nils-herrmann/clean_scirepeval huggingface dataset:
Determination of Eight Steroid Hormones in Butter Samples by Liquid Chromatography-Tandem Mass Spectrometry

A method was developed for the determination of eight steroid hormones( estrone, α/β-estradiol, estriol, testosterone, epitestosterone, progesterone and testosterone propionate) in butter samples by gel permeation chromatography( GPC) purification-followed by liquid chromatography-tandem mass spectrometry( LC-MS/MS).The samples were first extracted by ethylacetate/cyclohexane( 1∶ 1, V/V) and the extract was later degreased by GPC column. Then, the GPC concentrate was separated using a C 18 column( 100 mm × 2.0 mm i.d., 3.0 μm) with gradient elution of acetonitrile/water. Finally, the steroid hormone components were qualitatively and quantitatively determined by mass spectrometer with electrospray ionization in multi reaction monitoring mode. Using matrix matched external standard method, good linearity in response could be obtained in the concentration range of 1.0- 20.0 μg/kg with correlation co-efficiency larger than 0.999. The detection limits of the method were 0.04- 0.30 μg/kg and the quantification limit was 1.0 μg/kg. At the spike levels of 1.0, 2.0 and 4.0 μg/kg, the recoveries of hormones were within the range of 64.1%- 110%, and the relative standard deviation( RSD) was less than 11%. The results show that the method is accurate and reliable, and meets the requirements for determination of 8 steroid hormones in butter samples.

Field of study: Chemistry
SU-E-T-519: Experimental Evaluation of Deterministic Acuros XB Radiation Transport Algorithm for Heterogeneity Dose Calculation Using the Radiological Physics Center's Lung Phantom.

To evaluate the heterogeneity corrected dose calculations from the Acuros XB (AXB), a novel deterministic dose calculation algorithm based on grid-based Boltzmann transport equation solver (GBBS), for IMRT and VMAT plans.



The Radiological Physics Center's lung phantom was used to create clinically equivalent IMRT and VMAT plans (RapidArc) with the Eclipse planning system 10.0 that were delivered using a Varian 23 iX. Absolute doses and relative dose distributions were measured with thermoluminescent dosimeters (TLDs) and radiochromic film. The measured dose distributions were compared with calculated doses from both AXB (11.0.3) and AAA (10.0.24) dose calculation algorithms. The AXB calculated dose-to-water and dose-to-medium were both compared to measurements. Gamma analysis (±7%/4mm, ±5%/3mm, and ±3%/3mm) was used to quantify correspondence between AXB dose distributions and the film measurements. The computation time between AAA and AXB were also evaluated.



For TLD point doses, both AAA and AXB heterogeneity corrected dose calculations are within 5% inside the PTV for both IMRT and VMAT plans. The agreements observed between the measured and calculated doses for both AXB dose reporting methods are better than those observed with the AAA algorithm. The gamma analysis showed that the differences between AAA, AXB and film measurement met the RPC ±7%/4 mm criteria. The percent of pixels passing rate for both the AXB dose to medium and AXB dose to water are higher than AAA. The computation time between AAA and AXB are comparable for IMRT plans but AXB is significantly faster (4 times) than AAA for VMAT plans.



The AXB implemented in the Eclipse planning system calculates a more accurate heterogeneity corrected dose than the AAA algorithm as compared to measurement in lung and improve the calculation speed for VMAT radiotherapy. Work supported by grants CA10953, CA81647, 2R44CA105806-02, CA016672 (NCI, DHHS).

Field of study: Medicine, Physics
Electrical conduction and oxygen transport in SrFeCo0.5Ox oxide membranes

Electrical and oxygen transport properties of SrFeCo 0.5 O x oxide were investigated at elevated temperatures. The electrica1 conductivity was found in the order of 20–10 S/cm in the temperature range of 1100–600°C. An abnormal region was observed at temperatures around 900°C in which electrical conductivity increased with decreasing temperature, which may be related to the undergoing of phase transformation. An oxygen permeation flux of 159×10 −8 mol/cm 2 ·s was measured in an air/helium gradient at 900°C. The acid treatment on the sintered oxide resulted in a considerable improvement of the oxygen permeability, indicating that the surface oxygen exchange limits the overall oxygen permeation process.

Field of study: Materials science
Neutron scattering patterns show Superconductivity in FeTe0.5Se0.5 likely results from itinerant electron fluctuations

The discovery of the Fe pnictide superconductors generated great interest as the structure consists of planes of a magnetic material quite similar to the cuprate superconductors. Fe(Te0.5Se0.5) is a particularly simple system whose planes are isostructural to the FeAs layers found in the originally discovered superconductors of this type. We report here neutron scattering measurements on this material that provide an understanding of the superconductivity. Since the information about the Fermi surface is available both from photoemission and band structure calculations for FeTe, FeSe and other related materials the neutron spectra can be used to see if the itinerant electron picture is valid. The results are consistent with a picture where there are both electron and hole Fermi surfaces that make exact (pi,pi) transitions possible. This would normally favor either a spin or charge density wave state. However, our measurements show the extent of the region where (pi,pi) transitions take place and demonstrate that there are a much larger number of transitions near pi,pi). The near (pi,pi) transitions are observed both above and below Tc and are expected to be strongly pairing. The superconductivity can be attributed to these excitations while the exactly (pi,pi) transitions produce the narrow resonance excitation that appears below Tc.

Field of study: Physics
Differentially expressed genes associated with apoptosis in human rhabdomyosarcoma cells infected by enterovirus 71

To explore the different apoptotic gene expressions and apoptotic signaling transduction of human rhabdomyosarcoma (RD) cells infected by enterovirus 71 (EV71) in different stage. The survival of EV71-infected RD cells was observed by trypan blue staining.The apoptotic morphology and rates of RD cells were surveyed and detected by Annexin V-FITC/PI staining and flow cytometry,respectively.PCR array was employed to analyze 88 apoptotic gene expressions from EV71-infected RD cells at 8 h and 20 h postinfection (p.i),respectively. After RD cells were infected with EV71 (MOI =5) at 8 h p.i,the viability was significantly decreased.Flow cytometry data demonstrated that the apoptotic rates of EV71-infected RD cells had increased to 18.0％ and 19.1％ at 20 h p.i in early and later stage respectively.RT-PCR array studies revealed significant variations in the expression of apoptotic genes.Among 88 genes,only the expression of IFN-β1 was upregulated 5.22 folds,whereas 47 genes including ACIN1,Akt,Apaf1,caspase and CIDEB were found to be downregulated that were lower than 2 folds at 8 h p.i.However,28 genes including FasL,CD40L,TNF,caspase-10 and caspase-3 were induced more than 2 folds after EV71 infection at 20 h. The downregulation of apoptosis-related genes is associated with viral apoptosis-suppressing effect in RD cells in the early stage of EV71 infection.The death receptor signaling pathways including Fas/FasL and TNF/TNFR are activated to induce cell apoptosis in the late stage of EV71 infection.Moreover,host cell can also inhibit apoptosis by regulating signal pathway of CD40/CD40L,NF-κB/RelA and PI3K/Akt activation. 
 
 
Enterovirus 71;  RT-PCR array;  FasL;  CD40L;  Apoptosis

Field of study: Biology
Ways and problems of linkage between higher education and high-tech industry in India

Since the 1980s,India gradually focuses its attention on the linkage between higher education and high-tech industry.Nowadays,the linkage between them is becoming more and more popular and there are about six ways for these linkages.However,there are some problems underlying these linkages,the main problem is that most linkages are weak indeed.From the perspective of Triple Helix Model,there is much causation for these problems,but the most fundamental one is the governance of Indian universities.

Field of study: Education
Walter Orr Roberts Lecture

This paper, as the written version of the 1995 AMS Walter Orr Roberts Lecture, provides an overview of the current status of the inclusion of land surface processes in climate models. These processes provide fluxes of water and energy to atmospheric models and help determine surface meteorology and climate over the continents. With the increasing complexity and importance of these parameterizations and their detailed treatments of the roles of soils and vegetation have come greater demands for observational programs to evaluate their success and to provide required parameters. Intercomparisons between different land models are also becoming increasingly valuable as a means of identifying their weaknesses and limitations. The paper especially highlights the need for further emphasis on the coupling between land and the atmosphere in models. In particular, it calls for further evolution and improvement of the model treatments of precipitation, cloud effects on surface radiation, and boundary layer processes.

Field of study: Environmental science
Differential expression of tyrosine hydroxylase and membrane dopamine transporter genes in subpopulations of dopaminergic neurons of the rat mesencephalon.

Dopaminergic (DA) cells of the substantia nigra pars compacta (SNC) and the ventral tegmental area (VTA) display differences in their topography, biochemistry and susceptibility to pathological processes. Neuronal dopamine concentration is regulated in large part by tyrosine hydroxylase (TH), the rate-limiting enzyme of dopamine synthesis, and by the dopamine reuptake system. In the present study, TH protein, TH mRNA and dopamine membrane transporter (DAT) mRNA were quantified at cellular level in 4 arbitrary subregions of the rat ventral mesencephalon (lateral, middle, medial SNC and VTA), using in situ hybridization and immunoautoradiography. The distribution of labelling for TH protein and TH mRNA was almost superimposable and close to that of DAT mRNA in mesencephalic neurons. Lower values of cellular expression in TH protein, TH mRNA and DAT mRNA were observed in the lateral part of the SNC compared to the other subregions. TH and DAT expression were correlated in SNC but not in VTA. Indeed DA cells in this region expressed low levels of DAT mRNA in comparison to the middle and medial SNC. These results suggest a heterogeneity of DA metabolism among populations of mesencephalic cells. The relative lower expression of the DAT gene in VTA neurons suggests a less efficient dopamine reuptake capacity, which may partly account for the relative sparing of the mesolimbic system reported in Parkinson's disease and MPTP-treated animals.

Field of study: Biology
A comparative static analysis of urban spatial structure

More than a decade has passed since Alonso published his general theory of the urban land market [l]. In the intervening years, a number of other authors have also developed equilibrium models of urban land rent and density . While the structure of these models has been much discussed, there has been virtually no comparative static analysis done on them. The only exception is Mills’ recent numerical analysis of a city with specified functional forms and parameter values . While Mills’ work is excellent in scope, his reliance on Cobb-Douglas functions would seem to limit the generality of his results. The pm-pose of this paper is to conduct a truly general comparative static analysis on two equilibrium models of urban land rent and density. Unlike other authors, we use a utility function whose only requirement is that both goods be “normal” and have positive income effects. This assumption is sufficient to determine the sign of all effects. In both of our spatial systems, the city is viewed as only a small part of a national economy. The production of goods and services occurs at the city center, but wages, prices, and the costs of commuter travel are all exogeneous. Consumers who work in this center earn the same income and have identical preferences. As with Alonso and others, locational choice essentially represents a tradeoff between land and travel. The first of our cities is “closed” in the sense that population size is exogeneous, while consumer levels of welfare must be determined within the system. This situation is typical of industrially advanced societies, where there is essentially no alternative to living in urban areas. In underdeveloped countries, however, rural life often establishes a base-line level of welfare. Migration to cities occurs until urban advantages are reduced. To mirror this process our second city is “open”-the level of utility is take& to be exogeneous and the population size to be endogeneous. In the “closed” model, then, the four parameters are consumer income,

Field of study: Economics
Economic mitigation challenges: how further delay closes the door for achieving climate targets

While the international community aims to limit global warming to below 2 ° C to prevent dangerous climate change, little progress has been made towards a global climate agreement to implement the emissions reductions required to reach this target. We use an integrated energy–economy–climate modeling system to examine how a further delay of cooperative action and technology availability affect climate mitigation challenges. With comprehensive emissions reductions starting after 2015 and full technology availability we estimate that maximum 21st century warming may still be limited below 2 ° C with a likely probability and at moderate economic impacts. Achievable temperature targets rise by up to ∼0.4 ° C if the implementation of comprehensive climate policies is delayed by another 15 years, chiefly because of transitional economic impacts. If carbon capture and storage (CCS) is unavailable, the lower limit of achievable targets rises by up to ∼0.3 ° C. Our results show that progress in international climate negotiations within this decade is imperative to keep the 2 ° C target within reach.

Field of study: Environmental science
Fischer Indole Synthesis with Selected 2,3-Dideoxy-D-glycero-aldopentose Derivatives. Conversion of D-Xylose to (2S)-3-(Indol-3-yl)propane-1,2-diol

Two independent routes towards (2S)-3-(indol-3-yl)propane-1,2-diol (11) were achieved starting from 3,5-di-O-acetyl-1,2-O-cyclohexylidene-α-D-xylofuranose (1). Ethanethiolysis of 1 afforded acyclic diethyl dithioacetal 2 which was further O-deacetylated to give 3. Selective benzoylation of 3 gave 5-O-benzoyl derivative 4. Treatment of 4 with N-bromosuccinimide in methanol gave methyl furanoside 5 which was further desulfurized over Raney nickel to afford 6. An acid hydrolysis of 6 gave hemiacetal 7 which upon treatment with phenylhydrazine, according to standard Fischer indolization procedure, yielded a mixture of chiral indoles 10. O-Debenzoylation of 10 gave the crystalline diol 11. A more efficient route towards the chiral indole 11 included the initial dethioacetalation of 2 into dimethyl acetal 8 which was further desulfurized over Raney nickel to give the corresponding 2,3-dideoxy derivative 9. Direct Fischer indolization of 9 with phenylhydrazine, followed by O-deacetylation of intermediate 12, afforded the expected indole 11 in good yield.

Field of study: Chemistry
Optimization of CCNs: Exact and heuristic approaches

The present study gives a computerizable exact method to obtain the optimal design of a repairable computer communication system, assuming that a given amount of resources is available for linking the centres. The method is based on the Lawler-Bell algorithm. The objective is to obtain a design that maximizes the global availability of the system. This paper also provides several heuristics for the same problem, when the system under consideration is very large.

Field of study: Engineering
Pleistocene marine submergence of the Connecticut and Hudson valleys

Some postglacial submergence of New England has long been recognized, but the amount has not been determined. Recently it has been shown that the marine plane in the Hudson-Champlain Valley rises from zero at New York Bay to about 750 feet on the Canadian boundary. 2 It is evident that the territory adjacent to the Hudson Valley must have participated in the depression and uplift of the land, and it seems quite certain that the Connecticut Valley, lying parallel with the Hudson-Champlain Valley and only 60 miles distant, should exhibit similar evidences of submergence in oceanic waters. After reviewing the literature on the Connecticut Valley terraces an examination was made of the valley from Long Island Sound northward to Wells River, Vermont. The uplifted plane of the static waters as determined by Professor Emerson for Massachusetts was taken as the provisional datum, and it was found that this plane when . . .

Field of study: Geology
Being in the Game: Effects of Avatar Choice and Point of View on Psychophysiological Responses During Play

The innovative features of multi-player computer games offer compelling opportunities for self-representation during interactions, and the ways in which these avatars are chosen and manipulated may change interactive experiences. This study investigated the effects of avatar choice (choice vs. no choice) and visual point of view (POV; first-person vs. third-person) on the physiological arousal and subjective evaluations of game experiences. A 2 (Avatar Choice, No Avatar Choice) × 2 (first-person POV, third-person POV) × 2 (female players, male players) mixed-design experiment was conducted (N = 22). The results demonstrated that being able to pick the character that will represent the player in the game leads to greater arousal, especially for males. Visual POVs alone did not affect the game player's arousal, but moderated the effect of avatar choice on the game player's heart rates. Avatar choice produced a more pronounced effect in the third-person POV (where the “camera” was located behind the avatar) in which avatar choice was visually more reinforced than in the first-person POV (where the “camera” was the eyes of the avatar). The results also revealed that the gender of the game player was a significant factor in game play experience. The results suggest theoretical implications of video game self-representation and effects on game player's psychophysiological responses.

Field of study: Psychology
Responses to rapid warming at Termination 1a at Gerzensee (Central Europe): Primary succession, albedo, soils, lake development, and ecological interactions

The transition from the Oldest Dryas to the Bolling around 14,685 cal yr BP was a period of extremely rapid climatic warming. From a single core of lake marl taken at Gerzensee (Switzerland) we studied the transition in stable isotopes of oxygen and carbon on bulk sediment and charophyte remains, as well as on monospecific samples of ostracods, after Pisidium a; in addition pollen, chironomids, and Cladocera were analyzed. The δ18O record serves as an estimate of mean air temperature, and by correlation to the one from NGRIP in Greenland it provides a timescale.

The timing of responses: The statistically significant zone boundaries of the biostratigraphies are telescoped at the rapid increase of about 3‰ in δ18O at the onset of Bolling. Biotic responses may have occurred within sampling resolution (8 to 16 years), although younger zone boundaries are less synchronous. Gradual and longer-lasting responses include complex processes such as primary or secular succession. During the late-glacial interstadial of Bolling and Allerod, two stronger and two weaker cool phases were found.

Biological processes involved in the responses occurred on levels of individuals (e.g. pollen productivity), of populations (increases or decreases, immigration, or extinction), and on the ecosystem level (species interactions such as facilitation or competition).

Abiotic and biotic interactions include pedogenesis, nitrogen-fixation, nutrient cycling, catchment hydrology, water chemistry of the lake and albedo (controlled by the transition from tundra to forest).

For the Swiss Plateau this major change in vegetation induced a change in the mammal fauna, which in turn led to changes in the tool-making by Paleolithic people.

Field of study: Environmental science, Geography
Structural insights into conformational switching in the copper metalloregulator CsoR from Streptomyces lividans.

Copper-sensitive operon repressors (CsoRs) act to sense cuprous ions and bind them with a high affinity under copper stress in many bacteria. The binding of copper(I) leads to a conformational change in their homotetramer structure, causing disassembly of the operator DNA-CsoR complex and evoking a transcriptional response. Atomic-level structural insight into the conformational switching mechanism between the apo and metal-bound states is lacking. Here, a new X-ray crystal structure of the CsoR from Streptomyces lividans is reported and compared with a previously reported S. lividans CsoR X-ray structure crystallized under different conditions. Based on evidence from this new X-ray structure, it is revealed that the conformational switching between states centres on a concertina effect at the C-terminal end of each α2 helix in the homotetramer. This drives the Cys104 side chain, a copper(I)-ligating residue, into a position enabling copper(I) coordination and as a result disrupts the α2-helix geometry, leading to a compacting and twisting of the homotetramer structure. Strikingly, the conformational switching induces a redistribution of electrostatic surface potential on the tetrameric DNA-binding face, which in the copper(I)-bound state would no longer favour interaction with the mode of operator DNA binding.

Field of study: Chemistry
The small, the forgotten and the dead: highway impact on vertebrates and its implications for mitigation strategies

Roads affect wildlife in many ways, and probably the most conspicuous of these is by producing roadkills. In Mexico few studies have addressed this issue. In the present study, we look at the richness and abundance of vertebrate roadkills along a 14 km stretch of the Amozoc-Cantona-Perote highway, at the border of the states of Veracruz and Puebla and across two environments: shrubland and grassland. The highway was sampled on 34 days between June 2010 and March 2011. A total of 946 animals were recorded as killed by traffic, and belonged to 58 species. Ten of these are under some protection status by Mexican law. Diversity values for shrubland were D = 0.52 and for grassland D = 1.2, both with Bray–Curtis similarity values of Ibc = 0.12 and complementarity (CAB) was 98.5. The most common roadkilled animals were rodents (genus Peromyscus). We estimate that 11,899 vertebrates are killed annually in this section of the highway. This study highlights the need for designing and applying policies and actions for road construction and maintenance that, together with driver’s education, will allow us to increase landscape connectivity and decrease wildlife roadkills.

Field of study: Environmental science