cssi/SciSciGPT-SciSciNet huggingface dataset:
On Dissemination Time of Random Linear Network Coding in Ad-hoc Networks.

Random linear network coding (RLNC) unicast protocol is analyzed over a rapidly-changing network topology. We model the probability mass function (pmf) of the dissemination time as a sequence of independent geometric random variables whose success probability changes with every successful reception of an innovative packet. We derive a tight approximation of the average networked innovation probability conditioned on network dimension increase. We show through simulations that our approximations for the average dissemination time and its pmf are tight. We then propose to use a RLNC-based broadcast dissemination protocol over a general dynamic topology where nodes are chosen for transmission based on average innovative information that they can provided to the rest of the network. Simulation results show that information disseminates considerably faster as opposed to standard RLNC algorithm where nodes are chosen uniformly at random.
The interactive roles of nutrient loading and zooplankton grazing in facilitating the expansion of harmful algal blooms caused by the pelagophyte, Aureoumbra lagunensis, to the Indian River Lagoon, FL, USA

Abstract Confined to Texas, USA, for more than 20 years, brown tides caused by Aureoumbra lagunensis emerged in the Indian River Lagoon and Mosquito Lagoon, Florida, USA, during 2012 and 2013, affording the opportunity to assess whether hypotheses developed regarding the occurrence of these blooms are ecosystem-specific. To examine the extent to which top-down (e.g. grazing) and bottom-up (e.g. nutrients) processes controlled the development of Aureoumbra blooms in Florida, nitrogen (N) uptake, nutrient amendment, and seawater-dilution, zooplankton grazing experiments were performed and the responses of Aureoumbra and competing phytoplankton were evaluated. During the study, Aureoumbra comprised up to 98% of total phytoplankton biomass, achieved cell densities exceeding 2 × 106 cells mL−1, and contained isotopically lighter N compared to non-bloom plankton populations, potentially reflecting the use of recycled N. Consistent with this hypothesis, N-isotope experiments revealed that urea and ammonium accounted for >90% of N uptake within bloom populations whereas nitrate was a primary N source for non-bloom populations. Low levels (10 μM) of experimental ammonium enrichment during blooms frequently enhanced the growth of Aureoumbra and resulted in the growth rates of Aureoumbra exceeding those of phycoerythrin-containing, but not phycocyanin-containing, cyanobacteria. A near absence of grazing pressure on Aureoumbra further enabled this species to out-grow other phytoplankton populations. Given this alga is generally known to resist zooplankton grazing under hypersaline conditions, these findings collectively suggest that moderate loading rates of reduced forms of nitrogenous nutrients (e.g ammonium, urea) into other subtropical, hypersaline lagoons could make them susceptible to future brown tides caused by Aureoumbra.
Bone physiology and therapeutics in chronic critical illness

Modern medical practices allow patients to survive acute insults and be sustained by machinery and medicines for extended periods of time. We define chronic critical illness as a later stage of prolonged critical illness that requires tracheotomy. These patients have persistent elevations of inflammatory cytokines, diminished hypothalamic-pituitary function, hypercatabolism, immobilization, and malnutrition. The measurement of bone turnover markers reveals markedly enhanced osteoclastic bone resorption that is uncoupled from osteoblastic bone formation. We review the mechanisms by which these factors contribute to the metabolic bone disease of chronic critical illness and suggest potential therapeutics.
Computer Controlled Technique Factors In Diagnostic Radiology

One of the objectives of quality control in diagnostic radiography is the ability to select the technique factors which will produce a desired optical density on the final radiograph. This density is a function of several variables. Among these are x-ray target material, target angle, kV and the voltage wave form, mAs, geometry, patient thickness, field size, properties of the scatter reduction devices and type of screen film systems and processing employed. These variables have been modelled into a computer program. The program calculates technique factors of kV and mAs to give a desired film density for a given set of the other parameters. Application of the results of the theoretical calculations to experimental studies utilizing phantoms resulted in an optical density within 9% of the expected value. Results of the theoretical and experi-mental studies have been presented. Possible application of computer control in diagnostic radiography will be discussed.
Knowledge, perceptions, and mammography stage of adoption among older urban women☆

Introduction: Mammography is under-used among older minority women. Identifying differences in their attitudes and beliefs by stage of mammography adoption will guide interventions for these under-studied and under-served women. Methods: A total of 253 older urban women were interviewed, assessing breast cancer knowledge, perceived mammography benefits and barriers, stage of mammography adoption, personal experience with breast cancer, physical and cognitive functioning, smoking status, source and frequency of regular medical care, and demographics. Analyses compared scale scores and individual items by stage of mammography adoption. Multivariate analysis used linear and logistic regression with stepwise model selection. Results: Sample mean age was 72.5 years; 88% were African American. About half (52%) had had a mammogram within the past 2 years (i.e., action stage of mammography adoption). Of the rest, 16% were thinking about having a mammogram in the next 6 months (contemplators) and 32% were not thinking about having a mammogram within 6 months (precontemplators). Knowledge and benefit scores were lowest for precontemplators. Overall barrier scores were highest for precontemplators (P < .001), but contemplators were most likely to worry about finding a lump (P < .05). Lower perceived barriers, provider recommendation, regular medical care somewhere other than a private physician's office, and age <75 years were independently associated with more favorable mammography stage (R2 = .47). Conclusion: Mammography interventions for older urban women should combine provider recommendations with barrier-reducing interventions. Knowledge is associated with mammography contemplation, but barriers may affect whether contemplation leads to action. Precontemplators may need explanation of the rationale for screening; contemplators may need intervention to assuage fears.
Neither History nor Freedom Will Absolve Us: On the Ethical Dimensions of the Poetry of Lesego Rampolokeng

Lesego Rampolokeng is a poet and writer whose emergence on the South African literary landscape in the late 1980s and early 1990s was marked by the exigencies of the “interregnum” and the “transiti...
Configuration Interaction in the 4f 3 Configuration of Pr iii

The energies of the 37 observed levels of the 4f3 configuration of Pr iii have been calculated with an rms deviation of ±29 cm−1 by use of 13 adjustable parameters, including 5 parameters which account for nonlinear configuration-interaction effects. The physical significance of the nonlinear parameters is discussed in terms of the relative roles of various mechanisms of configuration interaction.
Density fluctuations in molten salts. I. Inelastic neutron scattering from liquid RbBr

The density fluctuations in molten salts are being investigated with a combination of neutron-scattering and computer-simulation techniques. In this paper results are given for measurements of the coherent inelastic neutron scattering from molten RbBr at 986 K, in the wave-vector range $1\ensuremath{\lesssim}Q\ensuremath{\lesssim}7$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$. In view of the similarity between the ${\mathrm{Rb}}^{+}$ and ${\mathrm{Br}}^{\ensuremath{-}}$ ions with regard to size, mass, and neutron scattering length, the scattering function measured in these experiments closely reflects the behavior of the number density fluctuations in the melt, regardless of ion type.
Ignitability and mixing of underexpanded hydrogen jets

Abstract Reliable methods are needed to predict ignition boundaries that result from compressed hydrogen bulk storage leaks without complex modeling. To support the development of these methods, a new high-pressure stagnation chamber has been integrated into Sandia National Laboratories’ Turbulent Combustion Laboratory so that relevant compressed gas release scenarios can be replicated. For the present study, a jet with a 10:1 pressure ratio issuing from a small 0.75 mm radius nozzle has been examined. Jet exit shock structure was imaged by Schlieren photography, while quantitative Planar Laser Rayleigh Scatter imaging was used to measure instantaneous hydrogen mole fractions downstream of the Mach disk. Measured concentration statistics and ignitable boundary predictions compared favorably to analytic reconstructions of downstream jet dispersion behavior. Model results were produced from subsonic jet dispersion models and by invoking self-similarity jet scaling arguments with length scaling by experimentally measured effective source radii. Similar far field reconstructions that relied on various notional nozzle models to account for complex jet exit shock phenomena failed to satisfactorily predict the experimental findings. These results indicate further notional nozzle refinement is needed to improve the prediction fidelity. Moreover, further investigation is required to understand the effect of different pressure ratios on measured virtual origins used in the jet dispersion model.
The computation of the velocity fields in mechanically agitated melts for turbulent and non-newtonian regimes

A mathematical model is developed to describe the behavior of melts, agitated by a flat blade impeller, mounted on a rotating shaft. The model was verified by testing against experimental results, obtained using water, where the flow was turbulent. However, the main objective of the work was to describe the velocity fields produced in melt-solid slurries, which are non Newtonian. By using a power-law expression for the viscosity, it was found that these systems can be adequately agitated using mechanical stirring. This is in contrast to previously published results, which indicate that by using conventional electromagnetic stirring arrangements, it would be difficult to agitate melt-solid slurries, particularly at high solid loading levels.
N-Arylalkyl Pseudopeptide Inhibitors of Farnesyltransferase

Inhibitors of Ras protein farnesyltransferase are described which are reduced pseudopeptides related to the C-terminal tetrapeptide of the Ras protein that signals farnesylation. Reduction of the carbonyl groups linking the first three residues of the tetrapeptide leads to active inhibitors which are chemically unstable. Stability can be restored by alkylating the central amine of the tetrapeptide. Studies of the SAR of these alkylated pseudopeptides with concomitant modification of the side chain of the third residue led to 2(S)-(2(S)-?[2(S)-(2(R)-amino-3-mercaptopropylamino)-3(S)- methylpentyl]naphthalen-1-ylmethylamino?acetylamino)-4 -methylsulfany lbutyric acid (11), a subnanomolar inhibitor. The methyl ester (10) of this compound exhibited submicromolar activity in the processing assay and selectively inhibited anchorage-independent growth of Rat1 cells transformed by v-ras at 2.5-5 microM.
The Utility of a DSM-IV-Referenced Screening Instrument for Attention-Deficit/Hyperactivity Disorder:

In this study, we examined the clinical utility of the ADHD Symptom Checklist-4 (ADHD-SC4), a screening measure for attention-deficit/hyperactivity disorder (ADHD). The objectives were to assess the scale's concurrent, differential, and criterion validity. Participants were 103 children between 5 and 17 years old referred to a child psychiatry outpatient service and diagnosed as having a variety of emotional and behavioral disorders. Children were assessed with a battery of standardized assessment instruments and clinical interviews. Clinical diagnoses were verified with an operationalized diagnostic criteria procedure. Parents and teachers completed several rating scales for each child, including the ADHD-SC4, the Child Behavior Checklist (CBCL), the Teacher Report Form (TRF), and the IOWA Conners Teacher's Rating Scale. Findings support the internal consistency and validity of the ADHD-SC4 as a screening instrument forADHD, oppositional defiant disorder, and aggressive behavior. Sensitivity forADHD was ...
Solving sequential knapsack problems

We give an O(n log n) algorithm for solving sequential knapsack problems, whose bottleneck operation is sorting the ratios c"j/a"j; otherwise the running time is O(n). This is used to compute a better bound than z"L"P for the general 0-1 knapsack problem in linear time after sorting the ratios c"J/a"j.
Health Literacy in College Students

Abstract Objective: The purpose of this study was to assess the health literacy levels, and the potential importance of healthy literacy, of college students. Participants: Courses were randomly selected from all upper level undergraduate courses at a large Research I university to obtain a sample size of N = 399. Methods: During the 2007–2008 school year, students were administered the Test of Functional Health Literacy (TOFHLA), which assessed both numeracy and reading comprehension utilizing real-life health care materials. The numeracy scale (n = 17) assessed understanding of prescription labels, appointment slips, and glucose monitoring using actual hospital forms and labels for prescription vials. Ten prompts were given, and participants had to answer quantitatively. The reading comprehension scale (n = 50) assessed understanding of health care texts through 3 reading passages, including instructions for preparation for an upper gastrointestinal (GI) series, Medicaid patient rights and responsibilit...
Rapidly progressive osteoarthritis: Biomechanical considerations

An underlying hypothesis for rapid cartilage loss in patients with osteoarthritis (OA) is that perturbation from normal joint mechanics produces locally high biomechanical strains that exceed the material properties of the tissue, leading to rapid destruction. Several imaging findings are associated with focally high biomechanical forces and thus are potential candidates for predictive biomarkers of rapid OA progression. This article focuses on 3 aspects of knee biomechanics that have potential magnetic resonance imaging correlates, and which may serve as prognostic biomarkers: knee malalignment, meniscal dysfunction, and injury of the osteochondral unit.
Effect of market access on sharing practices within two Huaorani communities

Abstract One explanation for meat sharing within hunter–gatherer communities is that sharing reduces variance in consumption that results from unpredictable harvests. If this food-risk reduction is the primary reason for sharing, then a good alternative to sharing would be selling meat in a market and using the cash to buy storable foods. We analyze the effect of market access on sharing behavior in two Huaorani communities in the Ecuadorian Amazon in order to test the hypothesis that hunters share mainly to reduce food risk. If this hypothesis is correct we expect to find that hunters are selling meat that would have otherwise gone into sharing networks. The alternative hypothesis is that sharing has multiple benefits, in addition to risk reduction, making sharing and selling imperfect substitutes. We find evidence that households use the market to reduce food risk, but that the amount of meat a hunter sells has no relationship with sharing intensity. Rather, the likelihood of selling meat simply increases with hunting returns. The results suggest that selling meat has lower expected benefits than sharing and so hunters first satisfy their sharing requirements and then sell any excess meat.
AN ELEMENTARY TEST OF THE NORMAL 2PL MODEL AGAINST THE NORMAL 3PL ALTERNATIVE

A simple score test of the normal two-parameter logistic (2PL) model is presented that examines the potential attraction of the normal three-parameter logistic (3PL) model for use with a particular item. Application is made to data from a test from the Praxis™ series. Results from this example raise the question whether the normal 3PL model should be used routinely in preference to the normal 2PL model unless evidence exists that a substantial gain in description of data is achieved.
Single Electron in a Random Potential and a Strong Magnetic Field

Abstract An electron in an infinitely extended plane is subject to a strong transverse magnetic field. The degenerate states pertaining to a single Landau level are coupled by a random potential. We develop a matrix algorithm that maps this problem onto a path-integral problem in two dimensions. For a class of random potentials, we calculate the average level density for an arbitrary Landau level, and we show that the problem differs from the localization problem without magnetic field only by the presence of the topological term. The coefficient multiplying this term is given explicitly.
DNA Helical Instability Facilitates Initiation at the SV40 Replication Origin

Previous analysis of mutations in bacterial and yeast replication origins has identified a genetic component, termed a DNA unwinding element (DUE), whose intrinsic helical instability is essential for origin function. For the SV40 replication origin, we show here that the early palindrome (EP) and A + T-rich (AT) domains both exhibit helical instability, despite their dissimilar A + T compositions. To test the possible contribution of helical instability to SV40 origin function, the relationship between helical stability of mutant origin sequences and their known origin activity in vitro and in vivo was examined. Origin activity correlates inversely with the helical stability of mutations within the EP domain but not the AT domain or the T-antigen binding domain. The quantitative correlation holds for four different measures of origin activity determined in vitro and in vivo. An even better-correlated collection of mutations was found in a specific portion of the EP domain. This specific EP subdomain coincides with the sequence known to be strand-separated after T-antigen binds the origin in vitro and with the origin of bidirectional replication in vivo. Our analysis of origin mutations indicates that the helical instability of the specific EP subdomain is required to facilitate T-antigen-induced melting and the initiation of DNA replication. The sensitivity of the required EP subdomain to mutations that stabilize the DNA helix defines the DUE of the SV40 replication origin.
Early diagnosis and survival of ruptured abdominal aortic aneurysms

The hospital records of patients treated with ruptured abdominal aortic aneurysm in a recent 5-year period were reviewed to collect data on factors which may be associated with mortality. Overall mortality was 62%. Patients with intraperitoneal rupture had a higher mortality (97%) than patients with retroperitoneal rupture (25%). Patients at increased risk were older than 80 years, presented with syncope, experienced a short duration of symptoms prior to emergency department (ED) arrival, had initial systolic blood pressure less than 90 mm Hg, and/or initial hemoglobin level less than eight on arrival at the ED and delay in beginning surgery. Multivariate analysis demonstrated preoperative blood pressure, preoperative hemoglobin, presence of syncope, and the amount of blood transfused were largely reflections of the type of rupture and had only slight independent relationship to mortality. The authors concluded that treating emergency physicians and surgeons have little control over the most important risk factors for mortality after aneurysm rupture, but may improve the prognosis by expediting diagnosis in the ED and surgical therapy.
Experimental cerebral ischemia produced by extracranial vascular injury: protection with indomethacin and prostacyclin.

To determine whether the production of brain ischemia is modified by antiplatelet agents administered at the time of extracranial endothelial injury, we modified a four-vessel occlusion rat model so that an electrogenic platelet thrombus in one carotid artery produced cerebral ischemia. DC current was passed through an anode around the left carotid artery of 11 rats with preoccluded vertebral and contralateral carotid arteries. Five of six untreated rats became unresponsive because of carotid occlusion and resultant cerebral ischemia; none of five animals pretreated with indomethacin and infused with prostacyclin (PGI 2 ) were clinically affected. Light-and electronmicroscopic studies showed arterial platelet-fibrin thrombi and ischemic brain damage in untreated rats. All rats had received radiolabeled platelets; radioactivity was increased in the electrogenically injured left carotid arteries from treated and untreated rats, but counts were reduced by more than 80% in indomethacin/ PGL 2 -treated rats ( p
Troponin I after cardiac surgery and its implications on myocardial protection, outcomes, and cost

Abstract Background Myocardial acidosis during cardiac surgery and postoperative troponin I are markers of myocardial damage that have been shown to predict adverse outcomes. We investigated the relationship between troponin I and myocardial tissue pH, patient outcomes, and cost. Methods Data were prospectively collected on 205 cardiac surgery patients. Troponin I was sampled upon arrival to the intensive care unit (ICU) and every 6 hours thereafter for 24 hours. The lowest pH encountered during aortic cross clamp (LpH) was related to postoperative troponin I on the multivariate level. Multivariate models were constructed to predict adverse events (AE) and cost. Results LpH was an independent inverse determinant of postoperative troponin I (P = .0067). Troponin I and its interaction with LpH were multivariate predictors of AE (P = .0012; .0001;odds ratio = 6.9, 10.2, respectively). Troponin I independently predicts surgical ICU (SICU) cost (P = .0256). Conclusion Postoperative troponin I elevation reflects intraoperative myocardial acidosis and damage. The strong relationship between troponin I, AE, and cost indicates the damage incurred is clinically and economically relevant. Strategies to ameliorate intraoperative myocardial tissue acidosis will decrease troponin I release, subsequent AE, and associated costs.
Pharmacokinetics of an indinavir-ritonavir-fosamprenavir regimen in patients with human immunodeficiency virus.

Constructing an effective therapeutic regimen for antiretroviral-experienced patients with persistent viremia despite ongoing therapy is a nagging challenge in the management of human immunodeficiency virus (HIV) infection. Although several new classes of antiretroviral agents with activities against multidrug-resistant HIV-1 viral strains are in the developmental pipeline, the antiviral activities of these newer drugs are optimal in the presence of an active background antiretroviral therapy.1, 2 Therefore, the need exists to continue to identify combinations of agents among currently approved antiretroviral drugs that are pharmacokinetically compatible, safe, and potentially active against multidrug-resistant HIV strains. Ritonavir-boosted dual–protease inhibitor regimens are used as a component of a salvage combination therapy.3-6 By inhibiting the cytochrome P450 (CYP) 3A4 isoenzyme, ritonavir enhances the pharmacokinetics of protease inhibitors to levels that could produce sustained virologic suppression for viral strains with moderate phenotypic resistance similar to ritonavir pharmacoenhancement in the naive setting.7, 8 Furthermore, pharmacoenhancement of two or more active protease inhibitors with nonoverlapping resistance mutation patterns may result in a higher genetic barrier to resistance and possibly synergistic activity against HIV. For these reasons, a ritonavir-enhanced indinavir-amprenavir combination appears attractive for salvage therapy in HIV infection. Fosamprenavir, a prodrug of amprenavir, is rapidly hydrolyzed to its parent form by cellular phosphatases in the gut epithelium during absorption.9 Not only are the plasma concentrations of indinavir and amprenavir enhanced by ritonavir,10 the two agents have nonoverlapping primary resistance patterns.11, 12 However, our knowledge of limiting drug-drug interactions that occur with a number of boosted double–protease inhibitor combinations13-15 makes it essential to evaluate the pharmacokinetics of these regimens before their clinical use. In this study, we evaluated the pharmacokinetic interaction of a ritonavir-boosted indinavir-fosamprenavir combination among HIV-infected patients. If pharmacokinetically compatible, a ritonavir-boosted indinavir-fosamprenavir regimen could be a suitable adjunct in salvage therapy of highly treatment-experienced HIV-infected patients with multidrug-resistant viruses.
“Truthing it in Love”: Henry Ward Beecher's Homiletic Theories of Truth, Beauty, Love, and the Christian Faith

The preacher Henry Ward Beecher was once the most famous man in America. Although he is now often unnoticed, history has attested to Beecher's influence on important elements of contemporary rhetorical style and homiletic theology. In his largest pronouncement on the theory of preaching, his Yale lectures, Beecher set out a theory of preaching that declared the goal of preaching to be a core transformation of the listeners through an aesthetic connection to the Divine presence. As a part of this process, Beecher argued in favor of an ecumenically Christian form of “taste” that would sensitize the audience to the existence of a new kind of knowledge: a divinely inspired linkage of logos and pathos that Beecher referred to as the Doctrine of Love.
Electron Paramagnetic and Nuclear Double Resonance of F + Centers in BeO Single Crystals

Single crystals of BeO which have been irradiated with neutrons show an EPR spectrum with partially resolved hyperfine structure. An ENDOR study of the hyperfine interaction leads to the conclusion that the spectrum arises from centers which consist of an electron trapped at an oxygen vacancy surrounded by four Be nuclei. The measured hyperfine interaction constants are: $\frac{{\mathrm{A}}_{\ensuremath{\perp}}}{h}=10.3$ MHz, $\frac{{A}_{\ensuremath{\parallel}}}{h}=16.4$ MHz, and $\frac{({e}^{2}qQ)}{h}=1.1$ MHz for the Be nuclei not on the $c$ axis; and $\frac{{A}_{\ensuremath{\perp}}}{h}=4.2$ MHz, $\frac{{A}_{\ensuremath{\parallel}}}{h}=9.2$ MHz, and $\frac{({e}^{2}qQ)}{h}=1.5$ MHz for the nuclei along the $c$ axis. These values lead to ${|\ensuremath{\psi}({r}_{\mathrm{Be}})|}^{2}=0.13\ifmmode\times\else\texttimes\fi{}{10}^{24}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ for the electron wave function at the $c$-axis nuclei, and ${|\ensuremath{\psi}({r}_{\mathrm{Be}})|}^{2}=0.06\ifmmode\times\else\texttimes\fi{}{10}^{24}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ for the nonaxial nuclei. The measured $g$ value for H parallel to the $c$ axis is 2.0030.
Variation of the thorium to uranium ratio in rain: Thorium-230 chronology of the eruptions of Mt. St. Helens and El Chichón volcanoes

Principles of the thorium-230 dating method were applied to the study of thorium and uranium isotopes in a series of rain samples collected at Fayetteville (36°N, 94°W), Arkansas, since 1980. The results indicate that the rainwater contains volcanic ash materials with a wide variety of ages, which were blown up onto the upper stratosphere from the 18 May 1980 eruption of Mount St. Helens and the 28 March 1982 eruption of E1 Chichon. These volcanic materials seem to have stayed airborne for a number of years and profoundly affected the global atmospheric inventories of thorium and uranium isotopes.
A radiographic technique for demonstrating the causes of persistent nasality in patients with pharyngeal flaps

Summary Videofluoroscopy in multiple views was employed in a study of the nasopharynx in a series of patients with persistent velopharyngeal incompetence following pharyngeal flap surgery. This technique permits the visualisation of specific anatomical and physiological defects in the closure mechanism accounting for velopharyngeal incompetence. Incompetent closure mechanisms were observed to result from a variety of abnormalities of flap width, horizontal position and vertical level in relationship to the region of greatest lateral nasopharyngeal wall movement.
Feedback-controlled ion beam system for nanoporous membrane fabrication

We report the design of an ion beam bombardment chamber that enables the controlled fabrication of nanometer-sized holes in solid-state materials. The instrument employs a beam of MeV gold ions that impinges on a polymer membrane whose properties are to be modified. The instrument uses an innovative feedback control for the crafting of structures that define a hole in the film through which a trapped gas is permitted to leak and be monitored by a Residual Gas Analyzer. The polymer thin film was fixed as a cover window to a He gas filled chamber and then exposed to a uniformly scanned gold MeV ion beam masked to define the exposed area. The gas leak rate through the fabricated pores is a real-time measure of the total area of the pores produced and is used as the feedback signal to trigger the bombardment process when the desired nanopore size is obtained. Applications of the instrument, as a fabrication tool for nanopores, have been recently reported for nanoporous membranes studies.
Proton-mediated dynamics of the alkaline conformational transition of yeast iso-1-cytochrome c.

The kinetics of the alkaline conformational transition of a Lys 73→His variant of iso-1-cytochrome c have been investigated using pH jump stopped-flow methods to probe the nature of the ionizable “trigger” group for this conformational change. This mutation moves the pKa of the ligand replacing Met 80 from about 10.5 to approximately 6.6 and has unmasked two other ionizable groups, besides the ligand replacing Met 80, that modulate the kinetics of this process. The results are discussed in terms of the impact of ionization equilibria on protein folding mechanisms.
Inhibition of anaerobic dissimilation of pyruvate by phenylpyruvate.

Abstract 1. 1. Phenylpyruvate acts as a competitive inhibitor of the anaerobic dissimilation of pyruvate by Aerobacter aerogenes . Other anaerobic dissimilations were inhibited to a lesser degree by phenylpyruvate. Phenylpyruvate may be dissimilated by the dismutation reaction and, of course, there is no inhibition of this reaction. No inhibition was observed of the two aerobic reactions studies. 2. 2. The value of the enzyme-substrate dissociation constant is of the order of 1.59 × 10 −1 moles/1.; the dissociation constant of the enzyme-inhibitor complex is of the order of 8.46 = 10 −4 moles/1.
ArePlaque angiogenesis and atherosclerosis

Therapeutic angiogenesis trials refer to the stimulation of collateral arterioles and new vascular conduits to perfuse ischemic myocardium and limbs. Atherosclerotic lesions responsible for vascular occlusions themselves are associated with angiogenesis within the vessel wall. Plaque neovascularization is comprised of a network of capillaries that arise from the adventitial vasa vasorum and extend into the intimal layer of atherosclerotic lesions and other types of vascular injury. The functions of these plaque capillaries are proposed to be important regulators of plaque growth and lesion instability. The development of agents that are positive and negative regulators of angiogenesis may have potential therapeutic implications in the progression and acute manifestations of atherosclerosis. This review focuses on the role of plaque angiogenesis in atherosclerosis and discusses the potential therapeutic applications of angiogenesis inhibitors in this disease.
Ventilatory responses to CO2 in the chicken: intrapulmonary and systemic chemoreceptors

The independent effects of pulmonary and arterial Pco2 on respiratory amplitude (RA) and respiratory frequency (f) were studied in unidirectionally ventilated chickens anesthetized with phenobarbital (160 mg · kg−). Pulmonary Pco2 was set by the level of PIco2 ventilating the vascularly isolated right lung (VIL), whereas the systemic arterial Pco2 was set by the level of Pco2 ventilating thedenervated left or gas exchange lung (GEL). The following results were obtained: 1. 1) Increasing the PIco2 to the VIL from 0 to 35 torr and maintaining Paco2 constant at 29 lorr increased RA from apnea to 76% of the animals maxima] hypercapnic response and decreased f: further increases in PIco2 to VIL had only minimal effects on RA and f. 2. 2) Increasing Paco2, from 19 to 61 torr and maintaining pulmonary Pco2, constant increased RA and decreased f; further increases in Paco2, had only slight effects on RA and f. It is concluded that (1) intrapulmonary CO2, -sensitive chemoreceptors mediate a pulmonary chemoreflex and can dominate the control of RA during hypocapnic conditions, and (2) systemic CO2-sensitivc chemoreceptors dominate the control of RA during hypercapnic conditions. It is suggested that the intrapuimonary chemoreceptors may act as a sensory system which plays a pertinent role in the regulation of parabronchial ventilation.
Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy

Abstract Purpose: Larger prostate gland volumes have been associated with long-term urinary morbidity in prostate interstitial radiation therapy utilizing ultrasound image guidance technique. This study was performed to identify the clinical and technical predictors of acute urinary retention following magnetic-resonance (MR)-guided prostate interstitial brachytherapy. Methods and Materials: Fifty patients underwent MR-guided prostate brachytherapy between December 1997 and March 1999. Patient selection was limited to men with stage T1cNXM0 disease, PSA of less than10 ng/mL, biopsy Gleason score not more than 3 + 4, and endorectal coil MR stage T2 disease. Dosimetry plans were developed in the operating room and 125 Iodine sources were implanted using MR real-time guidance. The peripheral zone (PZ) of the prostate gland was defined as the clinical target volume (CTV) and the minimum prescribed dose to the CTV was 137 Gy. The volumes of the PZ, transition zone (TZ), and total prostate gland volume were also determined by MR. Individual source strength ranged from 0.35 to 0.54 μGym 2 /h (NIST 99, median 0.46 μGym 2 /h) and the total implanted activity ranged from 17.0 to 43.1 mCi (median, 28.1 mCi) using 43–120 seeds (median, 79). The seeds were placed using MR-compatible biopsy needles (14–28, median, 19). Results: The ability of clinical (MR defined prostate, PZ, and TZ volumes) and technical (number of catheters, number of seeds implanted, and total activity) factors to predict AUR for 50 men undergoing MR-guided prostate interstitial brachytherapy were evaluated using univariable and logistic regression multivariable analyses. Six men (12%) experienced AUR within 24 h after removal of the Foley catheter subsequent to prostate brachytherapy. The total number of seeds ( p = 0.05), MR determined prostate volume ( p p p Conclusion: Benign prostatic hyperplasia (BPH) resulting in an enlarged TZ volume, is the most important predictor of AUR following MR-guided prostate interstitial radiation therapy. Although AUR was significant (60%) in men with moderate BPH (TZ volume ≥ 50 cc), it was also self-limiting.
Studies on the secretion of blood group substances. II. Observations on the red cell phenotype Le(a-b-x-).

Salivas from 35 type Le(a-b-x-) subjects were tested for Lea,Leb, Lex, A, B and H substances by both manual and automated quantitative hemagglutination inhibition methods. For comparison, similar data were gathered from 226 Lewis positive adults. Among the 13 Ma-bx-) nonsccretors, 7 had small quantities of salivary Lea activity and 11 had low concentrations of salivary Lex by manual methods. None showed any salivary Lebactivity. By the automated method, low concentrations of Leaactivity were demonstrable in 12. Among the 22 Ma-b-x-) -tors, 6 had minute quantities of salivary Lewis activity, mainly Leb. The Leb activity could not represent cross reactivity with H substance because most of those subjects with the highest H activities had no Leb activity. Our quantitative studies show, when salivary Lewis activity is present in individuals whose red cells era type Ma-bx-), that the activity is much lower in comparison with individuals whose red cells are Lewis positive. Thus, based on quantitative salivary studies, it is possible to distinguish between Lewis positive (Len and Lewis negative (le/le) individuals. These observations suggest that the le gene is not a completely inert allele but that it governs the biosynthesis of serologically active substances. The Ze gene can be regarded as an inefficient Le which produces exactly the same products in a qualitative way as the Le gene but quantitatively far less. Another possibility is, as recently suggested, that the le gene actually governs the biosynthesis of distinct products Lec and Led and that salivary Lea and Leb activities among Lewis negative subjects represent cross reactivity with these products.
Perspective: Quantum or classical coherence?

Some coherence effects in chemical dynamics are described correctly by classical mechanics, while others only appear in a quantum treatment—and when these are observed experimentally it is not always immediately obvious whether their origin is classical or quantum. Semiclassical theory provides a systematic way of adding quantum coherence to classical molecular dynamics and thus provides a useful way to distinguish between classical and quantum coherence. Several examples are discussed which illustrate both cases. Particularly interesting is the situation with electronically non-adiabatic processes, where sometimes whether the coherence effects are classical or quantum depends on what specific aspects of the process are observed.
Is the enemy from within

Andersson et al. conducted a population-based case-control study to assess the relationship between appendectomy and the development of ulcerative colitis (UC). All patients in Sweden with hospital discharge diagnoses that included appendectomies between 1964 and 1993 were identified from the national Inpatient Register. Only those who were younger than 50 at the time of surgery were included. Patients were divided into groups according to their discharge diagnoses, which included perforated appendicitis, nonperforated appendicitis, nonspecific abdominal pain, and mesenteric lymphadenitis. Community controls without histories of appendectomies were matched in a 1:1 fashion based on age, sex, and township of residence. Patients were excluded if they had diagnoses of UC at or before appendectomies, UC was diagnosed within 1 yr after the appendectomy, or there was less than 1 yr of follow-up. Follow-up was done until the diagnosis of UC was made, death, or the study end of December 31, 1995. The diagnosis of UC was established by referencing the same Inpatient Register. A total of 212,963 cases of appendicitis with similar controls were identified, with a follow-up of >5 million person-years. Seven hundred fourteen patients were diagnosed with UC. Overall, patients with histories of appendectomies had a significantly lower incidence of UC, with an incidence rate ratio (IRR) of 0.74 (95% CI = 0.64–0.86). This relationship of a protective effect was true when the discharge diagnosis was acute appendicitis (IRR = 0.75, 95% CI = 0.62–0.87) or mesenteric lymphadenitis (IRR = 0.48, 95% CI = 0.27–0.83), but for only those patients younger than 20. A discharge diagnosis of nonspecific abdominal pain was not associated with a protective effect. Cox proportional-hazards regression modeling resulted in similar findings, with the addition of female sex as a significant covariate to the model. A separate analysis was performed for patients who had surgery before the age of 20 and those 20 or older to assess the relation in the two age groups. Patients who underwent surgery for appendicitis before the age of 20 had a lower risk of UC than controls (IRR = 0.42, 95% CI = 0.31–0.57); those older than 20 had the same risk as controls. The authors concluded that in this large population-based study they were able to confirm an inverse relation between appendectomy and UC. This relation was confined to appendectomy in young patients with inflammation of the appendix or mesenteric lymph nodes.
Iodine 131 total body scan—extrathyroidal uptake of radioiodine

This 30-year-old male, with a history of "total thyroidectomy" in June 1974 for angioinvasive follicular papillary carcinoma, was maintained on a suppressive dose of L-thyroxine. In August 1981 he was referred to the Nuclear Medicine Service for evaluation of a 1 cm • 1 cm soft node palpable in the right submandibular region. A thyroid scan with 200 ~zCi of 1251 demonstrated significant iodine uptake in the thyroid bed (24hour uptake; 14.6%) with visualization of what appeared to be the upper portion of right lobe and the pyramidal lobe. In addition, extrathyroidal activity was seen in the right submandibular and submental regions. A total body scan 7 days after an ablative dose of 1311 (169 mCi) showed additional focal activity in the right hilum, both lung bases and the liver posteriorly (Fig 1).
Mucocele after endorectal pull-through for imperforate anus

This report documents a patient with imperforate anus in whom an endorectal pull-through with incomplete excision of the macroscopic mucosa led to the formation of a 1,500 mL mucosal lined pelvic mucocele, obstructing both the rectum and ureter. All macroscopic mucosa should be removed during endorectal pull-through.
Late axillary artery thrombosis in patients with occluded axillary-femoral bypass grafts

Abstract The axillary-femoral bypass graft is an alternative to direct anatomic procedures for patients with aortoiliac occlusive disease. Touted for its low morbidity and mortality rates, with corresponding improved patency rates, this extra-anatomic procedure has been considered safe and effective. Noncompromising upper extremity ischemia and one case of upper extremity loss, associated with early graft thrombosis, have been reported previously. This article describes two cases of late axillary artery thrombosis, occurring 4 and 6 months after graft thrombosis, which severely jeopardized the viability of the ipsilateral upper extremity. Experience with these patients has shown that a thrombosed axillary-femoral bypass graft may jeopardize the viability of the ipsilateral upper extremity many months after its failure. The absence of information in the literature regarding this complication suggests this is a rare complication of thrombosed axillary-femoral grafts. (J VASC SURG 1985;2:285-7.)
Co-60 and neutron irradiation of MOS-controlled thyristors

The authors report changes in MOS-controlled thyristor (MCT) performance caused by irradiation with fast neutrons (E>1 MeV) and with Co-60 gamma rays. The results are significant because the MCT is representative of a growing class of power devices that combine bipolar and field-effect-transistor (FET) technologies and because MCTs are being considered for use in systems that must survive exposure to radiation. The MCTs tested, which were designed to hold off 400 V and carry 50 A, were operable with +or-10-V control voltages after they received a total dose of 1 Mrad(Si), but they could not be turned on after exposure to 1E12 n/cm/sup 2/. This observation is consistent with calculations of the effects of neutron fluence on minority-carrier transport in the MCT. The observed shifts with total dose of V/sub on/ and, at least in part, of V/sub bias/ are consistent with the known behavior of p-channel and n-channel polysilicon gate FETs. >
ET-34HIGHLY SELECTIVE HSV VIROTHERAPY FOR TREATMENT OF GLIOBLASTOMA

Glioblastoma Multiforme (GBM) is an aggressive brain cancer for which there is no effective treatment. Oncolytic HSV vectors (oHSV) are attenuated lytic viruses that have shown promise in the treatment of human GBM models in animals. Although proven safe for treatment of GBM in patients, oHSVs efficacy has been limited, a consequence of poor intra-tumoral virus replication and spread. To counter these limitations, we have developed oHSVs whose selective replication in GBM cells does not rely on defective genes. This was accomplished by (i) full retargeting of oHSV to utilize the epidermal growth factor receptor (EGFR) for infection of human GBM tumor cells and (ii) further vector engineering to modify the essential HSV immediate early gene (ICP4) for sensitivity to repression by the microRNA mir-124. Mir-124 is highly expressed in neurons but virtually absent in GBM and highly conserved among different species. The mir-124-regulated vector was unable to replicate in nude mice following intracranial inoculation supporting vector safety and was shown to be effective (50-60% long term survival) in the treatment of human GBM in nude mice. To enhance vector intra-tumor vector spread, our EGFR retargeted-mir-124 controlled vector was further modified by vector arming with the matrix metalloproteinase gene encoding MMP9. MMP9 degrades collagen type IV, a major component of the extracellular matrix (ECM) and basement membranes of glioblastomas but absent in normal brain tissue. Studies are ongoing to determine whether MMP9 expression enhances vector spread in GBM neurospheres and as a therapeutic agent for enhanced treatment of human GBM in animals.
Another message from America: nutz!

The comedian Bill Cosby had a particularly funny routine about how, as a child, he would listen to scary stories on the radio and become convinced that terrible things would happen to him. One radio programme featured a giant beating chicken heart that threatens to eat New York, about which Cosby had nightmares. If not reformed, Medicare, the federal government sponsored healthcare programme for Americans over 65 and people with disabilities, really will eat the US economy. The atmosphere of brinksmanship and demagoguery that has characterised US politics since Obama was elected has made discussion of Medicare reform politically unfeasible. A progressive tax on wealthy Medicare recipients? ‘No new taxes!’ Restricting choices of unproven medications or procedures? ‘Rationing!’ Arranging a system where patients must see their GP before getting specialty care for their upset stomach? ‘Restricting my freedom!’. So it goes on. Medicare is driving the US economy toward the precipice and was the chief source of the recent endgame negotiations on the debt ceiling. It seems more likely that the US Government would close its military bases in the rest of the world than reform Medicare. Older people vote at a much higher level than any other group. They see Medicare as a promise that they have funded with increasing personal taxes for their working lifetimes. One disclaimer is that I, too, have been a Medicare beneficiary for 2 years. Medicare has three parts — one for hospitals, one for doctors, and one for drugs. The first two have been there from the beginning. The part that pays hospitals is required, which should give some insight into which component of the US health system has the biggest dog in this hunt. Hospitals are addicted to Medicare and negotiated that dependency from its beginning 45 years ago. The second part …
Internet image viewer (iiV).

Background Visualizing 3-dimensional (3-D) datasets is an important part of modern neuroimaging research. Many tools address this problem; however, they often fail to address specific needs and flexibility, such as the ability to work with different data formats, to control how and what data are displayed, to interact with values, and to undo mistakes.
Extreme obesity and postcesarean maternal complications

OBJECTIVE:To estimate the association of obesity and extreme obesity with maternal complications after cesarean delivery.METHODS:This was a secondary cohort analysis of a randomized controlled trial. The parent study was designed to estimate the effect of supplemental oxygen on postcesarean infectio