cssi/SciSciGPT-SciSciNet huggingface dataset:
Intramolecular anodic olefin coupling reactions: Initial studies concerning the use of electron-rich aryl rings

Abstract Intramolecular anodic olefin coupling reactions involving electron-rich aryl rings were examined and shown to afford fused bicyclic products. When alkoxysubstituted phenyl rings were used, the reactions benefited from the use of either controlled potential electrolysis conditions or a vinyl sulfide initiating group. Coupling reactions involving heteroatomic aryl rings also led to good yields of cyclized product.
A catalytic homo-Nazarov cyclization protocol for the synthesis of heteroaromatic ring-fused cyclohexanones.

A general protocol for the catalytic homo-Nazarov cyclization of cyclopropyl heteroaryl ketones has been developed, which employs indium triflate as the promoter. A range of heteroaromatic ring-fused cyclohexanones was synthesized in 56−91% yield using this protocol. An example of a tandem cyclopropanation/homo-Nazarov cyclization is also reported in which the one-pot yield is greater than the overall yield of the two individual steps.
Energy-Optimal Scheduling with Dynamic Channel Acquisition in Wireless Downlinks

We consider a wireless base station serving L users through L time-varying channels. It is well known that opportunistic scheduling algorithms with full channel state information (CSI) can stabilize the system with any data rates within the capacity region. However, such opportunistic scheduling algorithms may not be energy efficient when the cost of channel acquisition is high and traffic rates are low. In particular, under the low traffic rate regime, it may be sufficient and more energy efficient to transmit data with no CSI, i.e., to transmit data blindly, since no power for channel acquisition is consumed. In general, we show strategies that probe channels in every slot or never probe channels in any slot are not necessarily optimal, and we must consider mixed strategies. We derive a unified scheduling algorithm that dynamically chooses to transmit data with full or no CSI based on queue backlog and channel statistics. Our methodology is general and can be naturally extended to include timing overhead due to channel acquisition, and to treat systems that allow any subset of channels to be measured. Through Lyapunov analysis, we show that the unified algorithm is throughput-optimal and stabilizes the downlink with optimal power consumption, balancing well between channel-aware and channel-blind transmission modes.
Progress in Photonic Crystal Vertical Cavity Lasers

Recent progress and achievements in creating single fundamental mode vertical cavity lasers with the technique of etching a 2-dimensional pattern of photonic crystal holes into the top distributed Bragg reflector are described. A simulation method for the design of single mode lasers is described, along with accuracy and limitations in predicting modal properties in these devices. Progress in improving output power, methods of lowering threshold currents, and small signal modulation of single mode lasers are discussed.
Probing selective oxidation catalysis under reaction conditions by atomic scale environmental high resolution electron microscopy

Major striking advances in the field of environmental high resolution electron microscopy have been achieved for probing selective oxidation catalysis directly on the atomic scale. Outstanding contributions are resulting from the ability to observe in real-time live gas molecule—catalyst surface interactions close to their natural reaction state and the unraveling of atomic-level insights into active sites and structure-activity relationships in vital chemical and technological processes. Recent examples in this burgeoning field include discoveries of novel reaction processes for the release of structural oxygen in alkane catalysis, finely dispersed nanophase metal catalysts that can be used in the hydrodechlorination of 1, 1 -dichlorotetrafluroethanes, interactions in catalytic reforming of methane and emission control catalysis, special classes of solid acid catalysts, and carbon nanotubes and fullerenes.
The Maslov Gerbe

Let Lag(E) be the Grassmannian of Lagrangian subspaces of a complex symplectic vector space E. We construct a Maslov class which generates the second integral cohomology of Lag(E), and we show that its mod 2 reduction is the characteristic class of a flat gerbe with structure group Z2. We explain the relation of this gerbe to the well-known flat Maslov line bundle with structure group Z4 over the real Lagrangian Grassmannian, whose characteristic class is the mod 4 reduction of the real Maslov class.
Does Globalization Affect Regional Growth? Evidence for Nuts-2 Regions in EU-27

We analyze the inuence of newly constructed globalization measures on regional growth for the EU-27 countries between 2001 and 2006. The spatial Chow-Lin procedure, a method constructed by the authors, was used to construct on a NUTS-2 level a complete regional data for exports, imports and FDI inward stocks, which serve as indicators for the inuence of globalization, integration and technology transfers on European regions. The results suggest that most regions have signicantly beneted from globalization measured by increasing trade openness and FDI. In a non-linear growth convergence model the growth elasticities for globalization and technology transfers decrease with increasing GDP per capita. Furthermore, the estimated elasticity for FDI decreases when the model includes a higher human capital premium for CEE countries and a small signicant growth enhancing eect accrues from the structural funds expenditures in the EU.
A new synthetic route to functionally substituted (η5-cyclopentadienyl) dicarbonyliridium compounds

Abstract A series of functionally substituted ( η 5 -cyclopentadienyl) dicarbonyliridium compounds have been prepared from reactions of the corresponding substituted cyclopentadienyl-sodium, -lithium, or -thallium reagents with chlorodicarbonyl(pyridine)iridium. Ring-substituted compounds synthesized by this route include chloro, benzyl, pentabenzyl, acetyl, carbomethoxy, methyl, benzoyl, trimethylsilyl, cyano, dimethylamino, tetraphenyl, dimethylaminoethyl, (tetramethyl)dimethylaminoethyl, methoxyethyl and pentamethyl. The symmetric and asymmetric carbonyl stretching frequencies as well as the 13 C NMR chemical shifts of the carbonyl substituents have been correlated with various Hammett substituent parameters.
New examples of $p$-adically rigid automorphic forms

In this paper, we prove two $p$-adic rigidity results for automorphic forms for the quasi-split unitary group in three variables $\U(2,1)$ attached to a quadratic imaginary field. We show first that the discrete automorphic forms for this group that are cohomological in degree $1$ (and refined, with a non semi-ordinary refinement) are rigid, in the sense that they can not be interpolated in a positive dimensional $p$-adic family, even though the set of Hodge-Tate weights of all such forms is not $p$-adically discrete. This results implies that the eigenvariety of $\U(2,1)$ in cohomological degree $1$, if it exists in the sense of \cite{E} (or \cite{BCbook}), is not equi-dimensional. Hence the situation for the quasi-split unitary group is in striking contrast with the one for its definite inner form $\U(3)$ and more generally any definite reductive group. We then show that some of the automorphic forms considered above, namely the ones that are minimally ramified in their $A$-packet and attached to an Hecke character whose $L$-function does not vanish at the center of its functional equation, are even rigid in the stronger sense that they can not be put in a non trivial family interpolating cohomological automorphic forms {\it in any degree}.
Strategies for the Synthesis of C-disaccharides containing D and L sugars

Abstract The osmylation of C-1 homologated diene ester monosaccharides readily affords C-disaccharides of diverse but predictable stereochemistry. As an example, D-glu-α(1,6)-D-gal ( 3 ), D-glu-α(1,6)-L-gal ( 4 ), D-glu-α(1,6)-D-ido ( 10 ), and ( 10 ), and D-glu-α(1,6)-L-ido ( 11 ) were synthesized from a single precursor.
Silver (fluorosulfonyl)difluoroacetate - A new route to fluorosulfonyl esters

Abstract New fluorinated esters of the type FSO 2 CF 2 C(O)OR and (FSO 2 CF 2 C(O)O) 2 R′, (R = CH 3 , CH 3 CH 2 CH 2 , (CH 3 ) 3 Si, BrCH 2 CH 2 , CH 3 CH 2 OC(O)CH 2 , CH 2 = CHCH 2 ; R′ = CH 2 , CH 2 CH 2 , have been prepared and characterized via the reaction of silver difluoro(fluorosulfony)acetate with alkylbromides, alkyliodides, and trimethylsilyl iodide. All new compounds have been characterized by their respective IR/MS/NMR spectra.
Strongly non-embeddable metric spaces

Abstract Enflo (1969) [4] constructed a countable metric space that may not be uniformly embedded into any metric space of positive generalized roundness. Dranishnikov, Gong, Lafforgue and Yu (2002) [3] modified Enfloʼs example to construct a locally finite metric space that may not be coarsely embedded into any Hilbert space. In this paper we meld these two examples into one simpler construction. The outcome is a locally finite metric space ( Z , ζ ) which is strongly non-embeddable in the sense that it may not be embedded uniformly or coarsely into any metric space of non-zero generalized roundness. Moreover, we show that both types of embedding may be obstructed by a common recursive principle. It follows from our construction that any metric space which is Lipschitz universal for all locally finite metric spaces may not be embedded uniformly or coarsely into any metric space of non-zero generalized roundness. Our construction is then adapted to show that the group Z ω = ⊕ ℵ 0 Z admits a Cayley graph which may not be coarsely embedded into any metric space of non-zero generalized roundness. Finally, for each p ⩾ 0 and each locally finite metric space ( Z , d ) , we prove the existence of a Lipschitz injection f : Z → l p .
A W-band stacked FET power amplifier with 17 dBm P sat in 45-nm SOI CMOS

A 90GHz power amplifier implemented with three series-connected (stacked) FETs in 45-nm SOI CMOS is reported. Stacking FETs allows increasing voltage handling capability of circuits with highly scaled CMOS transistors. This work shows for the first time that the stacking strategy is effective up to W band. The amplifier achieves power gain of 8 dB at 91 GHz with 3 dB bandwidth of 18 GHz using a supply voltage of 4.2 V. It delivers saturated output power of 17.3 dBm in 88-90 GHz range with peak PAE of 9 %. The PA chip occupies 0.256 mm2 including the pads. This chip demonstrates the highest output power from a CMOS PA in this frequency regime.
Accelerated Imaginary‐time Evolution Methods for the Computation of Solitary Waves

Two accelerated imaginary-time evolution methods are proposed for the computation of solitary waves in arbitrary spatial dimensions. For the first method (with traditional power normalization), the convergence conditions as well as conditions for optimal accelerations are derived. In addition, it is shown that for nodeless solitary waves, this method converges if and only if the solitary wave is linearly stable. The second method is similar to the first method except that it uses a novel amplitude normalization. The performance of these methods is illustrated on various examples. It is found that while the first method is competitive with the Petviashvili method, the second method delivers much better performance than the first method and the Petviashvili method.
Restrictive Physiology is Associated With Poor Outcomes in Children With Hypertrophic Cardiomyopathy

Pediatric patients with hypertrophic cardiomyopathy (HCM) and restrictive physiology (RP) with poor outcomes have been identified, but data on their course are limited. Our goal was to delineate the clinical features and course of children with HCM and RP. An institutional review of 119 patients identified between 1985 and 2010 with the diagnosis of HCM was performed. The diagnosis of RP was based on >1 echocardiogram along with at least one of the following: left atrial enlargement without evidence of left ventricle dilation, E/E′ ratio ≥ 10, and E/A ratio ≥ 3. Outcomes analysis was performed using Cox or Poisson regression when appropriate. RP was present in 50 (42%) patients. In patients without RP, 10-year freedom-from-death or aborted sudden cardiac death (aSCD), and death or heart transplant (HT), were 93.6 and 98.5%, respectively. In patients with RP, 10-year freedom-from-death or aSCD, and death or HT, were 59.0 and 71.2%, respectively. RP conferred a 3.5-fold increase in incidence rate of hospitalization (P = 0.01), a 3.8-fold increase in hazard of death or aSCD (P = 0.02), and a 5.7-fold increase in hazard of death or HT (P = 0.04). Assessment for RP is of paramount importance in children with HCM because those without RP have a good prognosis, and those with RP account for the majority of poor outcomes.
A practical enantioselective total synthesis of the bengamides B, E, and Z.

A practical total synthesis of Bengamides B, E, and Z from a common polyol intermediate is described. Consecutive aldol condensations afford a protected polyol thioester side chain suitable for coupling to the Bengamides. A novel chiral phase transfer catalyzed enantioselective alkylation affords the more highly functionalized amino caprolactams required for Bengamides B and Z. Use of the 2-naphthylmethyl ether protecting group, compatible with the boron Lewis acids required for enantioselective aldol condensation, allows direct access to Bengamide B.
Structured Matrix Completion with Applications to Genomic Data Integration

ABSTRACTMatrix completion has attracted significant recent attention in many fields including statistics, applied mathematics, and electrical engineering. Current literature on matrix completion focuses primarily on independent sampling models under which the individual observed entries are sampled independently. Motivated by applications in genomic data integration, we propose a new framework of structured matrix completion (SMC) to treat structured missingness by design. Specifically, our proposed method aims at efficient matrix recovery when a subset of the rows and columns of an approximately low-rank matrix are observed. We provide theoretical justification for the proposed SMC method and derive lower bound for the estimation errors, which together establish the optimal rate of recovery over certain classes of approximately low-rank matrices. Simulation studies show that the method performs well in finite sample under a variety of configurations. The method is applied to integrate several ovarian can...
Office Worker Response to an Automated Venetian Blind and Electric Lighting System: A Pilot Study

Abstract A prototype integrated, dynamic building envelope and lighting system designed to optimize daylight admission and solar heat gain rejection on a real-time basis in a commercial office building is evaluated. Office worker response to the system and occupant-based modifications to the control system are investigated to determine if the design and operation of the prototype system can be improved. Key findings from the study are: (1) the prototype integrated envelope and lighting system is ready for field testing, (2) most office workers (N= 14) were satisfied with the system, and (3) there were few complaints. Additional studies are needed to explain how illuminance distribution, lighting quality, and room design can affect workplane illuminance preferences.
Total Synthesis of Apoptolidin: Part 1. Retrosynthetic Analysis and Construction of Building Blocks

No less than 30 stereogenic elements, a highly unsaturated 20-membered macrocyclic system, four carbohydrate units, and unique biological activity, make the natural occurring apoptolidin (1) a challenging synthetic target. The retrosynthetic analysis revealed five key building blocks-three for the construction of the macrolide ring B and two prospective pendant saccharide units-which were synthesized in a highly convergent manner and then connected. Apoptolidin's rather labile nature proved particularly challenging in the final deprotection, purification, and characterization procedures.
Multiple Scattering in Clumpy Media. II. Galactic Environments

We present and discuss the results of new multiple-scattering radiative transfer calculations for three representative types of galactic environments, filled with either homogeneous or two-phase clumpy dust distributions. Extinction and scattering properties for two types of interstellar dust, similar to those found in the average diffuse medium of the Milky Way (MW) and the Bar of the Small Magellanic Cloud (SMC), are considered. The wavelength coverage extends from 1000 to 30000 A, with particular emphasis on the rest-frame UV. This makes these models especially applicable to starburst galaxies and Lyman-break galaxy samples. The examination of the models concentrates on the study of UV/visual/near-IR reddening effects, the wavelength dependence of attenuation, and on the changes that arise from the transition from homogeneous to clumpy dust distributions in different star/dust geometries. Embedded dust, especially when clumpy, leads to saturation at fairly low reddening values with correspondingly gray attenuation functions. This makes the assessment of the attenuation of the far-UV flux from starburst galaxies difficult, if only UV/visual/near-IR data are available. Existing data for UV-selected starburst galaxies indicate a range of UV attenuation factors of 0-150. Our models reproduce the "Calzetti Attenuation Law," provided one adopts SMC-type dust and a clumpy shell-type dust distribution surrounding the starbursts. The average far-UV attenuation factor for the Calzetti sample is found to be 7.4. The only relatively reliable measure for the UV attenuation factor for single galaxies was found in the ratio of the integrated far-IR flux to the far-UV flux, measured near 1600 A, requiring the measurement of the entire spectral energy distribution of galaxies.
Functionalization of 1-methyl-1H-imidazole-5- carboxylic acid at the C-2 position: efficient syntheses of 2-substituted t-butyl 1-methyl-1H-imidazole-5- carboxylates †

In the course of developing biomimetic models of the heme a 3 /Cu b site of cytochrome c oxidase, 1 we have established a straightforward method for attaching structurally diverse imidazole-based pickets on the porphyrin template via an amide link. 1a‐c Our experience indicates that subtle structural variations in the substitution pattern of such imidazoles usually have profound effects on chemical and electrocatalytic properties of the resulting compounds. Therefore, we set forth to develop efficient methods that would allow us to obtain a variety of 2-substituted 1-methyl-1H-imidazole-5-carboxylic acids. Herein, we report a convenient synthesis of various 2substituted t-butyl 1-methyl-1H-imidazole-5-carboxylates employing t-butyl 2-bromo-1-methyl-1H-imidazole-5carboxylate as the starting material. As shown in Scheme 1, esterification of readily available 1methyl-1H-imidazole-5-carboxylic acid (1) 2 in a p-TsCl/pyridine/t-BuOH system 3 gave t-butyl ester 2 in 76% yield. Ester 2 was formed in only low yields by reactions of the acid chloride of 1 with t-BuOH in the presence of a base or with tBuOLi. 4 Bromination of 2 with NBS in the presence of AIBN 2b afforded bromide 3 in 92% yield.
Continuum Modeling and Analysis of the Frictional Interaction Between a CNT and a Substrate During Dragging

A simple method to determine the frictional interaction between a carbon nanotube (CNT) and a substrate is analyzed for feasibility. In this technique an atomic force microscope (AFM) tip is used to drag a CNT along a substrate. Then the deformed shape of the CNT can be viewed either with the AFM or in a scanning electron microscope. An analysis of the steady-state deformed shape allows the determination of the frictional interactions, which occurred during dragging. It is important to quantify these interactions in a variety of potential applications of nanotechnology. In one such example, a CNT based nanoswitch consists of a CNT bridging over a trench. Actuation of the CNT causes it to stretch and can lead to partial slip at the interface. This slip causes hysteresis, which has been observed in the mechanical actuation of a CNT bridge. In this paper continuum level modeling of the frictional interaction is used to determine the relationship between the steady-state deformed shape of the CNT and the frictional interaction, which occurred between the CNT and substrate during dragging. The model and analysis indicate that this method should be feasible for CNTs with aspect ratios approximately in the 100–250 range.
The Index of a Quantum Dynamical Semigroup

A numerical index is introduced for semigroups of completely positive maps of B(H) which generalizes the index ofE0-semigroups. It is shown that the index of a unital completely positive semigroup agrees with the index of its dilation to anE0-semigroup, provided that the dilation isminimal.
Chocolate Milk Consequences: A Pilot Study Evaluating the Consequences of Banning Chocolate Milk in School Cafeterias

Objectives Currently, 68.3% of the milk available in schools is flavored, with chocolate being the most popular (61.6% of all milk). If chocolate milk is removed from a school cafeteria, what will happen to overall milk selection and consumption? Methods In a before-after study in 11 Oregon elementary schools, flavored milk–which will be referred to as chocolate milk–was banned from the cafeteria. Milk sales, school enrollment, and data for daily participation in the National School Lunch Program (NSLP) were compared year to date. Results Total daily milk sales declined by 9.9% (p<0.01). Although white milk increased by 161.2 cartons per day (p<0.001), 29.4% of this milk was thrown away. Eliminating chocolate milk was also associated with 6.8% fewer students eating school lunches, and although other factors were also involved, this is consistent with the notion of psychological reactance. Conclusions Removing chocolate milk from school cafeterias may reduce calorie and sugar consumption, but it may also lead students to take less milk overall, drink less (waste more) of the white milk they do take, and no longer purchase school lunch. Food service managers need to carefully weigh the costs and benefits of eliminating chocolate milk and should consider alternative options that make white milk more convenient, attractive, and normal to choose.
Estimation with weak instruments: Accuracy of higher‐order bias and MSE approximations

Summary In this paper, we consider parameter estimation in a linear simultaneous equations model. It is well known that two-stage least squares (2SLS) estimators may perform poorly when the instruments are weak. In this case 2SLS tends to suffer from the substantial small sample biases. It is also known that LIML and Nagar-type estimators are less biased than 2SLS but suffer from large small sample variability. We construct a bias-corrected version of 2SLS based on the Jackknife principle. Using higher-order expansions we show that the MSE of our Jackknife 2SLS estimator is approximately the same as the MSE of the Nagar-type estimator. We also compare the Jackknife 2SLS with an estimator suggested by Fuller (Econometrica 45, 933–54) that significantly decreases the small sample variability of LIML. Monte Carlo simulations show that even in relatively large samples the MSE of LIML and Nagar can be substantially larger than for Jackknife 2SLS. The Jackknife 2SLS estimator and Fuller's estimator give the best overall performance. Based on our Monte Carlo experiments we conduct informal statistical tests of the accuracy of approximate bias and MSE formulas. We find that higher-order expansions traditionally used to rank LIML, 2SLS and other IV estimators are unreliable when identification of the model is weak. Overall, our results show that only estimators with well-defined finite sample moments should be used when identification of the model is weak.
Effect Of Hafnium-Incorporation On The Microstructure And Dielectric Properties Of Cobalt Ferrite Ceramics

Abstract The effect of hafnium (Hf) incorporation on the crystal structure, surface morphology, chemical composition and dielectric properties of cobalt ferrite (CoFe 2 O 4 ) is reported. Hafnium incorporated Co-ferrite (CoFe 2− x Hf x O 4 ) ceramics were prepared by varying the Hf concentration in the range of x =0.0–0.2. X-ray diffraction (XRD) studies indicate that the CoFe 2− x Hf x O 4 ceramics crystallize in inverse spinel change to structure similar to that of pure CoFe 2 O 4 . Hafnium incorporation induces lattice expansion leading to increased lattice constant from 8.374 A for pure CoFe 2 O 4 to 8.391 A for the highest Hf concentration ( x =0.2) in CoFe 2− x Hf x O 4 . Dielectric constant of CoFe 2− x Hf x O 4 ceramics is also enhanced compared to pure CoFe 2 O 4 due to the lattice distortion upon Hf incorporation. Improved dielectric properties of CoFe 2− x Hf x O 4 ceramics compared to pure CoFe 2 O 4 is attributed to the lattice distortion due to larger Hf-ions substituting for smaller Fe-ions associated structural changes with increased Hf concentration. Frequency variation of the dielectric constant shows the dispersion that can be modeled with a modified Debye's function, which considers the possibility of more than one ion, contributing to the relaxation.
Microscopic conditions favoring itinerant ferromagnetism: Hund's rule coupling and orbital degeneracy

The importance of Hund's rule coupling for the stabilization of itinerant ferromagnetism is investigated within a two-band Hubbard model. The magnetic phase diagram is calculated by finite-temperature quantum Monte-Carlo simulations within the dynamical mean-field theory. Ferromagnetism is found in a broad range of electron fillings whereas antiferromagnetism exists only near half filling. The possibility of orbital ordering at quarter filling is also analyzed.
Infrequent use and non-use of government publications by social scientists

Abstract The social scientists investigated were not, as a whole, dependent on library resources for their government information. This article probes their reasons for infrequent use and non-use of government publications held by their institutional libraries and notes some of the factors contributing to the possible underutilization of libraries' documents collections. It is believed that these findings have value beyond the institutions surveyed.
On the Stereochemical Course of Palladium-Catalyzed Cross-Coupling of Allylic Silanolate Salts with Aromatic Bromides

The stereochemical course of palladium-catalyzed cross-coupling reactions of an enantioenriched, α-substituted, allylic silanolate salt with aromatic bromides has been investigated. The allylic silanolate salt was prepared in high geometrical (Z/E, 94:6) and high enantiomeric (94:6 er) purity by a copper-catalyzed SN2′ reaction of a resolved allylic carbamate. Eight different aromatic bromides underwent cross-coupling with excellent constitutional site-selectivity and excellent stereospecificity. Stereochemical correlation established that the transmetalation event proceeds through a syn SE′ mechanism which is interpreted in terms of an intramolecular delivery of the arylpalladium electrophile through a key intermediate that contains a discrete Si−O−Pd linkage.
Coannihilation effects in supergravity and D-brane models

Abstract Coannihilation effects in neutralino relic density calculations are examined for a full range of supersymmetry parameters including large tanβ and large A0 for stau, chargino, stop and sbottom coannihilation with the neutralino. Supergravity models possessing grand unification with universal soft breaking (mSUGRA), models with nonuniversal soft breaking in the Higgs and third generation sparticles, and D-brane models with nonuniversal gaugino masses were analysed. Unlike low tanβ where m0 is generally small, stau coannihilation corridors with high tanβ are highly sensitive to A0, and large A0 allows m0 to become as large as 1 TeV. Nonuniversal soft breaking models at high tanβ also allow the opening of a new annihilation channel through the s-channel Z pole with acceptable relic density, allowing a new wide band in the m0–m1/2 plane with m1/2≳400 GeV and m0 rising to 1 TeV. The D-brane models considered possess stau coannihilations regions similar to mSUGRA, as well as small regions of chargino coannihilation. Neutralino–proton cross sections are analysed for all models and it is found that future detectors for halo wimps will be able to scan essentially the full parameter space with m1/2
An application of Guillemin–Abreu theory to a non-abelian group action

Abstract This note is a step towards demonstrating the benefits of a symplectic approach to studying equivariant Kahler geometry. We apply a local differential geometric framework from Kahler toric geometry due to Guillemin and Abreu to the case of the standard linear SU ( n ) action on C n ∖ { 0 } . Using this framework we (re)construct certain Kahler metrics from data on moment polytopes.
An axisymmetric object-based search for a flat compact dimension

A method is presented for searching for a hypertorus symmetry axis by means of the alignment of distant objects. This offers greater sensitivity than previously proposed object-based methods that rely on accurate true distances. When it is applied to the catalogue of objects with z > 1, we find no evidence for a compact dimension. We deduce a lower limit on the compact dimension size, D > 0.9 of the distance to the cosmic horizon. This is consistent with independent constraints from the recent analysis of the WMAP microwave background data.
Calcium-Catalyzed Pictet−Spengler Reactions

Pictet−Spengler reactions of m-tyramine and aldehydes produced tetrahydroisoquinolines in the presence of a catalytic amount of Ca[OCH(CF3)2]2. This reaction occurs with a variety of aryl, heteroaryl, and alkyl aldehydes, producing tetrahydroisoquinolines in high yield and with high regioselectivity. This calcium-promoted Pictet−Spengler reaction provides a mild alternative to the traditional Bronsted acids typically employed in these reactions.
Design, Synthesis, Derivatization, and Structure−Activity Relationships of Simplified, Tricyclic, 1,2,4-Trioxane Alcohol Analogues of the Antimalarial Artemisinin

Novel C4-(hydroxyalkyl)trioxanes 5d and 5e were designed and synthesized based on an understanding of the molecular mechanism of action of similar 1,2,4-trioxanes structurally related to the antimalarial natural product artemisinin (1). In vitro efficacies of these two new pairs of C4-diastereomers against chloroquine-sensitive Plasmodium falciparum support conclusions about the importance to antimalarial activity of formation of a C4 radical by a 1,5-hydrogen atom abstraction. Derivatives 6, 7, and 21 of C4 beta-substituted trioxane alcohols 4a, 5d, and 5e were prepared, each in a single-step, high-yielding transformation. Four of these new analogues, 6a-c and 7, are potent in vitro antimalarials, having 140 to 50% of the efficacy of the natural trioxane artemisinin (1).
Zero-miss-distance guidance law based on line-of-sight rate measurement only

Abstract This paper presents a high performance, simple and robust guidance method which utilizes line-of-sight (LOS) rate measurement only to yield zero-miss-distance against highly maneuvering targets. The novel guidance law adopts the basic framework of proportional navigation guidance, yet instead of using an acceleration command which is proportional to the measured LOS rate, the acceleration command is applied proportionally to an equivalent LOS rate. The equivalent LOS rate is a linear combination of the measured LOS rate and higher-order LOS rate derivatives, which are estimated from the noisy LOS rate measurement using a Kalman–Bucy filter. A considerable part of this paper is devoted to a comprehensive simulation study of the new guidance law. Deterministic simulations and Monte Carlo analyses show that excellent performance is obtained against highly maneuvering targets.
The use of a spreadsheet for sinusoidal steady-state transmission line and optics problems

It is shown how a spreadsheet on a personal computer can be used for sinusoidal steady-state transmission line and optics problems. It gives students the experience of programming the equations rather than relying on special-purpose software written by someone else. At the same time, the students do not need to expend too much effort on coding in a standard computer language, and the numerical effort is accomplished by the computer rather than a hand-held calculator. >
A numerical study of wave propagation in a confined mixing layer by eigenfunction expansions

It is well known that the growth rate of instability waves of a two‐dimensional free shear layer is reduced greatly at supersonic convective Mach numbers. In previous works, it has been shown that new wave modes exist when the shear layers are bounded by a channel due to the coupling effect between the acoustic wave modes and the motion of the mixing layer. The present work studies the simultaneous propagation of multiple stability waves using numerical simulation. It is shown here that the coexistence of two wave modes in the flow field can lead to an oscillatory growth of disturbance energy with each individual wave mode propagating linearly. This is particularly important when the growth rates of the unstable waves are small. It is also shown here that the propagation of two neutrally stable wave modes can lead to a stationary periodic structure of rms fluctuations. In the numerical simulations presented here the forced wave modes are propagating at same frequency, but with different phase velocities. In order to track the growth of each wave mode as it propagates downstream, a numerical method that can effectively detect and separate the contribution of the individual wave is given. It is demonstrated that by a least square fitting of the disturbance field with eigenfunctions the amplitude of each wave mode can be found. Satisfactory results as compared to linear theory are obtained.
A Discrete Fourier Kernel and Fraenkel's Tiling Conjecture

The set B q p,r := {⌊nq/p + r⌋ : n ∈ Z} (with integers p,q,r) is a Beatty set with density p/q. We derive a formula for the Fourier transform d B q(j) := p X n=1 e −2πij⌊nq/p+r⌋/q .
Electronic structure and anisotropic transport properties in hexagonal YPtIn and LuAgGe ternary compounds

We present anisotropic, zero applied magnetic field, temperature-dependent resistivity measurements on hexagonal, non-magnetic YPtIn and LuAgGe single crystals. For these materials the in-plane resistivity, ρab, is significantly higher than the c-axis one, ρc, with ρab/ρc≈1.4 for YPtIn and ≈4.2–4.7 for LuAgGe. The connection between the electronic structure and the anisotropic transport properties is discussed using density functional calculations that link the observed anisotropy with a specific shape of Fermi surface and anisotropy of the Fermi velocities.
Looking Beyond the Undergraduate Classroom: Factors Influencing Service Learning's Effectiveness at Improving Graduate Students’ Professional Skills

This study provides a greater understanding of which factors influence the effectiveness of service learning projects at improving graduate students’ professional skills. Data for this study was gathered from students in eight Master of Public Administration (MPA) courses taught during two semesters at a large state university. Younger students were more likely than older students to believe that their service learning project was helpful in improving their professional skills. We also find that students who spent more time working on a service learning project outside of class reported their projects were more helpful in improving their professional skills. In addition, our ANOVA analysis indicates that for projects involving group activities, students who were members of groups that worked as teams reported that their projects were more helpful in improving their professional skills than students in less cohesive groups.
Dynamic proton-induced two-stage emission switching in donor-functionalized bis(dehydrobenzo[n]annuleno)benzenes and 1,2,4,5-tetrakis(phenylethynyl)benzene

Abstract Titration of three electron donor-functionalized bis(dehydrobenzo[n]annuleno)benzenes and a corresponding acyclic 1,2,4,5-tetrakis(phenylethynyl)benzene derivative with trifluoroacetic acid in CH2Cl2 resulted in two-stage emission switching behavior in which initial acidification caused bathochromic shifts, followed by dramatic hypsochromic shifts upon further addition of acid. Differences in the various spectra are rationalized by structure and chromophore architecture. The results indicate independent manipulation of frontier molecular orbital energy levels by stepwise ion addition, therefore suggesting transient and tunable intramolecular charge transfer systems upon partial protonation.
Nonexponential decay in relaxation phenomena

A variety of considerations from different points of view including non-Markovian stochastic processes, basic quantum mechanics, and a mechanism based on condensed matter physics, all lead to the fractional exponential decay at long times in relaxation processes. Implications of this decay law and its verifiable predictions in a broad range of phenomena in condensed matter physics are pointed out.
Synthesis, Equilibration, and Coupling of 4-Lithio-1,3-dioxanes: Synthons for syn- and anti-1,3-Diols

Configurationally defined α-alkoxylithium reagents were prepared by reductive lithiation of 4-(phenylthio)-1,3-dioxanes. A new and more general synthesis of 4-(phenylthio)-1,3-dioxanes has been developed on the basis of the reduction and in situ acetylation of 1,3-dioxan-4-ones. For each of the substitution patterns examined (23a−d), reductive lithiation gave the axial alkyllithium (24a−d) with 99:1 stereoselectivity. Equilibrations of these alkyllithium reagents were possible with unhindered substrates to give the equatorial alkyllithiums 26a and 26b with excellent stereoselectivities. The more hindered axial alkyllithium reagents (24c, 24d) did not equilibrate efficiently. The equilibrium between alkyllithium reagents 24c and 26c strongly favors the equatorial isomer 26c. The inefficient equilibration with this hindered substrate is attributed to a slow rate of equilibration rather than insufficient driving force. These alkyllithium reagents could be coupled with a variety of electrophiles with retentio...
Carbanion addition to a metalated acetaldehyde. A new regiospecific alkene synthesis

Abstract The reaction of 2-[(dicarbonyl)(η 5 -cyclopentadienyl)iron]acetaldehyde with organolithium and Grignard reagents results in efficient addition to the aldehyde carbonyl. The intermediate alkoxides have been treated with tetrafluoroboric acid to give high yields of isolated η 2 -alkene complexes of the dicarbonyl(η 5 -cyclopentadienyl)iron cation. Using this procedure the following alkenes were produced as complexed ligands to iron in 50–90% yield: propene, 1-hexene, 3-methyl-1-pentene, 3,3-dimethyl-1-butene, 1,3-butadiene, and styrene.
Evidence for S-duality in N = 4 supersymmetric gauge theory

Abstract Using D-brane techniques, we compute the spectrum of stable BPS states in N = 4 supersymmetric gauge theory, and find it is consistent with Montonen-Olive duality.
Immune mechanisms in vitiligo

V itiligo is a caused by cytes. As disfiguring disease of the skin that is the selective destruction of melanoa result, white patches of complete depigmentation appear on the skin. The disease is asymptomatic and does not adversely affect survival; however, it can cause severe disfigurement, lead to serious psychological stresses, and interfere with employment.’ The striking aspect of vitiligo is that the damage it causes is highly selective; it is almost entirely restricted to melanocytes. Vitiligo normally begins with small areas of complete depigmentation. There is usually no preceding inflammation, and the lesions themselves are asymptnmatic. The disease progresses with enlargement of existing lesions and appearance of new lesions. Spontaneous repigmentation, usually only partial, occurs in some patients. When repigmentation occurs, it often arises from hair follicles, suggesting that melanocytes in this location are relatively spared. Vitiligo occurs in several animals including Smyth (formerly called DAM) chickens; Belgian Tervuren dogs; Siamese cats; Arabian, Lipizzaner, and Camargue horses; and Sinclair miniswine.J---‘7 These provide experimental models in which the cause of the disease can be studied experimentally. Vitiligo is familial in some patients and can occur in twins,:suggesting that in some cases it results from an inherent genetic defect that expresses itself in melanocytes. Mt;m4 however, some favor a polygenie mode of inheritance. 1” Several HLA abnormalities ha\re been associated with vitiligo, including associations with Dr4, B13, BW35, and A30.“,“,“-‘”
A Parallel Incompressible Flow Solver Package with a Parallel Multigrid Elliptic Kernel

The development and applications of a parallel, time-dependent incompressible Navier?Stokes flow solver and a parallel multigrid elliptic kernel are described.The flow solver is based on a second-order projection method applied to a staggered finite-difference grid. The multigrid algorithms inplemented in the parallel elliptic kernel, which is needed by the flow solver, are V-cycle and full V-cycle schemes. A grid-partition strategy is used in the parallel implementations of both the flow solver and the multigrid elliptic kernel on all fine and coarse grids. Numerical experiments and parallel performance tests show the parallel solver package is numerically stable, physically robust, and computationally efficient. Both the multigrid elliptic kernel and the flow solver scale very well to a large number of processors on Intel Paragon and Cray T3D for computations with moderate granularity. The solver package has been carefully designed and coded so that it can be easily adapted to solving a variety of interesting two- and three-dimensional flow problems. The solver package is portable to parallel systems that support MPI, PVM, and NX for interprocessor communications.
Optimal Decompositions of Translations of L 2 -Functions

In this paper we offer a computational approach to the spectral function for a finite family of commuting operators, and give applications. Motivated by questions in wavelets and in signal processing, we study a problem about spectral concentration of integral translations of functions in the Hilbert space \(L^2({\mathbb{R}}^n)\). Our approach applies more generally to families of n arbitrary commuting unitary operators in a complex Hilbert space \({\mathcal{H}}\), or equivalent the spectral theory of a unitary representation U of the rank-n lattice \({\mathbb{Z}}^n\) in \({\mathbb{R}}^n\). Starting with a non-zero vector \({\psi}\,{\in}\,{\mathcal{H}}\), we look for relations among the vectors in the cyclic subspace in \({\mathcal{H}}\) generated by ψ. Since these vectors \(\{U(k)\psi|k\,{\in}\,{\mathbb{Z}}^n\}\) involve infinite “linear combinations,” the problem arises of giving geometric characterizations of these non-trivial linear relations. A special case of the problem arose initially in work of Kolmogorov under the name L2-independence. This refers to infinite linear combinations of integral translates of a fixed function with l2-coefficients. While we were motivated by the study of translation operators arising in wavelet and frame theory, we stress that our present results are general; our theorems are about spectral densities for general unitary operators, and for stochastic integrals.
The number of publications used as a metric of the NOAO WIYN queue experiment

Abstract We use the number of papers published in 1998 and 1999 to test the hypothesis that the queue observing mode at WIYN leads to a significantly higher scientific throughput than classical mode observing. We use the papers published from the 4-m, and papers published from the non-queue WIYN time as controls, requiring only that the data be obtained after 1996 August 1, at which time the WIYN queue was in its third full semester of operation, and the WIYN instruments functional and stable. The number of papers published from the queue data is actually 1.5 times smaller (on a per night basis) than from the 4-m, and roughly comparable to (but lower than) the number published from non-queue WIYN time. Thus neither comparison offers any support for the hypothesis that queue leads to a higher scientific throughput. The number of papers is relatively small, but the statistics are sufficiently robust to reject the possibility that queue observing at WIYN leads to a factor of 1.5 enhancement in publication rate with a 99.3% confidence in comparison to the 4-m, and with an 89.9% confidence in comparison with non-queue WIYN time. We consider several explanations, and urge that other observatories planning to employ the queue mode include some controls to provide an objective evaluation of its success.
The late time evolution of gamma-ray bursts: ending hyperaccretion and producing flares

We consider the properties of a hyperaccretion model for gamma-ray bursts (GRBs) at late times when the mass supply rate is expected to decrease with time. We point out that the region in the vicinity of the accretor and the accretor itself can play an important role in determining the rate of accretion, and its time behaviour, and ultimately the energy output. Motivated by numerical simulations and theoretical results, we conjecture that the energy release can be repeatedly stopped and then restarted by the magnetic flux accumulated around the accretor. We propose that the episode or episodes when the accretion resumes correspond to X-ray flares discovered recently in a number of GRBs.
Optimization of data center room layout to minimize rack inlet air temperature

In a typical raised floor data center with alternating hot and cold aisles, air enters the front of each rack over the entire height of the rack. Since the heat loads of data processing equipment continue to increase at a rapid rate, it is a challenge to maintain the temperature of all the racks within the stated requirement. A facility manager has discretion in deciding the data center room layout, but a wrong decision will eventually lead to equipment failure. There are many complex decisions to be made early in the design as the data center evolves. Challenges occur such as optimizing the raised floor plenum, floor tile placement, minimizing the data center local hot spots, etc. These adjustments in configuration affect rack inlet air temperatures, which is one of the important keys to effective thermal management. In this paper, a raised floor data center with 12 kW racks is considered. There are four rows of racks with alternating hot and cold aisle arrangement. Each row has six racks installed. Two air-conditioning units supply chilled air to the data center through the pressurized plenum. Effect of plenum depth, floor tile placement, and ceiling height on the rack inlet air temperature is discussed. Plots will be presented over the defined range. A multivariable approach to optimize data center room layout to minimize the rack inlet air temperature is proposed. Significant improvement over the initial model is shown by using a multivariable design optimization approach.
Radar measurements of dynamics and layering processes in the 80–150 km region at Arecibo

Abstract The Arecibo Initiative in Dynamics of the Atmosphere (AIDA) '89 and Overture to AIDA campaigns yielded 35 days, in four periods, of low-latitude Incoherent Scatter Radar (ISR) power profiles and derived electron concentration results. These results, along with results from the sodium lidar, have been used to study 80–150 km ion layers, the sodium layer, and the complex of dynamical processes involved in the formation of both ion and neutral sodium layers. Features of the ion layer motions reveal a wide range of dynamical processes ranging from multiday period waves, tides, and Acoustic Gravity Waves (AGWs) to geomagnetic storm effects and evidence of coupled neutral sodium and ion layering processes. Joint ISR and sodium lidar results point to localized instabilities in the combined tidal and AGW wind field and to the origins of sporadic E and sporadic sodium layers.