nils-herrmann/clean_scirepeval huggingface dataset:
The role of impurity band conduction in the low temperature characteristics of thin InSb films grown by molecular beam epitaxy

We report on the temperature-dependent electrical properties of high-quality undoped InSb layers of various thicknesses grown on GaAs(100) substrates by molecular beam epitaxy. The layers are found to be n-type in the measured temperature range (77-297 K). A differential Hall approach was employed to characterize the depth dependence of the electrical properties of the InSb films. The temperature variations of these data were then modelled with the inclusion of conduction through an impurity band, formed by the overlap of the wavefunctions of the dislocation-related donors. These analyses suggest that the contribution of the impurity band is dominant close to the interface even at room temperature, but its effect falls with increasing thickness, until at similar to 1000 nm, its contribution is only comparable to that of the conduction band at low temperatures. The dislocation donor densities deduced from this modelling follow an approximately reciprocal trend with increasing distance from the interface.

Field of study: Materials science
Extraordinary magnetoresistance of organic semiconductors : Hopping conductance via non-zero angular momentum orbitals

Highly-anisotropic in-plane magneto-resistance (MR) in graphite (HOPG) samples has been recently observed (Y. Kopelevich et al., ) which is negative and linear in low fields in some current direction while it is giant, super-linear and positive in the perpendicular direction. In the framework of the hopping conductance theory via non-zero angular momentum orbitals we link extraordinary MRs in graphite and in organic insulators (OMAR) observed in about the same magnetic fields. The theory predicts quadratic negative MR (NMR) when there is a time-reversal symmetry (TRS), and linear NMR if TRS is broken. We argue that the observed linear NMR could be a unique signature of the broken TRS both in graphite and organic compounds. While some local paramagnetic centers are responsible for the broken TRS in organic insulators, a large diamagnetism of our HOPG samples may involve a more intriguing scenario of TRS breaking.

Field of study: Physics
Preliminary in vitro efficacy and toxicities studies of the herpes simplex thymidine kinase gene system for the treatment of breast cancer.

A novel gene therapy strategy is the use of suicide genes that transfer a drug sensitivity to cancer cells. We present preliminary in vitro efficacy data and in vivo toxicity data using the herpes simplex thymidine kinase (HStk) gene for breast cancer. The long-term objective of this project is to develop novel approaches for the treatment of breast cancer using in vivo retroviral gene transfer. Intraductal breast cancer cell line HTB126 transduced by an HStk retroviral vector is efficiently inhibited in vitro after GCV exposure. Further analysis revealed a bystander effect through which nontransduced HTB126 cells were also inhibited by GCV when cocultured with HStk-transduced HTB126 cells. In cell mixture experiments if only 1% of the cells in culture contained the HStk gene, 83% of the culture could be destroyed. Next safety studies were performed. Vector producer cells (VPC) were implanted into the mammary fat pads of athymic nude mice. The mice were then treated with GCV and monitored for regression of the VPC. The injected VPC regressed rapidly in response to the GCV therapy and produced no evidence of local or systemic toxicity in the animals. These in vitro efficacy data and in vivo toxicity studies lend support to the further development of an in vivo therapy model to treat breast cancer.

Field of study: Biology
Melt-Spinning of an Intrinsically Flame-Retardant Polyacrylonitrile Copolymer

Poly(acrylonitrile) (PAN) fibers have two essential drawbacks: they are usually processed by solution-spinning, which is inferior to melt spinning in terms of productivity and costs, and they are flammable in air. Here, we report on the synthesis and melt-spinning of an intrinsically flame-retardant PAN-copolymer with phosphorus-containing dimethylphosphonomethyl acrylate (DPA) as primary comonomer. Furthermore, the copolymerization parameters of the aqueous suspension polymerization of acrylonitrile (AN) and DPA were determined applying both the Fineman and Ross and Kelen and Tüdõs methods. For flame retardancy and melt-spinning tests, multiple PAN copolymers with different amounts of DPA and, in some cases, methyl acrylate (MA) have been synthesized. One of the synthesized PAN-copolymers has been melt-spun with propylene carbonate (PC) as plasticizer; the resulting PAN-fibers had a tenacity of 195 ± 40 MPa and a Young’s modulus of 5.2 ± 0.7 GPa. The flame-retardant properties have been determined by Limiting Oxygen Index (LOI) flame tests. The LOI value of the melt-spinnable PAN was 25.1; it therefore meets the flame retardancy criteria for many applications. In short, the reported method shows that the disadvantage of high comonomer content necessary for flame retardation can be turned into an advantage by enabling melt spinning.

Field of study: Materials science
Interacting with the coast: Residents’ knowledge and perceptions about coastal erosion (Mytilene, Lesvos Island, Greece)

Today coastal erosion is usually exacerbated by anthropogenic climate change and results in the loss of income and cultural norms, as well as in the loss or degradation of ecosystem services. Public perceptions and participation have an important role – often a legal one – in coastal management and response to coastal hazards. The objective of this study is to assess residents’ perceptions about coastal erosion and the significance of coastal protection and restoration. This paper presents the results of a study conducted in Mytilene, the main city on the island of Lesvos, Greece. Residents recognize the impact of coastal erosion on their daily lives and recognize the anthropogenic causes of coastal erosion problems including climate change impacts. They admit their share in creating pressures and impacts on the beaches and are aware of the common protection works such as sand nourishment, groins and breakwaters construction. However, while they perceive beaches as the public common, residents indicated unwillingness to pay for coastal zone restoration and protection. Results suggest that respondents prefer volunteering activities and public awareness actions to payment or charges for coastal zone protection.

Field of study: Environmental science
Comparison of human interleukin-1 beta and its 163-171 peptide in bone resorption and the immune response.

Human interleukin-1 beta (IL-1 beta) caused a dose- and time-dependent enhancement of the release of 45Ca from prelabeled mouse calvaria in organ culture. In addition, IL-1 beta dose-dependently stimulated the formation of prostaglandin E2 (PGE2) and 6-keto-PGF1 alpha in the calvarial bones. However, IL-1 beta-induced 45Ca release was only partially inhibited by blocking the PGE2 response with indomethacin, suggesting that enhanced PGE2 formation in response to IL-1 beta is not necessary to obtain a bone resorptive effect, but that prostaglandins potentiate the action of IL-1 beta. The synthetic nonapeptide VQGEESNDK, corresponding to the fragment 163-171 of human IL-1 beta, administered simultaneously with antigen (SRBC) to C3H/HeN male mice, induced a dose-dependent enhancement of specific antibody-producing cells in the spleen (PFC). The degree of PFC stimulation was comparable to that caused by native human IL-1 beta. In mouse bone cultures, neither 45Ca release nor prostanoid formation was stimulated by fragment 163-171. These data indicate that (1) IL-1 beta-induced stimulation of bone resorption is dissociable from IL-1 beta-induced increase of prostanoid biosynthesis and (2) the epitope of the IL-1 beta molecule involved in the immunostimulatory effects may be different from that involved in the stimulatory effects on bone resorption.

Field of study: Medicine
ENHANCING OSMOTIC DEHYDRATION WITH ACOUSTIC CAVITATION

An experimental study was carried out to enhance osmotic dehydration of fruits—apples using acoustic cavitation.The variation in water losses and dry matter gain rates of materials with solute concentration, cavitation intensity, the thickness of materials and treating time segment during osmotic dehydration was discussed,at the same time, the influence of different materials on mass transfer during osmotic dehydration using acoustic cavitation was investigated.The results showed that water losses rates of materials were remarkably increased during osmotic dehydration using acoustic cavitation, but dry matter gain rates increased very little.Meanwhile the physical mechanism of enhanced mass transfer during osmotic dehydration with acoustic cavitation was clarified on the basis of analyzing the experimental results.

Field of study: Chemistry, Environmental science
Kondo scaling in the optical response of YbIn1-xAgxCu4.

Theoretical work on Kondo systems predicts universality in the scaling of observable quantities with the Kondo temperature, T(K). Here we report infrared-frequency optical response measurements of the correlated system YbIn(1-x)AgxCu4. We observe that x-dependent variations in the frequency and strength of a low-energy excitation are related to the x-dependent Kondo temperature. Comparison of the inferred trends with existing theory and a model calculation provides a framework in which to view these experimental results as scaling phenomena arising from local-moment/conduction electron hybridization.

Field of study: Physics
Quantitative analysis in the characterization and optimization of protein crystal growth.

Protein crystal growth often depends on the combination of many different factors. Some affect protein solubility directly; others may act indirectly by causing conformational changes. Systematic characterization of these factors can be important for generating good crystals. It can also provide useful insight into the biochemical behavior of the protein being crystallized. Here we focus on statistical methods to achieve these two objectives. (1) Characterization of a protein system by analyzing patterns of crystal polymorphism under different levels of biochemical parameters, such as ligands and pH. Tests of the reproducibility of crystal growth experiments indicate that quantitative scales of crystal quality can be statistically significant. Analysis of variance for a replicated, full-factorial design in which four factors were tested at two levels has been used to demonstrate highly significant, biochemically relevant, two-factor interactions strongly implicating pH and ligand-dependent conformational changes. (2) Optimization of crystal growth via response-surface methods. 'Minimum predicted variance' designs provide for efficient response-surface experiments aimed at constructing quadratic models in several dimensions. We have used such models to improve crystal size and quality significantly for three forms of Bacillus stearothermophilus tryptophanyl-tRNA synthetase. In one case we can now avoid having to increase the size by repeated seeding, a difficult procedure that also produces unwanted growth of satellite crystals. Graphs of two-dimensional level surfaces reveal a number of ridges, where the same result is obtained for many combinations of the factors usually varied when trying to improve crystals. An important inference is that it may be better to sample simultaneously for the effects of protein concentration and supersaturation. For a system involving only one crystallizing agent, supersaturation can be approximated as the product of protein and precipitant concentrations. Use of this search direction significantly improves the performance of response-surface experiments. Advantages of growing crystals at stationary points of their response surfaces include better crystals and higher reproducibility, since crystal growth at stationary points is insulated from the deleterious effects of experimental fluctuations. This arises because the derivatives of the response are by definition zero with respect to the experimental variables. Quantitative analysis of appropriately designed crystal growth experiments can thus be a powerful way to characterize complex and interacting biochemical dependencies in macromolecular systems and optimize parameters important to the crystallography.

Field of study: Chemistry
Study on Interface Reaction Between 2D C/SiC Composite and Mo

The interfacial chemical reaction of 2D C/SiC-Mo reaction couples was investigated at 1700 ℃ in Ar atmosphere.The composition and microstructure of the interface layer were characterized by XRD,EDS and SEM.The reaction mechanism was discussed.The effects of interfacial residual stress on the thermal mismatch of the reaction couple were also analyzed.The results show that the interfacial reaction products mainly consist of Mo2C,Mo5Si3 and Mo5Si3C,and the diffusion path can be summarized as Mo/Mo2C/Mo5Si3/Mo5Si3C/SiC;the interfacial chemical reaction is controlled by mutual diffusion of the elements,and the diffusion rate constant K0 is 1.05 μm2/s at 1700 ℃;the interface debonds after cooling,because the great residual stress occurs due to the CTE mismatch of the two materials in the reaction couples.

Field of study: Materials science
Two Models for Teaching ESL Developmental Readers in College: A Question of Effectiveness

Finding an effective instruction mode for ESL students in the US educational system has not been an easy task. The country’s secondary and tertiary institutions continue to struggle to meet the needs of their large non-native student populations. The article revisits the debate whether sheltered instruction is an effective model to follow. In our study, a sheltered section of a college-level reading class was more effective in improving students’ reading abilities compared to mainstream sections where the international students were mixed with native speakers.

Field of study: Education
A systematic review of coverage decision-making on health technologies-evidence from the real world.

Quantitative analysis of real-world coverage decision-making offers insights into the revealed preferences of appraisal committees. Aim of this review was to structure empirical evidence of coverage decisions made in practice based on the components 'methods and evidence', 'criteria and standards', 'decision outcome' and 'processes'.



Several electronic databases, key journals and decision committees' websites were searched for publications between 1993 and June 2011. Inclusion criteria were the analysis of past decisions and application of quantitative methods. Each study was categorized by the scope of decision-making and the components covered by the variables used in quantitative analysis.



Thirty-two studies were identified. Many focused on pharmaceuticals, the UK NICE or the Australian PBAC. The components were covered comprehensively, but heterogeneously. Seventy-two variables were identified of which the following were more prevalent: specifications of the decision outcome; the indications considered for appraisal, identification of incremental cost-effectiveness ratios, appropriateness of evaluation methods, type of economic or clinical evidence used for assessment, and the decision date.



Research was dominated by analysis of decision outcomes and appraisal criteria. Although common approaches were identified, the complexity of coverage decision-making - reflected by the heterogeneity of identified variables - will continue to challenge empirical research.

Field of study: Medicine, Political science
Specific catalytic action of large molecules containing imidazole groups

In recent years, studies of the reaction rates of small molecules in the presence of synthetic polymers containing catalytically active functions have contributed significantly to the understanding of the mechanism of enzyme behaviour1. Of particular interest in the field of polymeric catalysis have been the studies of the solvolyses of esters catalyzed by polymers containing pendent imidazole groups because the imidazole moiety has been shown to play a prolific role in enzymatic reactions2—7. In reactions catalyzed by poly-4(5)-vinylimidazole and by poly-5(6)vinylbenzimidazole, three types of cooperative effects have been indicated. (i) Cooperative interaction between two imidazole groups and substrate where neutral imidazole acts as a nucleophile on the substrate and anionic imidazole acts as a general base on the intermediate. This type of bifunctional catalysis was indicated in the poly-4(5)-vinylimidazole catalyzed solvolysis of PNPA (p-nitrophenyl acetate) and in the poly-5(G)vinylbenzimidazole catalyzed solvolyses of PNPA, NABA (4-acetoxy-3nitrobenzoic acid) and NABS (sodium 4-acetoxy-3-nitrobenzenesulphonate), all solvolyses occurring at high pH values3' '. (ii) Cooperative interaction between two neutral, pendent imidazole groups and substrate where at intermediate pH the nucleophilic imidazole reaction is catalyzed by another neutral imidazole function acting as a general base6. (iii) Cooperative interaction between neutral and protonated imidazole groups in the solvolyses of NABA and NABS. The protonated sites on the polymer chain, which do not catalyze the solvolysis of PNPA, apparently serve as binding sites for the negatively charged esters, thereby facilitating a solvolytic attack from a neighbouring imidazole group. Because the solvolytic reactions are dependent on the concentrations of both protonated and neutral sites on the polymer chain, bell-shaped pH-rate profiles were obtained3' 4. A cooperative effect analogous to that described in (iii) (i.e., utilization of electrostatic attraction of substrate to the polymer chain) was observed in the solvolysis of the positively charged ester 3-acetoxy-N-trimethylanilinium iodide (ANTI) catalyzed by a copolymer of 4(5)-vinylimidazole and acrylic acid5. Although this copolymer was a less efficient catalyst than imidazole in solvolyzing PNPA and NABA, it exhibited marked selectivity towards ANTI at high pH values. The higher reactivity of the copolymer was rationalized

Field of study: Chemistry
Disobedient Daughters and the Liberal State: Generational Conflicts Over Marriage Choice in Working Class Families in Nineteenth-Century Oaxaca, Mexico*

Two years in a row (1885 and 1886) Señora Teresa, a native and resident of Oaxaca de Juárez, pleaded with the court to prosecute her daughter's suitors. The first time, after seeing Primitiva chatting with Juan in the street and finding his love letter in her home, she grew apprehensive. She hurried to court when Primitiva disappeared that evening to accuse the young man of seducing and abducting her 13 year old daughter. Police officers apprehended the young couple and the judge listened to their testimonies. Primitiva swore that she was 16 years old and had run away to her aunt's home because she feared her mother's wrath at discovering the love missive. She further stated that she had in fact broken up with Juan some weeks earlier and that they had never engaged in sexual relations. The following year, Primitiva eloped with a different suitor and her mother surfaced in the historical record once more. This time she indicated that she saw her daughter conversing with Francisco in her home's doorway and after he spirited her naïve daughter away, he returned the next day to taunt her husband, boasting that “he took Primitiva because he was a man.” In both cases, Primitiva's mother demanded swift justice. She asked the judge to prosecute her daughter's seducers to the full extent of the law, arguing that Primitiva lacked the maturity to choose her mate wisely. Assenting to the indignant mother's wishes, judges ordered police officers to pick up both young men to face charges of rapto (abduction by seduction) in municipal court. In the first case, the judge dropped the suit for lack of merit. In the latter case, the judge sided with Señora Teresa's minor daughter, in effect emancipating her from parental authority by allowing her to begin family life with her second suitor,

Field of study: History
Temporal differentiation of response duration in children of different ages: developmental changes in relations between verbal and nonverbal behavior.

Children aged 4.5, 7, or 11 years received an experimental session in which a contingency was placed on button-press duration. Each discrete trial was followed by a brief verbal probe asking a question about the contingency requirement. Other groups of children received an identical task followed by a postexperimental interview. Level of adaptation to the duration contingency tended to increase with age in subjects receiving posttrial verbal probes, but not for those who were interviewed. Eleven-year-olds in the verbal probe condition showed a strong correlation between accurate temporal differentiation and number of verbalizations relating to response duration or timing. The younger subjects, with one exception, showed no association between timing-related verbalizations (which were almost totally absent) and response duration differentiation. This developmental difference occurred even though the younger subjects verbalized after almost every trial. The results suggest that although 11-year-old children apparently produce rule-governed behavior under verbal control as adults do, the behavior of younger children may be controlled directly by reinforcement contingencies even when their verbal repertoires are highly developed.

Field of study: Biology, Psychology
An extremal problem for Stokes functions in the plane

c2 = J yj 1 + 8 cos φ άψ = 2 .127. . . o is the smallest constant c such that the estimate sup |v(*) | < c max |u ( í ) | z£D £€3ß holds for every solution ν of the Stokes system in the unit disc D, which is continuous up to the boundary. Moreover, the corresponding "extremal flow" function ν is determined.

Field of study: Philosophy
Towards an Operational Definition of Clinical Competency in Pharmacy

To estimate the inter-rater reliability and accuracy of ratings of competence in student pharmacist/patient clinical interactions as depicted in videotaped simulations and to compare expert panelist and typical preceptor ratings of those interactions.  This study used a multifactorial experimental design to estimate inter-rater reliability and accuracy of preceptors’ assessment of student performance in clinical simulations. The study protocol used nine 5-10 minute video vignettes portraying different levels of competency in student performance in simulated clinical interactions. Intra-Class Correlation (ICC) was used to calculate inter-rater reliability and Fisher exact test was used to compare differences in distribution of scores between expert and nonexpert assessments.  Preceptors (n=42) across 5 states assessed the simulated performances. Intra-Class Correlation estimates were higher for 3 nonrandomized video simulations compared to the 6 randomized simulations. Preceptors more readily identified high and low student performances compared to satisfactory performances. In nearly two-thirds of the rating opportunities, a higher proportion of expert panelists than preceptors rated the student performance correctly (18 of 27 scenarios).  Valid and reliable assessments are critically important because they affect student grades and formative student feedback. Study results indicate the need for pharmacy preceptor training in performance assessment. The process demonstrated in this study can be used to establish minimum preceptor benchmarks for future national training programs.

Field of study: Education, Medicine