bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of lambda‐cyhalothrin on mosquito larvae and predatory aquatic insects
Authors: Lawler Sharon P , Dritz Deborah A , Christiansen Julie A , Cornel Anthony J 
Published: August 2006

AbstractAgricultural insecticides can affect mosquito production in rice fields by controlling mosquitoes, disrupting biological control or contributing to selection of insecticide resistance. The duration of insecticidal activity of the pyrethroid lambda‐cyhalothrin was quantified on predatory insects in rice fields and on three kinds of mosquito larva: a pyrethroid‐susceptible strain of Culex tarsalis Coquillet, a pyrethroid‐resistant strain of Cx pipiens L. (sensu lato) and non‐resistant Cx pipiens s.l. Lambda‐cyhalothrin killed most caged, susceptible mosquitoes for up to 21 days. It killed fewer resistant Cx pipiens s.l., but suppressed their survival for over a week. Lambda‐cyhalothrin suppressed field populations of predatory insects through day 29. Agricultural use of lambda‐cyhalothrin can provide incidental mosquito control. However, the pyrethroid persisted in sediment and gradually decreased in activity, which could contribute to selection of pyrethroid‐resistant mosquitoes. Because caged mosquitoes showed good survival before predators recovered, disruption of biological control is possible. It is therefore advisable for growers and mosquito control agencies to communicate about pesticide use. Copyright © 2006 Society of Chemical Industry
Electrical conductivity of prelocalized graphite‐filled blend of polyvinyl chloride/styrene acrylonitrile composites in relationship to morphology and hardness
Authors: Sachdev V. K. , Srivastava N. K. , Panwar Varij , Singh H. , Mehra N. C. , Mehra R. M. 
Published: August 2006

AbstractAt present there is a greater need to design conducting polymeric composites that suit particular application with little compromise on mechanical properties. This work deals with the study of electrical conductivity and mechanical strength of graphite‐filled blend of polyvinyl chloride/styrene acrylonitrile (PVC/SAN) composites. Samples were prepared by prelocalization of graphite onto the particles of PVC and SAN with subsequent compression molding. At a fixed volume ratio of 1:1 of PVC/SAN, percolation threshold of 0.0063 volume fraction of graphite has been observed. SAN has improved the D‐shore hardness of composites. Composites with more than 3 wt% graphite content have good conductivity and still preserve a reasonable mechanical strength. Conductivity patterns suggest higher affinity of graphite for PVC as compared to SAN. Scanning electron microscopy (SEM) micrographs indicate the widening of graphite layers with increasing graphite content. The electrical conductivity of composites has been explained in terms of percolation theory. The universal exponent t is found to be 3.09 for a best‐fit value of percolation threshold of 0.0057 volume fraction of graphite. There is good agreement between calculated and experimental values. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective Hamiltonian for potassium dynamics in the β ‐pyrochlore superconductor KOs2O6
Authors: Kuneš J. , Pickett W. E. 
Published: August 2006

AbstractBased on ab initio energies and forces we construct an effective Hamiltonian for anharmonic dynamics of potassium cations in the β ‐pyrochlore compound KOs2O6. We solve numerically the single‐site problem which is characterized by an extremely flat potential well allowing for large excursions of K‐ions, and illustrate graphically the K‐ion wavefunctions in the four off‐center (symmetry‐breaking) sites. These large displacements from the ideal lattice site result in sizable K–K near‐neighbor interactions through a screened Coulomb interaction. The matrix elements of the interaction in the basis of single‐site eigenstates are calculated and discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epitaxial vapor–liquid–solid growth of silicon nano‐whiskers by electron beam evaporation
Authors: Sivakov V. , Andrä G. , Gösele U. , Christiansen S. 
Published: August 2006

AbstractEpitaxial silicon nanowhiskers (NWs) were grown on Si(111) substrates by electron beam evaporation (EBE) in a non‐ultra high vacuum environment (base pressure 1–2 × 10–7 Torr). Comparably low growth temperatures between 575 and 675 °C were realized making use of the gold driven 1D growth by the vapor‐liquid‐solid (VLS) growth mechanism. Diameters and lengths of the NWs were observed in the ranges between 50 and 200 nm and 200 and 670 nm, respectively. A maximum NW growth velocity of 5 nm/min was realized for the evaporation current of 35 mA. This value determines particle flux and thus growth velocity and is at the lower end of evaporation currents studied so far. But a value that yields a growth velocity comparable to the one realized by the more intensively studied ultra‐high vacuum molecular beam epitaxy (MBE) method. The EBE NW morphology, defect structure and the interface between NWs and substrate are characterized by scanning and transmission electron microscopy (SEM, TEM) techniques. The NW material from EBE is compared to NWs grown by MBE and similarities and differences are pointed out. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new Li2O–Nb2O5–TiO2 microwave dielectric ceramic composite
Authors: Zeng Qun , Li Wei , Shi Jian‐lin , Guo Jing‐kun 
Published: August 2006

AbstractIn the Li2O–Nb2O5–TiO2 (LNT) system, a new dielectric ceramic composite with special structure has been found and investigated. The compound is composed of two phases, the “M‐phase” and Li2TiO3 solid solution phase. This ceramic composite has a low sintering temperature (∼1100 °C) and good microwave dielectric properties of high permittivity (∼49), high Q × f value up to 9500 GHz, and small tempe‐ rature coefficient (∼22 ppm/°C). Furthermore, by adding 1 wt% B2O3, the ceramic could be densified at very low sintering temperatures (≯900 °C) and also have good microwave dielectric properties of ϵ r = 49.2, Q × f = 8839 GHz, which suggests that the ceramic could be a promising candidate for multilayer low‐temperature co‐fired ceramics applications. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A sequential procedure for monitoring clinical trials against historical controls
Authors: Xiong Xiaoping , Tan Ming , Boyett James 
Published: August 2006

AbstractIn this paper, we develop a sequential procedure to monitor clinical trials against historical controls. When there is a strong ethical concern about randomizing patients to existing treatment because biological and medical evidence suggests that the new treatment is potentially superior to the existing one, or when the enrollment is too limited for randomization of subjects into experimental and control groups, one can monitor the trial sequentially against historical controls if the historical data with required quality and sample size are available to form a valid reference for the trial. This design of trial is sometimes the only alternative to a randomized phase III trial design that is intended but not feasible in situations such as above. Monitoring this type of clinical trial leads to a statistical problem of comparing two population means in a situation in which data from one population are sequentially collected and compared with all data from the other population at each interim look. The proposed sequential procedures is based on the sequential conditional probability ratio test (SCPRT) by which the conclusion of the sequential test would be virtually the same as that arrived at by a non‐sequential test based on all data at the planned end of the trial. We develop the sequential procedure by proposing a Brownian motion that emulates the test statistic, and then proposing an SCPRT that is adapted to the special properties of the trial. Copyright © 2006 John Wiley & Sons, Ltd.
Instrumental variables and interactions in the causal analysis of a complex clinical trial
Authors: Bond Simon J. , White Ian R. , Sarah Walker A. 
Published: August 2006

AbstractWe consider the application of instrumental variable techniques in a longitudinal clinical trial in paediatric HIV/AIDS, with a substantial degree of non‐compliance to randomized treatment (Nelfinavirversusplacebo) and with left censoring of the outcome variable (HIV RNA concentration). We consider in detail the assumptions and implications behind the inclusion and exclusion of interactions between randomized arm and baseline covariates in modelling actual treatment received, and between treatment and baseline covariates in modelling outcome. Estimated treatment effects were sensitive to inclusion of interactions, and we show how such sensitivity can be explored and explained. Copyright © 2006 John Wiley & Sons, Ltd.
Performance of adaptive sample size adjustment with respect to stopping criteria and time of interim analysis
Authors: Jahn‐Eimermacher Antje , Hommel Gerhard 
Published: August 2006

AbstractThe benefit of adjusting the sample size in clinical trials on the basis of treatment effects observed in interim analysis has been the subject of several recent papers. Different conclusions were drawn about the usefulness of this approach for gaining power or saving sample size, because of differences in trial design and setting. We examined the benefit of sample size adjustment in relation to trial design parameters such as ‘time of interim analysis’ and ‘choice of stopping criteria’. We compared the adaptive weighted inverse normal method with classical group sequential methods for the most common and for optimal stopping criteria in early, half‐time and late interim analyses. We found that reacting to interim data might significantly reduce average sample size in some situations, while classical approaches can out‐perform the adaptive designs under other circumstances. We characterized these situations with respect to time of interim analysis and choice of stopping criteria. Copyright © 2006 John Wiley & Sons, Ltd.
An overall strategy based on regression models to estimate relative survival and model the effects of prognostic factors in cancer survival studies
Authors: Remontet L. , Bossard N. , Belot A. , Estève J. ,   the French network of cancer registries FRANCIM
Published: August 2006

AbstractRelative survival provides a measure of the proportion of patients dying from the disease under study without requiring the knowledge of the cause of death. We propose an overall strategy based on regression models to estimate the relative survival and model the effects of potential prognostic factors. The baseline hazard was modelled until 10 years follow‐up using parametric continuous functions. Six models including cubic regression splines were considered and the Akaike Information Criterion was used to select the final model. This approach yielded smooth and reliable estimates of mortality hazard and allowed us to deal with sparse data taking into account all the available information. Splines were also used to model simultaneously non‐linear effects of continuous covariates and time‐dependent hazard ratios. This led to a graphical representation of the hazard ratio that can be useful for clinical interpretation. Estimates of these models were obtained by likelihood maximization. We showed that these estimates could be also obtained using standard algorithms for Poisson regression. Copyright © 2006 John Wiley & Sons, Ltd.
New Sizing Agents and Flocculants Derived From Chitosan
Authors: Hebeish Ali , Higazy Asha , El‐Shafei Amira 
Published: August 2006

AbstractApproaches for development of novel textile sizing agents and flocculants based on acid‐hydrolyzed and carboxymethylated chitosans were undertaken. Factors affecting both hydrolysis and carboxymethylation were investigated. Aqueous solutions of hydrolyzed chitosans or carboxymethyl chitosans were applied to light cotton to test the feasibility of such water‐soluble chitosans for textile sizing. The size add‐on on the light fabric is directly related to the concentration of the hydrolyzed or carboxymethyl chitosan in the sizing solution and so does the apparent viscosity of the latter. Hundred percent size removal could be achieved with the hydrolyzed chitosans. A different situation was encountered with carboxymethyl chitosan where the percent size removal increases from 81% to 95% by increasing its concentration in the sizing solution from 5% to 15%. The tensile strength of the sized fabrics increased by about 55% and the elongation at break decreased on average by about 3%. The suitability of the hydrolyzed chitosans and carboxymethyl chitosans as flocculants was also investigated. The degree of flocculation was followed at different pHs by determination of the transmission%. Efficiency of flocculation at pH 6 was greater than at pH 8.
Search‐based software test data generation for string data using program‐specific search operators
Authors: Alshraideh Mohammad , Bottaci Leonardo 
Published: August 2006

AbstractThis paper presents a novel approach to automatic software test data generation, where the test data is intended to cover program branches which depend on string predicates such as string equality, string ordering and regular expression matching. A search‐based approach is assumed and some potential search operators and corresponding evaluation functions are assembled. Their performance is assessed empirically by using them to generate test data for a number of test programs. A novel approach of using search operators based on programming language string operators and parameterized by string literals from the program under test is introduced. These operators are also assessed empirically in generating test data for the test programs and are shown to provide a significant increase in performance. Copyright © 2006 John Wiley & Sons, Ltd.
A 7‐year Experience with Thoracoscopic Sympathectomy for Critical Upper Limb Ischemia
Authors: Lee Arvind Dhas , Agarwal Sunil , Sadhu David 
Published: August 2006

AbstractBackgroundSeverely symptomatic arterial insufficiency of an upper limb not suitable for revascularization is a difficult condition to manage. Thoracoscopic sympathectomy (TS) can be an effective procedure in this setting.MethodsOur experience with 18 consecutive thoracoscopic sympathectomy (TS) procedures over a period of 7 years has been reviewed. Indications, operative technique, complications, and outcome of surgery are analyzed.ResultsWe performed 18 TS procedures on 17 patients during this period. There were no deaths. One patient had intraoperative hemorrhage necessitating conversion to open thoracotomy. Mean postoperative hospital stay was 2.3 days. Follow‐up ranged from 6 to 72 months. All patients demonstrated clinical benefit from the procedure.ConclusionsThoracoscopic sympathectomy is a useful option in patients with severely symptomatic hand and digital ischemia from occlusive small arterial disease like thromboangitis obliterans.
Diagnosis and Treatment of Gastric Heterotopic Pancreas
Authors: Ormarsson Orri Thor , Gudmundsdottir Ingibjorg , Mårvik Ronald 
Published: August 2006

AbstractBackgroundHeterotopic pancreas (HP) in the stomach can be difficult to diagnose and there are many treatment options. The aim of this article is to review the contemporary diagnosis of and treatment options for HP in the stomach.MethodsWe undertook a retrospective review of patients with the diagnosis heterotopic pancreas registered at St. Olavs University Hospital in Trondheim from 1990 to 2002. We report on clinical findings, provide a histological review, and summarize the literature with particular emphasis on the diagnosis and treatment of HP in the stomach.ResultsWe found 32 cases, most of them in the stomach and the small intestine. Sixteen patients were symptomatic. A histological examination showed that most of the tumors were submucosal and had the appearance of normal pancreas tissue.ConclusionGastric HP is not an uncommon diagnosis compared with many other gastric tumors and should more often be considered as a differential diagnosis. Symptom correlation is not always easy to determine, but symptom relief after treatment is well established. An endoscopic ultrasound examination may help when screening patients for extended biopsy and in deciding on which type of operation is to be performed. When treated, minimally invasive techniques should be applied.
Electronic structures of GaAs/Al
x
Ga1-x
As quantum double rings
Authors: Li Shu-Shen , Xia Jian-Bai 
Published: August 2006

Abstract
In the framework of effective mass envelope function theory, the electronic structures of GaAs/Al
x
Ga1-x
As quantum double rings (QDRs) are studied. Our model can be used to calculate the electronic structures of quantum wells, wires, dots, and the single ring. In calculations, the effects due to the different effective masses of electrons and holes in GaAs and Al
x
Ga1-x
As and the valence band mixing are considered. The energy levels of electrons and holes are calculated for different shapes of QDRs. The calculated results are useful in designing and fabricating the interrelated photoelectric devices. The single electron states presented here are useful for the study of the electron correlations and the effects of magnetic fields in QDRs.
Cardiomyocyte apoptosis is related to left ventricular dysfunction and remodelling in dilated cardiomyopathy, but is not affected by growth hormone treatment
Authors: Ibe Waltraut , Saraste Antti , Lindemann Stephan , Bruder Stephanie , Buerke Michael , Darius Harald , Pulkki Kari , Voipio‐Pulkki Liisa‐Maria 
Published: August 2006

AbstractBackground and aimsCardiomyocyte apoptosis (CA) is a common feature of end‐stage heart failure. We examined whether CA is associated with cardiac dysfunction and remodelling in heart failure due to dilated cardiomyopathy and studied the effect of human growth hormone (hGH) on CA.Methods and resultsWe studied 38 patients, included in a phase III multi‐center, randomised, double‐blind and placebo‐controlled trial of biosynthetic hGH treatment in dilated cardiomyopathy, at baseline and after 14 weeks treatment. Twenty‐six patients received hGH and 12 received placebo. CA was quantified in endomyocardial biopsies using the TUNEL assay. CA correlated with left ventricular size (r=0.43, p=0.007). Compared to patients with CA below the median of 0.53%, patients with CA above the median had significantly larger left ventricular volumes and lower ejection fractions (EF) by echocardiography (median (interquartile range)) 200 ml (84) vs. 257 ml (134) and 27% (11) vs. 23% (9). Expression of the Fas receptor was associated with a high rate of CA. hGH treatment significantly increased serum IGF‐1 levels, but it had no effect on CA or cardiac structure and function.ConclusionCA is related to left ventricular enlargement and dysfunction in dilated cardiomyopathy. CA is not affected by short‐term treatment with hGH.
Effect of hypnotic suggestion on fibromyalgic pain: Comparison between hypnosis and relaxation
Authors: Castel Antoni , Pérez Magdalena , Sala José , Padrol Anna , Rull Maria 
Published: August 2006

AbstractThe main aims of this experimental study are: (1) to compare the relative effects of analgesia suggestions and relaxation suggestions on clinical pain, and (2) to compare the relative effect of relaxation suggestions when they are presented as “hypnosis” and as “relaxation training”. Forty‐five patients with fibromyalgia were randomly assigned to one of the following experimental conditions: (a) hypnosis with relaxation suggestions; (b) hypnosis with analgesia suggestions; (c) relaxation. Before and after the experimental session, the pain intensity was measured using a visual analogue scale (VAS) and the sensory and affective dimensions were measured with the McGill Pain Questionnaire. The results showed: (1) that hypnosis followed by analgesia suggestions has a greater effect on the intensity of pain and on the sensory dimension of pain than hypnosis followed by relaxation suggestions; (2) that the effect of hypnosis followed by relaxation suggestions is not greater than relaxation. We discuss the implications of the study on our understanding of the importance of suggestions used in hypnosis and of the differences and similarities between hypnotic relaxation and relaxation training.
Tracheobronchial foreign body aspiration: A continuing challenge
Authors: Soysal Omer , Kuzucu Akin , Ulutas Hakki 
Published: August 2006

ObjectiveThe aim was to present the features and outcomes for 140 cases of foreign body aspiration and to discuss specific problems and new management recommendations.Study Design and SettingRecords were retrospectively reviewed and the following data were recorded for each patient: age, sex, symptoms, duration of symptoms, findings on physical examination and chest radiography, location and type of foreign body, complications related to aspiration itself or to extraction, and outcome.ResultsSeventy‐eight patients presented within 24 hours of aspiration. The most common symptoms and findings were cough, dyspnea‐stridor, decreased breath sounds, radiopaque foreign body, air trapping, and atelectasis. All 140 patients underwent rigid bronchoscopy, and 110 had the foreign material extracted via the scope. No foreign body was detected bronchoscopically in 25 cases. In the other 5 cases, the material was visualized but could not be removed via the scope, and 3 of these patients required thoracotomy for removal. Eleven patients developed morbidity after bronchoscopy.ConclusionHistory suggestive of foreign body aspiration is a definite indication for bronchoscopy, and bronchoscopic extraction should only be performed by experts. Each case tends to present different challenges, and endotracheal intubation and tracheotomy may be required.
Acoustic parameters of snoring sound to assess the effectiveness of sleep nasendoscopy in predicting surgical outcome
Authors: Jones Terry M. , Walker Paul , Ho Meau‐Shin , Earis John E. , Swift Andrew C. , Charters Peter 
Published: August 2006

ObjectiveTo assess the effectiveness of two grading systems used to predict surgical outcome in nonapneic snorers.Study DesignA prospective observational study. Prior to undergoing palatal surgery, 20 patients completed a sleep nasendoscopic examination involving sequential steady‐state sedation with intravenous propofol. Using a combination of acoustic parameters of snoring sound as an objective outcome measurement, and the answers to a specifically designed questionnaire as a subjective outcome measurement, the effectiveness of each grading system in predicting surgical outcome was examined.ResultsDepending on the outcome measurement used, sensitivity in predicting success of surgery for snoring varied from 16.7% to 50.0% and specificity from 38.5% to 62.5% for the Pringle and Croft system, while sensitivity varied from 91.7% to 100% and specificity from 30.8% to 31.5% for the Camilleri system.ConclusionSleep nasendoscopy using these classifications cannot be recommended as a reliable predictor of surgical outcome in nonapneic snorers.EBM rating: C‐4