cssi/SciSciGPT-SciSciNet huggingface dataset:
Learning Visual Feature Detectors for Obstacle Avoidance using Genetic Programming

In this paper, we describe the use of Genetic Programming (GP) techniques to learn a visual feature detection for a mobile robot navigation task. We provide experimental results across a number of different environments, each with different characteristics, and draw conclusions about the performance of the learned feature detector. We also explore the utility of seeding the initial population with a previously evolved individual, and discuss the performance of the resulting individuals.
Impact of Source Terms on Reliability of CFD Algorithms

Source terms often appear in various fluid dynamic problems. These source terms not only have an important impact on the physics of the flow but they can also impact the reliability of CFD algorithms. A general recommendation for differencing negative value sources (sinks) is to treat them implicitly, while positive value sources (sources) should be evaluated explicitly. Although this provides improvements compared with evaluating all terms in the same manner, sources with positive values, in particular, often cause convergence difficulties. The present paper addresses the reasons for these difficulties and combines a new source term evaluation method with time step limitation for convection and diffusion terms to give more robust capability. The method is verified by a combination of stability analysis followed by computational experiments to validate the stability findings in meaningful problems. The source Jacobian arising from a twoequation k-� turbulence model is taken as an example to demonstrate our findings.
Qualitative criterion for interception in a pursuit/evasion game

A qualitative account is given of a differential pursuit/evasion game. A criterion for the existence of an intercept solution is obtained using future cones that contain all attainable trajectories of target or interceptor originating from an initial position. A sufficient and necessary conditon that an opportunity to intercept always exists is that, after some initial time, the future cone of the target be contained within the future cone of the interceptor. The sufficient condition may be regarded as a kind of Nash equilibrium.
Nine hexagonal Ca5Pb3Z phases in stuffed Mn5Si3-Type structures with transition metal interstitial atoms Z. problems with classical valence states in possible Zintl phases

Ternary hexagonal Ae(5)Tt(3)Z phases have been obtained from high-temperature reactions (1000-1300 degrees C in Ta) only for Ae (alkaline-earth metal) = Ca, Tt (tetrel) = Pb, and Z = V, Cr, Mn, Fe, Co, Ni, Zn, Ru, or Cd. The hexagonal crystal structures (stuffed Mn(5)Si(3)-type, P6(3)/mcm, Z = 2) were refined for Z = Mn and Fe (a = 9.3580(3), 9.3554(5) A, c = 7.009(1), 7.009(1) A, respectively). In contrast, Ca(5)Pb(3)Z for Z = Cu or Ag form only with a trigonal structure (P3c1, Z = 2, a = 9.4130(3) A, c = 7.052(1) A for Cu) in which regular displacements of only the linear strings of Ca1 atoms occur. The existence of these compounds stands in contrast to the nonexistence of all binary Ae(5)Tt(3) products from Ca to Ba (Ae) and Si to Pb (Tt) with a Mn(5)Si(3)-type structure. Therefore, it once seemed attractive to consider the Z elements in these Ca(5)Pb(3)Z compounds as reducing agents (electron donors). The Mn and Fe structures appropriately exhibit greatly enlarged antiprismatic calcium cavities about Z. Other indications of relatively electron-poor environments around Fe are found in its properties, which include soft ferromagnetism with an elevated magnetic moment (6.3 micro(B)) and a large Fe 3p(3/2) binding energy relative to that in La(5)Ge(3)Fe, La(15)Ge(9)Fe, etc. The Ca(5)Pb(3)Mn phase exhibits metallic behavior (rho(295) = 135 microOmega cm) and temperature-independent Pauli paramagnetism. These properties are supported by ab initio band structure calculations for Ca(5)Pb(3)Mn, which show strong Ca-Pb bonding and a broad Pb-based band, with appreciable Ca-Mn and Ca-Pb bonding states at and above E(F). Distortion of the Cu analogue gives strengthened Ca-Pb bonding and reduced Cu-Ca1 repulsions. A Zintl phase description of these compounds and some related compounds in terms of closed Pb bands is not appropriate.
Adverse drug events caused by serious medication administration errors

Objective: To determine how often serious or lifethreatening medication administration errors with the potential to cause harm (potential adverse drug events) result in actual harm (adverse drug events (ADEs)) in the hospital setting. Design: Retrospective chart review of clinical events following observed medication administration errors. Background: Medication errors are common at the medication administration stage for inpatients. While many errors can cause harm, it is unclear exactly how often. Methods: In a previous study where 14 041 medication administrations were directly observed, 1271 medication administration errors were discovered, of which 133 had the potential to cause serious or life-threatening harm and were considered serious or life-threatening potential adverse drug events. As a follow-up, clinical reviewers conducted detailed chart review of serious or life-threatening potential ADEs to determine if they caused an ADE. Reviewers assessed severity of the ADE and attribution to the error. Results: Ten (7.5% (95% CI 6.98 to 8.01)) actual ADEs resulted from the 133 serious and life-threatening potential ADEs, of which 6 resulted in significant, three in serious, and one life threatening injury. Therefore 4 (3% (95% CI 2.12 to 3.6)) of serious or life threatening potential ADEs led to serious or life threatening ADEs. Half of the ADEs were caused by dosage or monitoring errors for anti-hypertensives. Conclusions: Unintercepted potential ADEs at the medication administration stage can cause serious patient harm. At hospitals where 6 million doses are administered per year, about 4000 preventable ADEs would be attributable to medication administration errors annually.
Privatization benefits in Eastern Europe

Abstract We document changes in the performance of over 6000 privatized and state-owned manufacturing enterprises in seven Eastern European countries over the initial transition period. We find that privatization is associated with significant increases in sales revenues and labor productivity, and, to a lesser extent, with fewer job losses. The positive effect of privatization is stronger in economic magnitude and statistical significance as the time elapsed since privatization increases. Enterprises privatized for less than 2 years have labor productivity growth similar to that of state-owned enterprises. In contrast, enterprises privatized for 3 or more years significantly outperform state-owned enterprises. The results are robust to the use of alternative econometric specifications (fixed effects, cluster effects, and random effects), and survive in six of the seven individual country samples (the exceptions being Hungary for sales growth and Romania for labor productivity growth).
Impact angle control of interplanetary shock geoeffectiveness

We use Open Geospace General Circulation Model global MHD simulations to study the nightside magnetospheric, magnetotail, and ionospheric responses to interplanetary (IP) fast forward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30° in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along the Sun-Earth line, with the same Mach number as IOS-1. We find that, in the IOS-1 case, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the FPS compresses the magnetotail from both sides symmetrically. This compression triggers a substorm allowing a larger amount of stored energy in the magnetotail to be released to the nightside ionosphere, resulting in stronger geomagnetic activity. By comparing IOS-2 and FPS, we find that, despite the IOS-2 having a larger Mach number, the FPS leads to a larger geomagnetic response in the nightside ionosphere. As a result, we conclude that IP shocks with similar upstream conditions, such as magnetic field, speed, density, and Mach number, can have different geoeffectiveness, depending on their shock normal orientation.
Tunable dispersion and dispersion slope compensators for 10 Gb/s using all-pass multicavity etalons

We propose and demonstrate a novel approach to multichannel tunable dispersion compensation based on multicavity etalons that can compensate all channels throughout the C- or L-band with either 50- or 100-GHz channel spacings for 10-Gb/s applications. We demonstrate very low group delay ripple, large tuning range, as well as dispersion slope compensation for LEAF and TrueWave RS fiber across the L-band. In addition, we indicate that scaling the bandwidth for 40-Gb/s applications is readily achievable.
The graphical lasso: New insights and alternatives.

The graphical lasso [5] is an algorithm for learning the structure in an undirected Gaussian graphical model, using l1 regularization to control the number of zeros in the precision matrix Θ = Σ-1 [2, 11]. The R package GLASSO [5] is popular, fast, and allows one to efficiently build a path of models for different values of the tuning parameter. Convergence of GLASSO can be tricky; the converged precision matrix might not be the inverse of the estimated covariance, and occasionally it fails to converge with warm starts. In this paper we explain this behavior, and propose new algorithms that appear to outperform GLASSO. By studying the "normal equations" we see that, GLASSO is solving the dual of the graphical lasso penalized likelihood, by block coordinate ascent; a result which can also be found in [2]. In this dual, the target of estimation is Σ, the covariance matrix, rather than the precision matrix Θ. We propose similar primal algorithms P-GLASSO and DP-GLASSO, that also operate by block-coordinate descent, where Θ is the optimization target. We study all of these algorithms, and in particular different approaches to solving their coordinate sub-problems. We conclude that DP-GLASSO is superior from several points of view.
Nanophotonics for information systems

This paper explores the role of nanotechnology with focus on nanophotonics in dielectric, metal, and semiconductor inhomogeneous composition materials, devices and subsystems for optical communications, information and signal processing, and sensing.
Tricarbonyl(tropone)iron as a useful functionalized enone equivalent

Abstract Tricarbonyl(tropone)iron has been shown to undergo reactions that are characteristic of an isolated enone.
Reactions of azepinones with electrophiles

Abstract Azepinones are available via a one-pot cycloaddition-ring expansion reaction sequence in good yield. The reactions of azepinones with alkyl halides and epoxides were studied. We report herein protocols for the alkylation of azepinones at nitrogen with alkyl halides and epoxides and the isomerizations that occur in the presence of a base. We also report an unexpected ring contraction under oxidative conditions.
Can Heavy WIMPs Be Captured by the Earth

If weakly interacting massive particles (WIMPs) in bound solar orbits are systematically driven into the Sun by solar system resonances (as Farinella and coworkers have shown is the case for many Earth-crossing asteroids), then the capture of high-mass WIMPs by the Earth would be affected dramatically because high-mass WIMPs are captured primarily from bound orbits. WIMP capture would be eliminated for Mx > 630 GeV and would be highly suppressed for Mx 150 GeV. Annihilation of captured WIMPs and anti-WIMPs is expected to give rise to neutrinos coming from the Earth's center. The absence of such a neutrino signal has been used to place limits on WIMP parameters. At present, one does not know whether typical WIMP orbits are in fact affected by these resonances. Until this question is investigated and resolved, one must (conservatively) assume that they are. Hence, limits on high-mass WIMP parameters are significantly weaker than was previously believed.
Universal constructions for large objects

We present lock-free and wait-free universal constructions for implementing large shared objects. Most previous universal constructions require processes to copy the entire object state, which is impractical for large objects. Previous attempts to address this problem require programmers to explicitly fragment large objects into smaller, more manageable pieces, paying particular attention to how such pieces are copied. In contrast, our constructions are designed to largely shield programmers from this fragmentation. Furthermore, for many objects, our constructions result in lower copying overhead than previous ones. Fragmentation is achieved in our constructions through the use of load-linked, store-conditional, and validate operations on a "large" multiword shared variable. Before presenting our constructions, we show how these operations can be efficiently implemented from similar one-word primitives.
Signed-Rank Tests for Censored Matched Pairs

Abstract I consider the problem of testing bivariate symmetry in matched-pair experiments where the observations are subject to univariate censoring. Thus the observable random variables are given by (Y 1, Y 2) and (δ1, δ2), where Y j = min(X j , C) and δ j = I(X j ≤ C) (j = 1, 2). Here (X 1, X 2) is a random pair of partially observable lifetimes and C is a fixed or random censoring variable. The hypothesis to be tested is that (X 1, X 2) and (X 2, X 1) have the same distribution. Following Woolson and Lachenbruch (1980), I consider censored data generalizations of signed-rank tests such as the sign, signed Wilcoxon, and signed-normal scores tests. I derive the asymptotic distribution of these test statistics under fixed and contiguous alternatives. The efficiencies of the signed-rank tests are considered in a log-linear model and compared with efficiencies of the paired Prentice-Wilcoxon and log-rank tests.
Mode Shape Identification and Orthogonalization

An identification procedure to improve the mass-weighted orthogonality of measured mode shapes is introduced. The procedure takes into account the degree of mode isolation present during measurement. This is accomplished by establishing a set of new mode shapes, from the measured vectors, that satisfy cross-orthogonality constraints and are a minimum deviation from the measured data. A significant feature is that each measured mode, from which improved modes are identified, can be established using different excitation locations and force levels. This allows the procedure to improve the isolation of modes measured with multishaker sine-dwell testing techniques. Nomenclature [A]j = defined in Eq. (19) [B]j = defined in Eq. (19) [C]j = defined in Eq. (19) [C}j = defined in Eq. (15) [F] = excitation force levels Fje =j! element of [F] [G]j = defined in Eq. (19) [G]j =yth column of [G] [H]j = defined in Eq. (19) [7\j = defined by Eq. (12) L = Lagrange function [M] =mass matrix [ w\ = weighting matrix oijj = defined by Eq. (4) [0] = eigenvalues of [0] T[M] [0] f = critical damping ratio [0] = eigenvectors of [0] T[M] [0] [X] = matrix of Lagrange multipliers X^ = element of & of [X], Lagrange multiplier [\}j =yth row of [X] [$] = all the normal modes of a structure [0] = identified mode shapes [0] = analytically orthogonalized mode shapes [0m] = measured modes [0]y =yth column of [0] 0/A: =jk element of [0] 0$ =jk element of [0 m] M = defined by Eq. (17) [fi] = admittance matrix, imaginary components Q// = U element of [ft] [Q\l = defined in Eq. (9) coy = frequency of excitation, rad/s
Photocyclization of ortho-benzoyl N-alkylanilinium ions

Abstract Ortho-benzoyltrimethylanilinium tetrafluoroborate efficiently photo-cyclizes by triplet state δ-hydrogen abstraction to the 1,1-dimethyl-3-hydroxy-3-phenyl-2,3-dihydroindolium salt both in acetonitrile solution and as a solid. Ortho-benzoyI-N,N-dibenzylaniline hydrochloride photocyclizes in acetonitrile to N-benzyl-2,3-diphenylindole. The rate constant for δ-hydrogen abstraction is high thanks to a favorable geometry but rapid internal quenching lowers the quantum yield to only 0.02. Both reactions proceed essentially quantitatively.
Concurrent engineering tools: are the human issues being ignored?

Concurrent engineering (CE) tools are intended to increase the concurrency of multidisciplinary design by integrating various enabling technologies such as computer-aided design, computer-aided manufacturing, group decision support systems, expert systems, and communication networks. If the long term viability of CE depends on effectively developing and deploying CE tools, the assumptions about how CE design tasks are most successfully performed and the roles of tools in facilitating that work should be carefully reviewed. This paper identifies the human factors assumptions made by the CE tool development community and compares them to conclusions drawn from existing literature on the role of technologies in performing technical work. This comparison suggests that the assumptions made by the CE tool development community are likely to inhibit CE tools from successfully enabling the CE process. Recommendations for remedying this state of affairs are offered in the form of restated assumptions that are consistent with documented behaviors of people using similar technologies and potential development strategies for CE tool developers.
Elimination of nonlinear polarization rotation in twisted fibers

It has been previously reported that it is possible to eliminate nonlinear polarization rotation in elliptically birefringent optical fibers. We show that the same can hold true in twisted optical fibers, even though the local eigenmodes are linearly polarized, if the twist length becomes equal to 2 times the beat length. The physical requirements are that the beat length must be short compared with the walk-off length, the dispersive scale length, and the nonlinear scale length. When the twist length becomes comparable with the beat length, the twisting leads to a linear coupling between the two polarizations through their time derivatives.
Mining Attribute-Based Access Control Policies from Logs

Attribute-based access control ABAC provides a high level of flexibility that promotes security and information sharing. ABAC policy mining algorithms have potential to significantly reduce the cost of migration to ABAC, by partially automating the development of an ABAC policy from information about the existing access-control policy and attribute data. This paper presents an algorithm for mining ABAC policies from operation logs and attribute data. To the best of our knowledge, it is the first algorithm for this problem.
New mixing structures of chiral generations in a model with noncompact horizontal symmetry

New mixing structures between chiral generations of elementary particles at low energy are shown in a vectorlike model with a horizontal symmetry SU(1,1). In this framework the chiral model including odd number chiral generations is realized via the spontaneous symmetry breaking of the horizontal symmetry. It is shown that the Yukawa coupling matrices of chiral generations have naturally hierarchical patterns, and in some cases the overall factors of their Yukawa coupling matrices, e.g. the Yukawa coupling constants of the bottom quark and tau lepton are naturally suppressed.
Health reform, population policy and child nutritional status in China

This paper examines the determinants of child nutritional status in seven provinces of China during the 1990s, focusing specifically on the role of two areas of public policy, namely health system reforms and the one child policy. The empirical relationship between income and nutritional status, and the extent to which that relationship is mediated by access to quality healthcare and being an only-child, is investigated using ordinary least squares, random effects, fixed effects, and instrumental variables models. In the preferred model - a fixed effects model where income is instrumented - the author find that being an only-child increases height-for-age z-scores by 0.119 of a standard deviation. The magnitude of this effect is found to be largely gender and income neutral. By contrast, access to quality healthcare and income is not found to be significantly associated with improved nutritional status in the preferred model. Data are drawn from four waves of the China Health and Nutrition Survey.
Beliefs About the Origins of Homosexuality and Support For Gay Rights An Empirical Test of Attribution Theory

In this study, we employ Weiner's attribution theory of controllability to examine beliefs about the origins of homosexuality. If the cause of homosexuality is perceived as controllable (learned, envi ronmental, or an individual choice), negative affect toward homosexuals and reduced support for policies relevant to the group can be expected. If the cause is perceived as uncontrollable (biological or genetic in origin), positive affect and increased support for polices is anticipated. Our anal yses of data from two unique surveys of national adults corroborate these hypotheses, showing that positive feelings toward gays, support for gay civil rights, civil unions, and same-sex marriage are strongly determined by a genetic attribution for homosexuality. Attributions are in fact the strongest predictor of support. We distinguish our analysis from previ ous research by examining the important role of religion, ideology, and experience, in shaping attributions.
β-Catenin deficiency causes DiGeorge syndrome-like phenotypes through regulation of Tbx1

DiGeorge syndrome (DGS) is a common genetic disease characterized by pharyngeal apparatus malformations and defects in cardiovascular, craniofacial and glandular development. TBX1 is the most likely candidate disease-causing gene and is located within a 22q11.2 chromosomal deletion that is associated with most cases of DGS. Here, we show that canonical Wnt—β-catenin signaling negatively regulates Tbx1 expression and that mesenchymal inactivation of β-catenin (Ctnnb1) in mice caused abnormalities within the DGS phenotypic spectrum, including great vessel malformations, hypoplastic pulmonary and aortic arch arteries, cardiac malformations, micrognathia, thymus hypoplasia and mislocalization of the parathyroid gland. In a heterozygous Fgf8 or Tbx1 genetic background, ectopic activation of Wnt—β-catenin signaling caused an increased incidence and severity of DGS-like phenotypes. Additionally, reducing the gene dosage of Fgf8 rescued pharyngeal arch artery defects caused by loss of Ctnnb1. These findings identify Wnt—β-catenin signaling as a crucial upstream regulator of a Tbx1—Fgf8 signaling pathway and suggest that factors that affect Wnt—β-catenin signaling could modify the incidence and severity of DGS.
Supporting excess real-time traffic with active drop queue

Real-time applications often stand to benefit from service guarantees, and in particular delay guarantees. However, most mechanisms that provide delay guarantees also hard-limit the amount of traffic the application can generate, i.e., to enforce to a traffic contract. This can be a significant constraint and interfere with the operation of many real-time applications. Our purpose in this paper is to propose and investigate solutions that overcome this limitation. We have four major goals: 1) guarantee a delay bound to a contracted amount of real-time traffic; 2) transmit with the same delay bound as many excess real-time packets as possible; 3) enforce a given link sharing ratio between excess real-time traffic and other service classes, e.g., best-effort; and 4) preserve the ordering of real-time packets, if required. Our approach is based on a combination of buffer management and scheduling mechanisms for both guaranteeing delay bounds, while allowing the transmission of excess traffic. We evaluate the "cost" of our scheme by measuring the processing overhead of an actual implementation, and we investigate its performance by means of simulations using video traffic traces.
Application of spectral domain Prony's method to the FDTD analysis of planar microstrip circuits

Residual reflection from absorbing boundaries that truncate the computational mesh in the finite-difference time-domain (FDTD) method introduces significant error in the characterization of transmission lines and discontinuities employed in microwave and millimeter-wave integrated circuits. We apply the least squares Prony's method to accurately estimate the complex reflection coefficient (at Mur's absorbing boundary) in the frequency domain by representing the sampled voltages along a microstrip transmission line as a plane wave superposition of incoming and outgoing transverse electromagnetic (TEM) waves at each reference port. Prony's method is used to compute the frequency-dependent effective dielectric constant of a microstrip line and the scattering parameters of microstrip circuit elements, which corroborate well with published and measured results. A new method is discussed to reduce the computer memory required to store the temporal samples which are employed in the spectral processing of the FDTD data. >
Does the Accountable Care Act Aim to Promote Quality, Health, and Control Costs or Has It Missed the Mark? ;Comment on “Health System Reform in the United States”

McDonough’s perspective on healthcare reform in the US provides a clear, coherent analysis of the mix of access and delivery reforms in the Affordable Care Act (ACA) aka Obamacare. As noted by McDonough, this major reform bill is designed to expand access for health coverage that includes both prevention and treatment benefits among uninsured Americans. Additionally, this legislation includes several financial strategies (e.g. incentives and penalties) to improve care coordination and quality in the hospital and outpatient settings while also reducing healthcare spending and costs. This commentary is intended to discuss this mix of access and delivery reform in terms of its potential to achieve the Triple Aim: population health, quality, and costs. Final remarks will include the role of the US federal government to reform the American private health industry together with that of an informed consumer.
Untangling Tanglegrams: Comparing Trees by Their Drawings

A tanglegram is a pair of trees on the same set of leaves with matching leaves in the two trees joined by an edge. Tanglegrams are widely used in biology—to compare evolutionary histories of host and parasite species and to analyze genes of species in the same geographical area. We consider optimization problems in tanglegram drawings. We show a linear time algorithm to decide if a tanglegram admits a planar embedding by a reduction to the planar graph drawing problem. This problem was also studied by Fernau et al. [15]. A similar reduction to a graph crossing problem also helps to solve an open problem they posed, showing a fixed-parameter tractable algorithm for minimizing the number of crossings over all d-ary trees. For the case where one tree is fixed, we show an O(n{\log} n) algorithm to determine the drawing of the second tree that minimizes the number of crossings. This improves the bound from earlier methods. We introduce a new optimization criterion using Spearman's footrule distance and give an O(n^2) algorithm. We also show integer programming formulations to quickly obtain tanglegram drawings that minimize the two optimization measures discussed. We prove lower bounds on the maximum gap between the optimal solution and the heuristic of Dwyer and Schreiber [13] to minimize crossings.
Tunneling through the quantum horizon

The emergence of quantum-gravity induced corrective terms for the probability of emission of a particle from a black hole in the Parikh–Wilczek tunneling framework is studied. It is shown, in particular, how corrections might arise from modifications of the surface gravity due to near horizon Planck-scale effects. Our derivation provides an example of the possible linking between Planck-scale departures from Lorentz invariance and the appearance of higher order quantum gravity corrections in the black-hole entropy-area relation.
Carbon, silicon, germanium, tin and lead

This report surveys publications from the calendar year 2011 in the general area of Group 14 chemistry.
Rounding sum-of-squares relaxations

We present a general approach to rounding semidefinite programming relaxations obtained by the Sum-of-Squares method (Lasserre hierarchy). Our approach is based on using the connection between these relaxations and the Sum-of-Squares proof system to transform a combining algorithm---an algorithm that maps a distribution over solutions into a (possibly weaker) solution---into a rounding algorithm that maps a solution of the relaxation to a solution of the original problem.
H2A.Z acidic patch couples chromatin dynamics to regulation of gene expression programs during ESC differentiation.

The histone H2A variant H2A.Z is essential for embryonic development and for proper control of developmental gene expression programs in embryonic stem cells (ESCs). Divergent regions of amino acid sequence of H2A.Z likely determine its functional specialization compared to core histone H2A. For example, H2A.Z contains three divergent residues in the essential C-terminal acidic patch that reside on the surface of the histone octamer as an uninterrupted acidic patch domain; however, we know little about how these residues contribute to chromatin structure and function. Here, we show that the divergent amino acids Gly92, Asp97, and Ser98 in the H2A.Z C-terminal acidic patch (H2A.ZAP3) are critical for lineage commitment during ESC differentiation. H2A.Z is enriched at most H3K4me3 promoters in ESCs including poised, bivalent promoters that harbor both activating and repressive marks, H3K4me3 and H3K27me3 respectively. We found that while H2A.ZAP3 interacted with its deposition complex and displayed a highly similar distribution pattern compared to wild-type H2A.Z, its enrichment levels were reduced at target promoters. Further analysis revealed that H2A.ZAP3 was less tightly associated with chromatin, suggesting that the mutant is more dynamic. Notably, bivalent genes in H2A.ZAP3 ESCs displayed significant changes in expression compared to active genes. Moreover, bivalent genes in H2A.ZAP3 ESCs gained H3.3, a variant associated with higher nucleosome turnover, compared to wild-type H2A.Z. We next performed single cell imaging to measure H2A.Z dynamics. We found that H2A.ZAP3 displayed higher mobility in chromatin compared to wild-type H2A.Z by fluorescent recovery after photobleaching (FRAP). Moreover, ESCs treated with the transcriptional inhibitor flavopiridol resulted in a decrease in the H2A.ZAP3 mobile fraction and an increase in its occupancy at target genes indicating that the mutant can be properly incorporated into chromatin. Collectively, our work suggests that the divergent residues in the H2A.Z acidic patch comprise a unique domain that couples control of chromatin dynamics to the regulation of developmental gene expression patterns during lineage commitment.
The IIG iron meteorites: Probable formation in the IIAB core

Abstract The addition of two meteorites to the iron meteorite grouplet originally known as the Bellsbank trio brings the population to five, the minimum number for group status. With Ga and Ge contents in the general “II” range, the new group has been designated IIG. The members of this group have low-Ni contents in the metal and large amounts of coarse schreibersite ((Fe,NI)3P); their bulk P contents are 17–21 mg/g, the highest known in iron meteorites. Their S contents are exceptionally low, ranging from 0.2 to 2 mg/g. We report neutron-activation-analysis data for metal samples; the data generally show smooth trends on element-Au diagrams. The low Ir and high Au contents suggest formation during the late crystallization of a magma. Because on element-Au or element-Ni diagrams the IIG fields of the important taxonomic elements Ni, Ga, Ge and As are offset from those of the IIAB irons, past researchers have concluded that the IIG irons could not have formed from the same magma, and thus that the two groups originated on separate parent bodies. However, on most element-Au diagrams the IIG fields plot close to extensions of IIAB trends to higher Au concentrations. There is general agreement that immiscibility led to the formation of an upper S-rich and a lower P-rich magma in the IIAB core. We suggest that the IIG irons formed from the P-rich magma, and that schreibersite was a liquidus phase during the final stages of crystallization. The offsets in Ni and As (and possibly other elements) may result from solid-state elemental redistribution between metal and schreibersite during slow cooling. For example, it is well established that the equilibrium Ni content is >2× higher in late-formed relative to early-formed schreibersite. It is plausible that As substitutes nearly ideally for P in schreibersite at eutectic temperatures but becomes incompatible at low temperatures. [Wasson J. T., Huber, H. and Malvin, D. J. (2007) Formation of IIAB iron meteorites. Geochim. Cosmochim. Acta 71, 760–781] argued that, in the most evolved IIAB irons, the amount of trapped melt was high. The high P contents of IIG irons also require high contents of trapped melt but the local geometry seems to have allowed the S-rich immiscible melt to escape as it formed. The escaping melt may have selectively depleted elements such as Au and Ge.
Chemical synthesis of S-ribosyl-l-homocysteine and activity assay as a LuxS substrate

Bacterial quorum sensing is mediated by autoinducers, small signaling molecules generated by bacteria. It has been proposed that the LuxS enzyme converts S-ribosyl-L-homocysteine to 4,5-dihydroxy-2,3-pentanedione, the precursor of autoinducer 2 (AI-2). We report here a chemical synthesis of S-ribosyl-L-homocysteine and its analogue using Mitsunobu coupling. Chemically synthesized ribosylhomocysteine has been confirmed as a substrate for LuxS in both an enzyme assay and a whole cell quorum sensing assay. The chemical entities of products from the LuxS reaction were also established. Several ribosylhomocysteine analogues have been tested as LuxS inhibitors.
The Effect of Mere Touch on Perceived Ownership

This research finds that merely touching an object results in an increase in perceived ownership of that object. For nonowners, or buyers, perceived ownership can be increased with either mere touch or with imagery encouraging touch. Perceived ownership can also be increased through touch for legal owners, or sellers of an object. We also explore valuation of an object and conclude that it is jointly influenced by both perceived ownership and by the valence of the touch experience. We discuss the implications of this research for online and traditional retailers as well as for touch research and endowment effect research.
Glycerol conductance and physical asymmetry of the Escherichia coli glycerol facilitator GlpF.

The aquaglyceroporin GlpF is a transmembrane channel of Escherichia coli that facilitates the uptake of glycerol by the cell. Its high glycerol uptake rate is crucial for the cell to survive in very low glycerol concentrations. Although GlpF allows both influx and outflux of glycerol, its structure, similar to the structure of maltoporin, exhibits a significant degree of asymmetry. The potential of mean force characterizing glycerol in the channel shows a corresponding asymmetry with an attractive vestibule only at the periplasmic side. In this study, we analyze the potential of mean force, showing that a simplified six-step model captures the kinetics and yields a glycerol conduction rate that agrees well with observation. The vestibule improves the conduction rate by 40% and 75% at 10-μM and 10-mM periplasmic glycerol concentrations, respectively. In addition, neither the conduction rate nor the conduction probability for a single glycerol (efficiency) depends on the orientation of GlpF. GlpF appears to conduct equally well in both directions under physiological conditions.
Femtosecond Optical Spectroscopy and Scanning Probe Microscopy

Results from a new experimental technique for simultaneous spatial and temporal resolution studies of optically initiated dynamics at interfaces are presented.
Governance and enterprise restructuring: the case of Macedonia

This paper is a case study of the Republic of Macedonia (Southeast Europe), which focuses on examining governance and enterprise restructuring. Governance and enterprise restructuring is already defined indicator in EBRD’s studies and transition reports, measuring the effective corporate governance and corporate control exercised through domestic financial institutions and markets, fostering market-driven restructuring. As of the beginning of the transition process, governance and enterprise restructuring remains in the center, as essential pillar, that moves forward the society towards developed market economy. The data used in this article are analyzed with an econometric regression model, which as employed in this study examines the interrelationships between governance and enterprise restructuring and set of policies that influence the governance patterns.
Biodegradable artificial leukocyte for targeted drug delivery

Selectins are suitable biological molecules for target delivery of anti-inflammatory drugs due to their site-specific expression on endothelial cells during inflammation. A target drug delivery system using porous, biodegradable, poly-lactic-co-glycolic-acid (PLGA) microspheres coated with leukocyte functional ligand, Sialyl Lewis/sup x/, has been developed. We attached biotinylated-Sialyl-Lewis/sup x/ to avidin-linked PLGA microspheres via carbodiiamide chemistry, and our in vitro assays showed that they display rolling adhesion to selectin-coated surfaces under hydrodynamic flow. The rolling velocity of these artificial leukocytes is similar to that displayed by leukocytes rolling on P- or E-selectin coated surfaces. We can tune rolling velocity, and hence residence time of capsules on surfaces, by changing the density of Sialyl Lewis/sup x/ on the microsphere surfaces.
Nickel/Bis(oxazoline)-Catalyzed Asymmetric Kumada Reactions of Alkyl Electrophiles: Cross-Couplings of Racemic α-Bromoketones

The first asymmetric Kumada reactions of alkyl electrophiles are described, specifically, cross-couplings of racemic α-bromoketones with aryl Grignard reagents. Several features of this investigation are of interest. First, the couplings proceed at remarkably low temperature (−40 or −60 °C), which enables the asymmetric synthesis of racemization-prone α-arylketones. Second, dialkyl ketones undergo enantioselective coupling in good ee and yield. Third, readily available bis(oxazolines) are shown for the first time to be effective ligands for cross-couplings of alkyl electrophiles, thereby opening the door to new opportunities in asymmetric catalysis.
Safety verification of model helicopter controller using hybrid input/output automata

This paper presents an application of the Hybrid I/O Automaton (HIOA) framework [12] in verifying a realistic hybrid system. A supervisory pitch controller for a model helicopter system is designed and then verified. The design of the supervisor is limited by the actuator bandwidth, the sensor inaccuracies, and the sampling rates. Verification is carried out by induction over the length of an execution of the composed system automaton. The HIOA model makes the inductive proofs tractable by decomposing them into independent discrete and continuous parts. The paper also presents a set of language constructs for specifying hybrid I/O automata.
Immobilization effects on contractile properties of aging rat skeletal muscle

The effect of four weeks of ankle immobilization on muscle mass and in situ contractile properties of soleus (SOL), plantaris (PLA), and extensor digitorum longus (EDL) of 31- and 37-monthold (mo) Fisher 344/Brown Norway rats was examined. Following contractile tests, muscles were harvested, weighed, and analyzed for fiber type and fiber cross-sectional area. Body weights (g) were similar in both control (CON) groups (31 mo, 578±20; 37 mo, 553±26; mean±SE) and both immobilized (IM) groups (31 mo, 496±6; 37 mo, 461±15). Immobilization-related differences in peak tetanic tension (g) were less in 37 mo than 31 mo rats (age 3treatment, p <0.05) for SOL (31 mo, CON 156±11, IM 63±12; 37 mo, CON 70±6, IM 46±8), PLA (31 mo, CON 435±13, IM 239±40; 37 mo, CON 155±14, IM 152±20) and EDL (31 mo, CON 227±13, IM 139±17; 37 mo, CON 117±16, IM 108±4). Immobilization-related differences in muscle mass (mg) were smaller in 37 mo rats compared to 31 mo animals for SOL (31 mo, 206±14 vs 129±8, 37 mo, 148±5 vs 114±2, age 3 treatment p<0.06) and PLA (31 mo, 409±14 vs 257±22, 37 mo, 234±17 vs 181±18, age 3 treatment p<0.05), but immobilization-related muscle mass differences were similar in both age groups for EDL (31 mo, 178±7 vs 134±9; 37 mo, 157±10 vs 112±7). There were no immobilization-related changes in fiber type distribution in any of the three muscles studied in either age group. The results suggest that disuse-related change is diminished when superimposed on muscles that have already undergone marked age-related decline.
Transmission Eigenvalues and Thermoacoustic Tomography

The spectrum of the interior transmission problem is related to the unique determination of the acoustic properties of a body in thermoacoustic imaging. Under a non-trapping hypothesis, we show that sparsity of the interior transmission spectrum implies a range separation condition for the thermoacoustic operator. In odd dimensions greater than or equal to 3, we prove that the interior transmission spectrum for a pair of radially symmetric non-trapping sound speeds is countable, and conclude that the ranges of the associated thermoacoustic maps have only trivial intersection.
Autonomous Optical Navigation at Jupiter: A Linear Covariance Analysis

On 24 October 1998 NASA launched Deep Space 1, an experimental interplanetary spacecraft used to validate future technologies including an autonomous optical navigation system. Before Deep Space 1, interplanetary navigation was performed primarily through Earth-based measurements to provide accurate position and velocity estimates of the spacecraft. Improvements in imaging and computing technologies, enabling onboard processing and orbit determination, have lead to expanded interest in autonomous spacecraft. Development of autonomous optical navigation systems for interplanetary spacecraft requires extensive modeling and analysis to ensure success. This paper, using a linear covariance analysis, evaluates the efficacy of using optical angles-only measurements of the moons of Jupiter to determine a spacecraft’s position and velocity during a Jupiter approach. The analysis also evaluates the dominant error sources in the orbit determination calculations for preflight performance evaluations.
Low-Dose DDAVP in Nocturnal Enuresis

A five-year experience with the vasopressin analogue desmopressin acetate (DDAVP) for nocturnal enuresis is described in 59 children. The initial starting dose of 5 μg at bedtime is lower than that reported in other series. Eighty-one percent of patients required 10 μg or less to achieve improvement or resolution of bedwetting.
Discriminative linear transforms for feature normalization and speaker adaptation in HMM estimation

Linear transforms have been used extensively for training and adaptation of HMM-based ASR systems. Recently procedures have been developed for the estimation of linear transforms under the Maximum Mutual Information (MMI) criterion. In this paper we introduce discriminative training procedures that employ linear transforms for feature normalization and for speaker adaptive training. We integrate these discriminative linear transforms into MMI estimation of HMM parameters for improvement of large vocabulary conversational speech recognition systems.
Laboratory Experimental Testbeds: Application to the PCS Auction

The use of laboratory experimental methods in economics has been growing rapidly. With each application, new insights are gained about how the methodology can be used to supplement the more traditional forms of research. Such was the case with the development of the Federal Communications Commission (FCC) policy for the auction of licenses for Personal Communication Systems (PCS). At several different stages the laboratory experimental methods of economics were used. The application differed at each of these stages, representing the different types of relationships that can exist among theory, observation, and policy. This paper is a brief account of the applications.
Fragment multiplicity distributions, a signal of true nuclear multifragmentation

Multiplicity fluctuations of intermediate-mass fragments are studied with the percolation model. It is shown that super-Poissonian fluctuations occur near the percolation transition and that this behavior is associated with the fragmentative nature of the percolation model. The consequences of various choices in defining and binning fragments are also evaluated. Several suggestions for experiments in nuclear fragmentation are presented. q 1998 Published by Elsevier Science B.V. All rights reserved.
Rh(I)-catalyzed arylation of heterocycles via C-H bond activation: expanded scope through mechanistic insight.

A practical, functional group tolerant method for the Rh-catalyzed direct arylation of a variety of pharmaceutically important azoles with aryl bromides is described. Many of the successful azole and aryl bromide coupling partners are not compatible with methods for the direct arylation of heterocycles using Pd(0) or Cu(I) catalysts. The readily prepared, low molecular weight ligand, Z-1-tert-butyl-2,3,6,7-tetrahydrophosphepine, which coordinates to Rh in a bidentate P-olefin fashion to provide a highly active yet thermally stable arylation catalyst, is essential to the success of this method. By using the tetrafluoroborate salt of the corresponding phosphonium, the reactions can be assembled outside of a glove box without purification of reagents or solvent. The reactions are also conducted in THF or dioxane, which greatly simplifies product isolation relative to most other methods for direct arylation of azoles employing high-boiling amide solvents. The reactions are performed with heating in a microwave reactor to obtain excellent product yields in two hours.
Estimated Seasonal Cycle of North Atlantic Eighteen Degree Water Volume

The seasonal cycle in the volume and formation rate of Eighteen Degree Water (EDW) in the North Atlantic is quantified over the 3-yr period from 2004 to 2006. The EDW layer is defined as all waters that have a temperature between 178 and 198C. The study is facilitated by a synthesis of various observations— principally Argo profiles of temperature and salinity, sea surface temperature, and altimetry—using a general circulation model as an interpolation tool. The winter increase in EDW volume is most pronounced in February, peaking at about 8.6 Svy, where 1 Svy ’ 3.15 3 10 13 m 3 corresponding to a 1 Sv (Sv [ 10 6 m 3 s 21 ) flow sustained for one year. This largely reflects winter EDW formation due to air–sea heat fluxes. Over the remainder of the year, newly created EDW is consumed by air–sea heat fluxes and ocean mixing, which roughly contribute 2 / 3 and 1 / 3, respectively. The authors estimate a net annual volume increase of 1.4 Svy, averaged over the 3-yr period. It is small compared to the amplitude of the seasonal cycle (8.6 Svy) and annual formation due to air–sea fluxes (4.6 Svy). The overall EDW layer volume thus appears to fluctuate around a stable point during the study period. An estimate of the full EDW volume budget is provided along with an uncertainty estimate of 1.8 Svy, and largely resolves apparent conflicts between previous estimates.