cssi/SciSciGPT-SciSciNet huggingface dataset:
SPONTANEOUS ENCEPHALOMYELITIS OF MICE, A NEW VIRUS DISEASE.

1. The characteristics of a filterable virus obtained from mice found spontaneously paralyzed and showing lesions of encephalomyelitis are described. 2. The course of the disease in mice, following intracerebral inoculation, is briefly as follows: After an incubation period varying from 7 to over 30 days a flaccid paralysis of one of the limbs appears. This paralysis usually spreads rapidly until all four limbs are affected. Young mice are more susceptible than older ones, and very young mice, less than 4 weeks of age, usually die without showing signs of paralysis. 3. Adult mice often show no signs of infection after an intracerebral inoculation of virus. A number of these mice, although showing no signs of paralysis, nevertheless have become infected, a fact which is demonstrated by recovery of the virus from the mice as well as by histopathological studies. 4. Intranasal instillation of the virus is the only other method of producing the infection. This method, however, produces paralysis in only a small percentage of the mice. Following intranasal instillation of the virus, there often develops a slight immunity to a subsequent intracerebral injection of virus. 5. The paralysis in the surviving mice recedes gradually, but a permanent residual paralysis, usually of the hind legs, is almost invariable. Such mice, however, are virus carriers, as the virus can be recovered from the spinal cord for 1 year after infection. 6. Paralyzed mice are immune to a subsequent intracerebral injection of the virus. There is evidence that neutralizing substances are present in the immune mice. A considerable proportion of the mice which have remained well after an intracerebral injection of virus are immune to a second injection. 7. The virus resists the action of 50 per cent glycerine at from 2–4°C. for at least 150 days. It passes all grades of Berkefeld filters with ease. By the use of graded collodion filters, the size of the virus particle has been determined to be probably about 13 to 19 mµ. 8. The virus of mouse encephalomyelitis is not pathogenic for rhesus monkeys. No evidence of immunological relationship with the virus of human poliomyelitis has been obtained. 9. The anatomical basis of the paralysis is an acute necrosis of the ganglion cells of the anterior horn of the spinal cord. Isolated ganglion cells of the cerebrum also undergo necrosis. Following the acute necrosis of the ganglion cells, there is a marked neuronophagia. A perivascular infiltration is observed in the brain and spinal cord.
SYNTHESIS OF NEW PYRIDAZIN- 6-ONES, PYRIDAZIN-6-IMINES, 4-PYRIDAZINALS, AND PYRIDINES

ABSTRACT 3-Dimethyl-1-[3-methyl-(4H)-5-phenylimidazol[2,1-b]thiazol-2-yl]prop-2-enone 4 couples smoothly with benzenediazonium chloride to yield propanal 5 which is a key intermediate for the synthesis of pyridazinones 9–13, 16 and pyridazine-6-imine 8, 19. Pentadienonitrile 18 was converted into pyridine-3-carbonitrile 20 on refluxing in ethanolic sodium ethoxide solution. Pyrazole 24 was synthesized from the reaction of 5 with 1-chloro-2-phenylhydrazono propan-2-one 22.
Minimizing distortion in truss structures—A Hopfield network solution

Distortions in truss structures can result from random errors in elemental lengths that are typical of a manufacturing process. These distortions may be minimized by an optimal selection of elements from those available for placement between the prescribed nodes -- a combinatorial optimization problem requiring significant investment of computational resource for all but the smallest problems. The present paper describes a formulation in which near-optimal element assignments are obtained as minimum energy, stable states, of an analogous Hopfield neural network. This requires mapping of the optimization problem into an energy function of the appropriate Lyapunov form. The computational architecture is ideally suited to a parallel processor implementation and offers significant savings in computational effort. A numerical implementation of the approach is discussed with reference to planar truss problems.
Theory of Superconductivity

A theory of superconductivity is presented, based on the fact that the interaction between electrons resulting from virtual exchange of phonons is attractive when the energy difference between the electrons states involved is less than the phonon energy, $\ensuremath{\hbar}\ensuremath{\omega}$. It is favorable to form a superconducting phase when this attractive interaction dominates the repulsive screened Coulomb interaction. The normal phase is described by the Bloch individual-particle model. The ground state of a superconductor, formed from a linear combination of normal state configurations in which electrons are virtually excited in pairs of opposite spin and momentum, is lower in energy than the normal state by amount proportional to an average ${(\ensuremath{\hbar}\ensuremath{\omega})}^{2}$, consistent with the isotope effect. A mutually orthogonal set of excited states in one-to-one correspondence with those of the normal phase is obtained by specifying occupation of certain Bloch states and by using the rest to form a linear combination of virtual pair configurations. The theory yields a second-order phase transition and a Meissner effect in the form suggested by Pippard. Calculated values of specific heats and penetration depths and their temperature variation are in good agreement with experiment. There is an energy gap for individual-particle excitations which decreases from about $3.5k{T}_{c}$ at $T=0\ifmmode^\circ\else\textdegree\fi{}$K to zero at ${T}_{c}$. Tables of matrix elements of single-particle operators between the excited-state superconducting wave functions, useful for perturbation expansions and calculations of transition probabilities, are given.
Influence of organic matter on the availability of certain elements to barley seedlings grown by a modified neubauer method

The influence of organic matter on the availability of 17 elements (Na, K, Cs137, Mg, Ca, Sr, Ba, N, P, B, Cu, Zn, Fe, Mn, Mo, Al, and Si) to barley seedlings grown by a modified Neubauer technique was determined. Three different soils that were treated with dry ground mustard spinach leaves (1 g/100 g soil) and incubated for various lengths of time (0, 1, 2, 5, 9, 13, and 17 weeks) in moist condition before cropping were used for this study.
White-light optical Fourier transform device

The construction and operation of a new optical phase plate assembly is described that takes the Fourier transform of an intensity image in white light. It consists of symmetrical wedges of birefringent crystals that induce an angle between the wave fronts of the polarized components of the output beam. The wave-front angle is shown to be linearly proportional to the angle of incidence. This is sufficient to generate the necessary phase factor for a Fourier transform.
Local Acoustic Forcing of a Wing at Low Reynolds Numbers

At transitional Reynolds numbers (104−105), many smooth airfoils experience laminar flow separation and possible turbulent reattachment, where the occurrence of either state is strongly influenced by small changes in the surrounding environment. The Eppler 387 airfoil is one of many airfoils that can have multiple lift and drag states at a single wing incidence angle. Prestall hysteresis and abrupt switching between stable states occur due to sudden flow reattachment and the appearance of a separation bubble close to the leading edge. Here, we demonstrate control of the flow dynamics by localized acoustic excitation through small speakers embedded beneath the suction surface. The flow can be controlled not only through variations in acoustic power and frequency, but also through spatial variations in forcing location. Implications for control and stabilization of small aircraft are considered.
Explaining the contemporary alignment of race and party: Evidence from California's 1946 Ballot initiative on fair employment

Why do most African Americans and other racial liberals vote Democratic, whereas most racial conservatives—largely whites—vote Republican? To what extent is this alignment of race and party attributable to the strategic choice of GOP elites to take the party in a racially conservative direction during the mid-1960s? This paper exploits a little-known ballot initiative in postwar California to shed light on the question. Proposition 11, as it was known, would have outlawed discrimination in employment if it had passed. Instead, it failed by more than a two-to-one margin. Drawing on archival and statistical evidence, including the ecological analysis of precinct-level election returns, we find that Republican voters were much more likely than Democratic voters to oppose Proposition 11, despite Republican Governor Earl Warren's well-known support for fair employment practices (FEP) legislation. We conclude that many Republican voters tended strongly toward racial conservatism well before Republican elites decided to pursue racially conservative policies in the mid-1960s. We suggest that the emergence of the contemporary alignment of race and party may have been less contingent on elite strategy and more structurally determined than the conventional wisdom allows.
Indirect Template Method of Magnetic Field Assisted Assembly

Indirect Template Magnetic Field Assisted Assembly (IT-MFAA), a parallel processing technique, is presented. IT-MFAA is designed to assemble devices onto substrates through a versatile and scalable methodology, which is capable of adjusting to manufacturing situations and producing 100% yields with error correction. This paper discusses existing serial and parallel techniques and compares them to IT-MFAA. It demonstrates that IT-MFAA circumvents drawbacks present in other techniques, and outlines a model of IT-MFAA.
Two-dimensional Hydrodynamical Simulations of Wind-compressed Disks around Rapidly Rotating B Stars

We use a 2-D PPM code to simulate numerically the hydrodynamics of a radiation-driven stellar wind from a rapidly rotating Be-star. The results generally confirm predictions of the semi-analytic “Wind Compressed Disk” model recently proposed by Bjorkman and Cassinelli to explain the cir­cumstellar disks inferred observationally to exist around such rapidly rotat­ing stars. However, this numerical simulation is able to incorporate several important effects not accounted for in the simple model, including a dynam­ical treatment of the outward radiative driving and gas pressure, as well as a rotationally oblated stellar surface. This enables us to model quantitatively the compressed wind and shock that forms the equatorial disk. The sim­ulation results thus do differ in several important details from the simple model, showing, for example, cases of inner disk inflow not possible in the heuristic approach of assuming a fixed outward velocity law. In addition, the disk opening typically has a half-angle of 2–4 degrees, somewhat larger than the ∼ 0.5° predicted from the analytic model, and there is no evidence for the predicted detachment of the disk that arises in the fixed outflow picture.
Authentication Planning for XOR Network Coding

This paper formulates the authentication planning problem when network coding is implemented in a wireless sensor network. The planning problem aims at minimizing the energy consumed by the security application which is guarantied using message authentication codes. This paper proposes a binary non-linear optimization formulation for this planning problem whose decision variables are the authentication decision of the nodes and the MAC modes of operation. It is illustrated for a butterfly topology. Results show that there is a real trade-off between energy efficiency and message throughput in this context
Current Technology of Radial-Inflow Turbines for Compressible Fluids

Radial turbines have been used for hydraulic, steam, and gas turbine service. In hydraulic turbine practice, a substantial regime of specific speed is reserved exclusively for Francis turbines. No similar situation is found with compressible fluids, where axial turbines are used for the entire specific speed range of practical interest. Francis turbines consistently achieve efficiencies of 90–94 percent, but their counter parts in compressible fluid machines generally are thought to be inferior to axial turbines in performance. Review of available data indicates that radial inflow turbines with compressible fluids can approach or equal the performance of equivalent hydraulic turbines and that, in the specific speed range to which they are applicable, they can match axial turbine performance. Criteria are given which may be used for determination of the suitability of radial turbines for specific requirements.
Constructing sublinear expectations on path space

Abstract We provide a general construction of time-consistent sublinear expectations on the space of continuous paths. It yields the existence of the conditional G -expectation of a Borel-measurable (rather than quasi-continuous) random variable, a generalization of the random G -expectation, and an optional sampling theorem that holds without exceptional set. Our results also shed light on the inherent limitations to constructing sublinear expectations through aggregation.
Flight Simulator Evaluation of Display Media Devices for Synthetic Vision Concepts

The Synthetic Vision Systems (SVS) Project of the National Aeronautics and Space Administration's (NASA) Aviation Safety Program (AvSP) is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft. To accomplish these safety and capacity improvements, the SVS concept is designed to provide a clear view of the world around the aircraft through the display of computer-generated imagery derived from an onboard database of terrain, obstacle, and airport information. Display media devices with which to implement SVS technology that have been evaluated so far within the Project include fixed field of view head up displays and head down Primary Flight Displays with pilot-selectable field of view. A simulation experiment was conducted comparing these display devices to a fixed field of view, unlimited field of regard, full color Helmet-Mounted Display system. Subject pilots flew a visual circling maneuver in IMC at a terrain-challenged airport. The data collected for this experiment is compared to past SVS research studies.
What explains schooling differences across countries

Abstract This paper provides a theory that explains the cross-country distribution of average years of schooling, as well as the so called human capital premium puzzle. In our theory, credit frictions as well as differences in access to public education, fertility and mortality turn out to be the key reasons why schooling differs across countries. Differences in growth rates and in wages are second order.
The chameleon groups of Richard J. Thompson: Automorphisms and dynamics

The automorphism groups of several of Thompson's countable groups of piecewise linear homeomorphisms of the line and circle are computed and it is shown that the outer automorphism groups of these groups are relatively small. These results can be interpreted as stability results for certain structures of PL functions on the circle. Machinery is developed to relate the structures on the circle to corresponding structures on the line.
Institutional choice, community, and struggle: a case study of forest co-management in Mexico.

Abstract Change in the commons remains poorly understood. This essay analyzes a comparative case study of community forestry in Mexico. In a primary case study, corruption in a community-owned logging business legitimates timber smuggling, and this situation contrasts with several forestry communities having internally-legitimate social institutions able to control such problems. A discussion assesses the institutional choice model for understanding change in the commons and contrasts it with an approach that views individual choices and actions as embedded in communities and cultures. The commons exists in a value-laden social context, and this requires a theory “thicker” than current versions of institutional choice.
The role of aggregation in estimating the effects of private school competition on student achievement

Abstract This paper investigates possible reasons for the disparity in results in the private school competition literature. In particular, the focus is on the data set, the grade range, and level of aggregation of the competition variable, and on the choice of OLS or IV estimation strategies. The results show that the size and significance of the competition variable depends on each of these attributes, although the grade range of the competition variable has a slightly smaller impact than the others. Private school competition does not have a consistently positive, significant effect on student achievement.
A LATENT FACTOR MODEL FOR SPATIAL DATA WITH INFORMATIVE MISSINGNESS.

A large amount of data is typically collected during a periodontal exam. Analyzing these data poses several challenges. Several types of measurements are taken at many locations throughout the mouth. These spatially-referenced data are a mix of binary and continuous responses, making joint modeling difficult. Also, most patients have missing teeth. Periodontal disease is a leading cause of tooth loss, so it is likely that the number and location of missing teeth informs about the patient’s periodontal health. In this paper we develop a multivariate spatial framework for these data which jointly models the binary and continuous responses as a function of a single latent spatial process representing general periodontal health. We also use the latent spatial process to model the location of missing teeth. We show using simulated and real data that exploiting spatial associations and jointly modeling the responses and locations of missing teeth mitigates the problems presented by these data.
Accurate characterization of error propagation in a highly parallel architecture

Errors caused by faults in a system manifest themselves in the output results in various patterns. These output patterns of erroneous data the nature of their propagation through the various modules of the system and their impact on the system are collectively referred to as error characerisics. This paper deals with efficient methods of obtaining these error characteristics. Both experimental and analytical approaches to the problem are considered and a probabilistic approach to this problem is proposed. The effectiveness of this approach with respect to the accuracy of results and amount of computation involved is discussed.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The X-Ray Properties of Optically Selected Galaxy Clusters

We stacked the X-ray data from the ROSAT All Sky Survey for over 4000 clusters selected from the 2MASS catalog and divided them into five richness classes. We detected excess X-ray emission over background at the center of the stacked images in all five richness bins. The interrelationships between the mass, X-ray temperature, and X-ray luminosity of the stacked clusters agree well with those derived from catalogs of X-ray clusters. Poisson variance in the number of galaxies occupying halos of a given mass leads to significant differences between the average richness at fixed mass and the average mass at fixed richness that we can model relatively easily using a simple model of the halo occupation distribution. These statistical effects probably explain recent results in which optically selected clusters lie on the same X-ray luminosity-temperature relations as local clusters but have lower optical richnesses than observed for local clusters with the same X-ray properties. When we further binned the clusters by redshift, we did not find significant redshift-dependent biases in the sense that the X-ray luminosities for massive clusters of fixed optical richness show little dependence on redshift beyond that expected from the effects of Poisson fluctuations. Our results demonstrate that stacking of RASS data from optically selected clusters can be a powerful test for biases in cluster-selection algorithms.
In situ particle size measurements using a two-color laser scattering technique.

We have developed a technique using light scattered from individual particles in the near-forward direction to measure particle size in the range of 10–200 μm. This technique uses the Mie scattering theory to relate the measured light intensity to particle size based on calibration techniques employing pinholes and water droplets of known size. We have applied a unique two-color optical arrangement to minimize the edge effect which can cause incorrect size measurements for particles that pass through the edge of the laser beam focal volume. In this paper we describe our experimental technique and the results of size measurements obtained with this technique for water droplets and pulverized coal particles.
An improved algorithm due to Laguerre for the solution of Kepler's equation

A root-finding method due to Laguerre (1834–1886) is applied to the solution of the Kepler problem. The speed of convergence of this method is compared with that of Newton's method and several higher-order Newton methods for the problem formulated in both conventional and universal variables and for both elliptic and hyperbolic orbits. In many thousands of trials the Laguerre method never failed to converge to the correct solution, even from exceptionally poor starting approximations. The non-local robustness and speed of convergence of the Laguerre method should make it the preferred method for the solution of Kepler's equation.
A NOVEL REDUCTION OF THE SIMPLE ASIAN OPTION AND LIE-GROUP INVARIANT SOLUTIONS

We develop the complete 6-dimensional classical symmetry group of the partial differential equation (PDE) that governs the fair price of a simple Asian option within a simple market model. The symmetries we expose include the 5-dimensional symmetry group partially noted by Rogers and Shi, and communicated implicitly by the change of numeraire arguments of Veceř (in which symmetries reduce the original 2 + 1 dimensional simple Asian option PDE to a 1 + 1 dimensional PDE). Going beyond this previous work, we expose a new 1-dimensional space of symmetries of the Asian PDE that cannot reasonably be found by inspection. We demonstrate that the new symmetry could be used to formulate a new, "nonlinear" derivative security that has a 1 + 1 dimensional PDE formulation. We indicate that this nonlinear security has a closed-form pricing formula similar to that of the Black–Scholes equation for a particular market dependent payoff, and show that hedging the short position in this particular exotic option is stable for all market parameters. We also demonstrate the patently Lie-algebraic method for obtaining the already well-known "Rogers–Shi–Veceř" reduction.
Supermarkets and Culture Clash: The Epistemological Role of Metaphors in Administrative Practice:

Metaphor analysis traditionally treats its subject as a figure of speech, that is, a purely literary device that can be replaced by literal language. However, recent work suggests that metaphors sh...
Average local ionization energies: Significance and applications

Summary The full significance and range of applications of Ī(r) continue to be explored. When computed on molecular surfaces, it is clearly an effective tool for interpreting and predicting reactivity toward electrophiles, in solution as well as in the gas phase. There are indications that this effectiveness can be increased by combining Ī S,min with V S, min , the most negative values of the electrostatic potential on the molecular surface. Ī S,min can also be used to characterize, and hence identify, certain types of chemical bonds. Finally, Ī(r) computed within the internal regions of atoms has been found to reflect the detailed distributions of the electrons. This suggests that analogous analyses of molecules might be fruitful; for example, it might be interesting to examine the variation of Ī(r) along internuclear axes. Such studies are in progress.
Noninformative nonparametric quantile estimation for simple random samples

For noninformative nonparametric estimation of finite population quantiles under simple random sampling, estimation based on the Polya posterior is similar to estimation based on the Bayesian approach developed by Ericson (J. Roy. Statist. Soc. Ser. B 31 (1969) 195) in that the Polya posterior distribution is the limit of Ericson's posterior distributions as the weight placed on the prior distribution diminishes. Furthermore, Polya posterior quantile estimates can be shown to be admissible under certain conditions. We demonstrate the admissibility of the sample median as an estimate of the population median under such a set of conditions. As with Ericson's Bayesian approach, Polya posterior-based interval estimates for population quantiles are asymptotically equivalent to the interval estimates obtained from standard frequentist approaches. In addition, for small to moderate sized populations, Polya posterior-based interval estimates for quantiles of a continuous characteristic of interest tend to agree with the standard frequentist interval estimates.
Quantum Monte Carlo for atoms, molecules and solids

The quantum Monte Carlo (QMC) method has become increasingly important for solution of the stationary Schrodinger equation for atoms, molecules and solids. The method has been shown to exhibit high accuracy that scales better with system size than other ab initio methods. Moreover, as typically implemented, QMC takes full advantage of parallel computing systems. These attributes for electronic structure calculations will be described, as well as recent applications that demonstrate the breadth of the QMC approach.
Vertebrates and the Permo-Triassic extinction

Abstract The fossil record of vertebrates in the late Paleozoic and early Mesozoic is investigated in an attemp to evaluate their participation in the Permo-Triassic faunal crisis. On the whole the record of the marine fishes is similar to that of marine invertebrates with a pronounced diversity minimum at the end of the Permian. On the other hand, the fresh-water and euryhaline fishes, together with the amphibians, seem to have experienced minimal diversity somewhat earlier in the Permian and apparently were on the increase at the Permo-Triassic boundary. The major peculiarity in the reptilian record is a great burst of both first appearances and apparent extinctions in the Dzhulfian Stage in Africa; local causes are suspected. Seemingly the Permo-Triassic faunal crisis was mainly a marine event for which a marine cause or causes should be sought.
A family of analog and mixed signal VLSI ASICs for NASA science missions

Abstract This paper presents several analog and mixed signal VLSI chips that have been successfully developed over the past several years at JHU/APL for space science missions. The chips have applications for spacecraft avionics and several types of instrumentation. The family of the chips include: the TRIO smart sensor multiplexed ADC chip for spacecraft/instrument avionics, the time-of-flight (TOF) chip for precise time interval measurement, the CFD chip for time discrimination, the energy chip for low-noise particle/photon measurement, a commandable discriminator pulse high analyzer, event accumulator, a radiation hardened voltage reference, an ADC and other. This paper addresses some design, radiation hard by design, design for testability, testing, and space qualification issues. The paper also briefly describes the spacecraft and instrument applications of these chips including: the NASA missions CASSINI, IMAGE, CONTOUR, MESSENGER, STEREO, PLUTO, oncoming funded missions MMS, JUNO, RBSP, as well as planned planetary and moon missions.
On the capacity of optical networks: A framework for comparing different transport architectures

We compare three optical transport network architectures - optical packet switching (OPS), optical flow switching (OFS), and optical burst switching (OBS) - based on a notion of network capacity as the set of exogenous traffic rates that can be stably supported by a network under its operational constraints. We characterize the capacity regions of the transport architectures, and show that the capacity region of OPS dominates that of OFS, and that the capacity region of OFS dominates that of OBS. We then apply these results to two important network topologies - bidirectional rings and Moore graphs - under uniform all-to-all traffic. Motivated by the incommensurate complexity/cost of comparable transport architectures, we also investigate the dependence of the relative capacity performance of the switching architectures on the number of switch ports per fiber at core nodes.
Hydroxymethylation and aminomethylation of 6-mercaptopurine and its derivatives

Labile aminomethyl and hydroxymethyl derivatives of 6-mercaptopurine (I) (6-MP) and S6-acyloxymethyl-6-MP have been converted to stable acetyloxymethyl derivatives by their reaction with acetic anhydride. Analysis of the reaction products and comparison of their 'H nmr spectra and hplc chromatograms with those of acetyloxymethyl derivatives of known structures suggested 1) that the aminomethyl derivatives of 6-MP were 7-substituted derivatives, 2) that the aminomethyl derivative of S6-acetyloxylmethyl-6-MP was a 9-derivative, 3) that the hydroxymethyl derivative of 6-MP was a mixture of 7-substituted and S6,3-disubstitu-ted derivatives, and 4) that the hydroxymethyl derivative of S6-pivaloyloxymethyl-6-MP was a 9-substituted derivative. In addition, a previously unreported dialkyl derivative of 6-MP VI was isolated from its reaction with aminomethylating agent and characterized. Analyses of the 'H nmr spectra and hplc chromatograms of the reaction of VI with acetic anhydride suggested that VI was a 1,7-disubstituted derivative.
Generalized phase space version of Langevin equations and associated Fokker-Planck equations

Generic Langevin equations are almost always given as first-order stochastic ordinary differential equations for the phase space variables of a system, with noise and damping terms in the equation of motion of every variable. In contrast, Langevin equations for mechanical systems with canonical position and momentum variables usually include the noise and damping forces only in the equations for the momentum variables. In this paper we derive Langevin equations and associated Fokker-Planck equations for mechanical systems that include noise and damping terms in the equations of motion for all of the canonical variables. The derivation is done by comparing a distinctive derivation of a phase space Fokker-Planck equation, given by Langer, to the usual derivation relating Langevin equations to their associated Fokker-Planck equations. The resulting equations have simple reductions to overdamped and underdamped limits. They should prove useful for numerical simulation of systems in contact with a heat bath, since they provide one additional parameter that can be used, for example, to control the rate of approach to thermal equilibrium. The paper concludes with a brief description of the modification of Kramers' result for the escape rate from a metastable well, using the new form of the Fokker-Planck equation obtained here.
P(RNCH2CH2)3N-Catalyzed 1,2-Addition Reactions of Activated Allylic Synthons

Activated allylic compounds of the type RCH:CHCH2Z (Z = CN, CO2Me) react efficiently with aromatic aldehydes in the presence of 20−40 mol % of P(R‘NCH2CH2)3N at −94 to −63 °C. Both R = H and R = Me lead exclusively to α-addition products. When R = H and Z = CN, an allylic transposition occurs to afford a Baylis−Hillman product as the only product.
Impacts of object-oriented technologies: seven years of SEL studies

This paper examines the premise that object-oriented technology (OOT) is the most significant technology ever examined by the Software Engineering Laboratory. The evolution of the use of OOT in the Software Engineering Laboratory (SEL) 'Experience Factory' is described in terms of the SEL's original expectations, focusing on how successive generations of projects have used OOT. General conclusions are drawn on how the usage of the technology has evolved in this environment.
Highly selective asymmetric acetate aldol reactions of an N-acetyl thiazolidinethione reagent.

A highly diastereoselective acetate aldol reaction that uses a tert-leucine-derived thiazolidinethione auxiliary and dichlorophenylborane has been developed. The reaction proceeds in excellent yields and with high diastereoselectivities (drs range from 9.5:1 to >100:1).
Formation and utility of oxasilacyclopentenes derived from functionalized alkynes.

Oxasilacyclopentenes were shown to be synthetically useful masked allylic alcohols constructed in high yields and regioselectivities from terminal and internal alkynes. Several functional groups were shown to be tolerated utilizing silver-catalyzed silacyclopropenation of alkynes. In situ insertion of various carbonyl compounds into silacyclopropenes afforded regioselective formation of oxasilacyclopentenes. Elaboration of the oxasilacyclopentenes displayed the synthetic utility of these substrates. Both diastereoselective hydrogenation and Diels−Alder reactions utilizing the vinylsilane functionality demonstrated the reactivity and synthetic utility of oxasilacyclopentenes.
Structural instability of the core

Let σ be a q-rule, where any coalition of size q, from the society of size n, is decisive. Let w(n,q)= 2q-n+1 and let W be a smooth ‘policy space’ of dimension w. Let U(W)N be the space of all smooth profiles on W, endowed with the Whitney topology. It is shown that there exists an ‘instability dimension’ w∗(σ) with 2≦w∗(σ)≦w(n,q) such that: 1. (i) if w≧w∗(σ), and W has no boundary, then the core of σ is empty for a dense set of profiles in U(W)N (i.e., almost always), 2. (ii) if w≧w∗(σ)+1, and W has a boundary, then the core of σ is empty, almost always, 3. (iii) if w≧w∗(σ)+1 then the cycle set is dense in W, almost always, 4. (iv) if w≧w∗(σ)+2 then the cycle set is also path connected, almost always. The method of proof is first of all to show that if a point belongs to the core, then certain generalized symmetry conditions in terms of ‘pivotal’ coalitions of size 2q−n must be satisfied. Secondly, it is shown that these symmetry conditions can almost never be satisfied when either W has empty boundary and is of dimension w(n,q) or when W has non-empty boundary and is of dimension w(n,q)+1.
Relativistic Magnetohydrodynamics with Application to Gamma-Ray Burst Outflows. II. Semianalytic Super-Alfvénic Solutions

We present exact radially self-similar solutions of special relativistic magnetohydrodynamics representing hot super-Alfv?nic outflows from strongly magnetized, rotating compact objects. We argue that such outflows can plausibly arise in gamma-ray burst (GRB) sources and demonstrate that, just as in the case of the trans-Alfv?nic flows considered in the companion paper, they can attain Lorentz factors that correspond to a rough equipartition between the Poynting and kinetic energy fluxes and become cylindrically collimated on scales compatible with GRB observations. As in the trans-Alfv?nic case, the initial acceleration is thermal, but, in contrast to the solutions presented in the companion paper, part of the enthalpy flux is transformed into Poynting flux during this phase. The subsequent, magnetically dominated acceleration can be significantly less rapid than in trans-Alfv?nic flows.
Wing/store flutter with nonlinear pylon stiffness

Recent wind tunnel tests and analytical studies show that a store mounted on a pylon with 'soft' pitch stiffness provides substantial increase in flutter speed of fighter aircraft and reduces dependency of flutter on mass and inertia of the store. This concept, termed the decoupler pylon, utilizes a low-frequency control system to maintain pitch alignment of the store during maneuvers and changing flight conditions. Under rapidly changing transient loads, however, the alignment control system may allow the store to momentarily bottom against a relatively stiff backup structure in which case the pylon stiffness acts as a hardening nonlinear spring. Such structural nonlinearities are known to affect not only the flutter speed but also the basic behavior of the instability. This paper examines the influence of pylon stiffness nonlinearities on the flutter characteristics of wing-mounted external stores.
Novel approach to the ansamycin antibiotics macbecin I and herbimycin A. A formal total synthesis of (+)-macbecin I

Abstract The asymmetric syntheses of 25 and 29, which constitutes the C(3)–C(15) segment of the stereochemically complex ansa chain of (+)-macbecin I (1) and herbimycin A (2), respectively, have been achieved. The approach features the furan-hydropyranone transformation 9→10 followed by stereoselective introduction of substituents onto the conformationally-biased hydropyran ring of 10 to give 17. Extension of the side chain of 17 led to the pivotal intermediate 22, which was elaborated into 25 and 29. Refunctionalization of the carboxyl terminus of 25 furnished 26, which was converted into 32 by stereoselective addition of an aryllithium to the lactol 30. The structure of 32 was established by its conversion into 34, which was an advanced intermediate in Baker's total synthesis of 1, thereby completing a formal synthesis of optically pure (+)-macbecin I (1).
Channel-Unit Hydraulics on a Pool-Riffle Channel

Three riffles, two runs, and a pool were used to examine variations in water surface gradient and average velocity over a discharge range of 1.8-19.1 m3/s under conditions of stable channel geometry. Water surface gradient was measured using staff gages, and average velocity was measured using a salt tracer and conductivity probes. The discharge range during the study includes average annual low flow and peak flow. Gradient decreased over all channel units as discharge increased, but the rate of decrease was greater over runs and pools. Velocity data indicate consistent rates of increase among channel units with increasing discharge. Linear plots indicate that the rate of change in water surface and velocity for the channel units decreases at discharges greater than 8-10 m3/s, which corresponds to the transition from intermediate-scale to small-scale relative submergence. As grain roughness effectively decreases, larger patterns of flow convergence and divergence generated by form roughness increase. Decl...
Dispersion Relations for Production Amplitudes

>The Logunov dispersion relation for production amplitudes is discussed. It is shown that this relation is invalid, i.e., that the production amplitude has complex singularities when regarded as a function of the Logunov variables. The reaction pi + N yields pi + pi + N is analyzed by perturbation theory, and it is found that 4 of the 5 independent variables of the reaction are ignored in the Logunov calculations. The singularities in the Logunov production amplitudes are demonstrated in Feynman diagrams. (T.F.H.)
Colloid cysts of the third ventricle: ultrastructural features are compatible with endodermal derivation

The histogenesis of colloid cyst of the third ventricle remains unsettled. Ultrastructural and immunohistochemical analyses have suggested the following possible origins: (a) neuroepithelium, including paraphysis, ependyma, choroid plexus and tela chorioidea; and (b) endoderm, including respiratory and enteric epithelium. This report describes the ultrastructural features of the lining epithelium in four cases of colloid cyst. Six distinct cell types were recognized: (1) ciliated cells with occasional abnormal cilia; (2) non-ciliated cells with microvilli coated with granulofibrillary material; (3) goblet cells showing discharge of secretory granules; (4) basal cells with prominent tonofilaments and desmosomes; (5) basal-located cells with elongated electron-lucent cytoplasm and scattered membrane-bound dense-core granules (150–350 nm); and (6) small undifferentiated cells with scanty organelles. Junctional complexes were present in the former four cell types but absent in the latter two. The types of epithelial cells and their topographic distribution within the epithelium are both very similar to those of normal respiratory epithelium and to the lining epithelium of intraspinal bronchogenic cyst. The observations made in the present study are compatible with the hypothesis that colloid cysts of the third ventricle originate from the endoderm, most likely the respiratory epithelium.
A voltage scalable advanced DFM RAM with accelerated screening for low power SoC platform

The advanced-DFM RAM provides the solution for the limitation of SRAM voltage scaling down and the countermeasure of the process fluctuations. The characteristics of this RAM are the voltage scalability(@0.6 V operation) with wide operating margin and the reliability of long data retention time. The memory cell consists of 2 cell/bit with the complementary dynamic memory operation and has the 1 cell/bit test mode for the accelerated screening against the marginal cells. The GND bitline pre-charge sensing scheme and SSW (sense synchronized write) peripheral circuit technologies are also adopted for the low voltage and FV controllable SoC which will be strongly required from the many kinds of applications. This RAM supports the DFM functions with both good cell/bit for advanced process technologies and the voltage scalable SoC memory platform.
Paying to Learn: The Effect of Financial Incentives on Elementary School Test Scores

Abstract Policymakers and academics are increasingly interested in applying financial incentives to individuals in education. This paper presents evidence from a pay-for-performance program taking place in Coshocton, Ohio. Since 2004, Coshocton has provided cash payments to students in grades 3 through 6 for successful completion of their standardized testing. Coshocton determined eligibility for the program using randomization. Using this randomization, this paper identifies the effects of the program on students' academic behavior. We find that math scores improved about 0.15 standard deviations but that reading, social science, and science test scores did not improve.
The Geometry of¶(Super) Conformal Quantum Mechanics

N-particle quantum mechanics described by a sigma model with an N-dimensional target space with torsion is considered. It is shown that an SL(2,ℝ) conformal symmetry exists if and only if the geometry admits a homothetic Killing vector D a δ a whose associated one-form D a dX a is closed. Further, the SL(2,ℝ) can always be extended to Osp(1|2) superconformal symmetry, with a suitable choice of torsion, by the addition of N real fermions. Extension to SU(1,1|1) requires a complex structure I and a holomorphic U(1) isometry D a I a b δ b . Conditions for extension to the superconformal group D(2,1;α), which involve a triplet of complex structures and SU(2)×SU(2) isometries, are derived. Examples are given.
A perspective on nanocluster catalysis: polyoxoanion and (n-C4H9)4N+ stabilized Ir(0)∼300 nanocluster ‘soluble heterogeneous catalysts’

Abstract Following a review of the background terms, definitions and key literature necessary to understand the rapidly developing and promising area of nanocluster catalysis, the recent report of polyoxoanion-stabilized Ir(0)∼190–450 (hereafter Ir(0)∼300) nanocluster catalysts is reviewed. Specifically, the experimental observations relating to three principle questions concerning these soluble-oxide-supported, Ir(0)∼300 nanocluster catalysts are reviewed: (i) their catalytic activity (in a prototypical structure-insensitive reaction, cyclohexene hydrogenation); (ii) their lifetime; and (iii) their thermal stability, each in direct comparison to three established heterogeneous Ir(0) catalysts [7.9% dispersed 1% Ir(0) γ- Al 2 O 3 , Exxon's 80% dispersed 1% Ir η- Al 2 O 3 , and a low surface area Ir(0) precipitate]. In addition, observations of WVI to WV· reduction of the polyoxoanion by Ir(0)∼300 and H2 are summarized, results which provide the first soluble-oxide version of the well known spillover of hydrogen in heterogeneous catalysis.
Cyclic Oxidation Behavior of Aluminide, Platinum Modified Aluminide, and MCrAlY Coatings on GTD-111

Cyclic oxidation behavior of aluminide, platinum modified aluminide, and MCrAlY coating has been investigated at three temperatures. Aluminide and platinum modified coating were deposited on GTD 111 material using an outward diffusion process. CoCrAlY coating was applied on GTD-111 by Electron Beam Physical Vapor Deposition (EB-PVD). The oxidation behavior of these coatings is characterized by weight change measurements and by the variation of {beta} phase present in the coating. The platinum modified aluminide coating exhibited the highest resistance to oxide scale spallation (weight loss) during cyclic oxidation testing. Metallographic techniques were used to determine the amount of {beta} phase and the aluminum content in a coating as a function of cycles. Cyclic oxidation life of these coatings is discussed in terms of the residual {beta} and aluminum content present in the coating after exposure. These results have been used to calibrate and validate a coating life model (COATLIFE) developed at the Material Center for Combustion Turbines (MCCT).
Design of Functionalized Room-Temperature Ionic Liquid-Based Materials for CO2 Separations and Selective Blocking of Hazardous Chemical Vapors

The design and synthesis of several new types of functionalized room-temperature ionic liquids (RTILs), ionic polymers based on RTILs (i.e., poly(RTIL)s), poly(RTIL)-RTIL solid-liquid composites, and gelled RTIL systems for gas separations and reactive vapor transport applications are presented. The design concepts behind these new RTIL materials are discussed in the context of first, CO2 removal from CH4 and N2 for natural gas purification and greenhouse gas reduction, respectively; and second selective blocking or sorption of chemical warfare agent simulant and toxic industrial compound vapors from water vapor for protection applications. The role of the RTIL components and their unique properties in these two separations areas will be highlighted.
External Radiation of Brain Metastases From Renal Carcinoma: A Retrospective Study of 119 Patients From the M. D. Anderson Cancer Center

Purpose: Approximately 10% of patients with metastatic renal cell carcinoma are diagnosed with brain metastases. Most of these patients receive palliative radiotherapy and die of progressive brain metastatic disease. This retrospective study examines the M. D. Anderson Cancer Center experience with such patients who received only whole brain radiation therapy ( WBRT) . Methods and Materials: Records of 200 patients with brain metastases from renal carcinoma who were treated at M. D. Anderson Cancer Center between 1976 and 1993 were reviewed. Of these patients, 119 received WBRT only and constitute the basis of this study. Different prognostic factors were analyzed. Results: Overall median survival time from diagnosis of the brain metastases was 4.4 months. Multiple brain tumors were treated in 70 patients (58.8% ) who had a survival of 3.0 months compared with 4.4 months for patients having a single brain metastasis (p = 0.043). Among 117 patients the causes of death were neurologic in 90 (76% ), systemic cancer in 19 ( 16% ), and unknown in 9 (8% ). Survival rates at 6 months, 1 year, and 2 years, were 33.6,16.8, and 5.9%, respectively. Patients in whom brain metastases were diagnosed synchronously with a renal primary (n = 24) had a median survival time of 3.4 months compared with 3.2 months for those 95 who were diagnosed metachronously (p < 0.79, NS). In the Cox multivariate analysis of 13 possible prognostic factors, only a single brain metastasis @ = 0.0329), lack of distant metastases at the time of diagnosis @ = 0.0056)) and tumor diameter zz 2 cm (p < 0.0016) were statistically significant. Conclusion: These unsatisfactory results with WBRT suggest that more aggressive approaches, such as surgery or radlosurgery should be applied whenever possible. 0 1997 Elsevier Science Inc.