cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantum phase transitions in models of coupled magnetic impurities

We discuss models of interacting magnetic impurities coupled to a metallic host, which show one or more boundary quantum phase transitions where the ground-state spin changes as a function of the interimpurity couplings. The simplest example is realized by two spin-$\frac{1}{2}$ Kondo impurities coupled to a single orbital of the host. We investigate the phase diagram and crossover behavior of this model and present numerical renormalization-group results together with general arguments showing that the singlet-doublet quantum phase transition is either of first order or of the Kosterlitz-Thouless type, depending on the symmetry of the Kondo couplings. Thus we find an exponentially small energy scale within the Kondo regime, and a two-stage Kondo effect, in a single-channel situation. Connections to other models and possible applications are discussed.
Efficient algorithms for solving tensor product finite element equations

There are currently several highly efficient methods for solving linear systems associated with finite difference approximations of Poisson's equation in rectangular regions. These techniques are employed to develop both direct and iterative methods for solving the linear systems arising from the use ofC 0 quadratic orC 1 cubic tensor product finite elements.
A New Synthesis of Difluorodiazirine and the Absolute Reactivity of Difluorocarbene

Difluorodiazirine was generated by the reaction of 2,4-dinitrophenoxyfluorodiazirine with lithium fluoride and 15-crown-5 in HMPA. Laser flash photolysis of difluorodiazirine afforded difluorocarbene (CF2). Absolute rate constants and activation parameters were determined for the additions of CF2 to several alkenes.
Synthesis and computational evaluation of a boronium ion analogue of the tropane ring system

Abstract Reaction of bromoborane-dimethylsulfide with homopiperazine results in direct formation of a boronium ion analog of the tropane ring system. Calculations at the DFT/6–31G∗ level confirm the structural similarity of the two systems, and provide insight into the stability of the boronium ion in aqueous solutions.
Near-airport distribution of the environmental costs of aviation

Abstract Aircraft noise, air quality, and climate change damages are spatially and temporally heterogeneous. While policymakers often focus on aggregate cost-benefit analysis to examine tradeoffs in aviation environmental policy, these analyses do not always indicate who bears the costs or who gains the benefits of aviation. We model both the net cost and distribution of environmental damages from one year of aviation operations across the three environmental domains. We find that populations living at airport boundaries face damages of $100–400 per person per year from aircraft noise and between $5–16 per person per year from climate damages (in 2006 dollars). Expected damages from air quality are dependent on the number of operations at the airport and range from $20 to over $400 per person per year with air quality damages approaching those of noise at high volume airports. Mean expected noise and air quality damages decay with distance from the airport, but for noise, the range of expected damages at a given distance can be high and depends on orientation with respect to runways and flight patterns. Damages from aviation-induced climate change dominate those from local air quality degradation and noise pollution further away from the airport. However, air quality damages may exceed those from climate when considering the impact of cruise emissions on air quality.
California parents' preferences and beliefs regarding school-based sex education policy.

CONTEXT: Policy debates over the merits of abstinence-only versus comprehensive approaches to sex education are ongoing, despite well-documented public support for comprehensive sex education. Although parents are key stakeholders in the outcomes of these debates, their views have been less thoroughly considered. METHODS: A random digit dial survey of 1,284 California parents was conducted in 2006. Parents were asked about their sex education policy preferences, the importance of teaching selected topics at different grade levels and reasons for their preferences. Cross-tabulations and odds ratios were used to assess regional and other subgroup differences. RESULTS: Overall, 89% of parents reported a preference for comprehensive sex education, and 11% for abstinence-only education. Support for comprehensive sex education was high in all regions (87–93%) and across all subgroup characteristics: race or ethnicity (79–92%), age (86–94%), education (84–93%), household income (87–92%), religious affiliation (86–91%), religious service attendance (69–96%) and ideological leaning (71–96%). Four types of reasons for preferences emerged: those focused on the consequences of actions, on the importance of providing complete information, on the inevitability of adolescents’ engaging in sex and on religious or purity-based morality concerns. While 64% of abstinence-only supporters cited the last type (absolutist reasons), 94% of comprehensive sex education supporters cited one of the first three (pragmatic reasons). CONCLUSIONS: The high levels of support for comprehensive sex education across California’s diverse regions and demographic subgroups suggest that such support may be generalizable to communities and school districts both in California and around the country. Furthermore, ideological differences might be less important to the sex education debates than the distinction between pragmatic and absolutist perspectives.
Isolation and characterization of the major apolipoprotein from chicken high density lipoproteins.

High density lipoproteins were isolated from plasma of white Leghorn hens by ultracentrifugal flotation between densities 1.063 and 1.210 g/ml. After delipidation, the lipid-free proteins were fractionated by chromatography on Sephadex G-150 in urea; one major apolipoprotein was isolated and characterized. From its chemical, physical and immunochemical properties, the major apoprotein from hen high-density lipoproteins has characteristics similar to the major apoprotein of human high density lipoproteins, apoA-I. Thus the hen protein has been designated hen apoA-I. Hen apoA-I has a molecular weight of approximately 28 000 as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Its calculated molecular weight from its 234 constituent amino acids is 26 674. Hen apoA-I differed from its human counterpart by containing isoleucine. Treatment of hen apoA-I with carboxypeptidase A yielded a COOH-terminal sequence of Leu-Val-Ala-Gln. Automatic Edman degradation of the apoprotein gave an NH2-terminal sequence of Asp-Glu-Pro-Gln-Pro-Glu-Leu. Hen apoA-I had a circular dichroic spectrum typical of α-helical structures; the calculated helicity was 90%. Goat antisera prepared to hen apoA-I formed precipitin lines of complete identity to the hen apoprotein but lines of only partial identity to human apoA-I. These studies show that the major apoprotein from hen and human high-density lipoproteins have similar properties to each other suggesting a common physiologic function.
Effect of a Perfluorochemical Emulsion on the Rat Hepatic Mixed Function Oxidase System

— The perfluorochemical components of synthetic oxygen transporting emulsions may persist in hepatic tissue. After a single 30% blood exchange with the perfluorochemical emulsion, Fluosol-DA 20%, the effects on the microsomal metabolism of 7-methoxycoumarin and 7-ethoxycoumarin were studied over a 9 week period. Fluosol-DA treated animals were compared with controls (sham) and hetastarch-treated controls. Changes in dealkylase activities were compared with induction by phenobarbitone and 3-methylcholanthrene. The liver to body weight ratio increased by 49% in Fluosol-DA-treated rats over the controls at 1 week and the microsomal protein was increased in the Fluosol-DA-treated rats after 4 and 9 weeks. Fluosol-DA treatment induced 7-methoxycoumarin demethylase with peak differences occurring at 1 week and a Vmax 75% greater than controls. Fluosol-DA was a more potent inducer of demethylase than phenobarbitone. In addition, 7-ethoxycoumarin de-ethylase was induced by Fluosol-DA with a peak induction at 4 weeks. The Vmax at 4 weeks in Fluosol-DA-treated rats was 122% greater than control. In this case, Fluosol-DA produced less induction in de-ethylase than 3-methylcholanthrene. These studies show that Fluosol-DA induces more than one form of cytochrome P450 and the effects resemble those of phenobarbitone more than those of 3-methylcholanthrene. Hetastarch, a plasma expander, did not affect liver weights, microsomal protein content, or the cytochrome P450 system.
Kinetic basis for interfacial catalysis by phospholipase A2.

Publisher Summary Interracial catalysis is an obligatory mode of action of enzymes whose natural substrates show a propensity to form organized interfaces. Accordingly, catalytic turnover, by virtually all lipolytic enzymes, occurs at the interface of organized aggregates formed in aqueous dispersions of amphipathic and “lipidic” substrates. This chapter discusses the kinetics of interfacial catalysis by a water-soluble lipolytic enzyme that must attach to the substrate aggregate as a prerequisite for catalytic turnover. It focuses on a class of 14-kDa secreted phospholipases A2 (PLA2) that catalyze the hydrolysis of the sn-2-acyl chain of naturally occurring phospholipids to form lysophospholipids and fatty acids. In describing the kinetic behavior of PLA2, the emphasis here is on the formulation of experimentally testable questions and on the design of strategies and protocols necessary to resolve the primary rate and equilibrium parameters. Because only a few interfacial enzymes have been adequately characterized, the formalism developed here should be considered as a prototype to build a general conceptual understanding of the kinetic and molecular aspects of interfacial catalysis by membrane-bound proteins.
Evaluation of rheumatoid factor tests.

Fourteen (4 per cent) of 340 blood donors showed the presence of rheumatoid factor and some of these were studied in detail. One young donor with very high titers of rheumatoid factor and a 22S component, followed for over two years, has shown no clinical evidence of disease. The sensitized human cell test compares favorably with latex reagent. Both methods are more sensitive and less specific than the sensitized sheep cell test. Inter 340 donatores de sanguine, 14 (i.e. 4 pro cento) monstrava le presentia de factor rheumatoide, e plures de istes esseva studiate in detalio. Un juvene donator con altissime titros de factor rheumatoide e un componente 22S monstrava nulle signo de morbo durante plus que duo annos de abservation. Le test a sensibilisate cellulas human es nullemente minus bon que le test a latex. Ambe iste tests es plus sensibile e minus specific que le test a sensibilisate cellulas ovin.
Tissue culture‐induced morphological somaclonal variation in St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]

Somaclonal variation has been observed in many plant species and is an alternative way to create variants and expand the germplasm pool. A large scale tissue culture experiment was conducted with St. Augustinegrass, an important turfgrass species for the southern USA, to induce somaclonal variation to enlarge the germplasm pool for breeding efforts. Using an improved protocol, approximately 7900 St. Augustinegrass plants were regenerated from cv. Raleigh, and 119 morphological variants were identified. Among the variants, 115 had a semi-dwarf growth habit with shorter and narrower leaves, and shortened internodes and stolons. However, 100 of them showed little vigour, which either grew very slowly or did not survive. The remaining 15 showed reasonable growth vigour and were further investigated in the field. Among them, 13 were semi-dwarf and 2 had longer leaves. In addition, 2 other variants, with variegated (yellow striping) leaves, or significantly thicker stems were also observed and characterized. The altered traits in the variant lines were stable during vegetative propagation and when grown in different environments.
The Role of Technology Management in the Dynamics of Greenhouse Gas Emissions From Household Energy Use in Sub-Saharan Africa:

The authors analyzed the dynamics of greenhouse gas (GHG) emissions from household fuel use in sub-Saharan Africa from 2000 to 2050. The scenarios included a business-as-usual (BAU) scenario, in which fuel consumption and tree-harvesting practices change little except through population growth and urbanization, and large-scale shifts to charcoal- and petroleum-based fossil fuels. The authors also considered the role of charcoal production technologies and sustainability of biomass harvesting. GHG emissions from the various scenarios varied by a factor of 4, with the lowest emissions in the BAU fuel-use scenario with charcoal production and sustainable biomass harvesting and the highest in the charcoal fuel scenario without sustainable harvesting and charcoal production. In only two scenarios, those with sustainable biomass harvesting and charcoal production, the emissions had an inverted-U pattern. Therefore, an inverted-U pattern was highly dependent on technology and policy instruments.
Phencyclidine and psychotomimetic sigma opiates: recent insights into their biochemical and physiological sites of action.

Abstract Phencyclidine (PCP) and certain benzomorphan opiates have strong schizophrenia-like psychotomimetic effects in humans. Recent biochemical and physiological studies have identified two separate receptors in the brain with which PCP and benzomorphan drugs interact: the PCP receptor and the sigma receptor. The PCP receptor seems to be associated with an ion channel that is chemically gated by the N-methyl-d-aspartate-selective glutamate receptor, while the sigma receptor may be involved in presynaptic modulation of catecholamine release. Molecular and physiological studies of the two receptors promise to yield important new insights into the mechanisms of drug-induced psychoses, and may yield clues about the pathogenesis of endogenous psychotic disorders.
Restricted list coloring and Hall's condition

If L is a list assignment of colors to the vertices of a graph G of chromatic number χ(G), a certain condition on L and G, known as Hall's condition, which is obviously necessary for G to have an L-coloring, is known to be sufficient if and only if each block of G is a clique. We show that if the set of colors from which the lists are drawn has size χ(G) then there exist graphs G for which Hall's condition is sufficient for an L-coloring even though not every block of G is a clique. But if the set of colors has size greater than χ(G), then Hall's condition is again sufficient if and only if each block of G is a clique.
A STRUCTURAL MODEL OF SOCIAL SECURITY'S DISABILITY DETERMINATION PROCESS

We estimate a multistage sequential logit model reflecting the structure of the disability determination process of the Social Security Administration (SSA). The model is estimated using household survey information exact-matched to SSA records on disability adjudications from 1989 to 1993. Under program provisions, different criteria dictate outcomes at different steps of the determination process. We find that, without the multistaged structural approach, effects of many important health, disability, and vocational factors are not readily discernible. As a result, split-sample predictions of overall allowance rates from the sequential model perform considerably better than do those for the conventional allowed/denied logit regression.
Reducing sedentary behavior in minority girls via a theory‐based, tailored classroom media intervention

Objective.To develop, implement and test an innovative, theory-based classroom media intervention known as Get Moving! to increase physical activity and decrease sedentary behaviors in predominantl...
Evidence of Improved Regional Myocardial Function in Patients With Chronic Stable Angina and Apparent Normal Ventricular Function—A Tissue Doppler Study Before and After Percutaneous Coronary Intervention

Background The aim of this study was to determine the impact of percutaneous coronary intervention (PCI) on myocardial function assessed by tissue Doppler echocardiography. Methods Myocardial tissue peak velocities were recorded at the lateral, septal, posterior, and inferior angles of the mitral annulus as well as at the lateral tricuspid annulus by pulsed-wave tissue Doppler echocardiography before PCI, as well as 1 day and 6 weeks after intervention. Results Twenty-four consecutive patients with chronic stable angina and preserved systolic left ventricular function (20 men; mean age, 64 ± 9 years) undergoing PCI were studied. Compared with preinterventional values, early diastolic velocities improved at all sites ( P P Conclusions Tissue Doppler parameters of diastolic and systolic function improve early after successful PCI, and this effect persists to 6 weeks after intervention.
Semidiurnal Variations in the Budget of Angular Momentum in a General Circulation Model and in the Real Atmosphere

Abstract Diurnal and semidiurnal variations in the budget of atmospheric angular momentum are evident in a simulation by the NCAR Community Climate Model (CCM2). These variations depicted with 20-min time resolution (each time step) are used as guides to study similar variations determined from 6-hourly NCEP/NCAR Reanalysis data. A semidiurnal variation in relative angular momentum and in angular momentum related to solid body rotation of the atmosphere is found in the reanalysis. Although there is evidence that both frictional and gravity-wave drag torques play roles, the effects of semidiurnal variations in mountain torque, resulting from the migrating semidiurnal pressure wave, are most thoroughly documented.
Structure of Integrin, a Glycoprotein Involved in the Transmembrane Linkage between Fibronectin and Actin

We describe the isolation, characterization, and sequence of cDNA clones encoding one subunit of the complex of membrane glycoproteins that forms part of the transmembrane connection between the extracellular matrix and the cytoskeleton. The cDNA sequence encodes a polypeptide of 89 kd that has features strongly suggesting the presence of a large N-terminal extracellular domain, a single transmembrane segment, and a small C-terminal cytoplasmic domain. The extracellular domain contains a threefold repeat of a novel 40 residue cysteine-rich segment, and the cytoplasmic domain contains a tyrosine residue that is a potential site for phosphorylation by tyrosine kinases. We propose the name integrin for this protein complex to denote its role as an integral membrane complex involved in the transmembrane association between the extracellular matrix and the cytoskeleton.
Prediction of Success in an Applied M.A. Psychology Program.

This study investigated the extent to which various traditional measures (test scores, undergraduate GPA, and letters of recommendation) and less traditional measures (interview ratings and biographical information) would predict each of two criteria of success in a subdoctoral program in applied psychology: (a) academic competency defined as grade point average (GPA) in graduate school, and (b) faculty ratings of selected interpersonal skills.The traditional measures were significantly but modestly related to academic competency. The use of biographical information and interview ratings was supported in selecting for interpersonal skills. Ratings of letters of recommendation failed to show a relationship to either GPA or ratings of interpersonal skills.
Tracking ex vivo-expanded CD4+CD25+ and CD8+CD25+ regulatory T cells after infusion to prevent donor lymphocyte infusion-induced lethal acute graft-versus-host disease

Abstract Donor bone marrow (BM)-derived CD4+CD25+ regulatory T cells, maturing in the host thymus, are critical in inhibiting graft-versus-host disease (GVHD) after donor lymphocyte infusion (DLI) in murine BM chimeras. Data presented here demonstrate that fresh CD25+ cells isolated from donor-type mice can be expanded ex vivo by a variety of methods. Ex vivo-expanded CD4+CD25+ and CD8+CD25+ cells were potent suppressors of donor response to host alloantigens in mixed lymphocyte reaction assays. Both fresh and ex vivo-expanded CD4+CD25+ cells persisted long-term in vivo and effectively prevented DLI-induced GVHD in CD25−/− BM chimeras. Importantly, co-infused CD4+CD25+ cells with DLI cells migrated to peripheral lymphoid organs and survived long-term in DLI-treated CD25−/− chimeras, but not in DLI-treated CD25+/+ chimeras, indicating homeostatic control of CD25+ cells and an available niche required for their long-term persistence. Furthermore, maintenance of CD25 expression seemed necessary for suppressive function, because only the CD25+ cell fraction, but not the CD25− fraction isolated after adoptive transfer, was suppressive in vitro. Ex vivo-expanded CD8+CD25+ cells weakly prevented GVHD, apparently because of a rapid disappearance of these cells after adoptive transfer. Taken together, these data suggest that the therapeutic use of ex vivo-expanded CD4+CD25+ cells may be a feasible, nontoxic modality for controlling GVHD in the clinic. Because of strict homeostatic control, an available niche may be required for long-term persistence of infused regulatory T cells.
Fluid Exchange across a Meandering Jet Quasiperiodic Variability

In this paper, the motion of fluid parcels in the two-dimensional kinematic model of a meandering jet developed by Bower and Samelson is studied. The earlier work is extended by considering quasiperiodic spatiotemporal variability in a reference frame moving with the phase speed of the meander. This necessitates the introduction of recently developed techniques in dynamical systems theory for analyzing transport in velocity fields with quasiperiodic variability. A detailed comparison between exchange for variability with one and two independent frequencies is given, and it is shown that the exchange rates may be very different for periodic and quasiperiodic variability.
Decision Tree Learning from Incomplete QoS to Bootstrap Service Recommendation

Collaborative Filtering (CF) has been increasingly employed as an effective vehicle for providing personalized service recommendations in service computing. CF exploits historical user-service interaction information to predict the preference of service users. A key challenge faced by CF is to handle new users with no previous interaction information. We present a novel strategy that integrates Matrix Factorization (MF) with decision tree learning to bootstrap service recommendation systems. The proposed strategy first employs MF to partition existing users into a set of user groups. In practice, only a small amount of user-service interaction information is observed. The MF based user partitioning scheme also provides a way to estimate the missing interaction information based on the group structure. The tree learning algorithm then leverages these estimated information and exploits user groups as class labels to learn a decision tree. Few highly discriminative services are identified as tree nodes to adaptively query a new user based on the interaction results with the prior services in the tree. Through a short and intuitive bootstrapping process, the new user is classified into one of the user groups, via which the user's preference is predicted. We conduct a set of experiments on real-world service data to demonstrate the effectiveness of the proposed bootstrapping strategy.
Shielding Nozzle Design and Analysis for Atomization-Based Cutting Fluid Systems in Micromachining

Atomization-based cutting fluid systems (ACFs) are increasingly being used in micromachining applications to provide cooling and lubrication to the tool–chip interface. In this research, a shielding nozzle design is presented. A computational fluid dynamic model is developed to perform parameter analysis of the design. The numerical simulations were accomplished using the Eulerian approach to the continuous phase and a Lagrangian approach for droplet tracking. Based on the results of the simulations it is determined that the shielding nozzle is effective at providing droplets to the cutting surface at an appropriate speed and size to create a lubricating microfilm.
Calculation of the efficiency of ultraviolet screeners in plastics

Calculation of the effect of light absorbers (UV screeners) on the photochemistry of polymers shows that a critical factor in reducing the rate of photodegradation is the thickness of the actual degraded layer. When the degradation is confined to a zone within a few microns of the exposed surface, the efficiency of light absorption as a stabilization mechanism is greatly reduced. The relative absorptivity of the base resin and pigment loadings are calculated to have a minor effect on stabilization efficiency for polymers having thin layers of degradation.
The expression of cytokine activity by fracture callus

Cytokines, a group of proteins known to regulate hemopoietic and immune functions, are also involved in inflammation, angiogenesis, and bone and cartilage metabolism. Since all of these processes occur following bone injury, or are known to contribute to wound repair mechanisms, this investigation sought to test the hypothesis that cytokines are involved in fracture healing. Two sets of 60 male Sprague-Dawley rats underwent the production of standard closed femoral fractures. The animals were then euthanized in groups of 15 on days 3, 7, 14, and 21 postfracture. A separate control group was also used for the harvesting of intact unfractured bone. At the time of euthanasia, calluses or bone specimens were explanted to organ culture and treated with either media alone or media containing the inducing agents lipopolysaccharide or concanavalin A. A titration of conditioned medium from these cultures was then added to factor-dependent clonal cell lines that are known to be specifically responsive to interleukin-1, interleukin-6, granulocyte-macrophage colony stimulating factor or macrophage-colony stimulating factor. To confirm the identities of each of these cytokines, neutralizing antibody studies were performed. The results showed that interleukin-1 is expressed at very low constitutive levels throughout the period of fracture healing but can be induced to high activities in the early inflammatory phase (day 3). Granulocyte-macrophage colony stimulating factor showed no constitutive activity but could also be induced to high activities with lipopolysaccharide. The ability of these two cytokines to be induced declined progressively as fracture healing proceeded. Interleukin-6 showed high constitutive activity early in the healing process (day 3), and treatment with inducing agent did not increase the activity of this cytokine at this timepoint. Lipopolysaccharide did increase interleukin-6 activity in day 7 and 14 fracture calluses. Although macrophage-colony stimulating factor is thought to be involved in a variety of metabolic bone conditions, it could not be detected or induced from any of the callus samples. Moreover, none of the samples of unfractured bone showed constitutive or inducible activities for any of these cytokines. A separate experiment in which calluses and samples of unfractured bone from similar cultures were examined histologically and tested for DNA or protein synthesis at two timepoints in the culture period (days 1 and 4) showed that tissue viability was maintained. Thus the inability to detect macrophage colony-stimulating factor in fracture callus or any cytokine activity in unfractured bones was not due to cell death. These findings suggest that the occurrence of a fracture results in a cascade of events that includes the production of cytokines. The time-dependent expression of specific cytokine activities, which are differentially regulated, supports the concept that fracture healing may be partially mediated by these factors. (J Bone Miner Res 1995 ;10 :1272-1281)
Effectiveness of Nuclear Weapons against Buried Biological Agents

This report describes the results of some calculations on the effectiveness of penetrating nuclear weapons of yield 1 and 10 kilotons against targets containing biological agents. The effectiveness depends in detail on the construction of the bunkers, on how the bioagents are stored, on the location of the explosions with respect to the bunkers, the bioagent containers and the surface of the ground, and on the yield of the explosion and the geology of the explosion site. Completeness of sterilization of the bioagents is crucial in determining effectiveness. For most likely cases, however, complete sterilization cannot be guaranteed. Better calculations and experiments on specific target types would improve the accuracy of such predictions for those targets, but significant uncertainties would remain regarding actual geology, actual target layouts, and the position of the explosion with respect to the target. Based on preliminary calculations, casualties from the aboveground effects of underground nuclear ...
Phospholipid Component Volumes: Determination and Application to Bilayer Structure Calculations

We present a new method for the determination of bilayer structure based on a combination of computational studies and laboratory experiments. From molecular dynamics simulations, the volumes of submolecular fragments of saturated and unsaturated phosphatidylcholines in the liquid crystalline state have been extracted with a precision not available experimentally. Constancy of component volumes, both among different lipids and as a function of membrane position for a given lipid, have been examined. The component volumes were then incorporated into the liquid crystallographic method described by Wiener and White (1992. Biophys. J. 61:434-447, and references therein) for determining the structure of a fluid-phase dioleoylphosphatidylcholine bilayer from x-ray and neutron diffraction experiments.
A stabilized nodally integrated tetrahedral

A stabilized, nodally integrated linear tetrahedral is formulated and analysed. It is well known that linear tetrahedral elements perform poorly in problems with plasticity, nearly incompressible materials, and acute bending. For a variety of reasons, low-order tetrahedral elements are preferable to quadratic tetrahedral elements; particularly for nonlinear problems. But the severe locking problems of tetrahedrals have forced analysts to employ hexahedral formulations for most nonlinear problems. On the other hand, automatic mesh generation is often not feasible for building many 3D hexahedral meshes. A stabilized, nodally integrated linear tetrahedral is developed and shown to perform very well in problems with plasticity, nearly incompressible materials and acute bending. The formulation is analytically and numerically shown to be stable and optimally convergent for the compressible case provided sufficient smoothness of the exact solution u ∈ C2 ∩ (H1)3. Future work may extend the formulation to the incompressible regime and relax the regularity requirements; nonetheless, the results demonstrate that the method is not susceptible to locking and performs quite well in several standard linear and nonlinear benchmarks. Published in 2006 by John Wiley & Sons, Ltd.
Boosting Methods for Protein Fold Recognition: An Empirical Comparison

Protein fold recognition is the prediction of protein's tertiary structure (Fold) given the protein's sequence without relying on sequence similarity. Using machine learning techniques for protein fold recognition, most of the state-of-the-art research has focused on more traditional algorithms such as support vector machines (SVM), k-nearest neighbor (KNN) and neural networks (NN). In this paper, we present an empirical study of two variants of boosting algorithms - AdaBoost and LogitBoost for the problem of fold recognition. Prediction accuracy is measured on a dataset with proteins from 27 most populated folds from the SCOP database, and is compared with results from other literature using SVM, KNN and NN algorithms on the same dataset. Overall, boosting methods achieve 60% fold recognition accuracy on an independent test protein dataset which is the highest prediction achieved when compared with the accuracy values obtained with other methods proposed in the literature. Boosting algorithms have the potential to build efficient classification models in a very fast manner.
Alkyne mechanochemistry: putative activation by transoidal bending

We investigated the use of mechanical stress to bend carbon–carbon triple bonds. Formation of an isoquinoline after reaction with a benzyl azide trap points towards a nucleophilic addition mechanism, differentiating mechanochemical trans-bending of π bonds from the typical reactivity observed for cisoidal bending of triple bonds in strained cyclic alkynes.
Detection of rat parvovirus type 1 and rat minute virus type 1 by polymerase chain reaction

Two newly recognized parvovirus species, rat parvovirus 1 (RPV-1) and rat minute virus 1 (RMV-1), were recently identified in naturally infected rats. In this study, two polymerase chain reaction (PCR) assays were developed to specifically detect RPV-1 and RMV-1. The RPV-1 PCR assay amplified the expected 487-bp deoxyribonucleic acid (DNA) fragment only in the presence of RPV-1 DNA; the RMV-1 PCR assay amplified the expected 843-bp product only from RMV-1 DNA, not from other rodent parvoviruses. The RPV-1 and the RMV-1 PCR assays detected approximately 18 and 70 copies of DNA template, respectively. These two PCR assays were shown to be sensitive, specific and rapid methods for detecting RPV-1 and RMV-1 infections in rats. These assays may also be valuable for evaluation of biological specimens for parvovirus contamination.
Studies on the Memory Capacity and Robustness of Chaotic Dynamic Neural Networks

A dynamical neural model that is strongly biologically motivated is applied to learning and retrieving binary patterns. This neural network, known as Freeman's K-sets, is trained with Hebbian rule and habituation to memorize the input patterns by associating them with an attractors formed in the state space. After the patterns are memorized noisy input is given to the network to recover the original. We compare the results of this recall for a different number of memories and compare them with performance of the Hopfield model. We show capacity of the dynamical system exceeds that of the Hopfield network and the noisy recall degrades at a slower pace as the number of the patterns is growing. Experimental results indicate that the critical load paramter, which gives approximation of the network capacity, is higher in K-model than in the Hopfield network. Significant advantage of K-model is achieved at a larger training set size, when compared to Hopfield model.
Echocardiographic assessment of stentless aortic bioprosthetic valves

Abstract Stentless tissue aortic valves are gaining in popularity because of advantages in hemodynamics and durability compared with stented bioprostheses. The absence of a rigid sewing ring and struts makes these valves pliable, and distortion at implantation can result in valve dysfunction. Because the anatomy and implantation techniques of stentless tissue valves are unlike those of mechanical and stented tissue valves, their echocardiographic appearance is unique on both intraoperative and subsequent transthoracic and transesophageal echocardiography. This report describes the echocardiographic appearance of normally functioning stentless tissue heterograft aortic valves as an aid to their intraoperative and subsequent echocardiographic assessment. (J Am Soc Echocardiogr 2000;13:941-8.)
Is hemodiafiltration ready for broader use

Hemodiafiltration is practiced throughout Europe and in a few additional countries but, because of regulatory restrictions, is not currently available in the United States. Hemodiafiltration removes uremic species more broadly than is achieved by diffusion dialysis, perhaps explaining its better outcome profile.
Effect of as Overpressure on Mn-Induced Layer Disordering in AlGaAs-GaAs Superlattices: An Investigation of the Mn Diffusion Mechanism

Data are presented showing the effect of As overpressure on the diffusion of Mn into an AlGaAs-GaAs superlattice (SL) using MnAs as the diffusion source. Arsenic overpressure has been shown to play a significant role in both impurity-induced layer disordering (IILD) and the microstructure of the Mn-diffused samples. The degree to which layer disordering occurs decreases as As overpressure increases. Furthermore, dislocation loops are observed for the diffusion of Mn under Ga-rich conditions at prolonged diffusion times. Both results, in addition to the effect of As overpressure on the Mn diffusion profile, indicate that Mn diffusion into GaAs or GaAs-AlGaAs heterostructures takes place by an interstitial-substitutional mechanism involving column III vacancies under As-rich conditions and a "kick-out" mechanism involving column III interstitials under Ga-rich conditions.
Epidemic situation and coping strategies of AIDS in Wenling City

[Objective]To analyze the epidemic characteristics and risk factors of HIV/AIDS,and provide scientific evidence for developing AIDS intervention strategies and risk factors intervention in Wenling City.[Methods]The data from AIDS epidemic reporting network and epidemiological survey from 2000-2010 were analyzed.[Results]Since the first HIV case was found in 2000,the total number of HIV antibody positive was 185,with 63 AIDS patients and 20 deaths by the end of 2010.From 2006,the epidemic showed a rapid increasing trend,and the proportion of local infected individuals had increased annually(53.51%).The data showed most infections were male(74.60%) and young adults aged 20-49-year(76.76%),and over the age of 50 accounted for 21.62% showing the AIDS tended to the elder people.The sexual contact(67.65%) was the main route among the 3 kinds of transmission.[Conclusion]The number of HIV/AIDS has increased rapidly with diverse epidemic model in recent years in Wenling City.The epidemic situation has been diffused from the high-risk group to the general population.The department should take effective and comprehensive interventions to control the rapid spread of AIDS.
[Analysis of HIV-1 drug resistance among 1 922 individuals experiencing virological failure of first-line antiretroviral therapy in Henan province].

Objective To study the condition of HIV-1 drug resistance mutation among failures of first-line antiretroviral therapy in Henan province. Method The sub platform of China's legal infectious disease monitoring information reporting system-HIV/AIDS integrated prevention and control data information management system was used to collect the information of patients experiencing first-line antiretroviral treatment failure (virus load≥1 000 copies/ml) more than one year among nine cities of Henan in 2011.A total of 40 cases with no information and 212 cases with incomplete drug resistance results were deleted, and 1 922 cases were included in this study and genotype resistance testing was carried out. Non-conditional logistic regression analysis was used to analyse the influencing factors of drug resistance mutation. Results A total of 1 922 cases were included in the analysis. 1 039 cases were males, 833 cases were females, the age was (45.7±12.1) years, 82.73% (1 590) were married, and 87.93% (1 690) were transmitted by blood. 64.20% (1 234) patients acquired drug resistance. Nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI) resistance mutations were found in 62.59% (1 203), 49.74% (956) and 0.94% (18) of subjects, respectively. 42.09% (809) of patients harbored NRTI and NNRTI resistance mutations synchronously. ≥1TAM was the most commonly emerged NRTI resistance mutation (41.94% (806)), the prevalences of TAM-1 and TAM-2 were 8.48% (163) and 4.24% (81), respectively. K65R/N and Q151M complex existed in 23 and 4 patients, respectively. K103N/S was the most commonly emerged NNRTI resistance mutation (34.32% (659)). Non-conditional logistic regression analysis showed that, factors associated with high drug resistance were the following: transmitted by mother to child (OR=9.05,95%CI: 1.14-72.12), clinical stage was Ⅳ (OR=1.70, 95%CI: 1.09-2.66) and 5-year-treated (OR=1.59,95%CI: 1.03-2.47). Factors associated with low drug resistance were the following: 1-year-treated (OR=0.19, 95%CI: 0.13-0.27). Conclusion Complex patterns of HIV-1 drug resistance mutations were identified among individuals experiencing failure of first-line antiretroviral therapy in Henan province. Factors associated with high drug resistance were lived in Luohe, Shangqiu, Nanyang, Xinyang, transmitted by mother to child, clinical stage was Ⅳ, and 5-year-treated. Key words: Acquired immunodeficiency syndrome; Antiretroviral treatment; Retrospective studies; Drug resistance
Mechanism of oleic acid-induced inhibition on gastric acid secretion in rats

We investigated the existence of an enterogastrone in rats induced by duodenal administration of oleic acid. Acid secretion by the luminally perfused stomach was stimulated in anesthetized rats by intravenous infusion of 0.3 micrograms.kg-1.h-1 pentagastrin. Intraduodenal administration of 3 mmol of oleic acid produced a profound inhibition (94%) of pentagastrin-stimulated acid output in 10 rats (P less than 0.01). Of several peptides in plasma including secretin, neurotensin, somatostatin, and peptide YY, only secretin was found to increase significantly (P less than 0.001). A similar degree of inhibition of acid output (93%) was caused by porcine secretin, 5.6 pmol.kg-1.h-1, given intravenously to mimic the plasma level of secretin produced by oleic acid infusion. The inhibitory effect of oleic acid on the acid secretion was completely reversed by intravenous injection of a rabbit antisecretin serum but not by a normal rabbit serum. These observations strongly suggest that the inhibition was mediated via circulating secretin. The inhibition produced by either oleic acid or secretin was completely blocked by indomethacin. The blocking action was completely reversed by intravenous administration of 48 micrograms.kg-1.h-1 prostaglandin E2. We conclude that endogenous secretin is a major enterogastrone released by oleic acid in anesthetized rats and that the inhibitory action of secretin requires endogenous prostaglandins.
Clinical uses of central venous cannulation.

Central venous cannulation is an important adjunct to medical therapy, but it must be done only under appropriate circumstances and its value must be weighed against the complications that may occur.
Application of Portable X-ray Fluorescence (XRF) for Sorting Commingled Human Remains

Abstract Commingled human skeletal remains present complex challenges for medicolegal investigations. In cases of commingling, it is important to accurately segregate the remains of each individual represented and then make a determination of the number of individuals present. Forensic anthropologists are uniquely qualified to make assessments regarding commingling because they routinely employ laboratory methods such as identifying duplicated skeletal elements, visual and osteometric pair-matching of bilateral elements, evaluation of joint congruity between articular surfaces, skeletal age comparisons, and assessment of corresponding pathological changes and taphonomic modifications between different skeletal elements. Recent research using X-ray fluorescence (XRF) spectrometry has shown promise in determining whether a set of remains belongs to a single or multiple individuals by analyzing elemental concentrations in human bones. One advantage to this approach is that it has the potential to provide an inexpensive, rapid, and nondestructive method for assessing small-scale cases of commingling. The development of portable XRF (pXRF) technology has opened the possibility to apply the method to both complete and fragmentary remains not only in a laboratory setting, but also allowing for analyses in the field.
Max Frisch’s Biedermann und die Brandstifter as the Documentation of an Author’s Frustration

(1971). Max Frisch’s Biedermann und die Brandstifter as the Documentation of an Author’s Frustration. The Germanic Review: Literature, Culture, Theory: Vol. 46, No. 2, pp. 119-128.
Head-based isogeometric analysis of transient flow in unsaturated soils

Abstract An isogeometric analysis (IGA) is introduced to obtain a head-based solution to Richards equation for unsaturated flow in porous media. IGA uses Non-Uniform Rational B-Spline (NURBS) as shape functions, which provide a higher level of inter-element continuity in comparison with Lagrange shape functions. The semi-discrete nonlinear algebraic equations are solved using a combination of implicit backward-Euler time-integration and Newton-Raphson scheme. The time-step size is adaptively controlled based on the rate of changes in the pore pressure. The results from the proposed formulation are compared and verified against an analytical solution for one-dimensional transient unsaturated flow in a homogenous soil column. The proposed method is then applied to four more complex problems including two-dimensional unsaturated flow in a two-layered soil and a semi-circular furrow. The test cases in two-layered soil system involve sharp variations in the pressure gradient at the intersection of the two media, where the pore water pressure abruptly changes. It is shown that the proposed head-based IGA is able to properly simulate changes in pore pressure at the soils interface using fewer degrees of freedom and higher orders of approximation in comparison with the conventional finite element method.
Taxonomy of Shared Autonomous Vehicle Fleet Management Problems to Inform Future Transportation Mobility

This paper presents a taxonomy for classifying vehicle fleet management problems, across several dimensions, to inform future research on autonomous vehicle (AV) fleets. Modeling the AV fleet management problem will bring about new classes of vehicle routing, scheduling, and fleet management problems; nevertheless, the existing literature related to vehicle routing, scheduling, and fleet management is a valuable foundation for future research on the AV fleet management problem. This paper classifies the broadly defined AV fleet management problem by using existing taxonomic categories in the literature; adds additional, or more nuanced, dimensions to existing taxonomic categories; and presents new taxonomic categories to classify specific AV fleet management problems. The broadly defined AV fleet management problem can be classified as a dynamic multivehicle pickup and delivery problem with explicit or implicit time window constraints. Existing studies that fit into this class of fleet management problems...