bluuebunny/crossref_metadata_2025 huggingface dataset:
Ex Post Production Flexibility, Asset Specificity, and Financial Structure
Authors: Aivazian Varouj A. , Berkowitz Michael K.
Published: July 2017

This paper examines the interaction between the firm's production and financing decisions, focusing on the specificity of its assets and on the flexibility of its production technology. The paper shows that production flexibility increases potential tax shields from debt and lowers expected bankruptcy costs and that, when asset specificity is low, operating and financial leverage tend to be complements, with the complementarity becoming stronger as ex post capacity adjustment costs increase. It also shows that an increase in the corporate tax rate induces the firm to increase capacity investment and financial leverage when asset specificity is low and that this effect becomes stronger as ex post capacity adjustment costs increase. The results suggest that in industries where assets are easily redeployable, the impact of taxes on both investment and financial leverage will be positive and increasing with the size of capacity adjustment costs.
When Increasing the Strength of the Argument Becomes Counterproductive: The Role of Argumentative Markers in the Arousal of the Psychological Reactance
Authors: Coppola Vincent , Girandola Fabien
Published: July 2017

The rationale of this study is that by stressing the argumentative force of the message, and thus orientating its processing, scalar adverbs are likely to be processed as an attempt to influence the decision making as regards the message advocacy and consequently trigger some aversive reactions in the recipients. To support this claim, an experiment is conducted in a context of a (campus) health promotion program dealing with HIV infection. It shows that the introduction of such adverbs in an epidemiological information report increases the cognitive and affective outcomes dealing with psychological reactance, and decreases the message acceptability and the behavioral intentions. It also shows that for the affective component of psychological reactance and message acceptability, these effects occur especially when the source of the message is perceived as authoritative. The persuasiveness of such linguistic items in the context of health communication is addressed in the conclusion of the study.
Description of Adsorption of Iodine from Non-Aqueous Solutions on Active Carbon
Authors: Garbacz J. K. , Biniak S. , Swiatkowskit A.
Published: July 2017

A description is proposed of iodine adsorption on active carbon from solutions in six different organic solvents in terms of general criteria of thermodynamic equilibrium in liquid solutions of limited miscibility of the components. The numerical values of the parameters of the excess adsorption isotherm equation have been determined and the distribution function of the adsorption potential difference of the components, which characterizes the global adsorption heterogeneity of the system, has been calculated under the assumption that the tested mixtures behave like ideal solutions.
Energetics of the Adsorption–Desorption Cycles of Different Gases and Vapours on Cadmium Sulphide
Authors: Stradella Luigi , Damien Lidia Borrell
Published: July 2017

Adsorption–desorption cycles of some vapours and gases (water, ammonia, hydrogen, oxygen) on polycrystalline cadmium sulphide have been performed at 305 K by microcalorimetric means. Hydrogen and ammonia show the strongest interaction energy and the highest fraction of an irreversibly adsorbed phase. Water and oxygen exhibit weak and reversible adsorption. Various TPD measurements confirm this relative bonding order for these adsorbates.
A Novel Zeolite MCM-22: Sorption Characteristics
Authors: Ravishankar R. , Joshi P.N. , Tamhankar S.S. , Sivasanker S. , Shiralkar V.P.
Published: July 2017

Synthetic zeolites of MCM-22 type with different framework SiO2/Al2O3 ratios (ranging from 40 to 140) obtained by direct hydrothermal crystallisation were studied using different probe molecules. The influence of framework aluminium content on the BET surface area and on the micropore void volume was examined using low-temperature argon sorption. Sorption uptake using different probe molecules such as water, n-hexane, cyclohexane, m-xylene and 1,3,5-trimethylbenzene (mesitylene) was measured at 298 K. Considerable sorption (> 7.5 wt%) of bulky molecules such as m-xylene and mesitylene was observed suggesting the possible access from the crystal surface to some 12 membered-ring cages. The sorption energetics in zeolite MCM-22 as a function of the framework SiO2/Al2O3 ratio were discussed on the basis of NH3 sorption isotherms in the temperature range 303–453 K. The sorption data were analysed in terms of different sorption isotherm equation models. The ammonia sorption studies indicated that the acid sites were not uniform and were distributed heterogeneously.
Adults recognize toddlers’ song renditions
Authors: Gudmundsdottir Helga , Trehub Sandra
Published: July 2017

The present study explored the singing ability of toddlers 16 months to 3 years of age by examining North American adults’ ability to identify toddlers’ renditions of familiar tunes sung with foreign lyrics. After listening to each toddler’s song, half with familiar melodies and half with unfamiliar melodies, adults attempted to name the songs. Their identification was highly accurate, refuting the prevailing view that toddlers focus on words at the expense of tunes. The singing range of these non-English-speaking toddlers and that of their English-speaking counterparts approximated the pitch range of the target songs, which is inconsistent with the reportedly small singing range of toddlers. Toddlers’ apparent singing proficiency in the present context may stem from the use of home-based recordings and child-selected songs.
Race, Trust in Government, and Self-Employment
Authors: Price Gregory N.
Published: July 2017

This paper examines the effects of trust in government on the self-employment decision. For black Americans the decision to be self-employed, and the associated returns are likely to be particularly sensitive to trust in the federal government, as the history and political economy of race in the United States required federal government to introduce laws, legislation and institutions to alter the future behavior of whites in their market interactions with blacks. Utilizing General Social Survey Data, I find that among the self-employed, race—being black—is a negative determinant of various measures of trust and confidence in federal government. Parameter estimates from a Bivariate Probit estimator of the likelihood of black self-employment and income reveal that both increase with respect to several measures of trust and confidence in the federal government. The results suggest that as the relative growth and performance of black self-employment is trust and confidence sensitive, the underrepresentation of black-owned firms can possibly be explained by the relatively low trust and confidence in the federal government among black Americans.
Fibre Waviness Generation and Measurement and Its Effect on Compressive Strength
Authors: Wisnom Michael R. , Atkinson J. W.
Published: July 2017

Artificial fibre waviness was produced by laying up unidirectional carbon fibre-epoxy on a curved plate, and then straightening it before curing. A technique was developed for measuring out-of-plane waviness using a surface displacement transducer mounted on a traversing table. Measurements within the laminate were made by splitting it open along ply interfaces treated with release agent prior to curing. Typical maximum misalignment angles at the centre of a 2 mm thick panel were in the range 0.7 to 1 degree. In-plane waviness data was also generated by splitting the plies along the fibre direction. Tests in a pin-ended buckling rig gave compressive failures with reductions of compressive and tensile surface strain of only 17% and 26%, despite in-plane misalignments of up to 24 degrees in the surface plies.
Effect of Loading Path on Mechanical Response of a Glass Fabric Composite at Low Cyclic Fatigue under Tension/Torsion Biaxial Loading
Authors: Inoue Atsushi , Fujii Toru , Kawakami Hiroshi
Published: July 2017

The present paper shows how loading path affects the low cyclic fatigue failure of a glass fabric/vinylester resin composite. The focus is placed on the stress-strain response both in tension and shear as well as on the fatigue life under tension/torsion biaxial loading at low cycle fatigue up to 10,000 cycles. Three types of loading paths were applied: Type I-Biaxial loads were applied proportionally to the specimens. Namely the resultant stresses, tensile and shear stresses increased simultaneously. Type II-A tensile load was first applied. Then, a torsion moment was applied to attain a (biaxial stress ratio) = 3/1 while the tensile load was kept constant. The applied loads were removed in the reverse order. Type Il I-Contrary to Type II loading, first a torsion moment was applied. Then, a tensile load was applied to attain a L = 3/1 while the torsional moment was kept constant. The maximum stress states in the laminate during each loading period are the same for all loading cases. The experimental results revealed that: (1) No significant effect of loading path on the fatigue life exists. (2) The modulus decay in shear with respect to the number of loading cycles is affected by loading path while the modulus decay in tension was not significantly affected. (3) There exist peculiar responses in stress-strain relations both in tension and shear when loading path is changed although the final strain state is almost the same in all loading cases as long as the internal damage is not much accumulated. A model for explaining the peculiar stress-strain behaviors was proposed based on the Continuum Damage Mechanics (CDM) in conjunction with the lamination theory. The calculated stress-strain responses reasonably agree with the experimental stress-strain behaviors under biaxial loadings having different loading paths.
The Analysis of Warpage for Integrated Circuit Devices
Authors: Jong Wen-Ren , Chang Ming-Lun
Published: July 2017

This paper deals with thin elongated packaging for large size silicon chips and its warpage caused by temperature changes during the packaging process. An integrated circuit device is composed of several materials with different properties of which differences in the thermal expansion coefficients of the materials pose the largest influence on the resulting product. In the course of IC encapsulation, as the product goes through numerous processes, temperatures will rise and fall and cause the composing materials to experience repeated thermal expansion and shrinkage. Since the material layers are under perfect adhesion, any two neighboring materials with different thermal expansion coefficients will be stressed from the temperature change causing the product to deform.

Current IC warpage analytical model research is based mainly on Dr. Suhir's theory of the compatibility conditions for the interfacial strains. The analytical model in Dr. Suhir's theory is constructed upon four layers of two-dimensional materials. There are two sections in the model: one is the section comprising the silicon chip and one is the section without the silicon chip. The latter section is only roughly simulated with a single homogenous material and is unable to correctly simulate the geometric shape of an actual encapsulation component. This paper extends Dr. Suhir's analytical model to possessing unlimited layers and consisting of many sections. Thus, it not only increases the completeness and correctness of the analysis results but also resolves the problem of accommodating models with different geometric shapes.
Separating Sources of Manufacturing Distortion in Laminated Composites
Authors: Radford D. W. , Rennick T. S.
Published: July 2017

Manufacturing distortion in composites has been a problem for many years and continues to impede the development of composite materials. Previous efforts have shown these manufacturing distortions to be related to differences in the in-plane and through-thickness properties. Often tooling is modified in an attempt to compensate for these fabrication induced distortions; however, the various sources of the problem have not been clearly identified, measured, nor accepted. Earlier efforts have suggested that both the cooldown from process temperature and shrinkage during cure play a role, yet no single work has measured the relative contributions of these effects. Further, researchers have suggested numerous other factors as being responsible for all, or some portion, of the measured distortion. In this work, distortion in autoclave-cured laminated composites has been experimentally measured, at temperatures ranging from 240C to 1780C, to determine the reversible and irreversible contributions to manufacturing warpage and to attempt to separate the distortion into components related to different mechanisms. Three mechanisms, anisotropy, material property gradients, and stress gradients are described, and are further separated into thermoelastic and non-thermoelastic components. The measured reversible response closely matches computed distortion, based solely on the in-plane and through-thickness coefficients of thermal expansion. Further, it seems that the irreversible contributions can be separated into material dependent effects, such as cure shrinkage, and process related effects, such as part/tool interactions. Calculations, based on anisotropy, indicate that both temperature change and cure shrinkage contribute significantly to manufacturing distortion; but, their contribution does not account for the total distortion. The irreversible contribution is much greater than predicted, indicating the action of a mechanism which only involves a non-thermoelastic contribution, such as a part/tool interaction. Trends in the experimentally observed distortion indicate the presence of other non-thermoelastic process related contributions and show that these other contributions seem to diminish as the thickness, corner radius and included angle increase.
Unified Micromechanical Model for Estimating Elastic, Elasto-Plastic and Strength Behaviors of Knitted Fabric Reinforced Composites
Authors: Huang Zheng Ming , Ramakrishna S. , Tay A. A. O.
Published: July 2017

This work presents a unified micromechanical model for estimating the three-dimensional elastic, elasto-plastic, and strength properties of a plain weft knitted fabric reinforced composite. A bridging matrix is used to correlate the stresses generated in fiber and matrix phases in a representative volume element (RVE) of the composite. With this bridging matrix, the stress in each constituent phase is explicitly expressed as a function of the overall applied stress and all the mechanical properties of the composite are easily derived from the knowledge of the physical and geometric properties of the constituents. The total stress-strain behavior of the composite is obtained based on the stress-strain behaviors of the constituent materials. The composite strength is then defined as the overall applied stress corresponding to which the maximum normal stress in either the fiber or the matrix attains its ultimate value. Good correlation between theoretical and experimental results has been found.
A Study of Flexural Behavior of Reinforced Concrete Beam Strengthened with Carbon Fiber-Reinforced Plastic (CFRP)
Authors: Ng S. C. , Lee S.
Published: July 2017

This paper presents an analytical study on the flexural behavior of reinforced concrete beams strengthened with externally bonded carbon fiber-reinforced plastic (CFRP) laminates. Different failure modes of these strengthened reinforced beams have been reported and these failure modes are generally referred to as brittle failure or ductile failure involving the compression crushing of the concrete, debonding or rupture of the composite laminate and yielding of the steel reinforcement. For the analysis, the stresses and strains of all the components of the beam are related by the material properties, including the stress-strain curves for the concrete, steel and CFRP laminate. The strain distribution is assumed to be compatible within the distorted shape of the cross-section of the concrete beam. The resultant forces on the cross section are balanced with the applied loads for static equilibrium. The analytical solution is derived from the equilibrium equations and the compatibility of the strains, and it is applicable to both singly and doubly reinforced concrete beams strengthened with multi-layers of CFRP laminates. In this study, a simple and direct analytical procedure has been developed to evaluate the flexural capacity of concrete beams strengthened with CFRP and to predict their failure modes. An example is presented to illustrate the computational procedures. For design purposes, the upper and lower limits of CFRP cross-section areas are established to ensure that reinforced concrete beam strengthened with advanced composite materials will fail in a ductile manner. A comparison between the analytical results and the data obtained from the literature has been made and the agreement is very good.
Modifying Stacking Sequence Design to Delay Delamination and Matrix Cracking in Laminated CompositesThe Multi-Delamination-Interface Design
Authors: Xu Luo-Yu
Published: July 2017

A simple principle of stacking sequence design is presented. The multidelamination-interface design suggests that more possible delamination interfaces between the 0/90 plies should be designed, i.e., the 900 plies are better to be separated, the thickness of the 900 plies is reduced to one ply. Results show that for the symmetric balanced laminate, matrix crack can be suppressed in the CFRP laminate and delayed in the GFRP laminate, and edge delamination will be delayed in the laminate under the static inplane loading. This method stems from the approximate analysis in which the principles of the Linear Elastic Fracture Mechanics are employed. It is also verified by the delamination moment analysis. These results are expected to be extended to the laminate subjected to the impact loading.
Fatigue Life Prediction of Composite Laminates Using a Stress Redistribution Function
Authors: Diao Xiaoxue , Ye Lin , Mai Yiu-Wing
Published: July 2017

Within the framework of a statistical model and using the concept of a representative volume for damage evolution, a new way of determining the stress redistribution function to predict residual strength and fatigue life of a composite laminate was developed in terms of the fatigue behaviour of its laminae. The residual strength distribution function and the failure probability of composite laminates were derived. Knowing the degradation behaviour of residual strength for the property profile associated with the critical element, the static strength distribution and a stress redistribution function evaluated from the model of stiffness reduction of the composite laminate, the fatigue life of composite laminates can be determined from the failure probability. Comparison with experimental data for the glass/epoxy unidirectional, [- 45,02]s and [45,%]s laminates shows good agreements with the theoretical predicted values.
Characterisation of Low Energy Impact Damages in Composites
Authors: Gros Xavier E.
Published: July 2017

A non-destructive examination technique using an electromagnetic testing method has been developed for the inspection of reinforced carbon fibre materials. Damage detection was performed on a total of 53 low energy impacts (from 0.5 to 10 Joules) which were induced in realistic samples supplied by the aerospace industry. The eddy-current technique employed was proven very accurate and inherently reproducible in the detection of low energy impact damages in carbon reinforced materials. These damages were below the detection threshold of other conventional NDT methods such as ultrasonic, infrared thermography and radiography. A statistical analysis, making use of probability of detection curves (POD) and receiver operating characteristic curves (ROC) has been performed in order to evaluate the performance of different inspection systems. Computer visualisation facilities were used to locate and quantify impacts on carbon materials. The technique was also proven very efficient to assess the structural integrity of CFRP and GFRP helicopter rotor blades. If correctly applied, eddy current inspection will certainly enhance the quality and efficiency of non-destructive examinations and improve the level of quality and safety required by the aerospace industry.
On Residual Stress Induced Distortions during Fabrication of Composite Shells
Authors: Jain Lalit K. , Mai Yiu-Wing
Published: July 2017

Channel or angle components are important structural members. It has been observed that during the manufacture of these components, residual stresses build up. The state of residual stress in these components leads to a reduction in the enclosed angle where the out-of-plane contraction is higher than the in-plane contraction. This phenomenon (of the reduction in the enclosed angle) is referred to as spring-in. The residual stresses, in addition, may lead to defects such as micro-cracking, delamination, etc. The degree of spring-in and the residual stresses may be estimated by analysing the curved portions of these structural components as sectors of circular cylindrical tubes (see Figure 1). In this paper, a simple mechanics-based model is developed using modified shell theory that predicts the degree of spring-in and determines the stresses and strains in cylindrical segments with arbitrary lay-ups subjected to random temperature gradients. The model accounts for the resin shrinkage occurring during curing and also includes the effect of moisture gradients. The accuracy of the present analysis is investigated by comparing predicted results with previously published results.
An Assessment of Failure Criteria to Predict the Strength of Adhesively Bonded Composite Double Lap Joints
Authors: Tong L.
Published: July 2017

Interlaminar delamination within the surface ply of a composite adherend adjacent to adhesive layer is a typical failure mode for adhesively bonded composite lap joints. To characterise interlaminar delamination, new failure criteria were proposed and then compared with other failure criteria developed previously. These failure criteria were then utilised in the simplified one-dimensional and finite element analysis procedures to predict strength for adhesively bonded composite double lap joint specimens. It was shown that there was a good correlation between the measured failure loads and those predicted using nonlinear adhesive material properties.
Transverse Cracking of Composite Laminates with Interleaves: A Variational Approach
Authors: Gillespie John W. , Hansen Ulrich
Published: July 2017

A two-dimensional shear-lag analysis predicting the effect of interlayers on transverse cracking is developed. The orthotropic nature of the material, as well as crack interactions are incorporated, and a Griffith's type fracture criterion is used to predict the transverse crack failure. The obtained stress solution satisfies the traction-free crack surface boundary conditions. The analysis results are compared to experimental data of a well characterized model material, and parametric studies identifying key parameters in mechanical behavior of interlayered composites are presented.
Vibration Analysis of Stiffened Laminated Plates Including Thermally Postbuckled Deflection Effect
Authors: Lee Dong-Min , Lee In
Published: July 2017

Vibration characteristics of stiffened laminated plates are investigated considering postbuckled deflection effect due to thermal load. The finite element method is used for the analysis of thermal postbuckling and natural vibration of stiffened plates in the postbuckling range. The finite element model is based on the first order shear deformable plate theory (FSDT) for a skin panel and Timoshenko beam theory for stiffeners. Von Karman strain-displacement relation is used to account for a large deflection. Critical buckling temperature and the corresponding mode shape are determined from Euler buckling problem. In order to solve the thermal-postbuckling problem, the initial nonlinear stiffness is determined from an estimated deflection of scaled buckling mode shape. The converged deflection at any temperature change is obtained using the Newton-Raphson method. The vibration analyses of stiffened laminated plates in the postbuckling range are performed using the tangent stiffness obtained from the converged deflection. The effects of the stiffener size, the number of stiffeners, and lamination scheme on vibration characteristics are studied for stiffened laminated plates subject to steady-state uniform temperature increase.
A Study on Permeability of Unidirectional Fiber Beds
Authors: Um M. K. , Lee W. I.
Published: July 2017

Permeability crucial to resin flow was studied. Approximate solutions of Kozeny constant for regularly packed beds were developed for square and triangular cells in parallel and perpendicular flows. Network system models for fiber beds which are irregularly packed were proposed. Validity of the models was checked through the experiments. Image processing technique was applied to find centers of fibers. Prediction of permeability is done by the application of network models using the centers of fibers. In two flow types, good agreement was found between experiments and predictions by the network models. Permeability of fiber beds can be directly calculated by suggested models using the images.
Finite Element Coupled Slosh Analysis of Rectangular Liquid Filled Laminated Composite Tanks
Authors: Pal N. C. , Sinha P. K. , Bhattacharyya S. K.
Published: July 2017

This paper presents the sloshing response and coupled dynamic behaviour of rectangular liquid filled laminated composite tanks under harmonic base excitation. For the numerical simulation of the problem, the finite element method is used to develop an integrated computational scheme in 3-D, which accounts for the coupling effect between liquid sloshing and the tank vibration. Dynamic responses are computed in the time domain using Newmark's predictor-multicorrector-algorithm. Both fluid transients and structural dynamics problems are dealt with separately before solving the coupled slosh problems. A computer code is developed which generates numerical data for the slosh frequency, sloshing displacement, free surface profiles, hydrodynamic pressure, deformed structural modes and the container response due to the change in the hydrodynamic pressure. The solution procedures are applied to both rigid and flexible containers to demonstrate the effect of tank flexibility on the overall slosh phenomenon and structural response. The effects of lamination scheme, free surface wave and decoupled analysis approach on the tank wall response are also investigated. To the best knowledge of the authors, the results of similar cases involving the interaction of fluid with laminated composite tanks, are not available in the open literature.
Influence of the Mode Mix of Precracking on the Delamination Toughness of Laminated Composites
Authors: Davidson Barry D. , Koudela Kevin L.
Published: July 2017

A study is described that evaluated the effect of the mode mix used to create a precrack on the perceived delamination toughness of laminated composites. Mode I double cantilever beam, mode II end-notched flexure, and mixed-mode symmetrically delaminated single leg bending tests were first performed on unidirectional graphite/epoxy specimens with mode I precracks. The tests were then repeated on new unidirectional specimens with mode II precracks. Through an examination of the mechanisms involved, it is shown that toughness values for materials that do not exhibit fiber bridging will be most accurate, at all mode mixities, if test specimens are precracked at the same mode mix as the test itself.
Finite Element Analysis of Transverse Cracking Behaviour in Hybrid Angle-Ply Composite Laminates
Authors: Pradhan B. , Kumar N. Venu , Rao N. S.
Published: July 2017

The authors previously presented a 3D finite element method for calculating strain energy release rate and stiffness reduction in transversely cracked cross-ply hybrid laminates. The procedure is based on the computation of strain energy in the laminates with simulated crack and their incremental extensions for applied strains. In the present paper 3D FE method is further extended to study the crack behaviour in hybrid angle-ply laminates under constant applied strain. Variations of strain energy release rate and stiffness reduction with fibre orientation angle 0 of outer GR/E layers for different GR/E-GL/E hybrid angle-ply laminates have been calculated. The effects of different geometrical parameters on the crack extension behaviour in width direction have been studied. Variation of strain energy release rate and stiffness reduction in cracked hybrid angle-ply laminates depend not only on the fibre orientation angle 0 of the outer GE/E layers but also on the material properties and number of cracked and uncracked layers in the laminate.
The New Black Book: What Does It Tell Us About Adult Education?
Authors: Chené Adèle
Published: July 2017

Peters, J., Jarvis, P., and Associates. (1991). Adult Education: Evolution and Achievements in a Developing Field of Study. San Francisco: Jossey-Bass.
Child Neurology Training via the Research Pathway: Outcome Study
Authors: Percy Alan K. , Juul Dorthea , Scheiber Stephen C.
Published: July 2017

This article describes a residency training track that was developed by the American Board of Psychiatry and Neurology to promote the career development of child neurologists who wanted to become researchers. In this pathway, 1 year of research in the basic neurosciences replaces 1 year of pediatrics or internal medicine. Since 1992, 38 residents from more than 20 training programs have been accepted into this pathway. Of the 28 who have completed residency training, 22 are in academic positions as faculty or fellows, and 6 are working in nonacademic hospital settings. Of these 22, 6 describe their research as basic, and 12 describe their research as being both basic and clinical; 15 have been successful in obtaining external funding. Thus far, these trainees have published more than 125 articles in peer-reviewed journals. Although small in scope, this training track has met its objective of producing clinician-scientists. ( J Child Neurol 2004;19:142—144).
Antenatal Diagnosis of Central Nervous System Anomalies: Can We Predict Prognosis?
Authors: Leitner Yael , Goez Helli , Gull Ilan , Mesterman Ronit , Weiner Ehud , Jaffa Ariel , Harel Shaul
Published: July 2017

Our technical ability to diagnose fetal anomalies of the central nervous system by ultrasonography and by fetal magnetic resonance imaging far exceeds our current knowledge of their possible neurodevelopmental implications later in life. This limitation often makes obstetric and clinical decisions very difficult. We retrospectively reviewed the ultrasonographic records of 6220 women who had been followed up at two large medical centers between 1994 and 1999. One hundred and sixty (2.6%) women had abnormal fetal central nervous system findings. The neurodevelopmental outcome of these children was assessed by a telephone interview with the parents. Small cerebellar size was the most frequent anomaly, followed by isolated mild ventriculomegaly and isolated choroid plexus pathology. Suboptimal neurodevelopmental outcome was found in 24% of children with isolated ventriculomegaly and in 9% with choroid plexus pathology. In the group of children with a "small cerebellum," suboptimal neurodevelopment was found in 19%. The measurement of transcerebellar diameter in respect to its developmental implication is, to our knowledge, described here for the first time. We believe that cerebellar measurements and their possible neurocognitive implications should be an integral part of future studies. ( J Child Neurol 2004;19:435-438).
Pediatric Epstein-Barr Virus—Associated Encephalitis: 10-Year Review
Authors: Doja Asif , Bitnun Ari , Ford Jones Elizabeth Lee , Richardson Susan , Tellier Raymond , Petric Martin , Heurter Helen , MacGregor Daune
Published: July 2017

Many neurologic manifestations of Epstein-Barr virus (EBV) infection have been documented, including encephalitis, aseptic meningitis, transverse myelitis, and Guillain-Barré syndrome. These manifestations can occur alone or coincidentally with the clinical picture of infectious mononucleosis. Since 1994, The Hospital for Sick Children has maintained a prospective registry of all children admitted with acute encephalitis. This report summarizes all cases of Epstein-Barr virus—associated encephalitis compiled from 1994 to 2003. Twenty-one (6%) of 216 children, median age 13 years (range 3—17 years), in the Encephalitis Registry were identified as having evidence of Epstein-Barr virus infection. This evidence consisted of convincing Epstein-Barr virus serology and/or positive cerebrospinal fluid polymerase chain reaction (PCR). One patient had symptoms of classic infectious mononucleosis; all others had a nonspecific prodrome, including fever ( n = 17; 81%) and headache ( n = 14; 66%). Slightly less than half ( n = 10; 48%) had seizures and often had electroencephalograms showing a slow background ( n = 12; 57%). Many demonstrated cerebrospinal fluid pleocytosis ( n = 17; 81%), and 71% ( n = 15) had abnormal magnetic resonance imaging findings. Two patients died, 2 suffered mild deficits, and 16 were neurologically normal at follow-up. Most patients with Epstein-Barr virus encephalitis do not show typical symptoms of infectious mononucleosis. Establishing a diagnosis of Epstein-Barr virus encephalitis can be difficult, and, consequently, a combination of serologic and molecular techniques should be used when investigating a child with acute encephalitis. Most children make full recoveries, but residual neurologic sequelae and even death can and do occur. ( J Child Neurol2006;21:384—391; DOI 10.2310/7010.2006.00114).
Treatment of Anticonvulsant Hypersensitivity Syndrome with Intravenous Immunoglobulins and Corticosteroids
Authors: Prais Dario , Straussberg Rachel , Amir Jacob , Nussinovitch Moshe , Harel Liora
Published: July 2017

Anticonvulsant hypersensitivity syndrome is a specific severe idiosyncratic reaction to the aromatic antiepileptic drugs. The most frequent presenting symptoms are fever and rash, lymphadenopathy owing to lymphoid hyperplasia, hepatitis, and interstitial nephritis. Severe skin reactions (Stevens-Johnson syndrome or toxic epidermal necrolysis) have also been reported. Early detection is crucial owing to the high mortality rate. Although withdrawal of the offending drug is critical, the optimal treatment approach remains controversial. Previous studies report a severe course and prolonged hospital stay for cutaneous drug-related reactions, including referral to a burn center, skin débridement, and allograft skin coverage. The aim of the present report is to describe four adolescents with antiepileptic drug hypersensitivity syndrome who were treated with intravenous immunoglobulin and systemic corticosteroids. All recovered completely following an uncomplicated and relatively short course and hospitalization. Findings indicate that this regimen might be a promising treatment option in this patient population. Larger, controlled trials are needed to reach a definitive conclusion. ( J Child Neurol 2006;21:380—384; DOI 10.2310/7010.2006.00122).
Comparison of the dynamical behaviour of rectangular natural circulation loops
Authors: Fichera A , Froghieri M , Pagano A
Published: July 2017

This paper presents a comparison of the dynamical behaviours manifested by two singlephase experimental natural circulation loops. Both of the loops are rectangular and symmetric, with a heat source and a heat sink placed respectively at the bottom and at the top of the loop. The main differences between the two loops are their height and width, the inner diameter of their pipes and the length of the heating and cooling sections. In order to emphasize the differences in the dynamical evolution, the comparison was performed considering the same operating conditions. A phase space representation was chosen, so as to guarantee an adequate representation of the complex non-linear process dynamics. The proposed analysis, which is based on the morphological description of the attractors and on the evaluation of their correlation dimension, aims to give a preliminary characterization of the behaviours of the natural circulation loops under comparison. The proposed approach allowed it to be demonstrated that the differences of geometry lead to substantial changes in the dynamics that the two experimental loops may manifest for the same operating condition, defined by the heat power supplied to the fluid. In particular, reported results show that for some values of the heat power one of the experimental loops displays periodic oscillations whereas the other is governed by chaos.
Coupled thermomechanical simulation of the polymer die drawing process
Authors: Mirza M S , Taraiya A K , Ward I M , Barton D C
Published: July 2017

An analysis of the polymer die drawing process using full thermomechanically coupled finite element (FE) modelling is described. Strain rate and temperature dependent stress—strain data for polyoxymethylene (POM) have been obtained from uniaxial tensile tests and utilized in the numerical simulations. The FE model has been validated against die drawing experiments, and both refute the previously held assumption that ‘free’ drawing commences within the die as a result of separation of the polymer from the die wall prior to exit. Simulations have been employed using the fully validated model to study the influence of process parameters such as die half-angle, area reduction, die wall friction and drawing speed on the draw loads and the amount of free tensile drawing that takes place outside the die.
When Harold huffed and puffed
Authors: Proops Marje
Published: July 2017

Everyjournalist has at least one - probably haff a dozen - memorable pieces; something tucked away on the mental shelf that he, or she, is quietly, even secretly, proud of... or possibly embarrassed by. Marje Proops takes the first plunge with ...
An assessment of two gastric transport models currently used in safety pharmacology testing
Authors: Baldrick P , Bamford D G , Tattersall M L
Published: July 2017

1 The potential effects of new drugs on the digestive system can be examined in a number of model systems of which intestinal motility in the mouse and/or gastric emptying in the rat are examples recommended for safety pharmacology evaluation.

2 Intestinal motility, assessed by the transit of carmine dye in the mouse and gastric motility, assessed by stomach weight in the rat, were examined using a range of clinical drugs or potent pharmacological agents known to affect gastrointestinal function. Assessment of both models in the guinea-pig was also evaluated.

3 Activity was demonstrated with codeine, diazepam, atropine and CCK-8 (all of which inhibited gastric function). However, neither model gave consistent and reliable results with the remaining reference compounds, namely metoclopramide, bethanechol, cisa-pride, deoxycholate, carbachol and domperidone.

4 In conclusion, this investigation questions the usefulness of simple models of gastrointestinal transport in the rodent as a means of detecting potential effects of a new drug on the digestive system. This finding should be of concern to the pharmaceutical industry as these simple models are routinely used as part of a regulatory safety pharmacology `package' of studies.
Analysis of dichotomous outcome data for community intervention studies
Authors: Bellamy Scarlett L , Gibberd Robert , Hancock Lynne , Howley Peter , Kennedy Bruce , Klar Neil , Lipsitz Stuart , Ryan Louise
Published: July 2017

Community intervention trials are becoming increasingly popular as a tool for evaluating the effectiveness of health education and intervention strategies. Typically, units such as households, schools, towns, counties, are randomized to receive either intervention or control, then outcomes are measured on individuals within each of the units of randomization. It is well recognized that the design and analysis of such studies must account for the clustering of subjects within the units of randomization. Furthermore, there are usually both subject level and cluster level covariates that must be considered in the modelling process. While suitable methods are available for continuous outcomes, data analysis is more complicated when dichotomous outcomes are measured on each subject. This paper will compare and contrast several of the available methods that can be applied in such settings, including random effects models, generalized estimating equations and methods based on the calculation of `design effects', as implemented in the computer package SUDAAN. For completeness, the paper will also compare these methods of analysis with more simplistic approaches based on the summary statistics. All the methods will be applied to a case study based on an adolescent anti-smoking intervention in Australia. The paper concludes with some general discussion and recommendations for routine design and analysis.
Family-based association studies
Authors: Zhao Hongyu
Published: July 2017

Over the past decade, attention has turned from positional cloning of Mendelian disease genes to the dissection of complex diseases. Both theoretical and empirical studies have shown that traditional linkage studies may be inferior in power compared to studies that directly utilize allele status. Case-control association studies, as an alternative, are subject to bias due to population stratification. As a compromise between linkage studies and case-control studies, family-based association designs have received great attention recently due to their potentially higher power to identify complex disease genes and their robustness in the presence of population substructure. In this review, we first describe the basic family-based association design involving one affected offspring with its two parents, all genotyped for a biallelic genetic marker. Extensions of the original transmission disequilibrium tests to multiallelic markers, families with multiple siblings, families with incomplete parental genotypes, and general pedigree structures are discussed. Further developments of statistical methods to study quantitative traits, to analyse genes on the X chromosome, to incorporate multiple tightly linked markers, to identify imprinting genes, and to detect gene-environment interactions are also reviewed. Finally, we discuss the implications of the completion of the Human Genome Project and the identification of hundreds of thousands of genetic polymorphisms on employing family-based association designs to search for complex disease genes.
Progesterone Sharpens Temporal Response Profiles of Sensory Cortical Neurons in Animals Exposed to Traumatic Brain Injury
Authors: Allitt Benjamin J. , Johnstone Victoria P. A. , Richards Katrina L. , Yan Edwin B. , Rajan Ramesh
Published: July 2017

Traumatic brain injury (TBI) initiates a cascade of pathophysiological changes that are both complex and difficult to treat. Progesterone (P4) is a neuroprotective treatment option that has shown excellent preclinical benefits in the treatment of TBI, but these benefits have not translated well in the clinic. We have previously shown that P4 exacerbates the already hypoactive upper cortical responses in the short-term post-TBI and does not reduce upper cortical hyperactivity in the long term, and we concluded that there is no tangible benefit to sensory cortex firing strength. Here we examined the effects of P4 treatment on temporal coding resolution in the rodent sensory cortex in both the short term (4 d) and long term (8 wk) following impact-acceleration–induced TBI. We show that in the short-term postinjury, TBI has no effect on sensory cortex temporal resolution and that P4 also sharpens the response profile in all cortical layers in the uninjured brain and all layers other than layer 2 (L2) in the injured brain. In the long term, TBI broadens the response profile in all cortical layers despite firing rate hyperactivity being localized to upper cortical layers and P4 sharpens the response profile in TBI animals in all layers other than L2 and has no long-term effect in the sham brain. These results indicate that P4 has long-term effects on sensory coding that may translate to beneficial perceptual outcomes. The effects seen here, combined with previous beneficial preclinical data, emphasize that P4 is still a potential treatment option in ameliorating TBI-induced disorders.
Suppression of Trim32 Enhances Motor Function Repair after Traumatic Brain Injury Associated with Antiapoptosis
Authors: Zhang Zi-Bin , Xiong Liu-Lin , Lu Bin-Tuan , Zhang Hui-Xiang , Zhang Piao , Wang Ting-Hua
Published: July 2017

To investigate the role of Trim32 in traumatic brain injury (TBI), adult male Sprague Dawley (SD) rats and mice were randomly divided into sham (n = 6) and TBI groups ( n = 24), respectively. Then, mice were assigned into Trim32 knockout mice (Trim32-KO [+/−]) and wild-type (WT) littermates. The TBI model used was the Feeney free-falling model, and neurological function was evaluated after TBI using a neurological severity score (NSS). Reverse transcription polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry were used to investigate the expression of Trim32 in the damaged cortex. Cell apoptosis in the cortex was detected by terminal-deoxynucleoitidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Moreover, Trim32-KO (+/−) mice were used to determine the effect of Trim in neurological repair after TBI. Results showed the NSS scores in TBI rats were significantly increased from day 1 to day 11 postoperation, compared with the sham group. Trim32 messenger RNA (mRNA) expression in the cortex was significantly increased at 7 d after TBI, while the level of Tnr and cytochrome c oxidase polypeptide 5A mRNA didn’t exhibit significant changes. In addition, Western blot was used to detect the level of Trim32 protein in the cortex. Trim32 expression was significantly increased at 7 d after TBI, and immunoreactive Trim32-positive cells were mainly neurons. Moreover, Trim32-KO (+/−) mice with TBI had lower NSS scores than those in the WT group from day 1 to day 11 postoperation. Meanwhile, Trim32-KO (+/−) mice had a decreased number of TUNEL-positive cells compared with the control group at 3 d postoperation. Protein 73 (p73) decreased at 7 d postoperation in Trim32-KO (+/−) mice with TBI, when compared with WT mice with TBI. Our study is the first to confirm that suppression of Trim32 promotes the recovery of neurological function after TBI and to demonstrate that the underlying mechanism is associated with antiapoptosis, which may be associated with p73.