cssi/SciSciGPT-SciSciNet huggingface dataset:
Significant disparity of non-basal dislocation activities in hot-rolled highly-textured Mg and Mg-3Al-1Zn alloy under tension

Abstract It is well-established that Mg-3Al-1Zn (AZ31) alloy exhibits much better tensile ductility than pure Mg. However, the underlying mechanisms for such difference still remain relatively unexplored at the dislocation level. In this work, we deformed hot-rolled highly-textured pure Mg and AZ31 samples with similar initial microstructures (i.e., grain size and texture) under tension along the rolling direction. Apparent shear banding was only observed in the pure Mg samples from the early stage of the deformation. Shear bands could act as easy paths for crack propagation, leading to low ductility in pure Mg. Apparent shear banding was not noted in deformed AZ31 samples. We then investigated the deformation mechanisms at the dislocation level using transmission electron microscopy. Systematic tilting experiments and statistical analyses of multiple grains at different strain levels revealed a significant disparity of non-basal dislocation activities between pure Mg and AZ31. For pure Mg, dislocations were activated since the early stage of plastic deformation. For AZ31, dislocations were mostly absent at all strain levels, even in the strain-to-failure samples. Non-basal dislocations, including prismatic and pyramidal dislocations, were observed. The promotion of the non-basal dislocation activities and the suppression of dislocations in AZ31 are expected to offer more sustainable hardening, which could elucidate the absence of apparent shear banding and much-improved ductility in AZ31 compared to pure Mg.
Description of Daily Living Skills and Independence: A Cohort from a Multidisciplinary Down Syndrome Clinic.

Levels of independence vary in individuals with Down syndrome (DS). We began this study to describe the current life skills in our clinic population of children and adults with DS. We collected and reviewed demographics, living situation, and life skills from an electronic intake form used in clinic procedures. Descriptive statistics for this cohort study included mean, standard deviation, and frequencies. From 2014–2020, 350 pediatric and 196 adult patients (range 0–62 years) with a first visit to the Massachusetts General Hospital Down Syndrome Program are described. Pediatric patients were most often enrolled in school, and in an inclusion setting. Adult patients were most often participating in a day program, living with family, and wanted to continue living with family in the future. Most (87%) of adults with DS communicated verbally, though fewer could use written communication (17%). Life skills of greatest importance to adolescents and adults with DS included: learning about healthy foods (35%), preparing meals (34%), providing personal information when needed (35%), and describing symptoms to a doctor (35%). Life skills for patients with DS are varied; those associated with a medical appointment, such as sharing symptoms with the doctor, could improve for greater independence.
The Ex Post Distributive Case for

This unpublished draft paper posted here as written in 1998, suggests that in deciding whether to impose compulsory terms in consumer contracts the most important criterion should be whether their ex post distributive consequences are desirable from an ethical/political point of view. It then identifies a subclass of terms that operate analogously to compulsory insurance, including among many others product liability and mortgagor and consumer borrower protections. It models the results of the term for three income classes that differ both in their preferences for protection and in the cost of protecting them. The term generates cross subsidies among them and also withdrawals from the market. These are the ex post distributive stakes in the choice to make the term compulsory. The paper then demonstrates that in some circumstances imposed insurance-like terms plausibly generate significant cross subsidies from the upper and middle to the lower income group. These are stable when transaction costs prevent sellers from pricing to keep the poor separate from the rich and the middle. The focus on ex ante efficiency and on distribution between buyers and sellers has obscured cross subsidies between rich and poor buyers. One result has been the common but incorrect argument that because poor buyers likely value compulsory terms less than the rich, compulsion “hurts the people it is trying to help.” The paper shows that it is precisely because of this difference in valuation that existing compulsory terms can function to redistribute and that new ones may be justified on the same basis.
Variable local basin hydrography and productivity control the uranium isotope paleoredox proxy in anoxic black shales

Abstract Geochemical proxies—such as the isotopic compositions and abundances of redox-sensitive metals, organic biomarkers, and sedimentological indicators—can be used qualitatively and quantitatively to reconstruct marine redox landscapes through Earth history. Isotopic proxies with residence times longer than ocean mixing times, including uranium (238U/235U, commonly denoted as δ238U), are a promising but still developing approach to constrain global changes in redox conditions. Our current understanding of the controls on δ238U variability and associated isotopic fractionations is limited, complicating the interpretation of δ238U records through Earth history. With these gaps in mind, we investigate the major controls on the expression of uranium (U) isotope fractionation within two basins of the Miocene Monterey Formation (ca. 18–6 Ma) that represent contemporaneous deposition under different environmental conditions. Our finding that the isotopic offset in the productive and anoxic Santa Barbara Basin is similar to that in modern euxinic settings suggests that highly productive settings without persistent euxinia can also exert significant leverage on seawater δ238U. Distinct patterns in U concentrations and δ238U between basins demonstrate that local depositional controls can impart a strong influence on the U isotope offset in reducing settings, as has been observed in modern sediment datasets. High productivity and low sedimentation rates are predicted to result in a diagnostic inverse relationship between U enrichment and δ238U, which can partially explain the overall weak negative correlation between [U] and δ238U in the distal Naples Beach section in the Santa Barbara Basin. In a core from a more restricted proximal setting in the San Joaquin Basin, we propose that changes in basin hydrography led to a potential relationship between [U] and δ238U. These interpretations are consistent with the characteristic depositional conditions interpreted independently for each basin (e.g., persistence of anoxia, productivity, sedimentation rates, phosphate content, and basin hydrography) and are supported by modeling results of U enrichment and isotope fractionation under these conditions. In particular, our results suggest that the isotope offset of U in reducing sinks varies and has done so over Earth history and in different paleogeographic locations as a result of local productivity and basin restriction. These variations indicate the need to consider these uncertainties in quantitative models of global redox conditions from δ238U records—and specifically in using δ238U to distinguish between euxinic and oxic redox states without considering other oxygen-depleted environments as part of a continuum of settings that can impact δ238U if spatially widespread. This study also highlights the utility of using different lithologies to evaluate global versus local controls on δ238U records as well as multi-proxy approaches to constrain ancient redox landscapes.
Self-Organization at the Frictional Interface

Despite the fact that self-organization during friction has received relatively little attention of the tribologists so far, it has a potential for the creation of self-healing and self-lubricating materials, which are of importance for the green or environment-friendly tribology. The principles of the thermodynamics of irreversible processes and of the nonlinear theory of dynamical systems are used to investigate the formation of spatial and temporal structures during friction. The transition to the self-organized state with low friction and wear occurs through the destabilization of the steady-state (stationary) sliding. The criterion for the destabilization is discussed and examples like formation of a protective film and slip waves are discussed. Some cases like running-in stage, elastic structures, and Turing pattern formation as evidences of self-organization are studied. A special self-healing mechanism may be embedded into material by coupling corresponding required forces. The analysis provides a structure–property relationship which can be applied for the design optimization of composite self-lubricating and self-healing materials for various ecologically friendly applications and green tribology.
The University of Michigan IVHS education program

Rapidly increasing demand for transportation combined with limited ability for expansion of facilities has led to recent degradations in the quality of transportation systems. Intelligent Vehicle-Highway Systems (IVHS) represent a promising effort toward enabling more effective and efficient use of current capacity thus in essence expanding the roadway. As the concepts and technologies utilized by IVHS are new to much of the transportation community there is a need for an educational initiative in this area. In 1990 the University of Michigan (UM) responded to this need by creating the first, and to date the only, university program in IVHS education. The IVHS Education Program is receiving initial multi-year support from the U.S. Department of Transportation with matching support from the University of Michigan. Significant assistance is also being provided by sponsors from industry, the Michigan Department of Transportation, Michigan State University (MSU), and Wayne State University (WSU). The Program is structured as a cross-disciplinary cooperative effort to provide both traditional university and continuing education. Key new initiatives include; 1) a Certificate in Transportation Studies: IVHS which has been designed to complement the depth gained through a master's or Ph.D degree in an established discipline by providing breadth in practical knowledge relevant to IVHS, 2) an Engineering Summer Conference which is offered to expose practicing engineers and professionals to the latest developments in IVHS, and 3) an Executive Education Seminar which is held for corporate and government executives and planners interested in strategic issues in IVHS. The unconventional nature of the IVHS Education Program gave rise to a number of unique difficulties during development and implementation in a traditional university setting. It is hoped that the UM experience in overcoming these hindrances will prove beneficial to any institution seeking to provide similar education.
Evaluating employee assistance programs: A review of methods, outcomes, and future directions

Renewed interest in assisting troubled employees has led to an upsurge in the development of employee assistance programs, coupled with demands for demonstrable effectiveness. This review examines the nature and scope of these programs, their administrative and methodological context, and the types and outcomes of evaluation studies conducted thus far. Proposals for improving future investigations through a number of different approaches and strategies are then made.
A CCAAT/Enhancer-binding Protein Site within Antioxidant/Electrophile Response Element Along with CREB-binding Protein Participate in the Negative Regulation of RatGST-Ya Gene in Vascular Smooth Muscle Cells

Studies were conducted to evaluate the negative regulatory function of rat (r)GST-Yaantioxidant/electrophile response element (ARE/EpRE) in vascular smooth muscle cells (vSMCs). We report that CCAAT/enhancer-binding protein (C/EBP)-β interacts with ARE/EpRE in the rGST-Ya promoter and that aryl hydrocarbon receptor (AhR) is present within the protein complex binding to the C/EBP site. Overexpression of C/EBP-β or C/EBP-α repressed, whereas AhR enhanced, 1.6CAT reporter activity in cells treated with benzo(a)pyrene (BaP). Overexpression of CREB-binding protein (CBP) nullified repression of rGST-Yatranscription. Human adenovirus E1A protein abrogated cotransactivation by CBP but an E1A mutant did not. Overexpression of C/EBPs abrogated stimulation of 1.6CAT by CBP or AhR alone, or in combination, regardless of BaP treatment. Similar profiles were observed using an AhRECAT construct. The C/EBP site within the ARE/EpRE inhibited chemical inducibility of the AhRE. The pattern of mouse GST-Ya regulation by BaP was similar to that of rGST-Ya. We conclude that multiple mechanisms mediate negative regulation ofGST-Ya gene in vSMCs, most significant of which are that C/EBP-β inhibits AhRE or ARE/EpRE inducibility of GST-Ya, limiting CBP levels compromise gene induction, functional interference exists between AhRE and ARE/EpRE, and AhR alone, or in combination with C/EBP-β, functions as a repressor of the ARE/EpRE.
Morals and Primordials

In this essay, Louis M. Guenin argues that an epidosembryo, defined as an unenabled human embryo donated under specified conditions, is a permissible subject of research. This argument provides a more compelling defense of embryonic stem cell research than that afforded by utilitarianism. When fully explicated, Kant9s morality and Catholicism also support epidosembryo research. This breadth of moral support cuts the props from beneath any governmental prohibition. The essay concludes by identifying restraints on research that would impose inefficiencies at no moral gain.
Three-dimensional orientation measurements of symmetric single chromophores using polarization microscopy

A complete understanding of any complex molecular system generally requires a knowledge of the three-dimensional (3D) orientation of its components relative both to each other, and to directional perturbations such as interfaces and electromagnetic fields. Far-field polarization microscopy is a convenient and widespread technique for detecting and measuring the orientation of single chromophores. But because the polarized electromagnetic field that is used to probe the system lacks a significant longitudinal component, it was thought that, in general, only 2D orientation information could be obtained1,2,3. Here we demonstrate that far-field polarization microscopy can yield the 3D orientation of certain highly symmetric single chromophores (CdSe nanocrystal quantum dots in the present case). The key requirement is that the chromophores must have a degenerate transition dipole oriented isotropically in two dimensions, which gives rise to a perpendicular ‘dark axis’ that does not couple to the light field. By measuring the fluorescence intensity from the dipole as a function of polarization angle, it is possible to calculate both the tilt angle between the dark axis and the sample plane, as well as the in-plane orientation, and hence obtain the 3D orientation of the chromophore
Abstract 49: Deletion of Mirna 17-92 in Cerebral Endothelial Cells Induces Disruption of BBB

Background: The MicroRNA 17-92 (miR17-92) cluster regulates endothelial homeostasis. However, the effect of the miR17-92 cluster in cerebral endothelial cells on blood brain barrier (BBB) has not been investigated. We examined BBB integrity in a transgenic mouse line in which miR17-92 cluster is ablated in endothelial cells. Methods and Results: Adult Tie2-Cre:miR17-92 flox/flox (Tie2/miR17-92) mice and Tie2-Cre:Tomato (Tie2/red) reporter mice were used. Cerebral vessels in Tie2/red reporter mice exhibited red fluorescence, indicating specific expression of Tie2 in cerebral endothelial cells. RT-PCR analysis revealed ~70% reduction of miRNA levels of individual members of the miR17-92 cluster in endothelial cells harvested from Tie2/miR17-92 mouse brain, confirming deletion of the miR17-92 cluster. Time-lapse microscopic analysis of cultured endothelial cells showed a substantial reduction of capillary formation by miR17-92 cluster knockout endothelial cells compared to the cells harvested from Tie2/red r...
Host-race formation in a leaf-mining moth

Larvae of the leaf-mining moth, Phyllonorycter salicifoliella Chambers (Lepidoptera: Gracillariidae) feed within leaves of three Populus species in Itasca State Park, north-central Minnesota, USA. Since 1985, leaf-miner densities have been consistently high on Populus tremuloides Michx, intermediate on P. balsamifera L., and low on P. grandidentata Michx. Despite this pattern, a previous study found no difference in egg to adult survivorship among miners on the three hosts, although larval growth rate and pupal mass did vary among hosts (Auerbach & Alberts, 1992).
Evidence that Candida stellatoidea type II is a mutant of Candida albicans that does not express sucrose-inhibitable alpha-glucosidase

Candida stellatoidea is classically distinguished from C. albicans by the ability of the latter species to assimilate sucrose. We show here that sucrose-positive revertants of C. stellatoidea type II are readily isolated and that C. stellatoidea type II strains probably resulted from a mutation in the sucrase gene of C. albicans. The revertants were not laboratory contaminants, as determined by restriction fragment length polymorphism analysis and retention of an auxotrophic marker. The reversion of three tested strains was accompanied by 16 to 110-fold increases in expression of a sucrase/alpha-glucosidase but not an invertase, with a Km for sucrose of about 1 mM. The enzyme activity was assayable in intact cells. The drastically increased expression of such an enzyme would allow extracellular sucrose hydrolysis and assimilation of the monosaccharide products.
Dynamic mechanical properties of a gel of cellulose nitrate in diethyl phthalate: Reduced variable analysis in terms of amorphous and crystalline phases

A phenomenological theory is presented to extend the method of reduced variables for the effects of both temperature and changing degree of crystallinity on the linear viscoelastic properties of solutions of crystalline polymers. The vertical and the horizontal shift factors, which are both obtainable in the course of analysis of the experimental data, are correlated with the concentration of the solution and the volume fraction of the crystalline phase, and the fractional free volume of the system, respectively. Dynamic mechanical properties of a gel of cellulose nitrate (nitrogen content, 12.6%) in diethyl phthalate with a nominal concentration of 18% by weight were obtained in the transition region from glasslike to rubberlike consistency and also in the rubbery plateau region by employing the Fitzgerald apparatus and a freely oscillating torsion pendulum over the temperature range from −49 to 65°C. Application of the new reduction method to the experimental data was found to be quite successful, and it was shown that in general the degree of crystallinity in the system (and hence also the concentration of polymer in the amorphous phase) can depend on both temperature and thermal history. The dynamic mechanical data of a gel of different nominal concentration (23% by weight) previously obtained by Plazek were reanalyzed in terms of the method herein given.
Determining the Number of Latent Classes in Single- and Multiphase Growth Mixture Models

Stage-sequential (or multiphase) growth mixture models are useful for delineating potentially different growth processes across multiple phases over time and for determining whether latent subgroups exist within a population. These models are increasingly important as social behavioral scientists are interested in better understanding change processes across distinctively different phases, such as before and after an intervention. One of the less understood issues related to the use of growth mixture models is how to decide on the optimal number of latent classes. The performance of several traditionally used information criteria for determining the number of classes is examined through a Monte Carlo simulation study in single- and multi-phase growth mixture models. For thorough examination, the simulation was carried out in two perspectives: the models and the factors. The simulation in terms of the models was carried out to see the overall performance of the information criteria within and across the models, while the simulation in terms of the factors was carried out to see the effect of each simulation factor on the performance of the information criteria holding the other factors constant. The findings not only support that sample size adjusted BIC (ADBIC) would be a good choice under more realistic conditions, such as low class separation, smaller sample size, and/or missing data, but also increase understanding of the performance of information criteria in single- and multi-phase growth mixture models.
Experimental measurement of a time-varying optical path difference using the small-aperture beam technique

This paper discusses the use of time series of the jitter angle of multiple, small-aperture probe beams as they emerge from a turbulent, optically-active flow field to quantify the time-varying optical path difference (OPD). Techniques to reconstruct a complete time series of instantaneous realizations of the OPD are first applied to a numerically-generated flow field and then to an experimental flow field. The flow field studied was that for the transitionally- turbulent region of a heated, two-dimensional jet. From these OPD histories spatial and temporal frequencies characterizing the OPD's are extracted. The relevance of these results to adaptive-optic devices is discussed.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Decreased b-lymphocyte response after exposure to lead and cadmium.

Swiss Webster mice were exposed to lead acetate or cadmium chloride in the drinking water for 10 weeks. The ability of bone marrow-derived lymphocytes (B cells) to form rosettes was measured using an erythrocyte-antibody-complement (EAC) assay. Fewer EAC rosettes were formed by splenic B lymphocytes from mice exposed to lead and cadmium than by B cells from control animals. The direct effect of these compounds on B cells could account in part for suppression of the humoral immune response reported in previous studies.
Approach to the management of complex hepatic injuries.

Background: Complex hepatic injuries American Association for the Surgery of Trauma Organ Injury Scale grades IV and V incur high mortality rate ranging from 40 to 80%, respectively. The objective of this study is to assess the clinical experience with an aggressive approach to the management of these, the most complex of hepatic injuries. Methods: This is a retrospective 6-year study (1992-1997) at an American College of Surgeons urban Level I trauma center of patients sustaining complex hepatic injuries whose interventions included surgery, angiographic embolization, endoscopic retrograde cholangiopancreatography plus biliary stenting and percutaneous computed tomographic-guided drainage. The main outcome measure was survival. Results: A total of 22 patients sustaining complex hepatic injuries; mean age of 26 years (range, 10-52 years), mean Revised Trauma Scale score of 9.9, mean Injury Severity Score of 32 (range, 16-75), American Association for the Surgery of Trauma - Organ Injury Scale grade IV (13 cases); grade V (9 cases). Mean estimated blood loss was 4,600 mL; mean number of units of blood transfused was 15. The patients underwent the following interventions: surgery (n = 22), re-operated (n = 13), mean number of operations 1.6 (range, 1-4), extensive hepatotomy and hepatorrhaphy (n = 17), nonanatomic resection (n = 7), formal hepatectomy (n = 4), packing (n = 10), direct approach to hepatic veins (n = 3); angiographic embolization (n = 15); endoscopic retrograde cholangiopancreatography and stenting (n = 5); computed tomographic guided drainage (n = 6). Mean length of stay in the intensive care unit was 21 days (range, 2-134 days), mean hospital length of stay was 40 days (range, 2-147 days). Overall mortality rate was 14% (3 of 22 cases), hepatic mortality rate was 9% (2 of 22 cases), mortality rate by injury grade was 8% grade IV (1 of 13 cases) and 22% grade V (2 of 9 cases). Conclusion: In this select patient population, improvements in mortality rates can be achieved with an aggressive approach to the management of complex hepatic injuries, including surgery, early packing, angiographic embolization, endoscopic retrograde cholangiopancreatography and stenting of biliary leaks, and drainage of hepatic abscesses.
A non-Newtonian model of flow in a kneading disc region of a modular intermeshing corotating twin screw extruder

Abstract The flow of a non-Newtonian fluid in the kneading disc region of an intermeshing co-rotating twin screw extruder has been analyzed using hydrodynamic lubrication theory based on a power law shear viscosity model. The Tadmor et al. FAN method is used as a numerical solution method. Three different approximation methods for introducing power law behavior into the FAN method are described. These were subsequently used to calculate velocity and pressure fields in the kneading disc region. The effects of machine throughput and tip clearance as well as power law index on the flow field were determined. The computation results for the different methods are compared.
Capecitabine/Taxane Combination Therapy: Evolving Clinical Utility in Breast Cancer

Capecitabine is approved as a single agent and in combination with docetaxel for the treatment of metastatic breast cancer. Preclinical and clinical research suggests that the activity of capecitabine is enhanced in combination with taxanes, and several biochemical mechanisms of synergy have been described. Recent data suggest that novel doses and schedules of capecitabine can improve safety without compromising efficacy. More than 50 publications and abstracts describing capecitabine/taxane combination therapy studies were reviewed to evaluate the available data on efficacy, safety, and quality of life for patients with breast cancer. Several ongoing randomized adjuvant and neoadjuvant clinical trials are assessing the clinical utility of capecitabine/taxane combinations in early-stage and locally advanced breast cancer.
Dependence of photoabsorption spectra on long-range fields

Strongly energy-dependent photoabsorption cross sections near excitation thresholds have been parametrized in terms of separate short- and long-range field contributions. The largest portion of this energy dependence results from standard parameters characterizing the long-range field effects; these parameters are known analytically for the most common outer fields, and can be calculated for others independently of the complicated short-range dynamics. The approach is illustrated in the Appendix by using a semiempirical fit to the total H/sup -/ photodetachment cross section to predict partial cross sections.
Low energy collision induced dissociation: phase-shifting excitation control of ion kinetic energy in ion cyclotron resonance spectrometry

Abstract A new method of effecting collision induced dissociation (CID) of molecular ions for use in conjunction with Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry is reported. Using an electronic circuit external to the ICR hardware and software, ions are continuously accelerated and decelerated for hundreds of milliseconds by repeatedly shifting the phase of the radiofrequency excitation driving signal by 180°. At low kinetic energies, a succession of collisions which transfer small amounts of energy favors the lowest energy fragmentation pathway and allows ions with large activation energies to fragment at internal energies within a few kilocalories per mole of threshold. This is demonstrated by the sole production of m/z 92 in the fragmentation of n -butylbenzene cation and by abnormally large secondary isotope effects in the dissociation of tert -butoxide- d 6 anion.
Path to Prosperity: The Dynamics of Freedom and Economic Development

We present a dynamic general equilibrium model that formalizes the political mechanisms that prompt demographic change and augment economic development. We demonstrate that in addition to well-esta...
Group Size Predicts Social but Not Nonsocial Cognition in Lemurs.

The social intelligence hypothesis suggests that living in large social networks was the primary selective pressure for the evolution of complex cognition in primates. This hypothesis is supported by comparative studies demonstrating a positive relationship between social group size and relative brain size across primates. However, the relationship between brain size and cognition remains equivocal. Moreover, there have been no experimental studies directly testing the association between group size and cognition across primates. We tested the social intelligence hypothesis by comparing 6 primate species (total N = 96) characterized by different group sizes on two cognitive tasks. Here, we show that a species’ typical social group size predicts performance on cognitive measures of social cognition, but not a nonsocial measure of inhibitory control. We also show that a species’ mean brain size (in absolute or relative terms) does not predict performance on either task in these species. These data provide evidence for a relationship between group size and social cognition in primates, and reveal the potential for cognitive evolution without concomitant changes in brain size. Furthermore our results underscore the need for more empirical studies of animal cognition, which have the power to reveal species differences in cognition not detectable by proxy variables, such as brain size.
Are we ready for genome-scale modeling in plants?

Abstract As it is becoming easier and faster to generate various types of high-throughput data, one would expect that by now we should have a comprehensive systems-level understanding of biology, biochemistry, and physiology at least in major prokaryotic and eukaryotic model systems. Despite the wealth of available data, we only get a glimpse of what is going on at the molecular level from the global perspective. The major reason is the high level of cellular complexity and our limited ability to identify all (or at least important) components and their interactions in virtually infinite number of internal and external conditions. Metabolism can be modeled mathematically by the use of ge nome-scale m odels (GEMs). GEMs are in silico metabolic flux models derived from available genome annotation. These models predict the combination of flux values of a defined metabolic network given the influence of internal and external signals. GEMs have been successfully implemented to model bacterial metabolism for over a decade. However, it was not until 2009 when the first GEM for Arabidopsis thaliana cell-suspension cultures was generated. Genome-scale modeling (“GEMing”) in plants brings new challenges primarily due to the missing components and complexity of plant cells represented by the existence of: (i) photosynthesis; (ii) compartmentation; (iii) variety of cell and tissue types; and (iv) diverse metabolic responses to environmental and developmental cues as well as pathogens, insects, and competing weeds. This review presents a critical discussion of the advantages of existing plant GEMs, while identifies key targets for future improvements. Plant GEMs tend to be accurate in predicting qualitative changes in selected aspects of central carbon metabolism, while secondary metabolism is largely neglected mainly due to the missing (unknown) genes and metabolites. As such, these models are suitable for exploring metabolism in plants grown in favorable conditions, but not in field-grown plants that have to cope with environmental changes in complex ecosystems. AraGEM is the first GEM describing a photosynthetic and photorespiring plant cell ( Arabidopsis thaliana ). We demonstrate the use of AraGEM given the current (limited) knowledge of plant metabolism and reveal the unexpected robustness of AraGEM by a series of in silico simulations. The major focus of these simulations is on the assessment of the: (i) network connectivity; (ii) influence of CO 2 and photon uptake rates on cellular growth rates and production of individual biomass components; and (iii) stability of plant central carbon metabolism with internal pH changes.
Effect of surface treatments and cyclic loading on the bond strength of acrylic resin denture teeth with autopolymerized repair acrylic resin.

Statement of problem Fracture of denture teeth from the denture base is a common problem associated with dental prostheses. Fractured tooth surfaces treated with chemical agents and mechanical features have the potential for improved repair strength. Purpose The purpose of this study was to compare bond strengths of denture teeth to autopolymerized repair acrylic resin after various surface treatments, before and after cyclic loading. Material and methods Mandibular lateral incisor denture teeth were selected and ground on the ridge-lap portion using a standardized jig. Specimens with a ground surface were used as controls. The experimental groups included: ground plus airborne-particle abraded, ground plus diatoric recess, and ground plus an experimental bonding agent. The teeth were affixed by an autopolymerized repair acrylic resin to denture bases. Specimens (n=10) were subjected to compression testing (5 mm/min) at a 135-degree angle, before and after 14,400 loading cycles at 2 Hz and 22 N. Peak load to dislodgement was recorded and statistically analyzed (2-way ANOVA, Tukey HSD, α=.05). The specimens were then examined using x10 magnification, and fractures were categorized as adhesive, cohesive, or mixed. Results The mean bond strengths ranged from 26.3 N to 44.2 N. There were no significant differences in fatigue versus nonfatigue strength values within each group ( P =.244). Significant strength differences were found ( P Conclusions The use of a bonding agent and the placement of a diatoric recess in the denture tooth resulted in higher bond strengths than grinding alone. Cyclic loading had no significant impact on the bond strength of denture teeth to the autopolymerized repair acrylic resin. (J Prosthet Dent 2010;103:245-252)
Subunit structure of rabbit muscle aldolase: Extent of homology of the α and β subunits and age-dependent changes in their ratio

Abstract The α and β subunits of rabbit muscle aldolase, dissociated in 8 m urea and separated by chromatography on DEAE-cellulose, were cleaved with cyanogen bromide. The corresponding cyanogen bromide peptides from the two subunits were found to be very similar in amino acid composition and in tryptic fingerprints, possibly differing in only a single peptide. In aldolase prepared from skeletal muscle of young rabbits the α subunit predominates, in contrast to preparations from adult rabbits which contain nearly equal quantities of the α and β subunits. The change in ratio occurs between 3 and 5 months of age. These results suggest that the two subunits have a common genetic origin, and that the β subunit may arise by a modification of one or more amino acids near the COOH-terminus of the molecule.
The C-terminal Kinase and ERK-binding Domains of Drosophila S6KII (RSK) Are Required for Phosphorylation of the Protein and Modulation of Circadian Behavior

A detailed structure/function analysis of Drosophila p90 ribosomal S6 kinase (S6KII) or its mammalian homolog RSK has not been performed in the context of neuronal plasticity or behavior. We previously reported that S6KII is required for normal circadian periodicity. Here we report a site-directed mutagenesis of S6KII and analysis of mutants, in vivo, that identifies functional domains and phosphorylation sites critical for the regulation of circadian period. We demonstrate, for the first time, a role for the S6KII C-terminal kinase that is independent of its known role in activation of the N-terminal kinase. Both S6KII C-terminal kinase activity and its ERK-binding domain are required for wild-type circadian period and normal phosphorylation status of the protein. In contrast, the N-terminal kinase of S6KII is dispensable for modulation of circadian period and normal phosphorylation of the protein. We also show that particular sites of S6KII phosphorylation, Ser-515 and Thr-732, are essential for normal circadian behavior. Surprisingly, the phosphorylation of S6KII residues, in vivo, does not follow a strict sequential pattern, as implied by certain cell-based studies of mammalian RSK protein.
Gallium(III) does not actively substitute for iron(III) in iron/gallium competition studies

Abstract Strategy II plants respond to Fe stress by releasing a phytosiderophore and are believed to absorb Fe as Fe(III). Gallium(III) has chemical characteristics which have made it useful as a substitute for Fe(III) in biological systems. The objectives of our study were to: 1) determine if Ga(III) acts competitively to reduce Fe(III) uptake or otherwise substitutes for Fe(III) in barley (Hordeum vulgare L.), and 2) determine if the competition for Fe(III) between EDDHA or BPDS and barley further elucidates the form of Fe absorbed by barley. Chlorosis ratings, phytosiderophore production, and tissue Fe contents were indexes of Fe stress. Gallium was absorbed and translocated by the plant both in the presence and absence of Fe, and slightly alleviated Fe stress in the absence of Fe. However, Fe uptake was not affected by the presence of Ga. Thus, Ga(III) did not seem to compete with Fe(III) for uptake. Increasing EDDHA in solution intensified chlorosis and phytosiderophore production and reduced root Fe...
Selective inhibition of human immunodeficiency viruses by racemates and enantiomers of cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine.

2',3'-Dideoxy-5-fluoro-3'-thiacytidine (FTC) has been shown to be a potent and selective compound against human immunodeficiency virus type 1 in acutely infected primary human lymphocytes. FTC is also active against human immunodeficiency virus type 2, simian immunodeficiency virus, and feline immunodeficiency virus in various cell culture systems, including human monocytes. The antiviral activity can be prevented by 2'-deoxycytidine, but not by other natural nucleosides, suggesting that FTC must be phosphorylated to be active and 2'-deoxycytidine kinase is responsible for the phosphorylation. By using chiral columns or enzymatic techniques, the two enantiomers of FTC were separated. The (-)-beta-enantiomer of FTC was about 20-fold more potent than the (+)-beta-enantiomer against human immunodeficiency virus type 1 in peripheral blood mononuclear cells and was also effective in thymidine kinase-deficient CEM cells. Racemic FTC and its enantiomers were nontoxic to human lymphocytes and other cell lines at concentrations of up to 100 microM. Studies with human bone marrow cells indicated that racemic FTC and its (-)-enantiomer had a median inhibitory concentration of > 30 microM. The (+)-enantiomer was significantly more toxic than the (-)-enantiomer to myeloid progenitor cells. The susceptibilities to FTC of pretherapy isolates in comparison with those of posttherapy 3'-azido-3'-deoxythymidine-resistant viruses in human lymphocytes were not substantially different. Similar results were obtained with well-defined 2',3'-dideoxyinosine- and nevirapine-resistant viruses. (-)-FTC-5'-triphosphate competitively inhibited human immunodeficiency virus type 1 reverse transcriptase, with an inhibition constant of 2.9 microM, when a poly(I)n.oligo(dC)19-24 template primer was used. These results suggest that further development of the (-)-Beta-enantiomer of FTC is warranted as an antiviral agent for infections caused by human immunodeficiency viruses.
An Open-Bisimilarity Based Automated Verification Tool for -Calculus Family of Process Calculi

The complexity of designing concurrent and highly-evolving interactive systems has grown to a point where system verification has become a hurdle. Fortunately, formal verification methods have arrived at the right time. They detect errors, inconsistencies and incompleteness at early development stages of a system formally modeled using a formal specification language. -calculus Milner, 1999 is one such formal language which provides strong mathematical base that can be used for verifying system specifications. But manually verifying the specifications of concurrent systems is a very tedious and error-prone work, especially if the specifications are large. Consequently, an automated verification tool would be essential for efficient system design and development. In addition, formal verification tools are vital ingredient to fully harness the potential of component-based software composition. The authors developed such an automated verification tool which is highly portable and seamlessly integrates with the visualization, reduction and performance evaluation tools introduced Ahmad & Rahimi, 2008; Rahimi, 2006; Rahimi et al., 2001, 2008 to provide a comprehensive tool for designing and analyzing multi process/agent systems. Open-Bisimulation Sangiorgi, 1996 concept is utilized as the theoretical base for the design and implementation of the tool which incorporates an expert system implemented in Java Expert System Shell JESS Friedman-Hill, 2003.
SPECKLE IMAGING WITH THE MULTI-ANODE MICROCHANNEL ARRAY DETECTOR

This dissertation combines and instrument and a technique that have been studied separately for several years. The instrument is the multi-anode microchannel array (MAMA) detector. This device is a photon-counting imaging system that has been developed primarily for use in ultraviolet astrophysics. Current generation MAMA detectors have the ability to record the arrival time of every detected photon and can distinguish events which arrive only 140 nanoseconds apart in time. The technique is speckle imaging. This is an interferometric method of recovering high-resolution information about astronomical objects from ground-based telescopes, usually carried out in visible or infrared wavelengths. In conventional astronomy, fluctuations in the atmosphere above the telescope blur images so that the resolution is typically 1 to 2 arcseconds, much worse than the theoretical diffraction-limited resolution of large telescopes. Speckle imaging allows for the reconstruction of image features on a much smaller scale by taking many short (typically 0.01 second) exposure images of an object, where over the exposure time the atmospheric fluctuations are effectively frozen. Speckle imaging devices must therefore have the ability to read out images much faster than most other astronomical imaging devices. Since the MAMA detector offers outstanding timing abilities as well as good spatial linearity and is available in a visible light version, it is an excellent choice as the imaging device in a speckle imaging system. A new speckle system based on the MAMA detector has been built at Stanford University and a detailed study of the performance of the system forms a principle part of this work. Under certain observational conditions, the phenonomenon of channel saturation of the MAMA detector can significantly affect the signal-to-noise ratio of the speckle imaging results. In addition, channel saturation leads to a systematic error in the determination of the irradiance ratios (or equivalently, the magnitude differences) of interferometric binary stars. A correction algorithm is described which leads to better estimates of these ratios in simulated data. Four methods of computing the correlation functions necessary for producing high-resolution reconstructed images are compared using MAMA data. Two of these methods explicitly make use of the time-tagging ability of the MAMA detector and have not been previously studied in detail. The highest signal-to-noise ratio in the power spectrum and bispectrum is obtained with a weighted running-window method. Reconstructed images of several objects are presented. The MAMA-based speckle imaging system is shown to determine accurate position angles and separations of sub-arcsecond separation binary stars.
The formation of diethyl ether via the reaction of iodoethane with atomic oxygen on the Ag(110) surface

Abstract The reactions of iodoethane (ICH 2 CH 3 ) on clean and oxygen-covered Ag(110) surfaces were investigated using temperature-programmed desorption (TPD) and high-resolution electron energy-loss spectroscopy (HREELS). Iodoethane adsorbs dissociatively at 150 K to produce surface ethyl groups on both clean and oxygen-covered Ag(110) surfaces. The ethyl species couple to form butane on both surfaces, with the desorption peak maximum located between 218 and 238 K, depending on the ethyl coverage. In addition to butane, a number of oxidation products including diethyl ether, ethanol, acetaldehyde, surface acetate, ethylene, carbon dioxide and water were formed on the oxygen-dosed Ag(110) surface. Diethyl ether was the major oxygenate produced at all ethyl:oxygen ratios, and the peak temperature for ether evolution varied from 220 to 266 K depending on the relative coverages of these reactants. The total combustion products, CO 2 and H 2 O, were primarily formed at low ethyl coverages in the presence of excess oxygen. The formation of ethylene near 240 K probably involves an oxygen-assisted dehydrogenation pathway since ethylene is not formed from ethyl groups on the clean surface. Acetaldehyde and ethanol evolve coincidentally with a peak centered at 270–280 K, and are attributed to the reactions of surface ethoxide species. The surface acetate which decomposes near 620 K is formed from subsequent reactions of acetaldehyde with oxygen atoms. The addition of ethyl to oxygen to form surface ethoxides was verified by HREELS results. The yields of all products exhibited a strong dependence on the relative coverages of ethyl and oxygen.
Calculating the thermal rate constant with exponential speedup on a quantum computer

It is shown how to formulate the ubiquitous quantum chemistry problem of calculating the thermal rate constant on a quantum computer. The resulting exact algorithm scales exponentially faster with the dimensionality of the system than all known ``classical'' algorithms for this problem.
Properties of the induced acid phosphatase and of the constitutive acid phosphatase of Euglena.

Enzymatic activity and inhibition, thermal stability and electrophoretic properties of induced and constitutive acid phosphatases of Euglena gracilis