aspect of the tongue. The only finding was a slightly red area from which a biopsy was taken. The macroscopic findings observed by the surgeon were consistent with normal tongue tissue. The histopathological examination showed a small, rounded tumour closely approximated to an invagination of the surface epithelium and with a small lymphatic infiltrate. The tumour was a neurofibroma. A Schwannoma type B was considered but the presence of small nerves and positive neurofilament reaction favoured a neurofibroma. The patient had no other neurofibromas or skin lesions. At a 3-week follow-up visit all symptoms had resolved.
Epidemiology, management and outcome of paracetamol poisoning in an inner city emergency department
Authors: Carroll R , Benger J , Bramley K , Williams S , Griffin L , Potokar J , Gunnell D
Published: October 2013

Background

Paracetamol poisoning accounts for just under half of all self-poisoning cases that present to hospitals in England. Treatment with acetylcysteine is routine, yet recommendations regarding its use vary internationally and have recently been revised in England and Wales.

Methods

Data on all cases of paracetamol poisoning presenting to an adult inner city emergency department between May 2011 and April 2012 were prospectively collected using the Bristol Self-harm Surveillance Register.

Results

Paracetamol overdoses accounted for 44% of adult self-poisoning cases. A quarter (26.9%) of patients required treatment with acetylcysteine and it was estimated that recent changes in treatment guidelines would increase that proportion to 32.6%. Paracetamol concentration was positively associated with the risk of any adverse reaction to acetylcysteine. 22.5% of patients experienced anaphylactoid reactions to acetylcysteine. There was no clear evidence of an association between risk of anaphylactoid reaction and blood paracetamol levels. Patients presenting with blood paracetamol levels greater than 200 mg/L at 4 h post-ingestion were at greater risk of repeat self-harm (HR 2.17, 95% CI 1.11 to 4.21, p=0.033).

Discussion

The recent changes in UK treatment guidelines are expected to increase the proportion of our population requiring acetylcysteine by 5.7%. We found no clear evidence that risk of anaphylactoid or more general adverse reaction to acetylcysteine was increased in patients presenting with lower blood paracetamol concentrations. Blood paracetamol level was highlighted as a potentially useful clinical indicator for risk of repeat self-harm.
The association between prehospital care and in-hospital treatment decisions in acute stroke: a cohort study
Authors: Sheppard James P , Mellor Ruth M , Greenfield Sheila , Mant Jonathan , Quinn Tom , Sandler David , Sims Don , Singh Satinder , Ward Matthew , McManus Richard J
Published: October 2013

Background

Hospital prealerting in acute stroke improves the timeliness of subsequent treatment, but little is known about the impact of prehospital assessments on in-hospital care.

Objective

Examine the association between prehospital assessments and notification by emergency medical service staff on the subsequent acute stroke care pathway.

Methods

This was a cohort study of linked patient medical records. Consenting patients with a diagnosis of stroke were recruited from two urban hospitals. Data from patient medical records were extracted and entered into a Cox regression analysis to investigate the association between time to CT request and recording of onset time, stroke recognition (using the Face Arm Speech Test (FAST)) and sending of a prealert message.

Results

151 patients (aged 71±15 years) travelled to hospital via ambulance and were eligible for this analysis. Time of symptom onset was recorded in 61 (40%) cases, the FAST test was positive in 114 (75%) and a prealert message was sent in 65 (44%). Following adjustment for confounding, patients who had time of onset recorded (HR 0.73, 95% CI 0.52 to 1.03), were FAST-positive (HR 0.54, 95% CI 0.37 to 0.80) or were prealerted (HR 0.26, 95% CI 0.18 to 0.38), were more likely to receive a timely CT request in hospital.

Conclusions

This study highlights the importance of hospital prealerting, accurate stroke recognition, and recording of onset time. Those not recognised with stroke in a prehospital setting appear to be excluded from the possibility of rapid treatment in hospital, even before they have been seen by a specialist.
The impact of thunderstorm asthma on emergency department attendances across London during July 2013
Authors: Elliot A J , Hughes H E , Hughes T C , Locker T E , Brown R , Sarran C , Clewlow Y , Murray V , Bone A , Catchpole M , McCloskey B , Smith G E
Published: October 2013

Background

This study illustrates the potential of using emergency department attendance data, routinely accessed as part of a national syndromic surveillance system, to monitor the impact of thunderstorm asthma.

Methods

The Emergency Department Syndromic Surveillance System (EDSSS) routinely monitors anonymised attendance data on a daily basis across a sentinel network of 35 emergency departments. Attendance data for asthma, wheeze and difficulty breathing are analysed on a daily basis.

Results

A statistically significant spike in asthma attendances in two EDSSS emergency departments in London was detected on 23 July 2013, coinciding with a series of large violent thunderstorms across southern England. There was also an increase in the reported severity of these attendances.

Conclusions

This preliminary report illustrates the potential of the EDSSS to monitor the impact of thunderstorms on emergency department asthma attendances. Further work will focus on how this system can be used to quantify the impact on emergency departments, thus potentially improving resource planning and also adding to the thunderstorm asthma evidence-base.
Socioeconomic and behavioural risk factors for adverse winter health and social outcomes in economically developed countries: a systematic review of quantitative observational studies
Authors: Tanner Louise M , Moffatt Suzanne , Milne Eugene M G , Mills Susanna D H , White Martin
Published: October 2013

Background

Mortality and morbidity rates are often highest during the winter period, particularly in countries with milder climates. A growing body of research has identified potential socioeconomic, housing and behavioural mediators of cold weather-related adverse health and social outcomes, but an inclusive systematic review of this literature has yet to be performed.

Methods

A systematic review, with narrative synthesis, of observational research published in English between 2001 and 2011, which quantified associations between socioeconomic, housing or behavioural factors and cold weather-related adverse health or social outcomes.

Results

Thirty-three studies met the inclusion criteria. Average study quality was not high. Most studies failed to control for all relevant confounding factors, or to conduct research over a long enough period to ascertain causality. Low income, housing conditions and composite fuel poverty measures were most consistently associated with cold weather-related adverse health or social outcomes.

Conclusions

This review identified socioeconomic, housing and behavioural factors associated with a range of cold weather-related adverse health or social outcomes. Only tentative conclusions can be drawn due to the limitations of existing research. More robust studies are needed to address the methodological issues identified and uncover causal associations. A review of qualitative and intervention studies would help to inform policies to reduce the adverse health and social impacts of cold weather.
Development, validation, and application of a model of intra- and inter-tree variability of wood density for lodgepole pine in western Canada
Authors: Peng Mingkai , Stewart James D.
Published: October 2013

Wood density is an important characteristic for evaluating wood quality and estimating tree biomass. The ring-level focus of most density models requires inputs and produces predictions at a scale at which industry does not currently operate. Our objective was to develop a model at a scale intermediate between ring and tree levels that would capture the significant, operationally relevant variability that exists within lodgepole pine (Pinus contorta Douglas ex Loudon) trees. We developed a model for estimating mean wood density for groups of five growth rings using a nonlinear mixed-effects modelling approach. The data were collected from six long-term silviculture research trials in Alberta and British Columbia, Canada. An independent data set from west-central Alberta was used for validation. Our results indicated that the density variation pattern can be reproduced using ring width and distance from pith as fixed effects and including site- and tree-level attributes as random effects. The stochastic variation of density among trees was large. Based on the estimated tree-level random effect distribution, prediction bands conditional on simulated random effects were proposed to assess intertree variability of density within a site. Estimation of site-level random effects may reduce bias for sites with low or high wood density.
Amplifying long transcripts of ryanodine receptors of five agricultural pests by transcriptome analysis and gap filling
Authors: Liu Yonglei , Shahzad Muhammad Faisal , Zhang Lan , Li Fei , Lin Kejian
Published: October 2013

Ryanodine receptor (RyR) is an intracellular calcium release channel that plays a key role in excitation contraction coupling. Insect RyR is the target of diamide insecticides. Better understanding of insect RyR is necessary for studying the molecular mode of action and potential resistance mechanism of diamide insecticides. However, molecular manipulation of the full RyR gene is difficult because of its length (approximately 15 kb). At present, RyR genes have been reported only in a limited number of insects. Here, we developed an efficient strategy to amplify full-length transcripts of insect RyR genes. First, we searched the transcriptomes of five insects, Bemisia tabaci, Cnaphalocrocis medinalis, Chilo suppressalis, Laodelphgax striatellus, and Plutella xylostella, yielding 85 RyR contigs in total. Second, the relative positions of these contigs in RyR transcripts were determined by aligning them with 12 well-annotated RyRs. Third, we designed primers to fill gaps between contigs and used rapid amplification of cDNA ends (RACE) to amplify both 5′- and 3′-ends. Last, we assembled all fragments into long transcripts. As a result, full-length transcripts of three insects, C. suppressalis, L. striatellus, and P. xylostella, were obtained. The RyR transcript of B. tabaci was near full length, containing an intact ORF. Northern blot analysis indicated that RyR genes were expressed in all five insects. Sequence analyses showed that the amplified insect segments contained typical RyRs characteristics, such as EF-hand, motif GVRAGGGIGD, and six transmembrane domains. Seven lepidopteran-specific amino acid residues were found to be located in the C-terminal region of RyR proteins, which might be associated with the specificity of RyRs to diamide insecticides.
SPECTRAL PROPERTIES OF DYNAMICAL LOCALIZATION FOR SCHRÖDINGER OPERATORS
Authors: GERMINET FRANÇOIS , TAARABT AMAL
Published: October 2013

We investigate the equivalence between dynamical localization and localization properties of eigenfunctions of Schrödinger Hamiltonians. We introduce three classes of equivalent properties and study the relationships between them. These relationships are optimal as shown by counterexamples.
Isotope geochemistry (O, H and Sr) of Late Cretaceous volcanic rocks, Haţeg Basin, South Carpathians, Romania
Authors: Bojar Ana-Voica , Dodd Justin , Seghedi Ioan
Published: October 2013

Oxygen and strontium isotopic ratios belonging to Late Cretaceous volcaniclastic deposits of the Haţeg Basin, South Carpathians, are documented here for the first time. The analyses performed on mineral concentrates suggest that associated magmas account for an assimilation–fractional crystallization trend with
87
Sr/
86
Sr ratios of between 0.705 and 0.706, and a large range of δ
18
O up to 16‰, and a trend with higher
87
Sr/
86
Sr ratios (0.707–0.708) but lower δ
18
O (8.2–7.9‰) values for leucrocratic minerals, such as plagioclase and sanidine. The Sr–O modelling of the main trend, using mafic minerals (pyroxene and amphibole), indicate 1–3% source contamination associated with up to 20% crustal assimilation. Hydrogen isotopic composition of amphiboles, biotite and groundmass do not confirm any significant involvement of an external fluid, either hydrothermal or diagenetic.
The Cretaceous–Paleogene boundary in the East Carpathians, Romania: evidence from geochemistry, mineralogy and calcareous nannofossils
Authors: Bojar Ana-Voica , Bojar Hans-Peter
Published: October 2013

We performed detailed geochemical, mineralogical and calcareous nannofossils investigations on two Maastrichtian–Paleocene sections situated in the Eastern Carpathians, Romania. One of the sections is situated in the Carpathian bend area, in the Ialomiţa Valley and is composed of red marine hemipelagic sediments. The other section is located in the northern region of the Eastern Carpathians, along Varniţa Brook and consists mainly of turbidites. In both sections, the Cretaceous–Paleogene (K–Pg) boundary is characterized by nannoplankton mass extinction (over 90%) of the Cretaceous nannofloras, followed by blooms of survivor taxa, such as the calcareous dinoflagellate genus
Thoracosphaera
and the nannofloral species
Braarudosphaera bigelowii
. In the Ialomiţa section, the K–Pg boundary is marked by a drop in calcite and TOC content, as well as a negative excursion in the δ
13
C values of organic material. These trends are only partly present in the Varniţa Brook section, where both calcite and TOC content show a decrease, but no negative excursion is seen in the δ
13
C values of organic material.