nils-herrmann/clean_scirepeval huggingface dataset:
Crosslinked Carboxymethyl Starch Based Solid Phase Extraction Combined with Direct Slurry Sampling Graphite Furnace Atomic Absorption Spectrometry for Determination of Trace Cr(III) and Cr(VI)in Water

A new method of solid phase extraction(SPE),using crosslinked carboxymethyl starch(CCMS) as adsorbent,combined with direct slurry sampling graphite furnace atomic absorption spectrometry(ss-GFAAS) has been developed for the speciation of trace Cr(Ⅲ) and Cr(Ⅵ) in environmental water samples.Various influencing factors on the separation and preconcentration of Cr(Ⅲ) and Cr(Ⅵ),such as the acidity of the aqueous solution,sample volume,adsorption time and effects of other ions,have been investigated systematically.Cr(Ⅲ) could be selectively retained by CCMS at pH 6.0 within 15 min,then the retained Cr(Ⅵ) on the CCMS was separated and the slurry of the precipitate prepared in 0.1% agar suspension was directly injected into the graphite furnace for the determination of Cr(Ⅲ).Total chromium was determined after the reduction of Cr(Ⅲ) to Cr(Ⅵ) by 1 mL 1% hydroxylamine hydrochloride,and Cr(Ⅲ) concentration was calculated by subtracting Cr(Ⅲ) from total chromium.The detection limit for Cr(Ⅲ) was 0.044 μg/L with an enrichment factor of 50,and the relative standard deviation(RSD) was 10.4%(cCr(Ⅲ) =1.0 μg/L,n=11).The proposed method has been applied to the speciation of chromium in water samples with satisfactory results.To validate the method,the proposed method was also applied to the determination of Cr(Ⅲ) and Cr(Ⅵ) in environmental water reference materials and the results obtained were in good agreement with the certified value.

Field of study: Chemistry
Venture Capitalist Financing: Contemporary Foundations for Minsky’s "Wall Street" Perspective

Hyman Minsky's (1975, 1982) analysis of the predisposition of capitalistic economies like the United States to periods of hyperactivity and fragility in their financial markets is relatively straightforward. The point of departure is to note that while mainstream theory attributes macroeconomic fluctuations to exogenous disturbances that impact on decentralized markets, for Minsky instability is attributable to endogenous events of capitalist finance. Minsky's thinking drew heavily on John Maynard Keynes's probability theory (1973), G. L. S. Shackle's uncertainty (1955, 1972), and the logic of Irving Fisher's (1933) debt deflation hypothesis, in which excessive private debt and falling price levels were viewed as key factors in precipitating financial crises as the aftermath of great opportunities for business  Fisher was writing against the background of the energy revolution initiated by the internal combustion engine, which generated high profit opportunities in the early 1900s, encouraging confidence about new debt to finance capital acquisition in the transportation industries. Minsky established the principle that real debt levels do not become a problem for businesses unless the present value of a firm's cash flow becomes insufficient to meet debt obligations, as is the case if interest rates rise. "Financial fragility" arises from a need to acquire cash by selling capital assets when their value has fallen below their purchase prices, and/or below the costs of acquiring similar investments.

Field of study: Economics
Extinction in two species nonautonomous nonlinear competitive system

A two species nonautonomous nonlinear competitive system is studied in this paper. It is shown that if the coefficients are continuous, bounded above and below by positive constants and satisfy certain inequalities, then one of the components will be driven to extinction while the other one will stabilize at the certain positive solution of a nonlinear single species model. Our result not only generalizing but also improving the result of Li and Chen (2006).

Field of study: Mathematics
Evaluation of proinflammatory and immunosuppressive cytokines in blood and bone marrow of healthy hematopoietic stem cell donors☆

Cytokine composition of bone marrow microenvironment in comparison to blood is poorly explored. The goal of this study was to investigate the levels of cytokines present in peripheral blood and bone marrow of healthy hematopoietic stem cells donors. The data obtained on this subject with addition to cytometric analysis can provide new insight into the hematopoietic stem cells microenvironment. Methodology Study consisted of cytokine concentration analysis performed by ELISA tests of peripheral blood of healthy peripheral blood stem cells donors and bone marrow of healthy bone marrow donors. Additionally we have tested the expression of CD47 and CD274 proteins on the surface of hematopoietic stem cells by the flow cytometry analysis.  The results has shown different composition of analyzed cytokines (IL‐1 &bgr;, IL‐2, IL‐4, IL‐6, IL‐10, IL‐17A, TGF‐&bgr;1, IFN‐&ggr; and TNF‐&agr;) present in bone marrow and blood of stem cells donors. The hematopoietic stem cells in peripheral blood are subjected to higher levels of proinflammatory cytokines whilst the lower level of those cytokines in bone marrow with a very high level of TGF‐&bgr;1 which possibly creates a more immunosuppressive environment. The IL‐10 level was significantly higher in peripheral blood of PBSC donors after the administration of mobilizing factor (G‐CSF). The percentage of CD47+HSCs was significantly higher in bone marrow compared to peripheral blood of mobilized donors. HighlightsThe first study comparing cytokine concentration, expression of CD47 and CD274 immunosuppressive proteins on HSCs in bone marrow and blood of hematopoietic stem cells donors.Concentration of proinflammatory cytokines is higher in blood than in bone marrow.TGF&bgr; is present at very high concentrations in bone marrow.High level of IL‐10 was detected in peripheral blood of G‐CSF stimulated donors.CD47 protein expressions is higher in bone marrow than in peripheral blood.

Field of study: Medicine
Über die Sublimationswärme des Kohlenstoffs

ZusammenfassungEs ist gezeigt worden, daß die „Temperaturkurven“ des positiven Kraters des unter Überdruck brennenden Kohlelichtbogens bei Anwendung von Reinkohlen als Dampfdruckkurven des Kohlenstoffs aufgefaßt werden können, wie dies Fajans zunächst nur für Unterdruck nachweisen konnte. Die Fajansschen Berechnungen der Sublimationswärme der Kohle, die infolge Benutzung der in der Lummerschen Broschüre angegebenen ungenauen Temperaturwerte fehlerhaft scin müssen, werden auf Grund richtiger Temperaturwerte korrigiert. Für die Sublimationswärme des Kohlenstoffs ergibt sich aus Überdruck- und Unterdruckmessungen im Intervall von 0,3 bis 8 Atm., entsprechend einem Temperaturintervall von etwa 4000 bis 47000 abs. der Wert 163,5 kcal, woraus für die Sublimationswärme des Diamanten bei Zimmertemperatur der Wert 168 kcal folgt, in bemerkenswerter Annäherung an den Wert 142 kcal, der sich aus der integrierten Dampfdruckformel bei Einsetzen des theoretischen Wertes für die chemische Konstante einatomiger Gase ergibt. Diese Übereinstimmung ist hauptsächlich die Folge der korrigierten Temperaturwerte.

Field of study: Physics
A large empirical assessment of the role of data balancing in machine-learning-based code smell detection

Code smells can compromise software quality in the long term by inducing technical debt. For this reason, many approaches aimed at identifying these design flaws have been proposed in the last decade. Most of them are based on heuristics in which a set of metrics is used to detect smelly code components. However, these techniques suffer from subjective interpretations, a low agreement between detectors, and threshold dependability. To overcome these limitations, previous work applied Machine-Learning that can learn from previous datasets without needing any threshold definition. However, more recent work has shown that Machine-Learning is not always suitable for code smell detection due to the highly imbalanced nature of the problem. In this study, we investigate five approaches to mitigate data imbalance issues to understand their impact on Machine Learning-based approaches for code smell detection in Object-Oriented systems and those implementing the Model-View-Controller pattern. Our findings show that avoiding balancing does not dramatically impact accuracy. Existing data balancing techniques are inadequate for code smell detection leading to poor accuracy for Machine-Learning-based approaches. Therefore, new metrics to exploit different software characteristics and new techniques to effectively combine them are needed.

Field of study: Computer science, Engineering
Treatment and Monitoring of Uterine Apoplexy Induced by Placental Abruption

To explore the principle of treatment and monitoring of uterine apoplexy induced by placental abruption. 28 cases of uterine apoplexy with placental abruption in my hospital in the recent 5 years were analyzed retrospectively. Explored the treatment principle and the corresponding measures relating clinic. Among 28 cases of placental abruption with uterine apoplexy which had cesarean section to make the pregnancy to the end timely and took the fetus and placental out, after handling timely and properly, 22 cases retained the uterus, 4 cases had subtotal hysterectomy because of hematorrhea difficult to control, 2 cases had total hysterectomy because of big area of uterine apoplexy and being ineffectually handled. Placental abruption with uterine apoplexy are badly dangerous to the lives of mother and infant. The pregnancy should be made to the end timely. But uterine apoplexy is not the indication of subtotal hysterectomy. Most uterus can be retained and the incidences of the death of mother and infant can be decreased if being handled timely and properly.

Field of study: Medicine
Exact solutions of accelerated flows for a Burgers' fluid. I. The case gamma

In this paper, we derive the exact solutions of accelerated flows for a Burgers’ fluid. The expressions for the velocity field and the associated tangential stress to the flows of a Burgers’ fluid induced by the accelerating flat plate are established when the relaxation times satisfy the condition γ λ 2 / 4 . Employing the Laplace transform, the exact solutions are developed for the following two problems: (i) constantly accelerating flow and (ii) variable accelerating flow. The corresponding solutions for a Newtonian, second grade, Maxwell and Oldroyd-B fluids appear as the limiting cases of the presented analysis.

Field of study: Mathematics
Studies on Solar Radiation as a Means of Eradicating Rhyzopertha dominica (Fab.) in Wheat

The experiment was designed to harness solar energy and to evaluate the effect of colour of polythene storage bags, (black, blue, green, red and yellow) for the management of Lesser grain borer, Rhyzopertha dominica (Fab.) in stored wheat. The studies also included to find out the effective duration of exposure to solar radiation and its effect on seed germination. The mortality of test insect increased while seed germination decreased with the increase in duration exposure. Maximum infestation of R. dominica was eliminated by exposing the infected grains to solar radiation for 24 h in black polythene bag.

Field of study: Biology
Variable importance in binary regression trees and forests

We characterize and study variable importance (VIMP) and pairwise variable associations in binary regression trees. A key component involves the node mean squared error for a quantity we refer to as a maximal subtree. The theory naturally extends from single trees to ensembles of trees and applies to methods like random forests. This is useful because while importance values from random forests are used to screen variables, for example they are used to filter high throughput genomic data in Bioinformatics, very little theory exists about their properties.

Field of study: Computer science
Development of the Early Continental Crust. Part 1. Use of Trace Element Distribution Coefficient Models for the Protoarchean Crust

The original continental crust developed as the residue from fractional crystallization of the mantle–crust system. Using measured distribution coefficients for K, Rb, Ba, Sr, La, Ce, Eu, Yb, and Ni, several crystallization models are tested for conformity with regional geochemical estimates of continental crustal composition.In spite of the uncertainties and approximations the predicted concentrations agree reasonably well with observation, except in the case of Yb.

Field of study: Environmental science
Population Genetic Diversity and Phylogenetic Characteristics for High-Altitude Adaptive Kham Tibetan Revealed by DNATyperTM 19 Amplification System

Tibetans residing in the high-altitude inhospitable environment have undergone significant natural selection of their genetic architecture. Recently, highly mutational autosomal short tandem repeats were widely used not only in the anthropology and population genetics to investigate the genetic structure and relationships, but also in the medical genetics to explore the pathogenesis of multiple genetic diseases and in the forensic science to identify individual and parentage relatedness. However, genetic variants and forensic efficiency of DNATyperTM 19 amplification system and genetic background of Kham Tibetan remain uncharacterized. Thus, we genotyped 19 forensic genetic markers in 11,402 Kham Tibetans to gain insight into the genetic diversity of Chinese high-altitude adaptive population. Highly discriminating and polymorphic forensic measures were observed, which indicated that this new-developed DNATyper 19 PCR amplification is suitable for routine forensic identification purposes and Chinese national DNA database establishment. Pairwise genetic distances among the comprehensive population comparisons suggested that this high-altitude adaptive Kham Tibetan has genetically closer relationships with lowlanders of Tibeto-Burman-speaking populations (Chengdu Tibetan, Liangshan Tibetan, and Liangshan Yi). Genetic substructure analyses via phylogenetic reconstruction, principal component analysis, and multidimensional scaling analysis in both nationwide and worldwide contexts suggested that the genetic proximity exists along the linguistic, ethnic, and continental geographical boundary. Further studies with whole-genome sequencing of modern or archaic Kham Tibetans would be useful in reconstructing the Tibetan population history.

Field of study: Biology
Experimental and Simulation Study of Resistive Helical HTS Fault Current Limiters: Quench and Recovery Characteristics

Resistive type fault current limiters (SFCLs) have attracted lots of attention from research interests and engineering applications, due to their self-triggering, fast and effective fault current limitation ability. Fast recovery of SFCL after quench is highly attractive, yet still remains challenge when recover with load compared to recovering without load. We investigated the dependence of recovery time of a helical SFCL coil on the ratio of prospective current over critical current <italic>I</italic><sub>pros</sub>/<italic>I</italic><sub>c</sub>. A multilayer simulation model was built in MATLAB/Simulink to investigate the electro-thermal behavior of SFCL coil during a fault and recovery period, and the model was validated by experimental results. Quench simulations were carried out under different <italic>I</italic><sub>pros</sub>/<italic>I</italic><sub>c</sub>, ranging from 15 to 119 and in different recovery conditions including recovery with load condition and recovery without load condition, while keeping the fault duration of 100 ms. We observed that the SFCL coil reached 85 K and 195 K at the time when the fault was cleared, in the quench tests with <italic>I</italic><sub>pros</sub>/<italic>I</italic><sub>c</sub> = 15 and 119, respectively. SFCL coil recovered without load in 0.5 s to 10 s, depending on the ratio of <italic>I</italic><sub>pros</sub>/<italic>I</italic><sub>c</sub>.

Field of study: Physics
Diagnostic Dilemmas in Acute Intermittent Porphyria

To present the importance of early diagnosis of acute intermittent porphyria (AIP) in patients with atypical presentation and discuss the diagnostic problems encountered in this case.  A 15-year-old girl presented with upper respiratory tract infection, fever, seizures and abdominal pain. An initial diagnosis of encephalitis was made. She received antiviral drugs and anticonvulsants. Two weeks later, she developed progressive flaccid quadriplegia and facial weakness. She also developed respiratory paralysis and was intubated. Cytoalbuminous dissociation was seen in the cerebrospinal fluid. A diagnosis of severe Guillain-Barré syndrome was made.  The patient received a course of intravenous immunoglobulins which did not result in any clinical improvement. Plasmapheresis, started after 12 weeks, led to partial improvement. The patient continued to have attacks of seizures, abdominal pain and vomitting with severe quadriparesis. A repeat screening test for urine porphyrins was positive, and AIP was confirmed by specific porphobilinogen deaminase in the blood. The patient was treated with large doses of intravenous glucose, followed by injections of hematin. The patient improved remarkably. She was extubated, discharged from Intensive Care Unit and started on a rehabilitation program.  This patient was initially diagnosed erroneously with a negative screening test for AIP and consequently treated inappropriately. The proper diagnosis was made after repeating the screening test followed by specific tests of porphobilinogen deaminase.

Field of study: Medicine
Forgotten landscapes: Public attitudes and perceptions of coastal saltmarshes

As the field of public perceptions research continues to grow alongside an increasing recognition of the importance of understanding the complex interactions between society and the natural environment, this needs to consider all types of ecosystem, habitat and species. Although interest in public perceptions towards the global seas and coasts is increasing, the field is dominated by research focused on charismatic environments and species (e.g. coral reefs or marine mammals), and specific activities or human interactions with the seas and/or coasts (e.g. beach use, marine renewable energy). Whilst there has been some research on beaches and sand dunes, this is the first discrete piece of research which evaluates public views on the less ‘attractive’ coastal fringe environments, such as saltmarshes or mudflats, particularly in temperate regions. This paper presents the findings of a national survey (n = 1136) that aimed to understand public awareness and attitudes towards Welsh saltmarshes, and the ecosystem services and benefits derived from such systems. Through the questionnaire, we found limited public awareness, and a high amount of uncertainty, associated with saltmarshes and their societal benefits, indicating a need to foster and enhance current levels of public knowledge and understanding of saltmarshes, and their role within the wider coastal landscape. The influence of a range of respondent characteristics on perceptions. Given the position of salt marshes at the land-sea interface, the myriad of socio-ecological interactions they experience, and ongoing efforts to develop effective complementary marine and land-based planning and management, it is increasingly apparent that understanding public perceptions towards saltmarshes is crucial. This study contributes to the evidence base of public attitudes for the more commonly under-valued coastal fringe environments, such as saltmarshes.

Field of study: Environmental science
On local parton-hadron duality

We show that in the Lund string fragmentation model fore+e−-annihilation events, the final state hadrons are to a large extent determined by the (colour connected) multiparton state. To that end we define a )timelike) curve (thex-curve) in energymomentum space directly from the parton state. The fragmentation process produces hadrons with momenta along this curve, with limited deviations away from it. At high energies the fluctuations in the parton cascade dominate over the fluctuations in the hadronization. Therefore a good approximation to the inclusive momentum distributions is obtained simply by partitioning thex-curve into pieces (“hadrons”) with equal mass. This is a direct realization of the notion of parton-hadron duality.

Field of study: Physics
Structural basis of DNA flexibility.

It has been recently shown by us, on the basis of crystal structure database that the flexibility of B-DNA double helices depends significantly on their base sequence. Our model building studies further indicated that the existence of bifurcated cross-strand hydrogen bonds between successive base pairs is possibly the main factor behind the sequence directed DNA flexibility. These cross-strand hydrogen bonds are, of course, weaker than the usual Watson-Crick hydrogen bonds and their bond geometry is characterized by relatively larger bond lengths and smaller bond angles. We have tried to improve our model structures by incorporating non-planarity of the amino groups in DNA bases due to the presence of lone pair electrons at the nitrogen atoms. Energy minimization studies have been carried out by using different quantum chemical methods, whereby it is found that in all cases of N-H....O type cross-strand hydrogen bonds, the bond geometry improves significantly. In the cases of N-H....N type hydrogen bonds, however, no such consistent improvements can be noticed. Perhaps the true picture would emerge only if all the other interactions present in the DNA macromolecule could be appropriately taken into account.

Field of study: Biology, Chemistry, Physics
Second language acquisition and first language loss in adult early bilinguals: exploring some differences and similarities

This study compares the linguistic knowledge of adult second language (L2) learners, who learned the L2 after puberty, with the potentially ‘eroded’ first language (L1) grammars of adult early bilinguals who were exposed to the target language since birth and learned the other language simultaneously, or early in childhood (before age 5). I make two main claims: (1) that the L1 grammar of bilinguals at a given stabilized state (probably endstate) resembles the incomplete (either developing or stabilized) grammars typical of intermediate and advanced stages in L2 acquisition; and (2) that despite similar patterns of performance, when language proficiency is factored in, early bilinguals are better than the L2 learners, probably due to exposure to primary linguistic input early in childhood. I offer empirical evidence from an experimental study testing knowledge of the syntax and semantics of unaccusativity in Spanish, conducted with English-speaking L2 learners and English-dominant Spanish heritage speakers living in the USA. I consider recent treatments of unaccusativity and language attrition within the generative framework (Sorace, 1999; 2000a; 2000b), that offer a unifying account of the formal parallels observed between these two populations I discuss how input, use and age may explain differences and similarities in the linguistic attainment of the two groups.

Field of study: Linguistics
Adaptive Resource Allocation Algorithm Resarch In MIMO-OFDM Systems

In this paper,an adaptive modulation algorithm is proposed in order to minimize the total transmission power under given BER and satisfy the fixed transmission rate in MIMO-OFDM systems.For this purpose,and adaptive algorithm with low complexity is described,and the modifications on power allocation and step-size load of Hughes-Hartogs and variable step-bit algorithms are implemented.The simulation results show that,by the modified algorithm,the MIMO-OFDM system is improved in performance while is reduced in complexity.

Field of study: Engineering