cssi/SciSciGPT-SciSciNet huggingface dataset:
Stretched-Exponential Modeling of Anomalous T1ρ and T2 Relaxation in the Intervertebral Disc In Vivo

Purpose: Intervertebral disc degeneration (IVDD), resulting in the depletion of hydrophilic glycosaminoglycans (GAGs) located in the nucleus pulposus (NP), can lead to debilitating neck and back pain. Magnetic Resonance Imaging (MRI) is a promising means of IVD assessment due to the sensitivity of MRI tissue relaxation properties to matrix composition. Furthermore, anomalous (i.e. non-monoexponential) relaxation models have shown higher sensitivity to specific matrix components compared to conventional monoexponential models. Here, we extend the use of the stretched exponential model, an anomalous relaxation model, to IVD relaxometry data. Theory and Methods: T1ρ and T2 relaxation data were measured in the cervical IVDs of healthy volunteers and IVDs adjacent to cervical fusion, and analyzed using both conventional and stretched-exponential (SE) models. Model differences were evaluated via goodness of fit in the healthy data. Normalized histograms of the resultant quantitative MRI (qMRI) maps were described using stable distributions, and data were compared across adjacent disc segments. Results: In the healthy IVDs, we found lower mean squared error in the SE relaxation model fitting behavior compared to monoexponential models, supporting anomalous relaxation behavior in healthy IVDs. SE model parameter αT1ρ increased level-wise in the caudal direction, especially in the nucleus pulposus, while conventional T1ρ and T2 monoexponential measures did not vary. For IVDs adjacent to cervical fusion, SE parameters deviated near the fusion site compared with those in the healthy population. Conclusion: SE modeling of T1ρ relaxation provides greater sensitivity to level-wise variation in IVD matrix properties compared with conventional relaxation modeling, and could provide improved sensitivity to early stages of IVD degeneration. The improved model fit and correlation between the SE αT1ρ parameter with IVD level suggests SE modeling may be a more sensitive method for detection of GAG content variation.
Biomechanical Modeling of Connecting Intermetacarpal K-Wires in the Treatment of Metacarpal Shaft Fractures.

Background Clinical series have been published using the configuration of 2 intercarpal Kirschner wires (K-wires) adjacent to the fracture being connected, but biomechanical analysis is lacking. The objective of this pilot biomechanical study was to model and compare the effects of externally connecting 2 intermetacarpal K-wires for the stabilization of transverse metacarpal shaft fractures. Our research hypothesis was that the connected constructs would be stiffer than the unconnected K-wires. Methods A 3-dimensional computer-based model of small finger transverse metacarpal fracture stabilization was designed with 3 transverse 1.1 mm K-wires being anchored to the adjacent metacarpal. Three arrangements were tested: all 3 K-wires in parallel, the middle K-wire angled toward the proximal wire, and the middle angled K-wire being rigidly fixed to the proximal K-wire. The proximal wire was proximal to the fracture. A finite element analysis was performed by applying a cantilever force of 100 N at the head of the metacarpal. The metacarpal was considered to be uniform in composition with parameters typical for human bone. Kirschner wire parameters for stainless steel were used. Force (N) versus displacement was measured. Results The configuration with the middle angled K-wire being rigidly fixed to the proximal K-wire showed greater stiffness (12 N/mm) than nonattached constructs. The connected construct was 2.3 times more stiff than the unattached parallel construct and 2.5 times more stiff than angling the middle K-wire without attachment. Conclusions In a computer model simulation, our results show that attaching 2 K-wires adjacent to the fracture provides more than twice the stiffness of unconnected K-wires.
The Relationship Between Psychological Processes and Indices of Well-Being Among Adults With Hearing Loss.

Purpose The purpose of this study was to explore the role of psychological processes (i.e., internalized shame, self-efficacy, psychological inflexibility) regarding hearing loss in the well-being ...
Heart surgery and transplantation: innovations impacting on concepts of life and death

The development of heart surgery is briefly reviewed, and the impact it has made on our concepts of life and death are considered. For centuries, death was defined by the cessation of heart beat. In the early days of heart surgery in the 1940s and 1950s, the heart sometimes temporarily stopped beating, but could be resuscitated, and some concluded that the patient had been 'dead' for a period of time. Subsequently, when the patient's brain and other vital organs were protected either by the induction of a state of total body hypothermia or by the support of a heart-lung machine, the heart was purposely stopped from beating for periods of a few minutes to even several hours, but the patient remained alive. When heart transplantation was introduced in 1967, for a period of time the patient not only had no heartbeat, but had no heart, yet was not dead. When total artificial hearts were introduced, the patient permanently had no heart, but remained alive. In the near future, it is likely that the native heart will be permanently replaced by a genetically-engineered pig heart. Organ transplantation, particularly of the heart, contributed further to our changing concepts of life and death. In 1963, surgeons began to remove organs from donors whose brain had been irreversibly damaged, and had been diagnosed as being 'brain-dead', but in whom the heart was still beating. By 1968, the beating heart was routinely removed from brain-dead donors and transplanted into recipients, but this was no longer considered to be illegal as brain death had become the definitive definition of death, not lack of a heart beat or even lack of a heart.
Influence of rye cover cropping on denitrification potential and year-round field N2O emissions

Cover cropping is beneficial for reducing soil erosion and nutrient losses, but there are conflicting reports on how cover cropping affects emissions of nitrous oxide (N2O), a potent greenhouse gas. In this study, we measured N2O fluxes over a full year in Illinois corn plots with and without rye cover crop. We compared these year-round measurements to N2O emissions predicted by the Intergovernmental Panel on Climate Change (IPCC) Tier 1 equation and the Denitrification-Decomposition (DNDC) model. In addition, we measured potential denitrification and N2O production rates. The field measurements showed typical N2O peaks shortly after fertilizer application, as well as a significant late-winter peak. Cover cropping significantly reduced all peak N2O fluxes, with decreases ranging from 39 to 95%. Neither model was able to accurately predict annual N2O fluxes or the decrease in N2O emissions from cover-cropped fields. In contrast to field measurements, lab assays found that cover cropping significantly increased potential denitrification by 90-127% and potential N2O production by 54-106%. The rye cover-cropped plots had lower soil nitrate and higher soil carbon. When limiting nitrate and excess carbon were provided in lab assays, the proportion of N2O resulting from denitrification decreased. These results suggest that the discrepancy between the observed decrease in field N2O emissions and the increase in denitrification potential may be due to the difference in available nutrients between the field and laboratory measurements. Overall, these results suggest the importance of late-winter peaks in N2O emissions and the potential of rye cover cropping to reduce N2O emissions from agricultural fields.
Aerospace materials 2030: challenges and opportunities

Over a hundred years ago, the pioneers of aviation took flight in no small part due to material innovations ranging from novel casting of the aluminum engine block to judicious selection of natural materials. Unquestionably, the future of aerospace will look as different from today as the Wright Flyer and Curtiss June Bug differ from UAVs and F35s. However, the role of materials will remain unchanged; they will be the crucial ingredient that enables these future machines to push the performance envelope and become active partners with the human operator. The presentation will share thoughts on how the materials enterprise could accelerate this future through convergence of innovations in biotechnology, nanotechnology, automation, artificial intelligence, and infomatics.
Multi-Objective Optimization Approach to Pure Strategy Equilibria in Games with Imperfect Information**This work was not supported by any organization

Without the expected utility hypothesis, games with imperfect information can be understood as coupled multi-objective optimizations. Within this framework, equilibria of non-dominated responses are defined and their existence is studied. One class of these equilibria is formulated as Nash equilibria of normal-form games. Another class of these equilibria is formulated with payoff constraints interpreted as robustness of the games. A concrete example is presented and solution methodologies are discussed.
Pharmacological impacts on schizophrenia functional analysis: a postmortem proteome study

Schizophrenia (SCZ) is a severe and debilitating mental illness. Antipsychotic drugs (APDs) are used to treat both positive and negative SCZ symptoms, by influencing the cellular, subcellular-synaptic, and molecular processes. We posit that these effects influence our understanding of SCZ. To address this, we analyzed postmortem dorsolateral prefrontal cortex grey matter samples from control and SCZ subjects (n=10/group) using liquid-chromatography mass-spectrometry-based proteomics. We retrieved SCZ-altered and APD-influenced proteome-sets using linear and mixed linear models, respectively, and validated them experimentally using independent cohorts and insilico using published datasets. Functional analysis of proteome-sets was contrasted at the biological pathway, cell-type, subcellular-synaptic, and drug-target levels. The SCZ-altered proteome was conserved across several studies from DLPFC and other brain areas and was dependent on drug effect. At the pathway level, we observed an aberrant extracellular event and, except for homeostasis, signal-transduction, cytoskeleton, and dendrites associated downregulated changes, the APDs compensated for the majority of the SCZ-altered pathways. At the cell-type level, the up-and down-regulated SCZ-altered events were associated with two different subsets of striatum projecting layer-5 pyramidal-neurons regulating dopaminergic secretion. At the subcellular synaptic level, compensatory pre- and post-synaptic events were observed. At the drug target level, dopaminergic processes influence the SCZ-altered up-regulated proteome, whereas non-dopaminergic and a diverse array of non-neuromodulatory mechanisms influence the SCZ-altered down-regulated proteome. While these findings are dependent on pharmacological effects, they are also consistent with previous SCZ studies, implying the need to re-evaluate previous results. We discuss our findings in the context of cortico-striatal influence in SCZ-pathology.
Digitally Documenting the Transformation of the Eternal City. Cities in Text: Rome

Historical guidebooks and maps of Rome provide both an architectural narrative and a snapshot of the city at distinct historical moments. The Historic Urban Environments Lab at the University of Notre Dame (HUE/ND) combined these resources to create Cities in Text: Rome. This interactive research tool was designed to analyze the complex layers of the Eternal City. It provides access to the digital representation of guidebooks produced in the sixteenth, seventeenth, and eighteenth centuries. These works have been transcribed, translated, and linked with historic and present-day maps, photographs, and drawings presented on a website and mobile application (hue.nd.edu). The project led to several discoveries, including identifying the existing remains of Rome’s medieval residential facade porticoes, which were measured, drawn, and mapped. The work contributes to an understanding of the evolution of Rome’s cityscape, including its medieval fabric wholly ignored in these guides but still visible today.
The Role of Embodiment in Assistive Interactive Robotics for the Elderly

We argue that physically embodied robotics presents a niche of key importance in elder care of the future. We present our work toward assistive interactive robotics that will enable intelligent robots, using little if any physical contact with users, to provide individualized and adaptive monitoring, coaching, training, encouragement, and aid to people with a variety of needs.
Bottle Nomenclature: a Glossary of Landmark Terminology for the Archaeologist

Recognizing the lack of uniformity in the literature with regard to bottle nomenclature, an attempt is made to provide some degree of consistency. The problem does not lie entirely with the terminology currently being used but rather with a lack of a precise definition of that terminology. Although not exhaustive, the glossary should be of assistance to the average archaeologist.
The calcium-sensing receptor: physiology, pathophysiology and CaR-based therapeutics.

The extracellular calcium (Ca2+_o)-sensing receptor (CaR) enables the parathyroid glands and other CaR-expressing cells to sense alterations in the level of Ca2+_o and to respond with changes in function that are directed at normalizing the blood calcium concentration. In addition to the parathyroid gland, the kidney is a key site for Ca2+_o-sensing that enables it to make physiologically relevant alterations in divalent cation and water metabolism. Several disorders of Ca2+_o-sensing arise from inherited or acquired abnormalities that “reset” the serum calcium concentration upward or downward. Inactivating mutations produce a benign form of hypercalcemia when present in the heterozygous state, termed Familial Hypocalciuric Hypercalcemia (FHH), while homozygous mutations produce a much more severe hypercalcemic disorder resulting from marked hyperparathyroidism, called Neonatal Severe Hyperparathyroidism (NSHPT). Activating mutations cause a hypocalcemic syndrome of varying severity, termed autosomal dominant hypocalcemia or hypoparathyroidism. Inactivating or activating antibodies directed at the CaR produce the expected hyper- or hypocalcemic syndromes, respectively. “Calcimimetic” CaR activators and “calcilytic” CaR antagonists have been developed. The calcimimetics are currently in use for controlling severe hyperparathyroidism in patients receiving dialysis treatment for end stage renal disease or with parathyroid cancer. Calcilytics are being evaluated as a means of inducing a “pulse” in the circulating parathyroid hormone (PTH) concentration, which would mimic that resulting from injection of PTH, an established anabolic form of treatment for osteoporosis
2013-11 Ambiguity aversion among student subjects: the role of probability interval and emotional parameters

AbstractIn the literature on decision-making under uncertainty, it has been shown that decision-makers tend to prefer taking gambles with known-risk probabilities (pure risk) over equivalent gambles with ambiguous probabilities. This article contributes to the ongoing discussion in the literature on cognitive and non-cognitive covariates of ambiguity aversion. Through a series of experiments, it finds that subjects are more ambiguity-averse to prospects with wide probability intervals than to an equivalent prospect with narrow intervals, and that subjects’ inherent trust, happiness and level of optimism affect the level of ambiguity aversion.
Empowering patients using cloud based personal health record system

One of the main goals of the electronic health record (EHR) system is to empower patients to access to their own medical decisions. However, medical data is largely coming from clinical institutions so there is no way for them to conttrol or maintain their own medical record. Patients or guardians may need to keep track of their medical data such as observed symptoms or measurements that may not be available in the EHR. Additionally, clinical decision without patient medical history can be error-prone and even be detrimental. Personal medical condition history is considered as the one of the weakest links in the current healthcare systems. For those reasons, it is necessary to have an effective and efficient personal health record system (PHRS) that allows patients or guardians to constantly monitor and control the personal health record. We propose a cloud based personal health record system that allows constant monitoring capability by supporting dynamic creation of clinical document architecture (CDA) document from a mobile device. The generated CDA document may be used to assess current health against major diseases through a clinical decision support system. We provide constant monitoring capability by using easy uploading module and decision support system. Our proposed system uses medical coding standards such as ICD-9-CM, SNOMED CT, etc. to achieve interoperability between different electronic health record systems.
The Costs and Benefits of Disinflation

In the G-7 as in almost all the industrialized countries, inflation is now as low as it was during the golden age of 1960-73 (Table 1)1. Thus for many indus trialized countries, the inflation policy question in 1993 is not whether to disinflate, but rather how and how far to preserve the gains of the disinflation of recent years. Some OECD countries, including Germany, Italy, and Spain, still face the challenge of further disinflation, as do formerly medium inflation countries such as Chile, Israel and Mexico.
ESTIMATING COSTS OF EARTHWORK VIA SIMULATION

In order to establish the unit price estimate for the earthmoving phase of a project, a selection of the equipment fleet and the management policy decisions governing it, must be made. In order to make a rational selection between the available alternatives the productivity consequences associated with each alternative must be known in advance. A method of computer simulation of an earthmoving operation, based on the GPSS language, is presented. An example project is analyzed, to illustrate how an estimator might determine the productivity consequences with a computer simulation. The computer simulation technique is a powerful management tool, which will assume greater significance in the estimating and planning of projects in the future. It is the objective of this paper to create an interst in this topic within the construction industry.
Redox Balance in the Aging Microcirculation: New Friends, New Foes, and New Clinical Directions

Please cite this paper as: Muller-Delp, Gurovich, Christou, and Leeuwenburgh (2012). Redox Balance in the Aging Microcirculation: New Friends, New Foes, and New Clinical Directions. Microcirculation 19(1), 19–28. Abstract Cardiovascular aging is associated with a decline in the function of the vascular endothelium. Considerable evidence indicates that age-induced impairment of endothelium-dependent vasodilation results from a reduction in the availability of nitric oxide (NO•). NO• can be scavenged by reactive oxygen species (ROS), in particular by superoxide radical (O2•−), and age-related increases in ROS have been demonstrated to contribute to reduced endothelium-dependent vasodilation in numerous large artery preparations. In contrast, emerging data suggest that ROS may play a compensatory role in endothelial function of the aging microvasculature. The primary goal of this review is to discuss reports in the literature which indicate that ROS function as important signaling molecules in the aging microvasculature. Emphasis is placed upon discussion of the emerging roles of hydrogen peroxide (H2O2) and peroxynitrite (ONOO•−) in the aging microcirculation. Overall, existing data in animal models suggest that maintenance in the balance of ROS is critical to successful microvascular aging. The limited work that has been performed to investigate the role of ROS in human microvascular aging is also discussed, and the need for future investigations of ROS signaling in older humans is considered.
Loss of the obscurin-RhoGEF downregulates RhoA signaling and increases microtentacle formation and attachment of breast epithelial cells

// Nicole A. Perry 1 , Michele I. Vitolo 2,3 , Stuart S. Martin 2,3 and Aikaterini Kontrogianni-Konstantopoulos 1,3 1 Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 2 Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 3 Marlene and Stewart Greenebaum National Cancer Institute Cancer Center, University of Maryland School of Medicine, Baltimore, MD Correspondence: Aikaterini Kontrogianni-Konstantopoulos , email: // Keywords : Breast cancer, metastasis, obscurin, actomyosin contractility, paclitaxel, circulating tumor cells, microtentacles Received : June 27, 2014 Accepted : August 09, 2014 Published : August 10, 2014 Abstract Obscurins are RhoGEF-containing proteins whose downregulation has been implicated in the development and progression of breast cancer. Herein, we aim to elucidate the mechanism for increased motility of obscurin-deficient cells. We show that shRNA-mediated obscurin downregulation in MCF10A cells leads to >50% reduction in RhoA activity relative to scramble control (shCtrl), as well as decreased phosphorylation of RhoA effectors, including myosin light chain phosphatase, myosin light chain, lim kinase, and cofilin, in both attached and suspended cells. These alterations result in decreased actomyosin contractility, allowing suspended cells to escape detachment-induced apoptosis. Moreover, ~40% of shObsc-expressing cells, but only ~10% of shCtrl-expressing cells, extend microtentacles, tubulin-based projections that mediate the attachment of circulating tumor cells to endothelium. Indeed, we show that MCF10A cells expressing shObsc attach in vitro more readily than shCtrl cells, an advantage that persists following taxane exposure. Overall, our data suggest that loss of obscurins may represent a substantial selective advantage for breast epithelial cells during metastasis, and that treatment with paclitaxel may exacerbate this advantage by preferentially allowing obscurin-deficient, stem-like cells to attach to the endothelium of distant sites, a first step towards colonizing metastatic tumors.
Health behavior, illness behavior, and sick-role behavior. II. Sick-role behavior.

(1966). Health Behavior, Illness Behavior, and Sick-Role Behavior. Archives of Environmental Health: An International Journal: Vol. 12, No. 4, pp. 531-541.
Value of digital fluoroscopy for the diagnosis of Pneumatosis coli

Two cases are presented of benign pneumatosis coli diagnosed on digital fluoroscopic barium enema examinations, in which the gas-filled cysts in the colonic wall were only recognized by postprocessing of the images (i.e. increasing the brightness and contrast settings) at the computer workstation. When digital barium enemas are performed, we therefore recommend image postprocessing to evaluate polypoid lesions in order to differentiate pneumatosis coli from true colonic neoplasms.
Target recognition based on a computational vision model

A simulation of human pattern recognition is outlined which classifies objects based on outputs of a computational vision model, called the Georgia Tech Vision (GTV) model. It is shown that the simulation is able to identify high- level features of military targets, and that identification of high-level features can be used as a tool for recognizing targets. The results suggest that the computational vision model will simplify the task of simulating target recognition by providing a 'front-end' that simulates the basic features that human observes use to recognize targets.
Appearance Potentials and Kinetic Energies of Ions from N2, CO, and NO

A recently developed method has permitted the measurement of excess translational energy of ions formed in a time‐of‐flight mass spectrometer. The method, in conjunction with the RPD technique for determining appearance potentials, has been applied to the electron‐impact study of nitrogen, carbon monoxide, and nitric oxide. A total of 31 different ionization processes have been observed and identified, several of which had not been previously reported in the literature.
Improved stability criterion for linear stochastic systems

The present paper is concerned with the study of Asymptotic Stability With Probability One (ASVVPI) of a class of linear time-varying-constraint stochastic systems by means of the stochastic version of Lyapunov's Second Method. The improved results presented in this paper show that, when the noise affecting the system is linearly related to the state of the system, a frequency-domain in-equality, guaranteeing an asymptotic stability with probability one, exist and has a simple geometric interpretation. The stochastic version of Lyapunov's Second Method, along with a modified Meyer-Kalman-Yakubovich (M.K.Y.) lemma is used in deriving the stability criterion. The relationship of the criterion derived with the stability properties of noise-free systems, the Circle and the Popov Criteria, is discussed.
Disaggregatory action of phosphodiesterase inhibitors.

Summary Papaverine and three hypotensive xanthines were shown to disaggregate platelet clumps in anaesthetized cats. The order of disaggregatory potency was: IMBX > papaverine > > aminophylline ≫ xantinol nicotinate. This effect was not associated with the release of prostacyclin. It is concluded that disaggregatory action of papaverine and xanthines is due to inhibition of phosphodiesterase in platelets.
Electron tunneling study of the superconducting proximity effect in Pb-Cd

Electron tunneling has been used to study the superconducting state in superimposed Pb-Cd thin films in which the Pb thickness varied from 950 to 330 A. The measured transition temperature T/sub c/ varied from 7.22 to 4.86 K in the samples, and the observed energy gaps varied from 1.38 to 0.43 meV. The tunneling density of states as recorded on either side of the sandwich resembles those predicted by the McMillan model, but there are some quantitative differences. The observed phonon structure in the density of states occurs at the same energy as that in bulk Pb, and the magnitude of the structure scales with T/sup 2//sub c/. The shape of the calculated phonon spectral function remains essentially unchanged throughout this series.
Modification of the structure sensitivity of supported Pt catalysts

Abstract A number of probe reactions including hydrogenation, hydrogenolysis, exchange and oxidation have been investigated over two series of Pt/SiO2 and Pt/Al2O3 catalysts. These encompass a wide range of percentage metal exposed, and have been thoroughly characterized by hydrogen chemisorption, reactivity of surface oxygen and x-ray line profile analysis. While the original interest was to examine the relation between metal morphology and catalytic behavior, it turns out that pretreatment conditions are as important, or more so, in the determination of catalytic activity and selectivity.
New and Notable: Uncertainty Quantification

Johnston et al. (1), in this issue of the Biophysical Journal, show us that simple calculations are not so simple when there is uncertainty in the underlying input data. They illustrate this using an on-line CALADIS calculator where the uncertainty in a variable or parameter is represented using a probability density function (pdf). CALADIS calculations are done using Monte Carlo, drawing 20,000 (or other) successive samples from the pdfs for the components of the equations, and using them to add, subtract, multiply, or divide.
Modeling study of mesh conductors and their electroluminescent devices

Numerical models were established to correlate with the experimentally measured properties of mesh conductors previously developed through a combined process of dip coating carbon nanotubes and inkjet printing poly 3,4-ethylenedioxythiophene: poly styrene sulfonate. The electroluminescent (EL) devices assembled with such mesh conductors as front electrodes were modeled by commercially available finite element method software COMSOL Multiphysics. The modeling results are in agreement with those from the experiments and suggest that an optimized fiber arrangement is the key for further improving the performance of EL devices based on mesh conductors.
Scientific Reasoning Abilities of Nonscience Majors in Physics-Based Courses.

We have found that non-STEM (science, technology, engineering, and mathematics) majors taking either a conceptual physics or astronomy course at two regional comprehensive institutions score significantly lower preinstruction on the Lawson’s Classroom Test of Scientific Reasoning (LCTSR) in comparison to national average STEM majors. Based on LCTSR score, the majority of non-STEM students can be classified as either concrete operational or transitional reasoners in Piaget’s theory of cognitive development, whereas in the STEM population formal operational reasoners are far more prevalent. In particular, non-STEM students demonstrate significant difficulty with proportional and hypothetico-deductive reasoning. Prescores on the LCTSR are correlated with normalized learning gains on various concept inventories. The correlation is strongest for content that can be categorized as mostly theoretical, meaning a lack of directly observable exemplars, and weakest for content categorized as mostly descriptive, where directly observable exemplars are abundant. Although the implementation of research-verified, interactive engagement pedagogy can lead to gains in content knowledge, significant gains in theoretical content (such as force and energy) are more difficult with non-STEM students. We also observe no significant gains on the LCTSR without explicit instruction in scientific reasoning patterns. These results further demonstrate that differences in student populations are important when comparing normalized gains on concept inventories, and the achievement of significant gains in scientific reasoning requires a reevaluation of the traditional approach to physics for non-STEM students.
Port-Access coronary artery bypass grafting: technical considerations and results.

Background: This study reviews the results of an initial experience with minimally invasive coronary bypass surgery using the Port-AccessTM approach in terms of early outcome and safety. Methods: Between October 1996 and July 1997 49 Port-AccessTM minimally invasive coronary artery bypass grafting procedures were performed at our institution. The patients' mean age was 59.8 years (range 34 to 82 years). Sixteen patients received single vessel and 37 patients received multivessel bypass grafts. Results: There were no operative deaths and no perioperative myocardial infarctions, neurological deficits, or conversions to sternotomy. Early complications included reoperation due to bleeding in 4 patients, reoperation for a pulmonary embolus in 1 patient, and angioplasty for occlusion of a right coronary artery graft in 2 patients. Postoperative angiograms were obtained in 86% (42/49) of the patients and showed 100% patency for left internal mammary artery to left anterior descending artery grafts and 96% patency for all grafts. Conclusions: These results demonstrate that Port-AccessTM coronary artery bypass grafting using endovascular techniques for cardiopulmonary bypass and cardioplegic arrest can be performed safely with minimal morbidity and mortality. This technique allows multivessel revascularization on a protected, arrested heart with excellent anastornotic precision and reproducible early graft patency. Expanded use of Port-AccessTM techniques is indicated in patients with multivessel coronary artery disease and the technique should be considered for patients with left anterior descending artery restenosis and patients with complex left anterior descending artery lesions where angioplasty results are suboptimal. (J Card Surg 1998;13:28l -285)
A PRELIMINARY QUANTITATIVE ANALYSIS OF PRECIPITATION MECHANISMS

Abstract The two principal physical mechanisms for the formation of precipitation are considered to be the Bergeron-Findeisen ice-crystal process and the collision of particles of unlike size in the gravitational field. Quantitative estimates of the growth of precipitation elements by the two processes are made. It is found that the ice-crystal effect is much more rapid than the collision process in the initial stages of growth. When the particles are of a mass comparable to drizzle drops, the two processes are equally effective; for larger particles the accretion process becomes more rapid than the ice-crystal effect. For typical mid-latitude conditions it is concluded that neither process, acting alone, is capable of producing rain drops of the customarily observed size. It appears that there is required some combination of the two processes such as the clumping of ice crystals to form snow flakes, the growth of ice crystals which melt and then grow by accretion, or the growth of graupel by the simultan...
Alteration in the organ distribution of iron by truncated transferrin: implications for iron chelation therapy

Abstract The ability of the partial molecule of transferrin, truncated transferrin (t-Tf), to act as an excretable biologic iron chelator was examined. We confirmed the observations of Zak and Aisen (Zak O, Aisen P. Biochem Biophys Acta 1985; 1952:24-8) that thermolysin treatment of human transferrin produces half molecules that retain iron-binding capacity. These molecules are poorly recognized by surface receptors on either human or murine cells. Although the plasma half-life of human transferrin in mice is moderately long (40 hours), injection of t-Tf into mice results in its rapid clearance (half-life = 10 minutes). Injection of iron 59-labeled transferrin results in the deposition of iron in the major hematopoetic organs of mice such as the spleen, bone marrow, and liver. Injection of 59Fe-labeled t-Tf results in the quantitative recovery of iron in the kidneys: 59Fe is retained in the kidney for substantial periods of time with little evidence of its excretion into urine. Injection of iodine 125-labeled t-Tf also results in the deposition of radioactivity in the kidneys, but 125I is rapidly excreted into the urine, where it is detected as free iodine. These results indicate that although t-Tf is directed to the kidney and filtered by the glomerulus, the molecule is reabsorbed and degraded, and iron is retained. These results have implications in the design of iron chelators.
Psychotropic medication discussions in older adults' primary care office visits: So much to do, so little time.

Objectives: To examine discussions of psychotropic medications during the older patient's visit to primary care physicians, identify how physician's competing demands influence these discussions, describe different scenarios physicians utilize to address mental health complaints of older adults, and recommend best practices for diagnosing and treating such patients. Method: Convenience sample of 59 videotapes of primary care office visits involving mental health discussions in the United States complemented by patient and physician surveys. Videotaped visits were examined using logistic regression for grouped-level data to explore contributions of physician's competing demands to the likelihood of having psychotropic medication discussions. Tape transcripts were selected to provide examples of prescribing and referral behaviors. Results: One-third of these visits contained no psychotropic medication discussions despite its important role in treating mental illnesses. When prescribing psychotropic medicine...
The Determination of Plasma Corticosterone of Chickens by High Pressure Liquid Chromatography

Abstract A simple method for separating and measuring chicken plasma corticosterone by high pressure liquid chromatography (HPLC) is described. Plasma was extracted twice, first, with isooctane to remove nonpolar steroids and, second, the polar steroids were extracted with dichloromethane. Analytical recovery of added corticosterone was 96.5 ± 1.9% (mean ± SE). Interassay variability was
Reginald Pecock on the Authority of Reason, Scripture and Tradition

Bishop Reginald Pecock ( c . 1390–1461) is remembered for vernacular works formulated to combat Lollardy using reason, not the force of ecclesiastical authority. He argued that Scripture's teachings are true not because they are in Scripture, but because they are evident to unassisted reason. While scholars have explored his arguments in ecclesiastical and historical context, little analysis exists of the scholastic background to Pecock's conception of the relation of reason to faith. This article suggests that Pecock's arguments are grounded in the thought of Aquinas and Scotus, and illustrates how his understanding of reason's capabilities directs his conception of the authority of Scripture and church tradition.
Effect of feeding level and dietary electrolytes on the arginine requirement of rainbow trout (Salmo gairdneri)

Abstract Experiments were conducted to determine the effect of level of feeding (restricted feeding and feeding to satiation) and dietary variations in the balance of monovalent minerals on the arginine requirement of rainbow trout fingerlings. Based on growth and efficiency of feed utilization for growth, the arginine requirement was lower (3.5% of protein) when fish were fed to satiation than when they were fed at a restricted level (4.2% of protein). When calculated on the basis of the amount of arginine consumed per day, however, the requirements were similar for fish subjected to the two methods of feeding. Three balances (acidic, neutral, and alkaline) of sodium, potassium and chloride were used in several experiments. The arginine requirement tended to be higher when fish were fed diets containing the alkaline as compared to the acidic balance of minerals. These studies indicate that the method of feeding has a significant effect on the dietary concentration of arginine needed to maximize growth rate and feed utilization in rainbow trout.
RADIATION AND CONTROL OF SOUND FROM EVOLVING WAVE PACKET ON A CONCAVE-CONVEX SURFACE

Active control of the acoustic pressure in the far field resulting from the growth and decay of a wave packet convecting in a boundary layer over a concave-convex surface is investigated numerically using direct computations of the Navier-Stokes equations. The resulting sound radiation is computed using the linearised Euler equations with the pressure from the Navier-Stokes solution as a time-dependent boundary condition. The acoustic far field exhibits a directivity type of behaviour that points upstream to the flow direction. A fixed control algorithm is used where the attenuation signal is synthesised by a filter that actively adapts itself to the amplitude-time response of the outgoing acoustic wave.
Food restriction alters the age-related decline in cardiac β-adrenergic responsiveness

The responsiveness of the heart to β-adrenergic receptor stimulation declines with age. The aim of this study was to determine whether food restriction (FR), the most effective means of retarding the aging processes, affects the loss of β-adrenergic responsiveness. Male Fisher 344 rats, fed either ad libitum (Group A) or allowed to eat only 60% of what Group A rats consumed (Group B), were sacrificed at 4, 11 or 22–28 months of age. The hearts were isolated and perfused via the Langendorff method. Ventricular pressure-volume curves were constructed to determine the optimal volume for pressure development and concentration-response curves to isoproterenol were obtained at this optimal volume. Interestingly, the ventricular pressure-volume curve for 4 month Group B lay to the left of all the other groups, suggesting that hearts from younger FR rats possessed higher contractility than the other groups. In the unstimulated heart, aging was associated with a slower relaxation phase of contraction and FR further slowed the relaxation. The maximum response of the heart to isoproterenol declined with age and the decline was unaffected by FR. The concentration-response curves of hearts from older rats were generally shifted to the right of the younger animals, while FR shifted the curves to the left toward greater sensitivity to β-adrenergic stimulation. The EC50s for isoproterenol increased with age, indicating a decrease in the responsiveness of the heart to β-adrenergic receptor stimulation. In contrast, FR decreased the isoproterenol EC50, suggesting an enhanced responsiveness. These results demonstrate that FR can retard some aging changes (loss in β-adrenergic responsiveness), while it enhances others (increase in relaxation times).
Simulation output analysis using integrated paths II: Low bias estimators

This article is a sequel to a previous article that introduced a class of variance estimators for steady-state simulation output analysis. The estimators were constructed by applying a quadratic function to a vector obtained from iterated integrations of the simulation output. The previous article concentrated on deriving the limiting distributions of the estimators and on their computational efficiency for a particular choice of quadratic function. The present article considers estimators constructed from different quadratic functions, chosen mainly to reduce bias compared to the estimators of the previous article. Overlapping and nonoverlapping batch means versions of the estimators are discussed.
Valence-band plasmon effects on line shifts and widths in positron planar-channeling radiation

A dynamical description of spectral shifts and widths of positron planar-channeled radiation is presented. The presence of well-defined valence electron collective oscillations or plasmons as documented in electron-loss spectroscopy is proposed as one mechanism for experimentally observed negative shifts. Qualitative comparison with the experimental data at 55 MeV for diamond, silicon, and LiF is indicated.
Implementation of an adaptive Shack-Hartmann sensor using a phase-modulated liquid crystal spatial light modulator

In this paper we demonstrate a closed-loop adaptive-optics system that uses a twisted nematic liquid-crystal television (LCTV) as an adaptive Shack-Hartmann wave front sensor (SHWS). This system writes a dynamic lenslet array onto the LCTV so that each subaperture generates a focal spot at the focal length of the lenslet array. The focal spots of the lenslet array are detected by a video CCD camera. The focal spots move around if turbulence exists in the system, therefore the locations of the distorted focal spots are computed using a centroid algorithm and used to correct the local tilted wave fronts. Using the centroid shift data from all of the subapertures of the lenslet array, the incident wave front can be calculated and the phase can be reconstructed. In this experiment we assume that the slope of the disturbed wave front in a subaperture is the spatially averaged wave front tilt, and a correcting LCTV uses a simplifying linear approximation to generate a compensating tilt at each subaperture.
Biogeography of the octocorallian coelenterate fauna of southern Africa

The geographical and bathymetric distribution of southern African octocorals is analysed. Of the over 200 estimated species of regional octocorals, 81 confirmed and adequately described species are studied using a radial sector method. Two primary faunal components are recognized–endemic (53.3% of the fauna by numbers of species) and Indo-Pacific (39.4%). An Atlantic component contributes only minimally (about 1.7%), while the remaining fauna is made up of cosmopolites (2.8%) and scattered species (2.8%). A subantarctic component is not evident for the present-day, although evidence for previous contact is presented. A sister-group analysis using genera as a guide to sister species, shows the biogeographic affinities for the present-day fauna as a whole to be 45% Indo-Pacific, 31% cosmopolitan, 10% endemic, 10% Atlantic and 4% southern oceans (subantarctic). Applying the same method to only those genera with endemic species shows the affinities of the present-day endemic fauna to be 27.5% Indo-Pacific, 27.5% endemic, 24% cosmopolitan, 14% Atlantic and 7% subantarctic. Clearly defined boundaries for west, south, and east coast faunas (as recognized by previous authors in describing various intertidal faunas) are found not be present with regard to the octocoral fauna (largely due to its overwhelmingly subtidal nature). Instead two primary zoogeographic provinces are recognized–the Cape Endemic Province (extending from Liideritz to Inhaca Island) and the south-western fringe of the Indo-Pacific Province from East London north-eastwards. An overlap zone between these two is recognized between East London and Inhaca Island, with the region in the vicinity of Richards Bay having an essentially evenly mixed fauna (roughly 50% Cape Endemic Province and 50% Indo-Pacific). Of the 84 octocoral genera recorded for the region, seven (or 8.3%) are endemic, and of these, five are monotypic while two are ditypic. The fauna is shown to be predominantly sublittoral (about 95% by numbers of species), the shallow sublittoral (< 100 m in depth) being the region with highest species richness. Pennatulaceans are eurybathic (intertidal to 4756 m) and clearly show a high proportion of cosmopolites (20% of presently identified species). Soft corals are stenobathic and restricted to the intertidal, continental shelf and uppermost portion of the continental slope (<500m), while gorgonians are intermediate in depth distributon (intertidal to 1200 m). No cosmopolitan alcyonaceans are presently recorded. The centre of the Cape Endemic Province is the Agulhas Bank–an extensive region of shallow continential shelf (< 200 m in depth) between Cape Town and East London. Two regions of octocoral radiation for southern Africa are postulated–the Agulhas Bank and the western Indian Ocean.
Plant Species Composition and Productivity following Permafrost Thaw and Thermokarst in Alaskan Tundra

Climate warming is expected to have a large impact on plant species composition and productivity in northern latitude ecosystems. Warming can affect vegetation communities directly through temperature effects on plant growth and indirectly through alteration of soil nutrient availability. In addition, warming can cause permafrost to thaw and thermokarst (ground subsidence) to develop, which can alter the structure of the ecosystem by altering hydrological patterns within a site. These multiple direct and indirect effects of permafrost thawing are difficult to simulate in experimental approaches that often manipulate only one or two factors. Here, we used a natural gradient approach with three sites to represent stages in the process of permafrost thawing and thermokarst. We found that vascular plant biomass shifted from graminoid-dominated tundra in the least disturbed site to shrub-dominated tundra at the oldest, most subsided site, whereas the intermediate site was co-dominated by both plant functional groups. Vascular plant productivity patterns followed the changes in biomass, whereas nonvascular moss productivity was especially important in the oldest, most subsided site. The coefficient of variation for soil moisture was higher in the oldest, most subsided site suggesting that in addition to more wet microsites, there were other microsites that were drier. Across all sites, graminoids preferred the cold, dry microsites whereas the moss and shrubs were associated with the warm, moist microsites. Total nitrogen contained in green plant biomass differed across sites, suggesting that there were increases in soil nitrogen availability where permafrost had thawed.