cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermodynamic compensation upon binding to exosite 1 and the active site of thrombin

Several lines of experimental evidence including amide exchange and NMR suggest that ligands binding to thrombin cause reduced backbone dynamics. Binding of the covalent inhibitor dPhe-Pro-Arg chloromethyl ketone to the active site serine, as well as noncovalent binding of a fragment of the regulatory protein, thrombomodulin, to exosite 1 on the back side of the thrombin molecule both cause reduced dynamics. However, the reduced dynamics do not appear to be accompanied by significant conformational changes. In addition, binding of ligands to the active site does not change the affinity of thrombomodulin fragments binding to exosite 1; however, the thermodynamic coupling between exosite 1 and the active site has not been fully explored. We present isothermal titration calorimetry experiments that probe changes in enthalpy and entropy upon formation of binary ligand complexes. The approach relies on stringent thrombin preparation methods and on the use of dansyl-l-arginine-(3-methyl-1,5-pantanediyl)amide and a DNA aptamer as ligands with ideal thermodynamic signatures for binding to the active site and to exosite 1. Using this approach, the binding thermodynamic signatures of each ligand alone as well as the binding signatures of each ligand when the other binding site was occupied were measured. Different exosite 1 ligands with widely varied thermodynamic signatures cause a similar reduction in ΔH and a concomitantly lower entropy cost upon DAPA binding at the active site. The results suggest a general phenomenon of enthalpy-entropy compensation consistent with reduction of dynamics/increased folding of thrombin upon ligand binding to either the active site or exosite 1.
Upregulation of the nitric oxide-cGMP pathway in aged myocardium: Physiological response to L-arginine

Abstract —Cardiovascular aging is associated with decreased endothelial vasoreactivity and prolonged diastolic relaxation. As diminished NO signaling contributes to age-associated endothelial dysfunction, we tested the hypothesis that impaired NO signaling or bioactivity also contributes to slowed ventricular relaxation with age. Accordingly, we measured myocardial NO synthase (NOS) enzyme activity, protein abundance, and cGMP production in old (22 to 25 months) and young adult (4 to 7 months) male Wistar rats. Both NOS3 protein abundance and calcium-dependent NOS activity were elevated in old compared with young adult hearts (7.2±1.1 versus 4.2±0.6 pmol/mg protein, respectively, P =0.03). However, NOS activity and protein abundance were similar in isolated myocytes, indicating that endothelial NOS likely explains the age difference. Cardiac effluent cGMP (enzyme immunoassay) was 4.8-fold higher (1794±373 fmol/min per mg heart tissue) in older versus younger hearts ( P =0.003). To assess NO pathway responsiveness, we administered the NOS substrate l-arginine (100 μm) to isolated perfused rat hearts. Baseline isovolumic relaxation (τ) was prolonged in old (42.9±2.5 ms, n=16) versus young hearts (36.0±1.9 ms, n=11, P =0.03). l-Arginine decreased τ ( P P H -[1,2,4]oxadiazolo-[4,3,- a ]quinoxalin-1-one (n=7, P
Quality of Urban Life Studies: An Overview and Implications for Environment-Behaviour Research

Abstract The growth of urban areas presents a challenge for local governments around the world. While the challenge is particularly formidable to policy makers and planners, it offers opportunities for environment-behaviour researchers to contribute to the resolution of urban problems.. Studies focusing on the quality of urban life (QOUL) offer such opportunities. The paper first presents an overview of QOUL studies. It then describes a number of conceptual models used to test relationships between objective urban conditions and QOUL. Finally, the models are elaborated so as to illustrate the manner in which environment-behaviour research can be conducted to inform urban policy, planning, and design.
The Countermanding Task Revisited: Fast Stimulus Detection Is a Key Determinant of Psychophysical Performance

The countermanding task is a standard method for assessing cognitive/inhibitory control over action and for investigating its neural correlates. In it, the subject plans a movement and either executes it, if no further instruction is given, or attempts to prevent it, if a stop signal is shown. Through various experimental manipulations, many studies have sought to characterize the inhibitory mechanisms thought to be at work in the task, typically using an inferred, model-dependent metric called the stop-signal reaction time. This approach has consistently overlooked the impact of perceptual evaluation on performance. Through analytical work and computer simulations, here we show that psychophysical performance in the task can be easily understood as the result of an ongoing motor plan that is modified (decelerated) by the outcome of a rapid sensory detection process. Notably, no specific assumptions about hypothetical inhibitory mechanisms are needed. This modeling framework achieves four things: (1) it replicates and reconciles behavioral results in numerous variants of the countermanding task; (2) it provides a new, objective metric for characterizing task performance that is more effective than the stop-signal reaction time; (3) it shows that the time window over which detection of a high-visibility stimulus effectively occurs is extremely short (∼20 ms); and (4) it indicates that modulating neuronal latencies and the buildup rates of developing motor plans are two key neural mechanisms for controlling action. The results suggest that manipulations of the countermanding task often cause changes in perceptual detection processes, and not necessarily in inhibition.
Experience with the virtual notebook system: abstraction in hypertext

The Virtual Notebook System (VNS) is a distributed collaborative hypertext system that has made a successful transition from research prototype to commercial product. Experience in developing and deploying the VNS in diverse settings including biomedical research, undergraduate education, and collaborative system prototyping has developed insight into the use of systems for computer-supported cooperative work (CSCW). This paper provides a brief overview of the VNS, discusses some of its strengths and weaknesses with respect to collaboration, and draws some conclusions about the impact of metaphor and extensibility on the collaborative process.
Greenhouse gas emissions: how to manage what cannot be measured

The bioethical metaphor The Tragedy of the Commons shows how individual interests can lead to overexploitation of a shared resource [1]. In the example of a communal village pasture, the villagers ...
Properties of the human cone system electroretinogram during light adaptation.

Changes in the response characteristics of the flash electroretinogram (ERG) of the human cone system were studied during the time course of adaptation to a cone-isolating ganzfeld background. During light adaptation, the amplitudes of the b- and i-waves increased, while the implicit time of the b-wave decreased. The amplitude of the a-wave and the implicit times of the a- and i -waves did not change systematically during light adaptation. Luminance-response functions for b-wave amplitude were obtained at discrete times following background onset and were analyzed using the hyperbolic equation R/Rmax= Ln/(Ln+ Kn). The increase in b-wave amplitude was characterized by increases in Rmax, K, and n. The decrease in b-wave implicit time was of a similar magnitude at all flash luminances. The amplitude increase of the i-wave only occurred at moderate flash luminances. The results provide a basis for optimizing the clinical recording of cone-isolated single-flash ERGs.
CD19-negative B-lymphoblastic leukemia associated with hypercalcemia, lytic bone lesions and aleukemic presentation

B lymphoblastic leukemia (B-ALL) is virtually always positive for the B-cell antigens CD19, CD79a and CD22. None are specific in determining lineage, but expression of a combination of these marker...
Design of manufacturing cells in the presence of alternative cell locations and material transporters

AbstractThis paper addresses two significant issues in the design of cellular manufacturing (CM) systems: (i) the availability of alternative locations for a cell, and (ii) the use of alternative routes to move part loads between cells when the capacity of the material transporter (MT) employed is limited. In addition, several other important factors in the design of CM systems including machine capacity limitations, batches of part demands, non-consecutive operations of parts, and maximum number of machines assigned to a cell are considered. A nonlinear programming model, comprised of binary and general integer variables, is formulated for the research problem. A higher-level heuristic solution algorithm based upon a concept known as ‘tabu search’ is presented for solving industry-size problems. Six different versions of the heuristic are developed to investigate the impact of long-term memory and the use of fixed versus variable tabu-list sizes. Explicit method-based techniques are developed to convert ...
SYNTHESIS OF MONODISPERSED IRON OXIDE PARTICLES BY A LARGE-SCALE MICROWAVE REACTOR

Well-defined mondispersed iron oxide particles can be synthesized in conventional hydrolysis approaches, but the synthesis generally takes two to seven days. Microwave hydrothermal approaches offer the possibility of significantly reducing synthesis time. This work demonstrates the feasibility of microwave synthesis in large scale. The batch size was 5 L, and the holding time was two hours. The crystallinity of the powders and the morphology and the monodispersity of the synthesized particles were comparable to those produced from conventional approaches. The particle size was in the nanosize range. The results indicated that for synthesis of monodispersed Fe2O3 nanopowders, it is possible to achieve the production rate of a 2.1 m3 conventional reactor with a 5 L microwave accelerated reactor.
Changes in brain norepinephrine associated with sensitization to d-amphetamine.

Pretreatment of B6AF1/J mice with d-amphetamine HCl 10 mg/kg, twice daily for 5 days, produced a 4-fold increase in the running response to a test dose of 5 mg/kg amphetamine. Amphetamine pretreatment decreased whole-brain norepinephrine levels to 50% of control values and whole-brain dopamine to 85%. The test dose of 5 mg/kg amphetamine lowered whole brain norepinephrine levels of control mice from 0.50 μg/g to 0.28 μg/g in 2 h. In amphetamine-pretreated mice, this injection caused an increase in whole-brain norepinephrine levels from 0.22 μg/g to 0.55 μg/g at 30 min, followed by a decrease to 0.22 μg/g at 60 min. No change in whole brain dopamine levels was observed in either group. Amphetamine sensitization and norepinephrine depletion were still evident 25 days after pretreatment. No cross sensitization to morphine or cocaine was observed. Reserpine pretreatment resulted in a 3-fold increase in locomotor activity following injection of d-amphetamine, 5 mg/kg. No sensitization or changes in catecholamine levels were observed in amphetamine-treated A/J mice. These results suggest that the sensitization produced by amphetamine pretreatment may be related to the depletion of brain norepinephrine.
Evolutionary relationships of superoxide dismutases and glutamine synthetases from marine species of Alteromonas, Oceanospirillum, Pseudomonas and Deleya

Evolutionary relationships among marine species assigned to the genera Alteromonas, Oceanospirillum, Pseudomonas, and Alcaligenes were determined by an immunological study of their Fe-containing superoxide dismutases (FeSOD) and glutamine synthetases (GS), two enzymes with differentially conserved amino acid sequences which are useful for determining intermediate and distant relationships, respectively. Five reference antisera were prepared against the FeSODs from Alteromonas macleodii, A. haloplanktis, Oceanospirillum commune, Pseudomonas stanieri, and Deleya pacifica. For GS, a previously prepared antiserum to the enzyme from Escherichia coli was employed. Amino acid sequence similarities for both enzymes were determined by the quantitative microcomplement fixation technique and the Ouchterlony double diffusion procedure. Six evolutionary groups were detected by FeSOD sequence similarities: three subgroups within the genus Alteromonas, the genera Oceanospirillum and Pseudomonas, and a new genus, Deleya (to accommodate marine Alcaligenes). Only four groupings were delineated by the GS data: the latter three genera and one group composed of all the species of Alteromonas. Evidence that all of these subgroups are derived from the evolutionary lineage defined by the purple sulfur photosynthetic bacteria is presented.
Late Neogene paleoceanography of the North Pacific DSDP Sites 173, 310, and 296

Abstract Major paleoclimatic/paleoceanographic fluctuations across the mid-latitudes of the North Pacific have been identified based on quantitative analysis of temperature sensitive planktonic foraminiferal biofacies at DSDP Sites 296, 310, and 173. In the marginal Northeast Pacific DSDP Site 173 temperature oscillations within the California Current System are marked by alternating cool and transitional faunal assemblages; cool paleowater masses are represented by high frequencies of predominantly sinistrally coiling Neogloboquadrina pachyderma and transitional water masses by high frequencies in the species of Globigerina and Globigerinita associated with predominantly dextrally coiling N. pachyderma . In the marginal Northwest Pacific DSDP Site 296 temperature oscillations within the Kuroshio Current System are characterized by alternating subtropical and transitional faunal assemblages. High abundance in temperate species of Globorotalia represent subtropical water masses; high frequencies in the species of Globigerina and Globigerinita represent transitional water masses. In the Central North Pacific cool, transitional, and subtropical assemblages are present permitting paleoclimatic/paleoceanographic correlation with the Northeast Pacific Site 173 based on frequency distribution of N. pachyderma and the Globigerina-Globigerinita group, and with the Northwest Pacific based on the Globorotalia and the Globigerina-Globigerinita groups. This paleoclimatic interpretation is supported by oxygen isotope studies of DSDP Site 310, and the Equatorial Pacific. A comparison of the quantitative distribution of temperate species of Globorotalia at DSDP Sites 310 and 296 suggests that paleoclimatic interpretation is not seriously complicated by calcium carbonate dissolution.
A procedure for regional lake water clarity assessment using Landsat multispectral data

Although previous investigations have demonstrated reliable empirical relationships between satellite data and nearly contemporaneous ground observations, satellite imagery has not been incorporated into routine lake monitoring programs. This paper focuses on key issues involved in applying satellite imagery to the regional assessment of lake clarity. Ten Landsat Thematic Mapper (TM) images and four Multispectral Scanner (MSS) images of the Twin Cities Metropolitan Area (TCMA) spanning 25 years (1973–1998) were analyzed. Based on this analysis, recommendations are made for a Landsat-based procedure for water clarity assessment. Closeness of fit (r2 values) of regression models between satellite brightness data and measured Secchi disk transparency (SDT) decreased with increasing size of the time window between image collection and ground observation of SDT. Use of SDT data collected within ±1 day of the image date is recommended, but where SDT data are limited, windows up to ±7 days yield reasonable results, especially in late summer when water clarity is relatively constant. Average brightness data from at least nine pixels in the deep open area of a lake should be used to predict lake clarity, but the accuracy of predicted SDT did not improve much as the number of pixels in the area of interest (AOI) increased above this value. A three-coefficient regression model using the TM1/TM3 ratio and TM1 was a consistent and reliable predictor of SDT (r2 values of .7–.8). A similar relationship involving the MSS1/MSS2 ratio and MSS1 was a reasonable predictor of SDT for MSS data. Efforts to produce a standard prediction equation for SDT applicable to images collected on different dates were not successful, but a simple regression procedure to account for differences in atmospheric conditions among image collection dates substantially decreased the range of coefficients in the regression model.
Orientation and locus of tropic photoreceptor molecules in spores of Botrytis and Osmunda.

Study of the tropic responses of Botrytis cinerea and Osmunda cinnamomea spores to blue light shows the photoreceptor molecules to be highly dichroic and oriented: in Botrytis their axes of maximum absorption lie perpendicular to the nearby cell surface; in Osmunda , parallel. The chief evidence lies in a comparison of their responses to plane polarized light—both germinate parallel to the vibration planes (defined by the axis of vibration of the electric vector and the axis of light propagation)—with those to partial illumination with unpolarized light: Botrytis grows from its brighter part; Osmunda , from its darker. The degree of orientation produced by polarized light corresponds, at high intensities, to that produced by the imposition of such large (about 100 per cent) intensity differences across a cell as to preclude all alternatives to oriented dichroic receptors. The photoreceptors of the Botrytis spore lie within the cell wall9s inner half. The chief evidence lies in the component of its tropic responses to polarized light within the vibration plane: germination peaks about 10° off the vibration axis. This deviation arises from focusing which is effective only in the wall9s inner half. At high intensities, anomalies appear in Botrytis which are interpreted as "centering," i.e ., a tendency toward growth from the center of two or more equally illuminated points of a cell rather than from one of them.
Positive DNA supercoiling generates a chromatin conformation characteristic of highly active genes

Abstract During transcription, positive DNA supercoils generated ahead of RNA polymerase could theoretically uncoil the negative DNA supercoils associated with nucleosomes and thereby decondense the chromatin fiber in preparation for RNA polymerase passage. Here we examine the effect of positive DNA supercoiling on the structure of yeast 2-microns minichromosomes. We utilized a conditional topoisomerase mutant expressing Escherichia coli topoisomerase I to convert the DNA supercoiling state from negative to positive in vivo. Minichromosomes containing positively supercoiled DNA exhibited a striking increase in DNase I sensitivity. They also displayed additional micrococcal nuclease cleavage sites but yielded nearly typical nucleosomal ladders after extensive digestion. Upon in vitro relaxation with eukaryotic topoisomerase I, the minichromosomes remained DNase I sensitive but were converted to negative DNA supercoiling with a slightly increased linking number compared to typical minichromosomes, thus indicating the presence of bound histones. Therefore, positive DNA supercoiling provides a mechanism for generating, but is not required for maintaining, a conformation in chromatin characteristic of highly transcribed genes.
Enhanced Conformational Sampling of M2 Muscarinic Acetylcholine Receptor for Designing Selective Allosteric Drugs

Muscarinic acetylcholine receptors are members of the superfamily of G-protein coupled receptors (GPCRs) and play critical roles in both the central and parasympathetic nervous systems. They are important drug targets for the treatment of a spectrum of diseases including abnormal heart rate, asthma, chronic obstructive pulmonary disease, Alzheimer's disease, Parkinson's disease and schizophrenia. Enhanced conformational sampling of M2 muscarinic receptor is achieved via accelerated molecular dynamics (aMD) simulations. The simulation output structures are clustered into representative conformers that are structurally distinct from each other. Potential allosteric binding sites are then identified by mapping the surface of the receptor conformers. This enables virtual screening of chemical compounds against the allosteric binding sites to discover receptor-selective drugs.
Anastomosis of biliary tissue with high-frequency electrical diathermy.

Laser tissue fusion results from the conversion of light to thermal energy, creating tissue heating and protein denaturation. Accurately controlled tissue heating from smaller, less expensive, non-laser sources should be able to duplicate the fusion or welding of tissues, which has been demonstrated with a variety of lasers. We examined the capability of high-frequency electrical diathermy to create effective tissue fusion with limited collateral thermal damage. Using an electrical diathermy device with up to 14 W output power at 13.56 MHz, the cystic ducts of freshly harvested canine gallbladders were fused shut. Immediately after closure of the cystic ducts, bursting pressure was determined. Welding time was approximately 60 s. Mean bursting strengths immediately after closure were 207 mm Hg (±94.3) in air (n=10) and 202 mm Hg (±44.7) under water immersion (n=9). Histologic sectioning revealed a full-thickness denaturation of collagen fibers with fusion. Our preliminary investigations suggest that high-frequency electrical diathermy may provide practical advantages for fusion of biliary tissues when compared with conventional suture closure and laser fusion.
Simulation study of a robotics-based method for on-orbit identification of spacecraft inertia properties

This paper presents the results of a simulation based study of a method for identifying the inertia parameters of a spacecraft on orbit. The method makes use of an onboard robotic arm to change the inertia distribution of the spacecraft system. As the result of the inertia redistribution, the velocity of the spacecraft system changes correspondingly. Since the velocity change is measurable and the inertia change of the robotic arm is precisely computable, the inertia parameters of the spacecraft body become the only unknown in the momentum equations and hence, can be identified from the momentum equations of the spacecraft system. To treat the problem as a linear identification problem, the problem has to be solved in two steps. The first step is to identify the mass and mass center of the spacecraft; and the second step is to identify the inertia tensor of the spacecraft. The advantages of this method are: 1) it does not consume fuel because the whole onboard mechanical subsystem involved is energized by solar power; 2) it requires measuring steady-state velocities only, but not acceleration and force; 3) it is not affected by any internal energy dissipation, which is very difficult to predict otherwise. The paper investigates the sensitivity of the method with respect to different arm/spacecraft mass ratios, arm motion trajectories, and velocity errors. The possible extension of the method by using a pair of two degrees of freedom solar panel mechanisms instead of a robotic arm is also discussed.
Evidence for Radical-Mediated Catalysis by HppE: A Study Using Cyclopropyl and Methylenecyclopropyl Substrate Analogues

(S)-2-Hydroxypropylphosphonic acid epoxidase (HppE) is an unusual mononuclear iron enzyme that catalyzes the oxidative epoxidation of (S)-2-hydroxypropylphosphonic acid ((S)-HPP) in the biosynthesis of the antibiotic fosfomycin. HppE also recognizes (R)-2-hydroxypropylphosphonic acid ((R)-HPP) as a substrate and converts it to 2-oxo-propylphosphonic acid. To probe the mechanisms of these HppE-catalyzed oxidations, cyclopropyl- and methylenecyclopropyl-containing compounds were synthesized and studied as radical clock substrate analogues. Enzymatic assays indicated that the (S)- and (R)-isomers of the cyclopropyl-containing analogues were efficiently converted to epoxide and ketone products by HppE, respectively. In contrast, the ultrafast methylenecyclopropyl-containing probe inactivated HppE, consistent with a rapid radical-triggered ring-opening process that leads to enzyme inactivation. Taken together, these findings provide, for the first time, experimental evidence for the involvement of a C2-centered radical intermediate with a lifetime on the order of nanoseconds in the HppE-catalyzed oxidation of (R)-HPP.
Negative Agenda Control and the Conservative Coalition in the U.S. House

While it is widely believed that a “conservative coalition” of Southern Democrats and Republicans sometimes formed on floor votes in the mid-twentieth-century House to block liberal policy initiatives, a fully fleshed-out picture of what the coalition was and how it operated is lacking. In this article, we investigate whether the conservative coalition wielded negative agenda control, that is, whether it used positions of power in the House to block bills from floor consideration that would have harmed a majority of its members. We find that the likelihood that the conservative coalition was rolled increased significantly after the Rules Committee packing in 1961—especially for bills that came from standing committees chaired by nonsoutherners. These results are consistent with the notion that Rules systematically protected the conservative coalition from unfavorable floor votes and that southern committee chairs continued to offer some blocking power after the Rules packing.
Using Race in Clinical Research to Develop Tailored Medications Is the FDA Encouraging Discrimination or Eliminating Traditional Disparities in Health Care for African Americans

Is there a useful purpose for race-based pharmaceutical trials? The answer to that question, more often than not, will depend on one's definition of race. “African Americans face the health care sy...
Selective Domain Stabilization as a Strategy to Reduce Fusion Protein Aggregation

ABSTRACT: A human serum albumin–human growth hormone (HSA–hGH) fusion protein was used as a model to understand the contributions of individual domains to the aggregation behavior of the overall fusion protein. Aggregation of HSA–hGH was studied at two different pH conditions, pH 5 and pH 7. Conformational stability of the HSA domain was modulated by addition of octanoic acid, a binding ligand. Conformational stability of the fusion protein and the HSA domain were determined from experimentally measured values for free energies of unfolding (Δ G unf ) with midpoint of apparent unfolding temperatures ( T m ) used as surrogate in some cases. Apparent T m s of both HSA and HSA–hGH were increased by octanoic acid binding. Osmotic second virial coefficients were measured to monitor protein–protein interactions in solution. Reductions in rates of aggregation were observed under solution conditions that increased protein–protein repulsive interactions even when no changes in conformational stability were detected. The results indicate that colloidal instabilities are responsible for HSA–hGH aggregation and that conformational stability of the HSA domain does not play a dominant role in the aggregation of HSA–hGH.
Guidelines for the development of a computer scheme to identify chromatographic peaks

Abstract In the development of a computer scheme to identify chromatographic peaks, decision-making algorithms must be constrained to rely o a reasonably limited body of data. Therefore, a procedure for normalizing the retention data to enhance their reliability is desired. the dual-reference peak method of normalization using multiple sets of reference peaks is shown to have the greatest general utility. A method of establishing the optimal location of reference peaks is presented. The expected degree of uncertainty in the normalized elution data is discussed.
Minimal covers revisited: correct and efficient algorithms

In [1] Nummenmaa and Tanisch show that the algorithm in [2] for computing minimal covers is incorrect even though it purports to correct the algorithms in [3-6]. As they illustrate with F = { A B → C}, the algorithm in [2] allows B to be eliminated as an extraneous attribute since the dependency AB → C is implied by A → C using augmentation. Thus F is replaced by F′ = [A → C], which is clearly not equivalent to F. The problematic step of the algorithm in [2] that allows this to occur is Consider each dependency X → A in some order. If Z is a subset of X such that F is contained in the closure of (F - {X → A}) ∪ {Z → A], then immediately replace X → A by Z → A in F. This step continues until no left side of any dependency in F can be reduced
Elementary Organizational Structures and Young Adolescents' Self-Concept and Classroom Environment Perceptions Across the Transition to Middle School

Abstract Transitions can be difficult at any age; however, the move from elementary school to middle school, coupled with the onset of adolescence, is often associated with a myriad of psychological and academic declines. One strategy currently used to “ready” elementary students for middle school is a departmentalized organizational structure. The purpose of this study was to investigate young adolescents' self-concept and classroom environment perceptions as they transitioned from two different elementary organizational structures into one middle school. Data were collected from 125 fifth-grade students who participated in a middle school transition program. Findings suggest that participants' perceptions of self-concept and classroom climate did not differ prior to or after the transition to middle school, based on the elementary organizational structure they experienced. However, time effects suggest that students' self-concept did significantly increase across the transition to middle school, while t...
Classroom Treatment of Psychotic Children: Specificity of Responses to Operative Contingencies

Behavior modification procedures were employed to treat four psychotic children in a classroom setting. Four treatment phases (baseline, a teacher-attention multiple baseline, reversal, and token reinforcement multiple baseline were utilized) and extensive recordings of teacher and pupil behavior were taken. All categories of inappropriate student behavior decreased, and appropriate student behavior increased during treatment. But no multiple baseline effects within each treatment and no reversal effects were observed. Teacher behavior showed an improvement over baseline, but no reversal of teacher behavior occurred during the reversal condition. The teacher did not discriminate among inappropriate student behaviors within treatment as demanded by the multiple baseline design. This accounted for the absence of any reversal and within-treatment multiple baseline effects on student behavior. Appropriate student behavior did increase from baseline to the teacher-attention phase and from teacher-attention to ...
Analytic Ordering for Theoretical Purposes

This article discusses why and how to make explicit the linkages between interaction and conditions affecting both the interaction and its consequences. The discussion aims at (a) extending the ran...
Uniaxial incommensurate phases at the Au(111) electrode

Abstract The structure of the Au(111) electrode has been investigated using surface X-ray scattering (SXS) in a variety of electrolytes. Although the underlying gold layers have hexagonal symmetry, the top most gold layer forms a rectangular, uniaxial incommensurate (px √3) structure in the absence of specific adsorption. The (px √3) structure is also observed for bismuth and iodine adlayers, where p continuously changes with potential (electrocompressibility).
Electrical and Magnetic Properties of Some Mixed LnIIIOxN1-x Phases

Some pseudobinary and pseudoternary oxidenitrides (CeN-CeO2; LaN-Ln2O3; CeN-Ln2O3, Ln = La, Y; and YN-Ln2O3, Ln = La, Lu, Y, Sc) were prepared in Ta, Nb, or Mo containers at temperatures between 1500 and 1800°C and characterized by X-ray powder diffraction. Electrical and magnetic properties of two oxidenitrides, LaO0.31N0.69(I) and LaO0.45N0.55(II), were determined over the temperature range 2-300 K. Both are weakly paramagnetic and metallic. Room temperature (300 K) resistivities for I and II are 4.8 × 10-3 and 5.9 × 10-5 Ω cm, respectively. As the temperature is lowered, resistivities of LaO3N1-x initially decrease linearly.
ROMHD and ROMLD

An embedded read-only memory architecture with a complementary cell and two interchangeable power/performance design points is described. This article focuses on the novel features of 0.13-/spl mu/m embedded, compilable read-only memory (ROM). A complementary array cell that increases and maintains signal margins across array sizes despite the ever-increasing capacitive coupling effects and lower voltages of each succeeding technology generation is described here along with a new architecture that allows a customer to switch between two different power/performance design points while only changing the metal wiring in the ROM via a compiler. Hardware data is presented that illustrates the success of the array design and the difference between the two power/performance design points.
Statistical implications of using moving violations to determine crash responsibility in young driver crashes

Traditional methods for determining crash responsibility - most commonly moving violation citations - may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010-2011) that involved a New Jersey driver <21 years old (79,485 drivers<age 21, 61,355 drivers ≥age 21). For each driver, crash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups-younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification of driver actions may yield more accurate characterizations of at-fault drivers.
Indices of Cardiac Status

A review of various indices of cardiac status and ventricular performance is presented. Different physical modalities used to measure cardiovascular characteristics are discussed and the methods of elucidating quantitative indices from these measurements are described. Emphasis is placed on cardiac mechanics and a force-velocity-length description of the left ventricle. Finally, indices are derived from simple hemodynamic measurements when these are combined with equivalent network and dynamic shell models of the heart.
Microwave Sintering of Ceramics, Composites and Metallic Materials, and Melting of Glasses

Though microwaves have been in use for many applications for over 60 years, their application in ceramic processing involving synthesis, sintering, melting, joining, surface modifications, etc, has developed only in the last twenty years. Microwave materials processing is recognized for many advantages, namely, substantial reduction in cycle time resulting in large energy savings, selective and volumetric heating, providing fine microstructures, improved mechanical properties, and eco-friendliness. In the last two decades, various researchers have worked with a variety of traditional and advanced ceramics such as alumina, zirconia. hydroxyapatites, transparent ceramics, electroceramics, ceramic superconductors, glass-ceramics, non-oxide ceramics including Si3N4, AIN, SiC and WC/Co, etc. In all of these materials, substantial improvements in their properties over conventional products, as well as enhancements in the diffusion and reaction kinetics, were reported. Recently, microwave melting of glasses has ...
Dynamics of the Aboveground and Belowground Structure of the Seagrass Halodule wrightii

Dynamics of the aboveground and belowground structure of the seagrass Halodule wrighti~ (Asherson) Asherson was studied from April 1984 to March 1985. Seasonality of plant structure was evident, with the highest abundance of short shoots and belowground structures occuning in June. An Inverse relationship between root and rhizome biomass was observed with the former reachng a n~aximum in February and March, while the latter attained highest values in July and August. The number of short shoots produced per branch varied over the year, ranging from a low of 0.4 to a high of 1.5. The ratio number of branches/rhzome length was relatively constant over the study period with a slight decrease in summer. Examination of underground architecture revealed that, in contrast to plants that have highly branched underground structure, high belowground complexity of H. wrightfi is achleved by a dense intermingling of many plants with unidirectional rhizomes.
Shakespeare and the feminist actor

(1985). Shakespeare and the feminist actor. Women & Performance: a journal of feminist theory: Vol. 2, No. 2, pp. 18-26.
Refined structure of the human histocompatibility antigen HLA-A2 at 2.6 Å resolution☆

The three-dimensional structure of the human histocompatibility antigen HLA-A2 was determined at 3.5 A resolution by a combination of isomorphous replacement and iterative real-space averaging of two crystal forms. The monoclinic crystal form has now been refined by least-squares methods to an R-factor of 0.169 for data from 6 to 2.6 A resolution. A superposition of the structurally similar domains found in the heterodimer, α_1 onto α_2 and α_3 onto β_2m, as well as the latter pair onto the ancestrally related immunoglobulin constant domain, reveals that differences are mainly in the turn regions. Structural features of the α_1 and α_2 domains, such as conserved salt-bridges that contribute to stability, specific loops that form contacts with other domains, and the antigen-binding groove formed from two adjacent helical regions on top of an eight-stranded β-sheet, are analyzed. The interfaces between the domains, especially those between β_2m and the HLA heavy chain presumably involved in β_2m exchange and heterodimer assembly, are described in detail. A detailed examination of the binding groove confirms that the solvent-accessible amino acid side-chains that are most polymorphic in mouse and human alleles fill up the central and widest portion of the binding groove, while conserved side-chains are clustered at the narrower ends of the groove. Six pockets or sub-sites in the antigen-binding groove, of diverse shape and composition, appear suited for binding side-chains from antigenic peptides. Three pockets contain predominantly non-polar atoms; but others, especially those at the extreme ends of the groove, have clusters of polar atoms in close proximity to the “extra” electron density in the binding site. A possible role for β_2m in stabilizing permissible peptide complexes during folding and assembly is presented.
Senescent Cells: A Novel Therapeutic Target for Aging and Age-Related Diseases

Aging is the main risk factor for most chronic diseases, disabilities, and declining health. It has been proposed that senescent cells--damaged cells that have lost the ability to divide--drive the deterioration that underlies aging and age-related diseases. However, definitive evidence for this relationship has been lacking. The use of a progeroid mouse model (which expresses low amounts of the mitotic checkpoint protein BubR1) has been instrumental in demonstrating that p16(Ink4a)-positive senescent cells drive age-related pathologies and that selective elimination of these cells can prevent or delay age-related deterioration. These studies identify senescent cells as potential therapeutic targets in the treatment of aging and age-related diseases. Here, we describe how senescent cells develop, the experimental evidence that causally implicates senescent cells in age-related dysfunction, the chronic diseases and disorders that are characterized by the accumulation of senescent cells at sites of pathology, and the therapeutic approaches that could specifically target senescent cells.
Quadriceps and Hamstrings Muscle Dysfunction after Total Knee Arthroplasty

Background/rationale Although TKA reliably reduces pain from knee osteoarthritis, full recovery of muscle strength and physical function to normal levels is rare. We presumed that a better understanding of acute changes in hamstrings and quadriceps muscle performance would allow us to enhance early rehabilitation after TKA and improve long-term function.
Plasma membrane ion channel regulation during abscisic acid-induced closing of stomata

The plant growth regulator abscisic acid triggers closing of stomata in the leaf epidermis in response to water stress. Recent tracer flux studies, patch-clamp studies, fluorometric Ca $^{2+}$ measurements and microelectrode experiments have provided insight into primary transduction mechanisms by which abscisic acid causes stomatal closing. Data show that abscisic acid activates non-selective Ca $^{2+}$ -permeable ion channels in the plasma membrane of guard cells. The resulting elevation in the free Ca $^{2+}$ concentration in the cytosol of guard cells, and the resulting membrane depolarization as well as other unidentified Ca $^{2+}$ -independent mechanisms are suggested to contribute to activation of voltage- and second messenger-dependent anion channels and outward rectifying K $^{+}$ channels. Recent data suggest the involvement of two types of anion channels in the regulation of stomatal movements, which provide highly distinct mechanisms for anion efflux and depolarization. A novely characterized `S-type' anion channel is likely to provide a key mechanism for long-term depolarization and sustained anion efflux during closing of stomata. Patch-clamp studies have revealed the presence of a network of K $^{+}$ , anion and non-selective Ca $^{2+}$ -permeable channels in the plasma membrane of a higher plant cell. The integrated control of these guard cell ion channels by abscisic acid can provide control over K $^{+}$ and anion efflux required for stomatal closing.
Body size dissatisfaction and avoidance behavior: How gender, age, ethnicity, and relative clothing size predict what some won't try

Sixty-eight percent of U.S. adults are overweight/obese, and this epidemic has physical, psychosocial, and behavioral consequences. An internet sample of adults (N = 2997) perceiving themselves as larger than ideal in clothing size reported their body mass index (BMI), relative clothing size (RS; discrepancy between current and ideal size), and avoidance behaviors. Exploratory factor analysis of 10 avoid-ance items produced social avoidance and body display avoidance factors. A relative importance analysis revealed RS as a better predictor than BMI for avoidance. A hierarchical multivariate analysis of covariance found RS to predict both avoidance constructs. The relationship between RS and both avoidance con-structs was stronger for women than men, and for younger as compared to older participants. Caucasians reported more body display avoidance than African Americans. This suggests that personal dissatisfac-tion with body size may deter involvement in varied life events and that women are especially avoidant of activities that entail displaying their bodies.
The effects of vitamin B6 deficiency on the bone marrow of the rat1

Bone marrow from adult rats fed a vitamin B6 deficient diet for two weeks was found to have reduced numbers of neutrophils, erythroid cells and small lymphocytes. The numbers of transitional cells were not reduced. Since the small lymphocyte population in the bone marrow consists of B cells and null cells in approximately the same proportion, it was concluded that both cell types were reduced as a result of the deficiency. A complete recovery in the cellularity of the bone marrow was brought about by returning the vitamin B6 deficient animals to a normal diet for four weeks. Other effects of the two-week vitamin B6 deficient diet included a failure to gain weight, a decrease in thymus weight and a reduction in the numbers of white blood cells in the peripheral blood. All of these defects were corrected after the animals had been fed a normal diet for four weeks.
Three-dimensional spiral waves in an excitable reaction system: Initiation and dynamics of scroll rings and scroll ring pairs

We report experimental results on spiral and scroll waves in the 1,4-cyclohexanedione Belousov–Zhabotinsky reaction. The propagating concentration waves are detected by two-dimensional photometry and optical tomography. Wave pulses can disappear in front-to-front and front-to-back collisions. This anomaly causes the nucleation of vortices from collisions of three nonrotating waves. In three-dimensional systems, these vortices are scroll rings that rotate around initially circular filaments. Depending on reactant concentrations, the filaments shrink or expand indicating positive and negative filament tensions, respectively. Shrinkage results in vortex annihilation. Expansion is accompanied by filament buckling and bending, which is interpreted as developing Winfree turbulence. We also describe the initiation of scroll ring pairs in four-wave collisions. The two filaments are stacked on top of each other and their motion suggests filament repulsion.
Energy-efficient mobile robot exploration

Mobile robots can be used in many applications, including exploration in an unknown area. Robots usually carry limited energy so energy conservation is vital. This paper presents an approach for energy-efficient robot exploration. Our approach determines the next target for the robot to visit based upon orientation information. The robot plans the path between the current position to the next target in an energy-efficient way. Our method reduces repeated coverage, a common problem for most existing utility-based target selecting methods. We conduct simulations for both random and structured environments, and compare our method with a utility-based method that chooses the middle cell from the widest opening. Results show that our method can reduce energy consumption by 42% and traveling distance by 41%