cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical Simulation of Near Wakes Utilizing a Relaxation Turbulence Model

Numerical solutions of the Navier-Stokes equations are presented for the turbulent supersonic near wake of a two-dimensional wedge/flat-plate model. The turbulent closure is provided by a relaxation eddy viscosity model having its origin in mixing length theory, the velocity defect law, and the classic description of the wake. In the present analysis, further study was made of a composite eddy viscosity model which includes the boundary-layer and wake regions. Although the near-wake region is characterized by strong turbulent inviscid-viscous interaction, results indicate that this complex wake flow can be numerically simulated using a simple relaxation eddy viscosity model.
Biophysics of zebrafish (Danio rerio) sperm.

Abstract In the past two decades, laboratories around the world have produced thousands of mutant, transgenic, and wild-type zebrafish lines for biomedical research. Although slow-freezing cryopreservation of zebrafish sperm has been available for 30 years, current protocols lack standardization and yield inconsistent post-thaw fertilization rates. Cell cryopreservation cannot be improved without basic physiological knowledge, which was lacking for zebrafish sperm. The first goal was to define basic cryobiological values for wild-type zebrafish sperm and to evaluate how modern physiological methods could aid in developing improved cryopreservation protocols. Coulter counting methods measured an osmotically inactive water fraction (Vb) of 0.37 ± 0.02 (SEM), an isosmotic cell volume ( V o ) of 12.1 ± 0.2 μm 3 (SEM), a water permeability ( L p ) in 10% dimethyl sulfoxide of 0.021 ± 0.001(SEM) μm/min/atm, and a cryoprotectant permeability ( P s ) of 0.10 ± 0.01 (SEM) × 10 −3 cm/min. Fourier transform infrared spectroscopy indicated that sperm membranes frozen without cryoprotectant showed damage and lipid reorganization, while those exposed to 10% glycerol demonstrated decreased lipid phase transition temperatures, which would stabilize the cells during cooling. The second goal was to determine the practicality and viability of shipping cooled zebrafish sperm overnight through the mail. Flow cytometry demonstrated that chilled fresh sperm can be maintained at 92% viability for 24 h at 0 °C, suggesting that it can be shipped and exchanged between laboratories. Additional methods will be necessary to analyze and improve cryopreservation techniques and post-thaw fertility of zebrafish sperm. The present study is a first step to explore such techniques.
A Reinvestigation of the Photochemistry of 2-Alkoxy-1,4-naphthoquinones

Abstract The irradiation of 2-ethoxy-1,4-naphthoquinone with allyl alcohol and 3-butenol affords diols containing the novel spiro[3.3]heptane unit.
Aggregation of a Class of Large-scale, Interconnected, Nonlinear Dynamical Systems

In this paper, the authors consider the issue of the construction of a meaningful average for a collection of nonlinear dynamical systems. Such a collection of dynamical systems may or may not have well defined ensemble averages as the existence of ensemble averages is predicated on the specification of appropriate initial conditions. A meaningful “average” dynamical system can represent the macroscopic behavior of the collection of systems and allow us to infer the behavior of such systems on an average. They can also prove to be very attractive from a computational perspective. An advantage to the construction of the meaningful average is that it involves integrating a nonlinear differential equation, of the same order as that of any member in the collection. An average dynamical system can be used in the analysis and design of hierarchical systems, and will allow one to capture approximately the response of any member of the collection.
Statins and Prostate Cancer Risk: A Case-Control Study

Observational studies have shown that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) use may be associated with reduced cancer risk. The purpose of this case-control study was to elucidate the association between statin use and prostate cancer risk. Prostate cancer cases (n ¼ 100), recruited upon referral for prostate biopsy, and frequency age-matched, prostate-specific antigen-normal clinic controls (n ¼ 202) were recruited from the Portland, Oregon, Veterans Affairs Medical Center. Information on any use of statins from May 1997 through August 2004 was obtained from an electronic pharmacy database. Days of use, type of statin, dose, and prescription changes were recorded. Duration and intensity were calculated for each statin type on the basis of days of use and prescribed dose. Thirty-six percent of cases and 49 percent of controls had a record of any statin use. Following adjustment for other potential risk factors, statin use was associated with a significant reduction in prostate cancer risk (odds ratio ¼ 0.38, 95% confidence interval: 0.21, 0.69). Furthermore, in analyses stratified by Gleason score, the inverse association with statin use was maintained only among men with Gleason scores of � 7 (odds ratio ¼ 0.24, 95% confidence interval: 0.11, 0.53). The results of this case-control study suggest that statins may reduce the risk of total prostate cancer and, specifically, more aggressive prostate cancer. case-control studies; cholesterol; hydroxymethylglutaryl-CoA reductase inhibitors; mevalonic acid; prostatespecific antigen; prostatic neoplasms; veterans
A Further Study of Gravity Wave Induced Drag and Diffusion in the Mesosphere

Lindzen's (1967) parameterization for the drag and eddy diffusion produced by breaking internal gravity waves in the mesosphere and lower thermosphere is applied to a modified version of the beta-plane channel model of Holton (1982) in which an isotropic source spectrum of waves is specified similar to that given in 1982 by Matsuno (1982). The transmission for each wave component is influenced by Newtonian cooling and by eddy diffusion induced by the breaking of other wave components. In general the waves with smallest Doppler-shifted phase speeds break first and produce sufficient eddy diffusion to significantly raise the breaking heights for the higher speed components. Thus, the wave drag and diffusion is spread through a deep layer and the resulting mean wind profiles for both summer and winter solstice conditions are more realistic than those computed previously by Holton.
Boolean Functions Over Nano-Fabrics: Improving Resilience Through Coding

This paper determines mechanisms to mitigate errors when implementing Boolean functions in nano-circuits. Nano-fabrics are expected to have high defect rates as atomic variations directly impact such materials. This paper develops a coding mechanism that uses a combination of cheap, but unreliable nano-device as the main function and reliable, but expensive CMOS devices to implement the coding mechanism. The unique feature of this paper is that it exploits the don't-cares that naturally occur in Boolean functions to construct better codes. The reliable Boolean function problem is cast as a constraint satisfaction problem and then solved using a tree-based dynamic programming algorithm. (Here, the word “dynamic programming” is used in the same sense as computer-science literature, i.e., and as an efficient search algorithm over trees).
Electrochemically Active Nanocrystalline SnO2 Films: Surface Modification with Thiazine and Oxazine Dye Aggregates

Thin films of SnO{sub 2}, nanocrystallites have been surface-modified with thionine, methylene blue, and oxazine 170 by adsorption from the corresponding dye solutions. The strong electrostatic interaction between the cationic dye and the negatively charged semiconductor nanocrystallites results in close packing of the dye on the semiconductor surface. These closely packed H-aggregates of the adsorbed dye are active both electrochemically and photoelectrochemically. Electron transfer from semiconductor nanocrystallites into the adsorbed dye aggregates leads to bleaching of the colored film. The extent of dye bleaching which is readily controlled by the applied potential, has been probed by spectroelectrochemical measurements. The photocurrent action spectra of these dye-modified SnO{sub 2} films indicate charge injection from excited dye aggregate into the semiconductor nanocrystallites with an incident photon-to-photocurrent efficiency of < 1 %.
Comments on the genesis and evolution of Apollo XI ‘soil’

Abstract Estimates of compositions of Apollo XI elastic materials and igneous rocks, derived from a review of published data, are used to construct major-element variation diagrams. Compositional differences between ‘soil’ and igneous rocks, previously ascribed by Goles and co-workers to the presence of a cryptic component, do not result solely from admixture of anorthositic lithic fragments. Some inferences on fractionation trends and fractionation mechanisms for lunar igneous rocks can also be drawn from the variation diagrams. The cryptic component is probably laterally-transported material from the region near Tranquility Base. It may convey information about the composition of large portions of the lunar surface. Ancient cryptic components, carrying similar information, perhaps could be studied in lunar breccias.
Noisy Neighbors Can Hamper the Evolution of Reproductive Isolation by Reinforcing Selection

AbstractReinforcement is the process by which selection against hybridization leads to an increase in reproductive isolation. The influence of reinforcing selection can be detected when sympatric individuals (those from areas of secondary contact) show a higher degree of prezygotic isolation than allopatric individuals (those from areas outside each other’s range). In areas of secondary contact with Drosophila santomea, Drosophila yakuba females show reinforcement of gametic isolation but not behavioral isolation, despite the fact that both behavioral and gametic isolation evolve in D. yakuba in experimental sympatry. Using behavioral assays and experimental evolution, I studied how both gametic and behavioral isolation are affected by biotic factors that the two species encounter in their natural environment. I show that if D. yakuba females are in environments where D. yakuba, D. santomea, and males from other species coexist, these females cannot fully discern between conspecific and heterospecific mal...
Heavy fermion production and the symmetry breaking sector of the electroweak interactions

Abstract We point out that heavy fermion production through the fusion of the longitudinal gauge bosons might be relevant in probing the strongly interacting symmetry breaking sector of the electroweak interactions, by showing the dependence of the one loop amplitude for ( w + w − → t t ) on the symmetry breaking mechanism. The one loop amplitude for ( w + w − → t t ) is calculated for the standard model and extended technicolour theory. Techni-rho meson exchange is also briefly discussed. We find that at m t =150 GeV the cross section of top pair production in e + e − collisions is comparable in order of magnitude to that of the longitudinal gauge boson scattering.
A family of robot control strategies for intermittent dynamical environments

A formalism is developed for describing and analyzing a very simple representative class of robotic tasks that require dynamical dexterity-among them, the task of juggling. The authors review their empirical success to date with a new class of control algorithms for this task domain, called mirror algorithms. The formalism for representing the task domain and encoding within it the desired robot behavior enables them to prove that a suitable mirror algorithm is correct with respect to a specified task. >
The First Year’s Operating Experience: GE LM2500 Gas Turbine in USS Spruance (DD-963)

The Spruance (DD-963) Class destroyers are the first all-gas turbine powered combatant ships in the US Navy. The first of the 30-ship class entered Navy operational service in September 1975. This paper presents the operational experience of the LM2500 Gas Turbines and the propulsion system from that time to the present. It includes experience obtained from all Spruance class destroyers now and soon-to-be commissioned.Copyright © 1977 by ASME
The creation of a new underclass in China and its implications

The emergence of a new urban underclass in China is a major challenge confronting the Communist Party, and its potential for fomenting instability has unnerved the Party. A strong case can be made, however, that the members of this emerging group have been cast into their current plight chiefly as a result of the marketization reforms that the regime itself set into motion two and a half decades ago. The group is comprised of recently laid-off workers, underpaid and underprivileged migrant labourers from the countryside, and any others who have fallen into penury with the withdrawal of job and welfare security and the elimination of free health care in the cities, which have accompanied the government's “economic reforms”. However, the challenge may not be as great as is often feared, for the same reforms have equipped the leadership with a battery of “weapons” that have the power to mitigate the expression of grievances, including new welfare measures, state-of-the-art surveillance technologies and crowd...
Scherk-Schwarz supersymmetry breaking in 4D

Using the techniques of dimensional deconstruction, we present 4D models that fully reproduce the physics of 5D supersymmetric theories compactified on an $$ {S}^1/{\mathrm{\mathbb{Z}}}_2 $$ orbifold with general Scherk-Schwarz supersymmetry breaking (SSSB) boundary conditions. In contrast to previous approaches, our deconstruction involves only soft supersymmetry breaking. Deconstruction preserves many of the attractive features of SSSB without the cumbersome architecture of a full fifth dimension, ambiguity of the ultraviolet completion, or challenges associated with stabilizing a large radius of compactification. We proceed to deconstruct various five-dimensional models featuring Scherk-Schwarz boundary conditions, including folded supersymmetry.
SOCIAL SECURITY EVALUATION: A CRITIQUE

I study the bias of actuarially fair measures commonly used to evaluate the impact of a social security system on the well-being of individuals. I investigate how the magnitude of this bias is affected by different features of a pay-as-you-go social security system. Social security affects an individual's welfare in ways other than through its direct effect on her lifetime income. It influences labor and savings decisions and hence factor prices, affecting labor income and the return to savings. Although social security can provide insurance against risk, it can also push borrowing-constrained individuals further away from their optimal consumption paths. I show that, by ignoring these features, actuarially fair measures can grossly misevaluate the impact of social security on the well-being of an individual.
Computer simulation of earthquakes

In a computer simulation study of earthquakes a seismically active strike slip fault is represented by coupled mechanical blocks which are driven by a moving plate and which slide on a friction surface. Elastic forces and time independent friction are used to generate main shock events, while viscoelastic forces and time dependent friction add aftershock features. The study reveals that the size, length, and time and place of event occurrence are strongly influenced by the magnitude and degree of homogeneity in the elastic, viscous, and friction parameters of the fault region. For example, periodically reoccurring similar events are observed in simulations with near-homogeneous parameters along the fault, whereas seismic gaps are a common feature of simulations employing large variations in the fault parameters. The study also reveals correlations between strain energy release and fault length and average displacement and between main shock and aftershock displacements.
NAFTA: Setting the Record Straight

HE North American Free Trade Agreement (NAFTA) was sold on the basis that it would bring a substantial expansion of US exports to Mexico and boost Mexico’s economic growth. Since its passage, however, not everything has gone as planned. In 1995 — scarcely a year after NAFTA came into effect — Mexico was in the midst of its worst economic crisis in decades. Meanwhile, rather than the anticipated expansion, US exports to Mexico went down. Has, then, NAFTA failed? The short answer is ‘no’. While many more years will be required before it is possible to make a meaningful assessment of the agreement, NAFTA’s expected benefits are beginning to materialise. Trade among the three NAFTA countries has been expanding to record levels and the number of US-Mexican business partnerships is on the rise. Moreover, despite the 45 per cent real devaluation of the peso, the seven per cent drop in Mexican output and Mexico’s 22 per cent fall in real wages during 1995, 1 US exports to Mexico were much less affected than Japanese or European exports largely thanks to NAFTA. Indeed, while exports to Mexico from the rest of the world, notably Japan and the European Union, fell by about 25 per cent, US exports contracted by less than two per cent. 2 Despite these positive trends, many Americans in and out of the Congress are proclaiming that NAFTA was a mistake. To a large extent, the statements against NAFTA are based on erroneous beliefs or egregious distortions. NAFTA is blamed for US job losses or declining living standards of workers, particularly the unskilled. In reality, the impact of NAFTA on gross job displacement in the United States has been negligible. Furthermore, there is some evidence that NAFTA’s net employment effect (the difference between jobs displaced and jobs created) has been positive.
Supermajority voting requirements for tax increases: evidence from the states

Abstract This paper measures the effect of state-level supermajority requirements for tax increases on tax rates. Unobserved attitudes towards taxation tend to influence both the adoption of supermajority requirements and tax policy. Consequently, one cannot distinguish between the effect of these requirements and their correlation with these unobserved attitudes. A model is presented in which legislatures controlled by a pro-tax party adopt a supermajority requirement to reduce the majority party agenda control. The propensity of pro-tax states to adopt supermajority requirements results in an underestimate of the true effect of these requirements on taxes. To correct this identification problem, the paper first uses fixed effects to control for unobserved attitudes and then employs instruments that measure the difficulty of amending state constitutions. The paper concludes that supermajority requirements have significantly reduced taxes.
1-Methoxy-1-(phenylthio)cyclopropanes from olefins via the Pummerer rearrangement

Abstract The Pummerer rearrangements of cyclopropyl(methoxy)phenylsulfonium salts proceed via sulfur-stabilized carbocations to yield the title compounds. The sulfonium salts were prepared in high yields from olefins via carbene addition, oxidation, and methylation.
Twin Towers of Hanoi

In the Twin Towers of Hanoi version of the well known Towers of Hanoi Problem there are two coupled sets of pegs. In each move, one chooses a pair of pegs in one of the sets and performs the only possible legal transfer of a disk between the chosen pegs (the smallest disk from one of the pegs is moved to the other peg), but also, simultaneously, between the corresponding pair of pegs in the coupled set (thus the same sequence of moves is always used in both sets). We provide upper and lower bounds on the length of the optimal solutions to problems of the following type. Given an initial and a final position of n disks in each of the coupled sets, what is the smallest number of moves needed to simultaneously obtain the final position from the initial one in each set? Our analysis is based on the use of a group, called Hanoi Towers group, of rooted ternary tree automorphisms, which models the original problem in such a way that the configurations on n disks are the vertices at level n of the tree and the action of the generators of the group represents the three possible moves between the three pegs. The twin version of the problem is analyzed by considering the action of Hanoi Towers group on pairs of vertices.
Zonal winds in the middle atmosphere of Venus from Pioneer Venus radio occultation data

The present investigation is concerned with the derivation of zonal winds for the middle atmosphere (40-80 km) of Venus, using Pioneer Venus (PV) radio occultation data. The considered altitude range is of particular interest because the atmospheric circulation of Venus is uncertain above the cloud tops (65-70 km). The Pioneer Venus orbiter began circling the planet every 24 hours on December 4, 1978. Four seasons of occultation data have now been collected. It is found that the assumption of cyclostrophic balance, in conjunction with radio occultation derived temperature data, yields a zonal wind field for most of the middle atmosphere of Venus. An intense midlatitude jet at and above the cloud tops is the most notable feature of the winds.
The role of diminishing returns in neo-Schumpeterian growth theory*

This paper generalizes Segerstrom [5], a dynamic general equilibrium model of endogenous growth through quality improvements in which innovation and imitation are modeled as the outcomes of research and development (R&D) races. Specific factors introduced into the technologies of both R&D activities achieve diminishing returns to scale in R&D. The comparative-static results of subsidies to R&D activities depend on the degree of diminishing returns to scale in R&D. When there is (is not) a sufficient degree of diminishing returns to R&D, a subsidy to innovative activity increases (decreases) innovative activity.
Cross-Cultural Differences in Risk Perception: A Model- Based Approach

The present study assessed cross-cultural differences in the perception of financial risks. Students at large universities in Hong Kong, Taiwan, the Netherlands, and the U.S., as well as a group of Taiwanese security analysts rated the riskiness of a set of monetary lotteries. Risk judgments differed with nationality, but not with occupation (students vs. security analysts) and were modeled by the Conjoint Expected Risk (CER) model.(1) Consistent with cultural differences in country uncertainty avoidance,(2) CER model parameters of respondents from the two Western countries differed from those of respondents from the two countries with Chinese cultural roots: The risk judgments of respondents from Hong Kong and Taiwan were more sensitive to the magnitude of potential losses and less mitigated by the probability of positive outcomes.
Gauge coupling unification with extra dimensions and gravitational scale effects

Abstract We study gauge coupling unification in the presence of extra dimensions compactified at a few TeV. Achieving unification requires a large number of gauge boson Kaluza–Klein excitations lighter than the string scale, such that the higher-dimensional gauge couplings are O (1) in string scale units. Corrections to the gauge couplings from two or more loops are about 10% or larger, hence string (or M) theory is generally expected to be strongly coupled in ∼TeV-scale extra-dimensional scenarios. Higher-dimensional operators induced by quantum gravitational effects can shift the gauge couplings by a few percent. These effects are sufficiently large that even the minimal Standard Model, or the MSSM, allow unification at a scale in the ∼TeV range. The strongly coupled unified theory may induce dynamical electroweak symmetry breaking.
Watching Television Without Pity: The Productivity of Online Fans

Increasingly, online fan sites are providing instant feedback to television writers and scriptwriters, who are starting to pay more attention to the chatter of “the boards.” At the same time, the b...
Advantageous Use of tBu2P-N═P(iBuNCH2CH2)3N in the Hiyama Coupling of Aryl Bromides and Chlorides

An efficient catalytic route to biaryls by employing (generally) only 0.25 mol % of Pd(OAc)2 and 0.5 mol % of 1 in the Hiyama coupling reaction is reported. High yields for electron-rich, -neutral, and -deficient aryl chlorides are obtained. A variety of phenylsiloxanes undergo coupling with aryl bromides and chlorides with low Pd(OAc)2/1 loadings.
A purified recombinant organophosphorus acid anhydrase protects mice against soman

Since pharmacologic treatments of organophosphorus anticholinesterases (OPs) are nearing their practical limit other types of treatment are being sought. One approach is the prophylactic administration of scavengers that will detoxify OPs before they reach their critical target site. We have shown that mice which have been treated with a purified organophosphorus acid anhydride hydrolase (OPAH) are not measurably affected by doses of soman that are lethal to untreated animals. This result indicates that this approach is worthy of exploration and development for protecting military personnel and agriculture workers against OP intoxication.
HYBRID MECHANISMS FOR GAS/ICE GIANT PLANET FORMATION

The effects of gas pressure gradients on the motion of solid grains in the solar nebula substantially enhance the efficiency of forming protoplanetary cores in the standard core accretion model in "hybrid" scenarios for gas/ice giant planet formation. Such a scenario is enhanced core accretion that results from Epstein drag-induced inward radial migration of millimeter-sized grains and subsequent particle subdisk gravitational instability needed to build up a population of 1 km planetesimals. Solid/gas ratios can be enhanced by nearly ~10 times over those in a minimum mass solar nebula (MMSN) distribution in the outer solar nebula (a > 20 AU), increasing the oligarchic core masses and decreasing formation timescales for protoplanetary cores. A 10 M⊕ core can form on ~106-107 yr timescales at 15-25 AU, compared to ~108 yr in the standard model, alleviating the major problem plaguing the core accretion model for gas/ice giant planet formation.
A semiparametric modeling framework for potential biomarker discovery and the development of metabonomic profiles

The discovery of biomarkers is an important step towards the development of criteria for early diagnosis of disease status. Recently electrospray ionization (ESI) and matrix assisted laser desorption (MALDI) time-of-flight (TOF) mass spectrometry have been used to identify biomarkers both in proteomics and metabonomics studies. Data sets generated from such studies are generally very large in size and thus require the use of sophisticated statistical techniques to glean useful information. Most recent attempts to process these types of data model each compound's intensity either discretely by positional (mass to charge ratio) clustering or through each compounds' own intensity distribution. Traditionally data processing steps such as noise removal, background elimination and m/z alignment, are generally carried out separately resulting in unsatisfactory propagation of signals in the final model. In the present study a novel semi-parametric approach has been developed to distinguish urinary metabolic profiles in a group of traumatic patients from those of a control group consisting of normal individuals. Data sets obtained from the replicates of a single subject were used to develop a functional profile through Dirichlet mixture of beta distribution. This functional profile is flexible enough to accommodate variability of the instrument and the inherent variability of each individual, thus simultaneously addressing different sources of systematic error. To address instrument variability, all data sets were analyzed in replicate, an important issue ignored by most studies in the past. Different model comparisons were performed to select the best model for each subject. The m/z values in the window of the irregular pattern are then further recommended for possible biomarker discovery. To the best of our knowledge this is the very first attempt to model the physical process behind the time-of flight mass spectrometry. Most of the state of the art techniques does not take these physical principles in consideration while modeling such data. The proposed modeling process will apply as long as the basic physical principle presented in this paper is valid. Notably we have confined our present work mostly within the modeling aspect. Nevertheless clinical validation of our recommended list of potential biomarkers will be required. Hence, we have termed our modeling approach as a "framework" for further work.
On folk theorems

We suggest criteria for a statement to be a folk theorem and illustrate the ideas with a detailed example.
Thermal Details in a Rotor–Stator Cavity at Engine Conditions With a Mainstream

This investigation involves a numerical study of enclosed rotor-stator cavities of gas turbine engines. The complete elliptic form of the 2-D, axisymmetric Navier-Stokes equations for compressible turbulent flow were solved. Included are the complete fluid and thermal effects of the hot mainstram gas interacting with the cooling cavity purge flow at actual engine flow conditions for generalized geometries. Additional flow conditions above and below those for engine nominal conditions are also considered. The relationships among the important flow parameters are investigated by examining the entire set of computations
A stereospecific synthesis of 2',3'-dideoxy-β-L-cytidine (β-L-ddC), a potent inhibitor against human hepatitis B virus (HBV) and human immunodeficiency virus (HIV)

Abstract 2′,3′-Dideoxy-β- l -cytidine (β- l -ddC), a potent inhibitor against human hepatitis B virus (HBV) and human immunodeficiency virus (HIV), has been stereospecifically synthesized from l -arabinose in 9 steps.
TCP-Illinois: A loss- and delay-based congestion control algorithm for high-speed networks

We introduce a new congestion control algorithm for high-speed networks, called TCP-Illinois. TCP-Illinois uses packet loss information to determine whether the window size should be increased or decreased, and uses queueing delay information to determine the amount of increment or decrement. TCP-Illinois achieves high throughput, allocates the network resource fairly, and is incentive compatible with standard TCP. We also build a new stochastic matrix model, capturing standard TCP and TCP-Illinois as special cases, and use this model to analyze their fairness properties for both synchronized and unsynchronized backoff behaviors. We finally perform simulations to demonstrate the performance of TCP-Illinois.
The Control of Politicians in Normal Times and Times of Crisis: Wealth Accumulation by U.S. Congressmen, 1850-1880

The Control of Politicians in Normal Times and Times of Crisis: Wealth Accumulation by U.S. Congressmen, 1850–1880
RADIATION-INDUCED THYROID CARCINOMA.

Epidemiologic studies show a definite relation between thyroid carcinoma and prior radiotherapy for various diseases in childhood. Information regarding such an association for persons treated during adult life is limited and difficult to obtain because of the long period between exposure and tumor development. Nevertheless, there is some evidence that such an association also exists in irradiated adults. None of the prospective investigations has been properly controlled, and for this reason the treated children studied may represent a selected group predisposed to develop thyroid neoplasia without exposure to ionizing radiation. However, two observations provide strong circumstantial evidence that radiation treatment is, indeed, a factor in thyroid tumor induction. First, in the retrospective studies, x-ray therapy was given to the head, neck, and chest for many unrelated conditions. This suggests that the radiation exposure, rather than the disease being treated, is a primary factor in the etiology of the thyroid neoplasia. Second, the development of excessive numbers of tumors can be related to a specific radiologic technique, that is, the use of anterior and posterior ports. Thus, a dose of x rays, if administered one- half to the anterior and one-half to the posterior chest, is associated with a higher thyroidmore » tumor incidence than if given anteriorly only. All of these studies are concerned with radiation from external sources. Insufficient data are currently available to conclude that radioiodine is also oncogenic. More definitive information may be provided when the results of a current national survey of patients treated with /sup 131/I are reported. (auth)« less
The Opaque Square

The problem of finding small sets that block every line passing through a unit square was first considered by Mazurkiewicz in 1916. We call such a set an opaque set or a barrier for the square. The shortest known barrier has length √2 + √6/2 = 2.6389.... The current best lower bound for the length of a (not necessarily connected) barrier is 2, of which the earliest record dates back to Jones in 1964. No better lower bound is known even if the barrier is restricted to lie in the square or in its close vicinity. Under a suitable locality assumption, we replace this lower bound, for barriers consisting of finitely many straight-line segments, by 2 + 10--12, which represents the first, albeit small, step in a long time toward finding the length of the shortest barrier. A sharper bound is obtained for interior barriers: the length of any interior barrier for the unit square, consisting of finitely many straight-line segments, is at least 2 + 10--5. Two of the key elements in our proofs are: (i) formulas established by Sylvester for the measure of all lines that meet two disjoint planar convex bodies, and, even more significant, (ii) a procedure for detecting lines that are witness to the invalidity of a short bogus barrier for the square.
Displacement Structure Approach to Discrete-Trigonometric-Transform Based Preconditioners of G.Strang Type and of T.Chan Type

In this paper we use a displacement structure approach to design a class of new preconditioners for the conjugate gradient method applied to the solution of large Toeplitz linear equations. Explicit formulas are suggested for the G.Strang-type and for the T.Chan-type preconditioners belonging to any of eight classes of matrices diagonalized by the corresponding discrete cosine or sine transforms. Under the standard Wiener class assumption the clustering property is established for all of these preconditioners, guaranteeing rapid convergence of the preconditioned conjugate gradient method. All the computations related to the new preconditioners can be done in real arithmetic, and to fully exploit this advantageous property one has to suggest a fast real-arithmetic algorithm for multiplication of a Toeplitz matrix by a vector. It turns out that the obtained formulas for the Strang-type preconditioners allow a number of representations for Toeplitz matrices leading to a wide variety of real-arithmetic multiplication algorithms based on any of eight discrete cosine or sine transforms. Recently, transformations of Toeplitz matrices to Vandermonde-like or Cauchy-like matrices have been found to be useful in developing accurate direct methods for Toeplitz linear equations. In this paper we suggest further extending the range of the transformation approach by exploring it for iterative methods; this technique allowed us to reduce the complexity of each iteration of the preconditioned conjugate gradient method. The results of this paper were announced in [T. Kailath and V. Olshevsky, Calcolo, 33 (1996), pp. 191--208].
A landscape of the new dark silicon design regime

The rise of dark silicon is driving a new class of architectural techniques that "spend" area to "buy" energy efficiency. In this talk we examine two new frameworks employed by computer architects to understand the challenges and opportunities that await us. The first is the utilization wall [3], a simple model that architects use to understand how technology scaling under post-Dennard assumptions will affect hardware design. The second framework is the four horsemen taxonomy [2] that comprises four key approaches that future chip designers will use to attack the dark silicon problem. We describe recent research projects that typify these approaches, including GreenDroid [6], a massively heterogeneous 28 nm processor being developed at UCSD. Finally, we conclude with some directions (and non-directions) that the human brain could offer for refactoring the computational stack for dark silicon [1].
MAGNETOHYDRODYNAMIC JUMP CONDITIONS FOR OBLIQUE RELATIVISTIC SHOCKS WITH GYROTROPIC PRESSURE

Shock jump conditions, i.e., the specification of the downstream parameters of the gas in terms of the upstream parameters, are obtained for steady-state, plane shocks with oblique magnetic fields and arbitrary flow speeds. This is done by combining the continuity of particle number flux and the electromagnetic boundary conditions at the shock with the magnetohydrodynamic conservation laws derived from the stress-energy tensor. For ultrarelativistic and nonrelativistic shocks, the jump conditions may be solved analytically. For mildly relativistic shocks, analytic solutions are obtained for isotropic pressure using an approximation for the adiabatic index that is valid in high sonic Mach number cases. Examples assuming isotropic pressure illustrate how the shock compression ratio depends on the shock speed and obliquity. In the more general case of gyrotropic pressure, the jump conditions cannot be solved analytically with- out additional assumptions, and the effects of gyrotropic pressure are investigated by parameterizing the distribution of pressure parallel and perpendicular to the magnetic field. Our numerical solutions reveal that relatively small departures from isotropy (e.g., approximately 20%) produce significant changes in the shock compression ratio, r , at all shock Lorentz factors, including ultrarelativistic ones, where an analytic solution with gyrotropic pressure is obtained. In particular, either dynamically important fields or significant pressure anisotropies can incur marked departures from the canonical gas dynamic value of r = 3 for a shocked ultrarelativistic flow and this may impact models of particle acceleration in gamma-ray bursts and other environments where relativistic shocks are inferred. The jump conditions presented apply directly to test-particle acceleration, and will facilitate future self-consistent numerical modeling of particle acceleration at oblique, relativistic shocks; such models include the modification of the fluid velocity profile due to the contribution of energetic particles to the momentum and energy fluxes.
Room temperature triplet state spectroscopy of organic semiconductors

Organic light-emitting devices and solar cells are devices that create, manipulate, and convert excited states in organic semiconductors. It is crucial to characterize these excited states, or excitons, to optimize device performance in applications like displays and solar energy harvesting. This is complicated if the excited state is a triplet because the electronic transition is 'dark' with a vanishing oscillator strength. As a consequence, triplet state spectroscopy must usually be performed at cryogenic temperatures to reduce competition from non-radiative rates. Here, we control non-radiative rates by engineering a solid-state host matrix containing the target molecule, allowing the observation of phosphorescence at room temperature and alleviating constraints of cryogenic experiments. We test these techniques on a wide range of materials with functionalities spanning multi-exciton generation (singlet exciton fission), organic light emitting device host materials, and thermally activated delayed fluorescence type emitters. Control of non-radiative modes in the matrix surrounding a target molecule may also have broader applications in light-emitting and photovoltaic devices.
Practice Parameter: Laryngeal Electromyography (An Evidence-Based Review):

This paper reports on an evidence-based review of laryngeal electromyography (EMG) as a technique for use in the diagnosis, prognosis, and treatment of laryngeal movement disorders including the laryngeal dystonias, vocal fold paralysis, and other neurolaryngological disorders. The authors performed a systematic review of the medical literature from 1944 through 2001 on the clinical application of EMG to laryngeal disorders. The review yielded 584 articles of which 33 met the predefined inclusion criteria. The evidence demonstrated that in a double-blind treatment trial of botulinum toxin versus saline, laryngeal EMG used to guide injections into the thyroarytenoid muscle in persons with adductor spasmodic dysphonia was beneficial. A cross-over comparison between laryngeal EMG-guided injection and endoscopic injection of botulinum toxin into the posterior cricoarytenoid muscle in abductor spasmodic dysphonia found no significant difference between the 2 techniques and no significant treatment benefit. Based on the evidence, laryngeal EMG is possibly useful for the injection of botulinum toxin into the thyroarytenoid muscle in the treatment of adductor spasmodic dysphonia. There were no evidence-based data sufficient to support or refute the value of laryngeal EMG for the other uses investigated, although there is extensive anecdotal literature suggesting that it is useful for each of them. There is an urgent need for evidence-based research addressing other applications in the use of laryngeal EMG for other applications.
The shock‐reprocessing model of electron acceleration in impulsive solar flares

We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of these electrons as they pass through a weakly compressive fast shock above the apex of the closed flare loop on their way to the chromosphere. We call this the ‘shock-reprocessing’ model. The model reproduces the sign and magnitude of the energy-dependent arrival time delays for both the pulsed and smooth component of impulsive solar flare X-rays, but requires either enhanced cooling or the presence of a loop-top trap to explain the concavity of the observed time delay energy relation for the smooth component. The model also predicts an emission site above the loop-top, as seen in the Masuda flare. The loop-top source distinguishes the shock-reprocessing model from previous models. The model makes testable predictions for the energy dependence of footpoint pulse strengths and the location and spectrum of the loop-top emission, and can account for the observed soft-hard-soft trend in the spectral evolution of footpoint emission. The model also highlights the concept that magnetic reconnection provides an environment which permits multiple acceleration processes. Which combination of processes operates within a particular flare may depend on the initial conditions that determine, for example, whether the reconnection downflow is turbulent or laminar. The shock-reprocessing model comprises one such combination.
J-trace identities and invariant theory

Abstract We generalize the notion of trace identity to J -trace. Our main result is that all J -trace identities of M n , n are consequences of those of degree 1 2 n ( n + 3 ) . This also gives an indirect description of the queer trace identities of M n ( E ) .
50 years of studies on the inner core

In 1986, we marked the 50th anniversary of the discovery of the earth's innercore. In atomic physics an equivalent act would warrant a Nobel prize. The credit is due to Inge Lehmann (Figure 1), who in 1936 was working as a seismologist at the Royal Danish Geodetic Institute, Copenhagen. Her proposal was published in the Bureau Central Seismologique International, Travaux Scientifique [Lehmann, 1936]:An explanation of the P3′ wave [i.e., PKIKP] is required, since now it can hardly be considered probable that it is due to diffraction. A hypothesis will be here suggested which seems to hold some probability, although it cannot be proved from the data at hand. We take it… that inside the core there is an inner core in which the velocity is larger than the outer core.
Management of separation pain after single-dose methotrexate therapy for ectopic pregnancy.

Abstract Objective: To evaluate the conservative management of pain after systemic methotrexate therapy for ectopic pregnancy; identify prognostic factors for success; and compare hCG resolution time for patients with and without pain. Methods: A retrospective review of patients with ectopic pregnancy requiring evaluation for pain after receiving single-dose methotrexate therapy is performed. Results of hematocrits, ultrasound findings, hCG levels, time for hCG levels to reach less than 15 mIU/mL, and outcome were noted. Results: Fifty-three patients with 64 episodes of pain were identified. Seven hospitalized patients required surgery during admission. Two previously hospitalized and one outpatient also ultimately underwent surgery. For hospitalized patients, there were no statistical differences between patients who did or did not undergo surgery during admission for any variable studied, including the presence of free peritoneal blood or rebound tenderness. However, comparison of hospitalized and nonhospitalized patients showed those with rebound tenderness were more likely to be admitted. Hospitalized patients not requiring surgery had shorter resolution time than nonhospitalized patients. For hospitalized and nonhospitalized patients, the median time from treatment to presentation for pain was 8 days. Conclusion: The occurrence of pain following methotrexate therapy for ectopic pregnancy should not be the sole indication for surgical intervention. The majority of stable patients with pain after methotrexate therapy, even with rebound or free peritoneal fluid, can be treated successfully without surgery, either in hospital with close observation for severe pain or as outpatients for patients with less severe pain.
Experimental measurements of phase space

Direct measurements of integrated phase-space densities, e.g., f(x,v/sub y/,t), have been made in an experiment. Using spectroscopically active ions, measurements in a plasma show the ion response, f/sub i/(x,v,t), to linear and nonlinear waves and phase-space particle bunching. Time-resolved measurements show coherent and incoherent phase-space density changes in the presence of waves, indicating that transitions to turbulence and chaos may be studied. The time, space, and velocity-space resolution may allow experimental tests of predictions from the Boltzmann equation.
The role of GIS in Digital Earth education

Abstract A growing number of educators worldwide have become convinced that geotechnologies – including geographic information systems (GIS), global positioning systems (GPS), and remote sensing – are key technologies to prepare students to be tomorrow's decision makers. Grappling with local, regional, and global issues of the 21st century requires people who think spatially and who can use geotechnologies. Some educators teach geotechnologies as a discipline, emphasising skills. Other educators use geotechnologies as a tool to teach content, such as geography, history, environmental studies, Earth Science, biology, mathematics, economics and other disciplines. Issues such as traffic, population growth, urban sprawl, energy, water, crime, human health, biodiversity and sustainable agriculture are growing in complexity, exist at every scale and increasingly affect people's everyday lives. Each of these issues has a spatial component. Drivers for geotechnology education include educational content standards...