nils-herrmann/clean_scirepeval huggingface dataset:
Establishment and characterization of a CHO cell line producing a secreted form of human ciliary neurotrophic factor: neuroprotective effects of the recombinant protein.

Human ciliary neurotrophic factor (CNTF) was inserted into a mammalian expression vector linked to the prepro sequence of human nerve growth factor. A Chinese hamster ovary cell line was established by resistance to neomycin and the plasmid integrated DNA was amplified using the metallothionein gene. This cell line contained several hundred copies of the human CNTF gene and produced an NH2 terminal truncated form of human CNTF (22 kDa) which was secreted into the medium. Although the copy number of the human CNTF gene was high and its mRNA was actively transcribed, the recombinant protein secreted into the medium constituted only 35-40% of the total amount of human CNTF synthesized by these cells. Both wild-type human CNTF produced in bacterial cells and the human CNTF obtained by forced secretion were effective in protecting hippocampal pyramidal neurons from injury induced by glucose deprivation, a form of excitotoxic neurodegeneration.

Field of study: Biology
Temperature variation of the luminescence spectra in crystals

The luminescence spectra in cubic mixed crystals (0.6<x<1) grown by MBE have been studied in an energy range of around 2 eV as a function of temperature between 4.2 and 300 K. The observed luminescence is related to intra-ion optical transitions between the 3d electronic levels of perturbed by a crystal field. The luminescence displays a non-monotonic temperature dependence with a minimum at about 50 K. The occurrence of the minimum depends on the Mn molar fraction only very weakly. The temperature variation of the luminescence transition results mainly from the effect of screening of the Coulomb repulsion force between d electrons and from variation of the crystal field potential due to thermal lattice dilation and electron - phonon interaction.

Field of study: Materials science
Tunneling between superconductors

Josephson's calculations showed that for two superconductors separated by an oxide there may exist an osciliating supercurrent of frequency 2e V/h (V is applied voltage) and a possible d-c supercurrent at zero voltage. The calculations are reproduced by the method of the thermodynamic Green's function that allows generalization to superconductors with strong electron-phonon coupling. A simple prediction for the temperature dependence of the d-c supercurrent is shown to follow from the theory.

Field of study: Physics
AQUArIUM - A suite of software measures for HCI quality evaluation of ubiquitous mobile applications

Five characteristics for HCI evaluation in ubiquitous applications are selected.Twenty-four quality measures to evaluate these five characteristics are proposed.A theoretical and empirical validations were performed. Ubiquitous computing has changed the way users interact with technology. Its applications are everywhere, supporting users in everyday activities in a transparent way with little or no need for attention. To ensure the adoption of these applications, it is essential to assess the quality of the interaction with its users. To do that, measurements can be applied to obtain data about quality characteristics in a software product. In a previous study about quality characteristics and software measures for ubiquitous computing, we have identified a gap in the literature regarding software measures for evaluating essential quality characteristics in ubiquitous systems. Therefore, this paper proposes a suite of well-defined software measures (twenty-four in total), called AQUArIUM, to evaluate human-computer interaction (HCI) in ubiquitous applications for mobile devices. These measures address five quality characteristics of ubiquitous computing: Context-awareness, Mobility, Attention, Calmness and Transparency. The proposed suite was validated theoretically and empirically. The results showed not only that the suite is feasible, but also that it indicates specific problems of HCI quality, which are helpful in improving the evaluated ubiquitous mobile application.

Field of study: Computer science, Engineering
Towards limited scale-free topology with dynamic peer participation

Growth models have been proposed for constructing the scale-free overlay topology to improve the performance of unstructured peer-to-peer (P2P) networks. However, previous growth models are able to maintain the limited scale-free topology when nodes only join but do not leave the network; the case of nodes leaving the network while preserving a precise scaling parameter is not included in the solution. Thus, the full dynamic of node participation, inherent in P2P networks, is not considered in these models. In order to handle both nodes joining and leaving the network, we propose a robust growth model E-SRA, which is capable of producing the perfect limited scale-free overlay topology with user-defined scaling parameter and hard cut-off. Scalability of our approach is ensured since no global information is required to add or remove a node. E-SRA is also tolerant to individual node failure caused by errors or attacks. Simulations have shown that E-SRA outperforms other growth models by producing topologies with high adherence to the desired scale-free property. Search algorithms, including flooding and normalized flooding, achieve higher efficiency over the topologies produced by E-SRA.

Field of study: Computer science
Hydrodynamic sorting and ecology of a Pleistocene mammalian assemblage from California (U.S.A.)

Bulk sediment samples and surface collections were made from deltaic distributary channel deposits for a paleoecological investigation in the Late Pleistocene Montezuma Formation at Rodeo, California (U.S.A.). Over 1300 kg of bulk samples were screenwashed, and all particles greater than 1.3 mm were saved for analysis. About 3400 identifiable vertebrate specimens of 36 genera (40 species) were recovered. Variations from the expected per cent preservation for selected skeletal elements of small mammal general (N = 1889), for elements of nine rodent genera compared (N = 1136), for cheek teeth of six rodent genera (N = 447), and sediment particle size distribution of a representative locality (464 kg sample) provide qualitative and quantitative information about the effects of hydrodynamic sorting on the preservation of small mammal fossils. Elements which are small, long, and slender, or have large surface to volume ratios are extremely rare. Frequency of preservation and size of cheek teeth decrease in the order: M1, M2, P4-M3, P3. The greatest mass of sediment is in the 1.3–1.4 mm interval where 25% of the identifiable mammal bones and teeth appear. About 80% of the fossils are in the 1.3–3.0 mm range. Hydrodynamic sorting is responsible for the low per cent preservation and relative abundance of each of three species from the Rodeo site (Reithrodontomys raviventris, Scapanus latimanus, and Sorex sp.). Size and shape of skeletal elements are the critical factors, not distance of transport. To ascertain if a species belonged to the community near the site of deposition and to determine its original relative abundance there requires study of many factors in addition to sorting.

Field of study: Environmental science, Geography
The Development of Aggressive Mental Models in Young Children

This study was undertaken to examine why a previous study revealed that children inaccurately recalled “seeing” violence in a nonviolent cartoon clip. We used a 2 (still photo vs. video clip) × 2 (action hero vs. neutral character) repeated measure experimental design and showed preschoolers (33–60 months) two photos and two video clips. Children were asked to tell a story about what might happen next. In addition, parents filled out a brief questionnaire. Results indicate that first, children whose parents reported that they had never been exposed to violent cartoons gave fewer aggressive responses than those who had seen one. Second, character type appears to have a greater effect on children's aggressive mental models than the narrative does. Overall, the effect of stereotypical action characters (as compared to neutral characters) is greater than it is for the video clip versus still-photo manipulation. Third, older children provided more aggressive story endings to the action character in the video sequence compared to younger children who saw the neutral character in the still photo or the neutral character in the video sequence. In sum, a single exposure to action cartoons may help very young children establish mental models for aggression. Second, both older and younger children are influenced by action cartoons, but older children are better able to incorporate story information whereas younger children focus on character appearance. Results are discussed in terms of mental models and child development.

Field of study: Psychology
Studies of operant and reflexive key pecks in the pigeon.

The duration of pigeons' key pecks was studied in three experiments. Experiment I revealed that key pecks early in exposure to continuous reinforcement were of short duration, as were key pecks observed on an omission procedure in which pecks prevented food delivery. Key pecks later in exposure to continuous reinforcement, and those that occurred on positive automaintenance procedures, were of long duration. In Experiment II, pigeons were exposed to fixed-interval and fixed-ratio reinforcement schedules, and durations were recorded separately for each quarter of each interval or ratio. On fixed interval, durations were shorter in the first quarter of each interval than in subsequent quarters; on fixed ratio, durations were longer in the first quarter of the ratio than in subsequent quarters. These data parallel observations of concurrent operant responding and salivation in dogs. In Experiment III, pigeons were exposed to a discrete trial, differential-reinforcement-of-low-rate 6-sec schedule. Durations of responses in the first 2 sec of the trial were substantially shorter than those of responses that occurred later. The data from all three experiments support the view that the pigeon's "key peck" actually consists of two subclasses of peck, one reflexive and one operant.

Field of study: Biology, Psychology
A numerical solution for the inhomogeneous Dirichlet boundary value problem on a non-convex polygon

In this paper, we introduce an effective finite element scheme for the Poisson problem with inhomogeneous Dirichlet boundary condition on a non-convex polygon. Due to the corner singularities, the solution is composed of a singular part not belonging to the Sobolev space H2 and a smoother regular part. We first provide a generalized extraction formula for the coefficient of singular part, which is depending on the inhomogeneous boundary condition and the regular part. We then propose a stable finite element method for the regular part by the use of the derived formula. We show the H1 and L2 error estimates of the finite element solution for the regular part and the absolute error estimate of the approximation for the coefficient of singular part. Finally, we give some numerical examples to confirm the efficiency and reliability of the proposed method.

Field of study: Mathematics
At the borderline between exclusive and inclusive physics: Study of Drell-Yan fragments in the PANDA experiment (a preliminary simulation)

Here a preliminary study is presented concerning the detection of the normally unseen Drell-Yan fragments, possible in the PANDA experiment. To work as a multi-purpose apparatus, this experiment will record all the particles produced in the collisions between the antiproton beam and the target, with a rather wide acceptance. So detecting Drell-Yan dileptons with or without analyzing the other fragments is just a matter of applying cutoffs in the data analysis stage. The distribution of the products of 50000 typical Drell-Yan events is here simulated using a well-known generator code (Pythia-8). The resulting distributions are inserted within the PANDA acceptance region to analyze the chances of missing some searched fragment combinations, or of confusing different sets of particles. The most interesting result is that, due to the reduced phase space, the produced states are much simpler than one could imagine: i) almost 50% of the events just consist of a dilepton plus a nucleon-antinucleon pair; ii) practically all events present a nucleon-antinucleon pair; iii) the number of light particles (photons over an infrared cutoff and pions) is pretty small. The presented simulations show that it is possible to study experimentally some, or some aspects, of the most relevant final states, with good statistics and precision.

Field of study: Physics
The dopamine D1 antagonist reduces ethanol reward for C57BL/6 mice.

Dopamine D1 antagonist effects on behaviors related to obtaining and consuming ethanol remain unclear. The highly selective D1 antagonist ecopipam (SCH 39166), which has no effect on the serotonin system, was used to evaluate the role of D1 receptors in ethanol reward and its potential for treating alcohol abuse by determining its effect on several measures of ethanol reward in C57BL/6 (B6) mice.



Ecopipam (0.025-0.2 mg/kg) effects on instrumental and contingent consummatory responses and on noncontingent consummatory responses for ethanol and water reward were determined in food-restricted male mice trained to lever-respond for 12% ethanol delivered on a fixed ratio-4 reinforcement schedule. The mice were tested for 15-min sessions under preprandial (high-hunger and low-thirst) and postprandial (low-hunger and high-thirst) test conditions.



Ecopipam dose-dependently reduced instrumental and consummatory responses for ethanol and ethanol intake when tested under hunger- or thirst-motivated conditions with free access to water. Under thirst motivation with no access to an alternate fluid source, lever responses for ethanol and water were similar; however, ecopipam reduced responding for ethanol more than responding for water reward. When given concurrent free access to the same fluid delivered for lever pressing, animals made more contacts for ethanol than for water; ecopipam reduced free ethanol but not water contacts.



Ecopipam attenuated ethanol reward at doses that did not affect water reward, indicating an effect independent of reductions in motor system function or general motivation and arousal. Ecopipam also reduced ethanol reward to the same degree under hunger, thirst, or sated conditions, again indicating that it affected ethanol reward at doses that did not grossly affect general motivational states. These data suggest that ecopipam may reduce ethanol reward with few side effects and that it warrants further investigation as a pharmacological tool for treating alcohol abuse.

Field of study: Medicine
Surface enhancement of oxygen exchange and diffusion in the ionic conductor La2Mo2O9

Isotopic surface oxygen exchange and its subsequent diffusion have been measured using secondary ion mass spectrometry in the fast ionic conductor La2Mo2O9. A silver coating was applied to the sample surface to enhance the surface exchange process for dry oxygen. Contrary to previous studies performed using a wet atmosphere, no grain boundary diffusion tail was observed under these optimized dry exchange conditions. The activation energy for oxygen diffusion was found to be 0.66(+/- 0.09) eV at high temperature (>570 degrees C), and 1.25(+/- 0.01)eV at low temperature (<570 degrees C). Time-of-Flight secondary ion mass spectrometry was employed to investigate the correlation between the silver coating and the O-18 concentration on the sample surface. A close correlation between the presence of silver and oxygen incorporation on the surface was observed.

Field of study: Materials science
Problems and Countermeasures in the Development of Private Enterprises in Our Country

Since the reform and open policy,private enterprises have been greatly d eveloping.But,many problems exist such as unreasonable production and management structure,in perfect manage ment,unscientific administration decision,rigid talent system etc,due to the effects of factors inside and outside.As a resulf,some enterprises pace up and down only to be eliminated.To develo p sustaineably and steadily,they sh ould renew the thought modes,strengthen scientific and technological development ,enhance product innovation,attach importance to adsorbing talents and bringing about a sustainable develo pment.

Field of study: Agricultural and Food sciences
Characterization of non-planar peptide groups in protein crystal structures.

Peptide groups are generally assumed to be planar in protein structure, due to 'rigid' partial double bond character of peptide bonds, thus the value of peptide torsion angle omega should be restricted to 180 degrees for the usual trans form of peptide unit. However, on analyzing the ultra-high resolution protein crystal database, we find that in some cases, omega deviates >10 degrees from its usual value of 180 degrees, indicating significant non-planarity of peptide groups. Moreover, the non-planarity for most of the amino acids is found to be 'biased' towards values of omega smaller than 180 degrees. Similar trend for to is confirmed by the neutron diffraction data for proteins. The neutron diffraction database also reveals that non-planar peptide groups are generally correlated to 'pyramidal' structure of the peptide-nitrogen bonds. Consequently, the hydrogen atom of peptide group deviates from its planar position, as measured by the 'improper' torsion angle theta. Thus, we find that both the angles omega and theta point towards a significant amount of non-planarity of peptide groups, which cannot be ignored. The role of peptide nonplanarity in protein function is, however, not yet clear.

Field of study: Biology, Chemistry, Physics
Consequences of root growth kinetics and vascular structure on the distribution of lateral roots

It has been proposed that the acropetal initiation of lateral roots is a built-in process specified as part of the general process of cell division and differentiation in the parent root tip. Conversely, it is commonly reported that root branching is essentially a variable feature. In the present study, the interlateral distance along the parent root has been investigated using three banana varieties (Musa spp.) grown in two substrates. The pattern of lateral root initiation was obscured by variations of root growth patterns and vascular structure among roots, genotypes and substrates. A framework model is formulated showing the influence of growth pattern and vascular structure on branching density. The model raises a distinction between growth components which should not affect the branching density (i.e. rate of cell division) and which may affect it (i.e. size of mature cells and number of transverse divisions performed by cells executing their trajectory in the meristem). It appears also that lateral root density and root growth rate might be independently modulated by appropriate changes of root growth patterns, in banana and presumably many other taxa.

Field of study: Environmental science
The enzymic conversion of linoleic acid into 9-(nona-1',3'-dienoxy)non-8-enoic acid, a novel unsaturated ether derivative isolated from homogenates of Solanum tuberosum tubers.

1. A major component of the lipids in aqueous (pH7.5) homogenates of tuber tissue from Solanum tuberosum was isolated and characterized as 9-(nona-1',3'-dienoxy)non-8-enoic acid. 2. This novel unsaturated ether fatty acid derivative, which contains a butadienylvinyl ether function, has the structure:  see text] and is formed from linoleic acid by a sequence of enzymic reactions. 3. A precursor of the unsaturated ether derivative is 9-d-hydroperoxyoctadeca-10,12-dienoic acid, formed by the action of S. tuberosum lipoxygenase on linoleic acid. 4. An enzyme that converts the fatty acid hydroperoxide into the unsaturated ether derivative was isolated from S. tuberosum. The pH optimum of this enzyme is approx. 9, although the overall conversion of linoleic acid into the ether derivative is maximal at pH7.5. 5. An unusual feature of this pathway is the insertion of an oxygen atom into the alkyl chain of a fatty acid. 6. This novel mechanism may play a role in the breakdown of polyunsaturated fatty acids to volatile products in plants.

Field of study: Biology, Computer science
Superoscillations With Optimum Energy Concentration

Oscillations of a bandlimited signal at a rate faster than the bandlimit are called “superoscillations” and have applications e.g. in superresolution and superdirectivity. The synthesis of superoscillating signals is a numerically difficult problem. Minimum energy superoscillatory signals seem attractive for applications because (i) the minimum-energy solution is unique (ii) it has the smallest energy cost (iii) it may yield a signal of the smallest possible amplitude. On the negative side, superoscillating functions of minimum-energy depend heavily on cancellation and give rise to expressions that have very large coefficients. Furthermore, these coefficients have to be found by solving equations that are very ill-conditioned. Surprisingly, we show that by dropping the minimum energy requirement practicality can be gained rather than lost. We give a method of constructing superoscillating signals that leads to coefficients and condition numbers that are smaller by several orders of magnitude than the minimum-energy solution, yet yields energies close to the minimum. In contrast with the minimum-energy method, which builds superoscillations by linearly combining functions with an ill-conditioned Gram matrix, our method combines orthonormal functions, the Gram matrix of which is obviously the identity. Another feature of the method is that it yields the superoscillatory signal that maximises the energy concentration in a given set, which may or may not include the superoscillatory segment.

Field of study: Engineering
Overexpression of bacterial catalase in tomato leaf chloroplasts enhances photo‐oxidative stress tolerance

The Escherichia coli gene katE, which is driven by the promoter of the Rubisco small subunit gene of tomato, rbcS3C, was introduced into a tomato ( Lycopersicon esculentum Mill.) by Agrobacterium tumefaciens -mediated transformation. Catalase activity in progeny from transgenic plants was approximately three-fold higher than that in wild-type plants. Leaf discs from transgenic plants remained green at 24 h after treatment with 1 µ M paraquat under moderate light intensity, whereas leaf discs from wild-type plants showed severe bleaching after the same treatment. Moreover, ion leakage from transgenic leaf discs was significantly less than that from wild-type leaf discs at 24 h after treatment with 1 µ M paraquat and 10 m M H 2 O 2 , respectively, under moderate light intensity. To evaluate the efficiency of the E. coli catalase to protect the whole transgenic plant from the oxidative stress, transgenic and wildtype plants were sprayed with 100 µ µ µ M paraquat and exposed to high light illumination (800 µ mol m − 2 s − 1 ). After 24 h, the leaves of the transgenic plants were less damaged than the leaves of the wild-type plants. The catalase activity and the photosynthesis activity (indicated by the F v / F m ratio) were less affected by paraquat treatment in leaves of transgenic plants, whereas the activities of the chloroplastic ascorbate peroxidase isoenzymes and the ascorbate content decreased in both lines. In addition, the transgenic plants showed increased tolerance to the oxidative damage (decrease of the CO 2 fixation and photosystem II activity and increase of the lipid peroxidation) caused by drought stress or chilling stress (4 ° C) under high light intensity (1000 µ mol m − 2 s − − − 1 ). These results indicate that the expression of the catalase in chloroplasts has a positive effect on the protection of the transgenic plants from the photooxidative stress invoked by paraquat treatment, drought stress and chilling stress.

Field of study: Environmental science