cssi/SciSciGPT-SciSciNet huggingface dataset:
High Resolution Separation of Proteins in a Polymeric Micro-Fluidic Chip

An integrated micro-fluidic chip has been developed using Poly-di-methyl siloxane (PDMS) to separate proteins by isoelectric focusing (IEF). Soft lithography techniques, which offer rapid prototyping, easy multilayer fabrication, mass production capability and biocompatibility, were utilized to fabricate various parts of the micro-fluidic chip. Separately molded PDMS layers were bonded together to form three-dimensional microfluidic chips. The microfluidic chips were prepared for IEF by conditioning the channel with 1 M NaOH and then loading it with a solution of fluorescent proteins made using 0.4% MC, 4% broad-range ampholyte and 0.018 mg/ml protein in 18 MOhm water. Relatively large reservoirs on the acidic and basic ends of the channel were filled with anolyte (50 mM phosphoric acid) and catholyte (50 mM sodium hydroxide), respectively, and then current was applied along the axis of the channel until one or more bands of protein focused, usually in just a few minutes even at relatively low voltages. The focused bands were generally well-formed with sharp edges and were less than 100 microns across yielding a putative peak capacity in excess of 100 peaks in a 2-cm long channel.© 2003 ASME
Optimal Multi-Impulse Orbit Transfer Using Nonlinear Relative Motion Dynamics

Trajectory planning for satellite formation flying missions requires the ability to find the optimal control law to transfer a satellite from one periodic relative orbit to another. This article modifies Jezewski’s linear impulsive trajectory optimization method for solving nonlinear problems described in the relative coordinate frame, and proposes the concept of standard problems for the initialization of the optimizer. With this modified optimizer and the standard problem concept, the article studies the impulse number, the cost, and the nonlinearity of fixed-time coplanar transfer problems.
Identification of a potential membrane-targeting region of the replication initiator protein (TrfA) of broad-host-range plasmid RK2.

Plasmid RK2 codes for two species of the replication initiator protein TrfA (33 and 44 kDa). Both polypeptides are strongly associated with membrane fractions of Escherichia coli host cells (W. Firshein and P. Kim, Mol. Microbiol. 23, 1-10, 1997). We investigated the role of a 12-amino-acid hydrophobic region (HR) in the membrane association of TrfA. Epitope-tagged polypeptide fragments of TrfA that contained HR were expressed and found to be associated with membrane fractions. Site-directed mutagenesis of trfA revealed that changes of specific amino acids in HR can affect both TrfA association with the membrane and its ability to support replication of an RK2 oriV plasmid in vivo. These results are consistent with the hypothesis that membrane association of TrfA is functionally relevant and that the HR region of TrfA is involved in membrane association and DNA replication in vivo.
Distances as degrees of freedom.

Tertiary contact distance information of varying resolution for large biological molecules abounds in the literature. The results provided herein develop a framework by which information of this type can be used to reduce the allowable configuration space of a macromolecule. The approach combines graph theory and distance geometry. Large molecules are represented as simple, undirected graphs, with atoms, or groups, as vertices, and distances between them as edges. It is shown that determination of the exact structure of a molecule in three dimensions only requires the specification of all the distances in a single tetrahedron, and four distances to every other atom. This is 4N-10 distances which is a subset of the total N(N-1)/2 unique distances in a molecule consisting of N atoms. This requirement for only 4N-10 distances has serious implications for distance geometry implementations in which all N(N-1)/2 distances are specified by bounded random numbers. Such distance matrices represent overspecified systems which when solved lead to non-obvious distribution of any error caused by inherent contradictions in the input data. It is also shown that numerous valid subsets of 4N-10 distances can be constructed. It is thus possible to tailor a subset of distances using all known distances as degrees of freedom, and thereby reduce the configuration space of the molecule. Simple algebraic relationships are derived that relate sets of distances, and complicated rotations are avoided. These relationships are used to construct minimum, complete sets of distances necessary to specify the exact structure of the entire molecule in three dimensions from incomplete distance information, and to identify sets of inconsistent distances. The method is illustrated for the flexible structural types present in large ribosomal RNAs: 1.) A five-membered ring; 2.) a chemically bonded chain with its ends in contact (i.e., a hairpin loop); 3.) the spatial orientation of two separate molecules, and; 4.) an RNA helix that can have variation in individual base pairs, giving rise to global deviation from standardized helical forms.
Neutrophils Mediate Parenchymal Tissue Necrosis and Accelerate the Rejection of Complete Major Histocompatibility Complex-Disparate Cardiac Allografts in the Absence of Interferon-γ

A major feature of acute rejection of cardiac allografts is an intense mononuclear cell infiltration accompanied by interferon (IFN)-γ production. In the current study we tested the role of IFN-γ in acute rejection of allografts by comparing the histopathology of rejection in wild-type versus IFN-γ−/− recipients of major histocompatibility complex-mismatched cardiac grafts. Wild-type recipients rejected the allografts at days 8 to 9 after transplant but rejection was accelerated 2 to 3 days in IFN-γ-deficient recipients. During rejection in wild-type recipients, the allografts were heavily infiltrated with CD8+ T cells and other mononuclear cells. In contrast, allografts in IFN-γ-deficient recipients had few T cells but an intense neutrophil infiltration accompanied by extensive graft parenchymal necrosis. No difference in expression levels of neutrophil chemoattractants including Groα/KC, MIP-2, GCP-2, and MIP-1α, was observed in allografts retrieved from wild-type and IFN-γ−/− recipients. Depletion of neutrophils from IFN-γ-deficient recipients delayed rejection until days 8 to 10 after transplant and restored the histopathology of acute allograft rejection to that observed in allografts rejected by wild-type recipients. These results indicate the potent regulatory properties of IFN-γ during acute rejection directed at neutrophil infiltration into allografts and mediating graft tissue necrosis.
Aortic valve closure associated with HeartMate left ventricular device support: technical considerations and long-term results.

Background Aortic valve integrity is crucial for optimal left ventricular assist device (LVAD) support. Pre-existing native aortic insufficiency, aortic valve incompetence acquired during support, as well as previously placed prosthetic aortic valves present unique problems for these patients. Methods We reviewed and analyzed data for 28 patients who underwent left ventricular outflow tract closure associated with HeartMate I ( n =12) and HeartMate II ( n = 16) LVAD insertion or exchange. Indications for valve closure, surgical technique, LVAD function, survival rates and complications were retrospectively analyzed. Survival rates were compared with those of HeartMate LVAD patients ( n = 104) who did not undergo aortic valve closure. Results Indications for closure included native aortic valve insufficiency (10 patients), aortic valve deterioration after prolonged LVAD support (8 patients) and previously placed mechanical (9 patients) or bioprosthetic aortic prostheses (1 patient). There were 2 operative and 5 late deaths (mean 227 days post-operatively). Of the deaths, none were due to aortic valve closure. Actuarial survival was 78% at 1 year and 53% at 3 years, which was statistically better than for our patients with an intact aortic outflow (61% at 1 year, 45% at 3 years; p Conclusion Outflow tract closure in LVAD-supported patients is safe, often necessary and well tolerated.
Competition, gender and the sport experience: an exploration among college athletes

Worldwide, sport and physical activity rates of women generally lag behind those of men. One reason for this could be the way that sport cultures typically frame and value competition. This study provides an examination of the meaning and impact of ‘competition’ on the sport participation experiences of men and women. Using Interpretative Phenomenological Analysis, individual and group interviews were conducted with 76 current and former male and female collegiate athletes from both varsity and club sports regarding the impact of competition on their sport experiences. Results revealed that women and men tended to view and interpret competition differently, which strongly impacted their sport experiences. Sport programming that embraces a balance of cooperation and competition may be valuable for attracting and retaining both male and female participants.
Improving data-flow analysis with path profiles

Data-flow analysis computes its solutions over the paths in a control-flow graph. These paths---whether feasible or infeasible, heavily or rarely executed---contribute equally to a solution. However, programs execute only a small fraction of their potential paths and, moreover, programs' execution time and cost is concentrated in a far smaller subset of hot paths.This paper describes a new approach to analyzing and optimizing programs, which improves the precision of data flow analysis along hot paths. Our technique identifies and duplicates hot paths, creating a hot path graph in which these paths are isolated. After flow analysis, the graph is reduced to eliminate unnecessary duplicates of unprofitable paths. In experiments on SPEC95 benchmarks, path qualification identified 2--112 times more non-local constants (weighted dynamically) than the Wegman-Zadek conditional constant algorithm, which translated into 1--7% more dynamic instructions with constant results.
Spectroscopic Measurement of Solute and Cosolvent Partitioning between Supercritical CO2 and Polymers

Cosolvents exhibit significant effects on the partitioning behavior of dilute solutes between a supercritical CO2 fluid phase and cross-linked siloxane-based polymers. A spectroscopic technique was developed and applied that allows us to measure the partition coefficients of both the cosolvents and solutes between the two phases. The Sanchez−Lacombe lattice fluid equation of state was extended to represent a two-phase, four-component system and was quantitatively successful in representing the volumetric and phase-equilibria properties of such systems. We then apply the model and our data to investigate the magnitudes of stationary-phase effects in supercritical fluid chromatography and explore opportunities to use the model for a priori prediction of separation.
On dependence and delay: Capacity bounds for wireless networks

This paper investigates the impact of noise dependence and signal delay on the capacities of networks. It is shown that statistical dependence between the noise in a network's component channels is helpful for communication. In particular, the capacity region of a network whose component channels exhibit dependent noise is a superset of the capacity region of a network built from the same component channels when the noise in those channels is independent. It is also shown that delay has no impact on capacity. That is, the capacity of a network of memoryless channels is unchanged by the addition of finite delays anywhere in the network. Both results are proven for all possible networks of memoryless point-to-point and multi-terminal channels under multiple multicast connections. All other connection types (e.g., single unicast, multiple unicast, single multicast, and mixed unicast and multicast connections) are special cases of the multiple multicast problem, and are therefore included in the given results. The results also generalize from reliable communication of independent sources to lossy or lossy description of possibly dependent sources (i.e., joint source-channel coding) across the same network.
Determining user privacy preferences by asking the right questions: an automated approach

One fundamental aspect of user privacy is to respect the privacy preferences that users have. A clear prerequisite to doing this is accurately gauging what user's privacy preferences are. Current approaches either offer limited privacy options or have so many choices that users are likely to be overwhelmed. We present a framework for modeling user privacy preferences in terms of a hierarchy of questions which can be asked. We describe two means of dynamically choosing which questions should be asked to efficiently determine what a user's privacy preferences are.
Prominent production of IL-20 by CD68+/CD11c+ Myeloid-derived cells in psoriasis: Gene regulation and cellular effects

We assessed expression of IL-20 and its receptors in psoriasis, given the recent implication of IL-20 in epidermal hyperplasia. Psoriatic lesional (LS) skin consistently expressed more IL-20 mRNA than nonlesional (NL) skin. Immunoreactivity to IL-20 protein was greater in LS tissue and mainly localized to infiltrating CD68 + /CD11c + (myeloid-derived) dermal leukocytes. Because this contrasted with earlier reports of a keratinocyte source, we assessed IL-20 mRNA expression in a variety of cells in vitro , and confirmed a myeloid-derived cellular source (monocytes). Plastic adhesion, activation of β 2 integrins, and incubation with tumor necrosis factor- α stimulated expression in these cells. IL-20 receptor (IL-20R) α and IL-20R β mRNA was decreased in LS versus NL skin, which also contrasted with earlier findings. To investigate the relationship between IL-20 and disease activity, we examined psoriasis patients treated with the CD2-targeted agent alefacept. In therapeutic responders, lesional IL-20 mRNA decreased to NL levels, suggesting that CD2 + leukocytes may proximally regulate IL-20. Finally, to assess IL-20 function, we used microarrays to screen IL-20-treated keratinocytes, which demonstrated upregulation of disease-related and IFN- γ -induced genes. Hence, IL-20 may influence inflammation through IFN-like effects. Together, these data indicate that IL-20 may be an important effector cytokine in psoriasis, and that its inhibition may represent a potential therapeutic target.
Presidential Candidates and State Crime: Views of Some U.S. College Students

This is a preliminary investigation of hawkish public opinion, understood as criminogenic in that it provides political support for state crimes of aggressive militarism. Our critical criminology approach treats public support for, or acceptance of, state aggression as part of criminogenic political culture. Despite growing interest among critical criminologists in broader perspectives on state crime and the politics of culture, there has been no work on this topic. Our survey of 53 criminal justice students at a liberal arts college finds both hawkish (militarist) and dovish (peaceful) beliefs and preferences regarding U.S. policy and the two major 2008 presidential candidates, Obama and McCain. We investigate whether authoritarianism helps explain hawkish opinions, but find little evidence for that expectation. We find evidence of respondent underestimation of the hawkishness of U.S. politics. We also find extensive evidence of dovish policy preferences, such as approval of diplomacy, a major attraction to Obama.
Implications of modern intelligence research for assessing intelligence in the workplace

Abstract Intelligence research has flourished recently with contributions from multiple sub-disciplines of psychology. However, the fields of Human Resources and I/O Psychology have lagged behind these other sub-disciplines in advancing what is known about intelligence and benefiting from modern improvements to both intelligence theory and test design. This is unfortunate as the increasing pace, complexity, and globalization of work demand a more precise and uncontaminated measurement of intelligence that remains effective across multiple contexts. The current paper attempts to fill this knowledge gap by providing an overview of some of the major intelligence theories and test design principles that have the potential to inform the use of intelligence in HR contexts. Advances in both theory and measurement from psychometric, neurocognitive, cross-cultural, and cognitive literatures are reviewed. Test and item design approaches such as reducing cultural content and content not relevant to the measured domain and increasing the use of non-entrenched items are highlighted.
Some asymptotic properties of a progressively censored nonparametric test for multiple regression

Abstract The large sample null distribution of a progressively censored nonparametric test for multiple regression proposed by Majumdar and Sen is computed. Also the asymptotic nonnull distribution for the test based on Savage scores is computed for local alternatives when the underlying distribution is exponential. The power of this test is compared with the power of the corresponding fixed sample tests. The stopping properties are also investigated. A short table of critical values is included.
Recombinant Charmonium in strongly coupled Quark-Gluon Plasma

We update our previous work on a Langevin-with-interaction model for charmonium in heavy-ion collisions by considering the effect owing to recombination. We determine the contribution to J/psi yields from c-barc pairs whose constituent quarks originate from two different hard processes. Like the surviving J/psi states, the recombinant J/psi also undergo both a stochastic interaction, determined by a hydrodynamical simulation of the heavy-ion collision, and an interaction determined by the Q-barQ potentials measured on the lattice for appropriate temperatures. From the results of these simulations, we determine both the direct and the recombinant contribution to the J/psi yields for RHIC conditions and find that, for central collisions, between 30% and 50% of the J/psi yield is caused by recombinant production. We compare our results with other models and look for how the recombinant contribution differs from the surviving contribution in the differential p{sub T} yields. Including the recombinant contribution improves the agreement with the latest analysis of charmonium at RHIC, which shows an absence of anomalous suppression except in the most central collisions.
Contextual inquiry: quantification and use in videotaped analysis

Contextual Inquiry is a method developed by Beyer and Holtzblatt for grounding design in the context of the work being performed. In this paper, we describe our adaptation of the method to analyze videotaped presentations. Our goal was to find improvements for a slide presentation program currently in development, called 'SlideShow Commander.' Contextual Inquiry provided meaningful data on the structures and typical problems found in presentations, on which we based our design ideas. We then further analyzed and quantified the Contextual Inquiry data, beyond what Beyer and Holtzblatt suggest. This new step provided a means to prioritize the design suggestions, as well as a way to defend the potential commercial usefulness of the software. Deciding upon the value and direction of further effort is essential for software development; by using our adapted form of Contextual Inquiry, we were able to make and defend these decisions.
Volvulus of the splenic flexure: report of a case and review of the literature.

This is the first case report of gangrenous colon from volvulus of the splenic flexure. It is also the first reported treatment of splenic flexure volvulus by exteriorization of the splenic flexure as a loop colostomy. Splenic flexure volvulus has been a rare cause of mechanical obstruction, producing 1 per cent of colonic volvuluses. Fourteen detailed case reports of splenic flexure volvulus were reviewed. Patients averaged 53.2 years old. Eight of 14 were women. Previous abdominal surgery, anomalies of fixation, and constipation played important roles in the pathogenesis. Diagnosis was made before surgery in two-thirds of the patients. Treatment varied. One patient died without treatment. In two, the volvulus reduced spontaneously. Eleven required emergency surgery. Three underwent operative detorsion, one exteriorization of the splenic flexure as a loop colostomy (the present report), and six partial colectomy. All treated patients survived without recurrence of volvulus. Thus, there was only one death in 14 cases, a seven per cent mortality rate. This low mortality rate was attributed to the rarity of gangrenous colon from splenic flexure volvulus.
A robotic sample changer for a radiochemistry laboratory

A Microbot Alpha robot has been interfaced to a Nuclear Data Model 680 multichannel analyzer (MCA) and computer to allow unattended accumulation and storage of gamma-ray spectra. Software was written in DEC RT-11 system language to control the robot, MCA and dual floppy disk system from a DEC LSI-11 microcomputer. Typically, 8 spectra are accomulated for 3 hours each, providing 24 hours of unattended operation for one detector or 12 hours for two detectors. The system has proven to be highly reliable and has eliminated the need for operator intervention after working hours.
Quantitative Images of Elastic Modulus Using Tissue Dynamics in the Region of Impulsive Acoustic Radiation Force Excitation

Focused, impulsive, acoustic radiation force excitations can generate shear waves with microns of displacement in tissue. The speed of shear wave propagation is directly related to the tissue’s shear modulus, which can be correlated with tissue pathology to diagnose disease and to follow disease progression. Shear wave speed reconstruction has conventionally been measured over spatial domains that are spatially-offset from the region of excitation (ROE). While these methods are very robust in clinical studies characterizing large, homogeneous organs, their spatial resolution can be limited when generating quantitative images of shear elasticity. The ROETTP algorithm measures time-to-peak (TTP) displacements along the axis-of-symmetry in the ROE of an impulsive acoustic radiation force excitation. These TTP displacements are inversely proportional to shear stiffness and are dependent on the excitation-beam geometry. Lookup tables (LUTs) specific to an excitation/displacement tracking transducer configuration were generated from simulated data, and shear stiffnesses were estimated from experimental data as a function of depth using the LUTs. Quantitative ROETTP shear elasticity images of spherical inclusions in a calibrated tissue-mimicking phantom have been generated. Shear wave reflections and interference can lead to an underestimation of the absolute reconstructed shear modulus (20–25%), but the ratio of absolute shear stiffnesses is well-preserved (3.3 vs. 3.5).Copyright © 2009 by ASME
Sol-gel coating of YBa2Cu3O7-x with TiO2 for enhanced anisotropic grain growth

This investigation focused on the effects of TiO 2 additions (2.5–5 mol%) incorporated via sol-gel coating of powders on sintering behavior, microstructure development, electrical resistivity, and magnetic susceptibility of YBa 2 Cu 3 O 7−x . Specimens were sintered at ≤ 960 °C for 6 h in all cases. TEM analysis indicated the sol-gel coating to be uniformly distributed around each particle and of thickness ∼ 20 to 40 nm. The addition of TiO 2 was seen to reduce the sintering temperature by up to ∼ 200 °C, indicating the formation of a liquidus phase below that normally reported for YBa 2 Cu 3 O 7-x . Grain growth and grain anisotropy behavior were influenced by TiO 2 addition. A maximum in density, grain size, and anisotropy was achieved with 2.5 mol% addition sintered at 930 °C. TiO 2 addition was shown to result in the formation of greater amounts of secondary phases such as Y 2 BaCuO 2 , and BaCuO 2 , particularly at higher TiO 2 levels and sintering temperatures. The use of TiO 2 additions also altered the magnetic susceptibility with the optimum response occurring for samples with 2.5 mol% TiO 2 addition when sintered at 930 °C.
The use of quantitative traits in the study of human population structure

Studies of human population structure and history have tended to use demographic and/or serological data for analysis. This paper reviews the methods and studies that incorporate quantitative traits (usually polygenic traits) in such analyses. Methods of assessing the degree and pattern of among-group variation are discussed, and are characterized as being model-free or model-bound. Model-free methods deal with the measure of overall populational differentiation and with comparative methods for describing the pattern of differentiation. Model-bound methods are used for direct incorporation into theoretical models of population structure in order to estimate genetic parameters, such as those in admixture and isolation by distance models. To date, studies have indicated that quantitative traits may often be used successfully in studies of human population structure, and show effects of microevolutionary forces on quantitative variation among populations.
X-ray diffuse scattering study of local distortions in Fe 1 + x Te induced by excess Fe

We report x-ray diffuse scattering studies of the iron chalcogenide Fe{sub 1+x}Te as a function of doping and temperature for x = 0.03, 0.08, and 0.12. In all cases, remarkably strong, characteristic diffuse scattering is observed. This scattering extends throughout the Brillouin zone and exhibits a nonmonotonic decay away from the fundamental Bragg peaks, with a peaklike structure at a reduced q {approx} (0.3,0,0.6). We interpret this scattering as Huang diffuse scattering resulting from distortions induced by the interaction between the excess Fe and the FeTe layers. The form of the scattering indicates that this interaction is strong and extends a number of unit cells away from the interstitial Fe site. Further, the diffuse scattering shows a sudden decrease on cooling through the structural and magnetic phase transition, reflecting the first-order change of the electronic structure of FeTe.
Membrane processing of xanthophylls in ethanol extracts of corn.

Abstract Xanthophylls such as lutein and zeaxanthin are naturally occurring yellow–orange oxygenated pigments of the carotenoid family. They can be extracted from plant materials with organic solvents such as ethanol or hexane. The objective of this research was to develop methods for concentrating and purifying xanthophylls extracted from corn using membrane technology. Ultrafiltration (UF) was used to separate ethanol-soluble protein (zein) and other large solutes from the extract. The xanthophyll-containing stream was concentrated and separated from the solvent using nanofiltration (NF). Ethanol can be recycled back to the process. This study focused on screening commercially available and prototype polymeric UF and NF membranes for the flux and rejection of model lutein solutions and aqueous ethanol extracts of whole ground corn.
Nucleotide-sequence differences among ribosomal ribonucleic acid fractions and soluble ribonucleic acid from various bacterial species

Abstract Bacterial RNA fractions with identical base compositions have been compared by digesting the RNA with pancreatic RNAase (EC 2.7.7.16) and determining the relative frequency of nucleotide fragments. 1. 1. There were no detectable differences among several strains of Escherichia coli nor for the same strain grown under a variety of conditions. 2. 2. The 70-S ribosomal RNA's from bacteria with widely varying guanine-cytosine contents of their DNA were compared. There were no detectable differences among bacteria closely related to E. coli. Only species with very high or low guanine-cytosine contents showed considerable differences in their RNA from each other and from E. coli. 3. 3. The 50-S and 30-S RNA's of these species differ from each other and from the corresponding fractions of E. coli. 4. 4. Nucleotide mapping of s-RNA's also showed no detectable differences among species closely related to E. coli but considerable differences for bacteria with high or low guanine-cytosine content of their DNA. The implications of these results in terms of the synthesis and function of the various RNA fractions are discussed.
Estimating local strain due to comminution in experimental cataclastic textures

Abstract Cataclastic textures were produced by deforming porous quartz sandstone samples at room temperature, 15–200 MPa confining pressure, and 13–57% strain ( γ ∼2–20). Particle size distribution (PSD) and fractal dimension ( D ) values were measured on different digital images of each sample. Over the range of applied axial strain the detectable effects of comminution (particle-size reduction through fracture) on PSD were limited to the population of particles ≥7 μm. Textural variable ψ , named comminution intensity, is defined in terms of total sectional area of particle population greater than a critical size S c . For the Massillon sandstone the S c is close to four times the suggested value for quartz grinding limit. The comminution intensity vs. axial strain data due to the entire range of applied pressure and strain fits a power function of the form ϵ 11 = ψ m , with 0.25≤ m ≤0.5. The local strain due to constrained comminution is then predictable by model function ϵ L = ψ n , where n =1/ m , with empirical n =2.97 for the studied sandstone. The model predicts relatively monotonous textures for very small and very large strains, while the highest variety of particle size occurs at between 2 and 13% strain. Applications of the method include millimeter to meter scale mapping of the relative degree of comminution in natural fault gouge and the local strain values in experimental samples.
On-line Homework/Quiz/Exam applet: Freely available Java software for evaluating performance on line

The Homework/Quiz/Exam applet is a freely available Java program that can be used to evaluate student performance on line for any content authored by a teacher. It has database connectivity so that student scores are automatically recorded. It allows several different types of questions. Each question can be linked to images and detailed story problems. Three levels of feedback are provided to student responses. It allows teachers to randomize the sequence of questions and to randomize which of several options is the correct answer in multiple-choice questions. The creation and editing of questions involves menu selections, buttonpresses, and the typing of content; no programming knowledge is required. The code is open source in order to encourage modifications that will meet individual pedagogical needs.
10 kV, 120 a SiC MOSFET modules for a power electronics building block (PEBB)

10 kV, 120 A all-SiC half-bridge modules were tested and simulated for use in a 4 kV, 100 A power electronics building block (PEBB), which are standard, multifunctional units that can replace specialized devices in order to simplify the design and reduce the cost of power electronic systems. This PEBB design consists of four 10 kV SiC MOSFET modules in an H-bridge configuration. Each switch in the module contains twelve parallel 10 kV SiC DMOSFETs, and six parallel 10 kV SiC junction barrier Schottky (JBS) diodes. Double-pulse tests (DPTs) were conducted on the 10 kV modules up to 4.7 kV and 100 A in order to evaluate their hard switching capabilities. The DPT results revealed fast switching, with rise and fall times of 170 ns and 460 ns, respectively, and minimal ringing and overshoot. A Saber model of the module was then compared to the experimental results, which showed sufficient agreement with the testing waveforms. This model was then used to simulate the PEBB operation.
Combining Non-Stably Infinite Theories

The Nelson-Oppen combination method combines decision procedures for flrst-order theories over disjoint signatures into a single decision procedure for the union theory. To be correct, the method requires that the component theories be stably inflnite. This restriction makes the method inapplicable to many interesting theories such as, for instance, theories having only flnite models. In this paper we provide a new combination method that can combine any theory that is not stably inflnite with another theory, provided that the latter is what we call a shiny theory. Examples of shiny theories include the theory of equality, the theory of partial orders, and the theory of total orders. An interesting consequence of our results is that any decision procedure for the satisflability of quantifler-free §-formulae in a §-theory T can always be extended to accept inputs over an arbitrary signature ›¶ §.
Direction finding with circular arrays via phase mode excitation and Root-MUSIC

The authors develop an algorithm for estimating the azimuth angles of narrowband signals incident upon a uniform circular array of identical antennas. The method operates in beamspace and relies on the phase mode excitation technique to synthesize sinc type beam-patterns in the array plane (elevation=90 degrees ). The sinc structure allows the use of a root version of the MUSIC algorithm to perform the azimuthal search at each elevation angle under consideration. Besides the ability to use Root-MUSIC, the algorithm provides computational savings in that it requires only a single real-valued eigenvalue decomposition. This follows since the far-field patterns synthesized are entirely real-valued. >
Teaching Leadership to First-Year Students in a Learning Community.

This paper discusses a model for teaching leadership to first-year students as part of a learning community. It outlines the purpose and structure of the course and presents ideas for how different disciplines could be combined with leadership in learning communities. Teaching leadership to first-year students as part of a learning community instead of a stand-alone course has two distinct advantages. First, when leadership is taught at the freshman level, the early introduction of the topic allows for the possibility of repetition and reinforcements of the concepts, both of which are essential to learning. Second, by teaching leadership in a learning community, instructors and students are able to apply and integrate the concepts of leadership with other areas, thereby increasing learning and retention.
Slow Pathway Ablation for Atrioventricular Nodal Reentry Using a Right Internal Jugular Vein Approach: A Case Series

Methods: This case series describes three patients with an IVC filter who underwent successful ablation of the slow pathway for typical atrioventricular (AV) nodal reentrant tachycardia using a superior vena cava (SVC) approach via the right internal jugular (IJ) vein. Two separate introducer sheaths were placed into the IJ vein using separate punctures. This permitted placement of a standard deflectable ablation catheter and an additional catheter in the right atrium to monitor for ventriculoatrial conduction during the junctional rhythm associated with ablation of the slow AV nodal pathway. Results: Catheter ablation was successful in each patient. The number of radiofrequency current applications was 7, 17, and 27. There were no procedural complications and no patient had recurrent tachycardia during follow-up. Conclusions: Catheter ablation of the slow AV nodal pathway can be performed successfully and safely in patients with inferior venous barriers to the right heart using an SVC approach via the right IJ vein. (PACE 2006; 29:59‐62)
Self-reproducing learning, data mining and intelligent predictive systems

Self-reproducing learning mechanism is a type of learning technique which was developed from our intelligent predictive systems. It is very useful to be applied to our Lotto Predictive System to increase the performance of prediction. Self-reproducing learning technique is part of our knowledge discovery data mining tools on Lotto predictive system. Lotto predictive system is also based on human super nature beliefs as part of its knowledge. A generalized "pick n out of m" Lotto problem drawn daily for any fixed integer n and m where 8n/spl ges/m/spl ges/17 has been studied and used to describe self-reproducing learning systems and intelligent predictive systems.
Synthesis, analysis, and pitch modification of the breathy vowel

Breathiness is an aspect of voice quality that is difficult to analyze and synthesize, especially since its periodic and noise components are typically overlapping in frequency. The decomposition and manipulation of these two components is of importance in a variety of speech application areas such as text-to-speech synthesis, speech encoding, and clinical assessment of disordered voices. This paper first investigates the perceptual relevance of a speech production model that assumes the speech noise component is modulated by the glottal airflow waveform. After verifying the importance of noise modulation in breathy vowels, we use the modulation model to address the particular problem of pitch modification of this signal class. Using a decomposition method referred to as pitch-scaled harmonic filtering to extract the additive noise component, we introduce a pitch modification algorithm that explicitly modifies the modulation characteristic of this noise component. The approach applies envelope shaping to the noise source that is derived from the inverse-filtered noise component. Modification examples using synthetic and real breathy vowels indicate promising performance with spectrally-overlapping periodic and noise components.
Preload-adjusted maximal power: a novel index of left ventricular contractility in atrial fibrillation.

Background: Left ventricular contractility in atrial fibrillation is known to change in a beat to beat fashion, but there is no gold standard for contractility indices in atrial fibrillation, especially those measured non-invasively. Objective: To determine whether the non-invasive index of contractility “preload-adjusted PWRmax” (maximal ventricular power divided by the square of end diastolic volume) can accurately measure left ventricular contractility in a beat to beat fashion in atrial fibrillation. Methods: Atrial fibrillation was induced experimentally using 60 Hz stimulation of the atrium and maintained in 12 sheep; four received diltiazem, four digoxin, and four no drugs (control). Aortic flow, left ventricular volume, and left ventricular pressure were monitored simultaneously. Preload-adjusted PWRmax, the slope of the end systolic pressure–volume relation (Emax), and the maximum rate of change of left ventricular pressure (dP/dtmax) were calculated in a beat to beat fashion. Results: Preload-adjusted PWRmax correlated linearly with load independent Emax (p < 0.0001) and curvilinearly with load dependent dP/dtmax (p < 0.0001), which suggested the load independence of preload-adjusted PWRmax. After five minutes of diltiazem administration, preload-adjusted PWRmax, dP/dtmax, and Emax fell significantly (p < 0.0001) to 62%, 64%, and 61% of baseline, respectively. Changes were not significant after five minutes of digoxin (103%, 98%, and 102%) or in controls (97%, 96%, and 95%). Conclusions: Preload-adjusted PWRmax correlates linearly with Emax and is a useful measure of contractility even in atrial fibrillation. Non-invasive application of this method, in combination with echocardiography and tonometry, may yield important information for optimising the treatment of patients with atrial fibrillation.
Generalized longest queue first: an adaptive scheduling discipline for ATM networks

We propose a generalized longest queue first (GLQF) service discipline for ATM networks. We classify sources so that sources in one class have the same cell loss probability requirement. Assume that there are N classes of traffic. Under this discipline, buffer i is assigned a positive number w/sub i/ for the weight of buffer i. The scheduler transmits a cell from the buffer that has the maximal weighted queue length. The advantage of this discipline is that it can adapt to temporary overload quickly. We approximate the queue length distribution by decomposing the system into N single server queues with probabilistic service discipline. Our method is an iterative one, which we prove to be convergent by using stochastic dominance arguments and the coupling technique. For high utilization, we present a heavy traffic limit theorem.
Vancomycin-Resistant Enterococci Colonization Among Dialysis Patients: A Meta-analysis of Prevalence, Risk Factors, and Significance

Background Vancomycin-resistant enterococci (VRE) have become important nosocomial pathogens causing outbreaks worldwide. Patients undergoing dialysis represent a vulnerable population due to their comorbid conditions, frequent use of antibacterial agents, and frequent contact with health care settings. Study Design Systematic review and meta-analysis of cross-sectional studies of screening for VRE colonization. Setting & Population Patients receiving long-term dialysis treatment. Selection Criteria for Studies We performed a systematic literature search of PubMed and EMBASE databases to identify studies performing screening for VRE colonization among dialysis patients. Predictor Region, recent use of vancomycin or other antibiotics, previous hospitalization. Outcomes (1) VRE colonization and (2) rate of VRE infection among colonized and noncolonized individuals. Relative effects were expressed as ORs and 95% CIs. Results We identified 23 studies that fulfilled the inclusion criteria and provided data for 4,842 dialysis patients from 100 dialysis centers. The pooled prevalence of VRE colonization was 6.2% (95% CI, 2.8%-10.8%), with significant variability between centers. The corresponding number for North American centers was 5.2% (95% CI, 2.8%-8.2%). Recent use of any antibiotic (OR, 3.62; 95% CI, 1.22-10.75), particularly vancomycin (OR, 5.15; 95% CI, 1.56-17.02), but also use of antibiotics other than vancomycin (OR, 2.92; 95% CI, 0.99-8.55) and recent hospitalization (OR, 4.55; 95% CI, 1.93-10.74) significantly increased the possibility of a VRE-positive surveillance culture. Colonized patients had a significantly higher risk of VRE infection (OR, 21.62; 95% CI, 5.33-87.69) than their noncolonized counterparts. Limitations In 19 of 23 studies, a low percentage of dialysis patients ( Conclusions VRE colonization is prevalent in dialysis centers. Previous antibiotic use, in particular vancomycin, and recent hospitalization are important predicting factors of colonization, whereas the risk of VRE infection is significantly higher for colonized patients.
The influence of abuse victimization on attendance and involvement in mutual-help groups among dually diagnosed male veterans

Although abuse victimization and dual diagnosis are associated with poor functioning across numerous domains, their impact on attendance and involvement in mutual-help groups (MHGs) is not well understood. This study examined the impact of physical or sexual abuse victimization on MHG attendance and involvement and the influence of abuse on the association between MHG involvement and outcomes of abstinence and psychiatric health. Participants were 217 dually diagnosed men assessed at intake into mental health treatment and 6 months later. Compared with nonabused patients, sexually abused patients exhibited more substance use, psychiatric, and social problems at baseline and attended and were involved with MHGs more than nonabused patients at follow-up. Moreover, MHG involvement was most predictive of abstinence for sexually abused patients, as compared with nonabused and physically abused patients. Although dually diagnosed patients with abuse histories demonstrate more severe initial problems, they are likely to utilize MHGs, which may benefit efforts to achieve abstinence.
Large System Performance of Downlink OFDMA with Limited Feedback

We consider allocation of sub-channels to users in a downlink OFDMA system. Each user feeds back one bit per sub-channel, which indicates whether or not the gain exceeds a threshold. Users are assigned priority weights, and the thresholds are selected to maximize the weighted sum capacity. We analyze the behavior of the optimal thresholds and growth in capacity, assuming i.i.d. Rayleigh fading sub-channels, in the large system limit in which users K and sub-channels tend to infinity with fixed ratio. If all users have the same priority weight, then the optimized threshold increases as log K minus a second-order term, which is asymptotically bounded between log log K and log log log K. Furthermore, the sum capacity per sub-channel increases as log log K plus a second-order term, which decreases to a constant as log log K/ log K. We then consider two classes of users, each assigned a different weight, and show that the capacity of the low priority group tends to zero. Finally, we solve for the optimal thresholds given a fairness constraint on the ratio between the rates of different classes
Toward a Theory of Restaurant Décor: An Empirical Examination of Italian Restaurants in Manhattan:

Restaurants have seldom been the subject of theory-driven empirical research. Moreover, extant literature has generally focused on food and service quality issues, ignoring decor as a key influenci...
Democracy in Latin America: Political Change in Comparative Perspective

Democracy in Latin America: Political Change in Comparative Perspective. By Peter H. Smith. New York: Oxford University Press, 2005. 380p. 28.95 paper. Peter Smith set out to write a textbook and ended up compiling an original database of Latin American democracy from 1900 to 2000. Analyzing a century of democratic change, Smith has written an impressive book that is accessible to undergraduates, a great literature review for graduate students, instructive for policymakers, and a significant contribution to scholarly understanding of a complex phenomenon. All of this is done with a lively and jargon-free writing style.
Corporate Governance and Bank Performance: A Joint Analysis of the Static, Selection, and Dynamic Effects of Domestic, Foreign, and State Ownership

We jointly analyze the static, selection, and dynamic effects of domestic, foreign, and state ownership on bank performance. We argue that it is important to include indicators of all the relevant governance effects in the same model. "Nonrobustness" checks (which purposely exclude some indicators) support this argument. Using data from Argentina in the 1990s, our strongest and most robust results concern state ownership. State-owned banks have poor long-term performance (static effect), those undergoing privatization had particularly poor performance beforehand (selection effect), and these banks dramatically improved following privatization (dynamic effect). However, much of the measured improvement is likely due to placing nonperforming loans into residual entities, leaving "good" privatized banks.
Crest factor reduction through in-band and out-of-band distortion optimization

A new crest factor reduction (CFR) technique is presented to reduce the peak to average ratio (PAR) of a wide-band code division multiple access (WCDMA) signal. Simple CFR techniques hard limit the desired signal to reduce the amplitude peaks and filtering is used to remove the out-of-band distortion. Here the trade-off between allowing out-of-band distortion and the error vector magnitude (EVM) is investigated for different levels of PAR reduction. It is demonstrated that there is an optimum clipping level for a desired PAR when trading off adjacent channel power ratio (ACPR) and EVM.