cssi/SciSciGPT-SciSciNet huggingface dataset:
Sequence-specific pausing during in vitro DNA replication on double-stranded DNA templates.

Abstract Sequence-specific pausing occurs during DNA synthesis catalyzed by the bacteriophage T4 DNA polymerase holoenzyme in the presence of the T4 helix destabilizing protein (gene 32 protein). Two of the six strongest pause sites on a double-stranded bacteriophage fd DNA template are in regions where hairpin helices are predicted to form when the DNA is single stranded. However, the other pause sites are in regions that are not obviously involved in secondary structure. The positions of the DNA chain ends produced at one pause site of each type were determined to within +/- 2 nucleotides. At this resolution, a clustering of sites is observed, suggesting that the polymerase holoenzyme may become destabilized when moving along selected regions of the DNA and then pause at one or more of several closely spaced positions. The addition of the T4 gene 41 protein (a DNA helicase that forms part of the T4 primosome) to the above replication system greatly increases the rate of fork movement and eliminates detectable pausing. In contrast, the addition of the T4 dda protein (a second DNA helicase that increases the rate of fork movement to a similar extent) has no affect on replication fork pausing. This difference could either be due to specific protein-protein interactions formed between the polymerase holoenzyme and the 41 protein or to the highly processive movement of the 41 protein along the displaced DNA strand.
Room temperature laser performance of Nd:Y/sub 2/O/sub 3/ at 914 nm

We will report the first ever lasing of Nd:yttria at 914 nm with room temperature operation. The importance of Nd:yttria to the atmospherics science community will be described along with the performance of the Nd:yttria laser at 914 nm and 1073 nm.
Competitive runs: The case of a ceiling on aggregate investment

Abstract Decentralized investment decision in markets with limits on aggregate investment give rise to endogenous and repeated ‘runs’, sudden switches of asset holdings by large groups of small agents. This paper studies a model of recurrent runs in a competitive market with stochastic returns and adjustment costs. The properties of the model are discussed using examples from models of investment in exhaustible resources, of capital controls, of runs on banks' limited reserves.
Vision, High‐Level

The main functions of high-level vision are the recognition and categorization of visual objects and navigation guidance. Keywords: alignment; invariants; linear combination of views; object recognition; recognition by parts; visual similarity
Studying Children in Context: Theories, Methods, and Ethics.

Studying Children in Context: Theories, Methods, and Ethics. M. Elizabeth Graue and Daniel J. Walsh. Thousand Oaks, CA: Sage Publications, 1998. 270 pp.
Maintaining Ties on Social Media Sites: The Competing Effects of Balance, Exchange, and Betweenness

When users interact with one another on social media sites, the volume and frequency of their communication can shift over time, as their interaction strengthens or weakens. We study the interplay of several competing factors in the maintainance of such links, developing a methodology that can begin to separate out the effects of several distinct social forces. In particular, if two users develop mutual relationships to third parties, this can exert a complex effect on the level of interaction between the two users — it has the potential to strengthen their relationship, through processes related to triadic closure, but it can also weaken their relationship, by drawing their communication away from one another and toward these newly formed connections. We analyze the interplay of these competing forces and relate the underlying issues to classical principles in sociology — specifically, the theories of balance, exchange, and betweenness. In the course of our analysis, we also provide novel approaches for dealing with a common methodological problem in studying ties on social media sites: the tremendous volatility of these ties over time makes it hard to compare one's results to simple baselines that assume static or stable ties, and hence we must develop a set of more complex baselines that takes this temporal behavior into account.
The Role of Comparison in the Development of Economic Theory

Our conference today on comparative economic history is in some clanger of rushing into the wide-open spaces of ambiguity, for the term is new, and to agree too quickly on its meaning and implications may not even be desirable. In order to avoid engaging in a mere game of definitions, this paper will deal first with three general types of comparison in relation to their bearing on problems of evidence. It will then review some of the chief uses to which these types of comparison have been put in building up our body of knowledge about Western economic history. The survey will close with particular reference to our own preindustrial stages of economic growth, when western Europe was, in our uncomplimentary phrase, an underdeveloped or backward area.
Strategies to Address Common Challenges When Teaching in an Active Learning Classroom

This chapter provides practical strategies for addressing common challenges that arise for teachers in active learning classrooms. Our strategies come from instructors with experience teaching in these environments.
Toward the Dynamical Convergence on the Jet Stream in Aquaplanet AGCMs

AbstractSystematic sensitivity of the jet position and intensity to horizontal model resolution is identified in several aquaplanet AGCMs, with the coarser resolution producing a more equatorward eddy-driven jet and a stronger upper-tropospheric jet intensity. As the resolution of the models increases to 50 km or finer, the jet position and intensity show signs of convergence within each model group. The mechanism for this convergence behavior is investigated using a hybrid Eulerian–Lagrangian finite-amplitude wave activity budget developed for the upper-tropospheric absolute vorticity. The results suggest that the poleward shift of the eddy-driven jet with higher resolution can be attributed to the smaller effective diffusivity of the model in the midlatitudes that allows more wave activity to survive the dissipation and to reach the subtropical critical latitude for wave breaking. The enhanced subtropical wave breaking and associated irreversible vorticity mixing act to maintain a more poleward peak of ...
Linkage between quantitative trait and marker loci : methods using all relative pairs

Relative-pair methods for detection of linkage between a quantitative trait and a marker locus have been proposed by a number of authors [e.g., Haseman and Elston, Behav Genet 3–19, 1972; Amos and Elston, Genet Epidemiol 349–360, 1989]. However, development of tests of significance that combine information from different types of relative pairs has been hampered by the presence of correlations between relative pairs from the same pedigree. In this paper, the methodology of generalized estimating equations is used to provide an estimate of the robust covariance matrix of the estimates of the set of relative-pair-type-specific regression parameters. Using this matrix, an asymptotically most powerful test of linkage which optimally combines the information contained in the different types of relative pairs is constructed. This test requires optimal weights that depend on unknown values of heritability and recombination fraction to be chosen a priori. However, simulations show that, in the regions of recombination fraction and heritability of practical interest, the power of the test does not depend strongly on the assumptions made when chosing the optimal weights; as a result, weights that depend only on the number of each type of relative pair and the variability of the marker identity-by-descent probabilities work well in practice. In addition, an approximation to the regression model leads to a simple approach to testing linkage in which only a single regression parameter is estimated from data containing different types of relative pairs. The resulting test is slightly less powerful than the test described above, but its computational simplicity and lack of dependence on a priori weighting schemes suggest potential usefulness in large linkage studies. © 1993 Wiley-Liss. Inc.
Quantification of margins and uncertainties: A probabilistic framework

Abstract Quantification of margins and uncertainties (QMU) was originally introduced as a framework for assessing confidence in nuclear weapons, and has since been extended to more general complex systems. We show that when uncertainties are strictly bounded, QMU is equivalent to a graphical model, provided confidence is identified with reliability one. In the more realistic case that uncertainties have long tails, we find that QMU confidence is not always a good proxy for reliability, as computed from the graphical model. We explore the possibility of defining QMU in terms of the graphical model, rather than through the original procedures. The new formalism, which we call probabilistic QMU, or pQMU, is fully probabilistic and mathematically consistent, and shows how QMU may be interpreted within the framework of system reliability theory.
Regulation of Mre11/Rad50 by Nbs1: effects on nucleotide-dependent DNA binding and association with ataxia-telangiectasia-like disorder mutant complexes.

The Mre11/Rad50 complex is a critical component of the cellular response to DNA double-strand breaks, in organisms ranging from archaebacteria to humans. In mammalian cells, Mre11/Rad50 (M/R) associates with a third component, Nbs1, that regulates its activities and is targeted by signaling pathways that initiate DNA damage-induced checkpoint responses. Mutations in the genes that encode Nbs1 and Mre11 are responsible for the human radiation sensitivity disorders Nijmegen breakage syndrome (NBS) and ataxia-telangiectasia-like disorder (ATLD), respectively, which are characterized by defective checkpoint responses and high levels of chromosomal abnormalities. Here we demonstrate nucleotide-dependent DNA binding by the human M/R complex that requires the Nbs1 protein and is specific for double-strand DNA duplexes. Efficient DNA binding is only observed with non-hydrolyzable analogs of ATP, suggesting that ATP hydrolysis normally effects DNA release. The alleles of MRE11 associated with ATLD and the C-terminal Nbs1 polypeptide associated with NBS were expressed with the other components and found to form triple complexes except in the case of ATLD 3/4, which exhibits variability in Nbs1 association. The ATLD 1/2, ATLD 3/4, and p70 M/R/N complexes exhibit nucleotide-dependent DNA binding and exonuclease activity equivalent to the wild-type enzyme, although the ATLD complexes both show reduced activity in endonuclease assays. Sedimentation equilibrium analysis of the recombinant human complexes indicates that Mre11 is a stable dimer, Mre11 and Nbs1 form a 1:1 complex, and both M/R and M/R/N form large multimeric assemblies of ∼1.2 MDa. Models of M/R/N stoichiometry in light of this and previous data are discussed.
Increasing the activity of affinity-purified DNA-binding proteins by adding high concentrations of nonspecific proteins.

A large decrease in the activity of two sequence-specific DNA-binding proteins implicated in transcription control was seen when these were affinity purified and assayed under standard conditions in electrophoretic mobility shift assays. Increasing the concentration of bovine serum albumin in the reaction mixtures from 0.1 to 5 mg/ml stimulated the DNA-binding activity of these affinity-purified proteins, human CREB (cyclic AMP response element binding protein) and MDBP (methylated DNA-binding protein), approximately 5-to more than 20-fold. In the case of affinity-purified MDBP, adding back the affinity flow-through fraction to the assay mixture gave similar extents of stimulation at much lower final protein concentrations. The specific DNA-binding activity of the affinity-purified CREB, but not that of MDBP, was also increased by adding a nonionic detergent to the binding reaction buffer although not as much. The large increase in the amount of MDBP.DNA complex seen upon supplementation of the affinity-purified MDBP with the affinity flow-through fraction or 5 mg/ml of BSA was shown to be due to stimulation, by nonspecific proteins, of specific complex formation and not to prevention of activity losses by adsorption or denaturation during the assay.
Challenges in multiple myeloma diagnosis and treatment

Although multiple myeloma (MM) remains an incurable disease, the advent of novel treatment paradigms has improved survival outcomes in the past two decades. This includes widespread use of high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT) and the development of the novel agents thalidomide, lenalidomide and bortezomib. The efficacy and tolerability of these novel agents have allowed for the exploration of continuous therapy approaches. Maintenance therapy after HDT-ASCT, for example, may help prolong progression-free survival by providing sustained control of residual disease. Trials are also under way to evaluate lenalidomide in patients with high-risk smoldering MM, with the aim of delaying progression to symptomatic MM. Other research is focusing on improving HDT-ASCT protocols and integrating novel agents, such as bortezomib, as an induction or consolidation therapy. Despite these advances, more effective strategies are needed, particularly for the management of older, less fit patients who are ineligible for HDT-ASCT. Preliminary results on the use of lenalidomide maintenance therapy in elderly patients are encouraging. Taken together, these observations indicate that in this era of novel agents, optimal treatment of MM requires a long-term perspective that focuses on providing sustained disease control while maintaining quality of life.
Toward understanding new feature request systems as participation architectures for supporting open innovation

Most research regarding innovation in open source software communities pertains to identifying supporting conditions for promoting code contribution as a way to innovate the software. Instead, this paper seeks to identify social and technological affordances of new feature request systems and their potential to support open innovation through integration of peripheral community members' ideas for advancing the software. Initial findings from the first of a planned study of multiple open source software communities are presented to identify attributes of effective participation architectures.
Supercooled Liquid Water Structure of a Shallow Orographic Cloud System in Southern Utah

Abstract A case study of an orographic cloud system that developed over the mountains or southern Utah is presented. The storm system contained supercooled liquid water over several hours, and produced almost no precipitation. Because of the high liquid water content, low ice particle concentrations, minimal precipitation, and long duration, the storm appears to have been a good candidate for seeding to augment precipitation. A preliminary analysis of the climatological frequency of orographic cloud systems over these mountains is discussed.
DIVERSITY IN CHILD CARE ASSISTANCE NEEDS: EMPLOYEE PROBLEMS, PREFERENCES, AND WORK‐RELATED OUTCOMES

This research examines employee background variables moderating problems with child care arrangements and variance in work-related attitudes and behaviors. Gender, household employment configuration, dependents' care profile, managerial status, and use of familial care arrangements help explain variance in child care problems, attitudes toward managing work and child care responsibilities, and the absence behavior of working parents in a public utility. The relationship between employee backgrounds and preferences for child care assistance is also examined. The study demonstrates that employees' child care needs are diverse, multi-faceted, and changing. It is suggested that organizations consider developing several packages of child care assistance policies that can be responsive to changes in the mix of employees' assistance needs and their work forces' demographics over time.
Corporate social responsibility and Islamic marketing: some basic lessons

The purpose of this study is to examine the concept of corporate social responsibility (CSR) and how it can inform research agenda in Islamic marketing using the tenets of the Qur’an. The study conducts an extensive review of the literature on corporate social responsibility, published works on the Qur’an and other Islamic teachings and suggests a means to enrich scholarship in Islamic marketing. The study finds a significant overlap between the principles of CSR and the teachings of Islam and suggests a means through which Islamic marketing could leverage this commonality. Even though this is a purely theoretical paper, it nonetheless makes a valid contribution. The study seeks to contribute to the theoretical foundation of Islamic marketing.
Selective Solubilization of a Protein Component of the Red Cell Membrane

Approximately 20 percent of the membrane-bound protein of erythrocyte ghosts can be solubilized and obtained free of other membrane components by dialysis against adenosine triphosphate and 2-mercaptoethanol. This protein forms one major band on polyacrylamide gels and a single boundary in free-boundary electrophoresis, and it undergoes polymerization in the presence of divalent cations to form coiled filaments visible by electron microscopy. Antibodies to this membrane protein react specifically with red blood cells or their membrane ghosts but do not react with serum, erythrocyte cytoplasm, or other blood cells. The functional role of this protein is unknown, but it appears to be involved in maintaiining the structure of the red cell membrane. We suggest that this protein be called Spectrin since it is obtained from membrane ghosts.
Pathogenesis of HIV in the gastrointestinal tract

Gut-associated lymphoid tissue (GALT) is an important site for early HIV replication and severe CD4+ T-cell depletion. Initiation of highly active antiretroviral therapy leads to incomplete suppression of viral replication and substantially delayed and only partial restoration of CD4+ T cells in GALT compared with peripheral blood. Persistent viral replication in GALT leads to replenishment and maintenance of viral reservoirs. Increased levels of inflammation, immune activation, and decreased levels of mucosal repair and regeneration contribute to enteropathy. Assessment of gut mucosal immune system will provide better insights into the efficacy of highly active antiretroviral therapy in immune restoration and suppression of viral reservoirs.
Bacteria with defective rho factors suppress the effects ofN mutations in bacteriophage λ

A prediction based on the model forN-gene function of bacteriophage λ proposed by Roberts (1971) is confirmed by showing that a λN − double mutant is able to grow in strains ofE. coli with defective rho transcription termination factors. The burst sizes for λN − in these strains range from 5 to 24% the burst sizes for λN + in the same strain. This low level of suppression is also evident in the levels of synthesis of the λ exonuclease and is consistent with other evidence that the defect in the rho factors of these strains is only partial. These strains do not suppress the effects of mutations in genesO, P andQ of λ nor in genes30 and43 of bacteriophage T4. The lack of suppression of λQ − is significant because theQ-gene product, like theN-gene product, is believed to function as an anti-terminator of λ transcription but at termination sites that may not require rho factor action.
Iontophoretic delivery of ALA provides a quantitative model for ALA pharmacokinetics and PpIX phototoxicity in human skin

Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) is increasingly employed for skin cancer, yet ALA dosing is crude. Using iontophoresis, we developed a rapid and quantifiable system for topical ALA delivery, with measurement of subsequent PpIX fluorescence and phototoxicity. ALA was iontophoresed from a 2% solution into upper inner arm skin of 13healthy volunteers. Six doses of ALA were delivered with a series of charges varying from 3-120 milliCoulombs (mC); four additional doses were given with a charge of 60 mC. Five hours post-iontophoresis, sites were irradiated with broad-band yellow-red light, the series of six ALA doses receiving 100 J/cm 2 , while the four identical doses received 6.25, 12.5, 25 and 50 J/cm 2 , respectively. Resultant erythema was measured by reflectance spectroscopy. The time course of PpIX fluorescence was ALA-dose-dependent. With charge ≤ 24 mC, PpIX fluorescence peaked at 3h and returned to zero at 9-10 h, whereas charges > 24 mC had a sustained peak at 5-10 h, falling to zero by 24h. Pre-irradiation, PpIX fluorescence correlated with ALA dose (r = 1.0). PpIX fluorescence fell immediately post-irradiation (p
Sum-free sets in vector spaces over GF(2)

Abstract A subset S of an abelian group G is said to be sum-free if whenever a, b ∈ S, then a + b ∉ S. A maximal sum-free (msf) set S in G is a sum-free set which is not properly contained in another sum-free subset of G. We consider only the case where G is the vector space (V(n) of dimension n over GF(2). We are concerned with the problem of determining all msf sets in V(n). It is well known that if S is a msf set then |S| ⩽ 2n − 1. We prove that there are no msf sets S in V(n) with 5 × 2n − 4 2 ⩽ s ⩽ [ (n − t) 2 ] . These methods suffice to construct msf sets of all possible cardinalities for n ⩽ 6. We also present some of the results of our computer searches for msf sets in V(n). Up to equivalence we found all msf-sets for n ⩽ 6. For n > 6 our searches used random sampling and, in this case, we find many more msf sets than our present methods of construction can account for.
Quantitative Determination of the Chemical Composition of Silica−Poly(norbornene) Nanocomposites

Nanoparticle hybrid materials consisting of a silica core surrounded by a poly(norbornene) brush have been prepared by ring opening metathesis polymerization (ROMP). A quantitative determination of each stage of composite formation has been accomplished, including a determination of the density of surface-bound functional groups, catalyst molecules, and polymer chains. This analysis has enabled the determination of the reaction efficiency between the catalyst and the surface-bound functional groups as well as the determination of the fraction of metal-mediating species that initiate a polymer chain. Control of the chain density was demonstrated by two methods: the use of controlled reaction times between the catalyst and the surface, and the variation of the surface functional group density. Polymer chain densities resulting from composites prepared with different tether structures will also be reported. The resulting brush densities were found to span a wide range, including those previously reported for polymer layers formed by adsorption, grafting of preformed polymer chains, and surface-initiated polymerization (SIP).
Gene transcript profiling in aging research

Abstract Advances in biotechnology have led to methods for quantifying the relative concentrations of thousands of mRNAs in parallel. While these are powerful methods that can be used for both hypothesis testing and hypothesis generation, gene transcript profiling has some limitations as a tool to study aging. These include the difficulty in separating effects of aging from analytical and biological variability, statistical problems associated with simultaneous determination of so many different gene transcripts, and uncertainty about the functional significance of changes in mRNA concentrations. In this review, these issues are discussed with a focus on two methods for profiling mRNAs–serial analysis of gene expression (SAGE) and DNA arrays.
The biosynthesis and biological function of diphthamide.

AbstractEukaryotic and archaeal elongation factor 2 contains a unique post-translationally modified histidine residue, named diphthamide. Genetic and biochemical studies have revealed that diphthamide biosynthesis involves a multi-step pathway that is evolutionally conserved among lower and higher eukaryotes. During certain bacterial infections, diphthamide is specifically recognized by bacterial toxins, including diphtheria toxin, Pseudomonas exotoxin A and cholix toxin. Although the pathological relevance is well studied, the physiological function of diphthamide is still poorly understood. Recently, many new interesting developments in understanding the biosynthesis have been reported. Here, we review the current understanding of the biosynthesis and biological function of diphthamide.
HOME CANNING OF FOOD: EVALUATION OF CURRENT RECOMMENDED METHODS

Recommended procedures for the home canning of low-acid foods were evaluated for safety. Heat penetration rates were determined and Fo, values calculated using a DEC PDP8e computer. This unique system provided almost instant results and enabled the collection of considerable data. All of the processes evaluated resulted in adequate F0 values except the method suggested for strained pumpkin or squash. This procedure did not provide an adequate heat treatment. Process times at 15 psig for several low-acid foods were developed and evaluated. These results, obtained under home-processing conditions, indicate that shorter process times are possible with foods that heat by convection. Products that heat by conduction or both mechanisms appear to require the same amount of time at 15 psig as at 10 psig. This system (15 psig) will be further evaluated.
Reinvestigation of apparent 1,4-addition and rearrangement in the reactions of quinolines with organolithium compounds

Abstract The recent claim of Otsuji, Yutani and Imoto7 that both n-butyllithium and phenyllithium gave isolable 1,4-adducts with lepidine (4-methylquinoline) has been reinvestigated. Such adducts were reportedly captured in the form of their N-ethoxycarbonyl derivatives. In the present study these same N-ethoxycarbonyl derivatives have been prepared and examined by NMR and IR spectroscopy. Moreover, the corresponding N-(ethoxycarbonyl)-n-butyldihydro and N-(ethoxycarbonyl)phenyldihydro derivatives have now been prepared from 2-deuteriolepidine. An analysis of the spectroscopic data leads to the clear conclusion that all such derivatives are really 2-substituted-1,2-dihydrolepidines. Consequently, all the discussion published in ref. 7, concerning a 1,4-addition of organolithium reagents to the quinoline nucleus and the subsequent rearrangement to the 1,2-adduct, becomes unfounded.
Soil sampling procedures for monitoring potassium distribution in grazed pastures

Nutrient redistribution in grazed pastures occurs primarily via deposition of excreta by animals. Because this redistribution is generally not uniform, a composite sample of randomly collected soil cores may not reflect the nutrient status of much of the pasture. To address this limitation, zonal soil sampling, with zones determined by distance from shade, water, and supplemental feeders (lounging areas), has been proposed as an alternative sampling strategy. This experimentwas conducted to evaluate the potential of zonal soil sampling formonitoring extractable K distribution in grazed pastures. Utility of the zonal approach was evaluated by comparing it with a more rigorus, but less practical transect sampling procedure [...]
Universal 2-layered noniterative perceptron for recognizing closely related patterns

As we published in the last eight years, when the analog-to- binary mapping of any M training CLASS patterns are not PLI, then a one-layered preceptron (OLP) just cannot learn this mapping at all no matter what learning rule we use, because the solution of the connection matrix does not exist. However, as we derived form this PLI condition, which is the most general separability condition for an OLP, a PCTLP system can still be used to separate these closely relate and 'inseparable' patterns according to the targeted outputs Vm. This paper repots the theory and the design of this NOVEL PCTLP system.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
DISCUSSIONS ABOUT END OF LIFE (EOL) CARE AND PROGNOSTICATION IN THE NICU.• 231

The SUPPORT study, a large multicenter study of EOL care in adult ICUs, showed that, even for very high-risk patients, doctors were unlikely to discuss DNR orders until 24-48h prior to death. We wondered whether there were similar patterns in discussions about EOL care or DNR orders in NICUs.METHODS: Babies were eligible for the study if they met ≥1 of the following criteria: <750g, congenital anomalies, grade IV IVH, asphyxia, chronic lung disease. We asked MDs to estimate each baby's chance of survival, anticipated quality of life on a 1-10 scale, and likelihood of developing cognitive or motor problems. We then asked whether there had been a discussion about DNR or EOL care prior to the baby's last day of life. RESULTS: 260/1204 (21%) admissions to the NICU met eligibility criteria. These babies accounted for 97% of deaths. We interviewed MDs in 138 (53%) of these cases. MDs had discussed EOL care prior to the last day of life in 46(33%) cases. Comparing babies about whom there was or was not such a discussion, there was no difference in MD assessments of the baby's likelihood of survival to discharge, of developing cognitive or motor problems, or of anticipated quality of life. 24/138 (17%) babies died. 17 (71%) babies who died did not receive CPR at the time of death. 76% of babies about whom there was a discussion of EOL options survived. There was discussion about EOL options about 11/24 (46%) of babies who died. CONCLUSIONS: For most babies who don't get CPR, there hasn't been discussion of DNR prior to the last day of life. Most babies about whom there is some discussion of DNR don't die. Prognostic estimates do not correlate well with discussions of EOL care in these 2 NICUs. In deciding which parents should discuss EOL treatment options, prognostic assessments are only part of the puzzle. Other factors seem to drive many such decisions.
Role of Arachidonate Lipoxygenase and Cyclooxygenase Products in Insulin and Glucagon Secretion From Rat Pancreatic Islets

Rat pancreatic islets incubated in nutrient medium were used to study the role of endogenous arachidonic acid metabolism in pancreatic hormone secretion. Both glucose and fetal calf serum stimulated radioimmunoassayable PGE2 production and insulin secretion from islets. These effects were abolished by the phospholipase inhibitor p-bromophenacyl bromide or by concurrent inhibition of cyclooxygenase and lipoxygenase by flurbiprofen plus nordihydroguaiaretic acid (NDGA), respectively. Bromophenacyl bromide also inhibited glucagon secretion. When used alone, flurbiprofen caused a significant enhancement of glucose-induced insulin secretion that was attributed to reactive stimulation of lipoxygenase-product formation rather than to selective cyclooxygenase inhibition. NDGA given alone in the presence of stimulatory concentrations of glucose suppressed the normal eight-fold rise in insulin secretion, but caused a marked enhancement in glucagon secretion that could be overcome by simultaneous inclusion of flurbiprofen. We concluded that: (1) Increased metabolism of arachidonic acid in pancreatic islets amplifies the secretion of insulin and glucagon. (2) The lipoxygenase as well as the cyclooxygenase pathways of arachidonate metabolism participate in the amplification of insulin secretion. (3) The observations made in this study are inconclusive with respect to the involvement of the lipoxygenase and cyclooxygenase pathways in glucagon secretion; an inhibitory role for lipoxygenase pathway products is suggested.
The influence of age and gender on left ventricular response to supine exercise in asymptomatic normal subjects.

The performance of normal subjects during radionuclide ventriculography has been related to age, but the combined effects of age and sex on exercise ventricular function are not well described. We studied 55 normal volunteers, 27 men (age = 30 ± 10 years) and 28 women (age = 33 ± 14 years), free of chest pain syndromes, during supine rest/exercise radionuclide ventriculography performed to fatigue. Resting left ventricular ejection fraction did not differ between male and female subjects (64 ± 5.4 vs 64 ± 6.1; p = NS). Both the peak left ventricular ejection fraction (78 ± 4.4 vs 72 ± 9.2; p < 0.001) and the change in ejection fraction with exercise (14 ± 4.0 vs 7.9 ± 7.0; p < 0.001) were significantly greater in men compared to respective values in women. Regression analysis showed that sex (r = 0.51; p < 0.001) but not age (r = −0.18; p = 0.19) was a significant predictor of change in ejection fraction with exercise. Data on left ventricular volume response to exercise, available in 43 subjects, revealed that men had a greater percentage of decline in end-systolic volume with exercise than women (−47 ± 15 vs −24 ± 26; p < 0.001). It is concluded that sex exerts a significant influence on normal left ventricular response to fatigue-limited supine exercise and that the gender difference is mediated, in part, by left ventricular end-systolic volume response to exercise.
Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS)

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first separated into polar and non-polar fractions by a liquid-liquid phase extraction, and partially purified to facilitate downstream analysis. Both aqueous (polar metabolites) and organic (non-polar metabolites) phases of the initial extraction are processed to survey a broad range of metabolites. Metabolites are separated by different liquid chromatography methods based upon their partition properties. In this method, we present microflow ultra-performance (UP)LC methods, but the protocol is scalable to higher flows and lower pressures. Introduction into the mass spectrometer can be through either general or compound optimized source conditions. Detection of a broad range of ions is carried out in full scan mode in both positive and negative mode over a broad m/z range using high resolution on a recently calibrated instrument. Label-free differential analysis is carried out on bioinformatics platforms. Applications of this approach include metabolic pathway screening, biomarker discovery, and drug development.
Dissociation of Automatic and Strategic Lexical-Semantics: Functional Magnetic Resonance Imaging Evidence for Differing Roles of Multiple Frontotemporal Regions

Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and target being manipulated. Study 1 demonstrated automatic semantic priming in the left mid-fusiform gyrus (mid-FFG) and strategic semantic priming in five regions: left middle temporal gyrus (MTG), bilateral anterior cingulate, anterior left inferior prefrontal cortex (aLIPC), and posterior LIPC (pLIPC). These priming effects were explored in more detail in two subsequent studies. Study 2 replicated the automatic priming effect in mid-FFG and demonstrated that automatic priming in this region is preferential for the semantic domain. Study 3 demonstrated a neural dissociation in regions contributing to the strategic semantic priming effect. Strategic semantic facilitation was observed in the aLIPC and MTG, whereas strategic semantic inhibition was observed in the pLIPC and anterior cingulate. These studies provide reproducible evidence for a neural dissociation between three well established components of the lexical-semantic processing system.
A sirtuin link between metabolism and heart disease

The sirtuins (SIRTs) have gained preeminence for their roles in the response to caloric restriction and the regulation of aging and lifespan. A new study now identifies gene promoters that bind the transcription factor AP1 as targets for silencing by SIRT6, providing possible links between SIRT6 deficiency and dysregulation of insulin-like growth factor signaling, hypertrophic cardiomyopathy and heart failure (pages 1643-1650).
A multilevel formulation of the method of moments (EM scattering)

The modeling of electromagnetic scattering and radiation problems using the method of moments (MoM) is limited to resonant frequencies because of the extensive computational requirements of solving large matrix equations. In this study, a multilevel formulation of MoM which allows substantial computational savings and, thus, extends the application of MoM to higher frequencies is presented. Using a hierarchy of discretization levels, the multilevel technique extracts different modal components of the solution by focusing on a specific portion of the spectrum of the solution at a given level. The fundamental features of this process for the MoM solution of the electric field integral equation (EFIE) are developed and implemented. This multilevel MoM allows the rapid evaluation of the current distributions on a variety of 2-D scatterers with thousands of unknowns in fewer than ten cycles and in fractions of the normal CPU times. The method is stable, fast, suitable for multiple excitations, and adaptable as a 'solve' module for almost any MoM code. >
ON THE RELATION OF THE ORGANISMS IN THE TUNICA VAGINALIS OF ANIMALS INOCULATED WITH MEXICAN TYPHUS TO RICKETTSIA PROWAZEKI AND TO THE CAUSATIVE AGENT OF THAT DISEASE

Healthy lice became infected with Rickettsia prowazeki after feeding on monkeys inoculated with a strain of Mexican typhus. The same result was obtained in 100 per cent of lice by rectal inoculation of an emulsion of tunica vaginalis of guinea pigs reacting to the same strain. In the tunica vaginalis of guinea pigs and rats inoculated intraperitoneally with an emulsion of lice containing Rickettsia prowazeki the intracellular organism constantly associated with the passage strain appeared regularly. Rickettsia prowazeki found in lice and the organism constantly present in the tunica of guinea pigs and rats reacting to our strain of tabardillo are indistinguishable morphologically and tinctorially and their mode of intracellular multiplication is alike in every respect. It is concluded that they are identical. This organism is constantly associated with the causative agent of Mexican typhus, both in mammals and in lice, and all of our attempts to separate them have failed.
Comparative effects of pentylenetetrazol on the sensory responsiveness of lateral geniculate and reticular formation neurons.

Abstract The responses of bulbar and mesencephalic reticular formation (MRF) neurons to visual, auditory and/or somatosensory stimuli were considerably enhanced after subconvulsant doses of pentylenetetrazol (PTZ) in a similar fashion suggesting a general action of PTZ on reticular formation (RF) neurons. PTZ enhanced MRF responses evoked by electrical stimuli in the lateral geniculate nucleus (LGN) or cochlear nucleus but only modestly enhanced LGN neuronal responses. These findings indicate that the effects of this convulsant on the first brain sensory ‘relay’ nuclei and primary sensory receptors do not appear to be sufficient to account for the extensive PTZ-induced enhancement of RF neuronal responses, and direct effects of PTZ on the reticular formation may play a major role in this enhancement.
Invitations for Partisan Identification: Attempts to Court Latino Voters Through Televised Latino-Oriented Political Advertisements, 1984–2000

By the year 2050, Latinos will represent the dominant ethnic minority in the United States, and researchers are just beginning to examine the campaign messages targeted to this voting bloc. This article employs identification theory to understand the rhetorical approaches used in campaign advertisements designed for these voters. Through a content analysis of campaign spots targeted to Latinos over four presidential elections (1984, 1988, 1996, 2000), we find that the invitations for party identification sent to this group tend to be positive, focus on the Latino (not the candidate), and depict Latinos as an emergent force in American politics. In trying to foster identification from this desirable voting population, it appears that campaign forces encourage Latinos to view themselves, and politics, as valuable and consequential—a marked alternative to most advertising strategies at the close of the 20th century.
CALFED and the quest for optimal institutional fragmentation

Abstract Environmental problems are typically addressed by fragmented governance institutions. Fragmentation can present serious barriers to resolving environmental conflicts, but can also offer benefits. The CALFED experience should not be seen as demonstrating that unified governance is necessarily superior. Rather, it is a reminder that a fragmented governance strategy is not likely to succeed without strong leadership and tools for resolving inter-agency conflicts.
Influence of irradiation temperature and dose gradients on the microstructural evolution in neutron-irradiated 316SS

A cold worked 316SS baffle bolt was extracted from the Tihange pressurized water reactor and sectioned at three different positions. The temperature and dose at the 1-mm bolt head position were 593 K and 19.5 dpa respectively, whereas at two shank positions the temperature and dose was 616 K and 12.2 dpa at the 25-mm position and 606 K and 7.5 dpa at the 55-mm position. Microstructural characterization revealed that small faulted dislocation loops and cavities were visible at each position, but the cavities were most prominent at the two shank positions. Measurable swelling exists in the shank portions of this particular bolt, and accompanying this swelling is the retention of very high levels of hydrogen absorbed from the environment. The observation of cavities in the CW 316SS at temperatures and doses relevant to LWR conditions has important implications for pressurized water reactors since SA 304SS plates surround the bolts, a steel that usually swells earlier due to its lower incubation period for swelling.
Rural Women, Anti-Poverty Strategies, and Black Feminist Thought

Rural U.S. poverty rates have been persistently high. Market-based anti-poverty strategies, specifically microenterprise programs, have gained currency as a feasible avenue for moving women out of poverty. While rural women may share some commonality, homogeneity among rural women is often assumed in poverty scholarship. It is imperative that poverty scholars contribute to closing the gap between theoretical explanations and the actually experiences of poverty among individuals occupying different social locations. As researchers address this gap, this article argues for the value of integrating two important components consistent with black feminist epistemology: (1) an intersectionality perspective, and (2) the voices of the local actors/stakeholders. This article concludes that without a purposeful examination of individuals located at the intersection of race/ethnicity, gender, and/or class; even carefully formulated policy can inadvertently discriminate against or benefit some women more than others.
Computerized practice tests and effects on in-class exams

Twenty-eight introductory psychology college students volunteered to learn a technique that might help improve their in-class, multiple-choice exam performance. Two 12-question multiple-choice tests with detailed feedback were presented on a personal computer. There were two types of feedback.Separate feedback consisted of a brief statement indicating why a specific answer was either right or wrong.Combined feedback consisted of the four separate feedbacks combined into a single paragraph. Eighteen students from another introductory class, who did not get to participate in these practice tests, served as a control. A within-group comparison of the two feedback formats showed differences in degree of improvement dependent on the level of achievement by students on the first in-class exam. When compared with data from the control group, the results show significant improvement by the low-level participants on the second in-class exam (p<.01).
Reimagining Japanese education: borders, transfers, circulations, and the comparative

edited by David Blake Willis and Jeremy Rappleye, Oxford, Symposium Books, 2011, 288 pp., £24.00 (paperback), ISBN 978-1-873927-51-9 This book is an important volume and deserves attention by not o...
Magnetic properties of Dy-Y superlattice structures☆

Abstract Molecular beam epitaxy has been used to produce single-crystal superlattices of alternating dysprosium and yttrium layers with thicknesses comparable to the intrinsic magnetic periodicity of Dy. The superlattices exhibit a feature in the bulk magnetization corresponding to the spiral-phase transition in Dy, but no ferromagnetic transition. Rather, zero-field-cooled data show a broad maximum that is not observed on field cooling. The position of the maximum depends on yttrium layer thickness. These results are discussed in terms of an interruption of the spiral by the non-magnetic layers.
Advanced Lung Cancer Treated with Cyclophosphamide

Seventy-eight patients with locally recurrent or disseminated lung cancer were treated with cyclophosphamide therapy. Only eight patients showed objective tumor regression. Five of the objective responses occurred in patients with small cell anaplastic carcinoma and three in patients with squamous carcinoma. No objective responses were seen in adenocarcinoma or alveolar cell carcinoma. An additional 26 patients manifested a stable or subjectively improved status during therapy. Hemorrhagic cystitis was seen in six of 36 patients receiving the drug orally but in none of those receiving monthly intravenous courses. Hematologic toxicity was acceptable though there was one death from sepsis associated with leukopenia. There was no evidence that life was prolonged by this drug. Because there seemed to be frequent subjective benefit, we recommend that symptomatic patients with recurrent or disseminated lung cancer receive monthly intravenous courses of cyclophosphamide as palliative therapy.
Two children's anticipations, beliefs, and motivations

This paper discusses the roles played by anticipation, belief, and motivation in two young children's problem solving activity. It is argued that a solver's beliefs and motivations are intimately related. The analysis also identifies an increasingly global hierarchy of anticipations corresponding to specific conceptual structures or problem representations, heuristics, and beliefs. Analogies drawn from the philosophy of science and from the field of artificial intelligence are used to illustrate that the discussion of the two children's behaviors may have some generality.