cssi/SciSciGPT-SciSciNet huggingface dataset:
Loop Quantum Cosmology: A Status Report

Loop quantum cosmology (LQC) is the result of applying principles of loop quantum gravity (LQG) to cosmological settings. The distinguishing feature of LQC is the prominent role played by the quantum geometry effects of LQG. In particular, quantum geometry creates a brand new repulsive force which is totally negligible at low spacetime curvature but rises very rapidly in the Planck regime, overwhelming the classical gravitational attraction. In cosmological models, while Einstein's equations hold to an excellent degree of approximation at low curvature, they undergo major modifications in the Planck regime: for matter satisfying the usual energy conditions, any time a curvature invariant grows to the Planck scale, quantum geometry effects dilute it, thereby resolving singularities of general relativity. Quantum geometry corrections become more sophisticated as the models become richer. In particular, in anisotropic models, there are significant changes in the dynamics of shear potentials which tame their singular behavior in striking contrast to older results on anisotropies in bouncing models. Once singularities are resolved, the conceptual paradigm of cosmology changes and one has to revisit many of the standard issues—e.g. the 'horizon problem'—from a new perspective. Such conceptual issues as well as potential observational consequences of the new Planck scale physics are being explored, especially within the inflationary paradigm. These considerations have given rise to a burst of activity in LQC in recent years, with contributions from quantum gravity experts, mathematical physicists and cosmologists. The goal of this review is to provide an overview of the current state of the art in LQC for three sets of audiences: young researchers interested in entering this area; the quantum gravity community in general and cosmologists who wish to apply LQC to probe modifications in the standard paradigm of the early universe. In this review, effort has been made to streamline the material so that each of these communities can read only the sections they are most interested in, without loss of continuity.
Scaling of phononic transport with connectivity in amorphous solids

The effect of coordination on transport is investigated theoretically using random networks of springs as model systems. An effective medium approximation is made to compute the density of states of the vibrational modes, their energy diffusivity (a spectral measure of transport) and their spatial correlations as the network coordination z is varied. Critical behaviors are obtained as z→zc where these networks lose rigidity. A sharp crossover from a regime where modes are plane-wave–like toward a regime of extended but strongly scattered modes occurs at some frequency ω*~z-zc, which does not correspond to the Ioffe-Regel criterion. Above ω* both the density of states and the diffusivity are nearly constant. These results agree remarkably with recent numerical observations of repulsive particles near the jamming threshold (Xu N. et al., Phys. Rev. Lett., 102 (2009) 038001). The analysis further predicts that the length scale characterizing the correlation of displacements of the scattered modes decays as with frequency, whereas for ωω* Rayleigh scattering is found with a scattering length ls~(z-zc)3/ω4. It is argued that this description applies to silica glass where it compares well with thermal conductivity data, and to transverse ultrasound propagation in granular matter.
Heat Transfer Regimes in Nuclear-Reactor-Pumped Gas Lasers

The flow induced in nuclear-reactor-pumped gas lasers by spatially nonuniform fission-fragment heating and by heat transfer to the walls is examined. The equations of motion are acoustically filtered, and the resulting equations have three time scales: the heating duration, the time over which an 0 (1) pressure rise is produced, and the thermal boundary-layer growth time. Three distinct regimes emerge from consideration of the relative magnitudes of these tune scales. In the negligible-condition regime, heating nonuniformity determines the motion. In the dominant-conduction regime, thermal-conduction effects govern the motion. In the mixed regime, both effects are comparable but oppositely directed, producing a complex motion. Analytical solutions for the motion and for d2p/dx2 (used in optical analyses) are presented for the first two regimes, and numerical examples are given for all three.
Satiation from sensory simulation: Evaluating foods decreases enjoyment of similar foods

Abstract We demonstrate in two studies that people get more satiated on a food after repeatedly rating or choosing among similar foods shown in pictures. Repeated evaluations of food apparently have an effect similar to actual consumption—decreased enjoyment of foods that share a similar taste characteristic (i.e., sensory-specific satiety). We provide mediation evidence to show that satiation manifests because considering a food engenders spontaneous simulations of the taste of that food item, which by itself is enough to produce satiation. These findings establish sensory simulations as an important mechanism underlying satiation, and provide behavioral evidence that simple evaluations can produce sensory-specific satiety.
New Strategies for Organic Catalysis: The First Enantioselective Organocatalytic 1,3-Dipolar Cycloaddition

Our laboratory has been engaged in the design of broadly useful new strategies for enantioselective catalysis that utilize organic chemicals as reaction catalysts. In our recent study, we reported that the LUMO-lowering activation of α,β-unsaturated aldehydes using the reversible formation of iminium ions with chiral imidazolidinones 1 (eq 1) is a valuable platform for the development of enantioselective organocatalytic Diels−Alder reactions (eq 2). In this work, we reveal that this catalytic strategy is also amenable to [3 + 2] cycloadditions between nitrones and α,β-unsaturated aldehydes to provide isoxazolidines (eq 3), useful synthons for the construction of biologically important amino acids, β-lactams, amino carbohydrates, and alkaloids. To our knowledge, this is the first example of an organocatalytic 1,3-dipolar cycloaddition. Moreover, this study further documents that chiral amines can be employed as asymmetric catalysts for a range of transformations that traditionally utilize metal salts.
The Healthy Aging Brain Care (HABC) Monitor: validation of the Patient Self-Report Version of the clinical tool designed to measure and monitor cognitive, functional, and psychological health

Background Primary care providers need an inexpensive, simple, user-friendly, easily standardized, sensitive to change, and widely available multidomain instrument to measure the cognitive, functional, and psychological symptoms of patients suffering from multiple chronic conditions. We previously validated the Caregiver Report Version of the Healthy Aging Brain Care Monitor (HABC Monitor) for measuring and monitoring the severity of symptoms through caregiver reports. The purpose of this study was to assess the reliability and validity of the Patient Self-Report Version of the HABC Monitor (Self-Report HABC Monitor). Design Cross-sectional study. Setting Primary care clinics affiliated with a safety net urban health care system in Indianapolis, Indiana, USA. Subjects A total of 291 subjects aged ≥65 years with a mean age of 72.7 (standard deviation 6.2) years, 76% female, and 56% African Americans. Analysis Psychometric validity and reliability of the Self-Report HABC Monitor. Results Among 291 patients analyzed, the Self-Report HABC Monitor demonstrated excellent fit for the confirmatory factor analysis model (root mean square error of approximation =0.030, comparative fit index =0.974, weighted root mean square residual =0.837) and good internal consistency (0.78-0.92). Adequate convergent-divergent validity (differences between the Telephone Interview for Cognitive Status test-based cognitive function impairment versus nonimpairment groups) was demonstrated only when patients were removed from analysis if they had both cognitive function test impairment and suspiciously perfect self-report HABC Monitor cognitive floor scores of 0. Conclusion The Self-Report HABC Monitor demonstrates good reliability and validity as a clinically practical multidimensional tool for measuring symptoms. The tool can be used along with its caregiver version to provide useful feedback (via monitoring of symptoms) for modifying care plans. Determining the validity of HABC Monitor scores from patients who self-report a perfect cognitive score of 0 requires cognitive function test results (eg, Telephone Interview for Cognitive Status or Mini Mental State Examination) or Caregiver Report HABC Monitor scores or further clinical examination to rule out the possibility that the patient is denying or unaware of their cognitive symptoms.
Annulation of thioimidates and vinyl carbodiimides to prepare 2-aminopyrimidines, competent nucleophiles for intramolecular alkyne hydroamination. Synthesis of (-)-crambidine.

A convergent synthesis of (−)-crambidine is reported. The sequence capitalizes on two novel key transformations, including a [4+2] annulation of thioimidates with vinyl carbodiimides and an alkyne hydroamination employing 2-aminopyrimidine nucleophiles.
Patterns of failure in differentiated carcinoma of the thyroid based on risk groups

Background Risk-group stratification based on prognostic factors is well established in differentiated carcinoma of the thyroid gland. Patients in the low-risk group have an excellent prognosis, whereas there is significant mortality associated with the high-risk group. The purpose of this paper is to analyze the patterns of treatment failure in the various (local, regional, distant, and associated mortality) risk groups. Methods In a retrospective review of a consecutive series of 1038 previously untreated patients with differentiated carcinoma of the thyroid during a period of 55 years, various prognostic factors and risk groups were analyzed. Significant prognostic factors were patient's age, presence of distant metastasis, extrathyroid extension, size, and grade of the tumor. Based on these factors, patients were divided into low- (39%), intermediate- (39%), and high- (22%) risk groups. Results The overall treatment-failure rates in the low-, intermediate-, and high-risk groups were 13%, 26%, and 50%, respectively, whereas the mortality rates in the same groups were 1%, 10%, and 33%, respectively. Conclusions The overall incidence of recurrence rate in the low-risk group is only 13%, compared with 50% in the high-risk group. The incidence of distant metastasis in the low-risk group is only 2%, compared with 34% in the high-risk group. The understanding of the patterns of treatment failure in different risk groups reaffirms the need to direct treatment strategies based on individual risk groups and intraoperative findings. © 1998 John Wiley & Sons, Inc. Head Neck20: 26–30, 1998.
Chemistry of baker's yeast reduction products: Use of optically active (S)-(+)-1-(p-toluenesulfonyl)propan-2-ol and (S)-(+)-1-(phenylsulfonyl)propan-2-ol in synthesis.

Abstract The utility of the title compounds in the preparation of optically active lactones and alcohols is detailed.
Broadband excitation and active control of terahertz plasmons in graphene

A novel broadband technique to effectively launch plasmons along a single graphene layer at terahertz (THz) frequencies is proposed. To this end, the coupling of the electromagnetic wave from a readily available plasmonic waveguide established by a periodically corrugated metallic surface to the graphene sheet is proposed. As will be shown, this technique can significantly surmount the need for efficient excitation of plasmons in graphene. For this purpose, an analytical technique based on transmission line theory is employed to calculate the scattering parameters of the connection of the plasmonic waveguides. In this manner, the gating effects of the graphene waveguide on the input reflection and transmission of the junction are also investigated. For comparison, a full wave numerical simulator is employed. Keywords— Graphene, plasmonic; scattering parameters; terahertz; transmission line.
Additive twists of Fourier coefficients of modular forms

Abstract We study sums of the form ∑ n ⩽ N a ( n ) e 2 π i α n , where α is any real number and the a ( n ) are the Fourier coefficients of either a holomorphic cusp form, a Maass cusp form, or the symmetric-square lift of a holomorphic cusp form. We obtain bounds that are uniform in both α and the form itself. We also improve a bound on a sum of the form ∑ n ⩽ N a ( n ) e 2 π i ( α n + β n θ ) , where the a ( n ) are the Fourier coefficients of a holomorphic cusp form, α and β are any real numbers, and 0 ⩽ θ 1 . This last bound is uniform in α , but not with respect to the form.
Exact expressions for structure selection in cluster expansions

The cluster expansion has proven to be a valuable tool in materials science to predict properties of configurationally ordered and disordered structures but the generation of cluster expansions can be computationally expensive. In recent years there have been efforts to make the generation of cluster expansions more efficient by selecting training structures in a way that minimizes approximate expressions for the variance of the predicted property values. We demonstrate that in many cases, these approximations are not necessary and exact expressions for the variance of the predicted property values may be derived. To illustrate this result, we present examples based on common applications of the cluster expansion such as bulk binary alloys. In addition we extend these structure selection techniques to Bayesian cluster expansions. These results should enable researchers to better analyze the quality of existing training sets and to select training structures that yield cluster expansions with lower prediction error.
Nuclear data sheets for A = 230

Abstract Nuclear structure information for all nuclei with mass number A = 230 is evaluated. The results from various decay and reaction experiments are compared. Adopted data, levels, and spin and parity assignments are given.
P(RNCH2CH2)3N: An Efficient Promoter for the Nitroaldol (Henry) Reaction

The use of catalytic amounts of the proazaphosphatranes P(MeNCH2CH2)3N, P(i-PrNCH2CH2)3N and P(HNCH2CH2)(i-PrNCH2CH2)2N as nonionic bases in the reaction of nitroalkanes with carbonyl compounds is reported. The reaction proceeds at room temperature in the presence of 2.2 equiv of magnesium sulfate to produce the corresponding β-nitroalkanols in generally superior yields. Aldehydes react quantitatively in 5−60 min, whereas ketones require up to 3 h to react with nitromethane and up to 7 h for the reaction of ketones with higher nitroalkanes.
Exchange rate hysteresis? Large versus small policy misalignments

Abstract Using a monetary model in the spirit of Dornbusch (1976) and a sunk cost model of trade hysteresis we show that a sufficiently large policy misalignment can induce hysteresis in the trade balance and thereby alter the steady-state real exchange rate. Hence, exchange rate dynamics are path dependent. Since hysteresis in our model can entail industrial dislocation and the scrapping of sunk assets, we suggest that these factors constitute a welfare cost of large policy misalignments that have not been considered formally. Additionally, since the long-run exchange rate is path dependent, standard empirical tests of exchange rate models may involve a misspecification.
Loop groups, Kaluza-Klein reduction and M-theory

We show that the data of a principal G-bundle over a principal circle bundle is equivalent to that of a U(1) LG-bundle over the base of the circle bundle. We apply this to the Kaluza-Klein reduction of M-theory to IIA and show that certain generalized characteristic classes of the loop group bundle encode the Bianchi identities of the antisymmetric tensor fields of IIA supergravity. We further show that the low dimensional characteristic classes of the central extension of the loop group encode the Bianchi identities of massive IIA, thereby adding support to the conjectures of [1].
Total Synthesis of Swinholide A, Preswinholide A, and Hemiswinholide A

The total synthesis of synthesis of swinholide A (1) has been accomplished via key intermediate aldehyde 12 (Fig. 3), whose construction started from L-rhamnose (18), epoxide 21, and phenylsulfone orthoester 22, and proceeded through an Enders asymmetric alkylation (16 + 17 → 15), a Ghosez cyclization (21 + 22 → 20), and a Corey-Sharpless coupling reaction (13 + 14 → 12). Elaboration of compound 12 along slightly different pathways culminated in the synthesis of carboxylic acid 10 and hydroxy compound 11, whose union by an esterification reaction, followed by ring closure of the subsequently derived hydroxy acid under Yamaguchi conditions, led to swinholide A (1) upon deprotection. The chemistry developed also allowed the total synthesis of preswinholide A methyl ester (7), preswinholide A (8), and hemiswinholide A (78).
What drives merger waves

Abstract Aggregate merger waves could be due to market timing or to clustering of industry shocks for which mergers facilitate change to the new environment. This study finds that economic, regulatory and technological shocks drive industry merger waves. Whether the shock leads to a wave of mergers, however, depends on whether there is sufficient overall capital liquidity. This macro-level liquidity component causes industry merger waves to cluster in time even if industry shocks do not. Market-timing variables have little explanatory power relative to an economic model including this liquidity component. The contemporaneous peak in divisional acquisitions for cash also suggests an economic motivation for the merger activity.
Taxes and the Timing of Births

Because the tax savings of having a child are a realized only if the birth takes place before midnight, January 1, the incentives for the “marginal” birth are substantial. Using a sample of children from the National Longitudinal Survey of Youth, we find that the probability that a child is born in the last week of December, rather than the first week of January, is positively correlated with tax benefits. We estimate that increasing the tax benefit of having a child by $500 raises the probability of having the child in the last week of December by 26.9 percent.
Gamma-Ray Spectral Characteristics of Thermal and Non-Thermal Emission from Three Black Holes

Cygnus X-1 and the gamma-ray transients GRO J0422+32 and GRO J1719-24 displayed similar spectral properties when they underwent transitions between the high and low gamma-ray (30 keV to few MeV) intensity states. When these sources were in the high γ-ray intensity state (γ2, for Cygnus X-1), their spectra featured two components: a Comptonized shape below 200-300keV with a soft power-law tail (photon index >3) that extended to ~1MeV or beyond.When the sources were in the low-intensity state (γ0, for Cygnus X-1), the Comptonized spectral shape below 200 keV typically vanished and the entire spectrum from 30 keV to ~1MeV can be characterized by a single power law with a relatively harder photon index ~2–2.7. Consequently the high- and low-intensity gamma-ray spectra intersect, generally in the ~400 keV – ~1MeV range, in contrast to the spectral pivoting seen previously at lower (~10 keV) energies. The presence of the power-law component in both the high- and low-intensity gamma-ray spectra strongly suggests that the non-thermal process is likely to be at work in both the high and the low-intensity situations. We have suggested a possible scenario (Ling & Wheaton, 2003), by combining the ADAF model of Esin et al. (1998) with a separate jet region that produces the non-thermal gamma-ray emission, and which explains the state transitions. Such a scenario will be discussed in the context of the observational evidence, summarized above, from the database produced by EBOP, JPL's BATSE earth occultation analysis system.
Distributed Storage Allocations

We examine the problem of allocating a given total storage budget in a distributed storage system for maximum reliability. A source has a single data object that is to be coded and stored over a set of storage nodes; it is allowed to store any amount of coded data in each node, as long as the total amount of storage used does not exceed the given budget. A data collector subsequently attempts to recover the original data object by accessing only the data stored in a random subset of the nodes. By using an appropriate code, successful recovery can be achieved whenever the total amount of data accessed is at least the size of the original data object. The goal is to find an optimal storage allocation that maximizes the probability of successful recovery. This optimization problem is challenging in general because of its combinatorial nature, despite its simple formulation. We study several variations of the problem, assuming different allocation models and access models. The optimal allocation and the optimal symmetric allocation (in which all nonempty nodes store the same amount of data) are determined for a variety of cases. Our results indicate that the optimal allocations often have nonintuitive structure and are difficult to specify. We also show that depending on the circumstances, coding may or may not be beneficial for reliable storage.
Altered proteoglycan gene expression and the tumor stroma

Tumor stroma is a specialized form of tissue that is associated with epithelial neoplasms. Recent evidence indicates that significant changes in proteoglycan content occur in the tumor stroma and that these alterations could support tumor progression and invasion as well as tumor growth. Our main hypothesis is that the generation of tumor stroma is under direct control of the neoplastic cells and that, via a feedback loop, altered proteoglycan gene expression would influence the behavior of tumor cells. In this review, we will focus primarily on the work from our laboratory related to the altered expression of chondroitin sulfate proteoglycan and its role in tumor development and progression. The connective tissue stroma of human colon cancer is enriched in chondroitin sulfate and the stromal cell elements, primarily colon fibroblasts and smooth muscle cells, are responsible for this biosynthetic increase. These changes can be reproduced in vitro by using either tumor metabolites or co-cultures of human colon carcinoma cells and colon mesenchymal cells. The levels of decorin, a leucine-rich proteoglycan involved in the regulation of matrix assembly and cell proliferation, are markedly elevated in the stroma of colon carcinoma. These changes correlate with a marked increase in decorin mRNA levels and a concurrent hypomethylation of decorin gene, a DNA alteration associated with enhanced gene expression. Elucidation of decorin gene structure has revealed an unexpected degree of complexity in the 5′ untranslated region of the gene with two leader exons that are alternatively spliced to the second coding exon. Furthermore, a transforming growth factor beta (TGF-β)-negative element is present in the promoter region of decorin gene. This regulatory domain is likely to be implicated in the silencing of decorin gene by TGF-β and may contribute to the regulation of this matrix gene in the tumor stroma.
An ecological valence theory of human color preferences

Color preference is an important aspect of visual experience, butlittle is known about why people in general like some colors morethan others. Previous research suggested explanations based onbiologicaladaptations[HurlbertAC,LingYL(2007)CurrBiol17:623–625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A(2004) Color Res Appl 29:381–389]. In this article we articulate anecological valence theory in which color preferences arise frompeople’s average affective responses to color-associated objects.An empirical test provides strong support for this theory: Peoplelike colors strongly associated with objects they like (e.g., blueswith clear skies and clean water) and dislike colors strongly associ-ated with objects they dislike (e.g., browns with feces and rottenfood).Relativetoalternativetheories,theecologicalvalencetheoryboth ﬁts the data better (even with fewer free parameters) andprovides a more plausible, comprehensive causal explanation ofcolor preferences.
Clar Polynomials of Large Benzenoid Systems

We discuss the constructions of Clar-like valence structures and the associated Clar polynomials for large benzenoids. We have shown that Clar polynomial satisfy a theorem analogous to the Clarke's theorem for the characteristic polynomial of graphs, which allows one to reconstruct the polynomial of a system from the polynomials associated with qualified substructures. In the case of Clar's polynomial the substructures are obtained by deleting individual benzene rings from the considered benzenoid, one at a time. This property of Clar polynomial allows one to construct the polynomial of larger systems from known Clar's polynomials of smaller benzenoids.
Conflict between anthropic reasoning and observation

Anthropic reasoning often begins with the premise that we should expect to find ourselves typical among all intelligent observers. However, in the infinite universe predicted by inflation, there are some civilizations which have spread across their galaxies and contain huge numbers of individuals. Unless the proportion of such large civilizations is unreasonably tiny, most observers belong to them. Thus anthropic reasoning predicts that we should find ourselves in such a large civilization, while in fact we do not. There must be an important flaw in our understanding of the structure of the universe and the range of development of civilizations, or in the process of anthropic reasoning.
Non-BPS D-branes and enhanced symmetry in an asymmetric orbifold

In this paper properties of D-branes in a nine dimensional asymmetric orbifold are discussed, using a (−1)FLσ1/2 projection, where FL is the leftmoving space-time fermion number and σ1/2 is a freely acting shift of order two. There are two types of non BPS D branes, which are stable at R > 2 and R < 2 respectively. At R = 2 there is a perturbative enhancement of gauge symmetry and the two types of branes are related by a global bulk symmetry transformation. At this point in the moduli space the associated boundary states are constructed using a free fermion representation of the theory. Some aspects of the enhancement of gauge symmetry in the S-dual type- theory are discussed.
Bond Forming Reactions Involving C1 Moieties: Late Versus Early Transition Metal Surfaces

A brief survey is provided on the contrast in the surface chemistry of C1 adsorbed species on vanadium versus nickel and platinum single crystals. Mechanistic insights from modern surface-studies under ultrahigh vacuum are offered to explain reaction selectivities in terms of relative rates for different types of surface elementary steps, namely, hydrogenation, dehydrogenation, coupling, and methylene and oxygen insertions. It is clear from the surface chemistry reviewed here that early transition metals such as vanadium are quite reactive, but also that they are still able to promote interesting bond-forming reactions, and could possibly be used to prepare novel catalysis.
Cardiac dynamic analysis using hierarchical shape models and Gaussian curvature recovery: an integrated approach

We present in this paper a scheme to analyze the left ventricle motion over a cardiac cycle through the integration of the hierarchical surface fitting and the point correspondence estimation. The hierarchical surface fitting is a coarse-to-fine analysis scheme and has been successfully applied to cine-angiographic cardiac images. In this study, the hierarchical surface fitting and motion analysis is applied to a set of CT images with real volumetric nature. We also incorporate an additional global deformation, long axis bending, into the shape model to reflect the curved nature of the left ventricle long axis. With the dense volumetric data, we are able to implement higher order spherical harmonics in the analysis of the local deformations. The fitted surface allows us a complete recovery of the Gaussian curvature of the shape. The estimation of the point correspondence is accomplished through the analysis of the first fundamental form and the Gaussian curvature computed from the fitted shape assuming conformal motion. The overall coarse-to-fine hierarchical analysis and the parametric nature of the fitted surface enable us to compute the Gaussian curvature analytically and gain a clear and complete description of the left ventricle dynamics based on the shape evolution over the cardiac cycle. Results based on a set of CT data of 16 volumes show that this hierarchical surface fitting and motion analysis scheme is promising for cardiac analysis.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
SYNTHESIS OF THE VANCOMYCIN CD AND DE RING SYSTEMS

Full details of the synthesis of the fully substituted vancomycin CD and DE ring systems are described and a potential solution to the control of the atropisomer stereochemistry is defined.
Optical MEMS: boom, bust and beyond

Optical telecommunications bandwidth, spurred by the growth of the Internet, experienced unprecedented growth in the late 1990's. The creation of new enterprises was vast and the expansion of established component, system and services companies was also breathtaking. This period of speculative growth was followed in 2001-2004 by one of the most significant market crashes in history. While $20B of venture capital was invested in optical telecom in the last 10 years, the vast majority of that was lost in recent years. With this, many start-up company who experienced unprecedented growth inaugurated with great fanfare at the end of the 20/sup th/ century were unceremoniously shut down at the start of the 21st. As in all speculative bubbles, innovative technologies were born and buried. Nonetheless, new capabilities emerge from the chaos and disruption; one such example is the advent of optical MEMS (MOEMS). Its development was vigorously pursued in both academic and corporate laboratories during the boom and, in the author's view; MOEMS constitutes a powerful and versatile tool set that is an invaluable residual of the last few years. In telecommunications, MOEMS has proven to be the technology of choice for many optical switching and wavelength management applications. Variable optical attenuators (VOA), wavelength blockers (WB), dynamic gain equalizers (DGE), and most recently wavelength selective switches (WSS) are being used in the numerous recent network deployments. Moreover, agile networks of the future will have MOEMS at every node. This presentation will provide an overview of the history of MOEMS in Telecommunications, discuss its byproducts and project the future of the technology.
The Effect of Probabilistic Selling on the Optimal Product Mix

Determination of the merchandize assortment is an important decision for retailers since the composition and depth of the product mix greatly impact both unit sales and costs. This paper considers how Probabilistic Selling (PS), an emerging marketing strategy, impacts the type and number of products a retailer should carry. We find that adopting PS can alter the optimal number of products (i.e., encourage the retailer to offer more or fewer products), depending on demand- and supply-side factors. Furthermore, introducing probabilistic goods sometimes increases the optimal degree of product differentiation and sometimes reduces it. Specifically, less differentiated products are warranted if there are either few or many consumers with extreme tastes, but more differentiation is needed otherwise. Our analysis reveals that PS can serve either as a substitute to new product introduction (because it enables a retailer to serve a diverse market at a lower cost) or as a complement to new product introduction (since, under PS, a new product enables a retailer to offer additional probabilistic goods that utilize this new product as one of its components). In sum, our results indicate that a retailer must adjust its merchandize assortment appropriately in order to fully benefit from probabilistic selling.
Crystal chemistry of thorium nitrates and chromates

Abstract The structures and infrared spectra of six novel thorium compounds are reported. Th(NO3)2(OH)2(H2O)2 (1) crystallizes in space group C2/c, a=14.050(1), b=8.992(7), c=5.954(5) A, β=101.014(2)°. K2Th(NO3)6 (2), P-3, a=13.606(1), c=6.641(6) A. (C12H28N)2Th(NO3)6 (3), P21/c, a=14.643(4), b=15.772(5), c=22.316(5) A, β=131.01(1)°. KTh(NO3)5(H2O)2 (4), P21/c, a=10.070(8), b=12.731(9), c=13.231(8) A, β=128.647(4)°. Th(CrO4)2(H2O)2 (5), P21/n, a=12.731(1), b=9.469(8), c=12.972(1) A, β=91.793(2)°. K2Th3(CrO4)7(H2O)10 (6), Ama2, a=19.302(8), b=15.580(6), c=11.318(6) A. The coordination polyhedra about Th in these structures are diverse. Th is coordinated by 9 O atoms in 5 and 6, seven of which are from monodentate (CrO4) tetrahedra and two are (H2O). The Th in compound 1 is coordinated by ten O atoms, four of which are O atoms of two bidentate (NO3) triangles and six of which are (OH) and (H2O). In compounds 2, 3 and 4 the Th is coordinate by 12 O atoms. In 2 and 3 there are six bidentate (NO3) triangles, and in 4 ten of the O atoms are part of five bidentate (NO3) triangles and the others are (H2O) groups. The structural units of these compounds consist of a chain of thorium and nitrate polyhedra (1), isolated thorium hexanitrate clusters (2, 3), an isolated thorium pentanitrate dihydrate cluster (4), and a sheet (6) and framework (5) of thorium and chromate polyhedra. These structures illustrate the complexity inherent in the crystal chemistry of Th.
Peer influences on adolescent alcohol consumption: evidence using an instrumental variables/fixed effect approach

In order to address empirical difficulties in research examining peer effects in alcohol consumption, I use instrumental variables/fixed effects methodology that compares students in different grades within the same school who face a different set of classmate decisions. Within this context, I suggest that alcohol availability in classmates’ homes and classmates’ parents’ alcohol abuse can be used as instruments. Results indicate that a 10% increase in the proportion of classmates who drink increases the likelihood an individual drinks by five percentage points. This paper also provides evidence of peer effects in problem drinking, such as binge drinking and drunkenness.
Design, synthesis, and antiviral evaluation of 2-substituted 4,5-dichloro- and 4,6-dichloro-1-β-D-ribofuranosylbenzimidazoles as potential agents for human cytomegalovirus infections

The syntheses of 2,4,6-trichlorobenzimidazole (4a) and 2-bromo-4,6-dichlorobenzimidazole (4b) were accomplished via the 2-amino intermediate (3) using a mild diazotization procedure. Ribosylation of 4a and 4b and subsequent deprotection afforded the corresponding 2,4,6-trichloro-1-beta-D-ribofuranosylbenzimidazole (7a) and 2-bromo-4,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (7b). The 2-azido (10), 2-amino (11), 2-thione (13), 2-methylthio (14a), and 2-benzylthio (14b) derivatives were prepared via displacement reactions at the 2-position of the 2,3,5-tri-O-acetyl derivative of 7a. 2,4,5-Trichlorobenzimidazole (17a) and 2-bromo-4,5-dichlorobenzimidazole (17b) were synthesized from the corresponding 1,2-phenylenediamines via successive cyclization with cyanogen bromide and diazotization in the presence of an appropriate cupric halide. Ribosylation of compounds 17a and 17b was followed by deprotection to afford 2,4,5-trichloro-1-beta-D-ribofuranosylbenzimidazole (20a), and 2-bromo-4,5-dichloro-1-beta-D-ribofuranosylbenzimidazole (20b). Heterocycles (3, 4a, 17a) and nucleosides (7a, b, 8, 10, 11, 13, 14a,b, 20a,b) were evaluated for activity against human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) and for cytotoxicity. The 2-chloro but not the 2-amino heterocycles were active against HCMV (IC50's = 5-8 microM) but not HSV-1; both also were somewhat cytotoxic to uninfected cells (IC50's = 32-100 microM). Among the nucleosides, the 2-chloro and 2-bromo analogs in both the 4,5- and 4,6-dichloro series (20a,b, 7a,b, respectively) were active against HCMV (IC50's = 1-10 microM) and noncytotoxic in their antiviral dose ranges. The 2-bromo compounds were more active than the 2-chloro analogs; the 2-azido and 2-thiobenzyl analogs (10, 14b) were weakly active against HCMV, but this activity was not well separated from cytotoxicity. None of the nucleosides were active against HSV-1. This pattern of activity and cytotoxicity is similar to that of the 2-chloro- and 2-bromo-5,6-dichloro analogs (TCRB, BDCRB) which we reported previously. Although these new 4,5- and 4,6-dichloro analogs are potent and selective inhibitors of HCMV, they are not as potent at TCRB and BDCRB.
Mechanism design for data science

The promise of data science is that if data from a system can be recorded and understood then this understanding can potentially be utilized to improve the system. Behavioral and economic data, however, is different from scientific data in that it is subjective to the system. Behavior changes when the system changes, and to predict behavior for any given system change or to optimize over system changes, the behavioral model that generates the data must be inferred from the data. The ease with which this inference can be performed generally also depends on the system. Trivially, a system that ignores behavior does not admit any inference of a behavior generating model that can be used to predict behavior in a system that is responsive to behavior. To realize the promise of data science in economic systems, a theory for the design of such systems must also incorporate the desired inference properties. Consider as an example the revenue-maximizing auctioneer. If the auctioneer has knowledge of the distribution of bidder values then she can run the first-price auction with a reserve price that is tuned to the distribution. Under some mild distributional assumptions, with the appropriate reserve price the first-price auction is revenue optimal [Myerson 1981]. Notice that the historical bid data for the first-price auction with a reserve price will in most cases not have bids for bidders whose values are below the reserve. Therefore, there is no data analysis that the auctioneer can perform that will enable properties of the distribution of bidder values below the reserve price to be inferred. It could be, nonetheless, that over time the population of potential bidders evolves and the optimal reserve price lowers. This change could go completely unnoticed in the auctioneer's data. The two main tools for optimizing revenue in an auction are reserve prices (as above) and ironing. Both of these tools cause pooling behavior (i.e., bidders with distinct values take the same action) and economic inference cannot thereafter differentiate these pooled bidders. In order to maintain the distributional knowledge necessary to be able to run a good auction in the long term, the auctioneer must sacrifice the short-term revenue by running a non-revenue-optimal auction.
Still Looking for Audience Costs

Eighteen years after publication of James Fearon's article stressing the importance of domestic audience costs in international crisis bargaining, we continue to look for clear evidence to support ...
Silyl trifluoromethanesulfonate-activated para-methoxybenzyl methyl ether as an alkylating agent for thiols and aryl ketones

Abstract para-Methoxybenzyl methyl ether acts as an alkylating agent for thiols in the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base in good yields (58–96%). Aryl ketones are alkylated under similar conditions, probably through an enol silane intermediate, also in high yields (67–95%). The active alkylating species is likely a p-methoxybenzyl cation.
Pd(II)-Catalyzed Hydroxylation of Arenes with 1 atm of O2 or Air

Pd(II)-catalyzed ortho-hydroxylation of variously substituted benzoic acids under 1 atm of O2 or air is achieved under nonacidic conditions. Extensive labeling studies support a direct oxygenation of aryl C−H bonds with molecular oxygen.
EXTENDING MIRROR CONJECTURE TO CALABI–YAU WITH BUNDLES

We define the notion of mirror of a Calabi–Yau manifold with a stable bundle in the context of type II strings in terms of supersymmetric cycles on the mirror. This allows us to relate the variation of Hodge structure for cohomologies arising from the bundle to the counting of holomorphic maps of Riemann surfaces with boundary on the mirror side. Moreover it opens up the possibility of studying bundles on Calabi–Yau manifolds in terms of supersymmetric cycles on the mirror.
Axial instability of rotating relativistic stars

Perturbations of rotating relativistic stars can be classified by their behavior under parity. For axial perturbations (r-modes), initial data with negative canonical energy is found with angular dependence eim for all values of m ≥ 2 and for arbitrarily slow rotation. This implies instability (or marginal stability) of such perturbations for rotating perfect fluids. This low m-instability is strikingly different from the instability to polar perturbations, which sets in first for large values of m. The timescale for the axial instability appears, for small angular velocity Ω, to be proportional to a high power of Ω. As in the case of polar modes, viscosity will again presumably enforce stability except for hot, rapidly rotating neutron stars. This work complements Andersson's numerical investigation of axial modes in slowly rotating stars.
Elasticity Approach for Delamination Buckling of Composite Beam Plates

An elasticity-theory-based approach is developed for delamination buckling of simply supported composite laminates whose behavior is referred to as cylindrical bending. The approach ensures an accurate description of the transverse shear and the transverse normal effects in delamination buckling of composite plates. The uniform prebuckling stress assumption, which is comparable to the membrane assumption used in plate theories, is made for deriving the elasticity-theory-based buckling equations. The dosed-form expressions for the displacements and stresses are derived, and the nonlinear eigenvalue equations that are used to solve for critical loads are presented. The results obtained from the elasticity solution are compared with the critical loads furnished by the existing classical laminate theory and a previously developed higher-order shear deformation theory. The solution provides a means of accurate assessment of existing plate theories used in delamination buckling problems.
Design of an epidemiologic study of drinking water arsenic exposure and skin and bladder cancer risk in a U.S. population.

Ingestion of arsenic-contaminated drinking water is associated with an increased risk of several cancers, including skin and bladder malignancies; but it is not yet clear whether such adverse effects are present at levels to which the U.S. population is exposed. In New Hampshire, detectable levels of arsenic have been reported in drinking water supplies throughout the state. Therefore, we have begun a population-based epidemiologic case-control study in which residents of New Hampshire diagnosed with primary squamous cell (n = 900) and basal cell (n = 1200) skin cancers are being selected from a special statewide skin cancer incidence survey; patients diagnosed with primary bladder cancers (n = 450) are being identified through the New Hampshire State Cancer Registry. Exposure histories of these patients will be compared to a control group of individuals randomly selected from population lists (n = 1200). Along with a detailed personal interview, arsenic and other trace elements are being measured in toenail clipping samples using instrumental neutron activation analysis. Household water samples are being tested on selected participants using a hydride generation technique with high-resolution inductively coupled plasma mass spectrometry. In the first 793 households tested arsenic concentrations ranged from undetectable (0.01 microgram/l) to 180 microgram/l. Over 10% of the private wells contained levels above 10 microgram/l and 2.5% were above 50 microgram/l. Based on our projected sample size, we expect at least 80% power to detect a 2-fold risk of basal cell or squamous cell skin cancer or bladder cancer among individuals with the highest 5% toenail concentrations of arsenic.
Spontaneous generation of density perturbations in the early Universe

A long-standing problem in cosmology has been to understand the origins of density inhomogeneities in the Universe. Calculations involving inhomogeneities have for the most part required the assumption of some initial spectrum of perturbations, which is inserted ‘by hand’. We present here a mechanism for the spontaneous creation of density perturbations during the transition in the early Universe from unconfined quark matter to hadronic matter. The subsequent evolution of these perturbations remains a problem for further study.
A Solar-Wind Model Including Proton Thermal Anisotropy

A relatively simple model is proposed to study the magnetohydrodynamic expansion of the solar wind. The interplanetary space is divided into an 'inner region' and an 'outer region.' In the inner region the solar wind is one-fluid and thermally isotropic. The solar-wind protons are assumed to be completely collisionless in the outer region. Thus the solar wind is two-fluid in nature, and the protons are thermally anisotropic in the outer region. It is assumed that throughout the interplanetary space electrons are thermally isotropic due to collisions or other processes. The electron heat flux is supposed to obey the well-known relationships that the flux is parallel to the magnetic-field vector and is directly proportional to the spatial derivative of the electron temperature.
Free Energies of Dilute Bose Gases: Upper Bound

We derive an upper bound on the free energy of a Bose gas at density ϱ and temperature T. In combination with the lower bound derived previously by Seiringer (Commun. Math. Phys. 279(3): 595–636, 2008), our result proves that in the low density limit, i.e., when a3ϱ≪1, where a denotes the scattering length of the pair-interaction potential, the leading term of Δf, the free energy difference per volume between interacting and ideal Bose gases, is equal to \(4\pi a(2\varrho^{2}-[\varrho-\varrho_{c}]^{2}_{+})\). Here, ϱc(T) denotes the critical density for Bose–Einstein condensation (for the ideal Bose gas), and [⋅]+=max {⋅,0} denotes the positive part.
M31 GLOBULAR CLUSTER ABUNDANCES FROM HIGH-RESOLUTION, INTEGRATED-LIGHT SPECTROSCOPY*

We report the first detailed chemical abundances for five globular clusters (GCs) in M31 from high-resolution (R ~ 25,000) spectroscopy of their integrated light (IL). These GCs are the first in a larger set of clusters observed as part of an ongoing project to study the formation history of M31 and its GC population. The data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope and are analyzed using a new IL spectra analysis method that we have developed. In these clusters, we measure abundances for Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba, ages ≥10 Gyr, and a range in [Fe/H] of –0.9 to –2.2. As is typical of Milky Way GCs, we find these M31 GCs to be enhanced in the α-elements Ca, Si, and Ti relative to Fe. We also find [Mg/Fe] to be low relative to other [α/Fe], and [Al/Fe] to be enhanced in the IL abundances. These results imply that abundances of Mg, Al (and likely O, Na) recovered from IL do display the inter- and intra-cluster abundance variations seen in individual Milky Way GC stars, and that special care should be taken in the future in interpreting low- or high-resolution IL abundances of GCs that are based on Mg-dominated absorption features. Fe-peak and the neutron-capture elements Ba and Y also follow Milky Way abundance trends. We also present high-precision velocity dispersion measurements for all five M31 GCs, as well as independent constraints on the reddening toward the clusters from our analysis.