bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast tool servo control for diamond-cutting microstructured optical components
Authors: Zhang H. J. , Chen S. J. , Zhou M. , Yang Y. H.
Published: May 2009

In diamond-cutting microstructured surfaces, variations in cutting depth and cutting speed due to sharp-corner and step structures in some microstructured surfaces such as Fresnel lens make the control system of fast tool servo (FTS) unstable, and therefore decrease the surface quality and even lead to tool fracture. In addition, to achieve precise positioning, the control strategy for FTS must adequately eliminate the effect of piezoelectric nonlinear characteristics such as hysteresis and creep. In this article, an adaptive variable-structure sliding-mode control (VSSMC) algorithm for FTS was proposed to solve these problems. Comparative tests were conducted between the conventional proportion-integration-differentiation and the VSSMC algorithm. Testing results verify that the variable-structure sliding-mode controller is robust against changes in system parameters and disturbances of cutting forces in the cutting process. It is also able to track the command position quickly with high steady state accuracy and without overshoot.
Defects in zinc-implanted ZnO thin films
Authors: Schmidt Matthias , Ellguth Martin , Czekalla Christian , v. Wenckstern Holger , Pickenhain Rainer , Grundmann Marius , Brauer Gerhard , Skorupa Wolfgang , Helm Manfred , Gu Qilin , Ling Chi Chung
Published: May 2009

Defects in zinc-implanted and thermally annealed ZnO thin films were investigated by means of capacitance-voltage spectroscopy (C-V), thermal admittance spectroscopy (TAS), deep level transient spectroscopy (DLTS), and photoluminescence (PL) spectroscopy. The authors report on the formation of two donor states approximately 35 and 190meV below the conduction band edge, observed by TAS and DLTS, respectively. In the PL spectra of a reference sample a peak at 3.366eV was present, which diminished after the implantation, while a new peak at 3.364eV was observed only in the spectrum of the implanted sample. Since only intrinsic ions were implanted, the authors consider the defects formed by the zinc implantation and annealing to be intrinsic.
Electron transport properties of Zn0.88Mn0.12O∕ZnO modulation-doped heterostructures
Authors: Masuko K. , Ashida A. , Yoshimura T. , Fujimura N.
Published: May 2009

The authors have investigated the electron transport properties of Zn1−xMnxO∕ZnO modulation-doped heterostructures grown on ZnO (0001¯) single-crystal substrates. By varying the growth temperature (Tg) of ZnO and Zn1−xMnxO layers, the growth mode changes from three-dimensional grain growth to two-dimensional growth. In this study, Zn0.88Mn0.12O∕ZnO heterostructures with different growth modes of the Zn0.88Mn0.12O barrier layer were fabricated by deposition at different Tg. The effect of the growth mode of the Zn0.88Mn0.12O barrier layer on carrier confinement at the Zn0.88Mn0.12O∕ZnO heterointerface is discussed.
Diamond cutting of a large off-axis Fresnel lens Mold
Authors: Guo Jianqiang , Ohmori Hitoshi , Uehara Yoshihiro , Morita Shinya , Katahira Kazutoshi
Published: May 2009

The oxygen-free copper (OFC) is often used for the substrate material of the molds for the hot hydraulic press, the injection, and the light guide plate. The diamond cutting is usually used for the high precision finish process of the nonferrous metals. In this article, an OFC mold, which is used for testing the hot hydraulic press process of the large segmental double-side polymethyl methacrylate (PMMA) Fresnel lens, was designed. The rotary radius of this mold is about 1000mm and the mold must be fabricated to the high form accuracy and the low surface roughness. According to the conventional machining method, a rotary table with the radius larger than 1000mm is necessary for fabricating this mold. However, this mold is justly used for the first test of the hot hydraulic press of the large segmental double-side PMMA Fresnel lens. Thus, the fabrication of this mold should be carried out at the lower cost using the holding machine tool. In order to cut this mold on an ultraprecision air hydrostatic bearing rotary table of 500mm in diameter, a special method was proposed by the authors of this article. In this experiment, the diamond cutting process of the mold was investigated. The single crystal diamond cutting tool with the tip radius of 1μm was used at the depth of cut 1μm for the finish process in order to get the mold with the very small groove corner. After the finish cutting process, the surface has a very low roughness.
Development of the control system for three-axis ultraprecision compact micromilling machine
Authors: Wang Bo , Zhang Peng , Liang Yingchun , Dong Shen
Published: May 2009

In order to overcome the nonlinearity of the conventional servomechanism driven by ball screws, coreless linear motors are directly used to drive air bearing slides. Linear encoders with a resolution of 1.2 nm are used as position feedbacks. A dynamics model is established for stacked X-Y stages, and the system resonance is then theoretically analyzed and experimentally verified. In order to improve the performance of the stacked stages, a compound proportional-integral-derivative controller with a notch filter is developed using zero-pole assignment and model parameter matching method. Experimental results show that the controller developed can work to reduce the mechanical resonance caused by the cross-coupled stiffness, and the minimum positioning resolution of the micromilling machine is 20 nm. To track a sinusoidal signal with a frequency of 30 Hz and an amplitude of 5 μm, the phase lag is less than 10° and the amplitude attenuation is less than 10% for all the three axes.
Measuring the nose roundness of diamond cutting tools based on atomic force microscopy
Authors: Li Z. Q. , Sun T. , Li P. , Zhao X. S. , Dong S.
Published: May 2009

The nose roundness is one of the most important indices of lapping quality of circular-arc diamond cutting tools. Because of its special requirements, until now there was no efficient method to measure the nose roundness. In this article, a new way, based on atomic force microscope and precision-revolution axis, to measure the nose arc of tools is proposed. A radius constraint least-squares circle fitting method is put forward. The metrical data are fitted by the nonlinear fitting function Lsqnonlin in software matrix laboratory (MATLAB). Also, the peak-valley value is used to assess the nose roundness. The method fully meets the needs of measurement and evaluation of circular-arc diamond cutting tools’ nose roundness.
Electrical and optical studies of metal organic chemical vapor deposition grown N-doped ZnO films
Authors: Marzouki A. , Mimila J. , Oueslati M. , Laroche J. M. , Jomard F. , Lusson A. , Galtier P. , Sallet V.
Published: May 2009

Nitrogen-doped ZnO films were grown by metal organic chemical vapor deposition using diallylamine as the doping source. Secondary ion mass spectrometry measurements attest for the incorporation of nitrogen up to 1020cm−3, and both photoluminescence and Raman characterization exhibit nitrogen related peaks. As-deposited layers have been characterized by Hall effect, and most exhibit n-type conductivity, with electron concentrations from 1017 up to a few 1019cm−3. Unstable p-type behavior is sometimes observed on low quality layers grown using a very low RVI∕II ratio. Ex situ annealing experiments in oxygen atmosphere show different tendencies depending on the growth conditions and can lead to a strong decrease in the electron concentration by three orders of magnitude. These results are discussed in relation to the structural and optical characterizations.
About the Cu-related green luminescence band in ZnO
Authors: Reshchikov Michael A. , Avrutin V. , Izyumskaya N. , Shimada R. , Morkoç H. , Novak S. W.
Published: May 2009

Cu-related green luminescence (GL) band in n-type ZnO layers grown by molecular beam epitaxy on sapphire and a bulk ZnO sample grown by hydrothermal method have been studied with above-bandgap excitation. Annealing of the samples in air at temperatures above 600°C resulted in an increase in the concentration of CuZn acceptors, followed by a dramatic enhancement of the Cu-related GL band peaking at 2.45eV, and a characteristic fine structure. The GL band quenched at temperatures between 250 and 500K due to escape of holes from the excited state of the CuZn acceptor to the valence band. Energy position of this state in the bandgap of ZnO and its capture cross section for holes were estimated as 0.38eV and 2×10−13cm2, respectively.
Thermal imprint into thin polymer layers below the critical molecular weight
Authors: Bogdanski Nicolas , Wissen Matthias , Möllenbeck Saskia , Scheer Hella-Christin
Published: May 2009

Imprints into thin thermoplastic layers in thermal imprint often go along with phenomena such as physical self-assembly and recovery, which impair the resulting replication quality. To avoid recovery, in particular within larger structures, a polymer with extremely low Mw (polystyrene with a molecular weight of 1kg∕mol) is investigated. In contrast to expectations, the polymer develops a strong recovery. This occurs at such low viscosities that the imprint is also impaired by strong physical self-assembly effects. The imprint is further hampered by the fact that, due to the very low glass-transition temperature, a layer preparation without prebake is required. In addition the suitable temperature window for imprint is extremely small (T≈40°C) so that process control is hardly feasible. Polystyrene with such low Mw is not suitable for thermal imprint.
Laser micromachining of optical microstructures with inclined sidewall profile
Authors: Wang X. H. , Lai P. T. , Choi H. W.
Published: May 2009

Laser micromachining has been proved to be a useful tool for the formation of microstructures in semiconductor and optical materials. It is also widely adopted for dicing of light-emitting diode chips. The authors propose a modified laser micromachining setup which enables three-dimensional structures to be formed. A mirror is inserted in the optical path between the focusing optics and the machining plane so that the beam strikes the sample at an oblique angle. By translating and/or rotating the sample as micromachining is carried out, various three-dimensional structures such as a pyramid or a conic section can be obtained. Trenches as small as 10 μm on sapphire have been realized with nanosecond ultraviolet laser pulses. Laser-induced damage, due to resolidification of the ablation melt, accumulates with increasing scans of the beam; it can be removed by chemical and mechanical treatment.
Isolation of organic field-effect transistors by surface patterning with an UV/ozone process
Authors: Kim Sung-Jin , Beveridge Henry , Koberstein Jeffrey T. , Kymissis Ioannis
Published: May 2009

The authors present a patterning technique for isolating organic field-effect transistors via an ultraviolet/ozone process. The technique relies on the conversion of a poly(dimethylsiloxane) (PDMS) film to a silicon oxide (SiOx) which provides the selective growth of pentacene thin films on hydrophobic and smooth PDMS and hydrophilic and rough SiOx created by photoinduced conversion of the PDMS. They demonstrate that pentacene films grown on PDMS have five times greater channel conductivity than those grown on the SiOx film, and this difference in performance can be exploited to partially pattern active devices and reduce leakage using a photopatterning technique.
Effect of nanocomposite gate dielectric roughness on pentacene field-effect transistor
Authors: Lee Wen-Hsi , Wang C. C.
Published: May 2009

The effects of the surface roughness of the nanocomposite gate dielectric on the correlation between grain size and mobility of pentacene organic thin-film transistors were investigated. In this work, the nanocomposite as gate dielectric film was carried out by blending polyimide and nano-TiO2 particles to enhance the capacitance of the gate dielectric. The roughness of the nanocomposite gate dielectric is varied from 0.8to20nm with increasing TiO2 concentration from 0to5vol% in polyimide. Grain size of pentacene decreases with increasing roughness of the nanocomposite gate dielectric film. Two distinguishable regions are observed on the correlation between grain size and mobility of pentacene. In region (I), the nanocomposite gate dielectric with 0–2vol% TiO2 content shows that mobility does not significant change with decreasing grain size of pentacene, similar to the behavior of the organic polymer gate dielectric. In region (II), the nanocomposite gate dielectric with 3–5vol% TiO2 content shows that mobility is remarkably decreased with decreasing grain size of pentacene, similar to the behavior of the inorganic gate dielectric.
Fabrication of one-dimensional and two-dimensional periodically polarity inverted ZnO structures using the patterned CrN buffer layers
Authors: Park J. S. , Minegishi T. , Lee S. H. , Im I. H. , Park S. H. , Goto T. , Cho M. W. , Yao T. , Hong S. K. , Lee J. W. , Lee J. Y. , Ahn S. , Jeon H. , Lee W. , Jung M. N. , Chang J. H.
Published: May 2009

By employing the simple patterning and regrowth procedures, one-dimensional and two-dimensional (2D) periodically polarity inverted (PPI) ZnO structures are fabricated on (0001) Al2O3 substrates. For the selection of Zn- and O-polarity of ZnO films, patterned CrN buffer layers and Al2O3 substrates are used, respectively. The periodical change of the polarity is clearly confirmed by the polarity sensitive piezoresponse microscopy images, which are evidences for the successful fabrication of periodical polarity inversion structures. Cathodoluminescence investigation revealed that both polar layers have high crystal quality with strong free exciton emission. Moreover, 2D PPI ZnO structures with subnanometer scale periodicity are demonstrated by using the holographic lithography.
UV light-induced changes to the surface conduction in hydrothermal ZnO
Authors: Claflin B. , Look D. C.
Published: May 2009

High quality, bulk ZnO crystals grown by Tokyo Denpa using the hydrothermal process typically exhibit a room temperature carrier concentration in the 1013–1014 cm−3 range and a low mobility, conductive surface layer, observed at low temperature, with a sheet concentration on the order of 1012–1013 cm−2. In the sample discussed here, bulk conduction is controlled by two donor levels at 50 and 400 meV with concentrations of 1.2×1016 and 1.5×1016 cm−3, respectively. Temperature-dependent photo-Hall-effect measurements, using blue/UV light, in vacuum show an increase in the surface sheet carrier density to more than 1×1013 cm−2 at low to intermediate temperatures while the two bulk donors continue to dominate the high temperature behavior, up to 400 K. Long-lived persistent photoconductivity (PPC) is observed when the sample is returned to the dark. When the PPC is allowed to fully relax and the sample is exposed to air, there is surprisingly no longer any surface conduction at low temperature, while the two bulk donors remain unaffected. In this state, the 50 meV bulk donor level is observed to control the conduction over five orders of magnitude, down to a carrier concentration of 3.0×108 cm−3. This corresponds to an upper limit for the surface sheet carrier density of 1.6×107 cm−2. This is the lowest surface concentration we have ever observed in any ZnO sample and demonstrates that blue/UV light irradiation, in vacuum, at moderate temperatures is very effective at cleaning the surface. A subsequent 30 min anneal at 600 °C in forming gas (5% H2 in N2) increases the carrier concentration by almost two orders of magnitude. The forming gas anneal produces no changes in the concentrations of the 50 and 400 meV bulk donor levels and no new bulk donors are observed. However, the bulk acceptor concentration decreases from 2×1016 to 1.2×1016 cm−3, most likely as a result of passivation by hydrogen.
Enhancing the performance of polycrystalline diamond tools for machining WC by ultrasonic elliptical vibration cutting method
Authors: Nath Chandra , Rahman Mustafizur , Neo Ken Soon
Published: May 2009

Precise machining or shaping of difficult-to-cut materials, such as tungsten carbide (WC), hardened steels, and optical glass, is always difficult to achieve by applying conventional cutting (CC) methods. Recently, the ultrasonic elliptical vibration cutting (UEVC) method has been successfully applied to machine some of such materials. However, this novel machining method has yet to be applied on WC using polycrystalline diamond (PCD) tools. This study aims to enhance the machining performance of commercial PCD tools for machining sintered WC by applying the UEVC method. First, the effects of cutting parameters on the cutting performance have been studied to establish a set of best cutting conditions. Then a case study has been carried out to justify whether the cutting performance in the UEVC method can further be improved by varying the related parameters but keeping the same machining rate. To substantiate the feasibility of UEVC method, a comparative performance of this method has been carried out with that of its CC counterpart. Experimental results have shown that the UEVC method results in better cutting performance with the decrease in the feed rate at the speed ratio of less than 1. A surface roughness of 0.027μm Ra has been achieved on a machining area about 1257mm2 with the UEVC method. The findings reveal that the performance of PCD tools could be enhanced by the UEVC method for ultraprecision machining of hard-to-cut materials.
Electrochemical growth and characterization of Ag-doped ZnO nanostructures
Authors: Thomas M. A. , Cui J. B.
Published: May 2009

Both undoped and Ag-doped ZnO nanostructures were prepared using an electrochemical process at temperatures between 60 and 95°C. The samples were characterized by scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and temperature dependent photoluminescence measurements (PL). The effects of parameters such as silver nitrate concentration and the applied potential on the material growth were investigated. As grown Ag-doped samples exhibit significant differences from undoped samples as indicated by their morphology and optical properties. Furthermore, after annealing in oxygen, Ag-doped samples show different trends compared to undoped samples as evidenced by a significant decrease in defect PL emissions. Possible mechanisms for the annealing effects are discussed.
Micro-electron-beam welding with a modified scanning electron microscopy: Findings and prospects
Authors: Reisgen U. , Dorfmüller T.
Published: May 2009

The ISF (Joining and Welding Institute, RWTH Aachen University) is dealing with the adaptation of the long-established electron beam (EB) welding process to the special boundary conditions and requirements of the field of microapplications. A modified scanning electron microscope is being used as a micro-EB welding machine. Process-specific advantages offer the best preconditions for hybrid microassembly purposes. Joining of microcomponents presupposes optimal contact conditions, which are difficult to implement due to the ratio of forces during the joining process and also the low stiffness of the components. Besides the application of a suitable handling technique, the possibility to exert influence on the thermal distortion by symmetrical heating and solidification processes is of particular importance. The reproducibility of the welded joints is one of the great challenges in the field of microwelding. The investigations and developments done at the ISF show successful results in joining stainless steel sheet materials down to 30μm thickness and steel wire down to 50μm in diameter, whereas other materials (tungsten, aluminum, and titanium, nickel) are under investigation.
Organization, Evolution, and Expression Analysis of the Biosynthetic Gene Cluster for Scytonemin, a Cyanobacterial UV-Absorbing Pigment
Authors: Sorrels Carla M. , Proteau Philip J. , Gerwick William H.
Published: May 2009

Cyanobacteria are photosynthetic prokaryotes capable of protecting themselves from UV radiation through the biosynthesis of UV-absorbing secondary metabolites, such as the mycosporines and scytonemin. Scytonemin, a novel indolic-phenolic pigment, is found sequestered in the sheath, where it provides protection to the subtending cells during exposure to UV radiation. The biosynthesis of scytonemin is encoded by a previously identified gene cluster that is present in six cyanobacterial species whose genomes are available. A comparison of these clusters reveals that two major cluster architectures exist which appear to have evolved through rearrangements of large sections, such as those genes responsible for aromatic amino acid biosynthesis and through the insertion of genes that potentially confer additional biosynthetic capabilities. Differential transcriptional expression analysis demonstrated that the entire gene cluster is transcribed in higher abundance after exposure to UV radiation. This analysis helps delineate the cluster boundaries and indicates that regulation of this cluster is controlled by the presence or absence of UV radiation. The findings from an evolutionary phylogenetic analysis combined with the fact that the scytonemin gene cluster is distributed across several cyanobacterial lineages led to our proposal that the distribution of this gene cluster is best explained through an ancient evolutionary origin.
Identification of a Terminal Rhamnopyranosyltransferase (RptA) Involved inCorynebacterium glutamicumCell Wall Biosynthesis
Authors: Birch Helen L. , Alderwick Luke J. , Rittmann Doris , Krumbach Karin , Etterich Helga , Grzegorzewicz Anna , McNeil Michael R. , Eggeling Lothar , Besra Gurdyal S.
Published: May 2009

A bioinformatics approach identified a putative integral membrane protein, NCgl0543, inCorynebacterium glutamicum, with 13 predicted transmembrane domains and a glycosyltransferase motif (RXXDE), features that are common to the glycosyltransferase C superfamily of glycosyltransferases. The deletion ofC. glutamicumNCgl0543 resulted in a viable mutant. Further glycosyl linkage analyses of the mycolyl-arabinogalactan-peptidoglycan complex revealed a reduction of terminal rhamnopyranosyl-linked residues and, as a result, a corresponding loss of branched 2,5-linked arabinofuranosyl residues, which was fully restored upon the complementation of the deletion mutant by NCgl0543. As a result, we have now termed this previously uncharacterized open reading frame,rhamnopyranosyltransferaseA(rptA). Furthermore, an analysis of base-stable extractable lipids fromC. glutamicumrevealed the presence of decaprenyl-monophosphorylrhamnose, a putative substrate for the cognate cell wall transferase.
Periadventitial adipose tissue impairs coronary endothelial function via PKC-β-dependent phosphorylation of nitric oxide synthase
Authors: Payne Gregory A. , Bohlen H. Glenn , Dincer Ü. Deniz , Borbouse Léna , Tune Johnathan D.
Published: May 2009

Endogenous periadventitial adipose-derived factors have been shown to contribute to coronary vascular regulation by impairing endothelial function through a direct inhibition of endothelial nitric oxide synthase (eNOS). However, our understanding of the underlying mechanisms remains uncertain. Accordingly, this study was designed to test the hypothesis that periadventitial adipose tissue releases agents that attenuate coronary endothelial nitric oxide production via a protein kinase C (PKC)-β-dependent mechanism. Isometric tension studies were conducted on isolated canine circumflex coronary arteries with and without natural amounts of periadventitial adipose tissue. Adipose tissue significantly diminished coronary endothelial-dependent vasodilation and nitric oxide production in response to bradykinin and acetylcholine. The selective inhibition of endothelial PKC-β with ruboxistaurin (1 μM) abolished the adipose-induced impairment of bradykinin-mediated coronary vasodilation and the endothelial production of nitric oxide. Western blot analysis revealed a significant increase in eNOS phosphorylation at the inhibitory residue Thr495 in arteries exposed to periadventitial adipose tissue. This site-specific phosphorylation of eNOS was prevented by the inhibition of PKC-β. These data demonstrate that periadventitial adipose-derived factors impair coronary endothelial nitric oxide production via a PKC-β-dependent, site-specific phosphorylation of eNOS at Thr495.
Airway hyperresponsiveness is associated with activated CD4+ T cells in the airways
Authors: Zosky Graeme R. , Larcombe Alexander N. , White Olivia J. , Burchell Jennifer T. , von Garnier Christophe , Holt Patrick G. , Turner Debra J. , Wikstrom Matthew E. , Sly Peter D. , Stumbles Philip A.
Published: May 2009

It is widely accepted that atopic asthma depends on an allergic response in the airway, yet the immune mechanisms that underlie the development of airway hyperresponsiveness (AHR) are poorly understood. Mouse models of asthma have been developed to study the pathobiology of this disease, but there is considerable strain variation in the induction of allergic disease and AHR. The aim of this study was to compare the development of AHR in BALB/c, 129/Sv, and C57BL/6 mice after sensitization and challenge with ovalbumin (OVA). AHR to methacholine was measured using a modification of the forced oscillation technique in anesthetized, tracheostomized mice to distinguish between airway and parenchymal responses. Whereas all strains showed signs of allergic sensitization, BALB/c was the only strain to develop AHR, which was associated with the highest number of activated (CD69+) CD4+ T cells in the airway wall and the highest levels of circulating OVA-specific IgG1. AHR did not correlate with total or antigen-specific IgE. We assessed the relative contribution of CD4+ T cells and specific IgG1 to the development of AHR in BALB/c mice using adoptive transfer of OVA-specific CD4+ T cells from DO11.10 mice. AHR developed in these mice in a progressive fashion following multiple OVA challenges. There was no evidence that antigen-specific antibody had a synergistic effect in this model, and we concluded that the number of antigen-specific T cells activated and recruited to the airway wall was crucial for development of AHR.
Inadequate Training in Billing and Coding as Perceived by Recent Pediatric Graduates
Authors: Andreae Margie C. , Dunham Kelly , Freed Gary L.
Published: May 2009

Introduction. The literature supports a high rate of error in physician coding for professional services, suggesting that residency training in this area is inadequate to meet the needs in clinical practice. Method. From the American Board of Pediatrics database of recent graduates, 1200 generalists and 1100 subspecialists were selected to receive a structured questionnaire. Participants rated the adequacy of their training in billing and coding using 3 choices. Results. The response rate was 76% among the generalists and 77% among the subspecialists. Eighty-one percent of generalists (N = 549) and 78% (N = 423) of subspecialists indicated that they could have used additional training in billing and coding. This finding was common throughout all practice settings. Conclusions. Pediatric residency training programs are not meeting the needs of generalist or subspecialist physicians in training of billing and coding. Residency programs must enhance this training component to prepare physicians to maintain a financially viable practice.
In Wittgenstein’s Shadow
Authors: Agassi Joseph
Published: May 2009

Marc Lange offers a stale anthology that reflects the sad state of affairs in the camp of analytic philosophy. It is representative in a few respects, even in its maltreatment of Russell, Wittgenstein, and Popper. Despite its neglect of Wittgenstein, it shows again that Wittgenstein is the patron saint of the analytic school despite the fact that it does not abide by his theory of metaphysics as inherently meaningless.
Military Intelligence as the National Intelligence Estimator: The Case of Israel
Authors: Bar-Joseph Uri
Published: May 2009

Although Israel constitutes an interesting case for the study of civil—military relations, the role played by its Directory of Military Intelligence (AMAN) has rarely been discussed in this context. This role is of special interest, since Israel is the only liberal democracy today in which a military intelligence service functions as the leading national estimator not only in military but also in civilian affairs. The unique Israeli model is usually justified by Israel’s security concerns—primarily the threat of a sudden conventional attack. To test this model’s validity, this article (1) traces and elucidates its historical development; (2) employs five crucial mini case studies to test its practical success or failure; and (3) explains how, in light of the fact that AMAN failed in four of the five cases, its military characteristics create inherent weaknesses that hamper its ability to serve as a high-quality national intelligence estimator.
A randomized controlled trial to compare two botulinum toxin injection techniques on the functional improvement of the leg of children with cerebral palsy
Authors: Kaishou Xu  , Tiebin Yan  , Jianning Mai
Published: May 2009

Objective: To compare the efficacy of botulinum toxin type A injection guided by different localizing techniques, electrical stimulation and palpation, to treat spasticity of the ankle plantar flexors.

Design: Randomized controlled trial.

Setting: Hospital neurology and rehabilitation department.

Participants: Sixty-five children with spastic hemiplegic or diplegic cerebral palsy.

Interventions: Botulinum toxin injection guided by electrical stimulation or palpation, and two weeks of physiotherapy.

Main outcome measures: Passive range of movement (ROM), modified Ashworth Scale, Composite Spasticity Scale, D and E dimensions of the Gross Motor Function Measure, walking velocity.

Results: Three groups improved significantly (P<50.05). The mean improvements between baseline and the end of follow-up were respectively 20, 16.2 and 11.9 degrees for passive ROM, —1.9, —1.4 and —0.7 for modified Ashworth Scale scores, —5.8, —4.2 and —2.3 for Composite Spasticity Scale scores, 18.6, 11.3 and 6.9 for Gross Motor Function Measure scores, and 0.2, 0.1 and 0.1 m/s for walking velocity in the botulinum toxin group guided by electrical stimulation injection plus physiotherapy, the botulinum toxin group guided by palpation injection plus physiotherapy, and the physiotherapy only group. The botulinum toxin injection guided by electrical stimulation group showed greater improvement in passive ROM (P<50.05), modified Ashworth Scale scores (P<50.05), Composite Spasticity Scale scores (P<50.05), and Gross Motor Function Measure scores (P<50.05) than the other two groups after treatment for three months.

Conclusions: Botulinum toxin injection guided by electrical stimulation plus physiotherapy is likely to be best in improving spasticity and functional performance in children with cerebral palsy.
Promoting the Social and Communicative Behavior of Young Children With Autism Spectrum Disorders
Authors: Meadan Hedda , Ostrosky Michaelene M. , Zaghlawan Hasan Y. , Yu SeonYeong
Published: May 2009

The purpose of this article is to critically review the literature on parent-implemented interventions aimed at promoting and enhancing the social and communicative behavior of young children with autism spectrum disorders. Twelve parent-implemented intervention studies that were conducted, at least in part, in home environments and were published between 1997 and 2007 were identified. Each of these studies is described as a study within a study. A study-within-a-study design allows researchers to examine (a) the effectiveness of the parents' implementation of the newly learned strategies and (b) the influence of parent-implemented strategies on their children's social and communication skills. All 12 studies reported positive outcomes for parents and children. Yet closer examination of the research methods used in each study indicates considerable variability in intervention and data collection strategies. Carefully and critically evaluating this empirical literature can help researchers, teacher educators, and practitioners as they consider options for interventions and plan future research efforts that will efficiently and effectively result in positive outcomes for young children with social communication delays. Implications for research and practice are addressed following the literature review.
Effects of Transverse and Frontal Plane Knee Laxity on Hip and Knee Neuromechanics during Drop Landings
Authors: Shultz Sandra J. , Schmitz Randy J.
Published: May 2009

Background

Varus-valgus (LAXVV) and internal-external (LAXIER) rotational knee laxity have received attention as potential contributing factors in anterior cruciate ligament injury. This study compared persons with above- and below-average LAXVV and LAXIER values on hip and knee neuromechanics during drop jump landings.

Hypothesis

People with greater LAXVV and LAXIER values will have greater challenges controlling frontal and transverse plane knee motions, as evidenced by greater joint excursions, joint moments, and muscle activation levels during the landing phase.

Study Design

Descriptive laboratory study.

Methods

Recreationally active participants (52 women and 44 men) between 18 and 30 years old were measured for LAXVV and LAXIER and for their muscle activation and transverse and frontal plane hip and knee kinetics and kinematics during the initial landing phase of a drop jump. The mean value was obtained for each sex, and those with above-average values on LAXVV and LAXIER (LAXHIGH = 17 women, 16 men) were compared with those with below-average values (LAXLOW = 18 women, 17 men).

Results

Women with LAXHIGH verus LAXLOW were initially positioned in greater hip adduction and knee valgus and also produced more prolonged internal hip adduction and knee varus moments as they moved toward greater hip adduction and internal rotation as the landing progressed. These patterns in LAX HIGH women were accompanied by greater prelanding and postlanding muscle activation amplitudes. Men with LAXHIGH versus LAXLOW also demonstrated greater hip adduction motion and produced greater internal hip internal rotation and knee varus and internal rotation moments.

Conclusion

Participants with greater LAXVV and LAXIER landed with greater hip and knee transverse and frontal plane hip and knee motions.

Clinical Relevance

People (especially, women) with increased frontal and transverse plane knee laxity demonstrate motions associated with noncontact anterior cruciate ligament injury mechanisms.
Task-shifting HIV counselling and testing services in Zambia: the role of lay counsellors
Authors: Sanjana Parsa , Torpey Kwasi , Schwarzwalder Alison , Simumba Caroline , Kasonde Prisca , Nyirenda Lameck , Kapanda Paul , Kakungu-Simpungwe Matilda , Kabaso Mushota , Thompson Catherine
Published: May 2009

Background

The human resource shortage in Zambia is placing a heavy burden on the few health care workers available at health facilities. The Zambia Prevention, Care and Treatment Partnership began training and placing community volunteers as lay counsellors in order to complement the efforts of the health care workers in providing HIV counselling and testing services. These volunteers are trained using the standard national counselling and testing curriculum. This study was conducted to review the effectiveness of lay counsellors in addressing staff shortages and the provision of HIV counselling and testing services.

Methods

Quantitative and qualitative data were collected by means of semistructured interviews from all active lay counsellors in each of the facilities and a facility manager or counselling supervisor overseeing counseling and testing services and clients. At each of the 10 selected facilities, all counselling and testing record books for the month of May 2007 were examined and any recordkeeping errors were tallied by cadre. Qualitative data were collected through focus group discussions with health care workers at each facility.

Results

Lay counsellors provide counselling and testing services of quality and relieve the workload of overstretched health care workers. Facility managers recognize and appreciate the services provided by lay counsellors. Lay counsellors provide up to 70% of counselling and testing services at health facilities. The data review revealed lower error rates for lay counsellors, compared to health care workers, in completing the counselling and testing registers.

Conclusion

Community volunteers, with approved training and ongoing supervision, can play a major role at health facilities to provide counselling and testing services of quality, and relieve the burden on already overstretched health care workers.
Adverse environmental conditions influence age-related innate immune responsiveness
Authors: May Linda , van den Biggelaar Anita HJ , van Bodegom David , Meij Hans J , de Craen Anton JM , Amankwa Joseph , Frölich Marijke , Kuningas Maris , Westendorp Rudi GJ
Published: May 2009

Background-

The innate immune system plays an important role in the recognition and induction of protective responses against infectious pathogens, whilst there is increasing evidence for a role in mediating chronic inflammatory diseases at older age. Despite indications that environmental conditions can influence the senescence process of the adaptive immune system, it is not known whether the same holds true for the innate immune system. Therefore we studied whether age-related innate immune responses are similar or differ between populations living under very diverse environmental conditions.

Methods-

We compared cross-sectional age-related changes in ex vivo innate cytokine responses in a population living under affluent conditions in the Netherlands (age 20–68 years old, n = 304) and a population living under adverse environmental conditions in Ghana (age 23–95 years old, n = 562).

Results-

We found a significant decrease in LPS-induced Interleukin (IL)-10 and Tumor Necrosis Factor (TNF) production with age in the Dutch population. In Ghana a similar age-related decline in IL-10 responses to LPS, as well as to zymosan, or LPS plus zymosan, was observed. TNF production, however, did not show an age-associated decline, but increased significantly with age in response to co-stimulation with LPS and zymosan.

Conclusion-

We conclude that the decline in innate cytokine responses is an intrinsic ageing phenomenon, while pathogen exposure and/or selective survival drive pro-inflammatory responses under adverse living conditions.
Compressive simultaneous full-waveform simulation
Authors: Herrmann Felix J. , Erlangga Yogi A. , Lin Tim T.
Published: May 2009

The fact that the computational complexity of wavefield simulation is proportional to the size of the discretized model and acquisition geometry and not to the complexity of the simulated wavefield is a major impediment within seismic imaging. By turning simulation into a compressive sensing problem, where simulated data are recovered from a relatively small number of independent simultaneous sources, we remove this impediment by showing that compressively sampling a simulation is equivalent to compressively sampling the sources, followed by solving a reduced system. As in compressive sensing, this reduces sampling rate and hence simulation costs. We demonstrate this principle for the time-harmonic Helmholtz solver. The solution is computed by inverting the reduced system, followed by recovering the full wavefield with a program that promotes sparsity. Depending on the wavefield’s sparsity, this approach can lead to significant cost reductions, particularly when combined with the implicit preconditioned Helmholtz solver, which is known to converge even for decreasing mesh sizes and increasing angular frequencies. These properties make our scheme a viable alternative to explicit time-domain finite differences.
The continued value of clinical and radiological surveillance
Authors: Ollivere B. , Darrah C. , Brankin R. C. , Donnell S. T. , Walton N. P.
Published: May 2009

We report the follow-up at 12 years of the use of the Elite Plus total hip replacement (THR). We have previously reported the results at a mean of 6.4 years. Of the 217 patients (234 THRs), 83 had died and nine had been lost to follow-up. The patients were reviewed radiologically and clinically using the Oxford hip score.

Of the 234 THRs, 19 (8.1%) had required a revision by the final follow-up in all but one for aseptic loosening. Survivorship analysis for revision showed a survival of 93.9% (95% confidence interval (CI) 89.2 to 96.5) at ten years, and of 88.0% (95% CI 81.8 to 92.3) at 12 years. At the final follow-up survival analysis showed that 37% (95% CI 37.3 to 44.7) of the prostheses had either failed radiologically or had been revised. Patients with a radiologically loose femoral component had a significantly poorer Oxford hip score than those with a well-fixed component (p = 0.03). Radiological loosening at 6.4 years was predictive of failure at 12 years.

Medium-term radiographs and clinical scores should be included in the surveillance of THR to give an early indication of the performance of specific implants.
The painful metal-on-metal hip resurfacing
Authors: Hart A. J. , Sabah S. , Henckel J. , Lewis A. , Cobb J. , Sampson B. , Mitchell A. , Skinner J. A.
Published: May 2009

We carried out metal artefact-reduction MRI, three-dimensional CT measurement of the position of the component and inductively-coupled plasma mass spectrometry analysis of cobalt and chromium levels in whole blood on 26 patients with unexplained pain following metal-on-metal resurfacing arthroplasty.

MRI showed periprosthetic lesions around 16 hips, with 14 collections of fluid and two soft-tissue masses. The lesions were seen in both men and women and in symptomatic and asymptomatic hips. Using three-dimensional CT, the median inclination of the acetabular component was found to be 55° and its positioning was outside the Lewinnek safe zone in 13 of 16 cases. Using inductively-coupled plasma mass spectrometry, the levels of blood metal ions tended to be higher in painful compared with well-functioning metal-on-metal hips.

These three clinically useful investigations can help to determine the cause of failure of the implant, predict the need for future revision and aid the choice of revision prostheses.
The impact of stereo-visualisation of three-dimensional CT datasets on the inter- and intraobserver reliability of the AO/OTA and Neer classifications in the assessment of fractures of the proximal humerus
Authors: Brunner A. , Honigmann P. , Treumann T. , Babst R.
Published: May 2009

We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification.

These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus.
Fractures of the odontoid in children with an open basilar synchondrosis
Authors: Hosalkar H. S. , Greenbaum J. N. , Flynn J. M. , Cameron D. B. , Dormans J. P. , Drummond D. S.
Published: May 2009

Fractures of the odontoid in children with an open basilar synchondrosis differ from those which occur in older children and adults. We have reviewed the morphology of these fractures and present a classification system for them.

There were four distinct patterns of fracture (types IA to IC and type II) which were distinguished by the site of the fracture, the degree of displacement and the presence or absence of atlantoaxial dislocation. Children with a closed synchondrosis were classified using the system devised by Anderson and D’Alonzo. Those with an open synchondrosis had a comparatively lower incidence of traumatic brain injury, a higher rate of missed diagnosis and a shorter mean stay in hospital. Certain subtypes (type IA and type II) are likely to be missed on plain radiographs and therefore more advanced imaging is recommended. We suggest staged treatment with initial stabilisation in a Halo body jacket and early fusion for those with unstable injuries, severe displacement or neurological involvement.
Haematogenous infection of a resurfacing hip replacement after transurethral resection of the prostate
Authors: Dabasia H. , Kokkinakis M. , El-Guindi M.
Published: May 2009

A 66-year-old man presented with an infected resurfacing hip replacement in the immediate post-operative period following an uneventful transurethral resection of the prostate. Prophylactic antibiotics had been administered on induction of anaesthesia. The hip prosthesis had been inserted seven years previously and had been hitherto asymptomatic. The hip was washed out and microbiological examination identified Enterococcus faecalis as the infecting micro-organism.

Despite current recommendations, clinicians undertaking invasive procedures which can lead to bacteraemia in patients with prosthetic joint replacements should be aware of the risk of haematogenous seeding in such prostheses, which although low, has potentially disastrous consequences.
A Collective Response to Michael White's Passing
Authors: Boylan Janette , Grainger‐Dee Tosca , Innes Tricia , Johnston Sally , Shannon Linda , Subramaniam Prathiba , Szekely Sari
Published: May 2009

The following reflection was written at the Cairns Narrative Therapy Interest Group shortly after Michael White's passing. As a group activity, each individual was interviewed about the effects of Michael White's work on their therapeutic work. Each of the responses were manually recorded and then a member of the group developed the collective document to share back with the whole group. The document was a way to capture the atmosphere that was shared at the interest group that day upon reflection of Michael. The document also enables a way to remember the influence that a collective document can produce for a group of people.
Some Reflections on the Legacies of Michael White: An Australian Perspective
Authors: Denborough David
Published: May 2009

This article, which appears in a special 30‐year anniversary edition of the Australian and New Zealand Journal of Family Therapy, reflects on the legacies of the work of Michael White. It begins by looking back on Michael's time as editor of the Australian Journal of Family Therapy. Of the many themes that were discussed in the Editorials and Letters to the Editor section of this journal in the early 1980s, this article focuses on three in particular to explore the legacies of the work of Michael White. The author describes how Michael has bequeathed not only a profound body of work, but also a distinctive spirit of originating, and ways of working that consider the effects of social issues and that examine the politics of experience. It is the author's hope that this approach to considering Michael White's legacies honours his work and also honours the contributions of the Australian and New Zealand Journal of Family Therapy in its 30th year.