cssi/SciSciGPT-SciSciNet huggingface dataset:
Multimedia: asynchronous distributed education—a review and case study

Interest in and delivery of distributed education has increased rapidly in the past decade. Technology brings the promise of creating superior learning environments relative to the traditional classroom as well as delivering these learning experiences to greater numbers and more diverse audiences. However, successful creation and delivery of distributed courses requires new dimensions in thought and creativity because a direct translation from classroom to computer will not enhance the learning experience. To make distributed education work, instructors have to rethink their role as teacher, and students must take charge of their own learning experience. Many accommodations must be made in distributed course creation to ensure a student-centered environment that overcomes the feeling of isolation. The authors discuss these themes in relation to their experiences in delivering an asynchronous distributed introductory course at the University of Arizona.
Measurement of the Dresselhaus and Rashba Spin-Orbit Coupling Via Weak Anti-Localization in InSb Quantum Wells

Weak anti-localization has been observed in the magneto-resistance of both symmetrically and asymmetrically doped InSb/AlInSb quantum wells. We find that for both types of structures, the magnetic field corresponding to the conductance minimum is in good agreement with the dominant spin-orbit term, which is the cubic Dresselhaus and Rashba terms for symmetric and asymmetric samples, respectively.
Exploring management of arrival spacing using route extensions with terminal spacing tools

Airports with shared runway operations between arrivals and departures can experience severe departure gridlock and delays during a heavy arrival push due to insufficient gaps in the arrival stream for aircraft to depart. The problem is accentuated in situations when a large gap in the arrival spacing has to be created at the last minute due to wake vortex separation requirements. At LaGuardia airport, wake vortex separation problems arise when a heavy jet, such as a B757, departing on Runway 31 needs additional spacing between arrivals on Runway 22. A standard solution for controllers in many airports in situations such as this is to extend the downwind leg of arrival aircraft to create extra space between the arrivals. The question addressed in this paper is how such route extensions would work with terminal scheduling operations, namely (1) the Terminal Sequencing and Spacing (TSS) tools and (2) a new scheduling tool which increases the availability of gaps for departure aircraft—Departure Sensitive Arrival Spacing (DSAS). In a simulated LaGuardia airport (LGA) Terminal Radar Approach Control (TRACON) airspace, two new RNAV arrival routes were created along with extensions to these routes. The arrival route from the south had a downwind leg extension near the airport in the final sector. The arrival route from the north had an extension in a feeder sector further from the airport. An exploratory one-hour run with the route extensions was compared to an hour run without the extensions. Topics included in this paper are 1) how the route extensions were developed, 2) a procedure outlining how the aircraft could be scheduled to the extensions and who would do it, and 3) the results of the exploratory run compared to the original run without the extensions. The results indicated that the extended downwind leg route helped to create a B757 departure gap in the middle of a packed arrival stream, resulting in a reduction of 11 minutes in average wait time for the B757s, but at a cost of increased controller self-reported workload from low to moderate.
Dual active bridge converter with PWM control for solid state transformer application

For the single-phase, dual active bridge converter (DAB) based three-stage solid state transformer (SST), the instantaneous load power seen by the DAB converter varies from zero to twice the load average power at double-line frequency. Traditionally with phase-shift modulation (PSM) control, large DC link capacitors are needed to handle the instantaneous load power variation while DAB converter only processes the constant power resulting in better soft-switching range and consequently high efficiency. However, the large electrolytic capacitors required in the DC link adversely affect the power density and the reliability of SST. In this paper, a PWM control is applied to minimize the DC link capacitor for the DAB based three-stage SST. The experimental results prove that DAB converter with PWM control has extended ZVS range down to nearly zero load and therefore improved efficiency at light load. Consequently, DAB can achieve comparable high efficiency while the DC link capacitors of SST can be reduced to a value low enough for film capacitor implementation.
Summer Sunburn and Sun Exposure Among US Youths Ages 11 to 18: National Prevalence and Associated Factors

Objective. Epidemiologic evidence suggests that ultraviolet radiation (UVR), from sun exposure and sunburns during early life, is associated with increased risk of melanoma and other skin cancers in adulthood. The objective of this study was to gather national, population-based data on sun exposure and protection behaviors among US youths ages 11 to 18 to quantify the magnitude and patterns of sun exposure and establish baselines for continued surveillance. Methods. A nationwide survey based on random-digit dialing and stratified, 2-stage national probability sampling was conducted of households with telephones in the 48 contiguous states of the United States during July through October of 1998; a population-based sample of 1192 youth ages 11 to 18 was studied to measure weighted prevalence estimates of summer sunburn and sun exposure and adjusted prevalence odds ratios and 95% confidence intervals from logistic regression analyses of sunburn. Results. Among youths ages 11 to 18, 72% reported having had at least 1 summer sunburn, 30% reported at least 3, and 12% reported at least 5 sunburns. Before receiving their most serious summer sunburn, 39% of youths reported having applied sunscreen. Factors associated with increased odds of sunburn included greater sun sensitivity, white race, age younger than 16 years, more hours spent outdoors, and high desirability of a tan. Conclusions. Summer sunburn was the norm among US youths ages 11 to 18. The high frequency of sunscreen use during the sunburning episodes suggests the need to educate youth and parents better about proper use of these agents, as well as the importance of practicing other sun protection behaviors, such as wearing hats and protective clothing and avoiding the sun during peak exposure times. These data may serve as a baseline for tracking progress in skin cancer prevention efforts and will inform the crafting of future public health campaigns.
Processes controlling the rapid drainage of two ice-rich permafrost-dammed lakes in NW Canada

This paper considers the processes controlling the rapid drainage of ice-rich permafrost-dammed lakes. It is postulated that the primary process controlling lake drainage is the melting of ice-rich permafrost, in a manner similar to that controlling the drainage of glacier-dammed lakes. Two lakes are considered in the analysis: one that drained naturally over a period of less than 16 h, and Lake Illisarvik, which was experimentally drained in 1978. Preliminary analysis showed that the energy contained in the lake water was sufficient for melting the ice content of the resulting drainage channel for both study lakes. Discharge estimated using a glacier-dammed lake model developed by Clarke (Journal of Glaciology 1982; 28: 3) compared reasonably well with measured discharge during the period of rapid channel enlargement at Illisarvik, and resulted in the draining of Trail Valley Creek lake within the brief period indicated by a gauging station. These results suggest that melting of the ice-rich permafrost during drainage dominates at least the early stages of drainage. However, further work is required to consider the processes of mechanical erosion, which in some cases may dominate the later stages of drainage, and to consider the appropriateness of certain assumptions in the lake drainage model. Copyright © Environment Canada 2001 Reproduced with Permission of Environment Canada.
An error analysis of a finite element method for a system of nonlinear advection--diffusion--reaction equations

In this paper we present an analysis of a finite element method for solving a system of nonlinear advection-diffusion-reaction equations. We prove the existence and uniqueness of the numerical solution, and obtain a prior error estimates optimal in H^1 norm. Numerical computations are carried out to test the order of accuracy in the error estimates. Blend function interpolations are applied in the calculation of numerical integrations over elements with a curved boundary.
Linear operators on Clifford algebras

The linear operators from a finite-dimensional Clifford algebra to itself are computed in terms of suitable two-sided multiplications and operations on the center.
Immigrant Incorporation in an Era of Weak Civic Institutions: Immigrant Civic and Political Participation in the United States

In this article, the author analyzes five domains of immigrant incorporation and participation in the United States—civic and community engagement among immigrants; naturalization patterns; immigrant (and co-ethnic) partisanship and electoral behaviors; the election of naturalized citizens, and their U.S.-born co-ethnics, as elective officeholders; and immigrant transnational efforts to influence the civic or political life of their communities or countries of origin—in an effort to highlight both the opportunities immigrants and naturalized citizens have seized in U.S. politics and the barriers, particularly, institutional barriers, they continue to face. Although the primary analytical focus is immigrants in the United States, the author is attentive to the challenge raised by Irene Bloemraad (2011 [this issue]) in her introductory article to identify opportunities for comparative insights from the Canadian case. As will be evident, the author ultimately identifies more apples and oranges in the compari...
Longitudinal study of the impacts of land cover change on hydrologic response in four mesoscale watersheds in New York State, USA

In humid, temperate regions, there remains limited direct evidence of the influence of land cover changes on hydrologic response (e.g. storm event discharge volume), especially across larger watersheds. Using historic aerial photography dating back to the 1930s in conjunction with long-term stream gaging data, we assessed the role of land cover change on hydrologic response over multi-decadal periods in four mesoscale watersheds in New York State. All four watersheds had increases in forest cover accompanied by small increases in urban land cover. Using a relatively novel methodology for land cover change studies, hydrologic response was evaluated by establishing an empirical function relating precipitation, watershed wetness, and discharge for each era of distinct land cover. This function was then used to estimate discharge for fixed precipitation amounts and wetness levels, allowing weather variables to be controlled across eras. One watershed (Limestone Creek) exhibited virtually no change in hydrologic response despite forest cover increasing by over 100%. One watershed (Fall Creek) exhibited a slight increase in hydrologic response with a greater than 100% increase in forest cover. The two other watersheds exhibited a greater than 20% decrease in hydrologic response, but we speculate the changes in these two watersheds were in part due to the construction of numerous small dams (Wappinger Creek) and a possible loss of riparian wetlands (Sterling Creek). This work demonstrates that the effects of land cover on hydrologic response are not always consistent with standard hydrologic intuition (i.e. increasing forested land does not always reduce storm event discharge volumes) and that often other factors may be more important than basic land cover in controlling hydrologic response.
ACID-BASE AND ELECTROCHEMICAL PROPERTIES OF THE MLCT EXCITED STATES AND ONE-ELECTRON-REDUCED FORMS OF RUTHENIUM(II) COMPLEXES CONTAINING 2-(2'-PYRIDYL )PYRIMIDINE AND 2,2'-BIPYRIDINE IN AQUEOUS SOLUTION

The acid−base and electrochemical properties of the MLCT excited states and the one-electron-reduced forms of the three Ru(bpy)3-p(pypm)p2+ complexes, where bpy = 2,2‘-bipyridine, pypm = 2-(2‘-pyridyl)pyrimidine, and p = 1−3, have been examined in aqueous solution; a determination has been made of the ground- and excited-state electrochemical potentials, the values of the pKa and deprotonation rate constants of the conjugate acids of the excited states and the one-electron-reduced complexes, and the kinetics of the second-order decays of the reduced species. Comparison is made with the behavior of the analogous 10 complexes of the form Ru(bpy)3-m-z(bpm)m(bpz)z2+, where bpm = 2,2‘-bipyrimidine, bpz = 2,2‘-bipyrazine, m and z = 0−3, and m + z ≤ 3, which have been studied in detail before.
Pharmacokinetics of Haloperidol

Haloperidol has been used extensively for the treatment of psychotic disorders, and it has been suggested that the monitoring of plasma haloperidol concentration is clinically useful. Different assay methodologies have been used in research and clinical practice to examine the relationship between response and plasma concentration of the drug. Chemical assays such as high pressure liquid chromatography (HPLC) and gas-liquid chromatography (GLC) have good precision and sensitivity; radioimmunoassay (RIA) is generally more sensitive, but less precise and specific. Radioreceptor assay quantifies dopaminereceptor blocking activity but does not provide results comparable with those of HPLC, GLC and RIA. Large doses of haloperidol can safely be given intravenously and intramuscularly for rapid neuroleptisation; the bioavailability of this agent administered orally ranges from 60 to 65%. However, there is large interindividual, but not intraindividual, variability in plasma haloperidol concentrations and most pharmacokinetic parameters. This interindividual variability could be partially explained by the reversible oxidation/reduction metabolic pathway of haloperidol: it is metabolised via reduction to reduced haloperidol, which is biologically inactive. Different extents of enterohepatic recycling, and ethnic differences in metabolism, could also account for the observed variability in haloperidol disposition. Although not conclusive from different clinical studies, it appears that a plasma haloperidol concentration range of 4 micrograms/L to an upper limit of 20 to 25 micrograms/L produces therapeutic response. The role of reduced haloperidol in determining clinical response is not clear, although in some studies a high reduced haloperidol/haloperidol concentration ratio has been suggested to be associated with therapeutic failure. Measurements of red blood cell or cerebrospinal fluid haloperidol concentration have also been proposed as determinants of therapeutic response, but results from different studies are inconsistent, and do not seem to provide a significant advantage over plasma concentration monitoring. Physiological parameters such as prolactin and homovanillic acid levels have been evaluated, with the latter showing some promise that warrants further investigation. Haloperidol decanoate can be characterised by a flip-flop pharmacokinetic model because its absorption rate constant is slower than the elimination rate constant. Its plasma concentration peaks on day 7 after intramuscular injection. The elimination half-life is about 3 weeks, and the time to steady-state is about 3 months.
Strong representations for LAD estimators in linear models

Consider the standard linear modely i =z i β+e i ,i=1, 2,...,n, where zi denotes theith row of ann x p design matrix,β∈ℝ p is an unknown parameter to be estimated ande i are independent random variables with a common distribution functionF. The least absolute deviation (LAD) estimate $$\tilde \beta $$ of β is defined as any solution of the minimization problem $$\sum\limits_{i = 1}^n { \left| {y_i - z_i \tilde \beta } \right| = \inf \left\{ {\sum\limits_{i = 1}^n { \left| {y_i - z_i \beta } \right|:\beta \in \mathbb{R}^p } } \right\}} .$$ In this paper Bahadur type representations are obtained for $$\tilde \beta $$ under very mild conditions onF near zero and onz i,i=1,...,n. These results are extended to the case, when {e i} is a mixing sequence. In particular the results are applicable when the residualse i form a simple autoregressive process.
The Effect of Subsidized Housing on Values of Adjacent Housing

This is a case study of the effect of subsidized housing on the value of adjacent non-subsidized housing. Four townhouse clusters in Fairfax County, Virginia, were selected for study because of the high degree of homogeneity between clusters. The clusters are all in the same community but vary in distance from subsidized housing. Sale prices were analyzed using a regression model which included distance from subsidized housing as an independent variable. Based on the results of the regression analysis, the authors conclude that the subsidized housing had a negative impact on the values of adjacent properties.
Renal segmentation in physiological feature space with dynamic contrast enhanced MR Urography: preliminary research

The kidney is composed of many structurally and functionally different tissues. These functionally distinct tissues exhibit different magnetic resonance signal characteristics in typical MR Urography. This work exploits the tissue functional differences to construct a physiological feature space for renal segmentation, which has the more distinct meaning for directly functional evaluation, and lower requirements for storage and computation. In this preliminary research, a segmentation method was developed and investigated to demonstrate its feasibility on images obtained using a typical MR Urograpy protocol.
Unsteady thermal response of the condensed-phase fuel adjacent to a reacting gaseous boundary layer

This paper investigates the burning-rate response of a condensed-phase fuel plate adjacent to a reacting gaseous boundary layer, where the external flow has a longitudinal oscillation. The purpose is to simulate the unsteady droplet burning in a liquid-propellant rocket and to try to isolate a physical mechanism which leads to instability. The nonsteady process treated here is the heat transfer in the condensed phase. The results show that the velocity-sensitive responses exhibit resonant phenomena at the proper frequency range, and indicate that, in favorable conditions, a liquid-propellant rocket can be driven to instability because of the thermal lag in the droplets. Experiments to test this theory, and remedies to this type of instability, are suggested.
Protein electron transfer (mechanism and reproductive toxicity): Iminium, hydrogen bonding, homoconjugation, amino acid side chains (redox and charged), and cell signaling

This contribution presents novel biochemical perspectives of protein electron transfer (ET) with focus on the iminium nature of the peptide link, along with relationships to reproductive toxicity. The favorable influence of hydrogen bonding on protein ET has been widely documented. Hydrogen bonding of the zwitterionic peptide enhances iminium character. A wide array of such bonding agents is available in vivo, with many reports on the peptide link itself. ET proceeds along the backbone, due in part, to homoconjugation. Redox amino acids (AAs), mainly tyrosine (Tyr), tryptophan (Typ), histidine (His), cysteine (Cys), disulfide, and methionine (Met), are involved in the competing processes for radical formation: direct hydrogen atom abstraction versus electron and proton loss. It appears that the radical or radical cation generated during the redox process is capable of interacting with n-electrons of the backbone. Beneficial effects of cationic AAs impact the conduction process. A relationship apparently exists involving cell signaling, protein conduction, and radicals or electrons. In addition, the link between protein ET and reproductive toxicity is examined. A key element is the role of reactive oxygen species (ROS) generated by protein ET. There is extensive evidence for involvement of ROS in generation of birth defects. The radical species arise in protein mainly by ET transformations by enzymes, as illustrated in the case of alcoholism.
Does consumption of beer, alcohol, and bitter substances affect bitterness perception?

The relation between consumption of beer, alcohol, and bitter substances was investigated by comparing 20 each of male adults, low users ( 3.6 l/week) of beer for sensitivity to and like/dislike for the bitterness of isohumulones. Intake of beer, alcohol, and bitter substances was measured with a food frequency questionnaire and a 14-day recall journal. Intake of alcohol (including alcohol from sources other than beer) and bitter substances was higher for high users of beer than for low users. The average bitterness units (BUs) in the beers consumed by the two groups did not differ, indicating that high users do not consume more bitter beers than low users. Detection thresholds for isohumulones in water did not differ between the two groups, but high users had higher difference thresholds for isohumulones in beer (p < 0.10). In time-intensity measurements of bitterness in beer, low users of beer recorded significantly higher maximum intensities (p < 0.001) and shorter total durations (p < 0.001) than high users, with no difference between the two groups for time to maximum intensity and area under the TI curve. There was no significant difference between the two groups for BUs of beers produced by ad lib mixing of low- and high-bitterness beers, or for mean hedonic ratings of various concentrations of isohumulones in beer. These results suggest that intakes of beer, alcohol, and bitter substances are not major determinants of taste responses to the bitterness of isohumulones.
Eruption rates and compositional trends at Los Humeros Volcanic Center, Puebla, Mexico

The Los Humeros volcanic center, located 180 km east of Mexico City, is one of several Pleistocene silicic centers in the “back arc” portion of the Mexican Neovolcanic Belt. The eruptive history at Los Humeros suggests that average eruptive rates increased with time and exceeded rates of regeneration of differentiated magma. Silicic volcanism began ∼0.47 Ma ago with extrusion of high-silica rhyolite domes. Shortly thereafter, at 0.46 Ma ago, 115 km3 of magma zoned from high-silica rhyolite to rhyodacite were erupted, resulting in formation of the Xaltipan Ignimbrite and collapse of the 21×15 km Los Humeros caldera. High-silica rhyolite domes then erupted along the northwestern ring-fracture zone of the caldera. They are covered by the Faby Tuff, a dominantly rhyodacitic sequence of plinian fall deposits erupted from the southeast quadrant of the Los Humeros caldera, dated at 0.24 Ma. A second major caldera-forming event occurred ∼0.1 Ma ago with the eruption of the Zaragoza Tuff, a nonwelded ignimbrite zoned from rhyodacite to andesite. Eruption of these 12 km3 of magma led to collapse of the 10-km-diameter Los Potreros caldera, which is nested within the older Los Humeros caldera. Between 0.04 and 0.03 Ma ago, an arc of andesitic scoria cones, concentrated along the southern ring-fracture zone of the Los Humeros caldera, fed lavas that flowed southward from the volcanic center, and andesite lavas built two small shields between the eastern rims of the two calderas. Approximately 6 km of andesitic magma were extruded during this stage. Activity continued up to 0.02 Ma ago with eruption of 10 km3 of rhyodacitic to andesitic lava flows from centers near the northern margin of the Los Potreros caldera, in the area between the eastern rims of the two calderas, and within a broad band where the southern segments of the inferred Los Humeros and Los Potreros ring-fracture zones nearly coincide. Simultaneous venting of rhyodacitic and andesitic tephra within this band led to formation of the 1.7-km-diameter El Xalapazco caldera. Minor fault-bounded uplift of the southeastern quadrant of the Los Potreros caldera followed. The latest stage of volcanic activity is represented by the eruption of ∼0.25 km3 of olivine basalt lavas along the southern ring-fracture zone of the Los Humeros caldera and on the floors of the Los Potreros and El Xalapazco calderas. Erupted magmas show an overall trend with time toward more mafic compositions. Volumetric eruptive rates increased from ∼0.06 km3 per thousand years 0.25 Ma ago to ∼0.2 km3 per thousand years in the last 0.1 Ma. The increase in eruptive rate may have been the result of a progressive decrease in the structural integrity of the roof zone of the system as successive caldera-forming eruptions reactivated old zones of weakness and created new ones. An increasingly disrupted roof allowed mafic and intermediate magmas to reach the surface relatively rapidly, decreasing their residence time in a high-level chamber and thus the time available for their differentiation
Laryngeal transplantation: A program for investigating new parameters

Laryngeal transplantation was actively investigated in the late 1960s and early 1970s using a dog model. An expanded knowledge base in immunobiology, pharmacology, and deglutition makes reassessment timely after an approximately 20-year hiatus. The basic parameters to be evaluated include varied methods of preservation, optimal immunosuppressive drug regimens, and the role of radiation therapy. Our current research protocol addressing the latter considerations is outlined, including a brief introduction of a new animal model developed specifically for this purpose. We will ultimately attempt to answer the question: Is laryngeal transplantation feasible?
Transition management for reconfigurable hybrid control systems

This article presents a framework for managing transitions between discrete states in hybrid control systems. Based on a study of how hybrid controls are designed and implemented, the authors have identified generic software patterns that are customizable yet can transparently handle common needs for component integration and reconfiguration.
Recent results in high pT physics from CDF

We present the most recent high p T results from the CDF experiment using $p\overline{p}$ collisions at $\sqrt{s}=1.96~$ TeV produced at the Tevatron Collider at Fermilab. We will summarize results in electroweak physics, top physics and searches for physics beyond the Standard Model. Many of the measurements of important signals like W boson, Z boson, and the top quark have been reestablished. Taking advantage of the increase in energy and detector upgrades, these measurements are already beginning to be competitive with previous results.
Bioengineered three-layered robust and elastic artery using hemodynamically-equivalent pulsatile bioreactor.

Background— There is an essential demand for tissue engineered autologous small-diameter vascular graft, which can function in arterial high pressure and flow circulation. We investigated the potential to engineer a three-layered robust and elastic artery using a novel hemodynamically-equivalent pulsatile bioreactor. Methods and Results— Endothelial cells (ECs), smooth muscle cells (SMCs), and fibroblasts were harvested from bovine aorta. A polyglycolic acid (PGA) sheet and a polycaprolactone sheet seeded with SMCs, and a PGA sheet seeded with fibroblast, were wrapped in turn on a 6-mm diameter silicone tube and incubated in culture medium for 30 days. The supporting tube was removed, and the lumen was seeded with ECs and incubated for another 2 days. The pulsatile bioreactor culture, under regulated gradual increase in flow and pressure from 0.2 (0.5/0) L/min and 20 (40/15) mm Hg to 0.6 (1.4/0.2) L/min and 100 (120/80) mm Hg, was performed for an additional 2 weeks (n=10). The engineered vessels acquired distinctly similar appearance and elasticity as native arteries. Scanning electron microscopic examination and Von Willebrand factor staining demonstrated the presence of ECs spread over the lumen. Elastica Van Gieson and Masson Tricrome Stain revealed ample production of elastin and collagen in the engineered grafts. Alpha-SMA and calponin staining showed the presence of SMCs. Tensile tests demonstrated that engineered vessels acquired equivalent ultimate strength and similar elastic characteristics as native arteries (Ultimate Strength of Native: 882±133 kPa, Engineered: 827±155 kPa, each n=8). Conclusions— A robust and elastic small-diameter artery was engineered from three types of vascular cells using the physiological pulsatile bioreactor.
The stochastic geometry of invasion percolation

Invasion percolation, a recently introduced stochastic growth model, is analyzed and compared to the critical behavior of standardd-dimensional Bernoulli percolation. Various functions which measure the distribution of values accepted into the dynamically growing invaded region are studied. The empirical distribution of values accepted is shown to be asymptotically unity above the half-space threshold and linear below the point at which the expected cluster size diverges for the associated Bernoulli problem. An acceptance profile is defined and shown to have corresponding behavior. Quantities related to the geometry of the invaded region are studied, including the surface to volume ratio and the volume fraction. The former is shown to have upper and lower bounds in terms of the above defined critical points, and the latter is bounded above by the probability of connection to infinity at the half-space threshold. Provided that the critical regimes of Bernoulli percolation possess their anticipated properties, as is known to be the case in two dimensions, these results verify numerical predictions on the acceptance profile, establish the existence of a sharp surface to volume ratio and show that the invaded region has zero volume fraction. Large-time asymptotics are analyzed in terms of the probability that the invaded region accepts a value greater thanx at timen. This quantity is shown to be bounded below byh(x)exp[−c(x)n(d-1)/d] forx above threshold, and to have an upper bound of the same form forx larger than a particular value (which coincides with the threshold ind=2). For two dimensions, it is also established that the infinite-time invaded region is essentially independent of initial conditions.
Radiative capture of 3He by 7Li from 3 to 6 MeV

Abstract The reaction 7 Li( 3 He,γ) 10 B has been studied in the energy range 3.0 MeV ≦ E 3 He ≦6.0 MeV, using an anticoncoincidence-shielded NaI(Tl) gamma-ray detector. Excitation functions for capture radiation to the ground and first four excited states of 10 B were measured with the detector at 90° to the incident beam direction. A strong resonance at E 3 He = 3.40 MeV with a c.m. width of 910 keV was found in the cross section for capture to the 2 + ( T = 0), 3.59 MeV state of 10 B. Angular distribution measurements indicate s-wave capture; the resonant state can be given the spin and parity assignment 1 − or 2 − ( T =1) with 2 − being more likely. The compound nucleus mechanism appears to dominate the capture process below 6 MeV bombarding energy.
90-mm/18.8-T All-HTS Insert Magnet for 1.3 GHz LTS/HTS NMR Application: Magnet Design and Double-Pancake Coil Fabrication

This paper deals with the latest design of an all High Temperature Superconductor (HTS) insert for our 1.3 GHz NMR program. Due to a loss of our original 600 MHz HTS insert, the entire program was revised, and upon further examination of the options available for the HTS insert, which included not only conductor material properties, but also new winding technologies recently developed here at the FBML, it has finally been decided to build an 800 MHz (H800) insert purely based in SuperPower YBCO conductor. The new H800 will still be comprised of nested stacks of double-pancake coils and will run in the background of a 500 MHz LTS NMR magnet already available at FBML. We present here electromagnetic and mechanical details of the H800 design, winding technique employed, and testing of individual coils.
Review of surgical robotics user interface: what is the best way to control robotic surgery?

As surgical robots begin to occupy a larger place in operating rooms around the world, continued innovation is necessary to improve our outcomes. A comprehensive review of current surgical robotic user interfaces was performed to describe the modern surgical platforms, identify the benefits, and address the issues of feedback and limitations of visualization. Most robots currently used in surgery employ a master/slave relationship, with the surgeon seated at a work-console, manipulating the master system and visualizing the operation on a video screen. Although enormous strides have been made to advance current technology to the point of clinical use, limitations still exist. A lack of haptic feedback to the surgeon and the inability of the surgeon to be stationed at the operating table are the most notable examples. The future of robotic surgery sees a marked increase in the visualization technologies used in the operating room, as well as in the robots’ abilities to convey haptic feedback to the surgeon. This will allow unparalleled sensation for the surgeon and almost eliminate inadvertent tissue contact and injury. A novel design for a user interface will allow the surgeon to have access to the patient bedside, remaining sterile throughout the procedure, employ a head-mounted three-dimensional visualization system, and allow the most intuitive master manipulation of the slave robot to date.
P53-independent expression of p21Cip1 in muscle and other terminally differentiating cells

Terminal differentiation is coupled to withdrawal from the cell cycle. The cyclin-dependent kinase inhibitor (CKI) p21Cip1 is transcriptionally regulated by p53 and can induce growth arrest. CKIs are therefore potential mediators of developmental control of cell proliferation. The expression pattern of mouse p21 correlated with terminal differentiation of multiple cell lineages including skeletal muscle, cartilage, skin, and nasal epithelium in a p53-independent manner. Although the muscle-specific transcription factor MyoD is sufficient to activate p21 expression in 10T1/2 cells, p21 was expressed in myogenic cells of mice lacking the genes encoding MyoD and myogenin, demonstrating that p21 expression does not require these transcription factors. The p21 protein may function during development as an inducible growth inhibitor that contributes to cell cycle exit and differentiation.
Entropy of self-gravitating radiation

We examine the entropy of self-gravitating radiation confined to a spherical box of radiusR in the context of general relativity. We expect that configurations (i.e., initial data) which extremize total entropy will be spherically symmetric, time symmetric distributions of radiation in local thermodynamic equilibrium. Assuming this is the case, we prove that extrema ofS coincide precisely with static equilibrium configurations of the radiation fluid. Furthermore, dynamically stable equilibrium configurations are shown to coincide with local maxima ofS. The equilibrium configurations and their entropies are calculated and their properties are discussed. However, it is shown that entropies higher than these local extrema can be achieved and, indeed, arbitrarily high entropies can be attained by configurations inside of or outside but arbitrarily near their own Schwarzschild radius. However, if we limit consideration to configurations which are outside their own Schwarzschild radius by at least one radiation wavelength, then the entropy is bounded and we find Smax ≲ MR, whereM is the total mass. This supports the validity for self-gravitating systems of the Bekenstein upper limit on the entropy to energy ratio of material bodies.
Memory bias in the assessment and recall of pre-exam anxiety: How anxious was I?

This study investigated retrospective evaluations of past emotional states. Twenty-nine graduate students rated their anxiety one day prior to their comprehensive examination. Approximately 1 month later, they attempted to recall their pre-exam anxiety ratings. Half the students recalled after being informed that they had passed the exam, while the others recalled while still awaiting a decision. Students as a whole, but especially those who knew they had passed, recalled being more anxious than what they had reported initially. Thus one's recollection of a prior emotional state may be influenced by one's current emotional state. Copyright © 1998 John Wiley & Sons, Ltd.
The Isotope Effect in Superconductivity. I. Mercury

The critical magnetic fields of various isotopic mixtures of mercury have been measured as a function of temperature. The critical magnetic field at any temperature is found to decrease with increasing average mass, and the critical temperature also decreases with increasing mass. The relationship ${M}^{\frac{1}{2}}{T}_{c}=\mathrm{const}$, connecting the critical temperature ${T}_{c}$ and the average mass number $M$, is established. Conclusions are drawn concerning the specific heats of the normal and superconducting states of the isotopes.
A morphometric study of vascular smooth muscle cells in culture

Cultured arterial smooth muscle cells derived from different times in culture, different passages, and different species were evaluated by a combination of transmission electron microscopy and morphometry. The morphometric studies focused on point counting and monitored the following cellular components: lysosomes, myofilaments, mitochondria, ribosomes, and rough endoplasmic reticulum (RER). Percent volume composition values for the organelles involved in protein synthesis, namely ribosomes and RER, show significant fluctuations with time. Consistent with these observations, the cells showed increasing myofilaments during the early weeks in culture, which subsequently decreased significantly. The data also indicate that rabbit cells in culture may become synthetically quiescent with time and the distribution of cellular components is altered with each succeeding passage. Cultured calf (bovine) cells exhibit similar activity periods compared to rabbit but show a significantly higher lysosomal and lower myofilament content than rabbit. Calf cells could not be maintained for longer than 21 days in the absence of ascorbate, whereas ascorbate affects the ultrastructure of rabbit cells less dramatically. Age, passage, and donor, among others, are important considerations for studying in vitro smooth muscle cells. With proper morphologic and morphometric monitoring, these smooth muscle cell culture systems can be important tools in the study of aging or pathologic processes, or both.
The Delta-Corrected Kolmogorov-Smirnov Test With Estimated Parameters

The empirical distribution function used in the classical Kalmogorov-Smimov test involving estimated parameters is redefined in such a way that it becomes a function of a parameter called delta. Simulation results for three important practical cases indicate that the size of the test is not affected by delta on the unit interval, and that power can be increased by as many as ten percentage points. A goodness of fit test procedure for the normal and exponential distributions with estimated parameters based on the mean and modal plotting positions is proposed as a replacement to the classical Kolmogorov-Smirnov test.
Prognostic value of serum cardiac troponin I and T in chronic dialysis patients: A 1-year outcomes analysis

Abstract To determine the incidence and prognostic value of increased serum cardiac troponin I and T concentrations over 12 months in chronic hemodialysis patients, we performed a retrospective chart review in 16 patients undergoing chronic renal hemodialysis randomly selected from the Regional Kidney Disease Program without prior knowledge of their cardiac status. Serum markers of myocardial injury (cardiac troponin I [cTnI], cardiac troponin T [cTnT], and creatine kinase MB [CK-MB]) were measured and clinical outcomes were assessed. At the beginning of the study, 12 of 16 (75%) patients had increased serum enzyme-linked immunosorbent assay (ELISA) cTnT concentrations greater than 0.20 μg/L, eight (50%) had increased serum CK-MB greater than 5.0 μg/L, and three (19%) had an increased cTnI greater than 0.8 μg/L. Over the 1-year study period, the cardiac event rate (n = 4 with fatal myocardial infarction) was correlated to the patients who displayed the higher elevations of cTnT, CKMB, and cTnI. In the remaining 12 patients studied at the end of 1 year, seven (58%) had increased ELISA cTnT levels and five (42%) had increased CK-MB levels; no patients had elevated cTnI levels. Reanalysis of ELISA cTnT values with a newly formulated Enzymun cTnT assay showed no significant differences. Our data suggest that whereas substantial increases in cardiac markers tended to have a poor prognostic outcome, there was a high incidence of increased cTnT and CK-MB concentrations without evidence of myocardial injury in chronic hemodialysis patients. The lack of absolute cardiospecificity of cTnT and CK-MB may prove cTnI to be the desired serum marker for the detection of myocardial injury in patients with chronic renal disease.
The Widening Mistrust between Youth and Police

The interaction between police and young people living in the inner city has received limited empirical review. This paper examines the experiences of inner city youth claiming to have been subjected to excessive police force or misconduct or both. The discussion is informed by a study of encounters between a sample of the two groups. The author contends that hostility and strain between police and inner city youth, particularly youth of color, are increasing. The paper also examines the consequences of these encounters and their implications for service providers and policymakers.
The effects on metabolic clearance when administering a potent CYP3A autoinducer with the prototypic CYP3A inhibitor, ketoconazole

Ketoconazole is recognized as the prototypical CYP3A inhibitor and is often used to determine the metabolic CYP3A liabilities of new chemical entities in preclinical and clinical studies. Ketoconazole has been commercially available for approximately 30 years and was marketed before drug-metabolizing enzymes were well characterized; consequently, little is known about its metabolic profile. Semagacestat, a γ-secretase inhibitor investigated as a potential therapy for Alzheimer's disease, was determined to be a potent CYP3A autoinducer in human hepatocytes. Two human studies were conducted to assess the induction potential of semagacestat. In the first study (study 1, n = 20), semagacestat increased the mean apparent clearance (CL/F) of oral midazolam (76-324 l/h) and nifedipine (63-229 l/h) as predicted from hepatocytes. In a second (steady-state) study (study 2, n = 20), semagacestat CL/F increased from 22 after a single dose to 31 l/h. Ketoconazole decreased semagacestat CL/F by 32% after a single dose of semagacestat [geometric means ratio estimate, 0.68; 90% confidence interval (CI). 0.64, 0.73] and 46% at steady state (geometric means ratio estimate. 0.54; 90% CI, 0.51, 0.58). Ketoconazole area under the concentration-time curve over 8 h decreased 49% from first to last day of semagacestat dosing. Semagacestat significantly increases the oral clearance of CYP3A substrates, confirming its inducer designation. More importantly, when administered with a potent CYP3A inducer at steady state, ketoconazole's plasma exposure decreased, indicating that it may also be cleared by CYP3A, other inducible enzymes or transporters, or both.
Acute severe asthma: Recent advances

Purpose of review Acute severe asthma is challenging to the clinician both in terms of recognition and appropriate treatment. About 30% of these episodes need admission to the medical intensive care unit with a mortality of 8%. Relapse rates vary from 7 to 15% depending on how well the patient is managed. The purpose of this review is to discuss recent advances in identification of risk factors, pathophysiology and management of acute severe asthma. Recent findings Although the exact mechanism for acute severe asthma is unclear, some that are implicated include inflammation, airway remodeling and downregulation of beta-receptors. None of the environmental factors have been clearly related to the development of near fatal attacks. Genetic polymorphisms have been associated with severe asthma. Lack of steroid responsiveness has been linked to severe asthma attacks. Chemokines and basement membrane changes characteristic of severe asthma are reported in a few studies. Lack of symptom perception in a certain group of patients with acute severe asthma leads to delayed interventions. Specific treatment modalities and ventilator management is reviewed. Summary Severe asthma is a phenotype of asthma with variable pathology and clinical presentation. Early recognition and timely intervention is needed to prevent significant mortality and morbidity.
Nitric oxide synthase derangements and hypertension in kidney disease.

Purpose of Review Nitric oxide (NO) deficiency occurs by multiple mechanisms and contributes to the pathogenesis of progression of chronic kidney disease (CKD) and its cardiovascular complications. This article concentrates on recent developments on the regulation of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) in chronic kidney disease and on the importance of the NO synthases in kidney disease progression, particularly in diabetic nephropathy.
Parainfluenza virus infections.

Abstract The importance of parainfluenza virus types 1, 2, and 3 in childhood respiratory disease has been established. Parainfluenza virus type 1 is the leading cause of laryngotracheobronchitis (croup). Parainfluenza virus type 2, although less common than type 1, is also a major cause of croup. Parainfluenza virus type 3 ranks second only to respiratory syncytial virus as a cause of bronchiolitis and pneumonia in young children. Parainfluenza virus type 4 has been isolated infrequently and its importance as a human pathogen has not been determined. Attempts to develop effective, inactivated, parenterally administered vaccines for the parainfluenza viruses have been unsuccessful. Evidence suggests that the stimulation of local immune responses is more important than serum antibody. Recent efforts in vaccine development have emphasized preparations given intranasally which stimulate local immune response.
Steroid research at Syntex: "the pill" and cortisone.

The period from late 1949 through 1951 was an extraordinarily productive one in steroid chemistry and especially so at Syntex S.A. in Mexico City. Two of the most important Syntex contributions--the synthesis of 19-nor-17 alpha-ethynyltestosterone (norethindrone) and of cortisone from diosgenin--are described from a historical perspective.
Decreased oxygen need as a factor in anemia of hypophysectomized animals.

SummaryAdult female rats were hypo-physectomized and studied 60 days later; they exhibited the usual post-hypophysec-tomy anemia. The theory that the anemia in the hypophysectomized animal is simply a reflection of a decreased need for oxygen is supported by the finding that oxygen consumption was decreased in these animals and that it remained at a low level even when the peripheral blood picture was restored to normal via transfusion of whole blood. The theory is further supported by the finding that procedures which altered the erythrocyte level caused a similar change in oxygen consumption, and by much evidence indicating that the bone marrow can function normally in the absence of the pituitary gland.
Refractive Index Dispersion Curves Measured for Several Polymer Films

We use interference fringes measured in transmission spectra combined with high-accuracy index measurements at point wavelengths to construct dense, high-accuracy refractive index curves across the visible for several polymer films.