cssi/SciSciGPT-SciSciNet huggingface dataset:
An Investigation of Commitment among Participants in an Extended Day Physical Activity Program

Abstract This study examined underserved youth participants' perceptions of commitment to an extended day physical activity program using Hellison's (1995) responsibility model. Seven participants ranging in age from 12 to 15 years participated in the study. Two personal interviews and a focus group interview were used to obtain participants' perceptions of program commitment. Results revealed that program organization, personal characteristics, development of interpersonal relationships, and the program environment influenced their program commitment. Participants described the nature of commitment in terms of program behavior, emotional involvement, and program history. While the type of activity was cited as a positive influence on program commitment, the specific activity could also serve as a barrier to program commitment. Implications for program development and future research are offered.
Welfare implications of reduced government subsidies to farm families: accounting for fringe benefits

In the past three decades, farm families have relied on government payments and off-farm income to reduce income risk and increase total household income. Studies have shown that, as the income effect dominates, government payments tend to reduce off-farm labor of farm operators and spouses. But that may not be true if one accounts for fringe benefits associated with off-farm employment. Additionally, with looming budget deficits and the possibility of a reduction in decoupled government payments, farm families may be facing an altered economic environment. Our study addresses this issue by examining the links between government farm program payments and the ever-important role of fringe benefits in the off-farm employment of farm couples. Results from farm-level data actually show that the marginal effect of government payments on hours worked off-farm will decrease in magnitude when accounting for fringe benefits, ceteris paribus. These results support the notion that farm households’ welfare loss stemming from reduced decoupled payments may be overstated when models exclude fringe benefits from the estimation of off-farm labor supply.
Peri-urban environments and community driven development: Chennai, India

Abstract This paper focuses on the transitional peripheral zone of a large Indian metropolis, and the inability of the public sector (i.e. urban local governments) there to provide the array of services necessary for the maintenance of a satisfactory quality of life due to the rapidity of population growth. This is explored in the specific context of waste management. Using a series of photographs, the problems in the peri-urban setting are revealed. The response of civil society organizations is illustrated in efforts to take control of this problem.
Log-Linear Models for Gene Association

We describe a class of log-linear models for the detection of interactions in high-dimensional genomic data. This class of models leads to a Bayesian model selection algorithm that can be applied to data that have been reduced to contingency tables using ranks of observations within subjects, and discretization of these ranks within gene/network components. Many normalization issues associated with the analysis of genomic data are thereby avoided. A prior density based on Ewens’ sampling distribution is used to restrict the number of interacting components assigned high posterior probability, and the calculation of posterior model probabilities is expedited by approximations based on the likelihood ratio statistic. Simulation studies are used to evaluate the efficiency of the resulting algorithm for known interaction structures. Finally, the algorithm is validated in a microarray study for which it was possible to obtain biological confirmation of detected interactions.
Electrostatic determinants of stability in parallel 3-stranded coiled coils.

The optimal positioning of salt-bridging interactions in a parallel α-helical homotrimeric coiled coil has been explored in a metal ion-assembled polypeptide trimer of 60 residues; arginine–glutamate pairs are more stabilizing than the corresponding lysine–glutamate pairs, and optimal stabilization is obtained with positively charged arginine residues at the c positions of the α-helical heptad and negatively charged glutamate residues at the e positions.
Simulation curriculum: a model curriculum in modeling and simulation: do we need it? can we do it?

An international debate on the need for a model curriculum for graduate programs in Modeling and Simulation (M&S) continues to grow. As the use of M&S continues to expand to new application areas, and its importance as a key enabling technology in the 21st century continues to be recognized, many questions are being asked by both universities and corporations concerning the proper basis and content for advanced studies in M&S.Corporations and government bodies are experiencing rising demands for new recruits with broad exposure to the concepts and methodologies of M&S and capable of contributing to the increasingly important M&S activities within the organization. Many recruiters are, however, frustrated in their efforts to define productive sources in US universities that meet these needs.
Triple mode-locking of Ar+ and dye lasers

Abstract We report a new technique of generating highly synchronous simultaneous pulse trains at three wavelengths, two of which are continuously tunable over a moderate range. A series of oscillographs shows the time-resolved Ar+ pulses and the effects of varying the two cavity lengths with respect to each other. Preliminary correlation measurements indicate low jitter.
Holocene dune formation at Ash Meadows National Wildlife Area, Nevada, USA

Small isolated dune fields in the northern Mojave Desert are important centers of biodiversity and archaeological occupation sites. Currently dunes at Ash Meadows, Nevada, are stabilized by vegetation and are experiencing erosion of their upwind margins, indicating a negative sediment budget. New OSL ages from dunes at Ash Meadows indicate continuous eolian accumulation from 1.5 to 0.8 ka, with further accumulation around 0.2 ka. Prior studies (e.g., Mehringer and Warren, 1976) indicate periods of dune accumulation prior to 3.3 ka; 1.9–1 ka; and after 0.9 ka. These periods of eolian accumulation are largely synchronous with those identified elsewhere in the Mojave Desert. The composition of the Ash Meadows dunes indicates their derivation from regional fluvial sources, most likely during periods when axial washes were active as a result of enhanced winter precipitation.
Repolarization of the presynaptic action potential and short-term synaptic plasticity in the chick ciliary ganglion.

Stimulation-induced increases in synaptic efficacy have been described as being composed of multiple independent processes that arise from the activation of distinct mechanisms at the presynaptic terminal. In the chick ciliary ganglion, four components of short-term synaptic plasticity have been described: F1 and F2 components of facilitation, augmentation, and potentiation. In the present study, intracellular recording from the presynaptic calyciform nerve terminal of the chick ciliary ganglion revealed that the late repolarization and afterhypolarization (AHP) phases of the presynaptic action potential are affected by repetitive stimulation and that the time course of these effects parallel that of facilitation. The effects of these changes in the presynaptic action potential time course on calcium influx were tested by using the recorded action potential waveforms as voltage command stimuli during whole-cell patch-clamp recordings from acutely isolated chick ciliary ganglion neurons. The "facilitated" action potential waveform (slowed repolarization, decreased AHP amplitude) evoked calcium current with slightly but significantly greater total calcium influx. Taken together, these results are consistent with the hypothesis that activity-dependent changes in the presynaptic action potential are one of several mechanisms contributing to the facilitation phase of stimulation-induced increases in transmitter release in this preparation.
Analysis of the stabilities of hexameric amyloid-β (1–42) models using Discrete Molecular Dynamics simulations

Abstract Amyloid-β (Aβ) oligomers appear to play a pivotal role in Alzheimer's disease. A 42 residue long alloform, Aβ42, is closely related to etiology of the disease. In vitro results show evidences of hexamers; however structures of these hexamers have not been resolved experimentally. Here, we use discrete molecular dynamics (DMD) to analyze long duration stabilities of Aβ42 hexamer models developed previously in our lab. The hydrophobic core of these models is a six-stranded β-barrel with 3-fold radial symmetry formed by residues 30–40. This core is shielded from water by residues 1–28. The nine models we analyzed differ by the relative positions of the core β-strands, and whether the other segments surrounding the core contain α helices or β-strands. A model of an annular protofibril composed of 36 Aβ peptides was also simulated. Results of these model simulations were compared with results of aggregation simulations that started from six well separated random coils of Aβ42 and with simulations of two known β-barrel structures. These results can be categorized into three groups: stable models with properties similar or superior to those of experimentally determined β-barrel proteins, aggregation-prone models, and an amorphous aggregate from random coils. Conformations at the end of the simulation for aggregation-prone models have exposed hydrophobic core with dangling β-strands on the surface. Hydrogen bond patterns within the β-barrel were a critical factor for stability of the β-barrel models. Aggregation-prone conformations imply that the association of these hexamers may be possible, which could lead to the formation of larger assemblies.
A biogeochemical mass balance of 210Po and 210Pb in an oligotrophic lake with seasonally anoxic hypolimnion

Abstract The mass balances of 210 Po and 210 Pb were determined for Bickford Pond, Massachusetts. Activities of these nuclides at various depths within the water column, in sediments, in streams flowing into and out of the lake and in precipitation were measured at approximately monthly intervals for a period of one year. Streamwater contained about 10 dpm/100 kg of 210 Pb, mostly filtrable and showed little variation with changing flow. 210 Pb in the streams is believed to be derived mostly from 222 Rn that enters groundwater via alpha-recoil from aquifer matrix materials. It is therefore not meteoric in origin and represents a local source to the lake. Surface inflow was equally important as precipitation as a source of 210 Pb to the lake. Only half of total 210 Pb input was trapped in sediments; the rest was lost from the lake as outflow. The 210 Pb removal times via scavenging and sedimentation both averaged close to 40 days and 210 Pb scavenging was almost an order of magnitude greater than that of 210 Po.
Appraisal of risks from nonoccupational exposure to chlorpyrifos.

The toxicological database for chlorpyrifos indicates that humans are not more sensitive than laboratory animals to the toxic effects. Although an oral dose of 1 mg/kg-day resulted in measurable levels of chlorpyrifos in the blood, daily dosing at this level from 9 days to 2 years did not affect brain acetylcholinesterase activity (AChE) in laboratory animals. Developmental toxicity did not occur at doses below maternal toxicity. Most nonoccupational illnesses resulting from entry into areas treated with chlorpyrifos likely stem from odor, rather than the ability of the organophosphate to inhibit AChE. Based on biological monitoring studies, chronic aggregate nonoccupational exposures to chlorpyrifos ranged from 0.0002 mg/kg-day (adults) to 0.0005 mg/kg-day (infants and small children)-1 order of magnitude less than exposures estimated by standard procedures. Other biological monitoring data indicated that cumulative exposure to all organophosphate pesticides ranged from 0.0003 mg/kg-day (adults) to 0.003 mg/kg-day (children). Considering all these factors, the risks of aggregate, nonoccupational exposure to chlorpyrifos have been overstated by more than a 1000-fold.
Alterations in renal cortical blood flow in infants and children with urinary tract infections.

Alterations in Renal Cortical Blood Flow in Infants and Children with Urinary Tract Infections
Physical aspects of the internal water relations of plant leaves

Relations between the water potential, osmotic potential, pressure potential, and relative water content have been derived on the basis of 2 simple assumptions. Measurements of these quantities were made on leaves of cotton, sunflower, pepper, and birdsfoot trefoil to test the validity of these relations. Within the precision of the data, the assumption that the osmotic potential is inversely proportional to the relative water content of the leaf was satisfied. The turgor pressure was not related to water content in a simple linear fashion but the data could be represented adequately by 2 straight-line segments. A marked change in the modulus of elasticity of the leaves occurs at a turgor pressure of about 2 bars, corresponding to a water potential of about -12 bars. The so-called permanent wilting phenomenon is explained in terms of the variation in elastic modulus. The major change in leaf dimensions with changing water content occurred in the leaf thickness with only a modest variation in the leaf area. 12 references, 7 figures, 1 table.
How the Pueblos became global: Colonial appropriations, resistance, and diversity in the North American Southwest

Theories of colonialism and modernity often present divergent ways of understanding how indigenous populations became global, yet there are several points of intersection. These points include: (1) the heterogeneity present within indigenous groups that led to varied experiences of colonialism, (2) the diversity in colonial programs, (3) how the colonized and the colonizers appropriated goods and labor from each other, and (4) the variable practices of indigenous resistance. These intersections are illustrated through a discussion of the Pueblos of the North American Southwest, from the late “precontact” period (ca. AD 1400) to the present.
A nonlinear characterization of stable invariant subspaces

A nonlinear characterization of stable invariant subspaces for an operator on Hilbert space is given. The characterization involves the solutions to a certain quadratic operator equation. The characterization is used to give information about the stability of certain invariant subspaces of an operator.
Preventing cascading failures in microgrids with one-sided support vector machines

Microgrids formed by a network of power sources and power consumers yield significant advantages over the conventional power grid including proximity of power consumption to power generation, distributed generation, resiliency against wide area blackouts and ease of incorporation of renewable energy sources. On the other hand, unlike the conventional grid, microgrids are compliant where a single load or a single generation unit can often form a significant fraction of the total generation capacity. Here large excursions from the nominal operating conditions are possible motivating the need for safety mechanisms which isolate power electronic equipment from damage. Breakers serve the purpose of protecting equipment from surge conditions by shutting off, for example, generation units. However in microgrids, a loss of a single generation unit can have catastrophic impact on the viability of the entire system. Here settings on breakers cannot be chosen too conservatively to protect the equipment at the expense of system viability or too liberally which will result in equipment damage. The ensuing problem of striking a suitable compromise tends to be combinatoric in nature due to numerous states of breakers which is further exacerbated by an uncertain load profile and nonlinear nature of system dynamics. In this article we provide a methodology to determine current thresholds and guard times, the time interval when current is allowed to exceed threshold value, for each inverter for fail-safe operation of microgrid. We employ a machine learning approach to address the problem where we first demonstrate that conventional support vector machine (SVM) methodology does not yield a satisfactory solution. We then develop a one-sided SVM method and generalize it to yield nonlinear support boundaries which captures the need for fail-safe operation against system blackouts while protecting equipment. A simulation engine is developed to model a real microgrid which is used to generate data for assessing and guiding our approach.
dc measurements of macroscopic quantum levels in a superconducting qubit structure with a time-ordered meter

dc measurements are made in a superconducting, persistent current qubit structure with a time-ordered meter. The persistent-current qubit has a double-well potential, with the two minima corresponding to magnetization states of opposite sign. Macroscopic resonant tunneling between the two wells is observed at values of energy bias that correspond to the positions of the calculated quantum levels. The magnetometer, a superconducting quantum interference device, detects the state of the qubit in a time-ordered fashion, measuring one state before the other. This results in a different meter output depending on the initial state, providing different signatures of the energy levels for each tunneling direction.
PCIRV--a mode of ventilation associated with problems

1990;98;520-a-520 Chest Stephan H. Boehm, Lindell K. Weaver, Thomas D. East and Alan H. Morris Problems PCIRV-A Mode of Ventilation Associated with http://chestjournal.chestpubs.org/content/98/2/520-a.citation can be found online on the World Wide Web at: The online version of this article, along with updated information and services ) ISSN:0012-3692 http://chestjournal.chestpubs.org/site/misc/reprints.xhtml ( without the prior written permission of the copyright holder. reserved. No part of this article or PDF may be reproduced or distributed Chest Physicians, 3300 Dundee Road, Northbrook, IL 60062. All rights of been published monthly since 1935. Copyright1990by the American College is the official journal of the American College of Chest Physicians. It has Chest
Erratum: The Implications of Research on Expertise for Curriculum and Pedagogy

The description of the 1993 study by Crandall and Getchell-Reiter contained an incorrect explanation of the methodology. During initial interviews with participants, researchers did not provide any guidance regarding the type of detail to provide. Therefore, the sentence reading “Interviewers emphasized the need for the nurses to be as specific as possible about assessment parameters, diagnostic cues, and clinical judgments that they used,” should be omitted. Educ Psychol Rev (2007) 19:111 DOI 10.1007/s10648-006-9041-0
Over- and Ectopic Expression of Wnt3 Causes Progressive Loss of Ameloblasts in Postnatal Mouse Incisor Teeth

Intercellular signaling is essential for the development of teeth during embryogenesis and in maintenance of the continuously growing incisor teeth in postnatal rodents. WNT intercellular signaling molecules have been implicated in the regulation of tooth development, and the Wnt3 gene shows specific expression in the enamel knot at the cap stage. We demonstrate here that Wnt3 also is expressed in specific epithelial cell layers in postnatal incisor teeth. To begin to delineate the functions of Wnt3 in developing and postnatal teeth, we determined the effects of over- and ectopic expression of Wnt3 in the tooth epithelium of mice carrying a keratin 14- Wnt3 transgene. Expression of the transgene caused a progressive loss of ameloblasts from postnatal lower incisor teeth. Loss of ameloblasts may be due to defective proliferation or differentiation of ameloblast precursors, progressive apoptosis of ameloblasts, or loss of ameloblast stem cells.
Thermodynamic and morphological studies of the solid-state transition in copolymers of vinylidene fluoride and trifluoroethylene

Copolymers of vinylidene fluoride and trifluroethylene are presently being considered for many piezoelectric applications. In contrast to the poly(vinylidene fluoride) homopolymer, a transition from the room temperature ferroelectric phase to a paraelectric phase has been observed in these copolymers. The temperature of this transition was determined by measuring the position of the endothermic peak observed in the differential scanning calorimeter. The rate of cooling from the paraelectric to ferroelectric phase was found to affect the temperature at which the transition occurred on subsequent heating. Changing the conditions under which molten polymer initially crystallized into the paraelectric phase had an even greater effect on the resultant transition temperature. In addition to the DSC studies, wide-angle x-ray measurements were performed on samples subjected to different thermal treatments. No significant differences were found in the x-ray scans of these copolymers.
Human sensory preconditioning in a flavor preference paradigm

This experiment adapted a sensory preconditioning (SPC) procedure using human participants to determine if conditioning (Cond) to one flavor (the conditioned flavor) will enhance liking for another flavor (the SPC flavor) associated with it prior to training. Participants in one of three groups (N=40 per group) consumed and rated plain or sweetened cherry and grape kool-aids in four phases. In baseline and SPC phase, ratings for a plain cherry, grape, and cherry-grape mixture were similar. In training, one flavor was sweetened (SPC+Cond and Cond Only groups) or unsweetened (SPC Only group) and ratings increased only for the flavor that was sweetened. In test, Group SPC+Cond rated the conditioned flavor and the SPC flavor as more liked and tasting sweeter. Group Cond Only rated only the conditioned flavor as more liked and tasting sweeter. Group SPC Only showed no change in ratings from baseline to test. These are the first data to show SPC learning using a flavor preference paradigm with human participants.
On assignment of fundamental vibrational modes of hypophosphite anion and its deuterated analogue

Abstract Results of ab initio and density functional theory calculations on the structure and vibrational frequencies of hypophosphite anion indicate earlier experimental assignments of the fundamental vibrational modes are correct while the recent reassignments of several modes proposed by Bickley et al. are inconsistent with the calculated results.
The distribution of strontium between coexisting silicate and carbonate liquids at elevated pressures and temperatures

Abstract Strontium is characteristically enriched in carbonatites and associated igneous rocks. Experiments between 600 and 800°C at 5 and 10 kb show that Sr fractionates strongly toward both liquid phases of a carbonate liquid-silicate liquid-solid assemblage, with the crystalline phases depleted in Sr. Considering that the alkalic igneous rocks associated with carbonatites are not significantly depleted in Sr compared with the carbonatites, it is concluded that these complexes are formed by a pair of immiscible magmas, rather than the carbonatites being late-stage fractionation products of the alkalic silicate magmas.
Rapid Covalent Ligation of Fluorescent Peptides to Water Solubilized Quantum Dots

Water solubilized nanoparticles such as CdSe−ZnS core−shell nanocrystals (quantum dots, QDs) have great potential in bioimaging and sensing applications due to their excellent photophysical properties. However, the efficient modification of QDs with complex biomolecules represents a significant challenge. Here, we describe a straightforward arylhydrazone approach for the chemoselective covalent modification of QDs that is compatible with neutral pH and micromolar concentrations of the peptide target. The kinetics of covalent modification can be monitored spectroscopically at 354 nm in the presence of the QD and average peptide/QD ratios from 2:1 to 11:1 were achieved with excellent control over the desired valency. These results suggest that aniline catalyzed hydrazone ligation has the potencial to provide a general method for the controlled assembly of a variety of nanoparticle-biomolecule hybrids.
KNOWLEDGE AND ATTITUDES ABOUT THE SEXUALITY OF OLDER ADULTS AMONG RETIREMENT HOME RESIDENTS

In this study I used a questionnaire to determine the knowledge and attitudes about the sexuality of older adults held by well elderly people living in an Iowa retirement home (n – 133); I compared their knowledge and attitude scores with test norms and with a comparison group of Iowa university students (n – 133). I also explored what demographic factors affected knowledge and attitude scores. General attitudes of both retirees and students toward the sexuality of the elderly were very positive, but their attitudes toward specific sexual behaviors were less positive. Retirement home residents had less knowledge and less positive attitudes about the sexuality of older adults than did university students. There was a correlation between greater knowledge and more positive attitudes. I conclude that older adults need more in‐depth education about their sexuality and sexual functioning.
Highly conductive and flexible nylon-6 nonwoven fiber mats formed using tungsten atomic layer deposition.

Low-temperature vapor-phase tungsten atomic layer deposition (ALD) using WF6 and dilute silane (SiH4, 2% in Ar) can yield highly conductive coatings on nylon-6 microfiber mats, producing flexible and supple nonwovens with conductivity of ∼1000 S/cm. We find that an alumina nucleation layer, reactant exposure, and deposition temperature all influence the rate of W mass uptake on 3D fibers, and film growth rate is calibrated using high surface area anodic aluminum oxide. Transmission electron microscopy (TEM) reveals highly conformal tungsten coatings on nylon fibers with complex “winged” cross-section. Using reactant gas “hold” sequences during the ALD process, we conclude that reactant species can transport readily to reactive sites throughout the fiber mat, consistent with conformal uniform coverage observed by TEM. The conductivity of 1000 S/cm for the W-coated nylon is much larger than found in other conductive nonwovens. We also find that the nylon mats maintain 90% of their conductivity after being f...
Olsalazine induced secretion in rabbit IIeal mucosa

Olsalazine has been observed to induce diarrhoea in 4.9% of patients. In vivo trials in rat ileum and colon suggest stimulation of secretion by olsalazine. The in vitro effect of olsalazine was examined on active anion secretion by rabbit distal ileum compared to sulphasalazine and 5-aminosalicylic acid (5-ASA). Rabbit terminal ileal strips were mounted in Ussing chambers, and the mucosal and serosal surfaces were selectively exposed to 3.0, 5.0, 1.0, 0.1 and 0.001 mM of olsalazine, sulphasalazine and 5-ASA. The maximal short circuit current (Isc, a measure of active anion secretion) was determined for each concentration. Olsalazine significantly stimulated anion secretion at concentrations above 0.001 mM with a more pronounced effect (approximate ED50 of 0.5 mM) when added to the mucosal surface. In contrast, sulphasalazine and 5-ASA demonstrated no secretory effect. Additional studies of transmucosal fluxes and chemical mediation of these effects are in progress and will be reported. Olsalazine stimulat...
Differential regulation of innate immune response genes in gingival epithelial cells stimulated with Aggregatibacter actinomycetemcomitans.

Background and Objective: The gingival epithelium provides the first line of defense against colonization by periodontal pathogens, both as a physical barrier and by the production of inducible innate immune mediators such as β-defensins and pro-inflammatory cytokines. The gram-negative bacterium Aggregatibacter actinomycetemcomitans is implicated in the pathogenesis of localized aggressive periodontitis, although the bacterium is found widely in the healthy population. We hypothesized that gingival epithelial cell-derived innate immune mediators triggered in response to A. actinomycetemcomitans infection may play an important role in increased susceptibility to infection. Material and Methods: Primary cultures of human gingival epithelial cells were cultured in the presence of A. actinomycetemcomitans. Total mRNA was examined for the presence of innate immune markers using RT-PCR. Results: We show here that the mRNA levels of human β-defensin 2 and interleukin-8 are elevated by live cultures of a clinical isolate of A. actinomycetemcomitans in cultured gingival epithelial cells from healthy individuals, but not by A. actinomycetemcomitans lipopolysaccharide. Cells from a patient with localized aggressive periodontitis, however, did not respond to this bacterial stimulation. In contrast, the pro-inflammatory cytokine interleukin-19 was induced in cells from both localized aggressive periodontitis and healthy subjects. Examination of Toll-like receptors and associated adapter molecules indicated lower levels of Toll-like receptor 2 mRNA in the localized aggressive periodontitis patient-derived cells compared with cells from healthy subjects. Conclusion: These results suggest that a differential expression of innate immune response genes to A. actinomycetemcomitans in the gingival epithelium could be an underlying factor of susceptibility to localized aggressive periodontitis.
Rapid platelet inhibition after a single capsule of Aggrenox: challenging a conventional full-dose aspirin antiplatelet advantage?

Aggrenox® is a novel combination of 25 mg of aspirin with 200 mg of sustained release dipyridamole. In a recent large trial (ESPS-2), Aggrenox® was twice as effective for secondary stroke prevention as either aspirin or dipyridamole alone, suggesting superior platelet inhibition for combination therapy. We sought to compare the time course of platelet inhibition with Aggrenox® compared with escalating doses of non-enteric coated aspirin. Data from 10 healthy volunteers were analyzed. Fasting subjects sequentially ingested aspirin in the following order: 325 mg, 81 mg, 25 mg, and then one pill of Aggrenox® after a 3-week interval for aspirin washout. Platelet function was assessed at baseline, 15, 30, 60, and 120 min post-medication with 5 μM epinephrine and 5 μM ADP using conventional aggregometry. Aspirin provided significant (P < 0.01) reduction of platelet aggregation at 15 min post 325 mg, 30 min post 81 mg, and unexpectedly within 60 min after taking 25 mg of aspirin. A single pill of Aggrenox® also inhibited platelet aggregation within 1 hr after administration. Aspirin inhibits platelets remarkably fast. Both Aggrenox® and a matching dose of aspirin (25 mg) exhibit significant antiplatelet properties within 60 min after ingestion. These findings could be relevant for the optimal balance between the reduction of vascular events via sufficient and rapid platelet inhibition and low risk of bleeding complications associated with the Aggrenox® therapy. Am. J. Hematol. 72:280–281, 2003. © 2003 Wiley-Liss, Inc.
Port geometry and its influence on vitrectomy.

Purpose:To determine the influence of port geometry on water and vitreous flow rates and test novel vitreous cutter tips in specific surgical situations.Methods:Custom 20-gauge and 25-gauge vitreous cutter tips with different sized ports were evaluated through porcine vitreous and water flow rates.
Invariant tori in perturbed three vortex motion

The motion of three point vortices in an ideal fluid in a plane comprises a Hamiltonian dynamical system - one that is completely integrable, so it exhibits numerous periodic orbits, and quasiperiodic orbits on invariant tori. Certain perturbations of three vortex dynamics, such as three vortex motion in a half-plane, are also Hamiltonian, but not completely integrable. Yet these perturbed systems may still have periodic trajectories and invariant tori close to those for the unperturbed dynamics. Extending recent work by the authors [4], invariant 2-tori approximating those for the unperturbed system are located and analyzed using a combination of classical analysis, asymptotics, and Hamiltonian methods. It is shown that the results and approximation methods used are applicable to several perturbations of three vortex dynamics such as three vortices in a half-plane, the restricted four vortex problem in the plane, and three coaxial vortex rings in 3-space.
Intracellular sodium homeostasis in rat hippocampal astrocytes.

1. We determined the intracellular Na+ concentration ([Na+]i) and mechanisms of its regulation in cultured rat hippocampal astrocytes using fluorescence ratio imaging of the Na+ indicator SBFI-AM (acetoxymethylester of sodium-binding benzofuran isophthalate, 10 microM). Dye signal calibration within the astrocytes showed that the ratiometric dye signal changed monotonically with changes in [Na+]i from 0 to 140 nM. The K+ sensitivity of the dye was negligible; intracellular pH changes, however, slightly affected the 'Na+' signal. 2. Baseline [Na+]i was 14.6 +/- 4.9 mM (mean +/- S.D.) in CO2/HCO3(-)-containing saline with 3 mM K+. Removal of extracellular Na+ decreased [Na+]i in two phases: a rapid phase of [Na+]i reduction (0.58 +/- 0.32 mM min-1) followed by a slower phase (0.15 +/- 0.09 mM min-1). 3. Changing from CO2/HCO3(-)-free to CO2/HCO3(-)-buffered saline resulted in a transient increase in [Na+]i of approximately 5 mM, suggesting activation of inward Na(+)-HCO3- cotransport by CO2/HCO3-. During furosemide (frusemide, 1 mM) or bumetanide (50 microM) application, a slow decrease in [Na+]i of approximately 2 mM was observed, indicating a steady inward transport of Na+ via Na(+)-K(+)-2Cl- cotransport under control conditions. Tetrodotoxin (100 microM) did not influence [Na+]i in the majority of cells (85%), suggesting that influx of Na+ through voltage-gated Na+ channels contributed to baseline [Na+]i in only a small subpopulation of hippocampal astrocytes. 4. Blocking Na+, K(+)-ATPase activity with cardiac glycosides (ouabain or strophanthidin, 1 mM) or removal of extracellular K+ led to an increase in [Na+]i of about 2 and 4 mM min-1, respectively. This indicated that Na+, K(+)-ATPase activity was critical in maintaining low [Na+]i in the face of a steep electrochemical gradient, which would favour a much higher [Na+]i. 5. Elevation of extracellular K+ concentration ([K+]o) by as little as 1 mM (from 3 to 4 mM) resulted in a rapid and reversible decrease in [Na+]i. Both the slope and the amplitude of the [K+]o-induced reductions in [Na+]i were sensitive to bumetanide. A reduction of [K+]o by 1 mM increased [Na+]i by 3.0 +/- 2.3 mM. In contrast, changing extracellular Na+ concentration by 20 mM resulted in changes in [Na+]i of less than 3 mM. 6. These results implied that in hippocampal astrocytes low baseline [Na+]i is determined by the action of Na(+)-HCO3- cotransport, Na(+)-K(+)-2Cl- cotransport and Na+, K(+)-ATPase, and that both Na+, K(+)-ATPase and inward Na(+)-K(+)-2Cl cotransport are activated by small, physiologically relevant increases in [K+]o. These mechanisms are well suited to help buffer increases in [K+]o associated with neural activity.
Structural correlates of function in the “opercularis” muscle of amphibians

This study characterizes the fine structure of the “opercularis” muscles of selected frogs and salamanders (Genera: Hyla; Desmognathus; Ambystoma). The “opercularis” muscle originates on the shoulder girdle and inserts on the opercular plate in the fenestra ovalis of the otic capsule. Each of the three genera used exhibits one of the major gross dispositions of this muscle found in amphibians. In each case the “opercularis” muscle contains large numbers of tonic fibers: 80% in Hyla; 90% in Desmognathus; 45% in Ambystoma. These fibers correspond to the class-5 tonic fibers of Smith and Ovalle (1973). The remainder of the fibers in the “opercularis” correspond to those in the class-3 “phasic” of Smith and Ovalle. The muscle from which the “opercularis” is derived (levator scapulae in Hyla, cucullaris in Desmognathus) is comprised of fibers which correspond to the class-2 phasic fibers of Smith and Ovalle. The fiber composition of the “opercularis” indicates that it is constructed to sustain contraction over long periods of time. This composition is supportive of the functional role in audition proposed for the muscle by Lombard and Straughan (1974). Evidence is presented that indicates that fiber size may be body size dependent and thus is an inappropriate criterion of fiber type identification.
Five-coordinate organoaluminum acetylides and crystal structure of the hydrosylate, [Salophen(tBu)Al]2O

Abstract The first examples of five coordinate aluminum acetylide compounds chelated by a single ligand are reported in this paper. The combination of L(tBu)AlCl (where L=Salen (1), Salpen (2), Salophen (3), Salomphen (4)) with LiCCPh in THF at −78 °C leads to the formation of the four acetylides (5–8), LCCPh. These are extremely moisture sensitive and readily hydrolyze to form aluminum hydroxides and with condensation form compounds of formula [L(tBu)Al]2O. The hydrosylate [Salophen(tBu)Al]2O (9) has been structurally characterized.
Alterations in cytoskeletal protein sulfhydryls and cellular glutathione in cultured cells exposed to cadmium and nickel ions.

To understand the mechanisms of Cd2+ and Ni2+ cytotoxicity, we have studied the effects of these two metal ions on the organization of cytoskeletal elements, microtubules (MT) and microfilaments (MF), cytoskeletal protein sulfhydryls and cellular glutathione (GSH) in cultured 3T3 cells. At a metal ion dose that caused 95% inhibition of DNA synthesis, Cd2+ (10 microM, 16 h exposure) induced MT depolymerization whereas Ni2+ (2 mM, 20 h exposure) elicited MT aggregation and bundling. Under these conditions, Cd2+ and Ni2+ also caused MF aggregation and redistribution. Furthermore, exposure of cells to Cd2+ resulted in a dose-dependent increase in cytoskeletal protein sulfhydryls and cellular GSH levels. In contrast, treatment of cells with Ni2+ resulted in a dose-dependent decrease in cytoskeletal protein sulfhydryls as well as cellular GSH content. Time course studies showed that cells exposed to 10 microM Cd2+ exhibited a biphasic response in regulating their cytoskeletal protein sulfhydryls and cellular GSH, e.g. an initial decrease followed by a steady recovery and overshooting upon prolonged incubation. However, restoration of cytoskeletal protein sulfhydryls occurred approximately 2 h after commencement of cellular GSH recovery in Cd(2+)-treated cells. These results suggest that cellular GSH may play an important role in regulating cytoskeletal protein sulfhydryls. On the other hand, decrease of cellular GSH induced by Ni2+ might facilitate oxidation of cytoskeletal protein sulfhydryls and formation of disulfide bonds between individual MT polymers which would favor MT aggregation in Ni(2+)-exposed cells. In addition, we also demonstrated that elevation of cellular GSH in Cd(2+)-treated cells probably resulted from new GSH synthesis.
Inhibition of luteinizing hormone release and ovulation in PMS-treated rats by peripherally administered melatonin.

Abstract The influence of intraperitoneally administered melatonin on ovulation and the plasma content of luteinizing hormone in pregnant mare's serum (PMS) treated immature rats was tested. Melatonin, administered in three equivalent doses of 500 μg each at 2:00, 3:00 and 4:00 P. M. on the second day after PMS administration, reduced the number of rats that ovulated. Melatonin also prevented the rise in plasma luteinizing hormone which occurred in the majority of the control animals at 57 hours after PMS administration.
Progressive soft-tissue necrosis.

A 52-year-old man with type 2 diabetes mellitus and end-stage renal disease presented with painful and progressive cutaneous necrosis of his fingers, toes, and calves and generalized muscle weakness with difficulty getting out of bed and walking. He had undergone hemodialysis for the past year and had a brachiocephalic fistula in his left arm. Hismedical historywasalso significant forperipheral vascular disease, hypertension, andantiphospholipid antibody syndrome for which hewas receivingwarfarin sodium since 2010. His other medications were epoetin alpha, ferrous gluconate, cinacalcet hydrochloride, paricalcitol, sevelamer carbonate, amlodipine besylate, labetalol hydrochloride, lisinopril, simvastatin, pentoxifylline, and Humalog and Lantus insulin. He did not smoke. The patient had a temperature of 37.6°C and a grade II/VI systolic ejectionmurmur. He had necrosis and eschar formation involving his fingers (Figure 1A), toes (Figure 1B and C), and left posteriormedial calf (Figure 1D). He had violaceous skinwith central eschar on the posteriormedial aspect of his right leg (Figure 1E) thatwas exquisitely tenderwith gangrenous change.Hehadnormal femoral pulseswithnodistalpulsespalpable.Both feetwerewarmwithgoodDoppler signals in the dorsalis pedis and posterior tibial arteries. He had a palpable pulse and thrill in the brachiocephalic fistula in his left upper arm. There was also a weak distal radial pulse. He had good Doppler signals over the radial, ulnar, and palmar arch arteries bilaterally. Laboratory studies revealed awhite blood cell count of 13 900/μL (to convert to ×109 per liter, multiply by 0.001), a hemoglobin level of 7.7 g/dL (to convert to grams per liter, multiply by 10.0), a platelet count of 309 × 103/μL (to convert to ×109per liter,multiply by 1.0), an international normalized ratio of 2.4, a blood urea nitrogen level of 88 mg/dL (to convert to millimoles per liter, multiply by 0.357), a creatinine level of 9.9 mg/dL (to convert to micromoles per liter, multiply by 88.4), a calcium level of 7.5 mg/dL (to convert to millimoles per liter,multiply by0.25), an albumin level of 2.4 g/dL (to convert to grams per liter, multiply by 10), and an intact parathyroid hormone level of 349.7 pg/mL (to convert to nanograms per liter, multiply by 1.0). A skin biopsy specimen of the calf showed epidermal necrosis, dermal hemorrhage, focal dermal intravascular thrombi, and subcutaneous intravascular and extravascular calcifications. Quiz at jamasurgery.com A D E
TEMPORAL TRENDS IN OUTCOMES AFTER CORONARY REVASCULARIZATION IN ADULTS WITH END-STAGE RENAL DISEASE IN KAISER PERMANENTE NORTHERN CALIFORNIA

Limited data exists about recent temporal trends of outcomes after coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) in the growing population of end-stage renal disease (ESRD) patients receiving chronic dialysis. Within Kaiser Permanente Northern California, a
Convenient preparation of N‐substituted 2‐amino‐4H‐3,l‐benzoxazin‐4‐ones and 3‐substituted 2,4(1H,3H)‐quinazolinediones

Room temperature treatment of 2-(3-arylureido)benzoic acids (1) and methyl 2-(3-alkyl-, or 3-arylureido)- benzoates (2) with concentrated sulfuric acid leads to N-substituted 2-amino-4H-3,l-benzoxazin-4-ones (3) in generally very good yields. The isomeric 3-substituted 2,4(1H,3H)-quinazolinediones (4) are conveniently made in high yield by the action of aqueous-ethanolic sodium hydoxide on 2.
The Limited Use of Distinctive Features and Markedness in Speech Production: Evidence from Speech Error Data.

Analysis of a phoneme confusion matrix consisting of 1620 spontaneous speech errors shows that each consonant segment appears as an intrusion just about as often as it appears as a target, with the exception of a small set of four segments (/s//t//s//c/) for which there is a target-intrusion asymmetry in the direction of more frequent “palatalizing” errors. With this qualification, it is shown that there is no tendency for linguistically unmarked consonants to replace marked consonants. It is also shown that sound segment errors almost always involve the movement of unitary segments and not the movement of component distinctive features. These results, confirmed in an independently collected corpus of 1369 errors, are compatible with a model of the speech production process in which (1) most phoneme errors occur as the result of a mis-selection between two similar planning segments competing for a single location in an utterance, although (2) voiceless alveolar consonants are subject to a palatalizing mechanism which is the source of further segmental errors.
Differing responses of hamsters to infection by vesicular stomatitis virus Indiana and New Jersey serotypes

Intraperitoneal injection of vesicular stomatitis virus, New Jersey serotype (VSV-NJ), into inbred LSH hamsters resulted in an inapparent infection and survival of the majority of the animals. Infectivity titrations of tissues from VSV-NJ-infected hamsters showed that little or no virus was present following infection. The few animals that died from VSV-NJ succumbed to neurological disease. This is in contrast to our previous work where we found that LSH hamsters are exquisitely sensitive to i.p. infection by VSV, Indiana serotype (VSV-IND), and that large amounts of VSV-IND could be detected in tissues. The 50% lethal doses of VSV-NJ and VSV-IND for LSH hamsters are approximately 10(7) pfu and 1 pfu, respectively. When peritoneal cells from LSH hamsters were infected in vitro with both VSV serotypes, the yields of VSV-NJ consistently were lower than yields of VSV-IND. The growth of the two serotypes in fibroblast and epithelial cell lines of hamster origin was similar. VSV-NJ was not more efficient than VSV-IND in inducing interferon in vitro or in vivo, and there appeared to be no difference in the sensitivities of the two serotypes to the antiviral activity of hamster interferon. Thus, i.p. infection with less than 10(7) pfu of VSV-NJ is avirulent for LSH hamsters and this avirulence may be due, in part, to partial intrinsic resistance of peritoneal macrophages to infection by VSV-NJ. When four LSH hamsters that had been immunized with VSV-NJ were challenged with 10(6) LD50 of VSV-IND, three of the four animals survived. Despite the fact that neutralizing antibodies to VSV-NJ did not cross-neutralize VSV-IND, five out of five LSH hamsters were protected by passive transfer of 1 ml of immune hamster anti-VSV-NJ antiserum prior to challenge with VSV-IND. This suggests an important role for non-neutralizing antibodies.
Deformation-twin-induced grain boundary failure

This work presents a mechanism of deformation-twin-induced grain boundary failure, and demonstrates the mechanism using molecular dynamics simulations. Deformation twinning is observed as the dominant mechanism during tensile deformation of 〈1 1 0〉 columnar nanocrystalline body-centered cubic Mo. As a twin approaches a grain boundary, local stress concentration develops due to the incompatible plastic deformations in the two neighboring grains. The magnitude of the stress concentration increases as the twin widens, leading to grain boundary cracking by nucleation and coalescence of microcracks/voids.
Computerized Image Analysis of Surface Browning of Pizza Shells

An objective measurement using computerized image analysis techniques was developed for determining the level of brownness on the bottom surface of pizzas. Infrared heat processing (327/332°C) was investigated for both wheat and soy-fortified, wheat pizza shells. Moisture, fat, total and unavailable lysine were determined by chemical analysis. A linear function was developed which shows promise for predicting the available lysine content for soy-fortified shells. This function utilizes information taken from the image of the bottom of the pizza. This technique could be useful in cases where a rapid, nondestructive test for available lysine in baked dough is needed.