cssi/SciSciGPT-SciSciNet huggingface dataset:
Verifying sequential consistency on shared-memory multiprocessors by model checking

The memory model of a shared-memory multiprocessor is a contract between the designer and the programmer of the multiprocessor. A memory model is typically implemented by means of a cache-coherence protocol. The design of this protocol is one of the most complex aspects of multiprocessor design and is consequently quite error-prone. However, it is imperative to ensure that the cache-coherence protocol satisfies the shared-memory model. We present a novel technique based on model checking to tackle this difficult problem for the important and well-known shared-memory model of sequential consistency. Surprisingly, verifying sequential consistency is undecidable in general, even for finite-state cache-coherence protocols. In practice, cache-coherence protocols satisfy the properties of causality and data independence. Causality is the property that values of read events flow from values of write events. Data independence is the property that all traces can be generated by renaming data values from traces where the written values are pairwise distinct. We show that, if a causal and data independent system also has the property that the logical order of write events to each location is identical to their temporal order, then sequential consistency is decidable. We present a novel model checking algorithm to verify sequential consistency on such systems for a finite number of processors and memory locations and an arbitrary number of data values.
Spherical navigator echoes for full 3D rigid body motion measurement in MRI.

We developed a 3D spherical navigator (SNAV) echo technique that can measure rigid body motion in all six degrees of freedom simultaneously by sampling a spherical shell in k-space. 3D rotations of an imaged object simply rotate the data on this shell and can be detected by registration of k-space magnitude values. 3D translations add phase shifts to the data on the shell and can be detected with a weighted least-squares fit to the phase differences at corresponding points. MRI pulse sequences were developed to study k-space sampling strategies on such a shell. Data collected with a computer-controlled motion phantom with known rotational and translational motions were used to evaluate the technique. The accuracy and precision of the technique depend on the sampling density. Roughly 2000 sample points were necessary for accurate detection to within the error limits of the motion phantom when using a prototype time-intensive sampling method. This number of samples can be captured in an approximately 27-ms double excitation SNAV pulse sequence with a 3D helical spiral trajectory. Preliminary results with the helical SNAV are encouraging and indicate that accurate motion measurement suitable for retrospective or prospective correction should be feasible with SNAV echoes.
Structure and Shear Response in Nanometer-Thick Films

Simulations of the structure and dynamics of fluid films confined to a thickness of a few molecular diameters are described. Confining walls introduce layering and in-plane order in the adjacent fluid. The latter is essential to transfer of shear stress. As the film thickness is decreased, by increasing pressure or decreasing the number of molecular layers, the entire film may undergo a phase transition. Spherical molecules tend to crystallize, while short-chain molecules enter a glassy state with strong local orientational and translational order. These phase transitions lead to dramatic changes in the response of the film to imposed shear velocities v. Spherical molecules show an abrupt transition from Newtonian response to a yield stress as they crystallize. Chain molecules exhibit a continuously growing regime of non-Newtonian behavior where the shear viscosity drops as v−2/3 at constant normal load. The same power law is found for a wide range of parameters, and extends to lower and lower velocities as a glass transition is approached. Once in the glassy state, chain molecules exhibit a finite yield stress. Shear may occur either within the film or at the film/wall interface. Interfacial shear dominates when films become glassy and when the film viscosity is increased by increasing the chain length.
Determination of enantiomeric purity of alcohols using achiral diphenyldichlorosilane

Abstract Diphenyldichlorosilane was used as a dimerization agent to convert enantiomeric alcohols to a mixture of meso and dl diastereomeric silyl acetals. The meso and dl compounds can be distinguished by 13 C NMR method and their ratio can be used to evaluate the optical purity of the alcohols.
Novel synthesis of desymmetrized resorcinol derivatives: aryl fluoride displacement on deactivated substrates.

A short, high-yielding synthesis of differentially substituted resorcinol derivatives has been developed that utilizes 1,3-difluorobenzene as the starting material and employs sequential nucleophilic aromatic substitution (SNAr) reactions to generate desymmetrized products. The scope and limitations of the second SNAr reaction on the deactivated 1-alkoxy-3-fluorobenzene intermediates have been investigated. This methodology has also been employed in the synthesis of desymmetrized catechol derivatives from 1,2-difluorobenzene.
Observation of strong Coulomb blockade in resistively isolated tunnel junctions

Abstract We report measurements of the Coulomb-blockade current in resistively isolated (RIsol≫h/e2) tunnel junctions for the temperature range 60 mK mK where the charging energy Ec is much greater than the thermal energy. A zero-bias resistance R0 of up to 104RT (the tunnel resistance of the bare junction) is obtained. For eV≪Ec, the I-V curves for a given RIsol scale as a function of V/T, with I∝Vα(RIsol) over a range of V. The data agree well with numerical calculations of the tunneling rate that include environmental effects.
Early Postoperative Oral Feeding After Colectomy: An Analysis of Factors That May Predict Failure

Background: Previous studies have shown that early postoperative oral feeding is feasible. Traditionally patients were fed when flatus or defecation documented the return of bowel function. This study was undertaken to determine factors that may preclude early feeding. Methods: One hundred four successive patients underwent colorectal surgery from October 1999 to January 2001. Eighty-nine patients started an oral dieteither on postoperative day 1 or 2. Their clinical outcomes were recorded prospectively. Fifteen of the 104 patients were excluded for small-bowel resection (5 patients), perioperative complications (5 patients), prior radiation (3 patients), and small-bowel obstruction (2 patients). A failure in postoperative feeding consisted of nausea, vomiting, or readmission. Results: The mean age of our cohort was 65 years (range, 28 to 87 years). There were 45 male and 44 female patients. The mean postoperative hospital stay was 6 days (range, 3 to 13 days). The median American Society of Anesthesiolog...
Explaining the Magnitude of Liquidity Premia: The Roles of Return Predictability, Wealth Shocks, and State‐Dependent Transaction Costs

Constantinides (1986) documents how the impact of transaction costs on per-annum liquidity premia in the standard dynamic allocation problem with i.i.d. returns is an order of magnitude smaller than the cost rate itself. Recent papers form portfolios sorted on liquidity measures and find spreads in expected per-annum return that are the same order of magnitude as the transaction cost spread. When we allow returns to be predictable and introduce wealth shocks calibrated to labor income, transaction costs are able to produce per-annum liquidity premia that are the same order of magnitude as the transaction cost spread. A NUMBER OF RECENT PAPERS have found a difference in expected return across portfolios sorted on liquidity measures. While the finding of a difference is not surprising, the magnitude is, with expected return differences on the order of 6% to 7% per annum. 1 The magnitude of the difference seems too large to be explained by realistic transaction costs. In particular, the seminal work of Constantinides (1986) documents how investor utility is largely insensitive to transaction costs when the investor solves the canonical problem of i.i.d. returns calibrated to U.S. data, no nonfinancial income, and a constant proportional cost rate. For realistic proportional costs, Constantinides shows that the per-annum liquidity premium that must be offered to induce a constant relative risk aversion (CRRA) investor to hold the transaction-cost asset instead of an otherwise identical no-transaction-cost asset is an order of magnitude smaller than the transaction-cost rate itself. Constantinides also provides intuition for this result. Investors respond to transaction costs by turning over their portfolios much less frequently than annually because an investor’s value function is insensitive to quite large deviations from the optimal no-transaction-cost portfolio allocation. Our paper bridges the gap between this theoretical result
Information Transmission and the Bullwhip Effect: An Empirical Investigation

The bullwhip effect is the amplification of demand variability along a supply chain: a company bullwhips if it purchases from suppliers more variably than it sells to customers. Such bullwhips (amplifications of demand variability) can lead to mismatches between demand and production and hence to lower supply chain efficiency. We investigate the bullwhip effect in a sample of 4,689 public U.S. companies over 1974--2008. Overall, about two-thirds of firms bullwhip. The sample's mean and median bullwhips, both significantly positive, respectively measure 15.8% and 6.7% of total demand variability. Put another way, the mean quarterly standard deviation of upstream orders exceeds that of demand by $20 million. We decompose the bullwhip by information transmission lead time. Estimating the bullwhip's information-lead-time components with a two-stage estimator, we find that demand signals firms observe with more than three-quarters' notice drive 30% of the bullwhip, and those firms observe with less than one-quarter's notice drive 51%. From 1974--1994 to 1995--2008, our sample's mean bullwhip dropped by a third. This paper was accepted by Christian Terwiesch, operations management.
Existence of Stationary Equilibrium in the Markets for New and Used Durable Goods

Abstract We prove the existence of stationary equilibrium in the primary and secondhand markets for an indivisible consumer durable in a general model with stochastic degradation and endogenous scrappage decisions. Unlike Rust (Econometrica 53 (1985) 783), we introduce transaction costs in the model as a motivation for consumer holdings of durables across multiple quality levels. Our technique allows for both multiple types of durables (e.g., Porsche and BMW) and relaxation of the single-crossing condition on consumer tastes. We provide a simple example showing how increasing transaction costs affect secondhand prices, eventually (for sufficiently costly transactions) closing the secondhand market altogether.
Multiple parton scattering in nuclei: Twist-four nuclear matrix elements and off-forward parton distributions

Multiple parton scatterings inside a large nucleus generally involve highertwist nuclear parton matrix elements. The gluon bremsstrahlung induced by multiple scattering depends not only on direct parton matrix elements but also on momentum-crossed ones, due to the Landau-Pomeranchuk-Migdal interference effect. We show that both types of twist-four nuclear parton matrix elements can be factorized approximately into the product of twist-two nucleon matrix elements in the limit of extremely large nuclei, A → ∞, as assumed in previous studies. Due to the correlative nature of the twist-four matrix elements under consideration, it is actually the off-forward parton distributions that appear naturally in this decomposition, rather than the ordinary diagonal distributions probed in deeply-inelastic scattering. However, we argue that the difference between these two distribution classes is small in certain kinematic regimes. In these regions, the twist-four nuclear parton matrix elements are evaluated numerically and compared to the factorized form for different nuclear sizes within a schematic model of the two-nucleon correlation function. The nuclear size dependence is found to be A 4/3 in the limit of large A, as expected. We find that the factorization is reasonably good when the momentum fraction carried by the gluon field is moderate. The deviation can be more than a factor of 2, however, for small gluon momentum fractions, where the gluon distribution is very large.
Do Animals Need Rights

The idea of animal rights makes many people skittish. Even many advocates of better treatment of animals sense that the language of rights is misplaced and unhelpful in the forum of debate about the ethical treatment of animals. Rights theory is the intellectual home of these misgivings. This paper has two parts. In the first, I speak through a composite figure I call the animal-rights skeptic. The skeptic weaves views taken from the “will” (or “choice”) theory of the conceptual nature of rights together with substantive normative argument that emphasizes reciprocity and autonomy as the justificatory basis for assigning rights. The skeptic concludes that the interests of animals in avoiding mistreatment can be fully served without assigning them rights, and that therefore nothing is denied to them by recognizing that they are not capable of rights holding. In short, animals do not need rights. The second part of the paper counters the skeptic, and points to important functions that rights alone can perform for animals. Rights have a generative nature, making them more valuable that the duties correlative to them at a given time; rights express respect for rights holders in a way that no set of protective indirect duties can duplicate; and rights are more readily proxy-able, giving standing for animals’ advocates. Animals, I conclude, do need rights.
The effect of disorder in superfluid double layer graphene

We investigate the superfluid properties of disordered double layer graphene systems using the non-equilibrium Green?s function formalism. The complexity of such a structure makes it imperative to study the effects of lattice vacancies which will inevitably arise during fabrication. We present and compare room temperature performance characteristics for both ideal and disordered double layer graphene systems in an effort to illustrate the behavior of a Bose?Einstein condensate in the presence of lattice defects under non-equilibrium conditions. We find that lattice vacancies spread throughout the top layer past the coherence length have a reduced effect compared to the ideal case. However, vacancies concentrated near the metal contacts within the coherence length significantly alter the interlayer superfluid transport properties.
Positive-Part Moments via the Fourier–Laplace Transform

Integral expressions for positive-part moments \(\mathsf{E}\,X_{+}^{p}\) (p>0) of random variables X are presented, in terms of the Fourier–Laplace or Fourier transforms of the distribution of X. A necessary and sufficient condition for the validity of such an expression is given. This study was motivated by extremal problems in probability and statistics, where one needs to evaluate such positive-part moments.
Multi-way spectral partitioning and higher-order cheeger inequalities

A basic fact in spectral graph theory is that the number of connected components in an undirected graph is equal to the multiplicity of the eigenvalue zero in the Laplacian matrix of the graph. In particular, the graph is disconnected if and only if there are at least two eigenvalues equal to zero. Cheeger's inequality and its variants provide an approximate version of the latter fact; they state that a graph has a sparse cut if and only if there are at least two eigenvalues that are close to zero. It has been conjectured that an analogous characterization holds for higher multiplicities, i.e., there are k eigenvalues close to zero if and only if the vertex set can be partitioned into k subsets, each defining a sparse cut. We resolve this conjecture. Our result provides a theoretical justification for clustering algorithms that use the bottom k eigenvectors to embed the vertices into Rk, and then apply geometric considerations to the embedding. We also show that these techniques yield a nearly optimal quantitative connection between the expansion of sets of size ≈ n/k and λk, the kth smallest eigenvalue of the normalized Laplacian, where n is the number of vertices. In particular, we show that in every graph there are at least k/2 disjoint sets (one of which will have size at most 2n/k), each having expansion at most O(√(λk log k)). Louis, Raghavendra, Tetali, and Vempala have independently proved a slightly weaker version of this last result [LRTV12]. The √(log k) bound is tight, up to constant factors, for the "noisy hypercube" graphs.
Equivariant Pieri Rule for the homology of the affine Grassmannian

An explicit rule is given for the product of the degree two class with an arbitrary Schubert class in the torus-equivariant homology of the affine Grassmannian. In addition a Pieri rule (the Schubert expansion of the product of a special Schubert class with an arbitrary one) is established for the equivariant homology of the affine Grassmannians of SL n and a similar formula is conjectured for Sp 2n and SO 2n+1. For SL n the formula is explicit and positive. By a theorem of Peterson these compute certain products of Schubert classes in the torus-equivariant quantum cohomology of flag varieties. The SL n Pieri rule is used in our recent definition of k-double Schur functions and affine double Schur functions.
The WTO and the Anti-Corruption Movement

This article explores the role of the World Trade Organization (WTO) in promoting good governance while placing WTO within the larger framework of the ongoing global anti-corruption movement. Governmental policies aimed at fighting corruption are part of the good governance criteria set forth by the World Bank and other donor agencies. An important element of good governance is transparency, which has also been one of the pillars of the multilateral trading system. This article argues that from the perspective of the post-Cold War anti-corruption movement, the WTO is an important institution because it provides a comparatively successful forum for the expression and development of good governance values such as transparency. The article first reviews the transparency obligations of the WTO agreements. Second, it reviews the post-cold war anti-corruption movement and its evoluion, and, finally, contrasts WTO's efforts in promoting transparency to the more direct approaches in combatting corruption undertaken by the World Bank.
Stack size analysis for interrupt-driven programs

We study the problem of determining stack boundedness and the exact maximum stack size for three classes of interrupt-driven programs. Interrupt-driven programs are used in many real-time applications that require responsive interrupt handling. In order to ensure responsiveness, programmers often enable interrupt processing in the body of lower-priority interrupt handlers. In such programs a programming error can allow interrupt handlers to be interrupted in a cyclic fashion to lead to an unbounded stack, causing the system to crash. For a restricted class of interrupt-driven programs, we show that there is a polynomial-time procedure to check stack boundedness, while determining the exact maximum stack size is PSPACE-complete. For a larger class of programs, the two problems are both PSPACE-complete, and for the largest class of programs we consider, the two problems are PSPACE-hard and can be solved in exponential time. While the complexities are high, our algorithms are exponential only in the number of handlers, and polynomial in the size of the program.
On the shape of a convex body with respect to its second projection body

We prove results relative to the problem of finding sharp bounds for the affine invariant P ( K ) = V ( ? K ) / V d - 1 ( K ) . Namely, we prove that if K is a 3-dimensional zonoid of volume 1, then its second projection body ? 2 K is contained in 8K, while if K is any symmetric 3-dimensional convex body of volume 1, then ? 2 K contains 6K. Both inclusions are sharp. Consequences of these results include a stronger version of a reverse isoperimetric inequality for 3-dimensional zonoids established by the author in a previous work, a reduction for the 3-dimensional Petty conjecture to another isoperimetric problem and the best known lower bound up to date for P ( K ) in 3 dimensions. As byproduct of our methods, we establish an almost optimal lower bound for high-dimensional bodies of revolution.
Digital pitchforks and virtual torches: Fan responses to the Mass Effect news debacle

In early 2008, what started as a small report in an online conservative outlet on the Xbox 360 videogame Mass Effect was picked up by a number of news outlets and blogs. In particular, Fox News’s ‘Live Desk with Martha MacCallum’ produced a segment on the game, claiming it was fully interactive digital pornography. One of the show’s guests, pop psychologist Cooper Lawrence, argued that the game’s sexual content was harmful, but did so with no firsthand knowledge of the game, incensing fans of the game. Those fans proceeded to respond in various ways, particularly on the internet. The present research examines three distinct areas of these fan responses — forum discussions, YouTube videos, and the ‘review bombing’ of Cooper Lawrence’s books on Amazon.com. The various ways in which fans expressed their anger at, displeasure with, and opinions on the story and how the game was treated in the media present a chance not only to look into the mindset of these fans toward the various institutions involved in but...
Hierarchical Bayesian Modeling of Hitting Performance in Baseball

We have developed a sophisticated statistical model for predicting the hitting performance of Major League baseball players. The Bayesian paradigm provides a principled method for balancing past performance with crucial covari- ates, such as player age and position. We share information across time and across players by using mixture distributions to control shrinkage for improved accuracy. We compare the performance of our model to current sabermetric methods on a held-out season (2006), and discuss both successes and limitations.
Legal Defensibility of Standards: Issues and Policy Perspectives

What legal issues may arise in setting content or performance standards? What precedents are relevant? What practices are defensible?
Bounding dimension of ambient space by density for mean curvature flow

For an ancient solution of the mean curvature flow, we show that each time slice Mt is contained in an affine subspace with dimension bounded in terms of the density and the dimension of the evolving submanifold. Recall that an ancient solution is a family Mt that evolves under mean curvature flow for all negative time t.
Radar observations of Icarus

Abstract Recent radar and optical observations of Icarus indicate that the central latitudes have a smooth surface, whereas the higher latitudes are considerably rougher. According to the data, the radius of Icarus is ⩾490 m, and the radar reflectivity ⩽0.13.
X-RAY INSIGHTS INTO THE NATURE OF WEAK EMISSION-LINE QUASARS AT HIGH REDSHIFT

We present Chandra observations of nine high-redshift quasars (z = 2.7-5.9) discovered by the Sloan Digital Sky Survey with weak or undetectable high-ionization emission lines in their UV spectra (WLQs). Adding archival X-ray observations of six additional sources of this class has enabled us to place the strongest constraints yet on the X-ray properties of this remarkable class of active galactic nuclei (AGNs). Although our data cannot rule out the possibility that the emission lines are overwhelmed by a relativistically boosted continuum, as manifested by BL Lac objects, we find that WLQs are considerably weaker in the X-ray and radio bands than the majority of BL Lacs found at much lower redshifts. If WLQs are high-redshift BL Lacs, then it is difficult to explain the lack of a large parent population of X-ray and radio bright weak-lined sources at high redshift. We also consider the possibility that WLQs are quasars with extreme properties, and in particular that the emission lines are suppressed by high accretion rates. Using joint spectral fitting of the X-ray spectra of 11 WLQs, we find that the mean photon index in the hard X-ray band is consistent with those observed in typical radio-quiet AGNs with no hint of an unusually steep hard-X-ray spectrum. This result poses a challenge to the hypothesis that WLQs have extremely high accretion rates, and we discuss additional observations required to test this idea.
Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL II. Chemical Implications

We present chemical implications arising from spectral models fit to the Herschel/HIFI spectral survey toward the Orion Kleinmann-Low nebula (Orion KL). We focus our discussion on the eight complex organics detected within the HIFI survey utilizing a novel technique to identify those molecules emitting in the hottest gas. In particular, we find the complex nitrogen bearing species CH_3CN, C_2H_3CN, C_2H_5CN, and NH_2CHO systematically trace hotter gas than the oxygen bearing organics CH_3OH, C_2H_5OH, CH_3OCH_3, and CH_3OCHO, which do not contain nitrogen. If these complex species form predominantly on grain surfaces, this may indicate N-bearing organics are more difficult to remove from grain surfaces than O-bearing species. Another possibility is that hot (T_(kin) ~ 300 K) gas phase chemistry naturally produces higher complex cyanide abundances while suppressing the formation of O-bearing complex organics. We compare our derived rotation temperatures and molecular abundances to chemical models, which include gas-phase and grain surface pathways. Abundances for a majority of the detected complex organics can be reproduced over timescales ≳10^5 years, with several species being underpredicted by less than 3σ. Derived rotation temperatures for most organics, furthermore, agree reasonably well with the predicted temperatures at peak abundance. We also find that sulfur bearing molecules that also contain oxygen (i.e., SO, SO_2, and OCS) tend to probe the hottest gas toward Orion KL, indicating the formation pathways for these species are most efficient at high temperatures.
A Novel Risk Stratification to Predict Local-Regional Failures in Urothelial Carcinoma of the Bladder After Radical Cystectomy

Purpose: Local-regional failures (LF) following radical cystectomy (RC) plus pelvic lymph node dissection (PLND) with or without chemotherapy for invasive urothelial bladder carcinoma are more common than previously reported. Adjuvant radiation therapy (RT) could reduce LF but currently has no defined role because of previously reported morbidity. Modern techniques with improved normal tissue sparing have rekindled interest in RT. We assessed the risk of LF and determined those factors that predict recurrence to facilitate patient selection for future adjuvant RT trials. Methods and Materials: From 1990-2008, 442 patients with urothelial bladder carcinoma at University of Pennsylvania were prospectively followed after RC plus PLND with or without chemotherapy with routine pelvic computed tomography (CT) or magnetic resonance imaging (MRI). One hundred thirty (29%) patients received chemotherapy. LF was any pelvic failure detected before or within 3 months of distant failure. Competing risk analyses identified factors predicting increased LF risk. Results: On univariate analysis, pathologic stage {>=}pT3, =}pT3 and =}pT3 and {>=}10 nodes removed), and high-risk ({>=}pT3 and <10 nodes) with 5-year LF rates of 8%, 23%, and 42%, respectively (P<.01). Conclusions: This series using routine CT and MRI surveillance to detect LF confirms that such failures are relatively common in cases of locally advanced disease and provides a rubric based on pathological stage and number of nodes removed that stratifies patients into 3 groups with significantly different LF risks to simplify patient selection for future adjuvant radiation therapy trials.« less
A resistant estimator of multivariate location and dispersion

This paper presents a simple resistant estimator of multivariate location and dispersion. The DD plot is a plot of Mahalanobis distances from the classical estimator versus the distances from a resistant estimator and can be used to detect outliers and as a diagnostic for multivariate normality. The new estimator can be used in the DD plot, is easy to compute and provides insights about several useful robust algorithm techniques.
Application of kernel functions for accurate similarity search in large chemical databases

Similaritysearch in chemical structure databases is an important problem with many applications in chemical genomics, drug design, and efficient chemical probe screening among others. It is widely believed that structure based methods provide an efficient way to do the query. Recently various graph kernel functions have been designed to capture the intrinsic similarity of graphs. Though successful in constructing accurate predictive and classification models, graph kernel functions can not be applied to large chemical compound database due to the high computational complexity and the difficulties in indexing similarity search for large databases. To bridge graph kernel function and similarity search in chemical databases, we applied a novel kernel-based similarity measurement, developed in our team, to measure similarity of graph represented chemicals. In our method, we utilize a hash table to support new graph kernel function definition, efficient storage and fast search. We have applied our method, named G-hash, to large chemical databases. Our results show that the G-hash method achieves state-of-the-art performance for k-nearest neighbor (k-NN) classification. Moreover, the similarity measurement and the index structure is scalable to large chemical databases with smaller indexing size, and faster query processing time as compared to state-of-the-art indexing methods such as Daylight fingerprints, C-tree and GraphGrep. Efficient similarity query processing method for large chemical databases is challenging since we need to balance running time efficiency and similarity search accuracy. Our previous similarity search method, G-hash, provides a new way to perform similarity search in chemical databases. Experimental study validates the utility of G-hash in chemical databases.
On stochastic incentive control problems with partial dynamic information

Abstract In this paper we consider a stochastic incentive decision problem with N > 1 followers and decentralized static information, where the leader's dynamic information comprises only a linear combination of the followers' actions. We obtain an incentive policy, affine in this dynamic information, which yields the same overall performance as the one the leader would obtain if he had observed the followers' actions separately. The existence conditions involved have been obtained explicitly for the case of finite probability spaces, and some challenging issues have been identified when the random variables are infinite valued. The results presented here have no counterparts in deterministic incentive problems.
Amine-catalyzed direct self Diels–Alder reactions of α,β-unsaturated ketones in water: synthesis of pro-chiral cyclohexanones

Amine-catalyzed direct self Diels–Alder reactions of α,β-unsaturated ketones have been developed. (S)-1-(2-Pyrrolidinyl-methyl)pyrrolidine, l-proline and pyrrolidine catalyzed the reaction of α,β-unsaturated ketones to provide cyclohexanone derivatives with good yield (up to 80%) in a single step via in situ-generation of 2-amino-1,3-butadienes and iminium ion-activated enones. Pro-chiral cyclohexanones were selectively prepared with pyrrolidine catalysis in water.
Predictive Behavior within Microbial Genetic Networks

The homeostatic framework has dominated our understanding of cellular physiology. We question whether homeostasis alone adequately explains microbial responses to environmental stimuli, and explore the capacity of intracellular networks for predictive behavior in a fashion similar to metazoan nervous systems. We show that in silico biochemical networks, evolving randomly under precisely defined complex habitats, capture the dynamical, multidimensional structure of diverse environments by forming internal representations that allow prediction of environmental change. We provide evidence for such anticipatory behavior by revealing striking correlations of Escherichia coli transcriptional responses to temperature and oxygen perturbations-precisely mirroring the covariation of these parameters upon transitions between the outside world and the mammalian gastrointestinal tract. We further show that these internal correlations reflect a true associative learning paradigm, because they show rapid decoupling upon exposure to novel environments.
A ‘one pot’ microwave-mediated synthesis of the basic canthine skeleton: expedient access to unnatural β-carboline alkaloids

Abstract In a ‘one pot’ microwave reaction, an acyl hydrazide-tethered indole underwent a 3-component condensation to form a triazine, followed by an inverse-electron demand Diels–Alder reaction and subsequent chelotropic expulsion of N2 to deliver novel, unnatural β-carboline alkaloids in good isolated yields.
Highly enantioselective fluorescent recognition of α-amino acid derivatives

Abstract Bisbinaphthyl-based macrocycles are found to carry out enantioselective fluorescent recognition of α-amino acid derivatives. It is observed that one enantiomer of a N -protected phenyl glycine can increase the fluorescence intensity of the binaphthyl fluorophores by over 4-fold but the other enantiomer does not cause much fluorescence enhancement. This highly enantioselective fluorescent response makes the binaphthyl macrocycles practically useful for the enantioselective fluorescent recognition of the amino acid substrate.
Diastereoselective aldol reactions of chiral aldehydes and chiral methyl ketones: Dependence of stereoselectivity on the metal enolate, the aldehyde 2,3-stereochemistry, and the aldehyde β-alkoxy protecting group

Abstract The stereoselectivity of aldol reactions of chiral aldehydes 5 and 11 with methyl ketone enolates is highly dependent on the aldehyde 2,3-stereochemistry, the aldehyde β-alkoxy protecting group, and the metal enolate. The selectivity trends are rationalized by a competition between chair-like and boat-like transition states.
Stereocontrolled Synthesis of Functionalized cis-Cyclopentapyrazolidines by 1,3-Dipolar Cycloaddition Reactions of Azomethine Imines

The reaction of alkene-tethered α-ketocarboxylic acid derivatives with monosubstituted hydrazines allows highly substituted cis-cyclopentapyrazolidine ring systems 4 to be constructed rapidly. Successful cyclocondensations are realized under thermal reaction conditions; in some cases, protic or Lewis acids accelerate these reactions. α-Methoxy-α,β-unsaturated esters are suitable alkene components, as are alkenes having either electron-withdrawing or electron-donating substituents at the terminal alkene carbon. α-Ketoesters, α-ketoamides, and α-ketothioesters can be employed. Various hydrazines substituted with N-acyl, N-carboalkoxy, or N-carbamothioyl protecting groups are tolerated in these transformations. The rate of intramolecular cycloaddition is found to reflect not only the reactivity and equilibrium concentration of the azomethine imine intermediate, but, also in some cases, the rate at which hydrazone stereoisomers interconvert under the reaction conditions.
On Parameterized Exponential Time Complexity

In this paper, we show that special instances of parameterized NP-hard problems are as difficult as the general instances in terms of their subexponential time computability. For example, we show that the Planar Dominating Set problem on degree-3 graphs can be solved in $2^{o(\sqrt{k})} p(n)$ parameterized time if and only if the general Planar Dominating Set problem can. Apart from their complexity theoretic implications, our results have some interesting algorithmic implications as well.
The effect of adult belt laws and other factors on restraint use for children under age 11

We used data from 11 states (5,449 respondents) to examine the association between self-reported consistent use of occupant restraints for children under 11 years of age and presence of adult belt-use laws while controlling for other factors. Self-reported safety belt use by adults, age of youngest child in the household (child restraint use decreased with increasing age), and adult educational attainment were significant predictors of child restraint use; respondent age, race/ethnicity, sex, marital status, household income, and employment status were not. Adult and child occupant restraint use was higher in states with an adult safety belt law than in states without such a law.
Phosphorus Addition at sp2 Carbon

In recent years a renewed interest in the synthesis of organophosphorus compounds has appeared. This has been the result principally of the development of new applications of materials bearing a carbon–phosphorus linkage for chemical synthesis, biological regulation, and a variety of industrial uses. In chemical syntheses the phosphoryl function has been found to be of great utility as an activator for two major categories of transformations. The first of these is the generation of new carboncarbon double bonds through the phosphoryl-stabilized anion modifications of the Wittig reaction. For these reactions, the phosphoryl function increases the acidity of the hydrogen of the carbon attached to phosphorus and, after addition to a carbonyl linkage, is usually eliminated as a water-soluble byproduct. Alternatively, the initially formed phosphonate anion may be used as a nucleophile in a substitution reaction leading to a derived phosphonate product having its own synthetic utility. In the second category of transformations an appropriately functionalized phosphonate reacts at the carbon attached to phosphorus to give products that can be envisioned as resulting from reaction of an electrophilic substrate with a carbonyl group of inverted polarity. The phosphoryl function, which is generally eliminated in the formation of the target material, facilitates these “umpolung” reactions that could not be accomplished directly with a parent material bearing the simple carbonoxygen double bond. With regard to biological applications, the synthesis of organophosphorus compounds has been of interest for several reasons. Among these is the discovery in a variety of organisms of naturally occurring compounds bearing the carbonphosphorus bond. Phosphonomycin and aminoethylphosphonic acid are two well-known examples of such compounds. It has also been recognized that phosphonates may be capable of perturbing metabolic processes normally involving phosphates of similar structure. In addition, materials with other metabolic regulatory capabilities have been found. As a result, there have been not only syntheses of many new organophosphorus compounds but also the development of improved methods for such syntheses. The review presented in this chapter is concerned with one approach to carbonphosphorus bond formation that is particularly significant for the aforementioned applications, specifically the addition of a (formally) trivalent phosphorus ester or amide to an unsaturated carbon linkage under polar reaction conditions. Reactions of a variety of types of phosphorus reagents with simple carbonyl compounds, imines, and other related polar unsaturated carbon functions, as well as conjugate addition reactions, are reviewed. Keywords: phosphorus; additions; substrate; scope; limitations; sp2 carbon; aldehydes; ketones; phosphorus reagent; method comparisons; phosphonates; conjugate additions; experimental procedures; carbonyl carbon; imine carbon; hydrophosphinylation
Green synthesis of benzo[b]thiophenes via iron(III) mediated 5-endo-dig iodocyclization of 2-alkynylthioanisoles

A reaction of iron(III) chloride with sodium iodide was used to generate iodine for an innovative take on electrophilic cyclization. With ethanol as solvent, the reaction was observed to provide ideal conditions for iodocyclization of 2-alkynylthioanisoles. The fundamental step allows formation of iodine which becomes free to undergo reaction with the starting alkyne to yield the cyclized product. Implementing environmentally benign and simple chemistry, 2-iodosubstituted benzo[b]thiophenes were synthesized in high yields to produce an interesting display of useful molecules.
Single- and Multiple-Shell Uniform Sampling Schemes for Diffusion MRI Using Spherical Codes

In diffusion MRI (dMRI), a good sampling scheme is important for efficient acquisition and robust reconstruction. Diffusion weighted signal is normally acquired on single or multiple shells in q-space. Signal samples are typically distributed uniformly on different shells to make them invariant to the orientation of structures within tissue, or the laboratory coordinate frame. The electrostatic energy minimization (EEM) method, originally proposed for single shell sampling scheme in dMRI, was recently generalized to multi-shell schemes, called generalized EEM (GEEM). GEEM has been successfully used in the human connectome project. However, EEM does not directly address the goal of optimal sampling, i.e., achieving large angular separation between sampling points. In this paper, we propose a more natural formulation, called spherical code (SC), to directly maximize the minimal angle between different samples in single or multiple shells. We consider not only continuous problems to design single or multiple shell sampling schemes, but also discrete problems to uniformly extract sub-sampled schemes from an existing single or multiple shell scheme, and to order samples in an existing scheme. We propose five algorithms to solve the above problems, including an incremental SC (ISC), a sophisticated greedy algorithm called iterative maximum overlap construction (IMOC), an 1-Opt greedy method, a mixed integer linear programming method, and a constrained non-linear optimization method. To our knowledge, this is the first work to use the SC formulation for single or multiple shell sampling schemes in dMRI. Experimental results indicate that SC methods obtain larger angular separation and better rotational invariance than the state-of-the-art EEM and GEEM. The related codes and a tutorial have been released in DMRITool. 1 1 https://diffusionmritool.github.io/tutorial_qspacesampling.html
Robust preference expansions

We propose an approximation method for solving dynamic stochastic general equilibrium models in which agents are concerned about model misspecification. The method relies on a perturbation that treats this robust concern as a first-order concept that is preserved as the volatility of the shocks vanishes. The approximation has a clear economic interpretation and generates solutions with consequences of robust preferences that standard perturbation methods only capture using higher-order terms.
Revenue Maximization with Nonexcludable Goods

We study the design of revenue-maximizing mechanisms for selling nonexcludable public goods. In particular, we study revenue-maximizing mechanisms in Bayesian settings for facility location problems on graphs where no agent can be excluded from using a facility that has been constructed. We show that the pointwise optimization problem involved in implementing the revenue optimal mechanism, namely, optimizing over arbitrary profiles of virtual values, is hard to approximate within a factor of Ω(n2-e) (assuming P≠ NP) even in star graphs. Furthermore, we show that optimizing the expected revenue is APX-hard. However, in a relevant special case, rooted version with identical distributions, we construct polynomial time truthful mechanisms that approximate the optimal expected revenue within a constant factor. We also study the effect of partially mitigating nonexcludability by collecting tolls for using the facilities. We show that such “posted-price” mechanisms obtain significantly higher revenue and often approach the optimal revenue obtainable with full excludability.
A Multinomial Logit Analysis of Teenage Fertility and High School Completion

This paper examines economic, institutional and sociological antecedents of high school completion and adolescent fertility using data on women from the 1979 National Longitudinal Survey of Youth A multinomial logit model is estimated in which the dependent variable represents combinations of high school completion and early fertility outcomes Benefits from various government assistance programs and earnings differences attributable to high school completion are included as potential economic determinants Of these variables, welfare generosity appears to have a significant positive effect on adolescent childbearing. Other variables including family planning clinic availability, family background, religiousness, physical maturity, race and ethnicity are also found to be important determinants of teenage parenthood and educational attainment.
Anatomical frames of reference and biomechanics

For dynamic simulation of human movement, segment axis systems are often defined by the inertial tensor unique to each simulated body segment. When empirical three-dimensional data are sought that ...
Migration and Consumption Insurance in Bangladesh

We investigate the relationship between seasonal migration and informal risk sharing in rural Bangladesh. We use data from a randomized controlled trial which provided incentives for households to migrate (Bryan et al., 2014). Using this experimental variation, we first provide evidence of the effect of decreasing migration costs on endogenous risk sharing in the village. We then investigate the mechanisms of this effect. We undertake a semi-parametric analysis of the source of income shocks, source of insurance and measurement error. Next, we characterize a dynamic model of migration and endogenous risk sharing, incorporating investment in learning about migration possibilities. Estimation of the model is in progress; we plan to analyze the welfare effect of alternative policies to encourage migration, such as access to credit and further reductions in the cost of migrating.