cssi/SciSciGPT-SciSciNet huggingface dataset:
Free Waves on Barotropic Vortices. Part I: Eigenmode Structure

To understand the nature of coupling between a hurricane vortex and asymmetries in its near-core region, it is first necessary to have an understanding of the spectrum of free waves on barotropic vortices. As foundation for upcoming work examining the nonaxisymmetric initial-value problem in inviscid and swirling boundary layer vortex flows, the complete spectrum of free waves on barotropic vortices is examined here. For a variety of circular vortices in gradient balance the linearized momentum and continuity equations are solved as a matrix eigenvalue problem for perturbation height and wind fields. Vortex eigensolutions are found to fall into two continuum classes. Eigenmodes with frequencies greater than the advective frequency for azimuthal wavenumber n are modified gravity‐inertia waves possessing nonzero potential vorticity in the nearcore region. Eigenmodes whose frequencies scale with the advective frequency comprise both gravity‐inertia waves and Rossby‐shear waves. Linearly superposing the Rossby‐shear waves approximates the sheared disturbance solutions. For wavenumbers greater than a minimum number, Rossby‐shear waves exhibit gravity wave characteristics in the near-vortex region. Although such eigenstructure changes are not anticipated by traditional scaling analyses using solely external flow parameters, a criterion extending Rossby’s characterization of ‘‘balanced’’ and ‘‘unbalanced’’ flow to that of azimuthal waves on a circular vortex is developed that correctly predicts the observed behavior from incipient vortices to hurricane-like vortices. The criterion is consistent with asymmetric balance theory. Possible applications of these results to the wave-mean-flow dynamics of geophysical vortex flows are briefly discussed.
Mathematical model for frequency modulation in the respiratory network

Neuromodulators, such as amines and neuropeptides, alter the activity of neurons and neuronal networks. In this work, we investigate how neuromodulators which activate G-proteins and second messenger systems can modulate the frequency of bursting neurons in a critical portion of the respiratory neural network, the pre-Botzinger complex (pBC). Inspiratory neurons in the pBC produce a regular bursting rhythm in phase with the activity of inspiratory muscles in the diaphragm. These neurons are a vital part of the ponto-medullary neuronal network, which generates a stable respiratory rhythm [1]. The frequency of pBC depends on the concentration of Serotonin (5-HT) and Substance P (SP), neurotransmitters released by the nearby Raphe nucleus. Both neurotransmitters, 5-HT and SP, affect pBC neurons by activating receptors coupled with the Gq protein pathway, thereby inducing Ca2+ release from the Endoplasmic Reticulum (ER). We have previously developed a mathematical model of the pBC neuron, which incorporates explicit activation of Gq-protein coupled receptors, and have shown that activation of these receptors can result in Ca2+ oscillations in the dendritic compartment [2]. The model exhibits two independent bursting mechanisms – bursting in the soma depends on persistent sodium current, whereas bursting in the dendrite follows Ca2+ oscillations. It has been recently found that the connection between the pBC and the Raphe nucleus is bi-directional: not only does the Raphe nucleus release 5-HT and SP to modulate the frequency of pBC neurons, but also the rhythmic activity in the pBC increases the firing of Raphe neurons [3]. In this work, we extend our model to a network of pBC neurons while incorporating this newly discovered interaction between Raphe and pBC nuclei. Using a simulated 50-cell network of excitatory connected pBC neurons with a heterogeneous distribution of persistent sodium conductance and ER Ca2+, we show that a tonic release of neurotransmitters acting on the Gq protein pathway increases the number of intrinsic bursters in such a network. However, when we simulated the application of different concentrations of SP or 5-HT, there was no dose-dependent frequency modulation. We then added a positive feedback between the Raphe excitability and pBC activity, representing the release of neurotransmitters from Raphe, and found that this feedback induces frequency modulation the pBC neurons (Figure ​(Figure1).1). Thus, our model shows that the frequency of the respiratory rhythm can be modulated via phasic release of 5-HT and SP from the Raphe nucleus. Figure 1 Inspiratory frequency modulation of pBC by excitatory neurotransmitters, which act on Gq-coupled receptor. [NT] represents neurotransmitter concentration. (A-C) Example of raster plots for three different neurotransmitter concentrations. (A) Rhythmic ...
The long-term cost effectiveness of treatments for benign prostatic hyperplasia.

Introduction Excellent treatment outcomes with long-term durability and few adverse effects are expectations of treatments for chronic conditions. The long-term cost effectiveness of newer treatments for benign prostatic hyperplasia (BPH), including high-energy transurethral microwave thermotherapy (TUMT) and combination pharmaceutical therapy, has not been sufficiently studied against existing alternatives. The objective of this study was to estimate the incremental cost effectiveness of BPH treatment alternatives.
3:53 Anterior discectomy with fusion with allograft and plating

Abstract Purpose of study: Although anterior cervical discectomy and fusion is a well-established technique for arthrodesis of the cervical spine, there are limited data on the use of allograft with plate in a large series with minimum 2-year follow-up. There are even fewer such studies that incorporate three- and four-level fusions. We report our experience with 134 patients (272 levels). Methods used: A total of 134 patients underwent anterior cervical discectomy and fusion (ACDF) with plate and allograft (56, one level; 31, two levels; 30, three levels; 16, four levels; 272 total levels: 37 C3–4, 74 C4–5, 94 C5–6, 65 C6–7, 1 C7–T1) by means of a modified Smith-Robinson technique. All surgeries were performed by the primary senior author (RFD). Key elements of the surgical technique emphasize precise fit and fill of the interspace in conjunction with construct compression. Radiographic fusion was determined with plain X-rays at predetermined intervals. Fusion was defined as no lucent line and no hardware failure. Hardware failure was defined as any screw loosening or shifting of the plate. Average follow-up is 37.1 months. Minimum follow up is 24 months. Average age is 50 years. Comorbidities included 16 smokers, 4 diabetics, 6 previous surgeries, and 1 trauma. Patients wore an external orthosis for 6 weeks. of findings: There was one reoperation for junctional disease. Six patients developed junctional disease. Eight patients had residual radiographic lucent lines and/or hardware failure at most recent follow-up for a fusion rate of 94% (126 of 134) of patients and 97.8% (266 of 272 of levels). There were six instances of hardware failure and/or pseudarthrosis, four of which occurred in the three- and four-level group. Complications occurred in 12 patients (8.9%) and included dysphagia (4), vocal cord paralysis (1), fibrositis (1), respiratory distress (1), wound infection (1). Relationship between findings and existing knowledge: We believe this series to be the largest reported ACDF series with 2-year follow-up that includes three and four levels. Overall significance of findings: Extremely high fusion rates with only one reoperation were recorded in this series, including three- and four-level constructs, with an acceptable complication rate. We believe that outstanding results are obtainable with allograft and plate, even at three or four levels, when the principles of precise fit and fill of the interspace with a contoured graft and fixation, which facilitate compression are followed. We believe this series to be the largest reported ACDF series with 2-year follow-up that includes three and four levels. Disclosures: No disclosures. Conflict of interest: No conflicts.
A mathematical model of 2P and 2C vortex wakes

Abstract We present a mathematical model of the vortex wake modes that appear behind neighboring and/or oscillating, flapping, and swimming bodies in which there are four vortices generated in an anti-symmetric pattern during each shedding cycle. The two-dimensional potential flow model consists of four point vortices with strengths ± Γ in a spatially periodic domain. The relative vortex positions are restricted by a discrete symmetry that is motivated by the spatial symmetry observed in experimental wakes. The strength restriction and the imposed symmetry result in the model system being an integrable Hamiltonian dynamical system. We find that the point vortex motion can be one of four distinct types based on the values of linear impulse and Hamiltonian. Two of these types correspond to 2P wakes and consist of two oppositely signed, counter-rotating vortex pairs. One of these types corresponds to 2C wakes and consists of two like-signed, co-rotating vortex pairs. The fourth type is an exchanging mode in which the two vortices near the wake centerline translate faster than the outer two vortices. Scaled comparisons of the model with both a 2P and a 2C experimental wake show good representation of the experimentally observed vortex dynamics and lead to estimates of the experimental vortex strengths.
A matrix model for planning the training and development programs for employee groups

The paper first proposes a matrix model for the general classification of corporate training and development (T&D) objectives. A study is then initiated to test the model's structure. After obtaining support, survey data are used to derive first approximation values for individual cells within the model.
A Clinical Study of 1,000 Consecutive Cases of Mitral Stenosis Two to Nine Years after Mitral Valvuloplasty

A study is presented of 1,000 cases of predominant mitral stenosis operated by valvuloplasty between 1949 and 1956. It is shown that the survival of these patients is better than would have been expected under medical management. Sixty-nine per cent of the survivors of the operation in groups II and III improved, and 55 per cent in group IV. Factors influencing the late results are discussed. After substantial improvement lasting a year or more, 228 of this series deteriorated; the factors affecting this deterioration are discussed, of which mitral insufficiency, an inadequate valvuloplasty, and recurrent rheumatic fever are the most striking.
Psychology, law, and the workplace: an overview and introduction to the special issue.

According to a survey conducted by the National Sleep Foundation, the average person in the United States spends 46 hr a week at work and 38% of those surveyed reported working more than 60 hr a week. We spend significant portions of our lives in our respective workplaces and, as it is in other situations, our behavior at work is governed by a variety of laws. Some of these laws, such as those prohibiting murder or fraud, are not specific to the work environment; however, this behavior might manifest itself differently in the workplace than it does in other environments and therefore is worthy of attention. Other laws are specific to the workplace, such as laws prohibiting employment discrimination or wrongful termination. Laws governing employment in the United States have relied upon the employment-at-will doctrine. Under this doctrine, unless an employee has a contract guaranteeing employment for a specified period of time, he or she can be terminated at any time, for any or no specific reason. Various legislative acts have delineated exceptions to this doctrine. For example, employees cannot be terminated or denied employment because they participated in unionization activities (National Labor Relations Act), reported wage violations (Fair Labor Standards Act), reported health or safety violations (Occupational Safety and Health Act), or took advantage of the provisions of the Family Medical Leave Act of 1993. Employment decisions may not be based on an employee's membership in a protected class (race, color, sex, national origin, or religion; Title VII of the Civil Rights Act of 1964), age (Age Discrimination in Employment Act), or bankruptcy status (Section 525(b) of the Bankruptcy Code), nor can an employee be terminated to prevent that employee from vesting in a company pension plan (Employee Retirement Income Security Act of 1974). A person's disability may not be considered in employment decisions and an employer must provide any disabled employee or prospective employee with reasonable accommodations as long as doing so does not result in undue hardship for the employer (Americans With Disabilities Act, 1990). Some states have extended these federal antidiscrimination laws to include prohibitions against discrimination based on personal appearance, education, sexual orientation, and marital status.
Interpreting EEG functional brain activity

A critical issue in the presurgical evaluation of brain operations is mapping regions that control speech and language functions. The goal is to preserve these regions during surgery. Mapping done by electrically stimulating the cortex subdurally with implanted electrodes is highly effective, but introduces a high risk for cortical tissue injury. Mapping the brain with non-invasive techniques, such as EEG recordings, is possible. The object of our study is to show that the results produced could be effective and useful, without any risk to the patient. EEG data was collected using electrical source-imaging, with up to 256 electrodes (ESI-256 system). The EEG of each subject was recorded during an auditory/comprehension test using 41 key locations of the possible 256 according to the modified combinatorial nomenclature (MCN). The representations obtained allow us to highlight how different subjects react under similar auditory/comprehension tests, in order to assess the similarity/dissimilarity of brain functional patterns, and, potentially, to detect the presence of any associated neurological disorders. The study confirms that all frequency bands can be used to characterize, under distinct events, the activation associated with a well-established auditory/comprehension test.
Preparation of a Prespecified Interfacial Region by Cross Section Sampling for HREM Investigations

Thin polysilicon layers are used in microelectronics as a first metal level. With careful annealing, a doped polysilicon layer can also act as a diffusion source for the underlying Si substrate. For such a case, the quality of the polysilicon to substrate Si interface plays an important role in the electrical and migratory properties of the final structure. Therefore, the interface must be observed very closely. p]Arsenic doped polysilicon was deposited on a oriented Si wafer. Cross-section TEM specimen preparation was performed by first cutting dices centered on the prespecified region of interest. The dices are bounded face to face, and then a parallel double face mechanical polishing of the section reduces the thickness of the cross-section to about 30 microns. An ion milling operation is used to finish the preparation. Localisation precision by this method is not better than 100 microns, but this can be improved to 10 microns by replacing one of the dices with a piece of glass to allow visualization of the surface during polishing. p]The advantage of this method is that a large region can be observed, 1.5 mm long on each piece, with rather good localisation. p]An application is the HREM imaging of a typical interfacial region. We could see an ultrathin (1nm) amorphous layer running along the interface between the Si and the polysilicon. Physical characterization (EDXS, EELS) was obtainable from this ultrathin layer.
Factors Affecting 14C Ages of Lacustrine Carbonates: Timing and Duration of the Last Highstand Lake in the Lahontan Basin

Two processes contribute to inaccurate 14C age estimates of carbonates precipitated within the Lahontan basin, NevadaCalifornia: low initial 14C/C ratios in lake water (reservoir effect) and addition of modern carbon to calcium carbonate after its precipitation. The mast reliable set of 14C ages on carbonates from elevations > 1310 m in the Pyramid and Walker Lake subbasins indicate that lakes in all seven Lahontan subbasins coalesced ∼14,200 14C yr B.P. forming Lake Lahontan. Lake Lahontan achieved its 1330-m highstand elevation by ∼13,800 14 C yr B.P. and receded to 1310 m by ∼13,700 14C yr B.P. Calculations, based on measured carbonate-accumulation rates, of the amount of time Lake Lahontan exceeded 1310 and 1330 m (500 and 50 yr) are consistent with this chronology. The timing of the Lake Lahontan highstand is of interest because of the linkage of highstand climates with proximity to the polar jet stream. The brevity of the Lahontan highstand is interpreted to indicate that the core of the southern branch of the polar jet stream remained only briefly over the Lahontan basin.
Laboratory measurements of radar backscatter from bare and snow-covered saline ice sheets

Abstract We performed experiments to collect radar backscatter data at Ku (13.4GHz) and C bands (5.3GHz) over simulated sea ice at the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) during the 1990 and 1992 winter seasons. These experiments were conducted over bare saline ice grown in an indoor tank and an outdoor pond facility. The radar data were calibrated using a complex vector calibration scheme to reduce systematic effects. In conjunction with the radar measurements we measured ice physical properties These measurements demonstrate that the dominant backscatter mechanism for bare saline ice is surface scattering. Both the copolarized and cross-polarized measurements compare favourably with the predictions of surface scattering models at two frequencies During the 1992 indoor tank experiment we applied four successive layers of snow (about 2.5 cm each) to the saline ice sheet after the ice thickness had reached about 12 cm. The backscatter at normal incidence dropped by l5dB and t...
The Soft Stair: Falls Induced by a Laboratory Stair

This study is part of a research program directed at reducing stair injuries by absorbing much of the impact of a fall. Little is known about human kinetics during falls. The paper describes a laboratory stair that induces subjects to fall, but terminates the tumble before the stair is struck. The trajectory of the falling subjects provides insights into the nature of stair falls, and makes it possible to predict the forces that would be generated at impact.
Pion double charge exchange on 4 He

The doubly differential cross sections for the 4 He(� + ,� − )4p reaction were calculated using both a two-nucleon sequential single charge exchange model and an intranuclear cascade code. Final state interactions between the two final protons which were the initial neutrons were included in both methods. At incident pion energies of 240 and 270 MeV the low-energy peak observed experimentally in the energy spectrum of the final pions can be understood only if the contribution of pion production is included. The calculated cross sections are compared with data.
Predicting Functional Regions on Objects

We revisit the notion of object affordances, an idea that speaks to an object's functional properties more than its class label. We study the problem of spatially localizing affordances in the form of 2D segmentation masks annotated with discrete affordance labels. For example, we use affordance masks to denote on what surfaces a person sits, grabs, and looks at when interacting with a variety of everyday objects (such as chairs, bikes, and TVs). We introduce such a functionally-annotated dataset derived from the PASCAL VOC benchmark and empirically evaluate several approaches for predicting such functionally-relevant object regions. We compare "blind" approaches that ignore image data, bottom-up approaches that reason about local surface layout, and top-down approaches that reason about structural constraints between surfaces/regions of objects. We show that the difficulty of functional region prediction varies considerably across objects, and that in general, top-down functional object models do well, though there is much room for improvement.
Numerical Analysis of Flow Evolution in a Helium Jet Injected Into Ambient Air

A computational model to study the stability characteristics of an evolving buoyant helium gas jet in ambient air environment is presented. Numerical formulation incorporates a segregated approach to solve for the transport equations of helium mass fraction coupled with the conservation equations of mixture mass and momentum using a staggered grid method. The operating parameters correspond to the Reynolds number varying from 30 to 300 to demarcate the flow dynamics in oscillating and non-oscillating regimes. Computed velocity and concentration fields were used to analyze the flow structure in the evolving jet. For Re=300 case, results showed that an instability mode that sets in during the evolution process in Earth gravity is absent in zero gravity, signifying the importance of buoyancy. Though buoyancy initiates the instability, below a certain jet exit velocity, diffusion dominates the entrainment process to make the jet non-oscillatory as observed for the Re=30 case. Initiation of the instability was found to be dependent on the interaction of buoyancy and momentum forces along the jet shear layer.
Transparency in agency: The constant elasticity case and extensions☆

This paper considers a hidden action agency problem where the principal has a single source of hidden information concerning the agent's utility, the agent's effort productivity, or the agent's cost of effort. We examine whether the principal should precommit to disclosing these different single sources of information to the agent. If the optimal contract is invariant over the hidden information and, thus, the disclosure rules (constant elasticity case), such disclosure increases the agent's utility, it can raise or lower profit and total surplus depending on the source of hidden information, and non-disclosure can be optimal if disclosure affects the agent's motivation. If the contract varies with the hidden information and, thus, disclosure rule, disclosure or non-disclosure can be optimal depending on whether the party's payoff is convex or concave in the information variable, respectively.
Water-conducting System of Symphyogyna

THE gametophytes of the liverwort genera Hymenophyton, Podomitrium, Pallavicinia and Symphyogyna contain an internal water-conducting system, which is strikingly analogous to the xyleni of simple vascular plants. This system is composed of one or more strands of narrow diameter, elongate, thick walled, densely pitted conducting cells that are devoid of protoplasmic contents at maturity. The presence of this system was first noted by William Jackson Hooker1 in Jungermannia (now Pallavicinia) lyellii. Leitgeb2 pointed out that the cells of the strand were elongate, possessed oblique end walls and that the cell walls were considerably thickened and possessed close-set pores. Tansley and Chick3 reported that the contents of the cells of the conducting strand disintegrate during development and demonstrated that the strand is actually an efficient water-conducting unit within the thalli.
A new class of chaotic attractors in Murali-lakshmanan-chua circuit

In this paper, we study the existence of a new class of chaotic attractors, namely the rank-one attractors, in the MLC (Murali–Lakshmanan–Chua) circuit [Murali et al., 1994] by numerical simulations based on a theory of rank-one maps developed in [Wang & Young, 2005]. With the guidance of the theory in [Wang & Young, 2005], weakly stable limit cycles, found through Hopf bifurcations and other numerical means, are subjected to periodic pulses with long relaxation periods to produce rank-one attractors. The periodic pulses are applied directly as an input. Periodic pulses have been used before in various schemes of chaos. However, for this scheme of creating rank-one attractors to work, the applied periodic pulses must have short pulse widths and long relaxation periods. This is one of the key components in creating this new class of chaotic attractors.
Using simulation to interpret results from logit, probit, and other nonlinear models

In a recent issue of this journal, Glenn Hoetker proposes that researchers improve the interpretation and presentation of logit and probit results by reporting the marginal effects of key independent variables at theoretically interesting or empirically relevant values of the other independent variables in the model, and also by presenting results graphically (Hoetker, 2007: 335, 337). In this research note, I suggest an alternative approach for achieving this objective: reporting differences in predicted probabilities associated with discrete changes in key independent variable values. This intuitive approach to interpretation is especially useful when the theoretically interesting or empirically relevant changes in independent variables values are not very small, and also for models that contain interaction terms (or higher-order terms such as quadratics). Although the graphical presentations recommended by Hoetker implicitly embody this approach, they typically fail to include appropriate measures of statistical significance, and may therefore lead to erroneous conclusions. In order to calculate such measures, I recommend and demonstrate an intuitive simulation-based approach to statistical interpretation, developed by King et al. (2000), that has gained widespread adherence in the field of political science. Throughout the article, I provide a running example based on research that has previously appeared in the Strategic Management Journal. Copyright © 2009 John Wiley & Sons, Ltd.
Oxytocin potently enhances novelty-induced grooming behavior in the rat.

Intracerebroventricular (i.c.v.) injection of oxytocin was followed by an enhancement of novelty-induced grooming in male and female rats. This effect was dose-dependent, in a dose range of 0.1-10 micrograms. Grooming activity of rats injected i.c.v. with 10 micrograms of oxytocin was 9-fold higher than that of saline-injected controls. The analysis of behavioral element composition revealed an increased occurrence of genital grooming in oxytocin-injected rats. A time-course study revealed a sustained increase in grooming activity of oxytocin-treated rats during 45 min of behavioral testing. Intraperitoneal (i.p.) injection of the dopamine antagonist, haloperidol, totally suppressed oxytocin-enhanced grooming. Furthermore, i.p. injection of the opiate receptor antagonist, naloxone, was followed by an attenuation but not a suppression of grooming enhanced by i.c.v. administration of oxytocin. In addition, a small but significant increase in grooming activity was observed after subcutaneous injection of oxytocin. These results suggest that oxytocin-enhanced grooming behavior involves central mechanisms, e.g. dopamine and opioid transmission in the brain.
The clinical utility of the rectal-skin temperature difference in the assessment of young infants.

. Objective: Previous studies have suggested that the degree of difference between rectal temperature and peripheral skin temperature [rectal—skin temperature difference (RSTD)] is predictive of serious illness in young infants. The authors sought to determine the clinical utility of the RSTD in the outpatient evaluation of infants up to 2 months of age for serious infectious illness (SII). Methods: Simultaneous rectal and skin (anterior mid—lower leg) temperatures were recorded for all infants ≤2 months of age seen in the ED over a one-year period. The physician's clinical assessment, rectal temperature, skin temperature, laboratory results, and final diagnoses were also recorded. The RSTD (rectal temperature — skin temperature) was calculated for each infant. Final diagnoses were recorded and classified as SII or nonserious illness (NSI). Mean RSTD for each group was calculated and data were analyzed by the Wilcoxon rank sum test and multivariate regression model. Results: A total of 601 infants [mean age of 28 days (range 2-65 days)] were enrolled. Nine percent (57 of 601) of infants had SII. Forty percent (23 of 57) of infants with SII were febrile, and 60% (34 of 57) were afebrile. The mean RSTD of febrile infants with SII was 5.8 ± 1.7°C (range 3.2-9.7°C) and 5.3 ± 1.4°C (range 3.0-7.6°C) for febrile infants with NSI. The mean RSTD of afebrile infants with SII was 4.8 ± 1.8°C (range 2-12.5°C) and 4.4 ± 1.5°C (range 0.04-10.9°C) for afebrile infants with NSI. The RSTD was not associated with SII in either febrile or afebrile infants (p > 0.05, Wilcoxon rank sum test). A multivariate logistic regression model of age, rectal temperature, and RSTD suggested an independent association of rectal temperature with SII (p 0.05). Conclusion: Once the rectal temperature is known, the RSTD is not a clinically useful test in the evaluation of young infants for serious infectious illness.
Novel adaptation of brush cytology technique for short-term primary culture of squamous and Barrett's esophageal cells

Abstract Background: Esophageal disease research is impeded by a paucity of nonmalignant cell lines. Furthermore, culture of primary esophageal cells is difficult because of a lack of cell adhesion and contamination. The aim of this study was to develop a short-term culture method to facilitate cell physiologic studies by using primary esophageal cells. Methods: By using a cytology brush, squamous and Barrett's epithelial cells were obtained from the esophagus of patients undergoing upper endoscopy. Cells were brushed onto chamber slides and allowed to adhere to the surface. Primary culture media was then added and cells were maintained at 37°C for up to 72 hours. Cell yield and viability were calculated after trypan blue staining. For cell physiologic studies, cells were loaded with pH-sensitive dye BCECF-AM and intracellular pH measured on a dual excitation fluorescence microscope after an ammonium chloride prepulse. At the end of the physiologic experiments, cells were fixed in methanol and acetone and the cell type was verified with cytokeratin immunocytochemistry. Results: Viable human esophageal cells were maintained in culture for up to 72 hours. The cells extruded trypan blue, and BCECF-AM was cleaved to BCECF by an intact cell membrane and permitted intracellular pH measurements. The epithelial cell origin of the cells was confirmed by cytokeratin staining. There was no contamination over the culture period and no overgrowth by lymphocytes or fibroblasts. Conclusions: This novel adaptation of brush cytology technique enables short-term culture of esophageal cells for in vitro studies. This rapid, simple primary culture technique is suitable for endoscopy and does not require the immediate, time-consuming laboratory techniques. (Gastrointest Endosc 2001;54:186-9.)
Measurement of rate constants for actin filament elongation in solution

This paper describes a simple method to measure the rate constants for actin filament elongation using pyrene-actin fluorescence as a measure of the polymer concentration and unlabeled actin filaments as nuclei. With careful selection of conditions, the initial rate of polymerization is directly proportional to the actin monomer concentration above the critical concentration. Plots of initial rate versus actin concentration give the critical concentration (x intercept), the association rate constant, k+ (slope), and the dissociation rate constant, k-(y intercept). By calibrating the system under conditions where the absolute values of these rate constants are known from previous electron microscopic experiments [T. D. Pollard and M. S. Mooseker (1981) J. Cell Biol. 88, 654-659; J. A. Cooper, S. B. Walker, and T. D. Pollard (1983) J. Muscle Res. Cell Motil. 4, 253-262], one can calculate the absolute values of the rate constants under other conditions as well as the length of the filaments used as a nuclei. This approach has proven useful for evaluating the effect of actin-binding proteins on the polymerization process.
Hepatic export of glutathione and uptake of constituent amino acids, glutamate and cysteine, in broilers in vivo

Abstract This study was conducted to document the glutathione (GSH) cycle (interorgan circulation of GSH) in broilers in vivo. Two experiments were conducted on 36 anesthetized male broilers (n = 6 per treatment) implanted with cannulae in the carotid artery, hepatic portal, and hepatic veins. Plasma GSH, glutamate, cysteine, cystine, and cysteinylglycine levels in each vessel were monitored following a bolus injection [Experiment (Exp.) 1] or 30 min continuous infusion (Exp. 2) of GSH, or a gamma-glutamyltranspeptidase inhibitor (AT125) into the hepatic portal vein. Controls received saline alone. The GSH and AT125 treatments were used to determine the effect of increasing the prehepatic GSH load and of inhibiting systemic GSH degradation, respectively, on the GSH cycle. Hepatic export of GSH was clearly evident in all three treatment groups in both experiments (Exp.). The GSH and AT125 treatments raised amino acid levels in some or all of the vessels, whereas cysteinylglycine was elevated by AT125 and depressed by the GSH treatment compared to Controls. Hepatic uptake of glutamate, cysteine, and/or cystine was observed in Controls and GSH-treated birds, but not in birds given AT125 (Exp. 2). Neither hepatic export nor uptake of cysteinylglycine was observed in any treatment group. The results clearly demonstrate the ability of the avian liver to export GSH into the general circulation despite alterations that might arise from changes in extra-hepatic ability to utilize GSH or its constituent amino acids.
Synthesis of 100-gram quantities of highly purified mixed acid triglycerides

Monopalmitin, mono-olein, and monostearin have been synthesized in quantities of up to 100 grams with recoveries ranging from. 80%-85%. The monoglycerides were reacted with a 0.5 molar excess of pyridine and fatty acid chloride to produce 1, 3,-diglycerides. The recoveries ranged from 60%-70% and, in addition, considerable amounts of triglyceride were obtained from this reaction. Partial glycerides were converted to 100-gram batches of triglyceride in a similar manner with recoveries ranging from 80%-90%. Purification of the partial glycerides was achieved by crystallization. In addition to this technique, certain triglycerides were purified by elution through a column of alumina. Purity of the glycerides, as determined by TLC, G-LC, and pancreatic lipolysis, was estimated to be at least 99%.
Collected Papers on the Philosophy of Chemistry

Once when advising an entering college student, some years ago, as to his proper placement in my college's array of chemistry courses I asked what previous exposure to chemistry he had had. Upon se...
J. C. Nichols and the Shaping of Kansas City: Innovation in Planned Residential Communities

Born and reared on the outskirts of Kansas City in Olathe, Kansas, Jesse Clyde Nichols (1880-1950) was a creative genius in land development. He grew up witnessing the cycles of development and decline characteristics of Kansas City and other American cities during the late nineteenth and early twentieth centuries. These early memories contributed to his interest in real estate and led him to pursue his goal of neighborhoods in Kansas City, an idea unfamiliar to that city and a rarity across the United States.J.C. Nichols was one of the first developers in the country to lure buyers with a combination of such attractions as paved streets, sidewalks, landscaped areas, and access to water and sewers. He also initiated restrictive covenants and to control the use of structures built in and around his neighborhoods.In addition, Nichols was involved in the placement of services such as schools, churches, and recreation and shopping areas, all of which were essential to the success of his developments. In 1923, Nichols and his company developed the Country Club Plaza, the first of many regional shopping centers built in anticipation of the increased use of automobiles. Known throughout the United States, the Plaza is a lasting tribute to the creativity of J.C. Nichols and his legacy to the United States.With single-mindedness of purpose and unwavering devotion to achievement, J.C. Nichols left an indelible imprint on the Kansas City metropolitan area, and thereby influenced the design and development of major residential and commercial areas throughout the United States as well. Based on extensive research, "J.C. Nichols and the Shaping of Kansas City" is a valuable study of one of the most influential entrepreneurs in American land development.
Cross-lingual relevance models

We propose a formal model of Cross-Language Information Retrieval that does not rely on either query translation or document translation. Our approach leverages recent advances in language modeling to directly estimate an accurate topic model in the target language, starting with a query in the source language. The model integrates popular techniques of disambiguation and query expansion in a unified formal framework. We describe how the topic model can be estimated with either a parallel corpus or a dictionary. We test the framework by constructing Chinese topic models from English queries and using them in the CLIR task of TREC9. The model achieves performance around 95% of the strong mono-lingual baseline in terms of average precision. In initial precision, our model outperforms the mono-lingual baseline by 20%. The main contribution of this work is the unified formal model which integrates techniques that are essential for effective Cross-Language Retrieval.
Lysine deficiency and feed restriction independently alter cationic amino acid transporter expression in chickens (Gallus gallus domesticus)

The effect of a lysine-deficient diet on cationic amino acid transporter (CAT1-3) mRNA expression was determined in broiler chickens. Chicks consumed a lysine-adequate (LA; 1.3% lysine) or lysine-deficient (LD; 0.7% lysine) diet. Pair-fed chicks consumed the LA diet in an amount equal to that consumed by LD chicks during the previous day (PLA). CAT 1-3 mRNA expression in the liver, pectoralis and bursa of LD chicks were lower than that of LA and PLA chicks (P < 0.05), and levels were not detectable in LD chick thymus. High affinity CAT mRNA expression in isolated bursacytes was 16-fold higher in LD chicks than that of LA chicks (P < 0.001). Thymocyte high affinity CAT mRNA expression was 5-fold lower than that of LA chicks (P < 0.05). The summed amount of high affinity CAT-1 and CAT-3 mRNA expression in chicks fed a lysine adequate diet was highly correlated (r2 = 0.51; P < 0.001) to a tissue's growth during a lysine deficiency or feed restriction. In the thymus and bursa of LD chicks, CAT mRNA levels differed between resident lymphocytes and their surrounding tissues. By expressing high affinity CAT isoforms, developing lymphocytes may have a greater ability to obtain lysine than their surrounding tissue during a lysine deficiency.
Politically Optimal Fiscal Policy

Why do governments issue large amounts of debt? In what sense and for whom is such a policy optimal? We show that twisting the optimal taxation paradigm produces very reasonable predictions for debt and real interest rates. Adding an extra dimension of uncertainty about the political planning horizon gives rise to a positive and very plausible government debt-to-GDP ratio of about 55 percent in a model that otherwise predicts negative government debt. We quantify the impact of political uncertainty on steady state and business cycle dynamics. We illustrate how populist tax cuts can cause business cycle fluctuations.
Mediation of insulin hyperphagia by specific central opiate receptor antagonists

The hyperphagic properties of insulin (10 U/kg, s.c.) were transiently (2 h) and dose-dependently inhibited (30%) by central pretreatment with naltrexone (20–50 μg, i.c.v.). The irreversible μ opioid antagonist, β-funaltrexamine (B-FNA, 20 μg, i.c.v.) significantly inhibited insulin hyperphagia by 28–54% over the 6-h time course. In contrast, insulin hyperphagia was only transiently (2 h) inhibited (27–30%) by either the irreversible μ1 antagonist, naloxonazine (50 μg, i.c.v.) or the selective κ antagonist, nor-binaltorphamine (NorBNI, 20 μg, i.c.v.). The δ-antagonistic actions of [d-Ala2, Leu5, Cys6]-enkephalin (DALCE, 40 μg, i.c.v.) failed to affect insulin hyperphagia. These data suggest that the μ2 opioid receptor subtype modulates insulin hyperphagia.
Extreme intracardiac coiling of a transvenous pacemaker: a case report.

We report an unusual complication of transvenous pacing: extreme coiling of a pacemaker catheter, which formed a redundant, twisted loop protruding into the right ventricular outflow tract. This may be a result of “tividdling” (rotation) of the pacemaker generator by the patient and/or inadequate fixation of the catheter at the venous entry site. Careful fixation of the generator to the venous entry site within the subcutaneous pocket may prevent such a complication.
Wiberg's Review Essay on Rummel: A Reply:

HAkan Wiberg' review essay (JPR, No. 4, 1982) on my five-volume Understanding Conflict and War (UCW) unintentionally provides an empirical test of an error assumption I applied to evaluate my propositions. In Volume 4 I tabulated the analyses of 317 quantitative international relations studies as to whether they supported or opposed 54 propositions on conflict, war, and peace. To these tabulations I also applied a one-level decrement to account for any possible bias of mine in favor of the propositions (see Vol. 4, Tables 15A.5, 16C.4, 17A.4, and 18A.3). The overall results are shown in Table I, below.
Chromosomes and cancer cells

Two prominent features of cancer cells are abnormal numbers of chromosomes (aneuploidy) and large-scale structural rearrangements of chromosomes. These chromosome aberrations are caused by genomic instabilities inherent to most cancers. Aneuploidy arises through chromosomal instability (CIN) by the persistent loss and gain of whole chromosomes. Chromosomal rearrangements occur through chromosome structure instability (CSI) as a consequence of improper repair of DNA damage. The mechanisms that cause CIN and CSI differ, but the phenotypic consequences of aneuploidy and chromosomal rearrangements may overlap considerably. Both CIN and CSI are associated with advanced stage tumors with increased invasiveness and resistance to chemotherapy, indicating that targeted inhibition of these instabilities might slow tumor growth. Here, we review recent efforts that define the mechanisms and consequences of CIN and CSI.
Trinexapac-ethyl and iron effects on supina and kentucky bluegrasses under low irradiance

Turf use in covered stadiums and other environments with reduced irradiance is limited due to lack of suitable turf species and manage. ment practices. This study compared the tolerance of supina bluegrass (Poa supina Schrad.) and Kentucky bluegrass (P. pratensis L.) with reduced irradiance of approximately 1 to 5 mol m 2 d -1 . Treatments included trinexapac-ethyl {[4-(cyclopropyl-α-hydroxy-methylene)-3.5-dioxo-cyclohexane-carboxylic acid ethyl ester]} (TE), foliar iron, and simulated athletic traffic inside a covered stadium simulator facility. Analysis of variance showed supina bluegrass was more responsive to TE than Kentucky bluegrass. Trinexapac-ethyl reduced supina blue prass clipping yields approximately 60%; Kentucky bluegrass yields were reduced by 20% or less, In non-trafficked turl, TE increased supina bluegrass tillers by 50% and leaves by 33% but did not change tillering and leaf number of Kentncky bluegrass. Without traffic, TE-treated supina bluegrass provided an acceptable turf at 10 to 15% solar irradiance for at least 4 to 6 mo, while Kentucky bluegrass and untreated supina bluegrass became unacceptable within 2 to 4 mo. Under traffic. TE-treated supina bluegrass provided acceptable turl for up to 5 wk, while Kentucky bluegrass did not provide acceptable turf for more than 2 to 4 wk. Trinexapac-ethyl enhanced supina blue-grass color and increased chlorophyll levels of both species. Foliar applications of iron had negligible effects on all of the parameters evaluated. Supina bluegrass is a useful turf for reduced irradiance sitpations but requires more than 5 mol m 2 d -1 to sustain traffic for periods longer than 5 wk.
Multiphoton ionization of N(2) by the third harmonic of a Nd:YAG laser: a new avenue for air diagnostics.

Laser-induced N2 ionization is accomplished using a commercially available Nd:YAG laser, and confirmed by means of ion-collection and spectral measurements. Neutral N2 is excited by six photons of the third harmonic frequency, or 355 nm, and is transformed to an ionized state. The radiation at 355 nm is separated from the fundamental and frequency-doubled Nd:YAG radiation to guarantee monochromatic incident radiation. Intense lines near 391.4 nm are found in the initial laser polarization and for a 90-degree rotation of polarization. The radiation at 391.4 nm is associated with an incoherent laser-induced flourescence process related to an ionized-state transition, and increases quadratically with laser power. A 45-mJ laser pulse focused to a diameter of 17 microns can produce an ion concentration of 3.25 x 10 to the 13th ions/cu cm. The large ion concentration and robust fluorescence signal make this technique an efficient method for time-of-flight velocimetry and in-flight testing.
Micro- (and nano-) mechanical signal processors

With quality factors (Q) often-exceeding 10,000, vibrating micromechanical resonators have emerged as leading candidates for on-chip versions of high-Q resonators used in wireless communications systems. However, as in the case for transistors, extending the frequency of MEMS resonators generally entails scaling of resonator dimensions. Unfortunately, smaller size often coincides with lower-power handling capability and increased motional impedance. In this paper we introduce novel transduction techniques which can improve the motional impedance of MEMS resonators by 1000× over traditional 'air-gap' transduced resonators, present latest results on narrow-bandwidth parametric filters for frequency-agile radio receivers, and discuss performance scaling of NEMS resonators to X-band frequencies.
A Study on the High Speed Face Milling of Ti-6Al-4V Alloy

This paper is concerned with the experimental and numerical study of the high speed face milling of Ti-6Al-4V titanium alloy. Machining is carried out by uncoated carbide and polycrystalline diamond cutters in the presence of an abundant supply of coolant. Experimental analysis is conducted in terms of cutting forces, chip morphology, surface integrity and tool wear. The experimental analysis is supplemented by simulations from the finite element analysis where needed. The highest cutting speed realized for both the cutting tool materials is 600 sfpm with the diamond cutter operating at feeds lower than that for carbide. Good surface integrity in terms of residual stress and surface finish is achieved under the machining conditions used with limited tool wear. Residual stresses imparted to the machined surface are compressive with the diamond tool yielding higher values and are the most sensitive to feed. Tool wear patterns are described in terms of various cutting conditions.Copyright © 2002 by ASME