nils-herrmann/clean_scirepeval huggingface dataset:
Characterization of a phosphotriesterase from genetically-engineered Escherichia coli.

A phosphotriesterase (PTE) capable of hydrolyzing organophosphate esters was purified from Escherichia coli strain DH-5 alpha carrying a cloned opd gene from Flavobacterium. The effects of pH, temperature and metal ion concentrations on enzyme stability and activity were investigated. Optimum conditions for PTE's catalytic activity were determined to be 35 degrees C and pH 8.5. Protein-metal equilibrium binding experiments showed that PTE could accommodate two equivalents of Co2+ or Zn2+ ions. PTE protein was found to have higher affinity for Co2+. In addition, Co2+ was found to possess the most positive effects in maintaining and restoring PTE's stability and catalytic activity when compared to other divalent metal ions. Assessment of the feasibility of PTE operation in a practical environment was performed in a system designed to mimic a continuously stirred tank reactor (CSTR) with different solution compositions in the flow reservoir. PTE was deactivated in 24 hours when the inflow solution contained 5% ethanol or 1 mM EDTA, while it retained one third of its initial activity in a deionized water stream. When the inflow solution contained 1 mM Co2+, PTE was found to retain activity throughout the 24-hour experiment.

Field of study: Agricultural and Food sciences
Active evolution and current molecular learning.

It is sometimes said that one cannot have intermediary forms of organs or tissues in evolution that are useful, despite a great deal of data to show that this is simply not true (the eye, the subject of a previous Biologic, was formed in about 400 000 years1). Richard Dawkins has often written about the difficulties that creationists and others (he singles out lawyers as a group that believe in discontinuities rather than continuous variation) have with the absence of intermediate forms, perhaps because of a view of evolutionary action that is ‘progress driven’. But continuous variation is obvious, and runs from us through Homo erectus and Homo habilis , and so on. In evaluating this, we have looked at how the molecular clock runs in evolution in this series and discussed the point that while most mutations are neutral in genetic effect (and some are harmful), often phenotypic change over time does not depend on structural change in the genome—changes in gene expression may be more significant. So while it would be satisfying to be able to see continuous variation leading to phenotypic change, it is not often that one can study evolution as it happens. More observations of this kind are …

Field of study: Medicine
Environmental and energy implications of plug-in hybrid-electric vehicles.

We analyze the effect of charging a significant number of plug-in hybrid vehicles (PHEVs) in the United States using presently available night-time spare electric capacity in the shortterm and new base-load capacity in the long term. Nationwide, there is currently ample spare night-time utility capacityto charge even a large fleet of PHEVs. Using the mix of generating plants expected to be used for PHEV charging, we find that, while driving on battery power, PHEVs compared to their conventional hybrid counterparts reduce CO2 emissions by 25% in the short term and as much as 50% in the long term. The shortterm fractional increase in demand for margin fuels such as natural gas is found to be roughly twice the fractional penetration of PHEVs into the nationwide light-duty vehicle fleet. We also compare, on an energy basis, the CO2 savings of replacing coal plants versus replacing conventional vehicles with PHEVs. The result is found to depend critically on the fuel economy of the vehicles displaced by the PHEVs.

Field of study: Environmental science
Study on the Property of HSYV-5e 4×2×0.5 Cable Preparation with Copper Single Crystal

Copper single crystal wire (diameter is 2.7 mm) was produced by self-made single crystal zone melting machine, cold-drawed into diameter of 0.51mm, produced into HSYV-5e 4×2×0.5 solid horizontal twisted cable according to YD /T 1019-2001. The electrical performance of copper single crystal wire and ordinary oxygen-free copper wire have been detected . The results indicated that the DC resistive of copper single crystal wire is decreased by 4.59 percent when comparing with that of ordinary oxygen-free copper, and an obviously improvement on signal damping can be observed; moreover deformation twins and grain boundary are the main characteristic of microstructure of copper single crystal wire after cold-drawing.

Field of study: Materials science
Combinatorics of RNA–RNA interaction

RNA–RNA binding is an important phenomenon observed for many classes of non-coding RNAs and plays a crucial role in a number of regulatory processes. Recently several MFE folding algorithms for predicting the joint structure of two interacting RNA molecules have been proposed. Here joint structure means that in a diagram representation the intramolecular bonds of each partner are pseudoknot-free, that the intermolecular binding pairs are noncrossing, and that there is no so-called “zigzag” configuration. This paper presents the combinatorics of RNA interaction structures including their generating function, singularity analysis as well as explicit recurrence relations. In particular, our results imply simple asymptotic formulas for the number of joint structures.

Field of study: Biology, Mathematics
Luminescence and Thermal-Quenching Properties of Red-Emitting Ca2Al2SiO7:Sm3+ Phosphors

Ca2Al2SiO7:x.Sm3+ (x = 0.5, 1.0, 1.5, 2.0, 2.5, and 3.5 mol.%) (CAS:x.Sm3+) phosphors were synthesized by a solid-state reaction technique. The structure, photoluminescence properties and thermal stability of phosphors were investigated in detail. Results of X-ray diffraction show that CAS:x.Sm3+ materials have a single-phased tetragonal structure, and an expansion of the unit cell relates to the increasing of Sm3+ concentration. Photoluminescence study displayed that the CAS:x.Sm3+ phosphors reach the highest emission intensity at 1.5 mol.% Sm3+ and achieved the luminescence quenching phenomenon a higher concentration. The dominant interaction mechanism of the concentration quenching process is determined due to the dipole–dipole interaction, and the critical transfer distance (Rc) is 26.7 Å. The temperature dependence of photoluminescence spectra indicates that the Ca2Al2SiO7:Sm3+ (1.5 mol.%) phosphor possess good thermal stability, and that the activation energy is around 0.12 eV (968 cm−1). Several characteristic vibrations in the 200–1000-cm−1 region were observed by Raman spectra, and the color chromaticity coordinates of the samples were also calculated and discussed.

Field of study: Materials science
Performance of extrapolation based on Pitman's measure of closeness in spatial regression models with extended skew t innovations

Pitman's measure of closeness and mean square error of prediction are two well-known criteria for comparison between estimators and also between predictors. In a stationary first order multiplicative spatial autoregressive model, interpolation and extrapolation are compared based on these two criteria. A wide class of different innovation types are also studied containing Gaussian, exponential, asymmetric Laplace and extended skew t distributions.

Field of study: Mathematics
Boredom Proneness in Pathological Gambling

To test the hypothesis that pathological gamblers seek stimulation as a means of reducing aversive underaroused states of boredom and/or depression, the Beck Depression Inventory, Zuckerman's Sensation Seeking Scale and a Boredom Proneness Scale were administered to 48 diagnosed pathological gamblers and a control group of 40 family physician patients. Analyses of variance showed pathological gamblers obtained significantly higher boredom proneness and depression scores than those of controls. That the Boredom Proneness Scale failed to correlate with the Zuckerman Boredom Susceptibility subscale suggested the two measure differing dimensions. Results indicated the possible existence of three subtypes of pathological gamblers, one group characterized by boredom, another by depression, and a third by a mixture of both depression and boredom.

Field of study: Psychology
Determination of metal-metal distances: significance and accuracy.

Nature utilises a variety of metal clusters as catalytic centers. Some of them make use of two or more metals in the catalytic site. The variation of metal-metal distances plays an important role in several processes like charge transfer and weakening of bonds. X-ray absorption spectroscopy can determine these metal-metal distances in several states (crystal, solution or amorphous). However sometimes backscattering from light elements hides the metal-metal contribution to the fine structure. Here we point out significance and accuracy of metal-metal distances in a model system. Therefore a number of different refinement protocols are applied to the data. These protocols will be discussed focusing on the significance and accuracy of the metal-metal distances extracted from the data.

Field of study: Physics
Bacterioplankton community diversity in a maritime Antarctic lake, determined by culture-dependent and culture-independent techniques.

The biodiversity of the pelagic bacterioplankton community of a maritime Antarctic freshwater lake was examined by cultivation-dependent and cultivation-independent techniques to determine predominant bacterioplankton populations present. The culture-dependent techniques used were direct culture and observation, polymerase chain reaction amplification of 16S rRNA gene fragments, restriction fragment length polymorphism (RFLP) analysis followed by selective sequencing and fatty acid methyl ester analysis. The culture-independent techniques used were 16S ribosomal DNA gene cloning, RFLP analysis and sequencing, in situ hybridisation with group-specific, fluorescently labelled oligonucleotide probes and cloning and sequencing of dominant denaturing gradient gel electrophoresis products. Significant differences occurred between the results obtained with each method. However, sufficient overlap existed between the different methods to identify potentially significant groups. At least six different bacterial divisions including 24 genera were identified using culture-dependent techniques, and eight different bacterial divisions, including 23 genera, were identified using culture-independent techniques. Only five genera, Corynebacterium, Cytophaga, Flavobacterium, Janthinobacterium and Pseudomonas, could be identified using both sets of techniques, which represented four different bacterial divisions. Significantly for Antarctic freshwater lakes, pigment production is found within members of each of these genera. This work illustrates the importance of a comprehensive polyphasic approach in the analysis of lake bacterioplankton, and supports the ecological relevance of results obtained in earlier entirely culture-based studies.

Field of study: Biology, Environmental science
THE EFFECT OF PERCEIVED ORGANIZATIONAL SUPPORT AND CREATIVE SELF EFFICACY ON CREATIVE WORK INVOLVEMENT

Organizational Creativity has become a relatively new and emerging research area within the field of organizational behavior. This study intends to investigate the predictors of creative work involvement through the perception of employees about organizational support and creative self efficacy. The research is conducted by 129 participants from different sectors through survey method. Empirical findings reveal that creative self efficacy and perceived organizational support affect creative work involvement positively and significantly. Depending on the fact that it is a study conducted in Turkey, it may also serve the purpose of providing a cultural perspective for international studies on organizational creativity. It also intends to provide further contribution to the business literature by pointing out managerial implications of the research concepts, and the relationships among them

Field of study: Business
Code Design to Optimize Radar Detection Performance Under Accuracy and Similarity Constraints

This paper deals with the design of coded waveforms which optimize radar performances in the presence of colored Gaussian disturbance. We focus on the class of linearly coded pulse trains and determine the optimum radar code according to the following criterion: maximization of the detection performance under a control on the region of achievable Doppler estimation accuracies, and imposing a similarity constraint with a prefixed radar code. This last constraint is tantamount to requiring a similarity between the ambiguity functions of the devised waveform and of the pulse train encoded with the prefixed sequence. The resulting optimization problem is nonconvex and quadratic. In order to solve it, we propose a technique (with polynomial computational complexity) based on the relaxation of the original problem into a semidefinite program. Thus, the best code is determined through a rank-one decomposition of an optimal solution of the relaxed problem. At the analysis stage, we assess the performance of the new encoding technique in terms of detection performance, region of achievable Doppler estimation accuracies, and ambiguity function.

Field of study: Engineering
Translational Control in Stem Cells

Simultaneous measurements of mRNA and protein abundance and turnover in mammalian cells, have revealed that a significant portion of the cellular proteome is controlled by mRNA translation. Recent studies have demonstrated that both embryonic and somatic stem cells are dependent on low translation rates to maintain an undifferentiated state. Conversely, differentiation requires increased protein synthesis and failure to do so prevents differentiation. Notably, the low translation in stem cell populations is independent of the cell cycle, indicating that stem cells use unique strategies to decouple these fundamental cellular processes. In this chapter, we discuss different mechanisms used by stem cells to control translation, as well as the developmental consequences of translational deregulation.

Field of study: Biology
First image of the L1157 molecular jet by the CALYPSO IRAM-PdBI survey

Fast jets are thought to be a crucial ingredient of star formation because they might extract angular momentum from the disk and thus allow mass accretion onto the star. However, it is unclear whether jets are ubiquitous, and likewise, their contribution to mass and angular momentum extraction during protostar formation remains an open question.  Our aim is to investigate the ejection process in the low-mass Class 0 protostar L1157. This source is associated with a spectacular bipolar outflow, and the recent detection of high-velocity SiO suggests the occurrence of a jet.  Observations of CO 2 −1 and SiO 5 − 4 at ~ \hbox{$0\farcs8$} resolution were obtained with the IRAM Plateau de Bure Interferometer (PdBI) as part of the CALYPSO large program. The jet and outflow structure were fit with a precession model. We derived the column density of CO and SiO, as well as the jet mass-loss rate and mechanical luminosity.  High-velocity CO and SiO emission resolve for the first time the first 200 au of the outflow-driving molecular jet. The jet is strongly asymmetric, with the blue lobe ~0.65 times slower than the red lobe. This suggests that the large-scale asymmetry of the outflow is directly linked to the jet velocity and that the asymmetry in the launching mechanism has been at work for the past 1800 yr. Velocity asymmetries are common in T Tauri stars, which suggests that the jet formation mechanism from Class 0 to Class II stages might be similar. Our model simultaneously fits the properties of the inner jet and of the clumpy 0.2 pc scale outflow by assuming that the jet precesses counter-clockwise on a cone inclined by 73° to the line of sight with an opening angle of 8° on a period of ~1640 yr. The estimated jet mass flux and mechanical luminosity are Ṁ jet ~ 7.7 × 10 -7 M ⊙ yr -1 and L jet ~ 0.9 L ⊙ , indicating that the jet could extract at least 25% of the gravitational energy released by the forming star.

Field of study: Physics
Implementing Web Pages Search using Google Web API

With the development of Internet, the function of Web pages search is being more and more important. The development of Application Programming Interfa ce technology which is based on Web services technology, makes it possible to develop the applying soft ware of Web pages search. This paper introduces a method to implement Web pages search using Google Web AP I, gives a part of detailed list of the program which is implemented using VB .NET language, and makes comment on the program.

Field of study: Computer science
A structural view of the dissociation of Escherichia coli tryptophanase.

Tryptophanase (Trpase) is a pyridoxal 5'-phosphate (PLP)-dependent homotetrameric enzyme which catalyzes the degradation of L-tryptophan. Trpase is also known for its cold lability, which is a reversible loss of activity at low temperature (2°C) that is associated with the dissociation of the tetramer. Escherichia coli Trpase dissociates into dimers, while Proteus vulgaris Trpase dissociates into monomers. As such, this enzyme is an appropriate model to study the protein-protein interactions and quaternary structure of proteins. The aim of the present study was to understand the differences in the mode of dissociation between the E. coli and P. vulgaris Trpases. In particular, the effect of mutations along the molecular axes of homotetrameric Trpase on its dissociation was studied. To answer this question, two groups of mutants of the E. coli enzyme were created to resemble the amino-acid sequence of P. vulgaris Trpase. In one group, residues 15 and 59 that are located along the molecular axis R (also termed the noncatalytic axis) were mutated. The second group included a mutation at position 298, located along the molecular axis Q (also termed the catalytic axis). Replacing amino-acid residues along the R axis resulted in dissociation of the tetramers into monomers, similar to the P. vulgaris Trpase, while replacing amino-acid residues along the Q axis resulted in dissociation into dimers only. The crystal structure of the V59M mutant of E. coli Trpase was also determined in its apo form and was found to be similar to that of the wild type. This study suggests that in E. coli Trpase hydrophobic interactions along the R axis hold the two monomers together more strongly, preventing the dissociation of the dimers into monomers. Mutation of position 298 along the Q axis to a charged residue resulted in tetramers that are less susceptible to dissociation. Thus, the results indicate that dissociation of E. coli Trpase into dimers occurs along the molecular Q axis.

Field of study: Chemistry
The Export Competitiveness of Electromechanical Products between Fujian and ASEAN Countries

Along with the formal establishment of CAFTA,the regional economic and trade cooperation has entered into a new stage.Electromechanical industry is a chief one in the trade between Fujian and ASEAN countries.However,comparing Fujian's export of mechanical and electrical products with ASEAN's,we can find that there is more competitiveness than complementarity.The amount of export and international market share of Fujian increases year by year,the growth is faster,and the products are more competitive in general.However,there still exists a gap compared to Singapore and the Philippines.Fujian should give full play to its strengths and avoid its weaknesses by attaching importance to adjusting and upgrading industrial structure,increasing scientific research input,promoting research and development ability,increasing the technological element of its products,taking trans-regional industrial agglomeration,implementing the strategy of"going out"and increasing investment in ASEAN countries,so as to promote the export competitiveness of its mechanical and electrical products.

Field of study: Agricultural and Food sciences
Covariate Regularized Community Detection in Sparse Graphs

In this article, we investigate community detection in networks in the presence of node covariates. In many instances, covariates and networks individually only give a partial view of the cluster structure. One needs to jointly infer the full cluster structure by considering both. In statistics, an emerging body of work has been focused on combining information from both the edges in the network and the node covariates to infer community memberships. However, so far the theoretical guarantees have been established in the dense regime, where the network can lead to perfect clustering under a broad parameter regime, and hence the role of covariates is often not clear. In this article, we examine sparse networks in conjunction with finite dimensional sub-Gaussian mixtures as covariates under moderate separation conditions. In this setting each individual source can only cluster a nonvanishing fraction of nodes correctly. We propose a simple optimization framework which improves clustering accuracy when the two sources carry partial information about the cluster memberships, and hence perform poorly on their own. Our optimization problem can be solved by scalable convex optimization algorithms. With a variety of simulated and real data examples, we show that the proposed method outperforms other existing methodology.

Field of study: Mathematics
Lynching in the West: 1850-1935 (review)

In this intriguing new study, Ken Gonzales-Day attempts to demonstrate that scholars of lynching have focused too narrowly on African American victims in the South. His book shows that lynching accounted for the deaths of more than 350 people in California between 1850 and 1935. The author accounts for this phenomenon by placing his emphasis on the primacy of racism. Most of those who died as a result of hanging or summary execution were members of racial minorities including African Americans, Native Americans, Chinese, and, above all, persons of Mexican origin or descent. The strength of this argument is underlined through the inclusion of an inventory of lynching victims at the end of the book.

Field of study: History
Urocortin 1 and 3 impair maternal defense behavior in mice.

Lactating female mice fiercely defend offspring while exhibiting decreased fear and anxiety. Recent work (J. S. Lonstein & S. C. Gammie, 2002) found that intracerebroventricular (icv) injections of corticotropin releasing factor (CRF), a putative anxiogenic peptide, inhibit maternal defense behavior. This study examines effects of CRF-related peptides, urocortin (Ucn) 1 and Ucn 3, on maternal aggression in mice. Intracerebroventricular injections of both Ucn 1 (0.2 microg) and Ucn 3 (0.5 microg) reduced aggression but not pup retrieval. c-Fos levels were elevated by intracerebroventricular injections of Ucn 1 (0.2 microg) and Ucn 3 (0.5 microg) in 2 and 6 brain regions, respectively; however, both triggered increases in bed nucleus of the stria terminalis dorsal (BNSTd) and lateral septum (LS). These findings suggest that CRF-related peptides similarly modulate maternal aggression and that BNSTd/LS may be critical sites for negative regulation of maternal aggression.

Field of study: Biology, Psychology
John Pendleton and His Friendship with Urquiza

The able and distinguished envoy, whose penetrating observations were destined to cover two-and-a-half dramatic years in Argentine history, was well equipped at forty-nine years of age with human qualities and the worldly experience to represent his country abroad with success. He was a leading member of the Whig party in Virginia. Descended from an old and long-prominent family of his state, Pendleton has served several terms in the Virginia House of Delegates; had been charge d'affaires in Chile; and had been elected twice to the Federal Congress.4 He possessed an attractive person-

Field of study: History