nils-herrmann/clean_scirepeval huggingface dataset:
Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema.

This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in São Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment.

Field of study: Environmental science
A New GWMA Control Chart for Monitoring Process Mean and Variability

In this article, we extend a single exponentially weighted moving average semicircle (EWMA-SC) chart to a single generally weighted moving average (GWMA) chart. This new control chart can effectively combine the features of the SC chart with GWMA techniques, and can easily indicate the source and direction of a change. We perform simulations to evaluate the average run length, standard deviation of the run length, and diagnostic abilities of the GWMA-SC and EWMA-SC charts. An extensive comparison shows that the GWMA-SC control chart is more sensitive than the EWMA-SC chart for detecting small shifts in the process mean and/or variability.

Field of study: Mathematics
Microscopic origin of internal stresses in jammed soft particle suspensions.

The long time persistence of mechanical stresses is a generic property of glassy materials. Here we identify the microscopic mechanisms that control internal stresses in highly concentrated suspensions of soft particles brought to rest from steady flow. The persistence of the asymmetric angular distortions which characterize the pair distribution function during flow is at the origin of the internal stresses. Their long time evolution is driven by in-cage rearrangements of the elastic contacts between particles. The trapped macroscopic stress is related to the solvent viscosity, particle elasticity and volume fraction through a universal scaling derived from simulations and experiments.

Field of study: Physics
Enhanced Photovoltaic Properties of Bulk Heterojunction Organic Photovoltaic Devices by an Addition of a Low Band Gap Conjugated Polymer

In this study, we fabricated organic photovoltaics (OPVs) by introducing the polymer additive HTh6BT into the photoactive layer of a poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) system. The HTh6BT had a relatively low band gap energy of 1.65 eV and a molecular and crystalline structure similar to that of P3HT. In the photoactive layer, the HTh6BT and P3HT can both act as donors. In such parallel-type bulk heterojunctions, each donor can form excitons and generate charges while being separated from the donor/acceptor interface. Changes in the photovoltaic property of the OPV device by the addition of HTh6BT were evaluated, and the optical characteristics of the photoactive layer, as well as the surface morphology, polymer ordering, and crystallinity of the P3HT:PCBM film were analyzed. Compared to a device without HTh6BT, all short-circuit current densities, open-circuit voltages, and fill factors were enhanced, leading to the enhancement of the power conversion efficiency by 36%.

Field of study: Materials science
Determination of Ultratrace Polychlorinated Dibenzo-p-dioxins and Dibenzofurans by Gas Chromatography-Triple Quadrupole Mass Spectrometry

In this study a gas chromatography-tandem mass spectrometry (GC/MS/MS) method with a triple quadrupole mass spectrometer was developed for ultratrace analysis of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The GC and MS/MS parameters were optimized to improve the separation and resolution of the target compounds. In multiple reaction monitoring mode, two pairs of precursor ions and product ions were selected for each target compound for qualitative and quantitative analysis. The average relative response factors were calculated from five-point calibration (0.5-2000 μg L−1) curves for the 17 PCDD/F congeners. The relative standard deviations of all the congeners were <11%. The lower limit of detection ranged from 0.05 to 0.34 μg L−1. The method was applied to analysis of certified reference materials, including one solution sample and four sediment samples. The sediment samples were extracted by accelerated solvent extraction, and then purified using a Power-Prep(tm) automatic cleanup system. The precision of the PCDD/Fs quantitation in the solution sample was determined, and the relative standard deviations were <4%. The results for the solution and sediment samples agreed with their certified values. Consequently, this GC/MS/MS method can be proposed as an alternative to the relatively expensive high-resolution MS method for monitoring PCDD/Fs.

Field of study: Chemistry
Tetrahedral and orbital pairing: a fully gapped pairing scenario for the iron-based superconductors.

Motivated by the fully gapped superconductivity in iron-based superconductors with uncompensated electron pockets, we propose a spin singlet, but orbital triplet analogue of the superfluid phase of ^{3}He-B. We show that orbital triplets with a nominal d-wave symmetry at the iron sites can transform as s-wave pairs under rotations about the selenium sites. Linear combinations of such d(xy) and d(x2-y(2)) triplets form a fully gapped, topological superconductor. Raman-active excitations are predicted to develop below the superconducting transition temperature.

Field of study: Physics
Photoproduction of η -mesons on the deuteron above S11(1535) in the presence of a narrow P11(1670) -resonance

Incoherent photoproduction of η -mesons on the deuteron is considered. The main attention is paid to the region above the S11(1535) -resonance where a rather narrow resonance-like structure in the total cross-section extracted for γn → ηn has been reported. The corresponding experimental results are analyzed from the phenomenological standpoint within the model containing a baryon P11 with a mass of about 1670MeV and a width less than 30MeV. This resonance was suggested in some recent works as a nonstrange member of the pentaquark antidecuplet with JP = 1/2+ . The calculation is also performed for the polarized and unpolarized angular distributions of η -mesons. In addition, we present our predictions for the cross-sections of the neutral kaons and double pion photoproduction, where the same narrow P11(1670) -resonance is assumed to contribute through the decay into K0Λ and πΔ configuration.

Field of study: Physics
Abraham Madroñal .Humanismo y filología en Siglo de Oro: En torno a la obra de Bartolomé Jiménez Patón. Biblioteca Áurea Hispánica 60. Ed. José Antonio Pascual. Madrid: Iberoamericana Vervuert, 2009. 360 pp. append. bibl. €36. ISBN: 978–84–8489–452–0.


Field of study: History
Avoiding tax avoidance: A (repeated) game-theoretic approach

We propose an optimal auditing scheme for the tax authorities who face a given tax and penalty functions and a given budget constraint. Under our proposed strategy individuals can be classified into one of three groups. Each group is characterized by two parameters: (i) the probability of being audited in that group, and (ii) into which group will an individual move if: (ii.a) he reported truthfully, (ii.b) he cheated. It is then shown that there is a choice of these parameters so that in equilibrium (i.e., when every individual maximizes his payoff given the auditing strategy), the percentage of individuals that cheat is arbitrarily small.

Field of study: Economics
Improvement of Mathematic Connection and Communication Ability at Danau Paris State 1 High School Through Contextual Learning

This study aims to: 1) To find out whether the increase in mathematical connection abilities of students who get contextual learning is higher than students who get ordinary learning. 2) To find out whether the increase in mathematical communication skills of students who get contextual learning is higher than students who get ordinary learning. 3) To see whether there is an interaction between the learning approach used with the students 'initial abilities to the students' mathematical connection abilities. 4) To see whether there is an interaction between the learning approach used with students 'initial abilities to students' mathematical communication skills. The subjects in this study were students of class XII IPA-1 as an experimental class and students of class XII IPA-2 as a control class at SMA Negeri 1 Danau Paris. The results showed that: 1) Increased mathematical connection ability of students who received contextual learning was higher than students who obtained ordinary learning. 2) Improvement of mathematical communication skills of students who get contextual learning is higher than students who get ordinary learning. 3) There is no interaction between the learning approach and initial mathematical ability to improve students' mathematical connection abilities. 4) There is no interaction between learning approach and initial mathematical ability to improve students' mathematical communication skills.  mathematical connection skills, mathematical communication skills, contextual learning DOI: 10.7176/JEP/11-21-05 Publication date: July 31 st 2020

Field of study: Education
Role of phosphatidylinositol 3 kinase (PI3K) in the intracellular signaling transduction pathways mediated by TCR and CD28 of γδT cell

To explore the role of phosphatidylinositol 3 kinase (PI3K) in the intracellular signaling transduction pathways of human peripheral blood γδT cells activated by CD28 with Mycobacterium tuberculosis (M.tb) low molecular peptide antigen.  Flow cytometry was used to detect the expressions of CD69 molecule on activated γδT cells and proliferation rates of γδT cells stimulated by anti-CD28 monoclonal antibody and M.tb antigen. Meanwhile, the PI3K inhibitor LY294002 was added to block the activity of PI3K to find the effect on expressions of CD69 molecule and γδT cells proliferation response.  The expression of CD69 molecule on γδT cells and proliferation response of γδT cells were blocked by addition of LY294002.  The intracellular signaling pathways delivered by CD28 and M.tb antigen in γδT cells was transducted by PI3K. [

Field of study: Biology
Measurement of the metabolism of cytochrome P-450 in cultured hepatocytes by a quantitative and specific immunochemical method.

We have defined conditions that permit quantitative and specific measurement of the metabolism of the major phenobarbital-inducible form of cytochrome P-450 protein in primary non-proliferating monolayer cultures of adult rat hepatocytes. Isolated antibodies specifically directed against phenobarbital cytochrome P-450 are used to immunoprecipitate the cytochrome from lysates of cultured hepatocytes pulse-labelled with [(3)H]leucine. Phenobarbital cytochrome P-450 protein is then isolated from the immunoprecipitate by electrophoresis on polyacrylamide gradient slab gels. Specificity of the assay for phenobarbital cytochrome P-450 was established by competition experiments involving other forms of purified cytochrome P-450 as well as by testing antibodies directed against these other forms of the cytochrome. Using purified phenobarbital cytochrome P-450, radiolabelled in both its haem and apoprotein portions, as an internal standard, we demonstrated that, with this immunoassay, recovery of cytochrome P-450 from microsomal samples is nearly complete. Basal rates of synthesis of phenobarbital cytochrome P-450 representing as little as 0.02-0.05% of total cellular protein synthesis were reliably and reproducibly detected in hepatocyte culture maintained in serum-free medium for 72h. Moreover, inclusion of phenobarbital in the culture medium for 96h stimulated not only synthesis de novo of phenobarbital cytochrome P-450 protein, but also accumulation of spectrally and catalytically active cytochrome P-450. Advantages of this immunoassay are that metabolism (synthesis or degradation) of the haem or protein of this important form of the cytochrome can be measured conveniently in the small samples available from cultured cells without the necessity of preparing subcellular fractions.

Field of study: Biology, Computer science
Developing and Validating a Cultural User Satisfaction Instrument in Developing Countries

The competition among international cell phone providers necessitates the measurement of the cell phone technology success in developing countries in which African cultural heritage plays an important role. Efforts have been made to validate the end user computing satisfaction (EUCS) instrument of Doll and Torkzadeh as well as Hofstede’s Value Survey Module 1994 (VSM-94) instrument in cross-cultural settings. However, the culture measurement items derived from VSM-94 could not be applicable without taking into account cultural dimensions that have been found to be appropriate to developing countries which share African culture. Data were collected from 220 cell phone users from Haiti to validate EUCS and to expand its content with items from an instrument newly developed for measuring fatalism, conformism, snobbism, time management, and information sharing. The Churchill instrument development approach was adapted to develop and validate the instrument. Practical and theoretical implications are offered.

Field of study: Computer science
Asymmetric kinks: stabilization by entropic forces.

Asymmetric kinks bridging two adjacent potential valleys of equal depth but different curvature are unstable against phonon modes. When coupled to a heat bath, a kink-bearing string tends to cross over into the shallower valley; kinks are thus predicted to drift in the appropriate direction with velocity proportional to the temperature, in close agreement with numerical simulation. When contrasted by a mechanical bias, these entropic forces give rise to a rich phenomenology that includes configurational phase transitions, double-kink dissociation, and noise-directed signal transmission.

Field of study: Physics
SYNTHESIS OF 7-METHYL-6-(NITROIMIDAZOLYL)THIOPURINES

We have studied the reactions of 7-methyl-6-thiopurine with 5(4)-halo-4(5)-nitroimidazoles and 6-chloro-7-methylpurine with sodium and ammonium salts of 5-mercapto-4-nitroimidazoles. We have obtained a series of 7-methyl-6-(nitroimidazolyl)thiopurines not previously described in the literature.  P. M. Kochergin, E. V. Aleksandrova, V. S. Korsunskii, and V. S. Shlikhunova. English Translation in Chemistry of Heterocyclic Compounds , 2000, 36 (2), pp 178-181

Field of study: Chemistry
Substrate preference, uptake kinetics and bioenergetics in a facultatively autotrophic, thermoacidophilic crenarchaeote.

Facultative autotrophs are abundant components of communities inhabiting geothermal springs. However, the influence of uptake kinetics and energetics on preference for substrates is not well understood in this group of organisms. Here, we report the isolation of a facultatively autotrophic crenarchaeote, strain CP80, from Cinder Pool (CP, 88.7°C, pH 4.0), Yellowstone National Park. The 16S rRNA gene sequence from CP80 is 98.8% identical to that from Thermoproteus uzonensis and is identical to the most abundant sequence identified in CP sediments. Strain CP80 reduces elemental sulfur (S8°) and demonstrates hydrogen (H2)-dependent autotrophic growth. H2-dependent autotrophic activity is suppressed by amendment with formate at a concentration in the range of 20-40 μM, similar to the affinity constant determined for formate utilization. Synthesis of a cell during growth with low concentrations of formate required 0.5 μJ compared to 2.5 μJ during autotrophic growth with H2 These results, coupled to data indicating greater C assimilation efficiency when grown with formate as compared to carbon dioxide, are consistent with preferential use of formate for energetic reasons. Collectively, these results provide new insights into the kinetic and energetic factors that influence the physiology and ecology of facultative autotrophs in high-temperature acidic environments.

Field of study: Biology, Environmental science
Food for thought: Mathematical approaches for the conversion of high-resolution sclerochronological oxygen isotope records into sub-annually resolved time series

Oxygen isotope (δ 18 O) records of incrementally banded marine calcifiers provide high-resolution information about modern and past environmental conditions. However, given their biological origin, these records are often distorted by ontogenetic and seasonal growth pattern. To evaluate their reliability, many studies correlate skeletal δ 18 O records with instrumentally measured time series of environmental conditions using a variety of methods to recalculate their temporal framework. Lacking consistency and a limited traceability of many temporal alignment methods underline the need for standardized and flexible method for the temporal alignment of sclerochronological records. Here, two methods for the temporal alignment of sclerochronological data and their application on measured oxygen isotope signatures of a fish otolith and a marine bivalve shell are presented and compared. The first method is a flexible approach using a linear interpolation between carefully selected temporal reference points for recalculating ontogenetic growth effects with an optional extension accounting for seasonal growth oscillations. The second approach uses the seasonally-oscillating Von Bertalanffy growth function parameterized based on the oxygen isotope record to reconstruct the underlying growth model and reconstruct thereby its temporal framework. Using these methods, we re-align δ 18 O-based water temperature records of a Carlarius heudelotii otolith and a Venus crebrisulca shell with measured sea surface temperature time series and compare the resulting correlation as well as the different underlying growth models. Our results show that both methods represent useful tools for the temporal alignment of sclerochronological records. However, underlying growth models strongly differ depending on the temporal alignment method and the parameters used for the reconstruction of the temporal framework. This underlines the importance of a careful selection of a particular alignment method depending on the complexity of distortion due to seasonal and ontogenetic growth trajectories. Moreover, we show that both organisms represent reliable paleoenvironmental archives providing sub-seasonally resolved water temperature records.

Field of study: Environmental science, Geography
Arbitrary dispersion control of ultrashort optical pulseswith acoustic waves

Acousto-optic programmable filters (AOPDF) can compensate in real time for group-delay dispersion. This feature can be used in femtosecond chirped-pulse amplification to compensate dispersion adaptively. An analytical expression relating the group delay at the output of the AOPDF to the input acoustic signal was obtained with coupled-wave theory in the case of collinear bulk acousto-optic interactions. Numerical simulations in the LiNbO3 crystal are shown to support the principle of arbitrary group-delay control with an AOPDF.

Field of study: Physics
Structure-enthalpy relationships in polycyclic cata-condensed aromatic hydrocarbons

A large fraction (30 of 62) of the cata-condensed polycyclic benzenoid aromatic hydrocarbons with one to six rings have nonplanar pi carbon atom frameworks, with the minimum angle of nonplanarity approximately 30°. In addition to 17 pairs of enantiomers, four of the nonplanar cata-condensed benzenoids with six rings are redicted to be capable of existing as pairs of twisted diastereoisomers. Many of t l ! e nonplanar benzenoids are thermodynamically more stable than isomeric planar com ounds. The MMX molecular mechanics force field provides reasonable estimates o!AHP(g) and geometric structures for cata-condensed benzenoids, in good agreement with the limited experimental data. AM1 calculations are not useful to determine the AHt(g) of these compounds. A group additivity method that incorporates C-C and C-H bond terms, a resonance energy term and steric parameters can be used to accurate1 model the MMX and the experimental AHt(g) data. Both MMX and the grou abbitivity/resonance energy procedure can also be used for predictive purposes an B to estimate resonance energies.

Field of study: Chemistry
Thin-Layer Dielectric and Left-Handed Metamaterial Stacked Compact Triband Antenna for 2 GHz to 4 GHz Wireless Networks

As technology progresses, new approaches for the development of antenna systems must be developed. This study reveals a concept for a left-handed metamaterial-inspired compact triband antenna for use in wireless fidelity (WiFi), wireless local area networks (WLANs), and World Interoperability for Microwave Access (WiMAX) applications. The Microwave Studio computer technology simulation package was used to design and perform a numerical investigation on the metamaterial-inspired antenna on a thin layer of FR-4 dielectric material. The overall size of the antenna is 25 mm × 18 mm, and it is compatible with existing wireless devices. Results were measured in the frequency bands for wireless fidelity (2.41 GHz to 2.48 GHz), wireless local area networks (2.40 GHz to 2.49 GHz and 3.65 GHz to 3.69 GHz), and world interoperability for microwave access (3.30 GHz to 3.80 GHz). The measured average gain was 1.87 dBi, whereas the simulated gain was 1.93 dBi, associated with omnidirectional radiation patterns. The timing performance was analyzed, revealing fidelity factors for the face to face, side by side X, and side by side Y orientation of 0.76, 0.84, and 0.81, respectively. Finally, the operation bandwidth, antenna gain, omnidirectional radiation pattern, and fidelity factors of the timing performance reveal that the designed miniatured metamaterial antenna can be used in WiFi, WLAN, and WiMAX applications.

Field of study: Materials science
The Eighteenth-Century Town: A Reader in English Urban History 1688-1820

Urban growth and agricultural change - England and the Continent in the early modern period, E.A.Wrigley country, county, and town - patterns of regional evolution in England, A.M.Everitt urban improvement and the English economy in the 17th and 18th centuries, E.L.Jones and M.E.Falkus the English urban renaissance - the development of provincial urban culture 1680-1760, P.Borsay the London mob in the early 18th century, R.B.Shoemaker Bath - ideology and utopia 1700-1760, R.S.Neale science, provincial culture, and public opinion in enlightenment England, R.Porter money, land, and lineage - the big bourgeoisie of Hanoverian London, N.Rogers Birmingham and the West Midlands 1760-1793 - politics and regional identity in the English provinces in the later 18th century, J.Money social class and social geography - the middle classes in London at the end of the 18th century, L.D.Schwartz voluntary societies and British urban elites 1780-1850 - an analysis.

Field of study: Economics, History