cssi/SciSciGPT-SciSciNet huggingface dataset:
Convergence in almost periodic Fisher and Kolmogorov models

We study convergence of positive solutions for almost periodic reaction diffusion equations of Fisher or Kolmogorov type. It is proved that under suitable conditions every positive solution is asymptotically almost periodic. Moreover, all positive almost periodic solutions are harmonic and uniformly stable, and if one of them is spatially homogeneous, then so are others. The existence of an almost periodic global attractor is also discussed.
Homework for the Psychotherapeutically Sophisticated Client

Abstract This strategy is ideal for helping therapists in treatment. It is also highly effective when attempting to help students studying counseling, psychiatry, social work, psychology, or other individuals who have a greater than average knowledge of the psychotherapeutic process.
User lifecycles in cyclopath: a survey of users

To be online, for most people, means to be part of some online communities, but the moment you visit a website, you are beginning your user lifecycle with that site. Previous quantitative work has shown that the early stages of the user lifecycle are the most important. We asked 400 users of the Cyclopath geowiki to complete a survey asking, among other things, about why they chose to register and what their first experiences on the site were. The responses allow us to think more carefully about the difficult barrier of registration and how this may be impacting the user lifecycles on Cyclopath and other online communities.
Impurity Doped Simple Metal Clusters: Optical Response

Existing and future measurements of the optical response properties of monodoped simple metal clusters are discussed.
Inflammatory tales of liver cancer.

Cell culture studies have established NF-κB's critical role in cancer cell survival and proliferation and led to the clinical use of NF-κB inhibitors. However, a paper in this issue of Cancer Cell reveals an anticancer function for NF-κB in a mouse model where NF-κB activity is lost specifically in hepatocytes. These studies suggest careful examination of NF-κB inhibitors as a therapeutic modality for cancer.
Identifiability and identification of switched linear biological models

Pulse is often used to excite biological systems. The inputs such as irrigation, therapy, and treatments to biological systems are also equivalent to pulses. This makes the biological system behave as switched models under the function of the input. To reduce difficulty in model parameter estimation, the system could be represented as a switched linear model under the pulse excitation. In this research, we studied the identification of a class of switched linear biological models with single input and the system matrix dependent on the intensity of excitation. System identifiability and identification were discussed. A recurrent-pulse excitation method was devised to provide necessary constraints for parameter estimation. The recurrent-pulse technique allowed determination of model parameters that would otherwise be difficult to determine uniquely. The usefulness of the method was demonstrated by examples including delayed fluorescence from photosystem II, which was well known as a versatile tool for sensing plant physiological status and environmental changes in the literature.
Glucose concentration monitoring using a small Fabry-Pérot etalon

Accurate measurements of aqueous glucose concentrations have been made in a double-chamber Fabry-Perot etalon that can be miniaturized for subcutaneous implantation to determine the concentration of glucose in interstitial fluid. In general, optical approaches to glucose detection measure light intensity, which in tissue varies due to inherent scattering and absorption. In our measurements, we compare the spectral positions of transmission maximums in two adjunct sections of an etalon in order to determine the refractive index difference between these sections and therefore we can tolerate large changes in intensity. With this approach, we were able to determine aqueous glucose concentrations between 0 mg/dl and 700 mg/dl within the precision of our reference measurement (±2.5 mg/dl or 2% of the measurement value). The use of reference cavities eliminates interference due to temperature variations, and we show the temperature independence over a temperature range of 32°C to 42°C. Furthermore, external filters eliminate interference from large molecule contaminants.
Electrostatic effects between adsorbed species—the K … Co interaction on Ni(111) as studied by infrared reflection-absorption spectroscopy

Abstract Using infrared reflection-absorption spectroscopy (IRAS), TPD and LEED, we have made a detailed study of CO coadsorbed with potassium on Ni(111). Both long range delocalized and short range localized potassium-CO interactions are observed at both low and high potassium coverages. Using the high resolution of IRAS, we estimate the lateral range of the long range K-CO interaction to be ≈ 25 CO molecules per potassium atom at the lowest potassium coverage studied. We explain the long range K-CO interaction in terms of a through-space electrostatic interaction and the observed decrease in the CO vibrational frequency in terms of the vibrational Stark effect. Finally, short range K-CO interactions, possibly due to the formation of a potassium-CO complex, are suggested by TPD and IRAS results.
Radionuclide Mineral Studies:, Relation of Breed, Age, and Vitamin B12 to Inorganic S35 Metabolism in Chicks

Investigation of the effect of vitamin B/sub 12/ on the ability of the young chick to incorporate inorganic S/sup 35/ in bone tissue, when fed both simplified and practical type diets, indicated that, of the skeletal structures examined, the sternum was generally the most active site of inorganic S/sup 35/ incorporation. This may be due-to its higher content of cartilage tissue than tibia. A significantly higher growth response was observed from chicks fed rations supplemented with vitamin B/sub 12/. White Leghorn chicks consistently showed a higher S/sup 35/ uptake rate over that exhibited by the New Hampshire and the White Leghorn x New Hampshire cross. Vitamin B/sub 12/ increased the uptake and retention of the inorganic S/sup 35/ in chicks when fed as a supplement to a simplified ration containing purified soybean protein. The presence of the vitamin as a supplement to a practical type ration decreased the ability of the chick to incorporate inorganic S/sup 35/. The presence of vitamin B/sub 12/ in the S/sup 35/O/sub 4/ dose admin istered to chicks gave a markedly higher rate of isotope absorption into the blood than the S/sup 35/O/sub 4/ alone. (TCO)
Income Tax Reform and Inequality: A Nonparametric Analysis

Suppose the adoption of an income tax system by a government is guided by two objectives. The revenue objective requires that a sufficient amount of tax revenue should be collected. The equity objective dictates that the disposable income should be distributed with a degree of in equality that is acceptable as a social consensus. The purpose of this article is, by using nonparametric analysis, to evaluate the actual magnitude and direction of changes of a tax structure imposed by an objective-oriented tax reform. 1990 census data of the U.S. are used. The analysis is applied to the United States as a whole and the 50 states individually. Finally, given the tax receipts and equity level of the current tax schedule, an equivalent flat tax structure is derived.
The siren, the muse, and the god of love: Music and gender in seventeenth‐century English emblem books

Abstract The emblem book, a collection of cryptic visual images accompanied by a motto and poetic epigram in Latin or the vernacular, was one of the most popular forms of early modern literature. It called upon the interplay between sensation and intellect, particularly auditory and visual pathways to understanding. The genre reached its apotheosis during the seventeenth century. Although these important compendia of culturally significant images have tended to remain outside the domain of musicology, they include numerous images of music which provide vital clues about its place in late Renaissance and early Baroque culture. One of the most striking and neglected features of seventeenth‐century English emblem books is the consistent, didactic gendering of music, in which that which empowers, revitalizes, or inspires to noble action is most often depicted as masculine; and that which seduces, corrupts, or entertains sense before intellect is most frequently presented in feminine form. This essay demonstra...
AP-S Turnstile: Is there anybody there?

Like the bemused traveler in Walter de la Mare's cele brated poem, we have been wondering for a long time if anyone else is out there in the universe. In a recent testimony before a House Committee on Science, Seth Shostak, senior astronomer at the SETI Institute [2], offered the following optimistic assessment [3]: It's unproven whether there is any life beyond Earth. I think that situation is going to change within everyone's lifetime in this room.
Eukaryotische Zelle: Symbiose statt Endosymbiose?

Noch heute werden in vielen Lehrbuchern die DNA-haltigen Organellen Mitochondrien und Chloroplasten als “semiautonome Endosymbionten” bezeichnet. Neue Berechnungen von DNA-Sequenzdaten zeigen, dass die eukaryotische Zelle und ihre Charakteristika wie Zellkern, Membransysteme und Mitochondrien [1] vermutlich nicht durch Aufnahme/Endosymbiose entstanden, sondern durch eine Fusion aus Archaea- und Bakterien-Zellen.
Hydroxyl stabilization on iron surfaces by chlorine interactions

Abstract We have used X-ray photoelectron spectroscopy (XPS) to study the surface chemistry of H 2 O and chlorine on a polycrystalline Fe surface. Our results indicate that the sequence in which the sample is exposed to H 2 O and chlorine significantly alters the interaction on the Fe surface. On Cl 2 /H 2 O/Fe (i.e., exposed to H 2 O first) disproportionation of Cl 2 is observed resulting in formation of HCl and a OHCl complex, (OHCl) a . HCl desorbs from the surface adlayer below 200 K. An important result is that (OHCl) a is stable on the surface to about 700 K in sharp contrast to OH adsorbed on a clean Fe surface, where desorption occurs below 300 K under UHV conditions. On the H 2 O/Cl 2 /Fe surface OH also desorbs below 300 K, indicating no ClOH stabilization. The effect of dosing sequence is attributed to the disproportionation of Cl 2 within the Cl 2 /H 2 O/Fe adlayer. Initial adsorption of Cl 2 results instead in FeCl formation and weak interaction with adsorbed OH. The results emphasize the importance of solvation effects on impurity induced H 2 O-surface interactions.
A novel methodology for querying web images

Ever since the advent of Internet, there has been an immense growth in the amount of image data that is available on the World Wide Web. With such a magnitude of image availability, an efficient and effective image retrieval system is required to make use of this information. This research presents an effective image matching and indexing technique that improvises on existing integrated image retrieval methods. The proposed technique follows a two-phase approach, integrating query by topic and query by example specification methods. The first phase consists of topic-based image retrieval using an improved text information retrieval (IR) technique that makes use of the structured format of HTML documents. It consists of a focused crawler that not only provides for the user to enter the keyword for the topic-based search but also, the scope in which the user wants to find the images. The second phase uses the query by example specification to perform a low-level content-based image match for the retrieval of smaller and relatively closer results of the example image. Information related to the image feature is automatically extracted from the query image by the image processing system. A technique that is not computationally intensive based on color feature is used to perform content-based matching of images. The main goal is to develop a functional image search and indexing system and to demonstrate that better retrieval results can be achieved with this proposed hybrid search technique.
THE ELEVATOR DISPATCHING PROBLEM: HYBRID SYSTEM MODELING AND RECEDING HORIZON CONTROL

Abstract Elevator dispatching is a combinatorially hard problem with many control constraints, time-varying traffic patterns, partial state information, and random effects. We develop a hybrid system model of a building with multiple elevator cars and apply a receding horizon control approach, bypassing some of the problem's complexities. Thus, we obtain a “universal” dispatcher which is robust with respect to changing traffic patterns and avoids the problem of having to switch among different controllers when these patterns change over the course of a day (as currently done). Moreover, simulation results show that the performance of this approach improves upon that of state-of-the-art dispatchers.
Hispanic Immigrant Children's English Language Acquisition: The Role of Socioeconomic Status and Early Care Arrangement

Research Findings: Using nationally representative data from the Early Childhood Longitudinal Study–Kindergarten cohort, this study investigates whether socioeconomic status (SES) moderates the association between center-based early childhood education (ECE) and English proficiency at kindergarten entry for 1st- and 2nd-generation Hispanic immigrant children. Results show significant, positive main effects of ECE and SES on English proficiency. However, results also reveal that the association between ECE and English proficiency differs by SES. Among 1st- and 2nd-generation Hispanic children from very low-SES households, the odds of being proficient in English for children who attended ECE is more than double the odds for children who did not attend ECE. In contrast, the association between ECE and English proficiency for higher SES children did not reach significance. Additional analyses reveal similar patterns for income but not maternal education. Practice or Policy: These results highlight the need fo...
Mother–Daughter Dyad Recruitment and Cancer Intervention Challenges in an African American Sample

Developing an effective youth-based health messaging intervention for African American women, who remain disparately impacted by cancer, presents unique challenges. This paper reports on the challenges with recruiting familial dyads from predominantly low-income, African American neighborhoods, as well as the challenges associated with designing and implementing an upward-directed cancer-screening intervention. We developed and pilot-tested an educational workshop that provided adolescents with cancer-screening information to share with their mother or female relative. Data from follow-up interviews and focus groups, as well as observation records regarding implementation obstacles, highlight important lessons learned. The use of familial dyads as well as issues of access posed challenges for recruitment and follow-up. Workshop-related challenges stemmed from the approach, content, and length. Finally, personal and environmental factors presented barriers to adolescent message delivery and adult follow-through. By identifying these challenges, we hope to influence and enable the future development of effective adolescent-initiated health-messaging interventions.
Analysis of acetylcholinesterase synthesis and transport in the rat hippocampus: recovery of acetylcholinesterase activity in the septum and hippocampus after administration of diisopropylfluorophosphate

The site and rate of synthesis, as well as the transport dynamics, of newly synthesized acetylcholinesterase (AChE) has been studied in the septum and hippocampus of the rat. Histochemical and biochemical techniques were employed to study time-dependent changes in AChE activity of the medial septal nucleus and hippocampus following systemic administration of the anticholinesterase diisopropyl-fluorophosphate. In both septum and hippocampus, an initially rapid phase of recovery was followed by a slower recovery with similar rate constants for the two regions. Analysis of AChE synthesis in the septo-hippocampal system revealed that recovery of activity in the septum(t1/2for recovery= 140h) preceded that in the hippocampus(t1/2for recovery= 400h). The data suggested that the bulk of septal AChE in the hippocampus is transported via the slow component of axoplasmic flow (about 2 mm/day). A fast component may exist, but the experimental arrangement did not permit the clear demonstration of any rapid axoplasmic flow.
Solar flux density distributions on central tower receivers

An analytical formulation of the solar flux density distributions produced on the surface of a central tower receiver by large mirror fields is developed which accounts for dispersion, shading and screening effects of mirrors, and for degradation of insolation levels. In the case of symmetrical geometries involving circular mirror fields and vertical cylindrical receivers, a general method of calculation yields closed-form solutions for the concentration ratios in terms of normalized parameters describing the mirror field configuration, the receiver dimensions, the insolation levels, the mirror characteristics, and the time of the day. Aiming strategies of mirror focusing are devised to reshape the solar flux in accordance with desired distributions. Mirror field asymmetries created by the configuration itself or by operational conditions blanking a portion of the field (due, for instance, to maintenance or cloud cover) are shown to set up flux gradients around the receiver which can be computed using a flux superposition technique. The methodology elaborated in the case of the vertical cylindrical receiver for simplicity and insight of treatment is applicable to many other geometries presently envisioned in receiver studies for solar power tower systems.
Three-dimensional kinematics of saccadic and pursuit eye movements in humans: relationship between Donders' and Listing's laws.

Abstract For Listing’s law to be obeyed during eye movements, the “half-angle rule” must be satisfied: the eye velocity axis must tilt away from Listing’s plane by half the angle of eye position eccentricity from primary position. We aimed to determine if this rule is satisfied during horizontal and vertical pursuit compared with saccades. Three-dimensional (3-d) eye rotation data were acquired from five normal head-fixed humans using the search coil technique. Saccades were recorded in response to 40° horizontal or vertical steps in target position, at different elevations and azimuths. Pursuit was recorded while tracking a target moving horizontally or vertically at 20°/s, with peak-to-peak amplitude of 40°, at the same elevations and azimuths. First- and second-order surfaces were fitted to 3-d eye position data from periods of fixation. In all subjects, eye positions did not lie on a planar surface, but on a twisted surface in 3-d space. The tilt-angle coefficient (TAC) during saccades and pursuit was calculated as the ratio of the angle of eye velocity axis tilt to the angle of eye position eccentricity. During horizontal saccades and pursuit, mean TACs were 0.58 and 0.64, respectively. During vertical saccades and pursuit, mean TACs were 0.35 and 0.43, respectively, and lower than their horizontal counterparts (p
Emma Willard and the graphic foundations of American history

Abstract Emma Hart Willard (1787–1870) authored one of the most widely printed textbooks of United States history, and created the first historical atlas of the United States. By drawing maps, graphs, and pictures of the country's past, Willard helped translate the fact of the country as a physical entity into the much more powerful fact of the country as a nation. Given the current academic preoccupation with the production, experience, and depiction of space, Willard's experimentation with the relationship of history and geography is highly worthy of close attention. Willard used the spatial dimension of the American past to engage students, develop their memories, integrate history and geography, and—most importantly—to consolidate national identity. In the process, learning itself became an act of nationalism.
Hypothalamic obesity: comparison of radio-frequency and electrolytic lesions in male and female rats.

Obesity-inducing lesions of the ventromedial hypothalamus (VMH) have generally been produced by passing anodal electrolytic current through a stainless steel electrode, which in addition to tissue ablation leaves deposits of metallic ions that might chronically irritate surrounding tissue. Although a few early investigators reported that nonirritative lesions (i.e., those that do not leave deposits) resulted in little or no obesity, their results were largely ignored when others observed substantial weight gain in animals after using the same techniques. The results of the present experiment suggest that these discrepancies were the result of a sex difference (the former group of studies all used male rats, while the latter group all used females). Male rats in the present study gained less than 80% of the weight gained by female rats regardless of lesion type, while rats with nonirritative radio-frequency lesions gained about 60% of the weight gained by rats with electrolytic lesions regardless of sex. Thus, female rats with radio-frequency lesions displayed substantial (albeit suppressed) weight gain, whereas male rats with identical lesions gained only slightly more weight than sham-lesioned controls. It is concluded that obesity resulting from electrolytic lesions of the VMH is due in part to tissue ablation and in part to chronic irritation (possibly of parasympathetic efferents mediating insulin release).
The effect of exposure to hypergravity on pregnant rat dams, pregnancy outcome and early neonatal development

Abstract We previously reported that hypergravity exposure affects food intake and mass gain during pregnancy. In the present study, we explored the hypothesis that changes in maternal body mass in hypergravity-exposed pregnant rat dams affect pregnancy outcome and early offspring development. Furthermore, we hypothesized that the changes observed at 1.5G will be magnified at higher gravity and by exposure during critical developmental periods. To test this hypothesis, we compared maternal body mass gain, food consumption, birth outcome and early offspring development between Sprague–Dawley rat dams exposed to graded (1.5–1.75G) chronic hypergravity (HG) or rotation (rotational control, RC) on a 24-ft centrifuge for 22.5 h starting on gestational day (G) 10 with dams housed under identical conditions but not exposed to hypergravity (SC). We also compared maternal body mass, food consumption, birth outcome and early offspring development between rat dams exposed to 1.65G during different stages of pregnancy and nursing. Exposure to hypergravity resulted in transient loss in body mass and prolonged decrease in food consumption in HG dams, but the changes observed at 1.5G were not magnified at 1.65G or 1.75G. On the other hand RC dams gained more mass and consumed more food than SC dams. Exposure to hypergravity also affected pregnancy outcome as evidenced by decreased litter size, lowered neonatal mass at birth, and higher neonatal mortality; pregnancy outcome was not affected in RC dams. Neonatal changes evidenced by impaired righting response observed at 1.5G was magnified at higher gravity and was dependent on the period of hypergravity exposure. On the other hand, righting response was improved in RC neonates. Hypergravity exposure during early postpartum affected the food consumption of nursing mothers and affected early survival of their offspring. The changes observed in dams and neonates appear to be due to hypergravity exposure since animals exposed to the rotation during the same period are not affected. This study suggests that while pregnancy can proceed under altered gravity, exposure to hypergravity affects pregnant dams, pregnancy outcome and the developing fetus as well as nursing dams and neonates and raises an important question whether the mammalian system possess a gravisensing ability.
An Enzymatic System for Removing Heparin in Extracorporeal Therapy

The need to fully heparinize patients undergoing extracorporeal therapy often leads to hemorrhagic complications. To enable heparinization of only the extracorporeal circuit, a blood filter containing immobilized heparinase was developed. This filter degraded 99 percent of heparin's anticoagulant activity within minutes in both canine and human blood.
Looking Back and Moving Forward: Three Tensions in the Teacher Dispositions Discourse

This review chronicles the origins of the use of the term “dispositions” in teacher education and highlights problems in its current definitions and applications, suggesting questions that need to be addressed in dealing with those problems and outlining necessary changes in teacher education programs to address development and assessment of the whole teacher.
Quantification of Color Change Resulting from Pheophytinization and Nonenzymatic Browning Reactions in Thermally Processed Green Peas

The visual green color degradation, as represented by the change of the −a value measured by a tristimulus colorimeter, was found to be caused by not only pheophytinization but also by nonenzymatic browning reactions in green peas at 100, 110, and 120 °C. Mathematical models were developed for predicting the change in the −a value as a function of time and temperature by knowing the kinetic parameters (rate constant and activation energy) of each mechanism. The rate of disappearance of greenness via pheophytinization followed a first-order kinetic model, while the rate of color loss due to nonenzymatic browning reactions followed a zeroth-order kinetic model after an initial lag period. The activation energies for pheophytinization and nonenzymatic browning were 20.4 and 22.3 kcal/mol, respectively. Keywords: Kinetics; visual green color; browning; colorimetry
Synthesis of a peptide with full somatostatin activity.

Abstract A peptide has been synthesized according to the structure proposed for somatostatin by the solid phase method. The synthetic product was assayed and found to possess full somatostatin activity as compared with the natural material.
Studies on Development of Cyanide-resistant Respiration in Potato Tuber Slices.

The respiratory changes which take place in slices of tubers and tuberous roots have long been of interest to plant physiologists. As early as 1887, the wound respiration of white potato tubers was described (3), and since then many of the factors affecting this phenomenon have been analyzed (17). In recent years, the fact that the developed respiration is resistant to cyanide and carbon monoxide has attracted special attention (18, 25). Since the respiration of freshly cut slices can be shown to be mediated by cytochrome oxidase, it has been concluded that there must be some fundamental modification of the respiratory chain during the ageing of these slices. That the cytochrome system does function in aged slices is suggested by the demonstration that their ability to absorb water is inhibited by CO and this effect is reversed by light (15). In addition, the respiratory system shows a high affinity for oxygen (25). These facts pose a number of important questions: a) What electron transport pathway is functional in aged potato slices and in other plant tissues which have a cyanideand CO-resistant respiration? b) How can CO block an energy-requiring process without reducing the net rate of electron transfer ? c) What type of transformation underlies the quantitative and qualitative changes in tissue respiration? The potato tuber slices, in which there is a striking change within one day, seem ideally suited for further investigations on the problem of inhibitorresistant respiration. The plan of the present study has been to compare the respiratory mechanisms in freshly-cut and day-old slices, and to ascertain the conditions necessary for the development of the wound respiration. The work has been carried on at two levels: with tissue slices and with isolated cell fractions. Oxygen uptake has been used as a measure of respiratory activity, and its coupling to phosphorylation estimated by following phosphate uptake. The respiratory components involved in hydrogen and electron transport have been examined by both enzymatic and spectrophotometric techniques. The evidence indicates that during the aerobic incubation of potato slices there is a metabolism-dependent modification of the mitochondrial respiratory chain, probably within the cytochrome system. Preliminary reports on this work have already been published (8, 9, 10, 13).
Part I: Presumptive cone pigments extracted from tropical marine fishes.

Abstract Retinal extracts of a wide variety of diurnal species contained mixtures of a rhodopsin and a more red-sensitive component, also based on retinal. The red-sensitive pigments of more than 30 species were identified with the aid of an iterative corrective procedure. Coryphaena has two visual pigments, one more red-sensitive and the other more blue-sensitive, in addition to its rhodopsin. All three components were identified and their proportions analyzed in each extract. The red-sensitive pigments are not thought to be artifacts or additional rod pigments. Their occurrence in extracts of light-adapted, cone-rich retinae suggests that they are cone pigments. This is supported by the Coryphaena data: the proportion of red-sensitive pigment was greater (1) in light-adapted retinae and (2) in extracts prepared from portions of the retina containing the most cones.
Is morphine dependence mediated exclusively by the Mu receptor

Regional cerebral glucose utilization (RCGU) and behavior during naloxone precipitated withdrawal were studied in rats made dependent on either sufentanil, a highly selective mu opiate agonist, or morphine. Changes in RCGU during withdrawal in 23 of 24 anatomically related limbic and brainstem structures were indistinguishable between rats dependent on morphine or sufentanil. Linear regression analysis indicated that RCGU changes during withdrawal in these two groups were highly correlated (r=0.95). Withdrawal behaviors (autonomic signs of withdrawal, jumps, weight loss, and incidence of diarrhea) were likewise indistinguishable between the two groups. The correlations of both these measurements of dependence suggest that chronic occupation of mu opiate receptors alone is sufficient to produce dependence that is indistinguishable from morphine dependence.
Quasielastic light scattering by flexible polymers in the presence of a sinusoidal driving field: internal relaxation modes

Abstract Application of an applied electric field to a system of charged molecules superimposes a constant drift velocity on the random thermal motions of the molecules. The spectral density of light scattered from this system is frequency shifted by an amount proportional to the electrophoretic mobility of the molecule. Current theories consider only the application of a square-wave field and the effect on the center-of-mass motion of the molecule. A theory is developed in the present communication that considers the effect of a sinusoidal field on the internal motions of random coils. If the applied frequency is greater than ω D =μ EK cos(θ/2), then the center-of-mass motion remains random whereas internal modes may be “driven” by the applied field. Furthermore, the amplitude of the Doppler-shifted peak position diminishes if ωτ m > 1, where τ m is the relaxation time of the m th mode. It is possible, therefore, to obtain precise values for the number of relaxation modes present and their characteristic relaxation times.
Comparison of retention behavior on polymeric resins and an alkyl-bonded silica phase in reversed-phase high-performance liquid chromatography

Abstract The two most obvious differences between alkyl-bonded silica phases and polystyrene-divinylbenzene resins as reversed-phase chromatographic supports are the aromaticity and the lack of hydrogen bonding ability in the polymeric resin. The effect of these differences on the selectivity for a set of small solutes was studied through the use of a solvatochromic comparison method. For retention on a polymeric phase for mobile phases with the modifiers methanol and acetonitrile, the linear solvation energy relationship indicated an increased dependence on the polarizability/dipolarity of solutes. For the modifier tetrahydrofuran, retention on the polystyrene-divinylbenzen resin was indistinguishable from that on the alkyl-bonded silica phase. The hydrogen bonding ability of a solute was found to play a greater role in retention on alkyl-bonded silica than on the polymeric resin for all three modifiers. Since the mobile phase compositions were chosen such that the Hildebrand solubility parameters were equal, the dependence of retention on molar volume was found to be the same for all mobile phase-stationary phase combinations examined.
Hybrid-finite-element analysis of some nonlinear and 3-dimensional problems of engineering fracture mechanics

In this paper, efficient numerical methods for the analysis of crack-closure effects on fatigue-crack-growth-rates, in plane stress situations, and for the solution of stress-intensity factors for arbitrary shaped surface flaws in pressure vessels, are presented. For the former problem, an elastic-plastic finite element procedure valid for the case of finite deformation gradients is developed and crack growth is simulated by the translation of near-crack-tip elements with embedded plastic singularities. For the latter problem, an embedded-elastic-singularity hybrid finite element method, which leads to a direct evaluation of K-factors, is employed.
μ-opioid receptors are present in functionally identified sympathoexcitatory neurons in the rat rostral ventrolateral medulla

Agonists of the μ-opioid receptor (MOR) produce profound hypotension and sympathoinhibition when microinjected into the rostral ventrolateral medulla (RVL). These effects are likely to be mediated by the inhibition of adrenergic and other presympathetic vasomotor neurons located in the RVL. The present ultrastructural studies were designed to determine whether these vasomotor neurons, or their afferents, contain MORs. RVL bulbospinal barosensitive neurons were recorded in anesthetized rats and filled individually with biotinamide by using a juxtacellular labeling method. Biotinamide was visualized by using a peroxidase method and MOR was identified by using immunogold localization of an antipeptide antibody that recognizes the cloned MOR, MOR1. The subcellular relationship of MOR1 to RVL neurons with fast- or slow-conducting spinal axons was examined by electron microscopy. Fast- and slow-conducting cells were not morphologically distinguishable. Immunogold-labeling for MOR1 was found in all RVL bulbospinal barosensitive neurons examined (9 of 9). MOR1 was present in 52% of the dendrites from both types of cells and in approximately half of these dendrites the MOR1 was at nonsynaptic plasmalemmal sites. A smaller portion of biotinamide-labeled dendrites (16%) from both types of cells were contacted by MOR1-containing axons or axon terminals. Together, these results suggest that MOR agonists can directly influence the activity of all types of RVL sympathoexcitatory neurons and that MOR agonists may also influence the activity of afferent inputs to these cells. The heterogenous distribution of MORs within individual RVL neurons indicates that the receptor is selectively targeted to specific pre- and postsynaptic sites. J. Comp. Neurol. 433:34–47, 2001. © 2001 Wiley-Liss, Inc.
Mass transfer with axial diffusion and chemical reaction

Abstract Mass transfer with axial diffusion and chemical reaction is studied for three different cases. The first one is plug flow mass transfer in semi-infinite region. The second one is laminar flow mass transfer in a semi-infinite region. The third one is laminar flow convective diffusion in the region of x ≤ 0 while mass transfer with chemical reaction in the region of x ≥ 0. The first problem is solved in terms of Bessel functions while the second in terms of confluent hypergeometric functions. In order to solve the third problem, orthonormal functions are constructed by linear combination of the eigenfunctions of the two semi-infinite regions respectively. The series expansion coefficients of the solutions are determined by solving a set of forty simultaneous equations obtained through matching boundary conditions at x = 0. Solutions are generally obtained for low Peclet number (Pe = 1, 5, 10) and high reaction rate parameters. Effects of axial diffusion and chemical reaction on the concentration field are discussed.
Binuclear ruthenium macrocycles formed via the weak-link approach.

The "weak-link approach" for the synthesis of metallomacrocycles has been used to synthesize a series of novel Ru(II) macrocycles in high yield. RuCl 2 (PPh 3 ) 3 has been reacted with two different phosphino-alkyl-ether hemilabile ligands, 1,4-(PPh 2 (CH 2 ) 2 O) 2 C 6 H 4 and 1,4-(PPh 2 (CH 2 ) 2 OCH 2 ) 2 C 6 H 4 . The hemilabile bidentate ligand coordinates to Ru(II) centers through both the P and O atoms to form bimetallic "condensed intermediates". The weak Ru-O bonds have been selectively cleaved with CO, 1,2-diaminopropane, and pyridine to yield large open macrocycles. This is the first example of the weak-link approach employed to synthesize macrocycles with Ru, and metal centers in general that have more than four coordination sites.
On the evolution of interacting, magnetized, galactic plasmas

The advent of three-dimensional, electromagnetic, and fully relativistic particle simulations allows a detailed study of a magnetized, rotating plasma, galaxy model. When two such models are simulated, an interaction yielding results resembling observational data from double radio sources, including the emission of synchrotron radiation, are obtained. Simulation derived morphologies, radiation intensities, frequency spectra, and isophote patterns are directly compared to observations. The constituent plasma parameters associated with the source Cygnus A are found to ben e =1.8×10−3 cm−3,T=2.8 keV,B=20–30 gamma, with a small population of electrons accelerated to GeV energies by a rotation induced electric field. The results of these simulations, involving a computational resource of five CDC 7600 and five Cray-1 computers, strongly supports an inhomogeneous version of the Klein world model.
Factor analysis of the cognitive-somatic anxiety questionnaire

The Cognitive-Somatic Anxiety Questionnaire (CSAQ; Schwartz, Davidson, & Goleman, 1978) is a brief self-report rating scale designed to differentiate between cognitive and somatic symptoms of anxiety. The CSAQ gained relatively widespread acceptance as a behavioral assessment instrument before much was known about its psychometric properties. Psychometric studies of the CSAQ (e.g., DeGood & Tait, 1987) have raised questions about the instrument's item content and subscale structure. The primary purpose of the present study was to determine whether the Cognitive and Somatic subscales correspond to the instrument's factorial structure in a clinically anxious population. The sample consisted of 120 nonpsychotic psychiatric inpatients. Factor analysis with oblique rotation accounted for 60% of the total variance and yielded four factors that do not conform to the Cognitive-Somatic subscale structure. The results challenge the validity of the CSAQ and suggest the need for an improved instrument capable of differentiating the multidimensional features of clinical anxiety.
Radioimmunoassay of the major group specific protein of endogenous baboon type C viruses: relation to the RD-114-CCC group and detection of antigen in normal baboon tissues.

Abstract The major group specific (gs) protein of the endogenous baboon type C virus M7 was purified to homogeneity by gel filtration and isoelectric focusing. The protein has a molecular weight of approximately 33,000, as determined by electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate, and an isoelectric point (pI) of 7.1, different from the pIs of similarly purified gs proteins from six other mammalian type C viruses. Detergent disrupted M7 virus, whether grown in canine thymus or human rhabdomyosarcoma cells, fully displaced radiolabeled M7 gs protein from antigen-antibody complexes in a competitive radioimmunoassay. No antigenic differences were detected among the gs proteins of five independent isolates of baboon type C viruses grown in various cultured cell lines. The gs proteins of six independently isolated feline viruses of the RD-114/CCC group were antigenically related to, but could be distinguished from, the gs proteins of baboon type C viruses. No significant cross-reactions were observed in the radioimmunoassay for M7 gs protein using several other type C viruses, including two previously isolated from a woolly monkey and a gibbon ape. Group specific antigen was found in normal baboon testicular and splenic tissues using the M7 radioimmunoassay; no gs antigen could be detected in these same tissues using a radioimmunoassay for the gs protein of the woolly monkey type C virus. No gs antigen was found in baboon liver or in the tissues of several other primates.
Living in a physical world III. Getting up to speed

Generalizations in biology come hard, so we treasure any that cut through life’s overwhelming diversity. In his famous essay, “On Being the Right Size,” J B S Haldane (1926) notes that jumping animals of whatever size should reach the same maximum height; Haldane attributes the insight to Galileo. Other iconic figures make the same assertion— Giovanni Alphonso Borelli (1680), grandfather of biomechanics; D’Arcy Thompson (1942), godfather of biomechanics; and then A V Hill (1938), father-figure for muscle physiologists. The basic reasoning is straightforward. The force of a muscle varies with its cross-sectional area. The distance a muscle can shorten varies with its length. So the work a muscle can do will vary with the product of the two, in effect with its mass. All mammals have about the same mass of muscle relative to mass, about 45%, and other jumping animals differ only a little more. Thus the work available for a jump should be proportional to body mass. At the same time, the energy, mgh, required to achieve a given height, h, should also be proportional to body mass, m (gravitational acceleration, g, of course, stays constant). Put in slightly different terms, launch speed, vo, sets height for a projectile shot upward, and kinetic energy at launch is /2 mv 2 0 . So the energy required to achieve a given launch velocity, like the work available, will be proportional to body mass. Either way, height should not depend on body mass. As Borelli (1680), in the first great treatise on biomechanics, put it “...if the weight and mass of a dog is a fiftieth of those of a horse [ ] the motive force of the dog would be a fiftieth of that of the horse. Therefore, if the other conditions are equal [ ], the dog will jump as far as the horse.” (‘Force’ for Borelli meant something close to what we recognize as work or energy.) The last essay (Vogel 2005) focused on the behaviour of ballistic projectiles after launch. This one fleshes out the story by looking at what happens prior to launch, how projectiles of diverse sizes and functions reach their similar launch speeds.
Effect of microstructural uncertainty on the yield stress of nanocrystalline nickel

Abstract Numerical simulations can be exploited to understand the sensitivity of the mechanical properties of materials to microstructural variability and hence improve their mechanical performance and reliability. We investigate the effect of the initial microstructure of nanocrystalline (nc) nickel, i.e. grain size, grain size distribution and initial dislocation density, on the yield stress through numerical simulations using a phase field dislocation dynamics model. Our work reveals that the grain size distribution has a significant influence on the yield stress for grain sizes under 32 nm and that the initial dislocation density is of key importance in determining the yield stress. Simulations with a zero initial dislocation density exhibit an almost size-independent stress–strain behavior, while Hall–Petch effect was observed in simulations with non-zero initial dislocation density. Using the results of our simulations we construct response surface functions of the yield stress that can be propagated to obtain a probability density function of the yield stress as a function of microstructure variables. We observe that the effect of uncertainty in grain size distribution and initial dislocation density is stronger for smaller grain sizes.
Molecular Imprinting of Carboxylic Acids Employing Novel Functional Macroporous Polymers.

Imprinted network polymers incorporating basic functional groups were developed to assess the binding and specificity of carboxylic acids. The binding affinities were determined using t-BOC-phenylalanine and 2-phenylbutyric acid as templates and substrates. Chiral selectivity for the enantiomers of t-BOC-phenylalanine was found for polymers incorporating adenine or 2-aminopyridine functionality. Chiral selectivity in the case of (R)-(−)-2-phenylbutyric acid was found for the polymer utilizing N-(2-aminoethyl) methacrylamide as the functional monomer. Optimization of binding was achieved by changing polymerization conditions (thermal versus photochemical polymerization, monomer:template ratio) for t-BOC-phenylalanine imprinted polymers employing the N-(2-aminopyridine) methacrylamide monomer.
Lymph node evaluation is associated with improved survival after surgery for early stage gallbladder cancer.

gallbladder (GB) cancer. We sought to determine the survival benefit conferred by adequate LN evaluation. Methods. We used the surveillance, epidemiology and end results (SEER) neoplasm registry to identify patients who had an operation for GB cancer between 1988 and 2004. Patients were classified by stage of disease, operative procedure performed (cholecystectomy alone or radical resection), number of LNs evaluated (0, 1, >1), and receipt of radiation (RT). We included patients with T1B, T2, and T3 neoplasms who were LN positive or negative. Patients with T4 neoplasms and those with metastatic disease were excluded. Multivariate analysis included adjustment for age, race, sex, neoplasm grade, stage, operation performed, receipt of RT, and neoplasm registry. Results. We identified 4,614 patients who underwent operative treatment for stage 1--2B GB (including T1B--T3 and LN positive or negative) cancer between 1988 and 2004. Of 4,614 patients, 9.6% (442) had radical resection, whereas 90.4% (4,172) had cholecystectomy alone. Among patients undergoing radical resection, 56% had LNs evaluated as compared with 28% of patients after cholecystectomy. For patients with T1BandT2neoplasmswhounderwentradicalresection,pathologicevaluationofatleast1LNwasassociated with a significant improvement in median overall survival (OS) compared with those who had no LN evaluated(123 months vs 22 months;P 1)didnotprovideanyadditionalbenefitcomparedwith the evaluation of a singlenode (HR = 0.795; 95% CI= 0.571, 1.107). Radical resection alone(withoutLN evaluation) did not provide any benefit over cholecystectomy alone (HR = 1.098; 95% CI = 0.971, 1.241). Conclusion. LN evaluation is a critical component of radical resection for GB cancer. In the absence of LN evaluation, radical resection provides no benefit over cholecystectomy alone. (Surgery 2009;146:706-13.)
Compositionally controlled rhombohedral to cubic phase transition in CsTe2−xWxO6 related to pyrochlore structure

Abstract CsTe 2 O 6 adopts a rhombohedrally distorted pyrochlore related structure due to the 1:3 ordering of Te 4+ and Te 6+ in the octahedral sites respectively. Phases of the type CsTe 2− x W x O 6 were found to have the cubic pyrochlore structure from x = 0.2 to 0.5. These phases all contain Te 4+ and Te 6+ (mixed with W 6+ ) and are disordered in octahedral sites of the pyrochlore structure. This mixed valence situation results in strong optical absorption in the visible region of the spectrum but does not produce a measurable electrical conductivity.