cssi/SciSciGPT-SciSciNet huggingface dataset:
Holocene evolution of the western Greenland Ice Sheet: Assessing geophysical ice-sheet models with geological reconstructions of ice-margin change

Abstract Geophysical ice-sheet models are used to predict future ice-sheet dimensions and, in turn, these projections help estimate the magnitude of eustatic sea-level rise. Before models can confidently predict ice-sheet behavior, they must be validated by being able to duplicate the geological record of ice-sheet change. Here, we review geological records of Greenland Ice Sheet (GrIS) change, with emphasis on the warmer-than-present middle Holocene, and compare these records to published studies that numerically simulate GrIS behavior through the Holocene. Geological records are concentrated in West and Southwest Greenland, which are also the regions where the GrIS margin likely experienced the greatest distance of inland retreat during the middle Holocene. Several records spanning from Melville Bugt to Jakobshavn Isfjord in western Greenland indicate the GrIS achieved its minimum extent between ∼5 and 3 ka, and farther south in the Kangerlussuaq region, new data presented here indicate the ice margin reached its minimum extent between ∼4.2 and 1.8 ka. In the Narsarsuaq region in southern Greenland, the GrIS likely achieved its minimum configuration between ∼7 and 4 ka. We highlight key similarities and discrepancies between these reconstructions and model results, and finally, we suggest that despite some degree of inland retreat, the West and Southwest GrIS margin remained relatively stable and close to its current position through the Holocene thermal maximum.
Working with families of suddenly and critically ill children: physician experiences.

Objective To describe physicians' experiences in attempting to provide optimal care for families of children who suffer from sudden, acute life-threatening conditions (SALTC). Design To generate descriptive data in this exploratory study, we used qualitative methods including focus groups and in-depth interviews. Transcripts of focus groups and interviews were analyzed for content using standard phenomenologic analysis methods, which resulted in a participant-generated conceptual model of optimal care for families of children with SALTC. Setting The intensive care unit of an urban pediatric teaching hospital. Participants Twenty-two pediatric intensive care unit physicians, including residents, fellows, and attendings. Intervention None. Main Outcome Measures Each participating physician provided qualitative descriptions of experiences caring for families of children with SALTC. Results Physicians identified 4 components of optimal care for families: (1) providing timely, accurate information about their child; (2) maintaining privacy for confidential discussions and personal grieving; (3) giving adequate emotional support; and (4) granting family members the right to hold and comfort their dying child. Physicians also described barriers to, and facilitators of this optimal care. Conclusions Descriptive information provided in this exploratory study offers a complex model of optimal family care. Issues that affect the quality of care to families include those related to the context of providing care in a large teaching hospital, as well as subtleties of communication between parents and staff. Physicians' beliefs about optimal care of families in the pediatric intensive care unit revealed implications for both practice and training in pediatrics.
When to bundle or unbundle products

Abstract Product bundling is used in almost every industry, but frequently it is not part of a specific and intentional strategy. Unfortunately, failing to consider bundling as a strategic marketing variable may unnecessarily reduce the performance of the firm. This paper discusses the numerous and diverse factors that influence the effectiveness of a bundling strategy and provides work sheets for managers to use for measuring and analyzing the feasibility of a bundling or an unbundling strategy.
Polymer-bound photobase generators and photoacid generators for pitch division lithography

The semiconductor industry is pursuing several process options that provide pathways to printing images smaller than the theoretical resolution limit of 193 nm projection scanners. These processes include double patterning, side wall deposition and pitch division. Pitch doubling lithography (PDL), the achievement of pitch division by addition of a photobase generator (PBG) to typical 193 nm resist formulations was recently presented.1 Controlling the net acid concentration as a function of dose by incorporating both a photoacid generator (PAG) and a PBG in the resist formulation imparts a resist dissolution rate response modulation at twice the frequency of the aerial image. Simulation and patterning of 45 nm half pitch L/S patterns produced using a 90 nm half pitch mask were reported.2 Pitch division was achieved, but the line edge roughness of the resulting images did not meet the current standard. To reduce line edge roughness, polymer bound PBGs and polymer bound PAGs were investigated in the PDL resist formulations. The synthesis, purification, analysis, and functional performance of various polymers containing PBG or PAG monomers are described herein. Both polymer bound PBG with monomeric PAG and polymer bound PAG with monomeric PBG showed a PDL response. The performance of the polymer bound formulations is compared to the same formulations with small molecule analogs of PAG and PBG.
Magnetohydrodynamic Flow Past a Thin Airfoil

Abstract : The steady flow of a perfectly conducting magnetohydrodynamic fluid past a thin non-conducting airfoil is studied in the model in which the fluid variables obey the Lundquist equations linearized about a constant unperturbed flow. Hyperliptic flows, in which hyperbolic and elliptic fields are superimposed, are considered. Results of Grad, McCune and Resler, and Sears and Resler are extended to the case of an arbitrarily inclined unperturbed field. The general solution contains four line singularities along the characteristics through the ends of the body, and has two arbitrary constants. By a generalized Kut a-Joukowski condition these constants are fixed so that two of the line singularities disappear. Specifically, it is required that the solution be locally square integrable. Behavior of the exponents of the singularities is investigated by numerical computation and, in limiting cases, analytically. The singular parts of some flows are investigated numerically. (Author)
Enzymes and industry: A tasty compendium

Industrial Enzymology, Second Edition, Tony Godfrey and Stuart West (eds.). Macmillan Press, Basingstoke, UK, 1996, pp. 609, £110.00, (hbk).
Epidermal growth factor-induced cell proliferation in the adult rat striatum

Abstract Current strategies for repairing the adult CNS following injury include cell transplantation and/or the use of viral vectors to deliver therapeutic agents. Although promising, both techniques are limited in their usefulness due to the immunological response triggered in the brain as a result of the introduction of foreign antigens. An alternative method to repair the damaged CNS is to stimulate endogenous cells within the brain to divide thereby replacing cells lost to injury. Since it has been shown that growth factors such as epidermal growth factor (EGF) are potent mitogens to CNS cells in vitro, we sought to assess the mitogenic effect of an in vivo application of EGF to the adult mammalian brain. Accordingly, varying doses of human recombinant EGF were administered to the striatum of adult rats, followed 48 h later by intraperitoneal injections of 5-bromodeoxyuridine (BrdU), a marker for cell proliferation. Of four doses assessed, 0.05 ng of EGF induced the highest levels of cell proliferation. To determine the cellular identity of these proliferating cells, animals were injected with 3H-thymidine 48 h following EGF administration to label dividing cells. Sections were subsequently immunostained for markers to astrocytes, microglia, oligodendrocytes, neural precursors, and mature neurons. Compared to controls, a significant proportion of the newly generated cells resulting from EGF administration were identified as immature and mature astrocytes. Collectively, these results provide valuable information for utilizing a growth factor administration approach to mobilize the proliferative response of endogenous cells to replace those lost to injury or disease.
Long-range polony haplotyping of individual human chromosome molecules

We report a method for multilocus long-range haplotyping on human chromosome molecules in vitro based on the DNA polymerase colony (polony) technology. By immobilizing thousands of intact chromosome molecules within a polyacrylamide gel on a microscope slide and performing multiple amplifications from single molecules, we determined long-range haplotypes spanning a 153-Mb region of human chromosome 7 and found evidence of rare mitotic recombination events in human lymphocytes. Furthermore, the parallel nature of DNA polony technology allows efficient haplotyping on pooled DNAs from a population on one slide, with a throughput three orders of magnitudes higher than current molecular haplotyping methods. Linkage disequilibrium statistics established by our pooled DNA haplotyping method are more accurate than statistically inferred haplotypes. This haplotyping method is well suited for candidate gene-based association studies as well as for investigating the pattern of recombination in mammalian cells.
Inflammatory mediators induced by intratracheal instillation of ultrafine amorphous silica particles

Abstract In order to evaluate the pulmonary effects and inflammatory mechanisms of ultrafine amorphous silica particles (UFASs), the UFASs suspension was prepared in PBS and intratracheally administered to A/J mice at doses of 0, 2, 10 and 50 mg/kg ( n = 5 per group). Animals were sacrificed at 24 h, and 1, 4 or 14 weeks following exposures. At each time point, a bronchoalveolar lavage fluid analysis, histopathological examination, quantitative real-time PCR and immunohistochemistry of the lung tissues were assessed. The intratracheal instillation of UFASs significantly increased the lung weights and total BAL cells following exposures. The histopathological examination revealed that UFASs-induced severe inflammation, with neutrophils, at an early stage and chronic granulomatous inflammation at the later stage. The mRNA and protein levels of IL-1β, IL-6, IL-8, TNF-α, MCP-1 and MIP-2 in lung tissues were significantly increased during the early stages, but there were no changes after weeks 1 (TNF-α) or 4 (IL-1β, IL-6, IL-8, MCP-1 and MIP-2). Instillation of UFASs-induced transient, but very severe lung inflammation. Therefore, the cytokines (IL-1β, IL-6, IL-8 and TNF-α) and chemokines (MCP-1 and MIP-2) play important roles in the inflammation induced by the intratracheal instillation of UFASs.
Synthesis and acidity constants of 13CO2H-labelled dicarboxylic acids. pKas from 13C-NMR

Abstract Simple dicarboxylic acids: adipic ( 1 ), succinic ( 2 ) and malonic ( 3 ); more complex linear tetrapyrroles with two propionic acid groups: mesobiliverdin-XIIIα ( 4 ) and mesobilirubin-XIIIα ( 5 ), and a rubin analog with a gem -dimethyl at C 10 ( 6 ) were prepared with 99% 13 C-enrichment in their CO 2 H groups. Their p K a values were determined from titration curves in water and in H 2 O-(CD 3 ) 2 SO solutions: plots of carboxyl carbon 13 C-NMR chemical shifts with varying p H. Titration curves of diacids 1–3 with known p K a 's in H 2 O served as calibration standards for determination of p K a s of tetrapyrrole diacids 4–6 : p K a1 = 3.9, p K a2 = 5.3 for 4 ; p K a1 = 4.2, p K a2 = 4.9 for 5 , and p K a1 = 4.7, p K a2 = 5.7 for 6 in H 2 O.
Logistical supply chain design for bioeconomy applications

Abstract This paper proposes and tests novel supply chain designs for bioenergy and biobased products that result in logistical costs savings of 2–38%. The proposed supply chain design reduces the costs of: (1) purchasing logistical harvesting equipment; (2) operating logistical harvesting equipment; and (3) holding feedstock inventory, by using a multitude of crop types as feedstock, instead of just one, as is common in research and practice today. In so doing, this research challenges the prevalent assumption that monocultures, despite their known environmental concerns, are preferable from a costs perspective. Simulation/optimization is used to test supply chain designs, and then to find the environmental conditions where these new supply chain designs could be most profitably implemented.
A series magnetic amplifier with inductive loading

The circuit examined is the series-connected magnetic amplifier of Figure 1. This circuit has been the subject of many analyses; however, in almost all instances simplifying assumptions were made concerning the magnitude of some of the circuit parameters, but very little work has been done on circuits in which L a and L d were not zero. This article analyzes and discusses the changes in current waveshape produced by variation of the circuit parameters E d , R a , L d , R a , and La a .
Applications of nanotechnology within high-performance sealing materials

The fillers used in an elastomer compound can directly affect both the physical properties and chemical resistance. This article reviews the types of fillers that may be used, how they affect the material performance, and shows why the use of certain nanoparticle fillers can improve material properties. An example of a successful application to perfluoroelastomers for aggressive chemical applications is discussed.
Nuclear-magnetic-resonance study of the cubic alkali tungsten bronzes

NMR measurements of the cubic alkali tungsten bronzes ${\mathrm{Na}}_{x}\mathrm{W}{\mathrm{O}}_{3}$ ($0.22\ensuremath{\lesssim}x\ensuremath{\lesssim}0.84$) and ${\mathrm{Li}}_{x}\mathrm{W}{\mathrm{O}}_{3}$ ($0.27\ensuremath{\lesssim}x\ensuremath{\lesssim}0.49$) are presented. Knight shifts, relaxation times, and line shapes of $^{183}\mathrm{W}$ were studied over the temperature range 1.35-4.2 K. ${T}_{1}$ and $K$ of $^{7}\mathrm{Li}$ at 77 and 298 K were also measured. These results coupled with previous $^{23}\mathrm{Na}$ measurements are correlated to possible conduction-band models. The results for $xg0.40$ are consistent with a $\mathrm{W}5d({t}_{2g})$ conduction band analogous to the Re $5d({t}_{2g})$ band in Re ${\mathrm{O}}_{3}$ band-structure calculations. For $xl0.40$ the data suggest admixture of Na and W $6s$ states in the ${\mathrm{Na}}_{x}\mathrm{W}{\mathrm{O}}_{3}$ conduction band. Regarding the metal-semiconductor transition occurring in the bronzes, the NMR results seem incompatible with simple nearest-neighbor linkage and correlated site percolation models of conduction for the bronzes. The results give no evidence of a Mott-type transition occurring as no correlation effects are observable.
Direct/delayed response project: Predicting future long-term effects of acidic deposition on surface water chemistry

In 1984 the U.S. Environmental Protection Agency, as part of the National Acid Precipitation Assessment Program, initiated a project to estimate potential future effects of acidic deposition on the chemistry of lakes and streams. This project, the Direct/Delayed Response Project (DDRP), has focused its attention on surface waters in regions of the eastern U.S. thought to be most vulnerable to effects of acidic deposition. The project hascombined regional surface water chemistrydata gathered by EPA's National Surface Water Survey with a unique regional watershed and soil survey under take n within the DDRP.The project is applying a variety of analyses, including the use of three independently derived watershed models of acidic deposition effects. This article describes the design of the DDRP and presents some of its preliminary products.
The Complex Vocal Repertoire of the Adult Cotton‐top Tamarin (Saguinus oedipus oedipus)1)

Abstract The cotton-top tamarin (Saguinus oedipus oedipus) has an extensive vocal repertoire which is derived from the variation of two basic elements and the sequential combination of those elements. A distinctive features analysis demonstrated at least 8 phonetic variants of a short, frequency modulated call (chirp) and five longer constant frequency calls (whistles). The call variants do not describe points on a single motivational continuum, but rather each variant represents a different message. A simple grammar is presented to describe all sequences of calls. While most of the call sequences fit the definition of phonetic syntax, at least two sequences appear to be exemplars of lexical syntax. Call structures are modified to provide increasing cues for auditory localization as animals are farther apart from each other. Comparisons of calls of S. o. oedipus with those of other callitrichids show a gradual divergence of call type with increasing geographic and phylogenic separation. Zusammenfassung Das Lautrepertoire des Lisztaffchens (Saguinus oedipus) wird beschrieben, einschlieslich der Situationen, in denen die Laute auftreten, und ihres vermuteten Bedeutungsinhalts. Das Repertoire beruht weitgehend auf zwei Grund-Elementen: kurzen frequenzmodulierten “Zirplauten” und langeren unmodulierten “Pfiffen”. Diese Elemente werden zu verschiedenen Varianten mit unterschiedlichen Funktionen umgewandelt. Sie konnen auch zu langeren Folgen (Phrasen) zusammengefugt werden. Dem liegt eine einfache Grammatik zugrunde. Meist haben die Elementfolgen einen anderen Bedeutungsgehalt als die Elemente, aus denen sie bestehen. Es gibt aber auch Folgen, die der Definition einer lexikalischen Syntax genugen, d. h. ihre Bedeutung ist zusammengesetzt aus der Bedeutung der Einzelelemente. Die akustische Struktur der Laute entspricht den von Morton (1977) fur Tierlaute aufgestellten Merkmalen akustischer Kommunikation. Das Lisztaffchen past die Lautstruktur der Entfernung vom Empfanger an. Je groser der Abstand zwischen den Tieren, desto mehr Orientierungshilfen enthalten die Laute. Die Laute sind weitgehend denen gleich, die fur verschiedene Unterarten von S. oedipus beschrieben wurden. Zu Nachbararten und Nachbargattungen wachsen die Unterschiede mit groserer geographischer und taxonomischer Entfernung.
The complete separation of the base, nucleoside, mono-, di-, and triphosphonucleosides of uracil and cytosine by polyethyleneimine cellulose thin-layer chromatography

Abstract A high-resolution thin-layer chromatography procedure for the complete separation and quantitation of the base, nucleoside, mono-, di-, and triphosphonucleosides of uracil and cytosine is presented. The procedure employs polyethyleneimine cellulose plastic-backed plates developed at 0°C in 0.55 m LiCl, 0.2% (v/v) formic acid solvent. The method is particularly useful for the separation of the products and substrates in studies of the pyrimidine salvage enzymes, the pyrimidine nucleotidases, and the pyrimidine nucleotide kinases of minimally purified enzyme preparations.
Antithrombin: Its Physiological Importance and Role in DIC

Antithrombin (AT) is a single-chain glycoprotein in plasma and belongs to the family of the serpins. It is synthesized in liver parenchymal cells, and its plasma concentration is between 112-140 mg/L. AT is a unique inhibitor of the clotting system and neutralizes most of the enzymes generated during activation of the clotting cascade, especially thrombin, factors Xa and IXa. Equimolar, irreversible complexes are formed between AT and the enzymes. The interaction between AT and the activated clotting factors is at least 1,000-fold increased in the presence of heparins. Heparins bind to multiple sites of the AT molecule resulting in a steric reconfiguration. Heparins contain a specific pentasaccharide unit which is the minimum requirement for AT binding. The glycosaminoglycan (GAG) heparan sulfate found on endothelial cell surfaces also contains this pentasaccharide and can thus "activate" AT. It is believed that much of the physiological inactivation of enzymes by AT occurs on the endothelium, mediated by heparan sulfate. The binding of AT to the GAGs also releases prostacyclin which possesses strong antiinflammatory properties. Deficiencies of AT are inherited or acquired. Only acquired defects due to increased consumption are discussed, most notably AT in DIC, especially DIC in sepsis. During acute DIC, clotting factors and inhibitors are consumed faster than they can be reproduced. This consumption of AT is of great significance in DIC and sepsis, and plasma AT levels predict outcome. AT levels drop early in sepsis and laboratory signs of DIC can already be found in patients with SIRS and early sepsis. The important role of AT in DIC and sepsis is the basis for considering antithrombin concentrates as an additional therapeutic modality.
The distribution of tenascin and its transcript in the developing avian central nervous system

I have studied the temporal and spatial regulation of the expression of the extracellular matrix protein tenascin in the developing chick brain using immunological and in situ hybridization methods. Tenascin is barely detectable by immuno-slot blot analysis in the E4 telencephalon, but increases rapidly in abundance until E14, when the level of expression tapers off. The late appearance of tenascin was confirmed by immunohistochemistry. Tenascin can not be detected at E4, but at E7 is distributed homogeneously in most parts of the central nervous system. Tenascin is much less abundant in the retina than in other brain areas. As the avian retina is devoid of both vasculature and fibronectin, this supports the notion that tenascin may mask fibronectin from migrating growth cones and cell bodies. I have also used in situ hybridization with a cDNA probe to determine the origins of tenascin in the developing nervous system. Tenascin transcript is found in regions of glial proliferation and the cell bodies of radial glia. In contrast, tenascin appears to be made by neurons in the retina. As a low-molecular weight splice variant of tenascin is detected on western blots of retina homogenates, different cell types may be responsible for generating the multiple forms of tenascin found in whole brain homogenates.
Stability of Whole Brain and Regional Network Topology within and between Resting and Cognitive States

Background Graph-theory based analyses of resting state functional Magnetic Resonance Imaging (fMRI) data have been used to map the network organization of the brain. While numerous analyses of resting state brain organization exist, many questions remain unexplored. The present study examines the stability of findings based on this approach over repeated resting state and working memory state sessions within the same individuals. This allows assessment of stability of network topology within the same state for both rest and working memory, and between rest and working memory as well.
Platelet monoamine oxidase activity and temperament and personality in adolescent female substance abusers

Abstract Platelet monoamine oxidase (MAO) activities were compared between female adolescent substance abusers and normal control females. No differences were observed on this biochemical trait. The two groups were discriminable on psychosocial, and behavioral adjustment, personality traits measuring aggression, self control, and stress reactivity, and on the temperament constellations of difficult temperament index, dysrythmicity, and difficult affective temperament. Platelet MAO activity was associated with difficult affective temperament only in the substance abuse group but not in the controls, suggesting that this temperament variant and lower MAO activities may comprise one form of predisposition to substance abuse.
Smoker self-identification versus recent smoking among college students.

Background College students who engage in occasional or social cigarette smoking are less likely to identify themselves as smokers and to attempt to quit. This analysis aimed to determine: (1) the correlates of denying being a smoker among students reporting smoking in the past 30 days and (2) if denying this label was related to not attempting to quit smoking in the past 12 months. Methods A total of 9931 students at 14 colleges completed a random sample survey in 2007. Results Of 2255 students reporting having smoked a cigarette in the past 30 days, 50.7% responded No to Do you consider yourself a smoker . Logistic regression indicated that, after controlling for the number of smoking days in the past 30, being younger (OR=0.94, p p =0.004); and consuming alcohol in the previous 30 days (OR=2.14, p =0.03) were correlates of denying being a smoker. Logistic regression indicated that denial was related to not attempting to quit in the past 12 months (OR=1.72, p Conclusions Half of college smokers deny being smokers, particularly those who are younger, male, attending 4-year colleges, and alcohol consumers. Denying being a smoker was associated with not attempting to quit smoking. Therefore, traditional methods of ascertaining smoking status may not be valid in this population. Healthcare providers should more specifically ask students about recent smoking behavior. Further research is needed to develop interventions targeting smoking among this population.
Strangeness production in ultrarelativistic heavy-ion collisions. I. Chemical kinetics in the quark-gluon plasma.

We develop a kinetic theory of chemical reactions in a quark-gluon plasma in order to study the evolution of flavor composition in ultrarelativistic nucleus-nucleus collisions. The rates of production and annihilation of strange-quark pairs are computed in lowest order in perturbation theory assuming local equilibrium with respect to other, more frequent collision processes. Quantum-statistical effects are taken into account. The hydrodynamic equations coupled to the rate equation are derived and solved numerically in a homogeneous plasma, simulating the approach toward complete chemical equilibrium. The corresponding relaxation times are computed.
Factor XI inhibitors

Alloantibody inhibitors to factor VIII or factor IX are well-recognized consequences of replacement therapy in hemophilia. Factor replacement is also a mainstay of treatment for factor XI deficiency, but reports of factor XI inhibitors are anecdotal and few are well characterized. Factor XI
Antheridiol and the oogoniols, steroid hormones which control sexual reproduction in Achlya

The sexual reproductive process in Achlya, a widely distributed genus of saprophytic aquatic fungi, is initiated and coordinated by the steroid hormones, antheridiol and the oogoniols. The discovery of these hormones, and their isolation and structural identification, are reviewed in this paper. Achlya contains a number of sterols, the major one being fucosterol, which serves as the biosynthetic precursor of antheridiol and the oogoniols. The biosynthesis of the hormones is discussed as well as some of their specific functions in the organism.
Chemical selectivity of self-assembled monolayers of calix[4]resorcinarene

Abstract Selective molecular interactions at an interface formed by self-assembly of a macrocyclic synthetic host, calix[4]resorcinarene with four thiol groups (R4SH), are investigated. The recognition of guest adsorbates from aqueous solutions is monitored using surface plasmon resonance (SPR) and the orientation of the guest-molecule is probed using polarization modulation infrared absorption spectroscopy (PM-IRRAS). The experiments reported here demonstrate that the chemical selectivity of self-assembled monolayers (SAMs) of host molecules such as calix[4]resorcinarenes extends to isomers of several different guest molecules. By using structural isomers of guest molecules such as bipyridine and nitrophenol that are multidentate hydrogen bond acceptors, it is shown that geometric match between guest and host molecules is an integral aspect of the recognition phenomena. Results from SPR and PM-IRRAS experiments reported here highlight the interplay between steric size and forces such as hydrogen bonding and hydrophobic interactions. Competitive and sequential adsorption of guest molecules such as α-hydroxy-γ-butyrolactone and 4,4′-bipyridine shows that these guests compete for the same binding sites on the surface and that the interplay between steric size and molecular forces underlies the preferential selectivity of one guest molecule over another.
Hall anomaly in dilute magnetic alloys

Abstract We have calculated the field-dependence of the Hall coefficient of dilute magnetic alloys on the basis of the s — d model. The result shows an anomalous jump somewhat similar to experimental results of Gaidukov.
Some Remarks on Complete Integral Closure

This paper continues an investigation of the complete integral closure of an integral domain which was begun in [2]. We recall that if D is an integral domain with quotient field K then an element x of K is said to be almost integral over D if there exists a nonzero element y of D such that yxn is an element of D for each positive integer n. The set D* of elements of K almost integral over D is called the complete integral closure of D and D is said to be completely integrally closed if D* = D.
Boundary slopes for Montesinos knots

FOR A KNOT K c S3, let S(K) c Q u {CQ} be the set of slopes of boundary curves of incompressible, %incompressible orientable surfaces in the knot exterior, slopes being normalized in the standard way so that a longitude has slope 0, a meridian slope co. These sets S(K) of %slopes are of special interest because of their relation with Dehn surgery and character varieties; see e.g., [2]. The only general results known so far are that S(K) is always finite [S] and contains at least two elements [3], including of course 0 (coming from a minimal genus Seifert surface). Only for special classes of knots has S(K) been determined exactly. For the (p, q) torus knot, S(K) = (0, pq}. For 2-bridge knots, S(K) is an arbitrarily large set of even integers computable via continued fractions [7], A non-integer s for the motivating example (- 2,3,7) we find S(K) = (0, 16, 18; .20). For somewhat more complicated cases, a small computer can do the work rather quickly. Some examples of these computer calculations are given in the last section of the paper. These include the Montesinos knots of I 10 crossings, plus a few other random examples of greater complexity.
SU‐FF‐T‐171: Dose Differences Due to Air Pockets in Mammosite Treatments for Partial Breast Irradiation

Purpose: To evaluate the effect of air pockets on the delivered dose for MammoSite® treatments using Monte Carlo (MC) calculations, conventional treatment planning system (TPS), and TLD measurements. Method and Materials: A solid water phantom was designed and fabricated to simulate a MammoSite® treatment with an air pocket outside the balloon. Dose measurements were performed using TLD‐100s with dimensions of 3 mm × 3 mm × 0.9 mm and sensitivity of ±3%. The phantom was composed of twelve slabs of 30 cm × 30 cm Plastic Water with varying thicknesses to provide different measurement distances from the balloon surface. The balloon volume was 34 cc, with a diameter of 4 cm. No contrast medium was added to the balloon to avoid possible dose effects due to the contrast. Hemisphere‐shaped air pockets with different radii were milled on top of the balloon surface. An MC algorithm with geometric modeling based on the phantom design was created for dose comparison. The dose discrepancies from the TPS, TLD measurements, and MC calculations were compared. Results: For a 25 mm air pocket, measured doses from TLDs at various locations of the customized phantom and MC results agreed with each other. The maximal discrepancy between TLDs and MC at different measured points was 3.68%. Dose differences between TPS and MC calculation at the air pocket was 6.37%, and less than 5% at locations other than air pockets. Doses will also be shown for a larger air pocket (5 mm radius). Conclusion: The air pocket located outside of MammoSite® balloon does affect the dose to surrounding tissue and this dose can be represented using MC calculations.
Understanding Markets as Online Public Places: Insights from Consumers with Visual Impairments

Abstract More than 20% of the U.S. population is composed of people with disabilities. When such people interact with certain marketplaces, such as commercial Web sites, some become “consumers with constraints,” and others become liberated, experiencing the freedom to search for information independently for the first time. While accessibility in physical stores is mandated by the Americans with Disabilities Act, commercial Web sites do not fall under its jurisdiction, because they are not considered “public places.” This research challenges this view and examines whether actual consumers interpret Web sites as public places. The authors examine this question in the context of experiences of consumers with visual impairments in online shopping. The authors apply the concepts of consumer normalcy and consumer vulnerability to the technology acceptance model as theoretical lenses through which to interpret this context. The findings form the basis for recommendations to policy makers to develop and enforce ...
[Comment on] Projection ponderings

I read with interest the article on world projections by F. Webster McBryde (Eos, Dec. 1, 1981, p. 1162). The need for some sort of equal area world map is obvious, and there are many choices available for projections and how to split the different ocean basins. Below are examples of a special mollweide Equal Area Elliptic map that I have found to be convenient for displaying world oceanic data. There are many useful features of the map: (1) Many deep and bottom water characteristics of the world ocean originate in the north and south Atlantic and are carried eastward in the circumpolar current to the other ocean basins. Thus the Atlantic Ocean should be on the left with the other two oceans placed to the east. (2) Each ocean has the same central longitude for the northern and southern hemispheres, minimizing N-S distortions within oceans. Each ocean can be used separately without the strange looking N-S longitude skews that appear in McBryde's Atlantic and Indian ocean maps and also in all three oceans in the familiar University of Chicago Goode base map used by Sverdrup, Fleming, and Johnson (1942). Work begun in a single ocean area can be expanded easily to the other oceans without redoing the original data set (an exercise I went through when switching from a map made on a Pacific Ocean Lambert equal area chart to a world-wide map). (3) The Atlantic-Indian ocean split places the Mediterranean with the Atlantic Ocean and the Red Sea with the Indian Ocean. (4) Latitude lines are straight for easy ocean to ocean comparison. (5) Equations for the mollweide projection are readily available for computer mapping programs, facilitating computer generated oceanographic data fields for contouring. My maps are usually computer plotted 40 inches high for each ocean, contoured, and then reduced by 50% for drafting.
The relative importance of soluble aerosols to spatial and seasonal trends of impaired visibility in the United States

Abstract In the U.S.A., soluble aerosol species are recognized as major contributors to impaired visibility. Visibility impairment caused by soluble aerosols can be estimated using ambient aerosol and relative humidity data with physical optical models. Averaging over annual and seasonal time frames is necessary for an adequate description of average visibility conditions. When soluble aerosols are a large fraction of ambient aerosols, averaging over time requires consideration of the combined distribution of relative humidity and soluble aerosols. Failure to consider the combined distribution can lead to serious underestimates of the average visibility impairment caused by soluble aerosols. The combined distribution of aerosols and relative humidity has been examined at 20 rural sites in the U.S.A. where aerosol and relative humidity monitors were operated concurrently. By doing so, empirical relations between the average relative humidity and average visibility impairment caused by soluble aerosols were derived. These relations are applied to 16 additional aerosol monitoring sites where reliable estimates of annual and seasonal average relative humidities are available, but concurrent relative humidity was not monitored. Thus, spatial and seasonal trends of visibility impairment caused by aerosols and an apportionment to individual species at 36 sites across the U.S.A., including Alaska and Hawaii, are presented.
2-dimethyl- and 2-diethylaminopyridine N-oxide complexes prepared from various cobalt(II) salts

Abstract 2-dimethyl- and 2-diethylaminopyridine N-oxide (DM and DE, respectively) complexes have been formed with CoX2 (X=ClO4, BF4, NO3 and Cl). Although preparative ligand: Co(II) mole ratios were varied, only one unique solid was isolated for each ligand and cobalt salt combination. Characterization of the eight solids was accomplished primarily by partial elemental analyses and infrared and electronic spectra. Compared to 2-methylaminopyridine N-oxide both of these dialkyl ligands tend to bond as bidentate ligands although some of the complexes appear to have the N-oxide bound in both a monodentate and bidentate fashion.
Learning by Doing: Outcomes of an Overseas Summer Project for Teachers

This article is a case study of a five-week summer program for Spanish teachers conducted in Mexico City. Both qualitative and quantitative methods are used in examining outcomes. A comparison of pre- and post-test scores on listening, speaking, reading and writing instruments shows significant progress in these four skills. Information drawn from program evaluations as well as from reports submitted one year later by the participants themselves and by their immediate supervisors help in understanding the contributions of the various features of the program to its success, and to identify long-term results.
PFI in the NHS

The National Health Service (NHS) hospitals in Britain are currently in a state of decay following many years of underinvestment in the estate. The NHS urgently requires billions of pounds of investment ranging from total hospital new builds to small refurbishment of existing facilities. The previous Conservative government put forward the Private Finance Initiative (PFI) as the procurement mechanism to address this problem. The new Labour government currently appear to be committing themselves to the same approach. PFI project sponsors have spent upwards of £30m bidding for around 30 major PFI schemes. Despite this, by the time of the UK election in May 1997 not one scheme had reached financial close and many sponsors were expressing their disillusionment with the process. Unlike PFI on other Government infrastructure and service schemes, each PFI hospital is tendered by a separate Trust with their own limited budgets. Many Trusts have demanded schemes without realising that they cannot afford them and whilst these schemes may work out cheaper than publicly financed hospitals over 30 years or more, charges are higher in the early years. This is primarily due to the market for loans, the conditions attached to these loans in terms of repayment periods and cover ratios, and the requirement of the sponsors to generate a reasonable return on their investment. This paper discusses the major issues and analyses some of the technical financial problems surrounding the PFI in the NHS. The authors draw on practical experience of financial structuring and modelling hospital projects to build a generic model to analyse NHS PFI economics.
Coronary computed tomographic angiography in the emergency room: state of the art

Chest pain is a common complaint in the emergency department often necessitating testing to exclude underlying obstructive coronary artery disease. While the traditional evaluation of patients with suspected acute coronary syndrome often consists of serial electrocardiograms and cardiac biomarkers, followed by selective use of stress testing for further risk stratification, this approach is costly and inefficient. Recently, coronary computed tomographic angiography (CTA) has offered an alternative approach with a high sensitivity and negative predictive value to exclude obstructive coronary artery disease that can rapidly identify patients with low rates of downstream major adverse cardiac events. In this review, the authors provide an overview of available data on the use of CTA for evaluating acute chest pain, while emphasizing its advantages and disadvantages compared to existing strategies. In addition, we provide a suggested algorithm to identify how CTA can be incorporated into the evaluation of acu...
Self Aligned Radiation Hard CMOS/SOS

This paper reports the results of extending previously reported radiation hardening methods to a self-aligned CMOS/SOS process. Over 20 lots of CMOS/SOS circuits have been fabricated with this process. Threshold shifts, after 1 Mrad (Si) Co60 irradiation are ? 1.2V for the n-channel devices and ? 2.7V for the p-channel devices under worst case bias conditions. Several lots of devices have been fabricated with ? 0.7V n-channel shifts and ? 1.2V p-channel shifts under the above radiation and bias conditions. Post-irradiation n-channel back leakage is in the range of .05 to 5 ?A per mil of channel width, the specific value dependent to a considerable extent on quality of the starting SOS material. Electrical parameters and life-test stability are excellent and equal to those obtained with similar, non-radiation-hard processes.
Castration and Medusa: Orlan's Art on the Cutting Edge

French multimedia artist Orlan (b. 1947) literally altered her body and identity in the name of art by undergoing multiple cosmetic surgeries that replaced her features with those from art historical masterpieces. She transformed herself into an objet d'art as well as a site for public debate, thereby injecting a radical sensibility into Western art and its history. The provocative surgeries at the core of Orlan's “carnal art” both exemplify and expand Freud's notion of castration to include the wish to transcend gender and even the body itself. Like Medusa, Orlan confronts us with blinding images that compel us to question our assumptions about art, beauty, gender, identity, and technology. Her project shows us the fate of human embodiment in a posthuman age. In addition to elucidating her social, feminist, and aesthetic agenda, this paper clarifies her personal psychology and her work's effect on the audience.
Wave scattering by inhomogeneous media: efficient algorithms and applications

Abstract We review a new set of algorithms and methodologies for the numerical solution of problems of scattering by complex bodies in three-dimensional space. These methods, which are based on integral equations, high-order integration, fast Fourier transforms and highly accurate high-frequency methods, can be used in the solution of problems of electromagnetic and acoustic scattering by surfaces—even in cases in which the scatterers contain geometric singularities such as corners and edges. In all cases, the solvers exhibit high-order convergence, they run on low memories and reduced operation counts, and they result in solutions with a high degree of accuracy. A class of high-order high-frequency methods currently under development, in turn, are efficient where our direct methods become costly, and they thus lead to an overall computational methodology which is applicable and accurate throughout the electromagnetic spectrum.
Distribution and concentration of PCB in the Hudson river and associated management problems

Abstract The Hudson River is contaminated with PCBs and a remedial program has been formulated by New York State in order to cope with this toxic pollutant. Over $3 million has been spent to document fully the extent of the PCB contamination in the Upper Hudson River. It appears that over 60% of the PCBs in the riverbed are contained within 40 so called “hot spot” areas, that is, those areas that have PCB concentrations greater than 50 ppm. After evaluating all alternatives, the PCB Reclamation Project was formulated which consists of mechanically or hydraulically dredging the 40 “hot spot” areas and placing the contaminated sediments in a encapsulated land burial facility. Such a facility would meet all federal and state criteria for PCBs disposal. New York is seeking to finance this remedial project through the use of federal funds, that could be obtained either through, the Clean Water Act or through special Congressional legislation or through the Superfund Bill, once it is enacted. The PCB Reclamation Project, if funded this spring, as is presently anticipated, could be completed ny 1983.
Hodograph design of lifting airfoils with high critical mach numbers

We wish to construct airfoils that have the highest free-stream Mach number M∞ for a given set of geometric constraints for which the flow is nowhere supersonic. Nonlifting airfoils which maximize M∞ for a given thickness ratio δ are known to possess long sonic segments at their critical speed. To construct lifting airfoils, we proceed under the conjecture that the optimal airfoil satisfying a given set of constraints is the one possessing the longest possible arc length of sonic velocity. A boundary-value problem is formulated in the hodograph plane using transonic small-disturbance theory whose solution determines an airfoil with long sonic arcs. For small lift coefficients, the hodograph domain covers two Riemann sheets and a finite-difference method is used to solve the boundary-value problem on this domain. A numerical integration of the solution around the boundary yields an airfoil shape, and three examples are discussed. The performance of these airfoils is compared with standard airfoils having the same lift coefficient and δ, and it is shown that the calculated airfoils have a 6%–10% increase in critical M∞.
General approach for the synthesis of polyquinenes via the weiss reaction XIII. Aldol approach to fenestranes.

Abstract The acid-catalyzed intramolecular aldol cyclization (HCl/THF; Ac2O) of diketodialdehyde 5 under conditions of thermodynamic (equilibration) control furnished the 8α,12β-diacetoxytetracyclo[5.5.1.04,13.010,13]tridecane-2,6-dione 6 to provide a new entry into [5.5.5.5]fenestanes. The analogous conversion of bisaldehyde 14 into the 2,8-diacetoxytetracyclo[7.5.1.05,15.012,15]pentadecane-10,14-dione system was not successful.