cssi/SciSciGPT-SciSciNet huggingface dataset:
SU‐E‐T‐233: Commissioning of An Implantable Dosimeter for External Beam Radiation Therapy

Purpose: To commission a Dose Verification System (DVS) with permanently implanted in vivo dosimeters. To acquire and evaluate sufficient data for establishing standard of quality in a clinical setting.Methods: DVS is permanent implantable wireless radiation sensor based on MOSFET for absolute dosemeasurements. To evaluate characteristics of dosimeter, following tests were performed: temperature dependence, reproducibility, field size dependence, post‐irradiation signal drift, dependence on average dose‐rate, linearity test, angular dependence, dose‐rate dependence, irradiation depth dependence and a multiple reading effect. Dosimeter is not currently calibrated for use in kV range. Nonetheless, effects of conebeam CT(CBCT) imaging to dosimeter were investigated. Phantom studies were performed in both air and water using an Elekta Synergy‐S Beam‐Modulator linear accelerator. Results: DVS dosimeters have been calibrated to be used at 37C. Reproducibility tests were performed at room temperature. Readings were −3.2% low (SD=2.5%, or 5.06cGy for 200cGy delivered). Same tests in water at human body temperature showed 1.5% absolute difference, with a similar deviation (SD=2.85%). It was observed that measurement signal decayed significantly with time post‐irradiation, from +3% after 0.5min to −3.5% after 10min. Dose linearity was within 2% for absorbed total dose of 75Gy. Signal rapidly decayed after total dose of 82Gy. Angular dependence was −0.3% (SD=2.31%). Readings decreased with increase in depth, about 0.3%/cm. No filed size and dose‐rate difference were observed. Average dose reading due to CBCTimaging using the pelvis protocol was 7.89cGy (SD=1.46cGy) Conclusions: Extensive acceptance and commissioning measurements have shown considerable post‐radiation signal drift, temperature dependence, reproducibility variation, and rotational isotropy. This process confirmed manufacturer's stated performance and provided baseline QA necessary to implement DVS clinically. System is currently implemented with ±7% tolerance. Dosimeter can be used to quantify dose at depth, as well as to evaluate adherence between dose from treatment plan and daily delivery.
Electrostatic investigation into the bonding of poly(phenylene) thiols to gold

The advancement of nanotechnology relies on the understanding of electrical connection to individual molecules. Electrostatic surface potential measurements of self-assembled monolayers can provide insight into the structural and electronic properties of molecules attached to surfaces. In this paper we report on the electrostatic potential of poly(phenylene) thiol molecules bound to gold surfaces. Kelvin force microscopy is used to probe self-assembled monolayers of a series of phenyl, biphenyl, and triphenyl thiol molecules. The dipole moments of the isolated molecules have been determined and show similar electronic trends. A difference in polarity between the isolated molecules and the electrostatic surface potential of a monolayer attached to gold reflects the electron transfer on to the bound molecule.
Populism and rent‐seeking in post‐apartheid South Africa

Abstract The Freedom Charter and the ANC's constitutional guidelines reveals that they rely upon a model of “populist democracy” which also justifies the status and policies of the National Party. Although ends differ, means for legitimising power are the same. A critique of “populist democracy”, based upon public choice theory, reveals procedural flaws and implementation failures of populist democracy. Having identified these problems, an alternative model is prescribed to serve as a constitutional framework. It is suggested that a set of rules be prescribed to constrain actions of the state rather than to seek “innovations” which prompt an enlarged political intrusion into the lives and livelihoods of citizens.
HIV drug resistance prediction using multiple regression

Drug resistance is commonly encountered during treatment for HIV/AIDS, and decreases the efficacy of the antiviral drugs. Genotyping the infecting virus gives sequence data for computational prediction of resistance, which is more efficient than performing experimental assays for resistance. Current predictions rely on simple rules with modest accuracy; therefore, a prediction method with high accuracy is needed to improve drug selection for therapy. Here, we apply a hybrid sequence/structure protein representation in conjunction with multiple regression for predicting resistance to drugs. The algorithm was tested on genotype-phenotype data for HIV-1 protease (PR) and HIV-1 reverse transcriptase (RT). The overall cross-validated regression R2-values were 0.51-0.72 for predicting resistance to four PR inhibitors; and 0.76-0.91 for three RT inhibitors demonstrating successful predictions.
Thermal Noise from a Passive Linear Multiport

The thermal noise from passive multiports is discussed from fundamentals so that it can be understood, measured, or calculated by a microwave engineer. The multiports are assumed to have a uniform temperature, but with no restriction on reciprocity or mismatch. The noise temperature, T/sub N/, contributed by such a multiport is T/sub N/=A T where T is its physical temperature and A is its absorption coefficient. An approximate method of measuring A, and a method of measuring an A as small as 0.008 within 5 percent, are pointed out. Also, exact and approximate expressions for A in terms of scattering matrix elements and termination reflection coefficients are derived. Finally, the crosscorrelation of the noise from different ports is briefly considered.
Expression of the catalytic activity of plasminogen activator under physiologic conditions.

Abstract We have investigated the factors governing the plasminogen-dependent fibrinolysis catalyzed by the serine proteinase, plasminogen activator (EC 3.4.21.-), under physiologic conditions. We found that live rabbit fibroblasts digested much less fibrin than predicted by cell-free assay of the secreted plasminogen activator. The reduced catalytic activity of plasminogen activator expressed by cells growing on fibrin was regulated by the salt concentration of culture medium. The plasminogen activators of cells from several mammalian species were inhibited by physiologic salt concentrations (0.15 M NaCl) in cell-free assays. CaCl2 and KCl, but not D -glucose, were also effective inhibitors. The catalytic activity of purified human urokinase and of plasmin was unaffected by increased ionic strength. Plasminogen activators secreted both spontaneously and in response to stimulation by the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate, were inhibited by 0.15 M NaCl. Physiologic salt concentration appeared to function by interacting with plasminogen activator, or plasminogen, and a third component, possibly a reversible inhibitor. One consequence of this regulation of plasminogen activator under physiologic conditions is the limitation of plasminogen-dependent fibrin degradation by living cels.
The Transfusion Audit as an Educational Tool

Audits of transfusion used as educational tools can improve transfusion practices. Effective audits must first identify problem(s) in transfusion practice and must then include as educational target, the attending physician. Educational methods that have been shown to the effective include: (1) meeting briefly one-on-one with physicians, (2) teaching at scheduled conferences, (3) making daily clinical rounds on patients who receive transfusion, (4) concurrent review of orders for transfusion prior to issue of the blood product and (5) installing algorithms and guidelines in the operating room. Transfusion practices improved with these educational audit methods.
Task analysis, systems analysis and design: symbiosis or synthesis?

Abstract The relationship between methods for systems development that have originated from work in human-computer interaction (HCI) and in software engineering are examined using a classificatory framework of the system life cycle and the development issues are addressed. Software engineering methods tackle few HCI issues and would benefit from the addition of HCI principles and techniques. It is contended that two groups of HCI methods can be identified, task/organisation and cognitive task analysis; both of which should be integrated with structured system development methods to improve system usability. To encourage their practice, HCI methods need to be integrated with software engineering and to offer more prescriptive design advice.
Characterization of granulosa cell subpopulations from avian preovulatory follicles by multiparameter flow cytometry.

The objective of the present study was to characterize the granulosa cell populations from individual hen (Gallus domesticus) preovulatory follicles at defined stages of follicular maturation using multiparameter flow cytometry. Granulosa cells were fixed and stained with three fluorochromes that selectively bind to DNA (Hoechst 33342, blue), RNA (pyronin Y, red), or protein (fluorescein isothiocyanate, green). A flow cytometer equipped with a three-laser excitation system was used to analyze three colors of fluorescence from stained cells. Forward angle light scatter and axial light loss measurements were made on each cell to determine relative cell size. In addition, the ratios of RNA to protein and DNA to protein were measured. The major findings obtained from correlated measurements of cell cycle (DNA), protein, RNA, cell size, and ratios were: 1) the percentage of proliferating cells decreased while cell size increased during follicular maturation; 2) two subpopulations of granulosa cells were identi...
Incomplete Fibers Affect Disc Biomechanics Higher Than the Fibers With Laxity: A Finite Element Model Analysis

Disc morphological disruptions — incomplete length and laxity in annular fibers — affect the behavior of the disc tissues in different ways. These changes in fibers alter the main function of the disc — inter-segmental load transfer along the spine — by affecting the surrounding extracellular disc tissue matrix. Tissues surrounding the altered fibers experience variations in stress distributions and the biomechanical reasoning behind variations in stress patterns may be multifactorial. While incomplete fibers are found in both healthy and aged discs with higher occurrences in the later ones [1], laxity in fibers is a progressive degenerative property [2]. How much the fiber incompleteness relative to the laxity in fibers contributes to the disc biomechanics remains to be clearly quantified?Copyright © 2011 by ASME
The C.C.A. syndrome (congenital contractural arachnodactyly): a new differential syndrome for Marfan's syndrome and homocystinuria.

Abstract The first case in the dental literature of congenital contractural arachnodactyly (C.C.A. syndrome) is presented. This newly delineated syndrome is an autosomal dominant heritable disorder of connective tissue. Its similarities to Marfan's syndrome and homocystinuria, as well as other syndromes, are discussed. The lack of cardiovascular disease, specific ocular anomalies, and mental retardation are presented in the differential diagnosis of the C.C.A. syndrome with Marfan's syndrome and homocystinuria.
Modeling and simulation of the effect of proton pump inhibitors on magnesium homeostasis. 1. Oral absorption of magnesium.

Prolonged use of proton pump inhibitors has reportedly caused rare clinically symptomatic hypomagnesemia. A review of the literature suggests PPI drugs may impair intestinal magnesium absorption. With the goal of preventing PPI-induced hypomagnesemia, an oral absorption-centric model was developed by referencing literature data. Our modeling with human data reveals that magnesium absorption is substantial in the distal intestine. We then perform simulations by referring to the reported reduction in mid to distal intestinal pH caused by one week of oral esomeprazole, and to reported reduction of the divalent cation-sensitive current when the carboxyl side chains of glutamic and aspartic residues in the binding channels of TRPM6/TRPM7 were neutralized. Our simulations reveal that short-term PPI therapy may cause a very small reduction (5%) in the serum magnesium level, which is qualitatively consistent with the reported 1% reduction in magnesium absorption following 1 week of omeprazole in humans. Simulatio...
Bone metastases from breast cancer at the time of radical mastectomy as detected by bone scan. Eight‐year follow‐up

Sixty-four women with Stage II breast cancer who had Sr85 bone scans at the time of radical mastectomy were followed for 8 years in a prospective study. Those women with positive scans had a slight, but statistically significant, increased incidence of metastic disease, particularly for metastases to bone.However, 40% of those women with positive bone scans and negative roentgenograms survived 8 years without evidence of any metastatic disease. Therefore, it has not been shown at this time that bone scans should be obtained in order to exclude bone metastasis before regional therapy for breast cancer is instituted. Also, a significant percentage of women with negative bone scans developed both bone and soft tissue metastases. As many as 30% of asymptomatic women with a history of breast cancer and positive bone scans and negative bone roentgenograms may still harbor disease in bone after 8 years.
Budgetary support for police services in U.S. municipalities: Comparing political culture, socioeconomic characteristics and incrementalism as rival explanations for budget share allocation to police

Abstract Only limited research was available on the important question of the likely determinants of changes in budgetary allocations to municipal police agencies over time. Within that rather limited set of studies, three distinct perspectives on hypothesized key determinants of funding levels for police could be identified—namely, the local political culture, the nature of socioeconomic conditions, and the prevalence of incremental budget decision-making processes. This study employed a longitudinal data set derived from municipal clerk surveys administered in four waves to the same cross-section of U.S. cities in 1993, 1996, 2000, and 2003. The authors examined the relative utility of these three hypothesized determinants through the use of a two-way random-effects panel model. The findings for 188 U.S. municipal governments suggested that the incremental budgeting aspect of annual budgeting in municipal governments largely explained the variation in share of allocation to police agencies in these cities, with political culture and socioeconomic conditions demonstrating only weak effects at best.
Actin-related protein 2/3 complex is required for actin ring formation.

Actin rings are vital for osteoclastic bone resorption, and actin-related protein 2/3 complex is a pivotal regulator of actin polymerization. Actin-related protein 2/3 complex was found in the podosomes of actin rings. A short interfering RNA knocked down expression of actin-related protein 2 in osteoclasts and disrupted actin rings, suggesting that the complex is crucial to actin ring formation. Introduction: To resorb bone, osteoclasts form an extracellular acidic compartment segregated by a sealing zone. This is dependent on an actin ring that is composed of filamentous actin organized into dynamic structures called podosomes. The actin-related protein 2/3 (Arp2/3) complex is a vital regulator of actin polymerization. We tested whether the Arp2/3 complex is a component of actin rings and is important for actin ring formation. Materials and Methods: Western blot analysis was used to determine levels of Arp2 and Arp3, two components of the Arp2/3 complex in osteoclast-like cells. Confocal microscopy studies using antibodies for immunocytochemistry demonstrated localization of Arp2/3 complex in osteoclasts. Short interfering RNA oligonucleotides (siRNAs) were made against Arp2 and used to knock down its expression. Results: A 3-fold increase in Arp2 and Arp3 was detected during RANKL-induced differentiation of RAW 264.7 cells into osteoclast-like cells. Arp2/3 complex was concentrated in actin rings and enriched near the sealing zone. Arp2/3 complex co-localized with cortactin, a component of podosomes, but not vinculin, which surrounds podosomes. siRNA against Arp2, transfected into RAW 264.7 cells 5 days after stimulation with RANKL, reduced Arp2 protein levels 70% compared with cells transfected with ineffective siRNAs. Cytochemical characterization of RAW 264.7 osteoclast-like cells and marrow osteoclasts in which Arp2 was knocked down revealed fewer podosomes and no actin rings, although many cells remained well spread. Conclusions: These data show that Arp2/3 complex is a component of actin rings and that the presence of Arp2/3 complex is vital to the formation of actin rings. In addition, the results show the use of siRNAs for the study of RAW 264.7 osteoclast-like cells.
Nutritional evaluation of fatty acids for the open thelycum shrimp, Litopenaeus vannamei: II. Effect of dietary n-3 and n-6 polyunsaturated and highly unsaturated fatty acids on juvenile shrimp growth, survival, and fatty acid composition

This study evaluated the nutritional value of dietary n-3 and n-6 polyunsaturated fatty acids (PUFA) such as linoleic (LOA) and linolenic (LNA) acids, and highly unsaturated fatty acids (HUFA) such as arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids for juvenile Litopenaeus vannamei, based on their effects on growth, survival, and fatty acid composition of hepatopancreas and muscle tissue. Diets contained 5% total lipid. A basal diet contained palmitic and stearic acids each at 2.5% of diet. Five diets contained 0.5% dry weight of LOA, LNA, AA, EPA, or DHA. An additional diet evaluated HUFA in combination by supplementing at 0.5% of diet, a mixture of n-3 HUFA. All HUFA showed higher nutritional value than PUFA for shrimp and produced significantly (P < 0.05) higher final weight, weight gain, and total lipid in shrimp muscle. Fatty acid profiles of shrimp tissues reflected the composition of the dietary lipids. In general, saturated fatty acids were more abundant in the neutral factions, while PUFA and HUFA were more abundant in the polar fractions of tissues. Under these experimental conditions, HUFA had much greater nutritional value than PUFA for juvenile L. vannamei; moreover, dietary requirements for PUFA were not demonstrated.
Continuous abdominal raster scanning a technique for increasing anatomic informaiton and reducing scan time

Continuous raster scanning can improve avdominal ′B scan image resolution and decrease the time required for scanning. Rapid, serial, single-sweep scans are performed at 3 to 8 mm intervals during suspended respiration. This technique markedly reduces organ distortion by respiratory and vascular motion. It is best performed with a contact scanner operating in video mode that utilizes a high resolution storage oscilloscope.
Separation of Proteins via pH Parametric Pumping

Abstract An equilibrium theory is used to study pH parametric pumps. Simple graphical procedures for predicting the separation are presented. It is shown that a parapump with a series of columns packed alternately with cation and anion exchangers is capable of yielding very high separation factors. Experimental results are in qualitative agreement with theory.
Are Smart Cards the Smart Way to Go?: Examining Their Adoption by U.S. Transit Agencies

Smart card technologies offer public transit agencies unprecedented opportunity to price services flexibly by time, distance, and mode and in conjunction with neighboring transit operators. They also can simplify boarding, streamline accounting, and provide better passenger data. Some transit systems have moved quickly to adopt smart card fare media, others are moving more cautiously, and still others eschew smart cards—at least for now. Why such differences? U.S. transit agencies were surveyed to gauge current levels of interest in smart card technologies as next-generation fare media; examine knowledge and perceptions of costs, benefits, and risks of smart card adoption; and determine the status of system implementation, the degree of planning toward implementation, and the levels of participation in interagency collaboration to realize interoperability. Factors common to agencies that have and have not adopted smart card technology also were examined. Results indicate that the consideration and adoptio...
TCRγδ cells and viruses

T-cell receptor gammadelta cells (TCRgammadelta) are often found in increased numbers during the course of several viral infections in humans. Although these findings suggest an important role for this unique subset, their precise function has not been ascertained. Recent studies in murine models of both RNA and DNA virus infections have begun to shed new light on the potential function for TCRgammadelta cells in antiviral immunity. It is clear that TCRgammadelta cells participate in the immune response to human immunodeficiency virus (HIV), influenza, Sendai, coxsackie, vaccinia, vesicular stomatitis virus (VSV), and herpes simplex virus-1 (HSV-1) viral infections since they become activated and home to the sites of viral replication. In this review we will summarize current efforts to dissect the role of TCRgammadelta cells in these disease settings, emphasizing the effector functions utilized, the TCR repertoire, and the antigens recognized. Particular focus will be placed on HSV-1 infections where we have begun to address these issues and have shown that TCRgammadelta cells are sufficient for protection from lethal infection and are able to recognize the herpes virus antigen glycoprotein I.
DEXAMETHASONE INHIBITS INSULIN BINDING TO INSULIN-DEGRADING ENZYME AND CYTOSOLIC INSULIN-BINDING PROTEIN P82

We recently demonstrated that insulin specifically binds to several cytosolic insulin-binding proteins (CIBPs) including insulin-degrading enzyme (IDE) and CIBP p82 in cytosol isolated from H35 rat hepatoma cells. Insulin binding to these CIBPs was regulated by culture conditions, such as serum or insulin. In the present study, we examined the effect of dexamethasone on insulin binding to CIBPs in H35 cells. When the cells were treated with 100 nM dexamethasone for 24 hrs, insulin binding to IDE and CIBP p82 was decreased by about 50% without decreasing the expression level of IDE. Insulin added with the dexamethasone prevented the steroid's effect. Furthermore, dexamethasone directly blocked insulin binding to CIBPs in isolated cytosol. These results suggest that dexamethasone, directly or as a complex with other proteins, binds to IDE and CIBP p82 and changes their ability to bind insulin, possibly by inducing a conformational change or by blocking insulin binding sites. IDE was recently identified as a receptor accessory factor for androgen and glucocorticoid receptors and plays an important role in the regulation of gene transcriptional responses. Combined with previous reports, our findings suggest IDE and other CIBPs such as CIBP p82 may play a role in the cross-talk between insulin and the signal transduction pathways of steroid hormones.
An AM1 semiempirical study of longitudinal twisting in PAH and CPAH

Abstract The twisting along the major axis of a series of linear polycyclic aromatic hydrocarbons has been studied by using AM1 semiempirical calculations. Polycyclic aromatic hydrocarbons (PAH) containing only six-membered rings are shown to be easier to twist along their long axis compared with similar PAH containing embedded cyclopentene rings (CPAH). The difference in the energies is evident even at very low twist angles and becomes more pronounced as the twist angle approaches 90°. The calculations were done by defining sets of parallel dihedrals along the long axis of the PAH and CPAH and driving the dihedrals symmetrically while allowing for a full geometry optimization of the rest of the molecule.
Wavefront control for a segmented deployable space telescope

By segmenting and folding the primary mirror, quite large telescopes can be packed into the nose cone of a rocket. Deployed after launch, initial optical performance can be quite poor, due to deployment errors, thermal deformation, fabrication errors and other causes. We describe an automatic control system for capturing, aligning, phasing, and deforming the optics of such a telescope, going from initial cm-level wavefront errors to diffraction-limited observatory operations. This system was developed for the Next Generation Space Telescope and is being tested on the NGST Wavefront Control Testbed.
Studies on olfactory discrimination in dogs: (3) ability to detect human odour trace

Abstract Dogs failed to find human odour trace on glass slides weathered outdoors for three weeks, and were beginning to make some unreliable responses with 1 and 2 week old samples. Similar slide material kept indoors for the same length of time was readily and significantly detected. In fact, high performance scores were recorded up to 6 weeks. There was little correlation between records kept on temperature and climatic changes and the actual work performance scores.
Environment-induced superselection rules

We show how the correlations of a quantum system with other quantum systems may cause one of its observables to behave in a classical manner. In particular, "reduction of the wave packet," postulated by von Neumann to explain definiteness of an outcome of an individual observation, can be explained when a realistic model of an apparatus is adopted. Instead of an isolated quantum apparatus with a number of states equal to the number of possible distinct outcomes of the measurement, discussed by von Neumann, we consider an apparatus interacting with other physical systems, described here summarily as "environment." The interaction of the quantum apparatus with the environment results in correlations. Correlations impose effective superselection rules which prevent apparatus from appearing in a superposition of states corresponding to different eigenvalues of the privileged pointer observable. It is the propagation of the correlations with the pointer basis states which is ultimately responsible for the choice of the pointer observable. It can be thought of as a process of amplification in which the state of many distinct physical systems becomes correlated with the pointer basis state. Whether these environment systems are regarded as a part of the apparatus setup, or as a part of its environment is irrelevant. What is crucial is the redundancy of the record concerning the pointer observable which is imprinted into the correlations. Eigenspaces of the pointer observable provide a natural basis for the pointer of the quantum apparatus and determine the to-be-measured observable of the quantum system. Decay of those elements of the apparatus-system density matrix, which are off-diagonal in the pointer observable, is caused by the natural evolution of the combined system-apparatus-environment object. For a hypothetical finite environment with $N$ distinct eigenvalues of the apparatus-environment interaction Hamiltonian, off-diagonal terms will decay to become of the order of ${N}^{\ensuremath{-}\frac{1}{2}}$, and will recur only on a Poincar\'e time scale. No recurrences will be observed in realistic circumstances. As the correlations spread through the environment on a time scale typically much shorter than the recurrence time scale calculated for the environment already correlated with the pointer observable, the measurement becomes effectively irreversible. Relevance of this model of the measurement process for the understanding of the second law of thermodynamics and its relation to Bohr's "irreversible act of amplification" is briefly discussed. The emergence of the pointer observable can be interpreted as a clue about the resolution of the measurement problem in case of no environment. It points towards the possibility that properties of quantum systems have no absolute meaning. Rather, they must be always characterized with respect to other physical systems.
Knudsen-transitional flow and gas pressurization in leaves of nelumbo.

Pressures in gas spaces of leaves of the lotus Nelumbo are higher than ambient pressure. The pressurization capacity of leaves was studied as a function of leaf temperature, and the composition of air entering evacuated leaves was used to calibrate the pore sizes which determine flow in these leaves. The adaxial side of the leaf of Nelumbo has two distinct regions in terms of gas exchange characteristics. There is a region of relatively high mean pore diameter in the center of the leaf opposite the point of petiole insertion. Gas exchange between the remainder of the leaf (>99% by area) and the atmosphere is restricted by “pores” with an effective mean diameter less than 0.03 micrometer. As a result, a flowthrough ventilation operates within each leaf. Air enters the leaf across the expanse of the lamina, and escapes back to the atmosphere through the highly porous region at the center of the lamina.
Gendered Perspectives in Psychology: Immigrant Origin Youth

In this article, we contend that the field of psychology has largely failed to foreground the role of gender in its study of immigration. Here, we review studies that address gender and migration focusing on the experience of children and adolescents. We provide developmental perspectives on family relations, well-being, identity formation, and educational outcomes, paying particular attention to the role of gender in these domains. We conclude with recommendations for future research, which include the need to consider whether, and if so, how, when, and why it makes a difference to be an immigrant, to be from a particular country, or to be female rather than male. We argue that it is important to consider socioeconomic characteristics; to consider resilience as well as pathology; and to work in interdisciplinary ways to deepen our understanding of the gendered migratory experience of immigrant origin youth.
Cough Cardiopulmonary Resuscitation Revisited

Testing implantable cardioverter-defibrillators requires induction of ventricular fibrillation (VF) to assess detection and termination of the arrhythmia. A 64-year-old man had spontaneous coughing on induction of VF on 3 occasions but did not cough after more sedation. The ECG and femoral artery pressure recording during these episodes are shown in the Figure. Automatic defibrillation occurred after 7 to 10 seconds. Rapid, regular coughing produced arterial blood pressure as high as 176/51 mm Hg …
The Interaction of Na+ and K+ in Voltage-gated Potassium Channels : Evidence for Cation Binding Sites of Different Affinity

Voltage-gated potassium (K+) channels are multi-ion pores. Recent studies suggest that, similar to calcium channels, competition between ionic species for intrapore binding sites may contribute to ionic selectivity in at least some K+ channels. Molecular studies suggest that a putative constricted region of the pore, which is presumably the site of selectivity, may be as short as one ionic diameter in length. Taken together, these results suggest that selectivity may occur at just a single binding site in the pore. We are studying a chimeric K+ channel that is highly selective for K+ over Na+ in physiological solutions, but conducts Na+ in the absence of K+. Na+ and K+ currents both display slow (C-type) inactivation, but had markedly different inactivation and deactivation kinetics; Na+ currents inactivated more rapidly and deactivated more slowly than K+ currents. Currents carried by 160 mM Na+ were inhibited by external K+ with an apparent IC50 <30 microM. K+ also altered both inactivation and deactivation kinetics of Na+ currents at these low concentrations. In the complementary experiment, currents carried by 3 mM K+ were inhibited by external Na+, with an apparent IC50 of approximately 100 mM. In contrast to the effects of low [K+] on Na+ current kinetics, Na+ did not affect K+ current kinetics, even at concentrations that inhibited K+ currents by 40-50%. These data suggest that Na+ block of K+ currents did not involve displacement of K+ from the high affinity site involved in gating kinetics. We present a model that describes the permeation pathway as a single high affinity, cation-selective binding site, flanked by low affinity, nonselective sites. This model quantitatively predicts the anomalous mole fraction behavior observed in two different K+ channels, differential K+ and Na+ conductance, and the concentration dependence of K+ block of Na+ currents and Na+ block of K+ currents. Based on our results, we hypothesize that the permeation pathway contains a single high affinity binding site, where selectivity and ionic modulation of gating occur.
Distribution of Health Care Expenditures for HIV-Infected Patients

Background. Health care expenditures for persons infected with human immunodeficiency virus (HIV) in the United State determined on the basis of actual health care use have not been reported in the era of highly active antiretroviral therapy. Methods. Patients receiving primary care at the University of Alabama at Birmingham HIV clinic were included in the study. All encounters (except emergency room visits) that occurred within the University of Alabama at Birmingham Hospital System from 1 March 2000 to 1 March 2001 were analyzed. Medication expenditures were determined on the basis of 2001 average wholesale price. Hospitalization expenditures were determined on the basis of 2001 Medicare diagnostic related group reimbursement rates. Clinic expenditures were determined on the basis of 2001 Medicare current procedural terminology reimbursement rates. Results. Among the 635 patients, total annual expenditures for patients with CD4 + cell counts <50 cells/μL ($36,533 per patient) were 2.6-times greater than total annual expenditures for patients with CD4 + cell counts ≥350 cells/μL ($13,885 per patient), primarily because of increased expenditures for nonantiretroviral medication and hospitalization. Expenditures for highly active antiretroviral therapy were relatively constant at ∼$10,500 per patient per year across CD4 + cell count strata. Outpatient expenditures were $1558 per patient per year; however, the clinic and physician component of these expenditures represented only $359 per patient per year, or 2% of annual expenses. Health care expenditures for patients with HIV infection increased substantially for those with more-advanced disease and were driven predominantly by medication costs (which accounted for 71%-84% of annual expenses). Conclusions. Physician reimbursements, even with 100% billing and collections, are inadequate to support the activities of most clinics providing HIV care. These findings have important implications for the continued support of HIV treatment programs in the United States.
Women's treatment utilization and its relationship to childhood sexual abuse history and lifetime PTSD

A central issue in the substance abuse literature is whether a history of childhood sexual abuse (CSA) is a risk factor for poorer treatment outcomes. Although there is a strong belief that CSA is associated with increased substance abuse treatment utilization and relapse among women clients, most empirical evidence does not support this position. This study addresses this conundrum by exploring several possible explanations among a sample of women in substance abuse treatment. Unexpectedly, the results indicate that women with more severe histories of CSA were likely to have received less lifetime substance abuse treatment, although they were likely to have received more mental health treatment. In addition, the expected interaction between posttraumatic stress disorder (PTSD) status and CSA status and increased rates of both types of treatment was not found. However, participants with both PTSD and CSA concentrated on mental health treatment while those with only PTSD focused on substance abuse treatment.
Latina Women’s Experiences in a Stepfamily Education Course

This study highlights the experiences of low-income Latina women who participated in a nationally recognized, research-based stepfamily education program. From a multicultural feminist framework, interviews were conducted with 13 Latina women living in stepfamilies. They were asked, using a semistructured protocol, about their experiences of taking the course with other stepfamilies, the best part of the course, and anything positive and negative that resulted from participation. Participants identified improvements in parenting, couple, and overall family relationships. Improved communication, both as a learned skill and as a positive outcome, was reported most frequently in all areas of improved relationships. A small number of participants reported discomfort with “step” terms. Implications for providing education and individual and family therapy are provided.
Cyclosporine produces endothelial dysfunction by increased production of superoxide.

Vasoconstriction and hypertension are major side effects of cyclosporine therapy. The mechanism or mechanisms responsible for the vascular effects of cyclosporine are unclear. The vascular effects of cyclosporine may arise as a consequence of endothelial dysfunction induced by the agent. To test this possibility, we compared in vessels prepared in myographs endothelium-mediated relaxations of mesenteric resistance arteries of Wistar-Kyoto rats treated for 21 to 28 days with subcutaneous injections of cyclosporine (25 mg/kg per day), or vehicle. Endothelium-dependent relaxations in response to acetylcholine were impaired in arteries from cyclosporine-treated rats; the concentrations of acetylcholine required to produce 50% relaxation of norepinephrine activation (pD2) were 31.6 +/- 0.1 versus 5 +/- 0.1 nmol/L in control arteries (P < .05). Nitro-L-arginine produced comparable 10-fold decreases in sensitivity to acetylcholine in arteries from both rat groups, indicating that the relaxations were mediated by endothelium-derived nitric oxide. Acetylcholine-induced relaxations in cyclosporine-treated arteries were normalized by pretreatment of the arteries with superoxide dismutase (150 IU/mL; pD2, 3.6 +/- 0.1; P < .05); superoxide dismutase had no effect on relaxations in control arteries. SQ 29,548, an inhibitor of prostaglandin H2/thromboxane A2 receptors; H-7, an inhibitor of protein kinase C; and indomethacin did not alter relaxations in response to acetylcholine in either group of arteries. Cyclosporine-treated arteries were more sensitive than control arteries to nitroprusside, an agent that induces relaxation via nitric oxide (pD2, 1.3 and 6.2 mumol/L, respectively; P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Bayes inference in regression models with ARMA (p, q) errors

We develop practical and exact methods of analyzing ARMA(p, 4) regression error models in a Bayesian framework by using the Gibbs sampling and Metropolis-Hastings algorithms, and we prove that the kernel of the proposed Markov chain sampler converges to the true density. The procedures can be applied to pure ARMA time series models and to determine features of the likelihood function by choosing appropriate diffuse priors. Our results are unconditional on the initial observations. We also show how the algorithm can be further simplified for the important special cases of stationary AR(p) and invertible MA(q) models. Recursive transformations developed in this paper to diagonalize the covariance matrix of the errors should prove useful in frequentist estimation. Examples with simulated and actual economic data are presented. KPJ~ ~~ourls: Gibbs sampling; Metropolis-Hastings algorithm; Data augmentation; Time series; ARMA processes; Markov chain; Bayesian statistics
Cooperativity between Rad51 and C/EBP family transcription factors modulates basal and tat-induced activation of the HIV-1 LTR in astrocytes

Transcription of the HIV-1 genome is a complex event that requires functional and physical communication of cellular proteins that recognize the LTR sequence with viral proteins, most notably, Tat. Moreover, studies have revealed the ability of Tat to induce transcription of a variety of cellular genes whose products can affect the status of cells, thus contributing to the pathogenesis of AIDS. Recently, we demonstrated that expression of Tat in astrocytes and other neural cells leads to upregulation of Rad51, a major component of DNA repair via homologous recombination. The unscheduled upregulation of Rad51, in turn, has an impact upon the extent of chromosomal abnormalities that are seen in Tat-producing cells. Here, we asked whether an elevation in Rad51 levels influences the extent of viral gene transcription in astrocytic cells. Our results demonstrate that ectopic expression of Rad51 enhances the basal- and the Tat-induced transcription of the LTR promoter. This event requires cooperativity from the C/EBP family of transcription factors including C/EBPbeta and C/EBPbeta homologous protein (CHOP). Similar to Tat, we showed that Rad51 interacts with C/EBPbeta and augments its interaction with the DNA motif spanning nucleotides -120 to -94 of the LTR. Interestingly, Tat exhibited the capacity to augment the synergism between Rad51 and C/EBPbeta. Our results also demonstrate that the level of activation of the LTR by CHOP and Tat, either alone or together, is elevated in the presence of the SW1/SNF1 chromatin remodeling complex. These observations unravel a new pathway for Tat activation of the LTR that includes the positive feedback loop involving Rad51 and C/EBPbeta family proteins.
1,25-Dihydroxyvitamin D3 modulates colony-stimulating factor-1 receptor binding by murine bone marrow macrophage precursors.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] has been shown to be a potent agent for monocyte/macrophage differentiation in leukemic cell lines. This study examines the differentiational effects of 1,25-(OH)2D3 in authentic murine bone marrow immature uncommitted precursor cells collected by pretreatment of murine bone marrow with 5-fluorouracil (5- FU). Early precursor cells, collected 1 day after 5-FU treatment, are characterized by low expression of the colony-stimulating factor-1 (CSF-1) receptor and dependence on both CSF-1 and interleukin-1 for growth. Intermediate precursors were collected 5 days after 5-FU treatment and required either CSF-1 or interleukin-3 for growth. Intermediate precursors expressed relatively higher levels of the CSF-1 receptor. Addition of 1,25- (OH)2D3 to these populations inhibited proliferation, as measured by [3H]thymidine incorporation and soft agar colony assay. Furthermore, 1,25-(OH)2D3 caused a more rapid appearance of the CSF-1 receptor in early precursor cells in a dose...
Developing a community-academic health center: strategies and lessons learned

The purpose of this paper is to describe the process that Wright State University School of Medicine used to establish and build partnerships with various stakeholders in the City of Dayton, Ohio, to develop a community—academic health center. To ensure the success of this effort, it was important to identify key stakeholders in an inner city health center, and to establish effective partnerships with the stakeholders. Common goals were developed for the health center that met the expectations of all the partners. Application of the principles of Continuous Quality Improvement (CQI) led the group to define the set of common goals. The needs of the community were identified, and mechanisms to address the needs were developed using the tools of the CQI process. The programs emphasized health promotion by focusing on patient education and behavioral modification. Accepting the various priorities for the center enabled the School of Medicine to establish a quality community-based educational site for students...
EFL Learners' Incidental Acquisition of English Prepositions through Enhanced Extensive Reading Instruction

This study investigated whether enhanced extensive reading contributed to significant gains on the incidental acquisition of English prepositions. English as a Foreign Language (EFL) secondary scho...
Multi-feature audio-visual person recognition

We propose a high-performance low-complexity audio-visual person recognition framework suitable for on-line user authentication for various web-applications which delivers robustness against various types of imposter attacks by capturing face and speech dynamics from the video of the user. Instead of using the traditional frontal-face image, a set of compressed face profile vectors are extracted from multiple poses of the person. Similarly, multiple user-selected passwords are used to create robustness against imposter attacks. A novel FGRAM-CFD speech feature is proposed which captures the identity of the user from the speech dynamics contained in the password. The novel signal processing methods proposed here for speech and face feature-extraction led to high discriminative power of the combined audio-visual features. This allowed the classifier to remain simple, yet delivering a reasonably high performance at significantly low complexity as demonstrated by our trials on a 210-user audio-visual biometric database created for this research.
Effects of biological and non-biological immunomodulatory therapies on the immunogenicity of vaccines in patients with rheumatic diseases

Vaccinations are administered to patients to induce a protective immune response, resulting in immunological memory. Preventing infection through the use of vaccines is particularly important in immunocompromised and immunosuppressed individuals given their increased frequency and severity of infections relative to healthy individuals. Recent surveys show that the vaccination rate is still alarmingly low in patients with rheumatic disease. In this review we briefly discuss the different types of vaccines and then critically examine evidence related to vaccination efficacy in patients with autoimmune disease and the effects of immunomodulatory therapy, with an aim to provide guidance and optimize the administration of vaccines in such individuals.
Fixed dose combination abacavir/lamivudine in the treatment of HIV-1 infection.

The fixed dose combination of abacavir with lamivudine represents a new treatment option for patients infected with HIV. Fixed dose combination abacavir/lamivudine has the convenience of one pill and once-daily dosing. It achieves comparable suppression of plasma HIV RNA with the pill’s individual components dosed twice daily and with thymidine analogs combined with lamivudine. The combination is well tolerated, with the potential advantages of less lipoatrophy and fewer metabolic perturbations. However, the abacavir component may cause hypersensitivity reactions, which are reported in up to 8% of patients, and are potentially life threatening. Fixed dose combination abacavir/lamivudine should be considered as a viable treatment option for HIV-infected patients, particularly for those who have otherwise limited nucleoside reverse transcriptase inhibitor choices.
Substance Use and Early Marriage

Prior work indicates that substance use is related to adolescent marriage. We describe two different processes that may account for this relationship and hypothesize patterns of association that would be consistent or inconsistent with each. Using data from a study that followed west coast youth from 7th grade to young adulthood (N = 3324) we assessed the effects of cigarette alcohol and marijuana use in 7th and 10th grade on the probability of marriage prior to age 20. When gender race and SES were controlled cigarette use in adolescence but not other substance use was associated with early marriage. Low educational attainment and early unwed parenthood each uniquely mediated this association. These results suggest that the link between substance use and early marriage reflects a disposition toward risky or unconventional behavior not the judgment-impairing effects of drug and alcohol use. (authors)