bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple reactive gasdynamic model for the computation of gas temperature and species concentrations behind reflected shock waves
Authors: Li H. , Owens Z. C. , Davidson D. F. , Hanson R. K.
Published: February 2008

A simple gasdynamic model, called CHEMSHOCK, has been developed to predict the temporal evolution of combustion gas temperature and species concentrations behind reflected shock waves with significant energy release. CHEMSHOCK provides a convenient simulation method to study various sized combustion mechanisms over a wide range of conditions. The model consists of two successive suboperations that are performed on a control mass during each infinitesimal time step: (1) first the gas mixture is allowed to combust at constant internal energy and volume; (2) then the gas is isentropically expanded (or compressed) at frozen composition to the measured pressure. The CHEMSHOCK model is first validated against results from a one‐dimensional reacting computational fluid dynamics (CFD) code for a representative case of heptane/O2/Ar mixture using a reduced mechanism. CHEMSHOCK is found to accurately reproduce the results of the CFD calculation with significantly reduced computational time. The CHEMSHOCK simulation results are then compared to experimental results, for gas temperature and water vapor concentration, obtained using a novel laser sensor based on fixed‐wavelength absorption of two H2O rovibrational transitions near 1.4 μm. Excellent agreement is found between CHEMSHOCK simulations and measurements in a progression of shock wave tests: (1) in H2O/Ar, with no energy release; (2) in H2/O2/Ar, with relatively small energy release; and (3) in heptane/O2/Ar, with large energy release. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 189–198, 2008
Integrability of maximal functions for generalized Lebesgue spaces with variable exponent
Authors: Mizuta Yoshihiro , Ohno Takao , Shimomura Tetsu
Published: February 2008

Our aim in this paper is to deal with integrability of maximal functions for generalized Lebesgue spaces with variable exponent. Our exponent approaches 1 on some part of the domain, and hence the integrability depends on the shape of that part and the speed of the exponent approaching 1. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hyers–Ulam–Rassias stability of a generalized Apollonius–Jensen type additive mapping and isomorphisms between C *‐algebras
Authors: Park Choonkil
Published: February 2008

Let X, Y be Banach modules over a C *‐algebra. We prove the Hyers–Ulam–Rassias stability of the following functional equation in Banach modules over a unital C *‐algebra:

equation image

It is shown that a mapping f: X → Y satisfies the above functional equation and f (0) = 0 if and only if the mapping f: X → Y is Cauchy additive. As an application, we show that every almost linear bijection h: A → B of a unital C *‐algebra A onto a unital C *‐algebra B is a C *‐algebra isomorphism when h (2d uy) = h (2d u) h (y) for all unitaries u ∈ A, all y ∈ A, and all d ∈ Z. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lagrangian meshfree particles method (SPH) for large deformation and failure flows of geomaterial using elastic–plastic soil constitutive model
Authors: Bui Ha H. , Fukagawa Ryoichi , Sako Kazunari , Ohno Shintaro
Published: February 2008

Simulation of large deformation and post‐failure of geomaterial in the framework of smoothed particle hydrodynamics (SPH) are presented in this study. The Drucker–Prager model with associated and non‐associated plastic flow rules is implemented into the SPH code to describe elastic–plastic soil behavior. In contrast to previous work on SPH for solids, where the hydrostatic pressure is often estimated from density by an equation of state, this study proposes to calculate the hydrostatic pressure of soil directly from constitutive models. Results obtained in this paper show that the original SPH method, which has been successfully applied to a vast range of problems, is unable to directly solve elastic–plastic flows of soil because of the so‐called SPH tensile instability. This numerical instability may result in unrealistic fracture and particles clustering in SPH simulation. For non‐cohesive soil, the instability is not serious and can be completely removed by using a tension cracking treatment from soil constitutive model and thereby give realistic soil behavior. However, the serious tensile instability that is found in SPH application for cohesive soil requires a special treatment to overcome this problem. In this paper, an artificial stress method is applied to remove the SPH numerical instability in cohesive soil. A number of numerical tests are carried out to check the capability of SPH in the current application. Numerical results are then compared with experimental and finite element method solutions. The good agreement obtained from these comparisons suggests that SPH can be extended to general geotechnical problems. Copyright © 2008 John Wiley & Sons, Ltd.
Multigrid solution of the optical flow system using a combined diffusion‐ and curvature‐based regularizer
Authors: Köstler H. , Ruhnau K. , Wienands R.
Published: February 2008

Optical flow techniques are used to compute an approximate motion field in an image sequence. We apply a variational approach for the optical flow using a simple data term but introducing a combined diffusion‐ and curvature‐based regularizer. The same data term arises in image registration problems where a deformation field between two images is computed. For optical flow problems, usually a diffusion‐based regularizer should dominate, whereas for image registration a curvature‐based regularizer is more appropriate. The combined regularizer enables us to handle optical flow and image registration problems with the same solver and it improves the results of each of the two regularizers used on their own. We develop a geometric multigrid method for the solution of the resulting fourth‐order systems of partial differential equations associated with the variational approach for optical flow and image registration problems. The adequacy of using (collective) pointwise smoothers within the multigrid algorithm is demonstrated with the help of local Fourier analysis. Galerkin‐based coarse grid operators are applied for an efficient treatment of jumping coefficients. We show some multigrid convergence rates, timings and investigate the visual quality of the approximated motion or deformation field for synthetic and real‐world images. Copyright © 2008 John Wiley & Sons, Ltd.
Algebraic multigrid for k‐form Laplacians
Authors: Bell Nathan , Olson Luke N.
Published: February 2008

In this paper we describe an aggregation‐based algebraic multigrid method for the solution of discrete k‐form Laplacians. Our work generalizes Reitzinger and Schöberl's algorithm to higher‐dimensional discrete forms. We provide conditions on the tentative prolongators under which the commutativity of the coarse and fine de Rham complexes is maintained. Further, a practical algorithm that satisfies these conditions is outlined, and smoothed prolongation operators and the associated finite element spaces are highlighted. Numerical evidence of the efficiency and generality of the proposed method is presented in the context of discrete Hodge decompositions. Copyright © 2008 John Wiley & Sons, Ltd.
The Memorial Sloan Kettering Cancer Center experience with outpatient administration of high dose methotrexate with leucovorin rescue
Authors: Zelcer Shayna , Kellick Michael , Wexler Leonard H. , Gorlick Richard , Meyers Paul A.
Published: February 2008

Background

We describe the safety and feasibility of an outpatient high dose methotrexate (HDMTX) regimen.

Methods

HDMTX (12 g/m2) is administered in a pediatric day hospital (PDH) intravenously (IV) over 4 hrs. Urinary alkalinization is achieved using an IV bolus of sodium bicarbonate and oral bicarbonate tablets. Daily visits to the PDH follow. Leucovorin is begun 24 hrs. after MTX at a standard dose of 10 mg orally (po) every 6 hrs. (q6h). The leucovorin dose is escalated between a range of 20 mg po q6h to 1 g as a continuous IV drip over 24 hrs. according to an institutional algorithm for levels above 10, 1, and 0.1 µmol/L at 24, 48, and 72 hrs. post‐MTX. To evaluate our approach, we conducted a retrospective review of all HDMTX courses administered at the Memorial Sloan Kettering Cancer Center between 1996 and 2002.

Results

Out of a total of 708 MTX courses, 82% were successfully completed as an outpatient. Forty‐nine percent of the MTX courses were treated with standard dose leucovorin while 49% required a dose escalation, the majority of which was to 20–30 mg po q6h. Observed toxicity included mild (Grade 0–I) nephrotoxicity and reversible transaminitis in the majority of patients. Myelosuppression was manifested mainly as neutropenia, with Grade III–IV toxicity in 16% of patients.

Conclusions

Outpatient administration of HDMTX and the required supportive therapy is safe and feasible using the described approach. Approximately half of the patients will require leucovorin dose modification based on serial monitoring of MTX levels. Pediatr Blood Cancer 2008;50:1176–1180. © 2008 Wiley‐Liss, Inc.
Allogeneic stem cell transplantation in a patient with relapsed Ewing sarcoma
Authors: Lucas Kenneth G. , Schwartz Cindy , Kaplan Joel
Published: February 2008

Ewing sarcoma (ES) can express tumor antigens which can be recognized by T cells, making allogeneic stem cell transplant (SCT) a potential option for those patients with refractory disease. A 6‐year old with multifocal ES developed a recurrence of pulmonary metastases and underwent an allogeneic bone marrow transplant from her human leukocyte antigen (HLA) 10/10 matched mother. During a taper of her immunosuppression, she developed grade 1 skin and oral graft versus host disease (GVHD). CT scans performed 9 months post‐transplant revealed a marked decrease in the size of her pulmonary lesions compared to scans 2 months post‐transplant. This case highlights the possibility of treating patients with refractory metastatic ES with allogeneic SCT. Pediatr Blood Cancer 2008;51:142–144. © 2008 Wiley‐Liss, Inc.
Validating the effects of drug treatment on blood pressure in the General Practice Research Database
Authors: Delaney Joseph A. C. , Moodie Erica E. M. , Suissa Samy
Published: February 2008

Purpose

Observational studies using clinical databases, such as the United Kingdom's General Practice Research Database (GPRD), may provide an alternative to clinical trial data for detecting longitudinal changes in blood pressure due to drug exposures that vary over time. Blood pressure data which are measured at variable intervals and are often missing present a particular methodological challenge to the analysis of such studies.

Methods

To assess effects on blood pressure, we extracted from the GPRD several cohorts of new drug users of warfarin (n = 21 532), ibuprofen (n = 92 037), proton pump inhibitors (n = 153 695), statins (n = 118 704), rofecoxib (n = 6399), and celecoxib (n = 6217) from 2001 to 2003. Several blood pressure readings were missing either before or after initiating therapy. We compared the results of analyses using a linear mixed model with a pre–post quasi‐experimental design, using the multiple imputation approach to account for missing data.

Results

There was evidence that the missing blood pressure data were not missing completely at random as subjects with more blood pressure readings tended to have higher recorded values. For statins, the mixed model estimated a change in systolic blood pressure of −3.80 mmHg (99% confidence interval (CI): from −3.97 to −3.63), similar to the quasi‐ experimental model and to the −4.00 mmHg estimated from clinical trials. Sensitivity analyses indicate that these estimates are robust. For rofecoxib, the change in systolic blood pressure were 2.20 mmHg (99%CI: 1.09–3.32) and 1.21 mmHg (99%CI: 0.21–2.22) for the two methods, respectively, again confirming the findings of randomized trials.

Conclusion

With appropriate statistical techniques, GPRD blood pressure data can be used to estimate blood pressure changes secondary to drug therapy. Copyright © 2008 John Wiley & Sons, Ltd.
A facile route of polythiophene nanoparticles via Fe3+‐catalyzed oxidative polymerization in aqueous medium
Authors: Lee Sun Jong , Lee Jung Min , Cheong In Woo , Lee Hoosung , Kim Jung Hyun
Published: February 2008

We have demonstrated that unsubstituted thiophene can be polymerized by Fe3+‐catalyzed oxidative polymerization inside nanosized thiophene monomer droplets, that is, nanoreactors, dispersed in aqueous medium, which can be performed under acidic solution conditions with anionic surfactant. Besides, we proposed a synthetic mechanism for the formation of the unsubstituted polythiophene nanoparticles in aqueous medium. This facile method includes a FeCl3/H2O2 (catalyst/oxidant) combination system, which guarantees a high conversion (ca. 99%) of thiophene monomers with only a trace of FeCl3. The average particle size was about 30 nm, within a narrow particle‐size distribution (PDI = 1.15), which resulted in a good dispersion state of the unsubstituted polythiophene nanoparticles. Hansen solubility parameters were introduced to interpret the dispersion state of the polythiophene nanoparticles with various organic solvents. The UV–Visible absorption and photoluminescence (PL) spectrum were measured to investigate the light emitting properties of the prepared unsubstituted polythiophene nanoparticle emulsions. According to non‐normalized PL analysis, the reduced total PL intensity of the polythiophene nanoparticle emulsions can be rationalized by self‐absorption in a wavelength range less than 500 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2097–2107, 2008
Synthesis of amphiphilic poly(methyl methacrylate‐ b‐ethylene oxide) copolymers from monohydroxy telechelic poly(methyl methacrylate) as macroinitiator
Authors: Dhara Mahua G. , Baskaran Durairaj , Sivaram Swaminathan
Published: February 2008

The synthesis of well‐defined poly(methyl methacrylate)‐block‐poly(ethylene oxide) (PMMA‐b‐PEO) dibock copolymer through anionic polymerization using monohydroxy telechelic PMMA as macroinitiator is described. Living anionic polymerization of methyl methacrylate was performed using initiators derived from the adduct of diphenylethylene and a suitable alkyllithium, either of which contains a hydroxyl group protected with tert‐butyldimethylsilyl moiety in tetrahydrofuran (THF) at −78 °C in the presence of LiClO4. The synthesized telechelic PMMAs had good control of molecular weight with narrow molecular weight distribution (MWD). The 1H NMR and MALDI‐TOF MS analysis confirmed quantitative functionalization of chain‐ends. Block copolymerization of ethylene oxide was carried out using the terminal hydroxyl group of PMMA as initiator in the presence of potassium counter ion in THF at 35 °C. The PMMA‐b‐PEO diblock copolymers had moderate control of molecular weight with narrow MWD. The 1H NMR results confirm the absence of trans‐esterification reaction of propagating PEO anions onto the ester pendants of PMMA. The micellation behavior of PMMA‐b‐PEO diblock copolymer was examined in water using 1H NMR and dynamic light scattering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2132–2144, 2008
Poly(butylene terephthalate)/clay nanocomposite compatibilized with poly(ethylene‐co‐glycidyl methacrylate). II. Nonisothermal crystallization
Authors: Huang Jiann‐Wen
Published: February 2008

Melting behaviors and nonisothermal crystallization of poly(butylene terephthalate)/poly(ethylene‐co‐glycidyl methacrylate) (PBT/PEGMA), PBT/commercial modified montmorillonite clays (PBT/Clay), and PBT/exfoliated silicates (PBT/PEGMA/Clay) nanocomposites were studied by wide‐angle X‐ray diffraction and differential scanning calorimeter. PEGMA is used as a compatibilizer. For both isothermally and nonisothermally crystallized samples, PEGMA facilitates the recrystallization of PBT during the heating scans, and leads to a less degree of perfection of the crystals. However, the clay hinders the recrystallization growth during heating scans, and increases perfection of the crystals. Nonisothermal crystallization kinetics was described by kinetic models and undercooling was taken into account. The PEGMA would lead to an increase of the blend viscosity, rendering the chains less mobile and lower the crystallizability of PBT in PBT/PEGMA. The well‐dispersed exfoliated silicates in PBT/PEGMA/Clay cause a large number of nuclei to precede crystallization. The fold surface free energy (σe) and activation energy also supported the interpretation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 564–576, 2008
Influence of aggregation on the phosphorescence of iridium complex in poly(methyl methacrylate) matrix
Authors: Mao Chih‐Hsin , Hong Jin‐Long , Yeh An‐Chi
Published: February 2008

In this study, novel phosphorescent compound of iridium(III)bis(2,3‐diphenylquinoxaline)2‐(benzoimidazol‐2‐yl)pyridine (IrQB) was prepared and the emission study suggests the solid form of IrQB has less phosphorescence intensity than its solution in tetrahydrofuran (THF). To avoid the potential aggregation of IrQB in the concentrated state, poly(methyl methacrylate) (PMMA) was intentionally added as isolator to make solutions of different concentrations in THF and then solid films of IrQB/PMMA of different compositions after THF removal. Films of IrQB/PMMA prepared from dilute solutions exhibit two emission bands centered at 540 and 640 nm, respectively, which is in contrast to the sole 640‐nm emission band observed for films prepared from semidilute solutions. The 540‐ and 640‐nm bands show progressive variations of the intensity with temperature. Emission band at 540 nm is derived from the polarized optical microscope and is attributed to the IrQB aggregates, whose life‐time indicates it is phosphorescent in nature. This aggregate formation is strongly affected by the applied concentrations of IrQB and PMMA in the preparative solution state. Model to postulate the mechanism of aggregate formation in the solution and the derived film states is thereby presented in this study. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 631–639, 2008
Crystallization of Insensitive HMX
Authors: Kröber Hartmut , Teipel Ulrich
Published: February 2008

In this study HMX was recrystallized from different solvents by a cooling crystallization process to improve the product quality and to produce a more insensitive product. It was found that particles with the best quality were crystallized from propylenecarbonate with a nucleation initiation by dosing a small amount of water as drowning‐out substance. This leads to particles with a very high density (near to the theoretical value) and thus to particles with a small amount of inclusions. GAP tests with this product show less sensitivity against shock. A clear linear dependence of the particle density on the shock initiation pressure was found. The particle density is relatively easy to measure so it will be a useful measure to determine the sensitivity of the material.
Metallized SWCNT–Promising Way to Low Sensitive High Energetic Nanocomposites
Authors: Assovskiy Igor G.
Published: February 2008

The single‐walled carbon nanotube (SWCNT) is proposed as the best protective coating for energetic metal nanoparticles. An advanced laser‐based technology has been applied to synthesize SWCNT filled or covered by metal. This laser synthesis of metallized SWCNT operates under the normal conditions that could be a basis for a high‐productive technology of continuous synthesis of metalllized SWCNT.
Statistical Assessment Methods for the Sensitivity of Energetic Materials
Authors: Alouaamari Mohamed , Lefebvre Michel H. , Perneel Christiaan , Herrmann Michael
Published: February 2008

The joint research projectParticle Processing and Characterizationwas started in March 2003 under the EUROPA ERG1 Arrangement, with the objective to study the influence of crystallization and processing techniques on particle quality and its implication for the formulation of PBX with IM behavior. As sensitivity assessment is a crucial task of the project, impact sensitivity tests of HMX and RDX samples have been performed at two different laboratories, and several statistical techniques have been tested in addition to the standard BAM “1/6” and Bruceton “up and down” methods.
Selection and Synthesis of Energetic Heterocyclic Compounds Suitable for Use in Insensitive Explosive and Propellant Compositions
Authors: Millar Ross W. , Hamid Javid , Endsor Robert , Swinton Peter F. , Cooper John
Published: February 2008

The rationale behind developing insensitive energetic compounds (IECs) for incorporation into insensitive munition (IM) formulations (rather than the alternative approach of desensitizing higher energy but sensitive compounds) is discussed. With the aim of selecting a maximum of 2–3 IECs suitable for use in insensitive explosive and propellant compositions, a survey of the literature on IECs published in the last 20 years was carried out. From around 50 candidates, a selection was made of eight prime candidates, all heterocyclic compounds (principally monocyclic or fused‐ring bicyclic compounds of the di‐ or triazine, triazole or oxadiazole classes), which displayed explosive performance significantly better than that of the ubiquitous IEC, TATB. The criteria for inclusion of compounds in these listings are described. Screening of the eight candidate compounds against further performance criteria reduced the list to five compounds which were evaluated in detail – these were: CL‐14 (5,7‐diamino‐4,6‐dinitrobenzofuroxan), ANPZ‐i (2,5‐diamino‐3,6‐dinitropyrazine), NNHT (2‐nitrimino‐5‐nitro‐hexahydro‐1,3,5‐triazine), NTAPDO (5‐nitro‐2,4,6‐triaminopyrimidine‐1,3‐dioxide), and PANT [4‐(picrylamino)‐5‐nitro‐1,2,3‐triazole]. A detailed analysis of scale‐up issues associated with each compound was then made, including cost and availability of precursors, hazards (chemical and explosive), effluent streams, and other scale‐up issues (e.g. materials of plant construction). A further downselection using these criteria gave the present short‐list comprising three compounds (the first three listed above) and further evaluation is in progress. The results of this study, funded by UK MOD, comprise the UK contribution to a nine‐nation European research collaboration in the EUCLID Common European Priority Area 14 “Energetic Materials”, as part of a five‐year project which commenced in October 2003.
Current treatment options for head lice and scabies
Authors: Connolly Maureen
Published: February 2008

Local resistance patterns and patient/parent preferences should be taken into account when prescribing for head lice and scabies. This Drug Review considers the current management options, followed by a review of prescription data, sources of further information and the Datafile. Copyright © 2008 Wiley Interface Ltd
Versatis: medicated lidocaine plaster for postherpetic neuralgia
Authors: Chaplin Steve , Gallagher Jayne
Published: February 2008

Versatis, a topical lidocaine plaster, provides pain relief for postherpetic neuralgia. In our review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Dr Jayne Gallagher comments on its role in therapy. Copyright © 2008 Wiley Interface Ltd
Diagnosis and management of psychosis in older people
Authors: Karim Salman
Published: February 2008

Our series Prescribing in older people gives practical advice for successful management of the special problems experienced by this patient group. Here, the author describes the diagnosis and management of psychotic illness. Copyright © 2008 Wiley Interface Ltd
How to change practice — a NICE guide to overcoming the barriers
Authors: Chaplin Steve
Published: February 2008

Steve Chaplin reviews a new guide from NICE that gives practical advice on how to understand, identify and overcome barriers to changing practice in line with latest guidance. Copyright © 2008 Wiley Interface Ltd
Robotic pyeloplasty using internet protocol and satellite network‐based telesurgery
Authors: Nguan C. Y. , Morady R. , Wang C. , Harrison D. , Browning D. , Rayman R. , Luke P. P. W.
Published: February 2008

Background

In North America, the urological community has embraced surgical robotic technology in the performance of complex laparoscopic surgery. The performance of complex long‐distance telesurgery requires further investigation prior to clinical application.

Methods

The feasibility of laparoscopic robot‐assisted pyeloplasty in a porcine model was assessed using the Zeus robot and the internet protocol virtual private network (IP‐VPNe) and satellite links. Eighteen pyeloplasty procedures were performed, using real‐time, IP‐VPNe and satellite network connection (six of each). Network and objective operative data were collected.

Results

Despite network delays and jitter, it was feasible to perform the pyeloplasty procedure without significant detriment in operative time or surgical results compared with real‐time surgery.

Conclusion

The completion of complex tasks such as robotic pyeloplasty is feasible using both land‐line and satellite telesurgery. However, the clinical relevance of telesurgery requires further assessment. Copyright © 2008 John Wiley & Sons, Ltd.
Occult hepatitis B virus and hepatitis C virus infections
Authors: Carreño* Vicente , Bartolomé Javier , Castillo Inmaculada , Quiroga Juan Antonio
Published: February 2008

Occult HBV infection is a well‐recognised clinical entity characterised by the detection of HBV‐DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV‐RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV‐RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody‐(anti‐HCV) negative and serum HCV‐RNA‐negative patients with abnormal liver function tests and in anti‐HCV‐positive patients who have no detectable serum HCV‐RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation. Copyright © 2008 John Wiley & Sons, Ltd.
The Biplot as a diagnostic tool of local dependence in latent class models. A medical application
Authors: Sepúlveda R. , Vicente‐Villardón J. L. , Galindo M. P.
Published: February 2008

Latent class models (LCMs) can be used to assess diagnostic test performance when no reference test (a gold standard) is available, considering two latent classes representing disease or non‐disease status. One of the basic assumptions in such models is that of local or conditional independence: all indicator variables (tests) are statistically independent within each latent class. However, in practice this assumption is often violated; hence, the two‐LCM fits the data poorly. In this paper, we propose the use of Biplot methods to identify the conditional dependence between pairs of manifest variables within each latent class. Additionally, we propose incorporating such dependence in the corresponding latent class using the log‐linear formulation of the model. Copyright © 2008 John Wiley & Sons, Ltd.
Concept location in formal specifications
Authors: Bollin Andreas
Published: February 2008

When kept up‐to‐date, formal specifications can act as valid artifacts for maintenance tasks. However, their linguistic density and size impede comprehension, reuse, and change activities. Techniques such as specification slicing and chunking help in reducing the number of relevant lines of text to be considered, but they expect the point of change to be known a priori. This contribution presents a process model for concept location within formal Z‐specifications. It also considers those situations when the location is not even roughly known. The identification is comparable to the identification of regions with high cohesion. The approach is based on the idea of first transforming the specification to an augmented graph and, secondly, on the generation of spacial clusters. Copyright © 2008 John Wiley & Sons, Ltd.
Towards scalable virtuality in C++
Authors: Nicart Florent
Published: February 2008

This article describes a programming technique that allows a size reduction of C++ objects by designing classes in a particular way. In order to reduce the size of the objects to the extreme, a technique to simulate runtime polymorphism and avoid the addition of the implicit virtual pointer is presented. Copyright © 2008 John Wiley & Sons, Ltd.
Evidence‐Based Surgical Management of Substernal Goiter
Authors: White Matthew L. , Doherty Gerard M. , Gauger Paul G.
Published: February 2008

Background

A number of reports have been published concerning the surgical treatment of substernal goiters; however, there is yet to be a comprehensive review of this body of literature using evidence‐based methodology.

Methods

This article is a systematic review of the literature using evidence‐based criteria and a review of unpublished data from our institution.

Results

Issue 1. Limited level III/IV data suggest that the incidence of cancer in substernal goiters is not higher than the incidence of cancer in cervical goiters. Risk factors for malignancy in substernal goiters may include a family history of thyroid pathology, a history of cervical radiation therapy, recurrent goiter, and the presence of cervical adenopathy (grade C recommendation). Issue 2. Prospective level V data suggest that, for most patients, expert endocrine surgeons utilize an extracervical approach approximately 2% of the time to remove a substernal goiter safely; a sternotomy or thoracotomy appears more likely in cases of a primary substernal goiter or a mass larger than the thoracic inlet (no recommendation). Issue 3. There may be a higher rate of permanent hypoparathyroidism and unintentional permanent recurrent laryngeal nerve injury when total thyroidectomy is performed for removal of a substernal goiter than for removal of a cervical goiter alone (grade C recommendation). Injury of the external branch of the superior laryngeal nerve was not specifically addressed and is almost certainly underreported. Issue 4. The presence of a substernal goiter, especially being present more than 5 years and causing significant tracheal compression, is likely a risk factor for tracheomalacia and tracheostomy (grade C recommendation). Tracheomalacia with substernal goiter is an infrequent occurrence, and many cases of tracheomalacia can be managed without tracheostomy (no recommendation). Issue 5. Prospective level V data suggest that about 5% to 10% of operations for substernal goiters are performed because of recurrent or persistent disease, although retrospective level V data report an even higher rate, up to 37%. The most common initial operations with recurrence or persistence appear to be subtotal or hemithyroidectomy (no recommendation).

Conclusion

Evidence‐based recommendations provide reliable information regarding the pathologic findings and operative management of substernal goiters in expert hands.
Acyl Migration Kinetics of Vegetable Oil 1,2‐Diacylglycerols
Authors: Laszlo Joseph A. , Compton David L. , Vermillion Karl E.
Published: February 2008

The acyl migration kinetics of long‐chain 1,2‐diacylglycerol (1,2‐DAG) to form 1,3‐diacylglycerol (1,3‐DAG) over the temperature range of 25–80 °C were examined using 1H‐NMR spectroscopy. Lipase‐catalyzed ethanolysis of high‐oleic sunflower oil, followed by a series of solvent extraction steps, generated high purity 1,2‐DAG (0.93 mol fraction of the DAG content). The 1,2‐DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature, indicating that long‐chain acyl group migration is neither endothermic nor exothermic. Determination of the temperature‐dependent, first‐order reaction kinetic parameters revealed a 1,2‐DAG half life (t1/2) of 3,425 h and 15.8 h at 25 and 80 °C, respectively. A comparison of 1,2‐DAG with 2‐monoacylglycerol indicated that there is no difference between the two in the potential energy state (ΔG‡) of their respective transitions states or cyclic intermediates.
Resolution of renal adenocarcinoma-induced secondary inappropriate polycythaemia after nephrectomy in two cats
Authors: Klainbart Sigal , Segev Gilad , Loeb Emmanuel , Melamed Dana , Aroch Itamar
Published: February 2008

Two cases of secondary, inappropriate polycythaemia caused by renal adenocarcinoma in domestic shorthair cats, are described. The cats were 9 and 12 years old and both were presented because of generalised seizures presumably due to hyperviscosity. Both cats had a markedly increased haematocrit (0.770 and 0.632 l/l) and thrombocytosis (744×109/l and 926×109/l). An abdominal ultrasound revealed a mass in the cranial pole of one kidney in both cats. Serum erythropoietin (EPO) concentration was within the reference interval (RI) in both cats but was inappropriately high considering the markedly increased haematocrit. The cats were initially stabilised and managed by multiple phlebotomies and intravenous fluid therapy and underwent nephrectomy of the affected kidney later on. Both the polycythaemia and thrombocytosis resolved following surgery. Postoperative serum EPO concentration, measured in one cat, decreased markedly. Histopathology of the affected kidneys confirmed a diagnosis of renal adenocarcinoma. Both cats were stable for an 8-month follow-up period; however, one cat had developed a stable chronic kidney disease (CKD), while the other was represented 8 months postoperatively due to dyspnoea, and had radiographic evidence of lung metastasis, presumably because of the spread of the original renal tumour and was euthanased. Initial stabilisation of polycythaemic cats should include multiple phlebotomies. Nephrectomy should be considered in cats with secondary, inappropriate, renal adenocarcinoma-related polycythaemia when only one kidney is affected by the tumour, and provided that the other kidney's function is satisfactory. Nephrectomy should be expected to resolve the polycythaemia and lead to normalisation of serum EPO concentration.
A Scenario on the Stepwise Evolution of the Genetic Code
Authors: Xiao Jing-Fa , Yu Jun
Published: February 2008

It is believed that in the RNA world the operational (ribozymes) and the informational (riboscripts) RNA molecules were created with only three (adenosine, uridine, and guanosine) and two (adenosine and uridine) nucleosides, respectively, so that the genetic code started uncomplicated. Ribozymes subsequently evolved to be able to cut and paste themselves and riboscripts were acceptive to rigorous editing (adenosine to inosine); the intensive diversification of RNA molecules shaped novel cellular machineries that are capable of polymerizing amino acids—a new type of cellular building materials for life. Initially, the genetic code, encoding seven amino acids, was created only to distinguish purine and pyrimidine; it was later expanded in a stepwise way to encode 12, 15, and 20 amino acids through the relief of guanine from its roles as operational signals and through the recruitment of cytosine. Therefore, the maturation of the genetic code also coincided with (1) the departure of aminoacyl-tRNA synthetases (AARSs) from the primordial translation machinery, (2) the replacement of informational RNA by DNA, and (3) the co-evolution of AARSs and their cognate tRNAs. This model predicts gradual replacements of RNA-made molecular mechanisms, cellular processes by proteins, and informational exploitation by DNA.
A Modified T-Test Feature Selection Method and Its Application on the HapMap Genotype Data
Authors: Zhou Nina , Wang Lipo
Published: February 2008

Single nucleotide polymorphisms (SNPs) are genetic variations that determine the differences between any two unrelated individuals. Various population groups can be distinguished from each other using SNPs. For instance, the HapMap dataset has four population groups with about ten million SNPs. For more insights on human evolution, ethnic variation, and population assignment, we propose to find out which SNPs are significant in determining the population groups and then to classify different populations using these relevant SNPs as input features. In this study, we developed a modified t-test ranking measure and applied it to the HapMap genotype data. Firstly, we rank all SNPs in comparison with other feature importance measures including F-statistics and the informativeness for assignment. Secondly, we select different numbers of the most highly ranked SNPs as the input to a classifier, such as the support vector machine, so as to find the best feature subset corresponding to the best classification accuracy. Experimental results showed that the proposed method is very effective in finding SNPs that are significant in determining the population groups, with reduced computational burden and better classification accuracy.
Oxypred: Prediction and Classification of Oxygen-Binding Proteins
Authors: Muthukrishnan S. , Garg Aarti , Raghava G.P.S.
Published: February 2008

This study describes a method for predicting and classifying oxygen-binding proteins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding proteins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Secondly, an SVM module was developed based on amino acid composition, classifying the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemocyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins (available from http://www.imtech.res.in/raghava/oxypred/).
Automated SNP Genotype Clustering Algorithm to Improve Data Completeness in High-Throughput SNP Genotyping Datasets from Custom Arrays
Authors: Smith Edward M. , Littrell Jack , Olivier Michael
Published: February 2008

High-throughput SNP genotyping platforms use automated genotype calling algorithms to assign genotypes. While these algorithms work efficiently for individual platforms, they are not compatible with other platforms, and have individual biases that result in missed genotype calls. Here we present data on the use of a second complementary SNP genotype clustering algorithm. The algorithm was originally designed for individual fluorescent SNP genotyping assays, and has been optimized to permit the clustering of large datasets generated from custom-designed Affymetrix SNP panels. In an analysis of data from a 3 K array genotyped on 1,560 samples, the additional analysis increased the overall number of genotypes by over 45,000, significantly improving the completeness of the experimental data. This analysis suggests that the use of multiple genotype calling algorithms may be advisable in high-throughput SNP genotyping experiments. The software is written in Perl and is available from the corresponding author.
A new description of equivariant cohomology for totally disconnected groups
Authors: Voigt Christian
Published: February 2008

We consider smooth actions of totally disconnected groups on simplicial complexes and compare different equivariant cohomology groups associated to such actions. Our main result is that the bivariant equivariant cohomology theory introduced by Baum and Schneider can be described using equivariant periodic cyclic homology. This provides a new approach to the construction of Baum and Schneider as well as a computation of equivariant periodic cyclic homology for a natural class of examples. In addition we discuss the relation between cosheaf homology and equivariant Bredon homology. Since the theory of Baum and Schneider generalizes cosheaf homology we finally see that all these approaches to equivariant cohomology for totally disconnected groups are closely related.
The Guillemin–Sternberg conjecture for noncompact groups and spaces
Authors: Hochs P. , Landsman N.P.
Published: February 2008

The Guillemin–Sternberg conjecture states that “quantisation commutes with reduction” in a specific technical setting. So far, this conjecture has almost exclusively been stated and proved forcompactLie groupsGacting oncompactsymplectic manifolds, and, largely due to the use of SpincDirac operator techniques, has reached a high degree of perfection under these compactness assumptions. In this paper we formulate an appropriate Guillemin–Sternberg conjecture in the general case, under the main assumptions that the Lie group action is proper and cocompact. This formulation is motivated by our interpretation of the “quantisation commuates with reduction” phenomenon as a special case of the functoriality of quantisation, and uses equivariantK-homology and theK-theory of the groupC*-algebraC*(G) in a crucial way. For example, the equivariant index – which in the compact case takes values in the representation ringR(G) – is replaced by the analytic assembly map – which takes values inK0(C*(G)) – familiar from the Baum–Connes conjecture in noncommutative geometry. Under the usual freeness assumption on the action, we prove our conjecture for all Lie groupsGhaving a discrete normal subgroup Γ with compact quotientG/Γ, but we believe it is valid for all unimodular Lie groups.
Hyaluronic acid ester in myringoplasty
Authors: Prior M , Gibbins N , John G , Rhys-Williams S , Scott P
Published: February 2008

Objectives:

To investigate the use of a new technique to close persistent tympanic membrane perforations under general anaesthesia, in patients in whom this has previously been considered impractical.

Design:

Twenty patients aged 50 years and over were recruited. All had a persistent, symptomatic tympanic membrane perforation in at least one ear. Pre-operatively, an audiogram was performed and the tympanic membrane was assessed in order to establish the site and size of the perforation. Under general anaesthesia, the edges of the perforation were freshened and a sheet of Epifilm, trimmed to a size roughly 2 mm larger in diameter than the perforation, was tucked through the perforation. The ear was dressed appropriately. Patients were seen two weeks post-operatively in the out-patients department and reassessed.

Setting:

The study was based at Poole General Hospital, a District General Hospital.

Participants:

Twenty patients were recruited from the out-patients clinics of Poole Hospital ENT department.

Main outcome measures:

(1) closure of the perforation, as a percentage of the original size; (2) improvement of hearing, as an average across all frequencies, expressed in dB hearing level; and (3) presence or absence of discharge.

Results:

Five patients were operated upon and assessed six weeks post-operatively. The Epifilm had dissolved but the perforations remained the same size in all five patients. There were no other adverse effects. Pure tone audiometry at this stage was redundant. The study was subsequently aborted.

Conclusions:

The authors conclude that repair of tympanic membrane perforations with hyaluronic acid ester films is not to be recommended.
Post-tonsillectomy dysgeusia with weight loss: possible involvement of soft palate
Authors: Scinska A , Jodkowska A , Korkosz A , Kukwa W , Sienkiewicz-Jarosz H
Published: February 2008

Objective:

To demonstrate the importance of detailed, multidisciplinary examination of patients with post-tonsillectomy taste distortions, and to show that post-tonsillectomy dysgeusia may originate in the caudal part of the soft palate.

Case report:

We describe a 29-year-old man who suffered from severe post-tonsillectomy dysgeusia and phantogeusia with secondary weight loss and depression-like symptomatology. The patient had normal electrogustometric thresholds and sensitivity to touch on the posterior tongue. In contrast, elevated taste threshold and reduced sensitivity to touch was found on the caudal part of the soft palate (the palatoglossal arches). More marked elevation of electrogustometric threshold and insensitivity to touch on the right palatoglossal arch correlated with post-operative haemorrhage from the right tonsillar fossa. Psychiatric examination excluded major depression, eating disorders and drug abuse.

Conclusions:

Dysgeusia constitutes a rare but significant complication of tonsillectomy. Damage to the lingual branch of the glossopharyngeal nerve innervating the posterior tongue is thought to be a major cause of this complication. However, damage to the tonsillar branches of the glossopharyngeal nerve and the soft palate should also be considered as a cause of post-tonsillectomy dysgeusia. Further studies are needed to assess whether post-operative haemorrhage could indicate heightened risk of dysgeusia.
Activation of middle-ear muscles by transcranial magnetic stimulation
Authors: Fiorino F G , Bertolasi L , Barbieri F
Published: February 2008

Objectives:

To evaluate the reliability of transcranial magnetic stimulation in eliciting admittance changes due to activation of middle-ear muscles.

Methods:

Admittance changes induced by transcranial magnetic stimulation at the inion were evaluated in eight normal subjects, two subjects with prelingual deafness and 22 patients suffering from other otological disorders characterised by absence of acoustic reflex.

Results:

Responses showed a predominant negative peak in normal ears. Two small positive components, one preceding and the other following the negative deflection, were less consistently elicited. Only a positive wave was detected in otosclerotic subjects. Patients with tympanic membrane perforation or previous tympanoplasty with ossicular discontinuity did not show any response.

Conclusions:

Transcranial magnetic stimulation is able to activate both stapedius and tensor tympani muscles. In conjunction with admittance audiometry, it may represent a method of exploring the mechanics of the middle ear when acoustic reflex testing is not reliable. It can be helpful in the confirmation of stapes fixation when a severe to profound hearing loss is present.
Foregut duplication cyst of the pharynx
Authors: Fraser L , Howatson A G , MacGregor F B
Published: February 2008

Introduction:

Foregut duplication cysts are heterotrophic rests of foregut-derived epithelium which are usually found in the abdomen and thorax; rarely are they found in the head and neck.

Case report:

We describe the case of a pharyngeal foregut duplication cyst presenting with airway obstruction in a neonate. We also review the pathology, investigation and management of this rare condition.

Discussion:

The occurrence of a foregut duplication cyst in the head and neck region mandates vigilance with respect to the airway. Magnetic resonance imaging is a useful part of pre-operative evaluation but cannot be relied upon for definitive diagnosis. Although foregut duplication cysts are benign lesions, definitive cure ultimately requires surgical excision, and this is often the means by which a definitive diagnosis is made. The prognosis for these lesions is excellent, with no reports in the literature of recurrence following excision.