cssi/SciSciGPT-SciSciNet huggingface dataset:
On optimality gaps in the Halfin–Whitt regime

We consider optimal control of a multi-class queue in the Halfin–Whitt regime, and revisit the notion of asymptotic optimality and the associated optimality gaps. The existing results in the literature for such systems provide asymptotically optimal controls with optimality gaps of $o(\sqrt{n})$ where n is the system size, for example, the number of servers. We construct a sequence of asymptotically optimal controls where the optimality gap grows logarithmically with the system size. Our analysis relies on a sequence of Brownian control problems, whose refined structure helps us achieve the improved optimality gaps.
Corporate Wellness Programs: Implementation Challenges in the Modern American Workplace

Being healthy is important for living well and achieving longevity. In the business realm, furthermore, employers want healthy employees, as these workers tend to be more productive, have fewer rates of absenteeism, and use less of their health insurance resources. This article provides an overview of corporate “wellness” efforts in the American workplace and the concomitant challenges which employers will confront in implementing these programs. Consequently, employers and managers must reflect upon wellness policies and objectives, consult with professionals, and discuss the ramifications thereof prior to implementation. The authors herein explore how employers are implementing policies that provide incentives to employees who lead “healthy” lifestyles as well as ones that impose costs on employees who lead “unhealthy” lifestyles. The distinctive contribution of this article is that it proactively explores wellness program implementation challenges and also supplies “best practices” in the modern workplace, so employers can be better prepared when they promulgate wellness policies, and then take practical steps to help their employees become healthier and thereby help to reduce insurance costs. The article, moreover, addresses how wellness policy incentives—in the form of “carrots” as well as penalties—in the form of “sticks” could affect employees, especially “non-healthy” employees, as well as employers, particularly legally. Based on the aforementioned challenges, the authors make practical recommendations for employers and managers, so that they can fashion and implement wellness policies that are deemed to be legal, ethical, and efficacious.
Individual Risk in an Investment-Based Social Security System

This paper examines the risk aspects of an investment-based defined contribution Social Security plan. We focus on the risk after the plan is fully phased in. Individuals deposit a fraction of wages to a Personal Retirement Account (PRA), invest these funds in a 60:40 equity-debt mix, and in a similarly invested annuity at age 67. The value of the assets follows a random walk with mean and variance of a 60:40 equity-debt portfolio over the period 1946-95, a mean log return of 5.5 percent (net of administrative costs of 0.4 percent) and a standard deviation of 12.5 percent. We study he stochastic distributions of this process by doing 10,000 simulations of the 80-year experience of the cohort that reached age 21 in 1998. The resulting annuities are compared to the future defined benefits specified in current law (the benchmark' benefits). With no uncertainty, a 5.5 percent log return would permit the benchmark benefits to be purchased with PRA deposits of 3.1 percent of payroll, only one-sixth of the pay-as-you-go tax needed for the benchmark benefits. Saving a higher share of wages provides a cushion' that protects the individual from the risk of an unacceptably low level of benefits. For example, PRA deposits of 6 percent of wages reduces the probability that the benefits are less than the benchmark to 0.17 and the probability that they are less than 61 percent of the benchmark to 0.05. PRA deposits of 9 percent of wages (half of the tax rate required in a pay-as-you-go system) would substantially reduce these risks. This pure investment-based plan is an extreme case. The investment risk can be reduced further by using a mixed system that combines pay-as-you-go and investment-based components or that makes intergenerational transfers conditional on the performance of stock and bond prices.
Assessing the effect of geographically correlated failures on interconnected power-communication networks

We study the reliability of power transmission networks under regional disasters. Initially, we quantify the effect of large-scale non-targeted disasters and their resulting cascade effects on power networks. We then model the dependence of data networks on the power systems and consider network reliability in this dependent network setting. Our novel approach provides a promising new direction for modeling and designing networks to lessen the effects of geographical disasters.
The SN 1006 Remnant: Optical Proper Motions, Deep Imaging, Distance, and Brightness at Maximum

We report the first measurement of proper motions in the SN 1006 remnant (G327.6+14.6) based entirely on digital images. CCD images from three epochs spanning a period of 11 yr are used: 1987 from Las Campanas and 1991 and 1998 from Cerro Tololo Inter-American Observatory. The filaments in SN 1006 are nonradiative, appearing only in the Balmer lines of hydrogen. Delicate filaments—probably thin sheets seen in projection—delineate the shock front along the northwestern rim of the remnant. We use the center of curvature of the filaments to define a convenient geometry and integrate along short segments to obtain one-dimensional profiles. These remain unchanged, within seeing and statistical errors, from one epoch to another. Measuring the shift in a direction perpendicular to the filaments, we obtain proper motions of 280 ± 8 mas yr-1 along the entire length where the filaments are well defined, with little systematic variation along the filaments. In addition to the measurements of the well-defined filaments in the northwest of SN 1006, we also report very deep Hα imaging observations of the entire remnant that clearly show very faint emission surrounding almost the entire shell, as well as some diffuse emission regions in the (projected) interior. Combining the proper-motion measurement with a recent measurement of the shock velocity based on spectra of the same filaments by Ghavamian et al. leads to a distance of 2.18 ± 0.08 kpc to SN 1006. Several lines of argument suggest that SN 1006 was a Type Ia event, so the improved distance measurement can be combined with the peak luminosity for SNe Ia, as recently determined for events in galaxies with Cepheid-based distances, to calculate the apparent brightness of the spectacular event that drew wide attention in the 11th century. The result, Vmax = -7.5 ± 0.4, lies squarely in the middle of the wide range of estimates based on the historical observations.
Noncommutative biorthogonal polynomials

We define and study biorthogonal sequences of polynomials over noncommutative rings, generalizing previous treatments of biorthogonal polynomials over commutative rings and of orthogonal polynomials over noncommutative rings. We extend known recurrence relations for specific cases of biorthogonal polynomials and prove a general version of Favard@?s theorem.
Gold(I)-catalyzed Claisen rearrangement of allenyl vinyl ethers; synthesis of substituted 1,3-dienes.

Synthesis of substituted 1,3-dienes was achieved viagold(I)-catalyzed Claisen rearrangement of allenyl vinyl ethers. The N-heterocyclic carbenegold chloride catalyst (IPrAuCl) was superior in terms of activity and selectivity and afforded the 3,3-product in excellent yields. A proposed cation-π inter-action played a significant role in affecting the reaction rate.
Efficient visual grasping alignment for cylinders

Monocular information from a gripper-mounted camera is used to servo the robot gripper to grasp a cylinder. The fundamental concept for rapid pose estimation is to reduce the amount of information that needs to be processed during each vision update interval. The grasping procedure is divided into four phases: learn, recognition, alignment, and approach. In the learn phase, a cylinder is placed in the gripper and the pose estimate is stored and later used as the servo target. This is performed once as a calibration step. The recognition phase verifies the presence of a cylinder in the camera field of view. An initial pose estimate is computed and uncluttered scan regions are selected. The radius of the cylinder is estimated by moving the robot a fixed distance toward the cylinder and observing the change in the image. The alignment phase processes only the scan regions obtained previously. Rapid pose estimates are used to align the robot with the cylinder at a fixed distance from it. The relative motion of the cylinder is used to generate an extrapolated pose-based trajectory for the robot controller. The approach phase guides the robot gripper to a grasping position. The cylinder can be grasped with a minimal reaction force and torque when only rough global pose information is initially available.
Hardening of cement based paint

Abstract A cement-based paint coating was hardened in air of different relative humidities at room temperature. The best properties were obtained when complete carbonation took place at high relative humidities and long hardening times.
Downscaling near-surface wind over complex terrain using a physically-based statistical modeling approach

A physically-based statistical modeling approach to downscale coarse resolution reanalysis near-surface winds over a region of complex terrain is developed and tested in this study. Our approach is guided by physical variables and meteorological relationships that are important for determining near-surface wind flow. Preliminary fine scale winds are estimated by correcting the course-to-fine grid resolution mismatch in roughness length. Guided by the physics shaping near-surface winds, we then formulate a multivariable linear regression model which uses near-surface micrometeorological variables and the preliminary estimates as predictors to calculate the final wind products. The coarse-to-fine grid resolution ratio is approximately 10–1 for our study region of southern California. A validated 3-km resolution dynamically-downscaled wind dataset is used to train and validate our method. Winds from our statistical modeling approach accurately reproduce the dynamically-downscaled near-surface wind field with wind speed magnitude and wind direction errors of <1.5 ms−1 and 30°, respectively. This approach can greatly accelerate the production of near-surface wind fields that are much more accurate than reanalysis data, while limiting the amount of computational and time intensive dynamical downscaling. Future studies will evaluate the ability of this approach to downscale other reanalysis data and climate model outputs with varying coarse-to-fine grid resolutions and domains of interest.
The internationalization process model through the lens of the global color picture tube industry

Abstract Internationalization theories from economics and international business disciplines suggest that products are launched, and production facilities established, sequentially in industrialized, newly industrialized, and finally, in developing countries. From a firm level perspective, operations management researchers have proposed descriptive models of generic roles of international factories. But little has appeared in the economics, international business, or operations management literature that compares these two views or provides much empirical evidence to support divergent claims. In this paper, we compare both perspectives and shed insight into factory roles through a detailed examination of data on plant practices and performance in the global picture tube industry. Our analysis suggests that existing theory and descriptive models do not possess enough explanatory power to adequately predict or describe the dynamics of product and production loci today. We highlight the need for a new theory by contrasting today's global business realities with those of yesteryears.
Patterns of Permeability in Eolian Deposits: Page Sandstone (Jurassic), Northeastern Arizona

Les 2000 mesures realisees a l'aide d'un minipermeametre sur un affleurement du gres Page mettent en evidence trois modes distincts de permeabilite reliables a trois types de stratification
Fast parallel algorithms for short-range molecular dynamics

Abstract Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.
Electron and hydrogen transfer reactions of nucleotides: from Stern-Volmer quenching to nucleoprotein structure

Abstract The complex Pt2(pop)44− abstracts hydrogen atoms and electrons from DNA upon photolysis into the d σ ∗ → p σ excited state (pop = P2O5H22−). In duplex DNA, the hydrogen atoms are abstracted from the 4′- and 5′- positions of the deoxynbose functionality, and electrons are abstracted by tunneling from the guanine nucleobase. At high Mg2+ concentrations, the Pt2(pop)44− tetraanion can associate more intimately with the duplex, and both hydrogen atom and electron transfer are efficient; however, at low Mg2+ concentrations, the complex is situated far from the duplex so that the only efficient pathway is electron tunneling. Therefore, the guanine/sugar ratio decreases with increasing Mg2+. The electron transfer pathway can also be examined in the absence of the hydrogen transfer pathway in thermal reactions where the electron is abstracted from guanine by Ru(bpy)33+ (bpy = 2,2′-bipyridine). These reactions can be initiated electrochemically by potentiation of the complex to the 3 + form, which produces catalytic enhancements in cyclic voltammograms. These enhancements show that guanine multiplets are more reactive than dispersed guanines. Finally, binding of DNA to the HhaI methyltransferase causes flipping of a cytosine into the active site of the enzyme, leaving behind an unpaired guanine residue that is more reactive towards electron transfer than the paired guanine, an effect visible in high-resolution electrophoresis gels after photolysis in the presence of Pt2(pop)44−.
Effects of KOH concentration on the shape change and cycle life of Zn/NiOOH cells

This study describes the results of 23 Ah Ni/Zn cells with zinc electrodes containing and nonsintered nickel oxide electrodes. Calcium hydroxide containing zinc electrodes tested in show less shape change and zinc dendrites, are less soluble in , and have a higher capacity retention and cycle life than comparable zinc electrodes in cells with higher concentrations. This improvement in performance is attributed to the formation of calcium zincate in the electrode structure. Formation of calcium zincate is shown to be concentration dependent.
Dynamic input/output automata, a formal model for dynamic systems

We present a mathematical state-machine model, the Dynamic I/O Automaton (DIOA) model, for defining and analyzing dynamic systems of interacting components. The systems we consider are dynamic in two senses: (1) components can be created and destroyed as computation proceeds, and (2) the set of events in which a component may participate can change as computation proceeds. The new model admits a notion of external system behavior, based on sets of traces. It also features a parallel composition operator for dynamic systems, which satisfies standard execution projection and pasting results, and a notion of simulation from one dynamic system to another, which can be used to prove that one system implements the other.
Planar ion trap geometry for microfabrication

We describe a novel high aspect ratio radiofrequency linear ion trap geometry that is amenable to modern microfabrication techniques. The ion trap electrode structure consists of a pair of stacked conducting cantilevers resulting in confining fields that take the form of fringe fields from parallel plate capacitors. The confining potentials are modeled both analytically and numerically. This ion trap geometry may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers.
Facile preparation of pyrylium and pyridinium bromides under neutral conditions

Abstract Pyrylium and pyridinium bromides may be prepared in virtually quantitative yield by reaction of the corresponding base with an excess of tert -butyl bromide under reflux in chloroform solution.
X-Ray and Optical Flux Anomalies in the Quadruply Lensed QSO 1RXS J1131?1231

Optical and X-ray observations of the quadruply imaged quasar 1RXS J1131-1231 show flux ratio anomalies among the images of factors of ~2 in the optical and ~3-9 in X-rays. Temporal variability of the quasar seems an unlikely explanation for the discrepancies between the X-ray and optical flux ratio anomalies. The negative parity of the most affected image and the decreasing trend of the anomalies with wavelength suggest microlensing as a possible explanation; this would imply that the source of optical radiation in RXS J1131 is ~104Rg in size for a black hole mass of ~108 M?. We also present evidence for different X-ray spectral hardness ratios among the four images.
Detection of at-risk pregnancy by means of highly sensitive assays for thyroid autoantibodies

We screened 552 women who presented to their obstetrician in the first trimester of pregnancy using highly sensitive enzyme-linked immunosorbent assays for the presence of thyroglobulin and thyroid peroxidase autoantibodies and found an incidence of positivity of 19.6%. The tendency to secrete detectable levels of thyroid autoantibodies was significantly correlated with an increased rate of miscarriage. Thyroid autoantibody-positive women miscarried at a rate of 17%, compared with 8.4% for the autoantibody-negative women. Individual levels of thyroglobulin and thyroid peroxidase autoantibodies were similarly related to this increased miscarriage rate, with no evidence of autoantibody specificity in the relationship. Furthermore, the increase in miscarriages could not be explained by differences in thyroid hormone levels, the presence of cardiolipin autoantibodies, maternal age, gestational age at the time of maternal entry into the study, or previous obstetric history. We conclude that thyroid autoantibodies are an independent marker of "at-risk" pregnancy.
Synchrony with Shunting Inhibition

J Crayton Pruitt Department of Biomedical Engineering,University of Florida, Gainesville, FL 32611(Dated: January 30, 2009)Spike time response curves (STRC’s) are used to study the inﬂuence of synaptic stimuli on theﬁring times of a neuron oscillator without the assumption of weak coupling. They allow us toapproximate the dynamics of synchronous state in networks of neurons through a discrete map,which can then be used to predict the stability of patterns of synchrony in the network. Generaltheory for taking into account the contribution from higher order STRC terms, resulting fromperturbations caused by synaptic stimuli lasting for more than one ﬁring cycle of a neuron, in theapproximation of the discrete map is still lacking. Here we present a general theory to account forhigher order STRC corrections in the approximation of discrete map to determine the domain of 1:1phase locked state in a network of two interacting neurons. We test the ability of this discrete mapto predict the domain of 1:1 phase locked state in a network of two neurons interacting through ashunting synapse.
RG flows in d dimensions, the dilaton effective action, and the a-theorem

Motivated by the recent dilaton-based proof of the 4d a-theorem, we study the dilaton effective action for RG flows in d dimensions. When d is even, the action consists of a Wess-Zumino (WZ) term, whose Weyl-variation encodes the trace-anomaly, plus all Weyl-invariants. For d odd, the action consists of Weyl-invariants only. We present explicit results for the flat-space limit of the dilaton effective action in d-dimensions up to and including 8-derivative terms. GJMS-operators from conformal geometry motivate a form of the action that unifies the Weyl-invariants and anomaly-terms into a compact general-d structure. A new feature in 8d is the presence of an 8-derivative Weyl-invariant that pollutes the O(p 8)-contribution from the WZ action to the dilaton scattering amplitudes; this may challenge a dilaton-based proof of an a-theorem in 8d. We use the example of a free massive scalar for two purposes: 1) it allows us to confirm the structure of the d-dimensional dilaton effective action explicitly; we carry out this check for d = 3, 4, 5, . . . , 10; and 2) in 8d we demonstrate how the flow Δa = a UV − a IR can be extracted systematically from the O(p 8)-amplitudes despite the contamination from the 8-derivative Weyl-invariant. This computation gives a value for the a-anomaly of the 8d free conformal scalar that is shown to match the value obtained from zeta-function regularization of the log-term in the free energy.
Learning from natural instructions

Machine learning is traditionally formalized and investigated as the study of learning concepts and decision functions from labeled examples, requiring a representation that encodes information about the domain of the decision function to be learned. We are interested in providing a way for a human teacher to interact with an automated learner using natural instructions, thus allowing the teacher to communicate the relevant domain expertise to the learner without necessarily knowing anything about the internal representations used in the learning process. In this paper we suggest to view the process of learning a decision function as a natural language lesson interpretation problem, as opposed to learning from labeled examples. This view of machine learning is motivated by human learning processes, in which the learner is given a lesson describing the target concept directly and a few instances exemplifying it. We introduce a learning algorithm for the lesson interpretation problem that receives feedback from its performance on the final task, while learning jointly (1) how to interpret the lesson and (2) how to use this interpretation to do well on the final task. traditional machine learning by focusing on supplying the learner only with information that can be provided by a task expert. We evaluate our approach by applying it to the rules of the solitaire card game. We show that our learning approach can eventually use natural language instructions to learn the target concept and play the game legally. Furthermore, we show that the learned semantic interpreter also generalizes to previously unseen instructions.
Suppressing curvature fluctuations in dynamical triangulations

Abstract We study numerically the dynamical triangulation formulation of two-dimensional quantum gravity using a restricted class of triangulation, so-called minimal triangulations, in which only vertices of coordination number 5, 6 and 7 are allowed [1]. A real-space RG analysis shows that for pure gravity (central charge c = 0) this restriction does not affect the critical behavior of the model. Furthermore, we show that the critical behavior of an Ising model coupled to minimal dynamical triangulations ( c = 1 2 ) is still governed by the KPZ-exponents.
Small carborane ligands as spectators and as players

Abstract A quarter-century of development of the chemistry of small metallacarboranes—metal sandwich complexes of ligands incorporating planar C 2 B 3 or pyramidal C 2 B 4 clusters—has seen many surprises, including the synthesis and isolation of the first thermally and oxidatively stable triple-decker (and larger) sandwiches, the discovery of metal-promoted oxidative fusion of carborane ligands, and a broad and rich array of structurally novel cluster and sandwich compounds that involve most of the transition elements and main group metals. In many of these species the metal-bound carborane unit formally replaces Cp or Cp*, and functions as a ‘spectator’ ligand, influencing the reactions of the metal center through electronic interaction. In other situations, some of which have been revealed only recently, the carborane ligand is directly involved in reactions with attacking substrates and undergoes permanent change in structure and/or composition. In this mode, the carborane as a ligand displays very different chemical behavior from that of its aromatic hydrocarbon counterparts and can lead to reactions and products that have no analogies in metallocene-based chemistry. Both roles are not only of interest from a pure chemistry viewpoint, but also have potential application as tools in directed synthesis. The chemistry described in this short review represents but one aspect of the development of organometallic-boron cluster chemistry in many laboratories, an area whose significance is growing as the new millennium approaches.
Laminar Boundary - Layer Wedge Flows with Evaporation and Combustion

Abstract A steady, laminar, boundary-layer flow of an oxidizer over a two-dimensional wedge (covered with fuel) involving evaporation (or sublimation) and combustion is studied for the case where chemical reaction is assumed to occur in an infinitesimally thin flame. Results presented include the effects of the Prandtl number, wedge parameter, and heat ratio on the profiles of the velocity, temperature, and composition in the boundary layer, the boundary-layer and displacement thickness, the flame position, the skin friction, and the rates of evaporation and combustion. Also included is a comparison of the boundary-layer characteristics with and without combustion. Because of the large density variation inside the boundary-layer as a result of combustion, the effect of pressure gradient is rather big. For a favorable pressure gradient, the velocity near the flame region is found to exceed the local freestream velocity. This velocity overshoot accounts for an increase in the skin friction for large favorable pressure gradients, in spite of the blowing effect due to evaporation. For an adverse pressure gradient, the effects of both mass addition and low density near the flame are to reduce the skin friction, thus causing separation to occur at an extremely small adverse pressure gradient.
Gender Equality Oversimplified: Using CEDAW to Counter the Measurement Obsession

Global measurements have become foundational for understanding gender equality as well as for directing resources and policy development to address gendered inequalities. We argue in this article that attempts to quantify gender (in)equality globally have limited potential for successfully challenging gender hierarchies if compared to internationally agreed upon women’s rights standards. To make this argument, we start by contrasting the general assumptions underlying the measurement approach with feminist scholarship on gender equality. Second, we examine nine key measures of global gender equality—the majority of which are produced by influential international organizations—and show that their focus on “countability” perpetuates a narrow and misleading understanding of gender (in)equality. Third, we present the CEDAW Convention and associated review process as an alternative to the measurement approach. The comparison highlights the need for evaluative tools that attend to the complexity and fluidity of gender norms and focus on context-specific agency to confront gender hierarchies.
Synthesis and evaluation of geldanamycin-estradiol hybrids

Geldanamycin (GDM) binds to the Hsp90 chaperone protein and causes the degradation of several important signalling proteins. A series of novel estradiol-geldanamycin hybrids has been synthesized and evaluated for their ability to induce the selective degradation of the estrogen receptor (ER). The hybrid compounds are active and more selective than the parent causing degradation of ER and HER2, but not other GDM targets.
An RF Technique for Plasma Number Density Measurement

It is well-known that a cylindrical plasma column in a transverse rf electric field is subject to a dipole resonance. The frequency at which this occurs can be used to determine the average electron density across the plasma section. This paper describes the experimental application of the technique to plasmas with and without a confining axial static magnetic field, and gives theoretical curves to assist in rapid reduction of the data. Higher order multipole resonances can also be excited. The feasibility of applying these to determination of the number density profile is discussed.
Dynamics and Control of Shock Motion in a Near-Isentropic Inlet

Inlet pressure recovery of supersonic aircraft could be improved using a near-isentropic inlet with only a weak normal shock aft of the throat; however, such an inlet is highly susceptible to unstart. Small perturbations can move the shock ahead of the throat, where it is unstable. The dynamics of the inlet and shock are analyzed using a low-order model that captures both the nonlinear shock motion and inlet acoustic propagation. This model allows parametric exploration of both the potential and limitations of using control to stabilize actively the shock, including actuator authority as a function of location, actuator authority, and bandwidth requirements, and sensor requirements. A simple control law is shown to be sufficient to stabilize the shock motion.
THEORY OF SUPERCONDUCTOR‐INSULATOR TRANSITIONS IN DISORDERED FILMS

A scaling theory for the zero temperature (T=0) superconductor to insulator transition in disordered films is described. Right at the transition, the system is predicted to be ‘‘metallic,’’ with a resistance per square having a finite, non‐zero value at T=0. This value, moreover, should be universal, independent of all microscpic details. In the presence of an applied magnetic field, an additional T=0 superconductor‐insulator transition is accessible at which both resistivities ρ xx and ρ xy should be universal.
An Assessment of the Rotation Rates of the Host Stars of Extrasolar Planets

The rotation periods of the host stars of extrasolar planets have been assessed against those of the Mount Wilson stars, open cluster stars, and evolutionary stellar models that include rotation. They appear to be normal, modulo certain inconsistencies in various necessary inputs. Selection of candidate planet hosts for radial velocity surveys by low rotation or activity has resulted in a planet host sample skewed toward older stars. Thus, cross-comparisons must be age-dependent. However, self-consistent ages are difficult to obtain, and activity ages show signs of systematic errors. There are indications that activity ages ought to be increased for subsolar mass stars and decreased for supersolar mass stars. Age uncertainties and a scarcity of measured rotation periods for planet host stars inflate the dispersion in older stars relative to those in open clusters. The presently available rotational models display inadequacies, most notably in producing fast enough early-type stars. The fact that only one planet host star, τ Boo, strongly suggests tidal spin-up, while on the order of 10 systems suggest orbital circularization is explicable in terms of the differing timescales for these two phenomena. The rotational normalcy of the planet host stars and other considerations suggest that they are not especially different from other main-sequence stars and that circumstellar matter and/or planets are probably ubiquitous, at least among sufficiently metal-rich solar-type stars.
Enantioselective nitroaldol reaction of α-ketoesters catalyzed by cinchona alkaloids

The development of highly enantioselective and general catalytic nitroaldol (Henry) reactions with ketones is a challenging yet desirable task in organic synthesis. In this communication, we report an asymmetric nitroaldol reaction with α-ketoesters catalyzed by a new C6‘−OH cinchona alkaloid catalyst. This is the first highly efficient organocatalytic asymmetric Henry reaction with ketones. This reaction is operationally simple and affords high enantioselectivity as well as good to excellent yield for a broad range of α-ketoesters.
Antithrombotic Therapy for Venous Thromboembolism

This article reviews the actions of various antithrombotic agents that are useful for the treatment of established venous thromboembolic disease. Heparin and coumarin are detailed.
Recent progress using chiral formamidines in asymmetric syntheses

Abstract The ability to generate a carbanion next to nitrogen in a chiral environment has led to a number of useful asymmetric routes to alkaloids and related substances. Mechanistic studies have been conducted to understand the nature of these alkylations.
Feedbacks of Terrestrial Ecosystems to Climate Change

Most modeling studies on terrestrial feedbacks to warming over the twenty-first century imply that the net feedbacks are negative—that changes in ecosystems, on the whole, resist warming, largely through ecosystem carbon storage. Although it is clear that potentially important mechanisms can lead to carbon storage, a number of less well-understood mechanisms, several of which are rarely or incompletely modeled, tend to diminish the negative feedbacks or lead to positive feedbacks. At high latitudes, negative feedbacks from forest expansion are likely to be largely or completely compensated by positive feedbacks from decreased albedo, increased carbon emissions from thawed permafrost, and increased wildfire. At low latitudes, negative feedbacks to warming will be decreased or eliminated, largely through direct human impacts. With modest warming, net feedbacks of terrestrial ecosystems to warming are likely to be negative in the tropics and positive at high latitudes. Larger amounts of warming will generall...
Synthesis and Structure of Two New Strontium Germanium Nitrides: Sr3Ge2N2 and Sr2GeN2

We report the structures of two new strontium germanium nitrides synthesized as crystals from the elements in sealed Nb tubes at 750 °C using liquid Na as a growth medium. Sr3Ge2N2 is isostructural with the previously reported Ba analogue. It crystallizes in P21/m (No. 11), with a = 9.032(2) A, b = 3.883(1) A, c = 9.648(2) A and β = 112.42(3)°, and has two formula units per unit cell. It contains GeN24- units and additionally |Ge2- zigzag chains. Sr2GeN2 crystallizes in P42/mbc (No. 135) with a = b = 11.773(2) A and c = 5.409(1) A and has Z = 8. It also contains GeN24- units which have 18 valence electrons and, consequently are bent, like the isoelectronic molecule SO2.
Frustration and melting of colloidal molecular crystals

Using numerical simulations we show that a variety of novel colloidal crystalline states and multi-step melting phenomena occur on square and triangular two-dimensional periodic substrates. At half-integer fillings different kinds of frustration effects can be realized. A two-step melting transition can occur in which individual colloidal molecules initially rotate, destroying the overall orientational order, followed by the onset of interwell colloidal hopping, in good agreement with recent experiments.
Cyclical patterns of employment, utilization, and profitability

The interaction between income distribution, accumulation, employment, and the utilization of capital is central to macroeconomic models in the "heterodox" tradition. This article examines the stylized pattern of these variables using U.S. data for the period after 1948. We look at the trends and cycles in individual time series and examine the bivariate cyclical patterns among the variables.
Validity of Psychological Assessment: Validation of Inferences from Persons' Responses and Performances as Scientific Inquiry into Score Meaning.

The traditional conception of validity divides it into three separate and substitutable types—namely, content, criterion, and construct validities. This view is fragmented and incomplete, especially because it fails to take into account both evidence of the value implications of score meaning as a basis for action and the social consequences of score use. The new unified concept of validity interrelates these issues as fundamental aspects of a more comprehensive theory of construct validity that addresses both score meaning and social values in test interpretation and test use. That is, unified validity integrates considerations of content, criteria, and consequences into a construct framework for the empirical testing of rational hypotheses about score meaning and theoretically relevant relationships, including those of an applied and a scientific nature. Six distinguishable aspects of construct validity are highlighted as a means of addressing central issues implicit in the notion of validity as a unified concept. These are content, substantive, structural, generalizability, external, and consequential aspects of construct validity. In effect, these six aspects function as general validity criteria or standards for all educational and psychological measurement, including performance assessments, which are discussed in some detail because of their increasing emphasis in educational and employment settings.
From social determinants to reducing health inequalities.

Pekka Puska is the Director General of the new Finnish National Institute for Health and Welfare (THL) that started in January 2009 after a merger of the National Public Health Institute (KTL) and the National Research and Development Centre for Welfare and Health (Stakes). He has been previously working for WHO in Geneva as Director for Non-communicable Disease Prevention and Health Promotion. He is currently the President of the World Heart Federation and the Vice President of the International Association of National Public Health Institutes.
A Unique Catalyst Effects the Rapid Room-Temperature Cross-Coupling of Organozinc Reagents with Carboxylic Acid Fluorides, Chlorides, Anhydrides, and Thioesters

We have identified a catalyst capable of effecting the rapid, room-temperature cross-coupling between acid fluorides and diorganozinc reagents. The use of acid fluorides as electrophilic partners allows this reaction to tolerate epimerizable functionality as well as β leaving groups. The same catalyst is also capable of cross-coupling acid chlorides, acyl cyanides, anhydrides, thioesters, and pyridyl esters. Noteworthy is the ability of the reaction to successfully transfer both groups from the organometalic fragment.
Lexicographic shellability of partial involutions

Abstract In this manuscript we study inclusion posets of Borel orbit closures on (symmetric) matrices. In particular, we show that the Bruhat poset of partial involutions is a lexicographically shellable poset. We determine which subintervals of the Bruhat posets are Eulerian, and moreover, by studying certain embeddings of the symmetric groups and their involutions into rook matrices and partial involutions, respectively, we obtain new shelling orders on the corresponding order complexes.
Solid-phase combinatorial chemistry and novel tagging methods for identifying leads

Encoded combinatorial chemical synthesis on solid phase is a new paradigm in organic chemistry that provides chemists with powers similar to those enjoyed by molecular biologists. Encoded chemical libraries will have a profound impact on all endeavors that seek to identify molecules with optimized properties and to understand the factors governing molecular interactions. In particular, the discovery and optimization of new therapeutic and diagnostic drug molecules, traditionally a slow manual process, will be greatly accelerated by this technology.
Black hole greybody factors and absorption of scalars by effective strings

Abstract We compute the greybody factors for classical black holes in a domain where two kinds of charges and their anticharges are excited by the extra energy over extremality. We compare the result to the greybody factors expected from an effective string mode] which was earlier shown to give the correct entropy. In the regime where the left- and right-moving temperatures are much smaller than the square root of the effective string tension, we find a non-trivial greybody factor which agrees with the effective string mode]. However, if the temperatures are comparable with the square root of the effective string tension, the greybody factors agree only at the leading order in energy. Nevertheless, there are several interesting relations between the two results, suggesting that a modification of the effective string mode] might lead to better agreement.
Materials discovery by crystal growth: Lanthanide metal containing oxides of the platinum group metals (Ru, Os, Ir, Rh, Pd, Pt) from molten alkali metal hydroxides

This review addresses the process of materials discovery via crystal growth, specifically of lanthanide metal containing oxides of the platinum group metals (Ru, Os, Ir, Rh, Pd, Pt). It provides a detailed overview of the use of hydroxide fluxes for crystal growth. The melt chemistry of hydroxide fluxes, specifically, the extensive acid base chemistry, the metal cation solubility, and the ability of hydroxide melts to oxidize metals are described. Furthermore, a general methodology for the successful crystal growth of oxides is provided, including a discussion of experimental considerations, suitable reaction vessels, reaction profiles and temperature ranges. Finally, a compilation of complex platinum group metal oxides recently synthesized using hydroxide melts, focusing on their crystal growth and crystal structures, is included.
Is There a Detectable Vishniac Effect

The dominant linear contribution to cosmic microwave background (CMB) fluctuations at small angular scales (1') is a second-order contribution known as the Vishniac or Ostriker-Vishniac effect. This effect is caused by the scattering of CMB photons off free electrons after the universe has been reionized, and is dominated by linear perturbations near the RV = 2 Mpc/(hΓ/0.2) scale in the cold dark matter cosmogony. As the reionization of the universe requires that nonlinear objects exist on some scale, however, one can compare the scale responsible for reionization to RV and ask whether a linear treatment is even feasible in different scenarios of reionization. For an Ω0 = 1 cosmology normalized to cluster abundances, only ~65% of the linear integral is valid if reionization is due to quasars in halos of mass ~109 M☉, while ~75% of the integral is valid if reionization was caused by stars in halos of ~106 M☉. In Λ or open cosmologies, both the redshift of reionization and zV are pushed farther back, but still only ~75% to ~85% of the linear integral is valid, independent of the ionization scenario. We point out that all odd higher order moments from Vishniac fluctuations are zero, while even moments are nonzero, regardless of the Gaussianity of the density perturbations. This provides a defining characteristic of the Vishniac effect that differentiates it from other secondary perturbations and may be helpful in separating them.
Linear systems on a special rational surface

We study the Hilbert series of a family of ideals J_\phi generated by powers of linear forms in k[x_1,...,x_n]. Using the results of Emsalem-Iarrobino, we formulate this as a question about fatpoints in P^{n-1}. In the three variable case this is equivalent to studying the dimension of a linear system on a blow up of P^2. The ideals that arise have the points in very special position, but because there are only seven points, we can apply results of Harbourne to obtain the classes of the negative curves. Reducing to an effective, nef divisor and using Riemann-Roch yields a formula for the Hilbert series. This proves the n=3 case of a conjecture of Postnikov and Shapiro, which they later showed true for all n. Postnikov and Shapiro observe that for a family of ideals closely related to J_\phi a similar result often seems to hold, although counterexamples exist for n=4 and n=5. Our methods allow us to prove that for n=3 an analogous formula is indeed true. We close with a counterexample to a conjecture Postnikov and Shapiro make about the minimal free resolution of these ideals.
Pseudorandom generators and the frequency of simplicity

Allender [2] showed that if there are dense P languages containing only a finite set of Kolmogorov-simple strings, then all pseudorandom generators are insecure. We extend this by proving that if there are dense P (or even BPP) languages containing only a sparse set of Kolmogorov-simple strings, then all pseudorandom generators are insecure.
Ubiquitous and temporal glycosylation of nuclear and cytoplasmic proteins

Gerzrldk& K C I I I W ~ ~ 11. Greis, I,.-Y. Dermis I h g , Melissa A. Bloinherg Teh-Yirig Chou, MatiSliiow Jiatg Llizaheth I? I ~ ~ I ~ I I I ~ ~ c , loris M. Snow, Lisa K. Kreppel, Itoberl C. Cole atid Bradley K. Hayes. Dept. Biocheni. & Molecular Genetics, University of Alabama at Birmingham, UAB Station, 1918 University Avenue, Birmingham, AL 35294-0005;Phone: (205) 934-4753; FAX: (205) 975-6685; Internet: GWHART@BMG.BHS.UAB.EDU.
The impact of safety organizing, trusted leadership, and care pathways on reported medication errors in hospital nursing units.

CONTEXT Prior research has found that safety organizing behaviors of registered nurses (RNs) positively impact patient safety. However, little research exists on the joint benefits of safety organizing and other contextual factors that help foster safety. OBJECTIVES Although we know that organizational practices often have more powerful effects when combined with other mutually reinforcing practices, little research exists on the joint benefits of safety organizing and other contextual factors believed to foster safety. Specifically, we examined the benefits of bundling safety organizing with leadership (trust in manager) and design (use of care pathways) factors on reported medication errors. SUBJECTS A total of 1033 RNs and 78 nurse managers in 78 emergency, internal medicine, intensive care, and surgery nursing units in 10 acute-care hospitals in Indiana, Iowa, Maryland, Michigan, and Ohio who completed questionnaires between December 2003 and June 2004. RESEARCH DESIGN Cross-sectional analysis of medication errors reported to the hospital incident reporting system for the 6 months after the administration of the survey linked to survey data on safety organizing, trust in manager, use of care pathways, and RN characteristics and staffing. RESULTS Multilevel Poisson regression analyses indicated that the benefits of safety organizing on reported medication errors were amplified when paired with high levels of trust in manager or the use of care pathways. CONCLUSIONS Safety organizing plays a key role in improving patient safety on hospital nursing units especially when bundled with other organizational components of a safety supportive system.