bluuebunny/crossref_metadata_2025_split huggingface dataset:
‚Charlataneria Eruditorum’︁, Zur sozialen Semantik des gelehrten Betrugs im 17. und 18. Jahrhundert
Authors: Füssel Marian 
Published: June 2004

AbstractIn the 17th and 18th century republic of letters the problem of scientific fraud was met with a discourse of charlatanism. Departing from Johann Burckhard Menckes famous treatise on the Charlatanry of the learned the following essay traces how the accusations of academic and scientific misconduct put in terms of ‚charlatanry’︁ primarily helped to produce the new species of the erudite ‚charlatan’︁. Facing a growing complexity of scientific culture this new frame of meaning, structured by numerous examples of scientific misconduct offered a new way of orientation in the world of learning. But besides its cognitive impacts the discourse of charlatanry allowed to create symbolic boundaries, which determined decisions upon the affiliation or non affiliation to the new forming scientific community by separating honourable from dishonourable scientific personae. Speaking of charlatanry therefore always implied a social distinction as much as a scientific. The discourses on charlatanry also mirror differentiations within the scientific field. At first dominated by a critique built on courteous or bourgeois values, the scientific field later on developed its own criteria of appraisal like authorship, originality, transparency etc. Attracting the attention of a further growing public sphere, the explicit verbalisation of claims not relating to the value system of a republic of letters primarily concerned with the production and distribution of knowledge finally led up to a more implicit moral economy of science. A change that at a large scale level can be described both as an internalisation of the values of scientific conduct and a differentiation between justiciable and unjusticiable transgressions of the norms set up by the scientific community.
A Nonparametric Test for Random Dropouts
Authors: Listing Joachim , Schlittgen Rainer 
Published: June 2004

AbstractThe problem of dropout is a common one in longitudinal studies. One usually assumes for the analysis that dropout is at random. There are some tests to investigate this assumption. But these tests depend on normally distributed data or lack power, cf.ListingandSchlittgen(1998). We here propose an overall test which combines several Wilcoxon rank sum tests. The alternative hypothesis states that there is a tendency for larger (smaller) values of the target variable the last time the probands show up.The test is applicable with many ties also. It proves to perform well, compared to the test developed for normally distributed data, as well as to a test for completely missing at random which is proposed byLittle(1988). An application to real data is given too.
Statistical Inference For Risk Difference in an Incomplete Correlated 2 × 2 Table
Authors: Tang Nian‐Sheng , Tang Man‐Lai 
Published: June 2004

AbstractIn some infectious disease studies and 2‐step treatment studies, 2 × 2 table with structural zero could arise in situations where it is theoretically impossible for a particular cell to contain observations or structural void is introduced by design. In this article, we propose a score test of hypotheses pertaining to the marginal and conditional probabilities in a 2 × 2 table with structural zero via the risk/rate difference measure. Score test‐based confidence interval will also be outlined. We evaluate the performance of the score test and the existing likelihood ratio test. Our empirical results evince the similar and satisfactory performance of the two tests (with appropriate adjustments) in terms of coverage probability and expected interval width. Both tests consistently perform well from small‐ to moderate‐sample designs. The score test however has the advantage that it is only undefined in one scenario while the likelihood ratio test can be undefined in many scenarios. We illustrate our method by a real example from a two‐step tuberculosis skin test study.
Estimation of the Parameters of two Parallel Regression Lines Under Uncertain Prior Information
Authors: Khan Shahjahan 
Published: June 2004

AbstractThe problem of parallelism for bi‐linear regression lines arises in many real life investigations. For two linear regression models with normal errors, the estimation of the slope as well as the intercept parameters is considered when it is apriori suspected that the two lines are parallel. Three different estimators are defined by using both the sample data and the non‐sample uncertain prior information. The relative performances of the unrestricted, restricted and preliminary test estimators are investigated based on the analysis of the bias, and risk functions under quadratic loss. An example based on a medical study is used to illustrate the method.
College Presidents Examine Midlevel Management in the Community College
Authors: Gillet‐Karam Rosemary , Cameron Donald W. , Messina Robert C. , Mittelstet Stephen K. , Mulder Anne E. , Sykes Abel B. , Thornton Jerry Sue 
Published: June 2004

AbstractIn conversations with six community college presidents, issue editor Rosemary Gillet‐Karam asks about the definitions, roles, essential skills, and accomplishments of midlevel managers at their respective institutions.
Establishing and Sustaining a Middle College High School
Authors: Cunningham Cecilia L. , Wagonlander Chery S. 
Published: June 2004

AbstractSince 1973, middle college high schools, sponsored by local community colleges, have worked with local school districts as well as parents to create unique learning enviroments for at‐risk youth. This chapter provides a model for the planning and operation of a new institution based on Middle College at LaGuardina Community College (New York) and Mott Middle College at Mott Community College (Michigan).
Electron Delocalization and Electrostatic Repulsion at the Origin of the Strong Spin Coupling in Mixed‐Valence Keggin Polyoxometalates: Ab Initio Calculations of the One‐ and Two‐Electron Processes
Authors: Suaud Nicolas , Gaita‐Ariño Alejandro , Clemente‐Juan Juan Modesto , Coronado Eugenio 
Published: June 2004

AbstractWe present here a general theoretical procedure to treat the problem of electron delocalization and magnetic interactions in high‐nuclearity mixed valence clusters based on polyoxometalates. The main interactions between the delocalized electrons of mixed‐valence polyoxometalate anions are extracted from valence spectroscopy ab initio calculations on embedded fragments. Electron transfer, magnetic coupling and exchange transfer parameters between nearest and next‐nearest‐neighbor metal ions, as well as the value of the electrostatic repulsion between pairs of metal ions are determined. These parameters are introduced in a model Hamiltonian that considers the whole anion. It thus provides macroscopic properties that should be compared with the experimental data. This method is applied to a two‐electron‐reduced polyoxowolframate Keggin anion. The results demonstrate that the electron transfer processes, combined with the Coulombic repulsion between the “extra” electrons, induce a strong antiferromagnetic coupling between the two delocalized spins providing a definite explanation of the diamagnetic properties of these high nuclearity mixed‐valence clusters.
Endurance Limit of Ground and TIG Dressed Steel Welded Joints under Proportional Loading
Authors: Rudolph J. 
Published: June 2004

AbstractPost weld treatment methods such as disk and burr grinding or TIG dressing improve the fatigue performance of steel welded joints. As the crack like defects at the weld toes are removed, a significant increase in fatigue strength and particularly in the endurance limit is achieved. This improvement in the fatigue behaviour is currently considered by bonus factors based on general experimental observations. No code‐based design approach for the assessment of the endurance limit of these components is available currently. As the fatigue behavior of these types of welded joints is similar to that of non‐welded and notched components established design methodologies, such as the local strain approach, are appropriate tools for these purposes. Furthermore, this design approach is open to extension to the finite life region and even the low cycle fatigue regime.
Solid‐state NMR spectra with sharp principal value features of the chemical shift tensor
Authors: Gardiennet Carole , Tekely Piotr 
Published: June 2004

AbstractA straightforward, albeit still unexploited, approach to access sharp principal value features of the chemical shift tensor in slightly off‐magic angle, slowly spinning powder solids is revisited. Its major advantages consist of (i) the direct visualization of axial or more general tensor/site symmetry, (ii) the absence of any rotor‐synchronized or amplitude‐matched radiofrequency pulse, and (iii) the use of routine single‐pulse or cross‐polarization acquisition modes upon modest spinning speeds on a standard cross‐polarization/magic‐angle spinning probe. The experiments and simulations show that the principal value features remain well resolved in an easily accessible range of chemical shift anisotropy/spinning frequency ratios and have fixed spectral positions at different spinning speeds. Several useful applications of this simple and robust approach can be envisaged in organic and inorganic solids. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 22A: 106–112, 2004
13C CP/MAS: Application to glycine
Authors: Taylor Robert E. 
Published: June 2004

AbstractIn a previous article (Concepts Magn Reson 22A(1) 37–49 (2004)), the initial setup of the 13C CP/MAS experiment was described. The advantages of the experiment over direct 13C excitation were also given. In this article, the experiment is applied to three polymorphic structures of glycine. Temperature calibration of the experiment to investigate molecular dynamics as a function of temperature is also described. Though the 13C CP/MAS experiment is widely applicable, it cannot be universally used. The 13C CP/MAS experiment works at ambient temperature for both the α and γ polymorphic structures of glycine. However, the cross‐polarization technique fails to provide a signal at low temperature from either polymorph. The failure of the technique for both polymorphs arises from the shortened 1H T1ρ at low temperatures. This shortened T1ρ results from the hindered rotation of the −NH3 group. The technique even fails at ambient temperature for β‐glycine. Again, the reason is a shortened 1H T1ρ. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 22A: 79–89, 2004
Concepts and tools for NMR restraint analysis and validation
Authors: Nabuurs Sander B. , Spronk Chris A.E.M. , Vriend Gert , Vuister Geerten W. 
Published: June 2004

AbstractThe quality of NMR‐derived biomolecular structure models can be assessed by validation on the level of structural characteristics as well as the NMR data used to derive the structure models. Here, an overview is given of the common methods to validate experimental NMR data. These methods provide measures of quality and goodness of fit of the structure to the data. A detailed discussion is given of newly developed methods to assess the information contained in experimental NMR restraints, which provide powerful tools for validation and error analysis in NMR structure determination. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 22A: 90–105, 2004.
A quadrature lowpass birdcage coil for a vertical low field MRI scanner
Authors: Giovannetti Giulio , Francesconi Raffaello , Landini Luigi , Viti Vittorio , Santarelli Maria Filomena , Positano Vincenzo , Benassi Antonio 
Published: June 2004

AbstractBirdcage coils are widely used in magnetic resonance imaging (MRI) applications for their ability to operate in transmit/receive mode with high signal‐to‐noise ratio and wide homogeneous field. When used in horizontal bore MRI systems, the birdcage coil is able to produce circular polarized field using quadrature excitation, thus reaching SNR improvement of √2 as maximum value. In a previous article, the highpass birdcage coil was employed in a vertical bore MRI scanner by combining the sinusoidal and the end‐ring resonant modes. In this article, we investigated the lowpass birdcage coil configuration to operate with a vertical bore MRI system, producing two B1 fields components perpendicular to the vertical B0 field. Its implementation is convenient because it requires one‐half capacitors with respect to the highpass design. Moreover, at low field, the high near‐electric field losses, which are the main disadvantage of the lowpass design, can be neglected. Experiments performed on a quadrature birdcage coil prototype mounted on an open MRI scanner showed that SNR and homogeneity degree increase with respect to the linear birdcage. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 22B: 1–6, 2004.
Modal analysis and acoustic noise characterization of a 4T MRI gradient coil insert
Authors: Mechefske C.K. , Yao G. , Li W. , Gazdzinski C. , Rutt B.K. 
Published: June 2004

AbstractHigh magnetic field strength and high‐speed gradient coil current switching are combining to yield high acoustic sound pressure levels (SPL) in and around magnetic resonance imaging (MRI) scanners. Studies have already been conducted that partially characterize this sound field, and various methods have been investigated in an attempt to attenuate the noise generated. To more fully characterize and predict the vibration and acoustic response of a gradient coil inside a scanner, a series of finite element analysis (FEA), vibro‐acoustic analysis, and experimental measurements were carried out. The FEA and vibro‐acoustic model used was based on specific internal and external structural dimensions and the material physical properties of a gradient coil insert. The model‐based results were verified through experimental vibration and acoustic testing of the same gradient coil. It was found that the experimental analysis results were in good agreement with the model‐based results in all cases. The numerical methods developed in this study could provide a basis for the virtual testing of gradient coil designs that will allow the prediction of vibration and acoustic behavior. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 22B: 37–49, 2004
Simultaneous NMR microimaging of multiple single‐cell samples
Authors: Purea A. , Neuberger T. , Webb A.G. 
Published: June 2004

AbstractNuclear magnetic resonance (NMR) microimaging experiments performed on small samples such as single cells typically require long data acquisition times and are usually carried out on high‐field systems with limited access time. When using small probe coils on millimetre (or smaller) size scale to study single cells, it is desirable to take advantage of the comparatively large volume of homogeneous static magnetic field within the magnet to increase the efficiency of NMR data acquisition. Here we describe the development of a four‐channel probehead that consists of four individual solenoid coils (length 2.8 mm, outer diameter 2 mm) stacked along the z axis. The probehead was designed for a 17.6 Tesla (750 MHz) wide‐bore magnet, and operates within a 40 mm inner diameter gradient set with maximum strength 1 Tesla per metre. We performed simulations to estimate the impact of shielding between the coils on the B1 field distribution. Results showed that for coil‐shield separations on the order of a coil radius, no significant change in B1 homogeneity is expected, and therefore coils were spaced accordingly. Coil isolation of greater than 35 dB was achieved for all coils, and the Q values were ∼160 unloaded and ∼60 loaded with 100 mM NaCl solution. Practical use of the probehead was demonstrated by obtaining simultaneously four three‐dimensional T1 maps of chemically fixed Xenopus laevis oocytes at a spatial resolution of 30 × 60 × 60 μm. The T1 values for the nucleus were ∼2.7 seconds, and the animal pole ∼1.2 seconds. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 22B: 7–14, 2004.
Intestinal tumor and agmatine (decarboxylated arginine)
Authors: Molderings Gerhard J. , Kribben Bettina , Heinen Anja , Schröder Detlev , Brüss Michael , Göthert Manfred 
Published: June 2004

AbstractBACKGROUNDThe polyamine system is a promising target for anticancer therapy. Ideally, an antineoplastic compound affecting this system should inhibit both ornithine decarboxylase and the polyamine transporter, and toxicity should be mild. Agmatine, decarboxylated L‐arginine, appears to be such a compound.METHODSAdenosine triphosphate levels and the protein content of cell populations in culture were identified as surrogate markers for cell count. Agmatine content in cells and tissue specimens was measured by high‐performance liquid chromatography. Antizyme levels were estimated by Western blotting.RESULTSAgmatine inhibited the proliferation of six human intestinal tumor cell lines in a concentration‐dependent manner; this inhibition probably was attributable to an interaction between agmatine and the intracellular polyamine system. Consistent with the inverse relation between cell proliferation and agmatine concentration was the finding that agmatine content in human colon carcinoma tissue was approximatly one‐half as great as it was in adjacent macroscopically normal tissue.CONCLUSIONSThe results of the current study were compatible with the hypothesis that agmatine possesses antineoplastic action against intestinal tumor cells. It is likely that this activity is attributable to agmatine's regulatory role in polyamine homeostasis. Cancer 2004. © 2004 American Cancer Society.
Depression, cigarette smoking, and hematopoietic stem cell transplantation outcome
Authors: Chang Grace , John Orav E. , McNamara Tay , Tong Mei‐Yee , Antin Joseph H. 
Published: June 2004

AbstractBACKGROUNDThe relationships between psychological and behavioral variables and patient outcomes after hematopoietic stem cell transplantation (HSCT) are not known definitively but have great potential importance, since this lifesaving procedure is used increasingly to treat a variety of malignancies. The objective of this study was to evaluate psychosocial predictors of long‐term survival and disease recurrence after patients underwent allogeneic HSCT for chronic myelogenous leukemia (CML).METHODSIn this prospective cohort study, 114 adults were admitted for allogeneic HSCT to the Brigham and Women's Hospital between July, 1997 and January, 2002. The median follow‐up was 882 days, and serial measures were taken for mood and substance use 6 months and 12 months posttransplantation.RESULTSWith a 93% participation rate by all potentially eligible patients and with < 3% of patients loss to follow‐up, univariate predictors of long‐term survival and recurrence were identified. Cox proportional hazards regression models for survival and recurrence were developed. Depressive symptoms, as measured by the most recent Beck Depression Inventory (BDI), increased the risk of death by 7% for each point increase in the BDI score (P = 0.006). Fourteen of 17 patients who developed recurrent disease were cigarette smokers with an average of 22.3 pack‐years. For each pack‐year of cigarette smoking, the risk of recurrence increased by 1.7% (P = 0.01).CONCLUSIONSThis study assessed the role of psychosocial variables prospectively among a clinically homogeneous but representative cohort of patients who underwent allogeneic HSCT. Although additional confirmatory studies are pending, it appears that depressive symptoms posttransplantation and cigarette smoking prior to transplantation affect outcomes adversely and may represent opportunities to improve the morbidity and mortality associated with HSCT for patients with CML. Cancer 2004. © 2004 American Cancer Society.
Estimation of an optimal radiotherapy utilization rate for gastrointestinal carcinoma
Authors: Delaney Geoff , Barton Michael , Jacob Susannah 
Published: June 2004

AbstractBACKGROUNDRadiotherapy utilization rates for cancer vary widely, both within and between countries. The optimal proportion of patients with gastrointestinal malignancies who should receive at least one course of radiotherapy at some time during their illness is an important benchmark.METHODSThe authors studied treatment guidelines and treatment reviews to identify the indications for radiotherapy for patients with gastrointestinal malignancies. Optimal radiotherapy utilization trees were constructed to show the clinical attributes of patients with gastrointestinal carcinomas who will benefit from radiotherapy. Epidemiologic incidence data for each of these clinical attributes were obtained to calculate the optimal proportion of all patients with gastrointestinal malignancies for whom radiotherapy was considered appropriate. Optimal rates of radiotherapy use were compared with actual rates in population‐based studies to assess any discrepancies between actual and optimal radiotherapy utilization rates.RESULTSRadiotherapy was indicated in 80% of patients with esophageal carcinoma, 68% of patients with gastric carcinoma, 57% of patients with pancreatic carcinoma, 13% of patients with carcinoma of the gallbladder, 0% of patients with hepatic carcinoma, 14% of patients with colon carcinoma, and 61% of patients with rectal carcinoma. The actual radiotherapy utilization rates for most of these gastrointestinal malignancies fell well short of optimal rates, which were derived from evidence‐based treatment guidelines.CONCLUSIONSIt is possible to model optimal radiotherapy utilization using published treatment guidelines and existing incidence data. There was a discrepancy between the optimal and actual rates of radiotherapy utilization for patients with carcinomas of the esophagus, stomach, pancreas, and rectum. Strategies to implement evidence‐based clinical guidelines are recommended. Cancer 2004. © 2004 American Cancer Society.
Estimation of an optimal radiotherapy utilization rate for gynecologic carcinoma
Authors: Delaney Geoff , Jacob Susannah , Barton Michael 
Published: June 2004

AbstractBACKGROUNDRadiotherapy utilization rates for cancer vary widely, both within and between countries. Current estimates of the proportion of cancer patients who should optimally receive radiotherapy are based either on expert opinion or on the measurement of actual utilization rates, rather than on the best scientific evidence.METHODSEvidence‐based treatment guidelines regarding endometrial carcinoma were reviewed to develop an evidence‐based benchmark for radiotherapy utilization. An optimal radiotherapy utilization tree was constructed and the proportions of endometrial carcinoma patients with clinical indications for radiotherapy were obtained from epidemiologic data. The ideal utilization rates were compared with actual radiotherapy utilization rates for endometrial carcinoma both in Australia and internationally.RESULTSAccording to the best available evidence, radiotherapy is indicated at least once in 46% of all patients with endometrial carcinoma. A review of the limited data available concerning actual radiotherapy utilization rates revealed that the actual rates are approximately 10% lower than the optimal rates.CONCLUSIONSFurther research into the patterns of actual treatment and the development of optimal chemotherapy and surgery utilization rates for endometrial carcinoma is recommended. The difference between the optimal and the actual utilization rates warrants investigation into the reasons for the low radiotherapy utilization rates encountered in clinical practice. Cancer 2004. © 2004 American Cancer Society.