nils-herrmann/clean_scirepeval huggingface dataset:
Determination of PCB fluxes from Indiana Harbor and Ship Canal using dual-deployed air and water passive samplers.

We have developed a method for measuring fluxes of PCBs from natural waters using air and water passive samplers deployed simultaneously in the Indiana Harbor and Ship Canal (IHSC). Net volatilization of ƩPCBs was determined for 2017, and ranged from 1.4 to 2.8 μg m-2 d-1, with a median of 2.0 μg m-2 d-1. We confirm earlier findings that the IHSC experiences constant release of gas-phase PCBs. Gas-phase and freely-dissolved water ƩPCB samples median were 4.0 ng m-3 and 14 ng L-1, both exhibiting increasing concentrations over the year of study, and with a strong positive correlation between them (R2 = 0.93 for ƩPCBs). The relative concentrations of individual PCB congeners were very similar between air and water samples, and resemble Aroclor 1248, a mixture previously reported to contaminate the IHSC sediments. Monthly variability of the volatilization fluxes was primarily driven by the freely-dissolved water concentration changes (R2 = 0.87). Although different sampling methods were performed to estimate air-water fluxes between the month of August of 2006 and 2017, ƩPCB net fluxes have decreased by more than 60%, suggesting that either dredging at IHSC from 2012 to 2017 or reduction of upstream sources have decreased the freely-dissolved water concentrations of PCBs, thus reducing the air-water net volatilization in IHSC. Finally, we have shown that this passive sampling approach represents a simple and cost-effective method to assess the air-water exchange of PCBs, increase analytical sensitivity, enable measurements over time, and reduce uncertainties related to unexpected episodic events.

Field of study: Environmental science
Effects of reinforcement context on choice.

Two experiments investigated the effects of successive reinforcement contexts on choice. In the first, concurrent variable-interval schedules of primary reinforcement operated during the initial links of concurrent chains. The rate of this reinforcement arranged by the concurrent schedules was decreased across conditions: When it was higher than the terminal-link rate, preference for the higher frequency initial-link schedule increased relative to baseline. (During baseline, a standard concurrent-schedule procedure was in effect). When the initial-link reinforcement rate was lower than the terminal-link rate, preference converged toward indifference. In the second experiment, a chain schedule was available on a third key while a concurrent schedule was in effect on the side keys. When the terminal link of the chain schedule was produced, the side keys became inoperative. Availability of the chain schedule did not affect choice between the concurrent schedules. These results show that only when successive reinforcement contexts are produced by choice responding do those successive contexts affect choice in concurrent schedules.

Field of study: Biology, Psychology
Measurement of positron range in matter in strong magnetic fields

Positron range is one factor that places a limitation on Positron Emission Tomography (PET) resolution. The distance a positron travels through matter before it annihilates with an electron is a function of its initial energy and the electron density of the medium. A strong magnetic field limits positron range when momentum components are transverse to the field. Measurement of positron range was determined by deconvolving the effects of detector response and radioactivity distribution from the measured annihilation spread function. The annihilation spread function for a 0.5 mm bead of /sup 68/Ga was measured with 0.2 and 1.0 mm wide slit collimators. Based on the annihilation spread function FWHM (Full Width at Half Maximum) for a 1.0 mm wide slit the median positron range in tissue equivalent material is 0.87, 0.50, 0.22 mm at 0, 5.0 and 9.4 T, respectively.

Field of study: Physics
A high-order L2-compact difference method for Caputo-type time-fractional sub-diffusion equations with variable coefficients

A high-order compact finite difference method is proposed for solving a class of time-fractional sub-diffusion equations. The diffusion coefficient of the equation may be spatially variable and the time-fractional derivative is in the Caputo sense with the order α ∈ (0, 1). The Caputo time-fractional derivative is discretized by a (3−α) th-order numerical formula (called the L2 formula here) which is constructed by piecewise quadratic interpolating polynomials but does not require any sub-stepping scheme for the approximation at the first-time level. The variable coefficient spatial differential operator is approximated by a fourth-order compact finite difference operator. By developing a technique of discrete energy analysis, a full theoretical analysis of the stability and convergence of the method is carried out for the general case of variable coefficient and for all α ∈ (0, 1). The optimal error estimate is obtained in the L2 norm and shows that the proposed method has the temporal (3−α) th-order accuracy and the spatial fourth-order accuracy. Further approximations are also considered for enlarging the applicability of the method while preserving its high-order accuracy. Applications are given to three model problems, and numerical results are presented to demonstrate the theoretical analysis results.

Field of study: Mathematics
Efficient Logistic Regression on Large Encrypted Data

Machine learning on encrypted data is a cryptographic method for analyzing private and/or sensitive data while keeping privacy. In the training phase, it takes as input an encrypted training data and outputs an encrypted model without using the decryption key. In the prediction phase, it uses the encrypted model to predict results on new encrypted data. In each phase, no decryption key is needed, and thus the privacy of data is guaranteed while the underlying encryption is secure. It has many applications in various areas such as finance, education, genomics, and medical field that have sensitive private data. While several studies have been reported on the prediction phase, few studies have been conducted on the training phase due to the inefficiency of homomorphic encryption (HE), leaving the machine learning training on encrypted data only as a long-term goal. In this paper, we propose an efficient algorithm for logistic regression on encrypted data, and evaluate our algorithm on real financial data consisting of 422,108 samples over 200 features. Our experiment shows that an encrypted model with a sufficient Kolmogorov Smirnow statistic value can be obtained in ∼17 hours in a single machine. We also evaluate our algorithm on the public MNIST dataset, and it takes ∼2 hours to learn an encrypted model with 96.4% accuracy. Considering the inefficiency of HEs, our result is encouraging and demonstrates the practical feasibility of the logistic regression training on large encrypted data, for the first time to the best of our knowledge.

Field of study: Computer science, Mathematics
Effect of cation doping on ionic conductivity and crystal structure of oxyapatite-type lanthanum silicates

Crystal structures of oxyapatite-type lanthanum silicate (LSO), La9.667Si6O26.5, and Al- and Mg-doped LSOs; La9.667(Si5.8Al0.2)O26.4 and La9.667(Si5.5Mg0.5)O26.0, were refined using synchrotron powder X-ray diffraction (SXRD) data to investigate the origin of enhanced oxide ion (O2 −) conducting behavior with Si-site doping. It was found that temperature factors of oxygen atoms largely increased with slight Al- or Mg-doping into the Si-site of LSO. Especially, that for the 2a-site oxygen located on the c axis (O4) was enhanced by doping. In addition, that for the 12i-site oxygen, O3, the constituent of an SiO4 tetrahedron in the LSO lattice increased with doping anisotropically toward O4. It was suggested that the ionic movement perpendicular to the c axis via SiO4 tetrahedron was activated by cation (M) doping, and that contributed to the ion conduction in addition to the fast ion channel along c axis.

Field of study: Materials science
Ménage à trois of bacterial and viral pulmonary pathogens delivers coup de grace to the lung

Respiratory infections account for more than 4 million deaths worldwide and the inclusion of tuberculosis related deaths pushes this figure close to 8 million . Lower respiratory tract infections are the third leading cause of death worldwide  and are a WHO priority for vaccine development. Research into respiratory immune responses is therefore central to the campaign to decrease the global burden of disease. Public recognition of the threat of respiratory infection has recently increased due to publicity surrounding the emergence of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV), which causes atypical pneumonia with high mortality [3–6].

Field of study: Biology, Medicine
Advanced multigene expression system for Nannochloropsis salina using 2A self-cleaving peptides.

Even though there has been much interest in genetic engineering of microalgae, its progress has been slow due to the difficulty and limitation of available techniques. Currently, genetic modification in most microalgal strains is confined to single gene transformation. Here, a multigene expression system for the oleaginous model strain Nannochloropsis salina was developed with glycine-serine-glycine spacer linked 2A self-cleaving peptides (2A) for the first time. An efficiency test of the four most widely used 2As revealed that two different types of 2As T2A and E2A have the best performance in N. salina with a maximum cleavage rate of nearly 45%. The system was able to express the linked sequence of the selection marker shble and the fluorescence protein sfCherry with intact functions. Because 2A enabled multigene expression in the single cassette form, the use of 2A also reduced the vector size, which along with the stronger promoter resulted in a 9-fold increase in the transformation efficiency. Furthermore, confirmative screening accuracy of more than 90% was observed. Hence, the 2A applied vector system is expected to be beneficial in microalgal research field because it enables multigene expression as well as offering improved transformation and screening efficiency.

Field of study: Biology, Engineering
Determination of Sulfonamides in Water Sample Using Ionic Liquid-based Single Drop Microextraction Coupled with High Performance Liquid Chromatography

A novel method was developed for the determination of seven sulfonamides in water samples using ionic liquid-based single drop microextraction coupled with high performance liquid chromatography.The influence of extraction parameters including extraction solvent,volume of extraction solvent,extraction time,stirring speed,pH value,NaCl concentration of sample solution and extraction temperature were investigated.Using 9 μL 1-butyl-3-methylimidazolium hexafluorophosphate([C4MIM][PF6]) as extraction drop,10.0 mL aqueous sample with 0.33 g/mL NaCl(pH 3) was extracted for 35 min with stirring at 300 r/min at 50 ℃.Under the optimal conditions,good linear relationships were obtained in the sulfonamides concentrations of 0.005-2.000 mg/L with the correlation coefficients of 0.9994-0.9998;the detection limits were 0.001-0.003 mg/L(S/N = 3) ;the enrichment factors of [C4MIM][PF6]for the seven sulfonamides were from 22 to 107;the RSD of matrix spiked samples were 3.1%-5.6%(n = 5).The proposed method was applied to the determination of the seven sulfonamides in tap,river,lake and waste water with recoveries of the seven sulfonamides in the range of 84.3%-106.0%.

Field of study: Chemistry
Effectiveness of regulatory policy in curbing deforestation in a biodiversity hotspot

Recent rates of deforestation on private lands in Australia rival deforestation hotspots around the world, despite conservation policies in place to avert deforestation. This study uses causal impact estimation techniques to determine if a controversial conservation policy - the Vegetation Management Act (VMA) - has successfully reduced deforestation of remnant trees in the Brigalow Belt South, a 21.6 Mha biodiversity hotspot in Queensland. We use covariate matching to determine the regulatory effect of the policy on deforestation rates over time, compared to two counterfactual scenarios representing upper and lower estimates of policy impact. The VMA significantly reduced the rate of remnant deforestation in the highest impact scenario, saving 17, 729 ±1733 ha during 2000-2016. In the lowest scenario, 'panic clearing' before and after enactment of the VMA minimized the amount of remnant forests saved and may have marginally increased deforestation relative to the counterfactual (-404 ±617 ha). At peak effectiveness, the VMA successfully counteracted the amount of remnant deforestation during 2010-2012, but this only represents 4.78% of the 371, 252 ha of remnant forests cleared in the bioregion since enactment in 1999. Thus, while deforestation rates in the region have substantially reduced since the policy was enacted, our results of positive yet limited direct regulatory impact suggests the policy's effectiveness is strongly confounded by other deforestation drivers, like changing socio-economic or climate conditions, as well as new social signals provoked by the policy. The mechanisms through which the policy influences deforestation behavior must be further investigated to ensure real, desirable change is achieved.

Field of study: Environmental science
Phase transitions in nonequilibrium electron-hole systems of Si/SiGe/Si nanoheterostructures

The exciton condensation in a Si1−xGex solid solution layer of Si/Si1−xGex/Si heterostructures with the formation of electron-hole liquid has been investigated by low-temperature photoluminescence spectroscopy. In the temperature range above the critical temperature of the transition from an exciton gas to electron-hole liquid, a Mott transition from an exciton gas to electron-hole plasma has been found and investigated.

Field of study: Physics
Zur Cerenkov-Strahlung von Elektronen dicht über einem Dielektrikum

The Cerenkov radiation of an electron moving parallel to a dielectric boundary is calculated usingToraldo di Francia's expansion of the electron field in a set of evanescent waves. The radiation field is composed of these waves which are refracted at the boundary. In contrast to a previous treatment of this problem byLinhart it is shown that in addition to the TM-waves TE -waves are produced of comparable energy. The angular and frequency distribution is discussed for both types of waves.

Field of study: Physics
What role does measuring medication compliance play in evaluating the efficacy of naltrexone?

Compliance with medication in pharmacotherapy trials of alcoholism has been shown to be equal to, or more, important than in other areas of medicine. Research has suggested that naltrexone's effectiveness can be greatly influenced by the compliance of participants in clinical trials. Presently, we compare 2 compliance measurement methods [urine riboflavin and medication event monitoring system (MEMS)] used simultaneously to evaluate naltrexone's efficacy and the impact of compliance on the size of observable treatment effects.



One hundred and thirty-seven of 160 randomized alcoholic patients completed 12-weeks (84 days) of naltrexone or placebo and cognitive behavioral therapy (CBT) or motivational enhancement therapy (MET). Urine riboflavin was determined during study weeks 2, 6, and 12. The MEMS provided a detailed computerized record of when a participant opened their medication bottle throughout the trial. Baseline predictors of MEMS (80% openings) and urine riboflavin (>or=1,500 ng/mL by fluorimetry) compliance were examined. The effects of the treatments in the compliant participants defined by one, the other, or both methods were compared and contrasted with a previously reported intent-to-treat analysis where compliance was not taken into account.



Age was predictive of compliance. 105 participants were deemed compliant via urine riboflavin criteria, 87 via MEMS, and 77 when both criteria were met, with no significant differences between treatment groups. The most compliant participants showed a significant medication by therapy interaction. Those treated with naltrexone/CBT showed more abstinence days (p<0.03), less heavy drinking days (p<0.03) and less total drinks (p<0.03) than the other groups. The effect size of this interaction increased from about 0.2 in the intent-to-treat analysis, to about 0.4 to 0.5 in the compliant group analyses, with little difference between compliance measurement methods.



Compliance measurement does appear to influence the evaluation of the efficacy of naltrexone within the context of CBT. Treatment effect sizes approximately doubled in the most compliant individuals. Measuring compliance by either of 2 distinct methods provides approximately similar results. As compliance with naltrexone within the context of CBT has such a large impact of treatment outcome, methods of enhancing compliance during treatment should be given the utmost attention.

Field of study: Medicine
Possible Mechanism of Action of the Hypotensive Effect of Peperomia pellucida and Interactions between Human Cytochrome P450 Enzymes

Peperomia pellucida is used as a medicinal plant and as an antihypertensive remedy. We investigated the possible mechanism of this action and its impact on cytochrome P450 (CYP) enzyme activity.  Mean arterial pressure and heart rate were recorded via cannulation of the carotid artery on anaesthetized, normotensive Sprague-Dawley rats following intravenous administration of Peperomia pellucida aqueous (10-30 mg/ kg) plant extract (PPAE). Recordings of the contractile activity of the aortic rings to the extract (1.9-8.6 mg/ml) were done using standard organ bath techniques. Impact on CYP3A4 and CYP2D6 enzyme activities was investigated using human liver and heterologously expressed microsomes.  We observed a dose-dependent reduction in systolic, diastolic, MAP and HR. Pre-treatment with atropine (2 mg/kg) and propranolol (1 mg/kg) but not mepyramine (2 mg/kg) significantly (p<0.05) reduced the hypotensive and negative chronotropic activities caused by the extract, while L-NAME (5 mg/kg) completely abolished it. PPAE significantly (p<0.05) relaxed the phenylephrine (10 -9 -10 -4 M) and KCl- induced contractions and displayed moderate inhibition of CYP3A4 enzyme activity with IC50 values of 0.466 ± 0.126 mg/mL and 0.153 ± 0.054 mg/mL, respectively using heterogenously expressed CYP3A4 and human liver microsomes (HLMs)  Results suggest dose-dependent hypotensive, bradycardic and vasorelaxant effects of PPAE are mediated through Nitric oxide-dependent mechanisms. The impact on CYPs enzyme activities indicate unlikely adverse drug effect when Peperomia pellucida is consumed with other medications reliant on CYP3A4 metabolism.

Field of study: Agricultural and Food sciences
Continuous flocculation-sedimentation for harvesting Nannochloropsis salina biomass.

A continuous flow process is developed for recovery of the biomass of the marine microalga Nannochloropsis salina. Flocculation-sedimentation is used to recover the biomass from an algal suspension with an initial dry biomass concentration of 0.5 g L(-1), as would be typical of a raceway-based biomass production system. More than 85% of the biomass initially in suspension could be settled by gravity in a flocculation-sedimentation device with a total residence time of ∼148 min. Aluminum sulfate was used as an inexpensive, readily available and safe flocculant. The optimal flocculant dosage (as Al2(SO4)3) was 229 mg L(-1). Relative to a highly effective 62-min batch flocculation-sedimentation process for the same alga and flocculant, the continuous flow operation took longer and required nearly double the flocculant dose. The design of the flocculation-sedimentation system is explained.

Field of study: Biology, Engineering
Diazocines on Molecular Platforms

New diazocines as photochromic switches for the surface functionalization via the “platform approach” were synthesized and characterized. Symmetric diazocines as well as asymmetric molecules based on an indane scaffold were obtained and their photochromic properties were investigated. In a final step, the diazocines were mounted on molecular platforms (triazatriangulenium ions).

Field of study: Chemistry
Realization of GaN-based gain-guided blue laser diodes by helium ion implantation

The fabrication process and characteristics of gallium nitride (GaN) based gain-guided blue laser diodes (LDs) are studied, in which an ion implantation process is adopted to confine carrier injection into the active region. The implantation of helium ions with an energy of 85 keV, an angle of 0°, and a dosage of 4.7 × 1014 cm−2 is conducted in the experiment. The specific contact resistivity of p-type ohmic contact of implanted sample is determined to be 2.2 × 10–4 Ω cm2, which is comparable with the un-implanted sample. Then, both ion-implanted gain-guided and ridge waveguide LDs are fabricated at the same time. Similar threshold current density and slope efficiency are obtained, while the operation voltage of ion-implanted gain-guided LDs is 0.2 V lower than the ridge waveguide LDs at 0.56 kA cm−2. The ridge waveguide LDs show multi-mode operation after lasing. However, for ion-implanted gain-guided LDs, the far-field pattern indicates a single lateral mode operation up to twice of the threshold current, and the peak optical output power of blue single mode LDs at 450 nm exceeds 200 mW under pulsed condition.

Field of study: Materials science
On the Conditions for Precautionary Saving

This paper shows that if the signs of the first three derivatives of the utility function are assumed to be invariant in the consumption level, then nonsatiation and risk aversion are sufficient conditions for the presence of precautionary saving. Moreover, a similar set of assumptions ensures that the necessary conditions for decreasing absolute risk aversion and for decreasing absolute prudence are automatically satisfied. Journal of Economic Literature Classification Numbers: D11, E21.

Field of study: Economics
AES Cipher Keys Suitable for Efficient Side-Channel Vulnerability Evaluation

This paper investigates pairs of AES-128 cipher keys and plaintexts which result in being “quiet” in the final round, i.e., whose 128-bit State holds the same bit pattern before and after Round 10. We show that the number of such quiet plaintexts (resulting in Hamming distance 0) for any cipher key is at most 5,914,624, and that there exist exactly 729 cipher keys having such a maximum number. The same holds if “quiet” is replaced by “noisy” (which means to have Hamming distance 128). Because such quiet and noisy plaintexts make extreme actions in the final round of the AES encryption, these AES-128 cipher keys are quite useful for AES hardware designers to efficiently evaluate the vulnerabilities of their products, for instance, the performance of their side-channel attack countermeasures.

Field of study: Computer science, Mathematics