cssi/SciSciGPT-SciSciNet huggingface dataset:
Flood Risks and Impacts: A Case Study of Thailand’s Floods in 2011 and Research Questions for Supply Chain Decision Making

Abstract This paper investigates the impact of floods on the global economy through supply chains, and proposes measures for the related supply chain risk. We examine Thailand’s 2011 flood since it is a notable example of the impact of floods both on industries and the whole economy. The protracted floods affected the primary industrial sectors in Thailand, i.e., the automotive and electronics industries, with a devastating impact on the whole economy. The impact of natural hazards on the global supply chain is increasing. However, the impact on each firm that is exposed is different depending on how well they are prepared and how they respond to the risks. Designing supply chains in a more resilient way will ultimately reduce risks to the economy. Comparing different supply chains and industries’ structure in Thailand, this study identifies the factors in private investment decision- making, such as locations of facilities, alternate locations of production, the diversified sources of procurement, emergent assistance from other partner companies in the same supply chain, and degree of the recovery of customers and proposes a hypothesis and related questions for future research.
Historical Developments in Hydroprocessing Bio-oils

This paper is a review of the developments in the field of catalytic hydroprocessing of biomass-derived liquefaction conversion products (bio-oil) over the past 25 years. Work has been underway, primarily in the U.S. and Europe, in catalytic hydrotreating and hydrocracking of bio-oil in both batch-fed and continuous-flow bench-scale reactor systems. A range of heterogeneous catalyst materials have been tested, including conventional sulfided catalysts developed for petroleum hydroprocessing and precious metal catalysts. The important processing differences have been identified, which required adjustments to conventional hydroprocessing as applied to petroleum feedstocks. This application of hydroprocessing is seen as an extension of petroleum processing and system requirements are not far outside the range of conventional hydroprocessing. The technology is still under development but can play a significant role in supplementing increasingly expensive petroleum.
Effects of a squeezed vacuum on a laser exhibiting phase locking: An application to a laser with injected atomic coherence

We study the steady-state operation and noise properties of a laser (ormaser) exhibiting phase locking when an ordinary vacuum is replaced by asqueezed vacuum. Such a phase-sensitive laser can be realized by preparing theactive medium initially in a coherent superposition of levels involved in thelaser transition. We develop a general formalism to treat number-phasefluctuations and quadrature fluctuations. When applied to a one-photon laserwith injected atomic coherence, we find that not only is a complete quenchingof the (spontaneous-emission) quantum noise possible, but the field canactually be in a squeezed state. The variance in either amplitude or phasequadrature can be below the vacuum noise level by a factor of 2 (50%) at theexpense of enhanced fluctuations in the other quadrature.
The Future of Presidential Libraries: Assessing Alternative Models from a Legal Research Perspective

Presidential libraries—each a unique combination of archival depository and historical museum—offer visitors an invaluable opportunity to examine millions of papers, records, and artifacts from the administrations of our chief executives. In response to a congressional directive to consider means of reducing costs and improving the preservation of and access to presidential records, the National Archives and Records Administration has proposed five alternatives to the current presidential library system. This article analyzes these alternative models from the perspective of the legal research community. After discussing the role of presidential libraries in legal research, this article considers the merits of each model and concludes that a central archival depository would best meet the information needs of legal researchers.
Reduced dopamine terminal function and insensitivity to cocaine following cocaine binge self-administration and deprivation

Despite large numbers of studies describing neuroadaptations caused by chronic cocaine exposure, there remains considerable uncertainty as to whether alterations in dopamine (DA) neurotransmission are responsible for progression into an addicted state. High-intake, 24-h access cocaine self-administration (SA, 10 days) followed by an extended (7 days), but not 1 day deprivation period produces an increased motivation to SA cocaine as measured by a progressive ratio protocol. Following binge cocaine SA and deprivation, the status of DA terminals in the nucleus accumbens (NAc) was investigated using microdialysis in freely moving rats and voltammetry in brain slices. At 1 and 7 days following binge cocaine SA, baseline extracellular DA concentrations in the NAc core were decreased by 40 and 55% of control levels, in the 1 and 7 day deprivation groups, respectively. Acute cocaine (1.5 mg/kg, i.v.) administration increased extracellular DA (350%) in the NAc core of naive animals but failed to significantly increase DA at 1 or 7 days following binge cocaine SA. The shell of the NAc showed a similar lack of effect of cocaine. Analysis of DA terminals in brain slices showed that cocaine was markedly less effective in inhibiting DA uptake at 1 and 7 days of cocaine deprivation (max effect 40% of control). Electrically stimulated DA release was decreased at 1 day and further decreased at 7 days of deprivation (67 and 49% of control, respectively). The rate of DA uptake was increased (150% of control) following binge SA, irrespective of deprivation period. Finally, presynaptic autoreceptors were subsensitive at both time points, as measured by the ability of quinpirole, a D2-like DA receptor agonist, to inhibit DA release. Thus, the NAc was hypodopaminergic and DA terminals were less sensitive to cocaine following binge cocaine SA and deprivation.
Comparing parameter schemes for propositional reasoning: an empirical study

Complete propositional reasoning is impractical as a tool in artificial intelligence, because it is computationally intractable. Most current approaches to limited propositional reasoning cannot easily be adjusted to use more (or less) time to prove more (fewer) theorems when the task requires it. This difficulty can be solved byparameterizing the reasoner: designing in a ‘power dial’ giving the user fine control over cost and performance. System designers face the significant problem of choosing the best parameter scheme to use. This paper proposes an empirical methodology for comparing parameter schemes and illustrates its use in comparing eight such schemes for a given complete, resolution-based propositional reasoner. From the data, a clear choice emerges as the most preferable of the eight.
A model-based technique for efficient evaluation of noise robustness

In this paper, we present an analytical technique for deriving noise rejection curves (NRCs) and the associated noise susceptibility metric under parameter variations (Leff, VT, VDD and channel width, W). The method involves modeling of the pull-up and pull-down resistances using approximated BSIM4 device equations. Compared to circuit simulation results, the analytical model provides more than live orders of magnitude speedup while maintaining an average (maximum) error of 1.3% (5%) over the entire range of parameter variations, which makes it suitable for design optimization for noise robustness.
Sex-Specific Time Trends in Very Elderly Patients (Aged ≥80 Years) Hospitalized with Myocardial Infarction

Objective: To assess sex-related time trends in the proportion of very elderly patients (age ≧80) hospitalized with myocardial infarction (MI). Subjects and Methods: Data were obtained from all states in the USA that contributed to the Nationwide Inpatient Sample. All patients admitted to hospital between 1997 and 2006 with a primary discharge diagnosis of MI, identified by the International Classification of Diseases, Ninth Revision procedure codes were included. Percentages of MI hospitalizations comprising men and women aged ≧80 were evaluated. Results: Overall, between 1997 and 2006, the absolute number of MI hospitalizations decreased from 732,170 to 674,988, but the percentage of very elderly men rose in a roughly linear pattern by 2.84% from 14.2% in 1997 to 17.1% in 2006 (95% CI 1.9–3.8%, p Conclusions: Over the last decade, the percentage of very elderly women hospitalized with MI in the United States rose at almost twice the rate of similarly aged men. These trends may be expected to exponentially worsen given the aging global population.
WAVES ON A METAL SURFACE AND QUANTUM CORRALS

Electrons occupying surface states on the close-packed faces of noble metals form a two-dimensional (2-d) nearly free electron gas. Because this system is accessible to the scanning tunneling microscope (STM), it provides a unique opportunity to study the local properties of low-dimensional electrons. On Cu(111) we have observed standing wave patterns in the surface local density of states due to the quantum mechanical interference of surface state electrons scattering off of step edges and adsorbates. We find that Fe adatoms strongly scatter the surface state and, as a result, are good building blocks for constructing atomic-scale barriers (“quantum corrals”) to confine the surface state electrons. The barriers are constructed by individually positioning Fe adatoms using the tip of a cold (4 K) STM. Tunneling spectroscopy performed inside of the corrals reveals discrete resonances, consistent with size quantization. A more quantitative understanding is obtained by accounting for the multiple scattering of surface state electrons with the corrals’ constituent adatoms. This scattering is characterized by a complex phase shift which can be extracted from the electronic density pattern inside a quantum corral.
Earnings smoothing around open-market share repurchases

Purpose – The purpose of this paper is to examine whether firms engage in earnings decreasing management before share repurchases to mislead investors or to smooth earnings and improve earnings informativeness. Design/methodology/approach – The authors examine discretionary accruals and cash flows around open-market share repurchases. The primary discretionary accruals measure is industry- and performance-adjusted discretionary current accruals estimated from cash-flow data. Findings – Results show that, firms experience temporary increases in operating cash flows and use negative discretionary accruals to smooth earnings before share repurchases. Firms with the highest pre-repurchase cash flows use the lowest pre-repurchase discretionary accruals. Moreover, pre-repurchase discretionary accruals reflect expectations about future operating cash flows. Firms with the strongest deterioration in operating cash flows after repurchases use the lowest pre-repurchase discretionary accruals. These findings suggest...
Hematological abnormalities in severe anorexia nervosa.

Little is known about the prevalence of hematologic abnormalities in adults with severe anorexia nervosa. We report the first major analysis of hematologic dysfunction in such patients. We retrospectively analyzed the charts of 53 men and women with severe anorexia nervosa, admitted between October 2008 and December 2010 for medical stabilization to our center, which has a national referral base. Patients were predominantly female (89 %), with a median age of 28 years (range 17-65), and were hospitalized for a median duration of 15 days (I.Q.R. 9-29). Nadir body mass index during hospitalization was markedly low at 12.4 kg/m(2) (range 8.4-15.7), and the mean discharge BMI was 13.8 kg/m(2) (range 10.2-16.8). 83 % of patients were anemic (hematocrit 400 k/μL) during their hospitalization. Eighty-nine percent of patients had resolved their neutropenia by discharge. Marked hematologic deficiencies are often present in patients with severe anorexia nervosa, generally attributed to starvation-mediated gelatinous marrow transformation which resolves with proper nutritional rehabilitation. Improved provider awareness of this association may reduce unnecessary testing and costly treatment interventions.
A Limiting Absorption Principle for Schrödinger Operators with Generalized Von Neumann–Wigner Potentials II. The Proof

In this series of papers we prove the limiting absorption principle over a given interval for a class of Hamiltonians which contains the original one of von Neumann and Wigner. More specifically, the Hamiltonians are of the form −Δ + c sin b|x|/|x|β + V(x), where 2/3 < β ≤ 1,V(x) is a short range potential and I is a given compact subinterval of the open positive axis which does not contain the pointb2/4.
Controlling structure distortions in 3-layer ferroelectric Aurivillius oxides

Abstract Combined Rietveld refinements of x-ray and neutron powder diffraction data were used to understand the subtle structure distortions in 3-layer Aurivillius oxides that yield off-centering displacements in ferroelectric and multiferroic compositions. Ferroelectric phases including Bi2A2Ti3O12 (A=La, Pr, Nd, La/Pr, La/Nd, Pr/Nd), Bi2A2TiNb2O12 (A=Ca/Sr, Sr, and Sr/Ba) and Bi2A2TiTa2O12 (A=Ca/Sr, and Sr/Ba) were studied to separate the effects of cation size and charge on the structure distortions and properties. A new approach to describing the local coordination around the Ti, Nb, and/or Ta ions is presented, where the oxygen octahedra are characterized as containing kinks in three dimensions. The kink angles follow trends with the A-site ionic radius and the ferroelectric polarization. The driving force for extensive cation site mixing between the Bi and A-site cations has been clearly established, with site mixing required to maintain interlayer bonding.
How to stop interconnects from hindering the future of computing

Unprecedented transistor integration capacity will be available to make computing truly ubiquitous, but the energy consumption will be a major challenge. Compute energy can be reduced by employing near threshold voltage operation. However, data movement energy will become prohibitive. Severe tapering of interconnect bandwidth brings power consumption within limit, but potentially hindering the system performance.
Ilio-psoas abscess: diagnosis and management

The triad of fever, limp, and pain in the flank, pelvis or leg often leads to the evaluation of the hip, genitourinary or gastrointestinal system. In the past 6 years, at our hospital, five adolescents and one young adult with these symptoms have had an ilio-psoas abscess, all diagnosed by ultrasonography. Once the diagnosis was established, four patients were treated successfully by percutaneous retroperitoneal drainage guided by ultrasonography [3] or computed tomography [1]. Catheter drainage averaged 11 days accompanied by appropriate antibiotics. The remaining two patients had surgical transperitoneal drainage. Growth ofStaphylococcus aureus, from an ilio-psoas abscess indicates that the process is primary in origin. Growth of fecal flora suggests an intra-abdominal process and warrants further investigation. Ilio-psoas abscess can be readily diagnosed by ultrasonography or computed tomography and treated by percutaneous retroperitoneal drainage.
Acoustic Emission and Microcracking in Sapphire, Sintered Al2O3, Al/Al2O3 Composite, and Aluminum

A range of materials with brittle to ductile behavior (single-crystal and polycrystalline alumina, aluminum/alumina composite, and metallic aluminum) were investigated by acoustic emission (AE) methods for microcracking during hardness indentations or cooling from elevated temperatures (800°C). During indentation, the extent of crack formation (and the AE counts) decreased in the following order: sapphire, sintered alumina, aluminum/alumina composite with no microcracking in metallic aluminum. During cooling from 800°C, polycrystalline alumina exhibited more extensive microcracking than the aluminum/alumina composite, suggesting that the metallic phase in the aluminum/alumina composite absorbs stresses more than the glassy boundary phase in sintered alumina.
Optimal feedback stabilization policy with asymmetric loss functions

Abstract The major emphasis in this paper is to utilize system-theoretic concepts to adapt econometric models via state-space models to solve for optimal stabilization policies involving asymmetric loss functions. Computational feasibility and ease of implementation are regarded as matters of great importance and hence the dimensionality of the problem is given due attention. It is well established that the optimal control for such a problem is in the form of linear state feedback, which provides us with a more natural solution form. An implementable algorithm for this purpose is presented. We also investigate the importance of the time horizon over which optimization is carried out. The analysis is carried out for the deterministic model of the economy, but we discuss situations where uncertainty enters into the model in additive form. We freely borrow ideas from the vast control literature, specifically, from the area of optimal control for linear systems with quadratic cost functions.
Composition factors affecting the water vapor permeability and tensile properties of hydrophilic zein films

Transparent unplasticized zein films were prepared in aqueous ethanol or acetone. Tensile properties indicated that films prepared in acetone were stronger but less flexible than those prepared in ethanol. Both types of films, however, were too brittle for most applications. Films containing a glycerol:poly(propylene glycol) ratio of 1:3 exhibited elongation values almost fifty times greater than glycerol-plasticized films. Incorporation of cross-linking agents into zein films resulted in approximately a 2−3-fold increase in tensile strength values. Water vapor barrier properties were best for unplasticized zein films cross-linked with 20% polymeric dialdehyde starch. Incorporation of plasticizer into zein films resulted in an almost doubling in water vapor permeability values. Keywords: Hydrophilic; film; zein; tensile properties; plasticizer; cross-linking agents; water vapor permeability
A transient interaction between two phosphorelay proteins trapped in a crystal lattice reveals the mechanism of molecular recognition and phosphotransfer in signal transduction.

Abstract Background: Spo0F and Spo0B specifically exchange a phosphoryl group in a central step of the phosphorelay signal transduction system that controls sporulation in Bacilli. Spo0F belongs to the superfamily of response regulator proteins and is one of 34 such proteins in Bacillus subtilis. Spo0B is structurally similar to the phosphohistidine domain of histidine kinases, such as EnvZ, and exchanges a phosphoryl group between His30 and Asp54 on Spo0F. Information at the molecular level on the interaction between response regulators and phosphohistidine domains is necessary to develop a rationale for how phospho-signaling fidelity is maintained in two-component systems. Results: Structural analysis of a co-crystal of the Spo0F response regulator interacting with the Spo0B phosphotransferase of the phosphorelay signal transduction system of B. subtilis was carried out using X-ray crystallographic techniques. The association of the two molecules brings the catalytic residues from both proteins into precise alignment for phosphoryltransfer. Upon complex formation, the Spo0B conformation remains unchanged. Spo0F also retains the overall conformation; however, two loops around the active site show significant deviations. Conclusions: The Spo0F–Spo0B interaction appears to be a prototype for response regulator–histidine kinase interactions. The primary contact surface between these two proteins is formed by hydrophobic regions in both proteins. The Spo0F residues making up the hydrophobic patch are very similar in all response regulators suggesting that the binding is initiated through the same residues in all interacting response regulator–kinase pairs. The bulk of the interactions outside this patch are through nonconserved residues. Recognition specificity is proposed to arise from interactions of the nonconserved residues, especially the hypervariable residues of the β4–α4 loop.
Elucidation of the rapid in vivo metabolism of arecoline.

Abstract 1. 1. The metabolism of arecoline (ARE) was examined in homogenates of mouse blood, brain, kidney, and liver tissue. 2. 2. Liver and kidney tissues exhibited the greatest rates of ARE metabolism. 3. 3. The specific carboxylesterase inhibitor TOCP (tri- o -tolyl-phosphate) as well as ISO-OMPA (tetraisopropyl-pyrophosphoramide) completely blocked ARE metabolism in liver homogenate. 4. 4. ISO-OMPA significantly inhibited ARE metabolism by purified porcine liver carboxylesterase. 5. 5. The data suggest that carboxylesterase (EC 3.1.1.1) is primarily responsible for the metabolism of ARE in the mouse.
We're no metrosexuals: identity, place and sexuality in the struggle over gay marriage

In 2000 the state of Nebraska adopted the most limited-to-date restrictions on gay marriages, civil unions and domestic partnership. The campaign drew heavily on a sense of local identity rooted in a constructed definition of Nebraska that excluded sexual difference. Campaigners also capitalized on the self-identification of gays and lesbians with cosmopolitan urban areas, seen as foreign and antithetical to local identity. Examining the ways that anti-gay forces engage in identity politics provides a different way of looking at the politics of gay marriage that reveals the centrality of place in stabilizing identity categories and is a useful reconceptualization of identity issues for queer theorists and activists. Nous ne sommes pas des metrosexuels: l'identite, le lieu et la sexualite dans la lutte en faveur du mariage gai En 2000, l'etat du Nebraska a adopte les restrictions des moins liberales jusqu'a present sur les mariages gai, les unions civiles et le partenaire domestique. La campagne se fondait...
Experiments for Online Estimation of Heavy Vehicle’s Mass and Time-Varying Road Grade

In this paper application of recursive least squares with multiple forgetting factors is explained for online estimation of Heavy Duty Vehicle mass and road grade. The test data is obtained from highway experiments with a Freightliner truck. The experimental setup is explained in detail. This data is used to validate the longitudinal dynamics model of the truck. Then two distinct driving cycles are used to investigate the performance of the mass and grade estimation scheme. In he first scheme no gear shift occurs and the only concern is persistence of excitations. It is shown that if the excitations are persistent, mass and time-varying grade are estimated with good accuracy. In the second cycle gearshifts occur and the challenge is the unmodelled dynamics during gearshifts which cause large overshoots in the estimates. A method is proposed to circumvent this problem and good estimation results are shown with this provision.Copyright © 2003 by ASME
Paleoecology of Santa Barbara Zone, Pliocene of Southern California: ABSTRACT

The Santa Barbara fauna is used to define a widespread zone in the Plio-Pleistocene rocks of the Ventura basin. This fauna is characterized by extinct, northern extra-limited, and submergent species of Mollusca. The characteristic species are accompanied by some locally extant species. A section of the Fernando Formation exposed in Balcom Canyon in the central Ventura basin is composed of rocks deposited in water depths greater than 100 fathoms. Turbidite sandstones contain fossil Mollusca derived from all depth zones, from the depth of deposition on up to the intertidal. These mixed faunas were separated into depth associations on the basis of the depth ranges of living members of the faunas and on apparent associations in the faunas. The characteristic End_Page 474------------------------------ species of the Santa Barbara fauna are generally part of an association that lived in the deep-inner to shallow-outer sub-littoral depth zones (15-50 fathoms). The lower part of the section studied contains fossils from the same depth zone as the Santa Barbara fauna. These fossils indicate that water temperatures were not detectably different than at present. The upper part of the section contains the Santa Barbara fauna, which indicates that waters at these depths were considerably colder in this region than at present. Most of the characteristic extra-limited species do not range south of Puget Sound. Associated with the characteristic species are others that do not live that far north today. This association of species not now living together must indicate either that the temperature tolerances of some have changed or that their distributions are controlled by some factor other than mean annual temperature. The upper part of the section also contains numerous mollusks that lived in shallower water. The present distributions of extant members of these faunas indicate water temperatures not detectably different from temperatures today. End_of_Article - Last_Page 475------------
Mixed metal cluster complexes containing the bis-ferrocenylbutadiyne ligand: their structures and electrochemical responses

Abstract Two new platinum-triosmium cluster complexes PtOs3(CO)9(COD)(μ4-FcC4Fc) (4) and Pt2Os3(CO)10(COD)(μ5-FcC4Fc) (5) containing the electroactive 1,4-bis-ferrocenylbutadiyne ligand FcC4Fc were obtained from the reaction of Os3(CO)10(μ3-FcC4Fc) (3) with Pt(COD)2. Compounds 4 and 5 were characterized by IR and 1H-NMR spectroscopy, by single crystal X-ray diffraction analysis and by differential pulse voltammetry. Compound 4 consists of a butterfly cluster of one platinum and three osmium atoms with the platinum atom in one of the wing-tip positions. The cluster is co-ordinated to one of the CC triple bonds of the FcC4Fc ligand in the μ4-bonding mode. Cluster 5 exhibits the bow tie structure for five metal atoms: two of platinum and three of osmium. Both triple bonds of the butadiyne ligand are co-ordinated in this complex. Both products show two one electron oxidations for the ferrocenyl groups: for 4 at E°=+0.356 and +0.503 V versus Ag ∣ AgCl, and for 5 at E°=+0.478 and +0.576 V.
Pathways of influence on fifth and eighth graders' reports about having had sexual intercourse.

The purposes of this study were to explore the differences between fifth and eighth graders' self-reports of having initiated sexual intercourse and the factors related to their early sexual debuts. The urban sample consisted of African American and white fifth (n = 59) and eighth (n = 169) graders. Among fifth graders 46% and among eighth graders 55% reported they had initiated sexual intercourse. Sexual intercourse was more common than other risk behaviors such as cigarette smoking and drinking. The multivariate analyses indicated that the influences on the early initiation of sexual intercourse were complex. Specifically, gender, use of alcohol, costs (i.e., perceptions of negative consequences), and personal norms (i.e., beliefs about when to initiate sexual intercourse) had no direct influence on having initiated sexual intercourse, but indirectly affected the initiation of sexual intercourse through the frequency of other intimate behaviors. The findings are discussed in terms of gender-specific socialization into sex roles and the need to design risk reduction interventions that incorporate messages from multiple social sources.
Mortality associated with feeding catheter jejunostomy after radical cystectomy

Twenty-five patients undergoing cystectomy and diversion for transitional cell carcinoma of the bladder and 8 patients having major surgery for renal and testes neoplasms and trauma have received needle jejunostomy placement at the time of surgery. One patient died secondary to vascular collapse. Postmortem examination revealed necrosis of the entire small bowel except the conduit segment. The implications of these findings are discussed.
A Portable Ge(Li) Detector for Field Measurement of Radionuclides in the Environment

A description of a portable Ge(Li) field spectrometer and its application to in situ measurements is given. The mathematical techniques of calibrating the spectrometer so that field spectrometer counting rates may be converted into units of soil activity are developed. The quantification of gamma-ray emitting radionuclides in the field has proven to be more sensitive than laboratory analysis using Ge(Li) anticoincidence shielded spectrometers. This was demonstrated by obtaining approximately the equivalent statistical accuracies for quantifying several radionuclides from a 30 min field count as compared to a 1437 min laboratory analysis. A comparison between the results obtained from field analysis with those obtained by returning the samples to the laboratory are given for natural radionuclides and 137Cs. An example of qualitative spectral data obtained from field measurements of gaseous emissions from a BWR reactor is also given.
Double-Loop Learning in Higher Education

(2007). Double-Loop Learning in Higher Education. Change: The Magazine of Higher Learning: Vol. 39, No. 4, pp. 36-41.
Ice gouge recurrence and rates of sediment reworking, Beaufort Sea, Alaska

Certain shelf areas have been resurveyed with side-scanning sonar, fathometer, and accurate navigational control for studies of the rate of ice gouging and sediment reworking by ice in the Beaufort Sea, Alaska. Analysis of one such survey, initially done in 1973 and rerun in 1975 along 14 km of track-line in 6 to 14 m of water depth, suggests complete reworking of the bottom to an average depth of 20 cm in 50 yr. Only 3 cm of sediment accumulated during this time interval, making the rate of reworking much higher than rate of deposition.
Mass transfer mechanism in liquid chromatography columns packed with shell particles: would there be an optimum shell structure?

Abstract The mass transfer mechanisms in columns packed with old (55 μm Zipax and 5 μm Poroshell) and recently commercialized shell particles (2.7 μm Halo-C18 and Kinetex-C18) were investigated from a physico-chemical point of view. Combining a model of diffusion in heterogeneous packed beds (effective medium theory) with values of the heights equivalent to a theoretical plate (HETPs derived from the first and second central moments of the elution profiles) and of the peak variances provided by the peak parking method, we demonstrate that columns packed with current shell particles perform better than those packed with fully porous particles in resolving low molecular weight compounds because the eddy diffusion term of the van Deemter equation of the former is markedly smaller. The calculation of eddy diffusion in column beds suggests that the smaller A terms are due to smaller trans-column velocity bias in columns packed with shell particles. We also show that the mass transfer of large molecules (e.g., proteins) is faster when the internal volume accessible to the analyte increases. Therefore, it is suggested that shell particles made of concentric layers with average pore sizes increasing with increasing diameter would provide columns with higher efficiency.
Revising explanatory models to accommodate anomalous genetic phenomena: Problem solving in the “context of discovery”

Past problem–solving research has provided a basis for helping students structure their knowledge and apply appropriate problem–solving strategies to solve problems for which their knowledge (or mental models) of scientific phenomena is adequate (model–using problem solving). This research examines how problem solving in the domain of Mendelian genetics proceeds in situations where solvers' mental models are insufficient to solve problems at hand (model–revising problem solving). Such situations require solvers to use existing models to recognize anomalous data and to revise those models to accommodate the data. The study was conducted in the context of 9–week high school genetics course and addressed: the heuristics charactenstic of successful model–revising problem solving: the nature of the model revisions, made by students as well as the nature of model development across problem types; and the basis upon which solvers decide that a revised model is sufficient (that t has both predictive and explanatory power). © 1995 John Wiley & Sons, Inc.
Primary structure and functional expression of a rat G-protein-coupled muscarinic potassium channel

Parasympathetic nerve stimulation causes slowing of the heart rate by activation of muscarinic receptors and the subsequent opening of muscarinic K+ channels in the sinoatrial node and atrium. This inwardly rectifying K+ channel is coupled directly with G protein. Based on sequence homology with cloned inwardly rectifying K+ channels, ROMK1 (ref. 11) and IRK1 (ref. 12), we have isolated a complementary DNA for a G-protein-coupled inwardly rectifying K+ channel (GIRK1) from rat heart. The GIRK1 channel probably corresponds to the muscarinic K+ channel because (1) its functional properties resemble those of the atrial muscarinic K+ channel and (2) its messenger RNA is much more abundant in the atrium than in the ventricle. In addition, GIRK1 mRNA is expressed not only in the heart but also in the brain.
Drop breakup in a turbulent flow. I: Conceptual and modeling considerations

Abstract This basic conceptual study of dilute second-phase drop breakup in turbulent mixing vessels includes examination of (1) local viscous effects in the breakup of droplets smaller than the Kolmogoroff microscale, and (2) inertial effects in the breakup of droplets larger than the Kolmogoroff microscale. Particular emphasis is placed on the evaluation of local and spatial variability in the disruptive forces, and the local time and space scales of interest. For the second mechanism, a two-dimensional linear drop oscillation model is developed. Simulations using the model suggest that the critical Weber number may be a function of drop size, interfacial tension, viscosity, and the magnitude and duration of the disruptive force.
Asymmetric cell division via DNA strand-specific epigenetic imprinting and segregation explains eukaryotic development

The asymmetric cell division is crucial during development and to produce self-renewing stem cells. A large body of work on Drosophila and C. elegans suggests that this process occurs by non-equivalent distribution of proteins and/or mRNA (intrinsic factors) to daughter cells, or by their differential exposure to cell extrinsic factors. In contrast, strictly based on template “Watson” versus “Crick” strand inherited from the parental cell, haploid fission yeast sister cells developmentally differ by inheriting sister chromatids that are differentiated by epigenetic means. Specifically, the double helical structure of DNA is the ultimate determinant of asymmetric cell division. To employ this kind of mechanism for cellular differentiation in diploid organisms, selective segregation must occur for partitioning epigenetically differentiated sister chromatids from both chomosome homologs to specific daughter cells, at a specific cell division, during multicelluar organism development. We previously proposed that Somatic Sister chromatid Imprinting and Selective chromatid Segregation (SSIS) model might explain development in eukaryotes, such as that of the body left-right axis laterality specification in mice and brain laterality in humans. However, for technical reasons, it is impossible to determine whether such a mechanism operates during embryonic development in higher organisms. Recently we discovered the second example of DNA strand-specific imprinting mechanism in Schizosaccharomyces japonicus yeast (36% GC content), whose DNA sequence is only about 30% similar compared to the well-studied S. pombe (44% GC). Therefore these highly diverged yeasts provide the first two examples in which the intrinsic chirality of double helical structure of DNA forms the primary determinant of asymmetric cell division [1]. I will also discuss support for our model to explain body laterality development in mice [2]. Interestingly, another study also suggested that C. elegans neuronal asymmetry develops via the SSIS model [3].
Grassland compositional change in relation to the identity of the dominant matrix-forming species

Background: Grasslands have only a few dominants and most of the diversity consists of subdominants. Because dominants differ widely in phenology and resource use, dominants may control the recruitment and establishment of other species. Aims: To explore the relationship between the identity of the dominant species and successional vegetation changes in grassland communities. Methods: The compositional change over 23 years in 1900 permanent plots dominated by four grasses (Andropogon gerardii, Elymus repens, Poa pratensis and Schizachyrium scoparium) was examined within 19 old fields in Minnesota. Fields were abandoned 1–56 years before sampling. Rate of directional change and degree of compositional dissimilarity were determined. Results: Non-natives, P. pratensis and E. repens, were associated with either no or a slow directional change. Elymus repens was associated with high dissimilarity and P. pratensis with intermediate dissimilarity. Natives, A. gerardii and S. scoparium, were associated with compo...
The power of light in polymer science: photochemical processes to manipulate polymer formation, structure, and properties

As the demand for polymeric materials transitions towards the need for customizable, high value, specialty polymeric materials, the ability to use light to initiate various physicochemical changes in polymers represents one of the most powerful and rapidly evolving approaches. Whether for polymer formation, polymer modification, shape change, or inducing smart material responses, light has the unique capacity for enabling 4D manipulation of each of those processes. Given the simple, 3D ability to focus light on a targeted voxel and the even simpler ability to turn a light on and off to facilitate temporal control, light has been used widely in various polymer modifications. Further, in addition to the ability to enhance the control of various reactive processes, due to the much greater energy available in a photon as compared to the thermal energy available, light enables chemical processes to occur at ambient conditions that are otherwise inaccessible without heating. In particular, within the polymer chemistry field, light has been used to cause bond formation, bond degradation, and isomerization, with subsequent reactions including polymerization, polymer degradation, polymer functionalization, and responsive changes in properties of smart materials. Here, this article attempts to provide a fundamental basis for the various photochemical processes implemented in polymer systems, followed by selected examples of that implementation in various polymerization, functionalization, degradation, and other reactions.
P3-134: Assessment of Japanese- and English-language equivalence of the cognitive abilities screening instrument (CASI) among Japanese-Americans in two large epidemiological studies

memory, the Neuropsychological Assessment Battery (NAB) List Learning (LL) test (Stern & White, 2003) is a promising tool for the assessment of older adults due to its relative simplicity, excellent psychometric validation, equivalent forms, and extensive normative data in older individuals. This study examined the diagnostic utility of the NAB LL test in differentiating cognitively normal, MCI, and AD participants. Methods: Extant data from the Boston University Alzheimer’s Disease Center Registry was retrospectively analyzed for 153 participants (57-94 years, 74 8 years; 61% women) diagnosed by a consensus team as cognitively normal (n 98), amnestic MCI (single or multiple domain; n 29), or AD (n 26). Diagnoses were made independent of NAB LL performance. To determine classification accuracy, receiver operating characteristics analyses were conducted for seven NAB LL variables (List A Immediate Recall, List B Immediate Recall, Short Delay Recall, Long Delay Recall, Percent Retention, and Recognition Hits and False Alarms). In addition, ordinal multiple regression was used to create a model to predict group membership based on a combination of the NAB LL variables. Results: The sensitivities and specificities of the NAB LL test variables were good to excellent, yielding positive likelihood ratios ranging from 1.8 to 30.2 (Mdn 4.2). The ordinal regression produced a model that predicted group membership with an overall accuracy of 85%. The model was most accurate at classifying controls (97%), followed by AD (74%) and MCI (52%), which indicates that it can very accurately rule out the latter two diagnoses. Conclusions: Both the regression-based model and the individual NAB LL variables were highly accurate in differentiating cognitively normal controls, MCI, and AD groups. Compared to published data, the classification accuracy statistics presented here appear to match or exceed those reported for other common list learning tests (e.g., HVLT-R, CERAD, CVLT) in this population.
The origin of circular dichroism in unsubstituted carbohydrate polymers

Molecular modeling calculations support assignment of the circular dichroism (CD) of unsubstituted saccharides and polysaccharides to oxygen-centered transitions of the acetal chromophore. The results are in agreement with an empirical CD-based assignment, which treated the acetal chromophore as two weakly coupled ether chromophores.
Comparison of three prehospital cervical spine protocols for missed injuries.

Introduction: We wanted to compare 3 existing emergency medical services (EMS) immobilization protocols: the Prehospital Trauma Life Support (PHTLS, mechanism-based); the Domeier protocol (parallels the National Emergency X-Radiography Utilization Study [NEXUS] criteria); and the Hankins’ criteria (immobilization for patients 65 years, those with altered consciousness, focal neurologic deficit, distracting injury, or midline or paraspinal tenderness).To determine the proportion of patients who would require cervical immobilization per protocol and the number of missed cervical spine injuries, had each protocol been followed with 100% compliance. Methods: This was a cross-sectional study of patients ≥18 years transported by EMS post-traumatic mechanism to an inner city emergency department. Demographic and clinical/historical data obtained by physicians were recorded prior to radiologic imaging. Medical record review ascertained cervical spine injuries. Both physicians and EMS were blinded to the objective of the study. Results: Of 498 participants, 58% were male and mean age was 48 years. The following participants would have required cervical spine immobilization based on the respective protocol: PHTLS, 95.4% (95% CI: 93.1-96.9%); Domeier, 68.7% (95% CI: 64.5-72.6%); Hankins, 81.5% (95% CI: 77.9-84.7%). There were 18 cervical spine injuries: 12 vertebral fractures, 2 subluxations/dislocations and 4 spinal cord injuries. Compliance with each of the 3 protocols would have led to appropriate cervical spine immobilization of all injured patients. In practice, 2 injuries were missed when the PHTLS criteria were mis-applied. Conclusion: Although physician-determined presence of cervical spine immobilization criteria cannot be generalized to the findings obtained by EMS personnel, our findings suggest that the mechanism-based PHTLS criteria may result in unnecessary cervical spine immobilization without apparent benefit to injured patients. PHTLS criteria may also be more difficult to implement due to the subjective interpretation of the severity of the mechanism, leading to non-compliance and missed injury. [West J Emerg Med. 2014;15(4):471-479.]
Teachers, Texts, and Scribes

Books reviewed in this article: Snyder, H. Gregory, Teachers and Texts in the Ancient World: Philosophers, Jews Christians Haines-Eitzen, Kim, Guardians of Letters: Literacy, Power, and the Transmitters of Early Christian Literature
Graphs-at-a-time: query language and access methods for graph databases

With the prevalence of graph data in a variety of domains, there is an increasing need for a language to query and manipulate graphs with heterogeneous attributes and structures. We propose a query language for graph databases that supports arbitrary attributes on nodes, edges, and graphs. In this language, graphs are the basic unit of information and each query manipulates one or more collections of graphs. To allow for flexible compositions of graph structures, we extend the notion of formal languages from strings to the graph domain. We present a graph algebra extended from the relational algebra in which the selection operator is generalized to graph pattern matching and a composition operator is introduced for rewriting matched graphs. Then, we investigate access methods of the selection operator. Pattern matching over large graphs is challenging due to the NP-completeness of subgraph isomorphism. We address this by a combination of techniques: use of neighborhood subgraphs and profiles, joint reduction of the search space, and optimization of the search order. Experimental results on real and synthetic large graphs demonstrate that our graph specific optimizations outperform an SQL-based implementation by orders of magnitude.
Improved response in high-risk neuroblastoma with protracted topotecan administration using a pharmacokinetically guided dosing approach.

Purpose To estimate the response rate and toxicity associated with intravenous topotecan when it is administered on a protracted schedule according to a pharmacokinetically guided dosing approach to treat childhood high-risk neuroblastoma. Patients and Methods In this prospective phase II trial, topotecan was administered intravenously daily for 5 days for each of 2 consecutive weeks for two cycles. On the basis of topotecan systemic clearance, doses were individualized to attain a single-day topotecan lactone area under the plasma concentration-time curve (AUC) of 80 to 120 ng/mL · h. Patients subsequently received standard treatment. Results Both cycles were administered to 28 (93%) of the 30 enrolled patients (median age, 3.1 years). Target topotecan AUCs were achieved in 92 (72%) of the 127 measurements conducted after pharmacokinetically guided adjustment; the median dosage required to achieve target AUCs was 2.7 mg/m2 (range, 0.95 to 3.8 mg/m2). The response rate was 60% (95% CI, 41% to 77%); there ...
A real-time ultrasound time-domain correlation blood flowmeter. I. Theory and design

A real-time ultrasound time-domain correlation (UTDC) blood flowmeter has been developed. Real-time performance has been achieved through the implementation of a custom-designed high-speed residue-number system (RNS) hardware correlator. The flowmeter is interfaced to a commercial ultrasound imager and can produce one-dimensional velocity versus range graphs at a rate of three per second. It has been validated in a blood flow phantom under a variety of conditions along with in vivo measurements in the human carotid artery. The theory of the time-domain correlation technique, design and implementation of flowmeter hardware, and the important correlation parameters which affect the performance of the flowmeter are described. >