cssi/SciSciGPT-SciSciNet huggingface dataset:
Steady flow of a viscous ice stream across a no-slip/free-slip transition at the bed

An exact, analytic description of the steady, downhill flow of a viscous ice stream across a no-slip to free-slip transition in basal boundary condition suggests ways in which such transitions might be detected by observations of ice-stream surface properties. We find that the best expression of this transition is in the free-surface profile, which dips over the point of transition and becomes horizontal far downstream. The streamwise velocity at the surface shows a gradual change across the transition, and this is in disagreement with previous studies which suggest a marked change. Basal shear stress and basal pressure exhibit singularities at the point of transition. As concluded in previous study, the former singularity is a likely point of strong basal erosion. The latter singularity is problematical, however, because it violates the assumptions which make the exact solution possible. It is not clear how this problem can be overcome without appealing to thermodynamics, non-Newtonian material properties, cavitation or wake separation.
RAPID HYPOTHERMIC CARDIOPLEGIA AND AIR VENTING WITH AN AORTIC ROOT CANNULA.

Abstract A newly designed aortic root perfusion cannula (ARC) is described that accomplishes a double purpose. Not only does it allow rapid inflow into the root of the aorta for induction of hypothermic cardioplegia, but it also provides an effective air vent after completion of the procedure. This technique simplifies air venting at the end of open heart operations.
A Second-Generation Neurosecretionist Looks at His Field

This highly personal essay will attempt to outline the development of what I can only call a “second-generation” neurosecretionist. My entree into the field of neurosecretion began at a time when the fundamental concepts had been soundly established, not only by the recurring discovery of stainable secretory-appearing neurons in representatives of one animal group after another but also by the delineation of the neurosecretory pathway—the obligatory connection of these stainable neurons with a tract that led to a neurohemal organ wherefrom the products of these cells could be released.
Inequality, Decisions, and Altruism

We argue that sociological analyses of inequality could benefit from engaging the literatures on decision-making. In turn, a sociological focus on how contexts and structural constraints influence the outcomes of decisions and the strategies social groups can use in pursuit of their goals could inform our understanding of decision-making. We consider a simple two-class model of income and the need of capitalists and workers to mobilize resources to influence the adaptive landscape that shapes responses to decisions. We then examine the implications of the rational actor model and the heuristics and biases literature for class-based decision-making. We consider the importance of altruism in mobilizing collective action, and we offer some evidence that altruism is most common in the middle ranges of income and that altruism is a major influence on support for redistributive policies. These results, while tentative, suggest the value of having scholars of development and inequality engage with the literatures on decision-making.
Traffic congestion control for Aw–Rascle–Zhang model

Abstract This paper develops boundary feedback control laws to reduce stop-and-go oscillations in congested traffic. The macroscopic traffic dynamics are governed by Aw–Rascle–Zhang (ARZ) model, consisting of second-order nonlinear partial differential equations (PDEs). A criterion to distinguish free and congested regimes for the ARZ traffic model leads to the study of hetero-directional hyperbolic PDE model of congested traffic regime. To stabilize the oscillations of traffic density and speed in a freeway segment, a boundary input through ramp metering is considered. We discuss the stabilization problem for freeway segments respectively, upstream and downstream of the ramp. For the more challenging upstream control problem, our full-state feedback control law employs a backstepping transformation. Both collocated and anti-collocated boundary observers are designed. The exponential stability in L 2 sense and finite time convergence to equilibrium are achieved and validated with simulation. In the absence of relaxation time and boundary parameters’ knowledge, we propose adaptive output feedback control design. Control is applied at outlet and the measurement is taken from inlet of the freeway segment. We use the backstepping method to obtain an observer canonical form in which unknown parameters multiply with measured output. A parametric model based on this form is derived and gradient-based parameter estimators are designed. An explicit state observer involving the delayed values of the input and the output is introduced for state estimation. Using the parameter and state estimates, we develop an adaptive output feedback control law which achieves convergence to the steady regulation in the L 2 sense.
Lipids lead the way

Autophagy is a ‘self-eating’ recycling process that maintains cellular homeostasis. Autogramins were identified as small-molecule autophagy inhibitors that target the cholesterol transport protein GRAMD1A, revealing a role for cholesterol in autophagosome biogenesis.
The Sentinel Effect and Financial Reporting Aggressiveness in the Healthcare Industry

SYNOPSIS The sentinel effect posits that the perception of increased oversight is associated with improved behavior. We consider the association between enhanced government oversight and financial ...
Acute and long-term manganese exposure and subsequent accumulation in relation to idiopathic blindness in the American lobster, Homarus americanus

Abstract Manganese (Mn) is a hypoxic reactive metal commonly found in marine sediments. Under hypoxic conditions the metal becomes fully reduced to Mn2+ and is biologically available to the benthic community for uptake. Mn is also a potent neurotoxin and it may play a role in the etiology of idiopathic blindness that has been observed in American lobsters. An acute exposure study was designed to expose American lobster, Homarus americanus, to 0, 20, 80, 150, and 300 mg L−1 (ppm) for 96 hs to explore disparities in Mn accumulation among several tissues: optic nerve, brain, hepatopancreas, muscle, hemolymph, gill, and exoskeleton. These concentrations were based on realistic pore-water concentrations (20 mg L−1), high sediment concentrations (80 mg L−1), and unrealistically high concentrations to determine lethality (150 and 300 mg L−1). A positive correlation between Mn accumulation and exposure concentration was observed in all tissues examined. In the internal tissues, manganese concentrations showed a high affinity towards brain, optic nerve, and hemolymph. In the exoskeleton and gills, Mn concentrations were also high, possibly because of internal uptake as well as external adsorption. Concentrations of Mn in tissues from the acute exposure study followed the accumulation pattern: hemolymph > gill > exoskeleton > optic nerve > brain > hepatopancreas = muscle. A long-term exposure study lasting seven weeks was designed to investigate the potential link between high Mn exposure and idiopathic blindness, a condition that affects an estimated 50 % of the adult American lobster population off Southern New England (SNE), USA. A comparison of these exposure studies showed evidence of time-dependent Mn accumulation in brain, muscle, exoskeleton, and gill tissue. Although the relationship between Mn exposure and blindness was not apparent, there was a modest trend in the development of blindness (Chi-square, p = 0.102) in animals exposed to a high concentration (150 mg L−1) of the metal. With no mortalities occurring in the acute study and only one mortality in the long-term study, it is highly unlikely that Mn is acutely toxic to American lobsters at environmentally relevant concentrations. Its potential role in idiopathic blindness remains to be determined.
Using sample-based time series data for automated diagnosis of scalability losses in parallel programs

The performance of many parallel applications has failed to scale as fast as successive generations of hardware on which these applications execute. To understand the cause of scalability losses, experts use performance tools to monitor and analyze application behavior. Profiles generated by performance tools can usually indicate the presence of scalability losses while time series data are generally necessary to pinpoint the root causes of such losses. However, manual analysis of time series data can be difficult in executions with a large number of processes, long running times, and deep call chains. This paper describes an automated framework that analyzes sample-based time series data to diagnose scalability losses in parallel executions. The framework's automated diagnosis of scalability losses indicates their symptoms, severity, and causes. Two case studies illustrate the effectiveness of this framework. When compared to a tool that analyzes performance using instrumentation-based traces, our overhead for collecting sample-based time series is 1/28 in time and 1/1600 in space while our automated analysis takes 1/25 of the time.
Missense SNP rs3731249 Explains the CDKN2A Association with Childhood ALL and Shows Risk Allele Selection in Tumors with Somatic CDKN2A Alterations

Abstract Little is known about the interaction between constitutive and somatic genetic variation in carcinogenesis. Genome-wide association studies (GWAS) of childhood acute lymphoblastic leukemia (ALL) have identified 6 genetic associations, including the single nucleotide polymorphism (SNP) rs3731217, located between the CDKN2A and CDKN2B genes. Somatic deletions of this chromosome 9p21.3 region are common in cancer, and occur in ~30% of childhood ALL. We replicated the rs3731217 association with childhood ALL in Hispanics (P = 0.021) via a GWAS of 323 childhood ALL cases and 454 controls, using the Illumina OmniExpress SNP array. SNP imputation analysis across chromosome 9p21.3 revealed a stronger association at SNP rs3731249 (P = 6.4x10-4; OR = 2.77), a low-frequency missense variant in exon 2 (p.Ala148Thr) of CDKN2A (MAFcontrols = 2.1%). These associations were replicated in an additional 378 ALL cases and 536 controls using Taqman assays, where the missense variant again had a greater magnitude of effect (Prs3731249 = 6.5x10-3; ORrs3731249 = 2.00 versus Prs3731217 = 0.029; ORrs3731217= 1.38). We assessed the effect of rs3731249 on risk of other cancers with known chr9p21.3 GWAS associations, but observed no association between this variant and either adult glioblastoma or melanoma risk, suggesting an ALL-specific role for rs3731249. We hypothesized that cases heterozygous for rs3731249 may show allelic imbalance, with preferential loss of the wildtype (WT) allele when hemizygous chr9p21.3 deletions occur in leukemic cells. To test this, we developed a novel method termed “SMART-ddPCR” (Somatic Mutation Allelic Ratio Test using Droplet Digital PCR). Concentration of risk and WT alleles was measured by ddPCR using the rs3731249 Taqman assay in diagnostic bone marrow (i.e. tumor) DNA from 35 known heterozygotes. Allelic imbalance due to somatic CDKN2A alterations was identified in 17 cases, of which 14 had a higher risk:WT allele ratio (P = 0.006, 1-sided binomial significance test), thus demonstrating preferential loss of WT rs3731249 and retention of the missense allele. Subclonal heterogeneity in CDKN2A copy number was also evident, suggesting that CDKN2A alterations are secondary events in leukemogenesis. Preferential allelic imbalance towards the rs3731249 risk allele in ALL tumor DNA provides strong evidence of an important role for this missense variant in leukemogenesis. We show, for the first time, a direct relationship between constitutive and somatic genetic variants underlying ALL development, suggesting that such constitutive variants can provide an additional substrate for selection during tumor evolution. Disclosures No relevant conflicts of interest to declare.
Photonic Integrated Circuits for Precision Spectroscopy

A dual-laser indium phosphide photonic integrated circuit for precision spectroscopy lidar was designed and fabricated. A stabilization experiment demonstrated a twentyfold improvement in the long-term frequency stability of the master laser.
COVID-19 Pneumonia in Patients on Chronic Hydroxychloroquine Therapy: Three Cases of COVID-19 Pneumonia

Hydroxychloroquine has gained popularity as a potential preventative and treatment of COVID-19 pneumonia due to its in vitro activity against the virus. These three cases of COVID-19 pneumonia of varying severities occurred in the setting of chronic hydroxychloroquine use. These cases argue against the use of hydroxychloroquine as a preventative or therapeutic option for COVID-19 pneumonia.
Interfacing photonic crystal fiber with a metallic nanoantenna for enhanced light nanofocusing

The direct interfacing of photonic crystal fiber to a metallic nanoantenna has widespread application in nanoscale imaging, optical lithography, nanoscale lasers, quantum communication, in vivo sensing, and medical surgery. We report on the fabrication of a needle-shaped plasmonic nanoantenna on the end facet of a photonic crystal fiber using electron-beam-induced evaporation of platinum. We demonstrate the coupling of light from the fiber waveguide mode to the subwavelength nanoantenna plasmonic mode focusing down to the apex of the plasmonic needle using a polarization-resolved far-field side-scatter imaging technique. Our work provides an important step toward widespread application of optical fibers in nearfield spectroscopic techniques such as tip-enhanced Raman and fluorescence microscopy, single-photon excitation and quantum sensors, nanoscale optical lithography, and lab-on-fiber devices.
COMMUNICATION IN AI-ASSISTED TEAMS DURING AN INTERDISCIPLINARY DRONE DESIGN PROBLEM

Human-artificial intelligent (AI) - assisted teaming is becoming a strategy for coalescing the complementary strengths of humans and computers to solve difficult tasks. Yet, there is still much to learn regarding how the integration of humans with AI agents into a team affects human behavior. Accordingly, this work begins to inform this research gap by focusing specifically on how the communication structure and interaction changes within AI-assisted human teams. The underlying discourse data for this work originates from a prior research study in which teams solve an interdisciplinary drone design and path-planning problem. Several metrics are employed in this work to study team discourse, including count, diversity, content richness, and semantic coherence. Results show significant differences in communication behavior in AI-assisted teams including more diversity and frequency in communication, more exchange of information regarding principal design parameters and problem-solving strategies, and more cohesion. Overall, this work takes meaningful steps towards understanding the effects of AI agents on human behavior in teams, critical for fully building effective human-AI hybrid teams in the future.
How effective is extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest? A systematic review and meta-analysis.

Abstract Background Extracorporeal cardiopulmonary resuscitation (ECPR) has gained increasing as a promising but resource-intensive intervention for out-of-hospital cardiac arrest (OHCA). There is little data to quantify the impact of this intervention and the patients likely to benefit from its use. We conducted a meta-analysis of the literature to assess the survival benefit associated with ECPR for OHCA. Methods We searched PubMed, Embase, and Scopus databases to identify relevant observational studies and randomized control trials. We used the Newcastle-Ottawa Scale and Cochrane risk-of-bias tool to assess studies' quality. We performed random-effects meta-analysis for the primary outcome of survival to hospital discharge and used meta-regressions to assess heterogeneity. Results We identified 1287 articles, reviewed the full text of 209 and included 44 in our meta-analysis. Our analysis included 3097 patients with OHCA. Patients' mean age was 52, 79% were male, and 60% had primary ventricular fibrillation/ventricular tachycardia arrest. We identified a survival-to-discharge rate of 24%; 18% survived with favorable neurologic function. 30- and 90-days survival rates were both around 18%. The majority of included articles were high quality studies. Conclusions Extracorporeal cardiopulmonary resuscitation is a promising but resource-intensive intervention that may increase rates of survival to hospital discharge among patients who experience OHCA.
Small Vibrations of Uniformly Compressed Isotropic Elastic Solids

The effect of uniform external pressure on the small amplitude vibration frequencies of solid isotropic elastic bodies is examined herein. Variation with pressure of small amplitude vibration frequencies of a solid sphere is presented and specific results are obtained for strain energy function similar to that used in small deformation elasticity theory.
Lattice-Theoretic Approach to Projective and Affine Geometry

Publisher Summary A lattice is defined as a partially ordered set in which any two elements have a least upper bound and a greatest lower bound. In any complete lattice there exist a zero element “0” and a unit element “1” such that 0 ≤ x ≤ 1 for every lattice element x. The chapter considers lattices that are not distributive. The applications of lattice theory to the axiomatization of geometry yields radically different and simple characterizations of the geometries considered. Modular lattices can be regarded as a generalization of projective geometry. It is more reasonable to consider only complemented modular lattices because every projective lattice is complemented.. In context to lattice-theoretic approach, the chapter discusses results of projective and affine geometry and their generalizations.
The Epidemiology of Liver Diseases Unique to Pregnancy in a US Community: A Population-Based Study

Background & Aims Little is known in the United States about the epidemiology of liver diseases that develop only during (are unique to) pregnancy. We investigated the incidence of liver diseases unique to pregnancy in Olmsted County, Minnesota, and long-term maternal and fetal outcomes. Methods We identified 247 women with liver diseases unique to pregnancy from 1996 through 2010 using the Rochester Epidemiology Project database. The crude incidence rate was calculated by the number of liver disease cases divided by 35,101 pregnancies. Results Of pregnant women with liver diseases, 134 had preeclampsia with liver dysfunction, 72 had hemolysis-associated increased levels of liver enzymes and low-platelet (HELLP) syndrome, 26 had intrahepatic cholestasis of pregnancy, 14 had hyperemesis gravidarum with abnormal liver enzymes, and 1 had acute fatty liver of pregnancy. The crude incidence of liver diseases unique to pregnancy was 0.77%. Outcomes were worse among women with HELLP or preeclampsia than the other disorders—of women with HELLP, 70% had a premature delivery, 4% had abruptio placentae, 3% had acute kidney injury, and 3% had infant death. Of women with preeclampsia, 56.0% had a premature delivery, 4% had abruptio placentae, 3% had acute kidney injury, and 0.7% had infant death. After 7 median years of follow-up (range, 0–18 years), 14% of the women developed recurrent liver disease unique to pregnancy; the proportions were highest in women with initial hyperemesis gravidarum (36%) or intrahepatic cholestasis of pregnancy (35%). Women with preeclampsia were more likely to develop subsequent hepatobiliary diseases. Conclusions We found the incidence of liver disease unique to pregnancy in Olmsted County, Minnesota, to be lower than that reported from Europe or US tertiary referral centers. Maternal and fetal outcomes in Olmsted County were better than those reported from other studies, but fetal mortality was still high (0.7%–3.0%). Women with preeclampsia or HELLP are at higher risk for peripartum complications and subsequent development of comorbidities.
An extension of Luenberger observer-based H/sub /spl infin// compensators

This paper presents an algorithmic procedure of designing Luenberger observer based H/sub /spl infin// compensators for control systems with a nonzero D/sub 1/1 term. The design procedure involves the solution of two Riccati equations which are only one-way coupled.
On the conversion of 1-glutamate to 1-dopa

Abstract The title diene was prepared by the enol silylation of 1-methoxy-2-acetoxybut-1-ene-3-one. It undergoes Diels-Alder cycloaddition with a variety of dienophiles. Through such cycloaddition ther is provided acess to regiospecifically monoderivatized diosphenols and catechols. Cycloaddition of the title compound with dienophile (28), derived from L -glutamate, provides a route to optically pure L -Dopa.
Controlling the density of the two-dimensional electron gas at the SrTiO 3 /LaAlO 3 interface

The polar discontinuity at the SrTiO${}_{3}$/LaAlO${}_{3}$ interface (STO/LAO) can in principle sustain an electron density of $3.3\ifmmode\times\else\texttimes\fi{}{10}^{14}$ cm${}^{\ensuremath{-}2}$ (0.5 electrons per unit cell). However, experimentally observed densities are more than an order of magnitude lower. Using a combination of first-principles and Schr\"odinger-Poisson simulations we show that the problem lies in the asymmetric nature of the structure, i.e., the inability to form a second LAO/STO interface that is a mirror image of the first, or to fully passivate the LAO surface. Our insights apply to oxide interfaces in general, explaining for instance why the SrTiO${}_{3}$/GdTiO${}_{3}$ interface has been found to exhibit the full density of $3.3\ifmmode\times\else\texttimes\fi{}{10}^{14}$ cm${}^{\ensuremath{-}2}$.
Structure‐Function Relationships of Growth Hormone and Other Members of the Growth Hormone Gene Family

The sections in this article are: 1 Studies Using Growth Hormone Fragments 2 Multiple Activities of Growth Hormone 3 Crystal Structure 4 Studies Regarding Disulfide Bonds 5 Homologue/Alanine Scanning as A Means of Defining Biologically Active Domains 6 The Third α-Helix 6.1 Mutagenesis of the Growth Hormone Gene Encoding α-Helix 3 and Transgenic Mouse Studies 6.2 Importance of the Amphiphilicity of the Third α-Helix 6.3 Designing a Growth Hormone Analogue with a Perfect Amphiphilic α-Helix 6.4 Systematic Substitution Mutations in the Hydrophilic Region of the Third α-Helix of Bovine Growth Hormone 7 Growth Hormone Antagonists 7.1 Pegylated Growth Hormone Antagonists as Therapeutic Agents 8 Finding of One Growth Hormone/Two Growth Hormone-Binding Proteins 9 Mutagenesis Studies on the Prolactin Gene 10 Concluding Remarks
Pore-forming segments in voltage-gated chloride channels

The ability to differentiate between ions is a property of ion channels that is crucial for their biological functions1. However, the fundamental structural features that define anion selectivity and distinguish anion-permeable from cation-permeable channels are poorly understood. Voltage-gated chloride (Cl−) channels belonging to the ClC family are ubiquitous and have been predicted to play important roles in many diverse physiological2 and pathophysiological3,4,5 processes. We have identified regions of a human skeletal muscle ClC isoform that contribute to formation of its anion-selective conduction pathway. A core structural element (P1 region) of the ClC channel pore spans an accessibility barrier between the internal and external milieu, and contains an evolutionarily conserved sequence motif: GKxGPxxH. Neighbouring sequences in the third and fifth transmembrane segments also contribute to isoform-specific differences in anion selectivity. The conserved motif in the Cl−channel P1 region may constitute a ‘signature’ sequence for an anion-selective ion pore by analogy with the homologous GYG sequence that is essential for selectivity in voltage-gated potassium ion (K+) channel pores6,7,8.
Structure sensitive adsorption of hydrogen on ruthenium and ruthenium-silver catalysts supported on silica

Supported metal catalysts typically consist of particles with sizes less than 10 nm, and because of the small crystallite size, low coordination number sites (edges and corners) represent a significant fraction of all surface sites. Furthermore, it has been demonstrated that adsorption rates can be much greater at these low coordination sites than on basal plane sites. What has not been generally appreciated, however, is that preferential adsorption at edge and corner sites may explain the mechanism by which a promoter, or the addition of a second metal to form a bimetallic, can alter the selectivity and rate of reaction. For example, the measurements of hydrogen adsorption onto supported Ru-Ag catalysts show marked decreases in the amount of hydrogen adsorbed relative to the amount adsorbed on Ru catalysts. Although it is known that Ag does not dissociatively adsorb hydrogen, this decrease cannot be explained by a simple one-to-one site blocking mechanism unless Ag preferentially populates edges and corners, thereby reducing the number of Ru edge sites. Indeed, Monte Carlo simulations of Ru-Group IB metal catalysts predict that Group IB metal atoms preferentially populate corner and edge sites of ruthenium crystals. This evidence, taken together, suggests that adsorption occurs preferentially at Ru corner and edge sites, which act as portals onto basal planes. A model based on this portal theory for hydrogen adsorption onto supported ruthenium bimetallic catalysts has been developed using a rate equation approach. Specifically, the model accounts for the following features: (1) preferential adsorption through portals, (2) basal plane site-energy multiplicity, and (3) hydrogen spillover onto the support. A comparison of model predictions with experiment is presented for different concentration of Ag in Ru-Ag catalysts. The portal model of hydrogen adsorption can explain the observed decreased in the amount of hydrogen adsorbed on Ru-Ag catalysts. The model can be applied to understand the kinetics of ethane hydrogenolysis on Ru-Ag catalysts. The model is able to explain the change in the apparent order of hydrogenolysis reaction with respect to hydrogen from {minus}1.4 to {minus}2.4 when Ag is added to Ru/SiO{sub 2} catalyst.
Differential response to IV carfentanil in chronic cocaine users and healthy controls

Chronic cocaine exposure in both rodents and humans increases regional brain mu-opioid receptor (mOR) binding potential, suggesting that cocaine users might have an altered response to mOR agonists. We evaluated the response to IV carfentanil (a selective mOR agonist) in 23 cocaine users [mean (standard deviation) age 33.8 (4.0) years, 83% men] who underwent positron emission tomography (PET) scanning with [C-11]-carfentanil [44.7 (19.5) ng/kg] while housed on a closed research ward and 15 healthy non-drug-using controls [43.9 (14.2) years, 80% men] scanned [49.5 (12.6) ng/kg] as outpatients. Cocaine users had used for 8.7 (4.3) years and on 73 (22)% of days in the two weeks prior to PET scanning. Common adverse effects associated with mOR agonists (nausea, dizziness, headache, vomiting, itchiness) were assessed by self-report (five-point Likert scales) during and for 90 minutes after the scans. Cocaine users were significantly less likely than controls to report any symptom (30.4% versus 60%) and had fewer total symptoms [0.43 (0.73) versus 1.1 (1.0)] during scans, even after statistically controlling for age and carfentanil dose. These differences were also present after the scans and at repeat scans performed after about one week or 12 weeks of monitored cocaine abstinence. In a larger group of cocaine users and separate controls, there was no significant group difference in carfentanil half-life, suggesting that the observed difference was pharmacodynamically, rather than pharmacokinetically, based. These findings suggest that cocaine users are less responsive than healthy controls to mOR agonist adverse effects despite having increased regional brain mOR binding potential.
Heat treatment control by polytope methods

This article addresses the problem of thermal quality regulation in a variety of manufacturing processes involving heat treating of a part of 2D geometry by a localized, sequentially moving heat source, and formulates it as a distributed-parameter, feedback control problem of the developed temperature distribution. A numerical simulation of thermal processing is developed and validated experimentally on a plasma-arc system, with infrared temperature measurement on the part surface. The design of a thermal regulator is then based on minimization of the deviation of the measured temperature field from a desired thermal distribution. A robust and efficient constrained optimization algorithm based on the concept of polytopes is employed to define the torch trajectory and heat input distribution. This distributed-parameter control strategy is tested in closed-loop operation both computationally and in the laboratory, during heat treatment of steel plates.
Die säurekatalysierte Isomerisierungsreaktion des trans‐Diaquo‐dioxalato‐chrom‐(III)‐Anions in wäßriger Lösung

Die Geschwindigkeit der Isomerisierungsreaktion des trans-[Cr(C2 O4)2(H2O)2]−-Ions wurde in Abhangigkeit von der Saure-konzentration gemessen. Wahrend die Geschwindigkeitskonstante der Reaktion bis in den Bereich von 0,6 molarer Saure eine Proportionalitat zur titrimetrisch bestimmten Wasserstoffionenkonzentration zeigt, steigt sie bei hoherer Saurekonzentration mehr als proportional an. Mit Hilfe der modifizierten Hammettschen Aciditatsfunktion konnte die Starke Beschleunigung der Reaktion als Saurekatalyse gedeutet werden, wobei das Komplexion in einem dem geschwindigkeitsbestimmenden Schritt vorgelagerten Gleichgewicht protoniert wird. Sowohl der ermittelte Deuteriumisotopieeffekt der Reaktion und seine Abhangigkeit von der Saurekonzentration als auch die Ergebnisse in D2 O-H2O-Mischungen und ihre Deutung durch die Gross-Butler-Gleichung stutzen den angenommenen Mechanismus der Saurekatalyse. The rate of the isomerization reaction of the trans-[Cr(C2 O4)2 (H2 O)2]− ion was studied in respect to its acid concentration dependence. While the rate constant of the reaction shows a direct proportionality to the titrimetrically determined hydrogen ion concentration up to about 0.6 molar acid, it increases more than proportionally at higher acid concentrations. Using a modified Hammett-acidity function this strong acceleration of the reaction could be explained as an acid catalysis during which the complex ion is protonated in an equilibrium preceding the rate determining step. The deuterium solvent isotope effect of the reaction and its acid concentration dependence as well as the results obtained in D2 O–H2 O mixtures and their interpretation on the basis of the Gross-Butler equation support the assumed mechanism of an acid catalysis.
Viscoelastic Immersed Boundary Methods for Zero Reynolds Number Flow

The immersed boundary method has been extensively used to simulate the motion of elastic structures immersed in a viscous fluid. For some applications, such as modeling biological materials, capturing internal boundary viscosity is important. We present numerical methods for simulating Kelvin-Voigt and standard linear viscoelastic structures immersed in zero Reynolds number flow. We find that the explicit time immersed boundary update is unconditionally unstable above a critical boundary to fluid viscosity ratio for a Kelvin-Voigt material. We also show there is a severe time step restriction when simulating a standard linear boundary with a small relaxation time scale using the same explicit update. A stable implicit method is presented to overcome these computation challenges. AMS subject classifications: 65M06,65M12,74F10,76D07,76M20
Restoration of a smart distribution system

The response of demands to disturbed supply conditions is considered in this paper as an input parameter for the decision of the restoration of a smart distribution system. A new module to investigate the response of demand side to the disturbances in the decision of restoration plan is developed. With the installation of advanced metering devices at homes and businesses the end-use customers are provided opportunities to actively participate in the network Demand Response (DR) program. Based on the proposed method in this paper the predetermined or real-time demand response capacity from end-use customers is deemed as an input to the restoration process. This new module simplifies the calculation of restoration plans and thus, enables the utility to restore customers more rapidly. Moreover it provides a more flexible and information rich platform for the restoration of a smart distribution system.
Hepatic hemangiomas: difference in enhancement pattern on 3T MR imaging with gadobenate dimeglumine versus gadoxetate disodium.

Abstract Purpose To compare intraindividual differences in enhancement pattern of hepatic hemangiomas between gadobenate dimeglumine (Gd-BOPTA) and gadoxetate disodium (Gd-EOB-DTPA)-enhanced 3T MR imaging. Materials and methods This is a HIPAA-compliant, IRB-approved retrospective study with waiver for informed consent granted. From 10/07 to 5/09, 10 patients (2 males, 8 females; mean age, 57.3 years) with 15 hepatic hemangiomas (mean diameter, 4.4 ± 5.6 cm) underwent both Gd-BOPTA- and Gd-EOB-DTPA-enhanced 3T MR imaging (mean interval, 266 days; range, 38–462 days). Diagnosis of hemangioma was based on strict imaging criteria. MR imaging was obtained during three arterial, portal venous, and up to four delayed phases. During each phase, hemangioma-to-liver contrast-to-noise ratio (CNR) was measured for each lesion on both examinations. Statistical analysis was performed using paired Student's t-test. Results Hemangioma-to-liver CNR peaked during the portal venous phase (Gd-BOPTA: 48.9 ± 65.8, Gd-EOB-DTPA: 0.7 ± 3.8). During all imaging phases except the first arterial phase, hemangioma-to-liver CNR was significantly lower on Gd-EOB-DTPA-enhanced compared to Gd-BOPTA-enhanced MR images (p Conclusion The enhancement patterns of hepatic hemangiomas differs significantly between Gd-BOPTA and Gd-EOB-DTPA-enhanced 3T MR imaging. The smaller dose, shorter plasma half-life, and increased hepatobiliary uptake of Gd-EOB-DTPA leads to a negative CNR of hemangioma-to-liver on delayed phases and could create an imaging pitfall with this agent.
A Markovian model for harvested power from human motion

Empirical acceleration measurements are collected at 4 body locations from 20 subjects during normal daily activities. The measured acceleration is converted to the harvestable power assuming a velocity-damped resonant generator. Based on the calculated harvestable power, a simple Markovian model with two power levels and three states is developed.
Why should historical truth matter to mathematicians? Dispelling myths while promoting maths

This is the text of the keynote lecture delivered to the Research in Progress meeting of the British Society for the History of Mathematics at The Queen's College, Oxford, 24 February 2007.
Low-Coordinate Aluminum Amides from Silylanilines and Alkylalanes

The aluminum amides R2AlN(Ar)SiMe3 [R = Et, Ar = Dipp, 1 (Dipp = 2,6-iPr2C6H3-); R = iBu, Ar = Dipp, 2; R = Et, Ar = Mes, 3 (Mes = 2,4,6-Me3C6H2-); R = iBu, Ar = Mes, 4] were prepared by ethane or hydrogen elimination reaction between Et3Al or iBu2AlH and ArN(H)SiMe3 in refluxing hexane solution. The LiCl salt elimination route resulted in the formation of the monomeric aluminum amide Et2AlN(Mes)SiPh3 (5) featuring three-coordinate aluminum and nitrogen centers. In addition, the synthesis and characterization of the dinuclear species Ph2Si{N(Mes)AlEt2}2 (6) and the hydride-bridged eight-membered ring compound {MesN(SiMe3)Al(iBu)(μ-H)}2(μ-LiH)(μ-iBu2AlH) (7) are reported. All compounds have been characterized by 1H and 13C{1H} NMR spectroscopy, and compounds 5, 6, and 7 have also been characterized by single-crystal X-ray crystallography.
On the Radiofrequency Spectra of Sodium, Rubidium and Caesium

The hyperfine structures of the ground state of ${\mathrm{Na}}^{23}$, ${\mathrm{Rb}}^{85}$, ${\mathrm{Rb}}^{87}$ and ${\mathrm{Cs}}^{133}$ were measured by observing radiofrequency spectra of these atoms. In each case the particular lines chosen for study and the magnetic fields at which they were observed were such as to yield the greatest precision for the hyperfine structure measurements, consistent with frequencies conveniently obtainable in our laboratory (up to 700 megacycles). The measured h.f.s. separations are given both in absolute frequency units and in wave numbers.
Field mapping without reference scan using asymmetric echo-planar techniques.

Improvements in B(o) mapping and shimming were achieved by measuring the static field information in multiple subsequent echoes generated by an asymmetric echo-planar readout gradient train. With careful compensation, eddy current effects were shown to affect the adjustment of the shim coils minimally. In addition to reducing the time required for field mapping by two-fold, the sensitivity was simultaneously optimized irrespective of the prevalent T2/* present, thereby minimizing the error of the static field measurement to below 0.1 Hz. With adiabatic low flip-angle excitation, the time required for field mapping was below 1 second. (C) 2000 Wiley-Liss, Inc.
Exact effective-stress rules in rock mechanics

The standard paradigm for analysis of rock deformation arises from postulating the existence of ``an equivalent homogeneous porous rock.'' However, data on the pore-pressure dependence of fluid permeability for some rocks cannot be explained using any equivalent homogeneous porous medium. In contrast, a positive result shows that deformation measurements on both high-porosity sandstones and low-porosity granites can be explained adequately in terms of an equivalent two-constituent model of porous rocks, for which exact results have recently been discovered.
An assay for adenyl cyclase.

Abstract A method for measuring adenyl cyclase in “membrane” fraction of animal tissues has been developed. The assay measures the conversion of 14 C-adenosine 5′-triphosphate to 14 C-adenosine 3′,5′-monophosphate. The incubation is carried out at 30°C in the presence of caffeine, magnesium, phosphoenolpyruvic acid, pyruvate kinase, Tris buffer, and adenosine 5′-triphosphate. The 14 C-adenosine 3′,5′-monophosphate was isolated by paper chromatography and the amount determined by counting in a liquid scintillation counter. The assay has been characterized with respect to optimal pH, magnesium concentration, temperature, caffeine concentration, and time of incubation. Stimulatory effects on the system by sodium fluoride have been observed. The addition of adenosine 3′,5′-monophosphate, guanosine triphosphate, and uridine triphosphate had no effect on adenyl cyclase activity. A linear response with increasing amounts of tissue has been demonstrated. The assay has general applicability to the study of adenyl cyclase in tissues and the effect of various hormones.
Pilot clinical trial of a robot-aided neuro-rehabilitation workstation with stroke patients

ABSTRACTThis paper summarizes our efforts to apply robotics and automation technology to assist, enhance, quantif', and documentneuro-rehabilitation. It reviews a pilot clinical trial involving twenty stroke patients with a prototype robot-aided rehabilitation facilitydeveloped at MIT and tested at Burke Rehabilitation Hospital. In particular, we present a few results: (a) on the patient's tolerance ofthe procedure, (b) whether peripheral manipulation of the impaired limb influences brain recovery, (c) on the development of arobot-aided assessment procedure.Keywords: robot-aided, therapy, stroke, neurological disorder, arm movement.INTRODUCTION"Most ofwhat is regarded as high science in medicine is actually a set oftechnologiesfor diagnostic precision -- the CATscan, NMR and many exquisite refinements ofour methodsfor detecting biochemical abnormalities ofone sortor another. But these have not yet been matched by any comparable transformation of therapy." -- Lewis Thomas, 1992, The Fragile Species.Neuro-rehabilitation is labor-intensive, relying on therapy and evaluation procedures that are typically administered by a single
F-stable and F[α,β]-stable integration/interpolation methods in the solution of retarded differential-difference equations

Abstract The equation u (t)= F 0 u (t)+ ∑ i=1 m F i u (t−τ i ) is presented as an archtype (vector-valued) equation for assessing the quality of integrator/interpolator pairs used to solve retarded differential-difference equations. F-stability and F[α,β]-stability, defined with respect to this archetype equation, are proposed as desireably properties of integrator/interpolator pairs. Relationships of these properties to stability and order properties of multistep integrators and to boundedness and order properties of Lagrange interpolators are developed.
Synthesis and Anticonvulsant Activity of a New Class of 2-[(Arylalkyl)amino]alkanamide Derivatives

Although most epilepsies are adequately treated by conventional antiepileptic therapy, there remains an unfulfilled need for safer and more effective anticonvulsant agents. Starting from milacemide, a weak anticonvulsant, and trying to elucidate its mechanism of action, we discovered a structurally novel class of potent and preclinically safe anticonvulsants. Here we report the structure−activity relationship (SAR) study within this series of compounds. Different parts of the structural lead 2-[[4-(3-chlorobenzoxy)benzyl]amino]acetamide (6) were thus varied (Figure 1), and many potent anticonvulsants were found. As an outcome of this study, 57 ((S)-2-[[4-(3-fluorobenzoxy)benzyl]amino]propanamide methanesulfonate, PNU-151774E) emerged as a promising candidate for further development for its potent anticonvulsant activity and outstanding therapeutic indexes (TIs) in different animal tests.
Tradeoff study among traffic egression schemes and member allocation optimization for link aggregation groups in integrated switching systems

An integrated switching system (ISS) is an integration of individual switching devices with newly developed control and management protocols, in an integration topology that interconnects the switching devices. It scales the capacity of individual switching devices while functions still as a single switching facility to the outside network. In an ISS, a link aggregation group (LAG) has flexibility to allocate its member links across different switching devices, often as an attempt to spread risk of failure to individual switching devices. Due to existence of the integration topology, traffic admitted into the ISS and destined to egress out of the LAG interface may need to travel a number of hops before leaving the ISS. This lays a bandwidth burden on the integration links of the ISS. Local biasing and designated forwarding have been proposed as LAG egression options to relieve the bandwidth pressure on integration links. They bias traffic egression to be from the neighborhood of the switching device where the traffic ingresses, if the traffic is destined to the LAG interface and a LAG member link is present in the neighborhood. Those enhanced LAG egression schemes are in contrast to the regular LAG egression scheme, in which the traffic will be split and evenly distributed across all LAG members, regardless of their topological distance to the switching device where it ingresses. Although the enhanced egression schemes help to reduce the bandwidth demand on the integration links, there comes a price that load balance across LAG members may be sacrificed and eventually stable LAG capacity could be compromised. In this paper, we study such performance tradeoff and investigate impact factors on LAG performance. In the end, we formulate an optimization problem that optimizes LAG member allocation via pursuing the best tradeoff between integration bandwidth utilization and stable LAG capacity. The solution can be treated as a guideline to deploy LAGs in an ISS. The results show, with optimized LAG member allocation, the potential of integration bandwidth saving and stable LAG capacity maintenance can be maximally explored.
Isotype switching of an immunoglobulin heavy chain transgene occurs by DNA recombination between different chromosomes.

Abstract Transgenic mice carrying an immunoglobulin μ heavy chain transgene exhibit isotype switching of the transgene. We have now characterized the mechanism of transgene switching in these mice. The site of μ transgene insertion in one transgenic line has been localized to chromosome 5 using a series of polymorphic endogenous retroviruses as genetic markers in backcross mice. The endogenous immunoglobulin heavy chain locus resides on mouse chromosome 12, which shows that transgene isotype switching can occur between two different chromosomes even though normal antibody gene switching has generally been thought to occur within one chromosome. We find that transgene isotype switching involves interchromosomal DNA recombination, and our data suggest that the same enzymatic mechanisms mediate both normal isotype switch recombination and interchromosomal transgene switching. Our findings also support the notion that the isotype switching mechanism can induce chromosomal translocations such as observed for the c- myc gene in some B cell tumors.
The movers and shakers of deep brain stimulation.

Deep brain stimulation is increasingly used in the treatment of Parkinson's disease, essential tremor and other disorders, yet its mechanism of action remains unknown. New findings suggest that at least some of its action involves the release of adenosine, dampening tremors (pages 75–80 ).
Screening for sickle cell trait: The veterans administration national sickle cell program

Results of the Veterans Administration Sickle Cell Program for a period of 10 years are presented. We screened 370,250 patients; 404,341 attended educational sessions, and 38,347 had individual counseling sessions. Sickle cell trait was present in 6.4% of patients, and HbC trait was present in 1.8%. The clinically significant disorders HbSC disease, sickle cell anemia, and sickle beta thalassemia were present in 0.41% of individuals screened. A large number of uncommon variants were detected. The program enhanced the awareness of and the approach to evaluation of hemoglobinopathies.