cssi/SciSciGPT-SciSciNet huggingface dataset:
Error estimate for the modified Newton method with applications to the solution of nonlinear, two-point boundary-value problems

The solution of nonlinear, two-point boundary value problems by Newton's method requires the formation and factorization of a Jacobian matrix at every iteration. For problems in which the cost of performing these operations is a significant part of the cost of the total calculation, it is natural to consider using the modified Newton method. In this paper, we derive an error estimate which enables us to determine an upper bound for the size of the sequence of modified Newton iterates, assuming that the Kantorovich hypotheses are satisfied. As a result, we can efficiently determine when to form a new Jacobian and when to continue the modified Newton algorithm. We apply the result to the solution of several nonlinear, two-point boundary value problems occurring in combustion.
Objective assessment of image quality and dose reduction in CT iterative reconstruction

Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality.
The Systems ZnO‐Fe2O3‐SnO2 and MgO‐Fe2O3‐SnO2 at 1060°C

Zn2SnO4, an inverse spinel, and ZnFe2O4, a normal spinel, form a complete series of solid solutions in the system ZnO-Fe2O33nO2. The variation of cell dimensions with composition varies from 0.8439 nm (ZnS2nO4) to 0.8660 nm (ZnS2nO4) and exhibits a positive deviation from a linear relationship. Mg2SnO4 and MgFe2O4, both predominantly inverse in nature, have only an incomplete series.
Imaging Surveillance of Differentiated Thyroid Cancer

Intensive imaging surveillance has resulted in the ability to detect small-volume, often clinically occult, residual or recurrent disease. For most patients with differentiated thyroid cancer (DTC), such findings are unlikely to have an impact on disease-specific survival but our ability to predict which patients are at greatest risk and should receive the most aggressive therapies is surpassed by our ability to detect recurrence. Thus, the optimal treatment and surveillance regimens will surely continue to evolve as our ability to predict tumor behavior and aggressiveness improves. This article explains the rationale underlying current surveillance strategies and the utility and implications of imaging findings that are critical for the appropriate care of patients with DTC.
Molecular cloning and characterization of the neonatal rat and mouse submandibular gland protein SMGC

We report the molecular cloning and characterization of SMGC, a major secretory product and a marker of the type I (terminal tubule) cells of the neonatal rat and mouse submandibular gland. SMGC is expressed in the submandibular gland at high levels through postnatal day 20, but in the adult is present only in some intercalated duct cells. Rat and mouse SMGC have deduced molecular weights of 67.8 and 74.4 kDa, respectively, are 37% Ser+Gly+Thr, and contain tandem repeats of between 8 and 60 amino acids. Secreted SMGC visualized by SDS-PAGE and silver staining is 89 kDa in rat and 105 kDa in mouse, although Western blot analyses with anti-SMGC antisera demonstrate multiple additional lower molecular weight forms. Contributions to the heterogeneity of SMGC include alternate splicing, proteolysis and N-glycosylation. Smgc is localized on rat chromosome 7q34-35 and on mouse chromosome 15E3, both immediately upstream of the high molecular weight salivary mucin, Muc19. Amino acid sequence identity between the signal peptides of SMGC, human MUC19 and pig submaxillary mucin suggest that rat and mouse Smgc and Muc19 arose from a single ancestral mucin gene.
Effect of Fatigue Damage in Woven Composites on Thermo-Mechanical Properties and Residual Compressive Strength

The long term mechanical and thermal fatigue of a Celion G30-500/ PMR-15 woven composite system is investigated to study the interrelationship between thermo-mechanical properties, namely the thermal expansion coefficent (TEC) and the compressive strength. Qualitative trends in the experimental data generated by either thermal or mechanical loadings are shown to be similar to properties predicted by a shear lag based model. Residual compressive strength measurements (IITRI fixture) conducted on specimens subjected to tension-tension fatigue cycling indicate that this material property is sensitive to cracks and delaminations which form during mechanical cycling. Measured compressive strength degradation is as large as 49% for this material undergoing mechanical fatigue cycling with TEC degradation as large as 61%. Experimental results show that a correlation exists between TEC measurements and compressive strength. This correlation suggests that TEC measurements may be used as a damage evaluation technique.
Predictable Chronic Mild Stress Improves Mood, Hippocampal Neurogenesis and Memory

Maintenance of neurogenesis in the adult hippocampus is important for functions such as mood and memory. As exposure to unpredictable chronic stress (UCS) results in decreased hippocampal neurogenesis, enhanced depressive- and anxiety-like behaviors and memory dysfunction, it is believed that declined hippocampal neurogenesis mainly underlies the behavioral and cognitive abnormalities after UCS. However, the effects of predictable chronic mild stress (PCMS) such as the routine stress experienced in day-to-day life on functions such as mood, memory, hippocampal neurogenesis are unknown. Using forced swim and elevated plus maze tests in a prototype of adult rats, we demonstrate that PCMS (comprising 5 minutes of daily restraint stress for 28 days) decreases depressive- and anxiety-like behaviors for prolonged periods. Moreover, we illustrate that decreased depression and anxiety scores after PCMS are associated with ~1.8 fold increase in the production and growth of new neurons in the hippocampus. Additionally, we found that PCMS leads to enhanced memory function in water maze as well as novel object recognition tests. Collectively, these findings reveal that PCMS is beneficial to the adult brain function, which is exemplified by an increased hippocampal neurogenesis and an improved mood and cognitive function.
Phospholipid metabolism in livers of young and old fisher 344 and Sprague-Dawley rats

Abstract The levels and fatty acid spectra of liver phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, lysophosphatidyl choline and sphingomyelin were compared in 3-, 12- and 18-month-old Fisher 344 and Sprague-Dawley rats. Levels of phosphatidyl choline, phosphatidyl serine plus inositol and phosphatidyl ethanolamine were significantly higher in livers of Sprague-Dawley rats. Although there were strain-related differences in phospholipids, there were no age-related differences. The ratio of polyunsaturated/saturated fatty acids was higher in the phospholipids of young Fisher 344 rats. Choline kinase activity was (20–40%) higher in the livers of Fisher 344 rats, but activities of sphingomyelinase and of dihydrosphingosine biosynthesis were not significantly different from those of Sprague-Dawley rats.
Airborne Starch Granules as a Potential Contamination Source at Archaeological Sites

Abstract Well-known allergy literature attests to a presence of airborne starch granules from human and natural activities and illustrates that starch granules within pollen grains from starch-rich plants are released when pollen grains rupture in mid-air during thunderstorms. This study reports on starch granules extracted from Texas air samples and ruptured pollen grains from seven ethnographically important geophyte species, as well as maize (Zea mays L.). Starch granules from pollen grains are compared to those in storage organs of these plants. Results confirm that storage-like starch granules are airborne and that starch granules inside pollen can be indistinguishable from starch granules in the respective storage organs.
VALIDITY GENERALIZATION RESULTS FOR LAW ENFORCEMENT OCCUPATIONS

The Schmidt-Hunter interactive validity generalization procedure was applied to validity data for cognitive abilities tests for law enforcement occupations. Both assumed artifact distributions, and distributions of artifacts constructed from information contained in the current sample of studies were used to test the hypothesis of situational specificity and to estimate validity generalizability. Results for studies using a criterion of performance in training programs showed that validities ranged from .41 to .71, and for four test types the hypothesis of situational specificity could be rejected using the 75% decision rule. For the remaining test types, validity was generalizable, based on 90% credibility values ranging from .37 to .71. Results for studies using a criterion of performance on the job indicated that the hypothesis of situational specificity was not tenable for three test types, which had validities between .17 and .31. For the remaining test types, estimated mean true validities ranged from .10 to .26 and were generalizable to a majority of situations. Results for both groups of studies were essentially identical for the two types of artifact distribution. Possible reasons for the apparently lower validities and lesser generalizability for job performance criteria are discussed, including possible low validity of the criterion (due to lack of opportunity by supervisors to observe behavior) and the potential role of noncognitive factors in the determination of law enforcement job success. Suggestions for specifically targeted additional research are made.
A Practitioner's Guide to Estimation of Random-Coefficients Logit Models of Demand

Estimation of demand is at the heart of many recent studies that examine questions of market power, mergers, innovation, and valuation of new brands in differentiated-products markets. This paper focuses on one of the main methods for estimating demand for differentiated products: randomcoefecients logit models. The paper carefully discusses the latest innovations in these methods with the hope of increasing the understanding, and therefore the trust among researchers who have never used them, and reducing the difeculty of their use, thereby aiding in realizing their full potential.
The Relative Importance of Clouds and Sea Ice for the Solar Energy Budget of the Southern Ocean

Abstract The effects of clouds and sea ice on the solar radiation budget are determined for the Southern Ocean around Antarctica between latitudes 50° and 80°S. Distributions of cloud optical depth are used, together with distributions of surface albedo, to estimate the geographical and seasonal variations of shortwave irradiance and cloud radiative forcing at the surface, both for the present climate and for altered surface and cloud conditions. Poleward of 68°S in spring, ice causes a greater reduction of solar energy input to the surface than does cloud. However, in summer the clouds are more important than ice at all latitudes in the Southern Ocean. In the present climate the clouds are optically thicker over open water than over sea ice, suggesting a possible negative feedback if the sea ice area shrinks with climatic warming. Compared to the present climate in spring, removing sea ice results in an increase in irradiance reaching the ocean surface, regardless of the type of cloud remaining. However,...
The comparative effects of some phlorizin analogs on the renal reabsorption of glucose.

Abstract A number of glycosides structurally related to phlorizin have been tested for biological activity. Their influence on the renal tubular reabsorption of glucose in the dog has been compared with the inhibitory capacity exhibited by phlorizin. Some conclusions concerning the nature of the critical structural and geometrical configuration of the inhibitor molecule are presented. Some information has been obtained on the mechanism of phlorizin inhibition at a molecular level and on the nature and topography of the chemical groups constituting the receptor site on the cell membrane to which the inhibitor is bound.
Myosin and kinesin: mother and child reunited

The recent solution of the crystal structure of the kinesin motor domain reveals striking similarities to the core region of the myosin motor domain, implying a strong evolutionary relationship between these two motors. However, a complete understanding of the way that motility is generated will require additional structural information, which may explain how the two motors have adapted to their fundamentally different linear substrates, F-actin and microtubules.
Health Communication as Negotiation: The Healthy America Act

Health communication as a field has a wide array of “experts” in the government, the academic community, the media, and all those in the modern-day health polity. With such a wide knowledge base, many prospects for health communication in the 21st century abound as we enter a new communication and technological age. This article outlines a proposed Healthy America Act, grounded in a shared decision-making model of COAST[UNKNOWN] (communication, options, alternatives, standards, and trust). This workable integrative negotiation (WIN[UNKNOWN]) model approach to health communication outlines a method that all sectors of society can employ to attain optimal health of the citizenry.
Disruption of Cell Volume Regulation by Mercuric Chloride Is Mediated by an Increase in Sodium Permeability and Inhibition of an Osmolyte Channel in Skate Hepatocytes

Abstract The mechanism by which mercury leads to cell swelling and impairs the normal regulatory volume decrease (RVD) in cells swollen in hypotonic media was examined in hepatocytes isolated from the little skate, Raja erinacea, an osmoconforming marine elasmobranch. Skate hepatocytes treated with 50 μ M HgCl 2 in isotonic medium swelled to volumes double those of control cells, and this was associated with an increase in Na + and K + permeability. The gain in intracellular Na + exceeded the K + loss by 0.27 μEq/mg protein, accounting in large part for the observed cell swelling. The effects of mercury were blunted when hepatocytes were incubated in medium in which the Na + was replaced with K + , and were essentially absent when Na + was replaced with choline + , indicating an important role of Na + influx in mediating mercury's effects on cell volume regulation. The inhibition of RVD by mercury was prevented if the metal was administered as a mercaptide with dithiothreitol or glutathione. However, when these chelating agents were added after the mercury, only the membrane permeant dithiothreitol was able to reverse the inhibition of RVD, suggesting an intracellular site of action. Mercuric chloride also produced a concentration-dependent inhibition of the ATP-sensitive volume-regulatory osmolyte channel in skate hepatocytes, as assessed by inhibition of swelling-activated [ 14 C]taurine efflux. [ 14 C]Taurine efflux was inhibited at mercury concentrations (20–40 μ M ) that had no effect on intracellular ATP levels or ATP/ADP ratios, consistent with a direct interaction with the channel. These findings indicate that mercury impairs cell volume regulation in skate hepatocytes at multiple sites, including the volume-regulatory osmolyte channels, and Na + and K + permeability pathways. The combined effects of increased Na + influx and the inability to extrude organic osmolytes may account for the inhibition of RVD.
The sunflower (Helianthus annuus) in Mexico: further evidence for a North American domestication

I have concluded that my initial verification of a specimen recovered from the San Andres archaeological site in Mexico as domesticated sunflower was incorrect. The specimen in question is most likely the seed of a bottle gourd. As yet there is no compelling evidence that the sunflower was grown as a food crop in Mexico prior to European contact. In addition, the complete absence of any early historical record for the sunflower in Mexico argues against its presence in pre-Columbian times. Although no dates or boundaries can be set, the wild sunflower may have grown in northernmost Mexico in early times. A southward range expansion for the species is probably very recent, perhaps in the last few hundred years with the development of a modern road system. The widely used common names of the sunflower in Mexico are in Spanish or with Spanish words in them, which suggests that the sunflower is a post-contact arrival.
Sidewall faceting and inter-facet mass transport in selectively grown epitaxial layers on SiO2-masked Si(1 1 0) substrates

Abstract The facet formation and inter-facet mass transport in selective epitaxial growth (SEG) of Si on SiO 2 -masked growth windows aligned along [1 1 0] and [1 0 0] directions on Si(1 1 0) substrates by Si gas-source molecular-beam epitaxy were studied. For the sidewalls along the [1 1 0] baseline, both (3 1 1) and (1 1 1) facets were formed, while for the sidewalls along the [1 0 0] baseline, (1 0 0) facets were formed. Mass accumulation around the edges of the top surface was shown to be due to the inter-facet mass transport from the sidewall to top surfaces.
High-voltage picosecond photoconductor switch based on low-temperature-grown GaAs

A GaAs material grown by molecular beam epitaxy at a low substrate temperature was used to fabricate a photoconductor switch that produces 6-V picosecond electrical pulses. The pulses were produced on a microwave coplanar-strip transmission line lithographically patterned on the low-temperature (LT) GaAs. A 150-fs laser pulse was used to generate carriers in the LT GaAs gap between the metal strips, partially shorting a high DC voltage placed across the lines. The 6-V magnitude of the electrical pulses obtained is believed to be limited by the laser pulse power and not by the properties of the LT GaAs. Experiments were also performed on a picosecond photoconductor switch fabricated on a conventional ion-damaged silicon-on-sapphire substrate. Although comparable pulse durations were obtained, the highest pulse voltage achieved with the latter device was 0.6 V. >
Spectrum of two-photon absorption coefficients for ZnGeP2

For the first time we have measured the spectrum of two-photon absorption coefficients in the range of 0.76-1.33 μm on ZnGeP2 based on z-scan technique. We have compared our measured values with calculations.
A mechanistic study of oxygen transfer in aqueous systems

Oxygen transfer coefficients were evaluated for a 14-liter stirred tank fermentor equipped with an oxygen probe, employing elemental copper adsorbed on a weakly basic anion-exchange resin as a solid phase oxygen acceptor. The use of a solid phase oxygen acceptor allowed evaluation of mass transfer resistances associated with the solid phase, and the effect of an oxygen adsorbing solid phase on the overall oxygen transport system, portions of the oxygen transfer process that are neglected by the conventional sulfite oxidation method commonly employed. It was concluded from the data obtained that a transport pathway involving transfer of oxygen to particles present near the air-water interface was a significant oxygen transport pathway for the system studied. Oxygen probe measurements performed on the bulk liquid did not recognize this pathway, suggesting that data taken on biological systems by use of techniques involving oxygen concentration measurements in the bulk liquid may not give the true oxygen absorbing capacity of a system.
Evidence for a pressure-induced magnetic-nonmagnetic transition of Pr impurities in La

The depression of the superconducting transition temperature of lanthanum due to the presence of praseodymium impurities shows a pronounced maximum as a function of pressure at approx. =230 kbar. We conclude that the 4f/sup 2/ shell of Pr delocalizes under such high pressure and hence demagnetizes in analogy to the familiar case of the 4f/sup 1/ configuration of Ce impurities in La at low pressure.
Coefficients Alpha, Beta, Omega, and the glb: Comments on Sijtsma

There are three fundamental problems in Sijtsma (Psychometrika, 2008): (1) contrary to the name, the glb is not the greatest lower bound of reliability but rather is systematically less than ωt (McDonald, Test theory: A unified treatment, Erlbaum, Hillsdale, 1999), (2) we agree with Sijtsma that when considering how well a test measures one concept, α is not appropriate, but recommend ωt rather than the glb, and (3) the end user needs procedures that are readily available in open source software.
The source abundances of cosmic ray nuclei

Abstract A survey of the present state of attempts to deduce the abundances of nuclei at the sources of the cosmic radiation from the abundances measured near the earth. Particular attention is directed towards the effects that are introduced by the energy-dependent cross-sections for the production of fragments due to interactions in the interstellar medium. It is pointed out that the energy history of the cosmic ray nuclei is quite uncertain, due to the uncertain nature of the interstellar medium, possible effects of re-acceleration during propagation and the spread in energies introduced by solar modulation. These factors limit the precision with which source abundances can be deduced no matter how accurately the local abundances are measured, unless these abundances are measured at energies at which the cross-sections do not vary with energy.
Self-Efficacy Correlates With Leg Muscle Pain During Maximal and Submaximal Cycling Exercise

Abstract Quadriceps muscle pain is a naturally occurring consequence of moderate- to high-intensity cycle ergometry. The present study involved an examination of self-efficacy for tolerating muscle pain during exercise as a correlate of muscle pain during maximal and submaximal cycle ergometry. Young adult females (n = 16) who were healthy and regularly physically active completed a measure of self-efficacy for tolerating moderate to strong pain in the legs and then undertook a maximal incremental exercise test on a cycle ergometer. Within 1 week, participants completed a 30-minute bout of submaximal exercise (80% VO 2peak ) on a cycle ergometer. Ratings of quadriceps muscle pain intensity were recorded every minute during the maximal incremental exercise test and every 5 minutes during the submaximal exercise session. Self-efficacy for tolerating pain was moderately inversely correlated with ratings of peak muscle pain during the maximal incremental exercise test ( r = −.45) and pain ratings averaged across the submaximal session ( r = −.49). Our results are consistent with social-cognitive theory and indicate that self-efficacy for tolerating pain is inversely associated with ratings of muscle pain during maximal and submaximal exercise in healthy and regularly active young adult females. Such findings support a possible examination of strategies for manipulating self-efficacy for tolerating pain and thereby reducing muscle pain during exercise. Perspective Our data provided evidence that self-efficacy for tolerating moderate to strong muscle pain during exercise correlates with muscle pain intensity ratings during bouts of maximal and submaximal exercise. Future research could identify methods of manipulating self-efficacy as a means of decreasing muscle pain during exercise and ultimately enhancing physical activity participation.
Numerical experiments on thermal convection in a chemically stratified viscous fluid heated from below: implications for a model of lunar evolution

Abstract Compositional density differences resulting from the initial differentiation or secular evolution of planetary mantles can create buoyancy forces comparable to, or even larger than, those caused by thermal expansion. This study examines two and three-dimensional numerical experiments on thermal convection in a stably stratified, infinite Prandtl number fluid heated from below at a prescribed rate. A thermally and chemically well-mixed convecting layer forms and thickens with time. The layer thickness and temperature as functions of time are determined for a range of thermal and compositional Rayleigh numbers. In some cases a second layer forms above the first, and we examine a criterion for its formation based on the critical Rayleigh number of the conductive thermal boundary layer above the first convecting layer. When a second layer is not present, the thickness of the convecting, well-mixed layer increases approximately as the square-root of time at a rate that depends on the ratio of compositional and thermal buoyancy but which is independent of the thermal Rayleigh number. We show that this thickening rate and the temperature in the mixed layer are well described by a simple physical parameterization that assumes a thermally and compositionally uniform mixed layer and a density at the top of the mixed layer that is the same as that in the immediately overlying, still stably stratified fluid. These results may have a variety of implications for planetary evolution. Here we focus on a model for the evolution of the Moon in which gravitational differentiation of the unstable stratification resulting from solidification of a magma ocean creates a stably stratified mantle with dense, late stage, ilmenite-cumulates forming a U- and Th-rich core which heats the overlying mantle. Compositional stratification in the mantle traps heat in the interior and prevents the rapid formation of plumes capable of generating surface volcanism. Melting at the top of a gradually thickening heated mixed layer in the mantle can explain the age of onset and the depth of origin of the high and low-Ti mare basalts. This may also explain the thick elastic lithosphere and mascon gravity anomalies that developed at the time of mare volcanism. The results of our numerical experiments allow a more rigorous examination of this model of lunar evolution.
Weight loss before gastric bypass: feasibility and effect on postoperative weight loss and weight loss maintenance

Abstract Background This study was performed at a tertiary care university hospital. We hypothesized that weight loss before laparoscopic Roux-en-Y gastric bypass (LRYGB) is feasible, does not diminish the expected postoperative weight loss, and might enhance overall weight loss and maintenance. Methods A population of 351 consecutive patients, who had undergone LRYGB, was divided into 4 groups depending on the percentage of body weight loss achieved before surgery (group 1, none or gain; group 2, 10%). Data were collected regarding the demographics, body mass index (BMI) change, and excess weight loss and analyzed by analysis of variance and Fisher's exact test at the α = 0.05 level. Results All groups were demographically similar in age and were predominantly women. The maximal follow-up was 36 months. Groups 3 and 4 had significantly greater initial excess weight and BMI ( P 5% body weight. Preoperative weight loss did not decrease the magnitude of the expected postoperative weight loss. Patients who lost weight preoperatively demonstrated more excess weight loss and BMI change (from their initial weight) that was sustained far into the postoperative period and reached statistical significance at several points ( P Conclusion The results of this study have demonstrated that obese patients are capable of losing weight before LRYGB and that this weight loss does not negatively affect their expected postoperative weight loss. Furthermore, preoperative weight loss combined with LRYGB might result in better long-term excess weight loss and BMI change than surgery alone.
Continuous Monitoring of Enzyme Reactions on a Microchip: Application to Catalytic RNA Self-Cleavage

Kinetic analysis of RNA enzymes, or ribozymes, typically involves the tedious process of collecting and quenching reaction time points and then fractionating by polyacrylamide gel electrophoresis (PAGE). As a way to automate and simplify this process, continuous analysis of a ribozyme reaction is demonstrated here using completely automated capillary sample introduction onto a microfabricated device with laser-induced fluorescence detection. The method of injection is extremely reproducible thereby standardizing data analysis. A 30-nucleotide ribozyme model, the self-cleaving lead-dependent ribozyme, or "leadzyme", which cleaves into a 24-mer and a 6-mer in the presence of Pb(2+), was end-labeled with fluorescein (FAM) and used to demonstrate the potential of this technique. After manually initiating the cleavage reaction by Pb(2+) addition, reaction samples were automatically injected directly into the parallel separation lanes of the chip via a capillary at predetermined time intervals, thus eliminating the need for additional sample-handling steps. The FAM-labeled leadzyme starting material and products were monitored for 60 min in order to ascertain kinetic information. The effect of lead acetate concentration on cleavage rates was also studied, and the results are in agreement with rates determined by conventional hand-mixing/PAGE analysis. This work demonstrates, through the use of a simple ribozyme model, the potential of this method to provide valuable kinetic information for other, more complex, biologically relevant RNA and protein enzymes.
Metabolic evidence that regional hypothermia induced by cold saline protects the heart during ischemic arrest

Abstract The rationale for cold saline induced hypothermic myocardial protection during ischemic cardioplegia has been limited for the most part to empiric and contractility observations. The aim of this study was to evaluate the degree of metabolic protection afforded by this procedure. In 21 dogs (C) placed on total cardiopulmonary bypass, normothermic ischemic arrest was induced for 60 min followed by 30 min of reperfusion. In 8 other dogs (CS), similarly treated, the heart was continuously cooled with saline at 5°C before and during the ischemia. Myocardial biopsies analyzed for ATP, ADP, creatine phosphate (CP), lactate and glycogen (Gly), were obtained before cross clamping at 15, 30, 45 and 60 min of ischemia and after 30 min of reperfusion. Significantly higher levels of ATP, CP and Gly were found in the CS hearts during and following the cross clamp period. These data indicate that local hypothermia slows the breakdown of high energy phosphate moieties during ischemic arrest. However, despite the protection afforded, ATP remains significantly depressed following reperfusion.
RNase H-dependent PCR (rhPCR): improved specificity and single nucleotide polymorphism detection using blocked cleavable primers

The polymerase chain reaction (PCR) is commonly used to detect the presence of nucleic acid sequences both in research and diagnostic settings. While high specificity is often achieved, biological requirements sometimes necessitate that primers are placed in suboptimal locations which lead to problems with the formation of primer dimers and/or misamplification of homologous sequences. Pyrococcus abyssi (P.a.) RNase H2 was used to enable PCR to be performed using blocked primers containing a single ribonucleotide residue which are activated via cleavage by the enzyme (rhPCR). Cleavage occurs 5'-to the RNA base following primer hybridization to the target DNA. The requirement of the primer to first hybridize with the target sequence to gain activity eliminates the formation of primer-dimers and greatly reduces misamplification of closely related sequences. Mismatches near the scissile linkage decrease the efficiency of cleavage by RNase H2, further increasing the specificity of the assay. When applied to the detection of single nucleotide polymorphisms (SNPs), rhPCR was found to be far more sensitive than standard allele-specific PCR. In general, the best discrimination occurs when the mismatch is placed at the RNA:DNA base pair. rhPCR eliminates the formation of primer dimers and markedly improves the specificity of PCR with respect to off-target amplification. These advantages of the assay should find utility in challenging qPCR applications such as genotyping, high level multiplex assays and rare allele detection.
Ontogeny of ethanol elimination and ethanol-induced hypothermia

Ontogeny of ethanol elimination rates and ethanol-induced hypothermia were examined as possible mechanisms contributing to the marked reduction in ethanol sensitivity early in life (Little et al., 1996; Silveri & Spear, 1998) and the notable gender difference in ethanol sleep-time seen in adult animals (Silveri & Spear, 1998). Elimination rates and brain/blood ethanol levels were determined following doses of 1.5 or 4.5 g/kg ethanol in male and female Sprague-Dawley rats at postnatal days (P)16, 26, 36, or 56. Animals were sacrificed at 40, 80, or 160 min post-injection, with ethanol elimination rates estimated from the slope of the regression of blood and brain alcohol levels across the three sampling periods. P16 animals exhibited the slowest rate of ethanol metabolism, while no gender effects were evident at any age. Observed ontogenetic increases in ethanol hypothermia were not systematically related to the ontogeny of ethanol metabolism. Factors other than ontogenetic changes in ethanol metabolism, hypothermia, or the distribution of ethanol between brain and blood must underlie the relative insensitivity to ethanol often reported in young and adolescent organisms, a fruitful area for future studies given the frequent use and misuse of alcohol by human adolescents.
Thermal properties measurements of solid rocket propellant oxidizers and binder materials as a function of temperature

Abstract Using a fairly simple technique and small samples it was possible to obtain thermal diffusivity, specific heat capacity, and thermal conductivity, all as a function of sample temperature, for a variety of ingredients used in solid rocket propellants. The oxidizers AP, ADN, CL20, HMX, RDX, HNF, TNAZ were studied as well as the nonenergetic polymers TeflonTM, HTPB, and polyurethane, energetic binders containing GAP and BAMO and/or NMMO, and actual solid propellants XM39, N5, N12, and SB129.
Cohomology of the Double Cover of the Mathieu Group M12

Abstract In this paper we calculate the mod two cohomology of the double cover of the Mathieu group M 12 . The starting point is the calculation by Adem, Maginnis and Milgram of the mod two cohomology of M 12 . We use a hypercohomology spectral sequence to determine a differential in the Lyndon-Hochschild-Serre spectral sequence of the central extension, and this gets us as far as the E ∞ page. Ungrading requires restriction to the Sylow 2-subgroup, and here some computer calculations come to our rescue.
METROPOLITAN DECONCENTRATION: SUBAREAL IN- MIGRATION AND CENTRAL CITY TO RING MOBILITY PATTERNS AMONG SOUTHERN SMSAs

The analysis of in-migration streams and subareal residential mobility patterns for moves made between 1965 and 1970 in SMSAs in the East South Central and South Atlantic census divisions indicates that, despite their historical contexts, these metropolitan areas now show spatial differentiation patterns similar to those of the great cities of the Northeast. The white population has increased in ring areas primarily because of in-migration rates; the black population in the central cities has increased primarily because of in-migration rates to those subareas. Little variation in these patterns across SMSA size categories was apparent.
Radiative energy loss from hot C60 molecules

Abstract Radiative energy-loss rates from isolated molecules of C60 are examined by using both measured oscillator strengths and modified black-body models. At energies where radiative cooling might compete with dissociation, we find that vibrational emission is negligible in comparison with the dominant electronic emission. We also find that a black-body model in its usual form greatly overestimates the radiative energy-loss rate. When more completely implemented, it draws upon precisely the same information and becomes identical with an oscillator treatment, and so has no contribution to make in estimating radiative energy losses.
Electronic Texts in ESOL Classrooms.

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China in the Russian mind today: Ambivalence and defeatism

Abstract This article describes the ambivalence of Russian attitudes toward China at the beginning of the twenty-first century. Russians of all strata combine a willingness to see China as a friendly neighbour with a high level of fear of the giant that could swallow much of the country whole, especially the Asian part. The article pays special attention to the split in Russian views of China among elites. While some elites, who have strong anti-American attitudes, see China as a major ally against the United States, others call on the government to treat the United States as the single force that can help Russia protect the integrity of its territory against China, whose people still do not recognise the existing borders between the two countries.
Introducing the No Preventable Harms campaign: Creating the safest health care system in the world, starting with catheter-associated urinary tract infection prevention

Background Endemic health care-associated safety problems, including health care-associated infection, account for substantial morbidity and mortality. We outline a regional No Preventable Harms campaign to reduce these safety problems and describe the initial results from the first initiative focusing on catheter-associated urinary tract infection (CAUTI) prevention. Methods We formed a think tank composed of multidisciplinary experts from within a 7-hospital Midwestern Veterans Affairs network to identify hospital-acquired conditions that had strong evidence on how to prevent the harm and outcome data that could be easily collected to evaluate improvement efforts. The first initiative of this campaign focused on CAUTI prevention. Quantitative data on CAUTI rates and qualitative data from site visit interviews were used to evaluate the initiative. Results Quantitative data showed a significant reduction in CAUTI rates per 1,000 catheter days for nonintensive care units across the region (2.4 preinitiative and 0.8 postinitiative; P = .001), but no improvement in the intensive care unit rate (1.4 preinitiative and 2.1 postinitiative; P = .16). Themes that emerged from our qualitative data highlight the need for considering local context and the importance of communication when developing and implementing regional initiatives. Conclusions A regional collaborative can be a valuable strategy for addressing important endemic patient safety problems.
Beliefs About Causes of Schizophrenia Among Urban African American Community Members

The public’s causal attributions of schizophrenia have far-reaching effects on the community and affected individuals. This study investigated causal beliefs within a community of predominantly Protestant, low-income, urban, African Americans in the southeastern United States. Two hundred eighty-two patrons of an inner-city food court/farmers’ market participated in a self-administered survey assessing causal beliefs through a 30-item survey and self-reported causal opinions. Associations were assessed between causal attributions of schizophrenia and sociodemographic characteristics and exposure/familiarity variables. Certain sociodemographic variables, as well as key exposure/familiarity variables, predicted the nature of one’s causal beliefs. The most common causal opinions reported included substance abuse, negative life events, and “mental illness.” Findings from a subsample administered an exploratory multiple-choice question investigating understanding of causation revealed that the public may not fully understand the nature of causation. Although this study suggests potential determinants of causal beliefs held by community members, further research examining the public’s conception of causation would enhance interpretation of studies on such beliefs.
Investigation of the State of Water in Hydrating Layered Sodium Disilicate in Crystalline and Amorphous Forms by Quasi-Elastic Neutron Scattering

The structure and state of water within hydrating crystalline and amorphous sodium disilicate were monitored for the first time using quasi-elastic neutron scattering (QENS) and X-ray diffraction (XRD). The QENS kinetic data collected for the first 12 h of the reaction were fitted to a model consisting of a Lorentzian and a Gaussian function each convoluted with the energy resolution of the instrument. This allowed the QENS signal from water to be associated with two states that included bound and free water, as confirmed by thermogravimetric analyses and 2H NMR. In situ QENS data were collected for a set of sodium disilicate and silica mixtures at a series of discrete temperatures between 20 and 40 °C. The bound water was successfully modeled with first-order reaction kinetics to quantify the hydration of the layered silicate structure within kanemite. First-order reaction kinetics was also used to model the reaction using amorphous starting material, which may also suggest the presence of hydrated layer...
Higher-spin cluster algorithms: the Heisenberg spin and U(1) quantum link models

Abstract I discuss here how the highly-efficient spin - 1 2 cluster algorithm for the Heisenberg antiferromagnet may be extended to higher-dimensional representations; some numerical results are provided. The same extensions can be used for the U (1) flux cluster algorithm, but have not yielded signals of the desired Coulomb phase of the system.
Specialized cilia of the byssus attachment plaque forming region in Mytilus californianus

The distal depression of the ventral pedal groove of Mytilus californianus was investigated by scanning and transmission electron microscopy. This part of the byssus forming system is responsible for the formation of the attachment plaque of the byssus thread. The longitudinal pedal ducts open into this area and the floor of the distal depression is covered by specialized cilia which terminate as biconcave flattened discs or “paddles.” The disc is formed by a 360° curvature of the axoneme tip within the ciliary membrane. The diameter of the disc is about 1.33 μ while that of the shaft portion is 0.24 μ. There are about 11 cilia per square micron of surface area and the necks of the cilia are separated from each other by a web-like extension of apical cytoplasm extending from the epithelial cells. It is proposed that these specialized cilia function as microscopic spatulas for the application of the adhesive plaque material to substrate surfaces. The pattern of surface convection currents seen in vivo tends to support this hypothesis.
Application of high affinity binding concept to radiolabel avidin with Tc-99m labeled biotin and the effect of pI on biodistribution

In order to label avidin with Tc-99m, we took advantage of the high affinity binding of biotin to avidin; we radiolabeled a biotin derivative with Tc-99m and then bound this Tc-99m labeled biotin derivative to avidin. For our labeling approach, N epsilon-biotinyl-L-lysine (Biocytin) was reacted with the N-hydroxy-succinimide ester of benzoylmercaptoacetyltriglycine (Bz-MAG3). The resulting Bz-MAG3-Biocytin was labeled with Tc-99m using Tc-99m glucarate as a Tc-99m transchelating agent and mixed with avidin at a 1:1 molar ratio resulting in almost a quantitative labeling yield. Tc-99m-MAG3-Biocytin/Avidin was stable in serum at 37 degrees C with 97 and 95% of the total Tc-99m activity still bound to avidin at 2 and 24 h, respectively. The biodistribution of Tc-99m-MAG3-Biocytin/Avidin in normal Balb/c mice showed a high liver and kidney uptake with 56.6 and 28.9%, respectively at 10 min. We attempted to lower the liver and the kidney activities by reducing the isoelectric point (pI) of avidin by conjugating succinic acid moieties at lysine residues of avidin (pI 10). The kidney uptake decreased to 19.0, 3.1 and 1.7% when the pI of avidin was reduced to 7.0-9.3, 5.5-6.2 and 4.0-4.8, respectively. The lowering of the pI, however, did not change the liver activity appreciably.
Pothole and channel system formation in the McMurdo Dry Valleys of Antarctica: New insights from cosmogenic nuclides

Large pothole and channel features (� 15 m deep, � 30 m wide) carved into the Beacon Sandstone in the upland Dry Valleys of Antarctica have been used to infer catastrophic subglacial flooding beneath an expanded East Antarctic Ice Sheet that overran the Transantarctic Mountains during the mid-Miocene. Though the age and erosion rates of these geomorphic features have not been quantified, preservation of the potholes and channels has been attributed to negligible erosion under consistent polar desert conditions since the retreat of the ice sheet at � 14 Ma. We present cosmogenic 21 Ne and 10 Be data