cssi/SciSciGPT-SciSciNet huggingface dataset:
Stimulation of ovarian development and egg laying by male courtship vocalization in budgerigars (Melopsittacus undulatus)

Abstract Five different tape recorded groups of male vocal patterns were played each to a different group of females kept in constant darkness. Soft Warble, a vocalization closely associated with visible male precopulatory behaviour patterns and performed in intimate relation to the female, was found to greatly stimulate ovarian activity and egg laying in budgerigars. Other vocalizations produced results insignificantly different from a control group hearing no vocalization. While either component half of arbitrarily divided Soft Warble seemed just as stimulating to ovarian development as the other half, daily presentation of either for 6 hours hours was more effective than 3 hours.
A theory of protein dynamics to predict NMR relaxation.

We present a theoretical, site-specific, approach to predict protein subunit correlation times, as measured by NMR experiments of 1H-15N nuclear Overhauser effect, spin-lattice relaxation, and spin-spin relaxation. Molecular dynamics simulations are input to our equation of motion for protein dynamics, which is solved analytically to produce the eigenvalues and the eigenvectors that specify the NMR parameters. We directly compare our theoretical predictions to experiments and to simulation data for the signal transduction chemotaxis protein Y (CheY), which regulates the swimming response of motile bacteria. Our theoretical results are in good agreement with both simulations and experiments, without recourse to adjustable parameters. The theory is general, since it allows calculations of any dynamical property of interest. As an example, we present theoretical calculations of NMR order parameters and x-ray Debye-Waller temperature factors; both quantities show good agreement with experimental data.
Statistical analysis of cleavage fracture ahead of sharp cracks and rounded notches

Abstract Mechanisms of initiation and unstable propagation of transgranular cleavage cracks are compared for brittle fracture ahead of sharp cracks and rounded notches, e.g. for fatigue pre-cracks and Charpy V-notches, respectively, in standard toughness specimens. The comparison is made over a range of temperatures, from the lower shelf into the ductile/brittle transition region, for a single phase material containing a known distribution of particles where weakest link statistics can be used to model the onset of catastrophic failure. Using linear and nonlinear elastic solutions for the stress distribution ahead of a sharp crack, and slip-line field solutions, modified for a power hardening material, for the rounded notch, statistical modelling is employed to define the critical dimensions ahead of the crack or notch tip where initial cracking events are most probable. The analysis provides an interpretation of the role of stress gradient in governing microscopic fracture behavior. Predictions are evaluated by comparison with experimental results on the low temperature flow, Charpy V-notch and plane strain fracture toughness behavior of a low carbon mild steel with simple ferrite/grain boundary carbide microstructures.
Re-examination of the assay for plasma prostanoids by solid-phase extraction, and radioimmunoassay

Abstract A method for the routine assay of plasma thromboxane and prostacyclin metabolites, thromboxane B 2 and 6ketoprostaglandin F 1α (employing solid phase extraction to remove the metabolites from interfering substances) and using commercially available antisera for their radioimmunoassay has been investigated. Modifications of previously published procedures have been explored, including the use of non-explosive solvents in the extraction procedure, and inclusion of a non-cross reacting internal standard, prostaglandin D 2 , to estimate recovery through the extraction procedures. Both the original and modified procedures can produce high blank values, which apparently result from the solid-phase extraction. These high backgrounds are constant for a given lot of solid phase extraction cartridges and can be corrected by subtraction. The modified method is linear with volume of plasma assayed to as little as one ml, and all cross-reacting material in normal human plasma was found to co-chromatograph with authentic standards on reverse-phase high performance liquid chromatography. Values for normal adult plasmas were found to be 0.44 ±.15 pmol/ml 6keto PGF i1α (mean ± SD) and .103±.07 for thromboxane B 2 . The method reported provides a convenient, reproducible way to assay these important plasma prostanoids.
Water Vapor Permeability of Caseinate‐Based Edible Films as Affected by pH, Calcium Crosslinking and Lipid Content

Edible films were cast from solutions of sodium or calcium caseinate and from emulsions of these proteins with acetylated monoglyceride, beeswax, and stearic acid. The water vapor permeabilities of the films were evaluated at 25°C using the ASTM E96–80 method, modified to calculate the % relative humidity at the film underside. Adjustment to pH 4.6 (isoelectric point), calcium ion crosslinking and combined effects of calcium ascorbate buffer (pH 4.6) reduced water vapor permeability of sodium caseinate films by 36%, 42%, and 43%, respectively. Calcium caseinate-beeswax emulsion films had water vapor permeabilities up to 90% lower than pure sodium caseinate films. Water vapor permeability varied by a factor of two depending on emulsion film orientation, indicating nonisotropic structure.
Intravenous ascorbate improves spatial memory in middle-aged APP/PSEN1 and wild type mice

Abstract The present study investigated the effects of a single intravenous (i.v.) dose of Vitamin C (ascorbate, ASC) on spatial memory in APP/PSEN1 mice, an Alzheimer's disease model. First, we confirmed the uptake time course in ASC-depleted gulo (−/−) mice, which cannot synthesize ASC. Differential tissue uptake was seen based on ASC transporter distribution. Liver (SVCT1 and SVCT2) ASC was elevated at 30, 60 and 120 min post-treatment (125 mg/kg, i.v.), whereas spleen (SVCT2) ASC increased at 60 and 120 min. There was no detectable change in cortical (SVCT2 at choroid plexus, and neurons) ASC within the 2-h interval, although the cortex preferentially retained ASC. APP/PSEN1 and wild type (WT) mice at three ages (3, 9, or 20 months) were treated with ASC (125 mg/kg, i.v.) or saline 45 min before testing on the Modified Y-maze, a two-trial task of spatial memory. Memory declined with age and ASC treatment improved performance in 9-month-old APP/PSEN1 and WT mice. APP/PSEN1 mice displayed no behavioral impairment relative to WT controls. Although dopamine and metabolite DOPAC decreased in the nucleus accumbens with age, and improved spatial memory was correlated with increased dopamine in saline treated mice, acute ASC treatment did not alter monoamine levels in the nucleus accumbens. These data show that the Modified Y-maze is sensitive to age-related deficits, but not additional memory deficits due to amyloid pathology in APP/PSEN1 mice. They also suggest improvements in short-term spatial memory were not due to changes in the neuropathological features of AD or monoamine signaling.
Function of prostaglandin E2 EP receptors in the acute outcome of rodent hypoxic ischemic encephalopathy.

Abstract Neonatal hypoxic-ischemic encephalopathy (HIE) is a leading cause of severe and permanent neurologic disability after birth. The inducible cyclooxygenase COX-2, which along with COX-1 catalyzes the first committed step in prostaglandin (PG) synthesis, elicits significant brain injury in models of cerebral ischemia; however its downstream PG receptor pathways trigger both toxic and paradoxically protective effects. Here, we investigated the function of PGE 2 E-prostanoid (EP) receptors in the acute outcome of hypoxic-ischemic (HI) injury in the neonatal rat. We determined the temporal and cellular expression patterns of the EP1–4 receptors before and after HIE and tested whether modulation of EP1–4 receptor function could protect against cerebral injury acutely after HIE. All four EP receptors were expressed in forebrain neurons and were induced in endothelial cells after HIE. Inhibition of EP1 signaling with the selective antagonist SC-51089 or co-activation of EP2–4 receptors with the agonist misoprostol significantly reduced HIE cerebral injury 24 h after injury. These receptor ligands also protected brain endothelial cells subjected to oxygen glucose deprivation, suggesting that activation of EP receptor signaling is directly cytoprotective. These data indicate that the G-protein coupled EP receptors may be amenable to pharmacologic targeting in the acute setting of neonatal HIE.
E-Business in Developing Countries: A Comparison of China and India

The Internet has changed the way many companies do business, but has also tended to increase the disparity between firms in developed countries and those in developing countries. As the digital divide seems to grow, the question becomes how will developing countries catch up? We examine two large developing countries, China and India, in an attempt to understand their approaches to developing e-business. While both countries had access to the technology at about the same time, each has taken a different path to utilizing it. These approaches are based on a number of factors, including government initiatives and focus, infrastructure building, experience and understanding of business operations, and culture, among others. China appears to be ahead of India in the mechanics and infrastructure, but India is ahead in e-readiness. Both countries are poised for rapidly increasing e-business, however, they have huge problems of poverty and inequality between urban and rural connectivity must be resolved to really take advantage of e-business.
Transfection Activity of Binary Mixtures of Cationic O-Substituted Phosphatidylcholine Derivatives: The Hydrophobic Core Strongly Modulates Physical Properties and DNA Delivery Efficacy

A combination of two cationic lipid derivatives having the same headgroup but tails of different chain lengths has been shown to have considerably different transfection activity than do the separate molecules. Such findings point to the importance of investigating the hydrophobic portions of cationic amphiphiles. Hence, we have synthesized a variety of cationic phosphatidylcholines with unusual hydrophobic moieties and have evaluated their transfection activity and that of their mixtures with the original molecule of this class, dioleoyl-O-ethylphosphatidylcholine (EDOPC). Four distinct relationships between transfection activity and composition of the mixture (plotted as percent of the new compound added to EDOPC) were found, namely: with a maximum or minimum; with a proportional change; or with essentially no change. Relevant physical properties of the lipoplexes were also examined; specifically, membrane fusion (by fluorescence resonance energy transfer between cationic and anionic lipids) and DNA unbinding (measured as accessibility of DNA to ethidium bromide by electrophoresis and by fluorescence resonance energy transfer between DNA and cationic lipid), both after the addition of negatively charged membrane lipids. Fusibility increased with increasing content of second cationic lipid, regardless of the transfection pattern. However, the extent of DNA unbinding after addition of negatively charged membrane lipids did correlate with extent of transfection. The phase behavior of cationic lipids per se as well as that of their mixtures with membrane lipids revealed structural differences that may account for and support the hypothesis that a membrane lipid-triggered, lamellar→nonlamellar phase transition that facilitates DNA release is critical to efficient transfection by cationic lipids.
Oriented bismuth titanate thin films by single-solid-source metal-organic chemical vapour deposition

Single-phase Bi4Ti3O12 thin films were successfully deposited on Pt/SiO2/Si substrates using a single-solid-source metal-organic chemical vapour deposition technique with triphenylbismuth [(C6H5)3Bi] and titanium (IV) methoxide [Ti(OCH3)4] as precursors. The formation and orientation of the Bi4Ti3O12 phase were controlled by varying the ratio of bismuth to titanium in the precursor mixture. Highly c-axis oriented films were deposited under high bismuth conditions. Films with about 90% orientation exhibited an average dielectric constant of K=132, and a dielectric loss factor of .
Trends in cardiovascular disease risk factors by educational level: The Stanford five-city project☆

Background. Trends in blood pressure, smoking, and cholesterol were examined from 1979–1980 through 1985–1986 in four cities in California by level of education (<high school, high school graduate, some college, college or postgraduate). Methods. Four biennial cross-sectional surveys (n = 6,580) were conducted in two treatment and two control cities to evaluate a 6-year community health education intervention, conducted as part of the Stanford Five-City Project. Results. Over the 8-year study period, men and women ages 25–74 from each educational group in the treatment cities showed significant declines in smoking prevalence and levels of blood pressure and cholesterol (with the exception of cholesterol in women). In general, declines in the least educated group (<high school) were stronger than declines in the most educated group (college or postgraduate). Similar declines occurred in each educational group in control cities. Conclusions. These results illustrate that persons from all educational levels can modify their risk for CVD and are of particular importance because of the higher prevalence of CVD risk factors among those with less education. The similarity of time trends in treatment as well as control cities suggests that the broad-based, multisource health education efforts in the United States are succeeding across the educational spectrum.
Statin therapy after stroke or transient ischemic attack--a new weapon in our secondary stroke prevention arsenal?

Statin therapy after stroke or transient ischemic attack—a new weapon in our secondary stroke prevention arsenal?
A Bayesian analysis of kriging

This article is concerned with predicting for Gaussian random fields in a way that appropriately deals with uncertainty in the covariance function. To this end, we analyze the best linear unbiased prediction procedure within a Bayesian framework. Particular attention is paid to the treatment of parameters in the covariance structure and their effect on the quality, both real and perceived, of the prediction. These ideas are implemented using topographical data from Davis.
Loving Writing Fragments D'Un Discours Amoureux

(2000). Loving Writing Fragments D'Un Discours Amoureux. Symposium: A Quarterly Journal in Modern Literatures: Vol. 54, No. 1, pp. 27-42.
Sensitivity of probability-of-failure estimates with respect to probability of detection curve parameters

Abstract A methodology has been developed and demonstrated that can be used to compute the sensitivity of the probability-of-failure (POF) with respect to the parameters of inspection processes that are simulated using probability of detection (POD) curves. The formulation is such that the probabilistic sensitivities can be obtained at negligible cost using sampling methods by reusing the samples used to compute the POF. As a result, the methodology can be implemented for negligible cost in a post-processing non-intrusive manner thereby facilitating implementation with existing or commercial codes. The formulation is generic and not limited to any specific random variables, fracture mechanics formulation, or any specific POD curve as long as the POD is modeled parametrically. Sensitivity estimates for the cases of different POD curves at multiple inspections, and the same POD curves at multiple inspections have been derived. Several numerical examples are presented and show excellent agreement with finite difference estimates with significant computational savings.
Modeling Regulatory Mechanisms in IL-6 Signal Transduction in Hepatocytes

Cytokines like interleukin-6 (IL-6) play an important role in triggering the acute phase response of the body to injury or inflammation. Signaling by IL-6 involves two pathways: Janus-associated kinases (JAK) and signal transducers and activators of transcription (STAT 3) are activated in the first pathway while the second pathway involves the activation of mitogen-activated protein kinases (MAPK). While it is recognized that both pathways play a major role in IL-6 signal transduction, a majority of studies have focused on signaling through either one of the pathways. However, simultaneous signaling through both JAK/STAT and MAPK pathways is still poorly understood. In this work, a mathematical model has been developed that integrates signaling through both the JAK/STAT and the MAPK pathway. The presented model is used to analyze the effect of three molecules that are involved in the regulation of IL-6 signaling-SHP-2 (domain containing tyrosine phosphatase 2), SOCS3 (suppressor of cytokine signaling 3), and a STAT3 nuclear phosphatase (PP2)-on the dynamics of IL-6 signal transduction in hepatocytes. The obtained results suggest that interactions between SHP-2 and SOCS3 influence signaling through the JAK/STAT and the MAPK pathways. It is shown that SHP-2 and SOCS3 do not just regulate the pathway that they are known to be associated with, (SHP-2 with MAPK and SOCS3 with JAK/STAT), but also have a strong effect on the other pathway. Several simulations with SOCS3, SHP-2, and PP2 knockout cells, that is, where the signaling pathway is unable to produce these proteins, have been performed to characterize the effect of these regulatory proteins on IL-6 signal transduction in hepatocytes.
Renal water reabsorption: A physiologic retrospective in a molecular era

Renal water reabsorption: A physiologic retrospective in a molecular era. The cloning and sequencing of the aquaporin water channels has been an enormous advance in the biomedical sciences, as recognized by the award of the Nobel Prize to Peter Agre last year. Among many other examples, expression of aquaporin proteins in Xenopus oocytes and other heterologous expression systems has confirmed two important models of renal function: the increase in the water permeability of the collecting duct by antidiuretic hormone (ADH), and the mechanism of near isosmotic volume reabsorption by the proximal tubule. These mechanisms were the subjects of intensive investigation by numerous investigators, including Thomas E. Andreoli, who is being honored by this symposium, and who developed many of the key concepts in these areas. His early work with artificial lipid bilayer membranes and the pore-forming antibiotic amphotericin provided the rigorous foundation in experimental and conceptual modeling techniques that he later applied to physiologic and pathophysiologic mechanisms in the kidney, which are summarized in this retrospective. Dr. Andreoli and his colleagues proposed a water channel mechanism for the action of ADH, which has been confirmed by the cloning and heterologous expression of aquaporin-2. They also proposed that volume reabsorption by the proximal tubule depended on a very high hydraulic conductivity and the development of luminal hypotonicity produced by active solute reabsorption. This model has also been confirmed in mice in which aquaporin-1 expression is knocked out, resulting in a low proximal tubule water permeability that exaggerates the development of luminal hypotonicity.
Cardiovascular applications of hyperpolarized contrast media and metabolic tracers

Modern hyperpolarization technology enhances the recordable magnetic resonance signal four to five orders of magnitude, making in vivo assessments of tracer pathways and metabolic compartments feasible. Existing hyperpolarization instrumentation and previous tracer studies using hydroxyethylpropionate (HEP) as an extracellular marker and 14-carbon label pyruvate as examples are described and reviewed as applicable to the working heart. Future metabolic imaging based on the use of hyperpolarized pyruvate needs to consider extra- and intra-cellular label dilution due to glycolysis, lactate oxidation and protein degradation. This dilution can substantially decrease the recordable signals from PDH flux (oxidative decarboxylation of pyruvate) and other pyruvate pathways. The review of previous literature and data suggests that the (13)C-alanine signal is a better index of mitochondrially oxidized pyruvate than L-lactate. These facts and considerations will help in the interpretation of the in vivo recorded hyperpolarization signals of metabolic tracers and contrast media.
Domain-specific monoclonal antibodies to ovotransferrin indicate conservation of determinants involved in avian transferrin receptor recognition.

Abstract 1. 1. Three of five monoclonal antibodies produced to chicken ovotransferrin bound quail ovotransferrin but none of the antibodies bound human, bovine or equine serum transferrin. 2. 2. Equilibrium binding experiments indicate that both quail and chicken ovotransferrin bind to transferrin receptors on chick reticulocytes although the quail protein binds to 40% fewer sites with an affinity which is three times lower than chicken ovotransferrin. 3. 3. The antibodies that recognize quail ovotransferrin block binding of both radiolabelled chicken and quail ovotransferrin to chick reticulocytes. 4. 4. Quail NH2-terminal half-molecule domain appears to be unable to form a functional hybrid holo-ovotransferrin with chicken C-terminal half-molecule domain.
Theory of Recombination in Non-Crystalline Junctions

A theory of non-crystalline recombination junctions is developed and compared to the experimental data. Junction transport is represented as hopping in both real and energy spaces, dominated by rare yet exponentially effective optimum channels having favorable configurations of localized states. Our work correlates the current-voltage characteristics of non-crystalline devices with material parameters and predicts large non-ideality factors increasing under light, and possible variations between nominally identical devices.
Bacterial mutagenicity of some tobacco aromatic nitrogen bases and their mixtures.

Abstract The first aim was to compare the genotoxicities of two tobacco-specific nitrosamines (TSNA), 4-(methylnitrosamino)-(3-pyridyl)-1-butanone (NNK) and N ′-nitrosonornicotine (NNN) in two types of tests, the Salmonella reverse mutation assay (250–2000 μg per plate) and the Mutatox test (up to 1000 μg/ml) using dark mutant M-169 of Vibrio fischeri . The second aim was to assess the effects of single other tobacco chemicals and metabolites (nicotine (NIC), cotinine (COT), trans -3-hydroxycotinine (3HC), cotinine- N -oxide (CNO) and nicotine- N -oxide (NNO)) on the mutagenic responses at relative concentrations observed physiologically. The Salmonella strains were TA100, TA7004, TA7005, and TA7006, all showing missense backmutations that are characteristic of the TSNA. NNN was a direct mutagen to strains TA100, TA7004, and in the Mutatox test, and was not mutagenic in the presence of rat or hamster S9. NNK was mutagenic only in strain TA7004 with rat and hamster S9, but not in TA100, but was directly mutagenic in the Mutatox test. While all the other tobacco chemicals were not mutagenic alone to strains TA100 and TA7004 in the presence and absence of rat or hamster S9, the Mutatox test produced direct mutagenicity for COT, 3HC, and NNO, but not CNO. The latter was mutagenic in the Mutatox test with rat or hamster S9, but only rat S9 was effective for COT, NNO and 3HC. Inhibitory potentiations of NNN by NIC and COT were observed on strain TA7004, and by NIC on strain TA100. There were no interactions on NNK in the presence of S9 for strain TA7004 or TA100. In contrast, a complex inhibition and enhancement behavior occurred in the Mutatox test for each interaction, but no effects were observed for CNO on NNK without S9, and few for NIC on NNK with hamster S9. Compounds which showed no activity alone modulated the genotoxicity of two potent TSNAs in both types of tests.
Lasker Laurels for Telomerase

This year the Lasker Foundation pays tribute to telomerase, a medically important enzyme required for chromosome stability and long-term cell proliferation.
Resolving Discrepancies between Deterministic Population Models and Individual‐Based Simulations

ABSTRACT This work ties together two distinct modeling frameworks for population dynamics: an individual‐based simulation and a set of coupled integrodifferential equations involving population densities. The simulation model represents an idealized predator‐prey system formulated at the scale of discrete individuals, explicitly incorporating their mutual interactions, whereas the population‐level framework is a generalized version of reaction‐diffusion models that incorporate population densities coupled to one another by interaction rates. Here I use various combinations of long‐range dispersal for both the offspring and adult stages of both prey and predator species, providing a broad range of spatial and temporal dynamics, to compare and contrast the two model frameworks. Taking the individual‐based modeling results as given, two examinations of the reaction‐dispersal model are made: linear stability analysis of the deterministic equations and direct numerical solution of the model equations. I also m...
Bistatic Scattering of GPS Signals Off Arctic Sea Ice

This paper evaluates the potential of a global positioning system (GPS) bistatic radar for the retrieval of information concerning the presence and condition of sea ice cover. For this purpose, the permittivity and roughness of a ground scattering target at L-band are extracted from reflected GPS waveforms collected from an airborne platform using the Kirchhoff approximation for the surface cross section. The retrieved GPS estimates are then evaluated against collocated measurements of surface roughness obtained from a lidar profiler and a reference classification of sea ice types inferred from a multisensor data set that includes polarimetric microwave emissions, RADARSAT backscatter, and Moderate Resolution Imaging Spectroradiometer infrared/visible imagery.
The surface transport of adsorbed molecules

A detailed mechanistic model is developed to describe the process by which adsorbed molecules migrate over the surface of an adsorbent. The migration is assumed to occur as a result of a random hopping of partially desorbed species; explicit expressions are derived for the hopping rate and the distance traversed in a single jump for the case of a gas adsorbed on a homogeneous surface. In the degree of detail developed herein experimental determinations are still required (to evaluate an otherwise unknown ratio of partition functions, and the activation free energy) but the pressure or surface concentration dependency of the transport rate is given explicity. The predictions are tested by comparison with three sets of experimental data for hydrocarbons adsorbed on porous glass; these systems were chosen as they may be shown to meet the assumption of an adsorbate migrating over an energetically homogeneous surface under the conditions studied. Reasonable values are found for the parameters and excellent agreement between the observed and predicting trends with pressure is noted in all cases.
A method for automatic generation of a fuzzy model

The goal of this research is to develop a method to automate the process of fuzzy model construction. The method we developed extends the existing methods and is based on a combination of genetic algorithms and statistic techniques. The preliminary testing shows that it has the advantages of implementation simplicity, a short training cycle and simple resulting fuzzy model. >
Efficient Particle Filtering via Sparse Kernel Density Estimation

Particle filters (PFs) are Bayesian filters capable of modeling nonlinear, non-Gaussian, and nonstationary dynamical systems. Recent research in PFs has investigated ways to appropriately sample from the posterior distribution, maintain multiple hypotheses, and alleviate computational costs while preserving tracking accuracy. To address these issues, a novel utilization of the support vector data description (SVDD) density estimation method within the particle filtering framework is presented. The SVDD density estimate can be integrated into a wide range of PFs to realize several benefits. It yields a sparse representation of the posterior density that reduces the computational complexity of the PF. The proposed approach also provides an analytical expression for the posterior distribution that can be used to identify its modes for maintaining multiple hypotheses and computing the MAP estimate, and to directly sample from the posterior. We present several experiments that demonstrate the advantages of incorporating a sparse kernel density estimate in a particle filter.
The development of Wh questions in child speech

The spontaneous speech of three preschool children is analyzed for evidence of the development of the kind of knowledge represented by current transformational treatments of Wh questions. The children are those participating in a longitudinal, naturalistic study of the development of grammar. The first Wh questions seem to be unanalyzed routines or constructions not involving transformations. As Wh questions become more complex and varied, several kinds of evidence of transformational knowledge emerge. All sorts of Wh questions are for a time produced in a form that adults do not model, but which is a hypothetical intermediate in the transformational analysis of adult forms. This child's form seems to involve a preposing operation but to omit a transposing operation. One sort of Wh question, the Why question, seems to be created by one child (Adam) as a direct transform of an antecedent declarative from the mother. In general, there is evidence that children in the preschool years do develop a grammatical structure underlying Wh questions that is much like the structure described in current transformational grammars. Because the abstract underlying structure is not strongly suggested by the surface form of Wh questions, it is difficult to see how it can be learned. However, there are recurrent discourse patterns, involving sentence and constituent exchanges, which are rich in structural information, and these may constitute the basis of a learning process.
EMBRYONIC FLOWER1 Participates in Polycomb Group–Mediated AG Gene Silencing in Arabidopsis

Polycomb group (PcG)-mediated gene silencing is a common developmental strategy used to maintain stably inherited repression of target genes and involves different protein complexes known as Polycomb-repressive complexes (PRCs). In animals, the two best-characterized PcG complexes are PRC1 and PRC2. In this report, we demonstrate that the plant-specific protein EMBRYONIC FLOWER1 (EMF1) functions in maintaining the repression of the flower homeotic gene AGAMOUS (AG) during vegetative development in Arabidopsis thaliana by acting in concert with the EMF2 complex, a putative equivalent of Drosophila melanogaster PRC2. We show that AG regulatory sequences are required for its ectopic expression in both emf1 and emf2 mutants and that EMF2 is required for trimethylation of histone 3 lysine 27 on the AG chromatin. We found that EMF1 interacts directly with AG and that this interaction depends on the presence of EMF2. Together with the finding of EMF1 interference with transcription in vitro, these results suggest that EMF1 enables transcriptional repression of AG after the action of the putative EMF2 complex. Our data indicate that EMF1 plays a PRC1-like role in the PcG-mediated floral repression mechanism.
Athletics and alumni giving: evidence from a highly selective liberal arts college.

Using data on annual giving (between 1990 and 2004) for more than 22,000 active alumni from a highly selective liberal arts college, the authors employ a probit framework to analyze the likelihood of giving and a tobit framework to analyze the determinants of alumni generosity. Both the micro-level analysis and the statistical methodology allow the authors to test for differential impacts (by gender, age, or undergraduate involvement) of sports participation or a winning season on the propensity to give as well as on the generosity of alumni contributions. The results indicate that athletes are more likely to give and that they are more generous than their nonathlete counterparts, especially younger alumni who participated in one of the college's historically most successful high-profile sports. A winning season in this particular sports program also leads to greater alumni giving and more generous gifts.
Distortion in Knit Fabrics and Its Relation to Shrinkage in Laundering

The dimensional changes in laundering of 15 fabrics knit from cotton, viscose, acetate- viscose, and nylon yarns were investigated in relation to changes in fabric structure. The fab rics included plain and rib knit of 24, 28, 32, 36, 40, and 44 courses per inch, and interlock knit of 24, 28, and 32 courses per inch. The geometry of both finished and gray fabrics before and after laundering was compared to the geometry of the same fabrics which had received a manual re laxation treatment. Measurements of wale and course spacings showed that laundering brought about considerable rearrangement in the structure of the fabrics which had not been relaxed. The data for wale versus course spacings followed parabolic curves for the laundered fabrics and for all relaxed fabrics. The relation of the course spacings before and after laundering and of the wale spacings before and after laundering was linear for the fabrics given the relaxation treatment. Dimensional change in length, width, and area of the relaxed fa...
Constrained component deployment in wide-area networks using AI planning techniques

Wide-area network applications are increasingly being built using component-based models, which enable integration of diverse functionality in modules distributed across the network. In such models, dynamic component selection and deployment enables an application to flexibly adapt to changing client and network characteristics, achieve load-balancing, and satisfy QoS requirements. Unfortunately, the problem of finding a valid component deployment is hard because one needs to decide on the set of components while satisfying various constraints resulting from application semantic requirements, network resource limitations, and interactions between the two. In this paper, we propose a general model for the component placement problem and present an algorithm for it, which is based on AI planning algorithms. We validate the effectiveness of our algorithm by demonstrating its scalability with respect to network size and number of components in the context of deployments generated for two example applications - a security-sensitive mail service, and a Webcast service - in a variety of network environments.
Server Frequency Control Using Markov Decision Processes

For a wide range of devices and servers, Dynamic Frequency Scaling (DFS) can reduce energy consumption to various degrees by appropriately trading-off system performance. Efficient DFS policies are able to adjust server frequencies by ex- trapolating the transition of the highly varying workload without incurring much of implementation overhead. This paper models DFS policies of a single server using Markov Decision Processes (MDP). To accommodate the highly varying nature of workload in the proposed MDP, we adopt fluid approximation based on continuous time Markov chain and discrete time Markov chain modeling for the fluid workload generator respectively. Accordingly, we design two frequency controllers (FC), namely C-FC and D-FC, corresponding to the continuous and discrete modeling of the workload generator. We evaluate the proposed policies on synthetic and web traces. The proposed C-FC and D-FC schemes ensure performance satisfaction with moderate energy saving as well as ease of implementation, in comparison with existing DFS policies.
Effects of weight carrying, exercise and a myo-anabolic supplement on growth and muscle.

Summary Weight training is commonly used by human athletes to increase strength and fitness. This study was performed to examine the effect of weight-carrying and nutritional supplementation on muscle development and growth in yourn horses. This study examined the effect of weight-carrying and nutritional supplementation on muscle development and growth. Seventeen horses were divided into 3 groups: controls exercised in a free-flow exercise, a weight group that performed the same exercise, carrying progressively increasing weight up to 45 kg, and a weight-supplement group, that also received a myo-anabolic supplement. Horses were accustomed to handling for 30 days then baseline measurements of weight, body condition score, wither height, hip height, forearm and gaskin circumferences, and cross-sectional area of the longissimus dorsi were taken. Horses were stalled for 108 days then conditioned for 78 days. At the end of conditioning, all measurements were taken again. Supplemented weight-carrying horses increased their lean body tissue, as indicated by greater bodyweight (P<0.05) combined with decreased body condition score (P<0.01). Greater increases in wither height (P = 0.09) and hip height (P<0.01) were seen in weight-carrying horses, probably the result of increased muscle tone. Supplemented weight-carrying horses increased forearm (P<0.01) and gaskin circumferences (P<0.05). It is believed that weight-carrying, when combined with additional dietary protein, enabled greater muscle anabolism. Additional research into the potential additive effect of resistance training and diet are warrented.
Gastric heterotopic pancreas with hemorrhage

Summary Aberrant pancreatic tissue is frequently encountered in abdominal surgery as an incidental finding and possibly less frequently as the cause of the patient's symptoms; few cases are diagnosed preoperatively. Awareness of the condition will increase one's diagnostic acumen. For this reason the above case is added to the literature.
Generalized vertex algebras and duality

Now we return to the setting of Chapter 5. The axioms for a generalized vertex operator algebra do not quite apply to the structure of Ω*, the vacuum space (3.29) (for the Heisenberg algebra (ĥ * ) z ) equipped with the relative vertex operators Y*. In fact, the finite-dimensionality axiom (6.4) and the boundedness axiom (6.5) fail to hold in general, since L is not necessarily positive definite. Moreover, the Jacobi identity (5.11) (Theorem 5.1) differs from the Jacobi identity (6.12) by the insertion of the factor c(ā, b). Of course, a suitable group G would also have to be defined. We would like to extend our axioms so as to include this structure. Then the corresponding generalization of the duality arguments of Chapter 7 would provide an alternate duality-based proof of the Jacobi identity (5.11) (recall Remark 7.18), and in particular, of Theorems 8.6.1 and 8.8.23 of [FLM3]. (The arguments in Chapter 7 above, in the Appendix of [FLM3] and in [FHL] are not sufficiently general to give a duality-based proof of Theorem 8.8.23 of [FLM3] — the special case of (5.11) in which h * = 0 and 〈ā, b〉 ? ∈ Z — because the rational lattice in that theorem is not assumed even or integral, and has an alternating form c(·,·); in the proof of Proposition 7.16, the vector v3 is arbitrary.)
Problem Perception, Knowledge Structure, and Problem-Solving Performance

This chapter discusses the relationship between problem perception and problem-solving performance. It presents the study that examines changes in students' problem perception as they become more proficient problem solvers. In this way, the study provides a direct exploration of the relationship between perception and proficiency. The chapter discusses the kinds of perceptual changes that can be induced by an intensive problem-solving course. It presents students' perceptions of the structural relatedness of mathematical problems before and after the students took an intensive course in mathematical problem solving. Those perceptions were measured with the use of a card sorting task. Students were asked to sort together problems that they thought would have similar solutions. The sort data were analyzed using cluster analysis. The experimental group's pre- and post-instruction sortings were compared with those obtained from two groups, a collection of experts and a control group of students from a non-mathematical problem-solving course given at the same time. The data obtained from the pre-instruction sortings replicate and extend previously obtained results. The data obtained from post-instruction sortings indicate a strong shift in the students' perceptions of problem structure. The collections of problems sorted together by students after instruction are no longer homogeneous with respect to surface structure and they appear to cluster according to deep structure characteristics.
Formation of Nanometer-Scale Dot Arrays from Diblock Copolymer Templates

We have developed four different fabrication processes based on self-organizing diblock copolymers that all produce densely-spaced, uniformly-sized nanometer-scale dot arrays over large wafer areas. We demonstrate the versatility of these techniques through examples of dot arrays formed of metallic, insulating, and polymeric materials. These fabrication processes vary in complexity, utility, and degree of optimization, and we discuss the relative merits of each. The ability to create uniform nanoscale features below lithographic resolution limits may enable key applications in fields such as magnetic recording and microelectronics.
The contribution of practice variation to length of stay for children with perforated appendicitis

Abstract Background Postoperative length of stay (pLOS) is an easily tracked outcome that reflects health care efficiency and resource utilization. The purpose of this study was to determine the contribution of practice variation on pLOS for children with perforated appendicitis. Methods Children ages 2–18years with appendectomy for complicated appendicitis were selected from the National Surgical Quality Improvement Program-Pediatric. Extended pLOS (EpLOS) was defined as ≥7days (75th percentile). The contribution of comorbidities, operative traits, and postoperative complications to EpLOS was evaluated using regression models and matched subgroup analyses. Results Of 2585 children with complicated appendicitis in our study, 835 had EpLOS. Regression analysis found that EpLOS was associated with extended operative time (odds ratio (OR) 1.99; 95% confidence interval (CI) 1.63–2.44), dehiscence (OR 13.19; 95% CI 1.52–114.23), wound infection (OR 7.39; 95% CI 2.63–20.80), organ space infection (OR 92.51; 95% CI 34.03–251.50), and pneumonia (OR 4.55; 95% CI 1.06–19.44). Over three-fourths of the variation in pLOS could not be explained by preoperative, intraoperative, or postoperative factors. Conclusions There is significant variation in pLOS for children undergoing appendectomy that is not accounted for by comorbidities, operative traits, or complications indicating an opportunity to improve outcomes through modifying practice patterns.
Alterations in rabbit retina lipid metabolism induced by detachment. Decreased incorporation of [3H]DHA into phospholipids.

Docosahexaenoic acid (22 ∶ 6n-3, DHA) is found in high concentration in phospholipids from retinal membranes, and is essential for their function. This study investigated the effect of in vivo retinal detachment on in vitro lipid metabolism using [3H]DHA. Rabbit retina was detached from the retinal pigment epithelium by injecting physiological saline into the subretinal space of the eye. Retinal samples from control (non-operated) and sham (operated, no detachment) animals, and from attached and detached retinal areas from the same eye, were incubated in vitro with [3H]DHA for 4 hours, and then prepared for biochemical and autoradiographic analysis. In control and sham retinas, [3H]DHA was preferentially esterified into phospholipids (82%) with low labeling of free fatty acids (FFA) (5%). In samples from detached areas of the retina, a higher proportion of [3H]DHA was recovered in the FFA pool (up to 30%) and its esterification was shunted into triacylglycerol, thereby reducing the formation of [3H]DHA-phospholipids. Changes were sustained through 48 hours of postdetachment. High labeling of inner segments and synaptic terminals was observed autoradiographically in control retinas, while in detached retinas, clusters of labeling were detected in the neural retina, and eventually within the photoreceptor layer. Retinal detachment induces longlasting changes in lipid metabolism which are reflected in lower labeling of [3H]DHA-phospholipids. Metabolic changes, sustained through 48 hours, may lead to inadequate synthesis/turnover of phospholipids, among them, those containing DHA, possibly resulting in defective disc membrane assembly with subsequent deterioration of visual cells.
Fluidization, resolidification, and reorientation of the endothelial cell in response to slow tidal stretches

Mechanical stretch plays an important role in regulating shape and orientation of the vascular endothelial cell. This morphological response to stretch is basic to angiogenesis, neovascularization, and vascular homeostasis, but mechanism remains unclear. To elucidate mechanisms, we used cell mapping rheometry to measure traction forces in primary human umbilical vein endothelial cells subjected to periodic uniaxial stretches. Onset of periodic stretch of 10% strain amplitude caused a fluidization response typified by attenuation of traction forces almost to zero. As periodic stretch continued, the prompt fluidization response was followed by a slow resolidification response typified by recovery of the traction forces, but now aligned along the axis perpendicular to the imposed stretch. Reorientation of the cell body lagged reorientation of the traction forces, however. Together, these observations demonstrate that cellular reorientation in response to periodic stretch is preceded by traction attenuation by means of cytoskeletal fluidization and subsequent traction recovery transverse to the stretch direction by means of cytoskeletal resolidification.