cssi/SciSciGPT-SciSciNet huggingface dataset:
Purification and Characterization of Adenylate Kinase as an Apparent Adenosine Triphosphate-dependent Inhibitor of Ribonuclease II in Escherichia coli

Highly purified preparations of Escherichia coli RNase II are not inhibited by ATP alone. The reported inhibition of RNase II by ATP has been shown to require a soluble protein from E. coli. This putative ATP-dependent inhibitor of RNase II has been purified approximately 400-fold and identified as adenylate kinase (ATP:AMP phosphotransferase, EC 2.7.4.3). A trivial explanation for the apparent inhibition of RNase II by ATP is thus provided. The 5′-mononucleotide products released from RNA by RNase II are routinely detected by their solubility in alcohol. In the presence of ATP and appropriate nucleoside monophosphate kinases, the 5′-mononucleotides are converted to nucleoside diphosphates which are precipitated to a significant extent in alcohol. These observations contradict both the hypothesis that ATP is an important physiological regulator of RNase II activity in E. coli and the assumption that ATP can function as a specific inhibitor of RNase II in routine RNase V assays performed with crude extracts of E. coli. Our data support the suggestion that the putative RNase V activity in crude extracts of E. coli is a manifestation of previously characterized ribonucleases. Purified adenylate kinase from E. coli appears to be a single polypeptide chain with a molecular weight of approximately 27,000. The enzyme can utilize both ribo- and deoxyribonucleotides as substrates. E. coli adenylate kinase is highly specific for AMP and dAMP, but detectable activity is observed when ATP or dATP is replaced by the variety of ribonucleoside triphosphates tested.
The insulin receptor and its substrate: Molecular determinants of early events in insulin action

Publisher Summary This chapter describes insulin receptor and its substrate. It discusses the two earliest molecular events, binding and activation of the insulin receptor kinase and phosphorylation and subsequent signal transduction by the insulin receptor substrate IRS-1. Defining these events has helped add a whole new dimension to the understanding of insulin action. At the same time, studies defining the molecular events at the end of the insulin action cascade, such as activation of glucose transport and regulation of gene expression, have also begun to clarify the specific components required for these signaling events. Although a black box remains between the early and late events in insulin action, it is becoming smaller.
Transactional Multimedia Banner as Web Access Point

Currently there is an explosively growing amount of back-end services available (e.g., business to business (B2B) commerce, business to consumer (B2C) commerce, and infomercial services) in the Internet. These services are mostly accessible through static HTML web pages at a few specific web portals. Advertising in TV broadcasting has shown that multimedia is a very effective means to present merchandise and attract shoppers. This has been applied to the Web by including animated multimedia banner ads on web pages. However, the issues of coupling interactive browsing, shopping, and secure transactions, e.g., from inside a multimedia banner, have only recently started to being explored. In this paper, we will investigate the feasibility of using interactive multimedia banners as pervasive access point for the B2C, B2B, and infomercial services. We present a system architecture that involves a layer of middleware agents functioning as the bridge between the interactive multimedia banners and back-end services. The findings suggest that the middleware agents can not only convey the B2B services to the individual consumers via multimedia banners, but also simplify the design of the middleware agents by using the standardized B2B application interfaces. As a specific case study, the use of interactive multimedia banners, communicating with a browsing/transaction middleware agent in accessing the catalog and shopping services, over the Internet will be discussed and prototyped. The system architecture under study consists of an interactive multimedia banner (such as a banner-ad, or the display of merchandise in a catalog), a browsing agent, and a transaction agent. Such interactive multimedia banners allow users to browse and buy the merchandise in the e-mall directly from the banner. The browsing agent enables interactive browsing within the banner. The transaction agent interfaces with various e-commerce servers and existing e-malls to complete the transaction securely. We implement a pure Java based shopping system to investigate the feasibility of this architecture. The initial implementation results indicate that this architecture provides a tight and general integration between multimedia browsing and secure transactions and significantly reduces user interactions needed to choose the merchandise and close the transaction.
Variation in predictors of primary care career choice by year and stage of training.

CONTEXT: It is not known whether factors associated with primary care career choice affect trainees differently at different times or stages of medical education. OBJECTIVE: To examine how role models, encouragement, and personal characteristics affect career choice at different stages (medical school vs residency) and periods (1994 vs 1997) of training. DESIGN: A split-panel design with 2 cross-sectional telephone surveys and a panel survey in 1994 and 1997. PARTICIPANTS: A national probability sample of fourth-year students (307 in 1994, 219 in 1997), 645 second-year residents in 1994, and 494 third-year residents in 1997. Of the fourth-year students interviewed in 1994, 241 (78.5%) were reinterviewed as third-year residents in 1997. MAIN OUTCOME MEASURE: Primary care (general internal medicine, general pediatrics, or family medicine) career choice. RESULTS: Having a primary care role model was a stronger predictor of primary care career choice for residents (odds ratio [OR], 18.0; 95% confidence interval [95% CI], 11.2 to 28.8 in 1994; OR, 43.7; 95% CI, 24.4 to 78.3 in 1997) than for students (OR, 6.5; 95% CI, 4.3 to 10.2; no variation by year). Likewise, peer encouragement was more predictive for residents (OR, 5.4; 95% CI, 3.3 to 8.9 in 1994; OR, 16.6; 95% CI; 9.7 to 28.4 in 1997) than for students (OR, 2.1; 95% CI, 1.3 to 3.2; no variation by year). Orientation to the emotional aspects of care was consistently associated with primary care career choice across stages and years of training. CONCLUSIONS: The effect of peer encouragement and role models on career choice differed for students and residents and, in the case of residents, by year of training, suggesting that interventions to increase the primary care workforce should be tailored to stage of training.
Physical activity and reduced risk of colon cancer: implications for prevention

This paper reviews the consistency of the relation between increased physical activity and reduced risk of colon cancer, estimates the potential prevention benefit from increasing population levels of physical activity, and considers social strategies to increase activity levels. The published literature was reviewed systematically and supplemented by MEDLINE searches through March 1997. Studies that reported a measure of physical activity and outcomes of colon cancer or colorectal cancer were included. We excluded the first report of a study that was expanded subsequently by extended follow-up, and any study that did not report the methods for measurement of physical activity. Data were extracted including details on study size, methods of classifying physical activity, and outcomes. A consistent inverse relation was observed such that increased physical activity was associated with reduced risk of colon cancer. About a 50 percent reduction in incidence was observed among those with the highest level of activity across numerous studies that used different measures of activity (occupational or leisure-time activity). This association persisted in studies using multivariate analyses to control for diet and other known or suspected risk factors for colon cancer. Risk reduction was attenuated in those studies that combined colon and rectal cancer. This review indicates that greater attention should be placed on social strategies to increase physical activity as a means of preventing colon cancer.
User-friendly computer programs that calculate radon cancer risks, progeny accumulation and gamma exposure

Publisher Summary A decade of limited success in communicating radon risk information with tools such as nomograms, spread sheets, and perplexing computer programs has indicated the need for a different approach. In these programs, the approach is to document the risk model parameters and formulas used yet mask the technical complexity of the risk calculation engine, thus maintaining scientific rigor behind a user-friendly graphic user interface. This user interface simplifies the input of information and the display of results in easy-to-read forms such as bar graphs that has led to greater acceptance and use of risk-estimating models. Because they combine ease of use and technical accuracy/currency, these programs are useful to a wide range of technical and non-technical users, from individual homeowners to radiation scientists and radon technologists.
The development and implementation of a brief intervention for medically admitted suicide attempt survivors

Abstract Objective The current study endeavored to establish the feasibility and acceptability of a brief intervention for medically admitted suicide attempt survivors. Method Fifty patients admitted to a Level 1 trauma center were recruited following a suicide attempt. The first 10 patients provided information on what constituted usual care, which in turn informed the creation of the intervention manual and research design. The next 10 patients informed refinement of the intervention and research procedures. The final 30 patients were randomized in a pre-post research design to receive the teachable moment brief intervention plus usual care or usual care only. Patients were assessed prior to randomization and 1month later by blinded research assistants. Outcomes included patient satisfaction, readiness to change problematic behaviors, reasons for living, and suicidal ideation. Results Patients rated the brief intervention as "good" to "great" on all items related to client satisfaction. Significant group × time interactions were observed for readiness to change (β=9.02, S.D.=3.73, P= .02) and reasons for living (β=29.60, S.D.=10.22, P =.004), suggesting greater improvement for those patients who received the brief intervention. Conclusions Patients admitted to an acute inpatient medical setting may benefit from a brief intervention that complements usual care by focusing specifically on the functional aspects of the suicide attempt in a collaborative, patient-centered manner.
Regulation of Motivation: Evaluating an Underemphasized Aspect of Self-Regulated Learning.

Self-regulated learning is often described as a function of students' motivation, cognitive strategy use, and metacognition. The purpose of this article is to emphasize regulation of motivation as another important aspect of self-regulated learning. To achieve this goal, a specific conceptual understanding of regulation of motivation is proposed and used to clarify theoretical distinctions between this process and motivation, metacognition, and volition. In addition, the diverse nature of this regulatory activity is established by reviewing evidence showing students' use of several specific strategies for the regulation of motivation. The importance of this process is highlighted by discussing links between these regulatory strategies and indicators of students' motivation, cognitive engagement, and achievement. Finally, a guide for additional research related to the theoretical definition, measurement, development and instruction of strategies for regulating motivation is identified.
A Critique of the Stress-Hyperactivity-Pain Theory of Myogenic Pain

Summary In general, the Ohrbach and McCall article raises several good points and suggests a line of work which needs doing. The major weakness of the paper is the vagueness on how the weakest link in the SHP theory could be tested. In other words, the H-P link is largely ignored and, with the conclusions put forth by this article, they will still not address this link.
A New Training Model: Professional Child Psychology.

School psychology certification implies limited opportunities in so far as it provides for a narrow age range and functioning within a public school setting. Child psychology as a professional model should encompass school psychology training, but broaden its scope to include children of all ages from infancy to adolescence. The school system is only a part of the broader alliance of agencies and institutions servicing the needs of children. The psychologist as a behavioral scientist should not be identified with institutions, but primarily with the subject matter of his training and concern, the child.
The N-terminus of presenilin-2 Increases Single Channel Activity of Brain Ryanodine Receptors Through Direct Protein-Protein Interaction

Presenilin-1 (PS1) and presenilin-2 (PS2) form the catalytic core in gamma-secretase complexes and mutations in these proteins result in aberrant cleavage of amyloid precursor protein leading to accumulation of the beta-amyloid in the brain of familial Alzheimer Disease patients. PS2 possesses a hydrophilic cytoplasmic N-terminal domain (PS2 NTF1-87) dispensable for gamma-secretase activity with physiological functions yet to be determined. The effects of this soluble 87 amino acid fragment of mouse PS2 on single channel activity of mouse brain ryanodine receptors (RyR) were determined. PS2 NTF1-87 application to the cytoplasmic side of the RyR significantly increased single channel activity by favoring higher sublevel openings. The Ca(2+) activation and desensitization ranges for RyRs were unchanged. We demonstrate facilitation of RyR gating by PS2 NTF1-87, which might represent a general mechanism of RyR regulation by presenilins potentially prone to be affected by mutations or external stimuli contributing to the development of neurodegenerative diseases.
Psychotropic drugs and alcohol: Pharmacokinetic and pharmaco dynamic interactions

Abstract This article examines clinically significant interactions between alcohol and psychotropic drugs in occasional and chronic users of alcohol. Enzyme induction by alcohol alters the metabolism of many drugs. In alcoholics, cirrhosis may result in decreased first-pass metabolism, with more drug reaching tissue compartments to exert greater effect than expected. Direct and indirect additive, synergistic, or antagonistic interactions are reviewed in relation to the major categories of psychotropic drugs.
Preliminary results of experiment luxembourg

Abstract A cross modulation experiment was conducted at College, Alaska for a few weeks during 1960. From the results, it was possible to deduce collision frequencies and electron densities at rather low altitudes. At 48 km the electron density was found to be 12/cm 3 .
Formation and crystal structure of MeIr(CO)(PPh3)2(MeCO2CHCHCO2Me). Comparison of the structures of analogous alkene and alkyne complexes

Abstract The complex MeIr(CO)(PPh 3 ) 2 (MeCO 2 CHCHCO 2 Me), synthesized from trans -MeIr(CO)(PPh 3 ) 2 and dimethyl maleate, crystallizes in the centrosymmetric monoclinic space group P 2/ n with a 13.997(5), b 17.878(5), c 15.709(4) A, β 91.00(2)°, V 3930(2) A 3 and Z = 4. X-ray data (Mo- K α , 2θ 4.5–45.0°) were collected with a Syntex P2 1 automated four-circle diffractometer; the structure was solved and converged with R 5.5% for all 5069 unique reflections and R 4.3% for those 4343 data with | F o | > 3σ(| F o |). The iridium(I) center has a distorted trigonal bipyramidal geometry with the Me and CO ligands occupying axial sites (Ir-Me(1) 2.159(8), IrCO 1.907(8) A. The MeCO 2 CHCHCO 2 Me ligand is bonded in η 2 fashion to the iridium, with its coordinated double bond parallel to the equatorial plane. Bonds to the equatorial ligands are IrP(1) 2.344(2), Ir-P(2) 2.376(2) and Ir-(center of olefin) 2.017 A. The observed ligand configuration is different from that for MeIr(CO)(PPh 3 ) 2 (MeCO 2 CCCO 2 Me) which has axial Me and PPh 3 ligands in its thermodynamically stable isomer.
A 33-year-old woman with burning and blistering of perivaginal tissue following sexual intercourse.

History of Present Illness A 33-year-old woman who had been having sexual intercourse with her fiance for 6 months without discomfort subsequently began to experience adverse reactions. Symptoms included redness, swelling, pain, and burning of the vulva and within her vagina. The onset of symptoms was several hours after sexual intercourse and was accompanied by blistering and erosion of perivaginal tissue and a slightly bloody vaginal discharge. She denied symptoms of localized or generalized pruritus, urticaria, or respiratory or gastrointestinal distress. These episodes, numbering 2 or 3 before seeking physician assistance and totaling 4 or 5 in all, were not noted to progress in severity and occurred only after coitus. The signs and symptoms resolved spontaneously without treatment during a 6to 7-day period. The patient denied adverse reactions on other areas of skin or oral mucosa exposed to semen. She has a monogamous relationship with her fiance and never has had adverse reactions with prior sexual partners. Condoms were used. She denied the use of tampons and intravaginal medications or devices, including sponges and diaphragms. The patient was first evaluated by her gynecologist. Pelvic examination performed during an episode was difficult secondary to pain and discomfort. Latex examination gloves were used. She was treated empirically with antiherpetic medication and later with topical steroids and antibiotics. Despite these treatments, the patient continued to have adverse reactions after sexual intercourse with her fiance. Current Medications The patient was not taking any medications at the time of presentation.
THE EFFECT OF MIXED FILLER SIZES ON THE FIBER DIAMETER OF ELECTROSPUN BUTYL RUBBER FORMULATIONS

Abstract Electrospinning of thermosetting elastomers is a method for developing nonwoven membranes with a microporous structure for use in dynamic applications (i.e., stretchable). These membranes ...
High integrity titanium aluminide compacts

Abstract Titanium aluminide alloys are important candidates for applications in advanced gas turbine engines and high mach airframes. Compared with conventional titanium alloys, the aluminides are lower in density, higher in modulus, and have better high temperature oxidation and creep resistance. Also, substantial weight savings may be realized by replacing engine components currently made of nickel-based superalloys with titanium aluminides. But limited room temperature ductility is currently one of the major obstacles to the commercial implementation of titanium aluminide products.
Efficiency of labriform swimming in the bluegill sunfish (Lepomis macrochirus)

Bluegill sunfish (Lepomis macrochirus) swim in the labriform mode at low speeds, generating lift and thrust by beating their pectoral fins. The maximal power output available from the two largest pectoral fin adductor and abductor muscles, constituting half of the total pectoral girdle muscle mass, was measured in vitro and used to estimate the muscle mechanical power output during maximal labriform swimming (Pmech; 0.15-0.21 W kg(-1) body mass). Respirometry was used to estimate the total metabolic power input (Ptotal; 0.95 W kg(-1) body mass) and the metabolic power available to the active muscle mass (Pmuscle; Ptotal minus standard metabolic rate, 0.57 W kg(-1) body mass) at this swimming speed. Drag measurements made on towed, dead fish were used to estimate the mechanical power required to overcome body drag (Pdrag; 0.028 W kg(-1) body mass). Efficiency estimates based on these data fell into the following ranges: overall swimming efficiency (etagross=Pmech/Ptotal), 0.16-0.22; muscle efficiency (etamuscle=Pmech/Pmuscle), 0.26-0.37; and propeller efficiency (etaprop=Pdrag/Pmech), 0.15-0.20. Comparison with other studies suggests that labriform swimming may be more efficient than swimming powered by undulations of the body axis.
Treatment of Hematologic Neoplasms with New Immunomodulatory Drugs (IMiDs)

Thalidomide and its derivatives represent a new class of antineoplastic drugs (IMiDs), which has been especially effective in certain hematologic malignancies. These agents have anti-inflammatory, antiangiogenic, and immunomodulatory properties, and target tumor cells by direct cytotoxicity and indirectly by interfering with several components of the bone marrow microenvironment [1]. Thalidomide analogs that retain antitumor activity equal to or greater than the parent compound, but with less toxicity, have been developed [2]. This paper summarizes what is known about the mechanisms of action of these agents, and recent clinical results. The data suggest that thalidomide analogs will play a major role in the management of certain hematologic neoplasms in the near future.
Microvalve for Fuel Cells and Miniature Gas Chromatographic System

Microvalves are important for fluid control in a variety of applications, ranging from miniaturized chemical analysis systems, to precision manufacturing and miniature fuel cells. MEMS technology provides the opportunity to miniaturize valves that work with smaller sample volume, operate rapidly with low power and can potentially be integrated with other components on a single chip. A review of actuators for microvalves is provided, including electrostatic, magnetic, piezoelectric, thermal, shape memory alloy and hydrogel. The design and simulation of a magnetic latching microvalve is provided as a case study. The fabrication by surface micromachining with low temperature, potentially CMOS compatible processing is given.
Effects of genotype on in vitro culture in the genus Brassica

Abstract Callus growth and plant regeneration from callus were studied for 6 species of Brassica differing in chromosome number and ploidy level and for 17 cultivars of B. oleracea having constant chromosome number and ploidy level. Callus was initiated from young hypocotyl explants and was maintained on media supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), naphthaleneacetic acid (NAA), kinetin and coconut milk (CM). The rate of callus growth and the appearance of this tissue depended upon both the genotype examined and the growth medium. Variability in callus growth rate within B. oleracea was as great as that between the species of Brassica. Callus growth was less vigorous on a medium containing CM and high levels of 2,4-D than on a medium lacking CM and with a low concentration of 2,4-D; however, 2,4-D was shown to be necessary for callus formation. Organogenetic response of calluses tested on two regeneration media demonstrated intra-varietal variability as great as the variability between species. Rate of root and shoot organogesis was enhanced by a 1-week exposure to callus medium lacking 2,4-D.
Consequences of Disrupting the Dystrophin-Sarcoglycan Complex in Cardiac and Skeletal Myopathy

Mutations that disrupt the dystrophin glycoprotein complex lead to plasma membrane instability of cardiomyocytes and skeletal muscle myofibers. Instability of the plasma membrane leads to degeneration largely due to activation of a necrotic process in these disorders. In response to ongoing degeneration, skeletal muscle exhibits robust regeneration while in cardiac muscle regeneration is not obvious. The dystrophin complex is concentrated along the plasma membrane in costameric structures that correspond to the Z bands of sarcomeres, thus positioning the dystrophin complex to transmit force between the sarcomere and the plasma membrane to the extracellular matrix. Although it is apparent that this position is important for perpendicular force transmission, it is clear that the dystrophin complex also fulfills signaling roles. Nitric oxide synthase and stress-induced signaling cascades are activated to participate in protection but may also contribute to pathology.
Paradigm shifts in clinical trials enabled by information technology.

The use of the world wide web for clinical trials changes the processes of performing clinical research in several fundamental ways. Greatly improved security, monitoring capability, and accuracy and timeliness of study conduct can be achieved while lowering cost. Data quality is enhanced while co-ordinating centre effort is reduced. The web provides a natural environment for linking the various components of clinical research, leading to new levels of simplicity and efficiency. It also enhances opportunities for recruitment of study investigators and patients. Other information technology tools and databases can be used to assist in this regard as well. Web-based trials change the relationship of the investigator site to the study and the site to the co-ordinating centre. Different roles and responsibilities lead to simplified processes and more and higher quality data. Many standard co-ordinating centre activities, such as randomization, protocol implementation and amending, document tracking, adverse event reporting, site monitoring, report generation and data analysis are all fundamentally changed in a web-based trial. Opportunities are enhanced to identify potential investigators and support their successful study conduct. As the role of investigator sites is changed in web-based research, more primary care medical providers can be attracted to research, providing more typical patients to studies than those sometimes available through more traditional research sites, especially those at academic study sites. Other activities can now be co-ordinated electronically with the advent of the web. The Institutional Review Board (IRB) can use online tools to control investigator participation, resulting in improved study efficiency and patient safety. A web-based research pharmacy provides tremendous efficiencies in managing and distributing study medications. Financial payments to the sites can be performed and recorded electronically, or even administered based on timeliness and quality of the data. Our early experience with web-based trials indicates that there can be tremendous gains in study efficiency and accuracy by restructuring processes, roles and responsibilities through a comprehensive centralized, web-based trial. The future appears bright for web-based clinical trials.
Differences in oxides on large-and small-grained 304 stainless steel

The oxides formed on large-grained (∼40 °m) and small-grained (∼4 μm) 304 stainless steel oxidized in air at 800 °C have been examined and compared by Auger electron spectroscopy to learn more about the role of grain boundaries in the oxidation of the materials. For vacuum preannealed specimens, relatively thick iron oxides formed over the grains and thin, chromium-rich oxides formed over grain boudaries of large-grained material. The oxide formed over the entire surface of the small-grained material was a thin chromium-rich layer similar to that formed over grain boundaries of the large-grained samples. The oxidation of both small- and large-grained samples was consistent with selective formation of Cr2O3 at grain boundaries followed by a lateral diffusion of Cr and spreading of Cr2O3. A protective Cr2O3 layer formed readily on small-grained material but not on large-grained material. In contrast to the differences in oxide morphology for small- and large-grained preannealed specimens, oxide morphologies were similar for small- and large-grained material when the outer surface layer was removed by polishing after annealing and before oxidation tests. Surface differences, not adequately defined by Auger and SEM studies, caused marked changes in oxide morphologies for large-grained material. The difference in oxidation behavior before and after polishing was attributed to enhanced oxidation at grain boundaries during the vacuum preannealing treatment and to differences in defect concentrations in the surface region.
Microdosimetric considerations in the use of the boron neutron capture reaction in radiation therapy

This thesis attempts to further the understanding of the dosimetric and microdosimetric aspects of the boronneutron capture reaction (BNCR) in two distinct radiation therapy modalities, the conventional BNCT and boronneutron capture enhanced fast neutron therapy (BNCEFNT). The absorbed dose in these two modalities consists of contributions from gamma rays,neutrons and the neutron capture reactions in tissue including the BNCR. The use of low pressure tissue equivalent proportional counters for the dual purpose of dosimetry and microdosimetry of the complex radiation fields used in BNCT and BNCEFNT has been thoroughly investigated. Commercially obtained, paired 1/2″ Rossi type LET counters (with and without boron-10 in the A-150 TEP wall) were used in this work. The counters were dose calibrated by positioning the proton edge in the measured spectra at a lineal energy of 150 keV/micrometer. Using this paired counter technique, the gamma, neutron and BNCR dose components in different radiation fields were resolved. Experimental results indicate that this technique is well suited for the dosimetry of BNCT and BNCEFNT fields. The uncertainties in these dose measurements are smaller than, or comparable to those achieved using conventional techniques. The microdosimetric spectra measured by the proportional counters have been found to be useful for evaluating the quality of these radiation fields.
Delineation of the effects of water and oxygen on the degradation of organic photovoltaic devices

Performance degradation is one of the most important metrics for the evaluation of solar cells. In this paper we show that water is the primary species determining the degradation rate of electrical properties of Al/Ca/P3HT:PC61BM/PEDOT:PSS/ITO photovoltaic cells. This is accomplished by varying the diffusion rate of reactive species (oxygen, water) present in air through solar cell encapsulation with polyethylene terephthalate (PET), Kapton and silica glass.
Aromatic polyether, -ketone, -sulfones as laminating resins. XII. Derivatives of 2,2′-diphenylethynyldiphenyl which cure by an intramolecular cyclization

Polymers made from 2,2′-diiododiphenyl-4,4′-dicarbonyl dichloride, diphenyl ether, and isophthaloyl chloride have been made and converted to the 2,2′-diphenylethynyl derivatives. Introduction of units of isophthaloyl chloride reduced the melting point of these polymers to about 200°C, and they could then be cured by heating. A good glass laminate was prepared and cured from one of the polymers.
Scattering and depolarization by large conducting spheres with rough surfaces.

The scattering cross sections for large finitely conducting spheres with rough surfaces are determined for optical frequencies using the full wave approach. For the roughness scales considered the scattering cross sections differ significantly from those of smooth conducting spheres. Several illustrative examples are presented, and the results are compared to earlier solutions to the problem.
Participatory Simulations: Building Collaborative Understanding Through Immersive Dynamic Modeling

This article explores a new way to help people understand complex, dynamic systems. Participatory simulations plunge learners into life-sized, computer-supported simulations, creating new paths to scientific understanding. By wearing small, communicating computers called Thinking Tags, students are transformed into players in a large-scale microworld. Like classic microworlds, participatory simulations create a scenario, mediated by a set of underlying rules, that enables inquiry and experimentation. In addition, these new activities allow students to "dive into" a learning environment and directly engage with the complex system at hand. This article describes and analyzes a set of participatory simulations that were conducted with a group of high school biology students. The students' experiences are tracked from their initial encounter with an immersive simulation through their exploration of the system and final description of its underlying rules. The article explores the educational potential of part...
Adhesive Dynamics Simulations of the Shear Threshold Effect for Leukocytes

Many experiments have measured the effect of force on the dissociation of single selectin bonds, but it is not yet clear how the force dependence of molecular dissociation can influence the rolling of cells expressing selectin molecules. Recent experiments using constant-force atomic force microscopy or high-resolution microscopic observations of pause-time distributions of cells in a flow chamber show that for some bonds, the dissociation rate is high at low force and initially decreases with force, indicating a catch bond. As the force continues to increase, the dissociation rate increases again, like a slip bond. It has been proposed that this catch-slip bond leads to the shear threshold effect, in which a certain level of shear rate is required to achieve rolling. We have incorporated a catch-slip dissociation rate into adhesive dynamics simulations of cell rolling. Using a relatively simple model for the shear-controlled association rate for selectin bonds, we were able to recreate characteristics of the shear threshold effect seen most prominently for rolling through L-selectin. The rolling velocity as a function of shear rate showed a minimum near 100 s−1. Furthermore, cells were observed to roll at a shear rate near the threshold, but detach and move more quickly when the shear rate was dropped below the threshold. Finally, using adhesive dynamics, we were able to determine ranges of parameters necessary to see the shear threshold effect in the rolling velocity. In summary, we found through simulation that the catch-slip behavior of selectin bonds can be responsible for the shear threshold effect.
Anomalous chain diffusion in polymer nanocomposites for varying polymer-filler interaction strengths

Anomalous diffusion of polymer chains in a polymer nanocomposite melt is investigated for different polymer-nanoparticle interaction strengths using stochastic molecular dynamics simulations. For spherical nanoparticles dispersed in a polymer matrix the results indicate that the chain motion exhibits three distinct regions of diffusion, the Rouse-like motion, an intermediate subdiffusive regime followed by a normal Fickian diffusion. The motion of the chain end monomers shows a scaling that can be attributed to the formation of strong 'networklike' structures, which have been seen in a variety of polymer nanocomposite systems. Irrespective of the polymer-particle interaction strengths, these three regimes seem to be present with small deviations. Further investigation on dynamic structure factor shows that the deviations simply exist due to the presence of strong enthalpic interactions between the monomers with the nanoparticles, albeit preserving the anomaly in the chain diffusion. The time-temperature superposition principle is also tested for this system and shows a striking resemblance with systems near glass transition and biological systems with molecular crowding. The universality class of the problem can be enormously important in understanding materials with strong affinity to form either a glass, a gel or networklike structures.
Calculated ambiguity: Nuclear weapons and the gulf war

(1996). Calculated ambiguity: Nuclear weapons and the gulf war. The Washington Quarterly: Vol. 19, No. 4, pp. 2-18.
Heterogeneous memory management for 3D-DRAM and external DRAM with QoS

This paper presents an innovative memory management approach to utilize both 3D-DRAM and external DRAM (ex-DRAM). Our approach dynamically allocates and relocates memory blocks between the 3D-DRAM and the ex-DRAM to exploit the high memory bandwidth and the low memory latency of the 3D-DRAM as well as the high capacity and the low cost of the ex-DRAM. Our simulation shows that in workloads that are not memory intensive, our memory management technique transfers all active memory blocks to the 3D-DRAM which runs faster than the ex-DRAM. In memory intensive workloads, our memory management technique utilizes both the 3D-DRAM and the ex-DRAM to increase the memory bandwidth to alleviate bandwidth congestion. Our approach supports Quality of Service (QoS) for “latency sensitive”, “bandwidth sensitive”, and “insensitive” applications. To improve the performance and satisfy a certain level of QoS, memory blocks of different application types are allocated differently. Compared to the scratchpad memory management mechanism, the average memory access latency of our approach decreases by 19% and 23%, while performance improves by up to 5% and 12% in single threaded benchmarks and multi-threaded benchmarks respectively. Moreover, using our approach, applications do not need to manage memory explicitly like in the scratchpad case. Our memory block relocation comes with negligible performance overhead, particularly for applications which have high spatial memory locality.
Cytologic imprints of giant atypical bronchopulmonary carcinoid tumor of the lung with extensive oncocytic component.

Bronchopulmonary carcinoid tumors are found in less than 2 of 100,000 people yearly and comprise approximately 1–2% of all lung neoplasms. They are usually diagnosed in the fifth decade of life and occur more frequently in women. Most are central and endobronchial in location. The symptoms presented are those associated with bronchial obstruction, such as coughing, wheezing, and dyspnea. Over one-third of patients are asymptomatic and have an incidentally detected peripheral pulmonary nodule. Diagnosis is usually made by bronchoscopy with bronchial brushings or biopsy. We present the cytologic imprint findings of a case of a 66-year-old man with an atypical giantbronchopulmonary carcinoid with extensive oncocytic component, who underwent a total right pneumonectomy. Diagn. Cytopathol. 2008. © 2008 Wiley-Liss, Inc.
Isoelectric focusing of brain adenylate cyclase

Abstract Mouse brain adenylate cyclase has been solubilized with Lubrol PX and separated by isoelectric focusing on polyacrylamide gels. The enzyme activity has been measured with a sensitive assay isolating cyclic AMP from Dowex and alumina columns. The technique allows a one-step analysis of this membrane enzyme from a heterogeneous sample within 6 hr.
Characterization of DNA methylation and its association with other biological systems in lymphoblastoid cell lines

Lymphoblastoid cell line (LCL) is a common tool to study genetic disorders. However, it has not been fully characterized to what degree LCLs preserve the in vivo status of non-genetic biological systems, such as DNA methylation and gene transcription. We previously reported that DNA methylation in LCLs is highly variable in a data set of ~27,000 CpG dinucleotide sites around transcription start site (TSS) and 63 human subjects including healthy controls and probands of genetic disorders. Disease-causing mutations are linked to differential methylation at some CpG sites, but account for a small proportion of the total variance. In this study, we repeated the experiments to ensure that the high variance is not due to technical error and scrutinized the characteristics of DNA methylation and its association with other biological systems. Using sequence information and ChIP-seq data, we conclude that local CpG density and histone modifications not only correlate to baseline methylation level, but also affect the direction of methylation change in LCLs. Integrative analysis of gene transcription and DNA methylation data of the same subjects shows that medium or high methylation around TSS blocks the transcription while low methylation is a necessary, but not sufficient condition of downstream gene transcription. We utilized epigenetic information around TSS to predict active gene transcription via logistic regression models. The multivariate model using DNA methylation, eight histone modifications, and two regulatory protein complexes (CTCF and cohesin) as predictors has better performance (accuracy=95.1%) than any univariate models of single predictors. Linear regression analysis further shows that the transcriptional levels predicted by epigenetic markers have significant correlation to microarray measurements (p=2.2e-10). This study provides new insights into the epigenetic systems of LCLs and suggests that more specifically designed experiments are needed to improve our understanding on this topic.
ARE THERE AGE-RELATED PROCESSING DIFFERENCES IN SEMANTIC PRIMING? '

Behavioral and electrophysiological assessments of small samples of young and elderly subjects (ns = 10) performing semantic priming tasks showed no age-related slowing in semantic priming.
Real-Time Seismic Monitoring of the New Cape Girardeau Bridge and Preliminary Analyses of Recorded Data: An Overview

Abstract This paper introduces the state-of-the-art seismic monitoring system implemented for the 1,206-m-long (3,956 ft) cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (Missouri), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811 and 1812 New Madrid earthquakes. The real-time seismic monitoring system for the bridge includes a broadband network consisting of superstructure and free-field arrays and comprises a total of 84 channels of accelerometers deployed on the superstructure (towers and deck), pier foundations (caisson tops and bents), and in the vicinity of the bridge (e.g., free-field, both surface and downhole). The paper also introduces the high-quality response data obtained from the broadband network that otherwise would not have been possible with older instruments. Such data is aimed to be used by the owner, researchers, and engineers to (1) assess the performance of the bridge, (2) check design parameters, including the comparison of dy...
The Promise and Pitfalls of Using Imprecise School Accountability Measures

In recent years, most states have constructed elaborate accountability systems using school-level test scores. However, because the median elementary school contains only 69 children per grade level, such measures are quite imprecise. We evaluate the implications for school accountability systems. For instance, rewards or sanctions for schools with scores at either extreme primarily affect small schools and provide weak incentives to large ones. Nevertheless, we conclude that accountability systems may be worthwhile. Even in states with aggressive financial incentives, the marginal reward to schools for raising student performance is a small fraction of the potential labor market value for students.
Smartphone Detection of Escherichia coli From Field Water Samples on Paper Microfluidics

Smartphone detection of Escherichia coli from field water samples is successfully demonstrated using paper microfluidics. A three-channel paper chip is designed and fabricated, with a negative control channel preloaded with bovine serum albumin (BSA)-conjugated beads and two E. coli detection channels preloaded with anti-E. coli-conjugated beads, for low- and high-concentration detection. Field water samples are introduced to the paper chip by dipping or pipetting, and the antigens from E. coli travel through the paper fibers by capillary action while the dust/soil or algae particles are effectively filtered. Antibody-conjugated beads, confined within the paper fibers, immunoagglutinate in the presence of E. coli antigens, while BSA-conjugated beads do not. The extent of immunoagglutination is quantified by evaluating Mie scatter intensity from the digital images taken at an optimized angle and distance using a smartphone. The assay results show excellent agreement with the MacConkey plate results, i.e., the count of viable E. coli. The scatter simulation procedure is introduced to substitute for experimental optimization, such that the proposed method can be easily adapted to the other types of samples. A smartphone application is developed, incorporating the internal gyroscope of a smartphone, to allow the user to position the smartphone at an optimized angle of scatter detection. The detection limit is single-cell-level and the total assay time is 90 s.
Vitamin-D Synthesis and Metabolism after Ultraviolet Irradiation of Normal and Vitamin-D-Deficient Subjects

THE beneficial effects of sunlight in the treatment and prevention of rickets and osteomalacia have been recognized for over 60 years.1 However, little is known about the sequential changes in the serum concentrations of vitamin D and its metabolites after a single exposure to sunlight. In an attempt to understand these events, we monitored changes in serum concentrations of vitamin D and its metabolites, 25-hydroxyvitamin D (25-OH-D) and 1,25-dihydroxyvitamin D (1,25-(OH)2-D), over a three-week period in normal subjects and vitamin-D-deficient patients, before and after whole-body exposure to various doses of ultraviolet radiation (UVR). We found that exposure to . . .
Preventing ventricular fibrillation by flattening cardiac restitution

Ventricular fibrillation is the leading cause of sudden cardiac death. In fibrillation, fragmented electrical waves meander erratically through the heart muscle, creating disordered and ineffective contraction. Theoretical and computer studies, as well as recent experimental evidence, have suggested that fibrillation is created and sustained by the property of restitution of the cardiac action potential duration (that is, its dependence on the previous diastolic interval). The restitution hypothesis states that steeply sloped restitution curves create unstable wave propagation that results in wave break, the event that is necessary for fibrillation. Here we present experimental evidence supporting this idea. In particular, we identify the action of the drug bretylium as a prototype for the future development of effective restitution-based antifibrillatory agents. We show that bretylium acts in accord with the restitution hypothesis: by flattening restitution curves, it prevents wave break and thus prevents fibrillation. It even converts existing fibrillation, either to a periodic state (ventricular tachycardia, which is much more easily controlled) or to quiescent healthy tissue.
Immittance characterization of tapered multiple layer RC lines

Abstract A model of a class of multiple layer distributed RC structures is derived from Maxwell's equations thus avoiding the usual assumption of an incremental element. Explicit formulae for the immittance parameters are presented and the effects of the structure on these parameters are studied. The immittance parameters are formulated in terms of initial value problems and are, therefore, well defined for determination by numerical techniques. Finally, some relations existing between multiple layer-pair RC structures and networks of single layer-pair RC structures are derived and explored.
Caffeine protects against combined paraquat and maneb-induced dopaminergic neuron degeneration

Abstract Environmental exposures suspected of contributing to the pathophysiology of Parkinson's disease (PD) include potentially neurotoxic pesticides, which have been linked to an increased risk of PD. Conversely, possible protective factors such as the adenosine antagonist caffeine have been linked to a reduced risk of the disease. Here we assessed whether caffeine alters dopaminergic neuron loss induced by exposure to environmentally relevant pesticides (paraquat and maneb) over 8 weeks. The number of nigral neurons positive for tyrosine hydroxylase immunoreactivity (TH+) was assessed using stereological methods and found to be significantly reduced (to 60% of control) by combined pesticide treatment. Caffeine at 20 mg/kg significantly reduced TH+ neuron loss (to 85% of the respective control). The results demonstrate the neuroprotective potential of caffeine in a chronic pesticide exposure model of model of PD.