cssi/SciSciGPT-SciSciNet huggingface dataset:
Sulfonamide separations based on ion‐exchange chromatography in combination with radioactive techniques

A method is presented for the quantitative determination of sulfonamides based on the differences in their distribution coefficients. It appears to be suitable for the assay of sulfonamides and their derivatives in pure form as well as in pharmaceutical preparations. The procedure consists essentially in the adsorption of the sulfonamides from an aqueous acidic solution on a column of ion-exchange resin. Finally, the individual sulfonamides are chromatographically eluted and measured quantitatively using the isotope dilution technique.
Performing civic identity: The iconic photograph of the flag raising on Iwo Jima

Iconic photographs are widely recognized as representations of significant historical events, activate strong emotional response, and are reproduced across a range of media, genres, or topics. The appeal of the iconic image of a group of Marines raising the U.S. flag on Iwo Jima arises from its embodiment of three discourses of political identity— egalitarianism, nationalism, and civic republicanism. Its appropriations reflect a range of public attitudes‐civic piety, irony, nostalgia, and cynicism. The role of visual icons in constructing civic attitudes to mediate historical events was underscored by the use of the flag‐raising image following the terrorist attacks of September 11, 2001.
Modeling the 1994 April 14 Polar Crown SXR Arcade Using Three-Dimensional Magnetohydrostatic Equilibrium Solutions

The coronal magnetic —eld in the polar crown soft X-ray (SXR) arcade of 1994 April 14 has been computed using the global photospheric magnetic —eld distribution constructed for the time of interest and the three-dimensional magnetohydrostatic equilibrium solutions. In the solutions there are two free parameters, a and a, respectively, characterizing the eUect of the —eld-aligned and horizontal electric cur- rents. Magnetic —eld con—gurations have been determined for various combinations of a and a. The magnetic arcade computed with a ) 0 and a \ 0.9 agrees best in shape and size with the well-developed polar crown SXR arcade. This suggests that the well-developed SXR arcade has a potential-like magnetic con—guration with non¨—eld-aligned currents. The computed loci of the apexes of lines of force that close above 1.3 match the shape of the bright axial features superposed on the well-developed SXR arcade. R _ This suggests that newly opened lines of force may have reconnected only above 1.3 and conse- R _ , quently the pre-eruption closed lines of force may not be completely opened up during the eruption phase. The SXT images before the formation of the SXR loop show the occurrence of dimmings, sup- porting the inference of partially ii transient ˇˇ coronal opening. Subject headings: Sun: coronaSun: magnetic —eldsSun: X-rays, gamma rays
Structure of high-pressure KNO3-IV

Potassium nitrate has seven polymorphs in the pressure range to 40 kbar. The structures of the three phases obtainable at atmospheric pressure are known. Attempts to solve the structure of high pressure KNO3 phase IV by X-ray diffraction have been unsuccessful. We have now solved this structure using time-of-flight neutron powder diffraction data taken at room temperature and 3.6 kbar on the SEPD at IPNS. High pressure KNO3-IV has the same space group and point group symmetry as the low pressure KNO3-II, but with different values for lattice parameters and atomic positions. The structure of KNO3-IV is orthorhombic Pnma with a = 7.4867(2), b = 5.5648(2), and c = 6.7629(2) with four formula units per unit cell. The K, N, and one O atom are in special positions (4c) and the other O atoms are in the general position (8d) just as in the atmospheric pressure phase. The O-N-O bond angles are 120.4(1)°, and 119.3(2)°. The N-O bond lengths are 1.228(3) A and 1.246(2) A.
Book metaphor: friend or foe?

This paper illustrates an online information system that combines the direct access to information of true hypertext, with the traditional navigation methods of a book-oriented documentation library. It demonstrates navigational methods that combine the book metaphor with other kinds of navigation. It explores when to emphasize the book metaphor and when to hide it.
New DNA minor-groove binding molecules with high sequence-selectivities and binding affinities.

Abstract New DNA minor-groove binding molecules with high binding affinities and sequence-selectivities are described. The effects of structural changes in ligands with a three-ring backbone on their DNA-binding properties have been studied. Of a pool of eight potential ligands, two showed binding affinities and sequence-selectivities rivaling distamycin. The two best ligands share a common structural motif that involves apara-di-substituted benzene ring flanked by twometa-di-substituted benzene rings.
HeartCare: an Internet-based information and support system for patient home recovery after coronary artery bypass graft (CABG) surgery

HeartCare is an Internet-based information and support service for patients recovering at home from coronary artery bypass graft (CABG) surgery. The system is designed to meet the nursing challenges in health information to support needs of CABG patients. HeartCare (a) provides information and support, tailored to patients' individual and changing recovery needs during CABG recovery, (b) makes recovery information more accessible for timely use by patients, and (c) extends the scope of nursing services to CABG patients from hospital through home. An ongoing randomized controlled study is underway to evaluate the clinical outcomes of patients' use of the HeartCare system and to examine its acceptance as a usable resource for postCABG patients who have limited previous computer experience.
793-2 Efficacy of Locally Delivered Low Molecular Weight Heparin (Enoxaparin) on Smooth Muscle Cell Proliferation

Enoxaparin (EN), when systemically administered, has been shown to reduce restenosis in preclinical studies. Previously, we demonstrated that 3 H-EN locally delivered via channeled balloon (CB), a dual-purpose local delivery catheter capable of simultaneous angioplasty, was retained intramurally for at least 24 hours, To determine whether locally delivered EN can reduce restenosis by inhibiting smooth muscle cell proliferation, 3 groups of rabbits underwent balloon injury of bilateral iliac arteries with CB (balloon/artery = 1.1), followed by assigned treatment [4 control rabbits (CO) receiving local saline in 8 arteries, 4 local EN rabbits (LOC) receiving one-time local EN @ 10 mg/kg at the time of angioplasty in 8 arteries, and 5 combined treatment rabbits (COM) receiving one-time local EN @ 10 mg/kg in 10 arteries and systemic EN @ 10 mg/kg s.c. daily for one week). One week later, the animals were euthanized and the iliac arteries were perfusion fixed for proliferating cell nuclear antigen (PCNA) staining. Anti-factor Xa activity (A-Xa) as a measure of successful EN delivery was measured at baseline (0.024 ± 0.02 units/ml), 1 hour and 24 hours after the procedure. PCNA (7 days) † A-Xa (units/ml) Media Intima 1 hour 24 hours CO 4.04 ± 2.6 25.5 ± 8.4 0.02 ± 0.03 0.06 ± 0.07 LOC 4.8 ± 4.1 16.9 ± 11.9 ††† 1.25 ± 0.27 * 0.12 ± 0.05 COM 1.6 ± 2.2 †† 7.3 ± 9.2 †††† 1.43 ± 0.12 * 0.20 ± 0.10 ** † (+) PCNA nucle/μm2 †† p = 0.06 vs. CO ††† p = 0.09 vs. CO †††† p = 0.001 vs CO * p g 0.005 vs. CO ** p g 0.05 vs. CO We conclude that (1) Locally delivered enoxaparin tended to reduce smooth muscle cell proliferation, and significantly inhibited smooth muscle cell proliferation with concomitant systemic enoxaparin treatment, as assessed by PCNA staining; (2) Supporting local enoxaparin effect with systemic treatment at critical time point for smooth muscle cell proliferation seems necessary: and (3) anti-Factor Xa activity levels suggest sustained (up to 24 hours) enoxaparin activity only with combined local and systemic treatment.
Collaborative care: pathways to quality outcomes.

In 1990, The Memorial Hospital at Easton, Maryland, Inc., a not-for-profit 183-bed rural community hospital, recognized a need to explore alternative patient care methods or approaches to improve the continuity of care, focus on healthier patient outcomes, and contain costs. The concept of collaborative care became the focus for patient care delivery. Multidisciplinary teams were established to coordinate patient care activities for patient populations identified through the total quality management/continuous quality improvement process. Plans of care, referred to as critical pathways, identify intermediate goals and interventions, providing guidance for the patient, family, and healthcare providers as they work to achieve quality outcomes. As the patient progresses along the critical pathway, variances from the established goals are monitored and become the focus of quality reviews.
Cheyenne names and cosmology

Cheyenne personal names reflect the structure of formal cosmology, both in the kinds of names selected and their frequency of appearance. A quantitative and statistical analysis of the 1880 U.S. Census shows a congruence between ethnobiology and the sex and ages of name-bearers and confirms ethnographic assertions about naming and name changing from 1810 to the present. [Cheyenne, census, ethnobiology, cosmology, names]
IN OVULO EMBRYO DEVELOPMENT AND PLANT FORMATION FROM STENOSPERMIC GENOTYPES OF VITIS VINIFERA

Embryo enlargement and plant formation via in ovulo embryo culture was studied in stenospermic grapes. Genotypes, culture media and their interactions significantly affected embryo enlargement, whereas culture dates did not. Genotype P60-58, when compared to cv. Thompson Seedless, had the greatest number of enlarged embryos after 3 months in culture. P60-58 ovules cultured on Cain's basal medium plus L-serine or L-glutamine and cv. Thompson Seedless ovules cultured on Cain's basal medium plus L-cysteine or L-asparagine produced the greatest number of enlarged embryos. Viable embryos and morphologically normal-appearing plants were obtained. Polyembryony was observed in cultured zygotic embryos.
High-performance data management for genome sequencing centers using Globus Online: A case study

In the past few years in the biomedical field, availability of low-cost sequencing methods in the form of next-generation sequencing has revolutionized the approaches life science researchers are undertaking in order to gain a better understanding of the causative factors of diseases. With biomedical researchers getting many of their patients' DNA and RNA sequenced, sequencing centers are working with hundreds of researchers with terabytes to petabytes of data for each researcher. The unprecedented scale at which genomic sequence data is generated today by high-throughput technologies requires sophisticated and high-performance methods of data handling and management. For the most part, however, the state of the art is to use hard disks to ship the data. As data volumes reach tens or even hundreds of terabytes, such approaches become increasingly impractical. Data stored on portable media can be easily lost, and typically is not readily accessible to all members of the collaboration. In this paper, we discuss the application of Globus Online within a sequencing facility to address the data movement and management challenges that arise as a result of exponentially increasing amount of data being generated by a rapidly growing number of research groups. We also present the unique challenges in applying a Globus Online solution in sequencing center environments and how we overcome those challenges.
A study of some 1-alkyl-2,3-dihydroimidazo[1,2-a]benzimidazoles

A series of 1-alkyl-7-nitro (and 7-amino)-2,3-dihydroimidazo[1,2-α]benzimidazoles has been prepared. Similarly, a series of 1-alkyl-2,3-dihydroimidazo[1,2-α]benzimidazoles has been prepared. The prototropic tautomerism of this system has been studied. The site of electrophilic attack (alkylation) has been examined. 1-Alkylation takes place under strongly basic conditions and 9-alkylation occurs under neutral conditions.
Children of the stones: The Intifada and the mythic creation of the Palestinian state

This essay explores the rhetorical significance of the 1987–1993 Palestinian uprising known as the “Intifada.” Eschewing traditional notions of nationalism that focus on military conquest or diplomatic treaties, the authors argue that the “children of the stones” use mythic tales as a way of creating a collective identity, a historical tradition, and a Palestinian nation. Building on the work of other communication scholars, the essay claims that symbolic constructions were an important part of the persuasive efforts of Palestinians who sought to mobilize support for the Intifada.
“A Woman in the Army Is Still a Woman”: Representations of Women in US Military Recruiting Advertisements for the All-Volunteer Force

This article examines the ideals of militarized femininity disseminated in recruitment advertising. Based on an analysis of 30 years of recruitment advertisements for each of the four US military branches, I argue that representations of women serve to at once normalize the participation of women in the military and to erase it. The inclusion of a token number of women is routine, but they are not associated with markers of combat. By separating women from the imagery of war, the military reinforces gender divisions, reasserting the connections between masculinity and warriorhood, even as it helps to broaden definitions of femininity.
Rhizodeposition stimulated by elevated CO2 in a semiarid grassland

Summary • Rhizodeposition, or the addition of C from roots to soil C pools, is expected to increase if net primary production is stimulated and some excess C is allocated below-ground. We investigated the effects of 5 yrs of elevated CO 2 on belowground C dynamics in a native, C 3 ‐C 4 grassland ecosystem in Colorado, USA. • Cylinder harvests following each growing season and monolith excavation at the end of the experiment provided data on root biomass, root C : N ratios, and root and soil δ 13 C values. We applied an isotopic mixing model to quantify new soil C inputs on elevated and ambient CO 2 treatments. • Root biomass increased by 23% and root C : N ratios increased by 26% after 5 yrs of elevated CO 2 . Species-specific differences were found in root residence times, which ranged from 6 to 8 yrs. • Rhizodeposition was roughly doubled in elevated compared with ambient CO 2 chambers, at 83 ± 16 versus 35 ± 9 g C m − 2 yr − 1 over the last 4 yrs of the experiment ( t -test, P = 0.006). Net C sequestration will depend on how decomposition rates are altered by elevated CO 2 .
Provider Utilization of High‐Risk Donor Organs and Nucleic Acid Testing: Results of Two National Surveys

Fears of infectious transmission from CDC high-risk donors (HRDs) remain a significant disincentive, and the potential for human immunodeficiency virus/hepatitis C virus (HIV/HCV) nucleic acid testing (NAT) to allay these fears remains unstudied. We hypothesized that NAT, which narrows the window period between infection and detectability compared to the standard ELISA, might lead to increased provider willingness to use HRDs. Between January and April 2008, we performed two national surveys: one of current NAT practice among organ procurement organizations (OPOs); a second of HRD use among transplant surgeons. Surgeons who reported accepting 10% or more offers for a given HRD behavior and organ type were classified as ‘high utilizers’ of that subgroup. We built hierarchical models to examine associations between OPO NAT performance and provider utilization. Providers who ranked medical risks of HIV or HCV as important disincentives to HRD use had significantly lower odds of being high utilizers (HIV odds ratio 0.22, HCV odds ratio 0.41, p < 0.005). Furthermore, both HIV and HCV NAT performance were associated with significantly higher odds of being high utilizers (HIV odds ratio 1.58, HCV 2.69, p < 0.005). The demonstrated associations between OPO NAT performance and high provider utilization of HRDs should be considered in the ongoing debate about NAT in transplantation.
Perceptron error surface analysis: a case study in breast cancer diagnosis.

Abstract Perceptrons are typically trained to minimize mean square error (MSE). In computer-aided diagnosis (CAD), model performance is usually evaluated according to other more clinically relevant measures. The purpose of this study was to investigate the relationship between MSE and the area (Az) under the receiver operating characteristic (ROC) curve and the high-sensitivity partial ROC area (0.90Az′). A perceptron was used to predict lesion malignancy based on two mammographic findings and patient age. For each performance measure, the error surface in weight space was visualized. Comparison of the surfaces indicated that minimizing MSE tended to maximize Az, but not 0.90Az′.
The art of testing less without sacrificing quality

Testing is a key element of software development processes for the management and assessment of product quality. In most development environments, the software engineers are responsible for ensuring the functional correctness of code. However, for large complex software products, there is an additional need to check that changes do not negatively impact other parts of the software and they comply with system constraints such as backward compatibility, performance, security etc. Ensuring these system constraints may require complex verification infrastructure and test procedures. Although such tests are time consuming and expensive and rarely find defects they act as an insurance process to ensure the software is compliant. However, long lasting tests increasingly conflict with strategic aims to shorten release cycles. To decrease production costs and to improve development agility, we created a generic test selection strategy called THEO that accelerates test processes without sacrificing product quality. THEO is based on a cost model, which dynamically skips tests when the expected cost of running the test exceeds the expected cost of removing it. We replayed past development periods of three major Microsoft products resulting in a reduction of 50% of test executions, saving millions of dollars per year, while maintaining product quality.
The effects of temperature and humidity exposure on reliability of silicon nanowires

Material reliability is among the crucial factors that impact material performances before device applications. In order to predict material reliability, accelerated aging study-a study to predict material shelf life when subjected to temperature and humidity, was performed on silicon nanowires. We investigated the effects of process conditions on the diameter and the quality of SiNWs using Atomic Force Microscopy followed by statistical analysis. The experimental results revealed diameter of SiNWs has a linear relationship with changing temperature and humidity. These results are of significant importance and will be a critical design consideration for the use of SiNWs in biomedical implants.
Substrate binding induces a cooperative conformational change in the 12S subunit of transcarboxylase: Raman crystallographic evidence.

The 12S subunit of transcarboxylase is a 338 000 Da hexamer that transfers carboxlylate from methylmalonyl-CoA (MM-CoA) to biotin; in turn, the biotin transfers the carboxylate to pyruvate on another subunit, the 5S. Here, Raman difference microscopy is used to study the binding of substrate and product, and their analogues, to single crystals of 12S. A single crystal is the medium of choice because it provides Raman data of unprecedented quality. Crystalline ligand−protein complexes were formed by cocrystallization or by the soaking in/soaking out method. Raman difference spectra were obtained by subtracting the spectrum of the apo crystal from that of a crystal with the substrate or product bound. Raman difference spectra from crystals with the substrate bound are dominated by bands from the protein's amide bonds and aromatic side chain residues. In contrast, Raman difference spectra involving the product, propionyl-CoA, are dominated by modes from the ligand. These results show that substrate binding t...
Effect of deformation on low-temperature deuteride precipitation in single crystal niobium

Small-angle neutron scattering (SANS) measurements of low concentration, single crystal Nb - D alloys have been performed to characterize the effect of deformation on deuteride phase formation. The SANS response from the deuteride phase formed at low temperature in the undeformed matrix was consistent with a spherical particle morphology, as expected from a large body of published TEM studies. In addition, a significant hysteresis was observed in the SANS response versus temperature from the undeformed sample material. The hysteresis is attributed to the irreversible plastic deformation required to nucleate the incoherent phase. Deformation produced by unidirectional rolling to 50% thickness reduction altered the deuteride phase transformation characteristics in a fundamental way. The SANS response was highly anisotropic, indicative of an oriented, anisometric particle morphology. Metallographic analysis of deformed specimens electropolished below the solvus temperature confirmed the presence of large deuteride plates with an orientation consistent with the anisotropic SANS response. Deformation also eliminated the temperature hysteresis observed in the undeformed material. A cellular dislocation substructure was found in TEM characterization of the deformed Nb single crystal material. The plate-like particle morphology in the deformed material is attributed to an interaction between the precipitating deuterium and the cellular dislocation substructure. The elimination of the temperature hysteresis is consistent with an interaction between the deuterium and regions of high dislocation density facilitating heterogeneous nucleation.
Histidine abolishes the inhibition by zinc of naloxone binding to opioid receptors in rat brain.

Abstract Zinc ions inhibited the specific binding of [ 3 H]naloxone to opioid receptors in the hippocampus, cortex, midbrain and striatum of the rat in a dose-dependent manner. Scatchard analysis performed by using a concentration of zinc close to its IC 50 (about 30 μM) revealed that inhibition was due to a decrease in receptor affinity, without change in the number of binding sites. Of several compounds tested, only histidine was capable of reversing the inhibition by zinc in these areas of the brain so preventing the zinc-induced increase in the K D of opioid receptors for naloxone. Histidine alone did not affect the K D or B max of opioid receptors for [ 3 H] naloxone in the areas of brain studied. The fact that histidine prevented the zinc-induced increase in the K D but had no effect on receptor affinity or the number of binding sites for [ 3 H] naloxone suggests that histidine exerts its effects by complexing with zinc ions and acting as a chelator. In addition to Zn 2+ , Cu 2+ , Cd 2+ and Hg 2+ inhibited the binding of [ 3 H] naloxone to opioid receptors in the cerebral cortex of the rat in a dose-dependent manner. However, histidine was not capable of abolishing the inhibition to the same extent as that of zinc. Thus, among all of the metal ions studied, the most dramatic effect of histidine was observed with zinc ions.
Remittances from labor migration: evaluations, performance and implications.

2 evaluative views of worker remittances draw opposite conclusions. The negative one posits that remittances increase dependency contribute to economic and political stability and development distortion and lead to economic decline that overshadows a temporary advantage for a fortunate few. The positive view sees remittances as an effective response to market forces providing a transition to an otherwise unsustainable development. They improve income distribution and quality of life beyond what other available development resources could deliver. The implications are tested for labor supply countries to Europe and the Middle East. The implications of the negative are not supported. Although the dire predictions of the pessimistic view have not materialized the converse - contributions of remittances to economic performance - should not be overstated due to a lack of data. (authors)
Exploring data structure of New York Bight benthic data using post-collection stratification of samples, and linear discriminant analysis for species composition comparisons

Abstract Techniques for exploring data structure from four cruises on a rectilinear sampling grid system on the New York Bight are presented. The problem of microenvironmental variability is handled by post-collection stratification of samples based on the physical characteristics of each grab, rather than classical spatial strata definitions. The three physical variables used to define strata are: mean particle size, per cent organic matter, and total concentration of selected heavy metals. Variations in species densities within strata over time are investigated. Multivariate discriminant techniques are used to search for major statistical differences in a species abundance between strata. A flexible sampling program based on post-collection stratification is suggested to detect shifts in mean species abundance within strata over time.
Genetic analysis with man-mouse somatic cell hybrids. Linkage between human lactate dehydrogenase A and B and peptidase B

Genetic Analysis with Man–Mouse Somatic Cell Hybrids: Linkage between Human Lactate Dehydrogenase A and B and Peptidase B
Thermal Runaway in Ceramics Arising from the Temperature Dependence of the Thermal Conductivity

Thermal runaway during microwave heating in ceramic materials has been explained recently in terms of a microscopic model involving a nonlinear feedback between microwave absorption and heat dissipation. We study here an alternate model of thermal runaway which is based on the temperature dependence of the thermal conductivity of the material being heated. If the thermal conductivity decreases as the temperature increases, a decrease could occur in the removal of heat from the central regions of the sample which, unlike the surface, cannot cool off quickly through processes such as radiation. The result would be an enhanced heating of the central regions and a further decrease of the thermal conductivity thus providing a feedback loop. A quantitative analysis of these concepts is provided.
Dietary factors related to preservation of oral and skeletal bone mass in women

Skeletal bone loss in adults increases the risk of bone fractures and may contribute to the loss of teeth in healthy postmenopausal women. The relationship of skeletal osteopenia to residual ridge resorption is unclear. Low bone mass in women is attributed to heredity, estrogen deficiency, a low lifetime calcium intake, and lack of regular physical activity. A high calcium intake will promote optimal bone growth in youth and decrease the rate of bone loss in the later postmenopausal period. In early menopause, estrogen is the only effective therapy for conserving bone in women. In older women, a high plasma level of vitamin D enhances calcium absorption, whereas high sodium, protein, alcohol, and caffeine intakes will cause increased urinary losses and negative calcium balance. Women who have a low intake of dairy foods may benefit from a refined calcium carbonate supplement that contains vitamin D. This article focuses on the nutritional factors that influence bone health.
Critical Incident Competencies of Mexican American and Anglo American Administrators.

This study sought to identify, analyze, describe, and compare the performance behaviors of Mexican American and Anglo American deans and chairpersons in Texas public community/junior colleges as they resolved a set of critical incident situations. The methodology was derived from two well‐known techniques: (1) the Critical Incident Technique (CIT), and (2) the Behavioral Event Interviewing Technique (BEIT). The application of this methodology consisted of writing and using a set of validated critical incident scenarios to collect data. The data were collected by interviewing respondents about how they would resolve the critical situations described in the scenarios. The respondents were two groups of Mexican Americans—seven deans and seven chairpersons—and two similar comparison groups of Anglo Americans. These groups were selected from two colleges having different proportions of Spanish‐sumamed students. Interview protocols were keyed to a set of generic managerial competencies used by respondents accor...
MADS about Gnetales.

The evolutionary origin of flowering plants (angiosperms) has long been the most prominent unresolved issue in plant evolutionary biology. Darwin called it an “abominable mystery” because angiosperms seemed to appear suddenly, in considerable diversity, but without obvious antecedents. More than a century later, the problem still remains unsolved.
A Region-Growing Based Iso-Surface Extraction Algorithm

In this paper, we propose a new region-growing based iso-surface extraction algorithm that can generate high-quality curvature-adaptive semi-regular meshes, preserve sharp features and will extract all the disjoint components of the iso-surface. More importantly, in this paper, we propose a novel normal consistency constraint that ensures the intersection of the Delaunay sphere of the new triangle and the iso-surface is a topological disk, an important property that makes the new algorithm very robust when dealing with large scale of volumetric datasets of complex topology and geometry.
2,5-bis[4-(N-alkylamidino)phenyl]furans as anti-Pneumocystis carinii agents.

The syntheses of 12 new 2,5-bis[4-(N-alkylamidino)phenyl]furans are reported. The interaction of these dicationic furans with poly(dA-dT) and with the duplex oligomer d(CGCGAATTCGCG)2 was determine...
Thermal properties and physical ageing behaviour of tyrosine-derived polycarbonates

Abstract Tyrosine-derived polycarbonates are new carbonate-amide copolymers. These materials have been suggested for use in medical applications, but their thermal properties and their enthalpy relaxation kinetics (physical ageing behaviour) have so far not been evaluated in detail. Since structure-property correlations involving enthalpy relaxation are rarely investigated for biomedical polymers, a series of four tyrosine-derived polycarbonates was used as a model system to study the effect of pendant chain length on the thermal properties and the enthalpy relaxation kinetics. The chemical structure of the test polymers was identical except for the length of their respective pendant chains. This feature facilitated the identification of structure-property correlations. Quantitative differential scanning calorimetry was utilized to determine the thermal properties and to measure enthalpy relaxation kinetics. The glass transition temperature of this family of polymers decreased from 93 to 52 °C when the length of the pendant chain was increased from two to eight carbon atoms. Successive additions of methylene groups to the pendant chain made a fairly constant contribution to lowering the glass transition temperature. For pendant chains of four or more methylene groups, the rate of enthalpy relaxation was independent of the number of methylene groups in the pendant chain. The enthalpy relaxation data were fitted to the Cowie-Ferguson model and the relaxation times obtained were about 90 min. Dynamic mechanical analysis was employed to study the viscoelastic properties. The available observations indicate that the polymers become more flexible with increasing length of the pendant chain. The results suggest that the length of the pendant chain can be used effectively to control important material properties in this series of polymers.
Flow equations for graphite

Abstract In analyzing erosion of graphite at high strain rate (~107 sec−1) and temperature (~4000°C), it is necessary to have some approximation for the constitutive equation. Data for graphite from static and low strain rate experiments were successfully correlated using the equation gekT DbG = C′( σ G ) n which describes the flow of many metals and crystalline ceramics. Solution of the above equation for several specific cases of interest in hypersonic rain erosion at high temperature gives values for flow stress of from 2 to 10 kbar. Changes in temperature of about 500°C or strain rate by a factor 100 shift this value by more than 50%.
Hypnotic medication in the treatment of chronic insomnia: non nocere! Doesn't anyone care?☆

Chronic primary insomnia is a recurrent condition that negatively effects the daily functioning of patients, diminishing the quality of their lives. It is associated with, and in some situations, is a risk factor in both psychiatric (depression) and physical (cardiovascular) illness. Treatment effectiveness has been shown in the short term for both drug (benzodiazepine and benzodiazepine agonists) and behavioral treatment. Expert opinion has strongly advised against long-term drug treatment because of concerns about residual sedative effects, memory impairment, falls, respiratory depression, rebound insomnia, medication abuse, dose escalation, dependency and withdrawal difficulties, and an increased risk of death possibly associated with the current hypnotic medications. Many of these concerns could be made against using these agents at all. Worries about these potential problems are challenged by the widespread clinical practice of using hypnotic drugs long-term without any of these difficulties developing and with patients who feel their sleep and daily function function is improved with the nightly use of their sleeping pill. The ability to mount a randomized, placebo-controlled, parallel group, double-blind trial of hypnotic medication in primary insomnia may not be possible. We may have to develop large systematic clinical databases, a number of case series in effect, to monitor both emergent symptoms and possible clinical effectiveness. There is the additional concern that there is a reluctance to examine the long-term drug treatment of insomnia. This reluctance may reflect a negative moral judgement about treating primary insomnia with drugs, a sort of >>>, rather than just a data based judiciousness.
Coincidence studies of capture and ionization in highly charged I q + -He and U q + -He collisions at medium velocities

Electron capture and ionization processes were investigated for ${\mathrm{I}}^{\mathit{q}+}$-He and ${\mathrm{U}}^{\mathit{q}+}$-He collisions at incident energies 0.1--1.0 MeV/nucleon and for incident charge states q=5--44. Cross sections for single-electron capture, transfer ionization, single ionization, and double ionization were obtained using a projectile-ion recoil-ion coincidence technique. A pronounced interplay among the different electronic processes was observed. Cross sections for single ionization show a rather weak charge-state dependence, in disagreement with recent calculations of McKenzie and Olson [Phys. Rev. A 35, 2863 (1987)]. In a second experiment, photon recoil-ion coincidences were measured to obtain partial cross sections for capture into certain projectile n states. These measurements provide strong evidence that transfer ionization populates lower projectile n states than does single-electron capture. Zero-degree electron spectroscopy, coincident with charge capture for 0.5 MeV/nucleon ${\mathrm{U}}^{30+}$ projectiles revealed that the free electron in transfer ionization is released from the projectile to its continuum and from high-lying Rydberg states of the projectile.
Fast sparse matrix-vector multiplication on GPUs for graph applications

Sparse matrix-vector multiplication (SpMV) is a widely used computational kernel. The most commonly used format for a sparse matrix is CSR (Compressed Sparse Row), but a number of other representations have recently been developed that achieve higher SpMV performance. However, the alternative representations typically impose a significant preprocessing overhead. While a high preprocessing overhead can be amortized for applications requiring many iterative invocations of SpMV that use the same matrix, it is not always feasible -- for instance when analyzing large dynamically evolving graphs. This paper presents ACSR, an adaptive SpMV algorithm that uses the standard CSR format but reduces thread divergence by combining rows into groups (bins) which have a similar number of non-zero elements. Further, for rows in bins that span a wide range of non zero counts, dynamic parallelism is leveraged. A significant benefit of ACSR over other proposed SpMV approaches is that it works directly with the standard CSR format, and thus avoids significant preprocessing overheads. A CUDA implementation of ACSR is shown to outperform SpMV implementations in the NVIDIA CUSP and cuSPARSE libraries on a set of sparse matrices representing power-law graphs. We also demonstrate the use of ACSR for the analysis of dynamic graphs, where the improvement over extant approaches is even higher.
Speech Sound Discrimination of Aphasics when Intersound Interval is Varied

Twenty-four aphasics and 24 age-and-sex matched brain-damaged, but nonaphasic, comparison subjects were assessed in terms of their abilities to discriminate (“same” versus “different”) between 25 s...
A Quadrature-Based Kinetic Model for Dilute Non-Isothermal Granular Flows

A moment method with closures based on Gaussian quadrature formulas is proposed to solve the Boltzmann kinetic equation with a hard-sphere collision kernel for mono-dispersed particles. Different orders of accuracy in terms of the moments of the velocity distribution function are considered, accounting for moments up to seventh order. Quadrature-based closures for four different models for inelastic collision-the Bhatnagar-Gross-Krook, ES-BGK, the Maxwell model for hard-sphere collisions, and the full Boltzmann hard-sphere collision integral-are derived and compared. The approach is validated studying a dilute non-isothermal granular flow of inelastic particles between two stationary Maxwellian walls. Results obtained from the kinetic models are compared with the predictions of molecular dynamics (MD) simulations of a nearly equivalent system with finite-size particles. The influence of the number of quadrature nodes used to approximate the velocity distribution function on the accuracy of the predictions is assessed. Results for constitutive quantities such as the stress tensor and the heat flux are provided, and show the capability of the quadrature-based approach to predict them in agreement with the MD simulations under dilute conditions.
Factor Structure of the Parenting Scale in a Low-Income African American Sample

We evaluated the relative goodness-of-fit of two factor structures of the Parenting Scale (Arnold, O'Leary, Wolf, {&} Acker, 1993) among two samples of low-income African American families. Participants included 271 mother-child dyads from urban and rural areas in the southern and southeastern US, who completed the Parenting Scale along with other measures of parenting style and dyadic relationship. Confirmatory Factor Analyses (CFA) indicated that a two-factor solution, comprising Laxness and Overreactivity dimensions, was the better fit to the data. Some direct evidence for convergent validity was provided by a correlation between the Laxness factor of the Parenting Scale and the Firm/Lax Control subscale of the Children's Report of Parenting Behavior Inventory (CRPBI). Results are discussed in term of Brody and Flor's (1998) “no nonsense” parenting style.
Eye gaze tracking using an RGBD camera: a comparison with a RGB solution

Most commercial eye gaze tracking systems are based on the use of infrared lights. However, such systems may not work outdoor or may have a very limited head box for them to work. This paper proposes a non-infrared based approach to track one's eye gaze with an RGBD camera (in our case, Kinect). The proposed method adopts a personalized 3D face model constructed off-line. To detect the eye gaze, our system tracks the iris center and a set of 2D facial landmarks whose 3D locations are provided by the RGBD camera. A simple onetime calibration procedure is used to obtain the parameters of the personalized eye gaze model. We compare the performance of the proposed method against the 2D approach using only RGB input on the same images, and find that the use of depth information directly from Kinect achieves more accurate tracking. As expected, the results from the proposed method are not as accurate as the ones from infrared-based approaches. However, this method has the potential for practical use with upcoming better and cheaper depth cameras.
A repository for multi-disciplinary computational models and tools

Our motivation for the development of a repository for multi-disciplinary computational models is to help scientists and students apply a non-traditional approach to problem solving and to better understand real-world systems and concepts in science and technology. For example, study of different network protocols within a corporate network using one or more models. This will be accomplished by providing infrastructure and support to researchers and developers. The proposed repository will provide a collection of tools and models required by many researchers either to develop a new model or to carry out enhancements to existing models. This is work in progress.
Micelles Made to Order

Precise control over the molecular structure of cylindrical micelles yields novel supramolecular architectures.
NOX enzymes and the biology of reactive oxygen

Professional phagocytes generate high levels of reactive oxygen species (ROS) using a superoxide-generating NADPH oxidase as part of their armoury of microbicidal mechanisms. The multicomponent phagocyte oxidase (Phox), which has been well characterized over the past three decades, includes the catalytic subunit gp91phox. Lower levels of ROS are seen in non-phagocytic cells, but are usually thought to be 'accidental' byproducts of aerobic metabolism. The discovery of a family of superoxide-generating homologues of gp91phox has led to the concept that ROS are 'intentionally' generated in these cells with distinctive cellular functions related to innate immunity, signal transduction and modification of the extracellular matrix.
Routing in the Dark: Pitch Black

In many networks, such as mobile ad-hoc networks and friend-to-friend overlay networks, direct communication between nodes is limited to specific neighbors. Often these networks have a small-world topology; while short paths exist between any pair of nodes in small-world networks, it is non-trivial to determine such paths with a distributed algorithm. Recently, Clarke and Sandberg proposed the first decentralized routing algorithm that achieves efficient routing in such small-world networks. This paper is the first independent security analysis of Clarke and Sandberg's routing algorithm. We show that a relatively weak participating adversary can render the overlay ineffective without being detected, resulting in significant data loss due to the resulting load imbalance. We have measured the impact of the attack in a testbed of 800 nodes using minor modifications to Clarke and Sandberg's implementation of their routing algorithm in Freenet. Our experiments show that the attack is highly effective, allowing a small number of malicious nodes to cause rapid loss of data on the entire network. We also discuss various proposed countermeasures designed to detect, thwart or limit the attack. While we were unable to find effective countermeasures, we hope that the presented analysis will be a first step towards the design of secure distributed routing algorithms for restricted-route topologies.
REfactor-ing content overhearing to improve wireless performance

Many systems have leveraged the broadcast nature of wireless radios to improve wireless capacity and performance. While conventional approaches have focused on overhearing entire packets, recent designs have argued that focusing on overheard content may be more effective. Unfortunately, key design choices in these approaches limit them from fully leveraging the benefits of overhearing content. We propose a cleaner refactoring of functionality where-in overhearing is realized at the sub-packet payload level through the use of IP-layer redundancy elimination. We show that this dramatically improves the effectiveness of prior overhearing based approaches and enables new designs, e.g., enhanced network coding, where content overhearing can be more effectively integrated to improve performance. Realizing the benefits of IP-layer content overhearing requires us to overcome challenges arising from the probabilistic nature of wireless reception (which could lead to inconsistent state) and the limited resources on wireless devices. We overcome these challenges through careful data structure and wireless redundancy elimination designs. We evaluate the effectiveness of our system using experimentation on real traces. We find that our design is highly effective: e.g., it can improve goodput by nearly 25% and air time utilization by nearly 20%.
A Puzzle about Laws, Symmetries and Measurability

I describe a problem about the relations among symmetries, laws, and measurable quantities. I explain why several ways of trying to solve it will not work, and I sketch a solution that might work. I discuss this problem in the context of Newtonian theories, but it also arises for many other physical theories. The problem is that there are two ways of defining the space-time symmetries of a physical theory: as its dynamical symmetries, or as its empirical symmetries. The two definitions are not equivalent, yet they pick out the same extension. This coincidence cries out for explanation, and it is not clear what the explanation could be.
Group opinion change as a function of circular vs rectangular seating arrangement

Group opinion change was investigated as a function of an organized minority under circular and rectangular table arrangements. It was hypothesized that there would be less opinion change in a circular setting because of the equivalent spatial distance between all group members. The results did not indicate any differences between the two spatial arrangements, but a statistically significant opinion shift occurred under each condition.
Synthesis of ubiquinone and cholesterol in human fibroblasts: regulation of a branched pathway.

Abstract The current studies demonstrate that cultured human flbroblasts utilize mevalonate for the synthesis of ubiquinone-10 as well as for the synthesis of cholesterol. Study of the regulation of this branched pathway was facilitated by incubating the cells with compactin (ML-236B), a competitive inhibitor of 3-hydroxy-3-methylglutaryI coenzyme A reductase, which blocked the formation of mevalonate within the cell. The addition of known amounts of [ 3 H]mevalonate to the culture medium in the presence of compactin permitted the study of the relative rates of mevalonate incorporation into cholesterol and ubiquinone-10 under controlled conditions. When low concentrations of exogenous [ 3 H]mevalonate (10 to 50 μ m ) were added to cells that were provided with exogenous cholesterol in the form of plasma low density lipoprotein (LDL), the cells incorporated the [ 3 H]mevalonate into ubiquinone-10 at a rate that was two- to threefold faster than the incorporation into cholesterol. When the cells were deprived of exogenous LDL-cholesterol, the incorporation of [ 3 H]mevalonate into ubiquinone-10 decreased and the incorporation of [ 3 H]mevalonate into cholesterol increased. As a result, in the absence of exogenous cholesterol more than 60 times as much [ 3 H]mevalonate was incorporated into cholesterol as into ubiquinone-10. Considered together with previous findings, the current data are compatible with a regulatory mechanism in which LDL inhibits cholesterol synthesis in fibroblasts at two points: (1) at the level of 3-hydroxy-3-methylglutaryl coenzyme A reductase, thereby inhibiting mevalonate synthesis, and (2) at one or more points distal to the last intermediate common to the cholesterol and ubiquinone-10 biosynthetic pathways. The latter inhibition allows ubiquinone-10 synthesis to continue in the presence of LDL despite a 98% reduction in mevalonate synthesis.