cssi/SciSciGPT-SciSciNet huggingface dataset:
The Unusual and the Expected in the Si/C Phase Diagram

In the Si/C phase diagram, the only stable phases at P = 1 atm are the numerous polytypes of the simplest 1:1 stoichiometry, SiC. However, many metastable yet likely to be kinetically persistent phases can be found for almost any composition. Given the instability of simple graphite-type structures with considerable Si content, we thought these metastables would be only of the diamondoid class. Indeed they are for Si3C, a stoichiometry we studied on the silicon-rich side of the phase diagram. Yet on the carbon-rich side, which we chose to explore computationally with SiC3, there was a surprise in store, a series of unusual metastable structures. The most striking of these had the appearance of a collapsed graphite structure, with benzenoid C6 units and SiSi bridges between layers. This SiC3 structure is related to known meta-(1,3,5)cyclophanes. Three other metastable structures featured layers with all carbon polyene and polyphenylene arrays. Some of these can be metallic, as we have found.
A WIMP detector with two-phase liquid xenon

Abstract We describe the liquid-xenon dark-matter detector program of the UCLA-Torino team. A two-phase detector, ZEPLIN II, for the Boulby Mine is a good match for the current search for WIMP dark matter.
Interference effects at the single photon level

Abstract Interference effects have been demonstrated in the superposition of two light beams from two independent lasers, under conditions where the intensity was so low that one photon was absorbed, with high probability, before the next one was emitted by either one of the sources.
On-Site Treatment of Exertional Heat Stroke

Background:Exertional heat stroke is a devastating condition that can cause significant morbidity and mortality. Rapid cooling is the most effective means of treating heat stroke, but little is published on the safety and logistics of cooling patients on site at a major sporting event.Purpose:To describe an on-site exertional heat stroke treatment protocol and to compare the outcomes of patients treated on site to those transferred to hospitals.Study Design:Descriptive epidemiological study.Methods:Using race-day medical records and ambulance run sheets, patients who developed exertional heat stroke at the Indianapolis half-marathon from 2005 to 2012 were identified. Exertional heat stroke was defined as runners with a core temperature measured with a rectal thermometer greater than 102°F and altered mental status. Clinical information and patient outcomes were abstracted from the race medical tent and hospital charts by 3 separate trained reviewers using structured methods and a data collection form. Two...
The Effect of Accounting Uncertainty and Auditor Reputation on Auditor Objectivity

This paper reports results of experimental markets that examine whether accounting uncertainty impacts auditor objectivity in a setting where the auditor also has an incentive to build a reputation for objectivity. While prior research has examined the impact of uncertainty on auditor objectivity, our research is the first to explicitly incorporate auditor reputation into the research design. The results provide strong evidence that accounting uncertainty impacts auditor objectivity despite the damage to auditor reputation. Our markets suggest that in the absence of accounting uncertainty auditors remain objective due to concerns about their reputation with managers and investors. However, in the presence of accounting uncertainty auditors impair their objectivity by misreporting in favor of managers. Our results suggest that regulators should focus on enhancing auditor incentives to maintain objectivity when faced with accounting uncertainty, but do not need to be concerned about auditor objectivity viol...
Dynamic omnidirectional vision for mobile robots

Mobile robotic devices hold great promise for a variety of applications in industry. A key step in the design of a mobile robot is to determine the navigation method for mobility control. The purpose of this paper is to describe a new algorithm for omnidirectional vision navigation. A prototype omnidirectional vision system and the implementation of the navigation techniques using this modern sensor and an advanced automatic image processor is described. The significance of this work is in the development of a new and novel approach—dynamic omnidirectional vision for mobile robots and autonomous guided vehicles.
Hooge fluctuation parameter of semiconductor microstructures

The Hooge 1/f fluctuation parameter alpha /sub H/ of a mesoscopic n-GaAs filament is studied experimentally and compared with that derived from the quantum model. The minimum value of the Hooge parameter alpha /sub H/ was 2*10/sup -6/ and 1*10/sup -8/ at room temperature and 60 K, respectively. The temperature dependence of alpha /sub H/ below 100 K and the electric field dependence at 77 K are favorably compared with those obtained for the impurity scattering fluctuation of the quantum 1/f noise theory. >
Revisiting the Tidal Activation of Seismicity With A Damage Mechanics and Friction Point of View

— The Load Unload Response Ratio theory (LURR) puts forward the idea that the ratio of seismicity during times of increased tidal loading to times of decreased tidal loading takes on anomalously large values as the preparatory region of the earthquake approaches a critical state. We repeated the calculations of LURR for several earthquakes in California, for which results had been published, using estimates of the parameters which could be determined from the published work. We were unable to confirm any LURR ratio predictive significance. We test an alternative method of evaluating the influence of tidal stresses on earthquakes based on damage mechanics. As in rock mechanics experiments, it may be that anomalous activation of seismicity prior to large earthquakes occurs only during those time intervals when the applied stress exceeds values previously attained. We applied this approach to analyze the same data set used to test the LURR hypothesis, and it also failed to reveal any significant precursory indications. It may be that time-dependent failure processes such as self-driven nucleation occur on a time scale longer than the diurnal tide, thus destroying the expected synchronization.
Absorptive capacity and R&D tax policy: Are in-house and external contract R&D substitutes or complements?

Firms fund research and development (R&D) to generate commercializable innovations and to increase their ability to understand and absorb knowledge from elsewhere. This dual role and opposed incentive structure of internal R&D create a significant question for both theory and R&D policy: Is internal R&D a complement or substitute for external R&D? We develop a model and novel technique for empirically estimating R&D substitution elasticities. We focus on bio-pharmaceutical and software industries in California and Massachusetts, where tax credit rates changed differently over time for the two types of R&D, creating a natural experiment. The effective tax prices for the two R&D types differ from type to type, firm to firm, state to state, and year to year. This allows us to examine changes in the composition of firms’ R&D budgets between in-house R&D and external basic research when the relative tax prices of each category of research change. We find evidence of a substitute relationship both for a sample comprising exclusively small firms as well as for a more general distribution of firm sizes.
Hypervalent iodine oxidation: Synthesis of 5-substituted-2(5H)-furanones using iodosobenzene

Abstract Hypervalent iodine oxidation of 2-(trimethylsilyloxy)furan with iodosobenzene:boron trifluoride etherate in the presence of various nucleophiles yields 5-substituted-2(5H)-furanones.
Third-Degree Price Discrimination: Apology Not Necessary

Applied work in price discrimination often treats demand curves among multiple market segments as algebraically additive. Yet the welfare effects of multi-market (third degree) price discrimination depend on how the demand segments are added. Treating demands as geometrically additive yields the well known result that discrimination absent an increase in production diminishes Marshallian surplus. But if demands are treated as algebraically additive then discrimination increases welfare over uniform pricing. Quantity is identical in the three cases, so the effect is not due to market opening. Nor is the effect due to scale economies since marginal cost is assumed constant. Profit is always greater under discrimination, so the effect is due to distributional changes in consumer surplus. The model is restricted to linear demands and constant marginal cost but can be generalized for future work and policy analysis.
Alkoxylation, Thiolation And Hydrazination of α,β-Unsaturated Nitro Olefins Under Aprotic Conditions

Abstract Treatment of α,β-unsaturated nitro olefins with RO, RS, or RR'NNH under aprotic conditions provides Michael-type adducts in good to excellent yields.
A Decomposition of Markov Processes via Group Actions

We study a decomposition of a general Markov process in a manifold invariant under a Lie group action into a radial part (transversal to orbits) and an angular part (along an orbit). We show that given a radial path, the conditioned angular part is a nonhomogeneous Levy process in a homogeneous space, we obtain a representation of such processes and, as a consequence, we extend the well-known skew-product of Euclidean Brownian motion to a general setting.
Cold dense magnetopause boundary layer under northward IMF: Results from THEMIS and MHD simulations

[1] A layer of nearly stagnant cold dense plasma is observed by THEMIS spacecraft in a closed field region immediately inside the dayside magnetopause near the low-latitude boundary layer on 3 June 2007. Using the OpenGGCM global MHD magnetosphere numerical model, we successfully reproduce this observed cold dense plasma layer in the simulation. The simulation results show that reconnection first occurs poleward of the cusp in the northern hemisphere, creating new open field lines extending southward and forming an open field layer; then subsequently occurs in the other hemisphere, creating new closed field lines that capture the magnetosheath plasma and form the dayside cold dense plasma layer. In this event, the open layer and the skin of the cold dense plasma layer have a southward tangential flow while the inner part of the cold dense plasma layer has a more stagnant and more turbulent flow.
Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH, −NHTs, −OAc, −OTs, −OTf, −COMe, −NHBoc, −NHCbz, −CN, −SO2Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki–Miyaura, Stille, and Hiyama–Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R–X) and no reaction at the nucleophilic carbon (R–[M]) for organoboron (−Bpin), organotin (−SnMe3), and organosilicon (−SiMe2OH) containing organic halides (X–R–[M...
Arenimycin, an antibiotic effective against rifampin- and methicillin-resistant Staphylococcus aureus from the marine actinomycete Salinispora arenicola.

Arenimycin, an antibiotic effective against rifampin- and methicillin-resistant Staphylococcus aureus from the marine actinomycete Salinispora arenicola
Insertion reactions of chromium-carbene complexes with organic nitriles and a diastereoselective alkylation of a resulting imino-carbene complex

On etudie les reactions d'insertion de nitriles dans les complexes (CO) 5 Cr=C(OMe)(R 1 ) conduisant a (CO) 5 Cr=C(R 2 )(NR 1 CH 3 O). Mecanisme
Interstellar matter in early-type galaxies - Optical observations

Results of optical observations of 26 bright elliptical galaxies selected on the basis of IRAS data are discussed. Optical broadband imaging (using B and R filters) and narrow-band imaging (using H-alpha interference filters) have been performed to study dust patches and ionized gas. Long-split spectroscopy has also been made to determine gas kinematics and relative line ratios. The spectroscopic data confirm the presence and distribution of interstellar matter (dust lanes and ionized gas) seen in the direct imaging. Decoupled kinematics of interstellar gas and stars favors an external origin of the interstellar matter. However, for one isolated galaxy, an internal origin is not excluded. The rotation curves determined by optical emission lines are symmetric around the center in most galaxies observed. Galaxy masses and mass-to-light ratios are estimated using the rotation curves of the ionized gas.
Catalog of Fundamental-Mode RR Lyrae Stars in the Galactic Bulge from the Optical Gravitational Lensing Experiment

We present a catalog of 1888 fundamental-mode RR Lyrae stars detected in the Galactic bulge fields of the second phase of the Optical Gravitational Lensing Experiment (OGLE). The catalog includes basic parameters of the light curves, identifications of Blazhko frequencies, V - I colors at minimum light (for most stars), and other information for each star. We detect a high rate of incidence of the Blazhko phenomenon (at least 27.6%), including unprecedentedly many frequency triplets, which we attribute to our sensitive search method. We find that the minimum light V - I color (useful as a reddening indicator) grows slowly redder with increasing period and exhibits a star-to-star scatter of approximately 0.07 mag. We use this color to evaluate the zero-point accuracy of the reddening map of the Galactic bulge derived from OGLE data and find that in addition to low-level random errors or resolution effects (responsible for much of the scatter), the map may systematically overrepresent E(V - I) by approximately 0.05 mag in most fields. We present reasonably robust evidence that the RR Lyrae-to-red clump color separation is larger by 0.05-0.08 mag in the bulge than locally, which argues for caution in the use of these stars for reddening determinations. We consider the RR Lyrae constraint on the Galactocentric distance, but uncertainty about the absolute magnitude calibration leaves significant flexibility in the result. In contrast to previous results, we robustly detect the signature of the Galactic bar in the RR Lyrae population within the inner ±3° of longitude, and we highlight the apparent differences between the structures traced by the red clump giants and the more metal-poor RR Lyrae stars.
Susan smiled: on explanation in family therapy.

The contemporary psychotherapist is exposed to a variety of conceptual models and paradigms. These are usually presented as opposing truths in different doctrinal schools, but actually they are all valid from one point of view or another. And, accordingly, they are all tactically useful at some point or another. I thought it was important to say this, but I did not want to write a dry, academic paper on the subject. So I will tell a clinical story that weaves the threads into a fabric.
Synthesis of orotidine by intramolecular nucleosidation

An intramolecular nucleosidation approach provides easy access to orotidine in high yields. Notably, orotate itself is used as a leaving group at the anomeric position. This method has the potential for facile access to derivatives of orotidine of therapeutic interest, with implications for prebiotic formation of nucleosides.
SlackSim: a platform for parallel simulations of CMPs on CMPs

The fast simulation of chip multiprocessors (CMPs) presents a critical challenge to the architecture research community as both industry and academia shift their research focus to multicore design. Parallel simulation is a technique to accelerate microarchitecture simulation of CMPs by exploiting the inherent parallelism of CMPs. In this paper, we explore the simulation paradigm of simulating each core of a target CMP in one thread and then spreading the threads across the hardware thread contexts of a host CMP. We implement several parallel simulation schemes using POSIX Threads (Pthreads). We start with cycle-by-cycle simulation and then relax the synchronization condition in various schemes, which we call slack simulations.In slack simulations, the Pthreads simulating different simulated cores do not synchronize after each simulated cycle, but rather they are given some slack. The slack is the difference in cycle between the simulated times of any two target cores. Small slacks, such as a few cycles, greatly improve the efficiency of parallel CMP simulations, with no or negligible simulation error. We have developed a simulation framework called SlackSim to experiment with various slack simulation schemes. Unlike previous attempts to parallelize multiprocessor simulations on distributed memory machines, SlackSim takes advantage of the efficient sharing of data in the host CMP architecture.We demonstrate the efficiency and accuracy of some well known slack simulation schemes and of some new ones on SlackSim running on a state-of-the-art CMP platform.
Synthesis of trovafloxacin using various (1α,5α,6α)-3-azabicyclo[3.1.0]hexane derivatives

Trovafloxacin, a novel broad spectrum antibacterial, contains the unusual (1α,5α,6α)-3-azabicyclo[3.1.0]hexane ring system. The prototype of the industrial synthesis of this ring system and possible mechanistic pathways to exclusive formation of the exo or 6α-nitro derivative 4 are described, which leads to the key 6α-nitro-3-azabicyclo[3.1.0]hexane intermediate 10. The synthesis of 6α-amino-3-azabicyclo[3.1.0]hexane 16 and useful protected exo 6-amino derivatives 15 and 17 follows from 10. These can be coupled with the 7-chloronaphthyridone 18 to yield protected trovafloxacin compounds 20–22 in good yield. The ethyl ester of trovafloxacin 21 can also be accessed from the product of coupling 19, derived from 18 and the exo 6-nitro-3-azabicyclo[3.1.0]hexane compound 12. Removal of protecting groups from 20–22 with methanesulfonic acid yields trovafloxacin mesylate from which trovafloxacin zwitterion 1 can be liberated with base treatment. Zwitterion 1 can also be prepared directly from 16 tosylate salt and naphthyridone-2-carboxylic acid 26.
On learning thresholds of parities and unions of rectangles in random walk models

In a recent breakthrough, [Bshouty et al., J Comput Syst Sci 71 (2005), 250265] obtained the first passive-learning algorithm for DNFs under the uniform distribution. They showed that DNFs are learnable in the Random Walk and Noise Sensitivity models. We extend their results in several directions. We first show that thresholds of parities, a natural class encompassing DNFs, cannot be learned efficiently in the Noise Sensitivity model using only statistical queries. In contrast, we show that a cyclic version of the Random Walk model allows to learn efficiently polynomially weighted thresholds of parities. We also extend the algorithm of Bshouty et al. to the case of Unions of Rectangles, a natural generalization of DNFs to {0,&,b - 1}n. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Dense error correction for low-rank matrices via Principal Component Pursuit

We consider the problem of recovering a low-rank matrix when some of its entries, whose locations are not known a priori, are corrupted by errors of arbitrarily large magnitude. It has recently been shown that this problem can be solved efficiently and effectively by a convex program named Principal Component Pursuit (PCP), provided that the fraction of corrupted entries and the rank of the matrix are both sufficiently small. In this paper, we extend that result to show that the same convex program, with a slightly improved weighting parameter, exactly recovers the low-rank matrix even if “almost all” of its entries are arbitrarily corrupted, provided the signs of the errors are random. We corroborate our result with simulations on randomly generated matrices and errors.
Asymmetric Contests with Conditional Investments

Rent-seeking scenarios, competitions for promotions, and research and development (R&D) races are examples of competitions in which participants expend resources regardless of whether they win or lose. Although similar in their “all-pay” feature, such competitions often differ in important dimensions. These include the type of technologies employed in competition, the type of asymmetries among competitors, the degree to which expenditures are sunk, and the number of prizes. Consider lobbying settings in which firms expend resources in order to influence a policymaker. If expenditures take the form of monetary outlays and all firms have the same cost of capital, then it is reasonable to think of firms’ marginal cost of influence as linear. But if a firm has a reputational advantage and high costs of capital, its “lobbying technology” may be more reasonably thought of as having convex costs (relatively low marginal costs up to a moderate level of influence, due to the reputational advantage, and relatively high marginal costs at higher levels of influence, due to the high costs of capital). Similarly, the lobbying technology of a firm that is relatively unknown and has low costs of capital may be characterized by concave costs. Lobbying restrictions, geographic location, or preferential treatment by the policymaker further impact firms’ lobbying technologies, inducing additional nonlinearities and asymmetries among firms. In some lobbying settings, firms also commit to expenditures conditional on a favorable outcome. For example, a firm may commit to building factories and creating new jobs if it is granted one of a limited number of manufacturing licenses. Thus, the specification of firms’ lobbying technologies, the type of asymmetries among firms, the combination of unconditional and conditional investments, and the number of eventual “winners” may change according to the lobbying setting studied. The same is true for other competitions with an all-pay feature. In a competition for promotions, workers often differ in their abilities, experience, and social skills. More than one prize
The Use of Gamma‐Ray Bursts as Direction and Time Markers in SETI Strategies

When transmitting a signal over a large distance, it is more efficient to send a brief beamed signal than a continuous omnidirectional transmission, but this requires that the receiver knows where and when to look for the transmission. For SETI, the use of various natural phenomena has previously been suggested to achieve the desired synchronization. Here it is proposed that gamma-ray bursts may well be the best "synchronizers" of all currently known phenomena because of their large intrinsic luminosities, high occurrence rate, isotropic sky distribution, large distance from the Galaxy, short duration, and easy detectability. For targeted searches, precise positions for gamma-ray bursts are required together with precise distance measurements to a target star. The required burst position determinations are now starting to be obtained, aided in large part by the discovery of optical afterglows. Good distance measurements are currently available from Hipparcos, and even better measurements should be provided by spacecraft now being developed. For nontargeted searches, positional accuracies simply better than a detector's field of view may suffice, but the time delay between the detection of a gamma-ray burst and the reception of the transmitted signal cannot be predicted in an obvious way.
Preparation and Diels-Alder/cross coupling reactions of new 2-boron-substituted 1,3-dienes.

Several new 2-boron substituted dienes have been prepared and characterized. Their reactivity in Diels–Alder reactions has been examined and the boron substituted cycloadducts of those cycloaddition reactions have been used in cross coupling reactions. One-pot tandem Diels–Alder/cross coupling reactions of 2-boron substituted dienes are then also reported along with some experimental evidence that these one-pot reactions are proceeding through a Pd(II)-catalyzed Diels–Alder/cross coupling reaction pathway.
Determination of actinide isotope ratios using glow discharge optogalvanic spectroscopy

Abstract Diode laser-excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235+U-238 isotope ratios. This `optical mass spectrometric' measurement has been demonstrated for a number of samples including uranium oxide, fluoride, and metal. Various diode laser-accessible atomic transitions in the 775–835 nm region have been evaluated; these transitions were chosen by considering OGS sensitivity and isotope shift. Using the 831.84 nm uranium line, for example, it was possible to measure the U-235/U-235+U-238 isotope ratio (0.0026) of depleted uranium samples. A prototypical field instrument to make these measurements has been assembled and demonstrated. A U-236 spectral line was identified in an enriched uranium sample, and an abundance was measured.
CAD-based computer vision: from CAD models to relational graphs

The topic of model-building for 3-D objects is examined. Most 3-D object recognition systems construct models either manually or by training. Neither approach has been very satisfactory, particularly in designing object recognition systems which can handle a large number of objects. Recent interest in integrating mechanical CAD systems and vision systems has led to a third type of model building for vision: adaptation of preexisting CAD models of objects for recognition. If a solid model of an object to be recognized is already available in a manufacturing database, then it should be possible to infer automatically a model appropriate for vision tasks from the manufacturing model. Such a system has been developed. It uses 3-D object descriptions created on a commercial CAD system and expressed in both the industry-standard IGES form and a polyhedral approximation and performs geometric inferencing to obtain a relational graph representation of the object which can be stored in a database of models for object recognition. Relational graph models contain both view-independent information extracted from the IGES description and view-dependent information (patch areas) extracted from synthetic views of the object. It is argued that such a system is needed to efficiently create a large database (more than 100 objects) of 3-D models to evaluate matching strategies. >
From noncommutative bosonization to S-duality

We extend standard path-integral techniques of bosonization and duality to the setting of noncommutative geometry. We start by constructing the bosonization prescription for a free Dirac fermion living in the noncommutative plane ?2. We show that in this abelian situation the fermion theory is dual to a noncommutative Wess-Zumino-Witten model. The non-abelian situation is also constructed along very similar lines. We apply the techniques derived to the massive Thirring model on noncommutative ?2 and show that it is dualized to a noncommutative WZW model plus a noncommutative cosine potential (like in the noncommutative Sine-Gordon model). The coupling constants in the fermionic and bosonic models are related via strong-weak coupling duality. This is thus an explicit construction of S-duality in a noncommutative field theory.
Asymptotic stability of the cross curvature flow at a hyperbolic metric

We show that for any hyperbolic metric on a closed 3-manifold, there exists a neighborhood such that every solution of a normalized cross curvature flow with initial data in this neighborhood exists for all time and converges to a constant-curvature metric. We demonstrate that the same technique proves an analogous result for Ricci flow. Additionally, we prove short-time existence and uniqueness of cross curvature flow under slightly weaker regularity hypotheses than were previously known.
Del Pezzo surfaces of degree 6

We give a correspondence which associates, to any Del Pezzo surface X of degree 6 over a field k of characteristic 0, a collection of data consisting of a Severi-Brauer variety/k and a set of points defined over some extension of k.
NEW ORGANIC MATERIALS SUITABLE FOR USE IN CHEMICAL SENSOR ARRAYS

Abstract : In this paper we discuss several different approaches for preparing chemically sensitive interfaces suitable for array-based chemical sensing applications. The characteristics of all these materials are that they are simple to prepare, synthetically versatile, easy to immobilize on transducer surfaces, exhibit chemical class selectivity to a significant extent, provide rapid (and in most cases fully reversible) responses to analytes, and are relatively durable and inexpensive. The first class of surface coatings are organomercaptan self-assembled monolayers (SAMs) terminated in chemically sensitive functional groups. The second class are bilayers prepared by modifying the aforementioned SAMs with either metal ions or calixNarenes. Dendritic polymers confined to surfaces comprise the final class of chemically sensitive interfacial materials. In addition to the synthesis of these materials, we provide ex-situ and in-situ characterization of their structure and chemical properties as well as their interactions with selected analytes using surface-infrared spectroscopy, surface acoustic wave (SAW) device-based gravimetry, and X-ray photoelectron spectroscopy.
TUNING MAGNETIC DISORDER IN DILUTED MAGNETIC SEMICONDUCTORS USING HIGH FIELDS TO 89 TESLA

We describe recent and ongoing studies at the National High Magnetic Field Laboratory at Los Alamos using the new "100 Tesla Multi-Shot Magnet", which is presently delivering fields up to ~89 T during its commissioning. We discuss the first experiments performed in this magnet system, wherein the linewidth of low-temperature photoluminescence spectra was used to directly reveal the degree of magnetic alloy disorder 'seen' by excitons in single Zn0.80Cd0.22Mn0.08Se quantum wells. The magnetic potential landscape in II-VI diluted magnetic semiconductors (DMS) is typically smoothed when the embedded Mn2+ spins align in an applied field. However, an important (but heretofore untested) prediction of current models of compositional disorder is that magnetic alloy fluctuations in many DMS compounds should increase again in very large magnetic fields approaching 100 T. We observed precisely this increase above ~70 T, in agreement with a simple model of magnetic alloy disorder.
Sharp edge, vertex, and mixed Cheeger type inequalities for finite Markov kernels

We show how the evolving set methodology of Morris and Peres can be used to show Cheeger inequalities for bounding the spectral gap of a finite Markov kernel. This leads to sharp versions of several previous Cheeger inequalities, including ones involving edge-expansion, vertex-expansion, and mixtures of both. A bound on the smallest eigenvalue also follows.
Crosslinking characteristics of an injectable poly(propylene fumarate)/β‐tricalcium phosphate paste and mechanical properties of the crosslinked composite for use as a biodegradable bone cement

We investigated the crosslinking characteristics of an injectable composite paste of poly(propylene fumarate) (PPF), N-vinyl pyrrolidinone (N-VP), benzoyl peroxide (BP), sodium chloride (NaCl), and beta-tricalcium phosphate (beta-TCP). We examined the effects of PPF molecular weight, N-VP/PPF ratio, BP/PPF ratio, and NaCl weight percent on the crosslinking temperature, heat release upon crosslinking, gel point, and the composite compressive strength and modulus. The maximum crosslinking temperature did not vary widely among formulations, with the absolute values falling between 38 degrees and 48 degrees C, which was much lower than that of 94 degrees C for poly(methyl methacrylate) bone cement controls tested under the same conditions. The total heat released upon crosslinking was decreased by an increase in PPF molecular weight and a decrease in N-VP/PPF ratio. The gel point was affected strongly by the PPF molecular weight, with a decrease in PPF molecular weight more rapidly leading to a gel point. An increase in initiator concentration had the same effect to a lesser degree. The time frame for curing was varied from 1-121 min, allowing the composite to be tailored to specific applications. The compressive strength and compressive modulus values increased with decreasing N-VP/PPF, increasing NaCl content, and increasing BP/PPF ratio. For all formulations, the compressive strength values fell between 1 and 12 MPa, and the compressive modulus values fell between 23 and 265 MPa. These data suggest that injectable PPF/beta-TCP pastes can be prepared with handling characteristics appropriate for clinical orthopedic applications and that the mechanical properties of the cured composites are suitable for trabecular bone replacement.
Dynamics of a Radially Rotating Beam With Impact, Part 2: Experimental and Simulation Results

The experimental results are presented and they are compared with simulations using the momentum balance model described in Part. 1. Excellent agreement was found between the experiments and simulation. Sensitivity studies were employed to show that the model is applicable for a fairly wide range of parameter values
A Photometric Study of Stars in the MBM 12 Association

We have monitored four fields containing nine previously identified members of the MBM 12 association to search for photometric variability and periodicity in these pre–main-sequence stars. Seven of the nine are found to be variable and definite periodicity (of 1.2, 2.6, and 6.2 days) is found for three of them, including the classical T Tauri star LkHα 264. Two other members are possibly periodic, but each requires confirmation. In addition, a "field" star that is associated with the X-ray source RX J0255.9+2005 was discovered to be a variable with a period of 4.2 days. Our results indicate that the photometric variability characteristics of the known MBM 12 association members are typical of what is found in roughly few-million-year-old stellar groups such as IC 348, supporting arguments for a similar age. In particular, there is a mix of periodic and nonperiodic variables with typical amplitudes (in Cousins I) of 0.1–0.5 mag, in addition to a small number of larger amplitude variables. The periods, as a group, are somewhat shorter than in IC 348, but when allowance is made for the known dependence of period on mass in pre–main-sequence stars the difference may not be significant. Our data confirm and illustrate the value of photometric monitoring as a tool for identifying likely association members and for studying rotation in extremely young stellar groups.
On vortices and phase coherence in high-Tc superconductors

An array of Cooper paired planes will not have long-range phase coherence at any finite temperature owing to an infrared divergence of phase fluctuations when the coherence length perpendicular to the plane is small enough to prevent leakage of the superconducting order parameter within the planes. The phase correlations decay in a sufficiently slow manner to provide enough local phase coherence to make possible the nucleation of vortices. The planes then acquire Kosterlitz–Thouless topological order with its intrinsic rigidity and concomitant superfluidity. We conclude that the high-temperature superconducting cuprates are topologically ordered superconductors rather than phase-ordered superconductors since the large insulating layer between the copper–oxygen planes prevents effective leakage of the superfluid order parameter. For low enough superfluid densities, as in the underdoped cuprates studied by Uemura, the transition temperature T c will be proportional to the superfluid density corresponding to...
Structural Health Monitoring Using Vibration Measurements and Engineering Insight

Several system identification algorithms have been proposed that make use of analytical models and measured modal data to determine the location and/or extent of structural damage. In particular, the authors have proposed a computationally attractive Minimum Rank Perturbation Theory (MRPT) which determines perturbation matrices to the mass, damping, and/or stiffness matrices. Inspection of these perturbation matrices provides insight to both the location and extent of structural damage. This paper documents our practical experience in applying MRPT theory to a variety of structures. The ability to incorporate engineering insight and judgment into the algorithm is shown to enhance the performance of the MRPT technique when faced with real-world issues.
The value of inside and outside money

Abstract We study dynamic economies in which agents may have incentives to hold both privately-issued (a.k.a. inside) and publicly-issued (a.k.a. outside) circulating liabilities as part of an equilibrium. Our analysis emphasizes spatial separation and limited communication as frictions that motivate monetary exchange. We isolate conditions under which a combination of inside and outside money does and does not allow the economy to achieve a first-best allocation of resources. We also study the extent to which the use of private circulating liabilities alone, or the use of public circulating liabilities alone, can address the frictions that lead to monetary exchange.
A survey of practical issues in underwater networks

Underwater sensor networks are attracting increasing interest from researchers in terrestrial radio-based sensor networks. There are important physical, technological, and economic differences between terrestrial and underwater sensor networks. In this survey, we highlight a number of important practical issues that have not been emphasized in recent surveys of underwater networks, with an intended audience of researchers who are moving from radio-based terrestrial networks into underwater networks.
Dual inhibition of mitogen-activated protein kinase kinase and mammalian target of rapamycin in differentiated and anaplastic thyroid cancer.

Context: Differentiated thyroid cancer and anaplastic thyroid cancer tumors frequently have activation of the ras/raf /MAPK kinase (MEK)/ERK and phosphatidylinositol 3-kinase (PI-3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathways. Objective: The objective of the study was to investigate the efficacy of MEK and mTOR inhibitors in preclinical thyroid cancer treatment models with defined mutation status. Experimental Design: The MEK inhibitor AZD6244 (ARRY-142886) and mTOR inhibitor rapamycin were tested separately and in combination in 10 differentiated thyroid cancer and anaplastic thyroid cancer cell lines and in a xenograft model for evidence of pathway inhibition, growth inhibition, apoptosis, and long-range adaptation and resistance. Results: Seven of 10 tested lines had evidence of significant basal activity of the PI-3K/AKT/mTOR pathway, with elevated phosphorylated AKT and phosphorylated p70 S6 kinase. Activation of ras/RAF/MEK/ERK was equally common in this panel. All 10 lines exhibite...
Predicting key example compounds in competitors' patent applications using structural information alone.

In drug discovery programs, predicting key example compounds in competitors' patent applications is important work for scientists working in the same or in related research areas. In general, medicinal chemists are responsible for this work, and they attempt to guess the identity of key compounds based on information provided in patent applications, such as biological data, scale of reaction, and/or optimization of the salt form for a particular compound. However, this is sometimes made difficult by the lack of such information. This paper describes a method for predicting key compounds in competitors' patent applications by using only structural information of example compounds. Based on the assumption that medicinal chemists usually carry out extensive structure−activity relationship (SAR) studies around key compounds, the method identifies compounds located at the centers of densely populated regions in the patent examples' chemical space, as represented by Extended Connectivity Fingerprints (ECFPs). F...
Reciprocal relationships between attitudes about gender and social contexts during young adulthood

Abstract Using data from a 31-year panel study, we investigate reciprocal relationships between individuals’ attitudes about gender and their experience with a range of social settings commonly associated with the transition to adulthood. These settings include school, the labor market, independent living arrangements, cohabitation, marriage, and parenthood. We consider the extent to which gender and age moderate the relationships between attitudes about gender and exposure to these social contexts. Ordinary least squares regression and hazard models demonstrate that support for egalitarian roles for women and men in families is positively linked to subsequent school enrollment, women’s full-time employment, and independent living, but negatively associated with the subsequent timing of entry into marriage and marital parenthood. Accumulated schooling, independent living, and full-time employment are associated with changes in individuals’ attitudes about gender. Despite careful attention to gender differences, we find surprisingly little evidence that the causes and consequences of attitudes about gender differ for women and men, with the primary exception being the positive association of employment and egalitarian gender attitudes for women but not for men.
On the separation of lossy source-network coding and channel coding in wireline networks

This paper proves the separation between source-network coding and channel coding in networks of noisy, discrete, memoryless channels. We show that the set of achievable distortion matrices in delivering a family of dependent sources across such a network equals the set of achievable distortion matrices for delivering the same sources across a distinct network which is built by replacing each channel by a noiseless, point-to-point bit-pipe of the corresponding capacity. Thus a code that applies source-network coding across links that are made almost lossless through the application of independent channel coding across each link asymptotically achieves the optimal performance across the network as a whole.
Formal [3 + 3] Cycloaddition Approach to Chromenes and Chromanes. Concise Total Syntheses of (±)-Rhododaurichromanic Acids A and B and Methyl (±)-Daurichromenic Ester

[reaction: see text] Total syntheses of (+/-)-rhododaurichromanic acids A and B and methyl (+/-)-daurichromenic ester are described here. Despite the complex appearances of these compounds, their syntheses are completed in six steps with a 15% overall yield as a mixture by featuring our formal oxa-[3 + 3] cycloaddition methodology.
Recombinant Neuregulin 1 Does Not Activate Cardiomyocyte DNA Synthesis in Normal or Infarcted Adult Mice

Objectives: Neuregulin 1 signaling plays an important role in cardiac trabecular development, and in sustaining functional integrity in adult hearts. Treatment with neuregulin 1 enhances adult cardiomyocyte differentiation, survival and/or function in vitro and in vivo. It has also been suggested that recombinant neuregulin 1b1 (NRG1b1) induces cardiomyocyte proliferation in normal and injured adult hearts. Here we further explore the impact of neuregulin 1 signaling on adult cardiomyocyte cell cycle activity. Methods and Results: Adult mice were subjected to 9 consecutive daily injections of recombinant NRG1b1 or vehicle, and cardiomyocyte DNA synthesis was quantitated via bromodeoxyuridine (BrdU) incorporation, which was delivered using mini-osmotic pumps over the entire duration of NRG1b1 treatment. NRG1b1 treatment inhibited baseline rates of cardiomyocyte DNA synthesis in normal mice (cardiomyocyte labelling index: 0.019i0.005% vs. 0.003i0.001%, saline vs. NRG1b1, P,0.05). Acute NRG1b1 treatment did result in activation of Erk1/2 and cardiac myosin regulatory light chain (down-stream mediators of neuregulin signalling), as well as activation of DNA synthesis in non-cardiomyocytes, validating the biological activity of the recombinant protein. In other studies, mice were subjected to permanent coronary artery occlusion, and cardiomyocyte DNA synthesis was monitored via tritiated thymidine incorporation which was delivered as a single injection 7 days post-infarction. Daily NRG1b1 treatment had no impact on cardiomyocyte DNA synthesis in the infarcted myocardium (cardiomyocyte labelling index: 0.039i0.011% vs. 0.027i0.021%, saline vs. NRG1b1, P.0.05). Summary: These data indicate that NRG1b1 treatment does not increase cardiomyocyte DNA synthesis (and consequently does not increase the rate of
An elevated-temperature titration calorimeter

A variable-temperature (313 K to 353 K) titration calorimeter of high sensitivity has been constructed. The purpose of the calorimeter is to study temperature effects on the enthalpies of complex formation and of other reactions of metal cations such as hydrolysis and precipitation. Operation of the calorimetric system, including final calculation of the enthalpy change during titration, is automatic via computer control. Calibration tests of the calorimeter using 2-amino-2-hydroxymethyl-1,3-propanediol gave −(46.0±0.3) kJ · mol−1 and −(46.2±0.2) kJ · mol−1 for the enthalpy of protonation, at the temperatures 318 K and at 343 K, respectively. For titrations of 2-bis(2-hydroxyethyl)amino-2-hydroxymethylpropan-1,3-diol, enthalpy of protonation values of −(28.4±0.3) kJ · mol−1 were obtained at 318 K and at 343 K, respectively.
Aluminum-based catalysts for the asymmetric Meerwein–Schmidt–Ponndorf–Verley–Oppenauer (MSPVO) reaction manifold

Abstract The development of aluminum-based catalysts for the asymmetric Meerwein–Schmidt–Ponndorf–Verley–Oppenauer (MSPVO) reduction/oxidation systems is reviewed with an emphasis on the mechanistic understanding of the origin for activity and selectivity in monometallic catalysts.
Persistence of donor-derived protein in host myeloid cells after induced rejection of engrafted allogeneic bone marrow cells

Objective In recipients of allogeneic hematopoietic stem cell transplantation to treat hematologic malignancies, we have unexpectedly observed anti-tumor effects in association with donor cell rejection in both mice and humans. Host-type CD8 T cells were shown to be required for these anti-tumor effects in the murine model. Because sustained host CD8 T-cell activation was observed in the murine bone marrow following the disappearance of donor chimerism in the peripheral blood, we hypothesized that donor antigen presentation in the bone marrow might be prolonged. Materials and Methods To assess this hypothesis, we established mixed chimerism with green fluorescent protein (GFP)−positive allogeneic bone marrow cells, induced rejection of the donor cells by giving recipient leukocyte infusions, and utilized in vivo microscopy to follow GFP-positive cells. Results After peripheral donor leukocytes disappeared, GFP persisted within host myeloid cells surrounding the blood vessels in the bone marrow, suggesting that the host myeloid cells captured donor-derived GFP protein. Conclusions Because the host-vs-graft reaction promotes induction of anti-tumor responses in this model, this retention of donor-derived protein may play a role in the efficacy of recipient leukocyte infusions as an anti-tumor therapy.