nils-herrmann/clean_scirepeval huggingface dataset:
Multiproxy studies of Early Miocene pedogenic calcretes in the Santa Cruz Formation of southern Patagonia, Argentina indicate the existence of a temperate warm vegetation adapted to a fluctuating water table

The Lower Miocene Santa Cruz Formation in southern Patagonia (Austral Basin, Argentina) contains several horizons of pedogenic calcretes, which record −17.5 myr old vegetation adapted to a shallow and fluctuating water table at paleolatitude of 56°S. To reconstruct the paleoenvironment, paleoclimate and paleoecosystem, we performed a multiproxy study of the calcretes examining abiotic and biotic components. The calcretes exhibit a variety of morphologies (horizontal and vertical rhizoliths, laminar structure, nodules, massive crusts), microfabrics (Beta- predominant over Alpha-microfabrics), and δ18O and δ13C values that fluctuate within each morphotype and throughout the analysed interval. Microfossils and phytoliths in the host material of the calcretes indicate fluctuating terrestrial, freshwater, and marine conditions, and record an ecosystem dominated by herbaceous plants and arboreal elements in association with a typical coastal “Santacrucian” vertebrate fauna. We propose that the calcretes developed in soils in a coastal/fluvial setting during pauses in floodplain aggradation that typically lasted between 8–25 ka and 400 ka years. Variable sedimentation rates in different parts of the coastal/fluvial floodplain, the fine texture of the host sediment, and the influence of a fluctuating water table also influenced the formation of the calcrete. A high water table in low relief areas of the floodplain created the conditions necessary to form a horizontally extended rhizolithic system that, jointly with the biotic proxy, can be correlated with a radicular pattern similar to the arboreal elements from coastal settings. Abiotic and biotic proxies of the studied interval attest to environmental fluctuations recorded at different scales that took place under temperate warm and subhumid climates with a marked rainfall seasonality, with a slight increase in the aridity towards the top of the studied interval. Under these conditions a subtropical fauna and a C3-dominated ecosystem developed coincident with the onset of the Mid-Miocene Climatic Optimum in Patagonia.

Field of study: Environmental science, Geography
Groundwater storage changes in arctic permafrost watersheds from GRACE and in situ measurements

The Arctic permafrost regions make up the largest area component of the cryosphere. Observations from the Gravity Recovery and Climate Experiment (GRACE) mission offer to provide a greater understanding of changes in water mass within permafrost regions. We investigate a GRACE monthly time series, snow water equivalent from the special scanning microwave imager (SSM/I), vegetation water content and soil moisture from the advanced microwave scanning radiometer for the Earth observation system (AMSR-E) and in situ discharge of the Lena, Yenisei, Ob', and Mackenzie watersheds. The GRACE water equivalent mass change responded to mass loading by snow accumulation in winter and mass unloading by runoff in spring–summer. Comparison of secular trends from GRACE to runoff suggests groundwater storage increased in the Lena and Yenisei watersheds, decreased in the Mackenzie watershed, and was unchanged in the Ob' watershed. We hypothesize that the groundwater storage changes are linked to the development of closed- and open-talik in the continuous permafrost zone and the decrease of permafrost lateral extent in the discontinuous permafrost zone of the watersheds.

Field of study: Environmental science
Research on Differential Power Analysis Attack on SMS4 Algorithm

SMS4 algorithm is a block cipher used in WLAN products. In this paper, the differential power analysis attack on SMS4 algorithm is discussed. Based on analyses of the algorithm structure and principles of differential power analysis technologies, an attack method on every byte of round keys is presented. Through this attack, the round keys of the last four rounds of SMS4 can be obtained, and then the 128bit encryption key can be found out. The results of simulation experiments indicate that this attack method is effective and practical on SMS4 round operation. SMS4 algorithm is vulnerable to differential power analysis attacks, and cryptographic devices should be protected to prevent this kind of attacks.

Field of study: Computer science
Interfacial Reaction of Sn and Cu-xZn Substrates After Reflow and Thermal Aging

Zn additions to Cu under bump metallurgy (UBM) in solder joints were the subject of this study. An alternative design was implemented to fabricate pure Sn as the solder and Cu-xZn (x = 15 wt.% and 30 wt.%) as the UBM to form the reaction couple. As the Zn content increased from 15 wt.% to 30 wt.% in the Sn/Cu-Zn system, growth of both Cu3Sn and Cu6Sn5 was suppressed. In addition, no Kirkendall voids were observed at the interface in either Sn/Cu-Zn couple during heat treatment. After 40-day aging, different multilayered phases of [Cu6Sn5/Cu3Sn/Cu(Zn)] and [Cu6Sn5/Cu(Zn,Sn)/CuZn] formed at the interface of [Sn/Cu-15Zn] and [Sn/Cu-30Zn] couples, respectively. The growth mechanism of intermetallic compounds (IMCs) during aging is discussed on the basis of the composition variation in the joint assembly with the aid of electron-microscopic characterization and the Sn-Cu-Zn ternary phase diagram. According to these analyses of interfacial morphology and IMC formation in the Sn/Cu-Zn system, Cu-Zn is a potential UBM for retarding Cu pad consumption in solder joints.

Field of study: Materials science
Conductance fluctuations in graphene devices with superconducting contacts in different charge density regimes

Conductions fluctuations (CF) are studied in single layer graphene devices with superconducting source and drain contacts made from aluminium. The CF are found to be enhanced by superconductivity by a factor of 1.4-2. This (near) doubling of the CF indicates that the phase coherence length is l(phi)greater than or similar to L/2. As compared to previous work, we find a relatively weak dependence of the CF on the gate voltage, and hence on the carrier density. We also demonstrate that whether the CF are larger or smaller at the charge neutrality point (CNP) can be strongly dependent on the series resistance R(C), which needs to be subtracted.

Field of study: Physics
A generalized dimensionless local power-law correlation for refrigerant flow through adiabatic capillary tubes and short tube orifices

This paper presents a new method to obtain generalized dimensionless correlation of refrigerant mass flow rates through adiabatic capillary tubes and short tube orifices. The dimensionless Pi groups were derived from the homogeneous equilibrium model, which is available for different refrigerants entering adiabatic capillary tubes or short tube orifices as the subcooled liquid, two-phase mixture, or supercritical fluid. To mitigate the potential over-fitting risk in neural network, a new “local” power-law correlation reformed from the homogeneous equilibrium model was proposed and compared with the conventional “global” power-law correlation and recently developed neural network model. About 2000 sets of experimental mass flow rate data of R12, R22, R134a, R404A, R407C, R410A, R600a and CO 2 (R744) in the open literature covering capillary and short tube geometries, subcritical and supercritical inlet conditions were collected for the model development. The comparison between the recommended six-coefficient correlation and experimental data reports 0.80% average and 8.98% standard deviations, which is comparable with the previously developed neural network and much better than the “global” power-law correlation.

Field of study: Engineering
Catalase and superoxide dismutase activity in ammonia-oxidising bacteria

A range of ammonia-oxidising bacteria (AOB) was tested for the presence of the oxidative stress enzymes catalase and superoxide dismutase (SOD). All AOB possessed both activities, but overall activity and regulation were in several ways different among the strains. Nitrosomonas europaea contained very high specific activities of catalase compared to the other nitrifiers. Only one catalase isozyme, expressed at a constant specific activity per cell during growth in batch culture, was detectable in N. europaea by native PAGE analysis. In contrast, Nitrosospira multiformis possessed four catalase isozymes whose expression was strongly regulated by growth phase in batch culture. SOD expression patterns in the strains generally followed those of catalase, although changes of the SOD isozyme profiles were not apparent in batch culture. Growth of N. europaea on the surface of membrane filters (microcolony and biofilm formation) resulted in altered proportions of catalase and SOD specific activities, indicating regulation by cell density. This report represents the first description of different isozyme composition and of growth phase-dependent regulation of catalase and SOD enzyme production in AOB.

Field of study: Biology, Environmental science
Big-Bang Nucleosynthesis Reactions Catalyzed by a Long-Lived Negatively Charged Leptonic Particle

An accurate quantum three-body calculation is performed for the new type of big-bang nucleosynthesis (BBN) reactions that are catalyzed by a long-lived negatively-charged, massive leptonic particle (called X^-) such as the supersymmetric (SUSY) particle stau. The reactions studied here includes, i) 4He-transfer reactions such as (4He X)+d --> 6Li+X, ii) radiative capture reactions such as (7Be X)+ p --> (8B X) + gamma, iii) three-body breakup reactions such as (7Li X)+ p --> 4He+4He+X, iv) charge-exchange reactions such as (p X)+4He -->(4He X) +p, and v) neutron induced reactions such as (8Be X)+ n -->9Be+X, where (A X) denotes a Coulombic bound state of a nucleus A and X^-. In recent papers it has been claimed that some of the catalyzed BBN reactions have significantly large cross sections so as to markedly change the abundances of some elements, not only giving a solution to the 6Li-7Li problem (calculated underproduction of 6Li by a factor of 1000 and overproduction of 7Li+7Be by a factor of nearly 3) but also imposing strong restrictions on the lifetime and the primordial abundance of X^-. However, most of the calculations of these reaction cross sections in the literature were performed assuming too naive models or approximations that are unsuitable for the complicated low-energy nuclear reactions. We use a high-accuracy few-body calculational method developed by the authors, and provide precise cross sections and rates of these catalyzed BBN reactions for use in the BBN network calculation.

Field of study: Physics
The Interferon-induced transmembrane protein 3 gene (IFITM3) rs12252 C variant is associated with COVID-19.

The interferon-induced transmembrane proteins play an important antiviral role by preventing viruses from traversing the cellular lipid bilayer. IFITM3 gene variants have been associated with the clinical response to influenza and other viruses. Our aim was to determine whether the IFITM3 rs12252 polymorphism was associated with the risk of developing severe symptoms of COVID-19 in our population.



A total of 288 COVID-19 patients who required hospitalization (81 in the intensive care unit) and 440 age matched controls were genotyped with a Taqman assay. Linear regression models were used to compare allele and genotype frequencies between the groups, correcting for age and sex.



Carriers of the minor allele frequency (rs12252 C) were significantly more frequent in the patients compared to controls after correcting by age and sex (p = 0.01, OR = 2.02, 95%CI = 1.19-3.42). This genotype was non-significantly more common among patients who required ICU.



The IFITM3 rs12252 C allele was a risk factor for COVID-19 hospitalization in our Caucasian population. The extent of the association was lower than the reported among Chinese, a population with a much higher frequency of the risk allele.

Field of study: Medicine
Design Approach on Importing the Weight Information to Improve the Routing Protocol on Ad Hoc Network

Because of the self-characters in Ad Hoc network,its routing protocol is more complex than traditional ones.The paper first analyzes the principles of the AODV and the AODV-BR which is used to improve the former one,and then brings forward the weight information according to the communication ability of the backup nodes by packet transmission rate and delay in ad hoc network to improve the AODV-BR protocol.The simulation results show that the approach is effective.It shortens the delay between the destination node receiving the packets and the source node sending the packets because of the primary route broken and also guarantees the communication quality.

Field of study: Computer science
The Application of Demobilisation, Disarmament and Reintegration (DDR) at the Sub-National Level in the Niger Delta

The oil- and gas-rich Niger Delta region, plagued by violence and dominated by armed militant gangs, typifies the new face of conflict which second generation demobilisation, disarmament and reintegration (DDR) approaches are meant to address at the sub-national level. Fundamental to the emergence of militant gangs and the militarisation of civil society in Nigeria is the federal system of government and its attendant political, social and economic imbalances. This article advances the argument that the implementation of a detailed DDR programme that addresses the governance, ethnic politics, resource control, revenue distribution and national integration issues at the root of the tensions in the troubled oil- and gas-rich region will yield a greater peace dividend for all stakeholders in contrast to the current amnesty programme of the Nigerian government. This programme has been fraught with setbacks and mistrust from its client group (the militants). In so doing, DDR at the sub-national level in the Niger Delta would serve as a tool to achieve peace and long-term stability in the nation not only by removing the tools of violence – weapons and ammunition – from the militants and the civilian population but also by removing the sources of violence as reflected in socio-economic and political inequality within the Nigerian state.

Field of study: History, Sociology
Distributed Detection of Binary Decisions with Collisions in a Large, Random Network

We consider the problem of distributed detection in a large network of sensors. A random number of sensor nodes are randomly deployed. Sensor nodes perform local detection tests and communicate detections over a multiple-access channel to a fusion center. The fusion center can recognize both successful communications and communication collisions in the channel. We derive decision rules for both perfect communications and a delay-constrained communications protocol, and show that each are functions of count statistics only. We derive analytical expressions that characterize the performance of the system in terms of detection performance. We analyze performance with respect to sensor density and with respect to communications delay. Simulation examples validate theoretical predictions with numerical results. We show that the detection performance improves with network density despite increasing communication collisions. In addition, we show that detection performance using the protocol model, with imperfect communications, rapidly converges to the perfect communications case as the number of communication slots increase.

Field of study: Engineering
Soil Sediment Deposits in Subsurface Drains

THE possible mode of sediment entry into drains may be determined by comparing the particle-size dis-tribution curves of the deposits with those of correspond-ing soils. Some deposits will be finer, some similar, and some coarser in texture than the soil. Variations in tex-ture are due to a sorting process effected by the envelope, by reductions in water-flow velocity, by breaks or loose joints in the drain pipe, or by the effluents washing the fine sediments out of the drain. The dispersive effect of a high sodium content can also influence the texture of the deposit.

Field of study: Agricultural and Food sciences
Functional comparison of two full-length genomes of hepatitis B virus strains isolated from two chronic hepatitis B patients.

For studying the characterisitcs of gemomic structures, replication and antigen expression of hepatitis B virus (HBV) strains, the full-length HBV genomes from sera of two chronic hepatitis B patients with high level of serum HBV DNA (10 14 and 10 13 copies/ml respectively) were separately cloned. The full-length genomes of the two HBV strains were sequenced and used to transfect HepG2 cells separately. The HBsAg expressed in the supernatant of transfected HepG2 cells was similar between the two strains, but the level of HBeAg of strain #56 was three times higher than that of strain #2-18 Replication efficiency of HBV strain #56 was significantly higher than that of strain #2-18 detected by Southern blot and hybridization anlaysis of intracelluar viral particles and extracellular replicative intermediates. Both genomes were 3215 nucleotides in length, belonged to genotype B (adw subtype), and were of 98.7% homology. The 42 diverse nucleotides distributed in the C, Pre-S1, Pre-S2, P and X genes and in Sp I, SpII, Xp and ENH I regulatory regions. Since HBV strain #56 had a point mutation at Pre-S2 initial codon (from ATG to GTG), the major protein translated from Pre-S1 contained partial amino acids of Pre-S2, therefore serum sample #56 and the supernatant of transfected HepG2 cells reacted positively with the Pre-S2 antibodies.

Field of study: Biology
Bioaugmentation with Pseudomonas sp. strain MHP41 promotes simazine attenuation and bacterial community changes in agricultural soils.

Bioremediation is an important technology for the removal of persistent organic pollutants from the environment. Bioaugmentation with the encapsulated Pseudomonas sp. strain MHP41 of agricultural soils contaminated with the herbicide simazine was studied. The experiments were performed in microcosm trials using two soils: soil that had never been previously exposed to s-triazines (NS) and soil that had >20 years of s-triazine application (AS). The efficiency of the bioremediation process was assessed by monitoring simazine removal by HPLC. The simazine-degrading microbiota was estimated using an indicator for respiration combined with most-probable-number enumeration. The soil bacterial community structures and the effect of bioaugmentation on these communities were determined using 16S RNA gene clone libraries and FISH analysis. Bioaugmentation with MHP41 cells enhanced simazine degradation and increased the number of simazine-degrading microorganisms in the two soils. In highly contaminated NS soil, bioaugmentation with strain MHP41 was essential for simazine removal. Comparative analysis of 16S rRNA gene clone libraries from NS and AS soils revealed high bacterial diversity. Bioaugmentation with strain MHP41 promoted soil bacterial community shifts. FISH analysis revealed that bioaugmentation increased the relative abundances of two phylogenetic groups (Acidobacteria and Planctomycetes) in both soils. Although members of the Archaea were metabolically active in these soils, their relative abundance was not altered by bioaugmentation.

Field of study: Biology, Environmental science
Influence of a difference between the g factors of levels on the emission characteristics of a two-mode gas laser with an anisotropic resonator in a weak axial magnetic field

A theoretical analysis is made of the influence of a difference between the g factors of the levels of a lasing transition on the emission characteristics of a two-mode gas laser with an anisotropic resonator in a weak axial magnetic field when the Zeeman splitting is considerably smaller than the Doppler line width. The conditions for which the g factors of the levels can be assumed to be equal in the calculations are determined.

Field of study: Engineering, Physics
Analysis of multiple factors affecting physical education learning approaches

The authors studied factors affecting physical education learning approaches.There are many factors that affect physical education learning approaches,including internal factors and external factors.Different internal fac-tors have different effects on physical education learning approaches.The most influential factor among external factors is teacher’s teaching approaches,while the most influential factor among internal factors is student’s learning attitude.Knowing and controlling the level of influence of various factors will play an important guiding role for teachers to give effective learning guidance.

Field of study: Education
Efficient correction for CT image artifacts caused by objects extending outside the scan field of view.

The purpose of this paper is to develop a method of eliminating CT image artifacts generated by objects extending outside the scan field of view, such as obese or inadequately positioned patients. CT projection data are measured only within the scan field of view and thus are abruptly discontinuous at the projection boundaries if the scanned object extends outside the scan field of view. This data discontinuity causes an artifact that consists of a bright peripheral band that obscures objects near the boundary of the scan field of view. An adaptive mathematical extrapolation scheme with low computational expense was applied to reduce the data discontinuity prior to convolution in a filtered backprojection reconstruction. Despite extended projection length, the convolution length was not increased and thus the reconstruction time was not affected. Raw projection data from ten patients whose bodies extended beyond the scan field of view were reconstructed using a conventional method and our extended reconstruction method. Limitations of the algorithm are investigated and extensions for further improvement are discussed. The images reconstructed by conventional filtered backprojection demonstrated peripheral bright-band artifacts near the boundary of the scan field of view. Images reconstructed with our technique were free of such artifacts and clearly showed the anatomy at the periphery of the scan field of view with correct attenuation values. We conclude that bright-band artifacts generated by obese patients whose bodies extend beyond the scan field of view were eliminated with our reconstruction method, which reduces boundary data discontinuity. The algorithm can be generalized to objects with inhomogeneous peripheral density and to true "Region of Interest Reconstruction" from truncated projections.

Field of study: Medicine, Physics
Programmable birefringent lenses with a liquid-crystal display.

We study the properties of a novel birefringent lens constructed by combination of a regular glass lens and a programmable diffractive lens addressed to a liquid-crystal display (LCD). The LCD affects only the vertical polarization state. Consequently the birefringent lens produces two images of an input object with different locations and magnifications for the two orthogonal polarization states. Using a properly oriented analyzer polarizer produces interference fringes. We then show how the imaging system acts as a common-path polarization interferometer for wave-front analysis of objects in the input plane. Finally, we subtract the two images to produce an edge-enhanced version of the input image. All these effects can be controlled because we can program lenses with different focal lengths onto the LCD.

Field of study: Physics