cssi/SciSciGPT-SciSciNet huggingface dataset:
TU‐A‐L100F‐01: Quality Assurance Procedures for Digital Radiography

Diagnosticmedical physicists have traditionally played a key role in the radiology department's Quality Assurance (QA) program. Procedures for QA of digital radiography (DR) systems are less well‐established than those designed for conventional screen‐film radiography. Some methods that were appropriate for conventional systems do not yield accurate results for digital systems. Methods that rely on images on film cannot be performed in a facility devoid of chemical processing. Methods that do not consider effects of all stages of the digital imaging chain from acquisition to display are likely to provide erroneous results. Digital systems often do not provide data in a convenient form for assessing performance. Nevertheless, medical physicists are responsible for designing and directing efforts to assure the safety and efficacy of DR. Development of standards for performance verification of digital radiographic systems has been outpaced by commercialization of the technology. Practitioners, operators, vendors, and medical physicists are uncertain as to how to configure, calibrate, and verify systems for the best diagnostic quality images at the lowest practical radiation exposure to the patient. Several manufacturers have fielded commercial systems for performance verification, but long term data indicating trends and action limits is rare. Sources of definitive information on practical clinical methods are also scarce in the scientific literature. This has led to the current situation where clinical imaging operations are routinely conducted using systems that are not optimized. The good news is that methods in common practice for conventional radiography can be applied with modification to digital radiography. Some of these methods are described in recent literature. The AAPM has recognized the dilemma and has initiated an effort to provide practical guidance to clinical physicists, i.e. Task Group 150. This lecture will discuss some components of a QA program for DR, including adaptation of conventional QA processes. The lecture will discuss methods of evaluating system performance and provide examples of potential interferences. The lecture will review commercial devices for performance evaluation and their limitations. Finally, some ongoing standardization efforts will be described. Educational Objectives: 1. Review components of a QA program and show how they apply to DR. 2. Understand how some conventional tests should be modified for a digital radiographic system integrated into an electronic image management system. 3. Identify key references and standards that can be useful in QA of DR.
Fabrication of bismuth ferrite nanofibers via electrospinning

Bismuth ferrite (BFO) has attracted great attention not only because it's potential applications as multiferroic material in the spintronics and in micro-electromechanical system but also because of its photo-electronic behavior in energy harvesting. In this investigation we report the fabrication of multiferroic BFO nanofibers via electrospinning. Bismuth ferrite nanofibers were deposited on oxidized silicon and quartz substrates using sol-gel based electrospinning technique. The diameter of the fibers was well controlled by varying the molarity ratio of the precursor solution. X-ray photoelectron spectroscopy (XPS) results showed a combination of Fe3+ and Fe2+ valence states in the fibers. Rutherford back scaterring spectroscopy (RBS) result showed a stoichiometry composition after heat treatment. Both scanning electron microscopy (SEM) and atomic force microscopy (AFM) images revealed that the fibers diameter is uniform ranging from 15 to 100nm and several microns in length.
End-User Programming of 3D Virtual Agents

3D interactive environments filled with compelling characters are becoming part of our everyday lives. For example, 3D graphical scenes are common in video games, advertisements, and movies. However, the uses of the characters in these environments have been explored in only a limited way. We would like to significantly increase the utility of animated characters in such environments with respect to effective education and training. In this project, we aim to advance the state of the art in end-user programming by supporting the development of 3D animated content by end users for the purpose of training other users. In particular, we are interested in strategy-oriented programming in virtual worlds, in which synthetic characters are programmed to select and execute appropriate strategies. The purpose is to support domain experts in creating the characters' content for virtual training environments, such as for emergency personnel training or educational simulations, without requiring the content creators to have prior knowledge of computer science or animation. We propose to support end users in programming these synthetic characters as directly as possible, by sketching and demonstrating desirable behaviors with characters from their own problem domains. For example, a football coach might create animated synthetic players and implicitly train them to have complex strategies and behaviors. These synthetic agents will be used to train humans in complex strategies and behaviors by having them play against and with each other. Similar virtual environments can be used to train firefighters, military personnel, emergency workers, and children learning problem-solving skills via educational simulations
Pressure-Driven Flow of Wormlike Micellar Solutions in Rectilinear Microchannels

Abstract In this paper the inhomogeneous response of the (two species) VCM model (Vasquez et al., A network scission model for wormlike micellar solutions. I. Model formulation and homogeneous flow predictions, J. Non-Newtonian Fluid Mech. 144 (2007) 122–139) is examined in steady rectilinear pressure-driven flow through a planar channel. This microstructural network model incorporates elastically active network connections that break and reform mimicking the behavior of concentrated wormlike micellar solutions. The constitutive model, which includes non-local effects arising from Brownian motion and from the coupling between the stress and the microstructure (finite length worms), consists of a set of coupled nonlinear partial differential equations describing the two micellar species (a long species ‘A’ and a shorter species ‘B’) which relax due to reptative and Rouse-like mechanisms as well as rupture of the long micellar chains. In pressure-driven flow, the velocity profile predicted by the VCM model deviates from the regular parabolic profile expected for a Newtonian fluid and exhibits a complex spatial structure. An apparent slip layer develops near the wall as a consequence of the microstructural boundary conditions and the shear-induced diffusion and rupture of the micellar species. Above a critical pressure drop, the flow exhibits shear banding with a high shear rate band located near the channel walls. This pressure-driven shear banding transition or ‘spurt’ has been observed experimentally in macroscopic and microscopic channel flow experiments. The detailed structure of the shear banding profiles and the resulting flow curves predicted by the model depend on the magnitude of the dimensionless diffusion parameter. For small channel dimensions, the solutions exhibit ‘non-local’ effects that are consistent with very recent experiments in microfluidic geometries (Masselon et al., Influence of boundary conditions and confinement on non local effects in flows of wormlike micellar systems, Phys. Rev. E 81 (2010) 021502).
Grammatical analysis of the prediction of binary events

College students pushed buttons to predict which of two lights would appear, as in probability learning, except that the lights formed a periodic and therefore predictable sequence. The process of predicting was thought of as a system of grammatical rules. Locations in the sequence generated by mandatory first-order rules were learned quickly and all-or-none; locations generated by optional first-order rules were learned with more errors and in at least two stages. The systems of rules enable Ss to recode the sequence into run lengths (integers). Some typical higher-order rules were suggested.
Sociocultural Boundary Formations in College Life and Intercultural Capital Development

Based on selective findings from a qualitative study with first generation college students, this article presents the contradictory and complex ways in which the participants perceived sociocultur...
Definition and quantitation in ecology.

AUSTIN1, in commenting on my communication2, has provided an example of the problems which arise in justifying a non-quantitative approach to a subject such as ecology. Austin attaches significance to an imprecision of definition in my examination of the relationships among functional properties of Californian grasslands, and concludes “more adequate definitions are necessary before McNaughton's suggestions … can profitably be examined”. A critical examination of this proposition shows it to be erroneous. A summary of the data required by such an examination is included (Table 1).
Quaternary stratigraphy of the Charlotte Harbor estuarine-lagoon system, southwest Florida: Implications of the carbonate-siliciclastic transition

Abstract Charlotte Harbor is a complex lagoon and estuarine system in southwestern peninsular Florida that is underlain by Tertiary carbonates and Quaternary siliciclastic sedimentary sequences. High-resolution seismic profiling, vibracores, and sediment samples from modern environments have been used to interpret the Quaternary stratigraphy and evolution of this system. The underlying Tertiary carbonates have undergone extensive dissolution and collapse which has created isolated karst depressions and fracture-controlled, elongated troughs. Although late Neogene deposition infilled most of the pre-Quaternary relief, the Quaternary drainage system was controlled by the poorly integrated, vertical drainage of the karstified limestones which is unlike the well-integrated paleofluvial drainage systems of the mid-Atlantic and northern Gulf coastal plains. Despite these differences, paleotopography and sediment availability have controlled locations and sedimentary environments as has been noted in other published studies on purely siliciclastic systems. The distribution of three interpreted Quaternary depositional sequences (fluvial to upper estuarine point bar fining upward sequence (FUS), transitional estuarine sequence and tidal channel-delta FUS) and the mapped distribution of an early-middle Pleistocene seismic unconformity indicate that Quaternary sea-level fluctuations have repeatedly caused coastal systems to migrate through the area, leaving records of at least two Pleistocene barrier-lagoon systems. These systems straddled the infilled karst depressions and were apparently controlled by the availability of erodible sediment that infilled the depressions. The modern barrier system is perched upon one of the Pleistocene barrier platforms which has been preserved as a result of lithification of carbonate-rich inlet-tidal delta deposits. These platforms should preserve the backbarrier deposits from future shoreface incision but localized channelization will cause extensive reworking. Because the paleofluvial channels do not extend offshore, preservation on the inner shelf (> 5–7 km offshore) is limited to isolated karst depressions where Tertiary limestones are exposed.
A Molecularly Imprinted Fluoral-P/Polyaniline Double Layer Sensor System for Selective Sensing of Formaldehyde

We demonstrate the capacity of a double layer thin-film system, composed of polyaniline and fluoral-p, to sensitively detect and selectively bind formaldehyde vapor using an interdigitated electrode assembly. The sensor response scales with the concentration of formaldehyde vapor and does not respond significantly to other potentially interfering molecules. This heightened response and selectivity result from imprinting the polyaniline layer with a molecular memory for ammonia. The chemistry of the double layer detection is discussed in terms of the Hantzsch reaction and the p-type semiconducting activity of polyaniline.
An Integrated Approach to Graduate Education in Manufacturing Systems—The U.T. Dallas Model

A graduate program in Manufacturing Systems has been designed by the faculty of the University of Texas at Dallas and a fourteen member industrial advisory committee using a top-down approach. By establishing an independently administered program with it's own faculty, it was possible to design “de-novo” a highly integrated set of new courses in a structured curriculum built around the central theme of the design of computer supported/controlled systems for engineering and manufacturing. There are nine required courses organized under the categories of manufacturing processes, process control, computer systems, product design, manufacturing systems, and business principles. A manufacturing project caps off the curriculum.
Optimizing Poultry House Design for Broiler Chickens

Abstract Ten equations that interrelate poultry house design, ventilation and heating, broiler chicken characteristics, and climate are described. The equations have been developed for solution by microcomputer. Results illustrate how the equations can be used to optimize poultry house design and operation. For 1–lb broiler chickens stocked at 0.8 ft2 /bird in a house with R = 4 insulation, heat from the birds will maintain 70 F inside temperature and 70% relative humidity unless outside temperature drops below 53 F. If insulation is increased to R = 8, outside temperature can drop t o 45 F before relative humidity exceeds 70% in a house maintained at 70 F. When supplemental heat is required to prevent relative humidity in a house from exceeding 70% when the weather is cold, lowering inside temperature will reduce heat requirements in a poorly insulated house. If insulation is greater than R = 4, however, lowering inside temperature may increase heat requirements to prevent excessive humidity.
The effects of some centrally acting drugs on the glucocorticold induction of hepatic tyrosine transaminase

Abstract The effects of some centrally acting drugs on hepatic tyrosine transaminase activity with and without cortisol in the adrenalectomized male and female rat have been determined. Tyrosine transaminase activity in the female adrenalectomized rat is higher than in the male and is less sensitive to drug augmentation of cortisol induction. Cortisol induction of tyrosine transaminase can be augmented by SKF 525-A 3 hours after cortisol injection. Induction of the enzyme by 16β-methylprednisone, oxylone, and fluocinolone acetonide can be augmented by SKF 525-A and by chlorpromazine.
Community-based strategies for coping with food scarcity: A role in African famine early-warning systens

The effectiveness of Famine Early Warning Systems (EWS) being used in Africa is being questioned because they are unable to provide sufficiently accurate information on the specific locations vulnerable to food scarcity. The data currently used to asses the emergence of local deficits are criticized as being inaccurate or belated. The range of strategies for coping with food deficits used by farmers and herders in rural Africa offers an alternative set of information which has the potential for improving the spatial specificity of EWS.
Defect Diffusion in Single Crystals and Polycrystals of Co1‐xO

The chemical diffusion coefficient in nonstoichiometric Co1−xO was measured at T=800° to 1040°C and an oxygen pressure range of 10 Pa≤PO2≤105 Pa, in which singly ionized cation vacancies were established as the predominant defect species. The oxidation and reduction kinetics for single crystals and polycrystalline samples are controlled by bulk diffusion. The chemical diffusion coefficient obtained for single crystals is represented by This value is equal to twice the cation vacancy diffusivity and is independent of defect concentration. The chemical diffusion coefficient for polycrystalline Co1−xO increases with decreasing grain size. The enhanced diffusion in fine-grained materials is attributed to oxygen defect transport in the grain-boundary region. For coarse-grained samples with grain sizes >30 μm, the chemical-diffusion coefficient is similar to that obtained for single crystals. These data correlate well with other studies of mass transport in cobalt oxide which indicate that, in fine-grained samples, oxygen diffusion in the grainboundary region is faster than cobalt diffusion in the lattice. A transition in rate-controlling steps is observed in going from fine to coarse-grained material. This is the first direct observation of enhanced defect transport in polycrystalline Co1−xO.
Additional standardized interview data for emotionally disturbed children.

Dinoff and Griffin (1968) have reported data on a standardized interview from emotionally disturbed children. They used a variation of [he rules of the interview developed by Matarazzo, e t al. (1957) and used with children by Dinoff, ec al. (1968). Dinoff and Griffin (1968) showed that there were differences between emotionally disturbed children and normal youngsters at similar ages and grade levels. Because of an error in the administration of their interviews with emotionally disturbed children they were unable to compare performance on all the usual measures of the standardized interview and could report only a few of the traditional indices. In the present study 18 emotionally disturbed boys spending a summer at Camp Ponderosa ( a program for the mild to moderately emotionally disturbed child in Mentone, Alabama) were interviewed during the 7 X w k session. Table 1 data were broken down by grade placement and in terms of the usual measures found in Matarazzo, et al. (1957). These data are by no means complete. They are meant to supplement the earlier data of Dinoff and Griffin (1968) for emotionally disturbed children. Again, as in the earlier data no developmental trends are evidenced; however, the number in each cell is small. Furthermore, no attempts were made to diagnose children but ir is probable that nosology was unbalanced. More data are needed.
Multifield, temperature and concentration dependence of spin relaxation and local motion in 2,2-propane diyl-bis(4-hydroxyphenyl) polyformal

Abstract 13 C and proton spin-lattice relaxation data were determined as a function of field, temperature and concentration for 2,2-propane diyl-bis(4-hydroxyphenyl) polyformal in C 2 D 2 Cl 4 . The concentration of polymer was varied from a few per cent by weight up to the bulk rubber and temperature was varied from −20°C to +120°C. The relaxation data is interpreted in terms of several local motions including segmental motion, phenylene group rotation, methyl group rotation and formal group rotation. Segmental motion is described by a correlation function developed by Hall and Helfand which allows for cooperative and single bond transitions. The phenylene group rotation is described by the Woessner anisotropic stochastic diffusion model except at high concentration (⩾50 wt%) where the phenylene data is simulated by restricted rotation. Methyl group rotation is described by the Woessner three fold jump model, and the formal group rotation is described by double trans-gauche rotations about the C-O axes. At a concentration of 5 wt%, the time scale of segmental motion is slightly slower than in bisphenol-A-polycarbonate. However, the time scales of phenylene group and methyl group rotations are nearly identical for both polymers. A comparison is also made with chloral polyformal, another similar polyformal. The effect of concentration on local motion was monitored by 13 C spin-lattice relaxation measurements at three Larmor frequencies over the range of 5 to 100 wt% polymer at a temperature 40°C above the glass transition of this polyformal. The rate of local chain motion decreases as the concentration of polymer increases with the exception of methyl group rotation which remains constant. The correlation times for several local backbone motions are fit to free volume theory which yields a fractional free volume of 0.38 for the solvent (C 2 D 2 Cl 4 ) and 0.28 for the polymer.
Radiosynthesis of [F-18]fluoxetine as a potential radiotracer for serotonin reuptake sites

Abstract Synthesis of 4-nitro-α-bromo-α,α-difluorotoluene was accomplished in two steps starting from 4-nitrobenzaldehyde, with a 30% overall yield. Radiolabeling of 4-nitro-α-bromo-α,α-difluorotoluene with no-carrier-added [ 18 F]fluoride provided 4-nitro-α,α-difluoro-α-[ 18 F]fluorotoluene in 2–4% yields with a specific activity of 2590 GBq/mmol (70 Ci/mmol). The effect of the reaction temperature on the radiochemical yield and specific activity of the radiolabeling reaction was studied. Radiochemical yields increased, whereas specific activity decreased, with increasing temperature. Radiosynthesis of [ 18 F]fluoxetine involved coupling of 4-nitro-α,α-difluoro-α-[ 18 F]fluorotoluene with the sodium alkoxide of ( S )-3-(methylamino)-1-phenyl-1-propanol. The overall yield of HPLC purified [ 18 F]fluoxetine was 1–2% (decay-corrected; total radiosynthesis time, 150–180 min). The specific activity of the product was 1480 GBq/mmol (40 Ci/mmol).
Center for the Prevention of Secondary Conditions After Spinal Cord Injury: Background and Overview of Coordinated Activities

Purpose: To provide an overview of the Rehabilitation Research and Training Center on Secondary Conditions in Individuals with SCI. Methods: There are several limitations that have inhibited research on secondary conditions after spinal cord injury (SCI), including the lack of population-based studies and the lack of systematic study of common risk factors across secondary conditions. The Rehabilitation Research and Training Center (RRTC) uses a mixture of research, education and training, dissemination, and technical assistance to address secondary conditions after SCI. Three proposed studies will further the understanding of secondary conditions by addressing limitations of previous research. Along with the proposed research, training will take place at multiple levels, including undergraduate, graduate, and medical students, and in a diverse pool of health care providers. Conclusion: The ultimate goal of this RRTC initiative is to increase knowledge and ability to predict and prevent secondary conditio...
Ultrasonic imaging of biochemical changes in tissues

Advanced breast carcinomas are complex mixtures of epithelial, stromal and inflammatory cells with heterogenous, chaotic blood flow. Elevated cell metabolism and poor perfusion causes an acidic (pH 6.2) and hypoxic environment that has a significant influence on the effectiveness of therapies and leads to aggressive cancer cell phenotypes. We propose to indirectly image the effects of metabolism (acidity) using viscoelastic imaging on the basis that environmental pH alters the stromal collagen structure. Viscoelastic imaging describes elastic properties of tissue in addition to viscous components characterized by time constants. We first prove our hypothesis using a physical model such as tissue mimicking gelatin and demonstrate the feasibility of imaging effects of local pH changes. Injecting acids and bases produced dark strain contrast that grew in size and intensified over time unlike neutral pH injections that produced no strain contrast. We interpreted the images using an independent measurement of pH dependent viscoelasticity using a cone viscometer that showed that average elastic strain was double valued around neutral pH while viscous relaxation time constants increased with pH. Acidic regions in ex-vivo liver samples produced similar trends with greater contrast intensity compared to gelatin because of gelatin's greater buffering capacity. A clear advantage of mapping viscous time constants over just strain (elasticity), is a much weaker dependence on boundary effects. We also show preliminary clinical applications and found that trained operators tended to naturally apply constant stress rather than constant strain in hand-held situations unlike mechanically driven devices. Above results suggest that pulse-echo ultrasound without contrast enhancement has the potential to image alterations in stromal tissue structures caused by biochemical changes.
HTS bearings for space applications: reaction wheel with low power consumption for mini-satellites

Superconducting bearings have very low coefficients of friction. It is promising to exploit this feature of HTS bearings in the construction of reaction wheel systems that consume meager power. Reaction wheel systems that consume little power are particularly suitable for use on mini-satellites where both energy and power are scarce resources. Thus, these mini-satellites can still have attitude control capabilities without prohibitive requirements for total volume and weight of hardware, and power consumption. Here, we will present the design and discuss the performance of a prototype with a 1.9 kg stainless steel wheel of diameter 82.5 mm, and height 75 mm, which can store 3.5 J-sec of angular momentum when it rotates at an angular speed of 15000 RPM. We have performed spin down tests from 7000 RPM down and measured the input power required to sustain rotational speed under a vacuum of 0.01 torr. Implications of the results are discussed.
Can microcomputers identify differences in health status between different groups

(1986). Can Microcomputers Identify Differences in Health Status between Different Groups? Health Education: Vol. 17, No. 2, pp. 37-42.
Proglacial lake sediment records of Holocene climate change in the western Cordillera of Peru

Abstract Sediment records from proglacial lakes between 9 and 10°S in the western Cordillera of the Peruvian Andes document the waxing and waning of alpine glaciers since the end of the Lateglacial stage. These records from the southern tropical Andes provide supporting evidence that the early Holocene (between 12 and 8 ka) was relatively warm and dry, and the middle Holocene (between 8 and 4 ka) was marked by a shift to cooler, and possibly wetter conditions in certain regions, leading to glacial advances. Although there were multiple periods of brief ice advances that interrupted the overall trend, glaciers in multiple valleys generally retreated from ∼4.0 ka through the Medieval Climate Anomaly (1.0–0.7 ka). This late Holocene pattern of ice retreat occurred during a period when lake level studies, and both lacustrine and speleothem stable isotopic records indicate wetter conditions relative to the middle Holocene, suggesting that higher temperatures contributed to the pattern of ice retreat. Following this period of glacial retreat, multiple proxy records suggest that the start of the Little Ice Age (∼0.6–0.1 ka) was a colder and wetter time throughout much of the tropical Andes. There appear to be two primary synoptic-scale climatic controls on temperature and precipitation linked to insolation dynamics that drive changes in ice cover in the southern tropical Andes during the Holocene: 1) the strength of the South America Summer Monsoon, which is linked to Northern Hemisphere temperatures and the mean position of the Intertropical Convergence Zone over the Atlantic, and 2) sea surface temperature distributions in the tropical Pacific Ocean and its influence on atmospheric temperature, precipitation and circulation patterns.
Deposited Dielectric Profiles in Complex Semiconductor Circuits

DEPOSITED DIELECTRIC PROFILES-IN COMPLEX SEMICONDUCTOR CIRCUITS Oxide profiles are a critical parameter in a production of reliable multi-layer monolithic circuits. These deposited dielectrics serve to insulate overlapping metal layers while simultaneously allowing fabrication of high density circuitry within a minimized die area. Foremost among the desirable qualities of these dielectrics is their ability to adequately cover both metal and oxide on the flat surfaces of the die as well as over the steps. Poor coverage can result in a variety of catastrophic electrical problems which lead to both expensive and inefficient processing. Until recently the direct observation of integrated circuit surfaces has been limited to optical and metalographic methods. Scanning Electron Microscopy provides a useful means of obtaining the detailed and descriptive information necessary to characterize oxide and metal profiles. Three phases of oxide coverage were studies in this program using the Scanning Electron Microscope: (1) Deposited oxide over thermal oxide (2) Deposited oxide over metal patterns (3) Growth profiles of deposited oxides Phase I has shown how deposited oxide replicates its thermal counterpart. Phase II, on the other hand, has yielded valuable information about the effect of underlying metal profiles on oxide deposition. The details of how deposited oxides establish their final configurations have been demonstrated by varying oxide thickness and observing surface profiles in Phase III.
Possible explanation for the white band artifact seen in clinically retrieved polyethylene tibial components

Studies have focused attention on the appearance of a subsurface white band in clinically retrieved polyethylene components and the possible contribution of this phenomenon to early polyethylene delamination. Unconsolidated polyethylene particles and oxidation have been suggested as possible reasons for the appearance of the white band. Calcium stearate and other additives used in processing ultra-high molecular weight polyethylene may also contribute to formation of the white band. A quantitative investigation was conducted on 11 retrieved tibial components that exhibited a subsurface white band to determine whether the amount of calcium stearate particles and additives were greater in the white band region when compared with the mid-portion of the same section of polyethylene. Calcium stearate particles and other additives were quantified using backscattered electron imaging with correlated elemental analysis. The particles were identified based on morphology and elemental patterns similar to reference calcium stearate particles and known additives. Significantly more (p < 0. 0001) calcium stearate particles and additives were present in the white band region (4578 +/- 418 particles/mm(2); mean +/- standard error) than the mid-portion region (1250 +/- 147 particles/mm(2)) of the sectioned tibial inserts. The percent area occupied by calcium stearate particles and additives was five times higher (p < 0.0001) within the white band region (0.81 +/- 0.10%) than the mid-portion region (0.16 +/- 0.03%). The increased presence of calcium stearate and other additives in the white band region suggests that they may play a role in the formation of the white band. In future investigations it may be important to consider how calcium stearate and other additives in polyethylene resins affect white band formation and the possible contribution to crazing, early delamination, and osteolysis in total joint replacement.
Incremental switch-level simulation with zero/integer-delay

The authors present the methods used in the implementation of an incremental zero/integer-delay switch-level logic simulation for MOS circuits based on the MOSSIM II switch-level model. Zero-delay timing reduces spurious re-evaluations caused by minor changes to signal timing that do not affect logic, while integer-delay timing, a generalization of unit-delay methods, provides an ability to model race conditions that do affect the logic. The incremental simulator is embedded within a fully-integrated capture-compile-simulate tool. Modifications to the design at any level in the structural design hierarchy are automatically mapped into (possibly many) changes in the underlying transistor netlist and the incremental simulator is triggered to quickly resimulate only the affected regions of the circuit. >
Analyzing the input stream for character- level errors in unconstrained text entry evaluations

Recent improvements in text entry error rate measurement have enabled the running of text entry experiments in which subjects are free to correct errors (or not) as they transcribe a presented string. In these “unconstrained” experiments, it is no longer necessary to force subjects to unnaturally maintain synchronicity with presented text for the sake of performing overall error rate calculations. However, the calculation of character-level error rates, which can be trivial in artificially constrained evaluations, is far more complicated in unconstrained text entry evaluations because it is difficult to infer a subject's intention at every character. For this reason, prior character-level error analyses for unconstrained experiments have only compared presented and transcribed strings, not input streams. But input streams are rich sources of character-level error information, since they contain all of the text entered (and erased) by a subject. The current work presents an algorithm for the automated analysis of character-level errors in input streams for unconstrained text entry evaluations. It also presents new character-level metrics that can aid method designers in refining text entry methods. To exercise these metrics, we perform two analyses on data from an actual text entry experiment. One analysis, available from the prior work, uses only presented and transcribed strings. The other analysis uses input streams, as described in the current work. The results confirm that input stream error analysis yields richer information for the same empirical data. To facilitate the use of these new analyses, we offer pseudocode and downloadable software for performing unconstrained text entry experiments and analyzing data.
The potential and limits for clinical trials for early Alzheimer’s disease and some recommendations

Recommendations for clinical trials methods for 'pre-dementia,' 'prodromal,' or early Alzheimer's disease are discussed. Early AD can be considered as subsets of both 'amnestic MCI' and 'probable AD.' In principle, it can be operationalized using recently proposed, new research criteria for AD that specifically does not require impairment in non-memory cognitive function and activities of daily living, and consequently does not require the presence of dementia. The criteria also require patients to show abnormal putative biomarkers but require validation. Trials in early AD should be done when models of drug action and response suggest that the drug in development likely would be effective in early AD and clinical effects could be expected in a relatively short time. Biomarkers should be used as stratification or explanatory variables that may help to explain clinical outcomes from early AD trials rather than as inclusion/exclusion criteria in order to avoid pseudospecificity. Trials should be multicentered, double-blinded, randomized, placebo-controlled, generally with dose-ranging of two doses if indicated. Duration of trials should be based on expected onsets and durations of effects, and generally should be less than one year. Crossover trials should be considered when appropriate. Primary outcomes should specifically assess memory and include repeated assessments. Potential secondary outcomes could include self- and observer-rated health-related quality of life and global impressions of change in lieu of activities of daily living. Onset of dementia should not be an endpoint because many patients would be on the cusp of dementia and dementia onset is influenced by numerous biological and environmental factors. Inferences that can be made from trials results will likely involve the effects of the test drug on memory and self-rated global function. Disease modification is not likely to be inferred except in trials over two years in duration in which a change in a biomarker can be used as an adjunctive assessment. Models and simulations using existing clinical trials databases would be helpful in planning early AD trials.
Solving Zadeh's Magnus challenge problem on linguistic probabilities via Linguistic Weighted Averages

In this paper, we present a solution to Zadeh's Magnus challenge problem on linguistic probabilities. First, we implement Zadeh's solution to this problem. Then, we use the intersection-product syllogism and a syllogism based on the entailment principle to interpret the problem so that it can be solved via Linguistic Weighted Averages. We show that the problem can be solved by calculation of pessimistic (lower) and optimistic (upper) probabilities via Linguistic Weighted Averages. Then, we choose vocabularies for quantifiers and linguistic probabilities that are involved in the problem statement. The vocabularies are modeled using interval type-2 fuzzy sets. We calculate optimistic (upper) and pessimistic (lower) probabilities, which naturally would be interval type-2 fuzzy sets. Finally, we map the pessimistic and optimistic probabilities to linguistic probabilities present in the vocabularies, so that the results can be comprehended by a human.
MEASUREMENTS OF HYPERGOLIC FUELS' AND OXIDANTS' PERMEATION THROUGH COMMERCIAL PROTECTIVE MATERIALS—PART II: NITROGEN TETROXIDE, MONOMETHYLHYDRAZINE, AND ANHYDROUS HYDRAZINE

Forty materials were tested to determine their relative resistance to permeation by nitrogen dioxide (NO2), monomethylhydrazine (MMH), and hydrazine (Hz) after exposure to the liquid hypergolic propellants dinitrogen tetroxide (N2O4), MMH, and anhydrous hydrazine (AHz), respectively. A new piece of material was used in each test. The materials were not preconditioned, nor was exposure to the hypergolic propellants repeated. In these tests, the materials were clamped in a static test cell that permitted one side of the fabric to be exposed to the oxidant or fuels, while the other side of the fabric was monitored for NO2, MMH, or Hz concentrations with an electrochemical analyzer. Breakthrough times were calculated for predefined “breakthrough” concentrations of 0.3 ppm NO2, 16 ppb MMH, or 16 ppb Hz and saturation concentrations of 1.8 ppm NO2, 1.6 ppm MMH, or 1.6 ppm Hz. These breakthrough times were tabulated for several samples of each material used in the tests. The materials tested were candidates for ...
Elevated concentrations of plasma omega-3 polyunsaturated fatty acids among Alaskan Eskimos.

Eskimos living in rural southwestern Alaska depend on fish and marine mammals as major sources of subsis- tence food. Fatty acid concentrations in 80 Yupik Eskimos living in either a coastal or river village of southwestern Alaska were compared with those of non-Native control subjects. Concentra- tions of total plasma w-3 fatty acids, eicosapentaenoic acid (20:5w-3), and docosahexaenoic acid (22:6w-3) were 4.3, 13, and 6.8 times higher, respectively, in Native participants than in non- Native control subjects. Concentrations of these fatty acids were higher in coastal-village than in river-village participants; con- centmations paralleled consumption of marine mammal oil and marine fish. The ratios of eicosapentaenoic to amachidonic acid for adult coastal- and river-village participants were 1. 16 and 0.70, respectively, 14 and 9 times those of non-Native adults, respectively. There was no increase in the mean bleeding times of Native participants of either village. Am J Clin Nutr 1994;59:384-8.
Base- and acid-catalyzed interconversions of O-acyl- and N-acyl-ethanolamines: a cautionary note for lipid analyses

The isolation and quantification of ethanolamine containing lipids from animal tissues may expose neutral lipid extracts to acidic or basic conditions during chromatographic separations or derivatization chemistry. While investigating the acid- and base-catalyzed production of anandamide in chromatographic fractions of rat brain extracts not containing anandamide, we observed that O,N-acyl migrations are facile. O,N-acyl migrations are well documented in synthetic organic chemistry literature, but are not well described or recognized with regard to methods in lipid isolation or lipid enzyme studies. We report here the synthesis and characterization of O- and N-acyl (palmitoyl- or arachidonoyl-)ethanolamines. Their rearrangements in base and acid are quantified by liquid chromatography;-electrospray ionization mass spectrometry. The rearrangements proceed through a cyclic intermediate that is also formed during chemical reactions commonly used for derivatization of acylethanolamines for gas chromatography-mass spectrometry. The isolation and characterization of N- or O-acylethanolamines and their enzymatic formation requires awareness and consideration of the proclivity of these compounds to chemically rearrange.
Cyberactivism Amongst Marriage Equality Protesters

This paper explores how the digital revolution has transformed the activism of participants in marriage equality rallies targeting the Supreme Court hearings for same-sex marriage. The internet and social media have become valuable as a source of information about movement-related issues, as a recruitment tool for offline activism, and as a venue for online activism, and cyberactivism is an increasingly prominent tactic in the repertoire used by social justice organizers (Carty and Onyett 2006; Gaby and Caren 2012). According to Van Laer (2010), protesters who obtain information about demonstrations online are more likely to be superactivists who are involved in multiple movements simultaneously, have past protest experience, have stronger movement-related grievances, have higher political interest, are younger, and are better educated. Much of the previous scholarship focuses on the internet (and not necessarily on social media), and either examines the internet as a protest information source or as a venue for activism. This paper suggests that the internet and social media both need to be examined as a protest information source and as a venue for activism and thus investigates how using the internet or social media as a protest information source influences the odds that protesters have engaged in cyberactivism using the internet or social media in the past year. Other factors that will be examined include the demonstrators’ involvement in past protests concerning LGBTQIA rights or marriage equality, attitudes about same-sex marriage, identifying as LGBTQIA or having contact with LGBTQIA family or friends, sense of protest efficacy, political interest, partisanship, age, and education. The paper analyzes data from 516 surveys (385 on-site and 131 online) of participants in March 2013 marriage equality rallies targeting the U.S. Supreme Court hearings regarding the Defense of Marriage Act and Proposition 8. Participants in the marriage equality rallies were indeed highly engaged in political activism, and over half the participants are involved in activism using social media or the internet. Social media was the most important source of information concerning the protest. Regression analysis of marriage equality protesters’ cyberactivism will be used to explore the impact of various causal factors on the odds that protesters have used the internet or social media for activism in the past year.
Contributions of planned readmissions and patient comorbidities to high readmission rates in vascular surgery patients.

Objective Administrative data show that among surgical patients, readmission rates are highest in vascular surgery. Herein we analyze the contribution of planned readmissions and patient comorbidities to high readmission rates in vascular surgery. Methods The 2012 to 2014 American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) data set was analyzed for overall and unplanned readmissions. Bivariable and multivariable risk adjustment analyses were performed using patient comorbidities to compare risks of overall and unplanned readmissions in vascular surgery compared with other specialties. Results Among 1,164,421 surgical patients, 86,403 underwent a vascular operation (other specialties included general surgery, 587,829 [51%]; orthopedic surgery, 211,507 [18%]; gynecology, 82,771 [7%]; urology, 62,153 [5%]; neurosurgery, 55,030 [4.7%]; plastic surgery, 32,318 [3%]; otolaryngology, 31,070 [2.6%]; and thoracic surgery, 15,340 [1%]). Incidence of 30-day readmission was 10.2% for vascular and 5.5% for other specialties ( P P P P P P P = .13). Conclusions Incidence of 30-day readmission after vascular surgery appears high, but after account for planned readmissions and risk adjustment, the risk of unplanned readmission is similar to that in other surgical patients. Thus, the use of readmission rate as a quality measure must account for more frequent planned vascular readmissions and patient-specific differences between vascular surgery and other specialties.
Asian American Civic Participation: The Civic ‘Model Minority’?

Asian Americans are one of the fastest-growing non-white U.S. racial groups, and they often have a public image as “model minorities,” inherently predisposed to achieve educational and economic success. Scholars have largely dispelled the model minority image. Yet, many Asian Americans, although certainly not all, do achieve high education and income. For other groups of Americans, civic participation tends to increase as education and income increase. In this context, asking the extent to which Asian Americans participate in American civic life is important for understanding both the future of American civil society and the future of Asian America.
Bis(acetylacetonate) Tungsten(IV) Complexes Containing a π-Basic Diazoalkane or Oxo Ligand

Tungsten(IV) bis(acetylacetonate) (acetylacetonate = acac) complexes were synthesized by incorporating either a diazoalkane or an oxo ligand into the coordination sphere of a tungsten(II) reagent. The reaction of free diazoalkane (N2CRR′) with W(CO)3(acac)2 leads to loss of two carbon monoxide ligands and coordination of the diazoalkane reagent through the terminal nitrogen to produce W(CO)(acac)2(N2CRR′). This monomer is best formulated as a tungsten(IV) complex. A second example of converting a d4 tungsten carbonyl complex to a d2 product involves oxidation of W(CO)(acac)2(PhC≡N) with m-chloroperoxybenzoic acid (MCPBA) to replace the CO ligand with an oxygen atom. This increase in metal oxidation state causes rotation of the nitrile ligand by 90° relative to the two bidentate acac ligands. Electrophilic addition at the nitrogen of the π-bound nitrile ligand using methyl triflate (MeOTf) and subsequent nucleophilic addition at carbon with sodium trimethoxyborohydride, Na[HB(OMe)3], reduces the C≡N bond s...
Assessing mobile satellite systems using a cost per billable minute metric

The cost per billable minute is the metric to compare the efficiency of different mobile satellite system architectures. The cost per billable minute to achieve an internal rate of return is determined from estimates of the useful system capacity and life cycle costs. To evaluate the useful system capacity, a computer simulation was developed to model the complex interaction between satellites, gateways, capacity limits, and an expected market model. The major capacity-limiting factors addressed include frequency reuse, constellation design, link availability, spot beam patterns, multiple access schemes, and satellite power. The life cycle costs were estimated for the satellites, launch vehicles, gateways, public-switched telephone network hardware connections, operations, and launch insurance. The metric is evaluated for five model systems in low, medium, and GEOs to demonstrate the usefulness of the metric in the system engineering design process. (Author)
Germanium Telluride (GeTe) phase change resistors for reconfigurable circuit applications

In this paper, we report on the electrical properties of the phase change (PC) material, Germanium Telluride (GeTe), and discuss the fabrication and testing of GeTe resistors. Vertical and horizontal GeTe resistors are fabricated and tested through resistance measurements before and after substrate heating and joule heating performed by voltage pulsing. Resistance changes of six orders of magnitude and four orders of magnitude are demonstrated by substrate heating and voltage pulsing, respectively. The horizontal resistor designs are shown to be impractical for low voltage applications due to the their large inter-electrode distances. Various sizes of GeTe resistors ranging from 15×15×0.4 μm3 to 3×3×0.09 μm3 are tested and a relationship is demonstrated between GeTe resistor length and the threshold voltage pulse required for phase change.