cssi/SciSciGPT-SciSciNet huggingface dataset:
Model and Algorithm of Online Risk Assessment on Urban Power System

This paper describes a practical method of Online Risk Assessment (ORA) on urban power system. It includes a set of models for online risk analysis of urban power system, the Online Probabilistic Risk Indices (OPRI) & their arithmetic, and the models for computing parameters varying with operating conditions which are used for Probabilistic Risk Indices calculation. The ability of the method can provide operators in control center the near term identification on security level, weak point, and riskiest event of urban power system. Further more, the system architecture of Online Risk Assessment (ORA) is presented, which is the preparation of software implementation of Online Risk Assessment System (ORAS) on Urban Power System
Luminosity and propagation characteristics of sprite streamers initiated from small ionospheric disturbances at subbreakdown conditions

[1] This paper reports a modeling study on sprite streamer formation at subbreakdown conditions, i.e., the initiation of sprite streamers in a lightning field below the breakdown threshold field Ek. Successful formation of streamers is observed for a variety of electric fields with the lowest field of 0.3Ekwhen an appropriate ionization column is introduced. The simulation results also indicate that the initial ionization patch from which a streamer is initiated may become very bright following the streamer formation, and its brightness persists as the streamer continues its propagation. The overall luminous structure of the streamer and the ionization patch is very similar to the appearance of initiation of a single sprite streamer on high-speed images. The brightness of the patch depends on its initial density, and the patch with smaller density is brighter than the denser one. An analytical formula describing the temporal and spatial variation of the electric field in the streamer channel is derived to explain the brightening of the ionization column as well as the luminous streamer trail. Finally, comparisons between the streamers from the ionization patch and those forming in the vicinity of a conducting sphere in an electric field belowEk show that the exponential growth rates associated with streamer characteristics are similar.
Spatial resolution and nature of defects produced by low‐energy proton irradiation of GaAs solar cells

AlGaAs/GaAs solar cells with about 0.5-micron-thick Al(0.85)Ga(0.15)As window layers were irradiated using isotropic and normal incidence protons having energies between 50 and 500 keV with fluences up to 1 x 10 to the 12th protons/sq cm. Although the projected range for these protons varies from 0 to more than 4.5 microns, the recombination losses due to the irradiation-induced defects were observed to be maximum in the vicinity of the AlGaAs/GaAs interface and the space-charge region irrespective of the proton energy. This was found by analyzing spectral response measurements. The results are explained by using a model in which the interaction of as-grown dislocations with irradiation-induced point defects is considered.
Structured interaction in game theory

Over the last several years, a number of authors have developed graphtheoretic or network models for large-population game theory. In such models, each player or organization is represented by a vertex in a graph, and payoffs are determined by the actions of only those in the neighborhood of a player. This allows the detailed specification of social, organizational, biological and other types of structure in the strategic interaction of the population.In this talk, I will survey these models and the attendant algorithms for certain basic computations, including Nash and correlated equilibria. Generalizations to macroeconomic models will be discussed, as well as potential connections to social network theory and the emerging field of neuroeconomics.
Interannual variability of low-degree gravitational change, 1980–2002

Time variations in the Earth's gravity field at periods longer than 1 year, for degree-two spherical harmonics, DC21, DS21, and DC20, are estimated from accurately measured Earth rotational variations. These are compared with predictions of atmospheric, oceanic, and hydrologic models, and with independent satellite laser ranging (SLR) results. There is remarkably good agreement between Earth rotation and model predic- tions of DC21 and DS21 over a 22-year period. After decadal signals are removed, Earth-rotation-derived interannual DC20 variations are dominated by a strong oscillation of period about 5.6 years, probably due to uncertainties in wind and ocean current estimates. The model-predicted DC20 agrees reasonably well with SLR observations during the 22-year period, with the excep- tion of the recent anomaly since 1997/1998.
A large daylight geodesic dome for quantification of whole-ecosystem CO2 and water vapour fluxes in arid shrublands

Abstract We designed, constructed, calibrated and field-tested a lightweight (30 kg), 4.2 m diameter, 16.4 m 3 polyethylene-covered dome static chamber ecosystem gas exchange cuvette that can quantify ecosystem CO 2 and water vapour fluxes as low as 0.1 μmol CO 2 m −2 s −1 and 0.1 mmol H 2 O m −2 s −1 with little impact on environmental conditions. Fluxes measured in May 2001 in an intact Great Basin sagebrush ecosystem at midday were significantly higher than in an adjacent post-wildfire successional ecosystem, with observed ranges from –0.71 to 1.49 μmol CO 2 m −2 s −1 for CO 2 and from –0.09 to 0.53 mmol H 2 O m −2 s −1 for water vapour.
Chromate ion-exchange process at alkaline pH

Abstract The chromate ion-exchange recovery process is always carried out at acidic pH because of its much higher chromate removal capacity at acidic pH as opposed to alkaline pH. However, acidic pH operation always gives rise to early, gradual chromate breakthrough during conventional fixed-bed column runs. Possibility of alkaline pH operation, which gives self-sharpening type chromate breakthrough during column runs, has been studied in detail. A new polystyrene matrix resin with relatively high degree of crosslinking was found to have high chromate selectivity at alkaline pH. This enhanced chromate selectivity is due to the resin's increased hydrophobicity. Particularly at low ionic strength of cooling water, alkaline pH operation with this new resin may offer higher chromate selectivity compared to conventional acidic pH operation.
Isolation and description ofHaloanaerobium praevalens gen. nov. and sp. nov., an obligately anaerobic halophile common to Great Salt Lake sediments

A new halophilic species is described that was isolated from the hypersaline (>20%) surface sediments of Great Salt Lake, Utah, via transfer from MPN end-dilution tubes that contained a complex organic medium. The organism was an obligate anaerobe that proliferated optimally at approximately 13% salt, but did not grow significantly at 5°C and <60°C, the pH range was between 6.0 and 9.0. The doubling time for growth in complex medium with 25% NaCl was 7 h. The organism utilized carbohydrates, peptides, and amino acids. Butyrate, acetate, propionate. H2, and CO2 were the major fermentation end products formed. Glucose, mannose, fructose,n-acetyl glucosamine, and pectin were used as energy sources for growth. Methylmercaptan was produced from methionine degradation. The nameHaloanaerobium praevalens gen. nov. sp. nov. is proposed for the type strain GSL which has been deposited as DSM 2228. The taxonomic relationships ofH. praevalens to other obligate halophiles and anaerobes, as well as its biological role in the Great Salt Lake microbial ecosystem, are discussed.
Burnout in United States Academic Chairs of Radiation Oncology Programs

Purpose The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. Methods and Materials An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Results Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. Conclusions This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members.
Gonadotropin stimulation of steroidogenesis and cellular dispersion in cultured porcine cumuli oophori

The relationship between cellular dispersion and steroidogenesis was studied in culture using oocyte-cumulus complexes harvested from porcine follicles. The cells were cultured in modified TC 199 containing pig serum for one to two days. When oocyte-cumulus complexes were cultured in the absence of hormone the oocytes resumed meiosis, the cumulus cells grew out forming monolayers, and progesterone accumulation was low. Addition of ovine LH, purified human LH, or purified human FSH stimulated expansion of the cumulus mass as well as enhanced progesterone accumulation. Oocyte maturation was not affected by the hormones. In absence of hormone, oocyte-cumulus complexes obtained from large (6–12 mm) follicles showed increased cellular dispersion and higher progesterone accumulation as compared to complexes obtained from medium-sized (3–5 mm) follicles.
DESTRUCTION OF MICROORGANISMS AND DEFORMATION OF PLASTIC JARS BY HOT SORGHUM SYRUP

Sweet sorghum syrup was heated at 49° to 71°C and filled into glass jars of 200 mL capacity that contained each of four microorganisms (Bacillus subtilis; Byssochlamys nivea; Saccharomyces rouxii; and Aspergillus niger) at 0, 1,000 or 10,000 CFU/mL syrup. Counts were determined on syrup immediately after filling into the jars and after four months storage. The heated syrup at all temperatures significantly reduced the survival of bacteria and fungi at the time of filling. After four months, no bacteria could be detected in syrup at each temperature, and no fungi could be detected at 66° and 71°C. The heat of syrup at 71°C or lower did not cause single layer polypropylene jars to become deformed; however, at 77° and 82°C deformation occurred such that the jars were unsatisfactory for the packaging of syrup. Therefore, syrup can be filled at 66° and 71° into single layer polypropylene jars. At these temperatures, common spoilage microflora were destroyed or inactivated during storage, and the plastic jars did not become deformed.
Effects of Corneal Nerve Density on the Response to Treatment in Dry Eye Disease

Purpose To evaluate whether levels of corneal subbasal nerve fiber length (SNFL) in dry eye disease (DED) could prognosticate the level of improvement in signs and symptoms after treatment. Design Phase IV, double-masked, randomized clinical trial. Participants Sixty patients with meibomian gland dysfunction–associated DED and 27 age-matched controls. Methods Patients with DED were randomized to receive topical artificial tears, loteprednol etabonate 0.5%, or loteprednol etabonate 0.5%/tobramycin 0.3% twice daily for 4 weeks. At baseline, in vivo confocal microscopy of central cornea was performed in both eyes. Patients with DED were divided into 2 subgroups: those with low baseline SNFL and those with near-normal baseline SNFL for this purpose (the cutoff point: the mean SNFL in controls minus 2 standard deviations). Clinical signs and symptoms at baseline and after 4 weeks of treatment were compared between the subgroups with low and near-normal SNFL for all therapeutic groups. Main Outcome Measures Symptom questionnaires, corneal fluorescein staining (CFS), conjunctival staining with lissamine green, tear break-up time, Schirmer's test, and SNFL. Results In patients with DED, baseline SNFL (17.06±5.78 mm/mm 2 ) was significantly lower than in controls (23.68±3.42 mm/mm 2 , P = 0.001). In the artificial tear and loteprednol groups, although no significant improvement in any sign or symptom was noted in patients with low baseline SNFL ( 2 ), subjects with near-normal baseline SNFL (≥16.84 mm/mm 2 ) showed significant improvement in both symptoms and CFS score (all P Conclusions Significant improvements in CFS and patient symptomatology after DED treatment were evident only in the subgroup with near-normal corneal SNFL. Consideration of SNFL may assist in explaining the variability of patients' response to DED therapy.
Homelessness as the Unforgiving Minute of the Present: The Rhetorical Tenses of Democratic Citizenship

Popular discourse and advocacy efforts characterize homelessness as a social problem bound by the present-centered concerns of physical affliction and material deprivation. Wayne Powers's documentary film Reversal of Fortune exemplifies this tendency by performing a “social experiment” to investigate how giving a homeless man $100,000 would change his life: the film chronicles the intervention in terms of an ever-fleeting opportunity that the man ultimately fails to utilize. Such discourses deny the future-oriented grounds for identification between homeless and housed as citizens sharing a common political destiny. Discourses of homelessness thus provide an important opportunity for questioning how the rhetorical tenses of democratic citizenship can be cultivated or suppressed, and how such rhetorical work can contribute to a more dynamic democratic culture.
A formulation for higher dimensional inverse problems for the wave equation

Abstract Two particular inverse scattering problems are of special interest. The first concerns the discovery of a perturbation in the speed of sound by analyzing the return signal from a blast wave set off above it. The second concerns the determination of a potential from the back scattering of plane waves. In one dimensional problems the two cases are very closely related. In higher dimensions the situation becomes much more complicated. We present here a new approach to four such classical higher dimensional inverse problems for determining the coefficients of a partial differential equation, including the two mentioned. The idea stems from the work of Deift and Trubowitz [1], in one space dimension. No conclusive theorem is found but the approach provides an algorithm for iteration which might lead to an existence theorem and which will be explored numerically elsewhere.
The Intravenous Anesthetic Propofol Inhibits Human L-Type Calcium Channels by Enhancing Voltage-Dependent Inactivation

Propofol is commonly used to induce anesthesia but has been associated with some negative cardiovascular side effects, including negative inotropy, hypotension, and bradycardia. This study investigated the effect of propofol on L-type calcium current in acutely isolated human atrial myocytes to better understand the mechanism of these side effects. After informed consent was obtained, the atrial appendage was obtained from patients undergoing open-heart surgery who required cardiopulmonary bypass. Atrial myocytes were isolated using enzymatic digestion, and L-type calcium currents were recorded using the whole-cell patch clamp technique. Propofol enhanced the magnitude and speed of voltage-dependent inactivation of L-current. As a result, the propofol-induced inhibition was increased by protocols that increased inactivation such as longer voltage step duration, holding potential depolarization, and increased pulsing frequency. The preferential enhancement of L-channel inactivation by propofol can explain the associated cardiovascular side effects. The depolarized resting potential of arterial smooth muscle may render the L-channels in these cells particularly sensitive to propofol-induced inhibition, which could explain the hypotension observed in some patients. The enhancement of both inactivation kinetics and steady-state inactivation by propofol can also explain the negative inotropic effect. However, the enhanced voltage-dependent inactivation and use dependence could have beneficial effects for patients prone to certain arrhythmias and tachycardia.
Promoting Informed Choice of Unsedated Colonoscopy: Patient-Centered Care for a Subgroup of U.S. Veterans

Background In the United States, colonoscopy is usually performed under sedation. In practice, 2.3–7% actually requested unsedated colonoscopy and 1.4% received it because of no escorts. Efforts to increase usage would likely require increased patient counseling and education. Aim We tested the hypothesis that knowledge conveyed by education—a key attribute of patient-centered care—is associated with acceptance of the “non-usual” option. Methods After patients underwent discussions and expressed acceptance of sedated colonoscopy, the pros and cons of and local experience with unsedated colonoscopy were added. The patients who changed from accepting sedated to unsedated colonoscopy and outcomes of their examinations were recorded. Results From January to November 2006, 49 of 176 consecutive patients (28%) changed their choice from sedated to unsedated colonoscopy after being informed of the latter. Forty-eight had satisfactory bowel preparation. Cecal intubation rate was 93.7% (45 of 48). Thirty-six reported good experience and 43, likely to repeat. Cecal intubation, withdrawal, and discharge times were 23.0 ± 1.4 min, 15.0 ± 1.0 min, and 5.0 ± 0.5 min, respectively (n = 45). Ability to communicate with the colonoscopist during and after the examination was the most frequently ranked reason for choosing unsedated colonoscopy. Conclusion Our uncontrolled, non-randomized, single-site observational data revealed that for selected veterans, acceptance of unsedated colonoscopy coincides with knowledge of the option dispensed by patient counseling and education.
Effect of atropine on the onset of fear bradycardia in Eastern cottontail rabbits Sylvilagus floridanus.

Abstract 1. Biotelemetry transmitters were surgically implanted in the abdominal cavity of six mature eastern cottontail rabbits, Sylvilagus floridanus , and the effect of atropine on the rate of onset of fear bradycardia investigated. 2. Electrocardiogram records were obtained from demodulation of magnetically recorded data on a physiograph. Instantaneous heart rate was obtained and averaged for each second. Ten seconds of pre-stimulus data was obtained, followed by thirty seconds of data obtained while frightening the rabbit. 3. A marked fear bradycardia was present in all untreated and atropine-treated animals. 4. Mean heart rate values for untreated rabbits were 195 ± 2.9 and 125 ± 2.1 ( x ± SE ) bpm during pre-stimulus and stimulus respectively. 5. Mean values for atropine-treated animals were 241 ± 1.1 and 162 ± 5.0 bpm during prestimulus and stimulus respectively. 6. Atropine reduced fear bradycardia from 36.1% to 33.8%, but reduced the rate of onset from −9.25 to −3.14 bpm/sec. 7. Fear bradycardia can occur without parasympathetic activity, but parasympathetic activity is necessary for the normal rapid onset of fear bradycardia.
SU‐E‐T‐126: Analysis of Uncertainties for the RPC Remote Dosimetry Using Optically Stimulated Light Dosimetry (OSDL)

Purpose: Determine the uncertainty of the Radiological Physics Center's (RPC) remote audit dose measurement of photon and electron beam outputs using Optically Stimulated LuminescenceDosimeters (OSLD). Methods: In June 2010 the RPC implemented a switch from TLD to an OSLD mailed dosimetry audit using Landauer's InLight nanoDot™ OSLdosimeters and microStar reader System™. The steps and factors for the calculation of dose with OSLD were designed to follow those already in use with TLD including the use of the same acrylic mini‐phantoms and irradiation instructions. The OSLD sensitivity was referenced to Co‐60, and corrections for linearity, individual dosimeter response, fading, use of mini‐phantoms and energy were determined for the OSLD. An analysis of the uncertainty of each of the correction factors was determined to give an overall uncertainty of the OSLD dose measurement under Co‐60 reference conditions and megavoltage beam audits. Results: The expectation was that with the physical processes for OSLD, being so closely resembling those of TLD, the uncertainties of OSLD would be comparable to those of TLD. A combined uncertainty of 0.8% for irradiations with Co‐60 under controlled reference conditions and 1.8% for irradiations with high‐energy X‐rays was determined as compared to 1% and 2% for the previously used TLD, respectively. The OSLD energy block correction factor (KE) is the primary source of the overall OSLD dose measurement uncertainty. To date, the OSLD audit results after a year are essentially identical to the previous 5 years of TLD results both showing a mean TLD/Inst. Ratio of 1.00 ± 0.018.Conclusion: The uncertainty of the RPC's new OSLD remote dosimetry audit program's dose measurement is equal to if not less than that for the historical TLD program. Work supported by PHS CA010953, awarded by NCI, DHHS.
An accountability model for counselors

A sound counselor accountability system would collate counselor accomplishments with costs. Better decisions could then be made about effective methods, staffing, student needs, and training. The system would define the domain of counselor responsibilities, use student behavior changes as evidence of counselor accomplishments, state counselor activities as costs, promote self-improvement, permit reports of failures and unknown outcomes, be designed by users, and be subject to revision. An illustrative accountability report shows how the cost, but not the value, of an outcome can be estimated. Experimentation is needed in order to answer the practical implementation problems of the system.
ERK1/2-p90RSK-mediated phosphorylation of Na+/H+ exchanger isoform 1. A role in ischemic neuronal death.

The function and regulation of Na+/H+ exchanger isoform 1 (NHE1) following cerebral ischemia are not well understood. In this study, we demonstrate that extracellular signal-related kinases (ERK1/2) play a role in stimulation of neuronal NHE1 following in vitro ischemia. NHE1 activity was significantly increased during 10-60 min reoxygenation (REOX) after 2-h oxygen and glucose deprivation (OGD). OGD/REOX not only increased the Vmax for NHE1 but also shifted the Km toward decreased [H+]i. These changes in NHE1 kinetics were absent when MAPK/ERK kinase (MEK) was inhibited by the MEK inhibitor U0126. There were no changes in the levels of phosphorylated ERK1/2 (p-ERK1/2) after 2 h OGD. The p-ERK1/2 level was significantly increased during 10-60 min REOX, which was accompanied by nuclear translocation. U0126 abolished REOX-induced elevation and translocation of p-ERK1/2. We further examined the ERK/90-kDa ribosomal S6 kinase (p90RSK) signaling pathways. At 10 min REOX, phosphorylated NHE1 was increased with a concurrent elevation of phosphorylation of p90RSK, a known NHE1 kinase. Inhibition of MEK activity with U0126 abolished phosphorylation of both NHE1 and p90RSK. Moreover, neuroprotection was observed with U0126 or genetic ablation or pharmacological inhibition of NHE1 following OGD/REOX. Taken together, these results suggest that activation of ERK1/2-p90RSK pathways following in vitro ischemia phosphorylates NHE1 and increases its activity, which subsequently contributes to neuronal damage.
Influence of earthworm activity on aggregate-associated carbon and nitrogen dynamics differs with agroecosystem management

Abstract Earthworms are known to be important regulators of soil structure and soil organic matter (SOM) dynamics, however, quantifying their influence on carbon (C) and nitrogen (N) stabilization in agroecosystems remains a pertinent task. We manipulated population densities of the earthworm Aporrectodea rosea in three maize-tomato cropping systems [conventional (i.e., mineral fertilizer), organic (i.e., composted manure and legume cover crop), and an intermediate low-input system (i.e., alternating years of legume cover crop and mineral fertilizer)] to examine their influence on C and N incorporation into soil aggregates. Two treatments, no-earthworm versus the addition of five A. rosea adults, were established in paired microcosms using electro-shocking. A 13 C and 15 N labeled cover crop was incorporated into the soil of the organic and low-input systems, while 15 N mineral fertilizer was applied in the conventional system. Soil samples were collected during the growing season and wet-sieved to obtain three aggregate size classes: macroaggregates (>250 μm), microaggregates (53–250 μm) and silt and clay fraction ( 13 C, total N and 15 N were measured for all fractions and the bulk soil. Significant earthworm influences were restricted to the low-input and conventional systems on the final sampling date. In the low-input system, earthworms increased the incorporation of new C into microaggregates within macroaggregates by 35% (2.8 g m −2 increase; P =0.03), compared to the no-earthworm treatment. Within this same cropping system, earthworms increased new N in the cPOM and the silt and clay fractions within macroaggregates, by 49% (0.21 g m −2 ; P −2 ; P =0.02), respectively. In the conventional system, earthworms appeared to decrease the incorporation of new N into free microaggregates and macroaggregates by 49% (1.38 g m −2 ; P =0.04) and 41% (0.51 g m −2 ; P =0.057), respectively. These results indicate that earthworms can play an important role in C and N dynamics and that agroecosystem management greatly influences the magnitude and direction of their effect.
Non-mean-field behavior of realistic spin glasses.

We provide rigorous proofs which show that the main features of the Parisi solution of the Sherrington-Kirkpatrick spin glass, as applied to more realistic spin glass models, are not valid in any dimension and at any temperature. {copyright} {ital 1996 The American Physical Society.}
Hydrogen oxidation activity in membranes from Rhizobium japonicum

Abstract Membranes capable of oxidizing H 2 with O 2 as terminal acceptor were obtained from free-living Rhizobium japonicum . Membranes contained highest H 2 -uptake specific activities when isolated in the presence of an H 2 atmosphere, and when the oxygen radical scavenger butylated hydroxytoluene was included in the buffer used for rupturing cells. After breaking cells, all of the O 2 -dependent H 2 -uptake activity was associated with a particulate membrane-containing fraction, whereas approx. 75% of the methylene blue-dependent H 2 -uptake activity was sedimented. The particulate and soluble fractions containing H 2 -uptake activity with methylene blue were separated by sucrose gradient centrifugation. The particulate and soluble activities behaved identically with regard to artificial electron acceptor specificity and reversible inhibition by oxygen. The hydrogenase in membranes coupled H 2 uptake with the reduction of many positive potential electron acceptors, but not with negative potential acceptors. The optimal pH for H 2 uptake with O 2 as acceptor in membranes was approx. 7.2. H 2 -uptake activity in membranes was associated with an inner (lighter) membrane fraction that also contained succinate oxidase activity. H 2 -reduced minus O 2 -oxidized difference spectroscopy of membranes indicated the involvement of b and c -type cytochromes in the H 2 -oxidation pathway, with an absorption peak at 551.5 nm and a shoulder at 560 nm. The addition of sodium dithionite to H 2 -reduced membranes caused additional b -type cytochrome reduction. The methylene blue-dependent H 2 -uptake activity in membranes was reversibly inhibited by brief exposure to oxygen. Recovery of full activity after oxygen exposure was achieved only after several minutes of incubation under strict anaerobic conditions.
Investigation of substituent effects on the redox properties and oxygen binding of several metalloporphyrins

Abstract Studies of substituent effects on the redox reactions of synthetic metalloporphyrin complexes, such as those described in this paper, are an essential first step in understanding function-property-structure relationships in the biologically important cobalt and iron metalloporphyrins. Furthermore, since HAMMETT linear free energy relationships have been shown to be sensitive to the solvent media, care must be taken in directly comparing physical measurements obtained under different experimental conditions in different solvents.
Complexes of Cu(I) supported by a tris(ketimine) tripod

Arylation of tris(2-benzylnitrile)amine with PhLi, followed by aqueous work-up, results in the formation of a tripodal tris(ketimine) scaffold, N(ArCNHPh)3. N(ArCNHPh)3 readily coordinates a number of CuI salts, generating complexes that exhibit trigonal pyramidal geometries in the solid-state.
High-speed optical coherence tomography for management after laser in situ keratomileusis

Purpose To report applications of optical coherence tomography (OCT) in the management of laser in situ keratomileusis (LASIK) related problems. Setting Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA. Methods Five patients referred for LASIK-related problems were enrolled in a prospective observational study. Clinical examination, ultrasound (US) pachymetry, Placido ring slit-scanning corneal topography (Orbscan II, Bausch & Lomb), and high-speed corneal OCT were performed. Results In cases of regression and keratectasia, OCT provided thickness measurements of the cornea, flap, and posterior stromal bed. Locations of tissue loss and flap interface planes were identified in a case with a recut enhancement complication. The information was used to determine whether further laser ablation was safe, confirm keratectasia, and manage complications. Optical coherence tomography measurements of central corneal thickness agreed well with US pachymetry measurements (difference 6.4 μm ± 11.7 [SD]) ( P = .026), while Orbscan significantly underestimated corneal thickness (−67.5 ± 72.5 μm) ( P = .17). Conclusions High-speed OCT provided noncontact imaging and measurement of LASIK anatomy. It was useful in monitoring LASIK results and evaluating complications.
Concentration of cultured medium to detect small amounts of lymphotoxin induced by PHA, PPD, and thyroid antigens☆

Abstract An effective method for the concentration of cultured medium to detect small amounts of lymphotoxin is described. A microassay for cytotoxicity modified from the method of Takasugi and Klein has been performed using L cells (mouse fibroblast subline 5b) as nonspecific target cell. Activated human lymphocytes produce lymphotoxin in serum-free media, but activity is low compared to culture in media with higher serum concentrations. Human lymphotoxin is stable for three weeks at 3 °C, and no loss of activity is observed after dialysis or lyophilization. Some nonlymphotoxin protein is removable during dialysis. A “concentration assay” of human lymphotoxin and human lymphotoxin-like activity induced by purified protein derivative was performed using lymphocytes cultured in medium containing 2% serum. This method markedly increased the sensitivity of the microassay for lymphotoxin induced by phytohemagglutinin and purified protein derivative. Lymphocyte-mediated cytotoxicity induced by thyroid antigen(s) in patients with chronic thyroiditis was observed. After concentration of supernatants, significant cytotoxic activity was obtained in patients, but not in normal subjects. Lymphocytemediated cytotoxicity, presumably mediated by soluble human lymphotoxin-like cytotoxic factor, may play an importan role in human autoimmune thyroiditis.
Body image, body satisfaction, and unsafe anal intercourse among men who have sex with men.

Using survey results from the 1998 Twin Cities Lesbian, Gay, Bisexual, and Transgender (LGBT) Pride Festival (N = 535), we explored associations between body image and unsafe anal intercourse (UAI) among men who have sex with men (MSM), and evaluated whether body satisfaction mediated this association. MSM who reported underweight body image had lower odds than those who reported average weight of UAI (AOR = 0.33; 95% CI = 0.13, 0.85); body satisfaction was not found to mediate this association. 13.3% of men who reported overweight/obese body image had engaged in UAI compared with 21.6% of those who reported average weight and 8.2% of those who reported underweight (p < .05). Compared with MSM in exclusive relationships, MSM in non exclusive relationships had increased odds of UAI (AOR = 5.78; 95% CI = 2.96, 11.29) as did men who were not partnered (AOR = 3.20; 95% CI = 1.72, 5.93). These findings highlight the importance of including body image in sexual behavior models of MSM to better understand body i...
Retinal degeneration from oxidative damage.

Paraquat, a herbicide that generates reactive oxygen species, has been used to probe the oxidative defense systems of lung. In this study, we investigated the effects of paraquat in the retina. There was no significant decline in electroretinogram (ERG) a- or b-wave amplitudes after intravitreous injection of 1 μl of 0.5 mM paraquat in C57BL/6 mice, but loss of ERG function occurred after injection of 0.75 or 1 mM paraquat. Histology in paraquat-injected eyes showed condensation of chromatin and thinning of the inner and outer nuclear layers indicating cell death, and terminal deoxynucleotidyl transferase-mediated duTP-biotinide end labeling demonstrated that one mechanism of cell death was apoptosis. Fluorescence in the retina and retinal pigmented epithelium after intraocular injection of paraquat followed by perfusion with hydroethidine indicated high levels of superoxide radicals, and oxidative damage was demonstrated by staining for acrolein and enzyme-linked immunosorbent assay for carbonyl adducts. Paraquat-induced damage to the outer nuclear layer was greater in BALB/c mice than in C57BL/6 mice, suggesting strain differences in the oxidative defense system of photoreceptors and/or other modifier genes. Intravitreous injection of paraquat provides a new model of oxidative damage-induced retinal degeneration that is likely to be useful for testing new antioxidant treatments.
Medium modifications of light vector mesons in photoproduction reactions at JLab

Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer. The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the ρ vector mesons were investigated via their rare leptonic decay to e+e−. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The ρ meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the ρ meson in the nuclear medium rule out large medium effects. Transparency studies of the ω and vector mesons allow a determination of their widths in the medium.
Oxidation behaviour of β-sialon fabricated from α-Si3N4 and aluminium iso-propoxide

Β-sialon with z=0.5 was fabricated by hot pressing of a spray-dried mixture of α-Si3N4 and aluminium iso-propoxide solution. The oxidation behaviour of this Β-sialon was investigated, comparing it with commercial Β-sialon containing Y2O3 as a sintering aid. Oxidation tests were carried out at 1200 and 1400‡C for 25 to 200 h in air. The oxide layer of aluminium isopropoxide-derived Β-sialon was thin, dense, smooth and homogeneous without bubbles and cracks. The strength after oxidation at 1400‡C for 200 h was about 800 MN m−2, almost the same value as before oxidation. The oxide layer of Y2O3-doped Β-sialon was thick and inhomogeneous, containing many bubbles, cracks and grown needle-like crystallites (Y2Si2O7). The strength after oxidation at 1200‡C for 200 h fell to 1/2(440 MN m−2) because of pit formation in the oxide layer, and at 1400‡C for 200 h fell to 1/4(200 MN m−2) because of severe swelling and flaking of the oxide layer. The high oxidation resistance of aluminium iso-propoxide derived Β-sialon was mainly due to its homogeneous microstructure and freedom from foreign constituents such as Y2O3.
Seeding effects on crystallization temperatures of cordierite glass powder

The role of solid state epitaxy in the crystallization of nanocomposite cordierite glass to glass ceramic was investigated. The use of isostructural (α-cordierite) seeds in cordierite glass led to a lowering in the crystallization temperature to form glass ceramic by about 50 °C compared to the unseeded glass. The use of non-isostructural seeds such as ZrO2 and TiO2 did not lower the crystallization temperature of cordierite glass to glass ceramic, and in the case of the TiO2-seeded glass the crystallization temperature increased by about 50 °C compared to the unseededα-cordierite glass. The lowering in crystallization temperature byα-cordierite seeding can be attributed to the nucleation and epitaxial growth mechanism.
Factors affecting the performance of micromachined sensors based on Fabry–Perot interferometry

The noise and performance limitations of optical sensors that utilize Fabry–Perot interferometry detection are investigated. A Fabry–Perot interferometer consists of two partially transparent parallel plates with reflective inner surfaces. The plates form a cavity with an optical resonance that depends on the distance between them. At resonant wavelengths, the incident light energy is transmitted through the sensor and intensity peaks occur. The distance between the plates can be obtained by detecting the wavelength of the transmitted light. Various sensors can be based on Fabry–Perot interferometry, e.g. accelerometers, pressure sensors, and microphones. This paper considers factors affecting the performance of this type of sensor, including mechanical–thermal noise, contribution of noise in the detection system, and effects of reflectivity, surface roughness and parallelism of the mirrors. The presented experimental data support the results of the analysis.
Functional studies of single-site variants in the calmodulin-binding domain of RC3/neurogranin in Xenopus oocytes

Abstract Single-site variants in the calmodulin-binding domain of RC3/neurogranin were heterologously expressed in Xenopus oocytes to examine their effects on serotonin-evoked currents. RC3 variants serine 36 → alanine (Ser 36 → Ala), serine 36 → glycine (ser 36 → Gly), and phenylalanine 37 → tryptophan (Phe 37 → Trp), which bind calmodulin but are deficient in protein kinase C (PKC) phosphorylation, display serotonin-evoked Ca 2+ -dependent Cl − currents in oocytes similar to control oocytes. A serine 36 → aspartate (Ser 36 → Asp) variant, which does not bind calmodulin and mimics the PKC-phosphorylated state of RC3, significantly enhances serotonin-evoked currents in a manner similar to wild-type. The results suggest that RC3 not only regulates the availability of free calmodulin in a dendritic spine but also, when phosphorylated, independently stimulates G-protein coupled second messenger pathways that generate inositol 1,4,5-triphosphate (IP3), diacylglycerol (DAG) and intracellular Ca 2+ .
New results on scaling in the integral quantum Hall effect

We report two new results, from temperature dependent transport measurements in two In0.53Ga0.47As/InP heterostructures, concerning the scaling of electronic transport in the integral quantum Hall effect. First, in a sample which has spin resolved Landau levels N=0↓, 1↓, 1↑, we find that the extrema of dρxydB, d2ρxxdB2 and d3ρ xydB3 in all spin-split Landau levels diverge like T−α, with a=K, 2K, 3K respectively. The exponent, k=0.42 ± 0.04, uniquely describes the localization to delocalization transition. Moreover, by generalizing these results to higher order derivatives of the transport coefficients ρ, we find that Δρ((B)−ρ(B∗)) are invariant under a length scale transformation. Second, in a sample with lower mobility the spin splitting for the N=1 Landau level is not resolved for T>60 mK, we find that both dρxydB(B∗) and 1ΔB in the N=1 Landau level diverge as T−K2 for 60 mK < T < 2.5 K. On the other hand, both quantities follow T−K for the spin-split N=0↓ Landau level.
The effect of pituitary-adrenal function in the modulation of pain sensitivity in the rat.

1. The relationship between adrenalcortical hormones, adrenocorticotrophic hormone (ACTH), and pain sensitivity was investigated in the rat. Pain sensitivity was assessed by measuring paw-lick and jump latencies in response to being placed on a grid at 55 °C. 2. Bilateral adrenalectomy increased the sensitivity to pain, but adrenal demedullation had no effect. 3. Pain sensitivity was inversely related to the circadian changes in circulating corticosterone and was greater at 7 a.m. than at 7 p.m. However, the same variation in pain sensitivity existed if the adrenals were removed, suggesting that the increase in pain sensitivity after adrenalectomy was not related directly to the levels of corticosteriods. 4. The time course of the increase in pain sensitivity after adrenalectomy paralleled that of the changes in circulating ACTH. Adrenalectomy markedly increased pain sensitivity at 9 and 18 days following surgery when circulating ACTH levels were markedly elevated and corticosterone was absent, but not at 3 days following adrenalectomy when ACTH levels were lower and corticosterone was absent. 5. Hypophysectomy decreased the sensitivity to pain. 6. The results indicate that ACTH can alter pain sensitivity and that the effect of corticosteroids on the sensitivity to pain is an indirect one by virtue of their negative feed-back action on the hypothalamic-pituitary system.
Levels of Expression for BMP-7 and Several BMP Antagonists May Play an Integral Role in a Fracture Nonunion: A Pilot Study

Delays in bone healing or even the development of a nonunion could be related to the concentrations and/or functions of the bone morphogenetic proteins (BMPs). The RNA expression profile of the BMPs within fracture nonunion tissue is unknown. This preliminary descriptive study was performed to define the RNA profiles of the BMPs, their receptors, and their inhibitors within human fracture nonunion tissue and correlate them to matched healing bone. All patients had hypertrophic nonunions. Tissue samples taken from the nonunion site of 15 patients undergoing surgical treatment for an established nonunion were analyzed. The RNA expression patterns of BMP-2, BMP-4, BMP-5, BMP-6, BMP-7, BMP-8; BMP receptor Types IA, IB, and II; and the BMP inhibitors chordin, Noggin, Drm (Gremlin), and follistatin were determined in the nonunion (fibrous tissue) and healing bone (callus tissue) using quantitative real-time PCR. Comparison between the nonunion and healing bone samples revealed substantially elevated concentrations of BMP-4, Drm/Gremlin, follistatin, and Noggin in nonunion tissue when compared to healing bone. In contrast, BMP-7 concentration was higher in the healing bone. Our data suggest inhibition of BMP-7, by Drm (Gremlin), follistatin, and Noggin and upregulation of BMP-4 may play an integral role in the development of nonunions.
Tourism Experiences as a Stress Reliever Examining the Effects of Tourism Recovery Experiences on Life Satisfaction

The effect-recovery theory (Meijman and Mulder 1998) and the conservation of resources theory (Hobfoll 1998) suggest that taking a leisure trip provides opportunities for relaxation, detachment from work, mastery experience, and personal control. This research examined the role of tourism experiences as a stress reliever, particularly focusing on the underlying psychological experiences associated with recovery. Further, this research examined how these recovery experiences during a leisure trip influence perceived life satisfaction after the trip. It was found that all four dimensions of tourism recovery experiences had positive effects on life satisfaction. The results also revealed that even a weekend getaway can help people to recover from work stress, while longer trips provide more opportunities for recovery experiences.
Deep inelastic neutrino scattering and pion-nucleon cross sections

Abstract Source theoretic structure functions, the q 2 -dependent form of Adler's sum rule, and the hypothesis of an improved scaling variable that covers the full range of q 2 , correctly imply the asymptotic limit of the π ± p cross sections, 23 mb, as well as the nature of the approach of both cross sections to that limit.
Laser-induced fluorescence from the predissociating formyl radical. Part 2.—Analysis of dispersed emission from the Ã–X transition

Using laser-induced fluorescence spectroscopy dispersed emission spectra of HCO and DCO have been recorded. The formyl radical was produced by the UV photolysis of acetaldehyde (d0 and d4) and detected via the A2A″–X 2A′ transition, with excitation into single vibronic levels of the first excited state. We report, for the first time, emission into the overtone of the C—H stretching frequency, demonstrating the large anharmonic motion of this, the weakest of known CH bonds. Also, the fully resolved emission bands of DCO are shown. The three fundamental modes of DCO are observable, as a result of an accidental degeneracy of the three vibrational frequencies ω1≈ 2ω2≈ω3. The spectra are interpreted and the associated vibrational frequencies are calculated and compared with ab initio calculations. Additional bands recorded in the absence of a photolysis laser have been attributed to Raman scattering from the parent acetaldehyde.