bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing the Areas Under Two Correlated ROC Curves: Parametric and Non‐Parametric Approaches
Authors: Molodianovitch Katy , Faraggi David , Reiser Benjamin
Published: May 2006

In order to compare the discriminatory effectiveness of two diagnostic markers the equality of the areas under the respective Receiver Operating Characteristic Curves is commonly tested. A non‐parametric test based on the Mann‐Whitney statistic is generally used. Weiand et al. (1989) present a parametric test based on normal distributional assumptions. We extend this test using the Box‐Cox power family of transformations to non‐normal situations. These three test procedures are compared in terms of significance level and power by means of a large simulation study. Overall we find that transforming to normality is to be preferred. An example of two pancreatic cancer serum biomarkers is used to illustrate the methodology. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recombinant interferon γ1b immune enhancement in 20 patients with hematologic malignancies and systemic opportunistic infections treated with donor granulocyte transfusions
Authors: Safdar Amar , Rodriguez Gilhen H. , Lichtiger Benjamin , Dickey Burton F. , Kontoyiannis Dimitrios P. , Freireich Emil J. , Shpall Elizabeth J. , Raad Issam I. , Kantarjian Hagop M. , Champlin Richard E.
Published: May 2006

BACKGROUND

The response to antifungal therapy alone often is suboptimal in patients with cancer who have therapy‐refractory neutropenia, and even donor‐derived granulocyte transfusions (GTX) are not always successful. The authors evaluated the safety and efficacy of immune enhancement using recombinant interferon γ1b (rIFN‐γ1b) in patients with cancer who received GTX for refractory, systemic, opportunistic infections.

METHODS

Twenty recipients of high‐dose donor GTX (≈5.5 × 1010 neutrophils per transfusion) who had received concurrent rIFN‐γ1b between October 2001 and December 2004 were evaluated retrospectively.

RESULTS

The median age (± standard deviation [SD]) was 45 ± 17 years. Ten patients (50%) were men, 17 patients (85%) had leukemia, and 3 patients (15%) had myelodysplastic syndrome. The median ± SD Acute Physiology and Chronic Health Evaluation II score was 15 ± 4 (range, 7‐22). Most patients (n = 18 patients; 90%) had recurrent or refractory cancer. In 6 patients (30%) who received allogeneic hematopoietic stem cell transplantation, GTX plus rIFN‐γ1b was given a median ± SD of 26 ± 100 days (range, 12‐372 days) after transplantation. Seventeen patients (85%) had neutropenia during GTX therapy. Five patients (25%) had possible invasive fungal infection, 3 patients (15%) had probable invasive fungal infection, and 11 patients (55%) had proven invasive fungal infection. One patient (5%) had refractory Pseudomonas aeruginosa sepsis. Eight patients (40%) received corticosteroids during GTX plus rIFN‐γ1b therapy. Patients received a median ± SD of 8 ± 7 GTX doses (range, 4‐28 doses) and 9 ± 7 rIFN‐γ1b doses (range, 1‐28 doses), for a mean ± SD cumulative dose (CD) of 400 ± 2621 μg. Other concomitant cytokines were granulocyte‐colony stimulating factor (12 ± 3 doses; CD, 6720 ± 4721 μg) in 15 patients (75%) and granulocyte‐macrophage–colony stimulating factor (12 ± 9 doses; CD, 4750 ± 4410 μg) in 14 patients (70%). Four patients (20%) developed fever, and 2 patients (10%) developed skin rashes. Reversible liver dysfunction (n = 3 patients; 15%) and tachycardia (n = 1 patients; 5%) were considered rIFN‐γ1b‐associated adverse reactions; whereas, in 1 patient (5%), transient dyspnea was attributed to GTX. Four weeks after therapy started, 9 patients (45%) had complete or partial resolution of infection; and, in another 3 patients (15%), the invasive fungal infection had become stable.

CONCLUSIONS

The current results indicated that no serious adverse events were associated with rIFN‐γ1b immune enhancement in patients with systemic opportunistic infections who received donor GTX therapy. Cancer 2006. © 2006 American Cancer Society.
Developing LHCb Grid software: experiences and advances
Authors: Stokes‐Rees I. , Tsaregorodtsev A. , Garonne V. , Graciani R. , Sanchez M. , Frank M. , Closier J.
Published: May 2006

The LHCb Grid software has been used for two Physics Data Challenges, with the latter producing over 98 TB of data and consuming over 650 processor‐years of computing power. This paper discusses the experience of developing a Grid infrastructure, interfacing to an existing Grid (LCG) and traditional computing centres simultaneously, running LHCb experiment software and jobs on the Grid, and the integration of a number of new technologies into the Grid infrastructure. Our experience and utilization of the following core technologies will be discussed: OGSI, XML‐RPC, Grid services, LCG middleware and instant messaging. Specific attention will be given to analysing the behaviour of over 100 000 jobs executed through the LCG Grid environment, providing insight into the performance, failure modes and scheduling efficiency over a period of several months for a large computational Grid incorporating over 40 sites and thousands of nodes. © Crown copyright 2006. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Performance and effectiveness trade‐off for checkpointing in fault‐tolerant distributed systems
Authors: Katsaros Panagiotis , Angelis Lefteris , Lazos Constantine
Published: May 2006

Checkpointing has a crucial impact on systems' performance and fault‐tolerance effectiveness: excessive checkpointing results in performance degradation, while deficient checkpointing incurs expensive recovery. In distributed systems with independent checkpoint activities there is no easy way to determine checkpoint frequencies optimizing response‐time and fault‐tolerance costs at the same time. The purpose of this paper is to investigate the potentialities of a statistical decision‐making procedure. We adopt a simulation‐based approach for obtaining performance metrics that are afterwards used for determining a trade‐off between checkpoint interval reductions and efficiency in performance. Statistical methodology including experimental design, regression analysis and optimization provides us with the framework for comparing configurations, which use possibly different fault‐tolerance mechanisms (replication‐based or message‐logging‐based). Systematic research also allows us to take into account additional design factors, such as load balancing. The method is described in terms of a standardized object replication model (OMG FT‐CORBA), but it could also be applied in other (e.g. process‐based) computational models. Copyright © 2006 John Wiley & Sons, Ltd.
Nanobiotechnology: it's a small world after all
Authors: Moos Walter H. , Barry Stephen
Published: May 2006

Nanobiotechnology is the latest technology to provide disruptive—quantum leap—opportunities in drug development research. Examples of the utility of this approach are found increasingly in the scientific literature and the lay press. Whether for therapeutics, diagnostics, drug delivery, targeting, or some other product category, the potential for nanotechnology to revolutionize medicine is quite high. A number of organizations have chosen to focus their nanotechnology efforts on cancer. This is an exciting area that should benefit from an increasing number of collaborations of interdisciplinary experts to fabricate and characterize novel and enabling nanoparticulate technologies. Drug Dev. Res. 67:1–3, 2006.
Amphiphilic block copolymer micelles for nanoscale drug delivery
Authors: Kwon Glen S. , Forrest M. Laird
Published: May 2006

Amphiphilic block copolymers can assemble into supramolecular core‐shell structures, termed ABC micelles, that have proven utility in drug delivery, particularly for drug solubilization. Several examples have entered clinical trials, attesting to the biocompatibility of ABCs and the potential advantages for drug delivery, e.g., low toxicity relative to Cremophor® EL, a surfactant commonly used for drug solubilization. Several examples of ABC micelles demonstrate potential for prolonged circulation in blood. Coupled with novel strategies toward controlled release of drug, nanoscale ABC micelles have tremendous potential for the targeting of antitumor agents, many of which are poorly water soluble and possess dose‐limiting toxicity. Drug Dev. Res. 67:15–22, 2006. © 2006 Wiley‐Liss, Inc.
Colloidal gold nanoparticles: a novel nanoparticle platform for developing multifunctional tumor‐targeted drug delivery vectors
Authors: Paciotti Giulio F. , Kingston David G.I. , Tamarkin Lawrence
Published: May 2006

Nanotechnology applied to biological problems represents an emerging field with the potential to offer extremely sensitive diagnostics and targeted cancer therapies. However, to achieve these goals, nanoparticle delivery systems must outwit the many barriers that are intrinsic to the body's defenses, as well as those that develop during the growth and progression of tumors. The science is advancing and, for example, true nanoscale tumor‐targeted drug delivery vectors are now able to reduce the likelihood of opsonization in the bloodstream and uptake by the reticuloendothelial system. Other advances hold promise for delivering multiple therapeutic agents to non‐homogeneous populations of cancer cells in solid tumors. We briefly summarize herein our attempts to build such multifunctional nanotherapeutics using colloidal gold nanoparticles. Specifically we discuss the development of colloidal gold‐based drugs that are designed to target the delivery of TNF and paclitaxel to solid tumors. Drug Dev. Res. 67:47–54, 2006. © 2006 Wiley‐Liss, Inc.
Discrete thermally responsive hydrogel‐coated gold nanoparticles for use as drug‐delivery vehicles
Authors: Kim Jun‐Hyun , Randall Lee T.
Published: May 2006

This report describes the development of optically responsive gold nanoparticles (∼60 nm in diameter) coated with a thermally responsive biocompatible hydrogel overlayer (20–90 nm thick). The hydrogel consists of a mixture of N‐isoproprylacrylamide and acrylic acid; this copolymer can be tailored to exhibit a lower critical solution temperature (LCST) slightly above physiological temperature. When the temperature is raised above the LCST, the hydrogel polymer shrinks dramatically; in contrast, when the temperature is lowered below the LCST, the hydrogel expands to a fully swollen structure. These hybrid nanoparticles were designed for the purpose of developing an optically modulated drug‐delivery system that responds to ambient changes in temperature. Specifically, drug‐impregnated hydrogel coatings can be photothermally activated by exposure to light that can be absorbed by the plasmon resonance of the gold nanoparticle cores. The studies described here demonstrate that these new hybrid core‐shell nanoparticles can be reproducibly prepared by surfactant‐free emulsion polymerization (SFEP) and that their structural responses to external stimuli are consistent with our objective of photothermal drug delivery. Drug Dev. Res. 67:61–69, 2006. © 2006 Wiley‐Liss, Inc.
Targeted molecular brachytherapy
Authors: Mayers George L.
Published: May 2006

A new approach for the treatment of solid tumor cancers that utilizes aspects of bionanotechnology to deposit a short‐lived radioisotope throughout the tumor mass is described. Selectively Targeted Amplified Radiotherapy (STAR) is a multi‐step therapy in which an insoluble nano‐platform is first built inside neoplastic cells from a soluble precursor. The nano‐platform is then released into the extra‐cellular space throughout the tumor by disruption of some of the neoplastic cells. The nano‐platform is constructed so that it can selectively attach a reagent incorporating an exogenous enzyme, thereby transforming the insoluble nano‐platform into a nano‐factory. Finally, the enzymatic activity of the nano‐factory is used to convert a soluble radioactive substrate into a water‐insoluble nano‐precipitate throughout the tumor. The remaining soluble radiochemical is cleared from the body while the radioactive nano‐precipitate remains throughout the tumor, irradiating the surrounding tumor cells and providing what can be called molecular brachytherapy. This report discusses how the STAR technology overcomes tumor heterogeneity and metastases, the two major obstacles to successful treatment of solid tumor cancers. Drug Dev. Res. 67:94–106, 2006. © 2006 Wiley‐Liss, Inc.
Bmp2 and Gata4 function additively to rescue heart tube development in the absence of retinoids
Authors: Ghatpande Satish , Brand Thomas , Zile Maija , Evans Todd
Published: May 2006

We used the vitamin A–deficient (VAD) quail model to investigate the retinoid‐dependent mechanism that regulates heart tube development. We showed previously that decreased levels of Gata4 in cardiogenic mesoderm and endoderm correlate with the cardiomyopathy caused by VAD, but that this could be rescued by transplanting normal anterior endoderm. Bmp2 is a known cardiogenic factor that is expressed normally in lateral plate mesoderm and cardiac‐associated pharyngeal endoderm. Here we show that (like Gata4) transcripts encoding Bmp2 and BMP‐dependent signaling activity are decreased throughout the heart‐forming region of the VAD embryo. Addition of Bmp2 protein or forced expression of Gata4 in cultured VAD embryos leads to a partial rescue of the cardiomyopathy, and addition of both Bmp2 and Gata4 has an additive positive effect. Our data are consistent with a requirement for retinoid signaling to maintain expression of Bmp2, which regulates Gata4, and in addition acts with Gata4 to regulate genes important for normal morphogenesis of the primitive heart tube. Developmental Dynamics 235:2030–2039, 2006. © 2006 Wiley‐Liss, Inc.
Attenuation of retinal vascular development and neovascularization in transgenic mice over‐expressing thrombospondin‐1 in the lens
Authors: Wu Zhifeng , Wang Shoujian , Sorenson Christine M. , Sheibani Nader
Published: May 2006

Thrombospondin‐1 (TSP1) is an endogenous inhibitor of angiogenesis and induces endothelial cell (EC) apoptosis. To study the role TSP1 plays during vascular development and neovascularization, we assessed the effects of ectopic TSP1 expression in the lens on retinal vascularization in transgenic mice. The TSP1 over‐expressing mice showed abnormalities in the development of retinal vasculature. There was a dramatic decrease in the density of superficial and deep vascular plexuses of the retina in transgenic mice. The retinal vessels in TSP1 transgenic mice also appeared nonuniform and abnormal in maturation. We detected an increase in the number of EC undergoing apoptosis, which was compensated, in part, by an increase in cell proliferation in retinal vasculature of TSP1 transgenic mice. The TSP1 transgenic mice also exhibited increased levels of vessel obliteration and a limited preretinal neovascularization during oxygen‐induced ischemic retinopathy (OIR). Our results indicate increased expression of TSP1 attenuates normal retinal vascularization and preretinal neovascularization during OIR. Therefore, modulation of TSP1 expression may provide an effective mechanism for regulation of ocular angiogenesis. Developmental Dynamics 235:1908–1920, 2006. © 2006 Wiley‐Liss, Inc.
Dicopper(II) Complexes with the Enantiomers of a Bidentate Chiral Reduced Schiff Base: Inclusion of Chlorinated Solvents and Chiral Recognition of1,2‐Dichloroethane Rotamers in the Crystal Lattice
Authors: Muppidi Vamsee Krishna , Pal Samudranil
Published: May 2006

Bisphenoxo‐bridged dicopper(II) complexes [Cu2Ln2Cl2] {1 (n = 1) and 2 (n = 2)} with the N,O‐donor reduced Schiff bases N‐(2‐hydroxybenzyl)‐(R)‐α‐methylbenzylamine (HL1) and N‐(2‐hydroxybenzyl)‐(S)‐α‐methylbenzylamine (HL2) have been synthesised and characterised. In both 1 and 2, the bidentate chiral ligands coordinate the metal centres through the secondary amine N atom and the bridging phenolate O atom. The chloride ion occupies the fourth coordination site and completes a slightly distorted square‐planar NO2Cl environment around each copper(II) centre. Magnetic susceptibility measurements in the solid state suggest a strong antiferromagnetic interaction between the metal centres in both complexes. Both 1 and 2 readily form 1:1 host‐guest compounds with chlorinated solvents such as CH2Cl2, CHCl3 and Cl(CH2)2Cl. All the host‐guest compounds crystallise in noncentrosymmetric space groups. 1·CH2Cl2 and 2·CH2Cl2 crystallise in the P21 space group while 1·CHCl3, 2·CHCl3, 1·Cl(CH2)2Cl and 2·Cl(CH2)2Cl crystallise in the P212121 space group. In these inclusion crystals, the C–H···Cl interactions between the guest and the host molecules are primarily responsible for enclatheration of the chloroalkane molecules. In the case of CH2Cl2, one of its Cl atoms acts as the acceptor. On the other hand, for CHCl3 and Cl(CH2)2Cl, the metal coordinated Cl atom of the host complex acts as the acceptor. The structures of 1·(P)‐Cl(CH2)2Cl and 2·(M)‐Cl(CH2)2Cl provide rare examples for chiral recognition of the right handed (P) and the left handed (M) gauche forms of Cl(CH2)2Cl in molecular assemblies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Anionic and Photochemical Behaviour of the Medium‐Sized Terpenoid Ketone 8‐Dehydro‐12‐O‐methyl‐deacylhallerin
Authors: Croce Gianluca , Milanesio Marco , Viterbo Davide , Clericuzio Marco , Ugliengo Piero , Appendino Giovanni
Published: May 2006

Treatment of the germacrane ketone 8‐dehydro‐12‐O‐methyl‐deacylhallerin (2) with bases under conditions of thermodynamic enolization resulted in complete epimerization at the adjacent carbon atom C‐7, with formation of 3. The conformational features of the epimeric ketones 2 and 3 were investigated by X‐ray crystal structure analysis, NMR spectroscopy, molecular mechanics and dynamics simulations and ab initio calculations. While 2 showed temperature‐insensitive sharp 1H NMR signals, its epimer 3 showed only broad lines. These spectral features suggest that 2 is monorotameric, while 3 is a mixture of different conformers, as was verified by molecular mechanics and dynamics calculations. Upon UV irradiation, 2 underwent isomerization at the C1–C10 double bond, while 3 was unreactive. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Duraprep and the risk of fire during tracheostomy
Authors: Weber Stephen M. , Hargunani Christopher A. , Wax Mark K.
Published: May 2006

Background.

DuraPrep is a widely used, alcohol‐based surgical prep solution. The risk of surgical fire associated with incomplete drying of this agent in the context of electrosurgical procedures has been described previously. To date, there have been no reports of fire during tracheostomy associated with a flammable prep agent before entering the airway. We describe an operating room fire occurring during awake tracheostomy associated with the use of DuraPrep.

Methods.

A 62‐year‐old man with copious body hair underwent tracheostomy in the operating room. The neck was prepared with DuraPrep surgical solution, and after at least 3 minutes, the operative field was draped. Activation of electrocautery ignited a fire, and the patient was burned on his neck and shoulders.

Results.

The fire was extinguished, and the patient recovered from both the tracheostomy and the burns.

Conclusion.

This case illustrates that DuraPrep should be avoided in the hirsute patient, because body hair interferes with drying of this solution and increases the risk of fire. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
Anion substitution in zinc chalcogenides
Authors: Jug Karl , Tikhomirov Viatcheslav A.
Published: May 2006

Anion substitution effects on the structure and energy of zinc chalcogenides were studied with the semiempirical molecular orbital method MSINDO. Cyclic clusters of different sizes were chosen as model systems. The convergence of the bulk properties of the perfect clusters with increasing cluster size was tested. Single and multiple substitution of oxygen atoms in zinc oxide by sulfur and of sulfur atoms in zinc sulfide by oxygen served to determine the energetics of substitution for these two cases. It was found that the substitution of oxygen by sulfur in ZnO is easier than the substitution of sulfur by oxygen in ZnS in agreement with experimental results. The interaction between two oxygen atoms vs. two selenium atoms in zinc sulfide was investigated. Oscillations of the cluster energy in dependence of the distance between the two doping atoms were observed. These are explained by the relative sites of the doping atoms in the crystal lattice. The magnitude of the oscillations is smaller in ZnS:Se than in ZnS:O, because the difference between the anion radii of S2‐ and Se2‐ is smaller than between S2‐ and O2‐. This is also reflected in the band gap. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1088–1092, 2006
The aftermath of disaster: Children in crisis
Authors: Gaffney Donna A.
Published: May 2006

This article uses examples from the terrorist attacks on the World Trade Center and the hurricane disasters of Katrina and Rita to illustrate the impact of crisis in the lives of children and adolescents. The author reviews children's responses to loss and crisis. Therapeutic approaches that facilitate integration of crisis and loss are provided, including illustrations of self‐care, comfort strategies, and developmental, traditional, and nontraditional methods. © 2006 Wiley Periodicals, Inc. J Clin Psychol: In Session 62: 1001–1016, 2006.
Quaternary corals from reefs in the Wakatobi Marine National Park, SE Sulawesi, Indonesia, show similar growth rates to modern corals from the same area
Authors: Crabbe M. James C. , Wilson Moyra E. J. , Smith David J.
Published: May 2006

We have used digital photography, image analysis and measurements in the field to determine the growth rates of Quaternary corals in the Wakatobi Marine National Park, Indonesia, and compared them to growth rates of similar corals in the same area. In the Quaternary deposits it was possible to measure the growth rates of two massive coral genera Porites and Favites. For each genus, the corals reworked from better‐illuminated upslope environments had higher growth rates than the in situ fossil corals. The calculated radial growth rates for the in situ Porites are slightly lower than, but of the same order of magnitude as, the modern Porites growing in 10 m water depth at Hoga (10.04 ± 3.34 mm yr−1 ± 1 s.d.; n = 3) and Kaledupa (15.26 ± 4.83 mm yr−1 ± 1 s.d.; n = 3).

Sedimentation rates and underwater visibility are inferred to have been similar in the fossil site to that at the modern Kaledupa site. Decreasing light penetration due to increased water depth is inferred to have been a major influence on growth rates. The in situ massive corals with good growth banding are inferred to have grown in a comparable environment to modern Kaledupa and Hoga. The study highlights that it is possible to compare coral growth rates, and their influencing parameters, from modern and well‐preserved ancient examples. Copyright © 2006 John Wiley & Sons, Ltd.
Covariation of corticospinal efficiency and silent period in motoneuron diseases
Authors: Attarian S. , Pouget J. , Schmied A.
Published: May 2006

For a better understanding of the changes affecting the cortically induced silent period (SP) in motoneuron disease, the excitatory and inhibitory effects of transcranial magnetic stimulation were explored repeatedly in 8 patients with amyotrophic lateral sclerosis (ALS), 3 patients with Kennedy's disease (KD), and 10 healthy subjects. In KD, the background electromyogram (EMG) and the motor evoked potential (MEP) area were both enhanced. However, neither the corticospinal efficiency (MEP gain, the ratio between MEP and background EMG) nor the duration of the SP differed from healthy subjects. In ALS patients, the MEP gain and the SP duration decreased conspicuously with time. We conclude that use of the MEP gain improves detection of corticospinal dysfunction in ALS patients. Part of the SP shortening in ALS seems to reflect the reduced activation of cortical or spinal inhibitory networks by the abnormal corticospinal pathway. Muscle Nerve, 2006
Birt–Hogg–Dubé gene mutations in human endometrial carcinomas with microsatellite instability
Authors: Fujii H , Jiang W , Matsumoto T , Miyai K , Sashara K , Ohtsuji N , Hino O
Published: May 2006

Birt–Hogg–Dubé (BHD) syndrome is a rare form of autosomal dominantly inherited genodermatosis characterized by benign hamartomatous skin lesions named fibrofolliculomas, and an increased risk for developing pulmonary cyst/pneumothorax and various forms of renal cell carcinoma. Many of the patients harbour insertion/deletion mutations in the hypermutable poly(C)8 tract in exon 11 of the BHD gene. This mutational hot spot is also reported to be a target of mutation in microsatellite instability (MSI) sporadic colorectal cancer. To test the hypothesis that the BHD gene is also a mutational target in sporadic endometrial carcinoma with microsatellite instability, 139 cases of sporadic endometrial carcinoma were screened for MSI status, and mutations of the poly(C)8 tract in exon 11 as well as other coding exons of the BHD gene. The poly(G)8 tract of the BAX gene, the poly(C)8 tract of MSH6, and methylation status of hMLH1 were also assessed. Thirty‐nine of 139 cases (28%) showed MSI. Mutations in the poly(C)8 tract of BHD were detected in five of the 39 MSI cases (12.8%). Of these, one showed additional mutation in exon 4, possibly satisfying the two‐hit hypothesis of tumour suppressor genes. BAX gene mutation was detected in ten of the 39 MSI cases (25.6%). Four tumours showed both BAX and BHD mutations, and a significant positive association was found between mutations of the two genes. No association was found between BHD status and MSH6 mutation or hMLH1 methylation. When multiple foci were microdissected and individually screened for mutation, BHD mutations were shown to have been acquired during tumour progression, after mutation of the BAX gene, in three of five cases. Taken together, these findings show that the BHD gene is a target gene in MSI endometrial carcinoma. However, its mutational frequency is lower than that of BAX, and BHD mutation tends to occur during neoplastic progression after the acquisition of mutations in another MSI target gene, BAX. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Bilateral germinoma of the basal ganglia
Authors: Rossi Andrea , Garrè Maria Luisa , Ravegnani Marcello , Nozza Paolo , Abbruzzese Arturo , Giangaspero Felice , Tortori‐Donati Paolo
Published: May 2006

Germinoma arising in the bilateral basal ganglia is exceedingly rare, with only five cases reported to date. Owing to non‐specific clinical findings and the frequent presence of ill‐defined abnormalities without a definite tumor mass on neuroimaging, the diagnosis can be difficult. We describe a case in which magnetic resonance spectroscopy (MRS) findings suggested a tumor and supported the decision to perform biopsy of the lesion. Pediatr Blood Cancer 2008;50:177–179. © 2006 Wiley‐Liss, Inc.
The magnesium acceptor states in GaN: an investigation by optically‐detected magnetic resonance
Authors: Aliev G. N. , Zeng S. , Davies J. J. , Wolverson D. , Bingham S. J. , Parbrook P. J. , Wang T.
Published: May 2006

We observe a systematic dependence of the g ‐values of magnesium acceptors on the photoluminescence energy that is used for the optical detection of magnetic resonance signals. This effect leads to a model which assumes that, in the magnesium acceptors, the hole is located in an atomic orbital of p ‐character, presumed to be on a nitrogen atom, and which, in the wurtzite crystal field, is an orbital doublet. The remaining degeneracy is then removed by a reduction in local symmetry associated with the relative positions of the magnesium dopant and the nitrogen atom upon which the hole is localized. Further changes in the local crystal field are caused by the presence of nearby defects or by strain and are accompanied by changes in acceptor depth. The model leads to the correct g ‐values and the correct correlation between the g ‐values and acceptor depth and is consistent with a range of acceptor states of different depths being formed by simple substitution of a magnesium ion at a gallium site. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduction of strain and dislocation defects in GaN layers grown on Si substrate by MOCVD using a substrate defect engineering technique
Authors: Jamil M. , Irissou Eric , Grandusky J. R. , Jindal V. , Shahedipour‐Sandvik F.
Published: May 2006

We report on the application of a new scheme of substrate engineering in Si (111) substrate to obtain high quality GaN layers on Si substrates. An ion implanted defective layer is formed in the Si substrate that partially, crystallographically and mechanically isolates the III‐Nitride layer and Si substrate which results in reduction of strain in the Nitride film. Nitrogen ion implantation energies of 60‐75 keV and ion doses of 1×1016 cm–2‐2×1016 cm–2 were applied to AlN buffer layers of 55 nm thick grown on Si (111). The experimental results show an increase in the crack separation of over 1 mm for 2 µm thick GaN film grown on implanted 55 nm AlN/Si complex substrate as seen under optical microscope. Moreover the GaN films grown on implanted AlN/Si substrate showed smoother surface morphology (RMS roughness of 0.41 nm) as compared to that grown on non‐implanted AlN/Si substrates (RMS roughness of 1.50 nm). Results of etch pit density and XRD measurements show significant reduction in dislocations in III‐Nitride layers. Our data shows a strong dependence of GaN quality on the implantation conditions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of pit‐defect free smooth a‐plane GaN surfaces on r‐plane sapphire using metalorganic chemical vapor deposition: A growth mechanism study
Authors: Jindal Vibhu , Grandusky James , Jamil Muhammad , Irissou Eric , Shahedipour Sandvik Fatemeh , Matocha Kevin , Tilak Vinayak
Published: May 2006

We report on development of smooth a‐plane GaN without the use of lateral epitaxial overgrowth. Effects of GaN buffer growth conditions, namely V/III ratio and temperature, on the quality of high temperature a‐plane GaN layers on r‐plane sapphire substrates have been studied. Optimization of the buffer growth conditions resulted in surfaces of 2 µm thick overgrown a‐plane GaN at high temperature with less pit defects, the presence of which is reported as a common occurrence for a‐plane GaN grown on r‐plane sapphire. The surfaces were smooth with RMS roughness of less than 2 nm for a 5 µm x 5 µm AFM scanning area. We will present the effect of V/III ratio in low temperature buffer growth and qualitative growth mechanism model that has been constructed based on the structural and morphological study of the layers grown at various stages. Layers were characterized using AFM, SEM, and HRXRD. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication and characterization of 20 periods InN/InGaN MQWs
Authors: Che Song‐Bek , Ishitani Yoshihiro , Yoshikawa Akihiko
Published: May 2006

20 periods InN/In0.75–0.80Ga0.25–0.20N MQWs were fabricated on In0.75–0.80Ga0.25–0.20N underlayers by radio frequency plasma‐assisted molecular‐beam epitaxy. Fine periodic MQWs structures were confirmed by X‐ray 2θ–ω scans, which showed clear satellite peaks up to 2nd order. From reciprocal space mappings for (10‐14) diffraction, it was found that the InGaN underlayer completely relaxed for all MQWs samples, and when the InN well thickness was 2.2 nm or less, the MQWs could be coherently grown on the InGaN underlayer. In PL measurement at 15 K, near‐infrared emissions from the MQWs were observed. With decreasing the InN well thickness from 18.7 nm to 2.2 nm, the emission peak shifted to 1.63 µm. This result indicates a quantum confinement effect in the InN/InGaN MQWs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical characteristics of two‐dimensional electrons in single and multiple AlxGa1–xN/GaN heterostructures grown by metalorganic chemical vapor deposition
Authors: Kim Sun‐Mo , Kwack Ho‐Sang , Hwang Sun‐Woong , Cho Yong‐Hoon , Cho H. I. , Lee J. H. , Wang Kang L.
Published: May 2006

The optical properties of two‐dimensional electron gas (2DEG) in single and multiple AlxGa1–xN/GaN heterostructures were investigated by means of photoluminescence (PL), temperature dependent PL, power dependent PL. A strong GaN band edge emission and its longitudinal optical (LO) phonon replicas were observed for all the samples. The PL peaks related to recombination between the 2DEG and photogenerated hole are observed at ∼3.45 eV for single AlxGa1–xN/GaN heterostructures and at ∼3.425 and ∼3.45 eV for multiple AlxGa1–xN/GaN heterostructures. The LO phonon replicas of the 2DEG emission were also clearly observed. The 2DEG‐related emission intensity decreased with increasing temperature and disappeared at temperatures above 150 K. A possible origin of the appearance of 2DEG‐related emissions in single and multiple AlGaN/GaN heterostructures has been discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reexamination of the cysteine residues in glucocerebrosidase
Authors: Moharram Ramy , Maynard Dawn , Wang Eric S. , Makusky Anthony , Murray Gary J. , Martin Brian M.
Published: May 2006

Glucocerebrosidase, the deficient enzyme in Gaucher disease, catalyzes the cleavage of the β‐glycosidic linkage of glucosylceramide. A previous study on the enzyme identified three disulfide bridges and a single sulfhydryl [Lee, Y., Kinoshita, H., Radke, G., Weiler, S., Barranger, J.A. and Tomich, J.M. (1995) Position of the sulfhydryl group and the disulfide bonds of human glucocerebrosidase. J. Protein Chem. 14(3), 127–137] but recent publication of the X‐ray structure identifies only two disulfide bridges with three free sulfhydryls [Dvir, H., Harel, M., McCarthy, A.A., Toker, L., Silman, I., Futerman, A.H. and Sussman, J.L. (2003) X‐ray structure of human acid‐β‐glucosidase, the defective enzyme in Gaucher disease. EMBO. 4(7), 704–709]. Using chemical modifications, acid cleavage and enzymatic digestion methods, we report that three free sulfhydryls exist and that the remaining four cysteines form two disulfide bonds located within the first 25 amino‐terminal residues, supporting the X‐ray structure.
Evidence for distinct functions for human DNA repair factors hHR23A and hHR23B
Authors: Chen Li , Madura Kiran
Published: May 2006

Rad23 proteins bind ubiquitinated substrates and the proteasome, consistent with an important role in protein degradation. Although human Rad23 proteins (hHR23A and hHR23B) have redundant roles in DNA repair, we determined they formed distinct interactions with proteasomes and multiubiquitinated proteins, but similar binding to Ataxin‐3. Threonine‐79 contributed to the weak proteasome‐binding property of hHR23A, and its conversion to proline (T79P), which is the residue present in hHR23B, increased proteasome interaction. We also determined that hHR23A and hHR23B could be co‐purified with unique proteolytic and stress‐responsive factors from human breast cancer tissues, indicating that they have unique functions in vivo.
Changes in the mesozooplankton community associated with the hydrography off the northwestern Iberian Peninsula
Authors: Blanco-Bercial Leocadio , Álvarez-Marqués Florentina , Cabal Jesús A.
Published: May 2006

Changes in the mesozooplankton community were investigated along the northwestern coast of the Iberian Peninsula during OMEX II cruises in August 1998, under upwelling conditions, and in October 1999, when there was a saline, warm poleward current flowing along the slope. Six stations, located at both the shelf break and in oceanic waters, were sampled for mesozooplankton by day and by night. Samples were grouped in accordance with their species abundance levels, and the resulting groups were compared with salinity, integrated chlorophyll a, and sea surface and average temperatures. The analysis discriminated stations from different cruises into different groups, and detected the influence of hydrographic structures. The abundance of species linked to high concentrations of Chl a and low temperature increased during the upwelling session, whereas species related to warmer water were more abundant during the 1999 cruise. Further, the analysis revealed differences in the mesozooplankton composition between coastal and oceanic sites, which were influenced to different degrees by the upwelling and the poleward current.
Long-term changes in zooplankton biomass concentration and mean size over the Northwest European shelf inferred from Continuous Plankton Recorder data
Authors: Pitois Sophie G. , Fox Clive J.
Published: May 2006

Data from the Continuous Plankton Recorder (CPR) survey over the past 40 years have shown that the abundance of copepods in many parts of the North Atlantic has declined, indicating geographical shifts in the plankton communities. Because the CPR does not sample all zooplankton species with equal efficiency, these observations may give a biased view of the overall changes. Here, we compensate for CPR undersampling by using previously published species-specific correction factors derived from comparisons of catches made with WP-2 ring-nets and the CPR. Based on such corrected data, the southern North Sea showed the highest concentrations of biomass, in contrast to maps based on uncorrected data, in which the areas of highest biomass were in the northern North Sea. Trend analysis confirmed the previously reported general decrease of total biomass. There has also been a general decrease in the mean size of zooplankton over time in the northern North Sea, but this has not been observed elsewhere. The results indicate the importance of smaller zooplankton species in the ecology of the Northwest European shelf. The changes in community structure may have general implications for energy transfer efficiency to higher trophic levels, and for the sustainability of fisheries resources.
Bidecadal variability in the intermediate waters of the northwestern subarctic Pacific and the Okhotsk Sea in relation to 18.6‐year period nodal tidal cycle
Authors: Osafune S. , Yasuda I.
Published: May 2006

On the basis of historical oceanographic data, we investigated the long‐term variations of the intermediate waters in the four regions in the northwestern subarctic Pacific: Oyashio, Okhotsk Sea Mode Water, Upstream Oyashio and East Kamchatka Current. We found bidecadal oscillations in these water properties that are synchronized with the 18.6‐year period nodal cycle. In periods when the diurnal tide is strong, the following characteristics are found: Apparent oxygen utilization and phosphate are low in Oyashio and Okhotsk Sea Mode Water. The thickness of the intermediate layers is large, and thus potential vorticity is correspondingly low, in Oyashio, Okhotsk Sea Mode Water, and Upstream Oyashio. Around the mesothermal (temperature maximum) water, isopycnal potential temperature are low in the areas on the Pacific side, and high in the intermediate layer of Okhotsk Sea Mode Water. The mixing ratio of Okhotsk Sea Mode Water in the Upstream Oyashio water is high. These bidecadal oscillations can be explained by changes in the vertical mixing around the Kuril Straits induced by the diurnal tide whose amplitude is modulated with the 18.6‐year nodal cycle. Higher sea surface salinity water around the Kuril Straits caused by stronger tidal mixing is possibly transported northward along the cyclonic Okhotsk Sea Gyre, and possibly enhances the formation of the dense shelf water. This makes apparent oxygen utilization, phosphate, and potential vorticity lower in Okhotsk Sea Mode Water and Oyashio.
Tropospheric water vapor from solar spectrometry and comparison with Jason microwave radiometer measurements
Authors: Somieski A. , Buerki B. , Geiger A. , Kahle H.‐G. , Pavlis E. C. , Becker‐Ross H. , Florek S. , Okruss M.
Published: May 2006

Atmospheric water vapor is a crucial factor in achieving highest accuracies in the field of space geodesy, particularly in the determination of height. A new instrumental approach to high‐precision determination of tropospheric water vapor has been investigated and realized in the construction of a mobile solar spectrometer. The optical approach as applied to the spectrometer allows the simultaneous measurement of single vibrational‐rotational absorption lines in the wide wavelength range between 728 nm and 915 nm. Dedicated field experiments have been carried out in the frame of an EU project for calibrating the Jason onboard microwave radiometer. A comparison of the spectrometer results with a conventional ground‐based water vapor radiometer and radiosondes revealed a fit on the order of 10 mm for the wet path delay, which corresponds to 1.6 kg/m2 integrated water vapor content (IWV). The comparison with the measurements from the radiometer of Jason reveals an even better agreement for the wet path delay. Long time series are foreseen for a detailed statistical analysis. The mobile solar spectrometer can be considered as a novel portable tool for determining tropospheric water vapor and as an excellent space‐borne radiometer calibration and validation system.
Some insight on why Bam (Iran) was destroyed by an earthquake of relatively moderate size
Authors: Bouchon Michel , Hatzfeld Denis , Jackson James A. , Haghshenas Ebrahim
Published: May 2006

The Bam (Iran) earthquake of 2003 resulted in one of the worst human disaster in recent years. Yet the magnitude of the event ‐ Mw = 6.6 ‐ was relatively moderate. We show that the remarkable recording of the ground motion produced in the city itself contains some clues which help explain this disaster. We identify three factors whose unfortunate combination led to the strong ground shaking which destroyed the city: 1) The Rayleigh‐like speed of the rupture, 2) The high slip velocity, which exceeded 2m/s over a large part of the fault, 3) The strong directivity, which focused the elastic energy released directly toward the city.
Developing a commercial production process for 500 000 targets per day: A key challenge for inertial fusion energy
Authors: Goodin D. T. , Alexander N. B. , Besenbruch G. E. , Bozek A. S. , Brown L. C. , Carlson L. C. , Flint G. W. , Goodman P. , Kilkenny J. D. , Maksaereekul W. , McQuillan B. W. , Nikroo A. , Paguio R. R. , Petzoldt R. W. , Raffray R. , Schroen D. G. , Sheliak J. D. , Spalding J. , Streit J. E. , Tillack M. S. , Vermillion B. A.
Published: May 2006

As is true for current-day commercial power plants, a reliable and economic fuel supply is essential for the viability of future Inertial Fusion Energy (IFE) [Energy From Inertial Fusion, edited by W. J. Hogan (International Atomic Energy Agency, Vienna, 1995)] power plants. While IFE power plants will utilize deuterium-tritium (DT) bred in-house as the fusion fuel, the “target” is the vehicle by which the fuel is delivered to the reaction chamber. Thus the cost of the target becomes a critical issue in regard to fuel cost. Typically six targets per second, or about 500 000∕day are required for a nominal 1000MW(e) power plant. The electricity value within a typical target is about $3, allocating 10% for fuel cost gives only 30 cents per target as-delivered to the chamber center. Complicating this economic goal, the target supply has many significant technical challenges—fabricating the precision fuel-containing capsule, filling it with DT, cooling it to cryogenic temperatures, layering the DT into a uniform layer, characterizing the finished product, accelerating it to high velocity for injection into the chamber, and tracking the target to steer the driver beams to meet it with micron-precision at the chamber center.
Long pulse high performance plasma scenario development for the National Spherical Torus Experiment
Authors: Kessel C. E. , Bell R. E. , Bell M. G. , Gates D. A. , Kaye S. M. , LeBlanc B. P. , Menard J. E. , Phillips C. K. , Synakowski E. J. , Taylor G. , Wilson R. ,   NSTX Research Team, Harvey R. W. , Mau T. K. , Ryan P. M. , Sabbagh S. A.
Published: May 2006

The National Spherical Torus Experiment [Ono et al., Nucl. Fusion, 44, 452 (2004)] is targeting long pulse high performance, noninductive sustained operations at low aspect ratio, and the demonstration of nonsolenoidal startup and current rampup. The modeling of these plasmas provides a framework for experimental planning and identifies the tools to access these regimes. Simulations based on neutral beam injection (NBI)-heated plasmas are made to understand the impact of various modifications and identify the requirements for (1) high elongation and triangularity, (2) density control to optimize the current drive, (3) plasma rotation and/or feedback stabilization to operate above the no-wall β limit, and (4) electron Bernstein waves (EBW) for off-axis heating/current drive (H/CD). Integrated scenarios are constructed to provide the transport evolution and H/CD source modeling, supported by rf and stability analyses. Important factors include the energy confinement, Zeff, early heating/H mode, broadening of the NBI-driven current profile, and maintaining q(0) and qmin>1.0. Simulations show that noninductive sustained plasmas can be reached at IP=800 kA, BT=0.5 T, κ≈2.5, βN⩽5, β⩽15%, fNI=92%, and q(0)>1.0 with NBI H/CD, density control, and similar global energy confinement to experiments. The noninductive sustained high β plasmas can be reached at IP=1.0 MA, BT=0.35 T, κ≈2.5, βN⩽9, β⩽43%, fNI=100%, and q(0)>1.5 with NBI H/CD and 3.0 MW of EBW H/CD, density control, and 25% higher global energy confinement than experiments. A scenario for nonsolenoidal plasma current rampup is developed using high harmonic fast wave H/CD in the early low IP and low Te phase, followed by NBI H/CD to continue the current ramp, reaching a maximum of 480 kA after 3.4 s.
High-energy Kα radiography using high-intensity, short-pulse lasers
Authors: Park H.-S. , Chambers D. M. , Chung H.-K. , Clarke R. J. , Eagleton R. , Giraldez E. , Goldsack T. , Heathcote R. , Izumi N. , Key M. H. , King J. A. , Koch J. A. , Landen O. L. , Nikroo A. , Patel P. K. , Price D. F. , Remington B. A. , Robey H. F. , Snavely R. A. , Steinman D. A. , Stephens R. B. , Stoeckl C. , Storm M. , Tabak M. , Theobald W. , Town R. P. J. , Wickersham J. E. , Zhang B. B.
Published: May 2006

The characteristics of 22–40keV Kα x-ray sources are measured. These high-energy sources are produced by 100TW and petawatt high-intensity lasers and will be used to develop and implement workable radiography solutions to probe high-Z and dense materials for the high-energy density experiments. The measurements show that the Kα source size from a simple foil target is larger than 60μm, too large for most radiography applications. The total Kα yield is independent of target thicknesses, verifying that refluxing plays a major role in photon generation. Smaller radiating volumes emit brighter Kα radiation. One-dimensional radiography experiments using small-edge-on foils resolved 10μm features with high contrast. Experiments were performed to test a variety of small volume two-dimensional point sources such as cones, wires, and embedded wires, measured photon yields, and compared the measurements with predictions from hybrid-particle-in-cell simulations. In addition to high-energy, high-resolution backlighters, future experiments will also need imaging detectors and diagnostic tools that are workable in the high-energy range. An initial look at some of these detector issues is also presented.