cssi/SciSciGPT-SciSciNet huggingface dataset:
Aging Effects on Accommodation and Outflow Facility Responses to Pilocarpine in Humans

Objective: To determine the relationships among age, outflow facility, and refractive and facility responses to pilocarpine in humans. Methods: Refraction, intraocular pressure, and outflow facility were determined in 30 normal volunteers aged 20 to 75 years, by coincidence refractometry, applanation tonometry, and Schiotz tonography, respectively, before and 1 hour after a 30-μL drop of 2% or 6% pilocarpine. Simple regression of baseline facility, postpilocarpine facility, and facility change, on age and refractive change singly and jointly, was performed. Stepwise regression models and graphic conditioning plots were used to determine, for each facility variable, its relationship to age or refractive change specifically. Results: Baseline outflow facility and maximum pilocarpine-induced refractive change (ie, accommodation) declined with age, but the decrease in intraocular pressure and the facility response to pilocarpine did not. After adjusting for age, for baseline facility, there was no further relationship to 6% pilocarpine-induced accommodation, and a slight residual relationship to 2% pilocarpine-induced accommodation. After adjusting for both 2% or 6% pilocarpine-induced accommodation, the relationship to age was still significant. The facility increase after 2% or 6% pilocarpine did not depend on age and/or accommodative amplitude. Conclusions: In humans, as previously described in rhesus monkeys, an age-related loss of ciliary muscle mobility may compromise the basal function of the trabecular meshwork. However, unlike monkeys, humans exhibit no loss of the intraocular pressure or outflow facility response to pilocarpine with age.
Structure-function relationships in nicotinic acetylcholine receptors.

Abstract 1. 1. A combination of molecular, biochemical electrophysiological and immunological approaches has begun to resolve some of the questions about structure-function relationships of nicotinic acetylcholine receptors (AchRs). 2. 2. Current structural studies suggest that models of the subunits which propose four transmembrane domains are correct. 3. 3. It is also probable that the carboxy termini of the subunits are extracellular, while the putative amphpathic helix is intracellular. 4. 4. Electrophysiological and ligand-binding experiments suggest that the m2 region forms the wall of the ion channel. 5. 5. We have isolated clones from PC12 and rat brain cDNA libraries which we have shown, by functional expression, code for members of a gene family of nicotinic acetylcholine receptor subunits. 6. 6. In situ hybridization studies have shown that the neuronal receptor subunit mRNAs are expressed in the mammalian central nervous system. 7. 7. The muscle and neuronal nicotinic AchR subtypes we have expressed show differences in their pharmacological properties. 8. 8. The isolation and identification of clones which code for receptors and voltage-activated ion channels will help in the understanding of a variety of disease states and assist in the design of drugs which are specific for unique molecular targets.
Constructing content and delimiting choice: International coverage of KAL Flight 007

For more than two decades, international debate over a New World Communication and Information Order has called attention to the question of whether or not newspapers around the world are limited by the alleged dominance of the international news flow by the Western media. Looking at how six newspapers from around the world covered the 1983 downing of KAL Flight 007 by the Soviet Union, we find that papers are in fact able to shape their coverage of major international events through their choice of providers, their selection and interpretation of subjects and facts, and their use of headlines to emphasize and frame information. Thus, newspapers can delimit choice to suit their own needs and goals.
A Rod-Shaped Guest Leads to Architectural Isomerism in a Multicomponent Crystalline Framework Based on a Resorcin[4]arene

Cocrystallization of C-methylcalix[4]resorcinarene 1 with 4,4‘-bipyridine 2 in the presence of 4-bromobiphenyl (4-brbp) yields a molecular solid, of composition 3d·(4-brbp), [where 3d = 1·2(2)], in which 1 assembles with 2 to form a one-dimensional hydrogen-bonded polymer 3d that includes two copies of the biphenyl, within elliptical cavities of dimensions ∼ 11 × 7 × 6 A, as guests. The framework 3d represents a third architectural isomer of three previously reported supramolecular isomers of the parent material 3.
The molecular mystique of tetrodotoxin

In many respects tetrodotoxin (TTX) is the quintessential natural toxin. It is unequivocally toxic to mammals with LD(50) values for mice in the range of 10 μg/kg (intraperitoneal), 16 μg/kg (subcutaneous), and 332 μg/kg (oral) (Kao, 1966). Its biothreat status is recognized by its listing as a "Select Agent" by the US Department of Health and Human Services which includes regulated agents "determined to have the potential to pose a severe threat to both human and animal health" (http://www.selectagents.gov/). It has a well-defined cellular target (i.e., NaV channels) and pharmacological mode of action (i.e., block of nerve and muscle action potentials), and it is an indispensable chemical tool in neuroscience. It is widely distributed in marine and terrestrial ecosystems where it plays a role in the chemical ecology of predator-prey relationships and drives evolutionary selection of TTX-resistance (Hanifin, 2010; Williams, 2010; Zimmer and Ferrer, 2007). Lastly, TTX has acquired a certain mystique in scientific lore attributable to many fascinating aspects of its natural history and molecular interactions as presented in selected summary below. Additional information may be found in other excellent reviews (Fozzard and Lipkind, 2010; Kao, 1966; Lee and Ruben, 2008; Narahashi, 2001, 2008).
Changes in medicare reimbursement: impact on therapy for benign prostatic hyperplasia.

Medicare spending accounts for 17% of all health spending and therefore exerts a significant influence on health care spending policies. Medicare policies such as Diagnostic Related Groups and the Resource Based Relative Value System have resulted in profound changes in health care delivery in the United States. These resource-allocation methods are one of the major sources of controversies between managers, doctors, politicians, and social scientists. Financial disincentives associated with these resourceallocation policies have effectively rationed select therapies, particularly transurethral resection of the prostate (TURP). As a consequence, TURP, once the second most common surgical procedure billed to Medicare and comprising 38% of major surgical procedures performed by urologists, is increasingly challenged by medical therapy and minimally invasive surgical therapies that may be associated with lower efficacy and durability. This article examines the history of Medicare policies and their influence on TURP.
Taxanes and other microtubule stabilising agents

Paclitaxel (Taxol®) and docetaxel (Taxotere®) are relatively new drugs used in cancer therapy and have shown great promise in the treatment of a variety of cancers. The taxane therapy, however, encounters two major problems. One problem is the low solubility of both paclitaxel and docetaxel; the second problem is multi-drug resistance. In the patent literature from 1995 - 1997 these two problems have been the main focus of research in the taxane field. Numerous taxoids have been disclosed with improved solubility, mainly by acylation of the C-2′ and C-7 hydroxyls. To reduce the multi-drug resistance susceptibility of the drugs, alterations on the taxane core and the phenylisoserine ring have been made. The patent literature also reports the discovery of new classes of compounds (epothilones, discodermolides, eleutherobins and sarcodictyins) that are structurally dissimilar from taxanes but have microtubule stabilisation activity and are potent inhibitors of cancer cells and paclitaxel-resistant cancer cells.
Half-wave cavity vertical-cavity surface-emitting lasers with native oxide/GaAs lower distributed Bragg reflectors

ABSTRACT Data are presented on half-wave cavity vertical cavity surface emitting lasers using bothoxide confmement and high contrast upper and lower distributed Bragg reflectors. Sixpairs of MgF/ZnSe distributed Bragg reflectors make up the top mirror and 1 1 pairs of AlxOy/GaAs DBRs make up the lower DBR. The oxide layer thickness in the AlxOy/GaAs DBRs is less than a quarter-wavelength in order to reduce strain on thequantum well active region. The lasing characteristics of device sizes ranging from 7im to 1j.tm are analzyed through spectral data, far field radiation patterns and lasing threshold. Keywords: semiconductor laser, vertical-cavity surface-emitting laser, native oxide,native oxide confinement, optical microcavity lasers, high-contrast distributed Braggreflector 2. INTRODUCTION Realizing ultralow lasing threshold in vertical-cavity surface-emitting lasers (VCSELs) is important for reduction of power consumption in highly parallel optical interconnects, and is a topic of interest in understanding the fundamental limits of operation
A Meta-Analytic Structural Model of Dispositonal Affectivity and Emotional Labor

The exponential growth of the service economy has increased the attention that organizational researchers have paid to the concept of emotional labor. Although much progress has been made in the field, few studies have provided an integrated picture of how individual dispositions, perceived display rules, and emotional labor behaviors shape employee outcomes. To clarify and compare results across this growing body of literature, a quantitative review was developed, along with a theoretically derived path diagram of key emotional labor constructs. Evidence from our structural meta-analytic model based on 116 primary studies demonstrates that examining affective dispositions and emotional labor constructs and the pattern of positive and negative results helps to clarify and add specificity to the literature. Results were consistent with the perspective that surface acting emotion regulation strategies have a pattern of negative relationships with work outcomes of job satisfaction and stress/exhaustion (but not with job performance), whereas deep acting emotion regulation strategies have a pattern of positive relationships with all of these work outcomes.
Some problems in topological graph theory

A list of 31 problems presented here reflects some of the main trends in topological graph theory.
Distinct roles for Hedgehog and canonical Wnt signaling in specification, differentiation and maintenance of osteoblast progenitors

Hedgehog and canonical Wnt/beta-catenin signaling are implicated in development of the osteoblast, the bone matrix-secreting cell of the vertebrate skeleton. We have used genetic approaches to dissect the roles of these pathways in specification of the osteoblast lineage. Previous studies indicate that Ihh signaling in the long bones is essential for initial specification of an osteoblast progenitor to a Runx2+ osteoblast precursor. We show here that this is a transient requirement, as removal of Hh responsiveness in later Runx2+, Osx1+ osteoblast precursors does not disrupt the formation of mature osteoblasts. By contrast, the removal of canonical Wnt signaling by conditional removal of the beta-catenin gene in early osteoblast progenitors or in Runx2+, Osx1+ osteoblast precursors results in a similar phenotype: osteoblasts fail to progress to a terminal osteocalcin+ fate and instead convert to a chondrocyte fate. By contrast, stabilization of beta-catenin signaling in Runx2+, Osx1+ osteoblast precursors leads to the premature differentiation of bone matrix secreting osteoblasts. These data demonstrate that commitment within the osteoblast lineage requires sequential, stage-specific, Ihh and canonical Wnt/beta-catenin signaling to promote osteogenic, and block chondrogenic, programs of cell fate specification.
Interoutput times in processor sharing queues with feedback

While properties of the flows in isolated processor sharing queues are well understood, little is known about the flows in networks with processor sharing nodes. This paper analyzes the internal traffic processes in processor sharing queues with instantaneous Bernoulli feedback. The internal traffic does not inherit the insensitivity to the shape of the service requirement distribution from the external traffic. The interoutput time distribution is studied in the single server and infinite server processor sharing queues. For the systems we study, we show that when service requirement distributions with the same means are convexly ordered, so are interoutput time distributions.
Poststroke subgranular and rostral subventricular zone proliferation in a mouse model of neonatal stroke

Stroke in the neonatal brain is an understudied cause of neurologic morbidity. Recently we have characterized a new immature mouse model of stroke utilizing unilateral carotid ligation alone to produce infarcts and acute seizures in postnatal day 12 (P12) CD-1 mice. In this study, the amount of poststroke neural progenitor proliferation was examined in the subgranular (SGZ) of the dentate gyrus and the subventricular zone (SVZ) 7, 14, and 21days after ischemia (DAI). A single IP injection (50 mg/kg) of bromodeoxyuridine (BrdU) given 2 hr before perfusion fixation labeled newborn cells. Early cell phenotypes were quantified by colabeling with GFAP, nestin, and DCX. Control mice revealed an age-dependent decrease in neural proliferation, with an approximately 50% drop in BrdU-labeled cell counts at P33 compared with P19 both in the SGZ and in the SVZ. Significant reduction in the amount of neural proliferation in the ipsilateral injured SGZ of ligated mice correlated with both the severity of the stroke-injury and the acute seizure scores. Similar correlations were not detected contralaterally. Contralateral SGZ neural proliferation was initially lowered at 7 DAI but normalized by 21 DAI. In both injured and control brains, approximately 90% of newborn SGZ cells colabeled with nestin, approximately 30% colabeled with GFAP, and a few colabeled with DCX. In contrast, poststroke SVZ cell proliferation was enhanced ipsi- more than contralaterally at 7 DAI. In the SVZ, the enhanced neural proliferation normalized to control levels by P33. In conclusion, the neural cell proliferation was differentially altered in the SGZ vs. SVZ after neonatal stroke.
Location of ethylene production in cotton flowers and dehiscing fruits

Over half of the ethylene produced by 1-day-old cotton flowers came from the combined stigma, style, and stamens. These tissues produced 0.0050 μl/flower·h compared to 0.0024 and 0.0010 μl/flower·h produced by the petals and ovary, respectively. Walls of dehiscing cotton fruits produced 0.052 μl ethylene/fruit·h. This was approximately 50% more than seeds plus fiber which produced 0.033 μl/fruit·h.
How to Get Parents Involved in Your Program

Here are sixteen helpful ways to get apathetic, burned-out, intimidated, and resigned parents working with you in your special education program.
Stratification, stimuli-responsiveness, self-healing, and signaling in polymer networks

Abstract The design, development, and manufacturing of new materials continue to be an ongoing challenge for scientists and engineers. Because of similarities to biological systems having self-repairable properties, polymer networks are of particular importance and interest, and if designed properly, may provide an unprecedented opportunity for mimicking biological systems. This can be accomplished through the formation of nanostructured stimuli-responsive networks that individually or collectively respond to internal or external stimuli. This article outlines selected recent developments and future trends that will formulate foundation for the development of stratified heterogeneous stimuli-responsive polymer networks capable of reorganizing, self-healing, or signaling. The primary focus is on the physico-chemical attributes of multi-component polymer networks with localized glass transition temperatures capable of stratification and exhibiting stimuli-responsiveness or recognition attributes.
CNS tissue levels of dynorphin-A immunoreactivity and the anorexia associated with sodium chloride imbibition in the rat

Abstract Forced imbibition of increasing concentrations of sodium chloride (NaCl) in rats reduced daytime 2-deoxy-D-glucose (2-DG) induced feeding in a concentration dependent manner. Pituitary neurointermediate lobe (NIL) levels of immunoreactive (ir)-dynorphin-A 1–17 and 1–8 were also decreased by the NaCl regimen in a concentration dependent manner. However, there was no significant association between the reduction of NIL dynorphin levels and the suppression of 2-DG induced feeding on a within-animal basis. NaCl imbibition did not affect levels of either ir-dynorphin-A 1–17 or 1–8 in the hypothalamus, cerebral cortex, hippocampus, medulla/pons or anterior pituitary. Neither the acute changes following 2-DG administration, nor the comparison of ir-dynorphin-A 1–8/1–17 ratios appeared useful for the assessment of dynorphin-A turnover. Thus, the present results did not support the hypothesis that anorexia of NaCl treated animals results from the depletion of dynorphin-A.
Measurement considerations for future high speed computer packaging

AbstractThe decrease in the cycle times of computers has resulted from improvements in the performance of the active circuits and thepassive structures on which these circuits are packaged. In this paper we first summarize the state of the art in high -performancecomputer packaging. Estimates of future requirements for package interconnection structures are then described along with a fewmeasurement techniques that can be used to characterize their electrical properties. High -speed measurements on an experimentalthin -film transmission line structure obtained using three of these techniques are presented to illustrate the different measurementconsiderations.IntroductionAs a result of the dramatic improvements in circuit speed and density provided by new integrated circuit (IC) technologies,package characteristics have become a major factor in determining computer system performance. With the projected enhance-ments in device and circuit speeds of advanced silicon ICs, continued decrease in the cycle time of digital computers will becomemore dependent on the performance of the structures on which these circuits are packaged. Packaging limitations are expectedto be even more severe for the higher speed GaAs device technologies.For a typical mainframe computer system, a large fraction of the cycle time is already due to the propagation delays introducedby wires interconnecting the semiconductor ICs which make up its logic and memory [1]. The package also contributes to variousundesirable phenomena such as pulse dispersion, reflections, crosstalk and switching induced noise, all of which limit the systemperformance which can be attained. Higher switching speeds place greater demands on the bandwidth of the package, and requirethat accurate models of package wiring characteristics be developed to aid in engineering an optimum design. High speed meas-urement techniques are required to adequately characterize such designs, and to refine the analytical models which are used topredict their behavior.In this paper, we concentrate on the problems of chip to chip interconnection wiring, and the various high speed measurementtechniques which are useful in characterizing its performance. We first briefly summarize the state of the art in high performancecomputer packaging, and present estimates of future trends in chip and package characteristics. We then survey the various highspeed measurement techniques which may be useful for characterizing the electrical properties of packaging structures. Finally,results obtained from the use of several high speed measurement techniques on an experimental thin film transmission line struc-ture are described.
Effects of Oocyte Maturation Length, Sperm Capacitation Time, and Heparin on Bovine Embryo Development

Abstract This study examined the effects of extending oocyte maturation 4h beyond current methods and capacitating sperm with or without heparin 4h before oocyte introduction to determine whether embryo development would increase after in vitro fertilization. Oocytes were aspirated from ovaries that were collected at slaughter. Cumulus-enclosed oocytes were matured in M-199 supplemented with serum from cows in standing estrus (20%), antibiotic-antimycotic solution (1%), HEPES (10m M ), and equine LH (30 μ g/ml) in a humidified 5% CO 2 atmosphere. Oocytes were matured for either 24 or 28h and subsequently fertilized with sperm that had been capacitated 0 or 4h (before oocyte contact) with or without heparin (0.2 μ g/ml). Data were analyzed as a 2 × 2 × 2 factorial design. Percentages of cleavage and development were transformed by the arcsin square root method before analysis of variance. An interaction of maturation length and sperm capacitation resulted because cleavage rate decreased with precapacitated sperm, but only within the 24-h maturation period. Heparin increased cleavage rate at 48h after fertilization but did not affect further development. More oocytes developed to morulae when they matured for 24h than when they matured for 28h. In conclusion, a 24-h maturation length without precapacitated sperm was optimal for the subsequent development of cumulus-oocyte complexes.
Flexible time-windows for advance reservation in LambdaGrids

Advance-reservation requests are an essential feature of LambdaGrids, where resources may need to be co-allocated at pre-determined times. In this paper, we discuss unconstrained advance reservations, which use flexible time-windows to lower blocking probability and, consequently, increase resource utilization. We claim and show using simulations that the minimum window size, which theoretically brings the blocking probability to 0, in a first-come-first-served advance reservation model without time-slots, equals the waiting time in a queue-based on-demand model. We also show, with simulations, the window sizes, which bring the blocking probability to its minimum, for an advance reservation model with time-slots.
Database accuracy: results from a survey of database vendors

Abstract The accuracy of databases is the subject of our survey of vendors of databases. This study examines external databases. Among the issues covered by the survey are: selection criteria for data sources, formats of data, and the approaches followed in maintaining database accuracy. One specific focus of the study is external databases for forecasting. Forecasting, as a tool of managerial planning, is sensitive to the availability and accuracy of databases. The survey results suggest that there are some practices followed by database suppliers that could produce unreliable information.
Thiol-dependent passive K+Cl- transport in sheep red blood cells: VI. Functional heterogeneity and immunologic identity with volume-stimulated K+(Rb+) fluxes.

Ouabain-resistant (OR), volume-or N-ethylmaleimide (NEM)-stimulated K+(Rb+)Cl− fluxes were measured in low-K+ sheep red cells and found to be functionally separate but immunologically similar. In anisosmotic solutions both K+ effluxes and Rb+ influxes of NEM-treated and control cells were additive. In contrast to the NEM-stimulated K+Cl− flux, metabolic depletion did not reduce K+Cl− flux of normal or swollen cells. The anion preference of OR K+ efflux in NEM-treated cells was Br−>Cl−>HCO3−=F−≫I−=NO3−=CNS−, and hence consistent with a reported Br−>Cl−>NO3− sequence of the volume-dependent K+Cl− transport. Alloimmune anti-Ll antibodies known to decrease passive K+ fluxes in low K+ cells reduced by 51% both volume-and NEM-stimulated, furosemidesensitive Rb+Cl− fluxes suggesting their immunologic identity, a conclusion also supported by anti-L1 absorption studies. Since pretreatment with anti-L1 prevented the activation of Rb+ influx by NEM, and the impermeant glutathionmaleimide-I did not stimulate Rb+Cl− influx, the NEM reactive SH groups must be located apart from the L1 antigen either within the membrane or on its cytoplasmic face. A model is proposed consisting of a K+Cl− transport path(s) regulated by a protein with two functional subunits or domains; a chemically (Cs) and a volume (Vs)-stimulated domain, both interfacing with the L1 surface antigen. Attachment of alloanti-L1 from the outside reduces K+Cl− transport stimulated throughCs by NEM orVs by cell swelling.
Transport of vitamin E by differentiated Caco-2 cells

In hepatocytes, vitamin E is secreted via the efflux pathway and is believed to associate with apolipoprotein B (apoB)-lipoproteins extracellularly. The molecular mechanisms involved in the uptake, intracellular trafficking, and secretion of dietary vitamin E by the intestinal cells are unknown. We observed that low concentrations of Tween-40 were better for the solubilization and delivery of vitamin E to differentiated Caco-2 cells, whereas high concentrations of Tween-40 and sera inhibited this uptake. Vitamin E uptake was initially rapid and then reached saturation. Subcellular localization revealed that vitamin E primarily accumulated in microsomal membranes. Oleic acid (OA) treatment, which induces chylomicron assembly and secretion, decreased microsomal membrane-bound vitamin E in a time-dependent manner. To study secretion, differentiated Caco-2 cells were pulse-labeled with vitamin E and chased in the presence and absence of OA. In the absence of OA, vitamin E was associated with intestinal high density lipoprotein (I-HDL), whereas OA-treated cells secreted vitamin E with I-HDL and chylomicrons. No extracellular transfer of vitamin E between these lipoproteins was observed. Glyburide, an antagonist of ABCA1, partially inhibited its secretion with I-HDL, whereas plasma HDL increased vitamin E efflux. An antagonist of microsomal triglyceride transfer protein, brefeldin A, and monensin specifically inhibited vitamin E secretion with chylomicrons. These studies indicate that vitamin E taken up by Caco-2 cells is stored in the microsomal membranes and secreted with chylomicrons and I-HDL. Transport via I-HDL might contribute to vitamin E absorption in patients with abetalipoproteinemia receiving large oral doses of the vitamin.
Classical molecular electrostatics: recognition of ligands in proteins and the vibrational Stark effect.

It is shown that classical electrostatics quantitatively describes both the binding of the diatomic ligands XO (X = C, N, O) to the heme group in myoglobin and the dependence of their vibrational frequencies upon an external field, the vibrational Stark effect. The key is a proper treatment of induced dipoles. The results suggest that ligand binding occurs via an “electrostatic bond”, a generalization of the standard ionic bond to include induction, and, more generally, that classical electrostatics can replace quantum mechanics for a considerable simplification of some complex problems.
The action of oxygen and oxygen at high pressure on inhibitory transmission.

Abstract The effect of 100% oxygen at ambient pressure, 100% oxygen at 1.7 Atmospheres Absolute (ATA), 100% oxygen at 5.1 ATA, helium at 1.7 ATA and helium at 5.1 ATA on inhibitory synaptic transmission was studied using the lobster walking leg neuromuscular preparation. Exposure to 100% oxygen at ambient pressure, at 1.7 ATA or at 5.1 ATA produced a decrease in inhibitoru transmission manifest as a fall in inhibitory synaptic conductance (Ginh). The largest decrease in Ginh was seen in 100% oxygen at ambient pressure. while a progressively smaller decrease was seen in 100% oxygen at 1.7 ATA and 5.1 ATA, respectively. Also associated with 100% oxygen at ambient pressure was the disappearance of inhibitory junction potentials. Pressurization with helium produced a fall in Ginh at 5.1 ATA but no change or a slight increase at 1.7 ATA. The action of either 100% oxygen at ambient and at 1.7 or 5.1 ATA or helium at 1.7 or 5.1 ATA was shown to be on presynaptic parameters since the percent decrease in Ro induced by oxogenous application of gamma-aminobutyric acid (GABA), the inhibitory transmitter, was the same in either 100% oxygen at ambient pressure, 100% oxygen or helium at 1.7 ATA and 5.1 ATA. The similarity in action of oxygen to the action of isoniazid, a known glutamic acid decar☐ylase (the enzyme that catalyzes the production of GABA) inhibitor in the same preparation suggests that one possible site of oxygen action is on GABA production.
Common genetic variation, residential proximity to traffic exposure, and left ventricular mass: The multi-ethnic study of atherosclerosis

BackgroundElevated left ventricular mass (LVM) is a strong predictor of negative cardiovascular outcomes, including heart failure, stroke, and sudden cardiac death. A relationship between close (< ...
The hydrolysis of halocarbon refrigerants in freeze desalination processes Part 1. Solubility and hydrolysis rates of Freon 114 (CClF2CClF2)

Abstract The solubility and rate of hydrolysis of Freon 114 (CClF 2 CCLF 2 ) have been measured over a range of conditions relating to secondary refrigerant freeze desalination technology. In this paper, results are presented for the solubility of gaseous Freon 114 between 0 and 50°C as a function of pressure in pure and saline water. The solubility of liquid Freon 114 has been calculated from vapor pressure data and Henry's law extrapolations. The magnitude of the calculated heat of solution is consistent with corresponding results for other fluorocarbon refrigerants. Semiempirical relations are also presented for solubility trends of fluorocarbon refrigerants as a function of molecular parameters of molar volume and polarizability. The very slow rates of hydrolysis of Freon 114 with and without catalysts have been followed with an ion selective membrane electrode which responds to fluoride ion activity. The significance of the results to the economics of refrigerant loss in freeze desalination plants is discussed. On the basis of the measured hydrolysis rates and estimated residence times based on feed flow for a typical plant, it is concluded that economic losses resulting from hydrolysis of Freon 114 would amount to less than 0.001¢ (U.S.) per 1000 gallons.
Narrative-Based Collaboration Systems for Distributed Teams: Nine Research Questions for Information Managers

We propose a framework to explore how narrative can support distributed teams. Although information technologies enable distributed teamwork, they may increase the level of abstraction forced upon teams by the absence of co-location. To counter these effects, we explore how elements of narrative may be useful through their ability to convey team-related information. Nine research questions are presented that examine ways in which we can explore narrative information systems as tools for studying distributed teamwork.
Electron irradiation of poly(3-hexylthiophene) films

The effects of low-energy electron irradiation on spin-coated films of regioregular poly(3-hexylthiophene) have been studied with fluorescence, mass spectrometry, and a variety of electron spectroscopies, including photoemission. Electron impact by 180 eV electrons causes a decrease in photoluminescence intensity, broadening of the thiophene ring valence electronic state features, and diminution in intensity of the peaks due to π electrons delocalized along the backbone. Electron bombardment also results in a decrease in the X-ray photoelectron spectroscopy sulfur-to-carbon ratio, but only minor shifts in the binding energies of the C 1s and S 2p peaks occur. Quadrupole mass spectrometry has been used to detect electron-stimulated desorption from the polymer films. Ionic desorption includes S-, SH-, S+, and CxHy+ species. Auger electron spectroscopy confirms removal of sulfur from the near-surface region by a 5 keV electron dose of 1.8 × 1018 electrons/cm2, and electron energy loss spectroscopy suggests f...
Structural and functional insights into sulfated galactans: a systematic review

Sulfated galactans (SGs) are highly anionic marine galactose-composed homopolysaccharides. Although their structures vary among species, their main features are conserved among phyla. Green algal SGs are quite heterogeneous, although preponderantly composed of 3-β-D-Galp units. The red algal SGs (like agar and carrageen) are composed of repeating disaccharide units with different sulfation patterns which vary among species. The SGs from invertebrates such as sea urchins and ascidians (tunicates), and from the unique description of a sea-grass, are composed of well-defined repetitive units. Chains of 3-linked β-galactoses are highly conserved in some marine taxonomic groups, with a strong tendency toward 4-sulfation in algae and marine angiosperm, and 2-sulfation in invertebrates. These carbohydrates are extracellular components of the cell wall in plants, of the body wall in tunicates, and of the jelly coat in sea urchin eggs. In sea urchins, the SGs are also responsible to induce the acrosome reaction. However, the wide range of potential pharmacological uses, especially as anticoagulants and antithrombotics, is the main reason for the increasing interest in these sugars. Both natural and clinical actions of SGs have a direct relation to their structural features, since the intermolecular complexes between SG and target proteins are much more stereospecific than only electric charge-dependent. This review will present an overview about the principle structural and functional information of SGs. Other important aspects concerning occurrence, biology, phylogeny, and future directions, will also be reported.
Negotiation of inquiries in an on-line retrieval system

Abstract The focus of discussion is a prototype retrieval system with three major components for textprocessing, connectivity and decision operations. Each of these components is based on a distinguishable subtheory. Computer programs for the first two components have been written for a GE 225 computer. The complete prototype system is now being programmed for operation in a time-shared environment. It is a user-oriented system, with planned capabilities for browsing and man-machine interaction. A major goal is to develop procedures whereby research workers can conduct an on-line dialogue via terminals with a body of scientific information. Each user-submitted inquiry is a set of sentences without restriction as to vocabulary or form. The system converses with the user to obtain source-derived phrases that elaborate and refine the initial inquiry. The user is led to browse in the general area of his inquiry and to broaden or narrow it as he wishes. The system presents him with the text of documents related to his request as a further aid to request formulation. Evaluation of system performance is discussed.
Molecular genetic detection of Bacteroides heparinolyticus in adult periodontitis

Bacteroides heparinolyticus in subgingival plaque was identified using a digoxigenin-labeled whole genomic DNA probe and a polymerase chain reaction (PCR) assay based on 16S rRNA species-specific primers (5'-ATG GTG ATT CCG CAT GGT TTC TCC-3' (base position, 188-212) and 5'-CAA ACT TTC ACA GCT GAC TTA AGC-3' (592-615)). Subgingival specimens obtained by paper points from 3 deep periodontal pockets in each of 113 adults were examined. The DNA probe reacted with all pure isolates tested of B. heparinolyticus and did not react with other oral species tested; the probe showed positive reactions in 74.3% of the patient samples examined. The PCR primers produced the 428 bp species specific amplification product in all B. heparinolyticus test strains and did not reveal detectable amplicons with strains of other subgingival species. The PCR method detected 50 B. heparinolyticus cells dispersed in subgingival plaque. PCR only revealed B. heparinolyticus in 6.2% of the patient samples studied. The higher level of positive specimens with the DNA probe was probably due to false-positive reactions from cross-hybridization with unknown subgingival species. This study suggests that the PCR method amplifying specific 16S rRNA sequences represents an easy and valuable means to detect B. heparinolyticus in subgingival plaque. The low prevalence of subgingival B. heparinolyticus does not incriminate the organism in the etiology of adult periodontitis.
Investigation of a shape memory alloy actuator for dextrous force-feedback masters

Multifingered dextrous robot hands can perform more complex tasks than simpler end effectors. Teleoperation, in which a robot mimics the motion of a remote operator, provides a convenient method for controlling these robot hands. Damage to the object being manipulated by the robot hand may result in the case of open-loop control if there is no force-feedback sensation to the operator from the robot hand. The need arises for new actuator technology to provide force feedback to the hand master. These actuators have to meet the tight space and light weight requirements of a dextrous master. One candidate is the shape memory alloy (SMA) actuator. SMAs, such as Nitinol, are materials with a unique 'mechanical memory' and high force/weight ratio. A prototype SMA actuator and its hardware interface were designed and tested. Results showed that the actuator met the space and weight limitations of the master (Exos DHM™) and provided adequate reactive force feedback to the operator. However, the actuator had a low ...
The integer points on three related elliptic curves

The integer points on the three elliptic curves y2 = 4cx3 + 13, c = 1, 3, 9, are found, with an application to coding theory. It is also shown that there are precisely three nonisomorphic cubic extensions of the rationals with discriminant -35 13. 1. In [I] the Diophantine equation (1) y2 = 4 . 3k + 13 is shown to arise from coding theory, and its integer solutions are found. By considering congruence classes of k modulo 3, this equation gives rise to the three elliptic curves (2) y2=4x3 + 13, (3) y2 = 12x3 + 13, (4) y2= 36x3 + 13. We find here all integral solutions of (2), (3), (4), giving as a corollary all solutions to Eq. (1). 2. Since Q( 13) has class number 1, Eq. (2) immediately reduces to an equation y+ 13 1+ 13 2 = E a+ b 2 J where a, b E Z, e (3 + 13)/2 is a fundamental unit of Q( 13), and where without loss of generality K0, + 1. Since a3 E Z[ 13 1 for every integer a E Q(133), the case K 0 is impossible. Comparing coefficients of 13 in the two cases K 1 gives respectively (5) K = 1: 1 -a3 + 6a2b + 15ab2 + Ilb3, (6) K -1: 1 a3 3a2b + 6ab2 b3. Under the respective substitutions (A, B) = (a + 2b, b), (A, B) = (a b, -b) both (5) and (6) reduce to (7) 1 =A3 + 3AB2-3B3. We now work in Q(X), where 23 + 3X 3 0 O. It is straightforward to verify that the ring of integers in this field is Z[X], and a fundamental unit is = X. (The Received May 8, 1981; revised October 13, 1981. 1980 Mathematics Subject Classificatioti. Primary IOB 10; Secondary 1 2A30. ? 1982 American Mathematical Society 0025-5718/81 /0000-0446/$0 1.75
Amyloid-like protein of human skin: neutral-salt solubilization and reconstitution.

Abstract Extraction of normal human skin with neutral 1 or 2 M NaCl solution solubilized a protein which was unsedimented at 160 000 × g . A larger amount of soluble protein was found in human newborn skin than in adult skin. Dialysis against 0.5 M acetic acid resulted in precipitation of a protein which, after purification, was free of hydroxyproline and had an amino acid composition similar to that of human amyloid.
Decoupling confinement and chiral-symmetry breaking: An explicit model.

Using a covariant model of mesons developed previously, we obtain new numerical solutions for the light-quark sector, and show explicitly how the small mass of the pion emerges as a natural consequence of chiral-symmetry breaking. Then we generalize the model, and show how chiral-symmetry breaking and confinement could be realized through completely independent mechanisms with different mass scales. In particular, the confining potential can be chosen to be purely scalar, as suggested by lattice studies and phenomenology, and the remaining part of the interaction can be chosen to be chirally invariant. In a symmetry-breaking mode, this new model can still generate quark mass and a massless-pion bound state.
Predation at a snail's pace: what's time to a gastropod?

Predation by naticid gastropods shows evidence of adaptation to maximize the rate of energy intake. The predation rate of Polinices duplicatus feeding on artificially altered, thin-shelled Mercenaria mercenaria was faster than the predation rate on normal Mercenaria. The rate of energy intake was limited by handling time. The time saved by predation on thin-shelled prey was used to forage. Thus time was shown to be valuable to P. duplicatus, and cost-benefit functions using time and energy as currencies are appropriate for estimating dietary efficiency and predicting prey choice.
Cocaine and Specific Cocaine Metabolites Induce von Willebrand Factor Release From Endothelial Cells in a Tissue-Specific Manner

Objective—Cocaine use is associated with arterial thrombosis, including myocardial infarction and stroke. Cocaine use results in increased plasma von Willebrand factor (VWF), accelerated atherosclerosis, and platelet-rich arterial thrombi, suggesting that cocaine activates the endothelium, promoting platelet–VWF interactions. Approach and Results—Human umbilical vein endothelial cells, brain microvasculature endothelial cells, or coronary artery endothelial cells were treated with cocaine or metabolites benzoylecgonine, cocaethylene, norcocaine, or ecgonine methylester. Supernatant VWF concentration and multimer structure were measured, and platelet–VWF strings formed on the endothelial surface under flow were quantified. Cocaine, benzoylecgonine, and cocaethylene induced endothelial VWF release, with the 2 metabolites being more potent than the parent molecule. Brain microvasculature endothelial cells were more sensitive to cocaine and metabolites than were human umbilical vein endothelial cells or coron...
The long and short of adaptor appendages

Two new structural studies reveal the nature of accessory protein binding to trans-Golgi network–specific adaptors of clathrin-coated vesicles.
Herbal medicines today and the roots of modern pharmacology.

The transformation of digitalis from a folk medicine, foxglove, to a modern drug, digoxin, illustrates principles of modern pharmacology that have helped make drugs safer and more effective. Digitalis was improved because its preparation was standardized, first by bioassay and then by chemical methods; however, few of today's herbs are standardized by methods that can ensure a consistent product and, hence, consistent safety and efficacy profiles. Many herbs have been evaluated in randomized, controlled trials, and several-St. John's wort and ginkgo, for example-are apparently effective. Yet, many trials of herbs have limited value because of poor design, small samples, and, above all, use of products of uncertain composition and consistency. The uncertain composition of many herbal products raises questions about their safety, as does evidence indicating that herbs may have harmful interactions with prescription drugs. Such adverse effects of herbs are probably underreported. Meanwhile, systematic studies, such as those identifying adverse reactions to drugs, are hindered because herbal preparations are not standardized-one brand of St. John's wort, for example, will differ chemically from another-and, unlike for prescription drugs, there are no databases linking herb consumption to later medical problems. Since herbal medicines are regulated as dietary supplements, they are not subject to the premarketing regulatory clearance required for drugs. The burden of proof is on the U.S. Food and Drug Administration to show a dietary supplement is unsafe, unlike for drugs, which cannot be approved until the manufacturer has demonstrated safety and effectiveness.
Mobile strands are frequently attached to the St. Jude Medical mitral valve prosthesis as assessed by two-dimensional transesophageal echocardiography.

Abstract Two-dimensional transesophageal echocardiographic findings are reported in 13 patients with structurally and functionally normal St. Jude Medical bileaflet mitral valve prostheses. Multiple mobile linear echogenic densities attached to the pivot of the prosthesis were present in 9 of 13 pateints. These densities may represent fibrin strands. These mobile strands alternatively resolve and reform over a period of 5 to 14 months after mitral valve replacement. No adverse clinical events were attributable to these prosthetic mitral valve strands. We conclude that mobile stands are frequently attached to the structurally and functionally normal St. Jude Medical mitral valve prosthesis. The clinical significance of these prosthetic mitral valve strands requires clarification.
Neoadjuvant radiochemotherapy for locally advanced gastric cancer: Long-term results of a phase I trial

Purpose: To assess the long-term results of radiation therapy (RT) when added preoperatively to systemic chemotherapy in patients with locally advanced gastric cancer. Methods and Materials: Patients presenting with T3–4 or N+ gastric cancer received two cycles of cisplatin 100 mg/m 2 d1, 5FU 800 mg/m 2 d1–4, and Leucovorin 60 mg twice daily d1–4; one cycle before and one concomitantly with hyperfractionated RT (median dose, 38.4; range, 31.2–45.6 Gy). All patients underwent a total or subtotal gastrectomy with D2 lymph node resection. Results: Nineteen patients were accrued and 18 completed the neoadjuvant therapeutic program. All patients were subsequently operated and no fatality occurred. At a mean follow-up of 8 years for the surviving patients, no severe late toxicity was observed. The 5-year locoregional control, disease-free, and overall survival were of 85%, 41%, and 35%, respectively. The peritoneum was the most frequent site of relapse. Among long terms survivors, no severe (Radiation Therapy Oncology Group Grade 3–4) late complication was reported. Conclusions: The present neoadjuvant treatment does not seem to increase the operative risk, nor the late side effects. The encouraging locoregional control rate suggests that the neoadjuvant approach should be considered for future trials in locally advanced gastric cancer. Also, the frequency of peritoneal recurrence stresses the need for a more efficient systemic or intraperitoneal treatment.
Polarimetric thermal emission from rough ocean surfaces

A numerical study of the polarimetric thermal emission from ocean surfaces randomly rough in one dimension using a Monte Carlo technique is presented. In this study, a set of finite length surface profiles with desired statistics was generated using a spectral method. Each surface was extended periodically to create an infinite rough surface, and the thermal emission was computed using the extended boundary condition method (EBC) and the method of moments (MOM). The results from the set of surfaces were then averaged to obtain the Monte Carlo estimate of polarimetric thermal emission. The surface statistics chosen were intended to model a wind perturbed ocean surface in the X to Ku band microwave region. The results of the study show that the third Stokes parameter, UB , is sensitive to the azimuthal angle between the surface periodicity and the looking angle, the rms height of the surface, and the surface power law spectrum slope, and that this parameter is insensitive to variations in polar angle, permi...