cssi/SciSciGPT-SciSciNet huggingface dataset:
Type-based hot swapping of running modules

While dynamic linking has become an integral part of the run-time execution of modern programming languages, there is increasing recognition of the need for support for hot swapping of running modules, particularly in long-lived server applications. The interesting challenge for such a facility is to allow the new module to change the types exported by the original module, while preserving type safety. This paper describes a type-based approach to hot swapping running modules. The approach is based on a reflective mechanism for dynamically adding type sharing constraints to the type system, realized by programmer-defined version adapters in the run-time.
Homogeneous catalysis. A transition metal based catalyst for the Mukaiyama crossed-aldol reaction and catalyst deactivation by electron transfer.

Abstract The cationic complex [Ru(salen)(NO)H 2 O]SbF 6 is intrinsically a powerful catalyst for the Mukaiyama crossed-aldol reaction at 25°C in nitromethane solutions and at very low catalyst loadings but, for some reactions, electron transfer from the silyl enol ether to the ruthenium catalyst can occur which leads to catalyst deactivation.
Signal Reconstruction from Frame and Sampling Erasures

We give some new methods for perfect reconstruction from frame and sampling erasures in a small number of steps. By bridging an erasure set we mean replacing the erased Fourier coefficients of a function with respect to a frame by appropriate linear combinations of the non-erased coefficients. We prove that if a minimal redundancy condition is satisfied bridging can always be done to make the reduced error operator nilpotent of index 2 using a bridge set of indices no larger than the cardinality of the erasure set. This results in perfect reconstruction of the erased coefficients. We also obtain a new formula for the inverse of an invertible partial reconstruction operator. This leads to a second method of perfect reconstruction from frame and sampling erasures in a small number of steps. This gives an alternative to the bridging method for many (but not all) cases. The methods we use employ matrix techniques only of the order of the cardinality of the erasure set, and are applicable to rather large finite erasure sets for infinite frames and sampling schemes as well as for finite frame theory. These methods are usually more efficient than inverting the frame operator for the remaining coefficients because the size of the erasure set is usually much smaller than the dimension of the underlying Hilbert space. Some new classification theorems for frames are obtained and some new methods of measuring redundancy are introduced based on our bridging theory.
Host country's governance and the size of foreign investors

Abstract We find that smaller foreign investors are more sensitive to the quality of host country's governance than larger investors. This may be the case as smaller foreign firms have less bargaining power and are more sensitive to uncertainty and risk.
Iridium-Catalyzed Allylic Fluorination of Trichloroacetimidates

A rapid allylic fluorination method utilizing trichloroacetimidatesinconjunctionwithaniridiumcatalyst has been developed. The reaction is conducted at room temperature under ambient air and relies on Et3N 3 3HF reagent to provide branched allylic fluorides with complete regioselectivity. This high-yielding reaction can be con- ducted on a multigram scale and shows considerable func- tional group tolerance. The use of ( 18 F)KF 3 Kryptofix allowed 18 F incorporation in 10 min.
A Robust Structural Stress Parameter for Evaluation of Multiaxial Fatigue of Weldments

In this paper, the applicability of a new mesh-insensitive structural stress method is examined for the evaluation of multiaxial fatigue behaviors in welded joints. The mesh-insensitive structural stress method proves to be effective in characterizing stress concentration effects in multi-axial fatigue of welded components. In seeking an effective structural stress based fatigue parameter, some well-known published test data were analyzed. These include those published by researchers, e.g., from the Electric Power Research Intitute (EPRI), the Fraunhofer-Institute for Structural Durability (LBF), the University of Illinois at Urbana-Champaign (UIUC), and the Welding Institute (TWI) under bending, torsion, and in-phase and out-of-phase loading combinations. An effective structural stress parameter has then been formulated in a form of a proposed modified Gough's ellipse for considering both in-phase and out-of-phase multiaxial loading conditions. The aforementioned multiaxial fatigue data from a total of five independent sources can be effectively correlated with a structural stress based parameter presented in this paper, without introducing any other material-related empirical parameters. The present method is rather simple to use for day-to-day finite element based fatigue evaluation of welded joints in actual structures subjected to multiaxial loading conditions.
String theory on parallelizable PP-waves

The most general parallelizable pp-wave backgrounds which are non-dilatonic solutions in the NS-NS sector of type IIA and IIB string theories are considered. We demonstrate that parallelizable pp-wave backgrounds are necessarily homogeneous plane-waves, and that a large class of homogeneous plane-waves are parallelizable, stating the necessary conditions. Such plane-waves can be classified according to the number of preserved supersymmetries. In type IIA, these include backgrounds preserving 16, 18, 20, 22 and 24 supercharges, while in the IIB case they preserve 16, 20, 24 or 28 supercharges. An intriguing property of parallelizable pp-wave backgrounds is that the bosonic part of these solutions are invariant under T-duality, while the number of supercharges might change under T-duality. Due to their {alpha}{prime} exactness, they provide interesting backgrounds for studying string theory. Quantization of string modes, their compactification and behavior under T-duality are studied. In addition, we consider BPS Dp-branes, and show that these Dp-branes can be classified in terms of the locations of their world volumes with respect to the background H-field.
Sliding mode control of a DC distributed solar microgrid

This paper proposes a standalone distributed photovoltaic system which includes two independently controlled solar power sources, a battery storage and a resistive load. Each of the PV panels consist of cascaded DC-DC boost converters controlled through two independent sliding mode controllers. The design and simulation of the supervisory controller are also discussed. First, maximum power point tracking (MPPT) control strategy is introduced to maximize the simultaneous energy harvesting from both renewable sources. Then, according to the power generation available at each renewable source and the state of charge in the battery, four contingencies will be considered in the supervisory controller. Moreover, power converters interfacing the source and common DC bus will be controlled as voltage sources under a Pi-sliding mode controller. Numerical simulations demonstrate accurate operation of the supervisory controller and functionality of the MPPT algorithm in each operating condition.
Flowing afterglow studies of temperature dependencies for electron dissociative recombination of HCNH+, CH3CNH+ and CH3CH2CNH+ and their symmetrical proton-bound dimers

Abstract A study has been made using a variable temperature flowing afterglow Langmuir probe technique (VT-FALP) to determine the equilibrium temperature dependencies of the dissociative electron-ion recombination of the protonated cyanide ions (RCNH+, where R=H, CH3 and C2H5) and their symmetrical proton-bound dimers (RCNH+NCR). The power law temperature dependencies of the recombination coefficients, αe, over the temperature range 180 to 600 K for the protonated ions are αe(T)(cm3 s−1)=3.5±0.5×10−7 (300/T)1.38 for HCNH+, αe(T)=3.4±0.5×10−7 (300/T)1.03 for CH3CNH+, and αe(T)=4.6±0.7×10−7 (300/T)0.81 for CH3CH2CNH+. The equivalent values for the proton-bound dimers are αe(T)(cm3 s−1)=2.4±0.4×10−6(300/T)0.5 for (HCN)2H+ to αe(T)=2.8±0.4×10−6(300/T)0.5 for (CH3CN)2H+, and αe(T)=2.3±0.3×10−6(300/T)0.5 for (CH3CH2CN)2H+. The relevance of these data to molecular synthesis in the interstellar medium and the Titan ionosphere are discussed.
Meromorphy of the rank one unit root L-function revisited

We demonstrate that Wan's alternate description of Dwork's unit root L-function in the rank one case may be modified to give a proof of p-adic meromorphy that is classical, eliminating the need to study sequences of uniform meromorphic functions.
INNOVATION: IMPLICATIONS FOR GOODS AND SERVICES

The concepts of goods and services innovation have been discussed extensively in the academic literature. The research has been both selective (dealing with specific attributes such as R&D, process innovation, measurement of innovation, and use of information technology) and specific (dealing with specific industries such as banking, insurance, biotechnology, nanotechnology). This paper examines the concept of innovation in the context of "goods" and "services." The comparisons made between the two sectors are based on three distinct areas — definition, process, measurement. This paper also presents a conceptual framework showing the interactions among the various variables inherent in some of the distinct areas. Previous papers have highlighted the differences in innovation between goods and services. What is missing is how the intervening variables invoked in the discussions are themselves related to one another. While this paper reinforces the conclusions reached by other studies with regard to innovation, it specifically highlights on an aggregate scale, the areas in which goods and services differ. Future research should take these distinctions into account, not as single items but collectively. It is critical to consider how these innovation variables interact with one another in the context of goods and services. Perhaps the most significant contribution of this paper is in its presentation of the framework for understanding the innovation process as it relates to the goods and services sectors.
Efficient synthesis of (±)-N-BOC-exo-2-(methoxycarbonyl)-7-Azabicyclo[2.2.1]heptane, a versatile intermediate for the synthesis of epibatidine and epiboxidine

N-BOC-exo-2-(methoxycarbonyl)-7-azabicyclo[2.2.1]heptane, an important intermediate for the synthesis of epibatidine and its analogs was efficiently synthesized from N-BOC-exo-2-(methoxycarbonyl)-7-azabicyclo[2.2.1]hepta-2,5-diene (5) via hydrogenation followed by reductive dehalogenation or via hydrodehalogenation followed by epimerization. The diene 5 was obtained by Diels-Alder reaction.
Coral growth rate: Variation with depth

Abstract Light and temperature are two of the most important physical factors affecting rates of growth of reef corals. The effect of light has been determined by X-radiographic measurement of long-term growth rates for 89 colonies of the coral Montastrea annularis collected over a 27.5−m depth range from St. Croix, U.S. Virgin Islands. These measurements, in conjunction with measurements of skeletal density, have established that M. annularis calcifies most rapidly at intermediate depths, and they have confirmed the identification of two distinct populations within this important frame-building species.
Subsurface eddies in the Arctic ocean

Abstract In March and April of 1972, four transient undercurrents were associated with eddies at depths between 50 and 300 m in the Arctic Ocean. The velocity profile was parabolic with a maximum of 40 cm s−1 at 150m. Two of the eddies were anticyclonic and two, cyclonic. The eddies persisted at least several days, they were 10–20 km in diameter, and were separated by 20–50 km. The subsurface currents in the eddies were swifter than those in the upper mixed layer, with little correlation between the two levels. The eddies are believed to have their origin in the instability of the basic baroclinic current.
Single nucleon emission in relativistic nucleus-nucleus reactions

Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parametrized formulas developed by those authors.
The effect of geography and demography on outcomes of emergency department patients in rural Uganda

controls to have ever consumed alcohol (aOR, 1.64; 95% CI, 1.29e2.07). Both past drinking (aOR, 1.70; 95% CI, 1.24e2.35) or current drinking (aOR, 1.51; 95% CI, 1.10e2.07) were associated with breast cancer risk. A doseeresponse relationship was observed for years of drinking (P trend < 0.001), with each additional year contributing to a 2% increase in risk. Among women with family history of breast cancer (aOR, 2.81; 95% CI, 1.09e7.24), the relationship between alcohol drinking and breast cancer was stronger than that among women without the history (aOR, 1.55; 95% CI, 1.21e1.99). Summary/Conclusion: We found a positive relationship between alcohol consumption and breast cancer risk among African women, although it was heterogeneous across three countries. Alcohol drinking may be becoming increasingly common among African women, and this modifiable risk factor should be addressed in breast cancer prevention programs in Africa.
Selective deoximation using alumina supported potassium permanganate

Abstract Ketoximes are converted to the parent ketones in good yields when treated with potassium permanganate supported on neutral alumina (ASPP). An optimized procedure has been developed, the simple work-up minimizes loss of product and oximes have been selectively oxidized in the presence of alkenes.
Multilateralism and Regionalism from an American Perspective: Parallels and Contrasts with the Langhammer Vision

The paper discusses various milestones in the process of multilateral trade negotiations, pinpoints current challenges facing the world trading order, and proposes possible ways out of the persistent impasse. Hufbauer argues that the success of the multilateral approach is at least partly because the GATT departed from the strictly unconditional definition of the most-favored nation (MFN) rule in the late 1970s already. Regional agreements such as NAFTA complemented, rather than hindered, multilateral trade liberalization in the past. The political economy of further multilateral liberalization has become increasingly complicated since countries such as Brazil, China, and India have emerged as relevant players. Against this backdrop, Hufbauer expects regionalism to become the strongest vehicle for delivering liberalization in the future. This could still leave a bright future for the WTO as a “house of plurilaterals”, i.e., agreements on specific issues such as services liberalization with conditional MFN treatment of varying membership.
Equiangular tight frames from Paley tournaments

Abstract We prove the existence of equiangular tight frames having n = 2 d - 1 elements drawn from either C d or C d - 1 whenever n is either 2 k - 1 for k ∈ N , or a power of a prime such that n ≡ 3 mod 4 . We also find a simple explicit expression for the prime power case by establishing a connection to a 2 d -element equiangular tight frame based on quadratic residues.
Synthesis of pyrrolo[2,1-f][1,2,4]triazine congeners of nucleic acid purines via the N-amination of 2-substituted pyrroles

The synthesis of several new 4-mono- and 2,4-disubstituted pyrrolo- [2,1-f][1,2,4]triazines is described. Key 1-aminopyrrole-2-carbonitrile intermediates (3) and (15) were obtained by N-amination of the corres- ponding pyrrole-2-carboxaldehyde followed by CHO → CN conversion with either hydroxylamine-O-sulfonic acid for (3) or O-mesitylenesulfonyl- hydroxylamine for (15). Cyclization of (3) or (15) with a variety of amidine reagents or, after conversion of (3) to its corresponding amide, base-catalyzed annulation completed the synthesis of the title products
Output Feedback Stabilization of Linear Systems With Actuator Saturation

The note presents a method for designing an output feedback law that stabilizes a linear system subject to actuator saturation with a large domain of attraction. This method applies to general linear systems including strictly unstable ones. A nonlinear output feedback controller is first expressed in the form of a quasi-LPV system. Conditions under which the closed-loop system is locally asymptotically stable are then established in terms of the coefficient matrices of the controller. The design of the controller (coefficient matrices) that maximizes an estimate of the domain of attraction is then formulated and solved as an optimization problem with LMI constraints
The Solution of the modified Helmholtz equation in a wedge and an application to diffusion-limited coalescence

Abstract The general representation of the solution of the modified Helmholtz equation, q xx ( x , y )+ q yy ( x , y )−4 β 2 q ( x , y )=0, has been recently constructed. Here we apply this representation in the wedge 0≤ x ≤ y ≤∞ and use this solution to find the explicit steady-state of diffusion-limited coalescence, A + A ⇌ A , on the half-line, with a trap-source at the origin.
Optical Vectorial Vortex Coronagraphs using Liquid Crystal Polymers: theory, manufacturing and laboratory demonstration.

In this paper, after briefly reviewing the theory of vectorial vortices, we describe our technological approach to generating the necessary phase helix, and report results obtained with the first optical vectorial vortex coronagraph (OVVC) in the laboratory. To implement the geometrical phase ramp, we make use of Liquid Crystal Polymers (LCP), which we believe to be the most efficient technological path to quickly synthesize optical vectorial vortices of virtually any topological charge. With the first prototype device of topological charge 2, a maximum peak-to-peak attenuation of 1.4×10^(-2) and a residual light level of 3×10^(-5) at an angular separation of 3.5 λ/d (at which point our current noise floor is reached) have been obtained at a wavelength of 1.55 μm. These results demonstrate the validity of using space-variant birefringence distributions to generate a new family of coronagraphs usable in natural unpolarized light, opening a path to high performance coronagraphs that are achromatic and have low-sensitivity to low-order wavefront aberrations.
Chiral extension of lattice gauge theory

Abstract Two approaches are presented to coupling explicit Goldstone modes to N f flavors of massless quarks preserving exact SU ( N f ) × SU ( N f ) chiral symmetry on the lattice. The first approach is a generalization a chiral extension to QCD (aka XQCD) proposed by Brower, Shen and Tan consistent with the Ginsparg-Wilson relation. The second approach based on the Callan, Coleman, Wess and Zumino coset construction has a real determinant at zero quark axial coupling, g A = 0.
Energetic electrons in solar flares as viewed in X-rays

Abstract Hard X-ray observations provide the most direct diagnostic we have of the suprathermal electrons and the hottest thermal plasma present in solar flares. The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) is obtaining the most comprehensive observations of individual solar flares ever available in hard X-rays. For the first time, high-resolution spectra are available for a large number of flares that accurately display the spectral shape and its evolution and, in many cases, allow us to identify the transition from the bremsstrahlung X-rays produced by suprathermal electrons to the bremsstrahlung at lower energies emitted by thermal plasma. Also, for the first time, images can be produced in arbitrary energy bands above 3–4 keV, and spectra of distinct imaged components can be obtained. I review what we have learned from RHESSI observations about flare suprathermal electron distributions and their evolution. Next, I present computations of the energy deposited by these suprathermal electrons in individual flares and compare this with the energy contained in the hot thermal plasma. I point out unsolved problems in deducing both suprathermal electron distributions and the energy content of the thermal plasma, and discuss possible solutions. Finally, I present evidence that electron acceleration is associated with magnetic reconnection in the corona.
Long-term memory stabilized by noise-induced rehearsal

Cortical networks can maintain memories for decades despite the short lifetime of synaptic strengths. Can a neural network store long-lasting memories in unstable synapses? Here, we study the effects of ongoing spike-timing-dependent plasticity (STDP) on the stability of memory patterns stored in synapses of an attractor neural network. We show that certain classes of STDP rules can stabilize all stored memory patterns despite a short lifetime of synapses. In our model, unstructured neural noise, after passing through the recurrent network connections, carries the imprint of all memory patterns in temporal correlations. STDP, combined with these correlations, leads to reinforcement of all stored patterns, even those that are never explicitly visited. Our findings may provide the functional reason for irregular spiking displayed by cortical neurons and justify models of system memory consolidation. Therefore, we propose that irregular neural activity is the feature that helps cortical networks maintain stable connections.
Dependence of Inner Accretion Disk Stress on Parameters: The Schwarzschild Case

We explore the parameter dependence of inner disk stress in black hole accretion by contrasting the results of a number of simulations, all employing three-dimensional general relativistic MHD in a Schwarzschild spacetime. Five of these simulations were performed with the intrinsically conservative code HARM3D, which allows careful regulation of the disk aspect ratio, H/R; our simulations span a range in H/R from 0.06 to 0.17. We contrast these simulations with two previously reported simulations in a Schwarzschild spacetime in order to investigate possible dependence of the inner disk stress on magnetic topology. In all cases, much care was devoted to technical issues: ensuring adequate resolution and azimuthal extent, and averaging only over those time periods when the accretion flow is in approximate inflow equilibrium. We find that the time-averaged radial dependence of fluid-frame electromagnetic stress is almost completely independent of both disk thickness and poloidal magnetic topology. It rises smoothly inward at all radii (exhibiting no feature associated with the innermost stable circular orbit, ISCO) until just outside the event horizon, where the stress plummets to zero. Reynolds stress can also be significant near the ISCO and in the plunging region; the magnitude of this stress, however, depends on both disk thickness and magnetic topology. The two stresses combine to make the net angular momentum accreted per unit rest mass 7%-15% less than the angular momentum of the ISCO.
Regional economies and market integration

Abstract The effects of regional differences in population and per capita human capital on income levels and economic growth rates are examined. Sufficient human capital heterogeneity can reduce specialization and inhibit the formation of large markets. The model contains static and dynamic agglomeration economies of market participation. Thus human capital heterogeneity can lower per capita income, and economic growth rates. Over time human capital accumulation reduces heterogeneity, thereby producing market expansion. Numerical solutions indicate that the first regions to integrate into a larger market are the higher human capital regions.
Dynamical equations of spinning particles. Feynman's proof☆

Abstract We discuss the extension of Feynman's derivation of the equation of motion to the case of spinning particles. We show that a spinning particle interacts only with the electromagnetic and gravitational fields. In the absence of the electromagnetic interactions, we rederive Papapetrou's equations for spinning particles in the background of the conformal gravity. We also find that the effect of spin coupled to non-constant electromagnetic fields leads to further corrections to the Lorentz force equations. Some discussions of these results are given at the end.
Bridging of macrodithionolactones to bicyclic systems. Synthesis and modeling of oxapolycyclic frameworks

A new reaction involving bridging of macrodithionolactones to bicyclic systems is described. A series of macrodiolides was prepared and converted to the requisite macrodithionolactones. The latter substrates were induced to undergo bridging across the macrocyclic ring by exposure to sodium naphthalenide, leading to stable bicyclic systems upon addition of methyl iodide. The mixed thioketals so obtained were converted to a number of saturated or unsaturated bicyclic or polycyclic systems by removal of the sulfurs. The stereochemistry of bridging follows the relative energy of the cis and trans products rather than the conformational preferences of the macrocycles. This is confirmed by MM2 calculations and X-ray crystal structure determinations
Digital health communities: The effect of their motivation mechanisms

Health-related online social networks are starting to play a role in many people's daily lives by enabling them to monitor their diet and motivating them to change their lifestyles. These social networks provide different motivation mechanisms. However, little research has been done on the effectiveness of these motivation mechanisms. This research analyzes data collected from a digital health community to examine what mechanisms can help motivate people. The results suggest that there is a high level of correlation between users' exercise activities and their participation in these digital health communities. This research benefits the digital health communities by providing insights into the design of motivation mechanisms.
Radio Identification of the X-Ray Jet in the z = 4.3 Quasar GB 1508+5714

The recent discovery of an X-ray jet in the z = 4.3 quasar GB 1508+5714 by Yuan et al. and Siemiginowska et al. prompted a search for its radio counterpart. Here, we report the successful discovery of faint radio emission from the jet at 1.4 GHz using archival Very Large Array data. The X-ray emission is best interpreted as inverse Compton (IC) emission off the cosmic microwave background (CMB) as discussed by the previous investigators. In this scenario, its high X-ray-to-radio monochromatic luminosity ratio, compared to previously detected IC/CMB X-ray jets at lower redshift, is a natural consequence of its high redshift.
Space Shuffle: A Scalable, Flexible, and High-Bandwidth Data Center Network

Data center applications require the network to be scalable and bandwidth-rich. Current data center network architectures often use rigid topologies to increase network bandwidth. A major limitation is that they can hardly support incremental network growth. Recent studies propose to use random interconnects to provide growth flexibility. However, routing on a random topology suffers from control and data plane scalability problems, because routing decisions require global information and forwarding state cannot be aggregated. In this paper, we design a novel flexible data center network architecture, Space Shuffle (S2), which applies greedy routing on multiple ring spaces to achieve high-throughput, scalability, and flexibility. The proposed greedy routing protocol of S2 effectively exploits the path diversity of densely connected topologies and enables key-based routing. Extensive experimental studies show that S2 provides high bisectional bandwidth and throughput, near-optimal routing path lengths, extremely small forwarding state, fairness among concurrent data flows, and resiliency to network failures.
HydraNet: network support for scaling of large-scale services

Abstract With the explosive growth of demand for services on the Internet, the networking infrastructure (routers, protocols, servers) is under considerable stress. Mechanisms are needed for current and future IP services to scale in a client-transparent way. We present H YDRA N ET , an infrastructure that allows to dynamically distribute IP services by placing service agents (caching agents, mirrors, replicas) that are under the server's control at strategic points in the internetwork. H YDRA N ET is based on replicating transport-level service access points (TCP or UDP ports in the case of IP) for transparent distribution or replication of IP services. Measurements on a local testbed show that the overhead of our scheme is small. This form of service access point replication is widely applicable. We use H YDRA N ET to implement H YDRA W EB , a system for Web server replication to realize intelligent, client-transparent, Web caching. Similarly, H YDRA N ET can be used to implement highly fault-tolerant servers or application-level gateways.
Synthesis of a helicopter nonlinear flight controller using approximate model inversion

This paper considers synthesis of a helicopter full authority flight controller using an approximate inversion of the nonlinear model of the vehicle. Based on the natural time scale separation between position and attitude dynamics of the vehicle, the vehicle attitudes are treated as pseudo-command variables. In order to simplify the controller, approximations to the body axes forces are used in the controller calculations. The first approximation involves neglecting the cyclic and pedal control force terms, and the second approximation involves neglecting the body x- and y-axis force components in the controller calculations. The impact of these approximations on the performance of the closed-loop system is evaluated through nonlinear simulation of the Apache helicopter using typical command maneuvers.
Steroid modulation of the hypothalamic-pituitary system in the secretion of reproductive hormones.

The results of a study of the inhibition and amplification of pituitary responses to the synthetic hypothalamic hormones LRF and TRF during estrogen and progesterone experiments in normal and hypogonadal women are reported. Serum luteinizing hormone (LH) follicle stimulating hormone (FSH) prolactin (PRL) and estradiol (E2) and progesterone were measured by radioimmunoassay. In 10 hypogonadal subjects there was a significant decrease in PRL levels during infusion of pharmacological doses of E2 followed by a significant increase in PRL release lasting several hours. Small doses of ethinyl estradiol (EE) induced a significant elevation of serum PRL levels with 1 week of treatment and a continued rise within 3-4 weeks to more than 3 times the initial concentration. The LH and FSH levels fell progressively to premenopausal levels at Week 4. With large doses of EE a more rapid increase of PRL levels was found and a higher elevation. Data indicate that pituitary sensitivity and reserve are modulated by estrogen and progesterone. The sensitivity appeared to be blunted. Results of experiments indicate that the pituitary gland represents a major feedback site for the regulation of optimal delivery of tropic hormones of reproduction via steroid signals. Estrogen provides a time and dose-related positive feedback loop in the augmentation of pituitary PRL secretion. Progesterone in low concentration has a facilitatory action on the pituitary response to LRF depending on prior exposure to estrogen in optimal amount and duration. Progesterone in high concentration in the midluteal phase lessens the estrogen-augmented pituitary response to LRF.
Log-concavity of a mixture of beta distributions☆

Abstract We provide a sufficient condition for a mixture of Beta distributions to have log-concave density. This is true whenever the Beta distributions to be mixed together have constant parameter sum and the mixing weights are themselves log-concave. The result has applications in economics and statistics, which we present in the last section.
Hard X-ray Emission from the NGC?5044 Group

Observations made with the Rossi X-ray Timing Explorer Proportional Counter Array (PCA) to constrain the hard X-ray emission in the NGC 5044 group are reported here. Modeling a combined PCA and ROSAT position sensitive proportional counter spectrum with a 0.5-15 keV energy range shows excess hard emission above 4 keV. Addition of a power-law component with a spectral index of 2.6-2.8 and a luminosity of 2.6 x 10{sup 42} erg s{sup -1} within 700 kpc in the observed energy band removes these residuals. Thus, there is a detection of a significant non-thermal component that is 32% of the total X-ray emission. Point-source emission makes up at most 14% of the non-thermal emission from the NGC 5044 group. Therefore, the diffuse, point-source-subtracted, non-thermal component is (2.2-3.0) x 10{sup 42} erg s{sup -1}. The cosmic-ray electron energy density is 3.6 x 10{sup -12} erg cm{sup -3} and the average magnetic field is 0.034 {mu}G in the largest radio emitting region. The ratio of cosmic-ray electron energy density to magnetic field energy density, {approx}2.5 x 10{sup 4}, is significantly out of equipartition and is therefore atypical of radio lobes. In addition, the group's small size and low non-thermal energy density strongly contradicts themore » size-energy relationship found for radio lobes. Thus, it is unlikely related to the active galaxy and is most likely a relic of the merger. The energy in cosmic rays and magnetic field is consistent with simulations of cosmic-ray acceleration by merger shocks.« less
Sensitivity of propulsion system selection to Space Station Freedom performance requirements

The selection of the propulsion system for the Space Station (SS) is reassessed. The propulsion system consists of two distinct elements. The first of these combusts gaseous oxygen and hydrogen produced from water electrolysis, to maintain the SS altitude and perform higher thrust maneuvers for backup attitude control, collision avoidance, and other contingencies. The second consists of gas resistojets, which augment altitude maintenance. The results of a parametric comparison of the life cycle costs of this electrolysis/resistojet propulsion with those of other system options, carried out over a range of probable performance requirements, confirmed the baseline superiority of the SS propulsion system for most anticipated conditions. However, relative costs among impulse requirements vary so much that major changes in the design conditions may warrant implementation of another system (such as hydrazine with water resistojets).
Tesseral Harmonics of the Geopotential and Corrections to Station Coordinates

Tesseral harmonics of geopotential and corrections to Baker-Nunn camera station coordinates
Observed punishment spillover effects: a laboratory investigation of behavior in a social dilemma

Punishment has been shown to be an effective reinforcement mechanism. Intentional or not, punishment will likely generate spillover effects that extend beyond one’s immediate decision environment, and these spillovers are not as well understood. We seek to understand these secondary spillover effects in a controlled lab setting using a standard social dilemma: the voluntary contributions mechanism. We find that spillovers occur when others observe punishment outside their own social dilemma. However, the direction of the spillover effect depends crucially on personal punishment history and whether one is personally exempt from punishment or not.
Origin and evolution of Castalia Macula, an anomalous young depression on Europa

Europa's Castalia Macula region was comprehensively imaged by the Galileo spacecraft on several orbits, at both local and regional resolutions and with different illumination geometries. Using these datasets we have mapped and identified the different geological units within the Castalia area, and derived digital elevation models (DEMs) of the topography within most of the Castalia Macula region. Using these data sets in combination allows us to map the geology and topography of this area in greater detail than perhaps any other site on Europa. Castalia Macula consists of unusually dark and reddish material, most of which is confined to a broad topographic depression 350 m deep located between two large uplifted domes 900 and 750 m high, to the north and south, respectively. The preservation of topography at the bottom of Castalia Macula indicates that dark material initially filled the depression to a certain depth but was subsequently removed via drainage, resulting in a dark stain up to the original equipotential surface. Superposition and topographic relationships suggest that the Castalia Macula plains deposit formed prior to uplift of both domes, and at least two distinct episodes of chaos formation have occurred near and on top of the northern dome. It appears that Castalia Macula is comparatively young and was active relatively recently, therefore it could provide an ideal place to sample material that has recently been erupted from the subsurface, and may have been in communication with Europa's ocean. These factors combine to make Castalia Macula a very attractive site for a future Europa lander.
A procedure for optimizing development decisions

This paper addresses the problem of organizing data and formulating questions to be answered for the purpose of making planning and development decisions. The problem is separated into five distinct parts. Each part is discussed in the context of the planning process and each leads logically to the optimization of development decisions. The five parts are goal definition, establishment of criteria, criteria weighting, alternative rating and alternative ranking. The feature of making development decisions which distinguishes them from other optimization problems is what has been called 'fuzziness'. In any realistic problem formulation, the criteria are not precisely defined; they are fuzzy. The relative importance of each criterion is also fuzzy. Indeed, even when one attempts to rate a particular possible solution, he must deal with fuzzy information. The technique proposed in the paper accounts for this uncertainty in all aspects of the problem and yields probabilistic answers. Thus, when various alternative solutions are proposed for a development problem, the technique yields a probabilistic ranking of the alternatives. Sharper results are obtained if less uncertainty is present in certain parts of the data. However, even in the presence of great uncertainty, realistic problem solutions are obtained. Alternative solutions are rated independent of all others and only after the (fuzzy) ratings are complete are comparative rankings accomplished. Throughout the procedure the realistic uncertainties remain a prominent feature of the procedure.
Experimental Results of Adaptive Periodic Disturbance Cancellation in a High Performance Magnetic Disk Drive

This paper considers the implementation of an adaptive algorithm for periodic disturbance cancellation. It is shown that the maximum rate of adaptation can be calculated precisely based on measurements of the system's frequency response. The response of the closed-loop system to additional disturbances can also be computed on that basis. The results are verified experimentally on a high track density magnetic disk drive. Excellent matching between the theoretical and experimental results is observed. An improved method is also proposed that leads to faster convergence of the adaptive algorithm and better disturbance rejection capabilities. The results of this paper significantly enhance the ability of the control engineer to design and analyze adaptive feedforward algorithms for a variety of applications where periodic disturbances are encountered.
Novel photoresist design based on electrophilic aromatic substitution

A new approach to resist materials that exhibit chemical amplification is based on systems comprised of three structural units at least one of which is polymeric: (a) an aromatic moiety such as poly(4-hydroxystyrene), Novolac, or other aromatic compounds which are susceptible to electrophilic aromatic substitution; (b) a latent electrophile which may be polyfunctional and, in the case of this study, is a carbocation precursor; (c) a material which generates strong acid upon irradiation. Exposure of a film containing these three structural components affords a latent image of acid dispersed in the polymer matrix. In a subsequent baking step, the photogenerated acid reacts with the latent electrophile releasing a very reactive carbocationic species which becomes bound to the aromatic moiety. As one of the components of the resist is polymeric and multifunctional, the result is a rapid increase in molecular weight due to branching and crosslinking of the chains. In terms of imaging, this process translates into the formation of a negative image of the mask although under some conditions a positive image may also be produced. The system shows a very high sensitivity and can provide high resolution images devoid of distortion due to the absence of swelling during development.
Avoiding the risk of responsibility by seeking uncertainty: Responsibility aversion and preference for indirect agency when choosing for others

Abstract Uncertainty-seeking behavior is currently understood as the result of loss aversion which motivates a preference for the possibility to avoid or lessen an otherwise sure loss. However, when choosing among negative options on behalf of others, we offer responsibility aversion as another possible motive for uncertainty-seeking behavior. Within our conceptual model, responsibility aversion is defined as the preference to minimize one's causal role in outcome generation. Compared to certain options, uncertain options lessen the decision maker's causal role in outcome generation because the outcomes are partially determined by chance. The presence of chance increases indirect agency on behalf of the decision maker and lessens his or her perceived risk of responsibility. The results of five studies support a responsibility aversion motivation behind uncertainty-seeking behavior.
Interfacial cracks in plates : a three-dimensional numerical investigation

Abstract The three-dimensional field at a crack front in a bimaterial interface is investigated in order to identify relevant fracture parameters in thin plate laboratory specimens. Existence of plane stress K -dominance is necessary for the proper analysis of experimental data, which can be obtained directly from the crack-tip field by optical methods. The analysis of the three-dimensional structure of the crack-tip field presented here is performed in relation to the three-point bend specimen geometry used in the experiments described in Lee and Rosakis (1993), Interfacial cracks in plates: an experimental investigation (in preparation). It is well known that the three-dimensional field at the vicinity of a crack in a plate composed of a homogeneous material extends over a half-plate thickness from the crack front. However in a bimaterial fracture specimen, in addition to the singular field at the crack tip, mismatch of material properties along the interface induces a strip of three-dimensionality extending along the bimaterial interface ahead of the crack tip. The extent of the three-dimensional zone and a critical discussion of the zone of K -dominance are presented. The relation between the stress intensity factors in the remote plane stress K -field and the stress intensity factors inside the near-tip plane strain K -field is also derived by means of a separate boundary-layer type of numerical analysis. Finally, a means of scaling the results obtained by experimentation in thin plate specimens of a specific thickness-to-plate specimens of any thickness is proposed.
Expected characteristics of cometary meteorites

— Recent developments in our understanding of comets provide insights into the topic of cometary meteorites. These developments include the identification of comet-asteroid transition objects (such as 4015 Wilson-Harrington and 3200 Phaethon), information on the composition of cometary solids, and new ideas on the collisional history of Jupiter-family comets. In this work, we revisit this question, and we conclude that comets do indeed yield macroscopic meteorites, which either have not been found or have not been recognized. We also consider the expected characteristics of cometary meteorites, with an emphasis on those that may help identify and differentiate them from other types of meteorites. If cometary meteorites have preserved the main characteristics of cometary dust, the mineralogy would be dominated by highly unequilibrated anhydrous silicates, and the chemistry would be nearly chondritic but with a high abundance of C and N. On the other hand, if an unknown process produced extensive aqueous alteration in the material that formed cometary meteorites, they would resemble (or could even be) CI carbonaceous chondrites. We do not expect cometary meteorites to have chondrules. So far, no single meteorite looks unequivocally cometary. However, we have identified xenoliths in ordinary chondrite regolith breccias that meet most of our criteria for a cometary origin and deserve further study.
The absorption spectra of the phenoxyl radical in solid argon

Abstract Vacuum ultraviolet photolysis of phenol, phenol-d 6 and anisole during condensation with excess argon at 20 K has produced and trapped the phenoxyl radical as evidenced by structured absorptions at 397.2 and 628.1 nm. A broad photosensitive 416 ± 2 nm band is tentatively assigned to the phenol cation.
Diverse alkanones by catalytic carbon insertion into the formyl C-H bond. Concise access to the natural precursor of achyrofuran.

Over a century ago, the first reactions of diazomethane with aldehydes delivered methyl ketones. In the interim, aldehydes have been homologated with trimethylsilyldiazomethane, diazoacetates, and aryldiazomethanes, on rare occasion with catalysis. This work describes a mild procedure for convergent ketone assembly from nonstabilized diazoalkanes, including examples of chiral ketone synthesis with disubstituted (internal) nucleophiles. The method’s remarkable tolerance to steric crowding is showcased in a simple approach to achyrofuran, a complex dibenzofuran.
Three new probabilistic models for dependency parsing: an exploration

After presenting a novel O(n3) parsing algorithm for dependency grammar, we develop three contrasting ways to stochasticize it. We propose (a) a lexical affinity model where words struggle to modify each other, (b) a sense tagging model where words fluctuate randomly in their selectional preferences, and (c) a generative model where the speaker fleshes out each word's syntactic and conceptual structure without regard to the implications for the hearer. We also give preliminary empirical results from evaluating the three models' parsing performance on annotated Wall Street Journal training text (derived from the Penn Treebank). In these results, the generative model performs significantly better than the others, and does about equally well at assigning part-of-speech tags.