cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism of Colicin Action: Early Events

The kinetics and the temperature dependence of potassium loss from Escherichia coli cells treated with colicin K have been examined. At 37 C, after a single lethal hit, essentially all of the intracellular potassium is lost within the first few minutes of treatment. The initial rate of loss is linearly related to colicin concentration up to a multiplicity of 30. As the temperature is decreased over the range from 37 to 1 C, an increasing delay is seen in the initiation of potassium loss after colicin adsorption. This delay can be overcome by increasing colicin multiplicity and probably reflects an alteration of the cell membrane at these temperatures. A comparison of this effect with an apparently related effect of temperature on the action of irehdiamine A indicates that the delay may represent the inhibition of a transmission process occurring in the membrane.
The dividing streamline of bifurcating flows in a two-dimensional channel at low Reynolds number

Abstract The low Reynolds number bifurcation flow with arbitrary bifurcation ratios in an infinitely long two-dimensional channel, which is divided into two equal channels by a semi-infinite plate, is analyzed based on the Stokes approximation. The solution of the problem is obtained by superimposing two fundamental solutions: one representing the equi-bifurcation flow and another representing the U-turn flow. The distributions of the velocity and the mean pressure computed from a truncated version of the series solution are presented for both of the fundamental flows. The geometry of the dividing streamline is also presented for a number of different bifucation ratios. The perturbation of the flow created by the flow bifurcation reaches an upstream distance from the bifurcation point approximately equal to the half width of the channel and a downstream distance of the quarter width of the channel in the equi-bifurcation flow. In the U-turn flow, the flow perturbation is limited to a distance approximately equal to the width of the channel in the undivided portion of the channel and a distance of the quarter width of the channel in the divided portion of the channel. In both of the fundamental flows, the major portion of the transition from the upstream flow to the downstream flow takes place in a region immediately upstream to the bifurcation point.
Solution structure of the loops of bacteriorhodopsin closely resembles the crystal structure

Bacteriorhodopsin is one of very few transmembrane proteins for which high resolution structures have been solved. The structure shows a bundle of seven helices connected by six turns. Some turns in proteins are stabilized by short range interactions and can behave as small domains. These observations suggest that peptides containing the sequence of the turns in a membrane protein such as bacteriorhodopsin may form stable turn structures in solution. To test this hypothesis, we determined the solution structure of three peptides each containing the sequence of one of the turns in bacteriorhodopsin. The solution structures of the peptides closely resemble the structures of the corresponding turns in the high resolution structures of the intact protein.
Estrogen regulates the number of RNA polymerase II molecules in rooster liver

Administration of estrogen to roosters causes an increase in the activities of DNA-dependent RNA polymerases I and II in nuclei isolated from liver. In an effort to determine the cause of this increased transcriptional activity, we have examined the activity of RNA polymerase II that we have solubilized from nuclei of normal, estrogen-stimulated, and estrogen-withdrawn roosters. In addition, we have measured the actual numbers of RNA polymerase II molecules per nuclear equivalent of DNA in livers of roosters in each estrogenic state by the technique of [3H]amanitin-binding. The administration of estrogen is attended by a 2-fold increase in enzymatic activity of solubilized RNA polymerase II per liver nucleus within 24 h. In addition, there is a 2-fold increase in the number of RNA polymerase II molecules per nucleus in the livers of these animals after the administration of estrogen. During withdrawal from estrogen for 14 days, the activities of RNA polymerases I and II in isolated nuclei and the activity of solubilized RNA polymerase II return to the unstimulated levels. Moreover, the [3H]amanitin-binding capacity of nuclear extracts from the livers of roosters in various stages of hormonal stimulation closely mimics the RNA polymerase II activity of the same extracts. These observations indicate that estrogen exerts a rigid control over the population of RNA polymerase II molecules in avian liver.
Drifting plasma magneto-ionic theory for oblique incidence

The magneto-ionic theory for drifting plasma for the case of oblique incidence is developed by using matrix analysis. The q variable may be evaluated from a determinantal equation. The present theory reduces, in particular cases, to the Booker quartic and to the magneto-ionic theory for drifting plasma developed previously by the author.
Chromosome segregation in crane-fly spermatocytes: cold treatment and cold recovery induce anaphase lag

Anaphase lagging of autosomes was observed in 6.1±5.4% of the primary spermatocytes in untreated larvae of the crane fly, Nephrotoma suturalis. Lagging was induced by exposure of larvae to 6 ° C and during recovery at 22 ° C from exposure to 0.2, 2, and 6 ° C. The incidence of anaphase lag was maximal at 80 to 90 min of recovery. Induced lagging was observed at that recovery time after exposures of only 2.5 h to 2 or 0.2 ° C, but its incidence increased with longer exposures. As many as 85% of the cells in anaphase contained autosomal laggards after 61 h at 2 ° C and 80 to 90 min of recovery. At 2 ° C, cells reached the prophase-prometaphase transition, but spindles did not appear to form. Those cells proceeded through prometaphase during recovery, reaching mid-anaphase after 80 to 90 min of recovery. Chromosomes that lagged at anaphase during recovery from 2 ° C were observed in living cells to be half-bivalents derived from bivalents that congressed to the metaphase plate. One or both half-bivalents of any bivalent could lag. In some cells, one half-spindle had more half-bivalents than the other. Cells with autosomal laggards often did not cleave, and in uncleaved cells the second division employed spindles having two, three, or four poles. The basis of induced lagging might be a lapse in spindle attachment or motive force application at the start of anaphase or a failure of chromosomes to achieve proper orientation before the onset of anaphase.
Free radical solution copolymerization of glycidyl methacrylate with n‐vinyl pyrrolidinone

Copolymers of glycidyl methacrylate (monomer 1) with N-vinyl pyrrolidinone (monomer 2) were prepared at 70°C in low yield by free radical initiated solution polymerizations in ethyl acetate, 1,4-dioxane and mixtures of the two solvents. Copolymer compositions were determined by proton nuclear magnetic resonance spectroscopy. Monomer reactivity ratios were then derived using the method of Kelen & Tudos. The magnitude of r1 was relatively unaffected by solvent composition, and ranged from 4.32 to 4.53 in a random fashion. In contrast, values of r2 showed a greater relative (but still random) spread from 0.0075 to 0.0147. Copolymers prepared by batch polymerization are selectively enriched with GMA monomer.
Carbohydrate and Protein Content of Boron-Deficient Tomato Root Tips in Relation to Anatomy and Growth

Probably the earliest measurable response of plants to boron deficiency is restriction in elongation of root tips of plants transferred to solutions lacking boron (1, 5, 7, 13). Necrosis of the root tip is also soon evident, followed by the emergence of short, stubby laterals close to the tip (1, 11, 12). Why the growth of roots stops when boron is lacking is not known. Indeed, of the many physiological roles that have been suggested for boron (3, 10), no one has yet been established by rigorous proof. Skok (10) suggested that maturation and differentiation of cells is a function of available boron. Gauch and Dugger (2) advanced the hypothesis that boron is necessary for the translocation of sugar in plants. They further reasoned (2) that failure of cells to develop normally in root tips or stem tips when boron is deficient results from failure of sugars to move to meristematic areas when boron is lacking. Our experiments were planned to test the possible relationship of boron deficiency to sugar transport and to growth at apical meristems by making analyses of root tips of tomato plants grown in solution cultures at different boron levels and correlating these results with the anatomy of the root tip. By shading some of the plants to reduce synthesis of carbohydrates in the leaves, the effect of some deficiency in carbohydrates on growth and composition of the roots could be observed with boron present or absent. A number of experiments gave essentially the same results as the one reported here.
Taylor stability of viscous fluids with application to film boiling

The dispersion relation is evaluated numerically for Taylor waves in a viscous unstable interface with surface tension. The solution takes account of transverse curvature and the numerical evaluations apply to horizontal cylindrical, as well as to plane, interfaces. The result is verified with frequency and wavelength data obtained during film boiling on horizontal wires. A very general empirical correlation is given, en passant, for the vapor blanket thickness during film boiling.
Bayesian Multidimensional IRT Models With a Hierarchical Structure

As item response models gain increased popularity in large-scale educational and measurement testing situations, many studies have been conducted on the development and applications of unidimensional and multidimensional models. Recently, attention has been paid to IRT-based models with an overall ability dimension underlying several ability dimensions specific for individual test items, where the focus is mainly on models with dichotomous latent traits. The purpose of this study is to propose such models with continuous latent traits under the Bayesian framework. The proposed models are further compared with the conventional IRT models using Bayesian model choice techniques. The results from simulation studies as well as actual data suggest that (a) such models can be developed; (b) compared with the unidimensional IRT model, the proposed models better describe the actual data; and (c) the use of the proposed IRT models and the multiunidimensional model should be based on different beliefs about the unde...
Rates of Best Uniform Rational Approximation of Analytic Functions by Ray Sequences of Rational Functions

In this paper, problems related to the approximation of a holomorphic function f on a compact subset E of the complex plane C by rational functions from the class $ {\cal R}_{n,m} $ of all rational functions of order (n,m) are considered. Let ρ n,m = ρ n,m (f;E) be the distance of f in the uniform metric on E from the class $ {\cal R}_{n,m} $ . We obtain results characterizing the rate of convergence to zero of the sequence of the best rational approximation { ρ n,m(n) } n=0 ∞ , m(n)/n → θ ∈ (0,1] as n → ∞ . In particular, we give an upper estimate for the liminf n →∞ ρ n,m(n) 1/(n+m(n)) in terms of the solution to a certain minimum energy problem with respect to the logarithmic potential. The proofs of the results obtained are based on the methods of the theory of Hankel operators.
Current sensitivity of plasma voltage and emission line intensities in a planar magnetron glow discharge device

A coaxial arrangement of a ring-shaped ceramic magnet and a disk-shaped rare-earth magnet is used to trap plasma electrons in circular orbits near the surface of the planar cathode. This configuration results in the formation of a ring-shaped plasma which is stable at all pressures in the range 0.0007 Torr to over 10 Torr. A model is presented which describes the sensitivities of plasma emission intensities to the discharge current for atoms and ions of both the plasma gas and the sputtered flux of cathodic material. The model is based on the number of electron collisions needed to generate the radiating species. Experimental data for the species Ar, Ar+, Cu, and Cu+ are compared to the model.
The Irony in—and of—Journalism: A Case Study in the Moral Language of Liberal Democracy

In Contingency, Irony, and Solidarity, Rorty argues that liberal democracy has had “the last conceptual revolution it needs.” He also suggests that journalism, like literature, helps realize the benefits of this revolution by telling stories about suffering and injustice—stories that contribute to a sense of human solidarity. This essay examines a particular rhetorical and narrative strategy-irony-used in a particular genre of contemporary journalism—investigative reporting—to tell such stories. It argues that irony in journalism presents several ironies of journalism. One is that irony transfigures the conventions of objectivity so that the very textual devices intended to assure the differentiation of fact and value become the means to express their fundamental unity. Another, darker irony of journalism concerns the possibility that investigative journalism, as an exercise in the moral language of liberal democracy, may yet contribute to its own undoing.
Analysis of sub-wavelength sized OPC features

Abstract Rigorous 3-D electromagnetic analysis is used to examine the actual near field characteristics and assess the resulting effects on imaging of light passing through serifs and hammer head line-ends in optical proximity correction (OPC) of photomasks. The simulation is carried out using the finite-difference time-domain simulator TEMPEST using up to 5 million nodes and 150M of memory. OPC features which are contiguous and share sides with open features transmit very effectively, whereas OPC features which are isolated by chrome stringers or are cut-off by nearly touching chrome corners are much less effective and require rigorous electromagnetic analysis.
The `tabloid effect' in the O.J. Simpson case The National Enquirer and the production of crime knowledge

• This article considers the `tabloid effect' of the O.J. Simpson case in terms of the production of crime knowledge. Summarizing important literature on crime and the media, it suggests that unusual circumstances must occur for news media to offer information in conflict with law enforcement agencies (as in the Rodney King incident, where an independent videotape existed). The Simpson case is an excellent example of how the debate on criticism of the blurring of the distinction between `mainstream' and `tabloid' media helps to illustrate the economic and cultural mechanisms that produce crime knowledge. This is done through careful discussion of two crucial `mainstream' assessments of the notorious `tabloid' weekly the National Enquirer. •
Electronic-structure study of an edge dislocation in Aluminum and the role of macroscopic deformations on its energetics

Abstract We employed a real-space formulation of orbital-free density functional theory using finite-element basis to study the defect-core and energetics of an edge dislocation in Aluminum. Our study shows that the core-size of a perfect edge dislocation is around ten times the magnitude of the Burgers vector. This finding is contrary to the widely accepted notion that continuum descriptions of dislocation energetics are accurate beyond ∼1–3 Burgers vector from the dislocation line. Consistent with prior electronic-structure studies, we find that the perfect edge dislocation dissociates into two Shockley partials with a partial separation distance of 12.8 A. Interestingly, our study revealed a significant influence of macroscopic deformations on the core-energy of Shockley partials. We show that this dependence of the core-energy on macroscopic deformations results in an additional force on dislocations, beyond the Peach–Koehler force, that is proportional to strain gradients. Further, we demonstrate that this force from core-effects can be significant and can play an important role in governing the dislocation behavior in regions of inhomogeneous deformations.
Relax or study? A qualitative user study on the usage of live mobile TV and mobile video

The usage of live mobile TV and mobile video devices is increasing in Japan as well as in other countries. In the summer of 2007, in the Tokyo area, we conducted a user study by means of qualitative interviews with 11 participants in order to understand when, how, and why people use such devices. In contrast to previous work, our user study compared the usage of live mobile TV with that of mobile video. In this article, our findings reveal a sharp contrast in (1) the usage of live mobile TV and mobile video on commuter buses or trains, at home, and for sharing experiences; and (2) the interest that live mobile TV users have in mobile video, and vice versa. In this article we present (1) findings that reveal the different attitudes concerning usage of live mobile TV compared with that of mobile video; and (2) hypotheses on user motivations, intentions, and desires derived from the observed attitudes.
Electrical properties affecting discharge of units of the mid and posterolateral thalamus of conscious cats.

Discharge properties in response to intracellularly applied, rectangular currents were measured in units of the mid (lateralis dorsalis and centrolateral nuclei) and posterolateral (lateralis posterior and pulvinar nuclei) thalamus of conscious cats. A separate aim was to determine if neuronal excitability changed in association with changes in stimulus-evoked activity after the animals were trained to discriminate between two acoustic stimuli when performing a conditioned motor response. Low threshold spike (l.t.s.) discharges were observed in three of 272 cells given 1 nA intracellular, hyperpolarizing current pulses of 40 ms duration. This finding supports the view that thalamic neurons of conscious animals operate mainly in the relay as opposed to the oscillatory mode. Application of larger and longer hyperpolarizing currents in the cells produced rebound l.t.s. discharges, supporting the expectation that most thalamic neurons are capable of producing this type of discharge. Decrements of spike afterhyperpolarizations (AHP) and broadening of spike bases upon repeated discharge also were observed in each area of the thalamus studied. After conditioning, changes were found in the posterolateral thalamus (but not in the mid-thalamus) in the proportions of cells with spontaneous, rapid (>/=50 Hz), repetitive, discharges (RRD) and rapid, sustained discharges at rates >/=100 Hz during application of depolarizing current (RSD). In the posterolateral thalamus the percentage of units responding to 1 nA depolarization with RSD fell from 71% before conditioning to 45% after conditioning. The percentage of cells with RRD decreased from 69% to 46%. The changes were accompanied by a 3 mV hyperpolarization of the membrane potentials of the cells and a decrease in baseline activity. After conditioning, increases in excitability were found in cells of the mid thalamus that responded selectively to the click conditioned stimulus (CS) that elicited the conditioned response, and decreases in excitability were found in cells of the posterolateral thalamus that responded to the discriminative acoustic stimulus (DS) to which the animals were trained not to respond. An earlier study showed a potentiation of discharge in response to the CS in units of the midthalamus after similar conditioning and a reduction of the proportion of DS responsive units and peak discharge to the DS in units of the posterolateral thalamus. We conclude that the discharge properties of units of the mid and posterolateral thalamus can change to support discrimination between acoustic stimuli of different functional significance after conditioning.
Phagocytosis of spermatozoa by the rabbit vagina

Twenty-four hours after mating in the rabbit, numerous spermatozoa are observed attached to the surgace of the vaginal epithelium. Spermatozoa appear to be attached by their heads to microvilli of the simple columnar cells which compose the vaginal epithelium. Spermatozoa are taken up by the epithelial cells, and they are found within the cells in various stages of degeneration up to seven days after mating. Epithelial cells frequently appear to be filled with numerous vacuoles containing sperm components in various stages of degeneration. It is suggested that some property of the surface of sperm heads may render them particularly susceptible to phagocytosis. Phagocytosis of spermatozoa may not have long-term harmful effects for the epithelium since these epithelial cells presumably have a high rate of turnover.
Semianalytical Models for the Formation of Disk Galaxies. I. Constraints from the Tully-Fisher Relation

We present new semianalytical models for the formation of disk galaxies with the purpose of investigating the origin of the near-infrared Tully-Fisher (TF) relation. The models assume that disks are formed by cooling of the baryons inside dark halos with realistic density profiles and that the baryons conserve their specific angular momentum. Adiabatic contraction of the dark halo is taken into account, as well as a recipe for bulge formation based on a self-regulating mechanism that ensures disks to be stable. Only gas with densities above the critical density given by Toomre's stability criterion is considered eligible for star formation. A Schmidt law is assumed to prescribe the rate at which this gas is transformed into stars. The introduction of the star formation threshold density proves an essential ingredient of our models and yields gas mass fractions that are in excellent agreement with observations. Finally, a simple recipe for supernovae feedback is included. We emphasize the importance of extracting the proper luminosity and velocity measures from the models, something that has often been ignored in the past. We use the zero point of the K-band TF relation to place stringent constraints on cosmological parameters. In particular, we rule out a standard cold dark matter universe, in which disk galaxies are too faint to be consistent with observations. The TF zero point, in combination with nucleosynthesis constraints on the baryon density, and with constraints on the normalization of the power spectrum, requires a matter density Ω0 0.3. The observed K-band TF relation has a slope that is steeper than simple predictions based on dynamical arguments suggest. Taking the stability related star formation threshold densities into account steepens the TF relation and decreases its scatter. However, in order for the slope to be as steep as observed, further physics are required. We argue that the characteristics of the observed near-infrared TF relation do not reflect systematic variations in stellar populations, or cosmological initial conditions. In fact, feedback seems an essential ingredient in order to explain the observed slope of the K-band TF relation. Finally, we show that our models provide a natural explanation for the small amount of scatter that makes the TF relation useful as a cosmological distance indicator.
Temperament, Peer Victimization, and Nurturing Parenting in Child Anxiety: A Moderated Mediation Model

Research has linked fearful temperament and childhood anxiety. Yet there remain numerous factors that moderate and mediate this relation. Two specific factors, identified in separate lines of research, are peer victimization and parenting. The current study tested a moderated mediational model to investigate the respective effects of peer victimization and nurturing parenting on the relation between fearful temperament and child anxiety. Participants were 124 parent–child dyads recruited from the community. Children were between the ages of 7 and 12 (56.5 % male, 93.5 % Caucasian) and most parents were mothers. Overall the data fit the model well. Analyses indicated that peer victimization was a mediator of the temperament to child anxiety relation, while nurturing parenting moderated this mediated effect. Nurturing parenting did not mediate the temperament to child anxiety relation directly. The findings suggest that nurturing parenting may be a specific, rather than global, protective factor for peer victimization in child anxiety.
The transition between ductile and slow-crack-growth failure in polyethylene

Abstract In the neighbourhood of room temperature, linear polyethylene will exhibit two types of long-time failure under a constant stress: (a) ductile failure, which is produced by a creep process, and (b) brittle fracture, which is produced by slow crack growth. The kinetics of each failure process have been quantitatively represented based on experimental data. The transition time from one failure mechanism to the other has been calculated in terms of the material parameters relevant to each failure mechanism and the defect responsible for crack growth.
The ontological proof revisited

“I began to ask myself whether there might be found a single argument which would require no other for its proof than itself alone, and would suffice to demonstrate that God truly exists.” —St. Anselm
Incidentalomas--clinical correlation and translational science required.

How many times each day does an incidental finding lead to other tests, additional inconclusive results, and still further testing? Dr. John Stone writes that with a growing number of “incidentalomas,” what to tell the patient remains unclear.
Robust semiparametric M-estimation and the weighted bootstrap

M-estimation is a widely used technique for statistical inference. In this paper, we study properties of ordinary and weighted M-estimators for semiparametric models, especially when there exist parameters that cannot be estimated at the n convergence rate. Results on consistency, rates of convergence for all parameters, and n consistency and asymptotic normality for the Euclidean parameters are provided. These results, together with a generic paradigm for studying semiparametric M-estimators, provide a valuable extension to previous related research on semiparametric maximum-likelihood estimators (MLEs). Although penalized M-estimation does not in general fit in the framework we discuss here, it is shown for a great variety of models that many of the forgoing results still hold, including the n consistency and asymptotic normality of the Euclidean parameters. For semiparametric M-estimators that are not likelihood based, general inference procedures for the Euclidean parameters have not previously been developed. We demonstrate that our paradigm leads naturally to verification of the validity of the weighted bootstrap in this setting. For illustration, several examples are investigated in detail. The new M-estimation framework and accompanying weighted bootstrap technique shed light on a universal way of investigating semiparametric models.
Droplet-driven transports on superhydrophobic-patterned surface microfluidics

Droplet-based transport phenomena driven by surface tension have been explored as an automated pumping source for a number of chemical and biological applications. In this paper, we present a comprehensive theoretical and experimental investigation of unconventional droplet-based motions on a superhydrophobic-patterned surface microfluidic (S(2)M) platform. The S(2)M surfaces are monolithically fabricated using a facile two-step laser micromachining technique on regular polydimethylsiloxane (PDMS) chemistry. Unlike the traditional droplet-driven pumps built on an enclosed microfluidic network, the S(2)M network pins the liquid-solid interface of droplets to the lithographically defined wetting boundary and establishes a direct linkage between the volumetric and hydraulic measures. Moreover, diverse modes of droplet motions are theoretically determined and experimentally characterized in a bi-droplet configuration, among which several unconventional droplet-driven transport phenomena are first demonstrated. These include big-to-small droplet merging, droplet balancing, as well as bidirectional transporting, in addition to the classic small-to-big droplet transition. Furthermore, multi-stage programmable bidirectional pumping has been implemented on the S(2)M platform, according to the newly established droplet manipulation principle, to illustrate its potential use for automated biomicrofluidic and point-of-care diagnostic applications.
Appropriate therapeutic selection for patients with shift work disorder

Abstract Background Shift work disorder (SWD) is characterized by symptoms of excessive sleepiness during work hours or insomnia during allotted daytime sleep hours, as well as by a disruption of the circadian rhythm. Many shift workers with SWD experience significant social, behavioral, and health problems as a result of this disorder. SWD is associated with a higher risk of occupational and motor vehicle accidents, and thus poses a public health risk. Methods Currently there are both pharmacologic and non-pharmacologic treatments for this disorder that can be used to normalize the disruption of the circadian cycle or alleviate the symptoms of excessive sleepiness or insomnia. The American Academy of Sleep Medicine and the British Society of Psychopharmacology have developed guidelines for the diagnosis and treatment of patients with SWD. Results Recommended therapies for altering the circadian cycle include chronobiotics such as melatonin or melatonin agonists and non-pharmacologic interventions such as timed light exposure. Other therapies, such as sedative hypnotics, target daytime insomnia, while pharmacologic agents such as modafinil, armodafinil, and caffeine and non-pharmacologic approaches such as napping promote nighttime alertness. Conclusions While no therapies (pharmacological or nonpharmacological) can restore altered circadian cycles to baseline levels, proper identification and management of SWD will likely reduce its co-morbidities and improve the quality of life for individuals with this disorder.
Historical returns and the appropriate time-frame for future value calculations: Implications for risk management and personal financial planning

In future value calculations, investors often assume that the real return is constant over the planning horizon. We examine whether this assumption is appropriate. Our results suggest that investors can expect to earn the historical average real return provided their horizon is at least 15 years for stocks and at least 7 years for bonds, depending on the size of recent shocks. This “rule of thumb” assures reasonable insulation from the inevitable fluctuations of the market.
Matrix Operator, W(M1,M2,M3), and Schultz-Type Indices

Recently proposed matrix operator, W(M1,M2,M3), is used to generate the molecular topological index, MTI, and novel Schultz-type descriptors. Matrix algebra involved by this operator is exemplified and discussed in comparison to the Cramer algebra.
Expectations of obese trainees: how stigmatized trainee characteristics influence training effectiveness

This study identifies stigma as a potential precursor to self-fulfilling prophecies in training interactions. Expectations held by leaders often result in actions that elicit expectancy-confirming behaviors from their subordinates. The results of the present study suggest that trainee weight (manipulated with a photograph depicting the trainee as either obese or average weight for height) influenced female trainer expectations and evaluations of the training and trainee. Furthermore, the results suggest that negative expectations held by trainers were related to trainee evaluations of the training and the trainer and, for less flexible trainers, to decrements in trainee performance on the trained task. Overall, the results suggest that trainer expectations can be influenced by stereotypes held about trainee characteristics, thus undermining training effectiveness.
Synthesis and Characterization of Branched Gold Nanoparticles

In this work we present the synthesis of branched gold nanoparticles based on the seed mediated growth technique. The materials have been characterized by advanced electron microscopy techniques in order to elucidate morphology, size and internal structure.
Assay of enzymes involved in cytokinin metabolism by means of reversed-phase high-performance liquid chromatography

Abstract Assay of enzymes involved in cytokinin metabolism can be rapidly and conveniently carried out by using reversed-phase high-performance liquid chromatography (HPLC) to quantitate either the formation of product or the loss of substrate. The initial rates of loss of added 6-(3-methylbut-2-enylamino)purine or 6-benzylaminopurine can be determined in a variety of plant tissues. Asay of nucleosidase activity with 6-(3-methylbut-2-enylamino)-9-β- d -ribofuranosylpurine, 6-(4-hydroxy-3-methylbut-2-enylamino)-9-β- d -ribofuranosylpurine or adenosine as substrates can be accomplished by quantitating the loss of riboside or the formation of 8-OH cytokinins can be readily accomplished and the subsequent formation of 2,8-diOH cytokinin can be measured simultaneously if dual-wavelength monitoring is used. HPLC with a variety of solvent systems facilitates the assay of very small quantities of enzymes and the detection of multiple products.
Effectiveness and Longevity of Phosphorus Inactivation with Alum

ABSTRACT Effectiveness and longevity of alum treatments were evaluated in 21 lakes (or lake basins) across the United States; 9 were polymictic and 12 were dimictic. Effectiveness was judged from reductions in lake TP (total phosphorus) and internal loading rate, as well as chlorophyll a (chl a), both initially and over periods ranging from 4 to 20 years following treatment. Internal loading rate was reduced in six of nine polymictic lakes/basins by an average of two-thirds, and lake TP was reduced by about one-half, which persisted for 5–11 years. Internal loading rate in dimictic lakes (7 of 7 with adequate data) remained reduced by an average of 80% for 4 to 21 years (average 13 yrs). For the six polymictic lakes, in which treatment was effective, chl a decreased by an average of two-thirds initially, but was about 40% less than die pre-treatment level after 5 to 11 years. Chl a decreased in seven dimictic lakes by an average of 57% initially and 42% after 5–18 years. In some cases, response was indepe...
Induced pluripotent stem cell-derived neural stem cell therapies for spinal cord injury

The greatest challenge to successful treatment of spinal cord injury is the limited regenerative capacity of the central nervous system and its inability to replace lost neurons and severed axons following injury. Neural stem cell grafts derived from fetal central nervous system tissue or embryonic stem cells have shown therapeutic promise by differentiation into neurons and glia that have the potential to form functional neuronal relays across injured spinal cord segments. However, implementation of fetal-derived or embryonic stem cell-derived neural stem cell therapies for patients with spinal cord injury raises ethical concerns. Induced pluripotent stem cells can be generated from adult somatic cells and differentiated into neural stem cells suitable for therapeutic use, thereby providing an ethical source of implantable cells that can be made in an autologous fashion to avoid problems of immune rejection. This review discusses the therapeutic potential of human induced pluripotent stem cell-derived neural stem cell transplantation for treatment of spinal cord injury, as well as addressing potential mechanisms, future perspectives and challenges.
Direct titration of potassium ferricyanide with hydrazine sulphate in presence of zinc sulphate determination of hydrazine

Abstract Operative conditions for direct titration of potassium ferricyanide solution with a solution of hydrazine sulphate which contains zinc sulphate are described. The results are comparable with those obtained by the standard iodate procedure. The chief advantages of the present method of estimating hydrazine are (1) titration in slightly acidic medium and (2) no indicator is required. Determination of substituted hydrazines, hydroxylamine and other reducing substances on similar lines is suggested.
Polycyclic aromatic and aliphatic hydrocarbons in Chukchi Sea biota and sediments and their toxicological response in the Arctic cod, Boreogadus saida

Abstract As part of the Chukchi Sea Offshore Monitoring in Drilling Area-Chemical and Benthos (COMIDA CAB) project, we determined the distribution and concentrations of aliphatic n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in surface sediments (0–1 cm) among 52 sites across the Chukchi Sea and in muscle tissues of the benthic Northern whelk, Neptunea heros, collected opportunistically. In addition, downcore profiles of contaminants were determined at three targeted sites to establish historic patterns. Baseline responses of PAH exposure and its potential toxicological effects were examined in the common Arctic cod, Boreogadus saida, through measures of cytochrome P4501A/ ethoxyresorufin O-deethylase (CYP1A/EROD), glutathione-S-transferase (GST), and Cu/Zn superoxide dismutase (SOD) activity in liver tissue. The total concentration of PAHs in surface sediments throughout the study area, including parent and alkyl-homologs, were very low (
The Effects of Flooding Duration and Salinity on Three Common Upper Estuary Plants

Although the effects of permanent flooding on biomass of coastal marsh plants has been extensively documented, the effect of duration of flooding has received little attention. Panicum hemitomon, Sagittaria lancifolia, and Spartina patens were exposed to three flooding durations (day, week, month) and two salinity regimes (0 and 6 ppt) for 3 months. All flooding treatments resulted in the plants being flooded 50 % of the 3 month experimental period. Panicum hemitomon experienced 100 % mortality at 6 ppt but was unaffected by flooding duration at 0 ppt. Sagittaria lancifolia growth and biomass were reduced by both increased salinity and flood duration. Spartina patens growth was unaffected by both flooding and salinity. However, a significant interaction term indicated that S. patens belowground biomass increased with flood duration under fresh conditions but decreased with flood duration under brackish conditions. Examination of the growth patterns showed reduced growth of the grasses when the soil was inundated. Growth of S. lancifolia was reduced at times, when leaves were being replaced, but the pattern did not coincide with flooding and may reflect a specific leaf turnover cycle in this species. Restoration of coastal regions involves manipulation of estuarine hydrology, which can be improved using these study results.
Structure of zinc polyphosphate glasses studied by two-dimensional solid and liquid state NMR

Abstract A series of 10 binary zinc phosphate glasses with composition x ZnO+(1− x )P 2 O 5 (0.35≤ x ≤0.80) is studied by means of two-dimensional (2D) solid and liquid state 31 P nuclear magnetic resonance (NMR). Double quantum (DQ) filtering method is used to probe 31 P– 31 P connectivities through dipolar interactions in solid samples. Similar information is obtained using the correlation spectroscopy (COSY) experiment in solution. It is shown that these 2D NMR methods are capable of scrutinizing the evolution of glass structure versus x with improved precision. Varied relative concentrations of dimers, short or long branched chains and ring structures are found in glasses with different composition. Average chain length in the glasses is determined from the NMR results and compared with HPLC data and theoretical predictions. Finally, the evolution of glass structure is studied as a function of the synthesis temperature.
Micro-Electro-Mechanics of Ionic Polymeric Gels As Electrically Controllable Artificial Muscles

Ionic polymeric gels are three-dimensional networks of cross-linked macromlecular polyelectrolytes that swell or shrink in aqueous solutions on addition of alkali or acids, respectively. Reversible dilation and contraction of the order of more than 1000 percent have been observed in our laboratory for polyacrylonitrile (PAN) fibers. Furthermore, it has been experimentally observed that swelling and shrinking of ionic gels can also be induced electrically. Thus, direct computer control of large expansions and contractions of ionic polymeric gels by means of a voltage gradient appears to be possible. These gels possess an ionic structure in the sense that they are generally composed of a number of fixed ions (polyions) pertaining to sites of various polymer cross-links and segments and mobile ions (counter ions or unbound ions) due to the presence of a solvent which is electrolytic. Electrically-induced dynamic deformation of ionic polymeric gels such as polyacrylic acid plus sodium acrylate cross-linked wi...
An evaluation of the quantum efficiency of optical heterodyne detectors

Measurements are presented which verify the previous theoretical analysis of photomixers. A review of the theory is presented and theoretical predictions of the performance of a device are made. The measurements on the device are discussed and compared to the theory.
Alterations in intestinal epithelial cell proliferation and apoptosis after APC gene therapy and selective COX-2 inhibition in the Min mouse

Purpose: The Multiple intestinal Neoplasia (Min) mouse has been proved to be an ideal model for intestinal tumorigenesis. Mutated for the murine homolog of the Adenomatous Polyposis Coli (APC) gene, these mice develop polyps throughout the intestinal tract. Min mice studies have shown alterations in apoptosis and cell migration in areas of the intestinal epithelium that do not harbor polyp formation that may be mediated through increased cyclooxygenase 2 (COX-2) activity. Our laboratory has successfully reduced polyp formation in the Min mouse through introduction of a human APC construct transorally via liposomes. We describe our results on intestinal cell proliferation and apoptosis in the Min mouse after APC gene therapy and selective COX-2 inhibition.
Variation in the rate of DNA chain growth through the S phase in HeLa cells

Abstract At five to six hours after the beginning of the S phase, the over-all rate of HeLa cell DNA synthesis is about five times as great as in early S cells. This is due both to an increased number of growing points and to a doubling of the average rate of growth along replicons. The pattern of replicon operation in HeLa cells is changed when the “thymidine double-block” method is used to induce synchrony.
A tyrosine-free medium for the selective growth of cells expressing phenylalanine hydroxylase activity.

Abstract Tyrosine-free modified Ham's F-12 medium supplemented with charcoal-extracted serum permits the exclusive propagation of cultured cells containing detectable levels of phenylalanine hydroxylase. The selective properties of this medium have been verified with two phenylalanine hydroxylase-positive (H4-II-E-C3 and MH1C1) and two phenylalanine hydroxylase-negative (HTC and BRL) cell lines. Although cocultivation experiments revealed that BRL cells could replicate slowly in the selective medium in the presence of sufficient numbers of H4-II-E-C3 cells, the former cells did not survive subcultivation in this medium at low cell inoculum (
Calcification of osteoblastlike rat osteosarcoma cells in agarose suspension cultures

Ros 17/2 clonal rat osteosarcoma cells calcify when cultured in the presence of 10 μg/ml β-glycerol phosphate in an agarose gel. Culture in 1% agarose inhibited cell division while allowing cells to remain metabolically active and viable for over 21 days. Serial photography of the same microscopic field shows a progressive deposition of calcium phosphate during the course of the experiment. The deposition of calcium around cells was confirmed by calcium-specific stains, and by energy dispersive X-ray analysis (EDX) during scanning electron microscopy. Cells with high calcium content analyzed by EDX had Ca:P ratios similar to hydroxyapatite. Total calcium progressively increased in β-glycerol phosphate-treated cultures whereas the control plates maintained a constant calcium content over 16 days. Alkaline phosphatase activity increased with time in culture whereas cells with β-glycerol phosphate maintained the alkaline phosphatase values achieved at the time of initial calcification. Alkaline phosphatase staining revealed no correlation between the presence of the enzyme activity and calcification. Radioimmunoassay for the bone-specific vitamin K-dependent protein bone Gla protein showed that β-glycerol phosphate-treated cells accumulate over sixfold greater amounts of this protein. Our studies show that ROS cells can calcify and accumulate bone-specific matrix components when cultured in a 3-dimensional agarose matrix.
Forest buffalo prefer clearings to closed-canopy forest in the primary forest of northern Congo

During 1993–2000 the conservation status of forest buffalo Syncerus caffer was investigated in the Nouabale-Ndoki National Park region, northern Congo. Data from dung counts collected during a number of ecological reconnaissance surveys in and around the National Park showed that the preferred buffalo habitat was open canopy swamps and forest clearings associated with watercourses. Buffalo abundance was very low in terra firma forest more than 250 m from water, and signs were restricted to large elephant trails connecting watercourses and clearings. The clumped distribution of the buffalo appeared to be a result of the highly patchy distribution of their food resources. In terra firma forest preferred food species were poorly represented, whereas in open swamp and sedge clearings they were more abundant. Low overall numbers, highly patchy distribution, small group size, and low effort-high return for hunters, including sport hunters, mean that buffalo must be considered a conservation priority in this environment.
Development of Crash-Safe Turbine Fuels

The Federal Aviation Administration is engaged in programs to reduce the probability and/or severity of fire in commercial jet transport aircraft that are involved in ground crash situations. One of the approaches being taken is the development of a modified aviation turbine fuel that will provide a significant reduction in the crash-fire hazard. The modified fuels program, initiated in 1964, brought to light that under small-scale simulated crash conditions the fire reduction benefits of fuel thickeners result from their ability to physically bind the fuel and thus reduce the rate of vaporization and the exposed surface area available to support a fire. Dozens of thickened fuel candidates have undergone cursory screening, and a small percentage of those that looked promising have been subjected to a crash fire rating system designed to provide relative values of candidate fuels. Chemical and physical studies, completed in 1971, on two of the leading fuel candidates greatly improved their fluidic property with no adverse affect on their fire retardative properties, while in mist form. The agency’s plans, to demonstrate the safe operation of aircraft using a modified fuel and to demonstrate the improvement in crash fire safety by conducting full-scale crash tests, are proceeding to take shape due primarily to the continued progress being made by the developers of the gelled fuels.Copyright © 1972 by ASME
Comparative biochemistry of folate metabolism in Aphelenchus avenae and Nippostrongylus brasiliensis (Nematoda).

Abstract 1. 1. Dihydrofolate reductase, formyl tetrahydrofolate synthetase and methylene tetrahydrofolate dehydrogenase were compared in Aphelenchus avenae and Nippostrongylus brasiliensis. 2. 2. Dihydrofolate reductase activity was highest in N. bransiliensis. 3. 3. Methylene THF dehydrogenase activity was similar in both species. 4. 4. Formyl THF synthetase activity was highest in the infective larvae of N. brasiliensis 5. 5. Formyl THF synthetase was partialy purified from A. avenae and N. brasiliensis. 6. 6. The Km for tetrahydrofolate was lower for formyl THF synthetase from A. avenaebut the Km's for ATP and formate were similar for the enzyme in both nematodes.