cssi/SciSciGPT-SciSciNet huggingface dataset:
Impact of concomitant mitral valve repair for severe mitral regurgitation at the time of continuous-flow left ventricular assist device insertion

Objectives Mitral regurgitation (MR) is common in patients with end-stage heart failure. We assessed the effect of performing concomitant mitral valve repair during continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with severe preoperative MR. Methods We performed a single-centre, retrospective review of all patients who underwent CF-LVAD implantation between December 1999 and December 2013 (n = 469). Patients with severe preoperative MR (n = 78) were identified and then stratified according to whether they underwent concomitant valve repair. Univariate and survival analyses were performed, and multivariable regression was used to determine predictors of survival. Results Of the 78 patients with severe MR, 21 underwent valve repair at the time of CF-LVAD implantation (repair group) and 57 did not (non-repair group). A comparison of the 2 groups showed significant differences between groups: INTERMACS I 16.985 vs 9.52%, (P = 0.039), cardiopulmonary bypass time 82.09 vs 109.4 min (P = 0.0042) and the use of HeartMate II 63.16 vs 100% (P = 0.001). Survival analysis suggested trends towards improved survival and a lower incidence of heart failure-related readmissions in the repair group. Multivariable regression analysis showed no significant independent predictors of survival (mitral valve repair: odds ratio 0.4, 95% confidence interval 0.8-1.5; P = 0.2). Conclusions Despite the lack of statistical significance, trends towards improved survival and a lower incidence of heart failure events suggest that mitral valve repair may be beneficial in patients undergoing CF-LVAD implantation. Given the known relationship between severe MR and mortality, further study is encouraged to confirm the value of mitral valve repair in these patients.
Outcomes of organ transplants when the donor is a prior recipient.

Organ shortage continues to challenge the field of transplantation. One potential group of donors are those who have been transplant recipients themselves, or Organ Donor After Transplant (ODAT). We conducted a retrospective cohort study to describe ODAT donors and to compare outcomes of ODAT grafts versus conventional grafts. From 10/1/87 to 6/30/15, 517 former recipients successfully donated 803 organs for transplant. Former kidney recipients generally survived a median of approximately four years before becoming an ODAT donor whereas liver, lung, and heart recipients generally survived less than a month prior to donation. In the period 1/1/05 to 12/31/14, liver grafts from ODAT donors had a significantly higher risk of graft failure compared to non-ODAT liver transplants (p = 0.008). Kidney grafts donated by ODAT donors whose initial transplant occurred >1 year prior were associated with significantly increased graft failure (p = 0.012). Despite increased risk of graft failure amongst certain ODAT grafts, five year survival was still high. ODAT donors should be considered another form of expanded criteria donor under these circumstances. This article is protected by copyright. All rights reserved.
Growth and Foliar Nutrient Concentrations of Crape Myrtle in Response to Disparate Climate and Fertilizer Placement in Large Nursery Containers

Abstract A study was replicated in different climates [central Arizona (arid, Sonoran desert) and southwestern Georgia (humid, temperate)] to evaluate effects of controlled-release fertilizer placement in a bark-based container substrate on growth and foliar nutrient concentrations of Lagerstroemia indica L. × L. fauriei Koehne ‘Muskogee’ in large (#7) containers. Plants in Arizona were smaller with higher shoot-to-root ratios and higher levels of N, K, P, Fe, and Cu and lower levels ofCa and Zn in foliage compared with plants in Georgia. Differences in meteorological factors such as higher maximum and minimum temperatures and solar radiation, lower rainfall, and higher container root-zone temperatures, leachate electrical conductivity and nitrate concentrations were coincident with the smaller size and higher foliar nutrient concentration of Arizona plants. Fertilizer placed at the north exposure of container substrate increased plant size in Arizona. However, compared with growth of plants in Georgia, f...
Optimizing the spatio-temporal deployment of battery electric bus system

Abstract Environmental concerns due to fossil fuel consumption and emissions drive transportation industry to shift towards low-impact and sustainable energy sources. Public transit system, as an integral part of multimodal transportation ecosystem, has been supporting such shift by exploring the adoption of electric vehicles. In recent years, the advancement in Battery Electric Buses (BEBs) and their supporting infrastructure technology made them a viable replacement for diesel and Compressed Natural Gas (CNG) buses. Yet, it remains a challenge on how to optimally deploy the BEB system due to its unique spatio-temporal characteristics. To fill this gap, this research introduces a spatio-temporal optimization model to identify the optimal deployment strategies for BEB system. The identified spatio-temporal deployment of BEB system can minimize the cost associated with vehicle procurement and charging station allocation, while satisfying transit operation constraints such as maintaining existing bus operation routes and schedules. The proposed method is implemented onto the transit network operated by the Utah Transit Authority (UTA) to showcase its effectiveness. As many transit agencies are testing electric buses and considering the integration of electric buses into future fleet, this research will help transit agencies make informed decisions regarding strategic planning and design of BEB systems.
Dimensioning wireless use cases in Industrial Internet of Things

Industrial wireless is increasingly developing to enhance data dissemination in the Industrial Internet of Things (IIoT) for leveraging the visibility, control, and safety in industrial environments. In this paper we propose a generic framework that enumerates physical and cyber factors in an IIoT use case that may impact the performance of wireless transmissions and challenge the design work. These factors are discussed in a conceptually tiered structure using domain knowledge from operational technology (OT) applications, data services, and information technology (IT) infrastructures. The correlations between intra- and inter-domain factors are also discussed in search of efficient wireless design solutions. Given the diversity and variety of IIoT practices, such a framework that identifies general and specific wireless requirements in individual use cases would be of high practical value to industrial wireless design and implementation.
Precedential Cascades: A Critical Appraisal

A number of legal scholars have recently posited a "group herding" account of legal institutions and precedent. Their arguments draw heavily from the emergent literature on information cascades -- a set of theories that attempts to explain certain pathologies of group behavior. Explicitly, cascade theory demonstrates how rational individuals, when making ostensibly individual decisions, may ignore their own private inclinations, choosing to emulate others instead. When aggregated, such behavior can lead to significant errors of judgment on behalf of the entire group, particularly if exacerbated by other cognitive effects. If legal precedent is a species of cascade, then the consequences for legal theory are profound. Indeed, not only would such a theory call into question the wisdom of celebrated "watershed" cases from the last century, but it would also severely compromise virtually any positive account of law that conceives of precedent as a central mechanism for judicial learning. This article critically analyzes the viability of a cascade theory of precedent, asking whether such phenomena are (a) possible, (b) plausible, and (c) empirically verifiable. Although I find that a precedential cascade is certainly possible as a matter of theory, the necessary conditions for its occurrence are either extremely rare or easily avoidable. Moreover, even the more modest task of diagnosing when precedential cascades occur may be unavailing: for the outward symptoms of a cascade are essentially indistinguishable from those of more plausible (and less troubling) behavioral hypotheses.
Absence of ferric enterobactin receptor modification activity in mutants of Escherichiacoli K-12 lacking protein a

The modification activity for the ferric enterobactin receptor in the Triton X-100 solubilized outer membrane of Escherichiacoli K-12 was adsorbed to a column of p-aminobenzamidine-//-sepharose and eluted with free benzamidine. Recombination of the dialyzed eluate with the filtrate from the column reinstituted conversion of the receptor from 81K to 81K∗, the latter exhibiting an apparent molecular weight of 74,000 daltons in sodium dodecyl sulfate polyacrylamide gel analysis. The eluate from the p-aminobenzamidine column was shown to contain a component, coincident on gels with both protein and modification activity, which by mutational and other analyses appears to be identical with protein a of the outer membrane.
Explaining dissensus on the Bulgarian constitutional court

Using original data, this study investigates the determinants of dissent on the Bulgarian Constitutional Court, which occurs frequently and is high by comparative standards. This analysis contribut...
Language Hegemonies and their Discontents: History, Theory, Bilingualism, and Funds of Knowledge

This article reviews hegemonic impositions of language and culture over the history of the Southwest North American Region, beginning with Spanish imperial attempts to erase the existing linguistic and cultural practices of Indigenous communities. It goes on to consider the educational processes by which English language and American culture were imposed on Mexican American children and communities following the American Mexican War. Along with hegemonic attempts to subdue and dominate populations, the article also explores the myriad ways subjugated populations have expressed their discontent, from violent revolt to the creation of alternative educational programs. With reference to the latter, given the well-attested benefits of bilingualism, it is argued that one way to capitalize on the cultural and linguistic capacities of transborder populations is to integrate dual-language education and a funds of knowledge approach. Engagement in Mexican-origin children’s social networks will help educators to counter the process of cultural erasure and to ensure that bilingual programs benefit language-minority students, and not just middle-class, English-dominant students. Without support for Mexican-origin and other Latino/a students to emerge fully as complex cultural beings, we will continue to perpetuate a situation of linguistic and cultural hegemony where populations are restricted from their full human potential.
Very low food security status is related to lower cooking self-efficacy and less frequent food preparation behaviors among college students.

ABSTRACT Objective Investigate the relationships between food security status and cooking self-efficacy and food preparation behaviors among college students. Methods Students living off campus while attending the University of Alabama completed an online survey between February and April 2016. Food security status was assessed using the Adult Food Security Survey Module. Cooking self-efficacy and food preparation behaviors were assessed using validated questionnaires. Multiple regression analysis was used to test for significant differences in cooking self-efficacy and food preparation scores by food security status. Results Among respondents (n = 368), 38.3% were food insecure. Very low food secure students had significantly lower cooking self-efficacy scores and food preparation scores than food secure students (P = .001). Conclusions and Implications Preparing meals at home is less common for very low food secure students, and these students demonstrate less confidence in cooking ability. Further study of food-related decisions and trade-offs under resource constraints are needed.
Reliability of fitness trackers at different prices for measuring steps and heart rate: a pilot study

The purpose of this pilot study was to assess the accuracy of steps and heart rate measurement of wrist fitness trackers at different prices. Four healthy college students voluntarily tested three wrist fitness bands and a sports watch (Xiaomi Mi Band, Fitbit Charge HRm, Fitbit Surge, and sports watch Polar M400). Subjects performed two sets of 10 series of 100 steps wearing the fitness trackers on an indoor track in two situations: walking and jogging. In the walking situation, the subjects wore a winter coat and gloves. The variables measured were the number of steps, the heart rate, and the level of error. The steps error percentage for all four devices was lower than 8%. The Fitbit Surge registered significantly more steps in the walking situation (p < 0.001). No significant differences were found in the steps measurements in the jogging situation (p = 0.138). In the jogging situation, significantly lower values in the heart rate measurements for the Xiaomi Mi Band, Fitbit Charger HR, and Fitbit Surge were found (p < 0.001). The results showed that the wearable fitness trackers were relatively accurate for tracking steps (on average, there was a level of error of 2–6%). The assessment of the steps was more accurate in the jogging situation (higher and faster arm swing) than in the walking situation, which involved wearing coats and gloves. The results showed that the wearable fitness trackers that were tested underestimate the heart rate with a level of error of approximately 6–11%. The step error was lower in the walking situation (less mobility of the devices). The price of the devices that were tested did not affect the accuracy of the steps and heart rate assessment. Further studies with a larger sample and more type of devices are needed to confirm these results.
Uninvited citizens: violence, spatiality and urban ruination in postwar and postsocialist Bosnia and Herzegovina

In this article I analyze the lived, violent effects of post war and postsocialist transformations through the prism of one urban ruin in Bihac, a city located on the northwestern edge of Bosnia an...
If we build it, will they come? And will they stay? Commentary on Holmes et al. “Examining patterns of dose response for clients who do and do not complete Cognitive Processing Therapy”

Although evidence-based practice is becoming more widely accepted, the issue of patient preference has been relatively ignored. As noted by Holmes and colleagues (2019), when delivered in a community setting, Cognitive Processing Therapy (CPT) can have a relatively high dropout rate (42 % in the Holmes et al., 2019). In this commentary, issues about the conceptualization of treatment dropout as one index of patient preference are discussed. Dropout can be conceptualized as a potential reflection of poor fit between the patient and a specific empirically-supported treatment. Consideration of ways in which an empirically-supported treatment can be personalized, while remaining true to its underlying principles, are discussed using CPT as an example.
Topology-driven analysis of protein-protein interaction networks detects functional genetic modules regulating reproductive capacity

Understanding the genetic regulation of organ structure is a fundamental problem in developmental biology. Here, we use egg-producing structures of insect ovaries, called ovarioles, to deduce systems-level gene regulatory relationships from quantitative functional genetic analysis. We previously showed that Hippo signalling, a conserved regulator of animal organ size, regulates ovariole number in Drosophila melanogaster. To comprehensively determine how Hippo signalling interacts with other pathways in this regulation, we screened all identified signalling pathway genes, and identified Hpo-dependent and Hpo-independent signalling requirements. Network analysis of known protein-protein interactions among screen results identified independent gene regulatory modules regulating one or both of ovariole number and egg laying. These modules predict involvement of previously uncharacterised genes with higher accuracy than the original candidate screen. This shows that network analysis combining functional genetic and large-scale interaction data can predict function of novel genes regulating development.
Strengthening China's Public Health Response System: From SARS to COVID-19.

Today, the world is experiencing a pandemic caused by a novel coronavirus. COVID-19 is the third disease from a coronavirus to cause a global outbreak, after severe acute respiratory syndrome (SARS...
Backbone Interactions Between Transcriptional Activator ExsA and Anti-Activator ExsD Facilitate Regulation of the Type III Secretion System in Pseudomonas aeruginosa

The type III secretion system (T3SS) is a pivotal virulence mechanism of many Gram-negative bacteria. During infection, the syringe-like T3SS injects cytotoxic proteins directly into the eukaryotic host cell cytoplasm. In Pseudomonas aeruginosa, expression of the T3SS is regulated by a signaling cascade involving the proteins ExsA, ExsC, ExsD, and ExsE. The AraC-type transcription factor ExsA activates transcription of all T3SS-associated genes. Prior to host cell contact, ExsA is inhibited through direct binding of the anti-activator protein ExsD. Host cell contact triggers secretion of ExsE and sequestration of ExsD by ExsC to cause the release of ExsA. ExsA does not bind ExsD through the canonical ligand binding pocket of AraC-type proteins. Using site-directed mutagenesis and a specific in vitro transcription assay, we have now discovered that backbone interactions between the amino terminus of ExsD and the ExsA beta barrel constitute a pivotal part of the ExsD-ExsA interface. Follow-up bacterial two-hybrid experiments suggest additional contacts create an even larger protein-protein interface. The discovered role of the amino terminus of ExsD in ExsA binding explains how ExsC might relieve the ExsD-mediated inhibition of T3SS gene expression, because the same region of ExsD interacts with ExsC following host cell contact.
Effects of Intermittent Ozone Treatment on Postharvest Quality and Storage Life of Pomegranate

The effects of intermittent ozone treatment on the storage quality and life of pomegranate were investigated. Fruit were exposed to 0.5 ppm gaseous ozone for 30 minutes initially and during cold st...
Berezin integral as a limit of Riemann sum

Berezin integration of functions of anticommuting Grassmann variables is usually seen as a formal operation, sometimes even defined via differentiation. Using the formalism of geometric algebra and geometric calculus in which the Grassmann numbers are endowed with a second associative product coming from a Clifford algebra structure, we show how Berezin integrals can be realized in the high dimensional limit as integrals in the sense of geometric calculus. We then show how the concepts of spinors and superspace transform into this framework.
Lichen 1. Solo fungal and algal partners

Abstract Lichens are slow-growing niche-constructing organisms that form a thallus via scripted symbiotic/mutualistic relationships between fungi, algae, and bacteria, and that are distributed across nearly all terrestrial ecosystems. Here we use quick-freeze deep-etch electron microscopy (QFDEEM) to probe the ultrastructure of a lichen-forming fungus, Cladonia grayi, and its partner alga, Asterochloris glomerata, grown separately (solo) in the laboratory. The solo fungus resembles its lichenized counterpart in: a) general cellular organization; b) the capacity to form lateral branches; c) the production of extracellular materials; and d) the generation of acellular hyphae that we call struts. It differs in carrying a fibrillar coat on its wall exterior and in often adopting two novel plasma-membrane configurations called pleated and pitted. The solo alga also resembles its lichenized counterpart in general cellular organization, but its algaenan-based wall carries a fibrillar coat not evident in the lichen, and its pyrenoid and plastoglobule endowments are less well developed. These findings are followed by four reports on the QFDEEM ultrastructure of four species of lichens, where we describe the differentiations that occur when the fungi and algae are living together in community with bacteria.
Generic determinacy among stationary overlapping generations

For simplicity or realism, determinacy analysis for overlapping-generations models typically aggregates all conceivable commodities into a fixed, finite number of types. Analysis finds robust examples with indeterminate equilibria, which suggests indeterminacy may be significant among overlapping generations. But does robust indeterminacy exist despite that simplifying aggregation? or because of aggregation? We suggest the latter with a generic determinacy theorem for overlapping-generations models with idealized competitive markets for a continuum of commodities in discrete or continuous time. And aggregating the continuum of commodities into a finite number of types transforms some of those generic, determinate models into ostensibly-robust indeterminacy examples.
Wnt signaling in kidney tubulointerstitium during disease

The evolutionary conserved Wnt signaling transduction pathway plays essential roles in a wide array of biologic processes including embryonic development, branching morphogenesis, proliferation and carcinogenesis. Over the past ten years it has become increasingly clear that Wnt signaling also regulates the response of adult organs to disease processes, including kidney disease. This review will focus on the growing literature implicating important roles for Wnt signaling during disease in two separate kidney compartments: the tubular epithelium and the interstitium.
Competition, Saturation, and Inhibition-Ionic Interactions Shown by Membrane Ionic Currents in Nerve, Muscle, and Bilayer Systems*

Publisher Summary This chapter focuses on the passive systems responsible for excitability in nerve and muscle membranes and the analogies that may be drawn with some lipid bilayer systems. It mentions selected papers that serve to outline the chronological accumulation of experimental evidence documenting ionic interaction effects on transmembrane currents. Various nonlipid components added to lipid bilayer membranes enhance their ability to conduct an ionic current under the influence of a transmembrane electric field. Structural and functional properties are consistent with the idea that some of these substances form pores or channels through the membrane lipid, whereas others act as carriers, complexing ions and then diffusing across the lipid phase. A number of theoretical approaches to competition and saturation have been applied with some success to experimental data from bilayer, nerve, and muscle preparations. These analyses have almost invariably been based on reaction rate theory. The chapter compares the details of some of these approaches and discusses the restrictions on the models that are demanded by the cxperimental data from various systems.
Abstract 16730: Prognostic Biomarker for Prediction of Sinus Rhythm Maintenance, Stroke and Long-Term Survival Following Successful Electrical Cardioversion of Non-Valvular Atrial Fibrillation: The Role of Left Atrial Appendage Flow

Introduction: Left atrial appendage (LAA) flow depends largely on left ventricular compliance and may play a role in mediating the regulation of left atrial volume-pressure relationships. Hypothesis: We hypothesize that LAA emptying flow velocity (LAAEV) is a predictive factor of long-term outcomes (e.g. recurrent AF, stroke, and survival) after cardioversion for non-valvular AF. Method: We identified 3,251 consecutive patients with non-valvular AF who underwent successful TEE-guided electrical cardioversion (ECV) at our institution between May 2000 and March 2012. Successful ECV was defined as sinus rhythm at time of discharge from the cardioversion unit. Patients were monitored following their ECV procedure for first documentation of recurrent AF, stroke or death. Multivariate Cox proportional hazards models were used to identify independent predictors of long-term outcomes. Patients with >= moderate valvular regurgitation or stenosis were excluded. Results: Among the 3,251 patients who were successfully cardioverted to sinus rhythm, the mean (±SD) LAAEV was 38.43±23 cm/s and the median was 33 cm/s, (interquartile range [IQR], 20-50). Patients with LAAEV 2 DS 2 -VASc score (2.6±1.2 vs. 1.9±1.3, P =.009), larger LAVI (52.0±20.9 cc/m 2 vs. 43.3±13.6 cc/m 2 , P 33 cm/s. Pre or post-procedure antiarrhythmic drug use was similar between the two groups. During 1-year follow-up, patients with LAAEV 33 cm/s (55% vs 45%, P P P =.003) and mortality (31% vs 23%, P 33cm/s, respectively. Stepwise multivariate Cox regression analysis revealed that LAAEV 2 DS 2 -VASc score were independent predictors of AF recurrence, stroke and mortality. Conclusions: LAA emptying flow velocity is an effective and convenient method for risk stratification of patients undergoing cardioversion for AF. Our data showed that patients with reduced LAAEV have an increased risk for AF recurrence, stroke and death following electrical cardioversion.
Joint estimation and control for a class of stochastic dynamic teams

The authors formulate and solve an infinite-horizon stochastic optimization problem where both the control and the measurement strategies are to be designed simultaneously, under a quadratic performance index. The complete solution to the infinite-horizon problem is provided, the existence of optimal stationary policies is established, and an algorithm for the numerical computation of these policies is given. Thus linear stationary policies are overall optimal and can be obtained from the solution of an infinite-horizon nonlinear deterministic optimal control problem. >
An Abridged Model of the Precession–Nutation of the Celestial Pole

Precise astrometric observations show that significant systematic differences of the order of 10 milliarcseconds (mas) exist between the observed position of the celestial pole in the International Celestial Reference Frame (ICRF) and the position determined using the International Astronomical Union (IAU) 1976 Precession (Lieske et al., 1977) and the IAU 1980 Nutation Theory (Seidelmann, 1982). The International Earth Rotation Service routinely publishes these 'celestial pole offsets', and the IERS Conventions (McCarthy, 1996) recommends a procedure to account for these errors. The IAU, at its General Assembly in 2000, adopted a new precession/nutation model (Mathews et al., 2002). This model, designated IAU2000A, which includes nearly 1400 terms, provides the direction of the celestial pole in the ICRF with an accuracy of ±0.1 mas. Users requiring accuracy no better than 1 mas, however, may not require the full model, particularly if computational time or storage are issues. Consequently, the IAU also adopted an abridged procedure designated IAU2000B to model the celestial pole motion with an accuracy that does not result in a difference greater than 1 mas with respect to that of the IAU2000A model. That IAU2000B model, presented here, is shown to have the required accuracy for a period of more than 50 years from 1995 to 2050.
Fuzzy-neural-sliding mode controller and its applications to the vehicle anti-lock braking systems

One of the major problems in designing the controller for the vehicle anti-lock braking system (ABS) is finding the appropriate control algorithms to reject the parameter uncertainties such as friction coefficient, road elevation, wind gust, road superelevation, vehicle absolute speed, and so on. A new class of algorithms is developed by combining the sliding mode control technique and fuzzy logic control theory with artificial neural networks to achieve the following function: to provide the vehicle with sufficient stopping ability without sacrificing the vehicle stability and the steerability. The proposed fuzzy-neural-sliding mode controller shows that the performance of the vehicle ABS was improved when fuzzy-sliding mode controller was combined with artificial neural networks since artificial neural networks have the abilities of learning and adaptation.
Physics based electro-thermal transient simulation of 4H-SiC JBS diode using Silvaco ATLAS

The unique design of Silicon Carbide (SiC) Junction Barrier Schottky (JBS) diode has proved its superiority over silicon in the field of high energy density pulsed power applications. JBS diode design enables the development of high blocking voltage silicon carbide rectifiers with low ON-state voltage drop, low leakage and negligible reverse recovery. In pulsed power applications, devices get driven above their rated current carrying capacity for a transient duration. Under this scenario, it becomes critical to have a thorough understanding of the electro-thermal behavior of the device under pulsed condition. This research focuses on the design and simulation of a 4H-SiC JBS diode structure in Silvaco ATLAS software under steady state and pulsed conditions. Physics based models were incorporated to account for drift diffusion process, mobility, impact ionization and lattice heating. The JBS diode was designed for a blocking voltage of 3.3 kV and an ON-state current density of 100 A/cm2. A schottky barrier height of 1.1 eV was selected for the device. An array of interdigitated P+ regions with optimized separation was designed to shield the schottky interface from the high blocking electric field without affecting the ON state characteristics. The simulation results were used to analyze breakdown electric field distribution, forward current conduction path, switching performance and areas of localized lattice heating. The diode structure was simulated under pulsed condition pertaining to 500 A/cm2 current density and the lattice temperature profile was analyzed to identify the formation of thermal hot spots in the device lattice and possible failure mechanism. The JBS diode structure was simulated for its reverse recovery at varying magnitudes of turn OFF di/dt for an ON-state current density of 100 A/cm2.
Compressibility and Binding Energy of the Simple Metals

A straightforward calculation of the compressibility, binding energy, and density of the simple metals yields good agreement with experiment. Effects of band structure are included in the perturbation theory, using an electron-ion interaction fitted to experimental data in the region of the zone faces.
Friction characterization experiments on a single point diamond turning machine tool

Abstract Sub-micron precision machining requires very precise position and speed control of the motion of the machine tool axes. The accuracy of coordinated position control determines the profile accuracy of a part in contour machining, while the accuracy of speed control is the most significant factor in the resulting sub-surface damage that may occur in contour or non-contour machining. In high precision machining of brittle materials, it is desirable that the chip removal process be in the ductile regime of the material. The fundamental hypothesis is that if ductile regime chip removal is not accomplished, sub-surface damage will occur on the machined part. Although this can be partially corrected by removing the damaged layer by polishing, that is a very slow manual and costly operation. Therefore, it is desirable to machine such parts at the ductile regime to avoid sub-surface damage. Such a chip removal process requires precise control of feed rates at extremely slow speeds. This motion control problem is difficult due to the large friction and the unpredictable nature of the friction at very low speeds. The standard proportional-integral-derivative (PID) type servo control algorithms are not capable of delivering the desired precision in motion control. The friction must be accurately compensated for by the real-time control algorithm. This requires an accurate means of predicting the friction on-line. To this end, off-line experiments, designed with statistical considerations of factors affecting friction, were conducted. The data collected from these experiments were analyzed to understand the friction characteristics and to develop appropriate model structures for on-line predictions.
Eosinopenia During Last Third of Pregnancy and After Delivery in Several Stocks of Mice. Health Service

SummaryEosinopenia was observed during the last third of pregnancy in several stocks of mice. The mean eosinophil level of females of the Ax and the Zb stock, pregnant 2 weeks and more, was less than half of that noted in non-pregnant mice. Eosinopenia was also noted during the 48 hours following the delivery of the young.
Meta-measures for technology and environment

Purpose – The purpose of this paper is to examine the question: What shall we measure? and offers preliminary answers. Data for innovation management and policy must be valid, reliable, relevant and actionable. Design and approach – The paper examines trends within finance, environment and institutions and society, all with regard to innovation and technology. It examines how these trends interact with each other and with measurement of innovation and socio-technical change. Findings – In the future, measurement for innovation policy must occur in markedly different ways – and on quite different scales – than is currently the practice. The paper concludes with a future-oriented list of items to be measured, with preliminary guidelines on how to organize to measure them. Research limitations/implications – Foresight researchers must put new emphasis on measurement. Practical implications – Local and national statistical agencies will have to measure new indicators and organize differently to measure them. ...
A reengineering framework for small scale software

Reengineering software is approached in different ways, even though the basic process remains the same: reverse engineering followed by forward engineering. Tools are available to aid during reverse engineering and reengineering. This paper presents a framework we used to reengineer a small scale software system from a partial structured implementation to an object-oriented implementation. The framework uses function matrix to organize the extracted abstractions, algorithm tables, and data dictionary during its initial phase. Components for the target system object model are retrieved from the matrices and the dictionary. An empirical reuse metric was applied to the matrix to identify reusable parts. Application of this framework is also discussed.
Solutions of an inverse laminar natural convection problem by subdomain and Galerkin methods

Reconstruction of the velocity field, for a laminar free convection flow, from the knowledge of the temperature distribution, within the flow, is an inverse heat transfer problem. In this investigation, the velocity profile for a laminar convective flow along an isothermal vertical plate is reconstructed using known temperature distributions. The temperature distributions used in this inverse problem were generated numerically from the direct similarity solutions. To solve this inverse problem, continuity, momentum and energy equations are considered. To obtain the velocity solutions (profiles), the Galerkin and subdomain weighted residual methods are employed. The velocity solutions are represented by the sum of n-term weak functions satisfying the boundary conditions. The solutions considered in this study belong to a family of sine and polynomial functions. Comparison of the inverse solutions with the direct solutions confirms that velocity profiles can be reconstructed from the knowledge of temperatur...
Primary separation between three aircraft using traffic displays

This study explored the use of cockpit traffic displays for aircraft separation in instrument conditions. This is a new concept termed EFR for electronic flight rules. Four groups of three general aviation, instrument-rated pilots flew cross-country flights in twin engine simulators in the Multi-Cockpit Facility at NASA Ames. They were required to maintain two miles horizontal and 500 feet vertical separation from all other aircraft. There were 24 different geometries, or traffic situations, repeated randomly for each of the four experimental conditions for each group. Of 1152 aircraft encounters 12.8% were in violation of separation minimums. Eighteen of these were closer than 400 ft vertically or 1.6 nm horizontally. The minimum separation of all aircraft pairs was 293 ft and .13 nm. The type and time of evasive maneuvers showed no effect when sensor noise was simulated in the displayed traffic information. When pilots were able to communicate and coordinate their maneuvers, the time to resolve the conflict was reduced. Subject groups varied significantly in: time of conflict resolution, frequency and type of maneuvers, control activity, reported amount of threat, confidence, and satisfaction they perceived, and appraisal of the efficacy of their communications. Language: en
Schistosomiasis as a worldwide problem: Pathology

Low-grade schistosome infection is often well tolerated, except for the danger of ectopic lesions; the risk of life-threatening pathology increases with rising worm burdens. At present, quantitative stool or urine egg counts do not reliably measure individual infection intensity, especially in adult patients, and more precise methods are needed on which to base therapeutic decisions. Timely schistosomicidal treatment will prevent or improve bilharzial lesions, often dramatically, but can not reverse established liver pipe stem fibrosis. Pathological studies in Ibadan and Cairo have shown that in schistosomiasis haematobia the frequency of obstructive uropathy increases in relation to the egg load in urinary tissues. Obstruction, in turn, predisposes to bacterial superinfection and is a significant cause of renal failure and death in highly endemic populations. Urinary bilharzial lesions are most active in the young and tend to become inactive in older patients. Urinary tissue egg burdens first rise, plateau, and ultimately decrease with age, most sharply after the fifth decade. The relationship between tissue egg burden and 24-hr urinary egg output varies according to stage of activity, while the severity of disease depends on egg burden regardless of stage. Therefore, during the inactive stage, severe pathology can coexist with a minimal urinary egg output. Both clinical and autopsy statistics show a correlation between the frequency and the intensity of bilharzial infection. Most of the severe pathology occurs in population groups with an autopsy frequency above a threshold of 30%. The clinical and epidemiological implications of these findings are discussed.
Engineering¿Outside the Box

Many times during an engineer's career, assignments will be given that don't seem to fit the normal approaches or canned solutions. While looking at the problem, frequent comments will be heard, lCan't be done,r lIt's never been done,r lTried it. Didn't work,r lA waste of time and money,r and the list goes on. The comments may come from other engineers or even management. Regardless of the source, the comments don't build a lot of confidence in the engineer with the assignment. The people offering the comments may be, in their opinion and experience, offering their honest assessment. The solution simply does not fit into their paradigm. They have firmly entrenched themselves into a philosophical or theoretical framework that won't allow them to think of a new approach. They can't make that theoretical shiftmthey are not comfortable with a paradigm shift. The shift doesn't have to be radical, it simply means that they have to change their beliefs or theory. They have to think outside the box.
MGMT promoter methylation, loss of expression and prognosis in 855 colorectal cancers

O6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme. MGMT promoter hypermethylation and epigenetic silencing often occur as early events in carcinogenesis. However, prognostic significance of MGMT alterations in colorectal cancer remains uncertain. Utilizing a database of 855 colon and rectal cancers in two prospective cohort studies (the Nurses’ Health Study and the Health Professionals Follow-up Study), we detected MGMT promoter hypermethylation in 325 tumors (38%) by MethyLight and loss of MGMT expression in 37% (247/672) of tumors by immunohistochemistry. We assessed the CpG island methylator phenotype (CIMP) using eight methylation markers [CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1], and LINE-1 (L1) hypomethylation, TP53 (p53), and microsatellite instability (MSI). MGMT hypermethylation was not associated with colorectal cancer–specific mortality in univariate or multivariate Cox regression analysis [adjusted hazard ratio (HR) = 1.03; 95% confidence interval (CI), 0.79–1.36] that adjusted for clinical and tumor features, including CIMP, MSI, and BRAF mutation. Similarly, MGMT loss was not associated with patient survival. MGMT loss was associated with G>A mutations in KRAS (p = 0.019) and PIK3CA (p = 0.0031). Despite a well-established role of MGMT aberrations in carcinogenesis, neither MGMT promoter methylation nor MGMT loss serves as a prognostic biomarker in colorectal cancer.
Local decomposition of gray-scale morphological templates

Template decomposition techniques can be useful for improving the efficiency of imageprocessing algorithms. The improved efficiency can be realized either by reorganizing a computation to fit a specialized structure, such as an image-processing pipeline, or by reducing the number of operations used. In this paper two techniques are described for decomposing templates into sequences of 3×3 templates with respect to gray-scale morphological operations. Both techniques use linear programming and are guaranteed to find a decomposition of one exists.
The Influence of Les Morris

In December 2008, we lost Les Morris, the editor and founder of this journal. We will miss his guidance, insight, and companionship. Here is what his friends, family, and colleagues remember about ...
Operation Of Monolithic Laser/Multiplexer Optoelectronic IC

We have demonstrated the first operational integrated optoelectronic circuit which combines a semiconductor laser diode with small-scale (36 gates) GaAs circuitry. The successful development of this technology has demonstrated one of the key elements for high speed optical interconnects using fabrication techniques which are compatible with medium to large scale integration. Due to the different and often conflicting requirements for high performance lasers and electronics, only very elementary integrated laser/driver structures (less than six transistors) have been reported until now. We have designed and fabricated an integrated optoelectronic transmitter containing a tranverse junction stripe (TJS) laser, a field effect transistor (FET) driver, and a 4:1 multiplexer (Mux). The Mux and driver active regions are formed by selective ion implantation while the TJS laser is fabricated in epitaxial layers grown in a well that is etched into the substrate. The Mux consists of 36 SDFL (Schottky diode FET logic) NOR gates. The MESFETs in the GaAs circuit have 1 micron gate lengths and a 1.2V threshold voltage. The transmitter chip has been tested at 160 MHz clock rates. Higher speeds are possible.
Noise characteristics of heated high velocity rectangular jets

Abstract A comprehensive experimental investigation of the noise emission from a rectangular jet has been carried out. In order to provide information pertinent to the operating conditions of jet engines, this study was conducted with a wide range of jet velocities and temperatures. A substantial effort has been made to present the information in this paper in such a fashion as to delineate the effects of turbulent mixing and acoustic shielding. To aid in this process, a round jet with an equal area nozzle was also tested over the same ranges of velocity and temperature. As a result of this study, it is concluded that an observed reduction in overall acoustic power of the rectangular jet, when compared to a round jet, is mainly the result of the shielding effects of the mean velocity and temperature fields rather than due to any turbulent mixing phenomenon. Acoustic shielding predictions were found to be qualitatively valid in the vicinity of the peak intensity but were inadequate at shallow angles to the jet axis. In order for shielding theory to properly predict the noise of non-circular jets, at shallow angles, it appears that it will be necessary to include the effects of jet spreading and subsequent degeneration to a circular jet as well as the effects of off-axis source locations.
A comparison of arginase maximum velocities from several poikilotherms and homeotherms.

Abstract 1. 1. Maximum velocities ( V max ) were determined for hepatic arginase from several different species of amphibians (poikilotherms) and mammals (both hibernators, facultative homeotherms; and non-hibernators, obligate homeotherms) at three different assay temperatues (4, 25, and 37°C). 2. 2. It appears that the V max of arginase from poikilotherms and facultative homeotherms may be greater than the V max of arginase from obligate homeotherms at all assay temperatures. 3. 3. A higher V max may indicate an enzyme with a more flexible tertiary structure. 4. 4. The data appear to show that the ability to exhibit periods of torpor may be widespread among small mammals.
Papillary endothelial hyperplasia presenting as recurrent malignant glioma

The initial management of patients with malignant gliomas depends on accurate histologic diagnosis which, in turn, directs appropriate treatment planning. However, the diagnosis of recurrent disease is often based solely on radiological data which can occassionally be misinterpreted as showing recurrent tumor. Lack of awareness of conditions that mimic recurrent tumor and potentially confound radiological diagnosis can lead to inappropriate therapeutic decisions. We report the case of a patient whose imaging studies suggested recurrence of malignant glioma; however, surgical resection of the lesion guided by MRI scans resulted in the correct diagnosis of papillary endothelial hyperplasia and led to appropriate management of this condition that mimicked tumor recurrence. In this report, we provide a comprehensive review of this rare entity and emphasize the importance of adequately pursuing appropriate diagnostic considerations prior to making definitive treatment decisions.
Starting-time decisions in labor tour scheduling: An experimental analysis and case study

Abstract Many service organizations limit the number of daily planning periods in which employees may begin their shifts to a fixed number, S . Even for relatively small values of S , which are quite common in practice, there may be hundreds, thousands or millions of possible subsets of starting times. This paper presents the results of a large experimental study that revealed that, in many instances, only a very small portion of starting-time subsets was capable of providing the minimum workforce size. The importance of effective starting-time selection is further supported by a case study that describes a spreadsheet-based program designed for scheduling customer service representatives in the System Support Center, United States and Canada Group, Radio Network Solutions Group, Land Mobile Products Sector, Motorola.