bluuebunny/crossref_metadata_2025 huggingface dataset:
Eight Years of Specialist Training of Dutch Intellectual Disability Physicians: Results of Scientific Research Education
Authors: Evenhuis Heleen M. , Penning Corine
Published: December 2009

Training in scientific research methods and skills is a vital part of Dutch specialist training in intellectual disability medicine. The authors evaluated results of such training at one Dutch university medical facility that had an obligatory research program involving projects conducted by the physicians‐in‐training (topics, teamwork, acquired competencies, and products). Since 2000, 28 research projects were started, and 24 of them were completed by teams made up of two to five trainees. Project topics included syndrome‐related comorbidity (n = 8), lifestyle (n = 2), specific medical conditions (n = 5), diagnostic methods (n = 5), and care by intellectual disability physicians (n = 8). Sixteen of the study designs were cross‐section observational, five were retrospective file reviews, one dealt with instrument development, three were qualitative, and three were literature studies. Structured exit evaluation interviews with 57 trainees (20 teams) showed that teamwork was appreciated positively by 17 of the teams, negatively by one, and mixed by two teams. While skills in literature search were reported as competencies present prior to the specialist training, additional basic scientific competencies were reported as acquired or improved by over 50% of trainees (including translating clinical into research questions, literature appraisal, protocol writing, data collection in the field, data entry, critical–analytical competency, and dealing with feedback and criticism). Trainee end products include 16 written reports, three journal articles in Dutch‐language publications, eight articles in international journals, and 14 international congress presentations/publications.
Defining “Sexualized Challenging Behavior” in Adults With Intellectual Disabilities
Authors: Lockhart Karen , Guerin Suzanne , Shanahan Sean , Coyle Kevin
Published: December 2009

Inappropriate sexual behaviors are a subset of challenging behaviors that limit the community integration of individuals with intellectual disabilities. Despite the stigmatizing effect of problematic sexual behavior, research efforts in this area have been limited and often used narrow prospective definitions. As such, research has been limited to a focus on “sexual offending” and “abuse,” terms which are often criticized in their applicability to people with intellectual disabilities given their connotations of criminal intent or insight. The authors propose adopting the term “sexualized challenging behavior” and define it by using empirical methods. Using a qualitative methodology, they examined a six‐month sample of service‐based documentation reporting sexual behaviors that were problematic. They also conducted semi‐structured interviews with a staff‐based sample and explored their views in relation to sexual behavior. Common themes emerged across both documentation and staff interviews regarding the nature and characteristics of such behaviors. Their proposed definition encompasses a continuum of self‐ and other‐directed behaviors related to touch, exposure, and communication, which they view as distinct from sexual offending. The findings further suggest that sexualized challenging behaviors have distinct characteristics that differentiate them from nonsexualized challenging behaviors. The authors conclude that sexualized challenging behaviors can be defined as a distinct class of behaviors that require further study among a broader cohort of adults with intellectual disabilities.
Strength of Habitat and Landscape Metrics in Predicting Golden‐Headed Lion Tamarin Presence or Absence in Forest Patches in Southern Bahia, Brazil
Authors: Raboy Becky E. , Neves Leonardo G. , Zeigler Sara , Saraiva Nicholas A. , Cardoso Nayara , dos Santos Gabriel Rodrigues , Ballou Jonathan D. , Leimgruber Peter
Published: December 2009

We investigated the effects of forest fragmentation on golden‐headed lion tamarins (Leontopithecus chrysomelas) by qualitatively and quantitatively characterizing the landscape throughout the species range, conducting surveys, and exploring predictive models of presence and absence. We identified 784 forest patches that varied in size, shape, core area, habitat composition, elevation, and distance to neighboring patches and towns. We conducted 284 interviews with local residents and 133 playback experiments in 98 patches. Results indicated a reduction in the western portions of the former species range. We tested whether L. chrysomelas presence or absence was related to the aforementioned fragmentation indices using Monte Carlo logistic regression techniques. The analysis yielded a majority of iterations with a one‐term final model of which Core Area Index (percent of total area that is core) was the only significant type. Model concordance ranged between 65 and 90 percent. Area was highlighted for its potential predictive ability. Although final models for area lacked significance, their failure to reach significance was marginal and we discuss potential confounding factors weakening the term's predictive ability. We conclude that lower Core Area Index scores are useful indicators of forest patches at risk for not supporting L. chrysomelas. Taken together, our analyses of the landscape, survey results, and logistic regression modeling indicated that the L. chrysomelas metapopulation is facing substantial threat. The limited vagility of lion tamarins in nonforest matrix may lead to increasingly smaller and inbred populations subject to significant impact from edge effects and small population size. Local extinction is imminent in many forest patches in the L. chrysomelas range.
Probing the corticospinal link between the motor cortex and motoneurones: some neglected aspects of human motor cortical function
Authors: Petersen N. C. , Butler J. E , Taylor J. L , Gandevia S. C.
Published: December 2009

This review considers the operation of the corticospinal system in primates. There is a relatively widespread cortical area containing corticospinal outputs to a single muscle and thus a motoneurone pool receives corticospinal input from a wide region of the cortex. In addition, corticospinal cells themselves have divergent intraspinal branches which innervate more than one motoneuronal pool but the synergistic couplings involving the many hand muscles are likely to be more diverse than can be accommodated simply by fixed patterns of corticospinal divergence. Many studies using transcranial magnetic stimulation of the human motor cortex have highlighted the capacity of the cortex to modify its apparent excitability in response to altered afferent inputs, training and various pathologies. Studies using cortical stimulation at ‘very low’ intensities which elicit only short‐latency suppression of the discharge of motor units have revealed that the rapidly conducting corticospinal axons (stimulated at higher intensities) drive motoneurones in normal voluntary contractions. There are also major non‐linearities generated at a spinal level in the relation between corticospinal output and the output from the motoneurone pool. For example, recent studies have revealed that the efficacy of the human corticospinal connection with motoneurones undergoes activity‐dependent changes which influence the size of voluntary contractions. Hence, corticospinal drives must be sculpted continuously to compensate for the changing functional efficacy of the descending systems which activate the motoneurones. This highlights the need for proprioceptive monitoring of movements to ensure their accurate execution.
Molecular analyses of Xenopus laevis Mesp‐related genes
Authors: HITACHI Keisuke , KONDOW Akiko , DANNO Hiroki , NISHIMURA Yusuke , OKABAYASHI Koji , ASASHIMA Makoto
Published: December 2009

During vertebrate somitogenesis, somites bud off from the anterior end of the presomitic mesoderm (PSM). Mesodermal posterior (Mesp)‐related genes play essential roles in somitogenesis, particularly in the definition of the somite boundary position. Among vertebrates, two types of Mesp‐related genes have been identified: Mesp1 and Mesp2 in the mouse; Meso‐1 and Meso‐2 in the chicken; Xl‐mespa and Xl‐mespb (also known as Thylacine1) in the African clawed frog (Xenopus laevis); and mesp‐a and mesp‐b in the zebrafish. However, the functional differences between two Mesp‐related genes remain unknown. In the present study, we carried out comparative analyses of the Xl‐mespa and Xl‐mespb genes. The amino acid sequences of the Xl‐mespa and Xl‐mespb proteins showed a high level of similarity. The expression of Xl‐mespa started broadly in the ventrolateral mesoderm and gradually shifted to a striped pattern of expression. In contrast, Xl‐mespb showed a striped pattern of expression from the start. These expression profiles completely overlapped at the PSM during somitogenesis. To investigate the functional differences between Xl‐mespa and Xl‐mespb in terms of target gene regulation, we carried out a luciferase assay using the murine Lunatic fringe (L‐fng) promoter. Transcription of the L‐fng promoter was activated more strongly by Xl‐mespb than by Xl‐mespa. This same pattern was observed for the murine Mesp‐related proteins. These results suggest that the functional differences between the two types of Mesp‐related genes are evolutionally conserved in vertebrates.
Canada's inter‐agency wild bird influenza survey
Authors: PARMLEY Jane , LAIR Stéphane , LEIGHTON Frederick A.
Published: December 2009

Canada's Inter‐agency Wild Bird Influenza Survey, which started in 2005, and is a collaborative effort among federal, provincial and territorial government agencies as well as non‐governmental organizations and academic institutions, has two components: (i) a seasonal survey of live wild waterfowl species from selected geographic regions across Canada (to expand our understanding of the avian influenza viruses circulating in wild bird populations); and (ii) an ongoing survey of birds found dead that are submitted to a regional diagnostic laboratory (to enhance detection of highly pathogenic avian influenza strains). Combined swabs from the cloaca and oropharynx collected from each bird are screened using a real‐time reverse transcriptase‐polymerase chain reaction (RRT‐PCR) that targets a unique segment of the influenza A M1 gene. If the M1 result is positive or inconclusive, RRT‐PCR for gene segments of the H5 and H7 hemagglutinin subtypes are performed. All samples that are RRT‐PCR positive for H5 or H7 are sent immediately for test confirmation and further characterization. All field and laboratory data are entered into a database developed and maintained by the Canadian Cooperative Wildlife Health Centre. Since the survey commenced in 2005, on average, 30% of all live ducks sampled, 5% of other species of live birds and 3% of birds found dead have tested positive for avian influenza, all of North American lineage and of low pathogenicity.
Finite Element Thermal/Mechanical Analysis of Transmission Laser Microjoining of Titanium and Polyimide
Authors: Dhorajiya Ankitkumar P. , Mayeed Mohammed S. , Auner Gregory W. , Baird Ronald J. , Newaz Golam M. , Patwa Rahul , Herfurth Hans
Published: December 2009

Detailed analysis of a residual stress profile due to laser microjoining of two dissimilar biocompatible materials, polyimide (PI) and titanium (Ti), is vital for the long-term application of bio-implants. In this work, a comprehensive three-dimensional (3D) transient model for sequentially coupled thermal/mechanical analysis of transmission laser (laser beam with wavelength of 1100 nm and diameter of 0.2 mm) microjoining of two dissimilar materials has been developed by using the finite element code ABAQUS, along with a moving Gaussian laser heat source. First the model has been used to optimize the laser parameters like laser traveling speed and power to obtain good bonding (burnout temperature of PI>maximum temperature of PI achieved during heating>melting temperature of PI) and a good combination has been found to be 100 mm/min and 3.14 W for a joint-length of 6.5 mm as supported by the experiment. The developed computational model has been observed to generate a bonding zone that is similar in width (0.33 mm) to the bond width of the Ti/PI joint observed experimentally by an optical microscope. The maximum temperatures measured at three locations by thermocouples have also been found to be similar to those observed computationally. After these verifications, the residual stress profile of the laser microjoint (100 mm/min and 3.14 W) has been calculated using the developed model with the system cooling down to room temperature. The residual stress profiles on the PI surface have shown low value near the centerline of the laser travel, increased to higher values at about 165 μm from the centerline symmetrically at both sides, and to the contrary, have shown higher values near the centerline on the Ti surface. Maximum residual stresses on both the Ti and PI surfaces are obtained at the end of laser travel, and are in the orders of the yield stresses of the respective materials. It has been explained that the patterned accumulation of residual stresses is due to the thermal expansion and contraction mismatches between the dissimilar materials at the opposite sides of the bond along with the melting and softening of PI during the joining process.
Characterization of Integrated Functionally Gradient Syntactic Foams
Authors: Chittineni Kanakaji , Woldesenbet Eyassu
Published: December 2009

Light weight high strength composites can be obtained by reinforcing resin with fillers such as hollow or solid particles and fibers. Composites were fabricated using microballoons (hollow particles) called syntactic foams. These foams can be used in various low density applications such as buoyancy aid materials for deep sea exploration and aerospace vehicles. These foams are usually utilized as light weight core materials for sandwich structures. The present study explores the procedure to fabricate functionally gradient syntactic foams (FGSFs) and further analyze their mechanical properties. The FGSFs produced are gradient structures consisting of four layers with four different types of microballoons, namely, S22, S32, S38, and K46, each having different wall thickness. The volume fraction of all microballoons is maintained constant at 60% to maintain light weight structures. Several FGSF specimens having similar density are fabricated with different layer arrangements. The different layers are integrated before major solidification takes place. Quasistatic compression testing is then performed on the cured FGSF samples using MTS-810 servohydraulic machine. Compressive strength and energy absorption values for each arrangement are compared. The stress plateau in integrated FGSF composites extends from 10% to 60% strain compared with plain syntactic foams. The integrated FGSF shows increment in yield strength and energy absorption compared with adhesively bonded FGSF. It is found that the compressive strength and energy absorption of integrated FGSF composites can be varied based on arrangement of the layers.
Minimizing Defects Between Adjacent Foils in Ultrasonically Consolidated Parts
Authors: Obielodan J. O. , Ram G. D. Janaki , Stucker B. E. , Taggart D. G.
Published: December 2009

Two types of defects normally occur in ultrasonically consolidated parts: (i) Defects that occur between mating foils in successive layers (“type 1” defects) and (ii) defects that occur within a layer between two foils laid side-by-side (“type 2” defects). While some success has been achieved in minimizing type 1 defects, type 2 defects, however, have been given very little attention. Both types of defects are undesirable and should be minimized if ultrasonically consolidated parts are to be used in structural applications. This work describes an investigation of how to minimize type 2 defects in ultrasonically consolidated parts. According to our hypothesis, a foil being deposited must overlap the adjacent deposited foil by an optimum amount to ensure a defect-free joint between the two foils. Transverse tensile specimens were fabricated with various amounts of foil overlap (by changing the foil width setting) to test this hypothesis. Metallographic and fractographic studies showed a clear correlation between foil overlap, defect incidence, and tensile strength. It was found that a foil width setting of 23.81 mm helps minimize type 2 defects in ultrasonically consolidated Al 3003 parts using standard foils of 23.88 mm (equivalent to 0.94 in.) nominal width.
Dual-Axis Hole-Drilling ESPI Residual Stress Measurements
Authors: Schajer Gary S. , Steinzig Michael
Published: December 2009

A novel dual-axis ESPI hole-drilling residual stress measurement method is presented. The method enables the evaluation of all the in-plane normal stress components with similar response to measurement errors, significantly lower than with single-axis measurements. A numerical method is described that takes advantage of, and compactly handles, the additional optical data that are available from the second measurement axis. Experimental tests were conducted on a calibrated specimen to demonstrate the proposed method, and the results supported theoretical expectations.
Development of Strong Surfaces Using Functionally Graded Composites Inspired by Natural Teeth—Finite Element and Experimental Verification
Authors: Zisis Th. , Kordolemis A. , Giannakopoulos A. E.
Published: December 2009

Functionally graded materials (FGMs) are composite materials that exhibit a microstructure that varies locally in order to achieve a specific type of local material properties distribution. In recent years, FGMs appear to be more interesting in engineering application since they present an enhanced performance against deformation, fracture, and fatigue. The purpose of the present work is to present evidence of the excellent strength properties of a new graded composite that is inspired by the human teeth. The outer surface of the teeth exhibits high surface strength while it is brittle and wear resistant, whereas the inner part is softer and flexible. The specific variation in Young’s modulus along the thickness of the presented composite is of particular interest in our case. The present work presents a finite element analysis and an experimental verification of an actual composite with elastic modulus that follows approximately the theoretical distribution observed in the teeth.
Infrared Radiative Properties of Heavily Doped Silicon at Room Temperature
Authors: Basu S. , Lee B. J. , Zhang Z. M.
Published: December 2009

This paper describes an experimental investigation on the infrared radiative properties of heavily doped Si at room temperature. Lightly doped Si wafers were ion-implanted with either boron or phosphorus atoms, with dosages corresponding to as-implanted peak doping concentrations of 1020 and 1021 cm−3; the peak doping concentrations after annealing are 3.1×1019 and 2.8×1020 cm−3, respectively. Rapid thermal annealing was performed to activate the implanted dopants. A Fourier-transform infrared spectrometer was employed to measure the transmittance and reflectance of the samples in the wavelength range from 2 μm to 20 μm. Accurate carrier mobility and ionization models were identified after carefully reviewing the available literature, and then incorporated into the Drude model to predict the dielectric function of doped Si. The radiative properties of doped Si samples were calculated by treating the doped region as multilayer thin films of different doping concentrations on a thick lightly doped Si substrate. The measured spectral transmittance and reflectance agree well with the model predictions. The knowledge gained from this study will aid future design and fabrication of doped Si microstructures as wavelength selective emitters and absorbers in the midinfrared region.
An Extension of the Large-Cell Radiation Model for the Case of Semitransparent Nonisothermal Particles
Authors: Dombrovsky Leonid A.
Published: December 2009

The recently developed model for thermal radiation in multiphase flows typical of melt-coolant interactions is generalized to account for transient temperature profile in large semitransparent particles of solidifying melt. A modification of the large-cell radiation model (LCRM) is based on the approximate solution for coupled radiation and conduction in optically thick spherical particles of a refractive material. The simplicity of the suggested approximation enables one to implement the modified model in a multiphase computational fluid dynamics code. The LCRM extension makes possible the use of this approach not only for the core melt in nuclear fuel-coolant interactions but also for other melt substances, which are widely used in the laboratory experiments. The numerical data demonstrate an effect of absorption coefficient of the particle substance on the rate of particle cooling and solidification.
Experimental and Computational Characterization of High Heat Fluxes During Transient Blackbody Calibrations
Authors: Abdelmessih Amanie N. , Horn Thomas J.
Published: December 2009

High heat fluxes are encountered in numerous applications, such as on the surfaces of hypersonic vehicles in flight, in fires, and within engines. The calibration of heat flux gauges may be performed in a dual cavity cylindrical blackbody. Insertion of instruments into the cavity disturbs the thermal equilibrium resulting in a transient calibration environment. To characterize the transient heat fluxes, experiments were performed on a dual cavity cylindrical blackbody at nominal temperatures varying from 800°C to 1900°C in increments of 100°C. The pre-insertion, steady state, axial temperature profile is compared experimentally and numerically. Detailed transient thermal models have been developed to simulate the heat flux calibration process at two extreme fluxes: the high flux is 1 MW/m2 and the relatively low is 70 kW/m2. Based on experiments and numerical analysis, the optimum heat flux sensor insertion location as measured from the center partition was determined. The effect of convection (natural and forced) in the blackbody cavity during the insertion is calculated and found to be less than 2% at high temperatures but reaches much higher values at relatively lower temperatures. The transient models show the effect of inserting a heat flux gauge at room temperature on the thermal equilibrium of the blackbody at 1800°C and 800°C nominal temperatures. Also, heat flux sensor outputs are derived from computed sensor temperature distributions and compared with experimental results. The numerical heat flux agreed with the experimental results to within 5%, which indicates that the numerical models captured the transient thermal physics during the calibration. Based on numerical models and all experimental runs the heat transfer mechanisms are explained.
An Efficient Sparse Finite Element Solver for the Radiative Transfer Equation
Authors: Widmer Gisela
Published: December 2009

The stationary monochromatic radiative transfer equation is posed in five dimensions, with the intensity depending on both a position in a three-dimensional domain as well as a direction. For nonscattering radiative transfer, sparse finite elements [2007, “Sparse Finite Elements for Non-Scattering Radiative Transfer in Diffuse Regimes,” ICHMT Fifth International Symposium of Radiative Transfer, Bodrum, Turkey; 2008, “Sparse Adaptive Finite Elements for Radiative Transfer,” J. Comput. Phys., 227(12), pp. 6071–6105] have been shown to be an efficient discretization strategy if the intensity function is sufficiently smooth. Compared with the discrete ordinates method, they make it possible to significantly reduce the number of degrees of freedom N in the discretization with almost no loss of accuracy. However, using a direct solver to solve the resulting linear system requires O(N3) operations. In this paper, an efficient solver based on the conjugate gradient method with a subspace correction preconditioner is presented. Numerical experiments show that the linear system can be solved at computational costs that are nearly proportional to the number of degrees of freedom N in the discretization.
Tomography-Based Heat and Mass Transfer Characterization of Reticulate Porous Ceramics for High-Temperature Processing
Authors: Haussener Sophia , Coray Patrick , Lipiński Wojciech , Wyss Peter , Steinfeld Aldo
Published: December 2009

Reticulate porous ceramics employed in high-temperature processes are characterized for heat and mass transfer. The exact 3D digital geometry of their complex porous structure is obtained by computer tomography and used in direct pore-level simulations to numerically calculate their effective transport properties. Two-point correlation functions and mathematical morphology operations are applied for the geometrical characterization that includes the determination of porosity, specific surface area, representative elementary volume edge size, and mean pore size. Finite volume techniques are applied for conductive/convective heat transfer and flow characterization, which includes the determination of the thermal conductivity, interfacial heat transfer coefficient, permeability, Dupuit–Forchheimer coefficient, residence time, tortuosity, and diffusion tensor. Collision-based Monte Carlo method is applied for the radiative heat transfer characterization, which includes the determination of the extinction coefficient and scattering phase function.
Transient Radiation and Conduction Heat Transfer in Glass Sheets by the Thin Layer Approximation
Authors: El Hitti Georges , Nemer Maroun , El Khoury Khalil
Published: December 2009

This paper is devoted to the simulation of 3D transient radiation and conduction heat transfer occurring inside thin glass sheets undergoing high temperature processing. The glass is considered as an absorbing, emitting, and nonscattering medium. The zonal method is used to establish the governing radiation transfer model. Direct exchange areas are calculated by the flux planes approximation. The thin layer approximation (TLA) is then introduced for increasing CPU efficiency. Three different numerical integration schemes made possible by the TLA are presented. Comparisons are made, with calculations performed using the finite volume method (FVM). The transient coupled energy equation is solved by a full implicit control volume method using the incomplete Cholesky conjugate gradient method. The heat transfer analysis of a glass sheet residing inside a hot rectangular enclosure is studied. Results obtained by the zonal method, with or without the TLA, are in close agreement with those obtained by the FVM. CPU requirements for radiative heat transfer analysis of the zonal method with TLA are, depending on the numerical integration scheme used, between 8 and 23 times smaller than those of the zonal method without TLA. The difference between the results of the different models never exceeds 4%. The zonal method with the TLA offered significant improvements in CPU time when compared with the original zonal method with similar or acceptable accuracy.
Green’s Function Approach to Nonlinear Conduction and Surface Radiation Problems
Authors: Jones Matthew R. , Solovjov Vladimir P.
Published: December 2009

An exact approach for solving both transient and steady state conduction and surface radiation problems is presented. The method is based on the use of Green’s function, and the temperature field is obtained by solving an integral equation. This is in contrast to the approach presented in radiative heat transfer texts in which temperature profiles are obtained from the simultaneous solution of coupled integral and differential equations. The analysis presented in this paper provides insight into the solution of this important class of problems. The method is illustrated by solving two representative problems. The first problem considered is the steady state analysis of a radiating fin. The second problem considered is the transient analysis of a radiating target, which is used to determine the temporal response of radiation thermometers.
Radiative Transfer in Dispersed Media: Comparison Between Homogeneous Phase and Multiphase Approaches
Authors: Randrianalisoa Jaona , Baillis Dominique
Published: December 2009

The radiative transfer in dispersed media in the geometric optic regime is investigated through two continuum-based approaches. The first one is the traditional treatment of dispersed media as continuous and homogeneous systems, referred here as the homogeneous phase approach (HPA). The second approach is based on a separate treatment of the radiative transfer in the continuous and dispersed phases, referred here as the multiphase approach (MPA). The effective radiative properties involved in the framework of the HPA are determined using the recent ray-tracing (RT) method, enabled to overcome the modeling difficulties such as the dependent scattering effects and the misunderstanding of the effective absorption coefficient. The two modeling approaches are compared with the direct Monte Carlo simulation. It is shown that (i) the HPA combined with effective radiative properties, such as those from the RT method, is satisfactory in analyzing the radiative transfer in dispersed media constituting of transparent, semitransparent, or opaque particles. Therefore, the use of more complex continuum models such as the dependence included discrete ordinate method (Singh, B. P., and Kaviany, M., 1992, “Modelling Radiative Heat Transfer in Packed Beds,” Int. J. Heat Mass Transfer, 35, pp. 1397–1405) is not imperative anymore. (ii) The MPA, though a possible candidate to handle nonequilibrium problems, is suitable if the particle (geometric) backscattering is weak or absent. It is the case, for example, for dispersed media constituted of opaque particles or air bubbles. However, caution should be taken with the MPA when dealing with the radiative transfer in dispersed media constituted of nonopaque particles having refractive indexes greater than that of the continuous host medium.
An Efficient Method for Radiative Heat Transfer Applied to a Turbulent Channel Flow
Authors: Sakurai Atsushi , Maruyama Shigenao , Matsubara Koji , Miura Takahiro , Behnia Masud
Published: December 2009

The purpose of this paper is to consider a possibility of the independent column approximation for solving the radiative heat fluxes in a 3D turbulent channel flow. This simulation method is the simplest extension of the plane-parallel radiative heat transfer. The test case of the temperature profile was obtained from the direct numerical simulation. We demonstrate the comparison between the 3D radiative transfer simulation and the independent column approximation with an inhomogeneous temperature field and optical properties. The above mentioned results show the trivial discrepancies between the 3D simulation and the independent column approximation. The required processing time for the independent column approximation is much faster than the 3D radiative transfer simulation due to the simple algorithm. Although the independent column simulation is restricted to simple configurations such as channel flow in this paper, wide application areas are expected due to the computational efficiency.
Spectral Module for Photon Monte Carlo Calculations in Hypersonic Nonequilibrium Radiation
Authors: Ozawa Takashi , Modest Michael F. , Levin Deborah A.
Published: December 2009

In this paper, efficient spectral modules and random number databases are developed for atomic and diatomic species for use in photon Monte Carlo (PMC) modeling of hypersonic nonequilibrium flow radiation. To model nonequilibrium flow conditions, the quasisteady state assumption was used to generate electronic state populations of atomic and diatomic gas species in the databases. For atomic species (N and O), both bound-bound transitions and continuum radiation were included and were separately databased as a function of electron temperature and number density as well as the ratio of atomic ion to neutral number density. For the radiating diatomic species of N2+, N2, O2, and NO databases were generated for each electronic molecular electronic system. In each molecular electronic system, the rovibrational transition lines were separately databased for each electronic upper state population forming the electronic system. The spectral module for the PMC method was optimized toward computational efficiency for emission calculations, wavelength selections of photon bundles and absorption coefficient calculations in the ray tracing scheme.
A Wireless System for Evaluating Postural Position
Authors: Sipp Amy R. , Rowley Blair A.
Published: December 2009

Falls account for almost two million emergency department visits per year in the United States and are the leading cause of injury deaths among adults 65 years of age and older. Despite efforts to reduce fall risk factors, about one-third of community-dwelling older adults fall each year in the United States. New methods and devices are needed to prevent falls and to reduce morbidity and mortality related to falls. Presently, it is unknown if there is a measurable change in sway before a person falls as a result of age or medical condition. The purpose of this research is to develop a device that can be used to measure the prefall motion outside of a laboratory setting. To study human prefall motion, we developed a gyroscope-based sensor to test two concepts. The first was that a single-axis gyroscope could be used to directly measure angular position changes due to postural perturbations. The second was that a small widely used microprocessor could be used to distinguish normal from potentially problematic motion. This proof-of-concept prototype counted how many times perturbations occurred that were unlikely to be due to normal activities such as walking and stair climbing. With these basic concepts demonstrated, we sought to expand the device into a more versatile form using the same general approach. A wireless data acquisition system was developed. A fall was induced to allow the study of prefall motion on a healthy subject. The data collected showed a measureable change in postural motion. The developed device provides a viable approach to evaluating postural angular position that can be used outside of a laboratory facility. Further testing and development will involve additional subject testing and expansion of the device to function as an early fall detection or warning system. This research serves as a basis for further work in postural sway and interventions to prevent falls.
A Better Bionic Heart
Authors: Kelner Katrina L.
Published: December 2009

Patients with a new type of heart pump that has a rotor to drive blood flow instead of a piston survive better because they have fewer complications.
Grow Your Own Stem Cells
Authors: LaMarco Kelly
Published: December 2009

Induced pluripotent stem cells grown on their own parent fibroblasts are stable and lack common culture-related problems, paving the way for production of clinical-grade iPS cells.
Lipid Liaison
Authors: Khidr Lily
Published: December 2009

A lipid chaperone in macrophages links ER stress with atherosclerosis.
Measuring Metastatic Melanoma's Risk
Authors: McDonald Heather B.
Published: December 2009

Patients with melanomas that express more immune-related genes and show less cell division have a better chance of survival.
Voltammetric and amperometric determination of doxorubicin using carbon paste electrodes
Authors: Jemelková Zuzana , Zima Jiří , Barek Jiří
Published: December 2009

Direct current voltammetric (DCV) and differential pulse voltammetric (DPV) determination of antineoplastic agent doxorubicin (DOX) at a carbon paste electrode (CPE) was developed. Britton–Robinson buffer (pH 7.0) was used as a supporting electrolyte. The limits of detection are 8 × 10–7 mol l–1 (DCV) and 6 × 10–8 mol l–1 (DPV). The accumulation of DOX at the electrode surface was used to decrease the limits of detection down to 2.2 × 10–7 mol l–1 for adsorptive stripping DC voltammetry (DCAdSV) and 2.8 × 10–9 mol l–1 for adsorptive stripping differential pulse voltammetry (DPAdSV) at CPE. The results of the voltammetric methods were utilized for the development of a new determination of doxorubicin using HPLC with amperometric detection on CPE based on spherical microparticles of glassy carbon in a wall-jet configuration. A column with chemically bonded C18 stationary phase and a mobile phase containing 0.01 M phosphate buffer (pH 5.0)–methanol 25:75 (v/v) were used. The limit of detection is 4 × 10–7 mol l–1 (HPLC with electrochemical detection (ED)).
Integration of subclassification strategies in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for non-specific chronic low back pain: a systematic review
Authors: Fersum K V , Dankaerts W , O'Sullivan P B , Maes J , Skouen J S , Bjordal J M , Kvåle A
Published: December 2009

Background

There is lack of evidence for specific treatment interventions for patients with non-specific chronic low back pain (NSCLBP) despite the substantial amount of randomised controlled clinical trials evaluating treatment outcome for this disorder.

Hypothesis

It has been hypothesised that this vacuum of evidence is caused by the lack of subclassification of the heterogeneous population of patients with chronic low back pain for outcome research.

Study design

A systematic review.

Methods

A systematic review with a meta-analysis was undertaken to determine the integration of subclassification strategies with matched interventions in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for NSCLBP. A structured search for relevant studies in Embase, Cinahl, Medline, PEDro and the Cochrane Trials Register database, followed by hand searching all relevant studies in English up to December 2008.

Results

Only 5 of 68 studies (7.4%) subclassified patients beyond applying general inclusion and exclusion criteria. In the few studies where classification and matched interventions have been used, our meta-analysis showed a statistical difference in favour of the classification-based intervention for reductions in pain (p=0.004) and disability (p=0.0005), both for short-term and long-term reduction in pain (p=0.001). Effect sizes ranged from moderate (0.43) for short term to minimal (0.14) for long term.

Conclusion

A better integration of subclassification strategies in NSCLBP outcome research is needed. We propose the development of explicit recommendations for the use of subclassification strategies and evaluation of targeted interventions in future research evaluating NSCLBP.
LXRβ is the dominant LXR subtype in skeletal muscle regulating lipogenesis and cholesterol efflux
Authors: Hessvik N. P. , Boekschoten M. V. , Baltzersen M. A. , Kersten S. , Xu X. , Andersén H. , Rustan A. C. , Thoresen G. H.
Published: December 2009

Liver X receptors (LXRs) are important regulators of cholesterol, lipid, and glucose metabolism and have been extensively studied in liver, macrophages, and adipose tissue. However, their role in skeletal muscle is poorly studied and the functional role of each of the LXRα and LXRβ subtypes in skeletal muscle is at present unknown. To study the importance of each of the receptor subtypes, myotube cultures derived from wild-type (WT) and LXRα and LXRβ knockout (KO) mice were established. The present study showed that treatment with the LXR agonist T0901317 increased lipogenesis and apoA1-dependent cholesterol efflux in LXRα KO and WT myotubes but not in LXRβ KO cells. The functional studies were confirmed by T0901317-induced increase in mRNA levels of LXR target genes involved in lipid and cholesterol metabolism in myotubes established from WT and LXRα KO mice, whereas only minor changes were observed for these genes in myotubes from LXRβ KO mice. Gene expression analysis using microarrays showed that very few genes other than the classical, well-known LXR target genes were regulated by LXR in skeletal muscle. The present study also showed that basal glucose uptake was increased in LXRβ KO myotubes compared with WT myotubes, suggesting a role for LXRβ in glucose metabolism in skeletal muscle. In conclusion, LXRβ seems to be the main LXR subtype regulating lipogenesis and cholesterol efflux in skeletal muscle.
Regulation of gonadotropin-releasing hormone-1 gene transcription by members of the purine-rich element-binding protein family
Authors: Zhao Sheng , Kelm Robert J. , Fernald Russell D.
Published: December 2009

Gonadotropin-releasing hormone-1 (GnRH1) controls reproduction by stimulating the release of gonadotropins from the pituitary. To characterize regulatory factors governing GnRH1 gene expression, we employed biochemical and bioinformatics techniques to identify novel GnRH1 promoter-binding proteins from the brain of the cichlid fish, Astatotilapia burtoni ( A. burtoni ). Using an in vitro DNA-binding assay followed by mass spectrometric peptide mapping, we identified two members of the purine-rich element-binding (Pur) protein family, Purα and Purβ, as candidates for GnRH1 promoter binding and regulation. We found that transcripts for both Purα and Purβ colocalize in GnRH1-expressing neurons in the preoptic area of the hypothalamus in A. burtoni brain. Furthermore, we confirmed in vivo binding of endogenous Purα and Purβ to the upstream region of the GnRH1 gene in A. burtoni brain and mouse neuronal GT1–7 cells. Consistent with the relative promoter occupancy exhibited by endogenous Pur proteins, overexpression of Purβ, but not Purα, significantly downregulated GnRH1 mRNA levels in transiently transfected GT1–7 cells, suggesting that Purβ acts as a repressor of GnRH1 gene transcription.
Effects of reduced frequency of milk removal on gene expression in the bovine mammary gland
Authors: Littlejohn M. D. , Walker C. G. , Ward H. E. , Lehnert K. B. , Snell R. G. , Verkerk G. A. , Spelman R. J. , Clark D. A. , Davis S. R.
Published: December 2009

Regulation of milk synthesis and secretion is controlled mostly through local (intramammary) mechanisms. To gain insight into the molecular pathways comprising this response, an analysis of mammary gene expression was conducted in 12 lactating cows shifted from twice daily to once daily milking. Tissues were sampled by biopsy from adjacent mammary quarters of these animals during the two milking frequencies, allowing changes in gene expression to be assessed within each animal. Using bovine-specific, oligonucleotide arrays representing 21,495 unique transcripts, a range of differentially expressed genes were found as a result of less frequent milk removal, constituting transcripts and pathways related to apoptotic signaling (NF-κB, JUN, ATF3, IGFBP5, TNFSF12A) mechanical stress and epithelial tight junction synthesis (CYR61, CTGF, THBS1, CLDN4, CLDN8), and downregulated milk synthesis (LALBA, B4GALT1, UGP2, CSN2, GPAM, LPL). Quantitative real-time PCR was used to assess the expression of 13 genes in the study, and all 13 of these were correlated ( P < 0.05) with values derived from array analysis. It can be concluded that the physiological changes that occur in the bovine mammary gland as a result of reduced milk removal frequency likely comprise the earliest stages of the involution response and that mechano-signal transduction cascades associated with udder distension may play a role in triggering these events.
Absence ofAVPR2copy number variation in eunatremic and dysnatremic subjects in non-Hispanic Caucasian populations
Authors: Fu Yi , Chen Zhan , Blakemore Alexandra I. F. , Orwoll Eric , Cohen David M.
Published: December 2009

Copy number variation (CNV) is increasingly recognized as a source of phenotypic variation among humans. We hypothesized that a CNV in the human arginine vasopressin receptor-2 gene ( AVPR2) would be associated with serum sodium concentration based on the following lines of evidence: 1) the protein product of the AVPR2 gene is essential for renal water conservation; 2) mutations in the AVPR2 gene are associated with aberrant water balance in humans; 3) heritability of serum sodium concentration may be greater in females than in males; 4) the AVPR2 gene is X-linked; and 5) a common CNV spanning the AVPR2 gene was recently described in a non-Hispanic Caucasian population. We developed a highly reproducible assay for AVPR2 CNV. Among 279 subjects with measured serum sodium concentration in the Offspring Cohort of the Framingham Heart Study, no subjects exhibited CNV at the AVPR2 locus. Among 517 subjects in the Osteoporotic Fractures in Men Study (MrOS)—including 152 with hyponatremia and 183 with hypernatremia—no subjects with CNV at the AVPR2 locus were identified. CNV at the AVPR2 locus could not be independently confirmed, and CNV at the AVPR2 gene is unlikely to influence systemic water balance on a population-wide basis in non-Hispanic Caucasian subjects. A novel AVPR2 single nucleotide polymorphism affecting the reporter hybridization site gave rise to an artifactually low copy number signal (i.e., less than unity) in one male African American subject. Reanalysis of the original comparative genomic hybridization data revealed bona fide CNVs flanking—but not incorporating—the AVPR2 gene, consistent with our new genotyping data.
Factitious Disorders and Cardiothoracic Surgery: The Ongoing Multidisciplinary Challenges of a Complex Case
Authors: Firstenberg Michael S. , Sirak John H. , Sun Benjamin , Kasick David P.
Published: December 2009

Chronic factitious disorder, Munchausen's syndrome, can be challenging to manage—particularly when complaints and symptoms suggest medical or surgical emergencies. We present a patient whose problems have spanned many years and a great distance. Hopefully, with a greater awareness of this disease, as this patient continues to seek health care in many different hospitals, the implications of timely access to information, good histories and physical exams, and an index of suspicion can assist in potentially avoiding unnecessary, expensive, and invasive evaluations.
Role of Ryanodine Receptor Subtypes in Initiation and Formation of Calcium Sparks in Arterial Smooth Muscle:Comparisonwith Striated Muscle
Authors: Essin Kirill , Gollasch Maik
Published: December 2009

Calcium sparks represent local, rapid, and transient calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial smooth muscle cells (SMCs), calcium sparks activate calcium‐dependent potassium channels causing decrease in the global intracellular [Ca2+] and oppose vasoconstriction. This is in contrast to cardiac and skeletal muscle, where spatial and temporal summation of calcium sparks leads to global increases in intracellular [Ca2+] and myocyte contraction. We summarize the present data on local RyR calcium signaling in arterial SMCs in comparison to striated muscle and muscle‐specific differences in coupling between L‐type calcium channels and RyRs. Accordingly, arterial SMC Cav1.2 L‐type channels regulate intracellular calcium stores content, which in turn modulates calcium efflux though RyRs. Downregulation of RyR2 up to a certain degree is compensated by increased SR calcium content to normalize calcium sparks. This indirect coupling between Cav1.2 and RyR in arterial SMCs is opposite to striated muscle, where triggering of calcium sparks is controlled by rapid and direct cross‐talk between Cav1.1/Cav1.2 L‐type channels and RyRs. We discuss the role of RyR isoforms in initiation and formation of calcium sparks in SMCs and their possible molecular binding partners and regulators, which differ compared to striated muscle.