cssi/SciSciGPT-SciSciNet huggingface dataset:
TH‐D‐342‐03: Advanced CT Source and Detector Technologies

The source and detector subsystems are critical for the performance of a CT scanner. Technical advances in these components have been necessary to enable the progress that CT has achieved in recent years, and, in some respects, improvements in these technologies have driven system‐level advances. It is appropriate, therefore, to explore what further advances are possible in these components and what these changes would mean to CT system performance. We will examine these issues with a particular focus on the desire to improve dose‐efficiency, scanning speed, and volumetric coverage, and to develop new applications. X‐ray sources fir clinical CT have become much more powerful and rugged, evolutions driven by the increase in scanning speed. Modern sources allow for a small amount of beam deflection to improve projection sampling. Wider volumetric coverage in a single rotation will be facilitated if the sources with multiple spot locations in the axial direction. Very rapid kVp switching would provide improved multi‐energy imaging. The predominant technology in CTdetectors is energy integrating devices composed of scintillators with coupled photodiodes. While CTdetectors have high DQE compared to some other x‐ray based technologies, there is room for improvement, especially at low exposure rates and high spatial frequencies. Direct conversion detectors could provide higher spatial sampling frequencies without loss of geometric efficiency from reflectors. Photon countingdetectors could provide a significant improvement in performance, especially if the detectors also provide energy discrimination. The challenges and opportunities from these technologies will be discussed. Research sponsored by GE Healthcare.
Cultivation of Mouse-adapted Dengue Virus (Type 1) in Rhesus Monkey Tissue Culture

Although dengue virus has been successfully adapted to mice, attempts to cultivate it in tissue culture have so far yielded only negative or questionable results (Sabin, 1952; Hotta, 1952). The only reported exception is contained in a short discussion by Schlesinger (1950) of experiments in which dengue virus was propagated in 5-day-old chick embryo tissue. t In the present paper experiments are reported in which two strains of type 1 dengue virus were cultivated in tissue culture.
Scientific evaluation of the safety factor for the acceptable daily intake (ADI). Case study: butylated hydroxyanisole (BHA).

The principles of ‘data‐derived safety factors’ are applied to toxicological and biochemical information on butylated hydroxyanisole (BHA). The calculated safety factor for an ADI is, by this method, comparable to the existing internationally recognized safety evaluations. Relevance for humans of forestomach tumours in rodents is discussed. The method provides a basis for organizing data in a way that permits an explicit assessment of its relevance.
Three-track care: Older patient, family member, and physician in the medical visit

Abstract When older patients come to medical appointments accompanied by a family member, patterns of interaction ensue that reflect uncertainties about the capabilities and responsibilities of each person in this triad. In this study, ongoing discourse from 40 transcribed medical visits with an elderly patient, family caregiver, and physician were analyzed. Interactive behaviors that support patient self care capabilities and those that support dependency are identified and described, and patterns of interaction related to the patients' cognitive or sensory impairments are explored. The presence of a family member at an older patient's medical visit—in combination with the authoritarian traditions of medical care, assumptions about frailty and aging, and true impairment—appears to trigger behaviors that marginalize the patient and that are supportive of dependent self care. Behaviors that support independent self care are less evident. An awareness of this tendency toward dependent supportive interactions may enable physicians, family members, and patients to change this pattern, breaking the cycle of increasing dependence and supporting instead the patient's adult independent status in the clinic setting.
Adoption of the AHCPR Clinical Practice Guideline for Smoking Cessation: a survey of California's HMOs.

Abstract Objective: Our objective was to assess the degree to which health maintenance organizations (HMOs) and Medicaid managed care (MMC) plans in California have adopted the 1996 AHCPR Clinical Practice Guideline for Smoking Cessation . (AHCPR [U.S. Agency for Health Care Policy and Research] was renamed AHRQ [Agency for Healthcare Research and Quality] in 1999.) Methods: A fax survey of 13 licensed HMOs and 21 MMC plans operating in California in 1999 with up to 10 follow-up contacts by telephone, mail, fax, and/or electronic mail. Results: Awareness of the AHCPR guideline is widespread, and all HMOs in California in 1999 offered coverage for at least one treatment for smoking cessation. We found that 77% of the HMOs in California were aware of the AHCPR guideline, but less than half had used it to design benefits or distribute treatment guidelines to medical care providers in their networks. While only 23% of California HMOs covered the nicotine patch or gum, 69% covered at least one form of the pharmacotherapy and one type of counseling to treat tobacco dependence. In addition, a majority of the HMOs and MMC plans inform their members about coverage for smoking cessation treatments and inform providers about their role in helping smokers to quit. Conclusion: Considerable progress has been made in increasing access to effective smoking cessation treatments in California's managed care organizations over the last 10 years. Future efforts and research must concentrate on: (1) adopting the 2000 Public Health Service Clinical Practice Guideline on Treating Tobacco Use and Dependence , (2) increasing purchaser demand for coverage of tobacco dependence treatments, (3) increasing health plan documentation and monitoring of member smoking status, and (4) increasing provider provision of effective tobacco dependence treatments.
Imaging the Impact of Prenatal Alcohol Exposure on the Structure of the Developing Human Brain

Prenatal alcohol exposure has numerous effects on the developing brain, including damage to selective brain structure. We review structural magnetic resonance imaging (MRI) studies of brain abnormalities in subjects prenatally exposed to alcohol. The most common findings include reduced brain volume and malformations of the corpus callosum. Advanced methods have been able to detect shape, thickness and displacement changes throughout multiple brain regions. The teratogenic effects of alcohol appear to be widespread, affecting almost the entire brain. The only region that appears to be relatively spared is the occipital lobe. More recent studies have linked cognition to the underlying brain structure in alcohol-exposed subjects, and several report patterns in the severity of brain damage as it relates to facial dysmorphology or to extent of alcohol exposure. Future studies exploring relationships between brain structure, cognitive measures, dysmorphology, age, and other variables will be valuable for further comprehending the vast effects of prenatal alcohol exposure and for evaluating possible interventions.
Dysgenesis mesodermalis der Hornhaut und Iris mit gleichzeitigem Vorkommen von neuroektodermalen Entwicklungsstörungen

Einer oder mehrere der charakteristischen Befunde von Dysgenesis mesodermalis der Hornhaut und Iris konnen sich mit neuroektodermalen Fehlbildungen kombinieren, einschlieslich verschiedener Tumoren neuroektodermalen Ursprunges, und konnen Anlas zu Fehldiagnosen geben. Auffallige corneale Bilder konnen dabei besonders irrefuhrend wirken.
Aging of Ultra-Thin Niobium Films

We characterize the evolution of the electrical properties of ultra-thin niobium films stored in ambient conditions over a period of approximately seven months. Patterned films with thicknesses between 8 and 16 nm were fabricated via electron-beam deposition on unheated silicon substrates using a lift-off process. The film quality is similar to previous results obtained with sputter deposition onto unheated silicon substrates. The increase of the resistance and the decrease of the superconducting critical temperature are well described by an exponential function with a time constant of approximately 37 days.
Language and social change in Java : linguistic reflexes of modernization in a traditional royal polity

Errington explores linguistic evidence of social change among the traditional priyayi elite of Surakarta in south-central Java. Employing data from texts, interviews, observed speech, and questionnaires, he shows a progressive leveling in the language used to denote traditional status differences, and he demonstrates how perceptions of speech styles reflect etiquette and the views of the users. Errington suggests that a reciprocal assimilation process changes the way members of Java's traditional elite deal with each other in a modern urban milieu. The argument and the material on which it is based will be of interest to historians, linguists, anthropologists and other concerned with social and political change in southeast Asia.
Nilgiri langur (Presbytis johnii) territorial behavior

During 1250 hours of observation 84 intertroop encounters were witnessed suggesting territorial behavior. Most of these involved an exchange by adult males of visual and/or vocal signals. Chasing was rare, and when it occurred, it seemed to be “ritual chasing.”
Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Acute Carbon Monoxide Poisoning

This clinical policy focuses on critical issues concerning the management of adult patients presenting to the emergency department (ED) with acute symptomatic carbon monoxide (CO) poisoning. The subcommittee reviewed the medical literature relevant to the questions posed. The critical questions are: Should hyperbaric oxygen (HBO2) therapy be used for the treatment of patients with acute CO poisoning; and Can clinical or laboratory criteria identify CO-poisoned patients who are most or least likely to benefit from this therapy. Recommendations are provided on the basis of the strength of evidence of the literature. Level A recommendations represent patient management principles that reflect a high degree of clinical certainty; Level B recommendations represent patient management principles that reflect moderate clinical certainty; and Level C recommendations represent other patient management strategies that are based on preliminary, inconclusive, or conflicting evidence, or based on committee consensus. This clinical policy is intended for physicians working in hospital-based EDs.
Rolling Contact Fatigue Evaluation of Bearing Materials and Lubricants

Modern aircraft are pushing bearing temperatures beyond the limits of standard steels and lubricating fluids. Newer materials are introducing serious uncertainties into design life calculations. So many parameters and such a spread of statistical phenomena are involved that a “bench” type tester is essential as a substitute for full scale bearing tests to screen material-lube combinations. A high temperature tester has been built, and several months of testing at 400°F have emphasized the magnitude of the problem by showing that (a) the state of oxidation of diesters is a significant factor with several materials, (b) life can vary appreciably between apparently similar heats of steel, (c) hardness is an important factor that needs much more study, (d) standard cleanliness measurements do not seem to be sufficient to establish relative quality. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October 1958.
Accuracy of 4-dimensional computed tomography in poorly localized patients with primary hyperparathyroidism.

Background Four-dimensional computed tomography (4D-CT) utilizes multiplanar images and perfusion characteristics to identify abnormal parathyroid glands. We assessed the role of 4D-CT in patients with inconclusive preoperative ultrasound and sestamibi localization studies. Methods Adult patients with primary hyperparathyroidism with negative or discordant standard imaging who underwent both localization with 4D-CT and operative intervention for curative intent were included. Patient characteristics, 4D-CT scan results compared with operative findings, and curative proportion were assessed. Results Of the 60 patients, 4D-CT accurately lateralized 73% and localized 60% of abnormal glands found at operation. Single candidate lesions (46/60) were confirmed at operation in 70%. When multiple lesions were identified on 4D-CT (14/60), accuracy dropped to 29% (P = .03). The accuracy of 4D-CT was not different between primary and reoperative cases (P = .79). Of the 8 patients with multigland disease diagnosed perioperatively, 5 had multiple candidate lesions noted on 4D-CT. In 94% (48/51) of patients, a >50% drop in intraoperative parathormone (IOPTH) level was achieved after resection and 87% (48/55) had long-term cure with a median follow-up of 221 days. Conclusion 4D-CT identifies the more than half of abnormal parathyroids missed by traditional imaging and should be considered in cases with negative or discordant sestamibi and ultrasound. Bilateral exploration is warranted when multiple candidate lesions are reported on 4D-CT. Multigland disease remains a challenging entity.
Surgically Induced Chronic Kidney Disease May be Associated with a Lower Risk of Progression and Mortality than Medical Chronic Kidney Disease

Purpose: Chronic kidney disease from medical causes is present in 25% to 30% of patients before surgery for renal cancer. Although chronic kidney disease due to medical causes is typically associated with a 2% to 5% annual renal functional decline and decreased overall survival, reduced glomerular filtration rate occurring only after surgery may not have the same negative consequences.Materials and Methods: All patients undergoing surgery for suspected renal malignancy were identified in an institutional registry. Median clinical followup was 6.6 years.Results: Of 4,180 patients 28% had a preoperative glomerular filtration rate of less than 60 ml/minute/1.73 m2 (chronic kidney disease due to medical causes) and in 22% the glomerular filtration rate decreased to less than 60 ml/minute/1.73 m2 only after surgery (surgically induced chronic kidney disease). Preoperative glomerular filtration rate was a strong predictor of overall survival on univariable and multivariable analysis. The risk of death after ren...
The Role of Smoking and Other Modifiable Lifestyle Risk Factors in Maintaining and Restoring Lower Body Mobility in Middle‐Aged and Older Americans: Results from the HRS and AHEAD

OBJECTIVES: To analyze the effect of smoking, smoking cessation, and other modifiable risk factors on mobility in middle-aged and older Americans. DESIGN: Panel study; secondary data analysis. SETTING: United States (national sample). PARTICIPANTS: The Health and Retirement Study (HRS) includes data on 12,652 Americans aged 50 to 61 in four waves (1992–1998). The Asset and Health Dynamics Among the Oldest Old (AHEAD) survey followed 8,124 community-dwelling people aged 70 years and older in three waves (1993–1998). MEASUREMENTS: The relationships between the primary outcome measure, lower body mobility (ability to walk several blocks and walk up one flight of stairs without difficulty), and smoking, exercise (HRS only), body mass index (BMI), and alcohol use were estimated in bivariate and multivariate analyses. RESULTS: Not smoking was strongly positively related to mobility, and the relative effects were similar in both panels. Among those with impaired mobility at baseline, not smoking was also strongly related to recovery. In the middle aged, there were consistent dose-response relationships between amount smoked and impaired mobility. Fifteen years after quitting, the risk of impaired mobility returned to that of never smokers. There was also a strong dose-response relationship between level of exercise and mobility. Inverted U-shaped relationships with mobility were observed for BMI and alcohol consumption. CONCLUSIONS: The relationships between not smoking and lower body mobility in middle-aged and older Americans are strong and consistent. Interventions aimed at reducing smoking have the potential to preserve mobility and thereby prolong health and independence in later life. J Am Geriatr Soc 50:691–699, 2002.
Structures of the PutA peripheral membrane flavoenzyme reveal a dynamic substrate-channeling tunnel and the quinone-binding site

Proline utilization A (PutA) proteins are bifunctional peripheral membrane flavoenzymes that catalyze the oxidation of l-proline to l-glutamate by the sequential activities of proline dehydrogenase and aldehyde dehydrogenase domains. Located at the inner membrane of Gram-negative bacteria, PutAs play a major role in energy metabolism by coupling the oxidation of proline imported from the environment to the reduction of membrane-associated quinones. Here, we report seven crystal structures of the 1,004-residue PutA from Geobacter sulfurreducens, along with determination of the protein oligomeric state by small-angle X-ray scattering and kinetic characterization of substrate channeling and quinone reduction. The structures reveal an elaborate and dynamic tunnel system featuring a 75-A-long tunnel that links the two active sites and six smaller tunnels that connect the main tunnel to the bulk medium. The locations of these tunnels and their responses to ligand binding and flavin reduction suggest hypotheses about how proline, water, and quinones enter the tunnel system and where l-glutamate exits. Kinetic measurements show that glutamate production from proline occurs without a lag phase, consistent with substrate channeling and implying that the observed tunnel is functionally relevant. Furthermore, the structure of reduced PutA complexed with menadione bisulfite reveals the elusive quinone-binding site. The benzoquinone binds within 4.0 A of the flavin si face, consistent with direct electron transfer. The location of the quinone site implies that the concave surface of the PutA dimer approaches the membrane. Altogether, these results provide insight into how PutAs couple proline oxidation to quinone reduction.
The effects of electrode placement and innervation zone location on the electromyographic amplitude and mean power frequency versus isometric torque relationships for the vastus lateralis muscle.

Abstract The purposes of this investigation were to examine the effects of electrode placement and innervation zone (IZ) location on: (a) the torque-related patterns of responses for absolute and normalized electromyographic (EMG) amplitude and mean power frequency (MPF) and (b) the mean absolute and normalized EMG amplitude and MPF values. In addition, the present study examined the variability between subjects for the location of the IZ for the vastus lateralis (VL). Eight men (mean±SD age=23.0±4.3yr) performed submaximal to maximal isometric muscle actions of the dominant leg extensors. During each muscle action, fifteen channels of bipolar surface EMG signals were detected from the vastus lateralis using a linear electrode array aligned with the long axis of the muscle fibers. The results indicated that there were differences among channels 1–15 for the patterns of responses and mean values for absolute and normalized EMG amplitude and MPF versus isometric torque. Thus, normalized EMG amplitude and MPF values from different individuals cannot be compared if the EMG signals were detected from different locations over the muscle. In addition, absolute and relative (to femur length) estimates of IZ location for the VL resulted in similar inter-subject variability.
Genome-wide linkage scan for prostate cancer susceptibility genes in men with aggressive disease: significant evidence for linkage at chromosome 15q12

Epidemiological and twin studies have consistently demonstrated a strong genetic component to prostate cancer (PCa) susceptibility. To date, numerous linkage studies have been performed to identify chromosomal regions containing PCa susceptibility genes. Unfortunately, results from these studies have failed to form any obvious consensus regarding which regions are most likely to contain genes that may contribute to PCa predisposition. One plausible explanation for the difficulty in mapping susceptibility loci is the existence of considerable heterogeneity in the phenotype of PCa, with significant variation in clinical stage and grade of disease even among family members. To address this issue, we performed a genome-wide linkage scan on 71 informative families with two or more men with aggressive PCa. When only men with aggressive PCa were coded as affected, statistically significant evidence for linkage at chromosome 15q12 was detected (LOD=3.49; genome-wide p=0.005). Furthermore, the evidence for linkage increased when analyses were restricted to Caucasian–American pedigrees (n=65; LOD=4.05) and pedigrees with two confirmed aggressive cases (n=42, LOD=4.76). Interestingly, a 1-LOD support interval about our peak at 15q12 overlaps a region of suggestive linkage, 15q11, identified by a recent linkage study on 1,233 PCa families by the International Consortium for Prostate Cancer Genetics. Using a more rigid definition of PCa in linkage studies will result in a severe reduction in sample sizes available for study, but may ultimately prove to increase statistical power to detect susceptibility genes for this multigenic trait.
Bradykinin B1 antagonists: SAR studies in the 2,3-diaminopyridine series.

SAR study of the biphenyl region of 2,3-diaminopyridine bradykinin B 1 antagonists was investigated with non-aromatic carbo- and heterocyclic rings. A piperidine ring was found to be a good replacement for the proximal phenyl ring while replacement of the distal phenyl was optimal with a cyclohexyl group leading to a dramatic improvement in affinity for the B 1 receptor.
Solitary wave solutions and periodic solutions for higher-order nonlinear evolution equations

The sine-cosine and the tanh methods combined with the homogeneous balance method are used for analytic study for higher-order nonlinear evolution equations. Exact solitary wave solutions and periodic solutions are developed. A comparison between the two used methods is presented.
Two erythropoietic microenvironments and two larval red cell lines in bullfrog tadpoles

Abstract Previous work has shown that Rana catesbeiana tadpoles have two erythropoietic sites: mesonephric kidney and liver. Both sites apparently are active throughout larval life. Among the pleomorphic larval red blood cells (RBCs) we observe two morphological types which differ in the larval hemoglobins (Hb) that they contain. One type is an oblong, oval RBC with an acentric nucleus and contains the larval Hb which is slowest migrating on electrophoresis at basic pH. This RBC type emanates from the kidneys. The other type, which is elliptical in shape, with a central nucleus, contains three other larval Hbs and emanates from the liver. Histological sections of kidney and liver reveal erythropoietic foci of differing cellular composition and configuration. We have hypothesized that choice of RBC and Hb types is determined in part by the different erythropoietic microenvironments. In support of this hypothesis is our finding that, in organ cultures, liver cocultured with kidney undergoes a shift in its Hb pattern. Part of the shift is toward the Hb type which is the product of kidney erythropoiesis.
N,N-dimethyl-selenobenzamide: two solid phases and low-temperature phase change

Abstract Two polymorphs (I: mp 49.0–50.0°C; II: mp 80.0–82.0°C) of N,N-dimethyl-selenobenzamide, (CH3)2NC(Se)Ph, have been observed. Both I and II can be prepared separately using the same reaction under different conditions. The phase change from phase I to phase II occurs at low temperatures and this has been confirmed by solid state NMR (13C), powder X-ray, and single-crystal structural studies. The single-crystal X-ray diffraction study reveals that the lower melting point form (phase I) crystallizes in the triclinic space group P-1 with two conformations in the unit cell, while the higher melting point form (phase II) crystallizes in the monoclinic space group P21/c with one conformation in the unit cell. Theoretical calculations on model clusters using the Universal Forcefield (UFF) show that the total energy of phase I (triclinic form) is 5.9 kcal per mol molecule higher than that of phase II (monoclinic form). Also, the immersion energy which is due to non-bonding interactions, namely Van der Waals and Coulombic (electrostatic) terms, has been calculated using UFF. The Van der Waals terms were very similar in the two crystalline forms (triclinic: −43.1 kcal mol−1; monoclinic: −44.8 kcal mol−1), but the Coulombic terms were significantly different (triclinic: −14.0 kcal mol−1; monoclinic: −31.5 kcal mol−1) and favor the monoclinic form. The triclinic form (phase I) is a kinetically favored metastable phase and upon cooling it changes to the monoclinic form (phase II), a thermodynamically stable phase.
American workplace dispute resolution in the individual rights era

This article presents a theoretical conceptualization of the rise of alternative dispute resolution and its impact on American employment relations in the individual rights era. The idea of an industrial relations system advanced by Dunlop is no longer a plausible general approach for understanding American employment relations given the decline of organized labor. This article examines the question of whether a new individual employment rights-based system of employment relations has replaced it. The old New Deal industrial relations system was based on three pillars: labor contracts that provided a web of rules governing the workplace; economic strikes, actual or threatened, which provided the bargaining power for unions to negotiate these contracts; and labor arbitration, which provided the workplace dispute resolution mechanism for enforcing these contracts. The institutions of the new individual employment rights era can be seen as based on three parallel elements: individual employment rights provid...
ULTRASOUND SCANNING OF SUPERFICIAL STRUCTURES USING AN ULTRASOUND STANDOFF PAD

Complete ultrasonographic visualization of superficial structures is facilitated by using a commercially available ultrasound standoff pad. Normally, scanning of superficial structures is difficult, even when using high-frequency transducers. A major problem is the generation of intense echoes in the most superficial zone of the near field due to transducer reverberations. The ultrasound standoff pad decreases or prevents echo reverberations in the area of interest by placing it in the focal zone of the transducer. The standoff pad has been used to evaluate the flexor tendons of the equine metacarpus and metatarsus, canine testicle, canine lymph node, and other organs in cats and small dogs. Examples of this technique are presented.
Cardiovascular applications of fluorocarbons in regional ischemia/reperfusion.

Potential cardiovascular therapeutic uses for perfluorochemicals include oxygen delivery distal to an occluding balloon during high risk coronary angioplasties, treatment for acute myocardial infarction with or without concomitant reperfusion, cardioplegia, and preservation of donor hearts for transplant. Infusions of oxygenated perfluorochemicals during brief coronary occlusions, as occurs with angioplasties, preserves cardiac ultrastructure and cardiac function. Fluosol is currently approved in the U.S. for angioplasty procedures. Experimental studies have suggested that perfluorochemicals reduce myocardial infarct size during permanent coronary occlusion or temporary coronary occlusion. One school of thought suggests that these agents work by reducing reperfusion injury. By inhibiting neutrophil function, including adherence to endothelial cells and release of toxic substances, perfluorochemicals may preserve the endothelium and prevent no-reflow. However, one might argue that any agent which reduces i...
Factors affecting the exercise capacity of pediatric patients with aortic regurgitation.

Although exercise testing is commonly employed to identify adult aortic regurgitation (AR) patients with early left ventricular (LV) dysfunction, the role and value of exercise testing in the management of pediatric AR patients have not been established. The purposes of this study were to evaluate the cardiorespiratory response to exercise of pediatric patients with chronic AR, examine the relation between exercise function and baseline echocardiographic measurements, and identify factors related to diminished exercise capacity (EC). The study group consisted of 26 patients aged 8 to 21 years (mean 14.4 ± 3.7) with moderate or severe AR referred for exercise physiology testing. All patients underwent a baseline echocardiographic study and a symptom-limited, progressive cycle ergometer exercise test. LV diastolic dimension averaged 120 ± 12% predicted, systolic dimension 112 ± 20% predicted, shortening fraction 0.41 ± 0.07, end-systolic wall stress 65 ± 23 g/cm2, and regurgitant fraction 38 ± 16%. The average EC was 88 ± 28% (56–143) predicted. No statistically significant correlation was found between EC and any of the echocardiographic parameters studied. Nine patients had EC < 75% predicted. These individuals did not differ from patients with higher EC with regard to any of the echocardiographic parameters or with regard to peak heart rate, blood pressure, respiratory exchange ratio, and incidence of ectopy or ST depression. However, the oxygen pulse at peak exercise (an index proportional to forward stroke volume at peak exercise) was significantly depressed among patients with EC < 75% predicted (77 ± 6 vs. 106 ± 16% predicted, p < .0001). In conclusion, most pediatric patients with moderate or severe AR compensate well for their valve disease, maintain normal forward stroke volume during exercise, and have normal EC. However, a subset of AR patients have diminished EC secondary to an inability to augment forward stroke volume appropriately. These patients cannot be identified on the basis of resting echocardiographic studies. Timely identification of these patients, through formal exercise physiology testing, may have important clinical implications.
Development of the nonlinear optical crystal CsTiOAsO4 II. Crystal growth and characterization

Abstract We report here the crystal growth and characterization of the new nonlinear optical crystal CsTiOAsO 4 (CTA). We have studied the Cs 2 O-TiO 2 -As 2 O 5 ternary and identified the phase field within which orthorhombic CTA can be crystallized. Large inclusion-free single crystals measuring up to 30×20×25 mm 3 can be readily grown using the Cs 5 As 3 O 10 self-flux. As grown CTA crystals have the same crystal facets as KTP, although they tend to be multidomain. We present here two techniques for removing these domains: by trivalent oxide dopings and by ferroelectric poling. The refractive indices, nonlinear optical coefficients, electro-optic coefficients and dielectric properties of single domain CTA crystals are reported. Compared to the crystal KTiOPO 4 , the smaller birefringence of CTA makes it particularly suitable for frequency doubling fundamental wavelengths between 1.3 and 1.5 μm. Our results suggest that CTA should find practical applications in electrooptic and in frequency conversion applications, such as optical parametric oscillators and compact diode-pumped solid state lasers.
Temporal variations in diatom abundance and downward vertical flux in the oligotrophic North Pacific gyre

Abstract The abundance of diatoms in the water column and the downward vertical flux of diatom cells from the euphotic zone were investigated during a time series of 11 monthly cruises (June 1994–July 1995) to Station ALOHA (22°45′N, 158°00′W) as one component of the Hawaii Ocean Time-series (HOT) Program. The diatom community was studied using light microscopy and by high-performance liquid chromatographic (HPLC) pigment analyses. Distinct diatom assemblages were found in the mixed-layer and in the Deep Chlorophyll Maximum Layer (DCML). Diatom cell abundances in the water column were generally low during the year, except in July 1994, when they increased in the upper euphotic layer. Two lightly silicified species ( Hemiaulus hauckii [Grunow] and Mastogloia woodiana [Taylor]) were mainly responsible for this increase. Other less abundant diatom species present in the mixed-layer assemblage showed a similar temporal pattern. H. hauckii contained Richelia -type endosymbionts with heterocysts and was presumably able to fix dinitrogen. Both species of diatoms also were an important component of the vertical diatom flux out of the euphotic zone, which, likewise, was highest in July 1994. During this maximum export period, aggregates of these two species were collected in the drifting sediment traps. In the DCML, diatom abundances and export were low throughout the year, with the exception of one genus ( Pseudonitzschia ) for which a slight concentration increase was observed in spring. Reflecting the observed diatom cell abundance and vertical flux, fucoxanthin concentrations (a pigment marker for diatoms) did not indicate any significant increase of diatom pigment biomass in the DCML during the year. Ratios of diadinoxanthin to chromophyte pigments suggested that the phytoplankton cells sinking out of the euphotic zone in midsummer originated from the mixed-layer. The attenuation of the pigment vertical fluxes with depth was significantly lower for fucoxanthin, indicating a generally slower decay of diatom flux with depth compared with other phytoplankton groups. Our findings suggest that, in the subtropical North Pacific Ocean, summer conditions seem to favor the development of selected species of diatoms in the mixed-layer and that these assemblages appear to be more important with regard to export production than those in the DCML.
Analyses of the extent of immunological relatedness between a highly purified pea chloroplast functional RNA polymerase and Escherichia coli RNA polymerase

Summary The reported nucleotide sequence homology between the RNA polymerase (EC 2.7.7.6) coding (rpo) genes in Escherichia coli and their putative homologues in chloroplast DNA is not only limited to about 26-50 %, but also scattered. Utilising the homologous in vitro transcription system and immunological approach, we address as to which extent the chloroplast functional RNA polymerase and E. coli RNA polymerase are related. Highly purified RNA polymerase from pea chloroplasts has been demonstrated to transcribe both ribosomal and messenger RNA genes and the purified homologous antibodies inhibit the chloroplast gene promoter recognizing ability as well as in vitro transcriptional activity of the enzyme [Rajasekhar et al., 1991]. While recognizing all of the polypeptides of the chloroplast enzyme on Western blots, the chloroplast RNA polymerase antibodies did not cross-react with the sub-units of E. coli RNA polymerase or wheat germ RNA polymerase and vice versa. Antibodies against the 130 kDa,110 kDa, 75-95 kDa and 48 kDa polypeptides of the purified chloroplast RNA polymerase immobilized only homologous RNA polymerase on the affinity columns. The active enzyme eluted from the immunoaffinity columns showed sub-unit patterns similar to that of purified RNA polymerase. The specificity of these antibodies was confirmed with the lack of immobilization of E. coli RNA polymerase and vice versa with the E. coli RNA polymerase antibodies. The E. coli RNA polymerase also manifested transcription in vitro utilising the supercoiled 7A/30T recombinant containing the chloroplast 16S rRNA minigene as well as the supercoiled pCB 1-3 recombinant containing the upstream sequences of ribulose-1,5-bisphosphate carboxylase large sub-unit (rbc-L) gene. The transcriptional activities, however, were specifically affected only by homologous RNA polymerase antibodies, but not by heterologous RNA polymerase antibodies. While both the chloroplast and the E. coli RNA polymerases caused mobility shifts of the chloroplast 16S rRNA gene and rbc-L gene promoter fragments, only the homologous antibodies were effective in abolishing this response. The data obtained form the first functional evidence that the highly purified pea chloroplast RNA polymerase and the E. coli RNA polymerase are immunologically only distantly related.
The bliss (not the problem) of motor abundance (not redundancy).

Motor control is an area of natural science exploring how the nervous system interacts with other body parts and the environment to produce purposeful, coordinated actions. A central problem of motor control – the problem of motor redundancy – was formulated by Nikolai Bernstein as the problem of elimination of redundant degrees-of-freedom. Traditionally, this problem has been addressed using optimization methods based on a variety of cost functions. This review draws attention to a body of recent findings suggesting that the problem has been formulated incorrectly. An alternative view has been suggested as the principle of abundance, which considers the apparently redundant degrees-of-freedom as useful and even vital for many aspects of motor behavior. Over the past ten years, dozens of publications have provided support for this view based on the ideas of synergic control, computational apparatus of the uncontrolled manifold hypothesis, and the equilibrium-point (referent configuration) hypothesis. In particular, large amounts of “good variance” – variance in the space of elements that has no effect on the overall performance – have been documented across a variety of natural actions. “Good variance” helps an abundant system to deal with secondary tasks and unexpected perturbations; its amount shows adaptive modulation across a variety of conditions. These data support the view that there is no problem of motor redundancy; there is bliss of motor abundance.
The status of statewide burn prevention legislation.

Successful programs in injury prevention can focus on changing an individual's attitude and behavior or on creating and amending the environment to reduce the likelihood of injury. To investigate the latter approach as it pertains to burn prevention, the American Burn Association Burn Prevention Committee catalogued statewide legislation (as opposted to county or municipal ordinances) in major areas of burn and fire prevention. Burn reporting was generally viewed by state fire marshals as a means to apprehend arsonists or investigate child abuse, as opposed to collect demographic data for injury prevention. Smoke detectors are mandated in new residential construction by the majority of states; however, one in six still leave this to local initiatives. Sprinkler systems have generally not been addressed by state legislation. The committee concludes that pursuing statewide legislative agendas as an area of burn and injury prevention is open to further initiatives. Language: en
On the epistemological significance of the hungarian project

There are three elements in this paper. One is what we shall call ‘the Hungarian project’. This is the collected work of Andreka, Madarasz, Nemeti, Szekely and others. The second is Molinini’s philosophical work on the nature of mathematical explanations in science. The third is my pluralist approach to mathematics. The theses of this paper are that (1) the Hungarian project gives genuine mathematical explanations for physical phenomena. (2) A pluralist account of mathematical explanation can help us with appreciating the significance of the Hungarian project. (3) The significance consists in the fruitfulness and spread of the project. The spread is wide because the explanations are written in the very familiar language of first-order logic with identity. For this reason, the explanation is understandable to many mathematicians. (4) Because of the methodology adopted in the Hungarian project, the explanations are fruitful in another sense. In the Hungarian project certain questions are asked that would not be asked with a more usual methodology. The Hungarians are distinguished from other scientists in asking logical and mathematical questions, and these both deepen our understanding of the physical theories and induce further spread to mathematics and philosophy.
Soluble T lymphocyte markers in the diagnosis of cellular rejection and cytomegalovirus hepatitis in liver transplant recipients.

Hepatic dysfunction following liver transplantation is often caused by cellular rejection or infection with cytomegalovirus. These etiologies can at times be difficult to differentiate. We measured the levels of soluble T lymphocyte markers sIL2R, sCD4, and sCD8 in serum as possible diagnostic indicators of cellular rejection and cytomegalovirus hepatitis. Pretransplant levels, and serial post-transplant levels of soluble T lymphocyte markers were measured in five control patients without cellular rejection or cytomegalovirus infection, ten patients with cellular rejection, and six patients with cytomegalovirus hepatitis. In all cases, cellular rejection and cytomegalovirus hepatitis were documented with liver histology. For each group of patients, we calculated the mean ratio of the post-transplant marker level divided by the pre-transplant level. We found an elevation in the mean ratio of sIL2R in patients with cellular rejection shortly before or at the time of diagnosis of rejection as compared to the transplant control group. Levels of sCD8 were not significantly increased in patients with cellular rejection. We found a more pronounced elevation in the mean marker ratios of both sIL2R and sCD8 in patients with cytomegalovirus hepatitis which were higher compared not only to the transplant control group but also compared to the cellular rejection group. The rise of serum levels preceded the histologic diagnosis of cytomegalovirus hepatitis and detection of cytomegalovirus in blood cultures. Increased serum levels of sIL2R with concomitant elevation of sCD8 suggest the diagnosis of cytomegalovirus hepatitis over cellular rejection. We conclude that serial measurements of sIL2R and sCD8 may be useful to differentiate cytomegalovirus hepatitis from episodes of acute cellular allograft rejection, particularly those rejection episodes occurring late (>20 days posttransplantation).
Postnatal ontogeny of metallothionein in various organs of the rat

Abstract Newborn rats have high levels of hepatic metallothionein (MT) which decrease to adult levels by 1 month of age. However, little is known about MT in other organs during this period. Therefore, this study was designed to estimate the MT concentration of major organs during postnatal development. Various tissues were assayed for MT on Days 1, 7, 14, 21, 28, and 35 postpartum and compared to levels in adult rats. The highest concentration of MT was found in liver of 1-day-old rats followed by testes, kidney, spleen, pancreas, intestine, stomach, lung, and brain. Levels in all organs except brain were 2- to 90-fold higher in 1-day-old than adult rats. Hepatic MT remained high for the first week and then decreased steadily to adult levels by Day 28. Concentrations in spleen, pancreas, and heart fell steadily to adult values by 3 to 4 weeks while lung MT levels declined much more rapidly. Renal MT was highest on Day 14 and then decreased to adult values by Day 28. Levels in intestine and stomach remained constant until decreasing to adult values on Day 28. Neonatal brain had lower MT concentrations than adult brain, increasing to adult levels by Day 21. Testicular MT concentrations were 50% higher than adult concentrations on Day 1, decreased to 40% of adult levels by 1 week, and stabilized at adult levels by 2 weeks of age. Cd treatment (3 mg Cd/kg, iv) of 1-week-old rats elevated MT concentrations in all organs except liver, testes, and brain. Zn treatment (20 mg Zn/kg, iv) increased MT concentrations only in liver, kidney, intestine, pancreas, and spleen. The increase in MT concentration in the pancreas following Zn treatment was the most marked of any organ; levels here increased to approximately 2000% of control. Results indicate that MT levels in most neonatal tissues were higher than in adults and that the postnatal ontogeny of MT is organ specific.
Clinical differentiation of acute necrotizing from chronic nonsuppurative pancreatitis in cats: 63 cases (1996–2001)

Objective—To characterize clinical, clinicopathologic, radiographic, and ultrasonographic findings in cats with histologically confirmed acute necrotizing pancreatitis (ANP) or chronic nonsuppurative pancreatitis (CP) and identify features that may be useful in the antemortem differentiation of these disorders. Design—Retrospective study. Animals—63 cats with histologically confirmed ANP (n = 30) or CP (33). Procedure—Medical records were reviewed for signalment, clinical signs, concurrent diseases, clinicopathologic findings, and results of radiography and ultrasonography. Results—Cats in both groups had similar nonspecific clinical signs, physical examination findings, and radiographic and ultrasonographic abnormalities. Abdominal ultrasonographic abnormalities, including hypoechoic pancreas, hyperechoic mesentery, and abdominal effusion, were found in cats in both groups and, therefore, were not specific for ANP. Cats with CP were significantly more likely to have concurrent diseases than were cats wit...
Twenty years after kernen: The portrayal of African Americans on prime‐time television

In order to document the present‐day portrayal of African Americans on television, a content analysis was conducted on a sample week of all national network commercial television series regularly containing an African American character and aired during prime time in the 1987 fall season. An analysis of both character and program attributes reveals an improvement in the participation and portrayal of African Americans since the publication of the Kerner Commission Report, with African Americans portrayed in a diversity of dramatic and comedie roles and settings. Yet, the casting of African American characters generally remains governed by many of the dominant myths about preferred social roles for African Americans, with African Americans being more frequently portrayed in all‐black, comical settings.
Infrared Laser Photolysis Of Polyatomic Molecules: A Powerful Technique For Studying Elementary Processes In The Gas Phase

The infrared photolysis of polyatomic molecules is discussed. Several examples are presented, with products being detected either by chemiluminescence or by laser-induced fluorescence. The technique allows a study both of the dynamics of unimolecular decomposition and of the reaction kinetics and dynamics of the resulting free radicals. Information on the former is deduced from such features as product energy partitioning, product yield as a function of incident laser fluence, and the effect of collisions on the degree and rate of the dissociation. The latter aspect of the technique is powerfully illustrated by the reactions of C2 (X,a) radicals (produced by photolysis of several organic molecules) with such gases as 02 and NO, from which chemiluminescent reaction products have been detected.