nils-herrmann/clean_scirepeval huggingface dataset:
A Convenient Method for the Lewis Base-catalyzed Synthesis of α,β-Unsaturated Carboxylic Esters Using Trimethylsilylketene Ethyl Trimethylsilyl Acetal and Carbonyl Compounds

A highly useful method for the synthesis of α,β-unsaturated carboxylic esters from various carbonyl compounds that uses trimethylsilylbetene ethyl trimethylsilyl acetal in the presence of a Lewis base catalyst such as acetate salts was established. This procedure gives the corresponding esters in high yields with excellent E stereoselectivity under mild conditions.

Field of study: Chemistry
Malignant Retroperitoneal Hemangiopericytoma: Report of a 73 Years Old Woman and Review of Literature

Seyed Hossein Yahyazadeh , Nasser Malekpour , Mehdi Mousavi , Saadat Molanayi , Bahram Salmanian , Amin Mohamadi 1,2 1Clinical Research Center, Milad Hospital, Tehran, IR Iran 2Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, IR Iran * Seyed Hossein Yahyazadeh, Clinical Research Center, Milad Hospital, Tehran, IR Iran.

Field of study: Medicine
Three-Dimensional Numerical Simulation of Aerodynamic Drag on High-speed Train in Tunnel

The purpose of the paper is to derive variation law of aerodynamic drag introduced by high-speed train passing through a tunnel and to offer guidance for design of high-speed railway longitudinal section and high-speed train head shape. The paper presents a cell-centered finite volume scheme for numerical integration of Navier-Stokes equations for three-dimensional unsteady viscous compressible nonhomentropic flow to simulate the aerodynamic drag introduced by high-speed train passing through a tunnel. The aerodynamic drag curve is analysed and explained in detail in accord with the train positions．

Field of study: Engineering
"The Seriously Injured of Our Civic Life": Imagining Disabled Collectivity in Depression-Era Crip Modernisms

This essay explores how Depression-era cultural production employed a "crip modernism" to render disability as a consciously emerging social, legal, and medical class. Here, I examine modernist engagements with the shifting category of disability, specifically Nathanael West's Miss Lonelyhearts (1933) and the films Freaks (1932) and Beggars in Ermine (1934). I draw these texts together to argue that, in line with a Depression-era interest in the marginalized, they utilize formal experimentation to disrupt notions of disability as an individualized phenomenon belonging merely to the realm of medical expertise. Instead, they register the form of a burgeoning, activist disability collectivity.

Field of study: Art
A study of the evolution of carrier and vacancy depth profiles with annealing temperature of Si-implanted GaAs

The activation of Si implanted into GaAs as a function of temperature and depth has been studied together with the distribution of implantation-induced vacancy defects by automated differential Hall measurement and positron annihilation spectroscopy respectively. A strong influence of implantation damage on the activation of the carriers has been observed, suggesting that two independent activation mechanisms are present dependent on the concentration of defects. An activation energy for the total sheet n-type carrier concentration of is measured while for the carriers in the first the activation energy is . The vacancy defects observed by positron annihilation measurements begin to anneal at temperatures below C; however, residual defects remain even after annealing at C. This study highlights the necessity to measure depth-resolved as opposed to depth-averaged data for the purposes of carrier activation modelling.

Field of study: Materials science
The polymorphisms on exon 11 of luteinizing hormone receptor(LHR) gene and their correlation to production performance in Hu Sheep

The nucleotide sequence and single nucleotide polymorphism on exon 11 of luteinizing hormone receptor(LHR) gene was studied in Hu Sheep by PCR-SSCP.The results showed that only the products amplified by primer P2 and P6 displayed polymorphisms.For primer P2,two genotypes(AA and AB) were detected in Hu Sheep.Sequencing revealed a mutation(G1147A) between genotype of AA and AB.For primer P6,three geno-types(CC,CD and EE) were detected.A mutation of T→A occurred between CC and CD genotypes,and a muta-tion of C→A occurred between CC and EE genotypes.The litter size of AB genotype(2.05±0.76)is higher than that of AA genotype,and the CD genotype's litter size(2.50±0.55) is higher than that of CC and CD genotypes,but no significant difference(P0.05) was found in litter size between AA and AB genotypes or in CC,CD and EE genotypes.

Field of study: Agricultural and Food sciences
Answering Lord Perry's Question: Dissecting Regulatory Overfishing

In 1995, in response to the distressed condition of the British fishing industry, the House of Lords held a series of hearings on "Fish Stock Conservation and Management." Lord Perry of Walton posed the straight-forward question of why regulation was not succeeding: If one takes all the management systems into account - TACs (total allowable catches or annual quotas), number of days at sea and the decommissioning program - none of them has stopped the gross over-fishing that has taken place. There seem to be three factors to account for it: first, the scientific advice that is given; secondly, how far that advice is accepted by politicians who set the TACs and quotas; and, thirdly, whether the fishermen obey the regulations. Which of these are the most at fault at the moment? Lord Perry's question led us to ask to what degree publicly available information in the United States could shed light on the sources of overfishing in individual fisheries - what we will call "regulatory overfishing." First, we set out a typology of the potential sources of regulatory overfishing. Next, we examine two case illustrations of federally managed, overfished fisheries in the United States. Each case generates important insights into the causes of regulatory overfishing and lessons for future management. In the final section of the paper, we make several suggestions aimed at improving fisheries management and the management process.

Field of study: Environmental science
Nb-doped Ga2O3 as charge-trapping layer for nonvolatile memory applications

The charge-trapping properties of Nb-doped Ga2O3 are investigated by using an Al/Al2O3/GaNbO/SiO2/Si structure. Compared with the memory capacitor with pure Ga2O3, the one with lightly Nb-doped Ga2O3 shows better charge-trapping characteristics, including larger memory window (5.5 V at ± 6 V sweeping voltage), higher programming and erasing speeds due to its higher trapping efficiency resulted from increased trap density induced by the Nb doping. The sample with heavily Nb-doped Ga2O3 also shows improvements compared with the one with pure Ga2O3, but not as large as those for the lightly Nb-doped sample due to defects generated by excessive Nb doping. Erase saturation phenomenon is observed in all the samples, and can be suppressed by hole traps created by the Nb doping.

Field of study: Engineering
Transforaminal endoscopic decompression of a postoperative dislocated bone fragment after a 2-level lumbar total disc replacement: case report.

The proposed advantages of total disc replacement (TDR) over fusion in the lumbar spine are the preservation of motion and the avoidance of adjacent-level disease. One of the complications inherent in TDR is the possibility of vertebral body fracture due to trauma or a malpositioned implant. The resulting dilemma is that posterior decompression of the displaced bone fragment could then have a destabilizing effect and possibly require fusion, thus obviating the benefit of an arthroplasty procedure. In this study, the authors describe the technical considerations and feasibility of the treatment of a postoperative L-5 paresis that resulted from a dislocated bone fragment at L4-5 during a 2-level lumbar TDR.

Field of study: Medicine
The dynamical attainability of ESS in evolutionary games

In this paper, the attainability of ESS of the evolutionary game among n players under the frequency-independent selection is studied by means of a mathematical model describing the dynamical development and a concept of stability (strongly determined stability). It is assumed that natural selection and small mutations cause the phenotype to change gradually in the direction of fitness increasing. It is shown that (1) the ESS solution is not always evolutionarily attainable in the evolutionary dynamics, (2) in the game where the interaction between two species is completely competitive, the Nash solution is always attainable, and (3) one of two species may attain the state of minimum fitness as a result of evolution. The attainability of ESS is also examined in two game models on the sex ratio of wasps and aphids in light of our criterion of the attainability of ESS.

Field of study: Biology, Mathematics
Hierarchy in mid-rapidity fragmentation: mass, isospin, velocity correlations

We present new features of the transition from nuclear multifragmentation to neck fragmentation in semi-central heavy-ion collisions at Fermi energies as obtained within a microscopic transport model, Stochastic Mean Field (SMF). We show that along this transition specific hierarchy phenomena of some kinematic observables associated with the intermediate mass fragments develop. Their correlations with the dynamics of isospin degree of freedom, predicted by our calculations, open new possibilities to learn about the density dependence of nuclear symmetry energy below saturation, as well as about the fragmentation mechanisms. Detailed results are presented for mass symmetric Sn + Sn reactions with different isospin content at 50A MeV .

Field of study: Physics
Institutional Reform in East-Central Europe: Hungarian and Polish Contract Law1

East-Central Europe is awash in legal reforms. New constitutions, new property regimes, and new corporate laws clutter the legal landscape. Western commentators have tended to focus on the various means of "privatizing" state assets, while contract law reforms have been largely ignored. This study addresses that void. Hungarians and Poles significantly amended their contract codes in 1990, and now reform commissions in those countries are considering further changes. This article identifies and critiques the changes in contract law currently underway in Hungary and Poland. Sources include English translations of the relevant contract codes, both prior to and following the current reforms.2 In addition, the article draws upon interviews with Hungarian and Polish lawyers, academics, entrepreneurs, and government officials conducted during the author's July 1991 visit to Budapest and Warsaw. The most striking feature of contract law reform is the fact that relatively few contract rules need to be changed. In fact, a comparison of contract rules under central planning with analogous rules in market economies reveals a remarkable degree of convergence. Thus far, Hungarian and Polish reforms have centered on deleting the contract rules that supported central

Field of study: Economics
Synthesis and cytotoxicity of natural (+)-duocarmycin A and its three possible stereoisomers

The title synthesis was accomplished by featuring 1) novel methoxy- carbonylation of the C-4 position of the 5-aminoindoline (dl-13) by way of the isatin (dl-15), 2) the Dieckmann cyclization of diester (dl-19) to the methyl 2- methylindoxyl-2-carboxylates (dl-20 and dl-21), 3) the Wierenga-Kelly-Winstein Ar-3' cyclization as key steps and by employing optical resolutions of various key synthetic intermediates (dl-26, dl-28, dl-34, and dl-36). In vitro cytotoxicity assay of the produced title compounds obviously disclosed that their cytotoxicity is closely related to absolute stereochemistries of cyclopropane moieties. Duocarmycins A (l), C1 (2), C2 (3), B1 (4) and B2 (5) isolated from Streptomyces sp. by a research group at Kyowa Hakko are novel antitumor antibiotics which are effective against various strains of murine cancers (ref. 1 and 2). Almost the same time, workers at Meiji Seika also reported pyrindamycins A and B being identical with 3 and 2, respectively (ref. 1 and 2). Following to 1 - 5, the isolation of duocarmycin SA (6) which is more stable than 1 was recently reported (ref. 1 and 2). The structures of 1 - 6 have been established by X-ray diffraction analysis of 3, chemical derivation of 1 to 2 and 3 or 4 and 5, and consideration of analogy of the structure and biosynthetic process of 6 to those of 1

Field of study: Chemistry
Can community health insurance schemes shield the poor against the downside health effects of economic reforms? The case of rural ethiopia.

Using household level data and double-bounded dichotomous choice contingent valuation method, the article investigates the prospect of community health insurance schemes in mitigating the health shock effects of economic reforms and deregulations on the poor rural households of Ethiopia. The results demonstrate that the introduction of such schemes can help to protect the poor against the adverse impacts of economic reforms on health. It is also demonstrated that enough and sustainable resources can be generated from such schemes without obstructing the current economic reforms and evicting the poor and the socially disadvantaged section of the population out of the health care market.

Field of study: Medicine, Political science
Reaction of 1-substituted tetrahydro-β-carbolines with activated alkynes-a new original approach to the synthesis of tetrahydroazocino[5,4-b]indoles

The transformations of 1-substituted tetrahydro-β-carbolines by the action of activated alkynes were studied. The action of dimethyl acetylenedicarboxylate in methanol gives products of the opening of the tetrahydropyridine fragment, namely, 2-methoxyalkylindoles. The action of ethyl propiolate in ethanol and of tosylacetylene in methanol gives mixtures of azocino[5,4-b]indoles and 2-alkoxyindoles. The action of ethyl propiolate in acetonitrile gives azocinoindoles.

Field of study: Chemistry
Modeling and Mitigating Single-Event Transients in Voltage-Controlled Oscillators

Voltage-controlled oscillators (VCOs) have been shown to dominate the single-event transient (SET) response of mixed-signal circuits such as the phase-locked loop (PLL). An analytical model is presented to determine the VCO design parameters and the associated SET vulnerability. Additionally, radiation-hardened-by-design (RHBD) techniques to mitigate SETs in current-starved VCOs are presented. The proposed mitigation techniques reduce the phase displacement in the output of the VCO following a single-event (SE) by approximately 66%. The availability of the analytical model and RHBD techniques will improve the SE performance of VCO and PLL designs to ensure a specified tolerance to SEs.

Field of study: Physics
Approximating meta-heuristics with homotopic recurrent neural networks

Much combinatorial optimisation problems constitute a non-polynomial (NP) hard optimisation problem, i.e., they can not be solved in polynomial time. One such problem is finding the shortest route between two nodes on a graph. Meta-heuristic algorithms such as $A^{*}$ along with mixed-integer programming (MIP) methods are often employed for these problems. Our work demonstrates that it is possible to approximate solutions generated by a meta-heuristic algorithm using a deep recurrent neural network. We compare different methodologies based on reinforcement learning (RL) and recurrent neural networks (RNN) to gauge their respective quality of approximation. We show the viability of recurrent neural network solutions on a graph that has over 300 nodes and argue that a sequence-to-sequence network rather than other recurrent networks has improved approximation quality. Additionally, we argue that homotopy continuation -- that increases chances of hitting an extremum -- further improves the estimate generated by a vanilla RNN.

Field of study: Computer science
Pressure- and Temperature-Induced Insertion of N2, O2 and CH4 to Ag-Natrolite

This paper aimed to investigate the structural and chemical changes of Ag-natrolite (Ag16Al16Si24O80·16H2O, Ag-NAT) in the presence of different pressure transmitting mediums (PTMs), such as N2, O2 and CH4, up to ~8 GPa and 250 °C using in situ synchrotron X-ray powder diffraction and Rietveld refinement. Pressure-induced insertion occurs in two stages in the case of N2 and O2 runs, as opposed to the CH4 run. First changes of the unit cell volume in N2, O2 and CH4 runs are observed at 0.88(5) GPa, 1.05(5) GPa and 1.84(5) GPa with increase of 5.7(1)%, 5.5(1)% and 5.7(1)%, respectively. Subsequent volume changes of Ag-natrolite in the presence of N2 and O2 appear at 2.15(5) GPa and 5.24(5) GPa with a volume increase of 0.8(1)% and a decrease of 3.0(1)%, respectively. The bulk moduli of the Ag-NAT change from 42(1) to 49(7), from 38(1) to 227(1) and from 49(3) to 79(2) in the case of N2, O2 and CH4 runs, respectively, revealing that the Ag-NAT becomes more incompressible after each insertion of PTM molecules. The shape of the channel window of the Ag-NAT changes from elliptical to more circular after the uptake of N2, O2 and CH4. Overall, the experimental results of Ag-NAT from our previous data and this work establish that the onset pressure exponentially increases with the molecular size. The unit cell volumes of the expanded (or contracted) phases of the Ag-NAT have a linear relationship and limit to maximally expand and contract upon pressure-induced insertion.

Field of study: Materials science
Does the management of surrounding terrestrial habitats increase the tendency of odonates to leave aquatic habitats?

Generally, dragonflies and damselflies (odonates) are considered aquatic invertebrates. However, the ecological requirements of their adults are not different from those of fully, terrestrial insects. Surprisingly, there is a very little information on whether the management and structure of surrounding habitats has any influence on the diversity and seasonal dynamics of odonates. This is important to know because recently, a large proportion of freshwater habitats in Central Europe have becomes surrounded by intensively managed habitats. The aim of this study was to investigate the effects of different types of terrestrial habitats on their long-term utilization by dragonflies and damselflies. I assumed that this pattern varied over time; therefore, I used generalized additive mixed models to analyze the effects of management on seasonal changes in the abundance of individuals in terrestrial environments. From my results, it was evident that the management practices of surrounding terrestrial habitats had a significant impact on the population dynamics of dragonflies. The abundance of dragonfly adults in surrounding terrestrial habitats increased toward the end of the season. However, this was only, when the natal aquatic habitat was not affected by fish farming and was able to supply surrounding terrestrial habitats with offspring. This was evidenced by the fact that, compared to areas with extensive water management, in sites with fish farming, seasonal increases in abundance was negligible. There is no doubt that the structure of surrounding terrestrial habitats has a significant influence on the diversity of terrestrial invertebrates. However, we must not forget that terrestrial habitats, regardless of their management, are not able to replace the poor quality of the aquatic (natal) habitat. Interestingly, the abundance of damselflies decreased toward the end of the season, regardless of the management practices of the surrounding areas. This indicates that their dynamics is more controlled by time stress or other similar mechanisms than that of dragonflies.

Field of study: Environmental science
Hemodynamic instability after carotid artery angioplasty and stent placement: a review of the literature.

In this review of the literature the goal was to determine the frequency and relevance of hemodynamic instability after carotid artery (CA) angioplasty and stent placement. Hemodynamic instability after CA angioplasty and stent placement is a well-recognized phenomenon that occurs in 29 to 51% of patients undergoing the procedure. In some patients this problem is severe enough to warrant treatment with vasopressor agents. Features observed on clinical and angiographic evaluation can help clinicians identify patients who are at risk. Hemodynamic fluctuations encountered as a result of CA angioplasty and stent placement may have adverse clinical consequences, including a higher incidence of myocardial infarction and stroke. Proposed measures to prevent this complication include prophylactic placement of transvenous pacemakers or pretreatment with atropine. Unfortunately, no randomized trials are currently available to assess the efficacy of these approaches. Hemodynamic instability is a common finding after CA angioplasty and stent placement. Clinicians can predict which patients are at risk by considering angiographic and clinical features.

Field of study: Medicine
A Family of Hybrid Analog–Digital Beamforming Methods for Massive MIMO Systems

In massive MIMO systems, hybrid beamforming is an essential technique for exploiting the potential array gain without using a dedicated RF chain for each antenna. In this paper, we consider the data phase in massive MIMO communication, where the transmitter and receiver use fewer RF chains than antennas. We examine several different fully and partially connected schemes and consider the design of hybrid beamformers that minimize the estimation error in the data. For the hybrid precoder, we introduce a framework for approximating the optimal fully digital precoder with a feasible hybrid one. We exploit the fact that the fully digital precoder is unique only up to a unitary matrix and optimize over this matrix and the hybrid precoder alternately. Our alternating minimization of approximation gap (Alt-MaG) framework improves the performance over state-of-the-art methods with no substantial increase in complexity. In addition, we present a special case of Alt-MaG, minimal gap iterative quantization (MaGiQ), that results in low complexity and lower mean squared error (MSE) than other common methods, in the case of very few RF chains. MaGiQ is also shown to coincide with the optimal fully digital solution in some scenarios. For combiner design, we exploit the structure of the MSE objective and develop a greedy ratio trace maximization technique that achieves low MSE under various settings. All of our algorithms can be used with multiple hardware architectures.

Field of study: Engineering
The Iron Content of the Human Brain.—II

1. The content of various forms of iron in different parts of the human brain is recorded, including water-soluble alcohol-ether insoluble iron, alcohol-ether soluble iron, iron combined with protein and iron due to blood.

2. Further results confirmatory to the previous paper (1) are given, showing that there is an excess of “available” or non-haematin iron in those G.P.I. cortexes having a histo-chemical deposit of iron.

3. The results indicate that the excess referred to is in the non-protein iron fraction.

4. The large excess of total iron in the pallidus and corpus striatum is, in the latter case, due largely to protein iron, but in the former case also to the iron in the alcohol-ether extract.

5. The cortex and white matter each contain about 70% protein iron, although the percentage of protein is 47 and 27 respectively (4).

6. The water-soluble alcohol-ether insoluble iron constitutes about 12% of the iron in the white matter, and 25% of the iron in the cortex, corpus striatum and pallidus.

Field of study: Medicine, Psychology