cssi/SciSciGPT-SciSciNet huggingface dataset:
Linear-programming method for obtaining effective cluster interactions in alloys from total-energy calculations: Application to the fcc Pd-V system.

We developed a method for obtaining effective cluster interactions in substitutional binary alloys from first-principles total-energy calculations. The method reproduces not only the formation energies, but also the ground-state line and relative energies of different structures. These quantities are crucial if the energy parametrization is to be used to compute the temperature-composition phase diagram of the alloy system. We applied the method to the Pd-V alloys, and obtained insight into the energetics of this complex alloy system. We showed that pair cluster interactions of long range (seventh or eighth nearest neighbor) are necessary to reproduce the ground-state line of the fcc Pd-rich superstructures.
Preliminary Design of the High Intensity Synchrotron (HIS) for the Proposed Intense Pulsed Source Facility (IPNS) at Argonne

Feasibility of a synchrotron meeting the requirements is supported by design considerations thus far. The ideas presented above may, of course, change significantly as the design is refined.
Alpha shapes applied to molecular shape characterization exhibit novel properties compared to established shape descriptors.

Despite considerable efforts, description of molecular shape is still largely an unresolved problem. Given the importance of molecular shape in the description of spatial interactions in crystals or ligand-target complexes, this is not a satisfying state. In the current work, we propose a novel application of alpha shapes to the description of the shapes of small molecules. Alpha shapes are parametrized generalizations of the convex hull. For a specific value of α, the alpha shape is the geometric dual of the space-filling model of a molecule, with the parameter α allowing description of shape in varying degrees of detail. To date, alpha shapes have been used to find macromolecular cavities and to estimate molecular surface areas and volumes. We developed a novel methodology for computing molecular shape characteristics from the alpha shape. In this work, we show that alpha-shape descriptors reveal aspects of molecular shape that are complementary to other shape descriptors and that accord well with chemi...
A new iterative algorithm for extrapolation of data available in multiple restricted regions with application to radar imaging

A new iterative method for extrapolation of incomplete segmented data available in multiple separated bands is proposed and tested. The method uses the Burg algorithm to find the linear prediction parameters and an iterative procedure to improve the estimation of the linear prediction parameters and the extrapolation of the data. This method is especially effective when the spectra (Fourier transform of the observed data) are in discrete forms, in the context of radar imaging represented here, this means the objects consist of distinctly spaced scattering centers. The advantages of this algorithm are demonstrated using both numerically generated and realistic experimental data pertaining to high resolution radar imaging.
On overlapping resource management and call setup signaling: a new signaling approach for internet multimedia applications

Interactive multimedia applications combine requirements of traditional telephony services and Internet applications. This requires call setup, call signaling, negotiation, routing, and network resources. However, in dynamic network environments resources are not protected unless the applications reserve them for the multimedia session. To provide quality of service (QoS) control, the subject of the interaction of call signaling and resource management have addressed resource reservation during the call setup phase. Usually, the rule is to use the traditional telephony-style call setup model (i.e. users are only alerted after all resources have been successfully reserved for the call). In the Internet, however, this may incur in long call setup delays and a high call blocking rate ('no QoS/no call'). In order to provide users with a practical and fast way to reserve resources during session setup, we investigate a different call setup model than that of traditional telephony. Our model allows users to be alerted while the resource reservation takes place, thus, taking advantage of parallel user answering delays and reservation delays. For this to occur efficiently, we use existing elements of the Session Initiation Protocol (SIP) to provide means for independent call setup and resource management transactions and flow negotiation. Based on experimental comparisons obtained in a multimedia call, we demonstrate that the proposed approach reduces the impact of the reservation delays, with maximum call setup delay improvements when we have approximate values of reservation and answering delays.
Atmospheric pyrolysis of carbohydrates with thermogravimetric and mass spectrometric analyses

Abstract The pyrolysis of glucose, maltose, cellobiose, amylose and cellulose was studied by thermogravimetry between 250–400°C at atmospheric pressure in helium. The thermogravimetric analyzer was coupled with a mass spectrometer and the evolving gases were continuously monitored. Between 2.6 and 2.8 moles of water were obtained for every hexose unit. For amylose and cellulose the water formation was in one step; for the other carbohydrates, varying amounts of water formed in two different steps. The scans were evaluated by computer and the concentrations of the possible components were plotted versus temperature. The correlation of these curves with the weight loss curve throws new light on carbohydrate pyrolysis reactions.
Detection of 8-oxo-2'-deoxyguanosine, a marker of oxidative DNA damage, in culture medium from human mesothelial cells exposed to crocidolite asbestos

Crocidolite asbestos is associated with the development of mesothelioma. Although chromosomal changes have been documented in mesothelial cells, the mechanisms of interaction of crocidolite with DNA remain obscure. Since human mesothelial cells are exquisitely sensitive to asbestos, oxidative DNA damage was measured in an asbestos-exposed human mesothelial cell line (MET5A) by assaying oxidized guanine bases [8-oxo-2'-deoxyguanosine (oxo 8 dG), 8-oxoguanine (oxo 8 G), and 8-oxoguanosine (oxo 8 Gua)] excreted into the spent culture medium after DNA repair or turnover. At growth inhibitory, but not cytolytic concentrations, asbestos caused significant elevation of all bases in the spent medium over a 48-h period. In contrast, riebeckite, a chemically similar, nonfibrous analog of crocidolite did not cause increased adduct release. Results show that oxidative RNA and DNA bases are produced in response to asbestos in target cells of asbestos-induced cancers.
Effects of exercise training on tumor hypoxia and vascular function in the rodent preclinical orthotopic prostate cancer model

Regular physical exercise is considered to be an integral component of cancer care strategies. However, the effect of exercise training on tumor microvascular oxygenation, hypoxia, and vascular fun...
Corticosteroid-induced hypersensitivity reactions

Objective To review and present data on the prevalence, clinical manifestations, diagnostic techniques, and management options in patients with hypersensitivity reactions to corticosteroid preparations. Data Sources All English language articles pertaining to human subjects were reviewed using the Pubmed database from 1964 to June 2002. Indexing terms used were anaphylaxis OR allergic OR anaphylactoid OR hypersensitivity AND steroid OR corticosteroid. Further cross-references were obtained after reviewing articles from the aforementioned search. Study Selection A total of 11,493 articles were identified with the above search terms. Only those articles, including letters and editorials, describing systemic reactions to steroids were included in the review. Excluded from our review were articles dealing with contact dermatitis to topical steroid preparations. This resulted in a total of 80 articles which were reviewed. Results Although rare, steroid-induced hypersensitivity reactions do occur. They range from minor rashes to the more serious cardiovascular collapse. The mechanisms of steroid-induced adverse events vary from patient to patient, some being classic immunoglobulin E-mediated whereas others are pseudoallergic in nature. Skin testing and provocative challenges offer two ways to diagnose such reactions. Treatment consists of substituting the steroid with an alternative preparation which can be tolerated by the patient. Conclusions Although little is known about the epidemiology of steroid-induced hypersensitivity, because most data are derived from case reports, it is clear that steroid-induced hypersensitivity is a heterogeneous entity, with no single uniform mechanism. A great deal of work still needs to be done so that the pathogenesis of such adverse events can be clearly determined and effective therapeutic interventions devised.
A Role for Fucose α(1−2) Galactose Carbohydrates in Neuronal Growth

We report a fucose α(1−2) galactose-mediated pathway for the modulation of neuronal growth and morphology. Our studies provide strong evidence for the presence of Fucα(1−2)Gal glycoproteins and lectin receptors in hippocampal neurons. Additionally, we show that manipulation of Fucα(1−2)Gal-associated proteins using small-molecule and lectin probes induces dramatic changes in neuronal morphology. These findings may provide a novel pathway to stimulate neuronal growth and regeneration.
Numerical modeling of high-temperature corrosion processes

Numerical modeling of the diffusional transport associated with high-temperature corrosion processes is reviewed. These corrosion processes include external scale formation and internal subscale formation during oxidation, coating degradation by oxidation and substrate interdiffusion, carburization, sulfidation and nitridation. The studies that are reviewed cover such complexities as concentration-dependent diffusivities, cross-term effects in ternary alloys, and internal precipitation where several compounds of the same element may form (e.g., carbides of Cr) or several compounds exist simultaneously (e.g., carbides containing varying amounts of Ni, Cr, Fe or Mo). In addition, the studies involve a variety of boundary conditions that vary with time and temperature. Finite-difference (F-D) techniques have been applied almost exclusively to model either the solute or corrodant transport in each of these studies. Hence, the paper first reviews the use of F-D techniques to develop solutions to the diffusion equations with various boundary conditions appropriate to high-temperature corrosion processes. The bulk of the paper then reviews various F-D modeling studies of diffusional transport associated with high-temperature corrosion.
Potent and selective inhibition of A-to-I RNA editing with 2'-O-methyl/locked nucleic acid-containing antisense oligoribonucleotides.

ADARs (adenosine deaminases acting on RNA) are RNA editing enzymes that bind double helical RNAs and deaminate select adenosines (A). The product inosine (I) is read during translation as guanosine (G), so such changes can alter codon meaning. ADAR-catalyzed A to I changes occur in coding sequences for several proteins of importance to the nervous system. However, these sites constitute only a very small fraction of known A to I sites in the human transcriptome, and the significance of editing at the vast majority sites is unknown at this time. Site-selective inhibitors of RNA editing are needed to advance our understanding of the function of editing at specific sites. Here we show that 2′-O-methyl/locked nucleic acid (LNA) mixmer antisense oligonucleotides are potent and selective inhibitors of RNA editing on two different target RNAs. These reagents are capable of binding with high affinity to RNA editing substrates and remodeling the secondary structure by a strand-invasion mechanism. The potency obser...
Pharmacologic correlation between local anesthetic-induced myotoxicity and disturbances of intracellular calcium distribution.

Abstract The local anesthetic mepivacaine and various other drugs known to perturb sarcoplasmic calcium metabolism and/or sarcolemmal sodium conductance were injected into the gastrocnemius or subcutaneously over the gracilis muscles of rats. After 48 hr, the tissues were examined histologically, and muscle damage was rated on a single-blind basis. Following im administration, all of the agents tested which are capable of increasing the intracellular concentration of free calcium—mepivacaine-HCl, quinidine gluconate, A23187, caffeine, and 2,4-dinitrophenol-produced extensive and qualitatively similar myonecrosis. Damage to skeletal muscle was absent or negligible after im injection of control saline solutions or tetrodotoxin, a drug that blocks sodium channels without directly influencing the intracellular calcium distribution. The sc administration of mepivacaine caused extensive damage to fibers approximating the muscle surface, while saline was without effect. To assess the influence of a calcium antagonist on local anesthetic-induced myonecrosis, verapamil-HCl was administered sc, both alone and in combination with mepivacaine. Although verapamil by itself resulted in some minor surface injury, it almost completely blocked the damage produced by mepivacaine. It is concluded that the myotoxicity of local anesthetics is related to a disturbance of intracellular calcium homeostasis rather than to an influence on sarcolemmal sodium conduction.
Why are only some basal plane dislocations converted to threading edge dislocations during SiC epitaxy

Dislocations were tracked from 4H-SiC epilayer to the substrate by a new method based on combination of molten KOH etching and Reactive Ion Etching. It was found that basal plane dislocations (BPDs) with dislocation lines parallel (or approximately parallel) to the off-cut direction might propagate as BPDs into the epilayer, while those with dislocation lines forming large angles (>10o) with the off-cut direction will get converted to threading edge dislocations (TEDs). A model is proposed to explain the observations.
Cell requirements for optimum proliferative responses of rat spleen cells.

Abstract Spleen cells from New Zealand black rats (NBR) were separated by nylon wool (NW) and by density gradient centrifugation (Percoll) to identify certain physical, chemical, morphological and functional attributes of mononuclear cells. Density distribution profiles of nylon wool nonadherent (NA) and adherent (ADH) cells indicated that at least two different populations of spleen cells existed (NA = 1.070–1.075 g/ml; ADH = 1.064 g/ml). 38% of all NA cells and 13 % of all ADH cells are T-cells (mean density = 1.080 g/ml). Nonspecific esterase staining indicated gradient enrichment of ADH cells at densities of 1.064 g/ml (mononuclears) and 1.080 g/ml (polymorphonuclears). NA cells contained 3 % esterase positive cells. Plastic adherent cells had a mean density distribution of 1.064 g/ml. Mitogen binding cells were identified by function and density. ADH cells (1.064 g/ml) demonstrate higher specific binding of PHA-I 125 compared to NA cells (1.072 g/ml). Unlike the PHA binding cells, Con-A binding ADH and NA cells share the same mean densities (1.055–1.064 g/ml). As with the PHA responses, ADH cells have greater specific binding activities for Con-A than NA cells. Mitogen binding cells have lower mean densities than cells which incorporate tritiated thymidine at 5 days post-cultivation with PHA or Con-A. Adherent cells enriched for T cells and polymorphonuclears produced the highest PHA responses. PHA responsive NA cells were not enriched by gradient separation. NA cells produced a suppressive effect when mixed with cells which produced optimum PHA responses. ADH cells (density 1.073 g/ml) produced a significant PHA response helper effect when mixed with gradient separated cells. A helper effect was not produced by this fraction in the presence of Con-A responsive cells. Unlike PHA responses (where optimum binding and proliferation occurred by ADH cells), enrichment for Con-A responders occurred in NA gradient fractions (1.073–1.080 g/ml).
Classical conditioning of attitudes as a function of persuasion trials and source consensus

Conditioned attitude strength was an increasing function of number of persuasion trials and source consensus, and these two variables interacted so that the effects of source consensus became more pronounced as the number of persuasion trials increased. Results were predicted from a theory of persuasive communication in which persuasion trials are analogous to conditioning trials, source consensus is analogous to UCS strength, and probability of agreement is analogous to CR probability.
Uncertainty and sensitivity analysis for models with correlated parameters

When conducting sensitivity and uncertainty analysis, most of the global sensitivity techniques assume parameter independence. However, it is common that the parameters are correlated with each other. For models with correlated inputs, we propose that the contribution of uncertainty to model output by an individual parameter be divided into two parts: the correlated contribution (by the correlated variations, i.e. variations of a parameter which are correlated with other parameters) and the uncorrelated contribution (by the uncorrelated variations, i.e. the unique variations of a parameter which cannot be explained by any other parameters). So far, only a few studies have been conducted to obtain the sensitivity index for a model with correlated input. But these studies do not distinguish between the correlated and uncorrelated contribution of a parameter. In this study, we propose a regression-based method to quantitatively decompose the total uncertainty in model output into partial variances contributed by the correlated variations and partial variances contributed by the uncorrelated variations. The proposed regression-based method is then applied in three test cases. Results show that the regression-based method can successfully measure the uncertainty contribution in the case where the relationship between response and parameters is approximately linear.
The DNA-binding domain of yeast Rap1 interacts with double-stranded DNA in multiple binding modes.

Saccharomyces cerevisiae repressor-activator protein 1 (Rap1) is an essential protein involved in multiple steps of DNA regulation, as an activator in transcription, as a repressor at silencer elements, and as a major component of the shelterin-like complex at telomeres. All the known functions of Rap1 require the known high-affinity and specific interaction of the DNA-binding domain with its recognition sequences. In this work, we focus on the interaction of the DNA-binding domain of Rap1 (Rap1DBD) with double-stranded DNA substrates. Unexpectedly, we found that while Rap1DBD forms a high-affinity 1:1 complex with its DNA recognition site, it can also form lower-affinity complexes with higher stoichiometries on DNA. These lower-affinity interactions are independent of the presence of the recognition sequence, and we propose they originate from the ability of Rap1DBD to bind to DNA in two different binding modes. In one high-affinity binding mode, Rap1DBD likely binds in the conformation observed in the a...
A threshold voltage expression for small-size MOSFET's based on an approximate three-dimensional analysis

A simple threshold voltage expression based on an approximate three-dimensional analysis has been obtained for MOSFET's with the LOCOS isolation structure. It predicts both the short-channel and the narrow-width effects on the threshold voltage of MOSFET's, and the results match the experimental data. In addition, the threshold expression is more general than any other existing models. It includes all the relevant device parameters, such as the drain voltage, the oxide and surface charges, and the fringe field through the oxide sidewalls.
Why holes are not like electrons. II. The role of the electron-ion interaction

In recent work, we discussed the difference between electrons and holes in energy band in solids from a many-particle point of view, originating in the electron-electron interaction, and argued that it has fundamental consequences for superconductivity. Here we discuss the fact that there is also a fundamental difference between electrons and holes already at the single particle level, arising from the electron-ion interaction. The difference between electrons and holes due to this effect parallels the difference due to electron-electron interactions, holes are more dressed than electrons. We propose that superconductivity originates in ``undressing'' of carriers from both electron-electron and electron-ion interactions, and that both aspects of undressing have observable consequences.
The effect of the vaccinia K1 protein on the PKR-eIF2α pathway in RK13 and HeLa cells

Activated PKR protein regulates downstream anti-viral effects, including inhibition of translation. Thus, many viruses encode proteins to inhibit PKR. Here, we provide evidence that the vaccinia virus K1 protein, a host-range protein, possesses this function. First, the expression of the wild-type K1 protein was necessary to inhibit virus-induced eIF2α phosphorylation, an indirect measure of PKR activation, in RK13 and HeLa cells. Second, virus-induced eIF2α phosphorylation no longer occurred in PKR-deficient HeLa cells, suggesting PKR was responsible for vaccinia virus-induced eIF2α modification. Third, in normal HeLa cells, K1 protein expression also prevented virus-mediated PKR phosphorylation (activation). Residues in the C-terminal portion of the ANK2 region of K1 were identified as necessary for this inhibitory phenotype. Interestingly, mutant viruses that failed to inhibit PKR activation, such as S2C#2, also did not replicate in HeLa cells, suggesting that K1's inhibition of PKR was required for a productive infection. In support of this theory, when PKR was absent from HeLa cells, there was a modest restoration of viral protein synthesis during S2C#2 infection. However, the increased protein synthesis was insufficient for a productive infection.
Effects of PCB 126 on Primary Immune Organs and Thymocyte Apoptosis in Chicken Embryos

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyl (PCB) 126 produce thymic atrophy and immunosuppression. This study explored the hypothesis that the thymic atrophy produced by developmental exposure to PCB 126 is associated with an increase in apoptotic thymocytes at the end of incubation in chicken embryos. Eggs were injected via the air cell with PCB 126 (0.05, 0.13, 0.32, 0.64, and 0.80 ng/g egg) on d 0 of incubation, and tissues were collected on d 20. Controls included noninjected and vehicle-injected (sunflower oil) eggs. Thymocytes were cultured for 6 h and analyzed by flow cytometry for decreased DNA content (propidium iodide staining) and cell size (forward scatter), which indicate apoptosis. PCB 126 induced dose-dependent mortality with an LD50 of 1.01 ng/g and lowest-observed-effect concentration (LOEC) of 0.32 ng/g. Teratogenic effects commonly associated with TCDD and planar PCBs, including cranial and foot deformities and subcutaneous edema, tended to increase with dos...
The multiple organ dysfunction syndrome and late-phase mortality in sepsis.

Sepsis is a devastating and common syndrome characterized by systemic inflammation. Sepsis accounts for considerable morbidity and mortality among intensive care unit patients. Although the inflammatory response generated by the immune system represents the body’s attempt to clear invading pathogens, it is the failure to modulate this response that leads to dysregulated inflammation and the injury of healthy tissue. A great deal of research has characterized many of the early events and mediators that lead to systemic inflammation and sepsis. However, substantially less is known about the pathogenesis of the late phase of sepsis, which accounts for the vast majority of sepsisrelated mortality (ie, the dysfunction and subsequent failure of the major parenchymal organs).
Effect of leukocyte-endothelial adhesion antagonism on neutrophil migration and neurologic outcome after cortical trauma.

Background: Administration of anti-CD11B, a monoclonal antibody directed against the leukocyte adhesion molecule CD11B, results in decreased neutrophil infiltration into injured tissue after experimental ischemia. We determined the effect of anti-CD11B administration on neutrophil migration and neurologic functioning after experimental cortical trauma. Methods: Injuries were produced by a pneumatic impactor. Treatment animals received anti-CD11B after injury. Neurologic functioning was quantitated at 1, 12, and 24 hours after injury. Neutrophil migration was assessed with the myeloperoxidase assay. Results: Neutrophil influx was increased in injured cortex after trauma. Anti-CD11B significantly reduced neutrophil influx. There was no significant improvement in neurologic functioning after MAb administration. Conclusions: These results show there is marked neutrophil response to injury as produced with the pneumatic contusion model. This migration may be significantly attenuated by administration of a anti-CD11B.
The Effect of Color on Temperature of Electrical Enclosures Subject to Solar Radiation

Electrical enclosures have historically been painted with dark colors ostensibly to enhance the radiation of internally generated heat. Outdoors, these dark colors are great absorbers of solar radiation, from which the enclosure incurs an appreciable temperature rise. The lighter colors absorb less solar radiation, incurring smaller solar temperature rise. However, it is demonstrated that these lighter colors radiate the lower temperatures of the equipment as well as the darker colors. Hence, equipment painted with the lighter colors will operate at a lower temperature and be subject to less severe derating from the effects of solar radiation.
Definitions of health and illness and medical sociology

Abstract Notions of health and disease in any culture are intimately tied to images of the body, and tend to be largely taken for granted. Contemporary social scientific definitions of health and illness, most of which are more or less derived from Parsons' original work, are also shown to be based on taken for granted Western medical definitions of illness which are specific to modern society and which obviate the possibility of a social scientific investigation of the social influences on subjective perceptions of healthy or ill bodies. Accepting a medical construction of reality has also led social scientists to ignore the whole range of health activities which take place outside of the professional sphere. An alternative approach is explored that is more theoretically and pragmatically adequate and which uses the phenomenological sociology of Alfred Schutz and draws on the work of Douglas, and Manning and Fabrega.
Regional trade pacts and the competitiveness of the US textile industry

The U.S. textile industry has gone through much upheaval in the past two decades. As protective barriers are gradually phased out the industry is faced with stiff foreign competition. Regional trade pacts, such as NAFTA and CBI, on the other hand help to improve the competitiveness of the domestic textile industry. This paper looks at the trends in U.S. textile trade with the various trading zones and the various factors influencing textile imports and exports. We examine the impact of the new global environment, the regional trade pacts, NAFTA and CBI on the changing nature and pattern of trade. The overall trends indicate a significant decline in imports from the EU countries, Asia remains significant, but NAFTA and CBI countries are quickly gaining ground over the old trading partners. The OECD remains the most significant destination for U.S. textile exports followed by NAFTA and Latin American countries.
Social psychological variables in populations contrasted by income and suicide rate: Durkheim revisited

The ten richest and ten poorest municipalities of Sweden were investigated with respect to national statistics to assess the relationship between suicide incidence, discrete social psychological variables associated with welfare admittance among the elderly, and income of municipality. The relative frequency of suicide was 1.6 times greater for Swedes from the low-income municipalities than for those from the high-income ones. The group of municipalities with the highest suicide rate had a significantly higher proportion of older people in need of municipal social assistance at their homes and also a significantly higher proportion of elderly living in municipality-managed 'service-homes.' The findings replicate earlier investigations and suggest social psychological indicators denoting less favourable economic and social resources are also associated with both an increased suicide rate and a decreased county or municipal income. Some theoretical issues of the socioeconomic and of the external restraint hypotheses of the incidence of suicide, contradicted by the present findings as well as of Durkheim's hypothesis of social control are discussed. Further, we suggest the consideration of negative socioeconomic conditions as a risk factor amid psychiatric clinical assessments of risk for suicidal behaviour.
Send the fossils to me in Philadelphia: Support for early Kansas paleontology by United States Geological Survey of the Territories

Abstract The United States Geological Survey of the Territories published several landmark works of paleontology that dealt with fossils found in Kansas during the decade after the Civil War. Such works appeared as volumes of the Hayden and King Surveys. There were also lesser known USGS publications on Kansas paleontology that preceded these important works. Cope's Vertebrata of the Cretaceous Formations of the West (1875) and Marsh's Odontornithes (1880). This study concerns the contents of USGS publications concerning paleontology in Kansas to 1875, as well also the role that the USGS publications play today in the study of the history of paleontology in the state as that support is recorded in the publications. “By examining the publications of the survey, it will be seen that much attention has been given to the ancient fauna and flora of our Western Territories. The value of [the] studies in connection with geological explorations and surveys is often in danger of being underestimated by not being c...
Parameter estimation for the thurstone case III model

A Monte Carlo study was conducted to investigate the ability of three estimation criteria to recover the parameters of Case V and Case III models from comparative judgment data. Significant differences in recovery are shown to exist.
The impact of managed care insurance on use of lower-mortality hospitals by children undergoing cardiac surgery in California.

Context. Managed care plans aggressively seek to contain costs, but few data are available regarding their impact on access to high quality care for their members. Objective. To assess the impact of managed care health insurance on use of lower-mortality hospitals for children undergoing heart surgery in California. Design. Retrospective cohort study using state-mandated hospital discharge datasets. Setting. Pediatric cardiovascular surgical centers in California. Patients. Five thousand seventy-one children admitted for open cardiac surgical procedures during 1992–1994. Results. Hospitals were divided into lower- and higher-mortality groups according to adjusted surgical mortality. Using multivariate logistic regression analysis to control for medical, socioeconomic, demographic, and distance factors, children with managed care insurance were less likely to be admitted to a lower-mortality hospital for surgery relative to children with indemnity insurance (odds ratio: .53; 95% confidence interval: .45,.63). Similar findings resulted when the analysis was stratified by race/ethnicity. In addition, length of stay, a correlate of health care costs, was no longer for children admitted to lower-mortality centers than for those at higher-mortality centers (adjusted difference: .54 days shorter at lower-mortality centers; 95% confidence interval: −1.50,.41). Conclusions. During this study, children with managed care insurance had significantly reduced use of lower-mortality hospitals for pediatric heart surgery in California compared with children with indemnity insurance. Further study is necessary to determine the mechanisms of this apparent insurance-specific inequity.
A Tale of Two Heuristics: Conflicting Work Allocation Approaches in Engineering Consulting

AbstractWork allocation is a critical function in engineering management, with ramifications for an organization's Financial performance, output quality, system throughput and capacity, client service, and worker satisfaction. This is especially true for engineering consulting firms, where work allocation decisions become strategic in nature. This article examines conflicting approaches to work allocation in a typical engineering consulting organization. An analytical framework is proposed to determine whether one approach is superior to the other. In particular, spreadsheet models are used to compare a leveraged approach with a cascaded bin-packing approach; both solutions are contrasted with the case study's de facto approach. Sensitivity analysis is applied to demonstrate the models' robustness. The implications of the models are discussed.
Transfer of anesthetics and alcohols into ionic surfactant micelles in relation to depression of krafft point and critical micelle concentration, and interfacial action of anesthetics

Abstract The Krafft points of sodium dodecyl sulfate (SDS) and sodium tetradecyl sulfate (STS) decreased linearly with the increase of the concentration of added alcohols (1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol). On the basis of a theory which treats the Krafft point as the melting point of the hydrated solid surfactant, the partition coefficients, K , of alcohols between the aqueous and the micellar phases were calculated from the Krafft-point depressions by the aid of thermodynamics. The values of K obtained by the present method were in good agreement with those measured by other methods. The transfer free energies of alcohols from the bulk solution to the SDS and STS micelles, ΔG p o = − RT In K , decreased linearly with the increase of the carbon number of the alcohol. ΔG p o per methylene group was almost the same for both SDS and STS micelles: −2.45 kJ mol −1 for the SDS micelle and −2.51 kJ mol −1 for the STS micelle. However, the values of ΔG p o of the alcohols into the STS micelle were more negative compared with those into the SDS micelle. This means that the more hydrophobic micelles are favored for the transfer of alcohol. The method presented here is generally applicable to determine the micelle/water partition coefficients of solutes which form mixed micelle. The partition coefficients of inhalation anesthetics between the aqueous and SDS micellar phases were methoxyflurane 1320, halothane 1140, and enflurane 990. These values are in the same order of their clinical potencies. The critical micelle concentration (CMC) of SDS was measured by the conductivity method as a function of the added anesthetics. The CMC decreased linearly with the increase of the anesthetic concentration. The decrease of the CMC by anesthetics was correlated to the micelle/water partition coefficient of these anesthetics by means of the relation proposed by Shirahama and Kashiwabara ( J. Colloid Interface Sci. 36 , 65 (1971)) , and was ascribed mainly to the increase in entropy of mixing in the micelle due to the solubilization of the inhalation anesthetics. The decrease of CMC by anesthetics was accompanied by a small but unequivocal release of the counterions from the micellar surfaces which indicates the tendency of anesthetics to dehydrate the interface.
Combined nonstandard numerical methods for ODEs with polynomial right-hand sides

In this paper we formulate conditions that guarantee second-order accuracy of the one-step nonstandard finite difference methods for general first order autonomous ordinary differential equations. We also develop a new class of nonstandard finite-difference methods for differential equations of the form dx/dt = polynomial(x), based on earlier results obtained in reference [H.V. Kojouharov, B.M. Chen, Nonstandard Eulerian-Lagrangian methods for multi-dimensional reactive transport problems, Appl. Numer. Math. 49 (2) (2004) 225-243]. Error analysis and numerical examples that demonstrate the performance of the proposed new method are also provided.
Union of Geometric Constraint-Based Simulations with Molecular Dynamics for Protein Structure Prediction

Although proteins are a fundamental unit in biology, the mechanism by which proteins fold into their native state is not well understood. In this work, we explore the assembly of secondary structure units via geometric constraint-based simulations and the effect of refinement of assembled structures using reservoir replica exchange molecular dynamics. Our approach uses two crucial features of these methods: i), geometric simulations speed up the search for nativelike topologies as there are no energy barriers to overcome; and ii), molecular dynamics identifies the low free energy structures and further refines these structures toward the actual native conformation. We use eight α-, β-, and α/β-proteins to test our method. The geometric simulations of our test set result in an average RMSD from native of 3.7 A and this further reduces to 2.7 A after refinement. We also explore the question of robustness of assembly for inaccurate (shifted and shortened) secondary structure. We find that the RMSD from native is highly dependent on the accuracy of secondary structure input, and even slightly shifting the location of secondary structure along the amino acid sequence can lead to a rapid decrease in RMSD to native due to incorrect packing.
Monitoring soil water and ionic solute distributions using time-domain reflectometry

Abstract Improved ability to measure simultaneously volumetric soil water content ( θ ) and the distribution of ionic solutes would facilitate more intensive and efficient soil management. Time-domain reflectometry (TDR) exhibits a unique ability to measure θ and bulk electrical conductivity ( σ a ) in the same soil volume. Sensors at multiple locations may easily be multiplexed and continuously monitored. Although a number of simple and effective calibrations for θ are available, application of TDR to estimate soil solution conductivity ( σ w ) as an indirect measure of ionic concentration ( C i ) is more problematic, particularly under transient soil wetness conditions. We investigated the potential to monitor continuously soil θ , σ w , and nitrate concentrations in a production peppermint ( Mentha piperita L.) field during April through early August of 1996, using automated TDR. We evaluated two physical-conceptual TDR calibration models for σ w ( θ , σ a ), and compared results to σ w and nitrate concentrations as measured in soil solution extracts and soil cores from the same field area. TDR estimates were generally in reasonable agreement with soil cores, with measured core and TDR values exhibiting substantial variability among replicate samples. Our results suggest that heterogeneity resulting from spatial differences in soil properties, irrigation, fertilizer application, and plant uptake may need to be considered in calibration of TDR.
Microbial Fuel Cells, A Current Review

Microbial fuel cells (MFCs) are devices that can use bacterial metabolism to produce an electrical current from a wide range organic substrates. Due to the promise of sustainable energy production from organic wastes, research has intensified in this field in the last few years. While holding great promise only a few marine sediment MFCs have been used practically, providing current for low power devices. To further improve MFC technology an understanding of the limitations and microbiology of these systems is required. Some researchers are uncovering that the greatest value of MFC technology may not be the production of electricity but the ability of electrode associated microbes to degrade wastes and toxic chemicals. We conclude that for further development of MFC applications, a greater focus on understanding the microbial processes in MFC systems is required.
Do extraverts process social stimuli differently from introverts

The personality trait of extraversion has been linked to the network of brain systems controlling sensitivity to cues of reward and generating approach behavior in response, but little is known about whether extraverts' neural circuits are especially sensitive to social stimuli, given their preference for social engagement. Utilizing event-related potential (ERP) methodology, this study demonstrates that variation on the extraversion dimension is associated with the extent to which social stimuli evoke enhanced allocation of attention. Specifically, higher scores on extraversion were found to be associated with higher amplitudes of the P300 component of the ERPs elicited by human faces. This finding suggests that social stimuli carry enhanced motivational significance for individuals characterized by high extraversion, and that individual differences in personality are related to meaningful individual differences in neural responses to social stimuli.
EFFECTS OF SPECIES DIVERSITY ON COMMUNITY BIOMASS PRODUCTION CHANGE OVER THE COURSE OF SUCCESSION

Over the past decade an increasing number of studies have experimentally manipulated the number of species in a community and examined how this alters the aggregate production of species biomass. Many of these studies have shown that the effects of richness on biomass change through time, but we have limited understanding of the mechanisms that produce these dynamic trends. Here we report the results of an experiment in which we manipulated the richness of freshwater algae in laboratory microcosms. We used two experimental designs (additive and substitutive) that make different assumptions about how patches are initially colonized, and then tracked the development of community biomass from the point of initial colonization through a period of 6-12 generations of the focal species. We found that the effect of initial species richness on biomass production qualitatively shifted twice over the course of the experiment. The first shift occurred as species transitioned from density-independent to dependent phases of population growth. At this time, intraspecific competition caused monocultures to approach their respective carrying capacities more slowly than polycultures. As a consequence, species tended to over-yield for a brief time, generating a positive, but transient effect of diversity on community biomass. The second shift occurred as communities approached carrying capacity. At this time, strong interspecific interactions caused biomass to be dominated by the competitively superior species in polycultures. As this species had the lowest carrying capacity, a negative effect of diversity on biomass resulted in late succession. Although these two shifts produced dynamics that appeared complex, we show that the patterns can be fit to a simple Lotka-Volterra model of competition. Our results suggest that the effects of algal diversity on primary production change in a predictable sequence through successional time.
Evolution of the medium: positioning for the future of gaming

The game industry is changing and maturing; the definitions of what games are, who makes them and who consumes them are constantly shifting and expanding. More than ever, we are seeing an increase in options and more opportunities for graduates looking for professional careers in games and even more avenues for research to explore the gaming medium.
Randomized, Controlled Trial of Written Emotional Expression and Benefit Finding in Breast Cancer Patients

PURPOSE: Expressing emotions and finding benefits regarding stressful experiences have been associated in correlational research with positive adjustment. A randomized trial was performed to compare effects of experimentally induced written emotional disclosure and benefit finding with a control condition on physical and psychological adjustment to breast cancer and to test whether outcomes varied as a function of participants’ cancer-related avoidance. PATIENTS AND METHODS: Early-stage breast cancer patients completing medical treatment were assigned randomly to write over four sessions about (1) their deepest thoughts and feelings regarding breast cancer (EMO group; n = 21), (2) positive thoughts and feelings regarding their experience with breast cancer (POS group; n = 21), or (3) facts of their breast cancer experience (CTL group; n = 18). Psychological (eg, distress) and physical (perceived somatic symptoms and medical appointments for cancer-related morbidities) outcomes were assessed at 1- and 3-mo...
Influence of Elevation, Land Use, and Landscape Context on Patterns of Alien Plant Invasions along Roadsides in Protected Areas of South-Central Chile

Alien plant species are a growing concern in protected areas, yet little information is available on the role of roads as corridors for alien species and the effects of elevation, land use, and landscape context in these invasions. These concerns are of particular interest in temperate zones of South America, where protected areas have high concentrations of endemic species. We studied roadside alien plant communities and forest-road edges in Villarrica and Huerquehue national parks in the Andean portion of south-central Chile. We sampled alien species and their abundance along 21 km of roads inside parks and 22 km outside parks, using 500-m roadside transects. We also sampled plant species and recorded their abundance in 15 transects located perpendicular to forest-road edges in four forest types. Of the 66 alien species encountered along roadsides, 61 were present outside parks and 39 inside parks. Elevation and alien species richness along roadsides were significantly and negatively correlated (R 2 =− 0.56, p < 0.001). Elevation, land use, and their interaction explained 74% of the variation in alien species richness along roadsides (p < 0.001). Transects located in pasture or disturbed secondary forests had significantly more alien species. We found no significant edge effect on native and alien species richness in any forest type. Few alien species have percolated into forest interiors. Native and alien diversity in edge plots were not related. Almost half the alien species belonged to three families and 85% were native to Eurasia. Our results suggest that alien species are moving into parks along road corridors and that elevation and land use of the matrix influence these invasion processes. Our findings corroborate the importance of early detection and control of invasive species in protected areas and highlight the importance of considering surrounding matrix land use in developing conservation strategies for reserves.
Doublecortin is expressed in articular chondrocytes

Articular cartilage and cartilage in the embryonic cartilaginous anlagen and growth plates are both hyaline cartilages. In this study, we found that doublecortin (DCX) was expressed in articular chondrocytes but not in chondrocytes from the cartilaginous anlagen or growth plates. DCX was expressed by the cells in the chondrogenous layers but not intermediate layer of joint interzone. Furthermore, the synovium and cruciate ligaments were DCX-negative. DCX-positive chondrocytes were very rare in tissue engineered cartilage derived from in vitro pellet culture of rat chondrosarcoma, ATDC5, and C3H10T1/2 cells. However, the new hyaline cartilage formed in rabbit knee defect contained mostly DCX-positive chondrocytes. Our results demonstrate that DCX can be used as a marker to distinguish articular chondrocytes from other chondrocytes and to evaluate the quality of tissue engineered or regenerated cartilage in terms of their "articular" or "non-articular" nature.