cssi/SciSciGPT-SciSciNet huggingface dataset:
From Coalgebra to Bialgebra for the Six-Vertex Model: The Star-Triangle Relation as a Necessary Condition for Commuting Transfer Matrices

Using the most elementary methods and considerations, the solution of the star-triangle condition (a2+b2-c2)/2ab = ((a’)^2+(b’)^2-(c’))^2/2a’b’ is shown to be a necessary condition for the extension of the operator coalgebra of the six-vertex model to a bialgebra. A portion of the bialgebra acts as a spectrum-generating algebra for the algebraic Bethe ansatz, with which higher-dimensional representations of the bialgebra can be constructed. The star-triangle relation is proved to be necessary for the commutativity of the transfer matrices T(a, b, c) and T(a’, b’, c’).
Silica sol‐gel for the controlled release of antibiotics. II. The effect of synthesis parameters on the in vitro release kinetics of vancomycin

Room temperature-processed silica sol-gel (xerogel) was investigated as a novel controlled release carrier of vancomycin for the treatment of osteomyelitis. Vancomycin-loaded xerogels were fabricated with varying water/alkoxysilane molar ratios and vancomycin concentrations. The goal of this study was to determine the effect of varying the aforementioned synthesis parameters on the daily in vitro release kinetics of vancomycin from the xerogel disks. A controlled, load-dependent, long-term release of vancomycin was observed for all of the molar ratios that were used in the study (4, 6, and 10). Variations in the water/alkoxysilane molar ratio affected the release process extensively. A cumulative release of about 90% of the original amount of vancomycin was found for molar ratios 6 and 10 by 21 and 14 days, respectively. Only about 30% was released from xerogels with a molar ratio of 4 after 21 days of immersion. A first-order release stage was followed by a steady release stage for xerogels with molar ratios of 6 and 10, whereas zero-order release was observed for xerogels with a molar ratio of 4. The findings of this study indicate that the release kinetics of vancomycin from xerogel can be tailored by varying the xerogel synthesis parameters.
Creating and characterizing communities of human gut microbes in gnotobiotic mice

Microbiology labs are laden with flasks, plates, and freezer stocks containing axenic cultures and their products. In contrast, virtually every other habitat on Earth is filled with microbial communities of varying degrees of complexity. In this context, microorganisms are interdependent components of ecosystems; deciphering this dynamic requires a move from microbial organisms studied in isolation to model microbial communities studied under conditions that mimic those encountered by their members in their native habitats. Here we focus on model communities consisting of microbes that inhabit the human body habitat containing our largest collection of organisms – the gut. The adult human gastrointestinal tract is a microbial bioreactor, containing all three domains of life. This ecosystem is teeming with microorganisms at its distal end (1011-1012 cells/ml luminal contents in the colon) and less so at its proximal end (an estimated 103-104/ml luminal contents in the duodenum). The gut microbiota affects myriad aspects of our systems physiology, ranging from processing and harvesting of macro- and micronutrients (and xenobiotics!) from our diets, to shaping the features of our innate and adaptive immune system. Recently, deep sampling of the fecal microbial community has revealed that each of us harbors a collection of a several hundred bacterial phylotypes (Qin et al., 2010; Turnbaugh et al., 2010). The exact set of microbes differs from person to person although there is a greater degree of similarity between family members (Turnbaugh et al., 2009a; Turnbaugh et al., 2010). A catalogue of several million genes present in the fecal microbiome has been assembled (Qin et al., 2010) from analysis of a 577 Gbp dataset obtained from shotgun sequencing of fecal community DNA prepared from 124 Europeans and a 10.1 Gbp dataset generated from a set of deeply sampled obese monozygotic co-twins living in the USA. These datasets provide a starting point for making in silico predictions about functions that can be attributed to the gut microbiota. Measurements of expressed mRNAs (Turnbaugh et al., 2010), proteins (Verberkmoes et al., 2009) and metabolites (Hoverstad et al., 1984; Li et al., 2008; Martin et al., 2008) in fecal samples represent a first step towards testing these predictions.
All-or-Nothing Monitoring: Comment

Zhao (2008) presents an interesting "all-or-nothing monitoring" result for a multitask moral hazard agency problem with partial effort observation. We argue that the optimal contract based on the non-verifiable observation of the agent's effort in Zhao (2008) can be regarded as a limitation on the incentive schemes available to the principal. I then propose some arguably more appropriate approaches for analyzing such agency problems. (D82, D86, M54)
Influence of Neuromuscular Blocking Drugs on Recovery of Skeletal Electromyographic Activity in the Rat

Dose-related from muscular paralysis was examined in rats following a single intraperitoneal injection of one of three neuromuscular blockers: succinylcholine (SC), dimethyl d-tubocurarine iodide (DM), or d-tubocurarine chloride (dTC), Electromyographic (EMG) activity of the ipsilateral biceps femoris and biceps brachii muscles were sampled in each S. Time required to attain a predetermined percent integrated EMG activity, relative in a level established after drug stabilization, served as the major index of recovery. The results showed that the effect of SC and DM on regaining motor control is predictable on a mg/kg body weight basis. However, increasing the dose level of dTC produced no difference in the time required for the initial consistent signs of EMG recovery. Drug-dosage effects on recovery from paralysis could not be attributed to systematic changes in either basal heart rate or rectal temperature. The results are interpreted as supporting other reports of the unpredictable consequences of dTC-induced paralysis.
Dural arteriovenous fistulas associated with benign meningeal tumors.

Background Dural arteriovenous fistulas (dAVFs) are usually idiopathic lesions. While individual case reports have documented the occurrence of dAVFs in conjunction with benign meningeal tumors, a detailed characterization of this association is lacking. The objective of this study was to critically examine the relationship between benign meningeal tumors and dAVFs.
Synthesis and linear and nonlinear optical properties of metal-terminated bis(dioxaborine) polymethines

RhIII and IrIII can be complexed to bipyridine groups attached to the termini of bis(dioxaborine)-capped heptamethines; these chromophores exhibit large third-order polarisabilities at 1.55 μm, while retaining good film-forming properties and linear optical transparency in the near infrared.
The Histogram Optimization And Histogram Compression Segmentations

Two methods of segmentation called the Histogram Optimization Segmentation and the Histogram Compression Segmentation are presented. These algorithms use local histograms in a recursive manner to arrive at a self-consistent segmentation. The first two sections explain the specific operation of the algorithms and the last section examines the validity of one of the segmentation criteria. Examples of the segmentations are also given.
Validity of Using Accumulated Gas Pressure Readings to Measure Forage Digestion In Vitro: A Comparison Involving Three Forages

Gas output from in vitro digestion of forage can be used to measure both forage digestibility and the kinetics of microbial digestion. Two different approaches are used to measure gas volumes: 1) either the gas is collected at atmospheric pressure and its volume determined directly, or 2) the gas accumulates in a fixed volume container, and the volume is calculated from pressure changes. We have used the latter technique to study the in vitro digestion of alfalfa, timothy, and corn silage by ruminal microorganisms in bottles of different sizes. We measured pH changes, NDF disappearance, and VFA concentrations and characterized the digestion profiles using a single- or dual-pool logistic model. Bottle size had a slight effect on pH but was not associated with changes in any of the other characteristics measured including the kinetic parameters. Gas measurements based on pressure increases in a fixed volume container appear to offer a valid alternative to methods based on gas collection at atmospheric pressure. We present an equation to adjust pressure sensor calibration values for use in different sized containers.
Effect of beryllium on in vitro calcification of cartilage.

Summary1. Beryllium in concentrations of 1.0 × 10−5M or greater is a potent inhibitor of the dephosphorylating activity of cartilage alkaline phosphatase. 2. In concentrations of 10−5M or greater, beryllium completely blocked in vitro calcification of cartilage when phosphorus was supplied as β-glycerophosphate, phenylphosphate or creatine phosphate. 3. When phosphorus was supplied as inorganic phosphate (the condition apparently obtaining in vivo), concentrations of beryllium sufficient to produce marked inhibition of alkaline phosphatase failed to interfere with in vitro calcification of cartilage. 4. The significance of these findings in relation to current theories of endochondral calcification and “beryllium rickets” is discussed.
Warnings: Do They Make a Difference?

Four experiments Were conducted in order to determine Whether Warnings are effective and to identify factors that influence their effectiveness. Warnings were posted on a copy machine, a public telephone, a Water fountain, and two sets of doors. The first two warnings were effective in that most people did not use the copy machine and the telephone when they had the warnings on them. The warning on the water fountain was not effective when a single, small warning was used. When that warning plus a larger, more forceful warning was used, most people did not drink from the fountain. The warnings on the doors were not obeyed when a convenient alternative exit was not available. However, when the warning directed people to a nearby, convenient exit, most of them obeyed it. Warning with a low cost of compliance are apparently more effective. The results indicate that warnings can be effective, but not unless they are well designed in appearance and content.
Navigating the Academic Developmental Maze: New Possibilities for Mentoring International Graduate and Doctoral Students through the USA

As an increased number of international students join College and University classrooms across the United States, their transition and acclimation to campuses has received attention over the past few years, particularly, in the areas of preparation and acculturation. This topic is important because faculty mentors can play a pivotal role in the professional development of international doctoral students. This article addresses these needs with a model which integrates adult learning and mentoring strategies to support international doctoral students. The model includes developing the skills which not only international graduates, but all graduates will benefit from in the 21st century. The significance of this model is its contribution to develop the valuable capabilities of proactive, problem solving, self-directed learners/academics able to self-reflect and navigate different cultural environments than their own. The discussion also provides future research recommendations.
Evidence for nuclear spin symmetry states in solid silane

Abstract The existence of nuclear spin symmetry states associated with the protons and deuterons in solid silane is inferred from minima in a plot of nuclear spin-lattice relaxation times versus temperature.
Topic: Premature ventricular contractions and ventricular tachycardia

PARTICIPANTS : Abraham Lincoln School of Medicine, Chicago : Ira Dullrow; Baylor University, Houston : Arthur Garson, Paul C. Gillette; Duke University, Durham : D. Woodrow Benson; Children's Hospital of Philadelphia : Victoria Vetter; Cincinnati Children's Hospital : Winston Gaum; Columbia Presbyterian Medical Center, Babies Hospital, New York City : Allan J. Hordof, Carl N . Steeg; University of California, Los Angeles : Nigel Roberts ; University Hospital, Cleveland : Jerome Liebman; University of Miami, Miami: Otto Garcia, Henry Gelband, Ashok V. Mehta, Arthur S . Pickoff, Dolores Tamer, Grace S . Wolff; University of Michigan, Ann Arbor: MacDonald Dick, II; University of Nebraska, Omaha : John Kugler; University of Texas, Galveston : Alfonso Casta .
Application of 4D-Variational data assimilation to the California Current System

The Incremental Strong constraint 4D-Variational (IS4DVAR) data assimilation system of the Regional Ocean Model System (ROMS) is used to study the controllability of a realistic, high resolution configuration of the California Current System. The configuration and results of assimilating both satellite-derived surface observations along with in situ data are presented. Results show consequent improvements in many characteristics of the model circulation, and some of the strengths of the adjoint method for data assimilation are highlighted. General issues of the sensitivity of the results to the configuration of ROMS-IS4DVAR are also discussed.
Pilonidal sinus of the suprapubic region.

Summary: A case of suprapubic pilonidal sinus in a young female is presented and previously reported cases of this condition are reviewed.
Gravitation, Gauge Theories and Differential Geometry

Stanford Linear Accelerator Center, Stanford, California 94305, USA and The Enrico Fermi Institute and Department of Physics, The University of Chicago, Chicago, illinois, USA Peter B. GILKEY Fine Hall, Box 37. Department of Mathematics, Princeton University, Princeton, New Jersey 08544, USA and Department of Mathematics, University of Southern California, Los Angeles, California 90007, USA and Andrew J. HANSON
Preferential Feline Immunodeficiency Virus (FIV) Infection of CD4+ CD25+ T-Regulatory Cells Correlates both with Surface Expression of CXCR4 and Activation of FIV Long Terminal Repeat Binding Cellular Transcriptional Factors

Previously, we have characterized feline CD4 + CD25 + T-regulatory (Treg) cells with regard to their immune regulatory properties and ability to support feline immunodeficiency virus (FIV) replication in vitro and in vivo. Our studies showed that while CD4 + CD25 + cells were capable of replicating FIV in the presence of interleukin-2 (IL-2) alone, CD4 + CD25 − cells harbored a latent infection that required a strong mitogenic stimulus to activate virus replication. In the present study, we investigated the mechanisms governing the preferential replication of FIV in highly purified CD4 + CD25 + Treg cells compared to their CD4 + CD25 − counterparts. Studies aimed at elucidating mechanisms regulating infection of these cells revealed that CD4 + CD25 − cells were less susceptible to FIV binding and entry than CD4 + CD25 + cells, which correlated with increased surface expression of FIV coreceptor CXCR4. In addition, the number of CD4 + CD25 + cells that expressed the primary receptor CD134 was greater than for CD4 + CD25 − cells. Although increased permissiveness to FIV infection of CD4 + CD25 − cells following mitogenic stimulation correlated strongly with upregulation of surface CXCR4, it did not correlate with CD134 expression. Further, study of intracellular factors regulating FIV replication revealed that CD4 + CD25 + but not CD4 + CD25 − T cells showed constitutive and IL-2-responsive transactivation of activating transcription factor, CAAT enhancer binding protein, and activating protein 1 transcription factors that are important for FIV replication. These factors were upregulated in CD4 + CD25 − T cells following ConA stimulation, which correlated with FIV replication. This is the first report elucidating the mechanisms that allow for productive lentiviral infection of CD4 + CD25 + Treg cells.
The rate at which human sperm are immobilized and killed by mild acidity.

Abstract Objective: To determine the rate at which mild acidity immobilizes and kills human sperm and to evaluate an acidic microbicide, BufferGel, for sperm immobilization. Design: Controlled in vitro study. Setting: An academic research university and hospital andrology lab. Patient(s): Eight volunteer male sperm donors. Intervention(s): Semen samples were treated with hydrochloric acid (HCl) or BufferGel. Main Outcome Measure(s): Sperm motility was measured by using a computerized automated semen analyzer and video microscopy. Sperm membrane permeability and intracellular pH were measured by using fluorescent techniques. Result(s): In semen acidified with HCl to pH 4.0, sperm were rapidly immobilized (within 1 min) and were irreversibly immobilized (killed) within 10 minutes. The speed of immobilization and of killing were both linearly proportional to hydrogen ion activity over a pH range of 7.5–4.0. Across the same range, the intracellular pH of human sperm equilibrated to within 0.5 pH units of extracellular pH within 1–2 minutes. BufferGel immobilized sperm significantly faster than HCl from pH 4.0–6.0. Conclusion(s): Exposure to mild acidity rapidly acidifies the intracellular pH of human sperm and is rapidly spermicidal. BufferGel accelerates acid immobilization of sperm.
EQUILIBRIUM HOLDINGS DISTRIBUTIONS IN DURABLE ASSET MARKETS

Abstract The stock of durable goods can be represented by its holdings distribution , defined as the joint distribution of age and physical condition of the population of durable goods. This paper derives the holdings distribution which arises under stationary conditions when durable goods deteriorate according to a Markov process. We show that given the scrappage and utilization decisions of consumers, the holdings distribution F ( x ) is an equilibrium distribution of an associated regenerative Markov process. Using a basic result from the theory of regenerative stochastic processes, we characterize F ( x ) as the ratio of the expected number of periods the durable's condition is better than x to the expected lifetime of the asset. Using data from the 1977 National Transportation Survey we illustrate these results by estimating a simple two-parameter model of automobile deterioration and comparing the implied distribution of automobile holdings to the actual distribution.
Purification of an Endogenous Modulator for Voltage-Sensitive Calcium Channels Using the Eccentric Multi-Layer Coil Planet Centrifuge

Abstract High-speed countercurrent chromatography using a two-phase solvent system was found to be the method of choice for purifying an endogenous Ca2+ channel modulator. The solvent system composed of n-butanol, acetic acid and water (4:1:5) was most suitable for resolving the active material from other unknown substances of low molecular weight. Countercurrent chromatography proved useful in validating the presence in rat brain of an endogenous ligand for dihydropyridine-sensitive Ca2+ channels. Moreover, the degree of purity of the active material obtained by countercurrent chromatography is suitable for consecutive analysis by mass spectrometry or nuclear magnetic resonance.
Multi-Site Dependent Interaction of Hh Transcription Factor Gli3 with Cul3-SPOP Ubiquitin Ligase

Gli3, a largely intrinsically disordered protein, is a transcriptional factor in the Hedgehog (Hh) signaling pathway. It is regulated by a Cullin-3-RING ligase that targets Gli3 for ubiquitination and degradation through its substrate recognition subunit SPOP. SPOP contains a BTB dimerization domain and a MATH domain that recognizes its substrates through Ser/Thr rich motifs, termed SPOP binding consensus (SBC) motifs. Gli3 contains 13 predicted SBC motifs. The biophysical mechanism of the interaction between dimeric SPOP and multivalent Gli3 is not well understood. To deconvolute this complex interaction we use the MATH domain of SPOP, a full-length monomeric SPOP mutant, and the SPOP dimer to characterize their interactions with a Gli3 construct spanning the N-terminal 90 residues (Gli3-90) containing three SBC motifs. To investigate stoichiometry, sites of interaction, microscopic and macroscopic affinities, we have exploited various biophysical techniques including NMR spectroscopy, fluorescence anisotropy (FA), and analytical ultracentrifugation (AUC). NMR titration experiments reveal that the predicted SBC motifs in Gli3 interact with SPOP. AUC supports a binding model in which the MATH domain can interact with three binding motifs on Gli3-90 with macroscopic weak affinities while FA allows the determination of microscopic affinities. In vitro ubiquitination assays and protein stability studies in mammalian cells with a series of Gli3 SBC motif mutants are used for functional interpretation of our biophysical data. Each SBC motif contributes to SPOP binding in agreement with their similar weak affinities. These results will allow the distinction between a dynamic complex, a static multivalent binding mechanism and large oligomeric assemblies in which many Gli3s co-operate to recruit multiple SPOP dimers. The presence of multiple dispersed SBC motifs suggests their contribution to spatial and temporal control of Gli3 levels in response to Hh signaling.
Glutamate transporters: diversity, function, and involvement in neurologic disease.

AD= : Alzheimer disease; ALS= : amyotrophic lateral sclerosis; AQP4= : aquaporin 4; EAAT= : excitatory amino acid transporter; GABA= : γ-aminobutyric acid; PD= : Parkinson disease; SLC= : solute carrier family; SOD1= : superoxide dismutase 1; TNF= : tumor necrosis factor; VGLUT= : vesicular glutamate transporter. Glutamate is the major excitatory neurotransmitter in the mammalian CNS and is critically involved in mechanisms of synaptic plasticity, memory, and neuronal or glial cell death. Glutamate is stored in synaptic vesicles by the action of vesicular glutamate transporters (VGLUTs) and, following its release, exerts its effects via inotropic and metabotropic receptors. The synaptic effects of glutamate are rapidly terminated by action of glutamate transporters (excitatory amino acid transporters [EAATs]) located on the plasma membrane of astrocytes and neurons. These 2 transporter families differ in many of their functional properties. Studies in knockout mice and other experimental models have provided insights into the physiologic role of VGLUTs and EAATs in normal glutamatergic transmission and their potential role in neurologic disorders. Alterations in the function or expression of EAATs have been implicated in the pathophysiology of stroke, epilepsy, amyotrophic lateral sclerosis (ALS), Alzheimer disease (AD), Parkinson disease (PD), Huntington disease, HIV-associated dementia, malignant glioma, and other neurologic disorders. Loss of VGLUT has been reported in PD and AD. The physiology, regulation, and involvement of glutamate transporters in neurologic disease have been the subjects of several excellent reviews.1–10 ### Vesicular glutamate transporters. Glutamate is synthesized in the presynaptic terminals from glutamine by action of phosphate-activated glutaminase and is translocated into the lumen of presynaptic vesicles via VGLUTs3,5,6 (figure). VGLUT isoforms belong to the solute carrier family (SLC) SLC17 type I phosphate transporter family and are highly homologous, consisting of 12 putative transmembrane spanning domains. Glutamate uptake is driven by a proton (H+)-dependent electrochemical gradient across the vesicle membrane created by a vacuolar-type ATPase. Unlike other vesicular neurotransmitter transporters, the driving force for VGLUTs depends predominately on the existence of a vesicular membrane potential gradient, rather than a pH gradient. Figure Distribution and mechanisms of vesicular glutamate transporters (VGLUT) and excitatory amino acid transporters …
Multidisciplinary design optimization of lumbar transpedicular screws

Some of the complications associated with the use of transpedicular screws for spinal fusions include the large diameters of the screws and screw breakagein vivo. Recent advances in multidisciplinary design optimization techniques have provided a unique approach to incorporate the structural, biological, and manufacturing disciplines involved in the design process of spinal screws, allowing the development of smaller and safer transpedicular screws.
Bases for Coordinate Rings of Conjugacy Classes of Nilpotent Matrices

Abstract A general conjecture is given for an explicit basis of the coordinate ring of the closure of the conjugacy class of a nilpotent matrix. This conjecture is proven when the partition given by the transpose Jordan type of the nilpotent matrix is a hook or has two parts.
An analytical model for near-saturated pool boiling critical heat flux on vertical surfaces

Abstract Photographic studies of vertical pool boiling for near-saturated conditions were conducted in order to determine the critical heat flux (CHF) trigger mechanism. The studies revealed that, for heat fluxes near CHF, vertical pool boiling exhibits vapor behavior similar to that observed in flow boiling. At fluxes slightly below CHF, the Kelvin-Helmholtz instability creates a wavy layer at the liquid-vapor interface. The heater surface is wetted, and thus cooled, only by the wave troughs, referred to as wetting fronts, which repeatedly sweep across the surface. Prior to CHF, the curvature of the wetting front creates a pressure force which tends to preserve interfacial contact with the wall. Critical heat flux occurs when the pressure force due to interfacial curvature is overcome by the momentum of vapor at the site of the first wetting front, causing the interface to lift away from the wall. Once the first wetting front lifts off from the surface, the remaining wetting fronts separate from the surface in succession. It is shown that the interfacial lift-off criterion facilitates accurate theoretical modeling of CHF in vertical pool boiling, and produces an equation which is identical in form, but not mechanism, to traditional horizontal CHF models.
Some results on permutation group isomorphism and categoricity

We extend Morley's Theorem to show that if a theory is κ -p-categorical for some uncountable cardinal κ , it is uncountably categorical. We then discuss ω -p-categoricity and provide examples to show that similar extensions for the Baldwin-Lachlan and Lachlan Theorems are not possible.
High Stiffness Closed-Form Kinematic Structural Design of a Low-Cost 4/5-Axis Micro/Meso-Scale Inverted High-Speed Machining Center

The demand for miniaturized components is increasing in various industries, such as the biomedical, consumer electronics, optics and defense-related industries. The production of the micro/meso-scale components and parts in these industries is typically undertaken using MEMS-type photolithographic production techniques that have limitations in the materials and geometries that can be produced. However, numerous research efforts during the course of the last five to ten years have developed micro-scale EDM processes, micro-laser processes and micro-machining operations. In particular, the micro-machining processes have been demonstrated to provide a credible solution to the production of micro/mesoscale parts with complexes geometries in a broad range of materials. The development of mMTs is growing with the rapidly increasing demand for tighter tolerances. Traditionally, mMTs have been developed based on horizontal or vertical Cartesian co-ordinate machine tool structures. However, as the need for increased process flexibility and productivity is continuously being driven higher, there is a need to develop higher degree of freedom machining systems, including 4-axis and 5-axis machining centers. In this paper, the design of a low-cost, high-precision, high-speed 4/5-axis micro/meso machining center is presented as a cost-competitive alternative to existing open-form kinematics precision machining centers. A key departure from traditional machine tool design approach that has been adopted in this design is the utilization of closed-form kinematic structural design to create a high-stiffness, low-cost machine tool base. In addition, the lower thermal mass of the mMT base enhances rapid thermal washout in the structure and significantly reduces the thermal gradients in the structure. Consequently the thermal errors present in the structure are limited and simply and adequately handled using existing error compensation strategies. Initial results from an analytical and numerical investigation of the thermo-mechanical response of an innovative, kinematically closed-form inverted micro-machining center are presented. A coarse resolution parametric study was undertaken to evaluate the preferred preferred design space for maximum stiffness and minimum thermal distortion in low-cost, high precision, high-speed micro-machining centers. In addition, in order to facilitate part loading and unloading operations will be considered as a key design characteristic. A key result of this study has been the identification of a preferred design space for kinematic form selection, material selection and structural design options for increased rigidity, reduced thermal error and reduced production costs for flexible 4/5-axis micro/meso-scale machining centers. The proposed mMT design achieves a 3X increase in rigidity over a comparable tradition kinematically open horizontal mMT system.© 2008 ASME
Computer programs for the solution of systems of linear algebraic equations

FORTRAN subprograms for the solution of systems of linear algebraic equations are evaluated and compared on the basis of execution speed and accuracy. A symmetric, positive definite, banded test matrix is used in each case. The procedures considered are direct solution, iteration and matrix inversion. Both in-core schemes and those requiring the use of auxiliary data storage devices are included. Some of the techniques used require the full coefficient matrix, whereas others account for symmetry, banding, or sparseness of the system. Matrix inversion is found to be an inefficient technique, even if multiple right-hand side constant vectors are to be solved. In such cases, either Gauss elimination with multiple constant vectors treated simultaneously, or decomposition with the retention of the upper and lower triangular matrices, is recommended. Double precision arithmetic is suggested as a means of reducing round-off errors, and should always be employed when permitted by the computer's core capacity. On the basis of the results obtained with the single test system of equations, specific subprograms are recommended for each category of problem.
A placebo-controlled, double-blind trial of the long-term effects of albuterol administration in patients with cystic fibrosis.

This placebo-controlled study was designed to confirm a previously performed open label study that showed significant improvement in spirometry on maintenance therapy with albuterol for 1 year. In a double-blind, cross-over trial, albuterol (by metered dose inhaler) 180 μg b.i.d. or placebo were given for 6 months each. Spirometry was monitored at the start, and 3 and 6 months following initiation of each arm of the study. Peak expiratory flow rate (PEFR) was measured twice daily at home before and after study drug administration. Only patients with clinically detectable lung disease were enrolled. Twenty-one patients finished the study. All spirometric tests showed a significant improvement from start to end of the 6 month treatment with albuterol; there was no significant change on placebo. Forced vital capacity improved by 8.2% and forced expiratory volume in 1 s by 12.1% on albuterol therapy. Nevertheless, there was no significant difference between change on albuterol and change on placebo. Home measurements of PEFR showed a significant improvement of 4.7% on albuterol and a non-significant change of 2.0% on placebo from the first to the last week of treatment. None of the long-term improvements (spirometry or home PEFR) correlated with mean daily bronchodilation. For albuterol, the number of days of hospitalization was less than half that for patients on placebo (1.0/patient on albuterol versus 2.6 on placebo), but this did not reach statistical significance. These results suggest a beneficial effect from maintenance therapy with albuterol. Bronchodilation alone probably cannot explain the long-term benefits of albuterol, and other mechanisms may play a role. The lack of significant difference between change on albuterol and change on placebo is probably due to too small a number of patients in this study and lack of statistical power. Pediatr. Pulmonol. 1998; 25:32–37. © 1998 Wiley-Liss, Inc.
HRSD5 predicts patient outcome as early as 12 hours: Utility of dense physiologic data captured in 1316 trauma patients

Abstract Introduction. Our previous work demonstrated Dense Physiologic Data Capture ( DPDC ) in the ICU, defined a new vital sign Cardiac Volatility Related Dysfunction ( CVRD ) , and demonstrated CVRD predicts death during the hospital stay adjusting for age and injury severity score (ISS). We hypothesized that a more precise statistical definition of CVRD improves predictive power earlier in ICU stay, without adjusting for covariates. Methods. Approximately 120 million heart rate (HR) data points were prospectively collected and archived from 1316 trauma ICU patients, linked to TRACS outcome data, and de-identified. HR standard deviation was computed in each 5-min interval (HR SD5 ). HR SD5 logistic regression (MATLAB) identified ranges predictive of death. The study group was randomly divided. CVRD (% time HR SD5 in predictive distribution ranges) models were developed on the first set ( N = 658) at 1, 2, 4, 6, 12, and 24 h and validated ( N = 658). Results. HR SD5 is bimodal, predicts death at low (0.3–0.6), and survival at high (2.1–2.2) ranges (Fig. 1). CVRD predicts trauma patient death as early as 12 h (Fig. 2). CVRD in a moving 1-h window is a simple graphic display technique (Fig. 3). Conclusions. DPDC allows calculation of Cardiac Volatility Related Dysfunction which (1) Independently predicts hospital death in trauma patients at 12 h (optimized at HR SD5 0.4–0.6); (2) Shows evolving differences by survival when viewed in a moving window; (3) May have implications for military and civilian triage. Download full-size image
Targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation: a case study

Summary Background The function of current artificial arms is limited by inadequate control methods. We developed a technique that used nerve transfers to muscle to develop new electromyogram control signals and nerve transfers to skin, to provide a pathway for cutaneous sensory feedback to the missing hand. Methods We did targeted reinnervation surgery on a woman with a left arm amputation at the humeral neck. The ulnar, median, musculocutaneous, and distal radial nerves were transferred to separate segments of her pectoral and serratus muscles. Two sensory nerves were cut and the distal ends were anastomosed to the ulnar and median nerves. After full recovery the patient was fit with a new prosthesis using the additional targeted muscle reinnervation sites. Functional testing was done and sensation in the reinnervated skin was quantified. Findings The patient described the control as intuitive; she thought about using her hand or elbow and the prosthesis responded appropriately. Functional testing showed substantial improvement: mean scores in the blocks and box test increased from 4·0 (SD 1·0) with the conventional prosthesis to 15·6 (1·5) with the new prosthesis. Assessment of Motor and Process Skills test scores increased from 0·30 to 1·98 for motor skills and from 0·90 to 1·98 for process skills. The denervated anterior chest skin was reinnervated by both the ulnar and median nerves; the patient felt that her hand was being touched when this chest skin was touched, with near-normal thresholds in all sensory modalities. Interpretation Targeted reinnervation improved prosthetic function and ease of use in this patient. Targeted sensory reinnervation provides a potential pathway for meaningful sensory feedback.
Collective memory support in negotiation: a theoretical framework

Negotiation analysis is complex. It may involve multiple issues of dispute, rules of negotiation, negotiators' strategies, interventions by third party, negotiators' cognitions, beliefs, preferences and attitude towards risks. Negotiators may have limited attention, limited capacity to store and retrieve memory information and limited capacity to process information. As a result they rely on heuristics or schemas and fail to generate optimal outcomes in negotiation. An approach to overcome cognitive limitation in negotiation is to provide additional support to store and retrieve memory information. This paper reiterates the conceptual framework of a computer supported negotiation memory support system (NMSS) and proposes a theoretical model of the influence of NMSS on negotiation outcome.
Temporal Effects of Stress by Immobilization and Sensitivity of the Isolated Rat Pacemaker to Isoproterenol: Roles of Corticosterone, Neuronal Uptake, and β-Adrenergic Homogeneity

A number of diseases and pathological conditions are related to the long-term adaptive response to stress, in particular under conditions of chronic stress when allostasis can shift from a healthy toward a pathological state. Although a vast number of studies have focused on the effects of chronic stress on brain and the immune system, fewer studies have been performed in peripheral tissues. Here, we used the intact isolated right atrium (pacemaker) from the rat to investigate the temporal effects of stress induced by immobilization (restraint stress) on the sensitivity of the pacemaker to the chronotropic response to isoproterenol (i.e., the effect of isoproterenol to increase the frequency of contractions of pacemakers). Immobilization sessions were conducted a specific number of times (1, 3, 7, 9, 11, and 14). We found that the response to stress over time approximates a Gaussian distribution (i.e., normal standard distribution) with no significant effects being detected after either 1 or 14 immobilization sessions, whereas supersensitivity to the chronotropic effect of isoproterenol occurred after 3, 7, 9, and 11 immobilization sessions, with a peak effect occurring after seven immobilization sessions. At a cellular level, we determined that both corticosterone and neuronal uptake of catecholamines were directly involved with the observed effects, whereas no alterations in the homogeneity of β-adrenoceptors were detected in pacemakers of stressed animals. We hypothesize that these adaptations are essentially beneficial in nature, as they should allow the animals to more promptly respond to the demands imposed by the stressful conditions.
Low cost AC power monitor for residential PV support

The rate at which new, residential on-grid PV systems are being installed increases every year. Yet, most include virtually no metering, customer education or other support for the system owners. The California Energy Commission's Renewable Energy Program Evaluation, October 2000, stated that consumers need a basic level of system performance measurement in order to verify whether their system is operating properly. This echoes a recurring observation that has been made by researchers, at least, since 1990. Consumers can turn to after-market meters which exist, but these are often inaccurate and none supports remote display. Of equal concern is that manufacturers of most meters assume a basic knowledge of electrical power that homeowners do not possess. To help meet this longstanding need, an inexpensive, accurate, AC power monitor has been developed for installation by an untrained homeowner. This monitor incorporates a power line carrier remote display that can be located anywhere in the home. The monitor and associated training materials have been designed to teach consumers to accurately assess PV system performance and recognize system failures. It is hoped that the unit's low cost and potential consumer value demonstrate its commercial viability.
Native American DNA: Ethical, Legal, and Social Implications of an Evolving Concept

This review examines the emerging concept of “Native American DNA” utilized by genetic scientists and anthropologists to denote a connection via nucleotide bases between ancient and contemporary peoples of the Americas. This concept is problematic on conceptual and practical levels; this review highlights its use in various disciplines, focusing on ongoing disputes about its meaning and applicability and concluding with a call to attention for all who utilize such concepts. The ethical, legal, and social implications of Native American DNA have to be taken into account because the label itself is still under construction: Contemporary Native American peoples should not be confounded with the past or ancestral remains, but instead must actively be brought into research conversations at all stages.
A PC environment for discrete component digital design

A description is given of the implementation, operational experience and ongoing refinement of a computer-aided design tool for discrete component digital design in the department of electrical and computer engineering at the Air Force Institution of Technology. Specifically, a graphical user interface, simulation, and artificial intelligence technology are used to aid in the design of digital logic circuits. This is being incorporated into a first-quarter course to provide students with exposure to modern design techniques. The implementation and enhancements of a prototype design for an engineering workstation are described in detail. >
Attenuation effects of MR headphones during brain PET/MR studies

PET/MR offers potential advantages over PET/CT that are currently under investigation. One of the challenges of PET/MR is attenuation correction, as there is no simple correlation between MR signal intensity and the attenuation of 511-keV photons detected in PET. Currently, dedicated MR sequences are used to segment voxels into categories that are then assigned a predetermined attenuation coefficient. MR hardware such as the imaging table, coils, and headphones are also sources of attenuation. The purpose of this study was to evaluate the effect of MR-compatible headphones on average activity concentration measured with PET/MR. We also present a practical approach to correct for the attenuation effect of headphones using a CTderived attenuation map. Methods: Phantom studies were performed using a 3-L cylindric phantom containing 55 MBq of 18 F-FDG and water. Images were acquired on a PET/MR device in 2 settings—one with the PET/MR headphones on and one with the headphones off. Phantom images were analyzed to compare activity concentration with headphones on and off. A high-resolution CT and 57Co transmission scan was obtained to construct a PET attenuation map of the headphones. The resulting attenuation map was registered to the phantom data to evaluate the ability to correct for headphone attenuation. One human subject was scanned to evaluate the clinical impact of headphone attenuation and the accuracy of the proposed correction. Results: Activity concentrations measured in the phantom were reduced by as much as 13.2% with headphones on compared with headphones off. Using the modified attenuation maps that account for attenuation from the headphones resulted in a decrease in the headphone attenuation effect from a maximum of 13.2% to 1.9%. Comparable attenuation effects were observed in the human brain and were similarly reduced with correction using the modified attenuation maps. Conclusion: MR-safe headphones were a source of attenuation on our PET/MR phantom and human studies. Attenuation effects of headphones should be considered and can be corrected during quantitative brain PET/MR studies.
Finite-Element-Based Computationally Efficient Scalable Electric Machine Model Suitable for Electrified Powertrain Simulation and Optimization

Electric machines are a key component of electric/hybrid electric vehicle (EV/HEV) powertrains. Thus, computationally efficient models for electric machines are essential for powertrain-level design, simulation, and optimization. In this paper, a finite-element-based method for quickly generating torque–speed curves and efficiency maps for electric machines is presented. First, magnetostatic finite-element analysis (FEA) is conducted on a “base” machine design. This analysis produces torque, normalized losses, flux linkage, and the maximum magnetic field intensity in the permanent magnets for a wide range of current magnitudes and phase angles. These values are then scaled based upon changing the size of the machine and the effective number of turns of the machine windings to quickly generate a variety of new machine designs and their corresponding efficiency maps using postprocessing techniques. Results suggest that, by avoiding resolving the FEA for the scaled designs, the proposed techniques can be used to quickly generate efficiency maps, and thus are useful for EV/HEV powertrain-level simulation and optimization.
Simultaneous functional photoacoustic and ultrasonic endoscopy of internal organs in vivo

At present, clinicians routinely apply ultrasound endoscopy in a variety of interventional procedures that provide treatment solutions for diseased organs. Ultrasound endoscopy not only produces high-resolution images, but also is safe for clinical use and broadly applicable. However, for soft tissue imaging, its mechanical wave-based image contrast fundamentally limits its ability to provide physiologically specific functional information. By contrast, photoacoustic endoscopy possesses a unique combination of functional optical contrast and high spatial resolution at clinically relevant depths, ideal for imaging soft tissues. With these attributes, photoacoustic endoscopy can overcome the current limitations of ultrasound endoscopy. Moreover, the benefits of photoacoustic imaging do not come at the expense of existing ultrasound functions; photoacoustic endoscopy systems are inherently compatible with ultrasound imaging, thereby enabling multimodality imaging with complementary contrast. Here we present simultaneous photoacoustic and ultrasonic dual-mode endoscopy and show its ability to image internal organs in vivo, thus illustrating its potential clinical application.
Predicting Outcomes in Locally-Advanced Rectal Cancer Using Pretreatment FDG-PET Imaging.

495 Background: FDG-PET/CT imaging has been shown to have clinical utility in the management of rectal cancers. The purpose of this study was to investigate multiple FDG-PET/CT parameters to predic...
Capacity of the Trapdoor Channel With Feedback

We establish that the feedback capacity of the trapdoor channel is the logarithm of the golden ratio and provide a simple communication scheme that achieves capacity. As part of the analysis, we formulate a class of dynamic programs that characterize capacities of unifilar finite-state channels. The trapdoor channel is an instance that admits a simple closed-form solution.