cssi/SciSciGPT-SciSciNet huggingface dataset:
Pagoda: a dynamic overlay network for routing, data management, and multicasting

The tremendous growth of public interest in peer-to-peer systems in recent years has initiated a lot of research work on how to design efficient and robust overlay networks for these systems. While a large collection of scalable peer-to-peer overlay networks has been proposed in recent years, many fundamental questions have remained open. Some of these are: Is it possible to design deterministic peer-to-peer overlay networks with properties comparable to randomized peer-to-peer systems?How can peers of non-uniform bandwidth be organized in an overlay network?We propose a dynamic overlay network called Pagoda that provides solutions to both of these problems. The Pagoda network has a constant degree, a logarithmic diameter, and a 1/logarithmic expansion, and therefore matches the properties of the best randomized overlay networks known so far. However, in contrast to these networks, the Pagoda is deterministic and therefore guarantees these properties. The Pagoda can be used to organize both nodes with uniform bandwidth and nodes with non-uniform bandwidth. For nodes with uniform bandwidth, any node insertion or deletion can be executed with logarithmic work, and for nodes with non-uniform bandwidth, any node insertion and deletion can be executed with polylogarithmic work. Moreover, the Pagoda overlay network can route arbitrary multicast problems with a congestion that is within a logarithmic factor of what a best possible overlay network of logarithmic degree for that particular multicast problem can achieve, even though the Pagoda is a constant degree network. This holds even for nodes of arbitrary non-uniform bandwidths. We also show that the Pagoda network can be used for efficient data management.
Fibroblast growth factor increases TNF alpha-mediated prostaglandin E2 production and TNF alpha receptor expression in human fibroblasts.

To examine the possible role of basic fibroblast growth factor (FGF) in regulating the effects of TNFα, we tested the effect of FGF on TNFα-mediated PGE2 production and TNFα receptor expression in human fibroblasts. We found that, while FGF alone had no effect on PGE2 production, it enhanced the amount of PGE2 produced in response to TNFα between 3 and 11-fold. FGF stimulated TNFα-induced PGE2 production independent of potential TNFα-mediated IL-1 production, as neither anti-IL-1 mAbs nor IL-1 receptor antagonist protein (IRAP) inhibited TNFα induced-PGE2 production or the stimulatory effect of FGF. A one minute exposure of cells to FGF prior to removal was sufficient to significantly enhance TNFα-induced PGE2 production; the maximal FGF effect was reached after a 6 h preincubation. We also found that FGF significantly enhanced TNFα receptor expression. Untreated fibroblasts expressed ≈3,900 receptors/cell, while cells treated with FGF for 6h expressed ≈9,500 receptors/cell, a 2.4-fold increase in receptor number; there was no apparent change in affinity for TNFα (Kd 3.8×10−11 M). The FGF-mediated increase in TNFα receptor expression and TNFα-mediated PGE2 production could be abolished by FGF mAbs, indicating a specific FGF effect. These results show that FGF increases TNFα receptor expression and suggest that this may account, at least in part, for the ability of FGF to enhance TNFα-mediated PGE2 production in human fibroblasts.
Administration of NF-κB decoy inhibits pancreatic activation of NF-κB and prevents diabetogenesis by alloxan in mice

SPECIFIC AIMSIn this study, we tested the hypothesis that nuclear factor κB (NF-κB) activation is the key event involved in the initiation of diabetogenesis using alloxan-induced diabetes as a model. Our specific aims are to determine whether pancreatic NF-κB activation induced by alloxan can be blocked by intravenous (i.v.) injection of NF-κB decoy (i.e., synthetic oligodeoxynucleotides of NF-κB DNA binding site) and to monitor whether inhibition of NF-κB activation by the decoy can prevent the alloxan-induced diabetes in mice.PRINCIPAL FINDINGS1. Pretreatment with NF-κB-specific oligodeoxynucleotides (NF-κB decoy) blocked alloxan-induced NF-κB activation in the pancreas in vivoUsing the methods previously reported by Miagkov et al., we synthesized a NF-κB decoy (5′-CTGGGGACTTTCCAT-3′) as phosphorothioate. A scrambled sequence of the decoy (SCR, 5′-TAACCGACTTTGCAT-3′) was prepared as control substance. Double-stranded NF-κB decoy or SCR was dissolved in TransIT In vivo Gene Delivery System (Panvera, WI) ...
Decrease in Stroop Effect by Reducing Semantic Interference

Ss were instructed to hold the incongruous color words upside down while naming the color in which the word was printed. The color-naming time was significantly shorter than that of the conventiona...
Modification of lysine residues of pepsinogen with dicarboxylic anhydrides.

Abstract Porcine pepsinogen was modified chemically with citraconic, maleic and itaconic anhydrides, and the properties of the derivatives were studied as to the nature and extent of the structural changes in the protein. Modification of the zymogen with citraconic and maleic anhydrides was shown to be partially reversible; the citraconyl and maleyl groups were readily removed under mild acidic conditions. At pH 2.0, 77% and 50% of the potential pepsin activity could be recovered on activation of the citraconyl- and maleylpepsinogens. Itaconylpepsinogen regained only 25% of the potential pepsin activity. From optical rotatory dispersion and circular dichroism measurements it was apparent that a conformational change had occurred with all three pepsinogen derivatives as reflected by a decrease of λ c from 228 to 216–222 nm and au increase of the levorotation, [α] 366 . The reappearance of potential pepsin activity parallels the change of the optical rotatory properties.
Inelastic light scattering studies of chemical vapor deposition systems

Raman and resonance fluorescence spectra, determined by inelastic light scattering measurements, can be used to probe a gas phase chemical reaction in situ during the reaction. The data can be interpreted to identify the molecular species in the reaction and to determine molecular concentrations and temperatures as well as their profiles. In this paper first a brief review of the technique and necessary apparatus for its implementation is given. Then studies of W and epitaxial Si chemical vapor deposition systems are described. In the Si deposition system, the production of an intermediate product SiCl2 by a gas phase homogeneous reaction is observed for the first time. In the W deposition system, the profiles of input gas (WF6) partial pressure are presented and correlated with film growth rates.
A time-dependent dusty gas dynamic model of axisymmetric cometary jets

The first results of a new time-dependent, axisymmetric dusty gas dynamical model of inner cometary atmospheres are presented. The model solves the coupled, time-dependent continuity, momentum, and energy equations for a gas-dust mixture between the nucleus surface and 100 km using a 40 x 40 axisymmetric grid structure. The timedependent multidimensional partial differential equation system was solved with a new numerical technique employing a second-order accurate Godunov-type scheme with dimensional splitting. It is found that narrow axisymmetric jets generate a subsolar dust spike and a jet cone, where a significant amount of the jet ejecta is accumulated. This subsolar dust spike has not been predicted on earlier calculations. The opening angle of the jet cone depends on the jet strength and it also varies during the time-dependent phase of the jet. For weak jets the steady-state half-opening angle is about 50 ° . In the case of the strong jets the jet cone extends to the nightside in good agreement with the Giotto imaging results. © 1990 Academic Press, Inc.
GW quasiparticle corrections to the LDA+U/GGA+U electronic structure of bcc hydrogen

In this paper, we study the quasiparticle electronic structure of atomic hydrogen in the body-centered cubic structure for various densities. We employ the $GW$ approach to compute the electron self energy. For this model system, we use the local density approximation $(\mathrm{LDA})+U$/generalized gradient approximation $(\mathrm{GGA})+U$ method as the mean-field solution starting point, which is known to work better than LDA/GGA for systems with strongly correlated electrons. In the low-density insulating phase, we find that the calculated $GW$ quasiparticle gap is quite insensitive to the value of the on-site repulsive $U$ employed over a wide range of physically reasonable values. Moreover, our result for the electronic gap agrees with the measured difference between ionization energy and electron affinity in the atomic limit.
Routine training is not enough: structured training in family planning and abortion improves residents' competency scores and intentions to provide abortion after graduation more than ad hoc training.

Abstract Background Abortion provision remains threatened by the paucity of physicians trained to provide them. Lack of training during residency has been cited by obstetrician and gynecologist (ob-gyn) physicians as a reason for not including abortion in their practice. Study Design We administered surveys on interest, competency and intention to provide abortions to two groups of ob-gyn residents: one experiencing a new comprehensive and structured family planning rotation, and another group at our affiliate hospital's residency program receiving “ad hoc” training during their routine gynecology rotations. Surveys were anonymous and blinded to investigator. Results The structured family planning rotation group compared to the ad hoc group reported significantly increased competency score using a Likert scale in manual vacuum aspiration (MVA) (4.5 vs. 1; p=.003) and had a higher proportion reporting intent to provide office MVA postresidency (100% vs. 39%; p=.01) and being trained to 22.5 weeks' vs. 12 weeks' gestation (p=.005). In bivariate analysis, competency in MVA was associated with higher intentions to provide MVA after residency (p=.007). Conclusions A structured rotation in family planning and abortion for obstetrics/gynecology residents results in increases in competency and intentions to provide abortion, and an association between the two. In-hospital structured training proved to be superior to ad hoc training in our affiliate institution in improving competency and intention to provide abortion after residency.
The MAC (Multi-Axial Correcting) Monolateral External Fixation System (Biomet/EBI) Technique: An Easier Way to Correct Deformity

The MAC (Multi-Axial Correcting) Monolateral External Fixation System (Biomet, Warsaw, IN) permits simplified acute or gradual deformity correction by applying a mechanical hinge directly to the center of rotation of angulation (CORA) with stable fixation above and below the CORA. Although application of the hinge on the CORA should correct deformity completely, failure to apply the hinge correctly may lead to residual deformity, which can be corrected by use of the MAC fixation system's 2 planes of angulation, 2 planes of translation, compression, distraction, and rotation without returning to the operating room, making time-consuming adjustments, or using computer-based systems. The MAC can be applied anywhere on the extremities from the shoulder to the hand and the hip to the foot. Office visits are similarly simple. Each visit requires only measurement of length and angular deformity on the anteroposterior and lateral x-rays. Correction is accomplished by sequentially turning one screw to lengthen 0.25 mm 4 times per day (1 mm per d), then turning another screw to correct angulation 1° 4 times per day (4°/d). Complex computer calculations are not needed for deformity correction. In this work the simple application technique and the concepts of application of the MAC are explained. It also provides some examples of application, including Blount's syndrome, femur varus, and shortness correcting length and angulation simultaneously, and 2-level correction of clubfoot.
Treatment of chronic hepatitis B

Treatment of chronic hepatitis B has improved substantially over the past five years. Pegylated interferon alpha2a and entecavir have been approved by the FDA and joined the armamentarium of therapies that includes inteferon alpha (IFN-alpha), lamivudine, and adefovir dipivoxil. Several key questions come to mind regarding treatment. Who should receive treatment? Which agent should they be given? How long should treatment last? Treatment is indicated for patients with a high pretreatment alanine aminotransferase level, detectable HBV DNA, and active inflammation on liver biopsy. When selecting an agent, the likelihood of achieving a sustained response should be weighed against long-term risks. IFN-alpha, lamivudine, and adefovir dipivoxil are equally efficacious; however, even though IFN-alpha and pegylated IFN-alpha have a durable response, both are associated with unpleasant side effects. Long-term lamivudine therapy has a high rate of drug resistance compared with adefovir dipivoxil, which has a low rate of drug resistance and a small risk of reversible nephrotoxicity. Entecavir reduces HBV load more effectively than the other therapies, but it is associated with increased drug resistance in patients with lamivudine-resistant HBV. The key to therapy seems to be some combination of therapies--both existing and those in development--that has yet to be determined.
Interactions between ubiquinones and vitamins in membranes and cells

Abstract The interaction between ubiquinones and vitamin E was studied in the inner membranes of rat liver mitochondria, liposomes and human erythrocyte plasma membranes. Free radicals were produced by addition of exogenous oxidants, and their reaction with chromanols and ubiquinone was followed by ESR and HPLC. Membranes were made deficient in ubiquinone but sufficient in α-tocopherol and were reconstituted with added ubiquinone. With these membrane preparations it was shown that (i) in the inner mitochondrial membranes there is a requirement for ubiquinone in the enzymatic recycling of vitamin E; (ii) succinate-ubiquinone reductase incorporated in liposomes cannot protect vitamin E in the absence of ubiquinone and (iii) in human erythrocyte plasma membranes protection against the loss of vitamin E can be provided by NADH-cytochrome-b 5 -dependent enzymatic recycling. We conclude that ubiquinonols (ubisemiquinones) reduce vitamin E through electron transport.
Mathematical programming formulation for scheduling of batch operations based on nonuniform time discretization

A flexible formulation for handling a wide range of short-term scheduling problems arising in multi-product/multipurpose batch chemical plants is presented. Time is directly used to model events arising in the schedule and thus use of binary variables over periods during which no changes in system state occur is avoided. Batch processes involving a variety of operational complexities can be readily represented. The scheduling problem is formulated as a mixed integer nonlinear program (MINLP). The resulting model can be simplified via exact linearization to yield a mixed integer bilinear program (MIBLP) in which the only nonlinearity arises in the objective function as a product of continuous variables. A preliminary computational comparison is made against a uniform time discretization formulation.
Investigating the effects of using different nursery sizing policies on performance

In this paper, we investigate the effects of using three different nursery sizing policies on overall and garbage collection performances. As part of our investigation, we modify the parallel generational collector in HotSpot to support a fixed ratio policy and heap availability policy (similar to that used in Appel collectors), in addition to its GC Ergonomics policy. We then compare the performances of 16 large and small multithreaded Java benchmarks; each is given a reasonably sized heap and utilizes all three policies. The result of our investigation indicates that many benchmarks are sensitive to heap sizing policies, resulting in overall performance differences that can range from 1 percent to 36 percents. We also find that in our server application benchmarks, more than one policy may be needed. As a preliminary study, we introduce a hybrid policy that uses one policy when the heap space is plentiful to yield optimal performance and then switches to a different policy to improve survivability and yield more graceful performance degradation under heavy memory pressure.
Measurements of the subpixel sensitivity for a backside-illuminated CCD

This paper presents results from a measurement program designed to investigate the variations in sensitivity of focal plane arrays on a sub-pixel scale. High-resolution measurements have previously been reported for a front- illuminated CCD device. New measurements are now provided on the sensitivity variations with in a single pixel of a backside-illuminated CCD. The measurements were made using a stable broadband light source and two high-precision translation stages. The pixel scans have been performed using 4 different filters (3 broadband and 1 narrowband). The results for each spectral region are presented.19
Cigarette smoking and age at diagnosis of inflammatory bowel disease.

Objectives: The incidence and age of onset of inflammatory bowel disease (IBD) appear to be changing. The aim of this study was to determine whether the prevalence of cigarette smoking differs among patients with Crohn’s disease (CD) or ulcerative colitis (UC) at the time of diagnosis compared with the general population and whether smoking history is related to the type and age of IBD onset. Methods: Prevalence rates of smoking at the time of IBD diagnosis were compared between patients with CD and UC from the IBD Center at the University of Pittsburgh Medical Center versus age-, gender-, and time period-adjusted rates in the Pennsylvania general population. Analyses also were stratified by gender and diagnoses before and after 40 years of age, i.e., early and late onset. Results: There were 263 IBD patients (144 UC patients and 119 CD patients) seen in the IBD center between August 2000 and December 2002. The prevalence of active smoking was significantly higher at diagnosis in CD patients compared with the Pennsylvania general population (33% versus 24%, P = 0.04), particularly in those with CD onset at 40 years of age or later (47% versus 27%, P = 0.005). In contrast, smoking prevalence was significantly lower in UC patients than the general population (9% versus 28%, P < 0.0001), particularly among those with UC onset before the age of 40 years (6% versus 27%, P < 0.0001). Smoking cessation was associated with an approximate, but nonsignificant, 3-fold higher likelihood of late-onset UC compared with CD. Conclusions: Cigarette smoking is associated with the development of late-onset CD and is protective against developing UC at any age, particularly early onset. Former smoking is associated with a high likelihood of developing late-onset UC, but not CD.
Oxidative coagulopathy. A proposed pathogenetic mechanism for environmental illness.

Freshly prepared, unstained peripheral blood smears from 46 of 50 patients with chronic environmental illness showed clear microscopic evidence of advanced oxidative injury to all elements of circulating blood. As observed with high‐resolution (15,000×) phase‐contrast and darkfield microscopy, morphologic patterns of oxidative injury to blood components have been designated oxidative coagulopathy, a state of circulating blood comprising: structural abnormalities involving erythrocytes and granulocytes and zones of congealed plasma in its early stages; fibrin clots and thread formation with platelet entrapment in the intermediate stages; and microclot and microplaque formation in late stages. Moderate to advanced changes of oxidative coagulopathy were seen in only two of 15 healthy control subjects. Oxidative coagulopathy begins with oxidative activation of plasma enzymes and leads to oxidative permutations of plasma lipids, proteins, and sugars, and is not merely confined to oxidative activation of recognized coagulation pathways. It is proposed that oxidative coagulopathy represents one of the core pathogenetic mechanisms of homeostatic dysregulation seen in environmental illness and leads to oxidative injury to intracellular matrix, cell membranes, and intracellular organelles such as mitochondria. The observed cellular and plasma changes shed considerable light on many aspects of the macroecologic toxicants and their cellular targets, as well as the microecologic oxidants and their molecular targets. Oxidative coagulopathy is a powerful explanation of the production of symptom‐complexes characteristically encountered in environmental illness.
On Becoming a Physical Educator: Occupational Choice and the Anticipatory Socialization Process

This paper reviews selected recruitment resources to physical education based on Lortie's (1975) paradigm of occupational choice and the anticipatory socialization process. Based on data from physical education entry studies (Mulling, 1981; Pooley, 1970; Woodford, 1977; Templin, Note 1), examples of how selected resources both attract and facilitate entrance into the field are presented. Such resources as the interpersonal and service dimensions of teaching, a desire for continued association with sport, time compatibility, job security, eased entrance, and various socializing agents are shown to have some degree of influence on one's decision to enter physical education. Finally, various implications of the data are discussed in relation to the professional preparation process.
Daily Cycle of bHLH-PAS Proteins, Ah Receptor and Arnt, in Multiple Tissues of Female Sprague–Dawley Rats

Abstract The aryl hydrocarbon receptor (AhR) shares a common PAS domain with a number of genes that exhibit a pronounced circadian rhythm. Therefore, this study examined the daily cycle of AhR and AhR nuclear translocator (Arnt) protein expression in multiple tissues of female Sprague–Dawley rats. Rats were euthanized at 4, 7, and 11 am and 4, 7, and 11 pm after which whole tissue homogenates were made from multiple tissues. Western blot analysis showed that the daily cycle of relative AhR protein expression exhibits a similar oscillation pattern in the liver, lungs, and thymus. The daily cycle of relative Arnt protein expression exhibits a similar oscillation pattern in the liver and lungs. The apparent daily cycle of AhR and Arnt protein expression in multiple tissues was not observed within the spleen. This preliminary report is the first study to suggest that the PAS proteins, AhR and Arnt, exhibit a daily oscillation pattern within multiple target tissues which may give insight into the tissue-specific toxic and biochemical responses mediated through this dimerization pair, as well as the physiological function of these proteins.
Critical differences between two classical surgical approaches for middle cerebral artery occlusion-induced stroke in mice.

Abstract Background Stroke is the third leading cause of death and the leading cause of long-term disability in North America. On average, someone in the US has a stroke every 45 s, and worldwide, stroke claims 15 million lives each year. Therefore, reliable stroke models are vital to the production of effective new therapies for the treatment of this devastating cerebral vascular accident. New method Middle cerebral artery occlusion (MCAo) is considered to be the most clinically relevant surgical model of ischemic stroke, in which a variety of methods may be employed to block the MCA (the most common being through insertion of a monofilament). In this study, we have compared two different approaches that are currently used arbitrarily in various laboratories worldwide: one involving insertion of a monofilament via the common carotid artery (Koizumi et al.) and one via the external carotid artery (Longa et al.). Results and comparisons with existing methods We assessed various parameters, including: mortality rates, neurological scores, inflammation levels, cellular trafficking (using intravital microscopy) and infarct volumes in mice after using each of the two approaches. We found that the Longa method produced a greater, and robust, inflammatory response, versus the Koizumi method. Conclusions In conclusion, we suggest that the Longa method is superior for the study of both short and long-term outcomes of ischemic stroke. These results have considerable implications on stroke model selection for researchers.
Community-wide coronary heart disease mortality in Mexican Americans equals or exceeds that in non-Hispanic whites: the Corpus Christi heart project ☆

Abstract PURPOSE: Previous comparisons of coronary heart disease mortality between Mexican Americans and non-Hispanic whites have given paradoxic results: despite their adverse cardiovascular risk profiles, especially a greater prevalence of diabetes, Mexican Americans are reported to have lower rates of mortality from coronary heart disease. SUBJECTS AND METHODS: We performed a community-based surveillance among all residents of Nueces County, Texas, aged 25 to 74 years, from 1990 to 1994. All death certificates were obtained and coded, and deaths potentially related to coronary heart disease were selected and validated by standardized methods blinded to ethnicity. Validated in-hospital and out-of-hospital coronary heart disease mortality was compared between 785 Mexican Americans and 862 non-Hispanic white women and men. RESULTS: Validated coronary heart disease mortality in Mexican Americans exceeded that for non-Hispanic whites in the same community. Among women, definite coronary heart disease mortality was 40% greater among Mexican Americans (rate ratio [RR] 1.43, 95% confidence interval [CI]: 1.12 to 1.82), as was all coronary heart disease mortality (RR, 1.32, 95% CI: 1.08 to 1.63). Among men, Mexican Americans had greater rates of all (RR, 1.11; 95% CI: 0.96 to 1.28) and definite coronary heart disease mortality (RR, 1.16; 95% CI: 0.91 to 1.47), but the associations were not statistically significant. CONCLUSIONS: When community-wide mortality rates from coronary heart disease are properly validated, Mexican Americans have rates equal to or higher than those of non-Hispanic whites. Community-based surveillance with validation of coronary heart disease as the cause of death is necessary to avoid the errors that occur with the use of death certificates alone.
Electron multiplication in bistable storage tube targets

The operation of direct-view bistable storage tubes is generally explained in terms of secondary emission at the target. The maximum stored-writing speed is determined by the current density of the primary beam, the target capacity, and the secondary emission properties of the target. Since these quantities are known or can be measured, the maximum stored-writing speed can be estimated. In MgO = doped phosphor targets used in certain bistable storage tubes, stored-writing speeds were observed which were too fast to be explained by simple secondary emission. Storage speeds increased with MgO content and target porosity. These observations led to speculation on the possibility of charge-multiplication occurring within the target because of a field-dependent secondary-electron multiplication process. This paper presents the results of a series of experiments undertaken to detect and measure charge-multiplication in certain storage targets. The method involved pulsing the writing gun and viewing gun of a storage tube in sequence and measuring the resultant charge-transients in the target circuit. Target-gain was determined by comparing the total primary charge with the charge delivered by the flood gun in restoring the surface potential. Charge-multiplication was observed in certain targets using this technique, and maximum gain factors in the range 10 to 100 were measured in various samples. Target-gain was dependent primarily on the voltage across the storage layer and increased rapidly as this voltage was raised above the first crossover potential of the target material. The gain was relatively independent of primary-beam voltage over the range 0.5 to 3 kV.
Significance of the Dissociation of Dna2 by Flap Endonuclease 1 to Okazaki Fragment Processing in Saccharomyces Cerevisiae

Okazaki fragments are initiated by short RNA/DNA primers, which are displaced into flap intermediates for processing. Flap endonuclease 1 (FEN1) and Dna2 are responsible for flap cleavage. Replication protein A (RPA)-bound flaps inhibit cleavage by FEN1 but stimulate Dna2, requiring that Dna2 cleaves prior to FEN1. Upon cleavage, Dna2 leaves a short flap, which is then cut by FEN1 forming a nick for ligation. Both enzymes require a flap with a free 5'-end for tracking to the cleavage sites. Previously, we demonstrated that FEN1 disengages the tracking mechanism of Dna2 to remove it from the flap. To determine why the disengagement mechanism evolved, we measured FEN1 dissociation of Dna2 on short RNA and DNA flaps, which occur during flap processing. Dna2 tracked onto these flaps but could not cleave, presenting a block to FEN1 entry. However, FEN1 disengaged these nonproductively bound Dna2 molecules, proceeding on to conduct proper cleavage. These results clarify the importance of disengagement. Additional results showed that flap substrate recognition and tracking by FEN1, as occur during fragment processing, are required for effective displacement of the flap-bound Dna2. Dna2 was recently shown to dissociate flap-bound RPA, independent of cleavage. Using a nuclease-defective Dna2 mutant, we reconstituted the sequential dissociation reactions in the proposed RPA/Dna2/FEN1 pathway showing that, even without cutting, Dna2 enables FEN1 to cleave RPA-coated flaps. In summary, RPA, Dna2, and FEN1 have evolved highly coordinated binding properties enabling one protein to succeed the next for proper and efficient Okazaki flap processing.
Multi-scale Modeling of Enhanced Dissolution and Deformation of Geomaterials: A Discrete Element Approach

Geomaterials often respond to evolving environmental circumstances through generation of a series of mechanisms of mechanical deformation and chemical reactions. Such interaction of chemical and mechanical processes is believed to play a critical role in many natural geomechanical processes such as sediment compaction and rock weathering or landsliding. Attempts have also been made to take advantage of these multi-physics mechanisms for engineering applications such as microbially induced calcite precipitation (MICP) technology for soil improvement and CO2 sequestration. This paper is devoted to a numerical approach for the interaction of mechanical processes and intrinsic or externally controlled chemical processes, with a focus on the evolution of mechanical and transport properties affected by mineral dissolution, diffusion, precipitation across scales. Discrete element modelling (DEM) is employed and two applications are examined. The effect of the mineral dissolution on the mechanical response at the grain contact is incorporated into a modified linear contact model. DEM simulations are performed to examine the overall mechanical response of particle assembles subject to mineral dissolution and precipitation. The results demonstrate the important role of the kinetic rate characteristics of the dissolution process. The presented analysis is a feasibility study of the use of DEM to model coupled chemo-mechanical phenomena.
On the stability of sigma delta modulators

A framework for stability analysis of sigma-delta modulators is presented. It is argued that limit cycles for constant inputs are natural objects to investigate in this context. A number of analytical and approximate techniques to aid the stability analysis of the double loop and interpolative modulators are discussed and lead to ways of improving the design that explicitly take stability into account. >
Dirac equation around a charged, rotating black hole

The Dirac equation for an electron around a Kerr-Newman black hole is separated into decoupled ordinary differential equations.
The Strategic Value of IT-Enabled Innovation: Examining the Co- evolution of Theory and Practice

Over the past several decades, information technology (IT) has enabled management innovations such as Business Process Reengineering, Knowledge Management, Inventory Management, Total Quality Manag...
The molecular basis of carbon-starvation-induced general resistance in Escherichia coli.

At the onset of starvation Escherichia coli undergoes a temporally ordered program of starvation gene expression involving 40-80 genes which some four hours later yields cells possessing an enhanced general resistance. Two classes of genes are induced upon carbon starvation: the cst genes, requiring cyclic AMP, and the pex genes, not requiring this nucleotide for induction. The cst genes are not involved in the development of the resistant state and are concerned with escape from starvation, while the pex gene induction appears to be associated with resistance. Many of the latter are induced in response to a variety of starvation conditions. They include heat shock and oxidation resistance genes, and some utilize minor, stationary-phase-specific sigma factors for induction during starvation. The protective role of stress proteins may be due to their ability to rescue misfolded macromolecules. The starvation promoters can be potentially useful for selective expression of desired genes in metabolically sluggish populations, e.g. in high-density industrial fermentations and in situ bioremediation.
Unitary consciousness requires distributed comparators and global mappings

Gray, like other recent authors, seeks a scientific approach to consciousness, but fails to provide a biologically convincing description, partly because he implicitly bases his model on a computationalist foundation that embeds the contents of thought in irreducible symbolic representations. When patterns of neural activity instantiating conscious thought are shorn of homuncular observers, it appears most likely that these patterns and the circuitry that compares them with memories and plans should be found distributed over large regions of neocortex.
An NMR and quantum-mechanical investigation of tetrahydrofuran solvent effects on the conformational equilibria of 1,4-butanedioic acid and its salts.

Vicinal proton−proton NMR couplings have been used to compare the influences of water and tetrahydrofuran (THF) as solvents on the conformational equilibria of 1,4-butanedioic (succinic) acid and its mono- and dianionic salts. An earlier NMR investigation (Lit, E. S.; Mallon, F. K.; Tsai, H. Y.; Roberts, J. D. J. Am Chem. Soc. 1993, 115, 9563−9567) showed that, in water, the conformational preferences for the gauche conformations for butanedioic acid and its monoanion and dianion were, respectively, ∼84%, 66%, and 43%, essentially independent of the nature of the cation or concentration. We now report the corresponding gauche percentages calculated in the same way for 0.05 M solutions in THF to be 66%, 90−100%, and 46−64%. Substantial evidence was adduced for the rotational angle between the substituents in the monoanion being ∼70°. The positions of conformational equilibria of the salts in THF, particularly of the dianion, were found to be rather insensitive to concentration and temperature, but more sensitive to the amount of water present. Ab initio quantum-mechanical calculations for 1,4-butanedioate dianion indicate that, as expected for the gas phase, the trans conformation of the dianion should be heavily favored over the gauche, but, in both THF and water, the gauche conformation is calculated to predominate with rotational angles substantially less than 60°. This conclusion is, in fact, generally consistent with the experimental vicinal proton couplings, which are wholly inconsistent with the trans conformation.
Considerations for Thermal Injury Analysis for RF Ablation Devices

Background: The estimation of lesion size is an integral part of treatment planning for the clinical applications of radiofrequency ablation. However, to date, studies have not directly evaluated the impact of different computational estimation techniques for predicting lesion size. In this study, we focus on three common methods used for predicting tissue injury: (1) iso-temperature contours, (2) Cumulative equivalent minutes, (3) Arrhenius based thermal injury. Methods: We created a geometric model of a multi-tyne ablation electrode and simulated thermal and tissue injury profiles that result from three calculation methods after 15 minutes exposure to a constant RF voltage source. A hybrid finite element technique was used to calculate temperature and tissue injury. Time-temperature curves were used in the assessment of iso-temperature thresholds and the method of cumulative equivalent minutes. An Arrhenius-based formulation was used to calculate sequential and recursive thermal injury to tissues. Results: The data demonstrate that while iso-temperature and cumulative equivalent minute contours are similar in shape, these two methodologies grossly over-estimate the amount of tissue injury when compared to recursive thermal injury calculations, which have previously been shown to correlate closely with in vitro pathologic lesion volume measurement. In addition, Arrhenius calculations that do not use a recursive algorithm result in a significant underestimation of lesion volume. The data also demonstrate that lesion width and depth are inadequate means of characterizing treatment volume for multi-tine ablation devices. Conclusions: Recursive thermal injury remains the most physiologically relevant means of computationally estimating lesion size for hepatic tumor applications. Iso-thermal and cumulative equivalent minute approaches may produce significant errors in the estimation of lesion size.
TOWARD CONSTRUCTING A DIALECTICS OF HARMONIZATION: HARMONY AND CONFLICT IN CHINESE PHILOSOPHY

La metaphysique du conflit et de l'harmonie dans le confucianisme comme opposition du mal et du bien qui rend les deux themes complementaires. Le taoisme valorise l'harmonie en allant vers la suppression du conflit. S'opposant a une dialectique de la lutte et a une dialectique de la transcendance par negation dans le nirvana, la dialectique de l'harmonisation aboutit a un accord de tous les poles contraires.
A 35,000 Year Vegetation and Climate History from Potato Lake, Mogollon Rim, Arizona

A new record from Potato Lake, central Arizona, details vegetation and climate changes since the mid-Wisconsin for the southern Colorado Plateau. Recovery of a longer record, discrimination of pine pollen to species groups, and identification of macrofossil remains extend Whiteside's (1965) original study. During the mid-Wisconsin (ca. 35,000-21,000 yr B.P.) a mixed forest of Engelmann spruce (Picea engelmannii) and other conifers grew at the site, suggesting a minimum elevational vegetation depression of ca. 460 m. Summer temperatures were as much as 5°C cooler than today. During the late Wisconsin (ca. 21,000-10,400 yr B.P.), even-cooler temperatures (7°C colder than today; ca. 800 m depression) allowed Engelmann spruce alone to predominate. Warming by ca. 10,400 yr B.P. led to the establishment of the modern ponderosa pine (Pinus ponderosa) forest. Thus, the mid-Wisconsin was not warm enough to support ponderosa pine forests in regions where the species predominates today. Climatic estimates presented here are consistent with other lines of evidence suggesting a cool and/or wet mid-Wisconsin, and a cold and/or wet late-Wisconsin climate for much of the Southwest. Potato Lake was almost completely dry during the mid-Holocene, but lake levels increased to near modern conditions by ca. 3000 yr B.P.
Three Steps for Gaining Access to the General Education Curriculum for Learners with Disabilities

The author presents a three-step process for helping teachers determine how accessible their general education curriculum is for students with disabilities. Checklists, examples, and rubrics guide ...
On Performance Modeling and Prediction in Support of Scientific Workflow Optimization

The computing modules in distributed scientific workflows must be mapped to computer nodes in shared network environments for optimal workflow performance. Finding a good workflow mapping scheme critically depends on an accurate prediction of the execution time of each individual computational module in the workflow. The time prediction of a scientific computation does not have a silver bullet as it is determined collectively by several dynamic system factors including concurrent loads, memory size, CPU speed, and also by the complexity of the computational program itself. This paper investigates the problem of modeling scientific computations and predicting their execution time based on a combination of both hardware and software properties. We employ statistical learning techniques to estimate the effective computational power of a given computer node at any point of time and estimate the total number of CPU cycles needed for executing a given computational program on any input data size. We analytically derive an upper bound of the estimation error for execution time prediction given the hardware and software properties. The proposed statistical analysis-based solution to performance modeling and prediction is validated and justified by experimental results measured on the computing nodes that vary significantly in terms of the hardware specifications.
Teaching Practices and Exploratory Computer Simulations

While computing technologies are widely available in secondary schools, these technologies have had only limited impact on changing classroom practices. In part, this can be attributed to an underdeveloped understanding of the role of the teacher in engaging in classroom practices that can support student learning with technology. In this qualitative study, we analyzed the teaching practices that supported pre-college students’ learning of a conceptually rich and deep topic (the average rate of change) when using an exploratory computer simulation environment. The results illustrate the demands placed on teachers when faced with the generation of student ideas from their interactions with the simulation and three broad categories of teaching practices in response to these demands: (a) pressing students for representations, (b) harvesting student ideas, and (c) sorting out and refining student ideas. These findings contribute to evolving frameworks for understanding meaningful and productive technology use...
THE INFLUENCE OF MORDANT ON THE LIGHTFASTNESS OF YELLOW NATURAL DYES

AbstractWool specimens were premordanted with alum, chrome, copper, iron, or tin mordants and dyed with 18 yellow natural dyes. The dyed specimens were then exposed to a xenon-arc lamp for 5, 10, 20, 40, and 80 AATCC Fading Units. The color changes were evaluated instrumentally with a color difference meter and visually by trained observers. Color differences in CIE L*a*b* units, gray scale classifications, and lightfastness ratings were reported.Turmeric, fustic, and marigold dyes faded significantly more than any of the other yellow dyes. However, dyes applied with tin and alum mordants faded significantly more than dyes mordanted with chrome, copper, or iron. In fact, mordant affected lightfastness more than dye or length of exposure. This showed that mordant was more important than dye in predicting lightfastness of colored textiles. Consequently, to make the best decisions regarding display of a textile, museum personnel should have both mordant and dye identified.
FUZZY STATE AGGREGATION AND POLICY HILL CLIMBING FOR STOCHASTIC ENVIRONMENTS

Reinforcement learning is one of the more attractive machine learning technologies, due to its unsupervised learning structure and ability to continually learn even as the operating environment changes. Additionally, by applying reinforcement learning to multiple cooperative software agents (a multi-agent system) not only allows each individual agent to learn from its own experience, but also opens up the opportunity for the individual agents to learn from the other agents in the system, thus accelerating the rate of learning. This research presents the novel use of fuzzy state aggregation, as the means of function approximation, combined with the fastest policy hill climbing methods of Win or Lose Fast (WoLF) and policy-dynamics based WoLF (PD-WoLF). The combination of fast policy hill climbing and fuzzy state aggregation function approximation is tested in two stochastic environments: Tileworld and the simulated robot soccer domain, RoboCup. The Tileworld results demonstrate that a single agent using the combination of FSA and PHC learns quicker and performs better than combined fuzzy state aggregation and Q-learning reinforcement learning alone. Results from the multi-agent RoboCup domain again illustrate that the policy hill climbing algorithms perform better than Q-learning alone in a multi-agent environment. The learning is further enhanced by allowing the agents to share their experience through a weighted strategy sharing.
Quasigeostrophic turbulence with explicit surface dynamics: Application to the atmospheric energy spectrum

Abstract The horizontal wavenumber spectra of wind and temperature near the tropopause have a steep −3 slope at synoptic scales and a shallower −5/3 slope at mesoscales, with a transition between the two regimes at a wavelength of about 450 km. Here it is demonstrated that a quasigeostrophic model driven by baroclinic instability exhibits such a transition near its upper boundary (analogous to the tropopause) when surface temperature advection at that boundary is properly resolved and forced. To accurately represent surface advection at the upper and lower boundaries, the vertical structure of the model streamfunction is decomposed into four parts, representing the interior flow with the first two neutral modes, and each surface with its Green’s function solution, resulting in a system with four prognostic equations. Mean temperature gradients are applied at each surface, and a mean potential vorticity gradient consisting both of β and vertical shear is applied in the interior. The system exhibits three f...