nils-herrmann/clean_scirepeval huggingface dataset:
Toxic trace metal speciation: importance and tools for environmental and biological analysis

Total element determinations of toxic metals, both in environmental and in biological materials or in living organisms, are increasingly demanded by society. This determination of low levels of toxic metals, and also of essential and therapeutic trace elements, is normally accomplished by atomic spectrometry methods, very appropriate for this analytical task (e.g. concentrations below 10 pg.g-’ in tissues, 10 pg.1-l in biological fluids or less than 1 pg.1” in river waters, need today to be monitored). However, every chemist in his laboratory recognises that a trace element, and so a toxic metal, can exist in a given real sample, e.g. a sediment, urine, serum, etc, in a most varied number of physico-chemical forms (e.g. in the case of lead: Pbt2, Pb(OH)2, Pb(OH)i, (CH&Pb, (CH3-CH2)4Pb, etc). More recently, the scientific community has concluded that toxicity, bioavailability, bioactivity, transport in the organism, bio-geological distributionltransportation and, thus, the eventual impact of the toxic element in our body and environment, will be dictated by the particular species or form present in the sample. In this sense, total element determinations by atomic spectroscopy, as discussed before, of a toxic element as As, Hg or Sn are insufficient today, and sometimes misleading, to assess the toxicity of a food or sediment (e.g. arsenobetaine is not toxic, methylmercury is much more toxic than Hg’2 and tributyltin is a most potent biocide, while Sn(IV) is not). Therefore, additional “speciation” information to complement total toxic element determinations is being increasingly demanded, both in environmental and in clinicaVbiologica1 issues (1,2).

Field of study: Chemistry
Experimental and numerical determination of mode II fracture toughness of woven composites verified through unidirectional composite test data

Due to the increase in prevalence of fibre-reinforced polymer matrix composites (FRPMC) in aircraft structures, the need for adaption of failure prediction tools such as fatigue spectra has become more pertinent. Fracture toughness is an important measure with regard to fatigue, while adequate techniques and an ASTM standard for unidirectional FRPMC exist, there are mixed opinions when investigating woven FRPMC. This study describes a three-dimensional finite element model developed to assist in determining the mode II interlaminar fracture toughness (G IIc) of fibre-reinforced woven composites, validated by an experimental and numerical comparison of G IIc determination for unidirectional FRPMC. Experimental testing mirroring the ASTM D7905 resulted in a measure of 1176 J m−2 for the unidirectional specimen, while comparisons made with the literature achieved an average value of 1459.24 J m−2 or the woven specimen. Three numerical methods were employed due to their prominence in the literature: displacement field, virtual crack closure techniques and the J integral. Both the J integral and the displacement field three-dimensional models produced satisfactory unidirectional G IIc estimates of 1284 and 1116.8 J m−2, respectively. Displacement field had a 5% uncertainty in G IIc when compared with experimental results, while J integral had an approximately 8.5% uncertainty. Extending the analysis to the woven specimens, values of 1302.8 and 1465.3 J m−2 were obtained from J integral and displacement field methods, respectively, both within 10% of the experimental values. Hence, numerically determined unidirectional G IIc values were verified with experimental results, leading to the successful employment and extension to woven composites which displayed similar agreement.

Field of study: Materials science
Drift velocity in an amplification zone of wind waves

Drift wind flow in the amplification zone of a wind wave is investigated experimentally. It is found that the wind drift diminishes in proportion to the wave steepness on the forward slope of a wave in the region of a water surface deformed by vortices in a viscous layer of air. Vortices delaying the drift are found in the viscous layer on the back slope of a wave where the shift velocity of water diminishes.

Field of study: Physics
BeSAT: behavioral SAT-based attack on cyclic logic encryption

Cyclic logic encryption is newly proposed in the area of hardware security. It introduces feedback cycles into the circuit to defeat existing logic decryption techniques. To ensure that the circuit is acyclic under the correct key, CycSAT is developed to add the acyclic condition as a CNF formula to the SAT-based attack. However, we found that it is impossible to capture all cycles in any graph with any set of feedback signals as done in the CycSAT algorithm. In this paper, we propose a behavioral SAT-based attack called BeSAT. Be-SAT observes the behavior of the encrypted circuit on top of the structural analysis, so the stateful and oscillatory keys missed by CycSAT can still be blocked. The experimental results show that BeSAT successfully overcomes the drawback of CycSAT.

Field of study: Computer science, Mathematics
TRPM2 Silencing Causes G2/M Arrest and Apoptosis in Lung Cancer Cells via Increasing Intracellular ROS and RNS Levels and Activating the JNK Pathway.

The oxidative stress sensor transient receptor potential melastatin-2 (TRPM2) ion channel has recently gained attention in many types of cancer. The lung tissue is highly susceptible to oxidative stress-mediated injury and diseases; therefore, we aimed to determine whether TRPM2 plays an essential role in protecting lung cancer cells from oxidative damage while promoting cancer cell survival and metastasis.



We used two non-small cell lung (NSCLC) cell lines A549 and H1299 as a lung cancer model. We investigated the functional expression of TRPM2 using electrophysiology, qRT-PCR and Western blots. CFSE and flow cytometry were used to study TRPM2 role in proliferation, cell cycle and apoptosis. Gap closure chambers and Three-Tiered Chemotaxis Chamber were used to study the role of TRPM2 in metastasis. SCID mice were used to study the role of TRPM2 in lung tumor growth and metastasis.



we demonstrate that TRPM2 is functionally expressed in NSCLC cells and that its downregulation significantly inhibits cell proliferation and promotes apoptosis. These results were concomitant with an induction in DNA damage and G2/M cell cycle arrest. TRPM2 silencing inhibits also lung cancer cells invasion ability and alters EMT processes. Mechanistically, TRPM2 downregulation causes an increase in the intracellular levels of reactive oxygen (ROS) and nitrogen (RNS) species, which in turn causes DNA damage and JNK activation leading to G2/M arrest, and an ultimate cell death. Finally, TRPM2 downregulation suppresses the growth of human lung tumour xenograft in SCID mice and TRPM2 depleted tumours exhibited a significant reduction in the mRNA expression level of EMT markers compared to the control tumors.



Our data provide new insights on the functional expression of TRPM2 in lung cancer, its essential role in tumour growth and metastasis through the control of JNK signaling pathway, and that TRPM2 could be exploited for targeted lung cancer therapies.

Field of study: Biology, Chemistry
Concurrent schedules of primary and conditioned reinforcement in rats.

Rats responded on a fixed-interval schedule during which a 3-sec stimulus preceded each water reinforcement. The stimulus was then scheduled concurrently for responses on the same lever according to either a variable ratio. Although water reinforcement continued on a fixed-interval schedule, the pattern of responding became typical of a variable-interval or variable-ratio schedule. When the 3-sec stimulus was presented on a variable-interval or variable-ratio schedule, but was omitted on the fixed-interval schedule, the response rate decreased. When the stimulus occurred after the same time periods as those of the variable-interval schedule, but at least 7-sec after the last response, the rate decreased. The rate became higher when the fixed-interval schedule was discontinued and each presentation of the 3-sec stimulus was followed by water on a variable-interval schedule. When both water and the 3-sec stimulus were discontinued for a period of time, resulting in extinction of the lever response, and the 3-sec stimulus alone then presented on a variable-interval or variable-ratio schedule after lever responses, rate increased and then gradually decreased.

Field of study: Biology, Psychology
Ultra-deep imaging with amateur telescopes

Amateur small equipment has demonstrated to be competitive tools to obtain ultra-deep imaging of the outskirts of nearby massive galaxies and to survey vast areas of the sky with unprecedented depth. Over the last decade, amateur data have revealed, in many cases for the first time, an assortment of large-scale tidal structures around nearby massive galaxies and have detected hitherto unknown low surface brightness systems in the local Universe that were not detected so far by means of resolved stellar populations or HI surveys. In the Local Group, low-resolution deep images of the Magellanic Clouds with telephoto lenses have found some shell-like features, interpreted as imprints of a recent LMC-SMC interaction. In this review, I discuss these highlights and other important results obtained so far in this new type of collaboration between high-class astrophotographers and professional astronomers in the research topic of galaxy formation and evolution.

Field of study: Physics
A ß-distributed stochastic petri net model for software project time/cost management

This article proposes a new software project time and cost management model using a β-distributed stochastic petri net (BSPN), which is an integrated model of PERT and Petri nets. We adapt the β-distributed transition from program evaluation and review technique (PERT) for modeling uncertainty of time and cost of a software project. A source BSPN of a software project is constructed via the top-down modeling method or transformation method. The source BSPN can be transformed into a reduced BSPN by use of reduction rules. Structural properties of the project are analyzed from the BSPN structure. Behavioral characteristics of the project, such as time and cost, are analyzed via a chronological reachability graph (CRG) of a BSPN. The CRG is a new kind of timed reachability graph. The BSPN model is powerful enough to cope with the uncertainty and concurrency problems of large software project management.

Field of study: Computer science, Engineering
A Note on Error Correction Mechanisms and Steady-State Error

where x* is the exogenous desired value of xt and A(L) is a rational polynomial in the lag operator. Here xt is any variable which responds to disequilibria in the manner of equation (i). Part of Salmon's interest is in the steady-state error e" = X*8-x88, where x*8 follows a dynamic equilibrium path: his analysis emphasises that this error depends both on the nature of this path and on the adjustment polynomial A(L). Defining the type of (i) to be the number of unit denominator roots in A(L), he obtains the simple result that an error correction model of type s is required to guarantee a zero steady-state error when x*8 is following a polynomial of degree s I; this has recently been interpreted in terms of growth coefficients by Patterson and Ryding (I984). Because Salmon employs z-transforms his paper is not readily accessible to many economists, but we analyse the problem in the familiar terms of linear difference equations. Since Section I shows that Salmon's condition is necessary but not sufficient, this part of the note serves both to complement and to complete his study; although growth coefficients are not pursued here, it should be noted that Patterson and Ryding also overlook the stability requirement for their analysis. The extension to stochastic models in Section II is straightforward, and the results of Kloek (I984) for this case are seen to be essentially those obtained by Salmon. Our final section discusses the representation appropriate for these models.

Field of study: Economics
Optimization of adaptation plans for a service-oriented architecture with cost, reliability, availability and performance tradeoff

A service-based system may require adaptation for several reasons, such as service evolution (e.g., a new version may be available), hardware volatility (e.g., network quality changes), and varying user demands and new requirements (e.g., a new functionality or a different level of quality of service). Therefore, it is suitable to dynamically adapt a service-based system in an automated manner. However, service adaptations often do not consider software quality attributes and, if they do, they relay on a single attribute in isolation. In this paper, we present an optimization model, which aims to minimize the adaptation costs of a Service-Oriented Architecture (SOA), in correspondence with a certain change scenario (i.e., a set of new requirements) under reliability, availability and performance tradeoff. The model predicts the quality of the new SOA obtained by changing both its structure and behavior. Specifically, it suggests how to replace existing services with available instances and/or adding new services, and how to remove or introduce interaction(s) between existing services and/or new services. We show how our model works on a smartphone mobile application example, and through the sensitivity analysis we highlight its potential to drive architectural decisions.

Field of study: Computer science, Engineering
Redox Interactions of Cr(VI) and Substituted Phenols: Kinetic Investigation.

The kinetics of the reduction of Cr(V1) to Cr(II1) by substituted phenols in aqueous solution were studied over environmentally relevant ranges of reactant concentrations, pH, temperature, and ionic strength. At a fixed pH, the reaction was first order with respect to both the concentration of phenol reductant and the total concentration of monomeric Cr(V1). Reaction rates increased as much as 4 orders of magnitude from pH 5 to pH 1. The apparent reaction order with respect to [H+l varied between 0.2 and 2 over this same pH range, but also depended on the structure of the phenol. Comparison of the reactivities of 14 substituted phenols revealed a strong substituent effect. A t pH 2, rates for the 14 phenols spanned more than 5 orders of magnitude with reactivity generally increasing with the electron-donating character of the substituent (methoxy > methyl > chloro, aldehyde > nitro). Substituent effects are described by a linear correlation of the second-order rate constants ( ~ A ~ o H ) with the phenol half-wave potential (Elp). Representative reaction half-lives fall within the time scales of major environmental transport processes and suggest that the kinetics of these interactions are of significant concern in assessing sites contaminated with chromium and phenolic compounds.

Field of study: Environmental science
5-thiazolyl derivatives of 4-aryl-3,4-dihydropyrimidin-2(1H)-ones

As shown by calculations by means of the PASS software , the 5-(1,3-thiazol-4-yl) derivatives of 4-aryl-3,4-dihydropyrimidin-(1H)-2-ones are promising subjects in the search for physiologically active substances. Moreover, there are few publications on the synthesis of 4-aryl-3,4-dihydropyrimidin-(1H)-2-ones containing a heterocyclic fragment at position 5 [2-4], and their synthesis will make it possible to develop substantially the theories about such systems. The most obvious way of constructing the 1,3-thiazole ring is the Hantsch reaction, the starting materials for which must be the ω-bromoacetyl derivatives of compounds produced by the Biginelli reaction. It is known that the related 4-aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2(1H)-ones, also produced by the Biginelli reaction, are brominated at the methyl group with the formation of 6-bromomethyl and 6,6-dibromomethyl derivatives [5-7]. We studied the bromination of the 5-acetyl derivatives of 4-aryl-3,4dihydropyrimidin-2(1H)-ones 1 and 2 in order to determine how the presence (or absence) of the 6-methyl group in these molecules would affect the course of bromination. As found, the 6-methyl derivative 1 does not react with bromine in acetic acid at room temperature (the initial compound is recovered completely on dilution of the reaction mixture with water), while the low solubility of the compound does not permit the reaction in chloroform or alcohol. At the same time, the bromination of compound 1 in acetic acid with heat leads to resinification of the mixture. Earlier [8, 9] we showed that by inserting a 1-alkyl substituent it is possible to eliminate the possibility of amide–imidol tautomerism in 5-acetyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones, affecting the processes involving removal of the acetyl group, and to increase their solubility significantly, and this should make it possible to realize bromination under mild conditions. This was confirmed during the bromination of the 1,6-dimethyl derivative 2; nevertheless, a complex mixture is formed both in chloroform and in acetic acid due, probably, to crossed bromination of both the acetyl group and the 6-methyl group. We assumed that the absence of a methyl group at position 6 of the heterocycle would make it possible to minimize the contribution from the bromination paths. Compounds 3a,b corresponded fully to such a model. Our assumptions were fully confirmed; the reaction of compounds 3a,b with bromine take place at a sufficiently high rate in chloroform at room temperature. Although according to H NMR spectroscopy the bromination products represent mixtures of substances the main products among them are the ω-bromoacetyl derivatives in which we are interested, since the direct use of these mixtures in reaction with thioamides made it possible to obtain moderate yields of the corresponding thiazoles 4a-d.

Field of study: Chemistry
Analysis of the Causes of Crime and Prevention and Control of Rural Left Behind Juvenile Delinquency

Parents go out for a long time, leading to the left behind children in the management of the vacuum. Due to the abnormal development of school education, the serious lack of family education, lack of legal education in rural areas, as well as adverse social environment and other factors, the impact of the interaction, leads to the road to crime. Taking comprehensive measures to control, the active cooperation of all kinds of social forces is an effective way to prevent and control the crime of staying at home.

Field of study: Engineering
[Cognitive disorders in adolescents with multiple sclerosis: problem and methods].

A possible approach to evaluation of mild cognitive deficits in patients with multiple sclerosis (MS) is provided in the article. The results of the approbation of authors' experimental technique for studying cross-modal interactions that was carried out in healthy adolescents and MS patients are presented. Perspectives of its using in further research and some preliminary data on deficits in cross-modal syntheses in adolescents with MS are discussed. The role of impairment of interactions between different cognitive functions in the development of cognitive deficit is emphasized.

Field of study: Medicine, Psychology
NEW PRESSURE SWING ADSORPTION PROCESS WITH COLUMNS UNCOUPLED

A pilot set-up was built to test a novel four-bed pressure swing adsorption (PSA) process with a hydrogen-separation operation.The new PSA process features intermediate surge tanks, through which depressurization and re-pressurization of columns are accomplished. As consequence, the coupling between columns via pressure-equalization is disconnected, and the possibility of operating the process at lower pressure is provided. A new cycle sequence was suggested for the new PSA process. Operations of separating hydrogen from a mixture of H 2/N 2/CH 4 of molar ratio 60/10/30, which simulated the dry gas of refineries, were performed on such process at pressures lower than 1.0 MPa. Process performance was studied with columns packed consecutively with adsorbents composed of ordinary activated carbon (OAC) with ZMS-5A, and that of superactivated carbon(SAC) with ZMS-5A for the pressure range 0.4—1.0 MPa. It was proven that a relatively high recovery and as high as 99.99% of purity of the product could be realized at low pressures with the new PSA technology.

Field of study: Chemistry, Environmental science
The Stochastic Rayleigh diffusion model: Statistical inference and computational aspects. Applications to modelling of real cases

In this paper, we consider a Stochastic System modelling by the Stochastic Rayleigh Diffusion Process and we discuss theoretical aspects of the latter and establish a statistical methodology to adjust it to real cases, particulary, in the field of biometry and related areas. The Rayleigh process, according to the definition of [C. Giorno, A. Nobile, L. Ricciardi, L. Sacerdote, Some remarks on the Rayleigh process, Journal of Applied Probability 23 (1986) 398–408], is examined from the perspective of the corresponding nonlinear stochastic differential equation, and from its associated probability density function we obtain the corresponding mean functions (trend function and conditional trend function), which depend of Kummer functions. The drift parameters are estimated by maximum likelihood on the basis of continuous sampling of the process and they are calculated by computational methods. We propose numerical approximations for the diffusion coefficient, from an extension of the [M. Chesney, J. Elliot, Estimating the instantaneous volatility and covariance of risky assets, Applied Stochastic Models and Data Analysis 11 (1995) 51–58] procedure to the case of nonlinear stochastic differential equations and we establish also computational procedures and simulation algorithm, that are applied to obtened simulated paths of the fitted process. The proposed methodology is applied to two studies carried out in Andalusia (Spain) on females and males life expectancy at birth, between 1944 and 2001.

Field of study: Mathematics
Teachers’ Instructional Practices for Promoting Primary One Learners’ Mathematics Competence: A Comparative Study of Busiro and Luuka, Uganda

Mathematics is a globally compulsory school subject and plays a fundamental role in an individual’s daily life activities. Elementary school teachers’ instructional practices are key in fostering among learners the foundational competences in basic number operations. This study explored the instructional practices Primary One teachers in Busiro North and Luuka North Counties can adopt from each other in order to enhance their learners’ mathematics competence. A qualitative approach with an observational multiple case study design was employed to obtain data from 74 purposively selected teachers. Data was collected through non-participant observation. Each teacher was observed teaching mathematics to Primary One learners and interviewed after the lesson. Data obtained was analysed descriptively. Findings indicate that teachers use songs, rhymes and games involving mathematical concepts, in both English language and the local languages   to help learners attain competence. Teachers have also embraced use of locally available materials like woven plastic propylene bags (buveera) and banana fibres to make and decorate charts in the classrooms’ mathematics learning areas. Attention grabbers like “Good children, Good teacher”; “We, Work”; are common verbal interactions between teacher and learners when the class seems to lose concentration. Teachers recognise learners’ efforts when they correctly answer oral, written or practical tasks by asking the class to give a classmate “flowers” or “the pa-pa-pa clap”.Unique contribution to theory, practice and policy: For teachers to help learners’ master mathematical concepts and augment their competence, they should build on learners’ experience and prior knowledge, give learners opportunities to explain their mathematical ideas and use the think – pair – share strategy during problem solving.

Field of study: Education