cssi/SciSciGPT-SciSciNet huggingface dataset:
Protection against paraquat-induced injury by exogenous GSH in pulmonary alveolar type II cells

Exogenous GSH provided rat alveolar type II cells with significant protection against injury induced by paraquat. This protection was also observed in cells treated with acivicin to inhibit GSH degradation and buthionine sulfoximine to inhibit GSH synthesis. Exogenous GSH was transported into cells by a Na+-dependent system. Addition of inhibitors of this transport system, γ-glutamyl-glutamate and probenecid, prevented the protection against injury afforded by GSH. Thus, the results indicate that alveolar type II cells can supplement endogenous synthesis of GSH with uptake of exogenous GSH to protect against paraquat-induced injury.
Scanning Electron Microscopes: Is High Resolution Possible?

Experiments with this scanning microscope have produced extremely encouraging results so that we feel Confident in predicting high resolution and high contrast after some obvious modifications are made in the system, such as providing a good objective lens. Experience with conventional lenses indicates that the instrument behaves in a predictable manner and there is no reason to doubt that the resolution can be as good as that of a conventional microscope. The use of quadrupole lenses will depend on calculations now being performed. There is cause for optimism; high resolution may also be possible with this kind of lens. Experience with field emission shows that the technology is not difficult and that there is more than enough current available for any conceivable use. Energy-loss measurements have been made on a variety of materials. It is attractive to consider the possibility of chemical analysis of selected areas of a specimen. We believe that a very crude form of analysis may indeed be possible. The principal advantage of the use of energy-loss techniques, however, may be in the availability of another contrast mechanism. The ability to "see" small details may be considerably enhanced. Finally, we are experimenting with the possibility of using transmitted electrons of different energy losses to produce different colors on a color television display. This should add an extra element to the picture contrast which may be of some value.
Academy of Natural Sciences: Job Cuts

Jocelyn Kaiser's article on job cuts at the Academy of Natural Sciences in Philadelphia (“Philadelphia institution forced to cut curators,” News of the Week, 7 Jan., p. 28) exemplifies a disturbing trend that threatens our understanding of biological diversity. At a time when species are thought
The effect of buffer ions on stearic acid monolayers in relation to foam stability

Abstract Surface pressures and potentials of stearic acid monolayers were measured on buffered subsolutions at various pH values. The molecular area-pH plot for stearic acid monolayers at a surface pressure of 10 dynes/cm showed a maximum at pH 9.0. The surface potentials of stearic acid monolayers also showed a sharp change at about pH 9. The foaming characteristics of decanoic acid were studied at various pH values, which showed that the foam produced at pH 9.0 in tris-HCl buffer had the least stability. It is suggested from surface measurements that the maximum expansion of stearic acid monolayers on tris-HCl buffer at pH 9 is due to maximum repulsion between stearic acid molecules or to penetration of tris ions into the monolayer. This effect also reduces the foam stability of decanoic acid at pH 9.
Temporal Neighborhood Discovery Using Markov Models

Temporal data, which is a sequence of data tuples measured at successive time instances, is typically very large. Hence instead of mining the entire data, we are interested in dividing the huge data into several smaller intervals of interest which we call temporal neighborhoods. In this paper we propose an approach to generate temporal neighborhoods through unequal depth discretization. We describe two novel algorithms (a) Similarity based Merging (SMerg) and, (b) Stationary distribution based Merging (StMerg). These algorithms are based on the robust framework of Markov models and the Markov Stationary distribution respectively. We identify temporal neighborhoods with distinct demarcations based on unequal depth discretization of the data. We discuss detailed experimental results in both synthetic and real world data. Specifically we show (i) the efficacy of our approach through precision and recall of labeled bins, (ii) the ground truth validation in real world datasets and, (iii) knowledge discovery in the temporal neighborhoods such as global anomalies. Our results indicate that we are able to identify valuable knowledge based on our ground truth validation from real world traffic data.
Why are human G-protein-coupled receptors predominantly intronless?

We thank H. Bourne (UCSF), A.M. Campbell (Stanford), S.R. Coughlin (UCSF), J. Jurka (Genetic Information Research Institute), B.K. Kobilka (Stanford), M.A. Krasnow (Stanford), G. Miklos (Neurosciences Research Institute, La Jolla) and L. Stryer (Stanford) for valuable discussions.
A Cognitive Style Perspective on Ethical Questions

Previous research has shown that cognitive style impacts several areas of human behavior of interest to marketers. This article reports the results of an exploratory study testing the proposition that cognitive style can influence one's perceptions of what is and is not a matter of ethics. The findings indicate that cognitive style can play a role in one's perceptions of ethics, and may help further our understanding of the factors that bear on ethical points of view.
Nonsustained ventricular tachycardia and other high-risk predictors following myocardial infarction: Implications for prophylactic automatic implantable cardioverter-defibrillator use

T HE IMPLANTABLE cardioverter-defibrillator is an effective nonpharmacological method for the termination of ventricular tachycardia or ventricular fibrillation. In patients who have survived a previous cardiac arrest, defibrillator therapy is associated with a low incidence of subsequent sudden death (1% to 2% annually)‘-” and is widely advocated as the treatment of choice in this patient subgroup.8T9 Multiplefunction, tiered therapy devices that provide antitachycardia pacing and low-energy shocks have extended the potential applications of the device to patients with recurrent hemodynamitally stable sustained ventricular tachycardia.‘O The use of nonepicardial lead systems,“.” permitting implantation without thoracotomy, has further enhanced patient and physician acceptance of this therapeutic modality. Despite two decades of specialized emergency prehospital care, survival to hospital discharge following out-of-hospital cardiac arrest remains poor, ranging from 2% to 25% (approximately 10% in most communities); survival is determined in part by the extent and sophistication of emergency systems.13-‘” Use of the automatic external defibrillator significantly improved short-term survival in an initial largescale field study.” Further experience with this device in a variety of community settings will be necessary to determine its overall impact on patient salvage. Several recent trials of pharmacological interventions aimed at reducing the incidence of sudden death in high-risk patients have provided discouraging results.rR-iy These observations, combined with the widespread acceptance of defibrillator therapy in patients with prior sustained ventricular arrhythmias, have led to increased interest in the use of the implantable defibrillator as prophylactic therapy in high-risk patients before the first episode of a potentially fatal ventricular tachyarrhythmia. The vast majority of unexpected cardiac arrests and sudden deaths (up to 90%) occur in patients with coronary artery disease.‘OJ A substantial proportion of such deaths occur in patients with previously identified heart disease and evidence of prior myocardial infarction.“-‘4 This latter population thus provides a logical starting point for prophylactic interventions, including the implantable defibrillator. The purpose of this review is to examine the potential role of prophylactic implantable defibrillators in enhancing survival rates in high-risk patients following myocardial infarction. Several factors must be considered in evaluating the feasibility and efficacy of such an approach. First, potential survival benefit is linked to the complex pathophysiology of death following myocardial infarction, including competing risks of death due to arrhythmias, pump failure, and acute myocardial ischemia (and the possibility that the device may merely alter the mode of death). In addition, postinfarction survivors are not a homogeneous group with respect to risk of
The formation of low resistance electrical contacts to shallow junction InP devices without compromising Emitter integrity

An investigation is made into the possibility of providing low resistance contacts to shallow junction InP devices which do not require sintering and which do not cause device degradation even when subjected to extended annealing at elevated temperatures. We show that the addition of In to Au contacts in amounts that exceed the solid solubility limit lowers the as-fabricated (unsintered) contact resistivityR c to the 10-5 ohm-cm2 range. If the In content is made to correspond exactly to that required to form the intermediate compound Au9ln4, then the contacts so formed are stable, both electrically and metallurgically, even after extended annealing (12 hr) at 400° C. We next consider the contact system Au/Au2P3 which has been shown to exhibit as-fabricatedR c values in the 10-6 ohm-cm2 range, but which fails quickly when heated. We show that the substitution of a refractory metal (W, Ta) for Au preserves the lowR c values while preventing the destructive reactions that would normally take place in this system at high temperatures. We show, finally, thatR c values in the 10 ohm-cm2 range can be achievedwithout sintering by combining the effects of In or Ga additions to Au contacts with the effects of introducing a thin Au2P3 layer at the metal-InP interface.
Rapid Assessment of Choice between Cocaine and Food in Rhesus Monkeys: Effects of Environmental Manipulations and Treatment with d -Amphetamine and Flupenthixol

The present study describes a procedure that permits rapid assessment of environmental and pharmacological factors that may influence the choice between cocaine and food in rhesus monkeys. Daily 2 h sessions were divided into five components. During each component, monkeys (N=4) chose between i.v. cocaine (0-0.1 mg/kg/injection) and food (0, 1, or 3 food pellets). Up to 10 reinforcers were available during each component, and different discriminative stimuli were associated with each magnitude of each reinforcer. Cocaine choice was directly related to cocaine dose, and a cocaine choice dose-effect curve could be determined in a single experimental session. The choice between cocaine and food was influenced by the schedules of cocaine and food reinforcement, the magnitude of the food reinforcer, and the amount of noncontingent food provided outside the experimental session. These results confirm and extend previous findings with other choice procedures and validate the sensitivity of the present procedure to environmental manipulations. The choice between cocaine and food could also be influenced by treatment with candidate pharmacotherapies for cocaine abuse and dependence. The "agonist" medication d-amphetamine produced rightward shifts in the cocaine choice dose-effect curve and decreased cocaine choice, whereas the "antagonist" medication flupenthixol had little effect on cocaine choice. Overall, these results suggest that this choice procedure may be useful for the evaluation of both environmental determinants of cocaine use and candidate pharmacotherapies for the treatment of cocaine abuse.
Subcellular localization of chlorosome proteins in Chlorobium tepidum and characterization of three new chlorosome proteins: CsmF, CsmH, and CsmX.

Chlorosomes are unique light-harvesting structures found in two families of photosynthetic bacteria. In this study, three chlorosome proteins (CsmF, CsmH, and CsmX) of the green sulfur bacterium Chlorobium tepidum were characterized by cloning and sequencing the genes which encode them, by overproducing the respective proteins in Escherichia coli, and by raising polyclonal antisera to the purified proteins. Three other proteins (AtpF, CT1970, and CT2144) which were identified in chlorosome fractions have similarly been characterized. The antisera were used to establish the distribution of each protein in various cellular fractions. Ten chlorosome proteins (CsmA, CsmB, CsmC, CsmD, CsmE, CsmF, CsmH, CsmI, CsmJ, and CsmX) copurified in a constant proportion together with bacteriochlorophyll c, and none of these 10 proteins was found in substantial amounts in other subcellular fractions. An antiserum to CsmH was highly effective in agglutinating chlorosomes, and antisera to CsmI, CsmJ, CsmX, and CsmA also imm...
Conformational changes in the A1 domain of von Willebrand factor modulating the interaction with platelet glycoprotein Ibalpha

The interaction between von Willebrand factor (vWF) A1 domain and platelet glycoprotein Ib alpha occurs in the presence of high shear stress or when vWF becomes immobilized onto a surface but not appreciably in the normal circulation. To investigate the structural properties regulating A1 domain function, we have used recombinant fragments prepared either in cyclic form with oxidized Cys509-Cys695 disulfide bond or reduced and alkylated. Interaction with glycoprotein Ibalpha was assessed by testing inhibition of monoclonal antibody LJ-Ib1 binding to platelets and inhibition of shear-induced platelet aggregation mediated by native vWF. Fragments exposed to pH between 2.5 and 3.5 adopted the molten globule conformation with loosened tertiary structure intermediate between native and completely unordered state. Maximal receptor binding activity was observed when fragments kept at acidic pH, particularly after reduction of the Cys509-Cys695 disulfide bond, were subjected to quick refolding by rapid pH increase. In contrast, slow refolding by incremental pH change over several hours resulted in at least 20-fold lower activity. A specific single point mutation (I546V) resulted in enhanced receptor binding, whereas another mutation (S561G) caused markedly reduced binding. These results provide experimental evidence that conformational transitions can modulate function of the vWF A1 domain in solution.
The epistemology of Gorgias’ rhetoric: A re‐examination

Gorgias of Leontini acquired prominence as the title figure in Plato's Gorgias, but the biased characterization presented in this famous dialogue has resulted in a disservice to one of the most innovative theorists in the history of rhetoric. In this study, earlier research is conjoined with an examination of intellectual influences upon Gorgias and interpretative translations of his extant rhetorical fragments. The conclusions of this inquiry indicate that Gorgias developed theories of rhetoric which were predicated upon empirical sense‐perception, deception, probability and antithetical reasoning. The implications of these findings reveal that Gorgias had an epistemology of rhetoric that came from a well‐established philosophical tradition which opposed the basic tenets of Platonism.
The Interarea Matrix: A Tie Line Flow Model for Power Pools

This paper presents a method of modeling the ties and lines in a power pool for use in dispatch, pool costing, and security- related functions. External pool ties, as well as ties and lines, within the pool are modeled. The networks of all pool members as well as those external to the pool are incorporated in the model. The model consists of a matrix whose rows represent ties and lines and whose columns represent generators, loads if explicitly represented, and net interchanges. Both current and power models are given. The current model yields tie currents when postmultiplied by a current vector and the power model yields tie powers when postmultiplied by a power vector. The model allows loads to be treated explicitly, as mentioned above or implicitly, where the load currents or powers are not required for tie flow determinations. Lines within the areas of the pool are included under the tie designation. Off-nominal autotransformers and phase shifters, which represent a difficult case, are rigorously considered.
Viscoelastic Continuum Model of Nonpolar Solvation. 1. Implications for Multiple Time Scales in Liquid Dynamics

A continuum model of nonpolar solvation is presented. Coupling of the solute to the solvent is assumed to occur through a change in the solute's size or shape upon electronic excitation. Both spherical and nonspherical changes in the solute are treated. The time-dependent shear and longitudinal moduli of the solvent determine the solvation response function. Unlike prior continuum models of solvation, both a rapid, viscosity-independent inertial component and a slower, viscosity-dependent diffusive component emerge from the model, even when only one time scale is assumed in the moduli. The origin of multiple time scales in this model, which has a single solvent coordinate with complex dynamics, is contrasted with treatments such as the multimode Brownian oscillator models, which postulate multiple solvent coordinates, each with simple dynamics.
Heterogeneity of S-100 proteins of brain: subunit compositions.

— Two populations of S-100 proteins (III-IVa-1) and (III-IVb-1) were isolated from bovine brain by a simple three-step procedure involving precipitation with ammonium sulfate, ion exchange chromatography and gel electrophoresis. These two fractions reacted with anti-S-100 serum and showed all the properties of S-100 protein, but differed in the distribution of protein among the four subunits obtained in SDS-gels. These subunits had apparent molecular weights of 7800, 6800, 6100, and 5200. Separations based on charge differences revealed only three subunits. Similar fractions isolated from rat brain contained only two subunits with apparent molecular weights of 7800 and 6500. The two S-100 protein fractions also differed in the specific extinction at 280 nm and in the protein distribution among the separate bands which formed either in a 14% acrylamide-agarose gel-discontinuous buffer system or in 7.5% gels in the presence of calcium. The yield of S-100 protein isolated in the presence of aids (EDTA, EGTA, mercaptoethanol, protease inhibitors) was considerably higher than in their absence (80 mg vs 60 mg/kg tissue), the predominant loss occurring in fraction III-IVa-1. It is concluded that 'S-100 protein’contains a number of molecular species which have different subunit compositions and differences in stability.
Oscillation of left ventricular structures in aortic regurgitation

High-frequency diastolic oscillation of the anterior mitral leaflet is a common echocardiographic feature in aortic regurgitation. We have studied a group of 56 patients with aortic regurgitation in whom diastolic oscillation of the anterior mitral leaflet was present. Thirty-one of these had similar diastolic oscillation of the posterior leaflet; occasional patients demonstrated oscillation of the interventricular septum or chordae tendineae. The presence of these diastolic oscillations did not correlate with the presence of the Austin-Flint murmur. We conclude that diastolic oscillation of left ventricular structures other than the anterior mitral leaflet can be recorded on echocardiograms of patients with aortic regurgiation. The mechanism responsible for these oscillations is not known; several possibilities are discussed.
Economic distress and mental health: The role of family coping resources and behaviors

Relationships among economic distress, family coping resources and behaviors, and mental health are examined among a sample of 203 married men and 207 married women. Economic distress is negatively associated with mental health. Although family coping resources are lower among those experiencing economic distress and are generally positively related to mental health, their role as mediators of relationships between economic distress and mental health is limited. Economic distress is positively related to family coping behaviors. However, these behaviors do not have positive relationships with mental health and do not counteract the effects of economic distress on mental health. Some coping resources and behaviors have buffering effects on relationships between economic distress and mental health while others have exacerbating effects.
Investigations of two trigonal (T 1 and T 2 ) Gd 3+ ESR centers in treated alkaline-earth-fluoride crystals

A detailed investigation has been made of the two trigonal ${\mathrm{Gd}}^{3+}$ ESR centers (${T}_{1}$ and ${T}_{2}$) in alkaline-earth-fluoride (Ca${\mathrm{F}}_{2}$, Sr${\mathrm{F}}_{2}$, and Ba${\mathrm{F}}_{2}$) crystals treated with water vapor at high temperatures. We have observed both the ${T}_{1}$ and ${T}_{2}$ centers in all three fluoride crystals. Partially resolved superhyperfine structures have been detected for the first time for the ${T}_{1}$ and ${T}_{2}$ centers. It is established that the charge-compensation structures of the ${T}_{1}$ and ${T}_{2}$ trigonal ${\mathrm{Gd}}^{3+}$ centers are associated with the ${\mathrm{Gd}}^{3+}$ -${\mathrm{F}}^{\ensuremath{-}}$${\mathrm{O}}_{4}^{2\ensuremath{-}}$ and ${\mathrm{Gd}}^{3+}$ -${\mathrm{F}}_{7}^{\ensuremath{-}}$${\mathrm{O}}^{2\ensuremath{-}}$ configurations, respectively.
A global-local finite element method suitable for parallel computations

A global-local finite element analysis procedure is developed based on the fast convergent nature of FEM in displacement. A special scheme is used to utilize the global displacement solution as boundary conditions for local regions of interest. In the local region, a refined mesh is used for further stress analysis. This global-local procedure can be easily programmed in parallel on MIMD multi-processor computers for significant time savings. A Sequent Balance 21000 system is used for demonstrating the parallel programming.
V-cGAPs: attenuators of 3′3′-cGAMP signaling

Cyclic GMP-AMPs (cGAMPs) are new members of the cyclic dinucleotide family of second messenger signaling molecules identified in both bacteria and mammalian cells. A recent study by Gao et al. published in Cell Research has identified and characterized three 3′3′-cGAMP-specific phosphodiesterases (termed as V-cGAP1/2/3) in V. cholerae, thereby providing mechanistic insights into the function of these enzymes that degrade cGAMPs.
Evaluating the performance of detection algorithms in digital mammography.

The initial and relative evaluation of computer methodologies developed for assisting diagnosis in mammography is usually done by comparing the computer output to ground truth data provided by experts and/or biopsy. Reported studies, however, give little information on how the performance indices of computer assisted diagnosis(CAD) algorithms are determined in this initial stage of evaluation. Several strategies exist in the estimation of the true positive (TP) and false positive (FP) rates with respect to ground truth. Adopting one strategy over another yields different performance rates that can be over- or underestimates of the true performance. Furthermore, the estimation of pairs of TP and FP rates gives a partial picture of the performance of an algorithm. It is shown in this work that new performance indices are needed to fully describe the degree of detection (part or whole) and the type of detection (single calcification, cluster of calcifications, mass, or artifact). Several evaluation strategies were tested. The one that yielded the most realistic performances included the following criteria: The detected area should be at least 50% of the true area and no more than four times the true area in order to be considered TP. At least three true calcifications should be detected to within 1 cm 2 with nearest neighbor distances of less than √2 cm for a cluster to be considered TP. Separate detection measures should be established and used for artifacts and naturally occurring structures to maximize the benefits of the evaluation. Finally, it is critical that CAD investigators provide information on the tested image set as well as the criteria used for the evaluation of the algorithms to allow comparisons and better understanding of their methodologies.
The effect of ventricular blood O2, CO2 and pH on diving bradycardia in the bullfrog (Rana catesbeiana)

Abstract 1. 1. Bullfrogs were dived for 30 min in water with O2 saturations of 20% and 5%. 2. 2. Ventricular blood-O2-tension was significantly higher in the group submerged in 50% saturated water. 3. 3. No significant change in ventricular blood-CO2-tension or pH was demonstrated. 4. 4. No significant change in development, depth or release of bradycardia was demonstrated in the two groups. 5. 5. It was concluded that elevation of blood-O2-tension in this study did not affect diving bradycardia. 6. 6. Relatively constant CO2 and pH was attributed to anerobiasis and blood-buffering-capacity.
Multiscale geometric image processing

Since their introduction a little more than 10 years ago, wavelets have revolutionized image processing. Wavelet based algorithms define the state-of-the-art for applications including image coding (JPEG2000), restoration, and segmentation. Despite their success, wavelets have significant shortcomings in their treatment of edges. Wavelets do not parsimoniously capture even the simplest geometrical structure in images, and wavelet based processing algorithms often produce images with ringing around the edges. As a first step towards accounting for this structure, we will show how to explicitly capture the geometric regularity of contours in cartoon images using the wedgelet representation and a multiscale geometry model. The wedgelet representation builds up an image out of simple piecewise constant functions with linear discontinuities. We will show how the geometry model, by putting a joint distribution on the orientations of the linear discontinuities, allows us to weigh several factors when choosing the wedgelet representation: the error between the representation and the original image, the parsimony of the representation, and whether the wedgelets in the representation form "natural" geometrical structures. Finally, we will analyze a simple wedgelet coder based on these principles, and show that it has optimal asymptotic performance for simple cartoon images.
DC leakage and failure of PZT thin film capacitors for non-volatile ferroelectric memory and dram applications

Abstract DC leakge and dielectric breakdown of Pb(ZrxTi1−x)O3 (PZT) thin films have been studied. Three regions in the time spectrum of the DC leakage current are discussed. It is emphasized that it is important to measure the time dependence of current before doing current versus voltage (I–V) measurements. Resistivity degradation is observed after a DC voltage is applied for a certain length of time. It is found that the resistivity degradation is dependent on voltage polarity and humidity of the atmosphere. It is pointed out that the time dependent dielectric breakdown (TDDB) must be distinguished from the phenomenon of resistivity degradation. It is found that breakdown in PZT thin films is defect related. The difficulty of confirming whether the breakdown mechanism is electrical (i.e., intrinsic) or thermal is discussed.
Ian McHarg’s Ecological Planning in The Woodlands, Texas: Lessons Learned after Four Decades

AbstractThe Woodlands, Texas, is well known as a new town development (29,000 acres) that followed Ian McHarg’s ecological planning approach. Primarily by literature review, this paper indicated that early development that followed McHarg’s approach has met the original planning goals to preserve the forest environment and to minimize the development impacts on watershed hydrology. McHarg’s approach was largely abandoned after the ownership change in 1997. Barriers came from each side of the development: homeowner (demand), developer (provider), designer (professional service) and government (policy-maker). The Woodlands’ environmental planning success in early development was also attributed to developer George Mitchell’s personal commitment and financial support, the US Housing and Urban Development’s $50 million loan, and the relatively flexible planning system in the 1970s. However, in the current planning and economic systems, it would be a hard undertaking to replicate McHarg’s ecological planning a...
Field Testing a Metal Bioaccumulation Model for Zebra Mussels

A kinetic model of trace element bioaccumulation in zebra mussels, employing experimentally determined trace element influx and efflux rates following food and water exposures, was field-tested in the Hudson and Niagara Rivers and Lakes Erie and Ontario. Ultraclean measurements of water column trace element concentrations in these waters and on suspended particles were used to predict metal concentrations in zebra mussels that were measured independently by the NOAA Mussel Watch program. Field concentrations of Ag, Cd, Cr, and Hg ranged from subpicomolar (Ag) to low nanomolar (Cr) and displayed partition coefficients between particulate and aqueous phases of 1-20 x 10 5 L kg -1 . Despite variation in bioaccumulation factors (BAF) between locations by up to 6x (for Ag), our model predicted mean body burdens of Ag, Cr, Hg, and Se that differed from measured tissue concentrations at the same sites by only 30% on average. Cd predictions matched measured values at the two lake sites but exceeded measurements atthe three river sites by 2.6-fold. Furthermore, the model predicted that, under all environmental conditions likely to prevail in natural waters, Ag, Cd, and Hg are predominantly accumulated from ingested particles, that Cr is accumulated mostly from the dissolved phase, and that the relative uptake pathway for Se varies with environmental conditions. The highest BAF was for Cd (15-64 x 10 4 ) and the lowest BAFs were for Cr and Se (1.2-2.5 x 10 4 and 0.5-2.8 x 10 4 , respectively), with Ag and Hg being intermediate (2.0-12 x 10 4 and 1.4-25 x 10 4 , respectively). The good agreement of the model with field measurements suggests, for these elements, that (a) accumulation of these elements in zebra mussels is in fact proportional to influx from food and water (that is, the organism is not actively regulating internal concentrations), and (b) we can account for the processes governing metal bioaccumulation in these animals. We conclude that for these elements the zebra mussel will be effective as a bioindicator of ambient metals in freshwater systems.
Effects of morphine on mouse liver and brain ribonuclease and deoxyribonuclease activities

Abstract Attempts have been made to examine the in vitro and the in vivo effects of morphine on ribonuclease (RNase) and deoxyribonuclease (DNase) activities of mouse liver and brain tissues. Morphine in vitro inhibits liver and brain RNase and brain DNase activities by about 20%. The acute administration of morphine parallels its in vitro effects as above. Chronic administration of morphine causes general decreases in specific activities of RNase and DNase in both liver and brain cells and in their subcellular fractions, such as nuclei, mitochondria, microsomes, and soluble supernatants.
Silicon tetrafluoride on Io

Abstract Silicon tetrafluoride (SiF 4 ) is observed in terrestrial volcanic gases and is predicted to be the major F-bearing species in low-temperature volcanic gases on Io [Schaefer, L., Fegley Jr., B., 2005b. Alkali and halogen chemistry in volcanic gases on Io. Icarus 173, 454–468]. SiF 4 gas is also a potential indicator of silica-rich crust on Io. We used F/S ratios in terrestrial and extraterrestrial basalts, and gas/lava enrichment factors for F and S measured at terrestrial volcanoes to calculate equilibrium SiF 4 /SO 2 ratios in volcanic gases on Io. We conclude that SiF 4 can be produced at levels comparable to the observed NaCl/SO 2 gas ratio. We also considered potential loss processes for SiF 4 in volcanic plumes and in Io's atmosphere including ion–molecule reactions, electron chemistry, photochemistry, reactions with the major atmospheric constituents, and condensation. Photochemical destruction ( t chem ∼266 days) and/or condensation as Na 2 SiF 6 (s) appear to be the major sinks for SiF 4 . We recommend searching for SiF 4 with infrared spectroscopy using its 9.7 μm band as done on Earth.
The role of intravascular devices in sepsis

Intravascular devices (IVDs) are widely used in modern day health care. Unfortunately, their use is associated with substantial risk of bloodstream infection (BSI) and sepsis, with increased hospitalization and hospital mortality. IVDs are the most common cause of nosocomial BSI. The wider use of new methodologies for diagnosis of IVD-related infection should allow earlier and more focused therapy and, especially, improve the accuracy of surveillance. Of all nosocomial infections, IVD-related BSIs are most amendable to prevention.
Deformation Paths in Structural Geology

The evolution of folds and the origin of mineral orientations and schistosity are analytically related to the deformation paths or histories in deforming rocks. The several different finite and incremental methods of representing deformation paths are connected by matrix algebra, and graphical presentation in natural strain space is found to be particularly clear. New methods permit calculation of various components of deformation paths from boudinage, pressure shadows, and inclusion trails in naturally deformed metamorphic rocks. In coaxially accumulating deformation paths the principal strains remain parallel to the same material lines in the rock and have been referred to inappropriately as irrotational. Straight inclusion trails in metamorphic minerals may be produced by synkinematic grain growth during a coaxially accumulating path and do not necessarily indicate postkinematic grain growth. Synkinematic inclusion trails can be produced by growth of the grain through its pressure shadow rather than matrix schistosity, and the quartz protected from re-crystallization by being included in snowball garnets may sometimes form this way.
Prediction of fishing effort distributions using boosted regression trees

Concerns about bycatch of protected species have become a dominant factor shaping fisheries management. However, efforts to mitigate bycatch are often hindered by a lack of data on the distributions of fishing effort and protected species. One approach to overcoming this problem has been to overlay the distribution of past fishing effort with known locations of protected species, often obtained through satellite telemetry and occurrence data, to identify potential bycatch hotspots. This approach, however, generates static bycatch risk maps, calling into question their ability to forecast into the future, particularly when dealing with spatiotemporally dynamic fisheries and highly migratory bycatch species. In this study, we use boosted regression trees to model the spatiotemporal distribution of fishing effort for two distinct fisheries in the North Pacific Ocean, the albacore (Thunnus alalunga) troll fishery and the California drift gillnet fishery that targets swordfish (Xiphias gladius). Our results suggest that it is possible to accurately predict fishing effort using < 10 readily available predictor variables (cross-validated correlations between model predictions and observed data -0.6). Although the two fisheries are quite different in their gears and fishing areas, their respective models had high predictive ability, even when input data sets were restricted to a fraction of the full time series. The implications for conservation and management are encouraging: Across a range of target species, fishing methods, and spatial scales, even a relatively short time series of fisheries data may suffice to accurately predict the location of fishing effort into the future. In combination with species distribution modeling of bycatch species, this approach holds promise as a mitigation tool when observer data are limited. Even in data-rich regions, modeling fishing effort and bycatch may provide more accurate estimates of bycatch risk than partial observer coverage for fisheries and bycatch species that are heavily influenced by dynamic oceanographic conditions.
Sub-National Movements and the Framing of Regional Trade Agreements: Evidence from the EU and NAFTA

How have secessionist and autonomous movements reacted to regional trade agreements (RTAs)? Existing research focuses on the European Union (EU) and, taking a top-down perspective, argues that the EU has done little to help those movements affirm themselves. Adopting a more bottom-up and comparative approach, we propose that RTAs have functioned as political opportunity structures at the international level and that movements have skillfully framed them to define for themselves and their audiences, their grievances, identity, and vision for the future. Movements have followed two basic approaches. Some have embraced RTAs to denounce the debilitating grips of national governments on their people, project an image of themselves as cosmopolitan and modern players, and depict a future in which their communities thrive as successful players in the international community. Others have rejected RTAs to make clear what is wrong and corrupt about the world, present themselves as protectors of local identities and ...
External Sources of Water for Mercury's Putative Ice Deposits☆

Radar images have revealed the possible presence of ice deposits in Mercury's polar regions. Although thermal models indicate that water ice can be stable in permanently shaded regions near Mercury's poles, the ultimate source of the water remains unclear. We use stochastic models and other theoretical methods to investigate the role of external sources in supplying Mercury with the requisite amount of water. By extrapolating the current terrestrial influx of interplanetary dust particles to that at Mercury, we find that continual micrometeoritic bombardment of Mercury over the last 3.5 byr could have resulted in the delivery of (3-60) x 10(exp 16) grams of water ice to the permanently shaded regions at Mercury's poles (equivalent to an average ice thickness of 0.8-20 m). Erosion by micrometeoritic impact on exposed ice deposits could reduce the above value by about a half. For comparison, the current ice deposits on Mercury are believed to be somewhere between approx. 2 and 20 m thick. Using a Monte Carlo model to simulate the impact history of Mercury, we find that asteroids and comets can also deliver an amount of water consistent with the observations. Impacts from Jupiter-family comets over the last 3.5 billion years can supply (0.1-200) x 10(exp 16) grams of water to Mercury's polar regions (corresponding to ice deposits 0.05-60 m thick), Halley-type comets can supply (0.2-20) x 10(exp 16) grams of water to the poles (0.07-7 m of ice), and asteroids can provide (0.4-20) x 10(exp 16) grams of water to the poles (0.1-8 m of ice). Although all these external sources are nominally sufficient to explain the estimated amount of ice currently at Mercury's poles, impacts by a few large comets and/or asteroids seem to provide the best explanation for both the amount and cleanliness of the ice deposits on Mercury. Despite their low population estimates in the inner solar system, Jupiter-family comets are particularly promising candidates for delivering water to Mercury because they have a larger volatile content than asteroids and more favorable orbital and impact characteristics than Halley-type comets.
Effect of Daily Application of Fluoride in a Custom Fitted Mouthpiece on Plaque Flora Associated with Dental Decay

Plaque samples examined before and after daily application of acidulated fluoride gel in custom fitted mouthpieces showed no changes in the prevalence of organisms in selected bacterial categories associated with dental decay.
The efficiency of translation termination is determined by a synergistic interplay between upstream and downstream sequences in Saccharomyces cerevisiae.

Abstract In a recent study we found that the efficiency of translation termination could be decreased several hundred fold by altering the local sequence context surrounding stop codons in the yeastSaccharomyces cerevisiae. Suppression of termination was shown to be mediated by near-cognate tRNA mispairing with the termination codon. We have now examined in greater detail how the local sequence context affects the efficiency of translation termination in this organism. Our results indicate that the sequence immediately upstream of the termination codon plays a significant role in determining the efficiency of translation termination. An extended termination sequence (containing the stop codon and the following three nucleotides) was also found to be a major determinant of termination efficiency, with effects attributable to the fourth nucleotide being largely independent of the termination codon. For the UGA and UAA stop codons, the influence of the fourth position on termination efficiency (from most efficient to least efficient termination) was found to be G>U,A>C, while for the UAG codon it was U,A>C>G. These sequence-specific effects on the efficiency of translation termination suggest that polypeptide chain release factor (or another molecule that may play a role in translation termination, such as rRNA) recognizes an extended termination sequence in yeast. A previous study found a statistically significant bias toward certain tetranucleotide sequences (containing the stop codon and the first distal nucleotide) in several organisms. We found that tetranucleotide sequences most frequently used in yeast are among the most efficient at mediating translation termination, while rare tetranucleotide sequences mediate much less efficient termination. Taken together, our results indicate that upstream and downstream components of an extended sequence context act synergistically to determine the overall efficiency of translation termination in yeast.
Some results on matrix monotone functions

Abstract Let A and B be Hermitian matrices. We say that A⩾B if A−B is nonnegative definite. A function ƒ:(0,∞) → R is said to be matrix monotone (m.m.) if A⩾B⩾0 implies that ƒ(A) ⩾ ƒ(B) . Matrix convex and concave functions can be similarly defined. In this paper, several known results (some in sharper forms) are given alternative proofs. These include the following: (a) A positive function ƒ(t) is m.m. iff t ƒ(t) is m.m. (b) If ƒ(t) is m.m., then both tƒ(t) and ƒ(t) t are matrix convex and are almost always strictly convex; on the other hand, ƒ(t) is always concave and almost always strictly concave. The concavity of m.m. functions and an inequality of Hansen are consequences of a more general inequality on m.m. functions. Some complementary inequalities are also established. We then prove an extension of Lyapunov's theorem. Let A and P be positive definite matrices and either ƒ or 1 ƒ be a m.m. function; then the unique matrix solution X of the matrix equation AX + XA = ƒ(A)P + Pƒ(A) is positive definite. A similar result holds for a related equation. Most of the results are obtained by exploiting the integral representation of m.m. functions.
Preliminary Thermal Analysis of a Mars Sample Return Earth Entry Vehicle

Thermal analysis of a vehicle designed to return samples from another planet, such as the Earth Entry vehicle for the Mars Sample Return mission, presents several unique challenges. The scientific purpose of a sample return mission is to return samples to Earth for detailed investigation. The Earth Entry Vehicle (EEV) must contain the samples after they have been collected and protect them from the high heating rates of entry into the Earth''s atmosphere. This requirement necessitates inclusion of detailed thermal analysis early in the design of the vehicle. This paper will describe the challenges and solutions for a preliminary thermal analysis of an Earth Entry Vehicle. The primary challenges included accurate updates of model geometry, applying heat fluxes that change with position and time during exo-atmospheric cruise and entry, and incorporating orthotropic material properties. Many different scenarios were evaluated for the exo-atmospheric cruise to attain the desired thermal condition. The severity of the heat pulse during entry and the material response led to some unique modeling solutions. Overall, advanced modeling techniques and mathematical solutions were successfully used in predicting the thermal behavior of this complex system.
The benefits of the explanation of the risks of anesthesia in the day surgery patient

Abstract Study Objective: To ascertain the benefits of the preoperative discussion of the risks of anesthesia with parents of ASA status I or II pediatric day surgery patients. Design: Survey analysis. Setting: Pediatric day surgery unit. Patients: 54 parents of ASA status I or II pediatric day surgery patients between the ages of 7 months and 16 years. Interventions: After informed consent for the anesthetic was obtained by a member of the anesthesiology team, the parent(s) were given a questionnaire on their feelings about the explanation of the risks of anesthesia. Measurements and Main Results: The questionnaire evaluated how parents felt about their understanding of the risks of anesthesia, the effect of hearing the risks of anesthesia on their anxiety levels, and the benefits of hearing the risks of anesthesia. Over 90% of the parents felt that they understood the risks of anesthesia, that the discussion of the risks would have no effect on their decision to proceed with surgery, and that the explanation of the risks is desirable; 92% considered the explanation desirable either out of a sense of responsibility or because they welcomed better understanding. Conclusions: Our study suggests the benefits of the explanation of the risks of anesthesia appear to be rooted in satisfying parental responsibility and understanding, and not in providing information for decision making or anxiety relief. Anesthesiologists should not feed compelled to always detail all the risks, but should seek to satisfy individual parental needs.
Graphical development tools for network-based concurrent supercomputing

This paper describes an X-window based software environment called HeNCE (Heterogeneous Network Computing Environment) designed to assist scientists in developing parallel programs that run on a network of computers. HeNCE is built on top of a software package called PVM which supports process management and communication between a network of heterogeneous computers. HeNCE is based on a parallel programming paradigm where an application program can be described by a graph. Nodes of the graph represent subroutines and the arcs represent data dependencies. HeNCE is composed of integrated graphical tools for creating compiling executing and analyzing HeNCE programs.
Thermal Capacity of Vitreous Silica

It is assumed that the atoms in vitreous silica can be regarded as independent oscillators. Each silicon atom is taken as having three independent equal frequencies and each oxygen as having two equal transverse frequencies and one different longitudinal frequency. Reasonable values assigned to these frequencies give a calculated thermal-capacity curve which is a fairly good approximation of the experimental curve except at very high and very low temperatures. These data also throw light on the reason for the very low thermal expansion of vitreous silica.