cssi/SciSciGPT-SciSciNet huggingface dataset:
Hormone-electrolyte interactions in the pathogenesis of lethal cardiac arrhythmias in patients with congestive heart failure: Basis of a new physiologic approach to control of arrhythmia

Congestive heart failure is the most arrhythmogenic disorder in cardiovascular medicine. As left ventricular performance deteriorates and symptoms of dyspnea and fatigue become progressively more severe, nearly all patients with heart failure experience frequent and complex ventricular tachyarrhythmias and nearly half die suddenly during long-term follow-up. This imminent risk of sudden death appears to be present for all patients with congestive heart failure; ambulatory electrocardiographic monitoring and programmed electrical stimulation are not useful in distinguishing patient subsets that are particularly predisposed to fatal arrhythmic events. Although conventional antiarrhythmic agents are widely prescribed as a nonspecific approach to prevent sudden death in these patients, there is little evidence to indicate that these drugs possess clinically important antiarrhythmic activity in patients with congestive heart failure, and these agents frequently serve to exacerbate the heart failure state and the underlying ventricular tachyarrhythmia. A useful approach to the prevention of sudden death in patients with congestive heart failure addresses the reversible causes of lethal ventricular arrhythmias in these individuals. Both experimental and clinical evidence indicates that circulating neurohormones and electrolyte deficits (particularly of potassium and magnesium) interact to provoke malignant ventricular ectopic rhythms and that the prevention of electrolyte depletion and the use of neurohormonal antagonists may exert clinically important antiarrhythmic actions. This physiologic approach may prove to be a more effective means of ameliorating the problem of sudden death than the empiric administration of conventional antiarrhythmic drugs.
Promoting Character Development through Teaching Wrestling in Physical Education

Character development has become an important component of physical education that contributes directly to the affective learning domain. However, teaching character development can be challenging. The purpose of this article is to suggest that character development be promoted through the teaching of wrestling, due to the unique moral development experiences offered through participation in the sport. The article describes the ancient history and current popularity of wrestling among boys and girls, as well as the many benefits of participation, while providing solutions to the common challenges of implementing a wrestling unit in physical education. The article also suggests that physical educators use the teaching personal and social responsibility (TPSR) model through a “Pin it to Win it!” leveling system. The goals and levels of the TPSR model are discussed and specific examples are provided, including a lesson plan for use in a wrestling unit.
PET Scan 18F-Fluorodeoxyglucose Uptake and Prognosis in Patients With Resected Clinical Stage IA Non-small Cell Lung Cancer

Objective Our objective was to examine the association between 18 F-fluorodeoxyglucose (FDG) uptake on PET scan and prognosis in patients with surgically treated, clinical stage IA non-small cell lung cancer (NSCLC). Methods We reviewed data collection forms and Veterans Affairs administrative records of 75 patients with surgically treated, stage IA NSCLC who were enrolled in a prospective study of PET imaging from 1999 to 2001. We used Cox proportional hazards analysis to examine the association between FDG uptake and survival 4 years following enrollment. Results Most patients were men (97%), and the mean age was 68 ± 9 years. Almost half of the patients (44%) had adenocarcinoma, and 35% underwent a sublobar resection. The mean maximum standardized uptake value (SUVmax) was 4.9 ± 2.5 in survivors and 7.1 ± 3.9 in nonsurvivors ( P = .045). Before and after adjustment for age, tumor size, histology, and type of resection, the hazard of death was significantly higher in patients with squamous cell histology (adjusted hazard ratio [HR], 4.54; 95% CI, 1.09–18.9) and those with higher degrees of FDG uptake (adjusted HR, 1.21 per 1 unit increment; 95% CI, 1.01–1.45). At a threshold value of 5 for SUVmax, 34 of 39 patients (87%) with low FDG uptake survived, compared with only 24 of 36 patients (67%) with high FDG uptake ( P = .04). Visual assessment of FDG uptake was not associated with an increased hazard of death (HR 0.66; 95% CI, 0.19–2.29). Conclusions High FDG uptake as measured by SUVmax identifies individuals with clinical stage IA NSCLC who are at increased risk of death following surgery. Such high-risk patients may be good candidates for participation in future trials of adjuvant therapy.
Solubilization and removal of residual trichloroethene from porous media: comparison of several solubilization agents

The development of improved methods for remediation of contaminated subsurface systems has emerged as a significant environmental priority. One technology that appears to have considerable promise involves the use of solubilization-enhancing agents, such as surfactants, cosolvents, dissolved organic matter (DOM), and complexing agents, to promote removal of immiscible-liquid and sorbed phase organic contaminants. We examined the use of six flushing agents, i.e., two anionic surfactants, two complexing agents (cyclodextrins), a humic acid, and an alcohol, for solubilizing and removing residual-phase immiscible liquid from porous media. The results of batch experiments conducted to measure the degree of trichloroethene (TCE) solubilization induced by these agents show that the solubility of TCE was enhanced between 3 and 57 times depending on the flushing agent. Column experiments were conducted to compare water and agent-enhanced flushing of Borden sand containing residual saturations of TCE. As expected, the total flushing volume necessary to remove the residual saturation was reduced substantially in the presence of all applied agents. The relative effectiveness of the agents varied based on the method of evaluation. On a mass-efficiency basis, SDS outperformed all other agents, whereas DOM provided the best performance on a molar-efficiency basis.
Sexual Harassment: An Experimental Test of Sex-Role Spillover Theory:

This experimental study examined the ways in which knowledge of a woman's occupation type influenced how different types of sexual harassment were perceived. A total of 53 male and 58 female undergraduates were asked to evaluate six scenarios describing three types of harassment (unwanted sexual attention, gender harassment, and sexual coercion) at two levels of severity (nonphysical and physical) toward women in two different types of occupations (traditional and nontraditional). The results indicated that participants were less likely to perceive incidents of sexual coercion as harassing when a woman is in a nontraditional occupation. The results also provided evidence of a perceptual gap between men and women for incidents of unwanted sexual attention and gender harassment but not for incidents of sexual coercion. Results provide support for the sex-role spillover model of sexual harassment proposed by Gutek. Theoretical and legal implications of this research are discussed.
A class of 2-chromatic SQS(22)

Abstract We enumerate all 2-chromatic Steiner quadruple systems of order 22, having a cyclic automorphism of order 11 (i.e. 2 disjoint 11-cycles).
Myocardial infarction and tooth extraction associated

STUDY DESIGN This was a nested case control study within the Oslo study, which began in 1972/73 with the principle aim of studying prevention and epidemiology of cardiovascular diseases. INTERVENTION Within the Oslo study, men who attended for examination in both 1972/73 and 2000 with a self-reported history of MI (n=548) were compared to controls (n=625) selected at random from the same cohort, and matched by five-year strata for age. OUTCOME MEASURE Information on history of tooth extractions and the reasons for these extractions were obtained from a self-reported questionnaire. Reasons for tooth extractions were subgrouped into infection (marginal periodontitis and apical infection) or trauma/other causes. RESULTS Investigation of the association between the reason for extraction and MI, using prospective logistic analysis, found that extractions attributed to dental infections were significant predictors for risk factors in both 1972/73 and 2000. CONCLUSIONS There was an increased association between MI and tooth extraction due to dental infection compared with tooth extraction for trauma and other reasons.
Isospin restrictions on charge distributions in charmed-particle decays

The isospin properties of the semileptonic and non-leptonic charm-changing weak interactions lead to restrictions on the branching ratios of the different charge states that can occur in multi-particle decays of charmed particles. Upper and lower bounds imposed by isospin invariance on these ratios, and on the average number of charged decay products, are calculated for various charmed-particle decay modes. Simultaneous bounds on the branching ratios of two different charge distributions in the same decay mode, or in isospin-related decay modes, are presented. Branching ratios are also calculated under the statistical postulate that all the allowed invariant isospin channels contribute equally and incoherently in each decay mode.
Near surface elemental concentration gradients in annealed 304 stainless steel as determined by analytical electron microscopy

Elemental concentration profiles in the near surface region of 304 stainless steel resulting from hot-band annealing have been investigated with scanning transmission electron microscopy-energy dispersive X-ray spectrometry (STEM/EDS). A severe Cr depletion in the top 100 nm of the steel surface was observed, and a Ni enrichment was present at depths less than 1 μm. The maximum Cr depletion depth, which was approximated by an error function relationship, was in excellent agreement with the Cr depletion depth maximum determined experimentally. The oxide-alloy interfacial Cr concentration projected from the parabolic depletion profile of the 304 stainless steel at depths greater than 400 nm was also in reasonable agreement with the calculated value. The oxide/metal interfacial (within 50 nm) Cr concentration determined experimentally was, however, substantially lower than the calculated values. Doping effects on the oxide defect structure were proposed to enhance the diffusive flux from the alloy surface region and to contribute to nonparabolic growth effects of the Cr depletion profile in this region during short-term annealing.
Reactivity of cysteines in the transmembrane region of the Na, K-ATPase alpha subunit probed with Hg(2+).

To gain insight into the structure and conformational coupling in the Na,K-ATPase, this study characterized the reaction of the α1 subunit transmembrane cysteines with a small probe. Intact HeLa cells expressing heterologous Na,K-ATPase were treated with (μm) HgCl2 after placing the enzyme predominantly in either of two conformations, phosphorylated E2P.Na/E2P or dephosphorylated ATP.E1.K/ATP.E1. Under both conditions the treatment led to enzyme inactivation following a double exponential kinetic as determined by ouabain-sensitive K+ uptake measurements. However, the rate constant of the slow reacting component was ten times larger when the protein was probed in a medium that would favor enzyme phosphorylation. Enzymes carrying mutations of cysteines located in the α1 subunit transmembrane region were used to identify the reacting–SH groups. Replacement Cys104Ser reduced enzyme inactivation by removing the slow reacting component under both treatment conditions. Replacement of Cys964 reduced the inactivation rate constant of the fast reacting component (79%) and removed the slow reacting component when the dephosphorylated enzyme was treated with Hg2+. Moreover, Cys964Ser substituted enzyme was insensitive to Hg2+ when treated under phosphorylation conditions. These results indicate that Cys964 is involved in the fast inactivation by Hg2+. Although the double mutant Cys964, 104Ser was still partially inactivated by treatment under nonphosphorylating conditions, an enzyme devoid of transmembrane cysteines was insensitive to Hg2+ under all treatment conditions. Thus, this enzyme provides a background where accessibility of engineered transmembrane cysteines can be tested.
Another Way to Look at Spectral Asymptotics on Spheres

The exact spectrum of the Laplacian on spheres is well-known, and produces a relatively large remainder in the Weyl asymptotic formula. We observe that we can obtain an exact asymptotic formula with no remainder if we take a finite sum of terms involving powers and periodic functions.
Agrobacterium tumefaciens-mediated transformation of Fusarium circinatum

The development of a transformation system is a significant technical hurdle in the study of many filamentous fungi. Recently Agrobacterium tumefaciens was shown to transform several filamentous fungi, but until now only one independent confirmation of this promising finding has been published. Fusarium circinatum (teleomorph Gibberella circinata ) is an important pathogen of pine that has not been transformed previously. A. tumefaciens strain AGL1(pPK2) transformed three different isolates of F. circinalum with an efficiency of 2-150 transformants 10 −5 conidia. The T-DNA was integrated into the genome and was stable through mitotic and meiotic cell divisions. Most F. circinatum transformants contained a single T-DNA copy. Half of the tested transformants also contained non-T-DNA vector sequences. These findings should facilitate future analysis of F. circinatum pathogenicity and stimulate wider use of this valuable transformation method in fungal research.
The Cambrian Drumian carbon isotope excursion (DICE) in the Great Basin, western United States

The Global boundary Stratotype Section and Point (GSSP) of the Cambrian Series 3 (formerly the Middle Cambrian) Drumian Stage is defined by the first appearance datum (FAD) of the agnostoid trilobite Ptychagnostus atavus in the deep-water Wheeler Formation of the Drum Mountains in Utah, USA. In the Great Basin (USA), China and Scandinavia the FAD of P. atavus is associated with transgression and with a negative carbon isotope excursion named the Drumian Carbon isotope Excursion (DICE). However, the relationship between the FAD of P. atavus, sea-level changes, and the DICE is tentative, mainly due to the paucity of biostratigraphic data in shallow-water sections that limit correlation between deep- and shallow-water chemostratigraphic sections. An integrated sequence and chemostratigraphic study across a platform-to-basin transect in western Utah and southern Nevada indicates that the DICE is stratigraphically located above the FAD of P. atavus, associated with retrogradation of the shallow-water carbonate platform and with stratigraphic condensation in the basin. The results suggest that in future global correlations, the DICE should be restricted to the negative carbon isotope anomaly slightly post-dating the Drumian GSSP.
Immunohistological localization of melatonin in the rat digestive system.

The highest amount of melatonin (M), localized immunohistologically, was found in rectum, decreasing in the order: colon, duodenum, caecum, esophagus, stomach, ileum and jejunum. No M was found in the liver, spleen or pancreas. The distribution of M corresponds with the localization of serotonin-producing argentaffin cells.
Adaptive Methods of Two-Scale Edge Detection in Post-Enhancement Visual Pattern Processing

Adaptive methods are defined and experimentally studied for a two-scale edge detection process that mimics human visual perception of edges and is inspired by the parvo-cellular (P) and magno-cellular (M) physiological subsystems of natural vision. This two-channel processing consists of a high spatial acuity/coarse contrast channel (P) and a coarse acuity/fine contrast (M) channel. We perform edge detection after a very strong non-linear image enhancement that uses smart Retinex image processing. Two conditions that arise from this enhancement demand adaptiveness in edge detection. These conditions are the presence of random noise further exacerbated by the enhancement process, and the equally random occurrence of dense textural visual information. We examine how to best deal with both phenomena with an automatic adaptive computation that treats both high noise and dense textures as too much information, and gracefully shifts from a smallscale to medium-scale edge pattern priorities. This shift is accomplished by using different edge-enhancement schemes that correspond with the (P) and (M) channels of the human visual system. We also examine the case of adapting to a third image condition, namely too little visual information, and automatically adjust edge detection sensitivities when sparse feature information is encountered. When this methodology is applied to a sequence of images of the same scene but with varying exposures and lighting conditions, this edge-detection process produces pattern constancy that is very useful for several imaging applications that rely on image classification in variable imaging conditions.
EXPERT SYSTEM FOR ESTIMATES OF MOLECULAR WEIGHTS OF VOLATILE ORGANIC COMPOUNDS FROM LOW-RESOLUTION MASS SPECTRA

Abstract MAXMASS, the highest mass with an intensity of 5% of the base peak in a low-resolution mass spectrum, has been found to be linearly correlated with the true molecular weights of 400 randomly selected spectra, yielding a family of parallel lines. A simple expert system using MAXMASS has been developed to estimate molecular weights of unknown volatile compounds from their mass spectra. This is an empirical rule-based system which will run on a personal computer. It consists of a classification module chained to separate molecular weight prediction modules for six classes. These are benzenes, chlorobenzenes, bromoalkanes/alkenes, mono- and dichloroalkanes/alkenes, tri-, tetra- and pentachloroalkanes/alkenes, and unknown (other) classes. The rules were derived from National Institute of Standards and Technology (NIST) reference spectra of 75 target toxic compounds from the first five classes and 32 from the unknown class. Performance tests of molecular weight predictions were made with the expert system and the self training interpretive and retrieval system (STIRS) on NIST reference spectra of the 107 training compounds; on a set of 32 test NIST reference spectra of other compounds found in air samples; on a set of 100 randomly selected NIST reference spectra; and on 30 spectra taken from actual field gas chromatography-mass spectrometry (GC-MS) samples. The expert system performed much better than STIRS on training spectra, STIRS performed better on test and random spectra, and the expert system performed better with field data. The median absolute value deviation from the true results for the expert system was 1 and 3 mass units for training and field GC-MS spectra, respectively. Moreover, the expert system is much faster than STIRS.
PERIDINIUM GREGARIUM, A NEW SPECIES OF DINOFLAGELLATE1,2

SUMMARY A dinoflagellate has been found in tidepools on the coast of the Palos Verdes Peninsula in southern California. It is described as a new species, Peridinium gregarium. In the tidepool habitat, great numbers of the organism form cloud-like masses held together by a mucous matrix. The gregarious cloud formation seems to be shared by only one other species of dinoflagellate, Peridinium sociale (Henneguy ex Labbe) Biecheler, 1935.
Lignin‐polypropylene composites. Part 1: Composites from unmodified lignin and polypropylene

Lignin polypropylene composites were prepared in the range of 10–60% by weight lignin content. Blending of lignin with polypropylene resulted in materials with reduced tensile and flexural strength and a dramatic decrease in unnotched Izod impact strength compared to the properties of virgin polypropylene, although moduli (Young's and flexural) were improved. Traditional surface-treated fillers such as mica and talc performed better than lignin, but when lignin and inorganic fillers were mixed, the strength properties were improved with respect to lignin alone, perhaps because of a better lignin-filler-particle interaction and distribution. This could be an alternate approach for obtaining improved strength composites containing large quantities of unmodified kraft lignin. Incorporation of maleic anhydride grafted polypropylene (MAPP) as a coupling agent also improved strength properties, although at high lignin contents (e.g. 60%) there was considerable variability in the tensile strength.
Fifty-one flavonoids from Gutierrezia microcephala

Abstract The isolation of forty-five of the fifty-one flavonoids from aerial parts of Gutierrezia microcephala are described here. These forty-five flavonoids, together with six previously reported, make fifty-one flavonoids isolated from this species. There are eight new compounds: 5,7,2′,4′-tetrahydroxy-6,8,5′-trimethoxyflavone, 5,7,2′,4′-tetrahydroxy-8,5′-dimethoxyflavone, 5,7,3′,4′- tetrahydroxy-3,6,8,5′-tetramethoxyflavone, 5,6,3′,5′-tetrahydroxy-3,7,8,4′-tetramethoxyflavone, 5-hydroxy-3,6,7,8,3′, 4′,5′-heptamethoxyflavone, 3,5,3',4'-tetrahydroxy-6,7,8-tri-methoxyflavone, 5,3′-dihydroxy-3,6,7,8,4′-pentamethoxyflavone and 5,7,8,4'-tetrahydroxy-3,6-dimethoxyflavone.
Identifying Election Fraud Using Orphan and Low Propensity Voters

Although voter ID laws have become a hot topic of political debate, existing scholarship has failed to produce conclusive evidence concerning the existence or frequency of electoral fraud, especially the type of fraud that would be prevented by photo identification laws and signature verification protocols for voting by mail. We propose a new method of measuring election fraud, especially identity fraud, that is superior to previous measurement efforts because it measures actual instances of fraud rather than waiting for conclusive proof of fraud produced in a criminal prosecution. We test our method in multiple jurisdictions, including two known cases of electoral fraud, and we find no additional cases of fraud. We speculate that public access to voting and registration records play an important role in preventing this type of election fraud, suggesting that these practices are perhaps more important than voter ID laws in preventing election fraud.
The Seven States of California: A Natural and Human History

What explains California? To a large extent, as Philip Fradkin's rich, exuberant portrait makes clear, it's the multiple landscapes and the different states of mind that best define America's most populous, diverse, and fabled state. Fradkin divides California into seven distinct ecological and cultural provinces - from the hot deserts and high peaks to the rich agricultural Central Valley, the redwood forests of the north and sandy beaches of the south. Describing geographical regions based on their emblematic landscape features, Fradkin intertwines natural and social history.
Multidrug resistance and P-glycoproteins in parasitic protozoa

Drug resistance has emerged as a devasting impediment to the treatment and control of diseases of parasitic origin. The underlying mechanisms that contribute to this drug resistance in field isolates, however, are poorly understood. Members of the P-glycoprotein gene (pgp) family have been identified, cloned, and sequenced inPlasmodia, Leishmania, andEamonteba, and variations inpgp copy number and/or expression have been implicated as a basis for drug resistance in each of these genera. The spectrum of drugs to which parasitic protozoa containing amplifiedpgp genes and/or transcripts are refractory range from a phenotype similar to that observed with multidrug-resistant mammalian cells to those that are completely distinct. The availability of molecular probes topgp genes provides valuable reagents to dissect the role ofpgp gene amplification and overexpression in mediating drug resistance in parasitic protozoa and to determine the physiological function of P-glycoproteins in this clinically consequential group of human pathogens.
Plant-Feeding Hemiptera and Orthoptera Communities in Native and Restored Mesic Tallgrass Prairies

Aboveground Hemiptera and Orthoptera communities were compared among three native and three restored mesic tallgrass prairies along the Platte River in central Nebraska to assess both the relative success of restored sites and the relationship between insect and plant communities. Hemiptera and Orthoptera were sampled using sweep nets in early June, mid-July, and mid-August 2000. Plant species composition was assessed in early June and mid-August. A total of 89 Auchenorrhyncha (71 Cicadellidae, 15 Fulgoroidea, and 3 Membracidae) and 23 orthopterans (15 Acrididae and 8 Tettigoniidae) were collected. Eighty-five plant species were observed in combined study sites. Shannon diversity was significantly higher at restored prairie for Cicadellidae (H′= 1.38), Fulgoroidea (H′= 0.796), and Membracidae (H′= 0.290), which comprised the majority of individual insects collected, but significantly higher at native prairie for Acrididae (H′= 0.560) and Tettigoniidae (H′= 0.480) (p≤ 0.05). Species richness was comparable except for Acrididae which were significantly higher in restored prairie. Density of insects generally followed species diversity but was only significantly higher in restored areas for Membracidae. The number of remnant-dependent species collected was comparable for both native prairie (n= 15) and restored prairie (n= 15). These results suggest that, at least for Hemiptera, differences in insect communities between native and restored prairie may best be explained by the presence of insect host plants rather than by whether a site is native or restored.
Isolation of the murine branched-chain α-ketoacid dehydrogenase E2 subunit promoter region

Abstract The promoter region of the murine branched-chain α-ketoacid dehydrogenase E2 subunit (dihydrolipoyl transacylase) gene was isolated and characterized. Sequence analysis of the promoter-regulatory region showed the presence of two inverted ‘CAAT box’ sequences, the most proximal being −42 to −48 bp upstream from the determined transcription initiation site, but no TATA-box sequences, similar to the human BCKAD E2 gene. The boundary of the minimum promoter sequence appeared to reside just inclusive of this first inverted CAAT sequence, but minigene transfer analysis demonstrated that the promoter proximal region between −65 and −140 bp is likely to be extremely important for controlling regulated changes in E2 RNA expression. The regulatory effect of this region may be modulated by a number of other upstream regions which were identified within the 7.0 kb sequence examined.
Further studies on the use of classifiers for the control of wet grinding circuits

Abstract The use of inferential particle sizing for wet grinding circuit control is well established in the literature. In this paper an analytical development is presented which yields a general inferential sizing model relating circuit product size to d 50 corrected for the circuits' classifier. It is then shown how the different forms of empirical equations reported in the literature can arise, depending on the range of the operating variables and the ratio of feed 50% passing size to d 50 corrected. Following this development, data show pilot plant and industrial plant operations to behave as predicted by the general inferential size model.
High-performance integrating infrared detector

Abstract Improvement in the performance of a Si: P integrating infrared (IR) detector are described. The detector has the structure of a p-i-n diode but the mode of IR detection involves photoemission of charge stored in localized impurity states in the i-region at low temperatures. After IR exposure, the remaining occupied localized states are field ionized. In order to measure the remaining charge, the transient field ionization current is digitized and integrated. Increased quantum efficiency is obtained by increasing the photosensitive i-region thickness and impurity concentration. With increasing impurity concentration, the quantum efficiency of a 110 μm thick detector can be increased from 0.5% to about 70% in the neighborhood of 27 μm while the maximum charge storage time (IR integration time) decreased from more than 12 h to about l s.
Proving Our Worth: The Impact of Electronic Resource Usage on Academic Achievement

Samford University Library conducted a study to determine correlation between library use and student achievement. This research used electronic resources as a measure of library use and grade point average as an indicator of academic success. The data demonstrate that students with higher GPAs tend to use library online resources more and with a higher frequency than those with lower GPAs. While this does not prove that use of online resources leads to a higher GPA, it provides strong evidence that the two are positively correlated for some populations. This study provides persuasive evidence of the library's contribution to the academic success of students.
The information content of a convertible debt offer announcement

We develop a model of convertible debt financing that combines issue and call decisions into a common framework. The model suggests a role for refinancing costs in a manager's efforts to signal firm productivity to investors by an appropriate choice of debt issue terms. A cross section of convertible debt offers can be divided into two groups: a high conversion ratio group and a low conversion ratio group. The model predicts that high conversion ratios are negatively correlated with offer announcement stock returns and low conversion ratios are uncorrelated with offer announcement stock returns. The model is tested on a sample of 124 convertible debt offer announcements. Test results support model accuracy.
Impaired immunoglobulin M synthesis by peripheral blood lymphocytes in systemic lupus erythematosus: A primary B-cell defect

Abstract Peripheral blood lymphocytes from 20 patients with systemic lupus erythematosus (SLE) were defective in their ability to secrete immunoglobulin M (IgM) in a pokeweed mitogen (PWM)-stimulated in vitro culture system. To characterize this abnormality, the mononuclear cells were separated into three functional subpopulations: (i) bone marrow-derived (B) cells which secrete immunoglobulin; (ii) a thymus-derived (T) lymphocyte fraction; and (iii) an irradiated T-cell fraction with predominant helper function. Coculture experiments with subsequent radioimmunoassay of the quantity of immunoglobulin secreted allowed comparisons of the immunoregulatory functions of the SLE-helper T, SLE suppressor T, and SLE B cells with functions of control lymphocyte fractions. The major defect defined was an inability of the SLE B cell to secrete normal amounts of IgM. This was not due to suppression by monocytes since the removal of phagocytic cells and the addition of separated monocytes to the cultures demonstrated generation of normal helper signals by SLE monocytes. Nor were inadequate numbers of IgM secreting B cells available since limiting dilution studies showed a normal precursor frequency of PWM-stimulatable, IgM secreting SLE B cells. SLE T cells showed a normal helper effect on the secretion of IgM by control B cells. Thus, these in vitro coculture studies designate a primary immunologic defect in SLE to the B cell and not in the suppressor or helper functions of the T cell.
Plasma cholesterol level after hepatopancreatobiliary surgery provides information on the postoperative clinical course.

Hypocholesterolemia is commonly considered an index of malnutrition. Conversely, major surgical procedures such as liver resection or pancreaticoduodenectomy and the possibly related adverse events such as sepsis, major bleeding, or other complications may cause a reduction in plasma cholesterol to values even lower than 30 mg/dl. Therefore, in this case, the severity of hypocholesterolemia often becomes an index of severity of illness with relevant prognostic value [1–3]. In spite of the fact that cholesterol may be influenced by various other factors, the evolution of hypocholesterolemia (the trend toward worsening or resolution, or the protracted persistence of severe hypocholesterolemia) provides useful information on the clinical evolution of the patient. It is worth outlining the mechanisms which are involved in the development of hypocholesterolemia and some practical cues for its interpretation. Plasma cholesterol behaves like albumin, whose levels tend to decrease in conditions of stress, such as after surgical trauma and with the occurrence of complications (sepsis, liver insufficiency, and hemorrhage). The mechanisms involved in decreasing cholesterol may include the effect of inflammatory mediators, the insufficient hepatic synthesis of cholesterol, and hemodilution, the latter being related to blood loss and fluid reinfusion [4]. The final effect is cumulative, and the severity of hypocholesterolemia reflects the importance of the adverse factors which determine the severity of illness. In our experience, after liver resection, the reduction in cholesterol, with respect to the preoperative value, is
The Phillips curve behavior over different horizons

This article examines the historical behavior of the Phillips curve over frequency bands corresponding to the short run, the business cycle and long run horizons. Data transformed using band-pass filtering methods and the Hodrick-Prescott filter suggest that a negative correlation between inflation and unemployment and a positive correlation between inflation and output growth exist within the business cycle horizon of 3 to 8 years. During the post-war period, the relationships change signs at low frequencies, indicating a positive sloped Phillips curve over long horizons. Additionally, the Phillips curve is found structurally unstable not only across frequencies, but also over time.
Regulation of insulin-like growth factors I and II and their binding proteins in human bone marrow stromal cells by dexamethasone.

Glucocorticoids inhibit the proliferation, but induce the differentiation, of bone marrow stromal cells into osteoblast-like cells. The mechanisms, however, are still conjectural. Since insulin-like growth factors (IGFs) have profound effects on osteoblast growth and differentiation, it is possible that glucocorticoids exert their effects on bone marrow stromal cells in part via regulation of IGFs. Therefore, we analyzed the effects of dexamethasone (Dex) on the expression of IGF I and IGF II in cultured preosteoblastic normal human bone marrow stromal cells (HBMSC). Whereas Dex decreased the concentration of IGF I in the conditioned medium since early in the treatment, the concentration of IGF II was increased progressively as culture period lengthened. As the activities of IGF I and IGF II are regulated by the IGF binding proteins (IGFBPs), we analyzed the effects of Dex on the expression of IGFBPs. Dex increased IGFBP-2 in a time-dependent manner. The increase in IGFBP-2, however, was only to the same extent as that of IGF II at most, depending on the length of treatment. Therefore, the increase in IGFBP-2 would dampen, but not eliminate, the increased IGF II activities. By contrast, Dex decreased IGFBP-3 levels, the latter increasing the bioavailability of IGF II. Although IGFBP-4 mRNA levels were stimulated by Dex, IGFBP-4 concentration in the conditioned medium was unchanged as measured by RIA. IGFBP-5 and IGFBP-6 mRNA levels were decreased by Dex in a time-dependent fashion. IGFBP-5 protein level was also decreased 1–4 days after Dex treatment. IGFBP-1 mRNA was not detectable in HBMSC. These accumulated data indicate that Dex regulates IGF I and IGF II and their binding proteins differentially in normal human bone marrow stromal cells. The progressive increase in IGF II may contribute to Dex-induced cell differentiation. J. Cell. Biochem. 71:449–458, 1998. © 1998 Wiley-Liss, Inc.
Intercellular channels in teleosts: functional characterization of two connexins from Atlantic croaker

Gap junction channels, composed of protein subunits termed connexins, are believed to play a critical role in the process of oocyte differentiation and maturation. We have used the paired Xenopus oocyte assay to characterize functionally two connexin genes, connexin-32.2 and connexin-32.7, recently cloned from the ovary of the Atlantic croaker (Micropogonia undulatus), a species that has emerged as a useful model to study the process of maturation of the ovarian follicle. We have found that, while both connexin proteins were expressed at comparable levels in Xenopus oocytes, only one, connexin-32.2, was functionally competent to induce the formation of intercellular channels. Connexin-32.2 channels exhibited voltage-dependent closure that was similar to, but distinct from that of previously characterized mammalian connexins. In addition, the silent connexin-32.7 was unable to functionally interact with connexin-32.2, either in heterotypic channels or as dominant negative inhibitor. Because connexin-32.2 expression is strikingly regulated during oocyte maturation, these data provide further evidence for a role of intercellular channels in the control of oocyte-follicular cell interactions.
Vortex modification of diffusion flamelets

The structure of a diffusion flame near a vortex is investigated by numerical simulation of the conserved-scalar field and analytical estimates of the convective-reactive-diffusive balance. Over a wide range of Peclet numbers, the stoichiometric contour is only partially wrapped around the vortex forming a flame tongue. At the flame tip the compressive strain rate is tangent to the reaction sheet, significantly diminishing normal gradients. The convection tangential to the sheet then creates a convective-reactive balance of thermal enthalpy, in contrast to the usual diffusive-reactive balance produced by compressive strain normal to the sheet. The tip region is thereby predicted to become the hottest part of the flamelet, which appears to agree with experimental observations.
Maintaining diversity in an artificially propagated population

Populations may suffer unexpected loss or distortion of biodiversity as a consequence of strategies employed in artificial propagation programs. The Trinity River Fish Hatchery may have inadvertently experienced this while attempting to preserve diversity in a return time within a Chinook salmon population. We develop a model for this system and prove that the long-term distribution of return types converges and that it is strongly tied to the management strategy. Given estimates of heritabilities for return type and differential survival rates, an estimate of this long-term distribution can be computed easily.
The US Rare Isotope Accelerator project

The Rare Isotope Accelerator (RIA) is a next generation radioactive beam facility in preparation in the US. RIA combines the best of standard ISOL and in-flight fragmentation technology with novel approaches to handle high-primary beam power and remove existing limitations in the extraction of short-lived isotopes. The use of a versatile primary accelerator (superconducting linac designed to allow multiple charge state acceleration and capable of providing beams from protons at 900 MeV to uranium at 400 MeV/u at power levels up to 400 kW) allows various production and extraction schemes to be used to optimize production of specific isotopes. In particular, a novel approach where radioactive isotopes produced by fragmentation of a fast heavy-ion beam are stopped and cooled in a high-purity helium gas cell and extracted by electromagnetic fields as thermal singly charged ions promises huge increases in efficiency for very short-lived isotopes. These isotopes will then be available for studies at ion source energy or can be further accelerated by a second superconducting linac whose novel injection system, based on CW low-frequency RFQs, allows the efficient acceleration of singly-charged heavy ions with masses up to 240 amu. from ion source energy. The high-intensity radioactive beams at RIA will be made available to four experimental areas spanning the energy regime from ion source energy to primary beam energy.
Reversal of Dexamethasone Inhibition of Adrenocorticotropin Release in a Mouse Pituitary Tumor Cell Line Either by Growing Cells in the Absence of Dexamethasone or by Addition of Hypothalamic Extract

Release of ACTH by a mouse pituitary tumor cell line (AtT-20/D-16v) is inhibited by 10-8-10-6 M 9α-fluoro- 16α-methyl-11β, 17α,21-trihydroxy- 1,4-pregnadiene- 3,20-dione (dexamethasone). Dexamethasone does not inhibit cell growth in this concentration range. Cortisol and corticosterone are almost as potent as dexamethasone in inhibiting ACTH release, whereas 17β-estradiol and testosterone have no effect. In rapidly growing cultures of tumor cells removal of dexamethasone leads to complete reversal of the inhibitory effect of the steroid on ACTH accumulation in culture medium within 4–5 days (3.5–4 generation times). The extent of reversal of the dexamethasone effect in slowly growing cultures (generation time 96–150 h) and in rapidly growing cultures (24–30 h) is proportional to the amount of growth that takes place in the absence of dexamethasone. Addition of hypothalamic extract to dexamethasonetreated cultures and to untreated cultures stimulates the release of ACTH 4- to 8-fold. The response occurs wi...
Late Cenozoic Sr isotope evolution of the Arctic Ocean: constraints on water mass exchange with the lower latitude oceans

Direct measurements of the Sr isotope composition of the different water masses that comprise the chemically and thermally stratified modern Arctic Ocean yield 87Sr86Sr ratios that are homogeneous and identical (i.e. within an error of < 1 × 10−5) to the 87Sr86Sr ratio of the lower latitude oceans. Variations in the 87Sr86Sr ratios of planktonic foraminifera from the Arctic Ocean, which define the Sr isotope composition of shallow Arctic seawater, follow the Sr isotope variations of the lower latitude oceans over the past 0.9 Ma. These new Sr isotope data support the chronostratigraphy previously established for the Pleistocene Arctic Ocean. Moreover, the results indicate that although the Arctic Ocean is nearly an enclosed basin and river-runoff constitutes a significant portion of the modern surface waters, the Arctic Ocean has been in Sr isotope equilibrium with the world ocean throughout most of the Quaternary. This conclusion is clearly supported by data for samples younger than 0.9 Ma, and is probably valid for the Sr isotope compositions of samples that are as old as 1.6 Ma. Because the Sr isotope data suggest water mass exchange between the Arctic and the world ocean during the Pleistocene, it follows that the Arctic Ocean has probably been an important factor in global climate over this time interval.
Latent Class Analysis of Antisocial Behavior: Interaction of Serotonin Transporter Genotype and Maltreatment

To improve understanding about genetic and environmental influences on antisocial behavior (ASB), we tested the association of the 44-base pair polymorphism of the serotonin transporter gene (5-HTTLPR) and maltreatment using latent class analysis in 2,488 boys and girls from Wave 1 of the National Longitudinal Study of Adolescent Health. In boys, ASB was defined by three classes (Exclusive Covert, Mixed Covert and Overt, and No Problems) whereas in girls, ASB was defined by two classes (Exclusive Covert, No Problems). In boys, 5-HTTLPR and maltreatment were not significantly related to ASB. However, in girls, maltreatment, but not 5-HTTLPR, was significantly associated with ASB. A significant interaction between 5-HTTLPR and maltreatment was also observed, where maltreated girls homozygous for the short allele were 12 times more likely to be classified in the Exclusive Covert group than in the No Problems group. Structural differences in the latent structure of ASB at Wave 2 and Wave 3 prevented repeat LCA modeling. However, using counts of ASB, 5-HTTLPR, maltreatment, and its interaction were unrelated to overt and covert ASB at Wave 2 and only maltreatment was related to covert ASB at Wave 3. We discuss these findings within the context of sex differences in ASB and relevant models of gene-environment interplay across developmental periods.
Selective inhibition of phosphodiesterase 1 relaxes urinary bladder smooth muscle: role for ryanodine receptor-mediated BK channel activation

The large conductance voltage- and Ca(2+)-activated K(+) (BK) channel is a major regulator of detrusor smooth muscle (DSM) excitability and contractility. Recently, we showed that nonselective phosphodiesterase (PDE) inhibition reduces guinea pig DSM excitability and contractility by increasing BK channel activity. Here, we investigated how DSM excitability and contractility changes upon selective inhibition of PDE type 1 (PDE1) and the underlying cellular mechanism involving ryanodine receptors (RyRs) and BK channels. PDE1 inhibition with 8-methoxymethyl-3-isobutyl-1-methylxanthine (8MM-IBMX; 10 μM) increased the cAMP levels in guinea pig DSM cells. Patch-clamp experiments on freshly isolated DSM cells showed that 8MM-IBMX increased transient BK currents and the spontaneous transient hyperpolarization (STH) frequency by ∼2.5- and ∼1.8-fold, respectively. 8MM-IBMX hyperpolarized guinea pig and human DSM cell membrane potential and significantly decreased the intracellular Ca(2+) levels in guinea pig DSM cells. Blocking BK channels with 1 μM paxilline or inhibiting RyRs with 30 μM ryanodine abolished the STHs and the 8MM-IBMX inhibitory effects on the DSM cell membrane potential. Isometric DSM tension recordings showed that 8MM-IBMX significantly reduced the spontaneous phasic contraction amplitude, muscle force integral, duration, frequency, and tone of DSM isolated strips. The electrical field stimulation-induced DSM contraction amplitude, muscle force integral, and duration were also attenuated by 10 μM 8MM-IBMX. Blocking BK channels with paxilline abolished the 8MM-IBMX effects on DSM contractions. Our data provide evidence that PDE1 inhibition relaxes DSM by raising cellular cAMP levels and subsequently stimulates RyRs, which leads to BK channel activation, membrane potential hyperpolarization, and decrease in intracellular Ca(2+) levels.
Perceptual and conceptual training mediate the verbal overshadowing effect in an unfamiliar domain

Describing memory for a nonverbal perceptual stimulus can impair recognition. This verbal overshadowing effect may occur when perceptual expertise exceeds verbal expertise, but previous evidence for this hypothesis has been strictly correlational. We conducted two experiments, exploring the relation between expertise and verbal overshadowing by manipulating perceptual and conceptual knowledge. Participants received perceptual training (categorizing mushrooms), conceptual training (lecture), or no training, then viewed a mushroom and described it or not. A recognition test followed. In Experiment 1, perceptual training increased susceptibility to verbalization relative to the no training condition. However, conceptual training did not insulate individuals from the verbal overshadowing effect. Experiment 2 was modified to enhance both forms of training. It replicated the finding that perceptual training increases vulnerability to verbal overshadowing, and indicated that, when sufficiently emphasized, verbalization may be useful following conceptual training. The results demonstrate the role that different forms of learning and expertise may play in mediating language influences on recognition memory.
Nonblocking networks for fast packet switching

An extension of the classical theory of nonblocking networks is identified and studied that is applicable to multirate circuit and fast packet/ATM switching systems. Conditions are determined under which the Clos, Cantor, and Benes networks are strictly nonblocking. Conditions are also determined under which the Benes network and variants of the Cantor and Clos networks are rearrangeable. It is found that strictly nonblocking operation can be obtained for multirate traffic with essentially the same complexity as in the classical context. >