cssi/SciSciGPT-SciSciNet huggingface dataset:
Performance implications of multi-tier application deployments on Infrastructure-as-a-Service clouds: Towards performance modeling

Hosting a multi-tier application using an Infrastructure-as-a-Service (IaaS) cloud requires deploying components of the application stack across virtual machines (VMs) to provide the application's infrastructure while considering factors such as scalability, fault tolerance, performance and deployment costs (# of VMs). This paper presents results from an empirical study which investigates implications for application performance and resource requirements (CPU, disk and network) resulting from how multi-tier applications are deployed to IaaS clouds. We investigate the implications of: (1) component placement across VMs, (2) VM memory size, (3) VM hypervisor type (KVM vs. Xen), and (4) VM placement across physical hosts (provisioning variation). All possible deployment configurations for two multi-tier application variants are tested. One application variant was computationally bound by the application middleware, the other bound by geospatial queries. The best performing deployments required as few as 2 VMs, half the number required for VM-level service isolation, demonstrating potential cost savings when components can be consolidated. Resource utilization (CPU time, disk I/O, and network I/O) varied with component deployment location, VM memory allocation, and the hypervisor used (Xen or KVM) demonstrating how application deployment decisions impact required resources. Isolating application components using separate VMs produced performance overhead of ~1%-2%. Provisioning variation of VMs across physical hosts produced overhead up to 3%. Relationships between resource utilization and performance were assessed using multiple linear regression to develop a model to predict application deployment performance. Our model explained over 84% of the variance and predicted application performance with mean absolute error of only ~0.3 s with CPU time, disk sector reads, and disk sector writes serving as the most powerful predictors of application performance.
Selenoprotein levels in patients with colorectal adenomas and cancer

OBJECTIVES: Selenium is a trace mineral that, as a constituent of certain selenoproteins, acts as an antioxidant. Results of studies addressing a cancer protective effect of selenium have been controversial. The present study measured selenoprotein-P, extracellular glutathione peroxidase, and plasma selenium in patients with colon cancer and adenomatous colon polyps to determine whether patients who develop colorectal adenomas or cancer are selenium deficient. METHODS: Patients who presented to an endoscopy center for colonoscopy or who were referred to our institution with a newly diagnosed colorectal cancer were offered enrollment in the trial. Each patient underwent phlebotomy, usually immediately after colonoscopy. In all, 103 patients were enrolled in the study. Of these, 33 patients were found to have colorectal cancer, 35 adenomatous colon polyps, and 17 normal examinations. A total of 18 patients had other diagnoses and were not included in the study group. RESULTS: The mean age for the colorectal cancer group was 69 yr, for the adenomatous colon polyp group 62 yr, and for the normal group was 56 yr. The adenomatous colon polyp and normal groups were predominantly female. Based on one way analysis of variance tests, there was no significant difference in selenoprotein-P or plasma selenium levels or extracellular glutathione peroxidase activity among the three groups (p = 0.28, 0.098, and 0.35 respectively). CONCLUSIONS: The present data suggest that patients with adenomatous colon polyps and those with colorectal cancer are not selenium deficient.
Time course of temperature effects on arterial acid-base status in Alligator mississippiensis.

Abstract Temperature effects on extracellular acid-base status in terrestrial poikilotherms are well known. Comparatively less is known concerning the time course of acid-base responses to prolonged changes in temperature. In this study, two questions were addressed: (1) what is the time course of acid-base responses to a temperature change of 5 days duration in Alligator mississippiensis ?; and (2) what are the relative contributions of respiratory vs metabolic (strong ion) processes to the acid-base response? The effects of acute (4–6 h) vs chronic (24–120 h) decreases in ambient temperature from 30 to 20°C were determined on arterial blood gases, acid-base status and plasma electrolyte concentrations ([Na + ], [K + ] and [Cl − ]) in 7 awake alligators. In addition, in vivo and in vitro non-bicarbonate buffer values were determined in 6 anesthetized alligators. Acute decreases in temperature decreased Pa CO 2 (31 to 18 mmHg) and Pa O 2 (91 to 50 mmHg), increased pH (7.48 to 7.66), but had no significant effect on plasma bicarbonate concentration ([HCO 3 − ]). Chronic exposure to 20°C had no further effect on any variable. dpH/dT ranged between −0.018 and −0.011 U/°C, over the duration of the experiment. Temperature did not alter [Na + ] or [Cl − ] at any time, and had only minor effects on [K + ]. In vivo (11.5±0.7 mEq/L/pH unit) and in vitro (16.1±0.9 mEq/L/pH unit) buffer values were significantly different, but neither was affected by temperature. Temperature had no effect on the base excess (estimated with either in vitro or in vivo buffer values), nor on estimates of the strong ion difference. We conclude that pH changes during prolonged exposure to decrease temperature occur rapidly and can be explained by changes in Pa CO 2 , CO 2 solubility and pK′, without major contributions from metabolic or strong ion adjustments.
Measurement Error Models with Auxiliary Data

We study the problem of parameter inference in (possibly non-linear and non-smooth) econometric models when the data are measured with error. We allow for arbitrary correlation between the true variables and the measurement errors. To solve the identification problem, we require the existence of an auxiliary data-set that contains information about the conditional distribution of the true variables given the mismeasured variables. Our main assumption requires that the conditional distribution of the true variables given the mismeasured variables is the same in the primary and auxiliary data. Our methods allow the auxiliary data to be a validation sample, where the primary and validation data are from the same distribution, and more importantly, a stratified sample where the auxiliary data-set is not from the same distribution as the primary data. We also show how to combine the two data-sets to obtain a more efficient estimator of the parameter of interest. We establish the large sample properties of the sieve based estimators under verifiable conditions. In particular, we allow for the mismeasured variables to have unbounded supports without employing the tedious trimming scheme typically used in kernel based methods. We illustrate our methods by estimating a returns to schooling censored quantile regression using the CPS/SSR 1978 exact match files where the dependent variable is measured with error of arbitrary kind.
Surface evolution of dissolving minerals investigated with a kinetic Ising model

In natural weathering systems, both the chemistry and the topography of mineral surfaces change as rocks and minerals equilibrate to surface conditions. Most geochemical research has focused on changes in solution chemistry over time; however, temporal changes in surface topography may also yield information about rates and mechanisms of dissolution. We use stochastic dissolution simulations of a regular 2-D lattice with reaction mechanisms defined in terms of nearest neighbor interactions to elucidate how the surface area and reactivity of a crystal evolve during dissolution. Despite the simplicity of the model, it reproduces key features observed or inferred for mineral dissolution. Our model results indicate that: (i) dissolving surfaces reach a steady-state conformation after sufficient dissolution time, (ii) linear defects cause surface area and dissolution rate to vary in concert with one another, (iii) sigmoidal and non-sigmoidal rate vs. free-energy of reaction (ΔGrxn) behavior can be rationalized in terms of the multiple steps occurring during dissolution, and (iv) surface roughness as a function of ΔGrxn is highly sensitive to the reaction mechanism. When simulated times to reach steady-state are compared to published time series rate data using suitable scaling, good agreement is found for silicate minerals while the model significantly over-predicts the duration of the transient for Fe and Al oxides. The implication of our simple model is that many aspects of mineral dissolution behavior, including approach to steady-state, sigmoidal vs. non-sigmoidal rate vs. ΔGrxn behavior, and development of rougher surfaces in conditions further from equilibrium can be explained by nearest neighbor interactions and simple Kossel-type models where reactivity of a surface is defined in terms of perfect surface, step, and kink sites.
Detection of HIV-1 proviral DNA with the AMPLICOR HIV-1 DNA Test, version 1.5, following sample processing by the MagNA Pure LC instrument.

Abstract Background The AMPLICOR® HIV-1 DNA Test, version 1.5 (AMP HIV-1 DNA 1.5), is a new commercially available PCR assay for the detection of human immunodeficiency virus type 1 (HIV-1) proviral DNA in human whole blood. Objective This study evaluates the performance characteristics of the assay following automated sample processing by the MagNA Pure LC instrument (MP). Study design Analytical sensitivity and reproducibility were assessed by testing replicate HIV-1 DNA dilution panels over 5 days. Clinical sensitivity and specificity were studied among 28 HIV-1 DNA-positive clinical specimens, 60 specimens from healthy blood donors, and 63 specimens from HIV-1-seropositive patients with HIV-1 RNA plasma levels ranging from 100,000 copies/mL. Results Following MP sample processing, the assay yielded an analytical sensitivity (95% detection rate) of 66.3 copies/mL (95% CI, 50.7–106.8), with clinical sensitivity and specificity of 100%. Conclusions MP is a reliable, labor-saving platform capable of processing specimens for AMP HIV-1 DNA 1.5. When combined with MP sample processing, AMP HIV-1 DNA 1.5 is a sensitive and reproducible assay for the detection of HIV-1 DNA in clinical whole blood specimens. However, the current AMP HIV-1 DNA 1.5 kit configuration may result in inefficient utilization of reagents.
Catabolism of rat surfactant disaturated phosphatidylcholines during incubation of alveolar lavage materials in vitro at 37°C

Incubation of rat alveolar lavage materials in vitro at 37 degrees C results in degradation of the endogenous surfactant disaturated phosphatidylcholines (disaturated PC). When exogenous dipalmitoylphosphatidylcholine (DPPC) vesicles are incubated with lavage materials, there is catabolism of the DPPC. The degradation process is temperature- and Ca2+-dependent and has a pH optimum of 6.5-7.0. The products formed during catabolism of [3H]palmitate- and [14C]choline-labeled disaturated PC are free palmitate and water-soluble choline products. No lysophosphatidylcholines are formed. Measurements of lactate dehydrogenase levels in lavage fluid, use of more gentle lavage techniques, use of Ca2+, Mg2+ and protein in the lavage medium, and measurements of bacterial contamination all suggest that enzymes are neither released into pulmonary lavage fluid via cellular damage nor are bacterial in origin. Degradation of surfactant disaturated PC does not occur during incubation of lavage materials from rabbits, mice or guinea pigs. These results suggest that phospholipases and/or lysophospholipases are present in rat alveolar lavage materials. Possible origins of these enzymes are discussed.
The effects of a glucose load and sympathetic challenge on autonomic function in obese women with and without type 2 diabetes mellitus

This study examined the effect of glucose ingestion on cardiac autonomic function in nonobese women and obese women with and without type 2 diabetes mellitus. Heart rate variability was measured via continuous electrocardiogram, and beat-by-beat blood pressure was recorded using finger photoplethysmography (Portapres, TNO Biomedical Instrumentation, Amsterdam, The Netherlands) in a fasted state and in response to a 75-g glucose load in 42 middle-aged women (40-60 years). Upright tilt was also used as an orthostatic stress to provide a clinically relevant challenge to the cardiovascular system. Significant main effects for log-transformed (Ln) total power (TP, square milliseconds) were observed with upright tilt (P < .01) and glucose challenge (P < .05). LnTP decreased in all groups in both the fasted and fed state with upright tilt (P < .01), but glucose ingestion resulted in higher LnTP in the supine position only (P = .008). Tilt resulted in a significant main effect for low-frequency (LFnu, calculated in normalized units) and high-frequency (HFnu, calculated in normalized units) power (P < .000), whereas the glucose challenge had no effect on LFnu or HFnu power. LFnu approached significance for group differences (P = .07), such that the nonobese had lower LF power than either of the obese groups. Sympathovagal balance (LnLF/HF ratio) was affected by position (P < .000) and group (P < .05), with a lower LnLF/HF in the nonobese than in the obese women. Baroreceptor sensitivity decreased (P < .01) during upright tilt but was not changed by the glucose challenge. In conclusion, basal sympathovagal balance is higher in obese individuals with and without type 2 diabetes mellitus. Women with type 2 diabetes mellitus showed no differences in autonomic function with an orthostatic challenge or glucose load than nondiabetic, obese women. The glucose load did alter total spectral power in all of these middle-aged women but had no impact on baroreceptor sensitivity.
Effect of Utterance Length and Meaningfulness on the Speech Initiation Times of Children Who Stutter and Children Who Do Not Stutter

The purpose of this study was to determine the effect of utterance length and meaningfulness on the speech initiation times of children who stutter and children who do not stutter. Subjects were 36 elementary school students (half of whom stutter, matched by age, grade, and gender). Each child repeated short meaningful, long meaningful, and long nonce utterances in response to a visual cue. Nonstuttering, stuttering-only, and stuttering-plus (children with concomitant speech and/or language problems) children responded differently to utterance length and meaningfulness. This suggests that the three groups may process speech motor events for verbal responses differently.
Chronic myelogenous leukemia

Case Presentation A 70-year-old female went to her rheumatologist for a routine follow-up visit for rheumatoid arthritis and Sjogren’s syndrome on October 17, 2000. At that time, she did not have any complaints apart from her baseline medical conditions. The patient did have several other medical conditions including osteoporosis, hypothyroidism, depression, hypertension, and hypercholesterolemia. The medications she was taking included Plaquenil, Ketoprofen, Sulfasalazine, Artificial Tears, Fosamax, Caltrate, Synthroid, Prozac, Norvasc, Atenolol, and Lipitor. A routine complete blood count (CBC) demonstrated a white blood cell count (WBC) of 29,400/μl. Her previous CBC (in June 2000) demonstrated a WBC of 10,900/μl. She was referred to an oncologist where she reported no fevers, bleeding, or other symptoms. Analysis of her bone marrow determined that she had a blast count of less than 1% and that blasts and promyelocytes made up less than 10% of the cells seen. The immunophenotype by flow cytometry found that 92% of cells had mature granulocytic elements and also exhibited an aberrant expression of CD56. Cytogenetic testing was performed in addition to morphologic analysis of her blood and bone marrow to determine her diagnosis.
Antibodies to the neuronal cytoskeleton are elicited by Alzheimer paired helical filament fractions

Abstract Antibodies were raised to paired helical filament (PHF) enriched fractions obtained from brains of individuals with Alzheimer disease by extraction with ionic detergent followed by sucrose gradient centrifugation. Electron microscopic examination showed that the fractions were enriched in Alzheimer PHF but contained also lipofuscin, amyloid, granular material and membranous elements. Analysis of these fractions with SDS-PAGE stained with Coomassie blue showed only a faint band at approximately 60 kDa while most of the material was excluded from the stacking gel. BALB/c mice were injected weekly with 100 or 200 μg of these fractions or corresponding fractions from age-matched control brains. The 3 mice injected with Alzheimer brain, but not the 5 mice injected with control brain fractions, produced antibodies that reacted with central and peripheral nervous system axons, Alzheimer neurofibrillary tangles in intact tissue as well as with isolated, SDS-treated paired helical filaments. In gel strips antibodies from all 3 mice injected with Alzheimer brain fractions reacted with the 200-kDa and 168-kDa but not the 68-kDa neurofilament subunits. The 3 antisera reacted also with some forms of the microtubule-associated protein τ. Adsorptions with the insoluble fraction from Alzheimer but not from control brains blocked staining of axons and NFT by all 3 antisera. Adsorption with highly purified neurofilament proteins or with a preparation containing the 200-kDa 168-kDa neurofilament subunits blocked axon and NFT immunostaining only in one antiserum. Adsorptions with microtubule protein, heat-stable microtubule-associated protein, or a preparation of τ did not completely block immunostaining by any of the 3 antisera. These results demonstrate that fractions enriched with Alzheimer paired helical filaments contain insoluble neurofilament, τ and other yet unidentified antigens.
Methods for characterization of erosion by gas-entrained solid particles

Abstract The effects of the variables in the gas jet method of erosion testing on erosion rates of metals are quantitatively assessed. Criteria for the preparation of metal specimens used in solid-gas erosion testing are presented. A specific design of gas jet equipment and method of erosion testing are described and methods for measurement of solid particle velocity are reviewed. An experimental velocity measurement technique based on time-series analysis is proposed. The effect of sample preparation and data analysis methods on reproducibility of measured erosion rates is presented. A method for data analysis to minimize errors in reported erosion rates is described.
A finite element model of electromigration induced void nucleation, growth and evolution in interconnects

We describe a two-dimensional finite element method designed to model the nucleation, growth and evolution of voids in polycrystalline interconnects. Our computations extend earlier models by accounting in detail for the effects of grain boundaries and interfaces in the solid. In particular, the model includes the effects grain boundary sliding, grain boundary diffusion, grain boundary migration and surface diffusion, as well as elastic deformation and electric current flow within the grains themselves. Front tracking and adaptive mesh generation are used to follow changes in the grain structure and void shape. The method is used to solve representative boundary value problems to illustrate its capabilities.
Anti-Minotaur: The Myth of a Sociological Morality

Recently Philip Gorski has argued that sociology can help us answer moral questions such as how to live and how to organize societies. Gorski rejects “value-free sociology” and the distinction between factual statements and value judgments, but actually factual statements and value judgments are distinct and sociology can be value-free. The practice of value-free sociology is ethically imperative, even, if we are to be honest with our audiences and if we are to fulfill our vocation as sociologists.
Growth and alloying of Pd films on Mo(110) surfaces

Abstract The growth and annealing behavior of Pd on Mo(110) is studied in the thickness range from 0 to 12 monolayers at temperatures up to 1300 K using AES, XPS, LEED and work function change measurements. Similar to Pd on W(110), different growth modes are found at room and elevated temperatures. Dissimilar to Pd on W(110), the monolayer structure is different. Clear evidence for alloying is seen once the films are thick enough to remain continuous during annealing at temperatures up to 1100 K. At lower thicknesses the layers agglomerate during annealing. A model in which Pd-Mo alloy islands are surrounded by a distorted thin layer (1–2 ML) of Pd fits the results very well.
Technique for measuring the refractive index and its change with temperature in the infrared

A simple method for measuring refractive index in the infrared is described. It uses autocollimation from the front surface of a prism and requires only that the receiver be moved to measure a new deviated ray when either the wavelength of the source or the temperature of the sample is changed. An error analysis that includes consideration of the evacuated sample space and wedge in the chamber windows shows that errors as low as one part in the fourth decimal place can be obtained.
Control of osteoclastogenesis and bone resorption by members of the TNF family of receptors and ligands

Abstract Skeletal mass is maintained by a balance between cells which resorb bone (osteoclasts) and cells which form bone (osteoblasts). Bone development and growth is an on-going, life-long process. Bone is formed during embryonic life, grows rapidly through childhood, and peaks around 20 years of age (formation exceeds resorption). For humans the skeleton then enters a long period, approximately 40 years, when bone mass remains relatively stable. Skeletal turnover continues but the net effect of resorption and formation on bone mass is zero. For women this ends when they enter menopause and similar bone loss occurs for men, but later in life. These opposite functions are coupled, resorption precedes formation, and osteoblasts, or their precursors, stromal cells, regulate osteoclast formation and activity. Until recently, the molecular nature of this regulation, was poorly understood. However, recent observations have identified members of the TNF family of ligands and receptors as critical regulators of osteoclastogenesis. Osteoprotegerin (OPG) a decoy receptor was first identified. Its ligand, receptor activator of nuclear factor-κB ligand (RANKL), was quickly found, and shown to be expressed on stromal cells and osteoblasts. Its cognate receptor, RANK, was found to be expressed in high levels on osteoclast precursors. The interaction between RANKL and RANK was shown to be required for osteoclast formation. These observations have provided a molecular understanding of the coupling between osteoclastic bone resorption and osteoblastic bone formation. Moreover, they provide a framework on which to base a clear understanding of normal (e.g. postmenopausal osteoporosis and age associated bone loss) and pathologic skeletal changes (e.g. osteopetrosis, glucocorticoid-induced osteoporosis, periodontal disease, bone metastases, Paget's disease, hyperparathyroidism, and rheumatoid arthritis).
Motion Artifacts in fMRI: Comparison of 2DFT with PR and Spiral Scan Methods

Activation signals based on BOLD contrast changes consequent to neuronal stimulation typically produce cortical intensity differences of < 10% at 1.5T. Hemodynamically driven pulsation of the brain can cause highly pulsatile phase shifts, which in turn result in motion artifacts whose intensity is larger than the activation signals in 2DFT scan methods. This paper presents a theoretical and experimental comparison of the magnitude of such artifacts for 2DFT and two other methods using non-Cartesian k-space trajectories. It is shown that artifacts increase with TR for 2DFT methods, and that projection reconstruction (PR) and spiral methods have significantly reduced artifact intensities, because these trajectories collect low spatial frequencies with every view. The spiral technique is found to be superior in terms of efficiency and motion insensitivity.
Crystal-variant-based modeling of relaxor single crystals

Rhombohedral relaxor single crystals are a class of materials that includes PZN-xPT and PMN-xPT in a certain range of compositions. This work presents an approach to predicting the physical properties of engineered domain state crystals. A model based on the properties of the crystal variants and volume averaging provides a method for determining a full set of the piezoelectric coefficients for the rhombohedral single domain. The model suggests there is a large d15 and the existence of d16 for the orientation cuts of PZN-PT and PMN-PT crystals. The approach has led to the identification of engineered domain states with properties optimized for specific applications such as the large transverse piezoelectric coefficients of the orientation. This cut has optimal properties for actuator and sensor applications that utilize the transverse mode piezoelectric coupling coefficients (d 31 and d 32 ).
A novel planar flow cell for studies of biofilm heterogeneity and flow–biofilm interactions

Biofilms are microbial communities growing on surfaces, and are ubiquitous in nature, in bioreactors, and in human infection. Coupling between physical, chemical, and biological processes is known to regulate the development of biofilms; however, current experimental systems do not provide sufficient control of environmental conditions to enable detailed investigations of these complex interactions. We developed a novel planar flow cell that supports biofilm growth under complex two-dimensional fluid flow conditions. This device provides precise control of flow conditions and can be used to create well-defined physical and chemical gradients that significantly affect biofilm heterogeneity. Moreover, the top and bottom of the flow chamber are transparent, so biofilm growth and flow conditions are fully observable using non-invasive confocal microscopy and high-resolution video imaging. To demonstrate the capability of the device, we observed the growth of Pseudomonas aeruginosa biofilms under imposed flow gradients. We found a positive relationship between patterns of fluid velocity and biofilm biomass due to faster microbial growth under conditions of greater local nutrient influx, but this relationship eventually reversed because high hydrodynamic shear leads to the detachment of cells from the surface. These results reveal that flow gradients play a critical role in the development of biofilm communities. By providing new capability for observing biofilm growth, solute and particle transport, and net chemical transformations under user-specified environmental gradients, this new planar flow cell system has broad utility for studies of environmental biotechnology and basic biofilm microbiology, as well as applications in bioreactor design, environmental engineering, biogeochemistry, geomicrobiology, and biomedical research.
The role of adrenal corticosteroids in the regulation of kidney function in the desert lizard Dipsosaurus dorsalis.

Abstract 1. 1. Renal responses of the lizard Dipsosaurus dorsalis to chronic administration of water, 50 mM NaCl and 150 mM NaCl were studied. 2. 2. D. dorsalis responded to these injections by reducing or increasing sodium excretion by means of appropriate variations in fractional reabsorption of sodium. 3. 3. Corticosteroidogenesis increased in response to saline loads but was unchanged with chronic water loading. 4. 4. Dexamethasone significantly inhibited the normal response to NaCl loading. 5. 5. Responses to aldosterone and spirolactone injections were negligible and suggest that aldosterone is not involved in the control of renal sodium excretion.
Growth of high‐quality epitaxial GaAs films by sputter deposition

Epitaxial GaAs films have been grown on (100) Cr‐doped GaAs substrates by sputter deposition from an undoped GaAs target. Unintentionally doped samples were high resistivity (105–106 Ω cm) n type with room temperature mobilities as high as 5000 cm2/V sec. Residual oxygen and carbon contamination was minimized through the use of a liquid‐nitrogen‐cooled shroud surrounding the discharge during deposition. Excess arsenic was provided to the growing film from an effusion cell. Film doping was accomplished using either an evaporated source (Mn) or the addition of a gas‐phase impurity (H2S) during sputter deposition. Mn‐doped p‐type films were grown with room‐temperature carrier concentrations between 1.3×1017 and 2.5×1018 cm−3 and corresponding hole mobilities of 240–95 cm2/V sec. The S‐doped films were n‐type with S concentrations, as determined by secondary‐ion mass spectrometer (SIMS), up to the solid solubility limit and sharp doping profiles with widths of ∼200 A. In all cases the dopant incorporation pro...
Robust control synthesis for uncertain/nonlinear dynamical systems

This paper addresses the problem of robust output-feedback controller design for uncertain and nonlinear dynamic systems. First a robust state-feedback nonlinear control law is synthesized. This control strategy practically stabilizes the closed-loop system. Then a state estimator for the nonlinear/uncertain plant is designed and its performance analyzed. Finally the control law and the estimator are combined and the practical stability region is estimated. The results are illustrated by their application to a benchmark problem for robust control design proposed by Wie and Bernstein (1990).
D-ribose-5-phosphate isomerase from spinach: heterologous overexpression, purification, characterization, and site-directed mutagenesis of the recombinant enzyme.

Abstract A cDNA encoding spinach chloroplastic ribose-5-phosphate isomerase (RPI) was cloned and overexpressed in Escherichia coli, and a purification scheme for the recombinant enzyme was developed. The purified recombinant RPI is a homodimer of 25-kDa subunits and shows kinetic properties similar to those of the homodimeric enzyme isolated from spinach leaves (A. C. Rutner, 1970, Biochemistry 9, 178–184). Phosphate, used as a buffer in previous studies, is a competitive inhibitor of RPI with a K i of 7.9 mM. d -Arabinose 5-phosphate is an effective inhibitor, while d -xylulose-5 phosphate is not, indicating that the configuration at carbon-3 contributes to substrate recognition. Although d -arabinose 5-phosphate binds to RPI, it is not isomerized, demonstrating that the configuration at carbon-2 is crucial for catalysis. Alignment of RPI sequences from diverse sources showed that only 11 charged amino acid residues of the 236-residue subunit are conserved. The possible function of four of these residues was examined by site-directed mutagenesis. D87A, K100A, and D90A mutants show greatly diminished k cat values (0.0012, 0.074, and 0.38% of the wild type, respectively), while E91A retains substantial activity. Only insignificant or moderate changes in K m of d -ribose 5-phosphate are observed for D87A, K100A, and D90A, indicating a direct or indirect catalytic role of the targeted residues.
On the structure of the flow due to the collision of opposed, vertical, free convection, boundary layers

Abstract Preliminary experimental results are reported for the structure of the flow due to the collision of a pair of boundary layers driven towards each other by buoyant forces along a vertical wall. Of the possible parameters characterizing the flow, a Rayleigh number ratio, R, and a dimensionless temperature difference, n, emerge as important. When 0.6 0.20 “fingering” of fluid between the streams and cross-stream secondary flows occur.
XAMP: An eXtensible Analytical Model Platform

Analytical modeling plays a unique and important role in computer architecture design, providing a first-order estimate, reducing the design search space size for simulation, or giving insights on basic relationships between various variables and parameters. However, current practices in using analytical models face considerable hurdles: models vary widely in types, predictive capability, and assumptions they rely on, creating a high barrier of entry. Consequently, the high barrier prevents wide adoption of analytical models. In this paper, we propose a tool that integrates analytical models into a single extensible platform that provides a uniform interface and model query engine. Users can perform input-based search (searching what outputs can be predicted by models given a set of available inputs), output-based search (searching what inputs are required in order for models to produce the desired outputs), or both combined. The query engine also analyzes various ways in which models can be connected so that they can be combined to extend the prediction capabilities beyond individual models' capabilities. The tool can be extended to include new models, allowing it to evolve as more models are added, and allowing collaborative model development. We refer to the tool as XAMP (eXtensible Analytical Model Platform). We believe XAMP is a useful first step toward lowering the barrier of entry for using and developing analytical models.
Recovery from anorexia nervosa includes neural compensation for negative body image.

Objective: To examine whether frontal lobe mediated regulation of emotion permits women to recover from anorexia nervosa (AN). Method: Brain activity associated with the disruption of working memory by images of bodies was examined in women who had recovered from AN and in control women. Results: Negatively rated images were more disruptive to working memory than neutral or positively rated images in both groups; however, amygdala and fusiform activation were greater in women who had recovered from AN than in controls when viewing images of bodies during the working memory task. There were no group differences in lateral prefrontal activity. However, there was more suppression of medial prefrontal cortex activity in women who had recovered from AN in comparison to controls when negatively rated images were presented during the working memory task. Discussion: These results suggest that recovery from AN is not achieved by dampening an amygdala mediated emotional response to bodies, but instead by developing compensatory neural mechanisms that prevent emotional responses from disturbing cognition. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
CRAFFT: an activity prediction model based on Bayesian networks

Recent advances in the areas of pervasive computing, data mining, and machine learning offer unique opportunities to provide health monitoring and assistance for individuals facing difficulties to live independently in their homes. Several components have to work together to provide health monitoring for smart home residents including, but not limited to, activity recognition, activity discovery, activity prediction, and prompting system. Compared to the significant research done to discover and recognize activities, less attention has been given to predict the future activities that the resident is likely to perform. Activity prediction components can play a major role in design of a smart home. For instance, by taking advantage of an activity prediction module, a smart home can learn context-aware rules to prompt individuals to initiate important activities. In this paper, we propose an activity prediction model using Bayesian networks together with a novel two-step inference process to predict both the next activity features and the next activity label. We also propose an approach to predict the start time of the next activity which is based on modeling the relative start time of the predicted activity using the continuous normal distribution and outlier detection. To validate our proposed models, we used real data collected from physical smart environments.
Short-term clinical success of root-form titanium implant systems

Abstract Original review Esposito M, Coulthard P, Worthington HV, Jokstad A, Wennerberg A. Interventions for replacing missing teeth: Different types of dental implants (Cochrane Review). In: The Cochrane Library, Issue 1, 2003. Oxford: Update Software. Date of most recent amendment: 9 July 2002. Level of evidence 1a Purpose To test the null hypothesis that there was no difference in clinical performance between various root-formed osseointegrated implant types Source of funding Industry support for most included studies Type of study/design Systematic review
Effects of mixed abrasive grits in slurries on free abrasive machining (FAM) processes

Effects of mixed abrasive grits in slurries on free abrasive machining (FAM) processes are studied using a single-sided lapping machine. Impacts of mixing abrasives on various parameters such as amount of material removed, material removal rate, surface roughness, particle size distribution and relative angular velocity are studied. The material removed is monitored as a function of time. The experimental results suggest that (i) mixing abrasive grits can increase the amount of material removed, (ii) smaller abrasives can directly or indirectly affect the material removal process, (iii) slurries undergo severe grain size transition during lapping, and (iv) the surface roughness did not change significantly under different loading. The results of this study may have profound implication on the FAM processes that practitioners use today because the mixed abrasive grits increase material removal rate and reduce the grain size transition, while rendering similar surface roughness.
Obstetric anesthesia: Not just for cesareans and labor

The scope of obstetric anesthesia practice ranges far beyond the delivery of care to women for vaginal and cesarean deliveries. Increasingly, obstetric anesthesiologists are involved in the management of anesthetics for new procedures and for new indications. Anesthesia is frequently needed for maternal procedures, as well as fetal procedures, and at varying times in the intrapartum period. Maternal-specific procedures include cerclage, external cephalic version (ECV), postpartum bilateral tubal ligation (BTL), and dilation and evacuation (D and E). Fetus-specific procedures include fetoscopic laser photocoagulation and ex-utero intrapartum treatment (EXIT). This review will not include discussion of the anesthetic management of non-obstetric surgery during pregnancy, such as appendectomy or cholecystectomy.
Post‐processing removal of correlated errors in GRACE data

[1] Gravity fields produced by the Gravity Recovery and Climate Experiment (GRACE) satellite mission require smoothing to reduce the effects of errors present in short wavelength components. As the smoothing radius decreases, these errors manifest themselves in maps of surface mass variability as long, linear features generally oriented north to south (i.e., stripes). The presence of stripes implies correlations in the gravity field coefficients. Here we examine the spectral signature of these correlated errors, and present a method to remove them. Finally, we apply the filter to a model of surface-mass variability to show that the filter has relatively little degradation of the underlying geophysical signals we seek to recover.
Spatial structure of a diving duck (Aythya, Oxyura) guild: how does habitat structure and competition influence diving duck habitat use within northern prairie wetlands?

What circumstances allow the coexistence of similar species is a common but complex question in community ecology. It is often assumed that sympatric species within the same guild must employ some ...
Characterization of the solvent-induced nonlinear response of ionic polymer actuators

Ionic polymer transducers exhibit coupling between the electrical, chemical, and mechanical domains, allowing their use as both sensors and actuators. Because of their compliance, light weight, and low voltage operation, ionic polymers have spawned an area of much research, although their fundamental mechanisms are still open for debate. While most of the existing models provide linear, dynamic approximations of the response, nonlinear characteristics have been observed experimentally. Some of these include the introduction of permanent strain in the step response and distortion in the forced response to harmonic excitations. Recent experimental results have shown that the solvent plays a significant role in the dynamic response of ionic polymer actuators. Given a single-frequency input voltage, the major difference from changing solvent materials was concluded to be a nonlinear distortion with varying influence, seen in both the actuation current and tip velocity measurements. These results compared the response of a water-based sample to a sample prepared with the ionic liquid EMI-Tf, where it was found that the voltage-to-current relationship was much more nonlinear in the water sample, while it was predominantly linear with the ionic liquid sample. This research looks to further explore this nonlinear distortion by incorporating a larger set of candidate solvent materials and investigating the impact of how changing properties affect the overall response. System identification techniques using the Volterra series are employed to aid in the characterization of the harmonic distortion. The knowledge gained in this study will provide useful information about the nature of the nonlinearity and some of the factors that affect its relative influence, which will assist physical model development.
Development of a microchannel based pasteurizer for energy efficient processing of liquids

Abstract This study focuses on the development of an energy efficient small-scale pasteurizer for processing liquids having biological contamination. The device has three sections that perform vital functions in the pasteurization process. The first is a microchannel counterflow heat exchanger for the recovery of thermal energy in the outgoing flow to heat the incoming flow. The second section also uses microchannels along with cartridge heaters to bring the preheated flow to approximately 150 °C. The third section is a residence chamber that ensures the flow remains at approximately 150 °C for at least 2 s satisfying the requirements for Ultra High Temperature (UHT) pasteurization. The integrated compact device has a characteristic channel height of less than 0.2 mm and was composed of chemically etched and diffusion bonded stainless steel shims. The design was improved with CFD modeling with validation from point measurements of the internal fluid temperature. Thermal and biological testing demonstrated successful operation; the heat exchanger effectiveness was shown to be more than 90% and samples collected showed no colony-forming bacteria at the design conditions of UHT pasteurization and 100 mL/min flow.
Compact modeling of multi-gate MOSFETs for RF designs

Multi-gate MOSFETs (MuGFETs) such as FinFET, tri-gate, and ETSOI MOSFETs are becoming the new mainstream manufacturing technologies and providing a new platform for RF integration in advanced SOCs. This paper reviews SPICE modeling infrastructure readiness for MuGFETs by examining major compact models for symmetric and asymmetric MuGFETs with an emphasis on RF applications. Comparative analysis and recommendations for improvement are provided.
Nuclear forensics in law enforcement applications

Over the past several years, the Livermore Forensic Science Center has conducted analyses of nuclear-related samples in conjunction with domestic and international criminal investigations. Law enforcement officials have sought conventional and nuclear-forensic analyses of questioned specimens that have typically consisted of miscellaneous metal species or actinide salts. The investigated activities have included nuclear smuggling and the proliferation of alleged fissionable materials, nonradioactive hoaxes such as “Red Mercury,” and the interdiction of illegal laboratories engaged in methamphetamine synthesis.
Measles virus, immune control, and persistence

Measles remains one of the most important causes of child morbidity and mortality worldwide with the greatest burden in the youngest children. Most acute measles deaths are owing to secondary infections that result from a poorly understood measles-induced suppression of immune responses. Young children are also vulnerable to late development of subacute sclerosing panencephalitis, a progressive, uniformly fatal neurologic disease caused by persistent measles virus (MeV) infection. During acute infection, the rash marks the appearance of the adaptive immune response and CD8(+) T cell-mediated clearance of infectious virus. However, after clearance of infectious virus, MeV RNA persists and can be detected in blood, respiratory secretions, urine, and lymphoid tissue for many weeks to months. This prolonged period of virus clearance may help to explain measles immunosuppression and the development of lifelong immunity to re-infection, as well as occasional infection of the nervous system. Once MeV infects neurons, the virus can spread trans-synaptically and the envelope proteins needed to form infectious virus are unnecessary, accumulate mutations, and can establish persistent infection. Identification of the immune mechanisms required for the clearance of MeV RNA from multiple sites will enlighten our understanding of the development of disease owing to persistent infection.
Peptide sequencing using MALDI on time-of-flight and ion trap mass spectrometers

Two instruments have been developed in our laboratory for the direct amino-acid sequencing of peptides. The first is a time-of-flight (TOF) mass spectrometer that utilizes a coaxial, curved-field reflectron which provides simultaneous focusing of product ins formed by post- source decay (PSD) and obviates the need for scanning or stepping the reflectron voltage. The second is a matrix-assisted laser desorption/ionization (MALDI) ion trap mass spectrometer (ITMS). In this instrument, MALDI ions are trapped efficiently by ramping the trapping rf field, and a linear mass scale is achieved by modulating the axial excitation voltage during mass scanning. Monoisotopic mass selection and excitation is accomplished using phase- modulated SWIFT (stored waveform inverse Fourier transform) techniques, while efficient CID (collision-induced dissociation) performance is achieved using pulsed introduction of Xe and other heavier gases. Both mass spectrometers have been designed as compact instruments for sequencing peptides in partially fractionated mixtures.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.