cssi/SciSciGPT-SciSciNet huggingface dataset:
Diastereoselective Alkylations of Oxazolidinone Glycolates: A Useful Extension of the Evans Asymmetric Alkylation

[reaction: see text] The diastereoselective alkylation of glycolate oxazolidinones has been demonstrated as a method for the enantioselective preparation of alpha-alkoxy carboxylic acid derivatives and selectively protected 1,2-diols. Various protecting groups on the glycolate hydroxyl and multiple substitution patterns on allylic iodides are tolerated in the alkylation. Yields for the alkylations are typically 70-85% with diastereoselectivities of >98:2.
Tunable optical gain and amplified spontaneous emission using type I and type II nanocrystal heterostructures

We study the effect of type I vs. type II carrier localization on optical gain properties of multishell nanocrystal heterostructures. Our results indicate that type-II structures provide improved gain performance in the green-blue spectral range
Modulation of limb dynamics in the swing phase of locomotion

Abstract A method was presented for quantifying cat (Felis catus) hind limb dynamics during swing phase of locomotion using a two-link rigid body model of leg and paw, which highlighted the dynamic interactions between segments. Comprehensive determination was made of cat segment parameters necessary for dynamic analysis, and regression equations were formulted to predict the inertial parameters of any comparable cat. Modulations in muscle and non-muscle components of knee and ankle joint moments were examined at two treadmill speeds using three gaits: (a) pace-like walk and trot-like walk, at 1.0 m s−1, and (b) gallop, at 2.1 m s−1. Results showed that muscle and segment interactive moments significantly effected limb trajectories during swing. Some moment components were greater in galloping than in walking, but net joint maxima were not significantly different between speeds. Moment magnitudes typically were greater for pace-like walking than for trot-like walking at the same speed. Generally, across gaits, the net and muscle moments were in phase with the direction of distal joint motion, and these same moments were out of phase with proximal joint motion. Intersegmental dynamics were not modulated exclusively by speed of locomotion, but interactive moments were also influenced significantly by gait mode.
Neutron profile refinement of the structure of FeOCl and FeOCl(TTF)1/8.5

Neutron diffraction studies on powder samples of FeOCl and FeOCl(TTF)/sub 1/8.5/ establish that TTF intercalated into FeOCl contributes to the diffraction pattern and exhibits long-range order. Room-temperature time-of-flight diffraction results are reported. The structure of FeOCl was refined in a space group Pmnm with a = 3.7730 (1) A, b = 7.9096 (1) A, and c = 3.3010 (1) A. Least-squares Rietveld refinement (21 parameters, 3296 degrees of freedom) yielded R = 0.0169, R/sub w/ = 0.0248 (R/sub expected/ = 0.0115). The structure of FeOCl(TTF)/sub 1/8.5/ was refined in space group Immm with a = 3.784 (2) A, b = 3.341 (2) A, and c = 25.97 (2) A, using a model in which the TTF molecules lie in the bc plane, with equal occupancy of the four possible sites, to give R = 0.0203, R/sub w/ = 0.0289, and R/sub expected/ = 0.0111 (28 parameters, 1894 degrees of freedom).
In search of cooperation: an historical analysis of work organization and management strategies

During the last decade, literature about work has increasingly focused on the importance of collective communication, tacit knowledge, and group activities. The idea of designing computer support for group-based work activities, which we loosely call 'cooperative work', is a useful and challenging one, for it represents a break from design approaches that focused on centralized and bureaucratic systems of communication and control.To get a clearer idea of the meaning of cooperative work, this article will look at historical patterns of work organization and management strategies. It will contrast user-centered concepts of cooperative work, with the idea of seeing cooperative work in the context of democracy in the workplace. The focus on workplace democracy has been a main theme in the Scandinavian systems tradition. The article uses the Scandinavian tradition, with its roots in a Labor Process Approach as a way to analyze the meaning of cooperation for workplace democracy and its implication for the design of computer support.
A new approach to the reconstruction of images from Radon projections

A new approach is proposed for reconstruction of images from Radon projections. Based on Fourier expansions in orthogonal polynomials of two and three variables, instead of Fourier transforms, the approach provides a new algorithm for the computed tomography. The convergence of the algorithm is established under mild assumptions.
The decline of welfare benefits in the U.S.: the role of wage inequality

Welfare benefits in the U.S. have experienced a much-studied secular decline since the mid-1970s. We explore a new hypothesis for this decline related to the increase in wage inequality in the labor market and the decline of real wages at the bottom of the distribution: we posit that voters prefer benefits which are tied to low-skilled wages. We test the hypothesis using a 1969–1992 panel of state-level data. An additional contribution of our analysis is the use of General Social Survey data on voter preferences for welfare which we combine with Current Population Survey data to determine the voter in each state who has the median preferred welfare benefit level. Our analysis reveals considerable evidence in support of a role for declining real wages in the decline of welfare benefits.
Assessment of Corrosion Risks to Aging Ships Using an Experience Database

Damages to ships due to corrosion are very likely, and the likelihood increases with the aging of ships. Risk and reliability approaches are more and more frequently applied in design and maintenance planning. These advanced approaches require reliable data reflecting the structural condition of ships in service. Such data is scarce. This paper presents a database of corrosion wastage. It is based on over 110,00 thickness measurements recently collected from 140 trading tankers. This database is larger than most other corrosion databases in the public domain. Corrosion wastage exhibits a high level of variability. In addition to thickness measurements of individual structural members, this database also has information on hull girder’s geometrical properties and strength of ships in service. Corrosion wastage has an influence on the hull girder strength. Statistical interpretations of the database are used to represent corrosion wastage in oil tankers. The severity of corrosion is ranked by three levels: slight, moderate and severe levels corresponding respectively to 50, 75 and 95% cumulative probability on the database. The risks of corrosion wastage to aging ships’ structural integrity are assessed using the observations of the corrosion wastage database. The investigated risks are loss of local member’s strength, loss of global hull girder strength, and shortened inspection intervals. The experience database can be used in many aspects, such as design requirements for corrosion additions and wastage allowance for plate renewal, establishment of limits to hull girder strength of FPSOs, time variant reliability approach and risk based inspection schemes.
Deep Photometry of the Draco Dwarf Spheroidal Galaxy

We report the results of deep CCD photometry of two overlapping fields in the Draco dwarf spheroidal galaxy. We find (B-V)o, g = 0m.69, indicating a mean [Fe/H] = -2.0. The width of the giant branch below the horizontal branch is somewhat wider than our observational errors permit, from which we infer there is a spread in metallicities amongst the Draco giants, up to 0.8 dex, perhaps. Draco is found to contain numerous blue stragglers, like almost all other loosely bound halo systems. The number of such stars more massive than about 1.2 Min⊙ is roughly consistent with the number of anomalous cepheids discovered previously. It is not clear whether the blue stragglers represent a large number of mass transfer binaries or an intermediate age population, or both. A younger population component would help explain the galaxy’s red horizontal branch stars in spite of its low mean metallicity. Signs of a younger population are seen in the color magnitude diagram for the entire sample, and especially from the higher quality data from the smaller area observed in the overlap of the two fields.
Handling floating-point exceptions in numeric programs

There are a number of schemes for handling arithmetic exceptions that can be used to improve the speed (or alternatively the reliability) of numeric code. Overflow and underflow are the most troublesome exceptions, and depending on the context in which the exception can occur, they may be addressed either: (1) through a “brute force” reevaluation with extended range, (2) by reevaluating using a technique known as scaling, (3) by substituting an infinity or zero, or (4) in the case of underflow, with gradual underflow. In the first two of these cases, the offending computation is simply reevaluated using a safer but slower method. The latter two cases are cheaper, more automated schemes that ideally are built in as options within the computer system. Other arithmetic exceptions can be handled with similar methods. These and some other techniques are examined with an eye toward determining the support programming languages and computer systems ought to provide for floating-point exception handling. It is argued that the cheapest short-term solution would be to give full support to most of the required (as opposed to recommended) special features of the IEC/IEEE Standard for Binary Floating-Point Arithmetic. An essential part of this support would include standardized access from high-level languages to the exception flags defined by the standard. Some possibilities outside the IEEE Standard are also considered, and a few thought on possible better-structured support within programming languages are discussed.
Selective Probing of Photoinduced Charge and Spin Dynamics in the Bulk and Surface of a Topological Insulator

Topological insulators possess completely different spin-orbit coupled bulk and surface electronic spectra that are each predicted to exhibit exotic responses to light. Here we report time-resolved fundamental and second harmonic optical pump-probe measurements on the topological insulator Bi_2Se_3 to independently measure its photoinduced charge and spin dynamics with bulk and surface selectivity. Our results show that a transient net spin density can be optically induced in both the bulk and surface, which may drive spin transport in topological insulators. By utilizing a novel rotational anisotropy analysis we are able to separately resolve the spin depolarization, intraband cooling, and interband recombination processes following photoexcitation, which reveal that spin and charge degrees of freedom relax on very different time scales owing to strong spin-orbit coupling.
Black holes must die

Abstract In light of recent evidence suggesting a nonzero present-day cosmological constant [S. Perlmutter et al. (The Supernova Cosmology Project), Astrophys. J. 517 (1999) 565], Adams, Mbonye, and Laughlin [Phys. Lett. B 450 (1999) 339] have considered the evolution of black holes in the presence of vacuum energy. Using the assumption that Λ remains constant with time and a conjecture based on a paper by Mallett [Phys. Rev. D 33 (1986) 2201], they reach the remarkable conclusion that black holes with current mass greater than ∼2×10 −9 M ⊙ will not Hawking evaporate in the distant future, but will instead absorb vacuum energy and grow to roughly the de Sitter horizon size. In this letter we reexamine black hole evaporation in the presence of a cosmological constant, and find instead that all known black holes will eventually evaporate.
Heat and Mass Transfer From Freely Falling Drops

When a drop breaks free from a liquid film or feeding orifice and falls through an atmosphere of lower temperature it experiences a transient heat and mass transfer process involving acceleration, the development of hydrodynamic, thermal, and concentration boundary layers in the gas, oscillation of the drop shape, and the development of internal circulation within the drop. This problem, which is of importance in evaporative cooling systems, has been studied experimentally for water drops 3--6 mm in diameter falling through air. Study of a simplified set of governing equations indicates that similitude does not exist in this problem. However, it has been found that for this size range an approximate procedure based on the assumption of negligible internal thermal resistance and an empirical transient correction factor applied to the Ranz- Marshall correlation could describe the data very well.
Technology as Integral to a New Paradigm of Adult Education

Technology and adult education are often discussed as two separate subjects, yet just as it is impossible to live one day without the impact of technology, it is impossible to discuss adult education without considering technology. The growth of the field of adult education and the evolution of modern technology as well as the theorists and practitioners who were instrumental in moving the fields will be considered in this article as the foundation for a paradigm shift in adult education. Since effective adult education involves not only information dissemination but communication and collaboration among its participants, online learning activities and entire online courses influence how the field itself is viewed. This new paradigm will be explored in the current and future world of adult teaching and learning.
Banding, excitability and chaos in active nematic suspensions

Motivated by the observation of highly unstable flowing states in suspensions of microtubules and kinesin, we analyse a model of mutually propelled filaments suspended in a solvent. The system undergoes a mean-field isotropic–nematic transition for large enough filament concentrations when the nematic order parameter is allowed to vary in space and time. We analyse the model in two contexts: a quasi-one-dimensional channel with no-slip walls and a two-dimensional box with periodic boundaries. Using stability analysis and numerical calculations we show that the interplay between non-uniform nematic order, activity, and flow results in a variety of complex scenarios that include spontaneous banded laminar flow, relaxation oscillations and chaos.
Is technological change biased towards the unskilled in services? An empirical investigation

Abstract I fit a two-sector general equilibrium model to U.S. data in 1963–2005 in order to infer technological processes that affect the college premium. In skill intensive services factor augmenting technological change is slower for college graduates relative to less skilled workers. I find the opposite in the rest of the economy. This indicates that technological change is more complex than what we observe at the aggregate level. The results are consistent with changes in occupational mixes: low-skill workers in services reallocate into computer complementary occupations to a greater extent than college graduates in that sector. Occupational mixes in the rest of the private sector shift in the opposite direction. Thus, theoretical treatments of the underlying mechanisms of skill biased technological change may be improved by taking into account occupational mixes within broad education-sector groups.
Ab initio local-orbital density-functional method for transition metals and semiconductors

I develop an ab initio local-orbital method for transition metals and semiconductors. The method of calculation is based on the non-self-consistent Harris functional version of the local-density approximation. In particular, I use a generalization of the method of Sankey and Niklewski to include $d$ orbitals in the basis set, thus allowing the application to transition metals. This method is shown to produce excellent results for the band structure of crystalline Al, Si, and Pt (as well as other transition-metal compounds). This method, along with a dynamical quenching algorithm, is employed to study Pt(111) surface relaxation. The results of the calculations show a slight expansion of the top-layer spacing by 0.8% relative to the bulk spacing, which is in good agreement with experiment.
Examining the temperature dependence of ethanol (E85) versus gasoline emissions on air pollution with a largely-explicit chemical mechanism

Abstract The increased use of ethanol in transportation fuels warrants an investigation of its consequences. An important component of such an investigation is the temperature dependence of ethanol and gasoline exhaust chemistry. We use the Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate complex chemistry to examine such effects. The MCM has over 13,500 organic reactions and 4600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. Although we use a box model for this study, we determine and demonstrate in a separate study that the speed of the MCM with SMVGEAR II allows the MCM to be modeled in 3-dimensions. We also verified the accuracy of the model in comparison with smog chamber data. We then use the model with species-resolved tailpipe emissions data for E85 (15% gasoline, 85% ethanol fuel blend) and gasoline vehicles to compare the impact of each on nitrogen oxides, organic gases, and ozone as a function of ambient temperature and background concentrations, using Los Angeles in 2020 as a base case. We use two different emissions sets – one is a compilation of exhaust and evaporative data taken near 24 °C and the other from exhaust data taken at −7 °C – to determine how atmospheric chemistry and emissions are affected by temperature. We include diurnal effects by examining two day scenarios. We find that, accounting for chemistry and dilution alone, the average ozone concentrations through the range of temperatures tested are higher with E85 than with gasoline by ∼7 part per billion volume (ppbv) at higher temperatures (summer conditions) to ∼39 ppbv at low temperatures and low sunlight (winter conditions) for an area with a high nitrogen oxide (NOx) to non-methane organic gas (NMOG) ratio. The results suggest that E85's effect on health through ozone formation becomes increasingly more significant relative to gasoline at colder temperatures due to the change in exhaust emission composition at lower temperatures. Acetaldehyde and formaldehyde concentrations are also much higher with E85 at cold temperatures, which is a concern because both are considered to be carcinogens. These could have implications for wintertime use of E85. Peroxy acetyl nitrate (PAN), another air pollutant of concern, increases with E85 by 0.3–8 ppbv. The sensitivity of the results to box size, initial background concentrations, background emissions, and water vapor were also examined.
Analysis and simulation of parallel signature analyzers

Abstract Parallel signature analyzers (PSAs) implemented as multiple input linear feedback shift registers are very useful in compressing test response data in digital circuits. In this paper, some analytical results on error detection using a class of PSAs are presented. The concept of monitoring the most significant bit of a PSA is introduced. Finally, a PASCAL simulator, called SIGLYZER, to study the effectiveness of PSAs in detecting errors in test response data, is described. The use of the SIGLYZER as a design tool is also explained.
Spectral Index of the Diffuse Radio Background Measured from 100 to 200 MHz

The mean absolute brightness temperature of the diffuse radio background was measured as a function of frequency in a continuous band between 100 and 200 MHz over an effective solid angle of ~π sr at high Galactic latitude. A spectral brightness temperature index of β = 2.5 ± 0.1 (αS = 0.5) was derived from the observations, where the error limits are 3σ and include estimates of the instrumental systematics. Zenith drift scans with central declination δ = –26.5° and spanning right ascensions 0 < α < 10 h yielded little variation in the mean spectral index. The mean absolute brightness temperature at ν = 150 MHz was found to reach a minimum of T = 237 ± 10 K at α = 2.5 h. Combining these measurements with those of Haslam et al. yields a spectral index of β = 2.52 ± 0.04 between 150 < ν < 408 MHz.
Double Bubbles in Assets Markets With Multiple Generations

We construct an asset market in a finite horizon overlapping-generations environment. Subjects are tested for comprehension of their fundamental value exchange environment and then reminded during each of 25 periods of the environment's declining new value. We observe price bubbles forming when new generations enter the market with additional liquidity and bursting as old generations exit the market and withdrawing cash. The entry and exit of traders in the market creates an M shaped double bubble price path over the life of the traded asset. This finding is significant in documenting that bubbles can reoccur within one extended trading horizon and, consistent with previous cross-subject comparisons, shows how fluctuations in market liquidity influence price paths. We also find that trading experience leads to price expectations that incorporate fundamental value.
Verblunsky coefficients with Coulomb-type decay

We show that probability measures on the unit circle associated with Verblunsky coefficients obeying a Coulomb-type decay estimate have no singular continuous component.
Existence of needle crystals in local models of solidification.

The way in which surface tension acts as a singular perturbation to destroy the continuous family of needle-crystal solutions of the steady-state growth equations is analyzed in detail for two local models of solidification. All calculations are performed in the limit of small surface tension or, equivalently, small velocity. The basic mathematical ideas are introduced in connection with a quasilinear, isotropic version of the geometrical model of Brower et al., in which case the continuous family of solutions disappears completely. The formalism is then applied to a simplified boundary-layer model with an anisotropic kinetic attachment coefficient. In the latter case, the solvability condition for the existence of needle crystals can be satisfied whenever the coefficient of anisotropy is arbitrarily small but nonzero.
Atmospheric tides between 80 km and 120 km

Abstract The structure and variability of tides in the 80 – 120 km height region are reviewed. Particularly emphasised are seasonal-latitudinal variations in the vertical structure of diurnal and semidiurnal winds between 70 – 100 km as measured by meteor and partial reflection drift radars, and tidal temperatures determined by incoherent scatter radars between 100 and 140 km. Variations in tidal structures with longitude, from day to day, and during equinoctial transition periods are also addressed.
Crystal manyfold universes in AdS space

Abstract We derive crystal braneworld solutions, comprising of intersecting families of parallel n +2-branes in a 4+ n -dimensional AdS space. Each family consists of alternating positive and negative tension branes. In the simplest case of exactly orthogonal families, there arise different crystals with unbroken 4 D Poincare invariance on the intersections, where our world can reside. A crystal can be finite along some direction, either because that direction is compact, or because it ends on a segment of AdS bulk, or infinite, where the branes continue forever. If the crystal is interlaced by connected 3-branes directed both along the intersections and orthogonal to them, it can be viewed as an example of a Manyfold universe proposed recently by Arkani-Hamed, Dimopoulos, Dvali and the author. There are new ways for generating hierarchies, since the bulk volume of the crystal and the lattice spacing affect the 4 D Planck mass. The low energy physics is sensitive to the boundary conditions in the bulk, and has to satisfy the same constraints discussed in the Manyfold universe. Phenomenological considerations favor either finite crystals, or crystals which are infinite but have broken translational invariance in the bulk. The most distinctive signature of the bulk structure is that the bulk gravitons are Bloch waves, with a band spectrum, which we explicitly construct in the case of a 5-dimensional theory.
4-azido-2-iodo-3,5,6-trifluorophenylcarbonyl derivatives. A new class of functionalized and iodinated perfluorophenyl azide photolabels

Abstract Iodinated perfluorophenyl azide 4 and NHS ester 7 were synthesized. Photolysis of azide 4 in DEA/cyclohexane gave N-H insertion product 9 (24%). For photolabeling purposes, this constitutes a significant improvement over the behavior of non-fluorinated analogues.
Natural Law and the Ethics of Discourse

This essay argues that Plato's critical analysis of the ethics of discourse is superior to Habermas', and more generally that Habermas has no sufficient reason to propose or suppose the philosophical superiority of “modernity.” The failure of Hume and Kant and much modern philosophy to understand the concept and content of reasons for action underlies Habermas' attempted distinction between ethics and morality, and Rawls' concept of public reason. A proper study of discourse also yields a metaphysics of the person, and thus reinforces the ethics.
Interactive design of 3-D computer-animated legged animal motion

We present a visually interactive approach to the design of 3-D computer-animated legged animal motion in the context of the PODA computer animation system. The design process entails the interactive specification of parameters which drive a computational model for animal movement. The animator incrementally modifies a framework for establishing desired limb and body motion as well as the constraints imposed by physical dynamics (Newtonian mechanical properties) and temporal restrictions. PODA uses the desired motion and constraints specified by the animator to produce motion through an idealized model of the animal's adaptive dynamic control strategies.
Acid Penetration in Natural Fracture Networks

In this paper we present a methodology for predicting the propagation of acid along natural fracture networks and the resulting etching of the fracture walls. The natural fracture network is modeled as a system of intersecting fractures that form a main pathway for acid transport and dissolution. The tails of the intersected fractures increase the leakoff from the main pathway and are accounted for in the model. The fracture-network-acidizing model is supported by comparisons with laboratory experiments and smaller-scale simulations that determined the nature of acid channeling at fracture intersections. Model results illustrate the effects variations in fracture properties have on acid propagation. The model predicts deeper acid penetration under matrix conditions than would be possible with matrix flow only.
A Possible Bifurcation in Atmospheres of Strongly Irradiated Stars and Planets

We show that under certain circumstances the differences between the absorption mean and Planck mean opacities can lead to multiple solutions for an LTE atmospheric structure. Since the absorption and Planck mean opacities are not expected to differ significantly in the usual case of radiative equilibrium, nonirradiated atmospheres, the most interesting situations in which the effect may play a role are strongly irradiated stars and planets, and also possibly structures in which there is a significant deposition of mechanical energy, such as stellar chromospheres and accretion disks. We have presented an illustrative example of a strongly irradiated giant planet in which the bifurcation effect is predicted to occur for a certain range of distances from the star.
The Proportional Uap Characterizes Weak Hilbert Spaces

We prove that a Banach space has the uniform approximation property with proportional growth of the uniformity function iff it is a weak Hilbert space.
Sample Complexity of Model-Based Search

We consider the problem of searching a domain for points that have a desired property, in the special case where the objective function that determines the properties of points is unknown and must be learned during search. We give a parallel to PAC learning theory that is appropriate for reasoning about the sample complexity of this problem. The learner queries the true objective function at selected points, and uses this information to choose models of the objective function from a given hypothesis class that is known to contain a correct model. These models are used to focus the search on more promising areas of the domain. The goal is to find a point with the desired property in a small number of queries. We define an analog to VC dimension, needle dimension, to be the size of the largest sample in which any single point could have the desired property without the other points' values revealing this information. We give an upper bound on sample complexity that is linear in needle dimension for a natural type of search protocol and a linear lower bound for a class of constrained problems. We also describe the relationship between needle dimension and VC dimension, explore connections between model-based search and active concept learning (including several novel positive results in active learning), and consider a scale-sensitive version of needle dimension. Several simple examples illustrate the dependence of needle dimension on features of search problems.
The preparation of a hexacyclic intermediate for the synthesis of strychnos alkaloids

Abstract Hexacyclic intermediate 17 has been synthesized in nine steps from aldehyde 3 . Key steps include the selective reduction of aldehyde 3 , the stereoselective introduction of an allyl group via the Sakurai reaction and the ozonolysis/dehydrative cyclization to afford bridgehead enamine 17 . Hexacyclic intermediate 17 has been synthesized in nine steps from aldehyde 3. Key steps include the selective reduction of aldehyde 3, the stereoselective introduction of an allyl group via the Sakurai reaction and the ozonolysis/dehydrative cyclization to afford bridgehead enamine 17.
Cascade assembly of the benz[a]anthraquinone ring system common to the angucycline antibiotics

A benz[a]anthraquinone ring system, common to a group of angucycline antibiotics, has been prepared by a unique cascade of reactions. The reaction sequence was initiated by a Suzuki–Miyaura cross-coupling between a bromoquinone and vinyl boronic anhydride. The reaction product is proposed to undergo a 6π-electron cyclization triggered by reductive activation of the quinone. The reaction process is proposed to be autocatalytic.
Innovation, market structure and the holdup problem: investment incentives and coordination ☆

Abstract I analyze the innovation incentives under monopoly and duopoly provision of horizontally differentiated products purchased via bilateral negotiations, integrating the market structure and innovation literature with the holdup literature. I show that competition can improve local incentives for non-contractible investment. Because innovation levels are generally strategic substitutes, however, there can be multiple duopoly equilibria. In some circumstances, monopoly can provide a coordination device that can lead to greater expected welfare despite inferior local innovation incentives. The conditions for this to be the case, however, are quite restrictive.
Optimization of structured mean field objectives

In intractable, undirected graphical models, an intuitive way of creating structured mean field approximations is to select an acyclic tractable subgraph. We show that the hardness of computing the objective function and gradient of the mean field objective qualitatively depends on a simple graph property. If the tractable subgraph has this property---we call such subgraphs v-acyclic---a very fast block coordinate ascent algorithm is possible. If not, optimization is harder, but we show a new algorithm based on the construction of an auxiliary exponential family that can be used to make inference possible in this case as well. We discuss the advantages and disadvantages of each regime and compare the algorithms empirically.
A Characterization of Hyperbolic Geometry among Hilbert Geometry

In this paper we characterize hyperbolic geometry among Hilbert geometry by the property that three medians of any hyperbolic triangle all pass through one point.
Control, Incentives and Competition: The Impact of Reform on Chinese State‐owned Enterprises

Through the lens of the theory of the firm, I examine how a series of reforms affected the performance of Chinese state-owned enterprises with a panel dataset of more than 500 firms. The study finds that performance improved with various reforms such as increasing competition, appointing new managers, using firm-level pay sensitivity, raising marginal profit retention rates and allowing managers to determine wages and to make production decisions. Adopting performance contracts did not improve performance significantly. These results confirm the importance of competition, control rights, managerial and internal incentives, as emphasized by the theory of the firm.
Assessment of the toxicity of delivery systems for injectable contraceptives.

Abstract A favored approach to sustained release of contraceptive drugs has been to incorporate them into polymers that undergo gradual hydrolysis. Assessment of the safety of such delivery systems when used for parenteral delivery of drugs must take account of both local effects and effects at a distance mediated by the products of hydrolysis. Many of the problems of such an assessment are identical with those presented by any “drug” substance and similar approaches are appropriate. Special aspects are associated with the physical damage that may be caused by implant masses, with the carcinogenic potential of impervious materials of large physical size, with the fact that cells at the site of injection may be exposed to disproportionately high concentrations of breakdown products for a long period of time, with possible antigenicity of macro-molecular materials, and with the fact that partial hydrolysis may release a series of fragments of differing molecular weights.
The equity premium puzzle: An artificial neural network approach

Purpose – In recent years, equity premiums have been unusually large and efforts to forecast them have been largely unsuccessful. This paper presents evidence suggesting that artificial neural networks (ANNs) outperform traditional statistical methods and can forecast equity premiums reasonably well.Design/methodology/approach – This study replicates out‐of‐sample estimates of regression using ANN with economic fundamentals as inputs. The theory states that recent large equity premium values cannot be explained (the equity premium puzzle).Findings – The dividend yield variable was found to produce the best out‐of‐sample forecasts for equity premium.Research limitations/implications – Although the equity premium puzzle can be partly explained by fundamentals, they do not imply immediate policy prescriptions since all forecasting techniques including ANN are susceptible to joint assumptions of the techniques and the models used.Practical implications – This result is useful in capital asset pricing model an...
Muscarinic receptor subtypes in airways

Muscarinic receptor subtypes in the airways appear to subserve different physiological functions. M1-receptors facilitate neurotransmission through parasympathetic ganglia and enhance cholinergic reflexes, but are also localized to alveolar walls. M2-receptors act as autoreceptors on post-ganglionic cholinergic nerves and inhibit acetylcholine release. There is some evidence that they may be defective in asthma (as a consequence of airway inflammation?) and this may enhance cholinergic reflexes and account for beta-blocker-induced asthma. M2-receptors in airway smooth muscle may also counteract the bronchodilator action of beta-agonists. M3-receptors mediate contractile responses in airway smooth muscle via phosphoinositide hydrolysis, and are the predominant receptors on submucosal glands and airway vascular endothelium. M4- and M5-receptors have not been identified in human airways, but in rabbit lung M4-receptors are expressed on alveolar walls and smooth muscle. Anticholinergic drugs which selectively block M3 and M1-receptors may have an advantage over currently used non-selective antagonists in the treatment of airway obstruction.
Synthesis of cyclohexanone-based cathepsin B inhibitors that interact with both the S and S′ binding sites

Abstract Solution and solid phase methods are described for the synthesis of inhibitors of the cysteine protease cathepsin B. These inhibitors are based on a cyclohexanone pharmacophore and are designed to interact with both the S and S′ subsites of the enzyme active site.
Stereoselective Borylative Ketone-Diene Coupling

In the presence of catalytic Ni(cod)2 and P(t-Bu)3, ketones, dienes, and B2(pin)2 undergo a stereoselective multicomponent coupling reaction. Upon oxidation, the reaction furnishes 1,3-diols as the major reaction product.
Integration of CAD and FEA for Concurrent Engineering Design of Sheet Stamping

The tedious process of building an input model and of manual communication between CAD and Finite Element Analysis (FEA) significantly restricts the designers from using FEA, particularly in preliminary design. Most of the previous works concentrate on expediting this process by interfacing CAD and FEA. This paper proposes full integration of FEA simulation code within a CAD system, thus several problems are avoided. The section-based FEA is used as better suited to early design. It requires, comparing to the 3-D FEA, development of additional CAD functions to extract appropriate sections from the CAD model. The proposed integrated system allows for rapid use of the FEA and unifies the design environment to avoid inconsistency. It provides a mechanism to specify the part orientation relative to the punch traveling direction to support tipping. It also extracts the geometrical data ofa specified section to automatically build and store a FEA input model. The numerical simulation of the process can be then performed without exiting the CAD system. Both existing as well as newly developed CAD functions, needed for the proposed integration system, are presented. The feasibility and advantages of such integration is demonstrated on the developed prototype system.
Africa's Growth Tragedy: Policies and Ethnic Divisions

Explaining cross-country differences in growth rates requires not only an understanding of the link between growth and public policies, but also an understanding of why countries choose different public policies. This paper shows that ethnic diversity helps explain cross-country differences in public policies and other economic indicators. In the case of Sub-Saharan Africa, economic growth is associated with low schooling, political instability, underdeveloped financial systems, distorted foreign exchange markets, high government deficits, and insufficient infrastructure. Africa's high ethnic fragmentation explains a significant part of most of these characteristics.
Topological constraints at the Theta-point: Closed loops at two loops

We map the problem of self-avoiding random walks in a Θ solvent with a chemical potential for writhe to the three-dimensional symmetric U(N)-Chern-Simons theory as N → 0. We find a new scaling regime of topologically constrained polymers, with critical exponents that depend on the chemical potential for writhe which gives way to a fluctuation-induced first-order transition.
Varied Molecular Interactions at the Active Sites of Several DNA Polymerases: Nonpolar Nucleoside Isosteres as Probes.

We describe a survey of protein−DNA interactions with seven different DNA polymerases and reverse transcriptases, carried out with nonpolar nucleoside isosteres F (a thymidine analog) and Z and Q (...
Ganalyzer: A Tool for Automatic Galaxy Image Analysis

We describe Ganalyzer, a model-based tool that can automatically analyze and classify galaxy images. Ganalyzer works by separating the galaxy pixels from the background pixels, finding the center and radius of the galaxy, generating the radial intensity plot, and then computing the slopes of the peaks detected in the radial intensity plot to measure the spirality of the galaxy and determine its morphological class. Unlike algorithms that are based on machine learning, Ganalyzer is based on measuring the spirality of the galaxy, a task that is difficult to perform manually, and in many cases can provide a more accurate analysis compared to manual observation. Ganalyzer is simple to use, and can be easily embedded into other image analysis applications. Another advantage is its speed, which allows it to analyze ~10,000,000 galaxy images in five days using a standard modern desktop computer. These capabilities can make Ganalyzer a useful tool in analyzing large data sets of galaxy images collected by autonomous sky surveys such as SDSS, LSST, or DES. The software is available for free download at http://vfacstaff.ltu.edu/lshamir/downloads/ganalyzer, and the data used in the experiment are available at http://vfacstaff.ltu.edu/lshamir/downloads/ganalyzer/GalaxyImages.zip.
Property rights and farm efficiency: evidence from Ukraine

This paper studies the effect of property rights regime on farm efficiency, using a high-quality representative sample from Ukraine’s agricultural sector. At the farm level, I find that a fully delineated and secure system of property rights leads to large positive gains in efficiency. In Ukraine, farms with a well-defined and enforced governance system have 20% higher level of productive efficiency and 9% higher level of technical efficiency as compared to farms with a contractual incompleteness. The ownership arrangement has profound effect on agricultural production in Ukraine.
Dimensions of Structural Disadvantage: A Latent Class Analysis of a Neighborhood Measure in Child Welfare Data

ABSTRACT Contextual constructs, such as neighborhood structure, may contribute to child welfare involvement. Secondary data analysis is used with the nationally representative, longitudinal National Survey of Child and Adolescent Well-Being-II (N = 5,872). This study employs latent class analysis (LCA) to identify the number of classes needed to explain the distribution of caregiver responses on the Community Environment Scale. LCA is ideal for this study to identify meaningful groups of caregivers involved with child welfare using neighborhood risk factors. Three latent classes are identified: high social order/medium social capital; high social order/low social capital; low social order/low social capital. Multinomial logistic regression tests whether there are significant differences across the classes, partially validating the LCA that poor, minority caregivers live in neighborhoods with lower social order and capital. Understanding neighborhoods as “high” versus “low” risk may not fully illuminate co...
Connecting Reionization to the Local Universe

We present results of combined N-body and three-dimensional reionization calculations to determine the relationship between reionization history and local environment in a volume of 1 Gpc h –1 across and a resolution of about 1 Mpc. We achieve this by applying three-dimensional simulations of reionization, based on the extended Press-Schechter formalism, to the same initial conditions as the N-body simulations. We resolve about 2 × 106 halos of mass greater than ~1012 M ☉ at z = 0, and determine the relationship between halo mass and reionization epoch for galaxies and clusters. For our fiducial reionization model, in which reionization begins at z ~ 15 and ends by z ~ 6, we find a strong bias for cluster-size halos to be in the regions that reionized first, at redshifts 10 < z < 15. Consequently, material in clusters was reionized within relatively small regions, on the order of a few Mpc, implying that all clusters in our calculation were reionized by their own progenitors. Milky Way mass halos were on average reionized later and by larger regions, with a distribution most similar to the global one, indicating that low-mass halos are nearly uncorrelated with reionization when only halo mass is taken as a prior. On average, most halos with mass less than 1013 M ☉ were reionized internally, while almost all halos with masses greater than 1014 M ☉ were reionized by their own progenitors. We briefly discuss the implications of this work in light of the missing satellites problem and how this new approach may be extended further.
Phorboxazole synthetic studies: the C3–C15 bis-oxane segment

Abstract The enantioselective synthesis of the C3–C15 bis-oxane segment of the phorboxazoles has been accomplished from 3- t -butyldiphenylsilyloxypropanal in 9 steps (>90% ee).
Depressurization solutions of vented enclosures during launch

It is often necessary to vent an enclosure to allow a controlled depressurization when it is exposed to a decreasing external pressure. This paper derives analytical expressions that can be used to estimate this depressurization. These analytical expressions allow the design of enclosures intended for space launch and other applications. The analytical solutions are compared to numerical solutions and validated by a series of experiments which demonstrate their accuracy.
The structure of the planets Jupiter and Saturn

Planetary models for Jupiter and Saturn are computed using a fourth-order theory and an equation of state for the molecular hydrogen and helium planetary envelopes taken from the Monte Carlo calculations of Slattery and Hubbard (1976). Models for Jupiter are found that have a small amount of heavy elements either mixed with hydrogen and helium throughout the interior of the planet or concentrated in a small dense core. Saturn is modeled with a solar-composition hydrogen and helium envelope and a small dense core. It is concluded that the molecular equation of state linked with suitable interior equations of state can produce Jovian models which satisfy the observational data. The planetary models show that the enrichment of heavy elements (relative to solar composition) is approximately 3 times for Jupiter and 10 times for Saturn.
Pharmacologic inhibition of ROCK2 suppresses amyloid-β production in an Alzheimer's disease mouse model.

Alzheimer9s disease (AD) is the leading cause of dementia and has no cure. Genetic, cell biological, and biochemical studies suggest that reducing amyloid-β (Aβ) production may serve as a rational therapeutic avenue to delay or prevent AD progression. Inhibition of RhoA, a Rho GTPase family member, is proposed to curb Aβ production. However, a barrier to this hypothesis has been the limited understanding of how the principal downstream effectors of RhoA, Rho-associated, coiled-coil containing protein kinase (ROCK) 1 and ROCK2, modulate Aβ generation. Here, we report that ROCK1 knockdown increased endogenous human Aβ production, whereas ROCK2 knockdown decreased Aβ levels. Inhibition of ROCK2 kinase activity, using an isoform-selective small molecule (SR3677), suppressed β-site APP cleaving enzyme 1 (BACE1) enzymatic action and diminished production of Aβ in AD mouse brain. Immunofluorescence and confocal microscopy analyses revealed that SR3677 alters BACE1 endocytic distribution and promotes amyloid precursor protein (APP) traffic to lysosomes. Moreover, SR3677 blocked ROCK2 phosphorylation of APP at threonine 654 (T654); in neurons, T654 was critical for APP processing to Aβ. These observations suggest that ROCK2 inhibition reduces Aβ levels through independent mechanisms. Finally, ROCK2 protein levels were increased in asymptomatic AD, mild cognitive impairment, and AD brains, demonstrating that ROCK2 levels change in the earliest stages of AD and remain elevated throughout disease progression. Collectively, these findings highlight ROCK2 as a mechanism-based therapeutic target to combat Aβ production in AD.