cssi/SciSciGPT-SciSciNet huggingface dataset:
Controlling the structure and rheology of polyimide/nanoclay composites by condensation polymerization

A novel in situ condensation polymerization method for controlling the structure and dispersion of clay in the polyimide (PI) matrix has been investigated. Initially, the viscosity of the polymerizing poly(amic acid) (PAA) solution increases rapidly with increasing shear rate and polymerization time. In the presence of clay, the PAA solution viscosity became significantly higher than that for the neat PAA solution at initial polymerization stage; however, it attained a final value, which was significantly lower than that for a neat PAA solution after a long polymerization time. The PAA/clay solution synthesized by in situ polycondensation reaction also showed an interesting optical activity between 500 and 600 nm. The PAA/clay solution prepared by a two-step method involving polymerization followed by the addition of clay shows no unusual optical behavior above 400 nm. The imidization of PAA is enhanced in the presence of clay. The imidization temperature decreased significantly in the presence of clay, and the extent of imidization increased with increasing amount of clay and cure temperature. X-ray diffraction and microscopy studies show the existence of exfoliated clays at low concentration of clay and at high curing temperatures. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Distinction between a perfect conductor and a superconductor

A comment is presented on the claim that Meissner effect occurs not only in superconductors, but also in perfect conductors detrmined by classical mechanics.
Penetration glands in the onchospheres of Raillietina cesticillus.

Abstract 1. (1) Onchospheres of Raillietina cesticillus stained with brilliant cresyl blue have been hatched in 0.135 M KCl, and the dynamic morphology of Reid's penetration glands during the hatching was demonstrated. 2. (2) The penetration glands of Raillietina cesticillus are U-shaped pouches. Each pair of secretory canals, which starts from two penetration glands, one on either side of the organism, opens to four secretory pores at the hook-bearing end of the onchosphere. 3. (3) The glandular secretion which is discharged from the four secretory pores is helpful in the process of penetrating the larval membranes. 4. (4) The glandular secretion shows a positive staining reaction with the PAS technique indicating that the glandular secretion contains polysaccharide complexes. 5. (5) The glandular secretion is spent while the onchosphere penetrates the digestive mucosa of the intermediate host and gets out into the hemocoel. The glandular secretion is, therefore, shown to play an active part in the penetration of the onchosphere into the digestive mucosa of the intermediate host.
Fasciola hepatica: development of the tegument of normal and gamma-irradiated flukes during infection in rats and mice.

Rats and mice were infected with either normal metacercariae or metacercariae gamma-irradiated at 3 krad. or 4 krad. Flukes were recovered at various times after infection and their teguments examined using a transmission electron microscope. In normal flukes, the secretory granules T0, T1 and T2 were all seen during tegumental development. The teguments of flukes from mice developed faster than the corresponding teguments in rats. T0 granules were present from day 0 to day 10 post-infection (p.i.) in mouse flukes and from day 0 to day 14 p.i. in rat flukes. T1 granules first appeared in mouse flukes by day 4 p.i. but not until day 8 p.i. in rat flukes. T2 granules were seen in mouse flukes 2 days p.i. but not before 6 days p.i. in rat flukes. gamma-Irradiation at 4 krad prevented normal tegumental development in flukes from both rats and mice. T0 granules were present at all times in flukes from either host. T1 granules were produced in mouse flukes but their appearance was delayed until day 6 p.i. No significant production of T2 granules occurred in flukes from either host. Parasite survival was also affected by gamma-irradiation and none of the flukes reached maturity. Flukes from rats died between 10 and 21 days p.i. and flukes from mice died between 14 and 28 days p.i. gamma-Irradiation of metacercariae at 3 krad. had an extremely variable effect on subsequent tegumental development in both rats and mice. Some flukes developed normally, some showed development associated with gamma-irradiation at 4 krad, whilst some showed intermediate development.
Stochastic Model of the Potential Spread of Highly Pathogenic Avian Influenza from an Infected Commercial Broiler Operation in Georgia

The potential spread of highly pathogenic avian influenza among commercial broiler farms in Georgia, U. S. A., was mathematically modeled. The dynamics of the spread within the first infected flock were estimated using an SEIR (susceptible-exposed-infectious-recovered) deterministic model, and predicted that grower detection of flock infection is most likely 5 days after virus introduction. Off-farm spread of virus was estimated stochastically for this period, predicting a mean range of exposed farms from 0-5, depending on the density of farms in the area. Modeled off-farm spread was most frequently associated with feed trucks (highest daily probability and number of farm visits) and with company personnel or hired help (highest level of bird contact).
Control of ribosome-inactivating protein (RIP) RNA levels during maize seed development

Abstract The maize RIP1 gene encodes proRIP, the zymogen form of a ribosome-inactivating protein that accumulates to high levels in endosperm. ProRIP is synthesized coordinately with the major storage proteins and requires a functional allele of the transcriptional activator, Opaque-2 (O2)3 for maximal accumulation. RIP1 gene expression was characterized by developmental RNA gel blot analysis. RIP1 RNA was first detected at 10 days after pollination (DAP), and increased in abundance to reach maximal levels at mid-maturation of the kernel. In four W64A maize lines with independently-derived opaque-2 (o2) alleles, RIP1 RNA still accumulated in a developmentally specific pattern, but showed qualitative and quantitative changes from normal. RNA gel blots reprobed with an O2-specific probe provided evidence for coordinate accumulation of RIP1 and O2 RNAs throughout normal kernel development. The pleiotropic endosperm mutations brittle-1 (bt1), brittle-2 (bt2), shrunken-2 (sh2), sugary-2 (su2), Mucronate (Mc), Defective endosperm-B30 (De∗-B30), and floury-2 (fl2), affected RIP1 and O2 RNA accumulation to varying degrees. None of these mutations, however, resulted in RIP1 RNA reductions comparable to that seen in W64Ao2. When coupled with o2, bt1 and bt2 mutations showed synergistic interactions in their effects of reducing RIP1 RNA levels. Thus, RIP1 gene expression and relative RNA levels are controlled by multiple factors including O2, and o2-independent component(s), genetic background, and the presence of other pleiotropic mutations.
Wave-orientated processing of scattering data

Windowded transforms applied to scattering data gathered along an elevated track parallel to a scattering surface are shown to provide local plane wave spectra which can be backpropagated to synthesise distinct features of the scattering environment. The method is illustrated for plane wave scattering from a truncated array of pitched strips
Computed tomography-guided neurolytic celiac plexus block with alcohol complicated by superior mesenteric venous thrombosis

Neurolytic celiac plexus block (CPB) under radiological guidance is often performed to manage pain associated with pancreatic cancer. Serious complications related to the block are rare. Computed Tomography (CT)-guided neurolytic CPB is advocated to improve the efficacy of the block and to reduce the incidence of associated complications. We describe a case of superior mesenteric vein thrombosis associated with neurolytic CPB performed under CT guidance.
Effect of Sex‐Linked Vocational Information on Reported Occupational Choices of High School Juniors

Information about new occupational opportunities for women was read by 144 high school juniors, while 106 other juniors read information about opportunities in general. All students subsequently selected occupations from a list of 40 occupations that would be “most appropriate” for each of five male and five female students described in mock profiles. Two forms of profiles were used, differing only in gender designated for each student description. Differences were found in the “status” of occupations chosen for boy profiles versus girl profiles, based on the median amount of education and annual earnings of people having these occupations, with boys consistently receiving higher level occupations than girls. A three-way analysis of variance indicated that the difference between occupational status scores given to boys arid girls was significantly less in the group receiving information about opportunities for women (p < .01). It was suggested that it may be appropriate to consider vocational information ...
Phytotoxic effects of cadmium in leaf segments ofAvena sativa L., and the protective role of calcium

It is shown that ethylene production can be stimulated in peeled oat leaf segments in the dark by cadmiun at concentrations below 0.01 mM, and that cadmium-stimulated stress ethylene accelerates senescence processes. Higher cadmium concentrations cause membrane deterioration and inhibit ethylene production and senescence. These effects of cadmium are antagonized by calcium. This indicates a possible protection of plant cell against cadmium toxicity by calcium.
Chronic Morphine Treatment Reduces Recovery from Opioid Desensitization

Tolerance and dependence result from long-term exposure to opioids, and there is growing evidence linking acute receptor desensitization to these more long-term processes. Receptor desensitization encompasses a series of events leading to the loss of receptor function and internalization. This study examines the onset and recovery from desensitization in locus ceruleus neurons recorded in brain slices taken from animals that have been chronically treated with morphine. After chronic morphine treatment, desensitization was altered as follows. First, the rate of desensitization was increased. Second, recovery from desensitization was always incomplete, even after a brief (1-2 min) exposure to agonist. This contrasts with experiments in controls in which recovery from desensitization, after a brief exposure to agonist, was complete within 25 min. Finally, morphine-6-β-d-glucuronide, a metabolite of morphine that was ineffective at causing desensitization in controls, induced significant desensitization in slices from morphine-treated animals. When brain slices from controls were treated with inhibitors of PKC or monensin, agents known to compromise G-protein-coupled receptor resensitization, desensitization was increased, and recovery was significantly reduced. These results indicate that receptor resensitization maintains signaling during periods of intense and sustained stimulation. After chronic morphine treatment, desensitization is potentiated, and receptor resensitization is compromised.
CS1 and CS2: write computer games in Java!

The authors have designed an introductory sequence of programming courses. In order to keep the students interested and to add some fun to the course, all the programming assignments involve implementing computer games as Java applets. The entire course (including syllabus, assignments, and working source code) is available for download from the authors' web site.
On Mechanisms of Fatigue Life Enhancement by Surface Dents in Heavily Loaded Rolling Line Contacts

This paper studies mechanisms of surface dents in enhancing the fatigue life of rolling bearings previously reported in Akamatsu et al. (1). First, transient micro-EHL analyses of heavily loaded contacts between rough surfaces with multiple dents are conducted under near rolling conditions. Contacts with various dent dimensions, dent arrangements under different loading and kinematic conditions are investigated. Results show that surface dents generate no favorable micro-EHL effects to enhance the contact fatigue life. Subsequent analyses, in conjunction with other published studies, suggest that the fatigue life enhancement likely comes from the reduced local traction at asperity contacts through the “oil pots” effects of the dents. The effects of the surface dents on contact fatigue life may depend on the lubrication regime in which the contact is operating being favorable in poor lubrication conditions but adverse in well-lubricated contacts. Since rolling bearings are usually designed to operate in a ...
Particle induced desorption and the analysis of large molecules

Abstract This opening lecture in the Texas Symposium on Particle Induced Desorption is intended to reflect on the state of the art, and to pose questions to the instrumentalists, the theoreticians and the analytical/bioorganic chemists participating in the three respective subdivisions of the symposium. Recent studies from our laboratory are discussed which investigate the information which can be deduced from the molecular ion envelope of an unknown middle mass or large molecule, evaluate the need for unit resolution above 5000 amu, and illustrate the ability of particle induced desorption to provide stable isotope analyses, absolute and relative quantitation in mixtures, as well as molecular weights and structural information.
Multiscale Characteristics and Evolution of Perturbations for Warm Season Convection-Allowing Precipitation Forecasts: Dependence on Background Flow and Method of Perturbation

AbstractMultiscale convection-allowing precipitation forecast perturbations are examined for two forecasts and systematically over 34 forecasts out to 30-h lead time using Haar Wavelet decomposition. Two small-scale initial condition (IC) perturbation methods are compared to the larger-scale IC and physics perturbations in an experimental convection-allowing ensemble. For a precipitation forecast driven primarily by a synoptic-scale baroclinic disturbance, small-scale IC perturbations resulted in little precipitation forecast perturbation energy on medium and large scales, compared to larger-scale IC and physics (LGPH) perturbations after the first few forecast hours. However, for a case where forecast convection at the initial time grew upscale into a mesoscale convective system (MCS), small-scale IC and LGPH perturbations resulted in similar forecast perturbation energy on all scales after about 12 h. Small-scale IC perturbations added to LGPH increased total forecast perturbation energy for this case. ...
Cost-effectiveness of fingolimod versus interferon beta-1a for relapsing remitting multiple sclerosis in the United States

AbstractObjective:Fingolimod has been shown to be more efficacious than interferon (IFN) beta-1a, but at a higher drug acquisition cost. The aim of this study was to assess the cost-effectiveness of fingolimod compared to IFN beta-1a in patients diagnosed with relapsing-remitting multiple sclerosis (RRMS) in the US.Methods:A Markov model comparing fingolimod to intramuscular IFN beta-1a using a US societal perspective and a 10-year time horizon was developed. A cohort of 37-year-old patients with RRMS and a Kurtzke Expanded Disability Status Scale score of 0–2.5 were assumed. Data sources included the Trial Assessing Injectable Interferon vs FTY720 Oral in Relapsing–Remitting Multiple Sclerosis (TRANSFORMS) and other published studies of MS. Outcomes included costs in 2011 US dollars, quality-adjusted life years (QALYs), number of relapses avoided, and incremental cost-effectiveness ratios (ICERs).Results:Compared to IFN beta-1a, fingolimod was associated with fewer relapses (0.41 vs 0.73 per patient per ...
The Effect of Long-term Hypoxia on Tension and Intracellular Calcium Responses Following Stimulation of the Thromboxane A2 Receptor in the Left Anterior Descending Coronary Artery of Fetal Sheep

Objective: The purpose of this study was to investigate the mechanisms of tension and intracellular calcium regulation following stimulation with the thromboxane A2 receptor agonist U46619 in the left anterior descending coronary artery of fetal sheep exposed to long-term hypoxia. We hypothesized that there would be a reduction in intracellular calcium responses in long-term hypoxic left anterior descending coronary artery accompanied by an increase in calcium sensitivity of the contractile mechanism. Methods: Pregnant sheep were kept at altitude (3820 m) from day 30 of gestation until day 140. Fetal hearts from long-term hypoxic and from a control, normoxic group were obtained and the left anterior descending coronary artery of the fetus was dissected, cleaned, and mounted in a bath (Jasco) in which tension and intracellular calcium [Ca2+]i, using Fura-2, could be measured simultaneously following stimulation of the thromboxane A2 receptor with U46619. The role of intracellular calcium and the Rho kinase...
Adolescent Females and Their Mothers Examining Perceptions of the Environment and Breast Cancer

Recent research indicates environmental factors and personal behaviors are related to breast cancer risk, but adopting a healthy lifestyle as early as adolescence can serve a protective function. To investigate perceptions of breast cancer risk and the environment, 10 focus groups (N = 91) were conducted with adolescent females (n = 55) and mothers (n = 36) across four counties in the Midwest, USA. The Uncertainty Management Theory provides a framework for discussing statements, and results suggest that uncertainty is maintained through ambiguity about environmental risk factors and breast cancer. Recommendations for prevention messages are presented.
Cell Immortality and Hallmarks of Cancer

In growth-limiting conditions, cells that express telomerase and inactivate tumor suppressors have a selective advantage due to resistance to growth arrest. Accidentally such cells become immortal.
Calculation of the cumulative reaction probability via a discrete variable representation with absorbing boundary conditions

A new method is suggested for the calculation of the microcanonical cumulative reaction probability via flux autocorrelation relations. The Hamiltonian and the flux operators are computed in a discrete variable representation (DVR) and a well‐behaved representation for the Green’s operator, G(E+), is obtained by imposing absorbing boundary conditions (ABC). Applications to a one‐dimensional‐model problem and to the collinear H+H2 reaction show that the DVR‐ABC scheme provides a very efficient method for the direct calculation of the microcanonical probability, circumventing the need to compute the state‐to‐state dynamics. Our results indicate that the cumulative reaction probability can be calculated to a high accuracy using a rather small number of DVR points, confined to the vicinity of the transition state. Only limited information regarding the potential‐energy surface is therefore required, suggesting that this method would be applicable also to higher dimensionality problems, for which the complete potential surface is often unknown.
Staging or classification of Alzheimer's disease/early Alzheimer's disease: Epidemiological perspective

Background: In clinical specialist / clinical research settings, patients / study participants are typically individuals seeking care for difficulties with memory and other cognitive problems, subjectively identified, then test objectively and hen examined by expert clinicians who diagnose and classify or stage disease. But most individuals with AD are not seen by memory specialists. In the primary care setting, patients with AD may not complain of cognitive problems, thus the deficits may remain undetected unless the clinician identifies them during the course of the examination, or screens for them routinely. In epidemiologic studies at the community (population) level , large numbers of individuals are tested objectively without regard to subjective complaints. They do not all have reliable informants, and can not all be examined by expert clinicians. This situation provides unique methodological challenges for staging and classification of AD, particularly early AD at the Population level. It can have substantial impact on estimation of prevalence and incidence, and potentially on identification of risk and protective factors. Methods: Review of the literature on detection and classification of AD and early AD (at the ‘‘mild cognitive impairment’’ stage before the ‘‘dementia’’ threshold is crossed) in population and primary care studies, and of relevant practice guidelines. Results: Classification neuropsychological approaches range from purely functional to purely to combinations of the two, with varying emphases on subjective complaints and clinical judgment, and with different thresholds applied for Designating individuals as impaired or demented. Prevalence estimates vary widely and depend in large part on the criteria used and the manner in which they are operationalized. A few studies also compare different classifications on their outcomes over time. A key issue is the availability of appropriate norms for the population under study. The majority of population studies have not used biomarkers for classification. Conclusions: Progress has been made in Adapting classification and staging approaches, initially developed for specialist clinical settings, for application in non-specialist and population settings. Key remaining challenges include the establishment of reliable, sensitive, and specific criteria with good predictive validity, publication of good normative data and thresholds, cost-effective large-scale assessment methods, and the judicious inclusion of appropriate biomarkers.
Thieme E-Book Library Review

With seventy-three full-text, illustrated clinical and science books in the collection, the Thieme E-Book Library is an e-book platform that medical librarians in the academic setting may want to consider. This review explores the content, access, browsing, and searching capabilities, and functionality of the Thieme E-Book Library.
Prevention and Treatment of Urinary Catheter-Associated Infections

Catheter-associated urinary tract infections (CA-UTIs) are the most common nosocomial infection worldwide. Prolonged catheterization is the most important risk factor for CA-UTIs. As is the case with all device-related infections, the biofilm plays a central role in the pathogenesis of CA-UTIs. The diagnosis is often difficult, given the lack of good diagnostic tests. The most effective way to prevent infection is to limit catheter use and discontinue the catheter when no longer needed. Catheter removal or exchange is also useful in management. This review summarizes and analyzes the results of published studies of CA-UTIs and assesses the role of prevention approaches and management strategies.
Automated Occupant Model Evaluation and Correlation

Rapid advance in computational power and modeling techniques has greatly promoted the application of computer simulations of physical systems in various areas. In the vehicle occupant safety design and analysis, computer models have been widely used to simulate vehicle interior, restraint system and occupants under different crash conditions. However, to ensure the quality of an occupant model engineers often spend tremendous time on model correlation task, especially when correlating multiple occupant injury curves, as in New Car Assessment Program (NCAP), head injury, Chest G, chest deflection, shoulder belt load, femur loads and neck loads and moment etc. all need to be considered. A commonly used approach for model correlation is visual model evaluation and manual model correlation by a trial and error method. This paper develops an automated model correlation program through multiobjective optimization, which is able to achieve a balanced model quality improvement for the multiple responses simultaneously. The developed method has been applied to a real MADYMO model and the results have demonstrated the proposed method is effective and efficient in achieving a high quality occupant model.Copyright © 2005 by ASME
What the Hacks Say: The Ideological Prism of US Journalism Texts

A review of United States journalism textbooks, published during the 1980s and 1990s, suggests that authors focus on essential new information and highlight a cutting edge understanding of new technologies, visual literacy, and/or cultural diversity in an effort to justify publishing new books on the practice of journalism. This review also suggests that while the vast majority of these texts clearly cover the field in a competent and thorough manner, there is a considerable amount of overlapping, repetitive information and that all of these books address the practice of journalism from an identical ideological perspective.
Whither catheter-based intravascular magnetic resonance imaging of atherosclerosis?

A great deal of hype and excitement accompanied the advent of catheter-based magnetic resonance imaging (MRI) of the vessel wall at the end of the 1990s. Initial studies were performed in the vessels ex vivo that demonstrated excellent correlation with histological characteristics of the imaged
Shaping Knowledge about American Labor: External Advising at the U.S. Bureau of Labor Statistics in the Twentieth Century

Created in 1884, the U.S. Bureau of Labor Statistics (BLS) has been the major federal source for data in the United States on labor-related topics such as prices, unemployment, compensation, productivity, and family expenditures. This essay traces the development and transformation of formal and informal consulting relationships between the BLS and external groups (including academic social scientists, unions, businesses, and other government entities) over the twentieth century. Though such a history cannot, of course, provide a comprehensive analysis of how political values have shaped the construction of labor statistics during this period, I argue that it can nevertheless provide important insights into the political context for the construction of knowledge about American workers and their living and working conditions.
Metabolism, temperature relations, maternal behavior, and reproductive energetics in the ball python (Python regius)

Thermogenic incubation has been documented in two large species of pythons, but the phenomenon has not been studied in small species with concomitantly large heat transfer coefficients. We describe behavior, metabolic rates, mass changes, and temperature relations for adult ball pythons (Python regius), the smallest member of the genus, during the reproductive cycle. Egg and hatchling metabolism and hatchling growth rates were also examined. Rates of oxygen consumption ( $$\dot V_{O_2 } $$ ) of both gravid and non-gravid snakes showed typical ectothermic responses to changing ambient temperature (T a). TheQ 10 forT a's of 20–35°C was 2.2–2.3. The $$\dot V_{O_2 } $$ of gravid females was significantly greater than that of non-gravid snakes at allT a. Maximum oxygen consumption ( $$\dot V_{O_2 } $$ max) during forced exercise was about 12 times resting $$\dot V_{O_2 } $$ atT a=30°C. Eggs (5–6 per female) were laid in April. Total clutch mass was approximately 32% of the females' pre-oviposition mass. After oviposition, mother snakes coiled tightly around their clutches and remained in close attendance until the eggs hatched in June. Sudden decreases inT a elicited abrupt but transient 2- to 4-fold increases in the $$\dot V_{O_2 } $$ of incubating females. Similar responses were not observed in non-incubating snakes. The steady-state $$\dot V_{O_2 } $$ of incubating females was independent ofT a. In no case was body temperature (T b) elevated more than a few tenths of a degree aboveT a in steady-state conditions. The $$\dot V_{O_2 } $$ of developing eggs increased sigmoidally through the 58–70 day incubation period. Total oxygen consumption during incubation atT a=29.2°C was about 3.61 per egg. Young snakes quadrupled their mass during their first year of growth. Compared to larger python species which are endothermic during incubation, ball pythons have similar aerobic scopes and higher mass-specific $$\dot V_{O_2 } $$ max. However, effective endothermy in ball pythons is precluded by high thermal conductance and limited energy stores.
Nonviolent Theory on Communication: The Implications for Theorizing a Nonviolent Rhetoric

The interrelationship between nonviolence and rhetoric is examined. While we have studied the world of adversarial relationships, conflict, and difference of belief, rhetorical critics have not done as much to understand the practices of seeking mutual identification, cooperation, and learning how to live with diversity and adversity. Scholars and theorists of nonviolence (and peace and conflict studies) maintain that human beings can reach mutual understanding peacefully, through a process of nonviolent conversion that is accomplished through a wide range of linguistic and symbolic acts. Nonviolent theory shows rhetoricians that language and culture—our ways of creating and perpetuating our reality—can impose minimal aggression while maximizing the potential for peacemaking. Finally, the essay presents practical applications for a better understanding of the connection between rhetorical theory and nonviolence.
FUEL CONSERVATION FOR HIGH PERFORMANCE AIRCRAFT IN THE TERMINAL AREA

In a high density terminal area, speed control and radar vectoring are typically used to optimize the sequence and assure the spacing of landing aircraft for maximum runway utilization. Fuel conservative descent and landing approaches tend to offer reduced control capability to the extent that they depend upon relatively inflexible paths and rigid speed profiles. Under high traffic demands the loss in terminal controllability could adversely impact both airport capacity and fuel consumption through increased delays. This paper describes an approach for the ATC system in the terminal area to accommodate fuel conserving landing approaches. Analytical results are presented that illustrate the impact of fuel economic design on terminal controllability and airport capacity. Peak hour trade–offs between conserving fuel and maximizing runway utilization are also included in the paper. An analytical fuel consumption model is used to estimate the fuel benefits of lifting the 250 knots speed restriction below 10,000 ft. MSL, for both arrivals and departures.
Warren Buffett, Black–Scholes, and the Valuation of Long-Dated Options

In his 2008 letter to Berkshire shareholders, Warren Buffett presented a critique of the Black–Scholes option pricing model as a tool for valuing long-dated options, including options that Berkshire had written. Given Mr. Buffett’s track record, it is worth investigating precisely why he thinks the Black–Scholes model fails to provide a fair value for long-dated options. The alleged deficiencies in the model are, unfortunately, not transparent, because Mr. Buffett’s letter does not develop his viewpoint in terms of option pricing theory. In this article, Cornell fills the gap by interpreting Mr. Buffett’s argument in the context of option pricing theory and reveals that Mr. Buffett is really making a statement about political economics more than about option pricing.
Sex Roles, Friendship, and the Life Course

A review of the research on aging and friendship reveals distinct patterns by gender that are linked to sex role learning and expectations. Friendship behaviors that are adaptive at one part of the...
Characteristics of physicians who frequently see pharmaceutical sales representatives

Pharmaceutical sales representatives (PSRs) can impact physician prescribing. The objective of this study was to test a model of physician and practice setting characteristics as influences on decisions by physicians to see PSRs. A survey was sent to a random sample of 2000 physicians. Multiple linear regression analyses were used to test models for predicting influences on decisions to see PSRs frequently, defined as at least monthly. Independent variables included: presence of restrictive policy for pharmaceutical detailing, volume of prescriptions, gender, age, type of specialty, academic affiliation, practice setting size, and urban versus rural. The dependent variable was frequency of PSRs visits to physicians. Six hundred seventy-one responses were received yielding a response rate of 34.7%. Four hundred thirty-two physicians (79.5%) reported seeing PSRs at least monthly. The decision influence model was found to be significant. Primary care physicians and high-volume prescribers showed increased likelihood to see PSRs. Physicians practicing in settings that were small, urban, without restrictive policies for pharmaceutical detailing, and not academically affiliated were more likely to see PSRs frequently. This model of physician and practice characteristics is useful in explaining the variations in physicians' characteristics who see PSRs frequently. These characteristics could be used to guide the development of future academic or counter-detailing initiatives to improve evidence-based prescribing.
On the order of the phase transition in three-dimensionalSU(N)⊗SU(N) and U(N)⊗U(N) Heisenberg models and finite temperature QCD

Abstract The finite temperature QCD chiral phase transition for massless SU(2), SU(3), U(2), and U(3) flavor groups is studied using the chiral Heisenberg model. A variety of numerical techniques, including metastability analysis, reduced cumulant of the energy, and finite size scaling were employed to determine the order of the finite temperature chiral phase transition for these flavor symmetries. The SU(2) Heisenberg model had a second order transition while the SU(3), U(2) and U(3) models were first order transitions.
Emergency center arteriography in the evaluation of suspected peripheral vascular injuries in children

Abstract During the 6-year period from 1983 to 1989, 109 children aged 3 to 18 years (mean, 16) with suspected peripheral vascular injuries underwent 113 emergency center arteriograms (ECA) performed by hand injection of contrast material using a single roentgenographic film. The most common indication for ECA was the proximity of the injury in 93 (82.3%) of the cases as penetrating injury accounted for 106 (94%) of the cases. There were 89 true-negative, 14 truepositive, 1 false-negative, and no false-positive arteriograms. The remaining 9 arteriograms were either equivocal or technically inadequate. The sensitivity, specificity, and diagnostic accuracy of this procedure were 98.9%, 100%, and 91.2%, respectively. Operative intervention was required for 9 (64.2%) injuries detected by emergency arteriography. The remaining 5 injuries were considered minor and were observed with no complications during a period of 21 months. Sixty-eight children (76.4%) with negative ECA were followed for a mean of 12 months with no vascular complications or growth abnormalities noted. ECA is a rapid, accurate, and cost-effective technique. It is of particular value in detecting the presence of occult arterial injuries that might have deleterious effects in the growing child.
Undifferentiated Connective Tissue Disease-Associated Interstitial Lung Disease: Changes in Lung Function

Undifferentiated connective tissue disease (UCTD) is a distinct clinical entity that may be accompanied by interstitial lung disease (ILD). The natural history of UCTD-ILD is unknown. We hypothesized that patients with UCTD-ILD would be more likely to have improvement in lung function than those with idiopathic pulmonary fibrosis (IPF) during longitudinal follow-up. We identified subjects enrolled in the UCSF ILD cohort study with a diagnosis of IPF or UCTD. The primary outcome compared the presence or absence of a ≥5% increase in percent predicted forced vital capacity (FVC) in IPF and UCTD. Regression models were used to account for potential confounding variables. Ninety subjects were identified; 59 subjects (30 IPF, 29 UCTD) had longitudinal pulmonary function data for inclusion in the analysis. After accounting for baseline pulmonary function tests, treatment, and duration between studies, UCTD was associated with substantial improvement in FVC (odds ratio = 8.23, 95% confidence interval, 1.27–53.2; p = 0.03) during follow-up (median, 8 months) compared with IPF. Patients with UCTD-ILD are more likely to have improved pulmonary function during follow-up than those with IPF. These findings demonstrate the clinical importance of identifying UCTD in patients presenting with an “idiopathic” interstitial pneumonia.
DTI-based three-dimensional tractography detects differences in the pyramidal tracts of infants and children with congenital hemiparesis.

Purpose To test the hypothesis that there is greater asymmetry in diffusion properties between right and left pyramidal tracts in patients with congenital hemiparesis than in patients with normal motor function. Materials and Methods Four congenitally hemiparetic patients and four age-matched controls underwent magnetic resonance diffusion tensor imaging (DTI)-based three-dimensional tractography of the pyramidal tracts. Relative anisotropy, individual eigenvalues, and directionally averaged apparent diffusion coefficient were measured and degree of asymmetry was calculated. Results Compared with age-matched controls, congenitally hemiparetic patients had greater asymmetry in all measured diffusion properties. The asymmetry was characterized primarily by lower anisotropy, lower parallel diffusion, higher transverse diffusion, and slightly higher mean diffusivity in the pyramidal tract contralateral to the hemiparesis (i.e., affected pyramidal tract) compared with the unaffected pyramidal tract. Conclusions There appears to be greater diffusion asymmetry between the pyramidal tracts in congenitally hemiparetic patients compared to controls. These differences suggest that there are alterations in the microstructure of the pyramidal tract that controls the motor function of the hemiparetic side. Our results suggest that DTI-based three-dimensional tractography is potentially useful in the assessment of motor dysfunction in infants and children with congenital hemiparesis. J. Magn. Reson. Imaging 2003;18:641–648. © 2003 Wiley-Liss, Inc.
The behavior of high-energy neutron pairing strength in the samarium isotopes

Abstract The (p, t) reaction has been used to study the behavior of two-neutron holes in the even Sm isotopes at high excitation energy. Both broad and narrow structures are observed at excitation energies above 5 MeV. Some of these can be interpreted in terms of the low-energy structure of 142 Sm.
Elastic fields of line defects in a cracked body

Abstract Elastic fields are presented for line forces and dislocations in the vicinity of a crack tip and of a contained, double-ended planar crack. The fields of line force couples are also derived. The corresponding stress intensity factors are listed. The use of these results as two-dimensional Green functions for more general cases is discussed.
Long-term prospective study in children after respiratory syncytial virus infection

We have prospectively evaluated for the past 8 years 29 children who were hospitalized during infancy with acute lower respiratory tract illness caused by respiratory syncytial virus (RSV). No differences in the prevalence of a family history of atopy or breast-feeding in these infants compared with controls were noted. However, a history of parental smoking was significantly associated with hispital admission for RSV lower respiratory tract disease. Evidence of atopy, as defined by serum IgE levels and radioallergosorbent testing, have developed in only three (10%) of 29 children. Six children (21%) continue to have recurrent lower respiratory tract disease. Fifty-five percent of these children had abnormally low oxyhemoglobin levels (Sao 2 ) measured by ear oximetry for the first 3 to 4 years after the acute illness. Twenty-one percent have persistently low Sao 2 levels during the eighth year of follow-up. Spirometric values indicate evidence of peripheral airway obstruction. These studies suggest that an association between RSV lower respiratory tract infections and chronic abnormalities of pulmonary function may be detected sequentially through the first 8 years of life. These abnormalities are not limited to those children developing an atopic state during that same time period.
Stability of the WAIS-R and WISC-III factor structure using cross-validation of covariance structures

The stability of the Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility factors of the WAIS-R and WISC-III was tested using cross-validation of covariance structure models, a methodology that employs unrestricted and restricted factor analyses. Stability was indicated if the goodness of fit of restricted models generated from unrestricted factor patterns did not degrade when applied to other age groups. If goodness of fit degraded inconsistently, the factor structure of one or both instruments was unreliable. If goodness of fit changed in some systematic fashion, an argument for true intellectual changes could be made. Results indicated consistency across age groups. Therefore, it was concluded that the three-factor structure is robust and reliable across age groups and instruments.
“Quilty” revisited: A 10-year perspective

The goals of this study were to better define Quilty lesions, facilitating differentiation from other endocardial infiltrates; to correlate Quilty lesions with clinical parameters; and to assess whether classification into Quilty A (noninvasive lesions) and Quilty B (invasive lesions) had clinical utility. Two hundred seventeen adults who received transplants between 1981 and 1987 and 22 children who received transplants between 1981 and 1989 were studied. Allograft survival for over 1 year was the selection criterion. Clinical, angiographic, and biopsy data were reviewed up to 1992, obtaining a minimum follow up of 5 years for adults and 3 years for children. All 7,439 endomyocardial biopsy cases were allotted an International Society for Heart and Lung Transplantation (ISHLT) grade for rejection, and Quilty was classified as Quilty A or B. Quilty was correlated with transplant recipient age and gender, cytomegalovirus and Epstein-Barr virus (EBV) infection, treatment protocols, allograft rejection, graft vascular disease (GVD), and lymphoma. Immunohistochemistry was performed to determine Quilty cell composition. Quilty incidence was 49.77% in adults and 68.18% in children, and did not appear to be influenced by cyclosporine dosage. Quilty showed no gender variation nor association with cytomegalovirus (CMV) or EBV infection or lymphoma. A total of 74.04% of adults developed Quilty within the first year posttransplant and 81.48% had multiple Quilty-positive biopsies. One hundred eight of 217 Quilty-positive adults had 456 Quilty-positive endomyocardial biopsies, 82.24% of which were associated with an ISHLT grade of 0 or I, and only 12.28% being associated with a grade III rejection. Histological division into Quilty A and Quilty B did not appear to have clinical significance. Graft vascular disease appears to have decreased significantly more in Quilty-positive patients. Although our findings in children were similar to those in the adults, we were unable to draw definite conclusions, the number of children being too small to permit valid statistical correlations.
Arginine vasotocin activates aggressive calls during paternal care in the Puerto Rican coquí frog, Eleutherodactylus coqui.

The Puerto Rican coqui frog, Eleutherodactylus coqui, is a directly developing frog that exhibits male territoriality and paternal behaviors. Male frogs also produce advertisement and aggressive vocalizations or calls. Territorial males emit advertisement calls to delineate territories and attract mates. Paternal males guard and brood the directly developing embryos during embryogenesis and up to five days after hatching; advertisement calling is normally absent or infrequent during paternal care. Territorial and paternal males commonly produce aggressive calls during agonistic situations. The neuropeptide, arginine vasotocin (AVT), has been shown to promote calling in anurans, including E. coqui. The objective of this study was to determine if exogenous AVT promotes calling and territorial behavior in paternal males and if it promotes males to abandon their offspring. Injections (IP) of AVT were given to paternal males immediately before the scotoperiod. Frogs were monitored for at least four hours after the injection and the following morning for calling activity and abandonment of egg clutches. AVT-injected males showed a dramatic and significant increase in aggressive calls compared to control males (saline injections). Exogenous AVT did induce advertisement calling in some paternal males but did not significantly elevate paternal males to territorial status nor did it significantly induce abandonment of eggs/embryos. In conclusion, the type of vocalization that AVT activates in E. coqui depends upon the reproductive state of the male and the social environment that surrounds the male.
Acquired immunodeficiency syndrome in the elderly.

Recent data from the US show that since 1990 the number of paediatric patients with AIDS is decreasing while the number of patients with AIDS over age 50 years is increasing. To date, little attention has been given to understanding AIDS risk-taking behaviours, clinical presentations, and therapeutic needs of middle-aged and older HIV-infected individuals. Older HIV-infected individuals deteriorate more rapidly than younger patients due to an accelerated loss of CD4+ helper T cells. Despite recognised age-related physiological differences between voung and elderly individuals, scant information about drug optimisation for the treatment of AIDS in older individuals is available. More data need to be collected about this group of AIDS patients, and appropriate treatment strategies designed for their special needs.
Testability guidelines for multichip modules

Abstract Because of the advantages that they offer in clock rates, real-estate savings, power dissipation savings, weight etc., multichip modules are rapidly becoming a reality in commercial electronics. Solutions to the problems of handling and testing module components and to the fabrication of the modules themselves have pretty much been solved. However, before MCMs can become a reality, it will be necessary to solve the problems associated with the testing and repairing of modules. This article suggests a set of design guidelines which will minimize the probability of undetectable defects and maximize the probability of diagnosing detectable defects. The guidelines revolve mainly around the IEEE 1149.1-1990 Test Access Port and Boundary-Scan Architecture standard as adopted by the IEEE.
Enhancement of maze learning in old C57BL/6 mice by dietary lecithin

Abstract Maze learning was studied in young and old C57BL/6 mice. One group of old animals was fed lecithin (supplemented with vitamin E). A second group of old mice and the young mice received standard laboratory mouse chow. The mice were tested on a three-choice-point maze. Young mice learned the maze significantly more easily than either group of old mice. Learning in the lecithin-fed old mice was significantly better than in the control group on a standard diet.
Lorentz violation and synchrotron radiation

We consider the radiation emitted by an ultrarelativistic charged particle moving in a magnetic field, in the presence of an additional Lorentz-violating interaction. In contrast with prior work, we treat a form of Lorentz violation that is represented by a renormalizable operator. Neglecting the radiative reaction force, the particle's trajectory can be determined exactly. The resulting orbit is generally noncircular and does not lie in the plane perpendicular to the magnetic field. We do not consider any Lorentz violation in the electromagnetic sector, so the radiation from the accelerated charge can be determined by standard means, and the radiation spectrum will exhibit a Lorentz-violating directional dependence. Using data on emission from the Crab nebula, we can set a bound on a particular combination of Lorentz-violating coefficients at the $6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}$ level.