cssi/SciSciGPT-SciSciNet huggingface dataset:
Steady-state freshwater-seawater mixing zone in stratified coastal aquifers

Summary The mixing zone between freshwater and intruding seawater, which controls regional groundwater flow dynamics and reactive transport processes, is the most important component in coastal aquifers. Laboratory experiments and numerical simulations were conducted to investigate the effects of aquifer stratification on the thickness of a steady-state freshwater–seawater mixing zone. A series of experiments were implemented in a laboratory tank packed with three layers of coastal sands and manipulated by two flow cells for maintaining constant-head boundary conditions. Packed aquifers included a homogenous aquifer, a high hydraulic conductivity (K)–low K–high K stratified aquifer, and a low K–high K–low K stratified aquifer. Both tank-scale and field-scale density-dependent models were developed to simulate the laboratory experiments and to systematically investigate aquifer stratification effects on the thickness of a steady mixing zone with varying layer configurations. Results showed that when an aquifer layer with a low K overlies a layer with a relatively high K, slanting upward flow of diluted saltwater and re-circulated seawater flow are refracted at the interface between the two layers, resulting in streamline separation and a broad mixing zone in the low-K layer. By contrast, the mixing zone in a high-K layer is slightly narrowed when it overlies a layer with a relatively low K because flow refraction squeezes the streamlines within the mixing zone. The mixing-zone profile in head-controlled systems is a function of K contrast, but independent of the magnitude of K. Our results demonstrated the significant impact of aquifer stratification on controlling groundwater flow and solute transport in coastal subsurface environments and would have significant implications for studying physical, chemical and biological processes in coastal subsurface environments, as aquifer stratification is naturally prevalent.
Work in progress — Influences of student experiential background in a problem-based multidisciplinary microfluidics laboratory course

This paper will focus on student experiences in a multidisciplinary microfluidics laboratory course and how these related to students' course expectations, prior experiences and collaboration in laboratory groups as well as other factors. The course under discussion, initially developed at the University of Cincinnati, is a laboratory course that introduces undergraduate and graduate students to microfluidic device development. A unique aspect of the course, which is comprised of modeling, fabrication, and analysis of SU-8 micromixers, is the focus on an extended problem-based learning example that underlies all course activities. This course is an application in microfluidics, a multidisciplinary field that deals with the behavior and precise control of microliter and nanoliter volumes. The course is currently being expanded to four other universities with the assistance of an NSF CCLI Phase II grant (DUE-0814911). The dissemination at several sites allows the opportunity to examine the effects of differing student backgrounds on their experience with and reactions to the course structure and make recommendations to the project team regarding future pedagogical modifications that should be made to improve student learning and interest in pursuing microfluidics.
Comparison of allograft bone and titanium cages for vertebral body replacement in the thoracolumbar spine: a biomechanical study.

Background When an anterior approach to repair a burst fracture is indicated, several devices can be used to restore spinal stability (eg, bone graft, free-standing titanium cage, and expandable titanium cage). Objective We compare the biomechanical stability and prices of each of these systems. Materials and methods Eight fresh human cadaver T11 through L3 vertebral specimens were harvested and cleaned of soft tissues. T11-T12 and L2-L3 were fixed by screws. The fixed ends were then set in automotive body filler (Bondo). The prepared specimens were tested in the Biaxial Instron tester (8874, Norwood, MA) after a sequence of the following: intact, after the creation of an anterior corpectomy at L1, and after insertion of both of the 2 different titanium cages and the fibular graft. A titanium screw-and-plate anterolateral system was used to secure the construct (VANTAGE, Medtronic Sofamor Danek, Memphis, TN). The conditions of displacement testing were as follows: rotation (+/- 3.5 degrees ), flexion and extension, and left and right bending (+/- 3.5 mm). For each mode of testing, the stiffness was calculated. Results The stiffness data, when statistically analyzed by repeated-measures analysis of variance (at P = .05 and power > 0.9), indicated no significant differences among these devices. Conclusion On the basis of this biomechanical study, the stiffness of the fibular graft was similar to that of the other metallic devices in this cadaver model.
Dynamic strain aging in Czochralski-grown silicon single crystals

Abstract Constant extension rate tensile tests were performed on dislocation-free Czochralski-grown ([O] = 24–38 ppma) silicon single crystals oriented for single slip in the temperature range 1173–1573 K. Evidence for dynamic strain aging, resulting from oxygen in solid solution, includes the observation of a plateau in the plot of the lower yield stress vs. strain rate at 1373, 1473, and 1573 K; an increase in the flow stress with temperature above 1373 K; a higher magnitude of the lower yield stress than that observed in float-zone (low-oxygen)-grown silicon for temperatures above 1373 K; and other observations resulting from the analysis of the later stages of deformation. Dynamic precipitation of oxygen caused by the supersaturated condition of oxygen in Czochralski-grown silicon complicates the application of solute hardening models for analyzing the experimental observations.
Molecular mechanisms of loss of beta 2-microglobulin expression in drug-resistant breast cancer sublines and its involvement in drug resistance.

In this study, we investigated the mechanism of the loss or decreased expression of β2-microglobulin (β2m) in several drug-resistant sublines of MCF-7 and in a doxorubicin (DOX)-resistant variant of the T-47D breast cancer cell line. β2m protein and RNA are not expressed in highly metastatic, multidrug-resistant MCF-7/Adr cells with high resistance to DOX. Nuclear run-on transcription and RNA stability assays demonstrate that while β2m in MCF-7/Adr cells is transcribed, its mRNA is rapidly degraded after synthesis in these cells, indicating that it is controlled by post-transcriptional mechanisms. We also show that an MCF-7 subline (MCF-7/Adr-5) expressing a very low level of resistance to DOX has a decreased level of β2m expression. Treatment with actinomycin D revealed that the half-life of β2m mRNA in MCF-7 and MCF-7/Adr-5 cell lines was comparable. Nuclear run-on transcription analysis revealed a decreased rate of β2m transcription in MCF-7/Adr-5 cells compared to that in MCF-7 cells. Moreover, β2m mR...
Endocrine and Vagal Controls of Sympathetically Dependent Neurogenic Inflammationa

: Recently the very significant role of the postganglionic sympathetic neuron (PGSN) terminal in the production of neurogenic inflammation has been appreciated. An important model of this sympathetically dependent inflammation is venular plasma extravasation (PE) and neutrophil attraction produced by local intra-articular injection of the potent inflammatory mediator bradykinin (BK). Sympathetic-dependent PE in the synovium has been proposed as a protective mechanism in arthritis. In a recent series of studies, a novel mechanism has been discovered by which activation of primary afferent nociceptors exerts a potent feedback inhibition of PGSN-dependent PE. Activation of nociceptive afferents was shown to be involved in this feedback system. Such a negative feedback control of the acute inflammatory response would have survival value; the inflammatory response, as initiated by a high degree of positive feedback, and the inflammatory process itself when persisting can result in significant tissue injury. If indeed HPA axis activity plays a significant physiological role in the modulation of neurogenic inflammation, then physiological processes that modulate the HPA axis would be expected to influence neurogenic inflammation. A dramatic effect of this kind has been demonstrated, in the rat, for vagal afferent activity. In the presence of subdiaphragmatic (or celiac branch) vagotomy, the potency of nociceptive afferent activity to inhibit sympathetically dependent, BK-induced PE was increased by four orders of magnitude compared to vagus-intact animal. Hypoactivity or hyperactivity of these vagally mediated mechanisms could contribute to diseases characterized by either an inadequate or an exaggerated inflammatory response.
Degeneration of the intersegmental muscles: alterations in hemolymph during muscle degeneration.

Abstract Alterations in hemolymph constituents during the degeneration of the intersegmental muscles of Manduca sexta and Antheraea polyphemus have been followed by several techniques. An antigen to muscle protein appears in the blood within 5–10 hr after the adult has emerged. When tritiated leucine is injected into developing pupae, labeled protein and amino acids are released into the blood during the period over which the muscles degenerate. Blood levels of lactic dehydrogenase, glutamine-oxaloacetate transaminase, arginine phosphokinase, and aldolase increase approximately 8–9 hr after the insects emerge. The latter two enzymes increase sixfold over preemergence levels, and are highest during the period over which muscle integrity is compromised. The levels of circulating muscle proteins decrease after 30–50 hr. These several data suggest that a fraction of the muscle protein is not digested within the muscle fiber, but is solubilized or otherwise released into the hemolymph, to be digested elsewhere.
Pleurothotonus and the Pisa syndrome.

To the Editor: The report of Yassa et al (1991) is one of only two systematic studies of the Pisa syndrome that have appeared very recently, the other being that of Suzuki et al (1990). Prior to these studies, there were only a few case reports of this phenomenon. Ekbom et al (1972) coined the term "Pisa syndrome" to describe the presentation of three patients who developed a postural abnormality consisting of leaning to one side (lateral torso flexion), usually accompanied by slight posterior rotation of the torso, while being treated with neuroleptics. Following Pilette (1987), Yassa et al (1991) employed the descriptive terhn "pleurothotonus" as synonymous with the Pisa synd~orae irl the title of their paper. Pilette (1987) had pointed out that the term "pleurothotonus" predated that of "Pisa syndrome," and stated that this particular postural abnormality is at least as common as opisthotonus even though it is mentioned less frequently in recent textbooks. Strictly speaking, Pisa syndrome designates an entity more specific than pleurothotonus. Pleurothotonus delineates an anatomic deviation that could be observed prior to the advent of neuroleptic compounds. As with opisthotonus, it was, in the past, often considered to be a typical presentation of conversion hysteria. Pleurothotonus, also called "tetanus laterali~," designates a physical finding that could be related to any ,,~ a number of potential etiologies of dystonic phenomena (see DeSilva et al 1973). It is, therefore, not quite synonymous with Pisa syndrome, which in the original report implicated neuroleptic treatment in the etiology of the clinical findings. When Ekbom et al (1972) stated that they had "christened this peculiar body pos ture . . , after the well-known Italian structure," they were designating a "new dystonic syndrome associated with butyrophenone therapy." Therefore, the appropriate synonym for the Pisa syndrome would be "neuroleptic-induced pleurothotonus," or simply "drug-induced pleurothotonus."
The relationship between coding sequences and function in some heme binding proteins.

It is known that globin genes contain three exons with the middle exon coding for a four-helical supersecondary structure responsible for heme binding. Since this portion of the globin peptide chain can be structurally superimposed onto the cytochromec and cytochromeb5 chains (Argos and Rossmann 1979), it can be inferred that the cytochromec gene will contain only one coding sequence while the cytochromeb5 gene will be composed of three exons as found in the globin gene.
The design of a crevasse detector for polar exploration

Abstract A recently discovered electrical method for locating dangerous covered crevasses has been successfully reduced to practice. Some tentative design principles for a practical vehicular crevasse detector have been formulated. These have been embodied in fifteen experimental units now available to U. S. government agencies in the polar regions. Each such unit includes a flexible array of 20 ft-long. timbers controlling a group of 43-in. dish-shaped electrode sleds which is pushed ahead of a “weasel” vehicle, additional electrodes dragged behind, and a suitable electrical system including a signal-indicating ink recorder and an adjustable alarm system responding to abnormal signal levels. One unit of this equipment has given valuable assistance in early Antarctic over-ice operations for the IGY. However, further improvements are desirable and many uncertainties remain unresolved by field experience at this time.
Studies on the stimulation of phenylalanine hydroxylase activity by short-chain alcohols.

Abstract The activity of rat liver phenylalanine hydroxylase (EC 1.14.3.1) is enhanced in vitro by several short-chain alcohols. The stimulation is neither species- nor substrate-specific, and the degree of stimulation depends both upon alcohol concentration and chain length, substrate concentration, as well as the pH and temperature of the incubation medium. The stimulation at pH 7.4 by 7.5% ethanol (v/v) at 20, 30 and 37°C is accompanied by a marked decrease in the apparent Michaelis constant for phenylalanine and, at 20 and 30°C, by an increase in the maximum velocity. Ethanol (7.5%) also increases the apparent Michaelis constants for a synthetic pterin cofactor and for O2. The relatively greater effect of ethanol at 20 °C than at higher temperatures suggests that it might act by lowering the activation energy for the hydroxylation reaction.
Analysis and performance of the control systems of the NASA 70-meter antennas

Abstract The control systems of the NASA 70-m antennas include the antenna control system, the Master Equatorial (ME) control system, and their combinations (called modes). The Master Equatorial is a small telescope mounted on the top of a tower located inside the antenna structure. In the Antenna Encoder mode antenna encoders are used to close the feedback loop. In the Autocollimator mode the Master Equatorial is a master that follows a target, and the antenna is a slave that follows the Master Equatorial. In the Master Equatorial Encoder mode the “master-slave” relationship is reversed. In the paper the analysis begins with the description of the open-loop models of the antenna and of the Master Equatorial. We obtained the models by using field test data and system identification techniques. Next, we analyzed and evaluated the performance of the three modes of the antenna control system. The analysis showed that the Autocollimator and Master Equatorial Encoder tracking modes are feasible for high-rate tracking, and that the latter mode has the smallest tracking error. Finally, we analyzed the switching between antenna modes, necessary while tracking near the keyhold. We showed that switching causes jerks of magnitudes within the acceptable threshold. The contribution of this paper includes the development of the antenna model using field data and system identification procedures, the development of the LQG control algorithm for the 70-meter antenna, the development of two control cooperating systems (antenna and ME), identifying the more appropriate, and analyzing of switching between the two control systems.
The Valuation of Convertible Securities

I. Introduction, 48. â€” II. A preliminary model for the valuation of convertible bonds, 49. â€” III. Statistical implementation of the model, 51. â€” IV. Altering the assumptions, 54. â€” V. Summary comment, 59.
Cohort study of medication adherence in older adults (CoSMO): extended effects of Hurricane Katrina on medication adherence among older adults

Background Previous research indicates that many patients with hypertension ran out of medications and had difficulties getting refills immediately after Hurricane Katrina. The extended effect of Hurricane Katrina on antihypertensive medication adherence is not well characterized.
Outcome of Right Ventricle to Pulmonary Artery Conduit for Biventricular Repair

Background The objective of this study was to assess the outcomes of the right ventricle to pulmonary artery conduit for biventricular repair. Methods This is a retrospective review of all right ventricle to pulmonary artery conduit operations for biventricular repair of congenital heart disease between 1982 and 2013 at a single institution. Results were compared among the conduit size and materials. Results A total of 476 physiologic right ventricle to pulmonary artery conduit operations were identified, with 195 pulmonary homografts, 105 handmade valved expanded polytetrafluoroethylene conduits, 103 Medtronic Hancock (Minneapolis, MN) bioprosthetic valved conduits, 38 non-valved expanded polytetrafluoroethylene tubes, and 35 others. The actuarial survival was 92.4% and the freedom from conduit reoperation was 33.0% at 20 years. The freedom from conduit reoperation was significantly different among conduit materials (76.8%, 92.1%, 81.9%, 80.6%, and 63.8% for pulmonary homograft, valved expanded polytetrafluoroethylene conduit, Hancock conduit, non-valved expanded polytetrafluoroethylene tube, and others at 5 years, p = 0.0001). The Cox proportional hazards model showed that age ( p p = 0.04), preoperative diagnosis ( p p p p p = 0.01 and p = 0.02, respectively) were significant factors for the freedom from conduit reoperation both when treating conduit size as a categoric predictor and as a quantitative predictor. Conclusions The handmade valved expanded polytetrafluoroethylene conduit showed excellent early outcome as a right ventricle to pulmonary artery conduit for biventricular repair. A longer follow-up and a randomized study will be necessary to explore the advantages of the valved expanded polytetrafluoroethylene conduit.
Reconstructive processing of memory content for high versus low test scores and grades

Self-reported SAT and ACT scores and grades in college-level mathematics and related courses were verified for 494 individuals. Correct responses decline for 2 years and then stabilize. The percentage of correct responses is approximately twice as high for individuals whose grades are in the upper tercile than for those whose grades are in the lowest tercile. Given that an incorrect report is made, the proportion of those overstating grades or test scores is approximately 0.50 for those in the upper tercile of the distribution, and 0.90 and 0.75 for those in the lowest tercile of the grade and test score distribution. The inflated reports of grades and test scores by individuals with low scores are interpreted as reconstructions of memory content based on failure experiences and the affective context of these experiences.
A translocated mitochondrial cytochrome b pseudogene in voles (Rodentia: Microtus)

A full-length cytochrome b pseudogene was found in rodents; it has apparently been translocated from a mitochondrion to the nuclear genome in the subfamily Arvicolinae. The pseudogene (ψcytb) differed from its mitochondrial counterpart at 201 of 1143 sites (17.6%) and by four indels. Cumulative evidence suggests that the pseudogene has been translocated to the nucleus. Phylogenetic reconstruction indicates that the pseudogene arose before the diversification of M. arvalis/M. rossiaemeridionalis from M. oeconomus, but after the divergence of the peromyscine/sigmodontine/arvicoline clades some ∼10 MYA. Published rates of divergence between mitochondrial genes and their nuclear pseudogenes suggest that the translocation of this mitochondrial gene to the nuclear genome occurred some 6 MYA, in agreement with the phylogenetic evidence.
Linking Academic Entitlement and Student Incivility Using Latent Means Modeling

Academic entitlement has been theoretically linked with uncivil student behavior; however, this relationship has not been tested. To address this gap in the literature, the authors used latent means modeling to estimate the relationship between the Academic Entitlement Questionnaire and uncivil student behavior. The authors gathered scores on the questionnaire from 2 samples of students: civil/compliant and uncivil/noncompliant. Measurement invariance was established for the Academic Entitlement Questionnaire, providing additional validity evidence for the scale and allowing for the estimation of the latent mean difference in academic entitlement. As predicted, noncompliant students were significantly higher in academic entitlement than were compliant students. These results empirically link academic entitlement and student incivility, further supporting that academic entitlement is an important construct in academia and should receive increased attention from educators.
Alkalinity, Discharge, Average Velocity, and Invertebrate Drift Concentration in Subarctic Alaskan Streams

ABSTRACT This study measured the associations of alkalinity, current and invertebrate drift among 13 streams in subarctic Alaska. A significant positive correlation was found between alkalinity and drift concentration expressed as numbers per unit volume. Significant inverse relations were found between stream discharge and drift concentration expressed as either numbers or weight. This “dilution” was to be expected since stream wetted perimeter, the source of invertebrates to drift, increases as approximately the square root of the discharge. Multiple regression analysis also showed a positive relation between stream average velocity and drift concentrations. Invertebrate drift was seen, therefore, to be somewhat analogous to sediment transport in streams.
Angelus Silesius: A Seventeenth-Century Mystic

During the last quarter-century more investigation than ever before has been going on into the unconscious activities of the human mind, or, as the investigators have preferred to call it, the sub-conscious mind. This has led in psychology to the study of apparitions and the various forms of telepathy, and in religion to a revival of Quietism. Religious bodies as far from Quakerism as the Episcopal Church are holding retreats for meditation, silent prayer, “the practice of the presence of God.” The exclusion of worldly thought is pointed to as the means for the opening of the soul to the incoming of the Divine; and some are following the Mystic Way through its steps of Purgation, Illumination, and Ecstasy to its goal of absorption into God in the Unitive Life.
Extension of a result by Lindquist to Lebesgue spaces with variable exponents

Abstract We investigate the family of variable-exponent type eigenvalue problems − Δ p j ( ⋅ ) u = λ j | u | p ( ⋅ ) − 2 u and prove the convergence of the eigenfunctions under suitable conditions on the sequence ( p j ) .
SU(2) flux distributions at finite temperatures

Abstract We studied the flux distributions of a q q pair at finite temperatures using SU(2) lattice gauge theory. Our results display the different behaviors of flux distributions in the confined and unconfined phases. Finite-volume effects on flux distributions and the string tension are discussed.
Allergenic proteins are fragmented in low concentrations of sodium hypochlorite.

Background To facilitate allergen removal from indoor environments, it would be helpful to have household cleaning products that modified allergenic activity. Because NaOCl dissolves proteins in high concentrations and is both capable of killing bacteria and viruses and inactivating viral antigens at somewhat lower concentrations, we explored its effects on Mus m 1 and other indoor allergens. Objective To examine the ability of NaOCl to reduce the allergenicity of Mus m 1 and other indoor allergens. Methods Using purified mouse urinary allergen, we examined the effect on protein measured by Coomassie protein assay and on Mus m 1 measured by ELISA. We also examined the effects using SDS/PAGE and Western blots probed with sheep anti-Mus m 1 and with allergic human serum. Results When NaOCl and Mus m 1 were combined in a molar ratio of 100 : 1, IgE binding to Mus m 1 on Western blot was significantly reduced. At higher NaOCl concentrations the protein appeared to fragment and eventually became undetectable. Fragmentation appeared to be random in that peptides of a wide range of apparent molecular weight were produced. The reaction was complete within 1–2 min at OCl : pr ratios of greater than 200 : 1 and was optimal at pH 7.4. Immunological activity of other allergens (Fel d 1, Bla g 1, Der p 1) was decreased in vitro and dried allergen extracts were removed from surfaces. Adding an extraneous protein, BSA, to NaOCl:Mus m 1 solutions decreased the effect of NaOCl on the allergen. Conclusions We concluded that NaOCl at concentrations commonly used in household products is capable of dramatically affecting allergenic protein.
Optimal Electrode Designs for Electrosurgery, Defibrillation, and External Cardiac Pacing

We have developed a simple and easily modifiable two-dimensional finite element computer model of the human torso, which allows us to predict current delivery from arbitrarily placed and designed electrodes. Using this model, the performance of many variations from the commonly used gelled-pad electrode, applied to a torso of uniform and isotropic resistivity, has been examined by independently varying the thickness, width, and resistivity of the gel layer, as well as the width of the conducting plate. We compared the electrode performances on the basis of their ability to maintain a uniform current density at the electrode-body interface, which is thought to be of critical concern in avoiding burn, pain, and other complications in electrosurgery, external cardiac pacing, and defibrillation. In addition to studying the effects of geometric and electrical design variations, we have isolated two electrode designs of particular importance: 1) a simple plate electrode with a uniformly high resistivity gel layer and intermediate conducting plate width, which could be used for low-energy applications such as external cardiac pacing, and 2) an annular electrode in which the resistivity of the gel varies as a function of distance to the electrode center, which could be used for high-energy applications such as electrosurgery and defibrillation, as well as for external cardiac pacing.
Dissociation of the plasticity of 5-HT1A sites and 5-HT transporter sites.

To study the early effects of neonatal 5,7-dihydroxytryptamine lesions on 5-hydroxytryptamine1A (5-HT1A) receptors, we measured regional [3H]8-OH-DPAT-labeled 5-HT1A sites in binding assays and compared them to our previous studies of [3H]paroxetine-labeled 5-HT transporter sites during the first month in the same rats. While there were significant time- and dose-dependent effects of 5,7-DHT on 5-HT transporter sites, there were no significant changes in 5-HT1A sites in cortex, hippocampus, diencephalon, brainstem, cerebellum, or spinal cord. 5,7-DHT lesions also did not alter the Ki of Gpp(NH)p at brainstem 5-HT1A sites or the Ki of 5-HT in cortex or brainstem in the presence or absence of GTPγS or Gpp(NH)p. There were significant regional differences between the density of 5-HT1A sites and 5-HT transporter sites. The ontogeny of brainstem 5-HT1A sites was a pattern of increases until three weeks postnatal, and 5,7-DHT lesions did not alter the ontogeny of 5-HT1A sites. These data suggest differential plasticity of 5-HT1A and 5-HT transporter binding sites during the first month after neonatal 5,7-DHT lesions.
Attitudes of Rural Communities Toward Wetlands and Forest Fragments Around Kibale National Park, Uganda

Rapid population growth, high population density, and intensive agriculture characterize the landscape surrounding Kibale National Park in western Uganda. Forest fragments and wetlands scattered throughout the agricultural landscape provide important natural resources for local people. These forest fragments, however, also provide habitat for animals that raid crops and threaten local agricultural practices, leading to human–wildlife conflict in the buffer zone of the park. Using a geographically stratified, random sampling technique to select study sites, 130 households outside Kibale were interviewed to understand human–agriculture–wildlife conflicts and how these problems vary spatially and demographically. Primates were the most common taxa associated with crop raiding, with vervet and redtail monkeys ranked as the worst crop raiders overall. Baboons and elephants were also problematic in agricultural areas proximate to the park boundary. Despite the problems reported, most respondents prefer to live ...
Low Thermal Inertia Molding (LTIM)

Abstract Injection molding is one of the most commonly used methods of processing polymers. The process allows rapid, automated production of a wide variety of complicated, three-dimensional parts in large production volumes. The process is capable of producing compound curvatures, snaps, hinges, bosses, threaded holes, gear teeth, and many other features. With proper design, these complex parts can be produced in a single molding operation.
The effect of urologist experience on choosing active surveillance for prostate cancer

To evaluate the impact of the urologist’s experience in selecting active surveillance (AS) versus immediate treatment (IT) for low-risk prostate cancer. Men with low-risk prostate cancer were enrolled from March 2011 to August 2013 at 13 medical centers in Kaiser Permanente Southern California. The AS cohort was defined as men who had cT1-T2a stage prostate cancer, prostate-specific antigen <10 ng/ml, a biopsy revealing Gleason grade ≤6, fewer than three biopsy cores positive, ≤50 % cancer in any core, and not undergone immediate therapy (surgery, radiation, other) within 6 months following diagnosis. The urologist’s experience (age, number of years in practice, number of robotic surgeries performed, and fellowship experience in oncology and/or robotics) was then compared between AS and IT cohorts. A total of 4754 men were diagnosed with prostate cancer, and 713 men satisfied with inclusion criteria; 433 (60.7 %) and 280 (39.3 %) chose AS and IT, respectively. A total of 87 urologists were included. Univariate and multivariate adjusted analyses revealed no differences in urologist’s age or years in practice. Patients who saw urologists who had performed ≥50 robotic surgeries were less likely to choose AS (OR 0.40, 95 % CI 0.25–0.66). Patients who saw urologists with a fellowship in oncology and/or robotics were more than twice as likely to choose AS (OR 2.27, 95 % CI 1.38–3.75). These data suggest that the decision to pursue AS may be influenced by the urologist’s experience.
Formative Time Lags of Spark Breakdown in Air in Uniform Fields at Low Overvoltages

An attempt has been made to establish the region of validity of the streamer and Townsend mechanisms of spark breakdown in air by measurements of the formative time lag of the breakdown process.Formative time lags were measured in a uniform field for overvoltages of a few percent down to as close to threshold as possible. Such measurements have been carried out as a function of pressure (atmospheric to a few cm of Hg) and plate separation (0.3 to 1.4 cm). For pressures greater than 200 mm Hg, the formative time lags very close to threshold are of the order of 100 \ensuremath{\mu}sec and longer. These times are orders of magnitude lnger than those previously reported. For all pressures studied, the time lags decrease as the percent overvoltage (percent o.v.) increases, until at about two percent above threshold, the formative times are of the order of 1 \ensuremath{\mu}sec. The time lag vs percent o.v. curve is independent of pressure from atmospheric down to 200 mm Hg. At a given percent o.v., the time lags increase linearly with plate separation. Changing the approach voltage from two to four kv below breakdown does not affect the results appreciably. The number of initiating electrons at the cathode has been varied by a factor of about seven, and this again does not materially alter the results.The long time lags and their dependence on pressure and percent o.v. cannot be explained by secondary emission of electrons from the cathode by positive ion bombardment. The proper explanation is the enhancement of field intensified ionization due to field distortion acting in conjunction with a photoelectric secondary process. The experiment demands an extension of the streamer concept of breakdown, and makes very questionable the role of positive ion bombardment of the cathode in spark breakdown for the pressures and plate separations studied. No transition region for change of streamer to Townsend breakdown was found.
Development of Thalamocortical Response Transformations in the Rat Whisker-Barrel System

Extracellular single-unit recordings were used to characterize responses of thalamic barreloid and cortical barrel neurons to controlled whisker deflections in 2, 3-, and 4-wk-old and adult rats in...
Constructing a Community Food Economy

This article addresses paradigm shifts in the U.S. food system and the problems that commodity food poses for local food movements. Balancing the availability of low-cost food for everyone and living wages for local farmers and farm workers presents a major challenge to successfully shifting from a productionist to an ecologically integrated agrifood paradigm. Local food movements juxtapose a knowledge-rich food environment to the one imposed by the productionist paradigm of industrial agriculture in which the origins of food products and the methods of their production are hidden from the consumer. “Commodity foods,” then, represent the anonymity and the hypercommodification that characterizes the global food system. This article examines the struggle to vertically integrate the local food system in Oregon's Willamette Valley. 1
Orientational Fluctuations in a Two-Dimensional Smectic- C Liquid Crystal with Variable Density

We studied orientational fluctuations in a smectic-C Langmuir monolayer. Our measurements of orientational correlations are in excellent agreement with theoretical predictions. In addition, we present the first measurements of orientational elasticity and viscosity in a two-dimensional system whose density can be varied. The orientational viscosity strongly depends on temperature and density, changing by more than an order of magnitude with a 2.5% increase in temperature or a 20% change in density. The orientational elasticity is only weakly dependent on temperature and density.
Reaction kinetics measurements and analysis of reaction pathways for conversions of acetic acid, ethanol, and ethyl acetate over silica-supported Pt

Abstract Reaction pathways for the catalytic conversions of acetic acid, ethanol and ethyl acetate over Pt were studied by collecting reaction kinetics data over a Pt/SiO2 catalyst at temperatures from ca. 500 to 600 K, by conducting density functional theory (DFT) calculations for various adsorbed species and transition states on Pt(1 1 1) slabs, and by carrying out reaction kinetic analyses using a kinetic model based on the results from DFT calculations. An equi-molar mixture of CO and CH4 is made from acetic acid. Equi-molar amounts of CO and CH4 are also made from ethanol. Ethane is produced from ethanol and ethyl acetate. Ethanol and acetaldehyde are produced from ethyl acetate. Under all conditions of this study, acetaldehyde and ethanol are present in the reactor effluent as a quasi-equilibrated mixture. General agreement is achieved between the experimental reaction kinetics results and the predictions of the kinetics model for the rates of formation of various products measured. The values of the parameters estimated from reaction kinetic analyses are in good agreement with estimates provided by DFT calculations (within 20 kJ/mol). It appears that the simplified reaction scheme of the present study qualitatively captures the essential surface chemistry involved in the catalytic conversions of acetic acid, ethanol and ethyl acetate over Pt. This simplified reaction scheme can be used to guide further research into the factors that control catalyst selectivity. Sensitivity analyses were conducted to assess which steps in the reaction scheme exhibit the highest degree of rate control for the catalytic conversions of acetic acid, ethanol, and ethyl acetate over Pt. It appears that the reaction kinetics are controlled by six reactions. Further studies of these transition states may provide insight into how the selectivity for hydrogenation of oxygenated hydrocarbons is affected, for example, by forming metal alloy particles, by changing the geometry of the active sites, and by changing the nature of the active metal component.
Re-Conceptualization of Literature in Marketing on the Measurement of Differences within Immigrant/Ethnic Populations

Abstract First, the importance of understanding what the key differences are between individuals in any ethnic population is highlighted. Next, the concept of assimilation is introduced as a construct by which these differences may be accounted for. Following this, the literature on the measurement of differences within ethnic markets is surveyed and classified in light of the assimilation construct and a set of conclusions based on this survey are drawn up. Finally, based on these conclusions, a set of recommendations is developed to guide researchers in the future who might wish to rigorously measure the major differences within any ethnic population group.
A reinforcement learning approach in rotated image recognition and its convergence analysis

One of the major problems in automatic target recognition (ATR) involves the recognition of images in different orientations. In a classical training-testing setup for an ATR for rotated targets using neural networks, the recognition is inherently static, and the performance is largely dependent on the range of orientation angles in the training process. To alleviate this problem, we propose a reinforcement learning (RL) approach for the ATR of rotated images. The RL is implemented in an adaptive critic design (ACD) framework wherein the ACD is mainly composed of the neuro-dynamic programming of an action network and a critic network. The proposed RL provides an adaptive learning and object recognition ability without a priori training. Numerical simulations demonstrate that the proposed ACD-based ATR system can effectively recognize rotated target with the whole range of 180° rotation. Analytic characterization of the learning algorithm provides a sufficient condition for its asymptotic convergence. Finally, we obtain an upper bound for the estimation error of the cost-to-go function under the asymptotic convergence condition.
Continental drift and the use of albumin as an evolutionary clock

ACCORDING to the concept of proteins as evolutionary clocks1, change in amino acid sequence during evolution is primarily a time-dependent process. This process accounts for the correlation generally found between the amount of time that has elapsed since two species last shared a common ancestor and the degree to which the sequences of their proteins differ today. A body of data consistent with such a correlation is now available for many proteins and nucleic acids2–9. Although there is increasingly widespread agreement that such a correlation exists10–12 it is difficult to ascertain how strong the correlation is because of uncertainties in the interpretation of the fossil record, particularly with regard to times of divergence of lineages.
A general model for the dynamics of cell volume, global stability, and optimal control

Cell volume and concentration regulation in the presence of changing extracellular environments has been studied for centuries, and recently a general nondimensional model was introduced that encompassed solute and solvent transmembrane flux for a wide variety of solutes and flux mechanisms. Moreover, in many biological applications it is of considerable interest to understand optimal controls for both volume and solute concentrations. Here we examine a natural extension of this general model to an arbitrary number of solutes or solute pathways, show that this system is globally asymptotically stable and controllable, define necessary conditions for time-optimal controls in the arbitrary-solute case, and using a theorem of Boltyanski prove sufficient conditions for these controls in the commonly encountered two-solute case.
Oxidations of N-(3-Indoleethyl) Cyclic Aliphatic Amines by Horseradish Peroxidase : The Indole Ring Binds to the Enzyme and Mediates Electron-Transfer Amine Oxidation

Although oxidations of aromatic amines by horseradish peroxidase (HRP) are well-known, typical aliphatic amines are not substrates of HRP. In this study, the reactions of N-benzyl and N-methyl cyclic amines with HRP were found to be slow, but reactions of N-(3-indoleethyl) cyclic amines were 2-3 orders of magnitude faster. Analyses of pH-rate profiles revealed a dominant contribution to reaction by the amine-free base forms, the only species found to bind to the enzyme. A metabolic study on a family of congeneric N-(3-indoleethyl) cyclic amines indicated competition between amine and indole oxidation pathways. Amine oxidation dominated for the seven- and eight-membered azacycles, where ring size supports the change in hybridization from sp3 to sp2 that occurs upon one-electron amine nitrogen oxidation, whereas only indole oxidation was observed for the six-membered ring congener. Optical difference spectroscopic binding data and computational docking simulations suggest that all the arylalkylamine substrates bind to the enzyme through their aromatic termini with similar binding modes and binding affinities. Kinetic saturation was observed for a particularly soluble substrate, consistent with an obligatory role of an enzyme-substrate complexation preceding electron transfer. The significant rate enhancements seen for the indoleethylamine substrates suggest the ability of the bound indole ring to mediate what amounts to medium long-range electron-transfer oxidation of the tertiary amine center by the HRP oxidants. This is the first systematic investigation to document aliphatic amine oxidation by HRP at rates consistent with normal metabolic turnover, and the demonstration that this is facilitated by an auxiliary electron-rich aromatic ring.
Grazing and excretion by zooplankton in the Peru upwelling system during April 1977

Abstract Rates of ingestion and excretion by adult females of the copepods Calanus chilensis, Eucalanus inermis , and Centropages brachiatus were measured in natural seawater during a cruise in the Peru upwelling system during April 1977. Simultaneously, zooplankton samples were collected for later determination of the abundance and distribution of these and other species. For these three organisms, feeding, and excretion rates of individuals are combined with information on the animal concentrations to estimate the grazing stress on the phytoplankton at each station, and to estimate the excretory nitrogen produced at each station. Comparison of grazing stresses with measured rates of primary production indicates that these large copepods were harvesting less than 5% of the daily phytoplankton production. Comparison of the nitrogen excretion rates with the amounts of excreted nitrogen in the water column indicates that less than 3% of the ambient excretory nitrogen was produced daily by these copepods. The importance of the abundant small zooplankton in the system is suggested.
P waves in the electrocardiogram recording of tachycardia: 'you can run, but you cannot hide'.

This editorial refers to ‘A new method of filtering T waves to detect hidden P waves in ECG signals’ by D. Goldwasser et al ., on page 1028. The history of the evolution of recording of cardiac electrical activities by electrocardiogram (ECG) is quite fascinating.1 The initial ECG recording systems used by Waller, Einthoven, and Lewis consisted of mercury capillary electrometers and string galvanometers that were cumbersome to use and provided limited information.1–3 In Waller's demonstration of the human ECG, only ventricular activities were recorded and the P waves were not discernible.1 Interestingly, even today there are situations where in the ECG recordings obtained with modern and sophisticated ECG machines the P waves may not be easily discernible. Interpretation of ECG recordings remains fundamental to the clinical investigation of cardiac arrhythmias. To confirm the diagnosis of ventricular tachycardia from the ECG tracing of a wide complex tachycardia would require accurate detection of the P waves to determine atrioventricular (AV) dissociation. Likewise, detection of the P waves, their morphological characteristics, axis, and timing relationships with the R waves would be important to confirm and further differentiate supraventricular tachycardias (SVTs) into AV nodal reentrant tachycardia (AVNRT), accessory bypass tract-mediated AV reentrant tachycardia (AVRT), atrial tachycardia, junctional ectopic tachycardia, or sinus tachycardia. However, simple as it sounds, the task of finding P waves let alone their characterization may be extremely difficult, if not impossible. In an approach to make a correct diagnosis of SVT recorded by 12-lead ECG, general criteria such as RP intervals, QRS alternans, pseudo-r′, pseudo-S-wave, etc. although frequently used, lack robustness in their sensitivity and specificity. Because the P waves are generated by the atrial chambers that have lower muscle mass, they are of lower amplitude when compared with the QRS complexes. As such, during SVT …
Is there an optimal laser treatment for port wine stains

Optimization of laser treatment of port wine stains (PWS) is discussed from the standpoint of heat production. Laser wavelength, irradiation time, heat conduction, and external epidermal cooling are the variables considered in conjunction with absorbing and scattering behavior of a PWS-model consisting of epidermis, dermis, and ectatic blood vessel. Ideal treatment is defined as minimal heating of the epidermis and upper dermis, but with irreversible damage to the capillary wall. The analysis shows that irradiation times of 1-10 ms in conjunction with external epidermal cooling may give optimal results. The wavelength of choice is 577 nm, followed by 540, 415, 560, and 500 nm (argon laser). The ruby and Nd-YAG lasers are predicted to damage the epidermis and dermis at all times when the capillary is coagulated. Concurrent cooling to prevent epidermal-dermal damage is also recommended here. The CO2 laser is predicted to be the worst laser and, according to our analysis, should not be used to treat PWS. Both upper dermal and capillary destruction can only result from heat conduction from the damaged epidermis and external cooling cannot be applied here.