cssi/SciSciGPT-SciSciNet huggingface dataset:
Perceived discontinuities and constructed continuities in virtual work

ABSTRACT Boundaries such as time, distance, organization, and culture have been a useful conceptual tool for researchers to unpack changes in the virtual work environment, moving from a dichotomous perspective that contrasts face-to-face (FTF) and virtual work to a more nuanced hybrid perspective. However, researchers may tacitly assume that all members of a virtual team and virtual teams collectively will respond to a boundary in a similar way. We posit instead that boundaries are a dynamic phenomenon and may have different consequences under different circumstances. We offer organizational discontinuity theory as a tool for more focused investigation of the virtual work environment. Discontinuities and continuities describe the setting in which individuals in a virtual team operate, both actual work practices and the perceptions of the individuals in the virtual work environment. The terms offer a starting point to identify and understand what may otherwise seem to be paradoxical differences in how virtual team members respond to boundaries.
Highly N2-selective palladium-catalyzed arylation of 1,2,3-triazoles.

Highly N2-selective arylation of 4,5-unsubstituted and 4-substituted 1,2,3-triazoles was achieved for the first time by Pd/L1 catalyst system. A wide range of N2-aryl-1,2,3-triazoles were prepared from aryl bromides, chlorides and triflates with excellent (95–99%) N2-selectivity. DFT calculations suggest that formation of N2-arylated 1,2,3-triazoles is favored kinetically.
High Column Densities and Low Extinctions of Gamma-Ray Bursts: Evidence for Hypernovae and Dust Destruction

We analyze a complete sample of γ-ray burst afterglows and find X-ray evidence for high column densities of gas around them. The column densities are in the range 1022-1023 cm-2, which is right around the average column density of Galactic giant molecular clouds. We also estimate the cloud sizes to be 10-30 pc, implying masses 105 M☉. This strongly suggests that γ-ray bursts lie within star-forming regions and therefore argues against neutron star mergers and for collapses of massive stars as their sources. The optical extinctions, however, are 10-100 times smaller than expected from the high column densities. This confirms theoretical findings that the early hard radiation from γ-ray bursts and their afterglows can destroy the dust in their environment, thus carving a path for the afterglow light out of the molecular cloud. Because of the self-created low extinction and location in star-forming regions, we expect γ-ray bursts to provide a relatively unbiased sample of high-redshift star formation. Thus, they may help resolve what is the typical environment of high-redshift star formation.
Structural Elucidation with NMR Spectroscopy: Practical Strategies for Organic Chemists

Practical strategies for the structural elucidation of small organic molecules are described for typical organic chemists. The analysis of an unknown is divided into three stages. First, structural connectivity is deduced from through-bond correlation experiments. Next, the relative stereochemistry is determined from NOE correlations and coupling constants (both proton–proton and proton–carbon). Finally, the proposed structure is verified by a careful inspection of all of the observed data. Tactics for the management of overlapping peaks, low sample concentrations, and high molecular weights are also described. This approach is illustrated by the step-by-step analyses of a simple test compound, menthol, and a complex polycyclic natural product, salvinorin A. Detailed procedures and sample data for menthol are provided as a practical tutorial. This will enable organic chemists to elucidate a wide range of complex structures by using modern NMR spectroscopic experiments.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Performance of hybrid-ARQ in block-fading channels: A fixed outage probability analysis

This paper studies the performance of hybrid-ARQ (automatic repeat request) in Rayleigh block-fading channels. The long-term average transmitted rate is analyzed in a fast-fading scenario where the transmitter only has knowledge of channel statistics, and, consistent with contemporary wireless systems, rate adaptation is performed such that a target outage probability (after a maximum number of H-ARQ rounds) is maintained. H-ARQ allows for early termination once decoding is possible, and thus is a coarse, and implicit, mechanism for rate adaptation to the instantaneous channel quality. Although the rate with H-ARQ is not as large as the ergodic capacity, which is achievable with rate adaptation to the instantaneous channel conditions, even a few rounds of H-ARQ make the gap to ergodic capacity reasonably small for operating points of interest. Furthermore, the rate with H-ARQ provides a significant advantage compared to systems that do not use H-ARQ and only adapt rate based on the channel statistics.
Hard sphere dynamics for normal and granular fluids.

: A fluid of N smooth, hard spheres is considered as a model for normal (elastic collision) and granular (inelastic collision) fluids. The potential energy is discontinuous for hard spheres so that the pairwise forces are singular and the usual forms of Newtonian and Hamiltonian mechanics do not apply. Nevertheless, particle trajectories in the N particle phase space are well defined and the generators for these trajectories can be identified. The first part of this presentation is a review of the generators for the dynamics of observables and probability densities. The new results presented in the second part refer to applications of these generators to the Liouville dynamics for granular fluids. A set of eigenvalues and eigenfunctions of the generator for this Liouville dynamics system is identified in a special stationary representation. This provides a class of exact solutions to the Liouville equation that are closely related to hydrodynamics for granular fluids.
Spatial Sensing and Cognitive Radio Communication in the Presence of a $K$ -User Interference Primary Network

We study the feasibility of cognitive radio (CR) communication in the presence of a $K$ -user multi-input multi-output (MIMO) interference channel as the primary network. Assuming that the primary interference network has unused spatial degrees of freedom (DoFs) , we first investigate the sufficient condition on the number of antennas at the secondary transmitter under which the secondary system can communicate while causing no interference to the primary receivers. We show that, to maximize the benefit, the secondary transmitter should have at least the same number of antennas as the spatial DoFs of the primary system. We then derive the secondary precoding and decoding matrices to have zero interference leakage into the primary network while the signal-to-interference plus noise ratio (SINR) at the secondary receiver is maximized. As the success of the secondary communication depends on the availability of unused DoFs, we then propose a fast sensing method based on the eigenvalue analysis of the received signal covariance matrix to determine the availability of unused DoFs or equivalently spatial holes. Since the proposed fast sensing method cannot identify the indices of inactive primary streams, we also provide a fine sensing method based on the generalized likelihood ratio test (GLRT) to decide the absence of individual primary streams. Simulation results show that the proposed CR sensing and transmission scheme can, in practice, provide a significant throughput while causing no interference to the primary receivers, and that the sensing detects the spatial holes of the primary network with high detection probability.
The stability region of the finite-user slotted ALOHA protocol

A version of the discrete-time slotted ALOHA protocol operating with finitely many buffered terminals is considered. The stability region is defined to be the set of vectors of arrival rates lambda =( lambda /sub 1/,. . ., lambda /sub M/) for which there exists a vector of transmission probabilities such that the system is stable. It is assumed that arrivals are independent from slot to slot, and the following model for the arrival distribution in a slot is assumed: the total number of arrivals in any slots is geometrically distributed, with the probability that such an arrival is at node i being lambda /sub i/ times ( Sigma /sub k/ lambda /sub k/)/sup -1/, independent of the others. With this arrival model, it is proven that the closure of the stability region of the protocol is the same as the closure of the Shannon capacity region of the collision channel without feedback, as determined by J.L. Massey and P. Mathys (1985). At present it is not clear if this result depends on the choice of arrival distribution. The basic probabilistic observation is that the stationary distribution and certain conditional distributions derived from it have positive correlations for bounded increasing functions. >
Synthesis, resolution and crystallographic characterization of a new C2-symmetric planar-chiral bipyridine ligand: application to the catalytic enantioselective cyclopropanation of olefins

The synthesis of a new C2-symmetric planar-chiral bipyridine ligand is described, as well as its application to the enantioselective CuI-catalyzed cyclopropanation of olefins.
Synthesis of a uranyl persulfide complex and quantum chemical studies of formation and topologies of hypothetical uranyl persulfide cage clusters.

The compound Na4[(UO2)(S2)3](CH3OH)8 was synthesized at room temperature in an oxygen-free environment. It contains a rare example of the [(UO2)(S2)3]4– complex in which a uranyl ion is coordinated by three bidentate persulfide groups. We examined the possible linkage of these units to form nanoscale cage clusters analogous to those formed from uranyl peroxide polyhedra. Quantum chemical calculations at the density functional and multiconfigurational wave function levels show that the uranyl–persulfide–uranyl, U–(S2)–U, dihedral angles of model clusters are bent due to partial covalent interactions. We propose that this bent interaction will favor assembly of uranyl ions through persulfide bridges into curved structures, potentially similar to the family of nanoscale cage clusters built from uranyl peroxide polyhedra. However, the U–(S2)–U dihedral angles predicted for several model structures may be too tight for them to self-assemble into cage clusters with fullerene topologies in the absence of other u...
A path guessing game with wagering

We consider a two-player game in which the first player (the Guesser) tries to guess, edge-by-edge, the path that second player (the Chooser) takes through a directed graph. At each step, the Guesser makes a wager as to the correctness of her guess and receives a payoff proportional to her wager if she is correct. We derive optimal strategies for both players for various classes of graphs, and we describe the Markov-chain dynamics of the game under optimal play. These results are applied to the infinite-duration Lying Oracle Game, in which the Guesser must use information provided by an unreliable Oracle to predict the outcome of a coin toss.
Synthesis of Multilevel Converters Based on Single- and/or Three-Phase Converter Building Blocks

This paper synthesized a family of multilevel converters that is constructed by using multiple well-developed single- and/or three-phase converter building blocks. The resulting advantages include a modular structure that leads to convenient construction and maintenance as well as easy extension to higher voltage levels. One successful example from this family is the cascaded H-bridge converter, which is now widely used for volt-amperes reactive (VAR) compensation and motor drive applications due to its many advantages. Another emerging member is the Hexagram converter, composed of six interconnected three-phase converter modules, which has many eminent features such as lowered component count and lowered dc energy storage requirement compared to the cascaded H-bridge converter, and thus, is a promising candidate for high-power applications.
Simulating Non-small Cell Lung Cancer with a Multiscale Agent-based Model

The epidermal growth factor receptor (EGFR) is frequently overexpressed in many cancers, including non-small cell lung cancer (NSCLC). In silico modeling is considered to be an increasingly promising tool to add useful insights into the dynamics of the EGFR signal transduction pathway. However, most of the previous modeling work focused on the molecular or the cellular level only, neglecting the crucial feedback between these scales as well as the interaction with the heterogeneous biochemical microenvironment. We developed a multiscale model for investigating expansion dynamics of NSCLC within a two-dimensional in silico microenvironment. At the molecular level, a specific EGFR-ERK intracellular signal transduction pathway was implemented. Dynamical alterations of these molecules were used to trigger phenotypic changes at the cellular level. Examining the relationship between extrinsic ligand concentrations, intrinsic molecular profiles and microscopic patterns, the results confirmed that increasing the amount of available growth factor leads to a spatially more aggressive cancer system. Moreover, for the cell closest to nutrient abundance, a phase-transition emerges where a minimal increase in extrinsic ligand abolishes the proliferative phenotype altogether. Our in silico results indicate that in NSCLC, in the presence of a strong extrinsic chemotactic stimulus (and depending on the cell's location) downstream EGFR-ERK signaling may be processed more efficiently, thereby yielding a migration-dominant cell phenotype and overall, an accelerated spatio-temporal expansion rate.
THE UNEVEN RESULTS OF INSTITUTIONAL CHANGES IN CENTRAL AND EASTERN EUROPE: THE ROLE OF CULTURE

The main objective of this essay is to show that the process of transition from socialism to capitalism in Central and Eastern Europe is a cultural problem rather than a technical one. In pursuing that objective I analyze two interrelated issues. First, analysis shows why and how cultural differences in Central and Eastern Europe have, via transaction costs specific to the process of transition, specific and predictable effects on the results of institutional restructuring, and, consequently, on economic performance. Second, I argue that spontaneous changes in the prevailing culture could, under a set of credible and stable formal rules of the game, help to close a gap between the culture supportive of capitalism and the prevailing culture in Central and Eastern Europe.My colleague and friend Fred Fransen made two major contributions to this essay: he helped me identify numerous inconsistencies in the essay, and he changed a number of my perceptions on the relationship between culture and economic performance. James Buchanan, Ljubo Madzar, Henry Manne, Milic Milovanovic, and Katarina Ott gave me useful suggestions and comments on earlier drafts. I am grateful to Victor Vanberg and Ulrich Witt for the opportunity to discuss this essay with their colleagues and students at the University of Freiburg and Max Planck Institute in Jena, Germany.
The Integrity of ACSR Full Tension Splice Connector at Higher Operation Temperature

Due to the increase in power demand and limited investment in new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than those used for the original design criteria. This has led to the accelerated aging and degradation of splice connectors, which have been manifested by the formation of hotspots that have been revealed by infrared imaging during inspection. The implications of connector aging is twofold: 1) significant increase in resistivity of the splice connector (i.e., less efficient transmission of electricity) and 2) significant reduction in the connector clamping strength, which could ultimately result in separation of the power transmission line at the joint. Therefore, the splice connector appears to be the weakest link in the electric power transmission lines. This paper presents a protocol for integrating analytical and experimental approaches to evaluate the integrity of a full tension single-stage splice connector assembly.
CCD Base Line Subtraction Algorithms

High statistics astronomical surveys require photometric accuracy on a few percent level. The accuracy of sensor calibration procedures should match this goal. The first step in calibration procedures is the base line subtraction. The accuracy and robustness of different base line subtraction techniques used for Charge Coupled Device (CCD) sensors are discussed.
Pre-Election Polling: Identifying Likely Voters Using Iterative Expert Data Mining

One often-noted difficulty in pre-election polling is the iden tification of likely voters. Our objective is to build a likely voter model for presidential elections that efficiently balances accuracy and number of questions used. We employ the Iterative Expert Data Mining tech nique and data from the American National Election Studies to identify a small number of survey questions that can be used to classify likely vot ers while maintaining or surpassing the accuracy rates of other models. Specifically, we propose two survey items that together correctly classify 78 percent of respondents as voters or nonvoters over a multielection, multidecade period. We argue that our proposed model compares favor ably to competing models by capturing the successful elements of those models while ignoring other elements that constrain identification. We end by suggesting that our model offers a new approach to identifying and evaluating likely voters that may maintain or increase accuracy without also increasing cost.
Unwinding Forward Correctability

A state-machine formulation is given for forward correct ability in event systems, to provide a type of unwinding result for this information flow security property. We show also how regular expression notation provides an easy mechanical tool for verifying forward correct ability for small systems, which is necessary for the effective presentation of examples and exercises.
Diurnal and Semidiurnal Variations in Earth Orientation Determined from Lageos Laser Ranging

The dynamical rotational equations of the solid Earth provide a useful global integrator of a variety of forcing functions of geophysical interest, including atmospheric mass and wind distribution, and oceanic mass and current distribution. Since the solid Earth/ocean/atmosphere is a coupled dynamical system, changes in these variables, which are frequently difficult to measure in a global sense, lead to changes in the more directly measurable quantity of the rotational axis position and rotation rate of the solid Earth. Satellite laser ranging (SLR) has demonstrated the ability to monitor variations in the both the orientation of the Earth’s spin axis and the rotation rate at the few centimeter level over the past decade (Eanes et al., 1989; Eanes and Watkins, 1990, 1991; IERS, 1989, 1992). The quality of the estimates of polar motion and UT1 have, naturally, improved with time to the current level of 0.5 mas, and the temporal resolution has likewise increased to the current 3-day length.
Modeling Interconnect Variability Using Efficient Parametric Model Order Reduction

Assessing IC manufacturing process fluctuations and their impacts on IC interconnect performance has become unavoidable for modern DSM designs. However, the construction of parametric interconnect models is often hampered by the rapid increase in computational cost and model complexity. In this paper we present an efficient yet accurate parametric model order reduction algorithm for addressing the variability of IC interconnect performance. The efficiency of the approach lies in a novel combination of low-rank matrix approximation and multi-parameter moment matching. The complexity of the proposed parametric model order reduction is as low as that of a standard Krylov subspace method when applied to a nominal system. Under the projection-based framework, our algorithm also preserves the passivity of the resulting parametric models.
Mass fall-back and accretion in the central engine of gamma-ray bursts

We calculate the rate of in-fall of stellar matter on an accretion disc during the collapse of a rapidly rotating massive star and estimate the luminosity of the relativistic jet that results from accretion on to the central black hole. We find that the jet luminosity remains high for about 102 s, at a level comparable to the typical luminosity observed in gamma-ray bursts (GRBs). The luminosity then decreases rapidly with time for about ∼103 s, roughly as ∼t−3; the duration depends on the size and rotation speed of the stellar core. The rapid decrease of the jet power explains the steeply declining X-ray flux observed at the end of most long-duration GRBs. Observations with the Swift satellite show that, following the steep decline, many GRBs exhibit a plateau in the X-ray light curve (XLC) that lasts for about 104 s. We suggest that this puzzling feature is due to continued accretion in the central engine. A plateau in the jet luminosity can arise when the viscosity parameter α is small, ∼10−2 or less. A plateau is also produced by continued fall-back of matter – either from an extended stellar envelope or from material that failed to escape with the supernova ejecta. In a few GRBs, the XLC is observed to drop suddenly at the end of the plateau phase, while in others the XLC declines more slowly as ∼t−1−t−2. These features arise naturally in the accretion model depending on the radius and mean specific angular momentum of the stellar envelope. The total energy in the disc-wind accompanying accretion is found to be about 1052 erg. This is comparable to the energy observed in supernovae associated with GRBs, suggesting that the wind might be the primary agent responsible for the explosion. The accretion model thus provides a coherent explanation for the diverse and puzzling features observed in the early XLC of GRBs. It might be possible to use this model to invert gamma-ray and X-ray observations of GRBs and thereby infer basic properties of the core and envelope of the GRB progenitor star.
Introduction: The International Diffusion of Liberalism

Political scientists, sociologists, and economists have all sought to ana- lyze the spread of economic and political liberalism across countries in recent decades+ This article documents this diffusion of liberal policies and politics and proposes four distinct theories to explain how the prior choices of some countries and inter- national actors affect the subsequent behavior of others: coercion, competition, learn- ing, and emulation+ These theories are explored empirically in the symposium articles that follow+ The goal of the symposium is to bring quite different and often isolated schools of thought into contact and communication with one another, and to define common metrics by which we can judge the utility of the contending approaches to diffusion across different policy domains+
A low-power DCT core using adaptive bitwidth and arithmetic activity exploiting signal correlations and quantization

This work describes the implementation of a discrete cosine transform (DCT) core compression system targetted to low-power video (MPEG2 MP@ML) and still-image (JPEG) applications. It exhibits two innovative techniques for arithmetic operation reduction in the DCT computation context along with standard voltage scaling techniques such as pipelining and parallelism. The first method dynamically minimizes the bitwidth of arithmetic operations in the presence of data spatial correlation. The second method trades off power dissipation and image compression quality (arithmetic precision). The chip dissipates 4.38 mW at 14 MHz and 1.56 V.
THE GROTHENDIECK CONSTANT IS STRICTLY SMALLER THAN KRIVINE’S BOUND

The (real) Grothendieck constant , perform better than the ubiquitous random hyperplane technique. By establishing the usefulness of higher-dimensional rounding schemes, this fact has consequences in approximation algorithms. Specifically, it yields the best known polynomial-time approximation algorithm for the Frieze–Kannan Cut Norm problem, a generic and well-studied optimization problem with many applications.
Efficient and practical synthesis of d-cyclopent-2-enone, the key intermediate for the synthesis of carbocyclic nucleosides

Abstract An efficient and practical method for the synthesis of (4R,5R)-4,5-O-isopropylidene-cyclopent-2-enone was developed from d -ribose by using a ring-closing metathesis reaction.
The interleukin 2 receptor.

Publisher Summary Although it was assumed initially that the various activities found in conditioned media were solely produced by lymphocytes, this idea was broadened subsequently to allow for activities that are produced by nonlymphoid cells, and the term cytokine is now sometimes used. A pivotal advance that enabled new experimental approaches to these problems came when techniques were developed to culture normal T cells for prolonged periods. For lymphokine experiments, the use of cloned cells instead of a heterogeneous population of target cells was the breakthrough needed for unambiguous interpretations of experimental results. Thus, the first description of the biologic properties of the lymphokine responsible for T cell growth occurred only after there was a development of a T cell growth factor (TCGF) assay using cloned cytolytic T cell lines. Clues as to the mechanism were uncovered during the course of the very first experiments on the biologic characteristics of interleukin 2 (IL-2), as the TCGF is presently known, because it was noted that the activity disappeared from the culture media as the cell density increased. The authentic, high-affinity IL-2 receptor that functions to signal T cell cycle progression is composed of at least two distinct polypeptide chains, each of which contains an IL-2 binding site.
Catalytic olefin hydrogenation using N-heterocyclic carbene–phosphine complexes of iridium

N-heterocyclic carbene–phosphine complexes of iridium have been synthesized and examined for their performance in the catalytic homogeneous hydrogenation of a range of olefins; the reaction was further explored using para-hydrogen induced polarization (PHIP) 1H NMR.
From petri nets to linear logic

Linear logic has recently been introduced by Girard as a logic of actions that seems well suited for concurrent computation. In this paper, we establish a systematic correspondence between Petri nets, linear logic theories, and linear categories. Such a correspondence sheds new light on the relationships between linear logic and concurrency, and on how both areas are related to category theory. Categories are here viewed as concurrent systems the objects of which are states, and the morphisms of which are transitions. This is an instance of the Lambek-Lawvere correspondence between logic and category theory that cannot be expressed within the more restricted framework of the Curry-Howard correspondence.
Chondroblastoma of the Clivus: Case Report and Review

Background and Importance Chondroblastoma is a benign primary bone tumor that typically develops in the epiphyses of long bones. Chondroblastoma of the craniofacial skeleton is extremely rare, with most cases occurring in the squamosal portion of the temporal bone. In this report, we describe the first case of chondroblastoma of the clivus presenting with cranial neuropathy that was treated with endoscopic endonasal resection. We review the literature on craniofacial chondroblastomas with particular emphasis on extratemporal lesions. Case Presentation A 27-year-old woman presented with severe headache, left facial dysesthesias, and diplopia. Physical examination revealed hypesthesia in the left maxillary nerve dermatome, and complete left abducens nerve palsy. Imaging demonstrated an expansile intraosseous mass originating in the upper clivus with extension superiorly into the sella turcica and laterally to involve the medial wall of the left cavernous sinus. The tumor was completely resected via an endoscopic endonasal approach, with postoperative improvement in lateral gaze palsy. Histopathology was consistent with chondroblastoma. Conclusion Chondroblastoma is a rare tumor of the craniofacial skeleton that should be included in the differential diagnosis of an osteolytic lesion of the clivus. Complete surgical resection remains the mainstay of treatment.
Nutrient, Labor, Energy and Economic Evaluations of Two Farming Systems in Iowa

Farmer-researcher partnerships are needed to ensure soil and crop management practices are productive, environmentally safe, economically sound, and socially acceptable. We developed a farmer-researcher partnership to compare nutrient, labor, energy, and economic budgets for two conventional 40-acre fields where a 2-yr corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation is used with those for two adjacent fields where a 5-yr corn, soybean, corn, oat (Avena sativa L.), and hay rotation is used. Conventional fields received commercial fertilizer and herbicides. Alternative fields received no herbicides and a mixture of animal manure plus municipal sewage sludge as the primary nutrient source. A 10-yr nutrient budget suggests that N 2 fixation would have to provide at least 53% of the N removed by soybean grain to prevent depletion of soil organic matter or other soil N sources from conventional fields. By assuming similar amounts of N fixation in the alternative fields, we show that 962 lb N/acre, 244 lb P/acre, and 844 lb K/acre were applied (or fixed) in excess of crop removal. Soil-test P, K, and organic matter changes reflect these applications. More fieldwork hours per acre per year were required to handle manure, avoid using herbicides, and harvest hay than to use conventional practices. Energy budgets were dependent on whether nutrients in the manure plus municipal sludge were considered as (i) an input cost for the crop, or (ii) a disposal cost that should be charged against an animal enterprise. Economic budgets were dependent on assumptions made regarding how to account for management costs. Overall, developing farmer-researcher partnerships was an effective method for evaluating alternative farming systems.
Holographic Optical System For Aberration Corrections In Laser Doppler Velocimetry

An optical system containing multifaceted holographic optical elements (HOEs) has been developed to correct for aberrations introduced by nonflat windows in laser Doppler velocimetry. The multifacet aberration correction approach makes it possible to record on one plate many sets of adjacent HOEs that address different measurement volume locations. By using 5-mm-diameter facets, it is practical to place 10-20 sets of holograms on one 10 x 12.5-cm plate, so that the procedure of moving the entire optical system to examine different locations may not be necessary. The holograms are recorded in dichromated gelatin and therefore are nonabsorptive and suitable for use with high-power argon laser beams. Low f-number optics coupled with a 90-percent efficient distortion-correcting hologram in the collection side of the system yield high optical efficiency.
Impacts of BSE and Avian Influenza on U.S. Meat Demand

Jianhong E. Mu, Bruce A McCarl & David Bessler 1 Postdoc Scholar, Department of Agriculture and Resource Economics, Oregon State University, Jianhong.mu@oregonstate.edu 2 Distinguished professor, Department of Agricultural Economics, Texas A&M University, College Station, TX, 77840, mccarl@tamu.edu 3 Regent professor, Department of Agricultural Economics, Texas A&M University, College Station, TX, 77840, d-bessler@tamu.edu
Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis.

Background Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)–derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures. Methods A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index ( I 2 ), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression. Results The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from −16.7% to −23.6% (mean, −20.2%; 95% CI, −19.5% to −20.8%), GCS varied from −12.9% to −31.4% (mean, −22.3%; 95% CI, −19.9% to −24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of −20.4% (95% CI, −19.8% to −21.7%). Twenty-three studies reported circumferential strain (mean, −20.3%; 95% CI, −19.4% to −21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient ( P I 2 > 94% and P P = .40). Conclusions This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was –20.2% (95% CI, −19.5% to −20.8%), mean GCS was −22.3% (95% CI, −19.9% to −24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well.
Cultural dynamics and marketing strategies for emerging markets: characterization of group subcultures and consumption preferences

Emerging markets (EMs) collectively represent more than half of the world population with rapidly increasing purchasing power. In spite of recent advances, consumer research of EMs is limited in scope and concept development and thus inadequately reflects EM realities in comparison with theories developed in and for the Western societies. Characterization of the dynamic changes in cultural ecology in EMs became an important area in need of conceptual and empirical research. The present study introduces a new conceptual framework—Taxonomy of Cultural Ecology—to better explain the cultural dynamics in EMs and predict changes in consumption preferences at a social group level—a key target for effective marketing strategies. Conceptual findings are connected with managerial implications relevant to marketing strategists, advertising managers and leaders of multinational corporations.
Direct enantioselective conjugate addition of carboxylic acids with chiral lithium amides as traceless auxiliaries.

Michael addition is a premier synthetic method for carbon–carbon and carbon–heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B.
Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry

Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached -90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent. Graphical Abstract ᅟ.
The Relative Volatility of Commodity Prices: A Reappraisal

This paper studies the volatility of commodity prices on the basis of a large dataset of monthly prices observed in international trade data from the United States over the period 2002 to 2011. The conventional wisdom in academia and policy circles is that primary commodity prices are more volatile than those of manufactured products, although most of the existing evidence does not actually attempt to measure the volatility of prices of individual goods or commodities. The literature tends to focus on trends in the evolution and volatility of ratios of price indexes composed of multiple commodities and products. This approach can be misleading. Indeed, the evidence presented in this paper suggests that on average prices of individual primary commodities are less volatile than those of individual manufactured goods. However, the challenges of managing terms of trade volatility in developing countries with concentrated export baskets remain.
Unsymmetrical Aryl(2,4,6-trimethoxyphenyl)iodonium Salts: One-Pot Synthesis, Scope, Stability, and Synthetic Studies

Diaryliodonium salts have recently attracted significant attention as metal-free-arylation reagents in organic synthesis, and efficient access to these salts is critical for advancement of their use in reaction discovery and development. The trimethoxybenzene-derived auxiliary is a promising component of unsymmetrical variants, yet access remains limited. Here, a one-pot synthesis of aryl(2,4,6-trimethoxyphenyl)iodonium salts from aryl iodides, m-CPBA, p-toluenesulfonic acid, and trimethoxybenzene is described. Optimization of the reaction conditions for this one-pot synthesis was enabled by the method of multivariate analysis. The reaction is fast ( 85% average), and has broad substrate scope (>25 examples) including elaborate aryl iodides. The utility of these reagents is demonstrated in moderate to high yielding arylation reactions with C-, N-, O-, and S-nucleophiles including the synthesis of a liquid crystal molecule.
Cancer Clinical Trials Optimization and Pharmacogenomics

A critical overview of recent clinical trials in cancer is presented focused on signaling pathways blockers or inhibitors with a view to developing successful clinical trials employing personalized cancer therapies. Rational, pharmacogenomic strategies in cancer trials should be adopted that include specific molecular targeting based on adequate data for, and detailed modeling of, cancer cell genomes, modifications of cancer signaling pathways and epigenetic mechanisms. Novel translational oncogenomics research is rapidly expanding through the application of highly sensitive and specific advanced technology, research findings and computational tools and complex models to both pharmaceutical and clinical problems. Multiple sample analyses from several recent clinical studies have shown that gene expression data for cancer cells can be employed to distinguish between tumor types as well as to predict outcomes. Potentially important applications of such results are individualized human cancer therapies or, in general,'personalized medicine' that will have to be validated through optimally designed clinical trials in cancer. A Human Cancer Genomes and Epigenetics Project is proposed that can provide the essential data required for the optimal design of clinical trials with the goal of achieving significant improvements of the survival rates of cancer patients participating in clinical trials for advanced cancer stages. The results of such a six-year Human Cancer Genomes and Epigenetics Project should also greatly aid with the accelerated, rational development of effective anti-cancer medicines and the chemoprevention of cancers.
Strategies in synthesis of heparin/heparan sulfate oligosaccharides: 2000-present.

Abstract Heparin and heparan sulfate are members of the glycosaminoglycan family that are involved in a multitude of biological processes. The great interests in the anticoagulant properties of heparin have stimulated major advances in synthetic strategies toward clinically effective analogues, as demonstrated importantly by the approval of the fully synthetic pentasaccharide fragment, termed fondaparinux (Arixtra®), of the heparin macromolecule for treatment of deep-vein thrombosis. Given the highly complex nature of heparin and heparan sulfate, the chemical synthesis of their components is a challenging endeavor. In the past decade, multiple approaches have been developed to improve the overall synthetic efficiency. New strategies have emerged that can generate libraries of oligosaccharide components of heparin and heparan sulfate. This article discusses recent developments in the assembly of heparin and heparan sulfate oligosaccharides and the associated challenges in their synthesis.
Strain Test for Evaluation of Rubber Compounds

Abstract Measurements of elongation of rubber vulcanizates at a fixed stress have been made with a precision much greater than can be obtained in the usual measurements of stress at a specified elongation. Such measurements form the basis of a strain test developed to characterize rubber vulcanizates in control and research testing. Statistical analyses show that the errors introduced in the actual strain measurements are negligible compared to those introduced by variations during compounding and curing, whereas the errors introduced by the usual measurements of stress at a specified elongation are of the same order of magnitude as those for compounding and curing. The high precision of strain testing has been used to detect variations within a single sheet of vulcanized rubber and variations among sheets cured from the same compounded batch. It has been possible also to determine with a single sheet its change in stiffness or modulus with age. The uniform treatment of specimens in the strain test makes ...
Computing outside the box

The past decade has seen increasingly ambitious and successful methods for outsourcing computing. Approaches such as utility computing, on-demand computing, grid computing, software as a service, and cloud computing all seek to free computer applications from the limiting confines of a single computer. Software that thus runs "out-side the box" can be more powerful (think Google, TeraGrid), dynamic (think Animoto, caBIG), and collaborative (think FaceBook, myExperiment). It can also be cheaper, due to economies of scale in hardware and software. The combination of new functionality and new economics inspires new applications, reduces barriers to entry for application providers, and in general disrupts the computing ecosystem. I discuss the new applications that outside-the-box computing enables, in both business and science, and the hardware and software architectures that make these new applications possible.Ian leads computer science projects developing advanced distributed computing ("Grid") technologies, computational science efforts applying these tools to problems in areas ranging from the analysis of data from physics experiments to remote access to earthquake engineering facilities, and the Globus open source Grid software project.
Second-Law Heat Release Modeling of a Compression Ignition Engine Fueled With Blends of Palm Biodiesel

Modeling of engine-out heat release is of great importance for engine combustion research. Variations in fuel properties bring about changing combustion behavior within the cylinder, which may be captured by modeling of the rate of heat release. This is particularly true for biodiesel fuels, where changes in fuel behavior are linked to viscosity, density, and energy content. Heat release may also be expanded into an analysis using the 2nd Law of Thermodynamics, which may ascertain the pathways through which availability is either captured as useful work, unused as thermal availability of the exhaust gas, or wasted as heat transfer. In specific, the 2nd Law model identifies the period of peak availability, and thus the ideal period to extract work, and is of use for power optimization.A multi-zone (fuel, burned, and unburned) diagnostic model using a 1st Law of Thermodynamics analysis is utilized as a foundation for a 2nd Law analysis, allowing for a simultaneous energy and exergy analysis of engine combustion from a captured pressure trace. The model calibrates the rate and magnitude of combustion through an Arrhenius equation in place of a traditional Wiebe function, calibrated using exhaust emission measurements.The created model is then utilized to categorize combustion of diesel and palm biodiesel fuels, as well as their blends. The 2nd Law analysis is used to highlight the effects of increasing biodiesel usage on engine efficiency, particularly with respect to fuel viscosity and combustion temperature. The 2nd Law model used is found to provide a more clear understanding of combustion than the original 1st Law model, particularly with respect to the relationships between biodiesel content, viscosity, temperature, and diffusion-dominated combustion.Copyright © 2015 by ASME
Conic Optimization via Operator Splitting and Homogeneous Self-Dual Embedding

We introduce a first-order method for solving very large convex cone programs. The method uses an operator splitting method, the alternating directions method of multipliers, to solve the homogeneous self-dual embedding, an equivalent feasibility problem involving finding a nonzero point in the intersection of a subspace and a cone. This approach has several favorable properties. Compared to interior-point methods, first-order methods scale to very large problems, at the cost of requiring more time to reach very high accuracy. Compared to other first-order methods for cone programs, our approach finds both primal and dual solutions when available or a certificate of infeasibility or unboundedness otherwise, is parameter free, and the per-iteration cost of the method is the same as applying a splitting method to the primal or dual alone. We discuss efficient implementation of the method in detail, including direct and indirect methods for computing projection onto the subspace, scaling the original problem data, and stopping criteria. We describe an open-source implementation, which handles the usual (symmetric) nonnegative, second-order, and semidefinite cones as well as the (non-self-dual) exponential and power cones and their duals. We report numerical results that show speedups over interior-point cone solvers for large problems, and scaling to very large general cone programs.