cssi/SciSciGPT-SciSciNet huggingface dataset:
Controlling chaos in the brain

In a spontaneously bursting neuronal network in vitro, chaos can be demonstrated by the presence of unstable fixed-point behaviour. Chaos control techniques can increase the periodicity of such neuronal population bursting behaviour. Periodic pacing is also effective in entraining such systems, although in a qualitatively different fashion. Using a strategy of anticontrol such systems can be made less periodic. These techniques may be applicable to in vivo epileptic foci.
Molt‐independent growth inhibition of Daphnia magna by a vertebrate antiandrogen

The objective of this study was to identify specific physiologic parameters in crustaceans that are targeted by chemicals known to be antiandrogenic in vertebrates. We hypothesized that chemicals capable of binding to the vertebrate androgen receptor would also elicit toxicity to crustaceans by binding to specific steroid hormone receptors in an antagonistic manner. This hypothesis was tested by evaluating the effects of the antiandrogen cyproterone acetate on growth, molting, sexual differentiation, and reproduction of Daphnia magna. Exposure of daphnids to concentrations of cyproterone acetate appreciably below those that elicited mortality reduced growth but had no effect on molting. These concentrations of cyproterone acetate had no effect on various developmental and maturation parameters. Cyproterone acetate also reduced the number of offspring produced by parthenogenetically reproducing daphnids, but this effect appeared to be a consequence of the reduced size of the daphnids and their inability to accommodate a brood of more than approximately 10 eggs. These results indicate that the antiandrogen cyproterone acetate specifically targets a process critical to growth of daphnids that is independent of molting. Additional studies are warranted to established whether this is an endocrine-related toxicity to crustaceans that is associated with environmental antiandrogens such as some pesticide metabolites.
The ether-catalyzed dissociation rate of estradiol-receptor complex distinguishes between hormone-sensitive and resistant rat mammary tumors.

Abstract MTW9-MtT. a rat mammary tumor which does not show ovariectomy-induced regression (OIR) has been compared with MTW9-P. a tumor which does show OIR. The tumors were compared to rat uterus by studying the exchange of [3H]-estradiol with receptor bound estradiol in the presence and absence of 2% v/v ether. The exchange rate is limited by the dissociation of receptor-hormone complex. The exchange rate of cytosol receptor is increased by addition of ether to reaction mixture. Ether increases the rate of Mt-MtT receptor exchange much more than the exchange of MT-P although in the absence of ether the tumors showed similar dissociation rates. It is not yet known whether kinetic differences are related to the capacity to undergo OIR.
Stereographic projections of experimental electron density distributions

The determination of electron density distributions in solids by X-ray (and neutron) diffraction has been applied to many different types of solids (for a survey see Coppens, 1975; Coppens and Stevens, 1977). Although several ways of illustrating the results are known (Smith and Absar, 1977), it is most common to display contour plots of the density distribution in planar sections through the molecule. However, significant features above and below a plane may easily be missed with this technique, and even when many sections are plotted the relative position of different density features and their possible chemical significance is not easily understood. A useful alternative is to display the charge density on the surface of a sphere about a point in stereographic projection (Fig. 1). The density on a spherical surface is projected on to a plane, and appears as if viewed from the opposite side of the sphere. Stereographic projections are described in detail in several texts (Azfiroff, 1968; Nuffield, 1966). Stereographic projections of the electron density are of particular value in revealing both the hybridization of atoms with lone-pair density and the orientation of the lone-pair peaks with respect to hydrogen bonds or neighboring ions. Also, the relationship of the crystal field to the location of density peaks from the partially filled d shell of transition metal atoms can be effectively displayed in a stereographic projection. Electron density distributions in stereographic projection have been presented by Stevens and co-workers (1976) showing the lone-pair density about some oxygen atoms, and by Rees and Mitschler (1976) showing the
Epitaxial lateral overgrowth (ELO) of homoepitaxial diamond through an iridium mesh

Abstract In the present work iridium layers forming a mesh on diamond have been studied as potential candidates for buried electrodes or stopping layers in an ELO process for heteroepitaxial diamond. Thin iridium layers (∼ 15 nm) were deposited by e-beam evaporation at ∼ 700 °C on the facets of individual (001)-oriented CVD diamond crystallites and macroscopic Ib HPHT substrates with off-axis angles of several degrees. The heteroepitaxial iridium films formed a mesh with 10–200 nm large holes. These were penetrated by homoepitaxial diamond in a microwave plasma chemical vapour deposition process (MWPCVD) burying the iridium layer completely after 15 min of diamond growth. High resolution X-ray diffraction including reciprocal space mapping and Raman spectroscopy was used to characterize the structural properties of the diamond overlayer on the Ib HPHT substrate. It was monocrystalline with an FWHM of 0.03–0.05° of the X-ray rocking curve. Its lattice planes were tilted by ∼ 0.01° with respect to the substrate and showed a macroscopic strain of − 10− 4 perpendicular to the surface. Besides the smaller lattice constant due to the lack of nitrogen the strain is mostly attributed to a tensile in-plane stress state. Strain and tilt can be attributed to the lateral overgrowth and the off-axis angle of the substrate.
Multilevel homogeneity analysis with differential weighting

In this paper we extend the technique of homogeneity analysis and nonlinear principal components analysis to a multilevel sampling design framework. We also propose a model that differentially weights the groups of objects, and thus allows us to make within- and between-groups comparisons. A data set from the National Educational Longitudinal Study (NELS:88) is used to illustrate the techniques introduced in the paper.
Performance characteristics of lithium coin cells for use in wireless sensing systems: Transient behavior during pulse discharge

Abstract An understanding of the pulse discharge behavior of commercial lithium coin cells in wireless sensing systems (WSs) is critical to prolonging the operating life and/or reducing the size of such systems. This paper is part of an effort to examine, model and optimize battery performance for sensor duty cycles consisting of multiple pulse discharges. The transient behavior of the cells during pulse discharge and the relaxation behavior following the pulse are both investigated with single-pulse experiments, and described with a simple mathematical model. In both cases, the voltage response is characterized by a region of rapid change, associated with ohmic and interfacial resistances, followed by a region of slower change. Solid phase diffusion in the cathode is the major contributor to the “slow” voltage change that occurs during and after a pulse. A simple analytical model, validated for this system, was found to accurately describe the time-dependent voltage and the corresponding non-uniform concentration distribution for the porous electrode. This transient study provides insight into and a description of the factors that influence and control battery behavior during pulsed cycling, and provides a tool to enable the next generation of battery-aware design of autonomous wireless sensing systems.
“Ultramicroporous” silica-based supported inorganic membranes

Ultramicroporous (Pore radius < 10 A) separation layers with thicknesses in the range of 200–1200 A were deposited from polymeric silicate sols onto commercial alumina supports using a dip-coating/casting procedure. The silicate sols were prepared using a two-step acid-catalyzed hydrolysis of tetraethoxysilane under pH conditions where the condensation rate is low, producing polymers of low fractal dimension which readily interpenetrate during film deposition to provide amorphous layers with extremely small pore sizes. At low aging times (t/tgel=0.05), the acid catalyst concentration had a dramatic effect on the deposited membrane permeability. Using 1N HCl a discrete, featureless membrane layer was deposited on top of the mesoporous support (as revealed by TEM), while lower acid concentration (0.44 N) resulted in polymer penetration and filling of the support pores rather than the deposition of a discrete external layer. This was attributed to the effect of acid concentration on the polymer condensation rate during the final stages of membrane deposition and drying. Deposited membrane layer thickness was found to depend on sol aging time, solvent dilution, and dipping/casting time. Helium permeabilities for deposited layers were ∼ 1000–2000 barrer. Measured reductions (65–90%) in the helium and nitrogen permeation rates upon membrane deposition indicated pore radii less than 10 A for the deposited membrane layers.
Development of a critical item algorithm for the Baby and Infant Screen for Children with aUtIsm Traits

Abstract Autism is defined by impairments in socialization, communication, with the presence of stereotyped behavior. It is also associated with various medical conditions, intellectual disability, comorbid psychopathology, and problem behavior. This is a concerning finding in that there may be a true increase in the disorder's prevalence and that it is associated with poor long-term outcomes. Fortunately, effective treatments exist that can alter the course of the disorder if administered early in a child's life. A method to facilitate early intervention is through the early screening of autism with instruments such as the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT). The primary purpose of the current investigation was to further develop the utility of the BISCUIT by creating an abbreviated scoring algorithm. Participants included 2168 children ages 17–37 with an autism spectrum disorder or atypical development enrolled in an early intervention program. Discriminant function analysis (DFA) and receiver operating characteristic (ROC) analysis were conducted resulting in a 5 item scoring algorithm with comparable diagnostic accuracy to the existing scoring procedure. Implications for these data and directions for further research are discussed.
Codes For Optical Recording

Codes for optical recordingJordan IsailovicCalifornia State University FullertonFullerton, California 92634AbstractOptical recording systems capable of information storage and retrieval, using a highly focused laser beamas the recording and playback source, have been developed to a point where products are introduced. Many vari-ties of archival write once, or nonalterable, optical storage media have been proposed and developed.Reversible or erasable optical storage media have been the subject of research since the earliest days of op-
The Role of Dopamine in the Behavioral Effects of Caffeine in Animals and Humans

Dopamine has been proposed to mediate some of the behavioral effects of caffeine. This review discusses cellular mechanisms of action that could explain the role of dopamine in the behavioral effects of caffeine and summarizes the results of behavioral studies in both animals and humans that provide evidence for a role of dopamine in these effects. Caffeine is a competitive antagonist at adenosine receptors and produces a range of central and physiological effects that are opposite those of adenosine. Recently, caffeine has been shown to enhance dopaminergic activity, presumably by competitive antagonism at adenosine receptors that are colocalized and interact functionally with dopamine receptors. Thus, caffeine, as a competitive antagonist at adenosine receptors, may produce its behavioral effects by removing the negative modulatory effects of adenosine from dopamine receptors, thus stimulating dopaminergic activity. Consistent with this interpretation, preclinical behavioral studies show that caffeine produces behavioral effects similar to classic dopaminergically mediated stimulants such as cocaine and amphetamine, including increased locomotor activity, increased turning behavior in 6-hydroxydopamine-lesioned animals, stimulant-like discriminative stimulus effects, and self-administration. Furthermore, caffeine potentiates the effects of dopamine-mediated drugs on these same behaviors, and some of caffeine's effects on these behaviors can be blocked by dopamine receptor antagonists. Although more limited in scope, human studies also show that caffeine produces subjective, discriminative stimulus and reinforcing effects that have some similarities to those produced by cocaine and amphetamine.
Facile assay of enzymes unique to the Calvin cycle in intact cells, with special reference to ribulose 1,5-bisphosphate carboxylase☆

Abstract A procedure for the facile measurement, in intact cells, of two enzymes unique to the Calvin cycle, ribulose 1,5-bisphosphate carboxylase and phosphoribulokinase, is described. The procedure involved a simple toluene treatment to render phototrophic cells permeable to the necessary substrates, effectors, and cofactors. Whole-cell ribulose 1,5-bisphosphate carboxylase activity quantitatively approximates the activity obtained in cell-free extracts. In addition, the activity measured with toluene-treated whole cells results in a stoichiometric carboxylation of ribulose 1,5-bisphosphate to phosphoglyceric acid. The assay procedures described are most convenient for determining enzyme levels as a function of growth. Moreover, such an assay should open the way to further studies on the regulation of CO 2 assimilation by direct measurement of the enzymes concerned within the cell.
Incipient-boiling superheat for sodium in turbulent, channel flow: Effects of heat flux and flow rate☆

Abstract An experimental study was carried out in which the effects of heat flux and velocity on the incipient-boiling superheat were determined for turbulent flow of sodium in an annular channel. The heating surface was polished type-316 stainless steel having a profilometer roughness of 14–18 μin. (rms). The rate of temperature rise of the heating surface was maintained constant in each incipient-boiling run, by gradually increasing the inlet sodium temperature to the test section, while the heat flux on the heater was held constant. In this way, the independent variables of heat flux and rate of temperature rise were separated. For a finite rate of temperature rise, it was found that the greater the heat flux, the greater was the incipient-boiling superheat, other things being equal. It was also found that the greater the rate of temperature rise, the greater was the effect of heat flux. The flux was varied over the range 25 000–300 000 Btu hft 2 . In general agreement with published results of previous investigators, the incipient-boiling superheat was found to have a strong dependence on the flow rate, falling off exponentially as the flow rate was increased. The axial location of boiling inception was determined by means of a series of voltage taps spaced along the outer wall of the test section; and the results presented herein represent superheat values for, and nucleations at, the upper end of the heater, or at the highest heating-surface temperature in the testsection channel.
Electron attachment and ‘carrier gas’ energy distribution functions

Abstract Experimental data are presented which provide a comparison of the electron energy distribution functions for the gases C 2 H 4 , N 2 and Ar, used in electron attachment studies. Standard carrier gases for swarm studies alone or combined with electron beam data are recommended.
Work in Progress: Introducing Electrical and Computer Engineering to High School Math and Science Students

This paper describes the recent activities of Electrical and Computer Engineering doctoral students in the design, development, and implementation of lessons for high school mathematics and science classes. The graduate students, called Fellows, worked in secondary classrooms in the Cincinnati Public Schools District as a part of Project STEP at the University of Cincinnati, which is funded by the National Science Foundation GK-12 Program. The Fellows formed partnerships with secondary math and science teachers to generate new lessons, activities, and resources to enhance the STEM skills of high school students. Additionally, the Fellows used their engineering expertise to bring authentic learning experiences into the classroom and introduced concepts in their field of engineering to underserved student populations. This paper discusses observations and reflections by the Fellows regarding aspects of the activities that had the most impact on student learning and interest in engineering, which was measured by self-reported student surveys.
Principles in judgment/decision making research pertinent to legal proceedings

Principles in the judgment/decision making literature relevant to the legal community are reviewed. These principles are divided into four areas: the decision process itself, communicating a judgment to others, evaluating a decision, and possible ways of “debiasing.” Several influences on the decision process are enumerated, among them being insufficient consideration of base rates, selective memory for relevant material, the framing of the decision in either the domain of losses or the domain of gains, and consideration of the “cues to causation.” Particular attention is paid to suboptimal consideration of covariation information. In communicating the decision to others the two most prominent findings are overconfidence in expressing one's decision and the inability to describe accurately the bases of one's decision. Evaluating a decision is plagued by two biases. The first is the hindsight bias. After an event has occurred we tend to exaggerate how easily we could have predicted the event beforehand. The second is the outcome bias. We tend to base our evaluation of the decision upon the evaluation of the outcome. Among the debiasing techniques mentioned are the admonition to “consider the opposite” of the preferred option, the reduction of reliance on memory, and the use of decision aids.
Practicable X-Ray Amplifier

Inverted populations of practical interest in the x-ray region are obtainable from selective inner-shell vacancy production in intermediate-energy ion-atom collisions. A high-current ion beam swept at nearly the speed of light along the length of an extended foil provides an active region in synchronization with a resonant x-ray pulse traveling parallel to the foil surface. Significant amplification may be realized with presently available ion sources.
Troy and the Arauco in the Alpujarras: global visions and local destinies in Guerra de los moriscos (Part 2 of Guerras Civiles de Granada)

This essay examines the transformation of the landscape into a maritime space in Gines Perez de Hita's narration of the episode of Galera in his Guerra de los moriscos. By identifying the Alpujarras with Augustan landscapes, the author places the text in a dialectical relationship with the most famous epic account of the indigenous rebellion in Chile: Alonso de Ercilla's La Araucana. The suggestive panoramas that emerge from this refiguration of the topography yield unexpected connections between contested places within the Spanish world (Alpujarras–Mediterranean–Chile–North Africa). Moreover, this network of places situates the rebellion vis-a-vis a decisive battle in the struggle for the Mediterranean: Lepanto. Through his highly original geography, Perez de Hita advances novel notions of global expansion that call into question the political and moral consequences of the imperial enterprise and reveal the fragmentary nature of ostensibly powerful, monolithic global structures.
Multiple index structures for efficient retrieval of 2D objects

Many applications require the storage and management of large databases of 2D objects. One of the important functionalities required by all of these applications is the capability to find objects in a database that match a given object. We concentrate on whole matching queries, in which a query object is compared with a set of objects to find the ones that are either exactly identical or similar to the query object. There are two obstacles for efficient execution of whole-match queries. First, the general problem of comparing two 2D objects under rotation, scaling and translation invariance is known to be computationally expensive. Second, the size of the databases are growing, and hence a query should be answered without accessing all the objects in the database. To address both obstacles, we identify a set of six features that could be extracted from the objects' minimum bounding circle (MBC). These are: the radius of the MBC, the coordinates of the center of MBC, the set of touch-points on the MBC, the touch-points angle sequence, the vertex angle sequence and the start-point of the angle sequence. The features are unique per object and can be utilized for both efficiently indexing the objects and expediting the comparison between two objects. We focus on three variations of match queries: an exact shape match, an exact match with rotation, scaling or translation, and similarity shape retrieval.
Selective inhibition of transcytosis by brefeldin A in MDCK cells.

Abstract Treatment of most cells with brefeldin A (BFA) leads to the retrieval of the Golgi complex to the endoplasmic reticulum, presumably reflecting an inhibition of cytoplasmic coat protein binding to Golgi membranes. Although BFA has been thought to act only on biosynthetic organelles, we now show that this drug also reversibly blocks polymeric immunoglobulin receptor-mediated transcytosis in MDCK cells. The action of BFA on transcytosis was selective, since internalization, recycling, and intracellular degradation were unaffected. The block occurred early on the transcytotic pathway, probably before the translocation of IgA-containing vesicles from the basal to the apical cytoplasm. Although BFA caused MDCK cell endosomes to become more tubular, the organization of the Golgi and binding of the 110 kd Golgi coat protein β-COP was surprisingly unaffected. These results suggest that in MDCK cells, endocytic organelles contain a BFA-sensitive coat that regulates their organization and function even though the Golgi coat is BFA resistant.
Discontinuous DNA replication in vitro. I. Two distinct size classes of intermediates.

THE replication of the Escherichia coli chromosome consists of several physiologically and genetically distinguishable stages: the initiation of chromosomal replication, the polymerization of the daughter strands by the replication fork, and termination and segregation of the daughter chromosomes1. These biochemical events, even those which take place at the replication fork as it is going along the circular E. coli chromosome, are complex. They do not correspond to the simple picture of two enzymes elongating the two daughter strands. Okazaki et al.2 have found that short DNA molecules (Okazaki pieces) are synthesized as intermediates in DNA replication. Three stages occur in the life of these DNA intermediates, chain initiation, elongation of the initiated chain, and joining of the chains. This last step presumably requires the activity of the enzyme polynucleotide ligase3,4. To try and analyse the mechanism of replication we have examined chain initiation and propagation in vitro in the absence of joining.
Differential effects of O-demethyl encainide on induced and spontaneous arrhythmias in the conscious dog☆

Abstract Encainide is highly effective in suppressing most nonsustained ventricular arrhythmias, but there is evidence that the drug is less effective and may worsen some arrhythmias, particularly in patients with sustained ventricular tachycardia. In most patients it is likely that the major antiarrhythmic effects of encainide are mediated through a potent metabolite, O-demethyl encainide. The effects of infusions of saline solution or O-demethyl encainide on spontaneous ventricular ectopic activity and ventricular fibrillation (VF) threshold were compared in 25 dogs with a mottled myocardial infarct produced by transient coronary occlusion. Plasma levels of the metabolite above 100 ng/ml suppressed (> 92%) the spontaneous ventricular ectopic activity that occurred 48 hours after MI, whereas saline solution had no effect. In 15 dogs treated with O-demethyl encainide, the VF threshold decreased an average of 23%, from a baseline level of 23 ± 8 mA to 18 ± 9 mA (p 1,000 ng/ml), VF was induced by right ventricular pacing alone (S 1 S 1 300 ms). No change in VF threshold was observed in the 8 dogs treated with saline solution, and in each of these dogs VF could be terminated by the countershock protocol. However, in 7 of the 17 dogs treated with O-demethyl encainide, VF could not be terminated by the countershock protocol. These 7 dogs, which died from VF, had higher O-demethyl encainide levels (314 ng/ml or above) than the other 10 dogs. It is concluded that O-demethyl encainide is effective in suppressing spontaneous ventricular ectopic activity in this model of myocardial infarction, but at plasma levels higher than 150 ng/ml, the agent lowers the VF threshold and at higher levels impedes defibrillation.
An examination of the force constant models for tungsten in view of its surface dynamical properties

The bulk phonon spectra of transition metals can be accurately accounted for by force constant models. In order to reproduce the surface dynamical properties, it is customary to modify bulk parameters at the surface. However, there are several force constant models available for a particular transition metal, and they yield widely varying surface dynamical properties (before changing model parameters). It is therefore natural to ask if a force constant model can be constructed, which simultaneously accounts for bulk as well as surface dynamical properties. This question is addressed here, by considering bulk tungsten and its (001) surface. By constructing linear least squares fits, it is found that such a model cannot be constructed, even if it is “improved” by incorporating a large number of parameters.
Amplitude and phase versus angle for elastic wide-angle reflections in the τ‐p domain

ABSTRACTNear- and postcritical spherical-wave reflections contain amplitude and phase variations with incident angle that are not predicted by plane-wave solutions. However, if a spherical wavefield is decomposed into plane waves by a time-intercept-slowness (τ‐p) transform, then plane-wave reflection coefficients (the Zoeppritz) can be used as the basis of amplitude/phase versus angle analysis. The spherical-wave effects on reflection coefficients near the critical angle (in the time-offset domain) were decomposed by τ‐p transformation into plane waves. Kinematic ray tracing linked the reflection angle at the target reflector and the apparent slowness at the surface receiver, which enabled extracting the amplitude/phase versus angle data at the reflector from the surface τ‐p data. The most reliable inversion results were obtained by combining the extracted amplitudes and phases in a composite inversion for the elastic parameters below the target reflector.
Lymphocyte fate specification as a deterministic but highly plastic process

The cellular progeny of a clonally selected lymphocyte must execute function. However, their function must often occur in more than one way, in more than one place and at more than one time. Experimental evidence supports the view that a single activated lymphocyte can produce a variety of cellular descendants. The mechanisms that are responsible for generating diversity among the progeny of a single lymphocyte remain a subject of lively controversy. Some groups have suggested stochastic mechanisms that are analogous to the diversification of the antigen receptor repertoire. We suggest that the complexity of lymphocyte fates in space and time can be derived from a single naive lymphocyte using the principles of cell diversification that are common in developmental and regenerative biology, including (but not limited to) asymmetric cell division.
Nucleation and flashing in nozzles—1. A distributed nucleation model

Abstract It is well known that both the number and size of bubbles must be accurately determined for the initial calculation of flashing void development downstream of flashing inception in ducts, nozzles and restrictions. This paper presents a new method of accurately determining both for small geometries with water, which results in accurate calculation of the downstream void development. A wall cavity model is described for use in the calculation of nucleation rates and bubble number densities at flashing inception, and subsequently in the calculation of the void development downstream of minimum area zones in nozzles. The model is based on the physics of the nucleation phenomena in flashing and considers transient conduction to be the sole means of heat transfer from the superheated liquid to the vapor bubble. The activation criterion developed for site nucleation is one-sided, due to the uniform superheat, rather than two-sided as in boiling. A figure of merit for the particular fluid solid combination is then determined which yields the minimum nucleation surface energy per site. Characteristic site nucleation frequencies and the number densities of nucleation sites of given sizes are then obtained from the data, providing the first link between a surface-characteristic-based nucleation and evaporation model and global behavior. Throat void fractions for all data found in the literature are , confirming earlier assumptions. A bubble transport equation is used to predict the number density and size of bubbles at the throat. Throat superheats are then calculated for all throat superheats up to ≈100 K and expansion rates between 0.2 bar/s to over 1 Mbar/s, with a standard deviation of 1.9 K. This extends previous correlations by more than 3 orders of magnitude. As a result, flow rates can be calculated to within 3% of measured values using a combination of single-phase theory and accurate calculation of the throat pressure under critical conditions. This provides a valuable consistency check to independent critical flow predictions.
Representative Case Research: A Way of Knowing

Representative case research applies principles of personology and the human sciences to psychological inquiry. Carefully chosen persons are examined one at a time to learn how each experiences and manages an event, situation, or set of circumstances or conditions that are important in human life. Such research requires the collaboration of a technically competent initiating investigator and a coinvestigator, who serves as an expert consultant because he or she knows about the topic of interest at first hand. A supervisor and advisors are also included on the research team. The research is carried out in cycles; all information and interpretations are repeatedly submitted to the coinvestigator for examination, clarification, and comment.
A multiscale model linking ion-channel molecular dynamics and electrostatics to the cardiac action potential

Ion-channel function is determined by its gating movement. Yet, molecular dynamics and electrophysiological simulations were never combined to link molecular structure to function. We performed multiscale molecular dynamics and continuum electrostatics calculations to simulate a cardiac K+ channel (IKs) gating and its alteration by mutations that cause arrhythmias and sudden death. An all-atom model of the IKs α-subunit KCNQ1, based on the recent Kv1.2 structure, is used to calculate electrostatic energies during gating. Simulations are compared with experiments where varying degrees of positive charge—added via point mutation—progressively reduce current. Whole-cell simulations show that mutations cause action potential and ECG QT interval prolongation, consistent with clinical phenotypes. This framework allows integration of multiscale observations to study the molecular basis of excitation and its alteration by disease.
Biosynthetic tailoring of microcin E492m: post-translational modification affords an antibacterial siderophore-peptide conjugate.

The present work reveals that four proteins, MceCDIJ, encoded by the MccE492 gene cluster are responsible for the remarkable post-translational tailoring of microcin E492 (MccE492), an 84-residue protein toxin secreted by Klebsiella pneumonaie RYC492 that targets neighboring Gram-negative species. This modification results in attachment of a linearized and monoglycosylated derivative of enterobactin, a nonribosomal peptide and iron scavenger (siderophore), to the MccE492m C-terminus. MceC and MceD derivatize enterobactin by C-glycosylation at the C5 position of a N-(2,3-dihydroxybenzoyl)serine (DHB-Ser) moiety and regiospecific hydrolysis of an ester linkage in the trilactone scaffold, respectively. MceI and MceJ form a protein complex that attaches C-glycosylated enterobactins to the C-terminal serine residue of both a C10 model peptide and full-length MccE492. In the enzymatic product, the C-terminal serine residue is covalently attached to the C4‘ oxygen of the glucose moiety. Nonenzymatic and base-cat...
Influence of nonhost plant diversity and natural enemies on the potato leafhopper, Empoasca fabae, and pea aphid, Acyrthosiphon pisum, in alfalfa

We examined the effects of nonhost plant diversity and predators on the potato leafhopper, Empoasca fabae (Harris), the pea aphid, Acyrthosiphon pisum (Harris), and their primary host plant, alfalfa, Medicago sativa L. Potato leafhopper intensity (i.e., leafhoppers/alfalfa stem density) and plant damage (i.e., hopperburn) were significantly greater in alfalfa mono- than in polycultures of alfalfa mixed with nonhost plant species. There was no significant effect of nonhost plant diversity on pea aphid intensity or on predator abundance. Predator:prey ratios were higher in poly- than in monoculture. One predator, Nabis sp., was selected for further study. A microcosm experiment indicated that Nabis is an effective predator of both herbivores, and suggested that nonhost plant diversity may enhance the predation of leafhoppers by Nabis. These results suggest that nonhost plant diversity and Nabis limit leafhopper populations and protect alfalfa from herbivory. The potential for nonhost plants to increase herbivore movement and vulnerability to predation is discussed.
Attrition and Performance in Japanese Language Courses: A Study of Articulation Between the High School and University Levels.

As the number of students who enter colleges and universities with high school Japanese training has increased, articulation between high school- and university-level Japanese language instruction has become a matter of concern. In order to add to our understanding of the problem of articulation, the author conducted a two-year study in which students with high school Japanese language instruction were compared to those who began their study after entering Indiana University. Their attrition and performance through the first four semesters of instruction were compared. This article reports the finding of that study.
Composition of proteoglycans in the aortas of copper-deficient rats.

Copper deficiency adversely affects the extracellular matrix of the arterial wall, leading to cardiovascular lesions. To study the lesions resulting from copper deficiency, the composition of proteoglycans from aortas of copper-deficient rats was compared with proteoglycans of aortas from copper-supplemented rats. Copper deficiency in rats was verified by copper levels in adrenal glands (mean f SE, 0.37 f 0.07 vs 1.03 f 0.17 bg/g wet wt in supplemented rats). The proteoglycans were isolated from the aorta by extraction with 4 M guanidine-HCI and by digestion of the tissue with elastase. The proteoglycans were purified by CsCl isopycnic centrifugation and fractionated by gel filtration. The fractions were characterized for molecular size and glycosaminoglycan composition. Total uronate in the aortas from copper-deficient rats was 25% greater than in aortas from copper-supplemented rats, and the proteoglycans from copper- deficient rat aortas were of greater molecular size. Among the glycosaminoglycans the concentration (pg/mg tissue) of isomeric chondroitin sulfates, particularly dermatan sulfate, was greater in copper-deficient animals than in copper-supplemented animals. These observations are similar to earlier findings in experimental atherosclerosis and to a response of cardiovascular connective tissue to injury. (P.S.E.B.M. 1989, Vol 1901
ACETONE‐SENSITIZED DIMERIZATION OF CYTOSINE DERIVATIVES*

— Irradiation of cytosine derivatives in aqueous solution in the presence of acetone with light of wavelength > 290 nm results in the formation of cyclobutane-type dimers. A mixture of cis-syn, cis-anti and trans-anti isomers are formed, the trans-anti dimer being the major product. The trans-anti isomers have been isolated as crystalline products and are found to be fairly stable in the solid state. These dimeric products undergo deamination in neutral aqueous solution. In acidic solution monomerization is an important reaction whereas in alkaline solution ring opening is the major mode of degradation. The results of analysis of the photo-products are compared with those of sensitized irradiation of uracil and undine.
Compressive mechanical response of a low-density epoxy foam at various strain rates

We experimentally obtained compressive stress–strain response of a low-density epoxy foam at various strain rates. In particular, compressive stress–strain behavior at intermediate strain rates that has not been previously well understood were characterized by using a modified MTS and a split Hopkinson pressure bar (SHPB). Strain rate effects on the modulus of elasticity and cell-collapse stress for this low-density epoxy foam were determined.
Fuzzy-logic-based sensor fusion for mine and concealed weapon detection

The use of near, mid wavelength and long wavelength infrared imagery for the detection of mines and concealed weapons is demonstrated using several techniques. The fusion algorithms used are wavelet based fusion and Fuzzy Logic Approach (FLA) fusion. The FLA is presented as one of several possible methods for combining images from different sensors for achieving an image that displays more information than either image separately. Metrics are suggested that could rate the fidelity of the fused images, such as, an entropy metric.
Evaluation of Neural Networks for Modeling Nitrate Concentrations in Rivers

Artificial neural networks (ANNs) are applied to estimating nitrate concentrations in a typical Midwestern river, i.e., the Upper Sangamon River in Illinois. Throughout the Midwestern United States, nitrate in raw water has recently become an increasingly important problem. This is due to recent changes in the U.S. EPA nitrate standard and to the increasingly widespread use of chemical fertilizers in agriculture. Back-propagation neural networks (BPNNs) and radial basis function neural networks (RBFNNs) are compared as to their effectiveness in water quality modeling. Training of the RBFNNs is much faster than that of the BPNNs, and yields more robust results. These two types of ANNs are compared to traditional regression and mechanistic water quality modeling, based on overall accuracy and on the frequency of false-negative prediction. The RBFNN achieves the best results of all models in terms of overall accuracy, and both BPNN and RBFNN yield the same false-negative frequency, which is better than that of the traditional models.
Between Poverty and a Lifestyle: The Leisure Activities of Homeless People in Las Vegas

Housed people judge homeless people, and in particular their leisure activities, as indicators of whether that person has chosen a “homeless lifestyle” and therefore deserves homelessness. To achieve a more complex understanding of contemporary homelessness, the author conducted ethnographic fieldwork over ten months in Las Vegas, Nevada, interviewing and participant observing dozens of homeless men and women, including observations of their leisure activities and “free time.” The author argues that homeless people’s pursuit of leisure activities helps explain the popularity of both Las Vegas as a destination for homeless people and why it is a difficult place for homeless people to end their poverty. A consideration of homeless people’s lifestyles in such a postmodern tourist environment also shows how such environments both sustain homeless people and produce homelessness.
In Situ Anaerobic Treatment of Leachate in Landfill Bioreactors

Landfills often serve as ultimate receptors for residential, commercial and industrial wastes. Both hazardous and nonhazardous wastes may be codisposed, but with potential threats to public health and the environment if not properly managed. Therefore, an understanding of the fundamental attenuating mechanisms determining mobilization and potential transport and fate of codisposed waste constituents is needed to direct the selection of appropriate landfill operational and management strategies. By focusing on changes in leachate and gas characteristics during codisposed loadings of organic and inorganic hazardous wastes, the potential treatment capacity of bioreactor landfills with leachate containment and in situ recirculation could be demonstrated.
Effects of prenatal exposure to 2,4-D/2,4,5-T mixture on postnatal changes in rat brain glutamate, GABA, protein, and nucleic acid levels.

The opportunity of maternal exposure to various chemicals in the work place and the general environments have increased, and the fetus and neonate may be at greater risk than the adult. However, the embryotoxic and teratogenic effects of the chlorinated phenoxy herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the main chemicals in Agent Orange, are well documented only in laboratory animals. The brain of the developing fetus is vulnerable to the toxic effects of the phenoxy herbicides which readily cross the placental barrier and distribute into fetal tissues, including brain. Although the neurochemical basis for the behavioral teratogenicity of the phenoxy herbicides is not know, it was recently reported that non-teratogenic doses of a 1:1 mixture of 2,4-D and 2,4,5-T delayed the ontogeny of dopamine and serotonin in the brain of the developing rate. This communication provides further descriptive information about the ontogeny of rat brain nucleic acid, protein, glutamate and ..gamma..-aminobutyrate (GABA) following in utero exposure to non-teratogenic levels of a 1:1 mixture of 2,4-D/2,4,5-T.
Bubbles for relational database

The mechanical disk storage is limited by long initial delay, few inputs/outputs, and serial access, thus necessitating large complex programs in existing database systems in order to map the user's view into the physical storage and to provide different access paths in response to different queries. Bubble devices are capable of set-oriented processing and associative addressing architecture. This paper presents concepts on data structure, storage structure, and access methods for bubble implementation of relational database.
Molecular mechanism of GTPase activation at the signal recognition particle (SRP) RNA distal end.

The signal recognition particle (SRP) RNA is a universally conserved and essential component of the SRP that mediates the co-translational targeting of proteins to the correct cellular membrane. During the targeting reaction, two functional ends in the SRP RNA mediate distinct functions. Whereas the RNA tetraloop facilitates initial assembly of two GTPases between the SRP and SRP receptor, this GTPase complex subsequently relocalizes ∼100 Å to the 5′,3′-distal end of the RNA, a conformation crucial for GTPase activation and cargo handover. Here we combined biochemical, single molecule, and NMR studies to investigate the molecular mechanism of this large scale conformational change. We show that two independent sites contribute to the interaction of the GTPase complex with the SRP RNA distal end. Loop E plays a crucial role in the precise positioning of the GTPase complex on these two sites by inducing a defined bend in the RNA helix and thus generating a preorganized recognition surface. GTPase docking can be uncoupled from its subsequent activation, which is mediated by conserved bases in the next internal loop. These results, combined with recent structural work, elucidate how the SRP RNA induces GTPase relocalization and activation at the end of the protein targeting reaction.
ESTABLISHING A FOOD-CHAIN LINK BETWEEN AQUATIC PLANT MATERIAL AND AVIAN VACUOLAR MYELINOPATHY IN MALLARDS (ANAS PLATYRHYNCHOS)

Avian vacuolar myelinopathy (AVM) is a neurologic disease primarily affecting bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana). The disease was first characterized in bald eagles in Arkansas in 1994 and then in American coots in 1996. To date, AVM has been confirmed in six additional avian species. Attempts to identify the etiology of AVM have been unsuccessful to date. The objective of this study was to evaluate dermal and oral routes of exposure of birds to hydrilla (Hydrilla verticillata) and associated materials to evaluate their ability to induce AVM. Mallards (Anas platyrhynchos) were used in all trials; bobwhite quail (Colinus virginianus) also were used in one fresh hydrilla material exposure trial. Five trials were conducted, including two fresh hydrilla material exposure trials, two cyanobacteria exposure trials, and a frozen hydrilla material exposure trial. The cyanobacteria exposure trials and frozen hydrilla material trial involved gavaging mallards with either Ps...
Value Investing: Bridging Theory and Practice *

Value investing refers to the buying or selling of stocks on the basis of a perceived gap between their current market price and their fundamental value – commonly defined as the present value of the expected future payoffs to shareholders. This style of investing is predicated upon two observations about publicly listed companies and their stock prices: (1) a share of stock is merely a fractional claim on the futures cash flows of an operating business, and that claim is the basis of its long-run value; (2) over shorter horizons, prices can deviate substantially from the long-run value of the stock. Value investors buy stocks that appear to be cheap relative to their intrinsic value and sell (even sell short) stocks that seem expensive.
Reduction of Myocardial Ischemia Reperfusion Injury with Regular Consumption of Grapes

Recently several polyphenolic antioxidants derived from grape seeds and skins have been implicated in cardioprotection. This study was undertaken to determine if the grapes were equally cardioprotective. Sprague Dawley male rats were given (orally) standardized grape extract (SGE) for a period of three weeks. Time-matched control experiments were performed by feeding the animals 45 microg/100 of glucose plus 45 microg/100 g fructose per day for three weeks. After 30 days, rats were sacrificed, hearts excised and perfused via working-mode. Hearts were made ischemic for 30 min followed by two hours of reperfusion. At 100 mg/kg and at 200 mg/kg, SGE provided significant cardioprotection as evidenced by improved post-ischemic ventricular recovery and reduced amount of myocardial infarction. No cardioprotection was apparent when rats were given grape samples at a dose of 50 mg/100 g/day. In vitro studies demonstrated that the SGE could directly scavenge superoxide and hydroxyl radicals which are formed in the ischemic reperfused myocardium. The results demonstrate that the heats of the rats fed SGE reduced myocardial ischemia reperfusion injury by functioning as in vivo antioxidant.