bluuebunny/crossref_metadata_2025 huggingface dataset:
Training of Technical Staff for Nuclear Power Station Operation
Authors: Haire T P , Myerscough P B
Published: October 2007

The paper discusses the statutory training requirements covering the technical staff in the CEGB (Central Electricity Generating Board). Details of the training programmes emphasize the importance of the staff having a thorough understanding of the nuclear processes involved in the station operation and not relying solely upon a mechanistic approach to operating procedures. The paper also examines the impact of this philosophy on the design of training simulators and makes a brief comparison with the training philosophies in other countries.
Performance Characteristics of a Horizontal Axis Model Wind Turbine
Authors: Sayers A T , Bsc A F Christopher
Published: October 2007

The performance characteristics of wind turbines should be thoroughly investigated prior to expending large amounts of capital on a prototype design. A low power dynamometer is described for measuring the power and torque output from a two-bladed model wind turbine, and performance characteristics relating coefficient of performance to tip speed ratio and blade geometric pitch are presented for three designs of blade.
Measurement of Wear of Twist Drills
Authors: Amini E , Winterton R H S
Published: October 2007

The results of a number of wear tests using the new surface activation technique are described. The technique itself has been refined to allow greater sensitivity and a quantitative interpretation of the results in terms of an equivalent linear wear. Calibration curves of wear against loss of radioactivity have been obtained both directly by grinding and indirectly by prediction from a separate measurement of activity as a function of depth. Agreement between optical and surface activation measurements is good. The sensitivity of the surface activation technique has been exploited to obtain new results for the very early stages of flank wear.
Pendair—A Proposed Lower Cost Rapid Transit System Compatible with the Urban Environment
Authors: Bliss D S
Published: October 2007

Increasing traffic congestion and the possible oil shortages make it desirable to introduce segregated electrically driven rapid transit on a much wider scale than is likely to be achieved by the conventional underground metropolitan railway. The characteristics of rapid transit are examined. It is concluded that new techniques should be developed to supplement existing methods by exploiting the overhead solution to the problem of restricted ground space in urban areas. The Pendair mass transit system is based on a suction air suspension and a concrete beam track. Their favourable interaction leads to a relatively low cost system with some desirable performance, safety and environmental features which are described.
A Full Shift True Breathing Zone Air Sampler and Its Application to Lead Workers
Authors: Allen J , Bellinger E G , Higgins R I
Published: October 2007

A completely head-mounted full shift dust sampler for monitoring the lead-in-air concentration in a lead worker's actual breathing zone is described. A small filter head is positioned within 5 cm of the mouth and nose on an adjustable stalk. Air is drawn through a 1.25 cm diameter glass fibre filter at a rate of 0.51/min by a small rotary vane pump.

Initial comparisons with a conventional lapel-mounted UKAEA head powered by a Casella pump show that the average lead-in air concentration in the true breathing zone can be significantly different from that around the lapel.
Plastic Buckling of Torispherical and Ellipsoidal Shells Subjected to Internal Pressure
Authors: Galletly G D
Published: October 2007

Thin metallic torispherical shells are used frequently in many industries as end closures on cylinders subjected to internal pressure and, for those torispheres which have diameter/thickness ratios greater than 400, elastic-plastic internal pressure buckling may occur. As yet, however, code rules to assist the designer with this buckling problem are not available in either the UK or the USA and one of the aims of this paper is to help to correct this situation.

Elastic-plastic internal buckling pressures, for a range of perfect torispherical geometries and obtained with the aid of a sophisticated computer program, are given in the first part of the paper. These pcr's are then utilized (a) to develop a relatively simple equation for predicting the internal buckling pressures of torispherical shells and (b) to assess the accuracy of another, even simpler, approximate buckling equation which was suggested recently (1).

Next, the correlation between the theoretical predictions of pcr and the experimental results is considered. The tests taken into account were (a) 5 in diameter machined model torispherical shells, (b) 20 in diameter spun ellipsoidal shells, and (c) 54 in diameter pressed and spun torispherical shells. The shells in (b) and (c) were not stress-relieved and a number of them were made from strain-hardening materials. The agreement between theory and experiment was good for the machined models and fairly satisfactory for the spun models. For the ellipsoidal shells there was also reasonably good agreement between the predictions of two simple design equations and the experimental results.

The problems associated with the prediction of the internal buckling pressures of spun torispherical shells made from strain-hardening materials (e.g. stainless steel) are considered in the last section of the paper. Taking the results of the previous sections of the paper into account, and making some simplifying assumptions, a tentative design procedure for predicting the pcr's of these ‘as-manufactured’ spun torispherical shells is proposed. This procedure is then checked by comparing its predictions with experimental buckling pressures found for eleven spun stainless steel heads and six crown and segment ones. The agreement between experiment and theory was quite satisfactory and it is hoped that the suggested procedure might become the first step towards the development of experimentally validated code rules for preventing the occurrence of buckling in these dished ends.
Studies on a Unit Injector for Cars with High-Speed Engines
Authors: Herzog P
Published: October 2007

The development of modern diesel engines is moving towards increased power per unit of displacement, lower engine weight, wider speed range, better fuel economy and lower noise and pollution levels. Due to these trends Friedmann and Maier have developed a new injection system, the unit injector, (Figs 1 and 2). This paper deals with the development of the unit injector, its special features and its advantages and disadvantages in comparison with conventional in-line pumps.
The Development of the Prototype Advanced Passenger Train
Authors: Boocock D , King B L
Published: October 2007

The development and performance of British Railways' three prototype Advanced Passenger Trains (APT-Ps) are discussed. The progression from design concept to construction, commissioning and testing prior to entry into passenger service is described. Performance aspects of the train and its sub-systems are assessed in relation to technical objectives.

The commissioning programme and highlights of the track proving trials are described. Important test results are discussed, including those relating to body tilt systems, ride quality, lateral track forces, braking performance, current collection, and thyristor interference. Account is given of various development problems which arose during commissioning trials and endurance running.

The paper concludes with a brief description of the design of the production train (APT-S), which is planned for fleet operation on BR's electrified West Coast routes.
Maintenance Aspects of London Transport Rolling Stock
Authors: Hafter G H , Morphew D J
Published: October 2007

This paper sketches the background to early electric railway operations and shows how the relative cheapness of labour against materials was responsible for the maintenance pattern. It goes on to describe briefly the basic maintenance system and operations involved in the early years and the developments between the wars, including the electrical and mechanical improvements resulting from developing technology. The post-war era and the major change in economic forces, particularly the relativities between labour and capital costs, and the constant pressures to ‘design out’, maintenance requirements are then dealt with rather more fully, with particular reference to the elimination of wearing parts and the increasing periods between inspections and repairs. The paper continues with the counter effects of competition from private transport and higher office and domestic environmental standards on vehicle sophistication. The present picture of London Transport railway rolling stock, with particular reference to the maintenance patterns and requirements of the latest types of tube and surface stocks, conclude the paper.
Heat Transfer in PAD Thrust Bearings
Authors: Neal P B
Published: October 2007

Results are presented of tests conducted on a 150 mm pad thrust bearing over the speed range 1000–4000 rev/min. Heat transfer to pads and runner is estimated from pad and runner temperatures. Pad heat transfer proved to be of minor importance. The runner is shown to approximate to an infinite heat sink. Heat transfer to the runner is dominated by the film thermal resistance and ranged from 0.1 to 0.8 of film energy dissipation. The dependence of film convective heat transport upon the film Peclet number is demonstrated and an improved method for the prediction of bearing performance is outlined.
The Use of Increased Wheel Flexibility to Improve Chatter Performance in Grinding
Authors: Sexton J S , Howes T D , Stone B J
Published: October 2007

The metal removal rates attainable during grinding may often be limited by the onset of an unstable vibration, commonly called regenerative chatter. Chatter is a self-induced vibration which leads to increased power consumption, a poor, generally unacceptable, ***workpiece surface finish, uneven wear of the grinding wheel and, in some cases, actual damage to the wheel.

It is known that chatter is more likely to occur when the grinding wheel is hard and for this reason chatter often develops when grinding with diamond or cubic boron nitride (CBN) wheels, whose chief characteristic is that they are very hard-wearing.

This paper describes the development of a technique for suppressing chatter which is particularly applicable to the use of diamond and CBN wheels. It has been predicted theoretically and confirmed by experiment that chatter may be suppressed, or even eliminated, by increasing the radial flexibility of a grinding wheel, whilst at the same time maintaining high values of the wheel's natural frequency and damping. It has been shown that the increased flexibility may be achieved by mounting the abrasive rim of the wheel via a flexible coupling, or by manufacturing a wheel by conventional means but with a flexible hub material. Both techniques are successful and diamond and CBN wheels, manufactured to these designs, have performed substantially better than conventional ultra-hard abrasive wheels currently marketed.

It is considered that the problem of chatter when using diamond or CBN wheels has been solved. Since this problem has represented one of the major obstacles to the acceptance of CBN wheels by industry, it is anticipated that these wheels will now enjoy a much more widespread usage.
Hydrodynamic Characteristics of Deaerator Head Drains Subject to an Adverse Differential Pressure
Authors: Cranfield R R
Published: October 2007

In some power plant deaerators, water is required to drain freely from the heating/deaerating head via vertical pipes into the storage tank, sometimes against an adverse differential pressure. The situation is shown to be complex in that six possible discharge regimes are possible, three of which are unstable. Unstable discharge results from steam breakthrough leading to the build up of sloshing water in the head, intermittent discharge and possibly head tray damage. Unstable discharge may also provide an explanation for the noise and vibration associated with deaerators, particularly during abnormal operation. Data and correlations are presented to enable the stable and unstable regimes to be identified and critical differential pressure to be calculated over a range of drain/drum radius ratios from 0.08 to 0.25. This in turn allows instability to be avoided or ‘designed-out’, as shown in a worked example.
Probabilities of Injury to Car Occupants in Accidents with a Practical Example
Authors: Grime G
Published: October 2007

Methods are described, by the application of which the probabilities of injury to car occupants in collisions of all types may be estimated from data on injury accidents alone, without having to make counts of accidents in which no injury had occurred. To do this, however, the velocity changes have to be known for all vehicles in the sample, so that separate probabilities of injury may be calculated for a number of successive small intervals of velocity change covering the range of velocity change in the accident sample.

Proceeding in this way, sets of curves of probability of injury at various levels of injury versus velocity change may be drawn, both for overall injury, and for injury to different regions of the body. A sample calculation at one value of velocity change is given.

The method is applicable to single vehicle accidents as well as to collisions, provided that there are at least two car occupants.

It is anticipated that the method will be particularly valuable when applied to estimate the effectiveness of seat belts, since it will then be possible to examine how the protection given changes with severity of accident, thus pointing to where improvements are desirable.

Difficulties which arise when certain analyses of injury accidents are made without introducing probability theory are discussed.
The Modelling of Semiflexible Conveyor Structures for Coal-Face Steering Investigations: Part 2: Spatially Continuous Models
Authors: Edwards J B
Published: October 2007

The structure of the armoured flexible conveyor (AFC) is here modelled as a continuous elastic beam resting on a bed of compressed fine coal. Such a model is shown, analytically and by simulation, to stabilize the vertical steering process for the coal-face provided the beam stiffness is sufficiently large.

The discrepancy between this prediction and that of the piecewise rigid model of the preceding companion paper (1) is noted and it is concluded that the elastic beam model may be more appropriate for larger undulations which take up all the free-play in the AFC joints.

Because of the potentially powerful stabilizing influence provided by the elastic model, it is proposed that the existing loose joints between AFC trays should be replaced by resilient couplings.
Housing and Environmental Policy in the UK
Authors: Bhatti Mark
Published: October 2007

Since the Earth Summit, held in Rio de Janeiro in 1992, the development of a ‘green’ housing policy for the UK has received considerable attention. Even though there appears to be a consensus that a more environmentally sustainable housing system is both necessary and desirable, the British government has emphasised market mechanisms to tackle environmental problems. This article critically examines this approach to environmental policy in the UK, especially in the area of energy conservation, and argues that market based mechanisms lead to uncoordinated and ineffectual initiatives that increase social inequalities.
The Private Sector and the NHS: the case of capital developments in primary healthcare
Authors: Glendinning Caroline , Bailey Jackie
Published: October 2007

English

This article describes the changing role of private sector capital investment in primary health services premises and discusses some of the consequences. Private sector funding has always played a major role in the financing of premises for general practitioner services. However, the extension of private sector involvement into new areas such as building design, income generation, revenue planning and facilities management may in turn influence the services which are accommodated within primary health services premises. The article discusses some of these implications in the context of a National Health Service which has still only recently begun to draw primary health services into mainstream managerial frameworks. It concludes that the management of private sector involvement in primary health services capital developments presents considerable challenges to probity, accountability and the achievement of broader strategic health objectives.
Toward designing new sensoaesthetic materials
Authors: Miodownik Mark A.
Published: October 2007

In ancient societies, there was no arts/science split. The development of materials was driven both by aesthetic and technological goals. At the end of the 19thcentury, things changed dramatically. Scientists started being able to analyze composition, detect structure, and make a link between structure and properties. The subsequent 20th-century revolution in new materials changed almost all aspects of human activity. However, it was not without serious side-effects, the first of which has been that the materials science community has willingly marginalized itself. The second is the eradication of interest in the sensual and aesthetic properties of materials, and thus the banishment of the creative urges that arrive via the senses. This paper discusses these issues, and suggests that collaboration with the materials arts community offers exciting new challenges and could create an intellectual community that is not just more culturally and ethically aware, but also nurtures more innovative science.
Enthalpies of formation and lattice parameters of B2 phases in Al-Ni-X systems
Authors: Hu Rongxiang , Su Hsin-Ning , Nash Philip
Published: October 2007

Enthalpies of formation of Al-Ni-X (X: Fe, Ru, Pd, Pt, and Cu) alloys were measured by high-temperature calorimeter and compared with the calculated value from Miedema's model and interpolation models. The interpolation models generally provide better prediction than Miedama's model. No one interpolation model generated superior predictions. Lattice parameters of B2 phase compounds were determined by X-ray diffraction (XRD). The atomic volumes in the Al-Ni-Fe system were calculated and show that Fe substitutes preferentially on the Al sublattice. The heat content of Al0.5Ni0.2Ru0.3 and Al0.5Ni0.35Cu0.15 at high temperature was obtained, and the results are in good agreement with those heat capacities estimated by the Neumann-Kopp rule.
Defect-fluorite oxides M1-yLnyO2-y/2(Ln = lanthanide; M = Hf, Zr, Ce, U, Th): Structure, property, and applications
Authors: Nakamura Akio , Masaki Nobuyuki , Otobe Haruyoshi , Hinatsu Yukio , Wang Junhu , Takeda Masuo
Published: October 2007

An up-to-date summary of our coupled macroscopic (lattice parameter, a
0) and microscopic (Mössbauer) studies on the entitled systems is given, shedding new light on the basic phase and structure properties of these technologically important, highly defective oxides. Through these studies, the intermediate-pyrochlore (P)-based local structure nature of the so-called stabilized-zirconia (SZ)- and stabilized-hafnia (SH)-type defect-fluorite (DF) phases in the M4+ = Zr and Hf systems seems to be almost unambiguously established with different (from the conventional) approaches: These are (1) the presence of a broad lattice parameter (a
0) hump over the extended stabilized cubic DF region (y = ~0.3-~0.7); (2) the microscopic 151Eu-Mössbauer evidence of Eu3+ isomer shifts (ISs) showing characteristic V-shaped minima around the ideal-P area (y ~ 0.50) for both the M4+ = Zr and Hf systems; and (3) rich 155Gd-Mössbauer data on the Zr1-y
GdyO2-y/2 system [IS, quadrupole splitting (QS), line width, peak height, and relative absorption area (RAA)], revealing detailed features of its ordered P-disordered DF phase and structure relationships. These results are discussed with reported basic-property data of these systems.
Phase diagrams and thermodynamics of rare-earth-doped zirconia ceramics
Authors: Wang Chong , Zinkevich Matvei , Aldinger Fritz
Published: October 2007

Results of the comprehensive experimental and computational phase studies of the systems ZrO2-REO1.5 (RE = La, Nd, Sm, Gd, Dy, Yb) are summarized. Various experimental techniques, X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), differential thermal analysis (DTA), and high-temperature calorimetry are employed to study the phase transformation, phase equilibria between 1400 and 1700 °C, heat content and heat capacity of the materials. A lot of contradictions in the literature are resolved, and the phase diagrams are reconstructed. Based on the experimental data obtained in this work and literature, the systems ZrO2-REO1.5 are thermodynamically optimized using the CALPHAD (CALculation of PHase Diagram) approach. Most of the experimental data are well reproduced. Based on the present experiments and calculations, some clear characteristic evolutions with the change of the ionic radius of doping element RE+3 can be concluded.
Interaction of Galectin-9 With Lipid Rafts Induces Osteoblast Proliferation Through the c-Src/ERK Signaling Pathway
Authors: Tanikawa Rena , Tanikawa Takahisa , Okada Yosuke , Nakano Kazuhisa , Hirashima Mitsuomi , Yamauchi Akira , Hosokawa Ryuji , Tanaka Yoshiya
Published: October 2007

Galectin-9 is a β-galactoside-binding lectin expressed in various tissues, including bone. The role of galectin-9 in human osteoblasts, however, remains unclear. This study showed that galectin-9 interacts with lipid rafts and induces osteoblast proliferation through the c-Src/ERK signaling pathway.

Introduction: Galectin-9 is a β-galactoside-binding lectin that modulates many biological functions by interacting with particular carbohydrates attached to proteins and lipids. However, the role of galectin-9 in bone metabolism and osteoblast proliferation remains unclear. This study investigated the effects of galectin-9 on osteoblast proliferation and its signaling mechanisms.

Materials and Methods: The effect of galectin-9 on osteoblast proliferation was tested by measuring the conversion of tetrazolium salt WST-8 to formazan. Protein phosphorylation was assayed by western blotting and confocal microscopy was used to localize lipid rafts.

Results: Galectin-9–induced proliferation of the obtained osteoblasts in a dose-dependent manner, whereas galectin-1, -3, and -4 did not. Galectin-9–induced phosphorylation of c-Src and subsequent ERK1/ERK2 in the osteoblasts. The galectin-9–induced phosphorylation and proliferation were inhibited by PP2, a selective inhibitor of c-Src. Galectin-9–induced clustering of lipid rafts detected by cholera toxin B (CTB; binding the raft-resident ganglioside GM1) using confocal microscopy. Cross-linking of the GM1 ganglioside with CTB by anti-CTB antibody-induced phosphorylation of c-Src, whereas disruption of galectin-9–induced lipid rafts by β-methylcyclodextrin reduced c-Src phosphorylation and proliferation of the cells.

Conclusions: These results suggest that galectin-9, but not other galectins, induced proliferation of human osteoblasts through clustering lipid rafts on membrane and subsequent phosphorylation of the c-Src/ERK signaling pathway.
Heritability of Longitudinal Measures of Body Mass Index and Lipid and Lipoprotein Levels in Aging Twins
Authors: Goode Ellen L. , Cherny Stacey S. , Christian Joe C. , Jarvik Gail P. , de Andrade Mariza
Published: October 2007

Body-mass index (BMI), total cholesterol (TC), lowdensity lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels are known to be highly heritable. We evaluated the genetic and environmental relationships of these measures over time in an analysis of twin pairs. Monozygotic (235 pairs) and dizygotic (260 pairs) male twins were participants in the National Heart Lung and Blood Institute Veteran Twin Study, and were followed with three clinical exams from mean age 48 years to mean age 63 years. Structural equation modeling (SEM) with adjustment forAPOEgenotype (a significant contributor to TC and LDL-C) was used to assess longitudinal patterns of heritability. Results indicated a contribution of genetic factors to BMI, TC, LDL-C, HLD-C, and TG. Modest increases over time were observed in the heritability of BMI (from 0.48 to 0.61), TC (from 0.46 to 0.57), LDL-C (from 0.49 to 0.64), and HDL-C (from 0.50 to 0.62), but this trend was not present for TG. There was a corresponding decrease in shared environmental influences over time for these traits, although shared environment was a significant contributor only for HDL-C. Moreover, we observed that genetic influences for all measures were significantly correlated over time, and we found no evidence of age-specific genetic effects. In summary, longitudinal analyses of twin data indicate that genetic factors do not account for a significant proportion of the variation in age-related changes of BMI or lipid and lipoprotein levels.
Twin Analyses of Fatigue
Authors: Schur Ellen , Afari Niloofar , Goldberg Jack , Buchwald Dedra , Sullivan Patrick F.
Published: October 2007

Prolonged fatigue equal to or greater than 1 month duration and chronic fatigue equal to or greater than 6 months duration are both commonly seen in clinical practice, yet little is known about the etiology or epidemiology of either symptom. Chronic fatigue syndrome (CFS), while rarer, presents similar challenges in determining cause and epidemiology. Twin studies can be useful in elucidating genetic and environmental influences on fatigue and CFS. The goal of this article was to use biometrical structural equation twin modeling to examine genetic and environmental influences on fatigue, and to investigate whether these influences varied by gender. A total of 1042 monozygotic (MZ) twin pairs and 828 dizygotic (DZ) twin pairs who had completed the University of Washington Twin Registry survey were assessed for three fatigue-related variables: prolonged fatigue, chronic fatigue, and CFS. Structural equation twin modeling was used to determine the relative contributions of additive genetic effects, shared environmental effects, and individual-specific environmental effects to the 3 fatigue conditions. In women, tetrachoric correlations were similar for MZ and DZ pairs for prolonged and chronic fatigue, but not for CFS. In men, however, the correlations for prolonged and chronic fatigue were higher in MZ pairs than in DZ pairs. About half the variance for both prolonged and chronic fatigue in males was due to genetic effects, and half due to individual-specific environmental effects. For females, most variance was due to individual environmental effects.
The Validity of Weinberg's Differential Rule
Authors: James William H.
Published: October 2007

Evidence continues to accumulate that Weinberg's Differential Rule is a useful approximation. This is in spite of the fact that one of the premises he used in its derivation is almost certainly, to some extent, false. An explanation is offered here.
New Sources of Reared Apart Twins; Research Reviews: Female Fitness in Male–Female Twin Pairs, Heritability of Olfactory Thresholds and the Twelfth International Twin Congress; Multiple Birth Conceptions: Rethinking Things; Double Donations
Authors: Segal Nancy L.
Published: October 2007

Adoption agencies are expending greater efforts toward placing adoptive twins and siblings together in the same home. However, new sources of reared apart twins continue to be identified. Some of these sources are described, with suggestions for how individual cases can be used more fruitfully by interested researchers. Next, recent findings on the fitness of female twins from male–female pairs and the heritability of olfactory thresholds are summarized. Finally, new thoughts about some artificially conceived infants and artificial reproductive methods are considered. A generous donation to the Twins Days Festival, in Twinsburg, Ohio is also described.
Camera Calibration Using Neural Network for Image-Based Soil Deformation Measurement Systems
Authors: Zhao Honghua , Ge Louis
Published: October 2007

A neural network camera calibration algorithm has been adapted for image-based soil deformation measurement systems. This calibration algorithm provides a highly accurate prediction of object data points from their corresponding image points. The experimental setup for this camera calibration algorithm is rather easy, and can be integrated into particle image velocimetry (PIV) to obtain the full-field deformation of a soil model. The performance of this image-based measurement system was illustrated with a small-scale rectangular footing model. This fast and accurate calibration method will greatly facilitate the application of an image-based measurement system into geotechnical experiments.
The “Practice Relevant Pitting Test”—A New Improved Test Method to Evaluate the Influence of Lubricants on the Pitting Load Capacity of Case Carburized Gears
Authors: Höhn B.-R. , Oster P. , Radev T. , Tobie T.
Published: October 2007

Pitting is a form of fatigue failure which occurs on the flanks of highly loaded case carburized gears. The lubricants, consisting of base oil and additives, influence the pitting lifetime of the gear flanks. Common calculation methods of the pitting load capacity consider, along with the flank roughness and the tangential velocity, only the nominal viscosity of a lubricant as a lubrication relevant influence parameter. The actual lubricant performance and particularly the influence of the additives can be determined only experimentally. Within a FVA-research project a new “Practice Relevant Pitting Test” was developed to evaluate the influence of lubricants on the pitting load capacity of case carburized gears. The new test method is a mechanical test procedure which is based on the existing FVA-FZG-Pitting Test. It is defined as a single stage test which can be extended to an application test by testing the lubricant with a second load stage. In order to improve the practice relevance and to reduce the scatter of the test results the test uses superfinished test gears with adequate profile modifications. The extremely low flank roughness of the new test gears prevents particularly the appearance of undesired micro-pitting and therefore improves the reproducibility of the reached lifetime within the performed test runs. The new pitting test procedure was verified with different gear transmission lubricants and is seen as an improvement of the existing FVA-FZG-Pitting Test. It provides also a possibility to consider the test results for calculation of the pitting load capacity of industrial and automotive transmission gears with an additional factor ZLp which is to be applied in the calculation method according to DIN 3990. The paper describes the new developed test procedure “Practice Relevant Pitting Test” and discusses the correlation and classification to the existing FVA-FZG-Pitting Test.
Cerebral White Matter Injury
Authors: Back Stephen A. , Miller Steven P.
Published: October 2007

Despite advances in neonatal intensive care, periventricular white matter injury (PWMI) remains the most common cause of brain injury in preterm infants and the leading cause of chronic neurologic morbidity. Factors implicated in the pathogenesis of PWMI during prematurity include hypoxia, ischemia, and maternal-fetal infection. PWMI is recognized increasingly in term newborns who have congenital heart disease. The spectrum of chronic PWMI includes focal cystic necrotic lesions (periventricular leukomalacia [PVL]) and diffuse myelination disturbances. Information about the prevalence, severity, and distribution of white matter lesions has relied heavily on neuropathology studies of autopsy brains. However, advances in magnetic resonance imaging of the neonatal brain suggest that the incidence of PVL is declining; focal or diffuse noncystic injury is emerging as the predominant lesion. Insight into the cellular and molecular basis for these shifting patterns of injury has emerged from recent studies with several promising experimental models. These studies support the suggestion that PWMI can be initiated by impaired cerebral blood flow related to anatomic and physiologic immaturity of the vasculature. Ischemic cerebral white matter is susceptible to pronounced free radical-mediated injury that particularly targets immature stages of the oligodendrocyte lineage. The developmental predilection for PWMI to occur during prematurity appears to be related to both the timing of appearance and regional distribution of susceptible late oligodendrocyte progenitors. It is anticipated that new strategies for prevention of brain injury in preterm infants will develop as a result of improved recognition of changing patterns of injury that reflect specific types of cellular vulnerability.
Association Between Infant Breastfeeding and Early Childhood Caries in the United States
Authors: Iida Hiroko , Auinger Peggy , Billings Ronald J. , Weitzman Michael
Published: October 2007

OBJECTIVE. Despite limited epidemiologic evidence, concern has been raised that breastfeeding and its duration may increase the risk of early childhood caries. The objective of this study was to assess the potential association of breastfeeding and other factors with the risk for early childhood caries among young children in the United States.

METHODS. Data about oral health, infant feeding, and other child and family characteristics among children 2 to 5 years of age (N = 1576) were extracted from the 1999–2002 National Health and Nutrition Examination Survey. The association of breastfeeding and its duration, as well as other factors that previous research has found associated with early childhood caries, was examined in bivariate analyses and by multivariable logistic and Poisson regression analyses.

RESULTS. After adjusting for potential confounders significant in bivariate analyses, breastfeeding and its duration were not associated with the risk for early childhood caries. Independent associations with increased risk for early childhood caries were older child age, poverty, being Mexican American, a dental visit within the last year, and maternal prenatal smoking. Poverty and being Mexican American also were independently associated with severe early childhood caries, whereas characteristics that were independently associated with greater decayed and filled surfaces on primary teeth surfaces were poverty, a dental visit within the last year, 5 years of age, and maternal smoking.

CONCLUSIONS. These data provide no evidence to suggest that breastfeeding or its duration are independent risk factors for early childhood caries, severe early childhood caries, or decayed and filled surfaces on primary teeth. In contrast, they identify poverty, Mexican American ethnic status, and maternal smoking as independent risk factors for early childhood caries, which highlights the need to target poor and Mexican American children and those whose mothers smoke for early preventive dental visits.
Improving Asthma-Related Health Outcomes Among Low-Income, Multiethnic, School-aged Children: Results of a Demonstration Project That Combined Continuous Quality Improvement and Community Health Worker Strategies
Authors: Fox Patrick , Porter Patricia G. , Lob Sibylle H. , Boer Jennifer Holloman , Rocha David A. , Adelson Joel W.
Published: October 2007

OBJECTIVE. The purpose of this work was to improve asthma-related health outcomes in an ethnically and geographically disparate population of economically disadvantaged school-aged children by using a team-based approach using continuous quality improvement and community health workers.

PATIENTS AND METHODS. A demonstration project was conducted with 7 community clinics treating ∼3000 children with asthma 5 to 18 years of age. The overall clinic population with asthma was assessed for care-process changes through random cross-sectional chart reviews at baseline and 24 months (N = 560). A subset of patients with either moderate or severe persistent asthma or poorly controlled asthma (N = 405) was followed longitudinally for specific asthma-related clinical outcomes, satisfaction with care, and confidence managing asthma by family interview at baseline and at 12 or 24 months. Patient-centered and care-process outcomes included patient/parent assessment of quality of care and confidence in self-management, asthma action plan review, and documentation of guideline-based indicators of quality of care. Direct clinical outcomes included daytime and nighttime symptoms, use of rescue medications, acute care and emergency department visits, hospitalizations, and missed school days. Each clinic site's degree of adherence to the intervention model was evaluated and ranked to examine the correlation between model adherence and outcomes.

RESULTS. Cross-sectional data showed clinic-wide improvements in the documentation of asthma severity, review of action plans, health services use, and asthma symptoms. At follow-up in the longitudinal sample, fewer patients reported acute visits, emergency department visits, hospitalizations, frequent daytime and nighttime symptoms, and missed school days compared with baseline. More patients reported excellent or very good quality of care and confidence in asthma self-management. Linear regression analysis of the clinical sites’ model adherence ranks against site-level combined scores estimating overall outcomes, clinical outcomes, and improvements in clinical care processes showed significant linear correlations with R2 ≥ 0.60.

CONCLUSIONS. The demonstration produced major improvements in asthma-related care processes and clinical outcomes. Closer adherence to the demonstration model was directly associated with better outcomes.
Adverse Birth Outcome Among Mothers With Low Serum Cholesterol
Authors: Edison Robin J. , Berg Kate , Remaley Alan , Kelley Richard , Rotimi Charles , Stevenson Roger E. , Muenke Maximilian
Published: October 2007

OBJECTIVE. The objective of this study was to assess whether low maternal serum cholesterol during pregnancy is associated with preterm delivery, impaired fetal growth, or congenital anomalies in women without identified major risk factors for adverse pregnancy outcome.

METHODS. Mother-infant pairs were retrospectively ascertained from among a cohort of 9938 women who were referred to South Carolina prenatal clinics for routine second-trimester serum screening. Banked sera were assayed for total cholesterol; <10th percentile of assayed values (159 mg/dL at mean gestational age of 17.6 weeks) defined a “low total cholesterol” prenatal risk category. Eligible women were aged 21 to 34 years and nonsmoking and did not have diabetes; neonates were liveborn after singleton gestations. Total cholesterol values of eligible mothers were adjusted for gestational age at screening before risk group assignment. The study population included 118 women with low total cholesterol and 940 women with higher total cholesterol. Primary analyses used multivariate regression models to compare rates of preterm delivery, fetal growth parameters, and congenital anomalies between women with low total cholesterol and control subjects with mid–total cholesterol values >10th percentile but <90th percentile.

RESULTS. Prevalence of preterm delivery among mothers with low total cholesterol was 12.7%, compared with 5.0% among control subjects with mid–total cholesterol. The association of low maternal serum cholesterol with preterm birth was observed only among white mothers. Term infants of mothers with low total cholesterol weighed on average 150 g less than those who were born to control mothers. A trend of increased microcephaly risk among neonates of mothers with low total cholesterol was found. Low maternal serum cholesterol was unassociated with risk for congenital anomalies.

CONCLUSIONS. Total serum cholesterol <10th population percentile was strongly associated with preterm delivery among otherwise low-risk white mothers in this pilot study population. Term infants of mothers with low total cholesterol weighed less than control infants among both racial groups.
Effects of Nurse Home Visiting on Maternal and Child Functioning: Age-9 Follow-up of a Randomized Trial
Authors: Olds David L. , Kitzman Harriet , Hanks Carole , Cole Robert , Anson Elizabeth , Sidora-Arcoleo Kimberly , Luckey Dennis W. , Henderson Charles R. , Holmberg John , Tutt Robin A. , Stevenson Amanda J. , Bondy Jessica
Published: October 2007

OBJECTIVE. Our goal was to test the effect of prenatal and infancy home visits by nurses on mothers' fertility and children's functioning 7 years after the program ended at child age 2.

METHODS. We conducted a randomized, controlled trial in a public system of obstetric and pediatric care. A total of 743 primarily black women <29 weeks' gestation, with previous live births and at least 2 sociodemographic risk characteristics (unmarried, <12 years of education, unemployed), were randomly assigned to receive nurse home visits or comparison services. Primary outcomes consisted of intervals between births of first and second children and number of children born per year; mothers' stability of relationships with partners and relationships with the biological father of the child; mothers' use of welfare, food stamps, and Medicaid; mothers' use of substances; mothers' arrests and incarcerations; and children's academic achievement, school conduct, and mental disorders. Secondary outcomes were the sequelae of subsequent pregnancies, women's employment, experience of domestic violence, and children's mortality.

RESULTS. Nurse-visited women had longer intervals between births of first and second children, fewer cumulative subsequent births per year, and longer relationships with current partners. From birth through child age 9, nurse-visited women used welfare and food stamps for fewer months. Nurse-visited children born to mothers with low psychological resources, compared with control-group counterparts, had better grade-point averages and achievement test scores in math and reading in grades 1 through 3. Nurse-visited children, as a trend, were less likely to die from birth through age 9, an effect accounted for by deaths that were attributable to potentially preventable causes.

CONCLUSIONS. By child age 9, the program reduced women's rates of subsequent births, increased the intervals between the births of first and second children, increased the stability of their relationships with partners, facilitated children's academic adjustment to elementary school, and seems to have reduced childhood mortality from preventable causes.
Weight Faltering in Infancy and IQ Levels at 8 Years in the Avon Longitudinal Study of Parents and Children
Authors: Emond Alan M. , Blair Peter S. , Emmett Pauline M. , Drewett Robert F.
Published: October 2007

OBJECTIVE. Our goal was to investigate the association between failure to thrive (defined as weight faltering in the first 9 months of life) and IQ levels 8 years later.

METHODS. Weight gain (conditional on initial weight) from birth to 8 weeks, 8 weeks to 9 months, and birth to 9 months was measured on term infants from the Avon Longitudinal Study of Parents and Children. Cases of weight faltering were defined as those infants with a conditional weight gain below the 5th centile who were compared with the rest of the cohort as the control group. At the age of 8 years, 5771 infants born at term with no major congenital abnormalities had IQ measured by using the Wechsler Intelligence Scale for Children, Third Revision.

RESULTS. Mean (SD) IQ scores were 104.7 (16.3) (total), 107.6 (16.5) (verbal), and 100.2 (16.9) (performance). Children whose weight faltered from birth to 9 months had a total IQ that was significantly lower by an average of −2.71 points at 8 years, equivalent to 0.17 SD. Weight gain from birth to 8 weeks had a positive linear association with child IQ at 8 years. This remained significant in a multivariate regression despite controlling for correlates of both infant growth and child IQ; 1 SD of weight gain was associated with a difference of 0.84 points in the total IQ score. In contrast to early weight faltering, weight gain from 8 weeks to 9 months was not related to IQ at 8 years.

CONCLUSIONS. Failure to thrive in infancy was associated with persisting deficits in IQ at 8 years; the critical period for growth faltering was birth to 8 weeks. The relationship between infant growth from birth to 8 weeks and later intellectual development was approximately linear over the whole range of weight velocities.
Disruptions in Insurance Coverage: Patterns and Relationship to Health Care Access, Unmet Need, and Utilization Before Enrollment in the State Children's Health Insurance Program
Authors: Federico Steven G. , Steiner John F. , Beaty Brenda , Crane Lori , Kempe Allison
Published: October 2007

BACKGROUND. The numbers and types of disruptions in insurance that children experience and the effects of these disruptions on health care measures have not been well characterized.

OBJECTIVES. Our goals were to (1) describe the number and patterns of insurance disruptions within a population of children newly enrolling into the State Children's Health Insurance Program and (2) assess the relationship among insurance disruptions and sociodemographic characteristics of these children and their families to specific measures of access to care, unmet need, and health care utilization during the year before enrollment.

METHODS. We conducted telephone interviews in families with children newly enrolling in the State Children's Health Insurance Program. Families reported on measures for each of the 12 months preceding enrollment. They were grouped by number of insurance disruptions in the year before enrollment: continuously uninsured, ≥2 disruptions, 1 disruption, or continuously insured.

RESULTS. Of 920 families contacted, 739 (80%) completed the interview and 710 had useable data. Thirty-five percent reported being continuously uninsured, 42% were intermittently insured (≥2 disruptions: 28%; 1 disruption: 14%), and 23% were continuously insured during the previous year. The most common patterns of change were between privately insured and uninsured (49%) and Medicaid and uninsured (40%). The continuously uninsured were more likely to be Hispanic and older in age. Multivariate modeling confirmed a gradient between greater insurance disruption and less access to care, less utilization, and greater unmet medical need. Using the continuously uninsured as a reference group, the adjusted odds ratio for having a medical home varied from 2.5 for those with ≥2 disruptions to 4.5 for the continuously insured and from 1.9 to 3.2, respectively, for using any regular/routine care. The odds ratio for unmet need for a prescription medication was 0.9 for ≥2 disruptions and 0.5 for those with continuous insurance coverage.

CONCLUSIONS. There was significant disruption in insurance coverage in the year before State Children's Health Insurance Program enrollment. Most of these disruptions took the form of children previously enrolled in either Medicaid or private insurance becoming uninsured. Increasing numbers of disruptions were associated with less routine care and greater unmet medical need. These findings suggest that disruptions in insurance coverage for children should be minimized with the adoption of policies regarding continuous eligibility criteria for Medicaid and streamlining transitions between Medicaid, the State Children's Health Insurance Program, and private insurance.