cssi/SciSciGPT-SciSciNet huggingface dataset:
Driven waves in a two-fluid plasma

We study the physics of wave propagation in a weakly ionized plasma, as it applies to the formation of multifluid, magnetohydrodynamics (MHD) shock waves. We model the plasma as separate charged and neutral fluids which are coupled by ion-neutral friction. At times much less than the ion-neutral drag time, the fluids are decoupled and so evolve independently. At later times, the evolution is determined by the large inertial mismatch between the charged and neutral particles. The neutral flow continues to evolve independently; the charged flow is driven by and slaved to the neutral flow by friction. We calculate this driven flow analytically by considering the special but realistic case where the charged fluid obeys linearized equations of motion. We carry out an extensive analysis of linear, driven, MHD waves. The physics of driven MHD waves is embodied in certain Green functions which describe wave propagation on short time-scales, ambipolar diffusion on long time-scales and transitional behaviour at intermediate times. By way of illustration, we give an approximate solution for the formation of a multifluid shock during the collision of two identical interstellar clouds. The collision produces forward and reverse J shocks in the neutral fluid and a transient in the charged fluid. The latter rapidly evolves into a pair of magnetic precursors on the J shocks, wherein the ions undergo force-free motion and the magnetic field grows monotonically with time. The flow appears to be self-similar at the time when linear analysis ceases to be valid.
Economic Analysis of Brain Drain

"In this paper, we consider the brain drain problem arising from the possibility of signaling and individual's two-stage decision procedures within an asymmetric information framework. Where the ranking of the universities provides a signal to domestic employers, our results indicate that, at rational expectations equilibrium, there is an association between students of a particular quality and corresponding qualities of universities they will choose to attend to attain Ph.D.'s. Moreover, we can predict whether these graduating Ph.D.'s choose to return home or remain abroad."
Chloroacrylonitrile, a detector substrate for carbene nucleophilicity; applications to phenylhalocarbenes

Abstract α-Chloroacrylonitrile is an excellent substrate for nucleophilic and ambiphilic carbenes; its use permits visualization of the latent ambiphilic properties of the phenylhalocarbenes.
Federal lending and the market for credit

Abstract Federal lending is an important, but unrecognized feature of modern credit markets. This paper analyzes the effects of credit interventions on credit allocation and economic efficiency. The underlying model posits asymmetric information between borrowers and lenders, and allows for market clearing, rationed, or redlined equilibria. Principal results include: unsubsidized credit interventions are neutral; the relative effectiveness of alternative lending instruments depends on whether rationing occurs; interactions among programs can have perverse effects; and, even without an informational advantage, the government may enact welfare-improving credit policies under certain conditions.
Surprise! Infants Consider Possible Bases of Generalization for a Single Input Example.

Infants have been shown to generalize from a small number of input examples. However, existing studies allow two possible means of generalization. One is via a process of noting similarities shared by several examples. Alternatively, generalization may reflect an implicit desire to explain the input. The latter view suggests that generalization might occur when even a single input example is surprising, given the learner's current model of the domain. To test the possibility that infants are able to generalize based on a single example, we familiarized 9-month-olds with a single three-syllable input example that contained either one surprising feature (syllable repetition, Experiment 1) or two features (repetition and a rare syllable, Experiment 2). In both experiments, infants generalized only to new strings that maintained all of the surprising features from familiarization. This research suggests that surprise can promote very rapid generalization.
Amplification of Asynchronous Inhibition-Mediated Synchronization by Feedback in Recurrent Networks

Synchronization of 30–80 Hz oscillatory activity of the principle neurons in the olfactory bulb (mitral cells) is believed to be important for odor discrimination. Previous theoretical studies of these fast rhythms in other brain areas have proposed that principle neuron synchrony can be mediated by short-latency, rapidly decaying inhibition. This phasic inhibition provides a narrow time window for the principle neurons to fire, thus promoting synchrony. However, in the olfactory bulb, the inhibitory granule cells produce long lasting, small amplitude, asynchronous and aperiodic inhibitory input and thus the narrow time window that is required to synchronize spiking does not exist. Instead, it has been suggested that correlated output of the granule cells could serve to synchronize uncoupled mitral cells through a mechanism called “stochastic synchronization”, wherein the synchronization arises through correlation of inputs to two neural oscillators. Almost all work on synchrony due to correlations presumes that the correlation is imposed and fixed. Building on theory and experiments that we and others have developed, we show that increased synchrony in the mitral cells could produce an increase in granule cell activity for those granule cells that share a synchronous group of mitral cells. Common granule cell input increases the input correlation to the mitral cells and hence their synchrony by providing a positive feedback loop in correlation. Thus we demonstrate the emergence and temporal evolution of input correlation in recurrent networks with feedback. We explore several theoretical models of this idea, ranging from spiking models to an analytically tractable model.
Highly Active, Air-Stable Palladium Catalysts for the C−C and C−S Bond-Forming Reactions of Vinyl and Aryl Chlorides: Use of Commercially Available [(t-Bu)2P(OH)]2PdCl2, [(t-Bu)2P(OH)PdCl2]2, and [[(t-Bu)2PO···H···OP(t-Bu)2]PdCl]2 as Catalysts

Air-stable palladium complexes [(t-Bu)(2)P(OH)](2)PdCl(2), [(t-Bu)(2)P(OH)PdCl(2)](2), and [[(t-Bu)(2)PO...H...OP((t-Bu)(2)]PdCl](2) serve as efficient catalysts for a variety of cross-coupling reactions of vinyl and aryl chlorides with arylboronic acids, arylzinc reagents, and thiols to yield the corresponding styrene derivatives, biaryls, and thioethers. (31)P NMR and mechanistic studies argue that the phosphinous acid ligands in the complexes can be deprotonated in the presence of a base to yield an electron-rich anionic species, which is likely a catalyst intermediate, and dimeric [[(t-Bu)(2)PO...H...OP((t-Bu)(2)]PdCl](2) was isolated and cystallographically characterized. These anionic complexes are anticipated not only to accelerate the rate-determining oxidative addition of aryl chlorides but also to stabilize the palladium complexes in the catalytic cycle.
Note on the Role of Mountains in the Energy Budget of the Atmosphere

As a basis for discussing energy conversions in the atmosphere WHITE and SALTZMAN (1956) presented equations for the rate of change of horizontal kinetic energy and total potential and internal energy of an atmosphere in hydrostatic equilibrium. DOI: 10.1111/j.2153-3490.1961.tb00086.x
The Nuclear Pore Complex Has Entered the Atomic Age

Nuclear pore complexes (NPCs) perforate the nuclear envelope and represent the exclusive passageway into and out of the nucleus of the eukaryotic cell. Apart from their essential transport function, components of the NPC have important, direct roles in nuclear organization and in gene regulation. Because of its central role in cell biology, it is of considerable interest to determine the NPC structure at atomic resolution. The complexity of these large, 40–60 MDa protein assemblies has for decades limited such structural studies. More recently, exploiting the intrinsic modularity of the NPC, structural biologists are making progress toward understanding this nanomachine in molecular detail. Structures of building blocks of the stable, architectural scaffold of the NPC have been solved, and distinct models for their assembly proposed. Here we review the status of the field and lay out the challenges and the next steps toward a full understanding of the NPC at atomic resolution.
Families of traveling impulses and fronts in some models with cross-diffusion

Abstract An analysis of traveling wave solutions of partial differential equation (PDE) systems with cross-diffusion is presented. The systems under study fall in a general class of the classical Keller–Segel models to describe chemotaxis. The analysis is conducted using the theory of the phase plane analysis of the corresponding wave systems without a priory restrictions on the boundary conditions of the initial PDE. Special attention is paid to families of traveling wave solutions. Conditions for existence of front–impulse, impulse–front, and front–front traveling wave solutions are formulated. In particular, the simplest mathematical model is presented that has an impulse–impulse solution; we also show that a non-isolated singular point in the ordinary differential equation (ODE) wave system implies existence of free-boundary fronts. The results can be used for construction and analysis of different mathematical models describing systems with chemotaxis.
High-brightness single photon source from a quantum dot in a directional-emission nanocavity

We analyze a single photon source consisting of an InAs quantum dot coupled to a directional-emission photonic crystal (PC) cavity implemented in GaAs. On resonance, the dot’s lifetime is reduced by more than 10 times, to 45ps. Compared to the standard three-hole defect cavity, the perturbed PC cavity design improves the collection efficiency into an objective lens (NA = 0.75) by factor 4.5, and improves the coupling efficiency of the collected light into a single mode fiber by factor 1.9. The emission frequency is determined by the cavity mode, which is antibunched to g^(2)(0) = 0.05. The cavity design also enables efficient coupling to a higher-order cavity mode for local optical excitation of cavity-coupled quantum dots.
Copper-Catalyzed Regiospecific Synthesis of N-Alkylbenzimidazoles

A copper-catalyzed method is described for the preparation of N-alkylbenzimidazoles in regioisomerically pure form starting from o-haloanilines. The method utilizing CuI and trans-N,N'-dimethyl-1,2-cyclohexanediamine allows the preparation of N-alkylbenzimidazoles in good to excellent yields.
Connecting local environmental sequences to global climate patterns: evidence from the hominin-bearing Hadar Formation, Ethiopia.

Abstract Central to the debate surrounding global climate change and Plio-Pleistocene hominin evolution is the degree to which orbital-scale climate patterns influence low-latitude continental ecosystems and how these influences can be distinguished from regional volcano-tectonic events and local environmental effects. The Pliocene Hadar Formation of Ethiopia preserves a record of hominin paleoenvironments from roughly 3.5 to 2.2 Ma at a temporal resolution relevant to evolutionary change within hominins and other taxa. This study integrates the high-resolution sedimentological and paleontological records at Hadar with climate proxies such as marine core isotope, dust, and sapropel records. Consistent cycling observed both between and within fluvial and lacustrine depositional environments prior to 2.9 Ma at Hadar appears to be predominantly climatic in nature. In contrast a significant change in depositional facies after 2.9 Ma to sequences dominated by conglomerate cut-and-fill cycles indicates a strong tectonic signature related to regional developments in the Main Ethiopian Rift. While specific events seen in marine proxy records may have parallels in the Hadar environmental archive, their overall patterns of high versus low variability may be even more relevant. For example, periods of relatively high-amplitude climate oscillations between 3.15 and 2.95 Ma may be linked to noted size-related morphological changes within the Hadar Australopithecus afarensis lineage and a significant increase in more arid-adapted bovid taxa. Increased aridity in East Africa during this period is also indicated by peaks in eolian dust in the marine core record. Conversely, the dominant lacustrine phase at Hadar ca. 3.3 Ma coincides with the least variable period in several climate proxy records, including marine core foraminifera δ18O values and eolian dust concentration. This phase is also coeval with low insolation variability and a very distinct and significant long-term period of low dust percentage in circum-Africa marine cores.
The Dynamics of Plutinos

Plutinos are Kuiper belt objects that share the 3:2 Neptune resonance with Pluto. The long-term stability of Plutino orbits depends on their eccentricity. Plutinos with eccentricities close to Pluto's (fractional eccentricity difference Δe/eP = |e - eP|/eP 0.1) can be stable because the longitude difference librates, in a manner similar to the tadpole and horseshoe libration in co-orbital satellites. Plutinos with Δe/eP 0.3 can also be stable; the longitude difference circulates and close encounters are possible, but the effects of Pluto are weak because the encounter velocity is high. Orbits with intermediate eccentricity differences are likely to be unstable over the age of the solar system, in the sense that encounters with Pluto drive them out of the 3:2 Neptune resonance and thus into close encounters with Neptune. This mechanism may be a source of Jupiter-family comets.
q-ROOK MONOID ALGEBRAS, HECKE ALGEBRAS, AND SCHUR-WEYL DUALITY

When we were at the beginnings of our careers, Sergei's support helped us to believe in our work. He generously encouraged us to publish our results on Brauer and Birman–Murakami–Wenzl algebras, results which had in part, or possibly in total, been obtained earlier by Sergei himself. He remains a great inspiration for us, both mathematically and in our memory of his kindness, modesty, generosity, and encouragement to the younger generation. Bibliography: 19 titles.
Internal Finance and Corporate Investment

This paper examines Pecking Order/Free Cash Flow behavior in small ($25–$50 million), medium ($100–250 million), and large ($1000 million and over) firms. The purpose is to proffer an explanation for the important role of cash flow on the investment expenditure of firms that is more complete than the commonly given accounts. The Pecking order theory (PO) emphasizes the value-enhancing influence of cash flow, while the free cash flow hypothesis (FCF) underscores its value-destroying effect. Using the vector error correction model, we find that although the overall behavior of small firms support the pecking order theory, the cash flow of these firms does not have any causal effect on their investment. We further find evidence of free cash flow theory in large firms.
Hopelessness and Suicidal Ideation in Outpatients With Treatment-Resistant Depression: Prevalence and Impact on Treatment Outcome

Depression and hopelessness are risk factors for suicide. The purpose of this study was to examine the extent of suicidal ideation and hopelessness in outpatients with treatment-resistant depression (TRD) and to study the impact of suicidal ideation and hopelessness on treatment with nortriptyline (NT). The degree of suicidal ideation and hopelessness was assessed during the screen visit with the use of items #3 and #30 of the Hamilton Depression Rating Scale (HAM-D) in 89 patients with TRD who entered a 6-week open trial of NT. Forty of these patients also completed the Beck Hopelessness Index (BHI) during the screen visit. In separate logistic regressions, the scores from the BHI and the two HAM-D items were then tested as predictors of clinical response to the 6-week trial with NT, controlling for the severity of depression. More than half of patients reported thoughts or wishes of death to self and significant hopelessness. A greater degree of hopelessness before treatment in completers, reflected by the score on the HAM-D item #30, predicted response to NT. More than half of patients with prominent hopelessness who completed the trial responded. Patients with TRD are more likely than not to report prominent suicidal ideation and hopelessness. Furthermore, a full 6-week trial of NT, a relatively noradrenergic tricyclic antidepressant, may be particularly useful in patients who have failed to respond to several antidepressants and also report significant hopelessness.
Gravitational Waves from Stellar Collapse: Correlations to Explosion Asymmetries

The collapse of massive stars produces not only observable outbursts across the entire electromagnetic spectrum but, for Galactic (or near-Galactic) supernovae, detectable signals for ground-based neutrino and gravitational-wave detectors. Gravitational waves and neutrinos provide the only means to study the actual engine behind the optical outbursts: the collapsed stellar core. While the neutrinos are most sensitive to details of the equation of state, gravitational waves provide a means to study the mass asymmetries in this central core. We present gravitational-wave signals from a series of three-dimensional core-collapse simulations with asymmetries derived from initial perturbations caused by precollapse convection, core rotation, and low-mode convection in the explosion engine itself. A Galactic supernovae will allow us to differentiate these different sources of asymmetry. Combining this signal with other observations of the supernova, from neutrinos to gamma-rays to the compact remnant, dramatically increases the predictive power of the gravitational-wave signal. We conclude with a discussion of the gravitational-wave signal arising from collapsars, the leading engine for long-duration gamma-ray bursts.
Strong intrabeam scattering in heavy ion and proton beams

Abstract The growth of a beam of particles due to intrabeam scattering has been studied over long periods of time for a beam of gold ions and for a beam of protons, and as a function of the beam energy. In strong intrabeam scattering, the beam dimensions may grow by several-fold, and the accelerator aperture is large enough to contain the beam as it grows. The final state of the beam, after the initial large growth rates have subsided, has certain interesting features. Some simple general results were found to hold in the high energy limit. The dependence of the final beam state on the beam intensity, coupling and the choice of transition energy has also been studied.
Performance of microfinance institutions in Muslim countries

Purpose – The aim of the paper is to analyze whether performance measures and their factors for microfinance institutions (MFIs) in Muslim countries are significantly different from those in their non-Muslim counterparts, central to the Islamic scholars' argument that religious and cultural norms in Muslim countries may drive the preference of Islamic microfinance over conventional microfinance. Design/methodology/approach – Using a cross-sectional dataset of 2,138 firm-years for 754 different MFIs across 83 countries, 33 Organization of Islamic Conference (OIC) member Muslim countries and 50 non-member countries, we analyzed the MFI performance based on three sets of measures: outreach, loan recovery and profitability and overall financial performance measures, with respect to two sets of explanatory variables, namely, country-specific and firm-level variables. Findings – Results show that country gross domestic product size is positively related with profitability, and the percentage of women borrowers ...
Effects of continuous administration of clopidogrel before off-pump coronary artery bypass grafting in patients with acute coronary syndrome.

Background Clopidogrel has become standard treatment after urgent percutaneous coronary revascularization. Due to its enhanced and irreversible platelet inhibition, patients undergoing urgent surgical revascularization have a higher risk of bleeding complications and transfusions. Therefore, the effect of preoperative continuous administration of clopidogrel on the incidence of hemorrhagic complications in patients undergoing off-pump coronary artery bypass surgery with acute coronary syndrome was evaluated. Methods and Results From March 2004 to September 2006, 172 patients with acute coronary syndrome underwent isolated off-pump coronary artery bypass surgery; 70 (40.7%) and 102 (59.3%) of these patients did or did not take clopidogrel before surgery respectively. Seventy patients in each group were matched using propensity scores and associations between preoperative continuous administration of clopidogrel and postoperative bleeding, hemostatic reoperation, blood products received, the need for multiple transfusions and early graft patency by coronary computed tomography were assessed. Univariate analysis showed the continuous clopidogrel group had similar levels of postoperative bleeding for 24 h (601.4±312.6 ml vs 637.2±452.4 ml, p=0.616) and rates of reexploration (1.4% vs 1.4%), perioperative blood transfusion (33.3% vs 34.3%, p>0.05) and platelet transfusion (2.9% vs 7.1%, p=0.44) compared with the non-continuous group. Conclusions Preoperative continuous administration of clopidogrel did not increase the risk of hemorrhagic complications in patients with acute coronary syndrome undergoing isolated off-pump coronary artery bypass surgery. These findings indicate that surgery after clopidogrel treatment in patients with acute coronary syndrome should not be delayed until platelet function returns to normal because they may have a higher risk of recurrent myocardial ischemic events. (Circ J 2008; 72: 626 - 632)
Advanced localization of massive black hole coalescences with LISA

The coalescence of massive black holes is one of the primary sources of gravitational waves (GWs) for LISA. Measurements of the GWs can localize the source on the sky to an ellipse with a major axis of a few tens of arcminutes to a few degrees, depending on source redshift, and a minor axis which is 2―4 times smaller. The distance (and thus an approximate redshift) can be determined to better than a per cent for the closest sources we consider, although weak lensing degrades this performance. It will be of great interest to search this three-dimensional 'pixel' for an electromagnetic counterpart to the GW event. The presence of a counterpart allows unique studies which combine electromagnetic and GW information, especially if the counterpart is found prior to final merger of the holes. To understand the feasibility of early counterpart detection, we calculate the evolution of the GW pixel with time. We find that the greatest improvement in pixel size occurs in the final day before merger, when spin precession effects are maximal. The source can be localized to within 10 square degrees as early as a month before merger at z = 1; for higher redshifts, this accuracy is only possible in the last few days.
Quantitative stratification and the regularity of harmonic map flow

In this paper, we prove estimates and quantitative regularity results for the harmonic map flow. First, we consider \(H^1_\mathrm{loc }\)-maps \(u\) defined on a parabolic ball \(P\subset M^m\times \mathbb {R}\) and with target manifold \(N\), that have bounded Dirichlet-energy and Struwe-energy. We define a quantitative stratification, which groups together points in the domain into quantitative weakly singular strata \(\mathcal {S}^j_{\eta ,r}(u)\) according to the number of approximate symmetries of \(u\) at certain scales. We prove that their tubular neighborhoods have small volume, namely \(\mathrm{Vol}\left( T_r(\mathcal {S}^j_{\eta ,r}(u))\right) \le Cr^{m+2-j-\varepsilon }\), where \(C\) depends on \(\eta , \epsilon \) and some additional parameters; for the precise statement see Theorem 1.5. In particular, this generalizes the known Hausdorff estimate \(\dim \mathcal {S}^j(u)\le j\) for the weakly singular strata of suitable weak solutions of the harmonic map flow. As an application, specializing to Chen-Struwe solutions with target manifolds that do not admit certain harmonic and quasi-harmonic spheres, we obtain refined Minkowski estimates for the singular set, which generalize a result of Lin-Wang (Anal Geom 7(2):397–429, 1999). We also obtain \(L^p\)-estimates for the reciprocal of the regularity scale. Our results for harmonic map flow are analogous to results for mean curvature flow we proved in Cheeger et al. (Geom Funct Anal 23(3):828–847, 2013).
Self-administration of subcutaneous depot medroxyprogesterone acetate by adolescent women

Background Intramuscular depot medroxyprogesterone acetate (DMPA-IM) is now available in subcutaneous (SC) formulation, potentially allowing for home-based self-administration. We examined adolescents’ interest in and proficiency at DMPA-SC self-administration.
Neural network adaptive control for nonlinear nonnegative dynamical systems

Nonnegative and compartmental dynamical system models are derived from mass and energy balance considerations that involve dynamic states whose values are nonnegative. These models are widespread in engineering and life sciences and typically involve the exchange of nonnegative quantities between subsystems or compartments wherein each compartment is assumed to be kinetically homogeneous. In this paper, we develop a full-state feedback neural adaptive control framework for adaptive set-point regulation of nonlinear uncertain nonnegative and compartmental systems. The proposed framework is Lyapunov-based and guarantees ultimate boundedness of the error signals corresponding to the physical system states and the neural network weighting gains. In addition, the neural adaptive controller guarantees that the physical system states remain in the nonnegative orthant of the state-space for nonnegative initial conditions.
Finding Black Holes with Microlensing

The MACHO and OGLE collaborations have argued that the three longest duration bulge microlensing events are likely caused by nearby black holes, given the small velocities measured with microlensing parallax and nondetection of the lenses. However, these events may be due to lensing by more numerous lower mass stars at greater distances. We find a posteriori probabilities of 76%, 16%, and 4% that the three longest events are black holes, assuming a Salpeter initial mass function (IMF) and a 40 M☉ cutoff for neutron star progenitors; the numbers depend strongly on the assumed mass function but favor a black hole for the longest event for most standard IMFs. The longest events (>600 days) have an a priori ~26% probability of being black holes for a standard mass function. We propose a new technique for measuring the lens mass function using the mass distribution of long events measured with the Advanced Camera for Surveys on the Hubble Space Telescope, the Very Large Telescope Interferometer, the Space Interferometry Mission, or the Global Astrometric Interferometer for Astrophysics.
Measuring Market Power in Food- Processing Industries: Discussion

Focuses on the measurement of market power in the beef processing industry in the United States. Causal linkage between concentrated industrial structure and antisocial economic performance; Structure-conduct-performance paradigm; Basic model for fed-cattle studies.
Efficient and robust geocasting protocols for sensor networks

Geocasting is the delivery of packets to nodes within a certain geographic area. For many applications in wireless ad hoc and sensor networks, geocasting is an important and frequent communication service. The challenging problem in geocasting is distributing the packets to all the nodes within the geocast region with high probability but with low overhead. According to our study we notice a clear tradeoff between the proportion of nodes in the geocast region that receive the packet and the overhead incurred by the geocast packet especially at low densities and irregular distributions. We present two novel protocols for geocasting that achieve high delivery rate and low overhead by utilizing the local location information of nodes to combine geographic routing mechanisms with region flooding. We show that the first protocol Geographic-Forwarding-Geocast (GFG) has close-to-minimum overhead in dense networks and that the second protocol Geographic-Forwarding-Perimeter-Geocast (GFPG) provides guaranteed delivery without global flooding or global network information even at low densities and with the existence of region gaps or obstacles. An adaptive version of the second protocol (GFPG*) has the desirable property of perfect delivery at all densities and close-to-minimum overhead at high densities. We evaluate our mechanisms and compare them using simulation to other proposed geocasting mechanisms. The results show the significant improvement in delivery rate (up to 63% higher delivery percentage in low density networks) and reduction in overhead (up to 80% reduction) achieved by our mechanisms. We hope for our protocols to become building block mechanisms for dependable sensor network architectures that require robust efficient geocast services.
Concentration of the Spectral Measure for Large Random Matrices with Stable Entries

We derive concentration inequalities for functions of the empirical measure of large random matrices with infinitely divisible entries, in particular, stable or heavy tails ones. We also give concentration results for some other functionals of these random matrices, such as the largest eigenvalue or the largest singular value.
Inter- and intramolecular biaryl couplings via cyanocuprate intermediates

Abstract Low temperature oxidations of selected higher order cyanocuprates composed of one or two heteroaromatic ligands can be oxidatively coupled in an inter- or intramolecular fashion to afford unsymmetrical biaryls. Non-heteroaromatic systems have also been studied in related intramolecular processes.
Space-Efficient Algorithms for Reachability in Surface-Embedded Graphs

This work presents a log-space reduction which compresses an $n$-vertex directed a cyclic graph with $m(n)$ sources embedded on a surface of genus $g(n)$, to a graph with $O(m(n)+g(n))$ vertices while preserving reach ability between a given pair of vertices. Applying existing algorithms to this reduced graph yields new deterministic algorithms with improved space bounds as well as improved simultaneous time-space bounds for the reach ability problem over a large class of directed a cyclic graphs. Specifically, it significantly extends the class of surface-embedded graphs with log-space reach ability algorithms: from planar graphs with $O(\log n)$ sources, to graphs with $2^{O(\sqrt{\log n})}$ sources embedded on a surface of genus $2^{O(\sqrt{\log n})}$. Additionally, it yields an $O(n^{1-\epsilon})$ space algorithm with polynomial running time for reach ability over graphs with $O(n^{1-\epsilon})$ sources embedded on surfaces of genus $O(n^{1-\epsilon})$.
Vitreo-retinal traction and anastrozole use

Purpose This study tested a prediction stemming from the hypothesis that anastrozole users experience heightened vitreo-retinal traction. This hypothesis was based on the knowledge that menopause increases the risk of intraocular tractional events such as posterior vitreous detachments (PVDs). Methods Retinal thickness was measured for 3 groups of amenorrheic women: (1) anastrozole users and (2) tamoxifen users undergoing adjuvant therapy for early-stage breast cancer, and (3) control subjects not using hormonal medication. Foveal shape indices were derived for subjects without PVDs. Results For anastrozole users, the distance to the temporal side of the fovea became less than the distance to the nasal side at a sufficient height above the foveal base. This effect did not exist for control subjects; the between-group difference was appreciable. Results concerning tamoxifen users were inconclusive. Conclusions The foveas of women using anastrozole appear to be subjected to more tractional force than are the foveas of women not using any hormonal medication.
Kinetics of the gas‐phase reactions of NO3 radicals with a series of alkynes, haloalkenes, and α,β‐unsaturated aldehydes

Rate constants for the gas-phase reactions of NO3 radicals with a series of alkynes, haloalkenes, and α,β-unsaturated aldehydes have been determined at 298 ± 2 K using a relative rate technique. Using rate constants for the reactions of NO3 radicals with ethene and propene of (1.1 ± 0.5) × 10−16 cm3 molecule−1 s−1 and (7.5 ± 1.6) × 10−15 cm3 molecule−1 s−1, respectively, the following rate constants (in units of 10−16 cm3 molecule−1 s−1) were obtained: acetylene, ≤0.23; propyne, 0.94 ± 0.44; vinyl chloride, 2.3 ± 1.1; 1,1-dichloroethene, 6.6 ± 3.1; cis-1,2-dichloroethene, 0.75 ± 0.35; trans-1,2-dichloroethene, 0.57 ± 0.27; trichloroethene, 1.5 ± 0.7; tetrachloroethene, <0.4; allyl chloride, 2.9 ± 1.3; acrolein, 5.9 ± 2.8; and crotonaldehyde, 41 ± 9. The atmospheric implications of these data are discussed.
Modeling state-level water quality management: the case of the Neuse River Basin

Abstract This research considers how the perceived costs of achieving water quality objectives are sensitive to three issues surrounding model structure and policy design. These issues include: (i) the extent of the regulated market, (ii) the responsibility of the regulated market for background pollution, and (iii) the use of alternative policy instruments. A large-scale process model is used to evaluate and compare the costs of nutrient reduction in the Neuse River Basin in North Carolina under various instruments, including a plan currently being considered by state regulators. The results emphasize the importance of flexibility in both model structure and policy design.
Working Expectations: Frame Diagnosis and the Welfare Rights Movement

This paper examines frame resonance dynamics internal to the contemporary US welfare rights movement. Frames diagnosing the problems of welfare as rooted in conceptions of caregiving and wage work were popular a generation ago among welfare rights activists. Today, this frame is favored among allies of the movement. Is it favored among grassroots activists? Forty-three interviews with welfare rights parent/activists in eight states around the USA reveal that activists have prioritized the immediate needs of welfare families. In examining the mechanisms underlying this disjuncture in frame resonance, I find that a caring labor frame ultimately lacks both credibility and salience among activists. Moreover, these established conceptions of resonance tend to minimize the intertwined role of power and identity in the perception of framing choices available to activists. This tendency of framing literature to present identity categories such as race, class and gender as ultimately interchangeable masks the crit...
Superlattice patterns in surface waves

Abstract We report novel superlattice wave patterns at the interface of a fluid layer driven vertically. These patterns are described most naturally in terms of two interacting hexagonal sublattices. Two frequency forcing at very large aspect ratio is utilized in this work. A superlattice pattern (“superlattice-I”) consisting of two hexagonal lattices oriented at a relative angle of 22° is obtained with a 6:7 ratio of forcing frequencies. Several theoretical approaches that may be useful in understanding this pattern have been proposed. In another example, the waves are fully described by two superimposed hexagonal lattices with a wavelength ratio of 3 , oriented at a relative angle 30°. The time dependence of this “suoerlattice-II” wave pattern is unusual. The instantaneous patterns reveal a time-periodic stripe modulation that breaks the sixfold symmetry at any instant, but the stripes are absent in the time average. The instantaneous patterns are not simply amplitude modulations of the primary standing wave. A transition from the superlattice-II state to a 12-fold quasi-crystalline pattern is observed by changing the relative phase of the two forcing frequencies. Phase diagrams of the observed patterns (including superlattices, quasicrystalline patterns, ordinary hexagons, and squares) are obtained as a function of the amplitudes and relative phases of the driving accelerations.
Thermal Activation of Silica at Temperatures Below 500°C

Abstract A simple low-temperature treatment (below 500°C) of several types of silica was found to induce catalytic activity toward hydrogen-deuterium exchange, the degree of which was measured with a pulse-flow microreactor. Silica samples were heated in a microreactor in the presence of an argon carrier gas. Pulses of hydrogen and deuterium gas mixtures were injected into the flow and the effluent stream was monitored for H2, D2, and HD. In some cases equilibrium amounts of the effluent gases were observed. Activation of the silicas appeared to be related to the dehydration of the silica surfaces. After activation, the surface of one of the silicas, Cabosil M5, was found to catalyze the hydrogenation of ethylene to ethane and to catalyze extensive exchange when deuterium was used as the hydrogenation reagent.
(η6-Benzene)(η5-ethyltetramethylcyclopentadienyl)rhodium (III) hexafluorophosphate: A reagent for catalytic phenol oxidative coupling

Abstract Reaction of p-cresol with the title catalyst (10 mol %), cesium carbonate, and bromobenzene at 90°C gave 2,2′-dihydroxybiphenyl (51–67%). The reaction was extended to other phenols to provide the corresponding o,o′-dimers (15–59%).
Broken SU(4) symmetry and the fractional quantum hall effect in graphene

We describe a variational theory for incompressible ground states and charge gaps in the N=0 Landau level of graphene that accounts for the fourfold Landau level degeneracy and the short-range interactions that break SU(4) spin-valley invariance. Our approach explains the experimental finding that gaps at odd numerators are weak for 1<|ν|<2 and strong for 0<|ν|<1. We find that in the SU(4) invariant case the incompressible ground state at |ν|=1/3 is a three-component incompressible state, not the Laughlin state, and discuss the competition between these two states in the presence of SU(4) spin-valley symmetry-breaking terms.
Expanding Insight into Asymmetric Palladium‐Catalyzed Allylic Alkylation of N‐Heterocyclic Molecules and Cyclic Ketones

Eeny, meeny, miny ... enaminones! Lactams and imides have been shown to consistently provide enantioselectivities substantially higher than other substrate classes previously investigated in the palladium-catalyzed asymmetric decarboxylative allylic alkylation. Several new substrates have been designed to probe the contributions of electronic, steric, and stereoelectronic factors that distinguish the lactam/imide series as superior alkylation substrates (see scheme). These studies culminated in marked improvements on carbocyclic allylic alkylation substrates.
Kakeya sets in Cantor directions

We construct a union of N parallelograms of dimensions approximately 1/N x 1 in the plane, with the slope of their long sides in the standard Cantor set. The union has area 1/log N but the union of the doubles has area log log N/ log N. In particular, this implies unbounded of the associated maximal operator in L^p for any p different from infinity. The construction is by randomizing an earlier construction of the second author for the L^2 case. The proof that the construction satisfies the desired conditions is by elementary estimates in the theory of percolation on trees as developed by R. Lyons.
Comparison of vertical profile turbulence structure with stellar observations.

Vertical profiles of microthermal turbulence structure have been obtained from balloon flights to altitudes near 25 km above mean sea level. Comparison of the observed turbulence structure with meteorological data and simultaneously acquired stellar scintillation data has been successful. For this comparison integrals over the observed turbulence structure were computed as required by theory. Turbulence and wind velocity data were also employed to predict successfully stellar irradiance spectra.
Synthesis of the trisaccharide portion of the immunologic adjuvant QS-21A via sulfonium-mediated oxidative and dehydrative glycosylation.

The first synthesis of the trisaccharide fragment of the potent immunologic adjuvant QS-21A is reported. The key steps involve the application of sulfonium-mediated oxidative and dehydrative glycosidic couplings to construct the anomeric linkages in a short and convergent assembly of the branched trisaccharide.
SEARCH FOR MAGNETIC MONOPOLES IN THE MOON.

The effects of a possible magnetic charge of the moon upon the magnetic field in the lunar vicinity have been analyzed. Magnetic field observations obtained by the GSFC magnetometer aboard Explorer 35 have been studied to search for these effects. Using these observations, it is possible to obtain a measure of the net difference between the number of northern and southern monopoles within the moon which are of opposite sign. The search has resulted in negative findings and places an approximate upper limit on the average difference in the number of monopoles within the moon at 1.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}7}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ or 7\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}32}$ per nucleon.
Shearing Box Simulations of the MRI in a Collisionless Plasma

We describe local shearing box simulations of turbulence driven by the magnetorotational instability (MRI) in a collisionless plasma. Collisionless effects may be important in radiatively inefficient accretion flows, such as near the black hole in the Galactic center. The MHD version of ZEUS is modified to evolve an anisotropic pressure tensor. A fluid closure approximation is used to calculate heat conduction along magnetic field lines. The anisotropic pressure tensor provides a qualitatively new mechanism for transporting angular momentum in accretion flows (in addition to the Maxwell and Reynolds stresses). We estimate limits on the pressure anisotropy due to pitch angle scattering by kinetic instabilities. Such instabilities provide an effective "collision" rate in a collisionless plasma and lead to more MHD-like dynamics. We find that the MRI leads to efficient growth of the magnetic field in a collisionless plasma, with saturation amplitudes comparable to those in MHD. In the saturated state, the anisotropic stress is comparable to the Maxwell stress, implying that the rate of angular momentum transport may be moderately enhanced in a collisionless plasma.
A study on the possible utilization of immunodiffusion and immunofluorescence techniques as the diagnostic methods for American foulbrood of honeybees (Apis mellifera)

Abstract Four types of antisera were obtained from rabbits hyperimmunized with either spores or vegetative rods from two strains of the American foulbrood pathogen, Bacillus larvae . The specificity and sensitivity of these antisera were tested with immunofluorescence and immunodiffusion methods. No cross-reactions were observed between the antisera and other different species of Bacillus or different genera of bacteria. The specificity was not found between the antisera and two strains of B. larvae although stronger fluorescent intensity was observed between the antiserum and its corresponding strain of antigen in the immunofluorescence tests. Eight samples of 1- to 2-day-old larvae, 3- to 4-day-old larvae, decayed tissue, and dry remain, collected from eight infected colonies, were tested against antisera by the immunofluorescence and the immunodiffusion methods. The results indicated that both methods are sensitive and specific for making diagnosis of field samples of American foulbrood of honey bees.
Effects of Satellite Dimensions in the Solar Pressure Formulation for Formation Flying

additional term containing the effects of the solar pressure force which is expressed with Karmyov’s theory 5 . In Karmyov’s theory, the solar pressure force is based on the reflectivity coefficient of the surface of the assumed opaque satellite. Previously, the authors 1 studied how the difference in the reflectivity coefficient between a pair of satellites within a constellation varies the amount of control effort when the satellite dimensions were the same. In Ref. 1, an increment in the difference of the reflectivity coefficient will increase the amount of control effort required to maintain the separation distance conditions between any pair of satellites within a constellation. In the present study, the reflectivity coefficient will be maintained the same for a pair of satellites within a constellation, but the satellite dimensions will be varied. This variation in the satellite dimensions will show that the amount of control effort required for the correction of the separation distance constraints between a pair of satellites will be larger than the previous case 1 when the reflectivity coefficient changes and the satellite dimensions are the same. Because of the results that will be presented in this research work, it will be shown that the pair of satellites within a constellation should be constructed with very similar characteristics in the dimension and surface properties such that the solar pressure force will not disturb their motion in a highly elliptical orbit.
Quantum invariants of 3-manifolds: Integrality, splitting, and perturbative expansion

Abstract We consider quantum invariants of 3-manifolds associated with arbitrary simple Lie algebras. Using the symmetry principle we show how to decompose the quantum invariant as the product of two invariants, one of them is the invariant corresponding to the projective group. We then show that the projective quantum invariant is always an algebraic integer, if the quantum parameter is a prime root of unity. We also show that the projective quantum invariant of rational homology 3-spheres has a perturbative expansion a la Ohtsuki. The presentation of the theory of quantum 3-manifold invariants is self-contained.
Occultation of the T Tauri Star RW Aurigae A by its Tidally Disrupted Disk

RW Aur A is a classical T Tauri star, believed to have undergone a reconfiguration of its circumstellar environment as a consequence of a recent flyby of its stellar companion, RW Aur B. This interaction stripped away part of the circumstellar disk of RW Aur A, leaving a tidally disrupted arm and a short truncated circumstellar disk. We present photometric observations of the RW Aur system from the Kilodegree Extremely Little Telescope survey showing a long and deep dimming that occurred from 2010 September until 2011 March. The dimming has a depth of ~2 mag, a duration of ~180 days, and was confirmed by archival observations from American Association of Variable Star Observers. We suggest that this event is the result of a portion of the tidally disrupted disk occulting RW Aur A, specifically a fragment of the tidally disrupted arm. The calculated transverse linear velocity of the occulter is in excellent agreement with the measured relative radial velocity of the tidally disrupted arm. Using simple kinematic and geometric arguments, we show that the occulter cannot be a feature of the RW Aur A circumstellar disk, and we consider and discount other hypotheses. We also place constraints on the thickness and semimajor axis of the portion of the arm that occulted the star.
Lesch-Nyhan Disease

Lesch-Nyhan disease is the most severe or complete phenotype of deficiency in hypoxanthineguanine phosphoribosyltransferase; other variant enzymes are found in patients without abnormality in behavior or mental development, and there are intermediate phenotypes in which enzyme activity is intermediate. A considerable number and variety of mutations in the HPRT gene have been discovered.