cssi/SciSciGPT-SciSciNet huggingface dataset:
SIS and SIR Epidemic Models Under Virtual Dispersal

We develop a multi-group epidemic framework via virtual dispersal where the risk of infection is a function of the residence time and local environmental risk. This novel approach eliminates the need to define and measure contact rates that are used in the traditional multi-group epidemic models with heterogeneous mixing. We apply this approach to a general n-patch SIS model whose basic reproduction number [Formula: see text] is computed as a function of a patch residence-time matrix [Formula: see text]. Our analysis implies that the resulting n-patch SIS model has robust dynamics when patches are strongly connected: There is a unique globally stable endemic equilibrium when [Formula: see text], while the disease-free equilibrium is globally stable when [Formula: see text]. Our further analysis indicates that the dispersal behavior described by the residence-time matrix [Formula: see text] has profound effects on the disease dynamics at the single patch level with consequences that proper dispersal behavior along with the local environmental risk can either promote or eliminate the endemic in particular patches. Our work highlights the impact of residence-time matrix if the patches are not strongly connected. Our framework can be generalized in other endemic and disease outbreak models. As an illustration, we apply our framework to a two-patch SIR single-outbreak epidemic model where the process of disease invasion is connected to the final epidemic size relationship. We also explore the impact of disease-prevalence-driven decision using a phenomenological modeling approach in order to contrast the role of constant versus state-dependent [Formula: see text] on disease dynamics.
Multi-digit Number Recognition from Street View Imagery using Deep Convolutional Neural Networks

Abstract: Recognizing arbitrary multi-character text in unconstrained natural photographs is a hard problem. In this paper, we address an equally hard sub-problem in this domain viz. recognizing arbitrary multi-digit numbers from Street View imagery. Traditional approaches to solve this problem typically separate out the localization, segmentation, and recognition steps. In this paper we propose a unified approach that integrates these three steps via the use of a deep convolutional neural network that operates directly on the image pixels. We employ the DistBelief implementation of deep neural networks in order to train large, distributed neural networks on high quality images. We find that the performance of this approach increases with the depth of the convolutional network, with the best performance occurring in the deepest architecture we trained, with eleven hidden layers. We evaluate this approach on the publicly available SVHN dataset and achieve over $96\%$ accuracy in recognizing complete street numbers. We show that on a per-digit recognition task, we improve upon the state-of-the-art, achieving $97.84\%$ accuracy. We also evaluate this approach on an even more challenging dataset generated from Street View imagery containing several tens of millions of street number annotations and achieve over $90\%$ accuracy. To further explore the applicability of the proposed system to broader text recognition tasks, we apply it to synthetic distorted text from reCAPTCHA. reCAPTCHA is one of the most secure reverse turing tests that uses distorted text to distinguish humans from bots. We report a $99.8\%$ accuracy on the hardest category of reCAPTCHA. Our evaluations on both tasks indicate that at specific operating thresholds, the performance of the proposed system is comparable to, and in some cases exceeds, that of human operators.
Detecting wave function collapse without prior knowledge

We are concerned with the problem of detecting with high probability whether a wave function has collapsed or not, in the following framework: A quantum system with a d-dimensional Hilbert space is initially in state ψ; with probability 0 < p < 1, the state collapses relative to the orthonormal basis b1, …, bd. That is, the final state ψ′ is random, it is ψ with probability 1 − p and bk (up to a phase) with p times Born’s probability bk|ψ2. Now an experiment on the system in state ψ′ is desired that provides information about whether or not a collapse has occurred. Elsewhere [C. W. Cowan and R. Tumulka, J. Phys. A: Math. Theor. 47, 195303 (2014)], we identify and discuss the optimal experiment in case that ψ is either known or random with a known probability distribution. Here, we present results about the case that no a priori information about ψ is available, while we regard p and b1, …, bd as known. For certain values of p, we show that the set of ψs for which any experiment E is more reliable than bli...
Why don't present-biased agents make commitments?

Since self-control problems were first analyzed by Strotz (1956), researchers have frequently emphasized that dynamically inconsistent preferences, such as present-biased preferences, engender a demand for commitment.1 Here, and throughout this paper, I define commitment as a “pure” restriction on one's choice-set with no confounding extrinsic benefits such as tax deferral in a savings plan or intra-household strategic advantages.2 Commitment is a problematic prediction, since we see so little of it in the economy. Researchers have been able to induce some experimental participants to commit themselves (e.g., Ashraf, Karlan, and Yin 2006), but across a growing literature it is usually the case that only a minority of experimental subjects choose to tie their own hands.3 Moreover, subjects rarely express a willingness to pay a significant price to have their choice-set reduced.4 Most importantly, very little commitment has arisen in the marketplace without the direct involvement of behavioral economists or their students.5 In the current paper, I quantitatively explore the reasons for the “missing” commitment. Extending the present-biased, procrastination model in Carroll et al. (2009), I show how equilibrium commitment is related to (i) the standard deviation of the opportunity cost of time, (ii) the cost of delay, (iii) the degree of partial naivete, and (iv) the direct cost of commitment. My quantitative analysis implies that commitment is not a robust implication of present-biased discounting. Once one calibrates the model, commitment vanishes in many leading cases. In other words, the benefits of commitment (as perceived by the present-biased agent) are frequently overwhelmed by the costs of commitment. This does not imply that we should never expect to see commitment. Rather, in some natural settings (like the one studied here), commitment is a hothouse flower that survives only under special parameterizations. A demand for commitment is a special case rather than the general case. Section I explains the basic model (with sophisticated beliefs) and solves it under the assumption that commitment is not available. Section II introduces a free commitment technology and characterizes the cases under which commitment will be chosen. Section III extends that analysis under the assumption of partial naivete. Section IV completes the analysis by studying the case in which commitment has a direct cost – i.e., a hassle cost or a market price for setting up a commitment contract. Section V concludes. An associated NBER working paper contains proofs.
The Context Interchange Network Prototype

In this paper we describe a prototype implementation of the Context Interchange Network (CIN). The CIN is designed to provide for the intelligent integration of contextually (i.e., semantically) heterogeneous data. The system uses explicit context knowledge and a context mediator to automatically detect conflicts and resolve them through context conversion. The network also allows for context explication; making it possible for a receiver of data to understand the meaning of the information represented by the source data. A financial application is used to illustrate the functionality of the prototype.
A one-pot amidation of primary nitroalkanes

It has been over a half-century since Kornblum demonstrated the conversion of a primary nitroalkane to a carboxylic acid; addition of an amine results in carboxylic acid formation as well. We describe the formation of amides from terminal nitroalkanes in a two-step, one-pot reaction involving tandem halogenation/umpolung amide synthesis (UmAS).
The Limits in Open Code Regulatory Standards and the Future of the Net

This essay considers the effect of the open source software movement on government's ability to regulate the Net. Its claim is that an increase in open source software within the application space of the Internet decreases the government's power to regulate. This is an essay about standards in the future of the Internet's governance. I begin with a distinction between two types of standards, and then continue with a reminder of a bit of history of the evolution of thought about regulation in cyberspace. I then draw upon this distinction and this history to suggest a question about the future of the Net's regulation. This question relates to the place of open source software in the future of the "application space" of the Internet. My argument is that open source software will make regulating cyberspace more difficult than it otherwise would be.
Automated Medical Algorithms: Issues for Medical Errors

The National Patient Safety Foundation has sponsored a report to describe the current research being pursued in the area of medical error reduction and to identify the gaps in this effort.1 A total of 23 gaps were identified—among them was a need for more research in the area of communication and information sharing. One of the areas that we see a need to explore is the wealth of published information in the form of medical algorithms. Centralizing and automating medical algorithms is one way to share information among a wide range of clinical care providers. Furthermore, automation of medical algorithms assists in the correct selection (reducing errors of planning) and application of that information (reducing errors of execution). The …
Structural optimization with aeroelastic constraints: a survey of US applications

The paper describes recent developments in the United States in the application of structural optimization techniques to problems of design under aeroelastic constraints. In particular, the following topics are discussed: (i) conventional–strength design using aeroelastically calculated loads; (ii) aeroelastic tailoring for improved performance; (iii) design under flutter and static aeroelastic constraints; and (iv) miscellaneous applications. Because of the high cost of applying formal optimization techniques to practical design problems, there have been very few applications of structural optimizations to actual aircraft. The paper is focused on trends that may eventually reverse this situation.
Learning Two-input Linear and Nonlinear Analog Functions with a Simple Chemical System

The current biochemical information processing systems behave in a pre-determined manner because all features are defined during the design phase. To make such unconventional computing systems reusable and programmable for biomedical applications, adaptation, learning, and self-modification based on external stimuli would be highly desirable. However, so far, it has been too challenging to implement these in wet chemistries. In this paper we extend the chemical perceptron, a model previously proposed by the authors, to function as an analog instead of a binary system. The new analog asymmetric signal perceptron learns through feedback and supports Michaelis-Menten kinetics. The results show that our perceptron is able to learn linear and nonlinear (quadratic) functions of two inputs. To the best of our knowledge, it is the first simulated chemical system capable of doing so. The small number of species and reactions and their simplicity allows for a mapping to an actual wet implementation using DNA-strand displacement or deoxyribozymes. Our results are an important step toward actual biochemical systems that can learn and adapt.
An Inhibitory Role for the Transcription Factor Stat3 in Controlling IL-4 and Bcl6 Expression in Follicular Helper T Cells

The transcription factor Bcl6 is required for development of follicular helper T (TFH) cells. Cytokines that activate Stat3 promote Bcl6 expression and TFH cell differentiation. Previous studies with an acute virus infection model showed that TFH cell differentiation was decreased but not blocked in the absence of Stat3. In this study, we further analyzed the role of Stat3 in TFH cells. In Peyer's patches, we found that compared with wild-type, Stat3-deficient TFH cells developed at a 25% lower rate and expressed increased IFN-γ and IL-4. Whereas Peyer's patch germinal center B cells developed at normal numbers with Stat3-deficient TFH cells, IgG1 class switching was greatly increased. Following immunization with sheep RBCs, splenic Stat3-deficient TFH cells developed at a slower rate than in control mice, and splenic germinal center B cells were markedly decreased. Stat3-deficient TFH cells developed poorly in a competitive bone marrow chimera environment. Under all conditions tested, Stat3-deficient TFH cells overexpressed both IL-4 and Bcl6, a pattern specific for the TFH cell population. Finally, we found in vitro that repression of IL-4 expression in CD4 T cells by Bcl6 required Stat3 function. Our data indicate that Stat3 can repress the expression of Bcl6 and IL-4 in TFH cells, and that Stat3 regulates the ability of Bcl6 to repress target genes. Overall, we conclude that Stat3 is required to fine-tune the expression of multiple key genes in TFH cells, and that the specific immune environment determines the function of Stat3 in TFH cells.
Empowering women : the effect of women's decision-making power on reproductive health services uptake -- evidence from Pakistan

A large body of research has attempted to explore the links between women's autonomy and their uptake of reproductive health services in the South Asia region, but the evidence so far is inconclusive. This study uses the Pakistan Social and Living Standards Measurement Survey to examine the influence of household decision making on women's uptake of reproductive health services. The analysis finds that women's decision-making power has a significant positive correlation with reproductive health services uptake and that influential males' decision-making power has the opposite effect, after controlling for socio-economic indicators and supply-side conditions. The findings suggest that empowering women and increasing their ability to make decisions may increase their uptake of reproductive health services. They also suggest that policies directed toward improving women's utilization of maternity services must target men as well as women in Pakistan.
From Efficient Symplectic Exponentiation of Matrices to Symplectic Integration of High-dimensional Hamiltonian Systems with Slowly Varying Quadratic Stiff Potentials

We present a multiscale integrator for Hamiltonian systems with slowly varying quadratic stiff potentials that uses coarse timesteps (analogous to what the impulse method uses for constant quadratic stiff potentials). This method is based on the highly-non-trivial introduction of two efficient symplectic schemes for exponentiations of matrices that only require O(n) matrix multiplications operations at each coarse time step for a preset small number n. The proposed integrator is shown to be (i) uniformly convergent on positions; (ii) symplectic in both slow and fast variables; (iii) well adapted to high dimensional systems. Our framework also provides a general method for iteratively exponentiating a slowly varying sequence of (possibly high dimensional) matrices in an efficient way.
Cluster-Cluster Microlensing as a Probe of Intracluster Stars, MACHOs, and Remnants of the First-Generation Stars

An Abell cluster, A2152, was recently found to be forming a cluster-cluster system with another, more distant cluster whose core is almost perfectly aligned with that of A2152. We discuss the detectability of microlensing events where a single star in the source cluster behind A2152 is extremely magnified by an intracluster compact object in A2152. We show that a search with an 8 m class telescope with a wide field of view, such as the Subaru/Suprime-Cam, can probe intracluster compact objects with a wide mass range of mco ~ 10-5 to 1010 M☉, including ranges that have not yet been constrained by any past observations. We expect that the event rate is more biased than the foreground cluster (A2152), which would be a unique signature of microlensing, making this experiment particularly powerful. The sensitivity of this experiment for the mass fraction of compact objects would be 1%-10% in the total dark matter of the cluster, which is roughly constant against mco, with a reasonable telescope time for large telescopes (~10 nights). Therefore, any compact objects in this mass range can be detected or rejected as the dominant component of the dark matter. About 10 events are expected if 20% of the cluster mass is in a form of compact objects with M ~ 1 M☉, as claimed by the MACHO collaboration for the Milky Way halo. Other possibly detectable targets include intracluster stars stripped by galaxy interactions, and hypothetical very massive black holes (M 100 M☉) produced as remnants of the first-generation stars, which might be responsible for the recently reported excess of the cosmic infrared background radiation that seems impossible to explain by normal galactic light.
Higgs mass from compositeness at a multi-TeV scale

Within composite Higgs models based on the top seesaw mechanism, we show that the Higgs field can arise as the pseudo Nambu-Goldstone boson of the broken U(3) L chiral symmetry associated with a vector-like quark and the t-b doublet. As a result, the lightest CP-even neutral state of the composite scalar sector is lighter than the top quark, and can be identified as the newly discovered Higgs boson. Constraints on weak-isospin violation push the chiral symmetry breaking scale above a few TeV, implying that other composite scalars are probably too heavy to be probed at the LHC, but may be within reach at a future hadron collider with center-of-mass energy of about 100 TeV.
Expression of cytoskeletal and matrix genes following exposure to ionizing radiation: Dose-rate effects and protein synthesis requirements

Experiments were designed to examine the effects of radiation dose-rate and of the protein synthesis inhibitor cycloheximide on expression of cytoskeletal elements ({gamma}- and {beta}-actin and {alpha}-tubulin) and matrix elements (fibronectin) in Syrian hamster embryo cells. Past work from our laboratory had already demonstrated optimum time points and doses for examination of radiation effects on accumulation of specific transcripts. Our results here demonstrated little effect of dose-rate for JANUS fission spectrum neutrons when comparing expression of either {alpha}-tubulin or fibronectin genes. Past work had already documented similar results for expression of actin transcripts. Effects of cycloheximide, however, revealed several interesting and novel findings: (1) Cycloheximide repressed accumulation of {alpha}-tubulin following exposure to high dose-rate neutrons or {gamma} rays; this did not occur following similar low dose-rate exposure (2) Cycloheximide did not affect accumulation of mRNA for actin genes. Cycloheximide abrogated the moderate induction of fibronectin-mRNA which occurred following exposure to {gamma} rays and high dose-rate neutrons. These results suggest a role for labile proteins in the maintenance of {alpha}-tubulin and fibronectin mRNA accumulation following exposure to ionizing radiation. In addition, they suggest that the cellular/molecular response to low dose-rate neutrons may be different from the response to high dose-rate neutrons.
Enantioselective Conjugate Addition of Hydrazines to α,β-Unsaturated Imides. Synthesis of Chiral Pyrazolidinones

This manuscript describes a highly enantioselective conjugate hydrazine addition to α,β-unsaturated imides. The achiral template used has a significant impact on product enantioselectivity. Reactions at lower temperatures provide a protocol to add substituted hydrazines with selectivity resulting in the formation of a single pyrazolidinone product (>98:2 selectivity). A variety of chiral pyrazolidinones with potential as chiral auxiliaries and ligands are accessible through the new conjugate addition methodology.
Simple and Efficient Synthesis of 4,7‐Dimethoxy‐1(H)‐indene

Abstract Stirring 4,7‐dimethoxy‐1‐indanol in chloroform at room temperature in the presence of a catalytic amount of p‐toluenesulfonic acid gave 4,7‐dimethoxy‐1(H)‐indene in quantitative yield. Other solvents, including benzene, which was the most frequently used one for this reaction, gave mostly polymeric materials. The new method was also effective for dehydration of other electron‐rich benzylic alcohols.
Relations between Average-Case and Worst-Case Complexity

The consequences of the worst-case assumption NP=P are very well understood. On the other hand, we only know a few consequences of the analogous average-case assumption “NP is easy on average.” In this paper we establish several new results on the worst-case complexity of Arthur-Merlin games (the class AM) under the average-case complexity assumption “NP is easy on average.” We first consider a stronger notion of “NP is easy on average” namely NP is easy on average with respect to distributions that are computable by polynomial size circuit families. Under this assumption we show that AM can be derandomized to nondeterministic subexponential time. Under the assumption that NP is easy on average with respect to polynomial-time computable distributions, we show (a) AME=E where AME is the exponential version of AM. This improves an earlier known result that if NP is easy on average then NE=E. (b) For every c>0, $\mathrm{AM}\subseteq [\mbox{\small io-pseudo}_{\mathrm{NTIME}(n^{c})}]\mathrm{-}\mathrm{NP}$. Roughly this means that for any language L in AM there is a language L′ in NP so that it is computationally infeasible to distinguish L from L′. We use recent results from the area of derandomization for establishing our results.
The nature of the Moon's surface: evidence from shock metamorphism in Apollo 11 and 12 samples

Abstract Evidence of shock effects resulting from impact induced pressures (hundreds of kilobars range) and temperatures occurs in varying abundance in the lunar soil and microbreccias collected around the Apollo 11 site. These effects include: (1) multiple sets of planar features in silica phase(s) and plagioclase, (2) planar features (?), shock induced twin or deformation lamellae, and kink bands in clinopyroxenes, (3) thetomorphic plagioclase glass (maskelynite) in crystalline rock fragments within the breccias, (4) isotropization or partial decomposition of clinopyroxenes leading to anomalously low refractive indices with respect to initial compositions, (5) partial fusion of mineral and rock fragments; heterogeneous glasses; glass spherules (some with NiFe inclusions) of both mineral and rock compositions, (6) variable loss of Na and Ca in shocked feldspar samples, and (7) quench crystals in shock melted glasses and extensive recrystallization of these and thetomorphic glass phases. The three Apollo 12 samples thus far examined show less diversity of shock effects and the average intensity of shock damage is reduced. Planar featuers were not found and the number of glass spherules per unit volume has apparently decreased. These observations suggest that the regolith at the 12 site is younger and thus has been subjected to fewer impacts, which also accounts for its lesser apparent thickness compared with the 11 site. Microbreccias at both sites appear to derive by shock lithification of the lunar soil to produce a variably cohesive, in places glass cemented rock. Within both soil and microbreccias, rare fragments consisting mainly of anorthite-rich (An 85–95 ) feldspar crystals may be microanorthosites introduced from nearby sources or from more distant highlands areas. Some of these fragments appear to be microanorthosite masses granulated by shock into coherent aggregates. Several, however, seemingly consist of once loose feldspar grains which had comprised a regolithic layer originated from impact comminution of anorthosite hardrock units probably located in the lunar highlands that was then shock lithified during later impacts and ejected to the 11 and 12 sites. Implications of shock metamorphism in these lunar materials relative to the origin of the Moon's circular structures, the regolith on the maria, and the microbreccias, respectively, are considered mainly from the viewpoint of Apollo 11 data.
History as Commodity: In Some Recent American (Anthropological) Literature

Discussion critique des etudes de S. Mintz et de E. Wolf, de leurs conceptions de l'histoire| problematique du processus de substitution de la valeur d'echange a la valeur d'usage et de l'objectivation du monde a travers l'extension du consumerisme
Synthesis and Anticancer Activity of Sclerophytin-Inspired Hydroisobenzofurans

Abstract Three structurally related sets of hydroisobenzofuran analogs of sclerophytin A were prepared in three or four steps from ( S )-(+)-carvone via an aldol-cycloaldol sequence. The most potent members of each set of analogs exhibited IC 50 ’s of 1–3 μM in growth inhibitory assays against KB3 cells. The NCI 60-cell line 5-dose assay for analog 6h revealed a GI 50 = 0.148 μM and LC 50 = 9.36 μM for the RPMI-8226 leukemia cell line, and a GI 50 = 0.552 μM and LC 50 = 26.8 μM for the HOP-92 non-small cell lung cancer cell line.
Electrification of wind-blown sand on Mars and its implications for atmospheric chemistry

[1] Wind-blown sand, or ‘saltation,’ creates sand dunes, erodes geological features, and could be a significant source of dust aerosols on Mars. Moreover, the electrification of sand and dust in saltation, dust storms, and dust devils could produce electric discharges and affect atmospheric chemistry. We present the first calculations of electric fields in martian saltation, using a numerical model of saltation that includes sand electrification, plasma physics, and the adsorption of ions and electrons onto particulates. Our results indicate that electric discharges do not occur in martian saltation. Moreover, we find that the production of hydrogen peroxide and the dissociation of methane by electric fields are less significant than previously thought. Both these species are highly relevant to studies of past and present life on Mars.
On the Violence of High Explosive Reactions

High explosive reactions can be caused by three general energy deposition processes: impact ignition by frictional and/or shear heating; bulk thermal heating; and shock compression. The violence of the subsequent reaction varies from benign slow combustion to catastrophic detonation of the entire charge. The degree of violence depends on many variables, including the rate of energy delivery, the physical and chemical properties of the explosive, and the strength of the confinement surrounding the explosive charge. The current state of experimental and computer-modeling research on the violence of impact, thermal, and shock-induced reactions is briefly reviewed in this paper.
Distributional Limits for the Symmetric Exclusion Process

Abstract Strong negative dependence properties have recently been proved for the symmetric exclusion process. In this paper, we apply these results to prove convergence to the Poisson and Gaussian distributions for various functionals of the process.
Toward Integration: Disciplines, Specialties and Journals

Specialization is the way to start a discipline, but it must not become a religion. When rigid, it is an impediment to advancing knowledge: the more rigidly specialized, the less relevant to advancing knowledge. Currently this rigidity seems to be the key problem in social and behavioral studies and in the humanities as well. For example, it seems clear that complete adherence to what psychologists think of as the scientific method has brought the discipline to a virtual standstill. Two examples: “aggression catharsis” and self-esteem. For many years psychologists have been conducting experiments that show that venting anger doesn’t work. This is an extremely important finding because the majority of the public thinks that venting is a good idea: it gets the anger “off your chest.” However, the researchers made the appalling error of confounding venting with catharsis. Being scientistic allows them to ignore the large literature in the humanities that has developed a complex model of catharsis. According to this model, venting is not a form of catharsis. Arousing anger in a theatre audience is meant to let them feel suppressed emotions safely, not cause a riot. The second example is the study of self-esteem. Over the last 50 years there have been more than 20,000 studies using self-esteem scales and other reliable methods, such as systematic social surveys. Yet these scales refuse to predict behavior: the variance has always been under 5 %, practically zero. One of the problems with the some 200 different scales that have been used may concern their validity, rather than their reliability: the scales all confound thoughts (such as egotism) with emotions (such as authentic pride.)
Diamond milling of micro-optics

A diamond mill (a tiny end mill) can cut aspheric lenses and mirrors with diameters smaller than 0.5 mm. The cutting tool has a two-dimensional shape and is spun about the axis of the surface to be cut. As the spinning tool is plunged into the substrate, it cuts a radially symmetric surface to sub-micron accuracies. Commercially available circular diamond tools can be modified to aspheric shapes using a focused ion beam. Fabrication examples will be presented and the optical performance of an array of micro-lenses will be described.
Prediction of high T(c) superconductivity in hole-doped LiBC.

The layered lithium borocarbide LiBC, isovalent with and structurally similar to the superconductor ${\mathrm{MgB}}_{2}$, is an insulator due to the modulation within the hexagonal layers (BC vs ${\mathrm{B}}_{2}$). We show that hole doping of LiBC results in Fermi surfaces of B-C $p\ensuremath{\sigma}$ character that couple very strongly to B-C bond stretching modes, precisely the features that lead to superconductivity at ${T}_{c}\ensuremath{\simeq}40\mathrm{K}$ in ${\mathrm{MgB}}_{2}$. Comparison of ${\mathrm{Li}}_{0.5}\mathrm{BC}$ with ${\mathrm{MgB}}_{2}$ indicates the former to be a prime candidate for electron-phonon coupled superconductivity at substantially higher temperature than in ${\mathrm{MgB}}_{2}$.
Total Synthesis of FR901464, an Antitumor Agent that Regulates the Transcription of Oncogenes and Tumor Suppressor Genes

FR901464 is a potent anticancer agent that regulates the transcription of oncogenes and tumor suppressor genes. A convergent enantioselective synthesis of FR901464 was accomplished in 13 linear steps. Central to the synthetic approach was the diene-ene cross olefin metathesis reaction to generate the C6−C7 olefin, without the use of protecting groups, as the final coupling. Additional key reactions include a Zr/Ag-promoted alkynylation to set the C4 stereocenter, a mild and chemoselective Red-Al reduction, a stereoselective Mislow−Evans-type [2,3]-sigmatropic rearrangement to install the C5 stereocenter, a Carreira asymmetric alkynylation to generate the C4‘ stereocenter, and a highly efficient ring-closing metathesis−allylic oxidation sequence to form an unsaturated lactone.
The Gravitational Pull of Race on the Warren Court

My thesis in this article is that concern over racial injustice and state institutional failure was so intense during the twenty-one, “Warren years,” from 1952-1973 that it played a significant role in shaping many of the most important constitutional decisions of the Supreme Court in areas as diverse as federalism, separation of powers, criminal law and procedure, freedom of speech, association, and religion, procedural due process of law, and democracy. I believe, as well, that at least some of the changes in constitutional doctrine that have taken place in the post-Warren era, such as the erosion of the exclusionary rule, the rebalancing of federal-state power, and the easing of restrictions on aid to parochial schools, reflect both a decrease in the intensity of the Court’s concern over racial injustice, and an increase in the legal system’s confidence in state and local institutions to act fairly in racially-charged settings. I begin with a summary of selected aspects of Warren Court constitutional doctrine having nothing directly to do with race, arguing that the Justices’ concerns over racial injustice and regional failure to deal fairly with race exercised a gravitational pull on the evolution of constitutional doctrine. I then turn briefly to whether such a gravitational pull should be cause for celebration, condemnation, or a shrug of the shoulders. Finally, I ask why, once the gravitational pull of race had ebbed, certain Warren Court constitutional precedents that appear to owe their genesis, at least in part, to concern over racial injustice and regional failure have flourished, while others have melted away.
The periods of Neptune: Evidence for atmospheric motions

Abstract An extended photometric time series in the J and K bands of Neptune has a complex appearance which appears to require the simultaneous presence of three periodicities plus related harmonics in the ( J - K ) color. The most apparent of the fundamental periods is N1 = 17.73 hr. The two others are at N2 = 18.56 and N3 = 18.29 hr and may be the result of amplitude modulation of a previously reported period of 18.42 hr. We interpret the presence of multiple periodicity as indicating that distinct systems of zonal winds exist on the planet. We argue that these wind systems are probably confined to moderate or high latitudes on the basis of recent omages of the planet taken in a spectral region of strong CH 4 absorption, and, by analogy to the zonal wind systems that exist in Jupiter's atmosphere, deduce a period of rotation for the body of the planet of 18.2 ± 0.4 hr. Zonal wind contrasts of up to 109 m sec −1 are implied in the atmosphere of Neptune by these observations.
dS/CFT correspondence in two dimensions

Abstract We discuss the quantization of a scalar particle moving in two-dimensional de Sitter space. We construct the conformal quantum mechanical model on the asymptotic boundary of de Sitter space in the infinite past. We obtain explicit expressions for the generators of the conformal group and calculate the eigenvalues of the Hamiltonian. We also show that two-point correlators are in agreement with the Green function one obtains from the wave equation in the bulk de Sitter space.
Holomorphic anomalies and the nonrenormalization theorem

Abstract It has been argued that the superpotential can be renormalized in the presence of massless particles. Possible implications which have been considered include the restoration of supersymmetry at higher loops or a shift to a supersymmetric vacuum state. We argue that even in the presence of massless particles, there are no new contributions to the superpotential at any order in perturbation theory. This confirms the utility of the Wilsonian superpotential for analyzing the moduli space of the low energy theory.
The functionalization of saturated hydrocarbons. Part 24. The use of tert-butyl hydroperoxide: GoAggIV and GoAggV.

Abstract The use of tert -butyl hydroperoxide as an oxidant in Gif-type systems (GoAgg IV and GoAgf V ) catalyzed by various Fe(III) species is examined. Regioselectivity studids of these systems have revealed several characteristics similar to those observed for other prdviously reported Gif-type reactions. A common rdaction pathway for the GoAgg IV and GoAgg V oxidation systems and other Gif-type reactions (from alkane via alkyl hydroperoxide to ketone or alcohol) is seen.
Evaluation of Prostate Size: A Comparison of Ultrasound and Magnetic Resonance Imaging

To determine the relative accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in the evaluation of prostate volume, we compared US and MR images with surgical findings in 15 patients. Transabdominal US was excellent for determining prostate size in patients with small to moderate enlargement. When compared with surgical specimens, the difference between the weight of the gland as predicted by US and the actual weight was 14% (SD +/- 12). With the transabdominal approach, the length was often inaccurately imaged, but the addition of transrectal scans in the sagittal projection improved results: with combined transabdominal and transrectal US, the average difference in weight was 8% (SD +/- 7). The MRI more accurately predicted prostatic volume (average difference, 6% (SD +/- 6), but the difference between the latter 2 is not significant. In 5 additional patients who had undergone transurethral resection of the prostate, residual prostatic tissue was evaluated by MRI and US. In addition to demonstrating prostate size, transrectal sagittal US showed the relationship among the bladder neck, prostatic urethra, and remaining prostatic tissue. Real-time US also allowed evaluation of dynamic sphincteric contractions, which is a finding not available today with MRI. Tissue differentiation was attempted with both MRI and US. Neither imaging modality could differentiate benign from malignant disease.
Evaluating asset-pricing models using the Hansen-Jagannathan bound: A Monte Carlo investigation

We conduct Monte Carlo experiments to examine whether the bound proposed by Hansen and Jagannathan (1991) is a useful device for evaluating asset pricing models. Specifically, we use recently developed statistical tests, which are based on a 'distance' between the model and the Hansen-Jagannathan bound, to compute the rejection rates of true models. We provide finite-sample critical values for asset pricing models with time separable preferences, and show how they depend upon nuisance parametersrisk aversion and the rate of time preference. Further, we show that the finite-sample distribution of the test statistic associated with the risk-neutral case is extreme, in the sense that critical values based on this distribution will deliver type I errors no larger than intendedregardless of risk aversion or the rate of time preference. Extending the analysis to accommodate other preferences, we show that in the state non-separable case, the small-sample distributions of the test statistics are influenced significantly by the degree of intertemporal substitution, but not by attitudes toward risk. For habit formation preferences, the small-sample distributions are strongly influenced by the habit parameter. However, the maximal-size critical values for time-separable preferences are appropriate for habit formation as well as state non-separable preferences. We conclude that with these critical values the HJ bound is indeed a useful evaluation device. We then use the critical values to evaluate three asset pricing models using U.S. data. We find evidence against the time-separable model and mixed evidence on the remaining two models.
Effect of texture and stress on acoustic birefringence

Abstract Results presented here conclusively demostrate the effect of texture, and stress on acoustic birefringence and are in agreement with theoretical formulations of Hughes and Kelley and Biot. Both these factors, i.e., stress and texture produce a shift in the ultrasonic velocities but the change in shear wave velocity due to stress alone is independent of frequency.
Axial Ratios and Orientations for 100 Galactic Globular Star Clusters

The non-spherical appearance of globular clusters was first noted by Pease and Shapley (1917) and discussed in some detail by Shapley (1930) who analyzed cluster shapes determined from star counts made by Helen Sawyer on the Franklin-Adams star charts. This classic work has provided most of the data set used in all subsequent discussions of cluster shapes. A number of studies reporting cluster shapes have appeared in the years since we began this project, the most recent of which include Geyer, Hopp and Nelles (1983), Frenk and Fall (1982), and Kadla et al. (1976, 1977).
Synthesis of novel hypotensive aromatic thiocarbamate glycosides

Syntheses of hypotensive thiocarbamate glycosides from Moringa oleifera are described. The route involves, first, the condensation of the sugar moiety with p-hydroxybenzonitrile to give glycoside 2, then subsequent reduction of 2 to the glycosidic benzylamine 3, which is then converted into isothiocyanate 6. Finally, alcoholysis of 6 gives the desired thiocarbamate glycosides.
The Frequency of Polarized Broad Emission Lines in Type 2 Seyfert Galaxies

We have discovered polarized broad emission lines in five type 2 Seyfert galaxies (NGC 424, NGC 591, NGC 2273, NGC 3081, and NGC 4507), establishing that these objects are type 1 Seyferts obscured by dense circumnuclear material. The galaxies are part of a distance-limited sample of 31 Seyfert 2s, for which spectropolarimetric observations are now complete. Combined with published reports, our results indicate that at least 11 of the galaxies in this sample, or ≥35%, possess hidden broad-line regions. As the first reliable estimate of the frequency of polarized broad emission lines in type 2 Seyfert galaxies, this has important implications for the general applicability of Seyfert unification models.
Stereochemical Factors in Epoxide Polymerization by Base and Coordination Catalysts

Abstract The amorphous fraction accompanying isotactic poly (propy-lene oxide) or poly(tert-butylethylene oxide) formed by co-ordination catalysts was shown by degradation to the dimer glycols to involve inversion of configuration at every ring opening at the secondary carbon atom for (R) - [or (S) -] PO and to involve no stereoselection in the coordination step for tert-BuEO. The crystalline poly(tert-BuEO) formed by polymerization with tert-BuOK was similarly shown to give equal amounts of erythro and threo dimer glycol. It is proposed that these dimer units arise from regular alternate isotactic and syndiotactic placements (iso,syn). Aryl glycidyl
Multiple buoyancy driven flows in a vertical cylinder heated from below

The structure of axisymmetric buoyancy-driven convection in a vertical cylinder heated from below is probed by finite element solution of the Boussinesq equations coupled with computed-implemented perturbation techniques for detecting and tracking multiple flows and for determining flow stability. Results are reported for fluids with Prandtl number of one and for cylinders with aspect ratio (Lambda) (defined as the height to radius of the cylinder) between 0.5 and 2.25. Extensive calculations of the neutral stability curve for the static solution and of the nonlinear motions along the bifurcating flow families show a continuous evolution of the primary cellular motion from a single toroidal cell to two and three cells nested radially in the cylinder, instead of the sharp transitions found for a cylinder with shear-free sidewalls. The smooth transitions in flow structure with Rayleigh number and lambda are explained by nonlinear connectivity between the first two bifurcating flow families formed either by a secondary bifurcation point for Lambda or = Lambda * approximately 0.80 or by a limit point for Lambda Lambda *. The transition between these two modes may be described by the theory of multiple limit point bifurcation.
Patterns in plant parthenogenesis

Several recent reviews have described the ecological and geographical patterns of parthenogenesis in animals (Bell, 1982; Glesener and Tilman, 1978) in an effort to determine which selective forces best explain the maintenance of sexual reproduction. These reviews conclude that parthenogenetic lineages tend to be found at higher latitudes, at higher elevations, in more xeric conditions, in more disturbed habitats, and on more island-like habitats than their sexual relatives. In general, it is argued that asexual taxa are more widely distributed than are their sexual relatives, with sexuals limited to habitats in which the important selective forces are principally biotic rather than physical.
GLAST: a detector for high-energy gamma rays

The gamma-ray large area space telescope (GLAST) is a proposed next-generation high-energy gamma-ray telescope for studying emission from astrophysical sources in the 10 MeV to 300 GeV energy range. GLAST is currently under study as a NASA new mission concept in astrophysics. The primary scientific targets for the GLAST mission include active galactic nuclei, gamma-ray bursts, neutron stars, and the diffuse galactic and extragalactic high-energy radiation. GLAST relies on the unambiguous identification of incident gamma-rays by detection of the electron and positron that result from pair creation in a thin converter material. Measurement of the energy and direction of the electron- positron pair shower provides information about the energy and direction of the incident gamma-ray. The GLAST design utilizes modern solid-state particle detector technology and recently developed space-qualified computers. Because of the technical approach, the telescope design can be easily optimized to a range of sizes. For example, accommodation of GLAST within a Delta II size launch system results in an instrument with capabilities well beyond those of the highly successful EGRET currently operating on the Compton Observatory; namely, a broader energy range, larger effective area, wider field of view, and single-photon angular resolution 2 to 5 times more precise than EGRET's resolution. GLAST will have an effective area of 8000 cm2 above 300 MeV, a field of view of 2.6 sr, and single photon angular resolution (rms projected) of 0.3 degrees at 1 GeV, approaching 0.03 degrees above 20 GeV.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Offset of latest pleistocene shoreface reveals slip rate on the Hosgri strike-slip fault, offshore central California

Abstract The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265 m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6±0.9 mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults. Online Material: (1) High‐resolution bathymetric data for the cross‐Hosgri slope and (2) metadata that describes data collection, processing, and formatting.