nils-herrmann/clean_scirepeval huggingface dataset:
The WFC3 Galactic Bulge Treasury Program: Metallicity Estimates for the Stellar Population and Exoplanet Hosts

We present new UV-to-IR stellar photometry of four low-extinction windows in the Galactic bulge, obtained with the Wide Field Camera 3 on the Hubble Space Telescope (HST). Using our five bandpasses, we have defined reddening-free photometric indices sensitive to stellar effective temperature and metallicity. We find that the bulge populations resemble those formed via classical dissipative collapse: each field is dominated by an old (~10 Gyr) population exhibiting a wide metallicity range (–1.5 [Fe/H] 0.5). We detect a metallicity gradient in the bulge population, with the fraction of stars at super-solar metallicities dropping from 41% to 35% over distances from the Galactic center ranging from 0.3 to 1.2 kpc. One field includes candidate exoplanet hosts discovered in the SWEEPS HST transit survey. Our measurements for 11 of these hosts demonstrate that exoplanets in the distinct bulge environment are preferentially found around high-metallicity stars, as in the solar neighborhood, supporting the view that planets form more readily in metal-rich environments.

Field of study: Physics
Noncooperative price taking in large dynamic markets

This chapter discusses noncooperative price taking in large dynamic markets. Cournot's proposition that large markets are competitive is reconciled with the possibility of equilibrium involving strategic interaction among firms. It is shown that, except when extraordinarily precise information is available, firms in a market with many agents are not visible enough for the equilibrium described by Stigler to be sustained. This result is proved by studying two formal representations of markets with many agents. One of these representations involves initially choosing a particular market, with finitely many participants, and then forming a sequence of increasingly large markets by adjoining at each stage a new copy of the original one. The result of this procedure is called a sequence of replica markets. All of the markets in the sequence have the same statistical characteristics, the ratio of firms to consumers is constant, and they all share the same competitive market-clearing prices. The other representation of markets with many agents exploits the fact that, if counting measure on the set of agents in a market is normalized to make the set into a probability space, then a description of agents' characteristics and actions is mathematically a random vector defined on the sample space of agents.

Field of study: Economics
Holocene and late Pleistocene slip rates on the San Andreas fault in Yucaipa, California, using displaced alluvial-fan deposits and soil chronology

We derived slip rates on the San Andreas fault from displacement of alluvial fans and from approximate dating of the fans by the degree of soil development. Distinctive red-purple sedimentary rocks of the Miocene(?) Potato Sandstone exposed on Yucaipa Ridge in the San Bernardino Mountains were transported down Wilson Creek and shed across the modern trace of the San Andreas fault. Soils developed in alluvial-fan deposits contain red-purple clasts of the Potato Sandstone and are progressively more developed toward the north-west as a result of fault displacement. We used soil development to estimate the ages of these alluvial fans and underlying deposits. Using dated soils from Cajon Pass and from the Central Valley of California, we estimated ages of Wilson Creek deposits, using a statistical method of maximum likelihood. These methods also utilize Monte Carlo simulations of larger data populations and account for soil variability, uncertainty of calibration dates, and the limited number of soils described and sampled. Resulting age estimates have considerable (as much as 80%) uncertainty, resulting largely from quality of calibration dates. Slip rates for three time intervals were obtained by restoring the medial axis of each displaced fan to Wilson Creek. Maximum slip rates were also obtained by restoring the westernmost extent of each fan to Wilson Creek. Best-estimate rates averaged to the present for 0 to 14,000 yr are 14 to 25 mm/yr; for 0 to 30,000 yr, 22 to 34 mm/yr, and for 0 to 65,000 or 90,000 yr, 12 to 16 mm/yr. Maximum rates averaged to present for 0 to 14,000 yr are as high as 65 mm/yr; older rates are as high as 80 mm/yr. When Holocene rates are accounted for, actual or incremental slip rates for the interval 30,000 to 65,000 or 90,000 yr B.P. are probably 6 to 13 mm/yr. These data tentatively suggest that slip rates on the modern trace have increased during the late Quaternary. Uncertainties in slip and age data, however, allow for rates to have been nearly constant or even decreasing toward the present.

Field of study: Geology
A study of the optical and polarisation properties of InGaN/GaN multiple quantum wells grown on a-plane and m-plane GaN substrates

We report on a comparative study of the low temperature emission and polarisation properties of InGaN/GaN quantum wells grown on nonpolar ( ) a-plane and ( ) m-plane free-standing bulk GaN substrates where the In content varied from 0.14 to 0.28 in the m-plane series and 0.08 to 0.21 for the a-plane series. The low temperature photoluminescence spectra from both sets of samples are broad with full width at half maximum height increasing from 81 to 330 meV as the In fraction increases. Photoluminescence excitation spectroscopy indicates that the recombination mainly involves strongly localised carriers. At 10 K the degree of linear polarisation of the a-plane samples is much smaller than of the m-plane counterparts and also varies across the spectrum. From polarisation-resolved photoluminescence excitation spectroscopy we measured the energy splitting between the lowest valence sub-bands to lie in the range of 23–54 meV for the a- and m-plane samples in which we could observe distinct exciton features. Thus the thermal occupation of a higher valence sub-band cannot be responsible for the reduction of the degree of linear polarisation at 10 K. Time-resolved spectroscopy indicates that in a-plane samples there is an extra emission component which is at least partly responsible for the reduction in the degree of linear polarisation.

Field of study: Physics
Influence of Silica as an Abrasive on Friction Performance of Polyimide-Matrix Composites

This study investigated the friction performance of polyimide-matrix composites with various silica powder contents of different sizes. The friction tests were performed on a pin-on-disk tester at various velocities, ranging from 30 to 160 km/h. The experimental results indicate a silica powder size of 0.25±0.05 mm, a sample of 4 wt.% SiO2 demonstrated a high friction coefficient and better wear performance as compared to a sample without silica. The influence of silica content and powder size on the friction coefficient is directly related to the friction velocity. At low friction velocity (30–90 km/h), the friction coefficient increases as the SiO2 content increases, but decreases with increasing SiO2 particle size. At high friction velocity (90–160 km/h), the content and particle size of SiO2 have little influence on the friction coefficient. Experimental results indicate that large SiO2 particles can effectively hinder the motion of third body, which is advantageous to the formation of a compact third body and to the protection of the friction surface.

Field of study: Materials science
Synthesis and Properties of New pH Sensitive Chitosan Fluorescent Nanoparticles

A new naphthalimide kind of carboxyl-containing fluorophore was synthesized,and then the fluorescent polymer naphthalimide-modified carboxymethyl chitosan(CMCS3N) was developed by the way of chemical bonding of the synthesized naphthalimide fluorophore into carboxymethyl chitosan(CMCS),a water-soluble polymer with good biocompatibility.The structures and morphology of CMCS3N have been characterized by the methods of infrared spectroscopy,ultraviolet-visible spectroscopy and transmission electron microscopy.The results showed that the fluorescent polymer has nanostructure with diameters of about 40 nm.The fluorescence microscopy images illustrated CMCS3N could give yellow-green fluorescence under UV-light.The excitation and emission wavelengths of the nanoparticles have been obtained by fluorescent spectroscopy with 409 nm and 534 nm,respectively.The fluorescence of CMCS3N was sensitive to pH in the range from pH 5 to 8 and 1.0×10-5 mol/L of common metal cations had no obvious effect on the fluorescence intensity.The results indicated CMCS3N could be used as pH sensitive fluorescent probes in vivo imaging.

Field of study: Chemistry
Kinetics of development and characteristics of antibodies induced in cancer patients against yeast expressed rDNA derived granulocyte macrophage colony stimulating factor (GM-CSF).

We have determined the presence and kinetics of granulocyte macrophage colony stimulating factor (GM-CSF) antibodies induced after repeated administration of a yeast expressed GM-CSF product in prostate cancer patients with minimal recurrent disease using a panel of assays for detection and characterization of antibodies. Results showed that all 15 prostate cancer patients treated with GM-CSF developed GM-CSF reactive antibodies during the course of therapy. Most patients (87%) developed GM-CSF reactive antibodies within 3 months while in other patients (13%), these antibodies were induced after additional cycles of GM-CSF treatment. For most patients, the timing of occurrence of these antibodies was the same regardless of whether the ELISA or surface plasmon resonance (SPR) assays were used for detection. However, in two patients, the recognition of GM-CSF reactive antibodies by SPR assays preceded their detection by ELISA. A significant number of patients (n=9, 60%) developed GM-CSF antibodies which neutralized the biological activity of GM-CSF in vitro in a cell-line based bioassay. These antibodies also recognized GM-CSF protein from different expression systems including the non-glycosylated protein from E. coli indicating that the antibody response is directed towards the amino acid backbone of the protein. A significant effect of GM-CSF antibodies on PSA modulation was not observed in this small cohort of patients despite an alteration in PSA levels in some treated patients. The study design used here did not allow conclusions regarding the relationship between neutralizing antibodies and the PSA levels which were used as a marker for clinical outcome. Implementation of a clinical strategy which permits monitoring for antibody development and for levels of a relevant pre-determined clinical marker at appropriate time-points is necessary for assessing the impact of antibody development on the therapeutic efficacy of the protein.

Field of study: Medicine
Robust Adaptive Beamforming Based on Low-Rank and Cross-Correlation Techniques

This paper presents cost-effective low-rank techniques for designing robust adaptive beamforming (RAB) algorithms. The proposed algorithms are based on the exploitation of the cross-correlation between the array observation data and the output of the beamformer. First, we construct a general linear equation considered in large dimensions whose solution yields the steering vector mismatch. Then, we employ the idea of the full orthogonalization method (FOM), an orthogonal Krylov subspace based method, to iteratively estimate the steering vector mismatch in a reduced-dimensional subspace, resulting in the proposed orthogonal Krylov subspace projection mismatch estimation (OKSPME) method. We also devise adaptive algorithms based on stochastic gradient (SG) and conjugate gradient (CG) techniques to update the beamforming weights with low complexity and avoid any costly matrix inversion. The main advantages of the proposed low-rank and mismatch estimation techniques are their cost-effectiveness when dealing with high-dimension subspaces or large sensor arrays. Simulations results show excellent performance in terms of the output signal-to-interference-plus-noise ratio (SINR) of the beamformer among all the compared RAB methods.

Field of study: Engineering
The Use of Eutectic Fe-Si-B Alloy as a Phase Change Material in Thermal Energy Storage Systems

Fe-26.38Si-9.35B eutectic alloy is proposed as a phase change material (PCM) as it exhibits high latent heat, high thermal conductivity, moderate melting point, and low cost. For successful implementation of it in the latent heat thermal energy storage (LHTES) systems, we investigate the use of graphite as a refractory material that withstands long-term melting/solidification in contact with the Fe-26.38Si-9.35B alloy. The PCM has been thermally cycled up to 1–4 times below and above its melting point at the temperature interval of 20 °C or 100 °C. It is observed that this eutectic alloy shows good thermal stability over a small temperature range of 1057–1257 °C. Some SiC and B4C solid precipitation will be formed at the top of the alloy. However, it does not seem to increase with time. The graphite crucible as a refractory material will produce a protective layer of SiC and B4C that will hinder the interaction between the PCM and the crucible. The small volume change during solidification will not break the graphite crucible during cycling. The chemical wear or dissolution of the crucible is negligible. It demonstrates the viability of Fe-26.38Si-9.35B alloy as a heat storage material in this type of container.

Field of study: Materials science
Anti-aging effect of astragalosides and its mechanism of action.

To study the anti-aging effect of astragalosides (AST) and its mechanism of action.



Rotating rod test and step-down type passive avoidance test were performed to determine the effects of AST on motor and memory of D-galactose (D-gal)-induced senescent mice and the middle-aged mice. The proliferative response of splenocytes induced by Con A or LPS, IL-2 production of splenocytes induced by ConA of D-gal-treated mice and the middle-aged mice were also measured.



AST (40 mg.kg(-1).d(-1), ig, for 10 weeks) was found to ameliorate age-related alternations in both motor response and memory, enhance the deteriorated cellular immunity in D-gal-treated mice and the pre-aged (17-month-old) mice.



AST has an anti-aging effect on D-gal-induced senescent mice and has the effect of delaying senility of the middle-aged mice, which was related to its improvement of brain function and immunomodulatory effects.

Field of study: Biology, Chemistry, Medicine
Potential use of a monoclonal antibody for the detection of Candida antigens in an experimental systemic candidiasis model.

The Candida species are the most common fungal pathogens of systemic candidiasis. The diagnosis of invasive candidiasis remains a laboratory and clinical challenge. Thus, development of diagnostic assays to detect systemic candidiasis and to identify Candida virulence factors and associated pathogenesis through immunohistochemistry using specific monoclonals and polyclonals will be useful. Inbred Balb/c mice were immunized with C. albicans antigens, and blood was checked for the presence of reactive antibodies using ELISA. Fusion was performed using the harvested spleen cells and NS1 myeloma cells, and the clones were screened for the presence of antibody producing hybrid cells by dot-blot. Western blot analysis showed that the L2D10 monoclonal antibody was reactive against the antigens with molecular weight of 20 kDa. Experimental systemic candidiasis in mice was induced through intravenous injection of C. albicans and all the vital organs were collected for immunohistochemistry study. The monoclonal antibody reacted to surface epitopes on the yeast cells, germ tubes, and hyphae, and to immune complexes. It was used with the polyclonal antibody in a sandwich ELISA for the detection of circulating antigens in experimental candiadiasis in mice. Antibody levels were also determined using the ELISA method, and the antibody levels of C. albicans infected mice were increased compared with uninfected animals. The monoclonal antibody was used in immunoperoxidase and immunofluorescence techniques for the detection of fungal infection in tissue sections and was found to be more sensitive than conventional periodic acid Schiff or silver staining techniques. This monoclonal antibody may serve as potential primary capture antibodies for the development of a rapid diagnostic test for human systemic fungal infection.

Field of study: Biology
Research on the Robustness of Face Gabor Wavelet Features

Face recognition can be summed up as features of the extract,for identification tasks,the most important thing is to be extracted to identify the characteristics of the image,but it is very difficult to extract the image identify characteristics.Researches on facial image in a different light,the position under the conditions of the Gabor wavelet characteristics,proves that the robustness of Gabor wavelet characteristics in the face recognition.

Field of study: Computer science
Complex Reflection Groups and Fake Degrees

In this paper we study the Hecke algebra associated with a complex reflection group W. We discuss some properties of the Galois group of the splitting field of this algebra, and study its action on the so-called fake degrees of W. The methods we use to study the Hecke algebra are based on the construction of representations of this algebra as monodromy of equations of Knizhnik-Zamolodchikov type.

Field of study: Mathematics
Sensitive spin detection using an on-chip SQUID-waveguide resonator

Precise detection of spin resonance is of paramount importance to achieve coherent spin control in quantum computing. We present a setup for spin resonance measurements, which uses a dc-SQUID flux detector coupled to an antenna from a coplanar waveguide. The SQUID and the waveguide are fabricated from a 20 nm Nb thin film, allowing high magnetic field operation with the field applied parallel to the chip. We observe a resonance signal between the first and third excited states of Gd spins S = 7/2 in a CaWO4 crystal, relevant for state control in multi-level systems.

Field of study: Physics
Transducer for Direct Measurement of Skin Friction in Hypervelocity Impulse Facilities

An acceleration compensated transducer was developed to enable the direct measurement of skin friction in hypervelocity impulse facilities. The gauge incorporated a measurement and acceleration element that employed direct shear of a piezoelectric ceramic. The design integrated techniques to maximize rise time and shear response while minimizing the affects of acceleration, pressure, heat transfer, and electrical interference. The arrangement resulted in a transducer natural frequency near 40 kHz. The transducer was calibrated for shear and acceleration in separate bench tests and was calibrated for pressure within an impulse facility. Uncertainty analyses identified only small experimental errors in the shear and acceleration calibration techniques. Although significant errors were revealed in the method of pressure calibration, total skin-friction measurement errors as low as +/-7-12% were established. The transducer was successfully utilized in a shock tunnel, and sample measurements are presented for flow conditions that simulate a flight Mach number near 8.

Field of study: Physics
Unraveling heavy oil desulfurization chemistry: targeting clean fuels.

The sulfur removal chemistry of heavy oils has been unraveled by systematically investigating several heavy oils with an extremely wide range of properties. The heavy oil feed and product properties have been characterized by advanced analytical methods, and these properties have been related to the sulfur conversion data observed in pilot hydrotreating units. These studies coupled with kinetic treatment of the data have revealed that the desulfurization chemistry of heavy oils is essentially controlled by the strongly inhibiting three and larger ring aromatic hydrocarbon content and surprisingly not by the content of the "hard-to-remove" sulfur compounds. Such enhanced understanding of the heavy oil sulfur removal is expected to open new avenues for catalyst/process optimization for heavy oil desulfurization and thereby assist the efficent production of clean transporation fuels.

Field of study: Environmental science
Structures of the DNA-binding site of Runt-domain transcription regulators.

Runt-domain (RD) proteins are transcription factors that play fundamental roles in various developmental pathways. They bind specifically to DNA sequences of the general form PyGPyGGTPy (Py = pyrimidine), through which they regulate transcription of target genes. The DNA duplex TCTGCGGTC/TGACCGCAG, incorporating the binding site for the RD transcription factors (bold), was crystallized in space group P4(3). X-ray analysis of two crystals diffracting to 1.7 and 2.0 angstroms resolution, which had slight variations in their unit-cell parameters, revealed two distinct conformations of the A-DNA helix. The two crystal structures possessed several structure and hydration features that had previously been observed in A-DNA duplexes. A comparative analysis of the present A-DNA structures and those of previously reported B-DNA crystal structures of RD-binding sites in free and protein-bound states showed the various duplexes to display several common features. Within this series, the present A-DNA duplexes adopt two conformations along the pathway from the canonical A-DNA to the B-DNA forms and the protein-bound helices display conformational features that are intermediate between those of the current A-DNA structures and that of the B-DNA-type helix of the free RD target. Based on these data and energy considerations, it is likely that the propensity of the RD-binding site to adopt the A-DNA or B-DNA conformation in solution depends on the sequence context and environmental conditions, and that the transition from either DNA form to the protein-bound conformation involves a small energy barrier.

Field of study: Chemistry
Use of iron anomalous scattering with multiple models and data sets to identify and refine a weak molecular replacement solution: structure analysis of cytochrome c' from two bacterial species.

The structure of cytochrome c' from two bacterial species, Alcaligenes sp and Alcaligenes denitrificans, have been determined from X-ray diffraction data to 3.0 A resolution using the anomalous scattering of the single Fe atom in each to identify and refine a weak molecular-replacement solution. Molecular-replacement studies, with the program AMORE, used two isomorphous data sets (from the two species), two independent search models (the cytochromes c' from Rhodospirillum molischianum and Rhodospirillum rubrum), both with and without side chains, and two different resolution ranges (10.0-4.0 and 15.0-3.5A) to generate a large number of potential solutions. No single solution stood out and none appeared consistently. The Fe-atom position in each structure was then determined from its anomalous-scattering contribution and all molecular- replacement solutions were discarded which did not (i) place the Fe atom correctly and (ii) orient the molecule such that a crystallographic twofold axis generated a dimer like those of the two search models. Finally, electron-density maps phased solely by the Fe-atom anomalous scattering were calculated. As these were combined and subjected to solvent flattening and histogram matching (with the program SQUASH), correlation with the remaining molecular-replacement solutions identified one as correct and enabled it to be improved and subjected to preliminary refinement. The correctness of the solution is confirmed by parallel isomorphous-replacement studies.

Field of study: Chemistry