cssi/SciSciGPT-SciSciNet huggingface dataset:
Method for Measuring High Temperature Spectral Emissivity of Nonconducting Materials

A new method, based upon the integral blackbody technique, for measuring the normal spectral emissivity of nonconducting materials at high temperatures is described. A small cylindrical sample (5.21 mm diam x 9.53 mm length) is mounted within a long, thin-walled, metallic tube that is heated by the passage of direct current. Lateral holes in the tube wall permit an optical system to alternately detect the spectral radiance from the sample and from a cavity when both are at the same temperature. The major sources of error have been analyzed and the overall performance evaluated. Data are presented on a series of new, commercial ceramics, silicon carbide and silicon nitride, for the spectral region 1.5-15 jim and the temperature range 1300-1900 K. Temperature levels to 3000 K have been achieved with a specially configured graphite composite sample. These results indicate that the method provides a useful tool for studying the effects of fabrication processes and environmental influences on the radiative properties of materials at high temperatures.
Diastereo- and Enantioselective Ruthenium Catalyzed Hydrohydroxyalkylation of 2-Silyl-Butadienes: Carbonyl syn- Crotylation from the Alcohol Oxidation Level

Exposure of alcohols 2a–2j to 2-silyl-butadienes in the presence of ruthenium complexes modified by (R)-SEGPHOS or (R)-DM-SEGPHOS results in redox-triggered generation of allylruthenium–aldehyde pairs, which combine to form products of carbonyl crotylation 4a–4j in the absence of stoichiometric byproducts and with high levels of syn-diastereo- and enantioselectivity. In the presence of isopropanol under otherwise identical conditions, aldehydes 3a–3j are converted to an equivalent set of adducts 4a–4j. Whereas reactions conducted using conventional heating require 48 h, microwave irradiation enables full conversion in only 4 h. Finally, as illustrated in the conversion of adduct 4a to compounds 6a and 6b, diastereoselective hydroboration–Suzuki cross-coupling with aryl and vinyl halides followed by Fleming–Tamao oxidation enables generation of anti,syn-stereotriads found in numerous polyketide natural products.
Direct, Enantioselective Synthesis of Pyrroloindolines and Indolines From Simple Indole Derivatives.

The (R)-BINOL·SnCl_4-catalyzed formal (3+2) cycloaddition between 3-substituted indoles and benzyl 2-trifluoroacetamidoacrylate is a direct, enantioselective method to prepare pyrroloindolines from simple starting materials. However, under the originally disclosed conditions, the pyrroloindolines are formed as mixtures of diastereomers, typically in the range of 3:1 to 5:1 favoring the exo-product. The poor diastereoselectivity detracts from the synthetic utility of the reaction. We report here that use of methyl 2-trifluoroacetamidoacrylate in conjunction with (R)-3,3′-dichloro-BINOL·SnCl_4 provides the corresponding pyrroloindolines with improved diastereoselectivity (typically ≥10:1). Guided by mechanistic studies, a one-flask synthesis of enantioenriched indolines by in situ reduction of a persistent iminium ion is also described.
Autonomous safeing and fault protection for the New Horizons mission to Pluto

Abstract The New Horizons spacecraft now bound for the planet Pluto and beyond to the Kuiper belt was successfully launched on January 19, 2006. The New Horizons spacecraft has backup devices for its major electronic modules, and also has a heavily cross-strapped architecture that makes the spacecraft fully tolerant of almost all single-point failures. The onboard fault protection system detects failure of a component and autonomously activates the backup system as necessary. The onboard safeing system detects anomalies in spacecraft performance, such as attitude control errors or propulsion system problems, and then autonomously places the spacecraft into one of two safe states.
The Mass Of The Coma Cluster From Weak Lensing In The Sloan Digital Sky Survey

We present a weak lensing analysis of the Coma Cluster using the Sloan Digital Sky Survey (SDSS) Data Release Five. Complete imaging of a {approx} 200 square degree region is used to measure the tangential shear of this cluster. The shear is fit to an NFW model and we find a virial radius of r{sub 200} = 1.99{sup +0.21}{sub -0.22}h{sup -1}Mpc which corresponds to a virial mass of M{sub 200} = 1.88{sup +0.65}{sub -0.56} x 10{sup 15}h{sup -1}M{circle_dot}. We additionally compare our weak lensing measurement to the virial mass derived using dynamical techniques, and find they are in agreement. This is the lowest redshift, largest angle weak lensing measurement of an individual cluster to date.
Study on the Cure Kinetic Behavior of Thermosetting Polyurethane Solids and Foams: Effect of Temperature, Density, and Carbon Nanofiber

Cure kinetic behavior was studied for both thermosetting polyurethane (PU) solids and foams. The effects of cure temperature, foam density, and carbon nanofiber (CNF) contents were examined. Cure studies were performed experimentally by measuring the evolution of complex shear modulus as a function of time using an advanced polymer analyzer operating in dynamic shear mode. Isothermal cure behavior of PU solid and foams was investigated at four different temperatures, namely, 25°C, 45°C, 60°C, and 80°C and at three different amounts of CNF, namely, 0.01%, 0.05%, and 0.1% by weight. The cure data were analyzed by using an autocatalytic cure kinetic model. The cure behavior of both solid and foam was found to be temperature dependent. Addition of CNF was also found to affect the cure behavior of the PU foam. It was observed that the PU foam with 0.1% CNF shows the highest polymerization reaction compared with the neat foam. It was also observed that the reaction rate constants follow an Arrhenius dependence on temperature, whereas the reaction orders remain fairly constant. A simple predictive model using the reaction orders indicated that the maximum cure reaction rate was occurred at 37.5% conversion.
Models and techniques

In the situations typically encountered in the social sciences the methodology of traditional statistics is neither a good description of data analysis practice nor a good prescription to arrive at satisfactory summaries of the data. On the other hand the traditional statistical techniques are excellent data analysis tools, and statistical models are useful devices that can be used to develop and evaluate data analysis techniques. These general considerations are applied in this paper to evaluate the usefulness of techniques such as multidimensional scaling and correspondence analysis.
Answer to August 2014 Photo Quiz

Answer: a dicotyledonous plant seed. A differential identification of the object initially included both a small intestinal fluke and a cross-section of a nematode, among other possibilities. However, close inspection of the object did not reveal internal structures, such as reproductive and
Games with strategic complements and substitutes

This paper studies games with both strategic substitutes and strategic complements, and more generally, games with strategic heterogeneity (GSH). Such games may behave differently from either games with strategic complements or games with strategic substitutes. Under mild assumptions (on one or two players only), the equilibrium set in a GSH is totally unordered (no two equilibria are comparable in the standard product order). Moreover, under mild assumptions (on one player only), parameterized GSH do not allow decreasing equilibrium selections. In general, this cannot be strengthened to conclude increasing selections. Monotone comparative statics results are presented for games in which some players exhibit strategic substitutes and others exhibit strategic complements. For two-player games with linearly ordered strategy spaces, there is a characterization. More generally, there are sufficient conditions. The conditions apply only to players exhibiting strategic substitutes; no additional conditions are needed for players with strategic complements. Several examples highlight the results.
Recent advances in carbon nanospheres: synthetic routes and applications

Carbon-based materials are the most popular material types in both fundamental research and industrial applications, partly because of their well-controlled nano-morphologies. In the past two decades, we have witnessed a number of breakthroughs in carbon research: fullerenes, carbon nanotubes, and more recently graphene. Nowadays, carbon nanospheres are attracting more and more attention worldwide due to their excellent performance in various fields: drug delivery, heterogeneous catalysis, encapsulation of support and electrode materials. Actually, spherical carbon is an old material, whereas controlling carbon spheres in the nanometer range is a recent story. In the past 5 years, it has become possible to precisely control the particle size, surface area, pore size, chemical composition, and dispersity of carbon nanospheres. Toward this end, a number of synthetic strategies are emerging, such as hydrothermal carbonization of biomass-based resources, extended Stober synthesis, and organic–organic self-assembly via different binding methods. In this feature article, we summarize recent routes for carbon nanospheres and briefly touch on their applications to shed light on the potential of this field. Throughout this article, a special emphasis is placed on the possible modulation of spherical structures at the nanoscale, and we wish to inspire many more designs and applications of carbon nanostructures in the near future.
Environmental Enforcement and Compliance: Lessons from Pollution, Safety, and Tax Settings

Environmental monitoring and enforcement are controversial and incompletely understood. This survey reviews what we do and do not know about the overall effectiveness, as well as the cost effectiveness, of pollution monitoring and enforcement. We ask five key questions: What do environmental monitoring and enforcement actions look like in the real world? How do we assess environmental compliance and deterrence? Do environmental monitoring and enforcement actions get results? How, why, and when do inspections and sanctions achieve compliance and reduce pollution? And, what do the answers to the preceding questions tell us about designing and implementing more effective and more cost effective public policies for the environment? A key contribution is drawing lessons from diverse sources, including insights from theoretical, empirical, and experimental contributions in environmental, tax, and safety settings. We conclude that traditional environmental monitoring and enforcement actions generate important deterrence effects. However, there are limits to such deterrence, and deterrence itself cannot fully explain all patterns of environmental behavior. Encouraging compliance requires both traditional tools and additional tools.
Constrained inversion of seismic refraction data using the controlled random search

When designing models for 2-D seismic refraction inversion, it is desirable to frame the models as polygonal units with well-defined geophysical characteristics. Such inversion is strongly nonlinear. Random search methods for nonlinear inversion, such as the genetic algorithm and simulated annealing, have received much attention in recent years. Such methods are well suited when the model space is large and contains multiple global minima to the misfit function. Constraints are necessary in the automatic construction of polygonal models. Controlled random search (CRS) is a member of this class of methods that has not been widely exploited. CRS is an iterative process based on the polytope algorithm, which offers a means by which linear constraints may be used. The CRS samples large model spaces, resists local minima, and can find multiple global minima. A new program has been developed for inversion of 2-D seismic refraction data which incorporates geologic compatibility constraints for polygon-based models. A theoretical example and practical applications of this technique to environmental investigations illustrate its characteristics.
Total synthesis of irciniastatin A (Psymberin).

The total synthesis of (+)-iriciniastatin A (psymberin) is reported in 19 steps and 6% overall yield. Key reactions include a highly convergent enolsilane−oxocarbenium ion union to generate the C8−C25 fragment and a late-stage coupling of a hemiaminal and acid chloride to complete the synthesis.
International institutions and market expectations: Stock price responses to the WTO ruling on the 2002 U.S. steel tariffs

Many scholars assert that international institutions have little power to enforce laws, punish offenders, or force compliance. Others stress that international institutions are important actors, specifically in the regulation of international trade. In this paper, I show that the recent trade dispute over U.S. steel protection provides us with a critical case to evaluate the role of the World Trade Organization in settling trade disputes and specifically stabilizing expectations of market actors over future steel policy. I argue that stock prices can serve as an important tool in answering these questions. In an empirical analysis using daily steel stock prices, I find that during the 2002 WTO steel case, the WTO dispute mechanism helped market actors stabilize expectations of future trade policy.
A novel synthetic route to 3-sulfenyl- and 3-selenylindoles by n-Bu4NI-induced electrophilic cyclization.

3-Sulfenyl- and 3-selenylindoles are prepared in excellent yields by the palladium/copper-catalyzed crossing coupling of N,N-dialkyl-o-iodoanilines and terminal alkynes, followed by electrophilic cyclization with arylsulfenyl chlorides and arylselenyl chlorides in the presence of a stoichiometric amount of n-Bu4NI.
On managing the human factors engineering of hybrid production systems

In the transition toward total automation, contemporary manufacturing systems are predominantly composed of production equipment that is neither completely manual or automated. The development of these systems, identified as hybrid production systems, employ and integrate the capacities of human operators with intelligent machines. It is argued that human activities in hybrid automated systems are critical in achieving productivity gains. Given this importance, hybrid systems must be designed to optimize production. Optimal human factors engineering is possible only when engineers and their management are aware of the technical challenges, created by hybrid systems, and the range of options available for meeting these challenges. The authors describe these challenges and their possible solutions, specifically targeted to the management of engineering and technology-based organizations. >
Issues in the Processing of Cuprate Ceramic Superconductors

A number of the important issues in the processing of dense, superconducting ceramics are addressed and illustrated with examples drawn from our studies of the processing of yttrium barium cuprate. Among the phenomena affecting the attainment of dense, fully superconducting materials are those common to the processing of other ceramics, namely, control of composition, prevention of microcracking, adequate time for the decomposition, and escape of intermediaries prior to surface densification (the so-called “binder burn-off” problem). Additional requirements include the necessity to ensure complete oxygenation throughout the microstructure for full volume superconductivity and the control of texture development for maximizing the attainable transport critical current density. On the basis of the processing issues described, it is concluded that the optimum microstructure is one having finescale, interconnected porosity (to ensure escape of carbonate-like species and subsequent, rapid oxygenation) with a fine grain size (∼1 μm) to avoid microcracking.
Physical activity as a factor in the action of dietary restriction on aging: Effects in Fischer 344 rats

Dietary restriction (DR) slows the rate of aging in laboratory rodents but the mechanism of action is unknown. DR is known to induce beneficial effects in a variety of tissues and organ systems. DR also maintains high levels of physical activity over the life span. We tested the hypothesis that lifelong physical activity is an important component of the anti-aging action of DR. Male specific pathogen-free Fischer 344 rats were divided into 4 groups at 6 weeks of age: A: fed ad libitum; AE: fed ad libitum and in cages with running wheels; B: fed 60% ad libitum; BE: fed 60% ad libitum and in cages with running wheels. Running activity and spontaneous cage activity were measured over 24 hours and over the life span. Metabolic rate was measured indirectly by analysis of air entering and leaving cages. AE rats exhibited low levels of running activity and ran very little beyond 6 months of age. In contrast, BE rats sustained high running levels even after all A and AE rats had died. High levels of wheel running did not decrease spontaneous cage activity. Median life span (50% survival) was in the order A = AE < B < BE. Ten percent survival was in the order A = AE < B = BE. BE rats had greatest median life span and also highest specific metabolic rate. Exercise and DR altered pathology: At death BE rats had a high incidence of cardiomyopathy, whereas A and AE rats had high incidence of chronic nephropathy and pituitary tumors. The data indicate that increased physical activity is probably not an important factor in the action of DR on aging.
Ground state and spectral properties across a charge density wave transition in a triangular lattice spinless fermion model

We study ground state properties and particle excitation spectra across a commensurate charge density wave transition in a system of strongly interacting fermions, using series expansion methods and mean-field theory. We consider a 1/3-filled system of spinless fermions on a triangular lattice, with hopping parameter $t$, nearest-neighbor repulsion $V$, and a sublattice dependent chemical potential ${\ensuremath{\mu}}_{s}$. The phase transition is found to be first order for ${\ensuremath{\mu}}_{s}=0$, but becomes continuous with increasing ${\ensuremath{\mu}}_{s}$. The particle and hole excitation spectra exhibit dramatic changes in the vicinity of the phase transitions and in the charge density wave ordered phase. We discuss the relevance of this study to the pinball Fermi liquid phase postulated theoretically in earlier studies as well as to various strongly correlated triangular lattice materials.
Cluster of High-Powered Racks Within a Raised-Floor Computer Data Center: Effect of Perforated Tile Flow Distribution on Rack Inlet Air Temperatures

This paper focuses on the effect on inlet rack air temperatures as a result of maldistribution of airflows exiting the perforated tiles located adjacent to the fronts of the racks. The flow distribution exiting the perforated tiles was generated from a computational fluid dynamics (CFD) tool called Tileflow (Trademark of Innovative Research, Inc.). Both raised floor heights and perforated tile free area were varied in order to explore the effect on rack inlet temperatures. The flow distribution exiting the perforated tiles was used as boundary conditions to the above floor CFD model. A CFD model was generated for the room with electronic equipment installed on a raised floor. Fourty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide × 13.4 m long. Since the arrangement of the racks in the data center was symmetric only one-half of the data center was modeled. The numerical modeling for above the raised floor was performed using a commercially available finite control volume computer code called Flotherm (Trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.© 2003 ASME
Randomized online graph coloring

Abstract We study the problem of coloring graphs in an online manner. The only known deterministic online graph coloring algorithm with a sublinear performance function was found by Lovasz, Saks, and Trotter, (Discrete Math. 75 (1989) , 319–325). Their algorithm colors graphs of chromatic number χ with no more than (2χn) log ∗ n colors, where n is the number of vertices. They point out that the performance can be improved slightly for graphs with bounded chromatic number. For three-chromatic graphs the number of colors used, for example, is O( n log log log n log log n ) . We show that randomization helps in coloring graphs online. We present a simple randomized online algorithm to color graphs with expected number of colors O(2 χ χ 2 n (χ−2) (χ−1) ( log n) 1 (χ−1) ) . For three-colorable graphs the expected number of colors our algorithm uses is O( n log n ) . All our algorithms run in polynomial time. It is interesting to note that our algorithm compares well with the best known polynomial time offline algorithms. For instance, the best polynomial time algorithm known for three-colorable graphs, due to Avrim Blum, uses O(n 3 8 poly-log (n)) colors (in “Proceedings, 31st Annual Sympos. Found. Comput. Sci., 1990,” pp. 554–562). We also prove a lower bound of Ω(( 1 (χ − 1) )(( log n (12(χ + 1)) ) − 1) χ−1 ) for the randomized model. No lower bound for the randomized model was previously known. For bounded χ, our result improves even the best known lower bound for the deterministic case: Ω(( log n log log n ) χ−1 ) , due to Noga Alon (personal communication, September 1989).
Stellar Collisions and Ultracompact X-Ray Binary Formation

We report the results of new SPH calculations of parabolic collisions between a subgiant or slightly evolved red giant star and a neutron star (NS). Such collisions are likely to provide the dominant formation mechanism for ultracompact X-ray binaries (UCXBs) observed today in old globular clusters. In particular, we compute collisions of a 1.4 M☉ NS with realistically modeled parent stars of initial masses 0.8 and 0.9 M☉, each at three different evolutionary stages (corresponding to three different core masses mc and radii R). The distance of closest approach for the initial orbit varies from rp = 0.04R (nearly head-on) to 1.3R (grazing). These collisions lead to the formation of a tight binary, composed of the NS and the subgiant or red giant core, embedded in an extremely diffuse common envelope (CE) typically of mass ~0.1-0.3 M☉. Our calculations follow the binary for many hundreds of orbits, ensuring that the orbital parameters we determine at the end of the calculations are close to final. Some of the fluid initially in the giant's envelope, from 0.003 to 0.023 M☉ in the cases we considered, is left bound to the NS. The eccentricities of the resulting binaries range from about 0.2 for our most grazing collision to about 0.9 for the nearly head-on cases. In almost all the cases we consider, gravitational radiation alone will cause sufficiently fast orbital decay to form a UCXB within a Hubble time, and often on a much shorter timescale. Our hydrodynamics code implements the recent SPH equations of motion derived with a variational approach by Springel & Hernquist and by Monaghan. Numerical noise is reduced by enforcing an analytic constraint equation that relates the smoothing lengths and densities of SPH particles. We present tests of these new methods to help demonstrate their improved accuracy.
When is the commutant of a Bol loop a subloop

A left Bol loop is a loop satisfying x(y(xz)) = (x(yx))z. The commutant of a loop is the set of elements which commute with all elements of the loop. In a finite Bol loop of odd order or of order 2k, k odd, the commutant is a subloop. We investigate conditions under which the commutant of a Bol loop is not a subloop. In a finite Bol loop of order relatively prime to 3, the commutant generates an abelian group of order dividing the order of the loop. This generalizes a well-known result for Moufang loops. After describing all extensions of a loop K such that K is in the left and middle nuclei of the resulting loop, we show how to construct classes of Bol loops with a non-subloop commutant. In particular, we obtain all Bol loops of order 16 with a non-subloop commutant.
The Distance to NGC 6397 by M-Subdwarf Main-Sequence Fitting

Recent years have seen a substantial improvement both in photometry of low-luminosity stars in globular clusters and in modeling the stellar atmospheres of late-type dwarfs. We build on these observational and theoretical advances in undertaking the first determination of the distance to a globular cluster by main-sequence fitting using stars on the lower main sequence. The calibrating stars are extreme M subdwarfs, as classified by Gizis, with parallaxes measured to a precision of better than 10%. Matching against King et al.'s deep [V, (V-I)] photometry of NGC 6397, and adopting E_(B-V) = 0.18 mag, we derive a true distance modulus of 12.13 ± 0.15 mag for the cluster. This compares with (m - M)_0 = 12.24 ± 0.1 derived through conventional main-sequence fitting in the [V, (B-V)] plane. Allowing for intrinsic differences due to chemical composition, we derive a relative distance modulus of δ(m - M)_0 = 2.58 mag between NGC 6397 and the fiducial metal-poor cluster M92. We extend this calibration to other metal-poor clusters and examine the resulting RR Lyrae (MV, [Fe/H]) relation.
Quantifying the ease of scientific discovery

It has long been known that scientific output proceeds on an exponential increase, or more properly, a logistic growth curve. The interplay between effort and discovery is clear, and the nature of the functional form has been thought to be due to many changes in the scientific process over time. Here I show a quantitative method for examining the ease of scientific progress, another necessary component in understanding scientific discovery. Using examples from three different scientific disciplines--mammalian species, chemical elements, and minor planets--I find the ease of discovery to conform to an exponential decay. In addition, I show how the pace of scientific discovery can be best understood as the outcome of both scientific output and ease of discovery. A quantitative study of the ease of scientific discovery in the aggregate, such as done here, has the potential to provide a great deal of insight into both the nature of future discoveries and the technical processes behind discoveries in science.
Characterization of ribonuclease P from Toxoplasma gondii

Summary Toxoplasma gondii ribonuclease P (RNase P) activity was identified and characterized. The enzyme cleaved the precursor of Escherichia coli tyrosine transfer RNA at a position identical to the site recognized by E. coli RNase P. The enzyme has a broad pH optimum from 7 to 9, is more active at 42°C than at 32°C and 37°C, and is relatively stable at 37°C and 42°C, but not at 56°C. Its activity is stimulated significantly as the concentration of Mg +2 is increased to 100 mM, but some activity remains in the presence of less than 1 μM free Mg +2 ; Ca +2 stimulates activity modestly up to 25 mM. Toxoplasma gondii RNase P differs from host (murine peritoneal exudate cells) RNase P, as indicated by its elution from cationic ion exchange columns at a relatively high salt concentration. It is effectively inhibited by mature tRNA and inactivated by pretreatment with micrococcal nuclease, thus indicating the presence of an essential RNA component. Correspondingly, a number of RNA molecules, ranging in size from about 170 to 490 nucleotides, are found in T. gondii RNase P containing fractions. This study provides the basis for further characterization of the structure and function of T. gondii RNase P and it extends the range of organisms in which RNase P has been characterized.
The neurophysiology and assessment of sports-related head injuries

This article provides a review of contemporary standards for the management of athletes who have sustained a sports-related head injury. Recent research regarding concussion management is reviewed with specific reference to clinical care. The use of neuropsychologic testing in sports also is reviewed, and a systematic protocol for the management of sports-related concussion is presented.
The complexity of the Pigeonhole Principle

The Pigeonhole Principle forn is the statement that there is no one-to-one function between a set of sizen and a set of sizen−1. This statement can be formulated as an unlimited fan-in constant depth polynomial size Boolean formulaPHP n inn(n−1) variables. We may think that the truth-value of the variablex i,j will be true iff the function maps thei-th element of the first set to thej-th element of the second (see Cook and Rechkow [5]).PHP n can be proved in the propositional calculus. That is, a sequence of Boolean formulae can be given so that each one is either an axiom of the propositional calculus or a consequence of some of the previous ones according to an inference rule of the propositional calculus, and the last one isPHP n . Our main result is that the Pigeonhole Principle cannot be proved this way, if the size of the proof (the total number or symbols of the formulae in the sequence) is polynomial inn and each formula is constant depth (unlimited fan-in), polynomial size and contains only the variables ofPHP n .
The Resonance Scattering of Protons by Lithium

The scattering of protons by a thick target of lithium has been studied in the energy region 272-586 kev at an angle of 156\ifmmode^\circ\else\textdegree\fi{}, with a ball counter. The number of counts per microcoulomb at 458 kev is 2.08 times its value at 408 kev, and at 487 kev it has dropped to 1.48 times the value at 408 kev. The energy at which the maximum slope of the thick target curve occurs is within five kev of the energy for the lithium gamma-ray resonance maximum. The fact that the scattering from a beryllium crystal increased smoothly with proton energy throughout the region, showed that the resonance effect is not a peculiarity of the counter. This scattering anomaly indicates: (1) that the gamma-radiation obtained when ${\mathrm{Li}}^{7}$ is bombarded with 440-kev protons arises from a virtual level of ${\mathrm{Be}}^{8}$; (2) that the ${\mathrm{Be}}^{8}$ state is odd; and (3) that there are no odd excited states of the alpha-particle below approximately 13 Mev.
Prices and Protocols in Public Health Care

This article addresses the problem of how to determine the optimal allocation of public expenditure in the health sector. The first part poses the question: How should the set of services provided in the public health care system and the fees charged for them is chosen to maximize the health status of the population with a fixed budget? First, the findings show that policy reform should take into account the response of the private sector. Substituting for a reasonably well functioning private sector is not as valuable as providing services the private sector cannot. Second, the assumptions needed to justify the cost effectiveness of medical interventions as a criterion for setting priorities are so restrictive as to make this method usable in few, if any, circumstances. Third, prices for any one service should be set to balance the conflicting goals of encouraging its use and of conserving the budget for more effective services. The second part broadens the objective of policy to cover the standard welfare economics concerns of utility and market failure, the latter being extensive in the health sector. It reexamines welfare maximization rules to show that only the market failure components of shadow prices are needed to calculate the welfare gains from public investments.
Regioselective Formation of α-Vinylpyrroles from the Ruthenium-Catalyzed Coupling Reaction of Pyrroles and Terminal Alkynes Involving C–H Bond Activation

The cationic ruthenium catalyst Ru3(CO)12/NH4PF6 was found to be highly effective for the intermolecular coupling reaction of pyrroles and terminal alkynes to give gem-selective α-vinylpyrroles. Th...
Hot rotating nuclei

Abstract I review various phenomena which are currently studied in the hot compound nucleus. A temperature dependent mean-field theory and large amplitude thermal fluctuations are the main components of a statistical approach. I discuss in detail a collective excitation of the hot nucleus, the giant dipole resonance (GDR), and its decay mechanism as a function of temperature and angular momentum. In particular the role of the GDR as a probe of the nuclear shape transitions is examined. Other topics covered are time-dependent fluctuations, useful in the study of dissipation and non-adiabatic effects at finite temperature, and methods to calculate the nuclear partition function and level density beyond the mean-field approximation.
Foreign-owned insurer performance in the US property-liability markets

Foreign-owned property-liability insurers have increased their market share in the US in the recent decades. They may have achieved this by being more efficient, by undercutting prices to attract away business from their domestic rivals, or both. We investigate return, risk, efficiency and determinants of efficiency performance of these insurers relative to their domestic competitors. We find that these firms are less profitable and less efficient in terms of cost scale and revenue X-efficiencies but more efficient in terms of cost X- and revenue scale efficiencies. Overall, the evidence shows that both of the aforementioned factors have contributed to their growth.
Sensitivity of climate change projections to uncertainties in the estimates of observed changes in deep-ocean heat content

The MIT 2D climate model is used to make probabilistic projections for changes in global mean surface temperature and for thermosteric sea level rise under a variety of forcing scenarios. The uncertainties in climate sensitivity and rate of heat uptake by the deep ocean are quantified by using the probability distributions derived from observed twentieth century temperature changes. The impact on climate change projections of using the smallest and largest estimates of twentieth century deep ocean warming is explored. The impact is large in the case of global mean thermosteric sea level rise. In the MIT reference (“business as usual”) scenario the median rise by 2100 is 27 and 43 cm in the respective cases. The impact on increases in global mean surface air temperature is more modest, 4.9 and 3.9 C in the two respective cases, because of the correlation between climate sensitivity and ocean heat uptake required by twentieth century surface and upper air temperature changes. The results are also compared with the projections made by the IPCC AR4’s multi-model ensemble for several of the SRES scenarios. The multi-model projections are more consistent with the MIT projections based on the largest estimate of ocean warming. However, the range for the rate of heat uptake by the ocean suggested by the lowest estimate of ocean warming is more consistent with the range suggested by the twentieth century changes in surface and upper air temperatures, combined with the expert prior for climate sensitivity.
Calibration and filtering strategies for frequency domain electromagnetic data

Abstract Repeat frequency-domain electromagnetic (FDEM) surveys have been acquired over agricultural fields in the Powder River Basin (PRB), Wyoming, where subsurface drip irrigation is being utilized for the beneficial dispersal of coalbed methane produced water. The purpose of the FDEM surveys is to monitor changes in subsurface electrical properties due to the injection of the produced water. In order to quantitatively interpret the data, however, both systematic and random errors must be accounted for. A calibration procedure, adapted from airborne geophysical data processing, corrects for systematic errors by making the FDEM data consistent with the results of a direct current resistivity survey that is coincident with a portion of the FDEM data. Calibration is shown to improve the inter-frequency relationships within the data, resulting in reduced misfit when the data are inverted and therefore added confidence in the inversion results. A filtering approach that is based on principal component analysis is used to attenuate random errors in the data. This type of filter is advantageous because it has a physical-basis in the fact that FDEM data are highly correlated across frequencies, and does not require an arbitrarily-defined spatial filter window length. The calibration and filtering methods are successfully applied to approximately 15 line-km of data in the PRB. It is apparent, however, that calibration parameters may drift in time and should be re-assessed at regular intervals throughout a survey.
Invariants for homology classes with application to optimal search and planning problem in robotics

We consider planning problems on Euclidean spaces of the form ?, where $\widetilde{\mathcal{O}}$ is viewed as a collection of obstacles. Such spaces are of frequent occurrence as configuration spaces of robots, where $\widetilde{\mathcal{O}}$ represent either physical obstacles that the robots need to avoid (e.g., walls, other robots, etc.) or illegal states (e.g., all legs off-the-ground). As state-planning is translated to path-planning on a configuration space, we collate equivalent plannings via topologically-equivalent paths. This prompts finding or exploring the different homology classes in such environments and finding representative optimal trajectories in each such class. In this paper we start by considering the general problem of finding a complete set of easily computable homology class invariants for (N???1)-cycles in (?. We achieve this by finding explicit generators of the (N???1) st de Rham cohomology group of this punctured Euclidean space, and using their integrals to define cocycles. The action of those dual cocycles on (N???1)-cycles gives the desired complete set of invariants. We illustrate the computation through examples. We then show, for the case when N?=?2, due to the integral approach in our formulation, this complete set of invariants is well-suited for efficient search-based planning of optimal robot trajectories with topological constraints. In particular, we show how to construct an `augmented graph', $\widehat{\mathcal{G}}$ , from an arbitrary graph $\mathcal{G}$ in the configuration space. A graph construction and search algorithm can hence be used to find optimal trajectories in different topological classes. Finally, we extend this approach to computation of invariants in spaces derived from (?by collapsing a subspace, thereby permitting application to a wider class of non-Euclidean ambient spaces.
Supernova 1993J: a veiled pulsar in a binary system?

The recent report of a binary companion to the progenitor of Supernova 1993J may provide important clues for identifying the nature of the nascent compact object. Given the estimates of the progenitor mass, the potential power source is probably a pulsar rather than an accreting black hole. If there is a pulsar, one would expect the rotational luminosity to be stored and reprocessed by the supernova remnant, but no pulsar nebula has yet been seen. The lack of detection of an X-ray synchrotron nebula should be taken as strong evidence against the presence of a bright pulsar. This is because absorption by the surrounding supernova gas should be negligible for the light of the companion star to have been detected. A model is developed here for the luminosity of the pulsar nebula in SN 1993J, which is then used to predict the spin-down power of the putative pulsar. If one exists, it can be providing no more than ∼6 x 10 39 erg s -1 . With an initial rotation period of 10-30 ms, as extrapolated from young Galactic pulsars, the nascent neutron star can have either a weak magnetic field, B ≤ 10 11 G, or one so strong, B ≥ 10 15 G, that its spin was rapidly slowed down. The companion star, if bound to the neutron star, should provide ample targets for the pulsar wind to interact and produce high-energy gamma-rays. The expected non-pulsed, GeV signal is calculated; it could be detected by current and future experiments provided that the pulsar wind velocity is similar to that of the Crab nebula.
Action functionals for strings in four dimensions

All possible action functionals on the space of surfaces in ℝ4 that depend only on first and second derivatives of the functions, entering the equation of the surface, and satisfy the condition of invariance with respect to rigid motions, are described.
Stock market trading via stochastic network optimization

We consider the problem of dynamic buying and selling of shares from a collection of N stocks with random price fluctuations. To limit investment risk, we place an upper bound on the total number of shares kept at any time. Assuming that prices evolve according to an ergodic process with a mild decaying memory property, and assuming constraints on the total number of shares that can be bought and sold at any time, we develop a trading policy that comes arbitrarily close to achieving the profit of an ideal policy that has perfect knowledge of future events. Proximity to the optimal profit comes with a corresponding tradeoff in the maximum required stock level and in the timescales associated with convergence. We then consider arbitrary (possibly non-ergodic) price processes, and show that the same algorithm comes close to the profit of a frame based policy that can look a fixed number of slots into the future. Our approach uses a Lyapunov optimization technique previously developed for optimizing stochastic queueing networks.
Lower Bounds on the Randomized Communication Complexity of Read-Once Functions

We prove lower bounds on the randomized two-party communication complexity of functions that arise from read-once boolean formulae. A read-once boolean formula is a formula in propositional logic with the property that every variable appears exactly once. Such a formula can be represented by a tree, where the leaves correspond to variables, and the internal nodes are labeled by binary connectives. Under certain assumptions, this representation is unique. Thus, one can define the depth of a formula as the depth of the tree that represents it. The complexity of the evaluation of general read-once formulae, has attracted interest mainly in the decision tree model. In the communication complexity model, many interesting results deal with specific read-once formulae, such as DISJOINTNESS and TRIBES. In this paper we use information theory methods to prove lower bounds that hold for any read-once formula. Our lower bounds are of the form n(f)/c^{d(f)}, where n(f) is the number of variables and d(f) the depth of the formula, and they are optimal up to the constant c in the denominator.
Nanoparticulate cellular patches for cell-mediated tumoritropic delivery.

The targeted delivery of therapeutics to tumors remains an important challenge in cancer nanomedicine. Attaching nanoparticles to cells that have tumoritropic migratory properties is a promising modality to address this challenge. Here we describe a technique to create nanoparticulate cellular patches that remain attached to the membrane of cells for up to 2 days. Neutravidin-coated nanoparticles were anchored on cells by binding to biotinylated plasma membrane. Human bone marrow derived mesenchymal stem cells with nanoparticulate patches retained their inherent tumoritropic properties as shown using a tumor model in a 3D extracellular matrix (P-value < 0.001). Additionally, Human umbilical vein endothelial cells with nanoparticulate patches were able to retain their functional properties and form multicellular structures as rapidly as unmodified endothelial cells. These results provide a novel strategy to actively deliver nanostructures and therapeutics to tumors utilizing stem cells as carriers, and also suggest that nanoparticulate cellular patches may have applications in tissue regeneration.
Controlling stockholders and the disciplinary role of corporate payout policy: a study of the Times Mirror Company

Abstract The Times Mirror Company, a NYSE-listed Fortune 500 firm controlled for 100 years by the Chandler family, hired an industry outsider as CEO in 1995 following an extended period of poor operating and stock price performance under non-family management. This change was apparently an unintended consequence of actions taken by old management to fund its capital expansion plans while satisfying the family's desire for dividends. Specifically, in 1994 old management agreed to (1) sell TM's cable business and reinvest most of the $1.3 billion proceeds in new technology, and (2) maintain the Chandlers’ dividends while radically cutting those to minority stockholders. While Wall Street reacted favorably to the cable sale, it punished TM's stock when it later learned about management's reinvestment plans. Shortly thereafter TM's board brought in a noted financial disciplinarian, who as CEO substantially increased stockholder value by terminating low return investments and distributing free cash flow. While pressure to pay dividends and monitoring by large block stockholders ultimately improved TM's performance, the path to this outcome was slow and circuitous, so that these disciplinary forces were weaker than theory typically implies.
In Place Differential File Compression

We present algorithms for in-place differential file compression, where a target file T of size n is compressed with respect to a source file S of size m using no additional space in addition to the that used to replace S by T; that is, it is possible to encode using m + n + O(1) space and decode using MAX(m,n) + O(1) space (so that when decoding the source file is overwritten by the decompressed target file). From a theoretical point of view, an optimal solution (best possible compression) to this problem is known to be NP-hard, and in previous work we have presented a factor of 4 approximation (not in-place) algorithm based on a sliding window approach. Here we consider practical in-place algorithms based on sliding window compression where our focus is on decoding; that is, although in-place encoding is possible, we will allow O(m + n) space for the encoder so as to improve its speed and present very fast decoding with only MAX(m, n) + O(1) space. Although NP-hardness implies that these algorithms cannot always be optimal, the asymptotic optimality of sliding window methods along with their ability for constant-factor approximation is evidence that they should work well for this problem in practice. We introduce the IPSW algorithm (in-place sliding window) and present experiments that indicate that it compares favorably with traditional practical approaches, even those that do not decode in-place, while at the same time having low encoding complexity and extremely low decoding complexity. IPSW is most effective when S and T are reasonably well aligned (most large common substrings occur in approximately the same order). We also present a preprocessing step for string alignment that can be employed when the encoder determines significant gains will be achieved.
Sustainability and Resilience: Toward a Systems Approach

A comprehensive systems approach is essential for effective decision making with regard to global sustainability, since industrial, social, and ecological systems are closely linked. Despite effort...