nils-herrmann/clean_scirepeval huggingface dataset:
Two key challenges for biodiversity: discontinuities and synergisms

The survival outlook for biodiversity is being profoundly and adversely influenced by the twin phenomena of discontinuities and synergisms. So potent are their impacts that they may well cause the mass extinction to overtake us more swiftly and extensively than is often expected. Despite their importance, however, we know all too little about these phenomena. They remain almost entirely a black hole of research. This paper, being an introduction to the special issue, presents a short selection of both phenomena, with an evaluation of their impacts on biodiversity. It concludes with an overview of the human enterprise and its probable future repercussions for biodiversity.

Field of study: Environmental science
Differential Pulse Voltammetric Determination of Two Antivirus Nucleoside Analogues in Blood of Rat

Differential pulse voltammetry was applied to the simultaneous determination of two antivirus nucleoside analogues,aciclovir and penciclovir,in the rat metabolic blood at an ethylenediamine modified glassy carbon electrode.Moreover,the mechanism of the electrode modification and the electrode reaction was investigated and discussed.In the pH 2.56 Britton-Robinson buffer,both aciclovir and penciclovir had a sensitive irreversible oxidation peak on the modified glassy carbon electrode.The peak potentials were 1.20 V and 1.17 V for these two medicines,respectively.Under the optimal conditions,the peak current was linear with its concentration in the range of 0.20-4.0 mg/L for aciclovir and 0.02-0.40 mg/L for penciclovir.The detection limits were 77 μg/L for aciclovir and 12 μg/L for penciclovir.Furthermore,chemometrics of classical least squares(CLS),principal component regression(PCR) and partial least squares(PLS) were applied to resolve the overlap spectra of the admixture of the two medicines,without troublesome procedures of separation and purification.The proposed method has been applied to the determination of the two antivirus nucleoside analogues in the metabolic blood of mouse.

Field of study: Chemistry
Self-infusion of GABA(A) antagonists directly into the ventral tegmental area and adjacent regions.

This study used an intracerebral self-administration paradigm in rats to determine if blockade of GABA A receptors in the ventral tegmental area (VTA) has a reinforcing effect. Rats quickly learned to self-infuse a picrotoxin solution into the anterior VTA; rats discriminated the lever that produced picrotoxin infusions from the lever without consequences; and when the response requirement was increased, rats increased response levels for picrotoxin infusion. The reinforcing effect of picrotoxin was site-specific: Anterior VTA regions supported vigorous self-infusions, but not the posterior VTA, substantia nigra, or lateral hypothalamus. Muscimol, a GABA A agonist, disrupted picrotoxin self-infusion, but bicuculline, a GABA A antagonist, was self-infused into the VTA. The results suggest that blockade of GABA A receptors in the anterior VTA is reinforcing and that functional organization of the GABA systems within the VTA is heterogeneous.

Field of study: Biology, Psychology
Solid-state memcapacitive device based on memristive switch

This article describes the implementation of a solid-state memcapacitor based on combination of a memristor and traditional metal–insulator–metal capacitor. A device with an area of has been fabricated and tested. The structure has been simulated and analyzed using circuit equivalents with parameters obtained from measurements. The memristor is represented by a -type model. The performance of the memcapacitor is discussed, and some methods to improve it are proposed.

Field of study: Materials science
Nuclear-charge polarization at scission in the 12 MeV proton-induced fission of 232Th

The most probable charges of secondary fragments, produced after neutron evaporation from primary fragments, have been evaluated using fractional cumulative and mass yields in the 12MeV proton-induced fission of 232Th . The nuclear-charge polarization of primary fragments at scission has been obtained by correcting the most probable charge of secondary fragments for neutron evaporation. The fragment mass dependence of the nuclear-charge polarization at scission shows good agreement with that for thermal neutron-induced fission of 235U , indicating that the nuclear-charge polarization is nearly insensitive to mass and excitation energy of the fissioning nucleus for asymmetric fission in the actinide region.

Field of study: Physics
Biochemical, biophysical and preliminary X-ray crystallographic analyses of the fusion core of Sendai virus F protein.

It is emerging that enveloped viruses may adopt a unique entry/fusion mechanism; in paramyxoviruses, including Sendai virus (SeV), the attachment protein HN (or its homologue H or G) binds a cellular receptor which triggers conformational changes of its fusion protein, F. There are at least three conformations of the F protein in the current fusion model: the pre-fusion native conformation, the pre-hairpin intermediate conformation and the post-fusion coiled-coil conformation. The fusion mechanism of SeV, a member of the Paramyxoviridae family, has been well established and several structural and functional domains or modules have been proposed from studies of its F protein. However, biochemical and biophysical studies of the heptad-repeat (HR) regions (HR1 and HR2) have not been systematically carried out. HR1 and HR2 strongly interact with each other to form a stable six-helix coiled-coil bundle as the post-fusion conformation. In this study, a single-chain HR1-linker-HR2 protein of SeV was prepared in an Escherichia coli expression system and biochemical and biophysical analyses showed it to form a typical six-helix coiled-coil bundle; its trigonal crystals diffracted X-rays to 2.5 A resolution. The crystal structure will help to reveal the structural requirements of the post-fusion coiled-coil conformation of SeV F protein.

Field of study: Chemistry
Genetic diversities of two geographical populations of Pelodiscus sinensis by ISSR

To assess the genetic diversity of the Pelodiscus sinensis,inter-smiple sequence repeat(ISSR)molecular marker was applied from two Pelodiscus sinensis populations(Huai River population and Tai-wan population).Eight ISSR primers were selected from 32 ones.A total of 77 reproducible DNA fragments were amplified from all the 37 individuals,in which 47 fragments were polymorphic,and the percentage of polymor-phic loci was 61.04%.The percentages of polymorphic loci of two populations were 59.57% and 51.06%;the Nei's gene diversities were 0.1657 and 0.1524;the Shannon's information indices were 0.2164 and 0.1977,re-spectively.The Huai River population had higher genetic diversity than that of Taiwan population.The average genetic distance was 0.0837 among 37 individuals.UPGMA analysis showed that 37 individuals were divided into two clusters corresponding to two populations.The results indicated that the two populations have lower ge-netic diversity,and the cultured populations might form their own stable genetic structures through multi-generation and artificial breeding.

Field of study: Agricultural and Food sciences
An ultrastructural study of cardiac myocytes in postmyocardial infarction ventricular aneurysm representative of chronic ischemic myocardium using semiquantitative and quantitative assessment.

To elucidate the characteristic myocytic changes in chronic ischemic myocardium, an electronmicroscopic (EM) study was carried out in surgically excised postmyocardial infarction left ventricular aneurysm (LVAN) (n = 15) using semiquantitative (in all 15 cases) and quantitative assessment methods (in 10 cases). The control group, representing normal ultrastructure, included left ventricular endomyocardial biopsy specimens of sick sinus syndrome (SSS) (n = 3), Wolff-Parkinson-White (WPW) Syndrome (n = 1), and intraoperative left ventricular endomyocardial biopsy in mitral stenosis (MS) (n = 3). Myocardial condition was assessed at the ultrastructural level according to the severity of morphologic changes, first semiquantitatively, thereafter with the use of the Image Processor-Analyzer LUZEX III for morphometric analysis. The most marked EM findings were mitochondrial regressive changes, glycogen accumulation, nuclear deformities, increased rough-surfaced endoplasmic reticulum at the perinuclear portion, lysis of myofibrils, and myofibrillar degeneration. The quantitative analysis revealed significant (p < 0.05) increase of glycogen deposition, only at the perinuclear portion in the LVAN group. The myofibril to mitochondria ratio at the intercalated disc (ID) portion of the cardiac myocytes significantly increased (p < 0.01) in the LVAN group as compared with the normal control group. Light microscopically evaluated quantitative analysis, using toluidine-blue stained semithin sections which underwent EM observation, showed that the fractional area of interstitial fibrous tissue was significantly increased in the LVAN group compared to the normal controls (p < 0.01). These results signify that in chronic ischemic myocardium, decreased consumption of glycogen in oxidative phosphorylation occurs in the surviving myocytes, and that hypertrophy of the myocytes appears. The results of this study may lead to the proper ultrastructural interpretation of biopsied human myocardium, regardless of etiology.

Field of study: Biology, Medicine
Comparison of the droplet size spectra produced by rotary atomizers and hydraulic nozzles under simulated aerial application conditions

A wind tunnel was used to characterize the droplet size spectra of liquid sprays from several different atomizers and nozzles used under simulated aerial application conditions. The atomizers included a D8–46 nozzle, a Through Valve Boom (TVB) nozzle, and rotary cage and drum atomizers. The D8–46 hydraulic nozzle was evaluated, using water, at orientations of 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90° relative to 145 and 180 km/h airstreams. The TVB nozzle was evaluated using water, water with isopropyl alcohol, and water with a non‐ionic surfactant at airstream velocities between 130 and 180 km/h. The rotary atomizers were evaluated at different rotation rates, flow rates of water and an insecticide, in 130 and 180 km/h airstreams. The volumetric droplet size spectra parameters (Dvo.x) decreased as the angle of the D8–46 nozzle and the airstream velocity increased. Empirical models were developed to predict these values for different windspeed and nozzle angle conditions. The TVB nozzle produced ...

Field of study: Agricultural and Food sciences
Human and Murine Embryonic Stem Cell-Derived Cardiomyocytes Serve Together as a Valuable Model for Drug Safety Screening

Screening of drug safety is typically performed in diverse non-human healthy species with an intact repolarization reserve. Nevertheless, these drugs are later applied in diseased humans with a reduced repolarization reserve. It would be optimal to set up a preclinical screening tool to estimate the proarrhythmic potential of drugs in human cardiac tissue with a reduced repolarization reserve in vitro.  In our study spontaneously beating human embryonic stem cell-derived cardiomyocytes clusters (hESCM) and murine ES cell-derived cardiomyocytes (mESCMs) were plated onto micro-electrode arrays (MEAs) to record the extracelluar field potentials (FPs) as well as effects of several antiarrhythmic drugs. In line with clinical observations the class III antiarrhythmic drugs (±)-sotalol, E4031 and class I antiarrhythmic drug quinidine led to a prolongation of the cardiac repolarization phase (FP duration, FPdur) and a decrease of the FP frequency. Verapamil (a class IV antiarrhythmic drug) decreased the FP frequency and shortened FPdur. Both, quinidine and verapamil, but not (±)-sotalol or E4031 decreased conduction velocities in hESCM clusters. Moreover, (±)-sotalol exerted stronger effects on FPdur in early developmental stages of hESCMs, as proof for a reduced repolarization reserve. The EC50 of the (±)-sotalol-induced prolongation of the FPdur was higher in mESCMs than in hESCMs implying species-dependent differences in cardiac repolarization. Likewise, the incidence of drug-induced early recurrent depolarization (ERDs) was higher in mESCMs than hESCMs.  The combined measurement of drug effects on FP parameters in hESCMs and mESCMs serves as a reliable in vitro model for preclinical studies of drug safety.

Field of study: Biology, Chemistry
Extraction Studies for the Modified Nevis Synchrocyclotron

Computer studies of a regenerative beam extraction system using magnetic peeler-regenerator have been performed. We have also investigated the use of a time varying first harmonic magnetic bump as a beam stretcher. The results indicate, that we can expect a turn separation of the order of 0.8 in. at the mouth of the magnetic channel. The time varying bump makes it possible to stretch the external beam over most of the RF-off time of the acceleration cycle. For the, magnetic channel, a current configuration has been found which does not perturb the main cyclotron field outside itself and reduces the field by 4 kG inside the channel. The step from no field to full field is only 0.2 in. This 4 kG field extending over a distance of 20-in. is sufficient to lead the beam out of the machine.

Field of study: Physics
NEMO: Novel and efficient multicast routing schemes for Hybrid Data Center Networks

Multicast places an important role in group communication in data center networks (DCN’s). As the rapid development of DCN’s, researchers elegantly integrate wireless connections with wired DCN to form a new structure, Hybrid Data Center Network (HDCN), which can improve the performance of multicast significantly with wireless gains. In this paper, we present two novel and efficient multicast routing schemes (named NEMO-Group and NEMO-Cluster) for HDCN to achieve fast multicast tree construction and simple network traffic routing. We theoretically analyze the expected performance improvement of the two designs with different wireless transmission ranges. To the best of our knowledge, we are the first to discuss the sender-driven polynomial-time multicast routing schemes for HDCN, and to estimate the upper and lower bound of wireless gains. Moreover, our numerical results show that with the same construction cost, NEMO’s reduce 15%–40% traffic and improve 10%–40% throughput than the existing multicast protocols.

Field of study: Computer science
Effect of intensive flux creep on voltage-current curves and thermal stability of high T/sub c/ composite conductors

Basic dissipative and voltage-current curves of high-T/sub c/ conductors with normal metal matrix are obtained directly from the description of thermally activated flux creep. The effect of different criteria for j/sub c/ is discussed, and current sharing between superconducting and normal layers is analyzed. A comparison with the critical-state model is given. Intensive creep is shown to change considerably the real characteristics of high-T/sub c/ composites, increasing their thermal stability.<<ETX>>

Field of study: Physics
Sm0.5Sr0.5CoO3 − δ–BaCe0.8Sm0.2O3-δ composite cathodes for proton-conducting solid oxide fuel cells

Electrochemical performance of composite cathodes consisted of an electron–oxygen–ion mixed conductor, Sm0.5Sr0.5CoO3 − δ (SSC), and a proton conductor, BaCe0.8Sm0.2O3 − δ (BCS) was investigated for intermediate temperature solid oxide fuel cells with proton-conducing ceramics as the electrolytes. Interfacial polarization resistance of the composite decreased with SSC content to the minimum at 60 wt.% SSC and then increased. Firing temperature of the cathodes also affected the resistance, and high performance cathode could be obtained by firing at 1050 °C. The minimum interfacial polarization resistance was 0.21 Ω cm2 at 700 °C, where powder density of 0.24 W/cm2 was achieved with humidified hydrogen as the fuel and ambient air as the oxidant. The low interfacial polarization resistance suggests promise applications of SSC–BCS composites as the cathodes for SOFCs based on proton-conducting electrolytes.

Field of study: Materials science
[Pathological fantasies in children].

To develop a clinical classification of pathological fantasies (fantasy syndrome) in children and adolescents regardless of nosological attribution.



We examined 109 patients, aged 3-16 years, using psychopathological and instrumental (EEG and MRI) methods.



Authors developed the clinical typology of pathological fantasies in children with different mental diseases and disorders. The following variants of fantasy syndromes were singled out: 1. fantasizing with sensorealization of mental images; 2. fantastic stories (subdivided into 5 different variants): 2.1 easily provoked fantasies with situation-conditioned content; 2.2. fantasizing with increased falsehood; 2.3. sexual allegations and self-accusations; 2.4. fantasizing about imaginary worlds; 2.5. fantasies about a fictional friend); 3. playing transformation; 4. fantasies with a predominance of specific hobbies.

Field of study: Medicine, Psychology
Competition between Pi-coupling and FFLO modulation in SF/SF atomic thickness bilayers

We present the detailed theoretical study of a heterostructure comprising of two coupled ferromagnetic superconducting layers. Our model may be also applicable to the layered superconductors with alternating interlayer coupling in a parallel magnetic field. It is demonstrated that such systems exhibit a competition between the nonuniform Larkin-Ovchinnikov-Fulde-Ferrel (FFLO) state and the superconducting state where the sign of the superconducting order parameter is opposite in adjacent layers. We determine the complete temperature-field phase diagram both in the cases of low and strong interlayer coupling. In the former we obtain a new Pi-phase inserted within the FFLO phase and located close to the usual tricritical point, whereas in the latter the bilayer in the state reveals a very high paramagnetic limit and the phenomenon of field-induced superconductivity.

Field of study: Physics
Management of Network Devices based on LDAP Directory Service

The kernel of management of network devices which is based on LDAP directory service is used with LDAP service storing and information accessing. At first we introduce definition, structure and principle of LDAP Protocol and give an example to explain how to configure OpenLDAP by Linux. And then we specify the directory structure and data schema of information which is stored in LDAP. At last we develop software for management based on Web in Java.

Field of study: Computer science
Greenhouse gas emissions from concrete can be reduced by using mix proportions, geometric aspects, and age as design factors

Author(s): Miller, SA; Horvath, A; Monteiro, PJM; Ostertag, CP |  With increased awareness of the emissions of greenhouse gases (GHGs) and the significant contribution from the cement industry, research efforts are being advanced to reduce the impacts associated with concrete production and consumption. A variety of methods have been proposed, one of the most common being the replacement of cement as a binder in concrete with supplementary cementitious materials, such as fly ash (FA), which can have lower environmental effects. The use of FA can change the kinetics of the hydration reactions and, consequently, modify the evolution of the concrete strength over time. Yet the influence of designing structural elements to obtain the required strength at later ages has not been examined in terms of their influence on global warming potential (GWP) of concrete. This research investigates the influence of design age, in addition to mix proportions and geometric aspects, on the GWP associated with making beams, columns, and a concrete building frame. Findings suggest that while the GWP for beams is not highly dependent on concrete mixture strength, the GWP for columns is dependent on strength, thus the influence of required strength at later ages influences GWP of making columns more so than beams. For the concrete frame analyzed, a potential 45% reduction in GWP, depending on mix proportions and design age, was found. Using the findings from this research, the GWP associated with production of concrete in California could be reduced by approximately 1.8 million metric tons of CO2-eq emissions, equivalent to approximately 2% of all industrial GHG emissions in California.

Field of study: Environmental science
Contamination Characteristics and Degradation Behavior of Low-Density Polyethylene Film Residues in Typical Farmland Soils of China

Low-density polyethylene (LDPE) film residues left in farmlands due to agricultural activities were extensively investigated to evaluate the present pollution situation by selecting the typical areas with LDPE film application, including Harbin, Baoding, and Handan of China. The survey results demonstrated that the film residues were ubiquitous within the investigaed areas and the amount reached 2400–8200 g ha−1. Breakage rates of the film residues were almost at the same level in the studied fields. There were relatively small amounts of film residues remaining in neighboring farmland fields without application of LDPE film. The studies showed that the sheets of LDPE residues had the same oxidative deterioration, which was probably due to photodegradation instead of biodegradation. The higher molecular weight components of the LDPE film gradually decreased, which were reflected by the appearance of some small flakes detached from the film bodies. LDPE films in the investigated fields gradually deteriorated and the decomposing levels developed with their left time increasing. The degradation behaviors of LDPE films were confirmed by using Fourier transform infrared (FTIR), scanning electron microscopic (SEM), and gel permeation chromatography analyses.

Field of study: Agricultural and Food sciences
Spatial-Frequency Signal Alignment for Opportunistic Transmission

In this paper, we investigate opportunistic transmission based on signal alignment for multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) cognitive radio (CR) systems, where both primary and secondary users have multiple antennas. In the studied scenario, primary users are transmitting based on OFDM and secondary users generate interference-free transmission to the primary users by using both the spatial and frequency space leftover by the primary system. Moreover, inter- and intra-interference among secondary users are considered as well. The number of symbols that can be transmitted by each secondary user satisfying all interference-free constraints is obtained. Precoding matrix design will be discussed for perfectly- and partially-aligned transmission. Two chordal-distance based schemes, called as exhaustive search algorithm and heuristic algorithm, will be developed for each case. Compared to the traditional time-division multiple-access (TDMA) scheme, the proposed scheme can support more interference-free symbols to be transmitted by secondary users simultaneously.

Field of study: Engineering
Formation of Organic Pigment Films by Photochemical Reduction of Surfactants Containing an Azobenzene Group

A copper phthalocyanine 1 thin film and photoimage were formed on a polyester film by irradiation of an aqueous dispersion containing a surfactant with an azobenzene group 2a, dispersed 1, hydroquinone 3 and 0.1 M HCl. A spectroscopic study showed that the photochemical reduction of 2a with 3 leads to the deposition of 1.

Field of study: Chemistry